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BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates to communication systems. More particularly, the present invention relates to a novel and improved method and system for performing hand-off in a wireless communication system.
II. Description of the Related Art
The use of code division multiple access (CDMA) modulation techniques is but one of several techniques for facilitating communications in which a large number of system users are present. Although other techniques, such as time division multiple access (TDMA), frequency division multiple access (FDMA) and AM modulation schemes such as amplitude companded single sideband (ACSSB) are known, CDMA has significant advantages over these other modulation techniques. The use of CDMA techniques in a multiple access communication system is disclosed in U.S. Pat. No. 4,901,307, entitled "SPREAD SPECTRUM MULTIPLE ACCESS COMMUNICATION SYSTEM USING SATELLITE OR TERRESTRIAL REPEATERS" and U.S. Pat. No. 5,103,459, entitled "SYSTEM AND METHOD FOR GENERATING SIGNAL WAVEFORMS IN A CDMA CELLULAR TELEPHONE SYSTEM", both of which are assigned to the assignee of the present invention and are incorporated by reference. The method for providing CDMA mobile communications was standardized by the Telecommunications Industry Association in TIA/EIA/IS-95-A entitled "Mobile Station-Base Station Compatibility Standard for Dual-Mode Wideband Spread Spectrum Cellular System".
In the just mentioned patents, a multiple access technique is disclosed in which a large number of mobile telephone users, each having a transceiver, communicate through satellite repeaters or terrestrial base stations (also known as cell base stations or cell-sites) using code division multiple access (CDMA) spread spectrum communication signals. In using CDMA communications, the frequency spectrum can be reused multiple times thus permitting an increase in system user capacity. The use of CDMA techniques results in much higher spectral efficiency than can be achieved using other multiple access techniques.
A method for simultaneously demodulating data that has traveled along different propagation paths from one base station and for simultaneously demodulating data redundantly provided from more than one base station is disclosed in U.S. Pat. No. 5,109,390 (the '390 patent), entitled "DIVERSITY RECEIVER IN A CDMA CELLULAR COMMUNICATION SYSTEM", assigned to the assignee of the present invention and incorporated by reference herein. In the '390 patent, the separately demodulated signals are combined to provide an estimate of the transmitted data which has higher reliability than the data demodulated by any one path or from any one base station.
Handoffs can generally be divided into two categories--hard handoffs and soft handoffs. In a hard handoff, when a mobile station leaves and origination cell and enters a destination cell, the mobile station breaks its communication link with the origination cell and thereafter establishes a new communication link with the destination cell. In soft handoff, the mobile station completes a communication link with the destination cell prior to breaking its communication link with the origination cell. Thus, in soft handoff, the mobile station is redundantly in communication with both the origination cell and the destination cell for some period of time.
Soft handoffs are far less likely to drop calls than hard handoffs. In addition, when a mobile station travels near a cell boundary, it may make repeated handoff requests in response to small changes in the environment. This problem, referred to as ping-ponging, is also greatly lessened by soft handoff. The process for performing soft handoff is described in detail in U.S. Pat. No. 5,101,501, entitled "METHOD AND SYSTEM FOR PROVIDING A SOFT HANDOFF IN COMMUNICATIONS IN A CDMA CELLULAR TELEPHONE SYSTEM" assigned to the assignee of the present invention and incorporated by reference herein.
An improved soft handoff technique is disclosed in U.S. Pat. No. 5,267,261, entitled "MOBILE STATION ASSISTED SOFT HANDOFF IN A CDMA CELLULAR COMMUNICATIONS SYSTEM", which is assigned to the assignee of the present invention and incorporated by reference herein. In the system of the '261 patent, the soft handoff process is improved by measuring the strength of "pilot" signals transmitted by each base station within the system at the mobile station. These pilot strength measurements are of assistance in the soft handoff process by facilitating identification of viable base station handoff candidates.
The viable base station candidates can be divided into four sets. The first set, referred to as the Active Set, comprises base stations which are currently in communication with the mobile station. The second set, referred to as the Candidate Set, comprises base stations which have been determined to be of sufficient strength to be of use to the mobile station. Base stations are added to the candidate set when their measured pilot energy exceeds a predetermined threshold T ADD . The third set is the set of base stations which are in the vicinity of the mobile station ( and which are not included in the Active Set or the Candidate Set). And the fourth set is the Remaining Set which consists of all other base stations.
In an IS-95-A communication system, the mobile station sends a Pilot Strength Measurement Message when it finds a pilot of sufficient strength that is not associated with any the of the Forward Traffic Channels currently being demodulated or when the strength of a pilot that is associated with one of the Forward Traffic Channels being demodulated drops below a threshold for a predetermined period of time. The mobile station sends a Pilot Strength Measurement Message following the detection of a change in the strength of a pilot under the following three conditions:
1. The strength of a Neighbor Set or Remaining Set pilot is found above the threshold T ADD .
2. The strength of a Candidate Set pilot exceeds the strength of an Active Set pilot by more that a threshold (T COMP ).
3. The strength of a pilot in the Active Set of Candidate Set has fallen below a threshold (T DROP ) for greater than a predetermined time period.
The Pilot Strength Measurement Message identifies the base station and the measured pilot energy in decibels.
A negative aspect of soft handoff is that because it involves redundantly transmitting information it consumes the available communication resource. However, soft handoff can provide great improvement in the quality of communication. Therefore, there is a need felt in the art for a method of minimizing the number of base stations transmitting redundant data to a mobile station user which provides sufficient transmission quality.
SUMMARY OF THE INVENTION
The present invention is a novel and improved method and apparatus for providing soft handoff in a mobile communication system. It should be noted at the outset, that one of the biggest problems with current systems is that the members of active set are determined in accordance with comparisons of measured pilot energy with fixed thresholds. However, the value of providing a redundant communication link to a mobile station depends strongly on the energy of other signals being provided to the mobile station. For example, the value of redundantly transmitting to a mobile station a signal with received energy corresponding to a pilot strength of -15 dB will not be of much value, if the mobile station is already receiving a transmission with signal energy corresponding to a pilot strength of -5 dB. However, redundantly transmitting to a mobile station a signal of received energy corresponding to a pilot strength of -15 dB may be of substantial value, if the mobile station is receiving transmissions with signal energy corresponding to a pilot energy of only -13 dB.
At the mobile station, in determining whether to send a message indicating that a pilot from the candidate set should be moved to a revised active set, the measured pilot energy of each pilot in the candidate set is iteratively compared against a threshold generated in accordance with the a variable COMBINED -- PILOT which is the sum of the energies (i.e. the Ec/Io) of the pilots in the active set. In the preferred embodiment, the optimum value of this threshold is determined by the mobile station itself, without the need to send these thresholds over the air or to verify the mobile station requests at the base station. If the strongest pilot in the candidate set satisfies this threshold condition, it is added to the revised active set, and COMBINED -- PILOT is recomputed to include the newly added pilot signal.
Following the iterative process performed on the members of the candidate set, a second iterative process is performed to determine whether a pilot should be deleted from the revised active set. In this operation, pilots are tested from the weakest member of revised active set to the strongest. A COMBINED -- PILOT energy value is computed that is the sum of the energies of all pilots belonging to the active set. A threshold value is generated in accordance with the COMBINED -- PILOT value as described above and the pilot signal being tested is compared with the threshold. Again, this threshold is determined at the mobile station in order to avoid excessive signaling. If a pilot has been below the threshold value for a predetermined period of time, a message would be sent to the base station indicating that such a pilot should be dropped.
The revised active set list is transmitted to the base station controller through the base stations with which the mobile station is in communication. The base station controller sets up the communication links with the base stations in the mobile generated revised active set list and generates an acknowledgment for the mobile station when the links are set up. The mobile station then conducts communications through the base stations of the revised active set.
In the preferred embodiment, the mobile station monitors the pilot signals and in response to the monitored pilot signals the mobile station compiles members of the candidate set. Moreover, the mobile station determines whether a change to the current active set is desirable in view of the criteria discussed above by measuring the energies of the pilots in the active set and the candidate set, and dynamically adjusting the necessary thresholds based on its own estimation of the communication environment. Upon determining any change in the desired membership of the active set, the mobile station generates a pilot strength measurement message that as described above includes the identities of all pilots in the candidate and active sets, their corresponding measured energy values, and a corresponding indication whether the pilot should remain in the sets or be moved into the neighbor set.
BRIEF DESCRIPTION OF THE DRAWINGS
The features, objects, and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout and wherein:
FIG. 1 is an illustration of a cellular communication network;
FIG. 2 is an illustration of the cellular communication network of FIG. 1 which includes the base station controller;
FIG. 3 is a block diagram of the mobile station of the present invention;
FIG. 4 is a block diagram of the base station of the present invention;
FIG. 5 is a graph of dynamic thresholds of the present invention versus the combined energies of the pilots in the active set, illustrating the linear operations performed on the soft handoff parameters of the present invention;
FIG. 6 is a flow diagram of the method for generating the revised active set in the mobile station; and
FIG. 7 is state diagram illustrating the operation of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates wireless communication network in which the geographical area has been divided up into coverage areas referred to as cells and illustrated by a set of adjacent hexagons. Each cell is served by a corresponding base station 4. Each base station 4 transmits a pilot signal which uniquely identifies that base station. In the exemplary embodiment, the base stations 4 are CDMA base stations. A detail description of soft hand-off in a wireless CDMA communication system is described in detail in the aforementioned U.S. Pat. Nos. 5,101,501 and 5,267,261.
Mobile station 2 is located within the cell served by base station 4A. Since mobile station 2 is located near the cell boundary, it will likely be in a soft hand-off condition, in which it is simultaneously in communication with more than one base station. It may, for example be in communication with base stations 4A and 4B. Thus, base stations 4A and 4B are said to make up the active set. Moreover, it may be that mobile station 2 has determined other base stations in its vicinity to have a measured pilot energy above a predetermined threshold T ADD , but that those base stations are not currently in communication with the mobile station. Those pilots are said to make up the candidate set. The candidate set could be made up of base stations 4C and 4G.
Referring to FIG. 2, a typical communication network is illustrated. Data directed to mobile station 2 is provided from a public switched telephone network or other wireless system (not shown) to base station controller 6. Base station controller 6 provides the data to the base stations in mobile station 2's active list. In the example, base station controller 6 redundantly provides data to and receives data from base stations 4A and 4B
The present invention is equally applicable to conditions where each cell is divided into sectors. Communications to and from each sector can be separately received and demodulated by mobile station 2. For simplicity, the discussion will be described wherein in each base of base station 4 are uniquely located base stations. However, it will be readily seen by one skilled in the art that the present invention is equally applicable to sectored cells, simply by considering the possibility that the base stations can be collocated and transmitting to separate sectors within a cell. The condition where a mobile station is in simultaneous communication with more than one sector of a cell is referred to as softer handoff. The method and apparatus for performing softer hand-off are described in detail in copending U.S. patent application Ser. No. 08/144,903, entitled "METHOD AND APPARATUS FOR PERFORMING HANDOFF BETWEEN SECTORS OF A COMMON BASE STATION", filed Oct. 30, 1993, which is assigned to the assignee of the present invention and incorporated by reference herein.
Within mobile station 2, each copy of the data packet is separately received, demodulated and decoded. The decoded data is then combined to give a estimate of the data of greater reliability than any one of demodulated estimates of the data.
FIG. 3 illustrates mobile station 2 of the present invention. Mobile station 2 continuously or at intermittent intervals measures the strength of pilot signals of base stations 4. Signals received by antenna 50 of mobile station 2 are provided through duplexer 52 to receiver (RCVR) 54 which amplifies, downconverts, and filters the received signal and provides it to pilot demodulator 58 of searcher subsystem 55.
In addition, the received signal is provided to traffic demodulators 64A-64N. Traffic demodulators 64A-64N, or a subset thereof, separately demodulate signals received by mobile station 2. The demodulated signals from traffic demodulators 64A-64N are provided to combiner 66 which combines the demodulated data, which in turn provides an improved estimate of the transmitted data.
Mobile station 2 measures the strength of pilot channels. Control processor 62 provides acquisition parameters to search processor 56. In the exemplary embodiment of a CDMA communication system, control processor 62 provides a PN offset to search processor 56. Search processor 56 generates a PN sequence which is used by pilot demodulator 58 to demodulate the received signal. The demodulated pilot signal is provided to energy accumulator 60 which measures the energy of the demodulated pilot signal, by accumulating the energy for predetermined lengths of time.
The measured pilot energy values are provided to control processor 62. In the exemplary embodiment, control processor 62 compares the energy values to dynamic thresholds as described below.
Mobile station 2 transmits a Pilot Strength Measurement Message which includes all pilots with energy greater than the dynamic threshold and all members of the current active set who's measured pilot energy has not fallen below the dynamic threshold for more than a predetermined time period. In the exemplary embodiment, mobile station 2 generates and transmits a Pilot Strength Measurement Message following the detection of a change in the strength of a pilot under the following three conditions:
1. The strength of a Neighbor Set or Remaining Set pilot is found above the threshold the dynamic threshold.
2. The strength of a Candidate Set pilot exceeds the strength of an Active Set pilot by more that a threshold (T COMP ).
3. The strength of a pilot in the Active Set has fallen below a threshold a dynamic threshold for longer than a predetermined time period.
In the exemplary embodiment, the Pilot Strength Measurement Message identifies the pilot and provides a corresponding measured pilot energy. In the exemplary embodiment, the base stations in the Pilot Strength Measurement Message are identified by their pilot offsets and their corresponding measured pilot energy is provided in units of decibels. The dynamic threshold may be calculated by the mobile station.
Control processor 62 provides the identities of the pilots and their corresponding measured pilot energies to message generator 70. Message generator 70 generates a Pilot Strength Measurement Message containing the information. The Pilot Strength Measurement Message is provided to transmitter (TMTR) 68, which encodes, modulates, upconverts and amplifies the message. The message is then transmitted through duplexer 52 and antenna 50.
Referring to FIG. 4, the Pilot Strength Measurement Message is received by antenna 30 of base station 4 and provided to receiver (RCVR) 28, which amplifies, down converts, demodulates and decodes the received signal and provides the message to base station controller (BSC) interface 26. Base station controller (BSC) interface 26 sends the message to base station controller (BSC) 6. The message is provided to selector 22, which may also receive the message redundantly from other base stations which are in communication with mobile station 2. Selector 22 combines message estimates received from the base stations in communication with mobile station 2 to provide improved packet estimates.
In the preferred embodiment of the present invention, the mobile station 2 monitors the pilot signals and compiles members of each of the above-mentioned sets (active, candidate, and neighbor). Additionally, the mobile station 2 determines whether a change to the current active set is desirable according to the following linear relationships:
Y1=SOFT.sub.-- SLOPE*COMBINED.sub.-- PILOT+ADD.sub.-- INTERCEPT(1)
Y2=SOFT.sub.-- SLOPE*COMBINED.sub.-- PILOT+DROP.sub.-- INTERCEPT(2)
where Y1 is the dynamic threshold above which a candidate set pilot's measured energy must rise before the mobile station will request adding it to the revised active set, and Y2 is the dynamic threshold below which an active set pilot's energy must fall before the mobile station will request moving it from the active set to the candidate set. To provide hysteresis, Y1 is preferably greater than Y2.
From Equations (1) and (2), it can be seen that if a particular active set pilot's measured energy falls below Y2, it is moved to the candidate set. In order for that same pilot to be added back into the revised active set, one of two things must happen; either the value of COMBINED -- PILOT decreases by some amount Δ 1 , or that pilot's own measured energy increases by some amount Δ 2 . Thus, it can be seen that Δ 1 and Δ 2 are the hysteresis values of the COMBINED -- PILOT and individual pilot energy respectively needed to prevent a given pilot from being repeatedly moving in and out of the active set.
Thus, pilots should be added to the revised active set when the COMBINED -- PILOT value is less than or equal to X 1 , and should be dropped from the active set when the COMBINED -- PILOT value is greater than or equal to X 2 . From Equations (1) and (2), it can be shown that:
SOFT.sub.-- SLOPE=Δ.sub.2 /Δ.sub.1 ; (3)
DROP.sub.-- INTERCEPT=T.sub.DROP -X.sub.2 *Δ.sub.2 /Δ.sub.1 ;(4)
and
ADD.sub.-- INTERCEPT=DROP.sub.-- INTERCEPT+Δ.sub.2. (5)
This relationship is further illustrated in FIG. 5. The dynamic thresholds Y1 and Y2 are plotted in dB as a function of combined pilot energy (i.e. E c /I 0 ), also in dB. As can be seen, they are both linear functions with a slope of SOFT -- SLOPE (i.e. Δ 2 /Δ 1 from Equation (3)), and respective y-intercepts of ADD -- INTERCEPT and DROP -- INTERCEPT. Note that the y-intercept values may be negative, and DROP -- INTERCEPT is illustrated in FIG. 5 as a negative value.
An exemplary value for SOFT -- SLOPE is 2. In the preferred embodiment, the mobile station 2 itself may calculate the value of SOFT -- SLOPE by estimating the desired values for Δ 1 and Δ 2 by monitoring the fluctuation of all pilots in both the active and candidate sets as described above with reference to FIG. 3, and then applying the relationship of Equation (3). The mobile station 2, and specifically control processor 62, may estimate the value of Δ 1 by measuring the variations in COMBINED -- PILOT over a predetermined amount of time. For example, Δ 1 in the preferred embodiment is equal to the standard deviation of the COMBINED -- PILOT over a predetermined period to prevent natural variations in COMBINED -- PILOT from causing a handoff request. Additionally, Δ 2 in the preferred embodiment may be set equal to the difference between T ADD and T DROP because the difference between T ADD and T DROP is the same order of hysteresis required for Δ 2 .
As previously discussed, X 1 is shown as the value of COMBINED -- PILOT which is sufficient to cause a pilot to be added to the revised active set (i.e. where Y1 intersects T ADD ). Also, X 2 is shown as the value of COMBINED -- PILOT which is sufficient to cause a pilot to be dropped from the active set (i.e. where Y2 intersects T DROP ). The value of X 2 may be pre-programmed into the mobile station, or provided to the mobile station in a signaling message from the base station. In the preferred embodiment, it is a value high enough to provide a sufficiently robust forward link, while at the same time avoiding unnecessary redundancy. An exemplary value for X 2 is -7.11 dB. In the preferred embodiment, the mobile station itself may determine the value X 1 from its calculation of Δ 1 , Δ 2 and the known values of X 2 and T DROP . Thus, if Δ 1 =1.5, Δ 2 =3, X 2 =-7.11 dB, and T DROP =12.44 dB; then SOFT -- SLOPE=2, ADD -- INTERCEPT=1.22 dB, DROP -- INTERCEPT=-1.78 dB and X 1 =-7.61 dB by Equations (1)-(5) above.
The handoff parameters illustrated above are generated at mobile station 2. These handoff parameters are used as described below to generate a revised active set. By generating the handoff parameters at mobile station 2, rather than at base station 4 or base station controller 6, they may be generated much more quickly and without excessive signaling. Additionally, this avoids having to perform any verification calculation at the base station 4 or base station controller 6. Mobile station 2 measures received pilot energy as described above with respect to FIG. 3. The pilot energy values are provided to control processor 62. In response, control processor 62 generates the handoff parameters. If, based on the handoff parameters generated by the mobile station, a pilot is required to be added to or dropped from the current active set, mobile station 2 transmits a message indicating the members of the revised active set to base station controller 6 through base stations 4. Base station controller 6 sets up communications with mobile station 2. Mobile station 2 reconfigures traffic channel demodulators 64A-64N to demodulate received signals in accordance with the mobile generated revised active set.
In the exemplary embodiment, control processor 62 in mobile station 2 generates the revised active set in accordance with the method shown in FIG. 6. In block 200, pilots with measured energy in excess of threshold T ADD are added to the candidate list, whereas pilots whose measured energy has fallen below T DROP for more that a predetermined time period are removed from the candidate list. In the exemplary embodiment, the time a pilot is below T DROP is tracked by a timer within control processor 62 referred to herein as the T TDROP timer. The T TDROP timer is a timer than keeps track of the time that a pilot has been below the drop threshold. The purpose of the T TDROP timer is to avoid mistakenly dropping a strong pilot which may have a weak measured energy due to short duration change in the propagation environment, such as a fast fade.
In block 202, the pilots in the candidate list are sorted from strongest to weakest. Thus, P C1 is stronger than P C2 , and so on, where P ci is preferably the E C /I 0 for the candidate pilot I as defined in paragraph 6.6.6.2.2 of EIA/TIA IS-95A. In block 204, the variable COMBINED -- PILOT is set equal to the energy of all pilots in the active set. Also, in block 204, loop variable (i) is initialized to the value 1. In block 206, the candidate set member P Ci is tested to determine whether it should be made part of the revised active set. P Ci is compared against a threshold generated in accordance with the current value of COMBINED -- PILOT. In the exemplary embodiment, the threshold (Y1) is generated in accordance with equation (1) above.
If the pilot energy of P Ci exceeds threshold Y1, then the flow moves to block 208. In block 208, a Pilot Strength Measurement Message (PSMM) is sent from mobile station 2 to base station 4 requesting that pilot P ci be added to the active set. The base station 4 then sends a response message directing mobile station 2 to add pilot P Ci to the active set. In block 210, a new value of COMBINED -- PILOT is computed which is equal to the old value of COMBINED -- PILOT plus the energy of pilot P Ci . In block 212, the loop variable (i) is incremented.
In block 213, it is determined whether all pilots in the candidate set have been tested. If all pilots in the candidate set have not been tested, then the flow moves to block 200 and proceeds as described above. If all pilots in the candidate set have been tested or if, back in block 206, the pilot energy of P Ci did not exceed threshold Y1, then the flow moves to block 214. In block 214, the revised active set is sorted from lowest energy to highest energy. Thus, P A1 , has the minimum measured energy in the revised active set, P A2 has the second lowest and so on up to the last member of the revised active set P AN .
In block 218, loop variable i is set to 1. In block 220, COMBINED PILOT for testing P Ai is computed. The value of COMBINED -- PILOT is set equal to the sum of the measured energy of all pilots currently in the active set and having energy greater than the pilot currently being tested. Thus, COMBINED -- PILOT is determined by the equation: ##EQU1## where N is the number of pilots in the active set.
In block 222, the current pilot being tested is compared against a threshold (Y2) determined in accordance with the computed value of COMBINED -- PILOT. In the exemplary embodiment, threshold Y2 is determined in accordance with equation (2) above. If the measured pilot energy P Ai exceeds threshold Y2, then the flow moves to block 224 and the T TDROP drop timers for pilots P Ai to P AN are reset to zero and determination of the revised active set ends in block 234.
If the measured pilot energy P Ai does not exceed threshold Y2, then the flow moves to block 226. In block 226, it is determined whether the T TDROP timer for P Ai has expired. If the T TDROP timer has expired, then, in block 228, the mobile station 2 sends a PSMM to base station 4 requesting that pilot P Ai be removed from the active set and put in the candidate set. Base station 4 sends an affirmative response message, and the flow proceeds to block 230. If in block 226, it is determined that the T TDROP timer for P Ai has not expired, then the flow proceeds directly to block 230. In block 230, the loop variable (i) is incremented. Then, in block 232, it is determined whether all the pilots in the active set P Ai have been tested. If all the pilots in the active set have been tested, then the flow proceeds to block 234 and generation of the revised active set is complete. If all the pilots in the active set have not been tested, then the flow proceeds to block 220 and proceeds as described above.
FIG. 7 shows a state diagram of the operation of the present invention. A given pilot, P Ni , may begin in the neighbor set 700. If the E c /I 0 of the pilot P Ni exceeds the threshold T ADD , then it is added to the Candidate Set 702 by mobile station 2. If a pilot, P ci , is in the candidate set 702, and its E c /I 0 falls below the threshold T DROP and its T TDROP timer expires, then it is moved by mobile station 2 from the candidate set 702 to the neighbor set 700. These two transitions just described correspond to block 200 of FIG. 6--adding and removing pilots from the candidate set.
If the E C /I 0 of a pilot, P ci , in the candidate set exceeds the dynamic threshold Y1 as determined in accordance with Equation (1) above, then a PSMM 706 is sent by mobile station 2 to base station 4 requesting that P ci be added to the active set 708. In response, the base station 4 sends an Extended Handoff Direction Message (EHDM), directing mobile station 2 to add P ci to the active set 708. These two transitions just described correspond to blocks 202-213 of FIG. 6.
If the E C /I 0 of a pilot P ai , in the active set is less than the dynamic threshold Y2, and its T TDROP timer expires, the mobile station 2 sends a PSMM 710 to base station 4 requesting that pilot P ai be dropped from the active set. In response, base station 4 sends an EHDM, directing mobile station 2 to drop P ai from the active set to the candidate set 702. These two transitions just described correspond to blocks 214-228 of FIG. 6.
If the E C /I 0 of a pilot P ai , in the active set is less than the threshold T DROP and its T TDROP timer expires, the mobile station 2 sends a PSMM 704 to base station 4 requesting that pilot P ai be dropped from the active set. In response, base station 4 sends an EHDM, directing mobile station 2 to drop P ai from the active set to the neighbor set 702. There is no corresponding flow diagram herein for these two transitions.
The previous description of the preferred embodiments is provided to enable any person skilled in the art to make or use the present invention. The various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without the use of the inventive faculty. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. | At the mobile station the measured pilot energy of each pilot in the candidate set is iteratively compared against a threshold generated in accordance with the sum of the energies of the pilots in the active set. If the strongest pilot in the candidate set satisfies this threshold condition, it is added to the revised active set. A second iterative process is performed to determine whether a pilot should be deleted from the revised active set. The mobile station determines whether a change to the current active set is desirable by measuring the energies of the pilots in the active set and the candidate set, and dynamically adjusting the necessary thresholds based on its own estimation of the communication environment. | 7 |
This application is a National Stage Application of PCT/IB2009/054636, filed 21 Oct. 2009, which claims benefit of Serial No. TO2008A000770, filed 22 Oct. 2008 in Italy and which applications are incorporated herein by reference. To the extent appropriate, a claim of priority is made to each of the above disclosed applications.
BACKGROUND OF THE INVENTION
The present invention relates to cyanine fluorescent dyes which are functionalized with silanes, their synthesis and their use in the manufacture of fluorescent solid supports, for example fluorescent surfaces or (nano)particles, in the bioconjugation and fluorescent labelling of biomolecules, such as for example nucleosides, nucleotides, nucleic acids (DNA, RNA or PNA), antibodies, proteins and peptides, as well as their use for immobilizing biomolecules on solid supports.
The fluorescent labelling technology is widely used in molecular biology, genomics, proteomics, analytical chemistry, since it is suitable to carry out highly sensitive and specifc tests, efficiently competing with techniques such as radioactive and enzymatic labelling.
DNA probes labelled with fluorescent moieties were shown to be valuable reagents for the separation and analysis of molecules. Specific applications of such fluorescent probes include for example automatic sequencing and DNA mapping; the identification of the concentration of a chemical species capable of binding a second chemical species (for example DNA hybridisation reactions in techniques such as real time PCR, in situ hybridization and molecular recognition with molecular beacons); the localization of biomolecules within cells, tissues or insoluble supports by techniques such as fluorescent staining.
Also fluorescent labelled proteins are very powerful analytical tools which are employed in techniques such as fluorescence microscopy, fluorescent immunoassays, protein chips, cytofluorimetry and laser induced fluorescence capillary electrophoresis.
Among fluorescent dyes, cyanines are widely used as biomolecule labels in several bioanalytical techniques, thanks to their physico-chemical properties such as the high extintion coefficient, the high quantum yield, the independence from pH, the low molecular weight and the possibility to carry out multiple assays with a plurality of fluorophores emitting at different wavelengths. The cyanines are also suitable for use as quenchers if their chemical structure contains suitable groups such as nitro groups.
To be useful as a fluorescent label or quencher in bioconjugations, the cyanine should be provided with a suitable functionalized linker arm having a reactive group.
The research in this filed has therefore focused in the study of innovative functionalized arms, since the chemistry and the behaviour of such linker arms may remarkably affect the fluorescence of the whole molecule as well as other chemical and physical properties such as hydrophobicity/hydrophilicity, aggregation and fluorescence quenching due to intramolecular interactions.
In general, the fluorescent dye molecule may contain a plurality of functionalized linker arms, which are preferably different one from each other in order to avoid the problem of cross-linking between identical molecules, of reticulation, of unwanted reactions or of purification.
There are examples in the literature wherein fluorescent molecules belonging to the class of rhodamines and fluoresceines, as well as luminescent ruthenium complexes, are conjugated to organosilane compounds by coupling reactions that require the use of reactive esters, which are synthesized on the organosilane reagent or on the fluorophore.
However, the use of active esters and generally of active carboxylic groups has remarkable drawbacks, such as the poor stability over time and the difficulty of the synthesis. As a matter of fact, active esters are poorly stable molecules under non anhydrous conditions and are therefore very difficult to store. They are prone to degrade over time by hydrolization and the percentage of active product in a package decreases over time. Moreover, due to their poor stability, it is almost impossible to further store the unused product immediately after opening the package. In addition, the need to work always under perfectly anhydrous conditions makes the synthesis of such compounds particularly difficult and expensive, in that the purification must be performed with the use of anhydrous eluents, especially when the synthesis is conducted on an industrial scale rather than on a lab scale.
International patent application WO2007021946, pages 17-18, discloses the synthesis of cyanines containing a silane functional group by reacting a carboxyl functional group with aminopropyl triethoxysilane in anhydrous pyridine under nitrogen flux for several hours. The final product is treated in anhydrous ether before being purified by chromatography.
The drawbacks of this procedure are the high costs, the complexity and, above all, the need to employ anhydrous solvents. Moreover, the amide bond formed between the cyanine carboxylic acid and the aminopropyl triethoxysilane, or other amine-derivative of silane, is not stable. As a matter of fact, such an amide bond may undergo hydrolization in the aqueous acidic or alkaline environment formed by the conditions required for immobilization of fluorescent derivatives on solid supports, thereby leading again to the formation of the cyanine carboxylic acid and the amino-derivative of silane according to the following scheme:
Similarly, the amide bonds of silane-functionalized cyanines formed by reacting an active ester of a cyanine, such as for example a succinimidyl ester, with an amino-derivative of a silane, may undergo hydrolization.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a cyanine which contains a silane linker arm that does not possess the above-mentioned drawbacks of the prior art.
In particular, an object of the present invention is to provide a cyanine which contains a silane linker arm that does not require an expensive or difficult synthesis, particularly that does not require the use of anhydrous solvents.
Another object of the present invention is to provide a cyanine which contains a silane linker arm that is stable and is not readily hydrolysable.
A further object of the present invention is to provide a cyanine which contains a silane linker arm that is capable of being conjugated with a solid support suitable for performing bioanalytical and diagnostic assays, wherein the conjugation of the cyanine with the support does not lead to a reduction in the fluorophore performance.
These and other objects are achieved by a cyanine modified with a silane linker arm having the general formula (I), including the valence tautomers thereof:
wherein:
R 1 is a linear, saturated or unsaturated alkyl chain, having 1 to 30 carbon atoms, wherein one or more carbon atoms are optionally substituted by a 4-, 5- or 6-membered aromatic or non aromatic cyclic grouping of carbon atoms;
R 8 and R 9 are independently selected from the group consisting of —OCH 3 , —OCH 2 CH 3 , —OCH 2 CH 2 CH 3 , —OCH(CH 3 ) 2 , —OCH 2 CH 2 OCH 3 , —Cl, —Br, —I,
—N(CH 3 ) 2 ,
methyl, ethyl, propyl, isopropyl;
R 10 is selected from the group consisting of —OCH 3 , —OCH 2 CH 3 , —OCH 2 CH 2 CH 3 , —OCH(CH 3 ) 2 , —OCH 2 CH 2 OCH 3 , —Cl, —Br, —I,
—N(CH 3 ) 2 ,
W 1 and W 2 are independently selected from a benzene ring and a naphthalene ring, in which one or more carbon atoms are optionally substituted by one or more heteroatoms selected from oxygen, sulphur, selenium and nitrogen, or one of W 1 and W 2 is absent, or both of W 1 and W 2 are absent;
X 1 and X 2 are independently selected from the group consisting of —O—, —S—, —Se—, —N—, —C(CH 3 ) 2 , —CH═CH—, —NH—, and
wherein j is an integer comprised between 1 and 20 and k is an integer comprised between 1 and 20;
R 2 is selected from the group consisting of hydrogen, —CH 3 , and —R 11 —Y 1 , wherein R 11 is a linear, saturated or unsaturated alkyl chain, having 2 to 30 carbon atoms, wherein one or more carbon atoms are each substituted by a component independently selected from an oxygen atom, a sulphur atom, a —NH— group, a —CONH— group or a 4, 5 or 6-membered aromatic or non aromatic cyclic grouping of carbon atoms, wherein one or more carbon atoms are each optionally substituted by a heteroatom independently selected from oxygen, sulfur, nitrogen and selenium, and wherein Y 1 is selected from the group consisting of hydrogen, methyl, carboxyl, carbonyl, amino, sulphydryl, thiocyanate, isothiocyanate, isocyanate, maleimide, hydroxyl, phosphoramidite, glycidyl, imidazolyl, carbamoyl, anhydride, bromoacetamido, chloroacetamido, iodoacetamido, sulphonyl halide, acyl halide, aryl halide, hydrazide, succinimidyl ester, hydroxysulfosuccinimidyl ester, phthalimidyl ester, naphthalimidyl ester, monochlorotriazine, dichlorotriazine, mono- or di-halide substituted pyridine, mono- or di-halide substituted diazine, aziridine, imidic ester, hydrazine, azidonitrophenyl, azide, 3-(2-pyridyldithio)-propionamide, glyoxal, aldehyde, nitrophenyl, dinitrophenyl, trinitrophenyl, SO 3 H, SO 3 —, —C≡CH and
wherein R 18 , R 19 are independently selected from the group consisting of —OCH 3 , —OCH 2 CH 3 , —OCH 2 CH 2 CH 3 , —OCH(CH 3 ) 2 , —OCH 2 CH 2 OCH 3 , —Cl, —Br, —I,
—N(CH 3 ) 2 ,
methyl, ethyl, propyl, isopropyl; and R 20 is selected from the group consisting of —OCH 3 , —OCH 2 CH 3 , —OCH 2 CH 2 CH 3 , —OCH(CH 3 ) 2 , —OCH 2 CH 2 OCH 3 , —Cl, —Br, —I,
—N(CH 3 ) 2 ,
R 3 , R 4 , R 5 and R 6 are independently selected from the group consisting of hydrogen, —CH 3 , —COOH, —OH, —NO 2 , —OCH 3 , —SO 3 H, —SO 3 − , —Cl, —Br, —I, —O—(CH 2 —CH 2 —O) n —CH 3 wherein n is an integer comprised between 1 and 100, and —R 21 —Y 2 , wherein R 21 is a linear, saturated or unsaturated alkyl chain having 2 to 30 carbon atoms, wherein one or more carbon atoms are each optionally substituted by a component independently selected from an oxygen atom, a sulphur atom, an —NH— group, —CONH group or a 4-, 5- or 6-membered aromatic or non aromatic cyclic grouping of carbon atoms, wherein one or more carbon atoms are each optionally substituted by a heteroatom independently selected from oxygen, sulfur, nitrogen and selenium, and wherein Y 2 is selected from the group consisting of hydrogen, methyl, carboxyl, carbonyl, amino, sulphydryl, thiocyanate, isothiocyanate, isocyanate, maleimide, hydroxyl, phosphoramidite, glycidyl, imidazolyl, carbamoyl, anhydride, bromoacetamido, chloroacetamido, iodoacetamido, sulphonyl halide, acyl halide, aryl halide, hydrazide, succinimidyl ester, hydroxysulfosuccinimidyl ester, phthalimidyl ester, naphthalimidyl ester, monochlorotriazine, dichlorotriazine, mono- or di-halide substituted pyridine, mono- or di-halide substituted diazine, aziridine, imidic ester, hydrazine, azidonitrophenyl, azide, 3-(2-pyridyldithio)-propionamide, glyoxal, aldehyde, nitrophenyl, dinitrophenyl, trinitrophenyl, SO 3 H, SO 3 —, and
wherein R 28 , R 29 are independently selected from the group consisting of —OCH 3 , —OCH 2 CH 3 , —OCH 2 CH 2 CH 3 , —OCH(CH 3 ) 2 , —OCH 2 CH 2 OCH 3 , —Cl, —Br, —I,
—N(CH 3 ) 2 ,
methyl, ethyl, propyl, isopropyl; and R 30 is selected from the group consisting of —OCH 3 , —OCH 2 CH 3 , —OCH 2 CH 2 CH 3 , —OCH(CH 3 ) 2 , —OCH 2 CH 2 OCH 3 —Cl, —Br, —I,
—N(CH 3 ) 2 ,
M is a counterion; and
Q is a polymethinic chain selected from the group consisting of:
wherein R 7 is selected from the group consisting of hydrogen, halogen (for example fluorine, chlorine, bromide or iodine), ═O, phenoxy, thiophenoxy, anilino, cyclohexylamino, pyridine, —R 31 —Y 3 , —O—R 31 —Y 3 , —S—R 31 —Y 3 , —NH—R 31 —Y 3 and aryl optionally substituted with one or more substituents independently selected from the group consisting of —SO 3 H, —SO 3 − , carboxyl (—COOH), amino (—NH 2 ), carbonyl (—CHO), thiocyanate (—SCN), isothiocyanate (—CNS), epoxy and —COZ wherein Z represents a leaving group, wherein R 31 has the same meanings as R 11 and Y 3 has the same meanings as Y 1 .
Suitable leaving groups Z are for example —Cl, —Br, —I, —OH, —OR 15 or —OCOR 15 , wherein R 15 is linear or branched lower C 1 -C 4 alkyl (for example methyl, ethyl, t-butyl or i-propyl), —O—CO—Ar, wherein Ar is optionally substituted aryl, —O—CO-Het, wherein Het is selected from succinimide, sulfosuccinimide, phthalimide and naphthalimide, —NR 22 R 33 , wherein R 22 and R 33 are each independently linear or branched C 1 -C 10 alkyl.
The expression “optionally substituted carbon atom” means that such a carbon atom in the linear alkyl chain or in the cyclic grouping of atoms may be replaced by one of the mentioned components or heteroatoms.
The cyanine of the present invention, which is modified with a silane linker arm, and which may also be designated as “silane-containing cyanine”, allows to manufacture fluorescent solid supports such as fluorescent surfaces or nanoparticles in which the fluorescent dye is homogeneously dispersed, which leads to a remarkable signal enhancement and to the increase of the fluorophore performance, in terms of both photoluminescence yield and photo stability.
With the silane-containing cyanine of the present invention it is possible to manufacture nanometric devices that are capable of remarkably enhancing the signal. Furthermore, the silane-containing cyanine of the present invention allows to obtain fluorescent nanoparticies that are capable of emitting at different wavelengths and are capable of being conjugated with biomolecules, such as for example nucleosides, nucleotides, nucleic acids, antibodies and proteins, useful for performing bioanalytical and diagnostic assays and for molecular imaging.
Preferred examples of silane-containing cyanines that fall within the scope of the present invention are as follows:
The silane-containing cyanines of formula (I) are synthesized according to a reaction scheme comprising the following steps:
1. synthesis of a quaternary ammonium salt functionalized with a silane (A),
2. synthesis of a second quaternary ammonium salt (B),
3. synthesis of the hemicyanine, and
4. synthesis of the cyanine.
Step 1 is carried out by reacting, in a suitable solvent such as sulfolane, acetonitrile or N,N-dimethylformamide, a nitrogen containing heterocyclic system (A 1 ) with a terminal silane-containing molecule (A 2 ) to provide the silane-functionalized quaternary ammonium salt
(A):
wherein X 2 , R 1 , R 4 , R 6 and W 2 , R 8 , R 9 , R 10 are as defined in formula (I); R 16 is selected from the group consisting of iodine, chlorine, bromine, OH, sulphate and tosylate.
Step 2 consists of the synthesis of a second quaternary ammonium salt (B) starting from a second nitrogen-containing heterocyclic system (B 1 ) and an alkylating molecule R 2 —R 16 (B 2 ) according to the following scheme:
wherein X 1 , R 2 , R 3 , R 5 and W 1 are as defined in formula (I) and R 16 is selected from the group consisting of iodine, chlorine, bromine, OH, sulphate and tosylate.
Step 3 can be carried out either on the silane-containing quaternary ammonium salt (A) synthesised in step 1 or on the quaternary ammonium salt (B) synthesised in step 2.
This step consists in the reaction between A or B and a compound capable of reacting with the heterocyclic quaternary ammonium salt thereby providing the polymethinic chain:
Non limiting examples of such compounds are triethylortoformiate, N,N-diphenylformamide, malonaldehyde dianylide, pyridylmalonaldehyde, trimethoxypropene, pentamidinium chloride, chloromalonaldehyde dianylide and squaric acid. Step 3 provides an intermediate designated as hemicyanine. By way of example, the structural formula of the hemicyanine obtained by reacting the intermediate A with malonaldehyde dianylide is provided herein below:
Step 4 is carried out by reacting the hemicyanine obtained in step 3 with the heterocyclic quaternary ammonium salt A or B not used in the previous step. A silane-containing cyanine of formula (I) is obtained.
In all the steps illustrated above, the reaction conditions depend on the reagents employed in the various passages and on the desired final product.
Due to the presence of at least one linker arm functionalized with a silane group, the silane-containing cyanines of formula (I) are capable of reacting with hydroxyl or silanol (Si—OH) groups exposed on a solid support such as for example a surface or a particle of any size and geometrical shape. Such properties render the silane-containing cyanines of formula (I) suitable for use in preparing fluorescent solid supports, such as for example fluorescent nanoparticles, as well as for the functionalization of surfaces with biomolecules of analytical and diagnostic interest, for the manufacture of devices suitable for optical visualization of events and reactions which take place inside the cells, for the visualization of receptors on cells or tissues, for the manufacture of tools for in vivo molecular imaging.
Thus, a silane-containing cyanine of formula (I) conjugated, through a silane linker arm, to a solid support containing exposed hydroxyls, also falls within the scope of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the silane-containing cyanine conjugated with a solid support is represented by the following general formula (II):
wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , X 1 , X 2 , W 1 , W 2 , M and Q are as defined in connection with formula (I).
Another preferred embodiment of the silane-containing cyanine conjugated with a solid support is represented by the following general formula (III):
wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , X 1 , X 2 , W 1 , W 2 , M and Q are as defined in connection with formula (I).
When the cyanine contains more than one silane linker arm (for example —Si(R 18 )(R 19 )(R 20 ) and/or —Si(R 28 )(R 29 )(R 30 ) in addition to —Si(R 8 )(R 9 )(R 10 )), it should be understood that the conjugation with the solid support can take place through any one of the silane linker arms or even through a plurality of silane linker arms.
The solid support containing exposed hydroxyls can be for example an amorphous silica (e.g. aerosil), a zeolite (e.g. ZSM-5, faujasite, zeolite-A, mordenite), a mesoporous silica (e.g. MCM-41, MCM-48, SBA-15, SBA-16), a metal, a metal chloride (e.g. CuCl 2 , Fe(Cl) 3 ), a metal sulphate (e.g. NaSO 4 , Ce(SO 4 ) 2 ), a metal oxide (e.g. magnetite, Fe 3 O 4 , Fe 2 O 3 , MgO, TiO 2 , Al 2 O 3 , ZrO 2 , Y 2 O 3 , SnO 2 ), a rare earth metal oxide (e.g. CeO 2 , Eu 2 O 3 , Gd 2 O 3 ), a transition metal oxide, a mixed oxide of two or more metals, a metal alloy, an inorganic semiconductor (e.g. CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, GaAs, InGaAs, InP, InAs, Ge, Si), diamond.
The support can be a flat surface or a particle of any geometrical shape and of any size, for example, a spherical or substantially spherical particle. The particle is preferably a nanoparticle, having at least one size lower than 500 nm. If the particle is spherical, the size lower than 500 nm is the particle diameter.
The silane-containing cyanine can be immobilized on an outer surface of the particle or it can be immobilized within the particle during the synthesis of the particle by mixing the silane-containing cyanine according to the present invention with the reagents that, by polymerization in a microemulsion, form a solid particle structure, for example according to the method disclosed in Wang et al. (Analytical Chemistry, 2006 (3), 646-654).
The conjugation reaction of the silane-containing cyanine on the solid support that contains exposed hydroxyls is carried out in a suitable anhydrous organic solvent, for example anhydrous N,N-dimethylformamide (DMF) or anhydrous toluene. The reaction is preferably carried out under reflux and in the dark for 12 to 18 hours. When the reaction time has elapsed, the functionalized support is removed from the reaction solvent, washed and subjected to thermal treatment, for example in an oven at a temperature of between 90 and 150° C. for 15-18 hours. Such a thermal treatment is essential for the completion of the condensation of the silane linker of the cyanine with the hydroxyls of the support.
A preferred embodiment of the invention is a silane-containing cyanine of formula (I) wherein at least one of R 2 , R 3 , R 4 , R 5 and R 6 contains a reactive functional group different from a silane group. Such a second reactive functional group is preferably selected from carboxyl, amino, sulphydryl, tiocyanate maleimide, succinimidyl ester and hydrazine.
In this instance, the cyanine is a bifunctional or multifunctional molecule (depending on the total number of reactive functional groups it contains), which is advantageously capable of being immobilized onto solid supports having exposed hydroxyls groups and is simultaneously capable of being conjugated with a biomolecule such as a protein, a peptide, a nucleoside, a nucleotide, an oligonucleotide, a nucleic acid, a vitamin or an hormone.
A bifunctional silane-containing cyanine conjugated with both a solid support and a biomolecule is represented by the following general formula (IV):
wherein R 1 , R 3 , R 4 , R 5 , R 6 , R 7 , R 11 , X 1 , X 2 , W 1 , W 2 , M and Q are as defined in connection with formula (I).
Another embodiment of the bifunctional silane-containing cyanine conjugated with both a solid support and a biomolecule is represented by the following general formula (V):
wherein R 1 , R 3 , R 4 , R 5 , R 6 , R 7 , R 11 , X 1 , X 2 , W 1 , W 2 , M and Q are as defined in connection with formula (I).
The bifunctional silane-containing cyanines of the invention are useful for preparing fluorescent oligonucleotides or proteins immobilized on the surface of nanoparticles, useful in molecular recognition assays with signal enhancement.
The following examples are provided by way of illustration only and should not be intended to limit the scope of the invention as defined in the appended claims.
EXAMPLE 1
Synthesis of 1-propyltrimethoxysilane-1′-propyltrimethoxysilane-3,3,3,3′-tetramethyl-5,5′-disulfonate-indomonocarbocyanine potassium salt (IRIS3 sulfo silane) (Compound 1)
a) Synthesis of N-propyltrimethoxysilane-2,3,3-trimethylindoleninium-5-sulfonate
2,3,3-trimethyl-3H-indolenine-5-sulfonate potassium salt (5 g; 0.02 mol) was dissolved in sulfolane and placed in a round bottom flask, heated in a oil bath at 100° C., equipped with a condenser. When the 2,3,3-trimethyl-3H-indolenine-5-sulfonate potassium salt was completely dissolved, 11.6 g (0.04 mol) of iodopropyltrimethoxysilane were added.
The reaction mixture was stirred at reflux (100° C.) for 20 hours. The reaction mixture was then cooled at r.t. and added dropwise to 800 ml of diethyl ether. The suspension obtained was filtered and the product recovered on a filter, washed with diethyl ether and dried in vacuum in a desiccator.
b) Synthesis of IRIS3 sulfo silane
2 g (4.5 mmol) of N-propyltrimethoxysilane-trimethylindoleninium-5-sulfonate, 0.98 g (10 mol) of potassium acetate, 0.882 g (4.5 mol) of N,N-diphenylphormamidine and 60 ml of acetic anhydride were placed in a 250 ml round bottom flask. The round bottom flask, equipped with a condenser, was placed into an oil bath preheated at 80° C. The reaction mixture was stirred at 80° C. for 15 hours, then the temperature was lowered at r.t. and the mixture was added dropwise to 600 ml of diethyl ether. The product was recovered by filtration on a sintered glass funnel, washed with diethyl ether and dried in vacuum in a desiccator. The product was purified by flash chromatography on reverse phase silica (RP-C 18 ), with gradient elution (dichloromethane/methanol from 98/2 to 40/60). Yield: 60%. The product has an absorption maximum centred at 556 nm (in water) and an emission maximum at 572 nm (in water).
FIG. 1 shows the absorption (-) and emission (- -) spectra of sulfo silane IRIS3 (Compound 1).
EXAMPLE 2
Synthesis of 1-(5-carboxypentyl)-1′-propyltrimethoxysilane-3,3,3′,3′-tetramethyl-5,5′-disulfonate indodicarbocyanine potassium salt (Compound 2)
a) Synthesis of N-propyltrimethoxysilane-2,3,3-trimethylindoleninium-5-sulfonate
5 g (0.02 mol) of 2,3,3-trimethyl-3H-indolenine-5-sulfonate potassium salt were dissolved in the lower possible amount of sulfolane and placed in a round bottom flask in a oil bath, pre-heated at 130° C., equipped with a condenser. When the 2,3,3-trimethyl-3H-indolenine-5-sulfonate potassium salt was completely dissolved, 11.6 g (0.04 mol) of iodopropyl-trimethoxysilane were added.
The reaction mixture was stirred at reflux (100° C.) for 20 hours. The reaction mixture was then cooled at r.t. and added dropwise to 800 ml of diethyl ether. The suspension obtained was filtered and the product recovered on a sinterised glass filter, washed with diethyl ether and dried in vacuum in a desiccator.
b) Synthesis of N-(5-carboxypentyl)-2,3,3-trimethylindoleninium-5-sulfonate
5 g (0.02 mol) of 2,3,3-trimethyl-3H-indolenine-5-sulfonate potassium salt were dissolved in sulfolane and placed in a round bottom flask in a oil bath, pre-heated at 130° C., equipped with a condenser. When the 2,3,3-trimethyl-3H-indolenine-5-sulfonate potassium salt was completely dissolved, 9.6 g (0.04 mol) of iodohexanoic acid were added.
The reaction mixture was stirred at 130° C. for 18 hours. The reaction mixture was then cooled at r.t. and added dropwise to 800 ml of diethyl ether. The suspension obtained was filtered and the product recovered on a sintered glass filter, washed with diethyl ether and dried in vacuum in a desiccator.
c) Synthesis of 2-{(E)-2[acetyl(phenyl)amino]vinyl}-1-(5-carboxypentyl)-3,3-dimethyl-3H-indolium-5-sulfonate potassium salt (hemicyanine)
3.3 g (8.43 mmol) of N-(5-carboxypentyl)-2,3,3-trimethylindoleninium-5-sulfonate, 16.98 mmol of malonaldheyde dianylide hydrochloride, 6.0 ml of acetyl chloride and 60.0 ml of acetic anhydride were placed into a 250 ml round bottom flask. The mixture was heated and stirred at 120° C. for 90 min. The solution was cooled at r.t. and added dropwise to 500 ml of diethyl ether. The product was recovered on a sinterised glass filter, washed with di-ethyl ether and dried in vacuum in a desiccator.
d) Synthesis of 1-(5-carboxypentyl)-1′-propyltrimethoxysilane-3,3,3′,3′-tetramethyl-5,5′-disulfonate indodicarbocyanine potassium salt
12.14 mmol of the hemicyanine synthesised in the previous step were placed in a 250 ml round bottom flask, with 5.35 g (12.14 mmol) of N-propyltrimethoxysilane-2,3,3-trimethylindoleninium-5-sulfonate, 10.80 ml of triethylamine and 100 ml of acetic anhydride. The reaction mixture was heated at 135° C. for 2 hours. The solution was then cooled to r.t. and added dropwise to 800 ml of diethyl ether. The product was recovered on a filter, washed with diethyl ether and dried in vacuum in a desiccator. The product was then purified by flash chromatography on reverse silica (RP-C 18 ) with gradient elution (dichloro-methane/methanol from 90/10 to 70/30). Yield: 65%. The product has an absorption maximum centred at 655 nm (in water) and an emission maximum at 674 nm (in water).
EXAMPLE 3
Use of Compound 1 for the Preparation of Photoactive Mesoporous Nanoparticles
a) Preparation of the Mesoporous Material
The mesoporous material, of the MCM-41 type, was prepared according to the standard procedure disclosed in the literature (T. Mori, Y. Kuroda, Y. Yoshikawa, M. Nagao, S. Kittaka, Langmuir 2002, 18:1595), using cetyl trimethyl ammonium bromide (CTMAB) as the organic template.
b) Functionalization of the mesoporous material with Compound 1
The mesoporous material (hereafter MCM-41) was pre-treated by outgassing in at 150° C. for at least 4 hours, in order to remove physisorbed water. Then the material was impregnated with a solution of Compound 1 in anhydrous toluene (5 mg Compound 1 per 5 g of MCM-41). The suspension was stirred in Argon atmosphere for two hours. The material was then filtered and washed with solvents in order to remove dye molecules adsorbed on the outer surface of the mesoporous material. The product was then dried in oven at 150° C. (for the curing step, where the condensation of the silane termination of the fluorophore with the silanols of the MCM-41 occurs). After this stage, the fluorophore was covalently anchored inside the channels of the mesoporous material.
c) Reduction of the Fluorescent Mesoporous Material to Nanosize
The mesoporous material MCM-41, functionalized with Compound 1, was reduced to nanoparticles of homogeneous size (mean diameter 10 nm) by ultrasonication.
The nanoparticles thereby obtained were characterised by transmission electron microscopy and X-ray diffraction analysis; these measurements confirmed the maintenance of the mesoporous structure.
d) Surface Functionalization with Antibodies
Step 1: Coating of Nanoparticles with 3-aminopropyltriethoxysilane (APTES)
80 mg of MCM-41 nanoparticles were suspendend in anhydrous toluene; 400 μl of APTES were added to the suspension, which was stirred at r.t. for 4 hours. The material was then recovered by filtration, washed with toluene, then placed in an oven at 150° C. for the curing step.
Step 2: Exposure of Carboxyl Groups by Reaction of Surface APTES with Succinic Anhydride
The material obtained from step 1 of the present example was re-suspended in anhydrous toluene and stirred at 80° C. To this suspension, 0.8 g of succinic anhydride were added. The suspension was kept under stirring at 50° C. for 2 hours, then the solid was recovered through filtration and washed with toluene.
Step 3: Antibody Immobilization
The material obtained from step 2 of the present example was suspended in PBS buffer (0.1M pH 7.4) and stirred at r.t. EDC and subsequently 1 mg of antibody were then added to the solution. The reaction was carried out under stirring at r.t. for 2 hours. The material was recovered by centrifugation and washed with PBS buffer (0.1M pH 7.4) in order to remove unreacted antibodies.
EXAMPLE 4
Internalization and Citotoxicity Tests of Silica Nanoparticles from Example 3
Functionalized nanoparticles prepared as reported in Example 3 were used for cellular tests in order to assess their internalization and citotoxicity. To that purpose, a comparison with commercial fluorescent particles (FITC loaded Latex beads) was carried out.
A human neuroblastoma cell line (SHSY5Y) was used. The preliminary tests carried out showed that silica nanoparticles were quickly uptaken into the cells, where they were retained for up to 96 hours, whilst Latex beads were almost completely expelled after 1 hour. Silica nanoparticles maintained a high luminescence for all the duration of the test.
EXAMPLE 5
Use of Silica Nanoparticle from Example 3 for Visualization of Cellular Events
Functionalized nanoparticles prepared as reported in example 4 were used in cellular tests in order to monitor calcium regulated exocytosis. For endocytosis and exocytosis tests, RBL cells were used, that allow to study calcium regulated exocytosis of endosomes and lysosomes. Cells were incubated with a suspension of nanoparticles from example 3, in PBS buffer; after internalization, exocytosis was induced by administration of the calcium ionophore A23187. In order to better localize exocyted nanoparticles, a cell line stably transfected with chimeric protein cathepsin D-GFP (CD-GFP) was used, that allows to visualize endosomal and lysosomal compartments.
EXAMPLE 6
Use of 1-propyltrimethoxysilane-1′-propyltrimethoxysilane-3,3,3′,3′-tetramethyl-5,5′-disulfonate-indomonocarbocyanine potassium salt (IRIS3 sulfo silane, Compound 1) for the Preparation of Fluorescent Silica Nanoparticles
Compound 1 was used for the preparation of fluorescent silica nanoparticles in which compound 1 is covalently linked to the siliceous component, thanks to the presence of the silane groups. The preparation was carried out according to the following steps.
Step 1: preparation of the microemulsion according to a procedure reported in literature (Wang L. et al. Anal. Chem. 2006, 78 (3), 647-654). 75 ml of cyclohexane, 18 ml of n-hexanol, 5.4 ml of water and 17.7 ml of Triton X-100 were mixed.
Step 2: Addition of Compound 1 (6×10 −7 mol) dissolved in DMF.
Step 3: Addition of the silica precursor TetraEthylOrthoSilicate (TEOS, 1 ml) and ammonia solution (NH 4 OH 30%, 0.7 ml) to start the hydrolysis reaction to silicic acid and condensation reaction of the silicic acid monomers. The reaction was carried out for 18 hours under stirring at r.t.
Step 4: Nanoparticles extraction from microemulsion and washing with ethanol and water.
FIG. 2 shows the comparison between the fluorescence emission spectra of a solution of Compound 1, i.e. cyanine IRIS3 sulfo silane (- -) and an isoabsorbing suspension of silica nanoparticles containing the same cyanine IRIS3 sulfo silane (-). The emission of nanoparticles is 15-folds higher than the emission of the solution. Moreover, the photodegradation of fluorescent nanoparticles over time was compared to the photodegradation of the cyanine in solution. FIG. 3 shows the comparison graphs between the photodegradation of cyanine IRIS3 sulfo silane over time (Compound 1) in solution (●) and the same cyanine immobilized within a silica nanoparticle (∘). The graph shows the percentage of emission, compared to time zero, under excitation with a laser light at 532 nm. It observed that the cyanine immobilized within the nanoparticle undergoes a 5% photodegradation after 350 minutes, whilst the cyanine dye in solution undergoes a 45% photodegradation within the same time.
EXAMPLE 7
Synthesis of the Conjugate Between 1-(5-carboxypentyl)-1′-propyltrimethoxysilane-3,3,3′,3′-tetramethyl-5,5′-disulfonate indodicarbocyanine potassium Salt and the Protein Bovine Serum Albumin (BSA) (Compound 3)
a) Synthesis of the N-hydroxysuccinimidic Ester of Compound 2
115 mg (0.14 mmol) of Compound 2 were dissolved in lower possible amount of anhydrous N,N-dimethylformamide and placed into a 25 ml round bottom flask previously dried and maintained under an argon atmosphere. 64 mg (0.56 mmol) of N-hydroxysuccinimide and 115 mg (0.56 mmol) of Diciclohexylcarbodiimide were also placed into the round bottom flask. The round bottom flask equipped with a condenser, was placed to react into an oil bath pre-heated at 80° C. The reaction mixture was maintained under stirring for 4 hours at 80° C. under Ar atmosphere, after which the mixture was cooled at r.t. and added dropwise to 1 l of diethyl ether. The product was recovered by filtration on a sintered glass funnel, washed with ether and dried in vacuum in a desiccator.
b) Synthesis of the Conjugate with Bovine Serum Albumin
2 mg of Bovine Serum Albumin (BSA) were dissolved in PBS buffer (0.1M pH 7.4). 0.3 mg (3×10 −7 mol) of N-hydroxysuccinimide ester of Compound 2, dissolved in 50 μl of N,N-dimethylformamide, were added to the solution, achieving a 10/1 fluorophore/protein molar ratio. The mixture was stirred at r.t. for 2 hours. After 2 hours, the conjugate was purified on Sephadex G25 resin and the fractions containing the conjugate were lyophilized and stored at −20° C. in a refrigerator.
EXAMPLE 8
Immobilization of Compound 3 on the Surface of a Silica Nanoparticle
a) Preparation of the Silica Nanoparticle
Silica nanoparticles were prepared by following a microemulsion procedure reported in literature (Wang L. et al. Anal. Chem. 2006, 78 (3), 647-654), that lead to the formation of nanosphere of amorphous silica with a size of about 50 μm.
b) Immobilization of the N-hydroxysuccinimide Ester of Compound 2 on the Silica Nanoparticle
N-hydroxysuccinimide ester of Compound 2, prepared as reported in item a) of example 3, was dissolved in anhydrous N,N-dimethylformamide and added to a suspension of the nanoparticles in anhydrous toluene. The suspension was stirred at 80° C. for 15 hours, then the material was recovered by filtration and washed with anhydrous toluene, then it was maintained in oven at between 80-120° C. for 15 hours.
c) Immobilization of the N-hydroxysuccinimide Ester of Compound 2 on the Silica Nanoparticle
The nanoparticles functionalized as reported in the previous step were suspended in PBS buffer (0.1 M, pH 7.4). A BSA solution was added and the suspension was stirred for 2 hours at r.t., then the material was recovered by centrifugation and washed several times with buffer in order to remove the unreacted protein, if present.
EXAMPLE 9
Use of Compound 2 for the Preparation of Silicon Quantum Dots Functionalized with Fluorescent Molecules and Coated with a Silica Shell
a) Preparation of Functionalized Silicon Quantum Dots
Silicon quantum dots were prepared by electrochemical dissolution of porous silicon, and then functionalized with a convenient organic molecule that leads to the exposure of free amino groups on the surface.
b) Binding of Compound 2 on the Surface of Silicon Quantum Dots
Step 1: Synthesis of the N-hydroxysuccinimidic Ester of Compound 2
115 mg (0.14 mmol) of Compound 2 were dissolved in the lower possible amount of anhydrous N,N-dimethylformamide and placed into a 25 ml round bottom flask previously died and maintained under an Argon atmosphere. 64 mg (0.56 mmol) of N-hydroxysuccinimide and 115 mg (0.56 mmol) of Diciclohexylcarbodiimide were also placed into the round bottom flask. The round bottom flask, equipped with a condenser, was placed to react into an oil bath pre-heated at 80° C. The reaction mixture was carried out under stirring for 4 hours at 80° C. under an Ar atmosphere, after which the mixture was cooled at r.t. and added dropwise to 1 l of diethyl ether. The product was recovered by filtration on a sintered glass funnel, washed with ether and dried in vacuum in a desiccator.
Step 2: Immobilization of the N-hydroxysuccinimide Ester of Compound 2 on the Surface of Silicon Quantum Dots
To a suspension of silicon quantum dots in anhydrous N,N-dimethylformamide, a variable amount of N-hydroxysuccinimide ester of Compound 2, depending on the density of amino groups on silicon quantum dots surface, was added. The suspension was stirred for 2 hours and the material was recovered by centrifugation and washed with adequate solvents in order to remove unreacted fluorophore.
c) Deposition of the External Silica Shell
The molecules of Compound 2 immobilized on the surface of silicon quantum dots can be exploited as anchoring moieties for the coating of quantum dots with different type of siliceous precursors (TEOS, TMOS, etc.), in an acidic or alkaline hydrolysis and condensation reaction, similar to that described in steps 3 and 4 of example 5. | A silane-modified cyanine of Formula (I) includes the valence tautomers thereof: wherein R 1 is a linear, saturated or unsaturated alkyl chain, having 1 to 30 carbon atoms, wherein one or more carbon atoms are optionally substituted by a 4-, 5- or 6-membered aromatic or non aromatic cyclic grouping of carbon atoms; R 8 and R 9 are independently selected from the group consisting of —OCH 3 , —OCH 2 CH 3 , —OCH 2 CH 2 CH 3 , —OCH(CH 3 ) 2 , —OCH 2 CH 2 OCH 3 , —Cl, —Br, —I, Formula (II), Formula (III), —N(CH 3 ) 2 , Formula (IV), Formula (V), methyl, ethyl, propyl, isopropyl. The synthesis method and the use as a fluorescent marker are for inorganic solid supports, for example silica nanoparticles, and/or for biomolecules such as peptides, antibodies, DNA, RNA, etc. | 2 |
BACKGROUND OF THE INVENTION
The invention relates to an X-ray photographic apparatus comprising a photographic installation, comprising supply magazines for image layer carriers of varying format, comprising a transport path transporting the image layer carriers between rollers, bearing in a resilient fashion on both sides of said image layer carriers, from at least one receiving station associated with the supply magazines to the photographic exposure station, and to a release station.
In X-ray technology, it is general practice to transport the individual film sheets between transport rollers--disposed one on top of the other in a resilient manner--or between conveyer belts from one supply magazine to a photographic exposure station, and, following exposure, again from the photographic exposure station to a collector magazine. In so doing, one constantly endeavors to have the transport rollers run only along the border, and not, however, over the image (or picture) area, because, in the case of certain atmospheric humidities, electrostatic charge patterns are produced as a consequence of sliding and rolling friction which, upon development of the film material, are reproduced in the form of interfering line patterns, so-called lightening distortions.
From an X-ray photographic apparatus, disclosed in the German AS No. 11 93 799 (FIGS. 4, 5 and 6), wherein film sheets of varying size format are transported to a photographic exposure station, it is known to transport the film sheet along one single edge between transport rollers, bearing resiliently against one another, to the photographic exposure station and from the photographic exposure station to a collector magazine common to all formats. However, in the case of this solution, it is considered disadvantageous that it is possible to operate with only relatively low transport speeds and thus with low photographic exposure frequencies, because otherwise the film sheets would become canted on account of the eccentric action of the acceleration forces.
It has already been proposed to utilize transport paths wherein the track widths of the transport rollers associated with the two marginal regions of the film sheets are jointly adjusted during the selection of the film format. However, a considerable technical outlay would be connected with this procedure. Moreover, the photographic exposure repetition rate (or frequency) could not have been substantially increased on account of the time required for the track gauge adjustment.
SUMMARY OF THE INVENTION
Accordingly, the object underlying the invention consists in pointing out a way by means of which film sheets of varying size format can be transported at a high speed into X-ray photographic apparatus without lightening distortion (due to the electrostatic charge effects) becoming visible.
In the case of an X-ray photographic apparatus of the type initially cited, accordingly, in accordance with the invention, the rollers disposed on different sides of the transport plane are axially offset (or staggered) relative to one another by at least one roller-width, the track gauges of the rollers are adapted (or matched) in pairs to the spacing between edges (oriented parallel to the transport direction) of each format to be transported, and the rollers associated with the respectively smaller format are kept smaller in their diameter as well as being arranged more closely to the center of the transport path than the rollers associated with the larger formats. It is thereby possible to transport image layer carriers of varying size format with one single transport path. They are seized only at their opposite edges (or borders), not, however, in the image region. Thus, due to the two-sided support-mounting of the image layer carriers, the prerequisite is provided for the transmission of high accelerations and high photographic exposure frequencies, and protective transport is likewise insured due to the lack of contact with the image layer. Also, expensive apparatus for adaptation of the track to the selected formats thus become unnecessary.
In an advantageous embodiment of the invention, the mutually parallel shafts for the rollers, arranged on opposite sides of the transport plane, can be arranged in pairs, respectively, vertically one above the other. As a consequence of this, it is possible to press the rollers against the image layer carriers with relatively high pressure force and transmit high accelerations.
In an expedient further development of the invention, the rollers oppositely disposed to one another on both sides of the transport plane, associated with the respectively smallest format to be transported, can be adjusted, deviating from the rollers associated with the remaining formats, without any axial offset (or staggering) relative to one another for the purpose of maintaining a minimal center distance. By this means, the rollers associated with the smallest format roll on top of one another when no image layer carrier is inserted therebetween at a given time. They thus prevent an excessive mutual interengagement of the remaining rollers which are axially offset (or staggered) relative to one another. The latter instance would obstruct the introduction of the film sheets between the rollers. Thus, the rollers associated with the smallest format simultaneously ensure that the rollers, which are axially offset (or staggered) relative to one another, and arranged on the opposite shafts offer comparatively little resistance to the insertion of the film sheet.
A considerable simplification of the construction ensues if the rollers of each format associated with the two marginal regions on each side of the transport plane are arranged on a common shaft. The number of shafts and bearing can hereby be significantly reduced without any functional impairment of the transport path whatsoever.
The mutual spacing between the pairs of rollers perpendicular to the transport direction, and thus the outlay for the transport path can be further reduced if, in a particularly expedient further development of the invention, the transport plane is undulated in the transport direction. This has a consequence, the fact that the transverse stability of the individual image layer carriers is increased due to the slight curvature. The sagging (or dipping) of the larger formats in the direction of the central rollers associated with the smaller formats is thereby prevented.
Further details of the invention shall be explained in greater detail on the basis of the sample embodiments illustrated in the Figures; and other objects, features and advantages will be apparent from this detailed disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic illustration of an X-ray photographic installation partially opened-up;
FIG. 2 shows the axial arrangement of the rollers; and
FIG. 3 shows the alignment of the shafts relative to the transport plane in the case of another longer transport path.
DETAILED DESCRIPTION
In FIG. 1, an X-ray photographic installation 2 can be recognized arranged beneath a patient support 1. In the opened-up housing 3 of the X-ray photographic installation 2, there is disposed an X-ray image intensifier 4 with a mounted-on television camera 5. On the right side of the X-ray photographic installation, in FIG. 1, three supply magazines 6, 7, 8, for varying size film formats can be recognized, and on the left side of the X-ray photographic installation 2, a collector magazine 9 for the exposed film sheets 10, 11, 12, 13, can be recognized. There is disposed, directly in front of the side of the X-ray image intensifier 4 facing the patient support 1, the photographic exposure station 14 for the film sheets. The supply magazines 6, 7, 8, the photographic exposure station 14, and the collector magazine 9, are interconnected via a transport path 15. This transport path consists of a plurality of shafts 16, 17, 18, 19, 20, 21, 22, 23, arranged in pairs one above the other, with the rollers 24 through 45 for the transport of the film sheets 10, 11, 12, 13, 46, 47, 48. The gaps between the individual pairs of shafts are bridged by film-guide metal sheets 49, 50, 51, 52.
FIG. 2 illustrates the arrangement of the individual rollers 26, 27, 32 through 45 on the shafts 18, 19, arranged on both sides of the transport plane. The arbors are mounted in bushings 53, 54, 55, 56, which are guided in frame 57 for the transport path 15. Whereas the two lower bushings 55, 56, in FIG. 2 are fixedly mounted in frame 57 of the transport path 15, the upper bushings 53, 54, in FIG. 2, are guided in frame 57 such as to be displaceable in height. The two upper bushings 53, 54, are pressed by means of one spring 58, 59, each in the direction of the lower bushings 55, 56. The lower shaft bears three roller pairs with respectively varying roller diameters. The mutual spacings between the rollers 27, 34, 37, 39, 41, 44 of each roller pair of the lower shaft 19 coincide precisely with the distances of the lateral borders or edges of the film sheets 46, 47, 48, to be transported. The rollers have approximately one-third of the width of these edges. There are associated, with each of the rollers of the lower shaft 19, two rollers 26, 32, 33, 35, 36, 38, 40, 42, 43, 45, on the upper shaft 18, which are arranged on the upper shaft in such a manner that the corresponding roller of the lower shaft 19 can interengage precisely between them. Only the smallest rollers 36, 37, 38, 39, of the two shafts 18, 19 are arranged such that they are precisely oppositely disposed one another and roll on top of one another if no film sheet is transported between them at a given time.
One pulley 60, 61, each (FIG. 2) is mounted on the sides (facing the bushing 53, 54) of the outermost rollers 26, 45 of the upper shafts 16, 18, 20. Over these pulleys, endless cables 62, 63 are tensioned, which couple each of the upper shafts 16, 18, 20 with the respectively next upper shaft and with a drive motor 64. In the region of the photographic exposure station 14; i.e., in radiation direction before the X-ray image intensifier (FIG. 1), no shafts are arranged. Instead, the rollers 28, 29, 30, 31, corresponding to one another, disposed immediately at the right and at the left of the photographic exposure station 14, are each wrapped by an endless belt 65, 66, which can be readily permeated by radiation. Since the frontal side of the X-ray image intensifier 4 is brought close to the transport plane, the lower sections of the belts, which are capable of irradiation, of the two lower shafts 21, 23, slide over the X-ray image intensifier 4.
FIG. 3 illustrates, on the basis of a longer transport path 67, how the rollers 68, 69, 70, 71, 72, 73, 74, 75, arranged at both sides of the transport plane, are offset somewhat upwardly and downwardly alternately in pairs, such that the transport plane in transport direction forms a slightly serpentine (or wavy) line. The interstices between the roller pairs are filled out with funnel-shaped converging film-guide metal sheets 76, 77, 78, 79, 80, 81.
If, in order to retain a medical diagnostic finding ascertained by means of the X-ray image intensifier-television chain, the supply magazine 6, 7, 8, is selected with the film format suitable for this purpose, then the removal apparatus--not further illustrated here--of the selected supply magazine ejects a film sheet. With the selection of the film format, the drive motor 64 for the rollers 24 through 45 is also simultaneously switched on. If an intermediate film format were to be selected, the central supply magazine 7 would press this film sheet between the rollers 26, 27, mounted on the shafts 18, 19. Due to the film sheet, the upper shaft 18 with the rollers 26, 32, 33, 35, 36, 38, 40, 42, 43, 45 (FIG. 2) would be raised somewhat counter to the force of the two springs 58, 59. Since the supply magazines 6, 7, 8 are centered relative to the center of the transport path 15, the film sheet is seized at its two marginal regions by the rollers 33, 34, 35, 40, 41, 42, and transported into the photographic exposure station 14. Since the rollers 36, 37, 38, 39, for the next-smaller film format, arranged further toward the center of the shafts 18, 19, are also kept smaller in their diameter, they cannot touch the emulsion layer of the larger film format. The sagging of the larger film formats onto these smaller rollers 36 through 39, mounted near the center of the shafts 18, 19, is prevented by virtue of the fact that the transport plane is slightly undulated in the transport direction due to the alternate higher and lower bearing of the lower shafts 17, 19, 21, as is illustrated on the basis of FIG. 3 and rollers 69, 71, 73, 75. Due to this slight waviness, the film sheets are also bent somewhat. Their stiffness transversely to the direction of curvature thus increases considerably. In any case, this effect is totally sufficient in order to prevent a sagging of the central regions of the film sheets onto the smaller rollers.
Through the funnel-shaped film-guide metal sheets 49, 50, 51, 52, the film sheets are repeatedly threaded between the next-following roller pairs. As a consequence of the mutual inclination of the film-guide metal sheets, when a minimum aperture angle of approximately 20° has been attained, it is then possible for the film sheets 82 to touch these guide metal sheets 76 through 81 only with their front, non-sensitive edges and not, however, with their image layers. Upon reaching the photographic exposure station 14, the drive motor 64 for the rollers is switched "off" via an infrared-light barrier--not illustrated here--which scans the edge of the film sheets. After exposure has taken place, the drive motor for the rollers is again switched "on" for a short period of time via a time switch, likewise not further illustrated. In so doing, the respectively exposed film sheet is further transported to the collector magazine 9.
It would also be possible to center the supply magazines not relative to the center of the transport path, but relative to a lateral edge of the transport path. The advantage connected herewith would consist in that, on this side of the transport path, a single vertically aligned roller pair would be required with rollers at the opposite sides of the transport plane, which roller pair would be associated with the marginal region of all formats. Further, rollers (of graduated diameter and axially offset) such as are indicated in FIG. 2, would then be necessary only for the other lateral side of the transport path. However, the drawback which would stand in the way of this advantage would be that the photographic exposure region would no longer be disposed centrically relative to the fluoroscopy field; i.e., centrically relative to the inlet fluorescent screen of the X-ray image intensifier.
It will be apparent that many modifications and variations may be effected without departing from the scope of the novel concepts and teachings of the present invention. | In an exemplary photographic exposure installation, supply magazines for image sheets of varying format are provided with a transport path for transporting the image sheets between rollers bearing in a resilient fashion against both sides of the image sheets. The rollers disposed on different sides of the transport plane are axially offset relative to one another by at least one roller-width, the track gauges of the rollers are adapted in pairs to the distance between the lateral borders of each format to be transported, and the rollers associated with the smaller formats are smaller in their diameter as well as being arranged more closely to the center of the transport path than the rollers associated with the larger format. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims priority to U.S. Provisional Patent Application Ser. No. 62/206,842, entitled “Fuel primer and pump bulb bypass apparatus for outboard engines”, filed on Aug. 18, 2015, the disclosure of which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The field of the invention pertains to a priming system for an internal combustion engine and more particularly to a priming system which allows an alternate direct path between the fuel source and the fuel intake of an internal combustion engine
[0003] It is well know that flexible priming bulbs, which are manually squeezed to pump fuel from the fuel source to the intake of an internal combustion engine can fail over time. This failure can cause the fuel flow from the fuel source to the engine to be obstructed either partially or completely thus starving the engine of fuel causing either a reduction in revolutions per minute or complete engine failure.
SUMMARY OF THE INVENTION
[0004] In accordance with the present invention, there is provided a means to prevent the obstruction of fuel flow from the fuel source to the intake of an internal combustion engine by having an alternate path for fuel to flow between the fuel source and the intake of an internal combustion engine. This invention takes advantage of prior art using existing fuel system primer to pump fuel from the fuel source to the fuel flow intake of an internal combustion engine then after the engine is primed with fuel an adjacent but connected fuel line is available creating an alternate fuel path from the fuel source to the fuel intake of the internal combustion engine
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The present invention is illustrated by way of example and is not limited by the accompanying figures, in which like references indicate similar elements. Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale.
[0006] FIG. 1 is a perspective view of a Fuel priming pump utilizing a shut off valve FIG. 1 # 3 .
[0007] FIG. 2 is a perspective view of a Fuel priming pump utilizing a unidirectional check valve FIG. 2 # 3 .
DETAILED DESCRIPTION
[0008] Unlike Other solutions in which the fuel priming systems have no redundancy in fuel flow to prevent failure caused by age, or malfunction of the primer bulb # 7 , the presently claimed invention provides an alternate, more direct route between the fuel source and the fuel intake of an internal combustion engine.
[0009] Further, the presently claimed invention prevents mechanical failure of the internal combustion engine due the failure of the manual fuel primer bulb # 7 .
[0010] Still further, the presently claimed invention allows fuel to be manually pumped from the fuel source to the fuel intake of an internal combustion engine
[0011] 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 the present invention. Any benefits, advantages or solutions to problems described herein with regard to specific examples are not intended to be construed as a critical, required or essential feature or element of any or all the claims.
[0012] The Detailed Description section, and not the Abstract section, is intended to be used to interpret the claims. The Abstract section may set forth one or more but not all examples of the invention, and the Abstract section is not intended to limit the invention or the claims in any way.
NON-LIMITING TERMINOLOGY
[0013] The terms “a” or “an,” as used herein, are defined as one or more than one.
[0014] The use of introductory phrases such as “at least one” and “one or more” in the claims should not be construed to imply that the introduction of another claim element by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim element to inventions containing only one such element, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an.” The same holds true for the use of definite articles.
[0015] The term “coupled,”, as used herein, is defined as “connected” although not necessarily directly.
[0016] The term “fuel line clamp” as used herein, includes multiple spring steel, plastic or radiator type fuel line securing hose clamps.
[0017] The term “T and Y connector” as used herein, is defined as a fuel line connector with at least one fuel line connection for input and at least one fuel line connection for output, It may be flexible or rigid, connection end where fuel line attaches may be threaded or barbed, composed of metal or a fuel tolerant plastic, PVC, or neoprene material.
[0018] The term “fuel line” as used herein, is defined as any type of rigid or flexible, metal, plastic, PVC, or rubber type of fuel tolerant tubing.
[0019] The term “pump” as used herein, is defined as any type of manual or electric, flexible or rigid device that sucks fluid in at least one opening and propels fluid out through at least one different opening.
[0020] unless stated otherwise, terms such as “first” and “second” are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements.
First Example of Fuel Primer Pump
[0021] Turning now to FIG. 1 and FIG. 2 , wherein like numerals indicate like or corresponding parts throughout the views, a Fuel priming pump for introducing starting fuel into the intake system of an internal combustion engine and maintaining fuel flow to the intake system of an internal combustion engine in the event that that the fuel primer bulb # 7 fails. The assembly comprises of two T and Y connectors # 1 ,# 2 , for attaching fuel line in sizes between but not limited to 0.25 inch (0.635 cm) and 1 inch (2.54 cm). Four sections of fuel line between the sizes but not limited to 0.25 inch (0.635 cm) and 1 inch (2.54 cm) # 4 ,# 5 ,# 6 ,# 8 . A fuel primer bulb # 7 as well as either a unidirectional check valve FIG. 2 . # 3 , or a shut off valve FIG. 1 . # 3 which can be manually opened and closed. It also includes multiple spring steel, plastic or radiator type fuel line clamps # 9 which are used to securely fasten the fuel line segments # 4 ,# 5 ,# 6 ,# 8 to the T and Y fuel line connectors # 1 ,# 2 , as well as the fuel primer bulb # 7 , and the Fuel shut off valve FIG. 1 . # 3 or the unidirectional check valve FIG. 2 . # 3 .
[0022] The Fuel priming pump allows fuel to travel between the fuel source and the intake system of an internal combustion engine via 2 pathways, The traditional fuel path # 10 , through the fuel primer bulb and an alternate pathway # 12 , which bypasses the fuel primer bulb # 7 .
[0023] Operation of the fuel priming pump, involves priming the internal combustion engine with fuel. During this operation the Fuel shut off valve FIG. 1 . # 3 is manually set to the closed position blocking the back flow of fuel to the fuel source via the alternate fuel path # 12 , if a unidirectional check valve is used FIG. 2 . # 3 then no manual manipulation is required. The fuel priming bulb # 7 is then manually activated pumping fuel from the Fuel source through the first T and Y connector # 1 , it then travels through fuel line # 6 , into the fuel priming bulb # 7 . The fuel then exits the fuel priming bulb # 7 to fuel line # 8 which connects to the second T and Y connector # 2 , which follows the fuel path # 10 . The Fuel will then exit the Fuel priming pump and travels to the intake system of the internal combustion engine to prime the engine. The Fuel cannot back flow through fuel line # 5 because the shut off valve FIG. 1 # 3 is closed, or a unidirectional check valve FIG. 2 . # 3 is in place to prevent back flow of fuel away from the intake system of the internal combustion engine.
[0024] Once the internal combustion engine is primed then the fuel shut off valve FIG. 1 # 3 , is manually placed in the open position allowing an alternate fuel path# 12 , to the intake of the internal combustion engine, if a unidirectional check valve FIG. 2 . # 3 , is used in place of the manual fuel shut off valve FIG. 1 . # 3 , then no manual manipulation is needed to create an alternate Fuel path # 12 . Two independent fuel paths are available fuel path # 10 , and fuel path # 12 , thus allowing redundancy in the event of fuel flow obstruction caused by the failure of the fuel priming bulb # 7 .
Non-Limiting Examples
[0025] Although the invention is described herein with reference to specific examples, various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below.
[0026] Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.
[0027] Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims. | A means to prevent the obstruction of fuel flow from the fuel source to the intake of an internal combustion engine by having an alternate and path for fuel to flow between the fuel source and the intake of an internal combustion engine. This invention takes advantage of prior art using existing manual fuel system primer to pump fuel from the fuel source to the fuel intake of an internal combustion engine then after the engine is primed with fuel an adjacent but connected fuel line is then available creating an additional fuel path from the fuel source to the fuel intake of the internal combustion engine. | 5 |
[0001] The present invention relates to a method for obtaining antireflective coatings by the sol-gel technique on glass or plastic substrates. This coating increases the transmittance of the transparent substrates on which it is applied, so it is useful to apply to high concentration solar modules (HCPV), both in primary and secondary lenses, in conventional silicon or CSP tubes in thermoelectrics. Additionally, in glass windows of tower receivers.
[0002] Therefore, the invention could be framed in the field of solar and thermoelectric energy devices.
STATE OF THE ART
[0003] Solar collectors require an outer glass cover which reduces the optical losses of light transmission. To solve this problem and increase the performance of a system, a coating with a predetermined thickness on a substrate whose transmittance varies between 0.90 and 0.92 is used, so that the transmitted light lost varies between 8 and 10% of the incident solar radiation. In order to reduce these losses antireflective coatings prepared by different techniques are used. For a glass substrate with a refractive index of 1.45, a coating or an antireflective coating with a lower rate should be used, so that the result is a reduction in transmission losses.
[0004] The sol-gel technology has been a breakthrough in the field of coatings. This technique allows the preparation of complex formulations of inorganic oxides at room temperature obtained from liquid components which, by chemical reactions, take a solid structure (thin film) used for coating substrates, highlighting its strength and good optical properties.
[0005] There are several commercial coatings applied using sol-gel technology used in the field of solar energy. Document EP1329433A1 discloses sol-gel preparation of porous coatings by immersion or spray on different substrates using high concentrations of Triton® and subsequent heat treatment to burn Triton T ®. These coatings require curing at high temperatures (400-600° C.) to burn the surfactant and achieve mechanical stability.
[0006] Document EP1074526A2 describes the sol-gel preparation of antireflective and levelling film on substrates of glass/tin oxide by immersion. These coatings are oriented to coat conductive tin oxide whose application on glass substrates would not result in an antireflective coating.
[0007] Document U.S. Pat. No. 5,580,819A describes sol-gel preparation of antireflectants with different functional groups on solid substrates, curing and treatment with aqueous electrolyte solution to produce porosity. This procedure allows to obtain hybrid sol-gel films of a strong organic nature spoiled using electrolytes to achieve porosity, although these coatings are not suitable for outdoor use.
DESCRIPTION OF THE INVENTION
[0008] The present invention describes the preparation of a coating with antireflective properties by a sol-gel process, to be subsequently applied to solar collectors by spray technique to optimize its light transmission, and thus increasing system efficiency. The main advantage of the method described, in comparison with other techniques for preparing antireflective coatings, is the versatility of the technique which allows to achieve optimal formulation to acquire the desired optical characteristics with good photochemical properties and mechanical and chemical stabilities against environmental agents.
[0009] The physicochemical characteristics of the coating allow its application on the collectors by spray technique, which represents several advantages over other techniques such as immersion, which is currently the most widely used for CSP tube coating, for example. As is known, spray application is simpler, it allows working with small pieces and is an automated process that does not require more complex equipment or processes like vacuum or evaporation. Also, the utilization of deposition techniques by centrifugation results on obtaining less homogeneous coatings.
[0010] Therefore, a first aspect of the invention relates to a sol-gel method for obtaining an antireflective coating comprising the following steps:
[0000] a) Preparing a solution by mixing a compound of formula (I)
[0000]
[0000] with a compound of formula (II)
[0000]
[0011] wherein R 1 , R 2 , R 3 and R 4 are linear or branched, identical or different C 1 -C 6 alkyl groups; and R 5 , R 6 , R 7 and R 8 are identical or different and are selected from linear or branched C 1 -C 6 alkyl groups or linear or branched C 1 -C 6 alkoxy groups, and wherein at least one group R 5 , R 6 , R 7 or R 8 is an alkyl group;
[0012] in a medium comprising water, a C 1 -C 4 alcohol and an inorganic acid, letting it hydrolyse for 1 to 10 hours at a temperature of between 50 and 100° C., preferably at a temperature of between 60 to 90° C. and more preferably for a time of 2 to 5 hours.
[0000] b) addition of a natural oil and a non-ionic surfactant to the solution obtained in (a), letting it hydrolyse for 1 to 10 hours at a temperature of between 50 and 100° C., preferably at a temperature of between 60 and 90° C. and more preferably for from 2 to 5 hours.
[0013] In the present invention “alkyl” is understood as aliphatic chains, either linear or branched, having 1 to 10 carbon atoms, for example methyl, ethyl, n-propyl, i-propyl, n-butyl, tert-butyl, sec-butyl, n-pentyl, n-hexyl, etc. Preferably the alkyl group has from 1 to 6 carbon atoms. More preferably, methyl, n-ethyl, n-propyl, n-butyl. The alkyl groups may be optionally substituted by one or more substituents such as halogen, hydroxyl, azide, carboxylic acid or a substituted or non-substituted group selected from amino, amido, carboxylic ester, ether, thiol, acylamino or carboxamide.
[0014] In the present invention “alkoxy” is understood as a group of formula —OR a wherein R a is an alkyl as described above. Preferably, the term alkoxy refers to methoxy, ethoxy or propoxy.
[0015] In the present invention “alcohol” is understood as an alkyl group as described above comprising at least one —OH group as a substituent of a carbon, either terminal or intermediate. Preferably, the alcohol is methanol, ethanol or propanol.
[0016] In a preferred embodiment, R 1 , R 2 , R 3 and R 4 are a C 1 -C 4 alkyl, either identical or different. In a more preferred embodiment, R 1 , R 2 , R 3 and R 4 are ethyl.
[0017] In another preferred embodiment, at least one of R 5 , R 6 , R 7 or R 8 is a C 1 -C 2 alkyl. In a more preferred embodiment, at least one of R 5 , R 6 , R 7 or R 8 is methyl.
[0018] In another preferred embodiment, at least one of R 5 , R 6 , R 7 or R 8 is C 1 -C 4 alcoxy, either identical or different. In a more preferred embodiment, at least one of R 5 , R 6 , R 7 or R 8 is ethoxy. In another more preferred embodiment, wherein R 5 is methyl and R 6 , R 7 and R 8 are ethoxy.
[0019] In another preferred embodiment, the C 1 -C 4 alcohol used in step (a) is ethanol.
[0020] The inorganic acid used in step (a) can be any inorganic acid known by one skilled in the art such as hydrochloric acid, sulphuric acid, nitric acid or phosphoric acid, but nitric acid is preferably used.
[0021] The natural oil of step (b) can be any natural oil known by one skilled in the art such as castor oil, olive oil, sunflower oil, argan oil, coconut oil, walnut oil, almond oil, hemp oil, marigold oil, borage oil, etc. or mixtures thereof. But preferably castor oil is employed.
[0022] The non-ionic surfactant may be any known by one skilled in the art such as, but not limited to, those of the following types: Lutensol®, Basoclean®, Basorol®, Basosol®, Triton®, Brij® or Tween®.
[0023] In a preferred embodiment the molar ratio between the compounds of formula (I) and (II) is between 2.5:1 and 3.5:1, the molar ratio between the compounds of formula (I) plus (II) and C 1 -C 4 alcohol in step (a) is between 1:3 and 1:4. The molar ratio between the compounds of formula (I) plus (II) and water is between 1:1.8 and 1:2.2. The molar ratio between the compounds of formula (I) plus (II) and the inorganic acid is between 1:0.1 and 1:0.15. The molar ratio between the compounds of formula (I) plus (II) and the surfactant is between 1:0.10 and 1:0.15. The molar ratio between the compounds of formula (I) plus (II) and the oil is between 1:0.04 and 1:0.05.
[0024] The antireflective film formed by the method described above improves the light transmittance of solar glass used as substrate. As a representative case, it can be indicated that the transmittance increases from 91.4% (600 nm) to 94% when the coating is carried out on one side or 97.6% when performed on both sides. Applying the coating on one side of the glass has rendered a 5% improvement in current intensity measured in a photovoltaic cell (see FIG. 1 ). This increase in intensity is directly proportional to the increase of light received by that cell. This results in a considerable improvement when it comes to performance of solar concentrator lenses.
[0025] Regarding photochemical stability, it should be noted that the durability of the coating is very high as it is seen in the degradation tests of example 2, wherein it is shown that the coatings have a degradation against solar radiation which is minimal. After the direct exposure of the samples to sunlight, only a decrease of 0.50-0.60% transmittance in wavelength of 600 nm or less than 0.22% in wavelength of 800 nm is observed, as shown in FIG. 2 . This is equivalent to an average decrease of 0.55% of absolute transmittance of the coated substrate with respect to its initial value. FIG. 2 shows a comparison with the optical transmission of the substrates before and after degradation experiments
[0026] In a second aspect, the present invention relates to an antireflective coating obtainable according to the method described above and characterized in that it presents a refractive index of between 1.2 and 1.3 and preferably about 1.25.
[0027] In a preferred embodiment, the antireflective coating has a thickness of between 80 and 200 nm and preferably about 160 nm.
[0028] In third aspect the present invention relates to an optical or thermoelectric device comprising at least one layer of the coating described above.
[0029] The coating of the present invention is applicable to any thermoelectric or optical device used in solar energy facilities and that requires improved efficiency reducing losses through refraction. Preferably these devices are selected from high-concentration solar modules, silicon panels or CSP tubes.
[0030] In a fourth aspect, the present invention relates to a method for obtaining the device described above comprising the following steps:
a) Application of the antireflective coating obtained by the method described by spray technique on a substrate. b) Curing the film applied in the previous step at a temperature of 90-200° C. for a time of between 10 to 60 minutes, preferably at a temperature of 95-150° C. for 12 to 30 minutes.
[0033] Preferably, an additional step of curing the product obtained in (b) at a temperature between 200 to 400° C. is performed for a time of 5 to 15 hours, preferably between 100-350° C. for 7 to 13 hours.
[0034] When the structure and characteristics of the substrate allow it, it can be coated on both sides.
[0035] The substrate may be any transparent material known by one skilled in the art with suitable physicochemical characteristics for the sufficient adhesion of the antireflective coating. Non-limiting examples of suitable substrates are glasses, glass, silicon or plastics.
[0036] Throughout the description and claims the word “comprise” and its variations are not intended to exclude other technical features, additives, components or steps. For those skilled in the art, other objects, advantages and features of the invention will arise partly from the description and partly from practice of the invention. The following examples and figures are provided by way of illustration, and are not intended to limit the scope of the present invention.
DESCRIPTION OF THE FIGURES
[0037] FIG. 1 shows the transmission spectra of the substrates without the antireflective coating, and with the coating on one and on both sides of the substrate (A). For clarity the part of interest of the figure has been enlarged (B).
[0038] FIG. 2 shows the transmission spectra relating to the durability of the coating against solar radiation. Before exposing the coating to the sun, after 9,120 h and after 14,400 h. Also, uncoated substrate spectra before and after irradiation are shown.
EXAMPLES
[0039] The method of preparation and processing of the antireflective treatments and assays conducted demonstrating the advantageous properties are shown below.
Example 1
Preparation of Antireflective Coating and Deposition on Glass Substrates
[0040] First, the sol solution was prepared by mixing 2.147 μl of TEOS (tetraethyl orthosilicate) with 639 μl of MeTES (Tri-ethoxy-methylsilane) 2,637 μl of absolute ethanol, 462 μl of deionized H 2 O and 114 μl of nitric acid 60%. It is mixed with continuous stirring and this sol is hydrolysed for 3 hours at 65° C. in thermostatic bath at 300 rpm. 5 ml of the hydrolysed sol are taken adding 436 mg of castor oil and 10 ml of Brij56 (non-ionic surfactant) dissolved in ethanol (11.2% m/m); they are vigorously mixed and re-hydrolysed for 3 hours at 65° C. in water bath at 300 rpm. Then allowed to cool at room temperature for a few minutes.
[0041] Then we proceed with the deposition by spray technique of the sol-gel previously obtained to form the antireflective film. First we proceed to the cleaning of glass substrates to be deposited with ethanol. Then we prepare a dilution 1:2 of sol hydrolysed and tempered in ethanol (per ml of sol 2 ml of ethanol are added) and the dilution is introduced into the deposit of the spray gun which is fixed 11 cm from the sample holder. The sample is placed in the centre of the sample holder passing below the gun, in the centre of the spray pattern, and we proceed to deposit on the substrate. Finally the solvent is allowed to evaporate for 10 seconds in air and the sample is removed to deposit onto the next.
[0042] Finally, we proceed to the curing of the antireflective film deposited by introducing the samples at 100° C. for 15 minutes in an oven or furnace. Additionally, a second curing at 300° C. for 10 hours may be done. This enables an optimal drying of the coatings without deterioration of the initial chemical formula, besides significantly improving the mechanical properties.
[0043] Characterization of films deposited using modelling software based on the transmittance spectrum of the sample exhibits porous coatings of about 160 nm thick with a refractive index between 1.2 and 1.25.
Example 2
Measurement of the Transmittance of the Coated Substrates Obtained in Example 1
[0044] Subsequently, the transmittance depending on the wavelength of the coated substrates obtained in Example 1 was measured by using a Cary 50 UV spectrophotometer. The substrates coated on both sides were also measured. The data obtained are shown in FIG. 1 . As mentioned above, said transmittance increases from 91.4% (600 nm) to 94% when the coating is carried out on one side or to 97.6% when performed on both sides.
Example 3
Photochemical Stability Test of the Coated Substrates Obtained in Example 1
[0045] To test the photochemical stability of the coated substrates a solar simulator is used that reproduces the spectrum of sunlight and focuses the light to accelerate the measurement. Coated glass substrates obtained in Example 1 are exposed to radiation for 45 days at a temperature of 120° C. receiving a concentrated source of radiation equivalent to “10× Suns” which is equivalent to 600 days of solar irradiation or 14,400 hours of direct sunlight irradiation at 1 sun. FIG. 2 shows how the percentage of transmittance is virtually unchanged (average decrease of 0.55% absolute transmittance of the coated substrate with respect to the initial values) despite being exposed for over 14,400 hours.
Example 4
Measurement of the Efficiency of Uncoated Optical Systems and Those Coated with the Coating of the Invention
[0046] The intensity generated by an optical system was measured, particularly for a high-concentration photovoltaic module. A voltmeter was used as measuring instrument. The measurements were:
[0047] Without the antireflective treatment, 2.7 Amps were measured.
[0048] With the antireflective treatment, in the secondary lens of the high-concentration photovoltaic module, 2.85 Amps were measured.
[0049] The rise in current is directly proportional to the amount of light that reaches the secondary lens.
[0050] According to these data, the application of antireflective coating has rendered a 5% increase in the transmitted current intensity from the same captured radiation, which shows that this coating causes an increase in the efficiency of photovoltaic systems. | The invention relates to a sol-gel method for producing an anti-reflective coating from alcoxide-type precursors, that can subsequently be applied to glass or plastic substrates by spraying. The invention also relates to optical and thermoelectrical devices that have been coated with said anti-reflective material. This coating increases the transmittance of the transparent substrates over which it is applied, as a result of which it is useful to apply over high concentration solar modules (HCPV), for both primary lenses and secondary lenses, in conventional silicon or in CSP tubes. | 2 |
BACKGROUND
[0001] 1. Field of Invention
[0002] The invention relates generally to a system and method for handling a plug assembly. More specifically, the invention relates to a system and method for installing and/or removing a plug assembly from a tubing hanger subsea.
[0003] 2. Description of Prior Art
[0004] Subsea wellhead assemblies typically have a high pressure wellhead housing supported in a lower pressure wellhead housing and secured to casing that extends into the well. Usually one or more casing hangers land in the wellhead housing, where the casing hanger being located at the upper end of a string of casing that extends into the well to a deeper depth. A string of tubing generally extends through the casing for producing fluids from the well. Most assemblies include a production tree mounted to the upper end of the wellhead housing for controlling the well fluid. Production trees are typically large and heavy, having a number of valves and controls mounted thereon.
[0005] One type of tree, which is sometimes referred to as a “conventional” tree, includes a bore for production fluids and a tubing annulus access bore. Wellhead assemblies having conventional trees are formed by landing the tubing hanger in the wellhead housing. Tubing hangers in convention trees generally have a production passage, and an annulus passage that communicates with the tubing annulus surrounding the tubing. A flow circuit is defined through the tubing annulus and production tubing, circulating fluid through the circuit can be used to kill the well or to circulate out heavy fluid during completion.
[0006] Trees that are sometimes referred to as “horizontal” trees have a single bore in the tree, which is typically the production passage. A horizontal tree is landed before its corresponding tubing hanger is installed, then the tubing hanger is lowered and landed in the tree. The tubing hanger is lowered through the riser, which is typically a drilling riser. In another common type of wellhead system, a concentric tubing hanger lands in the wellhead housing in the same manner as a conventional wellhead assembly. The tubing hanger has a production passage and an annulus passage. However, the production passage is concentric with the axis of the tubing hanger, rather than slightly offset as in conventional tubing hangers and the tree does not have vertical tubing annulus passage. Tubing hangers in vertical trees are usually installed before the tree is landed on the wellhead housing. The tubing is typically run on a landing string through the drilling riser and BOP. Before the drilling riser is disconnected from the wellhead housing, a plug is installed in the tubing hanger as a safety barrier. The plug is normally lowered on a wireline through the landing string. Subsequently, after the tree is installed, the plug is removed through an open water riser that may be used to install the tree.
SUMMARY OF THE INVENTION
[0007] Provided herein is an example of a system for maneuvering a plug in and out of a tubing hanger disposed in a subsea wellhead assembly. In an example embodiment, the system includes a housing selectively coupled with the subsea wellhead assembly; where the housing has an end with an opening that is intersected by a chamber formed in the housing. A tractor is selectively deployed from within the housing that has an attached end effector. The plug is selectively coupled with the end effector, so that when the tractor is deployed from within the housing, the end effector handles the plug in the tubing hanger. In one example, the system further includes a reel mounted on the housing, a control line spooled on the reel that has an end attached to the tractor and is in selective communication with a remotely operated vehicle deployed subsea. An optional hot stab can be mounted on the housing for connecting to the remotely operated vehicle. In one optional example, the chamber registers with a main bore in the subsea wellhead assembly when the housing is coupled with the subsea wellhead assembly. The tractor in one example includes wheel members that project radially outward and into urging contact with an inner surface of the chamber when the tractor is in the housing and into urging contact with a main bore in the subsea wellhead assembly when the tractor is deployed from within the housing. An upper end of the chamber may optionally be subsea. In one embodiment, a seal is defined along an interface between the housing and the wellhead assembly.
[0008] Also provided herein is an example of a system for plugging a tubing hanger in a subsea wellhead assembly that in an embodiment includes a housing with an open end. In this example, the housing further includes a base at the open end that is sealingly attachable to the wellhead assembly and a closed end opposite the open end. A chamber in the wellhead assembly intersects the open end. A plug tooling assembly is selectively deployable from within the chamber. In an embodiment, the plug tooling assembly is made up of a tractor, an end effector mounted on the tractor, and a plug releasably connected to the end effector. The open end of the housing can attach to the wellhead assembly and the closed end may be disposed subsea. A control cable may optionally be included that provides power and control signals to the plug tooling assembly. In an example, the control cable has an end coupled with the plug tooling assembly and is in communication with a remotely operated vehicle disposed subsea. In an example embodiment, the control cable extends along a passage formed through the closed end and wherein packoffs in the passage define a pressure barrier between the cavity and ambient to the housing. Proximity sensors may optionally be set in the housing and the plug for determining a location of the plug in the housing.
[0009] Yet further provided herein is a method of handling a plug in a tubing hanger of a subsea wellhead assembly. In one example the method includes enclosing a tractor with an attached end effector in a housing, mounting the housing onto the wellhead assembly so that an upper end of the housing is submerged subsea, deploying the tractor and end effector from the housing into a main bore in the wellhead assembly, and handling the plug in the tubing hanger with the end effector. In one optional example of the method, the step of deploying the tractor involves engaging wheels on the tractor with an inner surface of the housing and an inner surface of the main bore. The method may further include deploying a remotely operated vehicle subsea, engaging a connector on the housing with the remotely operated vehicle, and controlling the tractor and end effector from the remotely operated vehicle through the connector.
BRIEF DESCRIPTION OF DRAWINGS
[0010] Some of the features and benefits of the present invention having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:
[0011] FIG. 1 is a side partial sectional view of an example of a plug installation package in accordance with the present invention.
[0012] FIG. 2 is a side partial sectional view of an example of the plug installation package of FIG. 1 being set onto a wellhead assembly in accordance with the present disclosure.
[0013] FIGS. 3 and 4 are side partial sectional views of an example of the plug installation package installing a plug in a tubing hanger of a wellhead assembly in accordance with the present invention.
[0014] While the invention will be described in connection with the preferred embodiments, 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 as defined by the appended claims.
DETAILED DESCRIPTION OF INVENTION
[0015] The method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout.
[0016] It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation. Accordingly, the improvements herein described are therefore to be limited only by the scope of the appended claims.
[0017] An example of a wellhead plug tooling package 10 is shown in a partial side sectional view in FIG. 1 ; which includes a housing 12 shown made up of a shroud 14 with a substantially cylindrical outer surface and a closed end 15 on its upper end. Opposite the closed end 15 is a connector 16 that also has a substantially cylindrical outer surface and an outer diameter extending radially outward past an outer diameter of the shroud 14 . In one example, connector 16 is a type conventionally used in subsea applications. A chamber 18 is shown extending axially through the shroud 14 and connector 16 which intersects an open end 19 disposed on a lower end of the connector 16 . Stowed within the chamber 18 is a plug tooling assembly 20 ; which in the example of FIG. 1 includes a tractor 22 having wheels 24 that selectively extend radially outward from an axis of the tractor 22 . An end effector 26 mounts on a lower end of the tractor 22 of FIG. 1 and is shown having a plug 28 is set on its lower end and on a side opposite where the end effector 26 connects with tractor 22 .
[0018] An optional control cable 30 is shown extending through a passage 32 , where the passage 32 is formed substantially axially through the closed end 15 . Examples of the control cable 30 include a wireline, slickline, cable, and other elements for deploying devices subsea and/or for conveying signals therein. Optional packoffs 34 are illustrated set coaxial within the passage 32 that extend from grooves in the wall of the passage 32 radially inward into the annular space defined between the control cable 30 and surfaces of the passage 32 . In one example of operation, the control cable 30 slides axially within the packoffs 34 , while the packoffs 34 provide a pressure barrier between the chamber 18 and area ambient to the housing 12 , so that when the wellhead plug tooling package 10 is disposed subsea, seawater is prevented from entering the chamber 18 while yet the control cable 30 is able to axially move within the passage 32 .
[0019] A reel assembly 36 mounts on the housing 12 over the closed end 15 and includes a spool 38 . A length of control cable 30 is shown rolled up on the spool 38 and the spool is supported on a frame 40 . Hot stabs 42 , 44 are shown set on the frame 40 and are configurable to be engaged by a remotely operated vehicle (ROV) 45 shown disposed adjacent the wellhead plug tooling package 10 . A spindle 46 is included with the frame that extends laterally between vertical members 47 that have lower ends that mount axially onto an upper surface of the closed end 15 . A signal line 48 is shown having an upper end terminating into and connecting with hot stab 44 ; the signal line 48 is disposed in a passage 50 shown extending axially a distance through the shroud 12 and into the connector 16 , then running radially inward within connector 16 and intersect with an inner surface of the chamber 18 . Proximity sensor 52 is shown provided in the end of the passage 50 distal from hot stab 44 , and proximity sensor 54 is illustrated in plug 28 . In the example of FIG. 1 , the plug 28 is adjacent the lower terminal end of passage 50 so that proximity sensors 52 , 54 are disposed facing one another. In this position, the position of the plug 28 can be sensed by interaction of the proximity sensors 52 , 54 that in turn creates a signal through the signal line 48 . It is within the capabilities of those skilled in the art to implement proximity sensors that sense the presence of one another.
[0020] A cable 56 is shown mounted on the closed end 15 , that in one example of operation provides for deploying the wellhead plug tooling package 10 from above the sea surface, such as from a vessel or platform (not shown). Further, the ROV 45 can be used to provide guidance support when deploying the wellhead plug tooling package 10 on the cable 56 . In this example, actuator arms 60 on the ROV 45 may grapple the wellhead plug tooling package 10 during deployment. Also, the ROV 45 can be controlled from surface by an attached control line 62 .
[0021] Referring now to FIG. 2 , an example of the wellhead plug tooling package 10 is shown landed on an upper end of a wellhead assembly 64 that is subsea. The wellhead assembly 64 is mounted into a subsea formation 66 , which is intersected by a wellbore 67 that is in fluid communication with the wellhead assembly 64 . A production tree 68 is included on an upper end of the wellhead assembly 64 and shown mounted onto a wellhead housing 70 ; where a lower end of the wellhead housing 70 anchors in the formation 66 . A main bore 72 in the wellhead assembly 64 (and tree 68 ) registers with the wellbore 67 to provide communication between the wellbore 67 and wellhead assembly 64 . Valves 73 are illustrated in the main bore 72 for controlling flow through the main bore 72 . A tubing hanger 74 is shown landed within the wellhead housing 70 ; a length of tubing 76 depends downward from the tubing hanger 74 and into the wellbore 67 . Shown landed in a portion of the wellhead housing 70 beneath the tubing hanger 74 , is a casing hanger 78 that circumscribes the tubing 76 . A length of casing 80 depends downward from the casing hanger 78 into the wellbore 67 , which also circumscribes the tubing 76 . Shown extending radially outward from the main bore 72 and through the production tree 68 are a production line 82 and auxiliary line 84 .
[0022] Referring now to FIG. 3 , the plug tooling assembly 20 is shown having been deployed downward from the housing 12 and into the main bore 72 . In one example, deploying the plug tooling assembly 20 is accomplished by activating a motor (not shown) within the tractor 22 that in turn drives the wheels 24 . Contacting the rotating wheels 24 against the walls of the chamber 82 and main bore 72 downwardly urge the plug tooling assembly 20 into the wellhead assembly 64 . Further, in the example of FIG. 3 , valves 73 are actuated to an open position thereby allowing passage there through of the plug tooling assembly 20 . Further in the example of FIG. 3 , the plug 28 is shown set within the tubing hanger 74 and in a position for plugging the wellhead assembly 64 . Setting the plug 28 in the tubing hanger 74 as shown defines a flow barrier within the main bore 72 . Further illustrated is how proximity sensors 52 , 54 are axially spaced apart from one another, so that by monitoring signals from proximity sensor 52 as described above, it can be confirmed that the plug 28 has deployed from within the housing 12 .
[0023] Further illustrated in the example of FIG. 3 , that that arm 60 of the ROV 45 is engaging hot stab 42 thereby creating communication from the ROV 45 into the plug tooling assembly 20 . Communication between ROV 45 and plug tooling assembly 20 is via a connection between a receptacle (not shown) in hot stab 42 and plug (not shown) in arm 60 , and communication through control cable 30 . Examples of operation exist wherein the plug tooling assembly 20 is gravity deployed from the housing 12 and into the wellhead assembly 64 instead of, or in addition to, activation of the wheels 24 on tractor 22 .
[0024] FIG. 4 illustrates in a side partial side sectional view that tractor 22 and end effector 26 have been retracted within housing 12 leaving plug 28 within tubing hanger 74 . In the example of FIG. 4 , latches 86 are shown extended radially outward and within a profile 88 provided on an inner surface of the tubing hanger 74 . In one example, the latches 86 are deployed via mechanical operation of the end effector 26 . An example of an end effector 22 suitable for use herein can be found in U.S. Pat. No. 7,121,344 issued Oct. 17, 2006, and assigned to the assignee of the present application. U.S. Pat. No. 7,121,344 is incorporated by reference herein in its entirety for all purposes. In another example, the plug 28 of FIG. 4 can be retrieved from within tubing hanger 74 by reversing the above described process, that is landing the housing 12 with enclosed tractor 22 and end effector 26 , deploying the tractor 22 , and end effector 26 into tubing hanger 74 , retracting the latches 86 from within the grooves 88 , and coupling the end effector 26 with plug 28 . Once attached to the end effector 26 , the plug can be removed from within tubing hanger 74 by drawing the tractor 22 and end effector 26 back into the housing 22 . The position of the plug within the housing 12 may be confirmed when proximity sensor 52 , 54 are appropriately positioned thereby providing a signal through signal line 48 , which may optionally be monitored by ROV 45 via its optional connection to hot stab 44 ( FIG. 1 ). In one example, after confirming the plug 28 is within housing 12 , the housing 12 can be detached from the wellhead assembly 64 and removed therefrom so that production from the wellbore 67 can be initiated.
[0025] Advantages of the system and method described herein include retrieving a plug from a tubing hanger without the need for a riser extending to the surface. Because a riser is unnecessary, a production tree can be efficiently removed on a lift wire (not shown). An example of this is provided in U.S. Pat. No. 6,968,902 issued Nov. 29, 2005, and assigned to the assignee of the present application. U.S. Pat. No. 6,968,902 is incorporated by reference herein in its entirety for all purposes. Moreover, because installing and/or removing the plug can be accomplished by use of an ROV 45 , an umbilical to the surface for the plug tool is unnecessary.
[0026] The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. For example, the tool may be additionally used to install/retrieve at least another plug set below the tubing hanger at a lower depth within the production tubing system. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims. | A system for maneuvering a plug in and out of a tubing hanger mounts to a subsea wellhead assembly. The system includes a tractor and an end effector that are sheltered in a housing. A control cable spools from a reel mounted on the housing and attaches to the tractor. The control cable provides communication from a remotely operated vehicle (ROV) to the tractor and end effector so that commands from the ROV via the control cable control the tractor and end effector. After the housing connects to the wellhead assembly, control signals from the ROV activate the tractor to drive the end effector into the wellhead assembly and command the end effector to set the plug in the tubing hanger, or to remove the plug from the tubing hanger. | 4 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a process for making a wet-layed metal fiber nonwoven sheet which also contains metal powder. In particular, the present invention relates to a process for making a metal fiber/metal powder sheet.
[0002] Papers comprised primarily of metal fibers have been desired by the industry for many years. Various methods have been developed for the preparation of metal fiber sheets. The manufacture of metal fiber nonwoven fabric-like paper structures on papermaking equipment has also been actively pursued due to its commercial attractiveness. Interest in such techniques is described, for example, in the chapter on metal fibers by Hanns F. Arledter in Synthetic Fibers in Papermaking, Editor O. Balestra, chapter 6, pages 118-184.
[0003] The problem in making metal fiber sheets using conventional papermaking techniques is that the metal fibers tend to clump together. Before paper can be made, it is necessary to open fiber bundles to achieve individual fibers and to disperse the fibers uniformly in a fluid. With most wood pulps, the opening is not usually a difficult task. The pulp or source of fibers is placed in water and the mixture is sheared until the bundles open.
[0004] With metal fibers, however, both the opening of the bundles and the dispersion of the fibers in order to keep the fibers separated are difficult. Normal types of mixing or shearing devices can easily damage metal fibers. When metal fibers are bent, they will remain bent and eventually will interact to form balls of tangled fibers. Paper made from fibers in this form is unacceptable.
[0005] It would be of great advantage to the industry, therefore, if a process for making a metal fiber sheet using conventional papermaking techniques, i.e., a wet-laying technique, can be used. Such a process should offer efficiency and commercial viability in terms of cost.
[0006] Moreover, the cost of a metal fiber sheet can be prohibitive. A metal sheet which is made of metal fiber but is more cost effective would also be attractive. A sheet containing metal fiber and metal powder would be such a sheet.
[0007] Accordingly, it is an object of the present invention to provide a metal fiber sheet which also contains a metal powder.
[0008] Yet another object of the present invention is to provide a process for making such a metal fiber/metal powder sheet using a wet laying technique.
[0009] These and other objects of the present invention will become apparent upon a review of the following specification, the figure of the drawing, and the claims appended hereto.
SUMMARY OF THE INVENTION
[0010] In accordance with the foregoing objectives, provided by the present invention is a wet-layed, nonwoven sheet which is comprised of metal fiber and metal powder. Generally, the amount of metal fiber comprises from 20 to 95% by weight and the amount of metal powder comprises from 5 to 80% by weight of the sheet. Such a wet-layed nonwoven sheet is economically preferable to a sheet comprised totally of metal fiber, since the metal powder is much less expensive. Among other factors, the present invention is based upon the recognition, using various process techniques, that the combination of metal fiber and metal powder can be wet-layed to obtain a structure of sufficient strength for subsequent handling and sintering.
[0011] In a preferred embodiment, the wet-layed nonwoven sheet comprised of metal fiber and metal powder is made by a process which involves first dispersing metal fibers and the metal powder into an aqueous dispensing fluid which contains a non-carboxy containing water soluble polymer. The aqueous dispensing fluid is then applied onto a screen, with the aqueous dispensing fluid then being removed to thereby form the metal fiber/metal powder sheet.
[0012] In another preferred embodiment, the wet-layed, nonwoven metal fiber/metal powder sheet of the present invention is made by a process which comprises first dispersing a mixture of the metal fiber, metal powder, wood pulp and a fibrillated material into an aqueous dispensing fluid. Generally, the amount of metal fiber and metal powder together ranges from 60 to 80 weight percent based upon the solids, the amount of wood pulp ranges from about 15 to about 30 weight percent, and the amount of fibrillated material ranges from about 5 to 15 weight percent based upon the weight of solids. The aqueous dispensing fluid is then applied onto a screen, and the fluid is removed to provide a metal fiber/metal powder sheet.
BRIEF DESCRIPTION OF THE FIGURE OF THE DRAWING
[0013] The FIGURE of the Drawing schematically depicts the process of the present invention useful in making a metal fiber/metal sheet by a wet-laying technique.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] In one preferred embodiment, the process of the present invention employs a non-carboxy containing water soluble polymer to aid in dispersing metal fibers into an aqueous dispensing fluid. The dry metal fibers, together with the metal powder, are added to an aqueous dispensing fluid, to which the non-carboxy containing water soluble polymer is also added. Through mixing, the metal fibers and metal powder are dispersed in the presence of the non-carboxy containing water soluble S polymer.
[0015] Among the water soluble polymers useful for the present invention are polyvinyl alcohol, starch or cellulose ethers. Generally, the water soluble polymer comprises from 1 to 5 weight percent of the aqueous dispensing fluid. In a preferred embodiment, starch is the water soluble polymer used as the dispersing aid, and is generally used in an amount ranging from 3 to 4 weight percent based upon the weight of aqueous dispensing fluid.
[0016] The water soluble polymer can be added directly to the aqueous dispensing fluid, generally before the metal fiber is added. This will allow the water soluble polymer to immediately begin to interact with the dry fiber. While the water soluble polymer allows the dry fiber to disperse, it also aids in the formation of the metal fiber web by maintaining separation of the metal fibers. The fact that such a small amount of a water soluble polymer such as starch can be used to effectively maintain separation is quite surprising.
[0017] In another preferred embodiment, the process of the present invention employs a combination of wood fibers and fibrillated material to aid in dispersing metal fibers into an aqueous dispensing fluid. The dry metal fibers are added together with the wood fibers and fibrillated material to the aqueous dispensing fluid. Through mixing, the metal fibers, wood fibers and fibrillated material are dispersed.
[0018] More specifically, the wood fibers can be any conventional wood fiber, such as softwood or hardwood fibers. Mixtures of wood fiber, including mixtures of softwood and hardwood fibers, can be used. Softwood fibers, however, are preferred. The amount of wood pulp fibers used generally ranges from about 15 to 30 weight percent.
[0019] Together with the wood pulp, a fibrillated material is used. Fibrillated materials are known in the industry, and are generally referred to as fibrids. The materials are high surface area materials of a surface area in the range of from about 5-20 m 2 /g. This is in contrast to wood pulp, which generally has a surface area in the range of from about ½-2 m 2 /g. The fibrillated material can be made by any conventional method, with the use of organic materials being most preferred.
[0020] It has been found that a combination of the wood pulp with the fibrillated material provide for an excellent metal fiber dispersion and the making of an excellent metal fiber sheet. Cellulon and Kevlar fibrids, both available commercially, are the most preferred fibrillated materials for use in the present invention. Another suitable material is a cellulose acetate fibrid commercially available under the mark FIBRET, available from Hoechst/Celanese Co. The amount of fibrillated material used generally ranges from 5 to 15 weight percent.
[0021] The presence of the fibrillated material has been found to be very important with regard to the present invention. It is important to generate an aqueous slurry comprised of the wood pulp and the fibrillated material. The slurry is preferably generated generally by the use of a high shear and a high energy agitator. Such agitators are well known. Colloid mills, such as the ones available from Silverson, have been found suitable.
[0022] The metal fibers are dispersed in the aqueous slurry of the high surface area material by using a non-stapling mixer, as is well understood in the industry. In general, such a mixture would have a leading surface larger in width, height and/or diameter than the length of the metal fibers. It is important to provide sufficient shear to break up the metal fiber bundles but it is equally critical to avoid bending the fibers and creating fiber aggregates. If the metal fiber aggregates are allowed to form by the application of too much mixing energy it is very difficult to re-disperse them.
[0023] Although it is possible to disperse the metal fibers in a slurry composed only of water and a high surface area material like bacterial cellulose, there are advantages to incorporating wood pulp in this slurry. We have observed that the presence of wood pulp improves the paper making characteristics like uniformity of the dispersion, the wet web strength, and the dry strength.
[0024] The metal fibers can be any useful metal fiber, with nickel and stainless steel fibers being most preferred. The stainless steel fibers can, for example, be stainless steel 304 fibers, stainless steel 316 fibers or stainless steel Hastelloy X fibers. Nickel and stainless steel fibers are most preferred because their potential uses are exceptional. The metal powder used can be of the same or different metal than that of the metal fibers, and can be made by any conventional method. It is preferred that nickel powder is used, particularly when nickel fiber is used. Suitable nickel powders are available commercially, for example, from INCO Specialty Powder Products of Wyckoff, N.J. Such suitable powders include, for example, the INCO extra-fine Nickel Powder TYPE 210, which is a submicron size filamentary powder. It is produced by the thermal decomposition of nickel carbonyl and is virtually free of other metallic impurities. Other suitable nickel powders, and other metal powders, are also available from INCO.
[0025] Conventional additives can also be added to the aqueous dispensing fluid. Such additives would include, for example, a biocide to inhibit microorganism growth in dispensing fluid. Other conventional additives can also be added.
[0026] Once the metal fibers have been dispersed in the aqueous dispensing fluid, the dispensing fluid is then applied to a screen as is conventional in papermaking process. The aqueous dispensing fluid is then removed in order to form the metal fiber sheet. Generally this is done through vacuum suction of the fluid through the screen. In a preferred embodiment, the process of the present invention is conducted in a closed system where the dispensing fluid removed from the metal fibers is recycled and reused.
[0027] Turning now to the FIGURE of the Drawing, a mixing vessel 1 contains the aqueous dispensing fluid together with the non-carboxy containing water soluble polymer such as starch. The dry metal fiber is added via 2 into the dispensing fluid. Mixing is achieved by a stirrer 3 . Generally, the mixer 3 is an agitator that does not induce fiber stapling, as is known in the art. The mixing continues until the desired fiber separation is achieved.
[0028] In a preferred embodiment, the aqueous dispensing fluid containing the dispersed metal fibers is passed to a second mixing tank 4 . The additional mixing is optional, but does insure good formation in the subsequent sheet. It is therefore preferred that a plurality of such mixing tanks be employed to insure good dispersion and formation of the metal sheet.
[0029] The aqueous dispensing fluid is then passed to a headbox 5 , through which the aqueous dispensing fluid containing the metal fibers is applied to a continuous screen 6 . A vacuum system 7 is generally used to remove the aqueous dispensing fluid in order to form the metal fiber sheet on the screen. In a preferred embodiment, the removed aqueous dispensing fluid is then recycled to the mixing tank 1 via line 8 . Generally, about 60 weight percent of the metal powder is retained in the metal fiber sheet using the non-carboxy water soluble polymer.
[0030] The formed metal fiber sheet is then passed through press rolls, can then be calendared and dried as is conventional in the papermaking industry. Despite the use of such a small amount of water soluble polymer, the residue is sufficient to provide sufficient strength to the metal fiber sheet so that such subsequent handling can occur without incident.
[0031] The final step is a sintering step which-can be conducted at optimum temperatures in an inert or reducing atmosphere. The sintering step introduces a strength to the metal fiber paper, as well as burns off the various organics contained in the metal fiber paper. The sintering step generally involves heating the paper at a temperature of from 1500-1200° F. for a time necessary to burn off the organics. The sintering step is preferably conducted in a hydrogen atmosphere. If desired, a prior pyrolysis step can be conducted at a lower temperature to initially burn off organics. However, the pyrolysis step does not impart the necessary strength to the paper, and should be followed by the sintering step at the higher temperature of from 1500-2000° F. to burn off any remaining organics and to provide the desired strength to the paper. The resulting fiber paper contains at least about 99 weight percent metal.
[0032] Turning now to the FIGURE of the Drawing, a mixing vessel 1 contains the aqueous dispensing fluid together with any desired additives. The dry metal fiber is added via 2 into the dispensing fluid, together with the wood pulp and fibrillated material in the desired amounts. Mixing is achieved by a stirrer 3 . Generally, the mixer 3 is an agitator that does not induce fiber stapling, as is known in the art. The mixing continues until the desired fiber separation is achieved.
[0033] In a preferred embodiment, the aqueous dispensing fluid containing the dispersed metal fibers is passed to a second mixing tank 4 . The additional mixing is optional, but does insure good formation in the subsequent sheet. It is therefore preferred that a plurality of such mixing tanks be employed to insure good dispersion and formation of the metal sheet.
[0034] The aqueous dispensing fluid is then passed to a headbox 5 , through which the aqueous dispensing fluid containing the metal fibers is applied to a continuous screen 6 . A vacuum system 7 is generally used to remove the aqueous dispensing fluid in order to form the metal fiber sheet on the screen. In a preferred embodiment, the removed aqueous dispensing fluid is then recycled to the mixing tank 1 via line 8 .
[0035] The formed metal fiber sheet is then passed through press rolls, and can then be calendared and dried as is conventional in the papermaking industry. The metal fiber sheet has sufficient strength to permit subsequent handling to occur without incident.
[0036] The final step is a sintering step which can be conducted at optimum temperatures in an inert or reducing atmosphere. The sintering step introduces a strength to the metal fiber paper, as well as burns off the various organics, i.e., the wood pulp and the fibrillated material, contained in the metal fiber paper. The resulting fiber paper contains at least about 95 weight percent metal, and most preferably about 99 weight percent.
[0037] The resulting metal fiber sheet is useful in many different applications. For example, the metal fiber sheet can be used as a battery electrode. Nickel fiber is preferred for such an application. The metal fiber sheets can also be used as fluid filters. The filters can be useful for hydraulic fluids, water or oil. The metal fiber sheets can also be used as gas filters, for example in the filtering of air or exhaust gases. The applications are many, and with the use of the present invention in the preparation of metal fiber sheets, the availability of such sheets in an economic fashion will be increased.
[0038] The invention will be illustrated in greater detail by the following specific examples. It is understood that these examples are given by way of illustration and are not meant to limit the disclosure or the claims to follow. All percentages in the examples, and elsewhere in the specification, are by weight unless otherwise specified.
EXAMPLE 1
[0039] 8 oz/sq yd metal handsheets were made. The handsheets contained 10%. Ni fiber and 50% Ni powder. The basis weight of the 8 oz/sq yd handsheets was equal to 166.6 lb/3000 sq. ft. Total basis weight was (166.6/0.60) or 278 lb/3000 sq ft. This is equal to 57 grams per 14×14 handsheet.
[0040] The following materials were used in making the handsheets:
10% Ni fiber 0.25 inch × 8 micron 5.72 g Oven Dry 50% Ni powder (Int Nickel Grade 225) 28.6 g Oven Dry 20% Kevlar pulp 11.4 g OD or 62.2 at 18.4% solids 20% Northern Hardwood pulp 11.4 g OD or 12 g at 95% solids
[0041] The general procedure followed was:
[0042] Blend Kevlar pulp in 1 liter water in a Waring blender for 3 min at high. Blend the N. Hardwood pulp in 1 liter of water in a Waring blender for 3 min at high. All ingredients were mixed in a 5 gal baffled pot with 8 inch foil blade at 590 RPM for 5 min. No surfactants or binders were added. The handsheet was formed with no pressing. About 80% retention of Ni powder was observed. The sheet contained about 7.75 oz of Ni (powder and fiber) per sq yd.
[0043] A paper where all of the nickel was in powder form was also attempted. The paper would not hold up during sintering if the metal fiber was missing from the recipe. In this experiment, the nickel fiber improved the strength of the paper during the sintering process.
EXAMPLE 2
[0044] A 6 oz/sq yd or 125 lb/ream or 25.73 g/14×14 handsheet was made. It was decided to actually use 28.6 g per handsheet to allow for powder loss. The following materials were used:
Material Percent, OD Mass, g (OD) Mass, g (As Is) Ni Powder 50 14.3 14.3 Ni Fiber 11 3.15 3.15 (8 micron,) .25 inch No. Softwood pulp 16 4.58 4.90 No. Hardwood pulp 16 4.58 4.90 Cellulon 7 2 10.5
[0045] All ingredients were added to a 5 gal baffled pot with 4 liters of water. Mixing occurred for 3 min at 540 RPM with a ¾ inch×9 inch foil agitator. 4 ml of a 1% cationic coagulation aid (Nalco 7520) was added to assist in the retention of the powder. Handsheet was formed with no further dilution, which was pressed with roll weight only. Three handsheets were made, which had an oven dry mass of 28.7, 28.8, and 28.9 grams, respectively.
EXAMPLE 3
[0046] National Starch's branched starch (amylopectin) known by the trade name Amioca, was used to make a solution about 3% in strength which had a viscosity of 30 centipoise. Four liters of this solution was added to a baffled 5 gallon pot. To this was added the ingredients listed below.
Metal fiber, Nickel powder, 4 micron by INCO 255 4 mm long (2.2-3.3 micron) Handsheet 1 4.13 grams 4.13 grams Handsheet 2 4.13 grams 41.30 grams
[0047] The mixture was stirred with a nine inch foil blade at 1280 RPM for 45 seconds. A single drop of DOW A defoamers was added. The resulting fiber-powder mixture was poured into an eight inch by eight inch handsheet mold with no further dilution. Handsheet 1 was dried and weighed. The sheet retained about 5% starch, so the dry sheet contained about 9% powder, 5% starch, and about 86% metal fibers. Of the metal powder added, about 11% was retained.
[0048] Sheet 2 was also dried and weighed. It contained about 5% starch, thus the powder content was 70% and the metal fiber content was 25%. Of the powder added, about 25% was retained.
[0049] No retention aids like cationic polymers or alum solution were added to either handsheet.
[0050] While the invention has been described with preferred embodiments, it is to be understood that variations and modifications may be resorted to as will be apparent to those skilled in the art. Such variations and modifications are to be considered within the purview and the scope of the claims appended hereto. | Provided by the present invention is a wet-layed, nonwoven sheet which is comprised of metal fiber and metal powder. Generally, the amount of metal fiber comprises from 20 to 95% by weight and the amount of metal comprises from 5 to 80% by weight of the sheet. Such a wet-layed nonwoven sheet is economically preferable to a sheet comprised totally of metal fiber, since the metal powder is much less expensive. Among other factors, the present invention is based upon the recognition that by using various process techniques, the combination of metal fiber and metal powder can be wet-layed to obtain a structure of sufficient strength for subsequent handling and sintering. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the U.S. national stage application of International Patent Application No. PCT/US2009/048467, filed Jun. 24, 2009, which claims the benefit of U.S. Provisional Application Ser. No. 61/075,258, filed Jun. 24, 2008, which is hereby incorporated by reference herein in its entirety, including any figures, tables, or drawings.
GOVERNMENT SUPPORT
The subject matter of this application has been supported by a research grant from the National Science Foundation under grant number EEC-9402989. Accordingly, the government has certain rights in this invention.
BACKGROUND OF THE INVENTION
Fullerenes are well known as omnidirectional electron acceptors. Due to the spherical and symmetrical nature of the more common fullerenes, such as C 60 known as Buckminster fullerene, electrons can be accepted at any point on the fullerene cage, which differs from typical organic electron scavengers that accept electrons only at specific sites of the scavenger molecule. This non-specific electron accepting ability of fullerenes has been exploited for various applications including electrochemical sensors, photochemical cells, therapeutics, photocatalysis, and electronic devices such as n-type and field effect transistors.
Pristine and functionalized fullerenes have been employed as electron acceptors in electrochemical sensors for detection of various organo- or bio-analytes such as dopamine and nandrolone. Typically, the electrochemical sensor comprises an electrode upon which fullerenes have been coated. The sensing results due to the transfer of electrons to the fullerene by a negatively charged analyte upon application of an electric field.
For photochemical and solar cells, typically fullerenes are employed as metal porphyrin-fullerene combinations or in other forms such as dyads. For a metal porphyrin-fullerene combination the metal porphyrin generates electrons upon absorption of photons. The electrons are then scavenged by the conjugated fullerenes to promote the flow of current through a circuit. In addition to metal porphyrins, other photoactive materials that can be combined with fullerenes for use in photochemical cells include TiO 2 , ZnO and various organic dyes.
Fullerenes scavenge free radicals, such as superoxide, by accepting electrons from the free radical. These antioxidant properties of fullerenes have been applied for therapeutic uses, such as the treatment of various diseases such as Alzheimer and Parkinson disease and for reducing the side-effects of cancer treatment. Fullerene comprising compositions have been commercialized as anti-ageing cosmetics.
Fullerenes have been used in combination with semiconductor photocatalysts. Semiconductor photocatalysts are employed for the destruction of environmentally hazardous chemicals and bioparticulates, as these materials can be a cost-effective means to achieve complete mineralization of these environmental hazards without generation of toxic byproducts. For example, titanium dioxide has been commercially applied as a self-cleaning coating on buildings and glass materials. However, such applications have been limited by the low quantum efficiency of these photocatalysts. In photocatalysis, with a photocatalyst such as titanium dioxide, electron-hole pairs are generated in the semiconductor upon irradiation with ultraviolet light. Some of the photo-generated electrons and holes migrate to surfaces, where they undergo redox reactions to generate reactive species such as hydroxyl radicals. However, the photo-generated electrons and holes can also undergo recombination, which reduces the quantum efficiency of photocatalysis.
Several attempts have been made to separate the photogenerated electrons and holes to reduce recombination. Titanium dioxide photocatalysts have been conjugated or doped with electron scavenging agents such as metals or organic molecules. Numerous organic molecules have been conjugated with titanium dioxide for applications that include solar cells and visible light photocatalysis. Platinum, gold and silver metals are often employed as scavenging agents, generally due to their high conductivity, although conflicting results have been reported. Another class of conductors examined is carbon nanotubes. For example, anatase coated multi-wall carbon nanotubes (MWNT) achieved twice the efficacy of a commercial photocatalytic TiO 2 (Degussa P25) for inactivation of bacterial endospores. It was hypothesized that the photo-generated electrons are scavenged by the MWNT. These approaches involve processing to conjugate or dope the TiO 2 or scavenging agent and have resulted in a relatively high cost to produce the modified photocatalysts.
As indicated above, fullerenes such as C 60 , because of their unique electronic properties, have been examined for combination with semiconductor photocatalysts. Kamat et al., “Photochemistry on Semiconductor Surfaces. Visible Light Induced Oxidation of C 60 on TiO 2 Nanoparticles”, J. Phys. Chem. B, 1997, 101 (22) 4422-7, discloses the transfer of photo-generated electrons from titanium dioxide to fullerenes with ethanol/benzene mixed solvent. Fullerenes are extremely hydrophobic, limiting their use for enhancing photocatalysis in aqueous environments. The water solubility of fullerenes improves by forming hydroxyl groups on the surface of the fullerenes. However, addition of hydroxyl groups to the fullerene structure modifies the electronic properties of the fullerenes. The toxic effects attributed to fullerenes are not observed for the hydroxylated form of fullerenes. Rather, polyhydroxyfullerenes are able to reduce oxidative stress on cells by scavenging reactive oxygen species and have been patented as therapeutics as, for example: Chiang et al., U.S. Pat. No. 5,994,410.
Recently Polyhydroxyfullerenes (PHFs) were reported for enhancement of the photocatalytic activity of titanium dioxide (TiO 2 ). Krishna et al., “Enhancement of Titanium Dioxide Photocatalysis with Water-Soluble Fullerenes”, J. Colloid and Interface Sci., 2006, 304, 166-71, demonstrated that hydroxylated fullerenes display electron accepting properties and can be employed to scavenge photogenerated electrons from TiO 2 , thereby increasing the rate of photocatalysis. However, not all PHFs enhance the photocatalytic activity of TiO 2 . Hence, identification of the PHF structures that promote TiO 2 photocatalytic activity is needed.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to polyhydroxyfullerenes (C 20 to C 500 PHFs) having an average ratio of non-hydroxyl functional groups to hydroxyl functional groups that is less than or equal to 0.3. PHFs in which this ratio is higher provide significantly less efficiency and can impair the performance of materials that require electron scavenging.
A photocatalyst comprising TiO 2 nanoparticles and PHFs can be used for degradation of chemical or bacteriological contaminants. The photocatalyst can be a suspension in an aqueous solvent and is readily formulated as an aqueous suspension. The catalyst can be prepared from commercially available TiO 2 nanoparticles with a diameter of about 2 to about 100 nm in diameter. Incorporating the PHFs at very low levels, 0.001 to 0.003 grams of PHFs per g of TiO 2 , forms an effective photocatalyst.
Additionally, the invention is directed to a method of photochemically decontaminating a surface or a fluid medium in contact with the surface. The fluid medium can be a liquid or a gas, where the contaminants are either dissolved or suspended in the medium. The surface is rendered photochemically active by providing a photocatalyst as described above to the surface. Irradiating the photocatalyst with ultraviolet or visible light promotes the degradation of the contaminant. Irradiation can be the exposure of the photocatalyst to a light source. The light source can be natural light such as sunlight, or can be provided by an artificial lamp. For example UVA irradiation can be provided from an ultraviolet lamp.
In an embodiment of the invention, the novel PHFs can be employed as an active film for a heterojunction organic solar cell when combined with a conjugated polymer. Such polymers include polythiophene, substituted polythiophene, polyvinylenephenylene substituted polyvinylenephenylene, polybenzothiadiazole, substituted polybenzothiadiazole, polypyrroles, substituted polypyrroles or copolymers thereof. In another embodiment of the invention, the enhanced electron scavenging PHFs can be used as the organic semiconductor for an organic thin-film field effect transistor (FET) where, when PHFs are used alone, is an n-channel semiconductor. Alternately, the PHFs can be combined with a conducting polymer that is a p-channel semiconductor to create an ambipolar device. In another embodiment, the PHFs can be used as a radical scavenger, functioning as an antioxidant or radioprotectant.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows atmospheric pressure chemical ionization mass spectra (APCI-MS) of PERC PHFs (enhancing) and BuckyUSA PHFs (inhibiting).
FIG. 2 shows Fourier Transform. Infrared Spectra of PERC PHFs (enhancing) and BuckyUSA PHFs (inhibiting).
FIG. 3 shows the structure of a C 60 (OH) 24 molecule calculated by Gaussian simulation.
FIG. 4 shows a vibrational spectrum for C 60 (OH) 24 calculated by Gaussian simulation.
FIG. 5 shows the C1s signals in XPS spectra of PERC PHFs (enhancing) and BuckyUSA PHFs (inhibiting). Each spectrum is deconvoluted into three signals for non-oxygenated, mono-oxygenated and di-oxygenated carbons.
FIG. 6 shows thermal gravimetric analysis (TGA) spectra of PERC PHFs (enhancing) and BuckyUSA PHFs (inhibiting).
FIG. 7 shows first-order degradation kinetics plots for Procion Red MX-5B under UVA irradiation using TiO 2 , TiO 2 with BuckyUSA PHFs (enhancing), and TiO 2 with PERC PHF (inhibiting) as photocatalysts. Error bars represent plus or minus 1 standard deviation.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to PHF compositions that result in an enhanced electron scavenging ability. In embodiments of the invention the enhanced electron scavenging PHFs are combined with other materials or employed in devices that exploit the enhanced electron scavenging PHFs. The functionality of PHF influences its electron scavenging ability. PHFs commonly contain functional groups such as hydroxyl, hemiketal, epoxide and carbonyl groups that modify the electronic properties of the PHFs. It was discovered that PHFs which have a low ratio (< or =0.3) of non-hydroxyl functional groups to hydroxyl functional groups have enhanced electron scavenging ability, whereas PHFs that display a ratio higher than 0.3 have little or no electron scavenging ability. It was also discovered that PHFs where the weight loss to temperatures of about 1,000° C. is less than about 55% exhibit enhanced electron scavenging ability, whereas PHFs which display weight loss of more than 80% have little or no electron scavenging ability and can even promote inhibition of processes requiring an electron scavenger. PHF compositions that achieve higher electron scavenging can enhance processes such as photocatalysis.
PHFs can be of a single size or can be mixtures of different fullerene sizes. The fullerene cage can be C 28 , C 32 , C 44 , C 50 , C 58 , C 60 , C 70 , C 84 , C 94 , C 250 , C 540 , or any other fullerene. The PHFs have an average of about 1.25 to 3 C atoms per OH group, which is equivalent to about 27 to about 48 OH groups on a C 60 cage. The PHFs are often C 60 molecules due to their commercial availability, but C 70 , C 82 or their mixtures or other PHFs can be used in various embodiments of the invention. The PHFs have C—C single bonds that can be observed by Fourier transform infrared spectroscopy (FTIR). Other functional groups are primarily carbons of a hemiketal and carbonyl structure. PHFs can also contain epoxy groups and ester groups. As the PHFs of the present invention are water soluble, they can be incorporated into devices that can exploit their enhanced electron scavenging capabilities and permit fabrication or use in an aqueous environment. Hence, the enhanced electron scavenging PHFs can be used in biological systems or permit processing from aqueous solution for electronic devices.
In an embodiment of the invention, a photocatalytic composition of scavenging enhanced PHFs with semiconducting photocatalyst nanoparticles comprises a ratio of PHF/photocatalyst of about 0.001 to about 0.003 in aqueous suspension at about pH 6. In an embodiment employing TiO 2 as the photocatalyst, the photocatalytic activity of the inventive composition is at least two times the photocatalytic activity of TiO 2 , absent the PHFs. The TiO 2 concentrations can be from about 10 to about 100 mg/L. The TiO 2 nanoparticles can range from about 2 to about 100 nm in diameter. The PHFs have C—C single bonds that are observable by Fourier transform infrared spectroscopy (FTIR). Other functional groups are primarily carbons of a hemiketal and carbonyl structure. PHFs can also contain epoxy groups and ester groups as long as the ratio of non-hydroxyl functional groups to hydroxyl functional groups is 0.3 or less.
Among the semiconducting photocatalysts that can be used for the practice of the invention are particles of titanium oxide, anatase titanium oxide, brookite titanium oxide, strontium titanate, tin oxide, zinc oxide, iron oxide, and mixtures thereof. Particles can range from about 2 to 500 nm maximum cross section or diameter. Particles can range from 2 to 100 nm in average diameter or cross section. The particles can be spherical or any other shape. Another embodiment of the invention including semiconducting photocatalysts with PHFs is a method to decontaminate a surface or a fluid in contact with the surface. The surface is treated with semiconducting photocatalytic nanoparticles with the proper proportions of scavenging enhancing PHFs or other functional fullerenes. The fluid in contact with the photocatalyst can be a liquid, generally an aqueous solution, or a gas. Irradiation of the photocatalyst results in the decomposition of chemical or biological contaminates. The irradiation source can be ultraviolet (UV) or visible and can be from a natural or artificial source. For example, sunlight can be used for the irradiation of the photocatalyst or light from a lamp can be directed to the photocatalyst. The system can be employed on exterior surfaces for passive cleaning in air ventilation systems or in water purification systems where the photocatalyst is restricted to a desired region to function as a decontaminating agent. The fluids can be forced into contact with the photocatalyst and recirculated to promote partial to complete decontamination of the fluid.
In other embodiments of the invention the electron scavenging enhanced PHFs as an electron acceptor are combined with an electron donor to form a heterojunction organic solar cell's active film. The electron donor can be a low band gap conjugated polymer, for example polythiophene, substituted polythiophene, polyvinylenephenylene substituted polyvinylenephenylene, polybenzothiadiazole, substituted polybenzothiadiazole, polypyrroles, substituted polypyrroles and regular or random copolymers thereof. The active film can also have included nanoparticulate semiconducting photocatalyst, such as TiO 2 . Conjugated polymers that are water soluble due to substitution can be combined with the water soluble PHFs to fabricate an active film of a heterojunction organic solar cell.
In other embodiments of the invention, the electron scavenging enhanced PHFs are used as the organic semiconductor of n-channel organic thin-film field effect transistors (FETs). In another embodiment of the invention, the electron scavenging enhanced PHFs can be combined with p-channel organic components, such as polythiophenes, to form ambipolar organic field effect transistors.
In another embodiment of the invention, the electron scavenging enhanced PHFs can be employed as a radical scavenger or antioxidant. The electron scavenging enhanced PHFs can be employed as a radioprotectant for an organism that experiences exposure to ionizing radiation, such as X-rays.
Materials and Methods
Two types of polyhydroxyfullerenes, both synthesized by an alkali route, were tested: 1) PHF from BuckyUSA (BuckyUSA PHF) and 2) PHF synthesized in the laboratory (PERC PHF). The laboratory synthesis was carried out in a manner derived from that disclosed in Li et al. J. Chem. Soc .- Chem. Commun., 1993, 1784. A solution of non-derivatized fullerenes was prepared by adding 80 mg of C 60 (95%, BuckyUSA, Houston Tex.) to 60 mL of benzene (HPLC grade, Fisher). A mixture of 2 mL of NaOH solution (1 g/mL) and 0.3 mL of tetra butyl ammonium hydroxide (40% solution) was prepared in a separate Erlenmeyer flask. The fullerene solution was added to the alkali-surfactant solution under vigorous stirring. The stirring was stopped after 30 minutes and the mixture was allowed to phase separate. The top clear phase was decanted and the remaining slurry was stirred with an additional 12 mL of deionized water for 24 hours. The mixture was filtered through Whatman 40 filter paper and the filtrate was concentrated to 5 mL in a vacuum oven at 60° C. The resultant slurry was washed four times with 50 mL of methanol by alternate centrifugation (5000 g, 10 min) followed by resuspension in methanol. After the final wash, PHF were suspended in 20 mL of methanol and dried under vacuum at 60° C. The mass of PHF obtained was 120 mg. The PHF samples were analyzed with atmospheric pressure chemical ionization (APCI) mass spectroscopy (MS) (ThermoFinnigan, San Jose, Calif.).
Both the BuckyUSA and PERC PHFs were characterized by Diffuse Reflectance Infrared Fourier Transform (DRIFT) and x-ray photoelectron spectroscopy (XPS). DRIFT experiments were carried out with Thermo Electron Magna 760 unit with potassium bromide as the background. XPS experiments were performed with Kratos Analytical Surface Analyzer XSAM 800 in survey and multiplex mode. The carbon 1s (C1s) spectrum was subjected to peak fitting analysis using Grams 7.01 software (Thermo Fisher Scientific, Waltham, Mass.) to determine the oxidation states of carbon.
Characterization of PHF Samples
Mass Spectroscopy
Mass spectroscopy was employed to investigate the stability of the fullerene cages of the BuckyUSA and PERC PHF samples. The portions of the MS spectra in the range of 700-850 m/z for the two samples are presented in FIG. 1 . In both samples, the base fullerene (C 60 ) peak at 720.6 m/z is present at a relative intensity of 100, indicating that the fullerene cage is intact.
FTIR Analysis
FTIR spectroscopy has been employed previously to identify functional groups present on a fullerene cage. The FTIR-DRIFT spectra for BuckyUSA and PERC PHF are presented in FIG. 2 . The PERC PHF exhibits five peaks at 3300, 1591, 1450, 1062, 881 and 471 wavenumbers along with shoulders at 1661, 1357 and 1165 wavenumbers. The BuckyUSA PHF has peaks at 3300, 1595, 1408 and 1074 wavenumbers with a shoulder at 1680 cm −1 . The vibrational modes of PHF were assigned to FTIR peaks of PHF based on the information obtained from a Gaussian simulation and the literature, as shown in Table 1, below. The peak at 1591 was not observed in the simulation and was ascribed to C═C vibrations as reported in the literature. The shoulders at 1658 cm −1 , 1357 cm −1 and 1165 cm −1 were attributed to hemiketal, epoxides and esters respectively.
TABLE 1
Assignments of FTIR peaks for PERC and BuckyUSA PHF
based on results from Gaussian simulation of C 60 (OH) 24
and literature.
Peak Assignments in
Peak Location in
cm −1 based on Gaussian
cm −1 based on
simulation and/or literature
Vibration
Gaussian
BuckyUSA
modes
Simulation
Literature
PERC PHF
PHF
O—H stretching
3450
3420, 3430,
3300
3300
3410, 3300
Hemiketal
—
1658
1661
1680
C═C stretching
—
1595, 1600,
1591
1595
1593, 1585
C—O—H
1450
1392, 1412
1450
1408
bending
Epoxides
—
1376
1357
—
C—O stretching
1070
1084, 1070,
1062
1074
1065
Esters
—
1197
1165
—
C—C
—
490
471
—
Semi-empirical computation (PM3) has been employed in the literature for structure optimization of various hydroxylated fullerenes and possible stable isomers are reported in the literature. However, no reports are present on theoretical prediction of vibrational peaks for hydroxylated fullerenes. Therefore, hybrid quantum chemical computations were carried out to identify the vibration modes responsible for experimentally observed FTIR peaks. For ease of simulation, 24 hydroxyl groups and no carbonyl, hemiketal and epoxide functionalities on the PHF were assumed. The structure optimization and vibration spectrum generation were performed with hybrid quantum-chemical basis set (B3LYP 6-31G*). The optimized structure, as shown in FIG. 3 , is similar to the reported C 60 (OH) 24 structure obtained by a semi-empirical quantum-chemical optimization (PM3), as reported in Slanina et al., Proceedings of the Electrochemical Society, 1996, 96, 987. The hydroxyl groups are present as intramolecularly hydrogen bonded islands on fullerene cage, similar to the results found in the literature. The average C—O and O—H bond lengths are 1.43 and 0.98 Å, respectively, and the average C—O—H bond angle is 107°. These results are similar to the values obtained with PM3 optimization for C 60 (OH) 26 by Guirado-Lopez et al., J. Chem. Phys., 2006, 125. Additionally, weak intramolecular hydrogen bonding was observed with an average bond length of 1.78 Å, which is similar to the hydrogen bond length in water.
The vibration spectrum generated for C 60 (OH) 24 with the B3LYP 6-31 G* basis set is presented in FIG. 4 , with wavenumbers increasing from left to right on x axis. The simulated FTIR peak exhibits four major peaks. The broad peak at 3450 cm −1 originates from O—H stretching. The peak at 1450 cm −1 , 1070 cm −1 and 370 cm −1 represents C—O—H bending, C—O stretching and O—H rocking vibrations, respectively.
Both samples of PHF have hemiketal and epoxide groups in addition to hydroxyl groups, as revealed by FTIR and XPS analysis. This is consistent with reports in the literature. Rodriguez-Zavala et al., J. Phys. Chem. A, 2006, 110, 9459, discloses theoretical studies on hydroxylated fullerenes with different numbers of epoxide groups, where the presence of epoxide groups on hydroxylated fullerenes can have significant effects on their structure and electronic and optical properties.
XPS Analysis
PHFs have hemiketal, epoxide and sometimes carbonyl functional groups in addition to hydroxyl groups. Therefore, extensive characterization of PHF as well as determination of its empirical formula is necessary to compare the properties. Unfortunately, there is a lack of consistency in literature on techniques employed for determining the empirical molecular formula of PHF. Three common methodologies employed are elemental analysis, thermo gravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). It is known that the presence of residue can influence the empirical formula determined by TGA and elemental analysis. Therefore XPS data was used to determine the empirical formulas for PERC and BuckyUSA PHF samples.
XPS analysis indicated the presence of C, O and Na in both PERC and BuckyUSA PHF samples. The relative atomic concentrations determined for each element are provided in Table 2, below. The C1s region was deconvoluted as three Gaussian curves revealing the presence of three oxidation states of carbon, as shown in FIG. 5 , which is in agreement with the literature. Since no carbonyl peak was present in FTIR spectra, the highest oxidation state was assumed to be due to hemiketal structure as revealed from FTIR. The curve fitting analysis of the three Gaussian peaks was performed for the C1s spectrum of PERC and BuckyUSA PHF to calculate the relative concentration of each carbon oxidation state (Table 3). The relative concentration of mono-oxygenated carbon is three times higher in PERC PHF than BuckyUSA PHF.
TABLE 2
Elemental Composition of PHFs by XPS
Relative Non-Hydrogen Atomic
Concentration in Percent
Element
PERC PHF
BuckyUSA PHF
Carbon
61.23
47.33
Oxygen
28.44
33.82
Sodium
10.33
18.85
TABLE 3
Peak Position and Elemental Composition of PHFs by
XPS Analysis
Oxidation
Peak Position in eV
State of
PERC
BuckyUSA
Relative Concentration in %
Carbon
PHF
PHF
PERC PHF
BuckyUSA PHF
Non-
284.8
284.8
40.2
57.1
oxygenated
Mono-
286.16
286.14
47.1
16.1
oxygenated
Di-
288.55
287.91
12.7
26.8
oxygenated
The relative atomic concentrations of C, O and Na and along with concentrations of mono- and di-oxygenated states of carbon were employed to deduce the composition of PHF using the assignment as per Husebo et al., J. Amer. Chem. Soc., 2004, 126, 12055. The molecular formula for PERC PHF was calculated as C 60 O 8 (OH) 28 Na 10 and for BuckyUSA PHF as C 60 O 16 (OH) 10 Na 24 . The empirical formulas are consistent with the number of functional groups added to fullerene cage as being in the range of 25 to 42; however, the PERC PHF displayed a higher number of functional groups per molecule than BuckyUSA PHF.
TGA Analysis
Thermo gravimetric analyses (TGA) of PERC and BuckyUSA PHF samples are presented in FIG. 6 . The weight loss generally occurs in 4 or 5 stages. The first stage of weight loss is attributed to desorption of physically adsorbed water and accounted for 16% of the weight of both PHF samples. The second stage is attributed to desorption of hydroxyl functional groups and was 20% and 21% of the weight of PERC and BuckyUSA PHF, respectively. The weight loss in stage 3 is attributed to desorption of hemiketal functional groups and accounted for 11% of weight of PERC PHF and 34% of the weight of BuckyUSA PHF. A small weight loss (6%) in stage 4 was observed for PERC PHF and is attributed to desorption of carbonyl or epoxide groups. No weight loss in stage 4 was observed in BuckyUSA PHF, suggesting an absence of carbonyl or epoxide groups. BuckyUSA PHF exhibited thermal degradation of structure resulting in further 19% weight loss, stage 5. No loss in stage 5 was observed for PERC PHF. The total weight loss up to a temperature of 1,000° C. was 54% for enhancing PHF. TGA shows that the ratio of the weights of hemiketal to hydroxyl groups is higher for BuckyUSA PHF. A higher proportion of hemiketal to hydroxyl groups was also observed by XPS.
Where R is defined as the ratio of other functional groups to hydroxyl groups, as determined by XPS analysis, the values of R for PERC and BuckyUSA PHF are 0.27 and 1.66, respectively. The higher R for the BuckyUSA PHF correlates to a lower stability PHF, as observed by thermal degradation at temperatures greater than 800° C., as indicated in FIG. 6 .
Enhancement of Electron Scavenging Ability of PHF
Enhancement of the electron scavenging ability of PHFs by controlling the composition of the PHFs was undertaken by comparing dye degradation in the presence of different PHFs with TiO 2 .
Photocatalytic Dye Degradation
Dye degradation experiments were conducted with anatase (5 nm, Alfa-Aesar) titanium dioxide as the photocatalyst. A photocatalyst suspension was prepared by sonicating 30 mg/L of anatase for 1 hour. PHF was added to the suspension to give a final concentration of 0.03 mg/L. The dye, Procion Red MX5B, was added to the photocatalyst suspension to give a final concentration of 3 mg/L. The reaction mixture was transferred to a Petri dish with a magnetic stirrer and placed 100 mm below a bank of 16 UVA lamps (Southern New England Ultra Violet Company, Branfield, Conn.). The mixture was stirred in the dark for 10 minutes and then exposed to UVA at an intensity of 86 W/m 2 . Immediately prior to turning on the lights, two 1.5 mL samples were transferred using a pipette into plastic vials. Subsequent samples were collected at 15 minute intervals for one hour. Each collected sample was centrifuged twice at 10,000 g for 15 minutes and the final supernatant was transferred to a plastic (PMMA) cuvette. UV-Vis spectra were obtained, and the absorbencies at 512 nm and 538 nm were used for data analysis. The log of normalized sample absorbance was plotted against irradiation time and the slopes measured to obtain pseudo-first order degradation coefficients.
Photocatalytic degradation studies of Procion Red dye with TiO 2 free of PHFs, TiO 2 combined with PERC PHFs, and TiO 2 combined with BuckyUSA PHFs are presented in FIG. 7 , which plots the first order degradation of the dye over the period of an hour. The ratio of PHF to TiO 2 was set to a value of 0.001. The activity of PHF was determined by its ability to enhance the rate of photocatalytic degradation of the dye. The pseudo-first order rate coefficient for TiO 2 with PERC PHF (0.0128±0.0029 min −1 ) was 2.6 times higher than the rate coefficient for TiO 2 without PHF (0.0048±0.0005 min −1 ). Presence of BuckyUSA PHF gave a somewhat inhibited photocatalytic rate that was lower but not significantly different (α=0.05) than TiO 2 free of PHFs.
All patents, patent applications, provisional applications, and publications referred to or cited herein, supra or infra, are incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification.
It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application. | Polyhydroxyfullerenes (PHFs) having enhanced electron scavenging capabilities have a ratio of non-hydroxyl functional groups to hydroxyl functional groups that is less than or equal to 0.3. When combined with a semiconductor photocatalyst, such as titanium dioxide nanoparticles, the PHFs provide a photocatalyst for degradation of chemical and biological contaminates with an efficiency of at least twice that of titanium dioxide nanoparticles free of PHFs. The PRFs are included in these catalysts at a weight ratio to titanium dioxide of about 0.001 to about 0.003, whereas significantly lower and higher ratios do not achieve the highly improved photodegradation capability. PHFs outside of the desired structure are shown to be of little value for photodegradation, and can be inhibiting to the photocatalytic activity of TiO 2 . The enhanced electron scavenging PHFs can be employed as a component of materials for solar cells, field effect transistors, and radical scavengers. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a technique for creating a mini time key from a time key with which decryption at a specific time is enabled, and in particular to a technique for reducing the size of the time unit allocated for decryption using a mini time key without a corresponding increase in the number of time keys.
2. Description of the Related Art
In the present invention, a mini time key creation method and a management (transmission and maintenance) method for its use will be explained. Generally, the number of time keys to be managed is increased in order to reduce the unit time allocated for decryption. However, according to the present invention, the unit time can be shortened without a corresponding increase in the number of time keys that are to be managed.
The time key is used for a system to prevent the decryption of data until a specific time has been reached. In this system, a time key manager that manages a time encryption key keeps a time decryption key secret until a specific time, and after that, releases the time decryption key for public use.
In order to shorten the unit time allocated for decryption, many time keys that correspond to the unit time must be created. For a unit time of one day, for example, 365 time keys must be created and managed for one year (a time key for Jan. 16, 1998 or a time key for Jan. 17, 1998). However, for a unit time of one minute, 525,600 time keys must be created and managed for one year (a time key for 10:28 AM on Jan. 16, 1998 or a time key for 10:29 AM on Jan. 16, 1998). As is described, the number of time keys to be managed is normally increased in order to reduce the unit time allocated for decryption. Since a system having the highest security is required for the management of the time keys, the creation of as small as possible number of time keys is desired. Taking into consideration an application that uses a time key, the shorter the unit time is allocated for decryption, the more flexibly can the operation be performed.
A time key employing asymmetric key encryption is described in “Secure Electronic Sealed-Bid Auction Protocol With Public Key Cryptography,” M. Kudo, IEICE Trans. Fundamentals Of Electronics, Communications And Computer Sciences, Vol. E81-A, No. 1, 1998. And a time key employing symmetric key encryption is described in “Time-Lock Puzzles And Timed-Release Crypto,” R. L. Rivest, A. Shamir and D. A. Wagner, NIT Laboratory For Computer Science, pp. 1-9, 1996 Time-Lock Puzzles. Both references are concerned with the unit time key, and do not teach the method of the present invention whereby a mini time key is created from a unit time key in order to reduce the time unit allocated for decryption without a corresponding increase in the number of time keys.
It is, therefore, one object of the present invention to provide a method and a system for creating a mini time key from a time key.
It is another object of the present invention to provide a method and a system for performing encryption using a mini time key and a unit time key.
It is an additional object of the present invention to provide a method and a system for transmitting a mini time key and a unit time key.
It is a further object of the present invention to provide a method and a system for decrypting encrypted data using a mini time key and a unit time key.
It is still another object of the present invention to provide a time key server with which a user can freely use a mini time key and a unit time key.
It is a still additional object of the present invention to provide a time key management method whereby a time key management function does not have to manage an enormous number of time keys when using a mini time key and a unit time key, and a time key management system.
SUMMARY OF THE INVENTION
To achieve the above objects, a plurality of mini time keys are created within a unit time period that correspond to respective subintervals of the unit time period. First, a unit time decryption key is prepared immediately after the unit time period is reached. Then, a mini time key for the last subinterval of the unit time period is created by applying a one-way function to the unit time decryption key. A mini time key for each subinterval before the last subinterval is then created by iteratively applying a one-way function to the mini time key created for the following subinterval, beginning with the last subinterval and ending with the first subinterval of the unit time period. In other words, the mini time keys are created as a timed series arranged in a descending order beginning with the mini time key created for the last subinterval. In this manner, even when a specific mini time key is externally leaked for a specific reason, a mini time key for a later subinterval in a timed series can not be created by using this mini time key. In addition, even when the mini time keys are sequentially published, the security of the unit time decryption key is maintained.
With the above described arrangement, it is possible to build a time key server that is similar to a conventional time server in order to create a unit time key and a mini time key. A user can employ the time key released for public use by the time key server to construct various applications.
For example, a network examination system and an electronic sealed-bid auction system can be constructed. When there are regulations inhibiting reading or the revealing of specific data before a specified time, electronic distribution is made of all of a block of data containing a specific portion that has been encrypted using the time key, and at the specified time, a time decryption key is acquired that can read the contents of the encrypted data.
The time unit employed for the present invention is flexible, i.e., an appropriate time can be selected, such as a unit of one day or a unit of one minute or three minutes. When the mini time key of the present invention is employed, the time key management function does not have to manage a large number of time keys.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the transient relationship between a unit time key and a mini time key.
FIG. 2 is a diagram showing a mini time key creation method.
FIG. 3 is a diagram showing, along a time axis, a method for managing a mini time key and a unit time key.
FIG. 4 is a diagram showing the relationship between a mini time key and a unit time key.
FIG. 5 is a diagram illustrating an example network examination system.
FIG. 6 is a diagram illustrating an example electronic sealed-bid auction application process.
FIG. 7 is a flowchart showing the mini time key creation processing.
FIG. 8 is a flowchart showing the mini time key creation processing.
FIG. 9 is a diagram illustrating a hardware arrangement according to one embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The terms used in the following embodiment are defined as follows:
time key: A key used for encryption and decryption in accordance with the time. When a decryption key that is used for decrypting encrypted data is released for public use after a specific decryption time period has elapsed, such a key is called a time key. The method for creating the time key and the encryption and decryption methods are the same as those used for an asymmetrical key (e.g., an RSA) and a symmetrical key (e.g., a DES) employed for normal cryptography.
mini time key: A time key for a small time unit that is created from a time key for which the decryption time is based on a longer time unit. In FIG. 1, mini time keys 11 - 13 and 21 - 23 correspond to this key.
time encryption key: An encryption key used for data encryption in accordance with the time, regardless of whether it is an asymmetrical key or a symmetrical key.
time decryption key: A decryption key used for data decryption in accordance with the time, regardless of whether it is an asymmetrical key or a symmetrical key.
asymmetrical time encryption key: A public key for an asymmetrical key used for data encryption.
asymmetrical time decryption key: A secret key for an asymmetrical key used for data decryption.
symmetrical time key: A symmetrical key used for data encryption and decryption.
encryption using an asymmetrical encryption key: For data encryption using an asymmetrical key, data are encrypted first using a temporary symmetrical key, and then the symmetrical key is encrypted using an asymmetrical key.
time key management server (system): A special system for managing a time key.
unit time key: A time key that is a base for the creation of a mini time key. The unit time key in this invention can be either an asymmetrical key or a symmetrical key. In FIG. 1, unit time keys 1 and 2 correspond to this key.
unit time: A shortest time interval that can be used for the creation of unit time keys, or mini time keys, that differ from each other. When the unit time of a unit time key is one day, a different time key is created for every day.
subinterval: A subdivision of a unit time period corresponding to a particular mini time key. FIG. 1 thus shows a unit time period of one day (24 hours) divided into three subintervals of 8 hours each.
The descriptions used in the embodiment are defined as follows:
M 1 M 2 : Linking of data M 1 and data M 2 .
PK X : An asymmetrical public key for X (not a time key but a normal public key for signature examination).
SK X : An asymmetrical secret key for X (not a time key but a normal secret key for a signature).
PK X, t=t1 : An asymmetrical time encryption key for X. Decryption time is t1.
SK X, t=t1 : An asymmetrical time decryption key for X. Decryption time is t1.
K X : A symmetrical secret key for X (not a time key but a normal encryption key).
K X, t=t1 : A symmetrical time key for X. Decryption time is t1.
{M}PK X : Encryption of data M using an asymmetrical public key for X, or examination of a signature for data M.
{M}PK X, t=t1 : Encryption of data Musing an asymmetrical time encryption key for X.
{M}SK X : Decryption of data M using an asymmetrical secret key for X, or a signature for data M.
{M}SK X, t=t1 : Decryption of data M using an asymmetrical time decryption key for X.
{M}K X : Encryption of data M using a symmetrical key for X.
{M}K X, t=t 1: Encryption of data M using a symmetrical time key for X.
{M}K −1 X, t=t1 : Decryption of data Musing a symmetrical time key for X.
f(M), f′(M): A value of data M obtained using a one-way function f or f′. A property of the one-way function is that it is difficult to acquire the original argument M from the value because a large number of calculations must be performed. For example, a hash function.
FIG. 7 is a flowchart illustrating a mini time key creation system. First, at block 710 a unit time decryption key is created. Then, at block 720 the value of the last mini time key in a time unit to which the mini time key corresponds is calculated (created) by applying a one-way function to the unit time decryption key. At block 730 a desired mini time key is created by applying a one-way function to a mini time key following the desired mini time key.
FIG. 8 is a flowchart for a mini time key creation method. First, at step 810 a value for the last mini time key in the time unit to which the mini time key corresponds is calculated by applying a one-way function to a unit time decryption key. At step 820 a desired mini time key is created by applying a one-way function to a mini time key following the desired mini time key. At step 830 a check is performed to determine whether the values of all the mini time keys have been calculated. If the decision is NO, program control returns to step 820 . When the decision is YES, the processing is thereafter terminated.
The mini time key creation step, shown in FIG. 2, will now be described more in detail.
Step 1:
A unit time decryption key for t=t2 is created. More specifically, a unit time decryption key is created that is used for a succeeding time unit (t=t2) in the time unit (t1≦t<t2) to which the mini time key corresponds.
Step 2:
The value is calculated for the last mini time key in the time unit to which the mini time key corresponds. The value of the key is defined as one that is obtained by applying the one-way function (f) to the value of the unit time decryption key at step 1.
Step 3:
The value of the mini time key preceding the mini time key obtained at step 2 is defined as being a value acquired by applying the one-way function (f′) to the value of the acquired mini time key.
Step 4:
The calculation at step 3 is repeated until the time at which the time unit corresponding to the mini time key starts.
The data encryption method using the mini time key and the unit time key comprises the following steps.
Step 1:
When a time encryption key for decryption time t1 is requested by a time key user, a time key management server transmits a pertinent unit time encryption key PK X t=t1′ (for example, a unit time encryption key for the latest decryption time (t1′) that does not exceed t1). It should be noted that step 1 should be selected when the security is a more important consideration, but that it can be skipped.
Step 2:
The time key management server employs a mini time key (K X, t=t1″ ) to encrypt a message (M) received from the user, and transmits {M}K X, t=t1″ (for example, a mini time encryption key for the first decryption time (t1″) after time t1 has elapsed). When a pertinent K X, t=t1″ is not found or is not required, this step can be skipped.
Step 3:
The user employs the acquired unit time key PK X, t=t1′ to encrypt data as {{M}K X, t=t1″ }PK X, t=t1′ . These are the data that are encrypted using the unit time key PK X, t=t1′ and the mini time key K X, t=t1″ .
It should be noted that the above step 3 should be selected when the security is a more important consideration, but that it can be skipped.
The method used for managing (transmitting or storing) the mini time key and the unit time key comprises the following steps.
Step 1:
The time key management server securely holds the unit time decryption key (SK X, t=t11 ) for the decryption time t11 until that time is reached.
Step 2:
When a user of the time key decryption issues a request to the time key management server for decryption at the decryption time t11, the time key management server transmits the unit time decryption key (SK X, t=t11 ) for the decryption time t11. This step is selected only when security is a more important consideration, and need not always be performed.
Step 3:
When a period of time (n*stp) that is a multiple of the unit time (stp) for the mini time key has elapsed after the time t11 is reached, and when the time key management server receives a request from the time key decryption user for decryption for the decryption time t1n (=t11+n*stp), the time key management server transmits a pertinent mini time key (K X, t=t11+n*stp ) to the user. At this time, the value of the mini time key (K X, t=t11+n*stp ) can be calculated using the above described mini time key creation step, or the value of the mini time key that is securely stored in the time key management server can be employed.
Step 4:
The time key management server repeats step 3 until time t21 for the next unit time key is reached.
The method used for managing the mini time key and the unit time key follows along the time axis shown in FIG. 3 . SK X, t=t11 at t=t12, SK X, t=t11′ at t=t13, and SK X, t=t21 at t=t22 are not always transmitted, and can be selected as needed.
The mini time key management method can be stored before and after the time at which the mini time key is released for public use. For example, before being released for public use, the value of the mini time key may be stored and managed by the server. Instead of being stored, the value of the mini time key may be calculated by the server upon the request for the mini time key.
After the mini time key is released for public use, its value need no longer be managed because the value of the mini time key can be unconditionally acquired from the value of a time unit decryption key using the one-way function (assuming it is released for public use).
The method used for decrypting encrypted data using the mini time key and the unit time key comprises the following steps.
Step 1:
A time key decryption user acquires a unit time decryption key (SK X, t=t11 ) and a mini time key (K X, t=t1n ) (where t1n=t11+n*stp) in order to decrypt encrypted data E. It should be noted that the acquisition of the unit time decryption key (SK X, t=t11 ) is selective. If the data were encrypted using a unit time encryption key, a unit time decryption key is also acquired.
Step 2:
The user calculates {E}K −1 X, t=t1n , where K −1 X, t=t1n =K X, t=t1n . The obtained data are the original data. At this step, the user calculates {{E}SK X, t=t11 }K −1 X, t=t1n when the data were encrypted using the unit time decryption key and the mini time key.
The preferred embodiment of the present invention will now be described while referring to the accompanying drawings. In FIG. 9 is shown an example hardware arrangement for a system 100 according to the present invention. The system 100 includes a central processing unit (CPU) 1 and a memory 4 . The CPU 1 and the memory 4 are connected via a bus 2 and an IDE controller 25 to a hard disk drive 13 (or to a storage medium driver such as an MO, a CD-ROM or a DVD), which is an auxiliary storage device. Similarly, the CPU 1 and the memory 4 are connected via the bus 2 and a SCSI controller 27 to a hard disk drive 30 (or to a storage medium driver such as an MO 28 , a CD-ROM 29 or a DVD 31 ), which is an auxiliary storage device. A floppy disk drive 20 is also connected to the bus 2 via a floppy disk controller 19 . The system 100 performs time key creation, time key management, time key encryption, time key decryption, and time key transmission/reception. A time key management server has the same structure.
A floppy disk is inserted into the floppy disk drive 20 , and a computer program code or data, which interacts with an operating system and issues commands to the CPU 1 , etc., for implementing the present invention, is stored either on the floppy disk or on a hard disk drive 13 (or a storage medium, such as an MO, a CD-ROM or a DVD) and in a ROM 14 , and is loaded into the memory 4 for execution. The computer program code may be compressed, or may be divided into a plurality of segments and stored on a plurality of media.
The system 100 further includes user interface hardware components, such as a pointing device 7 (a mouse or a joystick) or a keyboard 6 for data entry, and a display 11 for providing visual data for a user. A printer and a modem can be connected to the system 100 via a parallel port 16 and a serial port 15 , respectively. The system 100 can also be connected to a network via the serial port 15 , the modem or a communication adaptor 18 (an ethernet or a token ring card) for communication with other computers. A remote controlled transceiver may be connected to the serial port 15 or to the parallel port 16 for the exchange of data using infrared rays or electric waves.
Via an amplifier 22 , a loudspeaker 23 receives an analog audio signal, which is obtained by D/A (digital/analog) conversion performed by an audio controller 21 , and outputs it as sound. The audio controller 21 receives audio data from a microphone 24 and performs an A/D (analog/digital) conversion of it, and fetches external audio data.
It can be easily understood that the system 100 of the present invention may be provided as an ordinary personal computer (PC), a workstation, a notebook PC, a palmtop PC, a network computer, a home electric appliance, such as a television that incorporates a computer, a game machine having a communication function, a telephone, a facsimile machine, a portable telephone, a PHS, a communication terminal, including a personal digital assistant, having a communication function, or a combination of such devices. In addition, the previously described components are merely examples; not all the listed components are required for the system 100 .
1. Examination System
Example regulations covering the administration of tests incorporate timing factors. With the Test of English for International Communication (TOEIC), for example, a hearing test is administered that continues for several minutes following the start of the examination, and during this time viewing the pages of a writing test is prohibited. When a test is so regulated that the viewing of specific data before a specified time is inhibited, the specific data portion can be encrypted in advance using a time key and the data in which that portion is included can be electronically distributed across a network. When handled in this fashion, it is not necessary to make a real time special distribution of only the specific, pertinent data several minutes later a test has begun, for when the specified time is reached, the time decryption key is supplied and can be used to read the encrypted data. For such timing, however, if one day is employed as the time unit for the time key, it would be extremely difficult to administer an examination. But when a time key is created for which the time unit is one minute, using the method of the present invention an examinee can start a test at any time within the one minute unit time. Also, as one of the advantages afforded by the present invention, the time key management function need not manage a great number of time keys.
A network examination system (FIG. 5) employing a bulletin board system performs the following steps.
Step 1:
A time key management server (manager) 510 securely stores a unit time decryption key (SK X, t=t11 ) for a decryption time t11 until that time is reached. The time key management server securely stores, until time t11, a value (ft2=f(SK X, t=t21 )) obtained by applying the one-way function to the value of the unit time decryption key (SK X, t=t21 ) for the time unit following the decryption time t11.
Step 2:
When the time t11 has elapsed, the time key management server 510 posts on a bulletin board 520 the unit time decryption key (SK X, t=t11 ) for the time t11.
Step 3:
When a period of time, (n*stp), that is a multiple of the unit time (stp) for the mini time key has elapsed following time t11, the time key management server 510 releases for public use the mini time key (K X, t=t1n ) for the decryption time t1n.
Step 4:
The time key management server 510 repeats step 3 until time t21 for the next unit time key is reached.
In FIG. 5, the time key management server 510 creates a unit time key for one day and mini time keys for one minute each, and every minute posts on the bulletin board 520 the unit time key and the mini time key. Upon receipt of an examination request from an examinee X ( 540 ), an examination sponsor 530 uses a mini time key to encrypt one part of the questions for an examination, and transmits the entire examination to the examinee X. In this case, the examinee X should be prepared to begin the examination five minutes, for example, after receiving the data. Five minutes after the data is received, the examinee X can acquire from the bulletin board 520 a mini time decryption key to be used for the encrypted data on the first page of the test, and will then be able to begin the examination. Then, 40 minutes after the test began, the examinee X can acquire from the bulletin board 520 a mini time decryption key to be used for the encrypted data in the next section of the test, and can start the next section. An examinee Y ( 550 ) independently of the examinee X and the sponsor, can also begin the examination at any time within the one minute unit time.
2. Electronic Sealed-Bid Auction System
An electronic sealed-bid auction system is a system whereby when a bid is submitted, the offered price is enclosed in a special electronic envelope that remains sealed until a specified time. In this case, a time key is employed as a special electronic envelope, and the offered price should be securely stored, so that it can not be decrypted until a specified decryption time. In order to reduce the time unit for the decryption time, a unit time key and a mini time key are employed that use the method of the present invention. Thus, the publication time can be determined by using a one minute unit, and flexible bidding rules can be set. Since the method of the present invention is employed, the time unit for the decryption time can be shortened, and the number of keys that the time key management center must manage is not increased.
In FIG. 6 is shown an example electronic sealed-bid auction application process. A tenderer X ( 620 ) acquires a unit time encryption key for a decryption time t1 and a mini time encryption key from a time key management center 610 , and uses them to encrypt a bidding price. The tenderer 620 then transmits the encrypted bidding price to the bidding management center 650 . Other tenderers, such as the tenderers Y ( 630 ) and Z ( 640 ) shown, may submit bids in a similar manner. After the elapse of the decryption time t1, the bidding management center 650 acquires a unit time decryption key and a mini time decryption key from a time key management center 610 and uses them to decrypt the received encrypted information. When all the bid prices have been decrypted, the lowest bid price can be selected as the contract price, and the bidding management center 650 can then announce the results of the bidding.
Advantages of the Invention
When the mini time key of the present invention is employed, the time unit for decryption can be shortened without increasing the number of time keys that the time key management server must manage.
In FIG. 4, the time keys that the time key management server must manage during the period extending from t11 to t31 include only SK X, t=t11 and SK X, t=t21 . The mini time keys K X, t=t12 , K X, t=t13 , K X, t=t22 and K X, t=t23 need not be managed because after the time (t21), when the mini time key SK X, t=t21 is released for public use, the mini time keys K X, t=t12 and K X, t=t13 can be easily calculated using the one-way function (f, f′). Similarly, after the time (t31), when the mini time key SK X, t=t31 is released for public use, the mini time keys K X, t=t22 and K X, t=t23 can be easily calculated using the one-way function (f, f′). When the mini time key K X, t=t12 is released for public use at time (t12), while taking into account the property of the one-way function, it is difficult to calculate the value of the unit time decryption key SK X′ t=t21 using only the value of the mini time key. Therefore, the security of the unit time decryption key is maintained even when the mini time keys are sequentially released for public use. | To provide a method and a system for creating a mini time key from a time key, a plurality of mini time keys are created within a unit time period. First, a unit time decryption key is prepared immediately after the unit time is created. Then, the last mini time key is created by applying a one-way function to the unit time decryption key. A desired mini time key is created by applying the one-way function to a mini time key following the desired mini time key. In other words, the mini time keys are created as a timed series arranged in a descending order beginning with the last mini time key. In this manner, even when a specific mini time key is externally leaked for a specific reason, a following mini time key in a timed series can not be created by using this mini time key. In addition, even when the mini time keys are sequentially published, the security of the unit time decryption key is maintained. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to the interfacing of a gaseous source of sample material to an analyzer that requires a vacuum to operate.
Some analytical instruments require a high vacuum for successful operation, for example mass spectrometers. At the same time it is sometimes necessary to admit a certain amount of a gaseous sample for analysis from a high pressure region, often at atmospheric pressure. Any such inlet material needs to be pumped away by the high vacuum pump in order to maintain the vacuum required by the analyser. It is a feature of most vacuum pumps that they pump at a roughly constant volume flow rate and that the higher the flow rate required the more expensive the pump. This implies that a given mass flow rate is more expensive to pump away if the pressure at which the pump is operating is lower. For example, a vacuum pump operating at 10 -5 mbar would have to have 10 times the volume rate capacity of a pump operating at 10 -4 mbar in order to achieve the same mass flow rate.
In principle sample gas could be admitted from the high pressure source to the vacuum system through a single very small aperture with a single high vacuum pump operating at the pressure of the analyser. Such a leak would however have to be very small indeed and therefore difficult to interface to the source of analytical material. For example, suppose that the available pump capacity is 400 liter/sec (say a turbo-molecular pump weighing 20 pounds and costing some .English Pound.4000), the analyser requires to be at 10 -5 mbar to operate successfully and the inlet is an aperture from atmospheric pressure straight into the vacuum. The effective pumping speed at atmospheric pressure is approximately 400 liter/sec÷10 8 , the pressure ratio, which equals 4 μliter/sec. A thin aperture from atmosphere to vacuum allows a volume flow rate of 200× A m 3 /sec where A is the cross sectional area of the aperture in square meters. This implies an aperture area of 20 μm 2 , or an aperture diameter of ˜5 μm. Difficulties would arise because of the tendency of the leak to block, particularly if there are condensable components in the analytical stream. There may also be other reasons why the sampling aperture may not be this small. For example, in the particular case of sampling from an inductively coupled plasma, the sampling aperture must be larger than the plasma boundary layer in order to sample the plasma effectively (see J. A. Olivares and R. S. Houk, Anal. Chem. 57 p2674, 1985) leading to an aperture typically 0.5 to 1 mm. Often the pressure is reduced from atmospheric to the spectrometer operating pressure in more than one stage, such a system usually being referred to as a differential pumping system. Between each stage there is a small aperture, 0.1 to 1 mm in diameter, which separates a higher pressure region from a lower pressure region and each stage has its own pump. Typically the first vacuum stage is pumped with a rotary pump to 1 to 10 mbar, the second stage is pumped with a diffusion pump or turbo molecular pump to 10 -4 to 10 -3 mbar and the third stage is pumped with a high vacuum pump to 10 -6 to 10 -5 mbar. This way the bulk of the sample admitted is pumped away at relatively high pressures thus keeping down the capacity of the pumps used. Of course the consequence is that only a very small portion of the sample admitted through the first aperture actually travels all the way into the analyser space.
U.S. Pat. No. 3801788 discloses a method and apparatus for mass marking in mass spectrometry which provides molecule clusters at regular mass intervals over a mass range. U.S. Pat. No. 5049739 discloses a plasma ion source mass spectrometer with resonance charge exchange reaction and ion energy analysing sections which separate fast neutral atoms and slow disturbing ions. EP-A-0532046 discloses a vacuum device for a mass spectrometer with atmospheric pressure ionisation.
It is the object of the present invention to increase the proportion of the sample available to the analyser whilst at the same reducing the capacity and hence cost of the pumping required.
SUMMARY OF THE INVENTION
According to the present invention there is provided, a sample inlet apparatus comprising:
a sample source;
a first enclosure, connected to the sample source via a first inlet means;
an analyser enclosure, connected to the first enclosure via a second inlet means substantially in alignment with the first inlet means;
a second enclosure, connected to the analyser enclosure via a third inlet means substantially in alignment with the first and second inlet means; and
means for maintaining the first and second enclosures at a pressure lower than the sample source and higher than that of the analyser enclosure in use, whereby a molecular beam of sample molecules is generated along the axis of the inlet means alignment.
Preferably, the second inlet means comprises a single inlet, the third inlet means also comprises a single inlet, and the ratio of the distances between the two single inlets and the first inlet means is substantially the same as the ratio of their diameters, although the second inlet means may comprise two aligned inlets, the first inlet connecting the first enclosure to the second enclosure and the second inlet connecting the second enclosure to the analyser enclosure.
Alternatively, the apparatus may comprise a third enclosure, the pressure maintaining means maintaining the third enclosure at a pressure lower than the first enclosure and higher than the analyser enclosure, the second inlet means comprising two aligned inlets, the first inlet connecting the first enclosure to the third enclosure, and the second inlet connecting the third enclosure to the analyser enclosure, the third inlet means may then comprise a single inlet, with the ratio of the distances between the third inlet means and the first inlet means and between the second inlet of the second inlet means and the first inlet means and the ratio of their diameters being substantially the same.
Preferably, the sample source includes means for atmospheric pressure ionisation so that the molecular beam includes a proportion of ions. There may also be provided means for extracting ions from the molecular beam within the analyser chamber, and means for ionisation can be provided within the analyser enclosure. The analyser chamber may also contain a time-of-flight mass spectrometer.
According to the present invention there is also provided a method of supplying a sample of molecules or ions to an analyser enclosure under vacuum, the method comprising the steps of:
forming a molecular beam which includes the sample and in which the density of molecules is at least an order of magnitude higher than the density of molecules in the background vacuum of the analyser enclosure;
directing the molecular beam across the analyser enclosure and through an aperture into a pumping enclosure where the background pressure is higher but nevertheless a vacuum exists sufficient that the mean free path of the background gas molecules is significantly greater than a dimension of the aperture, the aperture being placed and being of such dimensions so as to allow free passage of the bulk of the molecular beam whilst at the same time being sufficiently small that, notwithstanding the pressure being higher in the pumping enclosure than in the analyser enclosure, the mass flow rate of gas backstreaming from the pumping enclosure to the analyer enclosure through the aperture is substantially less than the mass flow rate of the portion of the molecular beam passed through the aperture in the opposite direction.
Preferably, the sample is at first supplied to a first enclosure at low pressure with the flow into the first enclosure occurring as a supersonic expansion, the molecular beam being formed by an aperture positioned within the supersonic expansion. The molecular beam may be formed by passing sample molecules through a tube, the length of the tube being much greater than its diameter, the diameter being smaller than the mean free path of sample molecules in the tube.
Preferably, the sample molecules are partially ionised by atmospheric pressure ionisation prior to passing through the first inlet means, although the molecular beam may be ionised within the analyser enclosure, where the ions may be extracted from the molecular beam within the analyser enclosure.
The main principle of the invention is to create a directed molecular beam from the source gas and pass it through the vacuum region that contains the analyser, with minimal scattering, directly through a differential pumping aperture into a pumping region at a higher pressure. As in the conventional method of differentially pumped sources, the bulk of the sample is pumped at pressures higher than the background pressure in the analyser region. However in the case of an inlet which uses the present invention, source material passes through the analyser space, with the lowest background pressure, before entering a higher pressure region where most of it is pumped away. With this reversed differential pumping method much more of the source material is available in the analyser region than would be the case if all the higher pressure pumping had taken place first. The creation of a molecular beam is required because it is necessary for the net mass flow of gas from the analyser region to a pumping region to be positive even though the background gas pressures are such so as to cause gas to flow in the other direction. The molecular beam consists of many molecules travelling essentially in the same direction in the form of a slowly spreading beam with little interaction between molecules in the beam. The density of molecules in the beam may be very much higher than the density in the surrounding background vacuum and therefore an aperture placed in the path of the beam passes a high mass flow rate. The mass flow rate due to a difference in background pressures may be very much lower because the average molecular density is lower and the molecules are travelling in random directions.
A well known method for forming a molecular beam is via a supersonic expansion of gas at high pressure into a low pressure region through a small aperture (see D. M. Chambers, J. Poehlman, P. Yang, and G. M. Heiftje, Spectrochemical Acta. 46 p741 1991). Near this first aperture there is lots of scattering between molecules and somewhat further away from the aperture a shock wave forms where the incoming source gas interacts with the background gas molecules. In between these two regions there is a region of molecular flow, consisting still almost entirely of the incoming source gas, but with molecules no longer scattering one another. A second aperture, usually called a skimmer, placed in this region and leading to a higher vacuum region, extracts a molecular beam.
A second, method of creating a molecular beam is to allow gas to pass through a long thin tube at a pressure where the mean free path is very much greater than the diameter of the tube. Gas molecules emerging from the output of the tube are much more likely to have velocities parallel to the tube than at other angles, leading to a directed molecular beam.
Although the beam in question is referred to as a molecular beam, it may contain a proportion of ionic species. Indeed, where the analyzer is a mass spectrometer using a high pressure (for example atmospheric pressure) ionisation source, the whole purpose of the inlet system may be to transport as high a proportion of ions into the analyser space as possible. The principle of the invention still applies providing the mass flow in the analyser space is still largely directed in a beam that can be intercepted with a pumping aperture. In this case the ionic species of interest would be pulled out of the beam by electric or magnetic fields to be passed to the mass spectrometer whilst the bulk of the molecular beam passes on through the pumping aperture.
Similarly, ionic species may be created in the beam once inside the analyser vacuum space and then extracted into the analyser leaving the neutral species to pass on to the pumping stage. The ionisation means might itself require a good vacuum, for example electron impact ionisation or far ultra violet photoionisation. The reversed differential pumping arrangement according to this invention makes much more neutral material available to the ionisation source, thus leading to greater sensitivity for a given pumping capacity.
BRIEF DESCRIPTION OF THE DRAWINGS
A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:
FIG. 1 shows, in schematic form, an arrangement, according to the invention for an inlet from an inductively coupled plasma to a mass spectrometer; and,
FIG. 2 shows, in schematic form, an alternative arrangement according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The basic construction of apertures for sampling from an inductively coupled plasma is known. Otherwise the system consists of standard vacuum parts arranged according to the invention. Referring to FIG. 1 the source of sample gas is an inductively coupled argon plasma flame 1. Gas enters the first vacuum space 3 via a water cooled nickel aperture 2 of approximately 1 mm diameter. The first vacuum stage 3 is pumped by a rotary pump 4 to a background pressure of approximately 4 mbar. Assuming that the plasma temperature is around 5000 K. the flow rate through the first aperture 2 is approximately 10 21 atoms/sec. A second skimming aperture 5 of diameter 0.3 mm is placed 10 mm behind the first aperture in the molecular flow region of the expansion creating a molecular beam 6 that passes into the second vacuum stage 7. The molecular beam has a virtual origin approximately at the first aperture and so approximately 10 18 atoms/sec pass through the vacuum space 7 and the approximate diameter of the beam at various points downstream of aperture 5 is given by the diameter of skimmer aperture 5 multiplied by the distance at a particular point downstream from the first aperture 2 divided by the spacing between the first two apertures 2 and 5. Thus to include the whole beam a further aperture 9 placed 60 mm from aperture 2 needs to be approximately 2 mm in diameter. Aperture 9 leads to a further vacuum stage 10 pumped by a high vacuum pump 11 to a pressure of approximately 10 -3 mbar. The second vacuum region 7 is also pumped by a high vacuum pump 8. This is required to remove gas that backstreams from the higher pressure region 10 through the aperture 9. Electrostatic ion extraction electrodes 12 and 13 are placed either side of the beam to direct ions contained within the molecular beam towards a mass spectrometer 14. The bulk of the beam is unaffected by the extraction electrodes as ions represent only about 0.1% of the beam extracted from an inductively coupled plasma. An ionization device 16, which may be any one of several known devices, for example, a hot filament or ionization electrode may be provided in the sample chamber 7 to ionize the beam 6.
The capacity of the two high vacuum pumps 8 and 11 can now be calculated. The background vacuum gas in each vacuum region is at room temperature having undergone collisions with the vacuum system walls and the density is given by:
d=N.sub.A P/RT atoms/m.sup.3
where N A is Avagadro's number, P is the pressure in Pascals, T the temperature in Kelvin and R the gas constant (8.314 J K -1 mol -1 ). At 10 -3 mbar d=2.4×10 19 atoms/m 3 and at 10 -5 mbar d=2.4×10 17 atoms/m 3 The pump capacity required for a given vacuum region is simply:
C=1000 U/d liters/sec
where U is the rate at which gas enters the region in atoms/sec. So the vacuum pump 11 needs a capacity of approximately 40 liter/sec to pump away the 10 18 atoms/sec in the molecular beam entering the pumping enclosure 10. The backstreaming flow of background gas into the spectrometer chamber 7 can be derived from the following well known formula for flow through a thin aperture from a high pressure to a much lower pressure when the mean free path is greater than the aperture diameter, which in the case of a circular aperture is the characteristic cross-sectional dimension:
Ca=A(RT/2πM)m.sup.3 /sec
where A is the aperture area and M is the molar mass in Kg/mol -1 . For argon at room temperature through a 2 mm diameter aperture this works out at 0.31 liters/sec. The pump capacity of the high vacuum pump 8 must be 100 times this (i.e. 31 liters/sec) as it pumps at 10 -5 mbar whereas the leak rate just calculated is at 10 -3 mbar, the pressure in the pumping chamber 10.
In summary the inlet system requires one large rotary pump 4, whose capacity would be the same as an inlet using the conventional differential pumping and, for example, two small (50 liter/see) turbomolecular pumps. With this reasonably modest pumping requirement 10 18 atoms/sec of the plasma are available to the mass spectrometer. In a conventional differential pumping arrangement all the sample gas made available to the spectrometer has to be pumped away at the spectrometer background pressure. If the same 10 18 atoms/sec were pumped away at 10 -5 mbar it would require a pump with a capacity of 4000 liters/sec i.e. some two orders of magnitude greater in size. If turbo molecular pumps were preferred then this would be an inconveniently large size and a compromise would be probably made of 10 17 atoms/sec and a 400 liter/sec pump. So it can be seen that the invention can provide a system that is both more sensitive and less expensive.
Although sampling from an inductively coupled plasma is cited as an example it will be appreciated by those skilled in the art that various other analytical instruments could benefit from a reversed differential pumping arrangement. Several ionisation methods are currently used that already employ a supersonic expansion of gas. Examples include thermospray, plasmaspray, electrospray and corona discharge atmospheric ionisation sources. Where, as in these cases, the analyser is a mass spectrometer, ionisation could also be by electron impact with the molecular beam in the analyser stage or by photoionisation either in the analyser stage or upstream from it. Often these ion sources are used in conjunction with primary sample separation techniques such as liquid chromatography, gas chromatography or capillary electrophoresis that are normally benchtop instruments. A reduced pumping requirement for the mass spectrometer would be an important advantage.
Although the sources mentioned are basically gaseous in nature where they enter the vacuum inlet, the components being analysed may be non-volatile. Indeed it will often be the case that the analyte is entrained in a buffer gas. It partly for this very reason that excessively small apertures have a tendency to become blocked. Providing the analyte can be carried in a molecular beam the present invention may provide advantages.
The arrangement depicted in FIG. 1 is a relatively simple one. It will be appreciated by those skilled in the art that other arrangements are possible that follow the same basic principle. For example FIG. 2 shows an alternative arrangement wherein the pumping enclosure 10 pumps some of the gas before the molecular beam enters the analyser enclosure 7 as well as after the aperture 9. In this case a further aperture 15 has been added. Such an arrangement does not require a further pump and may allow more suitable aperture sizes to be used in some applications. It will be appreciated that the enclosure 10 of FIG. 2 could be replaced by two separate enclosures, one either side of the analyser enclosure 7.
It is a general feature of the geometry suggested that the spectrometer does not lie on the axis of the molecular beam. With some analyzers this may be a disadvantage, however if the analyser is a time-of-flight mass spectrometer then it is preferred to extract the ions at right angles to the molecular beam to minimise velocity spread in the direction of flight in the spectrometer. The invention is thus particularly well suited to the business of interfacing atmospheric pressure ion sources to a time-of-flight mass spectrometer. | A sample inlet apparatus comprises a sample source (1) and a first enclosure (3), connected to the sample source via a first inlet (2). An analyser enclosure (7) is connected to the first enclosure (3) via a second inlet (5,15) substantially in alignment with the first inlet (2). Also provided is a second enclosure (10), connected to the analyser enclosure (7) via a third inlet (9) substantially in alignment with the first (2) and second (5,15) inlet, and vacuum pumps (4,11) for maintaining the first (3) and second enclosures (10) at a pressure lower than the sample source (1) and higher than that of the analyser enclosure (7) in use, whereby a molecular beam of sample molecules is generated along the axis of the inlet. | 7 |
FIELD OF THE INVENTION
[0001] This invention relates to implantable and refillable drug delivery devices with programmable features.
BACKGROUND
[0002] Drug delivery by means of injections, inhalation, trans dermal or swallowing pills or capsules generally results in varying drug concentrations between dosings. Many diseases would be better treated if the therapeutic drug were given so as to obtain a more or less constant drug level in the region of interest, especially if systemic drug concentrations could be maintained at or near zero thereby minimizing side effects. Implantable drug delivery devices attempt to achieve this by delivering small amounts of drug to a specific body cavity on a frequent basis. These delivery systems also are capable of protecting drugs which are unstable in vivo and that would normally require frequent dosing intervals. Implantable drug delivery devices include polymeric implants, implantable osmotic pump systems, and micro-pumps.
[0003] Polymeric implants, used extensively in controlled drug delivery systems, include nondegradable polymeric reservoirs and matrices, and biodegradable polymeric devices. In both cases the drug is released by dissolution into the polymer and then diffusion through the walls of the polymeric device. The release kinetics of drugs from such systems depends on both the solubility and diffusion coefficient of the drug in the polymer, the drug load, and, in the case of the biodegradable systems, the in vivo degradation rate of the polymer. Examples of polymeric implants include simple cylindrical reservoirs of medication surrounded by a polymeric membrane and homogeneous dispersions of drug particles throughout a solid matrix of nondegradable polymers. Biodegradable polymeric devices are formed by physically entrapping drug molecules into matrices or microspheres. These polymers dissolve when implanted or injected and release drugs.
[0004] Another method for controlled prolonged delivery of a drug is the use of an implantable osmotic pump. An osmotic pump is generally in a capsule form having permeable walls that allow the passing of water into the interior of the capsule containing a drug agent. The absorption of water by the water-attracting drug composition within the capsule reservoir creates an osmotic pressure within the capsule to push the drug out of the capsule to the treatment site.
[0005] Implantable micro-pumps for drug delivery applications usually include a permeable membrane for controlled diffusion of a drug into the body from a suitable reservoir. Such devices are limited in application primarily since the rate at which the drug is delivered to the body is completely dependent upon the rate of diffusion through the permeable membrane. With these devices the rate of drug delivery to the body may be affected by differing conditions within the body. In addition, such systems make no provision for the adjustment of the rate or time interval for drug delivery, nor can the delivery rate be easily varied.
[0006] Although polymeric implants, osmotic pumps and micro-pumps may provide a relatively steady rate of drug release, some drugs are more effective given in intervals. Implantable infusion pumps can be programmed to deliver drugs at very precise dosages and delivery rates. These pumps may have a feedback device that controls drug delivery according to need. With the current development of electronics and miniaturization of pumps and sensors, various vital signs can be monitored leading to feedback systems such as for monitoring blood glucose levels and delivering insulin when needed. The size of the pump depends on the amount of drug and the intended length of treatment. A barrier in feedback technology in using an implantable sensor is the problem of body proteins causing reduced sensitivity of the sensors, compromising the reliability of the sensor input.
[0007] There are many existing examples of implantable medical device applications. Implantable insulin pump technology has been developed with a goal of simulating the normal function of the pancreas by using glucose sensors and the predictive mathematical models. The sensors would assess the level of glucose in the blood and pass the information to a control algorithm used in a microprocessor chip for causing appropriate action by the pump. Such a device delivers a dose of insulin through a catheter into a patient's abdominal cavity. According to one manufacturer a disk-shaped pump weight of about 5 to 8 ounces when filled can hold an insulin supply adequate for several months and can be refilled with a syringe injection across abdominal tissue with battery life lasting about eight to 13 years. This delivery system keeps the liver from secreting excess glucose (blood sugar) into the bloodstream. Current pump technology difficulties include blockage of the catheter, infection at the implantation site, as well as accidentally injecting insulin refills into patient's abdomen instead of the pump reservoir. A typical reservoir in an implantable pump is to be refilled every three months.
[0008] For pain relief, drug delivery devices include the SynchroMed, an externally programmable implantable device for the administration of morphine sulfate to treat chronic pain, and the AlgoMed, designed to treat intractable pain in cancer patients. The AlgoMed device includes a drug reservoir implanted just under the skin of the abdomen, and a small catheter that delivers medicine to the spinal cord.
[0009] The treatment of glaucoma presents several strong challenges to drug delivery implant technology due to the sensitivity of the eye which therefore requires more frequent and precise dosing of medication while the small anatomical space limits the size of an ocular implant device. The surface of the eye is a significant physical barrier to medications that target intraocular treatment sites. Topical eye drops must be able to permeate through the modified mucosal membrane that covers the cornea. Only a very small percentage (˜5%) of the eye drops actually reach the intraocular space. While drugs that are released rapidly produce a relatively rapid and high concentration in the body, followed by a sharp decline, it is preferable to have controlled-release systems deliver a drug at a slower rate for a longer period without manual application by patients. In many glaucoma treatments, two drugs are used; a first drug for reducing internal pressure inside the eye and a second drug for reducing side effects. It is, therefore, desirable to have a compact drug delivery device that can dispense two drugs with separate dispensing controls.
[0010] To improve the reliability and safety of an implantable drug delivery pump device, it is desirable to have a pump with a catheter with positive closing and a failsafe refilling process eliminating any possibility of injecting drug into a body cavity during the refilling process, an automatic notification feature to alert the patient of the need to take timely refilling action, as well as a process for verifying the performance of the pump. Preferably all of these desirable features can be achieved in an implantable drug delivery pump device using an implantable battery and without using an external controller.
[0011] To maintain a more constant rate of dispensing drug dosages, it is desirable to have an implant pump capable of precisely delivering a small amount of drug volume in the nano-liter range at each step of piston movement. It is desirable to infuse such minute dosages at time intervals appropriate for sustaining drug efficacy while avoiding side effects. And it is desirable to have an automated refilling process to prevent the injection of drug outside the implant pump into body tissues while refilling the pump.
[0012] The following references describe implantable devices.
[0013] U.S. Pat. No. 6,497,699 by Ludvig, et al. describes a miniature apparatus for the treatment of brain disorders. The apparatus is a combination of electronic and pharmacological devices placed and powered entirely within the human body. A neuroprosthesis monitors the electrical activity of a dysfunctioning brain area and delivers drug molecules into the problem area. The apparatus includes a refillable drug pump; a recording electrode for outputting an electrical signal characteristic of an electrical activity of the brain; and a microcontroller to control the dispensing of the drug based on the electrical signal. The timing and duration of the drug deliveries are determined by the feedback of the brain's own electrical activity. The invention describes an application of an implantable pump having multiple dispensing outlets for targeting different problem areas. However, no specific pump design is mentioned.
[0014] U.S. Pat. No. 5,832,932 by Elsberry, et al. discloses techniques and apparatus for infusing drugs into the brain to treat movement disorders. The invention employs an implantable pump and a catheter for infusing therapeutic dosages of the one or more drugs into the brain at treatment sites. A sensor for detecting the extent of the abnormal motor behavior may be used in combination with the implantable pump and catheter. The therapeutic dosage is adjusted according to signal input of the sensor to decrease the abnormal motor behavior. According to the patent the method is applicable to treat the symptoms of hypokinetic disorders, such as Parkinson's disease, and hyperkinetic disorders, such as Amyotrophic Lateral Sclerosis, Huntington's Disease, Ballism or Dystonia. The application of drug delivery device for treating movement disorder by brain infusion and the method of using a sensor for motion feedback for adjusting drug dosage in an implantable pump device are incorporated by reference.
[0015] For ophthalmic applications, U.S. Pat. No. 6,976,982 by Santini, Jr., et al. and U.S. Pat. No. 7,455,667 by Uhland, et al. provide a flexible microchip drug delivery device that attaches to the curved surface of an eyeball. The ophthalmic microchip device is in the form of an array of drug-containing microchips that are attached to a flexible supporting layer conforming to the backside surface of an eye. Release of the contents of each microchip reservoir is controlled by diffusion through, or disintegration of, the reservoir cap. The reservoir cap can be an anode made of thin film gold in electrical communication with a cathode in the device. When an electric potential of approximately 1 volt is applied the reservoir cap is oxidized to facilitate its disintegration, exposing the reservoir contents to the surrounding fluid. A microprocessor is preprogrammed to release drug from specific reservoirs by directing power from a battery to specific reservoir caps. Once released, the drug is in contact with the surface of the eye and diffuses into the eye. The reservoir activation can also be conducted wirelessly by telemetry with electromagnetic or optical means. An optical means can use an ophthalmic laser to activate LED receivers in the device. However, a potential problem with these devices is that the dissolved cap material is not removed and may even “re-solidify” when the power for dissolving the cap material is off.
[0016] The invention of U.S. Pat. No. 7,181,287 by Greenberg deals with retina stimulation by electrodes or by drug to enable vision in blind patients or treatment of a chronic condition. Specifically it is directed to an implantable device to enable delivery of drugs to the retina for stimulating the retina. The drug delivery device is secured by a tack to the retina at a desired location without damaging the retina and it is out of the field of vision from the lens to the retina. The device may be a passive osmosis type in the form of a hollow flexible polymeric pillow containing drug for slow release to deliver drugs through multiple orifices to the desired treatment sites. The device may also be an active pump type receiving drug from a reservoir transferred by a pressure development device through a tube with the flow rate controlled by a micro-valve. The microvalve, the pressure development device and the reservoir are attached to the sclera outside the eye under the conjunctiva for ease of refilling of the reservoir. Also by the same author, U.S. Pat. No. 7,483,750 specifically discloses preferred position of a retinal device and the connection between a device reservoir and the retinal device for avoiding damaging to the retina. The retinal implant is implanted subretinally at the back of the eye near the fovea between the photoreceptor cell layer and the retinal pigment epithelium. The conduit connects the retinal implant with the drug reservoir transretinally through retinal incision and the vitreous cavity. The preferred retina incision is at a location near the front of the eye where there is no retina to avoiding damage to the nutrient rich choroid and disruption of the blood supply to the retina. These two patents provide applications and suitable location of a drug delivery device for treatments of chronic eye conditions and indicate the feasibility of separating the small-size drug pillow positioned inside the retina layer from the larger size pump body positioned outside the eye. However, the patents do not address the mechanism of dispensing the drug in controlled manner. The use of an implantable pump for treating retinal diseases is incorporated by reference.
[0017] U.S. Pat. No. 6,077,299 by Adelberg, et al. deals with a non-invasively adjustable valve implant for the drainage of aqueous humor in glaucoma. The implant valve is a rotor-type device with the valve opening controllable by a magnetic field through an external instrument. The glaucoma valve of the invention overcomes the excess absorption problem of a newly implanted pump in a treatment area, where the aqueous humor is readily absorbed into the Tenon's tissue overlying the implant. Excess absorption can cause the pressure within the eye to fall to an unacceptably low level damaging eyesight. A higher pressure set-point can be made in the implant valve for the first few days after surgery to minimize the risk of the complications. The implant valve can also be adjusted to compensate for changes due to partial occlusion of the inlet tube by particulate matter and infiltration by body tissue. However, the valve implant of this invention is not a pump for dispensing drug. Nevertheless, the patent shows that non-invasive adjustability is required for an implant device.
[0018] For ocular drug delivery, U.S. Pat. No. 3,618,604 by Ness discloses a drug-dispensing ocular insert to deliver drug to the eye over a prolonged period of time. The ocular insert is comprised of either a flexible body of polymeric material or a sealed container having membrane walls insoluble in tear liquid and having an imperforate surface. The drug contained in the insert is diffused at a controlled rate through the polymeric material or the membrane walls to the eye in a therapeutically effective amount. The ocular insert is to be placed in the cul-de-sac of the conjunctiva between the sclera of the eyeball and the lower lid. The inserts depend on osmotic pressure difference to control drug delivery and they are not personalized for individual needs. Their diffusion rates are not changeable once installed. An implant pump with programmable timed release is desirable and to enable more varied applications.
[0019] U.S. Pat. No. 7,377,907 by Shekalim provides an insulin pump that supplies insulin in a pre-pressurized chamber through a flow control valve. Precise metering is achieved by a piezoelectric actuator. The insulin in the chamber is pressurized and dispensed by a piston, which is driven by a biased spring. The device also includes a pressure regulator, a removable cartridge unit containing a pre-pressurized fluid reservoir, and an electronic package for the programming of basal rates. Nevertheless, patients with a portal device are at risk for trans-cutaneous infections.
[0020] To ensure positive closure at the dispensing opening, U.S. Pat. No. 5,997,527 by Gumucio, et al. provides a drug delivery capsule device comprising an osmotic-agent chamber having a semi permeable membrane wall, a drug chamber attached with a slit valve, and a moveable piston separating the two chambers. Under an osmotic pressure created in the osmotic chamber, the piston pushes drug through the slit valve. Being exposed to the body tissue environment the permeable membrane wall of the osmotic chamber wall allows body fluid to pass into the capsule by osmosis to create an osmotic pressure to drive the piston. The osmotic capsule of this invention lacks active control for ensuring positive closing of the slit valve. In operation, the osmotic pressure varies with the movement of the piston and the remaining quantity of the drug in the drug chamber. At one end, an excessive osmotic pressure can keep the slit valve at open state with continuous dispensing with a possibility of over-dosing. At the other end, an insufficient osmotic pressure cannot drive the piston to open the slit valve resulting in no drug being dispensed. This unreliable drug delivery due to lack of active control can cause discomfort and adverse side effects in the patient.
[0021] On the use of two fluidic drug chambers, U.S. Pat. No. 5,607,418 by Arzbaecher provides an implantable drug delivery device having a deformable dispensing chamber within a deformable reservoir chamber. In this configuration, the dispensing flow rate of the dispensing chamber is designed to be greater than the refilling flow rate from the reservoir chamber and that the reservoir chamber automatically refills the dispensing chamber following discharge of a dispensing portion of the fluidic drug. Because the dispensing rate is greater than the refilling rate across the internal valve between the two deformable chambers, a partial vacuum may be created in the two chambers resulting in a poorly controlled dispensing rate or interruption of the dispensing flow to the treatment site. The deformable dispensing chamber within a deformable reservoir chamber cannot ensure that the drug flow rate in and out of the dispensing chamber and the reservoir chamber are equal.
[0022] U.S. Pat. No. 4,883,467 by Franetzki addresses the problem of gas bubbles in pumping medication fluid in a conventional implantable medication device using a reciprocating piston pump wherein the medication reservoir is typically under atmospheric pressure between 0.5 and 1.0 bar. Gas bubbles may be generated in pumping the medication fluid at below ambient pressure or during refilling of the medication reservoir. In the reciprocating motion in the pump chamber a gas bubble would be merely compressed and decompressed without being transported out of the device, making the infusion performance of the device unreliable. This under-pressure pumping is less a problem in larger pumps having a displacement volume greater than 10 microliters. But the existence of dead space in the pump chamber of a small pump is compounded because the size of the dead space may be comparable to the size of the displacement volume of the piston. In this case, pumping medication containing gas bubbles may become impossible particularly at the lower limit of the under-pressure (0.5 bar). This patent provides an implantable medication device using a magnetized reciprocating piston and a magnetic check valve for pumping medication fluid containing gas bubbles to achieve a satisfactory infusion rate such that the patient would receive medication without interruption by the gas bubbles. The piston contains a magnetic material which can be driven by a magnetic means to move the piston forward for dispensing and a separate magnetic means for moving the piston backward. The magnetic check valve is normally biased to block fluid flow.
[0023] Addressing the problem of gas bubble formulation, U.S. Pat. No. 7,201,746 by Olsen provides an implantable therapeutic substance delivery device having a piston pump with an anti-cavitation. The device has an inlet chamber and a pumping chamber. In the pumping chamber a piston having a permanent magnet is driven by the magnetic fields created by two separate inductive coils which impart a reciprocating motion to the piston to pump fluid from the pumping chamber into an outlet. In such a pump chamber the backflow of fluid from the inlet chamber can decrease pressure in the pumping chamber causing gasses to come out of solution when the pumping chamber is being filled with the fluid. The invention provides an anti-cavitation valve that is configured to open when the therapeutic substance inlet pressure exceeds the inlet chamber pressure and to close when the inlet chamber pressure exceeds the therapeutic substance inlet pressure. The objective of the anti-cavitation valve is to prevent the pumping chamber pressure from decreasing below a predetermined low pressure level during piston retraction and to enable more complete filling of the pumping chanter when the piston is retracted.
[0024] Both U.S. Pat. Nos. 4,883,467 and 7,201,746 utilize a magnetized piston driven by magnetic forces and attempt to suppress gas bubble formation by using biased valve mechanisms to increase the pressure in their pump chambers. However, without positive mechanical control of the piston, the piston movement under the magnetic forces depends on the pressure level in the pump chamber, which may vary in operation. Also, the compressed gas bubbles inside the pump chamber may expand when released at the device exit at the treatment site. Furthermore, these device configurations inherently entrap gas pockets and allow for the existence of dead space which is a major source of the pumping problem.
[0025] US Patent Application 20080287874 by Elmouelhi controls the dead volume of a piston pump by using an adjustment screw. The infusion pump device is of a reciprocating magnetized pistontype driven by solenoid coils. Typical manufacturing tolerances in the production of the pump components may result in unwanted dead space in the pumping chamber. The dead space includes space that the piston does not reach at the limit of its forward movement that leads to trapped air bubbles not displaced during the pumping strokes, the pumping volume of the piston may not be accurate as the piston movement may result in the compression of the air bubbles rather than displacement of the fluid. The invention solves the problem by adjusting the end position of the piston's forward stroke with an adjustment screw allowing for selective elimination of the dead volume and precise adjustment of the fluid pumped. Similarly US Patent Application 20080269682 by Kavazov et al. address the reservoir air bubble problems of a magnetized reciprocating piston pump by modifying the geometry of the plunger or the reservoir of the pump device. In various embodiments of the invention, a reservoir, a plunger head which moves within the reservoir, or both the reservoir and the plunger head are shaped to form a bubble trap region for trapping air bubbles so as to limit the presence of air bubbles in a fluidic medium expelled from the reservoir. Both of these patents recognize the existence of dead volume due to the structure of its piston pump device and attempt to minimize the air bubble problems. However, a piston pump that eliminates dead volume such that no air bubble problems exist would be preferable.
[0026] On refilling, U.S. Pat. No. 7,347,854 by Shelton, et al. relates to a process of refilling an implantable drug delivery device. The controller in accordance with this invention is programmed to determine the volume of the old drug remaining in the reservoir. The controller then monitors the subsequent delivery of the old drug to the patient to determine when the remaining old drug has been cleared from the device. Accordingly, the controller adopts a new dispensing profile for the drug refilled into the reservoir. The process as described in this patent is limited to the general practice of adding new drug after using up the original drug in the reservoir. No specific refill steps such as retracting a piston, closing a dispensing tip and using a passive syringe are addressed. In fact, a programmable pump allows changing the dispensing profile at any time depending on the need of a patient prior to using up the existing drug in the reservoir.
[0027] An implantable drug delivery pump of U.S. Pat. No. 6,283,949 by Roorda discloses a method of dispensing drug at a controllable rate from a reservoir. The pump includes a reservoir, a dispensing chamber, a compressible dispensing tube attached to the dispensing chamber, and a rotating-arm actuator for applying a compressive force onto the dispensing tube to deliver the drug through a catheter. The rotating-arm actuator allows additional drug drawn into the dispensing tube from the reservoir, which can be refilled. A one-way intake valve is used and the reservoir can be refilled through a septum. In this method, rotational actuator compressive force is used and the reservoir is limited to a circular configuration to accommodate the rotating arm. The patent does not address failsafe requirements for refilling a pump reservoir.
[0028] U.S. Pat. No. 4,784,646 by Feingold provides a subcutaneous delivery device for injecting drug to a local destination. The subcutaneous delivery device is mainly a catheter having a self-sealing port at the input end attached with an internal magnet and a valve at the output end. The catheter device further includes a corresponding external magnet, separated from the internal magnet by the skin, as a locator for magnetically adapting to the internal magnet. The attraction between the two magnets, which are annular magnets of opposite polarities, can facilitate positioning and stabilizing a syringe needle during injection. However, the syringe needle may still be inserted at wrong location and the drug in the syringe be injected by pressing the plunger of the syringe, therefore, causing damage to body tissues. Furthermore, the valve at the dispensing end of the device cannot be positively controlled for dosing as the internal pressure in the device may exceed the self-dosing pressure of the valve.
[0029] U.S. Pat. No. 7,044,932 by Borchard, et al. provides an access template for locating the refill septum of an implant drug pump. The needle insertion occurs without using radiological instruments for guidance. The access template comprises a denial surface, an access port, and template labeling. The denial surface has a periphery with a location diameter and an alignment feature. The denial surface is configured to prevent penetration through a dermal layer into the implantable drug pump. Using labels of the same color in both the template labeling and the needle labeling provides a means for ensuring the proper drug being administered but the system is not failsafe as negligence in matching colors may occur.
[0030] To locate an implantable pump for the purpose of refilling, U.S. Pat. No. 7,191,011 by Cantlon discloses the use of a port with light emitters. The light emitters can be arranged in various geometric forms and colors. Also disclosed are energy emitters such as light emitting diodes, edge emitting diodes, or VCSELs, and sonic emitters. The concepts as disclosed are not applicable for situations where light or sonic waves cannot be detected such as under the skull. Furthermore, U.S. Pat. No. 7,356,382 by Vanderveen describes a system and method for verifying that a particular fluid supply is connected to an infusion pump by means of an operator-induced pressure change. An upstream pressure sensor coupled to a fluid supply conduit provides pressure signals to a processor. In a verification mode, the processor receives the pressure sensor signals in comparison with an operator-induced pressure change in the conduit to verify that the particular fluid supply is connected to the infusion pump. The processor also prompts the operator to confirm the pressure change if the pressure change signal is not detected within a predetermined time period. However, use of an operator-induced pressure change is not fail-proof. An operator may enter incorrect pressure values or connect the wrong drug supply with a correct pressure signal. A fail-proof system is needed to eliminate a possibility of operator errors.
[0031] U.S. Pat. No. 7,212,863 by Strandberg uses a test magnet in a specified time period for external activation of an implantable medical device, which can be externally programmed within the specified time period. When the magnet is taken away the implant device returns to the normal mode of operation. The use of test magnets is a simple means of external control of the operation of an implant device without involving a complex programmable external controller. The method of using an external test magnet for activating an internal device is incorporated by reference.
[0032] On programming features, U.S. Pat. No. 6,381,496 by Meadows, et al. provides context switching features for changing the operational parameters of an implantable device. These features enable a patient to change the current set of operational parameters to another set of operational parameters. The ability to change the current operational parameter set (OPS) is accomplished by including memory circuitry within the implant device wherein a plurality of OPS's are stored. An OPS setting can be manually activated and transmitted to the implant device to replace the current OPS. The patent provides programmable features for changing operational parameter settings, but it does not address refill steps and failsafe features.
[0033] U.S. Pat. No. 5,814,015 by Gargano, et al. uses a software warning as a failsafe measure for preventing the infusion of a wrong drug. A processor driven syringe pump for two syringes in a housing unit is suspended from an N pole. Its software provides a number of feedback warnings and alarms. The syringe plunger is driven into the syringe barrel by a motor operated by a failsafe feature against a short circuit in a drive circuit element feeding continuous current into the pump motor. A pusher assembly for the syringe includes a split nut that can be rotated and released to enable proper positioning of the syringe. The two pumps are jointly programmable and operable to allow the automatic stopping of a first pump and starting of a second pump for extended sequential infusion. Although the warnings and the failsafe feature are provided by the software against a short circuit they do not guarantee prevention of the infusion of the wrong drug. An ideal failsafe feature should provide a means for automatically preventing the refilling of a drug chamber with an incorrect drug.
[0034] On drive means for imparting a piston or plunger motion a pump device, a piezoelectric motor driven by electric pulses can be used. U.S. Pat. No. 6,940,209 by Henderson provides a piezoelectric lead screw motor for driving an assembly that contains a threaded shaft and a threaded nut. Subjecting the threaded nut to piezoelectric vibrations causes the threaded shaft to simultaneously rotate and translate in the axial direction. A drive product based on the concept called Squiggle motor has been commercialized. The SQUIGGLE SQ-306 model is 10 mm in length and 4 mm in diameter, and achieves precision levels in the micron range. The motor's power efficiency enables long battery life, which is a critical factor for implanted medical devices. Its motor driver board including ASIC, resonant inductors, Boost circuit and FWID diode can be packaged into 10 mm×10 mm×1.5 mm size. The use of commercially available SQUIGGLE motor is incorporated by reference.
[0035] US Patent Application 20080108862 by Jordan: Alain et al. describes an implantable device comprising a stepper motor for driving with an oscillator and an external controller for monitoring and correction of the performance of the device by passive telemetry. The displacement of the actuator is proportional to the number of pulses given to the motor coils. The method requires the use of an antenna coil coupled with a RF-to-DC converter to convert received RF energy to a DC voltage. However, the antenna coil and the converter add to the size of an implantable pump. The use of stepper motor as a drive means is incorporated by reference.
[0036] Alternatively, a piston or a plunger in a pump device can be driven by induction coils. U.S. Pat. No. 7,331,654 by Horsnell, et al. provides a solenoid valve mechanism using induction coils for controlling the flow of fluid through the valve. The valve mechanism includes a plunger member for axial reciprocation within a tubular member supporting an electric coil for generating a magnetic field when an electric current passes through the coil. The plunger is made of an electromagnetic material and can be magnetized by a magnetic field. The reciprocating motion of the plunger is adapted to open or close a nozzle orifice for injecting fluid drops on demand, such as on ink jet printer applications. The patent provides an example of using induction coils for driving plunger movements for dispensing fluid. The use of induction coils as a drive means is incorporated by reference.
[0037] With the limitations of the current implantable infusion pump technology, it is an objective of the present invention to prevent clogging at the catheter exit and the creation of a partial vacuum inside the delivery device. It is an objective to provide a failsafe refilling process and an automatic notification feature for the patient to take timely action. Additionally, it is another objective to provide a drug chamber configuration to enable dispensing of minute precise drug volumes at high frequency or at a continuous mode. It is another objective to provide a compact drug delivery device to dispense two drugs without mis-matching during the refilling process.
SUMMARY OF INVENTION
[0038] The present invention includes three drug delivery device configurations. The first is a single drug chamber configuration. The second is a divided drug chamber configuration. And the third is a compact dual-drug configuration that can dispense two drugs independently.
[0039] An implantable single-drug delivery pump device of this invention comprises a first chamber attached with a catheter and containing a drug fluid, a second chamber containing a filler fluid, and a piston separating the drug fluid and the filler fluid. The filler fluid, which is inert to the drug fluid, is partially enclosed by a collapsible wall. The collapsible wall, which is represented by bellow wall, enables the filler fluid to follow the movement of the piston in filling in the space in the first chamber vacated by dispensing of the drug fluid. For positive-closing at the dispensing opening, a slit valve is attached to the catheter. The slit valve closes upon retraction of the piston. The piston is controlled by a driver means for undergoing small reciprocating motion at predetermined amplitude which does not allow dispensing of the drug but does prevent clogging at the slit valve.
[0040] The implant pump is refillable. The positioning of a syringe needle can be facilitated by the attraction between a first magnet mounted on the septum of the pump device and a magnet attached to the needle. The refill syringe is of a passage type without having an active plunger.
[0041] With the needle inserted, the retraction or backward movement of the piston draws the refill fluid from the syringe into the first chamber. Continuous retraction of the piston draws in the drug fluid from the syringe to fill the first chamber while the catheter entrance remains closed by a negative pressure drop developed in the filling process.
[0042] The refilling process starts when an activation detector is activated. The two-way movement of the piston is controlled to enable repeated opening and closing motions of the slit valve with a specified amplitude and frequency for preventing clogging without dispensing the drug.
[0043] For verification of the pump performance the piston is attached with a second magnet to enable measurement of the distance between the first magnet and the second magnet by an external magnetic proximity sensor positioned across the skin. The piston can be driven by a piezoelectric motor or a stepper motor with the use of a threaded rod for achieving linear displacement of the piston. Such a driver means is controlled by a microprocessor and powered by an implantable battery contained inside the pump device. Alternatively, a piston can be made of ferrite material for magnetization by induction coils installed in the pump housing. The induction coils may be powered and controlled by an external controller.
[0044] The control software in the microprocessor controller is programmed to provide Dispensing Mode, Refilling Mode, Notification Mode and Verification-Calibration Mode.
[0045] An alternative implantable single-drug delivery device includes a divided drug chamber having a reciprocating piston and a follower for intermittent dispensing of drug dosages and a failsafe needle-activation feature for automatic refilling of the drug chamber. Also provided are a bellows-type and a soft-layer-type filler-fluid chamber containing an inert fluid to fill the space evacuated by the movement of the piston and the follower to prevent forming a partial vacuum in the fluid chambers enabling reliable performance of the device.
[0046] A drug delivery device of the divided drug chamber configuration comprises a divided internal fluid chamber containing a first fluid and an external fluid chamber containing a second fluid that is enclosed partially by collapsible soft-layered walls. The internal fluid chamber is divided into a first compartment and a second compartment by a wall mounted with a one-way valve. The first compartment has a piston connected to a driving means and the second compartment has a follower, which is in communication with the movement of the piston. The second fluid in the external chamber serves as a filler fluid in communication with the internal fluid chamber for filling the spaces behind the piston and the follower. Both the piston and the follower separate the second fluid from the first fluid.
[0047] The piston performs a reciprocating motion under the control of a motor driver which is preprogrammed. The piston is preferably driven by a high-resolution piezoelectric motor for a minimal advancement in the micrometer range per step. With a miniature piston size, the drug volume may be dispensed in the nano-liter range per piston step. During the forward motion of the piston the one-way valve is forced to close and the slit-valve at the end of the catheter is forced to open to dispense the drug fluid. During the backward motion of the piston a partial vacuum is created in the first compartment that causes the one-way valve to open and allow the drug fluid from the second compartment to enter the first compartment. Simultaneously, the forward and backward movements of the piston and the follower cause the filler fluid to flow in or out, respectively, from the spaces behind the piston and the follower. When the drug fluid is completely dispensed, the back spaces of the piston and the follower are full of the filler fluid.
[0048] Refilling of the first chamber is accomplished by inserting a refill container into the septum of the device to force the one-way valve to contact the opposing catheter wall, causing the attached electrode elements to activate the reciprocating motion of the piston. The reciprocating motion draws in the refill fluid to fill both the first compartment and the second compartment while the catheter entrance remains closed by the one-way valve. Similarly, a small reciprocating motion may be performed without dispensing drug fluid after the piston is retracted a predetermined distance enabling refill and battery low notifications.
[0049] An implantable dual drug delivery system of this invention features two drug chambers and the use of self-locking refill containers for failsafe refilling of drug fluids in the device.
[0050] A self-locking refill container utilizes a movable magnet valve and an orifice plate for locking and unlocking the flow of drug fluid inside the container reservoir. For a matched refill container, the polarity of its magnet valve creates an attraction force toward the magnet on the septum of the drug chamber. The attraction force moves the magnet valve away from the orifice plate to enable the flow of the drug fluid from the refill container reservoir into the drug chamber. For a mis-matched container, the polarity of the magnet valve creates a repelling force away from the magnet on the septum such that the magnet valve is moved to contact the orifice plate and block the drug flow.
[0051] Specifically a dual drug delivery device of the present invention has a first drug chamber containing a first drug fluid, a second drug chamber containing a second drug fluid and an external filler fluid chamber containing filler fluid. Each drug chamber is divided by a wall having a one-way valve into a first compartment and a second compartment. Each first compartment has a piston connected to a drive means and each second compartment has a follower, which is in flow communication with the movement of the piston. A small reciprocating motion may be performed without dispensing drug fluid after the piston is retracted for a predetermined distance for refill and battery low notifications.
[0052] The filler fluid chamber is attached externally to the drug chambers and it contains a filler fluid enclosed by collapsible soft layers. The filler fluid is for filling the space left by the movements of the pistons and the followers to prevent a partial vacuum inside the drug chambers that would hinder the movements of the pistons.
DESCRIPTION OF THE DRAWINGS
[0053] FIG. 1 a is a front cross-section view of an implantable drug delivery pump device using a piezoelectric motor with a drug reservoir at full state.
[0054] FIG. 1 b is a front cross-section view of the implantable drug delivery pump device of FIG. 1 a with the drug reservoir at empty state.
[0055] FIG. 2 a is a side cross-section view of a refill container of the present invention using a slidable disc.
[0056] FIG. 2 b is a side cross-section view showing insertion of the refill container needle of FIG. 2 a into the implantable drug delivery pump device of FIG. 1 a.
[0057] FIG. 2 c is a side cross-section view of a refill container of the present invention showing a collapsible bag at expanded full state.
[0058] FIG. 2 d is a side cross-section view of a refill container of FIG. 2 c showing the collapsible bag at a collapsed state.
[0059] FIG. 3 is a front cross-section view of an implantable drug delivery pump device using a stepper motor.
[0060] FIG. 4 a is a cross section view of an implantable drug delivery pump device using induction coils with the drug reservoir at full state.
[0061] FIG. 4 b is a cross section view of an implantable drug delivery pump device of FIG. 4 a using an external controller for refilling.
[0062] FIG. 5 is a control chart of operation modes of an implantable drug delivery pump device of the present invention.
[0063] FIG. 6 a is a front cross-section view of an implantable drug delivery device having a divided drug reservoir and a bellows-type filler-fluid chamber.
[0064] FIG. 6 b is a top cross-section view of FIG. 6 a showing cross-section areas of the first and the second fluid compartments.
[0065] FIG. 6 c is a side cross-section view of the implantable drug delivery device of FIG. 6 a showing a one-way check valve.
[0066] FIG. 7 a is an enlarged cross-section view of a flap-type one-way valve of FIG. 6 c with a refill container needle.
[0067] FIG. 7 b is an isometric exposed view of FIG. 7 a.
[0068] FIG. 7 c is an enlarged cross-section view of a plunger-type one-way valve not touched by a refill container needle.
[0069] FIG. 7 d shows the plunger-type one-way valve of FIG. 7 c being pushed by the needle of the refill container against the electrode plate on the catheter wall blocking the flow channel.
[0070] FIG. 8 a is a side cross-section view of the implantable drug delivery device of FIG. 6 c showing the second compartment of the drug reservoir full with first fluid.
[0071] FIG. 8 b shows the implantable drug delivery device of FIG. 8 a with the second compartment of the drug reservoir full with filler fluid.
[0072] FIG. 8 c shows the implantable drug delivery pump device of FIG. 8 b with a refill container needle inserted and pressing against a contact switch.
[0073] FIG. 8 d shows the implantable drug delivery pump device of FIG. 8 b with a refill container needle being removed from the one-way valve in the drug reservoir.
[0074] FIG. 9 a is a front cross-section view of an implantable drug delivery device attached with a softlayer filler-fluid chamber.
[0075] FIG. 9 b is a side cross-section view of the implantable drug delivery device of FIG. 9 a showing soft-layer filler-fluid chamber attached to the housing wall of the device.
[0076] FIG. 9 c is a B-B cross-section of FIG. 9 b showing flow gaps for filler fluid on housing walls.
[0077] FIG. 10 a is a side cross-section view of the implantable drug delivery device of FIG. 9 b showing the second compartment of the drug reservoir at full state.
[0078] FIG. 10 b shows the implantable drug delivery device of FIG. 10 a with the second compartment of the drug reservoir full of filler fluid.
[0079] FIG. 10 c shows the implantable drug delivery device of FIG. 10 b with a refill container needle inserted and pressing against a contact switch.
[0080] FIG. 10 d shows the implantable drug delivery device of FIG. 10 c with a refill container needle being removed at completion of refilling.
[0081] FIG. 11 is a control chart of operation modes of an implant infusion device of the present invention.
[0082] FIG. 12 a is a front cross-section view of an implantable dual drug delivery device with two dispensing valves at opposite sides of the device.
[0083] FIG. 12 b is a top cross-section view A-A of FIG. 12 a.
[0084] FIG. 12 c is a side cross-section view of the implantable infusion dual drug delivery device of FIG. 12 a.
[0085] FIG. 13 is an enlarged cross-section view of the one-way valve of FIG. 12 c with a refill container needle inserted.
[0086] FIG. 14 a is a side cross-section view of the implantable dual drug delivery device as shown in FIG. 12 c indicating the second compartment of the first drug reservoir full with first fluid.
[0087] FIG. 14 b shows the implantable dual drug delivery device of FIG. 13 a with the second compartment of the first drug reservoir full with the filler fluid.
[0088] FIG. 14 c shows the implantable dual drug delivery device of FIG. 13 b with a refill container needle inserted and pressing against a contact switch in the first catheter.
[0089] FIG. 14 d shows the implantable dual drug delivery device of FIG. 13 b with a refill container needle being removed from the one-way valve in the first drug reservoir.
[0090] FIG. 15 a shows refill container of Drug A unlocked internally with matched septum of Drug A.
[0091] FIG. 15 b shows refill container of Drug B locked internally due to mix-matching with the septum of Drug A.
[0092] FIG. 16 a is an implantable dual drug delivery device of FIG. 15 b with the refill container of Drug A unlocked internally when inserted into the septum of Drug A.
[0093] FIG. 16 b is an implantable dual drug delivery device of FIG. 16 a with the spent refill container removed from the septum upon completion of refilling.
[0094] FIG. 17 a is an implantable dual drug device of FIG. 16 a with the refill container of Drug A internally locked as inserted into the septum of Drug B.
[0095] FIG. 17 b is an implantable dual drug delivery device of FIG. 17 a with the refill container of Drug B unlocked internally when inserted into the septum of Drug B.
[0096] FIG. 17 c is an implantable dual drug delivery device of FIG. 17 b with the spent refill container removed from the septum upon completion of refilling.
[0097] FIG. 18 a is a front cross-section view of an implantable dual drug delivery device with two drug chambers oriented in the same direction.
[0098] FIG. 18 b is a cross-section view A-A of FIG. 18 a.
[0099] FIG. 19 is a control chart of operation modes of an implantable dual drug delivery device of the present invention
DESCRIPTION OF THE INVENTION
[0100] In the following descriptions, implantable drug delivery pump device and infusion pump are used interchangeably. First fluid and drug fluid are used interchangeably. Second fluid and filler fluid are used interchangeably. First chamber, drug chamber and drug reservoir are used interchangeably. Second chamber and filler fluid chamber are used interchangeably.
[0101] Further, the present invention relates to
[0102] 1. An implantable drug delivery device comprising;
[0103] a. housing walls,
[0104] b. a first chamber supported by the housing walls having an outlet and containing a first fluid,
[0105] c. a piston positioned inside said first chamber, being driven in forward and backward motions by a drive means, said piston moves the first fluid toward the outlet when being driven forward by a diver means,
[0106] d. a second chamber having a collapsible wall containing a second fluid, said second fluid being separated from the first fluid by said piston, said collapsible wall collapses as the second fluid moves in with said piston in response to the reduced volume of the first fluid in the first chamber.
[0107] e. a drive means for imparting motion of the piston.
[0108] 2. An implantable drug delivery device of [1] wherein said housing walls and the collapsible wall are impermeable.
[0109] 3. An implantable drug delivery device of [1] wherein said collapsible wall contracts as the second fluid moves in with said piston during the dispensing of the first fluid and said collapsible wall expands as the second fluid moves back with said piston when the first chamber is refilled with the first fluid.
[0110] 4. An implantable drug delivery device comprising:
[0111] a. housing walls,
[0112] b. a first chamber supported by the housing walls having an outlet and containing a first fluid,
[0113] c. a piston positioned inside said first chamber, being driven in forward and backward motions by a drive means, said piston moves the first fluid toward the outlet when being driven forward by the diver means,
[0114] d. a catheter having a base end and a dispensing end, said base end being attached to the outlet,
[0115] e. a positive-closing valve being attached to the dispensing end of said catheter. said positive-closing valve opens when the piston moves toward the outlet and closes when the piston moves away from the outlet,
[0116] f. a septum being attached to the outlet, said septum being in flow communication with said first chamber and said catheter,
[0117] g. a drive means for imparting motion of said piston.
[0118] 5. An implantable drug delivery device of [4], wherein said positive-closing valve is a slit valve of a cap of elastomeric materials having a cross-slit cut at the apex of the cap forming a plurality of flexible flappers, said slit valve being at a closed position when no pumping pressure is exerted by the piston.
[0119] 6. A process for preventing clogging of the positive-closing valve of an implantable drug delivery device of [4] wherein said drive means being controlled by a microprocessor, said microprocessor being programmed to move the piston forward a first distance for dispensing the first fluid and then to move the piston backward a second distance to ensure the closing of the self-sealing valve, said first distance being larger than the second distance by a value corresponding to a specified amount of the first fluid being dispensed.
[0120] 7. A process for preventing clogging of the dispensing end of an implantable drug delivery device of [6] wherein said microprocessor provides repeated motions of opening and closing of the positive-closing valve by moving the piston forward and backward with a specified frequency and a specified amplitude that is incapable of dispensing the first fluid.
[0121] 8. A process for refilling an implantable drug delivery device of [4] comprising the steps of:
[0122] a. signaling a need to refill the first chamber by using the oscillation motion of said piston with a detectable amplitude and frequency,
[0123] b. inserting the needle of a refill container containing the first fluid into said septum,
[0124] c. retracting the piston away from the outlet by the drive means forcing the positive-closing valve to the closed position and resulting in withdrawing the refill fluid from the syringe into the first chamber.
[0125] 9. An implantable drug delivery device of [4] including a second chamber which has a collapsible wall containing a second fluid. said second fluid being separated from the first fluid by said piston, said collapsible wall contracts as the second fluid moves in with said piston in response to the reduced volume of the first fluid in the first chamber.
[0126] 10. An implantable drug delivery device comprising;
[0127] a. housing walls,
[0128] b. a first chamber supported by the housing walls having an outlet and containing a first fluid,
[0129] c. a piston positioned inside said first chamber and being driven in forward and backward motions by a drive means, said piston moves the first fluid toward the outlet when being driven forward by a diver means,
[0130] d. a septum, attached to the outlet, said septum being in flow communication with said first chamber and said catheter,
[0131] e. a first magnet attached to said septum and a second magnet attached to said piston,
[0132] f. a drive means for imparting motion to the piston,
[0133] g. an IC control board supported by the housing walls, said IC control board includes a microprocessor, electrical circuits and is in communication with said drive means,
[0134] h. an activation detector in communication with said first magnet and an electrical circuit in the IC control board that converts a change of magnetic field surrounding the first magnet into a voltage output.
[0135] 11. An implantable drug deliver) device of [10] wherein said electrical circuit comprises Wheatstone bridge elements to convert the magnetic field into a voltage output for measuring the distance between the first magnet and the second magnet.
[0136] 12. An implantable drug delivery device of [10] including a second chamber which has a collapsible wall containing a second fluid, said second fluid being separated from the first fluid by said piston, said collapsible wall contracts as the second fluid moves in with said piston in response to the reduced volume of the first fluid in the first chamber.
[0137] 13. An implantable drug delivery device of [10] including a slit valve which is attached to the dispensing end of said catheter, said slit valve opens when the piston moves toward the outlet and closes when the piston moves away from the outlet.
[0138] 14. An implantable drug delivery device of [10] including a second magnet which is attached to said piston and the distance between the first magnet and the second magnet being measurable by a magnet proximity sensor to determine the position of said piston in the first chamber.
[0139] 15. An implantable drug delivery device of [10] in which flow gaps being created between the motor and the housing walls for the flow of the second fluid from the second chamber to the space behind the piston in the first chamber.
[0140] 16. An implantable drug delivery device of [1], [4] or [10] wherein said drive means is a threaded rod and a motor imparting the rotation of the threaded rod, which causes forward and backward movements of the piston in the axial direction of the threaded rod corresponding to rotational directions of the motor.
[0141] 17. An implantable drug delivery device of [16] wherein said motor is a piezoelectric motor or a stepper motor.
[0142] 18. An implantable drug delivery device of [1] or [4] wherein said piston is made of ferrite material and said drive means comprising a permanent magnet positioned at the outlet end of the first chamber and a set of induction coils being supported by the housing walls, said induction coils magnetizing the piston to move in forward and backward directions depending on the polarity of the magnetic field induced by the induction coils responding to directions of electrical current imposed on the induction coils.
[0143] 19. An implantable drug delivery device of [18] wherein said induction coils are controlled by an external controller using telemetry to monitor and change the operational parameters of said induction coils.
[0144] 20. An implantable drug delivery device of [1] or [4] including an IC control board in electrical communication with the drive means.
[0145] 21. An implantable drug delivery device of [20] including a battery in electrical communication with the IC control board.
[0146] 22. An implantable drug delivery device of [18] wherein said piston moves toward the outlet position when the piston is magnetized with a polarity in the same polarity direction of the permanent magnet, and said piston moves away from the outlet position when said piston being magnetized with polarity in the opposite polarity direction of the permanent magnet.
[0147] 23. An implantable drug delivery device of [17] wherein said piezoelectric motor has a threaded rod which is in free-to-rotate engagement with said piston, said piston having a non-circular cross-section undergoing linear movement without rotation.
[0148] 24. An implantable drug delivery device of [17] wherein said stepper motor having a threaded shaft, said piston having non-circular cross-section and inner threads which are engaged with the threaded shaft, said piston moves in the axial direction of the threaded shaft when the stepper motor is activated.
[0149] 25. A refill container for refilling an implantable drug delivery device comprising:
[0150] a. a tubular housing with inner wall surface having first opening and second opening, said tubular housing containing a drug fluid,
[0151] b. a needle being attached to the second opening and being in flow communication with the drug fluid,
[0152] c. a disc situated inside said tubular housing being in slidable sealing fit with inner wall surface, said disc not accessible from outside the housing and being only movable following the flow direction toward the needle when the drug fluid being drawing out of the housing through the needle, said disc being exposing to ambient pressure through the first opening.
[0153] 26. A refill container for refilling an implantable drug delivery device comprising:
[0154] a. a collapsible pouch containing a drug fluid having flexible film wall fastened to a top plate having an exit opening, said film wall being collapsible when the drug fluid is drawn through the exit opening,
[0155] b. a needle being attached to the exit opening of the top plate and being in flow communication with the drug fluid.
[0156] 27. A refill container for refilling an implantable drug delivery device of [26] including an external tubular housing wall, separate from the collapsible pouch and forming a gap between the external housing wall and the flexible film wall of said collapsible pouch, said gap preventing the pouch from being collapsed by a deflection of the housing wall causing dispensing of drug fluid.
[0157] 28. A refill container for refilling an implantable drug delivery device of [26] including an external tubular housing wall, whose deflection does not cause contraction of said collapsible pouch and forcing the dispensing of the drug fluid.
[0158] 29. A refill container for refilling an implantable drug delivery device of [25], [26], [27] or [28] including an attached magnet surrounding the needle.
[0159] 30. An implantable drug delivery device comprising;
[0160] a. housing walls,
[0161] b. an internal fluid chamber, containing a first fluid, is supported by housing walls and is divided into a first compartment and a second compartment by a wall having a one-way valve, the first compartment having an outlet and a piston and the second compartment having a follower which is in communication with the movement of the piston,
[0162] c. an external fluid chamber containing a second fluid is supported by housing walls and is enclosed partially by a collapsible wall, said second fluid being separated from the first fluid by the piston and the follower, said collapsible wall contracts as the second fluid moves in with said piston in respond to the reduced volume of the first fluid in the first chamber.
[0163] d. a drive means for imparting forward and backward movements of the piston, said forward movement for moving the first fluid toward the outlet and said backward movement for moving the first fluid away from the outlet.
[0164] 31. An implantable drug delivery device of [30] wherein the forward movement of said piston causes the contraction of the collapsible wall and the backward movement of said piston causes the expansion of the collapsible wall.
[0165] 32. An implantable drug delivery device of [30] wherein said walls of the internal chamber and the external chamber are impermeable to fluids present in an operating environment.
[0166] 33. An implantable drug delivery device of [30] wherein said one-way valve closes when the piston moves toward the outlet and the one-way valve opens when the piston moves away from the outlet causing the first fluid to flow from the second compartment into the first compartment.
[0167] 34. An implantable drug delivery device system comprising:
[0168] a. a refill container comprising housing walls, a reservoir containing first fluid and a needle,
[0169] b. an internal fluid chamber containing first fluid, said internal fluid chamber being divided by a wall having a one-way valve into a first compartment having a piston and a second compartment having a follower,
[0170] c. an outlet having opposing walls forming a flow channel in communication with said first compartment, said opposing walls can be forced to contact each other to block the flow of the first fluid by insertion of the needle of said refill container.
[0171] d. a drive means for imparting motion of the piston.
[0172] 35. An implantable drug delivery device system of [34] having an external fluid chamber, containing a second fluid which is enclosed partially by collapsible walls, said second fluid being separated from said first fluid by the piston and the follower and fills the space left by the movements of the piston and the follower.
[0173] 36. An implantable drug delivery pump device system of [34] having a septum attached with a first magnet for positioning the needle of the refill container for insertion into the septum.
[0174] 37. An implantable drug delivery device system of [34] wherein said outlet is attached with a catheter having a positive closing valve mounted at the dispensing tip, said valve opens when the piston moves toward the outlet and closes when the piston moves away from the outlet.
[0175] 38. An implantable drug delivery device system of [34] wherein the first fluid in said refill container is drawn into the internal fluid chamber by moving the piston away from the outlet.
[0176] 39. An implantable drug delivery device system comprising:
[0177] a. a refill container comprising housing walls, a reservoir containing a refill fluid and a needle,
[0178] b. an internal chamber containing a first fluid and having an outlet and a piston, said outlet having opposing walls forming a flow channel for the flow of the first fluid,
[0179] c. a septum being attached to the outlet of said internal chamber, said septum having a plunger for being pushed by the needle of said refill container to block the flow channel of the outlet.
[0180] 40. An implantable drug delivery device system comprising:
[0181] a. a refill container comprising housing walls, a reservoir containing a refill fluid and a needle,
[0182] b. an internal chamber containing a first fluid and having an outlet and a piston, said outlet having opposing walls forming a flow channel for the flow of the first fluid,
[0183] c. a drive means for imparting forward and backward movements of the piston, said forward movement for moving the first fluid toward the outlet and said backward movement for moving the first fluid away from the outlet.
[0184] d. a contact switch in electrical communication with said drive means, said contact switch being activated by the insertion of the needle of said refill container activating the movement of the piston.
[0185] 41. An implantable drug delivery device system of [40] wherein said contact switch having opposing electrode plates with each electrode plate being attached to said opposing walls of said outlet, and said opposing walls can be forced to contact each other thereby blocking the flow of the first fluid through the outlet, and said movement of the piston causing the flow of the first fluid from the refill container to the internal fluid chamber.
[0186] 42. An implantable drug delivery device system of [40] wherein said contact switch being formed by a stationary electrode plate and a movable electrode plate, said movable electrode plate being attached to a plunger which is spring loaded against a partition wall dividing a piston chamber and a reservoir chamber.
[0187] 43. An implantable drug delivery device system of [40] having an external fluid chamber containing a second fluid that is enclosed partially by collapsible walls, said second fluid being separated from said first fluid by the piston and fills the space left by the movement of the piston.
[0188] 44. An implantable drug delivery device system of [40] having a septum attached with a first magnet for positioning the refill container for insertion into the septum.
[0189] 45. An implantable drug delivery device system of [40] wherein the first fluid in said refill container being drawn into the internal fluid chamber by moving the piston away from the outlet.
[0190] 46. An implantable drug delivery device of [30], [34] or [40] wherein said drive means is a threaded rod and a motor imparting the rotation of the threaded rod, which causes forward and backward movements of the piston in the axial direction of the threaded rod corresponding to the rotational direction of the motor.
[0191] 47. An implantable drug delivery device of [30], [34] or [40] wherein said motor is a piezoelectric motor comprising a threaded rod and piezoelectric plates with one end forming a threaded-nut configuration and, said threaded rod rotates when said piezoelectric plates being in piezoelectric vibration.
[0192] 48. An implantable drug delivery device of [30], [34] or [40] wherein said internal fluid chamber having two parallel sidewalls and one of said sidewalls is attached with said external fluid chamber having said collapsible walls containing the second fluid, which fills the space left by the movements of the piston and the follower.
[0193] 49. A process of ensuring positive-closing of the slit valve of an implantable drug delivery device of [30], [34] or [40] wherein said drive means is controlled by a microprocessor, said microprocessor being programmed to move the piston forward for a first distance to dispense the first fluid and then to move the piston backward for a second distance to ensure the closing of the self-sealing valve, said first distance being larger than the second distance by a value corresponding to a specified amount of the first fluid being dispensed.
[0194] 50. A process of refilling an implantable drug delivery device of [30], [34] or [40] comprising steps of:
[0195] a. inserting a refill container containing first fluid into said septum,
[0196] b. retracting the piston away from the outlet by the drive means resulting in withdrawing the refill fluid from the refill container into the first chamber.
[0197] 51. A process for refilling an implantable drug delivery device of [50] wherein the refill container is of the passive type having no plunger for manually injecting first fluid into said first chamber.
[0198] 52. A process of refilling an implantable drug delivery device of [50] or [51] including a step of signaling a need to refill the first chamber by using the reciprocating motion of said piston with a detectable amplitude and frequency,
[0199] 53. A process of verifying the movement of a follower in a drug chamber of an implantable drug delivery device of [36] and [44] including a second magnet being attached to the follower and measuring the distance between the second magnet and the first ring magnet at the septum by a magnet proximity sensor.
[0200] 54. An implantable drug delivery device comprising a drug fluid chamber, a reciprocating piston and a battery for powering the reciprocating motion of the piston, said battery having a batterylow circuit and said piston being programmed to perform the reciprocating motion at detectable amplitude and frequency as a notification for battery recharge or replacement upon receiving a battery low signal from the battery-low circuit.
[0201] 55. An implantable drug delivery device of [54] wherein said piston is retracted for a predetermined distance and driven for said reciprocating motion without dispensing the drug fluid.
[0202] 56. An implantable drug delivery device of [54] or [55] having a positive-closing valve attached to said drug fluid chamber, said positive-closing valve remaining at closed position when the piston is retracted for said distance and performing said reciprocating motion.
[0203] 57. An implantable dual drug delivery device comprising:
[0204] a. a first drug chamber containing a first drug fluid and having a first outlet, a septum and a first piston,
[0205] b. a first magnet having a first polarity attached to the septum of said first drug chamber,
[0206] c. a second drug chamber containing a second drug fluid and having a second outlet, a septum and a second piston,
[0207] d. a second magnet having a second polarity attached to the septum of said second drug chamber, the second polarity being opposite to the first magnet polarity,
[0208] 58. An implantable dual drug delivery device of [57] including an external chamber, said external chamber containing a third fluid enclosed partially by a collapsible soft layer, said third fluid being separated from the first drug fluid and the second drug fluid by the first piston and the second piston.
[0209] 59. An implantable dual drug delivery device of [57] wherein said first and second magnets are ring magnets.
[0210] 60. An implantable dual drug delivery device of [57] wherein the first piston is driven by a first motor and the second piston is driven by a second motor.
[0211] 61. An implantable dual drug delivery device comprising:
[0212] a. a first drug chamber containing first drug fluid, said first drug fluid chamber being divided by a wall having a one-way valve into a first compartment having a piston and a second compartment having a follower,
[0213] b. a second drug chamber containing second drug fluid, said second drug fluid chamber being divided by a wall having a one-way valve into a first compartment having a piston and a second compartment having a follower,
[0214] c. a first catheter and a first septum being attached to said first drug chamber, said first catheter having opposing walls forming a flow channel in communication with the first drug compartment, said opposing walls can be forced to contact each other to block the flow of the first drug fluid,
[0215] d. a second catheter and a second septum being attached to said second drug chamber, said second catheter having opposing walls forming a flow channel in communication with the second drug compartment, said opposing walls can be forced to contact each other to block the flow of the second drug fluid,
[0216] e. a first magnet having a first polarity being attached to the septum of said first drug chamber,
[0217] f. a second magnet having a second polarity being attached to the septumn of said second drug chamber, the second polarity being opposite to the first polarity.
[0218] 62. An implantable dual drug delivery device of [61] having an external chamber containing a third fluid, enclosed partially by a collapsible soft layer, said third fluid being separated from the first drug fluid and the second drug fluid by the pistons and the followers.
[0219] 63. A refill container for refilling an implantable dual drug delivery device comprising:
[0220] a. a tubular housing wall containing a drug fluid, said tubular housing having a valve chamber with a top opening end and a reservoir chamber with a bottom enclosed end,
[0221] b. a needle attached to the top opening end of the valve chamber,
[0222] c. an orifice plate being positioned separating the valve chamber and the reservoir chamber, said orifice plate having an orifice at the center for passing the drug fluid from the reservoir chamber to the valve chamber.
[0223] d. a magnet valve having a polarity and being movably attached to the valve chamber, said magnet valve blocks the opening of the orifice plate when moved in contact with the orifice plate
[0224] and allows for the flow from the reservoir chamber to the needle when said magnet valve is moved away from the orifice plate.
[0225] 64. A refill container for refilling an implantable dual drug delivery device of [63] wherein said magnet valve having a platform including a central solid area and slot openings, said central solid area capable of blocking the orifice of the orifice plate and said slot openings are blocked by said orifice plate when said magnet valve is moved in contact with the orifice plate.
[0226] 65. An implantable dual drug delivery device and refill system comprising:
[0227] a. a first refill container containing a first drug fluid having a ring magnet valve with a first polarity,
[0228] b. a second refill container containing a second drug fluid having a ring magnet valve with a second polarity,
[0229] c. a first drug chamber containing a first drug fluid and having an outlet, a septum and a first piston, said septum being attached with a first magnet with first polarity attracting the ring magnet valve of the first refill container,
[0230] d. a second drug chamber containing a second drug fluid and having an outlet, a septum and a second piston, said septum being attached with a second magnet with second polarity attracting the magnet valve of the second refill container, said second polarity being opposite to the first polarity of said first refill container.
[0231] 66. An implantable dual drug delivery device and refill system of [65] wherein the first ring magnet of said first drug chamber repels the magnet valve of the second refill container thereby blocking the drug flow inside the second refill container.
[0232] 67. An implantable dual drug delivery device and refill system of [57] or [65] wherein the first piston is driven by a first motor and the second piston is driven by a second motor.
[0233] 68. An implantable dual drug delivery device of [67] including an external chamber, said external chamber containing a third fluid enclosed partially by a collapsible soft layer, said third fluid being separated from the first drug fluid and the second drug fluid by the first piston and the second piston.
[0234] 69. An implantable dual drug delivery device and refill system of [57] or [67] wherein the outlet of each drug chamber is attached with a catheter with a slit valve mounted at the dispensing tip, said slit valve opens when the piston in each drug chamber moves toward the outlet and closes when the piston moves away from the outlet.
[0235] 70. An implantable dual drug delivery device and refill system of [57] or [67] wherein the drug fluid in each refill container is drawn into a matched drug chamber by moving the piston away from the outlet.
[0236] 71. An implantable dual drug delivery device and refill system of [69] wherein the outlet of each drug chamber having opposing walls forming a flow channel in communication with the drug fluid in the chamber, said opposing walls can be forced to contact each other to block the flow into the catheter when activated by the needle of a refill container.
[0237] 72. An implantable dual drug delivery device and refill system of [61], [65] or [69] wherein each outlet has a contact switch, said contact switch having opposing electrode plates with each electrode plate being attached to said opposing walls of said outlet walls, and said opposing walls can be forced to contact each other to block the flow into the catheter and activate the movement of the piston when activated by the needle of said refill container causing the drug fluid to be drawn from the refill container to the drug chamber.
[0238] 73. An implantable dual drug delivery device of [57], [61] or [67] including a motor driver, a battery and an IC control board with control software, said motor driver controls the movements of the first and the second pistons through the control software of the IC control board and powered by the battery.
[0239] 74. An implantable dual drug delivery device of [57], [61] or [67] wherein each motor is a piezoelectric motor comprising a threaded rod and piezoelectric plates with one end forming a threaded-nut configuration and, said threaded rod rotates when said piezoelectric plates being in ultrasonic vibration.
[0240] 75. An implantable dual drug delivery device of [57], [61] or [65] wherein the two drug chambers are oriented in the same direction.
[0241] 76. An implantable dual drug delivery pump device of [57], [61] or [65] wherein the two drug chambers are oriented in opposite directions.
[0242] 77. A process of ensuring positive closing of the slit valve of the implantable dual drug delivery device of [73] wherein said motor driver with software control moves each piston forward for a first distance for dispensing the drug fluid and then to move the piston backward for a second distance to ensure the closing of the slit valve, said first distance being larger than the second distance by a value corresponding to a specified amount of the drug fluid being dispensed.
[0243] 78. A process to verify the movement of a follower in a drug chamber of an implantable dual drug delivery pump device of [61] including a follower magnet being attached to the follower and measuring the distance between the follower magnet and the septum magnet by a magnet proximity sensor for determining the position of said follower in the drug chamber.
[0244] 79. An implantable dual drug delivery device of [61] or [62] wherein said first magnet and second magnet are ring magnets
[0245] Single-Drug-Chamber Device Configuration
[0246] As shown in FIG. 1 a an implantable drug delivery pump device 10 of the present invention comprises a pump housing having walls 14 including two fluid chambers separated by a piston with the first chamber 18 as a reservoir containing first or drug fluid 20 , and the second chamber 22 containing second or filler fluid 24 which is enclosed partially by a collapsible wall 26 . Second fluid 24 is used as a filler fluid which is inert to the drug fluid and body tissues. Piston 28 prevents fluid communication between first chamber 18 and second chamber 22 . The piston is driven by a drive means, powered by battery 71 , for infusing the first fluid through outlet 34 and reducing the volume of the first fluid in the first chamber with the vacated space filled in by the filler fluid, which is accompanied by the collapsing of the collapsible wall. The fill-in motion of the filler fluid prevents creation of a vacuum that, if allowed to exist, can negatively impact the movement of the piston. In this configuration the walls of the first chamber containing the drug fluid are rigid with internal contact surfaces not hindering the movement of the piston. In addition, walls 51 and 56 of the first and the second chambers 18 and 22 , respectively, are impermeable to external fluids present in a body tissue environment. In particular, wall 51 of first chamber 18 is made of a drug-compatible, implantable material of sufficient rigidity without deformation so as not to hinder the movement of piston inside the reservoir chamber. For example, the wall material of the first chamber may be constructed from a metal, such as titanium, nickel titanium, stainless steel, anodized aluminum, or tantalum, or a plastic, such as polyethylene, nylon, or polyurethane. However, wall 56 of second chamber 22 is made of flexible material such as silicone, polyurethane, which allows the wall to expand or collapse as fluid is added or withdrawn from the first chamber into the second chamber. A bellow configuration 26 is illustrated in FIG. 1 a in representing the collapsible nature of the second chamber to enable the movement of the filler fluid in filling in the space reduced or vacated by the dispensing of the first fluid. Furthermore, a catheter 48 is attached to outlet 34 of first chamber 18 in flow communication with the first fluid 20 . The wall of the first chamber includes a filling septum 44 , which enables a physician to inject drugs into the drug chamber. An outlet valve in a form of slit valve 52 is attached at dispensing end of the catheter. A normally closed slit valve prevents backflow of fluids from the outside environment into the device. The slit valve is forced to open by the forward movement 60 of the piston exerting pumping pressure allowing the drug to be dosed from the reservoir to the treatment site. The implantable pump device is implanted into a body cavity, and the catheter can be led to an appropriate tissue or space for dispensing the drug.
[0247] Piston Motion
[0248] The first fluid 20 is pushed by the forward movement 60 of piston 28 . The piston performs forward and backward motions under the control of a motor driver, which is mounted in IC control board 32 and is preprogrammed. The perimeter surface of the piston is in sliding-sealing fit, represented by O-ring 61 , with the inner wall surface of the first chamber. During the forward motion of the piston the slit valve at the end of the catheter is forced to open to dispense the therapeutic liquid. As a result, the second fluid from the second chamber enters the first chamber through the flow gaps 64 to fill in the space behind the piston head left by the movement of the piston. The sliding-sealing fit or the wiping contact of the piston perimeter surface with the inner wall of the first chamber ensures no residual trace of drug fluid, i.e. the first fluid, left behind the piston in contact with the filler fluid, i.e. the second fluid, and similarly no residual trace of the filler fluid left on the opposite side of the piston will be in contact with the drug fluid.
[0249] The filling motion of the filler fluid into the first chamber reduces the volume in the second chamber, therefore, causes the bellow wall or the collapsible wall to close in. Conversely, a backward or retracting motion of the piston creates a negative pressure drop that causes the slit valve to close. With the slit valve closed, further retraction of the piston is hindered due to vacuum pressure created inside the first chamber. For a given drug dosage at each infusion event, the number of forward pulses and the immediate number of backward pulses can be predetermined for the device to provide the desired net amount of drug dispensed at the event through the slit valve. In each infusion event the number of forward pulses or forward distance is greater than the number of backward pulses or backward distance which results in the desirable amount of drug dosage exiting from the one-way slit valve at the dispensing end of the catheter. Moreover, the capability of the reciprocating motion of the piston can be utilized for refilling notification as will be described in later sections.
[0250] Slit Valve
[0251] In a preferred embodiment a positive-closing slit valve 52 is a molded dome-shaped cap of elastomeric materials having a cross-slit cut forming a plurality of flexible flappers. In a preferred embodiment a slit valve used for the implantable drug delivery pump device of this invention is of a biocompatible silicone material. The slit valve has a tubular wall base and four flappers. Each flapper is a curved triangular valve segment extending from the tubular wall base with the tip of each valve segment intercepting at the center, i.e. at the apex of the slit valve opening when the slit valve is at the closed position. Each valve segment can be bent like a cantilever beam under the pressure of a dispensing flow. The slit length, wall thickness and the elastic modulus of the valve material are designed to ensure self-closing of the slit valve by the resiliency and the vacuum force at the absence of pumping pressure. With the use of a slit-valve, it is not necessary to use an outlet check valve to prevent backflow.
[0252] The valve opens under positive piston pressure to dispense first fluid and the cross-slit valve closes under negative piston pressure when the piston is moved away from the outlet by the drive means. In practice, infusion of the drug is achieved in pulsed steps at predetermined time intervals. In each repeated infusion events, the therapeutic fluid is incrementally dispensed and the collapsible wall or the bellow wall is moving forward in each cycle. This process continues until the first chamber 18 , i.e. the drug reservoir, is depleted of the first or the drug fluid. As shown in FIG. 1 b , in the drug-spent or reservoir empty state the space 72 behind the piston in first chamber 18 is full of the filler fluid 24 . A dispensing phase starts from the piston home position 62 , which is defined as the piston top surface 63 in contact with the first fluid being at the lower travel limit of the piston, and ends when the piston's top surface is at the upper travel limit 66 .
[0253] Refilling
[0254] Referring to FIGS. 2 a and 2 b , refilling of the drug chamber can be accomplished by inserting a needle 80 of a refill container 84 into a septum 88 of the drug delivery pump device 10 . In one embodiment refill container 84 having drug fluid 71 comprises a tubular housing wall 89 having a first opening 86 and second opening 91 , disc 87 , magnet 96 and needle 80 . Disc 87 is in movable fit with the inner wall of housing 89 and the opening 89 maintains the disc at ambient pressure. To prevent external actuation, disc 87 is not accessible manually from outside housing 89 and it is only movable when following the flow direction toward the needle when the drug fluid is drawing out of the housing through the needle. Magnet 96 is preferably a ring magnet. Both magnet 96 and needle 80 are attached to housing wall 89 with the needle being attached to second opening 91 for the passage of drug fluid 71 . FIG. 2 a shows refill container 84 being full of refill drug fluid 71 . Magnet 96 surrounds the needle to guide the positioning of the needle when inserting to septum 88 which is attached with magnet 92 . In another embodiment, the refill container for an implantable drug delivery device of this present invention uses a collapsible pouch having a thin flexible wall for containing a drug fluid. No movable disc is required. FIG. 2 c shows a refill container assembly 184 using a rigid outer housing wall 189 to shield the collapsible pouch 188 . The thin flexible wall 187 of collapsible pouch 188 is fastened to a top plate 190 forming an enclosure containing drug fluid 171 . The top plate has exit opening 191 as a flow path for the drug fluid drawn out of the collapsible pouch. Needle 180 is attached to the exit opening 191 by threaded engagement between the needle and the housing. Alternatively, the needle may be directly threaded onto the top plate 190 of the pouch. FIGS. 2 c and 2 d illustrate the assembly housing comprising two foldable halves 150 and 152 for ease of inserting the collapsible pouch and mounting the needle. With this foldable configuration magnet ring 196 , which surrounds the needle, may be divided into two halves with each attached to a half of the housing wall. To prevent external ambient pressure from contracting the collapsible pouch and forcing out the drug fluid, the external housing wall 189 is designed to be rigid and not deformable to contact on the collapsible pouch. Optionally, gap 154 exits between the housing wall 189 , which is of tubular form, and the collapsible pouch 188 such that the housing wall does not deform preventing contraction of the collapsible pouch which would have resulted in inadvertent dispensing of the drug fluid. FIG. 2 d shows that collapsible pouch 188 contracts only when drug fluid 171 is drawn out from needle 180 under a vacuum 195 , which occurs during the refilling process when the needle is inserted into the septum of drug delivery device 10 . This passive type of refill container which depends on insertion into the septum of a drug delivery device for withdrawing the drug fluid is a safety feature to prevent inadvertent injection of the drug fluid into body tissues if the device is not properly connected to the septum.
[0255] For the insertion of a refill container needle, magnet 92 attached to septum 88 is preferably a raised ring for guiding the positioning of the needle through the skin 98 . The raised ring 92 may be in a form of ring magnet of a polarity that attracts a ring magnet 96 of opposite polarity mounted on the needle 80 of the refill container 84 . The attraction between the two magnets 92 and 96 across the skin can facilitate positioning and stabilizing the needle 80 during injection. PDMS, which is Polydimethylsiloxane a silicon-based organic polymer material, may be selected as a septum material for its flexibility and ability to reseal itself after repeated punctures via a needle attached to the refill container.
[0256] As a reverse of the dispensing function, the retraction or backward movement of the piston draws the refill fluid from the refill container into the first chamber. Continuous retracting motion of the piston can draw in the refill fluid to fill the first chamber while the catheter entrance remains closed by the negative pressure drop. FIG. 2 shows completion of a refilling process and the piston is at its home position 62 . The refill container is of the “passive type” and does not have a plunger thereby minimizing the risk of inadvertently injecting drug into a body cavity. Refilling from the refill container is possible only when the needle is inserted into the septum and the retracting action of the piston draws in the drug solution by vacuum, a safety feature of this invention as described. As the piston is retracted the collapsible wall 56 expands corresponding to the volume of the refill-fluid being drawn into the first chamber.
[0257] Activation Detector
[0258] To ensure a readiness for refilling, the refilling process can start only when an activation detector is activated. The permanent magnet 92 mounted on septum 88 as shown in FIG. 2 is attached with an internal magnet proximity sensor (not shown) to function as an activation detector for triggering the controller and the motor driver in control board 32 . The use of a magnet proximity sensor using Hall Effect for tuning the operational gradient of the magnetic field normal to the face of the detector is known in the art. Commercially magneto-resistive sensors of the Honeywell Company may be used as an activation detector. These sensors have a high sensitivity with conventional magnets like AlNiCo and ceramic materials and their Wheatstone bridge elements convert the magnetic field direction into a voltage output. Optionally, a Reed Sensor of Cherry Corporation may be used as a magnetically activated switch. The internal magnet proximity sensor (not shown) is in electrical communication with the motor driver and the microprocessor in the IC board of the pump device. To save space in the septum area the Hall Effect circuit 35 of the magnet proximity sensor is integrated in the IC board 32 . When a specified starter-magnet, for activating the pump device, is placed on top of the magnet ring 92 of the pump device 10 across the skin 98 , the activation detector (not shown) detects the change of the magnetic field surrounding the magnet ring 92 and the circuit of the proximity sensor converts the change of magnetic field into a voltage output. The activation detector triggers the controller and the motor driver to start the dispensing function of the pump device with forward motion of the piston. Similarly, when starting a refilling process, a specified refill-magnet is placed on top of the magnet ring 92 across the skin. The refill-magnet is preferably being magnet 96 attached to the needle or part of the refill container. Thus the approaching and docking of a refill container needle can cause the activation detector to activate the pump device with backward motion of the piston for refilling the drug chamber.
[0259] Notification Mode
[0260] For a given implantable drug delivery device and a given infusion profile for a patient, the refill interval is known and, therefore, the time to refill can be planned. However, if refilling does not occur at the appropriate time, a notification signal can be sent by the implantable drug delivery device of this invention. The notification feature utilizes the reciprocating motion of the piston. The motor driver can be programmed to perform a reciprocating motion of the piston at the end of a dispensing cycle to signal for refilling. The amplitude and the frequency of the reciprocating motion are pre-tested for generating a vibration of the pump device which does not cause any harm but is detectable by the patient. As a reminder to the patient to have the device refilled the reciprocating motion may be repeated to signal at a prescribed interval, which is to be determined (TBD) for a patient using the device. For instance the notification mode or the oscillation of the piston may be programmed to repeat at every 12 or 24 hours, depending on the drug and other factors such as coinciding with convenient day time schedules for taking action.
[0261] Verification
[0262] Additionally, there are a number of factors that may cause performance failures of an implanted device. These factors include the malfunction of electronics, hesitation in piston movement, voids in the drug reservoir and possible clogging at the dispensing opening. Therefore, an independent verification of the performance of an implant device is essential to ensure the reliable and predictable performance for the device. For verification of the pump performance of the present invention the position of the piston or a residual amount of dispensing material in the first chamber can be measured externally. As shown in FIG. 2 , piston 28 is fitted with a magnet 76 and the displacement of the magnet mounted on top of the piston can be determined by measuring the distance 70 between the piston magnet 76 and the septum magnet 92 , which is positioned at the center of the septum. The distance between the two magnets can be measured by an external magnetic proximity sensor positioned across the skin. A magnetic proximity sensor can be a commercially available Honeywell HMC1501 or HMC1512 magneto-resistive sensor. These sensors feature Wheatstone bridge elements to convert the magnetic field into a voltage output. The HMC sensors provide reliable performance in accuracy and resolution. This pump performance verification method is more convenient than a method of software interrogation of the number of pulses recorded in the microprocessor chip used for controlling the piston motion for dispensing drug dosages.
[0263] Piezoelectric Motor
[0264] A drive means of an implantable drug delivery pump device of the present invention can be a threaded rod 81 driven by motor 36 as illustrated in FIG. 1 a . The rotation of the threaded rod 81 causes forward and backward movements of piston 28 corresponding to the rotational direction of the motor. As noted previously the mounting of motor 36 creates flow gaps 64 to allow second fluid 24 enter the first chamber behind the piston separating from the first fluid 20 . The second fluid is partially enclosed by the collapsible wall represented by the bellow 26 .
[0265] Preferably, a motor is a piezoelectric motor 36 as illustrated in FIG. 1 a comprising a threaded rod and piezoelectric plates with one end forming a threaded-nut configuration (not shown). The vibration of the piezoelectric plates can cause the threaded rod to rotate. The threaded rod 56 is in free-to-rotate engagement with the piston 28 . Generally the piston may have a non-circular cross-section undergoing linear movement without rotation. The conversion of the rotational motion of threaded rod 81 to a linear motion of the piston is achieved by using a rotational sleeve 83 and rotational retainer 85 . The assembly contains a means for subjecting the threaded nut to ultrasonic vibration causing the threaded shaft to simultaneously rotate and translate in the axial direction. A cylinder supports a threaded nut with a first bending mode resonant frequency in the ultrasonic range. The cylinder and nut are excited at this resonant frequency by transducers that cause the nut to orbit at the end of the cylinder. The transducers may be piezoelectric, electromagnetic or any device that can stimulate the resonant vibration. A detailed description of a piezoelectric motor is given in U.S. Pat. No. 6,940,209 by Henderson.
[0266] Stepper Motor
[0267] Alternatively as shown in FIG. 3 , a piston in an implantable drug delivery pump device of the present invention can be driven by a stepper motor which comprises coils 350 and a threaded shaft 356 . For description purposes, FIG. 3 shows an implantable drug delivery pump device 310 of the present invention comprising a pump housing having walls 314 including two fluid chambers separated by piston 328 with the first chamber 318 as a reservoir containing first or drug fluid 320 , and the second chamber 322 containing second or filler fluid 324 which is enclosed partially by a collapsible wall 326 . Flow gaps behind the piston head allow the second fluid to enter the first chamber preventing any vacuum as the piston moves. Piston 328 is driven by stepper motor 370 , which is mounted with thread shaft 356 .
[0268] Generally piston 328 has a non-circular cross-section and is attached with a free-to-rotate sleeve 383 and rotational retainer 385 to convert the rotational motion of the thread shaft to a linear motion of the piston. The displacement of the piston is proportional to the number of pulses given to the motor coils. The use of a stepper motor is particularly advantageous because the signals applied to its coils are directly related to the displacement of the piston without requiring shaft encoders or sensors. The stepper motor is controlled by the control board 332 which includes an oscillator and a microprocessor and powered by battery 371 . Optionally the oscillator may also be in communication with an external controller by passive telemetry for monitoring and correction of the performance of the device.
[0269] Induction Coils
[0270] Another alternative for driving a piston involves using induction coils. A piston made of electromagnetic or ferrite material can be magnetized by induction coils when an electric current passes through the coil. For description purpose, FIG. 4 a shows an implantable drug delivery pump device 410 of the present invention that comprises a pump housing having walls 414 including two fluid chambers separated by piston 428 with the first chamber 418 as a reservoir containing first or drug fluid 420 , and the second chamber 422 containing second or filler fluid 424 which is enclosed partially by a collapsible wall 426 . Flow opening 464 allows second fluid 424 to enter first chamber behind piston 428 separating from the first fluid. Piston 428 is driven by electrical coils 430 mounted in the annular gap of a cylindrical housing 414 and in a sliding-and-sealing fit with the inner surface of the housing wall 444 . A drive means for a piston of an implantable drug delivery pump device of the present invention comprises a permanent magnet 458 positioned at the outlet end 434 of the first chamber 418 and induction coils 430 being supported by the housing wall 444 . The induction coils magnetize the piston to move in forward and backward directions depending on the polarity of the magnetic field induced by the induction coils in responding to the direction of the electrical current imposed on the induction coils. Piston 428 moves toward the outlet position 434 when the piston is magnetized with a polarity in the same polarity direction as the permanent magnet 458 , and the piston moves away from the outlet position when the piston is magnetized with a polarity in the opposite polarity direction to that of the permanent magnet. For an implantable drug delivery pump device 410 of the present invention using induction coils for driving a piston, the dispensing cycle, the refilling process is similar to what has been described previously. Infusion pump 410 may also include the aforementioned activation detector and verification features. Furthermore, the control of the pump device 410 is accomplished by an external device containing induction coils 460 , which is positioned across the skin 408 opposite to the induction coils 430 of the pump device. FIG. 4 b shows a pump device 410 at the empty state with piston 428 reaching the maximum of travel distance near the outlet opening 434 and the wall of bellow 426 collapsing due to the flow of second fluid 424 filling in the space behind the piston. Also shown in FIG. 4 b is needle 409 of the refilling syringe 470 inserted in septum 406 to start a refilling process, which is controlled by an external controller (not shown) represented by induction coils 460 .
[0271] The timing and frequency of the current pulses applied to the coils can be controlled by an external controller (not shown). Use of an external controller for changing the operational parameter set is well known in the art, such as described in US Patent Application 20080108862 by Jordan; Alain et al. All the activity of the pump is recorded in a memory and a patient can access the data and change the pump parameters by radio frequency (RF) communication with an external control unit. An alternative method without using an RF emitter in an implanted device as “passive telemetry by absorption modulation” by P. A. Neukomm is described in CH 676164, WO 89111701, EP 0377695 and in the article Passive Wireless Actuator Control and Sensor Signal Transmission, Sensors and Actuators, A21-A23 (1990), 258-262.
[0272] Software Control Elements
[0273] The control software in the microprocessor controller of the present invention is programmed to provide Dispensing Mode, Refilling Mode, Notification Mode and Verification-Calibration Mode. In the Dispensing Mode, the microprocessor commands to provide pulses of different durations to control the dispensing rates depending on a prescribed dosage profile, which are converted into a set of operational parameters for the operation of the motor driver. At each dispensing command, after the pre-determined forward pulses. a pre-determined number of backward pulses follow to ensure positive-closing of the slit valve. The required number of backward pulses for closing the slit valve is less than the number of forward pulsed for dispensing such that the desirable amount of drug dosage is dispensed. The schedules and timings of the controller action are based on inputs from an IC oscillator timer built in the IC board of the pump device. The IC circuit for an oscillator timer is well known in the art. With an external controller, the operational parameter set (OPS) in the implant pump of the present invention can be changed as needed. In addition a memory chip in the pump device records the history of forward and backward pulses. An algorithm is provided in the control program to monitor the current amount of drug remaining in the reservoir such that the timing for refilling the reservoir is determined. The maximum travel distance of the piston between the reservoir full and reservoir empty is converted into the maximum number of dispensing pulses, which is pre-programmed with a safety factor in the controller. When the maximum number of dispensing pulses is reached, no further forward movement of the piston is commanded.
[0274] In the Refilling Mode, the needle of a refill container is inserted into the septum and the content is drawn into the first chamber by the retraction of the pump piston. The refill container is of a passive type without having an active plunger for external manual injection, therefore, preventing accidental administration of drug into wrong body tissues. The docking of the needle with the approach of the refill-magnet on the refill container initiates the refilling mode, and the controller microprocessor of the pump device of the present invention commands the motor driver to start the retraction motion of the piston. The motor may be programmed to run at a higher retraction speed at the refilling mode than the speed at the dispensing mode. The duration of the refilling mode is pre-programmed according to the maximum traveling distance of the piston for complete filling of the reservoir.
[0275] The Notification Mode can be programmed for repeated vibration of the pump device to alert the patient to take action to have the pump device refilled. The piston oscillation is initiated at the end of the Dispensing Mode, therefore, no additional drug is dispensed from the slit valve at the Notification Mode. The reciprocation of the piston is operated at detectable amplitude and frequency for a short duration such as a few seconds. The objective is to create vibrations which do not cause any harm or discomfort to the patient but are adequate to alert the patient to take action. At the Notification Mode, the command for the oscillation motion of the piston is repeated over a time interval.
[0276] In the Verification-Calibration Mode, the control program of the infusion pump of the present invention uses the input of a magnetic proximity sensor to measure the distance between the two magnets in the implant pump. The measured distance between the two magnets is converted and compared to the number of pulses for dispensing as recorded in the memory chip. Any discrepancy will be re-adjusted and re-calibrated in the operational parameter set to achieve a correct dispensing profile for continuous usage of the pump device. Such a verification-calibration mode may be integrated with the refilling mode such that the verification-calibration mode is conducted prior to the refilling action.
[0277] As a summary, FIG. 5 shows the interactions of the operation modes of the software control program of the implantable drug delivery pump device of the present invention.
[0278] In summary, the implantable drug delivery pump device of the present invention provides a drug reservoir chamber having a piston and a filler chamber having a collapsible wall to facilitate the dispensing motion of the piston. With a slit valve attached to the catheter dispensing end, the software controlled retraction motion of the piston enables positive closing of the dispensing valve to prevent clogging and for refilling of the drug reservoir. The Notification Mode activates detectable oscillation of the piston to alert the user to take refilling actions. The verification and calibration feature uses external measurement of the distance between two magnets in the pump device to ensure reliable performance of the pump device of the present invention.
[0279] Although the invention has been described with reference to particular embodiments, the description is only an example of the invention's application and should not be taken as a limitation. Various other adaptations and combinations of features of the embodiments disclosed are within the scope of the invention as defined by the following claims.
[0280] Divided-Drug-Chamber Device Configuration
[0281] The infusion pump of this invention comprises a divided first chamber containing a first fluid and a second chamber, enclosed partially by collapsible walls, that contains a second fluid. FIGS. 6 a , 6 b and 6 c show an infusion pump 10 A of the present invention including housing walls 14 A that encompass first chamber 18 A containing first fluid 20 A and second chamber 22 A containing second fluid 24 A. The first chamber 18 A is a drug reservoir containing first fluid 20 A and it is divided into a first compartment 11 A and a second compartment 13 A by a wall 15 A mounted with a one-way valve 17 A. FIG. 6 b shows a top cross-section view of the division between the two compartments 11 A and 13 A by the wall 15 A and the one-way valve 17 A. FIG. 6 c shows the extension of the dividing wall 15 A and the one-way valve 17 A into septum 44 A of the implant device 10 A. The one-way valve provides a flow path 23 A as shown in FIG. 7 a and FIG. 7 b between the first and the second compartments 11 A and 13 A when the valve 17 A is in the open position. The first compartment 11 A has a piston 83 A connected to a driving means and the second compartment 13 A has a follower 28 A, which is in flow communication with the movement of the piston 83 A The wall of the second chamber 22 A is collapsible as represented by a bellows wall 56 A as shown in FIG. 6 a . The second fluid 24 A, which is inert to the drug fluid and body tissues, serves as a filler fluid in communication with the first fluid chamber to fill the space evacuated by the movements of the piston and the follower to prevent creation of a partial vacuum that could negatively impact the movement of the piston and the follower. Both piston 83 A and follower 28 A separate second fluid 24 A from first fluid 20 A. The piston is driven by a drive means for infusing the first fluid through outlet 34 A and reducing the volume of the first fluid in the first compartment. In this divided drug chamber configuration, the drug dosage dispensed at each step of the piston forward movement is a small fraction of the amount for an un-divided configuration.
[0282] Furthermore, a catheter 48 A is attached to outlet 34 A of first chamber 18 A in communication with the first fluid 20 A. The wall 51 A of the first chamber includes a filling septum 44 A for inserting needle 85 A of a refill container to inject a refill drug into the drug chamber. An outlet valve in a form of a slit-valve 52 A is attached at the dispensing end of the catheter. A normally-closed slit-valve prevents backflow of fluids from the external environment into the device. The slit-valve is forced open by the forward movement of the piston exerting pumping pressure allowing the drug to be dosed from the reservoir to the treatment site. The implantable device is implanted into a patient's body, and the catheter can be led to a treatment location where the drug is dispensed. Depending on the geometry and the stiffness of the slit-valve elements, the slit-valve may be partially or fully open corresponding to the steps of the piston advancement. Following a step of dispensing drug, if further piston advancement is minute the slit-valve may be partially open without further dispensing the drug fluid out of the catheter. Being immersed with the dispensed drug still at the valve exit, the drug inside the valve opening is not mixed with the body fluid, which has been pushed away from the valve opening.
[0283] Reciprocating Piston Motion
[0284] The piston performs a reciprocating motion under the control of a motor driver that is mounted in an IC control board 32 A as shown in FIG. 6A , and is preprogrammed. The first fluid is pushed by the forward movement of the piston. The perimeter surface of the piston is in sliding-sealing fit, represented by O-ring 61 A, with the inner wall surface of the first compartment. The sliding-sealing fit or the wiping contact of the piston perimeter surface with the inner wall of the first compartment ensures no residual trace of drug fluid, i.e. the first fluid, comes in contact with the filler fluid on the opposite side of the piston. During the forward motion of the piston the one-way valve is forced to close and the slit-valve at the end of the catheter is forced to open to dispense the first fluid. During the backward motion of the piston a partial vacuum is created in the first compartment that causes the slit-valve to close and the one-way valve to open. As a result, the first fluid 20 A from the second compartment 13 A enters the first compartment IIA through the valve opening 25 A (shown in FIG. 7 a ). Simultaneously, the follower 28 A in the second compartment 13 A moves forward, which induces the filler fluid 24 to fill the space left by the movement of the follower through the flow gaps 64 A to fill the space left by the movement of the piston. The sliding-sealing fit or the wiping contact of the follower perimeter surface with the inner wall of the second compartment ensures no residual trace of drug fluid comes in contact with the filler fluid.
[0285] The filling motion of the filler fluid into the first and the second chambers reduces the volume in the second chamber, thereby, causing the bellows or the collapsible wall 56 A to contract. With the slit-valve closed further retraction of the piston is hindered due to the partial vacuum created inside the first compartment. For a given drug dosage at each infusion event, the number of forward pulses and the immediate number of backward pulses can be predetermined for the device to provide the desired net amount of drug dispensed at the event through the slit-valve. In subsequent repeated reciprocating motion of the piston, the first fluid is incrementally dispensed and the follower is moving forward in each cycle. This process continues until the second compartment is empty. In the empty state, the space behind the follower is full of the filler fluid.
[0286] The dispensing process can start only when an activation detector is activated. lThe permanent magnet 92 A mounted on septum 44 A as shown in FIG. 6 c is attached with an internal magnet proximity sensor (not shown) to function as an activation detector for triggering the controller and the motor driver in control board 32 A. The use of a magnet proximity sensor using Hall Effect for tuning the operational gradient of the magnetic field normal to the face of the detector is known in the art. Commercially magneto-resistive sensors of the Honeywell Company may be used as an activation detector. These sensors have a high sensitivity with conventional magnets like AlNiCo and ceramic materials and their Wheatstone bridge elements convert the magnetic field direction into a voltage output. Optionally, a Reed Sensor of Cherry Corporation may be used as a magnetically activated switch. The internal magnet proximity sensor (not shown) is in electrical communication with the motor driver and the microprocessor in the IC board of the pump device. To save space in the septum area the Hall Effect circuit of the magnet proximity sensor is integrated in the IC board 32 A. When a specified starter-magnet, for activating the pump device, is placed on top of the magnet ring 92 A of the pump device 10 A across the skin (not shown), the activation detector (not shown) detects the change of the magnetic field surrounding the magnet ring 92 A and the circuit of the proximity sensor converts the change of magnetic field into a voltage output. The activation detector triggers the controller and the motor driver to start the dispensing function of the pump device.
[0287] Priming Steps
[0288] To avoid dead spaces, voids or air pockets in a drug delivery device of the present invention, the priming steps for complete filling of the device with drug fluid and filler fluid are as follows.
[0289] Referring to a preferred embodiment as shown in FIGS. 9 a , 9 b and FIGS. 10 a , 10 b , 10 c , 10 d and to start with a new and empty condition and before implanting the device, 1) squeeze and keep the slit valve at open condition, then move follower 128 A to the lower travel limit, i.e. the bottom home position, 2) move piston 183 A to the upper travel limit position, 3) insert an active plunger syringe pre-filled with the drug fluid to the tip of needle into septum 144 A without opening one-way valve 117 A (shown in FIG. 10 c ), 4) inject the drug fluid to fill up second compartment 113 A completely with any possible air bubbles rising (not shown) against the gravity direction in the septum cavity, 5) with the slit valve remaining open, push the syringe needle further to open the one-way valve, 6) inject drug fluid to fill up the septum and the catheter and expel the air through the slit valve 52 A, 7) release the slit valve to resume its self-closing position and retract the piston all the way to the lower travel limit to draw the drug fluid to fill the first compartment completely, 8) remove the syringe from the septum, 9) insert an active-plunger filler fluid syringe needle into the injection port of the filler fluid chamber at the gap under the follower, 10) insert vent needles (not shown) through the wall of the filler fluid chamber at extreme locations of the injection flow path of the filler fluid from the filler fluid injection port for venting air, 11) inject the filler fluid to fill up the filler fluid chamber completely and expel the air through the vent needles, 12) remove the filler fluid syringe and the vent needles. Alternatively, the evacuation of the air can be facilitated by a vacuum means attached to the vent needle during the injection of the filler fluid into the chamber. In addition, the wall areas for inserting the vent needle and the filler fluid syringe needle are of resilient material, which is penetrable and self-closing when the needles are removed. After the above priming steps the device is completely filled with the drug fluid in the first and second compartments of the drug chamber and with the filler fluid in the filler fluid chamber without any dead spaces, voids or air pockets in the device.
[0290] Refilling Process
[0291] Refilling of the first chamber can be accomplished by inserting a refill container 84 A into the septum 44 A of the pump device 10 A as shown in FIGS. 8 c and 8 d . The septum has a raised ring (not shown) to facilitate the positioning of the needle through the skin. FIGS. 8 a , 8 b , 8 c and 8 d illustrate a sequence of refilling steps. FIG. 8 a shows an implantable drug delivery pump device 10 A of FIG. 6 c at full state with both the piston 83 A and the follower 28 A at their home positions. The home position of the follower is the lower travel limit of the follower. A forward movement 60 A of the piston 83 A toward the slit-valve 52 A causes the slit-valve to open under the pumping pressure as shown in FIG. 8 b . After repeated forward and backward movements of the piston the first chamber becomes empty as shown in FIG. 8 b where the follower 28 A reaches the top 35 A of the second compartment 13 A. The top of the second compartment is the upper travel limit of the follower. To refill the device, a refill container 84 A containing refill drug 37 A is inserted into the septum 44 A of the device 10 A as shown in FIG. 8 c . Referring to enlarged views of the flap-type one-way valve mechanism 17 A as shown in FIGS. 7 a and 7 b , correct positioning of the refill container enables the needle 85 A to push open the one-way valve 17 A toward the catheter wall 48 A. Further pushing of the needle 85 A causes the catheter wall 48 A to block the flow of the first fluid 20 A into the catheter 48 A. Forcing the catheter walls 48 A to touch also enables the contact of two thin electrode elements 81 A forming a contact switch, which is in electrical communication with the motor driver in the IC control board 32 A, to activate the reciprocating or pumping motion of the piston. As a reverse of the dispensing function, retraction or backward movement of the piston draws the refill fluid 37 A from the refill container 84 A into the first compartment 11 A and a subsequent forward movement pushes the refill fluid from the first compartment 11 A into the second compartment 13 A through the valve opening 25 A. A series of reciprocating motion of the piston draws in the refill fluid from the refill container and delivers it into the second chamber until both the first and the second chambers are full of the refill fluid. Simultaneously during the refilling process the filler fluid 24 is returned to the bellows through the flow gap 64 A, which is in communication with the filler fluid behind the piston and the follower and the filler fluid in the bellows. During these fluid movements the catheter entrance remains closed by the contact of the refill container needle against the catheter walls. The refill container is preferably a passive type not using an externally-actuated plunger, which is a safety feature for avoiding any accidental injection. As shown in FIG. 8 c , refill container 84 A uses internal disc 87 A, which is in sliding fit with the inner wall of the container, for compacting drug fluid 37 A. FIG. 8 c shows refill container 84 A being full of refill drug fluid 37 A in the beginning of the refilling process. After completion of the refill process the refill container is depleted of the drug fluid and pulled from the septum as shown in FIG. 8 d . At the completion of a refilling process and when the first chamber is full, the piston and the follower are at their home positions and the bellows is at its fully expanded shape.
[0292] Instead of using the flap-type valve 17 A as shown in FIG. 7 a , a plunger-type valve in a divided drug chamber of an implantable drug delivery device 1 OA′ as shown in FIGS. 7 c , 7 d can be used for closing the flow path in the catheter channel by the insertion of the needle of a refill container. Correct positioning of the refill container enables the needle 85 A′ to push open the plunger 19 A toward the catheter wall 48 A′. The plunger 19 A is attached with an electrode-plate 82 A and loaded with springs 17 A′. Further pushing of the needle 85 A′ causes the electrode-plate 82 A to block the flow of the first fluid 20 A into the catheter 48 A′. Forcing the movable electrode-plate 82 A to touch stationary electrode 81 A′ also enables forming a contact switch, which is in electrical communication with the motor driver in the IC control board 32 A, to activate the reciprocating or pumping motion of piston 83 A. The slidable electrode plate 82 A is a thin plate to minimize the displacement of the drug fluid in the catheter and the displaced volume may enter the septum area through the clearance between the electrode plate 82 A and the catheter wall 48 A′. This feature prevents the drug fluid being forced through the catheter valve 52 A (shown in FIG. 6A ) by the insertion of the needle. Upon release of the needle, the springs force the plunger against the partition wall 25 A′, which divides piston chamber 1 I A and reservoir chamber 13 A in the septum area and has opening 26 for the insertion of the needle. With the use of the contact switch, a conventional active plunger-type syringe maybe used for refilling as pushing of the plunger may assist pushing the drug into the drug chamber in addition to the vacuum force created by the withdrawing of the piston in the refilling process triggered by the contact switch.
[0293] Flexible-Layer Filler-Fluid
[0294] Instead of a bellows configuration positioned at the bottom end of a device such as the bellows 56 A shown in FIG. 6 a , the collapsible wall of the second chamber containing the second fluid may be a flexible and soft layer 156 A attached to the housing walls 114 A forming an external fluid chamber of the device 100 A as shown in FIGS. 9 a , 9 b and 9 c . FIG. 9 b shows the flexible layer of the second chamber 122 A attached externally to the housing walls 114 A of the implantable device 100 A of the present invention. Preferably the flexible layer is wrapped from the front side 116 A, around the bottom side 118 A, to the back side 119 A of the housing walls 114 A as illustrated in FIG. 9 b . Side walls 132 A and 134 A and top wall 136 A which is mounted with the septum 144 A and the catheter 148 A are not attached with a soft layer for ease of manufacturing and manual handling prior to implantation procedures. With respect to the flexible external fluid chamber, the first fluid chamber is referred as the internal fluid chamber. In comparison with the bellows configuration as shown in FIG. 6 a the flexible-layer configuration has the advantage of shorter device length and more conformable contact with body tissues. FIGS. 9 b and 9 c also show the filler-fluid openings 170 A and 172 A. The first filler-fluid opening 170 A on the first compartment wall 180 A is for the entrance and exit of the second fluid 124 A behind the piston 183 A as the piston moves forward and backward, respectively. On the other hand, the second filler-fluid opening 172 A on the second compartment wall 182 A is for the entrance and exit of the second fluid behind the follower 128 A as the follower moves forward and backward, respectively, following the piston movement.
[0295] Openings for the Passage of Filler Fluid
[0296] Specifically, FIGS. 10 a , 10 b , 10 c , and 10 d show the contraction and expansion of the external soft layer 156 A containing the filler fluid 124 A in a sequence of the refilling process of device 100 A. FIG. 10 a shows an implantable drug delivery device 100 A of FIG. 9 b at the full state with both the piston and the follower at their home positions. A forward movement as indicated by the arrow 160 A of the piston 183 A toward the slit-valve 52 A causes the slit-valve to open under the pumping pressure. After repeated forward and backward movements of the piston the second compartment 113 A is depleted of first fluid 120 A and the space behind the follower 128 A is filled with second fluid 124 A as shown in FIG. 10 b . For refilling, a needle 185 A of refill container 184 A containing refill drug 137 A is inserted into the septum 144 A of the device 100 A as shown in FIG. 10 c . Correct positioning of the refill container enables the needle to push the one-way valve 117 A toward the catheter wall. Further pushing of the needle 185 A causes the catheter walls 149 A to block the flow of the first fluid into the catheter. The touching of the catheter walls also enables the contact of two thin electrode elements 181 A, which are in electrical communication with the motor driver in IC control board 132 A, to activate the reciprocating motion of the piston 183 A. During retraction or backward movement 162 A of the piston, as shown in FIG. 10 c , the drug fluid inside the refill container is drawn into the first compartment while the refill drug inside the second compartment is held back by a partial vacuum as the device is enclosed by body tissues. The refill container is at atmospheric pressure because of the presence of a vent hole (not shown), The next forward movement of the piston pushes the first fluid into the second compartment, similar to flow path 23 A indicated in FIG. 7 a , through the edges of the one-way valve opening, which is similar to valve opening 25 A indicated in FIG. 7 b . A series of such reciprocating pumping motions can draw the filler fluid from the soft-layer second chamber through the first and second filler-fluid openings to fill the space behind the piston and the follower. At the completion of a refilling process as shown in FIG. 10 d , the refill container 184 A is empty, the piston and the follower are at their home positions and the soft-layer chamber is at its fully expanded shape.
[0297] Materials of Device Components
[0298] Referring to FIG. 6 a , walls 54 A of the first chamber and collapsible walls 56 A of the second chamber are impermeable to external fluids present in a body tissue environment. In particular, wall 54 A of first chamber 18 A is made of a drug-compatible, implantable material of sufficient rigidity without deformation so as not to hinder the movement of the piston inside the reservoir chamber. For example, the wall material of the first chamber may be constructed from a metal, such as titanium, nickel titanium, stainless steel, anodized aluminum, or tantalum, or a plastic, such as polyethylene, nylon. However, collapsible wall 56 A of second chamber 22 A is made of flexible material such as silicone or polyurethane, which allows the wall to expand or collapse as fluid goes in and out of the second chamber. For self-sealing the septum is made of resilient material. Referring to FIGS. 7 a and 7 b septum 44 A has a raised ring ridge for positioning the refill through the skin. The raised ring ridge may be in the form of ring magnet 92 A of a polarity that attracts a ring magnet (not shown) of opposite polarity mounted on the needle 85 A of the refill container 84 A. The attraction between the two ring magnets having opposite polarities across the skin can facilitate positioning and stabilizing the refill container needle during the refilling process. The device is implanted preferably near the treatment site and the slit-valve is to be located at the treatment site. In a preferred embodiment the positive-closing slit-valve 52 A is a molded dome-shaped cap of elastomeric materials having a cross-slit cut forming a plurality of flexible flappers. In a preferred embodiment a slit-valve used for the implantable drug delivery pump of this invention is of biocompatible silicone material. The slit-valve has a tubular wall base and four flappers. Each flapper is a curved triangular valve segment extending from the tubular wall base with the tip of each valve segment intercepting at the center, i.e. at the apex of the slit-valve opening when the slit-valve is at the closed position. Each valve segment can be bent like a cantilever beam under the pressure of a dispensing flow. The slit length, wall thickness and the elastic modulus of the valve material are designed to ensure self-closing of the slit-valve by the resiliency and the vacuum force in the absence of pumping pressure. With the use of a slit-valve, it is not necessary to use an outlet check valve to prevent backflow.
[0299] Battery
[0300] An implantable battery used in an implantable pump of the present invention needs to be encapsulated to avoid harmful leaks and diffusion. Generally an implantable pump requires milliampere level current pulses over a constant microampere level background drain. Examples of commercially available implantable batteries are lithium/thionyl chloride and lithium/carbon mono fluoride batteries made by GreatBatch, EaglePicher Medical Power and other manufactures. A Li/CFx battery, which is typically used for pacemakers, neuro-stimulation applications at milliampere application ranges, has a typical lifetime of five to six years. A small implantable battery by EaglePicher achieves a miniature cylindrical size of 0.260″ long×0.090″ diameter that can be packaged inside a pump device with a traditional implantation surgery or implanted at a separate nearby location via a minimally-invasive catheter procedure.
[0301] A preferred embodiment of a battery pack to be used for the present invention is a battery assembly comprising a first battery portion and a second battery portion and a battery-low circuit for switching to the first battery portion for battery-low notification. The first battery has a higher capacity than the second battery with the voltage across the first battery being greater than the voltage across the second battery. The battery assembly is connected to a pickup inductive coil in the implantable drug delivery device, which can be charged by magnetic flux produced by the inductive coil of an external battery charger across the skin. The battery pack includes a current limiting circuit having a current limiting resistor for self-regulating and preventing overcharge.
[0302] The implantations of the battery-low circuit and the recharging of the battery by induction means are well known in the skill of the art.
[0303] Pump Size
[0304] With the advancement of miniaturization technologies, small electrical and mechanical components as well as a concentrated drug formulation can be packaged into a compact size for an implantable device of the present invention. For a commercially available piezoelectric motor, such as SQUIGGLE SQ-306 model by New Scale Inc., the motor size is 10 mm in length and 4 mm in diameter. Its motor driver in an IC control board including ASIC, resonant inductors, Boost circuit and FWD diode developed by Austria Microsystems can be packaged into 10 mm×10 mm×1.5 mm size. The motor can achieve a minimum linear shaft increment of 1 micrometer. With a piston head of 4 mm diameter this minimum increment of 1 micrometer movement results in the dispensing of 12.56 nano-liters fluid volume. With the capability of dispensing drug at the nano-liter scale, the drug chamber size of the drug delivery device can be minimized utilizing the full potential of concentrated or nanoparticle drug formulations as well as for supplying significantly longer period of use before refilling. Using other small components such as, a small implantable battery by EaglePicher which has a miniature cylindrical size of 0.260″ long×0.090″ diameter, enables packaging the key components of the drug delivery device into a compact system for implant applications.
[0305] Notification Mode
[0306] For a given drug chamber size and a given infusion profile for a patient, the refill interval is known, therefore, the time to refill can be planned. However, if refill does not occur in the appropriate time interval, a notification signal can be sent to the patient by the implantable drug delivery device of this invention. The notification feature utilizes the reciprocating motion of the piston. The motor driver can be programmed for a notification mode. In notification mode the motor driver retracts the piston for a predetermined distance then, with the self-closing slit valve remaining at the closed position, performs a small reciprocating motion of the piston with amplitude not exceeding the retracted distance such that no amount of drug fluid is dispensed out of the slit valve. The amplitude and the frequency of the reciprocating motion are preset so as to generate a vibration of the device that does not cause any harm but is detectable by the patient. Conditions for the notification mode include the end of dispensing cycle for refilling and battery low. For a predetermined battery low condition the built-in battery-low circuit in the control microprocessor triggers the notification mode. As a reminder for the patient to refill the device the reciprocating motion may be repeated to signal at a prescribed interval, which is to be determined (TBD) for a patient using the device. For instance the notification mode or the oscillation of the piston may be programmed to repeat at every 12 or 24 hours, depending on the patient's dependency on the drug and other factors such as to coincide with convenient day time schedules for taking action.
[0307] Verification
[0308] Additionally, there are a number of factors that may cause performance failures of an implanted device. These factors include malfunction of electronics, hesitation in piston movement, voids in the drug reservoir and possible clogging at the dispensing opening. Therefore, an independent verification of the performance of an implant device is essential to ensure reliable and predictable performance of the device. For verification of the pump performance of the present invention the position of the piston or a residual amount of dispensing material in the first chamber can be measured externally. As shown in FIG. 6 c follower 28 A is fitted with a second magnet 76 A and the displacement of a magnet mounted on top of the follower can be determined by measuring the distance 78 A between the second magnet 76 A and the first ring magnet 92 A, which is positioned at the center of the septum. The distance between two magnets can be measured by an external magnetic proximity sensor. A magnetic proximity sensor can be a commercially available Honeywell HMC1501 or HMC1512 magneto-resistive sensors. These sensors feature Wheatstone bridge elements to convert a magnetic field into a voltage output. The HMC sensors provide reliable performance in accuracy and resolution.
[0309] Software Control Elements
[0310] The control software in the microprocessor controller of the present invention is programmed to provide Dispensing Mode, Refilling Mode, Notification Mode and Verification-Calibration Mode. In the Dispensing Mode, the microprocessor commands to provide pulses of different durations to control the dispensing rates depending on a prescribed dosage profile, which are converted into a set of operational parameters for the operation of the motor driver. At each dispensing command, after the pre-determined forward pulses, a pre-determined number of backward pulses follows to ensure positive-closing of the slit valve. The required number of backward pulses for closing the slit valve is less than the number of forward pulsed for dispensing such that the desirable amount of drug dosage is dispensed. The schedules and timings of the controller action are based on inputs from an IC oscillator timer built in the IC board of the pump device. The IC circuit for an oscillator timer is well known in the art. With an external controller, the operational parameter set (OPS) in the implant pump of the present invention can be changed as needed. In addition a memory chip in the pump device records the history of forward and backward pulses. An algorithm is provided in the control program to monitor the current amount of drug remaining in the reservoir such that the timing for refilling the reservoir is determined. The maximum travel distance of the piston between the reservoir full and reservoir empty is converted into the maximum number of dispensing pulses, which is pre-programmed with a safety factor in the controller. When the maximum number of dispensing pulses is reached, no further forward movement of the piston is commanded.
[0311] In the Refilling Mode, upon trigging the refill switch by the insertion of the refill container needle, the controller microprocessor of the device of the present invention commands the motor driver to start the reciprocating motion of the piston. The duration of the refilling mode is preprogrammed for complete filling of the reservoir.
[0312] The Notification Mode can be programmed for repeated vibration of the pump device to alert the patient to take action to have the pump device refilled. The piston oscillation is initiated at the end of the Dispensing Mode, therefore, no additional drug is dispensed from the slit valve at the Notification Mode. The reciprocation of the piston is operated at detectable amplitude and frequency for a short duration such as a few seconds. The objective is to create vibrations which do not cause any harm or discomfort to the patient but are adequate to alert the patient to take action. At the Notification Mode, the command for the oscillation motion of the piston is repeated over a time interval.
[0313] In the Verification-Calibration Mode, the control program of the infusion pump of the present invention uses the input of a magnetic proximity sensor to measure the distance between the two magnets in the implant pump. The measured distance between the two magnets can be converted to the amount of drug fluid remaining in the drug chamber and compared to the expected value according to the prescribed dispensing drug profile. The control software program maintains the prescribed dispensing drug profile for a patient for operation of the motor driver. For a specified drug dispensing profile and knowing the time from the start of dispensing, the remaining amount of the drug fluid in the device can be determined, based on the geometry and size of the drug chamber, as an expected distance between the two magnets in the septum and in the piston. This expected distance is regarded as the expected profile value for comparing with the measured distance between the two magnets. If at any time a discrepancy exists, the pump device can be refilled to full state and to record new starting time for the device. Such verification and calibration steps may be taken several times to ensure the continuous use of the pump device according to the intended dispensing profile. The verification-calibration mode should be conducted prior to a routine refilling action.
[0314] As a summary, FIG. 11 shows the interactions of the operation modes of the software control program of the implantable drug delivery pump of the present invention.
[0315] Although the invention has been described with reference to particular embodiments, the description is only an example of the invention's application and should not be taken as a limitation. Various other adaptations and combinations of features of the embodiments disclosed are within the scope of the invention. For example, a stepper motor maybe used as a drive means instead of a piezoelectric motor as described in the present invention. Also, an external power source and external controller may be used to reduce the size of an implantable pump device of the present invention. In such case the pump device needs to include an antenna and a RF receiver. Alternatively, a smaller size may be achieved by separating IC board and battery from the pump mechanism and implanted at different location away from the basic pump mechanism.
[0316] Two-Drug-Chambers Device Configuration
[0317] An implantable dual drug delivery system of this invention features two drug chambers with different refill container-port identifications for matching with correct refill containers of the two drugs. In the following descriptions, first drug fluid and drug A fluid are used interchangeably. Second drug fluid and drug B fluid are used interchangeably. First chamber, drug A chamber and drug A reservoir are used interchangeably. External chamber, filler fluid chamber are used interchangeably.
[0318] Specifically an implantable dual drug infusion pump of the present invention has first drug chamber containing first drug fluid, second drug chamber containing second drug fluid and an external filler fluid chamber containing filler fluid. Each drug chamber is divided by a wall having a one-way valve into a first compartment and a second compartment. Each first compartment has a piston connected to a drive means and each second compartment has a follower, which is in flow communication with the movement of the piston.
[0319] The filler fluid chamber is attached externally to the drug chambers and it contains a filler fluid enclosed by collapsible soft layers. The soft layers are wrapped around housing walls of the drug chambers. The filler fluid is in flow communication with both the first compartment and the second compartment of each drug chamber for filling the space left by the movements of the pistons and the followers. Additionally, the pistons and the followers separate the filler fluid from the first drug fluid and the second drug fluid. The walls of the first and the second chambers as well as that of the external chamber are impermeable to outside fluids present in an operating environment.
[0320] Referring to FIGS. 12 a , 12 b and 12 c , the dual drug delivery device of this invention comprises two independent drug chambers, drug chamber A and drug chamber B, and one filler fluid chamber.
[0321] FIG. 12 a shows drug A chamber 18 B containing drug A20 having catheter 44 B with slit valve 52 B and drug B chamber 18 B′ containing drug B 20 B′ having catheter 44 B′ with slit valve 52 B′. These drug chambers and catheters are oriented in opposite directions. Drug A chamber and drug B chamber are of the same configuration and separated by a common IC control board 32 B and their housing walls 14 B are attached with an external chamber 122 B containing filler fluid 124 B. The drive mechanism for drug A piston 83 B and drug B piston 83 B′ are the same. For simplicity, only the drug chamber configuration and the drive mechanism for drug A are described in FIG. 12 c , which is a side cross-section view of the device of FIG. 12 a . In FIG. 12 a the drug A chamber 18 B is divided into first compartment 11 B and second compartment 13 B by a wall 15 B mounted with a one-way valve 17 B.
[0322] FIG. 12 b further shows a top cross-section view of the division between the two compartments 11 B and 13 B by the wall 15 B and the one-way valve 17 B for the drug A chamber, and the division between two compartments 11 B′ and 13 B′ for the drug B chamber. Also shown in FIG. 12 c is an extension of the dividing wall 15 B and the one-way valve 178 into septum 44 B of the implant device 10 B. In the enlarged view in FIG. 13 , the flap-type one-way valve 17 B provides a flow path 23 B between the first and the second compartments 11 B and 13 B when the valve 17 B is in the open position. The contact switch of electrodes 181 B can be activated by the insertion of the needle 8513 , which also causes the blocking of the catheter channel 49 B. Alternatively, a plunger-type valve similar to that shown in FIGS. 7 c , 7 d for a divided drug chamber can be used for closing the flow path in the catheter channel by the insertion of the needle of a refill container. The first compartment 11 B has a piston 83 B connected to a drive means and the second compartment 13 B has a follower 28 B, which is in flow communication with the movement of the piston 83 B.
[0323] Referring to FIG. 12 c the external chamber 122 B is segmented and attached externally to housing wall 14 B. The external chamber 122 B has an external soft layer which is collapsible. The filler fluid 124 B, which is inert to the drug fluids and body tissues, is in flow communication with the drug chambers for filling the space evacuated by the movements of the piston and the follower to prevent creation of a partial vacuum that, if it were to exist, could negatively impact the movement of the pistons and the followers. Both piston 83 B and follower 28 B (shown in FIG. 13 ) separate filler fluid 124 B from drug fluid 20 B. The piston is driven by a drive means for infusing the drug fluid A through outlet 34 B and reducing the volume of the drug fluid A in the first compartment. The above descriptions for the chamber configuration and the movements of the piston and the follower for drug A are applicable to that for drug B.
[0324] Moreover, referring to the drug A configuration, a catheter 48 B is attached to outlet 341 of drug A chamber 18 B in flow communication with the drug fluid 20 B. The wall 51 B of the drug A chamber includes a filling septum 44 B for inserting needle of a refill container to deliver refill drug into the drug chamber. An outlet valve in a form of slit-valve 52 B is attached at the dispensing end of the catheter. A normally-closed slit-valve prevents the backflow of fluids from the outside environment into the device. The slit-valve is forced to open by the forward movement of the piston exerting pumping pressure to force the drug exiting from the reservoir to the treatment site. Depending on the geometry and the stiffness of the slit-valve elements, the slit-valve may be partially or fully open corresponding to the forward steps of the piston advancement. If the piston advancement is at a minimal number of steps the slit-valve may be partially open without dispensing the drug fluid out of the catheter,
[0325] Reciprocating Piston Motion
[0326] The piston performs a reciprocating motion under the control of a programmable motor driver which is mounted in IC control board 32 B as shown in FIG. 12 a . Each drug fluid is pushed by the forward movement of its respective piston. The perimeter surface of each piston is in slidable sealing fit, represented by O-ring 61 B. with the inner wall surface of the first compartment 11 B. The sliding-sealing fit or the wiping contact of the piston perimeter surface with the inner wall of the first chamber ensures no residual trace of drug fluid left behind the piston that will come in contact with the filler fluid and similarly no residual trace of the filler fluid left on the opposite side of the piston that will contact with the drug fluid. During the forward motion of the piston the one-way valve is forced to close and the slit-valve at the end of the catheter is forced to open to dispense the drug fluid. During the backward motion of the piston a partial vacuum is created in the first compartment that causes the slit-valve to close and the one-way valve to open. As a result, referring to FIG. 12 c , drug fluid 20 B from the second compartment 13 B enters the first compartment 11 B through the valve opening 25 B. Simultaneously, the follower 28 B in the second compartment 13 B moves forward.
[0327] The flow of the filler fluid 124 B between the external chamber 122 B and the drug A chamber 18 B is through first and second filler-fluid openings 170 B and 172 B in housing walls as shown in FIG. 12 b and FIG. 12 c . The first filler-fluid opening 170 B on the first compartment wall 180 B is for the entrance and exit of the filler fluid 124 B behind the piston 83 B as the piston moves forward and backward, respectively. On the other hand, the second filler-fluid opening 172 B on the second compartment wall 182 B is for the entrance and exit of the filler fluid behind the follower 28 B as the follower moves forward and backward, respectively, following the piston movement. The sliding-sealing fit or the wiping contact of the follower perimeter surface with the inner wall of a drug chamber ensures no residual trace of drug fluid left behind the follower that will come in contact with the filler fluid, and similarly no residual trace of the filler fluid left on the opposite side of the follower that will contact the drug fluid.
[0328] The filling of the filler fluid into drug A and drug B chambers reduces the volume in the external filler fluid chamber, thereby causing the collapsible soft layer 56 B to contract. For a given drug dosage at each infusion event, the number of forward pulses and the immediate number of backward pulses can be predetermined for the device to provide the desired net amount of drug dispensed at the event through the slit-valve. In subsequent repeated reciprocating motion of the piston, the drug fluid is incrementally dispensed and the follower is moving forward in each cycle. This process continues until the second compartment is empty. In the empty state, the space behind the follower is full of the filler fluid.
[0329] The dispensing process can start only when an activation detector is activated. The permanent magnet 92 B mounted on septum 44 B as shown in FIG. 12 c is attached with an internal magnet proximity sensor (not shown) to function as an activation detector for triggering the controller and the motor driver in control board 32 B. The use of a magnet proximity sensor using Hall Effect for tuning the operational gradient of the magnetic field normal to the face of the detector is known in the art. Commercially magneto-resistive sensors of the Honeywell Company may be used as an activation detector. These sensors have a high sensitivity with conventional magnets like AlNiCo and ceramic materials and their Wheatstone bridge elements convert the magnetic field direction into a voltage output. Optionally, a Reed Sensor of Cherry Corporation may be used as a magnetically activated switch. The internal magnet proximity sensor (not shown) is in electrical communication with the motor driver and the microprocessor in the IC board of the pump device. To save space in the septum area the Hall Effect circuit of the magnet proximity sensor is integrated in the IC board 32 B. When a specified starter-magnet, for activating the pump device, is placed on top of the magnet ring 92 B of the pump device 10 B across the skin (not shown), the activation detector (not shown) detects the change of the magnetic field surrounding the magnet ring 92 B and the circuit of the proximity sensor converts the change of magnetic field into a voltage output. The activation detector triggers the controller and the motor driver to start the dispensing function of the pump device.
[0330] Priming Steps
[0331] To avoid dead spaces, voids or air pockets in a dual-drug drug delivery device of the present invention, the priming steps for complete filling of the device with drug A, drug B and filler fluid are as follows. Referring to a preferred embodiment as shown in FIGS. 16 a , 16 b and FIGS. 15 a , 15 b for priming the drug A chamber with reference to components for drug A and starting with a new and empty condition before implantation, 1) squeeze and keep the slit valve in the open position while moving follower 28 B to the lower travel limit, i.e. the bottom home position, 2) move piston 83 B to the upper travel limit position, 3) insert an active-plunger syringe, pre-filled with the drug fluid to the tip of the needle, into septum 44 B without opening one-way valve, 4) inject the drug fluid to fill the second compartment completely with any possible air bubbles rising (not shown) against gravity in the septum cavity, 5) with the slit valve remaining open, push the syringe needle further to open the one-way valve, 5) inject drug fluid to fill the septum and the catheter and expel the air through the slit valve, 6) release the slit valve to resume its self-closing position and retract the piston to the lower travel limit to draw additional drug fluid from the syringe to fill the first compartment completely, 8.) remove the syringe from the septum. To prime the drug B chamber with reference to components for drug B, repeat above steps (1) to (8).
[0332] To prime the filler fluid chamber, with both the drug A and drug B chambers totally filled, 1) insert an active-plunger filler fluid syringe needle into the injection port of the filler fluid chamber at the gap below the follower, 2) insert vent needles through the wall of the filler fluid chamber at the extreme opposite location of the injection flow path of the filler fluid from the filler fluid injection port to vent air, 3) inject the filler fluid to fill the filler fluid chamber completely and expel the air through the vent needles until fluid exits the vent, 4) remove the filler fluid syringe and the vent needles. Alternatively, the evacuation of the air can be facilitated by a vacuum means attached to the vent needle during the injection of the filler fluid into the chamber. In addition, the wall areas for inserting the vent needle and the filler fluid syringe needle are of resilient material, which is penetrable and self-closing when the needles are removed. After the above priming steps the device is completely filled with the drug A in the drug A chamber, drug B in the drug B chamber and the filler fluid in the filler fluid chamber without any dead spaces, voids or air pockets in the device.
[0333] Refilling Process
[0334] FIGS. 14 a , 14 b , 14 c , 14 d show a sequence of the refilling process of device 10 B including the contraction and expansion of the external soft layer 56 B containing the filler fluid 124 B. FIG. 14 a shows an implantable dual drug delivery device 10 B as described in FIG. 12 c at the full state with both the piston and the follower at their home positions. The home position of the follower is the lower travel limit of the follower. A forward movement as indicated by the arrow 160 B of the piston 83 B toward the slit-valve 52 B causes the slit-valve to open under the pumping pressure. After repeated forward and backward movements of the piston the second compartment 13 B is depleted with drug A fluid 20 B but filled with filler fluid 124 B behind the follower 28 B as shown in FIG. 14 b . The top end of the second compartment is the upper travel limit of the follower. For refilling, a needle 185 B of refill container 184 B with refill drug A 137 B is inserted into the septum 44 B of device 10 B as shown in FIG. 14 c . Correct positioning of the refill container enables the needle to push open the one-way valve 17 B toward the catheter wall. Further pushing of the needle 185 B forces the catheter walls 149 B to close and block the flow of the drug A fluid into the catheter. Contacting of the catheter walls also enables the contact of two thin electrode elements 18113 , which are in electrical communication with the motor driver in IC control board 32 B, to activate the reciprocating motion of the piston 83 B. During retraction or backward movement 162 B of the piston as shown in FIG. 14 c only the refill drug A inside the refill container, which is compacted by slidable disc 185 B at atmospheric pressure due to the presence of vent opening 186 B, is drawn into the first compartment while the refill drug A inside the second compartment is held back by a partial vacuum as the device is enclosed by body tissues. The next subsequent forward movement of the piston pushes the first fluid into the second compartment, similar to flow path 23 B in FIG. 13 a , through the edges of the one-way valve opening. A series of such reciprocating pumping motions can draw in the filler fluid 124 B from the soft-layer external chamber 122 B through the first and second filler-fluid openings to fill the space behind the piston and the follower. At the completion of a refilling process as shown in FIG. 14 d indicating an empty refill container 184 B the piston and the follower are at their home positions and that the soft-layer chamber is at its fully expanded shape. Note that the refill container is of a “passive type” having no plunger thereby avoiding any accidental injection. Infusion from the refill container is possible only by the pumping action of the piston.
[0335] Failsafe Refill Container Feature
[0336] The refilling of the dual drug delivery device of the present invention preferably uses self-locking refill containers to prevent the injection of drug into the wrong drug chamber. To ensure the correct matching of a drug refill container with the septum of the same drug, magnets of opposite polarities are used to create an attraction force between the matched refill container and the septum. With a mismatched refill container and septum, a repelling force is created that locks the refill container. For clarity, a magnet of a septum of drug A chamber is used for illustration in FIG. 15 a and FIG. 15 b . The magnet is preferably a ring magnet which is hollow at the center for inserting the needle of the refill container through the septum. FIG. 15 a shows attraction force 230 B between the matched refill container A 284 B and magnet 92 B of the septum of the drug chamber for drug A. As a result, magnet 260 B of the refill container is attracted to the magnet 92 B of drug A chamber 18 B, therefore, opening the flow path, as shown in FIG. 16 a , from the reservoir 237 B to drug chamber 18 B.
[0337] The self-locking refill container 284 B comprises a needle 285 B, a tubular housing containing drug fluid 237 B. The tubular housing includes a valve chamber 262 B having an open end 261 B in communication with needle 285 B and a reservoir chamber 264 B which is attached with a slidable disc 289 B forming an enclosed bottom. An orifice plate 240 B is positioned between and separating valve chamber 262 B and reservoir chamber 264 B. Orifice plate 240 B has orifice 255 B at the center for passage of the drug fluid from the reservoir chamber to the valve chamber. The drug fluid is compacted by the slidable disc, which is at atmospheric pressure due to the presence of vent opening 291 B. In a preferred embodiment the movable magnet 260 B is an annular ring configuration. The annular magnet ring 2608 has a top surface having a solid block area 252 B in the center and a plurality of slot openings 250 B surrounding the center block area 252 B. The annular magnet ring 260 B has a polarity that is opposite to the ring magnet 92 B of the septum of the same drug such that the annular ring 260 B is attracted away from the orifice plate 240 B when the needle of the refill container is inserted into the septum of the correct drug chamber. When the top surface of the annular magnet ring is away from the orifice plate, a flow path is created for the drug fluid to be drawn into the drug chamber.
[0338] FIG. 15 b shows a repelling force 232 B between a mismatched refill container 284 B′ of drug B and ring magnet 92 B of the septum of drug A chamber. The refill container 284 B′ of drug B has the same configuration as that of the refill container 284 B of drug A except that the polarity of its annular magnet with refill drug A 137 B is inserted into the septum 44 B of device 10 B as shown in FIG. 14 c . When needle 285 B′ of the refill container is inserted into the septum of drug A. its annular ring is repelled toward the orifice plate 240 B′ such that the solid block area 252 B′ completely blocks the opening of the orifice plate 240 B′. As a result, the refill container of drug B is locked as the flow of the drug is blocked from flowing into the drug chamber A. All the ring magnet valves used in the refill container are to be coated with an inert, biomedical and drug compatible material to prevent reaction with the drugs delivered by the device.
[0339] Matched Filling Condition
[0340] A matched refilling condition is shown in FIG. 16 a and FIG. 16 b . FIG. 16 a shows an implantable dual drug delivery device 10 B of the present invention in which the polarity of the ring magnet 260 B of the refill container 284 B of drug A 237 B is opposite to that of the septum ring magnet 928 of drug A chamber 188 . Due to the attraction force 230 B between the two ring magnets 92 B and 260 B, the refill container 284 B is unlocked internally when inserted into the septum. The contact of two electroplates 181 B pushed by the refill container needle activates the motor driver in the IC control board 32 B to start reciprocating motion of the piston 28 B. The internal mechanism of refilling is as described previously on FIG. 14 c and FIG. 14 d . The refilling stops when the refill container A 284 B becomes empty 238 B as shown in FIG. 16 b or when the reciprocating motion of the piston reaches a predetermined time interval according to the software control program. FIG. 16 b also shows that the soft layer 56 B of the filler fluid 124 B has been expanded fully and the refill container being removed from the septum.
[0341] In a mis-matched condition, FIG. 17 a shows a dual drug delivery device 10 B of the present invention being inserted with a refill container 284 B of drug A into the septum 44 b ′ of drug B chamber 18 B′, as indicated in FIG. 12 a . In this case the polarity of the annular ring magnet of the refill container is the same as that of the septum. Therefore, the annular ring magnet ring 260 B is repelled blocking the opening 255 B in the base plate. As a result, the refill container 284 B is internally locked so that the flow from the refill container is prevented. With correct matching, refill container 284 B′ of drug B 237 B′ should be used and the polarity of its annular ring magnet is opposite to ring magnet 92 B′ of septum 44 B′ of drug B as shown in FIG. 17 b . FIG. 17 c shows the completion of the refilling of drug B as the refill container 284 B′ is being removed from the septum 44 B′.
[0342] Two Drug Chambers of Same Orientation
[0343] In the forgoing descriptions, two drug chambers and their catheters are aligned in opposite directions. Also, alternatively, each drug chamber may not be divided into two compartments by a wall having a one-way valve. FIG. 18 a and FIG. 18 b show an implantable dual drug delivery pump device 700 B of the present invention having two drug chambers 718 B and 718 b and their catheters 748 B and 748 B′ aligned in the same direction. Drug A chamber 718 B and drug B3 chamber 718 B′ contain drug A 720 B and drug B 720 B′, respectively, and each drug chamber is undivided. FIG. 18 b is a top view from a cross-section showing spatial arrangement of the drug chambers 718 B and 718 B′. The pistons 783 B and 783 B′ in the chambers are driven by motors 736 B and 736 B′, which are driven by a common motor driver in the IC control board 732 B. The operation of each drug chamber of the dual drug delivery device as shown in FIG. 18 a is similar to that of dual-drugs delivery device having an opposite orientation as shown in FIG. 12 a . However, the dispensing and the refilling actions for an undivided drug chamber 718 B without using an internal one-way valve are simpler than that for a divided drug chamber 18 B of FIG. 2 a . For an undivided drug chamber configuration no reciprocating motion is required for piston movement to effect dispensing and refilling actions. Pistons 736 B and 736 B′ are driven independently forward for pre-determined number of steps to dispense the desirable drug dosage until the drug reservoir is empty. For refilling, after a refill container of the same drug is inserted, activating the contact switch for the piston of the same drug chamber, then the piston is automatically retracted to draw the refill drug fluid into the drug chamber until the drug chamber is full. Simultaneously the filler fluid 724 B fills the space behind the piston during the dispensing mode and leaves the space during the refilling mode. Following the movement of the filler fluid the soft layer 756 B of the filler fluid chamber contracts and expands in the dispensing mode and the refilling mode, respectively. In comparison with the divided drug chamber configuration, the minimum amount of drug fluid dispensed per piston advancement is higher than that of the undivided configuration. The selection of divided or undivided drug chamber depends on drug concentrations, frequency of infusion and the size limitation of the dual-drug pump device.
[0344] Ultrasonic Motor
[0345] A drive means of an implantable infusion delivery device of the present invention can be a threaded rod 81 B driven by motor 36 B as illustrated in FIG. 12 a . The rotation of threaded rod 81 B causes forward and backward movements of piston 83 B corresponding to the rotational direction of the motor. Preferably motor 36 B is a piezoelectric motor, which is illustrated in FIG. 12 a comprising threaded rod 81 B and piezoelectric plates (not shown) with one end forming a threaded-nut configuration (not shown). The vibration of the piezoelectric plates can cause the threaded rod to rotate. Threaded rod 81 B is in free-to-rotate engagement with the piston 28 B. Generally the piston may have non-circular cross-section undergoing linear movement without rotation. The conversion of rotational motion of thread rod 81 B to linear motion of the piston is achieved by using a rotational sleeve and a retainer.
[0346] Materials of Device Components
[0347] Referring to FIG. 12 a , walls 52 B of the first chamber and collapsible soft layer 56 B of and the filler fluid chamber are impermeable to external fluids present in a living tissue environment. In particular, walls 52 B of drug chambers are made of a drug-compatible, implantable material of sufficient rigidity without deformation so as not to hinder the movement of piston inside the reservoir chamber. For example, the wall material of the drug chambers may be constructed from a metal, such as titanium, nickel titanium, stainless steel, anodized aluminum, or tantalum, or a plastic, such as polyethylene, nylon, or polyurethane. However, soft layer wall 56 B of filler fluid chamber 122 B is made of flexible material such as silicone, or polyurethane, which allows the wall to expand or collapse as fluid is added or withdrawn from the first chamber into the filler fluid chamber. For self-sealing the septum is made of resilient material. Preferably PDMS is selected for its flexibility and ability to reseal itself after repeated punctures via a refill container needle.
[0348] In implantation, a drug delivery device is implanted near the treatment site and the slit-valve is to be located at the treatment site. In a preferred embodiment positive-closing slit-valve 52 B is a molded dome-shaped cap of elastomeric materials having a cross-slit cut forming a plurality of flexible flappers. In a preferred embodiment a slit-valve used for the implantable infusion pump of this invention is of biocompatible silicone material. The slit-valve has a tubular wall base and four flappers. Each flapper is a curved triangular valve segment extending from the tubular wall base with tip of each valve segment intercepting at the center, i.e. at the apex of the slit-valve opening when the slit-valve is at the closed position. Each valve segment can be bent like a cantilever beam under the pressure of a dispensing flow. The slit length, wall thickness and the elastic modulus of the valve material are designed to ensure self-closing of the slit-valve by the resiliency and the vacuum force at the absence of pumping pressure. With the use of a slit-valve, it is not necessary to use an outlet check valve for preventing backflow.
[0349] Software Control Elements
[0350] The control software in the microprocessor controller of the present invention is programmed to provide Dispensing Mode, Refilling Mode, Anti-Clogging Mode, Notification Mode and Verification-Calibration Mode. In the Dispensing Mode, the microprocessor commands for dispensing drug A and drug B are independent. For each drug the microprocessor sends commands to provide pulses of different durations for controlling the dispensing rates depending on a prescribed dosage profile and schedule for the drug, which are converted into a set of operational parameters for the operation of the motor driver for the drug. At each dispensing command, after the pre-determined forward pulses, a pre-determined number of backward pulses follow to ensure positive-closing of the slit-valve. The required number of backward pulses for closing the slit-valve is less than the number of forward pulses for dispensing such that the desirable amount of drug dosage is dispensed. The schedules and timings of the controller action are based on inputs from an IC oscillator timer built in the IC board of the pump device. The IC circuit for an oscillator timer is well known in the art. With an external controller, the operational parameter set (OPS) in the implant device of the present invention can be changed when the need of the patient changes. In addition a memory chip in the device records history of forward and backward pulses for each drug. An algorithm is provided in the control program to monitor the current amount of drug remaining in each drug chamber such that the timing for refilling each of the two drug chambers is determined. The maximum travel distance of the piston in a drug chamber in between the chamber full and chamber empty is converted into the maximum number of dispensing pulses, which is pre-programmed with a safety factor in the controller. When the maximum number of dispensing pulses is reached, no further forward movement of the piston is commanded.
[0351] In the Refilling Mode, upon triggering the refill switch by the insertion of a refill container needle in the septum of a drug chamber, the controller microprocessor of the device of the present invention commands the motor driver to start the reciprocating motion of the piston in the drug chamber. The duration of the refilling mode is pre-programmed for complete filling of the drug chamber.
[0352] The Notification Mode can be programmed for repeated vibration of the pump device to alert the patient to take action to have the pump device refilled. The piston oscillation is initiated at the end of the Dispensing Mode, therefore, no additional drug is dispensed from the slit valve at the Notification Mode. The reciprocation of the piston is operated at detectable amplitude and frequency for a short duration such as a few seconds. The objective is to create vibrations which do not cause any harm or discomfort to the patient but are adequate to alert the patient to take action. At the Notification Mode, the command for the oscillation motion of the piston is repeated over a time interval.
[0353] In the Verification-Calibration Mode, the control program of the dual infusion pump of the present invention uses the input of a magnetic proximity sensor which measures the distance between the two magnets in each drug chamber. The measured distance between the two magnets can be converted to the amount of drug fluid remaining in the drug chamber and compared to the expected value according to the prescribed dispensing drug profile. The control software program maintains the prescribed dispensing drug profile for a patient for the operation of the motor driver. For a specified drug dispensing profile and knowing the time from the start of dispensing, the remaining amount of the drug fluid in the device can be determined, based on the geometry and size of the drug chamber, as an expected distance between the two magnets in the septum and in the piston. This expected distance is regarded as the expected profile value for comparison with the measured distance between the two magnets. If at any time a discrepancy exists, each drug chamber of the dual pump device can be refilled to full state and a new starting time recorded for the device. Such verification and calibration steps may be taken several times to ensure the continuous use of the dual pump device follows the intended dispensing profile. The verification-calibration mode should be conducted prior to a routine refilling action.
[0354] As a summary, FIG. 19 shows the interactions of the operation modes of the software control program of the implantable drug delivery pump of the present invention.
[0355] Although the invention has been described with reference to particular embodiments, the description is only an example of the invention's application and should not be taken as a limitation. Various other adaptations and combinations of features of the embodiments disclosed are within the scope of the invention. | The invention relates generally to implantable drug delivery devices. Devices having a single drug chamber configuration, a divided drug chamber configuration and a compact dual-drug configuration are described. The devices have features to prevent clogging of the dispensing catheter and the creation of a local vacuum caused by the dispensing of the drug fluid. Also provided are features of a failsafe refilling process, automatic refill notification, and performance verification process. The divided drug chamber configuration enables frequent or continuous minute doses. A dual-drug chamber configuration uses self-locking refill containers to prevent mismatching between refill containers and drug chambers. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to mines, and in particular, to accessories that can be secured to a mine in order to destroy it.
2. Description of Related Art
Land mines are still considered a necessary part of warfare. Of course, a lingering problem is finding, and disabling or destroying the land mines after hostilities cease. While combatants may try to make maps indicating locations of land mines, these maps are often hastily made and inaccurate, or are lost in the destruction that is part of armed conflict. Oftentimes, there is simply not the resources available to devote the time needed for carefully tracking down, and extracting or detonating these mines.
There have been many proposals for disabling or destroying land mines after they are no longer needed. These designs have employed internal timing devices or remote controls for either disabling or detonating the mine. These features, however, are part of the original land mine as manufactured. Existing inventories of land mines cannot be simply modified to include these safety features.
For example, in U.S. Pat. No. 3,603,258 pin 106 punctures diaphragm 104 after a mine is armed. The punctured diaphragm allows piston 96 to slowly move and eventually operate a mechanism to self-destructively detonate the mine. This mechanism is internal and cannot be readily used to retrofit a mine to achieve self-destruction. See also U.S. Pat. No. 3,739,725 (hydroscopic material 18 gradually softens to withdraw pin 13, which causes a mine to self-destruct).
In U.S. Pat. No. 6,142,080 an electronic timer senses the cessation of spinning of a projectile to start a timer that eventually will electrically detonate the explosive charge. In U.S. Pat. No. 3,657,571 an electronic timer is used to self-destruct a land mine. In U.S. Pat. No. 6,244,184 a timer is started upon the launch of a projectile carrying submunition grenades. Capacitors in the timing circuits in each of the grenades self-destruct the grenades after a period of time. None of these technologies are readily implemented as a retrofit. See also U.S. Pat. No. 3,983,819.
Encoded signals have been used to trigger underwater devices designed to destroy underwater mines. In U.S. Pat. No. 4,369,709 an underwater device is armed after reaching a proper operating depth. The device can be detonated by coded signals received through a hydrophone. In U.S. Pat. No. 5,042,387 a device has an upper buoyant portion and a lower sinking portion, which are both able to attach to a mooring line of a mine. The upper and lower units detach and move toward the mine and the mine seat, respectively. A sonar signal from a surface ship detonates both devices to destroy the mine and to sever the mooring line. See also U.S. Pat. Nos. 4,696,234; 4,970,957; 5,771,833; and 6,308,633. These references concern highly specialized underwater equipment and do not teach techniques for simply retrofitting land mines in order to safely destroy or disable them.
In U.S. Pat. No. 5,415,103 an interrogation unit can program a land mine to set the conditions under which the land mine will detonate. See column 1, lines 16-17. The electrical firing circuit of U.S. Pat. No. 5,218,574 provides several operating modes for a land mine. In one mode, an electrolytic timing device can detonate the land mine after a predetermined delay.
In U.S. Pat. No. 4,856,431 a directional mine is armed by inserting firing unit 6, which is locked into place by pin 15. The mine can be detonated by firing the igniter 11. After a pre-programmed amount of time, however, an electromagnet retracts pin 15 to eject unit 17, thereby disarming the mine. This reference is relatively complicated and does not lend itself to a simple retrofit.
In U.S. Pat. No. 4,712,478 slider 30 has a passage that moves into position just before detonation to create a firing path. The land mine can be neutralized by an undefined circuit that fires detonator 44 before slider 30 is in the armed position. Alternatively, the battery that operates circuit 10 can run down and disable the land mine. This reference has no teachings that would allow a simple retrofit for existing land mines.
In U.S. Pat. No. 4,854,239 a munition is fired by two explosively powered pistons, if they are fired in a proper sequence before a third piston is fired. Premature firing of the third piston will fracture a component, which is then elevated to indicate the munition is disabled. Again, this complicated reference would not be suitable for a simple retrofit.
See also U.S. Pat. Nos. 3,115,834; 3,447,461; 3,667,387; 4,058,061; 4,712,480; 4,854,239; 5,511,482; and 6,112,668, cited in the pending U.S. patent application Ser. No. 09/578,096, filed May 25, 2000 by the same inventor. See also U.S. Pat. Nos. 3,667,387 and 3,994,227.
Accordingly, there is a need for a self-destruct accessory that can be installed on a land mine in a simple and reliable fashion.
SUMMARY OF THE INVENTION
In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a self-destruct accessory for a mine whose case has a cap that can be depressed to detonate the mine. The accessory includes a cover sized to fit on the cap and has a plurality of lines for securing the cover to the mine. Also included is an explosive charge mounted upon the cover and a detonator located adjacent to the explosive charge. Firing of the detonator can cause the explosive charge to explode. The explosive charge can explosively depress the cap when the cover is mounted on the cap. The accessory also includes a remotely controllable device coupled to the detonator for firing it.
According to another aspect of the invention a method employing an explosive cover can destroy a mine whose case has a cap that can be depressed to detonate the mine. The method includes the step of fitting on the cap the explosive cover. The cover holds an explosive charge and a detonator. Another step is securing the cover to the mine with a plurality of lines. The method also includes the step of sending a detonation signal to the detonator from a remote location to detonate the explosive charge and explosively depress the cap in order to detonate and destroy the mine.
By employing the foregoing principles, an improved technique is achieved for destroying a mine with a self-destruct accessory. In one preferred embodiment, a cover is designed to fit closely over the cap of a land mine. Preferably, a number of straps extend from the edge of the cover and are used to secure the cover to the land mine. The ends of the straps can be fastened together using various connectors or buckles. Alternatively, the straps can extend from the side of the cover and attach to a fastener on the opposite side of the cover. In any event, the cover is installed in such a way that the land mine can be deployed in the usual fashion and will explode when pressure is applied to be cover to depress the cap of the land mine.
In a preferred embodiment an explosive charge can be mounted atop a supporting plate of the cover. When the land mine is no longer needed, an encoded signal can be sent to a remotely controlled detonator in the cover. This detonator can ignite a primer that in turn detonates the main explosive charge. The main explosive charge produces a pressure wave that depresses the cap of the land mine so it explodes safely.
BRIEF DESCRIPTION OF THE DRAWINGS
The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred but nonetheless illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is perspective view of an accessory about to be installed on a mine in accordance with principles of the present invention;
FIG. 2 is a perspective view of the accessory of FIG. 1 installed on the land mine;
FIG. 3 is a detailed, fragmentary view of the connection between the lines on the underside of the land mine of FIG. 2;
FIG. 4 is plan view of the underside of the cover of FIG. 1 with a portion of its supporting plate broken away to show the contents of the cover;
FIG. 5 is an elevational, cross-sectional view of the cover of FIG. 4;
FIG. 6 is a cross-sectional view of a cover that is an alternate to that shown in FIG. 5;
FIG. 7 is a cross-sectional, elevational view of a cover that is an alternate to that shown in FIG. 5 with a portion broken away for illustrative purposes;
FIG. 8 is a detailed, cross-sectional view of a fastener that is an alternate to that shown in FIG. 5; and
FIG. 9 is a schematic block diagram of a receiver and transmitter that may be employed in the foregoing embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1-5, a self-destruct accessory is shown as a cover 10 with two female mating lines 12 and two male mating lines 14 . Preferably, the proximal ends of lines 12 and 14 are integrally molded to the edge of cover 10 . Lines 12 are shown secured to the edge of cover 10 at the three and six o'clock positions, while lines 14 are at the nine and twelve o'clock positions. Other embodiments may have a different number of lines located at different positions that are not necessarily equidistantly spaced.
The distal ends of the female mating lines 12 each have a ratchet clasp 12 A in the form of a hollow box that is open at two opposite ends. The ratchet clasp 12 A contains an inclined tooth 12 B, one such tooth being visible through the distal opening shown in FIG. 1 . Clasp 12 A is designed to receive the male mating line 14 , which may be inserted in only one direction, retraction being prevented by the inclined tooth 12 B. Ratchet clasp 12 A may be a conventional type of clasp, often referred to as a zip tie.
Most of the length of such lines 12 and 14 are plastic straps with the male straps 14 having a series of ratchet teeth 14 A on one side. The ratchet clasp 12 A is integrally molded with the length of the rest of the line. In other embodiments, the clasp may be a plate with two parallel slots through which the mating strap 14 can be threaded. Various other types of buckles and fasteners may be used as well. In simplified embodiments, the lines may work without any fastener and may simply be tied together.
Cover 10 is designed to fit over the cap 16 that is mounted atop case 18 of the land mine 20 . This land mine 20 is a conventional mine that detonates when downward pressure depresses cap 16 . In this embodiment cover 10 has a circular outline in order to fit onto cap 16 , but in other embodiments the cover may have a different outline designed to fit over another specific land mine with a different outline.
Cover 10 has a top plate 22 with an integral annular sidewall 24 designed to encompass cap 16 . Mounted concentrically inside sidewall 24 is an internal annular wall 26 that extends over 300°, leaving an opening into which a booster charge 28 protrudes. Mounted under plate 22 between walls 24 and 26 is an annular explosive charge 30 that extends 360° and lies against booster 28 . Circular bottom plate 32 fits closely inside the annular wall 24 and encloses the space under top plate 22 .
An antenna 34 runs along the inside of wall 26 and connects to remotely controllable device 36 , which has the receiver 36 A and decoder 36 B shown in FIG. 9 . As explained further hereinafter, device 36 is able to ignite booster charge 28 in response to encoded signals received by antenna 34 . Antenna 34 , device 36 , and booster charge 28 fit between plates 22 and 32 , and are herein collectively referred to as a detonator.
Referring to the alternative embodiment of FIG. 6, components identical to those previously described in connection with FIGS. 1-5 bear the same reference numeral, while components that are only similar are identified with the same reference numeral but marked with a prime (′). Cover 10 ′ has an upper plate 22 ′ surrounded by an integral annular sidewall 24 ′. Plate 22 ′ has a central chamber partially encompassed by internal wall 38 to hold a central explosive charge 30 ′. In this embodiment, explosive charge 30 ′ has a cylindrical shape. Fitting in a gap in internal wall 38 is a booster charge 28 ′, which can be ignited by detonator device 36 ′. Booster charge 28 ′ is located between explosive charge 30 ′ and detonator device 36 ′.
As before, explosive device 36 ′ is connected to an antenna (not shown) for receiving encoded signals. In this embodiment, the components involved in the explosive chain are all centrally located inside cover 10 ′, in contrast to the distributed, annular explosive charge 30 of FIG. 4 .
Referring to FIG. 7, alternative cover 40 has a base plate 42 with an integral annular sidewall 44 . Cover 40 also has mounted atop plate 42 an inverted annular channel 46 containing an annular explosive charge 48 . Also mounted atop plate 42 to the inside of channel 46 is a detonator 36 that is identical to the one previously mentioned in connection with FIG. 4 . As before, detonator 36 cooperates with an antenna and a booster charge (not shown). The booster charge fits in a gap in channel 46 (similar to the gap shown in wall 26 of FIG. 4) and can be ignited by detonator 36 to explode explosive charge 48 . Detonator 36 is covered by an upper plate 50 that fits onto an annular outside ledge on the upper inside corner of channel 46 .
Integrally molded on the bottom edge of annular sidewall 44 are two lines, one such line 52 being shown in FIG. 7 . Two mating fasteners 54 (one visible in this view) are mounted on the side of annular sidewall 44 . Fastener 54 is in the form of a tunnel through which line 52 can be threaded. An inclined tooth 54 A inside fastener 54 allows insertion of line 52 in one direction (upwardly through fastener 54 in this view). Teeth (not shown) on the inside face of line 52 engage tooth 54 A to ensure this unidirectional insertion. Fastener 54 operates in a manner similar to that associated with fastener 12 A of FIG. 1 .
Referring to FIG. 8, an alternative fastener is shown that can replace fastener 54 of FIG. 7 . This fastener has an eccentric barrel 58 pivotally mounted on pin 60 between a pair of embossments 62 (one visible in this view) on annular sidewall 44 ′ (corresponding to sidewall 44 of FIG. 7 ). The lever 64 mounted on eccentric barrel 58 can be used to manually rotate barrel 58 to change the spacing between sidewall 44 ′ and barrel 58 . By rotating lever 64 in the direction indicated by the arrow 65 , the gap between barrel 58 and sidewall 44 ′ is reduced so that a line (such as line 52 of FIG. 7) can be gripped between elements 58 and 44 ′.
Referring to FIG. 9, radio receiver 36 A detects a radio signal from antenna 34 and applies the detected signal to decoder 36 B. Receiver 36 A can detect AM or FM signals modulated in a variety of fashions, especially pulse code modulation. The signal from receiver 36 A is a series of encrypted bits that are sent to decoder 36 B for decoding. If a self-destruct code is received, decoder 36 B sends an ignition signal to a booster charge, for example booster charge 28 of FIG. 4 . This encoded signal is produced by encoder 68 that modulates transmitter 66 to transmit an encoded signal through antenna 70 .
To facilitate an understanding of the principles associated with the foregoing apparatus, its operation will be briefly described in connection with the embodiment of FIGS. 1-5 and 9 . Land mine 20 is a conventional mine that an armed force may already have in inventory. Mine 20 lacks the ability to be destroyed by a remote control. For this reason, mine 20 is retrofitted with cover 10 . Cover 10 is placed over cap 16 with sidewall 24 encircling cap 16 as shown in FIG. 5 .
Cover 10 is secured in place by joining together each of the lines 14 with a mating line 12 on the opposite side of cover 10 . As shown in FIG. 3 line 14 is inserted through the opening in fastener 12 A. Teeth 14 A ratchet over the inclined tooth 12 B (FIG. 1 ). Tooth 12 B is inclined to allow insertion of line 14 in one direction so that lines 12 and 14 can be tightened around mine 20 and will not loosen. Once lines 12 and 14 have been tightened they form two transverse bindings around mine 20 as shown in FIG. 2 . Lines 12 and 14 are not tightened so much as to depress cap 16 . Depression of cap 16 by tightening lines 12 and 14 is unlikely since normally about 35 pounds of force must be applied to depress cap 16 in order to detonate mine 20 .
Mine 20 with the newly installed cover 10 can be returned to inventory or can immediately be used in combat. Mine 20 can be laid in the usual fashion at a theater of operations. Personnel or vehicles that cross over mine 20 will depress cap 16 in the usual fashion to detonate the mine.
After hostilities cease land mine 20 may still remain in place unexploded. Finding and exploding/disabling land mine 20 in the conventional manner is obviously extremely dangerous. This danger is augmented by the fact that the exact location of land mines may not be known because they were scattered randomly or because the map of their location was destroyed in the preceding conflict.
With the present accessory 10 land mine 20 can be exploded at a safe distance by field personnel. When appropriate, transmitter 66 (FIG. 9) can send over antenna 70 an encoded signal generated by encoder 68 . This radiated signal is received by antenna 34 and detected by receiver 36 A. Depending upon the transmitted code, decoder 36 B can issue a signal to fire the booster charge 28 (FIG. 4 ).
Once ignited, booster charge 28 quickly explodes explosive charge 30 . Cover 10 then explodes sending an upward pressure wave, but more importantly, a downward pressure wave. This downward pressure wave depresses cap 16 and explodes land mine 20 .
It will be appreciated that the embodiment of FIG. 6 will operate in substantially the same fashion, except that the explosive chain will start from the side and propagate into the central explosive charge 30 ′. The embodiments of FIGS. 7 and 8 will operate in a manner similar to that of FIGS. 1-5; it is just that the manner of fastening the accessory to the land mine is different.
It is appreciated that various modifications may be implemented with respect to the above described, preferred embodiment. For example, the mine need not have a circular perimeter and may have a perimeter that is square, rectangular, polygonal, elliptical or shaped otherwise. The structure of the cover is may be made of a different number of components than illustrated herein. Also, the structural components of the cover may all be made of a similar material; or different components may be made from different materials, including plastics, metals, ceramics, composite materials, etc. Moreover, the explosive and booster charge can be made of a variety of materials of various shapes that may be positioned in any one of a number of different locations. Also, the encoded signal may be transmitted by radio frequency waves, visible light, infrared energy, acoustic waves, etc. In addition, the disclosed electrical circuit can be modified to include fewer or more features and may be fabricated from discrete electrical components, integrated circuits, etc. Also, the various components can have different sizes and shapes depending upon the desired volume, strength, thermal stability, etc.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. | A self-destruct accessory fits on a mine whose case has a cap that can be depressed to detonate the mine. The accessory has a cover that is sized to fit on the cap. The cover has a plurality of lines for securing the cover to the mine. An explosive charge is mounted upon the cover and a detonator is located adjacent to the explosive charge. A remotely controllable device coupled to the detonator can receive a detonation signal from a remote location to detonate the explosive charge and explosively depress the cap in order to detonate and destroy the mine. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates generally to the purification of steam produced by geothermal sources and more particularly to a process for abating, or removing, the hydrogen sulfide content of the steam.
In many areas of the world, geothermal steam is present at temperatures and pressures sufficient for utilization in turbines for the generation of electricity. Unfortunately, the geothermal steam contains a number of contaminating gases such as carbon dioxide, ammonia, nitrogen and hydrogen sulfide among others.
It has been widely recognized that in many instances, the hydrogen sulfide content of geothermal steam is sufficiently high to make discharge of the steam into the air environmentally unexceptable.
Therefore, it has been the object of many investigators to remove, or abate, the hydrogen sulfide in the geothermal steam in order to make release to the atmosphere an exceptable procedure.
Many methods for removing hydrogen sulfide from gases, have been developed. For example, gas containing hydrogen sulfide may be contacted with activated carbon to catalyze the oxidation of hydrogen sulfide to elemental sulfur and water. Some investigators, for example, see U.S. Pat. No. 4,330,307 issued to Coury in 1982, have developed methods to separate the geothermal steam into a usuable portion, having a low hydrogen sulfide content, and a vent portion or stream, containing the majority of the hydrogen sulfide, the latter being disposed of by reinjection into the ground. Reinjection of this vent portion is not desireable, however, because the H 2 S may migrate and present itself in newly extracted steam.
The process described in U.S. Pat. No. 4,374,106 to Tipton is directed to a process for removing hydrogen sulfide from a geothermal steam by contacting the steam which is mixed with an oxygen containing gas, such as air, with iron oxide and wherein the molar ratio of oxygen to hydrogen sulfide in the steam and oxygen containing gas is at least 10.
It has now been discovered that hydrogen sulfide can be effectively removed from geothermal steam by mixing an oxygen containing gas with the geothermal steam to provide a molar ratio of oxygen to hydrogen sulfide less than 10 and contacting the mixture with iron oxide under specific process conditions. Further, it has been found that elemental sulfur can be recovered on a continuous basis from the geothermal steam after it is contacted with the iron oxide.
More specifically, the process is effective in removing high concentration, of hydrogen sulfide from geothermal steam such as concentrated in the vent stream of processes such as described by Coury (U.S. Pat. No. 4,330,307).
These results are unexpected and not anticipated by the prior art which has been extensively discussed in Tipton et. al. (U.S. Pat. No. 4,374,106).
SUMMARY OF THE INVENTION
In accordance with the present invention a process for removing hydrogen sulfide from geothermal steam includes the steps of introducing an oxygen-containing gas into steam produced by a geothermal source, contacting steam and oxygen containing gas in a contacting stage with iron oxide supported by a carrier resistant to deterioration by the steam and providing the steam and oxygen-containing gas in the contacting stage at a pressure sufficient to enable removal of a majority of hydrogen sulfide from the steam and oxygen containing gas.
The steam comprises water vapor and hydrogen sulfide and has a temperature of at least 250° F. while the oxygen-containing gas is introduced into the steam in an amount to provide a molar ratio of oxygen-to-hydrogen sulfide in the steam and oxygen-containing gas to be less than about 10.
More particularly, the process for removing hydrogen sulfide for geothermal steam in accordance with the present invention includes the steps of removing the steam from the geothermal source, throttling the removed steam to a preselected pressure, straining the throttled steam to remove any large solid particles, separating any liquid droplets from the strained steam, introducing the separated steam and air into a first stage thermal compressor in which the air is compressed and mixed with the steam introduced thereinto. The mixed compressed air and steam are withdrawn from the first stage thermal compressor and introduced into a second stage thermal compressor with additional strained steam to further compress the mixed compressed air and steam to a final mixture of compressed air and steam having a molar ratio of oxygen-to-hydrogen sulfide of less than about 10.
The final mixture is contacted in a reactor with iron oxide supported by pumice and the pressure of the final mixture in the reactor is controlled by means of a back pressure valve. Finally, the steam having a majority of the hydrogen sulfide removed therefrom is removed from the reactor and vented to the atmosphere.
Alternatively, when the concentration of the hydrogen sulfide in the geothermal steam is sufficiently high, elemental sulfur may be separated from the steam and air after it passes through the reactor.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more readily understood by reference to the accompanying drawings in which;
FIG. 1 is a flow diagram of the geothermal hydrogen sulfide removal process in accordance with the present invention utilizing a steam ejector system for compressing the air used in the process as an oxygen-containing gas; and,
FIG. 2 is a flow diagram of the geothermal hydrogen sulfide removal process in accordance with the present invention showing its use in connection with a hydrogen sulfide separation system and showing the separation of elemental sulfur from the steam.
DETAILED DESCRIPTION
As illustrated in FIG. 1, geothermal steam from a geothermal steam well head 10 may be throttled by an inlet steam throttle valve 12 to a preselected pressure. The preselected pressure may vary depending upon the quantity and final utilization of the steam from which hydrogen sulfide has been removed in addition to other parameters including the size and volume capability of the overall process equipment.
Downstream from the throttle valve 12 is a strainer 14 and an in-line steam separator 16, both of which may be of conventional design for removing any large solid particles and liquid droplets from the geothermal steam extracted from the well head 10. The liquids removed by the in-line steam separator 16, which may otherwise cause damage to the thermal compressor 18 are discharged to the atmosphere through a steam trap 20.
After separation of the solids and liquids therefrom, the steam flow rate may be measured by orfice flow meter 22, as it is introduced into the first stage 28 of the thermal compressor, or ejector 18. The two-stage ejector, 18 may be of conventional design and utilizes the steam ejected thereinto for compressing air, which is introduced to the first stage 28, through an air flow meter 30 and an air throttle valve 32.
A distinct advantage is realized through the use of the thermal compressor 18 because part of the geothermal steam to be treated is utilized as the motive force in compressing and mixing the air, which is the oxygen-containing gas, with the geothermal steam.
It is to be appreciated that a separate air compressor (not shown) which may be driven by an electric motor or diesel engine may be utilized to compress the air to the proper pressure, however additional power must be provided therefore and its use will not realize to the fullest extent the advantages and features of the present invention.
The effluent from the first stage 28 is passed through a second stage 36 of the thermal compressor 18 along with additional steam which has been strained to remove solid particles and liquid droplets contained therein. A final mixture of steam and air is then produced by the sccond stage 36 which has a molar ratio of oxygen-to-hydrogen sulfide of less than about 10.
Preferably, when the pressure of the final mixture of steam and air is about 100 psi, the molar ratio of oxygen-to-hydrogen sulfide in the steam and air final mixture is approximately 5.
This is to be distinguished from the process described by Tipton in U.S. Pat. No. 4,374,106 which is directed to a similar process in which the oxygen to hydrogen sulfide ratio in the steam and air final mixture is greater than 10. Tipton found that with oxygen-to-hydrogen sulfide molar ratio less than about 10, the amount of hydrogen removed from the geothermal steam was significantly reduced.
The molar ratio of oxygen-to-hydrogen sulfide is controlled by adjusting the valve 32 and may be monitered by the air flow meter 30.
The final mixture of steam and air is passed through a reactor 40 packed with an iron oxide, which is coated on a carrier suitable for withstanding steam and water at the operating temperatures and pressures without deterioration thereof. Pumice may be suitable for this carrier, but other carriers which may absorb water, expand or crumble are not desirable. The pressure in the reactor 40 may be regulated by a valve, or orifice plate, 42 which is situated down-stream from the reactor 40.
Following removal of the steam having a majority hydrogen sulfide removed therefrom in the reactor 40, the steam is vented to the atmosphere through a rock muffler 44 or the like to reduce the noise level of the exiting steam.
Turning now to FIG. 2 there shown another embodiment of the present invention used in conjunction with a hydrogen sulfide concentrator 50 such as that described by Coury in U.S. Pat. No. 4,330,307 for separating geothermal steam from a well head 52 into clean useable steam and a vent portion, or stream, having a high concentration hydrogen sulfide. Typical operating parameters in terms of gas flow temperatures and pressures are indicated in FIG. 2 adjacent to the lines representing the flow of gases and indicate flow rates expected for providing steam to a 5 mega-watt electric generating plant.
Usually, the distribution of H 2 S between the vent stream and the bulk stream is a function of the fraction of the inlet stream that is vented. According to Coury, about 94% of the inlet H 2 S will be in the vent stream, if 5% of the total inlet stream is vented. That is, the H 2 S content of the vent stream will be about 20 times more concentrated than the inlet stream. Hence, if the concentration of H 2 S in the geothermal steam is about 100 ppm (parts per million), the concentration of H 2 S in the vent portion, or stream, will be about 2000 ppm.
Prior art teachings, as represented by a consultant report prepared by the Stanford Research Institute for the California Resource Conservation and Development Commissioner on page D-6, last paragraph, shows that: "Once the sulfur melts and flows over the surfaces of the granules of absorbent, it will form an impervious film and make the absorbent surface inaccessible to the H 2 S. If the quantity of sulfur in the absorbent bed were sufficient when melting occurred, the molten sulfur could flow through the bed in the direction of gas flow, making the entire bed inoperative. Upon shutdown, the freezing of the sulfur would virtually cement the absorbent mass together, so that it would have to be chipped out. Consequently, the steam temperature must be limited to not more than about 230° F."
Thus, it is apparent that the present invention produces an unexpected result in that it is effective in removing H 2 S from concentrated vent streams, and, additionally useful in recovering elemental sulfur from the vent stream of a Coury type process, the latter adding economic advantage to the invention.
In accordance with the present invention an externally driven compressor 54 may be used to compress air, as an oxygen-containing gas, to approximately 120 psia after which it is mixed with the vent stream flowing from the concentrator 50 in a conduit 56 prior to entering the reactor 58.
As was previously discussed, a reactor back pressure valve 62 may be used to provide the steam and oxygen-containing gas in the reactor, or contacting stage, at a pressure sufficient to cause formation of elemental sulfur and removal of hydrogen sulfide from the steam and oxygen-containing gas.
The elemental sulfur remains as a vapor in the steam and oxygen-containing gas and is passed by the reactor back pressure valve into a conventional venturi scrubber 66 for separating the elemental sulfur from the steam and oxygen-containing gas. The steam and air are then vented through a valve 68 from the scrubber 66 and the sulfur is passed by a pump 70 to a steam heated storage tank 72 for accumulation of the sulfur which is kept in a molten form for later transportation. Part of the sulfur stream may be recirculated through the venturi scrubber 66 via a conduit 76, to serve as the scrubbing medium.
The following examples are provided for the purpose of showing the process of the present invention in removing hydrogen sulfide from geothermal steam.
EXAMPLES
Example 1
247 grams of Iron Oxide catalyst (the catalyst support was Lake County, California Red Pumice) was packed in a stainless steel 316 column of 2.3 cm I.D., The bed height was about 58 cm. The reactor temperature was maintained at 314° F., pressure at 85 psia. steam flow rate=95 grams/hr., Oxygen flow rate=341 cm 3 /min, a gas mixture 160 cm 3 /min (containing 5.41% of H 2 S by volume, the balance is nitrogen). The above three gas streams were well mixed and sent to the top of reactor. This reactor inlet gas stream has H 2 S content 5305 ppm by weight. The O 2 to H 2 S molar ratio is 3.93. The effluent gas from the reactor contained only 912 ppm by weight of H 2 S. Therefore, the H 2 S removal by the reactor was 82.8%.
Example 2
The same reactor used in example 1 was operated under the following conditions:
Steam flow rate=88.6 grams/hr.
Steam pressure=85 psia.
Oxygen flow rate=17.1 cm 3 /min.
H 2 S & N 2 mixture flow rate=80 cm 3 /min (containing 5.41% by volume of H 2 S)
The reactor inlet stream's H 2 S content was 3825 ppm by weight. The oxygen to H 2 S molar ratio was 3.95. The measured H 2 S content in the reactor effluent was only 99 ppm wt. Therefore, the H 2 S removal by the reactor was 97.4%.
Example 3
The same reactor used in example 1 was operated under the following conditions:
Steam flow rate=92.6 grams/hr.
Steam pressure=85 psia.
Oxygen flow rate=13.65 cm 3 /min.
H 2 S & N 2 mixture flow rate=160 cm (containing 5.41% by volume of H 2 S)
The reactor inlet stream had a H 2 S content of 6819 ppm by weight. The O 2 to H 2 S molar ratio was 1.58. The measured H 2 S content in the reactor effluent was 1773 ppm wt. Therefore, the H 2 S removal by the reactor was 74%.
Example 4
The same reactor as in example 1 was operated in the following conditions:
Steam flow rate=125 grams/hr.
Steam pressure=85 psia.
Oxygen flow rate=136.3 cm 3 /min
H 2 S & N 2 mixture flow rate=320 cm 3 /min (containing 5.41% by volume of H 2 S)
This reactor inlet stream has a H 2 S content of 8477 ppm by weight. The O 2 to H 2 S molar ratio was 7.9. The measured reactor effluent H 2 S content was only 34 ppm wt. Therefore, the reactor removed 99.6% of the incoming H 2 S.
Example 5
A demonstration unit located at Geysers area, Lake County, Calif. was operating for 1055 hrs., the reactor size and process conditions are outlined in Table 1.
The results of the field data collected with this demostration reactor are shown in Table 2 which shows a variety of pressure and molar ratios of oxygen to hydrogen sulfide. It is apparent that the results therein, where the molar ratio of oxygen to hydrogen sulfide was greater than 10, confirm the results of Tipton in U.S. Pat. No. 4,374,106.
Surprisingly and contrary to the teaching of Tipton, the process of the present invention is effective in removing hydrogen sulfide from geothermal steam at molar ratio of oxygen to hydrogen sulfide of significately less than 10.
Importantly in run No. 2015 the reactor effluent was condensed and a 96 gram liquid example was collected which contained yellowish solids. After filtration and separating the yellow solids on electron microprobe analysis identified the yellow solids to be 99% sulfur.
Although there has been described hereinabove a specific process for removing hydrogen sulfide from geothermal steam directly or from the vent stream of an H 2 S separation, in accordance with the invention for purposes of illustrating the manner in which the invention may be used to advantage, it will be appreciated that the invention is not limited thereto. According by, any and all modifications, variations or equivalant arrangements which may occur to those skilled in the art should be consider to be within the scope of the invention as defined in the appended claims.
TABLE 1______________________________________Reactor Dimension 42 inch diameterCatalyst Volume 48 ft.sup.3Total duration of run 1060 hoursCatalyst support Scoriaceous Volcanic Rock (Lake Coundy Red Pumice)Steam Flow Rate, lb/hr 4,900-11,783Reactor Pressure, PSIA 35-129Inlet H.sub.2 S Content, ppm wt 215-1,055Inlet H.sub.2 S concentration 0.9 × 10.sup.-6 -6.6 × 10.sup.-6lb-mole/ft.sup.3Molar ratio O.sub.2 to H.sub.2 S 0-48H.sub.2 S Removal 26%-99.2%Contact time based on 3.0-5.9total flow, secondSuperficial linear 0.8-1.7Velocity, ft/secH.sub.2 S weight space time 1.3 × 10.sup.4 -9.0 × 10.sup.4lb-hour/lb-molePressure drop across 1-3reactor, PSISteam (inlet) temperature, °F. 279-352______________________________________
TABLE 2______________________________________ RE- H.sub.2 S CON- ACCU- ACTOR TENT IN MOLAR % RE- MU- PRES- REACTOR RATIO MOVALRUN LATED SURE INLET, O.sub.2 TO OFNO. HOURS PSIA PPM WT H.sub.2 S H.sub.2 S______________________________________1010 28. 35. 509. 15.4 79.01049 108. 111. 276. 30.0 91.31106 223. 111. 692. 13.3 82.91123 257. 112. 786. 6.7 77.01149 310. 111. 1055. 9.4 64.41174 354. 112. 308. 19.0 87.51212 435. 110. 823. 8.6 64.51234 479. 109. 658. 7.6 73.61254 600. 117. 902. 3.7 54.31308 774. 71. 401. 21.7 80.81315 818. 71. 700. 12.8 78.92005 845. 97. 271. 16.1 97.82015 938. 95. 262. 5.0 97.32020 1006. 92. 292. 0.0 26.02026 1055 53. 267. 6.8 59.0______________________________________ | A process for removing hydrogen sulfide from geothermal steam and from vent streams, or concentrated portions produced by a hydrogen sulfide separation process, includes the steps of introducing an oxygen-containing gas, such as air into the steam, or vent stream, and thereafter contacting the steam and oxygen-containing gas in a contacting stage with iron oxide supported by a carrier resistant to deterioration. The steam having a temperature of at least 250° F. is mixed with oxygen to provide a molar ratio of oxygen-to-hydrogen sulfide ratio of less than about 10. During the contacting stage the pressure of the steam and oxygen-containing gas is maintained at a pressure sufficient to enable removal of a majority of the hydrogen sulfide from the steam and oxygen-containing gas. | 8 |
BACKGROUND OF THE INVENTION
The present invention concerns a microwave dielectric ceramic composition and, more in particular, it relates to a microwave dielectric ceramic composition having a temperature coefficient of a resonance frequency (hereinafter simply referred to as τf) varied generally within a practical characteristic range while maintaining a practical unload Q (hereinafter simply referred to Qu) and a greatly improved specific dielectric constant (hereinafter simply referred to as εr).
The present invention also concerns a microwave dielectric ceramic composition in which each of the characteristic is balanced at a practical level.
The present invention further concerns a microwave dielectric ceramic composition in which εr and Qu are controlled generally within a practical characteristic range while maintaining τf at a practical high level and each of the characteristics is balanced at a high level.
The present invention further concerns a microwave dielectric ceramic composition in which εr, Qu and τf are controlled generally within a practical characteristic range and each of the characteristics is maintained in a well balanced state.
The present invention is utilized for impedance matching or the like of dielectric resonators, microwave integrated circuit substrate, various kinds of microwave circuits in a microwave region and it is particularly suitable to LC filter materials.
Generally, LC filter materials, dielectric resonators, dielectric substrates used in a region of high frequency waves such as microwaves or milliwaves are required to have high εr and high flu, as well as small absolute value for the temperature coefficient of the resonance frequency.
Namely, since the dielectric loss of a microwave dielectric ceramic composition (hereinafter simply referred to as dielectric ceramic composition) tends to increase as the working frequency becomes higher, a dielectric ceramic composition having large εr and Qu in a microwave region is desired.
For such a dielectric ceramic composition, a composition belonging to a composite perovskite structure such as Ba(Zn 1/3 Ta 2/3 )O 3 or Ba(Mg 1/3 Ta 2/3 )O 3 or BaO--TiO 2 system composition has been used in recent years, but any of them requires a high sintering temperature of 1300° C. or higher.
Such a high sintering temperature requires greater power electric power consumption during sintering to result in a drawback of causing a disadvantage in view of production cost or productivity.
Further, in a case of sintering together with a conductor having a low melting point as an electrode, for example, silver (melting point: 961° C.) or copper (melting point: 1083° C.) as in an LC filter or a strip line filter, it is particularly advantageous that the sintering temperature is lower than the melting point of the conductor. Accordingly, a material sinterable at a temperature as low as possible is demanded.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a dielectric ceramic composition capable of having τf varying generally within a practical range and high εr while maintaining high Qu by a composition comprising a main ingredient of Bi 2 O 3 --Nb 2 O 5 --Ta 2 O 5 system and a predetermined amount of V 2 O 5 added and incorporated thereto.
The present inventor has made various studies on Bi 2 O 3 ---Nb 2 O 5 --Ta 2 O 5 system compositions having τf varied generally within a practical characteristic range while maintaining high Qu, having high εr and capable of being produced by sintering at a low temperature and, as a result, has accomplished the present invention based on the discovery that the foregoing object can be attained by varying the ratio between Nb 2 O 5 in the above-mentioned composition and, further, adding a predetermined amount of V 2 O 5 thereto.
That is, the dielectric ceramic composition according to the present invention comprises a composition represented by xBi 2 O 3 -(1-x) (yNb 2 O 5 -(1-y)Ta 2 O 5 ) in which 0.45≦x≦0.55 and 0<y<1.0 as a main ingredient, to which not more than 0.8 parts by weight (not including 0 part by weight) of V 2 O 5 s is added and incorporated based on 100 parts by weight of the xBi 2 O 3 -(1-x) (yNb 2 O 5 -(1-y)Ta 2 O 5 ).
In the above-mentioned invention, x is defined as 0.45 to 0.55, because Qu is too small if x is less than 0.45 or exceeds 0.55. Further, y is within a range: 0<y<1.0. If Nb 2 O 5 is not present (y=0), the absolute value for τf tends to increase (decrease in a negative direction) and εr tends to decrease. If N 2 O 5 is present even in a small amount, εr which is important for LC filter material tends to be improved. On the other hand if y is at 1.0, εr tends to decrease and Qu tends to decrease as y increases.
Further, the addition ratio of V 2 O 5 is defined as not more than 0.8% by weight (not including 0% by weight), because Qu tends to decrease if it is added in excess of 0.8% by weight although the addition of V 2 O 5 can lower the sintering temperature. Further, a case in which α is 0% by weight, that is, of V 2 O 5 is not added is excluded, because this makes sintering insufficient and lowers each of the characteristics.
The addition amount of V 2 O 5 at 0.4% by weight is more preferred since Qu increases much higher as compared with the case of addition of 0.8% by weight, 0.6% by weight and 0.2% by weight (Nos. 5-8 compared with Nos. 13-16, Nos. 9-12 and 1-4 in Table 1).
In particular, it is preferred that x is from 0.47 to 0.53, y is from 0.4 to 0.8 and α is from 0.4 to 0.6, since each physical property is balanced. In this case, εr is from 42.9 to 47.7, Qu is from 790 to 1490 and τf is from -46.4 to -16.2 ppm/°C.
Further, the dielectric ceramic composition of the present invention is produced as described below. Specifically, bismuth oxide (III) powder, niobium oxide (V) powder, tantalum oxide (V) powder and vanadium oxide (V) powder are mixed so as to provide a composition comprising a composition represented by xBi 2 O 3 -(1-x) (yNb 2 O 5 -(1-y)Ta 2 O 5 in which 0.45≦x≦0.55 and 0<y<1.0 as a main ingredient, to which not more than 0.8 parts by weight (not including 0 part by weight) of V 2 O 5 is added and incorporated based on 100 parts by weight of the xBi 2 O 3 -(1-x) (yNb 2 O 5 -(1-y)Ta 2 O 5 ) and then calcined to prepare a calcined powder, which is pulverized, molded into a predetermined shape and then sintered at 860°-950° C.
The sintering temperature is defined as within 860° to 950° C., because Qu decreases and τf increases excessively in the negative direction out of the temperature range. Further, low temperature sintering is particularly preferred in a case of sintering simultaneously with a conductor such as for an LC filter. The sintering can be carried out either in an ambient atmosphere or a reducing atmosphere.
In the dielectric ceramic composition according to the present invention, τf can be varied widely within a practical characteristic range while maintaining Qu at a level with no practical problem by setting each of the oxides a predetermined ratio in the Bi 2 O 3 --Nb 2 O 5 --Ta 2 O 5 system, to which a predetermined amount of V 2 O 5 is added. Further, a dielectric ceramic composition having extremely high εr and suitable to LC filter material can be obtained. Further, the dielectric ceramic composition according to the present invention can be prepared by sintering at a relatively low temperature as 860° to 950° C. Such low temperature sintering is particularly advantageous in a case of the LC filter which is sintered simultaneously with a conductor.
An object of the present invention is to provide a dielectric ceramic composition in which (Qu and τf are controlled within a wide characteristic range while maintaining εr at a high and each of the characteristics is balanced at a practical level, by with a composition comprising Bi(NbTa)O 4 as a main ingredient to which V 2 O 5 and PbO is added each in a predetermined amount.
The present inventor has made various studies on Bi(NbTa)O 4 system compositions having Qu and τf cotroled within a wide practical characteristic range while maintaining high εr and capable of being produced by sintering at a low and wide temperature and, as a result, has accomplished the present invention based on the discovery that the foregoing object can be attained by varying the ratio between Nb 2 O 5 and Ta 2 O 5 in the above-mentioned composition and, further, adding a predetermined amount of V 2 O 5 and PhO thereto.
The dielectric ceramic composition of the present invention comprises a composition represented by Bi(NbxTa1-x)O 4 in which 0<x≦0.96 as a main ingredient to which not more than 5% by weight (not including 0% by weight) of V 2 O 5 and not more than 2% by weight (not including 0% by weight) of PbO are added and incorporated based on 100% by weight of Bi(NbxTa1-x)O 4 .
In the above-mentioned invention, x is defined as: 0<x≦0.96, because the Ta 2 O 5 ingredient is substantially absent if x exceeds 0.96, making it difficult to control εr and τf.
Further, the addition amount of V 2 O 5 is defined as greater than 0 and not more than 5% by weight, because addition in excess of 5% by weight can not provide any further effect and it rather results in deterioration of other characteristics such as Qu, although the sintering temperature can be lowered by the addition of V 2 O 5 , and because sintering is insufficient to lower each of the characteristics if V 2 O 5 is not added. The addition amount of V 2 O 5 within a range from 0.2 to 2.0% by weight is more preferred since a practical dielectric ceramic composition showing well balanced in each of the characteristics can be obtained.
Further, the addition amount of PbO is greater than 0 and not more than 2% by weight. Addition of PbO can increase εr and Qu as compared with a case of not adding PbO at all. However, although εr is improved in proportion with the addition amount of PbO, Qu reaches a peak at the addition amount of 0.2% by weight and tends to reduce beyond the peak, τf tends to increase in the negative direction in proportion with the addition of PbO. This trend is remarkable if the addition amount is as great as 1 to 2% by weight. Accordingly, for obtaining a dielectric ceramic composition well balanced in each of the characteristics and having a high level, it is preferred that the addition amount of PbO is within a range from 0.1 to 1.0% by weight.
Further, it is preferred that x is from 0.2 to 0.9 (table 1 and 2), the addition amount of V 2 O 5 is from 0.2 to 2.0% by weight and the addition amount of PbO is from 0.2 to 0.6% by weight (table 3). In this case, εr is from 45 to 48, Qu is from 960 to 1640 (at from 3.6 to 4.0 GHz) and τf is from -47 to -36 ppm/°C.
Further, the dielectric ceramic composition of the present invention is produced as described below. The predetermined metal oxide powders are mixed so as to provide a predetermined composition and then calcined to prepare a calcined powder, which is pulverized, molded into a predetermined shape and then sintered at 850°-950° C. The sintering temperature is defined as within 850° to 950° C., because Qu decreases and τf increases excessively in the negative direction out of the temperature range. Further, low temperature sintering is particularly preferred in a case of sintering simultaneously with a conductor such as for an LC filter. The sintering can he carried out either in an ambient atmosphere or a reducing atmosphere.
In the dielectric ceramic composition according to the present invention, a dielectric ceramic composition well balanced in each of the characteristics such as Qu and τf while maintaining practically high εr and suitable to LC filter material can be obtained by setting each of the oxides at a predetermined ratio in the Bi(NbTa)O 4 system, to which V 2 O 5 and PbO are added each in a predetermined amount. Further, a composition of particularly excellent performance can he obtained in a range of relatively lower addition amount of PbO. Further, the dielectric ceramic composition according to the present invention can he prepared by sintering at a relatively low and wide temperature as 850° to 950° C. Such low temperature sintering is particularly advantageous in a case of the LC filter which is sintered simultaneously with a conductor.
An object of the present invention is to provide a dielectric ceramic composition in which εr and Qu are controlled widely within a practical characteristic range while maintaining τf at a practically high level and each of the characteristics is balanced at a high level, by a composition comprising a Bi(NbTa)O 4 system as a main ingredient to which V 2 O 5 and MnO 2 are added and incorporated each by a predetermined amount.
The present inventor has made various studies on Bi(NbTa)O 4 system compositions having εr and Qu cotroled widely within a practical characteristic range while maintaining practical high τf and capable of being produced by sintering at a low and wide temperature and, as a result, has accomplished the present invention based on the discovery that the foregoing object can be attained by varying the ratio between Nb 2 O 5 and Ta 2 O 5 in the above-mentioned composition and, further, adding a predetermined amount of V 2 O 5 and MnO 2 thereto.
The dielectric ceramic composition according to the present invention comprises a composition represented by Bi(NbxTa1-x)O 4 in which 0<x ≦0.96 as a main ingredient, to which not more than 5% by weight (not including 0% by weight) of V 2 O 5 and not more than by weight (not including 0% by weight) of MnO 2 are added and incorporated based on 100% by weight of Bi(NbxTa1-x)O 4 . Further, in the present invention, the addition amount of MnO 2 may be from 0.1 to 1.0% by weight based on 100% by weight of Bi(NbxTa1-x)O 4 .
In the above-mentioned invention, x is defined as: 0<x≦0.96, because the Ta 2 O 5 ingredient is substantially absent if x exceeds 0.96, making it difficult to control εr and τf.
Further, the addition amount of V 2 O 5 is defined as greater than 0 and not more than 5% by weight, because addition in excess of 5% by weight can not provide any further effect and it rather results in deterioration of other characteristics such as Qu, although the sintering temperature can be lowered by the addition of V 2 O 5 , and because sintering is insufficient to lower each of the characteristics if V 2 O 5 is not added. The addition amount of V 2 O 5 within a range from 0.2 to 2.0% by weight is more preferred since a practical dielectric ceramic composition showing well balanced in each of the characteristics can be obtained.
The addition amount of MnO 2 is more than 0 and not more than 2% by weight and the addition of MnO 2 can improve all of τf, εr and Qu with a certain exception as compared with a case of not adding MnO 2 at all. However, although εr is improved linearly in proportion with the addition mount of MnO 2 , τf rather decreases depending on the case as the addition amount of τf exceeds 1% by weight, particularly, as the sintering temperature goes higher, while Qu reaches a peak at the addition amount of 0.2% by weight and tends to lower beyond the peak. Accordingly, for obtaining a dielectric ceramic composition well balanced in each of the characteristics at a high level, it is preferred that the addition amount of MnO 2 is within a range from 0.1 to 1.0% by weight
Further, it is preferred that x is from 0.2 to 0.9 (tables 1 and 2), the addition amount of V 2 O 5 is from 0.2 to 2.0% by weight and the addition amount of MnO 2 is from 0.1 to 0.6% by weight (table 4). In this case, εr is from 45 to 47, Qu is from 970 to 1640 (at from 3.6 to 3.9 GHz) and τf is from -14 to -5.5 ppm/°C.
Further, the dielectric ceramic composition of the present invention is produced as described below. The predetermined metal oxide powders are mixed so as to provide a predetermined composition and then calcined to prepare a calcined powder, which is pulverized, molded into a predetermined shape and then sintered at 850°-950° C. The sintering can be carried out either in an ambient atmosphere or a reducing atmosphere.
The sintering temperature is defined as within 850° to 950° C., because Qu decreases and τf increases excessively in the negative direction out of the temperature range. Further, low temperature sintering is particularly preferred in a case of sintering simultaneously with a conductor such as for an LC filter.
In the dielectric ceramic composition according to the present invention, a dielectric ceramic composition well balanced in each of the characteristics such as εr and Qu while maintaining practically high τf and suitable to LC filter material can be obtained by setting each of the oxides at a predetermined ratio in the Bi(NbTa)O 4 system, to which V 2 O 5 and MnO 2 are added each in a predetermined amount. Further, a composition of particularly excellent performance can be obtained in a range of relatively lower addition amount of MnO2. Further, the dielectric ceramic composition according to the present invention can be prepared by sintering at a relatively low and wide temperature as 850° to 950° C. Such low temperature sintering is particularly advantageous in a case of the LC filter which is sintered simultaneously with a conductor.
An object of the present invention is to provide a microwave dielectric ceramic composition in which εr, Qu and τf are controlled widely within a practical characteristic range and each of the characteristics is maintained in a well balanced state, by a composition comprising Bi(NbTa)O 4 system as a main ingredient to which V 2 O 5 and TiO 2 are added each in a predetermined amount.
The present inventor has made various studies on Bi(NbTa)O 4 system compositions having εr, Qu and τf cotroled within a wide practical characteristic range and capable of being produced by sintering at a low temperature and, as a result, has accomplished the present invention based on the discovery that the foregoing object can be attained by varying the ratio between Nb 2 O 5 and Ta 2 O 5 in the above-mentioned composition and, further, adding a predetermined amount of V 2 O 5 and TiO 2 thereto, and in particular the discovery that the foregoing object can be attained by cotroling τ f by an addition of TiO 2 .
The dielectric ceramic composition according to the present invention comprises a composition represented by Bi(NbxTa1-x)O 4 ) in which 0<x≦0.96 as a main ingredient to which not more than 2% by weight (not including 0% by weight) of V 2 O 5 and not more than 1% by weight (not including 0% by weight) of TiO 2 are added and incorporated based on 100% by weight of the Bi(NbxTa1-x)O 4 ).
In the above-mentioned invention, x is defined as: 0<x≦0.96, because the Ta 2 O 5 ingredient is substantially absent if x exceeds 0.96, making it difficult to control εr and τf.
By varying the addition amount of Ta 2 O 5 , control for εr and τf is facilitated and, particularly, by increasing the addition amount of Ta 2 O 5 , εr and Qu can be increased.
Further, the addition amount of V 2 O 5 is determined as more than 0 but not more than 2% by weight, because V 2 O 5 functions as a sintering aid and, accordingly, can lower the sintering temperature and stabilize the performance by the addition, but addition in excess of 2% by weight decreases Qu and τf, whereas no addition of V 2 O 5 makes sintering insufficient and decreases each of the characteristics. The addition amount of V 2 O 5 , particularly, within a range from 0.3 to 0.5% by weight (particularly around 0.4% by weight) is more preferred since a practical dielectric ceramic composition well balanced in each of the characteristics is obtained.
Further, the addition amount of TiO 2 is defined as not more than 1% by weight, because each of the characteristics decreases remarkably if the addition amount exceeds about 1% by weight. TiO 2 has an effect of transferring τf from a negative to positive direction by the addition and an addition amount within a range from 0.1 to 0.3% weight (particularly, 0.2% by weight) is more preferred since a practical dielectric ceramic composition well balanced in each of the characteristics is obtained.
Further, x is from 0.6 to 0.96, the addition amount of V 2 O 5 may be from 0.2 to 1.0% by weight and the addition amount of TiO 5 may be from 0.1 to 0.6% by weight. This is because well balanced performance can be obtained for εr, Qu and τf within such a range of addition. Further, a practical balanced performance such as τf from -30 to 0 ppm/°C., Qu from 510 to 1160, εr from 42 to 58 can be obtained with the above-mentioned composition.
Further, the dielectric ceramic composition of the present invention is produced as described below. The predetermined metal oxide powders are mixed so as to provide a predetermined composition and then calcined at 600°-800° C. to prepare a calcined powder, which is pulverized, molded into a predetermined shape and then sintered at 875°-950° C. The sintering can be carried out either in an ambient atmosphere or a reducing atmosphere.
The sintering temperature is defined as within 875° to 950° C., because a sintering temperature of less than 875° C. may make sintering insufficient, a sufficient sintering density is ensured by sintering within this sintering range and the performance is stabilized. Further, low temperature sintering is particularly preferred in a case of sintering simultaneously with a conductor such as for an LC filter.
In the dielectric composition according to the present invention, εr, Qu and τf are within a practical characteristic range and each of the characteristics is maintained in a well balanced state. Accordingly, it is suitable to the LC filter material.
Further, the dielectric ceramic composition according to the present invention can be prepared by sintering at a relatively low and wide temperature as 875° to 950° C. Such low temperature sintering is particularly advantageous in a case of the LC filter which is sintered simultaneously with a conductor.
An object of present invention is to provide a microwave dielectric ceramic composition in which εr, Qu and τf are controlled within a wide practical characteristic range and each of the characteristics is maintained in a well balanced state, by a composition comprising a Bi(NbTa)O 4 system as a main ingredient, to which V 2 O 5 and MnO 2 , as well as TiO 2 or PbO are added and incorporated each in a predetermined amount.
The present inventor has made various studies on Bi(NbTa)O 4 system compositions having εr, Qu and τf cotroled widely within a practical characteristic range and capable of being produced by sintering at a low temperature and, as a result, has accomplished the present invention based on the discovery that the foregoing object can he attained by varying the ratio between Nb 2 O 5 and Ta 2 O 5 in the above-mentioned composition and, further, adding a predetermined amount of V 2 O 5 , MnO 2 and TiO 2 (or PbO) thereto.
The dielectric ceramic composition according to the present invention comprises a composition represented by Bi(NbxTa1-x)O 4 in which 0<x≦0.96 as a main ingredient, to which not more than 2% by weight (not including 0% by weight) of V 2 O 5 , not more than 2% by weight (not including 0% by weight) of MnO 2 and not more than 0.7% by weight (not including 0% by weight) of TiO 2 are added and incorporated based on 100% by weight of Bi(NbxTa 1 -x)O 4 .
In the above-mentioned invention, x is defined as: 0<x≦0.96, because the Ta 2 O 5 ingredient is substantially absent if x exceeds 0.96, making it difficult to control εr and τf.
Since V 2 O 5 functions as a sintering aid, addition thereof can lower the sintering temperature and stabilize the performance. If the addition amount of V 2 O 5 exceeds 2% by weight, it decreases Qu and τf, whereas if V 2 O 5 is not added, sintering is insufficient to decrease each of the characteristics. An addition amount of V 2 O 5 , particularly, from 0.2 to 1.0% by weight (preferably, from 0.3 to 0.5% by weight, more preferably, about 0.4% by weight) is more preferred since a practical dielectric ceramic composition well balanced in each of the characteristics can be obtained. For instance, at the addition amount: (1) from 0.2 to 1.0% by weight (MnO 2 and TiO 2 : both 0.2% by weight, x: 0.8), εr is 46.6 to 47.9, Qu is 890 to 1300 as τf is -10.91 to -2.45 ppm/°C. and (2) addition amount of 0.4% by weight (MnO 2 and TiO 2 : both 0.2% by weight, x: 0.8), εr is 47.1, Qu is 1325 and τf is -7.46 ppm/°C.
Further, both of Qu and τf are improved by the addition of MnO 2 up to 0.4% by weight. Accordingly, since MnO 2 has an effect of transferring τf from negative to positive direction within this addition range, it is effective to adjust τf from negative to positive direction.
On the other hand, if it is added by more than 2% by weight, it is not preferred since tends to decrease greatly. Particularly, an addition amount of not more than 1.0% by weight is more preferred since a practical dielectric ceramic composition well balanced in each of the characteristics can be obtained. For instance, at the addition amount of from 0.2 to 1.0% by weight (V 2 O 5 ; 0.4% by weight, TiO 2 ; 0.2% by weight, x; 0.8), εr is 47.0 to 47.5, Qu is 900 to 1440 and τf is -6.0 to -11.1 ppm/°C.
Further, the addition amount of TiO 2 is defined as not more than 0.7% by weight, because Qu is decreases greatly and τf transfers in the positive direction apart from 0 if the addition amount is more than 0.7% by weight. Since TiO 2 has an effect of transferring τf from negative to positive direction by the addition, it is effective for adjusting τf from negative to positive direction. Particularly, a practical dielectric ceramic composition well balanced in each of the characteristics can be obtained with an addition amount of 0.1 to 0.2% by weight. For instance, at the addition amount from 0.1 to 0.2% by weight (V 2 O 5 ; 0.4% by weight, MnO 2 : 0.2% by weight and x: 0.8), εr is46.4 to 47.1, Qu is 1320 to 1490 and τf is -8.8 to -7.5 ppm/°C.
Further, it is possible to set the addition amount of V 2 O 5 as 0.2 to 1.0% by weight, the addition amount of MnO 2 of not more than 1.0% by weight and the addition amount of TiO 2 of not more than 0.4% by weight and x as 0.8 to 0.96, because the performance is well balanced in this case. For instance, it is possible to attain τf: -12 to +7 ppm/°C., Qu: 800 to 1600 and εr: 45 to 50.
Further, the dielectric ceramic composition of the present invention is produced as described below. The predetermined metal oxide powders are mixed so as to provide a predetermined composition and then calcined at 600°-800° C. to prepare a calcined powder, which is pulverized, molded into a predetermined shape and then sintered at 850°-950° C. The sintering can be carried out either in an ambient atmosphere or a reducing atmosphere.
The sintering temperature is defined as within 850° to 950° C., because Qu decreases and τf increases excessively in the negative direction out of the temperature range. Further, low temperature sintering is particularly preferred in a case of sintering simultaneously with a conductor such as for an LC filter.
A dielectric ceramic composition according to the present invention comprises a composition represented by Bi(NbxTa1-x)O 4 , in which 0<x≦0.96 as a main ingredient, to which 0.2 to 1% by weight of V 2 O 5 , not more than 1% by weight (not including 0% by weight) of MnO 2 and not more than 0.5% by weight (not including 0% by weight) of PbO are added and incorporated.
The reason why x is defined as 0<x≦0.96 in this invention is identical with the reason explained for the first invention.
Further, since V 2 O 5 functions as a sintering aid, addition thereof can lower the sintering temperature and stabilize the performance. If the addition amount exceeds 1% by weight, Qu decreases and it decreases remarkably to about 510 at the addition amount of 3% by weight. Further, if the addition amount exceeds 1% by weight, τf is not more than -24 ppm/°C., that is, increases toward the negative direction. Further, if is not added sintering is insufficient and Qu decreases, which is not desired. The addition amount of V 2 O 5 , particularly, from 0.4 to 0.8% by weight is more preferred since a practical dielectric ceramic composition well balanced in each of the characteristics can be obtained. For instance, (1) at the addition amount of from 0.4 to 0.8% by weight (x: 0.8, MnO 2 and PbO: both 0.2% by weight), εr is 44.9 to 46.8, Qu is 1460 to 1950 as τf is -14.5 to -1.7 ppm/°C. and (2) addition amount of 0.6% by weight (x: 0.8, MnO 2 and PbO: both 0.2% by weight), εr is 46.5, Qu is 1430 and τf is -1.75 ppm/°C. and τ f is nearly 0.
Further, addition of MnO 2 can increase εr and τf. Since the addition of this ingredient has a function of transferring particularly, τf from negative to positive direction, so that it is effective for adjusting τf from negative to positive direction. On the other hand, if addition amount is more than 1% by weight, Qu tends to decrease remarkably, which it is not preferred. Particularly, the addition amount of MnO 2 from 0.2 to 0.4% by weight (V 2 O 5 ; 0.4% by weight, PbO; 0.2% by weight and x; 0.8) is preferred since this can provide a practical dielectric ceramic composition well balanced in each of the characteristics as εr: 46.8 to 47.9, Qu: 1351 to 1465 and τf: -6.3 to -2.1 ppm/°C.
Further, the addition amount of PbO is defined as not more than 0.5% by weight, because Qu and τf decrease greatly if the addition amount is more than 0.5% by weight. Since PbO has an effect of transferring, particularly, τf from positive to negative direction by the addition, it is effect ire for adjusting τf from positive to negative direction. Particularly, the addition amount of PbO from 0.2 to 0.4% by weight (V 2 O 5 : 0.4% by weight, MnO 2 : 0.2% by weight and x: 0.8) is more preferred since a practical dielectric ceramic composition well balanced in each of the characteristics can be obtained as εr: 46.8 to 47.4, Qu: 1293 to 1465, τf; -13.2 to -6.3 ppm/°C.
Further, it is possible to set the addition amount of V 2 O 5 as 0.3 to 0.8% by weight, the addition amount of MnO 2 as 0.1 to 1.0% by weight, the addition amount of PbO as not more than 0.4% by weight and x as from 0.8 to 0.96, because the performances are well balanced in this case. For instance, it is possible to attain τf; -15 to +4 ppm/°C., Qu: 1000 to 2000 and εr: 44-49.
Further, the dielectric ceramic composition of the present invention is produced as described below. The predetermined metal oxide powders are mixed so as to provide a predetermined composition and then calcined at 600°-800° C. to prepare a calcined powder, which is pulverized, molded into a predetermined shape and then sintered at 850°-950° C.
The sintering temperature is defined as within 850° to 950° C., because Qu decreases and τf increases excessively in the negative direction out of the temperature range. Further, low temperature sintering is particularly preferred in a case of sintering simultaneously with a conductor such as for an LC filter. The sintering can be carried out either in an ambient atmosphere or a reducing atmosphere.
In the dielectric ceramic composition according to the present invention, εr, Qu and τf are within a practical characteristic range and each of the characteristics is maintained in a well balanced state. Accordingly, it is suitable to the LC filter material.
Further, the dielectric ceramic composition according to the present invention can be prepared by sintering at a relatively low and wide temperature as 850° to 950° C. Such low temperature sintering is particularly advantageous in a case of the LC filter which is sintered simultaneously with a conductor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing a relation between x and εr in (the main ingredient represented by xBi 2 O 3 -(1-x) (0.8Nb 2 O 5 -0.2Ta 2 O 5 )+0.4% by weight of V 2 O 5 ).
FIG. 2 is a graph showing a relation between x and Qu in (a main ingredient represented by xBi 2 O 5 -(1-x) (0.8Nb 2 O 5 -0.2Ta 2 O 5 )+0.4% by weight of V 2 O 5 ).
FIG. 3 is a graph showing a relation between x and τf in (the main ingredient represented by xBi 2 O 3 -(1-x) (0.8Nb 2 O 5 -0.2Ta 2 O 5 )+0.4% by weight of V 2 O 5 ).
FIG. 4 is a graph showing a relation between y of the main ingredient represented by 0.5Bi 2 O 3 -0.5(yNb 2 O 5 -(1-y) Ta 2 O 5 ) and the addition amount of (α) of V 2 O 5 , and εr.
FIG. 5 is a graph showing a relation between y of the main ingredient represented by 0.5Bi 2 O 3 -0.5(yNb 2 O 5 -(1-y) Ta 2 O 5 ) and the addition amount (α) of V 2 O 5 , and Qu.
FIG. 6 is a graph showing a relation between y of the main ingredient represented by 0.5Bi 2 O 5 -0.5(yNb 2 O 5 -(1-y) Ta 2 O 5 ) and the addition amount (α) of V 2 O 5 , and τf.
FIG. 7 is a graph showing a relation between the sintering temperature and the addition amount (δ) of PbO, and εr in (the main ingredient represented by Bi(Nb 0 .6 Ta 0 .4)O 0 .4)O 4 +0.4% by weight of V 2 O 5 ).
FIG. 8 is a graph showing a relation between the sintering temperature and the addition amount (δ) of PbO, and Qu in (the main ingredient represented by Bi(Nb 0 .6 Ta 0 .4)O 4 +0.4% by weight of V 2 O 5 ).
FIG. 9 is a graph showing a relation between the sintering temperature and the addition amount (δ) of PhO, and τf in (the main ingredient represented by Bi(Nb 0 .6 Ta 0 .4)O 4 +0.4% by weight of V 2 O 5 ).
FIG. 10 is a graph showing a relation between the sintering temperature and the addition amount (δ) of PbO, and the sintering density in (the main ingredient represented by Bi(Nb 0 .6 Ta 0 .4)O 4 +0.4% by weight of V 2 O 5 ).
FIG. 11 is a graph showing a relation between the addition amount (δ) of PbO and εr in (the main ingredient represented by Bi(Nb 0 .6 Ta 0 .4)O 4 +0.4% by weight of V 2 O 5 ) and in case of 900° C. of sintering temperature.
FIG. 12 is a graph showing a relation between the addition amount (δ) of PbO and Qu in (the main ingredient represented by Bi(Nb 0 .6 Ta 0 .4)O 4 +0.4% by weight of V 2 O 5 ) and in case of 900° C. of sintering temperature.
FIG. 13 is a graph showing a relation between the addition amount (δ) of PbO and τf in (the main ingredient represented by Bi(Nb 0 .6 Ta 0 .4)O 4 +0.4% by weight of V 2 O 5 ) and in case of 900° C. of sintering temperature.
FIG. 14 is a graph showing a relation between the addition amount (δ) of PbO and the sintering density in (the main ingredient represented by Bi(Nb 0 .6 Ta 0 .4)O 4 +0.4% by weight of V 2 O 5 ) and in case of 900° C. of sintering temperature.
FIG. 15 is a graph showing a relation between the sintering temperature and the addition amount (β) of MnO 2 , and εr in (the main ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.4% by weight of V 2 O 5 ).
FIG. 16 is a graph showing a relation between the sintering temperature and the addition amount (β) of MnO 2 , and Qu in (the main ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.4% by weight of V 2 O 5 ).
FIG. 17 is a graph showing a relation between the sintering temperature and the addition amount (β) of MnO 2 , and τf (the main ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.4% by weight of V 2O 5 ).
FIG. 18 is a graph showing a relation between the sintering temperature and the addition amount (β) of MnO 2 , and the sintering density in (the main ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.4% by weight of V 2 O 5 ).
FIG. 19 is a graph showing a relation between the addition amount (β) of MnO 2 and εr in (the main ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.4% by weight of V 2 O 5 ) and in case of 900° C. of sintering temperature.
FIG. 20 is graph showing a relation between the addition amount (β) of MnO 2 and Qu in (the main ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.4% by weight of V 2 O 5 ) and in case of 900° C. of sintering temperature.
FIG. 21 is a graph showing a relation between the addition amount (β) of MnO 2 and τf in (the main ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.4% by weight of V 2 O 5 ) and in case of 900° C. of sintering temperature.
FIG. 22 is a graph showing a relation between the addition amount (β) of MnO 2 and the sintering density in (the ma in ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.4% by weight of V 2 O 5 ) and in case of 900° C. of sintering temperature.
FIG. 23 is a graph showing a relation between the addition amount (γ) of TiO 2 and εr in (the main ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.4% by weight of V 2 O 5 ) and in case of 900° C. of sintering temperature.
FIG. 24 is a graph showing a relation between the addition amount (γ) of TiO 2 and Qu in the ceramic composition and the sintering temperature in FIG. 23.
FIG. 25 is a graph showing a relation between the addition amount (γ) of TiO 2 and τf in the ceramic composition and the sintering temperature in FIG. 23.
FIG. 26 is a graph showing a relation between the addition amount (γ) of TiO 2 and the sintering density in the ceramic composition and the sintering temperature in FIG. 23.
FIG. 27 is a graph showing a relation between the addition amount (α) of V 2 O 5 and εr in (the main ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.2% by weight of TiO 2 ) and in case of 900° C. of sintering temperature.
FIG. 28 is a graph showing a relation between the addition amount (α) of V 2 O 5 and Qu in the ceramic composition and the sintering temperature in FIG. 27.
FIG. 29 is a graph showing a relation between the addition amount (α) of V 2 O 5 and τf in the ceramic composition and the sintering temperature in FIG. 27.
FIG. 30 is a graph showing a relation between the addition amount (α) of V 2 O 5 and the sintering density in the ceramic composition and the sintering temperature in FIG. 27.
FIG. 31 is a graph showing a relation between x and εr in (the main ingredient represented by Bi(Nbx Ta1-x)O 4 +0.4% by weight of V 2 O 5 +0.2% by weight of TiO 2 ) and in case of 900° C. of sintering temperature.
FIG. 32 is a graph showing a relation between x and Qu in the ceramic composition and the sintering temperature in FIG. 31.
FIG. 33 is a graph showing a relation between x and τf in the ceramic composition and the sintering-temperature in FIG. 31.
FIG. 34 is a graph showing a relation between x and the sintering density in the ceramic composition and the sintering temperature in FIG. 31.
FIG. 35 is a graph showing a relation between the sintering temperature and εr in (the main ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.4% by weight of V 2 O 5 +0.2% by weight of TiO 2 ).
FIG. 36 is a graph showing a relation between the sintering temperature and Qu in the ceramic composition in FIG. 35.
FIG. 37 is a graph showing a relation between the sintering temperature and τf in the ceramic composition in FIG. 35.
FIG. 38 is a graph showing a relation between the sintering temperature and the sintering density in the ceramic composition in FIG. 35.
FIG. 39 is a graph showing a relation between the addition amount (α) of V 2 O 5 and εr in (the main ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.2% by weight of MnO 2 +0.2% by weight of TiO 2 (or PbO)) and in case of 900° C. of sintering temperature.
FIG. 40 is a graph showing a relation between the addition amount (α) of V 2 O 5 and Qu in the ceramic composition and the sintering temperature in FIG. 39.
FIG. 41 is a graph showing a relation between the addition amount (α) of V 2 O 5 and τf in the ceramic composition and the sintering temperature in FIG. 39.
FIG. 42 is a graph showing a relation between the addition amount (α) of V 2 O 5 and the sintering density in the ceramic composition and the sintering temperature in FIG. 39.
FIG. 43 is a graph showing a relation between the addition amount (β) of MnO 2 and εr in (the main ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.4% by weight of V 2 O 5 +0.2% by weight of TiO 2 (or PbO)) and in case of 900° C. of sintering temperature.
FIG. 44 is a graph showing a relation between the addition amount (β) of MnO 2 and Qu in the ceramic composition and the sintering temperature in FIG. 43.
FIG. 45 is a graph showing a relation between the addition amount (β) of MnO 2 and τf in the ceramic composition and the sintering temperature in FIG. 43.
FIG. 46 is a graph showing a relation between the addition amount (β) of MnO 2 and the sintering density in the ceramic composition and the sintering temperature in FIG. 43.
FIG. 47 is a graph showing a relation between the addition amount (γ) of TiO 2 and εr in (the main ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.4% by weight of V 2 O 5 +0.2% by weight of MnO 2 ) and in case of 900 ° C. of sintering temperature.
FIG. 48 is a graph showing a relation between the addition amount (γ) of TiO 2 and Qu in the ceramic composition and the sintering temperature in FIG. 47.
FIG. 49 is a graph showing a relation between the addition amount (γ) of TiO 2 and τf in the ceramic composition and the sintering temperature in FIG. 47.
FIG. 50 is a graph showing a relation between the addition amount (γ) of TiO 2 and the sintering density in the ceramic composition and the sintering temperature in FIG. 47.
FIG. 51 is a graph showing a relation between the addition amount (δ) of PbO and εr in (the main ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.4% by weight of V 2 O 5 +0.2% by weight of MnO 2 ) and in case of 900 ° C. of sintering temperature.
FIG. 52 is a graph showing a relation between the addition amount (δ) of PhO and Qu in the ceramic composition and the sintering temperature in FIG. 51.
FIG. 53 is a graph showing a relation between the addition amount (δ) of PbO and τf in the ceramic composition and the sintering temperature in FIG. 51.
FIG. 54 is a graph showing a relation between the addition amount (δ) of PbO and the sintering density in the ceramic composition and the sintering temperature in FIG. 51.
FIG. 55 is a graph showing a relation between x and εr in (the main ingredient represented by Bi(Nbx Ta1-x)O 4 +0.4% by weight of V 2 O 5 +0.2% by weight of MnO 2 +0.2% by weight of TiO 2 (or PhO)) and in case of 900° C. of sintering temperature.
FIG. 56 is a graph showing a relation between x and Qu in the ceramic composition and the sintering temperature in FIG. 55.
FIG. 57 is a graph showing a relation between x and τf in the ceramic composition and the sintering temperature in FIG. 55.
FIG. 58 is a graph showing a relation between x and the sintering density in the ceramic composition and the sintering temperature in FIG. 55.
FIG. 59 is a graph showing a relation between the sintering temperature and εr in (the main ingredient represented by Bi(Nb 0 .8 Ta 0 .2)O 4 +0.4% by weight of V 2 O 5 +0.2% by weight of MnO 2 +0.2% by weight of TiO 2 (or PbO)).
FIG. 60 is a graph showing a relation between the sintering temperature and Qu in the ceramic composition in FIG. 59.
FIG. 61 is a graph showing a relation between the sintering temperature and τf in the ceramic composition in FIG. 59.
FIG. 62 is a graph showing a relation between the sintering temperature and the sintering density in the ceramic composition in FIG. 59.
DETAILED DESCRIPTION OF THE INVENTION
EXAMPLES
The present invention will be explained more specifically by way of examples.
Example 1
Bi 2 O 3 a powder (purity: 98.9%), Nb 2 O 5 powder (purity: 99.9%), Ta 2 O 5 powder (purity: 99.9%) and V 2 O 5 powder (purity: 99.5%) were used as the raw material, and they are weighed and mixed each by a predetermined amount (about 600 g as the entire amount in each of the cases) so as to provide compositions in which x ranges from 0.43 to 0.57 and each of y and the addition amount of V 2 O 5 (α% by weight) varies within a range of 0 to 1.0 in xBi 2 O 3 -(1-x) (yNb 2 O 5 -(1-y)Ta 2 O 5 ) as shown in Tables 1 and 2.
Subsequently, the weighed and mixed raw material powders were applied with primary pulverization by a vibration mill (3 hours) and then calcined in an ambient atmosphere at 700° C. for 2 hours. Then, an appropriate amount of an organic binder (15 g) and water (320 g) were added to each calcined powder and applied with secondary pulverization was conducted in a ball mill using alumina balls of 20 mmφ, at 90 rpm for 23 hours. Subsequently, they were pelletized by vacuum freeze drying (pressure: about 0.4 Torr, freezing temperature: -20° to -40° C., drying temperature: 40° to 50° C., drying time: about 20 hours). The thus pelletized raw materials were molded at a pressure of 1 ton/cm 2 to obtain cylindrical molding products each of 19 mmφ×10 mmt (height).
TABLE 1______________________________________[0.5Bi.sub.2 O.sub.3 - 0.5 {yNb.sub.2 O.sub.5 - (1 - y) Ta.sub.2 O.sub.5} +αV.sub.2 O.sub.5] ceramic composition Rel. α dielect. (V.sub.2 O.sub.5) f.sub.o const. τ.sub.fNo. y (wt %) (GHz) ε.sub.r Qu (ppm/°C.)______________________________________1 0.2 0.2 4.4 33.2 703 -56.82 0.4 0.2 4.0 42.5 510 -49.03 0.6 0.2 3.9 43.5 443 -41.24 0.8 0.2 3.9 43.1 491 -28.05 0.2 0.4 3.9 44.7 1344 -53.16 0.4 0.4 3.9 45.9 1488 -46.47 0.6 0.4 3.8 46.2 1305 -32.88 0.8 0.4 3.9 44.6 1487 -18.59 0.2 0.6 3.8 47.1 1014 -52.110 0.4 0.6 3.8 47.7 897 -39.811 0.6 0.6 3.8 46.6 791 -29.612 0.8 0.6 3.9 45.6 816 -18.513 0.2 0.8 3.7 49.0 746 -51.114 0.4 0.8 3.7 49.0 590 -36.215 0.6 0.8 3.8 48.0 505 -25.016 0.8 0.8 3.9 45.7 598 -18.9______________________________________
TABLE 2______________________________________[xBi.sub.2 O.sub.3 - (1 - x) {yNb.sub.2 O.sub.5 - (1 - y)Ta.sub.2 O.sub.5 } + αV.sub.2 O.sub.5] ceramic composition Rel. α dielect. (V.sub.2 O.sub.5) f.sub.o const. τ.sub.fNo. x y (wt %) (GHz) ε.sub.r Qu (ppm/°C.)______________________________________17 0.43 0.8 0.4 4.0 41.6 243 -26.518 0.45 0.8 0.4 4.0 42.2 610 -18.019 0.47 0.8 0.4 4.0 42.9 1100 -16.220 0.49 0.8 0.4 3.9 44.0 1360 -17.321 0.51 0.8 0.4 3.9 45.0 1432 -23.122 0.53 0.8 0.4 3.9 44.8 1190 -27.023 0.55 0.8 0.4 4.0 43.9 780 -31.524 0.57 0.8 0.4 4.0 42.7 370 -38.025 0.5 0 0.2 4.6 30.8 829 -57.526 0.5 0 0.4 4.1 40.4 1115 -48.327 0.5 0 1.0 3.7 50.3 562 -36.528 0.5 1.0 0.2 4.1 42.3 476 -23.629 0.5 0.9 0.4 4.0 43.7 1450 -11.530 0.5 1.0 0.4 4.0 42.9 1504 -2.731 0.5 1.0 1.0 4.0 44.5 557 -6.232 0.5 0.4 0 4.9 29.8 203 -68.0______________________________________
Then, the molding products were degreased in an atmospheric air at 500° C. for 3 hours and then sintered at 850° to 900° C. for 2 hours to obtain sintering products. Finally, each of the sintering products was polished at both end faces into a cylindrical shape of about 16 mmφ×8 mmt (height), further cleaned with a diluted solution comprising 5 parts of an aqueous detergent ("Eriese K-2000" manufactured by Asahi Kasei Co.) and 100 parts of water mixed together, at 23° C. for 60 min, and dried at 80° C. for 10 hours to form dielectric specimens (Nos. 1-32 in Tables 1 and 2). The temperature elevation rate was 200° C./h and the temperature lowering rate was -200° C./h in the calcining step, the temperature elevation rate was 50° C./h in the decreasing step, and the temperature elevation rate was 100° C./h and the temperature lowering rate was -100° C./h in the sintering step.
Then, εr, Qu and τf were measured for each of the specimens by a parallel conductor plate dielectric columnar resonator method (TE 011 MODE) or the like. The resonance frequency upon measurement is as shown in Table 1 (f 0 ). Further, τf was measured at a temperature region from 23° to 80° C. and calculated according τf=(f 80 -f 23 )/(f 23 ×ΔT) and ΔT=80-23=57° C. The results are shown in Tables 1 and 2 and in the graphs of FIGS. 1 to 6.
From the results, Qu decreases remarkably at x for 0.43 and 0.57 and εr also decreases considerably at x for 0.43 (No. 17 in Table 2) and τf also decreases in the negative direction at x for 0.57 (No. 24 in Table 2). On the other hand it can seen that within a range of x from 0.45 to 0.55, particularly, from 0.47 to 0.51, compositions excellent in all of εr, Qu and τf and well balanced in the characteristics is obtained (FIGS. 1-3).
Further, εr slightly decrease at y=1.0 and at a of 0.2% by weight (No. 28 in Table 2) and 0.4% by weight (No. 30 in Table 2) as compared with a case of y at 0.2 to 0.8. And if y is 0.9 and α is 0.4% by weight (No. 29 in Table 2), balance of εr, Qu and τf is excellent. If y is 0, εr decreases further. Further, if y is 0, and α is 1.0 % by weight (No. 27 in Table 2), although εr is excellent, Qu tends to decrease. Further, if y is 1.0, and αis 1.0% by weight (No. 31 in Table 2), although τf is excellent, Qu decreases. If y is 0.4 and α is 0 (No. 32 in Table 2), all εr, Qu and τf greatly decrease because sintering is insufficient (FIGS. 4-6).
In each of the examples described above, although each of the performances εr, Qu and τf is excellent individually, balance between each of them is somewhat poor.
On the other hand, if y is in a range of 0.2 to 0.8 and α is 0.8 % by weight (Nos. 13-16 in Table 1) and 0.6 by weight (Nos 9-12 in Table 1), εr is excellent. Although Qu decreases if α is 0.8% by weight but it is within a range causing no practical problem. Further, τf also exhibits a practically sufficient performance with no problem. Further, if y is within a range from 0.2 to 0.8 and α is 0.4 % by weight (Nos. 5 to 8 in Table 1), although εr tends to decrease slightly as compared with the case of α at 0.8 % and 0.6% by weight, Qu is improved greatly and τf is equivalent, to show well balanced excellent performance. Furthermore, if y is within a range from 0.2 to 0.8 and a is 0.2% by weight (Nos. 1-4 in Table 1), each of the characteristics tends to decrease as compared with the case of greater α, but they are within a practically sufficient range (FIGS. 4 to 6).
In particular, as shown in results of tables 1 and 2, it is preferred that x is from 0.47 to 0.53, y is from 0.4 to 0.8 and α is from 0.4 to 0.6, since each physical property is balanced. In this case, εr may be from 42.9 to 47.7, Qu may be from 790 to 1490 and τf may be from -46.4 to -16.2 ppm/°C.
Further, it can be seen from FIGS. 4 to 6, that each of the characteristics exhibits a substantially identical trend as y increases from 0.2 to 0.8 irrespective of the value α and, particularly, the performance τf tends to be improved, and the value rf can be controlled within a practical value while maintaining high εr and Qu with no practical problem, by varying the ratio of Nb 2 O 5 and Ta 2 O 5 .
Example 2
As the raw material in this example, PbO powder (purity: 99.5%) was added further to each of the powder used in Example 1. Then, the starting materials were weighed and mixed in the same manner as in Example 1 so as to obtain a composition in which x is 0.6, the addition amount of V 2 O 5 is 0.4% by weight and the addition amount of PbO (δ% by weight) varies within a range from 0 to 2.0 in Bi(NbxTa1-x)O 4 as shown in Table 3.
In Table 3, x is 0.2 in No. 13, an addition amount of V 2 O 5 is 3.0% by weight in No. 14, and x is 0.2 and an addition amount of V 2 O 5 is 3.0% by weight in No. 15.
Further, in the same manner as in Example 1, dielectric specimens of identical shape (Nos. 1 to 30 in Table 3) were obtained and performance evaluation (εr, Qu, τf and sintering density) was carried out. The results are also shown in Table 3 and shown in the graphs of FIGS. 7 to 14. The sintering products were cleaned after polishing at 80° C. for 30 min and then dried subsequently at 100° C. for 4 hours. The resonance frequency upon measurement is as shown in Table 3 (f 0 ). τf was measured within a temperature region of 25° to 80° C. and calculated according to τf=(f 80 -f 25 )/(f 25 ×ΔT), and ΔT=80-25=55° C.
TABLE 3__________________________________________________________________________ Sinter. V.sub.2 O.sub.5 PbO Sint. temp. (α) (δ) f.sub.o τ.sub.f densityNo. (°C.) x (wt %) (wt %) (GHz) ε.sub.r Qu (ppm/°C.) (g/cm.sup.3)__________________________________________________________________________1 850 0.6 0.4 0 Resonance wave form is 6.81 very weak.2 0.6 0.4 0.2 3.98 42.05 1425 -42.10 7.493 0.6 0.4 0.4 3.83 46.19 1041 -47.22 7.864 0.6 0.4 1 3.83 46.08 487 -58.78 7.705 0.6 0.4 2 3.75 48.06 193 -60.38 7.726 875 0.6 0.4 0 3.85 44.08 1607 -35.91 7.707 0.6 0.4 0.2 3.85 45.43 1640 -39.18 7.798 0.6 0.4 0.4 3.82 46.53 1213 -47.32 7.899 0.6 0.4 1 3.75 48.33 482 -53.06 7.9110 0.6 0.4 2 3.67 50.38 238 -73.80 7.9111 900 0.6 0.4 0 3.85 46.19 1304 -32.82 7.9012 0.6 0.4 0.2 3.83 46.21 1528 -36.67 7.8513 0.2 0.4 0.2 3.85 45.01 1511 -48.21 8.0514 0.6 3.0 0.2 3.80 46.71 735 -42.33 7.9515 0.2 3.0 0.2 3.83 46.40 594 -53.03 8.2316 0.6 0.4 0.4 3.83 46.94 1211 -43.50 7.8917 0.6 0.4 0.6 3.81 47.46 956 -47.80 7.9018 0.6 0.4 0.7 3.80 47.71 828 -49.90 7.9119 0.6 0.4 1 3.76 48.48 445 -56.27 7.9320 0.6 0.4 2 3.65 51.37 280 -83.01 7.9621 925 0.6 0.4 0 3.84 45.93 1255 -31.78 7.6722 0.6 0.4 0.2 3.82 46.36 1423 -39.76 7.8823 0.6 0.4 0.4 3.82 46.58 1192 -45.64 7.8724 0.6 0.4 1 3.75 48.52 458 -56.87 7.9225 0.6 0.4 2 3.64 51.45 240 -104.80 7.9826 950 0.6 0.4 0 3.87 44.87 1214 -33.01 7.6527 0.6 0.4 0.2 3.81 46.16 1378 -39.12 7.8428 0.6 0.4 0.4 3.82 46.46 1094 -44.83 7.8529 0.6 0.4 1 3.75 48.53 407 - 62.61 7.9130 0.6 0.4 2 3.63 51.69 214 106.00 7.97__________________________________________________________________________
From the results, εr is improved from about 45 to about 51 along with increase in the addition amount of PbO irrespective of the sintering temperature except for a case of 42.05 at a sintering temperature of 850° C. and the addition amount of PbO of 0.2% by weight (FIGS. 7 and 11). Improvement of Qu is observed if PbO is added by 0.2% by weight at each of sintering temperature as compared with the case of no addition, but it tends to decrease as the addition amount increases and, particularly, Qu decreases greatly at the addition amount of 1 to 2% by weight (the trend is shown clearly in FIGS. 8 and 12). Further, τf tends to increase toward the negative direction along with increase in the addition amount of PbO and the trend is particularly remarkable at the addition amount of 2% by weight (the trend is shown clearly in FIGS. 9 and 13).
From abovementioned results, it is preferred that x is from 0.2 to 0.9 (tables 1 and 2), the addition amount of V 2 O 5 is from 0.2 to 2.0 part by weight and the addition amount of PbO is from 0.2 to 0.6% by weight (table 3). In this case, εr may be from 45 to 48, Qu may be from 960 to 1640 (at from 3.6 to 4.0 GHz) and τf may be from -47 to -32 ppm/°C.
On the other hand, the sintering density takes a particularly small value in a case where PhO is not added and the sintering temperature is as low as 850° C. In other cases, it slightly increases at each of the sintering temperatures along with the increase in the addition amount of PbO except for a certain case but no remarkable change is observed as a whole (it can be seen also in FIGS. 10 and 14)
As described above, while each of the characteristics varies in accordance with the addition amount of PbO and the sintering temperature, each of the characteristics is within a range of causing no practical problem so long as they are within the range of the present invention. As a whole, it can he seen that most practically preferred dielectric ceramic compositions are obtained at a sintering temperature of 875° C. or 900° C., with the addition amount of PbO of 0.2 or 0.4% by weight since each of the characteristic is balanced most satisfactorily.
Further, as can be seen from the results of Nos. 13 to 15, τf tends to increase toward the negative direction if x is as small as 0.2 in the present invention, but dielectric ceramic compositions of excellent characteristics can be obtained according to the present invention within a wide range for x and the addition amount of V 2 O 5 .
Example 3
For the raw material in this example, MnO 2 powder (purity: 96.0%) was used instead of the PbO powder used in Example 2. Then, the raw materials were weighed and mixed in the same manner as in Example 2 so as to obtain compositions in which x Bi(NbxTa 1 -x)O 4 is 0.8, the addition amount of V 2 O 5 is 0.4% by weight and the addition amount of MnO 2 (β% by weight) ranges range from 0 to 2.0.
In Table x is 0.2 in 4, No. 14, addition amount of V 2 O 5 is 3.0% by weight in No. 15, and x is 0.2 and addition amount of V 2 O 5 is 0.3% by weight in No. 16 in Table 4.
TABLE 4__________________________________________________________________________ Sinter. V.sub.2 O.sub.5 MnO.sub.2 Sint. temp. (α) (β) f.sub.o τ.sub.f densityNo. (°C.) x (wt %) (wt %) (GHz) ε.sub.r Qu (ppm/°C.) (g/cm.sup.3)__________________________________________________________________________1 850 0.8 0.4 0 Resonance wave form is 7.08 very weak.2 0.8 0.4 0.2 3.84 45.85 1640 -11.61 7.523 0.8 0.4 0.4 3.81 46.83 1176 -9.76 7.524 0.8 0.4 1 3.75 48.62 715 -7.84 7.515 0.8 0.4 2 3.66 50.99 433 -5.50 7.486 875 0.8 0.4 0 3.86 44.45 1757 -18.73 7.477 0.8 0.4 0.2 3.84 46.01 1684 -11.75 7.528 0.8 0.4 0.4 3.82 46.93 1223 -9.91 7.539 0.8 0.4 1 3.75 48.71 729 -10.09 7.5110 0.8 0.4 2 3.65 51.25 449 -8.31 7.4811 900 0.8 0.4 0 3.92 44.60 1485 -18.47 7.4812 0.8 0.4 0.1 3.89 45.17 1574 -14.32 7.4913 0.8 0.4 0.2 3.86 45.74 1662 -10.16 7.5014 0.2 0.4 0.2 3.88 44.72 1482 -53.10 8.1315 0.8 3.0 0.2 3.82 46.31 681 -12.13 7.5516 0.2 3.0 0.2 3.86 45.81 721 -62.31 8.2417 0.8 0.4 0.4 3.83 46.85 1202 -8.34 7.5118 0.8 0.4 0.6 3.80 47.40 1046 -7.81 7.5019 0.8 0.4 0.7 3.79 47.68 968 -7.55 7.5020 0.8 0.4 1 3.75 48.50 734 -6.76 7.4921 0.8 0.4 2 3.65 51.45 476 -8.53 7.4722 925 0.8 0.4 0 3.91 44.78 1319 -19.47 7.3723 0.8 0.4 0.2 3.88 45.12 1680 -11.70 7.4624 0.8 0.4 0.4 3.84 46.37 1163 -8.43 7.4625 0.8 0.4 1 3.77 48.18 721 -9.38 7.4426 0.8 0.4 2 3.65 51.02 445 -10.60 7.4427 950 0.8 0.4 0 3.94 43.75 1245 -19.76 7.2528 0.8 0.4 0.2 3.91 44.09 1668 -13.33 7.3929 0.8 0.4 0.4 3.87 45.35 1181 -10.37 7.3930 0.8 0.4 1 3.80 46.95 710 -9.26 7.3531 0.8 0.4 2 3.67 50.50 418 -12.50 7.35__________________________________________________________________________
Further, in the same manner as in Example 2, dielectric specimens of identical shape (Nos. 1 to 31 in Table 4) were obtained and performance evaluation (εr, Qu, τf and sintering density) was carried out. The resonance frequency upon measurement was as shown in Table 5 (f 0 ). The results are shown together in Table 4 and a 1 so shown in the graphs of FIGS. 15 to 22.
According to the results, τf is extremely poor in a case of not adding MnO 2 and it is improved greatly by the addition of MnO 2 by 0.2% by weight. However, although τf tends to the improve a slightly with further increase of the addition amount but shows no great change (in FIG. 17, a curve at β=0 is much different from others, and other curves show no so great difference. This can be seen clearly also in FIG. 21). Further, εr is improved from about 45 to about 51 along with increase in the addition amount of MnO 2 irrespective of the sintering temperature (FIGS. 15 and 19). Further, although Qu tends to decrease along with increase in the addition amount of MnO 2 in a lower sintering temperature, it reaches a peak at the addition amount of 0.2% by weight as the sintering temperature goes higher and subsequently decreases along with increase the addition amount of MnO 2 (in FIG. 16, curves for β and β=0.2 intersect with each other between 875° C. and 900° C. and Qu at β=0.2 is higher in a high temperature region higher than 900° C. Further, such a trend is also shown in FIG. 20 for the sintering temperature at 900° C.).
From abovementioned results, it is preferred that x is from 0.2 to 0.9 (table 1 and 2), the addition amount of V 2 O 5 is from 0.2 to 2.0 part by weight (table 4) and the addition amount of MnO 2 is from 0.1 to 0.6 wt % (table 4). In this case, εr may be from 45 to 47, Qu may be from 970 to 1640 (at from 3.6 to 3.9 GHz) and τf may be from -14 to -5.5 ppm/°C.
On the other hand, the sintering density takes a particularly small value if MnO 2 is not added and the sintering temperature is as low as 850° C. In other cases where the sintering temperature is high, the sintering density is improve slightly by the addition amount of MnO 2 of 0.2% by weight at a higher sintering temperature and no remarkable changes is observed with addition amount of MnO 2 . Further, the sintering density tends to lower as a whole, as the sintering temperature goes higher (this is shown clearly in FIGS. 18 and 22).
In this way, each of the characteristics changes variously along with the addition amount of MnO 2 and the sintering temperature, but each of the characteristics lies within a range of causing no practical problem so long as they are within a range of the present invention. It can be seen as a whole, that preferred dielectric ceramic compositions well balanced in each of the characteristics can be obtained, particularly, at a sintering temperature of 875° C. or 900° C. and with the addition amount of MnO 2 of 0.2 or 0.4 by weight.
Further, as can be seen from the results of Nos. 14 to 16, τf tends to increase toward the negative direction if x is as small as 0.2 in the present invention, but dielectric ceramic compositions having practically sufficient characteristics can be obtained in a wide range for x and the addition amount of V 2 O 5 .
Example 4
For the raw material in this example, TiO 2 powder (purity: 99.9%) was used instead of the PbO powder used in Example 2. Then, the starting materials were weighed and mixed in the same manner as in Example 2 so as to obtain a composition in which x in Bi(NbxTa1-x)O4 ranges from 0 to 1.0, the addition amount of V 2 O 5 (α% by weight) ranges from 0 to 3.0 and the addition amount of TiO 2 (τ% by weight) ranges from 0 to 2.0.
Further, dielectric specimens of identical shape were prepared in same manner as Example 2 (Nos. 1 to 23 in Table 5) and performance evaluation (εr, Qu, τf and sintering density) was carried out. The resonance frequency upon measurement was as shown in Table 5 (f 0 ). The results are shown together in Table 5 and also shown in the graphs of FIGS. 23 to 38.
TABLE 5__________________________________________________________________________ Sinter. V.sub.2 O.sub.5 TiO.sub.2 Sint. temp. (α) (γ) f.sub.o τ.sub.f densityNo. (°C.) x (wt %) (wt %) (GHz) ε.sub.r Qu (ppm/°C.) (g/cm.sup.3)__________________________________________________________________________1 900 0.8 0.4 0 3.92 44.60 1485 -18.47 7.482 900 0.8 0.4 0.1 3.40 45.92 1155 -15.81 7.493 900 0.8 0.4 0.2 3.45 47.06 865 -12.24 7.514 900 0.8 0.4 0.4 3.38 47.48 678 -8.96 7.435 900 0.8 0.4 0.6 3.47 46.33 598 -2.38 7.236 900 0.8 0.4 1.0 3.52 43.37 371 10.61 6.897 900 0.8 0.4 2.0 3.54 37.39 251 53.78 6.898 850 0.8 0.4 0.2 Sintering is insufficient.9 875 0.8 0.4 0.2 3.89 45.43 909 -12.27 7.3610 925 0.8 0.4 0.2 3.40 47.16 838 -10.81 7.5211 950 0.8 0.4 0.2 3.53 47.70 785 -11.76 7.5212 900 0.8 0 0.2 Sintering is insufficient.13 900 0.8 0.2 0.2 3.47 46.73 839 -13.55 7.5014 900 0.8 1.0 0.2 3.35 47.62 613 -5.51 7.5515 900 0.8 2.0 0.2 3.48 48.18 318 -13.94 7.5316 900 0.8 3.0 0.2 3.60 49.01 185 -21.63 7.5417 900 0 0.4 0.2 3.59 42.03 553 -52.13 8.0818 900 0.2 0.4 0.2 3.53 44.54 512 -55.21 8.1119 900 0.4 0.4 0.2 3.48 46.44 631 -48.03 8.0520 900 0.6 0.4 0.2 3.41 47.21 725 -30.12 7.9021 900 0.7 0.4 0.2 3.43 47.13 795 -21.18 7.7022 900 0.96 0.4 0.2 3.45 46.11 1010 -0.11 7.1523 900 1.0 0.4 0.2 3.23 45.86 1050 2.01 7.05__________________________________________________________________________
The results show that τf improves greatly along with the addition amount of TiO 2 and τf can be controlled easily (FIG. 25). However, since εr and Qu decrease along with addition of TiO 2 (FIGS. 23 and 24), addition of a great amount of TiO 2 is not preferred.
Further, if V 2 O 5 is not added (No. 12), the sintering is insufficient and measurement for each of the characteristics is impossible. Then, since εr increases (FIG. 27) and τf decreases (FIG. 29) by the addition, τf can be controlled. However, since Qu decreases by the addition (FIG. 28), addition of a great amount of V 2 O 5 is not preferred.
Further, since τf increases along with increase for the value x in Bi(NbxTa1-x)O 4 (FIG. 33), τf can be controlled by the change of the value x. Further, since εr and Qu also increase along with this increase (FIGS. 31 and 32), although it is preferred in view of this physical property, the sintering density is lowered (FIG. 34). 7.0 kg/m 3 of sintering density can be ensured even if x is 1.0 (FIG. 34).
Further, if the sintering temperature is at 850° C. (No. 8 in Table 5), sintering is insufficient and measurement for each of the characteristics is impossible. On the other hand, at 875° to 950° C. (x=0.8, V 2 O 5 =0.4% by weight, TiO 2 =0.2% by weight), the sintering density is as large as 7.36 to 7.52 kg/m 3 (FIG. 38) and the physical properties is are also stable (FIGS. 35-37).
As described above, while each of the physical properties changes variously in accordance with the addition amounts of V 2 O 5 and TiO 2 and the sintering temperature, each of the characteristics lies within a range causing no practical problem so long as they are within a range of the present invention. For instance, in a case where x=0.6 to 0.96, V 2 O 5 =0.2 to 1.0% by weight and TiO 2 =0.1 to 0.6% by weight, τf=-30 to 0 ppm/°C., Qu=610 to 1160, εr=42 to 48. In a case where x=0.8 to 0.96, V 2 O 5 =0.4 to 1.0% by weight and TiO 2 =0.2 to 1.0% by weight, εr=43.3 to 47.7, Qu=370 to 910, τf=-13 to +11 ppm/°C. Particularly, in a case where x=0.8, V 2 O 5 is 0.4% by weight, TiO 2 =0.2 to 0.4% by weight, εr=45.4 to 47.7, Qu=510 to 910 and τf=-13 to -9 ppm/°C., showing excellent balance of performance.
As can be seen from the results of Nos. 18 to 20 in Table 5, although τf tends to increase toward the negative direction (-55 to -30 ppm/°C.) if x=as small as 0.2 to 0.6 in the present invention, εr is from 42.0 to 47.2 and Qu is from 510 to 730, which are practically sufficient characteristics.
Example 5
(1) Preparation of dielectric ceramic composition
As the raw material in this example, TiO 2 powder (purity: 99.9%) or PbO powder (purity: 99.5%) was further used in addition to the powder used in Example 3. Then, the raw materials were weighted and mixed in the same manner as in Example 3 so as to obtain a composition in which x in Bi(NbxTa1-x)O 4 varies from 0 to 1.0, the addition amount of V 2 O 5 (α% by weight) varies from 0 to 3.0, the addition amount of MnO 2 (β% by weight) varies from 0 to 2.0 and the addition amount of TiO 2 (γ% by weight, shown in Table 6) varies from 0 to 2.0 and, further, the addition amount of PbO (δ% by weight, shown in Table 7) varies from 0 to 2.0, as shown in Table 6 and 7.
Further, in the same manner as in Example 3, dielectric specimens of identical shape (Nos. 1 to 27 in Table 6 and Nos. 1 to 29 in Table 7) were obtained and performance evaluation (εr, Qu, τf and sintering density) was carried out. The resonance frequency upon measurement was as shown in Tables 6 and 7 (f 0 ). The results are shown together in Tables 6 and 7 and also shown in the graphs of FIGS. 39 to 62.
(2) Effect of examples in V 2 O 5 --MnO 2 --TiO 2 system composition
According to the results of Table 6 and FIGS. 39-50 and FIGS. 55 to 62, if V 2 O 5 is not added (No. 12 in Table 6) sintering is insufficient and measurement for each of the characteristics is impossible. Then, since εr increases (FIG. 39) and τf decreases (FIGS. 41) along with addition, τf can be controlled. However, since Qu decreases along with addition (FIG. 40), addition of a great amount of V 2 O 5 is not preferred.
TABLE 6__________________________________________________________________________ Sinter. α β γ Sint. temp. (V.sub.2 O.sub.5) (MnO.sub.2) (TiO.sub.2) f.sub.o τ.sub.f densityNo. (°C.) x (wt %) (wt %) (wt %) (GHz) ε.sub.r Qu (ppm/°C.) (g/cm.sup.3)__________________________________________________________________________1 900 0.8 0.4 0.2 0 3.86 45.74 1662 -10.16 7.502 900 0.8 0.4 0.2 0.1 3.40 46.40 1493 -8.81 7.513 900 0.8 0.4 0.2 0.2 3.35 47.06 1325 -7.46 7.534 900 0.8 0.4 0.2 0.4 3.38 48.57 747 -1.17 7.505 900 0.8 0.4 0.2 0.7 3.36 48.91 632 6.48 7.366 900 0.8 0.4 0.2 1.0 3.24 49.25 517 14.13 7.227 900 0.8 0.4 0.2 2.0 3.42 46.81 255 50.22 6.678 850 0.8 0.4 0.2 0.2 3.15 46.33 1618 -6.59 7.309 875 0.8 0.4 0.2 0.2 3.19 46.92 1461 -6.78 7.5210 925 0.8 0.4 0.2 0.2 3.33 46.94 1319 -6.30 7.5211 950 0.8 0.4 0.2 0.2 3.31 47.20 1282 -5.44 7.5112 900 0.8 0 0.2 0.2 Sintering is insufficient.13 900 0.8 0.2 0.2 0.2 3.41 46.63 1227 -10.91 7.5014 900 0.8 1.0 0.2 0.2 3.35 47.88 893 -2.45 7.5615 900 0.8 2.0 0.2 0.2 3.43 48.91 598 -9.03 7.5016 900 0.8 3.0 0.2 0.2 3.41 49.04 417 -16.79 7.4517 900 0.8 0.4 0 0.2 3.45 47.06 865 -12.24 7.5118 900 0.8 0.4 0.4 0.2 3.31 47.23 1438 -6.03 7.5019 900 0.8 0.4 1.0 0.2 3.44 47.46 903 -11.10 7.5020 900 0.8 0.4 1.5 0.2 3.41 47.18 760 -11.46 7.4621 900 0.8 0.4 2.0 0.2 3.40 46.89 618 -11.83 7.4122 900 0 0.4 0.2 0.2 3.31 44.18 884 -48.23 8.0823 900 0.2 0.4 0.2 0.2 3.24 45.90 1023 -49.58 8.1324 900 0.4 0.4 0.2 0.2 3.43 47.16 1211 -44.35 7.9825 900 0.6 0.4 0.2 0.2 3.41 47.51 1203 -25.11 7.7326 900 0.96 0.4 0.2 0.2 3.27 46.02 1389 3.51 7.2127 900 1.0 0.4 0.2 0.2 3.40 45.74 1415 6.34 7.05__________________________________________________________________________
TABLE 7__________________________________________________________________________ Sinter. α β δ Sint. temp. (V.sub.2 O.sub.5) (MnO.sub.2) (PbO) f.sub.o τ.sub.f densityNo. (°C.) x (wt %) (wt %) (wt %) (GHz) ε.sub.r Qu (ppm/°C.) (g/cm.sup.3)__________________________________________________________________________1 900 0.8 0 0.2 0.2 Sintering is insufficient.2 900 0.8 0.2 0.2 0.2 3.45 47.80 641 -12.90 7.573 900 0.8 0.3 0.2 0.2 3.44 47.30 1050 -9.60 7.554 900 0.8 0.4 0.2 0.2 3.47 46.81 1465 -6.28 7.535 900 0.8 0.6 0.2 0.2 3.42 46.53 1430 -1.75 7.516 900 0.8 0.8 0.2 0.2 3.47 44.88 1952 -14.46 7.467 900 0.8 1.0 0.2 0.2 3.45 43.75 1842 -23.14 7.428 900 0.8 2.0 0.2 0.2 3.46 42.49 1204 -35.03 7.359 900 0.8 3.0 0.2 0.2 3.40 41.80 513 -44.12 7.4010 850 0.8 0.4 0.2 0.2 3.50 46.98 1523 -16.24 7.4811 875 0.8 0.4 0.2 0.2 3.39 47.13 1468 -11.74 7.5512 925 0.8 0.4 0.2 0.2 3.48 46.89 1388 -13.43 7.5013 950 0.8 0.4 0.2 0.2 3.45 47.04 1399 -10.02 7.5214 900 0.8 0.4 0 0.2 3.40 45.35 1604 -18.04 7.5015 900 0.8 0.4 0.1 0.2 3.46 46.58 1520 -15.47 7.5316 900 0.8 0.4 0.4 0.2 3.35 47.86 1351 -2.07 7.5217 900 0.8 0.4 1.0 0.2 3.46 48.51 1047 -5.34 7.5018 900 0.8 0.4 2.0 0.2 3.45 49.10 798 -12.95 7.5319 900 0.8 0.4 0.2 0 3.86 45.74 1662 -10.16 7.5020 900 0.8 0.4 0.2 0.4 3.65 47.39 1293 -13.24 7.4921 900 0.8 0.4 0.2 0.5 3.36 47.42 1203 -15.70 7.4922 900 0.8 0.4 0.2 1.0 3.54 48.48 753 -28.00 7.4823 900 0.8 0.4 0.2 2.0 3.32 49.25 490 -49.57 7.4524 900 0 0.4 0.2 0.2 3.45 43.81 1050 -44.03 8.0725 900 0.2 0.4 0.2 0.2 3.41 45.99 1223 -48.15 8.0926 900 0.4 0.4 0.2 0.2 3.40 46.75 1335 -39.95 8.0027 900 0.6 0.4 0.2 0.2 3.47 47.01 1421 -23.42 7.7528 900 0.96 0.4 0.2 0.2 3.40 45.89 1503 3.98 7.1229 900 1.0 0.4 0.2 0.2 3.49 45.50 1530 5.15 7.04__________________________________________________________________________
Further, since Qu increases along with addition of MnO 2 up to 0.4% by weight, the addition is effective, but addition of a great amount (1 and 2% by weight) is not preferred because Qu decreases greatly (FIG. 43).
It is shown that τf is improved greatly by addition of TiO 2 and τf can be controlled easily (FIG. 49)
Further, addition of TiO 2 up to 1.0% by weight is preferred since εr increases (FIG. 47). Further, since Qu decreases by the addition of TiO 2 and, particularly, Qu decreases remarkably as 747 at 0.4% by weight, addition of a great amount of TiO 2 is not preferred (FIG. 48).
Further, since τf increases along with increase of the value x in Bi(NbxTa1-x)O 4 (FIG. 57), τf can be controlled by the change of the x. Further, since Qu increases along with increase of x (FIG. 56) and εr also increases with x up to 0.6 (FIG. 55), it is preferred in view of this physical property, but the sintering density is lowered (FIG. 58). Further, 7.05 kg/m 3 of the sintering density can be insured even if x is 1.0 (No. 27, FIG. 58).
Further, sintering is sufficient even at a sintering temperature of 850° C. (No. 8 in Table 6) and the sintering density is as great as 7.30 to 7.51 kg/m 3 at 850°-950° C. (x=0.8, V 2 O 5 =0.4% by weight, MnO 2 =0.2% by weight and TiO 2 =0.2% by weight) (Nos. 8 to 11 in Table 6, FIG. 62), and physical properties are also stable (FIGS. 59 to 62).
As described above, each of the characteristics changes variously in accordance with the kind of each of the additives, the addition amount thereof and the sintering temperature and well balanced practical performances as shown below are given, for example, with the range of the following compositions according to the results of this example (Table 6).
(1) At V 2 O 5 : 0.2 to 1.0% by weight, Mn 2 , TiO 2 : both 0.2% by weight and x: 0.8, εr: 46.6 to 47.9, Qu: 890 to 1300, τf: -10.91 to -2.45 ppm/°C.
(2) At V 2 O 5 : 0.4% by weight, MnO 2 , TiO 2 : both 0.2% by weight and x: 0.8, εr: 47.1, Qu: 1325, τf: -7.46 ppm/°C.
(3) At MnO 2 : 0.2-1.0% by weight, V 2 O 5 : 0.4% by weight, TiO 2 : 0.2% by weight and x: 0.8, εr: 47.0 to 47.5, Qu: 900 to 1440, τf: -11.1 to -6.0 ppm/°C.
(4) At TiO 2 : less than 0.4% by weight, V 2 O 5 : 0.4% by weight, MnO 2 : 0.2% by weight and x: 0.8, εr: 45.7 to 48.6, Qu: 750 to 1660, τf: -10.2 to -1.1 ppm/°C.
(5) At TiO 2 : 0.1 to 0.2% by weight, V 2 O 5 : 0.4% by weight, MnO 2 : 0.2% by weight and x: 0.8, εr: 46.4 to 47.1, Qu: 1320 to 1490, τf: -8.8 to -7.5 ppm/°C.
(6) At V 2 O 5 : 0.2 to 1.0% by weight, MnO 2 : not more than 1.0% by weight, TiO 2 : not more than 0.4% by weight and x: 0.8 to 0.96, τf: -12 to +7 ppm/°C., Qu: 800 to 1600, and εr: 45 to 50.
(3) Effect of the example in V 2 O 5 --MnO 2 --PbO system composition
According to the results of Table 7 and FIGS. 39 to 46 and FIGS. 51 to 62, if V 2O 5 is not added (No. 1 in Table 7), sintering is insufficient and measurement for each of the characteristics is impossible. Then, since τf and Qu change by the addition (each in FIGS. 41 and 40), τf and Qu can be controlled. Particularly, since τf increases along with the addition up to 0.6% and Qu increases along with addition up to 0.8% by weight, such addition is preferred.
Further, εr increases along with addition of MnO 2 (FIG. 43). Further, τf increases along with addition up to 0.4% by weight (FIG. 45). Since Qu decreases by the addition, a great amount of addition is not preferred (FIG. 44).
Since τf changes along with addition of PbO (mainly in the negative direction), it shows that τf can be controlled easily (FIG. 53). Further, since εr increases with the addition, it is preferred (FIG. 51). Since Qu decreases with the addition, a great amount of addition is not preferred (FIG. 52).
Further, since τf changes greatly along with increase of the value x in Bi(NbxTa1-x)O 4 (mainly changes in the positive direction) (FIG. 57), τf can be controlled by the change of the value x. Further, since Qu increases along with increases of the value x, it is preferred (FIG. 56). While the sintering density tends to lower with the addition, 7.04 kg/m 3 of the sintering density can be ensured even x is 1.0 (No. 29 in Table 7, FIG. 54).
Further, referring to the sintering temperature, sufficient sintering is attained at 850° to 950° C. (FIG. 62) and physical properties are also stable (FIGS. 59-62). Like that in the V 2 O 5 --MnO 2 --TiO 2 system composition.
As described above, while each of the characteristics changes variously in accordance with the kind of each of the additives, the addition amount thereof and the sintering temperature, the following well balanced practical performances is shown, for example, within a compositional range shown below according to the results of this example (Table 7).
For instance, the V 2 O 5 --MnO 2 --PbO system compositions exhibit the following well balanced practical performances.
(1) At V 2 O 5 : 0.4 to 0.8% by weight, MnO 2 and PbO: both 0.2% by weight and x: 0.8, εr: 44.9 to 46.8, Qu: 1460 to 1950, τf: -14.5 to -1.7 ppm/°C.
(2) At V 2 O 5 : 0.6% by weight, MnO 2 and PbO: both 0.2% by weight and x: 0.8, εr: 46.5, Ou: 1430, τf: -1.75 ppm/°C.
(3) At MnO 2 : 0.2 to 0.4% by weight, V 2 O 5 : 0.4% by weight, PbO: 0.2% by weight and x: 0.8, εr: 46.8 to 47.9, Qu: 1351 to 1465, τf: -6.3 to -2.1 ppm/°C.
(4) At PbO: 0.2 to 0.4% by weight, V 2 O 5 : 0.4% by weight, MnO 2 : 0.2% by weight and x: 0.8, εr: 46.8 to 47.4, Qu: 1293 to 1465, τf: -13.2 to -6.3 ppm/°C.
(5) At V 2 O 5 :0.3 to 0.8% by weight, MnO 2 : 0.1 to 1.0% by weight, PbO: not more than 0.4% by weight and x: 0.8 to 0.96, τf: -15 to +4 ppm/°C., Qu: 1000 to 2000 and εr: 44 to 49.
The present invention is not restricted to the concrete examples as described above but variously modified embodiment can be made within a scope of the present invention in accordance with the purpose and application uses thereof. | The present invention provides a microwave dielectric ceramic composition in which εr, Qu and τf are generally controlled within a practical characteristic range and each of the characteristics is maintained in a well balanced state. A ceramic composition of the present invention comprises a composition represented by xBi 2 O 3 -(1-x) (yNb 2 O 5 -(1-y)Ta 2 O 5 ) in which 0.45≦x≦0.55 and 0.1≦y<1.0 as a main ingredient, to which not more than 0.8 parts by weight of V 2 O 5 is added and incorporated. An another ceramic composition comprises a composition represented by Bi(NbxTa1-x)O 4 in which 0<x≦0.96 as a main ingredient, to which not more than 5 wt % of V 2 O 5 and not more than 2 wt % of PbO are added and incorporated. An another ceramic composition comprises the main ingredient as described above to which not more than 5 wt % of V 2 O 5 and not more than 2 wt % of MnO 2 are added and incorporated. An another ceramic composition comprises the main ingredient as described above to which not more than 2 wt % of V 2 O 5 and not more than 1 wt % of TiO 2 are added and incorporated. An another ceramic composition comprises the main ingredient as described above, to which not more than 2 wt % of V 2 O 5 , not more than 2 wt % of MnO 2 and not more than 0.7 wt % of TiO 2 are added and incorporated. Instead of TiO 2 described above, not more than 0.5 wt % (particularly not more than 0.4 wt %) of PbO can be added and incorporated. | 2 |
BACKGROUND OF THE INVENTION
From time to time in the past, there has been interest in reducing wastage of hydrocarbon fuels such as gasoline, primarily as an economy measure. Recently, however, there has been renewed interest in reducing such wastage, to avoid polluting the atmosphere, and more recently, because of the actual shortages of gasoline and other fuel and their rising costs, to save fuel. For these reasons, an objective, as to gasoline for example, is to restrict the emission of hydrocarbonaceous materials from the gasoline into the atmosphere.
The emission of hydrocarbons from gasoline into the atmosphere can be divided into two categories: (1) emissions from incomplete combusion in the operation of motor vehicles and (2) emissions in the handling of the gasoline before the combustion process occurs. From the following data, the relative magnitude of each category can be appreciated.
The Environmental Protection Agency gives an average figure of hydrocarbon emission from incomplete combustion of 200 pounds per 1,000 gallons of gasoline consumed in a vehicle with no control devices. U.S. federal New Car Emission Standards adopted for the 1975 model year require that emissions not exceed 0.46 grams per mile. Using the average mileage figure of 14.4 miles per gallon, this emission limit is equivalent to 14.6 pounds per 1,000 gallons. Information currently available indicated that further reductions in this category are not economically feasible.
A study of the typical pattern of gasoline storage and handling reveals five major points of hydrocarbon emission before the combustion process occurs: (a) Breathing and filling losses from storage tanks at refineries and bulk terminals; (b) Filling losses from loading tank trucks at refineries and bulk terminals; (c) Filling losses from loading underground storage tanks at service stations; (d) Spillage and filling losses in filling automobile gas tanks at service stations; and (e) Evaporation losses from the carburetor and gas tank of motor vehicles.
Breathing loss has been defined as the loss associated with the thermal expansion and contraction of the vapor space resulting from temperature cycles. Filling loss has been defined as the loss due to vapors being expelled from a tank by displacement as a result of filling.
In "splash filling," the gasoline enters the top of the fill pipe and then has a free fall to the liquid surface in the tank. The free falling tends to break up the liquid stream into droplets. As these droplets strike the liquid surface, they carry entrained air into the liquid and a kind of boiling action results as this air escapes up through the liquid surface. The net effect of these actions is the creation of additional vapors in the tank. In "submerged filling," the gasoline flows to the bottom of the tank through the fill pipe and enters below the surface of the liquid. This method of filling creates very little disturbance in the liquid bath and, consequently, less vapor formation than splash filling.
The following table is from data from the publication "Compilation of Air Pollutant Emission Factors" -999-AP-42 published by the U.S. Environmental Protection Agency.
______________________________________Hydorcarbon EmissionsPoint of emission lb/1000 gal. of throughput______________________________________Filling tank vehiclesSplash filling 8.2Submerged filling 4.950% splash filling and 50% submergedfilling 6.4Filling service station tanks Splash filling 11.5 Submerged filling 7.3 50% splash fill and 50% submerged filling 9.4Filling automobile tanks 11.6Automobile evaporation losses 92 (gas tank and carburetor)______________________________________
From the above data, it can readily be seen that emissions from filling are a significant problem.
It is also known that in the standard rigid steel automotive gasoline tank, there is a substantial amount of "sloshing" of the fuel as the vehicle moves. This results in a kind of "boiling" action similar to that described above as being experienced with "splash filling." The result is that a substantial amount of gasoline vapor is constantly being generated within the tank, and the amount of vapor so generated becomes increasingly substantial as the level in the tank drops from the completely full condition as more space becomes available. This phenomenon increases any given fuel level to a point where the atmosphere immediately above the gasoline becomes saturated. To maintain such a saturated condition, however, is made more difficult if not impossible by the practice of "venting," that is, in the past provision has been made to permit pressure differentials between the interior and the exterior of the tank to be relieved. This is necessary because the volume increases due to vaporization of the fuel from "sloshing" or temperature rises could otherwise become so substantial as to cause the tank to burst. Conversely, as "sloshing" subsides, and/or temperature drops, and/or gasoline is removed from the tank the resulting vacuum within the tank can become so substantial as to cause the tank to buckle. The usual method of coping with these considerations in the past has been to vent the tank to the atmosphere, but the result of this has been a signicant amount of "breathing," and consequent loss of the lowest boiling point constituents of the gasoline, which are valuable energy sources and are believed to be potent as chemical causes and reactants to produce objectionable environmental contamination and conditions such as the well-known California "smog."
In the past, various attempts have been made to inhibit such fuel loss and/or contamination phenomena. Some of the devices which have been suggested for coping with these problems have included floating a slab of plastic or foam rubber on the surface of the fuel, and the use of a vacuum relief valve and a pressure relief valve in the tank. In this connection reference is made to Shiobara U.S. Pat. No. 3,653,537. Such suggestions have had limited acceptance, however, due to their comparatively complex structure and limited effectiveness.
Accordingly, it is an object of the present invention to provide a means to decrease the loss of vapors from vehicular fuel storage systems to the atmosphere.
It is another object of the present invention to provide a means for decreasing the loss of vapors from vehicular fuel storage systems which is simple in structure, functionally reliable and effective, and inexpensive to produce and maintain.
SUMMARY OF INVENTION
Various beneficial objects may be achieved through practice of the present invention which, in one embodiment useful as a vehicular fuel storage apparatus, comprises the combination of a rigid outer tank, a collapsible liner positioned within the outer tank, and means for removing vapors from the top of the liner, and in another embodiment comprises the sub-combination of the vapor removing means comprising one or more conduit means for conducting said vapors from the top of the liner into the carburetion system of the associated vehicle with one or more liquid check valves positioned in the flow paths of said conduit means.
DESCRIPTION OF DRAWINGS
This invention may be more clearly understood from the description of preferred embodiments which follows, and from the attached drawing in which
FIG. 1 illustrates a preferred embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 illustrates preferred embodiment of the present invention. Illustration therein is a rigid outer tank or 10 made from steel or other strong durable material which will provide sufficient structural support, although the shape of the tank 10 is not critical, typically is described as a rectangular solid more or less and preferably, it is made in top and bottom component sections which can be bolted together or otherwise easily engaged and disengaged from each other to facilitate repair, removal, and/or replacement of the liner 20 hereinafter described. The tank 10 should have interior walls which are substantially smooth and free of burrs or other irregularities which might harm the lower 20 and, to this end, may even be coated with felt, foam-rubber, or other material which will avoid damage to the liner 20. The outer tank 10 has a filler pipe 12 leading to the bottom region of the tank 10. A filler cap 14 is positioned at the opening 28 of the filler pipe 12, and preferably is of a type which will require that some degree of pressure or vacuum will be present within the tank before any vapors are vented therefrom or air sucked into the tank as a means to further prevent pollution of the atmosphere and/or loss of fuel. An additional structural feature which may be incorporated into the filler pipe near its top is an inlet closure 16 made from relatively soft flexible material which is sufficiently chemically tolerant of gasoline and other hydrocarbons to avoid severe deterioration. As shown, it forms a constriction in the mouth of the filler pipe 12 which will closely enfold the outside of the fuel pump nozzle when filling is taking place, thereby further minimizing the discharge of fuel vapors into the atmosphere at that time. It is also possible to utilize the closure 16 to control the type of fuel which may be put into the tank. Thus, under certain regulations, it may be permissable to use leaded or non-leaded gasoline in trucks, but only non-leaded gasoline in autos. In that case, the nozzle of the gasoline pump for non-leaded gasoline could be of a smaller diameter than the nozzle for leaded gasoline, and correspondingly the inlet closure 16 for autos would be smaller than that for trucks, thus making it impossible to insert the non-leaded gasoline pump nozzle into the filler pipe of an automobile.
Positioned within the outer tank 10 is a liner 20. It conforms in outer shape and dimensions substantially with the shape and dimensions of the inside of the tank 10, and is "continuous," i.e., a liquid tight bag which is completely closed except for the filling neck 22 and a fuel feed line opening 24 and vapor return lines 40, 42, 44. It is made from supple material which will render it readily collapsible and is chemically tolerant to the materials to which it is exposed. In form, it comprises a main body portion 26 positioned within the tank 10 and a filling neck portion 22 positioned within the filler pipe 12 whereby gasoline poured into the top opening 28 of the filler pipe 12 will be caused to flow into the interior of the main body portion 26 of the liner 20 since the open end 30 of the neck portion 22 is secured in liquid-tight fashion to the interior of the filler pipe 12 by means of adhesives, an expansion ring 32, and/or other known per se sealing means.
An opening 24, preferably with a neck portion 34 is positioned at the bottom of the liner 20, juxtaposed to the vehicle fuel line 36 by which fuel may be transfered to the vehicle's engine fuel pump (not shown). Optionally, but desirably, fuel line filter in the form of a screen 38 is positioned over the opening 24 to ensure that foreign objects which may get into the liner 20 are not passed along with the fuel into the vehicle's engine.
Positioned at the top of the main portion 26 of the liner 20 and communicating with the interior thereof are one or more conduit means in the form of tubes 40, 42, 44, each of which has expansion loops 46, or convolutions (not shown) or other means by which the length of the tubes within the tank 10 may effectively be lengthened or shortened as the top of the liner 20 raises or lowers as hereinafter described, without materially interrupting the ability of the tubes to transport vapor. As illustrated, the conduit means converge in a common liquid check valve 47. It will be obvious from the discussion which follows, however, that a multiplicity of individual check valves, one each in one or more of the tubes, might also be effectively used. The purpose of each check valve, whether individual or multiple, is to permit only vapors to pass through the conduit means but no significant amounts of liquid. Their internal structure is not illustrated because the design and structure of such devices is well known per se.
An adjustable relief valve 48 is positioned on the opposite side of the liquid check valve(s) from the tubes 40, 42, 44, in communicating continuity therewith by means of an extension of the conduit means thereto in the form of tube 50. The other side of the relief valve 48 is connected to a suction producing means (not shown) such as the venturi in the vehicle carburetor, by means of a further extension of the conduit means in the form of tube 52. The purpose of the relief valve 48 is to establish a minimum amount of vacuum in the conduit means which must be exceeded before the suction means will begin to suck vapor via the conduit means from the top of the liner 20, and as such it is adjustable by mechanisms which are known per se so that the amount of such vacuum may be selected and/or regulated. By this means, the delivery of vapors into the vehicle carburetion system as hereinafter described may be selectively prohibited, as for example, when the engine is idling and duel mixture continuity is more critical. Positioned between the outside of the top of the main portion 26 of the liner 20 and the inside of the top of the tank 10 are air filled expansion volumes 54, 56 in the form of closed, air filled bladders, or foam rubber block, or other compressible and/or volume displaceable bodies whereby, as the top of the liner 20 closes in toward the inside of the tank 10 as the liner 20 is being filled, increasing resistance to further expansion of the liner 10 will be provided to prevent overfill and to relieve pressure buildup from thermal expansion of the fuel. The tank 10 also has a vent 58 in its top, whereby air may enter or leave the interior of the tank 10 as the liner 20 inflates or deflates. In use, the device as illustrated operates as follows.
When the device is installed on the vehicle, the liner 20 will be in place within the tank 10 and will be collapsed with no air or fuel in it. To fill the tank, the filler cap 14, is removed and the nozzle from the gasoline fueling station is inserted in the closed inlet 30. The pump is turned on and gasoline 62 flows down the neck portion 22 of the liner 20 positioned within filler pipe 12, through the fuel inlet 60, and into the main body portion 26 of the rigid support container 10. The liner when filled conforms to the shape of the rigid support container. When the tank is filled the nozzle automatically shuts off and is withdrawn and the filler cap 14 replaced. During this operation some air usually will have been introduced into the liner 20. Basically this is the air present at the end of the nozzle which goes into the tank with the gasoline. In addition, air dissolved in the gasoline might also be released in the liner.
Upon start-up and operation of the engine, fuel is fed from the fuel outlet 24, through the fuel pump and to the carburetor in the normal fashion.
At fairly high engine speeds the vacuum in the "throat" or venturi of the carburetor is sufficient to open the relief valve 48. When this occurs, any hydrocarbon laden air or vapor present in the main body 26 of the liner 40 is drawn through the conduit means formed by the tubes 40, 42, 44, 50, 52, the liquid check valve, 47, and the relief valve, 48, and into the carburetor throat. From there, of course, it is introduced to the intake manifold and is burned in the engine. When substantially all such vapor is removed from the main portion 26 of the liner 20, liquid fuel 60 will enter one or more of the tubes 40, 42, 44, of the conduit means until such liquid fuel comes to the liquid check valve 47. At this point the check valve 47 will close and there will be no more flow through the conduit means. As the engine is run and fuel is used, the liner 20 collapses to whatever the volume of liquid left until it is necessary to refuel again.
During the entire process described above, substantially the only time air enters the system is during the fill cycle. Since the interior of the liner 20 is maintained substantially contiguous with the outside of the body of liquid throughout, vaporization from "sloshing" or temperature changes is minimized, so that vapor generation is kept to a minimal amount and is removed through the conduit means during engine operation and is burned.
Since it is only a comparatively small amount and is quickly removed from the liner 20, there is little affect on engine operation. In addition, little or no air that has been in contact with gasoline can reach the atmosphere and therefore evaporative emissions from the fuel tank during the fill cycle and engine operation are minimized thereby reducing pollution of the air and energy losses through fuel evaporation and/or venting. Air, of course, enters the rigid container during collapse of the liner and is ejected during the fill cycle. However, this air has only been in contact with the outside of the liner and therefore contains no significant amount of hydrocarbons which cause pollution.
The expansion volumes 54, 56 come into play if the tank is filled and its contents expand as when it is allowed to stand in an area where the fuel will warm up. If this should occur the air in the expansion volumes 54, 56 compresses by the same amount the fuel expands. At less than full conditions, the liner will expand and collapse as the fuel warms up or cools in response to environmental conditions. Again, since no air is lost from the liner then, there is no evaporation loss during the breathing cycle.
The system described above is particularly suitable for use in automobiles, however, it is also applicable to other systems and processes involved with relatively low vapor pressure liquids. Examples include other types of internal combustion engines systems such as trucks, motorcycles, etc. The transfer and storage of fuel at gasoline stations, and the transfer and storage of low vapor pressure liquids in industrial applications.
EXAMPLE
A system substantially like the embodiment described above was installed in a 1972 Chevrolet van powered with a 350 cubic unit V-8 engine. Two types of tests were conducted, one in neutral at various engine speeds and a second on the road under normal operating conditions. The adjustable relief valve was connected to the carburetor throat through a tee in the vacuum advance line.
The engine functioned normally in all respects during these tests and no difficulty was encountered either in filling the liner or in feeding gasoline to the fuel pump. Air was artifically introduced into the liner to determine if the vent system worked properly and if introduction of this air into the engine would affect operation. In all cases air was drawn from the liner when the vacuum at the carburetor throat was 5 psi or above. This occured until no air was left in the liner at which point fuel entered the check valve and shut it off.
It is to be understood that the preceding discussion, and that embodiments of the present invention discussed therein and illustrated in the attached drawings and as Claimed, are by way of illustration and not of limitation, and that a wide variety of embodiments of the present invention may be practiced by those skilled in the arts without departing from the spirit or scope of this invention. | This invention, in one embodiment useful as a vehicular fuel container, includes as rigid outer tank, a collapsible inner bladder, expansion volumes positioned between said tank and said bladder, and means for causing fuel vapors to be removed from the bladder and injected into the vehicle carburation system for subsequent combustion. | 1 |
FIELD OF THE INVENTION
The present invention relates to a heel rest for an iron. More specifically, the heel rest of the present invention, comprises a recess to improve the stability of an iron in its upright position on a soft surface, such as a padded ironing board or carpet. As the iron is placed in the upright position, the weight of the iron presses down upon the soft surface and causes the soft surface located directly under the recess to rise and fill into the recess.
DISCUSSION OF THE PRIOR ART
Generally, the ironing of clothing occurs on an ironing board. The ironing board comprises a flat surface and is usually manufactured from metal or wood. As the soleplate of the iron contacts the surface of the ironing board, high temperatures result, which may cause the fabric being ironed to burn. As a result, padding is generally placed between the ironing board and the ironing board cover to function as insulation between the ironing board and iron. The padding may even be incorporated directly into the manufacture of the ironing board cover. The padding also serves an additional purpose of providing a more smooth and soft surface, to enable the iron to more freely and smoothly traverse the surface of the fabric.
Generally, when a person is adjusting the article to be ironed, the iron is left supported by the heel of the iron in an upright position. When a person is finished ironing, the iron is placed in an upright position on the ironing board, or the carpet. One reason for placing the iron in an upright position is the high temperatures that the soleplate of the iron may reach, e.g. temperatures greater than the boiling temperature of water. As a result, if the iron tips over onto the fabric being ironed, furniture or carpet may burn or discolor. In addition, a steam iron left in its vertical position may leak water from the pores of the soleplate onto an item, such as the fabric being ironed, furniture or carpet, thus, possibly staining the item. Accordingly, it is desirable to have an iron which will remain stable in its upright position.
The irons of the prior art contain rear covers or heel rests having a shape or a configuration not conducive to providing stability to an iron in the upright position for soft surfaces.
Generally, heel rests for irons are flat, smooth and may contain a plurality of ridges. Such irons are disclosed in Van Surksum, U.S. Design No. 316,621 and 317,519; Gudefin, U.S. Design No. 326,939; Stutzer, et al., U.S. Design No. 349,377; and Simmon, U.S. Design No. 349,378. Irons having a heel rest are also disclosed in Japanese Patent No. 03-075100-A and German Patent No. 20 54 327.
Generally, irons having a generally flat heel rest tend to tip over on a soft padded surface, thus, burning the person ironing the clothes or causing a danger to the household.
SUMMARY OF THE INVENTION
The preferred embodiment of the present invention relates to an iron having a heel rest comprising a recess. The heel rest includes a front and back side. The back side includes a plurality of protrusions for removably fastening the heel rest to the housing of the iron. In addition, the back side may also include a means for removably fastening a portion of the power cord to the heel rest.
The front side of the iron heel rest includes a recess to receive a soft surface, such as the soft padding for an ironing board, fabrics or carpets. In a most preferred embodiment, the iron heel rest is generally shaped in a trapezoidal form. The flat portion of the recess is also generally trapezoidal in shape, with an inwardly sloping perimeter surface located between the circumference of the heel rest and the flat surface of the recess.
It is an object of the present invention to provide an iron which overcomes the problems of the prior art.
It is a further object of the present invention to provide an iron comprising a heel rest having a recess in which the iron will be less likely to tip over while in its upright position on a soft surface.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of an iron comprising a heel rest of the present invention.
FIG. 2 is a rear elevational view of an iron comprising a heel rest of the present invention.
FIG. 3 is an exploded perspective view of an iron comprising the heel rest of the present invention.
FIG. 4 is a rear elevational view of the heel rest.
FIG. 5 is a cross-sectional view of the heel rest of FIG. 4, taken generally long line 1--1 of FIG. 1, and showing details of the recess.
FIG. 6 is an elevational view of the bottom portion of the iron in its upright position comprising the preferred embodiment of a heel rest of the present invention wherein a soft surface is disposed within the recess.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 shows one embodiment of an electric steam iron 10 comprising a heel rest 50 of the present invention.
FIG. 3 illustrates an exploded view of the iron 10 of FIGS. 1 and 2. The iron 10 comprises a soleplate 20, a heating element 26, a housing 30, a pump assembly 40, a steam control assembly 42, and the heel rest or rear cover 50 of the present invention. Of course, the heel rest 50 of the present invention may be adapted to be fastened to any type of iron. In addition, the heel rest 50 may be made of any material such as ABS plastic, polypropylene, wood, metals, etc.
As shown in FIG. 3, the soleplate 20 comprises a metal material and also a heating element 26 mounted in good heat conducting relationship therewith. The soleplate 20 also has a bottom face or pressing surface 22 adapted to be placed in contact with a suitable fabric to be ironed.
In a preferred embodiment, the housing 30 of the iron 10 comprises a top cover 32, a handle 34, a tank 36, and a skirt 38. The soleplate 20 is secured to the other parts of the housing 30 such as the skirt 38 through the use of screws, flanges, or any other conventional means for fastening.
The tank 36, which may be filled with an aqueous solution such as water, is removably connected to the skirt 38. Water contained in the tank 36 may be delivered to the soleplate 20 where it is converted to steam in a well-known manner. The water delivery is controlled by a steam setting control 42, which controls a steam valve. The tank 36 which fits between the skirt 38 and handle 34 is completely encapsulated by the handle 34, which fits over the skirt 38.
A pump assembly 40 fits between the handle 34 and the top cover 32. The pump assembly 40 draws water from the tank 36 and delivers a spray of water to dampen the fabrics to be ironed.
The top cover 32 fits over the handle 40 and a fastening means 44 is provided such as a screw to secure the top cover 32 to one or more parts of the housing 30 or the soleplate 20. The power cord assembly 46 is either fixably or removably attached to the heating element 26 and may also be removably secured to the heel rest 50 by a power cord assembly fastening means 48 such that the power cord assembly 46 extends outward between the heel rest 50, the top cover 32 and the handle 34.
As shown in FIG. 3, in a most preferred embodiment, the back side 52 of the heel rest 50 of the present invention includes a pair of engaging lower tail pieces 54 having respective apertures 56 located in the skirt 38 for engagement with the skirt 38. In addition, the heel rest 50 may also contain tail pieces or protrusions 58 to engage the heel rest 50 with the top cover 32 or handle 34 or both. Any number of tail pieces or protrusions 54, 58, however, can be used to fasten the heel rest 50 to the housing 30 of the iron 10. In addition, other means for fastening the heel rest 50 to the iron 10 are also contemplated, e.g. screws, nails, clips, flanges, etc.
As shown in FIG. 4, the front side 60 of the heel rest 50 embodies the main feature of this invention. In a preferred embodiment, the heel rest 50 is contained in a trapezoidal shape having rounded off corners. Of course, any shape such as a square, triangle, polygon, or circle may be utilized.
As shown in FIG. 5, the thickness (w) of the heel rest 50 excluding the fastening protrusions may be any length from 1 mm to 5 cm. In a most preferred embodiment, the thickness (w) is 4.5 mm.
In a preferred embodiment, illustrated in FIG. 5, the heel rest 50 has a rounded edge 62 which confronts an inwardly beveled perimeter portion 90. The perimeter portion 90 slopes inwardly toward a planar recessed surface 70 at an angle (x) ranging from 2 degrees to 15 degrees. The outer radius of the front side is less than the outer radius of the back side. In a most preferred embodiment, this angle is 2 degrees.
From the front side 60 of the heel rest 50, the perimeter portion preferably slopes toward the center of the front side of the heel rest at an angle (y) ranging from 2 degrees to 10 degrees for a certain distance until the recess 70 comprises a depth (z) of approximately 1.0-3.0 mm. In a most preferred embodiment, the angle (y) is 4 degrees, and the depth (z) is approximately 2.5 mm.
As shown in FIG. 4, at the bottom portion 64 of the heel rest 50, the distance (a) from the outer radius 62 to the flat portion 66 of the recess 70 is approximately 22.0 mm. In the side portion 68 and upper portion 72, the distance (b) from the outer radius 62 to the flat portion 66 is approximately 17.0 mm. Preferably, the sides 76 of the flat portion 66 of recess 70 are parallel to the outer radius 62 of the heel rest 50.
In a most preferred embodiment, the height (c) of the heel rest 50 is approximately 126.24 mm. The width (d) of the front side 60 of the heel rest 50 is approximately 116.4 mm. Of course, the heel rest 50 of the present invention can also be implemented in heel rests of differing heights and widths.
In addition, an opening 80 may be included in the top portion of the heel rest 50 to allow a power cord assembly to protrude outwards.
As shown in FIG. 6, the iron 10 is resting on its heel rest 50 in the upright position. As the weight of the iron forces the soft surface downwards, the portion of the soft surface directly underneath the recess moves upward to fill in the recess. As a result, the soft surface in the recess acts as a barrier in the recess to prevent the iron from tipping over.
EXAMPLE 1
An experiment was performed to determine the improved degree of stability in an iron using a heel rest of the present invention. The iron incorporating the heel rest of the present invention was designated as Sunbeam Products, Inc. ("SUNBEAM") STEAMMASTER 2 type irons. In particular, STEAM MASTER 2, Model No. 4048 was tested.
The stability test was performed using five (5) different irons, each from a different manufacturer. The five irons are:
A=Sunbeam Model No. 4048 (STEAM MASTER 2);
B=Rowenta Model No. DE 44 (SURFLINE);
C=Proctor Silex Model No. 17260;
D=Tefal Model No. 1960 (ULTRAGLIDE ELITE 60);
E=Panasonic Model No. NI-432E.
The test was performed three times. The results shown in Table 1 are an average of all three tests.
The test was set up in the following manner:
Each unit was filled with water to its maximum level. Next, the unit was placed in an upright position on its heel rest onto a 0.200 inch thick rubber pad, which was placed on top of a table. The side of the table directly opposite the soleplate was raised until the unit moved from its upright position to a vertical position. After the unit moved, the angle of the table top was lowered to find the most accurate point of movement. The unit was then rotated to find another direction that might cause the iron to move. If another direction was found, the angle of the table top was lowered until the unit would stop moving. The unit would then be rotated again until no new direction was found which could cause movement of the iron. The angle was then recorded.
In Table 1, a diagram of the test results are shown. The rectangle corresponds to a table top, which has been divided into quadrants. The table top is oriented so that the back edge is marked by line A. The "X" marks the direction of the base plate. In this diagram, the degree of the angle at which the unit tips over is shown.
As shown in Table 1, the STEAM MASTER 2 iron, which contained the heel rest of the present invention, tipped over when the table top was raised to an angle of 19.6 degrees. The next closest unit in terms of performance was the Proctor-Silex unit which tipped over at an angle of only 14.5 degrees. Accordingly, the STEAM MASTER 2 iron was significantly superior than the other four units in remaining in an upright position.
Although the invention has been described in detail in the foregoing for purposes of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those of ordinary skill in the art, without departing from the spirit and scope of the invention as defined by the claims. Such variations are specifically intended to be embraced by the scope for the following claims and by all equivalents thereof.
TABLE 1______________________________________ #STR1## #STR2## ##STR3##______________________________________ | The present invention relates to a heel rest for an iron. More specifically, the heel rest of the present invention, comprises a recess to improve the stability of an iron in its upright position on a soft surface, such as a padded ironing board or carpet. As the iron is placed in the upright position, the weight of the iron presses down upon the soft surface and causes the soft surface located directly under the recess to rise and fill in to the recess. | 3 |
BACKGROUND OF THE INVENTION
The cooling of high power electronic modules carried on a circuit board has always been a troublesome problem. It is possible to use a liquid coolant pumped through pipes in contact with a heat sink to remove the heat they generate. However, such an approach requires relatively complex tubing and the expense of an external chiller to accept the heat carried by the coolant. It is therefore desirable to use ambient air to cool these modules. Because the high heat generation of such modules makes free convective cooling insufficient, forced convective cooling is necessary.
Forced convective cooling has the advantages of simplicity and cost effectiveness. Because of the typical layout of circuit boards and the modules carried by them, the usual procedure is to introduce air at one edge of the circuit board and force it across the many modules carried on the board to cool them. However, the air which passes near the first modules is heated, lessening its ability to cool those modules which it encounters later as it flows around them. Therefore, there have been attempts made to implement so-called "parallel" cooling or air flow, where air is distributed to the modules involved before it has been warmed by any other of the modules. These designs, however, cannot always transfer enough heat to the air passing by them to keep the temperature of the module within the safe region.
PRIOR ART STATEMENT
U.S. Pat. No. 4,296,455 teaches the use of tubes attached to a module through which air is blown in a parallel mode from a plenum. U.S. Pat. No. 2,380,026 discloses plates located in the mouths of ducts through which air is forced from a common source. U.S. Pat. No. 3,198,990 shows a honeycomb structure having heat producing electronic elements inserted in individual cells, each element having axial leads to which interconnecting wires are connected. Air is blown through the honeycomb structure to directly cool the elements. U.S. Pat. Nos. 4,158,875; 3,790,859; and 4,103,737 show other approaches to cooling of electronic components.
BRIEF DESCRIPTION OF THE INVENTION
To solve the problems mentioned above, this cooling structure includes an individual heat sink assembly for each module with high enough heat transfer characteristics so that the typical module dissipating 1-5 watts can be easily cooled with ambient air flow. A heat sink which has longitudinal fins of high thermal conductivity joined at a central axis is attached in intimate thermal contact at one end, to each electronic module. Each heat sink projects substantially perpendicularly from the circuit board. An air plenum having an air guiding side preferably shaped to conform to the contour of the circuit board is supported in spaced apart relation from the side of the circuit board on which the heat sinks are mounted. The air guiding side has a plurality of hollow tube sections which communicate with the interior of the plenum. Each tube extends toward and partially encloses one heat sink. The end of each tube section is substantially sealed to the air guiding side of the air plenum, so that no air can leak from the plenum between the air guiding side and the individual tubes. A fan or other air pump either blows air into the plenum or draws air from the plenum so as to cause air to rush along the fins of the individual heat sinks, thereby cooling them. Since relatively rapid air flow over a large heat sink area occurs, heat transfer from the fins to the air stream is relatively efficient. The air so heated is simply ejected to the atmosphere. No heat sink depends for its cooling on air which has already passed by another heat sink.
Accordingly, one purpose of this invention is to eliminate the possibility of hot spots within an electronic chassis.
Another purpose is to permit sources of relatively large amounts of heat to be packed with densities higher than previously was possible when employing ambient air cooling.
Another purpose is to standardize the amount of heat which is removable from an individual electronic module.
Still another purpose is to maintain all the modules of similar heat dissipation on a circuit board at very nearly the same temperature, independent of variations in temperature of other modules.
Other purposes and effects of this invention will be apparent from the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an electronic circuit board assembly employing the cooling structures of this invention.
FIG. 2 is a detailed perspective drawing of one of the cooling structures shown in FIG. 1.
FIG. 3 is a perspective drawing of the plenum and the outside of its air guiding side.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning first to the structure shown in FIG. 1, a flat circuit board 13 contains on one side a series of electronic modules 14. These may be placed in the rectangular grid pattern shown, or have a more irregular arrangement. Circuit board 13 contains the interconnections between the various modules 14. Circuit board 13 is mounted on a base or chassis 10. The structure within each module 14 must efficiently transport heat generated by the heat generating elements within module 14 to a heat sinking surface 22 of module 14 so that the heat can be removed in some fashion. A heat sink 15 is attached at one of its ends in intimate thermal contact with the heat sinking surface 22 of module 14. Heat sink 15 projects from surface 22 preferably perpendicularly to circuit board 13.
In FIG. 2, the heat sink 15 is shown in greater detail. It preferably comprises a plurality of axially oriented fins 17 projecting perpendicularly from module 14 and board 13, all of which intersect at a center 18. It is important that the ends of all the fins be in intimate thermal contact with the heat sinking surface 22 of module 14.
The air plenum 11 shown in FIG. 1, has an air guiding side 19 (shown in FIG. 3) facing the heat sinking surfaces 22 of modules 14. A part of this air guiding side 19 is also shown in greater detail in FIG. 2. Side 19 is generally shaped to conform to the contour of circuit board 13 and thus is flat in this example, and is held by plenum 11 in facing, spaced apart relationship with the side of the circuit board 13 carrying the heat sinks 15. Plenum 11 is in turn carried by supports 21 on base 10. A fan or blower 12 in a side of plenum 11 creates a pressure difference between the interior of plenum 11 and the ambient. Air guiding side 19 need not conform to the contour of circuit board 13, but the structure is easier to design and is more compact if this is the case.
Air guiding side 19 includes a plurality of tube sections 16 each of which communicate with the interior of plenum 11. Each tube section 16 extends toward and partially encloses one of the heat sinks 15. Each tube section 16 is substantially sealed to the air guiding side 19, so that air which is drawn into or expelled from plenum 11 by fan 12 is caused to flow only through the pie- or V-shaped channels created between fins 17 and the interior surface of each tube section 16. For best operation each tube section 16 free end should be spaced from its associated heat sinking surface 22 such that the open circumferential area of heat sink 15 between the end of the tube section 16 enclosing it and the surface 22 at its base, is at least equal to the internal cross sectional area of tube 16 less the solid cross sectional area of sink 15, both cross sections being taken perpendicular to tube 16's axis. If this circumferential area is less than this cross sectional area difference, air flow through tube 15 will be restricted, causing reduced heat transfer, partially enclose heat sinks 15. If heat sinks 15 are completely enclosed, then air cannot escape from or enter the channels between fins 17. At any rate, the tube sections 16 must enclose at least about 1/10th of the lengths of heat sinks 17 if fan 12 creats positive pressure within plenum 11. If fan 12 creates negative pressure within plenum 11, tubes 16 must enclose a large fraction of sinks 15. It does not appear that heat transfer between surfaces 22 and sinks 15, and the air streams is particularly sensitive to direction of air flow as long as the tubes 16 enclose the preferred lengths of sinks 15. Probably the fact that air flow from plenum 11 causes air to directly impinge on heat sinking surfaces 22 is approximately balanced by the greater efficiency of heat transfer between the unheated air stream and the relatively hotter bases of sinks 15.
It is obvious that a wide variety of designs can be employed for the heat sinks 15 and the tube sections 16 which enclose them. For example, the center 18 might be a flat plate projecting from surface 14 with fins projecting in turn at angles from it, and whose ends define a rectangular or square pattern. However, experimentation shows that the best design now known is that shown in FIG. 2. Fins 17 project radially from a center portion 18 where fins 17 intersect, and form between individual fins 17 channels which have pie- or V-shaped cross sections. Heat sinks 15 can be easily made as aluminum extrusions.
It is possible that irregularities in the tube sections 16 at the point where air enters them will induce turbulent flow and increased heat transfer. Of course, this will also increase flow resistance, necessitating added capacity for fan 12. This is a design consideration for one wishing to practice this invention.
It is known that the amount of heat transferred between a moving air stream and a heat source is dependent on the air velocity, the area of the source, and the temperature difference between the heat source and the air itself. In the conventional series parallel cooling arrangement, air velocity must be quite high to keep the air temperature rise from being so great that downstream module temperature is too high. High velocity air streams are noisy and the fans which create them are expensive. The high air velocity and large total heat transfer air over which the air flows does allow cooling in many cases, however.
The instant invention takes a different approach. A very high efficiency heat exchanger permits maximum heat absorption by the air stream with totally parallel air flow. The high efficiency is a result of the air being constrained by the tube sections 16 to flow only in close proximity to the heat sinks 15, and by the very large heat sink area. Because the total cross sectional area of the air passages within tube sections 16 is very great and quite short, low fan pressure is sufficient to generate adequate air flow. Low air speed is sufficient, allowing extremely quiet operation and use of small, inexpensive, low power fans. Thus, this invention provides substantial advantages over the past designs.
The preceding describes the invention. | The cooling of electronic modules on a circuit board is improved by the use of heat sinks comprising a plurality of longitudinal fins projecting from the modules. Individual tubes communicating with an air plenum fit around and part way along each heat sink. Air drawn from or forced into the plenum causes air flow within the tubes and along the fins to cool them and the modules to which they are attached. | 7 |
This application is a 371 of PCT/IL97/00427 filed Dec. 25, 1997.
FIELD OF INVENTION
A novel class of compounds has been found to be effective in treating hyperlipidemia, obesity and impaired glucose tolerance/noninsulin dependent diabetes mellitus without adversely affecting energy metabolism. The active compounds have the general formula
R 1 -R 4 each independently represents a hydrogen or an unsubstituted or substituted hydrocarbyl or heterocyclyl radical;
where R 5 and R 6 independently represent hydrogen, hydroxyl, lower alkyl, chloro, bromo, cyano, nitro, lower alkoxy, or trifluoromethyl
Q represents a diradical consisting of a linear chain of 2 to 14 carbon atoms, one or more of which may be replaced by heteroatoms, said chain being optionally substituted by inert substituents and one or more of said carbon or heteroatom chain members optionally forming part of a ring structure and where one or both of the carboxyl groups can be substituted by an in vivo hydrolyzable physiologically acceptable substituent.
The invention also provides pharmaceutical compositions comprising the aforementioned compounds of formula (I) for the treatment of obesity, hyperlipidemia and maturity-onset diabetes.
BACKGROUND OF THE INVENTION
Dyslipoproteinemia (combined hypercholesterolemia-hypertriglyceridemia), low HDL-cholesterol), obesity (in particular upper body obesity), impaired glucose tolerance (IGT) leading to noninsulin-dependent diabetes mellitus (NIDDM)) and essential hypertension are common diseases that afflict individuals living in Westernized societies. Being initiated and linked through hyper-insulinemia these four diseases often coexist and precipitate independently as well as synergistically atherosclerotic vascular disease leading to coronary heart disease. The incidence of the Deadly Quartet (Syndrome-X, Metabolic Syndrome) comprising the four diseases increases as the population ages and by 70 years of age reaches epidemic proportions. Combatting the individual categories of the Deadly Quartet as well as offering a whollystic therapeutic approach to the Syndrome is considered one of the most important challenges of medicine in affluent Westernized society.
Many hypercholesterolemic/hypertriglyceridemic individuals turn out as low- or non-responders to dietary measures and therefore are candidates for long-term treatment with hypolipidemic drugs. HMG-CoA reductase inhibitors and bile acid sequestrants designed to upregulate the LDL receptor are very effective in isolated hyper-cholesterolemia. However, both are ineffective in reducing plasma triglycerides and poorly effective in increasing plasma HDL, thus being short of offering an adequate treatment mode for combined hypertriglyceridemia-hypercholesterolemia (which comprise of >70% of dyslipoproteinemic patients) or for isolated hypertriglyceridemia with reduced plasma HDL, as well as for the postprandial chylomicrons-rich phase realized now as an independent risk for atherosclerotic cardiovascular disease. Isolated hyper-triglyceridemia may however be treated with either nicotinic acid or drugs of the fibrate family. However, the compliance for nicotinic acid is very poor and the advantage of fibrate drugs in lowering overall mortality has been seriously questioned since the exhaustive WHO clofibrate study. Also, nicotinic acid is ineffective while fibrate drugs are only poorly effective in reducing plasma cholesterol, thus leaving the combined hypertriglyceridemic-hypercholesterolemic patient with the only choice of a combination treatment mode (e.g., HMG-CoA reductase inhibitor/nicotinic acid). Weight reduction measures are essentially based on promoting dietary or behavioral means for reducing weight. However, most obese individuals turn out to respond inadequately to dietary or behavioral measures, especially if examined over long time periods. The chances for 5-year maintenance of weight reduction initiated by dietary and behavior modifications are less than 10%. This overwhelming failure is mainly metabolic, since the decrease in weight as a result of dieting is always accompanied by a decrease in basal metabolic rate and overall energy expenditure, thus forcing the dieting obese patient into a genuine deadlock. Antiobesity drugs based on modulating energy intake are currently based on anorectics designed to depress the hypothalamic satiety center. These drugs are reported to be ineffective in the medium and long range and some may induce primary pulmonary hypertension. Similarly, no antiobesity drugs are presently available based on modulating total body calorie expenditure while allowing free access to calorie consumption. Peripherally acting thermogenic β3-adrenergic agonists are selected on the basis of their capacity to stimulate brown adipose tissue β-adreno receptors and may indeed induce thermogenesis in rodents. However, the efficacy of such agents in humans while allowing free access to calories is still questionable and their ;broad tissue specificity (e.g., skeletal muscle, myocardium, colon) may be expected to result in nonspecific-adrenergic-induced effects.
Presently available pharmacological measures for treating IGT and overt NIDDM consist of two oral hypoglycemic drug types which are in use for over 30 years. The sulphonylureas promote pancreatic insulin secretion for coping with peripheral insulin resistance, while biguanides are claimed to improve peripheral insulin action. The popularity of sulphonylurea does result from the old conviction that blood glucose which precipitates the diabetic microvascular disease in retina kidney, nerve and some other tissues should be normalized by all means even at the expense of increased pancreatic insulin secretion. This therapeutic approach was initiated in times when the hyperinsulinemic phase dominating the natural history of the development of NIDDM or the course of obesity-induced IGT was not realized, neither the pathological sequel dictated by sustained hyperinsulinemia. Moreover, the sulphonylurea (similarly to insulin) tend to promote weight gain, thus further promoting insulin resistance and compensatory hyperinsulinemia leading to diabetes-induced macrovascular disease (atherosclerotic cardiovascular disease). Biguanides are claimed to potentiate insulin-mediated glucose disposal with no stimulation of pancreatic insulin secretion. However, the use of biguanides as monotherapy is not unanimously recommended except for the very obese in light of their low therapeutic/toxicity index and the induction of lactic acidosis. During the period of the last ten years, the scientific community became progressively aware of the etiological-pathophysiological linkage between dyslipo-proteinemia, obesity, NIDDM, hypertension, decreased fibrinolysis and some other pathologies (e.g., hyperuricemia), realizing now that the concerned pathologies are just reflections of a unifying Syndrome. Leading to atherosclerotic cardiovascular disease, the Syndrome is realized now to be the major risk factor for mortality and morbidity in Western Societies. Treating the Syndrome pharmacologically calls for an whollystic approach rather than dealing separately with each of its distinct categories. No drug designed alongside these principles is yet available.
α, ω-Dialkanoic acids of chain length of 14 20 carbon atoms which are hydrocarbyl substituted on the β,β′ carbon atoms, as well as their salts and ester derivatives were disclosed in Bar-Tana U.S. Pat. Nos. 4,634,795, 4,689,344 and 4,711,896 as possessing a hypolipidemic, weight reducing and antidiabetogenic activity. Realizing however that treatment of the Metabolic Syndrome and its related pathologies would require chronic dosing has initiated an exhaustive search for new compounds having a higher efficacy as compared with the previously disclosed β,β′-substituted α,ω dialkanoic acids.
DESCRIPTION OF THE INVENTION
A novel class of compounds has now been found, in accordance with the present invention, to be surprisingly effective in reducing blood lipids. The new compounds of the invention were also found to have a calorigenic antidiabetic (NIDDM) activity without adversely affecting energy metabolism. Furthermore, the efficacy of some of these compounds is far better as compared with previously reported β,β′-substituted α,ω-dialkanoic acids. The novel compounds provided by the present invention are α,ω-dialkanoic acids having the general formula
and in vivo hydrolysable functional derivatives of the carboxylic groups thereof, wherein R 1 -R 4 each independently represents a hydrogen or an unsubstituted or substituted hydrocarbyl;
where R 5 and R 6 independently represent hydrogen, hydroxyl, lower alkyl, chloro, bromo, cyano, nitro, lower alkoxy, or trifluoromethyl;
Q represents a diradical consisting of a liner chain of 2 to 14 carbon atoms, one or more of which may be replaced by heteroatoms, said chain being optionally substituted by inert substituents qnid one or more of said carbon or heteroatom chain members optionally forming part of a ring structure.
Included within the scope of the invention are those derivatives of the α and/or ω carboxy groups of the compounds of formula I above, which are capable of being hydrolyzed in vivo to yield the free diacids of formula I. Among such suitable derivatives there should be mentioned. in the first place salts with pharmaceutically acceptable inorganic or organic cations, in particular alkali metal salts, alkaline earth metal salts, ammonium salts and substituted ammonium salts; esters, particularly lower alkyl esters; amides, mono- and di-substituted amides; and anhydrides, e.g., with lower alkanoic acids; and lactones formed by ring closure of either or both carboxylic groups with a free hydroxy substituent (or substituents) in the molecule of formula (I).
The term “hydrocarbyl” in the definition of R 1 -R 4 includes, e.g., optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, optionally substituted aryl, optionally substituted aralkyl and the like.
A preferred group of compounds in accordance with the invention are those of formula (I) above in which R 1 -R 4 are each lower alkyl and Q is a straight polymethylene chain of 2 to 14 carbon atoms; and in vivo hydrolysable functional derivatives thereof.
Especially preferred compounds of the present invention are those of the general formula
and their in vivo hydrolysable functional derivatives, wherein n is an integer from 6 to 12;
or of the general formula
where n is an integer from 10-16; and their in vivo hydrolyzable function derivatives.
The novel compounds of formula (I) according to the invention, can be prepared by methods knownper se, some of which are illustrated in the examples herein.
In another aspect, the present invention provides pharmaceutical compositions for the treatment of obesity, hyperlipidemia, diabetes or the Metabolic Syndrome, comprising as active ingredients the novel compounds of formula (I) above together with pharmaceutical carriers or diluents. The pharmaceutical compositions are primarily for oral administration, but may also be for parenteral or topical administration. These pharmaceutical compositions, which are preferably in dosage unit form, may be in the form of, e.g., tablets, capsules, lozenges, pills, powders and aqueous and non-aqueous solutions or suspensions. The pharmaceutical compositions of this invention preferably comprise also conventional pharmaceutical solid or liquid carriers or diluents, e.g., gelatin, sugars, starches, cellulose derivatives, fatty acids and their salts, vegetable oils, glycerine, glycols, water, aqueous saline or phosphate buffer solutions and the like. The compositions may also comprise other compatible substances normally used in pharmaceutical formulations and also other additives, such as colouring agents, flavouring agents and preservatives.
The pharmaceutical compositions according to the invention are preferably in dosage unit form, each unit containing from 50 to 500 mg of the active ingredient of the formula (I) above. The daily dosage of the compounds of formula (I) above according to the invention will depend on the age, needs and tolerance of the individual patient, but will usually range from 50 mg to from 5,000 mg per day.
The pharmacological activities of the compounds of formula (I) according to the invention could be demonstrated by means of in vivo experiments in rats and in vitro experiments in liver cells in accordance with standard methods. Some of these experiments are described hereinafter in detail.
EXPERIMENTS IN RATS IN VIVO AND IN LIVER CELLS
E XPERMN I
Rats (n=5 for each treatment group) were fed ad libitum on Purina chow for 6 days, the diet being supplemented with 0.1% (w/w) γ,γ′-methyl substituted α,ω-dioic acids of formula (II) (Ex. 1, Ex. 3, Ex. 4) in the diet. The biological effect in vivo was evaluated by following food intake, plasma triglycerides, plasma cholesterol and plasma glucose. The results are shown in the following Table I.
TABLE I
Nontreated
Ex. 1
Ex. 3
Ex. 4
Plasma
63.9 ± 24.1
24.8 ±
28.8 ± 7.4
29.3 ± 10.4
tri-
3.9
glycerides
(mg %)
Plasma
66.3 ± 5.6
64.1 ±
62.4 ± 13.3
56.8 ± 10.8
cholesterol
12.0
(mg %)
Plasma
141.2 ± 10.7
127.8 ±
138.8 ± 2.7
139.0 ± 9.0
glucose
6.6
(mg %)
Food
19.1 ± 1.7
18.6 ±
19.3 ± 1.1
19.1 ± 1.2
intake
2.1
(g/d)
E XPERIMENT II
Rats (n=5 for each treatment group) were fed ad libitum on purina chow for 5 days, the diet being supplemented with either γ,γ′-methyl substituted α,ω hexadecanedioic acid (formula (II), Ex. 3) or β,β′-methyl substituted α,ω-hexadecanedioic acid (U.S. Pat. No. 4,634,795) at a dosage of 0.09% (w/w) in the diet. The biological effect in vivo was evaluated by following plasma triglycerides, plasma apolipoprotein(apo)C-III, plasma insulin and the steady state concentrations (Css) of the respective drugs in plasma. Fold efficacy of the γ,γ′-sbstituted compound (Ex. 3) relative to the β,β′-substituted compound was calculated by normalizing the observed effect by the respective Css attained. The results are shown in the following Table II.
TABLE II
γ,γ′-methyl-
Fold
β,β′-methyl-
hexadecane
efficacy
hexadecane
α,ω-dioic acid
(γ,γ/
Nontreated
α,ω-dioic acid
(Ex.3)
β,β)
Plasma
61.0 ± 13.5
19.7 ± 4.0
19.9 ± 7.4
8.2
triglycerides
(mg %)
Plasma apo
33.0 ± 10.0
11.0 ± 3.7
12.0 ± 4.6
7.7
C-III (mg %)
Plasma insulin
31.0 ± 6.5
23.0 ± 3.4
16.0 ± 6.1
15.2
(U/ml)
Css (g/ml)
97.4 ± 12.6
12.0 ± 1.2
E XPERIMENT III
Conditions as in E XPERIMENT II using α,α′-methyl-substituted α,ω-tetradecanedioic acid. The results are shown in the following Table III.
Fold efficacy represents the respective effect induced by the α,α′-substituted compound (Ex. 5) relative to that of the β,β′-substituted compound.
TABLE III
α,α′-methyl-
β,β′-methyl-
hexadecane
hexadecane
α,ω-dioic acid
Fold
Nontreated
α,ω-dioic acid
(Ex.6)
efficacy
Plasma
211.2 ± 81.5
79.5 ± 9.2
44.5 ± 14.0
1.78
Triglycerides
(mg %)
Plasma
101.5 ± 15
84.0 ± 9.3
69.5 ± 9.7
1.2
Cholesterol
(mg %)
Plasma apo
276 ± 31
63 ± 10
17 ± 14
C-III (mg %)
Plasma glucose
112 ± 5
114 ± 6
104 ± 4
1.1
(mg %)
Plasma insulin
28.9 ± 13.1
25.4 ± 5.
24.2 ± 7.3
1.0
(U/ml)
E XPERIMENT IV
Uncoupling of oxidative phosphorylation by compounds of formula I was evaluated in isolated liver cells loaded with JC-1 dye (as described by M. Reers et al., Meth. Enzymol. 260, 406 (1995))) and incubated in the presence of added compounds of formula I as specified. JC-1 fluorescence was determined by FACSCAN flow cytometry. While the cytosolic monomeric dye emits at 530 nm (when excited at 488 nm), the fluorescence of the intramitochondrial aggregated dye shifts to 590 nm. The 530/590 fluorescence ratio thus reflects the cytosolic/mitochondrial distribution of the dye as a result of the prevailing mitochondrial inner membrane potential of affected cells. The higher the 530/590 ratio the higher the extent of uncoupling and calorigenesis induced by added effectors. The results are shown in the following FIG. 1 .
SUMMARY
The following conclusions were reached with regard to the biological effects of compounds of formula I:
(a) The active compounds are potent hypolipidemics. The overall hypolipidemic effect is based on activating plasma lipoproteins clearance resulting from decrease in plasma apo C-III.
(b) The active compounds are potent insulin sensitizers as reflected by plasma insulin concentrations required for maintaining euglycemia. Insulin sensitization may form the basis for using these compounds in the treatment of IGT/NIDDM.
(c) The active compounds induce increase in calorigenesis as a result of decrease in mitochondrial membrane potential. Uncoupling induced by these compounds may form the basis for using these compounds in the treatment of obesity.
(d) These compounds may offer an whollystic therapeutic approach for the Metabolic Syndrome. Their efficacy is far higher as compared with homologous β,β′-substituted,compounds.
EXAMPLES
Example 1
4,4,11,11-Tetramethyltetradecanedioic Acid
Ethyl bromoacetate (14.4 g, 0.094 mol) was added dropwise over 30 min to a stirred solution of 26.2 g (0.1 mol) of triphenylphosphine in 120 ml of benzene maintained at 35 38° C. After stirring for additional 12 h at room temperature the precipitate was filtered and washed twice with hexane to give 34.7 g (86%) of (carboethoxymethyl)-triphenylphosphonium bromide, m.p. 159 160° C. 115 ml of 10% aqueous sodium hydroxide was added dropwise with cooling at 5° C. to a stirred suspension of 118.4 g (0.276 mol) of the bromide in 500 ml of water and 200 ml of chloroform containing a small amount of phenolphthalein. Stirring was continued over 30 min. period without external cooling followed by adding 500 ml of chloroform to give clear layers. The aqueous layer was extracted three times with 100 ml of chloroform and the combined chloroform fractions were dried over sodium sulfate and concentrated in vacuo. Crystallization of the residue from 180 ml of 1:1 mixture of benzene and hexane gave 86.2 g (90%) of pure (carboethoxymethylene)triphenylphosphorane, m.p. 119 120° C.
Potassium carbonate (56 g) was added portionwise over 1 h to a stirred mixture of 68 g (0.94 mol) of freshly distilled isobutyraldehyde and 70 ml of 40% formalin under argon. During addition the temperature was kept at 10 15° C. The temperature was allowed to rise to 25° C. while stirring was further continued under argon for 12 h, followed by adding 100 ml water to the white suspension.
The mixture was extracted four times with 40 ml of chloroform and the combined extracts were dried over magnesium sulfate and concentrated in vacuo.
Distillation of the remaining liquid (solidified upon cooling) through a 20-cm
Vigreux column gave 93.0 g (97%) of 2,2-dimethyl-3-hydroxy-propanol, b.p. 83 860 C/15 Torr, m.p. 90 93° C.
A solution of 2,2-dimethyl-3-hydroxypropanal (22 g, 0.22 mol) and (carboethoxymethylene)triphenylphosphorane (75 g, 0.22 mol) in dry dichloromethane (150 ml) was refluxed for 46 h. The solvent was then evaporated and the crude product was distilled at 15 Torr through a very short column. The distillate was separated into two fractions by redistillation through a 40-cm Widmer column. The first fraction gave 22.3 g (60%) of ethyl trans-4,4-dimethyl-5-hydroxypent-2-enoate, b.p. 133 136° C./15 Torr, nD23 1.4641. 1H NMR (CDCl 3 ): (=1.10 [s, 6H, C(CH 3 ) 2 ], 1.25 (t, 3H, CH 3 CH 2 ), 3.40 (s, 2H, CH 2 ), 3.80 (br. s, 1H, OH), 4.15 (q, 2H, CH 2 CH 3 ), 5.80 (d, 1H, J=16 Hz, 3-H). Anal. Calad. for C 9 H 16 O 3 : C, 62.76; H, 9.36. Found: C, 62.92; H 9.50.
Ethyl trans-4,4-dimethyel-5-hydroxpent-2-enote (8.6 g, 0.05 mol) in 100 ml of dichloromethane was added to a strred suspension of 70 g (0.27 mol) of chromium trioxide-pyridine complex in 900 ml of anhydrous dichloromethane. The insoluble black gum residue was washed thoroughly three times with 100-ml portions of ether. The combined organic solutions were passed through a column (3.5-cm, 25-cm) of Silicagel and the solvent was removed by distillation. Distillation of the residue oil through a 20-cm Widmer column gave 8.0 g (94%) of ethyl 4-methyl-4formylpent-2-enoate, b.p. 110 111° C./15 Torr, nD18 1.4605. 1H NMR (CDCl 3 ): (=1.30 [s, 6H, C(CH 3 ) 2 ], 1.45 (t, 3H, CH 3 CH 2 ), 4.15 (q, 2H, CH 2 CH 3 ), 5.85 (d, 1H, J=16 Hz, 3-H), 6.90 (d, 1H, J=16 Hz, 2-H), 9.45 (s, 1H, CHO). Anal. Calcd. for C 9 H 14 O 3 : C, 63.51; H, 8.29. Found: C, 63.53; H, 8.38. 8.64 g (0.04 mol) of dibromobutane and five drops of formnic acid were added to a solution of 26.2 g (0.1 mol) of tiphenyiphosphine in 125 ml of dimethylformamide and the mixtu(e was refluxed for 3 h, then cooled and diluted with 150 ml of ether. The formed precipitate was filtered off, washed with ether and dried. The crude product was dissolved in 35 ml of methanol and precipitated with 80 ml of ether to yield 25.2 g (85.2% yield) of butane-1,4-bis(triphenylphosphonium)dibromide, m.p. 302 303° C.
Butane-1,4 bis(triphenyl-phosphonium)dibromide (13.4 g, 0.018 mol) (dried over phosphorus pentoxide at least for 3 days) and 600 ml of dry tetrahydrofuran (refluxed over lithium aluminum hydride and distilled at atmosphere pressure) were placed in a dry 1-L three necked flask flushied with argon and vigorously stirred under argon until a fine suspension was formed. Then 20 ml of 1.80 M solution of phenyllithium in ether was added dropwise during 1 h. The red solution was stirred at room temperature for 4 h and 6.12 g (0.036 mol) of ethyl 4-methyl-4-formylpent-2-enoate was added in one portion. The resulting white suspension was stirred at room temperature for 10 h and refluxed for 2 h. The reaction mixture was filtered and concentrated to yield a yellow viscous oil. After addition of 150 ml of ether to the oil, the solution was filtered once more.
The filtrate was concentrated to yield 5.82 g of an oil that was diluted with 30 ml of toluene and filtered through Al 2 O 3 and Silicagel eluted by toluene. The solvent was evaporated to give 3.82 g of diethyl 4,4,11,1 l-tetramethyltetradeca-2,5,9,12-tetraenedionate.
A solution of 2.98 g (8.1 mmol) of diethyl 4,4,11,11-tetramethyltetradeca-2,5,9,12-tetraenedionate in 50 ml of methanol was hydrogenated with 0.2 g of Pt (prepared according to R. Adams, V. Voorhees and R. L. Shriner, Org. Synth. 8, 92 (1928)) until the tieoretical volume of hydrogen had been absorbed. The filtrate was concentrated to yield an oil that was diluted with 30 ml of toluene and filtered through Al 2 O 3 and Silicagel eluted by toluene. The solvent was evaporated to give an oil. 25 ml of 25% NaOH solution and several drops of ethanol were added to the resulting oil, the resulting mixture was heated for 2 h at 50-60 ° C., acidified with conc. HCl and extracted with chloroform. The combined chloroform extracts were dried over sodium sulfate. After distilling off the solvent the residue was recrystallized from hexane to give 2.06 g (81%) of 4,4,11,11-tetramethyl-tetradecanedioic acid, m.p. 88-89° C. 1H NMR (CDCl 3 ): (=0.86 [s, 12H, —C(CH 3 ) 2 ], 1.05 1.38 (m, 16H, CH 2 ), 1.52 (m, 4H, 3,12-CH 2.30 (t, 4H, 2,13 CH 2 ), 9.50 (br. s, 2H, COOH). Anal. Calcd for C 18 H 34 O 4 : C, 68.75; H, 10.90. Found: C, 68.95; H, 10.96.
Example 2
Diethyl 4,4,13,13-tetramethylhexadeca-2,5,11,14-tetraenedionate
4.88 g (0.02 mol) of 1,6-dibromohexane and one drop of formic acid were added to a solution of 13.1 g (0.05 mol) of triphenylphosphine in 60 ml of dimethylformamide and the mixture was refluxed for 3 h, then cooled and diluted with 20 ml of ether. The formed precipitate was filtered off, washed with 30 ml of ether and dried. The crude product was dissolved with heating in 25 ml of methanol and precipitated with 40 ml of ether to yield 12.6 g (82.0%) of hexane-1,6-bis(triphenylphosphonium) dibromide, m.p. 312-313° C.
Hexane-1,6 bis(triphenyl-phosphonium) dibromide (8.28 g, 0.011 mol) (dried over phosphorus pentoxide at least for 36 h) and 550 ml of dry tetrahydrofuran (refluxed over lithium aluminum hydride and distilled at atmosphere pressure) were placed in a dry 1-L three necked flask flushed with argon and vigorously stirred under argon until a fine suspension was formed. Then 17 ml of 1.375 M solution of phenyllithium in ether was added dropwise during 30 min. The red solution was stirred at room temperature for 4 h and 3.6 g (0.021 mol) of ethyl 4-methyl-4-formylpent-2-enoate (prepared as in Ex. 1) in 50 ml of dry tetrahydro-furan was added in one portion. The resulting white suspension was stirred at room temperature for 10 h and refluxed for 2 h. The reaction mixture was filtered and concentrated to yield a yellow viscous oil. After addition of 100 ml of ether to the oil, the solution was filtered once more. The filtrate was concentrated to yield 3.7 g of an oil that was diluted with 20 ml of toluene, filtered through Al 2 O 3 and then chromatographed on Silicagel column (100 g;
eluted by toluene) to yield 25 g (59% yield) of diethyl 4,4,13,13-tetramethylhexadeca-2,5,11,14tetra-enedionate. The ester gave one spot on TLC (Silufol UV 254, CHCl 3 , Rf 0.75). 1H NMR (CDCl 3 ): (=1.18 [s,-12H, C(CH 3 ) 2 ], 1.25 (t, J=6 Hz, 6H, CH 3 CH 2 ), 1.05 1.38 (m, 4H, 8,9-CH 2 ), 1.85 2.05 (m, 4H, 7,10-CH 2 ), 4.15 (q, 2H, J=6 Hz, CH 2 CH 3 ), 5.22 5.30 (m, 4H, 5,6,11.12-CH), 5.75 (d, 2H, J=14 Hz, 3,14-CH), 7.05 (d, 2H, 2,15-CH).
Example 3
4.4,13,13-Tetramethylhexadecanedioic Acid
A solution of 5.43 g (0.014 mol) of Ex. 2 in 50 ml of methanol containing 0.3 g of Pt was hydrogenated and hydrolyzed as described in Ex. 1 to yield 3.52 g (74%) of 4,4,13,13-tetramethylhexadecanedioic acid. m.p. 85 86° C. 1H NMR (CDCl 3 ): (=0.86 [s, 12H, C(CH 3 ) 2 ], 1.05 1.38 (m, 20H, CH 2 ), 1.52 (m, 4H, 3,14-CH 2 ), 2.30 (t, 4H, 2.15-CH 2 ), 9.50 (br. s, 2H, COOH). Anal. Calcd. for C 20 H 38 O 4 : C, 70.13; H, 11.18. Found: C, 70.07; H, 11.02.
Example 4
4,4,15,15-Tetramethyloctadecanedioic Acid
10.88 g (0.04 mol) of 1.8-dibromoctane and five drops of formic acid were added to a solution of 26.2 g (0.1 mol) of triphenylphosphine in 125 ml of dimethylformamide and the mixture was refluxed for 3 h, then cooled and diluted with 150 ml of ether. The formed precipitate was filtered off, washed with ether and dried. The crude product was dissolved in 35 ml of methanol and precipitated with 80 ml of ether to yield 27.1 g (85.2%) of octane-1,8-bis(triphenylphosphonium) dibromide, m.p. 255 257° C. 1H NMR (CDCl 3 ): (=0.7 1.3 [m, 12H, (CH 2 ) 6 ], 3.0-3.3 (m, 4H, 2PCH 2 ), 7.1-7.5 (m, 30H, 2PPh 3 ). Anal. Calcd. for C 44 H 46 Br 2 P 2 : Br, 20.06. Found: Br, 20.22.
Octane-1.8 bis(triphenyl-phosphonium)dibromide (14.34 g, 0.018 mol) (dried in a vacuum desiccator over phosphorus pentoxide at least for 10 days) and 400 ml of dry tetrahydrofuran (refluxed over lithium aluminum hydride and distilled at atmosphere pressure) were placed in a dry 1-L three necked flask flushed with argon and vigorously stirred under argon until a fine suspension was formed. Then 20 ml of 1.86 M solution of phenyllithium in ether was added dropwise during 30 min. The red solution was stirred at room temperature for 2.5 h and 6.12 g (0.036 mol) of ethyl 4-methyl-formylpent-2-enoate (prepared as in Ex. 1) was added in one portion. The resulting white suspension was stirred at room temperature for 14 h and refluxed for 1 h. The reaction mixture was filtered and concentrated to yield a yellow viscous oil. After addition of 150 ml of ether to the oil the solution was filtered once more. The filtrate was concentrated to yield 6.69 g of an oil that was diluted with 30 ml of toluene and filtered through Al 2 O 3 and Silicagel eluted by toluene. The solvent was evaporated to give 4.33 g of diethyl 4,4,15,15-tetra-methyloctadeca-2,5,13,16-tetraenedionate.
A solution of 2.26 g (5.4 mmol) of diethyl 4,4,15,15-tetratnethyloctadeca-2,5,13,16-tetraenedionate in 50 ml of ethanol containing 0.5 g Ni (prepared according to H. Adkins, Org. Syntheses Coll. 3, 180 (1955)) was hydrogenated until the theoretical volume of hydrogen had been absorbed and filtered. The filtrate was processed as described in Ex. 1 to yield 1.24 g (62% yield) of acid, m.p. 71-72° C. 1H NMR (CDCl 3 ): (=0.86 [s, 12H, C(CH 3 ) 2 ], 1.05 1.38 (m, 24H, CH 2 ), 1.52 (m, 4H, 3,16-CH 2 ), 2.30 (t, 4H, 2,17-CH 2 ), 9.50 (br. s, 2H, COOH). Anal. Calcd. for C 22 H 42 O 4 : C, 71.30; H, 11.42. Found: C, 71.35: H, 11.35.
Example 5
2,2,13,13-Tetramethyltetradecanedioic Acid
43 ml (80 mmol) of 1.88 N solution of butyllithium in hexane were added dropwise to 8.1 g (80 mmol) of dilsopropylamine in 60 ml of THF. After stirring during 30 min at the same temperature, 3.5 g (40 mmol) of isobutyric acid was added dropwise. The mixture was warmed gradually to room temperature and stirred for 3 h, then cooled to 15°C. again followed by adding 1,10-dibromodecane (4.5 g, 15 mmol) in one portion. After stirring for 3 h at room temperature the reaction was quenched by 40 ml of 12% hydrochloric acid while cooling with ice water. The aqueous layer was extracted with benzene, washed with water and dried over MgSO 4 . After removing the solvent the residue crystallized. The product was recrystallized from hexane to yield 3.4 g (72%) of 2,2,13,13-tetramethyl tetradecanedioic acid, m.p. 86 87.5° C.
1H NMR (CDCl 3 ) delta 1.18 (s, 12H, CH 3 ), 1.20-1.32 (br. m, 16H, CH 2 ), 1.52 (br. t, 4H, β-CH 2 ).
Example 6
2,2,15,15-Tetramethylhexadecanedioic Acid
3.5 g (40 mmol) of isobutyric acid were added at 15° C. under Ar to a solution of lithium diisopropylamide prepared from 8.1 g (80 mmol) of diisopropylamine in 60 ml of THF and 38.3 ml (80 mmol) of 2.1 N hexane solution of butyllithium.
The mixture was stirred at room temperature for 3 h, and cooled again to 15° C. 3.3 g (10 mmol) of 1,12-dibromododecane were then added in one portion, the temperature was raised gradually to 20° C. and the reaction was stirred overnight. The reaction was quenched in ice by 12% hydrochloric acid, extracted with benzene, washed with water and dried. The product was crystallized from hexane to yield 2.6 g (71%) of 2,2,15,15-tetramethylhexadecanedioic acid, m.p. 90 91° C. Found %: C 69.75; H 11.14; Calcd %: C 70.13; H 11.18. 1H NMR (CDCl 3 ) delta 1.18 (s, 12H, CH3), 1.20-135 (br. m, 20H, CH2), 1.50 (br. t, 4H, β-CH2).
Example 7
2,2,17,17-Tetramethyloctadecanedioic Acid
1,14-Dibromotetradecane was prepared by adding HBr into a solution of 4.0 g (20.6 mmol) of 1,13-tetradecadiene and 0.5 g of benzoyl peroxide in benzene at room temperature. The mixture was stirred for two hours and chromatographed on Al 2 O 3 (4 12 cm) with benzene eluent. 1,14 Dibromotetradecane was isolated and recrystallized from. hexane to yield 6.8 g (93.1%), m.p. 50° C. 2,2,17,17-Tetra-methyloctadecanedioic acid was synthesized by adding dropwise 17.5 ml (30 mmol) of 1.72 N solution of butyllithium in hexane to 3.0 g (30 mmol) of diisopropyl-amine in 40 ml of THF in an Ar atmosphere at 15-5° C. Following 30 min the mixture was cooled to 20° C. and 1.3 g (15 mmol) of isobutyric acid were added. The temperature was gradually increased to 20 C. and stirring was continued for three hours. The reaction mixture was cooled again to −15° C. followed by adding the prepared 1,14-dibromotetradecane (0.2 g, 3.4 mmol) in one portion. The temperature was increased to 20° C. and the reaction was stirred overnight. The reaction was quenched in ice by 12% hydrochloric acid, extracted with benzene, washed with water and dried. The product was crystallized from hexane to yield 1.0 g (80%) of 2,2,17,17-tetramethyloctadecanedioic acid, m.p. 94 96° C. (from hexane). Found So: C 71.10; H 11.40. Calcd %: C 71.30; H 11.42. 1H NMR (CDC13) delta 1.18 (s, 12H, CH3), 1.25 (br. s, 24H, CH2), 1.51 (br. t, 4H, β-CH2). | The present invention relates to a novel class of compounds for treating hyperlipidemia, obesity and impaired glucose tolerance/noninsulin dependent diabetes mellitus without adversely affecting energy metabolism, and pharmaceutical compositions comprising the aforementioned compounds for the treatment of obesity, hyperlipidemia and maturity-onset diabetes. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to the control of certain parasitic weeds and to weed control compositions suitable for this purpose, as well as to certain new chemical compounds possessing the requisite biological activity. More particularly the invention relates to the control of the weeds Striga hermonthica, S. asiatica (lutea), Orobanche crenata, O. ramosa and O. aegyptiaca which are parasitic on certain economically important crops such as sorghum, maize, sugar cane and/or broad beans.
Striga causes serious losses in sorghum production and its control is highly desirable since sorghum is the principal subsistence cereal grain for more than 300 million people living in arid tropcial countries. One of the reasons it is difficult to control this weed is that its seeds can remain viable in the soil for as long as 20 years, only germinating in close proximity to the host plant. Thus, control of Striga by rotation of crops or leaving the sorghum fields fallow for a year or more is ineffective since the seeds germinate only when the host plant is sown and starts to grow. Control by planting "false hosts", i.e. plants which trigger germination of the parasite but which do not act as hosts, is usually uneconomical since such planting must replace the desired crop. Another reason Striga is difficult to control is that since it is parasitic in nature, it draws all its nourishment from its host plant, e.g. sorghum, and is not readily amenable to control by normal weed killers, even those which are selective against certain classes of the weeds.
DESCRIPTION OF THE PRIOR ART
It has recently been shown that germination of the Striga seeds is caused by a substance secreted by the roots of the host plant. This substance has been given the name strigol (Cook et al, J. Amer. Chem. Soc. 1972, 94, 6198) and is represented by the structure ##STR1## Neither its synthesis, which has recently been reported, nor its isolation from the root exudate of the sorghum or other host plant, offers an economic route to control of Striga. However, if a readily available stimulant for the germination of Striga seed were available, such a substance could be used to control Striga by application to the soil containing the dormant seed of the parasite at a time when the host plant was not growing, whereupon the Striga seeds would germinate and, having no host plant to parasitize, would die through lack of nutrition. A similar approach to the control of Orobanche would be attractive.
Cassady and Howie, J.C.S. Chem. Comm. 1974, p. 512 have recently reported the synthesis of certain dilactones related to strigol. These authors coupled the sodium enolate salt of 2-hydroxymethylene-γ-butyrolactone with 4-bromobut-2-enolide or with its 5-methyl derivative to yield compounds of the structure ##STR2## wherein R is hydrogen or methyl.
SUMMARY OF THE INVENTION
The present invention is based on the discovery of certain chemical compounds which are able to act as germination stimulants for the seeds of Striga hermonthica, S. asiatica, Orobanche crenata, O. ramosa and O. aegyptiaca, and which are comparatively easily synthesized. According to the present invention, there is provided a method for controlling at least one of the above named parasitic weeds by contacting dormant seeds thereof, in the absence of an actively growing host plant, with a compound corresponding to one of the formulae ##STR3## wherein R is H or C 1 to C 8 alkyl, particularly C 2 H 5 or CH(CH 3 ) 2 , R' is H or C 1 to C 5 alkyl, particularly methyl, X represents a single bond or a --CH 2 -- linkage, and Y represents two hydrogen atoms, an additional bond or an epoxy group.
DETAILED DESCRIPTION OF THE INVENTION
According to one embodiment of the invention, the compounds of formulae (I), (III) and (IV) above are those of the formulae ##STR4## wherein R in formula (Ia) is H or lower alkyl of up to 8 carbon atoms, particularly C 2 H 5 or CH(CH 3 ) 2 .
By the expression "in the absence of an actively growing host plant" is meant either that the host plant is completely absent from the soil containing the parasitic weed seeds being treated, or that the host plant has substantially reached maturity so that any infestation of the host plant by the parasitic weed following germination of the seeds thereof will have a minimal effect on the host plant and harvesting of the latter or natural death at the end of the growing season will prevent the parasitic weed from reaching maturity and consequently re-seeding itself.
The invention also consists in herbicidal compositions comprising an active compound of the structure (I), (II), (III) or (IV), together with a suitable carrier. In addition, the invention consists in the new compounds of these structures, i.e. (I) [R is C 3 to C 8 alkyl and R' is H or C 1 to C 5 alkyl] (III) [wherein R' is C 1 to C 5 alkyl and X is a single bond, or wherein X is a --CH 2 -- linkage and R' is H or C 1 to C 5 alkyl] and (IV) [wherein R' is C 1 to C 5 alkyl, X is a single bond and Y is an additional bond or an epoxy group, or wherein R' is C 1 to C 5 alkyl, X is a --CH 2 -- linkage and Y is two hydrogen atoms, a single bond or an epoxy group].
A preferred aspect of the invention consists in compounds of formula (I) wherein R is CH(CH 3 ) 2 and R' is methyl; formula (III) wherein R' is CH 3 and X is a single bond; and formula (IV) wherein R' is methyl, X is a single bond and Y is an additional bond, and methods and compositions utilizing such compounds as well as the compound of formula (I) in which R is C 2 H 5 and R' is methyl.
The invention also consists in a process for the preparation of the compounds of formulae (III) and (IV) which comprises coupling an alkali metal salt, such as the sodium salt, of a compound of formula (II) with the methylsulphonate derivative of a compound of formula (I) wherein R is hydrogen. This synthesis has unexpected advantages over the subsequently proposed synthesis employing a bromo derivative of a compound of formula (I) wherein R is hydrogen, namely, it proceeds more readily, gives higher yields and is more economical, since the bromo derivatives are unstable and tend to re-arrange.
The active compound of formula (I), (II), (III) or (IV) is preferably applied to the soil containing the dormant parasitic weed seeds in the form of a composition containing the active compound in admixture with a suitable inert carrier or diluent. Suitable carriers or diluents are particularly finely divided solid inert carriers or diluents such as powdered chalk, powdered clays, or powdered conventional fertilizers. Also suitable are liquid carriers. Pre-mixes of a relatively high concentration of the active agent with a carrier may be formulated for ease of handling, particularly for ease of preparing the final composition to be applied to the soil. For instance, such a pre-mix may take the form of a solution of the active compound in an inert organic solvent, such solution also containing a surface active agent selected to promote the formation of an aqueous emulsion when the concentrate is diluted with a large volume of water.
The active compound of formula (I), (II), (III) or (IV) may be applied to the soil containing the parasitic weed seeds in amounts of from 100 to 5000 grams/hectare or from 0.01 to 0.5 grams/cubic meter of soil, and for this purpose compositions may be used containing from 0.001 to 1000 parts per million of the active compound, the balance of such compositions being essentially inert diluent or carrier as described above. The actual concentration of the active compound is of little importance compared with its rate of application to the soil. Too little of the active compound may secure insufficient germination of the parasitic weed seeds to afford effective control. Naturally, temperature and moisture conditions in the soil should be suitable for the germination of the parasitic weed seed.
While compounds of formula (I) wherein R is C 3 to C 8 alkyl, e.g. CH(CH 3 ) 2 have not previously been reported, they are homologues of the known compound (Ia) wherein R is C 2 H 5 and may be prepared by the usual esterification procedures from the known compound (Ia) wherein R is H, e.g. ##STR5##
As illustrative of the preparation of compounds (III) and (IV), compound (IIIa) for instance may be prepared by reacting an alkali metal salt, such as the sodium salt, of the known compound (II) with a sulphonate derivative of the lactone (Ia; R=H): ##STR6##
The compound (IVa) may be prepared by an analogous procedure, i.e. ##STR7##
Similarly, the compounds (III) and (IV) in X is a --CH 2 -- linkage and Y when present is two hydrogen atoms or a single bond, may be prepared analogously from 2-hydroxymethyl-δ-valerolactone sodium enolate salt or its cyclopentano or cyclopenteno derivative, while the compounds (IV) in which Y is epoxy may be prepared by epoxidation of the corresponding unsaturated compound.
The synthesis of some of the active compounds described above from readily available materials is illustrated by the following reaction schemes: ##STR8##
In order to demonstrate the activity of the compounds in promoting the germination of seeds of Striga hermonthica, Striga asiatica, Orobanche aegyptiaca, Orobanche crenata, and Orobanche ramosa, the following method was used. Seeds of the host plant (sorghum) and of the parasitic weeds were first sterilized with a 1% aqueous sodium hydrochlorite solution for 15 minutes, and then washed with distilled water until free of hypochlorite.
For the purposes of control experiments a natural root exudate of sorghum was prepared by planting sterilized sorghum seeds in pots containing acid-washed silver sand and incubating at 23° C with daily addition of sufficient distilled water to keep moist. After about 1 week the root exudate was extracted by applying suction to the base of the pots.
The Striga or Orobanche seeds were pre-treated by incubating at 23° C under moist conditions, e.g. on moist glass fibre filter paper, for 10-14 days. Usually about 25 seeds on 10 mm discs of the filter paper were employed.
Discs carrying pre-treated seed of Striga or Orobanche were dabbed to remove surplus moisture. Two discs were then placed in each of two replicate dishes, so there were 4 discs per treatment, carrying a total of about 100 seeds. The compounds to be tested were dissolved in ethanol and diluted to the required concentration with distilled water. The amount of ethanol was never greater than 0.5% v/v in the final solution. Freshly prepared solutions were always used. To each disc was added two 16 μl drops of test solution ("no exudate") or one drop of test solution plus one drop of crude root exudate from 10 day old sorghum plants ("+ exudate"). Dilution of the test solutions by the exudate and/or by moisture in the discs was allowed for so concentrations given were final concentrations. Germination was counted after 2 days at 34° C in the case of Striga and 5 days at 23° C in the case of Orobanche.
TABLE I______________________________________Germination tests on Striga hermonthica Concentration % GerminationCompound ppm "no exudate" "+ exudate"______________________________________ 0.001 1 0.01 27IIIa 0.1 51 ; 56* 1 61 10 70 50 -- 70 100 46Control(100% exudate) 72Control(distilled H.sub.2 O) 0______________________________________ *duplicate test carried out subsequently. The substances Ia [R = H; C.sub.2 H.sub.5 ; or CH(CH.sub.3).sub.2 ] and II showed little or no activity in promoting the germination of Striga hermonthica.
The substances Ia [R=H; C 2 H 5 ; or CH(CH 3 ) 2 ] and II showed little or no activity in promoting the germination of Striga hermonthica.
TABLE I______________________________________Germination tests on Striga hermonthica Concentration % GerminationCompound ppm "no exudate" "+ exudate"______________________________________ 0.001 1 0.01 27IIIa 0.1 51 ; 56* 1 61 10 70 50 -- 70 100 46Control(100% exudate) 72Control(distilled H.sub.2 O) 0______________________________________ *duplicate test carried out subsequently. The substances Ia [R = H; C.sub.2 H.sub.5 ; or CH(CH.sub.3).sub.2 ] and II showed little or no activity in promoting the germination of Striga hermonthica.
TABLE II______________________________________Germination tests on Orobanche aegyptiaca Concentration % Germination______________________________________Compound ppm "no exudate" "+ exudate"______________________________________ .001 0 .01 12 .1 19; 27; 44 1 59; 60 Ia(R = H) 10 80; 69 25 79 50 87 75 100 61; 68 200 8 30.sup.t 400 0Control(100% exudate) 84; 66; 78Control(distilled H.sub.2 O) 0; 20; 1 .001 0 .01 0 .1 19; 2 Ia(R = C.sub.2 H.sub.5) 1 34 10 58 25 95 50 88.sup.t 61 100 70; 83.sup.tIa(R-C.sub.2 H.sub.5) 200 19.sup.t 0 400 0 .1 4 1 6II 10 24 50 -- 66 100 64 .001 73 .01 76 .1 82; 77IIIa 1 69.sup. t 10 71.sup.t 50 -- 61.sup.t 100 47.sup.t 0.001 0 0.01 1 0.1 26.sup.t ; 11Ia[R = CH(CH.sub.3).sub.2 ] 1 26.sup.t 10 48.sup.t 50 72 100 67.sup.t______________________________________ t = Evidence of toxicity - some reduction in vigour
As in the case of tests on Striga, replicate tests were carried out on different dates.
It can be seen from Table II that each of the compounds has some activity in promoting the germination of Orobanche, the best being apparently Compound IIIa
TABLE III______________________________________Germination tests on Striga hermonthica, Striga asiaticaand Orobanche aegyptiaca.______________________________________Concentration % Germination______________________________________Compound ppm S.hermonthica S.asiatica O.aegyptiaca*______________________________________IIIa 0.007 3 56 87 0.00007 2 13 87 0.0000007 0 1 94IVa 0.007 22 60 87 0.00007 6 55 89 0.0000007 0 9 91ControlStandardexudate 65 59 89ControlDistilledwater 0 2 78______________________________________ *In this test the Orobanche seeds have little natural dormancy remaining. It is evident from Table III that compound IVa shows slightly higher activity against Striga than compound IIIa.
TABLE IV__________________________________________________________________________Germination tests on Striga hermonthia, Striga asiatica andOrobanche ramosa.__________________________________________________________________________ Concentration % Germination__________________________________________________________________________Compound ppm S.hermonthica S.asiatica O.ramosa__________________________________________________________________________IVa 1.0 -- -- 46 0.1 58 10 55 0.01 53 1 51 0.001 16 0 --IV X = single 1.0 45 30 bond Y = 2H 0.1 44 35 R' = CH.sub.3 0.01 21 41 0.001 4 --IV X = single 1.0 41 bond y = epoxy 0.1 18 group R' = CH.sub.3 0.01 3 0.001 0III X = CH.sub.2 1.0 -- linkage R' = CH.sub.3 0.1 17 3 0.01 5 5* 0.001 0 0Standard 58 5 --Sorghum exudate__________________________________________________________________________ *anomaly
TABLE V______________________________________Germination tests on Orobanche crenata ConcentrationCompound ppm % Germination______________________________________IIIa 1.0 52.0 0.1 18.0 0.01 0.0 0.001 0.0IVa 1.0 64.3 0.1 49.1 0.01 11.4 0.001 0.0Sorghum exudate 0.0Broad bean exudate 0.0Lentil exudate 0.0Distilled water 0.0______________________________________
For the following field tests the procedure was as follows: 1. Striga asiatica seed was uniformly mixed with black or red soil and the trays were filled on June 18, 1974.
2. Compounds IIIa and IVa were applied at 10, 5 and 1 ppm concentration in both the soils keeping 6 replications for each treatment and one control tray for each soil.
3. Watering was continued everyday up to field capacity.
4. C S H - 1 sorghum seed was planted in both treated and control trays on Aug. 19, 1974.
5. Counting of Striga plants above ground level was taken on Oct. 21, 1974.
6. Counting of Striga plants was also taken after washing the soil between Oct. 31, 1974 and Nov. 8, 1974.
The following results were presented. Values in the brackets indicate the number of plants before washing.
TABLE VI__________________________________________________________________________BLACK SOILCOMPOUND IIIa COMPOUND IVa__________________________________________________________________________Replica-tions10 ppm 5 ppm 1ppm 10 ppm 5 ppm 1 ppm__________________________________________________________________________1. 66 ( 64) 142 (127) 158 (140) 23 ( 18) 46 ( 22) 47 ( 40)2. 106 (104) 61 ( 59) 78 ( 74) 37 ( 25) 96 ( 77) 48 ( 47)3. 136 (133) 87 ( 84) 125 (112) 50 ( 35) 18 ( 13) 61 ( 43)4. 142 (123) 78 ( 67) 191 (150) 30 ( 24) 8 ( 8) 33 ( 30)5. 222 (167) 60 ( 58) 102 (100) 6 ( 4) 15 ( 11) 2 ( 1)6. 122 ( 95) 182 (159) 103 ( 83) 7 ( 6) 16 ( 9) 36 ( 21)Total806 (686) 610 (554) 757 (659) 153 (112) 199 (140) 227 (182)Mean 134 (114) 102 ( 92) 126 (110) 26 ( 19) 33 ( 23) 38 ( 30)Control126 (115) 90 ( 78)__________________________________________________________________________
Conclusions:
1. Statistical analysis of data indicated that compound IVa recorded the highest significant efficiency (50.00%) over control in controlling Striga.
2. There is no significant difference between concentrations in respect of both the compounds, possibly suggesting that some of the Striga seed was not sensitive to germination at the time the compound was applied.
TABLE VII______________________________________RED SOILCOMPOUND IIIa COMPOUND IVa______________________________________Replica-tions 10 ppm 5 ppm 1 ppm 10 ppm 5 ppm 1 ppm______________________________________1. 13 (1) 15 (2) 44 (7) 16 (5) 22 (6) 20 (7)2. 10 (2) 32 (4) 45 (7) 4 (0) 11 (3) 41 (7)3. 9 (1) 38 (6) 47 (8) 10 (0) 31 (6) 16 (3)4. 10 (3) 44 (3) 53 (5) 23 (4) 26 (5) 19 (4)5. 19 (5) 21 (2) 52 (8) 7 (2) 8 (3) 24 (3)6. 8 (3) 18 (3) 45 (6) 5 (0) 12 (2) 19 (3)Control -- 48 (6) -- 45 (7)______________________________________
Conclusions:
1. Statistical analysis of data indicated that the efficiency between compound IIIa and IVa in controlling Striga is significantly different.
2. Highly significant differences were obtained in between three concentrations in respect of both the compounds.
3. Compound IVa has recorded the highest efficiency (35%) at 10 ppm concentration in controlling Striga.
4. At 1 ppm concentration compound IVa has recorded 15.5% efficiency over control whereas compound IIIa has shown 0.5% efficiency. ##STR9##
SYNTHESIS OF COMPOUND IIIa
i. Preparation of the sodium salt of 3-hydroxymethylene-1,4-butyrolactone -- procedure of F. Korte and H. Machleidt, Ber., 88, 136 (1955).
Sodium (11.5g.) was suspended in dry ether (200 ml.) in a 1l. flask equipped with mechanical stirrer. Absolute ethanol (2 ml.) was added and the mixture stirred at room temperture for 3 hrs. A mixture of 1,4-butyrolactone (43g.) and ethyl formate (55.5g., 1.5 equiv.) in ether (100 ml.) was then added over a period of 1 hr. at room temperature. A precipitate was formed immediately and after the addition had been completed no more metallic sodium was present. The mixture was allowed to stand at -20° C overnight. It was filtered under vacuum and washed quickly with dry ether, then transferred while still wet with ether to a vacuum oven. The salt was dried at 40° C in vacuo. Yield, 64.5g. (95%).
ii. Preparation of Compound IIIa
The mesylate of compound Ia (19.04g.) was dissolved in 1,2-dimethoxyethane (200 ml.) and the sodium salt of 3-hydroxymethylene-1,4-butyrolactone (15g.) was added and this mixture stirred at room temperature for 24 hrs. The mixture was then filtered and the residue washed well with 1,2-dimethoxyethane. The filtrate was evaporated to dryness and the residue taken up in methylene chloride (20 ml.). Ether (60 ml.) was added carefully and the product allowed to crystallize. The white crystalline product was removed by filtration and washed with ether. Yield 12g. (60%), mp 92°-94° C. (Found: C, 57.04; H, 4.7 C 10 H 10 O 5 requires C, 57.14; H, 4.76%). ##STR10##
SYNTHESIS OF COMPOUND III (R' = CH 3 , X = --CH 2 --)
i. Preparation of the Sodium salt of δ-Valerolactone
Sodium metal (2.30g.) was suspended in dry ether (150 ml.) in a 500 ml. 3 neck round-bottom flask equipped with stirrer, heating mantle, dropping funnel and reflux condenser. Ethanol (1.5 ml.) was then added and the mixture stirred at room temperature for 3 hrs. The mixture was then heated to reflux and a mixture of δ-valerolactone (10g.) and ethyl formate (22.2g., 3 equivalents) in ether (50 ml.) added over a period of 1.5 hrs. The mixture was then stirred under reflux for 15 hrs., cooled and the sodium salt removed by vacuum filtration. It was washed well with dry ether and then dried in vacuo at 40° C. Yield 13g. (85.5%).
ii. Preparation of Compound III (R' = CH 3 , X = --CH 2 --)
The mesylate of compound Ia (1.26g.) was dissolved in 1,2-dimethoxyethane (20 ml.). The sodium salt of 3-hydroxymethylene-δ-valerolactone (1.5g., 1.5 equiv.) was added and the mixture stirred at room temperature for 4 hours. The mixture was then poured into icewater (100 ml.) and extracted with methylene chloride (2 × 100 ml.). The organic extracts were washed with water (2 × 50 ml.), combined, dried over magnesium sulphate, and evaporated to dryness. The semi-crystalline residue was taken up in methylene chloride (1.5 ml.), and ether (6 ml.) carefully added. The product crystallized and was removed by filtration and washed well with cold ether.
Yield 1.05g. (71%), mp 105°-107° C.
SYNTHESIS OF COMPOUND__________________________________________________________________________IVa ##STR11## ##STR12## Reaction (i) ##STR13## ##STR14## Reaction (ii) ##STR15## ##STR16## Reaction (iii) ##STR17## ##STR18## Reaction (iv) ##STR19## ##STR20## Reaction (v) ##STR21##__________________________________________________________________________
Reaction 1
To a 31. 3-neck flask equipped with mechanical stirrer and heating mantle, was added a solution of freshly prepared cyclopentadiene (156g.) and dichloroacetylchloride (117g.) in n-pentane (2000 ml.). The mixture was brought to reflux and triethylamine (86g.) in n-pentane (500 ml.) was added over a period of 0.5 hrs. The resulting heavy slurry was refluxed for a further 0.5 hrs. then filtered and the residue washed well with n-pentane. The filtrate was reduced in vacuo to 800 ml., transferred to a separating funnel and washed twice with water (2 × 200 ml.). The organic layer was dried over magnesium sulphate, the solvent removed in vacuo and the residue vacuum distilled, bp 72°-73° C at 3.5mm. Yield 108g. (77%).
Reaction 2
To a 21. 3-neck flask equipped with a mechanical stirrer was added a solution of the dichloroketone product of reaction 1 (100g.) in 90% acetic acid (aqueous) (900 ml.). Zinc dust (91g., 2.5 equiv.) was added portionwise to the cooled stirred solution over a period of 1 hr., the temperature beinng maintained below 40° C during this period. The cooling bath was replaced with a heating mantle and the mixture heated over 1 hr. to 100° C and maintained at that temperature. After 2 hrs. a further amount of zinc (91g., 2.5 equiv.) was added and the mixture stirred at 100° C for a further 1 hr. The mixture was then cooled to <10° C and filtered. The filtrate was poured into icewater (2000 ml.) and transferred to a separating funnel and extracted 3 times with methylene chloride (3 × 1000 ml.). The extracts were washed with water (4 × 1000 ml.), then with saturated sodium bicarbonate solution (1000 ml.). The combined extracts were dried with magnesium sulphate, the solvent removed in vacuo, and the residue vacuum distilled bp 61°-62° C at 14mm. Yield 51.4g. (86%).
Reaction 3
The ketone product of reaction 2 (40g.) was dissolved in acetic acid/H 2 O (7/1; 400 ml.). Hydrogen peroxide (30%) (94.6 ml., 2.5 equiv.) was added when the mixture had been cooled to 0° C. The mixture was then stored at 0° C for 18 hrs. then diluted with icewater (400 ml.) and extracted twice with methylene chloride (2 × 200 ml.). The organic extracts were washed with water (3 × 200 ml.) and with saturated sodium bicarbonate solution (200 ml.). The combined extracts were dried with magnesium sulphate, the solvent removed in vacuo and the residue vacuum distilled, bp 66°-67° at 0.3 mm. Yield 41.4g. (90%).
Reaction 4
A 250 ml. 3 neck flask equipped with magnetic stirrer, dropping funnel and nitrogen inlet was charged with dry diethyl ether (100 ml.). Sodium (2.83g.) and ethanol (1 ml.) was added to this mixture and stirred at room temperature for 3 hrs. The dropping funnel was then charged with a mixture of the lactone product of reaction 3 (15g.) and ethyl formate (10.2g.) in ether (50 ml.). This mixture was added dropwise to the sodium/sodium ethoxide slurry over a period of 1 hr. at room temperature. The mixture was then stirred for a further 1 hr. and then cooled to -20° C for 16 hrs. The sodium salt was removed by vacuum filtration and washed quickly with dry ether. The hygroscopic sodium salt, still very wet with ether, was rapidly transferred to a vacuum oven and dried at 40° C in vacuo. Yield 19.3g. (90%).
Reaction 5
The mesylate (19.4g.; see below) was dissolved in 1,2 dimethoxyethane (200 ml.) and cooled to 0° C. The sodium salt product from reaction 4 (18.5g.; 1.1 equiv.) was added and the mixture stirred at 0° C for 3 hrs. The precipitated sodium mesylate was removed by filtration and washed well with dimethoxyethane. The filtrate was evaporated to dryness at <40° C and the residue taken up in methylene chloride (200 ml.). The solution was washed with water (2 × 100 ml.), dried with magnesium sulphate and evaporated to dryness. Crude yield 24.6g. (98%). After crystallization from methylene chloride/ether the yield was 16.2g. (65%) mp 128- 130° C. Analysis: C 13 H 12 0 5 requires C, 62.90; H, 4.84. Found: C, 62.96; H, 4.68%.
Preparation of Mesylate.
A 21. 3 neck flask equipped with cooling bath and mechanical stirrer was charged with the pseudo acid (compound Ia; R = H) (80g.), mesyl chloride (81.15g., 1:01 equiv.) and methylene chloride (800 ml.). This mixture was cooled to 0° C and triethylamine (74.4g.; 102.4 ml., 1.05 equiv.) in methylene chloride (300 ml.) was added over a period of 41/2 hrs. The mixture was then stirred at 0° C for 8 hrs., and then poured into water (500 ml.) in a separating funnel. The organic layer was washed once more with water (250 ml.), dried over magnesium sulphate, and the solvent removed in vacuo. The residue was taken up in warm ether (100 ml.) and allowed to crystallize first at room temperture and then at -20° C. The product was removed by vacuum filtration and washed sparingly with ether. Yield 92g. (70%). | Active compounds, some of which are new, are described for the control of various parasitic weeds of the genus Striga and Orobanche. These compounds all include cyclic lactone structures and are related to the naturally occurring substance strigol. Methods of synthesis of the compounds are given, as well as compositions and methods for controlling the parasitic weeds. | 2 |
BACKGROUND OF THE INVENTION
The invention relates to an apparatus for applying surface pressure to advancing workpieces, such as wooden boards, boards made of wood materials or the like, the apparatus including at least one rotating pressing belt which can be pressed by means of a pressure medium against the workpiece in a pressure chamber disposed on the inside of the pressing belt and equipped with a seal.
In connection with such apparatus, it has been known to provide, above or below a workpiece passing on the upper side or on the underside, a single pressure chamber which covers approximately the entire width of the advancing workpiece. Such large pressure chambers, which are charged by a pressure medium such as compressed air, have various drawbacks. The sealing strips oriented in the direction of the pressing belt at the open side of such a pressure chamber are under considerably greater stress in the advancing direction of the workpiece than the seals oriented transversely to the direction of advancement of the workpiece. This leads to differences in abrasion and premature wear and also to losses of air. Due to the great length of the sealing strips, such a seal cannot be made of one piece. There exist one or a plurality of junctures which also lead to leaks or pressure losses. Great forces originating from the pressure medium act on the sealing strip so that they must be supported which is possible only at considerable structural expense. If there is a sudden great loss of pressure, the workpiece presses the pressing belt against the inner surfaces of the pressure chambers. This produces considerable water unless these inner surfaces are coated with a special antifriction material. The measures, taken merely to realize emergency running properties, are complicated and difficult to accomplish.
SUMMARY OF THE INVENTION
It is an object of the invention to improve the general apparatus in such a manner that the seals are formed without junctures or grooves and without the need for expensive supports and that they have good emergency running properties. The sealing strips should be easily exchanged. Moreover, the pressure chamber should be easily adaptable to workpieces having different widths.
Additionally, the advancing workpiece itself should directly control the pressure medium flowing into the many outer pressure chambers and thus control the movement of the many internal fittings which from time to time contact the pressing belt, on the one hand, independently of one another and, on the other hand, independently of the desired shape (width, length) as well as the passage rate of the individual workpieces.
This is accomplished according to the present invention in an apparatus of the above species in that a plurality of smaller pressure chambers are arranged over the width of the effective pressure surface of the pressing belt, the basic shape of such pressure chambers being that of round bodies having a circular base face.
With a plurality of such small pressure chambers, the sealing problem can be solved to particular advantage. Pressure chambers which have a basically circular shape, i.e. constitute cylindrical sections, can be produced very advantageously. The circular sealing strips can be manufactured of one piece, i.e. without joints. Due to its advantageous configuration, the seal is well supported at all sides and premature wear is avoided. Since the annular faces are relatively small, they can be worked with great precision. Difficulties due to processing inaccuracies as they occurred with prior art seals are eliminated. Small sealing strips can also be exchanged with ease. By simple juxtaposition of additional, smaller pressure chambers, the total effective pressure surface area on the pressing belt can be broadened or extended depending on the desired size of the pressing surface. The same components can always be resorted to. It is further possible to combine the small pressure chambers in rows which are situated next to one another in the direction of advancement of the pressing belt and are each charged separately (in rows) with a pressure medium. Thus it is possible with simple means to produce different pressures over the width of the pressure surface (pressing area) and to produce a different effective useful width of the pressing surface.
In a preferred embodiment there is provided a blocking device between the two pressure chambers for temporarily interrupting the pressure medium supply from the inner pressure chamber to the outer pressure chamber.
Such a blocking device makes it possible that when a workpiece arrives and thus the pressing belt is raised over a corresponding surface together with one or a plurality of inner fittings of individual pressure chambers the associated blocking device opens and pressure medium flows not only steadily into the inner pressure chamber but additionally also temporarily into the outer pressure chamber so that in the area of this outer pressure chamber the pressing belt is also pressed against the workpiece by the pressure medium. Such a control of each individual outer pressure chamber lying in the region of the surface of the passing workpiece has an immediate effect (i.e. without delay) and can cover all pressure chambers.
Once the workpiece has passed through, this blocking device, together with the movement of the inner fitting in the direction toward the pressing belt, blocks the supply of pressure medium to the outer pressure chamber so that the latter is essentially without pressure and no pressure medium can disadvantageously escape to the sides.
It does not matter in this connection what type of outline the passing workpiece has and whether a plurality of smaller workpieces with different outlines pass through simultaneously. The pressure chambers lying in the area of the surfaces of these workpieces are continuously charged with or relieved of pressure medium, as described above, so that the pressing belt is pressed on only in the region of the advancing surface of the workpiece or workpieces. Pressure losses are substantially avoided by such a direct and locally defined control.
In this embodiment according to the invention, the charge on the outer pressure chamber changes corresponding to the respective (temporarily) effective width of the pressure surface (corresponding to the width of the passing workpiece).
In a preferred embodiment, this blocking device is given the shape of an O sealing ring which is disposed between the annular chamber provided between the inner variable position fitting and the stationary holding member, and a step in the holding member.
In a modified embodiment according to the invention, the holding member is provided with further transverse bores so that the stationary holding member controls the flow of pressure medium, in the manner of a control piston, in dependence on the variable position of the inner fitting of each pressure device.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and are not intended to be restrictive of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a bottom view of a plurality of cylindrical pressure chambers disposed at a pressure plate in accordance with the present invention;
FIG. 2 is a vertical partial sectional view along line II--II of FIG. 1;
FIG. 3 is an enlarged view of the pressure chamber shown in partial section in FIG. 2;
FIG. 4 is a partial sectional view of a pressure chamber of modified design;
FIG. 5 is a vertical partial sectional view of a modified, cylindrical pressure chamber;
FIG. 6 is a vertical partial sectional view of the same pressure chamber with a blocking device according to FIG. 5 in the relaxed position;
FIG. 7 is a vertical partial sectional view of the same pressure chamber with the blocking device in the charged position;
FIG. 8 is a vertical partial sectional view of the same pressure chamber with a further modified blocking device in the relaxed position;
FIG. 9 is a vertical partial sectional view of the same pressure chamber with the blocking device in the charged position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus according to the invention comprises a lower frame and an upper frame, each accommodating endless pressing belts 10. These pressing belts are tensioned over guide rollers and can be driven thereby. They are arranged to leave a gap between them of a width which corresponds to the width of the workpiece to be processed. While the pressing belts 10 perform a horizontal movement with their surfaces contacting the workpiece, the workpiece is pulled into the gap between these surfaces and is there charged with pressure by the surfaces of the pressing belts 10. During passage of the workpiece through this device, the former is thus worked so that it leaves the gap between the pressing belts 10 at the exit as a finished workpiece.
In this way, foils which are unwound from supply reels can be pressed onto the upper and underside of the workpiece. Such a pressing process can take place at room temperature, or the application of high temperatures to the workpiece in the processing region may be provided at the same time. The desired pressure may be applied as air pressure acting in the pressure chambers which are disposed at the rear side of the pressing belt 10 with respect to the workpiece, i.e. at the surface of the pressing belt 10 which is not in contact with the workpiece.
The pressure chambers are disposed at a common pressure plate 11. Referring to FIGS. 3 and 4, for example each pressure chamber is formed by an inner fitting 14 or 15, respectively. The outer fitting 12 or 13 is held at the pressure plate 11 by means of a screw member 16 or 17, respectively, which is screwed into a threaded bore 18 or 19 in the pressure plate 11. Each pressure chamber is divided by the inner fitting 14 or 15, respectively, into an inner pressure chamber 20 or 21 and an outer pressure chamber 22 or 23.
The outer fitting 12 or 13 and the inner fitting 14 or 15 are arranged to be concentric with one another. An annular seal 24 or 25 held by the inner fitting 14 or 15 rests on the pressing belt 10. According to FIGS. 3, 6, 7 and 9 of the drawing, the seal 24 is inserted into a recess in the inner fitting 14. According to FIG. 4 of the drawing, the seal 25 is fastened to a guide ring 26 which concentrically surrounds the inner fitting 15. The guide ring 26 is supported at a flange 27 formed at the inner fitting 15. An elastic sealing ring 28 or 29, respectively, bridges the space between the inner fitting 14 (FIG. 3) or between the guide ring 26 (FIG. 4) and the outer fitting 12 or 13 surrounding it. In FIG. 3 the inner fitting 14 with the seal 24 is thus able to move slightly without friction with respect to the outer fitting 12. In FIG. 4 the guide ring 26 with its seal 25 is also able to move slightly, without friction, with respect to the outer fitting 13.
According to FIGS. 3, 6 and 7, of the drawing, an annular chamber 30 which connects the inner pressure chamber 20 with the outer pressure chamber 22 is provided between the screw member 16 having a stepped head 16a and the inner fitting 14. According to FIG. 4 of the drawing, an annular chamber 31 and slot 44 are provided between the inner fitting 15 and the guide ring 26 so as to connect together the inner pressure chamber 21 and the outer pressure chamber 23. Referring to FIGS. 2 and 5, compressed air can flow through channels 32 and 33 to the threaded bores 18 or 19 shown for example in FIGS. 3 and 4, respectively, in the pressure plate 11 and from there through a central blind bore 34 in the screw member 16 or through a central blind bore 35 in the screw member 17 through radial bores 36 of the screw member 16 or through radial bores 37 of the screw member 17 into the inner pressure chamber 20 or 21, respectively. From there, the compressed air can flow, via the annular chamber 20 or 21, respectively, into the outer pressure chamber 22 or 23, respectively, and there presses the pressing belt 10 against the workpiece.
According to FIGS. 3, 7, 8 and 9 of the drawing, the pressure in the inner pressure chamber 20 builds up in advance of the pressure in outer pressure chamber 22 and causes the inner fitting 14 together with the seal 24 to be pressed against the pressing belt 10. The pressing force depends on the pressure and on the surface of the inner fitting 14 which is charged with pressure inside the pressure chamber 20 and which is parallel to the pressing belt 10. This force is counteracted by a force depending on the pressure in the outer pressure chamber 22 and the surface of the inner fitting 14 charged by this pressure. The pressure in the outer pressure chamber 22 causes the pressing belt 10 to be pressed against the workpiece.
If, during operation, compressed air escapes from the outer pressure chamber 22 through a gap between the seal 24 and the pressing belt 10, such compressed air can be replenished with a certain choke effect from the inner pressure chamber 20 through the annular chamber 30. The air pressure in the outer pressure chamber 22 is then somewhat less than the pressure in the inner pressure chamber 20. If, now an undesirable escape of compressed air out of the outer pressure chamber 22 occurs during operation, the choke effect of the annular chamber 30 causes an increase in the pressure difference between the inner pressure chamber 20 and the outer pressure chamber 22 so that the force resulting from the pressure forces of the inner pressure chamber 20 and of the outer pressure chamber 22 pressing the inner fitting 14 with its seal 24 perpendicularly onto the pressing belt 10 becomes greater.
Correspondingly, in FIG. 4 of the drawing, the pressure in the inner pressure chamber 21 causes the guide ring 26 together with the seal 25 to be pressed against the pressing belt 10. The contact pressure depends on the pressure and on the frontal face of the guide ring 26 parallel to the pressing belt 10 inside the inner pressure chamber 21. This force is counteracted by a force which depends on the pressure in the outer pressure chamber 23 and on the frontal face of the guide ring 26 charged with this pressure within the outer pressure chamber 23. The pressure in the outer pressure chamber 23 causes the pressing belt 10 to be pressed against the workpiece.
If, during operation, compressed air escapes out of the outer pressure chamber 23 through a gap between the seal 25 and the pressing belt 10, the compressed air from the inner pressure chamber 21 can flow through the annular chamber 31 with a certain choke effect. The air pressure-in the outer pressure chamber 23 is then somewhat less than the pressure in the inner pressure chamber 21. If thus during operation there occurs an undesirable escape of compressed air from the outer pressure chamber 23, the pressure difference between the inner pressure chamber 21 and the outer pressure chamber 23 increases due to the choke effect of the annular chamber 31 so that the force resulting from the pressure forces of these chambers, which presses the guide ring 26 and the seal 25 perpendicularly onto the pressing belt 10, becomes greater.
In order to make the force with which the inner fitting 14 or the guide ring 26, respectively, is pressed toward the pressing belt greater than the force with which this fitting or this guide ring, respectively, is pressed away from the pressing belt 10, a helical compression spring 38 or 39, respectively, is inserted into the inner pressure chamber 20 or 21, respectively, the one end of this spring being supported at the outer fitting 12 or 13 and the other end at the inner fitting 14 or at the guide ring 26. According to FIGS. 3, 6, and 8 of the drawing, this helical compression spring 38 is given a conical shape while the helical compression spring 39 according to FIG. 4 of the drawing is cylindrical.
Since, however, the choke effect performed by the annular chamber 30 is often insufficient and pressure medium escapes undesirably, an additional blocking device in the form of an O-shaped, preferably elastic sealing ring 40 is inserted, according to the invention, between the stepped head 16a and the pressing belt side face 14a of the inner fitting 14 (see FIGS. 6 and 7). This sealing ring locks the annular chamber 30 when the pressing belt side face 14a approaches the stepped head 16a so that the pressure effect from the inner pressure chamber 20 on the inner fitting 14 is increased.
Such a simple blocking device permits the supply of pressure medium from the inner chamber 20 into the outer chamber 22 to be controlled directly by means of the passing workpiece and particularly its outer contours.
If a workpiece enters, its edges press against the pressing belt 10 and raise it over a surface area which corresponds to the surface of the passing workpiece. Thus all inner fittings 14 of the small pressure devices (pressure chambers) lying in the region of the edges and of the surface of the passing workpiece are raised so that the distance between the pressing belt side face 14a and the stepped, fixed head 16a is increased and thus the annular chamber 30 between the inner and outer chambers 20, 22 opens (FIG. 7). This causes the pressure medium which now flows into the outer pressure chamber 22 to press the pressing belt 10 against the passing workpiece. After passage, the rear edges of the workpiece release the inner fitting 14 so that the latter is lowered and the annular chamber 30 is again closed by the sealing ring 40. The outer pressure chamber 22 becomes free of pressure and thus also the pressing belt 10 which is not pressed into the free area (without workpiece). Then, pressure medium can also not escape in a disadvantageous manner (FIG. 6).
In a modified embodiment shown in FIGS. 8 and 9, the holding member (screw member) 16 is provided, in addition to the bores 36 for supplying pressure medium into the inner pressure chamber 20, with further bores 41 which open and close depending on the height setting of the inner fitting 14 whose position is directly controlled by the passing workpiece.
If a workpiece enters, its edge causes the inner fitting 14 (FIG. 9) to be raised and to release the lower bores 41, so that pressure medium can also flow into the outer pressure chamber 22 and there, as in the embodiment according to FIG. 7, it presses the pressing belt against the advancing workpiece. With the passage of the rear edge of the workpiece, the inner fitting 14 moves down and thus closes the bores 41 (FIG. 8). To do this, the inner fitting 14 may enclose the holding member 16 in a snug fit. If a small gap between the outer wall of the holding member 16 and the inner fitting 14 cannot be eliminated in practice, it is advisable and preferable to insert a sealing ring 42 into this gap in order to thus prevent inadvertent influx of pressure medium from the inner chamber 20 into the outer chamber 22.
A further advantage of the invention is found in the design of the screw member 16, 17 whose bores 34, 35 are designed as blind bores from which the radial bores 36, 37 open into the inner pressure chamber 20, 21. This causes compressed air to intially build up in the inner pressure chamber 20, 21 and move the inner fitting 14, 15 with seal 24, 25 onto the pressing belt 10 to seal the outer pressure chamber 22, 23. Only after passing the annular chamber 30, 31, will compressed air build up, with a delay, in the already sealed outer pressure chamber 22, 23. | In an apparatus for applying surface pressure onto advancing workpieces including at least one rotating pressing belt whose interior is acted on by a pressure plate, a plurality of smaller pressure chambers are arranged over the width of the effective pressure area of the pressing belt. Each one of these pressure chambers is divided into an inner pressure chamber and an outer pressure chamber so that the compressed air first builds up in the inner pressure chamber and then, with a delay, in the outer pressure chamber. Moreover, the inner fitting may be provided with a blocking device which temporarily blocks the supply of pressure medium to the outer pressure chamber. | 1 |
CROSS-REFERENCE
This is a division of Ser. No. 042,431, filed May 25, 1979.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to tools for testing earth formations in boreholes and more particularly for making formation pressure measurements, acquiring information concerning formation permeability and productivity, and retrieving samples of formation fluids.
2. Description of the Prior Art
Formation testing tools of the prior art of which I am aware have a number of deficiencies. It is important that such tools should have an effective failsafe arrangement to assure that the parts that are extended into contact with the formation when the tool is set can be retracted in the event of power failure, so that the tool can be removed from the borehole. The fail-safe arrangements of the prior art that I know of are actuated by a tensioning of the tool suspension cable to shear a pin or the like, and are subject to problems such as unintentional shearing of the pin, or inability to exert the requisite tensioning force due to cable key seating.
Formation testing tools conventionally provide a pre-test chamber or chambers into which a small quantity of formation fluid (typically about 20 c.c.) can be drawn in order to make formation shut in pressure measurements and obtain indications of formation permeability and potential production. Once the pre-test procedure has been initiated, the entire pre-test chamber capacity must be filled with formation fluid before shut in pressure can be determined, which in the case of low permeability formations can consume considerable time. In addition, the lack of control between the initiation and completion of the pre-test procedure precludes desirable flexibility.
Formation testing tools are typically quite long, and a considerable portion of their length is in the sample chamber portion, which is conventionally rigidly attached below the seal pad. While the tool is set, or when attempting to free the tool, this sample chamber portion can be jammed against the wall of the borehole and become differentially stuck.
Formation testing tools of the prior art that I know of have had problems in maintaining isolation of the formation at the seal pad when testing in unconsolidated formations.
Patents that exemplify prior art formation testing tools are U.S. Pat. Nos. 3,811,321, 3,813,936, 3,858,445, 3,859,850, 3,859,851, 3,864,970, 3,924,468, and 3,952,588.
SUMMARY OF THE INVENTION
A first objective of the present invention is to provide an improved failsafe arrangement to ensure the retracting of the seal pad means and backup pad means in the event of equipment malfunction. This is accomplished by providing electrically powered means controllable at aboveground equipment for generating and applying hydraulic setting pressure to extend and set the seal pad means and backup pad means; means for generating signals to be transmitted to above ground equipment, which signals are a measure of the hydraulic setting pressure, and power supply means for the signal generating means; and means operable in response to a failure of the power supply means to effect release of the hydraulic setting pressure and permit retraction of the seal pad means and backup pad means. In one aspect of the invention, the electrically powered means comprises a reversible electric motor coupled to driving means for moving a piston longitudinally of a cylinder which contains hydraulic fluid, and fluid passage means communicating between the cylinder and the seal pad means and backup pad means; and an electromagnetic clutch interposed in the driving means and operable in response to a failure of the power supply means to disengage the driving means. In a further aspect of the invention, the driving means comprises first and second gear reductions and a ball screw and ball nut, with the piston moveable with the ball nut; the electromagnetic clutch is interposed between the first and second gear reductions and has an energizing coil; the energizing coil being connected in series with the power supply means for the signal generating means; and spring bias means within the cylinder and exerting a force on the piston sufficient to overcome the frictional forces present in the ball screw and ball nut and second gear reduction when the electromagnetic clutch is de-energized, such that the piston is moved in the direction to increase the hydraulic fluid volume within the cylinder, thereby effecting release of the hydraulic setting pressure and permitting retraction of the seal pad means and backup pad means.
Another objective of the invention is to provide improved apparatus for achieving formation "shut-in" pressure measurements and for obtaining indications of formation permeability and potential production, and for obtaining formation fluid samples. The improved apparatus provides a formation fluid mini-sample chamber having variable volume, and fluid passage means for communicating between the mini-sample chamber and the formation at the seal pad location; electrically powered means controllable at aboveground equipment to vary at the will of an operator the volume of the mini-sample chamber; means for generating signals to be transmitted to aboveground equipment, which signals are a measure of fluid pressure within the mini-sample chamber; and means for generating further signals to be transmitted to aboveground equipment, which further signals are a measure of the volume of the mini-sample chamber. In accordance with a further aspect of the invention, the electrically powered means comprises a reversible electric motor coupled through a gear reduction to a ball screw and ball nut; with the variable volume mini-sample chamber comprising a cylinder having a sealed upper end and being moveable with the ball nut; a floating piston is disposed within the cylinder and is pressure biased so as to normally close fluid passage means communicating between the formation at the seal pad location and a formation sample chamber; and means are provided to move the floating piston upwardly to open the last mentioned fluid passage means upon a predetermined upward movement of the cylinder.
Another objective of the invention is to provide structure to alleviate the problem of sticking the tool in the borehole. The tool is made up of upper and lower elongated tool body sections and a pivot structure is provided connecting the lower end portion of the upper body section to the upper end portion of the lower body section for limited pivoting movement, with the axis of the pivoting movement being normal to the direction of movement of the seal pad means for extension and retraction. In another aspect of the invention, this pivot structure incorporates a seal valve for the formation sample chamber which is located in the lower tool body section. In accordance with another aspect of the invention, the seal valve comprises a body portion having a cylindrical exterior surface which acts as the pivot pin or journal for the pivot structure. In a further aspect of the invention, the valve body portion has cylindrical interior portions which carry respective first and second pistons disposed at opposite ends of a piston rod; formation fluid passage means communicates between the formation at the seal pad location and the formation sample chamber via the cylindrical interior portion, with the first piston interposed in the passage and movable to open or close the passage; hydraulic fluid passage means communicates between the means for generating and applying setting pressure to the seal pad means and the second piston; and spring bias means is provided to urge the first piston in the direction to close the formation fluid passage. In accordance with a still further aspect of the invention there is provided a third piston reciprocable within a cylinder which on one side of the third piston is open to the exterior of the tool and which on the other side is open to the valve body cylindrical interior portion which carries the first piston, such that force exerted on the third piston in the direction of closing the seal valve is mechanically transmitted to the first piston, while force exerted on the third piston in the direction of opening the seal valve is independent of the first piston.
Another objective of the invention is to provide improved means for maintaining isolation of the formation at the seal pad location when testing in unconsolidated formations. This improved means comprises formation isolation means including hydraulically controlled extendable and retractable seal pad means and backup pad means; the extendable and retractable seal pad means comprising a seal pad, first piston means having a central bore and fixed to the seal pad, and first cylinder means sealingly engaged by said first piston means; closure means sealingly closing the outer end of the first cylinder means and having a central cylindrical bore; a sand screen assembly comprising an elongated piston shaft, sand screen spring means, and piston shaft return bias means; the elongated piston shaft having a first end portion sealingly engaging the closure means central cylindrical bore and movable longitudinally thereof and a first end face, with the first end face being exposed to the well bore annulus when the tool is in operation; the seal pad means having a central opening communicating between the central bore of the first piston means and the earth formation to be tested when the seal pad is set in a well bore; the elongated piston shaft having a second end portion mating with the seal pad central opening and moving longitudinally thereof, and a second end face, with the second end face abutting the earth formation to be tested when the seal pad is set in a well bore; the sand screen spring means comprising a spirally wound spring having numerous turns that are normally separated sufficiently to permit flow of formation fluids as well as sand therethrough, with the inner diameter of the spring loosely mating with the exterior surface of the elongated piston shaft, and means fixing the spring at its outer end portion to the seal pad, with the free portion of the spring extending inwardly along the piston shaft; passage means communicating between the piston shaft second end face and its exterior surface along the length of the spring and beyond the inner end of the spring; abutment means fixed to said piston shaft adjacent the inner end of said passage means, for engaging the spring upon predetermined movement of the piston shaft outwardly toward the earth formation; such that the passage means can become limited to the spaces between the turns of the spring, which spaces are limited to the diameters of sand particles trapped therebetween. In a further aspect of the invention, the passage means are flutes in the exterior surface of the piston shaft. In a further aspect of the invention, the abutment means is a collar fixed to the piston shaft at the inner end of the flutes and mating with or integral with the exterior surface of the piston shaft.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing the tool of the present invention suspended in a borehole, with above ground equipment shown as a block.
FIG. 2 is a schematic showing of information that may be produced by a strip chart recorder during operation of the tool.
FIGS. 3-7 are schematic longitudinal section views which, when joined end to end consecutively, show from top to bottom the makeup of a tool in accordance with a preferred embodiment of the invention.
FIG. 8 is a schematic longitudinal section view showing the sample chamber seal valve incorporated in a pivot joint in accordance with a preferred embodiment of the invention.
FIG. 9 is a schematic longitudinal section view showing a sand screen device in accordance with a preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 there is shown a tool 11 of the present invention suspended in a borehole at the location of a formation to be tested, with a seal pad 13 and backup pads 15 in the set condition. The tool 11 is made up of two primary sections which may be termed the upper tool section 17 and the lower tool section 19. As will be hereinafter more fully explained, the lower section 19 is pivotally connected to the upper section 17 so as to provide limited relative pivoting movement about an axis 21 which is normal to the direction of travel of the seal pad 13 and backup pads 15 when they are being extended or retracted. The cable 23 and winch means 25 by which the tool 11 is suspended and traversed along the borehole, as well as the aboveground equipment shown as a block 27, are conventional, and consequently, need not be described in detail herein.
FIGS. 3-7 show the entire tool 11 in a series of schematic longitudinal section views, with all parts shown as they would be as the tool 11 is being run into the borehole.
The body of the upper tool section 17 may be regarded as made up of several elements, which observing from top to bottom in FIGS. 3-6, are a head sub 29, upper pressure jacket 31, pressure jacket connector sub 33, lower pressure jacket 35, pad block sub 37, and pad block 39.
The head sub 29 is threaded at its upper end portion for connection to a conventional cable head (not shown) and is threaded at its lower end portion for connection to the upper end of the upper pressure jacket 31. Suitable conventional cable connectors 41 are provided to make the electrical connections from the cable head through the head sub 29 to the interior of the upper pressure jacket 31. Since the manner of making the necessary electrical connections in the tool is a matter of conventional practice, the details of such connections are not shown or described herein. The lower end of the upper pressure jacket 31 is threadedly connected to the upper end of the pressure jacket connector sub 33. The upper end of the lower pressure jacket 35 mates in sliding engagement with the exterior surface of the pressure jacket connector sub 33 and is secured thereto by bolts. The lower end of the lower pressure jacket 35 is threadedly connected to the upper end of the pad block sub 37 and the upper end of the pad block 39 is fixed to the lower end of the pad block sub 37 by threaded compression connector means. O-rings 105 are provided at suitable locations at the connections of the body elements of the upper tool section 17 to seal out well bore fluids.
Apparatus for generating and controlling hydraulic pressure to extend and set seal pad means and backup pad means and to release same, may be referred to as the hydraulic power assembly. The hydraulic power assembly is contained within the portion of the upper tool section 17 shown by FIGS. 3 and 4, and comprises an electric motor 43, a first gear reduction 45, an electromagnetic clutch 47, a second gear reduction 49, a ball screw and ball nut assembly 51, and a hydraulic piston and cylinder assembly 53.
The hydraulic power assembly is supported within the upper pressure jacket 31 by the pressure jacket connector sub 33. A primary cylinder 55 of the hydraulic piston and cylinder assembly 53 is threadedly connected at its lower end to the upper end of the pressure jacket connector sub 33 and is threadedly connected at its upper end to the lower end of a bearing assembly retainer structure 57, which in turn is threadedly connected at its upper end to the lower end of a first cylindrical frame structure 59, which is fixed by bolts at its upper flanged end to the lower flanged end of a second cylindrical frame structure 61, which has an upper flanged end. The electric motor 43 (sometimes referred to herein as the setting motor) and its associated first gear reduction 45 are mounted on and fixed by bolts to the upper flanged end of the second cylindrical frame structure 61, with the first gear reduction 45 protruding into the interior of the second cylindrical frame structure 61.
The electric motor 43 drivingly engages the first gear reduction 45 which is connected by coupling means 63 to one side of the electromagnetic clutch 47, the other side of which is connected by coupling means 65 to one side of the second gear reduction 49, which in turn is connected on its other side by coupling means 67 to the upper end of a bearing hub 69 of the ball screw and ball nut assembly 51.
The electric motor 43 is a reversible 110 volt direct current motor which may typically be of the type manufactured by Globe Industries, Inc., of Dayton, Ohio, model number M1OOM13. Typically, the first gear reduction 45 may be 14:1 and the second bear reduction 49 may be 55:1. The electromagnetic clutch 47 may typically be of a type manufactured by Magtrol, Inc., of Buffalo, N.Y., model number FC1090313.
The hydraulic piston and cylinder assembly 53 comprises the primary cylinder 55, a secondary cylinder 71, a setting piston 73 and a setting piston return spring 75. The secondary cylinder 71 is disposed within a central bore 77 of the pressure jacket connector sub 33; is fixed therein by a retainer 79 which threadedly engages the lower end of the central bore 77; and protrudes downwardly beyond the retainer 79. The setting piston 73 has a head 81 which sealingly mates with the interior surface 83 of the primary cylinder 55, and an integral tubular extension 85 which protrudes into said secondary cylinder 71 and sealingly engages the interior surface 87 of the secondary cylinder 71 adjacent to entrance thereto. The setting piston 73 has a central bore 89 which extends throughout its length.
The ball screw and ball nut assembly 51 comprises the bearing assembly retainer structure 57, the bearing hub 69, a ball screw 91 and a ball nut 93. The bearing hub 69 is secured by suitable means for rotation within the bearing assembly retainer structure 57 and has a threaded upper extension portion 95 upon which there is mounted an actuator nut 97 which carries a limit switch actuator 99. The travel of the actuator nut 97 is related to the travel of the setting piston 73 so as to limit the latter in both upward and downward directions by actuating a respective limit switch 101, 103 to open the circuit to the setting motor 43. The ball screw 91 is fixed at its upper end to the lower end of the bearing hub 69 and extends downwardly the full length of the primary cylinder 55 and protrudes partially into the setting piston central bore 89. The ball nut 93 engages the ball screw 91 and is threadedly fixed at its lower end to the head 81 of the setting piston 73. The setting piston return spring 75 bears at its upper end against the bearing assembly retainer structure 57 which closes the upper end of the primary cylinder 55, and bears at its lower end on the head 81 of the setting piston 73.
Apparatus for conducting various formation tests and for providing and controlling flow valve means may be referred to for convenience as the mini-sample apparatus. The mini-sample apparatus is contained within the portion of the upper tool section shown by FIGS. 5 and 6, and comprises an electric motor 107, a gear reduction 109, a ball screw and ball nut assembly 111, and a mini-sample cylinder and piston assembly 113.
The mini-sample apparatus is supported within the lower pressure jacket 35 by the pad block sub 37. A third cylindrical support structure 115 is threadedly connected at its lower end to the upper end portion of the pad block 39 and is threadedly connected at its upper end to the lower end of a fourth cylindrical support structure 117. The electric motor 107 (sometimes referred to herein as the mini-sample motor) and its associated gear reduction 109 are mounted on and fixed by bolts to the upper end of the fourth cylindrical support structure 117, with the gear reduction 109 protruding into the interior of the fourth cylindrical support structure 117.
The electric motor 107 drivingly engages the gear reduction 109 which is connected by coupling means 119 to the upper end of a bearing hub 121 of the ball screw and nut assembly 111.
The mini-sample electric motor 107 may be of the same type as the setting motor 43. Typically, the mini-sample motor gear reduction 109 may be 445:1.
The mini-sample piston and cylinder assembly 113 comprises a primary piston structure 123, a primary cylinder 125, a floating piston 127, and a flow line valve body 129. The primary piston structure 123 comprises a piston head portion 131 and a cylindrical housing portion 133 having first and second central bores 135, 137. The piston head portion 131 is threadedly connected to the lower end of the cylindrical housing portion 133 which is also the lower end of the first central bore 135. The piston head portion 131 is reciprocable within the primary cylinder 125 formed by a central bore in the lower end of the pad block sub 37. The upper end of the first central bore 135 is sealingly closed by a pressure sensor adapter 139. The second central bore 137 has a threaded connection at its upper end to the ball nut 141 of the ball screw and ball nut assembly 111, and the second central bore 137 receives the ball screw 143 of the ball nut and screw assembly 111 as the ball nut 141 is moved upwardly.
The flow line valve body 129 is a generally cylindrical structure having a flanged upper end portion merging with an exterior threaded portion which in turn merges with cylindrical exterior sealing surfaces. The flow line valve body has a central bore 145, an annular exterior groove 147 disposed between said sealing surfaces, and flow passages communicating between the annular groove 147 and the central bore 145. The pad block 39 is provided a bore 149 for threadedly receiving said flow line valve body 129 and matingly receiving said sealing surfaces.
The floating piston 127 has a head portion 151 in sealing engagement with and reciprocable within the first central bore 135 of the primary piston structure 123 and an integral downwardly extending tubular extension 153 having an exterior sealing surface 155 at its lower end portion which is matingly received by the flow line valve body central bore 145. The upper surface of the floating piston head portion 131, the lower surface of the pressure sensor adapter 139 and the portion of the primary piston structure first central bore 135 between these surfaces formed a mini-sample chamber 159 having variable volume, as will be hereinafter explained. The floating piston 127 has a fluid passage 161 communicating between the mini-sample chamber 159 and the lower end of the pad block bore 149.
The ball screw and ball nut assembly 111 comprises a bearing assembly retainer structure 157, the bearing hub 121, the ball screw 143, and the ball nut 141. The bearing hub 121 is secured by suitable means for rotation within the bearing assembly retainer structure 157. The ball screw 143 is fixed at its upper end to the lower end of the bearing hub 121 and extends downwardly through the ball nut 141.
A limit switch actuator 163 is mounted on the primary piston structure 123 and is movable with the ball nut 141 between upper and lower limit switches 165, 170. The limit switches 165, 170 are connected in the power supply circuit of the mini-sample motor 107 so as to stop the motor when actuated. Thus, the travel of the ball nut 141 (and hence the primary piston structure 123) is limited.
A series of longitudinally extending cam notches 169 are provided on the exterior surface of the upper end portion of the primary piston structure for coaction with the cam actuator 171 of a microswitch 173 which is mounted to the third cylindrical support structure 115. The microswitch 173 produces an output pulse each time the cam actuator 171 traverses a cam notch 169. Each cam notch 169 represents an increment of mini-chamber 159 volume (typically 2 c.c.).
The tool 11 has an electronics section 175 comprising various components mounted on a chassis 177 located in a space between the upper end of the mini-sample motor 107 and the lower end of the secondary cylinder 71 of the hydraulic piston and cylinder assembly 53. The electronics section chassis 177 is secured at its upper end to the lower end portion of the secondary cylinder 71.
A hydraulic fluid or seal pad setting pressure sensor 179 is mounted in the end of the secondary cylinder 71. A formation fluid pressure sensor 181 is mounted in the pressure sensor adapter 139 of the mini-sample apparatus.
Power (110 volts direct current) is supplied from the aboveground equipment via cable 23 and connectors 41 separately to each of the setting motor 43 and the mini-sample motor 107 in series with respective limit switches 101, 103 and 163, 165, so that each motor 43, 107 can be separately controlled by the aboveground operator. Power (26 volts direct current) is also supplied from the aboveground equipment to the electronics section 175, in series with the energizing coil of the electromagnetic clutch 47, so that the electromagnetic clutch 47 is de-energized to disengage when and if there is a failure in the 26 volt direct current power supply. The electronics section 175 includes a power supply and amplifiers for the pressure sensors 179, 181 and also a power supply and amplifier for the circuit of microswitch 173. Output signals from each pressure sensor amplifier and the microswitch circuit amplifier are transmitted to the aboveground equipment via the cable 23. Since the electronics section, the power supply conductors and various electrical connections are matters within the scope of conventional practice, these are not shown or described in detail herein.
An inner cylindrical jacket 183 is received within the lower pressure jacket 35 and is matingly and sealingly received at its upper end by a cylindrical external surface portion 185 of the pressure jacket connector sub 33 and is further matingly and sealingly received at its lower end by an exterior cylindrical surface 187 at the upper end of the pad block sub 37.
The pad block 39 carries a sealing pad assembly 189, upper and lower backup pad assemblies 191, 193 and an equalizer valve assembly 195.
The sealing pad assembly 189 comprises a sealing pad 197, sealing pad retainer 199, sealing pad plate 201, upper and lower sealing pad guide rods 203, 205, sealing pad piston 207, sealing pad piston plug 209, and sealing pad cylinder 211. The sealing pad 197 is made of a resilient material such as rubber, which typically may be 60-90 durometer nitrile rubber, and has a generally rectangular shape, with some curvature in transverse section so as to generally conform to the borehole wall curvature. The sealing pad plate 201 is a metal plate that can cover a large portion of the inner surface of the sealing pad 197. The upper and lower sealing pad guide rods 203, 205 are secured by bolts to the sealing pad plate 201 adjacent its respective upper and lower edges and are reciprocable in respective mating bores (not shown) in the pad block 39. The sealing pad retainer 199 is generally cylindrical having a flanged outer end, a cylindrical exterior portion 200 matingly received by a sealing pad central bore, and an exterior threaded portion at its inner end which engages internal threads at the outer end of the sealing pad piston 207. When the sealing pad retainer 199 is in place, the sealing pad 197 is clamped between the retainer flanged outer end and the sealing pad plate, and the sealing pad plate is clamped between the sealing pad inner surface and the outer end face of the sealing pad piston 207. Thus, the sealing pad 197 and sealing pad plate 201 are securely fixed relative to the sealing pad piston 207.
The sealing pad retainer 199 has a cylindrical bore 202 at its inner end portion which merges with a threaded intermediate bore 204 of smaller diameter which in turn merges with an outer end bore of still smaller diameter, for a purpose to be hereinafter explained. The sealing pad piston 207 has a first exterior cylindrical surface 206 that extends over about half its length from the center portion outwardly toward the sealing pad 197 and a second cylindrical exterior surface 208 of smaller diameter extending from the center portion inwardly to the inner end. The sealing pad piston 207 has a cylindrical central bore 210 extending between the internal threads 222 at the outer end portion and internal threads 224 at the inner end portion, which cylindrical central bore 210 merges with and has the same diameter as the cylindrical bore 202 at the inner end of the sealing pad retainer 199.
The pad block 39 has a central transverse bore 213 having a first cylindrical portion 212 matingly and sealingly receiving the first exterior cylindrical surface of the sealing pad piston 207 and merging with a second cylindrical portion 214 of increased diameter for providing a fluid flow passage to and around the sealing pad piston 207, and merging with a third cylindrical portion 216 of further increased diameter for receiving a cylindrical exterior portion of the sealing pad cylinder 211, and merging with a fourth cylindrical portion 218 of further increased diameter for matingly and sealingly receiving a second cylindrical exterior portion of the sealing pad piston 207, and merging with a fifth cylindrical threaded portion 220 of further increased diameter for receiving a threaded exterior portion of the sealing pad cylinder 211.
The sealing pad piston plug 209 has a cylindrical exterior portion 215 that matingly and sealingly engages a first cylindrical interior surface 217 of the sealing pad cylinder 211 and merges with a threaded cylindrical portion 219 of reduced diameter which engages the threads 224 at the inner end portion of the sealing pad piston 207. The threaded cylindrical portion 219 has a plurality of longitudinally extending grooves 221 which extend to communicate with corresponding lateral bores 223 to provide fluid passages between the second exterior cylindrical surface 208 of the sealing pad piston 207 and its interior. The sealing pad cylinder 211 has a second interior cylindrical surface 225 of lesser diameter than the first cylindrical interior surface 217 and which matingly and sealingly engages the second exterior cylindrical surface 208 of the sealing pad piston 211. A shoulder 227 on the exterior surface of the sealing pad piston at the juncture of the first and second exterior cylindrical surfaces 206, 208 of the sealing pad piston 211 abuts the inner end surface of the sealing pad cylinder 211 to provide a stop for the sealing pad piston 211 in the retracting direction.
The upper backup pad assembly 191 comprises a piston shaft 229, a backup pad 231, a seal plug 233, and a guard pad 235. A transverse bore 237 in the pad block 39 receives the piston shaft 229 and seal plug 233. The backup pad 231 is made of metal; is generally disc shaped; and is fixed to the outer end of the piston shaft 229. The seal plug 233 is fixed to the pad block 39 at the entrance to the transverse bore 237 by threads 239 and has a circumferential groove 241 in its exterior surface to provide a fluid passage. The piston shaft 229 matingly and sealingly engages a first interior cylindrical portion 243 of the seal plug 233 located at the seal plug outer end portion; which interior cylindrical portion 243 merges with a second interior cylindrical portion 245 of greater diameter, which second interior cylindrical portion 245 in turn merges with an interior cylindrical portion 247 of the transverse bore 237. The guard pad 235 is sealingly fixed to the pad block exterior surface by bolts and serves to protect the sealing pad 197. The guard pad 235 has a central cavity 249 which receives the inner end portion of the piston shaft 229.
The lower backup pad assembly 193 is like the upper backup pad assembly 191 except that its seal plug 251 does not incorporate circumferential groove 241 and consequently does not provide the associated fluid passage.
The equalizer valve assembly 195 comprises a piston 253, a seal ring 255, a retainer plug 257 and a bias spring 259. The pad block 39 is provided a bore 261 for receiving the equalizer valve assembly 195. The piston 253 matingly and sealingly engages adjacent its inner end a portion 263 of the pad block bore 261 and adjacent its outer end a central bore 265 of the seal ring 255. The inner end of the piston is exposed to a hydraulic fluid flow passage, while the outer end is exposed to well bore fluid. The retainer plug 257 threadedly engages the outer end portion of the pad block bore 261 to hold the seal ring 255 in place within a portion of the pad block bore 261. The bias spring 259 bears at one end on the seal ring 255 and at the other end on a shoulder on the piston 253, so as to urge the piston inwardly for a purpose to be hereinafter explained.
The lower tool section 19, with the exception of the pivot assembly 277, is of a conventional design and consequently will be described only briefly herein. The body of the lower tool section 19 may be regarded as made up of several elements, which, observing from top to bottom in FIG. 7, are a bleed off sub 267, a formation sample chamber 269, a chamber connector sub 271, a cushion chamber 273, and a bull plug 275.
The bleed off sub 267 is threadedly connected at its lower end portion to the upper end portion of the formation sample chamber 269 which is threadedly connected at its lower end portion to the upper end portion of the chamber connector sub 271 which is threadedly connected at its lower end portion to the upper end portion of the cushion chamber 273 which is threadedly connected at its lower end portion to the bull plug 275.
The bleed off sub 267 has a transverse bore 279 which on one side carries a seal plug 281 and on the other side carries a bleed off valve 283. A formation sample fluid passage 285 in the bleed off sub communicates from the pivot assembly 277 via the bleed off valve 283 to the volume of the sample chamber interior above a sample chamber piston 287. The sample chamber volume below the sample chamber piston 287 contains water which is forced via a choke assembly 289 carried by the chamber connector sub 271 into the volume of the cushion chamber 273 above a cushion chamber piston 291, as the sample chamber piston 287 is moved downwardly. The cushion chamber volume below the cushion chamber piston 291 contains air. A separate fluid passage 293 communicates between the lower end of the formation sample chamber 269 and the upper end of the cushion chamber 273 via the chamber connector sub 271 and a check valve 295. Suitable seals are provided within the lower tool section by various O-rings 297.
As hereinbefore stated, the lower tool section 19 is pivotally connected to the upper tool section 17 so as to provide limited relative pivoting movement about an axis 21 which is normal to the direction of travel of the seal pad 13 and backup pads 15 when they are being extended or retracted. The pivot assembly 277 (see FIG. 8) comprises first and second upper tool section pivot bearing protrusions 299, 301, a lower tool section pivot bearing protrusion 303, and a formation sample chamber seal valve assembly 305 which comprises a seal valve body 307, a piston rod 309 having first and second pistons 311, 313 carried on its opposite ends, a bias spring 331, a third piston 315, and a retainer cylinder 317.
The first and second upper tool section pivot bearing protrusions 299, 301 are integral with and extend downwardly from the lower end of the pad block 39 in parallel juxtaposed relation and have respective coaxial transverse bores 319, 321 of equal diameter. The lower tool section pivot bearing protrusion 303 is integral with and extends upwardly from the upper end of the bleed off sub 267 and into the slow 322 formed between the first and second protrusions 299. 301. The lower tool section pivot bearing protrusion 303 has a transverse bore 325 coaxial with and of the same diameter as the respective bores 319, 321 of the first and second protrusions 299, 301. These transverse bores form the bearing box or bearing surfaces for the pivot pin or journal of the pivot assembly 277, which in the embodiment shown, is the seal valve body 307.
The seal valve body 307 has a cylindrical exterior surface 327 that is sealingly and matingly received within the transverse bores 319, 321, 325. The transverse bore 321 of the second bearing protrusion 301 does not extend all of the way through the protrusion, and a chamber is formed at the inner end portion of the seal valve body 307 which communicates with a hydraulic fluid flow passage 329 in the pad block 39.
The retainer cylinder 317 threadedly and sealingly engages the outer portion of the transverse bore 319 and has a cylindrical interior portion 343 which matingly and sealingly engages the third piston 315. The seal valve body 307 has a first cylindrical interior surface 333 that matingly and sealingly receives the second piston 313 and a second cylindrical interior surface 335 of smaller diameter that matingly and sealingly receives the first piston 311. Fluid passage means 337 is provided at the inner end portion of the retainer cylinder to communicate with a formation fluid flow passage 339 in the pad block 39. Another fluid passage means 341 is provided in the seal valve body 307 to communicate between the valve body interior and a formation fluid flow passage 285 in the bleed off sub 267.
When the tool 11 is operated in a borehole where unconsolidated formations may be encountered, the sand screen assembly 345 shown by FIG. 9 is utilized. To install the sand screen assembly 345, the sealing pad piston plug 209 (see FIG. 6) is removed and the sand screen assembly 345 is inserted in the cavity made up of the cylindrical bore 202 of the sealing pad retainer 109, the cylindrical central bore 210 of the sealing pad piston 207 and the space vacated by the piston plug 209.
The sand screen assembly 345 comprises a sand screen plug 347, an elongated piston shaft 349, a sand screen spring 351 and a bias spring 353. The sand screen plug 347 is like the sealing pad piston plug 209 that it replaces, except that the sand screen plug 347 has a central bore 355 for matingly and sealingly receiving the outer portion of the piston shaft 349 for reciprocable movement therein. The outer end face of the piston shaft 349 is thus exposed to the well bore when the tool 11 is in operation. The inner end portion of the piston shaft 349 is received by the outer end bore of the sealing pad retainer 199, so that the outer end face of the piston shaft 349 can move into abutting relation with the earth formation being tested when the tool 11 is in operation. The bias spring 353 bears at one end on a shoulder formed at the juncture of the sealing pad retainer cylinder bore 202 and the threaded intermediate bore 204, and at the other end on a ring 357 which is held against outward movement by roll pins 359 carried by the piston shaft 349. When the bias spring 353 is relaxed, the piston shaft 349 is positioned such that its outer end is flush with the outer face of the sand screen plug 347. The sand screen spring 351 is a spirally wound spring having numerous turns that are normally separated sufficiently to permit flow of formation fluids as well as sand therethrough. The inner diameter of the sand screen spring 351 mates loosely with the exterior surface of the piston shaft 349 and the sand screen spring is secured at its inner end by threading onto the threaded intermediate bore 204 of the sealing pad retainer 199. The sand screen spring 351 typically may have fifty turns in about 11/2" of length when relaxed and shortens to about 11/8" when fully compressed. The piston shaft 349 is provided passage means (shown as spiral flutes 361) communicating between the outer end face of the piston shaft 349 and its exterior surface along the length of the sand screen spring 351 and a short distance (typically about 1/4") beyond the inner end of the sand screen spring 351. Abutment means, shown as a collar 363, is fixed to the piston shaft 349 adjacent the inner end of the passage means 361, for engaging the sand screen spring 351 upon predetermined movement of the piston shaft 349 outwardly toward the earth formation. Passage means 365 are provided between the outer end face of the piston shaft 349 and the spiral flutes 361. The inner and outer end faces of the piston shaft 349 have equal diameters, so that the piston shaft 349 will not move as the tool 11 is being traversed into the borehole, since well bore fluid pressures on the end faces of the piston 349 are balanced.
When the tool 11 has reached the test site and the sealing pad assembly 189 has been extended and set in sealing engagement with the formation and the volume of the mini-sample chamber 159 has been expanded, then the pressure force on the inner face of the piston shaft 349 will be less than that on the outer face, so that the piston shaft 349 will be continually urged into contact with the formation. Initially, the turns of the sand screen spring 351 will be separated and formation fluid including sand can pass through the turns of the sand screen spring 351 and also through the space between the outer end of the sand screen spring 351 and the inner end of the collar 363. As the unconsolidated formation is eroded, the piston shaft 349 moves inwardly so that the inner end face of the collar 363 abuts the outer end of the sand screen spring 351 and compresses same. The sand screen spring 351 will not fully compress because of sand particles that become trapped between the spring turns. Thus, eventually, the only flow path from the formation via the piston shaft passage means 365 to the interior of the sealing pad piston 207 is between the compressed turns of the sand screen spring 351. Since no more sand can pass between the turns of the sand screen spring 351, the formation ceases to erode and only formation fluid is passed through the sand screen spring. When the formation test is completed and well bore fluid pressure again acts on the inner end of the piston shaft 349, the pressure forces on the ends of the piston shaft 349 will again be balanced, allowing the bias spring 353, which was compressed by movement of the piston shaft 349 inwardly, to move to its relaxed position, returning the piston shaft 349 to its original position. As the piston shaft 349 returns toward its original or initial position, the turns of the sand screen spring 351 are wiped by the spiral flutes 361 to clean off the sand particles.
It will be convenient to describe the operation of the tool 11 with reference to FIG. 2 which schematically presents certain information that is produced by a strip chart recorder and is observed by the operator at the above-ground equipment location during operation of the tool.
In FIG. 2, the trace A represents hydraulic pressure sensed by hydraulic fluid pressure sensor 179 on a scale of 0-5,000 p.s.i. The trace B represents the pulses produced each time the cam actuator 171 traverses a cam notch 169. In the embodiment shown, each pulse represents a two c.c. volume increment of mini-chamber 159 volume. The digital printout column C shows in p.s.i., at predetermined time intervals (typically 5 seconds), the pressure sensed by formation fluid pressure sensor 181. Trace D represents the pressure sensed by the formation fluid or hydrostatic pressure sensor 181 on a scale of 0-10,000 p.s.i.; while trace E represents the pressure sensed by the formation fluid pressure sensor 181 on a scale from 0-1,000 p.s.i.
As the tool 11 is run into the borehole, all parts are in the positions shown by FIGS. 3-7. When the tool 11 is stopped at the depth of the earth formation to be tested, the operator energizes the setting motor 43 for rotation in the direction to cause ball nut 93 to move upwardly, bringing with it the setting piston 73. As the setting piston 73 moves upwardly, hydraulic fluid is forced out of the primary cylinder 55 and via various fluid passage means to the interior of the sealing pad piston 207 and the interiors of the upper and lower backup pad assemblies 191 193, thus causing the sealing pad 197 and the backup pads 231 to be extended into contact with the wall of the well bore. This hydraulic fluid flow path can be traced from the interior of the primary cylinder 55 through the ball nut 93, through the setting piston central bore 89 to the interior of the secondary cylinder 71 and via a passage 367 to the space between the lower pressure jacket 35 and the inner cylinder jacket 183 to a hydraulic fluid pressure passage 369 in pad block sub 37 and through a connector valve assembly 371 to a hydraulic fluid passage 373 in pad block 39. This hydraulic fluid flow path is isolated by means of various o-ring seals. When the hydraulic fluid pressure reaches a value which is about 1,500 p.s.i. above the well bore pressure, then the sealing pad 197 is considered to be set, thus isolating the formation at the sealing pad location. In FIG. 2 it can be seen that this event occurs at the point 375 of trace A and at a readout of about 1,623 pounds on trace C. When the point 375 is observed by the operator, he de-energizes setting motor 43.
Next, the operator energizes the mini-sample motor 107 for rotation in the direction to cause ball nut 141, and consequently primary piston structure 123, to move upwardly. Upward movement of the primary piston structure 123 causes the volume of mini-sample chamber 159 to begin to increase. The min-sample chamber communicates with the formation being tested at the seal pad location via passage means which can be traced from the mini-sample chamber 159 through the floating piston fluid passage 161 to the circumferential groove 241 in seal plug 233, through a passage in the pad block 39 to the pad block bore 261 for the equalizer valve assembly 195 and through a further passage in pad block 39 to the third cylindrical portion 216 of the pad block central transverse bore 213 and through openings in the wall of sealing pad cylinder 211 and through bores 223 and sealing pad piston plug 209 and the grooves 221 in threaded cylinder portion 219 of sealing pad piston plug 209 to the interior of the sealing pad piston 207 which is exposed to the earth formation at the sealing pad location. This formation fluid path is isolated by means of various o-ring seals, so long as the equalizer valve 195 is closed.
The pressure forces acting on the upper end of the floating piston 127 are always greater than those acting on its lower end because of unequal surface areas, and consequently the floating piston is always urged downwardly by the differential pressure forces. Thus, the floating piston 127 remains in its extreme downward position as the primary piston structure 123 is moved upwardly. In the example shown by FIG. 2, the operator permits the primary piston structure 123 to move upwardly until five pulses have been generated on trace B, showing that the mini-sample chamber volume 159 has increased to 10 c.c. Observing trace E of FIG. 2, it will be seen that the fluid pressure in the mini-sample chamber 159, as sensed by the formation fluid pressure sensor 181 rapidly decreases as the mini-sample chamber volume is increased. As seen by the pressure readout in column C, the mini-sample chamber pressure has decreased from 1,623 p.s.i. to 1,087 p.s.i. and soon thereafter increases and stabilizes at about 1,279 p.s.i. (see also trace E). This is the "shut-in" pressure of the formation being tested.
It will be observed that it was only necessary for the operator to open the mini-sample chamber sufficiently to cause the pressure therein to drop to a point considered to be below the likely formation shut-in pressure and then de-energize the mini-sample motor 107 and wait for the mini-sample chamber pressure to build up and stabilize, at which point the formation "shut-in" pressure will have been reached. When the formation being tested has a low permeability, only a small amount (perhaps only 2 c.c.) of formation fluid need be drawn into the mini-sample chamber to achieve formation "shut-in" pressure. If it were necessary to wait for a large test sample chamber to fill before formation "shut-in" pressure is achieved, this could take a long time in the case of low permeability formations. An important feature of the present invention is the provision for a variable volume mini-sample chamber which can be monitored at aboveground equipment and controlled at the will of an operator.
Next, the mini-sample motor 107 is again energized in the direction to continue upward movement of the ball nut 141 and consequently the primary piston structure 123, generating a second series of pulses on trace B of FIG. 2. After a predetermined upward movement of the primary piston structure 123, a shoulder on the upper end of piston head portion 131 engages a shoulder on the lower side of the head portion 151 of the floating piston 127, forcing the floating piston 127 to move upwardly away from seal means 377 to open a flow passage from the floating piston fluid passage 161 to the groove 147 in the flow line valve body 129 and through passage means including fluid flow passage 339 in the pad block 39 and via the seal valve 305 and a further formation fluid flow passage 285 in the bleed off sub 267 and through the bleed off valve 283 and further fluid flow passage 285 into the formation sample chamber 269.
It should be noted (see FIG. 8) that the sample chamber seal valve 305 is normally urged to its closed position under the force of bias spring 331 because the second and third pistons 313, 315 have the same diameter and are exposed to well bore pressure. The piston 313 is exposed to hydraulic fluid via the hydraulic fluid flow passage 329. The piston 313 is subjected to hydraulic fluid pressure generated by the action of the setting motor 43 and consequently the piston rod 309 and first piston 311 are moved outwardly to open the seal valve 305 thus permitting formation to flow from passage 339 to the interior of the seal valve body 307. The equalizer valve inner end face is also subjected to hydraulic fluid pressure generated by the action of the setting motor 43 and is moved to the closed position by such hydraulic fluid pressure.
The opening of the formation fluid flow line (upon sufficient upward movement of floating piston 127) results in a drastic pressure drop within the mini-sample chamber as sensed by the formation fluid pressure sensor 181. This event is observed by the operator at point 379 on trace A and also in the pressure readout column C where the pressure reading suddenly drops from 1,183 p.s.i. to 159 p.s.i. At this point, the operator stops the mini-sample motor 107 (or it is stopped by a limit switch) and waits for the formation sample chamber 269 to fill. As the formation sample chamber 269 is filled, the formation pressure readings (column C of FIG. 2) gradually increase until the formation "shut-in" pressure is again reached (when the column C readouts show about 1,272 p.s.i.). After the formation "shut-in" pressure has again been reached, indicating that the formation sample chamber 269 is full, the operator again energizes mini-sample chamber motor 107 to rotate in the reverse direction, thus moving the primary piston structure 123 downwardly, permitting the floating piston 127 to move downwardly to its lower most position, thus closing the formation fluid flow passage through the flow line valve body 129. Then, downward movement of the primary piston structure 123 is continued in order to expel the formation sample fluid from the mini-sample chamber 159. The operator, monitors the volume condition of the mini-sample chamber 159 by watching the series of pulses on trace B of FIG. 2.
Next, the operator energizes the setting motor 43 in the reverse direction to cause the setting piston 73 to move downwardly, increasing the volume of the primary cylinder 55 thus reducing the hydraulic fluid pressure. This hydraulic fluid pressure reduction permits the equalizer valve 195 to open, and the seal valve 305 to close. Thus, the formation sample chamber 269 is sealed. Also, well bore fluid is admitted to the interior of the sealing pad piston 207 and consequently onto the formation at the sealing pad location, which results in equalization of pressures on the sealing pad 197 causing it to release its contact with the formation. Differential pressures on the sealing pad assembly 189 and the upper and lower backup pad assemblies 191, 193 cause them to retract to their running in positions. The rapid reduction in hydraulic pressure resulting from the reversing of the setting motor 43 may be noted on trace A of FIG. 2 between the points 381 and 383. The operator can also notice from column C of FIG. 2 that the equalizer valve has opened when the pressure readout returns to normal well bore pressure (at about 1,495 p.s.i.).
It should be noted that the herein disclosed arrangement of mini-sample apparatus makes it possible to open and close the flow line path at the flow line valve body 129 and vary the volume of the mini-sample chamber 159 independently of any other function of the tool 11. This makes possible certain operator options. First, as hereinabove mentioned, the waiting time for achieving formation "shut-in" pressure can be greatly reduced. Second, the formation fluid flow line can be opened and re-closed during a sample test in order to unplug the flow path by injecting fluid in the mini-sample chamber 159 back through the system and into the formation at the seal pad location. Third, a formation "shut-in" pressure test can be performed at any time either while the formation fluid sample chamber 269 is being filled, or thereafter, by closing the formation flow line passage at the flow line valve body 129. Further, all of the functions above-mentioned can be performed independently of the sealing pad setting function. | A tool for testing earth formations in boreholes provides a failsafe function for retracting the sealing pad elements of a formation isolation device, in the form of elements operable in response to failure of downhole power supply for the tool to effect release of hydraulic setting pressure on the seal pad elements. The tool further provides a formation mini-sample chamber of variable volume with elements permitting aboveground monitoring and control of same independently of any other tool function. The mini-sample chamber control device also controls the operation of a formation fluid sample flow line valve. The tool is divided into upper and lower pivotable sections to alleviate the problem of becoming differentially stuck. A unique pivot structure incorporating sample chamber seal valve assembly, is provided. A unique sand screen device is provided to permit the tool to function when working with unconsolidated formations. | 4 |
CONTINUATION APPLICATION
The following application is a continuation of U.S. patent application Ser. No. 09/781,616, filed Feb. 12, 2001 now U.S. Pat. No. 7,493,391.
CROSS-REFERENCE TO RELATED PATENTS
The present invention is related to the following patents which are specifically incorporated herein by reference:
Pending patent application Ser. No. 09/409,345 filed Sep. 30, 1999 by Cessna et al. entitled “Framework for Dynamic Hierarchical Grouping and Calculation based on Multidimensional Characteristics” and assigned to the assignee of the present invention. This patent is sometimes referred to herein as the Framework Patent.
Pending patent application Ser. No. 09/491,834 filed Jan. 26, 2000 by C. Bialik et al. entitled “Method and System for Database Management for Supply Chain Management” and assigned to the assignee of the present invention. This patent is sometimes referred to herein as the Database Patent.
U.S. patent application Ser. No. 09/781,615 filed concurrently by the inventor of the present document, Iwao Hatanaka, and entitled “Method and System for Incorporating Legacy Applications into a Distributed Data Processing System” and assigned to the assignee of the present invention. This patent is sometimes called the Legacy Application Patent.
Issued U.S. Pat. No. 6,021,493 of Daryl C. Cromer et al. entitled “System and Method for Detecting When a Computer System is Removed from a Network” issued on Feb. 1, 2000 and assigned to the assignee of the present invention. This patent is sometimes referred to herein as the Heartbeat Patent and is useful in detecting whether a client is attached to a server.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is an improved system and method for automatically managing session resources in a distributed network of processors, such as a client-server environment, where the invention has the particular advantage of automatically releasing those resources allocated to a session when the session ends, whether through a normal ending or through an abnormal ending. More particularly, the present invention includes a session management framework which can be applied to release session resources when the session ends abnormally, e.g., through the halting of an application or the loss of a connection between the server and the client.
2. Background Art
In a client-server environment, a local terminal (sometimes referred to as a client) is connected to a server for the purpose of processing information in a distributed environment. Frequently, the client is itself a data processing system which communicates with a server which is generally a data processing system with increased resources, including applications and data which are not available at the client application. Such a system is described in some detail in the Framework Patent referenced above. In a client-server environment, resources may be centrally managed at the server as opposed to being disparately managed at each individual client. In some cases, the client does not have the capability of managing or maintaining large resources.
The client is frequently located at a distance from the server and communicates with the server using telecommunication facilities, including hardware and software operating over phone service such as might be provided using telephone lines, either alone or in combination with other communication systems such as satellite or microwave communications. A series of communications occur between a client and its server (for example, to execute an application on the server using data supplied by the client and report the results of the application back to the client) is sometimes referred to as a session, with a session including a plurality of communications between the server and the client. In any event, there are frequently several different links in the communications chain, and when one of the links fails to operate, the communications channel is disrupted and the session is terminated.
While the session was in existence, various resources at the server are dedicated or reserved for the use of the particular client which requests use of those resources. So, in a supply chain application, a variety of storage units associated with the server may be used by a client during a session and various applications and databases may be dedicated to the client and its session, often to the preclusion of using those same resources for other clients while a session with the one client is in progress. Such a preclusion is understandable, particularly when an application may be changing the application or the database, so access during a change by another application may provide the wrong execution or the wrong data.
A session with a client “ties up” resources generally (memory used for one application cannot be used at the same time for another application) and for some specific reasons (a client which is using a database typically marks the database so that another client cannot simultaneously use the database and change the information stored in the database while the other client is using the database, for example).
Since the resources are limited and other clients may want to use the same resources, it is advantageous to release the resources as soon as the resources are not needed, and the normal termination of a session (e.g., the completion of execution of a program) typically provides a release of the resources which have been used for the session as a part of the normal ending of the session.
But, when a session is abnormally terminated, it does not go through the normal ending or winding down process which releases the resources. In fact, many of the events which contribute to the abnormal termination of a session result from a total lack of communications with a client, perhaps because the connection between the client and the server is no longer functional. This is becoming more of a problem when the communication is over the public Internet or a virtual private networks, where a large number of users are connected through paths which are constantly changing as the network evolves, and the session depends on the continuing availability of a path between the client and the server.
The Legacy Application Patent describes an approach to allow use of legacy applications in a distributed processing environment, allowing legacy applications which were not designed to be utilized in a distributed processing system to be used in such a system. Such a system inherently requires that resources which are being used in a distributed data processing system be committed to the use and be released once the processing has ended.
Several approaches have been suggested for determining when a session is no longer active. One of these involves polling, or making sure that the client and the server remain active by periodically issuing an inquiry from the one to the other with an answer back if the connection is still in place. This involves setting up some kind of periodic inquiry system and keeping track of when an inquiry is due for each of the clients, an exercise which requires resources and does not necessarily provide a prompt notice that a client has been dropped by the network—that is, without a lot of repeated polling of each client every short interval, the server does not know which clients remain attached and which clients are no longer attached. But, polling requires continuing use of resource and suggests that polling ought to be done at lengthy intervals to reduce the use of network resources, but the longer the interval, the longer resources may be dedicated to serve a session which no longer exists.
A prior art system for determine whether a resource is attached sometimes uses a “heart beat” technique for determining whether the resource remains attached. But, in such a system a ping is sent out addressed to the remote user and the absence of a response is taken to mean that the resource is not attached, when, in fact, the ping or its response may have been misdirected or lost in the system without the resource actually being disconnected. Another disadvantage of polling is that message traffic is increased for each client which is added to the system. Also, there is the lack of an unequivocal indication that a resource is no longer needed or that a client is no longer connected.
Accordingly, the prior art systems have undesirable disadvantages and limitations.
SUMMARY OF THE INVENTION
The present invention overcomes the limitations and disadvantages of the prior art systems by providing a system and method for releasing resources dedicated to a session promptly, even when the session ends abnormally and without a termination message.
The present invention has the advantage that it is simple and easy to implement to allow for the release of resources held for a client when the client is no longer connected to the server.
The present invention allows for the prompt reallocation of resources from a client to an other client when the first client is no longer using the resource without polling or a periodic inquiry of the connected status of each of the clients using resources of a given server.
The present invention involves setting up a resource manager for each session and logging the use of resources associated with that session. Then, when the session is no longer active—for whatever reason, including normal disconnection or a lost connection, the resource manager consults the listing of resources associated with that session and releases the resources for use, allowing use with other sessions.
Using the resource manager for normal and abnormal session terminations means that it is not necessary to have two different types of session terminations, one for normal terminations and a different one for an abnormal termination.
The present system also allows for a table which identifies which resource is associated with which user.
The present application is suited for use in a system such as are described in the Legacy Application Patent. The use of a distributed data processing solution means that different processors may have reserved resources such as applications which need to be resolved when a session ends.
A system such as the Heartbeat Patent may be used to determine whether a client is attached to the server at any given time. By periodically querying the clients, it is possible to determine whether the client is still coupled to the server or if the connection has been lost for some reason. The Heartbeat Patent is one way (but certainly not the only way) to determine whether the client is still coupled to the server and capable of communicating. If the Heartbeat Patent detects that a given client is no longer attached, it can signal the server to allow release of the resources associated with the client.
Other objects and advantages of the present invention will be apparent to those skilled in the relevant art in view of the following description of the preferred embodiment, taken together with the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is an improved system and method for resource cleanup, an embodiment of which is illustrated with reference to the accompanying drawings in which:
FIG. 1 depicts a communications system representative of the preferred embodiment of the present invention;
FIG. 2 , consisting of FIG. 2A and FIG. 2B , are flow diagrams of the preferred embodiment of the present invention; and
FIG. 3 , consisting of FIG. 3A and FIG. 3B , are diagrams illustrating resource tables useful in practicing the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following description of the preferred embodiment, the best implementation of practicing the invention presently known to the inventors will be described with some particularity. However, this description is intended as a broad, general teaching of the concepts of the present invention in a specific embodiment but is not intended to be limiting the present invention to that as shown in this embodiment, especially since those skilled in the relevant art will recognize many variations and changes to the specific structure and operation shown and described with respect to these figures.
FIG. 1 illustrates a communications system of the type used in the present invention. In this FIG. 1 , a first client (CLIENT 1 ) 100 is connected to a first server (SERVER 1 ) 110 through a network 120 . Additional clients (CLIENT 2 , CLIENT 3 , CLIENT 4 ) 131 , 132 , 133 , respectively are shown also connected to the first server 110 through the network 120 and additional servers (SERVER 2 , SERVER 3 and SERVER 4 ) 141 , 142 , 143 , respectively are also shown connected to the network 120 . While this is a simplistic view of a network in which a plurality of servers are connected to serve a plurality of clients, it will allow discussion of the problems with such an arrangement and an understanding of the present invention and its advantages. The first client 100 may involve an application which uses a resource at the first server 110 (for example, an application APPLN 1 referred to by the reference numeral 111 ) and a resource at the second server 141 (for example, a database DB referred to by the reference numeral 151 ) and store the result in a file 152 maintained on the third server 142 (the file 152 might be a file with pro forma income and profit projections), all of which data processing is accomplished through the communications network 120 which connects the client 110 with the servers 110 , 141 and 142 . Meanwhile, the second client 131 may wish to use resources at the first server 110 , the second server 141 and a fourth server 143 . If the second client 131 is using different resources at the servers from the other clients at any given time, then there is no problem. If, however, the first client 100 is using the particular application APPLN 1 111 at the first server 110 , then the second client may not be permitted to use the application APPLN 1 111 at that same time, but would be permitted to use an application APPLN 2 112 which is also at the first server.
The present invention leverages the fact that each client session with a server is associated with a single file descriptor in the server during a client connection to the server. All communications from and to that client takes place through that file descriptor. Through a callback program associated with that file descriptor, client termination events can be captured to trigger desired system processing at precisely the time that the client disconnects from the server. This functionality allows for automatic session clean-up by detecting client termination and then freeing up corresponding resources being held on the server for the terminated client session.
FIG. 2 illustrates in flow diagram form the logic of the present invention showing aspects of the present invention. FIG. 2 consists of FIG. 2A and FIG. 2B . FIG. 2A shows logic for the determination of whether a resource is available and assigning the resource to a particular requesting client while FIG. 2B shows logic for determining whether to release a resource and the steps taken to release that resource and allow for further use of the resource by other clients.
FIG. 2A illustrates the process of a client using resources at a server as was described in connection with FIG. 1 . The process starts at block 202 and at block 204 a request is received by the server for resources associated with that server, resources which may be use of an application, access to a database stored on the server or simply to a block of memory, for example, as a temporary storage for an application. While the server may have a large number of resources and many of these resources are not unique (one block of empty memory may be similar to the next), others of the resources are unique (the server may have a single copy of an application or a database) and the resources are limited (the server might well run out of memory if the memory were not released and reused by a second client after the first has completed its processing). Based on the request received at the block 204 for resources, at block 206 the server determines whether the resource is available to the requesting client. Such availability is determined in connection with resource listings such as FIG. 3 , particularly FIG. 3B which identifies each resource as being available or being used by a named client. If the client is requesting use of a database already in use by another client or if the memory requested is not available, then the request is denied at block 208 with an appropriate message (‘resource in use; try again later” or “inadequate memory presently available; try elsewhere or try again later”). If, on the other hand, the resource is available for the client, then at block 210 , access is granted and the resource is logged (see FIG. 3 and the associated text for a discussion of the logging process to include identification of which resources are available and which are used by which clients) as assigned to the requesting client. In any event, following the disposition of a request for resources, either by granting it at block 210 or denying it at block 208 , control returns to the starting area where the next request can be processed by the block 204 .
FIG. 2B illustrates the process for releasing a resource which has been assigned to a client and for which the client no longer has a need for the resource. Such a release may be because the program using the resource has run its course and terminated successfully or because something unnatural has occurred, like the client has become disconnected from the server—i.e., either the server 110 or the client 100 is no longer connected to the network 120 or the client 100 is no longer operational. While a normal termination of an application program may issue the explicit command to release the resources that the application has been using, the program may abort or otherwise not issue such a command.
The process of FIG. 2B is as follows: starting from block 220 , at block 222 the question is asked whether a client has specifically released a resource. If not, then at block 224 , it is determined whether the client remains attached to the network. This determination can be made through any of a number of conventional approaches, such as “pinging” the client or by determining a heartbeat of the client using the Heartbeat Patent referenced above. If the client is present, then control passes to an optional set of time determinations which serve to limit the time that a resource can be used—either with activity or without activity. Associated with the resource (e.g., an application, database or memory) and/or the client are allowable time intervals. For example, a client may use a first application for 30 minutes but will be considered inactive if no activity occurs within a 15 minute time period. Thus, at block 226 the amount of time a resource has been used will be compared with an allowable time for such use (if any has been set) by comparing the present time with the beginning time which was stored in column 308 of FIG. 3A to determine the amount of time the resource has been in use. If the time that the resource has been used does not exceed the limit, then the amount of inactive time is compared at block 228 . That is, the period since the last use (in column 310 of FIG. 3 ) to the present is compared with a threshold (if set) to determine whether the resource has been held without activity longer than a preset period of time. If the client released the resource (at block 222 ), the client is not attached (at block 224 ), the time of use (block 226 ) or the time of inactivity (block 228 ) exceed the set limits, then the resource is released at block 230 with the entry in the table of resources being used ( FIG. 3A ) erased at block 232 and the resource marked as available in the listing of FIG. 3B at block 234 . Control then returns to the start for the next resource action.
FIG. 3 shows resource tables useful in practicing the present invention. In FIG. 3A , a first table 300 depicts in list form the resources currently being used and the client using each of the resources. Although only a portion of this table 300 is shown to illustrate the principles of the present invention, the table could be as large as necessary to contain data about all the clients using the server and the resources that each of the clients is currently using. The table includes a first column 302 which lists the resource being used, a second column 304 listing the client using the resource, a third column 306 indicating the type of access (whether it is read only or read/write), a fourth column 308 indicating the time which the resource was first accessed and a fifth column 310 indicating the time that the resource was last used. Use of the fourth column 308 with the beginning time allows for a time limit to be set for release of the resource after a fixed amount of time and the fifth column 310 (last use) allows for a time limit to be set that releases a resource if it has not been used within a fixed period of time. That is, the resource could be released after x minutes of use (based on a comparison of the current time with the start time stored in column 308 ) or after y minutes of nonuse (based on a comparison of the current time with the time in column 310 ). The times allowed (x minutes of use, y minutes of nonuse) are subject to system constraints and may be adjusted based on the type of use and whether concurrent uses are permitted. In some situations, a read-only access of a resource may not preclude others' use of the same resource and one client might be permitted to continue to use such a resource on a non-exclusive basis than would be permitted if the resource were being used on an exclusive basis. An optional sixth column 312 provides the time of the last indication that the client is connected, a time which may be provided by receiving a request from the client or from a return “ping” of the client as discussed elsewhere.
In FIG. 3B , a listing of the resources is provided and an associated status for each resource—whether the resource is “free” for use by a client or if it is currently committed to a client and not available. This FIG. 3B lists each of the resources along with its status, by resource. So, FIG. 3B includes a left column 330 which lists the resource and a right column 332 which either lists the resource as being used by a named client or being available. This, for the simple example of FIG. 1 , APPLN 1 is shown in block 334 as a resource and in block 344 , it is being used by client 110 . APPLN 2 is listed in block 336 as a resource and in block 346 , it is being used by client 131 . APPLN 3 is listed in block 338 as being available in block 348 . Similarly blocks of memory and other resources such as the database DB can be assigned to a particular client, and at the end of the use by that client, release by removing the entry in the columns of FIG. 3 .
The present invention can be realized in hardware, software, or a combination of hardware and software. A data processing tool according to the present invention can be realized in a centralized fashion in one computer system, or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system—or other apparatus adapted for carrying out the methods described herein—is suited. A typical combination of hardware and software could be a general purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein. The present invention can also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which—when loaded in a computer system—is able to carry out these methods.
“Computer program means” or “computer program” in the present context mean any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following a) conversion to another language, code or notation; b) reproduction in a different material form.
While the present invention is described in the context of an apparatus and a method of providing resource management, the present invention may be implemented in the form of a service where collecting, maintaining and processing of information is located apart from the server and information is communicated as needed to the server.
Of course, many modifications of the present invention will be apparent to those skilled in the relevant art in view of the foregoing description of the preferred embodiment, taken together with the accompanying drawings. For example, the system for recognizing that the session between the client and the server no longer exists may be determined in any manner and is not limited to that disclosed in the foregoing material. Additionally, the location and type of information maintained about a session may be modified to suit the application and need not be the listing of resources associated with each client as disclosed. Such information may be stored in connection with each resource being used rather than in a central location, although there are advantages to having the information located centrally in that a central location makes it easier and quicker to release and reuse the resource again. Additionally, certain features of the present invention may be useful without the corresponding use of other features without departing from the spirit of the present invention. For example, a client may be using several resources associated with different applications and one application may end (so the resources associated with that application should be released) or the entire connection may terminate (so all applications terminate). Further, the system of FIG. 3B arranges data on resource use including the same data as FIG. 3A , and the two could be combined, if desired, using a single database to show what resources are in use and what clients are using the resource. Accordingly, the foregoing description of the preferred embodiment should be considered as merely illustrative of the principles of the present invention and not in limitation thereof. | Systems and methods for automatically managing session resources in a distributed network of processors are disclosed. In one embodiment of the invention, a system for managing the use of resources in a system where a remote client uses resources at a server for a limited duration includes: a stored listing of at least one resource being used at the server and the client using that resource; a system which identifies that a remote client is no longer using resources at the server; and in response to the system identifying that the client is no longer using resources at the server, a mechanism which removes the resources which had been used by the client when the client was connected to the server, whereby the resources being used by a client may be used by other clients after the client has disconnected from the server. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISK
Not Applicable
REFERENCE TO A MICROFICHE APPENDIX
Not Applicable
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention refers to open end spinning, or rotor spinning. Open-end spinning machines generally consist of a plurality of individual spinning units, aligned on the two sides of the machine, each of which is made up of a spinning rotor, which produces twisted tread from singularised fibres of a rove, and a collection unit that—with the prior quality control of yarn with the interposition of a yarn clearer between the two components—carries the yarn to wind onto a quill to form a cone. This cone is thus formed pulling and winding the yarn on its surface, being pulled into rotation by the roller below on which the cone in formation is rested. The yarn is wound in a spiral on the cone in rotation since the collection unit is equipped with a thread-guiding device that distributes the yarn on the outer surface of the cone with to and fro axial motion.
The structure of the individual spinning station is illustrated in the scheme of FIG. 1 , and its operation according to its normal running is briefly described hereafter.
Proceeding from the bottom towards the top, the spinning station 1 consists of the actual spinning unit 2 and the collection unit 3 , the main components of which that lead to the transformation of the rove of fibres made to run parallel in the cone of wound yarn are briefly illustrated hereafter.
The supply band or rove S is contained in a cylindrical vessel 4 where it is deposited in a double spiral. The rove S is supplied to the unit by a supply roller 5 passing through the funnel-shaped conveyor 6 and reaches the card 7 , a rotating roller equipped with a toothed trimming that singularises the fibres of the rove S and conveys them by suction to the spinning rotor 8 , which works in a vacuum.
In the spinning rotor 8 , which rotates at very high speeds (up to 150,000 revs/minute and beyond), the singularised fibres are deposited in its peripheral throat by centrifugal effect; from here they are collected and picked up in the form of thread F, coming out axially from its central opening 9 , receiving the twists from the rotation of the rotor itself in the path that runs between its inner throat and such an opening 9 , thus generating the twisted thread F.
The pulling back of the thread is carried out with a pair of opposite extraction cylinders 11 and 12 for gripping the thread F and actuated at a controlled speed according to the arrow a, thus determining the linear production of yarn, generally indicated in m/min. The yarn clearer 14 for controlling the quality of the yarn F can be placed before the cylinders 11 / 12 . The thread F thus produced enters into the collection unit 3 , passes by a sensor 15 of the presence of thread and meets a compensator 16 for compensating the variations in length of the path between the spinning unit 2 and the deposit point of the yarn F on the cone. The thread-guiding device 21 distributes the thread on the cone in formation moving transversally with to and fro motion according to the double arrow b, actuated by a motor 20 that commands a longitudinal shaft 22 in common with the other units of the spinning machine. The cone 25 collects the thread F and is held by the cone-holding arm 26 equipped with two idle tailstocks 27 that can be opened that go into engagement with the basic quill 28 of the cone. The cone in formation 25 is rested upon its actuation roller or collection cylinder 29 .
Recently conceived automatic open-end spinning machines are equipped with service trolleys that patrol the sides of the spinning machine and carry out the required interventions stopping in front of the spinning unit that requires it.
The required interventions are essentially of three types:
for starting, at the beginning of the spinning from a still spinning machine, starting it and then placing a new quill in each station, carrying out the start-up with an auxiliary thread and winding the thread produced on the new quill to give a cone, after having eliminated that portion of auxiliary thread; for reattachment, when the yarn is interrupted for whatever reason, without having yet reached the length foreseen for completing the cone, using the yarn already produced by the side of the cone, carrying out the reattachment and continuing the winding on the same cone. The reattachment procedure essentially consists of the opening, cleaning and closing of the rotor, the preparation of the tail of the rove, the capturing and preparation of the end at the side of the cone, the restarting of the rotor and the continuation of the supply, the re-introduction into the rotor of the prepared end, the re-extraction of the end connected to the newly produced thread winding it once again in the collection unit. The programmed cleaning cycle is the equivalent to the reattachment cycle, caused with a commanded breaking of the thread; for lifting, after having reached the foreseen length for the cone to be complete. The finished cone is discharged and then one proceeds to starting the unit as outlined above.
Generally, such interventions are carried out by separating the cone 25 from its actuation cylinder 29 , stopping its motion and actuating the cone 25 or its quill 28 by an auxiliary actuation roller arranged on-board the service trolley.
(2) Description of Related Art
In the field of devices and procedures for the intervention of service trolleys on automated open end spinning machines the applicant is the owner, amongst others, of patents IT 1.146.694, EP 340.863, EP 443.220, EP 473.212, IT 1.258.220, IT 1.258.221, IT 1.258.222.
In general, the automation trolley consists of a structure mobile along the sides of the machine, a communication system with the central control unit of the spinning machine and with the spinning unit that make up the machine, a translation and stopping system of the trolley in front of the units that require intervention. The mobile structure carries on-board members or groups of members dedicated to single or multiple operations of the various cycles that can at various times be required. Such members of the trolley are managed by the trolley's own control unit, which in turn communicates with the central control unit of the spinning machine and with the individual spinning stations.
In open-end spinning machines that are currently available the automation trolley, faced with a failed reattachment or lifting cycle, repeats the operating sequence of the cycle from the beginning for a certain number of times, in general not more than three so as not to compromise the overall efficiency of the spinning machine.
The spinning unit, after said failed attempts of the trolley, is left out of order (with a red light). The trolley is then advantageously diverted to be used for servicing other spinning units that require it.
On the trolley with a red light, the operator takes care of an inspection to identify the cause of the negative outcome of the previous automatic intervention and to take steps to prepare it for a further intervention, again to be conducted automatically, this time with a positive outcome.
In trolleys in use up to now on open-end spinning machines groups of members are arranged that are dedicated to single or multiple operations in the starting, reattachment, lifting and cleaning cycles of the spinning units.
In general such groups are—at least for the most part—mechanically interconnected, because they are equipped with cam actuation, and even if they are equipped with thread control and position sensors, they must necessarily operate in sequence. The various groups of members on-board the trolley carry out the various steps foreseen in sequence: they recover the end of the thread, they pass it from one to the next carrying out their job until the reattachment or the lifting is obtained on the spinning unit on which they intervene. At most, such automation trolleys allow—just for groups with autonomous actuation—their individual step to be lengthened or repeated until it has positively been completed.
It is clear that the failure of one of the steps of the cycle has the consequence of the failure of the entire cycle.
With the evolution of open-end spinning machine technology, the range of counts, of yarns and of fibres to be worked has substantially widened, whereas the quality specifications of yarn have become more stringent. With the overall cycles relative to reattachment and lifting in which a substantial number of members or groups of members on-board the trolley cooperate, its efficiency, in other words the successful completion of the operation without carrying out many attempts over and again, is very important. The coordination of said members is therefore very important for controlling them as regards relative positions, time and speed phasing of such members both in relation to each other and with respect to the thread that is adopted, manipulated and exchanged by said members, controlling the successful completion of each step of the process.
BRIEF SUMMARY OF THE INVENTION
The present invention is relative to a service trolley for open-end spinning machines, in which the individual operating steps in the cycles of the trolley are controlled one by one so that, in the case of failure of one of the steps, the trolley does not waste time pointlessly continuing with the sequence, but can restart the cycle from the unsuccessful step to repeat it, possibly with different operating parameters.
The purpose of the present invention is that of making a service trolley for open-end spinning machines that overcomes the described drawbacks of trolleys available in the state of the art and allows greater efficiency of the interventions and greater yield of the spinning machine to be obtained, reducing the idle time due to the repetition of interventions on spinning units.
In the trolley according to the invention the steps of the reattachment and lifting cycles are made independent from each other, so as to operate not according to a sequence of predetermined steps and times, but according to the needs that manifest themselves while the steps are being carried out.
To better highlight the problems tackled and the technical solutions proposed with the present invention we thus refer, in the following description, to a scheme of a trolley according to the invention in which the groups that carry out the cycles of the service interventions of an open-end spinning machine are inserted, as a non-limiting example.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 illustrates the scheme of an open-end spinning station in its most significant components.
FIG. 2 shows an exploded view of the parallelepiped space inside the trolley C, in which the most significant members or groups that intervene in the servicing of the spinning units are schematically indicated, made according to the present invention.
The trolley device according to the invention is defined, in its essential components, in the first claim whereas its variants and preferred embodiments are specified and defined in the dependent claims.
In the trolley according to the invention each group dedicated to the steps of the intervention cycle is independent from the others, in other words is equipped with independent actuation—by a motor or by a pneumatic piston with speed and position respectively controlled through encoders or end stop probes—and is equipped with sensors for checking whether or not thread is present in the predetermined position for the various steps.
To carry out the present invention the motors for the moving of the service members of the trolley can be brushless motors that are driven in frequency so as to obtain angular positions, speeds and accelerations that are controlled in each step of their operations in the two directions of rotation.
DETAILED DESCRIPTION OF THE INVENTION
According to a preferred embodiment of the present invention the motors for the moving of the service members of the trolley are stepper motors driven in steps, again to obtain angular positions, speeds and accelerations that are controlled in each step of their operations in the two directions of rotation.
In the trolley C illustrated in the scheme of FIG. 2 its most significant members or groups for servicing the open-end spinning unit, for both the reattachment and lifting operation, are shown:
a device 41 for controlling and positioning the thread F during the intervention cycles that acts, during the intervention cycles, to lift and determine the level and the position of the thread connected with the cone or with its quill with respect to other members of the trolley. The device 41 is moved in rotation with a motor 41 M. The position taken up by the device 41 is controlled by an absolute encoder, i.e. a member for detecting the angular position of the motor; an auxiliary actuation roller 42 of the cone 25 or of the new quill 28 , according to a clockwise/anti-clockwise rotation, during the service interventions. It can be moved forwards/backwards so as to be closer/further away with rotation of its arm 43 about a horizontal axis parallel to the front of the spinning machine, for example with a motor 43 M. The angular position taken up by the arm 43 is also controlled by an absolute encoder. The rotation of the arm 43 is also used to discharge the finished cone pushing it towards the middle plane between the sides of the spinning machine. The auxiliary roller 42 is equipped with an actuation motor 42 M capable of making the roller 42 rotate in commanded rotation in the two directions and controlled as far as speed and angular position are concerned, according to the drive that is imparted by the trolley control unit, which coordinates the operation of the various parts on-board the trolley itself with that of the spinning unit during the intervention cycles. According to a preferred embodiment of the present invention the motor 42 M is a stepper motor driven to obtain angular positions, speeds and accelerations that are controlled in every step of its operation, in the two directions of rotation. Such driving is worked out also according to the diameter of the cone 25 on which the roller 42 operates; a mobile suction mouth 44 for capturing the end of the thread on the side of the cone 25 . It can be moved forwards/backwards so as to be closer/further away with rotation of its arm 45 about a horizontal axis parallel to the front of the spinning machine, for example actuated with a motor 45 M, which works with the control of an absolute encoder; a centraliser device 46 , consisting of an engagement and displacement fork of the thread captured by the mouth 44 . It is equipped with an optical sensor 46 S of the presence of thread inside of it and can be raised/lowered with rotation of its arm 48 about a horizontal axis parallel to the front of the spinning machine to serve the subsequent preparing group.
More details on its structure and operation are described in patent EP 473.212.
The arm 48 , for example, is also actuated with a motor 48 M, which works with the control of an encoder. The sensor 46 S of the presence of thread is preferably an optical sensor and firstly detects that the thread F has passed from the mouth 44 to the centraliser itself and then it detects that the thread has been taken into the exchange position with the subsequent preparing group;
a group 50 for preparing the end of the thread, mounted in a fixed position, which receives the thread from the centraliser 46 , takes it, cuts it to size and prepares it for its re-introduction into the opening 9 of the spinning rotor 8 . More details on its structure and operation are described in patent EP 443.220. The preparer 50 is also equipped with a sensor 50 S of the presence of thread, which must detect the presence of thread after the preparation of the end before it is delivered to the subsequent introducing group; an introducing group 51 for gripping the end of the thread F prepared by the preparing group 50 and for supplying it to the spinning rotor 8 for the spinning to start up again. The introducing group also works in the lifting cycle operating on the auxiliary thread. It moves according to a trajectory from the preparing group 50 to the opening 9 to present the end of the thread to the rotor 8 , which in rotation exerts a substantial sucking action. The introducing group 51 comprises a moving structure 52 , for example with a pantograph, capable of taking its gripping member 53 from an inactive (or rest) position and putting it in various working positions to take, grip, pull, release and deliver the thread from/to the various members of the trolley and of the spinning machines described up to now. The moving of the pantograph is, for example, actuated with a motor 52 M, which works under the control of an absolute encoder to know the angular position taken up by the pantograph to take the gripping member 53 into the positions in which it must take and/or release the thread F or the auxiliary thread A. The gripping member 53 consists of a pair of elements that are opened or closed with a pneumatic cylinder 53 P counteracted by a spring, to cause their opening when the thread to be gripped between them must be introduced or when the thread gripped previously must be released, then leaving them normally closed due to the force exerted by the spring; a group 54 for lifting and opening the cone-holding arm 26 , currently known as a “cone lifter”, which disengages the cone from its roller 29 at the start and releases it at the end of each intervention cycle. The actuation open and closed of the tailstocks 27 allows—in lifting operations—the discharge of the finished cone and the insertion of a new quill 28 , gripping the thread F between its base and tailstock 27 .
The cone-lifting group 54 is actuated with a motor 54 M, with the control of an absolute encoder to know the angular position of the cone-holding arm 26 . It is also equipped with a proximity sensor 54 S that carries out multiple controls and functions.
In the lifting cycle the proximity sensor 54 S detects whether the arm 26 has been hooked with contact between cone lifter and arm; with contact carried out, it detects with its absolute encoder that the cone has the predetermined diameter (besides tolerances); it then detects, again with the encoder, that the arm is correctly raised with the cone. In the reattachment cycle, the sensor 54 S is used to detect the diameter of the cone; based upon this detection the control unit of the trolley determines the duration both of the inversion of the motion of the cone with the auxiliary roller 42 and of the suction with the mouth 44 , the size of the movement to lift the arm 26 to have a constant detachment of the cone 25 from its actuation cylinder 29 is also determined.
As well as these groups, for the lifting and starting operations the following are foreseen:
a cone 56 of auxiliary thread A that is used to start spinning, in start-up or in lifting, with the tautening transmission 57 and the pincer 58 that has the auxiliary thread A. The pincer 58 is able to intersect both the trajectory followed by the introducing group 52 and that of the following gripping member 60 , which can therefore take and control the auxiliary thread, take it to the preparer 50 and then go to introduce it to the spinning rotor 8 to carry out a reattachment of the auxiliary thread to the new thread in production.
For such a purpose the pincer 58 is mounted on a motorised arm 59 that rotates in the plane of the figure and carries the auxiliary thread to be gripped by said manipulation members. In the same way as the member 53 , the pincer 58 is opened and closed with a pneumatic cylinder 58 P counteracted by a spring, to cause it to open and close. The arm 59 is moved by a motor 59 M, with the control of an absolute encoder to know its angular position. Downstream of the pincer 58 there are scissors that, when the auxiliary thread A has been presented and gripped by such members, cut the thread leaving its end upstream still in the pincer 58 , ready for it to be subsequently taken. An optical sensor 56 S is arranged in the path of the thread A coming from the auxiliary cone 56 and at the pincer 58 intended to detect:
the presence of thread on the auxiliary cone, i.e. that it has not run out or that the thread has not broken before the sensor, that the auxiliary thread A is correctly picked up by the introducer 51 and taken to the preparer 50 , since in transportation the thread A runs inside the sensor, that the gripping member 60 has taken the thread A unwinding it from the cone 56 , again since in transportation the thread A runs inside the sensor; a hooked gripping member 60 with suction mouth for capturing, moving and centring both the auxiliary thread and the initial new thread, to present it both to the reattachment members of the auxiliary thread during the lifting cycle and to grip the new thread between quill 28 and tailstock 27 .
Such a hook with mouth 60 is equipped with a V-shaped centrer and is mounted on an arm 61 that can be extended and rotated about a horizontal axis parallel to the front of the spinning machine. Such moving of the arm 61 is actuated with a motor 61 M′ as far as the extension motion is concerned and a motor 61 M″ as far as the rotation motion is concerned. The two movements are always detected with the encoders connected to the two motors;
a device 62 for depositing and binding an initial reserve of thread at the end of the new quill 28 . More details on its structure and operation are described in patent EP 340.863. The device 62 is also moved with a motor 62 M equipped with an encoder; a quill-holding group 64 , which carries the new quill 28 picking it up from a conveyor belt arranged above the front of the machine and presenting it to the tailstocks 27 of the cone-carrying arm 26 , opened by the cone-lifting group 54 . Such a quill-holding group comprises a sort of set of many opposite horizontal rollers that allows the rotation of the quill about its axis rolling between the rollers. The set is opened and closed by actuation with a double-action piston 64 P equipped with end stop probes. The quill-holding group 64 can be moved towards/away from the gripping position to the delivery position with rotation of its arm 65 about a horizontal axis parallel to the front of the spinning machine, for example actuated with a motor 65 M, which works with the control of an absolute encoder.
A proximity sensor 64 S is arranged on the quill-holding group to detect the presence or absence of the quill in the set. Before taking the quill and leaving it detects whether the quill on the conveyor belt mentioned previously has arrived from the trolley by the lifting operation and, before going back into rest position at the end of the cycle, it detects whether the delivery set of the quill to the cone-holding arm is empty, having correctly handed it over to the grip of the tailstocks 27 , or else whether it still has the quill 28 on-board.
During the intervention cycles carried out by the trolley, the control unit of the trolley operates connected also to the control unit of the spinning unit and receives the signal detected with the sensor 15 of the presence of thread arranged at the start of the path of the thread in the collection unit preceding the compensator 16 . This sensor is preferably an optical sensor and is also used in the intervention cycles to detect:
the successful transportation by the introducing group 51 of the end of the prepared thread F in the introduction position in the opening 9 of the rotor 8 (static reading), and the successful reattachment and restarting of the collection with the thread F that runs in the sensor (dynamic reading). The automatic service trolley of open-end spinning machines according to the invention carries out its function with greater speed and flexibility in intervention cycles of the service trolley of an open-end spinning machine and has substantial advantages with respect to known devices.
The trolley according to the invention is able to detect, with the control unit that manages it, the following parameters:
the correct position, configuration and speed of each group of the trolley, the presence of manipulated thread, in the right position, on the group that at that moment receives it, the successful exchange of manipulated thread between the group that has it in delivery and the next one, the successful exchange of manipulated thread between the groups of the trolley, the spinning unit and the collection unit, the correct diameter of the cone to be lifted, the successful reattachment or lifting.
The structure of the trolley according to the invention allows its control unit to know in real time whether each step of the intervention has been carried out correctly and with a good outcome. It allows—in the case of incorrect execution—the previous step or steps to be repeated, possibly also with different adjustments to have greater probability of success. There is also the possibility of restarting the cycle from a point of the cycle upstream so as to ensure the control of the thread to be manipulated. In any case, a substantial saving of time, thread and energy is obtained.
The trolley device according to the invention also allows a cone with a diameter outside of the predetermined tolerances of the length/diameter ratio to be left on the collection unit and be treated separately, thus avoiding mechanical and pollution problems of the batch of cones with cones having a density outside specifications. | Service trolley for open-end spinning machines equipped with members dedicated to the operations in the intervention cycles and managed by the trolley's own control unit in which each member is independent from the others, being equipped with independent actuation controlled by sensors for the various steps of the intervention cycles. | 3 |
TECHNICAL FIELD
[0001] The present invention relates to a wavelength conversion device and a method of fabricating the wavelength conversion device.
BACKGROUND ART
[0002] Use of the polarization inversion phenomenon, in which the polarization of a ferroelectric is forcibly inverted, forms a periodically poled region (a poled structure) in the ferroelectric. The poled region thus formed are employed in optical frequency modulators that use surface acoustic wave, and optical wavelength conversion devices that use polarization inversion of a nonlinear polarization. This is disclosed in Patent Document 1.
[0003] FIG. 1 is a perspective view of a wavelength conversion device disclosed in Patent Document 1 (in which four devices are collectively formed). FIG. 2 is a partial enlarged perspective view of the wavelength conversion device. FIGS. 1 and 2 disclose comb-shaped electrodes 8 A and 8 B formed on an upper insulating layer 7 . The voltage applying electrode 8 A includes a rectangular-shaped main body 8 A 1 and a plurality of branch portions 8 A 2 . The branch portion 8 A 2 extends from the main body 8 A 1 in the direction −X. The voltage applying electrode 8 B includes a plurality of branch portions 8 B 2 that extend from the main body 8 B 1 in the direction +X. The branch portions 8 A 2 and 8 B 2 are mutually engaged. The branch portions 8 A 2 and 8 B 2 are aligned alternately in the direction along the Z axis. The branch portions 8 B 2 alone includes a plurality of narrow branch portions 8 B 3 that extend approximately in the direction −Z (a direction perpendicular to the X axis and along the surface of the substrate) on the surface of the substrate.
[0004] Applying voltages V 1 and V 2 performs the polarization inversion. In view of this, the voltage V 1 is set at a DC voltage of 500 V, while the voltage V 2 is set at a pulse voltage from 200 to 800 V. Voltages required for the polarization inversion vary depending on an offset angle θ. In the case where the offset angle θ is equal to 5 degrees, the voltages V 2 and V 1 are both equal to 500 V. After the polarization inversion is carried out, an intermediate of the wavelength conversion device is diced (chip processing). The dicing lines are set between the main bodies 8 A 1 and 8 B 1 and vertical to the X axis.
[0005] In order to reduce optical absorption loss caused by an adhesive layer 4 , a lower insulating layer 5 is disposed on the lower surface a ferroelectric single crystal substrate 6 . The lower insulating layer 5 is made of SiO 2 as an under cladding layer that defines a waveguide. The lower insulating film 5 has a refractive index equal to or less than 90% of a refractive index of the ferroelectric single crystal substrate 6 . The lower insulating film 5 has a thickness D 5 of 0.5 to 1.0 μm. In this example, the lower insulating film 5 of SiO 2 is preliminarily formed over a bonding surface of the ferroelectric single crystal substrate 6 . The lower insulating film 5 is laminated over a base substrate 2 via the adhesive layer 4 .
[0006] As electrodes used for the polarization inversion, a metal film 3 is preliminarily formed over the surface to be bonded of the base substrate 2 . Material of the metal film 3 is preferably Ta, Al, Ti, Au/Cr, or the like in view of bonding strength with the base substrate 2 and stabilization. The material may be, for example, Au(200 nm)/Cr(50 nm).
[0007] In order to decrease in deformation of the base substrate 2 when bonded to the ferroelectric single crystal substrate 6 as much as possible, a difference of thermal expansion coefficients between the base substrate 2 and the ferroelectric single crystal substrate 6 is equal to or less than 5%. That is, the ferroelectric single crystal substrate 6 has a thermal expansion coefficient in each direction of the horizontal surface of a value within the range of 95 to 105% of a thermal expansion coefficient of the base substrate 2 in each direction of the horizontal surface. These thermal expansion coefficients approximately match each other. This reduces substrate delamination and transmission loss increase caused by the difference between the thermal expansion coefficients. A material constituting the ferroelectric single crystal substrate 6 is preferably a single crystal of magnesium-oxide-doped lithium niobate. The substrate is known to have high resistance to optical damage. Therefore, the wavelength of light with high intensity can be converted.
[0008] Specifically, the base substrate 2 made of a non-doped LN substrate has a thickness D 2 of 0.5 mm. This thickness D 2 is preferably equal to or more than 0 . 1 mm. The base substrate 2 has a parallelism (steps on a surface) of 0.2 μm. This parallelism is preferably equal to or less than 0.3 μm. The MgO-doped ferroelectric single crystal substrate 6 has also a thickness D 6 of 0.5 mm. This thickness D 6 is preferably equal to or more than 0.1 mm. The MgO-doped ferroelectric single crystal substrate 6 has a parallelism of 0.2 μm. This parallelism is preferably equal to or less than 0.3 μm. To ensure strength of the device and flatness of the device at polishing, it is further preferable that the thicknesses D 2 and D 6 are both equal to or more than 0.2 mm.
[0009] The base substrate 2 and the ferroelectric single crystal substrate 6 have the identical crystal orientation.
[0010] In order to reduce the optical absorption loss caused by the adhesive layer 4 , an upper insulating film 7 is disposed on the top surface of the ferroelectric single crystal substrate 6 . The upper insulating film 7 is made of SiO 2 as an over coating layer that constitutes an upper cladding layer of the waveguide. The upper insulating film 7 has a refractive index equal to or less than 90 % of the refractive index of the ferroelectric single crystal substrate 6 . The upper insulating film 7 has a thickness D 7 of 0.2 to 0.5 μm.
[0011] A spacing (a cycle) X 2 between centers of the narrow branch portions 8 B 3 of the electrode formed on the upper insulating film 7 is equal to a spacing of 6.62 μm between centers of poled regions PR in the direction X. A width X 1 of the narrow branch portion 8 B 3 of the electrode formed on the upper insulating film 7 is equal to a width of 0.5 μm of the poled region PR in the direction X. In this case, this device functions as an SHG device of infrared laser light with a wavelength of 1.064 μm. Offset distance W 3 in Z-direction between the branch portions 8 A 2 and 8 B 2 of the electrode on the substrate surface is set to 150 μm. These electrodes are fabricated by metal sputtering and subsequent photolithography. The voltage applying electrodes 8 A and 8 B employ a material of, for example, Au(200 nm)/Cr(50 nm).
[0012] The following describes a voltage applying method for the inverting polarization. Spontaneous polarization of the ferroelectric single crystal substrate 6 is aligned in the Z-axis direction of the crystal. Thus a direction of the polarization inversion is the opposite direction of the Z-axis direction. Therefore, the voltages V 1 and V 2 are applied such that the electrode 8 A is at the positive side, while the electrode 8 B and the metal film 3 are at the negative side. This generates an electric field E Z inside of the material between the electrode 8 A and the electrode 8 B, and an electric field E Y inside of the material between the electrode 8 A and the metal film 3 . When the resultant electric field E S in the direction −Z is larger than a coercive electric field value of the ferroelectric single crystal, the polarization is inverted.
[0013] In short, a pair of the voltage applying electrodes 8 A and 8 B is formed on the upper insulating layer 7 . The Z axis of the ferroelectric single crystal substrate 6 has an angle of θ relative to a direction of the substrate surface. The angle θ is set such that the Z axis is aligned with the direction of the electric field E S generated inside of the ferroelectric single crystal substrate 6 . The electric field E S is generated by applying the voltage V 1 to between the voltage applying electrodes 8 A and 8 B and applying the voltage V 2 to between the metal film 3 and the voltage applying electrode 8 A alone. Applying the voltages V 1 and V 2 generates the polarization inversion in the Z axis of the ferroelectric single crystal substrate 6 . Thus the resultant electric field E S aligned with the Z axis reduces the voltage value required for the polarization inversion.
[0014] The above-described ferroelectric single crystal has a coercive electric field value of about 4 to 5 kV/mm. An electric field inside of the material with a lager value than the coercive electric field value is required to generate the polarization inversion. A conventional polarization inversion process applies a voltage to a bulk crystal wafer with a thickness of 0.5 to 1 mm. Therefore, the voltages V 1 and V 2 of a few to tens of kV have been required.
[0015] In the embodiment, the ferroelectric single crystal substrate 6 is laminated on the base substrate 2 and subsequently polished to be thin. The voltage is then applied. Therefore, the internal electric field E Z in the horizontal direction is approximately the same as before, while the internal electric field E Y in the vertical direction has become equal to or more than 100 times as large as the conventional one. This increases contribution of the internal electric field E Y in the vertical direction to the electric field E S in the direction of the polarization inversion. This results in small voltages in both of the directions. In the embodiment, the ferroelectric single crystal substrate 6 is polished to have a thickness D 6 of 5 μm and the polarization inversion was subsequently carried out.
[0016] Applying voltages forms a periodically poled structure PPS, which is formed of a plurality of poled regions PR. Use of the wet etching or the like then forms two grooves GR 1 and GR 2 that extend in the X-axis direction across the plurality of the poled regions PR. This forms what is called a core of ridge-shaped waveguide. This is disclosed in Patent Document 1.
Patent Document 1: JP-A-2007-183316
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0017] A metal film (for example, Ta) as the electrode 3 for generating the polarization inversion is formed on the surface to be bonded of the base substrate 2 . The electrode (the metal film) 3 may be irradiated by laser light with a position of the wavelength conversion device and the incident position of the laser being misaligned, at the time of an inspection of a completed wavelength conversion device or an optical-axis alignment process. The optical-axis alignment process includes aligning the incident position of the laser light with the position of the completed wavelength conversion device at the subsequent assembly process. In this case, the energy of the laser light is absorbed by the metal film, and the absorption consequently increases in temperature of the metal film. This damages the adhesive 4 and causes the thin ferroelectric single crystal substrate 6 to be peeled off. The present invention has been made in view of the above-described circumstances, and it is an object of the present invention to provide a wavelength conversion device that reduces delamination of a substrate even with the misaligned incident position of the laser light and an appropriate method of fabricating the wavelength conversion device.
Solutions to the Problems
[0018] A wavelength conversion device according to one aspect of the present invention includes: a base substrate having a transparent electrode on one surface thereof; and a ferroelectric single crystal substrate provided with an optical waveguide, where the ferroelectric single crystal substrate has an insulating film formed on one surface and is bonded to the base substrate such that the insulating film faces the transparent electrode.
[0019] The optical waveguide is preferably ridge-shaped.
[0020] The transparent electrode preferably includes an ITO film or an InTiO film.
[0021] A method of fabricating a wavelength conversion device according to another aspect of the present invention includes: a step of forming a transparent electrode on a base substrate; a step of forming an insulating film on one surface of a ferroelectric single crystal substrate; a bonding step of bonding a transparent-electrode formed surface of the base substrate and an insulating-film formed surface of the ferroelectric single crystal substrate; a polishing step of polishing the other surface of the ferroelectric single crystal substrate so as to thin the ferroelectric single crystal substrate; a step of forming an electrode film on the thinned ferroelectric single crystal substrate; a step of patterning the electrode film into a comb-shaped electrode and a counter electrode for the comb-shaped electrode; and a step of applying a voltage to between the counter electrode and the comb-shaped electrode.
[0022] The step of applying preferably includes applying a voltage to the transparent electrode so as to have the same electric potential as an electric potential of the counter electrode.
[0023] The transparent electrode preferably includes an ITO film or an InTiO film.
Effects of the Invention
[0024] The transparent electrode is formed on the surface to be bonded of the base substrate to generate the polarization inversion. The transparent electrode does not absorb the energy of the laser light even when irradiated by the laser light with the position of the wavelength conversion device and the incident position of the laser being misaligned, at the time of an inspection of a completed wavelength conversion device or an optical-axis alignment process. The optical-axis alignment process includes aligning the incident position of the laser light with the position of the completed wavelength conversion device at the subsequent assembly process. This prevents a temperature increase and peeling off of the ferroelectric single crystal substrate as in the case of using a metal electrode. Among the transparent electrodes, an ITO film and an InTiO film have high transparency and high conductive property, which leads to a preferred result. Employing the transparent electrode allows to view a surface, which is bonded to a polishing substrate, of the base substrate while grinding and polishing. Thus, an existence of air bubbles can be determined. When peeling off the base substrate from the polishing substrate after polishing, the base substrate may be peeled off while verifying a condition of delamination. This improves work efficiency. In the case where the transparent electrode is an oxide transparent electrode, an adhesive strength between the transparent electrode and the ferroelectric single crystal substrate is far more than that of a metal electrode. This also reduces delamination between the base substrate and the ferroelectric single crystal substrate at an ultrasonic cleaning after the chip processing. Further, the increased adhesive strength also improves heat resistance. Objects, characteristics, situations, and advantageous effects of the present invention will be clarified by referring to the description and the accompanying drawings below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a perspective view of a conventional wavelength conversion device (in which four devices are collectively formed).
[0026] FIG. 2 is a partial enlarged perspective view of the conventional wavelength conversion device.
[0027] FIG. 3A to FIG. 3M are schematic diagrams illustrating a fabricating process of a wavelength conversion device according to an embodiment of the present invention.
[0028] FIG. 4A and FIG. 4B are top views of a comb-shaped electrode of the wavelength conversion device according to the embodiment of the present invention.
[0029] FIG. 5A and FIG. 5C are schematic diagrams illustrating the wavelength conversion device according to the embodiment of the present invention when voltages are applied for the polarization inversion, and FIG. 5B and FIG. 5D are respective equivalent circuit diagrams of FIG. 5A and FIG. 5C .
[0030] FIG. 6 is a perspective view of the wavelength conversion device according to the embodiment of the present invention.
[0031] FIG. 7A and FIG. 7B are schematic diagrams illustrating laser lights entering into the wavelength conversion device according to the embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
[0032] FIG. 3A to FIG. 3M are schematic block diagrams illustrating a fabricating process of the wavelength conversion device according to an embodiment of the present invention. FIG. 4A and FIG. 4B are top views of comb-shaped electrodes. FIG. 5A and FIG. 5C are schematic diagrams illustrating voltage application states at the time of the polarization inversion. FIG. 5B and FIG. 5D are respective equivalent circuit diagrams of FIG. 5A and FIG. 5C . FIG. 6 is a perspective view of the wavelength conversion devices. FIG. 7A and FIG. 7B are schematic diagrams illustrating lights entering into the wavelength conversion device.
[0033] FIG. 3A to FIG. 3M are process charts in side views illustrating a method of fabricating the wavelength conversion device according to the embodiment of the present invention. In the step illustrated in FIG. 3A , a ferroelectric single crystal substrate 11 with a thickness of 0.5 mm (for example, a 5° off y-cut substrate of MgO-doped LiNbO 3 ) is prepared. In the step illustrated in FIG. 3B , an insulating film 13 on a surface of the ferroelectric single crystal substrate 11 is formed. The insulating film 13 is, for example, a deposited SiO 2 with a thickness of 0.1 to 1.0 μm (preferably 0.5 μm).
[0034] In the step illustrated in FIG. 3C , a base substrate 12 is prepared. The base substrate 12 is selected out of substrates with thermal expansion coefficients similar to that of the ferroelectric single crystal substrate 11 (for example, a y-cut substrate of LiNbO 3 ). The thickness of the base substrate 12 is set to 1 mm. In the step illustrated in FIG. 3D , a transparent electrode 14 is formed on a surface of the base substrate 12 . The transparent electrode 14 is a transparent conductive film. Material of the transparent electrode 14 is, for example, ITO, InTiO, ZnO, AZO, or GZO. The transparent electrode 14 is preferably an ITO film or an InTiO film that each have high transparency and high conductive property. The transparent electrode 14 is formed by deposition, ion plating, or sputtering method so as to have a thickness of, for example, 0.02 to 1.0 μm (preferably 0.05 μm). The InTiO film is a Ti-doped indium oxide film. The ITO film is applicable to an SHG wavelength conversion device that converts a near-infrared light with a longer wavelength than 1.2 μm (for example, the light with a wavelength of 1.26 μm) into a light with a wavelength of 0.63 μm. On the other hand, the InTiO film is especially preferable because the InTiO film may have high transmittance and low absorbance with respect to a long wavelength light, compared to the ITO film while keeping a similar conductive property to the ITO film. The reason is as follows. That is, a mobility μ of an electron as a carrier of an n-type degenerate semiconductor of the InTiO film is larger than that of the ITO film. Therefore, use of Formula (1) that expresses the relationship between the electrical conductivity σ and the mobility μ shows a possibility of a relatively lower carrier concentration n.
[0000] σ=neμ Formula (1),
[0000] where e denotes the charge of an electron. Reflection and absorption characteristics of the transparent conductive film in the near-infrared region is determined by plasma oscillation of carrier electrons in the conductive film. A plasma frequency cop is defined by Formula (2).
[0000] ω P 2 =ne 2 /εm* Formula (2)
[0000] In Formula (2), ε denotes the permittivity, and m* denotes the effective mass of the carrier (electrons in this case). As Formula (2) shows, the plasma frequency is determined by the carrier concentration n (in this case, an electron concentration). Therefore, InTiO, which allows the lower carrier concentration, may have the lower plasma frequency (that is, a wavelength λp corresponding to the plasma frequency can be shifted to a long wavelength side). This allows InTiO to have further lower reflection and absorption in the near-infrared region, compared to ITO.
[0035] In the step illustrated in FIG. 3E , the ferroelectric single crystal substrate 11 and the base substrate 12 are bonded together via an adhesive layer 15 . The adhesion is carried out in the state where the insulating film 13 and the transparent electrode 14 face one another that are formed on the ferroelectric single crystal substrate 11 and the base substrate 12 , respectively. The adhesive layer 15 is, for example, a polyimide adhesive. The adhesive layer has a thickness of, for example, 0.2 to 1.0 μm (preferably 0.5 μm).
[0036] Next, the base substrate 12 is bonded to a polishing substrate (not shown). Then, the ferroelectric single crystal substrate 11 is processed by grinding and polishing ( FIG. 3F ). The thinned ferroelectric single crystal substrate 11 ′ has a thickness of, for example 2.5 to 5.0 μm. This thickness is appropriately determined depending on usage.
[0037] In the step illustrated in FIG. 3G , a comb-shaped electrode 16 for polarization inversion is formed on a surface of the thinned ferroelectric single crystal substrate 11 ′. For example, a uniform deposition of Ta with a thickness of 0.01 to 2.0 μm (preferably 0.1 μm) on the surface of the ferroelectric single crystal substrate 11 ′ forms a film for mask. The mask is formed such that a desired comb-shaped electrode for polarization inversion can be formed. An etching is then processed.
[0038] The step illustrated in FIG. 3H is a comb-shaped electrode forming process. FIG. 4A is a plan view of the comb-shaped electrode, and FIG. 4B is a plan view illustrating poled regions after the polarization. The comb-shaped electrode main body 17 includes a plurality of comb-shaped electrode branch portions 17 A. Dimensions of a width X 1 of a comb-shaped electrode branch portion, a length Y 1 of the comb-shaped electrode branch portion, and a distance X 2 between the comb-shaped electrode branch portions 17 A are appropriately determined corresponding to a desired polarization inversion shape and phase matching condition. A width X 3 of a poled region 18 is larger than the width X 1 of the comb-shaped electrode branch portion. A condition of polarization inversion is set such that the width X 3 of the poled region and a width X 4 between poled regions are identical.
[0039] The step illustrated in FIG. 31 is a periodic polarization inverting process. FIG. 5A and FIG. 5C are schematic diagrams illustrating the voltage application states at the time of the periodic polarization inversion. FIG. 5 B and FIG. 5 D are respective equivalent circuit diagrams of FIG. 5A and FIG. 5C . The reference numerals 19 , 16 , and 14 respectively denote the comb-shaped electrode, a counter electrode, the transparent electrode. In FIG. 5A , the counter electrode 16 and the transparent electrode 14 are coupled to the negative side of a DC power of 250 to 600 V. The comb-shaped electrode 19 is coupled to the positive side of this DC power. The pulse voltage of 100 to 500 V is applied to respective electrodes. In FIG. 5C , the counter electrode 16 is coupled to the negative side of the DC power of 250 to 600 V. The comb-shaped electrode 19 is coupled to the positive side of the DC power. The pulse voltage of 100 to 500 V is applied to the respective electrodes. No voltage is applied to the transparent electrode 14 . Applying voltages in the states illustrated in FIG. 5A or FIG. 5C provides a periodically poled structure.
[0040] The step illustrated in FIG. 3J is a process for removing the applying comb-shaped electrode 19 and the counter electrode 16 .
[0041] The step illustrated in FIG. 3K is a ridge forming process. In this step, the grooves GR 1 and GR 2 illustrated in FIG. 2 are formed by dry etching, dicing, or laser processing. FIG. 6 is a perspective view of a completed wavelength conversion device.
[0042] The grooves illustrated in this drawing are formed.
[0043] The step illustrated in FIG. 3L is an end surface polishing process. In this step, the comb-shaped electrode main bodies of a chip, which includes four devices as illustrated in FIG. 1 , are cut and removed. The entering end face and the outgoing end face of laser light are then polished.
[0044] The step illustrated in FIG. 3M is an individual-dividing process. The process divides a chip including four devices into an individual device illustrated in FIG. 6
[0045] FIG. 7A and FIG. 7B are schematic diagrams illustrating laser lights entering into the wavelength conversion device. FIG. 7A shows an example of a state where a laser beam 21 and an incident position 22 of the laser beam are aligned. FIG. 7B shows an example of a state where the laser beam 21 and the incident position 22 of the laser beam are misaligned.
[0046] This application is based on Japanese Patent Application No. 2009-194416 filed on Aug. 25, 2009 in Japan by the applicants of this application, the disclosures of which are incorporated herein by reference in their entirety. Additionally, the disclosures of JP-A-2007-183316 recited as the background art are also incorporated herein by reference in their entirety.
[0047] The above description of specific embodiments of the present invention is disclosed as illustrative. This does not intend to be exhaustive or limit the present invention to the described embodiments as they are. Many modifications and variations will be apparent to one of ordinary skill in the art in light of the above teachings.
DESCRIPTION OF REFERENCE SIGNS
[0000]
2 Base substrate
3 Metal film
4 Adhesive layer
5 Lower insulating film
6 Ferroelectric single crystal substrate
7 Upper insulating film
8 A Comb-shaped electrode
8 A 1 Main body
8 A 2 Branch portions
8 B Comb-shaped electrode
8 B 1 Main body
8 B 2 Branch portions
8 B 3 Narrow branch portions
11 Ferroelectric single crystal substrate
11 ′ Thinned ferroelectric single crystal substrate
11 ′A Ridge
12 Base substrate
13 Insulating film
14 Transparent electrode
15 Adhesive layer
16 Counter electrode
17 Comb-shaped electrode main body
17 A Comb-shaped electrode branch portion
18 Poled region
19 Comb-shaped electrode
20 Lens
21 Laser beam
22 Incident position of laser beam
PR Poled region
E S Resultant electric field in a direction −Z
E Y Internal electric field in a vertical direction
E Z Internal electric field in a horizontal direction
PPS Periodically poled structure
GR 1 Groove
GR 2 Groove | A wavelength conversion device includes a base substrate having a transparent electrode on one surface thereof and a ferroelectric single crystal substrate provided with an optical waveguide. The ferroelectric single crystal substrate has an insulating film formed on one surface and is bonded to the base substrate such that the insulating film faces the transparent electrode. | 6 |
This is a division of application Ser. No. 08/588,467, filed Jan. 16, 1996 U.S. Pat. No. 5,757,027. Priority of application Ser. No. 60/007,274, filed on Nov. 6, 1995 in U.S. is claimed under 35 U.S.C. 119(e).
FIELD OF THE INVENTION
The present invention is directed to the field of electrical device testing at the wafer level. It is particularly directed to laser testing at the wafer level, and more particularly to high frequency testing of Vertical Cavity Surface Emitting Lasers (VCSELs).
BACKGROUND OF THE INVENTION
The term electrical device as used herein includes devices having electrical inputs and/or outputs, devices having optical inputs and/or outputs, and devices having electro-optical inputs and/or outputs. Thus, although the description is directed to VCSELs the inventive concept is meant to be used with any electrical device.
Performance testing of semiconductor lasers is important during the wafer manufacturing phase in order to ascertain the lasers operability and its meeting particular specifications. It is advantageous to be able to validate the performance as early as possible so as to remove faulty wafers from further processing. A VCSEL semiconductor laser permits a first level of testing at the wafer level. VCSEL technology is described in a paper entitled "Progress in Planarized Vertical Cavity Surface Emitting Laser Devices and Arrays," by Morgan et al., SPIE, Vol. 1562, pp. 149-159, 1991, which is incorporated herein by reference.
A prime using candidate of VCSEL diode technology is data communication. In data communications, as in some other technologies, the high frequency characteristics of the diode laser are extremely important. The characteristics include rise and fall times, bandwidth, relaxation oscillation frequency, and small and large signal response. The wafer level testing techniques employed to date are not usable at high frequencies due to the long return path that the laser current has to travel. The severity of this problem is illustrated in FIG. 1. FIG. 1 shows a typical closed test loop for testing the performance of a laser on a wafer. The wafer diameter is typically three to four inches. It is noted that the maximum test frequency is inversely proportional to the physical length of the electrical circuit's wire return path. A long return path reduces the maximum test frequency. The return path starts at the point the wafer test probe 80 makes contact with the top diode contact 10, usually the anode. The laser diode 15 is located along the wafer cross section 25. The return path continues through the diode's active region 20, and out through the substrate 30. The substrate 30 is generally in contact with a chuck or wafer holder 40 which acts as a common ground contact. The loop is closed with a wire 50 connected to the test signal source 60 and returns through a second wire 70 attached to the probe 80. The test current must travel several inches through the electrical circuit's test loop. The long electrical wire represents a significant high impedance inductance that severely limits high frequency testing with the probe 80. The present invention is a method and apparatus to enable high frequency testing and overcome this limitation.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a structure and method for testing an electrical device contained within a wafer. It is particularly directed where the structure is a bias-tee, and more particularly directed where the electrical device is a VCSEL.
It is a particular object of the present invention to provide a structure comprising a wafer having an electrical device contained within itself. The electrical device has a top layer stack which provides a connection for an AC/DC bias-fee electrode, an active region, and a bottom layer stack which provides a connection for a DC-only bias-tee electrode. A conductive plate is formed across the top layer stack. A semi-insulating region is formed in the top layer stack between the conductive plate and the bottom layer stack. The conductive plate provides a connection for an AC-only bias-tee electrode. The present invention is especially concerned with the case where the top and bottom layer stacks are respectively the top and bottom mirror layer stacks associated with an electrical device that is a laser.
It is another particular object to provide a structure for testing an electrical device contained within a wafer. The electrical device has a top ohmic contact on a top layer stack and a bottom contact on a bottom layer stack. A capacitor is formed across the top layer stack. An AC source is connected across the top ohmic contact and the capacitor. A DC source is connected across the top ohmic contact and the bottom contact. The electrical device is capable of producing an output having characteristics responsive to the AC and DC sources. A means is provided for measuring the output characteristics.
It is still another particular object to provide a method comprising the steps of: providing a wafer containing an array of electrical devices, in which each of the electrical devices has a top mirror layer stack forming a first electrode, a bottom mirror layer stack forming a second electrode; electrically connecting a first electrical device contact to the first electrode; electrically connecting a second electrical device contact to the second electrode; forming a conductive plate across the top mirror layer stack which forms a third electrical device contact; implanting a semi-insulating region residing in the top mirror layer stack between the conductive plate and the bottom layer stack. A variation of the method includes a step for reducing the height of part of the top mirror layer stack to bring the conductive plate in closer proximity to the lower mirror layer stack.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features, and advantages of the present invention will become apparent upon further consideration of the following detailed description of the invention when read in conjunction with the drawing figures, in which:
FIG. 1 shows a current loop path of a probe tester.
FIG. 2 shows a block diagram of a bias-tee.
FIG. 3 shows a typical laser test circuit using an external bias-tee.
FIG. 4 shows an edge view representation of a laser on a wafer with an internal bias-tee in accordance with the present invention.
FIG. 5 shows a laser test circuit using an internal bias-tee in accordance with the present invention.
FIGS. 6A-D shows the steps of VCSEL wafer formation without the capacitor of the present invention.
FIGS. 7A-D shows the steps of VCSEL wafer formation with the capacitor of the present invention.
FIG. 8 shows a top view of a wafer in accordance with the present invention.
FIG. 9 shows the capacitor plate in accordance with the present invention formed on a depression in the top mirror layer.
DESCRIPTION OF THE INVENTION
The present invention is a method to minimize the signal path length for testing an electrical device contained within a wafer to enable testing the device's electrical performance at ultra-high frequencies, and also of an apparatus implementing the method. The invention is particularly directed where the electrical device is a laser, and more particularly directed to wafer testing of a vertical cavity surface emitting laser. The term electrical device as used herein includes devices having only electrical inputs and/or outputs, devices having only optical inputs and/or outputs, and devices having electro-optical inputs and/or outputs. Thus, although the description is directed to VCSELs, the invention is not so limited. The inventive concept is meant to be used with any electrical device.
One way to achieve high frequency testing of electrical devices on a wafer is to minimize the AC test path length by providing contacts with the electrical device on the wafer's top side. A way to do this is to etch a MESA around the electrical device and to add substrate contacts. This is generally undesirable in that the MESA requires additional manufacturing steps adding cost to the manufacturing process. The present invention provides a method to shorten the AC test path length for testing electrical devices and particularly for testing VCSELS, desirably without the necessity of adding steps to the manufacturing process.
The present inventive method provides a laser on a VCSEL wafer the characteristics of a microwave bias-tee device. A bias-tee is a common microwave testing and connecting device. Generally, one port of a bias-tee passes only DC signals, a second port passes only AC signals and a third port passes both AC and DC signals. A block diagram of a microwave bias-tee 100 is shown in FIG. 2. It shows an inductor 115 input, Port A 110, a capacitor 125 input, Port B 120, and a direct input, Port C 130. Substantially, Port A 110 passes only DC signals (DC-only), Port B 120 passes only AC signals (AC-only), and Port C 130 passes both AC and DC signals (AC/DC).
A heretofore typical laser test circuit using an external bias-tee is shown in FIG. 3. It shows a laser 150 represented by a diode 152 and a series resistor 154. The diode's cathode is connected to a common ground contact 160. Usually the common ground is a chuck, wafer holder or the package case. The diode's anode is connected to the C port 130 of the external bias-tee. An AC test signal source 170 is connected to the bias-tee's B port 120 and a DC bias source 180 is connected to the bias-tee's A port 110. An inductor 162 is shown between the common ground 160 and the AC 170 and DC 180 signal sources. The inductor 162 represents the inductance of the long interconnecting wires. With this circuit arrangement, the highest frequencies that can be used for diode testing are limited by the long path length problem described above.
The present invention modifies the wafer manufacturing process such as to form within the wafer a bias-tee device inherent to a laser diode environment. This results in a shortened AC testing path that enables ultra-high frequency testing of the laser. It is preferable that the bias-tee is formed without adding any steps to the wafer manufacturing process.
The following first describes the present inventive device and concept. Methods for producing the apparatus are described subsequently. FIG. 4 shows a representation of the edge view of a VCSEL laser 200 in a wafer. It also shows a bias-tee superimposed schematically on the laser environs in accordance with the invention. In correspondence with the invention, the bias-tee is formed by defining and employing a combination of inherent wafer elements having particular useful intrinsic properties and an added conductive plate. In totality the combination of elements forms the desired three bias-tee type ports, namely, DC-only, AC-only and AC/DC. Electrical contacts are desirably placed at the defined elements to provide accessibility.
One bias-tee port results from the realization that a bottom-side contact 202 at the substrate 201, shown in FIG. 4, may be used to act as the DC-only bias-tee port. This is because of an inherent bottom-side parasitic resistance that exists between the equivalent bias-tee junction point 210 and the substrate 201 and leads connecting the bottom-side contact 202 to the testing instrumentation which have relatively high inductance. This inductance essentially presents an open circuit to high frequencies. The bottom-side parasitic resistance may be represented by a bottom-side resistor 205 between the junction point 210 and the substrate 201.
A second bias-tee port results by employing a conductive annular ring 260, also shown in FIG. 4, which surrounds the laser's light emitting window 270. The ring 260 forms an electrical contact point for the AC/DC bias-tee port. The ring 260 makes electrical connection with the laser through an inherent parasitic topside resistor 215 existing between the laser diode's anode and the ring 260. A top-side contact 280 may be connected to the annular ring 260 to make the AC/DC bias-tee port accessible for testing.
A third bias-tee port results by designing a capacitor 225 in to the wafer between the junction point 210 and a top surface conductive plate 250. The plate may be formed by modifying the processing mask of one or more top wafer layers, desirably the ohmic contact mask layer 260, as described below. An interconnect metallization contact 240 is connected to the added conducting plate 250. The capacitors 225 capacitance is a result of making the added plate to have a large surface area and to have an insulating region 220 beneath it. The insulating region 220 is a result of ion implantation in the wafers top mirror layers 285. This causes DC currents to be confined to the regions that are not implanted. The implanted region is desirably made to extend down from the top surface conducting plate 250 through the active region 260 to the bottom mirror layers 295. The capacitance is developed from the characteristics of a parallel plate capacitor formed in the wafer. The insulating region 220 presents a high DC impedance that is essentially an open circuit to DC signals. Thus the capacitor contact 240 serves as the AC only bias-tee port.
The laser test circuit with internal bias-tee has the form shown schematically in FIG. 5. FIG. 5 uses element designations that correspond with those used in FIGS. 3 and 4, to illustrate the correspondence between the internal bias-tee connection arrangement's and the external bias-tee test circuit shown in FIG. 3. FIG. 5 shows a VCSEL with an internal bias-tee 300 connected to AC and DC test signal sources. The AC signal source 170 is connected directly across the internal bias-tee's AC only port 240 and the internal bias-tee's AC/DC port 280. The DC source 180 is connected across the internal bias-tee's DC-only port, bottom-side contact 202, and the internal bias-tee's AC/DC port 280. Inductor 162 is shown between the bottom-side contact 202 and the DC 180 signal source. The inductor 162 represents the inductance of the long interconnecting wires. With this circuit arrangement, high frequencies may be used for laser testing between the AC only port 240 and the AC/DC port 280.
A preferred method for implementing the invention is to incorporate the bias-tee into the steps of making a VCSEL wafer as follows. An array of VCSEL diodes is integrated on a blank semiconductor wafer, preferably GaAs. Each diode is generally formed by having a quantum well placed between a p-type multi-layer distributed Bragg reflector and an n-type multi-layer distributed Bragg reflector. This may be formed by growing a layer structure in a molecular beam epitaxy (MBE) or a metal organic chemical vapor deposition (MOCVD). A first mask for the particular ohmic contact pattern is processed onto the wafer by putting down metal to form the ohmic contact layer according to the first mask pattern. Metal put down is generally by evaporation or sputtering of titanium Ti, platinum Pt and/or gold. A second mask is created for current/gain guiding. The wafer is implanted with ions of helium, hydrogen or preferably oxygen according to the gain guide mask pattern. A third mask is created for the device isolation pattern. The wafer is implanted according to the isolation pattern. An electrical insulation via layer is deposited over the wafer. The implanted isolation and gain guide regions form the semi-insulating region around which the capacitor is formed. A fourth mask is created according to the desired via layer opening. The via layer is etched in accordance with the fourth mask. A fifth mask is created for the interconnect metal layer. An interconnect metal, preferably gold, is deposited on the wafer according to the fifth mask. A backside metal contact layer, usually Au, is then added to the wafers backside.
For illustration purposes, the steps of VCSEL wafer formation with and without the present invention is now described. FIG. 6 shows the steps of VCSEL wafer formation without the capacitor of the present invention. FIG. 6(a) shows the water after epitaxial growth. It shows a diode 235 in an active region 290 which is between the top mirror layer 285 and the bottom mirror layer 295. In the case shown, the diode's cathode is connected to the inherent parasitic top-side resistor 215. The anode is connected to the inherent parasitic bottom-side resistor 205. FIG. 6(b) shows the formation of the top ohmic contact 245. The top ohmic contact 245 usually takes the form of an annular ring 260 surrounding the diode light emitting window 270 shown in FIG. 6(c). FIG. 6(c) shows the wafer after oxide deposition and formation of the vias in the oxide layer 230. FIG. 6(d) shows the wafer following the final steps of addition of the top interconnecting layer 280 and bottom-side contact 202.
FIG. 7 shows the same steps of FIG. 6 modified for wafer formation to include the capacitor of the present invention. For description and comparison purposes, FIG. 7(a) shows the identical starting point of a wafer after epitaxial growth. FIG. 7(b) shows the formation of the top ohmic contact 245 that now includes the capacitor plate 250. FIG. 7(c) shows the wafer after oxide deposition and formation of the vias in the oxide layer 230. FIG. 7(d) shows the wafer following the steps of addition of the top interconnecting layer 280 and the bottom-side contact 202. It is noted that with this implementation, no added processing step is needed to implement the formation of the capacitor plate 250 of the present invention. This implementation is one way to form the invention shown in FIG. 4.
According to the present invention, the ohmic contact layer is formed to include the conductive capacitor plate 250, preferably in the form shown in FIG. 8. FIG. 8 shows a top view of the wafer. It shows the plate 250 forming the capacitor to have a very large outer contact surface area. The active VCSEL is in the center and shown through the light emitting window 270. Three contacts are shown in a footprint arrangement compatible with a test system such as the Cascade Microtech (Registered) probe. The center contact is used as the bias-tee AC/DC port 280. It is connected to the annular ring 260 and preferably ends in a bonding pad 282. The two outer contacts 240 are used as the bias-tee AC only port and are commonly connected to the conductive plate 250. The outer contacts 240 preferably end in bonding pads 242. The third DC only bias-tee port is normally connected to the substrate at the bottom of the wafer and is not shown in FIG. 8.
This type of bias-tee may be implemented for testing an electrical device within a wafer without adding any steps to the wafer manufacturing process. It requires only modification of the process masks. The actual capacitor may be formed using interconnect metal on top of oxide that is itself on top of layers of semi-insulating semiconductor material. The capacitor may also be formed by using ohmic contact metal on top of semi-insulating semiconductor material. It may also be formed with interconnect metal placed directly on semi-insulating semiconductor material.
The above process is just one way of implementing an on-wafer bias-tee. Other variations of bias-tee formation using the inventive concept for a variety of electrical devices formed on a wafer are possible. Some implementations require additional manufacturing steps. For example, the capacitor capacitance may be increased by bringing the plate 250 doser to the bottom layer mirrors 295. This would broaden the low side frequency range of the bias-tee's AC only port. This is shown in FIG. 9. FIG. 9 shows the capacitor plate 250 to be formed on a depression in the top mirror layer 285. The depression is the result of an added processing step. It will be apparent to those skilled in the art that modifications to the disclosed embodiments can be effected without departing from the spirit and scope of the present invention. | The present invention is a structure and method to reduce the inductance of the AC test signal path used for testing an electrical device contained within a semiconductor wafer. This extends the frequency range of testing. It enables testing the devices perform characteristics at higher frequencies than otherwise useable. It is particularly directed for testing on-wafer VCSELs. The method provides to the electrical device the characteristics of a microwave bias-tee device. An on wafer capacitor is designed into the environment of the electrical device enabling the formation and use of the three ports of a bias-tee. Preferably, the bias-tee is formed in a manner not requiring the addition of processing steps to the wafer manufacturing process. The method further provides a way to increase the capacitance of the on-wafer capacitor. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to the cleaning of textile fibers and particularly to apparatus and methods for removing relatively small particles of debris from cotton fibers which typically are not removed by ginning and other preliminary preparation and cleaning operations.
As is well known, harvested cotton characteristically has a considerable amount of debris and foreign matter therein, such as seed, boll, leaves, plant trash and ordinary dirt and dust, which must be substantially removed before the fiber can be processed into yarn. Ginning is the operation on which is primarily relied to perform the most substantial portion of such cleaning of cotton but, although ginning equipment and operations have been substantially improved over recent years to cope with the greater amounts of debris which result from mechanized harvesting, convential ginning is unable to remove all such debris, particularly the smaller particles of debris.
As a result, a wide variety of supplemental cleaning apparatus and methods have been proposed and used at various points throughout the conventional cotton processing system to attempt to perform further cleaning of the cotton fibers subsequent to ginning. Since it is common practice to convey fibers from one processing location to another by entraining the fibers in a moving airstream, one widely employed type of arrangement includes the provision of some form of screen or filter in the airstream path for separating the fibers from the airstream while enabling any particles of debris in the airstream to pass therewith through the screen. One nagging problem which occurs in this type of cleaning operation is the tendency of the fibers to be held against the screen by the airstream and to progressively accumulate on the screen. Various mechanisms have been devised to avoid this problem, including the use of rotating or moving screen arrangements, the provision of wipers or the like to periodically remove accumulated fibers from the screen and other similar arrangements. Unfortunately, such arrangements, while generally effective for their intended purpose, render the basic cleaning devices more complicated and correspondingly more costly.
In contrast, the present invention provides a screen-type apparatus and method for cleaning small debris particles from cotton fibers which is of a simple and inexpensive construction and operation effective to avoid fiber accumulation on the screen thereof without any complicated wiping or moving screen arrangements or the like and is adapted for use at virtually any location in the cotton processing system subsequent to ginning and prior to carding.
SUMMARY OF THE INVENTION
Briefly described, the present invention provides an apparatus and method for cleaning textile fibers wherein a pneumatic conveyor, preferably a high speed fan, is employed for creating a moving airstream and entraining therein the fibers to be cleaned, and a cleaner housing is employed for receiving the fiber entrained airstream and separating the debris from the fibers. The housing is substantially enclosed and includes a perforated interior dividing wall separating the housing into a fiber accumulating chamber and a trash accumulating chamber, the perforations of the dividing wall being of a selected size sufficient for passage therethrough of debris on said fibers but to prevent passage therethrough of the fibers. The fiber entrained airstream produced by the pneumatic conveyor is directed by suitable means into the fiber accumulating chamber of the housing toward the dividing wall for impact thereagainst to separate the debris from the fibers by passage of the debris with the airstream through the dividing wall into the debris accumulating chamber and retention of the fibers in the fiber accumulating chamber. A movable airstream directing arrangement reciprocably directs the fiber entrained airstream back and forth across the transverse extent of the dividing wall to prevent the accumulation of the fibers on the wall under the retaining impetus of the fiber entrained airstream and to permit the fibers to gravitationally fall from the wall following the impact thereagainst.
In one embodiment, the reciprocal direction of the airstream is caused by a pair of airstream deflector vanes pivotably mounted in the housing on opposite sides of the location of receipt of the airstream and operatively connected for pivotal reciprocatory parallel movement in unison. In another embodiment, the reciprocal direction of the airstream is provided by an airstream conveying conduit between the pneumatic conveyor and the housing which conduit is movable from side-to-side of the housing to discharge the airstream back and forth across the dividing wall.
Preferably, the fibers collected in the fiber accumulating chamber are withdrawn from the lower end thereof by a suitable arrangement communicating therewith and are transported to a location of further processing, such as a bale press or a picker. The dividing wall is a screen arranged vertically in the housing and has an inclined lower portion arranged to direct the collected fibers to the withdrawal arrangement. The high speed fan of the pneumatic conveyor is arranged to create a high velocity moving airstream to cause the fibers entrained therein to be impacted against the dividing wall with sufficient force to cause loosening and separation of the debris from the fibers. Conveniently, a door is provided opening into the debris accumulating chamber for withdrawal therefrom of the collected debris.
It is also preferred that ion emitters be provided at predetermined locations intermediate the fan and the housing and in the fiber accumulating chamber in the housing for discharging ions into the airstream to neutralize static electrical charges in the fibers to eliminate electrical attractive forces between the fibers and the debris.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a fiber cleaning apparatus according to one embodiment of the present invention, the cleaner housing of the apparatus being shown in phantom lines to enhance the clarity of illustration of the apparatus;
FIG. 2 is a vertical sectional view of the apparatus of FIG. 1 taken along line 2--2 thereof;
FIG. 3 is a horizontal sectional view of the apparatus of FIG. 1 taken along line 3--3 thereof; and
FIG. 4 is a perspective view of a fiber cleaning apparatus similar to that of FIG. 1 according to a second embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the accompanying drawings, two embodiments of the cleaning apparatus and method of the present invention are herein illustrated and described. It is to be understood that the present apparatus and method may be employed at substantially any location in the conventional cotton processing system for supplementary cleaning of cotton fibers to remove small debris particles therefrom. Thus, for example, the present invention may be employed intermediate ginning equipment and baling equipment in the initial system of processing harvested cotton. Alternatively, the present invention may be employed in a typical yarn formation system at any location subsequent to bale opening equipment and in advance of card lap formation. Such other equipment is well known in the art and forms no part of the present invention and therefore will not be described in detail herein.
One embodiment of the supplementary cleaning apparatus 10 is shown in FIGS. 1-3 and basically includes a high-speed fan 20 connected to a cleaner housing 22 by a suitable tubular conduit 24. The housing 22 is a substantially enclosed, upstanding rectangularly-shaped hollow box 26 fabricated of sheet metal or another suitable material and includes a perforated interior dividing wall 28 extending generally vertically for substantially the full height of the box 26 and horizontally between the transverse side walls 26' of the box 26 to divide the housing 22 into a fiber accumulating chamber 30 and a debris accumulating chamber 32 on respective opposite sides of the wall 28. The fan 20 is of a conventional centrifugal type, its intake 20' being connected through a conduit section 23 in fluid communication with a source of fiber, such as the output of ginning equipment, a bale opener or the like, and its output 20" being connected through the horizontally extending conduit section 24 with the front wall 26" of the box 26 on the side threrof of the fiber accumulating chamber 30 and opening thereinto. Another conduit section 27 is connected to the box 26 at the lower end thereof and opens into the fiber accumulating chamber 30, and extends therefrom to further processing equipment, such as to the intake of a baling apparatus, a picker, a chute-feed to a card, or the like. An airstream exhaust conduit 25 and manifold 25' is connected to the rear wall 26'" of the box 26 and opens into the debris accumulating chamber 32. A door 52 is provided in the rear wall 26'" at its lower end providing access into the debris accumulating chamber 32.
As will be understood, conventional processing of the fiber which precedes the present apparatus (e.g. ginning) is ordinarily effective to remove most large particles of debris and foreign matter but such processes are generally unable to extract smaller particles which may include ordinary dirt, dust, leaf, boll and vegetable particles from the cotton plant, and other similar debris. The perforations of the dividing wall 28 are preferably of a selected size sufficiently large for passage therethrough of the aforesaid foreign matter, but sufficiently small to prevent passage therethrough of the cotton fibers. Preferably the dividing wall 28 is constructed of a screen material, the guage of which may be selectively coarse or fine as desired or necessary. The front wall 26" is stepped inwardly at 34 at a small spacing above its lower end at the location of which stepped area the conduit section 27 opens into the fiber accumulating chamber 30. The screen of the dividing wall 28 extends vertically downwardly from the top of the box 26 to an intermediate point and extends angularly forwardly at a downward incline to the inward corner of the step 34 in the front wall 26". As will be explained more fully hereinafter, the fan 20 is of a sufficient high speed capacity to convey cotton fibers in the conduit 24 at a sufficient velocity to be discharged therefrom into the fiber accumulating chamber 30 substantially horizontally to be impacted against the dividing wall 28.
As best seen in FIG. 2, a pair of planar vanes 36 are hingedly mounted to the inward face of the front wall 26" of the box 26 on opposite sides of the terminal end of the conduit section 24. Each vane 36 has affixed to its lower end an operating arm 38 which extends outwardly through a respective horizontal slot 40 in the front wall 26". The two operating arms 38 are operatively connected by a cross link 42, the respective ends of which are pivoted to the outwardly extending ends of the arms 38 whereby the arms 38 and their associated vanes 36 are caused to move pivotably in parallel relation and in unison with one another. An electrically-operated motor 44 is mounted to the outward face of the front wall 26" adjacent one side of the operating arm arrangement, a driving link 46 being pivotably affixed at one end thereof eccentrically to a drive wheel 48 driven by the motor 44, and the driving link 46 being pivotably affixed at its other end to one of the operating arms 38 whereby operation of the motor 44 is effective to reciprocably pivot the vanes 36 back and forth.
The method of operation carried out by the present apparatus will thus be understood. The fan 20 and the motor 44 are initially energized together with the other components of the processing system. Cotton fibers are conveyed through the conduit section 23 to the intake 20' of the fan 20 which operates to produce a rapidly moving airstream exiting from its output 20" and to entrain the cotton fibers in the airstream. The fibers are pneumatically transported through the conduit section 24 and across the fiber accumulating chamber 30, and are impacted with significant force against the dividing wall 28 as the airstream passes therethrough. The impact of the fibers against the dividing wall 28 is effective to loosen and separate a significant amount of the foreign matter from the fiber, most of which, because of its relatively small size, will be carried with the airstream through the perforations of the dividing wall 28 into the debris accumulating chamber 32 wherein the debris settles and accumulates at the bottom. The door 52 permits periodic removal of the collected debris as necessary. The airstream continues through the debris accumulating chamber 32 and the exhaust conduit 25 in the rear wall of the box 26 to prevent the possibility of removed debris again passing through the dividing wall 28 into the fiber accumulating chamber 30. Under ideal circumstances, the cotton fibers will fall gravitationally from the dividing wall 28 following their impact thereagainst. However, as will be understood, there exists a natural tendency that the moving force of the airstream will effectively hold some portion of the fibers against the wall 28, whereupon a progressive accumulation of fibers on the wall 28 may clog the desired escape path of the airstream and debris and negate the desired cleaning to be achieved. The reciprocating vanes 36 prevent this occurrence by channeling the airstream in a constantly changing directional path so that it is channeled back and forth across the transverse or widthwise extent of the dividing wall 28, whereby the airstream is continuously diverted away from fibers following their impact against the dividing wall 28 to permit the fibers to gravitationally fall freely therefrom and along the inclined lower portion thereof into the withdrawal conduit 27 to be carried to a location of further processing, e.g., a bale press or a picker. In this manner, the accumulation of fibers on the dividing wall 28 under the retaining impetus of the airstream is effectively prevented and the intended manner of operation of the present apparatus and method is greatly and benefically enhanced. Advantageously, the cleaner cotton fibers produced with the present invention enable the yarn producer to spin a cleaner, higher quality spun yarn with the fibers.
In FIG. 4, there is illustrated an alternative embodiment of the present invention wherein the arrangement of the diverting vanes 36 is eliminated, and the desired back-and-forth direction of the airstream is provided by employing a length of conventional flexible tubing 124 for the conduit section 24 which is connected to a horizontally extending panel 126 which is slidably mounted in channel members 136 attached to front wall 26" for reciprocable, side-to-side movement. Suitable roller bearings or the like (not shown) may be affixed to the upper and lower edges of the panel 126 to facilitate the desired reciprocable, sliding movement thereof. An operating arm 138 is pivotably affixed centrally to the panel 126 and extends therefrom to an operating motor (not shown) which may be substantially similar to motor 44 to control the desired sliding reciprocation of the panel 126. As will be understood, the side-to-side sliding movement of the panel 126 provides substantially the same back and forth diversion of the airstream as provided by the vanes 36 with the same results as described above. It will be appreciated that other mechanical arrangements could be utilized to obtain the aforesaid movement of the airstream and entrained fiber without departing from the present invention.
It is known that the conventional mechanical handling of textile fibers tends to produce static electrical charges in the fibers and debris therein creating an electrical attraction between the fibers and debris which may be difficult to overcome in cleaning operations. To neutralize such static electrical charges, the present apparatus is provided at strategic locations along the airstream path with one or more ion emitters 54 operated by a power unit 56 to emit charged ions into the airstream prior to its impact against the dividing wall 28, thereby eliminating any electrical attractive forces between the fibers and the debris so as to enable the cleaning process of the present apparatus to be carried out most efficiently. A wide variety of such ion emitters and power units are conventionally available from various companies, one example being ENER-JET brand static eliminating equipment manufactured and sold by Consan Pacific, Inc., Whittier, Calif. Preferably, a pair of emitters 54 are disposed at and extend through, each side of the conduit 24, and another pair of emitters 54 are disposed at, and extend through, the top wall of the box 26 at opposite sides thereof. Additionaly, emitters may be located, if desired, along the conduits 23 and 27 if static electricity proves to be a particularly bothersome problem in certain installations.
The present invention has been described in detail above for purposes of illustration only and is not intended to be limited by this description or otherwise to exclude any variation or equivalent arrangement that would be apparent from, or reasonably suggested by the foregoing disclosure to the skill of the art. | Apparatus and method for supplementary cleaning of cotton fibers employing a housing having an interior dividing screen separating the housing into two chambers and a fan adapted to entrain the fibers in a moving airstream and direct them into the housing against the screen for passage of the airstream and debris through the screen into one chamber and retention of the fiber in the other chamber. Reciprocably pivoting vanes divert the airstream back and forth across the screen to prevent accumulation of the fiber on the wall under the force of the airstream and to permit the fiber to fall from the wall after impact thereagainst. Alternatively, the conveying conduit may be movably mounted for side-to-side emission of the airstream into the housing. Ion emitters may be located at strategic locations to eliminate electrical attractive forces between the fibers and the debris. | 3 |
TECHNICAL FIELD OF THE INVENTION
The present invention relates to X-ray detector systems for electron microscopes.
DESCRIPTION OF THE PRIOR ART
X-ray detectors are arranged to examine X-rays produced by the bombardment of electrons onto a specimen. Analysis of the X-rays, particularly with respect to their frequency, provides an operator with information relating to the elemental composition of the specimen in addition to structural information provided by the microscope.
Known detectors have a semiconductor (such as a lithium drifted silicon crystal) mounted at the end of a probe which is introduced into the microscope close to the specimen. X-rays impinging on the crystal create a small charge therein which, after several stages of amplification, is processed to generate composition data. A block supporting the detector is mounted on a cold finger which is in turn connected to a flask of liquid nitrogen for maintaining the detector at an operating temperature of about minus one hundred and eighty degrees celsius. The cold finger is surrounded by an envelope and a vacuum is maintained between the finger and the envelope.
A problem with X-ray detectors is that they are very sensitive to contamination. The problems associated with contamination due to the build up of ice (H 2 O) is identified by G. Wirmark, G. Wahlberg and H. Norden in their paper "Characterisation of Si (Li) X-ray detector efficiencies in the low energy range" presented at the 11th International Congress on Electron Microscopy in August 1986. A known solution to the problem of ice build up is identified by F. Richle, E. Tegeler and B. Wende in their paper "Spectral efficiency and Resolution of Si (Li) detectors for photon energies between 0.3 KeV and 5 KeV ", S.P.I.E. Berlin, 1986. Here it is stated that performance of the detector can be recovered by a warming up procedure.
Vacuum flasks are commercially available which contain surfaces known as `molecular sieves` which absorb water vapour to reduce ice build up on sensitive areas. However such systems are designed to be maintained at the operating temperature of the detector (minus 180 degrees celsius) therefore the vessel must be kept topped up with liquid nitrogen even when the device is not in use. Thus with sealed detectors, having beryllium windows, a warming up procedure involves pumping the detector to maintain a vacuum while removing water vapour as it evaporates. Such a procedure is usually only undertaken as part of a major overhaul involving the return of the detector to the manufacturer. For windowless detectors a warming up procedure may involve using the pumping system of the microscope.
Heating up the detector not only removes ice from the detector crystal itself but also removes contaminants from other components which, when present, generate noise. Another significant advantage is that it anneals out radiation damage of the crystal. However problems with known procedures are that they are time consuming, hence expensive, and may cause contaminating material to be transferred from the detector to the microscope, or vice versa.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved system for treating a detector.
According to a first aspect of the invention there is provided a detector system comprising a cold finger having a first end coupled to a heat sink at a temperature substantially below ambient temperature, an X-ray detector mounted at an opposite end of the cold finger wherein heat is transferred along the cold finger to maintain the temperature of the detector substantially below ambient temperature during normal operation, an envelope surrounding the cold finger wherein a vacuum is maintained between the cold finger and said envelope; and conditioning means for locally increasing the temperature of the detector for a predetermined interval while maintaining the heat sink substantially at the operating temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an X-ray detection system including a detector assembly positioned within an electron microscope;
FIG. 2 details the detector assembly shown in FIG. 1;
FIG. 3 shows a circuit for effecting conditioning of a detector mounted on the assembly shown in FIG. 2; and,
FIG. 4 shows a typical temperature curve for the detector assembly detailed in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An X-ray detector system connected to an electron microscope is shown in FIG. 1. A specimen 10 is supported within a microscope housing 11 forming an enclosure which in maintained under vacuum during operation. A detector probe 12 enters the housing so that a detector assembly 13 receives X-rays from the specimen during electron bombardment. The detector assembly 13 is mounted on a cold finger 14 surrounded by an envelope 15. The cold finger 14 is connected to a vessel 16 containing liquid nitrogen at a temperature of about minus one hundred and eighty degrees Celsius. The vessel 16 is surrounded by a flask 17 and a vacuum is maintained within said flask and the envelope 15.
The detector shown in FIG. 1 is a window-less detector allowing X-rays to pass from the specimen to the detector with no solid window inbetween. The vacuum within the envelope 15 and flask 17 is maintained by a pumping system 18 which forms part of the microscope. In sealed beryllium-window detectors the cold surfaces create a cryopump to provide a vacuum and remove water vapour.
The detector assembly 13 is shown in FIG. 2. A mounting block 20 of aluminium is connected to the cold finger 14 and a lithium drifted silicon detector 21 is secured to the opposite end of said block. A field effect transistor (FET) 22 is mounted on the block which provides a buffer amplifier for the output from the detector.
The assembly shown in FIG. 2 is a first embodiment of the invention in which the means for locally increasing the temperature of the detector is an electrical resistor 23 sealed to the mounting block 20. The resistor 23, a 47 ohm one quarter watt metal film resistor, and a serially connected polyswitch 24 (type PDS.21252 supplied by RAYCHEM) are cemented onto the block using silver-loaded epoxy cement. The epoxy is cured after application and then sealed to provide additional strength.
A circuit for effecting conditioning of the detector is shown in FIG. 3 and a typical response curve is shown in FIG. 4. On initiating a conditioning cycle the polyswitch 24 allows four hundred milli-amp (mA) to pass through the resistor which in turn dissipates heat to the block 20. However on reaching plus ten degrees celsius the polyswitch operates to increase the resistance in the circuit and hence reduce the heating current to two hundred mA. The block then cools until equilibrium is reached at about minus ten degrees celsius. This temperature is maintained for up to one hour until the detector is fully conditioned.
In a complete detection system the conditioning circuit is included as part of the main control circuit. On operating a "condition detector" switch the system is placed into a "condition detector" mode. A high voltage supply to the detector, required for normal operation, is removed and the condition cycle, as detailed above, is initiated. Once temperature equilibrium has been reached conditioning continues for a predetermined interval, say one hour. After this interval the heating current is removed and on reaching the operating temperature the high voltage to the detector is restored and an operator is notified, by means of a suitable display, that the detector has returned to its normal operational mode. It can therefore be seen that a detection system embodying the present invention may effect a conditioning cycle over a weekend, evening or even a lunch break. Furthermore experiments have shown that the detector is not damaged in any way by the conditioning process.
As an alternative to providing a heating resistor other forms of heating are possible. Thus heating may be effected by directing a high intensity light source onto the detector from a laser. In another embodiment the probe includes a removeable link which, to effect conditioning, disconnects the detection assembly from the cold vessel. Heating is then achieved by transfer from outside the system until the required temperature has been attained. | A technique for conditioning X-ray detectors which are introduced into electron microscopes and maintained at an operating temperature substantially below ambient is disclosed. Localized heating is applied to the detector by, for example, electrical resistance heating, whereby the detector is conditioned for about an hour without the heat sink being removed. | 6 |
The present application is a divisional of U.S. patent application Ser. No. 11/658,087, filed Jan. 22, 2007, the entirety of which is incorporated herein by reference. The parent application is a national stage application of PCT/NO05/00262, filed Jul. 15, 2005.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention concerns a method and equipment for heat recovery from exhaust gas from a process plant, for instance raw-gas from an electrolysis plant for the production of aluminium. Such exhaust gas may, before it is cleaned, contain dust and/or particles that will form deposits on the heat recovery equipment and thus reduce the efficiency of the heat recovery to an undesired, low level.
(2) Description of Related Art
Various industrial processes produce exhaust gases that can be contaminated by particles, dust and other species that can cause fouling in energy recovery equipment. Such fouling will result in reduced efficiency, and will require extensive maintenance such as cleaning of the surfaces exposed to the gas flow. Thus, energy recovery units are placed downstream a gas cleaning plant, after the gas has been cleaned. With respect to optimising the energy recovery, it is of interest to arrange the recovery units as close to the industrial process as possible, where the energy content in the exhaust gas is at its maximum. This implies that the energy recovery units have to be arranged upstream the gas cleaning plant, because such plants are often localized relatively distant to the industrial process.
U.S. Pat. No. 4,339,249 discloses a heat exchanger for recovery of heat energy from dust containing waste gases. The exchanger is constructed to recover much of the dust entrained in the gases and includes a hollow duct through which the waste gases pass, and which contains first and second tube bundles arranged one after the other and a dust collection surface between them. The heat content in the waste gases is transferred to water passing through the two tube bundles and dust is deposited on the dust collection surface. The tubes in the bundles are arranged in a serpentine configuration, and the first bundle is constructed of a smooth surface tube arranged to remove heat from the dust containing gases upstream the dust collection surface. Thus, when the gases reach the finned tube bundle, it is stated in the publication that no deposition (and clogging) of the narrow spaces between the fins will occur. Thus from this citation it is learned that the dust containing gases should be treated in a first cooling step and then in a separating step before it is entered into the section comprising a second finned tube bundle of a flanged tube (or tubes).
For example, exhaust gas from aluminium electrolysis furnaces contains large amounts of energy at a relatively low temperature level. This energy is currently utilized only to a small extent, but it can be used for heating purposes, process purposes and power production if technically and economically acceptable solutions for heat recovery are established. The temperature level achieved in the heated fluid is decisive to the value and usefulness of the recovered thermal energy. The heat should therefore be extracted from the exhaust gas at as high an exhaust gas temperature as possible. Other examples of industrial processes that produce large exhaust gas volumes containing dust/particles are: Ferro-, alloy- and other smelting plant industries that typically operates with dust-containing exhaust gases at 300° C. and higher, and the low temperature section in waste incineration (i.e. economizer and air preheating sections) that typically operate at 300° C. and lower.
The exhaust gas from electrolysis furnaces is transported through a suction system by means of fans, and the power consumption of the fans depends on the volume flow of exhaust gas and the pressure drop in the system. The power consumption can be reduced by a reduction of these quantities. Cooling the exhaust gas will contribute to reduced volume flow rate and pressure drop, with reduced fan power as a consequence. The largest reduction in pressure drop is achieved by cooling the exhaust gas as close to the aluminium cells as possible.
When improving or scaling-up an industrial process, for instance increased current (amperage) in relation to a given cell-design in a aluminium electrolysis plant, the raw-gas temperature and thus its pressure inside the superstructure will increase as there will be more heat present above the top of the cell. This can result in cell puncture, i.e. the same level of pressure will be present at the inside as that of the outside of the cell. By such puncturing, the emission of process gases to the production hall will increase.
This problem can be solved in three ways:
Enchange the encapsulation at the cell top, which can be difficult in practice. Increase the suction by installing higher fan capacity. To avoid large pressure drop in the raw gas channels, these must be increased in size as well. The gas cleaning plant will have to be re-designed to avoid reduced efficiency or overloading components in the gas cleaning process. In total this solution will be expensive with regard to both investment and operation costs. Cooling of the raw gas upstream the fans together with heat recovery, a solution that will reduce both the raw gas volume flow rate and the pressure drop in channel system and gas cleaning plant. The suction can thereby be increased without the need of changing the dimensions of channels and gas cleaning plant.
BRIEF SUMMARY OF THE INVENTION
The present invention can be utilised in accordance with the last mentioned technical solution, which will be the most economical one as the heat removed from the raw gas can be utilised in other processes or applications.
The process is here exemplified by a plant for aluminium production, and is characterised in that large amount of exhaust gas (in the order of 5000 Nm 3 /h per aluminium cell) containing low-temperature energy (typically approximately 120-140° C., but can be increased up to approximately 200° C.) being extracted/sucked from the aluminium cells. The exhaust gas contains pollutants such as particles and gaseous components, which must be removed from the exhaust gas in a cleaning process before it can be emitted.
The energy content of the exhaust gas can be recovered in a heat exchanger (heat recovery system) in which the exhaust gas gives off heat (is cooled) to another fluid suitable for the application in question. In principle, the heat recovery system can be located
upstream of the cleaning process—where the heat recovery system must operate with a gas containing particles downstream of the cleaning process—where polluted components and particles in the gas have been removed.
As the cleaning processes available today must operate at a low temperature level, energy recovery is, in practice, relevant only for the alternative where the heat recovery system is located upstream of the cleaning process. This means, in practice, that the heat recovery system must be able to operate with hot gas containing particles.
On account of forces of inertia, diffusion and poresis, particles and trace components in the exhaust gas will be deposited on the heat-transfer surface of the heat recovery system and form an insulating layer that reduces the heat transfer. Without sufficient control, the effectiveness (the level of heat recovery) of the heat recovery system will be unacceptably low, and the pressure drop (and the associated work to pump the exhaust gas through) will be large. The thickness of the deposited coating can be controlled using active or passive techniques.
Active techniques mean that the deposit is removed fully or partially by means of mechanical sweeping, hydraulic or pneumatic flushing/washing, impact or impulse sweeping or equivalent methods.
Passive techniques mean that no form of external equipment or appliance is used to control the particle deposit. It is instead controlled and limited by means of process parameters, for example the velocity of the exhaust gas.
The present invention includes a passive technique for limiting the deposit in the heat recovery system.
In addition to the heat recovery system recovering heat from the exhaust gas, it is necessary for this to be done without the pressure drop for the exhaust gas through the heat recovery system being too large. Fans are used to drive the exhaust gas through the system, and the energy that must be supplied to the fans is approximately proportional to the pressure drop and volume rate. It is therefore important for the heat recovery system to be designed in such a way that the pressure drop is as low as possible.
Reducing the volume flow rate produces a gain in the form of lower power consumption for the fans that drive the exhaust gas through the system. A smaller volume flow rate can be achieved by means of
i. reducing the exhaust gas temperature before the fan ii. reducing the quantity of exhaust gas extracted from the electrolysis cells.
Reducing the volume flow also reduces the pressure drop in other parts of the system.
A reduction in the volume extracted/sucked from the electrolysis cells will normally not be possible, as it will result in increased pressure within their enclosures. Increased pressure will further make the cells more vulnerable to puncturing, resulting in an increase in gas and dust escaping to the work environment.
Reducing the amount of exhaust gas extracted will generally entail an increase in gas temperature out of the electrolysis cells (which reduces the gain from the reduced amount of gas) unless the exhaust gas is cooled before the fans. The pressure drop in the system depends on the gas speed, which can be reduced by reducing the gas temperature. The proposed solution entails a net reduction in power consumption for the fans precisely because the exhaust gas is cooled. In addition, the heat recovered from the exhaust gas is available as process heat for various heating and processing purposes.
The proposed solution will, for new plants, allow for smaller dimensions in gas cleaning plants inclusive their transport channels, because the exhaust gas volumes to be transported will be reduced.
It is desirable (but not necessary) to have a heat recovery system that is relatively compact, i.e. that has minimum volume. This is to reduce the footprint and costs.
Purpose
The purpose of the present invention is to recover heat from exhaust gas containing dust/particles from industrial processes, in particular aluminium cells, in one or more heat recovery systems located upstream of the gas cleaning process by using a passive technique to keep the coating deposits on the heat-recovery surfaces under control and to achieve stable operation.
By cooling the raw gas from an electrolysis plant for production of aluminium, it is possible to keep the gas pressure inside the enclosures of the cells at a sufficient low level to avoid increased effluent of gas and dust to the ambient air.
These and other advantages can be achieved with the invention as it is defined in the attached claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described in further detail in the following using examples and figures, where:
FIG. 1 shows results from tests with elliptical, finned tubes,
FIG. 2 shows a calculation of the heat exchanger volume for 120° C. inlet temperature to the heat recovery system, 6.5 MW thermal power. Exhaust gas flow rate: 440,000 Nm 3 /h, inlet temperature to the fan: 80° C. Results for the permitted pressure drop in the heat recovery system of 3000 Pa are indicated,
FIG. 3 shows a calculation of the heat exchanger volume for 180° C. inlet temperature to the heat recovery system, 6.5 MW thermal power. Gas flow rate: 176,000 Nm 3 /h, inlet temperature to the fan: 80° C. Results for the permitted pressure drop in the heat recovery system of 4,000 Pa are indicated,
FIG. 4 shows test equipment for a heat recovery system embodiment with elliptical, finned tubes.
FIG. 5 shows an embodiment of the equipment used in the method for recovering heat from an exhaust gas.
DETAILED DESCRIPTION OF THE INVENTION
The heat recovery system may consist of one or more hollow elements such as tubes with a circular or elliptical/oval cross-section, with or without fins fitted on the outside of the tubes, see FIG. 4 . The tubes may be made of carbon steel that has been treated in a galvanisation process. Other materials may also be relevant for this application, such as aluminium. The external surfaces of the tubes that will be in contact with particles/dust may also be treated in accordance with relevant surface treatment techniques to produce an increased slip effect. Relevant slip coatings may also be included in such treatment techniques.
The exhaust gas flows on the outside of the tubes and perpendicular to the axial direction of the tubes. The tubes are packed in a regular pattern with the center-to-center tube distance adjusted so that the mass flux (mass flow rate per unit of flow cross-section) and momentum of the exhaust gas are kept at a level at which a balance is achieved between particle deposition and particle removal on the heat-transferring surfaces. The heat recovery system is enclosed by side walls and thus forms a channel through which the exhaust gas flows. No special requirements are made for the coolant that flows inside the tubes. For example, the coolant may consist of liquid/steam or gas such as water/steam or air.
To achieve a balance between particle deposition and particle removal, there must be a certain minimum mass flux and momentum for the exhaust gas. This threshold is both geometry-specific and process-specific. Tests are carried out to identify the threshold value for some specific geometries (Ø36 mm circular tubes, Ø36 mm circular tubes with Ø72 mm annular fins, 14×36 mm elliptical tubes with rectangular fins) in a small-scale test setup. In the test, real exhaust gas from aluminium production is used, with particle concentration and particle distribution typical for this process.
The net particle/dust deposition on the heat transfer surfaces is controlled by the transport of particles/dust to the surface, adhesion at the surface and entrainment/removal from said surface. The transport to the surfaces is influenced by the concentration of particles in the gas, together with convection, diffusion, and phoresis for small particles, while momentum forces and inertia forces are more dominant for larger particles. The adhesion to the surface is influenced among other effects by van der Waal bonding forces, capillary forces, phoresis, and gravity. Entrainment/removal of particles/dust from the surface is influenced by shear forces in the flow, grinding and collisions caused by larger particles that hit the surface, together with gravity forces. A balance between particle deposition and particle entrainment/removal is achieved by the fact that the mechanisms causing the entrainment/removal of particles are augmented to a level that balances the deposition mechanisms. For a given system these mechanisms can be expressed by characteristic gas velocities, whereby various velocities will give corresponding net thickness of the fouling layer. Said layer will insulate against the heat transfer. These characterising gas velocities can in principle be established by theoretical calculations, but will in practice be determined by experiments and measurements, due of the complexity of the issue. An optimised velocity will be a velocity that, for the given system, renders an acceptable reduction in heat transfer caused by fouling at stable conditions, without rendering a too high pressure drop. In the experiments carried out, acceptable raw gas velocities were measured to be approximately 12 meters/second or higher.
The exhaust gas temperature in the tests was approximately 130° C., and the tube wall temperature approximately 70° C. An example of test results in shown in FIG. 1 (elliptical tubes with rectangular fins), where the resistance to heat transfer on account of the deposit layer (fouling factor) is shown as a function of time for various free stream gas mass fluxes. A stable state (no change in the fouling factor) is typically achieved after 50-500 hours of operation at a gas velocity of approximately 11-13 m/s (equivalent to approximately 9.5-11 kg/m 2 s). [For the tests shown in FIG. 1 , stable conditions occurred at a gas velocity of approximately 11 m/s (10 kg/m 2 s) after approximately 400 hours of operation.]
The reduction in heat transfer under stabilised conditions is compensated for by a moderate increase in the heat-transfer surface, typically 25-40% in relation to a clean heat-transfer surface. At the same time, the pressure drop for the exhaust gas through the heat recovery system is kept at an acceptable level. These goals are achieved via a combination of tube/fin geometry, tube packing and flow conditions.
Examples of dimensioning heat recovery systems for recovery of 6.5 MW heat from exhaust gas at 120° C. and 180° C. are shown in FIG. 2 and FIG. 3 . These examples are based on given pressure drop correlations and an assumed total pressure drop in the heat recovery systems equivalent to a power demand in the fans of 10%, respectively 5% of the energy recovered. In these examples, only designs with exhaust gas velocities (the velocity in the open flow cross-section in the heat recovery system) over approximately 11-13 m/s (9.5-11 kg/m 2 s) will achieve stable conditions. The other designs will experience unacceptably high deposits over time. As the figures show, only elliptical finned tubes will allow a velocity high enough for stable conditions to be achieved at the specific pressure drops.
The relationship between mass flux and momentum for the exhaust gas and stabilised coating resistance (fouling factor) is a function of exhaust gas temperature and composition, plus particle concentration and distribution. At the same time, the pressure drop is a function of tube and fin geometry, tube packing, exhaust gas temperature and speed and total heat-transfer surface. The relationships demonstrated so far are therefore not universal. Whether a heat recovery system can operate with stable coating conditions and acceptable pressure drop depends on the process (temperature level, particle characteristics, requirements for thermal efficiency for the heat recovery system, etc.). The relationships found are, however, regarded as typical for applications for heat recovery from exhaust gas from aluminium production based on prebaked electrode technology.
Although the present invention has been defined on the basis of prebake technology, the principles of the present invention may also be applied in connection with systems that use so-called Søderberg technology, and other industrial processes, exemplified by ferrosilicon smelting industry and waste incineration.
In the examples, tubes with circular and oval (elliptical) cross-sections have been mentioned. However, in other embodiments, it is possible to operate with an external geometry of the tubes where the tubes have been optimised with respect to particle deposition, heat transfer and pressure drop. For example, the cross-section of the tubes may principally be designed as a wing section.
Moreover, electrostatic or other similar methods may also be used to counteract deposit formation on the heat recovery equipment.
Further technical design adjustments can be carried out based upon the characteristics of the exhaust gas the heat shall be recovered from. This can by example involve the choice of material used in the recovery unit or its surface treatment, in particular in relation to recovering heat from humid or corrosive gases.
Further design adjustments with regard to the geometry of the recovery unit, the velocity of the exhaust gas at the surface thereof and other flow dependent issues can be carried out based upon the characterising features of the exhaust gas to be treated, such as gas velocities and temperatures. The density and the dimensions of the dust/particles in the exhaust gas may also be of importance with regard to the design of the heat recovery unit. | The present invention relates to a method and equipment for recovering heat from exhaust gas removed from an industrial process, such as an electrolysis process for the production of aluminum. Heat is recovered by means of an extraction/suction system, where the exhaust gas contains dust and/or particles. The heat is recovered as the exhaust gas being brought into contact with heat-recovery elements. Flow conditions and the design of the heat recovery elements are such that the deposits of the dust and/or particles on the surfaces stated are kept at a stable, limited level. In preferred embodiments, the heat-recovery elements have a circular or an extended, elliptical cross-section and may be equipped with fins or ribs. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 61/473,371, filed Apr. 8, 2011.
FIELD OF THE INVENTION
The present invention relates generally to the field of sleeping bags. More particularly, the present invention relates to sleeping bags having a cavity formed therein for storing a removable book.
BACKGROUND
Sleeping bags are well known. Typically, sleeping bags are formed of a body having a bottom cover attached to a top cover along a side. Two of the three other sides of the top cover and bottom cover can be attached to each other by a zipper, thereby allowing a user easy access to the interior of the sleeping bag. Some sleeping bags also have an integral pillow attached to the top or bottom cover of the sleeping bag.
However, most sleeping bags are simply utilitarian and do not provide any entertainment for children. Therefore, a need exists for a sleeping bag capable of providing entertainment to a child.
SUMMARY OF THE INVENTION
The present invention provides a sleeping bag formed from a bottom cover member and a top cover member attached along one side. The top cover member and bottom cover can be formed from one integral member that is folded to define the top cover member and the bottom cover member or from two separate members joined at a seam. The top cover member and the bottom cover member are removably attached along two other sides via a zippered connection.
The top cover member has a cavity with an opening. A book is located in the cavity and is removably attached to the interior of the cavity. The opening of the cavity may be sealed by a zippered connection to secure the book within the cavity. Preferably, the book is able to be read by the child while in the sleeping bag.
In some embodiments, the book is removably attached to the interior of the cavity using fastening means such as a hook and loop connection (e.g., Velcro™) or a zippered connection. The book is preferably a children's book for providing entertainment to a child. Because the books are removable, they can easily be changed if a child is no longer entertained by the book currently in the sleeping bag.
The sleeping bag may also contain a pillow member attached to the top cover member or the bottom cover member of the sleeping bag. In some embodiments, the pillow member is removably attached to the sleeping bag (e.g., via a zippered connection).
The top cover member, the bottom cover member, and/or the pillow member may contain a removable foam insert. This allows the foam insert to be replaced and washed. In some embodiments, the foam insert has a waterproof covering so that it can easily be cleaned.
The book can be constructed of any known pliable materials such as cloth, plastic, or rubber. The material must be pliable so that the book can be rolled up along with the sleeping bag.
The sleeping bag may further comprise a carrying member adapted to store the sleeping bag when it is rolled up. In some embodiments, the carrying member has a handle or shoulder straps for easy transport of the carrying member.
In a further embodiment, the interior of the cavity has a sealable (e.g., with a zipper) pocket adapted to store an audio device, such as an MP3 player or a CD player, that contains a recording of the book. Such an audio device is useful for children who have not yet learned to read or have difficulty reading. In some embodiments, the content for the device can be obtained from the Internet.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described by way of example only with reference to the attached drawings, in which:
FIG. 1 depicts a view of the sleeping in a closed position;
FIG. 2 depicts an alternate view of the sleeping bag of FIG. 1 ;
FIG. 3 depicts an enhanced view of corner B of the sleeping bag of FIG. 1 showing the zipper detail;
FIG. 4 depicts a view of the sleeping bag of FIG. 1 showing the top cover member opened to expose the book;
FIG. 5 depicts a view of the sleeping bag of FIG. 4 after the book has been opened;
FIG. 6 depicts a view of the book of FIG. 4 after it has been removed from the sleeping bag and opened;
FIG. 7 depicts a bottom view of the book of FIG. 4 after it has been removed from the sleeping bag;
FIG. 8 depicts a view of the sleeping bag of FIG. 4 after the book has been removed from the sleeping bag;
FIG. 9 depicts a bottom view of the sleeping bag of FIG. 1 ;
FIG. 10 depicts a top view of the foam body insert after it has been removed from the sleeping bag;
FIG. 11 depicts a top view of the pillow insert after it has been removed from the sleeping bag;
FIG. 12 depicts a view of the sleeping bag of FIG. 1 partially rolled up;
FIG. 13 depicts a view of the sleeping bag of FIG. 12 fully rolled up.
FIG. 14 depicts a carrying case for use with the sleeping bag of FIG. 1 ; and
FIG. 15 depicts an alternate view of the sleeping bag of FIG. 4 wherein the cavity containing the book has a sealable pocket.
DETAILED DESCRIPTION
With reference to FIG. 1 , depicted is a top view of sleeping bag 100 . Generally, sleeping bag 100 comprises top cover member 102 , bottom cover member 104 (not shown), and pillow member 105 . In some embodiments, pillow member 105 may be removably attached to sleeping bag 100 (e.g., via a zippered connection).
Top cover member 102 and bottom cover member 104 can be formed of a single member or formed from two members and joined at seam 106 . Zippered connection 108 extends around the periphery of two sides of top cover member 102 and bottom cover member 104 allowing them to be removably attached to each other using zipper 110 , thereby allowing a user easy access to the interior of sleeping bag 100 . For example, a user can open sleeping bag 100 by drawing zipper 110 from point A, to point B, and then to point C. The portion of sleeping bag between points C and D remains as a closed hinge so that top cover member 102 can be pivoted to an open position. Sleeping bag 100 can be closed by advancing the zipper from point C, to point B, and then to point A.
FIG. 2 depicts an alternate view of sleeping bag 100 in its closed position. Should the user want to read the book contained in top cover member 102 , a second zippered connection 202 is provided around the periphery of top cover member 102 defining a cavity therein. FIG. 3 depicts an enlarged view of corner B showing zippered connections 108 and 202 . Zippered connection 202 is used to access the cavity containing the book while zippered connection 108 provides access to the interior of sleeping bag 100 as previously described. Referring back to FIG. 2 , the cavity can be accessed by moving zipper 204 from point A, to point D, to point C, and then to point B. This opens three sides with the connection between A and B remaining closed and serving as the pivot for top cover member 102 . The arrangement of the zipper allows an occupant of the sleeping bag to utilize the contents of the sleeping bag while situated in the sleeping bag. For example, FIG. 4 depicts the sleeping 100 after zippered connection 202 has been opened, revealing the cover of book 300 . Utilizing this arrangement, the occupant can read the book while residing in the sleeping bag 100 .
Book 300 can be made of any flexible material that aids in warmth such as cloth, plastic, or rubber. Book 300 can either be read in sleeping bag 100 , as shown in FIG. 5 , or removed via a removable connection and read alone as shown in FIG. 6 .
FIG. 7 depicts the reverse side of book 300 having hook connectors 702 which mate with corresponding loop connectors 802 on sleeping bag 100 as shown in FIG. 8 , thereby providing a removable connection between book 300 and sleeping bag 100 . It should be appreciated that other types of releasable connections, such as snaps, may also be used.
Sleeping bag 100 contains a base support of foam material located in bottom cover member 104 as shown in FIG. 9 . An additional zippered connection 902 or the like can be provided from points E to F to allow insertion and removal of a foam insert into the base of sleeping bag 100 . Likewise, to permit removal of pillow inserts, a zippered connection 904 can be provided in pillow member 105 , for example from point G to H, on the sleeping bag 100 , thereby allowing the pillow insert to be removed for washing or replacement purposes.
As shown in FIG. 10 , there is a foam insert 1002 which is the base portion that is inserted through zippered connection 902 ( FIG. 9 ) in the sleeping bag 100 . Foam insert 1002 may optionally comprise waterproof cover 1004 , thereby allowing the foam to be easily wiped clear without requiring it to be washed in a machine.
FIG. 11 similarly shows pillow insert 1102 which would be inserted zippered connection 904 ( FIG. 9 ). Likewise, pillow insert 1102 may be made of a foam material having a waterproof cover 1104 .
As with other sleeping bags, sleeping bag 100 can be rolled up as depicted in FIGS. 12 and 13 . After sleeping bag 100 has been rolled up, it can be inserted into carrying member 1402 for easy transportation as depicted in FIG. 14 . Carrying member 1402 contains shoulder straps 1404 so it can be used as a backpack and zippered connection 1406 for securing sleeping bag 100 within carrying member 1402 .
FIG. 15 depicts an alternate view of sleeping bag 100 in an opened position. As shown, sleeping bag 100 may optionally contain zippered pocket 1502 for a CD player and/or MP3 player having a recording of book 300 for younger children who do not read. Each time a different book 300 is placed in sleeping bag 100 , the recording can be changed by replacing the CD in the CD player or downloading a new track to the MP3 player.
While the above description constitutes a plurality of embodiments of the present invention, it will be appreciated that the present invention is susceptible to further modification and change without departing from the fair meaning of the accompanying claims. | Disclosed herein is a sleeping bag having a removable book located in a cavity in the top cover of the sleeping bag. The book is accessed by unzipping the opening of the cavity. The book is removably attached to the interior of the cavity using fastening means such as a hook and loop connection. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to gearset transmissions, and particularly large gearset transmissions with a wide variety of speeds suitable for use in work vehicles such as agricultural and industrial equipment.
2. Description of the Related Art
There are a great many powershift transmissions known having a large variety of speeds. Such variety of speeds is particularly useful for large vehicles, and especially work vehicles such as agricultural and industrial tractors. Such vehicles may need a dozen or more speeds in a very small range, e.g., 0.5 to 5 kilometers per hour, and just a few at higher speeds, e.g., up to 40 kilometers per hour.
Such vehicles typically have a large mass, or are under a significant load (for example, plowing), so that the change in energy levels between the rotating components of the transmission should be held to a minimum between any two successive speeds. This is necessary to minimize the time required for a shift, thereby allowing a smoother shift and preventing the vehicle from coming to a lurching halt. At the same time, the transmission size must also be held to a minimum in order to fit into an existing vehicle.
Funk Manufacturing currently produces a powershift transmission for Ford/New Holland row crop tractors which provides 18 forward speeds and 9 reverse speeds. To do this, nine clutches and attendant gears are arranged with six clutches in a speed section and three clutches in a range section. The six clutches in the speed section can provide nine useable gear ratios, while the three clutches in the range section provide two forward ranges and one reverse range.
While at first it might appear that nine additional speeds could be provided simply by adding another forward range, this is not practical in reality. First, there is the simple limitation of space. Second, and more important, the necessary readjustments to the gear ratios of the speed gears required so that the bulk of these ranges will still be in the desired, limited range of, e.g., 0.5 to 5 kilometers per hour, would produce a very undesirable range of reverse speeds. In addition, the momentum which must be changed upon shifting from one of these ranges to another would be undesirably high.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a full powershift transmission for a work vehicle capable of providing 24 forward speeds and 12 reverse speeds.
This object of the invention is accomplished by providing a design using 10 clutches, with six clutches in a speed section and four clutches in a range section. The clutches and gears in the speed section are arranged to produce six forward speeds and three reverse speeds, so that reverse becomes a speed rather than a range. The four clutches in the range section provide four ranges, resulting in 24 forward speeds and 12 reverse speeds.
With the new design, a range shift is made every six shifts instead of every nine shifts, as would be provided in a modified version of the prior transmission. The six additional speeds then are useable to reduce the speed change between gear steps, reducing the required changes in the speeds of the rotating components during shifts. This decreases the time required for shift and allows smoother shifting.
Preferably, the transmission also provides direct engine power to an optionally engageable power take-off shaft, and modified power to a second output shaft, e.g., to drive the forward wheels of a four-wheel drive vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically illustrates the layout of FIGS. 1a, 1b and 1c, which collectively will be referred to hereinafter as "FIG. 1", and is a cross-section of a transmission according to the present invention.
FIG. 2 is a schematic representation of the transmission of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For clarity in the following description, reference numerals for shafts all begin with S, reference numerals for gears all begin with G and reference numerals for clutches all begin with C. For further clarity, the remainder of the reference numerals for a clutch and the corresponding gear are the same, e.g., clutch CR engages gear GR. Finally, remaining gears use nomenclature indicating upon which shaft they are mounted, e.g., gear G2 is mounted on shaft S2, and multiple gears mounted to a given shaft are indicated by alphabetic letters, e.g., gears G5A and G5B are both mounted to shaft S5.
Turning to FIG. 1, a housing 10 has a plurality of shafts, clutches, and gears rotatably mounted therein. Input shaft S1 is shown as having been made (for manufacturing convenience) in three parts S1A, S1B, S1C. These three parts are rotatably mounted in the housing 10 coaxially, and are fixed for rotation together by sleeves 12, 14. They will collectively be referred to hereinafter as shaft S1.
Shaft S1 has an input coupler 16 at one end thereof for receiving input motive power from a prime mover (not shown), e.g., a vehicle engine. Gear G1A is fixed for rotation with shaft S1.
Shaft S2 is rotatably mounted in the housing laterally adjacent to shaft S1, and has gear G2 fixed for rotation therewith. Shaft S2 also carries gears GL, GF2, which are rotatably mounted about shaft S2. Clutches CL, CF2 also are mounted around shaft S2 and can engage gears GL, GF2, respectively, to fix the gears for rotation with shaft S2. Gear GF2 continuously meshes with gear G1A.
Shaft S3 is rotatably mounted in housing 10 laterally adjacent to shafts S1, S2, and carries gear G3 fixed for rotation with shaft S3. Shaft S3 also carries gears GMA, GMB, GR which are rotatably mounted about the shaft S3. Gears GMA, GMB preferably are formed as a double gear, as shown. Shaft S3 further carries clutch CM, which can engage gears GMA, GMB, and clutch CR, which can engage gear GR, to fix them for rotation with shaft S3. Gears GR G3 GMA mesh continuously with gears G1A, G2, GL, respectively.
Shaft S4 is rotatably mounted in the housing 10 laterally adjacent to shafts S1, S3, and carries gear G4 fixed for rotation with the shaft S4. Shaft S4 also carries gears GH, GF1, which are rotatably mounted about shaft S4. Shaft S4 further carries clutches CH, CF1 which are engageable with gears GH, GF1, respectively, to fix the gears for rotation with the shaft S4. Gears GH, G4, GF1 mesh continuously with gears GMB, G3, G1A, respectively.
Shaft S5 is rotatably mounted in the housing 10 laterally adjacent to shaft S3, and carries gears G5A, G5B fixed for rotation therewith. Gear G5A meshes continuously with gear GMB.
Shaft S6 is rotatably mounted in the housing 10 laterally adjacent to shaft S5, and carries gear G6 fixed for rotation therewith. Shaft S6 also carries gear GD, which is rotatable about shaft S6. Clutch CD is mounted about shaft S6, and is engageable with gear GD to fix the gear for rotation with shaft S6. Gear GD meshes continuously with gear G5B.
Shaft S7 is rotatably mounted in the housing 10 laterally adjacent to shaft S6, and carries gear G7 fixed for rotation therewith. Gear GB is rotatably mounted about shaft S7. Clutch CB is carried by shaft S7 and is engageable with gear GB to fix the gear for rotation with the shaft S7. Gears GB, G7 mesh continuously with gears G6, GD, respectively.
Output shaft S8 is rotatably mounted in the housing 10 laterally adjacent to shaft S7, and carries gears G8B, G8C fixed for rotation therewith. Gear G8C preferably is a conical gear, and provides output motive power, e.g., by engaging the ring gear 18 of a differential for driving the wheels of the vehicle in which the transmission is used. Gear with GB.
Shaft S9 is rotatably mounted in the housing 10 laterally adjacent to shaft S8 and carries gear G9 fixed for rotation therewith. Gear GA is rotatably mounted about shaft S9. Clutch CA also is carried by shaft S9 and can engage gear GA to fix the gear for rotation with the shaft S9. Gear GA meshes continuously with gear G8B.
Shaft S10 is rotatably mounted in the housing 10 laterally adjacent to shafts S5, S9, and carries gears G10A, G10B fixed for rotation therewith. Gear GC also is rotatably mounted about shaft S10. Clutch CC is engageable with gear GC to fix the gear for rotation with shaft S10. Gears GC, G10B, G10A mesh continuously with gears GA, G9, G5B, respectively.
As will be apparent from the drawing, shafts S2, S3, S4 are of substantially the same size and configuration, and are positioned in a first group with their ends largely in common planes. Similarly, shafts S6, S7, S9, S10 are very similar in structure and are positioned in a second group largely with their ends in common planes. These groups of shafts then are positioned in longitudinally adjacent to each other, with the gears on shaft S5 serving to transmit power from one the gears in one group of shafts to the other.
A selectively engageable power take off (PTO) shaft may be provided, if desired. To do this, an additional gear G1B is fixed for rotation with the shaft S1. Shaft S11 is rotatably mounted in the housing 10 adjacent to the end of shaft S1 opposite from the input coupler 16. Gear GP is rotatably mounted about shaft S11. Shaft S11 also carries clutch CP, which is engageable with gear GP to fix the gear for rotation with shaft S11. Gear GP continuously meshes with gear G1B. Finally, the shaft S11 carries a PTO coupler 28 at one end thereof.
Similarly, an additional output shaft may be provided, e.g., for front wheel drive on a four-wheel drive vehicle. An additional gear G8A is fixed for rotation with shaft S8. Shaft S12 is positioned laterally adjacent to shaft S8. Gear G12 is mounted to shaft S12 by splines 20, which allow the gear to slide along shaft S12, but fix it for rotation with the shaft. Gear G12 is movable between a first position meshing with gear G8A and a second position disengaged from gear G8A. A shift mechanism 22, including the usual shift fork, cam rods, etc., is provided to move the gear G12 along the shaft S12, into and out of engagement with the gear G8C. Such shift mechanisms are well known to one of ordinary skill e.g., for providing power to the front wheels of a 4-wheel drive tractor.
Numerous bearings and oil passages for operating the various clutches are illustrated in the drawings. Such bearings and control mechanisms are well known to one of ordinary skill in the art, and have been omitted for clarity in many of the shafts. It is to be understood that they would be provided in the usual fashion.
FIG. 2 is a schematic representation of a transmission shown in FIG. 1. Due to the "unwrapping" all of the transmission in the cross-section taken in FIG. 1, not all of the gears are shown meshing with the gears with which they actually mesh. Any such situation is shown in the schematic by the use of dashed lines.
In a preferred embodiment, the gears shown in the drawing have the number of teeth on each gear shown in Table 1:
TABLE 1______________________________________ Tooth Gear Count______________________________________ GA 40 GB 40 GC 81 GD 40 GH 67 GMA 67 GMB 53 GL 53 GF1 54 GF2 48 GR 54 GP 71 G1A 39 G1B 22 G2 60 G3 60 G4 60 G5A 41 G5B 35 G6 81 G7 81 G8A 32 G8B 80 G9 81 G10A 81 G10B 40 G12 38______________________________________
OPERATION
It is believed that the method of operation of the present invention will be readily apparent to one of ordinary skill in the art from the foregoing description.
Generally, a range A, B, C, D is chosen by activation of one of clutches CA, CB, CC, CD. A direction and speed then is chosen by activating one of clutches CF1, CF2, CR and one of clutches CL, CM, CH. Various combinations of these activations can provide 24 forward speeds and 12 reverse speeds.
In particular, the clutches can be engaged as shown in Tables 2A and 2B. If gears having the teeth counts shown in Table 1 are used, the resulting gear ratios will be those shown in Tables 2A and 2B.
TABLE 2A__________________________________________________________________________Clutch activatedGear CA CB CC CD CH CM CL CF1 CF2 CR Ratio__________________________________________________________________________F1 X X X 12.691F2 X X X 11.281F3 X X X 10.039F4 X X X 8.924F5 X X X 7.942F6 X X X 7.059F7 X X X 6.267F8 X X X 5.571F9 X X X 4.958F10 X X X 4.407F11 X X X 3.922F12 X X X 3.486F13 X X X 3.095F14 X X X 2.751F15 X X X 2.448F16 X X X 2.176F17 X X X 1.937F18 X X X 1.722F19 X X X 1.528F20 X X X 1.359F21 X X X 1.209F22 X X X 1.075F23 X X X 0.956F24 X X X 0.850__________________________________________________________________________
TABLE 2B__________________________________________________________________________Clutch activatedGear CA CB CC CD CH CM CL CF1 CF2 CR Ratio__________________________________________________________________________R1 X X X -12.691R2 X X X -10.039R3 X X X -7.942R4 X X X -6.267R5 X X X -4.958R6 X X X -3.922R7 X X X -3.095R8 X X X -2.448R9 X X X -1.937R10 X X X -1.528R11 X X X -1.209R12 X X X -0.956__________________________________________________________________________
Various modifications may easily be made to the present invention by one of ordinary skill in the art. For example, if a PTO output is not desired, the entire portion 26 of the housing 10 containing shafts S1C, S11, clutch CP and gears G1B, GP may be omitted. Similarly, if front wheel drive is not desired, shaft S12 and its attendant components may be omitted. Alternatively, if permanent front wheel drive is desired, G12 can be fixed in a position engaging meshing continuously with gear G8A, and the shift mechanism 22 can be omitted.
While the invention has been described in conjunction with a specific embodiment, it is to be understood that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, this invention is intended to embrace all such alternatives, modifications and variations which fall within the spirit and scope of the appended claims. | The present invention provides a 24 forward speed, 12 reverse speed transmission for use in a work vehicle, e.g., an agricultural or industrial tractor. The transmission uses 10 clutches, with six arranged in a speed section and four in a range section. The speed section arrangement can provide six forward and three reverse speeds, while the range section can provide four ranges. Optionally, the transmission may be provided with a selectively engageable power take-off shaft and a selectively engageable front wheel drive take-off. The entire structure provides a very small speed change requirement between the diffrent gear ratios. | 5 |
BACKGROUND OF THE INVENTION
[0001] This invention involves the splicing together of high power electrical wires or cables, especially underground cables. There is no known device that can be used in splicing together the above noted cables, other than hand tools, because they are large in diameter and the outer layer is made of a plastic or rubber material that must be and remain water resistant for obvious reasons. Most all of the connections made are made by hand, especially when applying a connection sleeve over the wire splice once they have been made. The connection sleeve or housing has to have an extreme tight fit to be water proof. The only way to slide the connection sleeve or housing over the splice is by hand because any tools used can damage the outer circumference which is highly undesirable and may distort the cable or the housing out of round whereby the integrity of the water tight fit is violated. It takes extreme strong hands to accomplish the task of connection and it is very time consuming and labor intensive.
BRIEF DESCRIPTION OF THE INVENTION
[0002] The inventive device involves a power element such as a block and tackle. The cable to be connected to another cable receives a clamping block having interior friction mediums therein. The clamping block completely surrounds the outer circumference of the cable without distorting the same. The friction medium used inside the clamping block does not damage the outer material of the cable but is designed so as not to move relative to the cable when a pulling force is applied to the clamping block. The pulling force is derived from a block and tackle element. One end of the block and tackle element is located in a stationary manner while the other end of the block and tackle is movable, such as when attached to the clamping block. The cord of the block and tackle element is attached to a wind-up device. When the cord is wound up the force generated thereby exerts a moving force on the clamping block to effortless move the same in its designated path which will be explained below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 illustrates a first stage of making a splice;
[0004] FIGS. 1A-1D show different elements used in making electrical splices FIG. 2 is a representation of a second stage of making an electrical splice;
[0005] FIG. 3 is a final stage of making an electrical splice;
[0006] FIG. 4A shows a detailed illustration of a clamping block;
[0007] FIG. 4B shows clamping elements used in a clamping block;
[0008] FIG. 4C shows the clamping block of FIG. 4A in an open position;
[0009] FIG. 4D illustrates retaining pins for a spool shown in FIG. 4A ;
[0010] FIG. 4E shows a spool for a wind-up of a block and tackle;
[0011] FIG. 4F illustrates a clamping block being hinged in a diagonal manner;
[0012] FIG. 4G shows the clamping block of FIG. 4F in an open position;
[0013] FIG. 5 illustrates a first stage of attaching a permanent adapter to a cable;
[0014] FIG. 5A illustrates a retaining block used in various applications;
[0015] FIG. 6 illustrates a static bar;
[0016] FIG. 7 shows a flexible sling used when making a T-connection;
[0017] FIG. 8 is a permanent adapter used when making certain connections;
[0018] FIG. 9 is a pull-on plate used when making T-connections;
[0019] FIG. 10 is a cable protector and an alignment tool;
[0020] FIG. 11 shows a pull-through rod for a clamping block;
[0021] FIG. 11A shows a pull-through rod with a an expandable cable connector;
[0022] FIG. 12 is a system for making a T-shaped connection;
[0023] FIG. 13 shows a system for installing a splice housing with a different pull back collar;
[0024] FIG. 13A shows the pull back collar by itself;
[0025] FIG. 14 shows another and different pull-back collar;
[0026] FIG. 14A shows a friction insert for the pull-back collar of FIG. 14 ;
[0027] FIG. 15 shows a system for installing a splice housing including the pull-back collar of FIG. 14 ;
[0028] FIG. 15A is a different embodiment of creating friction between a housing and pull-back collar;
[0029] FIG. 16 illustrates a first stage of making a Y-connection;
[0030] FIG. 17 shows the second stage of making the Y-connection of FIG. 16
[0031] FIG. 18 illustrates a support post to simplify installations.
DETAILED DESCRIPTION OF THE INVENTION
[0032] FIG. 1 illustrates a first stage of the process when splicing an electrical underground cable. The reason there are several stages is the fact that various pulling forces on the elements of the splice occur in different or opposite directions. In this first stage there is a stationary block 1 and there is a stationary clamping block 2 . The reason why these blocks are stationary is that various elements that make up the splice have to move independently of the cable that is clamped or will be by the clamping block 2 . Both the clamping block and the stationary block are held in their position by the static rods 3 . The static block 1 is shown in more detail below in FIG. 1C . The static rods 3 are shown in more detail in FIGS. 1A and 1B below. The static block 1 consists of pegs 6 which can and will receive at least one end of the static bar 3 in FIG. 1 . The pegs 6 can be threaded or be smooth depending of n the manufacturer. The clamping block 2 is made up of two halves 10 and 11 ( FIG. 4A ) which are connected by a hinge 12 ( FIGS. 4A and 4C ). The clamping block 2 carries at an upper end thereof a wind-up spool 21 which will wind-up cords of a block and tackle system 7 (which will be explained in more detail below. The wind-up spool is held in place in its cradle by retaining pins 24 and 25 . Prior to making a connection between a cable and the block and tackle, the system has to be threaded by way of a threading tool 16 which passes through a splice housing 31 , a temporary adapter 30 and through the center of the clamping block 2 and then on to a connection 41 on the block and tackle 7 . The spool 21 has a wind-up stem 22 which can be connected to a socket of a ratchet tool or an electric appliance (not shown). One end 40 of the threading tool 26 is connected to the receiving eyelet 41 of the block and tackle element 7 . The threading tool 26 includes an expanding screw connector which will be received within the compression connection 42 . The connector also includes the crimped ends 34 of the bare cable 43 .
[0033] FIG. 2 illustrates the second stage of making an electrical splice in an underground cable. In this illustration it can be seen that the block an tackle 7 ( FIG. 1 ) has pulled the cable including the splice housing 31 into the clamping block 2 including the temporary adapter 30 ( FIG. 1 ) into a proper concentric position. At this point the crimped end 34 of the incoming cable including a compression connection is ready for receiving a housing 31 .
[0034] FIG. 3 illustrates the reverse movement of the block and tackle. In this third stage of making a splice, the clamping block 2 is stationarily supported on an outgoing cable assembly. There is a gripping adapter 44 which frictionally grips the cable at that point. There is a counter stationary block 1 (also shown in FIG. 5A ) which acts as a counter force to the clamping block 2 because of the presence of the static bars 3 . The object of this third splicing stage is to apply the splice housing 31 over the previously crimped ends 34 and 35 which are covered by a compression connection. To this end, the housing 31 is pulled over the splices 34 and 35 by way of a pulling collar 32 (also shown in FIG. 13A ). The pulling collar 32 abuts against a ridge (not shown) on the housing 31 . In this pulling stage, there is a dual block and tackle wherein the ends of the cords are threaded into the spool 21 . The other ends of the cords are attached to attachment hooks 33 on the pulling collar 32 . The return ends of the block and tackle are attached at 5 a and 5 b on the stationary block 1 . Also see FIG. 5A .
[0035] FIG. 4A is a detailed illustration of the clamping block 2 shown in FIG. 1 The basic clamping block has been identified as 2 ( FIG. 1 ). The clamping block 2 consists of two halves 10 and 11 which are hinged together by a hinge 12 . The two halves 10 and 11 are clamped together by way of a compression clamp 13 . There are two eyelet hooks 20 which receive the ends of a cord coming from the block and tackle elements. The clamping block 2 also has a winding spool 21 mounted therein for the purpose of winding the ends of the cords coming from the block and tackle elements. The ends of the rewinding spool 21 are held in place by retaining pins 24 and 25 . The end 22 of the spool is designed to receive a pair of pliers, a wrench or a socket of a ratchet handle in order to wind the same. Turning now to FIG. 4B , there is shown to halves 14 and 15 of friction elements that are installed within each halve of the clamping block. Each of the halves 14 and 15 have a holding pin 18 attached thereto to penetrate each of the halves 14 and 15 and to be securely held in place by outside lock nuts 19 . The inside of each of the halves has ribs 16 made therein to act as gripping surfaces so that the clamping block can grip the outer surface of a cable to be pulled. Other friction surfaces could be used such as layers of sandpaper. FIG. 4A also shows eyelets 20 which are used to anchor each end of the block and tackle cords therein. The clamping segments 14 and 15 each have a central and outer centering ridge thereon to be received in a groove 17 a in each of the clamping halves 10 and 11 .
[0036] FIG. 4C shows the clamping block 2 of FIG. 4A in an open position. The same reference characters are being used as were shown in 4 A. No further explanation of this Fig. seems to be necessary. FIG. 4C also illustrates the wind-up spool 21 which has flanges 23 thereon and at one end thereof shows an attachment for a tool such as a socket of a ratchet handle.
[0037] FIG. 4D illustrates the retaining pins 24 and 25 .
[0038] FIG. 4E illustrates a friction insert 16 that is to inserted into the clamping halves 14 and 15 which are located in the clamping block 2 ( FIGS. 1, 2 and 4 A). The ridge 17 is clearly shown which will be received in the groove 17 a ( FIG. 4C ) to stabilize the same. The retaining pin 18 can also be seen which is held in place by the lock nut 19 in FIG. 4A . As explained above, the friction insert 16 has friction ribs therein to securely grip the outer circumference of a cable being operated on.
[0039] FIG. 4F illustrates the clamping block 2 of FIG. 1 including the same reference characters but this illustration depicts the clamping block being split on the diagonal instead of being split in half from a square block. This arrangement has a big advantage in that the wind-up spool 21 does not have to be removed from the clamping block every time when the clamping block of FIG. 1 is being opened for inserting a cable therein. FIG. 4G has been opened and it can be seen that the wind-up spool 21 is still in place.
[0040] FIG. 5 illustrates a different embodiment in that it shows the first stage of attaching or installing a T-shaped connector ( FIG. 12 ). This embodiment includes the clamping block 2 including the various elements and reference characters of FIG. 1 but further showing a dual block and tackle mechanism 60 . The incoming cable has an outer insulation which is clamped within the clamping block 2 ( FIG. 1 ). The dual block and tackle mechanism is attached at one end on the eyelets 20 on the clamping block and at another end to the wind-up spool 21 . There is a permanent adapter 50 , having different steps 50 a and 50 b thereon, being slid over the end of the insulation on the cable 61 . This permanent adapter will be supplied in different sizes to accommodate differently sized cables. Each end of the dual block and tackle is attached to an eyelet 20 on the clamping block 2 and the other ends are attached to the wind-up spool 21 . The two intermediate sections of the dual block and tackle are each attached to an eyelet (only 52 is shown) which are fastened to a pulling plate 52 . It can be seen that when the wind-up spool 21 is activated by rotating the end 22 , the dual block and tackle 60 will pull the pulling plate 52 against the adapter and force the same over the existing cable 61 .
[0041] FIG. 5A shows the static block 1 of FIG. 3 in more detail. There are two eyelets 5 a which will each receive the intermediate ends of the block and tackle 7 ( FIG. 1 ). There are also two pins 5 a which receive the ends of the static rods 3 ( FIGS. 1-3 and 6 ) to stabilize the clamping block 2 and the stationary block 1 when the system is in operation.
[0042] FIG. 7 illustrates a skirt 51 which will be wrapped around a T-shaped tubing 65 as will be explained below with regard to FIG. 12 . The eyelets 51 a and 51 b will receive the intermediate sections of the block and tackle 60 ( FIG. 12 ).
[0043] FIG. 8 shows the permanent adapter 50 of FIG. 5 in more detail in that there are shown the various steps 50 a and 50 b to be received over the differently sized outer cable circumferences that can be spliced using the inventive system.
[0044] FIG. 9 illustrates the pulling plate 52 of FIG. 5 including the eyelets 52 a and 52 b.
[0045] FIG. 10 appears to be a simple length of tubing, however, it is a wire protector and an alignment guide for the adapter shown in FIG. 5 .
[0046] FIG. 11 illustrates a different pulling tool 26 useful for pulling the block and tackle through the various elements as is shown in FIG. 1 . The same reference characters have been used in this Fig. This tool is a simplified version of the pulling tool 26 in FIG. 1 . The hook 26 a will receive the intermediate section 41 of the block and tackle and the handle 26 b will be used to pull the rigid rod 26 through the various elements in a similar manner that the hook 40 ( FIG. 1 ) will pull the block and tackle 41 through the same various elements.
[0047] FIG. 12 illustrates the attachment of a T-shaped tubing to an incoming cable. These T-shaped elements are used when heavy duty underground cables are connected within electrical distribution cabinets. To connect the T-shaped tubing to a splice within the T-shaped tubing. the same inventive elements are being used, that is, the block and tackle power system. FIG. 12 shows the same reference characters that were used in previous Figs. In this illustration, the pulling skirt can clearly be seen at 51 as being wrapped around the T-shaped tubing 65 . The intermediate sections 52 a and 52 b ( FIG. 5 ) of the block and tackle system are received in the eyelets 51 a and 51 b ( FIG. 7 ). Thus, it can be seen that when the forces of the dual block and tackle system are activated, The T-shaped tubing 65 will be pulled and forced over the adapter 50 until firmly seated against the cable outer periphery.
[0048] FIG. 13 is a different embodiment of a pulling element in a simplified version. It consists of a three quarter ring which can be slipped over an adapter 74 in FIG. 15 . The dual block and tackle 72 and 73 can be attached to the hooks 79 a and 79 b.
[0049] FIG. 14A illustrates a different embodiment of a pulling housing or block 81 over finished splices 75 in FIGS. 15 and 15 A. In this embodiment there is the clamping block with its hinge 12 which is clamped over an adapter 74 which may consist of different sizes depending on the size of the cable being spliced. This embodiment is similar to the one shown in FIG. 3 . The static block 1 ( FIG. 1 ) has been modified to appear in a semi-circular configuration 70 . This particular embodiment includes the static bars 71 located between the clamping block (illustrated by the presence of the hinge 12 and the static block 70 . The pulling force to be applied to moving the housing 74 to be moved over the splicing 75 , 76 is received from the force of the block and tackle 72 , 73 . The block and tackle system is attached to a pull-back collar 79 ( FIG. 13 ). The pull-back collar abuts against a rib on the housing 74 . The pull-back collar 79 has attached thereto eyelet hooks 79 a and 79 b which will receive the intermediate sections of the block and tackle system 72 , 73 . It can now be seen that, when the block and tackle system is activated, the pull-back collar 79 will be pulled against a rib on the housing 74 and will be forced over the splice 75 , 76 and will completely and hermetically seal the spliced cable.
[0050] FIG. 14 illustrates a different embodiment of a pulling collar or a clamping block. To this end, the pulling collar 81 consists of two halves which are hingedly connected to each other by way of a hinge 12 ( FIGS. 1-3 ) and connected together by way of a connector 82 . The interior of both halves have a centering ridge 85 . The interior of the clamping block 81 will receive friction elements 87 which have a friction surface 89 thereon. The outer circumferences of the friction elements 87 have a retention groove 88 therein which is designed to match the centering ridges 85 of the halves of the pulling collar. The pulling collar 81 further has attached thereto pull eyelets 86 for attaching intermediate sections of the block and tackle ( FIG. 15 ).
[0051] FIG. 15 shows the pulling collar 81 installed in a system for moving the housing 74 over the splice 75 , 76 . The pulling collar 81 abuts against a ridge on the housing 81 .
[0052] FIG. 15A shows yet a different pulling collar 81 which is adapted to accommodate different sizes of cables. To this end, the pulling collar has carriage bolts 120 installed therein by way of threaded connections. The heads of the carriage bolts 120 being placed inwardly of the pulling collar 81 . The size of the depressions 82 can change because of a different cable size being operated upon, but the effect of the pulling collar can only be changed by changing the position (inwardly or outwardly) of the carriage bolts 120 that make contact with the depressions 82 ( FIG. 15 ) in the housing 74 .
[0053] FIG. 16 illustrates a different embodiment of splicing a heavy duty cable in different formations such as Y, T or H-shaped formations. FIG. 16 illustrates a connection involving a Y-shaped formation. In this illustration, there is a first electric branch 96 being connected to a second electric branch 95 . A third electric branch 98 is to be spliced into a permanent electric connector 95 . The splicing itself will be undertaken again by a block and tackle system which again, as explained above, will involve a stationary static block 1 and a clamping block 99 similar to the clamping block 2 in FIG. 1 . The block and tackle block 100 is a dual system that will connect to both sides of the splice housing, similar to splicing systems of FIGS. 12 and 13 . FIG. 16 shows the initial set-up prior to activating the block and tackle system and FIG. 17 illustrates the final system wherein the housing 103 has arrived at the final connection position.
[0054] FIG. 18 illustrates a support device to be used when making the above noted splices in the various embodiments. The support device consists of an upstanding rod or stand 110 which can be driven into the ground wherever underground splices are to be made. This driving into the ground can involve the foot steps 111 . The upper section of the rod 110 includes a section 113 having an upper pin 114 that can be connected to the clamping block 2 in FIG. 1 by way of a bore in the bottom of the clamping block 2 and the lowest section 115 can be driven into the ground. The upstanding 110 rod further can include hooks 112 or shelves for receiving items needed in the splicing of the various cables, although very few items or tools are needed when making the above noted splices.
[0055] From all of the above, it can be seen that an inventive splicing system has been presented that takes the labor intensive effort out of the manual drudgery of making splices in the splicing of underground cable, no matter what sizes they are. | A system for splicing together heavy duty electric cables, especially underground cables, consisting of a static friction block and a clamping friction block located on ends of cables to be spliced. A block and tackle mechanism is interposed between the friction block and the clamping block to provide a force to move various elements on the cables to various and final predetermined locations to make up the splice. The block and tackle mechanism has a wind-up spool thereon to wind-up ends of cords of the block and tackle mechanism. The wind-up spool provides the necessary force to accomplish the move of the various elements. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a process for preparing organozinc halides (halogen-zinc compounds, Reformatsky reagents) from reactive halogen compounds and to their use in preparing keto, hydroxyl and amino compounds in carboxylic esters.
[0003] 2. The Prior Art
[0004] The reaction of reactive halogen compounds, in particular of α-halocarbonyl compounds, with electrophilic substrates, for example aldehydes, ketones, imines, nitriles, carboxylic anhydrides, carboxylic chlorides, lactones, orthoformates, formates, epoxides, azirines, aminals and nitrones, in the presence of zinc metal, is known as the Reformatsky reaction. This reaction produces important synthetic building blocks for preparing active pharmaceutical ingredients, scents and crop protecting agents.
[0005] The choice of the solvent and the activation of the zinc used or of the entire reaction mixture are of decisive importance for the achievement of good yields and high selectivities and therefore good product purities.
[0006] It is known that particularly useful solvents for the Reformatsky reaction include ethers such as diethyl ether, 1,4-dioxane, dimethoxymethane, dimethoxyethane and in particular tetrahydrofuran. In addition, further solvents which have proven useful include aromatic hydrocarbons or mixtures of the abovementioned ethers with aromatic hydrocarbons, the mixture of tetrahydrofuran with trimethyl borate, and the polar solvents acetonitrile, dimethylformamide, dimethyl-acetamide, dimethyl sulfoxide and hexamethyl-phosphoramide. A review on this subject is contained, for example, in A. Fürstner, Synthesis 1989, pp. 571-590.
[0007] EP-A-562 343 discloses that the reaction of α-bromocarboxylic esters with carbonyl compounds in the presence of zinc in the solvent methylene chloride proceeds with high yields.
[0008] The use of the solvents and solvent mixtures mentioned has the following disadvantages:
[0009] the water-miscible ethers 1,4-dioxane and tetrahydrofuran and also the water-miscible polar solvents acetonitrile, dimethylformamide, dimethylacetamide, dimethyl sulfoxide and hexamethylphosphoramide dissolve in the aqueous phase on aqueous workup to hydrolyze the zinc compounds and zinc salts formed. Particularly when applied on the industrial scale, it is necessary, for economic reasons and to reduce the amounts of waste, and to recover the solvents used from the aqueous phase. This recovery may be done for example by extraction or distillation, which is, however, associated with considerable cost and inconvenience.
[0010] In addition, when the abovementioned water-miscible solvents are used in the hydrolysis of the reaction mixture, it is customarily necessary to use water-immiscible organic solvents such as ethyl acetate or methyl tert-butyl ether as cosolvents for better phase separation. These solvents have to be recovered and, before reuse, freed of impurities by distillation, which is likewise associated with high cost and inconvenience. When solvent mixtures are used for Reformatsky reactions, the recovery, separation and any purification of the individual solvents used generally entails even more considerable cost and inconvenience.
[0011] Furthermore, when diethyl ether, 1,4-dioxane, dimethoxymethane, dimethoxyethane and tetrahydrofuran are used as solvents for Reformatsky reactions, they tend to form explosive peroxides by autoxidation. This makes their use on the industrial scale dangerous, in particular on repeated use after recovery (danger of accumulation of the explosive components). Or it makes their use more difficult or possible only at great cost and inconvenience.
[0012] The use of methylene chloride as solvent, as disclosed by EP-A-562 343, or of other halogenated hydrocarbons as solvents is objectionable for environmental reasons. Accordingly it is to be avoided, on the industrial scale in particular. In addition, many of the abovementioned solvents are expensive which additionally compromises the economic viability of the reaction without recovery of the solvent used.
[0013] SU 472127 discloses the reaction of α-bromoketones and zinc with nitriles in ethyl acetate as solvent for preparing β-iminoketones. The zinc to be activated in ethyl acetate is added to a mixture of bromoketone and nitrile. A mixture of bromoketone (reactive halogen compound) and nitrile (electrophilic substrate) is added to activated zinc, and the organozinc halide formed (Reformatsky reagent) reacts immediately with the substrate. For many substrates, the addition of a mixture of reactive halogen compound and electrophilic substrate described in SU 472127 is highly disadvantageous.
[0014] Certain substrates which have further functional groups, for example amino or epoxide functionalities, react as soon as they are combined with the reactive halogen compound (for example α-haloester, α-bromoketone). They form undesired by-products before the actual contact with the zinc takes place. For instance, those skilled in the art are familiar with the reaction of amines or epoxides with reactive halogen compounds, for example from X. -P. Gu, I. Ikeda, M. Okahara, Bull. Chem. Soc. Jpn., 1987, 60, pp. 397-398. The process described is accordingly unsuitable for such substrates.
SUMMARY OF THE INVENTION
[0015] It is an object of the present invention to provide a process which solves the problems known from the prior art.
[0016] The present invention provides a process for preparing organozinc halides in solvents, which comprises reacting a reactive halogen compound with zinc in one or more carboxylic esters.
[0017] In a preferred embodiment of the invention, the process according to the invention is used to prepare organozinc halides of the general formula (4)
HalZn—R 3 R 4 C—(X) 1 —Y (4)
[0018] by reacting reactive halogen compounds of the general formula (2)
Hal-R 3 R 4 C—(X) 1 —Y (2)
[0019] with zinc, where
[0020] R 1 and R 2 are each hydrogen or an optionally halogen- or cyano-substituted C 1 -C 30 -hydrocarbon radical in which one or more nonadjacent methylene units may be replaced by —O—, —CO—, —COO—, —OCO—, or —OCOO—, —S— or —NR x — groups and in which one or more methine units may be replaced by —N═ or —P═ groups,
[0021] R 3 , R 4 , R 5 , R 6 and R 7 are each hydrogen, halogen or an optionally halogen-substituted or cyano-substituted C 1 -C 30 -hydrocarbon radical in which one or more nonadjacent methylene units may be replaced by —O—, —CO—, —COO—, —OCO—, or —OCOO—, —S— or —NR x — groups and in which one or more methine units may be replaced by —N═ or —P═ groups,
[0022] X is selected from
[0023] l is an integer having the value 0 or 1,
[0024] Y is CN, (C═O)-Z, (SO 2 )-Z, (P═O) (-Z) 2 , R 5 C═CR 6 R 7 , C≡C-R 5 or an aromatic radical in which one or more methine units in the ring may be replaced by —N═ or —P═ groups and which may carry the heteroatoms —O—, —S— or —NH— in the ring, where the aromatic ring is optionally halogen- or cyano-substituted or is substituted by C 1 -C 30 -hydrocarbon radicals in which one or more nonadjacent methylene units may be replaced by —O—, —CO—, —COO—, —OCO—, or —OCOO—, —S— or —NR x — groups,
[0025] Z is an optionally halogen-substituted C 1 -C 30 - hydrocarbon radical in which one or more nonadjacent methylene units may be replaced by —O—, —CO—, —COO—, —OCO—, —OCOO—, —S— or —NR x — groups and in which one or more methine units may be replaced by —N═ or —P═ groups, OH, OR 1 , OSi(R 3 ) 3 , NHR 1 or NR 1 R 2 ,
[0026] Hal is chlorine, bromine or iodine,
[0027] R x is hydrogen or an optionally halogen-substituted C 1 -C 30 -hydrocarbon radical in which one or more nonadjacent methylene units may be replaced by —O—, —CO—, —COO—, —OCO—, or —OCOO—, —S—, —NH— or —N—C 1 -C 20 -alkyl groups and in which one or more methine units may be replaced by —N═ or —P═ groups, and
[0028] pairs of radicals selected from R 1 and R 2 , R 3 and R 4 , R 4 and R 5 , R 5 and R 6 , R 6 and R 7 , R 1 and R 3 , R 1 and Y, R 1 and Z, R 3 and Y, R 3 and Z, R 5 and Y, R 5 and Z, where Z may be a direct bond, may each be linked to each other.
[0029] The invention further provides the use for preparing keto, hydroxyl and amino compounds of organozinc halides obtained in a first step from a reactive halogen compound and zinc in one or more carboxylic esters, wherein the organozinc halide obtained is reacted in a second step with an electrophilic reaction partner and the reaction product of the second step is hydrolyzed in a third step.
[0030] Preference is given to using the process according to the invention for preparing keto, hydroxyl and amino compounds of the general formula (1)
R 1 (R 2 ) k C(W x )—R 3 R 4 C—(X) 1 —Y (1)
[0031] wherein the electrophilic reaction partner used in the second step is an aldehyde, ketone or imine of the general formula (5a)
R 1 R 2 C═W (5a)
[0032] or an epoxide of the general formula (5b)
[0033] [0033]
[0034] or a nitrile of the general formula (5c)
R 1 C≡N (5c)
[0035] or a carboxylic halide of the general formula (5d)
R 1 (C═O)-Hal (5d)
[0036] where
[0037] W x is OH, NHR 1 or ═O and
[0038] W is O or NR 1 ,
[0039] k, when W x is OH and NHR 1 , should have the value 1 and, when W x is ═O, should have the value 0, and
[0040] the remaining radicals are defined above and in addition pairs of 2 radicals selected from R 1 and R 2 , R 3 and R 4 , R 4 and R 5 , R 5 and R 6 , R 6 and R 7 , R 1 and R 3 , R 1 and Y, R 1 and Z, R 3 and Y, R 3 and Z, R 5 and Y, R 5 and Z, W x and Y and also W x and Z, where W x is O— or NR 1 — and Z may be a direct bond, may each be linked to each other.
[0041] The invention further provides solutions of organozinc halides in carboxylic esters which are prepared by the process according to the invention.
[0042] It has surprisingly been found that carboxylic esters are on the one hand suitable solvents for preparing organozinc halides (Reformatsky reagents) from reactive halogen compounds and zinc.
[0043] Furthermore, carboxylic esters are also outstandingly suitable for further reactions of the halogen-zinc compounds with electrophilic substrates (Reformatsky reaction), in particular with aldehydes, ketones, imines, nitriles, carboxylic halides and epoxides, and also for the subsequent hydrolysis of the reaction products obtained in this way in a further reaction step.
[0044] In this way, keto, hydroxyl and amino compounds in particular can be prepared.
[0045] The use of carboxylic esters as solvents makes it possible to carry out the reaction on the industrial scale in particular without the addition of further solvents or cosolvents or the use of solvent mixtures. The reaction occurs with high yields and selectivities while at the same time allowing simple recovery of the solvent used. As a consequence the reaction occurs in an environmentally friendly and cost-effective manner, since the amounts of waste can be markedly reduced.
[0046] The Reformatsky reagents prepared by the process according to the invention in the form of organozinc halides dissolved in carboxylic esters are surprisingly stable as reactive organometallic intermediates over long periods even at relatively high temperatures. They may be reacted further immediately or not until a later time in subsequent reaction steps, in particular with electrophilic substrates.
[0047] The Reformatsky reagents prepared by the process according to the invention in the form of organozinc halides dissolved in carboxylic esters therefore constitute reaction-ready solutions. They are universally usable starting compounds for reactions with electrophiles, in particular for Reformatsky reactions.
[0048] The above-described process according to the invention allows keto, hydroxyl and amino compounds of the general formula (1) to be obtained in very high yields of up to >90% and very high purities in a simple manner and at simultaneously very good space-time yields.
[0049] The process according to the invention is simple to perform, particularly on the industrial scale. This is because the reaction may be carried out in the commercially obtainable carboxylic esters of the general formula (3) as solvents without pretreatment of these solvents, for example distillation or drying, being necessary.
[0050] The subsequent reaction steps in the form of further reactions with electrophiles, in particular of Reformatsky reactions, do not require the addition of a further solvent. For example, it is not necessary to add a cosolvent for better phase separation in the workup, either for carrying out the reaction or for the workup. Since no solvent mixtures have to be added, the solvents used can be recovered very simply. The carboxylic esters of the general formula (3) which are preferably used are only slightly or very sparingly soluble in water. Therefore they can be easily and efficiently recovered, for example in the product isolation, which makes the reaction very economical. For example, when ethyl acetate, isopropyl acetate or butyl acetate are used as the solvent of the general formula (3), they can be recovered in very high yields when the products prepared are isolated by distillation.
[0051] The processes according to the invention additionally facilitate the replacement of halogenated hydrocarbons and ethers prone to peroxide formation by carboxylic esters of the general formula (3) as the solvent. This not only makes the processes according to the invention more environmentally friendly but also markedly reduces the danger potential.
[0052] Furthermore, in many cases, the product yield and quality of the keto, hydroxyl and amino compounds of the general formula (1) prepared according to the process variant according to the invention are improved compared to the existing variants described in the literature. The use of carboxylic esters of the general formula (3) is particularly advantageous for the progress of the reaction, the product yields and purities and the elimination of secondary reactions.
[0053] In addition, the processes according to the invention may be performed in most cases with a slight excess of zinc and reactive halogen compound of the general formula (2), based on the electrophilic reaction partner. This results in many cases in higher product yields and qualities than in existing variants using the previously known solvents mentioned. This makes the process according to the invention particularly economical.
[0054] Furthermore, the process according to the invention advantageously also makes it possible to react electrophilic substrates which have nucleophilic functional groups (for example amino groups) or nucleophilic properties (for example epoxides). They can be reacted with the reactive halogen compound while forming undesired by-products even before contact with the zinc. The organozinc halide prepared in the first reaction step of the process according to the invention from reactive halogen compound and zinc is reacted in the second reaction step with the substrates (for example epoxides or substrates having amino groups) in high yields and high purities to be changed into the desired products (See Example 5).
[0055] In addition, it is possible for the organozinc halides prepared in the first step of the process according to the invention to be reacted with the electrophiles in a second step under mild conditions at low temperature to obtain high yields and in particular high purities. This allows electrophilic reaction partners, for example epoxides, which are particularly sensitive and unstable at relatively high temperatures as are required for preparing the organozinc halides in the first step to be reacted with high yields and product purities. In contrast, when a mixture of bromoacetic ester and styrene oxide is reacted with zinc at an elevated temperature of 55-65° C., as described in SU 472127, the drastic reaction conditions result in decomposition of the reaction mixture to form undesired by-products (See Comparative Example 7).
[0056] Also, the organozinc halides prepared in the first reaction step can initially be stored stably or intermediately stored before reaction with the electrophilic reaction partner. This is advantageous in particular in industrial implementation, since this allows industrial production processes to be configured optimally in terms of time, personnel and capacity, and to be run in parallel. This which makes the process according to the invention particularly economical in particular when carried out on the industrial scale.
[0057] The C 1 -C 30 -hydrocarbon radicals for R 1 , R 2 , R 3 , R 4 , R 5 and Z are preferably linear, branched or cyclic C 1 -C 20 -alkyl, C 3 -C 20 -alkoxycarbonylalkyl, C 2 -C 20 -alkenyl, C 5 -C 20 -acetalalkenyl or C 3 -C 20 -alkoxycarbonylalkyl radicals, each of which may be substituted by F, Cl, Br, I, CN or C 1 -C 8 -alkoxy radicals; aryl, aralkyl, alkaryl, aralkenyl or alkenylaryl radicals in which one or more methine units may be replaced by —N═ or —P═ groups and methylene units by —O—, —S— or —NH—, each of which may be substituted by F, Cl, Br, I, CN, C 1 -C 10 -alkoxy radicals or C 1 -C 20 -alkylamino radicals and, on the ring, by C 1 -C 10 -alkyl radicals and may carry the heteroatoms —O—, —S— or —NH— in the ring.
[0058] The radicals R 1 and R 2 , R 3 and R 4 , R 4 and R 5 , R 5 and R 6 , R 6 and R 7 , R 1 and R 3 , R 1 and Y, R 1 and Z, R 3 and Y, R 3 and Z, R 5 and Y, R 5 and Z, W x and Y, and W x and Z, where W x is O— or NR 1 — and Z may be a direct bond, may be linked to each other. The radicals R 1 and R 3 , R 1 and Y, R 1 and Z, W x and Y, and W x and Z, where W x is O— or NR 1 — and Z may be a direct bond, may be linked to each other by intramolecular reaction.
[0059] The halogen radicals R 3 , R 4 , R 5 , R 6 and R 7 are preferably F and Cl.
[0060] In particular, l has the value 0.
[0061] The reactive halogen compounds of the general formula (2) used are preferably bromine compounds, where Hal in the general formula (2) is bromine. Preference is given to reactive halogen compounds of the general formula (2) in which Y is (C═O)-Z. Preference is further given to reactive halogen compounds of the general formula (2) in which Z is OR 1 . In particular, preference is given to α-bromocarboxylic esters as the reactive halogen compounds of the general formula (2).
[0062] In the use according to the invention of organozinc halides in a process for preparing keto, hydroxyl and amino compounds, preference is given to initially charging the zinc in the carboxylic ester of the general formula (3) in a first step and then adding the reactive halogen compounds of the general formula (2), optionally dissolved in a solvent.
[0063] In a second step, suitable electrophilic substrates, preferably aldehydes, ketones, imines, epoxides, nitriles and carboxylic halides of the general formulae (5a) to (5d), optionally dissolved in a solvent, are added to the solution of the organozinc halides of the general formula (4) obtained in the first step.
[0064] Preference is likewise given to adding the solution of the organozinc halides of the general formula (4) obtained in the first step to suitable electrophilic substrates. These substrates are preferably aldehydes, ketones, imines, epoxides, nitriles and carboxylic halides of the general formulae (5a) to (5d), optionally dissolved in a solvent, in a second step.
[0065] A. Fürstner, Synthesis 1989, pp. 571-590 and K. Nützel in Houben - Weyl, Methoden der organischen Chemie, 4th edition, Vol. XIII/2a, Stuttgart 1973, pp. 828-832 disclose that α-bromozinc esters (Reformatsky reagents) of the general formula (4) can react with certain reactive carboxylic esters, viz. cyclic carboxylic esters (lactones), formic esters, orthoformic esters and benzoic esters. Reactive carboxylic esters other than those mentioned above are not reactive toward α-bromozinc esters. In exceptional cases, a reaction does take place either when coordinating or polar solvents (for example 1,4-dioxane or dimethyl sulfoxide) are used or when the reaction times are long and temperatures are high at the same time.
[0066] Surprisingly, the organozinc halides (Reformatsky reagents) of the general formula (4) prepared by the process according to the invention are sufficiently stable and storable (see examples) in the carboxylic esters of the general formula (3). These esters can be used as solvent in the process according to the invention even at elevated temperatures. They can be converted directly to keto, hydroxyl or amino compounds in subsequent reaction steps by reaction with electrophilic substrates and hydrolysis, which would not have been expected on the basis of the teachings of the prior art.
[0067] During the preparation of the organozinc halides by the process according to the invention, the temperature of the exothermic reaction is generally maintained at a predetermined value, if necessary by cooling. The upper temperature limit may be defined by the boiling point of the solvent of the general formula (3) used, for example ethyl acetate (b.p.: 77° C.) or isopropyl acetate (b.p.: 87-89° C.). In the case of higher-boiling solvents of the general formula (3), for example n-butyl acetate (b.p.: 124-126° C.), preference is given to controlling the temperature of the reaction by cooling. Preference is given to carrying out the reaction at temperatures of from −20 to +150° C., more preferably from 20 to 110° C., in particular from 40 to 90° C.
[0068] Zinc is generally used in the form of sheets, ribbon, turnings, powder or dust, or in the form of zinc wool. The presence of other metals such as copper, silver or mercury is not necessary. In particular, zinc is used in the form of commercially obtainable, commercially customary zinc powder or zinc dust. Preference is given to zinc of high purity of at least 99.995%, greater preference to zinc dust which is obtained from zinc having a purity of at least 99.995%.
[0069] To achieve high product yields, it has generally proven advantageous to activate the zinc before addition of the reactive halogen compound of the general formula (2). For zinc activation, existing methods which are customarily used and mentioned, for example, in the review of A Fürstner, Synthesis 1989, pp. 571-590, are suitable. Particularly advantageous methods have proven to be washing of the zinc with acid, activation by iodine, as described in EP-A-562 343, and the activation by trimethylchlorosilane. Particular preference is given to the activation by trimethylchlorosilane due to its ease of performance and the increased yields, product purities and selectivities, and also the suppression of secondary reactions. G. Picotin, P. Miginiac, J. Org. Chem. 1987, 52, p. 4796 disclose the activation of zinc by trimethylchlorosilane in the solvent diethyl ether.
[0070] To activate zinc using trimethylchlorosilane, the zinc is initially charged in the carboxylic ester of the general formula (3), then trimethylchlorosilane is added and the mixture is heated for from 10 min to 2 h, preferably from 10 to 45 min, at temperatures of from 30 to 150° C., in particular from 40 to 120° C., more preferably from 50 to 90° C. It has proven advantageous to react the zinc with trimethylchlorosilane in a molar ratio of 1:(0.005 to 0.5), in particular 1:(0.03 to 0.3) in the carboxylic ester of the general formula (3) with heating to the desired temperature.
[0071] For activation of the reaction mixture, it is also possible to add additives such as compounds of copper, chromium, manganese, cobalt, bismuth, samarium, scandium, indium, titanium, cerium, tellurium, tin, lead, antimony, germanium, aluminum, magnesium, palladium, nickel and mercury or optionally mixtures thereof.
[0072] Carboxylic esters which may be used for the processes according to the invention are preferably carboxylic esters of the general formula (3)
R 8 —((O(CH 2 ) m ) n —COO—((CH 2 ) o —COO) p —((CH 2 ) q O) r —R 9 (3)
[0073] where
[0074] R 8 and R 9 are each a C 1 -C 30 -hydrocarbon radical in which one or more nonadjacent methylene units may be replaced by —O— groups, and
[0075] m, n, o, p, q and r are integers having values of from 0 to 6.
[0076] Preference is given in particular to those carboxylic esters of the general formula (3) in which R 8 and R 9 are preferably straight-chain, branched or cyclic C 1 -C 10 -alkyl, C 6 -C 10 -aralkyl, C 2 -C 10 -alkoxyalkyl radicals or C 5 -C 10 -aryl radicals. In particular, R 8 and R 9 are each straight-chain or branched C 1 -C 8 -alkyl radicals.
[0077] m, n, o, p, q and r are preferably integers having values of 0, 1, 2 or 3. In particular, n and p and r have the value 0.
[0078] Particularly preferred carboxylic esters of the general formula (3) are in particular methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-hexyl, n-pentyl and i-pentyl esters of acetic acid, of propionic acid and of butyric acid and (C 6 -C 14 ) alkyl acetate mixtures. The esters and the (C 6 -C 14 ) alkyl acetate ester mixtures may be recovered in very high yield when the products prepared are isolated and reused. When the inexpensive methyl acetate is used as the solvent of the general formula (3), recovery may be dispensed with.
[0079] After the completed reaction and the preparation according to the invention of the organozinc halides in the first step, the reaction mixture is admixed in the second step, customarily at temperatures of from −100 to +200° C., more preferably from −50 to +130° C., in particular from −30 to +80° C., with electrophilic substrates while preferably maintaining the temperature of the exothermic reaction at a predetermined value, optionally by cooling. The upper temperature limit may be defined by the boiling point of the solvent of the general formula (3) used, for example ethyl acetate (b.p.: 77° C.). Preference is given to controlling the temperature of the reaction by cooling.
[0080] Alternatively, the reaction mixture may also be added to the electrophilic substrates. After cooling of the reaction mixture at temperatures of from −20 to +30° C., the organozinc halides of the general formula (4) prepared in the first step may also initially be stored stably and reacted at a later time with electrophilic reaction partners.
[0081] After the end of the addition of all reacting components in the second step, preference is given to allowing the reaction to continue for a further from 5 min to 24 h, more preferably from 5 min to 12 h, in particular from 5 min to 8 h, in order to complete the reaction. At reaction temperatures of from 20 to 90° C., the post-reaction time is preferably from 5 min to 2 h, in particular from 5 min to 30 min.
[0082] Excess zinc metal may be removed by filtration. It is also possible to dissolve excess zinc in the acid used in the third step for hydrolysis of the reaction mixture.
[0083] It has proven useful to react the zinc with the reactive halogen compound of the general formula (2) and the electrophilic substrate of the general formulae (5a) to (5d) in a molar ratio of (1 to 3):(1 to 2):1, in particular (1.1 to 1.7):(1 to 1.3):1 in the carboxylic ester of the general formula (3) as solvent.
[0084] Furthermore, the processes according to the invention prove to be advantageous compared to existing process variants. This is because in many cases, in particular at reaction temperatures of from 20 to 80° C., the post-reaction time of from 5 to 30 min is distinctly shortened. This in particular on the industrial scale, allows very good space-time yields and accordingly very good economic viability to be achieved. Very short post-reaction times result in particular from activation of the reaction mixture or of the zinc using trialkylchlorosilane in the carboxylic ester of the general formula (3) as solvent.
[0085] After the completed reaction in the second step, the reaction mixture is hydrolyzed in the third step, customarily at temperatures of from −80 to +90° C., more preferably from −50 to +50° C., in particular from −30 to +30° C., by adding an aqueous acid or base, and zinc compounds and zinc salts which have formed are dissolved. Alternatively, the reaction mixture may also be added to an aqueous acid or base.
[0086] Preferred bases for the hydrolysis are ammonia and organic amines, such as trialkylamines and alkanolamines.
[0087] Preferred acids for the hydrolysis are Bronsted acids, in particular strong acids such as boric acid, tetrafluoroboric acid, nitric acid, nitrous acid, phosphoric acid, phosphorous acid, hypophosphorous acid, sulfuric acid, sulfurous acid, peroxosulfuric acid, hydrochloric acid, hydrofluoric acid, hydroiodic acid, hydrobromic acid, perchloric acid, hexafluorophosphoric acid, benzenesulfonic acid, p-toluenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid and carboxylic acids such as chloroacetic acid, trichloroacetic acid, acetic acid, acrylic acid, benzoic acid, trifluoroacetic acid, citric acid, crotonic acid, formic acid, fumaric acid, maleic acid, malonic acid, gallic acid, itaconic acid, lactic acid, tartaric acid, oxalic acid, phthalic acid and succinic acid.
[0088] In particular, ammonia, hydrochloric acid, sulfuric acid, citric acid or acetic acid, preferably ammonia, hydrochloric acid or sulfuric acid, are used. The acid or base may be used in concentrated form or in the form of a dilute aqueous solution.
[0089] The products of the general formula (1) prepared may be isolated by known, customarily used methods such as extraction, distillation, crystallization or by means of chromatographic methods. In most cases, the crude product obtained after removal of the solvent is of very high purity or sufficient purity and may be used immediately in subsequent reactions and conversions, in particular ester hydrolyses.
[0090] The pressure range of the reaction is uncritical and may be varied within wide limits. The pressure is customarily from 0.01 to 20 bar, and preference is given to carrying out the reaction under atmospheric pressure.
[0091] Preference is given to carrying out the reaction under inertization with protective gas such as nitrogen or argon. The reaction may be carried out continuously or batchwise, preferably batchwise.
[0092] All of the abovementioned symbols of the abovementioned formulae are each defined independently of one another.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0093] In the following examples, unless otherwise stated, all quantity and percentage data are based on weight, all pressures are 0.10 MPa (abs.) and all temperatures are 20° C.
EXAMPLE 1
Preparation of tert-butyl 3-hydroxy-3-phenylpropionate
[0094] At room temperature, a three-neck flask equipped with a reflux condenser, internal thermometer, dropping funnel and stirrer under nitrogen protective gas was initially charged with 8 g of zinc powder (122 mmol) in 47 ml of ethyl acetate. After 1.9 ml of trimethylchlorosilane (15 mmol) had been added, the mixture was heated to 60° C. for 15 min, then allowed to cool to 55° C. and 22 g of undiluted tert-butyl bromoacetate (113 mmol) were subsequently added dropwise within 5 min, and the temperature was maintained at 65° C. by external cooling. The mixture was then stirred at 50° C. for 10 min. After cooling to 0° C., 10 g of undiluted benzaldehyde (94 mmol) were added, and the temperature was maintained at 10° C. by external cooling. After stirring had been continued at 25° C. for 90 min and 35° C. for 15 min, 40 ml of ethyl acetate were added, the mixture was cooled to 15° C., acidified with 17 ml of 20% hydrochloric acid to a pH of 1-2 and the mixture was stirred for 10 min, during which excess zinc dissolved. The organic phase was then removed. The organic phase was then stirred with 15 ml of concentrated ammonia solution at 25° C. for 10 min. After the phase separation, drying was effected over sodium sulfate and the solvent was distilled off under reduced pressure. Tert-butyl 3-hydroxy-3-phenylpropionate was obtained in a yield of 20.3 g (97% of theory) and had a boiling point of 102° C. (1.5 mbar).
[0095] Similar preparation in the solvents methyl acetate, isopropyl acetate and n-butyl acetate produced tert-butyl 3-hydroxy-3-phenylpropionate in yields of 19.9 g, 20.5 g and 20.1 g (95, 98 and 96% of theory, respectively).
EXAMPLE 2
Preparation of Methyl 3-hydroxy-3-phenylpropionate
[0096] At room temperature, a three-neck flask equipped with a reflux condenser, internal thermometer, dropping funnel and stirrer under nitrogen protective gas was initially charged with 7.6 g of zinc powder (115 mmol) in 45 ml of isopropyl acetate. After 1.83 ml of trimethylchlorosilane (14 mmol) had been added, the mixture was heated to 60° C. for 15 min, then allowed to cool to 55° C. and 16.3 g of undiluted methyl bromoacetate (107 mmol) were subsequently added dropwise within 5 min, and the temperature was maintained at 60° C. by external cooling. The mixture was then stirred at 50° C. for 15 min. After cooling to 30° C., 9.4 g of undiluted benzaldehyde (89 mmol) were added, and the temperature was maintained at 40° C. by external cooling. After stirring had been continued at 40° C. for 30 min, the mixture was cooled to 0° C., acidified with 20 ml of 20% hydrochloric acid to a pH of 1 and the mixture was stirred for 30 min, during which excess zinc dissolved. The organic phase was then removed. The organic phase was then stirred with 30 ml of concentrated ammonia solution at 0° C. for 10 min. After the phase separation, drying was effected over sodium sulfate and the solvent was distilled off under reduced pressure. Methyl 3-hydroxy-3-phenylpropionate was obtained in a yield of 14.3 g (89% of theory) and had a boiling point of 78° C. (0.08 mbar).
[0097] When ethyl bromoacetate was used, ethyl 3-hydroxy-3-phenylpropionate was prepared in a yield of 91% of theory.
EXAMPLE 3
Preparation of Methyl 3-hydroxydecanoate
[0098] At room temperature, a three-neck flask equipped with a reflux condenser, internal thermometer, dropping funnel and stirrer under nitrogen protective gas was initially charged with 7.1 g of zinc powder (108 mmol) in 42 ml of ethyl acetate. After 1.7 ml of trimethylchlorosilane (13.4 mmol) had been added, the mixture was heated to 60° C. for 15 min, then allowed to cool to 55° C. and 15.3 g of undiluted methyl bromoacetate (100 mmol) were subsequently added dropwise within 7 min, and the temperature was maintained at 65° C. by external cooling. The mixture was then stirred at 50° C. for 15 min. After cooling to 0° C., 10.7 g of undiluted octanal (83 mmol) were added, and the temperature was maintained at 5° C. by external cooling. After stirring had been continued at 5° C. for 30 min, 25° C. for 2 h and 40° C. for 20 min, the mixture was cooled to 0° C., acidified with 30 ml of 10% hydrochloric acid to a pH of 1 and the mixture was stirred for 10 min. Excess zinc was then filtered off and the organic phase removed. The organic phase was then stirred with 10 ml of concentrated ammonia solution at 0° C. for 10 min. After the phase separation, drying was effected over sodium sulfate and the solvent was distilled off under reduced pressure. Methyl 3-hydroxydecanoate was obtained in a yield of 14.2 g (84% of theory) and had a boiling point of 59° C. (0.04 mbar).
[0099] Similar preparation in the solvent isopropyl acetate produced methyl 3-hydroxydecanoate in a yield of 15.6 g (87% of theory).
EXAMPLE 4
Preparation of Methyl 3-hydroxy-3-(2-phenylethyl)hexanoate
[0100] At room temperature, a three-neck flask equipped with a reflux condenser, internal thermometer, dropping funnel and stirrer under nitrogen protective gas was initially charged with 7.9 g of zinc powder (121 mmol) in 45 ml of isopropyl acetate. After 1.83 ml of trimethylchlorosilane (12.6 mmol) had been added, the mixture was heated to 60° C. for 15 min, then allowed to cool to 55° C. and 17.7 g of methyl bromoacetate (115 mmol) were added within 5 min, and the temperature of the mixture was maintained at 60° C. by external cooling. The mixture was then stirred at 50° C. for 15 min. After cooling to 40° C., 15.7 g of undiluted 1-phenylhexan-3-one (89 mmol, prepared by base-catalyzed aldol condensation of benzaldehyde and pentan-2-one and subsequent hydrogenation of the 1-phenylhex-1-en-3-one obtained) were added, and the temperature was maintained at 50° C. by external cooling. The mixture was then stirred at 60° C. for 45 min and, after cooling to 15° C., acidified with 20 ml of 20% hydrochloric acid to a pH of 1 and stirred for 30 min. Excess zinc was then filtered off and the organic phase was removed. The organic phase was then stirred with 30 ml of concentrated ammonia solution at 0° C. for 10 min. After the phase separation, drying was effected over sodium sulfate and the solvent was distilled off under reduced pressure. Methyl 3-hydroxy-3-(2-phenylethyl)hexanoate was obtained in a yield of 21.1 g (95% of theory) and a purity of >95% (HPLC).
EXAMPLE 5
Preparation of Methyl 4-hydroxy-4-phenylbutyrate
[0101] At room temperature, a three-neck flask equipped with a reflux condenser, internal thermometer, dropping funnel and stirrer under nitrogen protective gas was initially charged with 15.1 g of zinc powder (231 mmol) in 90 ml of isopropyl acetate. After 3.7 ml of trimethylchlorosilane (29 mmol) had been added, the mixture was heated to 60° C. for 20 min, then allowed to cool to 55° C. and 32.6 g of undiluted methyl bromoacetate (213 mmol) were subsequently added dropwise within 10 min, and the temperature was maintained at 60° C. by external cooling. The mixture was then stirred at 50° C. for 15 min. After cooling to 5° C., 21.3 g of undiluted styrene oxide (178 mmol) were added, and the temperature was maintained at 5° C. by external cooling. After stirring had been continued at 5° C. for 30 min, the mixture was heated to 25° C. within 20 min and stirred at this temperature for a further 30 min. After cooling to 0° C., the mixture was acidified using 33 ml of 20% hydrochloric acid to a pH of 1 and stirred for 30 min. Excess zinc was then filtered off and the organic phase removed. The organic phase was then stirred at 0° C. with 40 ml of 1 N hydrochloric acid and finally washed with 20 ml of concentrated ammonia solution. After the phase separation, drying was effected over sodium sulfate and the solvent was distilled off under reduced pressure (>90% of the solvent isopropyl acetate was recovered). After distillation, methyl 4-hydroxy-4-phenylbutyrate was obtained in a yield of 30.9 g (90% of theory) and had a boiling point of 128° C. (4 mbar).
[0102] Similar preparation in the solvents n-butyl acetate, ethyl acetate and methyl acetate delivered methyl 4-hydroxy-4-phenylbutyrate in yields of 29.5 g, 29.8 g and 28.1 g (86, 87 and 82% of theory, respectively).
EXAMPLE 6
Preparation of Methyl 3-(N-phenylamino)-3-phenylpropionate
[0103] At room temperature, a three-neck flask equipped with a reflux condenser, internal thermometer, dropping funnel and stirrer under nitrogen protective gas was initially charged with 7.6 g of zinc powder (116 mmol) in 45 ml of isopropyl acetate. After 1.83 ml of trimethylchlorosilane (14.4 mmol) had been added, the mixture was heated to 60° C. for 15 min, then allowed to cool to 55° C. and 16.3 g of undiluted methyl bromoacetate (107 mmol) were subsequently added dropwise within 5 min, and the temperature was maintained at 60° C. by external cooling. The mixture was then stirred at 50° C. for 15 min. After cooling to 5° C., 16.1 g of benzalaniline (89 mmol) dissolved in 10 ml of isopropyl acetate were added and the mixture was heated to 25° C. After the mixture had been stirred at 25° C. for 1 h, it was heated to 40° C. for a further 10 min and then cooled to 5° C. Hydrolysis was then effected using 80 ml of concentrated ammonia solution. After 40 ml of isopropyl acetate had been added, the mixture was heated to 50° C. and precipitate formed went into solution. At this temperature, excess zinc was filtered off and the organic phase removed. The organic phase was then washed at 50° C. with 20 ml of water. After the phase separation, the solvent was distilled off under reduced pressure to give a crude product in a yield of 19.7 g (87% of theory) and a purity of >95% (HPLC). After recrystallization from ethyl acetate, methyl 3-(N-phenylamino)-3-phenylpropionate having a melting point of 110° C. was obtained.
COMPARATIVE EXAMPLE 7
Preparation of Methyl 4-hydroxy-4-phenylbutyrate According to SU 472127
[0104] At room temperature, a three-neck flask equipped with a reflux condenser, internal thermometer, dropping funnel and stirrer under nitrogen protective gas was initially charged with 12.1 g of zinc powder (185 mmol) in 80 ml of ethyl acetate. After 2.5 ml of trimethylchlorosilane (20 mmol) had been added, the mixture was heated to 60° C. for 20 min, then allowed to cool to 55° C. and a mixture of 26.1 g of methyl bromoacetate (170 mmol) and 17 g of styrene oxide (142 mmol) was then added dropwise within 15 min while maintaining the temperature at 65° C. The mixture was then stirred at 60° C. for 60 min. After cooling to 0° C., the mixture was acidified using 24 ml of 20% hydrochloric acid to a pH of 3 and stirred for 10 min. Excess zinc was then filtered off and the organic phase removed. The organic phase was then stirred at 0° C. with 30 ml of 1 N hydrochloric acid and finally washed with 15 ml of concentrated ammonia solution. After the phase separation, drying was effected over sodium sulfate and the solvent distilled off under reduced pressure. In the mixture obtained, methyl 4-hydroxy-4-phenylbutyrate could not be detected analytically.
[0105] Accordingly, while a few 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. | A process for preparing organozinc halides in solvents, includes reacting a reactive halogen compound with zinc in one or more carboxylic esters. It is also possible to prepare keto, hydroxyl and amino compounds of organozinc halides obtained in a first step from a reactive halogen compound and zinc in one or more carboxylic esters, wherein the organozinc halide obtained is reacted in a second step with an electrophilic reaction partner and the reaction product of the second step is hydrolyzed in a third step. | 2 |
BACKGROUND OF THE INVENTION
Birds exhibit a variety of feeding behavior patterns, and maybe classified by such habits, i.e., as perch and clinging type feeders. Thus birds such as evening grosbeaks and cardinals like to feed in an upright or perch position and would accordingly be classified as perch type feeders. Many other birds prefer to feed from branches of trees and bushes while hanging or clinging therefrom and hence would be classified as clinging type feeders. It should be, however, recognized that a considerable number of birds may assume either of the above indicated broadly classified feeding attitudes, for instance, birds such as titmice, goldfinch, and chickadees, while classified as clinging birds, also will feed while sitting on top of a branch or other support.
Generally, bird feeders of known construction either provide access for all birds or the feeders are of different sizes for different type birds. Accordingly, it has been found desirable to provide a single feeder having the capability of successfully feeding all these different types of birds.
Also representative of prior art feeders are constructions wherein a hood is disposed generally vertically above a feed assembly so as to protect such from the elements such as rain and snow and also to form a shield so that squirrels and other related pests are prevented or deterred from gaining access to the feed contained therewithin. Such hoods normally take the form of disc or dome shaped constructions, adjustable in varying positions above the feed assembly. However, it is often possible for squirrels while hanging by their hind legs to bypass such a hood and undesirably gain access to the feed. Accordingly, it would be desirable to reduce or prevent such access without expanding the hood dimensions to undesirably large dimensions in relationship to the feed assembly, which has been done in the present invention by supporting the feed assembly from its overlying protective hood in a novel manner.
Further desirable attributes of feeder constructions include the ability of such feeder to reduce feed spillage, to be effectively utilized in high or moderate winds, to provide for protection against rain or other precipitation entering the feed container, and to generally simultaneously assure a constant supply of feed for birds of both the clinging and nonclinging varieties.
SUMMARY OF THE INVENTION
The present invention accomplishes these above indicated aims while further avoiding prior art shortcomings by the provision of a bird feeder construction having a feed assembly comprising a container and feed platform combination and an associated protective hood, said feed assembly and hood being interconnected by means comprising a rigid primary rod on which the hood is longitudinally adjustable. Said container includes a peripheral top portion defining an upper feed access opening for nonclinging or perch feed type birds and said feed platform includes peripheral portions having a plurality of lower feed access openings for cling feeding type birds. The hood is preferably of dome-shaped configuration having an outwardly an downwardly extending portion terminating in a peripheral portion laterally spaced from the peripheral portions of the feed assembly. The feed assembly is also preferably pivotally connected through its suspension from the hood by means of a secondary relatively rigid rod which is in turn interconnected with the lower terminal portions of the first connecting rod. Such an interconnection accordingly permits relatively independent pivotal movement of both the hood and the feed assembly with respect to each other.
It is accordingly a primary object of this invention to provide a bird feeder construction in which an upper feed access opening is provided for birds of the noncling feeding type and a plurality of lower feed access openings are provided for birds of the cling feeding type and wherein an overhanging hood is longitudinally movable relative to said feed assembly so as to selectively permit access of desired birds to said upper feed opening.
Another primary object of the instant invention is to provide a bird feeder construction in which a feed assembly is suspended longitudinally beneath and generally laterally inward of a protective hood member by means of generally rigid centrally disposed connection means and wherein the feed assembly is independently pivotally movable with respect to said hood member.
Still another main object of the present invention is the provision of a bird feeder construction wherein a generally bowl-shaped container for receipt of feed material therein is supported by a feed platform disposed therebeneath wherein openings in the base of the container provide access for feed material within the container to pass downwardly into the feed platform and wherein such openings are so disposed in relation to the plurality of feed access openings in said platform that a properly controlled supply of feed is always available at said feed access openings without undue seed waste, either through gravity run-out or wind-driven spillage.
Further objects of the present invention include the provision of a bird feeder construction which protects the feed container thereof not only from rain or wind-driven precipitation, but also from unwanted species, including pests such as squirrels and the like and which affords easy access for refilling; which provides positive means to assure the availability of seed within the container and feed platform for both nonclinging and clinging type birds and wherein bird recognition of the availability of seed within the container is accomplished.
Other objects, features, and advantages of the invention will become apparent when the description thereof proceeds when considered in connection to accompanying illustrative drawings.
DESCRIPTION OF THE DRAWING
In the drawings which illustrate the best mode presently contemplated for carrying out the present invention:
FIG. 1 is a perspective view of a combined bird feeder construction illustrating the several features and novel aspects of the present invention;
FIG. 2 is a side elevational view of the overall bird feeder combination of the present invention wherein both the upper feed access and the lower feed access openings are clearly respectively available to both perch feed and clinging feed type birds;
FIG. 3 is a top plan view thereof as viewed through the transparent hood member thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a partial sectional front elevational view taken along the line 5--5 of FIG. 2 and showing the manner in which the hood member is longitudinally movable relative to the feed assembly;
FIG. 6 is a top plan view taken along the line 6--6 of FIG. 2 and showing in particular the platform portions of the feed assembly; and
FIG. 7 is a partial sectional view in a somewhat stylized manner showing the buildup of feed within the feed platform as viewed along the line 7--7 of FIG. 3.
DESCRIPTION OF THE INVENTION
The bird feeder construction 10 of the present invention is depicted as comprising a feed assembly 12 and a protective hood member 14 disposed in longitudinally vertical alignment with each other by means of a connection means 16. The hood member 14 is preferably transparent or at least translucent and formed of plastic resinous material such as acrylic or the like and of a generally dome-shaped configuration having outwardly downwardly extending sidewalls 18 emanating from a top portion 20 and terminating in a lower terminal peripheral edge 22.
The connection means 16 includes a primary generally rigid rod-like member 24 having means at its upper end in the form of a hook 26 or the like for suspending the feeder 10 and a connector 28 at its lower terminus including a suspension device such as the ring 30. The primary rod 24 is adapted to pass through a thickened hood reinforcing sector, i.e., boss 32 provided at the top portion 20 of the hood 14, as shown most clearly in FIG. 5. Such boss 32 includes an integral downwardly extending cylindrical portion 32a adapted to rest on a collar 34 which may be releasably secured to the primary rod 24 by means of a twist screw 36 or other equivalent securing means. In this way, then hood 14 is releasably secured in a desired longitudinal or vertical attitude with respect to the primary rod 24 and the feed assembly 12, as will hereinafter be more clearly brought out.
Additionally, the upper portion 20 of the hood is provided with a cover 38 having a central opening 40 for receipt of the primary rod 24 and preferably of dome-like configuration resting on the hood and having downwardly outwardly extending sidewalls terminating in a generally circular edge 44 adapted to engage the hood and accordingly serves to enclose the opening 33 provided in the top 20 thereof as well as a secondary collar 46, similar to collar 34, and adapted for securement with the primary rod above the portion 20 of the hood member so as to restrain the hood from upward movement, such as might be brought about by wind or accidental contact with trees, branches and the like. Also, although the collars, rods and various other components of the feeder 10 are preferably formed of weather-resistant material, the cover 38 serves to protect the upper collar from weather and also prevents rain or moisture from passing through opening 33, such as might tend to wet or dampen the feed housed within the feeder. The cover 38 also provides protection against squirrels chewing on the otherwise exposed collar 46 or its screw retention means 47 associated therewith.
The feed assembly 12 is comprised of a container 50 preferably, as as depicted, of bowl-like configuration having upwardly and outwardly directed sidewalls 52 terminating in a straight collar 54 from which an upwardly and inwardly directed upper flange 56 extends, terminating at inner peripheral edge 57 so as to define a central opening 58 in the top of the container 50. This opening 58 serves as the upper feed access opening for nonclinging or perch type feeding birds. Access of such birds to the opening 58 is afforded by providing an appropriate vertical or longitudinal spacing between the lower edge 22 of the hood and the container 50 of the feed assembly 12, which may be accomplished, as previously indicated, by upward or downward adjustment of the collars 34 and 46. Also by varying the spacing between the hood 12 and the container 50, is a dimension which will admit some perch feed type birds may be arrived at, but which also will prevent entry by larger perch type birds. Such dimensions can be determined by progressively lowering the hood 12 until its lower edge 22 is at least laterally in line with the container terminal edge 57.
The base of the container 50 is provided with a plurality of generally equidistantly spaced and preferably circular openings 59 which permit seed to move from the container 50 downwardly into a feed platform 60 which in turn includes a generally flat base 62 having upwardly extending peripheral sidewalls 64. Such sidewalls terminate in a generally circular ledge 66 which is adapted to receive, that is, contact sidewall portions of the container 50 so as to support the latter in the position illustrated. The lateral extent of the sidewalls 64 is such that they completely surround the grouping of the openings 59. The base of the container 50 also includes an upwardly extending boss 68 which is in turn provided with an internal bore 70 passing completely therethrough and adapted for receipt of a secondary relatively rigid rod-like member 72. The base 62 of the platform 60 is similarly provided with an upwardly extending boss portion 74 having an internally threaded bore 76 passing entirely therethrough. The base 62 of the platform 60 is further provided on its bottom surface with a plurality of outwardly radiating reinforcing ribs 78 so as to assure the necessary rigidity thereof.
As may best be seen by reference to FIG. 5 of the drawings, the rigid rod 72 by threadably engaging bore 76 serves to positively interconnect the platform and container portions of the feed assembly 12. The nut 80 serves to lock the feed assembly in longitudinal position and prevent it from moving up the rod 72 which could take place by movement inparted thereto by wind etc. Alternatively the bore 76 could be smooth i.e., unthreaded, and the lower portion of the secondary rod project downwardly from the base portion of the platform so as to receive a second nut (not shown) and thus serve to interconnect the platform 60 with the container 50 in this alternate manner.
The container 50 is provided with a downwardly extending flange 82 which preferably terminates in a rounded peripheral bead 84. Such flange 82 is radially outwardly offset from the outer extent of the platform sidewalls 64 and thus serves to better initially locate the positioning of the platform 60 with respect to the container 50. Such flange 82 further serves as a drip edge wherein precipitation i.e., rain, moving downwardly along the container sidewalls 52 collects and is diverted thereby and drips from the rounded edge 84 thereof. The flange, in addition to the above features, further by its downwardly projection past the circular contact line between the sidewalls 52 and the inner circular peripheral ledge 66 of the sidewalls 64 serves to block wind or moisture from entering therebetween.
It can best be apparent from reference to FIG. 2 of the drawings that a plurality of lower feed access openings 86 are provided by means of a plurality of downwardly extending notches 88 formed in the sidewalls 64 of the feed platform 60. Such notches 88 terminate at base portions 90 at a height just slightly above the upper surface of the base 62 of the platform 60. The notches are of lateral and longitudinal dimensions such that small clinging birds may cling thereto and simultaneously project their heads inwardly through the openings 86 to gain access to feed present on the platform by reason of its passage through the plurality of openings 59 in the container 50. It should also be brought out at this time that whereas the container and hood portions of the feeder 10 are preferably formed of transparent or at least translucent material, such as the acrylics, so as to enable birds, as well as people, to observe the presence of seed within the container 50; the platform 60, which may be of any suitable material, such as polycarbonate, is preferably colored so that the notches 88 therein may be more easily seen by the birds. Additionally, radially inwardly of each notch 88 is positioned a generally semi-circular baffle 92 upwardly extending from the base 62 of the platform 60 to a terminal height which projects above the edge 90 of each notch 88. The above described relationship between the base and baffle portions forms a well 94 therebetween which by reason of its relationship with the feed openings 59 thereabove, enables seed such as specifically shown in FIG. 7, to pile upwardly behind said baffle and provide a relatively seed free well area 94 to prevent seed from spilling out of openings 86. In addition, small clinging type birds may grasp the slight upwardly extending base portions below edge 90 without encountering obstruction from seed piled up directly there behind. It is also important that the height of the base portions below edges 90 be slight inasmuch as this reduces the wall extent available for grasping by larger undesirable animals, such as squirrels and the like.
Additionally, so that various types and sizes of feed can be utilized with ease, that is, with assurance that seed will be available but will not overly spill by gravity flow out of the lower feed access openings 86; the number of feed openings 59 provided is not equal but rather is preferably less than the number of lower feed access openings 86. As depicted, there may be six openings 59 and 8 lower access openings 86. Because the relative number of openings above described is unequal, at least some of the openings 59 are staggered in their radial alignment with openings 86. In those cases where alignment or substantial alighnment exists, a greater amount of seed is able to reach the sidewalls 64 of the platform 60 and in those cases where there is total or substantial misalignment, a lesser amount of seed moves to the position where it is accessible through the lower feed access openings 86. By providing for the above described partial alignment, a controlled balance is achieved so that generally the proper amount of feed moves through the openings 59 and piles up on the upper surface of the base 62 and against either the sidewall 64 or the baffle 92. In this manner then the feeder is adapted to take all kinds of seed ranging from large sunflower seeds to very small seed such as thistle seeds with assurance that sufficient large seed will be present adjacent each feed opening 88 and with equal assurance that not too much small seed will accumulate adjacent each opening.
It is also important that the size of the openings 59 be large enough to assure the flow of enough seed to the feed platform. A desirable feed flow for a variety of feeds has been found to take place with six openings, each 11/8 inch in diameter and radially offset a distance of 13/4 inches from the center line of the container 50, when such container is circular and of a 6 inch diameter, when combined with eight notches 88 similarly equidistantly spaced and extending about 11/8 inches in height and of an approximate width of 7/8 inch.
Squirrels and other pests are further deterred from reaching seed within the container by the relative dimensioning of the hood 14 so that a squirrel hanging by its hind legs from the primary rod 24 cannot reach over the hood into the container. Also, if the squirrel lets go of the rod 24 or the hood and attempts to catch the seed platform as he passes by in mid air, the feed assembly 12 tends to swing away by reason of its pivotal suspension from the rod 24. Such pivotal suspension is accomplished by means of engaging an upper terminal hook 96 of the secondary rod 72 within the terminal ring 30 of the rigid rod 24. The feed assembly 12 is thus free to swing independently of the hood. Such feature also enables the feed assembly 12 to remain relatively stable when the hood 14 swings in the wind, and thus further contributes to reduced seed spillage such as might be caused by wind or the like. Also, the quick-detach connection between ring 30 and hook 96 enables the feed assembly to be readily detached to facilitate refilling of the latter, whenever necessary or desirable.
Rain or moisture which may enter the platform is dried out by circulation of air through the holes 98 provided in the base 62 of the feed platform.
It should also be understood that the various embodiments either singly or in combination with the above described constructions forming the novel features of the present invention may be utilized in a non-suspended form, that is, mounted on an upright pole. In such cases the pole may either entirely project through the openings 76, 70, and 33, respectively, provided in the central bosses of the feed platform, feed container and the hood member or may alternatively be provided with a threaded upper terminus which would threadedly connect to threaded bore 76 and then a second rigid rod would extend upwardly from bore 76, through bore 70 and opening 33. It will be understood that in any non-suspended assembly, there will be no pivotal connection between the hood 14 and the container 12, nor is any needed, since any movement of the feeder by wind or the like is negligible and also because squirrels or the like would now approach the feeder from below, rather than from above.
While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims. | A bird feeder construction adjustable for feeding birds exhibiting all kinds of feeding behavior patterns including, for example, birds which feed while perched and birds which feed while in a clinging position. In general the construction includes a feed assembly having a container portion and a platform portion, the container including an open top defining an upper feed access for nonclinging or perch type feeding birds and the platform provided with a plurality of openings forming lower feed access openings for small cling feeding type birds. In addition, a hood member is provided so as to protect the feed assembly from the elements and unwanted species including large birds, squirrels, and the like. Also, means are provided for enabling the feed assembly to be independently pivotally movable with respect to the hood member. | 0 |
BACKGROUND OF THE INVENTION AND PRIOR ART STATEMENT
A trophy usually includes a pedestal on top of which is mounted a figurine signifying a particular event. The pedestal often includes a base and a capital joined by a column. In the past, the base and the capital have been similarly constructed of a solid, marble-like material. However, this has proved to be too expensive.
During the past few years, there has been on the market a base made and sold by the assignee of the present application. This base was hollow, having top and bottom members and a side wall. The interior was filled with an initially fluid material such as gypsum. The fluid material was allowed to set, resulting in a base which approximated a marble base in size, shape, weight and somewhat in appearance. Posts on the bottom member extended into the filler material to improve the interconnection between the top and bottom members. Bosses on the top and bottom elements had bores extending therethrough, which bosses mated to reduce the possibility of the initially fluid filler material from leaking out. However, it was found that even with these bosses, the filler material had a tendency to leak out.
SUMMARY OF THE INVENTION
It is therefore an important object of the invention to provide a trophy base having a hollow interior which is filled with an initially fluid material, and which has means substantially to eliminate material from leaking out during filling.
In summary, there is provided a base for a trophy comprising a bottom plate member, a top plate member spaced from the bottom plate member, a side wall between the bottom plate member and the top plate member and around the peripheries thereof, the wall and the plate members defining a shell with a substantially hollow interior, the bottom plate member having a hole therein for admitting into the hollow interior fluid filler material which is thereafter allowed to set, first and second bosses respectively on the top plate member and the bottom plate member and extending toward each other, the bosses respectively having aligned first and second bores extending therethrough for receiving a fastening bolt, the inner ends of the bosses being in contact to minimize the amount of fluid filler material entering the bores during the filling of the shell, and an annular lip on one of the bosses having an internal diameter greater than the exterior diameter of the other of the bosses and a height substantially equal to the height of the other boss, the outer surface of the lip contacting the member carrying the other boss substantially to eliminate fluid filler material from entering the bores during the filling of the shell.
The invention consists of certain novel features and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the details of the article may be made without departing from the spirit, or sacrificing any of the advantages, of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purposes of facilitating an understanding of the invention, there is illustrated in the accompanying drawings a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, the invention, its construction, and many of its advantages should be readily understood and appreciated.
FIG. 1 is a perspective view of a trophy base incorporating the features of the present invention, a portion of the column and rear plate being shown in phantom;
FIG. 2 is a front elevational view of the trophy base depicted in FIG. 1, with the column, the capital, and the lower portion of a figurine depicted in phantom;
FIG. 3 is a top plan view of the trophy base;
FIG. 4 is an enlarged sectional view of the trophy base taken along the line 4--4 of FIG. 3, but with most of the filler material not shown;
FIG. 4A is a sectional view like FIG. 4, but only the central portion thereof, and the top and bottom plate members slightly displaced from their final positions;
FIG. 5 is an enlarged sectional view of the trophy base taken along the line 5--5 of FIG. 3, with most of the filler material not being shown;
FIG. 6 is a top plan view of the bottom plate member of the trophy base;
FIG. 7 is a bottom plan view of the trophy base;
FIG. 8 is a view on an enlarged scale of the matter in the circle labeled "8" of FIG. 7;
FIG. 9 is a view like FIG. 8, but with the bottom plate having been removed; and
FIG. 10 is an enlarged view in vertical section showing the details of the bosses and the lip and how they mate with one another.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings, and more particularly to FIGS. 1 and 2 thereof, there is shown a trophy 20 made up of a pedestal 21 carrying a figurine 22. Only the bottom portion of the figurine 22 is depicted. The pedestal 21 includes a base 23, a column 24 mounted on the base 23 and extending upwardly therefrom, a capital 25 carried by the column 24 and secured thereto, and a rear plate 26 in the shape of a trapezoid. In the particular form shown, the capital 25 is smaller than the base 23. They may be of the same size, except that the front of the base is usually sloped, as shown, whereas the front of the capital 25 is squared off.
The base 23 is preferably formed of plastic and comprises a top plate member 30 having a pair of depending side walls 31, a depending rear wall 32 and a front wall 33. The front wall 33 has a sloped portion 34. In the particular form shown, the walls 31, 32 and 33 are integral with the top plate member 30. Extending downwardly from the top plate member 30 is a boss 35 having a bore 36 extending therethrough. The boss 35 is located midway between the wall 31, but is closer to the rear wall 32 than to the forwardmost part of the front wall 33. The bottom or outer end of each of the walls 31, 32, and 33 has a recessed portion to define a ledge 37 completely encircling the base 23. As is best seen in FIG. 9, a groove 38 is formed in the ledge 37 at each of the four corners thereof. Each such groove 38 extends diagonally, opens outwardly, and also opens toward the interior defined by the top plate member 30 and the walls 31, 32, and 33.
The trophy base 23 further comprises a bottom plate member 40 having a hole 41 for admitting fluid, filler material, as will be explained. A plurality of posts 42 is on the bottom plate member 40 and extends upwardly therefrom. A fifth post 43 of larger diameter also is on the bottom plate member 40 and extends upwardly therefrom. The posts 42 and 43 are integral with the bottom plate member 40. A boss 44 is formed on and integral with the bottom plate member 40, which boss 44 has an inner wall 45 that defines a bore or recess 46, the wall 45 having a hole 47 therein. Each of the corners of the bottom plate member 40 is rounded-off as shown, to define an opening 48, as will be described. The lengths of the bosses 35 and 44 are such that the inner wall 45 will contact the inner end of the boss 35, when the parts are assembled. The boss 44 carries an upstanding lip 49 having an internal diameter greater than the external diameter of the boss 35, so that when the parts are assembled an annular air space 49a is created. The height of the lip 49 is substantially equal to the height of the boss 35 so that when the parts are mated, there is contact (A) between the outer end of the boss 35 and the boss 44, and (B) between the outer surface of the lip 49 and the top plate member 30.
The thickness of the bottom plate member 40 substantially equals the depth of the ledge 37, so that, when the bottom plate member 40 is set in place, its bottom surface will be flush with the bottom end of the walls 31, 32, and 33. The lengths of the posts 42 and 43 are such that they are slightly spaced from the top plate member 30. Further, the hole 47 in the inner wall 45 is aligned with the bore 36 in the boss 35. As is best seen in FIG. 8, the rounded-off corners of the bottom plate member 40 define openings 48 which communicate respectively with the grooves 38. Thus, when the bottom plate member 40 is in position, the openings 48 and the grooves 38 define passages for air into the hollow interior of the base 23.
When the top plate member 30 is assembled onto the bottom plate member 40, they define a shell with a hollow interior. Fluid material 50, such as gypsum, is delivered into the hollow interior through the hole 41. The boss 35 being in contact with the boss 44, reduces the amount of material which leaks out through either the bore 36 or the recess 46. Because the lip 49 contacts the top plate member 30, a further barrier to the fluid material is provided, thereby substantially eliminating filler material from leaking out during filling. The gap 49a, which may be present, defines a trap for any such material. Enough material is admitted to fill the entire hollow interior. The openings 48 and the grooves 38 accommodate air flow to pass by the fluid material and to allow same to set. The posts 42 and 43 extend deep within the filler material 50 and are firmly secured thereto. The base 23 is, therefore, strong and has the appearance and effect of a solid body. Yet is of formed of spaced plate-like members and a surrounding wall, with a filler material therein.
As previously noted, the capital 25 preferably has the same basic construction as the base 23, except it is smaller and does not have the sloped portion 34. Moreover, such capital 25 is inverted relative to the position of the base 23; that is, whereas the recess 46 of the base 23 faces downwardly, the corresponding recess in the capital 25 faces upwardly. It is to be understood that the capital 25 may be considered a base also.
In assembling the pedestal 21, a long bolt is threaded through the capital 25, through the central opening in the column 24, and through the bore 36, so that its end resides in the recess 46. A nut is threaded onto such end and, when tightened, it securely holds together the various elements of the pedestal 21. The nut is concealed in the recess 46, while the head of the bolt is concealed within the corresponding recess in the capital 25.
It is believed that the invention, its construction, and its advantages should be readily understood from the foregoing without further description, and it should also be manifest, that, while a preferred embodiment of the invention has been shown and described for illustrative purposes, the details as to the structure are, nevertheless, capable of wide variation within the purview of the invention, as defined in the appended claims. | The trophy base has top and bottom members and a wall, defining a hollow interior filled with initially fluid material, such as gypsum, which is allowed to set. Bosses on the top and bottom members have bores extending therethrough, which bosses mate to minimize the initially fluid filler material from leaking out. An annular lip on one of the bosses encircles the other boss and serves substantially to eliminate fluid material from leaking out. | 5 |
REFERENCES TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 667,357 filed Apr. 15, 1976, now abandoned, which in turn is a continuation-in-part of then copending application Ser. No. 591,929 filed June 30, 1975, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to process and composition for the treatment of fibers, and more particularly to process and composition for imparting anti-soil properties to artificial fibers.
DESCRIPTION OF THE PRIOR ART
In the past, man-made fibers, such as nylon and polyethylene terephthalate, have found widespread use in home and industry as carpets, drapery material, upholstery and clothing. However, deficiencies in these fibers include a lack of water- and oil-repellency, as well as poor soil release properties. To extend the usefulness of the material, it has been sought to impart to these fibers properties that will enable them to resist soiling and to release such soil as is applied to the fabric, thereby decreasing the need for cleaning, while at the same time increasing the effectiveness of such cleaning operations as are in fact performed on the fabricated article.
Past efforts at imparting such soil resistant and soil release properties have concentrated on applying polymeric materials, such as polymers of acrylic and methacrylic esters containing perfluoroalkyl groups, to the fabricated article, usually as emulsions of the additive. However, fabricated textile products generally cannot be dyed after they have been coated with acrylic polymers containing perfluoroalkyl groups since the polymer coating acts as a barrier to penetration of the dye, thus removing the possibilities of a simplified process scheme in which the finish is applied prior to dyeing. Representative such polymeric finishes are disclosed in U.S. Pat. No. 3,171,861 of Mar. 2, 1965 to A. H. Ahlbrecht (e.g. Example 6) and in U.S. Pat. No. 3,514,487 of May 26, 1970 to L. G. Anello et al. (e.g. Examples 15, 17, 19-25). Certain monomeric water- and oil-repellent fluorinated compounds retaining "appreciable percentage of oil- and water-repellency after laundering or dry cleaning" are also disclosed in the above U.S. Pat. No. 3,171,861, e.g. quaternary ammonium salt derivatives of fluorinated alcohols, "fixed" by heating the impregnated cloth for 5 to 30 minutes at from 100° to 140° C. (Example 9 at Col. 13).
SUMMARY OF THE INVENTION
In accordance with the present invention, there are provided novel monomeric fluorocarbon additives for the improvement of fibers and articles fabricated therefrom. As used herein, the term "fibrous article" is intended to refer to monofilament fibers, fiber bundles and articles fabricated therefrom (e.g., textile fabrics), woven and nonwoven. These fiber additives are capable of providing oil repellency, water repellency or both to a fibrous article, particularly to such articles from polyethylene terephthalate, with various degrees of laundry stability and abrasion resistance, allowing the production of fibrous articles having a wide range of surface properties.
The compounds of the invention can be defined as a partially or fully acylated polyol compound, particularly the triply or quadruply acylated polyol, pentaerythritol, or the doubly or triply acylated polyol, glycerol, acylated to form polyester molecules containing at least two highly fluorinated alkyl or alkoxyalkyl mono ester moieties of phthalic or terephthalic acid, in which moieties a perfluorinated C 2 to C 20 radical is attached to a C 2 to C 6 alkylene diradical, attached in turn to one carboxy oxygen of phthalic or terephthalic acid.
Preferred perfluorinated radicals are n-alkyl, especially C 5 to C 10 ; or (CF 2 ) n OR f where R f designates C 1 to C 6 perfluoroalkyl, particularly perfluoroisopropyl and (CF 2 ) n is a straight chain C 2 to C 10 diradical.
When the esterifying polyol is doubly acylated glycerol, the esterified mono ester is preferably a terephthalate; and/or a perfluorinated radical containing a straight chain of at least six perfluorinated carbon atoms is present in the compound.
When the perfluorinated radical is sufficiently long, i.e. contains a straight chain of at least six perfluorinated carbon atoms, the esterifying compound, instead of being pentaerythritol or glycerol, can be another polyol, particularly paradihydroxybenzene (i.e. hydroquinone), ethylene glycol, and the like.
The invention includes also fibers, especially of polyester such as polyethylene terephthalate ("PET") having a compound of the invention incorporated therein, whereby to impart oil and water repellency to such fiber, durable against abrasion and laundering.
These fluorocarbon chemicals can be applied to fibrous articles by several methods. In one method, the selected additive is intimately blended with resin and the blend then extruded to form a fiber having the selected additive incorporated therein. Subsequent heat treatment of the extruded fiber may be employed to further lower the surface tension of the fiber.
In a second method of the present invention, a fibrous article is contacted with the additive dissolved or dispersed in liquid medium. The liquid medium can be an organic solvent, especially a polar organic solvent, having the desired fluorocarbon additive dissolved therein. Alternatively, an aqueous emulsion or dispersion of the selected fluorocarbon additive dissolved in organic solvent can be used. Each of these alternative treatments is followed, in general, by annealing of the treated article.
It has been found by observation of fiber cross-sections under high magnification that the monomeric fluorocarbon additives of the present invention enter into the fiber surface and become an integral part of the fiber, in contrast to the non-compatible polymeric fluorocarbon chemicals of the prior art. Thus, while fibers obtained following treatment with the monomeric additives of the present invention may possess a concentration gradient of the additive, with the highest concentration of additive at the surface of the fiber, these fibers are more nearly homogeneous in composition. Thus, a fiber is produced which tends to retain its oil and stain resistant properties longer than fibers provided with a prior art polymeric fluorocarbon coating since the additive, once incorporated into the fiber surface, resists being abraded away with wear or laundering.
In addition, it has been surprisingly discovered that the fluorocarbon additives of the present invention do not prevent the fibrous articles from being dyed subsequent to the introduction of the additives into the fiber. Indeed, these additives have been found capable of being absorbed by a fibrous article from a dye bath, thereby resulting in a substantial reduction in processing and equipment costs which arise from the use of separate dyeing and oil/stain-proofing steps. Further, it has been observed that the additives of the present invention will not appreciably transfer from the treated fibrous article to an untreated fabric or fiber, thereby enabling laundering or further processing of fibrous articles treated in accordance with the process of the present invention.
Thus, the additives of the present invention may be incorporated into a fiber, yielding a modified fiber from which a desired fabricated article (e.g., a carpet) may be made as by use of such standard fiber processing steps as crimping, twisting, tufting, knitting, weaving, etc. without destroying the modified surface properties of the fiber.
DETAILED DESCRIPTION OF THE INVENTION
Suitable additives in the practice of this invention are: ##STR1##
The additives can be obtained by standard techniques employing the corresponding phthalate monoester chloride or terephthalate monoester chloride. The desired phthalate or terephthalate monoester chloride can be reacted with the selected polyol under conditions as illustrated in the Examples below.
PREPARATION OF FIBERS
When it is desired that the selected additive of the present invention is incorporated into the appropriate resin prior to extrusion of the resin to form the fiber, the filaments of this invention can be prepared by forming an intimate blend of the additive and the resin, and then extruding the blend into filaments in accordance with methods known to the art. A method of forming the blend is not critical. The blend can be formed by treating the resin in powder form with a solution of the additive and then flash evaporating the solvent. Also, pellets of resin can be treated with a solution of the additive followed by evaporation of the solvent. The pellets with additive incorporated thereon may be then extruded to form a fiber or first extruded and again pelletized. Another method of forming the blend comprises dry blending the additive with the resin in powder form and then working the mixture on a rubber mill or similar device. The additive is preferably, however, added directly to the resin melt in the extruder.
While the quantity of additive incorporated into the resin prior to extrusion thereof may vary widely depending on the degree of surface tension lowering desired, the particular additive and resin selected for use, the extrusion temperature and other factors, additives of the present invention are generally employed in the resin in an amount of up to about 3 percent by weight, preferably from about 0.01 to 2.5 percent by weight, and most preferably from about 0.1 to 1 percent by weight of the resin.
The incorporation of these additives into the resin does not interfere with the formation of the filament or fibers drawn therefrom and the compatible additives do not disturb the normal microscopic homogeniety of the polymer phase. This is surprising in view of the critical rheological conditions involved in the extrusion of filaments.
In some instances, the surface energy of the filament can be lowered even further by annealing the filament after it has been extruded and drawn. Annealing increases the mobility of the additive and allows additional additive to migrate to the surface of the filament. To minimize the time requirement, annealing will be carried out at the highest practical temperature, which is normally above the glass transition temperature of the fiber and below the lower of (1) the fiber degradation temperature and (2) the additive degradation temperature. The degradation temperature of a given additive can be readily determined by routine experimentation, as by thermogravimetric analysis.
Annealing can be performed in an inert atmosphere, such as nitrogen, to prevent oxidative degradation of the fiber, but can also be performed in air, as in a circulating air oven. Alternatively, the surface energy of the fiber may be lowered by other conventional treatments, such as by treating the fiber with steam, for example, at a temperature of from about 100° to 220° C., boiling the fiber in water or boiling the fiber in an aqueous solution containing up to 1 weight percent of a swelling agent for the fiber, such as any of the carrier solvents typically employed in dyeing the fiber, e.g. methyl salicylate for polyethylene terephthalate fibers.
The extruded fiber can be dyed or further processed as for example by tufting, weaving, texturizing, crimping, etc. to produce a fabricated article having the desired low energy surface properties. Dyeing of the fiber or of an article fabricated therefrom has been found not to be adversely affected by the presence of the additive in the fiber, and level dyeing is observed. Use of a conventional swelling agent and/or dye bath temperatures greater than about 75° C. are preferable to enhance the rate of absorption of the dye by the fibrous article.
In a second general process of incorporating an additive of this invention with a fiber, the selected additive is applied to a fibrous article from liquid medium under conditions sufficient to allow the additive to be absorbed into the fiber. Subsequently, the fibrous article can be heat treated as by annealing, contacting with steam or boiling in a suitable solvent, to develop the fiber surface and to achieve the desired surface energy. The amount of additive to be incorporated into the fibrous article by this method is not critical and may vary widely depending upon the additives selected, the desired lowering of surface energy sought, the fiber, and other factors. Generally, however, additive is absorptively incorporated into a fibrous article in an amount of up to about 2.5 percent by weight, preferably from about 0.01 to 2 percent by weight of the article and most preferably from about 0.1 to 1 percent by weight of the article. Thus, the quantity of additive that is contained in the liquid medium will generally be sufficient to provide a fibrous article having the additive incorporated therein in the above amounts, e.g. up to about 2.5 percent by weight of the fibrous article.
The additive can be applied to the fiber before, during or after the application of a spin finish to the fiber and before or after crimping or texturizing of the fiber.
Absorption of the selected additive into the fibrous article can be achieved by several methods. Thus, the article can be contacted with an organic solvent having the additive dissolved therein, or with an aqueous emulsion or dispersion of the additive. The amount of additive incorporated into the liquid medium for contact of the fibrous article may vary widely depending upon the additive, fiber, the fiber properties desired, and other factors. Generally, however, the additive is incorporated into the liquid medium in an amount of from about 0.1 to 50% by weight, and most preferably from about 0.5 to 10% by weight. The temperature of the liquid medium used to treat the article is also not critical. Typical it may be from 0° to 50° C. The time of treatment is largely a matter of convenience and can range from less than one second up to 3 hours. The liquid medium containing the selected additive and the fibrous article can be contacted by any standard method employed in the industry to contact a liquid and fiber or article fabricated therefrom. Thus, the liquid can be applied by a roll to a fiber, or the article can be sprayed with the selected liquid medium or immersed therein.
When an aqueous emulsion or dispersion is selected for use, the aqueous medium is prepared by employing a suitable emulsifying or dispersing agent.
The liquid medium used in such emulsion or dispersion can contain a polar organic solvent of the additive and can also contain such carrier solvents or swelling agents as are typically employed in the industry to aid dyeing of the fibrous article which is being treated. Such carrier solvents typically enhance the ability of the additive to penetrate the fiber, thereby increasing the efficiency with which the fiber absorbs the additive. Thus, where a polyethylene terephthalate fiber, or article fabricated therefrom, is to be treated with an additive of the present invention, the commercial solvents sold under the trademarks Carolid, Charlab RP-3, Tanarol and Latyl and methyl salicylate can be employed as carrier solvents in the liquid medium to accelerate the rate of absorption by the fiber of the additive contained in this medium. Carrier solvents are employed in conventional amounts.
When it is desired to employ an organic solution of the additive, the organic solvent selected will, of course, depend upon the solubilities of the solvent for the additive. Suitable organic solvents, which may be easily determined by routine experimentation, include: ethers (e.g. dioxane); ketones (e.g. acetone); and alcohols (e.g. isopropanol). Carrier solvents as above noted can be used together with such organic solvents.
The aqueous and organic liquid mediums can contain a dye to enable concurrent dyeing and additive absorption. The dye selected is not critical and dyes such as dispersed dyes (e.g. Resolin Blue FBLB and Nacelan Blue FFRN (C.I. Disperse Blue Three) have been found quite satisfactory. The quantity of dye employed is not critical, and may be used in the amounts conventionally employed to obtain the desired shade. Use of a suitable conventional swelling agent and/or dye bath temperature greater than about 75° C. is preferred to enhance the absorption of the dye by the fibrous article.
Following treatment of the fibrous article with the selected liquid medium, the article may be optionally air dried and then subjected to a heat treatment in order to achieve further lowering of the surface tension of the untreated article and/or enhanced durability of the modified fiber surface to wear, home laundering and dry cleaning. The heat treatments, in general, can be performed by treating as with steam at temperatures of from about 100° to about 220° C., by heating the article in water or in an aqueous emulsion of carrier solvent, e.g. methyl salicylate for polyethylene terephthalate, at temperatures up to the boiling point of the liquid, or by annealing the fibrous article in a circulating or static air oven at a temperature of from about 90° to 230° C., and preferably from about 120° to 150° C. The time of such heat treatment is generally from about 1 to 240 minutes.
The Examples which follow are illustrative of our invention and of the best mode contemplated by us of practicing our invention but are not to be interpreted as limiting. Temperatures in these Examples are in °C.
EXAMPLE 1
Preparation of Additive No. 1
(A) A mixture of phthalic anhydride powder (29.6 g, 0.2 mole) and 4-perfluoroisopropoxy-3,3,4,4-tetrafluorobutanol (66 g., 0.2 mole) is heated 10 hours at 110°-120°. The crude product is poured into a solution of Na 2 CO 3 (24 g) in water (2 l.). The resulting solution if filtered, washed with benzene and acidified. The acidified solution is extracted with chloroform. The organic layer is washed twice with water and dried over MgSO 4 . Evaporation of chloroform in vacuum yields 93.3 g (96.5%) of the monoester: mono(4-perfluoroisopropoxy-3,3,4,4-tetrafluorobutyl) phthalate; m.p. 64°-68°. Crystallization from n-haptane affords 85.2 g (88.2%) of the pure product; m.p. 67°-68°, nmr δ12.3 (1H,s,), δ7.5-8.2 (4H,m), δ4.65(2H,t), δ2.6(2H,t of t). Evaporation of solvent from the mother liquid results in 12.2 g of an oil which crystallizes on standing. The crystals are found to be a mixture of the monoester and bis(4-perfluoroisopropoxy-3,3,4,4-tetrafluorobutyl)phthalate. For monoester C 15 H 9 O 5 F 11 (478.2) Calc. 37.67%C, 1.90% H, 43.7%F, 2.09 meg. of CO 2 H/g. Found: 37.23%C, 2.09%H, 45.8%F, 1.98 meq. CO 2 H/g.
(B-1) A mixture of thionyl chloride (80 ml) and the monoester of Part (A) above (60 g, 0.126 mole) is heated 3 hours to 80°, at which point the heating is stopped and the mixture stirred overnight. Thionyl chloride is then distilled off in vacuum, causing crystals of phthalic anhydride to appear. The product is dissolved in n-hexane and the crystals (1.1 g) are filtered off. The solvent is then evaporated and the acid chloride formed is dissolved in dioxane (80 ml). This solution is then treated with a solution of pentaerythritol (4.27 g, 0.0314 mole) is pyridine (60 ml), and the resulting mixture heated 15 hours at 80°. Most of the pyridine and dioxane is then evaporated in vacuo, and the residue is poured into water. The organic layer is dissolved in ether, and the ester layer is washed successively with diluted HCl (1:1), water, Na 2 CO 3 solution, and dried over MgSO 4 . Evaporation of ether in vacuum gives 59.1 g (95.2 %) of oil which crystallized on standing; nmr: δ7.5 (16H,m), δ4.5 (16H,t), δ2.4 (8H,m). Per elemental analysis, the product is the desired phthalic ester compound No. 1 of the above list, contaminated with about 5% of the above noted bis-ester of phthalic acid.
(B-2) In an alternative procedure, a mixture of the monoester (20 g, 0.042 mole), pentaerythritol (1.42 g, 0.0104 mole) and trifluoroacetic anhydride (20 ml) is stirred about one hour at room temperature, until homogeneous. The excess of trifluoroacetic anhydride and acid is distilled off in vacuum, and the residue is dissolved in benzene and then washed with 10% NaOH solution. The product obtained (21.5 g, 100%) has essentially the same IR and nmr spectra as the product prepared by the first method; nmr δ7.7 (16H,m), δ4.7 (16H,t), δ2.6 (8H,m).
EXAMPLE 2
Preparation of Additive No. 2
(A) A mixture of 8-perfluoroisopropoxy-1,1,2,2-tetrahydroperfluorooctanol (20 g, 0.030 mole) and phthalic anhydride (5.6 g, 0.0378 mole) is heated 20 hours at 110°. The crude product (monoester) is crystallized from benzene yielding 20.9 g of the pure product, m.p. 67°-69°, 1.46 meq. of CO 2 H/g (theory 1.475 meq. of CO 2 H/g), IR: 2500-3300 cm -1 (OH and CH), 1740 cm -1 , 1680 cm -1 (C═O), 990 cm -1 (C-F); nmr: δ11.8 (1H,S), δ7.4-8.2 (4H,m), δ4.7 (2H,t), and δ2.7 (2H,t of t).
(B) A mixture of this monoester (19.2 g, 0.0283 mole), pentaerythritol (0.89 g, 0.00655 mole), and trifluoroacetic anhydride (20 ml) is stirred 3 hours at 30°. Employing isolation procedure described in Example 1 (B-2) yields 14.09 g (77.5%) of the desired phthalic ester, nmr: δ7.6 (16H,m), δ4.65 (16H,t), δ2.6 (8H,t of t), unreacted CH 2 OH groups δ3.8 (2H).
EXAMPLE 3
Preparation of Additive No. 3
(A) A solution of KOH (25.6 g, 0.456 mole) in 4-perfluoroisopropoxy-3,3,4,4-tetrafluorobutanol (see U.S. Pat. No. 3,514,487 above cited, Ex. 18) (300 ml) is added to an efficiently stirred solution of bis(4-perfluoroisopropoxy-3,3,4,4-tetrafluorobutyl) terephthalate (398.1 g, 0.504 mole) in the above alcohol (300 ml). When the temperature decreases to 34°, ether (500 ml) is added in order to facilitate stirring. The mixture is refluxed 6 hours. The desired precipitated potassium salt of the terephthalate monoester is filtered off, washed by ether and dried in vacuum oven at 60°/0.2 mm Hg. There is isolated 207.8 g (80%) of the salt. For C 15 H 8 O 5 F 11 K (516.3) Calc: 34.89% C, 1.56% H, 60.48% F; Found: 34.51% C, 1.53% H, 40.4% F.
Distillation of the filtrate in vacuum yields the fluoroisopropoxybutyl alcohol and a residue (90 g) which on standing crystallized. The residue is mixed with ether and the insoluble part filtered off, affording additional 0.5 g of the salt. The ether filtrate is evaporated in vacuo, and the residue is crystallized from methanol. The starting ester (87 g, 20%), m.p. 45°-47° is recovered.
The potassium salt (218 g) is ground and dispersed in dry ether (400 ml). To the suspension, cooled by a water bath, a solution of dry HCl (16.5 g) in ether (120 ml) is added. The mixture is refluxed during the addition. It is then stirred 2 hours at room temperature. The ether solution is washed with water until pH 7 is reached and then dried over MgSO 4 . Evaporation of ether yields the monoester (200 g, 99%), m.p. 155°-6°; IR; 1680 and 1720 cm -1 (CO), 1100-1200 cm -1 , 990 cm -1 (C-F), 800 cm -1 (C-H p-substitution); nmr: δ8.2 (4H,s), δ4.67(2H,t), δ2.62 (2H,t of t); For C 15 H 9 O 5 F 11 (478.2) Calc: 37.67% C, 1.90% H, 43.7% F, 2.09 meq. CO 2 H/g; Found: 37.96% C, 1.89% H, 42.9% F, 2.10 meq. CO 2 H/g.
(B) The above terephthalate monoester (20 g, 0.042 mole) and thionyl chloride (40 ml) are stirred overnight and then heated to 80° until all the solid monoester dissolves. The heating is continued two hours. Excess thionyl chloride is evaporated and the residue (ester-chloride) is mixed with a solution of pentaerythritol (1.41 g, 0.0104 mole) in pyridine (20 ml). After five hours of stirring and heating to 80° (bath) the mixture is cooled, pyridine distilled off in vacuum, and water added. The solid precipitate is dissolved in benzene. The benzene layer is then washed, dried and evaporated. The crude product, crystallized from n-heptane, affords 21.2 g (100%) of the desired pure product, m.p. 96°-97°; nmr: δ8.1 (16H,s), δ4.55 (16H,m), δ2.6(8H,t of t); For C 65 H 40 F 44 O 20 (1977); Calc: 39.48% C, 2.04% H, sap. no. 228; Found: 39.02% C, 2.49% H, Sap. No. 239.
EXAMPLE 4
Preparation of Additive No. 4
(A) A mixture of potassium benzyl terephthalate (19.5 g, 0.0665 mole), (prepared from dibenzyl terephthalate and KOH in benzyl alcohol) and thionyl chloride (60 ml) is stirred and refluxed 2 hours. The excess of thionyl chloride is evaporated in vacuo, and the residue extracted with ether. The undissolved precipitate of KCl is filtered off under N 2 . Evaporation of ether yields 16.3 g (89.2%) of a chloride intermediate.
(B) A solution of 8-perfluoroisopropoxy-1,1,2,2-tetrahydroperfluorooctanol (28 g, 0.044 mole) and pyridine (3.5 g, 0.0445 mole) in dioxane (30 ml) is added to a solution of the acid chloride intermediate (12.2 g, 0.044 mole) in dioxane (30 ml). When the exothermic reaction ceases, the mixture is refluxed 2 hours and then poured on ice. The resulting crystals are recovered by filtration, washed with water and dried in vacuo. The crystals are found to comprise crude benzyl(8-perfluoroisopropoxy-1,1,2,2-tetrahydroperfluorooctyl) terephthalate (44.21 g).
(C) A solution of this terephthalate ester in dioxane (200 ml) is hydrogenated at room temperature and 30 psi of H 2 over 3 g Pd on alumina. In 20 minutes 1.1 liter of H 2 is consumed (theory 1.0 l.) The reaction is continued one hour longer, but no more H 2 is consumed. The resulting crystals are dissolved in refluxing dioxane and the catalyst is filtered off. The volume of dioxane is then reduced to 100 ml by distillation and the ester, mono (8-perfluoroisopropoxy-1,1,2,2-tetrahydroperfluorooctyl) terephthalate (26.3 g, 88.2% yield on the alcohol), crystallizes out; m.p. 177°-8°; IR: 1680 and 1710 cm -1 (CO) 1100-1200 cm -1 , 985 cm -1 (C-F); nmr: δ8.0 (4H,s), δ4.53 (2H,t), δ2.53 (2H,t of t); 1.47 meq. CO 2 H/g (theory 1.475 meq. CO 2 H/g).
(D) A mixture of this ester (15.0 g, 0.0221 mole) and thionyl chloride (60 ml) is refluxed 3 hours. The excess of thionyl chloride is evaporated, and the residue is treated with a solution of pentaerythritol (0.75 g, 0.0055 mole) in pyridine (30 ml). The resulting mixture is heated 15 hours to 80° (bath). After cooling, it is poured on ice. The crystals are filtered off and after drying, recrystallized from toluene, affording pure terephthalic ester additive No. 4 (15.7 g, 100%), m.p. 95°; IR: 1740 cm -1 (C═O), 1100 cm -1 , 995 cm -1 , 730 cm -1 (C-F); nmr: δ8.06 (16H,s), δ4.7 (16H,m); δ2.7 (8H,t of t); For C 81 H 40 F 76 O 20 Calc: 35.03 %C, 1.45 %H, 52.00 %F; Found: 34.87 %C, 1.35 %H, 52.10 %F.
EXAMPLE 5
Preparation of Additive No. 5
Ester-chloride (20 g, 0.042 mole) prepared as above in Example 3(B) from the terephthalate monoester and thionyl chloride (30 ml) are mixed with a solution of glycerol (2.02 g, 0.022 mole) in pyridine (20 ml). The mixture is stirred one hour. Ether (50 ml) is added to facilitate stirring. After two hours, the mixture is extracted successively with dilute HCl, 10% Na 2 CO 3 , and water. The ether layer is dried. Evaporation of ether affords 18.1 g (85.2%) of crystals; nmr: δ7.92(8H,s), δ4.6(8H,t), δ2.55 (4H, t of t). For C 35 H 26 F 22 O 12 (1012.5) Calc: 39.14 %C, 2.19 %H, sap. no. 222, Found: 39.05 %C, 2.20 %H, sap. no. 239. Acidification of Na 2 CO 3 extract yielded 2.2 g (11%) of the monoester starting material.
EXAMPLE 6
Preparation of Additive No. 6
(A) A mixture of methacrylates of formula (CF 3 ) 2 CFO(CF 2 ) n CH 2 CH 2 OCOC(CH 3 )═CH 2 having 73% with n=6 and 27% n=8, (432 g)--which can be obtained by the general method of U.S. Pat. No. 3,514,487 above cited (see e.g. Ex. 17, Ex. 23)--was added to a solution of KOH (40 g) in methanol (500 ml). In order to prevent polymerization, p-phenylene diamine (10 g) was added. The mixture was stirred overnight at room temperature. Methanol was evaporated in vacuum and precipitated potassium acrylate was filtered off. The filtrate was distilled. The crude product did not show any C═O peak in the ir spectrum. Distillation on a spinning band column yielded 232.5 g of the fluoro alcohol with n=6, b.p. 52°/0.1 mm Hg (10-perfluoroisopropoxy-1,1,2,2-tetrahydroperfluorodecanol). The distillation residue was contaminated with p-phenylene diamine. It was dissolved in ether, extracted three times with diluted HCl and water. The ether layer was dried and the solvent evaporated in vacuum. The residue was distilled yielding 70.8 g of the fluoro alcohol with n=8, contaminated by about 5% of the lower alcohol.
(B) A mixture of the above 10-perfluoroisopropoxy-1,1,2,2-tetrahydroperfluorodecanol (20 g, 0.0324 mole) and phthalic anhydride (4.7 g, 0.0324 mole) is heated for 20 hours in a 110° bath. The crude product, crystallized from benzene, affords 21.8 g of the desired phthalate monoester, m.p. 85°-88°; ir: 2500-3300 cm -1 (OH and CH), 1740 cm -1 , 1680 cm -1 (C═O), 1100-1200 cm -1 , 990 cm -1 (C-F); For C 21 H 9 O 5 F 23 (778.3) Calc: 32.41% C, 1.16% H; 1.285 meq. CO 2 H/g; Found: 32.33% C, 1.25% H, 1.29 meq. CO 2 H/g.
(C) The above phthalate monoester (12.1 g, 0.0155 mole) and hydroquinone (0.86 g, 0.00782 mole) are stirred 3 hours at 30° in 20 ml of trifluoroacetic anhydride. By distilling off excess trifluoroacetic acid in vacuo and proceeding as in the above Example 1 (B-2), the product of Formula No. 6 above is obtained in 100% yield. (12.7 g); m.p. 94°-95°; nmr; δ7.5-8.2 (8H,m), δ7.4 (4H,s), δ4.7 (4H,t of t); For C 48 H 20 F 46 O 10 (1630.6) Calc: 35.35%C, 1.24%H, 53.59%F, Found: 35.28%C, 1.03%H, 52.3%F.
TREATMENT OF FIBROUS ARTICLES
In the following tests, dip-coating of fabric is performed by dipping the fabric sample into a solution of an additive in dioxane solution at such a concentration that 0.1 to 0.2% by weight of fluorine is contained on the fabric. The fabric is then air dried and annealed at 150° C. for a period of 3 minutes in a circulating air oven.
Oil repellency of the fabric is then measured employing the scale (0 to 8) established by the American Association of Textile Chemists and Colorists in its publication "Technical Manual of the AATCC", volume 46 (Research Triangle Park, N.C.) (1970): AATCC Test No. 118-1966.
A home laundry (HL) cycle, in the tests below, is defined to be one washing in a heavy duty, 6-cycle automatic washer (Sears Kenmore) using a 12 minute hot (40° C.) wash cycle with one cup of Dash detergent (manufactured by Procter & Gamble). The washing is done at a constant load of 3 pounds and with a double rinse. Samples are dried for 30 minutes in an automatic dryer (Sears Kenmore) at a temperature of from 80° to 85° C.
Table 1
Dip-coating tests are performed on polyethylene terephthalate cloth samples (Dacron 54, fine weave, 100 sq. inch samples) to determine the oil repellency imparted to the fiber yielding the data summarized in Table 1 below. The untreated cloth sample used as control is found to have an oil repellency rating of 0. Tests No. 6-10 show results substantially below those of the earlier numbered tests, indicating importance of such factors as para vs. ortho orientation, number of hydroxyl groups acylated, and length of perfluorinated straight chain.
TABLE 1______________________________________Test OilNo. Additive Melting Point (°C.) % Fluorine Repellency______________________________________1 1 oil 0.14 42 2 oil 0.17 63 3 96-97 0.14 64 5 oil 0.14 65 6 94-95 0.18 66 7 oil 0.14 17 13 oil 0.14 28 12 69-71 0.13 19 11 101-102 0.18 210 11 101-102 0.30 3______________________________________
Table 2
To determine the ability of fibers to absorb additives from an aqueous emulsion, additives are emulsified at a concentration of 0.002 g/ml in an aqueous solution containing 0.002 g/ml NACCONOL (a sulfonated alkylbenzene detergent formerly manufactured by Allied Chemical Corp.) by introducing the additive to the solution with continuous stirring at the boiling temperature (about 100° C.) of the solution. In each run, a 5 sq. inch cloth sample (Dacron 54, fine weave) fabricated from polyethylene terephthalate fiber is immersed in 250 ml. of the boiling solution containing the selected additive for a period of 1 or 2 hours without the presence in the solution of any carrier solvent. The cloth samples are then carefully rinsed in hot water and annealed for 5 minutes at 180° C. Testing of these samples shows a marked improvement in oil repellency for the treated samples over the control. These data are summarized in Table 2.
TABLE 2______________________________________Example Additive Boiling Time (hrs.) Oil Repellency______________________________________14 1 2 515 3 1 616 12 2 3Control -- 1 0______________________________________
Table 3
To determine the ability of fibers to absorb the additives of the present invention from an aqueous dispersion employed as a component of a dye bath, dispersions are prepared comprising about 30 weight percent of Marasperse N (manufactured by American Can Co.) or Tamol (manufactured by Rohm and Haas Co.) as dispersing agent; about 30 weight percent of water; about 20 weight percent of additive No. 3 of the present invention; from about 5 to 10 weight percent of sorbitol or GRANAX (manufactured by GAF Corporation) as humectant and from about 2 to 10 weight percent of IGEPAL (nonionic surface active agent manufactured by GAF Corporation) or fatty acid soap as a composition with synergistic effect in forming a dispersion. The dispersion is prepared by adding the additive to the other constituents and boiling the aqueous solution with continuous stirring. Fluorine analysis of a sample of the dispersion thus produced shows it to contain 17.6 weight percent additive.
Dye baths having varying concentrations of additive are then prepared by admixing from about 0.007 to 0.05 gram of the aqueous additive dispersion with approximately 50 grams of water, about 0.01 gram of dye paste (Polynol Yellow), 1 ml of 10% aqueous NaH 2 PO 4 solution and from about 0.05 to 0.1 gram of o-phenylphenol type solvent (manufactured under the trademark Carloid by Tanatex) as carrier solvent. A 1 g. sample of polyethylene terephthalate fabric (Dacron 54, fine weave) is immersed in the selected dye bath for a period of one hour while boiling the dye bath at a temperature of 100° C. The cloth sample is then removed, dried to remove some of the water and then annealed at a temperature of 150° to 180° C. for a period of 2 minutes. The concentration of additive present on the treated cloth is determined by analysis and is compared to the concentration of additive remaining in the bath following treatment of the cloth. The exhaustion of the additive from the dye bath is found to vary from 70 to 90% by weight of initial content of additive in the bath. The data thereby obtained are summarized in Table 3 below:
The dyeing by this procedure, omitting the annealing step, is sometimes spotty. We theorize that this effect is caused by carrier solvent remaining in the cloth. The annealing after dyeing helps to obtain uniform dyeing and higher oil repellency.
TABLE 3______________________________________Additive in Additive on PercentDye Bath.sup.(1) Cloth Sample Exhaustion(Wt. %) (Wt. %) of Additive from Bath______________________________________0.35 0.26 740.50 0.43 860.84 0.80 950.84 0.73 871.6 1.1 69______________________________________ .sup.(1) Percentage relative to the weight of cloth sample
HOME LAUNDRY STABILITY
In order to determine the stability of the low energy surface developed by absorption of an additive from an additive dispersion followed by annealing, cloth samples of polyethylene terephthalate fiber (Dacron 54, fine weave) are prepared containing varying amounts of additive, expressed as weight percent fluorine. The additive selected for use is the terephthalic ester additive No. 3. Each sample is subjected to a number of home laundry cycles, and the oil repellency of the samples is determined following the completion of the desired number of cycles. The data thereby obtained demonstrate that the oil repellency is initially 100 (on a scale of 50 when the fabric repels only pure Nujol liquid paraffin, to 150 when it repels pure n-heptane and intermediate values corresponding linearly to increasing the heptane proportion). The repellency remains at about 70-80 even after the samples are subjected to as much as 40 home laundry cycles, using 0.05-1.05 weight percent additive on weight of fabric. Following completion of the above tests, the cloth samples are thoroughly rinsed with hot running water and then ironed at 150° C. with a standard home iron. For all samples, the oil repellency is thereby brought to 90, indicating that the starting repellency is essentially restored by removal of residual detergent and then annealing.
On dry cleaning, additive No. 3 is found to be removed substantially completely from PET cloth, and oil repellency is lost completely.
Table 4
A 100 square inch sample cloth fabricated from polyethylene terephthalate fiber (either Dacron 54, coarse weave or Dacron 56, double knit) is treated with a dioxane solution containing dissolved therein the terephthalic ester derivative No. 3. The cloth is contacted with the dioxane solution at a temperature of 25° C. for a sufficient period of time to incorporate the desired quantity of additive into the cloth. The cloth is then removed from the solution and annealed at a temperature of about 230° C. for about 21/2 minutes, and then tested to determine the initial oil repellency, abrasion resistance and water repellency ratings. Oil repellency is rated as for the tests of Table 1; water repellency is by AATCC Test No. 22-1967 on a scale of 0-100. A rating of 70-90 is good and 90-100 is outstanding. Abrasion resistance is rated as oil repellency remaining after using a "Crock Meter" device (Type CM-5 of Atlas Electric Devices Co.) in which sandpaper bears for 20 strokes against stretched fabric.
The samples are subjected to a number of home laundry cycles, with the oil repellency, abrasion resistance and water repellency ratings being again determined after 5 and 15 HL cycles. Test results are set forth in Table 4 below. The results show the cloth samples treated with the additive of the present invention to compare favorably in oil repellency, abrasion resistance and water repellency ratings to the commercially available fluorocarbon compounds.
TABLE 4__________________________________________________________________________RUN NO. 1: DACRON 54, COARSE WEAVE, UNSCOURED After 5 After 15Fluoro- Initial Laundry Cycles Laundry Cyclescarbon Oil Abr H.sub.2 O Oil Abr H.sub.2 O Oil Abr H.sub.2 OCompound %F Rep. Res. Rep. Rep. Res. Rep. Rep. Res. Rep.__________________________________________________________________________No. 3Additive: 0.05 5 2 75 5 4 70 3 1 70 0.10 6 4 80 5 5 75 4 2 70 0.25 5 5 -- 5 5 -- 5 3 --SCOTCHGARD* 0.1 6 4 80 5 3 80 4 3 80FC 321* 0.2 6 6 80 5 4 80 5 4 80RUN NO. 2: DACRON 56, DOUBLE KNITNo. 3Additive: 0.05 5 4 75 3 2 60 2 0 50 0.10 6 4 80 5 4 79 3 1 60SCOTCHGARD* 0.1 6 5 85 5 4 80 4 2 80FC 321* 0.2 6 5 90 5 4 80 4 2 80__________________________________________________________________________ Oil Rep. = oil repellency rating; Abr. Res. = abrasion resistance rating; and H.sub.2 O rep. = water repellency rating. *These are commercial products produced by 3M Co.; cloth samples are prepared using the manufacture's recommended procedures.
Table 5
Cloth samples of Dacron 54, coarse weave, are prepared as for the tests of Table 4 to incorporate therein the selected quantity of the desired fluorocarbon compound. Each sample is then subjected to a soil release test employing salad oil and a soiling mixture. The results thereby obtained are summarized in Table 5.
TABLE 5______________________________________ Soil Release Rating 1st HL 2nd HLFluorocarbon Soiling Salad Soiling SaladCompound %F Mixture* Oil Mixture* Oil______________________________________Untreated Control 2.5 2.5 3.5 3.5No. 3 Additive 0.05 2.5 2.5 3 3 0.10 2 2 2 2 0.25 2 2 2 2Scotchgard 0.1 2 2 2.5 2.5FC 321 0.2 2 2 2.5 2.5______________________________________ *Soiling Mixture: 3 Parts Mustard 2 Parts Ketchup 2 Parts Mayonnaise 1 Part Salad Oil 1 Par Used Motor Oil | As an additive imparting oil and water repellency, durable against laundering and abrasion, to PET fibers: a partially or fully acylated polyol, especially pentaerythritol, glycerol, hydroquinone or ethylene glycol, acylated with a phthalic or terephthalic monoester having a perfluorinated alkyl or alkoxyalkyl C 2 to C 20 radical, especially C 5 to C 10 n-alkyl or (CF 2 ) n OR f where R f is C 1 to C 6 perfluoroalkyl, especially perfluoroisopropyl and (CF 2 ) n is a straight chain C 2 to C 10 diradical. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improved method for effecting water control during treating of subterranean zones in wells utilizing aqueous well treating fluids.
2. Description of the Prior Art
High viscosity aqueous crosslinked gels are used in a variety of operations and treatments carried out in subterranean zones or formations including, but not limited to, production stimulation treatments.
An example of a production stimulation treatment utilizing a high viscosity crosslinked gelled fluid is hydraulic fracturing. In hydraulic fracturing treatments, the high viscosity fluid is utilized as a fracturing fluid and also carries particulate propping agent, such as, sand, into the fractures formed. That is, the fracturing fluid is pumped through the wellbore into a formation to be stimulated at a rate and pressure such that fractures are formed and extended in the formation. Propping agent is suspended in the fracturing fluid so that it is deposited in the fractures when the gel is broken and returned to the surface. The propping agent functions to prevent the formed fractures from closing whereby conductive channels are formed through which produced fluids can flow to the wellbore.
Borate ion has long been used as a crosslinking agent for forming high viscosity crosslinked gelled well treating fluids. Various sources of borate ion have been utilized including boric acid, borax, sodium tetraborate and proprietary compositions comprised of boric acid and dimers and trimers of borate ions. Additionally, titanium, zirconium, aluminum, antimony ions and the like have been used as crosslinking agents to form high viscosity crosslinked gelled fluids.
A problem that often occurs during the performance of a stimulation treatment in an oil or gas producing zone which contains high permeability streaks which produce water or is subject to water influx is stimulation of the water producing zones concurrently with stimulation of the oil production. In such instances, water production from the formation may be excessive, requiring expensive separation and water disposal. Alternatively, after a stimulation treatment has been performed, a water control treatment may be attempted to reduce the production of water. The remedial treatments are expensive and are not always successful. The treatments can result in plugging of the formation and loss of production.
It would be desirable to provide a means by which a formation may be treated to selectively reduce the permeability of a subterranean formation to water flow while not damaging the ability of oil to flow through the formation to the producing well.
SUMMARY OF THE INVENTION
The present invention provides improved methods for reducing water production during stimulation treatments employing crosslinked gelled aqueous well treating fluids.
The stimulation treatment is initiated by the introduction of a gelled fluid into the wellbore at a rate and pressure sufficient to fracture the formation. The gelled fluid is basically comprised of water, a hydrated galactomannan gelling agent, a first reactive polymer and a second reactive polymer capable of reacting in situ with said first reactive polymer to form a polycationic branched polymer and a pH adjusting agent capable of providing a pH in excess of about 9 to the fluid containing the reactive polymers. The gelled fluid then is followed with a crosslinked gelled fluid to extend the created fractures into the subterranean formation and transport proppant into the fractures. In one preferred embodiment, the crosslinked gelled fluid is basically comprised of water, a hydrated galactomannan gelling agent and a borate composition comprised of water, a boron source and an alkanolamine or alkylamine. The galactomannan gelling agent is present in the aqueous treating fluid in an amount in the range of from about 0.06% to about 0.72% by weight of water therein. The borate crosslinking composition is present in the crosslinked treating fluid in an amount in the range of from about 0.1% to about 0.8% by weight of water therein.
A borate crosslinking composition useful in accordance with the present invention is comprised of water in an amount in the range of from about 5% to about 96% by weight of the composition, boron (as boric acid) in an amount in the range of from about 3% to about 82% by weight of the composition and an alkanolamine or alkylamine present in an amount in the range of from about 1% to about 13% by weight of the composition. The alkanolamine is preferably an ethanolamine, most preferably mono-ethanolamine.
The methods of using the improved well treating fluids of this invention are basically comprised of the steps of preparing such treating fluids and then pumping the treating fluids into a subterranean zone or formation penetrated by a wellbore. The well then is shut-in for a sufficient period of time to permit the in situ polymerization to occur.
The shut-in time may vary from as little as several hours to over 24 hours. Preferably the wellbore is shut-in for at least about six hours and most preferably about 12 to 18 hours.
It is, therefore, a general object of the present invention to provide improved methods for reducing water production during stimulation treatments of subterranean formations.
Other and further objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon a reading of the description of preferred embodiments which follows.
DESCRIPTION OF PREFERRED EMBODIMENTS
The gelled aqueous well treating fluids of the present invention are simple to prepare and utilize the pH levels of the preferably borate crosslinked gells to facilitate the formation of the in situ reaction product in the initially introduced fluid. Both the gelled treatment fluid and the crosslinked gelled treatment fluid are comprised of water and a hydrated galactomannan gelling agent along with selected other constituents.
The water utilized to form the well treating fluids of this invention can be fresh water, salt water, sea water, brine or any other aqueous liquid which does not adversely react with other components of the treating fluid. The water used in well treating fluids normally contains one or more salts for inhibiting the swelling of clays in the subterranean formations or zones being treated or to weight the treating fluid. The most common clay inhibiting salt utilized is potassium chloride, but other salts can also be used. The pH of the water is preferably in the range of from about 6.0 to about 8.5 to facilitate the hydration of the galactomannan gelling agent utilized.
The galactomannan gelling agents which can be used in accordance with the present invention are the naturally occurring gums and their derivatives such as guar, locust bean, tara, honey locust, tamarind, karaya, tragacanth, carrageenan and the like. These gums are generally characterized as containing a linear backbone consisting of mannose units having various amounts of galactose units attached thereto. The gums can also be characterized as having one or more functional groups such as cis-hydroxyl, hydroxyl, carboxyl, sulfate, sulfonate, amino or amide. Of the various galactomannan gelling agents which can be utilized, one or more gelling agents selected from the group of guar, hydroxyethylguar, hydroxypropylguar, carboxymethylguar, carboxymethylhydroxyethylguar and carboxymethylhydroxypropylguar are preferred. Of these, guar is the most preferred.
When one or more of the above mentioned glactomannan gelling agents are dissolved in water, the gelling agents are hydrated and a viscous aqueous gel is formed. In accordance with this invention, the galactomannan gelling agent or agents utilized are dissolved in the water in an amount in the range of from about 0.06% to about 0.72% by weight of the water, more preferably in an amount in the range of from about 0.12% to about 0.36%, most preferably about 0.30%.
The first reactive polymer comprises an alkyl acrylate polymer of the general formula: ##STR1## which is reacted in situ with a polyethylene oxide chain (OCH 2 CH 2 ) n that can be capped or terminated by hydrogen, hydroxyl, C 1 -C 6 oxyalkyl, C 6 -C 8 oxyaryl, oxy (2 hydroxy-3-chloropropane) or Oxy (-2,3-oxypropane) and the like. Preferably, the polyethylene oxide chain is reacted with epichlorohydrin. The reaction of the two reactive polymers yields compounds of the general formula: ##STR2## with X being from about 10 to 15,000; Y being from about 1 to 5,000 and Z being from about 2 to 10,000 and A - is an anion associated with the quaternary nitrogen, such as chlorine when an epichlorohydrin adduct is utilized. The ethylene oxide chain is capped with methyoxy for purposes of the illustration.
In one preferred embodiment, the first reactive polymer is admixed with the gelled treatment fluid in an amount of from about 1/2 to about 10 percent by weight of the treatment fluid. The second reactive polymer comprising the polyethylene oxide compound is admixed with the gelled treatment fluid in an amount of from about 1/2 to about 10 percent by weight of the treatment fluid. The admixture then is pumped into the wellbore and into the subterranean formation wherein it reacts in the rock matrix over time to form a branched polymer that tends to bond itself to the matrix as a result of its cationic nature.
The in situ reaction generally is effected at a formation temperature in excess of 75° F. and preferably in excess of about 100° F. The pH of the treatment fluid is adjusted to a level of above about 9 to facilitate rapid formation of the polycationic branched polymer by the addition of an alkaline agent such as caustic or the like.
Preferably the pH is adjusted to a level above about 9.5 and most preferably about 11-12.
The gelled treatment fluid is followed by a crosslinked gelled treatment fluid to extend fractures into the subterranean formation from the wellbore. The gelled fluid is displaced by the crosslinked gelled treatment fluid into the created fractures whereupon the reactive polymers leak off into the matrix of the formation and the in situ polymerization reaction is effected.
In an alternative embodiment, the first and second reactive polymers may be introduced into the subterranean formation following the introduction of a quantity of the gelled fluid. In this instance a quantity of the gelled fluid is introduced into the formation and the first and second reactive polymers are introduced as a separate stage in an aqueous fluid. The aqueous fluid typically will include a quantity of a clay control additive such as potassium chloride or tetramethylammonium chloride or the like and a pH adjusting agent such as caustic or the like to raise the pH to a level of above about 9 and most preferably to 11-12. The reactive polymers then may be followed with an additional quantity of the gelled fluid to displace the reactive polymers into the formation or by the crosslinked gelled fluid. If an additional quantity of the gelled fluid is utilized, it then is followed with the crosslinked gelled fluid.
The water and gelling agents of the crosslinked gelled fluid may be any of those previously described. Preferably the crosslinking agent comprises a borate composition which provides buffering to the treating fluid as well as crosslinking the hydrated galactomannan gelling agent in the treating fluid. Preferably the borate crosslinking composition is a liquid solution generally comprised of water, a soluble boron source such as boric acid and an alkanolamine or alkylamine. The water utilized in forming the borate composition is preferably fresh water, but other aqueous liquids can be utilized so long as they do not adversely react with or otherwise affect other components of the borate composition or the treating fluid formed therewith. The water can include one or more freezing point depressants such as ethylene glycol, propylene glycol, alcohols or the like to prevent the borate composition from freezing in cold weather. Preferably, ethylene glycol is combined with the water used in an amount of 50% by weight of the resulting solution which depresses the freezing point of the borate composition to less than about -20° F. The term "water" when used hereinbelow relating to the borate composition means water or other suitable aqueous liquid with or without one or more freezing point depressants dissolved therein. The water is preferably present in the borate composition in an amount in the range of from about 96% to about 5% by weight of the composition, most preferably about 60%.
The boron source can comprise substantially any boron containing compound capable of yielding borate in a solution maintained at a pH above about 7. The boron source can be provided by, for example, boric acid, boric oxide, pyroboric acid, metaboric acid, borax, sodium tetraborate and the like. For simplicity, reference will hereinafter be made to borate or boron content as boric acid or boric acid equivalents. That is, if a weight percentage is specified for boron content as boric acid, it is to be understood that a chemical equivalent amount of, for example, borax or sodium tetraborate could be substituted for the boric acid.
The boron source is preferably present in the crosslinking composition in an amount as boric acid in the range of from about 3% to about 82% by weight of the composition, most preferably in an amount of about 30%.
A variety of alkanolamines or alkylamines can be utilized in the borate crosslinking composition, but the quantity of boron in the composition is reduced as the molecular weight of the amine included in the composition increases. Thus, it is preferred that a relatively low molecular weight alkanolamine be used such as an ethanolamine. The most preferred low molecular weight alkanolamine is mono-ethanolamine. The use of a low molecular weight alkanolamine in the borate composition produces the further benefit of making the composition cold weather stable, i.e., the composition without a freezing point depressant therein does not crystallize or the like at low temperatures down to about 5° F. Other suitable alkanolamines include diethanolamine, 1-amino-2-propanol, 1-amino-2-butanol and the like. The alkylamines can comprise an aliphatic polyamine such as, for example, ethylenediamine, diethylenetriamine, triethylenetetraamine, 1,2-diaminopropane, tetraethylenepentamine and the like. The alkanolamine or alkylamine is generally present in the crosslinking and buffering composition in an amount in the range of from about 1% to about 13% by weight of the composition. When mono-ethanolamine is utilized, it is preferably present in the composition in an amount of about 10% by weight of the composition.
A particularly preferred highly concentrated, stable crosslinking composition useful in accordance with this invention is comprised of water present in an amount of about 60% by weight of the composition, boron calculated as boric acid present in an amount of about 30% by weight of the composition and mono-ethanolamine present in an amount of about 10% by weight of the composition. This composition is stable and is easily pumped and metered at low temperatures. The borate ion concentration in the composition is very high, and the composition has the ability to buffer the resulting treating fluid to a pH between about 8.4 and 9 without the need for any other chemicals such as caustic, sodium carbonate or other buffer.
The crosslinking composition comprised of water, a boron source and alkanolamine or alkylamine is present in the borate crosslinked gelled aqueous well treating fluids of this invention in an amount in the range of from about 0.05% to about 0.8% by weight of water in the treating fluids, preferably in an amount in the range of from about 0.15% to about 0.4%.
A particularly preferred borate crosslinked gelled aqueous well treating fluid of this invention is comprised of water, hydrated guar present in an amount of about 0.30% by weight of the water and the preferred borate composition for buffering the treating fluid and crosslinking the hydrated guar comprised of water, boric acid and mono-ethanolamine described above present in the treating fluid in an amount of about 0.2% by weight of the water.
As will be well understood by those skilled in the art, a variety of conventional additives can be included in the well treating fluids of this invention such as gel stabilizers, gel breakers, clay stabilizers, bactericides, fluid loss additives and the like which do not adversely react with the treating fluids or prevent their use in a desired manner.
The improved methods of the present invention for treating a subterranean zone penetrated by a wellbore are basically comprised of the steps of preparing a gelled aqueous treating fluid containing a first and second reactive polymer and a crosslinked gelled aqueous treatment fluid and pumping the fluids into the subterranean formation. The wellbore then is shut-in for a period of at least several hours to permit the in situ reaction to occur. Preferably the wellbore is shut-in for at least about 6 hours and most preferably from about 12 to 18 hours. In such treatments, the gelled well treating fluids are pumped through the wellbore into the subterranean zone or formation to be fractured at a high rate and pressure whereby fractures are formed in the subterranean zone or formation and a propping agent, such as sand is suspended in the crosslinked treating fluid and carried into the fractures and deposited therein. Thereafter, during the shut-in period the gelled and crosslinked fluids are caused to break, i.e., revert to a thin fluid which can be reverse flowed out of the fractures leaving the proppant therein. Production of hydrocarbons then may be initiated from the treated subterranean formations.
In order to further illustrate the compositions and methods of the present invention, the following examples are provided.
EXAMPLE I
A stimulation treatment was performed using a treating fluid of the present invention. The treated formation was a sandstone formation having a permeability of from 4-6 md at a depth of about 7500 to 7700 feet. The wellbore was perforated over 8 feet at 4 shots per foot at a depth of about 7570 feet. The bottom hole static temperature was about 135° F. The treatment was effected at a rate of about 10 barrels per minute at about 2000 psi. The treatment comprised: 5000 gal of a gelled preflush comprising 25 lbs guar/1000 gal of fluid; 8000 gal of 2% KCl solution containing 5% by weight reactive polymers of the present invention, 1 gal/1000 gal of surfactant, 5 gal/1000 gal of 25% by weight caustic solution; 4000 gal of a gelled fluid comprising 25 lbs guar/1000 gal of fluid and 26000 gal of a borate crosslinked gelled fluid comprising 25 lbs guar/1000 gal of fluid. The gelled fluids also included 2% by weight KCl, 0.3 lbs/1000 gal of a bactericide, 1 gal/1000 gal of a surfactant, 5 gal/1000 gal of a 25% by weight caustic solution and 1 lb/1000 gal of a breaker. The crosslinked fluid included a total of about 120000 lbs of sand as a proppant in a ramped injection of from 2 to 8 lbs per gal. At the conclusion of the treatment the well was shut in for 48 hours to permit the reactive polymers to polymerize after which it was flowed back and placed on production. After 2 months the well is producing an average of about 125 barrels of oil per day with a water to oil ratio of about 30%. Offset wells without the treatment of the present invention are producing from about 30 to about 60 percent as much oil and have a water to oil ratio of from about 60 to 65%.
Thus, the present invention is well adapted to carry out the objects and attain the benefits and advantages mentioned as well as those which are inherent therein.
EXAMPLE II
The following laboratory flow studies were performed to evaluate the process of the present invention.
Sandstone core samples approximately 10 cm long and 2.38 cm in diameter were sealed into a sleeve having a fluid entry and exit port on opposite ends of the sleeve. A solution of Standard API Brine comprising 9% sodium chloride and 1% calcium chloride by weight is flowed through the cell at a flow rate of 2 to 5 ml/min with a back-pressure of about 100 psi until a relative initial water permeability is established.
Kerosene then is flowed through the core to establish an initial oil permeability. This sequence generally will be repeated three times to establish an average initial permeability. The core then is treated with a quantity of the first and second reactive polymers in a pH adjusted aqueous fluid. After the polymers have been permitted to react, brine and oil permeabilities are again determined by flowing either Standard API Brine or kerosene through the core until a constant permeability is established.
The results of the tests and the concentration of the reactive polymers, solution pH and relative change in permeability for the oil and water flows are set forth below in Table I.
TABLE I______________________________________ Concentration Reactive Permeability,Sample Tempera- Polymers Retained %No. ture pH 1/2, WT. % Water Oil______________________________________1 140 12 2.5/2.5 83 1922 140 12 2.5/2.5 78 2333 140 12 5/5 40 1004 110 9 6.25/6.25 31 845 200 12 5/5 31 586 214 11.5 5/5 6 27______________________________________
The test results demonstrate the ability of the reactive polymers to selectively reduce core permeability to water flow while not preventing oil flow through the various core samples.
While numerous changes to the compositions and methods can be made by those skilled in the art, such changes are encompassed within the spirit of this invention as defined by the appended claims. | The present invention provides a method for reducing the amount of water produced from a subterranean formation as a result of stimulation of the subterranean formation. The method comprises the introduction of a gelled fluid to initiate a fracture in a formation, introduction of a first and second reactive polymer which leak-off into the formation along the fracture and which are capable of subsequently reacting together to form a reaction product which selectively reduces the permeability of the formation to water flow through the formation into the fracture and introduction of a crosslinked gelled fluid to extend the fracture into the formation and facilitate the introduction of a propping agent into the created fracture. The reactive polymers react in situ to form a reaction product that binds to the formation in such a manner that the flow of water is selectively retarded through the matrix while the flow of oil is substantially unaffected. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to a Christmas motion ornament which comprises a fixed table with inanimate toy ornaments disposed above a rotary table with animate toy ornaments, and an AC motor set electrically connected to the AC power supply of the Christmas light sets and controlled to rotate the ornament supported on the rotary table under the fixed table.
A variety of Christmas motion ornaments have been known, and have been appeared on the market. FIG. 12 illustrates a Christmas motion ornament according to the prior art which comprises a rotary table having a bottom gear meshed with a pinion on the output shaft of a motor, a motor cover having an elongated upright rod extended out of the rotary table through a hole thereon, decorative objects and light sets respectively mounted on the rotary table and the upright rod, and a control circuit for controlling the operation of the motor and the decorative light sets. Turning on the motor causes the pinion to drive the bottom gear in turning the rotary table on the upright rod. During the operation of the Christmas motion ornament or upon an impact force, the decorative object on the elongated upright rod may be caused to oscillate, and oscillating the elongated upright rod may cause disengagement of the bottom gear from the pinion. Therefore, this structure of Christmas motion ornament is not stable in function. Further, the control circuit is complicated. It comprises a rectifier circuit consisted of a bridge rectifier and a zener diode to convert AC power supply into DC power supply for the motor, music IC, lamp bulbs, and other electric components. Therefore, the control circuit is expensive to manufacture. When the control circuit is damaged, it is difficult to repair.
FIG. 13 illustrates another structure of prior art Christmas motion ornament which comprises a motor electrically connected to the AC power supply of the Christmas tree light assembly, and an ornament suspended from the hooked output shaft of the motor. Turning on the Christmas tree light assembly causes the motor to turn the ornament round and round. This type of motor can only carry a light ornament having a weight below 17 grams. Further, the suspension string may be tangled during the operation of the motor, thereby causing damage to the motor.
SUMMARY OF THE INVENTION
The present invention eliminates the drawbacks of the aforesaid Christmas motion ornament, The present invention uses a fixed table fastened to a pin dowel on a motor set cover and disposed above the rotary table so that the decorative objects and light sets on the fixed table are kept still while the rotary table with the decorative objects and light sets thereon are being turned under the fixed table.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a Christmas motion ornament constructed according to an embodiment the present invention;
FIG. 2 is an exploded view of the mainframe of a Christmas motion ornament according to the present invention;
FIG. 3 is a top view of the mainframe shown in FIG. 2;
FIG. 4 is a sectional front view of the mainframe shown in FIG. 2;
FIG. 5 illustrates an alternate form of the Christmas motion ornament of the present invention;
FIG. 6 illustrates another alternate form of the Christmas motion ornament of the present invention;
FIG. 7 illustrates still another alternate form of the Christmas motion ornament of the present invention;
FIG. 8 is a perspective exploded view of an AC motor set according to the present invention;
FIG. 9 is a circuit diagram for the AC motor set shown in FIG. 8; and
FIG. 10 is a perspective exploded view of an alternate form of the mainframe;
FIG. 11 is a perspective elevational view of a Christmas motion ornament having the mainframe shown in FIG. 10;
FIG. 12 is a sectional front view of the mainframe of a prior art Christmas motion ornament;
FIG. 13 is a perspective view of another prior art Christmas motion ornament.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1, 2, 3 and 4, a Christmas motion ornament constructed in accordance with the present invention comprises a mainframe consisted of a hollow, semi-spherical shell 1, an AC motor set 2, motor set cover 3, a rotary table 4, and a fixed table 5.
The shell 1 comprises two spaced mounting posts 11, which have each a screw hole 12 at the top, and a wire hole 13 through the center. The AC motor set 2 has two mounting tabs 23 with through holes 231 at two opposite locations respectively supported on the two mounting posts 11, and an output shaft 21 at an eccentric location inserted through an axle hole 34 on the motor set cover 3 and then coupled with a pinion 22 22. The motor set cover 3 has two mounting tabs 32 with through holes 321 aligned at two opposite locations respectively fastened to the mounting tabs 23 on the AC motor set 2 and the mounting posts 11 on the shell 1 by screws 35, two hooks 31 aligned at two opposite locations and respectively spaced from either mounting tab 32 through 90° angle and hooked on the peripheral edge of the AC motor set 2, and a center pin dowel 33. The rotary table 4 is supported above the motor set cover 3, comprising a driving gear 41 meshed with the pinion 22 on the output shaft 21 of the AC motor set 2 and a center hole 411 through which the center pin dowel 33 inserts. The fixed table 5 is relatively smaller than the rotary table 4 and immovably supported above the rotary table 4, having a cap 51 with a pin hole 511 into which the center pin dowel 33 fits. Turning on the AC motor set 2 causes the output shaft 21 to turn the rotary table 4 through the pinion 22 and the driving gear 41.
Referring to FIGS. 5, 6 and 7, different ornaments simulating different inanimate objects, for example: the cottage 52 in FIG. 5, the snowman 53 in FIG. 6, and the opened book 54 in FIG. 7, and different animate objects, for example: the couple 521 in FIG. 5, the pair of children 531 in FIG. 6, and the pair of children 541 in FIG. 7, may be respectively mounted on the fixed table 5 and the rotary table 4. Therefore, the ornament of animate object 521, 531 or 541 is being continuously turned around the ornament of inanimate object 52, 53 or 54 after the motor set 2 has been turned on. These ornaments may be made from transparent materials with lamps fastened on the inside.
Referring to FIG. 8, which shows the exploded perspective view of the aforesaid AC motor set 2, in which multiple parts of the AC motor set 2 is mounted in a metal case 201 covered with an insulated case 202. There is a coil 203 fixed in the metal case 201 to be composed of 600 to 850 turns of thicker winding. A wire 2031 extends out from the metal case and the insulated case is connected with the plug, able to be inserted in the plug socket of a string-set. At the bottom of the metal case 201 several upwardly protruding plates 2011 extending to the center hole 2032 of the coil are set; the protruding plates 2011 and the plates 2041 extending downwardly from the upper metal case 204 from six poles, also known as the outer stator of the motor, which make the coil drive a rotary magnet 205 set in the center hole 2032 after the coil is supplied with power source by the wire 2031. The magnet 205 is a permanent magnet rotor, from the middle of which a rotor spindle 206 extends upwardly and a rotor pinion 2061 engages with a reducing gear set 207. As a result, the number of the revolution of the output rotor spindle 208 set at the end of the reducing gear set can be properly regulated, and thus the rotary spindle 208 for the output power mounted at the end of the reducing gear set can be well accommodated until the output revolution are reasonably demanded for the transmission means mounted on the guard of the upper metal case 209 and the guard of the upper case 69 so that the transmission means can implement multiple-directional movement and drive the doll therefor.
Referring to FIG. 9, where a circuit diagram is shown, the AC motor set 2 are mounted a pair of zener diodes Z1,Z2 connected each other in reverse and connected with the AC motor in parallel so as to control constant voltage of the AC motor set 2; this means that the diodes can serve as a diverter to sustain a constant quantity of current passing through the AC motor and to release the excess current. All this is for keeping normal operation of the motor.
Referring to FIGS. 10 and 11, therein illustrated is an alternate form of the present invention which eliminates the use of the pinion 22 on the output shaft 21 of the AC motor set 2, and the driving gear 41 on the rotary table 4. The output shaft 21 of the AC motor set 2 in this alternate form inserts through an axle hole 42 on the rotary table 4 and directly coupled to the ornament 521;531;541. Therefore, the rotary table 4 is immovable, and the ornament is turned round and round as the AC motor set 2 is turned. | Disclosed is a Christmas motion ornament which includes an AC motor set received inside a hollow, semi-spherical shell, a cover covered on the AC motor set, a rotary table decorated with animate toy ornaments and disposed above the cover and having a bottom gear meshed with a pinion on the output shaft of the AC motor set, and a fixed table decorated with inanimate toy ornaments and fixed to a pin dowel being protruded over the rotary table through a hole thereof. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a new process for the synthesis of the known antibiotic daunomycin and its β-anomer, which is a new compound. The invention also relates to the new compounds: 4'-epidaunomycin α-anomer, 4'-epidaunomycin β-anomer and a mixture thereof as well as a process for preparing same. The new processes for preparing daunomycin and 4'-epidaunomycin involve the preparation and use of certain new intermediates which are also included within the invention. The new compounds of the invention are useful in treating certain tumors in animals.
2. Description of the Prior Art
Daunomycin and its aglycone daunomycinone are well known compounds. They are, for example, described and claimed in British Pat. No. 1,033,383, owned by the unrecorded assignee of this application.
SUMMARY OF THE INVENTION
The present invention provides, in one aspect thereof, a new process for preparing daunomycinone glycosides. More specifically, the invention provides a process, which in one embodiment is used for preparing the known compound daunomycin (IV), i.e., 7-O-(3'-amino-2',3',6'-trideoxy-α-L-lyxohexopyranosyl)-daunomycin-one, ##STR1## and its β-anomer (V), i.e., 7-O-(3'-amino-2',3',6'-trideoxy-β-L-lyohexopyranosyl)-daunomycinone, which is a novel compound ##STR2## as a mixture of the two anomers as well as each anomer separately, by condensing daunomycinone (I) ##STR3## with a reactive protected derivative of daunosamine (II), i.e., 3-amino-2,3,6-trideoxy- L-lyxohexose, to form the glycosidic linkage after which the α- and β-anomers are separated and the protecting groups, i.e., the trifluoroacetyl groups, on the daunosamine are removed. The reactive protected derivative of daunosamine which is condensed with daunomycinone (I) is the novel intermediate 1-chloro-2,3,6-trideoxy-3-trifluoroacetamido-4-trifluoroacetoxy-α-L-lyxohexopyranose (IIB) ##STR4## which is obtained from another novel intermediate, 2,3,6-trideoxy-1-trifluoroacetoxy-3-trifluoroacetamido-4-trifluoroacetoxy-L-lyxohexopyranose (IIA) ##STR5## compound (IIA) being prepared by reaction of daunosamine (II) with trifluoroacetic anhydride.
This same process, in another embodiment is used for preparing the novel antibiotics, 4'-epidaunomycin (VI), i.e., 7-0-(3'-amino-2',3',6'-trideoxy-α-L-arabinohexopyranosyl)-daunomycinone ##STR6## and its β-anomer (VII), i.e., 7-O-(3'-amino-2',3',6'-trideoxy-β-L-arabinohexopyranosyl)-daunomycinone ##STR7## as a mixture of the two anomers as well as each anomer separately. To prepare 4'-epidaunomycin (VI) and its β-anomer (VII), daunomycinone (I) is condensed as described above, with a reactive protected derivative of 4'-epidaunosamine (III), i.e., 3-amino-2,3,6-trideoxy-L-arabinohexose, ##STR8## to form the glycosidic linkage, after which the protecting groups on the 4'-epidaunosamine are removed and the α - and β -anomers are separated. The reactive protected derivative of 4'-epidaunosamine which is condensed with daunomycinone (I) is, in this embodiment, also a novel intermediate, namely, 1-chloro-2,3,6-trideoxy-3-trifluoroacetamido-4-trifluoroacetoxy-α-L-arabinohexopyranose (IIIB) ##STR9## which is obtained from another novel intermediate, 2,3,6-trideoxy-1-trifluoroacetoxy-3-trifluoroacetamido-4-trifluoroacetoxy-L-arabinohexopyranose (IIIA) ##STR10## compound (IIIA) being prepared by reaction of 4'-epidaunosamine (III) with trifluoroacetic anhydride. Thus, it is clear that the only essential difference between the two embodiments is the nature of the starting sugar which is reacted (in the form of a reactive protected derivative) with the aglycone (daunomycinone (I)) to form the glycoside. In one embodiment this sugar has the L-lyxose configuration and in the other it has the L-arabinose configuration.
In another aspect, the invention provides the novel antibiotic end products (V) - daunomycin (β-anomer), (VI) 4'-epidaunomycin (α-anomer) and (VII) 4'-epidaunomycin (β-anomer) as well as the novel intermediates (IIA), (IIB), (IIIA) and (IIIB) which are used in the preparation of daunomycin and the novel end products.
In a further aspect, the invention provides methods of using the novel antibiotic end products (V), (VI) and (VII) in treating various mammalian tumors.
The process of the invention, as stated above, broadly comprises condensing daunomycinone (I) with a derivative of daunosamine (II) or 4'-epidaunosamine (III) to obtain the pharmacologically active glycosides (IV) (daunomycin) and (V) or (VI) and (VII). In practice, the hexose (II) or (III) must first be protected, for example, by forming the trifluoroacetyl derivatives (IIA) and (IIIA) and then converted into reactive derivatives, such as the 1-halides and in particular, the 1-chloro derivatives (IIB) and (IIIB) which are suitable for condensation with daunomycinone (I). After the condensation reaction, the protecting trifluoroacetyl groups are removed. The 4-O-trifluoroacetyl group is firstly removed by treatment with boiling methanol.
The 3-amino groups in the hexoses (II) and (III) must be protected with groups that can subsequently be removed without further decomposition of the products which contain different chemically-sensitive groups. The trifluoroacetyl group meets this criterion since it can be readily removed by mild alkaline treatment.
The hexoses (II) and (III) also have to be converted into reactive derivatives which are sufficiently stable to be used in the condensation reaction with daunomycinone (I). The instability of the 1-halo derivatives of 2-deoxysugars is well documented (W. W. Zorbach et al., Advances in Carbohydrate Chemistry, 1966, 21, 273). However, according to the invention, it has been found that if the 3-amino and the 1- and 4-hydroxy groups of the hexoses (II) and (III) are protected with trifluoroacetyl groups, the tri-trifluoroacetyl derivatives (IIA) and (IIIA) of the hexoses (II) and (III) can then be reacted with anhydrous hydrogen chloride to give the corresponding 1-chloro-hexoses (IIB) and (IIIB). These latter compounds are solid materials which can be stored for several days under anhydrous conditions.
The tri-trifluoroacetyl derivatives (IIA) and (IIIA) are prepared by reacting, under anhydrous conditions, the hexoses (II) and (III), either as such, or as the hydrochloride, with trifluoroacetic anhydride at about 0° C. in an inert solvent such as diethyl ether.
The 1-chloro-derivatives (IIB) and (IIIB) are then prepared by reacting the tri-trifluoroacetyl derivatives (IIA) and (IIIA), under anhydrous conditions, with anhydrous gaseous hydrogen chloride, in an inert solvent, such as diethyl ether, at a temperature of about 0° C.
The reactive 1-chloro derivative (IIB) or (IIIB) is then reacted with daunomycinone (I) to form the glycoside linkage, after which the protecting trifluoroacetyl groups are removed and the product is separated into the respective α- and β-anomers. Alternatively, the α- and β-anomers can be separated before removal of the protecting trifluoroacetyl groups.
The conditions under which th condensation reaction is effected are modifications of the well known Koenigs-Knorr reaction (Conchie et al., Advances in Carbohydrate Chemistry, 1957, 12, 157). This standard reaction contemplates the use of a wide variety of different reaction conditions such as temperature, solvent, catalyst and hydrogen chloride (or bromide) acceptor. However, ordinarily, an optimal set of conditions is necessary to achieve a significant reaction rate. Since the use of the standard Koenigs-Knorr reaction conditions with the 1-halo derivatives of 2-deoxy sugars leads to the unwanted formation of the corresponding glycals (Zorbach et al., supra), it is necessary, according to the present invention, to modify those conditions.
The procedure according to the invention therefore comprises reacting daunomycinone (I) with the 1-chloro-N,O-di-trifluoroacetyl derivative (IIB) or (IIIB) of hexose (II) or (III) in an inert organic solvent such as chloroform or methylene dichloride, under mild conditions, in the presence of a catalyst comprising, a mercuric halide, for example, mercuric bromide and a hydrogen chloride acceptor, for example, mercuric oxide, silver carbonate, silver oxide or cadmium carbonate.
The reaction products are then treated firstly with boiling methanol then with a dilute alkali, such as sodium hydroxide to effect removal of both the O- and N-trifluoroacetyl groups and thereby obtain the final products (IV), (V), (VI) and (VII).
PREPARATION OF THE INTERMEDIATE 2,3,6-TRIDEOXY-3-TRIFLUOROACETAMIDO-L-ARABINO-HEXOPYRANOSE
1.0 g of α-methyl-daunosaminide hydrochloride in 25 ml of ethyl ether was treated with 4 ml of (CF 3 CO) 2 O at 0° C. After 4 hours at room temperature the solution was evaporated to dryness under vacuum and the residue, after complete removal of acidity, was treated with 60 ml of methanol overnight at room temperature. The evaporation of solvent gave 1.3 g of methyl N-trifluoroacetyl daunosaminide: m.p. 108°-109° C.; [α] D 23 -148° (CO.5 CHCl 3 ). The compound was oxidized to the corresponding C-4 keto-derivative as follows. 2.0 g in 40 ml of CH 2 Cl 2 were added to a solution of KIO 4 (2-3 g), K 2 CO 3 (0.25 g) and RuO 2 (0.12 g) in 40 ml of water. The two phase system was shaken overnight at room temperature; further addition of solid KIO 4 (2.3 g), K 2 CO 3 (0.25 g) and RuO 2 (0.12 g) in 6 hours completed the oxidation. The organic layer was separated, filtered, washed, dried and evaporated under reduced pressure to give 1.45 g of methyl 2,3,6-trideoxy-3-trifluoroacetamido-α-L-threo-hexopyranoside-4-ulose: m.p. 77°-80° C.; IR (KB r ): CO Ketone 1735 cm - 1 , CO amide 1700 cm - 1 ; mass spectrum: 255 m/ e (M + ); pmr (CDCl 3 ): 1.31 (d, J 6.5 H z , CH 3 --C--5), 1.89 (m, C--2--Hax), 2.88 (m, C--2--Heq), 3.43 (s, CH 3 O), 4.37 (d, J 6.5 Hz, C--5--H), 4.83 (s, W H 4.5 H z C--1 H), 4.95 (two d, J 12.5 H z , J' 6.0 H z , C--3H) and 7.00δ (broad s, NH). The stereo selective reduction with NaBH 4 of the keto derivative gave methyl 2,3,6-trideoxy-3-trifluoroacetamido-α-L-arabinopyranoside as follows. The solution of keto derivative (g 1.0) in a mixture of 100 ml of dioxan and 10 ml of water, was treated with 0.1 g of NaBH 4 at 5° C. After 10 minutes, the reduction was completed, then the solution was adjusted to pH 4 with resin Dowex W - X2 (H + ). The suspension was filtered and evaporation of solvents gave a crude product which was treated several times with methanol in order to remove boric acid. 0.65 G of arabino-derivative were obtained: m.p. 195°-197° C.; [α] D 23 -110° (c 0.2 MeOH); pmr (DMSO--d 6 ): 1.07 (d, J 6.0 H z , CH 3 --C--5), 1.5-1.9 (m, C--2--H 2 ), 3.0 (two d [after exchange with D 2 O], J'=J"=9.5 H z , C-- 4 H), 3.16 (s, CH 3 O), 3.44 (two q, J'9.5 H z , J" 6.0 H z C--5H), 3.87 (m, C--3H), 4.48 (s, W H 6.0 C--1 H), 4.84 (d, J 6.5 H z C--OH) and 8.84δ (broad s, NH). Finally the hydrolysis of the methyl glycoside (1 g) was performed in 20% aqueous acetic acid at 100° C. for 2 hours. Evaporation of the acid under vacuum gave a solid product which, by crystallization from CH 3 OH-CH 2 Cl 2 (1:3 by vol)-gave 0.6 g of 2,3,6-trideoxy-3-trifluoroacetamido-L-arabinohexopyranose: m.p. 202° C. (dec.); [α] D 23 -51°, after 2 hours -33.4° (C 0.5 dioxane).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following examples are given to illustrate the invention without, however being a limitation thereof. All parts given are by weight unless otherwise indicated.
EXAMPLE 1
PREPARATION OF 2,3,6-TRIDEOXY-1 -TRIFLUOROACETOXY3-TRIFLUOROACETAMIDO- 4-TRIFLUOROACETOXY-L-LYXOHEXOPYRANOSE (IIA)
One gram of daunosamine (II) hydrochloride was suspended in anhydrous diethyl ether and treated at 0° C. with 8 ml of trifluoroacetic anhydride. After allowing the suspension to stand for 2 hours at 0° C. and 1 hour at room temperature, the solvent ws removed under reduced pressure and the residue was crystallized from dichloromethane to yield 1.1 g of (IIA), having a m.p. of 132°-134° C. and a mass spectrum m/e 391 (M-44), 322 (M-113).
EXAMPLE 2
PREPARATION OF 1-CHLORO-2,3,6-TRIDEOXY-3 -TRIFLUOROACETAMIDO-4-TRIFLUOROACETOXY-α -L-LYXOHEXOPYRANOSE (IIB)
0.5 g of (IIA), prepared as in Example 1, was treated in anhydrous diethyl ether at 0° C. with anhydrous gaseous hydrogen chloride. After standing at +5° C. overnight, the solvent was removed in vacuo to yield (IIB) as a crystalline product. The NMR spectrum in CDCl 3 was as follows:
1.22 δ (d, J = 6.5 Hz, 3H, CH 3 ),
2.05-2.70 δ (m, 2H, C(2)H 2 ),
4.46 δ (dq, J = 6.5 Hz and J<1Hz, 1H, C(5)H),
4.60-5.10 δ (m, 1H, C(3)H),
5.37 δ (c, W H = 6.0 Hz, 1H C(4)H),
6.29 δ (m, W H = 6.5 Hz, 1H, C(1)H), and
6.37 δ (broad s, 1H, NH).
EXAMPLE 3
PREPARATION OF DAUNOMYCIN (IV) AND ITS β-ANOMER (V)
300 mg. (0.75 mmol) of finely powdered daunomycinone (I) were dissolved in 75 ml. of anhydrous chloroform and treated with 600 mg. of mercuric oxide, 150 mg. of mercuric bromide and molecular sieve (3A, Merck).
The resulting suspension was stirred for 1 hour and then 600 mg. of (IIB) were added.
The reaction mixture was stirred at room temperature for 64 hours, and then filtered. The solution was then evaporated in vacuo. The residue was taken up in 200 ml. of methanol and refluxed for 15 minutes. The residue which remained after removal of the solvent was chromatographed on a silicic acid column using a mixture of chloroform:benzene:methanol 100:20:3 (by vol.) as the eluent.
In addition to unreacted daunomycinone (I), there were obtained the following:
220 mg. of N-trifluoroacetyl daunomycin (α isomer) m.p. 169°-171° C. (after recrystallization from tetrahydrofuran and hexane), and 20 mg. of N-trifluoroacetyl daunomycin (β isomer), m.p. 138°-140° [α] D 23 + 440° (c 0.1 chloroform). 0.20 gm. of N-trifluoroacetyl daunomycin (α isomer) was dissolved in 20 ml. of 0.1 N aqueous sodium hydroxide. The resulting solution, after standing 30 minutes at room temperature was treated with 0.1 N aqueous hydrogen chloride to bring the pH to 8.6, and repeatedly extracted with chloroform.
The combined chloroform extracts were dried over anhydrous sodium sulphate, concentrated to a small volume and acidified to pH 4.5 with 0.1 N methanolic hydrogen chloride to allow crystallization of the daunomycin (IV) hydrochloride. The product was identical in all respects with the product obtained by fermentation (see F. Arcamone et al., Gazzetta Chimica Italiana, 1970, 100, 949), and the yield was practically quantitative. The β-isomer of N-trifluoroacetyl daunomycin can be treated in the same manner to obtain the free β-anomer of daunomycin (V).
EXAMPLE 4
PREPARATION OF 2,3,6-TRIDEOXY-1-TRIFLUOROACETOXY-3-TRIFLUOROACETAMIDO-4-TRIFLUOROACETOXY-L-ARABINOHEXOPYRANOSE (IIIA)
One gram of 2,3,6-trideoxy-3-trifluoroacetamido-L-arabinohexopyranose was suspended in 20 ml. of anhydrous diethyl ether and treated at 0° C. with trifluoroacetic anhydride. After allowing the suspension to stand for 2 hours at 0° C. and 1 hour at room temperature, the solvent was removed under reduced pressure and the residue crystallized from dichloromethane to yield (IIIA).
EXAMPLE 5
PREPARATION OF 1-CHLORO-2,3,6-TRIDEOXY-3-TRIFLUOROACETAMIDO-4-TRIFLUOROACETOXY-α-L-ARABINOHEXOPYRANOSE (IIIB)
Compound (IIIA) obtained as described in Example 4 was treated with anhydrous gaseous hydrogen chloride as described in Example 2 to give a quantitative yield of (IIIB). The NMR spectrum of (IIIB) in CDCl 3 was as follows:
1.30 δ (d, J = 6.0 Hz 3H, CH 3 ),
2.25--2.80 δ (m, 2H, C(2)H 2 ),
4.20-4.65 δ (m, 1H, C(5)H),
4.65-5.15 δ (m, 2H, C(3)H and C(4)H),
6.25 δ (m, W H = 6.0 Hz, 1H, C(1)H), and
6.45 δ (broad s, 1H, NH).
EXAMPLE 6
PREPARATION OF 4'-EPIDAUNOMYCIN (VI) AND ITS β-ANOMER (VII)
A solution of 0.5 gm. of daunomycinone (I) in anhydrous chloroform was treated with 1 gm. of mercuric oxide, 0.25 gm. of mercuric bromide, 10 gm. of molecular sieve (3A, Merck), and 0.5 gm. of (IIIB). The mixture was stirred for 24 hours, freed from solids by filtration, and the filtrate evaporated under vacuum. The residue was taken up in methanol refluxed for 15 minutes, evaporated to dryness and chromatographed on a silicic acid column using a mixture of chloroform:benzene:methanol 10:20:3 (vol.) as the eluent. The main product which was obtained is a mixture, in the ratio 70:30 (weight) of α- and β-7-O-(N-trifluoroacetyl-4'-epidaunosaminyl)-daunomycinone (yield after crystallization from chloroform: 0.3 g). This material, upon treatment with 0.1 N sodium hydroxide as described in Example 3, was converted quantitatively into a mixture of the corresponding α- and β-glycosides (VI) and (VII) in the form of the free bases. The product was separated into the α- and β-anomers by silica gel chromatography using a chloroform:methanol:water 135:20:2 (by vol.) solvent system as the eluent. There was obtained 0.16 gm. of α-anomer-4'-epidaunomycin (VI), [α] D 23 +320° (c = 0.045, methanol), m.p. 199°-201°, and 0.06 gm. of β-anomer (VII), m.p. 182°-184°,[α] D 20 + 357° (c= 0.02 MeOH).
BIOLOGICAL ACTIVITY
The antitumor activity of the novel antibiotic compounds of the invention, i.e., 4'-epi-daunomycin (VI) and 4'-epidaunomycin, β-anomer, (VII) was evaluated on several transplanted tumors in mice, and in in vitro tests, in comparison with the known antitumor agent daunomycin (IV). The results of these tests are given in the following tables.
BIOLOGICAL ACTIVITY OF 4'-EPIDAUNOMYCIN (VI) AND 4'-EPIDAUNOMYCIN β-ANOMER (VII).
Compounds (VI) and (VII) display outstanding biological properties as powerful inhibitors of cell mitosis and proliferative activity in cultured cells in vitro. They also have substantial activity on cell transformation induced by oncogenic viruses, as well as antitumor activity in mice, as shown by an increase in the mean survival time at non-toxic doses in test animals bearing a number of experimental tumors.
ASCITES SARCOMA 180
The tests were carried out on groups of 10 female mice (Swiss CD 1). The compounds under examination were administered intraperitoneally in varying doses to the test animals 1 day after intraperitoneal inoculation with 1 × 10 6 tumor cells per animal. The average survival time is given in Table 1 as a percentage of the survival time of untreated animals, which is arbitrarily designated as 100%. Also given in Table 1 are the number of long term survivors.
TABLE 1______________________________________ACTION ON ASCITES SARCOMA 180 Dose Average Survival Long Term Surviv-Compound (mg/kg) time (%) ors after 60 days______________________________________Control -- 100 04'-epidauno- 0.22 111.1 1/10mycin α- 1.1 120.8 1/10anomer (VI) 5.7 174.5 0/104'-epidauno- 0.26 96.6 0/10mycin β- 1.3 114.8 1/10anomer (VII) 6.7 118.6 1/10______________________________________ 6/10 of the test animals died as a result of drug toxicity
TRANSPLANTED GROSS LEUKEMIA
Inbred C 3 H female mice were intravenously inoculated with a suspension of leukemia lymphonodes and spleen cells (2.5 × 10 6 leukemia cells/mouse) and treated, intravenously, from the first to the fifth day after inoculation with the compounds under examination. The average survival time percentage is given in Table 2.
TABLE 2______________________________________ Daily dosage Average SurvivalCompound (mg/kg) Time (%)______________________________________Control 0 1004'-epidaunomycin 1.5 115α-anomer (VI) 2.25 143 3 162 3.75 122 4.5 1204'-epidaunomycin 1.5 106β-anomer (VII) 2.25 102 3 121______________________________________
TESTS IN VITRO ON THE FORMATION OF FOCI BY MOLONEY SARCOMA VIRUS (MSV.).
The test compounds were evaluated on mouse embryo fibroblast cultures infected with MSV. After a treatment of three days, the inhibiting doses (ID 50 ) were evaluated on cell proliferation and on MSV foci formation. The results obtained are given in Table 3.
TABLE 3
Effect of compounds (VI and (VII) on foci formation and on cell proliferation in cultured mice fibroblasts infected with Moloney Sarcoma Virus. (3 days treatment)
TABLE 3______________________________________ Foci Cell Formation Proliferation ID.sub.50 ID.sub.50 Dose (% of (μg/ (% of (μg/ (μg/ con- ml) con- ml)Compound ml) trols) (A) trols) (B) B/A______________________________________4'-epidaun- 0.0062 51 75omycinα- 0.025 0 0.006 23 0.013 2.1anomer (VI) 0.1 0 14 0.4 0 14'-epidaun- 0.0062 48 87omycin β- 0.025 44 0.01 80 0.064 6.4anomer 0.1 5 28(VII) 0.4 0 14Daunomycin 0.006 0.0086 1.4(IV)______________________________________
TABLE 4
Tests in vitro on the effect of compounds (VI) and (VII) on the micotic index and the proliferative activity of cultured HeLa cells at different exposure times. The results in Table 4 are expressed as a percent of the untreated controls. The ID 50 represents the dose which gives a 50% inhibition of colonies.
TABLE 4______________________________________ Dose (μg/ Micotic Index Colony CountsCompound ml) 2h 4h 8h 2h 8h 24h______________________________________4'-epidaun- 0.025 226* 100 117 113 88 48omycin α- 0.05 189* 103 122 115 56 23anomer (VI) 0.1 79 140 0 77 23 3 ID.sub.50 0.16 0.056 0.0274'-epidaun- 0.25 137 103 85 108 86 70omycin β- 0.5 95 67 88 101 37 18anomer 1 52 40 0 98 17 6(VII) ID.sub.50 >1 0.47 0.33Daunomycin ID.sub.50 0.098 0.036 0.021IV______________________________________ *Metaphasic block.
TESTS IN VITRO ON THE CARDIOTOXIC ACTIVITY
The cardiotoxic activity of compound (VI) was evaluated in vitro on single myocardial cells isolated by trypsinization from the hearts of newborn mice (Necco A., Dasdia T. IRCS, 2: 1293, 1974). After 3-4 days, the cell cultures, showing clusters of beating cells, are studied both as to frequency and rhythym.
The cardiotoxic activity of compound (VI) - 4'-epidaunomycin, α-anomer, was found to be lower than that of daunomycin (IV).
Variations and modifications, can of course, be made without departing from the spirit and scope of the invention. | The known antibiotic daunomycin, and the novel compounds daunomycin-β-anomer and 4'-epidaunomycin (both α- and β-anomers) are prepared by condensing daunomycinone with reactive novel intermediates which are 1-chloro-2,3,6-trideoxy-3-trifluoroacetamido-4-trifluoroacetoxy-α-L-lyxo (or arabino) hexopyranoses. | 2 |
FIELD OF THE INVENTION
The present invention relates generally to electric machines, and more particularly to doubly salient machines having stator teeth with angled permanent magnets therein.
BACKGROUND OF THE INVENTION
A variety of permanent magnet machines, including doubly salient machines, are known in the art in which permanent magnets are positioned within the frame or back iron of a stator. This is typically done to accommodate relatively large magnets capable of producing significant flux. As recognized by the inventor, however, positioning magnets in the stator frame tends to weaken the stator structure, including along those portions where the stator teeth meet the stator frame, and often leads to acoustic noise problems. In many designs, permanent magnets are associated with each stator pole, often with an alternating polarity for each adjacent stator tooth. As recognized by the inventor, however, such a configuration requires an excessive number of permanent magnets as well as a relatively complex device for magnetizing the stator magnets, thus increasing the complexity and manufacturing cost of the permanent magnet machine.
SUMMARY OF THE INVENTION
In order to solve these and other needs in the art, the inventor hereof has succeeded at designing and developing permanent magnet machines, including doubly salient machines, having one or more permanent magnets located at least partly and preferably entirely within the stator teeth, thereby avoiding weakening of the stator back iron structure while reducing acoustic noise. In one embodiment, permanent magnets are located in only a subset of the stator teeth, thereby lowering magnet material and manufacturing costs. In another embodiment, all such magnets are oriented with their north poles facing inwardly (i.e., toward an interior of the machine), resulting in reduced cogging and negative torques with an improved torque density. The permanent magnets may also extend within the stator teeth on an angle or diagonal, thereby allowing use of magnets which are wider than the teeth themselves to produce greater flux. Further, a magnetizing device having a single coil may be used to readily and simultaneously magnetize all the stator magnets with a common polarity.
In accordance with one aspect of the present invention, a stator for use in a permanent magnet machine includes a frame having an outer peripheral edge and an inner peripheral edge extending about a central axis, a plurality of stator teeth each extending along a radial axis from the frame's inner peripheral edge toward the central axis, and at least one permanent magnet located at least partly within one of the stator teeth, wherein said one permanent magnet is oriented at an oblique angle relative to the radial axis along which said one of the stator teeth extends.
In accordance with another aspect of the invention, a stator for use in a permanent magnet machine includes a frame having an outer peripheral edge and an inner peripheral edge extending about a central axis, a plurality of permanent magnets each having inwardly facing north poles, a first plurality of stator teeth each extending along a radial axis from the frame's inner peripheral edge toward the central axis, and a second plurality of stator teeth extending from the frame's inner peripheral edge toward the central axis. Each of the first plurality of stator teeth has one of the permanent magnets located at least partly therein, while the second plurality of stator teeth each have no permanent magnets located therein. The first plurality of stator teeth are each positioned directly between two of the second plurality of stator teeth. The north poles of the permanent magnets are each oriented at an oblique angle relative to the radial axis along which its corresponding one of the stator teeth extends. Each permanent magnet and its corresponding one of the stator teeth has a width extending in a direction of rotation of a rotor when the rotor is mounted for rotation about the central axis. The width of each permanent magnet is greater than the width of its corresponding one of the stator teeth.
In accordance with a further aspect of the invention, a permanent magnet machine includes a stator of the type described herein.
In accordance with yet another aspect of the invention, a method is provided for magnetizing a stator of an electric machine having a plurality of stator teeth spaced about a central axis, and a plurality of magnets, using a magnetizing device which includes a post and a coil extending around a central axis. The method includes positioning the stator relative to the magnetizing device with the central axis of the stator generally parallel to the central axis of the coil, and with the post extending adjacent the plurality of stator teeth, and energizing the coil to induce flux through the post, through at least some of the stator teeth, and through at least some of the magnets to thereby magnetize at least some of the magnets.
While some of the principal features and advantages of the invention have been described above, a greater and more thorough understanding of the invention may be attained by referring to the drawings and the detailed description of preferred embodiments which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a doubly salient machine according to one embodiment in which permanent magnets are positioned within the stator teeth.
FIG. 2 illustrates torque curves for the doubly salient machine of FIG. 1 .
FIG. 3A illustrates a prior art switched reluctance motor having no stator magnets.
FIG. 3B illustrates a torque curve for the conventional switched reluctance motor of FIG. 3 A.
FIG. 4 is a cross-sectional view of a doubly salient machine having permanent magnets in only every other stator tooth.
FIG. 5 illustrates torque curves for the doubly salient machine of FIG. 4 .
FIG. 6 illustrates an exemplary stator coil for the doubly salient machine of FIG. 4 .
FIG. 7A illustrates a device for magnetizing the stator of FIG. 4 .
FIG. 7B is a cross-sectional view of the magnetizing device of FIG. 7 A.
FIG. 8 is a cross-sectional view of a doubly salient machine having north magnets in several adjacent stator teeth.
FIG. 9 is a cross-sectional view of a doubly salient machine having permanent magnets extending diagonally within stator teeth.
FIG. 10 illustrates one alternative to the machine of FIG. 9 in which the permanent magnets extend into the stator frame.
FIG. 11 illustrates another alternative to the machine of FIG. 9 in which notches are formed adjacent to one side of each magnet-bearing stator tooth.
FIG. 12 illustrates preferred profiles for the magnet-bearing and non-magnet-bearing stator teeth of the machine of FIG. 11 .
FIGS. 13A-D compare torque curves for the machine of FIG. 11 with those of a prior art switched reluctance motor.
Corresponding reference characters indicate corresponding features throughout the several views of the drawings.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A doubly salient machine according to one embodiment of the present invention is illustrated in FIG. 1 and indicated generally by reference character 100 . As shown in FIG. 1, the machine 100 includes a rotating member/rotor 102 mounted for rotation about a central axis 104 , and a stationary member/stator 106 extending about the rotor 102 in a magnetically coupled relation. The stator 106 includes a frame 108 (also referred to as the “back iron”) having an outer peripheral edge 110 and an inner peripheral edge 112 extending about the central axis 104 . The stator 106 also includes several salient stator poles/teeth 114 - 136 which extend from the inner peripheral edge 112 toward the central axis 104 , and which are spaced at equal angular intervals around the central axis 104 to form an equal number of slots spaced at equal angular intervals around the central axis 104 . The rotor 102 includes several salient rotor poles/teeth 140 - 154 which extend outwardly relative to the central axis 104 , and which are spaced at equal angular intervals about the central axis 104 , as shown in FIG. 1 . The machine 100 is doubly salient in the sense that salient teeth are provided on both the rotor 102 and the stator 106 .
Similar to the prior art, the stator teeth 114 - 136 each have a permanent magnet 156 - 178 associated therewith, with the permanent magnets alternating between north magnets (i.e., magnets having their north poles oriented toward the central axis 104 ) and south magnets (i.e., magnets having their south poles oriented toward the central axis 104 ) for each successive stator tooth, as shown in FIG. 1 . Exemplary permanent magnet 156 , like the other permanent magnets 158 - 178 , is oriented at a generally perpendicular angle relative to a radial axis 179 along which its corresponding stator tooth 114 extends, and is preferably located adjacent to a distal end 180 of its corresponding stator tooth 114 . Thin short circuit regions 181 , 183 are preferably formed in the stator tooth 114 adjacent to ends 182 , 184 of exemplary magnet 156 . As is known, these regions 181 , 183 are sufficiently thin (in a direction of rotation of the rotor 102 , for the embodiment of FIG. 1) so as to minimize leakage flux and shorting of the exemplary magnet 156 .
Unlike the prior art, the permanent magnets 156 - 178 of FIG. 1 are located entirely within the stator teeth, in contrast to being partially or entirely located within the frame 108 . Positioning the permanent magnets 156 - 178 entirely within the stator teeth 114 - 136 , rather than in the frame 108 , strengthens the stator teeth where they meet the frame, especially in the case where the stator 106 employs a laminate construction. Positioning the permanent magnets in the stator teeth also raises their operating lines, especially when the salient poles of the rotor do not align with those of the stator, thus allowing the magnets to operate without demagnetizing, and provides additional coil space as well.
The machine 100 of FIG. 1 operates using reluctance torque for rotating the rotor 102 , as is known. Although there are preferably no permanent magnets or coils on the rotor 102 , appropriately energizing the stator coils (not shown in FIG. 1) induces a magnetic orientation in the stator 106 and in the rotor 102 (which is a ferromagnetic material) so as to maximize their flux condition, thereby causing alignment of stator and rotor poles via rotation of the rotor 102 . A representative stator coil 600 is shown in FIG. 6, and is preferably excited such that it induces flux in the same direction as does its corresponding magnet (which, for the exemplary magnet shown in FIG. 6, is toward the central axis). A similar coil is preferably provided for each of the magnet-bearing stator teeth 114 - 136 shown in FIG. 1 . These stator coils may be electrically connected in series, in parallel, or in a series-parallel arrangement as desired for any given application of the invention. The machine 100 can advantageously employ a unipolar drive (i.e., a drive employing only non-negative currents).
FIG. 2 illustrates a series of torque curves for the machine 100 shown in FIG. 1 when driven by unipolar currents of zero, two and six amps. As shown in FIG. 2, the machine 100 produces significant negative torque at each current level, which obviously detracts from average torque levels. Nevertheless, average torque levels approximate those produced by a conventional switched reluctance motor of comparable size, shown in FIG. 3A, for which torque curves are provided in FIG. 3 B.
FIG. 4 illustrates a doubly salient machine 200 according to another embodiment of the invention. Similar to the machine 100 shown in FIG. 1, the machine 200 includes a stator 206 having a frame 208 from which several salient stator teeth 214 - 236 extend, with north magnets 256 - 266 located entirely within every other stator tooth 214 , 218 , 222 , 226 , 230 , 234 . However, no magnets are positioned in the remaining stator teeth 216 , 220 , 224 , 228 , 232 , 236 . In other words, the machine 200 of FIG. 4 includes N stator teeth, and M magnets, where M and N are both integers, and where M<N and, more specifically, where M=N/2. Thus, the machine 200 contains only half the magnets of the machine 100 of FIG. 1, thereby reducing costs and simplifying construction. Further, by eliminating the south magnets 158 , 162 , 166 , 170 , 174 , 178 employed in the machine 100 of FIG. 1, the machine 200 of FIG. 4 has a reduced cogging torque and reduced negative torque, thereby yielding an improved torque density. The machine 200 of FIG. 4 is also more readily magnetized, as further explained below. Like the machine 100 of FIG. 1, the machine 200 can advantageously employ a unipolar drive.
FIG. 5 illustrates a series of torque curves for the machine 200 of FIG. 4 when driven by unipolar currents of zero, two and six amps. As shown in FIG. 5, the machine 200 produces average torque levels which are higher than those produced by the conventional switched reluctance motor of FIG. 3A, for which torque curves are provided in FIG. 3 B. The machine 200 also produces significantly less negative torque than the machine 100 of FIG. 1, thereby enhancing average torque levels. As can be seen in FIG. 5, the machine 200 also produces significantly more positive torque than the machine 100 of FIG. 1 .
FIGS. 7A and 7B illustrate a preferred device 700 for magnetizing the stator 206 of FIG. 4 . As best shown in FIG. 7B, the device 700 includes a preferably cylindrical post 702 and a single robust coil 704 extending about a central axis 706 and through a non-magnetic region 705 of the device 700 . The device 700 preferably also includes a support surface 708 for supporting the stator 206 (shown in phantom), as well as an outer peripheral wall 710 . To magnetize the magnets 256 - 266 in the stator 206 , the stator is first positioned relative to the device 700 with the stator's central axis 104 generally parallel and, more preferably, coaxial with the central axis 706 of the coil 704 , and with the post 702 extending adjacent to the stator teeth 214 - 236 , preferably with the stator 206 supported by the support surface 708 , as best shown in FIG. 7 B. The single coil 704 is then energized, thus inducing flux to pass up through the post 702 , across air gaps 714 - 736 , through the stator teeth 214 - 236 (including through the magnets 256 - 266 ), down through the outer peripheral wall 710 , and back to the single coil 704 , as indicated generally by arrows 740 , 742 in FIG. 7B (assuming the coil 704 is energized so as to effectively render the post 702 a north pole; otherwise, the direction of arrows 740 , 742 would be reversed). In this manner, the magnets 256 - 266 in the stator 206 can be readily and simultaneously magnetized with a common polarity. The device of FIG. 7 may also be used to magnetize stators according to other embodiments of the invention, including those described below with reference to FIGS. 8-11.
FIG. 8 illustrates a machine 300 according to another embodiment of the invention in which only north magnets 356 - 366 are employed. As shown therein, three adjacent stator teeth 314 - 318 each have north magnets 356 - 360 located entirely therein, followed by three stator teeth 320 - 324 having no permanent magnets, and so on. Though suitable for certain applications, the machine 300 of FIG. 8 produces more torque ripple, a higher cogging torque and less torque density than the machine 200 of FIG. 4 .
FIG. 9 illustrates a doubly salient machine 400 according to another embodiment of the invention. The machine 400 is much like the machine 200 of FIG. 4, in that north magnets 456 - 466 are positioned entirely within every other stator tooth 414 , 416 , 422 , 426 , 430 , 434 with no magnets provided in intervening stator teeth 416 , 420 , 424 , 428 , 432 , 436 . However, exemplary magnet 456 , like the other permanent magnets 458 - 466 , has its north pole oriented at an oblique (i.e., non-perpendicular) angle relative to the radial axis 479 along which its corresponding stator tooth 414 extends. This allows wider magnets to be employed in the stator teeth, as compared to the magnets employed in the machine 200 of FIG. 4 . Thus, as shown in FIG. 9, exemplary magnet 458 has a width 492 that is greater than a width 494 of the corresponding stator tooth 418 in which it is located. Consequently, the magnets 456 - 466 employed in the machine 400 of FIG. 9 have more surface area than the magnets 256 - 266 employed in the machine 200 of FIG. 4, allowing them to produce more flux. At the same time, the magnets 456 - 466 are still positioned entirely within the stator teeth 414 , 418 , 422 , 426 , 430 , 434 , as shown in FIG. 9, so as to avoid the disadvantages associated with magnets extending in the frame. With reference to another exemplary magnet 460 , note that its ends 468 , 469 are generally parallel to sides 470 , 471 of its corresponding stator tooth 422 , with thin short circuit regions 472 , 473 provided between the ends 468 , 469 and the sides 470 , 471 .
FIG. 10 illustrates a doubly salient machine 500 according to another embodiment of the invention in which magnets 556 - 566 extend from within stator teeth 514 , 518 , 522 , 526 , 530 , 534 into frame 508 such that the surface area of the magnets 556 - 566 is further increased, as compared to the magnets 456 - 466 of FIG. 9, with a further increase in produced flux. Note that, in FIG. 10, one end 570 of exemplary magnet 558 , which extends into the frame 508 , is bent so as to form a thin short circuit region 571 between that end 570 of the magnet and the inner peripheral edge 512 of the stator 506 . The other end 572 of the exemplary magnet 558 is also bent so as to form a short tip 573 which extends from the bend toward the central axis 104 . This magnet configuration incrementally increases the surface area of the magnets 556 - 566 , again increasing the amount of flux produced. However, because the magnets 556 - 566 of FIG. 10 extend partly into the frame 508 , the strength of the stator teeth 514 , 518 , 522 , 526 , 530 , 534 where they meet the frame 508 is reduced, and the amount of acoustic noise generated is increased, as compared to the machine 400 of FIG. 9 .
FIG. 11 illustrates a doubly salient machine 600 according to still another embodiment of the present invention. This machine 600 incorporates the advantages of the machine 400 of FIG. 9, in which angled magnets are positioning entirely within the stator teeth, and the advantages of the machine 500 of FIG. 10, which employs magnets having greater surface areas than those of FIG. 9 at the expense of having such magnets extend into the stator frame 508 . As shown in FIG. 11, notches 668 - 678 are provided adjacent to one side of each stator tooth 614 , 618 , 622 , 626 , 630 , 634 in which a north magnet 656 - 667 is positioned. The notches 668 - 678 extend from the inner peripheral edge 612 of the stator 606 into the frame 608 , and essentially increase the length of such stator teeth 614 , 618 , 622 , 626 , 630 , 634 on one side thereof. This allows the magnets 656 - 667 , which have a greater width than those of FIG. 9, to be employed while at the same time preventing such magnets from extending into the frame 608 . Thus, the magnets 656 - 667 of FIG. 11 produce more flux than those of FIG. 9, but the machine 600 of FIG. 11 produces acoustic noise levels below those of the machine 500 of FIG. 10 . Note that exemplary notch 668 forms a thin short circuit region 679 adjacent one end 680 of the exemplary magnet 656 , which would otherwise (i.e., in the absence of the exemplary notch 668 ) extend into the stator frame 608 .
Note that torque curves for the machines of FIGS. 9-11 are shaped generally the same as those shown in FIG. 5 for the machine 400 of FIG. 4 . However, the positive and negative torque levels for the machines of FIGS. 9-11 are somewhat greater than those of FIG. 5 due to the increased magnet areas employed in FIGS. 9-11.
With further reference to FIG. 11, the magnet-bearing stator teeth 614 , 618 , 622 , 626 , 630 , 634 and the non-magnet-bearing stator teeth 616 , 620 , 624 , 628 , 632 , 636 are preferably shaped differently to further reduce noise. This is shown more clearly in FIG. 12, which depicts a profile 750 for one of the magnet-bearing stator teeth of FIG. 11 superimposed over a profile 760 (shown in phantom) for one of the non-magnet-bearing stator teeth of FIG. 11 . As shown in FIG. 12, the profile 750 for the magnet-bearing stator teeth extends in a generally circumferential direction relative to the central axis 104 , including along its end regions 752 , 754 . In contrast, the profile 760 for the non-magnet-bearing stator teeth has end regions 762 , 764 which taper inwardly toward the inner peripheral edge 612 . As a result, air gaps formed between the end regions 762 , 764 of the non-magnet-bearing stator teeth and the rotor teeth are greater than air gaps formed between the end regions 752 , 754 of the magnet-bearing stator teeth and the rotor teeth. As discovered by the inventor, this markedly reduces the acoustic noise generated by the machine 600 . The non-magnet-bearing stator teeth in other embodiments of the invention, including those shown in FIGS. 4, 8 , 9 and 10 , may also embody end regions which taper inwardly toward the inner peripheral edge of the stator frame to a greater extent than do end regions of the magnet-bearing-stator teeth (if at all) so as to provide a different air gap profile, which reduces noise.
FIGS. 13A-D compare torque curves for the machine 600 of FIG. 11 and a comparably sized conventional switched reluctance motor when the motors are driven at unipolar currents of 2.2, 4.5, 5.5 and 6.4 amps, respectively. As shown in FIGS. 13A-D, the machine 600 of FIG. 11 produces significantly more torque at each current level. The machine 600 of FIG. 11 also has an improved torque density as compared to a conventional switched reluctance motor of comparable size, thus providing more torque for a given motor size, and an improved torque density for a given speed. Further, the machine of FIG. 11 (as well as other embodiments of the invention) has a wide speed range/constant power range. Accordingly, the teachings of the present invention are applicable to a substantial number of electric motor applications, including but not limited to those requiring wide speed ranges such as, e.g., electric vehicles.
Although not shown in FIGS. 4, 8 and 9 - 11 , the magnet-bearing stator teeth shown therein each preferably employ a stator coil of the type shown in FIG. 6, and these coils are all preferably excited in such a manner as to align each coil with its corresponding magnet's polarity.
The exemplary embodiments of the invention described herein and shown in the drawings all employ block magnets, which are generally less expensive than, e.g., arc magnets. It should be understood, however, that a wide variety of magnets may be employed without departing from the scope of the invention. Further, while these exemplary embodiments all employ a stator having twelve salient stator poles/teeth and a rotor having eight salient rotor poles/teeth, the invention is not so limited, as will be apparent to those skilled in the art.
As noted above, the exemplary embodiments of the invention described herein can each be driven with unipolar currents, in contrast to bipolar currents such as those used in most brushless permanent magnet (“BPM”) machines. With many embodiments of the invention, employing a unipolar drive ensures that the flow of current is always in a direction to assist the permanent magnets, thereby minimizing or eliminating demagnetization issues.
When introducing features of the present invention or the preferred embodiments thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more such features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional features beyond those noted.
As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. | Permanent magnet machines including doubly salient machines having one or more permanent magnets located at least partly and preferably entirely within the stator teeth, thereby avoiding weakening of the stator structure while reducing acoustic noise. The magnets may be located in only a subset of the stator teeth, thereby lowering magnet material and manufacturing costs, and all such magnets may have north poles directed toward an interior of the machine, resulting in reduced cogging and negative torques with improved torque densities. The permanent magnets may also extend within the stator teeth on an angle or diagonal, thereby allowing use of magnets which are wider than the teeth themselves to produce greater flux. Further, a magnetizing device having a single coil may be used to simultaneously magnetize all the stator magnets with a common polarity. | 7 |
DETAILED DESCRIPTION OF THE INVENTION
Monomers (m2), (m3), and (m4)
Monomers (m2) are known. Examples include cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, and 4-methylcyclohexyl (meth)acrylate.
The following are examples of monomers (m3): dialkylaminoalkyl (meth)acrylates, such as N,N-dimethylaminopropyl (meth)acrylate, N,N-dimethylaminobutyl (meth)acrylate, N,N-diethylaminopropyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, or preferably N,N-dimethylaminoethyl (meth)acrylate; dialkylaminoalkyl(meth)acrylamides, such as N,N-diethylaminoethyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, N,N-diethylaminobutyl(meth)acrylamide or preferably N,N-dimethylaminoethyl(meth)acrylamide; alkyl (meth)acrylates, or alkyl(meth)acrylamides with heterocycles as substituents, which have at least a nitrogen and/or oxygen atom in the heterocycle, such as furfuryl (meth)acrylate, tetrahydrohydrofurfuryl (meth)acrylate, 2,2,6,6-tetramethylpiperidinyl (meth)acrylate, 2-N-morpholinoethyl (meth)acrylate, 2-N-pyridinylethyl (meth)acrylate or 2-N-piperazinylethyl (meth)acrylate, and N-(4-morpholinomethyl)(meth)acrylamide, N-(1-piperidinylmethyl)(meth)acrylamide, N-methacryloyl-2-pyrrolidone, N-(methacrylamidomethyl)pyrrolidone, N-(acrylamidomethyl)pyrrolidone, N-(methacrylamidomethyl)caprolactam, N-(acrylamidomethyl)caprolactam, or 2-N-pyridinylethyl(meth)acrylamide, and other heterocyclic compounds, which are listed in EP-A 311,157 and which exhibit a (meth)acrylate or a (methy)acrylamide group; alkoxy (meth)acrylates, such as 2-ethoxyethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, or 2-(ethoxyethoxy)ethyl (meth)acrylate.
Examples of monomers (m4) are: n-propyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-decyl methacrylate, n-dodecyl methacrylate, n-tetradecyl methacrylate, n-hexadecyl methacrylate, n-octadecyl methacrylate, n-eicosyl methacrylate, and preferably n-butyl methacrylate.
Preparation of copolymers P
Copolymers P are formed, in a known manner, from monomers (m1), (m2), (m3), and optionally (m4) by a radical, anionic, or group-transfer polymerization (see in this regard, for example, H. Rauch-Puntigam, Th. Voker, Acryl- und Methacrylverbindungen [Acrylic and methacrylic compounds], Springer, Heidelberg, 1967; Houben-Weyl, 4th Ed., Volume XIV/1, pp. 1010ff., Thieme, Stuttgart, 1961). The polymerization of copolymers P can be carried out in bulk, suspension, emulsion, or solution.
In radical polymerization, peroxide compounds, in particular organic peroxides, such as dibenzoyl peroxide or lauroyl peroxide, azo compounds, such as azodiisobutyronitrile, or redox initiators are preferably used in quantities of 0.01 to 5 wt %, based on the monomer fractions.
The radicals triggering the polymerization can also be produced by high-energy radiation. Molecular weight regulators which can be taken into consideration are, for example, traditional sulfur compounds, such as mercapto compounds in quantities of 0.2 to 8 wt %, based on the monomer fractions. In general, the average molecular weights M w of copolymers P generally lie between 5×10 3 and 5×10 4 daltons, preferably between 10 4 and 3×10 4 daltons.
Copolymers P contain the following: methyl methacrylate units, 30 to 94.5 wt %, preferably 45 to 88 wt %, based on the total monomers; monomer units (m2), 5 to 50 wt %, preferably 10 to 45 wt %; and monomer units (m3), 0.5 to 20 wt %, preferably 2 to 15 wt %. In a particularly preferred specific embodiment of the invention, copolymers P also contain 0.5 to 30 wt %, preferably 1 to 25 wt %, of monomer units (m4), which generally influence the melt flow behavior and the compatibility of copolymers P with the standard plastics to be dyed in a favorable way, and thus improve the compoundability of the pigments and the pigment dispersants P or the mixtures.
With a large number of standard plastics SK, such as polymethyl methacrylate (PMMA), copolymers of methyl methacrylate and optionally substituted styrenes, polystyrene (PS), poly-α-methylstyrene (P-α-MS), styrene-acrylonitrile copolymers (SAN), acrylonitrile-butadiene-styrene terpolymers, polyolefins, such as polyethylene or polypropylene, polycarbonate (PC), polyester carbonate, polyvinyl chloride (PVC), chlorinated rubber, or polyvinylidene fluoride (PVDF), copolymers P form compatible polymer mixtures PM, whose characterization takes place according to recognized criteria (see in this regard, for example, Kirk-Othmer, Encyclopedia of Chemical Technology, Vol. 18, pp. 457-460, Wiley Interscience, New Work, 1981, J. Brandrup, E. H. Immergut, Polymer Handbook, 2nd Ed., Chapter III, pp. 211ff., Wiley Interscience, New York, 1975).
The compatible polymer mixtures PM of amorphous plastics SK and copolymer P has one refractive index and one single glass transition temperature, which lies between the glass transition temperatures of copolymer P and standard plastic SK. As another indication of the compatibility, one can cite the appearance of the LCST (Lower Critical Solution Temperature), whose existence is based on the process that during heating, the transparent mixture, which was clear up to then, is separated into dissimilar phases and becomes optically cloudy, which is clear evidence that the original polymer mixtures consisted of a single phase in thermodynamic equilibrium (see in this regard, for example, D. R. Paul, Polymer Blend & Mixtures, pp. 1ff., Martinus Nijhoff Publishers, Dordrecht, Boston, 1985).
Pigments and dyes
As pigments in the preparations of the invention, containing pigment and copolymer P, both inorganic and organic pigments can be used. Suitable inorganic pigments are, for example: aluminum oxide hydrate, antimony oxide, barium sulfate, bronze powder, cadmium oxide, cadmium sulfide, calcium carbonate, calcium silicate, lead sulfate, lead chromate, lead oxide, lead chromate molybdate, chromium oxides, chromium antimony titanate, cobalt aluminate, iron oxides, graphite, mercury oxide, mercury sulfide, nickel titanate, silicon dioxide, silicon chromate, strontium chromate, magnesium silicate, titanium dioxide, ultramarine blue, zinc oxide, zinc chromate, zinc sulfide, or zirconium dioxide (see in this regard, for example: Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd., Ed., Vol. 17, pp. 788-838, Wiley Interscience, New York, 1982, Ullmanns Encyclopadie der Technischen Chemie [Ullmann's Encyclopedia of Technical Chemistry], 4th Ed., Vol. 18, pp. 545-660, Verlag Chemie, Weinheim, 1979).
Examples of organic pigments are the following: phthalocyanine blue, phthalocyanine green, Malachite Green, Naphthol Red, toluidine red, pyrazolone red, rhodamine, alizarin, Hansa Yellow, anthraquinone, dianisidine orange (see in this regard: Kirk-Othmer, loc. cit., Vol. 17, pp. 838-871; Ullmanns Encyclopadie der Technischen Chemie, 4th Ed., Vol. 18, pp. 661-695, Verlag Chemie, Weinheim, 1979).
The pigments are present in more or less large, occasionally crystal-like agglomerates and are broken up into smaller agglomerates by the pigment dispersants. The dyes are generally dissolved molecularly in the plastic substrate and are to be distinguished from the pigments. However, the solubility of many dyes in standard plastics is poor or the dye intensity of many dyes is too large, so that a direct metering in of the dyes into the plastic melt is not possible. Even in such cases, copolymers P of the invention are excellent as dye dispersants. Examples of such dyes are the following: azo compounds, stilbene compounds, carotinoid dyes, di- and triarylmethane compounds, methine and polymethine compounds or thiazine compounds (see in this regard, Kirk-Othmer, loc. cit., Vol. 8, pp. 159-212, Wiley Interscience, New York, 1979). Such dyes are generally linked by physical interactions, such as hydrogen bonds or dipolar interactions, to copolymer P and/or to the standard plastic SK. The optical properties of such dyes are determined by electron transitions between molecule orbitals, whereas the optical properties of pigments are, moreover, influenced by the structure of the pigment particles. In contrast to the dyes, the pigments retain the primary particle form (crystallites) unchanged during the compounding steps.
Mixtures M of pigments and dyes with copolymers P
Mixtures M of pigments or dyes with copolymer P, in accordance with the invention, are produced by conventional mixing methods, such as melt-mixing or mixing in a solvent.
In general, mixtures MP of pigments and copolymers P contain 0.1 to 95 wt %, preferably 0.2 to 75 wt %, particularly preferably 0.5 to 70 wt %, pigment, with the fraction of copolymer P supplemented to make up 100 wt %. Possible amounts of copolymer P are 99.5-5 wt %, 99.8-25 wt. % and 99.5-30 wt %.
Mixtures MF of dyes and copolymers P contain 0.05 to 50 wt %, preferably 0.1 to 25 wt %, particularly preferably 0.2 to 15 wt %, dye, with the fraction of copolymer P supplemented to make up 100 wt %. Possible amounts of copolymer P are 99.95-50 wt %, 99.9-75 wt % and 99.8-85 wt %. For the production of mixtures MP or MF, the generally powdery pigments or dyes are first premixed with copolymers P typically present in granulated form or as material to be ground in slowly running mixing units, such as drum, gyrowheel or double-chamber plough bar mixers. These slowly running mixing units usually produce a mechanical mixing without elimination of the phase boundaries (see, for example, Ullmanns Encyclopadie der Technische Chemie, 4th Ed., Vol. 2, pp. 282-311, Verlag Chemie, Weinheim, New York, 1980). Premixtures produced in such a manner are thermoplastically prepared with homogeneous mixing of the aforementioned mixture components in the melt, using heatable mixing units at suitable temperatures, for example, 150° to 300° C., in kneaders or preferably in extruders, such as in single- or multiple-screw extruders or perhaps in extruders with an oscillating screw and with shear pins (kneaders from the BUSS COMPANY). With these methods, uniform-grain granulated materials with particle sizes of 2 to 5 mm are produced. The granulated materials contain a thermoplastic fraction, synthesized from copolymer P, and the pigments or dyes embedded therein.
In another specific embodiment of the invention, copolymer P is dissolved in a suitable solvent, and the pigment is dispersed in the resulting solution (or the dye is dissolved in the solution). This can be carried out, for example, with the aid of shaking devices or a ball mill. The solvent can be removed directly after the mixing process, or mixture M of copolymer P and the pigment or dye can be precipitated from the solution with suitable precipitating agents in order to isolate mixtures M. The preparation of mixtures M with the aid of solvents is taken into consideration, in particular for high pigment or dye concentration, generally above 75 wt %. In these high concentrations, the pigment or dye particles are present separately, coated with copolymer P, and copolymer P no longer forms a cohesive phase.
Working of mixtures M into standard plastics SK
Standard plastics SK, into which mixture M of pigments or dyes with copolymer P is worked as a universally acting dispersant, form compatible mixtures with copolymer P. This results in mixtures SKMF of transparent standard plastics SK and mixtures MF (mixtures of copolymer P and dyes) also being transparent.
Mixtures SKMP of standard plastics SK and pigment-dispersant preparations MP generally contain 0.5 to 80 wt %, preferably 1 to 70 wt %, particularly preferably 2 to 50 wt %, mixture MP of copolymer P and pigment, with the fraction of SK supplemented to make up 100 wt %. Amounts of SK generally fall in the range 99.5-20 wt. %, 99-30 or 98-50 wt. %. For the preparation of mixtures SKMP, generally granulated or powdery mixtures MP are first mixed mechanically in slowly running mechanical mixing units, without eliminating the phase boundaries (as described in the preparation of mixtures MP). The preliminary mixtures are generally mixed in the melt, using heatable mixing units at suitable temperatures for example, between 150° and 350° C., in kneaders or preferably in extruders, such as single-screw or multiple-screw extruders. With this method, mixtures SKMP are generally obtained as uniform-grain granulated materials with particle sizes of 2 to 5 mm.
Mixtures SKMF of standard plastic SK and dye-dispersant preparations MF generally contain 0.01 to 40 wt %, preferably 0.05 to 25 wt %, particularly preferably 0.1 to 20 wt %, mixture MF of copolymer P and dye, with the fraction of SK supplemented to make up 100 wt %. Amounts of SK generally fall in the range 99.99-60 wt. %, 99.95-75 wt. %, or 99.9-80 wt %. Generally, mixtures SKMF, such as mixtures SKMP, are preferably prepared by melt-mixing. If the dyes exhibit a high volatility, however, and there is concern-that the migration losses or decomposition of the dye assumes undesired forms, then mixtures SKMF are prepared by dissolving mixture components SK and MF in the common solvent and the subsequent removal of the solvent or precipitation of the mixture.
Advantageous effects of the invention
Due to the universal compatibility of copolymers P of the invention, with standard plastics SK, pigments and dyes can be worked into many standard plastics SK with the same dispersant P. This makes possible the universal applicability of mixtures MP (dispersant P and pigment) and MF (dispersant P and dye) in very different plastics SK, without having to adapt dispersant P to the plastic. Furthermore, a uniform distribution of dyes in transparent standard plastics SK is possible with the aid of dispersants P, without impairing their transparency. In addition dispersants P can be prepared according to standardized polymerization methods, wherein monomer components of copolymers P are readily accessible.
Very different pigments and dyes can be worked into standard plastics SK with dispersants P. With a particular copolymerization composition P, very different mixtures MP and MF can be prepared, which can be worked into standard plastics SK equally well.
EXAMPLES
Having generally described this invention, a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified.
Examples 1-8
Preparation of various universally compatible pigment binders P
For the preparation of 9 or 10 kg polymer P, 5 kg methyl methacrylate, 3.5 kg cyclohexyl methacrylate, 0.5 kg monomer (m3) and optionally 1 kg monomer (m4) are mixed with 4 g tert-butyl perneodecanoate, 15 g tert-butyl peroctoate, and 150 g 2-mercaptoethanol while stirring. The mixture is degassed for 15 min. Subsequently the mixture is poured into a bag made of polyester film, which lies between two halves of an appropriately dimensioned tin container provided with rubber sealing lips, which is then closed. The polymerization takes place in the chamber immersed in a water bath at 50° C. and lasts 20 h. The contents of the bag, which are solid after this polymerization time, are removed from the chamber, and temperature-conditioned at 110° C. in the conditioning cabinet for 12 h for the final polymerization. The resulting polymer P is ground in a mill with a screen size 8 and can be used either as material for grinding or after degassing extrusion at 150° C., as a granulated material.
TABLE 1______________________________________ J values according to DIN 51562Example Monomer (m3) Monomer (m4) (ml/g)______________________________________P 1 2-Dimethylamino- -- 23.3 ethylmethacrylateP 2 2-(4-Morpholine)- -- 26.4 ethylmethacrylateP 3 2-[2-(2-Ethoxy- -- 27.4 ethoxy)ethoxy]- ethylmethacrylateP 4 N-(2-Methacryloyl- -- 25.8 oxyethyl)ethyleneureaP 5 2-Dimethylamino- Butylmeth- 24.0 ethylmethacrylate acrylateP 6 2-(4-Morpholine)- Butylmeth- 25.4 ethylmethacrylate acrylateP 7 2-[2-(2-Ethoxy- Butylmeth- 25.9 ethoxy)ethoxy]- acrylate ethylmethacrylateP 8 N-(2-Methacryloyl- Butylmeth- 26.2 oxyethyl)ethyleneurea acrylate______________________________________
Comparative Examples 9-10
Preparation of pigment binders P' according to the state of the art.
The preparation of polymers takes place according to Examples 1-8:
TABLE 2______________________________________ J value according to DIN 51562Example Composition of the polymer (ml/g)______________________________________ P'9 95 Parts by weight Methylmethacrylate 25.5 5 Parts by weight 2-Dimethylaminoethyl- methacrylateP'10 95 Parts by weight Cyclohexylmethacrylate 25.1 5 Parts by weight 2-Dimethylaminoethyl- methacrylate______________________________________
Examples 11-15
Preparation of mixtures MF of pigment binders P and molecularly dissolved dyes
In addition to 1 kg pigment binder P or P', in accordance with Examples 1-10, 10 g soluble dye THERMOPLASTGELB® 104 from BASF AG are weighed and mixed in a tumbling mixer for 5 min. The dry mixture formed is subsequently extruded and strand-granulated on a single-screw laboratory extruder from the STORCK COMPANY at 180° C.
TABLE 3______________________________________Example 6 Mixture Mixture Components______________________________________11 MF 5 P 5 + THERMOPLASTGELB® 10412 MF 6 P 6 + THERMOPLASTGELB® 10413 MF 7 P 7 + THERMOPLASTGELB® 10414 MF 8 P 8 + THERMOPLASTGELB® 10415 (Comparison) MF '9 P '9 + THERMOPLASTGELB® 10416 (Comparison) MF '10 P '10 + THERMOPLASTGELB® 104______________________________________
Examples 17-22
Preparation of mixtures SKMF of thermoplastic standard plastics SK and mixtures MF in accordance with Examples 11-16
For the preparation of 1 kg of a dyed standard plastic SKMF, 50 g of mixtures MF in accordance with Examples 11-15 are mixed with 950 g standard plastic SK in a tumbling mixer and extruded in a single-screw extruder at a screw rotational speed of 70 rpm. The extrusion temperatures are dependent on the type of standard plastic SK and listed below. The compatibility was evaluated visually on the extruded strand. Compatibility between mixing components SK and MF exists if the extruded strand is transparent (+); incompatibility, if the extruded strand has an opaque appearance (-).
The following standard plastics SK are compounded:
TABLE 4______________________________________ Extrusion TemperatureAbbreviation Origin (°C.)______________________________________PP (Polypropylene) VESTOLEN® 7035 200 from HulsAGPS (Polystyrene) Polystyrene 158 K 220 from BASF AGSAN (Styrene- LURAN® 368 R from 230acrylonitrile) BASF AGPMMA (Polymethyl PLEXIGLAS® Y8N 240methacrylate) from Rohm GmbHPC (Polycarbonate) MAKROLON® 3100 250 from Bayer AGPVC (Polyvinylchloride) VESTOLIT® M 6067, Huls AG 180______________________________________
TABLE 5______________________________________ Compatibility Evaluation (transparent +/nontransparent coating-)Example Mixture PP PS SAN PMMA PC PVC______________________________________17 SKMF5 = SK + MF5 + + + + + +18 SKMF6 = SK + MF6 + + + + + +19 SKMF7 = SK + MF7 + + + + + +20 SKMF8 = SK + MF8 + + + + + +21 SKMF'9 = SK + MF'9 + - + + - +22 SKMF'10 = SK + + + - - - + MF'10______________________________________
Examples 23-31
Investigation of the compatibility of pigment binders P, in accordance with Examples 1 to 9, with Polystyrene 158K from BASF
1 g pigment binder P and 1 g Polystyrene 158 K (PS) are dissolved in 10 g 2-butanone at room temperature. The solution is poured into a Petri dish, and the solvent is completely removed at 70° C. and a vacuum of 20 mbar. The resulting film of the polymer mixture is visually evaluated and is investigated on a Kofler heating bench regarding its demixing temperature LCST (temperature at the transition: clear (thermodynamically compatible mixture)→cloudy (thermodynamically incompatible mixture)).
TABLE 6______________________________________ Film LCSTExample Mixture Evaluation (°C.)______________________________________23 PS + P1 = 50/50 clear 20524 PS + P2 = 50/50 clear 20525 PS + P3 = 50/50 clear 21026 PS + P4 = 50/50 clear 15027 PS + P5 = 50/50 clear >24028 PS + P6 = 50/50 clear 21529 PS + P7 = 50/50 clear 21030 PS + P8 = 50/50 clear 16531 PS + P'9 = 50/50 cloudy <80(Comparison)______________________________________
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | The invention is a copolymer P, dispersant for dyes and/or pigments in standard plastic substances SK, wherein P exhibits a universal compatibility with standard plastics SK, with the feature that copolymer P is synthesized from monomer units:
(m1) methyl methacrylate,
(m2) (meth)acrylate of formula I: ##STR1## (m3) (meth)acryl compound of formula II: ##STR2## and optionally (m4) methacrylate of formula III: ##STR3## | 2 |
BACKGROUND OF THE INVENTION
Photochromic glasses or phototropic glasses, as such have been variously designated, had their genesis in U.S. Pat. No. 3,208,860. Such glasses become darker (change color) when subjected to actinic radiation, customarily ultraviolet radiation, and fade or assume their original color when removed from the actinic radiation. That patent discloses the utility of silver halide crystals, i.e., silver chloride, silver bromide, and/or silver iodide, in causing the phenomenon and postulates an explanation of the mechanism generating photochromic behavior in those glasses containing silver halide crystals. The patent is directed generally to silicate glasses and specifies minimum amounts of silver and halogens which must be present to impart photochromic behavior thereto. Thus, at least one halogen in the indicated minimum effective proportion of 0.2% chlorine, 0.1% bromine, and 0.08% iodine and a minimum of silver in the indicated proportion of 0.2% in a glass wherein the effective halogen is chlorine, 0.05% in a glass containing at least 0.1% bromine, but less than 0.8% iodine, and 0.03% in a glass containing at least 0.08% iodine must be present.
The patent notes the preferred base glass compositions as being included within the R 2 O--Al 2 O 3 --B 2 O 3 --SiO 2 system. Accordingly, the preferred base glass compositions consist essentially, expressed in weight percent on the oxide basis, of about 40-76% SiO 2 , 4-26% B 2 O 3 , 4-26% Al 2 O 3 , and at least one alkali metal oxide (R 2 O) in the indicated proportion of 2-8% Li 2 O, 4-15% Na 2 O, 4-15% K 2 O, 8-25% Rb 2 O, and 10-30% Cs 2 O, the sum of those components plus the silver halides constituting at least 85% by weight of the total composition.
Finally, the patent observes that, where a transparent photochromic glass article is desired, the composition thereof will not contain more than 0.7% silver or more than 0.6% total of the three halides, and the content and size of the silver halide crystals will not exceed 0.1% by volume and 0.1 micron, respectively.
Ophthalmic lenses, both as prescription lenses and as non-prescription sunglasses, have comprised the largest commercial application of photochromic glass. Prescription lenses, marketed by Corning Glass Works, Corning, New York under the trademark PHOTOGRAY, have formed the greatest segment of the ophthalmic sales. The composition of that glass falls within the disclosure of U.S. Pat. No. 3,208,860, supra, an approximate analysis therefor in weight percent being:
______________________________________ SiO.sub.2 55.6 B.sub.2 O.sub.3 16.4 Al.sub.2 O.sub.3 8.9 Li.sub.2 O 2.65 Na.sub.2 O 1.85 K.sub.2 O 0.01 BaO 6.7 CaO 0.2 PbO 5.0 ZrO.sub.2 2.2 Ag 0.16 Cu 0.035 Cl 0.24 Br 0.145 F 0.19______________________________________
Because PHOTOGRAY brand glass was developed through compromises with respect to such factors as photochromic behavior, ophthalmic properties, the capability for being chemically strengthened, and melting and forming characteristics, research has been ongoing to produce glasses having improved photochromic properties while still retaining the other qualitites necessary for a practical commercial glass.
U.S. application Ser. No. 14,981, filed Feb. 28, 1979 in the names of G. B. Hares, D. L. Morse, T. P. Seward, III, and D. W. Smith, now U.S. Pat. No. 4,190,451 discloses glasses demonstrating improved photochromic behavior when compared with PHOTOGRAY brand glass, i.e., such glasses darken to a lower transmission when exposed to actinic radiation and fade more rapidly when the actinic radiation is removed. That application describes glasses having compositions consisting essentially, in weight percent on the oxide basis, of:
______________________________________SiO.sub.2 20-65B.sub.2 O.sub.3 14-23Al.sub.2 O.sub.3 5-25P.sub.2 O.sub.5 0-25Li.sub.2 O 0-2.5Na.sub.2 O 0-9K.sub.2 O 0-17Cs.sub.2 O 0-6Li.sub.2 O + Na.sub.2 O + K.sub.2 O + Cs.sub.2 O 8-20CuO 0.004-0.02Ag 0.15-0.3Cl 0.1-0.25Br 0.1-0.2______________________________________
wherein the molar ratio alkali metal oxide:B 2 O 3 ranges between about 0.55-0.85 in those compositions which are essentially free from divalent metal oxides other than CuO, and the weight ratio Ag:(Cl+Br) ranges between about 0.65-0.95.
Recently, a new photochromic glass for ophthalmic applications having a composition encompassed within that disclosure was entered into the marketplace by Corning Glass Works, Corning, N.Y. under the trademark PHOTOGRAY EXTRA and cataloged as Code 8111 glass. That glass has the following approximate analysis, in weight percent, of:
______________________________________ SiO.sub.2 55.8 Al.sub.2 O.sub.3 6.48 B.sub.2 O.sub.3 18.0 Li.sub.2 O 1.88 Na.sub.2 O 4.04 K.sub.2 O 5.76 ZrO.sub.2 4.89 TiO.sub.2 2.17 CuO 0.011 Ag 0.24 Cl 0.20 Br 0.13______________________________________
In order to better control growth of the silver halide crystals with consequent better uniformity and reproducibility of photochromic behavior, the proper glass-forming batches are melted, the melt cooled sufficiently rapidly to yield a glass shape, and this glass shape thereafter subjected to a heat treatment to nucleate and grow the silver halide crystals. The PHOTOGRAY and PHOTOGRAY EXTRA brand glasses darken to a neutral or gray color when exposed to actinic radiation. However, in light of interest in the marketplace for a photochromic ophthalmic lens which would darken to a brown hue, lens blanks were produced and sold by Corning Glass Works under the trademark PHOTOBROWN. Those lens blanks were prepared via a particular heat treatment being applied to glass compositions within narrowly-defined ranges. A description of their preparation is set forth in U.S. Pat. No. 4,043,781. Thus, glasses consisting essentially, in weight percent on the oxide basis, of
______________________________________ SiO.sub.2 53-60 Al.sub.2 O.sub.3 8-10 B.sub.2 O.sub.3 15-18 Na.sub.2 O 1-3 Li.sub.2 O 1.5-3.2 BaO 5-9 PbO 3.5-7 ZrO.sub.2 0-4 CuO 0.012-0.040 Ag 0.14-0.22 Cl 0.22-0.36 Br 0.10-0.20 F 0-1______________________________________
are subjected first to a temperature within the range of 520°-580° C. for about 2-30 minutes and thereafter exposed to a temperature within the range of 600°-660° C. for about 5-60 minutes.
As can readily be observed, the utility of the method is limited to a narrow range of glass compositions and, hence, the breadth of photochromic behavior which can be enjoyed is likewise narrowly limited. For example, the composition of PHOTOGRAY EXTRA brand glass falls outside the purview of that disclosure and, indeed, the patented heat treatment disclosed in U.S. Pat. No. 4,043,781 does not lead to the development of a brownish tint in that glass in the darkened state. Modifications in the disclosed heat treatments can induce a slight brownish cast in that glass in the darkened state but only at the expense of obtaining less desirable photochromic properties.
Of course, the addition of colorants to glass compositions to produce various colorations therein is well known to the art. Hence, for example, a combination of cobalt, nickel, and manganese has been utilized to achieve a brown coloration in glass (U.S. Pat. No. 4,116,704). Also, U.S. Pat. No. 4,018,965 discloses the addition of colorants such as the rare earth metal oxides Er 2 O 3 , Pr 2 O 3 , Ho 2 O 3 , and Nd 2 O 3 and/or the transition metal oxides CoO, NiO, and Cr 2 O 3 to develop various tints in photochromic glass compositions. Thus, that patent discloses the use of up to 1% total of those transition metal oxides selected in the indicated proportions of 0-0.5% CoO, 0-1% NiO, and 0-1% Cr 2 O 3 , and/or up to 5% total of those rare earth metal oxides. However, it is apparent that such colorants yield a glass having a permanent tint therein rather than an essentially uncolored glass in the faded state.
OBJECTIVE OF THE INVENTION
The primary objective of the instant invention is to provide a transparent, essentially colorless, photochromic glass which, when exposed to actinic radiation, will darken to a brownish hue but, when removed from the actinic radiation, will return to an essentially colorless appearance.
SUMMARY OF THE INVENTION
That objective can be achieved through the addition of little more than trace amounts of palladium and/or gold to the batch for a photochromic glass wherein crystals of silver chloride, silver bromide, and/or silver iodide impart the photochromic behavior to the glass. Those additions have essentially no effect upon the original appearance of the glass but cause the hue of the darkened color to shift towards the brown with little or no change in the transmittance of the darkened state.
The mechanism operating to generate this shift in color is not fully understood but, because the color is produced with extremely low levels of palladium and/or gold, it has been theorized that the color is due to palladium and/or gold being contained within or deposited upon the surface of the silver halide crystals. Thus, it is postulated that the silver halide crystals have palladium and/or gold particles on the surface thereof or, alternatively, dispersed within the structure thereof.
Inasmuch as the operable concentrations of palladium and/or gold are very minute, i.e., as little as one part per million (ppm), the initial luminous transmittance and freedom from color demonstrated by the glass are substantially unaffected. When more than about 10 ppm are included, however, the initial transmittance and color are obviously affected. Additions of about two to four ppm are deemed to be optimum with about three ppm being considered the most preferred. As a matter of fact, the darkened brownish hue, as defined by chromaticity coordinates, appears to reach a peak in the vicinity of about three to four ppm.
The presence of palladium and/or gold enables the production of the desired brown coloration in the darkened state without the necessity of utilizing a special heat treatment of the glass, such as is described in U.S. Pat. No. 4,043,781, supra. And, as has been explained above, glass composition is not critical except for the presence of silver halide crystals. However, because of the inherent photochromic properties developed therein, the glass compositions of Ser. No. 14,981, supra, are preferred.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Table I illustrates the effect of palladium additions upon the luminous transmittance and darkened chromaticity of Code 8111 glass. The palladium was added in the form of an aqueous solution of PdCl 2 to the batch to yield the recited contents in ppm. The batch was melted in a commercial continuous tank customarily utilized for melting Code 8111 glass. The melt was pressed into standard lens blanks which were then subjected to the heat treatment schedule conventionally employed in a lehr with Code 8111 glass to generate photochromic behavior therein. This heat treatment involves heating the glass to about 650° C. for approximately one-half hour and then cooling at a rate which will yield a satisfactory state of anneal.
Color and photochromic properties were determined utilizing a conventional tristimulus colorimeter and laboratory exposure/photometer system. Each lens blank was ground and polished to yield a thickness of 2 mm. Those specimens were exposed to a source of ultraviolet radiation for 5 minutes at room temperature (˜20°-25° C.) and then removed from the radiation for five minutes. Table I reports the luminous transmittances exhibited by each sample before darkening (T 0 ), after darkening for five minutes (T D5 ), after fading for five minutes (T F5 ), and the amount of fading from the darkened state demonstrated after five minutes, removal from the radiation (T F5 -T D5 ), this latter value being termed "5 minute fade" in the art. Table I also records the chromaticity coordinates (x,y) of the darkened specimens utilizing Illuminant C.
TABLE I______________________________________Pd ppm T.sub.o T.sub.D5 T.sub.F5 T.sub.F5-D5 x y______________________________________0 91 34 71 37 0.3140 0.31601 89.5 35 72 37 0.3350 0.32752 88.5 36 73 37 0.3460 0.33603 87 37 73 36 0.3475 0.33705 86.5 38 74 36 0.3340 0.3340______________________________________
As can be observed from Table I, palladium additions at about the 3 ppm level are preferred because: (1) the darkened color has a slight red cast, hence a warm brown, rather than a yellow element therein; and (2) the undarkened transmittance of the glass is not substantially affected thereby. It is interesting to note, via a study of the chromaticity coordinates, that the color passes through a peak at about 3 ppm Pd with larger additions causing a return towards neutral gray brought about via an addition of a blue component. Moreoever, further additions tend to have a substantive effect upon the undarkened transmittance of the glass. Accordingly, levels of about 2-4 ppm are preferred. The preferred color has coordinates at approximately x=0.3228 and y=0.3187 and is deemed to exhibit a more pleasing hue than the color produced via the disclosure of U.S. Pat. No. 4,043,781, supra.
Metallic gold appears to behave in a manner similar to that displayed by palladium. Table II sets forth several glass compositions, expressed in parts by weight on the oxide basis as calculated from the batch, designed to illustrate this phenomenon. Inasmuch as it is not known with what cation(s) the halides are combined, they are merely reported as the halide, i.e., chloride and bromide, in accordance with conventional glass analysis practice. The silver content of photochromic glass has most generally been recited as the metal Ag, and that practice is adhered to here. Since the sum of the individual constituents of each composition closely approximates 100, for all practical purposes the quantities tabulated may be considered to indicate weight percent.
The actual batch ingredients of the base glass compositions can comprise any materials, either the oxide or other compound, which, when melted in conjunction with the other components, will be converted into the desired oxide in the proper proportions. Out of convenience, the halides were commonly added as alkali metal halides, the silver component was normally included as AgNO 3 or Ag 2 O, and the gold was added as a 2% by weight color batch of gold chloride in sand.
The batch ingredients were compounded to prepare about 1000 g of each composition, the batches tumblemilled thoroughly to aid in securing a homogeneous melt, and then deposited into platinum crucibles. The crucibles were covered with silica lids, placed into a laboratory furnace operating at about 1450° C., and maintained therein for about three hours. The melts were then stirred with a platinum-rhodium stirrer. The bulk of each melt was poured into a steel mold to yield a glass slab having the dimensions of about 10"×4"×1/2" with the remainder being poured onto a steel plate as a small, free-flowing glass patty. The large slabs were immediately transferred to an annealer operating at 375° C. and held therewithin for two hours. The small patties were simply allowed to cool to room temperature in the ambient environment.
TABLE II______________________________________1 2 3 4______________________________________SiO.sub.2 62.6 62.6 62.6 62.6B.sub.2 O.sub.3 16.9 16.9 16.9 16.9Al.sub.2 O.sub.3 9.5 9.5 9.5 9.5Na.sub.2 O 3.8 3.8 3.8 3.8Li.sub.2 O 1.8 1.8 1.8 1.8K.sub.2 O 4.9 4.9 4.9 4.9Ag 0.25 0.25 0.25 0.25CuO 0.012 0.012 0.012 0.012Cl 0.15 0.15 0.15 0.15Br 0.16 0.16 0.16 0.16Au -- 0.0005 0.001 0.0015______________________________________
Color and photochromic properties determined on 2 mm thick ground and polished samples taken from the small, unannealed patties which had been heated at 660° C. for 30 minutes and then allowed to cool to room temperature in the ambient atmosphere are listed in Table III. The measurements were performed employing a solar simulator apparatus similar to that described in U.S. Pat. No. 4,125,775. The darkened luminous transmittance for eight spectral wavelengths (400 nm, 440 nm, 480 nm, 530 nm, 580 nm, 640 nm, 685 nm, and 735 nm) was measured simultaneously utilizing eight suitably filtered P/N silicon photodiodes. The apparatus was interfaced to a PDP-11/04 computer (marketed by Digital Equipment Corporation, Maynard, Mass.) and the chromaticity values calculated by a modification of the weighted ordinate method (A. C. Hardy, Handbook of Colorimetry, Technology Press, page 33, 1936).
In like manner to Table I, T 0 represents the luminous transmittance of each sample before darkening, T D5 indicates the transmittance after a five-minute exposure to the solar simulator, T F5 designates the transmittance after a removal of five minutes from the solar simulator, T F5 -T D5 the amount of fading undergone after five minutes, and x and y are the chromaticity coordinates of the darkened samples utilizing Illuminant C.
TABLE III______________________________________Example No. T.sub.o T.sub.D5 T.sub.F5 T.sub.F5-D5 x y______________________________________1 90.6 43.1 72.3 29.8 0.3276 0.32352 86.5 37.7 67.1 29.4 0.3668 0.34063 81.6 35.0 64.9 29.9 0.3670 0.33934 70.1 30.6 58.0 28.4 0.3715 0.3339______________________________________
Table III clearly illustrates the capability of gold to cause the production of a brown coloration in the darkened state of photochromic glasses. Examples 3 and 4 unequivocally demonstrate the effect upon the undarkened transmittance of the glass which additions of gold of 10 ppm and greater can exert. Furthermore, such greater additions yield a deeper brown coloration in the darkened state of the glass. Again, the warmest brown colorations appear to be observed with gold additions in the 2-4 ppm range.
As manifested in Table III, Example 4, containing 15 ppm gold, exhibited an undarkened transmittance of only about 70%. However, the use of lower heat treatment temperatures to develop photochromic properties can result in glasses with higher undarkened transmittances. Table IV illustrates this phenomenon through a comparison of samples cut from the annealed slabs of Examples 1 and 4 which were subsequently subjected to three different heat treatments. The measurements recited in Table IV were made in like manner to those reported in Table III. Also, the legends appearing in Table IV have the same meaning as in Table III.
TABLE IV______________________________________Heat Treatment 610° C. for 30 MinutesExample No. T.sub.o T.sub.D5 T.sub.F5 T.sub.F5-D5 x y______________________________________1 91.4 74.1 85.6 11 0.3198 0.32264 85.4 55.0 74.2 19.2 0.3476 0.3387______________________________________Heat Treatment 630° C. for 30 minutesExample No. T.sub.o T.sub.D5 T.sub.F5 T.sub.F5-D5 x y______________________________________1 90.9 57.5 75.2 17.7 0.3243 0.32244 77.9 40.3 64.6 24.6 0.3524 0.3330______________________________________Heat Treatment 660° C. for 30 MinutesExample No. T.sub.o T.sub.D5 T.sub.F5 T.sub.F5-D5 x y______________________________________1 89.5 34.8 64.8 30 0.3382 0.32854 66.3 26.4 52.7 26.3 0.3721 0.3287______________________________________
Accordingly, because of these differences in color which can be achieved in the undarkened state in glasses containing relatively high levels of gold and/or palladium, e.g., about 10 ppm, it is quite possible, through differential heat treatment thereof, to make such glasses to exhibit a gradient optical density brownish tint in the undarkened state and also demonstrate a gradient photochromic darkening behavior to a deeper brownish coloration. One method for achieving such differential heat treatment involves the use of a heat sink such as is described in U.S. Pat. No. 4,072,490. The example cited below is illustrative of that practice.
A glass having the following composition, the base components being calculated in terms of parts by weight on the oxide basis from the batch ingredients and the "photochromic elements", i.e., the Cl, Br, CuO, and Ag, being analyzed via X-ray fluorescence, was melted and blanks for ophthalmic lenses pressed therefrom. The gold was again incorporated into the melt as a 2% by weight color batch of gold chloride in sand.
______________________________________ SiO.sub.2 56.6 Al.sub.2 O.sub.3 6.3 B.sub.2 O.sub.3 18.2 Na.sub.2 O 4.1 Li.sub.2 O 1.8 K.sub.2 O 5.7 ZrO.sub.2 5.0 TiO.sub.2 2.3 Au 0.002 Cl 0.163 Br 0.133 CuO 0.013 Ag 0.224______________________________________
After annealing the blanks in a lehr operating at 500° C., 3 mm, 6 diopter lenses were ground and polished therefrom. Those lenses were then placed onto heat sink ceramic formers and the formers placed in a lehr which was scheduled such that the lenses were exposed to a peak temperature zone of about 670° C. for about 15 minutes. This treatment yielded lenses manifesting a distinct golden brown tint in that portion of the lens which had been exposed to the 670° C. heat treatment with the other portion of the lens being essentially colorless.
Color and photochromic properties were determined on each portion of the lenses utilizing the apparatus described above in connection with the measurements reported in Table III, the thickness of the lenses being 3 mm instead of 2 mm. Table V records the results of those determinations, the legends appearing therein having the same definitions as those of Table III except that D10 refers to darkening under ultraviolet radiation for 10 minutes.
TABLE V______________________________________Sample T.sub.o x.sub.o y.sub.o T.sub.D10 x.sub.D10 y.sub.D10______________________________________Dark 78.6 0.3279 0.3383 53.1 0.3667 0.3582PortionLight 87.4 0.3160 0.3286 81.1 0.3278 0.3394Portion______________________________________
Another technique for achieving a gradient heat treatment comprises placing the lens onto a ceramic former and burying about one-half of that combination in a suitably upright position in sand, alumina, or other suitable refractory material in particulate form. The assembly can then be placed in a furnace and subjected to a predetermined heat treatment.
Lenses of 2 mm thickness were ground and polished from a glass having the above composition but wherein 16 ppm palladium (0.0016%) were substituted for the gold. The lenses were placed upon ceramic formers and about one-half of the combination was buried in finely-divided alumina particles. Color and photochromic characteristics of the two portions of the lenses were determined after exposure of the assembly to 640° C. for 10 minutes. The measuring apparatus was again the same as that described above. Table VI reports the results of those determinations, the legends therein reflecting the same meaning as those set forth in Table V.
TABLE VI______________________________________Sample T.sub.o x.sub.o y.sub.o T.sub.D10 x.sub.D10 y.sub.D10______________________________________Dark Half 81.3 0.3210 0.3324 42.2 0.3412 0.3416Light 89.5 0.3124 0.3225 85.6 0.3151 0.3251Half______________________________________
That the use of colorants to permanently tint photochromic glasses is well known to the art has been observed above. The present invention permits those tints to be complemented through the addition of a warm brown darkened hue thereto. For example, a warm brown hue in the darkened state can be imposed upon the permanent pink tint imparted to a glass through the inclusion of Er 2 O 3 in the composition thereof.
As has been explained above, the inclusion of gold and/or palladium in amounts exceeding about 10 ppm substantively effects the initial color and transmittance of the glasses. Nevertheless, where this phenomenon is not undesirable, even larger quantities of those metals can be included, e.g., up to 50 ppm. Such additions, however, may exceed their solubility in the glass compositions, thereby giving rise to the development of haze in the glass bodies due to the presence of particles therein.
Additions of platinum and/or rhodium and/or iridium to the glass compositions appear to generate a similar phenomenon in silver halide-containing photochromic glasses of a brownish tint in the darkened state. However, the effectiveness of such additions is far less than that demonstrated by palladium and/or gold, therefore requiring much greater additions. Accordingly, the use of palladium and/or gold is much more economically attractive. | The present invention is primarily directed to transparent photochromic glasses which are essentially colorless in the undarkened state but which exhibit a warm brown coloration in the darkened state. Such glasses utilize silver halide crystals to impart photochromic behavior thereto and contain about 1-10 ppm palladium and/or gold. The instant invention is secondarily directed to silver halide crystal-containing photochromic glasses having in excess of 10 ppm palladium and/or gold which exhibit a brownish tint in the undarkened state and a deeper brown coloration in the darkened state. Through differential heat treatment thereof, the latter glasses can be made to exhibit a gradient optical density brownish tint in the undarkened state and also demonstrate a gradient photochromic darkening behavior to a deeper brownish coloration. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims benefit of priority to U.S. Provisional Patent Application No. 61/838,441 filed Jun. 24, 2013 which is incorporated herein by reference in its entirety.
BACKGROUND
Field of the Invention
The present invention relates to a method and apparatus for processing geospatial data within a temporal context.
Related Art
As data volumes grow massive, measured in zettabytes or more, the capability for systems to dynamically discover, characterize, and sustain knowledge drawn from data is becoming an imperative for global commerce, businesses, and government entities.
SUMMARY
According to a first broad aspect, the present invention provides a method comprising the following steps: (a) constructing a boundary comprising a set of contextual square quadrangles, and (b) displaying to a user the boundary on a visual display device and/or saving the boundary to a storage medium, wherein each contextual square quadrangle of the set of contextual square quadrangles has a contextual geohash code ID, wherein each contextual geohash code ID has a length, and wherein each contextual square quadrangle of the set of contextual square quadrangles has a precision value based on the length of a contextual geohash code ID for the contextual square quadrangle.
According to a second broad aspect, the present invention provides an apparatus comprising: one or more processors, and a machine-readable medium for storing instructions thereon which when executed by the one or more processors cause the one or more processors to perform operations comprising the following steps: (a) constructing a boundary comprising a set of contextual square quadrangles, and (b) displaying to a user the boundary on a visual display device and/or saving the boundary to a storage medium, wherein each contextual square quadrangle of the set of contextual square quadrangles has a contextual geohash code ID, wherein each contextual geohash code ID has a length, and wherein each contextual square quadrangle of the set of contextual square quadrangles has a precision value based on the length of a contextual geohash code ID for the contextual square quadrangle.
According to a third broad aspect, the present invention provides a method comprising the following steps: (a) searching a set of contextual square quadrangles for one or more desired contextual square quadrangles meeting a set of search criteria, and (b) displaying to a user at least one desired contextual square quadrangles of the one or more desired contextual square quadrangles on a visual display device and/or saving the at least one desired contextual square quadrangles to a storage medium, wherein each contextual square quadrangle of the set of contextual square quadrangles has a contextual geohash code ID, wherein each contextual geohash code ID has a length, and wherein each contextual square quadrangle of the set of contextual square quadrangles has a precision value based on the length of a contextual geohash code ID for the contextual square quadrangle.
According to a fourth broad aspect, the present invention provides an apparatus comprising: one or more processors, and a machine-readable medium for storing instructions thereon which when executed by the one or more processors cause the one or more processors to perform operations comprising the following steps: (a) searching a set of contextual square quadrangles for one or more desired contextual square quadrangles meeting a set of search criteria, and (b) displaying to a user at least one desired contextual square quadrangle of the one or more desired contextual square quadrangles on a visual display device and/or saving the at least one desired contextual square quadrangles to a storage medium, wherein each contextual square quadrangle of the set of contextual square quadrangles has a contextual geohash code ID, where each contextual geohash code ID has a length, and wherein each contextual square quadrangle of the set of contextual square quadrangles has a precision value based on the length of a contextual geohash code ID for the contextual square quadrangle.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate exemplary embodiments of the invention, and, together with the general description given above and the detailed description given below, serve to explain the features of the invention.
FIG. 1 shows a table illustrating temporal interval comparisons for examples of the temporal conflation rules included within one embodiment of the contextual geohashing method of the present invention.
FIG. 2 shows diagram illustrating a contextual square quadrangle extruded from a graticule.
FIG. 3 shows three diagrams illustrating level 0 contextual geohash codes, level 1 contextual geohash codes, and level 2 contextual geohash codes according to one embodiment of the present invention.
FIG. 4 shows a table of contextual geohash code IDs at 10 meter precision for (0° N, 0° E).
FIG. 5 shows contextual geohash code compression examples according to one embodiment of the present invention.
FIG. 6 is a diagram showing 64-bit endian examples.
FIG. 7 is a diagram showing a contextual geohash tag header.
FIG. 8 is a diagram showing an example of a contextual geohash code to level 110 according to one embodiment of the present invention.
FIG. 9 is a diagram showing contextual geohash code set compression examples.
FIG. 10 is a diagram show a fuzzy feature example according to one embodiment of the present invention.
FIG. 11 shows a contextual temporal tag time span range.
FIGS. 12 and 12-1 shows a table illustrating contextual geohash code IDs at 5 meter precision for the city of Chantilly, Va. according to one embodiment of the present invention.
FIG. 13 is a diagram showing an example of a contextual elevation geohash tag according to one embodiment of the present invention.
FIG. 14 is a screenshot showing a global view that includes contextual square quadrangles, where differing contexts are illustrated using different colors (shown as different dash-bordered quadrangles in FIG. 14 ) and transparency values, according to one embodiment of the present invention.
FIG. 15 is a screenshot showing a medium scale view that includes contextual square quadrangles, where differing contexts are illustrated using different colors (shown as different dash-bordered quadrangles in FIG. 15 ) and transparency values, according to one embodiment of the present invention.
FIG. 16 is a screenshot showing a regional scale view that includes contextual square quadrangles, where differing contexts are illustrated using different colors (shown as different dash-bordered quadrangles in FIG. 16 ) and transparency values, according to one embodiment of the present invention.
FIG. 17 is a screenshot showing a city scale view that includes contextual square quadrangles, where differing contexts are illustrated using different colors (shown as different dash-bordered quadrangles in FIG. 17 ) and transparency values, according to one embodiment of the present invention.
FIG. 18 is a screenshot showing a 5 m conflation scale view of contextual square quadrangles, where differing contexts are illustrated using different colors (shown as different dash-bordered quadrangles in FIG. 18 ) and transparency values, according to one embodiment of the present invention.
FIG. 19 is a screenshot showing a 0.6 m conflation scale view of contextual square quadrangles, where differing contexts are illustrated using different colors (shown as different dash-bordered quadrangles in FIG. 19 ) and transparency values, according to one embodiment of the present invention.
FIG. 20 is a screenshot showing a 5 mm conflation scale view of a contextual square quadrangle.
FIG. 21 is an illustration of a point geohash set with confidence sets indicated by different shades.
FIG. 22 is an illustration of a line segment geohash set with confidence sets indicated by different shades.
FIG. 23 is an illustration of a complex geohash set with confidence sets indicated by different shades.
FIG. 24 is an illustration of a state boundary and the state boundary as a geohash set with confidence sets indicated by different shades.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Definitions
Where the definition of terms departs from the commonly used meaning of the term, applicant intends to utilize the definitions provided below, unless specifically indicated.
For purposes of the present invention, directional terms such as “top,” “bottom,” “upper,” “lower,” “above,” “below,” “left,” “right,” “horizontal,” “vertical,” “upward,” “downward,” etc., are merely used for convenience in describing the various embodiments of the present invention.
For purposes of the present invention, a value or property is “based” on a particular value, property, the satisfaction of a condition or other factor if that value is derived by performing a mathematical calculation or logical operation using that value, property or other factor.
For purposes of the present invention, the term “Big Data” refers to high volume, high velocity, and/or high variety information assets. Big Data requires non-traditional forms of processing to enable enhanced decision making, insight discovery, and process optimization. In general, Big Data represents a collection of data so large and complex (encompassing all types) that it becomes difficult to process using traditional data processing applications and/or database management systems.
For purposes of the present invention, the term “boundary” refers to any type of boundary between two areas of interest. For example: a boundary may be a terrain feature such as a river, mountain ridge, lake, etc.; a political boundary such as a boundary between two countries, two states within a country, two provinces within a country, between a city and one or more surrounding counties, two or more polling districts, etc.; a boundary between pieces of real estate; a boundary between a metropolitan area and the suburbs for the metropolitan area, etc.
For purposes of the present invention, the term “Catalog Service for the Web ebRIM (CSW-ebRIM)” refers to an OGC standard for exposing a catalog of geospatial records on the Internet via HTTP, which is built upon an OASIS standard called ebRIM (eBusiness Registry Information Model). CSW is analogous to a card catalog in a library and defines common interfaces to discover, browse, and query metadata about data, services, and other resources. CSW is comprised of multiple profiles, including ebRIM, which is extensible and contains both a Registry and a Repository, with the Registry objects referencing and pointing to the associated Repository items. Each repository item (e.g. an HTML document) has a Uniform Resource Name (URN), which is a Uniform Resource Identifier (URI) that uses the URN scheme. The URN allows the repository item to be readily retrieved from the Registry using a simple GET request (e.g. issued from a web client such as a browser).
For purposes of the present invention, the term “celestial hashing” refers to linking sources with a common view of the same location on the celestial sphere at the same time as entities move into and out of that view.
For the purposes of the present invention, the term “celestial sphere” refers to an imaginary sphere of arbitrarily large radius, concentric with a particular celestial body, such as the earth. Unless specified otherwise, the term “celestial sphere” refers to the celestial sphere of the earth.
For purposes of the present invention, the term “computer” refers to any type of computer or other device that implements software including an individual computer such as a personal computer, laptop computer, tablet computer, mainframe computer, mini-computer, etc. A computer also refers to electronic devices such as an electronic scientific instrument such as a spectrometer, a smartphone, an eBook reader, a cell phone, a television, a handheld electronic game console, a videogame console, a compressed audio or video player such as an MP3 player, a Blu-ray player, a DVD player, etc. In addition, the term “computer” refers to any type of network of computers, such as a network of computers in a business, a computer bank, the Cloud, the Internet, etc. Various processes of the present invention may be carried out using a computer. Various functions and methods of the present invention may be performed by one or more computers.
For purposes of the present invention, the term “computer system” refers to a system of interconnected computers.
For purposes of the present invention, the term “confidence set” refers to a set of contextual square quadrangles each having a confidence value at or above a threshold confidence value or each having a confidence value within a particular range of confidence values. For example, a set of contextual square quadrangles each having a confidence value of at least 95% would constitute a confidence set and may be referred to as a 95% confidence set. A set of contextual square quadrangles each having a confidence value between 70% and 80% could also constitute a confidence set and may be referred to as a 70%-80% confidence set. A 100% confidence set, i.e., set in which all of the contextual square quadrangles have a confidence value of 100% may be referred to as a particular geospatial feature such as a point, a line segment, a boundary, a geographic region, etc. This means that the example geospatial feature occurs at the place or location designated by the geohash set with 100% confidence. Features or locations are deemed “fuzzy” when associated with confidence values of less than 100% and locations with a collection of confidence sets represents differing degrees of fuzziness or geospatial ambiguity.
For purposes of the present invention, the term “confidence value” refers to a mathematical, statistical, or logical means for describing the context or an aspect of the aggregate context of a situation described at a place and time.
For purposes of the present invention, the term “conterminous” refers to having a common boundary or enclosed within one common boundary. It is related to the term coterminous. Conterminous is used to describe spatial relationships between various feature sets, including describing a spatial granule or spatial pattern.
For purposes of the present invention, the term “context” refers to the description of properties, attributes, or the descriptive state of an object or entity. By capturing the state of an object, that same state may be applied to the same object at some point in the future to return the object to the source state or context. This is critical for forensic analysis, workflow automation, and pattern matching and pattern recognition.
For purposes of the present invention, the term “contextual geohashing” refers to a method for uniquely delineating a place described on the Earth's surface, extending below the Earth's surface, and extending above the Earth's surface to potentially intersect with the celestial sphere. This place description includes context which may describe the likelihood that some aspects of the place description are more likely to occur than others providing the mechanism to describe some places as “fuzzy” or including spatial ambiguity. Although for simplicity in the description below contextual geohashing is generally only described with respect to the earth, contextual geohashing may be used on celestial bodies such as planets, asteroids, etc.
For purposes of the present invention, the term “contextual geohash code” refers to an ASCII string of variable length, where the length of the ASCII string is proportional to the depth of the modified quadtree comprised of square quadrangles used to describe that square quadrangle. For a contextual geohash code, level −1 (minus one) identifies the place as the entire Earth. For a contextual geohash code, level 0 of the contextual geohash code identifies the hemisphere in which the square quadrangle is located with an ASCII character such as 0 for the western hemisphere and 1 for the eastern hemisphere. Starting with level 1 of a contextual geohash code, the prior region (for example, the hemisphere of level 0) is subdivided into four square quadrangles following a Z-ordered pattern of the same four ASCII characters, such as A, B, C and D, in which the first ASCII character (A in this example) is the northwest component, the second ASCII character (B in this example) is the northeast component, the third ASCII character (C in this example) is the southwest component and the fourth ASCII character (D in this example) is the southeast component. Following this scheme, any contextual square quadrangle can be subdivided into four square quadrangles to define a new level. There are four exception cases used with contextual geohash codes to describe the poles, to describe the whole Earth, and to describe an unspecified location: (a) a single ASCII character such as “&” indicates the North Pole, (b) a single ASCII character such as “=” indicates the South Pole, (3) a single ASCII character such as “#” indicates the whole Earth, including both poles, and (4) a single ASCII character such as“?” indicates an unspecified location, which is used in conjunction with other types of hash codes, such as temporal hash codes.
For purposes of the present invention, the term “contextual geohash code ID refers to the contextual geohash code of specific contextual square quadrangle.
For purposes of the present invention, the term “contextual geohash point” refers to the geospatial point in latitude and longitude of the lower-left or southwest corner of a square quadrangle. This point combined with the precision level of the geohash code delineates the area or region of coverage for that geohash code. Contextual geohash points do not have a one-to-one relationship with geohash code IDs due to the change in scale associated with geohash codes with different levels.
For purpose of the present invention, the term “contextual geohash tag” refers to a type of contextual geohash code IDs, where ASCII character notion is one type of tag and various binary notations describe other equivalent tag types.
For purposes of the present invention, the term “contextual square quadrangle” refers to a square quadrangle having a contextual geohash code ID. A square quadrangle is defined using spherical angles. A contextual square quadrangle deterministically represents a distinct place on the Earth extending from the Earth's center out to the celestial sphere.
For purposes of the present invention, the term “contiguous” refers to a set of things in which each member of the set is in contact with another member of the set. For example, in one embodiment of the present invention a region of coverage may comprise a set of contextual quadrangles in which each geospatial quadrangle is in contact with another contextual square quadrangle of the set. However, non-contiguous or disjointed sets of quadrangles can also be used to describe places, such as Alaska and Hawaii included with the set of contiguous state boundaries.
For purposes of the present invention, the term “continuous time” refers to an unbroken span of time comprised of time instants. In the time domain, the value of a signal or function is known for all real numbers. Within a time granule, a time instant is described as a singular point in time with an associated precision. On a different system implementation capable of supporting greater descriptive precision, the lower precision time instant would convert into a time period with an interval defined at the limits of the describing precision.
For purposes of the present invention, the term “coordinate reference system (CRS)” refers to a coordinate system that is related to the real world by a datum. For geodetic and vertical data, the coordinate reference system is related to the Earth.
For purposes of the present invention, the term “coordinate system” refers to a set of mathematical rules for specifying how coordinates are to be assigned to points.
For purposes of the present invention, the term “coordinate” refers to one of a sequence of n numbers designating the position of a point in n-dimensional space. In a coordinate reference system, the numbers must be qualified by units.
For purposes of the present invention, the term “coordinate system” is set of mathematical rules for specifying how coordinates are to be assigned to points.
For purposes of the present invention, the term “data” means the reinterpretable representation of information in a formalized manner suitable for communication, interpretation, or processing. Although one type of common type data is a computer file, data may also be streaming data, a web service, etc. The term “data” is used to refer to one or more pieces of data.
For purposes of the present invention, the term “database” refers to a structured collection of records or data that is stored in a computer system. The structure is achieved by organizing the data according to a database model. The model in most common use today is the relational model. Other models such as the hierarchical model and the network model use a more explicit representation of relationships (see below for explanation of the various database models). A computer database relies upon software to organize the storage of data. This software is known as a database management system (DBMS). Database management systems are categorized according to the database model that they support. The model tends to determine the query languages that are available to access the database. A great deal of the internal engineering of a DBMS, however, is independent of the data model, and is concerned with managing factors such as performance, concurrency, integrity, and recovery from hardware failures. In these areas there are large differences between products.
For purposes of the present invention, the term “database management system (DBMS)” represents computer software designed for the purpose of managing databases based on a variety of data models. A DBMS is a complex set of software programs that controls the organization, storage, management, and retrieval of data in a database. DBMS are categorized according to their data structures or types. It is a set of prewritten programs that are used to store, update and retrieve a Database.
For purposes of the present invention, the term “database product” refers to a database compatible product that has been loaded into a database.
For purposes of the present invention, the term “data model” is the specification of the information required to describe the structure and organization of data, including geolocation of data, a valid time description of the data and of the way it is packaged with that data.
For purposes of the present invention, the term “data source” refers to any type data source, including data and services.
For purposes of the present invention, the term “discrete time” is non-continuous time. Sampling at non-continuous times results in discrete time samples described as time intervals. For example, a newspaper may report the price of crude oil once every 24 hours. In general, the sampling period in discrete-time systems is constant, but in some cases non-uniform sampling is also used. In contrast to continuous-time systems, where the behavior of a system is often described by a set of linear differential equations, discrete-time systems are described in terms of difference equations. Most Monte Carlo simulations utilize a discrete-timing method, either because the system cannot be efficiently represented by a set of equations, or because no such set of equations exists.
For purposes of the present invention, the term “displaying a contextual square quadrangle on a visual display device”, unless specified otherwise, refers to displaying on the visual display device: an image of the contextual square quadrangle, the contextual geohash code ID of the contextual square quadrangle, and/or any other information about the contextual square quadrangle.
For purposes of the present invention, the term “geocoding” refers to the assignment of alphanumeric codes or coordinates to geographically reference data provided in a textual format. Examples are the two letter country codes and coordinates computed from addresses.
For purposes of the present invention, the term “ebRIM” refers to an ebXML language that provides an extensible content discovery framework on top of CSW. Because it is extensible, ebRIM provides a mechanism to implement situational context from multiple perspectives referenced from a URI that supports a RESTful interface.
For purposes of the present invention, the term “elevation hashing” refers to linking sources based on the height above a reference surface such as mean sea level.
For purposes of the present invention, the term “Gartner” refers to an information technology research and advisory company providing technology related insight.
For purposes of the present invention, the term “geohash set” refers to a set of contextual square quadrangles. A geohash set may be for any type of geographic feature or any portion of a geographic feature. A geohash set is implicitly associated with a 100% confidence value unless explicitly associated with a confidence value.
For purposes of the present invention, the term “geodetic coordinate system” refers to a coordinate system in which position is specified by geodetic latitude, geodetic longitude, and (in the three-dimensional case) ellipsoidal height.
For purposes of the present invention, the term “geodetic datum” refers to a datum describing the relationship of a coordinate system to the Earth. In most cases, the geodetic datum includes an ellipsoid description.
For purposes of the present invention, the term “geographic information system (GIS)” refers to an arrangement of computer hardware, software, and geographic data that people interact with to integrate, analyze, and visualize the data; identify relationships, patterns, and trends; and find solutions to problems. The system is designed to capture, store, update, manipulate, analyze, and display the geographic information. A GIS is typically used to represent maps as data layers that can be studied and used to perform analyses. This term is also known as geospatial information system or geospatial intelligence system.
For purposes of the present invention, the term “geohashing” refers to linking sources based on location.
For purposes of the present invention, the term “geolocation” refers to a mathematical correspondence between position in a grid coordinate system and position in a geodetic coordinate system.
For purposes of the present invention, the term “georeferenceable dataset” refers to a dataset with some additional information such as control points or orientation data that enable the process of georeferencing
For purposes of the present invention, the term “georeferencing” refers to a process of determining the relation between the position of data in the instrument coordinate system and the geographic or map location of the data.
For purposes of the present invention, the term “Hadoop” refers to an open-source software framework that supports data-intensive distributed applications. Hadoop implements a computational paradigm named MapReduce (among others), where the application is divided into many small fragments of work, each of which may be executed or re-executed on any node in the cluster.
For purposes of the present invention, the term “hardware and/or software” refers to functions that may be performed by digital software, digital hardware, or a combination of both digital hardware and digital software. Various functions and methods of the present invention may be performed by hardware and/or software as appropriate.
For purposes of the present invention, the term “latitudinal” refers to a direction along or parallel to a line of latitude on the earth's surface.
For purposes of the present invention, the term “length of a contextual geohash code” refers to the number of ASCII characters in the contextual geohash code, which is proportional to the precision level of that geohash code.
For purposes of the present invention, the term “length of a contextual geohash code” refers to the number of ASCII characters in the contextual geohash code, which is proportional to the precision level of that geohash code.
For purposes of the present invention, the term “level” refers both to the quadtree depth and the corresponding precision of square quadrangle.
For purposes of the present invention, the term “line of latitude” refers to an imaginary line around the earth parallel to the equator.
For purposes of the present invention, the term “line of longitude” refers to any imaginary great circle on the surface of the earth passing through the north and south poles at right angles to the equator.
For purposes of the present invention, the term “longitudinal” refers to a direction along or parallel to a line of longitude on the earth's surface.
For purposes of the present invention, the term “machine-readable medium” refers to any tangible or non-transitory medium that is capable of storing, encoding or carrying instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies of the present invention, or that is capable of storing, encoding or carrying data structures utilized by or associated with such instructions. The term “machine-readable medium” includes, but is not limited to solid-state memories, and optical and magnetic media. Specific examples of machine-readable media include non-volatile memory, including by way of example, semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The term “machine-readable medium” may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more instructions or data structures.
For purposes of the present invention, the term “MapReduce” refers to a programming model for processing large data sets with a parallel, distributed algorithm on a cluster. MapReduce is a framework for processing parallelizable problems across huge datasets using a large number of computers (nodes), collectively referred to as a cluster (if all nodes are on the same local network and use similar hardware) or a grid (if the nodes are shared across geographically and administratively distributed systems, and use more heterogeneous hardware). Computational processing can occur on data stored either in a file system (unstructured) or in a database (structured).
For purposes of the present invention, the term “Microdata” refers to a new Web 3.0 (Semantic Web) GEOINT content specification implemented in XML that supports the management of all data types with associated situational context (what, where, and when). Microdata is capable of managing and characterizing everything in all types of data using Unicode encodings (all content and meta-content), indexing everything for standards-based discovery, and versioning everything from a bi-temporal (valid time and transactional time) perspective.
For purposes of the present invention, term the “microprocessor” refers to a computer processor contained on an integrated circuit chip, such a processor may also include memory and associated circuits. A microprocessor may further comprise programmed instructions to execute or control selected functions, computational methods, switching, etc. Various processes of the present invention may be carried out using a microprocessor.
For purposes of the present invention, the term “motion hashing” refers to linking sources along a path of motion in 4D space i.e., in terms of latitudinal-longitudinal-location, elevation and time.
For purposes of the present invention, the term “National System for Geospatial-intelligence (NSG)” refers to the combination of technology, policies, capabilities, doctrine, activities, people, data, and communities necessary to produce geospatial intelligence in an integrated multi-intelligence, multi-domain environment.
For purposes of the present invention, the term “nested set of contextual square quadrangles” refers to a set of square quadrangles wherein each square quadrangle of increasing precision shares part of its contextual geohash code with the square quadrangle one level above it. For example, a set of square quadrangles having the following contextual geohash code IDs would be a nested set of contextual square quadrangles: 1A, 1AC, 1ACA, 1ACAD, and 1ACADB.
For purposes of the present invention, the term “network” refers to a telecommunications network used to send and receive data. A “network” may be a computer network in which computers exchange data.
For purposes of the present invention, the term “N-Quads” refers to an extension of the N-Triples format that includes context defined as a URI. Within an N-Quad, context is synonymous with the name of an RDF sub-graph and is traditionally used to track a dimension, such as location.
For purposes of the present invention, the term “NSG Community” refers to the community comprised of the following organizations: Intelligence Community (IC), Joint Staff, Military Departments (to include the Services). NGA is the Functional Manager for the NSG Community.
For purposes of the present invention, the term “precision of a contextual geohash code” refers to the length, i.e., the number of ASCII characters in the contextual geohash code.
For purposes of the present invention, the term “precision of a contextual geohash code ID” refers to the length, i.e., the number of ASCII characters in the contextual geohash code ID.
For purposes of the present invention, the term “processor” refers to a device that performs the basic operations in a computer. A microprocessor is one example of a processor. Various functions and methods of the present invention may be performed by one or more processors.
For purposes of the present invention, the term “square quadrangle” refers to a region on earth or other celestial bodies having two latitudinal borders and two longitudinal borders, except at the poles where a “quadrangle” refers to region having one latitudinal border and two longitudinal borders due to convergence.
For purposes of the present invention, the term “storage medium” refers to any medium or media on which data may be stored for use by a computer system. Examples of storage include both volatile and non-volatile memories such as MRAM, ERAM, flash memory, RFID tags, floppy disks, Zip™ disks, CD-ROM, CD-R, CD-RW, DVD, DVD-R, flash memory, hard disks, optical disks, etc.
For purposes of the present invention, the term “storing a contextual square quadrangle to a storage medium”, unless specified otherwise, refers to storing on the storage medium: an image of the contextual square quadrangle, the contextual geohash code ID of the contextual square quadrangle, and/or any other information about the contextual square quadrangle.
For purposes of the present invention, the term “temporal hashing” refers to linking sources based on temporal alignment.
For purposes of the present invention, the term “visual display device,” the term “visual display apparatus” and the term “visual display” refer to any type of visual display device or apparatus such as an LCD screen, touchscreen, a CRT monitor, LEDs, a projected display, a printer for printing out an image such as a picture and/or text, etc. A visual display device may be a part of another device such as a spectrometer, a computer monitor, a television, a projector, a cell phone, a smartphone, a laptop computer, a tablet computer, a handheld music and/or video player, a personal data assistant (PDA), a handheld game player, a head mounted display, a heads-up display (HUD), a global positioning system (GPS) receiver, etc.
For purposes of the present invention, the term “World Geodetic System (WGS)” refers to a standard for use in cartography, geodesy and navigation. The latest revision is WGS84.
DESCRIPTION
Situational context is a mechanism for characterizing information from data. Using the situational context associated with information, in one embodiment, the present invention can dynamically build relationships between disparate sources of information describing common topics to compile knowledge on these topics.
In one embodiment, the present invention employs a number of techniques to discover multidimensional relationships between disparate sources of data and/or information. One of these techniques is called hashing. In one embodiment, the present invention includes hashing techniques for geohashing (linking sources based on location), temporal hashing (linking sources based on temporal alignment), elevation hashing (linking sources based on the height above a reference surface such as mean sea level), motion hashing (linking sources along a path of motion in 4D space based on location, elevation and time), and celestial hashing (linking sources with a common view of the same location on the celestial sphere at the same time as entities move into and out of that view), among others. Many of these techniques build upon other techniques, such as celestial hashing, which can be used to describe the weather and environmental state (solar radiation, lunar radiation) that moves over a specific location and timeframe.
In one embodiment, the present invention provides a method for describing situational context, i.e., what, where and when information for Big Data using multidimensional hashing techniques to dynamically build content level relationships between disparate sources. In this sense, situational context is a mechanism used to transform data into information and then conflate that information into knowledge. The pedigree of these processes frequently includes model-based inferences drawn from different perspectives, including socio-cultural, sensors, or scale; hence, knowledge inherits the situational context of the perspectives, information, and data used to compile and dynamically sustain that knowledge. Challenges for Big Data include capture, storage, search, transform, analysis, and visualization of this data.
One significant type of Big Data is social media, which refers to a group of Web 2.0 mobile apps and web-based Internet applications that enable the creation and exchange of global multi-lingual user-generated content. Social media technologies include a variety of forms, including magazines, Internet forums, blogs, microblogs, wilds, and social networks, among others. Social media is created in all languages, dialects, and many different orthographies as a streaming source of Big Data.
As data volumes grow massive, measured in zettabytes or more, the capability for systems to dynamically discover, characterize, and sustain knowledge drawn from data is becoming an imperative for global commerce, businesses, and especially the US Government. Situational context describes the information state about something real described in data, perspectives in information, and inferred relationships in knowledge. Examples of data include an event like the 2013 Boston Marathon bombing, a blog story, a map, satellite image or a published report from an authoritative source. A related example of information perspectives is the social media opinion of an event like the 2013 Boston Marathon bombing, which can include sentiments ranging from outrage to support for limiting personal liberties. Finally, a small example of knowledge related to this same event could include logistical plans for the Marathon, live data feeds describing reactions to the event, and predictions of likely outcomes related to an evolving event.
Every source of data contains some type of content and some type of meta-information that describes the source of that content. While situational context is much more than traditional metadata, it does encompass any available metadata for a source. Essentially, situational context is used to describe the spatial, temporal, and thematic contexts of data as information to facilitate the conflation of related content drawn from multiple perspectives into knowledge. Knowledge that is managed and sustained to maintain currency provides the best means to affect decision making or provide actionable situational intelligence. Since GEOINT describes data, information, and knowledge that includes geospatial (spatial) and temporal dimensions, a supposition can be made that all data is GEOINT; thus, Big Data is synonymous with GEOINT described for multiple domains and from multiple perspectives, including both historic and predictive ones, supporting a diverse set of communities of interest (COI) globally.
Microdata is a new Web 3.0 (Semantic Web) compatible GEOINT content specification implemented in XML that supports the management of all types of data with associated situational context information. Microdata is capable of managing and characterizing everything found in all types of data using Unicode encodings (all content and meta-content), indexing everything for standards-based discovery, and versioning everything from a bi-temporal (valid time and transaction time) perspective. An example of a new type of GEOINT content is streaming multi-lingual social media data.
Emerging Microdata stores, such as MarkLogic®, can store descriptive or contextual information about GEOINT content n-dimensionally using various XML-based languages, such as Resource Description Framework (RDF). Traditional relational data models, such as Microsoft® Excel® spreadsheets or Oracle® database tables, store data following a structured data model of cells or fields, defined by columns and rows within a table. The resulting structured data can be efficiently managed by modern relational database management systems (RDBMS). However, data that does not fit within a defined relational structure cannot be efficiently stored by these types of systems and is generally lost.
Unstructured information refers to that data that does fit well into a relational table, including text-heavy content but may include dates, numbers, or facts as well. XML and its various languages, such as RDF, provide a robust means (n-dimensional graph-based solution) for describing and then managing unstructured content, such as situational context information. A significant discriminator between Microdata and more tradition relational data stores is that Microdata is specifically designed to store everything about everything in context. Thus, by using Microdata to manage GEOINT content, any aspect of that content can be associated with any number of esoteric or unique facts, perspectives, or versions.
As a Web 3.0 Semantic Web capability, Microdata is specifically designed to accommodate the massive content volumes associated with Big Data, contextually aligned in space, time, and thematic content. Within Microdata, everything is indexed and versioned using Unicode encodings supporting all languages. Unlike traditional RDF, which employs N-Triple structures to describe RDF graphs, Microdata employs N-Quads, which associates context with each N-Triple. From an Industry perspective, this type of context is used to name an RDF graph.
The context value within each N-Quad is a Uniform Resource Identifier (URI) that describes a context resource within an Open Geospatial Consortium (OGC) Catalog Service for the Web (CSW) ebRIM profile (CSW-ebRIM) discovery framework. Within this standards-based framework, global conflation business logic is included to dynamically build relationships between disparate GEOINT sources at the content level (sub-feature, sub-pixel, attribute). In one embodiment, the present invention may be used to describe these situational contexts.
Once situational context has been described, very large and complex RDF graphs can be defined as N-Quads managed within a Hadoop File System (HDFS), which supports Big Data analytic operations in MapReduce. This very large distributed management structure supported by a robust context-aware content discovery framework (CSW-ebRIM) provides the means for the dynamic selection of context specific sub-graphs to be extracted from HDFS and visualized or further analyzed efficiently. Thus, situational context described within Microdata represents an extensible, standards-based, domain specific description that can include multiple perspectives and versions, as well conflation relationships between disparate sources.
CSW-ebRIM is an OGC standard for exposing a catalog of geospatial records on the Internet via HTTP. CSW is analogous to a card catalog in a library and defines common interfaces to discover, browse, and query metadata about data, services, and other resources. CSW is comprised of multiple profiles, including ebRIM, which is extensible and contains both a Registry and a Repository. The Registry objects point to the associated Repository items. Each repository item (e.g. an HTML document) has a Uniform Resource Name (URN), which is a URI that uses the URN scheme. The URN allows the repository item to be readily retrieved from the Registry using a simple GET request (e.g. issued from a web mapping client such as a browser).
The ebRIM provides a standards-based extensible content discovery framework that can be tailored to the specific needs of a COI while retaining more generic cataloging attributes to facilities domain specific content discoveries from a broader audience. In one embodiment of the present invention, new situational context extensions based on the contextual geohashing method of the present invention can be defined with ebRIM from multiple perspectives and tailored to serve specific COIs. These contexts would be referenced from a URI that could support a RESTful interface to override aspects of the defined situational context. This means that any given situational context associated with content can be independently discovered and repeatedly referenced by multiple resources via a standards-based web service.
In one embodiment of the present invention, additional discovery frameworks are included within the contextual geohashing method of the present invention, including an absolute dimensional referencing system that cross-references entities described via a UUID and contextual codes. Conflation is a mechanism that relates or links descriptions of the same thing (entity) found in distinct and separate sources. For instance, a lighthouse can be represented differently in three distinct data sources as an icon on a map, a detailed floor plan of the lighthouse, and a report describing the history of that lighthouse. Because all three sources are describing the same real entity, conflation can be used to build relationships between each of these data sources (at the content level) to build a more comprehensive knowledge-based description of the lighthouse entity itself. Dynamic conflation is a Big Data analytics method that leverages situational context to automatically build (through inferences) conflated relationships with corresponding confidence values (contexts) for each of these relationships. These automatically built relationships can be validated and/or enhanced by humans to create additional contextual versions for these relationships. All of the data that is linked is captured and described as evidence to support the rationale for establishing each link or relationship.
In one embodiment, the contextual geohashing method of the present invention enables the dynamic conflation of disparate sources at the content level (sub-feature, sub-pixel, attribute) by building relationships between data with situational context (information) using various Big Data analytic methods. One of these methods utilizes multidimensional hashing techniques that quantize a dimension of situational context information. A hashing technique is a method that uses a hash function to map a specific type of data of variable length into a set of fixed length data. From a relationship building methodology, hashing provides a dynamic means for linking (building relationships) disparate data content. Some of the hashing techniques supported by one embodiment of the contextual geohashing method of the present invention include: geohashing, temporal hashing, elevation hashing, motion hashing, and celestial hashing.
In one embodiment, the contextual geohashing method of the present invention provides an extensible framework for describing and characterizing situational contexts that can be encoded and decoded into Microdata. In one embodiment, the contextual geohashing method of the present invention may define situational context using a number of location-based, time-based, and thematic-based schemes. Each scheme quantizes the data dimensions of that scheme at a specified precision or resolution. For instance, in one embodiment, the contextual geohashing method of the present invention may provide a conflation surface for all high resolution orthorectified commercial imagery globally at a specified precision (e.g., 0.3 m, 5 mm, 1 ym) sequenced in time, by vendor and sensor. This means that every sub-pixel in every commercial image is quantized and related to every other corresponding sub-pixel in all overlapping images.
Just to describe the pixels in this surface at 0.3 meter precisions requires 9,007,199,254,740,990 (nine quadrillion, seven trillion, one hundred ninety-nine billion, two hundred fifty-four million, seven hundred forty thousand, nine hundred ninety) geospatial hashing codes. In one embodiment of the present invention, this seemingly impossibly large number can be addressed via the contextual geohashing method of the present invention by scalable compression techniques executing within a Big Data distributed computing environment using the Hadoop File System (HDFS) distributed across a large number of systems. Thus, in one embodiment, the contextual geohashing method of the present invention can dynamically conflate high resolution global imagery at the sub-pixel level, regardless of the type (full motion video, hyper-spectral), or volume of imagery, as well as any other type of data.
Situational context can be defined in multiple dimensions, including both geospatial and temporal dimensions among many others. Hashing is a technique designed to take complex data and relate it to similar data with the same dimensionality. Geohashing is a hierarchical latitude/longitude geocoding system that is used to index or address geospatial locations anywhere on the Earth. There are several geohashing solutions available, most of which merely describe a single point or a single quadrangle.
In one embodiment, the contextual geohashing method of the present invention provides an infinitely scalable areal notation scheme that scales in multiple dimensions, including temporal ones. This includes geohashing for any type of GEOINT content, including imagery/pixels, points, polylines, polygons, and complex areas. Hence, in one embodiment, the contextual geohashing method of the present invention can describe any feature on the Earth at millimeter precision or finer as necessary.
Temporal hashing is a method that quantizes date and time values into defined spans of time or intervals. This method replaces the continuous concept of an instant into a potentially infinitesimal interval. Sophisticated temporal hashing solutions, such as the contextual geohashing method of the present invention, can employ temporal interval comparisons to determine if multiple temporal representations can hash from multiple perspectives. Table 1 of FIG. 1 shows temporal interval comparisons for examples of the temporal conflation rules included within one embodiment of the contextual geohashing method of the present invention.
In one embodiment, the contextual geohashing method of the present invention may use perspectives of dimensional situational context to describe “fuzzy” content or content that includes ambiguities, such as geospatial or temporal. An example of a fuzzy feature might be the area controlled by a gang. Rival gang members, local police, and tourists may all have different perceptions of what and where this boundary is as it evolves through time. An example of fuzzy temporal data is the effect highway congestion can have on commuting times.
Using multiple dimensional hashing techniques, in one embodiment, the contextual geohashing method of the present invention provides the basis for implementing a global conflation model that utilizes the situational context of the data to conflate at the content level (sub-feature, sub-pixel, attribute). Given the potential volume of computation required for this type of activity, in one embodiment, the contextual geohashing method of the present invention employs hashing methods to support the Hadoop File Systems (HDFS) and MapReduce operations for Big Data analytics.
The terms data, information, and knowledge represent three overlapping abstract concepts. Data are qualitative and/or quantitative values that typically result from some type of measurement. Data without any context is difficult to interpret. Information results from the association of context (applying meaning) with data, generally from a defined set of perspectives. Knowledge is the collective assembly of related information drawn from across multiple perspectives. In this sense, information describes what data is and where and when it is relevant. Knowledge can then be thought of why and how the information is useful.
A situational context describes a framework for interpreting data (applying meaning) as information from a defined perspective and then relating disparate information into codified knowledge. Data is transformed into information through the association of multidimensional contexts, such as where the data is located, when it is relevant, and what it represents. The normalization of these contexts is one aspect of the framework that can be used to define situational context. Another aspect of this framework is the relating or conflation of disparate information using context.
A situational context is comprised of a number of multidimensional contexts. Many of these contexts are described as continuous phenomena. In one embodiment, the contextual geohashing method of the present invention provides a structured means to discretize various types of context utilizing a quantizing method that always associates a degree of precision with any contextual value. In this sense, in one embodiment, the contextual geohashing method of the present invention describes the geospatial context of an entity using a raster-based analogy rather than a vector one, where raster-based depictions are comprised of regions of discrete pixels that fill a continuous space, and the vector-based depictions are comprised of infinite geometries, such as points, lines, and polygons.
In one embodiment, the contextual geohashing method of the present invention employs various hashing schemes as the quantizing method for each dimensional context. Hashing is a deterministic method of mapping a complex representation into a simpler one. The hashing function is defined by an algorithm. By its very nature, most hashing functions are “lossy,” i.e., some details are sacrificed or lost in exchange for new functionality; whereas, a lossless process loses no details.
There are a number of different types of dimensions that can be used to characterize data into information, just as there are many different perspectives that can be identified to interpret data as information. Two of the fundamental and broadly defined dimensions of data are space and time. These dimensions can be further describes as location, timeframe, elevation, and movement, which describes real entities that occupy space and move through time. Additional contexts can distinguish between relative and absolute frames of reference, environmental conditions (gravity, radiation), weather, and composition for instance. Each of these contexts is also described historically, presently, and predictively through time.
Contextual geohashing schemes according to one embodiment of the present invention are described as codes and are broadly defined within two format classes: text and binary. Text formats are named IDs and are designed to be human readable but are less efficient to process in volume. IDs are concise, since additional attributes can be associated with the hash codes externally. Binary formats are named tags and are specifically tuned for Big Data analysis operations, such as MapReduce. In one embodiment of the present invention, tags follow a standard hash code template that includes the following components: a magic number to identify the object as a subclass of a contextual geohashing scheme of the present invention, a hash code class that corresponds to hashing schemes; a hash code class type that provides numerous profiles for each hashing scheme, a size of object in 64-bit words.
In one embodiment, the contextual geohashing method of the present invention includes the following foundational multidimensional hashing schemes: contextual geohash codes for geohashing, contextual temporal hash codes for temporal hashing; contextual elevation hash codes for elevation hashing, contextual motion hash codes for hashing motion; contextual celestial hash codes for hashing the view of astronomical objects against a celestial sphere. Contextual geohash codes hash latitude and longitude locations on the Earth. Contextual temporal hash codes hash dates and times. Contextual elevation hash codes uniquely hash elevations, altitudes, or heights both above and below a defined datum. Motion context hash codes describe the movement of an object with a defined location, elevation, and timeframe to a new location, elevation, and timeframe. Contextual celestial hash codes enable the description of celestial bodies or other objects, such as weather, over a specified location and timeframe including motion of those celestial bodies or other objects.
In one embodiment, the contextual geohashing method of the present invention includes other contextual geohashing schemes associated with other foundational schemes. Some of these schemes are used to describe reference surfaces for gravity; pressure; various types of radiation; weather (including climate and weather predictions); and surface, subsurface, and super-surface composition (air/water/soil/rock/geology); among others.
A contextual geohash code technique for hashing geospatial coordinates described in latitude, longitude, and a defined datum, such WGS84, at a specified precision (1 m). Traditional geohashing techniques, such as Geohash from www.geohash.org, hash a single geospatial point. Contextual geohashing is designed to hash any type of geospatial feature, including points, lines, polygons, and complex areas as sets of contextual geohash codes. A contextual geohash code is also infinitely scalable, which means that a contextual geohash code can support user defined precisions, such as 1 km, 5 mm, or 1×10 −24 m (1 yoctometer—the smallest limit for SI defined standard units in meters).
Contextual geohash codes are defined as square quadrangles sequenced following a Z-order (Morton code) curve within a modified quadtree structure. A quadrangle is a region on the Earth bounded by the graticule of lines of latitude and longitude as parallels and meridians. Meridians are defined as great-circles and parallels are defined as small circles except at the Equator or the poles. Due to convergence, the quadrangle parallel edge away from the Equator is slightly smaller than the parallel edge closer to the Equator; whereas, the meridional edges are both the same. A square quadrangle is one where the size in angular units, such as degrees, is the same for all edges of a quadrangle. FIG. 2 shows a contextual square quadrangle 212 extruded from a graticule 214 . The length of each edge in a square quadrangle measured in angular units, such as degrees, is identical; hence, a square quadrangle. However, the length of an edge in a square quadrangle measured in length units, such as meters, is only the same for the two meridional edges and is different for each of the parallel edges. Meridional edges are great-circle arcs and are measured as great-circle distances, which represent the shortest distance between any two points on the Earth (assuming a spherical datum defining the figure of the Earth). Geodesics describe the shortest distance on the Earth when a more accurate ellipsoidal or geodetic datum is used as the figure of the Earth. Parallel edges follow rhumb lines (loxodromes) or lines of constant East or West bearing, which are not great-circle arcs.
A contextual geospatial quadrangle is described by a contextual geohash code ID, which is anchored to the southwest corner of the quadrangle with an assumed datum of WGS84. Contextual geohash codes are described by a variety of notations. A contextual geohash code ID is an ASCII string (human readable) of variable length, where the length of the ID string is proportional to the depth level of the quadtree comprised of square quadrangles used to describe that quadrangle. FIG. 3 shows contextual geohash for level 0 through level 2 according to one embodiment of the present invention. Levels beyond level 2 continue with this hierarchical pattern. Contextual geohash codes for level 0 are shown in diagram 312 , contextual geohash codes for level 1 are shown in diagram 314 , and contextual geohash codes for level 2 are shown in diagram 314 .
A contextual geohash code ID has a standard form with four exceptions. The first character in the ASCII standard form must be either “0” for the western hemisphere or “1” for the eastern hemisphere. This denotes level 0, where levels describe both the quadtree depth and the corresponding precision of the described quadrangle. Starting with level 1, the prior region (in this case a hemisphere) is subdivided into four square quadrangles following a Z-order pattern labeled “A, B, C, or D”. Quadrangle “A” is always the northwest component; Quadrangle “B” is always the northeast component; Quadrangle “C” is always the southwest component; and Quadrangle “D” is always the southeast component. Following this scheme, any contextual square quadrangle can be subdivided into four square quadrangles to define a new level.
By design, quadtree structures are spatially hierarchical and therefore highly compressible. These features enable a contextual geohash code ID to support an infinite quadtree depth and corresponding precision, but a practical limit can be drawn from the International System of Units (SI) used by the metric system. The SI unit of length is the meter (m) and the smallest defined meter is the yoctometer, which is defined as 1×10-24 m. Thus, a contextual geohash code ID describes a lettered pattern (A-D) repeatedly until the appropriate depth level is reached to describe the precision for the contextual geohash code ID. For example, if a level 4 contextual geohash code ID is described for (0° N, 0° E) is would be labeled as “1ACCC”. To reduce the precision of this ID to level 3, the last character is truncated producing “1ACC”.
Table 2 of FIG. 4 shows contextual geohash code IDs at 10 meter precision for (0° N, 0° E) according to one embodiment of the present invention.
In some cases, a higher level quadrangle may need to be represented at a lower level precision. When the extra precision is warranted, subsequent levels for precision are labeled with “E”. If this same quadrangle (0° N, 0° E) needed to be described with level 7 precision (1.4063° or 156,262.5 m in meridional distance), it would be labeled as “1ACCCEEE”.
FIG. 5 shows contextual geohash code compression examples and illustrates how contextual geohash codes can be compressed to either retain the original precision or to generalize that precision. In this figure, each column, i.e., columns 512 , 514 , 516 and 518 , represents a different example. In column code sets 522 , 524 , 526 and 528 each represent a set of codes that can be compressed into the contextual geohash code at the top of each column following the quadtree notational scheme. In columns 512 and 514 the contextual geohash code at the top of the column has a different precision than the other contextual geohash codes in the column. In columns 516 and 518 the contextual geohash code at the top of the column has the same precision as the other contextual geohash codes in the column. The “E” label is used to retain the precision of a compressed quad or complete set of contextual geohash codes.
In one embodiment of the present invention in which alphanumeric codes are used for contextual geohash code IDs there are four exception cases used with the contextual geohash code IDs to describe the poles, to describe the whole Earth, and to describe an unspecified location. The labels for these exceptions are as follows: (1) a single character of “&” indicates the North Pole, (2) a single character of “=” indicates the South Pole, (3) a single character of “#” indicates the whole Earth, including both poles, and (4) a single character of “?” indicates an unspecified location, which is used in conjunction with other types of hash codes, such as temporal hash codes.
In one embodiment of the present invention anchor point for the southernmost contextual geohash code quadrangles is slightly greater than the South Pole by an imperceptible distance and does not include the South Pole. The northernmost contextual geohash code ID quadrangles do not include the North Pole, but fall just short of it by an imperceptible distance.
Similar to contextual geohash codes, a contextual geohash tag is a binary object that describes a contextual geohash code specifically designed for use in Big Data operations, such as MapReduce. Contextual geohash tags are numbered sequentially as they are defined, starting with contextual geohash tag #1. Because there are a number of different computing architectures, many with different optimization requirements, contextual geohash tags may be implemented in a number of different types, where each type is uniquely named and described via a specification. Because contextual geohash codes are optimized for Big Data analytics, tag specifications are described at the octet or bit level within a specified word size, which is frequently tailored to 64-bits.
Whenever defining binary objects specifications, the details for how information is encoded (byte-ordering or endianness). A big-endian machine stores the most significant byte first and a little-endian machine stores the least significant byte first. In one embodiment, the method and apparatus of the present invention can support any type of binary architecture with the definition of different types. FIG. 6 shows 64-bit endian examples to illustrate the differences between these byte ordering methods.
In one embodiment of the present invention, all contextual geohash tags include the same header, which comprises the first word or 64-bits of the type. There are three components to the type header: (1) magic number, which corresponds to “GZ” in ASCII; (2) type number (there are 65,535 possible types); and (3) the size, which describes the number of 64-bit words in the type. FIG. 7 shows the logical layout of a contextual geohash tag header 702 .
In one embodiment of the present invention, contextual geohash tag #1 describes the binary type for a contextual geohash tag code that is based upon the WGS84 datum and includes up to 110 levels. The specific precision for level 110 is 154.087 ym (one hundred fifty-four thousand, eighty-seven hundred-octillionths of a meter). The logical type layout for a contextual geohash tag #1 according to one embodiment of the present invention is shown in FIG. 8 .
Unlike traditional geohashing schemes, in one embodiment, the contextual geohashing method of the present invention uses a set of contextual geohash codes to describe and delimit a region with an explicit precision. This means that contextual geohash codes can be used to describe any type of feature, ranging from a point to a complex area including islands and/or disjointed regions anywhere on the Earth. Contextual geohash code sets can include extremely large numbers of contextual geohash codes, especially if a complex region is described with a high level of precision.
FIG. 9 shows contextual geohash set compression examples. Left box 912 represents an uncompressed contextual geohash set, including three subsets (shown in boxes), i.e., subsets 922 , 924 and 926 , that could be compressed. Middle box 932 represents a corresponding compressed set and the right box 934 represents a corresponding compressed set that maintains the precision of the original sources.
Compression occurs once the set has been sorted (MapReduce operation on large sets) and identical adjacent codes are thinned, a quad exists (A-D codes for the same level can be compressed to the level above), or a superset exists. A superset is a higher level that encompasses a lower level.
Fuzzy features are geospatial objects that are described with some degree of ambiguity for the spatial extents of those objects. FIG. 10 illustrates this concept through concentric colored rings 1012 (shown as different fill patterns in FIG. 10 ) within a feature extent, i.e., geographic entity 1014 (England and Wales). This type of fuzzy feature can be implemented within one embodiment of the present invention by defining a set for each of the colored sub-regions. Each set would also be associated with a description of the confidence value and method used to estimate or infer the likelihood of that sub-region being part of the actual feature. By combining contextual geohash code sets into larger geohash code sets, any time of geospatial ambiguity can be characterized and described.
Because each contextual geohash set can be filtered from any other set of sub-feature sets, multiple perspectives can be supported for how fuzziness is defined for any given feature. In one embodiment, fuzziness may be applied to all other dimensional codes of the contextual geohashing method of the present invention.
A contextual temporal geohash code of the present invention is a technique for hashing descriptions of time in temporal units, such as seconds or years. The contextual geohashing method of the present invention may be used with several depictions of time. In one embodiment of the present invention contextual temporal geohash codes may be aligned with the ISO 8601 specification for data and time.
For example, in one embodiment of the present invention, contextual temporal geohash tag #1 defines an extended time format based on ISO 8601 that spans from a trillion years ago to a trillion years in the future with a precision measured in yoctoseconds (10 −24 s). FIG. 11 shows a contextual temporal geohash tag time span range 1102 for a detailed description of the date layout for this tag. As shown in FIG. 11 , contextual temporal geohash tag #1 extends ISO 8601 to address a trillion years in the past and future at the precision of a yoctosecond (10 −24 s). Time spans that span year zero must be split into a negative tag followed by a positive tag.
Confidence
Confidence is used to describe the likelihood that something occurs at the place described by contextual geohash codes. One embodiment of confidence is “fuzzy” geography or places. In each of these examples, some level of uncertainty is associated with the description of place. Any given description of place can be represented from differring perspectives including differing extents and associated confidence values. For instance, The U.S. State Department may define a given international boundary authoritatively from the U.S. perspective. A local tribesman living near the border of that international boundary may define this same border differently from his local cultural perspective.
Boundary
A boundary is used to delineate a place described using contextual geohash tags. Boundaries are associated with confidence values and may be distinct or fuzzy. Implemented as sets of contextual geohash codes, boundaries can describe any place with a multitude of confidences asscoaited withinn a variety of perspectives that are valid with defined time spans, which can also be defined with ambiguity or fuzziness.
Search
Within Big Data, the discovery of distinct data is challenging given the overall volume of data as well as the distributed fashion in which that data is stored and/or managed. Contextual geohash codes represent meta information that can be associated with data to provide a fast and scalable means to deterministacally identify relevant data given a sepcified set of seach criteria. In this sense, disparate data can be dynamically conflated or related to other data during a search process.
Additional features of the present invention are described in the examples below.
EXAMPLES
Example 1
Table 3 of FIG. 12 shows contextual geohash code IDs at 5 meter precision for the city of Chantilly, Va.
Example 2
FIG. 13 is a diagram showing an example of a contextual elevation geohash tag according to one embodiment of the present invention.
Example 3
FIG. 14 shows window 1402 on a visual display device of a computer implementing one embodiment of a method according to the present invention. Window 1402 provides a global view 1412 that includes contextual square quadrangles 1422 , 1424 , 1426 , 1428 and 1430 according to one embodiment of the present invention. Contextual square quadrangles 1422 , 1424 , 1426 , 1428 and 1430 are a nested set of contextual square quadrangles. A hierarchical selection menu 1452 shows the levels and contextual geohash code IDs of quadrangles displayed in window 1402 , i.e., contextual square quadrangles 1422 , 1424 , 1426 , 1428 and 1430 . Hierarchical selection menu 1452 allows a user to select that contextual geohash point be displayed.
Example 4
FIG. 15 shows window 1502 on a visual display device of a computer implementing one embodiment of a method according to the present invention. Window 1502 provides a medium view 1512 that includes contextual square quadrangles 1522 , 1524 , 1526 , 1528 and 1530 according to one embodiment of the present invention. Contextual square quadrangles 1522 , 1524 , 1526 , 1528 and 1530 are a nested set of contextual square quadrangles. Also shown in window 1502 is a contextual geohash point 1542 that is indicated by a thumbtack icon. A hierarchical selection menu 1552 shows the levels and contextual geohash code IDs of quadrangles displayed in window 1502 , i.e., contextual square quadrangles 1522 , 1524 , 1526 , 1528 and 1530 . Hierarchical selection menu 1552 allows a user to select that contextual geohash point 1542 be displayed.
Example 5
FIG. 16 shows window 1602 on a visual display device of a computer implementing one embodiment of a method according to the present invention. Window shows a regional view 1612 that includes contextual square quadrangles 1622 , 1624 , 1626 , 1628 and 1630 according to one embodiment of the present invention. Contextual square quadrangles 1622 , 1624 , 1626 , 1628 and 1630 are a nested set of contextual square quadrangles. Also shown in window 1602 is a contextual geohash point 1642 that is indicated by a thumbtack icon that is located in contextual square quadrangle 1630 . A hierarchical selection menu 1652 shows the levels and contextual geohash code IDs of quadrangles displayed in window 1602 , i.e., contextual square quadrangles 1622 , 1624 , 1626 , 1628 and 1630 . Hierarchical selection menu 1652 allows a user to select that contextual geohash point 1642 be displayed.
Example 6
FIG. 17 shows window 1702 on a visual display device of a computer implementing one embodiment of a method according to the present invention. Window 1702 shows a city view 1712 that includes contextual square quadrangles 1722 , 1724 , 1726 , 1728 and 1730 according to one embodiment of the present invention. Contextual square quadrangles 1722 , 1724 , 1726 , 1728 and 1730 are a nested set of contextual square quadrangles. Also shown in window 1702 is a contextual geohash point 1742 that is indicated by a thumbtack icon. A hierarchical selection menu 1752 shows the levels and contextual geohash code IDs of quadrangles displayed in window 1702 , i.e., contextual square quadrangles 1722 , 1724 , 1726 , 1728 and 1730 . Hierarchical selection menu 1752 allows a user to select that contextual geohash point 1442 be displayed.
Example 7
FIG. 18 shows window 1802 on a visual display device of a computer implementing one embodiment of a method according to the present invention. Window 1802 shows a 5 m conflation scale view 1812 of contextual square quadrangles 1822 , 1824 , 1826 , 1828 and 1830 according to one embodiment of the present invention. Contextual square quadrangles 1822 , 1824 , 1826 , 1828 and 1830 are a nested set of contextual square quadrangles. Also shown in window 1802 is a contextual geohash point 1842 that is indicated by a thumbtack icon that is located in contextual square quadrangle 1830 . A hierarchical selection menu 1852 shows the levels and contextual geohash code IDs of quadrangles displayed in window 1802 , i.e., contextual square quadrangles 1822 , 1824 , 1826 , 1828 and 1830 . Hierarchical selection menu 1852 allows a user to select that contextual geohash point 1842 be displayed.
Example 8
FIG. 19 shows window 1902 on a visual display device of a computer implementing one embodiment of a method according to the present invention. Window 1902 shows a 0.6 m conflation scale view 1912 of contextual square quadrangles 1922 , 1924 , 1926 , 1928 and 1930 according to one embodiment of the present invention. Also shown in window 1902 is a contextual geohash point 1942 that is indicated by a thumbtack icon. A hierarchical selection menu 1952 shows the levels and contextual geohash code IDs of quadrangles displayed in window 1902 , i.e., contextual square quadrangles 1922 , 1924 , 1926 , 1928 and 1930 . Hierarchical selection menu 1952 allows a user to select that contextual geohash point 1942 be displayed.
Example 9
FIG. 20 shows window 2002 on a visual display device of a computer implementing one embodiment of a method according to the present invention. Window 2002 shows a 5 mm conflation scale view 2012 of a contextual square quadrangle 2022 according to one embodiment of the present invention. Hierarchical selection menu 2052 allows a user to select that contextual geohash point be displayed. In FIG. 20 a user has selected information 2062 for contextual square quadrangle 2022 on hierarchical selection menu 2052 , thereby causing information pop-up 2064 to appear providing a contextual geohash code ID for contextual square quadrangle, level and meridional distance for the square quadrangle.
Example 10
Confidence Example
Confidence provides a means of characterizing ambiguity associated with the delineation of a place. This ambiguity may arise from scalar differences in the use of data, inaccuracies associated with the delineation or measurement of data, and/or differences in perspective drawn from a group of individuals about where a place exists.
Example 11
Boundary Examples
In one embodiment of the present invention, boundaries are described by the outside edge of a set of contextual geohash codes included in a boundary set. The boundary set may be further described by confidence subsets, which characterize the likelihood that the subregion is included in the boundary as defined by a source or perspective. For example, in the United States, a major metropolitan area is generally described by an urban center surrounded by suburbs. Exactly which suburbs are included may change by perspective and may evolve over time as a metropolitan area grows or declines.
Various types of geospatial boundaries can be described using the contextual geohash code of the present inveniton, including boundaries such as points, lines, polygons, complex polygons (including holes and/or distint collections of non-continguos polygons), as well as volumes extending both above and/or below the surface of the Earth or other reference body.
FIG. 21 shows a point geohash set 2112 in grid 2114 in which each confidence set has a different fill pattern. Each confidence set shown in FIG. 21 is defined by a confidence value. Confidence set 2122 is a 100% confidence set, i.e., the confidence value for the single contextual square quadrangle 2124 (black) in confidence set 2122 is 100% and corresponds to a geospatial point. Surrounding confidence set 2122 is a confidence set 2132 of contextual square quadrangles 2134 (light gray). Confidence set 2132 is a 95% confidence set, i.e., contextual square quadrangles 2134 each have a confidence value of at least 95%. Surrounding confidence set 2132 is a confidence set 2142 of contextual square quadrangles 2144 (medium gray). Confidence set 2142 is a 90% confidence set, i.e., contextual square quadrangles 2144 each have a confidence value of at least 90%. In this example, the point is described with the same level of precision (cell size) where the real world feature being described is 90+% likely to occur within relevant geolocations, i.e. the combination of confidence set 2122 , confidence set 2132 and confidence set 2142 . The 100% confidence set may be referred to as the real world feature itself. In this example, confidence set 2122 may be referred to as a geospatial point feature. Color values, transparancy values, statistical model results or other attributes may be used to convey the confience values as well.
FIG. 22 shows a line segment geohash set 2212 in a grid 2214 which each confidence set has a different fill pattern. Each confidence set shown in FIG. 22 is defined by a confidence value. Confidence set 2222 is a 100% confidence set, i.e., the confidence value for each contextual square quadrangle 2224 (black) in confidence set 2222 is 100% and corresponds to a geospatial linear feature 2226 . Surrounding confidence set 2222 is a confidence set 2232 of contextual square quadrangles 2234 (light gray). Confidence set 2232 is a 95% confidence set, i.e., contextual square quadrangles 2234 each have a confidence value of at least 95%. Surrounding confidence set 2232 is a confidence set 2242 of contextual square quadrangles 2244 (medium gray). Confidence set 2242 is a 90% confidence set, i.e., contextual square quadrangles 2244 each have a confidence value of at least 90%. In this example, geospatial linear feature 2226 is described with the same level of precision (cell size) where the real world feature being described is 90+% likely to occur within the relevant geolocations, i.e. the combination of confidence set 2222 , confidence set 2232 and confidence set 2242 . The 100% confidence set may be referred to as the real world feature itself. In this example, confidence set 2222 may be referred to as a geospatial linear feature. This example could also be described with a lower level of precision, which would represent the feature with a width of multiple quadrangles.
FIG. 23 shows a complex polygon geohash set set 2312 in a grid 2314 in which each confidence set has a different fill pattern. Each confidence set shown in FIG. 23 is defined by a confidence value. Confidence set 2322 is a 100% confidence set, i.e., the confidence value for each contextual square quadrangle 2324 (black) in confidence set 2322 is 100% and corresponds to a geospatial complex polygon feature 2326 that includes a hole 2328 . Surrounding confidence set 2322 is a confidence set 2332 of contextual square quadrangles 2334 (light gray). Confidence set 2332 is a 95% confidence set, i.e., contextual square quadrangles 2334 each have a confidence value of at least 95%. Surrounding confidence set 2332 is a confidence set 2342 of contextual square quadrangles 2344 (medium gray). Confidence set 2342 is a 90% confidence set, i.e., contextual square quadrangles 2344 each have a confidence value of at least 90%. In this example, geospatial complex polygon feature 2326 is described with the same level of precision (cell size) where the real world feature being described is 90+% likely to occur within the relevant geolocations, i.e. the combination of confidence set 2322 , confidence set 2332 and confidence set 2342 . The 100% confidence set may be referred to as the real world feature itself. In this example, confidence set 2222 may be referred to as a geospatial linear feature.
FIG. 24 illustrates how geohash set can be used to describe a political boundary, i.e. state boundary 2412 which is the state boundary for for the state of Pennsylvania. Shown in grid 2420 is a boundary geohash set 2422 consisting of contextual square quadrangles 2424 (light gray) that include state boundary 2412 and that each have a confidence value of 100% with respect to including state boundary 2412 . Also shown in grid 2420 is an interior geohash set 2432 (medium gray) consisting of contextual square quadrangles 2434 that each have a confidence value of less than 100% with respect to including state boundary 2412 .
Although one precision level is shown in FIG. 24 , any precision level may be used to describe a boundary, such as the state boundary shown in FIG. 24 . For example, for any precision level, contextual square quadrangles that are known to includes the state boundary are coded with a 100% confidence value and each interior contextual square quadrangle are coded with the appropriate confidence level. A first confidence set can be formed from the contextual square quadrangles that have a 100% confidence value. A a second confidence set can then be formed of interior contextual square confidence quadrangles that each have at confidence value of at least a particular threshold confidence value, such as at least 95%. The state boundary can then be defined as a geohash set including the first and second confidence sets.
Example 12
Search Example
Because geohash code IDs are globally unique, code matching schemes can be efficiently employed to compare a corpus of data described with geohash IDs with a set of search IDs. If any corpus ID matches any search ID then the corresponding data describe a common place or an aspect of a place depending upon the confidence associated with the match IDs.
Example 13
Contextual Temporal Hashing Example
Contextual temporal hashing characterizes the temporal extent (occurrence and duration) and potential periodicity of an event. Similar to geohash codes, temporal hash codes may include confidence, which is used to character temporal ambiguity associated with an event from a defined perspective. For instance, a temporal hash code might be defined as Monday, 19 May 2014 as a standard business day, which has the definition of a non-holiday or weekend day from 9 AM local to 5 PM local. This temporal hash code include a confidence value of 12 PM-1 PM as a likely non-working lunch hour.
Example 14
Contextual Elevation Hashing Example
Because geohash code IDs are explicity defined as a volume from the center of the Earth extending out to intercept the cestial sphere at a specified time, these volumes can be segregated into various subvolumes. When a subvolume is bounded by the surface of the Earth within a defined range of height above a datum, such as mean sea level, then the hashing scheme describes elevation hashing. Biomes or physiographic regions that are associated with specific elevation ranges can be hashed this way. Another example is elevation hashing of data by the contour ranges defined by topographic maps.
Example 15
Contextual Motion Hashing Example
Contextual motion hashing can describe the motion of objects relative to the Earth, such as a car traveling down a road or a thunder storm moving across a region.
Example 16
Contextual Celestial Hashing Example
Celestial hashing describes the orbit and/or rotation of the Earth with respect to another celestial body, such as the sun, moon, stars, or other planets. The likely occurrence of sunlight, twilight, night or moonlight at a defined location and time is the aspect that is hashed.
All documents, patents, journal articles and other materials cited in the present application are incorporated herein by reference.
While the present invention has been disclosed with references to certain embodiments, numerous modification, alterations, and changes to the described embodiments are possible without departing from the sphere and scope of the present invention, as defined in the appended claims. Accordingly, it is intended that the present invention not be limited to the described embodiments, but that it has the full scope defined by the language of the following claims, and equivalents thereof. | Described is a method and apparatus for constructing a boundary comprising a set of contextual square quadrangles. Also described is a method and apparatus for searching a set of contextual square quadrangles. | 6 |
RELATED APPLICATIONS
[0001] This application is a continuation under 37 C.F.R. 1.53(b) of U.S. Ser. No. 09/096,749, filed Jun. 12, 1998, which claims priority under 35 U.S.C. 119(e) to provisional application U.S. Ser. No. 60/049,410, filed Jun. 12, 1997, which applications are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of the production and selection of binding and catalytic polypeptides by the methods of molecular biology, using both combinatorial chemistry and recombinant DNA. The invention specifically relates to the generation of both nucleic acid and polypeptide libraries derived therefrom encoding the molecular scaffolding of Fibronectin Type III (Fn3) modified in one or more of its loop regions. The invention also relates to the “artificial mini-antibodies” or “monobodies,” i.e., the polypeptides comprising an Fn3 scaffold onto which loop regions capable of binding to a variety of different molecular structures (such as antibody binding sites) have been grafted.
BACKGROUND OF THE INVENTION
Antibody Structure
[0003] A standard antibody (Ab) is a tetrameric structure consisting of two identical immunoglobulin (Ig) heavy chains and two identical light chains. The heavy and light chains of an Ab consist of different domains. Each light chain has one variable domain (VL) and one constant domain (CL), while each heavy chain has one variable domain (VH) and three or four constant domains (CH) (Alzari et al., 1988). Each domain, consisting of ˜110 amino acid residues, is folded into a characteristic β-sandwich structure formed from two β-sheets packed against each other, the immunoglobulin fold. The VH and VL domains each have three complementarity determining regions (CDR1-3) that are loops, or turns, connecting 13-strands at one end of the domains ( FIG. 1 : A, C). The variable regions of both the light and heavy chains generally contribute to antigen specificity, although the contribution of the individual chains to specificity is not always equal. Antibody molecules have evolved to bind to a large number of molecules by using six randomized loops (CDRs). However, the size of the antibodies and the complexity of six loops represents a major design hurdle if the end result is to be a relatively small peptide ligand.
Antibody Substructures
[0004] Functional substructures of Abs can be prepared by proteolysis and by recombinant methods. They include the Fab fragment, which comprises the VH-CH1 domains of the heavy chain and the VL-CL1 domains of the light chain joined by a single interchain disulfide bond, and the Fv fragment, which comprises only the VH and VL domains. In some cases, a single VH domain retains significant affinity (Ward et al., 1989). It has also been shown that a certain monomeric κ light chain will specifically bind to its cognate antigen. (L. Masat et al., 1994). Separated light or heavy chains have sometimes been found to retain some antigen-binding activity (Ward et al., 1989). These antibody fragments are not suitable for structural analysis using NMR spectroscopy due to their size, low solubility or low conformational stability.
[0005] Another functional substructure is a single chain Fv (scFv), comprised of the variable regions of the immunoglobulin heavy and light chain, covalently connected by a peptide linker (S-z Hu et al., 1996). These small (M, 25,000) proteins generally retain specificity and affinity for antigen in a single polypeptide and can provide a convenient building block for larger, antigen-specific molecules. Several groups have reported biodistribution studies in xenografted athymic mice using scFv reactive against a variety of tumor antigens, in which specific tumor localization has been observed. However, the short persistence of scFvs in the circulation limits the exposure of tumor cells to the scFvs, placing limits on the level of uptake. As a result, tumor uptake by scFvs in animal studies has generally been only 1-5% ID/g as opposed to intact antibodies that can localize in tumors ad 30-40% ID/g and have reached levels as high as 60-70% ID/g.
[0006] A small protein scaffold called a “minibody” was designed using a part of the Ig VH domain as the template (Pessi et al., 1993). Minibodies with high affinity (dissociation constant (K d )˜10 −7 M) to interleukin-6 were identified by randomizing loops corresponding to CDR1 and CDR2 of VH and then selecting mutants using the phage display method (Martin et al., 1994). These experiments demonstrated that the essence of the Ab function could be transferred to a smaller system. However, the minibody had inherited the limited solubility of the VH domain (Bianchi et al., 1994).
[0007] It has been reported that camels ( Camelus dromedarius ) often lack variable light chain domains when IgG-like material from their serum is analyzed, suggesting that sufficient antibody specificity and affinity can be derived form VH domains (three CDR loops) alone. Davies and Riechmann recently demonstrated that “camelized” VH domains with high affinity (K d ˜10 −7 M) and high specificity can be generated by randomizing only the CDR3. To improve the solubility and suppress nonspecific binding, three mutations were introduced to the framework region (Davies & Riechmann, 1995). It has not been definitively shown, however, that camelization can be used, in general, to improve the solubility and stability of VHs.
[0008] An alternative to the “minibody” is the “diabody.” Diabodies are small bivalent and bispecific antibody fragments, i.e., they have two antigen-binding sites. The fragments comprise a heavy-chain variable domain (V H ) connected to a light-chain variable domain (V L ) on the same polypeptide chain (V H -V L ). Diabodies are similar in size to an Fab fragment. By using a linker that is too short to allow pairing between the two domains on the same chain, the domains are forced to pair with the complementary domains of another chain and create two antigen-binding sites. These dimeric antibody fragments, or “diabodies,” are bivalent and bispecific. P. Holliger et al., PNAS 90:6444-6448 (1993).
[0009] Since the development of the monoclonal antibody technology, a large number of 3D structures of Ab fragments in the complexed and/or free states have been solved by X-ray crystallography (Webster et al., 1994; Wilson & Stanfield, 1994). Analysis of Ab structures has revealed that five out of the six CDRs have limited numbers of peptide backbone conformations, thereby permitting one to predict the backbone conformation of CDRs using the so-called canonical structures (Lesk & Tramontano, 1992; Rees et al., 1994). The analysis also has revealed that the CDR3 of the VH domain (VH-CDR3) usually has the largest contact surface and that its conformation is too diverse for canonical structures to be defined; VH-CDR3 is also known to have a large variation in length (Wu et al., 1993). Therefore, the structures of crucial regions of the Ab-antigen interface still need to be experimentally determined.
[0010] Comparison of crystal structures between the free and complexed states has revealed several types of conformational rearrangements. They include side-chain rearrangements, segmental movements, large rearrangements of VH-CDR3 and changes in the relative position of the VH and VL domains (Wilson & Stanfield, 1993). In the free state, CDRs, in particular those which undergo large conformational changes upon binding, are expected to be flexible. Since X-ray crystallography is not suited for characterizing flexible parts of molecules, structural studies in the solution state have not been possible to provide dynamic pictures of the conformation of antigen-binding sites.
Mimicking the Antibody-Binding Site
[0011] CDR peptides and organic CDR mimetics have been made (Dougall et al., 1994). CDR peptides are short, typically cyclic, peptides which correspond to the amino acid sequences of CDR loops of antibodies. CDR loops are responsible for antibody-antigen interactions. Organic CDR mimetics are peptides corresponding to CDR loops which are attached to a scaffold, e.g., a small organic compound.
[0012] CDR peptides and organic CDR mimetics have been shown to retain some binding affinity (Smyth & von Itzstein, 1994). However, as expected, they are too small and too flexible to maintain full affinity and specificity. Mouse CDRs have been grafted onto the human Ig framework without the loss of affinity (Jones et al., 1986; Riechmann et al., 1988), though this “humanization” does not solve the above-mentioned problems specific to solution studies.
Mimicking Natural Selection Processes of Abs
[0013] In the immune system, specific Abs are selected and amplified from a large library (affinity maturation). The processes can be reproduced in vitro using combinatorial library technologies. The successful display of Ab fragments on the surface of bacteriophage has made it possible to generate and screen a vast number of CDR mutations (McCafferty et al., 1990; Barbas et al., 1991; Winter et al., 1994). An increasing number of Fabs and Fvs (and their derivatives) is produced by this technique, providing a rich source for structural studies. The combinatorial technique can be combined with Ab mimics.
[0014] A number of protein domains that could potentially serve as protein scaffolds have been expressed as fusions with phage capsid proteins. Review in Clackson & Wells, Trends Biotechnol. 12:173-184 (1994). Indeed, several of these protein domains have already been used as scaffolds for displaying random peptide sequences, including bovine pancreatic trypsin inhibitor (Roberts et al., PNAS 89:2429-2433 (1992)), human growth hormone (Lowman et al., Biochemistry 30:10832-10838 (1991)), Venturini et al., Protein Peptide Letters 1:70-75 (1994)), and the IgG binding domain of Streptococcus (O'Neil et al., Techniques in Protein Chemistry V (Crabb, L, ed.) pp. 517-524, Academic Press, San Diego (1994)). These scaffolds have displayed a single randomized loop or region.
[0015] Researchers have used the small 74 amino acid α-amylase inhibitor Tendamistat as a presentation scaffold on the filamentous phage M13 (McConnell and Hoess, 1995). Tendamistat is a β-sheet protein from Streptomyces tendae . It has a number of features that make it an attractive scaffold for peptides, including its small size, stability, and the availability of high resolution NMR and X-ray structural data. Tendamistat's overall topology is similar to that of an immunoglobulin domain, with two β-sheets connected by a series of loops. In contrast to immunoglobulin domains, the β-sheets of Tendamistat are held together with two rather than one disulfide bond, accounting for the considerable stability of the protein. By analogy with the CDR loops found in immunoglobulins, the loops the Tendamistat may serve a similar function and can be easily randomized by in vitro mutagenesis.
[0016] Tendamistat, however, is derived from Streptomyces tendae . Thus, while Tendamistat may be antigenic in humans, its small size may, reduce or inhibit its antigenicity. Also, Tendamistat's stability is uncertain. Further, the stability that is reported for Tendamistat is attributed to the presence of two disulfide bonds. Disulfide bonds, however, are a significant disadvantage to such molecules in that they can be broken under reducing conditions and must be properly formed in order to have a useful protein structure. Further, the size of the loops in Tendamistat are relatively small, thus limiting the size of the inserts that can be accommodated in the scaffold. Moreover, it is well known that forming correct disulfide bonds in newly synthesized peptides is not straightforward. When a protein is expressed in the cytoplasmic space of E. coli , the most common host bacterium for protein overexpression, disulfide bonds are usually not formed, potentially making it difficult to prepare large quantities of engineered molecules.
[0017] Thus, there is an on-going need for small, single-chain artificial antibodies for a variety of therapeutic, diagnostic and catalytic applications.
SUMMARY OF THE INVENTION
[0018] The invention provides a fibronectin type III (Fn3) polypeptide monobody comprising a plurality of Fn3 β-strand domain sequences that are linked to a plurality of loop region sequences. One or more of the monobody loop region sequences of the Fn3 polypeptide vary by deletion, insertion or replacement of at least two amino acids from the corresponding loop region sequences in wild-type Fn3. The β-strand domains of the monobody have at least about 50% total amino acid sequence homology to the corresponding amino acid sequence of wild-type Fn3′ s β-strand domain sequences. Preferably, one or more of the loop regions of the monobody comprise amino acid residues:
[0019] i) from 15 to 16 inclusive in an AB loop;
[0020] ii) from 22 to 30 inclusive in a BC loop;
[0021] iii) from 39 to 45 inclusive in a CD loop;
[0022] iv) from 51 to 55 inclusive in a DE loop;
[0023] v) from 60 to 66 inclusive in an EF loop; and
[0024] vi) from 76 to 87 inclusive in an FG loop.
[0025] The invention also provides a nucleic acid molecule encoding a Fn3 polypeptide monobody of the invention, as well as an expression vector comprising said nucleic acid molecule and a host cell comprising said vector.
[0026] The invention further provides a method of preparing a Fn3 polypeptide monobody. The method comprises providing a DNA sequence encoding a plurality of Fn3 β-strand domain sequences that are linked to a plurality of loop region sequences, wherein at least one loop region of said sequence contains a unique restriction enzyme site. The DNA sequence is cleaved at the unique restriction site. Then a preselected DNA segment is inserted into the restriction site. The preselected DNA segment encodes a peptide capable of binding to a specific binding partner (SBP) or a transition state analog compound (TSAC). The insertion of the preselected DNA segment into the DNA sequence yields a DNA molecule which encodes a polypeptide monobody having an insertion. The DNA molecule is then expressed so as to yield the polypeptide monobody.
[0027] Also provided is a method of preparing a Fn3 polypeptide monobody, which method comprises providing a replicatable DNA sequence encoding a plurality of Fn3 β-strand domain sequences that are linked to a plurality of loop region sequences, wherein the nucleotide sequence of at least one loop region is known. Polymerase chain reaction (PCR) primers are provided or prepared which are sufficiently complementary to the known loop sequence so as to be hybridizable under PCR conditions, wherein at least one of the primers contains a modified nucleic acid sequence to be inserted into the DNA sequence. PCR is performed using the replicatable DNA sequence and the primers. The reaction product of the PCR is then expressed so as to yield a polypeptide monobody.
[0028] The invention further provides a method of preparing a Fn3 polypeptide monobody. The method comprises providing a replicatable DNA sequence encoding a plurality of Fn3 β-strand domain sequences that are linked to a plurality of loop region sequences, wherein the nucleotide sequence of at least one loop region is known. Site-directed mutagenesis of at least one loop region is performed so as to create an insertion mutation. The resultant DNA comprising the insertion mutation is then expressed.
[0029] Further provided is a variegated nucleic acid library encoding Fn3 polypeptide monobodies comprising a plurality of nucleic acid species encoding a plurality of Fn3β-strand domain sequences that are linked to a plurality of loop region sequences, wherein one or more of the monobody loop region sequences vary by deletion, insertion or replacement of at least two amino acids from corresponding loop region sequences in wild-type Fn3, and wherein the β-strand domains of the monobody have at least a 50% total amino acid sequence homology to the corresponding amino acid sequence of β-strand domain sequences of the wild-type Fn3. The invention also provides a peptide display library derived from the variegated nucleic acid library of the invention. Preferably, the peptide of the peptide display library is displayed on the surface of a bacteriophage, e.g., a M13 bacteriophage or a fd bacteriophage, or virus.
[0030] The invention also provides a method of identifying the amino acid sequence of a polypeptide molecule capable of binding to a specific binding partner (SBP) so as to, form a polypeptide:SSP complex, wherein the dissociation constant of the said polypeptide:SBP complex is less than 10 −6 moles/liter. The method comprises the steps of:
a) providing a peptide display library of the invention; b) contacting the peptide display library of (a) with an immobilized or separable SBP; c) separating the peptide:SBP complexes from the free peptides; d) causing the replication of the separated peptides of (c) so as to result in a new peptide display library distinguished from that in (a) by having a lowered diversity and by being enriched in displayed peptides capable of binding the SBP; e) optionally repeating steps (b), (c), and (d) with the new library of (d); and f) determining the nucleic acid sequence of the region encoding the displayed peptide of a species from (d) and hence deducing the peptide sequence capable of binding to the SBP.
[0037] The present invention also provides a method of preparing a variegated nucleic acid library encoding Fn3 polypeptide monobodies having a plurality of nucleic acid species each comprising a plurality of loop regions, wherein the species encode a plurality of Fn3 β-strand domain sequences that are linked to a plurality of loop region sequences, wherein one or more of the loop region sequences vary by deletion, insertion or replacement of at least two amino acids from corresponding loop region sequences in wild-type Fn3, and wherein the β-strand domain sequences of the monobody have at least a 50% total amino acid sequence homology to the corresponding amino acid sequences of β-strand domain sequences of the wild-type Fn3, comprising the steps of
a) preparing an Fn3 polypeptide monobody having a predetermined sequence; b) contacting the polypeptide with a specific binding partner (SBP) so as to form a polypeptide:SSP complex wherein the dissociation constant of the said polypeptide:SBP complex is less than 10 −6 moles/liter; c) determining the binding structure of the polypeptide:SBP complex by nuclear magnetic resonance spectroscopy or X-ray crystallography, and d) preparing the variegated nucleic acid library, wherein the variegation is performed at positions in the nucleic acid sequence which, from the information provided in (c), result in one or more polypeptides with improved binding to the SBP.
[0042] Also provided is a method of identifying the amino acid sequence of a polypeptide molecule capable of catalyzing a chemical reaction with a catalyzed rate constant, k cat , and an uncatalyzed rate constant, k uncat , such that the ratio of k cat /k uncat is greater than 10. The method comprises the steps of:
a) providing a peptide display library of the invention; b) contacting the peptide display library of (a) with an immobilized or separable transition state analog compound (TSAC) representing the approximate molecular transition state of the chemical reaction; c) separating the peptide:TSAC complexes from the free peptides; d) causing the replication of the separated peptides of (c) so as to result in a new peptide display library distinguished from that in (a) by having a lowered diversity and by being enriched in displayed peptides capable of binding the TSAC; e) optionally repeating steps (b), (c), and (d) with the new library of (d); and f) determining the nucleic acid sequence of the region encoding the displayed peptide of a species from (d) and hence deducing the peptide sequence.
[0049] The invention also provides a method of preparing a variegated nucleic acid library encoding Fn3 polypeptide monobodies having a plurality of nucleic acid species each comprising a plurality of loop regions, wherein the species encode a plurality of Fn3 β-strand domain sequences that are linked to a plurality of loop region sequences, wherein one or more of the loop region sequences vary by deletion, insertion or replacement of at least two amino acids from corresponding loop region sequences in wild-type Fn3, and wherein the β-strand domain sequences of the monobody have at least a 50% total amino acid sequence homology to the corresponding amino acid sequences of β-strand domain sequences of the wild-type Fn3, comprising the steps of
a) preparing an Fn3 polypeptide monobody having a predetermined sequence, wherein the polypeptide is capable of catalyzing a chemical reaction with a catalyzed rate constant, k cat , and an uncatalyzed rate constant, k uncat , such that the ratio of k cat /k uncat is greater than 10; b) contacting the polypeptide with an immobilized or separable transition state analog compound (TSAC) representing the approximate molecular transition state of the chemical reaction; c) determining the binding structure of the polypeptide:TSAC complex by nuclear magnetic resonance spectroscopy or X-ray crystallography; and d) preparing the variegated nucleic acid library, wherein the variegation is performed at positions in the nucleic acid sequence which, from the information provided in (c), result in one or more polypeptides with improved binding to or stabilization of the TSAC.
[0054] The invention also provides a kit for the performance of any of the methods of the invention. The invention further provides a composition, e.g., a polypeptide, prepared by the use of the kit, or identified by any of the methods of the invention.
[0055] The following abbreviations have been used in describing amino acids, peptides, or proteins: Ala, or A, Alanine; Arg, or R, Arginine; Asn or N, asparagine; Asp, or D, aspartic acid; Cysor C, cystein; Gln, or Q, glutamine; Glu, or E, glutamic acid; Gly, or G, glycine; H is, or H, histidine; Ile, or I, isoleucine; Leu, or L, leucine; Lys, or K, lysine; Met, or M, methionine; Phe, or F, phenylalanine; Pro, or P, proline; Ser, or S, serine; Thr, or T, threonine; Trp, or W, tryptophan; Tyr, or Y, tyrosine; Val, or V, valine.
[0056] The following abbreviations have been used in describing nucleic acids, DNA, or RNA: A, adenosine; T, thymidine; G, guanosine; C, cytosine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0057] FIG. 1A . β-Strand and loop topology of anti-lysozyme immunoglobulin D1.3. (Bhat et al., 1994). The locations of complementarity determining regions (CDRs, hypervariable regions) are indicated.
[0058] FIG. 1B . β-Strand and loop topology of the 10th type III domain of human fibronectin. (Main et al., 1992) The locations of the integrin-binding Arg-Gly-Asp (RGD) sequence is indicated.
[0059] FIG. 1C . MOLSCRIPT representation of anti-lysozyme immunoglobulin D1.3. (Fraulis, 1991; Bhat et al., 1994) The locations of complementarity determining regions (CDRs, hypervariable regions) are indicated.
[0060] FIG. 1D . MOLSCRIPT representation of the 10th type III domain of human fibronectin. (Kraulis, 1991; Main et al., 1992) The locations of the integrin-binding Arg-Gly-Asp (RGD) sequence is indicated.
[0061] FIG. 2 . Amino acid sequence (SEQ ID NO:110) and restriction sites of the synthetic Fn3 gene. The residue numbering is according to Main et al. (1992). Restriction enzyme sites designed are shown above the amino acid sequence. β-Strands are denoted by underlines. The N-terminal “mg” sequence has been added for a subsequent cloning into an expression vector. The His-tag (Novagen) fusion protein has an additional sequence, MGSSHHHHHHSSGLVPRGSH (SEQ ID NO:114), preceding the Fn3 sequence shown above.
[0062] FIG. 3A . Far UV CD spectra of wild-type Fn3 at 25° C. and 90° C. Fn3 (50 μM) was dissolved in sodium acetate (50 mM, pH 4.6).
[0063] FIG. 3B . Thermal denaturation of Fn3 monitored at 215 nm. Temperature was increased at a rate of 1° C./min.
[0064] FIG. 4A . Cα trace of the crystal structure of the complex of lysozyme (HEL) and the Fv fragment of the anti-hen egg-white lysozyme (anti-HEL) antibody D1.3 (Bhat et al., 1994). Side chains of the residues 99-102 of VH CDR3, which make contact with HEL, are also shown.
[0065] FIG. 4B . Contact surface area for each residue of the D1.3 VH-HEL and VH-VL interactions plotted vs. residue number of D1.3 VH. Surface area and secondary structure were determined using the program DSSP (Kabsh and Sander, 1983).
[0066] FIG. 4C . Schematic drawings of the β-sheet structure of the F strand-loop-G strand moieties of D1.3 VH. The boxes denote residues in β-strands and ovals those not in strands. The shaded boxes indicate residues of which side chains are significantly buried. The broken lines indicate hydrogen bonds.
[0067] FIG. 4D . Schematic drawings of the n-sheet structure of the F strand-loop-G strand moieties of Fn3. The boxes denote residues in β-strands and ovals those not in strands. The shaded boxes indicate residues of which side chains are significantly buried. The broken lines indicate hydrogen bonds.
[0068] FIG. 5 . Designed Fn3 gene showing DNA and amino acid sequences (SEQ ID NO:111 and SEQ ID NO:112). The amino acid numbering is according to Main et al. (1992). The two loops that were randomized in combinatorial libraries are enclosed in boxes.
[0069] FIG. 6 . Map of plasmid pAS45. Plasmid pAS45 is the expression vector of His•tag-Fn3.
[0070] FIG. 7 . Map of plasmid pAS25. Plasmid pAS25 is the expression vector of Fn3.
[0071] FIG. 8 . Map of plasmid pAS38. pAS38 is a phagmid vector for the surface display of Fn3.
[0072] FIG. 9 . (Ubiquitin-1) Characterization of ligand-specific binding of enriched clones using phage enzyme-linked immunosolvent assay (ELISA). Microliter plate wells were coated with ubiquitin (1 μg/well; “Ligand (+)) and then blocked with BSA. Phage solution in TBS containing approximately 10 10 colony forming units (cfu) was added to a well and washed with TBS. Bound phages were detected with anti-phage antibody-POD conjugate (Pharmacia) with Turbo-TMB (Pierce) as a substrate. Absorbance was measured using a Molecular Devices SPECTRAMAX 250 microplate spectrophotometer. For a control, wells without the immobilized ligand were used. 2-1 and 2-2 denote enriched clones from Library 2 eluted with free ligand and acid, respectively. 4-1 and 4-2 denote enriched clones from Library 4 eluted with free ligand and acid, respectively.
[0073] FIG. 10 . (Ubiquitin-2) Competition phage ELISA of enriched clones. Phage solutions containing approximately 10 10 cfu were first incubated with free ubiquitin at 4° C. for 1 hour prior to the binding to a ligand-coated well. The wells were washed and phages detected as described above.
[0074] FIG. 11 . Competition phage ELISA of ubiquitin-binding monobody 411. Experimental conditions are the same as described above for ubiquitin. The ELISA was performed in the presence of free ubiquitin in the binding solution. The experiments were performed with four different preparations of the same clone.
[0075] FIG. 12 . (Fluorescein-1) Phage ELISA of four clones, pLB25.1 (containing SEQ ID NO:115), pLB25.4 (containing SEQ ID NO:116), pLB24.1 (containing SEQ ID NO:117) and pLB24.3 (containing SEQ ID NO:118). Experimental conditions are the same as ubiquitin-1 above.
[0076] FIG. 13 . (Fluorescein-2) Competition ELISA of the four clones. Experimental conditions are the same as ubiquitin-2 above.
[0077] FIG. 14 . 1 H, 15 N—HSQC spectrum of a fluorescence-binding monobody LB25.5. Approximately 20 μm protein was dissolved in 10 mm sodium acetate buffer (pH 5.0) containing 100 mM sodium chloride. The spectrum was collected at 30° C. on a Varian Unity NOVA 600 NMR spectrometer.
[0078] FIG. 15A . Characterization of the binding reaction of Ubi4-Fn3 to the target, ubiquitin. Phage ELISA analysis of binding of Ubi4-Fn3 to ubiquitin. The binding of Ubi4-phages to ubiquitin-coated wells was measured. The control experiment was performed with wells containing no ubiquitin.
[0079] FIG. 15B . Competition phage ELISA of Ubi4-Fn3. Ubi4-Fn3 phages were preincubated with soluble ubiquitin at an indicated concentration, followed by the phage ELISA detection in ubiquitin-coated wells.
[0080] FIG. 15C . Competition phage ELISA testing the specificity of the Ubi4 clone. The Ubi4 phages were preincubated with 250 μg/ml of soluble proteins, followed by phage ELISA as in (b).
[0081] FIG. 15D . ELISA using free proteins.
[0082] FIG. 16 . Equilibrium unfolding curves for Ubi4-Fn3 (closed symbols) and wild-type Fn3 (open symbols). Squares indicate data measured in TBS (Tris HCl buffer (50 mM, pH 7.5) containing NaCl (150 mM)). Circles indicate data measured in Gly HCl buffer (20 mM, pH 3.3) containing NaCl (300 mM). The curves show the best fit of the transition curve based on the two-state model. Parameters characterizing the transitions are listed in Table 7.
[0083] FIG. 17 . (a) 1 H, 15 N-HSQC spectrum of [ 15 N]-Ubi4-K Fn3. (b). Difference (δ wild-type -δ Ubi4 ) of 1 H (b) and 15 N(c) chemical shifts plotted versus residue number. Values for residues 82-84 (shown as filled circles) where Ubi4-K deletions are set to zero. Open circles indicate residues that are mutated in the Ubi4-K protein. The locations of β-strands are indicated with arrows.
DETAILED DESCRIPTION OF THE INVENTION
[0084] For the past decade the immune system has been exploited as a rich source of de novo catalysts. Catalytic antibodies have been shown to have chemoselectivity, enantioselectivity, large rate accelerations, and even an ability to reroute chemical reactions. In most cases the antibodies have been elicited to transition state analog (TSA) haptens. These TSA haptens are stable, low-molecular weight compounds designed to mimic the structures of the energetically unstable transition state species that briefly (approximate half-life 10 −13 s) appear along reaction pathways between reactants and products. Anti-TSA antibodies, like natural enzymes, are thought to selectively bind and stabilize transition state, thereby easing the passage of reactants to products. Thus, upon binding, the antibody lowers the energy of the actual transition state and increases the rate of the reaction. These catalysts can be programmed to bind to geometrical and electrostatic features of the transition state so that the reaction route can be controlled by neutralizing unfavorable charges, overcoming entropic barriers, and dictating stereoelectronic features of the reaction. By this means even reactions that are otherwise highly disfavored have been catalyzed (Janda et al. 1997). Further, in many instances catalysts have been made for reactions for which there are no known natural or manmade enzymes.
[0085] The success of any combinatorial chemical system in obtaining a particular function depends on the size of the library and the ability to access its members. Most often the antibodies that are made in an animal against a hapten that mimics the transition state of a reaction are first screened for binding to the hapten and then screened again for catalytic activity. An improved method allows for the direct selection for catalysis from antibody libraries in phage, thereby linking chemistry and replication.
[0086] A library of antibody fragments can be created on the surface of filamentous phage viruses by adding randomized antibody genes to the gene that encodes the phage's coat protein. Each phage then expresses and displays multiple copies of a single antibody fragment on its surface. Because each phage possesses both the surface-displayed antibody fragment and the DNA that encodes that fragment, and antibody fragment that binds to a target can be identified by amplifying the associated DNA.
[0087] Immunochemists use as antigens materials that have as little chemical reactivity as possible. It is almost always the case that one wishes the ultimate antibody to interact with native structures. In reactive immunization the concept is just the opposite. One immunizes with compounds that are highly reactive so that upon binding to the antibody molecule during the induction process, a chemical reaction ensues. Later this same chemical reaction becomes part of the mechanism of the catalytic event. In a certain sense one is immunizing with a chemical reaction rather than a substance per se. Reactive immunogens can be considered as analogous to the mechanism-based inhibitors that enzymologists use except that they are used in the inverse way in that, instead of inhibiting a mechanism, they induce a mechanism.
[0088] Man-made catalytic antibodies have considerable commercial potential in many different applications. Catalytic antibody-based products have been used successfully in prototype experiments in therapeutic applications, such as prodrug activation and cocaine inactivation, and in nontherapeutic applications, such as biosensors and organic synthesis.
[0089] Catalytic antibodies are theoretically more attractive than noncatalytic antibodies as therapeutic agents because, being catalytic, they may be used in lower doses, and also because their effects are unusually irreversible (for example, peptide bond cleavage rather than binding). In therapy, purified catalytic antibodies could be directly administered to a patient, or alternatively the patient's own catalytic antibody response could be elicited by immunization with an appropriate hapten. Catalytic antibodies also could be used as clinical diagnostic tools or as regioselective or stereoselective catalysts in the synthesis of fine chemicals.
[0000] I. Mutation of Fn3 loops and grafting of Ab loops onto Fn3
[0090] An ideal scaffold for CDR grafting is highly soluble and stable. It is small enough for structural analysis, yet large enough to accommodate multiple CDRs so as to achieve tight binding and/or high specificity.
[0091] A novel strategy to generate an artificial Ab system on the framework of an existing non-Ab protein was developed. An advantage of this approach over the minimisation of an Ab scaffold is that one can avoid inheriting the undesired properties of Abs. Fibronectin type DT domain (Fn3) was used as the scaffold. Fibronectin is a large protein which plays essential roles in the formation of extracellular matrix and cell-cell interactions; it consists of many repeats of three types (I, II and III) of small domains (Baron et al., 1991). Fn3 itself is the paradigm of a large subfamily (Fn3 family or s-type Ig family) of the immunoglobulin superfamily (IgSF). The Fn3 family includes cell adhesion molecules, cell surface hormone and cytokine receptors, chaperonins, and carbohydrate-binding domains (for reviews, see Bork & Doolittle, 1992; Jones, 1993; Bork et al., 1994; Campbell & Spitzfaden, 1994; Harpez & Chothia, 1994).
[0092] Recently, crystallographic studies revealed that the structure of the DNA binding domains of the transcription factor NF-kB is also closely related to the Fn3 fold (Ghosh et al., 1995; Müller et al., 1995). These proteins are all involved in specific molecular recognition, and in most cases ligand-binding sites are formed by surface loops, suggesting that the Fn3 scaffold is an excellent framework for building specific binding proteins. The 3D structure of Fn3 has been determined by NMR (Main et al., 1992) and by X-ray crystallography (Leahy et al., 1992; Dickinson et al., 1994). The structure is best described as a β-sandwich similar to that of Ab VH domain except that Fn3 has seven β-strands instead of nine ( FIG. 1 ). There are three loops on each end of Fn3; the positions of the BC, DE and FG loops approximately correspond to those of CDR1, 2 and 3 of the VH domain, respectively ( FIG. 1 C, D).
[0093] Fn3 is small (˜95 residues), monomeric, soluble and stable. It is one of few members of IgSF that do not have disulfide bonds; VH has an interstrand disulfide bond ( FIG. 1A ) and has marginal stability under reducing conditions. Fn3 has been expressed in E. coli (Aukhil et al., 1993). In addition, 17 Fn3 domains are present just in human fibronectin, providing important information on conserved residues which are often important for the stability and folding (for sequence alignment, see Main et al., 1992 and Dickinson et al., 1994). From sequence analysis, large variations are seen in the BC and FG loops, suggesting that the loops are not crucial to stability. NMR studies have revealed that the FG loop is highly flexible; the flexibility has been implicated for the specific binding of the 10th Fn3 to α 5 β 1 integrin through the Arg-Gly-Asp (RGD) (SEQ ID NO:113) motif. In the crystal structure of human growth hormone-receptor complex (de Vos et al., 1992), the second Fn3 domain of the receptor interacts with hormone via the FG and BC loops, suggesting it is feasible to build a binding site using the two loops.
[0094] The tenth type III module of fibronectin has a fold similar to that of immunoglobulin domains, with seven β strands forming two antiparallel β sheets, which pack against each other (Main et al., 1992). The structure of the type II module consists of seven β strands, which form a sandwich of two antiparallel β sheets, one containing three strands (ABE) and the other four strands (C′CFG) (Williams et al., 1988). The triple-stranded β sheet consists of residues Glu-9-Thr-14 (A), Ser-17-Asp-23 (B), and Thr-56-Ser-60 (E). The majority of the conserved residues contribute to the hydrophobic core, with the invariant hydrophobic residues Trp-22 and Try-68 lying toward the N-terminal and C-terminal ends of the core, respectively. The β strands are much less flexible and appear to provide a rigid framework upon which functional, flexible loops are built. The topology is similar to that of immunoglobulin C domains.
Gene Construction and Mutagenesis
[0095] A synthetic gene for tenth Fn3 of human fibronectin ( FIG. 2 ) was designed which includes convenient restriction sites for ease of mutagenesis and uses specific codons for high-level protein expression (Gribskov et al., 1984).
[0096] The gene was assembled as follows: (1) the gene sequence was divided into five parts with boundaries at designed restriction sites ( FIG. 2 ); (2) for each part, a pair of oligonucleotides that code opposite strands and have complementary overlaps of ˜15 bases was synthesized; (3) the two oligonucleotides were annealed and single strand regions were filled in using the Klenow fragment of DNA polymerase; (4) the double-stranded oligonucleotide was cloned into the pET3a vector (Novagen) using restriction enzyme sites at the termini of the fragment and its sequence was confirmed by an Applied Biosystems DNA sequencer using the dideoxy termination protocol provided by the manufacturer, (5) steps 2-4 were repeated to obtain the whole gene (plasmid pAS25) ( FIG. 7 ).
[0097] Although the present method takes more time to assemble a gene than the one-step polymerase chain reaction (PCR) method (Sandhu et al., 1992), no mutations occurred in the gene. Mutations would likely have been introduced by the low fidelity replication by Taq polymerase and would have required time-consuming gene editing. The gene was also cloned into the pET15b (Novagen) vector (pEW1). Both vectors expressed the Fn3 gene under the control of bacteriophage T7 promoter (Studler et at 1990); pAS25 expressed the 96-residue Fn3 protein only, while pEW1 expressed Fn3 as a fusion protein with poly-histidine peptide (His•tag). Recombinant DNA manipulations were performed according to Molecular Cloning (Sambrook et al., 1989), unless otherwise stated.
[0098] Mutations were introduced to the Fn3 gene using either cassette mutagenesis or oligonucleotide site-directed mutagenesis techniques (Deng & Nickolof 1992). Cassette mutagenesis was performed using the same protocol for gene construction described above; double-stranded DNA fragment coding a new sequence was cloned into an expression vector (pAS25 and/or pEW1). Many mutations can be made by combining a newly synthesized strand (coding mutations) and an oligonucleotide used for the gene synthesis. The resulting genes were sequenced to confirm that the designed mutations and no other mutations were introduced by mutagenesis reactions.
[0000] Design and Synthesis of Fn3 Mutants with Antibody CDRs
[0099] Two candidate loops (FG and BC) were identified for grafting. Antibodies with known crystal structures were examined in order to identify candidates for the sources of loops to be grafted onto Fn3. Anti-hen egg lysozyme (HEL) antibody D1.3 (Bhat et al., 1994) was chosen as the source of a CDR loop. The reasons for this choice were: (1) high resolution crystal structures of the free and complexed states are available ( FIG. 4 A; Bhat et al., 1994), (2) thermodynamics data for the binding reaction are available (Tello et al., 1993), (3) D1.3 has been used as a paradigm for Ab structural analysis and Ab engineering (Verhoeyen et al., 1988; McCafferty et al., 1990) (4) site-directed mutagenesis experiments have shown that CDR3 of the heavy chain (VH-CDR3) makes a larger contribution to the affinity than the other CDRs (Hawkins et al., 1993), and (5) a binding assay can be easily performed. The objective for this trial was to graft VH-CDR3 of D1.3 onto the Fn3 scaffold without significant loss of stability.
[0100] An analysis of the D1.3 structure ( FIG. 4 ) revealed that only residues 99-102 (“RDYR”) make direct contact with hen egg-white lysozyme (HEL) ( FIG. 4 B), although VH-CDR3 is defined as longer (Bhat et al., 1994). It should be noted that the C-terminal half of VH-CDR3 (residues 101-104) made significant contact with the VL domain ( FIG. 4 B). It has also become clear that D1.3 VH-CDR3 ( FIG. 4 C) has a shorter turn between the strands F and G than the FG loop of Fn3 ( FIG. 4 D). Therefore, mutant sequences were designed by using the RDYR (99-102) of D1.3 as the core and made different boundaries and loop lengths (Table 1). Shorter loops may mimic the D1.3 CDR3 conformation better, thereby yielding higher affinity, but they may also significantly reduce stability by removing wild-type interactions of Fn3.
[0000]
TABLE 1
Amino acid sequences of D 1.3 VH CDR3, VH8 CDR3 and Fn3 FG
loop and list of planned mutants.
96 100 105
• • •
D1.3
A R E R D Y R L D Y W G Q G
(SEQ ID NO: 1)
VH8
A R G A V V S Y Y A M D Y W G Q G
(SEQ ID NO: 2)
75 80 85
• • •
Fn3
Y A V T G R G D S P A S S K P I
(SEQ ID NO: 3)
Mutant
Sequence
D1.3-1
Y A E R D Y R L D Y - - - - P I
(SEQ ID NO: 4)
D1.3-2
Y A V R D Y R L D Y - - - - P I
(SEQ ID NO: 5)
D1.3-3
Y A V R D Y R L D Y A S S K P I
(SEQ ID NO: 6)
D1.3-4
Y A V R D Y R L D Y - - - K P I
(SEQ ID NO: 7)
D1.3-5
Y A V R D Y R - - - - - S K P I
(SEQ ID NO: 8)
D1.3-6
Y A V T R D Y R L - - S S K P I
(SEQ ID NO: 9)
D1.3-7
Y A V T E R D Y R L - S S K P I
(SEQ ID NO: 10)
VH8-1
Y A V A V V S Y Y A M D Y - P I
(SEQ ID NO: 11)
VH8-2
Y A V T A V V S Y Y A S S K P I
(SEQ ID NO: 12)
Underlines indicate residues in β-strands. Bold characters indicate replaced residues.
[0101] In addition, an anti-HEL single VH domain termed VH8 (Ward et al., 1989) was chosen as a template. VH8 was selected by library screening and, in spite of the lack of the VL domain, VH8 has an affinity for HEL of 27 nM, probably due to its longer VH-CDR3 (Table 1). Therefore, its VH-CDR3 was grafted onto Fn3. Longer loops may be advantageous on the Fn3 framework because they may provide higher affinity and also are close to the loop length of wild-type Fn3. The 3D structure of VH-18 was not known and thus the VH8 CDR3 sequence was aligned with that of D1.3 VH-CDR3; two loops were designed (Table 1).
Mutant Construction and Production
[0102] Site-directed mutagenesis experiments were performed to obtain designed sequences. Two mutant Fn3s, D1.3-1 and D1.3-4 (Table 1) were obtained and both were expressed as soluble His-tag fusion proteins. D1.34 was purified and the His.tag portion was removed by thrombin cleavage. D1.3-4 is soluble up to at least 1 mM at pH 7.2. No aggregation of the protein has been observed during sample preparation and NMR data acquisition.
Protein Expression and Purification
[0103] E. coli BL21 (DE3) (Novagen) were transformed with an expression vector (pAS25, pEW1 and their derivatives) containing a gene for the wild-type or a mutant Cells were grown in M9 minimal medium and M9 medium supplemented with Bactotrypton (Difco) containing ampicillin (200 μg/ml). For isotopic labeling, 15 N NH 4 Cl and/or 13 C glucose replaced unlabeled components. 500 mL medium in a 2 liter baffle flask were inoculated with 10 ml of overnight culture and agitated at 37° C. Isopropylthio-β-galactoside (IPTG) was added at a final concentration of 1 mM to initiate protein expression when OD (600 nm) reaches one. The ceils were harvested by centrifugation 3 hours after the addition of IPTG and kept frozen at −70° C. until used.
[0104] Fn3 without His•tag was purified as follows. Cells were suspended in 5 ml/(g cell) of Tris (50 mM, pH 7.6) containing ethylenediaminetetraacetic acid (EDTA; 1 mM) and phenylmethylsulfonyl fluoride (1 mM). HEL was added to a final concentration of 0.5 mg/mL. After incubating the solution for 30 minutes at 37° C., it was sonicated three times for 30 seconds on ice. Cell debris was removed by centrifugation. Ammonium sulfate was added to the solution and precipitate recovered by centrifugation. The pellet was dissolved in 5-10 ml sodium acetate (50 mM, pH 4.6) and insoluble material was removed by centrifugation. The solution was applied to a SEPHACRYL S100HR column (Pharmacia) equilibrated in the sodium acetate buffer. Fractions containing Fn3 then was applied to a RESOURCES® column (Pharmacia) equilibrated in sodium acetate (50 mM, pH 4.6) and eluted with a linear gradient of sodium chloride (0-0.5 M). The protocol can be adjusted to purify mutant proteins with different surface charge properties.
[0105] Fn3 with His•tag was purified as follows. The soluble fraction was prepared as described above, except that sodium phosphate buffer (50 mM, pH 7.6) containing sodium chloride (100 mM) replaced the Tris buffer. The solution was applied to a HI-TRAP chelating column (Pharmacia) preloaded with nickel and equilibrated in the phosphate buffer. After washing the column with the buffer, His•tag-Fn3 was eluted in the phosphate buffer containing 50 mM EDTA. Fractions containing His•tag-Fn3 were pooled and applied to a SEPHACRYL S100-HR column, yielding highly pure protein. The His•tag portion was cleaved off by treating the fusion protein with thrombin using the protocol supplied by Novagen. Fn3 was separated from the His•tag peptide and thrombin by a RESOURCES® column using the protocol above.
[0106] The wild-type and two mutant proteins so far examined are expressed as soluble proteins. In the case that a mutant is expressed as inclusion bodies (insoluble aggregate), it is first examined if it can be expressed as a soluble protein at lower temperature (e.g., 25-30° C.). If this is not possible, the inclusion bodies are collected by low-speed centrifugation following cell lysis as described above. The pellet is washed with buffer, sonicated and centrifuged. The inclusion bodies are solubilized in phosphate buffer (50 mM, pH 7.6) containing guanidinium chloride (GdnCl, 6 M) and will be loaded on a HI-TRAP chelating column The protein is eluted with the buffer containing GdnCl and 50 mM EDTA.
Conformation of Mutant Fn3, D1.34
[0107] The 1 H NMR spectra of His•tag D1.3-4 fusion protein closely resembled that of the wild-type, suggesting the mutant is folded in a similar conformation to that of the wild-type. The spectrum of D1.3-4 after the removal of the His•tag peptide showed a large spectral dispersion. A large dispersion of amide protons (7-9.5 ppm) and a large number of downfield (5.0-6.5 ppm) C α protons are characteristic of a β-sheet protein (Wüthrich, 1986).
[0108] The 2D NOESY spectrum of D1.34 provided further evidence for a preserved conformation. The region in the spectrum showed interactions between upfield methyl protons (<0.5 ppm) and methyl-methylene protons. The Va172 γ methyl resonances were well separated in the wild-type spectrum (−0.07 and 0.37 ppm; (Baron et al., 1992)). Resonances corresponding to the two methyl protons are present in the 131.3-4 spectrum (−0.07 and 0.44 ppm). The cross peak between these two resonances and other conserved cross peaks indicate that the two resonances in the D1.3-4 spectrum are highly likely those of Val 72 and that other methyl protons are in nearly identical environment to that of wild-type Fn3. Minor differences between the two spectra are presumably due to small structural perturbation due to the mutations. Val 72 is on the F strand, where it forms a part of the central hydrophobic core of Fn3 (Main et al., 1992). It is only four residues away from the mutated residues of the FG loop (Table 1). The results are remarkable because, despite there being 7 mutations and 3 deletions in the loop (more than 10% of total residues; FIG. 12 , Table 2), D1.3-4 retains a 3D structure virtually identical to that of the wild-type (except for the mutated loop). Therefore, the results provide strong support that the FG loop is not significantly contributing to the folding and stability of the Fn3 molecule and thus that the FG loop can be mutated extensively.
[0000] TABLE 2 Sequences of oligonucleotides Name Sequence FN1F CGGGATCC CATATG CAGGTTTCTGATGTTCCGCGTGACCTGGAAGTTGTTGCTGCGACC (SEQ ID NO: 13) FN1R TAA CTGCAG GAGCATCCCAGCTGATCAGCAGGCTAGTCGGGGTCGCAGCAACAAC (SEQ ID NO: 14) FN2F CTC CTGCAG TTACCGTGCGTTATTACCGTATCACGTACGGTGAAACCGGTG (SEQ ID NO: 15) FN2R GT GAATTC CTGAACCGGGGAGTTACCACCGGTTTCACCG (SEQ ID NO: 16) FN3F AG GAATTC ACTGTACCTGGTTCCAAGTCTACTGCTACCATCAGCGG (SEQ ID NO: 17) FN3R GTATA GTCGAC ACCCGGTTTCAGGCCGCTGATGGTAGC (SEQ ID NO: 18) FN4F CGGGT GTCGAC TATACCATCACTGTATACGCT (SEQ ID NO: 19) FN4R CGGGATCC GAGCTC GCTGGGCTGTCACCACGGCCAGTAACAGCGTATACAGTGAT (SEQ ID NO: 20) FN5F CAGC GAGCTC CAAGCCAATCTCGATTAACTACCGT (SEQ ID NO: 21) FN5R CG GGATCC TCGAGTTACTAGGTACGGTAGTTAATCGA (SEQ ID NO: 22) FN5R′ CG GGATCC ACGCGTGCCACCGGTACGGTAGTTAATCGA (SEQ ID NO: 23) gene3F CG GGATCC ACGCGTCCATTCGTTTGTGAATATCAAGGCCAATCG (SEQ ID NO: 24) gene3R CCGG AAGCTT TAAGACTCCTTATTACGCAGTATGTTAGC (SEQ ID NO: 25) 38TAABg1II CTGTTACTGGCCGTGAGATCTAACCAGCGAGCTCCA (SEQ ID NO: 26) BC3 GATCAGCTGGGATGCTCCTNNKNNKNNKNNKNNKTATTACCGTATCACGTA (SEQ ID NO: 27) FG2 TGTATACGCTGTTACTGGCNNKNNKNNKNNKNNKNNKNNKTCCAAGCCAATCTCGAT (SEQ ID NO: 28) FG3 CTGTATACGCTGTTACTGGCNNKNNKNNKNNKCCAGCGAGCTCCAAG (SEQ ID NO: 29) FG4 CATCACTGTATACGCTGTTACTNNKNNKNNKNNKNNKTCCAAGCCAATCTC (SEQ ID NO: 30)
Restriction enzyme sites are underlined. N and K denote an equimolar mixture of A, T. G and C and that of G and T, respectively.
Structure and Stability Measurements
[0109] Structures of Abs were analyzed using quantitative methods (e.g., DS SP (Kabsch & Sander, 1983) and PDBFIT (D. McRee, The Scripps Research Institute)) as well as computer graphics (e.g., QUANTA (Molecular Simulations) and WHAT IF (G. Vriend, European Molecular Biology Laboratory)) to superimpose the strand-loop-strand structures of Abs and Fn3.
[0110] The stability of FnAbs was determined by measuring temperature- and chemical denaturant-induced unfolding reactions (Pace et al., 1989). The temperature-induced unfolding reaction was measured using a circular dichroism (CD) polarimeter. Ellipticity at 222 and 215 nm was recorded as the sample temperature was slowly raised. Sample concentrations between 10 and 50 μM were used. After the unfolding baseline was established, the temperature was lowered to examine the reversibility of the unfolding reaction. Free energy of unfolding was determined by fitting data to the equation for the two-state transition (Becktel & Schellman, 1987; Pace et al., 1989). Nonlinear least-squares fitting was performed using the program IGOR (WaveMetrics) on a Macintosh computer.
[0111] The structure and stability of two selected mutant Fn3s were studied; the first mutant was D1.34 (Table 2) and the second was a mutant called AS40 which contains four mutations in the BC loop (A 26 V 27 T 28 V 29 )→TQRQ). AS40 was randomly chosen from the BC loop library described above. Both mutants were expressed as soluble proteins in E. coli and were concentrated at least to 1 mM, permitting NMR studies.
[0112] The mid-point of the thermal denaturation for both mutants was approximately 69° C., as compared to approximately 79° C. for the wild-type protein. The results indicated that the extensive mutations at the two surface loops did not drastically decrease the stability of Fn3, and thus demonstrated the feasibility of introducing a large number of mutations in both loops.
[0113] Stability was also determined by guanidinium chloride (GdnCl)- and urea-induced unfolding reactions. Preliminary unfolding curves were recorded using a fluorometer equipped with a motor-driven syringe; GdnCl or urea were added continuously to the protein solution in the cuvette. Based on the preliminary unfolding curves, separate samples containing varying concentration of a denaturant were prepared and fluorescence (excitation at 290 nm, emission at 300-400 nm) or CD (ellipticity at 222 and 215 nm) were measured after the samples were equilibrated at the measurement temperature for at least one hour. The curve was fitted by the least-squares method to the equation for the two-state model (Santoro & Bolen, 1988; Koide et al., 1993). The change in protein concentration was compensated if required.
[0114] Once the reversibility of the thermal unfolding reaction is established, the unfolding reaction is measured by a Microcal MC-2 differential scanning calorimeter (DSC). The cell (˜1.3 ml) will be filled with FnAb solution (0.1-1 mM) and ΔCp (=ΔH/ΔT) will be recorded as the temperature is slowly raised T m (the midpoint of unfolding), ΔH of unfolding and ΔG of unfolding is determined by fitting the transition curve (Privalov & Potekhin, 1986) with the ORIGIN software provided by Microcal.
Thermal Unfolding
[0115] A temperature-induced unfolding experiment on Fn3 was performed using circular dichroism (CD) spectroscopy to monitor changes in secondary structure. The CD spectrum of the native Fn3 shows a weak signal near 222 nm ( FIG. 3A ), consistent with the predominantly β-structure of Fn3 (Perczel et al., 1992). A cooperative unfolding transition is observed at 80-90° C., clearly indicating high stability of Fn3 ( FIG. 3B ). The free energy of unfolding could not be determined due to the lack of a post-transition baseline. The result is consistent with the high stability of the first Fn3 domain of human fibronectin (Litvinovich et al., 1992), thus indicating that Fn3 domains are in general highly stable.
Binding Assays
[0116] Binding reaction of FnAbs were characterized quantitatively using an isothermal titration calorimeter (ITC) and fluorescence spectroscopy.
[0117] The enthalpy change (ΔH) of binding were measured using a Microcal OMEGA ITC (Wiseman et al., 1989). The sample cell (−1.3 ml) was filled with FnAbs solution (≦100 μM, changed according to K d ), and the reference cell filled with distilled water; the system was equilibrated at a given temperature until a stable baseline is obtained; 5-20 μl of ligand solution (≦2 mM) was injected by a motordriven syringe within a short duration (20 sec) followed by an equilibration delay (4 minutes); the injection was repeated and heat generation/absorption for each injection was measured. From the change in the observed heat change as a function of ligand concentration, Δ and K d was determined (Wiseman et al., 1989). ΔG and ΔS of the binding reaction was deduced from the two directly measured parameters. Deviation from the theoretical curve was examined to assess nonspecific (multiplesite) binding. Experiments were also performed by placing a ligand in the cell and titrating with an FnAb. It should be emphasized that only ITC gives direct measurement of ΔH, thereby making it possible to evaluate enthalpic and entropic contributions to the binding energy. ITC was successfully used to monitor the binding reaction of the D1.3 Ab (Tello et al., 1993; Bhat et al., 1994).
[0118] Intrinsic fluorescence is monitored to measure binding reactions with K d in the sub-μM range where the determination of K d by ITC is difficult Trp fluorescence (excitation at ˜290 nm, emission at 300-350 nm) and Tyr fluorescence (excitation at ˜260 nm, emission at ˜303 nm) is monitored as the Fn3-mutant solution (≦10 μM) is titrated with ligand solution (≦100 μM). K d of the reaction is determined by the nonlinear least-squares fitting of the bimolecular binding equation. Presence of secondary binding sites is examined using Scatchard analysis. In all binding assays, control experiments are performed busing wild-type Fn3 (or unrelated FnAbs) in place of FnAbs of interest.
[0000] II. Production of Fn3 Mutants with High Affinity and Specificity FnAbs
[0119] Library screening was carried out in order to select FnAbs which bind to specific ligands. This is complementary to the modeling approach described above. The advantage of combinatorial screening is that one can easily produce and screen a large number of variants (≧10 8 ), which is not feasible with specific mutagenesis (“rational design”) approaches. The phage display technique (Smith, 1985; O'Neil & Hoess, 1995) was used to effect the screening processes. Fn3 was fused to a phage coat protein (pHI) and displayed on the surface of filamentous phages. These phages harbor a single-stranded DNA genome that contains the gene coding the Fn3 fusion protein. The amino acid sequence of defined regions of Fn3 were randomized using a degenerate nucleotide sequence, thereby constructing a library. Phages displaying Fn3 mutants with desired binding capabilities were selected in vitro, recovered and amplified. The amino acid sequence of a selected clone can be identified readily by sequencing the Fn3 gene of the selected phage. The protocols of Smith (Smith & Scott, 1993) were followed with minor modifications.
[0120] The objective was to produce FnAbs which have high affinity to small protein ligands. HEL and the B1 domain of staphylococcal protein G (hereafter referred to as protein G) were used as ligands. Protein G is small (56 amino acids) and highly stable (Minor & Kim, 1994; Smith et al., 1994). Its structure was determined by NMR spectroscopy (Gronenbom et al., 1991) to be a helix packed against a four-strand β-sheet. The resulting FnAb-protein G complexes (˜150 residues) is one of the smallest protein-protein complexes produced to date, well within the range of direct NMR methods. The small size, the high stability and solubility of both components and the ability to label each with stable isotopes ( 13 C and 15 N; see below for protein G) make the complexes an ideal model system for NMR studies on protein-protein interactions.
[0121] The successful loop replacement of Fn3 (the mutant D1.34) demonstrate that at least ten residues can be mutated without the loss of the global fold. Based on this, a library was first constructed in which only residues in the FG loop are randomized.
[0122] After results of loop replacement experiments on the BC loop were obtained, mutation sites were extended that include the BC loop and other sites.
Construction of Fn3 Phage Display System
[0123] An M13 phage-based expression vector pASM1 has been constructed as follows: an oligonucleotide coding the signal peptide of OmpT was cloned at the 5′ end of the Fn3 gene; a gene fragment coding the C-terminal domain of M13 pIII was prepared from the wild-type gene III gene of M13 mp 18 using PCR (Corey et al., 1993) and the fragment was inserted at the 3′ end of the OmpT-Fn3 gene; a spacer sequence has been inserted between Fn3 and pIII. The resultant fragment (OmpTFn3-pIII) was cloned in the multiple cloning site of M13 mp18, where the fusion gene is under the control of the lac promoter. This system will produce the Fn3-pIII fusion protein as well as the wild-type pIII-protein. The co-expression of wild-type pIII is expected to reduce the number of fusion pIII protein, thereby increasing the phage infectivity (Corey et al., 1993) (five copies of pIII are present on a phage particle). In addition, a smaller number of fusion pIII protein may be advantageous in selecting tight binding proteins, because the chelating effect due to multiple binding sites should be smaller than that with all five copies of fusion pIII (Bass et al., 1990). This system has successfully displayed the serine protease trypsin (Corey et al., 1993). Phages were produced and purified using E. coli K91kan (Smith & Scott, 1993) according to a standard method (Sambrook et al., 1989) except that phage particles were purified by a second polyethylene glycol precipitation and acid precipitation.
[0124] Successful display of Fn3 on fusion phages has been confirmed by ELISA using an Ab against fibronectin (Sigma), clearly indicating that it is feasible to construct libraries using this system.
[0125] An alternative system using the fUSE5 (Parmley & Smith, 1988) may also be used. The Fn3 gene is inserted to fUSE5 using the SfiI restriction sites introduced at the 5′- and 3′-ends of the Fn3 gene PCR. This system displays only the fusion pIII protein (up to five copies) on the surface of a phage. Phages are produced and purified as described-(Smith & Scott, 1993). This system has been used to display many proteins and is robust. The advantage of fUSE5 is its low toxicity. This is due to the low copy number of the replication form (RF) in the host, which in turn makes it difficult to prepare a sufficient amount of RF for library construction (Smith & Scott, 1993).
Construction of Libraries
[0126] The first library was constructed of the Fn3 domain displayed on the surface of MB phage in which seven residues (77-83) in the FG loop ( FIG. 4D ) were randomized.
[0127] Randomization will be achieved by the use of an oligonucleotide containing degenerated nucleotide sequence. A double-stranded nucleotide was prepared by the same protocol as for gene synthesis (see above) except that one strand had an (NNK) 6 (NNG) sequence at the mutation sites, where N corresponds to an equimolar Mixture of A, T, G and C and K corresponds to an equimolar mixture of G and T. The (NNG) codon at residue 83 was required to conserve the Sad restriction site ( FIG. 2 ). The (NNK) codon codes all of the 20 amino acids, while the NNG codon codes 14. Therefore, this library contained ˜10 9 independent sequences. The library was constructed by ligating the double-stranded nucleotide into the wild-type phage vector, pASM1, and the transfecting E. coli XL1 blue (Stratagene) using electroporation. XL1 blue has the lacI q phenotype and thus suppresses the expression of the Fn3-pIII fusion protein in the absence of lac inducers. The initial library was propagated in this way, to avoid selection against toxic Fn3-pIII clones. Phages displaying the randomized Fn3-pIII fusion protein were prepared by propagating phages with K91kan as the host. K91kan does not suppress the production of the fusion protein, because it does not have lacI q . Another library was also generated in which the BC loop (residues 26-20) was randomized.
Selection of Displayed FnAbs
[0128] Screening of Fn3 phage libraries was performed using the biopanning protocol (Smith & Scott, 1993); a ligand is biotinylated and the strong biotinstreptavidin interaction was used to immobilize the ligand on a streptavidin-coated dish. Experiments were performed at room temperature (−22° C.). For the initial recovery of phages from a library, 10 μg of a biotinylated ligand were immobilized on a streptavidin-coated polystyrene dish (35 mm, Falcon 1008) and then a phage solution. (containing ˜10 11 pfu (plaque-forming unit)) was added. After washing the dish with an appropriate buffer (typically TEST, Tris-HCl (50 mM, pH 7.5), NaCl (150 mM) and Tween 20 (0.5%)), bound phages were eluted by one or combinations of the following conditions: low pH, an addition of a free ligand, urea (up to 6 M) and, in the case of anti-protein G FnAbs, cleaving the protein G-biotin linker by thrombin. Recovered phages were amplified using the standard protocol using K91kan as the host (Sambrook et al., 1989). The selection process were repeated 3-5 times to concentrate positive clones. From the second round on, the amount of the ligand were gradually decreased (to ˜1 μg) and the biotinylated ligand were mixed with a phage solution before transferring a dish (G. P. Smith, personal communication). After the final round, 10-20 clones were picked, and their DNA sequence will be determined. The ligand affinity of the clones were measured first by the phage-ELISA method (see below).
[0129] To suppress potential binding of the Fn3 framework (background binding) to a ligand, wild-type Fn3 may be added as a competitor in the buffers. In addition, unrelated proteins (e.g., bovine serum albumin, cytochrome c and RNase A) may be used as competitors to select highly specific FnAbs.
Binding Assay
[0130] The binding affinity of FnAbs on phage surface is characterized semiquantitatively using the phage ELISA technique (Li et al., 1995). Wells of microtiter plates (Nunc) are coated with a ligand protein (or with streptavidin followed by the binding of a biotinylated ligand) and blocked with the BLOTTO solution (Pierce). Purified phages pfu) originating from single plaques (M13)/colonies (fUSE5) are added to each well and incubated overnight at 4° C. After washing wells with an appropriate buffer (see above), bound phages are detected by the standard ELISA protocol using anti-M13 Ab (rabbit, Sigma) and anti-rabbit Ig-peroxidase conjugate (Pierce) or using anti-M13 Ab-peroxidase conjugate (Pharmacia). Colormetric assays are performed using TMB (3,3′,5,5′-tetramethylbenzidine, Pierce). The high affinity of protein G to immunoglobulins present a special problem; Abs cannot be used in detection. Therefore, to detect anti-protein G FnAbs, fusion phages are immobilized in wells and the binding is then measured using biotinylated protein G followed by the detection using streptavidin-peroxidase conjugate.
Production of Soluble FnAbs
[0131] After preliminary characterization of mutant Fn3s using phage ELISA, mutant genes are subcloned into the expression vector pEW1. Mutant proteins are produced as His•tag fusion proteins and purified, and their conformation, stability and ligand affinity are characterized.
[0132] Thus, Fn3 is the fourth example of a monomeric immunoglobulin-like scaffold that can be used for engineering binding proteins. Successful selection of novel binding proteins have also been based on minibody, tendamistat and “camelized” immunoglobulin VH domain scaffolds (Martin et al., 1994; Davies & Riechmann, 1995; McConnell & Hoess, 1995). The Fn3 scaffold has advantages over these systems. Bianchi et al. reported that the stability of a minibody was 2.5 kcal/mol, significantly lower than that of Ubi4-K. No detailed structural characterization of minibodies has been reported to date. Tendamistat and the VH domain contain disulfide bonds, and thus preparation of correctly folded proteins may be difficult Davies and Riechmann reported that the yields of their camelized VH domains were less than 1 mg per liter culture (Davies & Riechmann, 1996).
[0133] Thus, the Fn3 framework can be used as a scaffold for molecular recognition. Its small size, stability and well-characterized structure make Fn3 an attractive system. In light of the ubiquitous presence of Fn3 in a wide variety of natural proteins involved in ligand binding, one can engineer Fn3-based binding proteins to different classes of targets.
[0134] The following examples are intended to illustrate but not limit the invention.
Example I
Construction of the Fn3 Gene
[0135] A synthetic gene for tenth Fn3 of fibronectin ( FIG. 1 ) was designed on the basis of amino acid residue 1416-1509 of human fibronectin (Kornblihtt, et al., 1985) and its three dimensional structure (Main, et al., 1992). The gene was engineered to include convenient restriction sites for mutagenesis and the so-called “preferred codons” for high level protein expression (Gribskov, et al., 1984) were used. In addition, a glutamine residue was inserted after the N-terminal methionine in order to avoid partial processing of the N-terminal methionine which often degrades NMR spectra (Smith, et al., 1994). Chemical reagents were of the analytical grade or better and purchased from Sigma Chemical Company and J. T. Baker, unless otherwise noted. Recombinant DNA procedures were performed as described in “Molecular Cloning” (Sambrook, et al., 1989), unless otherwise stated. Custom oligonucleotides were purchased from Operon Technologies. Restriction and modification enzymes were from New England Biolabs.
[0136] The gene was assembled in the following manner. First, the gene sequence ( FIG. 5 ) was divided into five parts with boundaries at designed restriction sites: fragment 1, NdeI-PstI (oligonucleotides FN 1F and FN1R (Table 2); fragment 2, PstI-EcoRI (FN2F and FN2R); fragment 3, EcoRI-SaII (FN3F and FN3R); fragment 4, SaII-Sad (FN4F and FN4R); fragment 5, SacI-BamHI (FN5F and FN5R). Second, for each part, a pair of oligonucleotides which code opposite strands and have complementary overlaps of approximately 15 bases was synthesized. These oligonucleotides were designated FN1F-FN5R and are shown in Table 2. Third, each pair (e.g., FN1F and FN1R) was annealed and single-strand regions were filled in using the Klenow fragment of DNA polymerase. Fourth, the double stranded oligonucleotide was digested with the relevant restriction enzymes at the termini of the fragment and cloned into the PBLUESCRIPT SK plasmid (Stratagene) which had been digested with the same enzymes as those used for the fragments. The DNA sequence of the inserted fragment was confirmed by DNA sequencing using an Applied Biosystems DNA sequencer and the dideoxy termination protocol provided by the manufacturer. Last, steps 2-4 were repeated to obtain the entire gene. The gene was also cloned into the pET3a and pET15b (Novagen) vectors (pAS45 and pAS25, respectively). The maps of the plasmids are shown in FIGS. 6 and 7 . E. coli BL21 (DE3) (Novagen) containing these vectors expressed the Fn3 gene under the control of bacteriophage T7 promotor (Studier, et al., 1990); pAS24 expresses the 96-residue Fn3 protein only, while pAS45 expresses Fn3 as a fusion protein with poly-histidine peptide (His•tag). High level expression of the Fn3 protein and its derivatives in E. coli was detected as an intense band on SDS-PAGE stained with CBB.
[0137] The binding reaction of the monobodies is characterized quantitatively by means of fluorescence spectroscopy using purified soluble monobodies.
[0138] Intrinsic fluorescence is monitored to measure binding reactions. Trp fluorescence (excitation at ˜290 nm, emission at 300 350 nm) and Tyr fluorescence (excitation at ˜260 nm, emission at ˜303 nm) is monitored as the Fn3-mutant solution (≦100 μM) is titrated with a ligand solution. When a ligand is fluorescent (e.g. fluorescein), fluorescence from the ligand may be used K d of the reaction will be determined by the nonlinear least-squares fitting of the bimolecular binding equation.
[0139] If intrinsic fluorescence cannot be used to monitor the binding reaction, monobodies are labeled with fluorescein-NHS (Pierce) and fluorescence polarization is used to monitor the binding reaction (Burke et al., 1996).
Example II
Modifications to Include Restriction Sites in the Fn3 Gene
[0140] The restriction sites were incorporated in the synthetic Fn3 gene without changing the amino acid sequence Fn3. The positions of the restriction sites were chosen so that the gene construction could be completed without synthesizing long (>60 bases) oligonucleotides and so that two loop regions could be mutated (including by randomization) by the cassette mutagenesis method (i.e., swapping a fragment with another synthetic fragment containing mutations). In addition, the restriction sites were chosen so that most sites were unique in the vector for phage display. Unique restriction sites allow one to recombine monobody clones which have been already selected in order to supply a larger sequence space.
Example III
Construction of M13 Phage Display Libraries
[0141] A vector for phage display, pAS38 (for its map, see FIG. 8 ) was constructed as follows. The XbaI-BamHI fragment of pET12a encoding the signal peptide of OmpT was cloned at the 5′ end of the Fn3 gene. The C-terminal region (from the FN5F and FN5R′ oligonucleotides, see Table 2) of the Fn3 gene was replaced with a new fragment consisting of the FN5F and FN5R′ oligonucleotides (Table 2) which introduced a MluI site and a linker sequence for making a fusion protein with the pill protein of bacteriophage .M13. A gene fragment coding the C-terminal domain of M13 pIII was prepared from the wild-type gene III of M13 mp 18 using PCR (Corey, et al., 1993) and the fragment was inserted at the 3′ end of the OmpT-Fn3 fusion gene using the MluI and HindIII sites.
[0142] Phages were produced and purified using a helper phage, M13K07, according to a standard method (Sambrook, et al., 1989) except that phage particles were purified by a second polyethylene glycol precipitation. Successful display of Fn3 on fusion phages was confirmed by ELISA (Harlow & Lane, 1988) using an antibody against fibronectin (Sigma) and a custom anti-FN3 antibody (Cocalico Biologicals, PA, USA).
Example IV
Libraries Containing Loop Variegations in the AB Loop
[0143] A nucleic acid phage display library having variegation in the AB loop is prepared by the following methods. Randomization is achieved by the use of oligonucleotides containing degenerated nucleotide sequence. Residues to be variegated are identified by examining the X-ray and NMR structures of Fn3 (Protein Data Bank accession numbers, 1FNA and 1TTF, respectively). Oligonucleotides containing NNK. (N and K here denote an equimolar mixture of A, T, G, and C and an equimolar mixture of G and T, respectively) for the variegated residues are synthesized (see oligonucleotides BC3, FG2, FG3, and FG4 in Table 2 for example). The NNK mixture codes for all twenty amino acids and one termination codon (TAG). TAG, however, is suppressed in the E. coli XL-1 blue. Single-stranded DNAs of pAS38 (and its derivatives) are prepared using a standard protocol (Sambrook, et al., 1989).
[0144] Site-directed mutagenesis is performed following published methods (see for example, Kunkel, 1985) using a MUTA-GENE kit (BioRad). The libraries are constructed by electroporation of E. coli XL-1 Blue electroporation competent cells (200 μl ; Stratagene) with 1 μg of the plasmid DNA using a BTX electrocell manipulator ECM 395 1 mm gap cuvette. A portion of the transformed cells is plated on an LB-agar plate containing ampicillin (100 μg/ml) to determine the transformation efficiency. Typically, 3×10 8 transformants are obtained with 1 μg of DNA, and thus a library contains 10 8 to 10 9 independent clones. Phagemid particles were prepared as described above.
Example V
Loop Variegations in the BC, CD, DE, EF or FG Loop
[0145] A nucleic acid phage display library having five variegated residues (residues number 26-30) in the BC loop, and one having seven variegated residues (residue numbers 78-84) in the FG loop, was prepared using the methods described in Example IV above. Other nucleic acid phage display libraries having variegation in the CD, DE or EF loop can be prepared by similar methods.
Example VI
Loop Variegations in the FG and BC Loop
[0146] A nucleic acid phage display library having seven variegated residues (residues number 78-84) in the FG loop and five variegated residues (residue number 26-30) in the BC loop was prepared. Variegations in the BC loop were prepared by site-directed mutagenesis (Kunkel, et al.) using the BC3 oligonucleotide described in Table 1. Variegations in the FG loop were introduced using site-directed mutagenesis using the BC loop library as the starting material, thereby resulting in libraries containing variegations in both BC and FG loops. The oligonucleotide FG2 has variegating residues 78-84 and oligonucleotide FG4 has variegating residues 77-81 and a deletion of residues 82-84.
[0147] A nucleic acid phage display library having five variegated residues (residues 78-84) in the FG loop and a three residue deletion (residues 82-84) in the FG loop, and five variegated residues (residues 26-30) in the BC loop, was prepared: The shorter FG loop was made in an attempt to reduce the flexibility of the FG loop; the loop was shown to be highly flexible in Fn3 by the NMR studies of Main, et al. (1992). A highly flexible loop may be disadvantageous to forming a binding site with a high affinity (a large entropy loss is expected upon the ligand binding, because the flexible loop should become more rigid). In addition, other Fn3 domains (besides human) have shorter FG loops (for sequence alignment, see FIG. 12 in Dickinson, et al. (1994)).
[0148] Randomization was achieved by the use of oligonucleotides containing degenerate nucleotide sequence (oligonucleotide BC3 for variegating the BC loop and oligonucleotides FG2 and FG4 for variegating the FG loops).
[0149] Site-directed mutagenesis was performed following published methods (see for example, Kunkel, 1985). The libraries were constructed by electrotransforming E. coli XL-1 Blue (Stratagene). Typically a library contains 10 8 to 10 9 independent clones. Library 2 contains five variegated residues in the BC loop and seven variegated residues in the FG loop. Library 4 contains five variegated residues in each of the BC and FG loops, and the length of the FG loop was shortened by three residues.
Example VII
fd Phage Display Libraries Constructed with Loop Variegations
[0150] Phage display libraries are constructed using the fd phage as the genetic vector. The Fn3 gene is inserted in fUSE5 (Parmley & Smith, 1988) using SflI restriction sites which are introduced at the 5′ and 3′ ends of the Fn3 gene using PCR. The expression of this phage results in the display of the fusion pill protein on the surface of the fd phage. Variegations in the Fn3 loops are introduced using site-directed mutagenesis as described hereinabove, or by subcloning the Fn3 libraries constructed in M13 phage into the fUSE5 vector.
Example VIII
Other Phage Display Libraries
[0151] T7 phage libraries (Novagen, Madison, Wis.) and bacterial pili expression systems (Invitrogen) are also useful to express the Fn3 gene.
Example Ix
Isolation of Polypeptides which Bind to Macromolecular Structures
[0152] The selection of phage-displayed monobodies was performed following the protocols of Barbas and coworkers (Rosenblum & Barbas, 1995). Briefly, approximately 1 μg of a target molecule (“antigen”) in sodium carbonate buffer (100 mM, pH 8.5) was immobilized in the wells of a microtiter plate (Maxisorp, Nunc) by incubating overnight at 4° C. in an air tight container. After the removal of this solution, the wells were then blocked with a 3% solution of BSA (Sigma, Fraction V) in TBS by incubating the plate at 37° C. for 1 hour. A phagemid library solution (50 μl) containing approximately 10 12 colony forming units (cfu) of phagemid was absorbed in each well at 37° C. for 1 hour. The wells were then washed with an appropriate buffer (typically TBST, 50 mM Tris-HCl (pH 7.5), 150 mM NaCl, and 0.5% Tween20) three times (once for the first round). Bound phage were eluted by an acidic solution (typically, 0.1 M glycine-HCl, pH 2.2; 50 pd) and recovered phage were immediately neutralized with 3 μl of Tris solution. Alternatively, bound phage were eluted by incubating the wells with 50 μl of TBS containing the antigen (1-10 μM). Recovered phage were amplified using the standard protocol employing the XL1Blue cells as the host (Sambrook, et al.). The selection process was repeated 5-6 times to concentrate positive clones. After the final round, individual clones were picked and their binding affinities and DNA sequences were determined.
[0153] The binding affinities of monobodies on the phage surface were characterized using the phage ELISA technique (Li, et al., 1995). Wells of microtiter plates (Nunc) were coated with an antigen and blocked with BSA. Purified phages (10 8 -10 11 cfu) originating from a single colony were added to each well and incubated 2 hours at 37° C. After washing wells with an appropriate buffer (see above), bound phage were detected by the standard ELISA protocol using antiM13 antibody (rabbit, Sigma) and anti-rabbit Ig-peroxidase conjugate (Pierce). Colorimetric assays were performed using Turbo-TMB (3,3′,5,5′-tetramethylbenzidine, Pierce) as a substrate.
[0154] The binding affinities of monobodies on the phage surface were further characterized using the competition ELISA method (Djavadi-Ohaniance, et al., 1996). In this experiment, phage ELISA is performed in the same manner as described above, except that the phage solution contains a ligand at varied concentrations. The phage solution was incubated a 4° C. for one hour prior to the binding of an immobilized ligand in a microtiter plate well. The affinities of phage displayed monobodies are estimated by the decrease in ELISA signal as the free ligand concentration is increased.
[0155] After preliminary characterization of monobodies displayed on the surface of phage using phage ELISA, genes for positive clones were subcloned into the expression vector pAS45. E. Coli BL21(DE3) (Novagen) was transformed with an expression vector (pAS45 and its derivatives). Cells were grown in M9 minimal medium and M9 medium supplemented with Bactotryptone (Difco) containing ampicillin (200 μg/ml). For isotopic labeling, 15 N NH 4 Cl and/or 13 C glucose replaced unlabeled components. Stable isotopes were purchased from Isotec and Cambridge Isotope Labs. 500 ml medium in a 2 1 baffle flask was inoculated with 10 ml of overnight culture and agitated at approximately 140 rpm at 37° C. IPTG was added at a final concentration of 1 mM to induce protein expression when OD(600 nm) reached approximately 1.0. The cells were harvested by centrifugation 3 hours after the addition of IPTG and kept frozen at −70° C. until used.
[0156] Fn3 and monobodies with His•tag were purified as follows. Cells were suspended in 5 ml/(g cell) of 50 mM Tris (pH 7.6) containing 1 mM phenylmethylsulfonyl fluoride. HEL (Sigma, 3×crystallized) was added to a final concentration of 0.5 mg/ml. After incubating the solution for 30 min at 37° C., it was sonicated so as to cause cell breakage three times for 30 seconds on ice. Cell debris was removed by centrifugation at 15,000 rpm in an Sorval RC-2B centrifuge using an SS-34 rotor. Concentrated sodium chloride is added to the solution to a final concentration of 0.5 M. The solution was then applied to a 1 ml HISTRAP™ chelating column (Pharmacia) preloaded with nickel chloride (0.1 M, 1 ml) and equilibrated in the Tris buffer (50 mM, pH 8.0) containing 0.5 M sodium chloride. After washing the column with the buffer, the bound protein was eluted with a Tris buffer (50 mM, pH 8.0) containing 0.5 M imidazole. The His•tag portion was cleaved off, when required, by treating the fusion protein with thrombin using the protocol supplied by Novagen (Madison, Wis.). Fn3 was separated from the His•tag peptide and thrombin by a RESOURCES® column (Pharmacia) using a linear gradient of sodium chloride (0-0.5 M) in sodium acetate buffer (20 mM, pH 5.0).
[0157] Small amounts of soluble monobodies were prepared as follows. XL-1 Blue cells containing pAS38 derivatives (plasmids coding Fn3-pIII fusion proteins) were grown in LB media at 37° C. with vigorous shaking until OD(600 nm) reached approximately 1.0; IPTG was added to the culture to a final concentration of 1 mM, and the cells were further grown overnight at 37° C. Cells were removed from the medium by centrifugation, and the supernatant was applied to a microtiter well coated with a ligand. Although XL-1 Blue cells containing pAS38 and its derivatives express FN3-pIII fusion proteins, soluble proteins are also produced due to the cleavage of the linker between the Fn3 and pIII regions by proteolytic activities of E. coli (Rosenblum & Barbas, 1995). Binding of a monobody to the ligand was examined by the standard ELISA protocol using a custom antibody against Fn3 (purchased from Cocalico Biologicals, Reamstown, Pa.). Soluble monobodies obtained from the periplasmic fraction of E. coli cells using a standard osmotic shock method were also used.
Example X
Ubiquitin Binding Monobody
[0158] Ubiquitin is a small (76 residue) protein involved in the degradation pathway in eurkaryotes. It is a single domain globular protein. Yeast ubiquitin was purchased from Sigma Chemical Company and was used without further purification.
[0159] Libraries 2 and 4, described in Example VI above, were used to select ubiquitin-binding monobodies. Ubiquitin (1 μg in 50 μl sodium bicarbonate buffer (100 mM, pH 8.5)) was immobilized in the wells of a microtiter plate, followed by blocking with BSA (3% in TBS). Panning was performed as described above. In the first two rounds, 1 μg of ubiquitin was immobilized per well, and bound phage were elute with an acidic solution. From the third to the sixth rounds, 0.1 μg of ubiquitin was immobilized per well and the phage were eluted either with an acidic solution or with TBS containing 10 μM ubiquitin.
[0160] Binding of selected clones was tested first in the polyclonal mode, i.e., before isolating individual clones. Selected clones from all libraries showed significant binding to ubiquitin. These results are shown in FIG. 9 . The binding to the immobilized ubiquitin of the clones was inhibited almost completely by less than 30 μm soluble ubiquitin in the competition ELISA experiments (see. FIG. 10 ). The sequences of the BC and FG loops of ubiquitin-binding monobodies is shown in Table 3.
[0000]
TABLE 3
Sequences of ubiquitin-binding monobodies
Occurrence
(if more
Name
BC loop
FG loop
than one)
211
CARRA (SEQ ID NO: 31)
RWIPLAK (SEQ ID NO: 32)
2
212
CWRRA (SEQ ID NO: 33)
RWVGLAW (SEQ ID NO: 34)
213
CKHRR (SEQ ID NO: 35)
FADLWWR (SEQ ID NO: 36)
214
CRRGR (SEQ ID NO: 37)
RGFMWLS (SEQ ID NO: 38)
215
CNWRR (SEQ ID NO: 39)
RAYRYRW (SEQ ID NO: 40)
411
SRLRR (SEQ ID NO: 41)
PPWRV (SEQ ID NO: 42)
9
422
ARWTL (SEQ ID NO: 43)
RRWWW (SEQ ID NO: 44)
424
GQRTF (SEQ ID NO: 45)
RRWWA (SEQ ID NO: 46)
[0161] The 411 clone, which was the most enriched clone, was characterized using phage ELISA. The 411 clone showed selective binding and inhibition of binding in the presence of about 10 μM ubiquitin in solution ( FIG. 11 ).
Example XI
Methods for the Immobilization of Small Molecules
[0162] Target molecules were immobilized in wells of a microtiter plate (MAXISORP, Nunc) as described hereinbelow, and the wells were blocked with BSA. In addition to the use of carrier protein as described below, a conjugate of a target molecule in biotin can be made. The biotinylated ligand can then be immobilized to a microtiter plate well which has been coated with streptavidin.
[0163] In addition to the use of a carrier protein as described below, one could make a conjugate of a target molecule and biotin (Pierce) and immobilize a biotinylated ligand to a microtiter plate well which has been coated with streptavidin (Smith and Scott, 1993).
[0164] Small molecules may be conjugated with a carrier protein such as bovine serum albumin (BSA, Sigma), and passively adsorbed to the microtiter plate well. Alternatively, methods of chemical conjugation can also be used. In addition, solid supports other than microtiter plates can readily be employed.
Example XII
Fluorescein Binding Monobody
[0165] Fluorescein has been used as a target for the selection of antibodies from combinatorial libraries (Barbas, et al. 1992). NHS-fluorescein was obtained from Pierce and used according to the manufacturer's instructions in preparing conjugates with BSA (Sigma). Two types of fluorescein-BSA conjugates were prepared with approximate molar ratios of 17 (fluorescein) to one (BSA).
[0166] The selection process was repeated 5-6 times to concentrate positive clones. In this experiment, the phage library was incubated with a protein mixture (BSA, cytochrome C (Sigma, Horse) and RNaseA (Sigma, Bovine), 1 mg/ml each) at room temperature for 30 minutes, prior to the addition to ligand coated wells. Bound phage were eluted in TBS containing 10 μM soluble fluorescein, instead of acid elution. After the final round, individual clones were picked and their binding affinities (see below) and DNA sequences were determined.
[0000]
TABLE 4
BC
FG
Clones from Library #2
WT
AVTVR (SEQ ID NO: 47)
RGDSPAS (SEQ ID NO: 48)
pLB24.1
CNWRR (SEQ ID NO: 49)
RAYRYRW (SEQ ID NO: 50)
pLB24.2
CMWRA (SEQ ID NO: 51)
RWGMLRR (SEQ ID NO: 52)
pLB24.3
ARMRE (SEQ ID NO: 53)
RWLRGRY (SEQ ID NO: 54)
pLB24.4
CARRR (SEQ ID NO: 55)
RRAGWGW (SEQ ID NO: 56)
pLB24.5
CNWRR (SEQ ID NO: 57)
RAYRYRW (SEQ ID NO: 58)
pLB24.6
RWRER (SEQ ID NO: 59)
RHPWTER (SEQ ID NO: 60)
pLB24.7
CNWRR (SEQ ID NO: 61)
RAYRYRW (SEQ ID NO: 62)
pLB24.8
ERRVP (SEQ ID NO: 63)
RLLLWQR (SEQ ID NO: 64)
pLB24.9
GRGAG (SEQ ID NO: 65)
FGSFERR (SEQ ID NO: 66)
pLB24.11
CRWTR (SEQ ID NO: 67)
RRWFDGA (SEQ ID NO: 68)
pLB 24.12
CNWRR (SEQ ID NO: 69)
RAYRYRW (SEQ ID NO: 70)
Clones from Library #4
WT
AVTVR (SEQ ID NO: 71)
GRGDS (SEQ ID NO: 72)
pLB25.1
GQRTF (SEQ ID NO: 73)
RRWWA (SEQ ID NO: 74)
pLB25.2
GQRTF (SEQ ID NO: 75)
RRWWA (SEQ ID NO: 76)
pLB25.3
GQRTF (SEQ ID NO: 77)
RRWWA (SEQ ID NO: 78)
pLB25.4
LRYRS (SEQ ID NO: 79)
GWRWR (SEQ ID NO: 80)
pLB25.5
GQRTF (SEQ ID NO: 81)
RRWWA (SEQ ID NO: 82)
pLB25.6
GQRTF (SEQ ID NO: 83)
RRWWA (SEQ ID NO: 84)
pLB25.7
LRYRS (SEQ ID NO: 85)
GWRWR (SEQ ID NO: 86)
pLB25.9
LRYRS (SEQ ID NO: 87)
GWRWR (SEQ ID NO: 88)
pLB25.11
GQRTF (SEQ ID NO: 89)
RRWWA (SEQ ID NO: 90)
pLB25.12
LRYRS (SEQ ID NO: 91)
GWRWR (SEQ ID NO: 92)
[0167] Preliminary characterization of the binding affinities of selected clones were performed using phage ELISA and competition phage ELISA (see FIG. 12 (Fluorescein-1) and FIG. 13 (Fluorescein-2)). The four clones tested showed specific binding to the ligand-coated wells, and the binding reactions are inhibited by soluble fluorescein (see FIG. 13 ).
Example XIII
Digoxigenin Binding Monobody
[0168] Digoxigenin-3-O-methyl-carbonyl-e-aminocapronic acid-NHS (Boehringer Mannheim) is used to prepare a digoxigenin-BSA conjugate. The coupling reaction is performed following the manufacturers' instructions. The digoxigenin-BSA conjugate is immobilized in the wells of a microtiter plate and used for panning. Panning is repeated 5 to 6 times to enrich binding clones. Because digoxigenin is sparingly soluble in aqueous solution, bound phages are eluted from the well using acidic solution. See Example XIV.
Example XIV
TSAC (Transition State Analog Compound) Binding Monobodies
[0169] Carbonate hydrolyzing monobodies are selected as follows. A transition state analog for carbonate hydrolysis, 4-nitrophenyl phosphonate is synthesized by an Arbuzov reaction as described previously (Jacobs and Schultz, 1987). The phosphonate is then coupled to the carrier protein, BSA, using carbodiimide, followed by exhaustive dialysis (Jacobs and Schultz, 1987). The hapten-BSA conjugate is immobilized in the wells of a microtiter plate and monobody selection is performed as described above. Catalytic activities of selected monobodies are tested using 4-nitrophenyl carbonate as the substrate.
[0170] Other haptens useful to produce catalytic monobodies are summarized in H. Suzuki (1994) and in N. R. Thomas (1994).
Example XV
NMR Characterization of Fn3 and Comparison of the Fn3 Secreted by Yeast with that Secreted by E. coli
[0171] Nuclear magnetic resonance (NMR) experiments are performed to identify the contact surface between FnAb and a target molecule; e.g., monobodies to fluorescein, ubiquitin, RNaseA and soluble derivatives of digoxigenin. The information is then be used to improve the affinity and specificity of the monobody. Purified monobody samples are dissolved in an appropriate buffer for NMR spectroscopy using Amicon ultrafiltration cell with a YM-3 membrane. Buffers are made with 90% H 2 O/10% D 2 O (distilled grade, Isotec) or with 100% D 2 O. Deuterated compounds (e.g. acetate) are used to eliminate strong signals from them.
[0172] NMR experiments are performed on a Varian Unity INOVA 600 spectrometer equipped with four RF channels and a triple resonance probe with pulsed field gradient capability. NMR spectra are analyzed using processing programs such as FELIX (Molecular Simulations), NMRPIPE, PIPP, and CAPP (Garrett, et al., 1991; Delaglio, et al., 1995) on UNIX workstations. Sequence specific resonance assignments are made using well-established strategy using a set of triple resonance experiments (CBCA(CO)NH and HNCACB) (Grzesiek & Bax, 1992; Wittenkind & Mueller, 1993).
[0173] Nuclear Overhauser effect (NOE) is observed between 1 H nuclei closer than approximately 5 Å, which allows one to obtain information on interproton distances. A series of double- and triple-resonance experiments (Table 5; for recent reviews on these techniques, see Bax & Grzesiek, 1993 and Kay, 1995) are performed to collect distance (i.e. NOE) and dihedral angle (J-coupling) constraints. Isotope-filtered experiments are performed to determine resonance assignments of the bound ligand and to obtain distance constraints within the ligand and those between FnAb and the ligand. Details of sequence specific resonance assignments and NOE peak assignments have been described in detail elsewhere (Clore & Gronenbom, 1991; Pascal, et al., 1994b; Metzler, et al., 1996).
[0000]
TABLE 5
NMR experiments for structure characterization
Experiment Name
Reference
1. reference spectra
2D- 1 H, 15 N-HSQC
(Bodenhausen & Ruben,
1980; Kay, et al., 1992)
2D- 1 H, 13 C-HSQC
(Bodenhausen & Ruben,
1980; Vuister & Bax, 1992)
2. backbone and side chain resonance assignments of
13 C/ 15 N-labeled protein
3D-CBCA(CO)NH
(Grzesiek & Bax, 1992)
3D-HNCACB
(Wittenkind & Mueller,
1993)
3D-C(CO)NH
(Logan et al., 1992;
Grzesiek et al., 1993)
3D-H(CCO)NH
3D-HBHA(CBCACO)NH
(Grzesiek & Bax, 1993)
3D-HCCH-TOCSY
(Kay et al., 1993)
3D-HCCH-COSY
(Ikura et al., 1991)
3D- 1 H, 15 N-TOCSY-HSQC
(Zhang et al., 1994)
2D-HB(CBCDCE)HE
(Yamazaki et al., 1993)
3. resonance assignments of unlabeled ligand
2D-isotope-filtered 1 H-TOCSY
2D-isotope-filtered 1 H-COSY
2D-isotope-filtered 1 H-NOESY
(lkura & Bax, 1992)
4. structural constraints
within labeled protein
3D- 1 H, 15 N-NOESY-HSQC
(Zhang et al., 1994)
4D- 1 H, 13 C-HMQC-NOESY-HMQC
(Vuister et al., 1993)
4D- 1 H, 13 C, 15 N-HSQC-NOESY-HSQC
(Muhandiram et al., 1993;
Pascal et al., 1994a)
within unlabeled ligand
2D-isotope-filtered 1 H-NOESY
(Ikura & Bax, 1992)
interactions between protein and ligand
3D-isotope-filtered 1 H, 15 N-NOESY-HSQC
3D-isotope-filtered 1 H, 13 C-NOESY-HSQC
(Lee et al., 1994)
5. dihedral angle constraints
J-molulated 1 H, 15 N-HSQC
(Billeter et al., 1992)
3D-HNHB
(Archer et al., 1991)
[0174] Backbone 1 H, 15 N and 3 C resonance assignments for a monobody are compared to those for wild-type Fn3 to assess structural changes in the mutant. Once these data establish that the mutant retains the global structure, structural refinement is performed using experimental NOE data. Because the structural difference of a monobody is expected to be minor, the wild-type structure can be used as the initial model after modifying the amino acid sequence. The mutations are introduced to the wild-type structure by interactive molecular modeling, and then the structure is energy-minimized using a molecular modeling program such as QUANTA (Molecular Simulations). Solution structure is refined using cycles of dynamical simulated annealing (Nilges et al., 1988) in the program X-PLOR (Brünger, 1992). Typically, an ensemble of fifty structures is calculated. The validity of the refined structures is confirmed by calculating a fewer number of structures from randomly generated initial structures in X-PLOR using the YASAP protocol (Nilges, et al., 1991). Structure of a monobody-ligand complex is calculated by first refining both components individually using intramolecular NOEs, and then docking the two using intermolecular NOEs.
[0175] For example, the 1 H, 5 N—HSQC spectrum for the fluorescein-binding monobody LB25.5 is shown in FIG. 14 . The spectrum shows a good dispersion (peaks are spread out) indicating that LB25.5 is folded into a globular conformation. Further, the spectrum resembles that for the wild-type Fn3, showing that the overall structure of LB25.5 is similar to that of Fn3. These results demonstrate that ligand-binding monobodies can be obtained without changing the global fold of the Fn3 scaffold.
[0176] Chemical shift perturbation experiments are performed by forming the complex between an isotope-labeled FnAb and an unlabeled ligand. The formation of a stoichiometric complex is followed by recording the HSQC spectrum. Because chemical shift is extremely sensitive to nuclear environment, formation of a complex usually results in substantial chemical shift changes for resonances of amino acid residues in the interface. Isotope-edited NMR experiments (2D HSQC and 3D CBCA(CO)NH) are used to identify the resonances that are perturbed in the labeled component of the complex; i.e. the monobody. Although the possibility of artifacts due to long-range conformational changes must always be considered, substantial differences for residues clustered on continuous surfaces are most likely to arise from direct contacts (Chen et al., 1993; Gronenbom & Clore, 1993).
[0177] An alternative method for mapping the interaction surface utilizes amide hydrogen exchange (HX) measurements. HX rates for each amide proton are measured for 15 N labeled monobody both free and complexed with a ligand. Ligand binding is expected to result in decreased amide HX rates for monobody residues in the interface between the two proteins, thus identifying the binding surface. HX rates for monobodies in the complex are measured by allowing HX to occur for a variable time following transfer of the complex to D 2 O; the complex is dissociated by lowering pH and the HSQC spectrum is recorded at low pH where amide HX is slow. Fn3 is stable and soluble at low pH, satisfying the prerequisite for the experiments.
Example XVI
Construction and Analysis of Fn3-Display System Specific for Ubiquitin
[0178] An Fn3-display system was designed and synthesized, ubiquitin-binding clones were isolated and a major Fn3 mutant in these clones was biophysically characterized.
[0179] Gene construction and phage display of Fn3 was performed as in Examples I and II above. The Fn3-phage pill fusion protein was expressed from a phagemid-display vector, while the other components of the M13 phage, including the wildtype were produced using a helper phage (Bass et al., 1990). Thus, a phage produced by this system should contain less than one copy of Fn3 displayed on the surface. The surface display of Fn3 on the phage was detected by ELISA using an anti-Fn3 antibody. Only phages containing the Fn3-pIII fusion vector reacted with the antibody.
[0180] After confirming the phage surface to display Fn3, a phage display library of Fn3 was constructed as in Example III. Random sequences were introduced in the BC and FG loops. In the first library, five residues (77-81) were randomized and three residues (82-84) were deleted from the FG loop. The deletion was intended to reduce the flexibility and improve the binding affinity of the FG loop. Five residues (26-30) were also randomized in the BC loop in order to provide a larger contact surface with the target molecule. Thus, the resulting library contains five randomized residues in each of the BC and FG loops (Table 6). This library contained approximately 10 8 independent clones.
Library Screening
[0181] Library screening was performed using ubiquitin as the target molecule. In each round of panning, Fn3-phages were absorbed to a ubiquitin-coated surface, and bound phages were eluted competitively with soluble ubiquitin. The recovery ratio improved from 4.3×10 −7 in the second round to 4.5×10 −6 in the fifth round, suggesting an enrichment of binding clones. After five founds of panning, the amino acid sequences of individual clones were determined (Table 6).
[0000]
TABLE 6
Sequences in the variegated loops of enriched clones
Name
BC loop
FG loop
Frequency
Wild Type
GCAGTTACCGTGCGT
GGCCGTGGTGACAGCCCAGCGAGC
—
(SEQ ID NO: 93)
(SEQ ID NO: 95)
AlaValThrValArg
GlyArgGlyAspSerProAlaSer
(SEQ ID NO: 94)
(SEQ ID NO: 96)
Library a
NNKNNKNNKNNKNNK
NNKNNKNNKNNKNNK---------
—
XXXXX
XXXXX (deletion)
clone1
TCGAGGTTGCGGCGG
CCGCCGTGGAGGGTG
9
(SEQ ID NO: 97)
(SEQ ID NO: 99)
(Ubi4)
SerArgLeuArgArg
ProProTrpArgVal
(SEQ ID NO: 98)
(SEQ ID NO: 100)
clone2
GGTCAGCGAACTTTT
AGGCGGTGGTGGGCT
1
(SEQ ID NO: 101)
(SEQ ID NO: 103)
GlyGlnArgThrPhe
ArgArgTrpTrpAla
(SEQ ID NO: 102)
(SEQ ID NO: 104)
clone3
GCGAGGTGGACGCTT
AGGCGGTGGTGGTGG
1
(SEQ ID NO: 105)
(SEQ ID NO: 107)
AlaArgTrpThrLeu
ArgArgTrpTrpTrp
(SEQ ID NO: 106)
(SEQ ID NO: 108)
a N denotes an equimolar mixture of A, T, G and C; K denotes an equimolar mixture of G and T.
[0182] A clone, dubbed Ubi4, dominated the enriched pool of Fn3 variants. Therefore, further investigation was focused on this Ubi4 clone. Ubi4 contains four mutations in the BC loop (Arg 30 in the BC loop was conserved) and five mutations and three deletions in the FG loop. Thus 13% (12 out of 94) of the residues were altered in Ubi4 from the wild-type sequence.
[0183] FIG. 15 shows a phage ELISA analysis of Ubi4. The Ubi4 phage binds to the target molecule, ubiquitin, with a significant affinity, while a phage displaying the wild-type Fn3 domain or a phase with no displayed molecules show little detectable binding to ubiquitin ( FIG. 15 a ). In addition, the Ubi4 phage showed a somewhat elevated level of background binding to the control surface lacking the ubiquitin coating. A competition ELISA experiments shows the IC 50 (concentration of the free ligand which causes 50% inhibition of binding) of the binding reaction is approximately 5 μM ( FIG. 15 b ). BSA, bovine ribonuclease A and cytochrome C show little inhibition of the Ubi4-ubiquitin binding reaction ( FIG. 15 c ), indicating that the binding reaction of Ubi4 to ubiquitin does result from specific binding.
Characterization of a Mutant Fn3 Protein
[0184] The expression system yielded 50-100 mg Fn3 protein per liter culture. A similar level of protein expression was observed for the Ubi4 clone and other mutant Fn3 proteins.
[0185] Ubi4-Fn3 was expressed as an independent protein. Though a majority of Ubi4 was expressed in E. coli as a soluble protein, its solubility was found to be significantly reduced as compared to that of wild-type Fn3. Ubi4 was soluble up to ˜20 μM at low pH, with much lower solubility at neutral pH. This solubility was not high enough for detailed structural characterization using NMR spectroscopy or X-ray crystallography.
[0186] The solubility of the Ubi4 protein was improved by adding a solubility tail, GKKGK, as a C-terminal extension. The gene for Ubi4-Fn3 was subcloned into the expression vector pAS45 using PCR. The C-terminal solubilization tag, GKKGK, was incorporated in this step. E. coli BL21 (DE3) (Novagen) was transformed with the expression vector (pAS45 and its derivatives). Cells were grown in M9 minimal media and M9 media supplemented with Bactotryptone (Difco) containing ampicillin (200 μg/ml). For isotopic labeling, 15 N NH 4 Cl replaced unlabeled NH 4 Cl in the media. 500 ml medium in a 2 liter baffle flask was inoculated with 10 ml of overnight culture and agitated at 37° C. IPTG was added at a final concentration of 1 mM to initiate protein expression when OD (600 nm) reaches one. The cells were harvested by centrifugation 3 hours after the addition of IPTG and kept frozen at 70° C. until used.
[0187] Proteins were purified, as follows. Cells were suspended in 5 ml/(g cell) of Tris (50 mM, pH 7.6) containing phenylmethylsulfonyl fluoride (1 mM). Hen egg lysozyme (Sigma) was added to a final concentration of 0.5 mg/mL After incubating the solution for 30 minutes at 37° C., it was sonicated three times for 30 seconds on ice. Cell debris was removed by centrifugation. Concentrated sodium chloride was added to the solution to a final concentration of 0.5 M. The solution was applied to a HI-TRAP chelating column (Pharmacia) preloaded with nickel and equilibrated in the Tris buffer containing sodium chloride (0.5 M). After washing the column with the buffer, histag-Fn3 was eluted with the buffer containing 500 mM imidazole. The protein was further purified using a RESOURCES® column (Pharmacia) with a NaCl gradient in a sodium acetate buffer (20 mM, pH 4.6).
[0188] With the GKKGK (SEQ ID NO:109) tail, the solubility of the Ubi4 protein was increased to over 1 mM at low pH and up to ˜50 μM at neutral pH. Therefore, further analyses were performed on Ubi4 with this C-terminal extension (hereafter referred to as Ubi4-K). It has been reported that the solubility of a minibody could be significantly improved by addition of three Lys residues at the N- or C-termini (Bianchi et al.; 1994). In the case of protein Rop, a non-structured C-terminal tail is critical in maintaining its solubility (Smith et al., 1995).
[0189] Oligomerization states of the Ubi4 protein were determined using a size exclusion column. The wild-type Fn3 protein was monomeric at low and neutral pH's. However, the peak of the Ubi4-K protein was significantly broader than that of wild-type Fn3, and eluted after the wild-type protein. This suggests interactions between Ubi4-K and the column material, precluding the use of size exclusion chromatography to determine the oligomerization state of Ubi4. NMR studies suggest that the protein is monomeric at low pH.
[0190] The Ubi4-K protein retained a binding affinity to ubiquitin as judged by ELISA ( FIG. 15 d ). However, an attempt to determine the dissociation constant using a biosensor (Affinity Sensors, Cambridge, U.K.) failed because of high background binding of Ubi4-K-Fn3 to the sensor matrix. This matrix mainly consists of dextran, consistent with our observation that interactions between Ubi4-K interacts with the cross-linked dextran of the size exclusion column.
Example XVII
Stability Measurements of Monobodies
[0191] Guanidine hydrochloride (GuHCl)-induced unfolding and refolding reactions were followed by measuring tryptophan fluorescence. Experiments were performed on a Spectronic AB-2 spectrofluorometer equipped with a motor-driven syringe (Hamilton Co.). The cuvette temperature was kept at 30° C. The spectrofluorometer and the syringe were controlled by a single computer using a home-built interface. This system automatically records a series of spectra following GuHCl titration. An experiment started with a 1.5 ml buffer solution containing 5 μM protein. An emission spectrum (300-400 nm; excitation at 290 nm) was recorded following a delay (3-5 minutes) after each injection (50 or 100 μl) of a buffer solution containing GuHCl. These steps were repeated until the solution volume reached the full capacity of a cuvette (3.0 ml). Fluorescence intensities were normalized as ratios to the intensity at an isofluorescent point which was determined in separate experiments. Unfolding curves were fitted with a two-state model using a nonlinear least-squares routine (Santoro & Bolen, 1988). No significant differences were observed between experiments with delay times (between an injection and the start of spectrum acquisition) of 2 minutes and 10 minutes, indicating that the unfolding/refolding reactions reached close to an equilibrium at each concentration point within the delay times used.
[0192] Conformational stability of Ubi4-K was measured using above-described GuHCl-induced unfolding method. The measurements were performed under two sets of conditions; first at pH 3.3 in the presence of 300 mM sodium chloride, where Ubi4-K is highly soluble, and second in TBS, which was used for library screening. Under both conditions, the unfolding reaction was reversible, and we detected no signs of aggregation or irreversible unfolding. FIG. 16 shows unfolding transitions of Ubi4-K and wild-type Fn3 with the N-terminal (his) 6 tag and the C-terminal solubility tag. The stability of wild-type Fn3 was not significantly affected by the addition of these tags. Parameters characterizing the unfolding transitions are listed in Table 7.
[0000]
TABLE 7
Stability parameters for Ubi4 and wild-type Fn3 as determined
by GuHCl-induced unfolding
Protein
ΔG 0 (kcal mol −1 )
m G (kcal mol −1 M −1 )
Ubi4 (pH 7.5)
4.8 ± 0.1
2.12 ± 0.04
Ubi4 (pH 3.3)
6.5 ± 0.1
2.07 ± 0.02
Wild-type (pH 7.5)
7.2 ± 0.2
1.60 ± 0.04
Wild-type (pH 3.3)
11.2 ± 0.1
2.03 ± 0.02
[0193] ΔG 0 is the free energy of unfolding in the absence of denaturant; m G is the dependence of the free energy of unfolding on GuHCl concentration. For solution conditions, see FIG. 4 caption.
[0194] Though the introduced mutations in the two loops certainly decreased the stability of Ubi4-K relative to wild-type Fn3, the stability of Ubi4 remains comparable to that of a “typical” globular protein. It should also be noted that the stabilities of the wild-type and Ubi4-K proteins were higher at pH 3.3 than at pH 7.5.
[0195] The Ubi4 protein had a significantly reduced solubility as compared to that of wild-type Fn3, but the solubility was improved by the addition of a solubility tail. Since the two mutated loops comprise the only differences between the wild-type and Ubi4 proteins, these loops must be the origin of the reduced solubility. At this point, it is not clear whether the aggregation of Ubi4-K is caused by interactions between the loops, or by interactions between the loops and the invariable regions of the Fn3 scaffold.
[0196] The Ubi4-K protein retained the global fold of Fn3, showing that this scaffold can accommodate a large number of mutations in the two loops tested. Though the stability of the Ubi4-K protein is significantly lower than that of the wild-type Fn3 protein, the Ubi4 protein still has a conformational stability comparable to those for small globular proteins. The use of a highly stable domain as a scaffold is clearly advantageous for introducing mutations without affecting the global fold of the scaffold. In addition, the GuHCl-induced unfolding of the Ubi4 protein is almost completely reversible. This allows the preparation of a correctly folded protein even when a Fn3 mutant is expressed in a misfolded form, as in inclusion bodies. The modest stability of Ubi4 in the conditions used for library screening indicates that Fn3 variants are folded on the phage surface. This suggests that a Fn3 clone is selected by its binding affinity in the folded form, not in a denatured form. Dickinson et al. proposed that Val 29 and Arg 30 in the BC loop stabilize Fn3. Val 29 makes contact with the hydrophobic core, and Arg 30 forms hydrogen bonds with Gly 52 and Val 75. In Ubi4-Fn3, Val 29 is replaced with Arg, while Arg 30 is conserved. The FG loop was also mutated in the library. This loop is flexible in the wild-type structure, and shows a large variation in length among human Fn3 domains (Main et al., 1992). These observations suggest that mutations in the FG loop may have less impact on stability. In addition, the N-terminal tail of Fn3 is adjacent to the molecular surface formed by the BC and FG loops ( FIGS. 1 and 17 ) and does not form a well-defined structure. Mutations in the N-terminal tail would not be expected to have strong detrimental effects on stability. Thus, residues in the N-terminal tail may be good sites for introducing additional mutations.
Example XVIII
NMR Spectroscopy of Ubi4-Fn3
[0197] Ubi4-Fn3 was dissolved in [ 2 H]-Gly HCl buffer (20 mM, pH 3.3) containing NaCl (300 mM) using an Amicon ultrafiltration unit. The final protein concentration was 1 mM. NMR experiments were performed on a Varian Unity INOVA 600 spectrometer equipped with a triple-resonance probe with pulsed field gradient. The probe temperature was set at 30° C. HSQC, TOCSY-HSQC and NOESY-HSQC spectra were recorded using published procedures (Kay et al., 1992; Mang et al., 1994). NMR spectra were processed and analyzed using the NMRPIPE and NMRVIEW software (Johnson & Blevins, 1994; Delaglio et al., 1995) on UNIX workstations. Sequence-specific resonance assignments were made using standard procedures (Wüthrich, 1986; Clore & Gronenbom, 1991). The assignments for wild-type Fn3 (Baron et al., 1992) were confirmed using a 15 N-labeled protein dissolved in sodium acetate buffer (50 mM, pH 4.6) at 30° C.
[0198] The three-dimensional structure of Ubi4-K was characterized using this heteronuclear NMR spectroscopy method. A high quality spectrum could be collected on a 1 mM solution of 15 N-labeled Ubi4 ( FIG. 17 a ) at low pH. The linewidth of amide peaks of Ubi4-K was similar to that of wild-type Fn3, suggesting that Ubi4-K is monomeric under the conditions used Complete assignments for backbone 1 H and 15 N nuclei were achieved using standard 1 H, 15 N double resonance techniques, except for a row of H is residues in the N-terminal (His) 6 tag. There were a few weak peaks in the HSQC spectrum which appeared to originate from a minor species containing the N-terminal Met residue. Mass spectroscopy analysis showed that a majority of Ubi4-K does not contain the N-terminal Met residue. FIG. 17 shows differences in 1 HN and 15 N chemical shifts between Ubi4-K and wild-type Fn3. Only small differences are observed in the chemical shifts, except for those in and near the mutated BC and FG loops. These results clearly indicate that Ubi4-K retains the global fold of Fn3, despite the extensive mutations in the two loops. A few residues in the N-terminal region, which is close to the two mutated loops, also exhibit significant chemical differences between the two proteins. An HSQC spectrum was also recorded on a 50 μM sample of Ubi4-K in TBS. The spectrum was similar to that collected at low pH, indicating that the global conformation of Ubi4 is maintained between pH 7.5 and 3.3.
[0199] The complete disclosure of all patents, patent documents and publications cited herein are incorporated by reference as if individually incorporated. The foregoing detailed description and examples have been given for clarity of understanding only. No unnecessary limitations are to be understood therefrom. The invention is not limited to the exact details shown and described for variations obvious to one skilled in the art will be included within the invention defined by the claims. | A fibronectin type III (Fn3) polypeptide monobody, a nucleic acid molecule encoding said monobody, and a variegated nucleic acid library encoding said monobody, are provided by the invention. Also provided are methods of preparing a Fn3 polypeptide monobody, and kits to perform said methods. Further provided is a method of identifying the amino acid sequence of a polypeptide molecule capable of binding to a specific binding partner (SBP) so as to form a polypeptide:SSP complex, and a method of identifying the amino acid sequence of a polypeptide molecule capable of catalyzing a chemical reaction with a catalyzed rate constant, k cat , and an uncatalyzed rate constant, k uncat , such that the ratio of k cat /k uncat is greater than 10. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority from Japanese Patent Application No. 2008-244234, filed Sep. 24, 2008, the contents of which are herein incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a pattern forming method, and in particularly to a pattern forming method forming a linear pattern on a surface of a substrate with an ink jet head.
2. Description of the Related Art
Japanese Patent Application Publication No. 2003-80694 discloses a method for ejecting a liquid containing a functional component onto a substrate by means of inkjet so as to form a functional film pattern, wherein the liquid is ejected onto the substrate with a film forming surface having a contact angle falling within a range from 30 degrees to 60 degrees in such a manner that the liquid overlaps with a range of 1% or more and 10% or less of the diameter on the substrate, thereby forming conducting layer wiring.
When a liquid is ejected by means of inkjet so as to form a line on a substrate which the ejected liquid does not penetrate through (does not permeate), a bulge (a bunch) may be made in a portion of the line or jaggies may be made rather than a line having a smoothly linear (in the shape of a straight line) contour, depending on the interval or the amount of the liquid (liquid droplets) ejected on the substrate.
The method disclosed in Japanese Patent Application Publication No. 2003-80694 tries to avoid the braking or short-circuit of a conducting film wire. However, in cases of a pattern forming apparatus of an inkjet type, the dot pitch varies according to the accuracy of the landing positions (ejection direction and ejection volume) of ink ejected from an inkjet head and the accuracy of the position of a conveyed substrate. Therefore, it is difficult for the method disclosed in Japanese Patent Application Publication No. 2003-80694 to form lines with a uniform width in stable fashion.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a pattern forming method based on an inkjet system to form (make) a line-shape pattern with uniform width in a stable fashion.
In order to attain an object described above, one aspect of the present invention is directed to a pattern forming method comprising the step of ejecting droplets of a liquid containing a functional component, from nozzles of an inkjet recording head onto a surface of a substrate in one direction in sequence so as to form a linear pattern on the surface of the substrate, wherein: the inkjet recording head is controlled in such a manner that
p ≤ π d 6 ( θ sin 2 θ - cos θ sin θ ) { tan θ 2 ( 3 + tan 2 θ 2 ) } - 2 3
is satisfied where d denotes a diameter of the droplets of the liquid before depositing on the surface of the substrate, θ denotes a contact angle of the droplets of the liquid with respect to the substrate, and p denotes a dot pitch of the droplets of the liquid that are adjacently deposited on the surface of the substrate, and the droplets of the liquid contain a volatile solvent with volume ratio not less than
[
1
-
6
p
(
θ
sin
2
θ
-
cos
θ
sin
θ
)
{
tan
θ
2
(
3
+
tan
2
θ
2
)
}
-
2
3
π
d
]
×
100
%
.
Desirably, time interval from ejection of one of the droplets of the liquid that are to be adjacently deposited on the surface of the substrate until ejection of another one of the droplets of the liquid that are to be adjacently deposited on the surface of the substrate, is set to be 1 millisecond or less.
Desirably, the pattern forming method further comprises the step of ejecting droplets of the liquid from the nozzles onto a preliminary area other than the substrate, preliminary to ejection of the droplets of the liquid onto the surface of the substrate from the nozzles, wherein the ejection of the droplets of the liquid onto the surface of the substrate to form the linear pattern is started within one second after ejection of the droplets of the liquid onto the preliminary area.
According to the present invention, the dot pitch and the volume ration of a volatile solvent of a liquid are controlled in accordance with the above formulas, and thereby occurrence of jaggies or bulges can be prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
The nature of this invention, as well as other objects and benefits thereof, will be explained in the following with reference to the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures and wherein:
FIG. 1 is an oblique perspective view illustrating a pattern forming device related to a first embodiment of the present invention;
FIG. 2 is a plan view illustrating a surface in which nozzles of a recording head are formed;
FIG. 3 is a cross-sectional diagram illustrating an ejection element;
FIG. 4 is a block diagram illustrating a control system of a pattern forming apparatus;
FIG. 5 is a diagram illustrating steps of a scanning control for making a pattern L by causing the recording head and a substrate to move relatively in an x direction;
FIGS. 6A and 6B are views (including cross-sectional diagrams and plan views) illustrating the changing state over time of liquid droplets ejected onto the surface of the substrate;
FIG. 7 is a plan view illustrating a positional example of a preliminary ejection region;
FIG. 8 is a plan view illustrating another positional example of the preliminary ejection region;
FIG. 9 is a plan view illustrating another positional example of the preliminary ejection region; and
FIG. 10 is a flowchart indicating steps for a pattern forming.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Desirable embodiments of a pattern forming method according to embodiments of the present invention are described below with reference to drawings.
Configuration of Pattern Forming Device
FIG. 1 is an oblique perspective view illustrating a pattern forming device related to a first embodiment of the present invention.
As illustrated in FIG. 1 , the pattern forming device (ink jet recording device) 10 of the present embodiment includes an ink jet head (referred to hereinbelow as “recording head”) 12 and a support plate 14 .
The recording head 12 is a line-type of recording head in which a plurality of nozzles 22 are aligned in the main scanning direction (y direction in FIG. 1 ).
A substrate 16 that is an object onto which a liquid is ejected from the recording head 12 , is placed on the support plate 14 . The support plate 14 is supported so as to maintain a constant clearance gap with the recording head 12 , and is capable of scanning (moving) in the sub-scanning direction (x direction in FIG. 1 ).
By causing the recording head 12 to eject liquid droplets while causing the support plate 14 to move in the x direction, the liquid can be deposited on the entire surface of the imaging region of the substrate 16 .
FIG. 2 is a plan view illustrating a surface where the nozzles of the recording head 12 are formed.
As illustrated in FIG. 2 , the recording head 12 has a structure in which ejection elements 20 (see FIG. 3 ), each having a nozzle 22 and a pressure chamber 24 , are arranged substantially equidistantly in the main scanning direction (y direction) substantially perpendicular to the sub-scanning direction (x direction).
A nozzle diameter of the recording head 12 is, for example, 35 μm and the distance between the centers of adjacent liquid droplets on the substrate 16 (nozzle pitch) is, for example, 254 μm (100 npi (nozzles per inch)). The recording head 12 has a jet-out period (ejection cycle) of 1 kHz, and droplets can be continuously jetted out at a head scanning (moving) rate of 0.1 msec.
FIG. 3 is a cross-sectional diagram illustrating an ejection element 20 .
The pressure chambers 24 provided correspondingly to the nozzles 22 have a substantially square shape in a plan view thereof. An outflow port leading to the corresponding nozzle 22 is provided in one inner corner on a diagonal line of each pressure chamber 24 , and a liquid supply port 26 leading to the corresponding pressure chamber 24 is provided in the other corner. In addition to the aforementioned square shape, the pressure chambers 24 can have a polygonal shape such as tetragonal shape (rhomboidal shape, rectangular shape), pentagonal shape, or hexagonal shape, and also round shape or elliptical shape.
As illustrated in FIG. 3 , the pressure chambers 24 of the ejection elements 20 are linked to a common channel 28 via the supply ports 26 . The common channel 28 is linked to a tank (not illustrated in the figure) that serves as a liquid supply source, and the liquid supplied from the tank is distributed and supplied to the pressure chambers 24 via the common channel 28 .
Piezoelectric elements 34 provided with individual electrodes 32 respectively are bonded to a pressure plate (oscillation plate (diaphragm) also serving as a common electrode) 30 constituting parts of the surfaces (top surface in FIG. 3 ) of the pressure chambers 24 . For example, a piezoelectric material such as lead zirconium titanate (PZT) or barium titanate can be used as a material for the piezoelectric elements 34 .
Where a drive signal is applied between an individual electrode 32 and the common electrode, the corresponding piezoelectric element 34 is deformed and the volume of the corresponding pressure chamber 24 changes. As a result, the pressure inside the pressure chamber 24 changes, thereby ejecting a droplet from the corresponding nozzle 22 . After the droplet has been ejected, the displacement of the piezoelectric element 34 returns to the original state, and the pressure chamber 24 is refilled with new liquid from the common channel 28 via the supply port 26 .
In the present embodiment, a system is employed by which ink is pressurized by deformation of the piezoelectric elements 34 , but actuators of other systems (for example, a thermal system) may be also employed.
FIG. 4 illustrates a block diagram illustrating a control system of the pattern forming device 10 .
The pattern forming device 10 includes a communications interface 40 , a system controller 42 , a memory 46 , a motor driver 48 , a heater driver 52 , an ejection control unit 56 , a buffer memory 58 and a head driver 60 .
The communications interface 40 functions as an interface unit receiving ejection date sent from a host computer 80 . As the communications interface 40 , USB (Universal Serial Bus), IEEE1394, Ethernet (registered trademark), wireless network, other serial networks, parallel interface such as Centronics may be used. Further, a buffer memory may be mounted on this portion in order to speed up the communications.
The system controller 42 includes a CPU (central processing unit) and the peripheral circuits, and functions as a control unit controlling each section of the pattern forming device 10 . This system controller 42 controls the communications with the host computer 80 , controls read-in and writing-in the memory 46 , generates control signals to control the motors 50 of the conveyance drive system and the heater 54 , and performs other control.
Control programs of the pattern forming device 10 are stored in a program storage unit 44 . The system controller 42 reads out various sorts of control programs stored in the program storage unit 44 and performs the read-out programs in a proper manner.
The memory 46 is a memory device used as a temporary storage area of date and a working area when the system controller 42 carries out various sorts of calculations. As the memory 46 , a memory formed from a semiconductor element, or a magnetic medium such as a hard disk may be used.
The motor 50 drives a driving system for driving at least one of the recording head 12 and the support plate 14 in FIG. 1 so as to cause the recording head 12 and the support plate 14 to move relatively. The motor driver 48 drives the motor in accordance with control commands from the system controller 42 .
The heater driver 52 drives the heater 54 in accordance with control signals from the system controller 42 . The heater 54 includes heaters for adjusting temperature provided on parts of the pattern forming device 10 .
The ejection date sent from the host computer 80 is sent into the pattern forming device 10 via the communications interface 40 , and is temporarily stored in the memory 46 .
The ejection control unit 56 has a signal processing function to carry out various processing and correction to generate signals for controlling the ejection from the ejection data stored in the memory 46 in accordance with the control by the system controller 42 , and supplies the generated print control signals (dot data) to the head driver 60 . Required signal processing is carried out in the ejection control unit 56 , and the ejection amount and the ejection timing of the liquid from the head 12 are controlled via the head driver 60 , on the basis of the ejection data.
The head driver 60 drives the piezoelectric elements 34 of the recording head 12 on the basis of the ejection data supplied from the ejection control unit 56 . The head driver 60 may include a feedback control system to keep constant drive conditions of the head.
The ejection control unit 56 is provided with a buffer memory 58 ; and ejection data, parameters, and other data are temporarily stored in the buffer memory 58 when the ejection data is processed in the ejection control unit 56 .
It is possible to use the buffer memory 58 as the memory 46 . It is also possible to integrate the ejection control unit 56 and the system controller 42 in such a manner that both the ejection control unit 56 and the system controller 42 are realized by one processor.
Although not illustrated in the drawings, the pattern forming apparatus 10 comprises a supply system for supplying liquid to the recording head 12 and a maintenance unit which carries out maintenance of the recording head 12 .
Liquid Ejection Conditions
FIG. 5 is a diagram illustrating a schematic view of a scanning control procedure when recording a pattern L by scanning (moving) the recording head 12 and the substrate 16 relatively in the x direction.
As illustrated in FIG. 5 , in the present embodiment, a linear (for example, a straight line) pattern L is described by ejecting a liquid (ink) formed by mixing a functional component (for example, silver nano-particles) in a volatile solvent (for example, water or tetradecane) while scanning (moving) the recording head 12 and the substrate 16 relatively in the x direction. In this case, if the interval (dot pitch p) between the liquid droplets D ejected onto the substrate 16 is large, then jaggies become liable to occur. Furthermore, if the ratio of the volatile solvent contained in the liquid is large, then bulges become liable to occur. Below, the conditions with respect to the dot pitch p and the ratio of solvent in the liquid in order to prevent the occurrence of jaggies and bulges are determined.
Liquid Ejection Condition 1 (Dot Pitch p)
FIGS. 6A and 6B are a diagram illustrating a schematic and plan view of temporal change in liquid droplets ejected onto the surface of a substrate 16 .
As illustrated in FIG. 6A , droplets D 1 eqm which have been ejected from the recording head 12 and have landed on the surface of the substrate 16 have a substantially round shape at the start of landing and makes contact with an adjacent droplet. As illustrated in FIG. 6B , each of the droplets D wets and spreads to form a pattern L.
Here, it is supposed that the substrate 16 is a medium into which the droplets D do not penetrate (permeate), and the volume of the droplets is the same before and after landing on the substrate 16 . Furthermore, it is supposed that the angle of contact θ (rad) of the droplet D with respect to the substrate 16 is uniform.
In this case, the ratio β eqm between the diameter d eqm (μm) of a droplet D 1 eqm after landing on the substrate 16 and the diameter d (μm) of the droplet D before landing (the rate of spreading) is expressed by Formula (1) below. Here, the diameter d is the diameter when the droplet D before landing is converted to a sphere.
β
eqm
=
d
eqm
d
=
2
{
(
tan
θ
2
)
(
3
+
tan
2
θ
2
)
}
-
1
3
Formula
(
1
)
If the width of the pattern L is taken as w (μm), then the cross-sectional surface area S 1 (μm 2 ) of the droplet D 2 eqm in FIG. 6B in a section taken in a plane parallel to the zy plane passing through the center of the droplet D 2 eqm is expressed by Formula (2) below.
S
1
=
1
4
w
2
(
θ
sin
2
θ
-
cos
θ
sin
θ
)
Formula
(
2
)
Therefore, if the distance (nozzle pitch) between the centers of adjacently positioned droplets on the substrate 16 is taken as p (μm), then the volume Va (μm 3 ) of the droplet D 2 eqm is expressed by Formula (3) below.
Va
=
1
4
w
2
p
(
θ
sin
2
θ
-
cos
θ
sin
θ
)
Formula
(
3
)
On the other hand, since the diameter of the droplet before landing is d, then the volume Vb (μm 3 ) of the droplet D before landing is expressed by Formula (4) below.
Vb
=
1
6
π
d
3
Formula
(
4
)
From Formula 1 above, the volume of the droplet D remains unchanged, before and after landing. If Va=Vb is solved with respect to the width w, then Formula (5) below is obtained.
w
=
2
π
d
3
3
p
(
θ
sin
2
θ
-
cos
θ
sin
θ
)
Formula
(
5
)
Here, since w≧d eqm =β eqm d, then if Formula (5) is solved by taking the dot pitch p as a variable, the conditional Formula (6) for the dot pitch p is obtained.
p
≤
2
π
d
3
β
eqm
2
(
θ
sin
2
θ
-
cos
θ
sin
θ
)
=
π
d
6
(
θ
sin
2
θ
-
cos
θ
sin
θ
)
{
tan
θ
2
(
3
+
tan
2
θ
2
)
}
-
2
3
Formula
(
6
)
By controlling the dot pitch p so as to satisfy the condition in Formula (6) above, it is possible to prevent the occurrence of raggedness (jaggies) in the outline of the pattern L.
Liquid Ejection Condition 2 (Condition Relating to Ratio of Solvent (Volatile Component) in Liquid)
Next, the condition relating to the ratio of the solvent (volatile component) in the liquid will be described. Here, the liquid ejected onto the substrate 16 is taken to be, for example, a liquid (ink) obtained by dispersing silver nano-particles in a solvent of water or tetradecane (both of which have volatile properties).
As described above, when a pattern L is described by ejecting liquid onto the substrate 16 , if the amount of solvent (liquid component) in the pattern L is too great with respect to the line width w, then bulges are liable to occur. In order to prevent the occurrence of bulges, the amount of solvent on the substrate 16 should be reduced to a level whereby bulges do not occur when the solvent is evaporated off after the droplet D has landed on the substrate 16 . More specifically, the amount of solvent is set in such a manner that the diameter d eqm (μm) of the droplet D after wetting and spreading on the substrate 16 and after the solvent has evaporated off is equal to the line width w (μm). If w=d eqm , then the volume V 1 (μm 3 ) of the droplet D 2 eqm after wetting and spreading and evaporation of the solvent is represented by Formula (7) below.
V
1
=
p
{
θ
(
d
eqm
2
sin
θ
)
2
-
d
eqm
2
cos
θ
4
sin
θ
}
Formula
(
7
)
On the other hand, since the diameter of the droplet before landing is d, then the volume V 2 (μm 3 ) of the droplet D before landing is expressed by Formula (8) below.
V
2
=
4
3
π
(
d
2
)
3
Formula
(
8
)
Consequently, the ratio of the volatile solvent contained in the liquid (volume ratio) {(V 2 −V 1 )/V 2 ×100(%)} is expressed by Formula (9) below.
V
2
-
V
1
V
2
×
100
%
=
[
1
-
p
{
θ
(
d
eqm
2
sin
θ
)
2
-
d
eqm
2
cos
θ
4
sin
θ
}
4
3
π
(
d
2
)
3
]
×
100
%
=
[
1
-
6
p
(
θ
sin
2
θ
-
cos
θ
sin
θ
)
{
tan
θ
2
(
3
+
tan
2
θ
2
)
}
-
2
3
π
d
]
×
100
%
Formula
(
9
)
By setting the ratio of the volume of volatile solvent in the liquid to a value equal to or greater than that expressed by Formula (9) above, it is possible to prevent the occurrence of bulging.
Liquid Ejection Condition 3 (Interval Between Droplet Ejection Timings)
Next, the interval between droplet ejection timings will be described. Table 1 indicates the stability of the line width w when lines were recorded at different values of the number of droplets D ejected per second (i.e. printing frequency), and different dot pitches, taking droplet diameter as d=26.0 (μm), d eqm =55.5 (μm) and the angle of contact as θ=30(°) (in other words, under conditions which satisfy Formulas (6) and (9) above).
TABLE 1
Printing
Frequency
Dot Pitch [μm]
[Hz]
20
30
40
50
10
Poor
Poor
Poor
Poor
1000
Good
Good
Average
Poor
10000
Good
Good
Good
Poor
In Table 1, a case where the line width w of the printed line is stable (for example, a case where the amount of variation in the line width w (for example, the difference between the maximum value and minimum value of the line width w per unit length) is less than a prescribed value) is indicated as “Good”, a case where the amount of variation in the line width w is equal to or greater than the prescribed value but the amount of variation is not as large as a “Poor” case is indicated as “Average”, and a case where the amount of variation in the line width w is greater than the maximum value of the amount of variation in an “Average” case is indicated as “Poor”. According to the experimental results in Table 1, if the printing frequency was equal to or greater than 1000 Hz, then the line width w was stable and results which are free of the occurrence of bulges and jaggies were obtained.
Consequently, the interval from printing the n th droplet until printing the (n+1) th droplet is set to be 1 millisecond or less. By adopting such an interval, it is possible to prevent the combination on the substrate 16 during printing of portions which are in a balanced state (a state where the droplets D have wet and spread and the shape of the droplets D is stable) and portions which are in an unbalanced state (a state during the wetting and spreading of the droplets D and before the shape of the droplets D has become stable). Consequently, a balanced state is achieved and it becomes possible to obtain recorded lines of uniform width, without the formation of large pools of droplets D in an unbalanced state or thickening of a portion of the pattern L.
Liquid Ejection Condition 4 (Preliminary Ejection)
Next, preliminary ejection before the start of printing will be described.
In a pattern forming apparatus of an inkjet type, if a state where ink is not ejected has continued for a prescribed period of time or longer, the solvent in the ink adhering to the vicinity of the nozzles 22 of the recording head 12 evaporates off, the density of the silver nano-particles of the ink becomes higher and the viscosity becomes higher. If this occurs, then when a piezoelectric element 34 (see FIG. 3 ) is operated, a liquid ejection error or ejection failure occurs.
Consequently, in the present embodiment, ink of high viscosity which is adhering to the vicinity of the nozzles 22 is removed by carrying out preliminary ejection (“dummy ejection”, “purging”, “spit ejection”) in order to eject ink onto a prescribed preliminary ejection region before the start of printing. Furthermore, by carrying out preliminary ejection also after the soiling on the nozzle surface has been wiped by a wiper (not illustrated) of a cleaning blade which is provided as a nozzle surface wiping device, infiltration of foreign matter into the nozzles due to the wiping operation of the wiper is prevented.
If the preliminary ejection described above is carried out, desirably, printing is started within one second after preliminary ejection. By this means, it is possible to print lines of a stable uniform width.
Carrying out preliminary ejection onto the substrate 16 may possibly cause problems in the product, and therefore it is desirable to provide a preliminary ejection region in the pattern forming apparatus 10 . In order to shorten the time period from the carrying out of preliminary ejection until the start of printing, it is desirable that the preliminary ejection region should be located in the whole of the periphery of the substrate 16 or the print start position ST.
FIG. 7 to FIG. 9 are plan diagrams illustrating examples of the positioning of the preliminary ejection region.
In the example illustrated in FIG. 7 , the recording head 12 is movable in the xy directions and a preliminary ejection region 100 is provided in a region surrounding the substrate 16 on the substrate 16 mounting surface of a support plate 14 .
When preliminary ejection is carried out, the perpendicular line L 1 of shortest length of lines connecting to the inner circumference of the preliminary ejection region 100 from the print start position (point) ST of the substrate 16 is selected. Preliminary ejection is carried out at a point (preliminary ejection position) PR on the line obtained by extending the vertical pattern L 1 toward the preliminary ejection region 100 side. The preliminary ejection position PR is set at a position where the distance between the preliminary ejection position PR and the substrate 16 is longer than the predicted radius of the droplet when the liquid ejected by preliminary ejection has landed on the preliminary ejection region 100 . Thereupon, after the end of preliminary ejection, the recording head 12 is moved to the printing start position ST following the perpendicular pattern L 1 . By this means, it is possible to shorten the time from the end of preliminary ejection until the start of printing at the printing start position ST.
In the examples illustrated in FIG. 8 and FIG. 9 , a preliminary ejection region 100 A is provided on either side of the substrate 16 . In the example illustrated in FIG. 8 , the recording head 12 is movable in the ±y direction and the substrate 16 is movable in the ±x direction. Furthermore, in the example illustrated in FIG. 9 , the recording head 12 is movable in the xy directions and the substrate 16 is movable in the +x direction.
In the examples illustrated in FIG. 8 and FIG. 9 , by setting the preliminary ejection similarly to FIG. 7 , it is possible to shorten the time period from the end of preliminary ejection until the start of printing at the printing start position ST.
It has been confirmed that the phenomenon of large swelling of a portion of the line occurs over a time scale of 2 to 8 seconds. Therefore, by controlling the heater 54 , or the like, to solidify the droplets D on the substrate 16 within one second after landing, it is also possible to prevent the occurrence of bulges.
Pattern Forming Procedure
Next, steps for pattern forming are described by referring to the flowchart in FIG. 10 .
Firstly, the system controller 42 obtains the co-ordinates of the printing start position ST on the substrate 16 and calculates the co-ordinates of the point where preliminary ejection is possible which is closest to the printing start position ST in the preliminary ejection region 100 (the preliminary ejection position PR). The system controller 42 outputs a control signal to the head driver 60 , thereby moving the recording head 12 to the preliminary ejection position PR (step S 10 ).
Next, preliminary ejection is carried out (step S 12 ), the recording head 12 is moved to the printing start position ST (step S 14 ) and printing is started (step S 16 ). Thereupon, printing of a pattern L is carried out using a dot pitch which satisfies the condition in Formula (6) above and at a droplet ejection interval of 1 millisecond or less (step S 18 ).
Here, the system controller 42 controls the recording head 12 and the support plate 14 in such a manner that the processes from step S 12 to step S 16 are completed within one second.
According to the present embodiment, it is possible to prevent the occurrence of jaggies and bulges by controlling the dot pitch p so as to satisfy the condition in Formula (6) above, by setting the ratio of the volume of volatile solvent in the liquid to a value equal to or greater than that expressed by Formula (9) above, and by setting the droplet ejection time interval and the time interval from preliminary ejection to a prescribed value or less.
It should be understood that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the invention is to cover all modifications, alternate constructions and equivalents falling within the spirit and scope of the invention as expressed in the appended claims. | A pattern forming method includes the step of ejecting droplets of a liquid containing a functional component, from nozzles of an inkjet recording head onto a surface of a substrate in one direction in sequence so as to form a linear pattern on the surface of the substrate, wherein: the inkjet recording head is controlled in such a manner that
p ≤ π d 6 ( θ sin 2 θ - cos θ sin θ ) { tan θ 2 ( 3 + tan 2 θ 2 ) } - 2 3
is satisfied where d denotes a diameter of the droplets of the liquid before depositing on the surface of the substrate, θ denotes a contact angle of the droplets of the liquid with respect to the substrate, and p denotes a dot pitch of the droplets of the liquid that are adjacently deposited on the surface of the substrate, and the droplets of the liquid contain a volatile solvent with volume ratio not less than
[
1
-
6
p
(
θ
sin
2
θ
-
cos
θ
sin
θ
)
{
tan
θ
2
(
3
+
tan
2
θ
2
)
}
-
2
3
π
d
]
×
100
%
. | 1 |
BACKGROUND OF THE INVENTION
The current invention generally relates to an apparatus for detecting force or pressure applied to the bottom of a foot and lower extremity, and more particularly, to an apparatus for detecting the application of a predetermined threshold amount of force or pressure applied to a cast, boot, shoe, mat, insole, sock, or other lower extremity immobilization or protective device, where the predetermined threshold relates to a pressure threshold that could be deleterious or harmful if exceeded (including situations where patients are recovering from a bony fracture, tendon injury, and recent lower extremity surgery).
A recurring problem with recovery from an injury in a lower extremity, such as a leg or foot, is the risk of secondary injuries or trauma. As patients begin recovering, they naturally want to resume their typical routine, and in many cases the increased activity is part of their rehabilitation regime. However, even if a patient is generally aware and exercising care not to place undue pressure on a recovering extremity, it is difficult for most people to remember how much a given threshold weight feels like when using their legs, and even the best of patients find it difficult to remain conscious of the need to avoid more than that threshold, avoid missteps or loss of balance, or the like, all events which could lead to too much pressure being exerted.
To minimize the risk of new injury or trauma, a variety of alert devices have been developed to assist in warning patients as too much weight is being exerted. Despite the extensive development of such devices, they continue to exhibit certain disadvantages. For example, their designs are: (1) too complex, (2) too costly, (3) and fail to fully record and document all incidents in which too much pressure has been exerted. Thus, there exists a continuing need for the development of new and improved, easier to use and inexpensive devices for the detection of force or pressure applied to a cast, boot, shoe, mat, sock, insole, or other lower extremity immobilization or protective device.
SUMMARY OF THE INVENTION
Recognizing the need for the development of improved pressure monitoring under or within, for example, a cast, boot, shoe, mat, sock, insole or other lower extremity immobilization or protective device, the present invention is generally directed to satisfying the needs set forth above and overcoming these and other disadvantages with prior art devices and to providing a device that is comfortable or at least not uncomfortable when used.
An illustrative, but not inclusive, listing of advantages that may now be realized in various exemplary embodiments of the present invention include: providing a pressure detection device that is simple to construct and use and whose manufacturing costs my be kept to a minimum; providing a pressure detection device that will detect that a threshold of pressure has been applied to the bottom of a cast, boot, shoe, or other lower extremity immobilization or protective device; and providing a pressure detection device that will alert both the patient and health care provider detect that pressure has been applied to the bottom of a cast, boot, shoe, or other lower extremity immobilization or protective device, such that, for instance: (1) appropriate counseling may be undertaken, (2) further instruction or physical therapy can be provided to the patient, or (3) the protective device may be appropriately augmented.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A diagrammatically illustrates a bottom and side view of a first exemplary embodiment of the present invention.
FIG. 1B diagrammatically illustrates a bottom and side view of a second exemplary embodiment of the present invention.
FIG. 1C diagrammatically illustrates a bottom and side view of a third exemplary embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following, FIGS. 1A-1C diagrammatically illustrate various embodiments of the present invention. These figures respectively depict illustrative bottom and right side cross-sectional views each of different passive foot pressure detection devices in accordance with embodiments of the present invention. In this and the other figures, the symbol “•” is used to schematically represent pressure sensitive chambers.
In accordance with embodiments of the present invention, the pressure sensitive chambers are preferably designed to burst or otherwise release their contents at a known, e.g., pre-determined force or weight. As will be recognized by those skilled in the art, the pressure that the chambers burst depends upon the material of chambers and, for example, the thickness of the chamber walls. These parameters are well known to those skilled in the art, and are therefore not discussed herein.
The pressure sensitive chambers may be filled with air or other gases, a suitable liquid, or semi-liquid or releasable solids (e.g., a fine granular solid) material; either dyed or undyed. They can be filled with miniature or sub microscopic particulate transmitters that permit continuous or immediate identification of their location in space.
The pressure sensitive chambers themselves may be made from any appropriate material, such as plastics, and will typically be the same as the material of the base. The base material may be of any desired shape and thickness, e.g., up to several mm if serving as an insert. Or, for example, the base material need be no thicker than needed to serve as an adhesive tape. In the adhesive example, the adhesive can be on one side and the pressure sensitive chambers (e.g., micro-bubbles) formed onto the opposite side. The adhesive or attaching materials, when used, could be any suitable adhesive for attachment to a lower extremity device, such as a cast, a boot, a shoe, or other lower extremity immobilization or protective device (“LED”). The pressure sensitive device can be fabricated of any suitable material, such as, for example, plastic, polymer, cloth, foam, cork, rubber, natural or synthetic material, or some combination thereof of these materials. In some embodiment it may be desirable to select a material for the pressure sensitive chambers that is temperature and/or moisture resistant so that the pressure sensitive chambers do not spontaneous rupture prior to application of the predetermined force or pressure and so that the mechanical properties of the device are not altered upon exposure to the environment. The base can be constructed of the same material if desired.
While the present embodiments are preferably formed for lower extremity devices, the present invention is not limited to such use, and can be utilized in any manner where excessive force is desired to be monitored in connection with any limb, appendage or body part that when in contact with the environment creates a mechanical pressure.
In the exemplary embodiments, the device is preferably flat and may or may not have adhesive or some other method for securing the device such as, but not limited too, clasps, Velcro, etc, on the side opposite of the pressure sensitive chambers. Other ways of attaching the device may be used, such as adhesive tabs. Or course, in some situations, it is not necessary to secure the device.
In the exemplary embodiments, the shape of the device approximates the shape of the human foot in the transverse plane. However, the device may also be made in other shapes, including, but not limited to, oval, rectangular, circular, square, and eccentric shapes, or any limb, appendage or body part that when in contact with the environment creates a mechanical pressure desired to be monitored.
Referring to FIG. 1A , this figure diagrammatically illustrates a bottom and side view of a first exemplary embodiment of the present invention. In FIG. 1 , there are two regions/clusters of pressure sensitive chambers (a); one located in the heel region of the base (b) and the other in the forefoot region of the base (b). In this case, a single pressure detection device (“PDD”) can serve as an insert, e.g., formed to fit in shoes or other LED's without sliding, or as an externally attachable unit.
FIG. 1B diagrammatically illustrates a bottom and side view of a second exemplary embodiment of the present invention. In FIG. 1B , there are several regions/clusters of pressure sensitive chambers (a) distributed over the base (b) of the pressure detection device. The distribution of the pressure sensitive chambers (a) need not be uniform as shown in the example of FIG. 1B .
FIG. 1C diagrammatically illustrates a bottom and side view of a third exemplary embodiment of the present invention. In FIG. 1C , the pressure sensitive chambers (a) are distributed in a non-clustered fashion over the entire base (b) of the pressure sensitive device. Again, as in the exemplary embodiment of FIG. 1B , the distribution of the pressure sensitive chambers need not be uniform as shown in FIG. 1C .
In accordance with embodiments of the present invention, the pressure sensitive chambers can be arranged in rows and/or columns such that a set amount of force or pressure will burst substantially all the pressure sensitive chambers of one row, column, or cluster.
In accordance with one preferred embodiment of the present invention, a pressure detection device can be applied to the bottom of a cast, boot, shoe, or other lower extremity immobilization or protective device by, for example, an adhesive applied to the superior aspect of the PDD. The PDD comprises a single pressure sensitive chamber or set of pressure sensitive chambers, fixedly attached to a backing material or base, and with the adhesive on a first side of the material. When the adhesive is exposed or activated, a user (e.g., a medical doctor) applies the PDD to a desired region of the LED for monitoring pressure in that region. Multiple PDDs can be applied to different regions of the LED, allowing detection of excess pressure at each of the regions.
Further, the cell(s) of each PDD have a predetermined pressure threshold, which if exceeded leads to a destructive (e.g., bursting) or non-destructive (e.g., release via a valve, that can be refilled) change in the cell(s), which readily indicates that the threshold pressure was exceeded. A destructive release is preferred, as being the easiest and most economical form of PDD to make and maintain. If the PDDs are formed in the shape of strips (e.g., FIG. 2 ), all pressure sensitive chambers in a given strip can be conveniently designed to burst at the same pressure threshold, and different strips having different pressure thresholds can be designated by any convenient manner (e.g., color or alphanumeric coding on the strip). Alternatively, a given strip can be utilized that has pressure sensitive chambers with multiple thresholds. For example, a first threshold can be used to warn the patient visibly or by giving a popping noise, that he/she is using pressure close to an unsafe threshold, and pressure sensitive chambers with a second threshold can be used that burst when an unsafe threshold is exceeded. As will be recognized by those skilled in the art, the present invention contemplates that the pressure sensitive chambers be in the base, such as with material that has the chambers formed in the base such as, for example a suitably strengthened form of bubble wrap, to provide the popping, or on the base such as shown in the figures. The present invention is not limited to any particular structure or arrangement of the pressure sensitive chambers.
In another embodiment of the present invention, the pressure detection device may be inserted within some portion a cast, boot, shoe, mat, sock, insole, or other lower extremity immobilization or protective device.
In another embodiment of the present invention, the pressure detection device may be encased in a protective envelope consisting of a material that will protect the individual chambers from abrasive wear.
Alternatively, in another embodiment of the present invention, the pressure detection device may be covered with or positioned adjacent to an absorbent material or adsorbent material. Such materials can be selected, as known to those skilled in the art, to exhibit the efflux of the contents of the burst pressure sensitive chamber or chambers.
Of course, one skilled in the art will appreciate how a variety of alternatives are possible for the individual elements, and their arrangement, described above, while still falling within the spirit of the invention. Thus, for example, the pressure sensitive chambers may be any commercially available bursting cell. Examples of suitable base materials have been given above, and one skilled in the art will appreciate that a variety of different PDD(s) may be used with different LEDs, the particular selection being a matter of design choice. Any convenient material (adhesives, tapes, velcro patches, heat sealing, etc.) or process may be used to help fix the position of the pressure sensitive chambers of the PDD so they are maintained proximate the desired region of the LED/foot when worn. Alternatively, part of the attachment mechanism for the PDD/pressure sensitive chambers (e.g., the base of a 2-part velcro-style patch) can be formed as an part of a regular or specialized LED or LED insert if desired, already appropriately positioned when forming the LED.
While the above describes several embodiments of the invention used primarily in connection with an adjustable cell system in treating positional hindfoot disorder, those skilled in the art will appreciate that there are a number of alternatives, based on system design choices and choice of protocol options, and extensions that still fall within the spirit of my invention. Thus, it is to be understood that the invention is not limited to the embodiments described above, and that in light of the present disclosure, various other embodiments and applications should be apparent to persons skilled in the art. Accordingly, it is intended that the invention not be limited to the specific illustrative embodiments. | According to a first embodiment of our invention, a monitoring device is placed above, within, or on the bottom of a cast, boot, shoe, or other lower extremity immobilization or protective device, and has one or more single or cluster of pressure sensitive chambers designed to burst at a predetermined force or weight. The pressure sensitive chambers may be filled with air, liquid, semi-liquid, or particulate material. Once properly positioned, the device serves to detect and alert one or more individuals to the fact that weight-bearing has occurred and/or that a certain amount of force has been transmitted across the bottom or other portion of the cast, boot, shoe, mat, sock, insole, or lower extremity immobilization or protective device in a setting where such pressure could be deleterious or harmful (including situations where patients are recovering from a bony fracture, tendon injury, and recent lower extremity surgery). | 0 |
BACKGROUND OF THE INVENTION
This invention relates to the gas jet treatment of multifilament yarns and is more particularly concerned with the cleaning of deposits from apparatus employed for gas jet yarn treatment.
Continuous multifilament synthetic yarns are treated with gas jet apparatus in various yarn treatment processes such as texturing to increase the bulkiness of the yarn and interlacing to provide adequate handling characteristics to the yarn without the need for the introduction of twist to the yarn. Typically, apparatus for such gas jet treatment processes employs a pressurized gas such as air which is supplied to a jet device with a yarn treatment zone including at least one orifice which forms and directs a stream of air into the treatment zone. The yarn is conveyed through the treatment zone while being positioned with respect to the air stream to achieve the desired treatment.
In such apparatus, the flow pattern of the air in the treatment zone and the position of the yarns is usually critical to achieve the desired effect uniformly as the yarn is treated. However, deposits tend to build up on surfaces in the treatment zone which can affect the yarn treatment process. Typically, these deposits are gel-like and are composed of yarn finish solids, titanium dioxide, polymer skins and trimer which are blown off the yarns being treated. This is particularly a problem in interlace jets of the type disclosed in U.S. Pat. No. Re. No. 29,285. Such jets are provided by a number of spaced-apart, stacked ceramic plates resembling "tombstones" which have jets on one side surface and the opposite side of the plate serves as a striker surface for the jets of an adjacent plate. Yarns to be interlaced are passed in the slots between the plates and are guided by positioning pins past the jets. While a plastic comb-like device has been used to clean such apparatus, manual cleaning has not been found to be effective due to the size of the slots and the obstruction provided by the positioning pins, particularly since even small deposits left on surfaces in the treatment zone can result in non-uniform interlacing.
SUMMARY OF THE INVENTION
In accordance with the invention, there is provided an improved apparatus for gas jet treatment of moving, continuous multifilament synthetic yarns and a method for cleaning gas jet treatment apparatus. In accordance with the invention, a pressurized gas source for the apparatus is selectively disconnected and reconnected to a conduit which supplies a gas jet orifice in a yarn treatment zone. A pressurized liquid is supplied to the conduit when the gas source is disconnected. The liquid is directed forcefully from the orifice into the yarn treatment zone to remove deposits on surfaces in the yarn treatment zone which form during treatment of the yarns.
In accordance with a preferred form of the present invention, the pressurized gas is at a higher pressure than the pressurized liquid and is reconnected to the conduit with the conduit filled with the liquid so that the pressurized gas acts initially to increase the pressure of the liquid in the conduit and thereby increase the force of the liquid being directed from the orifice and then to clear the liquid from the conduit and the orifice to restore the system to normal operation.
The method and apparatus of the invention are particularly suitable for use with interlacing jets or other jet device which have small or obstructed treatment zones. Cleaning can be performed without any disassembly of the apparatus and while the yarn is running such as during doffing and no downtime is necessary. Moreover, no loss of product results from cleaning during this period since such yarn is normally discarded or separated from the standard product during doffing.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be understood from the following detailed description illustrating a preferred embodiment of the invention which follows, reference being made to the accompanying drawings in which:
FIG. 1 is a schematic view of apparatus for the interlacing of moving, continuous multifilament synthetic yarns in accordance with the present invention including a gas jet treatment device shown with an enclosing cover removed; and
FIG. 2 is a side cross-sectional view of the gas jet treatment device employed in the apparatus of FIG. 1.
DETAILED DESCRIPTION
Referring now to the drawings in which like reference characters designate like or corresponding parts in FIGS. 1 and 2, FIG. 1 illustrates a preferred embodiment of apparatus 10 for the gas jet treatment of moving, continuous multifilament yarns in accordance with the present invention. Apparatus 10 includes a gas jet device 12 which provides interlacing to the four yarn threadlines 14 originating at spinning equipment (not shown) and being conveyed through the gas jet device 12. Subsequent to interlacing, the yarns are wound onto bobbins (not shown).
The gas jet device 12 provides a yarn treatment zone for each threadline in which a stream of gas such as air is employed to effect a controlled degree of entanglement or interlacing of the yarns as it moves through the zone. The gas jet device 12 depicted is of the type disclosed in U.S. Pat. Reissue No. 29,285 and U.S. Pat. No. 3,115,691, which are incorporated herein by reference. As in U.S. Pat. Re. No. 29,285, the yarn treatment zones are within slots provided by the facing surfaces of stacked, ceramic plates ("tombstones") 16 which are mounted in a spaced-apart parallel arrangement on a base 18 and the yarns run through the slots for interlacing. As is illustrated in FIG. 2, two orifices 20 in one side surface of the plates 16 provide converging streams of air directed towards the yarn in a slot. The orifices are supplied with compressed air from compressed air source 22, typically at between 35 and 95 psi depending on the desired level of interlace, by means of conduit 23 which extends from the source into the base 18 and through the plates 16. Air streams directed from the orifices 20 impinge upon the yarn and the surface of an adjacent plate 16 which serves as a striker surface during the interlacing process. For proper positioning of the yarns in relation to the air streams during interlacing, a guide pin 19 is provided directly adjacent the plates 16 above and below the slots. As shown in FIG. 2, a cover 24 encloses the area around the plates 16 and an exhaust duct 25 connected to a vacuum source 26 exhausts air from this enclosed area.
Referring again to FIG. 1, the apparatus 10 includes a liquid supply system 27 for providing liquid for cleaning one or a number of gas jet devices. Preferably, heated water is used for cleaning in accordance with the invention with water temperatures of between about 20° and about 100° C. being suitable but temperatures of between about 80° and about 95° C. are generally more effective and are preferred. Additives such as surfactants can be added to the water if desired. When the liquid is heated water, the liquid supply water system 27 includes a heated water tank 28 including a heating element and thermostatic control circuit illustrated schematically and identified as 30 and 32, respectively. The heated water tank 28 is connected to a water source 34 having a water level control circuit 36 with an appropriate solenoid valve 38 and level detector 40 so that the tank level is maintained relatively constant. Supply and return lines 42 and 43, respectively, are connected to the tank 28 to supply water for cleaning as will be described in more detail hereinafter. In order to maintain a uniform temperature of water in the tank and in the supply and return lines 42 and 43, a pump 44 circulates heated water from the tank to the supply line 42 and back to the tank by way of the return line 43. In addition, the length of any connecting lines from the supply line 42 to conduit 23 should be sufficiently short as will become apparent hereinafter so that there is not a large amount of cooler water held in such line.
For cleaning of the surfaces of the treatment zone of the gas jet device 12 in accordance with the invention, the compressed air source 22 is disconnected from the gas jet device 12 and the water is supplied instead of air so that it is directed from the orifices 20 to clean deposits from the surfaces within the treatment zone. In the preferred embodiment depicted, the air is supplied to conduit 22 through a normally open solenoid-operated valve 46. The water is connected to the conduit 22 at tee 48 with the flow of water being controlled by normally closed solenoid-operated valve 50. For actuation of the valves to begin a cleaning cycle with an air disconnect period of predetermined length, a time delay switch controlling an appropriate voltage source 54 acts to simultaneously close the normally open solenoid-operated valve 46 to shut off the compressed air and opens the normally closed solenoid-operated valve 50 to allow the flow of water into the conduit 22 for such predetermined time period.
The water can be supplied to the conduit 23 at a substantially lower pressure (e.g., 4.0 psi) than the normal interlace air provided the time delay switch keeps the normally closed solenoid-operated valve 50 open for a sufficient time for the water to fill the conduit extending from the valve 50 to the gas jet device 12. When the disconnect period is completed, the time delay switch causes the valve 50 to return to its normally closed position and the solenoid-operated valve 46 to return to its normally open position. When the pressure of the water is less than the pressure of the normal interlacing gas, the air pressure acts to increase the pressure of the liquid in the conduit. Liquid remaining in the conduit 22 is thus forced by the air pressure through the orifices 20 at a very high velocity which causes it to strike against surfaces in the treatment zone in a turbulent fashion to remove deposits from the surfaces. In addition, the air expels and clears the water from the conduit 23 and orifices 20 to restore the system to its normal condition. The exhaust duct 24 acts to carry the liquid and gel particles away from the area enclosed within the cover 19. When water heated to about 90° C. is employed, it has been found that, for example, approximately one pint of water is suitable for cleaning a jet device of the type depicted in FIGS. 1 and 2 having four threadlines.
The invention is most suitably employed during doffing when the yarns are being drawn into a sucker gun that carries the yarn into a waste container or otherwise separates the yarn from the standard product. For the embodiment depicted, the operator activates the cleaning cycle of the apparatus 10 by actuating the time delay switch 52 before new bobbins are placed on the machine. Cleaning thus takes place without the normal product being adversely affected and without disassembly or manual cleaning of the gas jet device 12. The apparatus is effectively cleaned in accordance with the invention, particularly surfaces that are obstructed from view such as by the guide pins which are in close proximity to the orifices 20 in the gas jet device.
While a preferred embodiment has been shown and described in the foregoing detailed description, it will be understood that the invention is capable of numerous modifications, rearrangements and substitution of parts without departing from the spirit of the invention as set forth in the appended claims. | Apparatus for gas jet treatment of moving, continuous multifilament synthetic yarn and a method for cleaning gas jet treatment apparatus are disclosed. A pressurized gas source for the apparatus is selectively disconnected and reconnected to a conduit which supplies a gas jet orifice in a yarn treatment zone. A pressurized liquid is supplied to the conduit when the gas source is disconnected. The liquid is directed forcefully from the orifice into the yarn treatment zone to remove deposits which form during treatment of the yarns. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to longwall mining in general.
More particularly, the invention relates to walking mine supports, and specifically to devices of this type which support the transitional area between road (gallery) and face.
2. The Prior Art
Longwall mining is well known. A review of the techniques employed and the equipment used may be found in U.S. Bureau of Mines Information Circular 8740, to which reference may be had for background information.
Basically, coal-mining equipment in longwall mining moves in a roadway (gallery) along a mine face from which coal is removed and transported away along the roadway. The roadway is supported by longitudinally spaced stationary supports each having uprights at opposite sides of the roadway and a lintel-type roof shield. The coal at the face is often so located that it must be removed by undercutting the face, i.e. by removing coal along the lower part of the face which leaves an overhang. This overhang, including the part of the face which merges with the roof of the adjacent roadway, must be supported against collapse. Also, since during passage of the coal-mining equipment the uprights of the stationary supports must be temporarily removed at the mine-face side of the roadway, the transitional area between roadway and face must similarily be supported by auxiliary supporting equipment.
For purposes of such support it is known to provide auxiliary supporting equipment which, heretofore, was a type that could be clamped, bolted or otherwise connected to the roadway supports. This equipment includes e.g. supporting shields and other elements which are braced from below by pit props. As coal removal progresses along the mine face, this equipment must frequently be disassembled, moved along the mine face to new locations and be reassembled. Given the relative frequency of such moves and the relatively large member of components involved in assembly and disassembly, it is clear that such operation are time-consuming and highly labor-intensive. Moreover, the frequent moves tend to change the equilibrium of the overburden so that disassembly and reassembly of the equipment usually requires the ability to make on-the-spot improvisation to accommodate for unexpected or changing conditions. This, in turn, means that the operations must be carried out by skilled miners, rather than by auxiliary personnel, and makes the whole procedure even more costly. In addition, damage to the various components, as well as to the coal-mining and coal-conveying equipment and to the roadway supporting equipment, is almost unavoidable. This is costly and, in the case of damage to the roadway supports, makes it even more difficult to carry out the assembly and disassembly operations.
The seam area of the face adjacent the roadway (i.e. the aforementioned transitional area) is also the area in which the drive equipment for the coal-mining and coal-conveying machines is located. This is the reason for the need to remove the stationary uprights while this equipment passes through. Because of this it has heretofore been customary to temporarily support this transitional area by means of individual hydraulic pit props which, in effect, define a kind of travelling buffer zone between the face and the roadway supports. The term "travelling" here denotes the fact that after the mining equipment has passed a given location, the pit props are moved along with it and in the vacated location the stationary uprights are reinstalled. Again, the release and resetting of these pit-props is carried out manually. Aside from the cost and the loss of time involved, the setting of these props (and the effectiveness of support offered by them) is directly dependent on the skill and care of the miners who are entrusted with this job. Any human error thus necessarily increases the danger of cave-ins. Also, the frequent removal of the props tends to cause loosening of the rock strata of the overburden in the transitional area between face and roadway.
A proposal has been made to provide a supporting arrangement for this transitional area which was to be coupled to and move with a face support and a walking roadway support. However, this could not be employed in practice because severe damage was constantly being sustained and also because it was incapable of accommodating itself to the constantly changing conditions of the surrounding strata.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to overcome the disadvantages of the prior art.
A more particular object is to provide a walking mine support which avoids these disadvantages and capable of providing requisite support for the face at all times, as well as being readily able to cooperate with a seam support while allowing for the possibility that both supports may be advancing at different times and/or rates.
In pursuance of these objects, and of still others which will become apparent hereafter, one aspect of the invention resides in a walking mine support of the type under discussion. Briefly stated, this support may comprise a walking roadway support unit adapted to support at least the roof of the roadway and adapted to advance lengthwise of the latter; a walking face gallery support unit adapted to support the roof of the face gallery and also adapted to advance lengthwise of the roadway; and at least one form-pivot coupling connecting the units with one another and comprising coupling members which are tiltable about mutually inclined axes extending lengthwise of and transverse to the elongation of the roadway, respectively.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a vertical section through the transition area between a mine roadway and a mine face, showing a mine support according to the invention in an endview;
FIG. 2 is a plan view of FIG. 1 as seen from the line II--II and partly shown in section; and
FIG. 3 is an enlarged detail view, showing a coupling used in the embodiment of FIGS. 1 and 2.
DESCRIPTION OF PREFERRED EMBODIMENTS
The reference numeral 2 in FIG. 1 designates a roadway (i.e. main gallery) extending substantially normal to the plane of FIG. 1. A face gallery 1 extends substantially at right angles to the roadway 2 and leads to the not-illustrated actual mine face. The roadway 2 is supported against cave-in by a plurality of longitudinally spaced stationary supports of the door-frame type, i.e. having two lateral uprights and a lintel shield 3. For simplicity, only the shield 3 of one of these stationary supports is shown in FIG. 1.
As the mining equipment travels along the face gallery 1 (i.e. lengthwise of the roadway 2) the not-illustrated upright stationary supports holding the shields 3 must be removed ahead of it so as not to interfere with its operation; they are reinstalled after the equipment has passed. While they are absent the shields 3 (and hence the overburden) must be supported by auxiliary supporting equipment, e.g. a travelling mine support unit 4 which is shown in FIGS. 1 and 2 as having two frames 5 and 6. These frames are connected with hydraulic rams which alternately move one of the frames (by pushing or pulling, as the case may be) along the roadway 2 while the other frame bears against the shields 3 and thus acts as a bearing for the rams 7. Preferably, such rams 7 are provided in the region of the floor beams 8 and of the roof beams 9 of the unit 4. Additional rams 10 to serve to shift the frames 5 and 6 transversely of the roadway 2 relative to one another. Further, each of the frames 5, 6 is also provided with devices 11 which compensate for gaps between the roof beams 9 and the shields 3, e.g. if the roof beams 9 cannot be extended sufficiently high to bear against the shields. To support the mine face area 15 above the face gallery 1 through which coal is being removed, the frames additionally have lateral shields 14 which can be pressed against the face area 15 by hydraulic rams 12 with which they are connected via appropriate linkages 13.
Extending along the transitional area between face gallery 1 and roadway 2, i.e. in a position to support the undercut resulting from the coal-mining operation in the coal seam, is a seam support unit 16. It has a roof shield 17 and a floor beam 18 which are connected by hydraulic rams 19 via which they can be urged apart, i.e. the shield 17 can be urged upwardly against the roof of the overhang. The rams 19 are arranged in V-formation, in direction transversely to as well as longitudinally of, the face gallery 1. One or more additional ones of the units 16 may be arranged in the gallery 1 inwardly (i.e. in FIG. 1 to the right) of the illustrated unit 16, so as to bridge the distance to the actual mine-face supports (not shown).
In accordance with the invention, and as is evident from a comparison of FIGS. 1 and 2, the unit 4 and the unit 16 are connected with one another by two sequentially arranged four-pivot couplings 20 (see also FIG. 3). These couplings 20 are each composed of two parallel plates 21, two parallel plates 22 and a plate-shaped connector 23. The plates are pivoted via a bolt or pin 24 to a bearing bracket 25 which in turn is pivotally connected with a bearing 27 on the floor beam 8 of the frame 6, by means of a bolt or pin 26 extending lengthwise of the roadway 2. One end of the respective connector 23 is pivoted to the plates 21, 22 and the other end is connected to a bearing bracket 29 via a bolt or pin 28. Bracket 29 is in turn pivotably connected to a bracket 31 on the shield 17 of the unit 16, via a bolt or pin 30 extending lengthwise of the roadway 2.
Accordingly, the components of the couplings 20 have the ability to pivot in direction lengthwise of the roadway 2, as well as to pivot in direction transversely thereto and with reference to both the unit 4 and the unit 16.
Hydraulic rams 32 serve to reinforce and also to displace the couplings 20. For this purpose the rams 32 extend between the plates 21, 22; they are pivoted to the upper plates 22 at 32a and at 32b to bearing brackets 33. One of the latter is pivotable relative to a bearing 35 on the floor beam 8 of the frame 6, via a bolt or pin 34 which extends lengthwise of the roadway 2. The other bracket 33, namely the one associated with the coupling 20 which is leading in the direction of support advancement (i.e. lengthwise of roadway 2), is pivoted to the bracket 27. The pivot axes of the bolt 26 and 34 coincide with one another.
The unit 16 may be so connected with another similar unit 16 that its floor beam can be shifted from the latter; e.g. a hydraulic ram may connect these units 16 so that one can be pushed or pulled by the ram while the other unit acts as an anchor, and vice versa.
The most important consideration is the specific disclosed arrangement of the couplings 20 since the planes of tilting movement of these couplings extend--according to the invention--in the longitudinal direction of the roadway 2, due to the fact that the pivot axes of the individual plates extend normal to this direction. This permits independent displacement of the unit 16 relative to the unit 4, and vice versa. In addition, it assures that the rather substantial forces resulting from forward movement of the units, especially of the unit 16, are properly absorbed and transmitted to that one of the units which at the particular time serves as the anchor for the moving unit. It is important that the invention makes it possible for the equipment to accommodate itself to variation in spacing and to changes in height, especially of the unit 16. Of course, it goes without saying that instead of two of the couplings 20 it may be possible to use only one or more than two, depending upon conditions in any given application. It will also be understood that the couplings 20 need not necessarily be connected between the roof shield of the unit 16 and the floor beam of the unit 4, although this has been found to be advantageous since it permits maximum freedom in the manipulation of the units 4, 16 relative to one another. The couplings 20 need not necessarily have the illustrated sets of parallel spaced plates 21, 22, although this is advantageous because it permits the rams 32 to be located in the clearance between these plates where they require no additional space and are relatively well protected against damage.
The advantage of providing the couplings 20 with the rams 32 (which could be omitted) is that it permits the roof shield 17 of the unit 16 to be pressed positively and accurately against the roof shield of a support unit (not shown) which is located adjacent to it in direction inwardly of the face gallery. This means that when the unit 16 must be advanced (i.e. "walk"), its floor beams can be lifted and will have much less frictional contact with the floor as they are advanced.
Instead of having the frames 5, 6 arranged adjacent to each other, they may also be nested one inside the other. The wall shields 14 could be omitted but it is preferable to provide them, because they provide support where there would otherwise be none, due to the removal of the lateral uprights of the stationary roadway supports at the face side during passage of the mining equipment. Also, they could be urged into supporting position by equipment other than hydraulic rams, e.g. by screw spindles. The wall shields 14 may be provided on only one or on both of the frames 5, 6; advantageously they are so arranged that while one of the frames 5, 6 is being shifted, the wall shields of the other frame support the wall 15, and vice versa.
While the invention has been illustrated and described as embodied in a walking mine support, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | A walking mine support includes a roadway support unit and a face-gallery support unit laterally of the same. The two units are linked by one or more four-pivot couplings whose members can tilt both lengthwise and transversely of the elongation of the roadway and permit walking movements of the units with reference to one another without interfering with proper support of either the roadway or the face-gallery. | 4 |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The present application is a non-provisional patent application claiming priority under 35 U.S.C. 119 to the following U.S. provisional patent applications: 60/159,337 filed Oct. 13, 1999; 60/178,780 filed Jan. 28, 2000; 60/209,646 filed Jun. 6, 2000; and 60/222,354 filed Aug. 1, 2000. The present application incorporates said before mentioned four provisional patent applications by reference herein in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to electronic communication, and more specifically to coding schema, synchronization schema, demodulation schema, bandwidth efficiency schema, error detection/correction schema, and encryption schema.
BACKGROUND OF THE INVENTION
[0003] Communication systems and methods known to the art utilize a number of digital modulation techniques. Digital modulation techniques known to the art generally encode information by relating the information in different combinations in amplitude, frequency, and phase to a radio frequency carrier. Digital modulation techniques known to the art may include amplitude shift keying, frequency shift keying, phase shift keying, and combinations of the like such as quadrature modulation. In order to decode the modulated signal, receivers need to generate waveform synchronous to the carrier before information can be recovered by applying Fourier expansion/transformation techniques to the modulated signal.
[0004] With differing types of coding/decoding, carrier/symbol synchronization, and error detection/correction, current communication systems and methods may become extremely complex, which in turn, may require very high processing power. In particular, requiring high precision synchrony to the signal carrier and symbol timing by the receivers usually leads to highly complex synchronization circuits.
[0005] Other limitations of current communication systems known to the art is the inability to provide secure communication, free from eavesdropping, without incorporating an encryption system with the system.
[0006] Consequently, it would be advantageous if a system and method of communication existed not requiring specialized circuitry for carrier/symbol synchronization. It would also be advantageous if a system and method of communication existed which required little or minimum circuitry for error detection/correction. It would also be advantageous if a system and method of communication existed which included an inexpensive way to encrypt/decrypt data. Further, it would be advantageous (for the purpose of increasing channel bandwidth efficiency) if a communication system and method existed for which the operations of carrier/symbol synchronization, data extraction, and error detection/correction were all accomplished by essentially one combined operation which were also robust in the presence of noise and signal degradation.
SUMMARY OF THE INVENTION
[0007] Accordingly, the present invention is directed to a communication system and method combining carrier/symbol synchronization, data extraction, error detection/correction in essentially one robust operation, thus significantly reducing receiver's circuit complexity. The system and method of communication of the present invention may include encryption attributes within the system and method.
[0008] It is to be understood, both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention claimed. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention and together with the general description, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The numerous objects and advantages of the present invention may be better understood by those skilled in the art by reference to the accompanying figures in which:
[0010] FIG. 1 depicts a block diagram of an exemplary embodiment of the communication system of the present invention;
[0011] FIG. 2 depicts an exemplary input signal and an exemplary corresponding output signal from a spike burster of the present invention showing an activation and deactivation region, which are determined and controlled by input signal's derivative, and the corresponding output voltage spikes from a spike burster;
[0012] FIG. 3 is another exemplary input signal and an exemplary output signal from a spike burster of the present invention showing an activation and deactivation region, which are determined and controlled by input signal's amplitude, and the corresponding output voltage spikes from a spike burster;
[0013] FIG. 4 ( a ) depicts an exemplary embodiment of a signal's-derivative-controlled spike burster of the present invention showing a voltage input source, a capacitor, and a non-linear resistive network in series;
[0014] FIG. 4 ( b ) depicts an exemplary current-voltage operating curve for a non-linear resistive network of an exemplary embodiment of signal's-derivative-controlled spike burster of the present invention shown in FIG. 4 ( a );
[0015] FIG. 4 ( c ) depicts an exemplary embodiment of a signal's-derivative-controlled spike burster of the present invention showing a current input source, an inductor, and a non-linear resistive network in parallel;
[0016] FIG. 4 ( d ) depicts an exemplary current-voltage operating curve for a non-linear resistive network of an exemplary embodiment of signal's-derivative-controlled spike burster of the present invention shown in FIG. 4 ( c );
[0017] FIG. 5 ( a ) depicts an exemplary embodiment of a signal's-amplitude-controlled spike burster of the present invention showing a voltage input source, an inductor, and a non-linear resistive network in series;
[0018] FIG. 5 ( b ) depicts an exemplary current-voltage operating curve for a non-linear resistive network of an exemplary embodiment of signal's-amplitude-controlled spike burster of the present invention shown in FIG. 5 ( a );
[0019] FIG. 5 ( c ) depicts an exemplary embodiment of a signal's-amplitude-controlled spike burster of the present invention showing a current input source, a capacitor, and a non-linear resistive network in parallel;
[0020] FIG. 5 ( d ) depicts an exemplary current-voltage operating curve for a non-linear resistive network of an exemplary embodiment of signal's amplitude-controlled spike burster of the present invention shown in FIG. 5 ( c );
[0021] FIG. 6 depicts an exemplary embodiment of a derivative-controlled spike burster portion of a receiver of the present invention showing the schematic for an exemplary embodiment of the present invention;
[0022] FIG. 7 depicts an exemplary embodiment of an amplitude-controlled spike burster portion of a receiver of the present invention showing the schematic for an exemplary embodiment of the present invention;
[0023] FIG. 8 ( a ) depicts another exemplary input signal to, and exemplary output signal from, an exemplary embodiment of a signal's-derivative-controlled spike burster of the present invention as measured utilizing an oscilloscope showing arbitrary-shaped input waveforms;
[0024] FIG. 8 ( b ) depicts another exemplary input signal with noise added to, and exemplary output signal from, an exemplary embodiment of a spike burster of the present invention as measured utilizing an oscilloscope;
[0025] FIG. 9 depicts an exemplary input signal to, and exemplary output signal from, an exemplary embodiment of a spike burster of the present invention as measured utilizing an oscilloscope illustrating actual input to, and output from, an exemplary embodiment of a signal's-amplitude-controlled spike burster;
[0026] FIG. 10 ( a ) depicts an exemplary embodiment of derivative-controlled activation and deactivation regions of an exemplary four spike burster receiver system of the present invention;
[0027] FIG. 10 ( b ) depicts another exemplary embodiment of derivative-controlled activation and deactivation regions of an exemplary four spike burster receiver system of the present invention highlighting spike burster one's activation and deactivation region;
[0028] FIG. 10 ( c ) depicts another alternative embodiment of derivative-controlled activation and deactivation regions of an exemplary four spike burster receiver system of the present invention highlighting spike burster two's activation and deactivation region;
[0029] FIG. 11 depicts an input signal to, and an output signal from, an exemplary embodiment of a four spike burster receiver system of the present invention showing the outputs of the respective spike bursters when the input signal in each's derivative-controlled activation region and deactivation region;
[0030] FIG. 12 ( a ) depicts an exemplary embodiment of amplitude-controlled activation and deactivation regions of an exemplary four spike burster receiver system of the present invention;
[0031] FIG. 12 ( b ) depicts another exemplary embodiment of amplitude-controlled activation and deactivation regions of an exemplary four spike burster receiver system of the present invention highlighting spike burster one's activation and deactivation region;
[0032] FIG. 12 ( c ) depicts another alternative embodiment of amplitude-controlled activation and deactivation regions of an exemplary four spike burster receiver system of the present invention highlighting spike burster two's activation and deactivation region;
[0033] FIG. 13 depicts an input signal to, and an output signal from, an exemplary embodiment of a four spike burster receiver system of the present invention showing the outputs of the respective spike bursters when the input signal in each's amplitude-controlled activation region and deactivation region;
[0034] FIG. 14 ( a ) depicts an exemplary sinusoid input signal to and an exemplary corresponding output signal from a spike burster of the present invention showing information is coded by the amplitude of the sinusoidal input signal and information is represented by the number of spikes of the output signal when the spike burster is in activation;
[0035] FIG. 14 ( b ) depicts an exemplary sinusoid input signal to and an exemplary corresponding output signal from a spike burster of the present invention showing information is coded by the frequency of the sinusoidal input signal and information is represented by the number of spikes of the output signal when the spike burster is in activation;
[0036] FIG. 14 ( c ) depicts an exemplary sinusoid input signal to and an exemplary corresponding output signal from a spike burster of the present invention showing information is coded by the phase of the sinusoidal input signal and information is represented by the number of spikes of the output signal when the spike burster is in activation;
[0037] FIG. 14 ( d ) depicts an exemplary sinusoid input signal to and an exemplary corresponding output signal from a spike burster of the present invention showing information is coded by the modulated amplitude of the sinusoidal input signal and information is redundantly represented by the number of spikes of the output signal when the spike burster is in activation;
[0038] FIG. 14 ( e ) depicts an exemplary sinusoid input signal to and an exemplary corresponding output signal from a spike burster of the present invention showing information is coded by the modulated frequency of the sinusoidal input signal and information is redundantly represented by the number of spikes of the output signal when the spike burster is in activation;
[0039] FIG. 14 ( f ) depicts an exemplary sinusoid input signal to and an exemplary corresponding output signal from a spike burster of the present invention showing information is coded by the modulated phase of the sinusoidal input signal and information is represented by the number of spikes of the output signal when the spike burster is in activation and during the phase changes;
[0040] FIG. 15 depicts an exemplary sinusoid input signal to and two exemplary corresponding output signals from spike burster(s) of the present invention showing information is coded by the modulated phase of the sinusoidal input signal and information is represented by the burst initiation times of the output signal;
[0041] FIG. 16 depicts an exemplary sinusoid input signal to and two exemplary corresponding output signals from spike burster(s) of the present invention showing information is coded by the modulated amplitude and phase of the sinusoidal input signal and the bit information in phase is represented by the burst initiation times of the output signal;
[0042] FIG. 17 illustrates a 16 state-point quadrature amplitude modulation polar coordinate diagram (QAM constellation) wherein the efficiency of the present invention is illustrated;
[0043] FIGS. 18 ( a ) and 18 ( b ) illustrate more preferred constellations and the increased bandwidth efficiency of some embodiments of the present invention:
[0044] FIG. 19 depicts an exemplary embodiment of a spike burster utilized to create part of a spike burster receiver systems within the present invention;
[0045] FIG. 20 depicts an exemplary embodiment of a coder utilized to code data for transmission within the present invention; and
[0046] FIG. 21 depicts an exemplary embodiment of an adaptive counter circuit of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0047] Reference will now be made in detail to a presently preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings.
[0048] FIG. 1 generally depicts a block diagram of an exemplary embodiment of the present invention. In FIG. 1 , a digital number 01010 may be inputted 102 into the system of the present invention. A digital signal representation 104 of the digital sequence 01010 is shown. The digital representation 104 then may enter a modulator/signal generator 106 . The modulator/generator 106 may be constructed to modulate the signal many different ways including amplitude modulation, frequency modulation, phase modulation, frequency shift keying, and the like. The modulated signal may then be transmitted 108 over a particular medium. The particular medium may include wired or wireless transmission. The transmitted modulated signal 108 is received at the receiver(s) 110 . The receiver(s) 110 are designed such that all spike burster activation regions together cover the entire area in which the transmitted modulated signal 108 may lie. When the voltage or current of a signal entering a spike burster lies inside a burst activation region, as defined by the circuitry of the spike burster, the spike burster outputs a pulse stream or spike burst. A spike burster's activation region is a range of voltages or currents of the input signal or the derivative of the input signal which causes the spike burster to output spikes. By using more than one spike burster, it is possible to decode more than one bit per wavelength. The receiver(s) 110 may convert the transmitted modulated signal to voltage or current spikes 112 . Each spike burster may output a predetermined number of voltage or current spikes when the transmitted modulated signal 108 is within the spike burster's activation region. For example, the output spike 112 signals may be summed using a summing operational amplifier or the burst timing may be recorded by a threshold or duty cycle timer and then converted to the final number 116 with a digital wave generator or counter 114 .
[0049] FIG. 2 shows an exemplary transmitted modulated signal 202 as a function of voltage in time and the corresponding output voltage spikes 210 from a spike burster. Typical deactivation regions 206 and activation regions 208 of the spike burster are determined by the derivative 204 of the signal 202 . The activation region may be only a fraction of one wavelength in length. Since the transmitted modulated signal 302 may enter more than one activation region every wavelength, more than one bit may be decoded per wavelength. The spike burster may output voltage spikes 210 when the transmitted modulated signal 202 is within the activation region 208 . FIG. 2 shows the output of voltage spikes 210 while the transmitted modulated signal 202 is in the activation region 208 . Current spikes from the spike burster may also be used.
[0050] The number of voltage spikes 210 outputted by a spike burster may be limited to a particular set of numbers of voltage spikes 210 using, for example, a counter and clipper circuit. Each spike burster may then output a known number of voltage spikes each time the transmitted modulated signal enters the spike burster's activation region. The output voltage 210 has a near-constant maximum voltage 212 and a near-constant minimum voltage 214 when the transmitted modulated wave 202 is not in the activation region 208 and is in the deactivation region 206 of the spike burster.
[0051] FIG. 3 shows another exemplary transmitted modulated signal 302 and the corresponding output voltage spikes 304 from the spike burster. Again similar to the case of signal's derivative-controlled spike bursters as of FIG. 2 , the transmitted modulated signal 302 may enter more than one activation region every wavelength, more than one bit may be decoded per wavelength. An exemplary deactivation region 306 and activation region 308 are shown. The spike burster outputs voltage spikes 304 when the transmitted modulated signal 302 may be located within the activation region 308 , and outputs a near-constant, lower voltage 310 or a near-constant, higher voltage 312 when the transmitted modulated signal 302 is located in the spike burster's deactivation region 306 . Current spikes from the spike burster may be used, as well as voltage spikes. Since the input signal's profile (shape, form) is not limited in order to cause a spike burster to output burst of spikes, and since activation and deactivation regions can be arbitrarily specified for a spike burster, information embedded to a transmitting signal may be made secure because only that spike burster may output correct spike bursts representing the message.
[0052] FIG. 4 ( a ) depicts an exemplary circuit type of signal's-derivative-controlled spike burster. An input voltage source 402 is in series with a capacitor 404 and a non-linear resistive network 406 whose current-voltage operating curve has an exemplary shape of 408 . The load line 410 is controlled by the input source's derivative. The signal input 402 enters the spike burster's activation region when the load line 410 cuts across the negative resistant branch of the current-voltage operating curve 408 . The voltage spikes move from point b to point c on 408 when in its upward swing and from point d to point a on 408 when in its downward swing. The current spikes move from point c to point d when in its upward swing and from point a to point b when in its downward swing. Together, the operating point in the voltage and the current move around the cycle abcd during spike burster activation. The signal input 402 enters the spike burster's deactivation region when the load line 410 cuts across the positive resistant branches of the current-voltage operating curve 408 . When the load line 410 cuts either of the near-vertical branches of 408 , the voltage output reaches either a near-constant maximum value such as 212 or a near-constant minimum value such as 214 of FIG. 2 .
[0053] FIG. 4 ( c ) depicts another exemplary circuit type of signal's-derivative-controlled spike burster. An input current source 412 is in parallel with an inductor 414 and in parallel with a non-linear resistive network 416 whose current-voltage operating curve has an exemplary shape of 418 . The load line 420 is controlled again by the input current source's derivative. The signal input 412 enters the spike burster's activation region when the load line 420 cuts across the negative resistant branch of the current-voltage operating curve 418 . The voltage spikes move from point c to point d when in its downward swing and from point a to point b when in its upward swing. The current spikes move from point d to point a on 418 when in upward swing and from point b to point c on 418 when in its downward swing. Together, the operating point in the voltage and the current move around the cycle abcd during spike burster activation. The signal input 412 enters the spike burster's deactivation region when the load line 410 cuts across the positive resistant branches of the current-voltage operating curve 418 . When the load line 420 cuts either of the near-horizontal branches of 418 , the current output reaches either a near-constant maximum value such as 212 or a near-constant minimum value such as 214 of FIG. 2 .
[0054] FIG. 5 ( a ) depicts an exemplary circuit type of signal's-amplitude-controlled spike burster. An input voltage source 502 is in series with an inductor 504 and a non-linear resistive network 506 whose current-voltage operating curve has an exemplary shape of 508 . The load line 510 is controlled by the input voltage source's amplitude. The signal input 502 enters the spike burster's activation region when the load line 510 cuts across the negative resistant branch of the current-voltage operating curve 508 . The voltage spikes move from point c to point d when in its downward swing and from point a to point b when in its upward swing. The current spikes move from point d to point a on 518 when in its upward swing and from point b to point c on 518 when in its downward swing. Together, the operating point in the voltage and the current move around the cycle abcd during spike burster activation. The signal input 502 enters the spike burster's deactivation region when the load line 510 cuts across the positive resistant branches of the current-voltage operating curve 508 . When the load line 510 cuts either of the near-horizontal branches of 508 , the current output reaches either a near-constant maximum value such as 212 or a near-constant minimum value such as 214 of FIG. 2 .
[0055] FIG. 5 ( c ) depicts another exemplary circuit type of signal's-amplitude-controlled spike burster. An input current source 512 is in parallel with a capacitor 514 and in parallel with a non-linear resistive network 516 whose current-voltage operating curve has an exemplary shape of 518 . The load line 520 is controlled again by the input current source's amplitude. The signal input 512 enters the spike burster's activation region when the load line 520 cuts across the negative resistant branch of the current-voltage operating curve 518 . The voltage spikes move from point b to point c on 518 when in its upward swing and from point d to point a when in its downward swing. The current spikes move from point c to point d, when in its upward swing and from point a to point b when in its downward swing. Together, the operating point in the voltage and the current move around the cycle abcd during spike burster activation. The signal input 512 enters the spike burster's deactivation region when the load line 520 cuts across the positive resistant branches of the current-voltage operating curve 518 . When the load line 520 cuts either of the near-vertical branches of 518 , the voltage output reaches either a near-constant maximum value such as 212 or a near-constant minimum value such as 214 of FIG. 2 .
[0056] FIG. 6 depicts an exemplary embodiment of a circuit which may be utilized as a spike burster portion of a receiver controlled by signal's derivative. By adjusting the values of the individual components, the activation region and deactivation region of the spike burster may be adjusted. More than one spike burster 600 may be used at the same time to decode a transmitted modulated signal 602 . For example, the input 602 is where a transmitted modulated signal enters the spike burster 600 . The capacitor 604 is connected to the negative input of an operational amplifier 606 . Also connected to the negative input of the operational amplifier is a negative feedback resistor 608 . Again the negative feedback resistor 608 may be adjusted to vary the activation region of the spike burster 600 . The power voltage connected to the positive power input 610 of the operational amplifier 606 defines the amplitude of the output voltage spikes. The value of the power voltage 610 will be the maximum amplitude of the output voltage spikes. The negative power input 612 to the operational amplifier 606 is connected to ground 620 . A positive feedback resistor 614 is connected from the positive input of the operational amplifier 606 to the output 618 of the spike burster 600 . Again the value of the positive feedback resistor 614 may be adjusted to vary the activation region of the spike burster 600 . The ground resistor 616 is connected to the positive input to the operational amplifier 606 and to ground 620 . The output 618 of the spike burster 600 is where the voltage spikes are outputted to the rest of the receiver.
[0057] FIG. 7 depicts an exemplary embodiment of a spike burster circuit which is controlled by signal's amplitude. The input 702 is where a transmitted modulated signal enters the spike burster 700 . The inductor 704 is connected to the positive input of an operational amplifier 706 . Also connected to the positive input of the operational amplifier is a negative feedback resistor 708 . Again the negative feedback resistor 708 may be adjusted to vary the activation region of the spike burster 700 . The negative power input 712 to the operational amplifier 706 is connected to ground 720 . A positive feedback resistor 714 is connected from the negative input of the operational amplifier 706 to the output 718 of the spike burster 700 . Again the value of the positive feedback resistor 714 may be adjusted to vary the activation region of the spike burster 700 . The ground resistor 716 is connected to the negative input to the operational amplifier 706 and to ground 720 . The output 718 of the spike burster 700 is where the voltage spikes are outputted to the rest of the receiver.
[0058] FIG. 8 ( a ) shows an exemplary screen printout from an oscilloscope with an input wave 802 that includes a combination of distinctly-shaped waves. The input wave to the receiver(s) need not be sinusoidal in character. The corresponding output 804 is shown for a spike burster 600 with the following values: the capacitor 604 is 10 nanofarads; the operational amplifier 606 is National Semiconductor's part number LM 358 ; the value of the negative feedback resistor 608 is 1000 ohms: the value of the power voltage 610 to the operational amplifier 606 is 1.6 volts; the value of the positive feedback resistor 612 is 10 ohms; the value of the ground resistor 616 is 100 ohms. The activation region 806 of this spike burster is negative edge triggered and lasts until the slope of the input signal 802 is non-negative (either positive or zero slope). The deactivation region 810 is non-negative edge triggered and lasts until the slope of the input signal 802 is negative. The output 804 of this spike burster outputs spikes while the input signal 802 has a negative slope. The output 804 has a constant low voltage when the input signal 802 has a non-negative slope.
[0059] FIG. 8 ( b ) shows the same input signal 802 as in FIG. 8 ( a ) with noise added to the input 802 . With the present invention, the spike burster will still output the same voltage spikes 812 even with a significant amount of noise added to the input signal 802 . The activation boundary of 808 may be raised or lowered by changing the values of the individual components as shown in FIGS. 10, 11 and 19 .
[0060] FIG. 9 shows an exemplary screen printout from an oscilloscope with the input wave 902 as a triangular wave. The corresponding output 904 is shown for a spike burster 700 with the following exemplary values; the inductor 704 is 68 millihenrys (mH), the operational amplifier 706 is National Semiconductor part number LM 358 ; the value of the negative feedback resistor 708 is 820 ohms; the value of the power voltage 710 to the operational amplifier 706 is 1.8 volts; the value of the positive feedback resistor 712 is 39 ohms; and the value of the ground resistor 716 is 100 ohms. The activation region 906 of the spike burster 700 is above the activation threshold 908 . The deactivation region 910 is the area below the activation threshold 908 . The output 904 of the exemplary spike burster may output spikes while the signal remains above the activation threshold 908 and within the activation region 906 . Again, the number of output voltage spikes 904 may be limited to a known number of output voltage spikes if more than one spike burster is used, such that the particular number of spikes corresponds to a particular symbol or number. The activation threshold 908 may be raised or lowered by changing the values of the individual components as shown in FIGS. 12, 13 and 19 .
[0061] FIG. 10 ( a ) shows an exemplary embodiment of signal's-derivative-controlled activation and deactivation regions of an exemplary four spike burster receiver system of the present invention. Spike burster one's activation region 1002 includes the area above spike burster one's activation threshold 1010 . Spike burster one's deactivation region includes the area below spike burster one's activation threshold 1010 . Spike burster one's deactivation region includes spike burster two's activation region 1004 , spike burster three's activation region 1006 and spike burster four's activation region 1008 , as shown by the shaded area in FIG. 10 ( b ). Spike burster two's activation region 1004 is between spike burster two's activation threshold 1012 and spike burster one's activation threshold 1010 .
[0062] As shown by the shaded area in FIG. 10 ( c ), spike burster two's deactivation region may include the area above spike burster one's activation threshold 1010 and the area below spike burster two's activation threshold 1012 . Spike burster two's deactivation region includes spike burster one's activation region 1002 , spike burster three's activation region 1006 and spike burster four's activation region 1008 . Spike burster three's activation region 1006 is between spike burster two's activation threshold 1012 and spike burster three's activation threshold 1014 . Spike burster three's deactivation region includes the area above spike burster two's activation threshold 1012 and the area below spike burster three's activation threshold 1014 . Spike burster three's deactivation region includes spike burster one's activation region 1002 , spike burster two's activation region 1004 and spike burster four's activation region 1008 . Spike burster four's activation region 1008 includes the area below spike burster 3 's activation threshold 1014 . Spike burster 4 's deactivation region includes spike burster one's activation region 1002 , spike burster two's activation region 1004 and spike burster three's activation region 1006 . Spike burster four's deactivation includes the area above spike burster four's activation threshold 1014 .
[0063] FIG. 11 shows an input wave 1102 , by way of example only, in one input cycle to the four spike burster system depicted in FIG. 10 ( a ). As the input wave is within each particular spike burster activation region 1104 , 1106 , 1108 , 1110 each spike burster correspondingly outputs voltage spikes 1112 , 1114 , 1116 , 1118 . When the input wave 1102 is in the spike burster one's activation region 1104 , spike burster one's output 1112 outputs voltage spikes. When the input wave 1102 is not in spike burster one's activation region 1104 , spike burster one's output 1112 is a constant flat voltage. As the input 1102 passes into spike burster two's activation region 1106 , spike burster two's output 1114 outputs voltage spikes. When the input 1102 is not in spike burster two's activation region 1106 , spike burster two's output 1114 is a constant flat voltage. When input 1102 lies within spike burster three's activation region 1108 , spike burster three's output 1116 outputs voltage spikes. When the input wave 1102 is not in spike burster three's activation region 1108 , spike burster three's output 1116 is a constant flat voltage. Finally, when the input 1102 lies within spike burster four's activation region 1110 , spike burster four's output 1118 outputs voltage spikes. When the input wave 1102 is not in spike burster four's activation region 1108 , spike burster four's output 1118 is a constant flat voltage.
[0064] The present invention may also utilize a natural adaptive timing property. The input wave 1102 does not have to be synchronized with the spike bursters 1104 , 1106 , 1108 , 1110 . When the input wave 1102 is within a particular spike burster's activation region, that spike burster outputs voltage spikes. When the input signal starts, the output starts. Therefore, when the outputs 1112 , 1114 , 1116 , 1118 from each spike burster 1104 , 1106 , 1108 , 1110 may be summed using, for example, a summing operational amplifier, the data will exit the spike burster system in the same order that the data came into the spike burster system. Using the four spike burster system in FIG. 10 with four variations of the spike burster in FIG. 19 , and an amplitude modulator 106 for the coder, increased bandwidth efficiency may be obtained.
[0065] FIG. 12 ( a ) shows an exemplary embodiment of signal's-amplitude-controlled activation and deactivation regions of an exemplary four spike burster receiver system of the present invention. Spike burster one's activation region is 1202 . Spike burster two's activation region is 1204 . Spike burster three's activation region is 1206 . And spike burster four's activation region is 1208 . With the signal replacing signal's derivative in FIGS. 10 and 11 , the explanation for FIG. 12 is similar to that of FIG. 10 .
[0066] FIG. 13 shows an input wave 1302 in one input cycle to the four spike burster system depicted in FIG. 12 ( a ). Again, with the signal itself replacing signal's derivative in FIGS. 10 and 11 , the explanation for FIG. 13 is similar to that of FIG. 11 .
[0067] FIG. 14 ( a ) shows an exemplary embodiment of a sinusoid signal 1402 with a fixed frequency but two varying amplitudes onto which information in symbol sequence 0110 is encoded, and an exemplary output 1404 of an amplitude-controlled spike burster of a receiver of the present invention. The spike number sequence that represents the symbol sequence 0110 is 1221 in two varying spike numbers. The output burst is in synchrony with input's change in amplitude.
[0068] FIG. 14 ( b ) shows an exemplary embodiment of a sinusoid signal 1406 with fixed amplitude but two varying frequencies onto which information in symbol sequence 10010 is encoded, and an exemplary output 1408 of a derivative-controlled spike burster of a receiver of the present invention. The spike number sequence that represents the symbol sequence 10010 is 21121 in two varying spike numbers. The output burst is in synchrony with input's change in frequency.
[0069] FIG. 14 ( c ) shows an exemplary embodiment of a sinusoid signal 1410 with a fixed frequency but two varying phases taking place during activation onto which information in symbol sequence 011001 is encoded, and an exemplary output 1412 of a derivative-controlled spike burster of a receiver of the present invention. The spike number sequence that represents the symbol sequence 011001 is 122112 in two varying spike numbers. Again, the output burst is in synchrony with input's change in phase.
[0070] FIG. 14 ( d ) shows an exemplary embodiment of a sinusoid signal 1414 which is an exemplary carrier-modulated wave of the baseband signal 1402 of FIG. 14 ( a ). Each baseband symbol cycle repeats (in an exemplary embodiment) three times on the carrier to create a modulated symbol cycle. That means the frequency ratio between the carrier cycle and the symbol cycle is 3:1. The symbol sequence 0110 is encoded with two varying modulated amplitudes. An exemplary output 1416 of an amplitude-controlled spike burster of a receiver of the present invention shows a spike number sequence representation 111222222111 with each symbol repeatedly decoded three times, the ratio of carrier frequency to symbol frequency. By decoding a given symbol many times over, errors due to system distortions other than information source error may be detected and corrected. This redundancy is the basis of error detection/correction attribute built into the communication method of the present invention. Also, output bursts are in synchrony with the modulated signal cycles.
[0071] FIG. 14 ( e ) shows an exemplary embodiment of a sinusoid signal 1418 which is an exemplary carrier-modulated wave of the baseband signal 1406 of FIG. 14 ( b ). Each symbol cycle repeats (in an exemplary embodiment) three times on the carrier. The symbol sequence 10010 is encoded with two varying modulated frequencies. An exemplary output 1420 of an derivative-controlled spike burster of a receiver of the present invention shows a spike number sequence representation 222111111222111 with each symbol repeatedly decoded by the same number of times as the ratio of carrier frequency to symbol frequency. Again, similar to FIG. 14 ( d ), errors due to system distortions other than information source errors can be detected and corrected. Also, output bursts to modulating cycles are in synchrony.
[0072] FIG. 14 ( f ) shows an exemplary embodiment of a sinusoid signal 1422 which is an exemplary carrier-modulated wave of the baseband signal 1410 of FIG. 14 ( c ). Unlike the cases of FIGS. 14 ( d ), each symbol represented by varying phase does not repeat with the carrier. For the symbol sequence 011001 carried by the signal, the spike number sequence representation is 331332332331 . . . by an exemplary output 1424 of a derivative-controlled spike burster of the present invention. Each symbol is not decoded redundantly by counting spike number. However, it may be decoded redundantly by an exemplary technique ( FIG. 15 ) wherein the starting time of each burst is used for redundancy symbol decoding. Again, output bursts to modulating cycles are in synchrony.
[0073] FIG. 15 shows an exemplary embodiment phase-modulated sinusoid input signal 1504 and two exemplary spike burst outputs 1506 , 1508 of a derivative-controlled spike burster(s) of a receiver of the present invention. The sinusoid carrier has a fixed frequency with cycle period denoted by T 0 . The burst activation threshold for a signal 1504 to enter an activation region is exemplarily set at the point its slope changes from positive to negative, that is, at the point the signal 1504 reaches its maximum value. The burst deactivation threshold for a signal 1504 to enter a deactivation region is exemplarily set at the minimum point of the signal 1504 (although it is not necessary to set either point at a special location).
[0074] Signal 1504 encodes an exemplary symbol sequence 1502 with 0 and 1 for the symbols. Each symbol is represented by a phase-modulated wave. One full carrier cycle is set to start at the zero voltage level 1518 in upward moving direction and to end at 1518 in an upward moving direction as well. Output bursts to carrier cycles alone are synchronized periodically T 0 period apart. Symbol 0 's wave is constructed by deleting a signal segment of a 0 fraction of the period T 0 in time length from a waveform of 3 full carrier cycles. If 0<a 0 <1/4, symbol 0 's wave results in an advance of burst activation by the amount of a 0 *T 0 in time. In other words, the two consecutive and transitional burst activation times are shortened by a 0 *T 0 units in time such as 1520 . FIG. 15 is the case with a 0 =1/8. On the other hand. Symbol 1 's wave is constructed by adding a signal segment of d 0 fraction of the period T 0 to a waveform of 3 full carrier cycles. If 0<d 0 <1/4, this symbol wave results in a delay in burst activation by the amount of d 0 *T 0 in time. In other words, the two consecutive and transitional burst activation times are lengthened by d 0 *T 0 units in time such as 1522 . FIG. 15 illustrates d 0 =1/8. With 1/4<a 0 <1/2 and/or 1/4<d 0 <1/2, corresponding burst activation shifts may also be obtained similarly. Output waves of 1504 and 1506 may, for example, either be two different outputs in voltage or current of one spike burster or two different outputs of two distinct spike bursters. Denote the burst initiation moment that the signal 1504 crosses the burst activation threshold by . . . τ −2 , τ −1 , τ 0 , τ 1 , τ 2 . . . 1510 with τ 0 the most present moment, τ −1 the moment before τ 0 and τ 1 the moment after τ 0 , and so on. Each burst initiation moment, τ j , may be determined from spike burster outputs 1506 , 1508 either by a voltage threshold counter or by a cycle timer. For example, a voltage threshold 1512 may be preset between the minimum value of the spikes 1514 and the near-constant deactivation voltage 1516 . Then burst initiation time τ j may be defined as an average of a time interval during which the output 1506 swings upwards and crosses the voltage threshold 1512 . As for output type 1508 , the burst initiation time τ j may be defined to be an average moment that the output 1508 becomes active in spiking after a preset long pause of staying near-constant deactivation voltage.
[0075] Having the burst initiation time sequence . . . τ −2 , τ −1 , τ 0 , τ 1 , τ 2 . . . 1510 enables the receiver to decode each symbol by a preset number of time. For the exemplary phase-shift-keyed sinusoid signal 1504 , symbol 0 's waveform advances the next burst by 1/8 of the carrier period in length, and symbol 1 's waveform delays the next burst by 1/8 of the carrier period in length. Therefore, the time lapse between consecutive burst initiation times, τ j -τ j-1 , is exactly the period of the carrier (8/8 T 0 ) if it does not occur during a transition between symbols. The time lapse is correspondingly 7/8 of the carrier period for symbol 0 and 9/8 of the carrier period symbol 1 respectively. Having this burst time lapse sequence {τ j -τ j-1 } requires the receiver to remember the last burst initiation time τ j-1 , (a 1-memory receiver). The burst time lapse sequency {τ j -τ j-1 } will exhibit the following exemplary pattern for the symbol sequence . . . 0101 . . . , using 1/8 of the carrier period as the unit of time,
. . . 7 8 8 9 8 8 7 8 8 9 8 8 . . .
However, if the decoder uses a 2-memory burst time lapse sequence {τ j -τ j-2 }, the sequence will exhibit the following exemplary pattern for the same symbol sequence, using 1/8 of the carrier period as the unit of time as well,
. . . 15 15 16 17 17 16 15 15 16 17 17 16 . . .
With such an exemplary 2-memory decoder, each symbol is decoded twice. Similarly, a 3-memory burst time lapse sequence {τ j -τ j-1 } looks like
. . . 23 23 23 25 25 25 23 23 23 25 25 25 . . .
decoding each symbol three times in repetition. In general, with a k-memory decoder or the like, so long as k is not greater than the ratio of the carrier frequency to the symbol frequency, then each symbol may be decoded k times redundantly. The signal symbol is in synchrony with burst lapse sequences.
[0079] FIG. 16 shows an exemplary phase and amplitude modulated sinusoid input signal 1604 and two exemplary spike burst outputs 1606 , 1608 of a derivative-controlled spike burster(s) of a receiver of the present invention. Output waves 1604 and 1606 may either be two different outputs in voltage or current of one spike burster or two different outputs of two distinct spike bursters. The activation threshold for the signal 1604 to enter the activation region is exemplarily set at the points its slope changes from positive to negative, and the deactivation threshold is set at the minimum points of the signal, all similar to FIG. 15 . The signal 1604 encodes an exemplary symbol sequence 1602 . Each symbol is a string of two digits in 0 and 1: 00, 01, 10, 11. Each symbol carries two bits of information. The first digit (counted from the right most place, e.g., 0 is the first digit of the symbol 10 ) is represented by a phase shift of the modulating sinusoid carrier of a fixed period T 0 . Digit 0 has an advance shift in burst activation by the amount of 1/8 the carrier period in time, and digit 1 has a delay shift in the burst activation by the amount of 1/8 the period in time.
[0080] The second digit (e.g., 1 of the symbol 10 ) is represented by an amplitude shift of the modulating sinusoid carrier, with the low amplitude for 0 and the high amplitude for 1. Denote the burst initiation moment that the signal 1604 crosses the activation threshold by . . . τ −2 , τ −1 , τ 0 , τ 1 , τ 2 . . . 1610 with τ 0 the most present moment, τ −1 the moment before τ 0 and τ 1 the moment after τ 0 , and so on. Each burst initiation moment, τ j , may be determined from spike burster outputs 1606 , 1608 either by a voltage threshold counter or by a cycle timer similar to FIG. 15, 1512 , 1514 , 1516 . Thus, similar to FIG. 15 , the phase shifts of the carrier in burst activation may be detected and the first symbol digit can be decoded. Shifts in carrier amplitude may be detected by either amplitude envelope techniques or by amplitude-controlled spike bursters in addition to the phase shift detecting, derivative-controlled spike bursters. Together, each symbol can be decoded, and each can be synchronized with its corresponding burst initiation time.
[0081] FIG. 17 is an exemplary 16 state-point (data point) quadrature polar coordinate diagram. This diagram shows the 16 available quadrature data points in black circles. These quadrature points occupy one of the 12 phases and 3 amplitude rings. FIG. 17 also shows an additional set of non-quadrature points which share the same phase and amplitude as the various quadrature points. There are an additional 20 non-quadrature data points available under a preferred embodiment in this example of the present invention ( FIG. 17 , grey circles). This provided a bandwith efficiency gain over the quadrature points alone (ln36/ln2=5.17 bits/s/Hz). Additionally, the diagram also shows an additional 12 corresponding data points ( FIG. 17 , white circles). These corresponding data points both lie on the same amplitude rings as the quadrature points and their phase differences are comparable to the phase differences between quadrature points. By adding these corresponding data points a bandwith efficiency gain may be provided (ln48/ln2=5.85 bits/s/Hz).
[0082] For example, telephone modems utilize quadrature modulation with M-ary signaling. The signal may take the form I*cos(ωt)+Q*sin(ωt) with I the in-phase component and Q the quadrature component, and ω/2*π the carrier frequency. With M states, each state point (I j ,Q k ),j=1,2, . . . , m 1 ; k=1,2, . . . , m 2 ; and m 1 *m 2 =M) carries r=ln(M)/ln2 bits of information, and the bandwidth efficiency factor is r bits/s/Hz. We may rewrite the signal form into I*cos(ωt)+Q*sin(ωt)=A*cos(ωt−P) with A=sqrt(I 2 +Q 2 ), tan(P)=Q/I. A as the amplitude and P as the phase shift. Therefore, the M states (I j ,Q k ) in terms of the phase shift P {jk} with tan(P {jk} )=Q k /I j , and the amplitude A {jk} . Thus, for large M, there usually are more than sqrt(M) distinct phases P {jk} and more than sqrt(M) amplitude A {jk} . Denoting the number of distinct phase by N p and the number of distinct amplitude by N a . The foregoing analysis provides
N a >sqrt ( M ) and N p >sqrt ( M )
and the total number of state points in A and P [(A,P)-state points], of which the quadrature points are a part is
L=N a *N p >sqrt ( M )* sqrt ( M )= M.
[0083] Stated differently, each quadrature point occupies a spot in the phase-amplitude constellation (A,P), but there are more (A,P)-state points not occupied by an M-ary quadrature point. Moreover, an (A,P) state point which is not a quadrature point gives rise to the same signal characteristics as a quadrature does, in particular, in terms of the signal to noise ratio. This means, if the channel allows a quadrature-point signal through, it should allow a non-quadrature (A,P)-state signal through as well. All (A,P)-state signal may also pass through the channel. Also, if two quadrature points are distinguishable at the receiver, so are their amplitudes and phases. Therefore, two (A,P)-state points should be distinguishable at the receiver as well because they share the same amplitude and phases as various quadrature points. The present invention may be utilized to capture these (A,P)-state points (orphan points). Thus, allowing for an increase in the bit efficiency factor (R=ln(L)/ln2 bits/s/Hz) and the gain factor over the quadrature efficient factor
R/r =ln( L )/ln( M ).
[0084] Using conventional Fourier methods to recover the quadrature point (I,Q) does not necessarily recover the phase P=tan −1 (Q/I). Since doing division Q/I or I/Q is tricky, as I, Q may be very small, and round-off errors may be overwhelming, the present invention preferably measures the phase shift of the signal ( FIGS. 15 and 16 ). The practicable measurability is improved by the spike burster of the present invention. The phase shift of the input signal to a derivative-controlled spike burster causes a time shift in the burst activation of the output.
[0085] FIG. 18 shows two exemplary (A,P)-state point constellations. In FIG. 18 ( a ), there are 4=2 2 amplitude rings spaced apart equally and 8=2 3 phase rays also spaced apart equally. In an exemplary embodiment, each gray point (data point) carries 5 bits of information. We may determine the amplitude A and phase shift P of a symbol signal A cos(ωt−P) ( 1604 , FIG. 16 ). In terms of the polar coordinate (A,P), the direction of the phase is along the concentric amplitude circles and the direction of the amplitude is along the equal-phase rays. These directions are orthogonal and representing symbols by varying amplitudes and phases of the sinusoid signal is an example of orthogonal signaling, given that quadrature amplitude modulation is another example of orthogonal signaling. This means that on two distinct rays the phase distance between two points from an inner amplitude ring is the same as two points from an outer amplitude ring. However, in terms of their in-phase and quadrature point signaling, the inner ring points are much closer to each other than the outer ring points. Thus, a quadrature modulation/demodulation scheme which is able to distinguish outer ring (A,P)-points may not necessarily be able to distinguish inner ring (A,P) data points. In other words, which signal characteristics a particular method chooses to measure should strongly effect the method's utilization of bandwidth. The present invention measures the phase and amplitude independently. Inner ring points are spaced equally apart in phase as outer ring points. Their differences are only in varying amplitude.
[0086] FIG. 18 ( b ) is another (A,P)-point constellation which may be utilized by the present invention. There are 4=2 2 equally spaced amplitude rings and 16=2 4 equally spaced phase rays. Each data point carries 6 bits of information. Compared to the 16-QAM constellation of FIG. 17 (black points), the signal characteristics are comparable. However, each of the 16-QAM point carries only 4 bits of information. The efficiency gain is (6−4)/4=50%.
[0087] FIG. 19 depicts an exemplary embodiment of a circuit which may be utilized as the spike burster portion in an embodiment of the present invention. By adjusting the values of the individual components in the circuit, the activation region and deactivation region of the spike burster may be adjusted. The input 902 is where the transmitted input signal(s) enter the spike burster circuit. The input resistor, Ri, provides impedance control appropriate for the input signal used in the application.
[0088] Operational amplifiers 904 . 906 are used as voltage followers to buffer the input signal and limit loading on the input line 902 . This allows the impedance to be completely defined by the input resistor, Ri. Since the operational amplifiers are inverting buffers, two are used to return the correct input signal. These operational amplifiers 904 , 906 could be National Semiconductors part number LM 1458. The next operational amplifiers 912 , 914 are part of a comparator that sets the active range of the spike burster. The use of this comparator provides control over the upper and lower limits of the spike bursting activity. National Semiconductor part number LM 393 could be used for these operational amplifiers 912 , 914 . These operational amplifiers ( 912 , 914 ) usually have their outputs pulled high in operation. This allows for several such comparators to be cascaded as has been done in this circuit. The circuit may be powered by +5 volts and −5 volts as shown at various points in the circuit. This allows for positive and negative input signals to be used entering the circuit at 902 . The lower threshold voltage. V lt , 908 is defined by the power voltage range multiplied by a particular ratio of the lower threshold resistors R 1 and R 2 . V lt 908 is defined by the circuit as
V lt =+5−(−5)*( R 2 /( R 1 + R 2 )+(−5).
Therefore, the lower threshold voltage, V lt 908 , may be positioned by a particular ratio of R 2 /(R 1 +R 2 ) multiplied by the power voltage. For instance, if R 2 was very large in comparison to R 1 , the ratio of R 2 /(R 1 +R 2 ) would be nearly 1 which would make the lower limit voltage V lt 908 very close to 5 volts. If R 1 =R 2 then the lower threshold voltage V lt 908 would be 0 volts. If R 2 were 0, then the lower threshold voltage V lt 908 would be −5 volts. The upper threshold voltage V ut , 910 is then defined as a particular ratio of the upper threshold resistors R 3 , R 4 multiplied by the power voltages +5 and −5 volts. The particular ratio is defined as
V ut =+5−(−5)*( R 4 /( R 3 + R 4 ))+(−5).
Therefore, the upper limit voltage V ut 910 may, be manipulated by the same changes in R 3 and R 4 as were shown with the lower threshold voltage V lt 908 , using R 1 and R 2 . The operational amplifier 916 acts as a derivative detector circuit. It detects the negative slope of the analog input waveform. It does this by imposing a lag time on the input to the circuit, R 5 and C 1 define the lag time coefficient
τ= R 5 * C 1 .
The lag time coefficient τ should be less than 1% of the period of the analog waveform to insure that the spike burst occurs in a timely manner. Therefore, on the rising portions of the input waveform, the positive input will always be less than the negative input. This keeps the output of the operational amplifier 916 low, thereby disabling the transistor 918 . This also keeps the rest of the circuit from outputting spike bursts. If the input signal voltage entering the circuit at 902 is greater than the lower threshold limit V lt 908 and less than the upper threshold limit V ut 910 , and the signal has a negative slope, the comparator will enable the spike burster through the transistor 916 . In the exemplary embodiment, the resistor R 5 was set at 500 ohms so that the signal traveling to the transistor 916 is TTL or CMOS compatible. The spike burster operational amplifier 920 is part of the circuit that functions as a variable duty multivibrator or spike burster.
[0089] When enabled, the amplifier 920 outputs a pulse stream or spike burst. The NPN transistor 916 enables or disables the rest of the circuit. The part of the circuit below the transistor is very much like the spike burster in FIG. 4 . So the transistor 916 enables or disables the spike burster. The transistor 916 could be a National Semiconductor part number 2N2222. The positive feed back resistor, R 6 and the positive feedback to ground resistor R 7 set the multivibrator threshold. For simplicity we set R 6 =R 7 . The ratio between the negative feedback resistor R 8 and the transistor resistor R 9 sets the duty cycle output from the multivibrator. Setting R 8 =R 9 creates an equal on and off cycle for the spikes within the spike burst stream. The transistor 916 and the diode 918 control the charge and discharge cycles for the capacitor C 1 . These components, along with R 8 and R 9 control the on and off times for the multivibrator. The diode 918 and R 8 assures that there will be no partial spikes outputted. The on time T on , for the multivibrator is defined by
T on =R 8 * C 1 *ln(1+((2 *R 6 )/ R 7 ).
[0090] Since T on is the cycle time, the frequency of the spike bursts is 1/T on . The off time T off , of the multivibrator is defined by
T off =R 9 * C 1 *ln(1+((2 *R 6 )/ R 7 ).
Therefore, if R 8 =R 9 , then the multivibrator will have an equal on and off time. If the transistor is turned off, then the transistor resistor R 9 , effectively becomes infinite and T off therefore becomes infinite and the multivibrator remains disabled. The last pair of operational amplifiers 924 , 926 form another pair of voltage followers as did 906 and 908 , and function as a buffer pair. This again limits the load on the output of the spike burster operational amplifier 922 .
[0091] Again, two are used to get the correct sign on the signal as it travels out of the circuit. The output impedance resistor R 10 sets the output impedance for the spike burster. The value of R 10 must be coordinated with the circuitry downstream from the spike burster. The output of spike bursts exits the circuit at 928 . So using this circuit, the lower threshold voltage V lt 908 and the upper threshold voltage V ut 910 can easily be set as shown in FIGS. 10 and 11 . By using more than one spike burster, the various different activation regions can be created as in FIGS. 10 and 11 .
[0092] The output is evenly spaced apart spikes because of R 8 =R 9 , and there are no partial spikes because of the diode 918 and the resistor R 9 . A counter such as Texas Instruments part number 74HC4040 may be used to count the spikes and output the number of spikes counted to a processor, thereby completing the decoding of the transmitted signal.
[0093] FIG. 20 depicts an exemplary embodiment of a circuit that may be used as a coder for the present communication system. The first capacitor C 1 separates this circuit from the rest of the system and provides instantaneous charge current for circuit operation. This circuit takes digital inputs at 1002 and 1004 . Low voltage or “0” should be inputted at 1002 and high voltage or “1” should be inputted at 1004 . The bilateral switches will transfer an analog or digital signal bidirectionally regardless of polarity once the switch is enabled. The enable connection for the bilateral switch is shown in the figure at the bottom of each switch. When the enable is activated the switch will transfer a signal bidirectionally. The invertors 1006 , 1008 , 1010 , 1012 are used to enable the switched 180 degrees out of phase with each other. When switch 1006 is enabled, switch 1008 is disabled. When switch 1008 is enabled, switch 1006 is disabled. The same applies for switches 1010 and 1012 . Bilateral switch 1006 controls the charging of the capacitor C 2 . Bilateral switch 1010 controls the charging of the capacitor C 3 . The capacitor C 1 should be much greater than the values of C 2 and C 3 . The bilateral switch may be Texas Instruments part number 74HC4066. Capacitors C 2 and C 3 should have different values as this will affect the amplitude of the outgoing analog wave. The greater the value of the capacitor, the greater the amplitude of the outgoing wave. In this way the amplitude of the analog wave corresponding to a “0” will be different (lesser) than the amplitude of the analog wave corresponding to a “1” (greater).
[0094] Whenever C 2 or C 3 is not being discharged, it is being charged and prepared for its next discharge cycle. This allows the piecewise assembly of an analog waveform that corresponds to the 0's and 1's of the input digital wave. Once C 2 and C 3 are charged, the circuit can be forced to discharge either C 2 or C 3 to ground through the resistor R 1 by either inputting a 0 or 1 in at 1002 and 1004 respectively. This circuit will also take inputs of neither a 1 or a 0 or both.
[0095] Therefore, this circuit may encode up to 4 different logic numbers, 00, 0, 1, and 01. Circuits similar to the one depicted in FIG. 19 may be designed to decode all four of these different type of bits, thereby increasing the data rate without increasing bandwidth. The operational amplifiers 1014 and 1016 again form a buffer that allows the output impedance to be defined by R 2 . The operational amplifiers may be National Semiconductor part number LM1458. The power to these amplifiers should be plus and minus 12 volts so that the output wave will not be clipped. The output of this circuit exits at 1018 . The output of this circuit will look similar to a saw-tooth waveform. The capacitors will charge rapidly and discharge at a rate according to the equation
T d =5 e −(t/(50+R2)*C2)
for the portion of the coder that codes the digital 0, where T d is the discharge time.
[0096] Therefore, the discharge time of the capacitor is directly proportional to the value of the capacitor. Therefore, the amount of time it takes for the output analog signal to discharge from peak voltage to a steady low voltage depends directly on the size of the capacitor C 2 . In this way the amount of time the output analog signal spends in a particular activation region can be controlled by the sizes of the capacitors used in this circuit. The same may be done for the portion of the circuit that creates the analog signal that corresponds to the digital 1 by varying the value of C 3 . The circuit in FIG. 19 will output spikes while the analog wave from this circuit has a negative slope and is within the particular activation region of a circuit similar to the one in FIG. 19 . Even in this simple example, more than one bit per wavelength is achieved if the analog wave outputted from this circuit is allowed to descend through more than one activation region of circuits like the one in FIG. 19 .
[0097] FIG. 21 is a schematic of an adaptive counter circuit which may be utilized in a preferred embodiment of the present invention. The input to U 1 A is the USB signal. In an exemplary embodiment the waveform represents a three spike burst. It is not ground referenced and the characteristics of the individual pulses are arbitrary for illustrative purposes only. U 1 A is an inverting unity gain buffer which acts to prevent the circuit from distorting the waveform. This preserves the purity of the waveform. R 3 and C 1 function as an averaging circuit. The change on C 1 provides a rolling average of the inverted signal. A representation of the change on C 1 follows. Note, the sense of this voltage is an inversion from the incoming signal. This voltage is also utilized later for comparison. The first part of this circuit cleans up an analog signal and ground references it, later converting it to a TTL compatible logic signal, U 1 B is an inverting amplifier. Two inversions put the signal back on the positive side of ground. The gain of this amplifier is held to about −1.1. This provides a slight offset from the actual average. This is done to prevent false triggering in the comparator. It raises the reference voltage slightly.
[0098] The output from the comparator is a ground referenced TTL compatible logic signal. It takes the form of a series of pulses with amplitudes of nearly five volts. This becomes the USB′ signal that is fed back into U 3 , the retriggerable monostable multivibrator. The retriggerable feature is important because it allows the counter to be adaptable. U 3 retriggers on each pulse. It times out after waiting 150% of a gap width. The Q output then drops to a low level. The Q signal rises at the end of the time out period. This signal is fed to U 4 , U 4 is sensitive to the rising edge of the signal, U 4 is also a monostable multivibrator but it is not retriggerable, U 4 output is a very narrow pulse. The USB′ pulse train has been fed to the counter U 6 , U 6 is a twelve stage ripple counter. This pulse, the output of U 4 , latches the count to U 5 from U 6 . This pulse also sets the data flag “DATA” by latching the flip flop U 7 .
[0099] U 8 is an inverter pack and is used here to provide a propagation delay. After being delayed, the pulse resets the counter, in preparation for the next burst. The delay prevents resetting the counter before the count is latched to the register U 5 . Thus, it protects the validity of the count.
[0100] In practice, the USB signal is fed to the input. The “DATA” line is tied to a processor interrupt line. The presence of data interrupts whatever processor is monitoring this circuit. That processor reads data on lines D 0 →D 7 by pulling the “OE” line low. It does this in its interrupt handling routine. After reading the data, it clears the data flag by pulling the “CLR” line low. The D 0 →D 7 bus is eight bits wide and conveniently interfaces with a processor bus. The “OE”, “CLR” and “DATA” lines provide the necessary handshaking for the interface. The circuit can be adjusted by changing the timing resistors and capacitors. R 3 and C 1 control the timing of the averaging circuit. Basically, this is done with the consideration that τ=RC where R is in Ohms and C is in Farads. The units of τ are seconds.
[0101] R PXT and C PXT on U 3 control the timeout period for the multivibrator by the equation t w =0.37 RC. T w should be set to 150% of the longest gap width between pulses. In a present exemplary embodiment this circuit is currently wired for 0.001 sec pulses and gaps.
[0102] R P and C P on U 4 provide the width of the latching pulse. Current component choices have set this pulse width to be 100 nsec. The pulse width is given by the equation T w =0.7 R e C e .
[0103] U 8 provides a propagation delay. A series of four inverters provides this delay. An even number of inverters was chosen to preserve the logical sense of the pulse. A delay of about 14 nsec per gate is assumed. The inverter string, then, provides a delay of 56 nsec.
[0104] The present invention provides a method of communication that may increase data rates without a corresponding increase in bandwidth. More than one spike burster may be used to decode a signal. A spike burster's activation region is determined by the circuitry of the particular spike burster. These spike bursters may be designed such that each spike burster has a separate and distinct activation region, and all activation regions together cover the entire region in which the transmitted signal may lie. Each spike burster may output a predetermined number of voltage spikes when the transmitted wave is within the spike burster's activation region. Preferably, voltage spikes may only be outputted by one spike burster at a time. The voltage spikes from the individual spike bursters may be added together, creating distinct, separate spike burst patterns in a voltage spike signal. Then, a digital signal may be created from the pattern of voltage spikes (or their time shift in burst activation). In this way, more than one bit per wavelength may be transmitted and decoded. Therefore, more data may be transmitted and decoded utilizing essentially the same amount of bandwidth.
[0105] The present invention provides a secure method of communication by coding a spike number by a seemingly arbitrary signal going through arbitrarily preset activation and deactivation regions of a spike burster ( FIGS. 2, 3 , 8 , 9 ). It may also do so by coding the activation bursts with arbitrarily preset activation and deactivation thresholds of a spike burster. The present invention gives rise to a method of communication which may measure the phase shift of a modulated sinusoid signal by timing the bursts from an output of a spike burster (see, e.g., FIGS. 15 and 16 ). Such a method may detect orphan data points of a QAM constellation as in FIG. 17 , or data points of an (A,P)-constellation as in FIG. 18 . This facilitates bandwidth efficiency where signal characteristics are comparable to a QAM constellation of a smaller number of states. The present invention provides a method of communication which may be utilized to reduce transmission error rate. This may be accomplished by making use of a modulated sinusoid carrier for redundant symbol retrieving as illustrated ( FIGS. 14, 15 , and 16 ). The present invention also provides a method of control which may use spike burster's input-output control methodology for purposes of synchronization, error detection/correction, data storage, pattern recognition, image segmentation, artificial intelligence of neural networks.
[0106] It is believed that the present invention and many of its attendant advantages may be understood by the foregoing description, and it will be apparent that various changes may be in the form, construction, and arrangement of the components thereof, without sacrificing all of its material advantages. The form herein described being merely an explanatory embodiment thereof, it is the intention of the following claims to encompass and include such changes. | A data communication system is disclosed utilizing a transmitter and one or more receivers. The communication system may increase the data rate without requiring an increase in bandwidth. Additional advantages include an inexpensive encryption property, the incorporation of a simple adaptive synchronization scheme, and the incorporation of an effective error detection and error correction scheme allowing for increased noise and signal degradation. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a sputter mask or stencil used to control deposition of material in a physical vapor deposition (PVD) system. More particularly, the invention relates to a method and apparatus for precise formation of features on the surface of a substrate support chuck used in a process chamber.
2. Background of the Related Art
Substrate support chucks are widely used to support substrates within semiconductor processing systems. A particular type of chuck is a ceramic electrostatic chuck that is used in high-temperature semiconductor processing systems such as high-temperature physical vapor deposition (PVD). These chucks are used to retain semiconductor wafers or other work pieces in a stationary position during processing. Such electrostatic chucks contain one or more electrodes embedded within a ceramic chuck body. The ceramic material is typically aluminum-nitride or alumina doped with a metal oxide such as titanium oxide (TiO 2 ) or some other ceramic material with similar resistive properties.
One disadvantage of using a chuck body fabricated from ceramic is that, during manufacture, the support surface is “lapped” to smooth the ceramic material. Such lapping produces particles that adhere to the support surface. These particles are very difficult to completely remove from the support surface. The lapping process may also fracture the chuck body. Consequently, as the chuck is used, particles are continuously produced by these fractures. Additionally, during wafer processing, the ceramic material can abrade a wafer oxide coating from the underside of the wafer resulting in further introduction of particulate contaminants to the process environment. During use of the chuck, the particles can adhere themselves to the underside of the wafer and be carried to other process chambers or cause defects in circuitry fabrication upon the wafer. It has been found that tens of thousands of contaminant particles can adhere to the backside of a given wafer after retention upon a ceramic electrostatic chuck.
To overcome the disadvantages associated with the workpiece substrate contacting the substrate support chuck, a wafer spacing mask is placed upon the surface of the substrate support chuck. Such a wafer spacing mask is disclosed in commonly assigned U.S. Pat. No. 5,656,093, which is hereby incorporated by reference. The material deposited upon the support surface of the chuck body (i.e., the wafer spacing mask) is a, metal such as titanium, titanium nitride, stainless steel and the like. The material supports a semiconductor wafer in such a way that the surface of the wafer that faces the chuck is spaced apart and substantially parallel to the surface of the chuck. Usually the material is deposited to form a plurality of pads, although any wafer spacing pattern deposited on the surface of the substrate support chuck may be used. Thus, the wafer spacing mask reduces the amount of contaminant particles that adhere to the underside of the wafer.
FIG. 1 depicts a perspective view of a prior art stencil for depositing support surface features. Such stencil is more fully seen and described in U.S. Pat. No. 5,863,396. The above-referenced device is a plate-shaped stencil 100 having a plurality of apertures 108 and a plurality of slots 106 although various other configurations are possible. Material is deposited through the apertures 108 and slots 106 (e.g., via physical vapor deposition) to create the desired surface features on the support surface. The height of such features (i.e., the pads formed by apertures 108 ) must be within 10% of each other to avoid undue flexing and provide uniform support for the wafer to be processed.
FIG. 2 depicts a cross-section as seen along lines 2 — 2 of FIG. 1 of the prior art stencil as placed on top of a surface 210 of a ceramic electrostatic chuck 200 following deposition of the surface features by physical vapor deposition (PVD). As can be seen, some deposited material 206 forms on the stencil. Some deposited material forms support surface features 204 that have larger dimensions than other features 202 . Some features are taller in profile as a result of the “shadowing” effect. The “shadowing” effect is a condition by which PVD material approaching the stencil at angles that are not nearly perpendicular to the stencil is deposited on the sidewalls of the aperture instead of the support surface. Accordingly, this will cause some features to protrude above a desired height “d” from the surface 210 . By mapping the inconsistencies in pad height, it has been ascertained that pads over the outer areas of the substrate support are higher than those radially inward. Unfortunately, this condition is undesirable as it leads to non-uniform substrate support, i.e.; the point of contact of the various features with the wafer will be at different heights. A non-uniform substrate support condition alters the critical temperature profile on the wafer and results in excessive bowing of the wafer during chucking. These undesirable conditions eventually alter the quality of the final product.
Therefore, a need exists in the art for a method and apparatus for fabricating a wafer spacing mask having a plurality of features wherein the plurality of features are formed simultaneously, uniform in profile and wherein the wafer spacing mask can easily be removed from the chuck assembly.
SUMMARY OF THE INVENTION
The disadvantages heretofore associated with the prior art are overcome by a method and apparatus for forming features on a substrate support chuck. The apparatus is a stencil containing a plurality of apertures, each of said apertures having a dual counterbore. The stencil comprises a plate-shaped one-piece structure having a central opening with a plurality of apertures radiating from the central opening outward about the plate-shaped structure. The stencil is preferably fabricated from a ceramic material such as alumina.
A method of forming features on a surface of a substrate support chuck with the stencil comprises the steps of positioning the stencil on the surface of the substrate support chuck; depositing the material onto the stencil and through a plurality of dual counterbored apertures provided in the stencil to form said features upon the surface of the substrate support chuck; removing said stencil and leaving said features upon said surface of said substrate support chuck. The method uses a stencil having a central opening and a plurality of dual counterbored apertures disposed about the plate.
BRIEF DESCRIPTION OF THE DRAWINGS
The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with accompanying drawings, in which:
FIG. 1 depicts a perspective view of a prior art stencil for depositing support surface features;
FIG. 2 depicts a cross-sectional view as seen along lines 2 — 2 of FIG. 1 of the prior art stencil;
FIG. 3 depicts a perspective view of a sputter mask in accordance with the present invention;
FIG. 4 depicts a cross-sectional view of the sputter mask positioned on the surface of a substrate support chuck within a physical vapor deposition system;
FIG. 5A depicts a plan view of a sputter mask in accordance with the present invention; and
FIG. 5B depicts a cross-sectional view along lines 5 B— 5 B of FIG. 5A of the sputter mask according to the present invention.
FIG. 6 depicts a flow chart for producing a sputter mask according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
One solution to forming features having uniform profiles (heights) is shown in FIG. 3 . FIG. 3 shows a sputter mask 300 having a plurality of dual counterbored apertures 308 . For best understanding of the invention, the reader should simultaneously refer to both FIGS. 3 and 4 while reading the following. The sputter mask 300 comprises a plurality of dual counterbored apertures 308 . The plurality of dual counterbored apertures 308 are each comprised of a center bore 306 , a forming aperture 310 on the top of the sputter mask 300 and a release counterbore aperture 312 formed on the bottom 324 of the sputter mask 300 . All of the release apertures 312 along the bottom of the sputter mask 300 are formed having the same dimensions. The release apertures 312 all have the same diameter and the same depth. The forming apertures 310 disposed on the top 323 of the sputter mask 300 penetrate to different depths. Each aperture 308 is created by forming a central bore 306 and disposing a counterbored aperture 310 , also known as the top counterbored hole on the top 323 of the sputter mask 300 . The depth of the top counterbored hole 310 varies as a function of distance beginning at the geometric center 301 of the sputter mask 300 and radiating outward. Illustratively, each of the dual counterbored apertures 308 has on its upper surface 323 a top counterbored hole known as the forming aperture 310 having a diameter of approximately 0.165 inches. Opposite each top counterbored holes 310 on the bottom surface 324 is a bottom counterbored hole known as the release aperture 312 having a diameter of approximately 0.090 inches and a depth of 0.008 inches. Many other sizes and arrangements of apertures are available and all such variations are considered within the scope of the present invention.
As shown in FIG. 4, the specific shape of the sputter mask 300 depends on the shape of the substrate support chuck 402 . Typically, a substrate support chuck 402 is circular, i.e., disk or plate shaped, in plan form, matching the shape of a typical semiconductor wafer as commonly known in the art. The substrate support chuck 402 is generally supported upon a support apparatus 408 . The support apparatus 408 supports the chuck 402 and allows for heating, cooling and retaining a workpiece or substrate upon the surface 404 of the substrate support chuck 402 . To retain a workpiece on the chuck surface 404 , the chuck 402 contains one or more elements 406 for electrostatically clamping the workpiece upon connection to an appropriate power source (not shown). The chuck 402 may also employ a mechanical system for preventing movement or the workpiece (i.e., circumferencially disposed clamp ring or integrated vacuum parts (not shown)). The present invention is applicable to any of the commonly used chuck types. Therefore, the specific nature of the chuck 402 and its operation is irrelevant to the present invention.
The sputter mask 300 is shaped such that when it is placed on the surface of the substrate support chuck 402 , the bottom surface 324 of the sputter mask 300 is supported by the surface 404 of a chuck 402 . In the depicted embodiment, the substrate support chuck 402 contains a flange 416 that extends radially from the central body 401 of the chuck 402 and circumscribes the entire chuck body 401 . As such, the circumferential edge 418 of the chuck body 401 is used to center the sputter mask 300 upon the chuck 402 . Although the sputter mask 300 rests upon the chuck surface 404 , there are areas of the sputter mask 300 that do not contact the surface 404 of the substrate support chuck 402 . In particular, the sputter mask 300 does not contact a surface 420 of the flange 416 . A gap 414 is formed between the flange of the substrate support and the sputter mask 300 . The sputter mask 300 extends beyond the edge of the flange 416 of the support surface to form an overhang 432 . In use, this overhang 432 supports a conventional cover ring 434 .
The sputter mask 300 contains approximately 372 dual counterbored apertures 308 that are arrayed in a pattern of concentric rings. FIGS. 5A and 5B each depict a different view of a sputter mask according to the present invention and it may be helpful to the reader to view both figures simultaneously. FIG. 5A depicts a plan view of a sputter mask in accordance with the present invention. FIG. 5B depicts a vertical cross-sectional view along line 5 B— 5 B of FIG. 5 A. The present embodiment shows the dual counterbored apertures 308 arranged in a plurality of concentric circular patterns 302 radiating from the center 301 . The dual counterbored apertures 308 have forming apertures 310 that vary in depth from approximately 0.062″ in a first circular pattern 302 1 , to approximately 0.065″ in a ninth circular pattern 302 9 . The concentric circular patterns are equidistantly spaced from each other and begin in an area located a distance from the central point 301 . The present embodiment features nine concentric circular patterns. The first concentric circular pattern 302 1 has twelve equally spaced dual counterbored apertures 308 arranged within it. The forming apertures 310 of the first concentric circular pattern 302 1 are bored to a depth of approximately 0.062 inches (see FIG. 5B for detail). Second, third and fourth concentric circular patterns 302 2 , 302 3 and 302 4 respectively, each have twenty-four equally spaced dual counterbored apertures 308 arranged within them. The forming apertures 310 of the second, third and fourth concentric circular patterns are bored to a depth of approximately 0.063 inches respectively. Fifth, sixth and seventh concentric circular patterns 302 5 , 302 6 and 302 7 respectively, each have forty-eight equally spaced dual counterbored apertures 308 arranged within them. In the fifth concentric circular pattern the depth of the forming apertures 310 is approximately 0.063 inches while the depth of the forming apertures 310 for the sixth and seventh concentric circular patterns is approximately 0.064 inches. Lastly, the eighth and ninth concentric circular patterns 302 8 and 302 9 respectively each have 72 equally spaced dual counterbored apertures 308 arranged within them. Both the eighth and ninth concentric circular patterns have forming apertures 310 bored to a depth of approximately 0.065 inches.
Typically, the material of the sputter mask 300 is titanium. Other materials can be used such as silicon, ceramic, aluminum, aluminum nitride and the like. The choice of material depends on the type of system the sputter mask 300 will be used in. For example, in PVD systems, materials that minimize differential thermal expansion such as titanium are the most desirable materials for the sputter mask 300 . Another consideration in choosing sputter mask material is the material that will be sputtered in the system to form deposits on the surface of the substrate support. For example, it is impossible to clean and reuse a titanium mask that has been sputtered with titanium. Therefore, if a reusable mask is desirable, the mask 300 should be fabricated from a different material than that which is being sputtered, e.g., a silicon mask would be appropriate for sputtering titanium.
A method of making the sputter mask 300 is shown in FIG. 6 as a series of method steps 600 . The method begins at step 602 with a blank disk of suitable material such as but not limited to aluminum. In the present embodiment the disk is approximately 0.120 inches thick and approximately eight inches in diameter. It is appreciated by those skilled in the art that these dimensions may vary widely. In step 604 , a plurality of dual counterbored apertures is formed having the characteristics as previously described. The sputter mask is then mounted on a test e-chuck at step 606 . A layer of material is then deposited onto the sputter mask in step 608 . After the deposition process is complete the sputter mask is removed from the test e-chuck at step 610 and measurements are taken at step 612 to determine the non-uniformity distribution parameters. The data taken from the measurements is used to develop and adjust the depth of the forming aperture 310 of the dual counterbored apertures 308 at step 614 as they radiate from the central point. This final adjustment counteracts any of the non-uniformities in the features from the deposition process.
A method of forming deposits on the surface 404 of the substrate support chuck 402 begins with placement of the sputter mask 300 onto the substrate support surface within a PVD system 50 as seen in FIG. 4 . In addition to the chuck 402 , the PVD system contains a chamber 126 (vacuum chamber) containing a vacuum, a cover ring assembly 128 for confining the deposition proximate the chuck, and a target 130 . The PVD system is a conventional system that is operated in a conventional manner to cause sputtering of the target material upon the sputter mask 300 and the exposed support surface 404 of the chuck 402 . The deposition material is a material that bonds to and is thermally compatible with the chuck material. For example, for ceramic chucks, deposition materials include boron-nitride, diamond, oxides, such as aluminum oxide, and metals such as titanium. In general, this technique for patterned deposition of materials is known as lift-off deposition.
To fabricate a sufficient plurality of features, the PVD system deposits a 1 micron layer of material on the substrate support chuck 402 while the sputter mask 300 is positioned on the support surface 404 of the chuck 402 . Deposition material passes through the apertures 308 of the sputter mask 300 onto the surface of the substrate support 404 . Additionally, a second layer of material may be deposited over the first layer for example, an insulator may be first deposited and a conductor deposited thereover. Any number of layers comprising various materials can be deposited using this process. Following the deposition, the target 130 is removed from the chamber 126 such that the sputter mask 300 can be removed from the chuck surface 404 through the top of the PVD system enclosure. The bottom counterbores 312 prevent sticking of the sputter mask 300 to the deposited material of the chuck 402 and provide material deposits having convex (domed) surfaces. The result is a pattern of deposition material atop the chuck surface 404 and the flange surface 420 . The combination of the dual counterbored holes 310 and 312 ensures a uniform (±10% of height of all fixtures) layer of deposited material during the deposition process.
While the foregoing is directed to the preferred embodiment 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. | A method and apparatus for fabricating a wafer spacing mask and a substrate support chuck. Such apparatus is a stencil containing a plurality of dual counterbored apertures that is positioned atop the substrate support chuck while material is deposited onto the stencil and through the apertures' openings onto the chuck. Upon completion of the deposition process, the stencil is removed from the workpiece support chuck leaving deposits of the material of various widths but the same heights to form the wafer spacing mask. | 2 |
This application is a continuation-in-part of U.S. Ser. No. 09/426,981, filed Oct. 26, 1999, which is a continuation of U.S. Ser. No. 08/896,392, filed Jul. 18, 1997, now U.S. Pat. No. 5,979,973, which is a continuation-in-part of U.S. Ser. No. 08/685,678, filed Jul. 24, 1996, now abandoned, which is a continuation-in-part of U.S. Ser. No. 08/506,893, filed Jul. 26, 1995, now U.S. Pat. No. 5,567,000.
BACKGROUND OF THE INVENTION
The present invention relates to pickup trucks, particularly to storage/utility beds for pickup trucks, and more particularly to a storage/utility conversion and method of providing same in a conventional pickup bed without altering the external appearance of the bed.
Pickup trucks have long been a means for transporting and/or storing tools, materials, etc. for various trades, such as plumbing, electrical, construction, repair, etc. While conventional tool boxes, which generally extend across the pickup bed, are a convenient tool storage approach, such take up a great deal of space and thus reduce the carrying capacity. Also, the conventional pickup beds have been removed and replaced with utility type beds of various types, such as exemplified by U.S. Pat. No. 5,267,773 issued Dec. 7, 1993 to G. Kalis, Jr. et al. In addition, the pickup truck body and/or beds have been modified to provide storage/utility space, such as exemplified by U.S. Pat. No. 4,917,430 issued Apr. 17, 1990 to M. A. Lawrence.
While these prior storage/utility arrangements have been satisfactory for their intended purpose, such are an attraction for theft as well as having an appearance of a utility bed. Thus, there has been a need for a storage/utility system for pickup truck beds which does not alter the bed's external appearance or significantly reduce the interior size of the bed, thereby reducing the tool theft problem while providing space for hidden storage without significant reduction of the bed's carrying capacity.
This need has been filled by the present invention which involves the conversion of a conventional pickup truck bed into a storage/utility bed without altering the external appearance of the bed and without significant reduction in the carrying capacity thereof. This is accomplished by providing storage adjacent the wheel well area, and along the length of the bed, and providing the fender/side panel of the bed with a hinge and latch arrangement whereby the fender/side panel can be raised to expose the storage area, or closed and latched to conceal the storage area. Thus, the pickup can be used for pleasure or work without the appearance of its storage/utility capability, and can be parked in areas where theft would likely occur from conventional tool boxes or utility.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a storage/utility system for conventional pickup truck beds.
A further object of the invention is to provide a method for converting a standard pickup truck bed into a storage/utility bed.
A further object of the invention is to provide a pickup truck bed with storage/utility capability without a significant reduction in the carrying capacity thereof.
Another object of the invention is to provide a pickup bed with storage/utility capability without altering the external appearance of the bed.
Another object of the invention is to provide a pickup bed with a hidden storage/utility system wherein the fender/side panel of the bed is hinged to allow access to the storage/utility area.
Another object of the invention is to reduce theft potential from a storage/utility bed of pickup trucks, etc. by providing hidden storage utility areas in the bed without altering the external appearance of the bed.
Other objects and advantages of the invention will become apparent from the following description and accompanying drawings. The invention involves a storage/utility system for pickup truck beds that can be installed in any fleet side bed without altering the bed's appearance. The storage/utility system is installed in the wheel well area of the bed, and uses hinges to open and close the fender/side panel of the bed. The fender/side panel is provided with a latching and lock mechanism. Since the storage/utility system only involves the area of bed adjacent the wheel wells, it does not significantly reduce the carrying capacity of the bed. By providing a hidden storage/utility system for a pickup truck bed, the potential of theft therefrom is substantially reduced since the unaltered appearance of the bed's external surfaces would not lead one to a realization that it contained tools, etc.
Certain embodiments of the present disclosure may therefore be described as storage/utility systems for a bed adapted to be mounted on wheels and having side panels, including a storage box mounted on at least one side of the bed; at least a portion of a side panel on at least one side of the bed being hinged at an upper portion thereof, whereby the hinged portion can be raised to expose an interior of the storage box and lowered to cover the interior of the storage box; and a lock mechanism mounted to releasably secure the side panel. In the described embodiment, the bed preferably includes a pair of wheel wells, and the storage box covers a wheel well and extends forward and/or rearward from the wheel well.
A preferred storage/utility system has a storage box with a height less than a height of the bed, and in certain embodiments, a lock and latch mechanism is mounted to the storage box and may include a plurality of latch members adapted to cooperate with latch members secured to the side panel. It is also an aspect of the present disclosure that a storage box may be provided with at least one shelf therein. In certain embodiments, a portion of a side panel extends substantially an entire length of the bed, and the storage system is formed by a pair of vertical cuts in the overall side panel of the bed adjacent ends of the overall side panel, and is constructed such that when the side panel is lowered the storage box is hidden and the appearance of the bed is not altered.
In certain embodiments of the disclosure, each side of a bed may be provided with a storage box, a lock and latch mechanism, and a hinged side panel. It is also a preferred embodiment that when each side of a bed includes a storage box, that the storage boxes in the bed are positioned in excess of four (4) feet from each other. Various embodiments of the disclosure would also include the described storage/utility systems in which the beds are mounted over the wheels of a pickup, trailer or truck.
In certain embodiments an invention disclosed herein may be described as a method for converting a conventional bed of a vehicle or trailer having wheel wells and side panels into a storage/utility bed without altering the external appearance of the bed. The method would include removing a section of the side panel on at least one side of the bed; hinging the removed side panel section at an upper end thereof to the bed, whereby the side panel section can be raised and lowered; forming storage means along at least one side of the bed so as to cover the wheel wells, whereby raising of the side panel section exposes the interior of the storage means; and providing latching means for side panel section.
In the practice of the described method, removing a section of the side panel may be carried out by making a pair of vertical cuts through the side panel and removing any connection to the bed of the side panel along the lower end thereof. The removed side panel may be hinged, and in certain embodiments a full length hinge is used. The method may further include providing a latch by positioning a plurality of latch mechanisms along the bed and along the side panel section, and providing the storage means with a latch release mechanism and a lock may also be provided. In certain embodiments the latching mechanism is formed to include a release mechanism, preferably by positioning the release mechanism at the rear of the storage means, and connecting the plurality of latch mechanisms to the release mechanism.
In certain embodiments the described method include providing a storage means, a hinged side panel section, and a latching means on each side of the bed; and positioning the storage means in the bed such that there is a space of about four feet between the storage means, and forming the storage means such that the height thereof is less than the height of the bed. Such methods may further include hinging the side panel section such that the hinge is hidden from a side view of the bed, preparing and painting the storage means and exposed surfaces of the side panel section and adjacent bed surfaces to correspond to the paint of the bed, and/or providing the storage means with internal shelving.
Certain embodiments of the invention may also be described as a method for fabricating a storage/utility bed without altering the external appearance thereof, including forming a bed to include a storage box on each side of the bed extending along substantially the length of the bed; forming hinged side panels on the bed such that same can be opened and closed, to expose or cover the storage boxes, and providing latching and lock means for the side panels.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated into and form a part of the disclosure, illustrate an embodiment of the invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 is a view of a side of a pickup truck bed which has been modified to incorporate the storage/utility system under the closed fender/side panel of the bed in accordance with the present invention.
FIG. 2 is an end view of the pickup truck bed of FIG. 1 showing the left fender/side panel open, the right fender/side panel closed, the tail gate open, and the storage boxes and lock mechanism within the bed.
FIG. 3 is a view of an embodiment of the storage/utility system of the FIG. 1 pickup truck bed with the fender/side panel raised to illustrate the storage bin shelves and latch mechanism.
FIG. 4 is a top view of the FIG. 1 pickup truck bed illustrating the storage boxes and fender/side panels, with the tail gate closed.
DETAILED DESCRIPTION OF THE INVENTION
The present invention involves a storage/utility system for a pickup truck bed and a method for conversion of a conventional pickup truck bed to a storage/utility bed without altering the external appearance of the bed, and without a significant reduction in the carrying capacity of the bed. The present invention reduces the theft potential from storage/utility beds by eliminating the appearance of such beds. The invention utilizes lost space adjacent the wheel wells of the bed while maintaining the space between the wheel wells. As known, the space between the wheel wells of a conventional pickup truck bed is slightly over four (4) feet and the conventional pickup truck beds have a length of eight (8) feet plus, wherein sheets of 8 ft. by 4 ft. material, such as plywood, etc. can be carried between the wheel wells. However, the space in front and back of the wheel well is generally considered lost space for large items until material has been stacked above the height of the wheel wells. Thus, by utilizing the area in front, back, and above the wheel wells as storage/utility space, the overall storage/carrying capacity of the bed is increased between the outer fender and inner fender of a stock pickup by removing the inner fender. Here, the term storage/utility space is defined as that space in which tools, such as vices, saws, etc. can be stored or mounted for use, and in which shelves can be secured for retaining parts, etc.
By the present invention, a conventional pickup truck bed is converted to a storage/utility bed, whereas the conventional installation of storage/utility beds involve the replacement of the conventional bed, thus the cost of conversion compared to the cost of the conventional bed replacement is substantially less. Basically, the conversion involves cutting each fender/side panel (hereinafter called side panel) vertically in two places and along the upper length thereof, on an inner surface of the side panel, as described in detail hereinafter, disconnecting the lower length of the side panels from the bed frame, hinging the side panel along the upper length, providing braces on the side panels, installing a latching mechanism along the lower length of the side panels, providing a key lock for the latching mechanism, installing a storage structure or box over the wheel wells along each side of the bed, securing shelving to the storage box, and painting the cut areas and the storage box to correspond to the color of the bed. Upon completion of the conversion, from a side view, the only difference between the converted bed and a nonconverted bed are two vertical lines or small spaces, one just back of the front of the bed and one just forward of the taillight section of the bed, where the side panel is cut, as illustrated in FIG. 1 . The hinge for each side panel is located on an inner area of the side panel so as not to be exposed to one viewing the bed from an external side position. Thus, one would not readily recognize the modification to the bed, and therefore those with intent to steal tools, etc. would not recognize the hidden storage arrangement.
Referring now to the drawings, FIGS. 1 and 2 illustrate a conventionally appearing pickup truck generally indicated at 10 having a cab 11 , bed 12 , frame or undercarriage 13 , and wheels 14 . The bed 12 is mounted on frame or undercarriage 13 and includes side panels 15 , connected to the cab, a taillight arrangement 16 , a hinged tailgate 17 with stop mechanisms 18 , and wheel wells 19 . However, the bed 12 of FIGS. 1 and 2 has been modified in accordance with the present invention, with the only indication of such modification being the cuts, small spaces, or lines 20 and 21 in the side panels 15 , as shown in FIG. 1, with the side panel being closed. Note that in this embodiment the side panels 15 terminate adjacent the frame or undercarriage 13 .
As seen in FIGS. 2, 3 , and 4 , the storage/utility area is provided by storage or structure boxes 22 and 23 mounted within the bed 12 , substantially centered relative to the width of one of the rear wheels and over the wheel wells 19 , the boxes 22 and 23 being constructed to cover the wheel wells 19 , but not extend to the top or upper surface 24 of bed 12 , and terminate in spaced relation to tailgate 17 . The largest horizontal width between side panels 15 of boxes 22 and 23 is not substantially greater than the width of the cab. A latch mechanism 25 is mounted in the rear of each of boxes 22 and 23 , as seen in FIG. 2, and is provided with a key lock 26 . The latch mechanism 25 includes latch members 27 located in spaced relation along the bed 12 , and which cooperate with corresponding latch members 28 in side panel 15 , as show in FIG. 3 . While not shown, the latch members 27 are interconnected by a rod or cable which is connected to mechanism 25 which includes a release for members 27 .
As seen in FIG. 2, the side panels can be contoured such that the distance between the top of one of the side panels and the midline of the bed is less than the distance between the approximate center of the side panels and the midline of the bed. As seen in FIG. 3, the side panels 15 are each provided with braces 29 and a hinge 30 that extends the full length thereof. Shelves 31 and 32 are secured to the interior of storage or structure boxes 22 and 23 , and the area forward of the wheel well 19 forms a storage bin 33 . The hinges 30 are located on the interior of the bed 12 and thus not visible from the exterior.
It has thus been shown that the present invention provides a hidden storage/utility arrangement that can be initially built into a pickup truck bed, or a conventional bed can be converted to include the storage/utility arrangement without altering the external appearance of the bed and without a significant reduction in the carrying capacity of the bed. While the invention has been described with respect to a pickup bed, it can be readily incorporated into trailer or full-sized truck beds having side panels without detracting from the appearance of the side panels, except for the two vertical cuts therein.
While a specific embodiment of the storage/utility system of the present invention has been described and illustrated, such is not intended to limit the invention to this embodiment. For certain applications only one storage box my be desired. Beds for pickups, trailers, and trucks are designed with differently constructed side panels and frame/ undercarriage arrangements. For example, the bed 12 of FIG. 1 may extend downward to cover the frame or undercarriage 13 , as shown, and thus the side panels 15 would include the extended area, or a cut, such as indicated at 34 in FIG. 2, can be made along a desired lower portion of the side panels to eliminate the need for raising the entire side panel when the extended area is part thereof.
Modifications and changes may become apparent to those skilled in the art, and it is intended that the scope of the invention be limited only by the scope of the appended claims. | A pickup truck conversion and method of providing same involves a storage/utility system in any fleet side pickup truck bed without substantially altering the bed's external appearance. The storage system is located adjacent the wheel well sections of the bed, and uses hinges to open and close the fender (side panel) of the bed. Since the storage system does not substantially alter the truck's external appearance, it reduces the attraction for theft. Also, since the storage area does not extend inwardly beyond the conventional wheel wells, the storage system leaves most of the truck bed free for use. | 1 |
BACKGROUND
[0001] Embodiments of the present invention relate to methods and apparatus for harvesting produce. In particular, methods may be utilized for automated trimming and coring operations.
[0002] Modern farming techniques provide many automated methods for harvesting produce. Automated methods have resulted in more efficient utilization of farming resources. For example, automated methods have increased uniformity and quality in produce processing while simultaneously reducing the number of personnel required for accomplishing that production. As a result of automation, delivery of plentiful and low cost products to market is made possible.
[0003] In some farming processes, however, some manual labor is still required. For example, in harvesting delicate produce such as leafy vegetables—hand picking, sorting, and processing is still being utilized in field. In a typical field, numerous personnel are required to maintain harvesting production. As may be appreciated, the costs associated with managing large workforces directly affect market prices. In addition, human error and inconsistency may result, in some examples, in non-uniform production which could adversely affect consumer satisfaction.
[0004] At least one problem associated with harvesting delicate produce automatically is that the produce may be easily damaged. For example, lettuce is one type of delicate produce. During production, lettuce must be sufficiently secured without damaging the leaves which is the end product. In many cases, field processing may be desirable to lower overall production costs, however, equipment must be both sufficiently robust to handle field environments as well as sufficiently sensitive to handle produce without damage—two goals which are often in direct opposition with one another.
[0005] Another problem in harvesting delicate produce automatically is that selection of viable produce is critical. Typically, a laborer examines a head of lettuce to determine whether the produce is viable as a market product. The laborer may then accept or reject the produce before harvesting. However, viability is necessarily a subjective assessment and is thus continually subject to human error. As may be appreciated, these errors may lead either to non-viable product reaching market, or viable product being lost in the field.
[0006] As such produce processing apparatus are presented herein.
SUMMARY
[0007] The following presents a simplified summary of some embodiments of the invention in order to provide a basic understanding of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some embodiments of the invention in a simplified form as a prelude to the more detailed description that is presented below.
[0008] As such, produce trimming apparatus are presented including, including: a number of paddles coupled with a rotating conveyor system configured for capturing and isolating the produce along a first section; a counter-rotating compression belt system for compressing the produce along a second section, where the counter-rotating compression belt system is configured to apply a compressive force to the produce such that the produce is secured, and where the counter-rotating compression belt system includes a belt that is counter-rotating and synchronized with respect to the rotating conveyor system, and a cutting system including a number of cutting blades positioned along a path of the rotating conveyor system, where the number of cutting blades are configured to core and trim the produce along the second section. In some embodiments, apparatus further include: a rinse system along a third section for rinsing a trimmed and cored produce, where the rinse system includes a rinse selected from the group consisting of: a water rinse, a saline rinse, a chemical rinse, and an air rinse. In some embodiments, apparatus further include: a first optical detection device along the first section for detecting viability of the produce, the optical detection device configured to function in coordination with a first produce rejection system along the first section, where the produce is removed from the rotating conveyor system if the produce is not viable; and a second optical detection device along the third section for detecting viability of the produce, the optical detection device configured to function in coordination with a second produce rejection system where the produce is removed from the rotating conveyor system if the produce is not viable. In some embodiments, the produce includes: a romaine lettuce head, an iceberg lettuce head, a butterhead lettuce head, a summertime lettuce head, a cabbage head, a bok choy head, an escarole lettuce head, a radicchio lettuce heat, a broccoli head, a cauliflower head, a broccoflower head, a celery bunch, and a carrot bunch. In some embodiments, the paddles are configured in a shape such as: a planar shape, a multi-planar shape, an arcuate shape, a semi-arcuate shape, and a cupped shape and the number of cutting blades include: a rotating blade, a linear action blade, a static blade, a metal wire blade, a laser blade, and a water blade.
[0009] In other embodiments, methods for coring and trimming a produce are presented including: receiving a severed produce on a rotating conveyor system along a first section, the rotating conveyor system including a number of paddles for capturing and isolating the severed produce; compressing the severed produce with a counter-rotating compression belt system configured to apply a compressive force to the severed produce such that the severed produce is secured; and transporting the severed produce through a cutting system including a number of cutting blades configured to trim and core the severed produce; and releasing a trimmed and cored produce to a collection point. In some embodiments, methods include optically detecting viability of the severed produce before the compressing the severed produce; and rejecting the severed produce if the severed produce is not viable. In some embodiments, methods further include rinsing the trimmed and cored severed produce, where the rinsing includes a rinse such as: a water rinse, a saline rinse, a chemical rinse, and an air rinse.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
[0011] FIG. 1 is an illustrative representation of a perspective view of a produce processing apparatus in accordance with embodiments of the present invention;
[0012] FIG. 2 is an illustrative flowchart of methods for processing produce in accordance with embodiments of the present invention;
[0013] FIGS. 3A-B are illustrative representations of side views of a produce processing apparatus during processing in accordance with embodiments of the present invention;
[0014] FIG. 4 is an illustrative representation of a unit of processed produce in accordance with embodiments of the present invention; and
[0015] FIG. 5 is an illustrative representation of various paddle shapes in accordance with embodiments of the present invention.
DETAILED DESCRIPTION
[0016] The present invention will now be described in detail with reference to a few embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process steps and/or structures have not been described in detail in order to not unnecessarily obscure the present invention.
[0017] FIG. 1 is an illustrative representation of a perspective view of a produce processing apparatus 100 in accordance with embodiments of the present invention. In particular, FIG. 1 is provided to illustrate the various systems required for processing apparatus 100 . As such, processing apparatus 100 includes a plurality of paddles 110 for capturing and isolating severed produce. As illustrated, paddles may be configured, in some embodiments, having a semi-arcuate shape. Referring briefly to FIG. 5 , which is an illustrative representation of various paddle shapes in accordance with embodiments of the present invention, it may be seen that a variety of shapes may be utilized to capture produce. For example, a planar shape 502 , a multi-planar shape 504 and 506 , an arcuate shape 508 , and a cupped shape (not shown) may be utilized without departing from the present invention. Different shapes of paddles may be desirable in processing different types of produce. For example, in embodiments, produce such as a romaine lettuce head, an iceberg lettuce head, a butterhead lettuce head, a summertime lettuce head, a cabbage head, a bok choy head, an escarole lettuce head, a radicchio lettuce heat, a broccoli head, a cauliflower head, a broccoflower head, a celery bunch, and a carrot bunch may be processed utilizing different shaped paddles without limitation. Furthermore, paddles, as utilized herein, may be manufactured from a flexible or semi-flexible polymeric compound in some embodiments. As may be appreciated, a clean and sanitary environment is desirable in food processing systems. As such, some polymeric compounds, such as polyurethane may be useful in providing a sanitary capture device. In other embodiments, a stainless steel paddle may be provided. It may be noted that the illustrated embodiments in FIG. 5 are provided for clarifying embodiments and should not be construed as limiting with respect to dimension, shape, or material.
[0018] Returning to FIG. 1 , produce processing apparatus 100 further includes a conveyor system 112 , which may be utilized for moving produce the various systems. Any conveyor system known in the art may be utilized without departing from the present invention. In addition, conveyance systems may be powered by drives such as: an internal combustion engine, an electric motor, a compressed air motor, a hydraulic fluid motor, a wind turbine motor, and a power take off (PTO) motor without limitation and without departing from the present invention. Produce processing apparatus 100 may be further configured with alignment bar 114 for aligning a produce head in order to properly and accurately process the produce.
[0019] Produce processing apparatus 100 may be further configured with counter-rotating compression belt system 130 . Counter-rotating compression belt system 130 may be configured to apply a compressive force to produce in order to secure the produce. Sufficient compressive forces should be applied to secure the produce without damaging the produce. As may be appreciated, different produce will require different compressive force to obtain production objectives. For example, a head of leafy produce may require less compressive force than a head of dense produce such as broccoli. As such, counter-rotating compression belt system 130 may be configured with an adjustment mechanism for adjusting compressive forces in some embodiments. In some embodiments, a compressive force in a range of approximately 1 to 40 pounds of downward force may be applied to produce by counter-rotating compression belt system 130 . In addition, it may be desirable, in some embodiments, to increase compressive force on produce to account for loss of produce material during processing. As such, compressive force may be increased from a first compressive force in a range of approximately 1 to 40 pounds of downward force to a second compressive force in a range of approximately 5 to 60 pounds of downward force.
[0020] Counter-rotating compression belt system 130 may also be configured to move synchronously with conveyor system 112 . Synchronous movement ensures that produce may be stabilized for processing. However, in other embodiments, asynchronous movement may be desired when processing requires some rotation of the produce. In those asynchronous embodiments, one or more counter-rotating compression belt systems may be utilized to alternately stabilize and rotate produce. Belts utilized in counter-rotating compression belt systems may be manufactured from a flexible or semi-flexible polymeric compound in some embodiments. As may be appreciated, a clean and sanitary environment is desirable in food processing systems. As such, some polymeric compounds, such as polyurethane or TEFLON™ may be useful in providing a belt for use in counter-rotating compression belt systems without limitation. In other embodiments, a non-corrosive metal belt such as stainless steel belt may be provided without limitation. In other embodiments, a metal coated belt may be provided without limitation. In still other embodiments, a rubber or rubberized belt may be provided without limitation. As above, counter-rotating compression belt systems may be powered by drives such as: an internal combustion engine, an electric motor, a compressed air motor, a hydraulic fluid motor, a wind turbine motor, and a power take off (PTO) motor without limitation and without departing from the present invention. In some embodiments, counter-rotating compression belt systems may be mechanically linked to conveyor systems by means of a gear box or chain such that coordinated movement of the systems may be readily achieved.
[0021] Produce processing apparatus 100 may be further configured with a cutting system including a number of cutting blades 120 and 122 for coring and trimming produce. As illustrated blades 120 and 122 are rotating blades. Rotating blades may have some advantages over other methods of processing because blades may be easily serviced to provide clean coring and trimming. In some embodiments, rotating blades may further include a safety shroud (not shown) in order to provide a safe working environment for operators of produce processing apparatus 100 . However, in some embodiments, other methods of coring and trimming may be utilized. For example, in some embodiments, a linear action blade, a static blade, a metal wire blade, a laser blade, and a water blade may be utilized without departing from the present invention. As above, counter-rotating cutting blades may be powered by drives such as: an internal combustion engine, an electric motor, a compressed air motor, a hydraulic fluid motor, a wind turbine motor, and a power take off (PTO) motor without limitation and without departing from the present invention.
[0022] Produce processing apparatus 100 may be further configured with a rinse system (not shown). It may be appreciated that rinsing produce after processing may be desirable to remove cull or other debris such as insects and soil. Thus, any rinse system known in the art may be utilized without departing from the present invention. In addition, any type of rinse may be utilized including a water rinse, a saline rinse, a chemical rinse, and an air rinse without departing from the present invention.
[0023] As produce production becomes more automated, methods of detecting viable produce may be required. In some embodiments, an optical detection device may be utilized to determine viability. These devices may be used before processing when produce is captured by produce processing apparatus 100 , after produce is processed by produce processing apparatus 100 , or both in some embodiments. Utilization of an optical detection device may improve and assure quality control in some embodiments. As such, any optical detection device known in the art may be utilized without departing from the present invention. In addition, a produce rejection system may be utilized in coordination with an optical detection device to remove produce from produce processing apparatus when the produce is not viable. In some embodiments, a produce rejection system may mechanically eject produce from the apparatus. In other embodiments, an alarm may inform an operator that produce is not viable. In still other embodiments, a log may be recorded to track rejected produce.
[0024] When processing is complete, produce may be released from produce processing apparatus 100 at a collection point 140 . At that point, produce may be processed or transported in any number of ways. It may be appreciated that by produce processing apparatus 100 may be utilized in the field or out of field without departing from the present invention. Furthermore, embodiments of produce processing apparatus 100 may be truck mounted, trailer mounted, boom mounted, or tractor mounted without limitation. Still further, embodiments may be utilized in coordination with other automated production machinery such as a harvesting machine without limitation.
[0025] FIG. 2 is an illustrative flowchart 200 of methods for processing produce in accordance with embodiments of the present invention. FIG. 2 will be discussed with FIGS. 3A-B , which are illustrative representations of side views of a produce processing apparatus during processing in accordance with embodiments of the present invention and with FIG. 4 , which is an illustrative representation of a unit of processed produce in accordance with embodiments of the present invention. At a first step 202 , the method receives a severed produce head on a rotating conveyor system. A severed produce head may be received from automated harvesting machinery or from harvesting personnel without limitation. Referring briefly to FIGS. 3A-B and 4 , a produce head 402 is received by rotating conveyor system 310 at 302 . As illustrated, each produce head is isolated. Returning to FIG. 2 , at a next step 204 , produce head is aligned. As noted above, produce processing apparatus embodiments may be configured with an alignment bar for aligning a produce head in order to properly and accurately process the produce. In some embodiments alignment may be manually achieved by operators.
[0026] At a next step 206 , the severed head may be captured by a counter-rotating compression belt system (see 312 , FIGS. 3A-B ). As noted above, counter-rotating compression belt systems may be configured to move synchronously with conveyor systems. Synchronous movement ensures that produce may be stabilized for processing. However, in some embodiments, asynchronous movement may be desired when processing requires some rotation of the produce. At a next step 208 , the method determines whether to reject a severed produce head. As noted above, optical detection systems may be utilized in some embodiments to detect viability of produce. In some embodiments, produce may be inspected by an operator. Therefore, if the method determines at a step 208 to reject a severed produce head, the method continues to a step 210 to eject the severed produce head from the conveyor system whereupon the method ends. If the method determines at a step 208 not to reject a severed produce head, the method continues to a step 212 to transport the severed produce head through a cutting system.
[0027] At a next step 214 , the method trims the severed produce head (see 304 , FIGS. 3A-B , 404 FIG. 4 ). Trimming, as utilized herein removes a top portion of a head. The removed portion is called cull. Trimming may be adjustably configured to remove any amount of cull from the severed head depending on production requirements. Typically, processing removes only portions that may be unsightly or undesirable to a consumer. In some embodiments, trimming removes additional cull by making an angled cut to remove a side portion with respect to the top of the severed head. At a next step 216 , the method cores the severed produce head (see 306 , FIGS. 3A-B ; 406 FIG. 4 ). Coring, as utilized herein, refers to removal of a bottom portion of the head. As above, the removed portion is called cull. Coring may be adjustably configured to remove any amount of cull from the severed head depending on production requirements. In some embodiments, a core may be removed leaving a “V” shaped cut. In other embodiments, a core may be removed leaving a straight cut. In still other embodiments, a core may be removed leaving a semi-arcuate or arcuate cut. As noted above, rotating blades, as illustrated here, may have some advantages over other methods of processing because blades may be easily serviced to provide clean coring and trimming. In some embodiments, rotating blades may further include a safety shroud in order to provide a safe working environment for operators of produce processing apparatus. However, in some embodiments, other methods of coring and trimming may be utilized. For example, in some embodiments, a linear action blade, a static blade, a metal wire blade, a laser blade, and a water blade may be utilized without departing from the present invention.
[0028] It may be appreciated that trimming and coring requirements may depend in part upon the type of produce being processed. As noted above, a number of types of produce may be processed utilizing methods described herein. For example, in embodiments, produce such as a romaine lettuce head, an iceberg lettuce head, a butterhead lettuce head, a summertime lettuce head, a cabbage head, a bok choy head, an escarole lettuce head, a radicchio lettuce heat, a broccoli head, a cauliflower head, a broccoflower head, a celery bunch, and a carrot bunch may be processed without limitation.
[0029] At a next step 218 , the method rinses a trimmed and cored produce head. It may be appreciated that rinsing produce after processing may be desirable to remove cull or other debris such as insects and soil. Thus, any rinse system known in the art may be utilized without departing from the present invention. In addition, any type of rinse may be utilized including a water rinse, a saline rinse, a chemical rinse, and an air rinse without departing from the present invention. At a next step 220 , the method determines whether to reject a trimmed and cored produce head. As noted above, optical detection systems may be utilized in some embodiments to detect viability of produce. In some embodiments, produce may be inspected by an operator. Therefore, if the method determines at a step 220 to reject a trimmed and cored produce head, the method continues to a step 222 to eject the trimmed and cored produce head from the conveyor system whereupon the method ends. If the method determines at a step 220 not to reject a trimmed and cored produce head, the method continues to a step 224 to release the trimmed and cored produce head to a collection point.
[0030] While this invention has been described in terms of several embodiments, there are alterations, permutations, and equivalents, which fall within the scope of this invention. It should also be noted that there are many alternative ways of implementing the methods and apparatuses of the present invention. Furthermore, unless explicitly stated, any method embodiments described herein are not constrained to a particular order or sequence. For example, trimming and coring may be performed in any order without departing from the present invention. Still further, optical scanning of produce may be performed at any stage during production. Further, the Abstract is provided herein for convenience and should not be employed to construe or limit the overall invention, which is expressed in the claims. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations, and equivalents as fall within the true spirit and scope of the present invention. | Produce trimming apparatus are presented including, including: a number of paddles coupled with a rotating conveyor system configured for capturing and isolating the produce along a first section; a counter-rotating compression belt system for compressing the produce along a second section, where the counter-rotating compression belt system is configured to apply a compressive force to the produce such that the produce is secured, and where the counter-rotating compression belt system includes a belt that is counter-rotating and synchronized with respect to the rotating conveyor system; and a cutting system including a number of cutting blades positioned along a path of the rotating conveyor system, where the number of cutting blades are configured to core and trim the produce along the second section. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to a semiconductor structure, and more specifically to a semiconductor structure having no edge placement variation of well implants relative to the isolation structure.
2. Background of the Invention
CMOS technologies continue scale smaller and smaller. As a result parasitic bipolar leakages become harder to control. In traditional process flows, well implants are defined using purely lithographics definition done independently from lithographic steps used for defining physical isolation structures. This independence creates inherent variability.
BRIEF SUMMARY OF THE INVENTION
The following describes a structure and method for alleviating parasitic bipolar leakages in scaled semiconductor technologies. The structure has no edge (or boundary) placement variation for edges of implants under shallow trench isolation (STI) areas, in other words, the distance between the edges of the STI and the corresponding edges or boundaries of implanted wells beneath a given STI are substantially equal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the problem to be solved;
FIG. 2 is demonstrates the various types of parasitic devices which are inadvertently formed;
FIG. 3 is an illustration of the problem and shows advantages offered by the solution;
FIGS. 4A and 4B are each a view of simulation of electrical properties using the prior art solution;
FIG. 5A is a view of an embodiment at a step in a process where a second layer is deposited onto a first substrate. FIG. 5B is a top view of an embodiment of the invention at that step in the process, showing second layer after deposition;
FIG. 6A is a view of an embodiment at another step in the process where a third layer is deposited over the second layer on the substrate. FIG. 6B is a top view of this embodiment of the invention and shows the third layer overlaying the second layer on the substrate;
FIG. 7A illustrates a side view of a structure which has had portions of the top substrate removed using a chemical etch process or other process which provides similar results; FIG. 7B illustrates the result from the top view;
FIG. 8A illustrates a side view of a structure having implants (e.g. n-well, p-well) and an annealing process. The edges or boundaries of the implants are located at a predetermined distances from the planned STI placement; FIG. 8B shows a top view of the structure;
FIG. 9A illustrates a step of depositing a fourth substrate (e.g. nitride) over the second substrate and adjacent to the third substrate and performing a polishing process. FIG. 9B illustrates an example top view of the results of the depositing step;
FIG. 10A illustrates a side view of the structure after removing the third substrate (e.g. Polysilicon). FIG. 10B illustrates a top view of the structure.
FIG. 11A shows the structure after an etch process to remove a portion of the first and second substrates (e.g. silicon and oxide); FIG. 11B shows a top view of the structure;
FIG. 12A shows the structure having a fifth film deposited in the shallow trench isolation (STI) areas. FIG. 12B shows a top view of the structure at this step in the process;
FIG. 13A illustrates an example of the structure having a similar distance between a first implant (or doped) region and an STI and a second implant (or doped) region on the other side of the STI; FIG. 13B shows a top view of the structure shown in FIG. 13A ;
FIG. 14 illustrates a flow diagram of an example process used to make the structure; and
FIG. 15A illustrates an example of the structure having a similar distance and coupled between a first implant (or doped) region and an STI and a second implant (or doped) region on the other side of the STI; FIG. 15B shows a top view of the structure shown in FIG. 15A ;
DETAILED DESCRIPTION
FIG. 1 illustrates a problematic parasitic effect shown as NPN device 130 in structure 100 . NPN device 130 represents a function that occurs when the boundaries between two (or more) implanted (or doped) regions (e.g. Pwell 125 , Nwell 120 , and N+ region 115 ) are touching or very nearly touching. The parasitic effect varies depending on the distance between the adjacent doped regions. In this example, a parasitic effect is created beneath a shallow trench isolation (STI) region 105 at the Nwell 120 and Pwell 125 junction.
FIG. 2 represents the growing complexity of the problem as more devices are manufactured within smaller areas on a wafer (e.g. scaling semiconductor technologies to become smaller and smaller). Structure 200 shows two parasitic devices (npn and pnp) created between an N+ region 225 , Pwell 205 and Nwell 210 ; and P+ region 230 , Nwell 210 and Pwell 205 respectively.
FIG. 3 shows a prior art solution to the parasitics problem as structure 300 . Structure 300 is a hyper-abrupt junction varactor having p+-n junctions 315 , cathode contact 335 , anode contact 330 , an N cathode implant region 320 , Nwells 325 a and 325 b , n+ regions 310 a and 310 b , and STIs 305 a - d . This figure demonstrates the size of the structure required to avoid generation of the variable parasitic devices.
In conventional processing, STI is defined prior to well implants. In some cases, the implants penetrate the side walls of one or more of STIs 305 . FIG. 3A shows ‘n+ii’, ‘P&Nii’, and ‘n+ii’ ion implants, which extend into the STI walls 305 for each device. The small geometries result in narrow anode widths as shown in FIG. 3A . Degradation of an ideality factor is significant for small geometry diodes such as P-n diodes bounded by STIs having implant penetration. An ideality factor is a constant adjustment factor used to correct for discrepancies between an ideal PN junction equation and a measured device.
FIG. 4A shows a simulated degradation of the ideality factor as a function of width. Simulated device 1 shown in FIG. 3 has a width of 1 um resulting in an ideality factor of 1.16 or greater. Device 2 has a width of 0.5 um and a corresponding ideality factor of between 1.13 and 1.15. Likewise, device 3 has a width of 0.25 um and an ideality factor of less than 1.13. The decreasing widths directly correlate with decreasing ideality factors.
FIG. 4B shows a simulation plot for a percent capacitance degradation after 25 hours of stress (reverse bias mode) at 4.5V and 140° C. As the varactor width (in um) increases the percent capacitance change approaches 0% after 25 hours of stress. The reliability degradation of the varactor capacitance is directly proportional to the degradation of the ideality factor.
FIG. 5A shows a side view of a structure 500 having a substrate 510 (for example a layer of silicon such as one used for a wafer), and a film 505 is deposited over substrate 510 (for example a layer of oxide); FIG. 5B shows a top view of structure 500 , which shows film 505 deposited over substrate 510 .
FIG. 6A shows a side view of a structure 600 having a third film 610 (for example a Polysilicon layer) deposited over substrate 510 ; FIG. 6B shows the top view of structure 600 having the top layer of film 610 .
FIG. 7A shows a structure 700 after patterning. The process may include, for example a photolithography step and a subsequent etching step. The process generates structure 700 which shows a patterned film 610 ; FIG. 7B illustrates an example of a top view of structure 700 having the patterned film 610 and the exposed film 505 beneath.
FIG. 8A shows a side view of a structure 800 having been through processing that includes, for example, a well implant step (e.g. ion implant or doping step) and an annealing step. Wells 810 a and 810 b are formed in substrate 510 through, for example, the use of a photomask (not shown) followed by ion implantation, thermal activation, and annealing, and may be, for example, n-wells ( 810 a ) or p-wells ( 810 b ). Substrate 510 , directly beneath film 610 (and corresponding photomasks) is shielded from the implants. The implanting step is followed by an annealing process. In this example implant areas 810 expand during the annealing process such that their edges (or boundaries) are located a predetermined distance from the edges of film 610 ; FIG. 8B shows a top view of structure 800 , which shows films 610 and 505 . Implants 810 are beneath film 505 and their boundaries are shown as dotted lines 810 a and 810 b . The boundaries reside at predetermined distances from the edges of film 610 shown by way of illustration as W 1 , W 2 , W 3 , and W 4 .
FIG. 9A shows structure 900 after several processing steps, for example, a nitride deposition step, and a planarization step such as by chemical mechanical planarization (CMP). Structures 910 (e.g. a nitride) is deposited over film 505 then a step such as a planarization step for example, is used to polish structures 910 to be nearly even with the top of film 610 ; FIG. 9B shows a top view of structure 900 having structures 910 and film 610 visible.
FIG. 10A shows structure 1000 after film 610 has been removed. The patterned film 610 may be removed using a stripping process, for example; FIG. 10B shows a top view of structure 1000 having structures 910 and film 505 .
FIG. 11A shows a side view of structure 1100 where film 505 and substrate 510 have undergone a stripping and/or etching process (for example a reactive ion etching (RIE) process known to those of ordinary skill in the semiconductor manufacturing field) to generate trenches 1110 a and 1110 b (or depressions, channels, etc.). Optionally, additional processing may be implemented at this stage, for example additional ion implant processes; FIG. 11B shows a top view of structure 1100 with exposed substrate 510 , implant areas 810 , and structures 910 .
FIG. 12A shows a side view of a structure 1200 having a material 1210 a and 1210 b , such as an isolation material (e.g. oxide) for example, deposited over structure 1200 to fill-in trenches 1110 a and 1110 b respectively, thereby creating a shallow trench isolation area. A subsequent polishing step (e.g. a CMP) step is used after deposition. FIG. 12B shows a top view of structure 1200 having structures 910 and the isolation materials 1210 in trenches 1110 visible from the top. One edge of trench 1110 b is shown as edge or boundary 1220 , a second boundary of trench 1110 b is shown as boundary 1230 . A first and second boundary of trench 1110 a is shown as boundaries 1240 and 1250 respectively.
FIG. 13B shows a top view of structure 1300 which includes a substrate 510 having the material 1210 a and b (e.g. oxide to create an STI) and at least a first region (e.g. a doped or ion implanted region 810 a ); the trench 1110 a having the first edge or first boundary 1220 (e.g. the side wall or bottom of the trench 1110 b or material 1210 b ); the first region 810 a having a boundary 1320 (e.g. the edge or boundary of the doped region 810 a where it connects to an adjacent substance such as oxide material of 1210 b ); the first region (e.g. the doped region 810 a ) being coupled to (e.g. touching) at least a first portion of the trench 1110 b (e.g. the bottom and/or side of the trench 1110 b or material 1210 b ) such that a portion of the boundary 1320 of the first region 810 a is at a predetermined distance W 1 from the first edge 1220 of trench 1110 b (e.g. with respect to the side of the trench and doped regions as shown as W 1 between elements 810 a and 1210 ).
FIGS. 13A and 13B also show the structure 1300 , having a second region 810 b (e.g. another doped region); the second region 810 b having a second boundary 1330 (e.g. edge) coupled to at least a second portion 1230 of the material 1210 b (e.g. a sidewall and/or bottom of trench 1110 b ) such that a second portion of the second boundary 1330 (e.g. a portion of the boundary around second region 801 b ) is at a second predetermined distance (W 2 ) from a second edge boundary 1230 of trench 1110 b . The predetermined distance, W 1 , and the second predetermined distance W 2 , are substantially similar (e.g. W 1 is about equal to W 2 ).
Likewise, FIGS. 13A and 13B show: the second trench 1110 a having a material 1210 a , a boundary 1240 of trench 1110 a , and a doped region 810 b having a boundary 1340 and adjacent to material 1210 a . The distance between boundaries 1240 and 1340 is shown as W 3 . Region 810 a further has a second boundary 1350 adjacent to a second boundary 1350 of material 1210 a . The distance between boundary 1250 and boundary 1350 is shown as W 4 . Where W 3 and W 4 are substantially equal.
The predetermined distance from the first edge (W 1 ) and the second predetermined distance (W 2 ), may be within, for example, about 10 nm, 10 nm should not be construed as a limitation however. Likewise, the predetermined distance (W 3 ) is equivalent to within 10 nm of the distance (W 4 ).
FIG. 14 shows a flow diagram of a method 1400 of making structure 1300 . Step 1410 : deposit a material film 505 such as a thin oxide for example, over a substrate 510 such as a silicon wafer.
Step 1415 : deposit a second film 610 , such as Polysilicon, adjacent to film 505 ;
Step 1420 : perform photolithography using a reticle and photoresist, which will shield substrate 510 from unwanted implantation and guide self-alignment of the wells 810 to the STIs 1210 ;
Step 1425 : perform an etch process to remove film 610 where any implants 810 are desired;
Step 1430 : implant in the exposed film 505 to generate implant areas or wells 810 ;
Step 1435 : anneal the subsequent structure to evenly expand areas 810 under film 610 ;
Step 1440 : deposit a structure 910 (e.g. nitride) over film 505 ;
Step 1445 : perform a CMP process to even the thickness of structure 910 with film 610 ;
Step 1450 : remove film 610 (e.g. Polysilicon) using a stripping process;
Step 1455 : perform an RIE step on the exposed substrate 510 and film 505 (e.g. oxide and silicon);
Step 1460 : optionally, perform additional implants into exposed substrate 510 ;
Step 1465 : deposit a film such as an oxide to generate isolation regions (STIs) 1210 ;
Step 1470 : perform a CMP process to remove overfill of trenches;
Step 1475 : remove structures 910 (e.g. nitride); and
Step 1480 : perform the process of record (POR). For example, forming FETs and wires to create a functional IC.
FIGS. 15A and 15B show a side and top view of structure 1500 , respectively. Structure 1500 includes a substrate 510 having the material 1210 a and b (e.g. oxide to create an STI) and at least a first region (e.g. a doped or ion implanted region 810 a ); the trench 1110 b having the first edge or first boundary 1220 (e.g. the side wall or bottom of the trench 1110 b or material 1210 b ); the first region 810 a having a boundary 1530 (e.g. the edge or boundary of the doped region 810 a where it connects to an adjacent substance such as oxide material of 1210 b ); the first region (e.g. the doped region 810 a ) being coupled to (e.g. touching) at least a first portion of the trench 1110 b (e.g. the bottom and/or side of the trench 1110 b or material 1210 b ) such that a portion of the boundary 1530 of the first region 810 a is at a predetermined distance W 8 from the first edge 1220 of trench 1110 b (e.g. with respect to the side of the trench and doped regions as shown as W 8 between elements 810 a and 1210 ).
FIGS. 15A and 15B also show the structure 1500 , having a second region 810 b (e.g. another doped region); the second region 810 b having the same boundary 1530 (e.g. edge) as doped region 810 a and coupled to at least a second portion 1230 of the material 1210 b (e.g. a sidewall and/or bottom of trench 1110 b ) such that a second portion of the boundary 1530 (e.g. a portion of the boundary around second region 801 b ) is at a second predetermined distance (W 7 ) from a second edge boundary 1230 of trench 1110 b . The predetermined distance, W 7 , and the second predetermined distance W 8 , are substantially similar and coupled (e.g. W 7 is about equal to W 8 ).
Likewise, FIGS. 15A and 15B show the second trench 1110 a having a material 1210 a , a boundary 1240 of trench 1110 a , and a doped region 810 b having a boundary 1550 and adjacent to material 1210 a . The distance between boundaries 1240 and 1550 is shown as W 6 . Region 810 a further has boundary 1550 adjacent and coupled to a boundary 1250 of material 1210 a . The distance between boundary 1250 and boundary 1550 is shown as W 5 . Where W 5 and W 6 are substantially equal.
It should be apparent to one of ordinary skill in the art that the foregoing description and drawings are meant to provide an illustrative example of developing regions that are self-aligned with edges such as edges of shallow trenches and changes to the structure and process may be modified without departing from the spirit and scope of the invention. | A solution for alleviating variable parasitic bipolar leakages in scaled semiconductor technologies is described herein. Placement variation is eliminated for edges of implants under shallow trench isolation (STI) areas by creating a barrier to shield areas from implantation more precisely than with only a standard photolithographic mask. An annealing process expands the implanted regions such their boundaries align within a predetermined distance from the edge of a trench. The distances are proportionate for each trench and each adjacent isolation region. | 7 |
This application claims the benefit of U.S. Provisional Application Serial No. 60/154,674 filed on Sep. 17, 1999.
BACKGROUND OF THE INVENTION
Tire rubbers which are prepared by anionic polymerization are frequently coupled with a suitable coupling agent, such as a tin halide, to improve desired properties. Tin-coupled polymers are known to improve treadwear and to reduce rolling resistance when used in tire tread rubbers. Such tin-coupled rubbery polymers are typically made by coupling the rubbery polymer with a tin coupling agent at or near the end of the polymerization used in synthesizing the rubbery polymer. In the coupling process, live polymer chain ends react with the tin coupling agent thereby coupling the polymer. For instance, up to four live chain ends can react with tin tetrahalides, such as tin tetrachloride, thereby coupling the polymer chains together.
The coupling efficiency of the tin coupling agent is dependant on many factors, such as the quantity of live chain ends available for coupling and the quantity and type of polar modifier, if any, employed in the polymerization. For instance, tin coupling agents are generally not as effective in the presence of polar modifiers. The amount of coupling which is attained is also, of course, highly dependent upon the quantity of tin coupling agent employed.
Each tin tetrahalide molecule is capable of reacting with up to four live polymer chain ends. However, since perfect stoichiometry is difficult to attain, some of the tin halide molecules often react with less than four live polymer chain ends. For instance, if more than a stoichiometric amount of the tin halide coupling agent is employed, then there will be an insufficient quantity of live polymer chain ends to totally react with the tin halide molecules on a four-to-one basis. On the other hand, if less than a stoichiometric amount of the tin halide coupling agent is added, then there will be an excess of live polymer chain ends and some of the live chain ends will not be coupled.
Conventional tin coupling results in the formation of a coupled polymer which is essentially symmetrical. In other words, all of the polymer arms on the coupled polymer are of essentially the same chain length. All of the polymer arms in such conventional tin-coupled polymers are accordingly of essentially the same molecular weight. This results in such conventional tin-coupled polymers having a low polydispersity. For instance, conventional tin-coupled polymers normally having a ratio of weight average molecular weight to number average molecular weight which is within the range of about 1.01 to about 1.1.
U.S. Pat. No. 5,486,574 discloses dissimilar arm asymmetric radical or star block copolymers for adhesives and sealants. U.S. Pat. No. 5,096,973 discloses ABC block copolymers based on butadiene, isoprene and styrene and further discloses the possibility of branching these block copolymers with tetrahalides of silicon, germanium, tin or lead.
SUMMARY OF THE INVENTION
This invention is based upon the unexpected finding that greatly improved properties for tire rubbers, such as lower hysteresis, can be attained by coupling the rubber with both a tin halide and a silicon halide. For instance, such coupled polymers can be utilized in making tires having greatly improved rolling resistance without sacrificing other tire properties. These improved properties are due in part to better interaction and compatibility with carbon black. It is highly preferred for coupled polymer to be asymmetrically coupled with a tin halide and a silicon halide. Asymmetrical tin coupling also normally leads to improve the cold flow characteristics. Asymmetrical coupling in general also leads to better processability and other beneficial properties.
The coupled rubbery polymers of this invention are comprised of (1) tin atoms having at least three polydiene arms covalently bonded thereto and (2) silicon atoms having at least three polydiene arms covalently bonded thereto. It is highly preferred for the coupled rubbery polymer to be asymmetrically coupled wherein at least one of the polydiene arms bonded to the tin atoms has a number average molecular weight of less than about 40,000, wherein at least one of the polydiene arms bonded to the silicon atoms has a number average molecular weight of less than about 40,000, wherein at least one of said polydiene arms bonded to the tin atoms has a number average molecular weight of at least about 80,000, wherein at least one of said polydiene arms bonded to the silicon atoms has a number average molecular weight of at least about 80,000 and wherein the ratio of the weight average molecular weight to the number average molecular weight of the asymmetrically tin-coupled rubbery polymer is within the range of about 2 to about 2.5.
This invention more specifically discloses a coupled rubbery polymer which is particularly valuable for use in manufacturing tire tread compounds, said coupled rubbery polymer being comprised of (1) tin atoms having at least three polydiene arms covalently bonded thereto and (2) silicon atoms having at least three polydiene arms covalently bonded thereto.
The subject invention further discloses an asymmetrical tin-coupled rubbery polymer which is particularly valuable for use in manufacturing tire tread compounds, said asymmetrical tin-coupled rubbery polymer being comprised of (1) tin atoms having at least three polydiene arms covalently bonded thereto, wherein at least one of said polydiene arms bonded to the tin atoms has a number average molecular weight of less than about 40,000, wherein at least one of said polydiene arms bonded to the tin atoms has a number average molecular weight of at least about 80,000 and (2) silicon atoms having at least three polydiene arms covalently bonded thereto, wherein at least one of said polydiene arms bonded to the silicon atoms has a number average molecular weight of less than about 40,000, wherein at least one of said polydiene arms bonded to the silicon atoms has a number average molecular weight of at least about 80,000 and wherein the ratio of the weight average molecular weight to the number average molecular weight of the asymmetrical coupled rubbery polymer is within the range of about 2 to about 2.5.
This invention also reveals a process for preparing an asymmetrical coupled rubbery polymer which comprises: (1) continuously polymerizing at least one diene monomer to a conversion of at least about 90 percent utilizing an anionic initiator to produce a polymer cement containing living polydiene rubber chains, wherein some of the living polydiene rubber chains are low molecular weight polydiene rubber chains having a number average molecular weight of less than about 40,000 and wherein some of the living polydiene rubber chains are high molecular weight polydiene rubber chains having a number average molecular weight of greater than about 80,000; and (2) continuously adding a tin halide and a silicon halide to the polymer cement in a separate reaction vessel to produce the asymmetrically coupled rubbery polymer, wherein said asymmetrical coupled rubbery polymer has a polydispersity which is within the range of about 2 to about 2.5.
The stability of the asymmetrical tin-coupled rubbery polymers of this invention can be improved by adding a tertiary chelating amine or a salt of a cyclic alcohol thereto subsequent to the time at which the tin-coupled rubbery polymer is coupled. Sodium mentholate is a representative example of a salt of a cyclic alcohol which is preferred for utilization in stabilizing the coupled rubbery polymers of this invention.
DETAILED DESCRIPTION OF THE INVENTION
Virtually any type of rubbery polymer prepared by anionic polymerization can be coupled in accordance with this invention. In fact, the techniques of this invention can be used to asymmetrically couple virtually any type of rubbery polymer synthesized by anionic polymerization. The rubbery polymers which can be asymmetrically coupled will typically be synthesized by a solution polymerization technique utilizing an organolithium compound as the initiator. These rubbery polymers will accordingly normally contain a “living” lithium chain end.
The polymerizations employed in synthesizing the living rubbery polymers will normally be carried out in a hydrocarbon solvent which can be one or more aromatic, paraffinic or cycloparaffinic compounds. These solvents will normally contain from 4 to 10 carbon atoms per molecule and will be liquid under the conditions of the polymerization. Some representative examples of suitable organic solvents include pentane, isooctane, cyclohexane, methylcyclohexane, isohexane, n-heptane, n-octane, n-hexane, benzene, toluene, xylene, ethylbenzene, diethylbenzene, isobutylbenzene, petroleum ether, kerosene, petroleum spirits, petroleum naphtha, and the like, alone or in admixture.
In the solution polymerization, there will normally be from 5 to 30 weight percent monomers in the polymerization medium. Such polymerization media are, of course, comprised of the organic solvent and monomers. In most cases, it will be preferred for the polymerization medium to contain from 10 to 25 weight percent monomers. It is generally more preferred for the polymerization medium to contain 15 to 20 weight percent monomers.
The rubbery polymers which are coupled in accordance with this invention can be made by the homopolymerization of a conjugated diolefin monomer or by the random copolymerization of a conjugated diolefin monomer with a vinyl aromatic monomer. It is, of course, also possible to make living rubbery polymers which can be coupled by polymerizing a mixture of conjugated diolefin monomers with one or more ethylenically unsaturated monomers, such as vinyl aromatic monomers. The conjugated diolefin monomers which can be utilized in the synthesis of rubbery polymers which can be coupled in accordance with this invention generally contain from 4 to 12 carbon atoms. Those containing from 4 to 8 carbon atoms are generally preferred for commercial purposes. For similar reasons, 1,3-butadiene and isoprene are the most commonly utilized conjugated diolefin monomers. Some additional conjugated diolefin monomers that can be utilized include 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl-1,3-octadiene, 2-phenyl-1,3-butadiene, and the like, alone or in admixture.
Some representative examples of ethylenically unsaturated monomers that can potentially be synthesized into rubbery polymers which can be asymmetrically tin-coupled in accordance with this invention include alkyl acrylates, such as methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, and the like; vinylidene monomers having one or more terminal CH 2 ═CH— groups; vinyl aromatics, such as styrene, α-methylstyrene, bromostyrene, chlorostyrene, fluorostyrene, and the like; α-olefins such as ethylene, propylene, 1-butene, and the like; vinyl halides, such as vinylbromide, chloroethane (vinylchloride), vinylfluoride, vinyliodide, 1,2-dibromoethene, 1,1-dichloroethene (vinylidene chloride), 1,2-dichloroethene, and the like; vinyl esters, such as vinyl acetate; α,β-olefinically unsaturated nitriles, such as acrylonitrile and methacrylonitrile; α,β-olefinically unsaturated amides, such as acrylamide, N-methyl acrylamide, N,N-dimethylacrylamide, methacrylamide, and the like.
Rubbery polymers which are copolymers of one or more diene monomers with one or more other ethylenically unsaturated monomers will normally contain from about 50 weight percent to about 99 weight percent conjugated diolefin monomers and from about 1 weight percent to about 50 weight percent of the other ethylenically unsaturated monomers in addition to the conjugated diolefin monomers. For example, copolymers of conjugated diolefin monomers with vinylaromatic monomers, such as styrene-butadiene rubbers which contain from 50 to 95 weight percent conjugated diolefin monomers and from 5 to 50 weight percent vinylaromatic monomers, are useful in many applications.
Vinyl aromatic monomers are probably the most important group of ethylenically unsaturated monomers which are commonly incorporated into polydienes. Such vinyl aromatic monomers are, of course, selected so as to be copolymerizable with the conjugated diolefin monomers being utilized. Generally, any vinyl aromatic monomer which is known to polymerize with organolithium initiators can be used. Such vinyl aromatic monomers typically contain from 8 to 20 carbon atoms. Usually, the vinyl aromatic monomer will contain from 8 to 14 carbon atoms. The most widely used vinyl aromatic monomer is styrene. Some examples of vinyl aromatic monomers that can be utilized include styrene, 1-vinylnaphthalene, 2-vinylnaphthalene, α-methylstyrene, 4-phenylstyrene, 3-methylstyrene, and the like.
Some representative examples of rubbery polymers which can be asymmetrically tin-coupled in accordance with this invention include polybutadiene, polyisoprene, styrene-butadiene rubber (SBR), α-methylstyrene-butadiene rubber, α-methylstyrene-isoprene rubber, styrene-isoprene-butadiene rubber (SIBR), styrene-isoprene rubber (SIR), isoprene-butadiene rubber (IBR), α-methylstyrene-isoprene-butadiene rubber and α-methylstyrene-styrene-isoprene-butadiene rubber. In cases where the rubbery polymer is comprised of repeat units that are derived from two or more monomers, the repeat units which are derived from the different monomers will normally be distributed in an essentially random manner. In other words, the rubbery polymer will not be a block copolymer.
The polymerizations employed in making the rubbery polymer are typically initiated by adding an organolithium initiator to an organic polymerization medium which contains the monomers. Such polymerizations are typically carried out utilizing continuous polymerization techniques. In such continuous polymerizations, monomers and initiator are continuously added to the organic polymerization medium with the rubbery polymer synthesized being continuously withdrawn. Such continuous polymerizations are typically conducted in a multiple reactor system.
The organolithium initiators which can be employed in synthesizing rubbery polymers which can be coupled in accordance with this invention include the monofunctional and multifunctional types known for polymerizing the monomers described herein. The multifunctional organolithium initiators can be either specific organolithium compounds or can be multifunctional types which are not necessarily specific compounds but rather represent reproducible compositions of regulable functionality.
The amount of organolithium initiator utilized will vary with the monomers being polymerized and with the molecular weight that is desired for the polymer being synthesized. However, as a general rule, from 0.01 to 1 phm (parts per 100 parts by weight of monomer) of an organolithium initiator will be utilized. In most cases, from 0.01 to 0.1 phm of an organolithium initiator will be utilized with it being preferred to utilize 0.025 to 0.07 phm of the organolithium initiator.
The choice of initiator can be governed by the degree of branching and the degree of elasticity desired for the polymer, the nature of the feedstock, and the like. With regard to the feedstock employed as the source of conjugated diene, for example, the multifunctional initiator types generally are preferred when a low concentration diene stream is at least a portion of the feedstock, since some components present in the unpurified low concentration diene stream may tend to react with carbon lithium bonds to deactivate initiator activity, thus necessitating the presence of sufficient lithium functionality in the initiator so as to override such effects.
The multifunctional initiators which can be used include those prepared by reacting an organomonolithium compounded with a multivinylphosphine or with a multivinylsilane, such a reaction preferably being conducted in an inert diluent such as a hydrocarbon or a mixture of a hydrocarbon and a polar organic compound. The reaction between the multivinylsilane or multivinylphosphine and the organomonolithium compound can result in a precipitate which can be solubilized, if desired, by adding a solubilizing monomer such as a conjugated diene or monovinyl aromatic compound, after reaction of the primary components. Alternatively, the reaction can be conducted in the presence of a minor amount of the solubilizing monomer. The relative amounts of the organomonolithium compound and the multivinylsilane or the multivinylphosphine preferably should be in the range of about 0.33 to 4 moles of organomonolithium compound per mole of vinyl groups present in the multivinylsilane or multivinylphosphine employed. It should be noted that such multifunctional initiators are commonly used as mixtures of compounds rather than as specific individual compounds.
Exemplary organomonolithium compounds include ethyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-octyllithium, n-eicosyllithium, phenyllithium, 2-naphthyllithium, 4-butylphenyllithium, 4-tolyllithium, 4-phenylbutyllithium, cyclohexyllithium, and the like.
Exemplary multivinylsilane compounds include tetravinylsilane, methyltrivinylsilane, diethyldivinylsilane, di-n-dodecyldivinylsilane, cyclohexyltrivinylsilane, phenyltrivinylsilane, benzyltrivinylsilane, (3-ethylcyclohexyl) (3-n-butylphenyl)divinylsilane, and the like.
Exemplary multivinylphosphine compounds include trivinylphosphine, methyldivinylphosphine, dodecyldivinylphosphine, phenyldivinylphosphine, cyclooctyldivinylphosphine, and the like.
Other multifunctional polymerization initiators can be prepared by utilizing an organomonolithium compound, further-together with a multivinylaromatic compound and either a conjugated diene or monovinylaromatic compound or both. These ingredients can be charged initially, usually in the presence of a hydrocarbon or a mixture of a hydrocarbon and a polar organic compound as a diluent. Alternatively, a multifunctional polymerization initiator can be prepared in a two-step process by reacting the organomonolithium compound with a conjugated diene or monovinyl aromatic compound additive and then adding the multivinyl aromatic compound. Any of the conjugated dienes or monovinyl aromatic compounds described can be employed. The ratio of conjugated diene or monovinyl aromatic compound additive employed preferably should be in the range of about 2 to 15 moles of polymerizable compound per mole of organolithium compound. The amount of multivinylaromatic compound employed preferably should be in the range of about 0.05 to 2 moles per mole of organomonolithium compound.
Exemplary multivinyl aromatic compounds include 1,2-divinylbenzene, 1,3-divinylbenzene, 1,4-divinylbenzene, 1,2,4-trivinylbenzene, 1,3-divinylnaphthalene, 1,8-divinylnaphthalene, 1,3,5-trivinylnaphthalene, 2,4-divinylbiphenyl, 3,5,4′-trivinylbiphenyl, m-diisopropenyl benzene, p-diisopropenyl benzene, 1,3-divinyl-4,5,8-tributylnaphthalene, and the like. Divinyl aromatic hydrocarbons containing up to 18 carbon atoms per molecule are preferred, particularly divinylbenzene as either the ortho, meta or para isomer and commercial divinylbenzene, which is a mixture of the three isomers, and other compounds, such as the ethylstyrenes, also is quite satisfactory.
Other types of multifunctional initiators can be employed such as those prepared by contacting a sec- or tert-organomonolithium compound with 1,3-butadiene, at a ratio of about 2 to 4 moles of the organomonolithium compound per mole of the 1,3-butadiene, in the absence of added polar material in this instance, with the contacting preferably being conducted in an inert hydrocarbon diluent, though contacting without the diluent can be employed if desired.
Alternatively, specific organolithium compounds can be employed as initiators, if desired, in the preparation of polymers in accordance with the present invention. These can be represented by R(Li)x wherein R represents a hydrocarbyl radical containing from 1 to 20 carbon atoms, and wherein x is an integer of 1 to 4. Exemplary organolithium compounds are methyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-octyllithium, n-decyllithium, phenyllithium, 1-naphthyllithium, 4-butylphenyllithium, p-tolyllithium, 4-phenylbutyllithium, cyclohexyllithium, 4-butylcyclohexyllithium, 4-cyclohexylbutyllithium, dilithiomethane, 1,4-dilithiobutane, 1,10-dilithiodecane, 1,20-dilithioeicosane, 1,4-dilithiocyclohexane, 1,4-dilithio-2-butane, 1,8-dilithio-3-decene, 1,2-dilithio-1,8-diphenyloctane, 1,4-dilithiobenzene, 1,4-dilithionaphthalene, 9,10-dilithioanthracene, 1,2-dilithio-1,2-diphenylethane, 1,3,5-trilithiopentane, 1,5,15-trilithioeicosane, 1,3,5-trilithiocyclohexane, 1,3,5,8-tetralithiodecane, 1,5,10,20-tetralithioeicosane, 1,2,4,6-tetralithiocyclohexane, 4,4′-dilithiobiphenyl, and the like.
The polymerization temperature utilized can vary over a broad range of from about −20° C. to about 180° C. In most cases, a temperature within the range of about 30° C. to about 125° C. will be utilized. It is typically preferred for the polymerization temperature to be within the range of about 45° C. to about 100° C. It is typically most preferred for the polymerization temperature to be within the range of about 60° C. to about 85° C. The pressure used will normally be sufficient to maintain a substantially liquid phase under the conditions of the polymerization reaction.
The polymerization is conducted for a length of time sufficient to permit substantially complete polymerization of monomers. In other words, the polymerization is normally carried out until high conversions are attained. The polymerization is then terminated by the addition of a tin halide and a silicon halide. The tin halide and the silicon halide are continuously added in cases where asymmetrical coupling is desired. This continuous addition of tin coupling agent and the silicon coupling agent is normally done in a reaction zone separate from the zone where the bulk of the polymerization is occurring. In other words, the tin coupling agent and the silicon coupling agent will typically be added only after a high degree of conversion has already been attained. For instance, the tin coupling agent and the silicon coupling agent will normally be added only after a monomer conversion of greater than about 90 percent has been realized. It will typically be preferred for the monomer conversion to reach at least about 95 percent before the tin coupling agent and the silicon coupling agent are added. As a general rule, it is most preferred for the monomer conversion to exceed about 98 percent before the coupling agents are added. The coupling agents will normally be added in a separate reaction vessel after the desired degree of conversion has been attained. The coupling agents can be added in a hydrocarbon solution, e.g., in cyclohexane, to the polymerization admixture with suitable mixing for distribution and reaction.
The tin coupling agent will normally be a tin tetrahalide, such as tin tetrachloride, tin tetrabromide, tin tetrafluoride or tin tetraiodide. However, tin trihalides can also optionally be used. Polymers coupled with tin trihalides having a maximum of three arms. This is, of course, in contrast to polymers coupled with tin tetrahalides which have a maximum of four arms. To induce a higher level of branching, tin tetrahalides are normally preferred. As a general rule, tin tetrachloride is most preferred.
The silicon coupling agent will normally be a silicon tetrahalide, such as silicon tetrachloride, silicon tetrabromide, silicon tetrafluoride or silicon tetraiodide. However, silicon trihalides can also optionally be used. Polymers coupled with silicon trihalides having a maximum of three arms. This is, of course, in contrast to polymers coupled with silicon tetrahalides which have a maximum of four arms. To induce a higher level of branching, silicon tetrahalides are normally preferred. As a general rule, silicon tetrachloride is most preferred.
The molar ratio of the tin halide to the silicon halide employed in coupling the rubbery polymer will normally be within the range of 20:80 to 95:5. The molar ratio of the tin halide to the silicon halide employed in coupling the rubbery polymer will more typically be within the range of 40:60 to 90:10. The molar ratio of the tin halide to the silicon halide employed in coupling the rubbery polymer will preferably be within the range of 60:40 to 85:15. The molar ratio of the tin halide to the silicon halide employed in coupling the rubbery polymer will most preferably be within the range of 65:35 to 80:20.
Broadly, and exemplary, a range of about 0.01 to 4.5 milliequivalents of tin coupling agent (tin halide and silicon halide) is employed per 100 grams of the rubbery polymer. It is normally preferred to utilize about 0.01 to about 1.5 milliequivalents of the coupling agent per 100 grams of polymer to obtain the desired Mooney viscosity. The larger quantities tend to result in production of polymers containing terminally reactive groups or insufficient coupling. One equivalent of tin coupling agent per equivalent of lithium is considered an optimum amount for maximum branching. For instance, if a mixture tin tetrahalide and silicon tetrahalide is used as the coupling agent, one mole of the coupling agent would be utilized per four moles of live lithium ends. In cases where a mixture of tin trihalide and silicon trihalide is used as the coupling agent, one mole of the coupling agent will optimally be utilized for every three moles of live lithium ends. The coupling agent can be added in a hydrocarbon solution, e.g., in cyclohexane, to the polymerization admixture in the reactor with suitable mixing for distribution and reaction.
After the coupling has been completed, a tertiary chelating alkyl 1,2-ethylene diamine or a metal salt of a cyclic alcohol can optionally be added to the polymer cement to stabilize the coupled rubbery polymer. The tertiary chelating amines which can be used are normally chelating alkyl diamines of the structural formula:
wherein n represents an integer from 1 to about 6, wherein A represents an alkylene group containing from 1 to about 6 carbon atoms and wherein R 1 , R 2 , R 3 and R 4 can be the same or different and represent alkyl groups containing from 1 to about 6 carbon atoms. The alkylene group A is the formula CH 2 m wherein m is an integer from 1 to about 6. The alkylene group will typically contain from 1 to 4 carbon atoms (m will be 1 to 4) and will preferably contain 2 carbon atoms. In most cases, n will be an integer from 1 to about 3 with it being preferred for n to be 1. It is preferred for R 1 , R 2 , R 3 and R 4 to represent alkyl groups which contain from 1 to 3 carbon atoms. In most cases, R 1 , R 2 , R 3 and R 4 will represent methyl groups.
The metal salts of the cyclic alcohols that can be used will typically be a Group Ia metal salts. Lithium, sodium, potassium, rubidium and cesium salts are representative examples of such salts with lithium, sodium and potassium salts being preferred. Sodium salts are typically the most preferred. The cyclic alcohol can be mono-cyclic, bi-cyclic or tri-cyclic and can be aliphatic or aromatic. They can be substituted with 1 to 5 hydrocarbon moieties and can also optionally contain hetero-atoms. For instance, the metal salt of the cyclic alcohol can be a metal salt of a di-alkylated cyclohexanol, such as 2-isopropyl-5-methylcyclohexanol or 2-t-butyl-5-methylcyclohexanol. These salts are preferred because they are soluble in hexane. Metal salts of disubstituted cyclohexanol are highly preferred because they are soluble in hexane. Sodium mentholate is the most highly preferred metal salt of a cyclic alcohol that can be employed in the practice of this invention. Metal salts of thymol can also be utilized. The metal salt of the cyclic alcohol can be prepared by reacting the cyclic alcohol directly with the metal or another metal source, such as sodium hydride, in an aliphatic or aromatic solvent.
A sufficient amount of the chelating amine or metal salt of the cyclic alcohol should be added to complex with any residual tin coupling agent remaining after completion of the coupling reaction.
In most cases, from about 0.01 phr (parts by weight per 100 parts by weight of dry rubber) to about 2 phr of the chelating alkyl 1,2-ethylene diamine or metal salt of the cyclic alcohol will be added to the polymer cement to stabilize the rubbery polymer. Typically, from about 0.05 phr to about 1 phr of the chelating alkyl 1,2-ethylene diamine or metal salt of the cyclic alcohol will be added. More typically, from about 0.1 phr to about 0.6 phr of the chelating alkyl 1,2-ethylene diamine or the metal salt of the cyclic alcohol will be added to the polymer cement to stabilize the rubbery polymer.
After the polymerization, coupling and, optionally, the stabilization step has been completed, the coupled rubbery polymer can be recovered from the organic solvent. The coupled rubbery polymer can be recovered from the organic solvent and residue by means such as decantation, filtration, centrification, and the like. It is often desirable to precipitate the coupled rubbery polymer from the organic solvent by the addition of lower alcohols containing from about 1 to about 4 carbon atoms to the polymer solution. Suitable lower alcohols for precipitation of the rubber from the polymer cement include methanol, ethanol, isopropyl alcohol, normal-propyl alcohol and t-butyl alcohol. The utilization of lower alcohols to precipitate the asymmetrically tin-coupled rubbery polymer from the polymer cement also “kills” any remaining living polymer by inactivating lithium end groups. After the coupled rubbery polymer is recovered from the solution, steam-stripping can be employed to reduce the level of volatile organic compounds in the coupled rubbery polymer.
The coupled rubbery polymers that can be made by using the technique of this invention are comprised of tin atoms having at least three polydiene arms covalently bonded thereto and silicon atoms having at least three polydiene arms covalently bonded thereto. In the case of asymmetrically coupled rubbery polymers made by the technique of this invention, at least one of the polydiene arms bonded to the tin atoms has a number average molecular weight of less than about 40,000, at least one of the polydiene arms bonded to the tin atom has a number average molecular weight of at least about 80,000, at least one of the polydiene arms bonded to the silicon atoms has a number average molecular weight of less than about 40,000 and at least one of the polydiene arms bonded to the silicon atoms has a number average molecular weight of at least about 80,000. The ratio of the weight average molecular weight to the number average molecular weight of the asymmetrically coupled rubbery polymer will also be within the range of about 2 to about 2.5.
The asymmetrically coupled rubbery polymers of this invention contain stars of the structural formula:
wherein M represents silicon or tin, wherein R 1 , R 2 , R 3 and R 4 can be the same or different and are selected from the group consisting of alkyl groups and polydiene arms (polydiene rubber chains), with the proviso that at least three members selected from the group consisting of R 1 , R 2 , R 3 and R 4 are polydiene arms, with the proviso that at least one member selected from the group consisting of R 1 , R 2 1 R 3 and R 4 is a low molecular weight polydiene arm having a number average molecular weight of less than about 40,000, with the proviso that at least one member selected from the group consisting of R 1 , R 2 , R 3 and R 4 is a high molecular weight polydiene arm having a number average molecular weight of greater than about 80,000 and with the proviso that the ratio of the weight average molecular weight to the number average molecular weight of the asymmetrical tin-coupled rubbery polymer is within the range of about 2 to about 2.5. It should be noted that R 1 , R 2 , R 3 and R 4 can be alkyl groups because it is possible for the tin halide coupling agent to react directly with alkyl lithium compounds which are used as the polymerization initiator. The ratio of silicon containing stars to tin containing stars will be within the range of about 20:80 to about 80:20.
In most cases, four polydiene arms will be covalently bonded to the tin atom or the silicon atom in the asymmetrical tin-coupled rubbery polymer. In such cases, R 1 , R 2 , R 3 and R 4 will all be polydiene arms. The asymmetrical tin-coupled rubbery polymer will often contain a polydiene arm of intermediate molecular weight as well as the low molecular weight arm and the high molecular weight arm. Such intermediate molecular weight arms will have a molecular weight which is within the range of about 45,000 to about 75,000. It is normally preferred for the low molecular polydiene arm to have a molecular weight of less than about 30,000 with it being most preferred for the low molecular weight arm to have a molecular weight of less than about 25,000. It is normally preferred for the high molecular polydiene arm to have a molecular weight of greater than about 90,000 with it being most preferred for the high molecular weight arm to have a molecular weight of greater than about 100,000. The arms of the coupled polymer will typically be either homopolymers or random copolymers. In other words, the arms of the coupled polymers will normally not be block copolymers.
This invention is illustrated by the following examples which are merely for the purpose of illustration and are not to be regarded as limiting the scope of the invention or the manner in which it can be practiced. Unless specifically indicated otherwise, parts and percentages are given by weight.
Benefits with tin-coupled IBRs, as compared to the linear IBRs, are demonstrated by the following examples. These benefits include:
(1) Improvements in processability, particularly extrudability/extrudate quality.
(2) Treadwear improvement and rolling resistance reduction due to improved carbon black dispersion with the tin-coupled IBR. Good dispersion of carbon black prevents carbon particles from forming a network of carbon black in the vulcanizate and reduces hysteresis resulting from carbon black aggregates. This is known as Payne effect. The higher the Payne effect, the better the carbon black dispersion. The Payne effect can be measured as follows: Payne effect = G ′ at 10 % strain G ′ at 1 % strain × 100
EXAMPLE 1
In this experiment, a tin-coupled isoprene-butadiene rubber was prepared at 70° C. In the procedure used, 2300 g of a silica/alumina/molecular sieve dried premix containing 19.5 weight percent isoprene/1,3-butadiene mixture in hexanes was charged into a one-gallon (3.8 liters) reactor. The ratio of isoprene to 1,3-butadiene was 30:70. After the amount of impurity in the premix was determined, 4.50 ml of 1.04 M solution of n-butyllithium (in hexanes) was added to the reactor. The target Mn (number averaged molecular weight) was 100,000. The polymerization was allowed to proceed at 70° C. for 4 hours. The GC analysis of the residual monomers contained in the polymerization mixture indicated that most of the monomers were converted to polymer. After a small aliquot of polymer cement was removed from the reactor (for analysis), 2.0 ml of a 0.6 M solution of tin tetrachloride (in hexanes) was added to the reactor and the coupling reaction was carried out the same temperature for one hour. At that time, 1.0 phr (parts per 100 parts of rubber by weight) of BHT (2,6-di-tert-butyl-4-methylphenol) was added to the reactor to shortstop the polymerization and to stabilize the polymer. After evaporating the hexanes, the resulting polymer was dried in a vacuum oven at 50° C. The coupled isoprene-butadiene rubber (IBR) produced was determined to have a glass transition temperature (Tg) at −89° C. It was also determined to have a microstructure which contained 5.7 percent 1,2-polybutadiene units, 64.6 percent 1,4-polybutadiene units, 28.5 percent 1,4-polyisoprene and 1.2 percent 3,4-polyisoprene. The Mooney viscosity (ML-4) at 100° C. for this coupled polymer was also determined to be 80. Based on GPC measurement, the coupling efficiency was 90 percent.
EXAMPLES 2-5
The product described in Example 1 was utilized in these experiments, except that a mixture of tin tetrachloride and silicon tetrachloride was used as the coupling agent. The molar ratios of tin tetrachloride to silicon tetrachloride in these mixtures were 85:15, 75:25, 65:35 and 55:45. The Mooney viscosities and microstructures of these IBRs are shown in Table I. The coupling efficiency for all these IBRs were 90 percent, based on GPC measurement, and the glass transition temperature of all of the polymers made was −89° C.
TABLE I
Ex.
Sn/Si
ML-4
1,2-PBd
1,4-PBd
1,4-PI
3,4-PI
1
100/0
80
5.7%
64.6%
28.5%
1.2%
2
85/15
85
5.6%
64.7%
28.5%
1.2%
3
75/25
87
5.6%
64.7%
28.5%
1.2%
4
65/35
86
5.7%
64.6%
28.4%
1.3%
5
55/45
83
5.7%
64.4%
28.6%
1.3%
EXAMPLE 6
The coupled IBRs made in Examples 1-5 were compounded in a model formulation by mixing them with the ingredients shown in Table II. The tan delta valued at 11 Hz at varied temperatures and stains are reported in Table III. As indicated in Table III, the polymer made in Example 3, which utilized a 75:25 mixture of tin tetrachloride to silicon tetrachloride as the coupling agent, exhibited the lowest tan delta values at 40-100° C. at all strain levels. This indicates that it will have the lowest compound hysteresis when used as a tire tread compound.
TABLE II
Materials
phr
polymer
100
carbon black
40
process oil
4
wax
2
stearic acid
1.5
zinc oxide
3
antioxidant
1
accelerator
0.11
curative
1.3
sulfur
1.3
TABLE III
Tan Delta Values
Temp & Strain
1
2
3
4
5
40° C. @ 1% strain
.080
.084
.072
.077
.085
100° C. @ 5% strain
.075
.074
.066
.068
.082
100° C. @ 50% strain
.060
.058
.055
.056
.062
Variations in the present invention are possible in light of the description of it provided herein. While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. It is, therefore, to be understood that changes can be made in the particular embodiments described which will be within the full intended scope of the invention as defined by the following appended claims. | It has been unexpectedly found that greatly improved properties for tire rubbers, such as lower hysteresis, can be attained by coupling the rubber with both a tin halide, such as tin tetrachloride, and a silicon halide, such as silicon tetrachloride. Even better characteristics for use in tire tread compounds can be realized by asymmetrically coupling the rubbery polymer. This invention more specifically discloses a coupled rubbery polymer which is particularly valuable for use in manufacturing tire tread compounds, said coupled rubbery polymer being comprised of (1) tin atoms having at least three polydiene arms covalently bonded thereto and (2) silicon atoms having at least three polydiene arms covalently bonded thereto. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method for synthesizing an organic substance using supercritical water, in particular, a method for synthesizing acrolein, which is a raw material for 1,3-propanediol, from glycerin in the presence of proton.
[0003] 2. Background Art
[0004] Recently, demand for 1,3-propanediol has been increased because 1,3-propanediol is a raw material for high quality polyester fibers including polytrimethylene terephthalate. One of the methods for synthesizing 1,3-propanediol is a method for hydrating and hydrogenating acrolein shown in “Production, applications and economic efficiency of 1,3-PDO and PTT, CMC Co., Ltd., Planet Division, August, 2000.” This method produces 1,3-propanediol by hydration and hydrogenation reactions of acrolein obtained by air oxidation of propylene, which is a petroleum-based raw material, in the presence of a catalyst; this method is established as an industrial method. However, because of the recent increase in the price of crude oil, development of methods for synthesizing 1,3-propanediol from biological raw materials has been demanded.
[0005] There has not been reported any synthesis method of chemically synthesizing 1,3-propanediol from biological raw materials; however, there are techniques for synthesizing acrolein, which is a precursor of 1,3-propanediol, and examples of such techniques include a technique described in “WATANABE Masaru, IIDA Tom, AIZAWA Yuichi, AIDA Taku M, INOMATA Hiroshi, Acrolein synthesis from glycerol in hot-compressed water, Bioresource Technology 98, 1285-1290 (2007).” This method is a method in which, by using a small-scale apparatus such that the pipe diameter is of the order of 1 mm and the flow rate is 10 to 50 ml/min, an aqueous solution of glycerin as a biological raw material and high-temperature supercritical water are mixed with each other at 35 MPa, and thus the temperature of the resulting mixture is instantly increased to 400° C. to synthesize acrolein (the optimal reaction time is about 20 seconds). This method is characterized in that the proton originating from sulfuric acid added in a small amount to the aqueous solution of glycerin functions as a catalyst accelerating the dehydration reaction of glycerin. However, in “WATANABE Masaru, IIDA Toru, AIZAWA Yuichi, AIDA Taku M, INOMATA Hiroshi, Acrolein synthesis from glycerol in hot-compressed water, Bioresource Technology 98, 1285-1290 (2007),” the glycerin concentration in the raw material is as low as about 1%, and a large amount of energy is consumed for the temperature increase and pressure increase of water, and hence, for the purpose of commercial manufacturing, it is necessary to increase the glycerin concentration in the reaction solution to a high concentration of at least 15% or more.
[0006] However, when the glycerin concentration is increased to 15% or more, the reaction rate comes to be high and the optimal reaction time comes to be a few seconds, and hence complete mixing is required to be completed in at least 1/10th the reaction time. On the other hand, with the increase of the glycerin concentration, the viscosity difference between the supercritical water and the aqueous solution of glycerin is increased, and accordingly the miscibility therebetween is degraded. In particular, in a commercial plant of a size of a few ten thousands t/y, in the case where the reaction solutions are mixed at an economic flow speed, the pipe diameter comes to be about 1 to 10 cm, and concomitantly, the diffusion distance is also increased. In this connection, the mixing time is reciprocally proportional to the square of the pipe diameter, and hence the mixing time comes to be a few seconds or more. When the miscibility is degraded, the coordination number of the supercritical water in the vicinity of the glycerin molecules is degraded. FIG. 1 shows the dehydration reaction route of glycerin on the basis of the use of supercritical water. When the coordination number is decreased, the side reaction proceeds more predominantly than the main reaction to produce acrolein, and hence the reaction yield of acrolein is degraded. Additionally, with the decrease of the miscibility, glycerin is brought into contact with supercritical water to react with supercritical water at a temperature higher than the optimal reaction temperature, and hence the amounts of the generated reaction by-products such as tar and carbon particles are increased to further decrease the yield. The carbon particles aggregated with the aid of tar adhere to the valving elements and valve seats. Consequently, abrasion or the like of the valving elements and the valve seats occurs, and the operation ranges of the valving elements are limited to lead to a possibility that precise pressure control is made difficult. Therefore, from the viewpoints of the increase of the glycerin concentration and the scale-up of the reaction, the improvement of the miscibility is required.
[0007] In JP Patent Publication (Kokai) No. 2006-167600, a method for improving the miscibility is reported. In this method, the introduction pipe of a first fluid and the introduction pipe of a second fluid are connected to the mixing pipe under the condition that the central axis of the introduction pipe of the first fluid and the central axis of the introduction pipe of the second fluid are deviated from each other, and thus swirl flow is generated in the mixing pipe to thereby improve the miscibility. However, the number of the introduction pipes is small, and hence a high miscibility is obtained with the thin pipe of the order of millimeters in the diameter of the mixing pipe, but in a case of a commercial plant of the order of a few ten thousands t/y having a mixing pipe diameter of the order of 10 cm, no sufficient miscibility is obtained.
[0008] On the other hand, in the high-temperature, high-pressure micromixer described in JP Patent Publication (Kokai) No. 2008-12453, a first reaction solution is introduced into the central axis of a mixing pipe and two introduction pipes of a second reaction solution are disposed at the positions offset from the central axis, and hence there is a problem that a multiple layer flow is hardly formed and the mixing time is made long.
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to provide a method for commercially manufacturing acrolein in a large flow rate by making supercritical water and an acid interact with glycerin, wherein by efficiently mixing high-concentration glycerin and supercritical water with each other, the method is made capable of making the synthesis stably proceed with a high yield while the occlusion and abrasion of the pipes and devices due to the generation of by-products are being suppressed.
[0010] The present invention is characterized in that, for the purpose of solving the above-described problems, in a method for synthesizing acrolein by making supercritical water and an acid interact with glycerin, the method uses a reaction apparatus including: a cylindrical mixing flow path for mixing a fluid containing glycerin and a fluid containing supercritical water with each other; a first inlet flow path, disposed offset from the central axis of the mixing flow path, for making the fluid containing glycerin flow into the mixing flow path; and a second inlet flow path, disposed offset from the central axis of the mixing flow path, for making the fluid containing supercritical water flow into the mixing flow path, wherein the first inlet flow path and the second inlet flow path are each provided in a plurality of numbers in such a way that the first inlet flow paths and the second inlet flow paths are alternately arranged so as to encircle the central axis of the mixing flow path. Here, applicable as the acid are sulfuric acid, diluted sulfuric acid, solid acid catalysts and the like.
[0011] The present invention is also characterized in that in a method for synthesizing acrolein by making supercritical water and an acid interact with glycerin, the method uses a reaction apparatus including: a cylindrical mixing flow path for mixing a fluid containing glycerin and a fluid containing supercritical water with each other; a first inlet flow path, disposed offset from the central axis of the mixing flow path, for making the fluid containing glycerin flow into the mixing flow path; and a second inlet flow path, disposed offset from the central axis of the mixing flow path, for making the fluid containing supercritical water flow into the mixing flow path, wherein the first inlet flow path and the second inlet flow path are each provided in a plurality of numbers along the flow direction of the mixing flow path so as to be separated away from each other.
[0012] The present invention is also characterized in that a structure is disposed on the central axis of the mixing flow path.
[0013] The present invention is also characterized in that the structure disposed on the central axis of the mixing flow path is formed in such a way that the cross sectional area of the structure is made smaller toward the downstream of the mixing flow path.
[0014] The present invention is also characterized in that between the flow rate Q X and the cross sectional area S X per one of the first inlet flow paths and the flow rate Q Y and the cross sectional area S Y per one of the second inlet flow paths, the relation represented by the formula (1) is satisfied, and the flow speeds at the inlet flow paths are equal to each other.
[0000] Q X /S X =Q Y /S Y (1)
[0015] The present invention is also characterized in that the method for synthesizing acrolein performs the synthesis by installing in combination a plurality of such reaction apparatuses as described above.
[0016] The present invention is also characterized in that in a method for synthesizing acrolein by making supercritical water and an acid interact with glycerin, the method uses a reaction apparatus including: a cylindrical mixing flow path for mixing a fluid containing glycerin and a fluid containing supercritical water with each other; a first inlet flow path, connected to the mixing flow path, for making the fluid containing glycerin flow into the mixing flow path; and a second inlet flow path, connected to the mixing flow path, for making the fluid containing supercritical water flow into the mixing flow path, wherein a static mixer is disposed in the mixing flow path.
[0017] The present invention is also characterized in that in a method for synthesizing acrolein by making supercritical water and an acid interact with glycerin, the method uses a reaction apparatus including: a cylindrical mixing flow path for mixing a fluid containing glycerin and a fluid containing supercritical water with each other; a first inlet flow path, connected to the mixing flow path, for making the fluid containing glycerin flow into the mixing flow path; and a second inlet flow path, connected to the mixing flow path, for making the fluid containing supercritical water flow into the mixing flow path, wherein a perforated plate is disposed in the mixing flow path.
[0018] The present invention is also characterized in that in a method for synthesizing at least one selected from acrolein, glucose and hydroxymethylfurfural by making at least one of supercritical water and subcritical water interact with a raw material containing at least one selected from glycerin, cellulose and lignin, the method uses a reaction apparatus including: a cylindrical mixing flow path for mixing a fluid containing the raw material and a fluid containing at least one of supercritical water and subcritical water with each other; a first inlet flow path, disposed offset from the central axis of the mixing flow path, for making the fluid containing the raw material flow into the mixing flow path; and a second inlet flow path, disposed offset from the central axis of the mixing flow path, for making the fluid containing at least one of supercritical water and subcritical water flow into the mixing flow path, wherein the first inlet flow path and the second inlet flow path are each provided in a plurality of numbers in such a way that the first inlet flow paths and the second inlet flow paths are alternately arranged so as to encircle the central axis of the mixing flow path.
[0019] According to the present invention, the fluid containing glycerin and the fluid containing supercritical water can be mixed with each other in the mixing flow path with the aid of swirl flow, and at the same time, two different types of fluids can be made to flow in multiple layers (preferably, each fluid is made to flow in four directions to form swirl flow, and thus in optimal eight layers), and hence the diffusion distance between the two types of fluids can be reduced, and the miscibility can be improved.
[0020] Because a structure is disposed on the central axis of the mixing flow path, no mixing solutions are made to present in the vicinity of the central axis. Although the mixing with the aid of swirl flow generates a partial region low in miscibility on the central axis of the mixing flow path, the above-described contrivance suppresses the occurrence of such a region to improve the miscibility. Additionally, by disposing the structure, the distance between the mixing flow path and the structure is made small and the interlayer distances in the multiple layer flow are reduced and hence the miscibility can be improved.
[0021] Additionally, because a plurality of the reaction apparatuses utilizing swirl flow are installed in combination (numbering-up), the miscibility improvement and the pressure reduction can be made compatible with each other.
[0022] Such a miscibility improving measure as described above enables a commercial plant of a scale of 100,000 t/y, in which the inner diameter of the mixing pipe is large, to attain a sufficient miscibility, and hence the reaction yield is improved and the amounts of generated tar and the generated by-products can be reduced. Accordingly, the occlusion of the pipes and valves due to the adhesion of the by-products can be prevented. Further, the abrasion of the valving elements and the valve seats are suppressed, and hence the precise pressure control can be performed. Therefore, highly efficient operation of the commercial plant is made possible.
[0023] The constitution of the present invention as described above can be applied not only to the case where the raw material is glycerin but also to the case where other biomass resources such as cellulose and lignin are used as the raw materials and are made to react with supercritical water or subcritical water. In this regard, it is preferable that the raw materials such as cellulose and lignin be mixed, before being subjected to the reaction, with subcritical water offering relatively mild conditions and be dissolved in subcritical water. In the case where cellulose is used as the raw material, by making subcritical water being smaller in the action of proton (decomposition action) in place of supercritical water and a dehydrating agent such as acetic anhydride in place of sulfuric acid interact with cellulose, glucose and hydroxymethylfurfural (one of the intermediates of medicinal chemicals) are synthesized. In the case where lignin is used as the raw material, by making the oxidant such as hydrogen peroxide in place of subcritical water and sulfuric acid interact with lignin, succinic acid (one of the raw materials for polybutylene succinate, a bioplastic) is synthesized. In each case, by improving the miscibility between subcritical water and the raw material on the basis of the present invention, the yield improvement and the prevention of the drawbacks such as the occlusion due to the by-products can be realized.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a diagram showing the dehydration reaction path of glycerin using supercritical water.
[0025] FIG. 2 is a view illustrating an embodiment of an apparatus for synthesizing acrolein, using supercritical water.
[0026] FIG. 3 is an oblique perspective view of a reaction apparatus utilizing swirl flow in the present invention.
[0027] FIG. 4 is a front view and a plan view of a reaction apparatus utilizing swirl flow in the present invention.
[0028] FIG. 5 is a front view and a plan view of a reaction apparatus utilizing swirl flow in the present invention.
[0029] FIG. 6 is a graph showing the dependence of the mixing time on the flow speed and the pipe diameter in a mixing pipe.
[0030] FIG. 7 is a graph showing the dependence of the pressure loss on the flow speed and the pipe diameter in a mixing pipe.
[0031] FIG. 8 is a graph showing the dependence of the numbering-up number N(−) on the flow speed and the pipe diameter in a mixing pipe.
[0032] FIG. 9 is an oblique perspective view of a reaction apparatus utilizing swirl flow in the present invention.
[0033] FIG. 10 is a front view and a plan view of a reaction apparatus utilizing swirl flow in the present invention.
[0034] FIG. 11 is an oblique perspective view of a reaction apparatus utilizing swirl flow in the present invention.
[0035] FIG. 12 a front view and a plan view of a reaction apparatus utilizing swirl flow in the present invention.
[0036] FIG. 13 is a Z-Z′ cross sectional view of the mixing flow path in FIG. 12 .
[0037] FIG. 14 is a cross sectional view of a reaction apparatus utilizing swirl flow in the present invention.
[0038] FIG. 15 is an oblique perspective view of a reaction apparatus utilizing swirl flow in the present invention.
[0039] FIG. 16 is a front view of a reaction apparatus using a static mixer in the present invention.
[0040] FIG. 17 is a plan view and a front view of a reaction apparatus using a perforated plate in the present invention.
DESCRIPTION OF SYMBOLS
[0000]
100 : Water header
110 : Supercritical water high pressure pump
120 : Supercritical water pre-heater
200 : Raw material header
210 : Raw material high pressure pump
220 : Raw material pre-heater
300 , 300 a , 300 b : Reaction apparatus
310 X: First inlet flow path
310 Y: Second inlet flow path
320 : Mixing flow path
325 : Structure
326 : Static mixer
327 : Perforated plate
330 : Mixing flow path outlet
400 : Cooling water header
410 : Cooling water high pressure pump
420 a , 420 b : Junction of reaction solution and cooling water
500 a , 500 b : Backwashing fluid header
510 a , 510 b : Drain
520 a , 520 b : Filter
521 a , 521 b : Reaction solution inlet valve of filter
522 a , 522 b : Reaction solution outlet valve of filter
523 a , 523 b : Backwashing fluid inlet valve of filter
524 a , 524 b : Drain valve of filter
620 : Cooler
630 : Orifice
640 : Pressure control valve
X: Raw material line
Y: Supercritical water line
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
[0070] Hereinafter, with reference to the accompanying drawings, description is made on the operation flow in which glycerin is selected as a raw material and supercritical water is selected as water, a reaction is started by mixing these, by-products are separated and removed, and then the reaction solution is collected.
[0071] FIG. 2 is a view illustrating an embodiment of an apparatus for synthesizing acrolein, used in the present invention. First, water is delivered at 35 MPa with a supercritical water high pressure pump ( 110 ) and is increased in temperature to 500° C. with a supercritical water pre-heater ( 120 ). A raw material composed of glycerin and diluted sulfuric acid is delivered at 35 MPa with a raw material high pressure pump ( 210 ) and is increased in temperature to 250° C. with a raw material pre-heater ( 220 ). The water and the raw material are mixed with each other with reaction apparatuses ( 300 a , 300 b ) utilizing swirl flow, and thus instantly the synthesis reaction of acrolein is started at 400° C. and 35 MPa.
[0072] FIG. 3 shows an oblique perspective view of a reaction apparatus utilizing swirl flow in the present invention, and FIG. 4 shows a front view and a plan view of the reaction apparatus shown in FIG. 3 . The end of a cylindrical mixing flow path ( 320 ) is hermetically sealed, and first inlet flow paths ( 310 X) for introducing a fluid containing glycerin into the mixing flow path ( 320 ) and second inlet flow paths ( 310 Y) for introducing a fluid containing supercritical water into the mixing flow path ( 320 ) are connected to the hermetically sealed end. The first inlet flow paths ( 310 X) and the second inlet flow paths ( 310 Y) are each connected to the mixing flow path ( 320 ) in a condition of being offset by δ in relation to the central axis of the mixing flow path ( 320 ). With this structure, a swirl flow can be generated in the mixing flow path ( 320 ) and thus the miscibility can be improved.
[0073] Additionally, the first inlet flow paths ( 310 X) and the second inlet flow paths ( 310 Y) are connected in such a way that the total number of the inlet flow paths is eight, and the first and second inlet flow paths are alternately arranged so as to encircle the central axis of the mixing flow path ( 320 ) with a constant angular interval of 45°. A plurality of the first inlet flow paths ( 310 X) and a plurality of the second inlet flow paths ( 310 Y) are connected to the mixing flow path ( 320 ), hence a multiple layer flow can be formed in the mixing flow path ( 320 ), the diffusion distance is reduced as compared to the conventional two layer flow, and the miscibility can be improved.
[0074] In each of FIGS. 3 and 4 , the first inlet flow paths ( 310 X) and the second inlet flow paths ( 310 Y) are connected at right angle to the central axis of the mixing flow path ( 320 ); however, the connection angle is not limited to this angle. By setting the connection angle at 90° or less, the flow direction in the mixing flow path ( 320 ) and the flow directions of the first and second inlet flow paths ( 310 X, 310 Y) come closer together, and hence the pressure loss can be reduced and the amount of production can be increased.
[0075] In FIG. 3 and the like, the cross sections of the first and second inlet flow paths ( 310 X, 310 Y) are depicted so as to be rectangles, but the first and second inlet flow paths ( 310 X, 310 Y) may have other shapes such as cylinders. The mixing flow path ( 320 ) is also assumed to have a cylindrical shape, and the cylindrical shape as referred to herein includes the shapes each having a polygonal cross section to be approximated as a circle. By setting the width W of each of the first and second inlet flow paths ( 310 X, 310 Y) at one fourth the diameter φ of the mixing flow path ( 320 ), the highest miscibility is obtained.
[0076] Additionally, for the purpose of enhancing the miscibility in the mixing flow path ( 320 ), the flow rate Q X of the raw material high pressure pump ( 210 ) and the flow rate Q Y of the supercritical water high pressure pump ( 110 ) are preferably equal to each other. However, as shown in FIG. 5 , when these two flow rates are different from each other, the miscibility can be improved by making the dimension of the first inlet flow paths ( 310 X) and the dimension of the second inlet flow paths ( 310 Y) different from each other in such a way that the flow speed in the first inlet flow paths ( 310 X) and the flow speed in the second inlet flow paths ( 310 Y) are equal to each other. In other words, the flow rate Q X and the cross sectional area S X expressed by W×H X of the first inlet flow path ( 310 X) and the flow rate Q Y and the cross sectional area S Y expressed by W×H Y of the second inlet flow path ( 310 Y) are preferably set to satisfy the relation Q X /S X =Q Y /S Y .
[0077] When the flow speed is increased by making thin the inner diameter of the mixing flow path ( 320 ), the miscibility is improved to decrease the mixing time, but on the other hand, the pressure loss is increased; therefore, there are optimal values for the inner diameter of the pipe involved and the flow speed. FIGS. 6 , 7 and 8 show the effects of the inner diameter φ of the mixing pipe and the flow speed u on the mixing time and the pressure loss in the mixing pipe and on the number N of the numbering up of the mixing pipe, in a case where the amount of production of acrolein is about 100,000 t/y. In the reaction of the present invention, from the viewpoints of the reaction yield improvement and the reduction of the amounts of the generated by-products, the mixing time is required to be set at 0.2 second or less. Additionally, in general, from the viewpoints of the reduction of the solution delivery energy and the reliability improvement of the instrumentation and control of the plant, the pressure loss and the number of the numbering up are required to be set at 1 MPa or less and 30 or less, respectively. In consideration of what has been described above, preferably the inner diameter of the mixing pipe is 10 to 50 mm, the flow speed is 2 to 20 m/s and the number of the numbering up is 10 to 50. Additionally, in a more preferable case, the inner diameter of the mixing pipe is about 20 mm, the flow speed is about 10 m/s and the number of the numbering up is about 30.
[0078] The material of the reaction apparatus of the present embodiment is preferably Ni-base alloys, having corrosion resistance equal to or higher than the corrosion resistance of SUS 316L, such as Inconel 625 and Hastelloy C-276.
[0079] By using the reaction apparatus shown in FIG. 3 , even in a commercial plant having an amount of production of 100,000 t/y, the fluid containing supercritical water and the fluid containing glycerin are made to form multiple layers and the diffusion distance can be reduced, and by delivering the solutions with the aid of turbulent flow to increase the turbulent flow diffusion coefficient, the swirl flow can be generated in the mixing flow path; therefore, as a result of the combination of these facts, the miscibility can be drastically improved. By improving the miscibility, the reaction yield is improved and the amounts of generated tar and the generated by-products can be reduced. Accordingly, the occlusion of the pipes and valves due to the adhesion of the by-products can be prevented. Further, the abrasion of the valving elements and the valve seats are suppressed, and hence the precise pressure control can be performed. Therefore, highly efficient operation of the commercial plant is made possible.
[0080] Next, after the optimal reaction time has elapsed in the reaction apparatus ( 300 ), cooling water is delivered to the junction ( 420 a , 420 b ) for the purpose of terminating the reaction by using the cooling water high pressure pump ( 410 ) shown in FIG. 2 , and the reaction is terminated by direct mixing of the cooling water. Because the optimal reaction time is a few seconds when the glycerin concentration is set at 15%, the reaction solution is required to be rapidly cooled to the reaction termination temperature in a time of about one-tenth the optimal reaction time. Because the inner diameter of the reaction pipe is as large as a few centimeters, the adoption of the direct mixing of cooling water improves the controllability of the reaction time as compared to the indirect cooling with a double pipe cooler. Additionally, by using the above-described reaction apparatus utilizing swirl flow in order to mix the reaction solution and the cooling water with each other, the controllability of the reaction time is further improved and the reaction yield can be enhanced.
[0081] After the termination of the reaction, the reaction solution is subjected to the separation of tar and carbon particles with the filters ( 520 a , 520 b ) in the subsequent stage in such a way that only the carbon particles are captured with the filters and the tar is allowed to pass while keeping the high viscosity thereof. Accordingly, the occlusion of the pipes due to the mutual aggregation of tar and carbon particles is prevented.
[0082] By preparing two or more systems of filters for separating and removing carbon particles, the operations of eliminating carbon particle cakes from these filter systems with the aid of backwashing can be performed alternately. Accordingly, not the whole plant is required to be halted, the continuous operability is improved, the heat loss due to the start-up of the plant can be reduced, and the operation cost can be reduced.
[0083] The reaction solution from which carbon particles have been removed is cooled in a second cooler ( 620 ), then decreased in pressure down to the atmospheric pressure with an orifice ( 630 ) and a pressure regulation valve ( 640 ) and is delivered to a distillation apparatus for acrolein in the subsequent stage.
Second Embodiment
[0084] FIG. 9 shows an oblique perspective view of an embodiment of the reaction apparatus utilizing swirl flow in the present invention, and FIG. 10 shows a front view and a plan view of the reaction apparatus. In the case of a small reaction apparatus having a mixing flow path ( 320 ) of 1 cm or less in inner diameter, eight of the first and second inlet flow paths ( 310 X, 310 Y) cannot be connected. In the reaction apparatus of the present embodiment, the first inlet flow paths ( 310 X) and the second inlet flow paths ( 310 Y) are connected in such a way that the total number of the inlet flow paths is four, and the first and second inlet flow paths are alternately arranged so as to encircle the central axis of the mixing flow path ( 320 ) with a constant angular interval of 90°. Although not shown, the total number of the first inlet flow paths ( 310 X) and the second inlet flow paths ( 310 Y) may also be six. The miscibility can be improved as compared to conventional T-shaped pipes and conventional reaction apparatuses having two inlet flow paths and utilizing swirl flow.
Third Embodiment
[0085] FIG. 11 shows an oblique perspective view of an embodiment of the reaction apparatus utilizing swirl flow in the present invention, and FIG. 12 shows a front view and a plan view of the reaction apparatus. In the reaction apparatus in the present embodiment, the end of the cylindrical mixing flow path ( 320 ) is hermetically sealed, and the first inlet flow paths ( 310 X) for introducing a fluid containing glycerin into the mixing flow path ( 320 ) and the second inlet flow paths ( 310 Y) for introducing a fluid containing supercritical water into the mixing flow path ( 320 ) are connected to the hermetically sealed end. The first inlet flow paths ( 310 X) and the second inlet flow paths ( 310 Y) are each connected to the mixing flow path ( 320 ) in a condition of being offset by δ in relation to the central axis of the mixing flow path ( 320 ). Additionally, the first inlet flow path ( 310 X) and the second inlet flow path ( 310 Y) are each provided in a plurality of numbers so as to be separated away from each other along the flow direction of the mixing flow path ( 320 ). Because the first inlet flow path and the second inlet flow path are each provided in a plurality of numbers so as to be separated away from each other along the flow direction, the swirl flow layer of the subsequent stage is generated outside the swirl flow layer of the preceding stage. Therefore, as shown in the Z-Z′ cross section ( FIG. 13 ) of the mixing flow path ( 320 ) shown in FIG. 12 , a multiple layer swirl flow can be generated. Accordingly, the interlayer distances are reduced, and hence the miscibility can be improved. When the flow rate of the raw material high pressure pump and the flow rate of the supercritical water high pressure pump are different from each other, the miscibility can be enhanced, as described above, by determining the cross sectional area (W×H) of the first inlet flow path and the cross sectional area (W×H) of the second inlet flow path in such a way that the flow speed of the first inlet flow path and the flow speed of the second inlet flow path are equal to each other. In the present embodiment, the total number of the first and second inlet flow paths at each stage is set at 2; however, by increasing this total number to 4, 6 or 8, the miscibility can be further improved.
Fourth Embodiment
[0086] FIG. 14 shows an embodiment of the reaction apparatus utilizing swirl flow in the present invention. In the reaction apparatus utilizing swirl flow, a conical portion low in miscibility is generated on the central axis of the mixing flow path ( 320 ). The miscibility can be improved by disposing a structure ( 325 ) in the low miscibility portion. Additionally, by the presence of a structure in the central portion of FIG. 13 , the interlayer distances are further reduced, and hence the miscibility can be improved. The structure disposed on the central axis of the mixing flow path is preferably formed so as to be made thinner (so as for the cross sectional area of the structure to be made smaller) as going toward the downstream of the mixing flow path. The use of the structure in the reaction apparatuses utilizing swirl flow of the other embodiments can also improve the miscibility.
Fifth Embodiment
[0087] FIG. 15 shows another embodiment of the reaction apparatus utilizing swirl flow in the present invention. For the purpose of improving the amount of production of the reaction apparatus, the throughput as well as the reaction yield is required to be increased. In the reaction apparatus in the present embodiment, the first and second inlet flow paths ( 310 X, 310 Y) are connected so as to make an angle of less than 90° relative to the central axis of the mixing flow path ( 320 ), and hence the pressure loss can be reduced and the amount of production can be increased.
Sixth Embodiment
[0088] FIG. 16 shows an embodiment of the reaction apparatus using a static mixer in the present invention. In the reaction apparatus, the first inlet flow path ( 310 X) for making a fluid containing glycerin flow into the mixing flow path ( 320 ) and the second inlet flow path ( 310 Y) for making a fluid containing supercritical water flow into the mixing flow path ( 320 ) are connected to the end of the cylindrical mixing flow path ( 320 ). Additionally, in the present embodiment, the mixing flow path ( 320 ) is equipped with a static mixer ( 326 ). The raw material and the supercritical water made to flow into the mixing flow path ( 320 ) are agitated with the static mixer ( 326 ) and the interlayer distances are further reduced and hence the miscibility is improved.
Seventh Embodiment
[0089] FIG. 17 shows an embodiment of the reaction apparatus using a perforated plate in the present invention. In the reaction apparatus, the first inlet flow path ( 310 X) for making a fluid containing glycerin flow into the mixing flow path ( 320 ) and the second inlet flow path ( 310 Y) for making a fluid containing supercritical water flow into the mixing flow path ( 320 ) are connected to the end of the cylindrical mixing flow path ( 320 ) in the same manner as in the sixth embodiment. Additionally, in the present embodiment, the mixing flow path ( 320 ) is equipped with a perforated plate ( 327 ). The raw material and the supercritical water made to flow into the mixing flow path ( 320 ) are made to pass through the perforated plate ( 327 ) to be enhanced in miscibility. The perforated plate ( 327 ) may be provided in a plurality of numbers along the mixing flow path ( 320 ). In such a case, the perforation rates of the perforated plates may be set at different values from one perforated plate to another. | An object of the present invention is to provide a method for commercially manufacturing acrolein in a large flow rate by making supercritical water and an acid interact with glycerin, wherein by efficiently mixing high-concentration glycerin and supercritical water with each other, the method is made capable of making the synthesis stably proceed with a high yield while the occlusion and abrasion of the pipes and devices due to the generation of by-products are being suppressed. The method for synthesizing acrolein of the present invention is a method for synthesizing acrolein by making supercritical water and an acid interact with glycerin, the method using a reaction apparatus including: a cylindrical mixing flow path for mixing a fluid including glycerin and a fluid including supercritical water with each other; a first inlet flow path, disposed offset from the central axis of the mixing flow path, for making the fluid including glycerin flow into the mixing flow path; and a second inlet flow path, disposed offset from the central axis of the mixing flow path, for making the fluid including supercritical water flow into the mixing flow path, wherein the first inlet flow path and the second inlet flow path are each provided in a plurality of numbers in such a way that the first inlet flow paths and the second inlet flow paths are alternately arranged so as to encircle the central axis of the mixing flow path. | 1 |
DESCRIPTION
The invention relates to a drilling tool having a drill head axially supported by an interchangeable conveying helix.
Drilling tools with interchangeable conveying helices are primarily used for making apertures while using electrically or pneumatically driven hammer drills. In these tools, the carbide-tipped drilling head is designed as a cross drilling head or solid drilling head. Tools of this type are shown, for example, in German Offenlegungsschrift 2,639,310, German Offenlegungsschrift 3,044,757 or German Offenlegungsschrift DE 2,543,578A1.
European patent 0,264,657A1, a counterpart to U.S. Pat. No. 4,852,670, and to Federal Republic of Germany Offenlegungsschrift 3,635,538 has disclosed a drilling tool having an interchangeable conveying helix in which a coil spring is provided between conveying helix and axial supporting ring, which coil spring permits certain axial play of the conveying helix relative to the drill shank. The conveying helix can move away from the drilling head against the force of the spring and can also fully rotate freely relative to the drilling head or the drill shank in particular in the event of jamming or tilting of the helix in the drilled hole. Destruction of the plastic helix can thereby be avoided.
The contact force, produced by the supporting spring, between the conveying helix and the drilling head depends on the loading capacity of the plastic helix. If the contact force is set very high, the conveying helix is axially displaced and thus the positive-locking connection between conveying helix and drilling head is separated only during very high loading as a result of tilting or jamming. But this can lead to premature destruction of the conveying helix. Conversely, the contact force must be at least so large that there is always good positive locking between conveying helix and drilling head to bridge the play provided for the conveying helix.
As a result of the drilling-dust grooves which are contained in the drilling head and in which the conveying helix is generally anchored in a positive-locking manner, the effective contact-pressure area or connecting area of the positive-locking connection between conveying helix and drilling head is kept relatively small. Here, therefore, high surface pressures and thus increased stress on the conveying helix occur. Furthermore, in the known arrangement, during sudden stressing of the conveying helix caused by jamming or tilting, the positive-locking connection is subjected to exceptionally high impact loading, since the axial displacement for bridging the play provided cannot make a sudden adjustment. This can also result in premature destruction or fracture of the conveying helix.
The object of the invention is to improve a drilling tool of the type described above to the effect that the conveying helix is exposed to less forces in operation so that the wear on the conveying helix and thus the risk of fracture is reduced.
Starting from a drilling tool of the type designated at the beginning this object is achieved by the provision of a spring-loaded conveying helix pressing against, supporting, and rotating a drilling head through frictional forces. Advantageous and convenient further development of the invention are as specified below.
Compared with known devices, the drilling tool according to the invention has the advantage that the life in particular of a plastic conveying helix can be considerably increased in certain applications. According to the invention, no provision is made for an otherwise customary positive-locking connection between conveying helix and drilling head, but rather provision is made for a frictional-resistance connection. In this respect, the invention is based on the knowledge that it has proved to be safe in practice if the conveying helix, even during any slight jamming, rotates slightly relative to the drilling head or the mounting shank. This rotated position cannot generally affect unimpeded drilling-dust removal so that a positive-locking connection between conveying helix and drilling head is not imperative. On the contrary, when helices made in particular of plastic are used, the crucial factor is that sudden loading of the helix is to be avoided as far as possible during jamming or tilting, i.e. the helix should immediately disengage without a time lag during stressing of this type. However, according to the invention, this is only possible with a conveying helix which fully slips immediately and does not first have to be axially displaced. The connection between the conveying helix and the drilling head has therefore been made as a frictional-resistance connection, in which arrangement no significant axial displacement occurs between the conveying helix and the drilling head. On the contrary, the supporting spring now has the other task of achieving an adequate contact force of the conveying helix relative to the drilling head so that the conveying helix does not fully slip in normal operation. Tests have shown that this type of connection is adequate in practice, this advantage being thus associated with extremely careful treatment of the conveying helix.
The bearing surface between conveying helix and drilling head can be designed so as to be flat, conical or even arched. The latter has the advantage that a larger bearing surface and thus better frictional resistance is ensured.
To improve the frictional resistance, it can be convenient and advantageous for the contacting bearing surfaces between conveying helix and drilling head to be roughened. The roughening can, for example, be designed as a type of fluting. Furthermore, better frictional resistance can be achieved by the additional application of a friction lining or by an additional friction disk.
Furthermore, it is advantageous that the spring force of the supporting spring and thus of the frictional resistance is made to be adjustable. This can be achieved, for example, by the supporting ring being adjustable in its axial position. Supporting springs of different hardness can also be used.
Further features and advantages essential to the invention are obtained from the following exemplary embodiments described in greater detail with reference to the drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a side view of the drilling tool according to the invention; and
FIG. 2a shows a sectional representation of the connection between conveying helix and drilling head in a first embodiment;
FIG. 2b shows a partially sectional representation of second embodiment of the contact surface of the invention;
FIG. 3a shows a third embodiment of the invention, similar to FIG. 2a;
FIG. 3b shows a fourth embodiment of the invention similar to FIG. 3a; and
FIG. 4 shows a still further partially sectional embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The drilling tool 1 shown in FIG. 1 consists of a drill shank 2 and a drilling head 3 which is designed, for example, as a cross drill bit as disclosed, for example, by German Offenlegungsschrift 3,426,977. The slip-on and interchangeable conveying helix 4 is designed as a plastic slip-on helix profiled from the solid, i.e. the conveying helix has its own drill helix profile. Solid plastic helices of this type are known, for example, from DE 3,614,010.4A1.
Instead of the solid plastic helix 4, a wound conveying helix can also be used provided it addresses the same problem as is addressed by the invention.
The conveying helix 4 is defined at the bottom in the axial direction by the supporting spring 5, the longitudinally supporting spring being supported on a supporting ring 6. The supporting ring 6 consists of a radially expandable, longitudinally slotted supporting sleeve 7 which can be snapped into a turn groove in the drill shank 2, the lower part of the supporting spring 5, to block the radial expansion of the supporting sleeve, surrounding an upper supporting sleeve area 7'.
The supporting spring 5 has the same winding direction as the conveying helix 4 so that additional conveying action can be obtained for drilling dust.
As apparent from FIG. 2a in sectional representation, the conveying helix 4, in its upper area 8, is axially supported by means of a frictional-resistance connection at the contact surface 9. Here, in FIG. 2a, as an alternative embodiment, the drilling tool is shown as having a conical or truncated-cone-shaped contact surface 9'. FIG. 2b shows the embodiment which has a flat contact surface 9". The conical design of the contact surface 9' has the advantage of a greater connecting area and thus an increased frictional-resistance action. Contact surfaces 9'" and 9"" surface can also be of arched design as shown in the third and fourth embodiments of FIGS. 3a and 3b. The mutual contact surfaces 9 between conveying helix 4 and drilling head 3 are conveniently roughened, as best seen in FIG. 2a. For this purpose, a type of fluting 10 is schematically indicated in the left hand half of FIG. 2a. Another type of roughening can also be used to increase the friction moment, e.g. in the form of an adhesive or a friction lining adhesively bonded or sprayed on. Also, as seen in FIG. 4, showing a still further embodiment, an additionally incorporated friction disk 12 can be used.
The supporting spring 5, with a certain contact force or spring 11, presses the conveying helix 4 toward the drilling head 3. During normal loading of the drilling tool, this results in a frictional-resistance connection between conveying helix 4 and drilling head 3, thus ensuring that the conveying helix 4 is reliably driven along in a rotating manner on the drill shank 2. The contact spring force 11 can be changed by varying the spring hardness of the supporting spring 5. This would be ensured, for example, by axial displacability or adjustability of the supporting ring 6 as indicated by the arrow in FIG. 2b or by springs 5 of different strength.
The jamming action is described in European Patent 0,264,657 which is a counterpart to U.S. Pat. No. 4,852,670, and to Federal Republic of Germany Offenlegungsschrift 3,635,538. This occurs in particular when making apertures in fissured rock.
As soon as the conveying helix 4 in the drilling tool according to the invention jams, the frictional-resistance connection between conveying helix 4 and drilling head 3 can be released by slight axial displacement so that damage to the conveying helix is impossible. As soon as the jamming between conveying helix and drilled hole has been released, the supporting spring 5, via the contact spring force 11, again pushes the conveying helix 4 to a sufficient extent against the drilling head 3 so that a frictional-resistance connection is created at the various contact surfaces 9', 9", 9'", and 9"". | A drilling tool is proposed which is preferably suitable for making apertures in concrete work or masonry is fissured rock. To avoid damaging an interchangeable conveying helix (4), the connection between the conveying helix (4) and drilling head (3) is made as a frictional-resistance connection (FIG. 2). | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to improvements in developing devices, and particularly relates to improvements in developing devices in which developer is smoothly conveyed, uneven image density does not occur, and further developer does not scatter and leak from the container of the developing device.
Regarding different forms of image recording apparatus, the following are widely known.
(a) An electrophotographic image recording apparatus, which is called an electrophotographic copier.
(b) An image recording apparatus such as a laser beam printer, which is characterized in that: a surface is divided into a plurality of small areas, which will be called dots hereinafter; digital information which indicates coloring or non-coloring, is given to each dot; and an image is formed on the above-described surface according to the digital information.
In these kinds of image recording apparatus, a toner supply means which supplies a coloring agent (which will be called toner hereinafter), is needed on the assumption that an image signal medium, for example an electrophotographic photoreceptor drum on which a latent image is formed, wherein a coloring command is given to the dot on the image signal medium on which coloring is to be conducted and a non-coloring command is given to the dot on which coloring is not to be conducted.
Regarding the toner supply means, toner must be uniformly and detachably attracted to the surface of the toner supply means.
The present invention relates to improvements in this kind of toner supply means, which will be called a developing means in this specification hereinafter.
Referring to FIG. 2a, a conventional developing unit will be explained as follows.
In FIG. 2a, the numeral (1) is a developer stirring means which is composed of two screws (11) and (12). Toner is supplied to the developer stirring means (1) from a toner casing means (not shown in the drawing) which is located above the developer stirring means (1). The supplied toner is conveyed by the screw (11) to the viewer's side in the drawing. At this moment, in this example, a coloring material carrying means (which will be called a carrier hereinafter), which is composed of particles, the diameter of which is approximately 50 μm, made from magnetic material, is supplied from the side of the screw (12). As a result, the toner and carrier are uniformly stirred and mixed so that they are transformed into a developer.
This developer is uniformly contacted with the surface of the developer conveying means (7) (which is a triangular body of rotation in this example) with pressure by the action of the screw (12), wherein the developer conveying means (7) functions in the subsequent process.
The numeral (3) is a developer holding means which is composed of the sleeve (31), a cylindrical body of rotation, and a magnetic means (32) which is fixed to the inside of the sleeve (31). The surface of the sleeve (31) attracts developer. When the sleeve (31) is rotated and contacted with an image signal medium (for example, an electrostatic photoreceptor drum on which a latent image is formed), which is not illustrated in the drawing, the toner contained in the developer attracted onto the surface of the sleeve (31) is supplied from the sleeve (31) to the latent image formed on the above-described image signal medium so that the above-described latent image can be developed. In the way described above, only carrier is left on the region of the sleeve (31) surface from which the toner was supplied to the latent image, so that the toner concentration on the sleeve (31) becomes uneven.
The function of the above-described magnetic means is as follows: the magnetic means attracts the developer onto the above-described sleeve (31) while development is conducted; and the means removes the residual toner from the above-described sleeve (31) after development has been completed.
The numeral (4) is a developer layer thickness regulating means which controls the developer so that a desirable thickness of developer layer can be formed on the above-described sleeve (31).
The numeral (7) is a developer conveying means which conveys the developer pushed out by the screw (12) to the developer holding means (3), and which conveys the developer (in which the amount of toner is small and the amount of carrier is relatively large) that has been removed from the developer holding means (3) to the region of the developer stirring means (1).
The numeral (9) is a developing unit body in which the above-described units are installed.
The composition of a conventional developing unit has been explained above. On the other hand, the following idea is proposed with regard to the means which conveys the developer removed from the sleeve (31) to the region of the stirring screw (12): for example, a magnetic conveying means composed of a cylindrical rotative body on which a magnetic pole is formed, is used as the developer conveying means; and the removed developer is forcibly conveyed to the region of the developer stirring means (1) by attracting the above-described removed developer onto the rotative body of the magnetic conveying means.
As explained above, in the case of a conventional developing unit, after the toner has been supplied onto the latent image formed on an image signal medium, developer in which relatively small amount of toner is contained compared with the amount of carrier, is left on the region of the sleeve (31), so that the concentration of toner left on the sleeve (31) becomes uneven. Consequently, it is necessary to remove all the toner from the sleeve (31), otherwise the image density will undesirably become uneven when an image is formed next time. However, there is a problem that it is difficult to remove all the toner from the surface of the sleeve (31), so that some of the toner will be left on the surface even after toner removal has been conducted.
Such an idea is essentially disadvantageous in that: in order to efficiently convey the developer removed from the surface of the sleeve (31) to the region of the developer stirring means, a magnetic conveying means which is composed of a cylindrical rotative body, on which surface a magnetic pole is formed, is used so that the above-described developer can be attracted onto its surface and the attracted developer is forcibly conveyed to the region of the developer stirring means (1). The reason why this idea is disadvantageous is that the developer attracted to the cylindrical rotative body by magnetic force can not be completely separated from the body when it is conveyed to the position close to the conveyance screw (12). In other words, a portion of the developer is left on the surface of the above-described rotative body and returned to the region where the toner was initially placed.
Another idea has been put forward: after development has been completed, the residual developer, in which the amount of toner is relatively small compared with the amount of carrier, is forcibly removed by a mechanical method. The inventor has already invented a developing device according to the idea described above, and made an application.
However, there is a problem in the developing device in which the residual developer is forcibly removed from the developer holding means by a mechanical method, which is that the removed developer is scattered and leaks outside the container of the developing device through an opening, and as a result, the image formed on an image signal medium is stained.
Refer to FIG. 2b and FIG. 2c.
FIG. 2b is a sectional side view of a developing device relating to another conventional technology, and FIG. 2c is a front view of the developing device, which is taken from its opening.
In FIG. 2c, the circumferential surface of the sleeve (31) corresponding to the axial length of the magnetic means (32), is made coarse, by sandblasting for example. This rugged region is actually a developer holding region, which will be called a sandblasted width in this specification hereinafter.
The numeral (91) in FIG. 2b is an opening provided to one end of the casing means (9). A portion of the above-described developer holding means (3) is protruded from the opening (91) and opposed to an image signal medium not illustrated in the drawing.
The numeral (10) is a developer spill prevention means made of a velvet-like material. One surface of the developer spill prevention means composed of this material is adhered to the inside of the casing means (9) so that the developer spill prevention means (10) can be opposed to the smooth circumferential surfaces of the above-described sleeve (31), wherein the surface of the middle portion of the sleeve (31) is rugged and the surfaces of the edge portions are smooth. The other surfaces of the developer spill prevention means (10) made of velvet-like material are pressed against the smooth circumferential surfaces provided on both sides of the sleeve (31). The function of the developer spill prevention means (10) is as follows: the leakage of developer from the positions around the smooth surfaces on both sides of the sleeve (31) to the outside of the container of the developing device, can be prevented by the developer spill prevention means (10).
However, the above-described developer spill prevention means is pressed against the circumferential surface of the sleeve which composes the developer holding means, so that high frictional resistance is caused when the developer holding means is rotated. Consequently, high torque is necessary to rotate the developer holding means. As a result, the rotation speed of the developer holding means tends to be varied and the density of recorded images becomes uneven. Accordingly, it has been desired to develop a developing device provided with a means which can prevent the leakage of developer from the casing means without using the conventional developer spill prevention means.
Refer to FIG. 2a.
Further, another conventional developing device will be briefly explained as follows.
The rotating members (1), (7) and (3) are generally driven by a single drive means (not illustrated in the drawing). In this case, when the revolution speeds of the rotating members (1), (7) and (3) are varied, the amount of toner supplied to an image signal medium in a unit time is varied, so that uneven density distribution of an image is caused. In order to prevent the unevenness of density, it is common to maintain a constant revolution speed.
In order that uneven image density does not occur and smooth circulation of developer is conducted, there is a developing device comprising: a developer removing means composed of a scraper which removes the developer from the developer holding means (3); and a magnetic conveying means (for example, the magnetic conveying means is composed of a cylindrical rotative body, on the surface of which a magnetic pole is formed) which smoothly conveys the used developer removed from the developer holding means (3) to the region of the developer stirring means (1).
When the developing apparatus according to the above-described idea was realized, it could be confirmed that: the occurrence of uneven image density was effectively prevented; and further the used developer removed from the developer holding means (3) was smoothly conveyed to the region of the magnetic conveying means. However, the following disadvantages were found in this developing unit: the used developer undesirably stays in the region of the magnetic conveying means; and a drive means to drive the magnetic conveying means and the developer holding means (3) could not be smoothly operated due to the residual developer, so that the uneven density distribution was caused in obtained images.
Refer to FIG. 2a.
Further, another conventional developing device will be briefly described as follows.
In the developing device illustrated in FIG. 2a, gaps of about 1 mm are formed between the upper edge (911) of the casing means (9) and the developer holding means (3), and between the lower edge (912) and the developer holding means (3).
There is a disadvantage in the case of the developing device described above, as follows: when the used developer is mechanically removed from the developer holding means (3) by the developer removing means, the removed developer is scattered and leaks outside the container of the developing device, so that the image signal medium and the recording paper become stained.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide a developing device which is characterized in that: uneven image density, by which the density of a formed image becomes undesirably uneven, can be prevented; and the developer can be smoothly circulated in the device.
The second object of the present invention is to provide a developing device which is characterized in that: uneven image density can be prevented; and the powdery developer can not be scattered from the container of the developing device.
The third object of the present invention is to provide a developing device which is characterized in that: uneven image density can be prevented; the developer is smoothly circulated in the device; and each drive means can be rotated without any obstruction, so that the occurrence of uneven density distribution of an image can be prevented.
Refer to FIGS. 1a, 1b and 1c.
The developing device of the present invention comprises: a developer stirring means (1) which stirs toner and carrier in order to prepare the composition of developer; a developer supply means (2) which supplies the developer prepared by the developer stirring means (1); a developer holding means (3) which attracts the developer supplied by the developer supply means (2) onto its surface, conveys the developer to the development region; a height regulating means (4) which regulates the layer thickness of the developer attracted onto the surface of the developer holding means (3); a developer removing means (5) which removes the residual developer from the surface of the developer holding means (3) after development; a magnetic conveying means (6) which conveys the developer removed from the developer holding means (3) to the region of the developer stirring means (1); and a mechanical conveying means (8) which is placed in the region between the magnetic conveying means (6) and the developer stirring means (1), which removes the developer attracted onto the surface of the magnetic conveying means (6), and moves the removed developer toward the region between the magnetic conveying means (6) and the developer stirring means (1).
In the composition described above, the mechanical conveying means (8), which is made from a non-magnetic body (83), may be composed as follows: one end (81) of the mechanical conveying means (8) is placed in the position close to the surface of the magnetic conveying means (6) or contacted with the above-described surface of the magnetic conveying means (6) in the region between the magnetic conveying means (6) and the developer stirring means (1); the other end (82) of the mechanical conveying means (8) is connected with the above-described developer removing means (5); otherwise, in order to form a magnetic shield so that the deterioration of stirring effect of the developer stirring means (1) can be prevented, wherein the deterioration of stirring effect is caused by the influence of the magnetic field of the magnetic conveying means (6), the above-described mechanical conveying means (8) is composed of laminated layers of the non-magnetic body (83) and the magnetic body (84); and only the above-described non-magnetic body (83) of one end (81) of the mechanical conveying means (8) is placed in the position close to the surface of the above-described magnetic conveying means (6) or contacted with the above-described surface of the magnetic conveying means in the region between the magnetic conveying means (6) and the developer stirring means (1), and the other end (82) of the mechanical conveying means (8) is connected with the above-described developer removing means (5).
The developer removing means (5) is preferably provided with a resilient and sharp edge portion so that it can scrape off the attracted developer for a long period of time, and it is preferable that the developer removing means (5) is made from a hard and resilient material with high formability. In order to meet the requirements described above, urethane rubber, phosphor bronze and polyethylene terephthalate are preferably used.
The magnetic conveying means (6) may be a rotative body having a magnet or it may be a magnet which is moved in the direction of the movement of carrier.
Stainless steel, aluminum and rubber are preferably used as the non-magnetic material of the above-described mechanical conveying means (8). It is desirable that the mechanical conveying means (8) is provided with an edge portion which is sufficiently resilient and sharp in order to effectively scrape off the developer for a long period of time.
The cause of uneven image density, which can be solved by the present invention, is the uneven toner concentration of developer which is attracted onto the sleeve (31) constituting the developer holding means (3). This unevenness of toner concentration is caused when the used developer, in which a large amount of carrier is contained, is left on the sleeve (31) surface. Accordingly, it is necessary to completely remove the used developer from the sleeve (31). For that reason, the polarity of the magnetic means (32) which is provided inside the sleeve (31), is aligned so that this object can be attained.
The magnetic means (32) composed in such a manner explained above, functions almost satisfactorily. However, according to the results of experiments conducted by the inventors, it has become clear that when the capacity of scraping off is a little increased, satisfactory performance can be achieved.
Specifically, a magnetic means, an electrical means and a mechanical means can be applied in order to increase the capacity of scraping off. In this case, the mechanical means has been selected in order to remove the used developer mechanically because it is the simplest and most effective method. In this case there is a problem as follows: unless the developer which has been removed from the sleeve surface, in which the amount of carrier is relatively large compared with the amount of toner, is effectively conveyed to the subsequent process, it is left and attracted again onto the sleeve (31) surface; and as a result the concentration of toner on the development sleeve (31) becomes uneven.
In order to solve the problem described above, it has been determined that fine ferrite particles should be used as the carrier in the used developer so that the used developer can be effectively conveyed to the subsequent process. Specifically, the magnetic conveying means (6) is provided and the used developer is magnetically attracted to the means in order to positively convey the used developer to the subsequent process.
Next, the mechanical conveying means (8) is placed in the region between the magnetic conveying means (6) and the developer stirring means (1) in order to solve another problem, which can be described as follows: an amount of carrier is left on the surface of the magnetic conveying means (6), so that the developer can not be smoothly circulated. The residual developer left on the surface of the magnetic conveying means (6) is mechanically removed by the mechanical conveying means (8) in order to circulate the developer smoothly. Specifically, one end (81) of the mechanical conveying means (8) is placed in the position close to the surface of the magnetic conveying means (6) or contacted with the surface in order to simply and effectively scrape off the residual carrier left on the surface. In this case the above-described mechanical conveying means (8) is composed of a non-magnetic body, or a laminated body of a non-magnetic body and a magnetic body. In the former case, one end (81) of the mechanical conveying means (8) is made of a non-magnetic body so that the residual developer on the magnetic conveying means (6) can be easily removed. In the latter case, the mechanical conveying means (8) is made of a laminated body so that the carrier removed by one end (81) made of a non-magnetic body, can be positively attracted by the laminated magnetic body and conveyed to the region where the developer stirring means (1) is placed.
The means to accomplish another object of the present invention is composed as follows.
In FIG. 1d, the opening (91) is formed at one end of the casing means (9), which is the main body; a portion of the developer holding means (3) is protruded from the opening (91); and the developer holding means (3) is installed inside the casing means (9) in such a manner that gaps of approximately 1 mm are made between the upper and lower edges (911), (912) of the above-described opening (91) and the developer holding means (3). Further, the following units are installed inside the above-described casing means (9): the height regulating means (4) which is placed in the position close to the developer holding means (9) and regulates the layer thickness of the developer attracted onto the surface of the developer holding means; the developer supply means (2) which supplies the developer to the developer holding means (3); the developer stirring means (1) which is placed in the position close to the developer supply means (2) and stirs the carrier and toner in order to prepare the composition of the developer; and the developer removing means (5), one end of which is contracted with the developer holding means (3) in order to remove the residual developer from the developer holding means (3).
The following units relating to the present invention are added to the developing device described above.
The unit relating to the present invention is the developer leakage prevention means (102) which is placed in the position close to the lower edge (912) of the opening (91) and composed of a magnet, the polarity of which is reverse to that of the magnet in the developer holding means.
The developer leakage prevention means (102) is disposed along the developer holding means (3) in parallel with the rotational axis or longitudinally of the developer holding means.
This magnet may be located in the place between the developer removing means (5) and the lower edge (912) of the opening (91).
As illustrated in FIG. 1e, the magnetic pole of reverse polarity to that used in the developer leakage prevention means (102) is located on the reverse side to the magnetic pole opposed to the developer holding means (3). As illustrated in FIG. 1f, the polarity of the magnet used in the apparatus of the present invention may be composed in such a manner that: the magnetic pole, the polarity of which is reverse to that of the developer holding means (3), is placed between two magnetic poles, the polarity of which is the same as that of the developer holding means (3).
The developing device according to the present invention, is provided with the developer leakage prevention means (102) (which is the main concept of the present invention), which is located in the position close to the lower edge (912) of the opening (91), and which is composed of a magnet placed in the position opposed to the magnet of the developer holding means (3), and the polarity of the magnet is reverse to that of the developer holding means (3). Accordingly, a magnetic field is formed between the magnets of the developer leakage prevention means (102) and the developer holding means (3).
According to the experiments made by the inventors, the following was found: the carrier particles contained in the developer placed in the above-described magnetic field, were magnetized and attracted with each other so that a body of attracted carrier was formed, and the developer holding means (3) and the developer leakage prevention means (102) were bridged by bodies of attracted carrier, which were formed in parallel with each other, so that the shape of the bodies of attracted carrier was like a curtain, which could prevent the powdery developer (toner) from scattering. Consequently, leakage of developer could be prevented.
Another means to accomplish the second object of the present invention is composed as follows.
(a) The main body of this means is the casing means (9) on which the opening (91) is formed;
(b) the developer holding means (3) is installed in the casing means (9) in such a manner that a portion of the developer holding means (3) is protruded from the opening (91), and that gaps are formed between the upper edge (911) of the opening (91) and the developer holding means (3), and between the lower edge (912) and the developer holding means (3);
(c) the height regulating means (4) is installed in the casing means (9), which is placed in the position close to the developer holding means (3) and regulates the layer thickness of developer attracted onto the surface of the developer holding means (3);
(d) the developer supply means (2) is installed in the casing means (9), which supplies the developer to the developer holding means (3);
(e) the developer stirring means (1) is installed in the position close to the developer supply means (2) in the casing means (9);
(f) the developer removing means (5) is installed in the casing means (9), which removes the residual developer from the developer holding means (3);
(g) the magnetic conveying means (6) is installed in the casing means (9), which conveys the developer removed from the developer holding means (3) to the developer stirring means (1);
(h) and the axial length of the magnetic conveying means (6) is set to be longer than the corresponding length of the magnetic means (32) which constitutes the developer holding means (3).
The length of the magnetic means (32) is generally the same as the axial length (which is defined as the sandblasted width in this specification) of the region of the sleeve (31) of which the surface is finely rugged. Accordingly: the axial length of the magnetic conveying means (6) is longer than the above-described sandblasted width. If the length of the magnetic means (32) is not the same as the sandblasted width, the axial length of the magnetic conveying means (6) is preferably longer than any of the length of the magnetic means (32) and the sandblasted width.
In the developing device of the present invention, the residual developer can be mechanically removed from the surface of the developer holding means (3) by the developer removing means (5), so that the used developer (the toner amount of which is small and the carrier amount of which is relatively large) is completely removed and a layer of developer, the toner density of which is uniform, can be continuously formed and the occurrence of uneven image density can be prevented.
Further, in the developing device of the present invention, the magnetic conveying means (6) magnetically attracts the developer removed from the sleeve (31) by the developer removing means (5) and conveys the removed developer to the region of the screw (12) of the developer stirring means (1). Consequently, the developing device of the present invention is excellent in the efficiency of conveying the used developer to the region of the developer stirring means.
The developer spill prevention means (10) of a conventional developing device prevents the used developer from leaking outside from both sides of the sleeve (31) which constitutes the developer holding means (3).
The inventors has then considered that: if the used developer does not leak to the outside from the circumferential surfaces of both sides of the sleeve (31) constituting the developer holding means (3), and is positively attracted and conveyed to the region of the developer stirring process, the above-described developer spill prevention means (10) can be omitted; and the variation of revolution speed of the developer holding means (3) due to the developer spill prevention means (10), can be prevented, so that undesirable unevenness of image density which tends to occur in a recorded image can be prevented.
This idea was realized and experiments were repeatedly made in such a manner that: in order to magnetically attract the developer to the developer stirring region, even in the region of both sides of the sleeve (31) which constitutes the developer holding means (3), the axial length of the magnetic conveying means (6) is made longer than the corresponding length of the magnetic means which is installed in the sleeve (31) of the developer holding means (3). According to the results of the experiments, it was confirmed that: when the axial length of the magnetic conveying means (6) is made a little longer than the corresponding length of the magnetic means inside the sleeve (31) of the developer holding means (3) by several millimeters, the leakage of the developer from the container in the developing device to the outside can be prevented, even if the above-described conventional developer spill prevention means (10) is eliminated.
The above-described third object of the present invention can be attained by the developing device which is provided with not only the composition to accomplish the first object of the present invention but also the following composition: one end (81), which is close to the developer stirring means (1), of the mechanical conveying means (8) is separated from the magnetic conveying means (6); and the gap between the end (81) and the magnetic conveying means (6) is not more than 1 mm.
It was also confirmed that: when the other end (82) of the mechanical conveying means (8) is connected with the developer removing means (5) in the above-described composition, the following advantages are acquired such that the developing device can be made compact and further the developer can be smoothly conveyed.
The developer holding means (3) of the developing device of the present invention is provided with the developer removing means (5) composed of a mechanical scraper and provided with the magnetic conveying means (6). The function of the former, the developer removing means (5), is to remove the used developer which is attracted onto the sleeve (31) of the developer holding means (3) with an extremely high efficiency. On the other hand, since the main components of developer are the carrier composed of fine particles of ferrite and the toner composed of coloring agents, the used developer (of which the toner amount is small and the carrier amount is large) is magnetically attracted to the magnetic conveying means (6) due to the magnetism of the carrier, that the developer is conveyed at least to the region of the magnetic conveying means (6) with a high efficiency.
It was found that the above-described used developer caused a problem in that: the used developer was accumulated around the magnetic removing means (6), so that the rotation of the drive means to drive the magnetic conveying means (6) was obstructed, which caused unevenness of images. In order to solve the problem described above, experiments were made in such a manner that: the relative distance between the mechanical conveying means (8) consisting of a scraper and the magnetic conveying means (6) were varied. As a result, it was confirmed that: when the distance between the mechanical conveying means (8) and the magnetic conveying means (6) was not zero and not more than 1 mm, the torque necessary to drive each drive means was small and stable as illustrated in FIG. 3. Consequently, it was confirmed that when the device was operated under the condition that the above-described distance was not zero and not more than 1 mm, unevenness of images was not caused.
Since the mechanical conveying means (8) is provided in the position close to the magnetic conveying means (6) in the developing device of the present invention in such a manner that the mechanical conveying means (8) does not come into contact with the magnetic conveying means (6) and the distance between means (8) and (6) is not more than 1 mm, the developer is not accumulated around the magnetic conveying means (6), so that the torque of each drive means is constant, thus toner concentration is constantly maintained and the occurrence of uneven images can be prevented.
A further means to accomplish the second object of the present invention is the composition to attain the second object, which was described before, and the composition which will be described as follows.
The magnetic flux density (B) of the magnet used in the developer leakage prevention means (102) is 200 to 400 gauss; the shortest distance (l) between the developer leakage prevention means (102) and the developer holding means (3) is 2 to 4 mm; and the relation between the magnetic flux density (B) of the developer leakage prevention means (102) and the above-described shortest distance (l) corresponding to (B) can be given by the equation of
0.006B+0.7≦l≦0.006B+1.1
where the unit of magnetic flux density (B) is expressed by gauss and the unit of the shortest distance (l) is expressed by mm.
The developing device of the present invention is provided with the developer removing means (5) composed of a mechanical scraper of which one end comes into contact with the developer holding means (3), and provided with the magnetic removing means (6). The former means, the developer removing means (5), can very effectively remove the used residual developer from the sleeve (31) of the developer holding means (3). On the other hand, since the main components of developer are the carrier composed of fine ferrite particles and the toner composed of coloring agents, the used developer is attracted by the magnetic conveying means (6) due to the magnetism of the carrier composed of ferrite, and conveyed to the region of the developer stirring means (1), so that the occurrence of uneven image density can be prevented.
The developing device according to the present invention, is provided with the developer leakage prevention means (102) (which is the main concept of the present invention), which is located in the position close to the lower edge (912) of the opening (91), and which is composed of a magnet placed in the position opposed to the magnet of the developer holding means (3), and the polarity of the magnet is reverse to that of the developer holding means (3). Accordingly, a magnetic field is formed between the magnets of the developer leakage prevention means (102) and the developer holding means (3).
The carrier particles which are contained in the developer placed in the above-described magnetic field, are magnetized and attracted with each other so that a body of attracted carrier is formed, and the developer holding means (3) and the developer leakage prevention means (102) are bridged by the body of attracted carrier. The bodies of attracted carrier are formed in parallel with each other, so that the shape of the bodies of attracted carrier is like a curtain, which can prevent the powdery developer from scattering outside of the casing means (9) of the developing device. Consequently, the leakage of developer can be prevented.
According to the results of experiments made by the inventors, it was found that: in order to positively prevent the leakage of the developer, the following equation must be satisfied
0.006B+0.7≦l≦0.006B+1.1
where l is the shortest distance between the developer holding means (3) and the developer leakage prevention means (102), and B is the magnetic density peculiar to the magnet which constitutes the developer leakage prevention means (102), wherein the unit of l is mm and the unit of B is gauss.
To explain in further detail, it was confirmed by the experiments made by the inventors that: when the value l was smaller than the lower limit value indicated by the above equation, the developer came out from the opening (91) and when the value l was larger than the upper limit value indicated by the above equation, the toner in the developer separated by the developer removing means (5) and was scattered from the opening (91).
The inventors have been studying the above-described fact from a physical viewpoint, but it can be speculated as follows.
When the value l is smaller than the lower limit value indicated by the above equation, the used toner left on the developer holding means (3) is dropped by the frictional motion and spilt from the opening (91).
When the value l is larger than the upper limit value indicated by the above equation, the intensity of the magnetic field formed between the magnetic pole of the developer holding means (3) and that of the developer leakage prevention means (102) is reduced, and the number of connected carrier bodies which bridge the magnetic means (32) with the developer leakage prevention means (102) of the present invention. As a result, the toner leakage preventing function is deteriorated and the splash of toner is caused.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a is a sectional view of an example of the present invention.
FIG. 1b is a sectional view of an example of the mechanical conveying means of the developing device of the present invention.
FIG. 1c is a sectional view of another example of the mechanical conveying means of the developing device of the present invention.
FIG. 1d is a sectional view of another example of the developing device of the present invention.
FIG. 1e is a sectional view of an example of the developer leakage prevention means used in the developing device of the present invention.
FIG. 1f is a sectional view of another example of the developer leakage prevention means used in the developing device of the present invention.
FIG. 1g is a side sectional view of another example of the developing device of the present invention.
FIG. 1h is a front view of an example of the developing device of the present invention, wherein the view is taken from the side of the opening.
FIG. 2a is a sectional view of a conventional developing device.
FIG. 2b is a side sectional view of another conventional developing device.
FIG. 2c is a front view of the conventional developing unit, wherein the view is taken from the side of the opening.
FIG. 3 is a graph showing the principle of the present invention, wherein the relation between the relative distance from a mechanical conveying means to a magnetic conveying means and the torque of each drive means is shown in the graph.
FIG. 4 is a graph which shows the relation between the magnetic flux density peculiar to the magnet constituting the developer leakage prevention means of the present invention, and the shortest distance from the developer holding means to the developer leakage prevention means.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, the first example of the developing device of the present invention will be explained as follows.
Refer to FIG. 1a.
In FIG. 1a, the numeral (1) is a developer stirring means which is composed of two screws. Toner is supplied to the developer stirring means from a toner supply means which is installed in the upper position of the developer stirring means. The supplied toner is conveyed by the right screw to the viewer's side. While the toner is being conveyed by the screw, a coloring agent conveying means (which will be called a carrier hereinafter), is supplied from the side of the screw (12), wherein the carrier is composed of particles having a diameter of approximately 50 mm, made from magnetic material. The supplied toner and carrier are stirred, uniformly mixed, and converted into a developer. This developer is conveyed to the subsequent process by the screw (12).
The numeral (2) is a developer supply means which may be composed of a cylindrical body of rotation, the surface of which is porous and rugged. The developer pushed out by the above-described screw (12) can be effectively conveyed by the action of the rugged surface.
The numeral (3) is a developer holding means which is composed of the sleeve (31) which is a cylindrical body of rotation, and the magnetic means (32) which is stationary and installed inside the sleeve (31). The function of the sleeve (31) is as follows: the sleeve (31) conveys the developer attracted onto its surface and supplies the developer to an image signal medium (for example an electrostatic photoreceptor drum) on which a latent image is formed; and the used developer is removed from the surface of the sleeve (31).
The numeral (4) is a height regulating means which is composed of a roller supported by a resilient member. The thickness of the developer layer formed on the sleeve (31) is regulated to a desirable value by the height regulating means.
The numeral (5) is a developer removing means of the present invention, the function of which is to mechanically remove the used developer from the surface of the sleeve (31). The developer removing means (5) is preferably provided with a resilient and sharp edge portion so that it can scrape off the attracted developer for a long period of time, and it is preferable that the developer removing means (5) is made from a hard and resilient material with high formability. In order to meet the requirements described above, urethane rubber, phosphor bronze and polyethylene terephthalate are preferably used.
The numeral (6) is a magnetic conveying means of the present invention which magnetically attracts the carrier removed from the sleeve (31) by the above-described developer removing means (5) and conveys the carrier to the subsequent process. Although the magnetic conveying means (6) is composed of a rotative body around the circumferential surface of which a plurality of magnets are provided, a moving magnetic field which moves in the direction of carrier movement may be utilized instead of the rotative magnetic body.
The numeral (8) is a mechanical conveying means of the present invention, which is located in the region between the magnetic conveying means (6) and the developer stirring means (1) and one end (81) of which is placed in the position close to the surface of the magnetic conveying means (6) or contacted with the surface. The function of the mechanical conveying means (8) is to mechanically remove the residual carrier from the surface of the magnetic conveying means (6) by one end (81). In this example, the other end (82) of the mechanical conveying means (8) is connected with the developer removing means (5). This mechanical conveying means (8) may be a non-magnetic body (83) made from stainless steel, aluminum or rubber, or otherwise the mechanical conveying means may be composed of a laminated body made of the non-magnetic body (83) and the magnetic body (84) (which is illustrated in FIG. 1c). In the former case, it is easy to remove the residual carrier from the magnetic conveying means (6). In the latter case, the carrier removed by one end (81) of the non-magnetic body (83) is positively attracted by the laminated magnetic body (84) so that the carrier can be effectively conveyed to the region of the developer stirring means (1). In any case, it is preferable that the above-described non-magnetic body (83) is resilient enough, provided with a sharp edge and the scraping efficiency can be maintained for a long period of time.
The carrier conveyed by the magnetic conveying means (6) and the mechanical conveying means (8) is conveyed to the region of the developer stirring means (1) and mixed with toner again so that the carrier can be converted into developer, the toner concentration of which is a desired value. The developer obtained in the manner described above is conveyed to the region of the developer supply means (2) by the screw (12).
The numeral (9) is a developing device body in which the above-described units are installed.
Referring now to the drawings, the second example of the developing device of the present invention will be explained as follows.
Refer to FIG. 1d.
In FIG. 1d, the numeral (1) is a developer stirring means, which is composed of two screws (11) and (12). Toner is successively supplied from a toner supply means (not illustrated in the drawing) to the screw (11) illustrated on the right side in the drawing. On the other hand, carrier is successively supplied from the screw (12) illustrated on the left side in the drawing to the screw (11) illustrated on the right side. The supplied toner and carrier are uniformly stirred and mixed by the screws (11) and (12) so that they are converted into developer. The converted developer is conveyed by the screw (12) to the region of the developer supply means (2) which will be described as follows.
The developer supply means (2) is composed of, for example, a cylindrical rotative body of which surface is porous and rugged. The developer supplied by the above-described developer stirring means (1) is effectively conveyed by the developer supply means (2) of which surface is rugged, in the left direction in the drawing.
The numeral (3) is a developer holding means which is composed of the sleeve (31) which is a cylindrical body of rotation, and the magnetic means (32) which is stationary and installed inside the sleeve (31). The function of the sleeve (31) is as follows: the sleeve (31) conveys the developer attracted onto its surface and supplies the developer to an image signal medium (for example an electrostatic photoreceptor drum) on which a latent image is formed; and the used developer is removed from the surface of the sleeve (31).
The function of the magnetic means (32) is as follows: the developer conveyed by the developer supply means (2) is attracted onto the sleeve (31) by the action of the magnetic means (32); the attracted condition is maintained; and the used developer is released from the sleeve (31). In the region in which the developer is released from the surface of the sleeve (31), there is no magnetic pole, and at the end of the region in which the developer is to be attracted, a magnetic pole, the polarity of which is the same as that of the developer, is installed.
The numeral (4) is a height regulating means which is composed of a roller supported by a resilient member. The thickness of the developer layer formed on the sleeve (31) is regulated to a desirable value by the height regulating means.
The numeral (5) is a developer removing means of the present invention, the function of which is to mechanically remove the used developer from the surface of the sleeve (31). The developer removing means (5) is preferably provided with a resilient and sharp edge portion so that it can scrape off the attracted developer for a long period of time, and it is preferable that the developer removing means (5) is made from a hard and resilient material with high formability. In order to meet the requirements described above, urethane rubber, phosphor bronze and polyethylene terephthalate are preferably used.
The numeral (6) is a magnetic conveying means which magnetically attracts the developer (the amount of toner of which is small and the amount of carrier is relatively large) removed from the sleeve (31) by the above-described developer removing means (5) and conveys the carrier to the region of the developer stirring means (1). Although the magnetic removing means (6) is composed of a rotative body around the circumferential surface of which a plurality of magnets are provided, a moving magnetic field which moves in the direction of the used developer movement may be utilized instead of the rotative magnetic body.
As described above, the used developer (the toner amount of which is small and the carrier amount is relatively large) which was conveyed to the region of the developer stirring means (1), is mixed with toner and converted into developer of which toner concentration is desirably made uniform. Then the developer is conveyed to the region of the developer supply means (2) by the screw (12).
The numeral (9) is a casing means in which each means described above is installed. The numeral (91) is an opening which is formed at one end of the casing means (9). A portion of the developer holding means (3) is protruded from the opening (91) and opposed to an image signal medium (not illustrated in the drawing). At the above-described opening (91), the gap between the upper edge (911) of the casing means (9) and the developer holding means (3), and the gap between the lower edge (912) and the developer holding means (3) are approximately set to 1 mm.
The numeral (102) is a developer leakage prevention means of the present invention. This developer leakage prevention means (102) is composed of a magnet, the polarity of which is reverse to that of the magnet of the developer holding means (3) opposed to the developer leakage prevention means (103). The developer leakage prevention means (102) is located in the position between the developer removing means (5) and the lower edge (912) of the opening (91). A magnetic field is formed between both magnetic poles which have the polarity reverse to each other.
According to the experiments made by the inventors, it was confirmed that: the carrier located in the magnetic field is attracted with each other and formed to a connected body, which bridges the developer holding means (3) with the developer leakage prevention means (102). Further, it was confirmed that: a plurality of connected bodies of attracted carrier were aligned in parallel with each other and the shape of which was like a curtain, so that the scatter and leakage of the powdery developer (toner) could be effectively prevented. This developer leakage prevention means (102) may be composed of a rubber-magnet and the magnet composition may be as shown in FIG. 1e, and may be as shown in FIG. 1f. The developer leakage prevention means (102) illustrated in FIG. 1e is the most practical since the positioning can be easily conducted.
The leakage of developer from the casing means (9) is more positively prevented by using the developer leakage prevention means (102) together with the conventional developer spill prevention means (10) described in FIG. 2b and FIG. 2c.
Referring now to the drawings, the third example of the developing device according to the present invention will be explained explained as follows.
Refer to FIG. 1g and FIG. 1h.
FIG. 1g is a side sectional view of this example and FIG. 1h is a front view of this example which is taken from the direction of an opening.
In the drawing, the numeral (1) is a developer stirring means, which is composed of two screws (11) and (12) in this example, and which conveys the developer consisting of carrier and toner to the developer supply means (2).
The developer supply means (2) is composed of, for example, a cylindrical rotative body of which surface is porous and rugged. The developer supplied by the above-described developer stirring means (1) is effectively conveyed by the developer supply means (2) of which surface is rugged, in the left direction in the drawing.
The numeral (3) is a developer holding means which is composed of the sleeve (31) which is a cylindrical body of rotation, and the magnetic means (32) which is stationary and installed inside the sleeve (31). The middle portion of the circumferential surface of the sleeve (31) is a finely rugged sand-blasted surface (311) which was processed by sand-blasting. Smooth surfaces (312) are continuously connected with both sides of the blasted surface (311).
In this case, generally speaking, the axial length of the blasted surface (311) of the developer holding means (3) is approximately the same as the corresponding length of the magnetic means (32). The function of the blasted surface (311) is to positively hold the developer using the friction of the rugged surface. The developer holding means (3) supplies the developer attracted onto the blasted surface (311) of the sleeve (31) to a latent image formed on an image signal medium (for example, an electrostatic photoreceptor drum), and removes the used developer. After removing, the developer holding means (3) conveys the used developer to the region of the developer stirring means (1). On the other hand, the function of the magnetic means (32) is to hold the developer on the sleeve (31) while the toner is supplied to a latent image formed on the photoreceptor (in other words, while the latent image is being developed), and to release the used developer from the above-described sleeve (31) after development.
The numeral (4) is a height regulating means which is composed of a roller supported though a resilient member. The thickness of the developer layer formed on the surface of the sleeve (31) is regulated to a predetermined thickness by the height regulating means (4).
The numeral (5) is a developer removing means of the present invention, the function of which is to mechanically remove the used developer from the surface of the sleeve (31). The developer removing means (5) is provided with a resilient and sharp edge portion so that it can positively scrape off all the attracted developer. Accordingly, the occurrence of uneven image density can be prevented.
The numeral (6) is a magnetic conveying means which magnetically attracts the developer (the amount of toner of which is small and the amount of carrier is relatively large) removed from the sleeve (31) by the above-described developer removing means (5) and conveys the carrier to the region of the developer stirring means (1). Although the magnetic removing means (6) is composed of a rotative body around the circumferential surface of which a plurality of magnets are provided, a moving magnetic field which moves in the direction of the used developer movement may be utilized instead of the rotative magnetic body.
The axial length of the magnetic conveying means (6) is related to the concept of the present invention. In the case of the apparatus of the present invention, the axial length of the magnetic conveying means (6) is made longer than the corresponding length of the magnetic means (32) which is provided inside the sleeve (31). As a result, the developer which is going to leak out from the position close to the circumferential surfaces of both sides of the sleeve (31), is attracted by the above-described magnetic conveying means (6), so that the developer can be prevented from leaking out from the developing container.
The numeral (9) is a casing means in which each means is installed. The numeral (91) is an opening which is formed at the end of the casing means (9). A portion of the developer holding means (3) is protruded from the opening (91) and opposed to an image signal medium (not illustrated in the drawing). At the above-described opening (91), the gap between the upper edge (911) of the casing means (9) and the developer holding means (3), and the gap between the lower edge (912) and the developer holding means (3) are approximately set to 1 mm.
Referring now to the drawings, the fourth example of the developing device of the present invention will be explained as follows.
Refer to FIG. 1a.
In the drawing, the numeral (1) is a developer stirring means, which is composed of two screws (11) and (12) in this example. Toner is successively supplied from a toner supply means (not illustrated in the drawing) to the screw (11) illustrated on the right side in the drawing. The supplied toner is mixed with the carrier circulating in the developing device so that the developer is prepared.
The developer supply means (2) is composed of, for example, a cylindrical rotative body of which surface is porous and rugged. The developer supplied by the above-described screw (12) is conveyed by the developer supply means (2) to the region of the developer holding means (3).
The numeral (3) is a developer holding means which is composed of the sleeve (31) which is a cylindrical body of rotation, and the magnetic means (32) which is stationary and installed inside the sleeve (31). The function of the sleeve (31) is as follows: the sleeve (31) conveys the developer attracted onto its surface and supplies the developer to an image signal medium (for example an electrostatic photoreceptor drum) on which a latent image is formed; and the used developer is removed from the surface of the sleeve (31).
The function of the magnetic means (32) is to hold the developer on the sleeve (31) while the toner is supplied to a latent image formed on the photoreceptor (in other words, while the latent image is being developed), and to release the used developer from the above-described sleeve (31) after development.
The numeral (4) is a height regulating means which is composed of a roller supported though a resilient member. The thickness of the developer layer formed on the surface of the sleeve (31) is regulated to a predetermined thickness by the height regulating means (4).
The numeral (5) is a developer removing means of the present invention, the function of which is to mechanically remove the used developer from the surface of the sleeve (31). The developer removing means (5) is preferably provided with a resilient and sharp edge portion so that it can scrape off the attracted developer for a long period of time, and it is preferable that the developer removing means (5) is made from a hard and resilient material with high formability. In order to meet the requirements described above, urethane rubber, phosphor bronze and polyethylene terephthalate are preferably used.
The numeral (6) is a magnetic conveying means which magnetically attracts the developer removed from the sleeve (31) by the above-described developer removing means (5) and conveys the carrier to the region of the developer stirring means (1). Although the magnetic removing means (6) is composed of a rotative body around the circumferential surface of which a plurality of magnets are provided, a moving magnetic field which moves in the direction of the used developer movement may be utilized instead of the rotative magnetic body.
The numeral (8) is the mechanical conveying means of the present invention. The mechanical conveying means (8) is placed between the magnetic conveying means (6) and the developer stirring means (1). One end (81) of mechanical conveying means (8) is located in the position close to the magnetic conveying means (6). The distance between one end (81) of the mechanical conveying means which is close to the developer stirring means (1), and the magnetic conveying means (6) is not more than 1 mm, which is the concept of the present invention.
If the other end (82) of the mechanical conveying means (8) is connected with the developer removing means (5), the developer can be smoothly conveyed.
This mechanical conveying means (8) can be composed of a non-magnetic body made from stainless steel, aluminum and rubber.
The carrier conveyed by the magnetic conveying means (6) and the mechanical conveying means (8) is conveyed again to the region of the developer stirring means (1), and uniformly mixed again with the toner so that the carrier is converted into a developer having a predetermined toner concentration. After that, the developer is conveyed to the region of the developer supply means (2) by the screw (12).
The numeral (9) is a casing means in which the above-described units are installed.
Referring now to the drawings, the fifth example of the developing device of the present invention will be described as follows.
Refer to FIG. 1d.
In FIG. 1d, the numeral (1) is a developer stirring means which is composed of two screws. Toner is supplied to the developer stirring means from a toner supply means which is installed in the upper position of the developer stirring means. The supplied toner is conveyed by the right screw to the viewer's side. While the toner is being conveyed by the screw, a carrier is supplied. The supplied toner and carrier are stirred, uniformly mixed, and converted into a developer.
The numeral (2) is a developer supply means which conveys the developer stirred by the developer stirring means (1) to the region of the developer holding means (3).
The numeral (3) is a developer holding means which is composed of the sleeve (31) which is a cylindrical body of rotation, and the magnetic means (32) which is stationary and installed inside the sleeve (31). The function of the sleeve (31) is as follows: the sleeve (31) conveys the developer attracted onto its surface and supplies the developer to an image signal medium (for example an electrostatic photoreceptor drum) on which a latent image is formed; and the used developer is removed from the surface of the sleeve (31).
The magnetic means (32) has the following function: it attracts the developer conveyed by the developer supply means (2) onto the sleeve (31), holds the attracting condition, and releases the used developer from the sleeve (31).
The numeral (4) is a height regulating means which is composed of a roller supported by a resilient member. The thickness of the developer layer formed on the sleeve (31) is regulated to a desirable value by the developer layer thickness regulating means.
The numeral (5) is a developer removing means of the present invention, the function of which is to mechanically remove the used developer (in which the ratio of the carrier to the toner is not uniform with regard to the regions on the sleeve (31) of the developer holding means (3)) from the surface of the sleeve (31). The developer removing means (5) is provided with a resilient and sharp edge portion, and the developer removing means (5) is made from a hard and resilient material with high formability. In order to meet the requirements described above, urethane rubber, phosphor bronze and polyethylene terephthalate are preferably used. The effect of this developer removing means (5) is as follows: after development, all the used developer is removed from the developer holding means (3), so that the occurrence of uneven image density can be effectively prevented.
The numeral (6) is a magnetic conveying means of the present invention which magnetically attracts the used developer removed from the sleeve (31) by the above-described developer removing means (5) and conveys the carrier to the subsequent process. Although the magnetic removing means (6) is composed of a rotative body around the circumferential surface of which a plurality of magnets are provided, a moving magnetic field which moves in the direction of carrier movement may be utilized instead of the rotative magnetic body.
The used developer which has been conveyed by the magnetic conveying means (6) is conveyed to the region of the developer stirring means (1), and mixed again with the toner so that the ratio of the toner to carrier can be adjusted. The developer prepared in the manner described above is conveyed to the region of the developer supply means (2) by the developer stirring means (1).
The numeral (9) is a casing means in which each means described above is installed. The numeral (91) is an opening which is formed at one end of the casing means (9). A portion of the developer holding means (3) is protruded from the opening (91) and opposed to an image signal medium (not illustrated in the drawing). At the above-described opening (91), the gap between the upper edge (911) of the casing means (9) and the developer holding means (3), and the gap between the lower edge (912) and the developer holding means (3) are approximately set to 1 mm.
The numeral (102) is a developer leakage prevention means of the present invention. This developer leakage prevention means (102) is composed of, for example, a rubber magnet. This developer leakage prevention means (102) is composed of a magnet, the polarity of which is reverse to that of the magnet of the magnetic means (32), wherein the magnet of the developer leakage prevention means (102) is opposed to that of the magnetic means (32). The magnetized carrier body connects both magnetic poles which are opposed to each other, and the polarities of them are reverse to each other, so that the carrier contained in the developer can be prevented from scattering from the opening (91).
In order to positively attain the object of preventing the carrier contained in the developer from scattering, there exists a necessary condition between the shortest distance l from the developer holding means (3) to the developer leakage prevention means (102), and the magnetic flux density B which is peculiar to the magnet constituting the developer leakage prevention means (102). The necessary condition is shown as follows, which is the concept of the present invention, wherein the unit of magnetic flux density B is gauss and that of the shortest distance l is mm.
0.006B+0.7≦l≦0.006B+1.1
When the value l is smaller than the lower limit value indicated by the above equation, the developer is spewed from the opening (91) and when the value l is larger than the upper limit value indicated by the above equation, the toner in the developer is scattered from the opening (91). FIG. 4 is a graph which shows the relation between the shortest distance l and the magnetic flux density B.
As explained above, since the developing device of the present invention is provided with a developer removing means which mechanically removes the used developer from the sleeve constituting the developer holding means, all of the used developer (in which the amount of carrier is large and the amount of toner is small) is almost completely removed from the sleeve and new developer of which toner density is uniform is attracted onto the sleeve. Development is conducted by the developer of uniform density, so that the occurrence of uneven image density can be prevented. Since the developing device of the present invention is provided with a magnetic conveying means and a mechanical conveying means, the carrier removed from the surface of the sleeve by the above-described developer removing means, is magnetically attracted by the magnetic conveying means and positively conveyed to the region of the developer stirring means. The residual toner left on the surface of the magnetic removing means is mechanically removed by the mechanical conveying means and conveyed, so that the conveyance of carrier is more positively performed and the developer is more smoothly circulated.
Further, the developer leakage prevention means is installed in the position close to the lower edge of the opening provided to the casing means of the developing device of the present invention, which developer leakage prevention means is composed of a magnet, the polarity of which is reverse to that of the magnet of the magnetic means, wherein the magnet of the developer leakage prevention means is opposed to that of the magnetic means. Consequently, the used developer, especially the carrier, is magnetized in the region of the developer leakage prevention means, and the carrier is attracted with each other and the connected body of attracted carrier is formed. The developer holding means and the developer leakage prevention means are bridged by the connected body of attracted carrier. As a result, the powdery developer can be effectively prevented from scattering from the casing means. Accordingly, the apparatus and recording papers can be prevented from being stained by the developer.
Further, the apparatus of the present invention is advantageous as follows. Since the developing device of the invention is provided with a developer removing means composed of a member made from a hard elastic material having sharp edges, almost all of the used developer attracted onto the sleeve constituting a developer holding means can be completely removed and a developer having a desirable ratio of toner to carrier is newly attracted. The following image forming (development and transfer) is conducted by this developer having a desirable ratio of toner to carrier. As a result, the occurrence of uneven image density can be prevented.
The developing device of the present invention is also provided with a magnetic conveying means. The axial length of the magnetic conveying means is a little longer (by several millimeter) than the corresponding length of the magnetic means installed inside the sleeve of the developer holding means, so that the leakage of the developer from the container can be prevented and the developer can be smoothly circulated in the developing device. As explained above, the corresponding length of the magnetic means installed inside the sleeve of the developer holding means is approximately the same as the length (which is the blasted width) of the region of which the surface is finely rugged.
According to the results of experiments conducted by the inventors, the following fact was confirmed: the developing device of the present invention can be effectively applied not only to the case in which a two-component developer is used but also to the case in which one-component developer is used.
Further, one end of the mechanical conveying means is located in the position close to the developer stirring means, the distance of which is not more than 1 mm, so that the occurrence of uneven image density is effectively prevented and the used developer removed from the developer holding means can be smoothly conveyed to the region of the magnetic conveying means, and further the developer does not remain in the region of the magnetic conveying means too long. Accordingly, the torque of each drive means can be constantly maintained regardless of the amount of the developer which exists in the position close to the magnetic conveying means. Therefore, the amount of developer attracted onto the unit surface of the developer holding means can be kept constant and uniform, so that the unevenness of image can be prevented.
In the developing device of the present invention, when the other end of the mechanical conveying means is connected with the developer removing means, the developer can be further smoothly conveyed.
Furthermore, the developing device of the present invention is composed as follows: a developer leakage prevention means composed of a magnet is provided in the position close to the opening of the container of the developing device; the above-described magnet, the polarity of which is reverse to that of the developer holding means, is opposed to the magnet of the developer holding means; and further the relation between the shortest distance l from the developer leakage prevention means to the developer holding means, and magnetic flux density B peculiar to the magnet constituting the developer leakage prevention means, can be expressed by the following inequality,
0.006B+0.7≦l≦0.006B+1.1
where the unit of magnetic flux density is gauss and the unit of the shortest distance l is mm. Accordingly, the scatter and leakage of developer from the opening of the developing device can be effectively prevented, so that the developing device can be prevented from being stained. | A developing device for use in an image recording apparatus, comprising: a developer stirrer which stirs toner and carrier in order to prepare the compostion of developer; a developer supplier which supplies the developer prepared by the developer stirrer; a developer holder which attracts the developer supplied by the developer supplier onto its surface, conveys the developer to the development region; a height regulator which regulates the layer thickness of the developer attracted onto the surface of the developer holder; a developer remover which removes the residual developer from the surface of the developer holder after development; a magnetic conveyor which conveys the developer removed from the developer holder to the region of the developer stirrer; and a mechanical conveyor which is placed in the region between the magnetic conveyor and the developer stirrer, which removes the developer attracted onto the surface of the magnetic conveyor, and moves the removed developer toward the region between the magnetic carrier conveyor and the developer stirrer. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 08/521,350 filed Aug. 29, 1995 of Hill et al. entitled "Printing Assembly With Discrete Sheet Load Enhancement Apparatus and Method" which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to card insertion systems and, more particularly, to modular apparatus and methods for making and using such insertion systems.
2. Description of the related art including information disclosed under 37 C.F.R. 1.97-1.99
Card insertion systems which function to automatically insert one or more credit cards into matching carrier forms are well known.
A disadvantage of known insertion systems is their lack of versatility with respect to printing of the carrier forms. In some systems, the inserters are capable of working only in conjunction with preprinted carrier forms that are fed in continuous fan-folded form to a burster comprising part of the system which is operated to separate the preprinted forms into separated discrete carrier forms which, in turn, are fed seriatim to the inserter one at a time for receipt of inserted cards. These preprinted form systems are not capable of operating in conjunction with in-line carrier form printers.
In other insertion systems, the inserters are contained in a single cabinet with an in-line printer and other apparatus to form a complete card package production system. These card package production systems are not compatible for use with single sheet preprinted carrier forms and operate only with continuous forms.
SUMMARY OF THE INVENTION
It is therefore the principal object of the present invention to overcome the disadvantageous lack of versatility of known card insertion systems by providing modular apparatus and methods of making and using an insertion system in which both preprinted carrier forms and in-line printed carrier forms are capable of being used.
Accordingly, it is an object of the present invention to provide a modular insertion system with a free standing inserter module for inserting cards into matching carrier forms including a carrier inlet for receiving separate carrier forms located at a preselected elevation, a free standing printer module for printing carrier forms with a carrier form outlet located at a preselected elevation substantially the same as that of the carrier inlet of the inserter module to enable direct insertion of printed forms ejected from the printer outlet into the carrier inlet of the inserter when the inserter module and printer module are positioned in relative cooperative adjacent alignment, and a free standing burster for separating preprinted continuous carrier form stock into bursted separate carriers with a bursted carrier form outlet at a preselected elevation substantially the same as that of the carrier inlet of the inserter to enable direct insertion of the preprinted forms ejected from the burster outlet into the carrier inlet of the inserter module when the inserter module and printer module are positioned in relative cooperative adjacent alignment.
Also, the object of the invention is obtained by provision of a method of making a card insertion system, comprising the steps of (1) interfacing an inserter module with a printer to enable printing of blank carrier forms on an on-line basis immediately prior to provision of the carrier forms to the inserter and (2) alternatively, interfacing the inserter module directly with a burster to enable provision of off-line preprinted carrier forms to the inserter module at a rate relatively more rapid than at which the printer can print carrier forms on-line.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing objects and advantageous features of the invention will be explained in greater detail and others will be made apparent from the detailed description of the preferred embodiment of the present invention which is given with reference to the several figures of the drawing, in which:
FIG. 1A is a schematic illustration of a preferred embodiment of the modular card insertion system of the present invention in which carrier forms are printed in line;
FIG. 1B is a schematic illustration of the modular card insertion system of the present invention in which preprinted continuous carrier forms are fed to the inserter module;
FIG. 2 is a functional block diagram of the discrete blank carrier form source module of FIG. 1A;
FIG. 3 is a perspective view of a preferred embodiment of the modular insertion inserter system of FIG. 1A;
FIG. 4A is a simplified schematic side elevation of the modular insertion system of FIGS. 1A and 3 in which discrete blank carrier forms are obtained from a source of blank continuous carrier form supply and a carrier forms burster as shown in functional block form in FIG. 2;
FIG. 4B is a side elevational view of the modular inserter similar to that of FIG. 4A but in which the burster and continuous carrier forms have been replaced with a discrete carrier form supply which is fed to the printer;
FIG. 5 is a simplified side elevational view of the modular insertion system shown in schematic form in FIG. 1B in which the forms are provided to the inserter from a preprinted continuous carrier form supply which are first passed through a free standing burster to provide individual separated preprinted forms to the inserter module.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the modular card insertion system 10 of the present invention is collectively shown in both FIGS. 1A and 1B. In FIG. 1A the modular card insertion system 10 is configured for on-line printing of the carrier forms and includes a free standing inserter module 12 for inserting cards into matching carrier forms. It includes a carrier inlet 14 for receiving separate carrier forms into which the cards are to be inserted. The carrier inlet 14 is located at a preselected elevation 14' above a underlying floor surface 16 upon which the inserter 12 is supported, preferably on wheels 18, or other means for facilitating translational movement across the floor 16 such as glides or casters with levelers. Adjacent to the inserter 12 is a free standing discrete carrier form printer module 20 for printing carrier forms 15. The discrete carrier form printer module 20 has a carrier form outlet 22 located at a preselected elevation 22' above the floor 16 which is substantially the same as elevation 14' of the carrier inlet 14 of the inserter module 12. The discrete form printer module 20, like the inserter module 12, is preferably mounted on wheels 24 or the like to facilitate movement into cooperative alignment with the inserter module 12 as shown in FIG. 1A. When aligned with levelers for wheels 24, as shown in FIG. 1A, a carrier from the discrete carrier form printer module is enabled to pass directly from the carrier outlet 22 into the carrier 22 of the discrete carrier form printer module 20 directly into the inlet 14 of the inserter module 12.
The discrete carrier form printer module 20 has an inlet 26 located at a preselected elevation 26' above the floor surface 16. The inlet 26 receives carriers 15 from an outlet 28 of a discrete blank carrier form source module 30. The outlet 28 is located at a preselected elevation 28' which is substantially identical to preselected elevation 26' of the printer module inlet 26. When the discrete blank carrier form source module is properly positioned in relative cooperative adjacent alignment as shown in FIG. 1A, carrier forms 15 from outlet 28 are enabled to be inserted directly into the inlet 26.
Referring now to FIG. 1B, the modular card insertion system 10 of the present invention is also seen to include in an alternative configuration to that of FIG. 1A a free standing burster 32 which functions to burst, or separate, carrier forms 15 from a preprinted continuous carrier form supply module 34 into to individual separate carrier forms. Pin hole strips on the continuous forms supply are also removed. In the preferred embodiment, the preprinted continuous carrier form supply module 34 consists of a stack of fan-folded interconnected carrier forms. These are fed to the inlet 36 of the free standing burster module. The free standing burster module 32 then separates these carriers and outputs separate discrete carriers 15 at its carrier outlet 38.
The carrier outlet 38 is at a preselected elevation 38' which is substantially identical to the preselected elevation 14' and thus also substantially equal to the preselected elevation 22' of the outlet 22 of the discrete carrier form printer module 20. The free standing burster module also is mounted on wheels 40 or other means for facilitating translational movement across the floor 16 which includes a leveler. When the free standing burster module 32 and the inserter module 12 are positioned in relative cooperative adjacent alignment as shown in FIG. 1B, the free standing burster module 32 is enabled to directly insert discrete carrier forms 15 into the carrier inlet 14 of inserter module 12 in lieu of the discrete carrier form printer module doing so. The discrete carrier form printer module, because it is required to print the carrier forms, operates at an approximate speed of 32 printed carrier forms per minute. When it is desired to or needed to print blank carrier forms in line during the insertion process, the discrete carrier form printer module 20 and the discrete blank carrier form source module associated therewith are used in conjunction with the inserter module 12 as shown in FIG. 1A. However, when preprinted continuous carrier forms are available, then the discrete carrier form printer module 20 is moved out of alignment with the inserter 12 and the free standing burster module 32 is moved into alignment. The inserter 12, when operating with the burster 32, operates at a relatively higher rate of approximately forty carriers per minute.
Referring to FIG. 2, the discrete blank carrier form source module 30 preferably includes a carrier forms burster 42 which separates blank continuous carrier forms from a blank continuous carrier form supply module 44 which are fed to it at an inlet 46 of the carrier forms burster 42. The carrier forms burster 42 has a carrier outlet 48 corresponding to outlet 28, FIG. 1A, which is at the preselected elevation 28' equal to the preselected elevation 26' of the discrete form carrier form printer module 20 to facilitate direct insertion from the carrier forms burster 42 of carriers 15 into the inlet 26.
Referring to FIG. 3 in the preferred embodiment, the inserter module 10 is seen in conjunction with a discrete carrier form printer module 20 to which is releasably mounted a carrier form burster module 42 which includes a shelf 48 on which is carried a supply of blank continuous forms 44 fed to the inlet 46. In turn, the carrier form burster module 42 is removably mounted to a shelf 50 of the carrier form printer 20.
Referring to FIG. 4A, the modular card insertion system 10 in the configuration illustrated in FIG. 1A and is shown to have the printer module 20 with a pair of pinch rollers 22 at the printer inlet 26 while the inserter module 12 has a pair of pinch rollers 54 at the inlet 14 which receives carriers from a carrier outlet guide 56 of the printer module 20. The burster module 42 also has a pair of pinch rollers 58 at its inlet for receipt of the continuous loosely connected carrier forms 15 of the blank continuous carrier form supply module 44.
Referring to FIG. 4B in lieu of the carrier form burster module 42 being mounted on the shelf 50 of printer 20, the printer is provided with a discrete carrier form module 60 which contains a stack of discrete blank carrier forms 62.
Referring now to FIG. 5, the modular card insertion system 10 is schematically illustrated as a side elevational view showing the free standing burster module 32 feeding the inserter module 12 with discrete carrier forms as described above with the configuration shown in FIG. 1B. The blank continuous carrier form supply module 44 contains fan-folded continuous carrier forms which are fed to an inlet of the free standing burster module 32 at its inlet 36 which has a pair of pinch rollers 64 while at the outlet 38 of the free standing burster module 32, another pair of pinch rollers at inlet 14.
It should be appreciated that to the extent the details of the various apparatus referred to or shown herein are not described or shown herein, they form no part of the printed invention. If such details are desired, reference should be made to one or more of U.S. Pat. No. 5,388,815 issued Feb. 14, 1995 to Hill et al. entitled "Embossed Card Package Production System With Modular Inserters For Multiple Forms"; U.S. Pat. No. 5,433,364 issued Jul. 18, 1995 entitled "Card Package Production System With Burster and Carrier Verification Apparatus"; U.S. Pat. No. 5,494,544 issued on Feb. 27, 1996 to Hill et al. entitled "Automatic Verified Embossed Card Package Production Methods"; U.S. Pat. No. 5,509,886 issued Apr. 23, 1996 to Hill et al. entitled "Card Package Production System With Modular Carrier Folding Apparatus For Multiple Forms"; and U.S. Pat. No. 5,541,395 issued Jul. 30, 1996 to Hill et al. entitled "Card Package Production System With Burster and Code Reader". Reference should also be made to U.S. patent application Ser. No. 08/313,548 filed Sep. 23, 1994 (which is a continuation of filewrapper of Ser. No. 08/036,436 filed Mar. 24, 1993) of Hill et al. entitled "Card Carrier Forms For Automated Embossed Card Package Production System"; U.S. provisional patent application Serial No. 08/047,195 (DYN-11) of Hill et al. entitled "Card Inserter With Carrier Folding Apparatus and Method" filed contemporaneously herewith; U.S. provisional patent application Ser. No. 60/047,190 (DYN-12) of Hill et al. entitled "Automatic Card Insertion System With Card Multireader and Method" filed contemporaneously herewith; U.S. patent application Ser. No. 08/859,295 (DYN-14) of Hill et al. entitled "Printer With Discrete Sheet Load Enhancement Apparatus and Method" filed contemporaneously herewith; and U.S. provisional patent application Ser. No. 60/047,189 (DYN-15) of Hill et al. entitled "Card Package Production System With A Multireader Card Track and Method" filed contemporaneously herewith. All these patents and patent applications are hereby incorporated by reference.
While a detailed description of the preferred embodiment of the invention has been given, it should be appreciated that many variations can be made thereto without departing from the scope of the invention as set forth in the appended claims. | A card insertion system (10) and method in which a free standing inserter module (12) for inserting cards into carriers has a carrier inlet (14) at a preselected elevation (14') for selectively, alternatively interfacing with, and receiving carrier forms (15) from, a free standing in-line carrier form printer module (20) with a carrier form outlet (22) at the preselected elevation (22') to feed in-line carrier forms to the printer inlet when the burster module (32) and printer module (20) are positioned in relative cooperate adjacent alignment and in which a free standing burster (32) for separating preprinted continuous carrier form stock into bursted separate carriers with a bursted carrier form outlet (38) at a preselected elevation (38') substantially the same as that of the carrier inlet (14) of the inserter (12) to enable direct insertion of the preprinted forms ejected from the burster outlet (38) into the carrier inlet (14) of the inserter module (12) when the inserter module (12) and printer module (20) are positioned in relative cooperative adjacent alignment. | 8 |
FIELD OF THE INVENTION
The invention provides a method for bone removal and trimming of products such as fish fillets with a new method based on cutting with a water beam. This gives possibilities for new and more valuable products, such as neck pieces with skin, than with conventional methods due to known position of the bones.
BACKGROUND
A continuous development of food processing, such as fish products, has taken place in the past decades. A big effort has been put into increasing utilization and value of the product as well as meeting demands for higher throughput and efficiency in processing.
Traditional methods for bone removal include manual trimming fish fillets as well as removal of pin bones. These manual methods are labour intense and time consuming and such processing is giving way in competition to methods based on automated and more efficient processing.
A technology has been developed for searching for bones in fish fillets, analyses, locates and removes the bones with gripping devices, which tears the bones from the fillet. The efficiency of such device, because results of bone removal, has not shown to be satisfactory.
Another disadvantage associated with this technology is that the fish fillets are skinned using traditional skinning devices, which causes deforming of the fillets, gapping occurs making location of pin bones inaccurate as well as increasing the risk of bones moving in the fillet and ending up in locations where the device has a difficulty in finding and locating the bones. The result of this has been manual searching and locating remaining bones using expensive bone scanning device. Such device uses x-ray scanning for locating the bones and a certain group of consumers refuses products that have been treated with x-ray.
Separation of food products, such as fish fillets, chicken fillets, and many others, by using water jet cutting is known in the art. U.S. Pat. No. 4,962,568 discloses how food products are cut to predetermined portion sizes or to predetermined profile shapes, by scanning the items with a camera capable as they move on a conveyor. The camera provides a programmed computer with dimensional data, and utilizes the computer to control the operation of a plurality of high pressure water jet cutters to cut the food products to reduced sizes as dictated by the computer program.
U.S. Pat. No. 5,551,190 discloses an arrangement for fluid jet cutting of food products. The arrangement comprises a movable nozzle which is on a frame. The plant for fluid jet cutting comprises a belt conveyor for moving the products, a device for analyzing the characteristics of the products to be cut, and a device for controlling the operation of the fluid jet arrangement for cutting the products on the conveyor in response to commands from the analyzing device.
Prior art arrangements using water jet cutting are not considered optimal for processes such as removing pin bones from fish fillets, as the back flush from the cutting water beam does interrupt the precise location of pin bones in fillets and the cut in the meat is not sharp enough and close enough to the pin bones. This is because the flesh in traditional state is delicate with soft texture and deforms during cut by the water jet beam. This leads to reduction in yield and value when processing fillets. Moreover, the known water jet arrangements are quite complicated.
Conventional methods including methods using water jet cutting are based on skinning the fillets before bone removal preventing processing valuable products with the skin attached, such as loin pieces or salted flap with skin. Further more traditional skinning causes deforming of the fillets and gapping occurs making location of pin bones inaccurate as well as increasing the risk of movement of bones in the fillet giving problems finding and locating the bones.
U.S. Pat. No. 6,825,446 discloses a technology which can be used for cooling the products, such as fish fillets, to the under-cooled state by using the Combined Blast and Contact cooling method. This gives the necessary precise control of the cooling and an effective cooling for bringing the fillets to the under-cooled state.
Conventional methods are therefore limited to providing skinless products. Conventional methods have a further disadvantage in that the temperature of the product increases during the processing decreasing storage life and quality. These conventional methods have been used until now instead of the manual way of removing pin bones and trimming fish fillets using a complex and expensive devices as well as involving shortage of efficiency to give satisfactory results.
SUMMARY OF THE INVENTION
It is the aim of the present invention to provide a method, which can be used for processing fish fillets, such as cutting and removal of pin bones, which increases efficiency of the processing and value of the product. Further more it is the aim of the invention to process fillets in a way that allows more precise cuts giving improved yield than prior methods.
It is further an object of the present invention to increase efficiency of processing products and solve problems of processing products in a more efficient way than prior methods.
The invention provides a method for bone removal and trimming of products such as fish fillets with a new method based on cutting with a water beam where the product is in an under-cooled state. The product, for example a fish fillet, is cooled down to the phase transition of freezing. The product is feed onto a conveyor belt which transports the product to a camera with a laser scanner device which provides a three dimensional model of the product and compares the image to known fillets and a cutting pattern is determined from that comparison. The product is in a relative still position during cutting to enable accurate cutting and a product such as a fish fillet is trimmed or portioned before skinning. Furthermore the cutting is performed without first removing the skin from the fillet enabling more precise positioning and location of pin bones. This gives possibilities for new and more valuable products, such as neck pieces with skin, than with conventional methods due to known position of the bones.
In a first aspect of the present invention a method is disclosed for processing food items such as chicken pieces or fish fillets. The method comprises the steps of:
bringing the food items to an under-cooled state, digital imaging of the food items selection of a cutting pattern from a plurality of cutting patterns, and cutting the food items in an under-cooled state with at least one water beam through a nozzle, where at least a part of bones or undesired tissue is removed.
In the present context the items are transported through the whole processing of the method on conveyors. Furthermore, the cutting is performed on the food items in an under-cooled state and the temperature of the food items is in the 0° C. to −1.5° C. temperature interval.
In an embodiment of the present invention, a three dimensional model is created and the information used for grading the items after processing based on characteristics such as shape, size and the weight of the food items. This information can be used later in the processing.
In an embodiment of the present invention, a fish fillet is being cut and the cutting pattern is determined so that a loin piece and/or the rest of the fillet is not skinned during the process.
According to the present invention the food items are cut before and/after skinning. The food items may be cut in a still position with at least one water beam through a cutting nozzle or in a relative still position between the cutting nozzle and the continuously moving food items. Furthermore, the cutting is performed with movable nozzles which can be tilted in a plane perpendicular to the movement of the food items or with movable nozzles which can be tilted in a plane perpendicular to the movement of the food items and where the tilt of the nozzle is adjusted to the variable angle of the pin bones in the food items.
In an embodiment of the present invention the first nozzle cuts one cutting track and the second nozzle cuts another track in the food items. The cut may exclude an area between the cutting tracks or it may exclude a marginal area close to the edge of the food items.
In an embodiment of the present invention the cutting is performed with a nozzle where the height of the nozzle can be adjusted according to the thickness of the food items. Furthermore, the cutting may involve trimming the food items.
In an embodiment of the present invention the skinning is performed on a fillet wherein the cut excludes a marginal area close to the edge of the fillet and the cut excludes an area between the cutting tracks. The skinning can also be performed with a device for skinning the fillet where the in-feed conveyor is lifted towards the cutting device for guiding a part of the fillet past the skinning knife.
In a second aspect of the present invention an apparatus is provided for processing food items such as chicken pieces or fish fillets, where the apparatus comprises the following:
means for bringing the food items to an under-cooled state, means for performing an imaging analysis of the food items, means for calculating cutting patterns based on the data from the imaging analysis of the food items, means for cutting or trimming the food items according to the method described above.
In the present context the items are transported through the whole processing of the method on conveyors. The apparatus may further comprise means for skinning the food items. In an embodiment of the present invention the skinning involves an in-feed conveyor being lifted towards the cutting device for guiding a part of the fillet past the skinning knife.
In an embodiment of the present invention the device comprises a skinning device. The skinning device comprises the following:
a conveyor belt a sensors, which registers the fillet arriving, a clamp, a drum, a knife, a clamp, which turns around an axis and supports the skin as the knife skins the fillet, and a drive mechanism, where the sensors are used for measuring the length of the fillet for precisely controlling the function of the skinning machine, where the signal from a sensor stops the conveyor if the previous fillet is still present in the machine, where the clamp turns around an axis for precise adjustment to the drum, and where the bracket supports the axis and the drum and the drive mechanism revolves the arrangement. The skinning device operates according to a method disclosed in the detailed description.
In an embodiment of the present invention a method and an apparatus are provided for processing fish or fish fillets with the aim of increase quality and efficiency of the processing and to remove at least part of the pin bones, wherein the method and the apparatus comprises the steps of:
Under-cooling of the fillet before processing Processing the fish fillet in an under-cooled state with or without skin Image analysis of the fish fillet with a digital imaging using at least two laser cameras and forming a three-dimensional model of the shape of the fish fillet using a computer software, Comparing the model of the fish fillet to known shapes of fillets, which have been pre-programmed in the software, Calculating the size and shape of fish pieces as compared to shape and volume of the pieces and to deliver this data into the computer system of the processing to collect information and for grading of products later on, Selecting a cutting pattern for each fish fillet according to the shape of the fish fillet being processed, Cutting the fish fillet with the skin attached using a water beam, wherein the cutting is performed with at least one water jet on a relative still fish fillet, and the cutting nozzle is tilted in the appropriate angle for allowing close cut to for example pin bones and the tilt is adjusted to the changing angle of the pin bones depending on the location of the pin bones in the fillet, Skinning the trimmed fillet, where the fillet is skinned in that the some parts of the fillet may have skin attached and other parts of the fillet are skinned as required in a skinning machine which skins the fillet in an gentle way without increasing gap and damage in the fillet
The method disclosed herein is based on under-cooling the food items, digital imaging of an item using at least two laser cameras and forming a three-dimensional model of the shape of the item using a computer software and an automatic removal of undesired tissue. The computer program controls the imaging of the item and makes a digital model of the item. The model is then compared to known shapes of items of the item type being processed, which are pre-programmed in the software and then the software calculates a desired cutting pattern for the removal of undesired tissue performed in another part of the device.
By making a three dimensional model of the items, the information can be used for grading based on shape, size and weight of the items and use this information later in the processing.
The computer software tracks the position of the items throughout the processing and sends the cutting pattern, selected and defined as mathematical vectors, to the cutting means in a similar manner as a computer sends a document for printing in a conventional computer. The apparatus knows the position of the item and the undesired tissue is removed by cutting and the item is portioned as desired by high pressure water beam.
In another aspect the present invention differs form prior art in that bone removal from a fish fillet is performed on a fish fillet in an under-cooled state. This allows for increased strength of the fillet, which protects the fillet against harsh treatment during processing. Furthermore, it is less difficult to locate the pin bones when the fillet is stiff providing better efficiency in bone removal than prior methods. By keeping the fillet in an under-cooled state causing stiffness, the fillet is straight and smooth and all the pin bones are in the right place, so that their position is known and cutting patterns may be calculated for the bone removal.
The fish fillet is cooled down with CBC technology. This technology involves cooling the fish fillet to the phase transition of freezing and process the fillet in an under-cooled state. When the fillet is in a under-cooled state it becomes stiffer than during conventional processing and the stiffness enables processing without the fillets loosing quality because of gapping in the flesh and further allows for removing the pin bones with more efficiency and accuracy than prior art methods.
In another aspect the present invention differs form prior art in that scanning and cutting of the fillet is performed on a fillet with the skin attached. This allows for more accurate positioning of the pin bones before bone removal and further to new possibilities of processing products with the skin attached. When the skin has not been removed, the fillet has not been subjected to the harsh treatment a traditional skinning process causes and often results in that the fillet becomes deformed and positioning of the pin bones becomes less accurate as well as the increasing the possibility of the bones becoming loose and moving around in the fillet.
When the fish fillet is being processed with the skin attached, the cutting patterns directing the cutting device are determined so that the cutting device leaves approximately 1 centimeter of the cut undone towards the edge of the fillet. This ensures that the fillet stays attached and is skinned in one piece. It is possible to process a fish fillet so that f. ex. the tail piece is skinned and the pin bones are removed simultaneously and f. ex. Loin pieces and/or flap are cut and processed with the skin attached. This function is achieved by the skinning unit which skins the fillet after cutting without handling the fillet in a harsh way. Therefore, the processing can deliver more valuable products than traditional methods as well as performing more efficiently due to increased weight of the pieces, as the skin is a part of the net weight of the product. The way to obtain this is to cut a portion, such as the loin piece, completely separated form the rest of the fillet. The rest of the fillet is skinned by a skinning device, but when the loin piece approaches the skinning device it is not skinned as it has been separated from the rest of the fillet and passes the skinning device without being skinned, as the knife of the skinning device is occupied skinning the rest of the fillet and is not able to receive new pieces for skinning meanwhile.
In another aspect the present invention differs form prior art in that the fillets are feed into a so called CBC cooler and two processing lines receive the fillets when they come out of the cooler in under-cooled state. A worker feeds the fillets alternatively onto each of the two independent processing lines and fillets are transported to scanning and cutting. After scanning, the fillet is transported to the water jet cutting unit. In the version of the arrangement described here the cutting is performed by using two cutting nozzles where each nozzle is used to cut one track in the fillet. The first nozzle cuts for example the longitudinal cut and is ready for the next fillet without using time to transport the nozzle to the return position. The second nozzle cuts the remaining track and needs less travel for cutting the next fillet.
With this embodiment, scanning and cutting devices have sufficient time to perform the cut providing a more accurate cut and the capacity is increased.
In another aspect the present invention differs form prior art in that scanning and cutting of the fillet is performed with nozzles which can be tilted an angle in a plane perpendicular to the direction of the fillet. This enables closer cut to the pin bones as the angle which the pin bones have according to the fillet varies and the tilting angle of the nozzle is adjusted to the changing angle of the pin bones.
It is possible to tilt the nozzles which produce the water beam, so that the rotate around the x-axis in a lengthwise direction of the fillet stream perpendicular to the z, y plan being athwart to the direction of the fillet stream. This provides a more accurate cutting adjacent to the pin bones and the removal of the pin bones. It is also possible to adjust the height of the nozzles in order to maintain a constant distance from the product irrespective of the thickness of the product. The water nozzles are driven by servo motors, which can control the movement of the water beam rapidly and accurately. It is also possible to have a plurality of cutting nozzles and imaging devices, so that each fillet channel uses one scanner and one cutting device, to eliminate the delay due to the movement of the scanner and the cutting device between the fillet channels thereby increasing the efficiency if desired.
The device of the present invention is implemented in a manner where the cutting devices are placed on a rack, which moves parallel to the conveyor belt so that the fillet is in a relative still position to the cutting device. In this way the movement of the fillet does not affect the quality of the product due to acceleration of the cutting device in starting and stopping the cutting nozzle providing a more efficient and accurate cutting. Furthermore, movements of the fillet are prevented due acceleration in starting and stopping as the fillet is being transported at a constant rate the whole time. The fillet is cut in a relative still position where the still position is defined as the position of the rack supporting the cutting device compared to the movement of the fish fillet on the conveyor belt.
The device can be implemented so that skinning is performed before the products are scanned and processed if required and the scanning and cutting method can further be used for trimming of fillets and other type of cutting without removing pin bones. The scanning and cutting method can also be used for trimming chicken breasts and other cutting of various products not mentioned here.
The arrangement includes a special designed skinning machine which eliminates the harsh and destructive treatment which occurs in traditional skinning machine. The design secures that the fillet does not bend or deform during skinning and the skinning machine also allows cutting the fillet before skinning. The equipment also makes it possible to process fillets where a part of the fillet remains with skin on during processing. The skinning device and the method of skinning are further disclosed below in the detailed description.
The surface or the conveyor belt, where the cutting is performed, is made from stainless steel net or any other material which can tolerate the strain of the water cutting.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention is described in detail below with reference to the following drawings, where each item is represented with the same number if the same number appears in more than one drawing, of which:
FIG. 1 . The figure shows an overview of the system of the present invention.
FIG. 2 . The figure illustrates scanning and water-jet cutting, for two independent streams of processing.
FIGS. 3 and 4 . The figures show scanning and water-let cutting illustrated in 3D and from side.
FIGS. 5-10 . The figures show the principle of the skinning machine unit
FIG. 11 . The figure shows the skinning machine unit illustrated in 3D
FIG. 12 . The figure shows a cut in a fish fillet where the pin bones are attached to the flap and the whole fillet is skinned.
FIG. 13 . The figure shows a cut in a fish fillet where the pin bones have been removed from the flap and the whole fillet is skinned.
FIG. 14 . The figure shows a cut in a fish fillet where the pin bones have been removed from the flap and the neck piece is cut in a way that the skin is attached to the neck piece after the fillet has been processed by the skinning device.
In the figures, a processing of fish fillets is shown, but the device and the method can apply to processing of any food items such as chicken part etc. The invention will be described in further detail, where specific parts of the invention will be referred to according to reference numbers in the drawings.
FIG. 1 illustrates an embodiment of a processing apparatus where scanning and an automatic device for bone removal and portioning of fillets. The fillets come from a CBC cooler 1 , where they are brought to an under-cooled state for further processing. The fillets are collected in a lane 2 from where the workers take them and place onto an in-feeding conveyors 3 , which feed the fillets to two independent processing lines.
The water cutting devices 5 and 6 are used for one track each in the same fillet for more capacity of the cutting device. The two fillet canals are independent of each other.
After scanning and cutting, the fillets move along to a skinning device 7 , where one skinning device is implemented for each fillet canal.
Skinning is performed in specially designed skinning device 7 . The principle of the skinning equipment is described in FIGS. 5-10 . The skinning device removes the skin from the fillet in an under-cooled and stiff state without bending or shaking it. This prevents further gapping and damaging of the fillet during the processing of skinning and sensitive filets go through skinning in the same manner as fillets with no gapping without being damaged.
The skinning devices can handle fillets, which have been pre trimmed and then had the pin bones removed from them and cut and portioned by the water cutting unit. On one hand the fillets are skinned so that all the skin is removed, but it is also possible to forgo the Loin piece in that it is moved to the side so that it passes the skinning slot and thereby the skin remains attached to the Loin piece but the tail piece is skinned as described below. Skin and waste is transported away from the skinning device on conveyor 10 . Portioning and final trimming is performed on processing line 8 .
The trimming mainly involves inspection and final trimming of portioned and bone removed fillets. The trimming takes place on a conveyor belt made from transparent and wear resistant material and lit up from below. The worker puts the Loin piece onto the one side of the belt, trims the tail piece and puts it on the other side of the belt and removes the flap which is packed individually. Waste, flaps and for ex. IQF portions are then disposed of onto lanes and over to conveyor belts 9 .
Packing and weighing of products is performed on packing station 11 . Both packing and weighing are performed by the same worker, which decreases excess handling of the products. There is a workstation 12 at the end of the out feeding conveyor belt 13 for the packing line for closing the packages and put ice in the packages if so desired.
The method disclosed herein can be implemented in several ways depending on what is desired.
Scanning and Calculation
A computer device is used for control of scanning and cutting, where the computer is connected to at least two laser cameras and a cutting device. A three dimensional model is created of the fillet and the computer device compares the model to known cutting patterns in the software of the computer. The size of the pieces is calculated based on these information and there from the cutting pattern. The software of the device contains information on the shape of a plurality of fillets and the position of the pin bones in these fillets as well as pre calculated cutting patterns which are compared to the image of the fillet being processed. The accurate position of the fillet is known and the cutting device is controlled by the computer and fillet is portioned into desired pieces and the pin bones are removed.
By making a three dimensional model of the fillet it is possible to use the information for grading with respect to shape, size and the weight of the fillets or the products and use the information for later processing. The scanning process is also used to define and chose the optimal cutting pattern according to the size and shape of the fillet.
Water Jet Cutting
The water cutting is performed in a fillet with the skin attached to it. The pin bones are removed and the fillet is then portioned as desired. A high pressure water beam is used for the water cutting such as a 2000-2500 bar pressure, which is guided through a cutting nozzle such as 0, 12 mm in diameter. The water cutting is performed by a high pressure nozzles attached to a sled which moves in a horizontal x, y plane and are controlled by servo motors. The water cutting is performed on a relative still fillet, which provides increased capacity, accuracy and more elegant cutting. By relative still fillet it means that the frame for the cutting nozzle is moved in the same direction and with the same speed as the fillet on the belt.
The arrangement described in FIG. 2 show the cutting performed by using two cutting nozzles 14 and 15 . The fillet 15 is transported to the conveyor belts on one of the cutting lanes 16 or 17 which are independent of each other. The scanner 18 scans the fillet and the information is used for the following cutting process. Each nozzle is used to cut one cutting track in the fillet. The first nozzle 14 cuts for example the longitudinal cutting track and is then ready for the next fillet without time is used to transport the nozzle to the return position. The second nozzle 15 cuts the remaining track and needs less travel for cutting the next fillet. Both cutting tracks in one fillet can also be performed by using a single nozzle. This will decrease the capacity compared to the method described here using one nozzle for each track. From the cutting the fillet is transported to the conveyor belt for further transport to the skinning machine 7 .
The cutting nozzles may be tilted compared to the x-length axis in the moving direction of the fillets so that a rotation around the x-axis is perpendicular to the z, y plan of the nozzles. This provides leaning the nozzles and cutting closer to the pin bones resulting in better efficiency of the pin bone removal. It is further possible to adjust the height of the nozzles in order to maintain a constant distance between the nozzle and the fillet independent of the thickness of the fillet.
The embodiment illustrated in FIGS. 3 and 4 show the scanning and water-jet cutting illustrated in 3D and from side. The fillet is placed on conveyor belt 21 which delivers to the cutting line 16 . A sensor 22 registers the fillet and controls the delivery from conveyor 21 to the scanning process. This controls the delivery to the scanning and cutting process allowing more altering in-feed to the cutting process. Sensor 23 registers the fillet arriving to the scanning and the signal is used for controlling the exact position of the fillet on the conveyor belt for the following processes.
Skinning
The function of the skinning machine 7 is illustrated in FIGS. 5 to 10 .
In FIG. 5 the fillet arrives on conveyor belt 25 . The sensor 26 registers the fillet arriving and the sensor 26 and sensor 27 are used for measuring the length of the fillet for precisely controlling the function of the skinning machine. The signal from sensor 26 stops the conveyor 25 if the previous fillet is still present in the machine.
In FIG. 6 the skinning is started. The tail tip of the fillet is placed in the grove 28 on drum 29 . The drum revolves clockwise and the clamp 31 supports the skin as the knife 30 skins the fillet. The fillet does not bend or twist during the skinning and due to the stiff condition in the under-cooled state the fillet is not damaged during the skinning process. The clamp 31 turns around axis 32 for precise adjustment to the drum 29 . The bracket 33 supports the axis 32 and the drum 29 and the drive mechanism 39 revolves the arrangement. The fillet is transported from skinning by conveyor 34 .
FIGS. 7 and 8 show the fillet going through the skinning process and the skin 35 is removed.
The embodiment illustrated in FIGS. 9 and 10 show the arrangement where the in-feed belt is lifted and moved towards the drum 29 as the fillet is skinned. This feature allows more precise control of the skinning process and is also necessary for controlling the bypass of portions which are not to be skinned. The whole arrangement for the in-feed belt 25 is moved in guides 36 and 37 . When the fillet is cut as shown in FIG. 14 and the loin portion 80 is fully cut apart from the rest of the fillet this movement of the in-feed belt ensures that the loin portion 80 bypasses the knife 30 and remains with the skin on while the rest of the fillet is skinned.
FIG. 11 shows the skinning machine 7 in 3 dimensional views. Mechanism 38 secures the strapping of the in-feed belt 25 . The sensor 40 registers when the skinned fillet has passed the skinning machine.
All methods disclosed herein above involve skinning part of the fillet or the whole fillet as desired. Therefore, the tail piece can be skinned while the loin piece has the skin attached or the whole fillet can be skinned.
FIG. 12 shows fillet where the whole fillet is skinned: This is performed by leaving c.a. one centimeter of each cut undone, when the fillet is cut. In this way the fillet is attached as it is skinned and the whole fillet is skinned by the skinning device, the fillet being in an under-cooled state and sufficiently solid due to the CBC technology. The fillet is then finally separated and examined on the post processing line.
FIG. 13 shows fillet where the Loin piece remains with the skin attached: This is performed by completing each cut, when the fillet is cut. The fillet is transported to the skinning device and the roller of the skinning device grip the tail piece, but the Loin piece with the skin attached is unattached to the rest of the fillet and is transported passed the roller and passed the skinning device. This provides a method to obtain a skinned tail piece and a Loin piece with the skin attached, where the pin bones have been automatically removed.
It is possible to tilt the cutting nozzles around the x-axis, perpendicular to the z, y plan (see FIG. 3 ) to obtain a more accurate cut closer to the pin bones and thereby obtain a better efficiency as compared to conventional methods. It is also possible to adjust the height of the nozzles in order to maintain a constant distance between the nozzle through the processing and the fillet to obtain increased accuracy and more elegant cutting. It is not necessary to cut the fillet with the skin attached and the device can be implemented so that skinning is performed before scanning and cutting.
It is also possible the use the method and the device of the present invention for trimming and cutting of whole fillets without removing pin bones as well as other type of processing.
FIGS. 12-14 show possible cutting patterns and products obtained by the present invention.
FIG. 12 illustrates an embodiment when the whole fillet is skinned. Fillet 41 is a fillet before cutting, wherein the cutting starts in point 42 and extends beyond the fillet to point 43 . After that the nozzle 14 , or the second nozzle 15 , is moved to point 44 and the fillet is cut in an arch to point 45 . This provides a cut passed area 46 , which is the cloacae-area of the fish and is frequently contaminated with bacteria. By using this cutting pattern the amount of bacteria in the product 53 is dramatically decreased. Fillet 47 is a product where all the skin is to be removed and areas 48 , 49 and 50 indicate areas on the fillet which are not cut and where the fillet is attached and can therefore be skinned in one piece. A worker on the processing line only needs to cut areas 48 , 49 and 50 to portion the fillet and then place the products onto appropriate lanes for further processing of each product. Filet piece 51 is a Loin piece, fillet piece 52 is a tail piece and fillet piece 53 is flap with the pin bones attached to it.
FIG. 13 illustrates an embodiment when the whole fillet is skinned and the pin bones are removed from the flap. Fillet 54 is a fillet before cutting, wherein the cutting starts in point 55 and extends beyond the fillet to point 56 . After that the nozzle 14 , or the second nozzle 15 , is moved to point 57 and the fillet is cut to appoint 58 beyond the pin bone area. Then the fillet is cut in an arch to point 59 as described above. In the same manner as described, for FIG. 12 the cut excludes the cloacae-area of the fish. Fillet 60 is a fillet where all the skin is to be removed and areas 61 - 64 indicate areas on the fillet which are not cut and where the fillet is attached and can therefore be skinned in one piece. A worker on the processing line only needs to cut areas 61 - 64 to portion the fillet as described above. Filet piece 66 is a Loin piece, fillet piece 65 is a tail piece, fillet piece 67 is flap and pin bones 68 are not attached.
FIG. 14 illustrates an embodiment when the a part of the fillet is skinned and the pin bones are removed from the flap, but the Loin piece is separated from the rest of the fillet and proceeds with the skin attached and passes the skinning device. Fillet 69 is a fillet before cutting, wherein the cutting with the first nozzle 14 starts in point 70 and continues by the track to point 71 . After that the second nozzle 15 starts in point 72 in a continuous cut in an arch to point 74 as described above. In the same manner as described for FIG. 6 , the cut excludes the cloacae-area of the fish. Fillet 75 is a fillet where the Loin piece has the skin attached and point 76 shows where the fillet is cut to separate it from the rest of the fillet. Areas 77 - 79 indicate areas on the fillet which are not cut and where the rest of the fillet is attached and can therefore be skinned in one piece. Filet piece 80 is a Loin piece with the skin attached, fillet piece 81 is a tail piece, fillet piece 82 is flap and pin bones 83 are not attached.
The cutting patterns may be different form the ones disclosed herein and the method of the present invention may be used to separate the whole flap from the rest of the fillet wherein the flap has the skin attached. It is possible to cut all cutting tracks in the fillet with one nozzle but this will reduce the capacity compared to use two nozzles where each is used for one track.
The device and the method of the present invention is not limited to the use for processing fish fillets, but may f. ex. be used to cut chicken pieces, such as chicken breasts and other food stuffs. The device is controlled with an industrial computer and sensors and servo motors regulate a correct movement and location on the device as well as having digital laser cameras and software to perform calculation and cutting according to predetermined cutting patterns. | The present invention relates to a method for automatically removing bones and trimming a product such as fish fillets, where the fillets are in an under cooled state. The under cooling makes the fillets sufficiently stiff to remove pin pones and portion a fillet before or after skinning the fillet in a relative still position providing better cutting than conventional methods. This provides more efficiency than prior art methods as well as increasing the value of the product due to less gaping and dehydration of the product. The method of the present invention further provides possibilities for grading of products processed with the three dimensional scanning and digital imaging of the products. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the foreign priority benefit under Title 35, United States Code, §119(a)-(d) of Japanese Patent Application No. 2005-264600, filed on Sep. 13, 2005 in the Japan Patent Office, the disclosure of which is herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a technology to reduce power consumption in a storage unit for storing mass data.
[0004] 2. Description of the Related art
[0005] In recent years, a great number of network connection functions are implemented in storage units. With the network connection functions, the storage unit can send and receive data and commands to and from computers through a fibre channel, IP (Internet Protocol) network, and so on. Storage units with iSCSI (Internet Small Computer System Interface), which is standardized as a protocol for sending and receiving SCSI (Small Computer System Interface) commands over TCP/IP (Transmission Control Protocol/Internet Protocol), are increasingly used.
[0006] In many cases in storage units connected to a network, a host (computer) does not access hard disks (referred as disk hereafter) of the storage units all the time, however, there is a problem that all the disks of the storage units are always rotating so as to be ready for being accessed by the host resulting in increase in power consumption and short lifetime of the disks because of mechanical exhaustion, or the like.
[0007] For example, a method for emulating an SCSI device in connecting a host and a storage unit through a network is disclosed in a Japanese Patent Publication JP 2005-78641A. However, concerning a disk drive which is one of SCSI devices, it mentions execution of only SCSI commands, and therefore the disks rotate all the time in a case where the SCSI device is a disk drive.
[0008] Accordingly, MAID (Massive Array of Idle Disks) technology has been developed to temporarily stop some or all of disks in a storage unit.
[0009] However, when a host accesses a stopped disk, it needs to rotate the disk again, causing a problem that it takes longer to access the disk compared with a case where disks rotate all the time. In other words, to stop rotating some or all of disks temporarily, it is required to appropriately determine the possibility of each of the disks to be accessed by the host.
[0010] Accordingly, it would be desirable to provide a storage unit in which appropriate timing to start/stop accessing each of disks is predicted so as to start and stop rotating the disk appropriately and selectively to reduce power consumption and prolong lifetime of the disk.
SUMMARY OF THE INVENTION
[0011] In one aspect of the present invention, there is provided a storage unit connected to a host computer through a network, having one or more disks in which read and write operations are performed during rotation and a control unit for controlling the rotation of the disks. In the storage unit, when receiving a message which is sent from the host computer and predicts that at least one of the disks will come in use, the control unit causes the at least one of the disks which will come in use, to rotate.
[0012] In another aspect of the present invention, there is provided a storage unit connected to a host computer through a network, having one or more disks in which read and write operations are performed during rotation and a control unit for controlling the rotation of the disks. In the storage unit, when receiving a message which is sent from the host computer and predicts that at least one of the disks will go out of use, the control unit causes the at least one of the disks which will go out of use, to stop.
[0013] In a further aspect of the present invention, there is provided a disk control method in a storage unit which is connected to a host computer through a network and has one or more disks in which read and write operations are performed during rotation and a control unit for controlling the rotation of the disks. In the disk control method, when receiving a message which is sent from the host computer and predicts that at least one of the disks will come in use, the control unit causes the at least one of the disks which will come in use, to rotate.
[0014] In another aspect of the present invention, there is provided a disk control method in a storage unit which is connected to a host computer through a network and has one or more disks in which read and write operations are performed during rotation and a control unit for controlling the rotation of the disks. In the disk control method, when receiving a message which is sent from the host computer and predicts that at least one of the disks will go out of use, the control unit causes the at least one of the disks which will go out of use, to stop.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a schematic view of a computer system according to the first embodiment.
[0016] FIG. 2 is a diagram showing programs and data stored in a memory in a storage unit.
[0017] FIG. 3 is a diagram showing an example of a target-portal table.
[0018] FIG. 4 is a diagram showing an example of a target-LU table.
[0019] FIG. 5 is a diagram showing an example of an LU-disk table.
[0020] FIG. 6 is a diagram showing an example of an initiator-LU table.
[0021] FIG. 7 is a diagram showing an example of an initiator status table.
[0022] FIG. 8 is a schematic diagram showing relationship among portals, targets, LUs, and disks.
[0023] FIG. 9 is a diagram showing process sequence in iSCSI login FIG. 10 is a diagram showing operation of a target program when an iSCSI login command is received.
[0024] FIG. 11 is a diagram showing operation of a disk start program.
[0025] FIG. 12 is a diagram showing process sequence in iSCSI logout.
[0026] FIG. 13 is a diagram showing operation of a target program when an iSCSI logout command is received.
[0027] FIG. 14 is a diagram showing operation of a disk stop program.
[0028] FIG. 15 is a diagram showing operation of a disk start program.
[0029] FIG. 16 is a diagram showing operation of a disk stop program.
[0030] FIG. 17 is a diagram showing process sequence in a discovery session.
[0031] FIG. 18 is a diagram showing process sequence when an SCN for notifying addition of initiator is received.
[0032] FIG. 19 is a diagram showing operation of a target program when an SCN for notifying addition of initiator is received.
[0033] FIG. 20 is a diagram showing process sequence when an SCN for notifying deletion of initiator is received.
[0034] FIG. 21 is a diagram showing operation of a target program when an SCN for notifying deletion of initiator is received.
[0035] FIG. 22 is a diagram showing process sequence when an iSNS database is updated (addition of initiator).
[0036] FIG. 23 is a diagram showing operation of a target program when a response for notifying addition of initiator is received.
[0037] FIG. 24 is a diagram showing process sequence when an iSNS database is updated (deletion of initiator).
[0038] FIG. 25 is a diagram showing operation of a target program when a response for notifying deletion of initiator is received.
[0039] FIG. 26 is a diagram showing operation of a target program when a message for notifying addition of initiator is received.
[0040] FIG. 27 is a diagram showing process sequence in a discovery session.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] A computer system S and a disk control method thereof according to exemplary embodiments of the present invention will be described below referring to the drawings.
[0000] First Embodiment
[0042] Operation when a storage unit receives an iSCSI login command from a host is described as an example of the first embodiment.
[0043] FIG. 1 is a schematic view of a computer system according to the present embodiment. As shown in FIG. 1 , the computer system S includes a storage unit 100 , a plurality of hosts 110 (host computers), an iSNS (Internet Storage Name Service) server 130 , and a virus check server 140 connected with each other through a network 120 such as Internet, and a management terminal 150 connected to the storage unit 100 .
[0044] The host 110 , which is an information processing unit for performing application programs which input and output data, has initiator programs 111 for accessing the storage unit 100 .
[0045] The storage unit 100 has a CPU (Central Processing Unit) 101 (control unit), a memory 102 (control unit), a cache 103 for accelerating access, a disk controller 104 , one or more disks 105 , a port 106 a and a port 106 b (also referred as ports 106 all together hereafter), a flash memory 107 , a management port 108 , and a bus 109 for connecting these units.
[0046] The CPU 101 executes programs stored in the memory 102 to perform various processes described below. The memory 102 is a unit for storing programs and data described below. The cache 103 is a unit for temporarily storing data to write. The disk controller 104 is a unit for controlling inputting and outputting data of the disks 105 . Here, the disk controller 104 may perform operations equivalent to RAID (Redundant Array of Independent Disks).
[0047] The disks 105 are units for storing data read and written by the host 110 . The ports 106 , which are units such as network cards for connecting a LAN (Local Area Network) cable to the storage unit 100 , send and receive data. Though the storage unit 100 has two ports 106 in the present embodiment, it may have three or more ports 106 .
[0048] The flash memory 107 is a unit for storing programs and data which are loaded to the memory 102 when the storage 100 starts up. The management port 108 is a unit for connecting the storage unit 100 to the management terminal 150 .
[0049] The iSNS server 130 manages information about initiators (units in the initiator program 111 in the host 110 , for triggering access to the disks 105 ) and targets (groups of data in the disks 105 of the storage unit 100 , accessed by the initiators, see FIG. 8 for details) connected to the network 120 , responds to inquiries about the information from the other units, and has a database 131 as a storage means for doing those.
[0050] Here, iSNS server 130 is not necessary in the present embodiment and used in other embodiments described later.
[0051] The virus check server 140 , which is a computer for detecting viruses which have entered the storage unit 100 , is not necessary in the present embodiment and used in other embodiments described later.
[0052] The management terminal 150 is a computer for setting information about the storage unit 100 , for example, setting a target-portal table 204 described later through a management port 108 in the storage unit 100 . The management terminal 150 includes a CPU 151 as a processing means, a memory 152 as a temporary storage means, a storage unit 153 as a storage means, an input unit 154 as an input means, an output unit 155 as an output means, a port 156 as a communication means, and a bus 157 as a means for connecting the units.
[0053] FIG. 2 shows the programs and the data stored in the memory 102 in the storage unit 100 (See FIG. 1 , as needed). A target program 201 , and a disk start program 202 , a disk stop program 203 , a target-portal table 204 , a target-LU (Logical Unit: a virtual disk consisting of one or more disks 105 ) table 205 , an LU-disk table 206 , an initiator-LU table 207 , an initiator status table 208 , and an initial program 209 are stored in the memory 102 .
[0054] The target program 201 is a program for sending and receiving iSCSI PDUs (Protocol Data Units) to and from the initiator program 111 running on the host 110 . Operation of the target program 201 , which calls the disk start program 202 and the disk stop program 203 respectively triggered by receiving an iSCSI login PDU and an iSCSI logout PDU, will be described in detail referring to FIG. 10 and FIG. 13 later.
[0055] The disk start program 202 is a program for starting rotating the disks 105 . Operation of the disk start program 202 , which is executed by being called by the target program 201 , will be described in detail referring to FIG. 11 later.
[0056] The disk stop program 203 is a program for stopping rotating the disks 105 . Operation of the disk stop program 203 , which is executed by being called by the target program 201 , will be described in detail referring to FIG. 14 later.
[0057] The target-portal table 204 , which is a table showing correspondence between targets and portals (pairs of IP addresses and TCP port numbers, described in detail referring to FIG. 8 later), will be described in detail referring to FIG. 3 later.
[0058] The target-LU table 205 , which is a table showing correspondence between targets and LUs, will be described in detail referring to FIG. 4 later.
[0059] The LU-disk table 206 , which is a table showing correspondence between LUs and disks, will be described in detail referring to FIG. 5 later.
[0060] The initiator-LU table 207 , which is a table showing correspondence between initiators and LUs assigned to the initiators, will be described in detail referring to FIG. 6 later.
[0061] The initiator status table 208 , which is a table showing initiator names and whether each of initiators is using disks or not at the point when the table is referred, will be described in detail referring to FIG. 7 later.
[0062] The initial program 209 is a program for initializing the initiator status table 208 shown in FIG. 7 such as when the storage unit 100 is powered on.
[0063] FIG. 3 shows an example of the target-portal table 204 (see FIG. 2 ). The target-portal table 204 is a table including sets of a target name 301 and portal identifiers 302 .
[0064] The target name 301 is a name for identifying an iSCSI target. The portal identifier 302 is a pair of an IP address and a TCP port number. The cell 303 indicates that a target identified by the target name “target 0 ” can be accessed through a portal identified by an IP address 192.168.0.1 and TCP port number 3260 or a portal identified by an IP address 192.168.0.2 and TCP port number 3260 .
[0065] FIG. 4 shows an example of the target-LU table 205 (see FIG. 2 ). The target-LU table 205 is a table including sets of a target name 401 and LUNs (Logical Unit Numbers) 402 .
[0066] The target name 401 is a name for identifying an iSCSI target similarly to the target name 301 . The LUN 402 is a number for identifying an LU. The cell 403 indicates that a target identified by a target name “target 0 ” processes input and output commands for LUs identified by LUNs “0” and “1”.
[0067] By the way, the target-LU table 205 is used by the storage unit 100 to acquire internal software relationship shown in FIG. 8 .
[0068] FIG. 5 shows an example of the LU-disk table 206 (see FIG. 2 ). The LU-disk table 206 is a table including sets of an LUN 501 and disk identifiers 502 .
[0069] The LUN 501 is a number for identifying an LU similarly to the LUN 402 . The disk identifier 502 is a text string for identifying the disk 105 (see FIG. 1 ). The cell 503 indicates that an LU identified by LUN “ 0 ” consists of disks identified by disk identifiers “0” and “1”.
[0070] FIG. 6 shows an example of the initiator-LU table 207 (see FIG. 2 ). The initiator-LU table 207 is a table including pairs of an initiator name 601 and an LUN 602 .
[0071] The initiator name 601 is a name for identifying an iSCSI initiator. LUN 602 is a number for identifying LU similarly to LUN 402 . The cell 603 indicates that an initiator identified by an initiator name “initiator0” can read and write data in an LU identified by an LUN “0”.
[0072] FIG. 7 shows an example of the initiator status table 208 (see FIG. 2 ). The initiator status table 208 is a table including pairs of an initiator name 701 and a use status 702 .
[0073] For example, FIG. 7 indicates that initiators identified by initiator names “initiator 0”, “initiator1”, and “initiator2” are using disks (the use statuses 702 are “1”) and an initiator identified by an initiator name “initiator 3” is not using disks (the use status 702 is “0”), at that point.
[0074] FIG. 8 is a schematic diagram showing internal software relationship among portals, targets, LUs, and disks in the storage unit 100 shown in the target-portal table 204 , the target-LU table 205 , the LU-disk table 206 , and the initiator-LU table 207 (see FIGS. 1-7 , as needed).
[0075] Portals 801 ( 801 a - 801 d ) are identified by pairs of an IP address and a TCP port number for accessing targets. Targets 802 ( 802 a and 802 b ), which are identified by target names, exchange iSCSI PDUs with initiators. Here, there may be a plurality of different targets in the storage unit 100 .
[0076] Meanwhile, LU 0 -LU 3 ( 803 a - 803 d ) are the LUs described above, and disk 0 -disk 7 ( 105 a - 105 h ) are similar to the disks 105 described above.
[0077] Next, operation of the computer system S is described. Here, an example in a case where only one initiator is assigned to an LU is described in the present embodiment (see FIG. 1 , and so on as needed).
[0078] Also, a case where an initiator knows a target name of a target from the first, that is, operation in a normal session is described in this and the second embodiments.
[0079] FIG. 9 is a diagram illustrating exchange of messages and data among the initiator program 111 , the target program 201 , and the disk start program 202 when the initiator program 111 sends an iSCSI login command to the target program 201 .
[0080] First, the initiator program 111 sends an iSCSI login command to the target program 201 (step 901 ).
[0081] Next, the target program 201 calls the disk start program 202 with an initiator name contained in the iSCSI login command, as a parameter (step 902 ), and thereby the disk start program 202 starts rotating the disks 105 ( 902 - 2 ).
[0082] In addition, the target program 201 sends a response for the iSCSI login to the initiator program 111 (step 903 ).
[0083] Thus, it is possible to start rotating the disks 105 when the iSCSI login command, which is a message predicting to start using the disks 105 , is sent from the initiator program 111 to the target program 201 .
[0084] FIG. 10 is a diagram showing operation of the target program 201 when the iSCSI login command is received (step 901 in FIG. 9 ). The CPU 101 executes the target program 201 stored in the memory 102 to process this operation.
[0085] First, the target program 201 receives an iSCSI login command from the initiator program 111 (Yes in step 1001 ) and reads an initiator name contained in the iSCSI login command (step 1002 ). And then, the target program 201 calls the disk start program 202 with the initiator name as a parameter (step 1003 ).
[0086] Next, the target program 201 sends a response for iSCSI login to the initiator program 111 (step 1004 ).
[0087] Thus, the target program 201 can start rotating the disks 105 when having received an iSCSI login command.
[0088] FIG. 11 is a diagram showing operation of the disk start program 202 . The CPU 101 executes the disk start program 202 stored in the memory 102 to perform this operation.
[0089] The disk start program 202 searches the initiator-LU table 207 (see FIG. 6 ) for the initiator name of the parameter (step 1101 ), and ends the process if there is not the initiator name of the parameter (No).
[0090] If there is the initiator name of the parameter in the initiator-LU table 207 (Yes in step 1101 ), an LUN ( 602 ) corresponding to the initiator name of the parameter is stored in a predetermined memory area in the memory 102 (step 1102 ).
[0091] Next, the disk start program 202 stores disk identifiers ( 502 ) in the LU-disk table 206 (see FIG. 5 ) corresponding to the LUN stored in step 1102 , in a predetermined memory area in the memory 102 (step 1103 ).
[0092] Moreover, the disk start program 202 starts rotating disks 105 identified by the disk identifiers stored in step 1103 (step 1104 ). For example, when an initiator name of a parameter is “initiator 0 ”, the disk start program 202 starts rotating disks identified by disk identifiers “0” and “1” (see FIG. 5 and FIG. 6 ).
[0093] Thus, the disk start program 202 can start appropriate disks 105 .
[0094] FIG. 12 is a diagram illustrating exchange of messages and data among the initiator program 111 , the target program 201 , and the disk stop program 203 when the initiator program 111 sends an iSCSI logout command to the target program 201 .
[0095] First, the initiator program 111 sends an iSCSI logout command to the target program 201 (step 1201 ).
[0096] Next, the target program 201 calls the disk stop program 203 with an initiator name contained in the iSCSI logout command as a parameter (step 1202 ), and thereby the disk stop program 203 stops rotating the disks 105 ( 1202 - 2 ).
[0097] In addition, the target program 201 sends a response for the iSCSI logout to the initiator program 111 (step 1203 ).
[0098] Thus, it is possible to stop rotating the disks 105 when the iSCSI logout command, which is a message predicting to stop using the disks 105 , is sent from the initiator program 111 to the target program 201 .
[0099] FIG. 13 is a diagram showing operation of the target program 201 when the iSCSI logout command is received (step 1201 in FIG. 12 ). The CPU 101 executes the target program 201 stored in the memory 102 to process this operation.
[0100] First, the target program 201 receives an iSCSI logout command from the initiator program 111 (Yes in step 1301 ) and reads an initiator name contained in the iSCSI logout command (step 1302 ).
[0101] Then, the target program 201 calls the disk stop program 203 with the initiator name as a parameter (step 1303 ). In addition, the target program 201 sends a response for iSCSI logout to the initiator program 111 (step 1304 ).
[0102] Thus, the target program 201 can stop rotating the disks 105 when having received an iSCSI logout command.
[0103] FIG. 14 is a diagram showing operation of the disk stop program 203 . The CPU 101 executes the disk stop program 203 stored in the memory 102 to process this operation.
[0104] The disk stop program 203 searches the initiator-LU table 207 for the initiator name of the parameter (step 1401 ), and ends the process if there is not the initiator name of the parameter (No).
[0105] If there is the initiator name of the parameter in the initiator-LU table 207 (Yes in step 1401 ), an LUN ( 602 ) corresponding to the initiator name of the parameter is stored in a predetermined memory area in the memory 102 (step 1402 ).
[0106] Next, the disk stop program 203 stores disk identifiers ( 502 ) in the LU-disk table 206 corresponding to the LUN stored in step 1402 , in a predetermined memory area in the memory 102 (step 1403 ).
[0107] Moreover, the disk stop program 203 writes data which have been submitted by an initiator identified by the initiator name of the parameter but not yet written to disks, to the disks 105 (step 1404 ). After the data have been written, the disk stop program 203 stops rotating disks 105 identified by the disk identifiers stored in step 1403 (step 1405 ). For example, when an initiator name of a parameter is “initiatory0”, the disk stop program 203 stops rotating disks 105 identified by disk identifiers “0” and “1” (see FIG. 5 and FIG. 6 ).
[0108] Thus, it is possible to stop rotating disks at the same time when an initiator stops using the disks such as when shutting down the host 110 , so as to reduce power consumption for rotating the disks and prolong lifetime of the disks.
[0000] Second Embodiment
[0109] It is assumed in the first embodiment that only one initiator is assigned to an LU. In the second embodiment, a case where a plurality of initiators are assigned to an LU is described.
[0110] Here, operation of the target program 201 when an iSCSI login command is received is similar to the operation in the first embodiment.
[0111] FIG. 15 is a diagram showing operation of the disk start program 202 (see FIG. 1 , and so on as needed). The CPU 101 executes the disk start program 202 stored in the memory 102 to process this operation.
[0112] The disk start program 202 searches the initiator-LU table 207 for the initiator name of the parameter (step 1501 ), and ends the process if there is not the initiator name of the parameter (No).
[0113] If there is the initiator name of the parameter in the initiator-LU table 207 (Yes in step 1501 ), an LUN ( 602 ) corresponding to the initiator name of the parameter is stored in a predetermined memory area in the memory 102 (step 1502 ).
[0114] Then, the disk start program 202 stores disk identifiers ( 502 ) in the LU-disk table 206 corresponding to the LUN stored in step 1502 , in a predetermined memory area in the memory 102 (step 1503 ). In addition, the disk start program 202 determines whether the number of initiators which are using a disk identified by each of the disk identifiers stored in step 1502 is 0 or not (step 1504 ). If the number is 0 (Yes), the disk start program 202 starts rotating the disk identified by the disk identifier stored in step 1503 (step 1505 ).
[0115] For example, when an initiator name of a parameter is “initiator0”, the disk start program 202 starts each of disks identified by disk identifiers “0” and “1” (see FIG. 5 and FIG. 6 ) if the number of initiators which are using the disk is 0.
[0116] Meanwhile, if the number of initiators which are using each of the disks assigned to the initiator identified by the initiator name of the parameter is greater than or equal to 1 (No in step 1504 ), it is not necessary to start rotating the disk any more since the disk is already rotating.
[0117] Finally, the disk start program 202 changes a use status in a row with the initiator name of the parameter to “1” in the initiator status table 208 (step 1506 ) and ends the process.
[0118] Thus, the disk start program 202 can appropriately start only stopped disks 105 of the disks 105 corresponding to the received iSCSI login command.
[0119] Here, operation of the target program 201 when an iSCSI logout command is received is similar to the operation in the first embodiment.
[0120] FIG. 16 is a diagram showing operation of the disk stop program 203 . The CPU 101 executes the disk stop program 203 stored in the memory 102 to process this operation.
[0121] The disk stop program 203 searches the initiator-LU table 207 for the initiator name of the parameter (step 1601 ), and ends the process if there is not the initiator name of the parameter (No).
[0122] If there is the initiator name of the parameter in the initiator-LU table 207 (Yes in step 1601 ), an LUN ( 602 ) corresponding to the initiator name of the parameter is stored in a predetermined memory area in the memory 102 (step 1602 ).
[0123] Then, the disk stop program 203 stores disk identifiers ( 502 ) in the LU-disk table 206 corresponding to the LUN stored in step 1602 , in a predetermined memory area in the memory 102 (step 1603 ).
[0124] Moreover, the disk stop program 203 searches the LU-disk table 206 and the initiator-LU table 207 to determine whether the number of initiators which are using each of the disks assigned to an initiator identified by the initiator name of the parameter is equal to 1, that is, whether the number of the initiators becomes 0 when decremented by 1. If the number is 1 (Yes in step 1604 ), the disk stop program 203 writes data which have been submitted by the initiator identified by the initiator name of the parameter but not yet written to disks, to the disks 105 (step 1605 ).
[0125] After the data have been written, the disk stop program 203 stops the disk 105 identified by the disk identifier stored in step 1603 (step 1606 ). For example, when an initiator name of a parameter is “initiator 0 ”, the disk stop program 203 stops each of disks 105 identified by disk identifiers “0” and “1” (see FIG. 5 and FIG. 6 ) if the number of initiators which are using the disk is 1.
[0126] Meanwhile, if the number of initiators which are using each of the disks assigned to the initiator identified by the initiator name of the parameter is greater than or equal to 2 (No in step 1604 ), the disk should not be stopped since the disk is still being used by the other initiators.
[0127] Finally, the disk stop program 203 changes a use status in a row with the initiator name of the parameter to “0” in the initiator status table 208 (step 1607 ) and ends the process.
[0128] Thus, it is possible to keep stopping rotation of each of the disks 105 while the number of initiators which are using the disk 105 is 0 even when a plurality of initiators are assigned to an LU.
[0000] Third Embodiment
[0129] In the first and the second embodiments, rotation of disks 105 is started triggered by receiving an iSCSI login for a normal session. In this embodiment, an example in a case where rotation of disks 105 is started triggered by receiving an iSCSI login for a discovery session is described. Here, the discovery session is a session in which an initiator specifies a target name using an IP address and a TC port number of a target.
[0130] FIG. 17 is a diagram illustrating exchange of messages and data among the initiator program 111 , the target program 201 , and the disk start program 202 when the initiator program 111 sends an iSCSI login command for a discovery session to the target program 201 (See FIG. 1 , and so on as needed).
[0131] First, the initiator program 111 sends an iSCSI login command for a discovery session to the target program 201 (step 1701 ).
[0132] The target program 201 calls the disk start program 202 with an initiator name contained in the iSCSI login command, as a parameter (step 1702 ), and thereby the disk start program 202 starts rotating the disks 105 ( 1702 - 2 ).
[0133] The initiator program 111 receives a response for the iSCSI login from the target program 201 (step 1703 ) and then sends an IP address and a TCP port number to the target program 201 by a Text Request command to inquire a target name (step 1704 ).
[0134] When the target program 201 receives the IP address and the TCP port number (step 1704 ), the target program 201 specifies a target name by searching the target-portal table 204 (see FIG. 3 ) and informs the target name to the initiator program 111 using a Text Response command (step l 705 ).
[0135] After that, the initiator program 111 sends an iSCSI logout command to the target program 201 (step 1706 ) and receives a response for the iSCSI logout from the target program 201 (step 1707 ), and then the discovery session ends.
[0136] Here, operation of the target program 201 when an iSCSI login command is received is similar to the operation in the first embodiment excepting that the iSCSI login is for a discovery session.
[0137] Additionally, operation in step 1702 - 2 in the disk start program 202 is similar to the operation in the first embodiment when only one initiator is assigned to an LU and the operation in the second embodiment when a plurality of initiators are assigned to an LU.
[0138] Though the target program 201 calls the disk start program 202 triggered by receiving an iSCSI login command for a discovery session in the present embodiment, the disk start program 202 may be called triggered by receiving a Text Request command or an iSCSI logout command for a discovery session instead.
[0139] Here, operation of the target program 201 when an iSCSI logout command for a normal session is received is similar to the operation in the first or the second embodiment.
[0140] Thus, the target program 201 can also start rotating disks 105 appropriately even in a discovery session.
[0000] Fourth Embodiment
[0141] In the embodiments described above, rotation of disks is started or stopped triggered by receiving an iSCSI command. In the fourth embodiment, rotation of disks is started or stopped triggered by receiving an iSNS message (see FIG. 1 , and so on as needed).
[0142] FIG. 18 is a diagram illustrating exchange of messages and data among the initiator program 111 , the iSNS server 130 , the target program 201 , and the disk start program 202 when the initiator program 111 registers attribute to the iSNS server 130 .
[0143] First, the initiator program 111 performs attribute registration to the iSNS server 130 (step 1801 ). Attribute registration is, for example, to register an initiator name and an IP address of an initiator to be added.
[0144] In response to this, the iSNS server 130 returns a response for the initiator program 111 (step 1802 ), and updates contents of the database 131 (step 1803 ). Then, the iSNS server 130 notifies addition of initiator to the target program 201 by an SCN (Specification Change Notice) (step 1804 ).
[0145] The target program 201 calls the disk start program 202 with an initiator name as a parameter (step 1805 ), and thereby the disk start program 202 starts rotating the disks 105 ( 1806 ).
[0146] Thus the target program 201 can start rotating disks 105 triggered by receiving an SCN (message) for notifying addition of initiator.
[0147] FIG. 19 is a diagram showing operation of the target program 201 when an SCN for notifying addition of initiator is received from the iSNS server 130 (step 1804 in FIG. 18 ). The CPU 101 executes the target program 201 stored in the memory 102 to process this operation.
[0148] First, the target program 201 judges whether it has received an SCN for notifying addition of initiator or not (step 1901 ), and reads an initiator name contained in the SCN (step 1902 ) when having received the SCN (Yes). And then, the target program 201 calls the disk start program 202 with the initiator name as a parameter (step 1903 ).
[0149] Operation of the disk start program 202 is similar to the operation in the first embodiment when only one initiator is assigned to an LU and the operation in the second embodiment when a plurality of initiators are assigned to an LU.
[0150] Thus, the target program 201 can start appropriate disks 105 when having received an SCN for notifying addition of initiator.
[0151] FIG. 20 is a diagram illustrating exchange of messages and data among the initiator program 111 , the iSNS server 130 , the target program 201 , and the disk stop program 203 when the iSNS server 130 deletes an initiator by updating the database 131 .
[0152] First, the iSNS server 130 updates contents of the database 131 , that is, deletes an initiator triggered by being requested from the initiator program 111 (such as attribute registration) or passing expiration time of an initiator stored in the database 131 (step 2001 ).
[0153] Then, the iSNS server 130 notifies deletion of initiator to the target program 201 by an SCN (step 2002 ).
[0154] Moreover, the target program 201 calls the disk stop program 203 with an initiator name as a parameter (step 2003 ), and thereby the disk stop program 203 stops rotating the disks 105 ( 2004 ).
[0155] Thus the target program 201 can stop rotating disks 105 triggered by receiving an SCN (message) for notifying deletion of initiator.
[0156] FIG. 21 is a diagram showing operation of the target program 201 when an SCN for notifying deletion of initiator is received from the iSNS server 130 (step 2002 in FIG. 20 ). The CPU 101 executes the target program 201 stored in the memory 102 to process this operation.
[0157] The target program 201 judges whether it has received an SCN for notifying deletion of initiator or not (step 2101 ), and reads an initiator name contained in the SCN (step 2102 ) when having received the SCN (Yes). And then, the target program 201 calls the disk stop program 203 with the initiator name as a parameter (step 2103 ).
[0158] Operation of the disk stop program 203 is similar to the operation in the first embodiment when only one initiator is assigned to an LU and the operation in the second embodiment when a plurality of initiators are assigned to an LU.
[0159] Thus, the target program 201 can stop appropriate disks 105 when an SCN for notifying deletion of initiator is received.
[0000] Fifth Embodiment
[0160] In the fifth embodiment, an example in a case where the storage unit 100 inquires information about initiators to the iSNS server 130 to start and stop rotating disks based on the results (see FIG. 1 , and so on as needed) is described.
[0161] FIG. 22 is a diagram illustrating exchange of messages and data among the iSNS server 130 , the target program 201 , and the disk start program 202 when the target program 201 inquires information about initiators to the iSNS server 130 and an initiator is added in the iSNS server 130 .
[0162] The target program 201 inquires to the iSNS server 130 periodically (step 2201 ), and the iSNS server 130 returns a response for it to the target program 201 (step 2202 ).
[0163] Here, it is assumed that the iSNS server 130 updates contents of the database 131 (addition of initiator) at a timing triggered by attribute registration from the initiator program 111 , or the like (step 2203 ).
[0164] The target program 201 inquires to the iSNS server 130 (step 2204 ), the iSNS server 130 returns a response for notifying addition of initiator to the target program 201 (step 2205 ).
[0165] When having received the response, the target program 201 calls the disk start program 202 with the initiator name as a parameter (step 2206 ), and thereby the disk start program 202 starts rotating the disks 105 (step 2207 ).
[0166] Thus, the target program 201 can start rotating disks 105 triggered by a response (message) for notifying addition of initiator.
[0167] FIG. 23 is a diagram showing operation of the target program 201 when inquiring to the iSNS server 130 and receiving a response for notifying addition of initiator (step 2205 in FIG. 22 ). The CPU 101 executes the target program 201 stored in the memory 102 to process this operation.
[0168] First, the target program 201 judges whether it has received a response for notifying addition of initiator from the iSNS server 130 or not (step 2301 ), and reads an initiator name contained in the response (step 2302 ) when having received the response (Yes). And then, the target program 201 calls the disk start program 202 with the initiator name as a parameter (step 2303 ).
[0169] Operation of the disk start program 202 is similar to the operation in the first embodiment when only one initiator is assigned to an LU and the operation in the second embodiment when a plurality of initiators are assigned to an LU.
[0170] Thus, the target program 201 can start appropriate disks 105 .
[0171] FIG. 24 is a diagram illustrating exchange of messages and data among the iSNS server 130 , the target program 201 , and the disk stop program 203 when the target program 201 inquires information about initiators to the iSNS server 130 and an initiator is deleted in the iSNS server 130 .
[0172] The target program 201 inquires to the iSNS server 130 periodically (step 2401 ), and the iSNS server 130 returns a response for it to the target program 201 (step 2402 ).
[0173] Here, it is assumed that the iSNS server 130 updates contents of the database 131 (deletion of initiator) at a timing triggered by attribute registration from the initiator program 111 , passing expiration time of an initiator, or the like (step 2403 ).
[0174] The target program 201 inquires to the iSNS server 130 (step 2404 ), the iSNS server 130 returns a response for notifying deletion of initiator to the target program 201 (step 2405 ).
[0175] When having received the response, the target program 201 calls the disk stop program 203 with the initiator name as a parameter (step 2406 ), and thereby the disk stop program 203 stops rotating the disks 105 (step 2407 ).
[0176] Thus, the target program 201 can stop rotating disks 105 triggered by a response (message) for notifying deletion of initiator.
[0177] FIG. 25 is a diagram showing operation of the target program 201 when inquiring to the iSNS server 130 and then receiving a response for notifying deletion of initiator (step 2405 in FIG. 24 ). The CPU 101 executes the target program 201 stored in the memory 102 to process this operation.
[0178] First, the target program 201 judges whether it has received a response for notifying deletion of initiator from the iSNS server 130 or not (step 2501 ), and reads an initiator name contained in the response (step 2502 ) when having received the response (Yes). And then, the target program 201 calls the disk stop program 203 with the initiator name as a parameter (step 2503 ).
[0179] Operation of the disk stop program 203 is similar to the operation in the first embodiment when only one initiator is assigned to an LU and the operation in the second embodiment when a plurality of initiators are assigned to an LU.
[0180] Thus, the target program 201 can stop appropriate disks 105 .
[0000] Sixth Embodiment
[0181] In the sixth embodiment, it is assumed that the storage unit 100 starts rotating the disks 105 triggered by occurrence of any of events possible to trigger to start rotating disks described in from the first to the fifth embodiments. In addition, it is also assumed that the storage unit 100 stops rotating the disks 105 triggered by occurrence of any of events possible to trigger to stop rotating disks described in from the first to the fifth embodiments.
[0182] FIG. 26 is a diagram showing operation of the target program 201 when an event possible to trigger to start rotating disks is received. The CPU 101 executes the target program 201 stored in the memory 102 to process this operation.
[0183] When receiving one of an iSCSI login command from the initiator program 111 (Yes in step 2601 ), an SCN for notifying addition of initiator from the iSNS server 130 (Yes in step 2602 ), or a response for notifying addition of initiator from the iSNS server 130 (Yes in step 2603 ) as one of messages for notifying events possible to trigger to start rotating disks, the target program 201 reads an initiator name contained in the message (step 2604 ). And then, the target program 201 calls the disk start program 202 with the initiator name as a parameter (step 2605 ).
[0184] Operation of the disk start program 202 is similar to the operation in the first embodiment when only one initiator is assigned to an LU and the operation in the second embodiment when a plurality of initiators are assigned to an LU.
[0185] Thus, the target program 201 can start rotating disks 105 based on any of events possible to trigger to start rotating disks 105 . The target program 201 can also operate similarly to stop rotating the disks 105 .
[0000] Seventh Embodiment
[0186] In each of the embodiments described above, an event such as that a user of the host 110 powers on the host 110 to start using the disks 105 or that a user of the host 110 powers off the host 110 to stop using the disks 105 triggers to start or stop rotating the disks 105 . However, it is possible to use software, which is running on a computer and plays a similar role as an initiator, in the virus check server 140 which is powered on all the time, to start and stop using disks automatically.
[0000] Eighth Embodiment
[0187] In the present embodiment, in a discovery session, a target name is informed to an initiator not when the disks 105 to be used by the initiator are just started, but when the disks 105 become ready to use (see FIG. 1 , and so on as needed).
[0188] FIG. 27 is a diagram illustrating exchange of messages and data among the initiator program 111 , the target program 201 , and the disk start program 202 when the initiator program 111 sends an iSCSI login command for a discovery session to the target program 201 .
[0189] The initiator program 111 sends an iSCSI login command for a discovery session to the target program 201 (step 2701 ).
[0190] Having received the iSCSI login command for the discovery session, the target program 201 executes the disk start program 202 . Here, the target program 201 reads an initiator name contained in the iSCSI login command and calls the disk start program 202 with the initiator name as a parameter (step 1702 ).
[0191] Then, the target program 201 sends a response for the iSCSI login to the initiator program 111 (step 2703 ).
[0192] When having received the response, the initiator program 111 sends a Text Request command to inquire a target name to the target program 201 (step 2704 ).
[0193] Meanwhile, when the disk start program 202 has started rotating disks 105 (step 2708 ) and then the disks 105 become ready (to use) (Yes in step 2709 ), the disk start program 202 sends a response for the target program 201 (step 2710 ).
[0194] After step 2704 , the target program 201 receives the response from the disk start program 202 (step 2710 ) and then returns a Text Response to the initiator program 111 (step 2705 ).
[0195] After that, the initiator program 111 sends an iSCSI logout command to the target program 201 (step 2706 ) and receives a response for the iSCSI logout from the target program 201 (step 2707 ), and then the discovery session ends.
[0196] Operation of the disk start program 202 is similar to the operation in the first embodiment when only one initiator is assigned to an LU and the operation in the second embodiment when a plurality of initiators are assigned to an LU.
[0197] According to the present embodiment, it is possible to prevent an initiator from issuing a read request to disks 105 which have not yet become ready to use.
[0198] As described above, according to the storage unit 100 in the computer system S in each of the present embodiments, it is possible to start rotating the disks 105 appropriately by predicting that the host 110 starts accessing the disks 105 triggered by an event such as an iSCSI login (for a normal or a discovery session) or a notice of addition of initiator from the iSNS server 130 . In addition, it is also possible to stop rotating the disks 105 appropriately by predicting that the host 110 stops accessing the disks 105 triggered by an event such as an iSCSI logout or a notice of deletion of initiator from the iSNS server 130 . Accordingly, it is possible to cut down power consumption of the disks 105 and reduce mechanical strain to prolong lifetime of the disks 105 .
[0199] Moreover, when a diskless PC or a server such as a virus check server which scans disks accesses the storage unit 100 , it is similarly possible to predict to start/stop accessing the disks 105 to start/stop rotating the disks 105 , resulting to reduce power consumption and prolong lifetime of the disks 105 According to the present invention, it is possible to reduce power consumption and prolong lifetime of disks in a storage unit.
[0200] Though the embodiments of the present invention have been described, it is to be understood that the invention is not limited to the embodiments. For example, the invention can be applied similarly when a search engine, or the like, scans disks. The other changes can be made in practical structures of hardware, flow charts, and so on as needed without departing from the spirit and scope of the invention | A storage unit is provided which is connected to a host computer through a network, having one or more disks in which read and write operations are performed during rotation and a control unit for controlling the rotation of the disks. In the storage unit, when receiving a message which is sent from the host computer and predicts that at least one of the disks will come in use, the control unit causes the at least one of the disks which will come in use, to rotate. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to dynamic testing of ground support bolts such as anchor/rock bolts.
BACKGROUND TO THE INVENTION
[0002] Rock bolts are long anchor bolts used to stabilise excavations in rock, such as tunnels and rock faces. A rock bolt transfers load at the exterior surface of the rock into the interior mass of the rock. Anchor bolts are used to securely attach objects to rock or concrete surfaces.
[0003] The 1890s first saw the use of rock bolts. The St Joseph Lead Mine in the USA in the 1920s is recorded as having used rock bolts.
[0004] Australia and the USA have both been recorded as using rock bolts in civil applications in the late 1940s. In 1947 Australian engineers were reported as experimenting with four metre long expanding anchor rock bolts during work on the Snowy Mountain scheme.
[0005] Rock bolts are typically installed in a pattern, the actual arrangement depending on the type of rock (rock quality—position and type of fractures already present, strength of the rock and its propensity to fracture etc.), the type of excavation (tunnel, cut face etc.) and the surrounding geology/geography (risk of seismic activity and any nearby underground or overground workings/structures).
[0006] Both rock bolts and anchor bolts can be used to retain a metal (wire) mesh over a rock face to reduce risk of loose material or rock fall that might injure personnel, damage vehicles/equipment and/or block a tunnel.
[0007] As with anchor bolts, there are many types of proprietary rock bolt designs. Typically a mechanical means, epoxy means or combination of both is used to set the bolt into the rock/concrete.
[0008] Rock bolts work by ‘knitting’ the rock mass together sufficiently before it can move enough to loosen and fail. Rock bolts can become ‘seized’ throughout their length by small shears in the rock mass, so they are not fully dependent on their pull-out strength.
[0009] In the case of a rock bolt, it is important to ensure that the rock bolt is capable of retaining the rock in situ when installed. In the case of an anchor bolt, it is important to ensure the item secured by the bolt is safely retained.
[0010] Static testing is an alternative form of test. This can be carried out in a laboratory or in situ. A continuous load is applied to the rock bolt, usually hydraulically. However, static testing does not simulate the ‘shock’ loading to the bolt present in dynamic testing.
[0011] Dynamic tests are conducted to ensure the respective bolt can operate as required. For rock bolts, a dynamic test is carried out in laboratory using a simulated bore-hole whereby the rock bolt is secured in a cement/resin mix inserted into a hollow (steel) tube. The tube is supported as a load acts on the head of the rock bot. This involves hydraulically applying a pull out force to the rock bolt.
[0012] Whilst laboratory simulation is useful, it does not accurately recreate working conditions and cannot perform an in-situ dynamic test on a bolt for the actual rock. Laboratory dynamic testing involves setting the rock bolt in the tube and suspending the tube and rock bolt from a raised support. A weight is dropped a preset distance to apply a shock load to the head of the bolt. The amount of weight and distance dropped determines the amount of force applied to the rock bolt.
[0013] Another form of laboratory testing involves dropping the rock bolt and tube combination together with a weight attached to the rock bolt. Fall of the rock bolt and tube is arrested once the required velocity is reached, but the weight is allowed to continue and thereby applies a load to the rock bolt. This method is said to better simulate the movement of the rock before the rock face fails (i.e. during a seismic event). Such testing is carried out by the Western Australian School of Mines (WASM) and is known as the WASM momentum transfer concept.
[0014] With the aforementioned in mind, the resent invention has been developed in order to provide improved in situ dynamic testing for rock bolts (and optionally anchor bolts).
SUMMARY OF THE INVENTION
[0015] The present invention provides in one aspect a connector to attach a loading device to an in situ ground support bolt, such as a rock bolt or anchor bolt in a rock or concrete substrate, the connector including a body, a first attachment means to attach the body to an in situ rock bolt or anchor bolt, and a loading device connection.
[0016] The loading device connection may include a second attachment means to releasably attach the loading device to the body.
[0017] The body may be unitary or may include multiple portions. For example, the body may be divided into portions that are releasably connectable together by one or more integral or detachable fastening means.
[0018] The connector may include at least one first curved surface on a cavity within the body, and a corresponding second curved face associated with the first attachment means. The first and second curved faces permit relative movement of the first attachment means and the body.
[0019] The connector may include a third curved surface, which may be within the first cavity or may be within a second cavity of the body. A fourth curved surface may contact the third curved surface to allow relative movement of the loading device and the body.
[0020] The cooperating first and second curved surfaces may be complimentary part spherical surfaces, such that movement of one surface relative to the other is multi directional. Likewise, the cooperating third and fourth surfaces may be part spherical surfaces, such that movement of the third surface relative to the fourth surface is multi dimensional. The part spherical surfaces allow for the rock bolt not being vertical in situ. Often rock bolts are angled from vertical into the rock. Relative movement of the first attachment means to the body, and the body to the loading device, allows the connector to transfer impact forces from a vertically dropped weight into the non-vertical rock bolt.
[0021] The first attachment means may include rock bolt connection means to attach the connector to the rock bolt. The rock bolt connection means may include an aperture to receive a shaft portion of the rock bolt. A nut on the external exposed end of the rock bolt may be used to retain the first attachment means to the rock bolt. Preferably the attachment via the nut of the rock bolt transfers the test load forces to the rock bolt.
[0022] Preferably the body has two or more portions arranged to be releasably held together by one or more fasteners. Release of the one or more fasteners allows the body to separate such that at least one of said portions can be removed.
[0023] The body may include two halves that are held together, in use, by the one or more fasteners. The one or more fasteners may include screw thread fasteners (such as bolts) directly into/through the body portions. Alternatively, or in addition, one or more retaining plates may be used. A said retaining plate may include a metal ring with holes therethrough to receive bolts. Bolts may be passed through aligned holes on each ring and nuts attached to the bolts to retain the two halves tightly together once the nuts and bolts are tightened.
[0024] The portions of the body may include flanges or lips, each flange or lip acting as a stop for one of the plates. Thus, when the bolts and nuts are tightened, the rings apply forces to the flanges/lips to hold the two halves together.
[0025] One or more forms of the present invention includes means to prevent damage to an electrical connector of a load cell provided within the connector. Such protection may include at least one metal projection adjacent the electrical connector. For example, a pin or bolt projecting above the load cell electrical connector and a tab of a washer projecting below the load cell electrical connector.
[0026] A further aspect of the present invention provides a dynamic testing system for testing rock bolts and anchor bolts in situ, the system including a loading device and a connector to releasably attach the loading device to an in situ rock bolt or anchor bolt, the loading device including at least one releasable weight to apply an impact load through the connector to the rock bolt or anchor bolt when released, and a weight release device, the connector including at least two portions releasably connectable together.
[0027] The system may include the abovementioned connector and features thereof.
[0028] A method of testing a rock bolt or anchor bolt in situ, the method including connecting a connector to an exposed portion of the rock or anchor bolt, attaching a weight drop assembly to the connector, providing a weight release mechanism to remotely release the weights during testing, the connector including at least one curved surface allowing the weight drop assembly to hang at or near vertical if the rock bolt or anchor bolt in situ is not vertical.
[0029] One or more forms of the present invention advantageously provides for in-situ dynamic testing of ground support members (such as rock bolts) with the ability to record load and displacement of the ground support member (e.g. rock bolt). There are no assumptions required with the rig or the testing, as the rock bolts are already installed in site rock and loaded under test as required.
[0030] Some features and benefits of the system include:
[0031] The test system (Dynamic Testing Rig) can be readily transported to any mine site. No requirement for testing to be restricted to an offsite test facility.
[0032] The test system (rig) is fully self contained (preferably only requires access to mine supply air to run the lifting hoist, though bottled compressed air/nitrogen can be brought in).
[0033] Requires only one person, such as an IT (Integrated tool-handler), to assemble and disassemble the test system.
[0034] Static test on bolt prior to dynamic test (optional if required).
[0035] Energy application levels are readily adjustable. For example, in increments of 8.2 kJ (with optional minor ‘fine tuning’ adjustments of 1.8 kJ).
[0036] Can be used to test any dynamic bolt in-situ. Custom dynamic collars (connector halves) may be provided.
[0037] Repeated loading on single bolts possible.
[0038] Allows free displacement until drop rig impacts with floor (not typically experienced).
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Embodiments of the present invention will hereinafter be described with reference to the accompanying drawings, in which:
[0040] FIGS. 1 to 3 show an example of a connector and test system utilising the connector according to an embodiment of the present invention.
[0041] FIG. 4 shows a cross section in perspective of an alternative embodiment of the connector.
[0042] FIGS. 5 and 6 show perspective ( FIG. 5 ) and side sectional view ( FIG. 6 ) of a test system according to an embodiment of the present invention.
[0043] FIG. 7 shows a nut threaded onto an exposed end of a rebar ground support bolt to apply an adapter or the first attachment means to the bolt to then receive the connector according to an embodiment of the present invention.
[0044] FIG. 8 shows an adapter threaded onto an external thread on a nut of a ground support bolt (such as a rock bolt) to retain a connector on the bolt according to an embodiment of the present invention.
[0045] FIGS. 9 and 10 show side on external views of the connector forming part of a dynamic testing rig/assembly according to an embodiment of the present invention.
[0046] FIG. 11 shows in perspective view the connector of FIGS. 9 and 10 .
[0047] FIG. 12 shows a cutaway view of the connector of FIGS. 9-11 and showing the internal arrangement of components.
[0048] FIG. 13 shows a sectional view through the embodiment shown in FIGS. 9 to 12 .
[0049] FIGS. 14 a and 14 b show respective side partial cutaway ( FIG. 14 a ) and perspective partial cutaway ( FIG. 14 b ) of an upper portion of the dynamic testing system including the connector and as attached to a non-vertical ground support bolt in-situ in a mine roof.
[0050] FIGS. 15 and 16 show perspective and side sectional views of the dynamic testing assembly/rig with suspended weights according to an embodiment of the present invention.
[0051] FIG. 17 shows a chart of energy displacement performance from in-situ tests conducted at two mine sites.
DESCRIPTION OF PREFERRED EMBODIMENT
[0052] FIGS. 1 to 3 show an embodiment of a dynamic test system for rock bolts. It will be appreciated that the same system can be used to test anchor bolts in rock and concrete by selecting the amount of weight and drop height for the type of anchor bolt (or rock bolt) for a given application.
[0053] As shown in FIG. 1 , a rock bolt 10 is set vertically in an overhead mass of rock 12 (such as a roof of a tunnel). A connector 14 connects the head end of the rock bolt to a shaft 16 . A weight 18 is mounted for movement along the shaft when released by a quick release mechanism 20 . The weight comprises a container 22 to hold multiple individual weights 24 . The amount of individual weights in the container controls the total weight of the container and weights for a required test.
[0054] It will be appreciated that alternative weights can be used. For example, flat plate weights slotted onto the shaft rather than loose weights in a container. A stop member 26 prevents the container/weights coming off the end 30 of the shaft. A threaded nut may be provided to act as or retain the stop member.
[0055] The connector 14 is vertically divided into two halves 14 a, 14 b. (see FIGS. 2 and 3 for detail). Which clasp around the head end of the rock bolt and the upper end of the shaft.
[0056] As shown in FIG. 2 , a first attachment means 32 retains the nut 36 and washer 38 at the head end of the rock bolt. The first attachment means has a curved surface 40 that contacts a corresponding curved surface 42 formed on the inside faces of the two halves of the connector. The mutually curved contact surfaces 40 , 42 allow the connector several angular degrees of movement about the rock bolt head. This positional ability accommodates the test system acting on a non-vertical rock bolt. A tapered opening 44 with tapered surface on the connector allows for the movement of the connector relative to the shaft/head of the rock bolt and acts as a stop limit.
[0057] The lower end of the connector 48 accommodates a second attachment means 50 that has an aperture therethrough to receive the upper end of the shaft (not shown in FIG. 2 ). A nut retains the upper end of the shaft in a similar way to the head of the rock bolt against the first attachment means. The second attachment means can attach by screw thread onto the upper end of the shaft.
[0058] The second attachment means includes a curved surface 54 and the two halves of the connector form a mutually curved interior surface 56 that contacts the curved surface of the second attachment means to allow angular degrees of freedom of movement of the second attachment means, and therefore the shaft and weights, relative to the connector (and therefore relative to the rock bolt). This arrangement allows the test rig to act on the in situ rock bolt even if the rock bolt is not vertical.
[0059] The connector 14 shown in FIGS. 1 to 3 has multiple holes 60 through paired flanges 62 a, 62 b and 64 a, 64 b. Bolts through the holes in the flanges are used to hold the two halves together in situ.
[0060] The alternative embodiment of a connector 100 of the present invention shown in FIG. 4 operates in a similar manner to the connector shown in FIGS. 1 to 3 . The connector 100 includes two vertically separated portions 100 a, 100 b. Each portion includes at least one handle 102 to assist with lifting and holding each portion when mounting to the rock bolt.
[0061] It will be appreciated that the head nut of the rock bolt may or may not be loosened or removed so that the first attachment means can be mounted to the head of the rock bolt after installation of the rock bolt. Alternatively, during installation of the rock bolt, the first attachment means or an adapter or spacer for connection of the connector can be attached to the rock bolt so that the head nut of the rock bolt is not removed to connect the connector.
[0062] The end of the rock bolt exposed out of the rock passes through the aperture 114 in the first attachment means. The two halves 100 a, 100 b of the connector 100 are then placed about the first attachment means with the second attachment means 116 suspending the shaft 118 via a shaft adapter 120 and nut 122 .
[0063] Alternatively, an adapter or the first attachment means can be retain on an exposed end of a ground support bolt (such as a rock bolt) by a nut threaded onto the shaft of the bolt. As shown in FIG. 7 , a nut 220 can be threaded onto a shaft 222 of the bolt.
[0064] The shaft of the bolt can be rebar (reinforcing bar) with a discontinuous external thread formed on its external surface). The nut can be or include a spacer or adapter to retain the connector body, or can retain an adapter or spacer in place.
[0065] As shown in FIG. 8 , the nut on the ground support bolt (rock bolt) can be externally threaded to threadingly receive a spacer or adapter 224 thereon. Thus, the connector can be supported directly on the nut of the ground support bolt.
[0066] Alternatively, the nut of the ground support bolt can be removed and replaced by a spacer/adapter to retain the connector or a spacer/adapter can be added to be retained by the nut.
[0067] Lower 124 and upper 126 rings bolt the two portions 100 a, 100 b together. The bolts 128 can pass through both rings or separate bolts 129 can be used for each ring.
[0068] The connector can be provided with load and/or acceleration sensing devices. For example, an accelerometer 130 can be provided to detect downward movement/acceleration of the connector (and therefore of the connected rock bolt).
[0069] The accelerometer 130 is electrically connected (hard wired or wireless) to communicate with a data receiving means, such as a computer, processor or memory device for later processing of data.
[0070] A load cell 132 can be provided to detect load forces resulting from the impact of the weight(s) and therefore detecting the load applied to the rock bolt. The load cell is applied to a washer or spacer or is formed as a ring between the nut 122 retaining the shaft and the second attachment means 116 . Thus, acceleration data and load data can be gathered and analysed to determined load forces applied to the rock bolt and detect any movement of the rock bolt resulting from the test.
[0071] As with the first attachment means, the second attachment means 116 includes a curved surface 136 arranged to contact a complimentary curved surface 138 on the inside of the cavity formed by the two body portions of the connector.
[0072] The first attachment means 104 has a curved surface 106 that contacts a complimentary curved surface 108 on the inside of the cavity 110 of the connector. The curvature of each surface is preferably part spherical to allow angular degree of freedom for the connector body 112 (comprising the two connected portions) about the head of the rock bolt.
[0073] The test system 200 includes a connector 100 (as shown in FIG. 4 ) from which is suspended a shaft 202 and assembly of weights 204 . FIG. 6 is a cross sectional view, and shows the connector 100 connected to a rock bolt 10 .
[0074] The weights 206 are plates stacked one on top of another to achieve the desired downward force and to apply a required shock force to the rock bolt through the assembly when the weights are dropped and then arrested by the weight stop 208 attached to the lower end of the shaft.
[0075] The weights are supported on a lower plate 210 and safely retained in place by an upper retainer plate 212 by through bolts 214 and retainer nuts 216 . The wavy horizontal lines A,B in FIGS. 5 and 6 indicate that the shaft can be of any desired length.
[0076] In use, the connector is connected to an adapter or to the first attachment means attached to the rock bolt head. The shaft and weights are suspended from the connector. The desired amount of weight is set for release by a release mechanism to allow the weights to drop down the shaft. The shock of the arrested weights is measured as a sudden pull force on the rock bolt, and any movement of the rock bolt and the amount of force applied can be measured respectively by the accelerometer and load cell in the connector. Such dynamic testing on rock bolts or anchor bolts in situ enables the performance of the rock bolt or anchor bolt to be assessed under site specific conditions.
[0077] Benefits of the dynamic test system are that it can apply 25 kJ of energy to the bolt, can detect slip/deformation of the bolt arising from energy application, allows remote release of the weight a a safe distance from the test area, is readily assembled for use and disassembled on site, and can be installed and operated by one or two personnel.
[0078] FIGS. 9 and 10 show respective side views of the connector of a dynamic testing system according to an alternative embodiment of the present invention. Reference numbering is the same as for the embodiment shown and described with reference to FIG. 4 .
[0079] However, the embodiment shown in FIGS. 9 and 10 further includes a bolt 133 projecting through a gap 137 provided between the two halves 100 a, 100 b of the connector when assembled. The bolt, is mounted into the retaining nut 122 immediately above the load cell 132 , and, in conjunction with an additional washer 135 (with its tab 135 a ) below the load cell, helps to protect the load cell 132 and its electrical connector 132 a from impact damage. It was realised during trials of the dynamic testing system that the load cell and/or its electrical connector could become damaged in situations where the connector was initially not vertical when connected to the rock bolt and the load dropped, causing the connector to articulate via the complimentary curved surfaces 106 , 108 and 136 , 138 whereby the electrical connector of the load cell could suffer impact. The bolt and washer protect the load cell, and particularly the load cell electrical connector, during such relative movements of the two halves 100 a, 100 b and the first and second attachment means 104 , 116 .
[0080] The shaft adaptor 120 also includes a releasable locking fastener 141 (e.g. a locking bolt or screw) to help retain the shaft 118 to the adaptor.
[0081] FIG. 11 shows a perspective view of the connector shown in FIGS. 9 and 10 .
[0082] FIG. 12 shows a cutaway view of the connector 100 according to the embodiment discussed above in relation to FIGS. 9 to 11 . The cutaway view shows the nearest connector half 100 a removed and the second connector half 100 b remaining in position.
[0083] The bolt 133 is shown projecting though the opening 137 formed by the cut-outs 143 a, 143 b in the respective connector halves 100 a, 100 b. The washer 135 is shown with washer tab 135 a projecting into the opening 137 . Thus, the load cell 132 and particularly its electrical connector 132 a are protected from impact damage from above by the bolt 133 and from below by the washer and its tab 132 a.
[0084] The mating face 145 of the connector half 102 b shown includes locating projections 147 which match with corresponding recesses in the respective mating face of the other half 100 a for correct positioning when connecting the two halves together.
[0085] FIG. 13 shows a sectional view through the connector 100 . This view clearly shows the internal arrangement of components within the connector of the dynamic testing system. The first connector 104 releasably attaches to the rock bolt/anchor via a nut 149 and shaft 151 of the pre-installed rock bolt/anchor.
[0086] FIGS. 14 a and 14 b show how the connector 100 allows the supported shaft 118 , 202 and weights assembly to be supported vertically from a non-vertical ground support bolt 153 . The cooperating curved surfaces 108 , 138 on the inside of the connector halves 100 a, 100 b allow the upper first connector portion 104 and lower second connector portion 116 to rotate relative to one another and relative to the two halves 100 a, 100 b. Thus, testing of non-vertically installed ground support bolts can carried out in-situ. This helps to ensure that load forces applied through impact of the weights when dropped are transferred through the shaft 118 , through the connector to the ground support bolt as effectively as possible, and such articulation provided by the connector allows more ground support bolts to be tested in situ even if they are non-vertical and thus not ideally positioned. This helps to increase the overall number of ground support bolts tested and thereby improves mine safety.
[0087] FIGS. 15 and 16 show respective perspective and side sectional views of the dynamic testing system 200 of an embodiment of the present invention. The connector 100 previously described above connects overhead to a rock bolt (not shown) in situ in a mine roof, as in FIG. 6 .
[0088] The system as shown in FIGS. 15 and 16 is similar to that system shown and described in relation to FIGS. 5 and 6 . However, the weights 206 are provided in set stacks, each stack comprising a number of weights, and each stack including fork lift lift/lower points 226 a, 226 b allowing groups of weights to be added or removed from the load 204 by a fork lift truck rather than manually moving one weight plate at a time by one or two people.
[0089] Operation of the testing system with the connector has been conducted in-situ at two mine sites.
[0090] A pictorial summary of test data achieved from the two mine site tests is shown FIG. 17 , which shows the data from Table 1 below.
[0091] Rock characteristics from the first mine site test (mine site 1) were UCS (Uniaxial Compressive Strength) of 200-310 MPa and a Q factor (Barton et al 1993) of 25-50.
[0092] For the second mine site test (mine site 2), the rock characteristics were a UCS of around 156 MPa and a Q factor of 2.5.
[0000]
TABLE 1
Bolt
energy
slip
Mine site
No.
drop
(kJ)
(mm)
Mine 1
1
1
17.23
40
1
2
17.23
60
2
1
33.13
207
3
1
33.13
393
4
1
33.13
—
6
1
33.13
—
Mine 2
1
1
17.1
150
1
2
17.1
69
2
1
19.4
407
2
2
19.4
—
4
1
19.4
—
5
1
12.6
119
5
2
12.6
43.5
6
1
12.6
216.6
6
2
12.6
240
8
1
12.6
120
8
2
19.4
85
9
1
26.3
350
[0093] For the testing, although the rock bolts were numbered consecutively 1, 2, 3, 4 . . . etc., some rock bolts were not tested. Hence, rock bolt number 5 not tested at the first mine site and rock bolts 3 and 7 not being tested at the second mine site. The results Table 1 above shows the amount of slippage (movement) of the rock bolt under dynamic test in-situ for a given applied load (energy applied). As can be seen from the table, some rock bolts were tested more than once.
[0094] In use, a required amount of weight is suspended from the in-situ rock bolt/anchor through the connector 100 and shaft 118 , 202 set-up. The weights are raised up the shaft and retained in that raised position via a quick release mechanism. When the quick release mechanism is operated, the weights fall down the shaft and are very rapidly stopped on impact with the base retaining plate 208 and pad 209 . Kinetic energy is thus transferred through the shaft and connector to the rock bolt/anchor. That energy transfer is recorded by the load cell and any movement of the rock bolt/anchor is measured by the accelerometer.
[0095] The connector allows articulation of the shaft and weights relative to the non-vertical rock bolt/anchor so that a vertically applied force is transferred to the non-vertical rock bolt/anchor in-situ in a mine roof. | A connector, an associated dynamic testing system and method for testing rock bolts or rock anchors in situ. The connector is attached to a rock bolt/anchor and supports a hanging load via a shaft. The connector has a body of two halves retaining upper first and lower second connectors having respective curved surfaces. Each of the two halves has a curved inner surface allowing limited relative rotational movement of the first and second connectors relative to the two halves when a load is applied. A load cell and accelerometer register the load applied to the rock bolt/anchor through the connector and any resulting movement of the rock bolt/anchor. | 5 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional Patent Application No. 60/502,341, filed Sep. 12, 2003, the teachings of which are incorporated herein by reference for all purposes.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to injection molding machines, and in particular to valve gate systems for injection molding machines, and injection molding machines having molds using valve-gate systems for controlling the injection of molten plastic into the mold chamber.
[0003] Valve-gate systems have the advantage of creating a clean, flush gate mark, when minimal vestige height is required on the molded part. Apart from a cosmetic viewpoint, larger orifices allowed by valve gates prevent drooling, reduce shear heat and molded-in stress, provide easier filing and reduce injection pressure. Valve-gates are typically part of a larger unit (commonly referred to as “valve-gate unit”) that is mounted behind the gate area, in firm contact with the hot runner's manifold. More issues regarding existing valve-gate unit designs are raised below.
[0004] While existing valve gate systems create quality gates on molded parts, they also suffer from certain shortcomings, as described below.
The valve pin or stem of a valve gate unit is actuated typically by pneumatic or hydraulic systems, included in the body of the valve-gate unit, which contributes to increase valve pin length. Pneumatic or hydraulic actuating systems included in heated valve-gate units are continuously subjected to high temperatures, and therefore likely to suffer from problems associated with thermal expansion. Pneumatic or hydraulic actuating systems mounted behind the manifold require cooling. If no cooling is available, they generally will require regular maintenance checks (e.g., to inspect and/or change o-rings, etc.), which adds to the overall cost of the operation of the machine. Presence of pneumatic or hydraulic systems in valve-gate units may limit the use of back-to-back gating for stack molds. In such cases, when using a single manifold, staggered placement of gates may be required, resulting in increased projected area. It is noted that back-to-back mounting can be achieved if using multiple manifolds, but, in such cases, equalizing flow in all runners (e.g., to avoid preferential flow) becomes an issue. Many of the existing valve-gate systems have no form of adjustment of the valve pin length. An adjustment of some sort is typically necessary to bring the valve pin flush with surrounding molding surface. Existing systems that have this adjustment still require a fair amount of work, even with the mold in the injection press, resulting in increased downtime.
[0010] There is therefore a need for an improved valve-gate unit that does not suffer from these issues.
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention provides a valve gate system and an injection molding machine having such a valve gate system, where the activating unit of the valve gate system is located in an unheated area of the injection molding machine and where an element of the activating unit extends through the injection molding machine to engage and activate the valve gate of the valve gate unit.
[0012] In one embodiment, the present invention provides a valve gate system for an injection molding machine, having a valve gate unit configured to be in contact with a manifold of an injection molding machine for delivering a molten plastic flow from a hot runner system to an injection chamber. The valve gate unit has a valve pin for controlling the flow of the molten plastic from a hot runner system to an injection chamber and an activating unit coupled with the valve gate unit. The activating unit is configured to be mounted external to a mold unit that houses the injection chamber. In addition, the activating unit has an element that extends through the mold unit to engage the valve pin, so as to control the molten plastic flow from a runner system to an injection chamber.
[0013] For a further understanding of the nature and advantages of the invention, reference should be made to the following description taken in conjunction with the accompanying drawings. The drawings described below are merely exemplary drawings of various embodiments of the present invention which should not limit the scope of the disclosure and claims herein. One of ordinary skill would recognize many variations, alternatives, and modifications. These variations, alternatives, and modifications are intended to be included within the scope of the present invention, which is described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is an exemplary schematic diagram of one embodiment of a valve gate unit in accordance with the present invention shown as a part of a single-face multi-cavity mold.
[0015] FIG. 2 is an exemplary schematic diagram showing an enlarged detail view of the valve-gate unit of FIG. 1 .
[0016] FIG. 3 is an exemplary schematic diagram of one embodiment of a valve gate unit and the activating unit in accordance with the present invention shown as a part of a single-face multi-cavity mold.
[0017] FIG. 4 is an exemplary schematic diagram showing an enlarged detail view of the activating unit of FIG. 3 .
[0018] FIG. 5 is an exemplary schematic diagram showing another enlarged detail view of the activating unit of FIG. 3 .
[0019] FIGS. 6A and 6B are exemplary schematic diagrams showing additional detail views of the activating unit of FIG. 3 .
[0020] FIG. 7A is an exemplary schematic diagram of a curved activating slot of the valve gate unit of FIG. 1 .
[0021] FIG. 7B is an alternate exemplary schematic diagram of an activating slot of the valve gate unit of FIG. 1 .
[0022] FIGS. 8-9 are exemplary schematic diagrams showing engagement positions on the slot of FIG. 7A .
[0023] FIGS. 10 A-B are exemplary schematic diagrams showing engagement positions of the activating rod on the slot of FIG. 7A .
[0024] FIGS. 11-13 are exemplary schematic diagrams of alternate embodiments of a valve gate unit in accordance with the present invention shown as a part of a single-face multi-cavity mold.
[0025] FIG. 14 is an exemplary side view schematic diagram of an alternate embodiment of a valve gate unit and the activating unit having a multi-piece activation bar in accordance with the present invention shown as a part of a single-face multi-cavity mold.
[0026] FIG. 15 is an exemplary schematic diagram showing engagement positions of the activating rod of FIG. 14 . FIG. 15 shows the mold of FIG. 14 opened, for example, for the removal of valve gate unit(s).
[0027] FIGS. 16-19 are exemplary detailed view schematic diagrams of the multi-piece activation bar of FIG. 14 ; with activating inserts and connecting bars shown separated in a top view ( FIG. 16 ); front view ( FIG. 17 ) and assembled shown in top view ( FIG. 18 ) and front view ( FIG. 19 ).
[0028] FIG. 20 is an exemplary detailed schematic diagram of a connection of the pieces of the multi-piece activation bar of FIG. 14 .
[0029] FIG. 21 is an exemplary cross sectional diagram through a stack mold using back-to-back gating.
[0030] FIG. 22A is an exemplary plan view diagram of a multi-cavity mold (seen from the parting line), shown with two activating units.
[0031] FIG. 22B is an alternate exemplary plan view diagram of a multi-cavity mold (seen from the parting line), shown with two activating units and using a multi-piece activating bar.
[0032] FIG. 22C is an alternate plan view diagram of FIG. 22B , seen from an opposite end.
[0033] FIG. 23 is an exemplary side view diagram of a stack mold, shown from the side where the activating units are mounted.
[0034] FIGS. 24 A-C are exemplary schematic diagrams showing a first alternate embodiment of the valve gate unit in accordance with the present invention.
[0035] FIGS. 25 A-C show the embodiment of FIGS. 24 A-C with the valve gate closed.
[0036] FIGS. 26 A-C are simplified views of the embodiment of FIGS. 24 A-C, shown with the valve gate open.
[0037] FIGS. 27 A-C simplified views of simplified views of this embodiment, shown with the valve gate closed.
[0038] FIGS. 28 A-C are exemplary schematic diagrams showing a second alternate embodiment of the valve gate unit in accordance with the present invention.
[0039] FIGS. 29 A-C show the embodiment of FIGS. 28 A-C with the valve gate closed.
[0040] FIGS. 30 A-C are simplified views of the embodiment of FIGS. 28 A-C, with the valve gate open.
[0041] FIGS. 31 A-C are simplified views of the embodiment of FIGS. 28 A-C, with the valve gate closed.
[0042] FIGS. 32 A-C are exemplary schematic diagrams showing a third alternate embodiment of the valve gate unit in accordance with the present invention.
[0043] FIGS. 33 A-C show the embodiment of FIGS. 32 A-C with the valve gate closed.
[0044] FIGS. 34 A-C are simplified views of the embodiment of FIGS. 32 A-C, with the valve gate open.
[0045] FIGS. 35 A-C are simplified views of the embodiment of FIGS. 32 A-C, with the valve gate closed.
DETAILED DESCRIPTION OF THE INVENTION
[0046] The embodiments of the present invention, described herein, may be used for single cavity molds, as well as with multi-cavity (e.g., single-face and stack) molds.
[0047] The embodiments of the present invention use a combination of pneumatic-mechanical actuating system for the movement of the valve pin. The pneumatic component (e.g., pneumatic cylinder) of the actuating system is brought outside the mold, leaving only mechanical components in the mold. The pneumatic cylinder runs cold, which helps protect its components from heat expansion and extend the life of its seals (e.g., o-rings). Also, maintenance checks and service are easier for cylinders located outside the mold, where they are easily accessible. The pneumatic actuating component being removed from the valve-gate unit, enables the back-to-back mounting of valve-gate units for stack molds.
[0048] An embodiment of the valve-gate unit in accordance with the present invention is shown in FIG. 1 as part of a single-face multi-cavity mold. Such a mold typically includes the following items: a bottom plate 1 , stripper plate 2 , stripper rings 3 (secured to stripper plate 2 ), cores 4 (secured to bottom plate 1 ), cavity blocks 5 secured to cavity plate 6 , gate inserts 7 (secured in cavity blocks 5 ), manifold plate 8 , housing manifold 9 , top plate 10 , and valve-gate units 11 (secured to cavity plate 6 ). It should be understood that additional components (not shown or described here) can be part of such a mold, and different mounting methods than the one described can be used, without departing from the scope of the present invention.
[0049] In a manner typical to the injection process, at the beginning of each injection cycle the mold closes and molten plastic is injected, through the hot runner system (e.g., as shown including a manifold 9 and a nozzle unit 12 ), in the injection chambers 13 formed between the active faces of cores 4 and cavity blocks 5 . The active end of nozzle unit 12 shown in FIG. 1 is housed in gate insert 7 , but can be housed directly in a pocket in cavity block 5 (e.g., gate insert 7 is optional). At the end of the injection cycle, the mold opens and the stripper plate 2 moves away from bottom plate 1 for a short distance, causing the stripper rings 3 to strip the molded parts 14 off cores 4 . The molded parts 14 fall through the opening between the mold halves, and the injection machine closes the mold for the beginning of a new cycle.
[0050] The valve-gate system in accordance with the embodiments of the present invention includes two main units: the valve-gate unit 11 (as shown in FIG. 1 ), secured to cavity plate 6 and in contact with manifold 9 , and the activating unit 31 (as shown in FIG. 3 ), mounted on the side of the mold, and having elements that go through the mold, to valve-gate units 11 .
[0051] Melt-flow channels through manifold 9 bring molten plastic to valve-gate units 11 . Valve-gate units 11 can have one flow channel connecting to nozzle unit 12 , or they can have two flow channels (e.g., as shown in FIG. 3 ), diverging from a common entry point (e.g., matching exit channel of manifold 9 ), and converging at interface with nozzle unit 12 . Sealing between manifold 9 and valve-gate unit 11 , and between valve-gate unit 11 and nozzle unit 12 , is achieved by the thermal expansion of these components. In single-face molds, pressure pads 78 are mounted between manifold 9 and top plate 10 , in line with the gate (one pressure pad for each injection point—e.g., see FIG. 1 ). Pressure pads 78 are used to counteract the injection pressure from the gate, and aid with sealing when components expand during mold cycles. In stack molds with back-to-back gating, pressure pads may not be needed as the injection pressures equalize on sides of manifold.
[0052] An enlarged detail of the valve-gate unit 11 from FIG. 1 is shown in FIG. 2 . It includes a valve pin or stem 15 going through nozzle unit 12 and through a central hole in the body of valve-gate unit 11 . It has an enlarged cylindrical portion 16 , followed by a reduced cylindrical end 17 . A flanged sleeve 18 is mounted on this end, followed by a retainer 19 , these two components being locked in place with a retaining ring 20 . Although these items are employed and described in the present design, it should be understood that any system producing a similar result could be used on this end of valve pin 15 . Flanged sleeve 18 and retainer 19 move in a pocket 21 in the body of valve-gate unit 11 . Pocket 21 is round on one side, and open to the other side, towards the exterior of the body of valve-gate unit 11 . A yoke 22 is located in the open end of pocket 21 , pivoting around a pivot-pin 23 secured in the body of valve-gate unit 11 . The forked end 24 of yoke 22 is located in the space between flanged sleeve 18 and retainer 19 (mounted on reduced cylindrical end 17 of valve pin 15 ). Yoke 22 has a spherical end 25 on the opposite side, which can move in a rounded slot/activating profile 26 in an activating bar 27 . A cover cap 28 , bolted to body of valve-gate unit 11 , acts as guide for activating bar 27 . A thermal plate 29 prevents heat transfer from body of valve-gate unit 11 , which is heated, to activating bar 27 and cover cap 28 . A cover plate 30 is bolted at top of valve-gate unit 11 , to separate pocket 21 from manifold 9 .
[0053] One activating bar 27 can be used to activate several valve-gate units 11 located along the same axial line. The activating bar 27 extends to one side of the mold, where it is connected to the activating unit 31 , as shown in FIG. 3 . An enlarged detail of the activating unit 31 of FIG. 3 is shown in FIG. 4 . The activating unit 31 includes a base guide 32 , an adjusting nut 33 , an adjustable cylinder support 34 and a pneumatic cylinder 35 . Base guide 32 is a round piece, extended with a squared base 36 that is secured to the side of the mold with bolts 37 (as shown in FIGS. 4, 5 and 6 B). On the opposite end, base guide 32 has an outer thread 38 , for engagement of adjusting nut 33 . Base guide 32 has a central cylindrical hole with one axial slot 39 . Adjustable cylinder support 34 is in the shape of a sleeve with a flanged end. A transversal key 40 is press-fit in an axial slot 41 on the outer surface (on the sleeve portion) of adjustable cylinder support 34 . Sleeve portion of adjustable cylinder support 34 is inserted in central hole of base guide 32 , with transversal key 40 sliding in axial slot 39 . Transversal key 40 prevents rotation of adjustable cylinder support 34 in reference with base guide 32 . Adjustable cylinder support 34 is loosely secured to adjusting nut 33 with shoulder bolts 42 . As shown in FIG. 6A , outer surface of adjusting nut 33 has a notched portion 43 (for ease of handling), extending with a narrow cylindrical portion 44 , marked with a number of indentations 45 . One “origin” indentation 59 is marked on the outer surface of flange portion of adjustable cylinder support 34 . Indentations 45 are used for precise adjustment in reference with “origin” indentation 59 .
[0054] Pneumatic cylinder 35 is secured onto the end face of adjustable cylinder support 34 with bolts 46 , as shown in FIG. 4 . External end 48 of piston 47 of pneumatic cylinder 35 has an internal thread 49 . A connector 50 , in the shape of a square prism, has a threaded extension 51 at one end (for engagement in piston 47 ) and a central slot 52 at the other end (as shown in FIG. 5 , which is a top view of system from FIG. 4 ). End 53 of activating bar 27 is secured in central slot 52 with a low-head bolt 54 . Four (4) access holes 55 are located, at 90° intervals, on middle portion of base guide 32 , to provide access to low-head bolt 54 . Piston 47 of pneumatic cylinder 35 actuates connector 50 , which in turn directs activating bar 27 in a push-pull movement. Bar 27 has one rounded slot/activating profile 26 for each valve-gate unit 11 it activates. Activating slot 26 runs along a curve/spline 56 (as shown in FIGS. 3, 7A , 8 , 9 , 10 , and 14 ), and holds the spherical end 25 of yoke 22 previously described. Yoke 22 cannot move axially (in the direction of movement of activating bar 27 ), as it is held in body of valve-gate unit 11 , but can pivot around pivot pin 23 . The push-pull movement of activating bar 27 makes the rounded slot 26 guide the spherical end 25 of yoke 22 in an up-and-down movement, in a manner that will be described in more detail later. In other words, the up-and-down movement of the spherical end 25 causes yoke 22 to pivot around pivot-pin 23 , which makes the forked end 24 of yoke 22 move down-and-up respectively, bringing the valve pin 15 with it. Valve pin 15 opens and close once per injection cycle. The pneumatic cylinder 35 receives a signal from the injection machine, which correlates movement of valve pin 15 with mold cycles.
[0055] The 3 positions on curve 56 (as shown in FIG. 7A ), are next described, with correlation to FIGS. 8, 9 , 10 A, and 10 B. In the case described here, curve 56 is an arc (e.g., a portion of a circle).
Position “0” (zero), also shown in FIGS. 8 and 10 A, corresponds to valve-gate being closed (when injection is stopped). Piston 47 , connector 50 and activating bar 27 are fully retracted ( FIG. 10A ), which corresponds to 0° rotation of yoke 22 . In this position, forked end 24 of yoke 22 is lowered, bringing valve pin flush with surrounding surface of injection chamber 13 . Position “1”, also shown in FIGS. 9 and 10 B, corresponds to valve-gate being fully opened (when injection is in progress). Piston 47 , connector 50 and activating bar 27 are extended at full stroke S ( FIG. 10B ), which corresponds to rotation “A” of yoke 22 . In this position, forked end 24 of yoke 22 is lifted at maximum, retracting valve pin 15 by amount “B” ( FIG. 9 ). Note: Spherical end 25 of yoke 22 moves repeatedly from “0” to “1” and back to “0” during mold cycles (once per mold cycle). Position “2” is at the quadrant of curve 56 traveled by spherical end 25 of yoke 22 . Valve pin 15 can be adjusted to move towards injection chamber 13 (to bring it flush with surrounding surface, or to eliminate plastic leaks at gate, etc.) by moving spherical end 25 of yoke 22 anywhere between “0” and “2”. Quadrant “2” is the highest position the spherical end 25 can reach, and corresponds to the furthest out the valve pin 15 can go towards injection chamber 13 . If spherical end 25 of yoke 22 is at “2” and valve pin is below surrounding surface of injection chamber 13 , it cannot be adjusted any further and will need to be replaced with a longer pin.
[0059] Stroke S is an in-built feature of pneumatic cylinder 35 used, and its value is thus typically a constant. Values “A” and “B” are a result of the combination of stroke S of pneumatic cylinder 35 used, geometry of curve 56 , and shape and size of yoke 22 . These values can be varied depending on desired result.
[0060] Procedure to adjust activating unit:
[0061] In order to adjust the activating unit, the following procedure may be followed:
1. Mold is stopped. 2. Shoulder bolts 42 are loosened slightly (but not removed) to allow a little clearance between adjustable cylinder support 34 and adjusting nut 33 . 3. Adjusting nut 33 is rotated while adjustable cylinder support 34 is slowly pulled away from (or moved inward into) base guide 32 , as shoulder bolts 42 bolted in adjusting nut 33 rotate in annular groove 57 of adjustable cylinder support 34 . This movement increases or reduces adjustment gap 58 between front of base guide 32 and flanged portion of adjustable cylinder support 34 . 4. Indentations 45 of adjusting nut 33 help mold operator control the adjustment precision in reference with the origin indentation 59 of adjustable cylinder support 34 . 5. When desired adjustment has been reached, shoulder bolts 42 are tightened, locking adjusting nut 33 and adjustable cylinder support 34 together. When these two items are locked together, they are also locked into position, in reference to base guide 32 . This is achieved by the combination of transversal key 40 and thread 38 . As transversal key 40 allows only axial movement of adjustable cylinder support 34 in reference to base guide 32 , when shoulder bolts 42 are tightened, they also force the threads of adjusting nut 33 against the opposing threads of base guide 32 , resulting in a solid, precise engagement of all the components of activating unit 31 . 6. Steps 2, 3, 4, and 5 are repeated for each activating unit 31 mounted on mold, depending on performance of valve pins 15 . 7. Once all activating units 31 have been adjusted, the mold can be started again.
[0069] A more detailed explanation of the correlation between adjustment on activating unit 31 and location of spherical end 25 of yoke 22 on curve 56 follows, in reference with FIGS. 7A, 7B , 8 , 9 , 10 A and 10 B. Position “1” is at the bottom of rounded slot/activating profile 26 . Position “0” is located, along the length of the activating bar 27 , at a distance, from “1”, equal to the stroke S of pneumatic cylinder 35 . Position “2” is always at the quadrant of curve 56 . When adjustment gap 58 is altered (unit 31 is being adjusted), adjusting nut 33 , adjustable cylinder support 34 , and pneumatic cylinder 35 move relative to base guide 32 , bringing connector 50 and activating bar 27 with them. This means that adjustments modify location of position “0” relative to position “2” on curve 56 . Since distance, along length of activating bar 27 , between “0” and “1” is constant (equal to stroke S of pneumatic cylinder 35 ), position “1” also moves with every adjustment. Valve pin 15 will need to be replaced with a longer one when it requires adjustment beyond position “2”.
[0070] A feature of curve 56 (of rounded slot/activating profile 26 ) that influences the closing speed of valve pin 15 is discussed below, with reference to FIGS. 7A and 7B . When spherical end 25 of yoke 22 moves along curve 56 from “1” to “0”, its speed decreases as the angle of the curve reduces. This translates into the valve pin slowing down slightly as it reaches the gate, allowing for a smooth closing. For comparison purposes, FIG. 7B shows a straight activating slot 26 (straight from “1” to “0”), which would result in a constant closing speed of the valve pin 15 .
[0071] For comparison purposes, FIG. 10A shows activating unit 31 , complete with activating bar 27 , in position “0”, while FIG. 10B (below it) shows same system in position “1”. Piston 47 is retracted in FIG. 10A , bringing spherical end 25 of yoke 22 in position “0”, and extended in FIG. 10B , bringing spherical end 25 in position “1”. Yoke 22 is shown at the left of the figures for clarity.
[0072] One embodiment of this invention is directed to the use of a one-piece activating bar 27 , the distance between activating slots 26 being determined by the pitch of the mold. An alternate embodiment, however, uses a multi-piece activation bar ( FIGS. 14, 15 ), where the activating profile 26 is part of an activating insert 60 , made of high-wear material. The mold pitch influences the length of connecting bars 61 that connect activating inserts 60 . As shown in FIGS. 16 through 20 , slotted activating inserts 60 and connecting bars 61 have a tongue-and-groove style joint 62 , locked with a transversal key 63 of square section. Transversal key 63 has a cylindrical extension 64 with a groove 65 . A washer 66 and a retaining ring 67 (pushed in groove 65 ) lock the transversal key 63 in place, which in turn locks the slotted activating inserts 60 in connecting bars 61 and in activating bar 27 . Transversal key 63 has a knurled cylindrical flange 68 at opposite end, which is used for handling.
[0073] The multi-piece embodiment has several advantages in regards to servicing of the valve-gate unit. For a single-face mold (as shown in FIGS. 11, 12 and 13 ) the procedure to service the valve-gate unit is as follows:
1. Mold is closed in the injection machine. Valve-gates must be closed (pistons 47 of pneumatic cylinders 35 are fully retracted). 2. Safety straps 69 are installed between top plate 10 and cavity plate 6 (shown with phantom lines). Mold is opened and bolts 70 are removed. Mold is closed again. 3. Safety straps 69 are then installed between cavity plate 6 and bottom plate 1 . 4. Mold is opened slowly, as shown in FIG. 12 , bringing cavity plate 6 , manifold plate 8 (which is secured to cavity plate 6 ), and valve-gate units 11 (secured to cavity plate 6 ) with the core half, away from cavity side. 5. Manifold 9 stays with top plate 10 , as it is secured to top plate 10 with bolts 71 . 6. When mold is opened this way, valve-gate units 11 are exposed and can be removed, one at a time, for service, cleaning etc. To do that, bolts 72 (that secure valve-gate unit 11 to cavity plate 6 ) can be removed, as shown in FIG. 13 . Retaining rings 66 (see FIG. 20 ) are removed from grooves 65 of cylindrical extensions 64 , and transversal keys 63 are then removed. Slotted activating insert 60 can then be easily disengaged from connecting bars 61 (which will stay in the mold, attached to adjacent valve-gate units) and valve-gate unit 11 (together with its activating insert 60 ) can be lifted out of the mold, using threaded portion of holes for bolts 72 as jacking holes 73 . After changes, cleaning, service etc. valve-gate unit 11 can be returned to the mold and secured back in it, in reverse order. Another valve-gate unit 11 can then be removed in the same manner.
[0080] FIG. 14 shows a side view of a single-face multi-cavity mold, in closed position, using a multi-piece activating bar 27 . FIG. 15 shows same mold being opened in the manner described above, for removal of valve-gate units 11 . FIGS. 16 through 19 are detailed views of multi-piece activating bar 27 , with activating inserts 60 and connecting bars 61 shown separated in top view ( FIG. 16 ) and front view ( FIG. 17 ), and assembled (complete with transversal keys 63 , washers 66 , and retaining rings 64 ), shown in top view ( FIG. 18 ) and front view ( FIG. 19 ).
[0081] FIG. 21 shows a cross section through a stack mold using back-to-back gating. Valve-gate units 11 are shown, complete with activating bar 27 (one-piece option shown) and activating units 31 mounted to side of mold. Valve-gate units 11 are be heated, to hold desired temperature of molten plastic as it transits from manifold 9 to nozzle unit 12 . Different types of heating elements 74 can be used (coil heaters wrapped around body of valve-gate unit 11 , or bar-type heaters inserted in the body of the valve-gate unit 11 as shown in FIG. 21 , etc.). Wires 75 extending from heaters 74 are directed through pockets in the mold, similar with wires 76 coming from nozzle unit 12 , and wires 77 coming from heaters of manifold 9 .
[0082] FIG. 22A is a plan view of a multi-cavity mold (seen from the parting line), shown with two activating units 31 . The two cavities at the bottom of the mold are shown with valve-gate open (one-piece activating bar 27 is extended at full stroke S of pneumatic cylinder 35 , as shown just below the plan view). The two cavities at the top of the mold are shown with valve-gate closed (activating bar 27 is retracted fully, as shown above the plan view). At the right of the page, valve gate units, complete with nozzle units, are shown open (bottom) and closed (top), corresponding to plan view.
[0083] FIG. 22B shows the same mold in plan view, but using a multi-piece activating bar 27 . FIG. 22C is a plan view of the same mold from FIG. 22B , seen from opposite end—after top plate 10 and manifold 9 are removed. The valve-gate units 11 and multi-piece activating bars 27 are visible, and valve-gate units 11 can be removed, one by one, as previously described.
[0084] FIG. 23 is a side view of a stack mold, shown from the side where the activating units 31 are mounted.
[0085] FIGS. 24 A-C are exemplary schematic diagrams showing a first alternate embodiment of the valve gate unit in accordance with the present invention.
[0086] The embodiment of FIGS. 24 A-C uses a pair of activating bars 27 ′ working in parallel as a rigid unit. They can be of either one-piece or multi-piece design, and are connected in a rigid assembly by means known to those of skill in the art. An activating unit 31 ′, mounted externally on the injection mold, activates both bars 27 ′ simultaneously. A pair of bars 27 ′ may activate one or several valve gate units 11 ′ located along the same axial line. Cover caps 28 ′, secured to opposing sides of the body of valve gate unit 11 ′, act as guides for activating bars 27 ′. Each activating bar has a slot/activating profile 26 ′ for each valve gate unit 11 ′ activated. This embodiment shows a linear, sloped slot, but it should be understood that a rounded slot such as those described above may be used.
[0087] The valve gate unit 11 ′ of this embodiment has a round pocket 21 ′, disposed centrally, opening to the side which comes in contact with manifold 9 ′. A cylindrical guide 80 , in threaded engagement 81 with a cylindrical cage 82 , is located in round pocket 21 ′. A valve stem 15 ′ has a cylindrical flange 83 , located centrally in cage 82 . Flange 83 is firmly held between base of cage 82 and bottom of threaded extension of guide 80 , with no freedom of axial motion. Guide 80 , flange 83 of valve stem 15 ′, and cage 82 form a sliding unit 84 , which can move axially in pocket 21 ′ to repeatedly close or open a valve gate opening into an injection chamber 13 ′ of the injection mold. Such motion of the sliding unit is achieved by a transversal pin 85 , fixedly engaged in guide 80 , and having symmetrical extensions on sides of guide 80 . Ends of transversal pin 85 pass through vertical slots 86 on sides of valve gate unit 11 ′, continuing on through activating profiles 26 ′, and being secured with some means such as retaining rings (as shown) against accidental sliding out of profiles 26 ′. With each extension of the piston 47 ′ of a pneumatic cylinder 35 ′ of activating unit 31 ′, the pair of bars 27 ′ extends, causing the activating profiles 26 ′ to force transversal pins 85 to retract sliding units 84 , so that valve stems 15 ′ open the valve gates. With each retraction of the piston 47 ′, the pair of bars 27 ′ retracts, causing the activating profiles 26 ′ to force transversal pins 85 to extend sliding units 84 , so that valve stems 15 ′ close the valve gates. Vertical slots 86 only allow extend/retract motions along axis of valve stem 15 ′, preventing any sideway motions as could be caused by slots 26 ′ of activating bars 27 ′, acting against transversal pin 85 . A cover plate 30 ′, secured at the top of the valve gate unit 11 ′, separates pocket 21 ′ from manifold 9 ′.
[0088] FIGS. 25 A-C show the embodiment of FIGS. 24 A-C with the valve gate closed.
[0089] FIGS. 26 A-C are simplified views of the embodiment of FIGS. 24 A-C, shown with the valve gate open.
[0090] FIGS. 27 A-C simplified views of simplified views of this embodiment, shown with the valve gate closed.
[0091] FIGS. 28 A-C are exemplary schematic diagrams showing a second alternate embodiment of the valve gate unit in accordance with the present invention.
[0092] The embodiment shown in FIGS. 28 A-C uses a pair of activating bars 27 ′ working in parallel as a rigid unit. They can be of either one-piece or multi-piece design, and are connected in a rigid assembly by means known to those skilled in the art. An activating unit 31 ′, mounted externally on the injection mold, activates both bars 27 ′ simultaneously. A pair of bars 27 ′ may activate one or several valve gate units 11 ′ located along the same axial line. Rollers 87 and support pads 88 guide the extend/retract motions of bars 27 ′, as activated by unit 31 ′. Activating bars 27 ′ transfer this motion, through pins 89 , to side arms 90 , which transfer it further, through transversal pin 85 ′, to a sliding unit 84 ′ (similar to the one described above). Vertical slots 86 ′ in opposite sides of valve gate unit 11 ′ allow extend/retract motions of pin 85 ′, as activated by bars 27 ′. Such motions of pin 85 ′ are transferred directly to valve stem 15 ′ through sliding unit 84 ′. When activating bars 27 ′ are extended, they cause side arms 90 to pull pin 85 ′ to the bottom end of slots 86 ′. Pin 85 ′ brings the whole sliding unit 84 ′ down, which causes the valve stem 15 ′ to close the valve gate as shown in FIGS. 29A , B, and C. When activating bars 27 ′ are retracted, they cause side arms 90 to push pin 85 ′ to the top end of slots 86 ′, bringing the whole sliding unit 84 ′ up, and causing the valve stem 15 ′ to open the valve gate (as shown in FIGS. 28A , B, and C).
[0093] FIGS. 29 A-C show the embodiment of FIGS. 28 A-C with the valve gate closed.
[0094] FIGS. 30 A-C are simplified views of the embodiment of FIGS. 28 A-C, with the valve gate open.
[0095] FIGS. 31 A-C are simplified views of the embodiment of FIGS. 28 A-C, with the valve gate closed.
[0096] FIGS. 32 A-C are exemplary schematic diagrams showing a third alternate embodiment of the valve gate unit in accordance with the present invention.
[0097] The embodiment shown in FIGS. 32 A-C uses a pair of activating bars 27 ′ working in parallel as a rigid unit. They can be of either one-piece or multi-piece design, and are connected in a rigid assembly by means known to those of skill in the art. An activating unit 31 ′, mounted externally on the injection mold, activates both bars 27 ′ simultaneously. A pair of bars 27 ′ may activate one or several valve gate units 11 ′ located along the same axial line. Roller bearings 91 guide the extend/retract motions of bars 27 ′, as activated by unit 31 ′. Activating bars 27 ′ transfer this motion, through a toggle system 92 , to a transversal pin 85 ′, to a sliding unit 84 ′ (similar to the one described above) and to a valve stem 15 ′. The toggle system 92 has of two side arms, 93 and 94 , their connecting pins 95 and 96 , and the transversal pin 85 ′. Pins 95 are fixedly secured onto opposite sides of the valve gate unit 11 ′. Pins 96 connect side arms 93 and 94 , and are allowed motion in vertical slots 97 of activating bars 27 ′. Side arms 94 are further connected to ends of transversal pin 85 ′. Vertical slots 86 ′ on opposite sides of valve gate unit 11 ′ only allow pin 85 ′ an extend/retract motion along axis of valve stem 15 ′. Such motions of pin 85 ′ are transferred directly to valve stem 15 ′ through sliding unit 84 ′. When activating bars 27 ′ are extended, vertical slots 97 cause pins 96 to move simultaneously along horizontal direction of activating bars 27 ′ and vertically towards bottom of slots 97 (which are open at the top). Since side arms 93 can only pivot around pins 95 (when actuated by activating bars 27 ′), the resulting combined horizontal/vertical motion of pins 96 causes side arms 94 to pull transversal pin 85 ′ to bottom end of vertical slots 86 ′. Pin 85 ′ transfers this motion to the sliding unit 84 ′, causing the valve stem 15 ′ to close the valve gate, as shown in FIGS. 33A , B, and C. When activating bars 27 ′ are retracted, vertical slots 97 cause pins 96 to move simultaneously along horizontal direction of activating bars 27 ′ and vertically towards top of slots 97 . Side arms 93 pivot around pins 95 , the resulting combined horizontal/vertical motion of pins 96 causes side arms 94 to push transversal pin 85 ′ to top end of vertical slots 86 ′. Pin 85 ′ transfers this motion to the sliding unit 84 ′, causing the valve stem 15 ′ to open the valve gate, as shown in FIGS. 32A , B, and C.
[0098] FIGS. 33 A-C show the embodiment of FIGS. 32 A-C with the valve gate closed.
[0099] FIGS. 34 A-C are simplified views of the embodiment of FIGS. 32 A-C, with the valve gate open.
[0100] FIGS. 35 A-C are simplified views of the embodiment of FIGS. 32 A-C, with the valve gate closed.
[0101] It should be noted that in all three alternate embodiments described above, S 1 is the stroke of the activating bars 27 ′, along a direction perpendicular to that of valve stem 15 ′. Sliding unit 84 and valve stem 15 ′ have a stroke S 2 , along the centerline of the valve stem 15 ′. Both strokes are shown on FIGS. 24A , B and C of the first alternate embodiment. For the other two embodiments, however, only stroke S 2 is shown, for clarity of the drawing. The two extreme positions of these embodiments (when valve is open and when valve is closed) were not shown on the same drawing to avoid unnecessarily cluttering the figures.
[0102] As will be understood by those skilled in the art, the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. For example, instead of the pneumatic cylinder, a hydraulic one may be used may, or alternately the motive force may be supplied by an electric motor drive. These other embodiments are intended to be included within the scope of the present invention, which is set forth in the following claims. | A valve gate system for an injection molding machine, having a valve gate unit configured to be in contact with a manifold of an injection molding machine for delivering a molten plastic flow from a hot runner system to an injection chamber. The valve gate unit has a valve pin for controlling the flow of the molten plastic from a hot runner system to an injection chamber and an activating unit coupled with the valve gate unit. The activating unit is configured to be mounted external to a mold unit that houses the injection chamber. In addition, the activating unit has an element that extends through the mold unit to engage the valve pin, so as to control the molten plastic flow from a runner system to an injection chamber. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
MICROFICHE APPENDIX
Not Applicable
BACKGROUND OF THE INVENTION
The present invention is in the field of fuel level responsive valves used in vehicle fuel tanks.
Fuel level responsive valves are well known in the art of controlling the venting of fuel vapor from vehicle fuel tanks. These valves typically have a float mechanism trapped within a valve body to move a valve closure element into and out of sealing engagement with a vent outlet in response to rising and falling fuel levels. Such valves are most often employed as rollover valves, responding to fuel slosh or vehicle tilt and rollover situations to protect a vapor-processing canister from liquid fuel, although they can also be used for fill control shutoff and primary onboard vapor control.
Some successful float-operated valves are shown in U.S. Pat. No. 4,753,262 issued to Bergsma, and U.S. Pat. No. 5,313,977 issued to Bergsma, et al., both co-owned with the present application. These valves employ a peelaway type opening action, in which a rigid plastic plate- or paddle-like valve element is initially “cracked” open over a limited segment of its sealing surface with the vent outlet by an actuator attached to the float, and subsequently “peeled” from the vent outlet, either circumferentially or in lever fashion. By initially cracking or peeling only a portion of the valve element from the vent outlet, the pressure differential acting across the valve element is reduced to prevent the float from becoming “hung up”, or lodged in the closed position, unable to overcome the force of the pressure differential acting across the surface area of the valve element to open the valve when fuel level drops. The net downward force comprising the weight of the float, less buoyancy forces is not sufficient to move the entire valve element off the vent outlet at once, because the accumulated force of the vapor pressure differential acting across the entire surface area of the valve element is substantially greater.
Heretofore rigid valve elements have been employed because they are more responsive to the initial “cracking” or “peeling” action of the float. It is therefore necessary to either machine the sealing surfaces of the rigid valve element and the vent outlet carefully to ensure an adequate vapor and liquid seal, or to apply an additional resilient, rubberlike seal member to either the valve element or the vent outlet to improve the seal between them.
Another prior approach has been the use of pliable, ribbonlike valve elements which are opened in a generally continuous peeling fashion. Examples of such valves are shown in the above-described patent to Bergsma, et al. and in U.S. Pat. No. 4,770,201 and published European Patent Application EP 0724098A1 to Zakai, et al.
While pliable, rubber-type valve elements provide improved sealing with the vent outlet, rubber-type seals have tended to provide a continuous peeling action which has been found not as desirable as the cracked-open lever action of rigid valve elements. Such seals have also been found prone to “bunching up” or deforming due to high volume vapor flow, large pressure differentials, and any horizontal sliding motion of the float relative to the vent outlet.
BRIEF SUMMARY OF THE INVENTION
The present invention solves the foregoing disadvantages of the prior art valve with a valve element having a pliable, resilient diaphragm-like seal member peripherally stiffened by a thickened rim to give the resilient seal a lever-type opening action.
In a preferred form, the float has a generally ring-shaped cage or frame which traps the resilient seal member. The trapped resilient seal is preferably stiffened, for example with a thickened edge to provide body or shape holding characteristics to a thin, pliable center section which engages the vent outlet.
The seal member is trapped inside the cage for limited vertical, and preferable also limited horizontal movement within the cage to assist with the opening action.
In the preferred form the cage is integrally formed with the float and has a flexible strip portion or “living hinge” portion which is folded and snap-locked in place after insertion of the seal member in the cage for retaining the seal member in the cage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a vehicle fuel system of the type in which a valve according to the present invention is capable of being used;
FIG. 2 is a perspective view of the rollover vent valve of FIG. 1;
FIG. 3 is a cutaway or section view taken along section indicating lines 3 — 3 of FIG. 2, showing the valve fully open;
FIG. 4 is an enlarged view of a portion of FIG. 3 showing the initial peelaway stage when the seal between the valve element and the vent outlet is first broken;
FIG. 5 is a view showing the valve element further opened from the position of FIG. 4; and,
FIG. 6 is a perspective view of the top of the float with the cage opened for insertion of the valve member.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIG. 1, a valve indicated generally at 16 according to the present invention is shown schematically illustrated in a typical vehicle fuel system environment including a fuel tank 10 , a filler pipe 12 , and a vapor recovery apparatus such as a carbon canister 14 connected to valve 16 by a conduit or hose 17 .
Fuel level responsive vapor control valves such as 16 are typically mounted in the upper wall of fuel tank 10 , positioned to close vapor venting from the tank to canister 14 when fuel level 18 submerges valve 16 , for example during refueling, or during fuel slosh or vehicle rollover conditions. Valve 16 reopens when fuel level 18 drops, or when the slosh or rollover condition is alleviated.
In the illustrated embodiment, valve 16 is depicted as a “rollover” valve typically used in conjunction with one or more additional valves in the fuel tank to supplement refueling vapor control and pressure relief functions. It will be apparent to those skilled in the art, however, that valve 16 incorporating the present invention can be employed in almost any type of fuel level responsive valve, and is not limited to the rollover valve application now described.
Referring next to FIGS. 2 and 3, the inventive valve 16 is illustrated in detail, generally comprising the valve closure and reopening structure at the top of a float mechanism and its relationship to a vapor venting outlet in the upper end of the valve where fuel vapor is vented to the vapor recovery apparatus outside the fuel tank. In particular, valve 16 includes a valve body 20 having a generally hollow cylinder made from a fuel-resistant plastic material, although the exact composition of valve body 20 is not critical to the present invention. Valve body 20 includes an interior float chamber 22 designed to receive a fuel level responsive float 24 in a sliding arrangement. Float chamber 22 typically includes at least one, and usually several lower fuel entry ports (not shown) and one or more higher fuel vapor entry ports (not shown) such that liquid fuel freely enters chamber 22 when the fuel level in the tank reaches valve 16 , thereby forcing the float 24 upwardly toward vapor venting orifice or outlet 32 located in the upper end of the float chamber and having the lower end thereof forming a valve seat 36 . Outlet 32 communicates with a passage 35 on the portion 37 of the valve external to tank 10 , which portion 35 is adapted for connection to conduit or hose 17 connected to canister 14 . The fuel vapor entry ports in the upper end of the valve body, usually in the form of radial windows (not shown) in the sidewall around chamber 22 , admit fuel vapor to be vented through outlet 32 until the outlet is closed by a valve element on the float contacting valve seat 36 .
Float 24 carries a valve closure element indicated generally at 25 on its upper end, captured on the float at one end by flange ring 38 and posts 28 , 29 , 31 and hinged port 30 , illustrated in FIG. 6 as an integral part of float 24 projecting from its upper surface and which forms a cage indicated generally at 33 . The cage 33 thus comprises a flange or ring 38 supported by posts 28 , 29 , 31 and 30 which allow the valve element some limited up and down and side to side travel or lost motion relative to the float for a peelaway type reopening action described in further detail below.
Referring to FIG. 6 hinged post 30 is shown in the open position enabling the valve seal element 26 to be inserted in cage 33 , prior to snap locking the end of post 30 into cutout 39 formed in flange ring 38 .
Valve element 25 is shown in its valve closed position in FIG. 4, forced against vent seat 36 and outlet 32 and is shown in partially peeled open state. In this beginning to open position, valve element 25 is contacted at its rim by the undersurface of the flange or ring 38 .
Referring to FIGS. 3, 4 and 5 , in accordance with the present invention, valve element 25 comprises a soft, pliable, rubberlike seal element 26 .
Valve closure element 25 is preferably a disk-shaped element with a stiffened, preferably, thickened edge 27 , illustrated as an annular bead, surrounding a thin, pliable central webbing or diaphragm-like seal element portion 26 . For purposes of illustration, the central webbing seal element portion 26 is preferably on the order of 0.015 inches (0.38 mm) in thickness, although it will be apparent to those skilled in the art that different thicknesses with different pliability characteristics may be used depending on the valve application. As shown in FIG. 4, central seal element portion 26 makes a closely-conforming seal with valve seat 36 of vent outlet 32 which is generally superior to the seal formed by rigid plastic valve elements. The thin, pliable nature of central seal element portion 26 provides what is known as a “low sealing force” seal with the vent outlet, which is generally desirable in most applications.
The pliable, reinforced rubber seal 26 is trapped for limited vertical and horizontal movement inside cage 33 which results in improved sealing and reopening action. It will be understood that when the fuel level begins to drop float 24 begins to descend in float chamber 22 . Referring to FIG. 4, while the pliable rubber seal 26 remains closed on vent seat 36 of outlet 32 due to the pressure differential between the fuel tank and the canister, and the underside 34 of the flange 38 contacts the upper surface of bead rim 27 and has begun to “crack open” a portion of seal 26 from the vent port valve seat 36 .
This initial cracking or peeling action breaks the seal between rubber disk 26 and vent outlet 32 to begin reducing the pressure differential across rubber seal 26 .
Referring next to FIG. 5, float 24 has dropped further to bring the underside of actuator flange 38 lower to continue the peeling action and break any remaining contact between rubber seal 27 and vent outlet 32 by pulling it straight off the vent outlet. As shown in FIG. 5, the reinforced edge 27 on pliable rubber seal 26 serves to stiffen the overall rubber seal to pull it off the vent outlet in a manner similar to a rigid seal element for the final opening stages.
In FIG. 3, float 24 is shown as having descended far enough to pull valve element 25 completely free from the vent seat 36 of outlet 32 , such that valve element 25 now drops back down to rest on the upper surface of the float, with internal rubber seal 26 dropping down inside paddle frame cage 33 to its ramp-centered lower position on upper surface 40 of float 24 shoulder 26 h.
It will be apparent to those skilled in the art that various modifications may be made to the disclosed structure for different valve applications, without departing from the spirit and scope of my invention. For example, the size and shape of valve element 25 may vary depending on the vent outlet which it is intended to close. The invention is not to be limited by the foregoing exemplary illustrations, except as provided by the following claims. | An improved fuel level responsive peelaway action valve for vehicle fuel tanks, in which a float moves a valve closure element into sealing contact with a vapor venting outlet, and then pulls or “peels” the valve element off the vapor venting outlet when fuel level drops. The valve closure element comprises a thin, flexible sealing portion for engaging the vapor venting outlet with low sealing forces, and a stiffened marginal portion acted on by a rigid cage or frame which is connected to the float. As the float drops, the cage contacts the stiffened marginal portion and levers the valve element off the venting outlet. | 8 |
[0001] The invention relates to accessories for suspended ceiling grid construction and, in particular, to a seismic clip for stabilizing the grid members.
PRIOR ART
[0002] U.S. Pat. Nos. 5,046,294; 7,293,393; and 7,552,567 are examples of seismic clips used to limit movement of the ends of grid tee members at the perimeter of a suspended ceiling grid. There remains a need for an improved seismic clip that, while being economical, is both versatile and easy in installation and rugged in its construction. In particular, the clip should be capable of being both snapped over a grid tee and slipped onto the grid tee end to satisfy the installer's preference or need. The installation of an individual clip should not require a high assembly force or complicated manipulation since a typical job will require the assembly of a clip and tee to be repeated numerous times.
SUMMARY OF THE INVENTION
[0003] The invention provides a seismic clip for suspended ceiling grid tees that offers high strength, rigidity, versatility and ease of assembly while improving the ability of a clip to self-align with a grid tee. The disclosed clip includes a lanced tab that serves to establish and maintain alignment of the clip body and the tee to which it is assembled. More specifically, a tendency of a clip to be tilted upwardly relative to the tee is eliminated or greatly reduced. As a related added benefit, the alignment tab serves to initially align the clip and tee either when it is assembled by snapping it over the tee or by sliding the tee endwise into the clip. The tab is configured so that it does not unduly add to the assembly force level when the clip is snapped over the tee or when the tee and clip are slipped endwise together.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a perspective view of the seismic clip of the invention installed on the end of a grid tee and a wall angle;
[0005] FIG. 2 is a side elevational view of the seismic clip, grid tee and wall angle assembly;
[0006] FIG. 3 is a front elevational view of the seismic clip;
[0007] FIG. 4 is a right side elevational view of the seismic clip;
[0008] FIG. 5 is a left side elevational view of the seismic clip;
[0009] FIG. 6 is a top view of the seismic clip;
[0010] FIG. 7 is a side view of the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] Referring now to the drawings, a seismic clip is used to tie or anchor a grid tee 11 to a wall angle 12 . The illustrated wall angle 12 is of a conventional construction being roll-formed sheet metal typically 10′ or 12′ long (or metric equivalent) and having perpendicular legs 13 of, normally, ⅞″ (or metric equivalent) width. The free edges of the legs 13 are folded back to form stiffening hems 14 . As is conventional, a vertical leg 13 of the wall angle 12 is attached to a wall 16 with screws, nails, staples, or the like at ceiling level.
[0012] The illustrated grid tee 11 can be a main tee or a cross tee, these terms being commonly understood in the industry. Relatively long main tees are assembled with shorter cross tees to make up a suspended grid for supporting rectangular ceiling panels. A conventional tee 11 has a lower flange 17 , a vertical stem or web 18 , and an upper reinforcing or stiffening hollow bulb 19 usually rectangular in form and nominally ¼″ (or metric equivalent) in width.
[0013] The seismic clip 10 is preferably a unitary stamping made of suitable metal such as 0.028″ hot dipped galvanized (H.D.G.) sheet steel. The geometry of the seismic clip 10 is described with reference to its installed orientation.
[0014] In plan view, shown in FIG. 6 , the clip 10 has a generally T-shaped configuration. The clip 10 is essentially symmetrical about a central vertical plane that when installed on a tee 11 , coincides with the plane of the web 18 of the tee. The clip 10 includes a pair of coplanar wings 21 that are perpendicular to and extend in opposite directions away from the central plane of symmetry. In an elevational view, shown in FIG. 3 , the wings 21 are generally rectangular. Tabs 22 that serve as hooks are lanced or stamped from the central areas of the wings 21 . The tabs 22 remain connected to the wings 21 at their upper regions 23 and lie in generally vertical planes, but preferably diverging from the plane of the wings at about 5 degrees, spaced slightly behind the plane of the wings. At the distal upper corners of the wings 21 are holes 24 for receiving screws or nails to fasten the clip 10 to a wall 16 . At the distal lower corners of the wings are similar holes 26 and, optionally concentric small circular embossments or standoffs that assist in keeping the clip in alignment with the planes of the wall 16 and ceiling by accounting for the thickness of the hems 14 .
[0015] A central section or saddle 31 of the clip 10 , forming the stem section of the T-shape of the clip seen in plan view, is proportioned to fit over the bulb 19 and web 18 of the end of a grid tee 11 . The saddle 31 is a double wall structure; the walls, designated 32 , 33 , are in parallel vertical planes. The walls 32 , 33 are spaced apart by an upper web 34 . The web 34 is preferably dimensioned to closely fit the walls 32 , 33 on the sides of the grid tee bulb 19 .
[0016] Below their bulb engaging areas, the saddle walls 32 , 33 are arranged to be spaced from the web 18 of the grid tee 11 . An elongated horizontal slot or opening 36 is formed in each saddle wall 32 , 33 so that the slots oppose one another. Above the slot 36 on each wall 32 , 33 are a pair of holes 37 . Adjacent a forward end or edge 38 of each wall, a tab 39 of trapezoidal shape is bent inwardly from a line or base 41 of attachment with the main body of the respective wall. In its free state, each tab 39 has an upper free or distal horizontal edge 42 configured, when assembled with a tee to extend beneath the bulb 19 and be spaced slightly from the tee web 18 .
[0017] On the right saddle wall 32 there is stamped or lanced a tab 43 . The tab 43 is angled inward and upward from a line or base 44 of attachment with the wall proper. The tab profile is that of a polygon with a forward edge 46 that angles rearwardly and upwardly from its base 44 , an upper horizontal free edge 47 , and a rearward edge 48 perpendicular to its base. Ideally, the tab 43 is similar to the leading tab 39 such that these tabs lie in a common plane and their respective bases 41 , 44 and upper edges 42 , 47 lie along common lines.
[0018] The clip 10 can, at the option of the installer, be assembled on the end of a grid tee 11 by either snapping it over the top of the bulb 19 or by sliding the tee and clip relative to one another in the longitudinal direction of the tee. A line 51 is embossed in the left saddle wall 33 to mark a distance of ¾″ from the plane of the wings 21 to be used as a gauge for the installer where a building code requires the grid tee to be installed not closer than this dimension from the vertical leg 13 of the wall angle 12 . The clip 10 is assembled on a wall angle by lowering it onto the vertical leg 13 with the hooks or tabs 22 behind the leg and the main clip body in front of the leg. This can be done before or after the clip is assembled with the tee.
[0019] The front or leading tabs 39 on the saddle walls 32 , 33 facilitate assembly of the clip onto the tee where the tee is inserted longitudinally into the clip. The leading edges of the tabs 39 guide the grid tee web 18 towards the center of the clip without impeding relative longitudinal motion. The free edges 42 of the tabs 39 are spaced only a limited distance greater than the thickness of the web 18 , so that the bulb 19 is roughly centered before the bulb engages the saddle 31 .
[0020] The lanced tab 43 serves to align the tee 11 and clip 10 so that the clip is restrained from tilting excessively upwardly. This is accomplished by the lanced tab 43 engaging the underside of the reinforcing bulb 19 with its upper edge 47 . The lanced tab 43 can be proportioned to allow some tilt between the clip 10 and tee 11 for ease of assembly and compatibility with various sized reinforcing bulbs. Such tilting is restricted so that where the clip 10 is positioned on the end of the grid tee 11 prior to positioning of the clip onto the wall angle 12 , the tilt is not severe enough to prevent the tabs or hooks 22 from contacting the wall and slipping behind the wall angle 12 . Reference is made to FIG. 7 where a prior art clip is seen to be free to tilt on a grid tee, pivoting about a point 56 of a tab. It will be seen in this figure that the lower edges of the clip wings can strike the upper edge of a wall angle 12 and prevent the hooks of such prior art design from slipping behind the vertical leg 13 of the wall angle 12 . The lanced tab 43 of the present invention can prevent this excessive tilting of the clip 10 thereby facilitating rapid assembly of the clip to the wall angle. Moreover, under seismic conditions, when a cross tee slips outwardly off the wall angle and gravity pulls down on the cross tee to prior art clip assembly, some damage may occur with loosening of the friction fit of the clip to the wall angle and tilting of the clip may occur. With the prior art clip under severe conditions excessive tilting may occur (similar to the showing in FIG. 7 ) and contribute to tile fall out. The lanced tab 43 of the invention wedges the bulb 19 between the lower side of the saddle 31 and the upper edge 47 of the tab 43 thus preventing this excessive tilting.
[0021] The clip 10 can be secured to the wall 16 after it is properly located on the wall angle with screws or nails in some or all of the wing holes 24 , 26 . Depending on the applicable building code, self-drilling screws can be driven into the reinforcing bulb 19 through the holes 37 that abut the sides of the bulb 19 to lock the clip 10 and tee 11 against relative movement. In other cases where limited movement between the clip 10 and tee 11 is desired, a self-drilling screw can be located at the center of the slot 36 and driven into the tee web 18 .
[0022] It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited. | A seismic clip for suspended ceiling grid tees that offers high strength, rigidity, versatility and ease of assembly while improving the ability of a clip to self-align with a grid tee. The clip includes a lanced tab that serves to establish and maintain alignment of the clip body and the tee to which it is assembled whereby a tendency of a clip to be tilted upwardly relative to the tee is eliminated or greatly reduced. The alignment tab serves to initially align the clip and tee either when it is assembled by snapping it over the tee or by sliding the tee endwise into the clip. The tab is configured so that it does not unduly add to the assembly force level when the clip is snapped over the tee or when the tee and clip are slipped endwise together. | 4 |
BRIEF SUMMARY OF THE INVENTION
[0001] This invention relates to an electric motor and battery powered wheeled shopping cart and burden carrier manually pushable or pullable to a shopping area for use during shopping and for thereafter transporting merchandise under motor power by the operator walking along therewith and controlling the dual motors and gearing associated with the rear drive wheels and the travel thereof through the medium of a hand held or cart mounted control device on a lanyard attached to the cart, and whereby charging of the battery may be effected by closing the circuit to the battery and manually pushing the cart to rotate the motor shafts and cycle the amperage back into the battery.
CROSS REFERENCE TO THE PRIOR ART
[0002] While it has heretofore been proposed to provide a shopping service cart with a motorized wheel assembly unit, such as that of Swinny U.S. Pat. No. 3,190,386, and the self-propelled power units for picking up and handling unpowered shopping carts of Hudson U.S. Pat. No. 3,073,404 and Vokes U.S. Pat. No. 3,524,512, and a wheel chair driving and steering apparatus of Schmidt U.S. Pat. No. 2,978,053, none of these devices suggest a self-contained electric motor and battery propelled shopping cart which may be manually pushable or pullable to a shopping area and thereafter returned when loaded under power controlled by the operator walking along therewith and controlling its speed and travel by a control unit arranged on a lanyard attached to the cart.
SUMMARY OF THE INVENTION
[0003] The principal object of this present invention is to provide a shopping service cart and burden carrier having dual electric motors and gearing associated with the rear driving wheels on the flat undercarriage thereof and with a storage battery interposed therebetween, and wherein a lanyard attached to the cart has a hand holdable control unit thereon for controling the speed and travel of the cart under power, and whereby the cart may also be manually pushed or pulled without power.
[0004] Another object is the provision of a shopping service cart or the like wherein the main body storage area consists of a front end wall having an inverted U-shaped handle frame with wire mesh extending therebetween, a pair of wire mesh sides, and a generally rectangular insulated, hinged top storage chest at the rear end and also having an inverted U-shaped handle frame attached thereto, and wherein the walls and chest are removably interconnected and mounted on the flat undercarriage for disassembly and flat storage of the these components, as well as the separate use of the undercarriage.
[0005] A further object is to provide a shopping service cart or the like wherein the lanyard fixedly attached thereto has a control unit arranged on the outer end thereof in which the motor controls and wiring are housed with the wiring extending through the lanyard to the battery and dual motors, so that the control unit may either be hand held for actuation by the operator walking in front of the cart or mounted on the rear handle for actuation by the operator from the rear.
[0006] Still another object is the provision of a shopping service cart or the like wherein the battery thereof may be charged by actuation of switching means on the lanyard control unit to close the circuit to the battery and permit manual pushing of the cart in reverse so that no power is transmitted to the rear wheel gear trains and opposite rotation of the driving wheels causes the gears to rotate the motor shafts and act as a charging, direct current generator to produce current and cycle the amperage back into the battery.
[0007] These and other objects and advantages will be apparent as the specification is considered with the accompaying drawings. wherein
[0008] FIG. 1 is perspective view of an assebled cart showing the operator leading and controlling by the hand held control unit on the lanyard.
[0009] FIG. 2 is an exploded perspective of cart with storage components disassembled from the undercarriage thereof;
[0010] FIG. 3 is a front elevation;
[0011] FIG. 4 is a side elevation, showing the lanyard control unit mounted on the rear handle;
[0012] FIG. 5 is a bottom plan view, showing the battery, dual motor, gear and wheel assemblies;
[0013] FIG. 6 is a bottom perspective view of the rear axle and battery assembly;
[0014] FIG. 7 is a perspective view, partly broken away, of the insulated storage chest with top elevated;
[0015] FIG. 8 is a perspective view of the lanyard control unit when mounted on the rear handle;
[0016] FIG. 9 is a plan view of a rear drive wheel with its associated gear box broken away to show a gear train therein;
[0017] FIG. 10 is a diagrammatic view of the control circuit from the lanyard control unit to the battery and dual motors;
[0018] FIG. 11 is an exploded perspective view of a rear driving wheel, and its associated gear box, gear train, and D.C. motor.
DETAILED DESCRIPTION
[0019] Referring more particularly to the drawings, wherein similar reference characters designate like part throughout the several views, the herein and about to be described shopping service cart generally approximates in size, height and shape a conventional basket type shopping cart of the type employed in retail grocery establishments and includes a generally rectangular flat undercarriage 1 having a pair of suitable driving or traction wheels 3 of suitable flow-molded plastic arranged on an aluminum axle 2 suspended and supported beneath the undercarriage 1 adjacent its rear end 4 by suitable brackets 5 . In the interest of reducing weight, the undercarriage 1 may be of a suitable high impact plastic, or aluminum. Supported by posts 6 suitably mounted in and depending from the front corners of the undercarriage 1 are a pair of smaller suitable wheels or casters 7 swivelly mounted, as at 8 , to the lower ends of the posts. A brace rod 9 extends between and serves to retain the posts in position. The rear wheels 3 are larger than the front wheels 7 and, as presently to be described, serve to propel the undercarriage and cart, whereas the smaller wheels, being swively mounted, enable the cart to be steered in an obvious manner.
[0020] Removably supported on the upper surface of undercarriage 1 is a storage compartment 10 which includes a generally rectangular chest 11 having a top 12 hinged, as at 13 , and a suitable latch 14 . The chest may be formed of any suitable material and have an insulated lining, not shown, so that frozen packages and the like may be housed therein. Suitably affixed to a wall of the chest is an inverted U-sghaped tubular aluminum pipe 15 projecting a suitable distance above the top of 12 to provide a rear handle portion 16 . The chest may have suitable trunk handles 17 on the end walls thereof to facilitate handling thereof, and is preferably arranged at one end of the undercarriage 1 , such as the end above the rear drive wheels 3 . Dowel pins 3 may be provided at the lower corners of the chest for interfitting holes 19 in the undercarriage, and suitable latches 20 arranged thereon for securely but removably mounting and anchoring the chest on the undercarriage. Projecting upwardly from, and extending across the front end of the undercarriage is a front panel 21 of aluminum wire mesh 22 or suitable plastic of a height corresponding to that of chest 11 , suitably attached to an inverted U-shaped tubular aluminum pipe 23 projecting a suitable distance above the top 24 of the panel to provide a forward handle portion 25 . Dowel pins or the like 26 on the lower ends of pipe 23 interfit holes 27 in the undercarriage. Side panels 28 - 29 , similar to front panel 21 and extending therefrom to the rear wall 30 of chest 11 , may interfit suitable channels 32 , and the other ends of panels 28 - 29 may be removably attached, in any suitable manner, such as, by latches, not shown, to front panel 21 . The lower ends of the front and side panels may engage with L-shaped angles bars 32 , attached to the upper surface of undercarriage 1 , so as to assist in retaining these components thereon. Thus, it will be evident that the various storage comprtment units are securely, but removably, arranged on the undercarriage, and permit the latter to be used independently thereof when desired, as well as to facilitate storage.
[0021] As best shown in FIGS. 3 , 5 and 11 , the shopping cart and the rear traction wheels 3 thereof are power operated by a pair of relatively small conventional 6-12 volt, D.C. electric motors 33 , suitably mounted on and oppositely projecting inwardly from gear boxes 34 suitably mounted on an supported by rear axle 2 parallel to and adjacent the inner side of each wheel. Referring to FIGS. 9 and 11 , each motor 33 is so positioned that the armature shaft 35 thereof extends through an inner side wall 36 of the gear box and actuates the smallest gear 38 of a train of worm gears 37 . The largest gear 39 thereof is formed with a hub 40 which projects through as outer wall 41 or its gear box and drivingly interengages with a hub 42 of the wheel. Axle 2 projects through the gear boxes and the largest gears 39 thereof and through the wheel hubs 42 , so it will be apparent that the traction wheels 3 will be rotated and driven thereon in an obvious manner.
[0022] A conventional 12 volt storage battery 43 is securely mounted and suspended beneath the undercarriage on a base plate 44 suitable horizontally affixed to the axle 2 and between the supporting brackets 5 thereof so that the battery top abuts the undercarriage and is suitably fixedly so positioned, as best in FIG. 6 . Battery 43 is electrically connected to each of the motors 33 so that when a control unit, presently to be described, is actuated the traction wheels will be driven.
[0023] An important feature hereof is the provision of a remote control operable by the user when walking in front and ahead or astern of the cart and maneuvering and controlling its rate of travel. Thus, an electrical lanyard or cable 45 , of any suitble material, such as, rubber or plastic, which is sufficiently strong and yet flexible to enable the used exerting an appropriate tug thereon when steering of the front wheels or casters 7 , is required and may be suitably securely anchored to the middle of the front brace rod 9 .
[0024] Lanyard 45 is of sufficient length so that a control box 46 on the outer end thereof may be grasped in a hand of the user when walking ahead of the cart, or may be extended rearwardly over the storage compartment 10 , as shown in FIG. 4 , where it may be mounted and supported on the rear handle 16 . A group of conductor wires 47 are encased within the lanyard and extend from within the control box 46 to a point intermediate the ends of the undercarriage where they project from the terminal and of the lanyard and are electrically connected to the posts of the battery 43 and the motors 33 , as shown in the diagram of FIG. 10 .
[0025] The control box 46 is generally rectangular and of a size for grasping and holding in a hand of the user when leading the cart, as in FIG. 1 . A dowel pin 48 projecting from one side wall of the box may be inserted in a hole 49 in rear handle 16 to support the box thereat, as in FIG. 4 , and thereby enable the cart to be controlled from the rear, as will hereinafter be described. Now referring to FIGS. 6 and 10 , suitably arranged in control box 46 are a conventional rheostat 50 , conventional spring loaded push button switch 51 , normally open when released, closed when depressed, conventional double pole double throw cross wire (D.P.D.T.) switch 51 , and conventional blocking diode 53 , which are connected with the conductor wires 47 . It will be noted that the controls for the switches 51 and 52 and the rotatable knob for the rheostat are arranged on the top of the box so as to be available for actuation, whereby switch 51 controls power to the motors 33 , with the circuit to the battery and motors being closed when pressure is applied thereto; rheostat 50 functions to vary the voltage and speed of the motors; and the rotatable knob of the rheostat 50 also functions to hold down the push button switch 51 when this rotatable knob is swung over 51 thus closing the circuit and the D.P.D.T. switch control 52 can be placed in the charging mode D.P.D.T. switch 52 reverses the polarity of the current; and the blocking diode 53 allow current to flow one way to activate motors 33 , blocking the current when the D.P.D.T. switch 52 is reversed thus to stop the current flow from the battery to stop the motors.
[0026] It will be understood that the cart may be readily operated by a walking operator and, by dismantling the storage compartment components from the undercarriage, enable suitable storage thereof, as well as permitting the individual and seperate use of the undercarriage as a truck. The most significant use would be as a shopping service cart, in which event the operator may push the cart, either or without power, to the supermarket and continue pushing it thereat without power until shopping is completed with any frozen food stored in the insulated chest. After checking out and leaving, the operator may stand behind the loaded cart, grasping the rear handle thereof, and, after first pushing the cart to impart movement thereto, actuate the controls on the control box thereon, and guiding under power of the motors so that any terrain may be travelled without effort by the operator, other than steering. The cart may also be controlled and operated with the operator in the lead and the lanyard control box in hand so that the cart trails under power and is steered by tugs on the lanyard. as low gearing trains are arranged in the gear boxes associated with the rear traction wheels, no brake system is required. When being operated under power and an upgrade is encountered, the cart will slow down and then be controlled by the operator. On the other hand, on a downgrade the cart will coast at a very slow rate and is controllable with a little restraint.
[0027] Charging of the storage battery 43 is effected by actuating D.P.D.T. switch 52 to its designated charging position and the rotatable knob of the rheostat control 50 is rotated directly over the push button switch 51 to hold it down and keep the circuit closed, and by the operator pushing the cart in reverse without electric power so that the traction wheels rotate clockwise and similarly rotate the motor shafts 35 through the trains of gearing 37 . Thus the D.C. motors 33 will be driven in reverse of their wired polarity to act as generators producing current cycling the amperage back into and charging the battery. During the charging operation, heat will be dissipated from the armatures and brushes which gives longer life to these components. In the usual electrically operated rider operated vehicles, such as, a power lawn mower or golf cart, a large initial amount of current is required to get the vehicle moving until it can build up needed electrical force or breakway power, which usually is about three times that required to operate the vehicle. On the other hand, it is only necessary for the operator to get the present cart moving a few feet before starting the motors so that breakway power is not needed, and a saving in electrical energy effected.
[0028] While a preferred embodiement of a electrically powered shopping service cart has been shown and described, it is to be understood that various changes and improvements may be made therein without departing from the scope and spirit of the appended claims. | A battery powered, electric motorized cart and burden carrier which may be manually pushed or pulled to a shopping area for use during shopping and for transporting merchandise thereafter. Battery powered motors and gearing associated with the rear driving wheels are controlled from a control box on a lanyard attached to the cart so that the loaded cart may be either operated and controlled by an individual walking in front or the rear thereof. Steering is effected through the swivelly mounted front wheels by the operating exerting a tug on the lanyard or applying forward pressure to the rear of the cart when the control box is arranged and supported thereat. Battery charging may be accomplished by actuating a control box switch to close the circuit to the battery and manually pushing the cart to rotate the motor shafts and cycle the amperage back into the battery. Another way is to utilize an alternating current charging adapter. | 8 |
This is a continuation, of application Ser. No. 06/649,886, filed Sept. 13, 1984, now abondoned.
BACKGROUND OF THE INVENTION
The invention relates to tire building apparatus and particularly to such apparatus which includes an expandable and retractable tire building drum with axially movable bead carrier assemblies positioned at the ends of the drum.
A tire building apparatus as described, for example, in U.S. Pat. No. 4,007,081 comprises a radially expandable cylindrical drum, a pair of axially movable bead carrier assemblies, one at each end of the drum, and fluid actuated means which positively drives or move the carrier assemblies axially toward and away from the ends of the drum. Each of the carriers includes radially outwardly movable bead lock clamps which are also positively driven or moved.
When building a tire on such a tire building apparatus the components of a tire carcass are arranged around the exterior of the drum and carrier assemblies and tire beads are placed over the carcass on each carrier assembly. The bead lock clamps are actuated to move radially outwardly to lock and support the beads in position on the tire carcass. The drum is then expanded radially outwardly while a shaft is rotated by an air actuated clutch to positively move each carrier assembly axially inwardly towards the ends of the drum to allow expansion of the drum. After completion of building the tire (e.g. by placing the belt assembly and tread around the expanded drum), the drum is retracted and the carriers are returned to their original locations when the air actuated clutch rotates the shaft in the opposite direction.
To positively move each carrier assembly axially inwardly toward the ends of the drum or axially outwardly away from the ends of the drum requires separate actuation devices to move each carrier assembly and energy in the form of air pressure to operate such devices.
SUMMARY OF THE INVENTION
It is an object of the present invention to make a tire building apparatus comprising a radially expandable and retractable drum and a pair of axially movable bead carrier assemblies that operate with more energy efficiency and which require less maintenance.
The tire building apparatus of the present invention comprises an expandable and retractable tire building drum and a pair of bead carrier assemblies which are adapted for axial movement to and from the ends of the drum in a more simplified manner. Each bead carrier assembly comprises a bearing means that allows each carrier assembly to react or respond directly to the expansion and retraction of the drum, so that movement of each carrier assembly to and from the drum is achieved without the need for a positive drive or actuation means. A rubber sleeve envelops the drum and the bead carrier assemblies.
In the present invention, the radial expansion and retraction of the drum directly effects axial movement of the bead carrier assemblies. As the drum is expanded outwardly, the bead carrier assemblies are axially pulled towards the drum by the rubber sleeve surrounding the bead carriers and the drum. When retracted, the carriers are pushed axially away from the drum by the rubber sleeve
Each bead carrier assembly comprises a bearing means made up of plurality of shaft enclosures attached to each carrier assembly, and each enclosure is supported on a guide shaft by a plurality of bearings. Each guide shaft is attached to the drum as well as a carrier assembly. The bearing means allows free axial movement of the carrier assembly toward and away from the drum.
As the rubber sleeve expands with the drum expansion, the sleeve axially pulls each bead carrier assembly along the bearing means toward the drum. Each bearing means includes a flange located on the axial inner side of the bearing means to stop the inward movement of each carrier assembly when the flanges abut against the drum, establishing an axial inner position of the bead carrier assemblies.
The tire building apparatus of the present invention is a less complicated structure and, therefore, is less expensive and more maintenance free. Because positive drive for axial movement of the carriers has been eliminated, operation of the apparatus requires less energy. The elimination of separate actuators also reduces possibilities of machine operator error.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view of a tire building apparatus in a retracted condition with parts shown in section, broken away or omitted;
FIG. 2 is an end view taken along the line 2--2 in FIG. 1 of a tire building machine of FIG. 1;
FIG. 3 is an enlarged longitudinal sectional view of a left-hand portion of FIG. 1 showing the apparatus in one expanded condition;
FIG. 4 is an enlarged longitudinal sectional view like that of FIG. 3 with the drum in another expanded condition.
DETAILED DESCRIPTION
In FIG. 1 a tire building apparatus 8 according to the invention is shown in a presently preferred embodiment. The apparatus comprises an expandable and retractable drum 10 shown in a retracted position and a pair of bead carrier assemblies 20 in their axially outermost position away from the drum 10. The drum 10 is symmetrical about a transverse center plane 12 and concentric about a central shaft 14. The pair of bead carrier assemblies 20, one located on each side of the drum 10, are concentric about the central shaft 14. A rubber sleeve 22 covers the drum 10 and both bead carrier assemblies 20 and forms the building surface of the apparatus 8.
The drum 10 is supported on the central shaft 14 by a table 42. The table 42 is bolted to one end face 15 of an enlarged portion of the central shaft 14 as shown in FIG. 1. Mounted on each end of the table 42 is a cylindrical sleeve 41 capable of sliding axially inwardly or axially outwardly on a recessed portion 45 of the table 42. The pair of cylindrical sleeves 41 can be axially adjusted to accommodate various tire sizes by an adjustment mechanism 43. The adjustment mechanism 43 comprises a rod 58 with threads 60 on each end. The rod 58 is threaded through extensions 47 of the cylindrical sleeves 41. The rotation of the rod 58 will move the sleeves 41 inwardly toward the drum 10 or outwardly away from the drum 10.
An annular drum guide 37 is welded or otherwise secured to each cylindrical sleeve 41. Attachments to each annular drum guide 37 are similar and the attachments to one guide 37 will be described herein. Bolted or otherwise secured to each guide 37 is a cylindrical bladder support 39 that functions as a support for a drum bladder 38. Each drum bladder 38 is inflated from a fluid source (not shown) through fluid inlets 101. Mounted on each guide 37 is a plurality of annularly spaced drum surface members 36. Bolted perpendicularly to each drum surface members 36 is an annular guide ring 33. The guide ring 33 positions each surface member 36 relative to the annular drum guide 37.
A plurality of spacers 50 is located on the drum surface members 36 to allow for axial adjustment of the drum 10. Each spacer 50 has two ends 51 and 52. The one end 51 of the spacer 50 is secured to one of the drum surface members 36. The other end 52 of the spacer 50 overlaps an axially corresponding drum surface member 36.
The drum 10 expands and retracts when the two bladders 38 are inflated or deflated. When a bladder 38 is inflated as shown in FIG. 4, the bladder 38 pushes the plurality of drum surface members 36 radially outwardly. Each drum surface member 36 is guided by the guide 37 and the cylindrical bladder support 39. The radially outward movement of the drum surface members 36 is limited when a lip 80 of each drum surface members 36 contacts lip 82 of each annular drum guide 37 and a lip 84 of each annular guide ring 33 contacts the lip 86 of each cylindrical bladder support 39. When the bladders 38 deflate, the drum surface members 36 retract radially inwardly to their original position by the tension of the rubber sleeve 22.
In accordance with this invention, the tire building apparatus further includes a pair of bead carrier assemblies 20 that can move axially to and from the drum 10 without the need for a positive drive device or mechanism. Each of the bead carrier assemblies 20 are similar and only one need be described in detail herein.
Each bead carrier assembly 20 comprises a floating segment holder 64, a bearing means 27 and a plurality of bead locating segments or clamps 54. A partial end view of the floating segment holder 64 is shown in FIG. 2. The floating segment holder 64 serves as a holder for both the bearing means 27 and the plurality of bead locating segments 54. In addition, the floating segment holder 64 is adapted to move or "float" on the bearing means 27 axially towards the drum 10 and axially away from the drum 10.
As seen in FIGS. 2 and 3, each floating segment holder 64 comprises an annular plate 88 with an annular bearing support ring 90 attached thereto. The annular ring 90 of each floating segment holder 64 further has bearing means support bores 25 and a peripheral surface 65. Also attached to the annular plate 88 are eight arms 92 extending outwardly. One arm 92 is shown in FIG. 3. Attached to each arm 92 by a pin 78 is a bead locating segment 54.
An annular bladder 44 is disposed axially inwardly of the annular plate 88 of each floating segment holder 64. A fluid inlet 94 registers through the annular plate 88 into the bead bladder 44. The inlet 94 conveys air to the bladder 44 from a fluid source (not shown) for inflation of the bladder 44 and exhausts air from the bladder 44 for deflation of the bladder 44. The fluid inlet 94 also serves to hold the bladder 44 in place.
Each bearing means 27 comprises guide shaft enclosures 30. Each enclosure 30 is held in a corresponding bore 25 by conventional means such as setscrews. Each guide shaft enclosure 30 surrounds a guide shaft 28. Located between each guide shaft enclosure 30 and the corresponding guide shaft 28 is a plurality of ball bearings 32. Bearing means such as 27 comprising the guide shaft enclosures 30 guide shafts 28, and pluralities of bearings 32 are often referred to as linear bearings.
The four guide shafts 28 of bearing means 27 are individually attached to both the drum 10 and the bead carrier assembly 20. FIG. 3 shows one such guide shaft having an inner end 29 against the drum 10 and an outer end 31 adjacent a bead carrier assembly 20. Inner end 29 of guide shaft 28 is bolted through an annular drum guide 37 by a bolt 62 threaded into end 29 of the guide shaft 28. Outer end 31 of each guide shaft 28 is bolted to a radial flange 100 on the cylindrical sleeve 41 by another bolt 62 threaded into the outer end 31 of the guide shaft 28.
Attached to each bore 25 is a flange 34. The flanges 34 serve to stop inward axial movement of each bead carrier assembly 20 when the flange 34 about the annular drum guide 37. Each peripheral surface 65 of ring 90 supports a cylindrical floating sleeve 66. The sleeve 66 has a recessed portion 71 along its smooth outer surface 69.
Mounted on the smooth surface 69 of sleeve 66 is a L-shaped annular support 56. Mounted on the support 56 are eight bead locking segments 54.
The support 56 is slidable on surface 69 of sleeve 66 and has a radially projecting plate 57. The annular bladder 44 is in operative contact with the plate 57.
The slidable support 56 is connected to a bead locating segment 54 by a pivot arm 70. Each pivot arm 70 is attached to the support 56 by a pin 72 attaching the pivot arm 70 to a mounting bracket 68 on the support 56. In addition, each pivot arm 70 is attached to a bead locating segment 54 by another pin 74 attaching the pivot arm 70 to a mounting bracket 76 on the segment 54. Each segment 54 is attached to a corresponding arm 92 of each floating segment holder 64 by another pin 78.
With the above-described configuration of each bead carrier assembly 20, when the annular bladder 44 is inflated to push the support 56 towards the drum 10 as indicated by arrow B, pivot arm 70 mounted onto the support 56 and the segment 54 cause outward radial movement of the bead segment 54 as indicated by arrow A in FIG. 3.
Building a tire on apparatus 8 begins by placing the tire carcass 24 over the rubber sleeve 22. The carcass 24 usually comprises one or more plies of cord reinforced rubber material. The carcass may be reinforced by any one of the known fabric reinforcement materials or may be fiberglass or metal. After the carcass 24 is built, two beads 48 are set into place, one at each end of the carcass 24 and radially outwardly of the bead locating segments 54 by a pair of bead setters 26 each located at each outer end of the bead carrier assemblies 20.
In FIG. 3 there is shown a sectional view of the tire building apparatus with the annular bladder 44 inflated causing the support 56 to slide through pivot arm 70 to move the bead locating segments 54 radially outwardly to clamp the bead 48 and to clamp the tire carcass 24 between the bead 48 and the segments 54.
The next step in the tire building process involves the expansion of the drum 10 as shown by arrow C in the sectional view of the tire building apparatus 8 in FIG. 4. The drum bladders 38 are inflated causing radially outward movement of the drum surface members 36 along the bladder support 39. This causes the rubber sleeve 22 and the tire carcass 24 thereon to expand radially outwardly. As the drum 10 expands radially outwardly, the rubber sleeve 22 pulls each bead carrier assembly 20 towards the drum 10 until the flanges 34 contact the annular drum guide 37. The clamped tire carcass 24 aids the rubber sleeve 22 in pulling each carrier assembly 20 toward the drum 10. The expanded drum bladders 38 will secure the tire carcass 24 and the beads 48 in this expanded position. At this stage, in a conventional manner, the beads 48 are enclosed by turning ends 18 and 19 of the tire carcass 24 axially over the beads 48.
When the tire carcas 24 is ready for removal from the tire building apparatus 8, the drum bladders 38 and the bladders 44 are deflated. The deflation of the drum bladders 38 cause the drum surface members 36 and ruber sleeve 22 to retract radially inwardly. The retraction of the rubber sleeve 22 pushes the bead carrier assemblies 20 axially outwardly, away from the drum 10. The deflation of the bladders 44 cause the supports 56 to move axially outwardly away from the drum 10 and the bead segments 54 to collapse radially inwardly as shown in the collapsed version of FIG. 1. At this time the tire carcass 24 can be removed from the tire building apparatus 8.
While there has been shown and described a preferred embodiment of the presetn invention, it will be understood by those skilled in the art that various rearrangements and modifications be made therein without departing from the scope of the invention which is to be measured by the accompanying claims. | A tire building machine that allows for free axial movement of positioned beads towards a tire drum during expansion of the tire drum. The axial movement of the bead is effected by a rubber sleeve that envelops the tire drum and a pair of bead carrier assemblies, each one located axially outwardly of the drum. Subsequent to positioning the bead in a tire building process, the beads are locked into place by means attached to each of the bead carrier assemblies. Expansion of the drum causes the sleeve to effect inwardly axial movement of the bead carrier assemblies toward the drum carrying the tire beads towards the drum, and retraction of the drum causes outwardly axial movement of the bead carrier assemblies away from the drum. | 1 |
BACKGROUND
[0001] 1. Field
[0002] The present invention relates to a method, system, and an article of manufacture for validating a remote device.
[0003] 2. Description of the Related Art
[0004] Fibre channel networks may be used in storage area networking (SAN) environments to attach servers and storage. In certain implementations, fibre channel networks may also be used to allow for peer-to-peer connections between storage devices. Fiber channel networks may be classified into a variety of topologies. In a point-to-point topology, each pair of network components are connected via dedicated links. In an arbitrated loop topology, groups of network components are connected via a loop. In a switched fabric topology, network components are connected via switches. Errors may occur in a switched fabric network for various reasons. For example, cables may be unplugged temporarily in the switched fabric, or cables may be accidentally swapped resulting in misdirected data in the network.
[0005] Certain networked information technology systems, including storage systems, may need protection from site disasters or outages. Implementations for protecting from site disasters or outages may include mirroring or copying of data in storage systems. Such mirroring or copying of data may involve interactions among hosts, storage systems and connecting networking components of the information technology system.
[0006] An enterprise storage server* (ESS) may be a disk storage server that includes one or more processors coupled to storage devices, including high capacity scalable storage devices, Redundant Array of Independent Disks (RAID), etc. The enterprise storage servers may be connected to a network, such as a fibre channel network, and include features for copying data in storage systems. Peer-to-Peer Remote Copy (PPRC) Enterprise Storage Server (ESS) is a trademark of International Business Machines Corp. is an ESS copy function that allows the shadowing of application system data from a first site to a second site. The first site may be referred to as an application site, a local site, or a primary site. The second site may be referred to as a recovery site, a remote site, or a secondary site. In certain implementations, the first and second site may be coupled via fibre channel networks that includes switches.
SUMMARY OF THE PREFERRED EMBODIMENTS
[0007] Provided are a method, system, and article of manufacture, wherein in certain embodiments a first device determines a possibility of an invalidation of a second device, wherein the first device is coupled to the second device via a fabric. A query is sent from the first device to validate the second device, in response to determining the possibility of the invalidation of the second device. A determination is made, at the first device, whether to continue I/O operations from the first device to the second device based on receiving a response to the query within a time period.
[0008] In additional embodiments, determining, by the first device, the possibility of the invalidation of the second device, further comprises determining whether the first device has received either a notification of a state change from the fabric or has timed out while waiting for a completion of an I/O operation sent from the first device to the second device.
[0009] In yet additional embodiments, sending the query further comprises sending a service frame from the first device to the second device, wherein the service frame is capable of determining a presence of the second device without disrupting the I/O operations. In further embodiments, the service frame is a PDISC Extended Link Service frame.
[0010] In further embodiments, the I/O operations are continued, if the response to the query within the time period is a frame that validates the World Wide Node Name and the World Wide Port name associated with a connection to the second device. In further embodiments, the frame is an LS_ACC frame.
[0011] In yet further embodiments, a connection is terminated from the first device to the second device, if the response to the query is not received within the time period or if the response is a frame that indicates that the second device does not consider the first device to be logged in to the second device. In further embodiments, the frame is a LOGO frame or a LS_RJT frame.
[0012] In additional embodiments, the query is received at the second device, prior to determining, at the first device, whether to continue I/O operations from the first device to the second device. A determination is made, at the second device, whether the first device is a valid initiator to the second device. The response is sent from the second device, wherein the response indicates that the second device does not consider the first device to be logged in to the second device, in response to determining that the first device is not the valid initiator to the second device.
[0013] In yet additional embodiments, the query is received at the second device, prior to determining, at the first device, whether to continue I/O operations from the first device to the second device. A determination is made at the second device, whether the first device is considered to be logged in to the second device. The response is sent from the second device, wherein the response indicates that the second device considers the first device to be logged in to the second device, in response to determining that the first device is considered to be logged in to the second device.
[0014] In still further embodiments, the query is received at the second device, prior to determining, at the first device, whether to continue I/O operations from the first device to the second device. A determination is made, at the second device, whether the first device is considered to be logged in to the second device. The response is sent from the second device, wherein the response indicates that the second device does not consider the first device to be logged in to the second device, in response to determining that the first device is not considered to be logged in to the second device.
[0015] In additional embodiments, the first and second devices are fibre channel adapters coupled to primary and secondary storage controllers respectively, wherein the fabric is a switched fabric, and wherein the fibre channel adapters communicate using extended link services commands.
[0016] In certain embodiments implemented in a fibre channel PPRC environment, a PPRC primary device, such as, a primary storage control unit, may determine, via positive identification of a secondary storage control unit, whether a login is actually required to the secondary storage control unit because of a state change in a fibre channel network. As a result of the positive identification of the secondary storage control unit repeated disruptive logins to the secondary storage control unit may not be required in the embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Referring now to the drawings in which like reference numbers represent corresponding parts throughout:
[0018] FIG. 1 illustrates a block diagram of a computing environment, in accordance with certain described aspects of the invention;
[0019] FIG. 2 illustrates a block diagram of data structures implemented in a storage control unit and a fibre channel adapter, in accordance with certain described implementations of the invention;
[0020] FIG. 3 illustrates a block diagram of communications between two fibre channel adapters, in accordance with certain described implementations of the invention;
[0021] FIG. 4 illustrates logic implemented in a primary fibre channel adapter, in accordance with certain described implementations of the invention;
[0022] FIG. 5 illustrates logic implemented in a secondary fibre channel adapter, in accordance with certain described implementations of the invention; and
[0023] FIG. 6 illustrates a block diagram of a computer architecture in which certain described aspects of the invention are implemented.
DETAILED DESCRIPTION
[0024] In the following description, reference is made to the accompanying drawings which form a part hereof and which illustrate several implementations. It is understood that other implementations may be utilized and structural and operational changes may be made without departing from the scope of the present implementations.
Disruptive Logins in Remote Date Transfer
[0025] If a connection for remote data transfer over a fibre channel storage area network (SAN) exists, the primary storage controller may determine via an external notification or through an internal error detection, that a state change has occurred in the SAN or in the secondary storage controller. The primary storage controller may have to validate the identity of the secondary storage controller. To validate the identity of the secondary storage controller, the primary storage controller may try to log into the secondary storage controller once again. However, the login operation to the secondary storage controller may be disruptive to the secondary storage controller. Logging in too often, i.e., whenever a state change may have occurred, may have a negative impact on ongoing input/output (I/O) operations if the state change does not actually require the login. Waiting too long before trying to login in can cause a permanent I/O failure if the login should have been performed.
[0026] Certain embodiments of the invention allow a primary storage controller to determine through validation of the secondary storage controller, if a login is actually required to the secondary storage controller. Certain embodiments of the invention are non-disruptive to any I/O in progress, in case a login is not required.
Validating a Remote Device
[0027] FIG. 1 illustrates a block diagram of a computing environment 100 , in accordance with certain described aspects of the invention. A host 101 is coupled to a storage unit, such as, a primary storage control unit 102 , where the host 102 may sent input/output (I/O) requests to the primary storage control unit 102 . The primary storage control unit 102 may send the I/O requests to one or more other storage units, such as, secondary storage control units 104 , 106 . The storage control units 104 , 106 may also be referred to as storage controllers. Although only two secondary storage control units 104 , 106 are shown, certain embodiments may include a greater or a fewer number of secondary storage control units. Furthermore, while only a single host 101 is shown coupled to the primary storage control unit 102 , in other embodiments a plurality of hosts may be coupled to the primary storage control unit 102 . The host 101 may be any computational device known in the art, such as a personal computer, a workstation, a server, a mainframe, a hand held computer, a palm top computer, a telephony device, network appliance, etc.
[0028] In certain embodiments, the primary storage control unit 102 and the secondary storage control units 104 , 106 are coupled by a fibre channel data interface mechanism. In other embodiments, different data interface mechanisms may be used to couple the primary storage control unit 102 to the secondary storage control units 104 , 106 .
[0029] The storage control units 102 , 104 , 106 may each include one or more storage subsystems (not shown). In certain embodiments, the storage subsystems may be computational devices that include storage volumes (not shown) configured as a Direct Access Storage Device (DASD), one or more RAID ranks, Just a bunch of disks (JBOD), or any other data repository system known in the art.
[0030] In certain embodiments, the storage control units 102 , 104 , 106 are coupled to one or more fibre channel adapters. For example, the primary storage control unit 102 may be coupled to fibre channel adapters 108 a . . . 108 q, the secondary storage control unit 104 may be coupled to fibre channel adapters 110 a . . . 110 r, and the secondary storage control unit 106 may be coupled to fibre channel adapters 112 a . . . 112 s.
[0031] In some embodiments, a fabric, such as, a switched fabric, may couple a first fibre channel adapter coupled to the primary storage control unit 102 , to a second fibre channel adapter coupled to a secondary storage control unit 104 , 106 . For example, a switched fabric 114 couples the fibre channel adapter 108 a that is coupled to the primary storage control unit 102 , to the fibre channel adapter 110 a that is coupled to the secondary storage control unit 104 . Additionally, a switched fabric 116 may couple the fibre channel adapter 108 q that is coupled to the primary storage control unit 102 , to the fibre channel adapter 112 b that is coupled to the secondary storage control unit 106 . Therefore, in certain embodiments the primary storage control unit 102 may communicate with the secondary storage control units 104 , 106 via fibre channel adapters 108 a . . . 108 q, 110 a . . . 110 r, 112 a . . . 112 s and the switched fabrics 1114 , 116 .
[0032] In certain embodiments, the switched fabrics 114 , 116 may include one or more switches. For example, switched fabric 114 includes switches 118 and 120 , where the switches 118 and 120 are interconnected via a cable 122 . Switched fabric 116 may include switches 124 and 126 , where the switches 124 and 126 are interconnected via a cable 128 .
[0033] State changes may occur in the computing environment 100 for a variety of reasons. For example, in certain embodiments the primary storage control unit 102 sends an I/O command to the secondary storage control unit 104 via the fibre channel adapter 108 a, the switch 118 , the cable 122 , the switch 120 , and the fibre channel adapter 110 a. In certain situations, the cable 122 may be accidentally disconnected from switch 120 and may be connected to switch 128 and a state change may occur in the computing environment 100 . In such a situation I/O commands sent by the primary storage control unit 102 , where the I/O commands are intended for the secondary storage control 104 , may be misdirected to the secondary storage control 106 . If the secondary storage control 106 executes the misdirected I/O commands then data in the secondary storage control 106 may not be consistent with data in the primary storage control unit 102 . Therefore, it may be sometimes be desirable to terminate certain connections in the computing environment 100 when certain state changes is detected. State changes may also occur for various other reasons in the computing environment 100 , such as, swapping or disconnection of other cables, changes in configuration of switches, etc. In certain embodiments, the switched fabric 114 may notify the fibre channel adapter 108 a of the state change. In other embodiments, the swapping of the cables 122 , 128 may cause a timeout of an I/O operation occurring between the primary storage control unit 102 and the secondary storage control unit 104 .
[0034] If the fibre channel adapter 108 a detects either by an external notification or via internal error detection that a state change has occurred in the computing environment 100 , either in the switched fabric 114 or in the fibre channel adapter coupled to the secondary storage control unit 104 , then in embodiments of the invention the fibre channel adapter 108 a may have to positively validate the identity of the secondary storage control unit 104 to which the fibre channel adapter 108 a is coupled.
[0035] While the fibre channel adapter 108 a may attempt to perform a login to the secondary storage control unit 104 to positively identify the secondary storage control unit 104 , repeated logins to the secondary storage control unit 104 may be disruptive to ongoing I/O operations of the primary storage control unit 102 to the secondary storage control unit 104 . However, if the fibre channel adapter 108 a waited too long to perform a login to the secondary storage control unit 104 , then failure may occur for an ongoing I/O operation between the primary storage control unit 102 and the secondary storage control unit 104 .
[0036] In certain embodiments of the invention, the fibre channel adapter 108 a may send a PDISC Extended link service frame that is directed at the fibre channel adapter 110 a to determine the presence of the secondary.
[0037] Therefore, FIG. 1 , illustrates a computing environment 100 in which a fibre channel adapter 108 a coupled to a primary storage control unit 102 sends a PDISC Extended Link Service frame to determine the presence of the secondary storage control unit 104 . The PDISC Extended Link Service frame is non-disruptive to I/O operations occurring between the primary storage control unit 102 and the secondary storage control unit 104 .
[0038] FIG. 2 illustrates a block diagram of data structures implemented in the storage control units 102 , 104 , 106 and the fibre channel adapters 108 a . . . 108 q, 110 a . . . 110 r, 112 a . . . 112 s in accordance with certain described implementations of the invention.
[0039] A storage control unit 200 , where the storage control unit 200 may be any of the storage control units 102 , 104 , 106 , may include a data structure that corresponds to a World Wide Node Name (WWNN) 202 , where the WWNN 202 is an identification of the storage control unit 200 .
[0040] A fibre channel adapter 204 , where the fibre channel adapter 204 may be any of the fibre channel adapters 108 a . . . 108 q, 110 a . . . 110 r, 112 a . . . 112 s may include a port 206 . The fibre channel adapter 204 may communicate with another fibre channel adapter via a fibre channel link established between port 206 and a corresponding port in the another fibre channel adapter. Although, the fibre channel adapter 204 is shown with only one port 206 , in alternative embodiments the fibre channel adapter may have a plurality of ports.
[0041] The fibre channel adapter 204 includes a World Wide Port Name (WWPN) 208 that is an identification of the port 206 the fibre channel adapter 204 . The fibre channel adapter 204 may also include a WWNN 210 that corresponds to the WWNN 202 of the storage control unit to which the fibre channel adapter is coupled. For example, fibre channel adapter 108 a may include the WWNN of the primary storage control unit 102 , and fibre channel adapter 110 a may include the WWNN of the secondary storage control unit 104 .
[0042] The fibre channel adapter 204 may also include capabilities to generate a PDISC Extended Link Service frame 212 , a LS_ACC frame 214 , a LOGO frame and a LS_RJT frame 218 . The generated frames 212 , 214 , 216 , 218 may be sent from one fibre channel port to another fibre channel port.
[0043] The PDISC Extended Link Service frame 212 , also referred to as a PDISC frame provides a method for two fibre channel ports to exchange operating parameters without disrupting I/O operations on either of the two fibre channel ports. In certain embodiments, a first fibre channel port may send a PDISC frame 212 to a second fibre channel port. In response to receiving the PDISC frame 212 at the second fibre channel port, the second fibre channel port may respond with a LS_ACC frame 214 to indicate that the second fibre channel port considers the first fibre channel port to be logged in to the second fibre channel port. In response to receiving the PDISC frame 212 at the second fibre channel port, the second fibre channel port may respond with a LOGO frame 216 or a LS_RJT frame 218 to indicate that the second fibre channel port does not consider the first fibre channel port to be logged in to the second fibre channel port.
[0044] In certain embodiments, in response to the primary storage control unit 102 executing instructions to send I/O commands to the secondary storage control unit 104 , the primary storage control unit 102 may request the switch 118 (via the fibre channel adapter 108 a ) to return a destination ID (not shown) of the secondary storage control unit 104 by supplying the WWPN 208 of the fibre channel port corresponding to the fibre channel adapter 110 a, to the switch 118 . In certain embodiments, the switch 118 may, in conjunction with nameservers implemented in the switched fabric 114 , return the destination ID of the secondary storage control unit 104 . The primary storage control unit 102 may login to the secondary storage control unit 104 by using the destination ID. After logging in, the primary storage control unit 102 may send I/O commands to the secondary storage control unit 104 .
[0045] The destination ID of a secondary storage control unit may not always be unique. For example, in certain embodiments the secondary storage control unit 104 may be referred to with the destination address of one in the switched fabric 114 , and the secondary storage control unit 106 may also be referred to with the destination address of one in the switched fabric 116 . In such a situation, if the cable 122 is disconnected from switch 122 and connected to switch 126 , after the primary storage control unit 102 has started sending I/O commands to the secondary storage control unit 104 by using the destination ID of one, then the primary storage control unit 102 would be misdirecting the I/O commands to the secondary storage control unit 106 via the switched fabric 116 because the destination ID of one appears to the switched fabric 116 as the secondary storage control unit 106 . If the secondary storage control unit 106 executes the received I/O commands, then data in the secondary storage control unit 106 may not be consistent with the primary storage control unit 104 . In certain embodiments of the invention, a PDISC frame 212 sent from the fibre channel adapter 108 a may perform a non-disruptive validation of the secondary storage control unit, such that, the primary storage control unit 102 can attempt to login in once again to the correct secondary storage control unit in case of a change in the state of the switched fabric 114 .
[0046] Therefore, FIG. 2 illustrates embodiments in which a PDISC frame 212 is used to validate the identity of the secondary storage control unit 104 .
[0047] FIG. 3 illustrates a block diagram of communications between two fibre channel adapters 108 a, 110 a, in accordance with certain implementations of the invention.
[0048] The first fibre channel adapter 108 a that is coupled to the first storage control unit 102 , may include a first port 300 that communicates with the switched fabric 114 . The second fibre channel adapter 110 a that is coupled to the second storage control unit 104 may include a second port 302 that also communicates with the switched fabric 114 .
[0049] In addition to the first port 300 , the first fibre channel adapter includes a WWPN 304 corresponding to the first port 300 and a WWNN 306 corresponding to the first storage control unit 102 . Also, in addition to the second port 302 , the second fibre channel adapter 110 a includes a WWPN 308 corresponding to the second port 302 and a WWNN 310 corresponding to the second storage control unit 104 .
[0050] In certain embodiments, a first application 312 coupled to the first port 300 sends a PDISC frame 212 to the second port 302 to validate the identity of the second storage control unit 104 . In response to receiving the PDISC frame 212 across the switched fabric 114 , a second application 314 coupled to the second port 302 may determine and send a response 316 to the first port 300 .
[0051] Therefore, FIG. 3 describes an embodiment in which the first port 300 sends a PDISC frame 212 to the second port 302 and receives a response 316 . In certain embodiments, the first port 300 may not receive a response in a certain amount of time and may assume that no response is likely to be received from the second port 302 .
[0052] FIG. 4 illustrates logic implemented in the first fibre channel adapter 108 a, where the first fibre channel adapter 108 a may be a primary fibre channel adapter coupled to the primary storage control unit 102 , in accordance with certain implementations of the invention. In certain embodiments, the logic may be executed by the first application 312 implemented in the first fibre channel adapter 108 a.
[0053] Control starts at block 400 where the first fibre channel adapter 108 a sends an I/O operation to the second fibre channel adapter 110 a. The first fibre channel adapter 108 a determines (at block 402 ) whether the first fibre channel adapter 108 a has received a a notification of a state change from the switched fabric 114 or has encountered a timeout while waiting for an I/O operation to complete. If no notification of a state change has been received and no timeout has been encountered, the first fibre channel adapter 108 a sends (at block 400 ) another I/O operation to the second fibre channel adapter 110 a.
[0054] If the first fibre channel adapter 108 a determines (at block 402 ) that the first fibre channel adapter 108 a has received a notification of a state change from the switched fabric 114 or has encountered a timeout while waiting for an I/O operation to complete, then the first fibre channel adapter 108 sends (at block 404 ) a PDISC frame 212 directed at the second fibre channel adapter 110 a to determine the presence of the second fibre channel adapter 110 a. Therefore, in the implementations the PDISC frame 212 is sent in response to a notification of a state change of the switched fabric 114 or a timeout while waiting for an I/O command to complete.
[0055] The first fibre channel adapter 108 a determines (at block 406 ) if the response 316 has been received in response to the sent PDISC frame 212 within a certain amount of time. The response 316 that may be received by the first fibre channel adapter 108 a may be generated by the second fibre channel adapter 110 a on receiving the PDISC frame 212 . The PDISC frame 212 does not disrupt I/O operations that occur between the first and second fibre channel adapters 108 a, 110 a.
[0056] If the first fibre channel adapter 108 a determines (at block 406 ) that a response 316 has not been received in response to the sent PDISC frame 212 within a certain amount of time, then the first fibre channel adapter 108 a terminates (at block 408 ) the logged-in status of the first storage control unit 102 to the second storage control unit 104 , aborts all open tasks, and attempts to reestablish a path between the first storage control unit 102 and the second storage control unit 104 .
[0057] If the first fibre channel adapter 108 a determines (at block 406 ) that the response 316 has been received in response to the sent PDISC frame 212 within a certain amount of time, then the first fibre channel adapter 108 a determines (at block 410 ) the type of response 316 received at the first fibre channel adapter 108 a.
[0058] If the determined response 316 (at block 410 ) is an LS_ACC frame 214 then the first fibre channel adapter 108 a determines (at block 412 ) if the WWPN and the WWNN included in the LS_ACC frame 214 validates the identity of the second storage control unit 104 . The LS_ACC frame 214 validates the identity of the second storage control unit 104 if the WWPN and the WWNN included in the LS_ACC frame is the same as the WWPN 308 and the WWNN 310 respectively, that are included in the second fibre channel adapter 110 a.
[0059] If the first fibre channel adapter 108 a determines (at block 412 ) that the identity of the second storage control unit 104 is validated, then the first fibre channel adapter 108 a continues (at block 414 ) operations without interruptions. If the first fibre channel adapter 108 a determines (at block 412 ) that the identity of the second storage control unit 104 is not validated, then the first fibre channel adapter 108 a terminates (at block 408 ) the logged-in status of the first storage control unit 102 to the second storage control unit 104 , aborts all open tasks, and attempts to reestablish a path between the first storage control unit 102 and the second storage control unit 104 .
[0060] If the determined response 316 (at block 410 ) is a LOGO frame 216 or an LS_RJT frame 218 or some other response 416 then the first fibre channel adapter 108 a terminates (at block 408 ) the logged-in status of the first storage control unit 102 to the second storage control unit 104 , aborts all open tasks, and attempts to reestablish a path between the first storage control unit 102 and the second storage control unit 104 .
[0061] Therefore, FIG. 4 illustrates certain embodiments in which the first fibre channel adapter 108 a sends a non-disruptive PDISC frame 212 to a second fibre channel adapter 110 a to validate the second fibre channel adapter 110 a. In certain embodiments, the first fibre channel adapter 108 a may be a primary fibre channel adapter and the second fibre channel adapter 110 a may be a secondary fibre channel adapter and the logic may be implemented in the first application 312 that may be coupled to the first fibre channel adapter 108 a.
[0062] FIG. 5 illustrates logic that may be implemented in the second fibre channel adapter 110 a, where the second fibre channel adapter 110 a may be a secondary fibre channel adapter coupled to the secondary storage control unit 104 , in accordance with certain implementations of the invention. In certain embodiments, the logic may be executed by the second application 314 implemented in the second fibre channel adapter 110 a.
[0063] Control starts at block 500 , where the second fibre channel adapter 110 a receives the PDISC frame 212 sent (at block 404 ) by the first fibre channel adapter 108 a. The second fibre channel adapter 110 a determines (at block 502 ) if an initiator with the same port address but different WWPN or WWNN when compared to the sender of the PDISC frame 212 is in a logged in state to the second fibre channel adapter 110 a (in certain embodiments the initiator may be a different fibre channel adapter than the first fibre channel adapter 108 a that sent the PDISC frame 212 ). If so, the second fibre channel adapter 110 a aborts (at block 504 ) all open tasks for that initiator, internally logs out the sender of the PDISC, and responds to the PDISC with a LOGO frame 216 . Therefore, the embodiments identify potential errors in the computing environment 100 involving different WWPN or WWNN corresponding to the same port address.
[0064] If the second fibre channel adapter 110 a determines (at block 502 ) that an initiator with the same port address but different WWPN or WWNN when compared to the sender of the PDISC frame 212 is not in a logged in state to the second fibre channel adapter 110 a, then the second fibre channel adapter 110 a determines (at block 506 ) if the sender of the PDISC frame is considered to be logged in by the second fibre channel adapter 110 a. If so, then the second fibre channel adapter 110 a accepts the PDISC frame 212 and sends an LS_ACC frame 214 , indicating that the second fibre channel adapter 110 a considers the sender to be logged in, where the LS_ACC frame 214 includes the second fibre channel adapter's 110 a WWNN 310 and WWPN 308 . If not, then the second fibre channel adapter 110 a sends a LS_RJT frame 218 or a LOGO frame 216 or some other response 416 , including an indication that the second fibre channel adapter does not consider the sender to be logged in. The responses sent (at blocks 508 , 510 ) by the second fibre channel adapter 110 a may be processed (at blocks 406 , 410 , 412 ) by the first fibre channel adapter 108 a.
[0065] Therefore, FIG. 5 describes an embodiment in which the second fibre channel adapter 110 a responds to a PDISC frame 212 sent by the first fibre channel adapter 108 . In certain embodiments, the first fibre channel adapter 108 a may be a primary fibre channel adapter and the second fibre channel adapter 110 a may be a secondary fibre channel adapter and the logic may be implemented in the second application 314 that may be coupled to the second fibre channel adapter 110 a.
[0066] The embodiments have been described with one port per fibre channel adapter. In alternative implementations, a single fibre channel adapter with one or more ports may perform data transfer from one plurality of storage control units to another plurality of storage control units. While frames have been used in the embodiments, alternative embodiments may use other data transmission units besides frames. Furthermore, the embodiments may also be implemented in networks that are not based on fibre channel. Additionally, in alternative implementations the first and second applications 312 , 314 may be implemented in the storage control units 102 , 104 and control the operations of the fibre channel adapters 108 a, 110 a.
[0067] In certain additional embodiments implemented in a fibre channel PPRC environment, a PPRC primary device, such as the primary storage control unit 102 , may determine, via positive identification of a secondary storage control unit 104 , whether a login is actually required to the secondary storage control unit 104 because of a state change in a fibre channel network. As a result of the positive identification of the secondary storage control unit 104 , repeated disruptive logins to the secondary storage control unit 104 are not required in the embodiments.
Additional Implementation Details
[0068] The described techniques may be implemented as a method, apparatus or article of manufacture using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof. The term “article of manufacture” as used herein refers to code or logic implemented in hardware logic (e.g., an integrated circuit chip, Programmable Gate Array (PGA), Application Specific Integrated Circuit (ASIC), etc.) or a computer readable medium (e.g., magnetic storage medium, such as hard disk drives, floppy disks, tape), optical storage (e.g., CD-ROMs, optical disks, etc.), volatile and non-volatile memory devices (e.g., EEPROMs, ROMs, PROMs, RAMs, DRAMs, SRAMs, firmware, programmable logic, etc.). Code in the computer readable medium is accessed and executed by a processor. The code in which implementations are made may further be accessible through a transmission media or from a file server over a network. In such cases, the article of manufacture in which the code is implemented may comprise a transmission media, such as a network transmission line, wireless transmission media, signals propagating through space, radio waves, infrared signals, etc. Of course, those skilled in the art will recognize that many modifications may be made to this configuration without departing from the scope of the implementations, and that the article of manufacture may comprise any information bearing medium known in the art.
[0069] FIG. 6 illustrates a block diagram of a computer architecture in which certain aspects of the invention are implemented. FIG. 6 illustrates one implementation of the host 101 , and the storage control units 102 , 104 , 106 , and the fibre channel adapters 108 a . . . 108 q, 110 a . . . 110 r, 112 a . . . 112 s. Not all elements illustrated in FIG. 6 are required to be present in the host 101 , the storage control units 102 , 104 , 106 , and the fibre channel adapters 108 a . . . 108 q, 110 a . . . 110 r, 112 a . . . 112 s. The host 101 , the storage control units 102 , 104 , 106 , and the fibre channel adapters 108 a . . . 108 q, 110 a . . . 110 r, 112 a . . . 112 s may implement a computer architecture 600 having a processor 602 , a memory 604 (e.g., a volatile memory device), and storage 606 (e.g., a non-volatile storage, magnetic disk drives, optical disk drives, tape drives, etc.). The storage 606 may comprise an internal storage device, an attached storage device or a network accessible storage device. Programs in the storage 606 may be loaded into the memory 604 and executed by the processor 602 in a manner known in the art. The architecture may further include a network card 608 to enable communication with a network. The architecture may also include at least one input 610 , such as a keyboard, a touchscreen, a pen, voice-activated input, etc., and at least one output 612 , such as a display device, a speaker, a printer, etc.
[0070] The logic of FIGS. 4 and 5 describes specific operations occurring in a particular order. Further, the operations may be performed in parallel as well as sequentially. In alternative implementations, certain of the logic operations may be performed in a different order, modified or removed and still implement implementations of the present invention. Morever, steps may be added to the above described logic and still conform to the implementations. Yet further steps may be performed by a single process or distributed processes.
[0071] Many of the software and hardware components have been described in separate modules for purposes of illustration. Such components may be integrated into a fewer number of components or divided into a larger number of components. Additionally, certain operations described as performed by a specific component may be performed by other components.
[0072] Therefore, the foregoing description of the implementations has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many implementations of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. | Provided are a method, system, and article of manufacture, wherein in certain embodiments a first device determines a possibility of an invalidation of a second device, wherein the first device is coupled to the second device via a fabric. A query is sent from the first device to validate the second device, in response to determining the possibility of the invalidation of the second device. A determination is made, at the first device, whether to continue I/O operations from the first device to the second device based on receiving a response to the query within a time period. | 7 |
RELATED APPLICATIONS
[0001] This is a §371 of International Application No. PCT/JP2007/064882, with an international filing date of Jul. 30, 2007 (WO 2008/016003 A1, published Feb. 7, 2008), which is based on Japanese Patent Application No. 2006-207792, filed Jul. 31, 2006.
TECHNICAL FIELD
[0002] This disclosure provides a rear panel for plasma display in which a lattice-like barrier rib is formed on a substrate, and relates especially to a rear panel for plasma display which hardly generates an erroneous discharge of plasma.
BACKGROUND
[0003] As a useful component for flat and large TVs, plasma display panels (hereafter, referred to as PDP) have received greater attention. In the PDP, for example, on a glass substrate of front panel to be a display surface, a plural of coupled sustain electrode is formed with a material such as silver, chromium, aluminum or nickel. Furthermore, to cover the sustain electrode, a dielectric layer comprising glass as main component is formed in a thickness of 20 to 50 μm, and to cover the dielectric layer, a MgO layer is formed. On the other hand, on a glass substrate of rear panel, a plurality of address electrodes are formed in stripe-like fashion, and an a dielectric layer comprising glass as main component is formed to cover the address electrodes. On the dielectric layer, barrier ribs arc formed to partition discharge cells, and phosphor layers are formed in discharge spaces formed by the barrier ribs and the dielectric layer. In a PDP capable of displaying in full color, the phosphor layers are constituted with phosphors capable of irradiating respective RGB colors. The front panel and the rear panel are sealed such that the sustain electrodes on the glass substrate of the front panel and the address electrodes on the rear panel orthogonally intersect with each other, to form a PDP by enclosing a rare gas constituted with such as helium, neon or xenon in the gap between those substrates. Since pixels is formed, at intersections of the scan electrodes and the address electrodes as centers, the PDP has a plurality of pixels and it becomes possible to display an image.
[0004] For displaying an image in a PDP, when a sparkover voltage or more is charged between the sustain electrode and the address electrode in a selected pixel in a state in which no light is emitted, cations or electrons, generated by ionization, move to the electrode of the opposite polarity in the discharge space since the pixel acts as a capacitive load and charge the inner wall of the MgO layer, and the charge of the inner wall remains as wall charge without attenuation due to a high resistivity of the MgO layer.
[0005] Next, a discharge-sustaining voltage is charged between the scan electrode and the sustain electrode. It is possible to discharge even at a voltage lower than the sparkover voltage where the wall charge is present. By the discharge, xenon gas in the discharge space is excited and UV ray of 147 nm is generated, and a display becomes luminous by exciting the phosphor by the UV ray.
[0006] A rear panel for PDP in which, to enhance brightness by enlarging the surface area of phosphor layer, a lattice-like barrier rib consisting of main barrier ribs and auxiliary barrier ribs is known (e.g., refer to JP-H10-321148 A).
[0007] Regarding formation of the above-mentioned lattice-like barrier rib, it is general to form a lattice-like barrier rib pattern by a method such as coating a glass paste containing a low-melting-point glass powder and an organic component on the substrate on which the address electrodes and the dielectric layer are provided and patterning by a sandblast or a photolithography method, or by carrying out pattern printing by the transfer molding method or a screen printing method, and then carrying out firing to remove the organic component to form a lattice-like barrier rib of which main component is the low-melting-point glass.
[0008] However, in the case where a lattice-like barrier rib is formed by firing the barrier rib pattern prepared with such a glass paste, there was a problem that, due to a shrinkage by the organic component being removed at the firing, among the main barrier ribs, intersection portions of the main barrier ribs and the auxiliary barrier ribs positioned' n the nondisplay areas of right and left of the display area, especially, at the outermost portion thereof becomes higher than the height of the main barrier ribs positioned in the display area. In such a case where the height of the intersections of the main barrier ribs and the auxiliary barrier ribs of the nondisplay area become higher than the barrier ribs of the display area, when the PDP is emitted by applying a voltage, a charge-through becomes easy to occur at an edge of the display area, and there was an erroneous discharge such as a turning off of a cell in the edge of the display area which should normally emit, or an emitting of a neighboring cell which normally should not emit.
[0009] It could therefore be helpful to provide a plasma display member which does not generate an erroneous discharge at the edge of the display area.
SUMMARY
[0010] We thus provide rear panels for plasma displays having, on a substrate, approximately stripe-like address electrodes, a dielectric layer covering the address electrodes, and a lattice-like barrier rib positioned on the dielectric layer and consisting of main barrier ribs which are nearly parallel to the address electrodes and auxiliary barrier ribs intersecting the main barrier ribs, which is a rear panel for plasma display in which a bottom width of auxiliary barrier rib intersecting the main barrier rib positioned at the outermost portion, among the main barrier ribs positioned in nondisplay areas of right and left of the display area, is 0.3 to 1.0 times of a bottom width of the main barrier rib positioned at the outermost portion, among the main barrier ribs positioned in the nondisplay areas of right and left of the display area.
[0011] In addition, the production method of a rear panel for plasma display is a production method of a rear panel of the above-mentioned plasma display in which barrier ribs are formed, by coating a photosensitive glass paste consisting of an inorganic component mainly comprising glass powder and an organic component containing a photosensitive organic component on a substrate provided with address electrodes or precursor thereof and a dielectric layer or precursor thereof, exposing by using a photomask for forming precursors of auxiliary barrier rib, and after coating the photosensitive glass paste further, exposing by using a photomask for forming precursors of main barrier rib and developing to form precursors of barrier rib consisting of precursors of main barrier rib and precursors of auxiliary barrier rib, and firing to form barrier ribs, which is a production method of a rear panel for plasma display characterized in that a bottom width of precursor of auxiliary barrier rib intersecting the precursor of main barrier rib positioned at the outermost portion, among the precursors of main barrier rib positioned in nondisplay areas of right and left of a display area, is made into 0.3 to 1.0 times of a bottom width of precursor of main barrier rib positioned at the outermost portion, among the precursors of main barrier rib positioned in the nondisplay areas of right and left of the display area.
[0012] The intersection portion of, among the main barrier ribs, a main barrier rib of the nondisplay areas of right and left of the display area, especially, which are provided at both edges thereof and an auxiliary barrier rib does not become higher than the height of the main barrier ribs positioned in the display area, and in particular, it is possible to prevent an erroneous discharge at peripheral portion of the display area.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic diagram showing a barrier rib shape of the rear panel for PDP from the longitudinal direction of the main barrier ribs.
[0014] FIG. 2 is a schematic diagram showing a main barrier rib positioned at the outermost portion of the nondisplay areas of right and left of the display area of the rear panel for PDP, from the longitudinal direction of the auxiliary barrier ribs.
[0015] FIG. 3 is a schematic diagram showing the relation of positions on the rear panel for PDP.
EXPLANATION OF REFERENCES
[0000]
1 : substrate
2 : address electrode
3 : dielectric layer
4 : main barrier rib
5 : auxiliary barrier rib
6 : display area
7 : nondisplay area
8 : edge of display area
9 : outermost portion of nondisplay area
10 : rear panel for PDP
11 : outermost intersection portion of nondisplay area
P 1 : pitch between a main barrier rib positioned at the outermost portion of nondisplay area and a neighboring main barrier rib
P 2 : pitch between main barrier ribs positioned at display area
L 1 : bottom width of main barrier rib positioned at the outermost portion of nondisplay area
L 2 : bottom width of auxiliary barrier rib positioned at the outermost portion of nondisplay area
L 3 : bottom width of main barrier rib positioned at the outermost portion of display area
A: cut surface
DETAILED DESCRIPTION
[0033] Hereafter, our rear panels and methods are explained in detail with reference to the drawings. FIG. 1 is a schematic diagram showing a barrier rib shape of the rear panel for PDP from the longitudinal direction of the main barrier ribs. FIG. 2 is a schematic diagram showing a main barrier rib positioned at the outermost portion of the nondisplay areas of right and left of the display area of the rear panel for PDP, from the longitudinal direction of the auxiliary barrier ribs. FIG. 2 corresponds to a schematic diagram of the rear panel for PDP shown in FIG. 1 , observed from the cut surface A. FIG. 3 is a schematic diagram showing the relation of positions on the rear panel for PDP.
[0034] As the substrate 1 used as the rear panel for PDP, soda glass, heat resistant glass for PDP or the like can be used, and concretely, PD200 produced by Asahi Glass Co., Ltd., PP8 produced by Nippon Electric Glass Co., Ltd. or the like can be mentioned.
[0035] The nearly stripe-like address electrode 2 is preferably formed on the substrate 1 with a metal such as silver, aluminum, chromium or nickel. As the forming method, a screen printing method in which a metal paste of which main components are these metal powder and an organic binder is printed or a photosensitive paste method in which, after coating a photosensitive metal paste in which a photosensitive organic component is used as an organic binder, it is subjected to a pattern exposure by using a photomask, unnecessary portions are dissolved and removed through a development process, and furthermore, heated and fired at 400 to 600° C. to form a metal pattern, can be employed. An etching method in which, after sputtering a metal such as chromium or aluminum on a glass substrate, a resist is coated, and after the resist is subjected to a pattern exposure and a development, the metal of unnecessary portion is removed, can be employed. As the electrode thickness, 1 to 10 μm is preferable, and 1.5 to 8 μm is more preferable. When the electrode thickness is too thin, disconnected patterns may become easy to occur, or resistance becomes high and an accurate driving may become difficult. On the other hand, when it is too thick, much amount of the material is necessary and it may become disadvantageous in cost. A width of the address electrode 2 is preferably. 20 to 200 μm, more preferably 30 to 150 μm. When the width of the address electrode 2 is too narrow, a defect such as disconnection and chip may become easy to occur and product yield decreases, or resistance becomes high and an accurate driving may become difficult. On the other hand, when it is too thick, it will be more likely that the reactive power will increase, and the distance between neighboring electrodes will decrease to cause short circuit. Furthermore, the address electrode 2 is formed in a pitch which depends on display cell (region which forms the respective RGB of pixel). It is preferable to form in a pitch of 100 to 500 μm for an ordinary PDP, and in a pitch of 50 to 400 μm for a high definition PDP. Nearly stripe-like means a stripe-like pattern having a nearly parallel pattern in line, or a pattern in which a part of the electrode of stripe-like pattern is thickened or a part is curved.
[0036] Successively, the dielectric layer 3 is formed. The dielectric layer 3 can be formed by, after coating a glass paste of which main components are a glass powder and an organic binder in a form which covers the address electrode 2 , firing at 400 to 600° C. As the glass powder contained in the glass paste used for the dielectric layer 3 , a glass powder containing at least one kind or more of lead oxide, bismuth oxide, zinc oxide and phosphorus oxide and containing 10 to 80 wt % of them in total can preferably be used. By making the compound into 10 wt % or more, it becomes easy to fire at 600° C. or less, and by making into 80 wt % or less to prevent crystallization, it becomes easy to fire at 600° C. or less.
[0037] It is possible to prepare a paste by kneading these glass powder and organic binder. As an organic binder to be used, cellulose-based compounds represented by ethyl cellulose, methyl cellulose or the like, acryl-based compounds such as methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, methyl acrylate, ethyl acrylate or isobutyl acrylate, or the like can be used.
[0038] Furthermore, additives such as a solvent or a plasticizer may be added in the glass paste. As the solvent, widely-used solvents such as terpineol, butyrolactone, toluene, or methyl cellosolve can be used. As the plasticizer, dibutyl phthalate, diethyl phthalate, etc., can be used.
[0039] Furthermore, by adding filler other than the glass powder, it is possible to obtain a PDP having a high reflection and brightness. As the filler, titanium oxide, aluminum oxide and zirconium oxide or the like are preferable, and it is especially preferable to use a titanium oxide of which particle size is 0.05 to 3 μm. It is preferable that a content of the filler is, in the ratio of glass powder: filler, 1:1 to 10:1. By making the content of the filler into 1/10 or more to the glass powder, it is possible to achieve an actual effect, especially, improvement in brightness. By making into equal amount or less to the glass powder, it is possible to keep, especially, a high sintering performance. By adding an electroconductive fine particle, it is possible to manufacture a PDP which is highly reliable at driving. As the electroconductive fine particle, a metal powder such as of nickel or chromium is preferable, and as a particle size, 1 to 10 μm is preferable. By making it into 1 μm or more, a sufficient effect can be exhibited and by making it into 10 μm or less, it is possible to prevent unevenness on the dielectric layer to make formation of barrier rib easy. As a content of these electroconductive fine particles contained in the dielectric layer, 0.1 to 10 wt % is preferable. By making it into 0.1 wt % or more, an effective electroconductivity can be obtained, and by making it into 10 wt % or less, it is possible to sufficiently prevent a short circuit between neighboring address electrodes. A thickness of the dielectric layer 3 is preferably 3 to 30 μm and more preferably 3 to 15 μm. When the thickness of the dielectric layer 3 is too thin, a pinhole may occur frequently, and when it is too thick, discharge voltage becomes high and power consumption may become large.
[0040] Furthermore, in PDP, to control spreading of discharge into a predetermined region, to display in a prescribed cell, and to secure a uniform discharge space, a barrier rib (partitioning wall, also referred to as rib) is provided. As a shape of the barrier rib, in general, those such as of a stripe-like or a lattice-like, in a bottom width 20 to 120 μm and a height 50 to 250 μm, are mentioned.
[0041] Next, a method of forming the main barrier rib 4 and the auxiliary barrier rib 5 is explained. The main barrier rib 4 and the auxiliary barrier rib 5 are formed, after forming the address electrode 2 and the dielectric layer 3 on the substrate 1 , by using a paste for barrier rib consisting of an insulating inorganic component and an organic component and by a publicly-known method such as screen printing method, sandblast method, photosensitive paste method (photolithography method), transfer molding method or lift off method, by forming a lattice-like precursor of barrier rib consisting of precursors of main barrier rib which are nearly parallel to the above-mentioned address electrode 2 and a precursors of auxiliary barrier rib which intersect the precursors of main barrier rib and by firing. For the reason of such as shape control and uniformity of the barrier rib, among them, so-called photosensitive paste method (photolithography method) in which a photosensitive paste is coated on a substrate and dried to form a photosensitive paste film and is subjected to an exposure through a photomask and development, is preferably applied.
[0042] To the intersection portion of a main barrier rib and an auxiliary barrier rib, a stress is concentrated at firing, and the intersection portion becomes lower by several μm than main barrier ribs in the vicinity. On the other hand, among the nondisplay area 7 , at the intersection portions of main barrier rib and auxiliary barrier ribs positioned in the outermost portion 9 of the nondisplay area, a stress during firing is localized and the intersection portions becomes higher than main barrier ribs in the vicinity. This is caused because the intersection portions of the outermost portion are of T-shaped, the firing stress of the precursor of auxiliary barrier rib is loaded in one direction, namely, only in the direction of the display area side, and the intersection portions are raised high during firing. When the intersection portions of main barrier rib and auxiliary barrier ribs positioned at the outermost portion 9 of the nondisplay area become higher than the height of the main barrier ribs positioned in the display area, an erroneous discharge at the edge of the display area 8 occurs.
[0043] Thus, we provide a rear panel for PDP having a lattice-like barrier rib consisting of the main barrier ribs 4 and the auxiliary barrier ribs 5 which intersect main barrier ribs 4 , characterized in that, a bottom width L 2 of the auxiliary barrier ribs positioned at the outermost portion 9 of the nondisplay area among the auxiliary barrier ribs positioned in the nondisplay area 7 is 0.3 to 1.0 times of a bottom width L 1 of the main barrier rib positioned at the outermost portion 9 of the nondisplay area among the main barrier ribs positioned in the nondisplay area 7 . Here, the auxiliary barrier ribs positioned at the outermost portion 9 of the nondisplay area means the auxiliary barrier, ribs between a main barrier rib positioned at the outermost portion 9 of the nondisplay area and a neighboring main barrier rib.
[0044] Such main barrier ribs 4 and the auxiliary barrier ribs 5 can be formed, when the barrier ribs are formed by forming the precursor of lattice-like barrier rib consisting of the precursors of main barrier rib and the precursors of auxiliary barrier rib by using the paste for the barrier rib and by firing as mentioned above, by making the bottom width of the precursors of auxiliary barrier rib positioned at the outermost portion 9 of the nondisplay area among the precursors of auxiliary barrier rib positioned in the nondisplay area 7 into 0.3 to 1 times of the bottom width of the main barrier rib positioned at the outermost portion 9 of the nondisplay area among the precursors of main barrier rib positioned in the nondisplay area 7 .
[0045] Furthermore, the production method of the rear panel for plasma display is a production method of a rear panel for plasma display formed by coating a photosensitive glass paste consisting of an inorganic component mainly comprising a glass powder and an organic component containing a photosensitive organic component on a substrate, by exposing it through a photomask for forming precursors of auxiliary barrier rib, and after the photosensitive glass paste is coated further, by exposing it through a photomask for forming precursors of main barrier rib, by developing and by firing, and it is possible to form a predetermined bottom width of the precursor of barrier rib by controlling a line width of the photomask for forming the precursor, an amount of exposure and a dried film thickness.
[0046] By making L 2 into 0.3 to 1.0 times of L 1 to make the firing stress to the display area of the auxiliary barrier rib positioned at the outermost portion small, it is possible to prevent becoming the height of the intersections of the outermost portion higher than the height of main barrier ribs of the display area. When L 2 becomes larger than L 1 , the firing stress of the auxiliary barrier ribs increases, the height of intersection portions at the outermost portion becomes higher than the height of main barrier rib in the display area. On the other hand, when L 2 is 0.3 times or less of L 1 , strength of the precursor of auxiliary barrier rib before firing decreases and adhesion with the dielectric layer at the time of development decreases, to cause problems such as peeling off of the auxiliary barrier rib at the time of firing.
[0047] Furthermore, it is preferable to make the bottom width L 1 of the main barrier rib positioned at the outermost portion 9 of the nondisplay area into 1.2 to 3.0 times of the bottom width L 3 of the main barrier rib in the display area 6 . By making it into this range, it is possible to prevent that the height of the intersections with the auxiliary barrier ribs becomes higher than the height of the main barrier ribs positioned in the display area by increasing the firing stress to the longitudinal direction of the main barrier ribs positioned at the outermost portion 9 of the nondisplay area. It is possible to broaden a region capable of controlling the bottom width L 2 of the auxiliary barrier ribs in the outermost portion. When L 1 is smaller than 1.2 times of L 3 , it becomes necessary to form L 2 finer than L 1 , and it becomes difficult to form the precursor of auxiliary barrier rib positioned at the outermost portion. In the case where L 2 is larger than 3.0 times of L 1 , as well as the firing stress to the longitudinal direction of the main barrier rib, the firing stress to perpendicular direction of the stripe also increases, a warpage in top portion of the barrier rib generates, and the height of main barrier ribs in the nondisplay area 7 becomes higher than the height of the main barrier rib in the display area 6 , and an erroneous discharge cannot be prevented.
[0048] Furthermore, to make easier to form the above-mentioned main barrier rib and auxiliary barrier ribs in the outermost portion of the nondisplay area, it is preferable that the pitch P 2 between the main barrier rib positioned at the outermost portion 9 of the nondisplay area among the main barrier ribs positioned in the nondisplay area and the neighboring main barrier rib is at least 1.2 to 3 times of the pitch P 1 of the main barrier ribs positioned in the display area. In the case where the pitch between the main barrier ribs positioned in the display area is not uniform, for example, in the case where the pitch is changed depending on kind (color) of phosphor, its average value is taken as the pitch between the main barrier ribs positioned in the display area.
[0049] Furthermore, as the above-mentioned, it is allowable if the pitch P 2 between a precursor of main barrier rib positioned at the outermost portion and a neighboring precursor of main barrier rib is made into a pitch of at least 1.2 to 3.0 times of the pitch P 1 between the main barrier ribs positioned in the display area, but to effectively prevent an erroneous discharge, it is preferable that the pitch between the main barrier ribs positioned in preferably 0.5 to 3 mm from the outermost portion of the nondisplay area, more preferably, the pitches of all the main barrier ribs positioned in the nondisplay area are made into pitches of 1.2 to 3.0 times of the pitch between the main barrier ribs positioned in the display area.
[0050] It is because by making P 1 in the range of 1.2 to 3.0 times of P 2 , it becomes easy to form the bottom width L 1 of the main barrier rib in the nondisplay area thicker by 1.2 to 3.0 times than the bottom width L 3 of the main barrier rib in the display area. In the case where P 1 is smaller than 1.2 times of P 2 , when L 1 is tried to be formed thicker than L 3 , at forming the precursor of main barrier rib of the nondisplay area, neighboring bottoms of the barrier rib are connected, i.e., so-called a filling occurs. When a firing is carried out in a filled barrier rib, firing stress increases and problems occur such as a cracking of the dielectric layer. In the case where P 1 is larger than 3.0 times of P 2 , since density of the main barrier rib in the nondisplay area 7 becomes low, and since support points for front panel when a front panel is put thereon significantly decreases, problems occur in strength such as a chip of top of the main barrier rib.
[0051] Manufacturing method of the barrier rib is not especially limited, but as above-mentioned, the photosensitive paste method is preferable since its steps are not many and forming a fine pattern is possible.
[0052] The photosensitive paste method is a method in which, by forming a coating film with a photosensitive glass paste consisting of an inorganic component mainly comprising a glass powder and an organic component containing a photosensitive organic component, subjecting it to an exposure through a photomask and a development to form a precursor of barrier rib, and then the precursor of barrier rib is subjected to a firing to obtain a barrier rib.
[0053] Hereafter, a forming method of the barrier rib by the photosensitive paste method which is preferably employed is explained, but is not limited thereto.
[0054] In the case where the barrier rib is formed by the photosensitive paste method, a photosensitive glass paste for the barrier rib is coated on a dielectric layer. The photosensitive paste is constituted with an inorganic component mainly comprising glass powder and an organic component containing a photosensitive organic component.
[0055] The photosensitive glass paste for the barrier rib is prepared by kneading by a roll mill or the like, after mixing these inorganic components and the organic component in a predetermined weight ratio.
[0056] Next, this photosensitive glass paste for the barrier rib is coated by a die coater and dried. After the drying, a photomask provided with a stripe-like pattern corresponding to a pattern of auxiliary barrier rib is prepared and an exposure operation is carried out by keeping positions of the substrate and the photomask by using an exposure device while maintaining a distance. (gap) between the photomask and the coating film on the substrate.
[0057] Then, the photosensitive glass paste for the barrier rib is coated by using a die coater again and dried.
[0058] After that, a photomask provided with two kinds of stripe-like pattern different in the display area and the nondisplay area which corresponds to the pattern of main barrier rib is prepared, and by using an exposure equipment, while securing, the distance (gap) between the coating film on the substrate, and fixing positions of the substrate and the photomask, an exposure operation is carried out. After the exposure, a precursor of barrier rib consisting of the precursor of main barrier rib and the precursor of auxiliary barrier rib are formed by a development, and furthermore, by a firing, a predetermined barrier rib is obtained.
[0059] The rear panel for plasma display can preferably be manufactured by making, after a development, a bottom width of the precursors of auxiliary barrier rib intersecting the precursor of main barrier rib positioned at the outermost portion among the precursors of main barrier rib positioned in the nondisplay areas of right and left of the display area, 0.3 to 1.0 times of a bottom width of the precursor of main barrier rib positioned at the outermost portion among the precursors of main barrier rib positioned in the nondisplay areas of right and left of the display area, and then firing.
[0060] The pitch of barrier rib means, as shown in FIG. 1 , the interval from a center portion of barrier rib to a center portion of the next barrier rib, and the bottom widths of barrier rib mean, as shown in FIG. 1 , bottom widths of the respective barrier ribs. The shape of the barrier rib may be a rectangle or a trapezoid. A height the auxiliary barrier rib is lower than a height of the main barrier rib, and it is preferable to be a height of ½ to 11/12 of the height of main barrier rib.
[0061] Methods for measuring the pitch between main barrier ribs, the bottom width, the height of barrier rib and the height of intersection are not especially limited, but it is preferable to measure by using an optical microscope, a scanning electron microscope, or a laser scanning microscope.
[0062] For example, in the case where a scanning electron microscope (HITACHI S-2400) is used, the following method is preferable. For an accurate measurement of the edge of the barrier rib, a sample is cut such that a cross-section is perpendicular to the main barrier rib, and processed into a size capable of an observation. A magnification for measurement is selected in a range capable of viewing an inclined portion. A photograph is taken after correcting a scale with a standard sample of the same size as the inclined portion. From the scale, a bottom width, a pitch, and a height are calculated.
[0063] Furthermore, in the case where a nondestructive measurement is desired, a laser focus displacement meter (for example, LT-8010 produced by Keyence Corp.) may be used. In this case, too, it is preferable to measure after correcting with a standard sample in the same way. At this time, to carry out an accurate measurement, it is preferable to confirm that the measuring surface of the laser is parallel to the stripe direction of the barrier rib.
[0064] Furthermore, the height of main barrier rib, the height of the intersection may be determined by an ultradeep microscope (produced by Keyence). Bottom width of the barrier rib and groove width of the barrier rib may be measured by a microscope (produced by Hyrox).
[0065] It is preferable that an amount of the inorganic component used for the photosensitive glass paste for the barrier rib is 40 to 85 wt % with respect to the sum of the inorganic component and the organic component.
[0066] If it is less than 40 wt %, shrinkage at the firing increases and it is not preferable since a disconnection or peeling off of the barrier rib becomes easy to occur. It becomes hard to be dried paste to cause stickiness and printing properties may be impaired. Furthermore, widening of pattern and a generation of residual film at development may occur. If it is larger than 85 wt %, since the photosensitive organic component is not sufficient, light curing does not react at the bottom of barrier rib pattern, and the pattern-forming performance may be impaired.
[0067] In the case where this method is employed, it is preferable to use the following glass powder as the inorganic component.
[0068] To the glass powder, by adding such as aluminum oxide, barium oxide, calcium oxide, magnesium oxide, zinc oxide, zirconium oxide, especially, by adding aluminum oxide, barium oxide or zinc oxide, it is possible to control softening point, thermal expansion coefficient and refractive index, but as to its content, 40 wt % or less is preferable, and more preferably 25 wt % or less.
[0069] Furthermore, a glass generally used as an insulator has a refractive index of about 1.5 to 1.9, but in the case where a photosensitive paste meted is employed, and in the case where an average refractive index of organic component is largely different from an average refractive index of the glass powder, in the interface between the glass powder and the organic component, reflection or scattering increases and a precise pattern cannot be obtained. Since refractive index of generally-used organic component is 1.45 to 1.7, to match refractive indexes of the glass powder and the organic component, it is preferable to make an average refractive index of the glass powder into 1.5 to 1.7. Furthermore, it is more preferable to make it into 1.5 to 1.65.
[0070] By using a glass containing 2 to 10 wt % in total of an alkali metal oxide such as sodium oxide, lithium oxide or potassium oxide, not only it becomes easy to control softening point and thermal expansion coefficient, but also since it is possible to lower average refractive index of glass, it becomes easy to decrease the difference of refractive index with the organic substance. When it is smaller than 2%, it becomes difficult to control the softening point. When it is larger than 10%, due to an evaporation of the alkali metal oxide at discharge, there may be a case in which brightness decreases. Furthermore, to improve stability of the paste, too, it is preferable that the amount of alkali metal oxide to be added is less than 8 wt %, more preferably 6 wt % or less.
[0071] In particular, among the alkali metals, it is preferable to use lithium oxide, since it is possible to relatively increase stability of the paste. In the case where potassium oxide is used, there is a merit that, even by an addition of a relatively small amount, refractive index can be controlled.
[0072] This results in having a softening point capable of being fired on a glass substrate, makes it possible that an average refractive index is 1.5 to 1.7 and makes it easy that a refractive index difference from the organic component is small.
[0073] A particle size of the glass powder used in the above-mentioned is selected in consideration of a line width or a height of barrier rib to be prepared, but it is preferable that particle size of 50 vol % (average particle size, D50) is 1 to 6 μm, maximum particle size is 30 μm or less and specific surface area is 1.5 to 4 m 2 /g. More preferably, it is preferable that particle size of 10 vol % (D10) is 0.4 to 2 μm, particle size of 50 vol % (D50) is 1.5 to 6 μm, particle size of 90 vol % (D90) is 4 to 15 μm, maximum particle size is 25 μm or less and specific surface area is 1.5 to 3.5 m 2 /g. Further preferably, D50 is 2 to 3.5 μm and specific surface area is 1.5 to 3 m 2 /g.
[0074] D10, D50 and D90 can be obtained, respectively, from a distribution curve of volumetric-basis particle size, and from small particle, the mean particle sizes corresponding to 10 vol %, 50 vol % and 90 vol %.
[0075] When it is smaller than the above-mentioned particle size, since specific surface area increases, powder becomes easy to cohere and dispersibility in the organic component lowers, and air bubbles become easy to be included. Accordingly, light scattering increases and a widening of center of the barrier rib and an insufficiency of curing of the bottom occurs, and a preferable shape cannot be obtained. When it is large, property of filling is impaired due to a decrease of bulk density of the powder, and an amount of the photosensitive component becomes insufficient and air bubbles become easy to be included, to easily cause a light scattering, too.
[0076] Accordingly, there is an optimal range in the particle size distribution, and by using a glass powder in such a range of particle size distribution, property of filling with the powder is improved, air bubbles become hard to be included even when powder ratio of the photosensitive glass paste for the barrier rib is increased, and since unnecessary light scattering is small, the barrier rib pattern formation is maintained. In addition, since the filling rate of the powder is high, firing shrinkage decreases, pattern accuracy is improved, and a preferable barrier rib shape can be obtained.
[0077] As a filler, a high-melting-point glass powder containing 15 wt % or more of ceramics such as titania, alumina, barium titanate or zirconia, silicon oxide, or aluminum oxide, is preferable.
[0078] As a particle size of the filler to be used, an average particle size of 1 to 6 μm is preferable. It is preferable to use those having a particle size distribution, of which D10 (particle size of 10 vol %) is 0.4 to 2 μm, D50 (particle size of 50 vol %) is 1 to 3 μm, D90 (particle size of 90 vol %) is 3 to 8 μm, and a maximum particle size is 10 μm or less, for carrying out the pattern formation.
[0079] Still more preferably, it is preferable that D90 is 3 to 5 μm and the maximum particle size is 5 μm or less. It is preferable to be a fine powder of which D90 is 3 to 5 μm, since it is excellent in that a firing shrinkage can be made low, and in addition, a barrier rib of which void ratio is low is made. It becomes possible to make unevenness in longitudinal direction of upper portion of barrier rib into ±2 μm or less. When a powder with a large particle size is used as the filler, it is not preferable since, not only the void ratio increases, but also the unevenness of upper portion of barrier rib increases and causes an erroneous discharge.
[0080] As the organic component to be contained in the photosensitive glass paste for the barrier rib, it is possible to use cellulose compounds represented by ethyl cellulose, acryl polymers represented by polyisobutyl methacrylate or the like. Polyvinyl alcohol, polyvinyl butyral, polymer of methacrylic acid ester, polymer of acrylic acid ester, copolymer of acrylic acid ester and methacrylic acid ester, polymer of α-methyl styrene, butyl methacrylate resin, etc., are mentioned.
[0081] Other than those, to the glass paste, if necessary, various additives can be added, and in the case where a viscosity control is desired, an organic solvent may also be added. As the organic solvent to be used here, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl ethyl ketone, dioxane, acetone, cyclohexanone, cyclopentanone, isobutyl alcohol, isopropyl alcohol, tetrahydrofuran, dimethyl sulfoxide, γ-butyrolactone, bromobenzene, chlorobenzene, dibromobenzene, dichlorobenzene, bromobenzoic acid, chlorobenzoic acid, terpineol, etc., and organic solvent mixtures containing one kind or more of these, are used.
[0082] The organic component contains at least one kind photosensitive organic component selected from a photosensitive monomer, a photosensitive oligomer and a photosensitive polymer, and furthermore, as required, an addition of additive components such as a binder, a photo-polymerization initiator, a UV absorber, a sensitizer, a sensitizing auxiliary, a polymerization inhibitor, a plasticizer, a thickening agent, an organic solvent, an antioxidant, dispersant, or an organic or inorganic suspending agent, is also carried out.
[0083] As the photosensitive organic component, there are those of photo-insolubilized type and photo-solubilized type, and as those of photo-insolubilized type, (A) those containing a functional monomer, oligomer or polymer having one or more unsaturated group or the like in the molecule, (B) those containing a photosensitive compound such as an aromatic diazo compound, an aromatic azide compound or an organic halogen compound, and (C) so-called diazo resins such as condensate of a diazo-based amine and formaldehyde, etc., are mentioned.
[0084] Furthermore, as the photo-solubilized type, (D) those containing a complex of an inorganic salt of a diazo compound and organic acid, or quinone diazos, (E) quinone diazos bonded with an appropriate polymer binder, for example, naphtoquinone-1,2-diazide-5-sulfonate of a phenol or novolac resin, etc., are mentioned.
[0085] As the photosensitive organic component used for the photosensitive glass paste for the barrier rib, it is possible to use all of the above-mentioned. As a photosensitive organic component which can conveniently be used as the photosensitive glass paste for the barrier rib by mixing with the inorganic component, those of (A) are preferable.
[0086] The photosensitive monomer is a compound containing a carbon-carbon unsaturated bond, and as its concrete examples, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, sec-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-pentyl acrylate, allyl acrylate, etc., are mentioned. It is possible to use one kind, or two kinds or more of these.
[0087] Other than these, it is possible to improve performance of development after exposure by adding an unsaturated acid such as an unsaturated carboxylic acid. As concrete examples of the unsaturated carboxylic acid, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetic acid, or acid anhydride thereof, etc., are mentioned.
[0088] It is preferable that a content of these monomers is 5 to 30 wt % with respect to the sum of the inorganic component and the photosensitive organic component. In a range other than that, it is not preferable since an aggravation of pattern formation or an insufficiency of hardness after curing arises.
[0089] As the binder resin, polyvinyl alcohol, polyvinyl butyral, polymer of methacrylic acid ester, polymer of acrylic acid ester, copolymer of acrylic acid ester and methacrylic acid ester copolymer, polymer of α-methyl styrene, butyl methacrylate resin, etc., are mentioned.
[0090] Furthermore, it is possible to use an oligomer or polymer obtained by polymerizing at least one kind of compound having the above-mentioned carbon-carbon double bond. At the polymerization, it is possible to copolymerize with other photosensitive monomer such that a content of these photoreactive monomers would be 10 wt % or more, still more preferably 35 wt % or more.
[0091] As monomers to be copolymerized, by copolymerizing an unsaturated acid such as an unsaturated carboxylic acid, it is possible to improve performance of developing after exposure. As concrete examples of the unsaturated carboxylic acid, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetic acid, or an acid anhydride thereof, etc., are mentioned.
[0092] It is preferable that an acid value (AV) of the polymer or oligomer, thus obtained, having an acidic group such as carboxylic group in its side chain, is in the range of 30 to 150, furthermore, of 70 to 120. When the acid value is less than 30, solubility to developer of an unexposed portion decreases, and when concentration of the developer is increased, a peeling off up to exposed portion occurs, and a highly precise pattern is hard to be obtained. When the acid value exceeds 150, a tolerance of development is narrowed.
[0093] In the case where performance of development is imparted by a monomer such as an unsaturated acid, it is preferable since, a gelatification by a reaction between the glass powder and the polymer can be prevented, to make an acid value of the polymer into 50 or less.
[0094] By adding a photoreactive group to a side chain or molecular end of the above-mentioned polymer or oligomer, it is possible to use it as a photosensitive polymer or a photosensitive oligomer having photosensitivity. A preferable photoreactive group is that having an ethylenic unsaturated group. As the ethylenic unsaturated group, vinyl group, allyl group, acryl group, methacryl group or the like are mentioned.
[0095] As an amount of the polymer component containing of the photosensitive polymer, the photosensitive oligomer and the binder in the photosensitive glass paste, 5 to 30 wt % with respect to the sum of the glass powder and the photosensitive organic component is preferable since it is excellent in properties of pattern formation and shrinkage after firing. Out of this range, it is not preferable since a pattern formation is impossible or a widening of pattern occurs.
[0096] As concrete examples of the photopolymerization initiator, benzophenone, o-benzoyl methyl benzoate, 4,4-bis(dimethyl amine) benzophenone, 4,4-bis(diethyl amino) benzophenone, 4,4-dichlorobenzophenone, 4-benzoyl-4-methyl diphenyl ketone, dibenzyl ketone, fluorenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenyl-2-phenyl acetophenone, 2-hydroxy-2-methyl propiophenone, p-t-butyl dichloroacetophenone, thioxanthone, 2-methyl thioxanthone, 2-chlorothioxanthone, 2-isopropyl thioxanthone or combination of a photo-reductive pigment such as diethyl thioxanthone and a reducing agent such as ascorbic acid or triethanol amine, are mentioned. It is possible to use one kind, or two kinds or more of these.
[0097] The photopolymerization initiator is added in the range of 0.05 to 20 wt %, more preferably, 0.1 to 15 wt % with respect to the photosensitive organic component. When the amount of the polymerization initiator is too small, photosensitivity becomes poor, and when the amount of the photopolymerization initiator is too large, residual ratio of exposed portion may become too small.
[0098] It is also effective to add a UV absorber. By adding a compound having a high UV absorption feature, a high aspect ratio, a high definition and a high resolution are achieved. As UV absorbers, those composed of an organic dye, and among them, an organic dye having a high absorbing coefficient in the wavelength range of 350 to 450 nm is preferably used. Concretely, an azo-based dye, an aminoketone-based dye, a xanthene-based dye, a quinoline-based dye, an anthraquinone-based, a benzophenone-based, a diphenyl cyanoacrylate-based, a triazine-based, a p-aminobenzoic acid-based dye, etc., can be used. The organic dye is preferable since, even when it is added as a light absorbent, it does not remain in an insulating film after firing and it is possible to decrease the deterioration in the characteristics of the insulating film caused by a light absorbent. Among them, azo-based and benzophenone-based dyes are preferable.
[0099] It is possible to add a polymerization inhibitor to improve thermal stability during storage. As concrete examples of the polymerization inhibitor, hydroquinone, a monoesterified substance of hydroquinone, N-nitrosodiphenyl amine, phenothiazine, p-t-butyl catechol, N-phenyl naphthyl amine, 2,6-di-t-butyl -p-methyl phenol, chloranil, pyrogallol, or the like are mentioned.
[0100] In the photosensitive paste, in the case Where a control of solution viscosity is desired, an organic solvent may be added. As the organic solvent to be used at this time, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl ethyl ketone, dioxane, acetone, cyclohexanone, cyclopentanone, isobutyl alcohol, isopropyl alcohol, tetrahydrofuran, dimethyl sulfoxide, γ-butyrolactone, bromobenzene, etc., or an organic solvent mixtures containing one kind or, more of them, are used.
[0101] The photosensitive paste is prepared, generally, after compounding various components such as an inorganic fine particle, a UV absorber, a photosensitive polymer, a photosensitive monomer, a photopolymerization initiator, a glass frit and a solvent in a predetermined composition, by uniformly mixing and dispersing them by a triple roll mill or a kneader.
[0102] Next, a firing is carried out by a firing furnace. Firing atmosphere and temperature are different depending on the kind of paste and substrate, but the firing is carried out in an atmosphere such as in the air, nitrogen or hydrogen. As the firing furnace, it is possible to use a batch-type firing furnace or a belt-type continuous firing furnace.
[0103] In the case where a patterning is carried out on a glass substrate, a firing is carried out at a rate of temperature rise of 200 to 400° C./hr and maintaining at a temperature of 540 to 610° C. for 10 to 60 min. The firing temperature is determined depending on a glass powder to be used, but it is preferable to fire at an appropriate temperature at which a shape after the pattern formation is not deformed and the shape of the glass powder does not remain.
[0104] If it is lower than the appropriate temperature, void ratio and unevenness of upper portion of the barrier rib increase, and it is not preferable since discharging life is shortened or an erroneous discharge may become easy to occur.
[0105] Furthermore, if it is higher than the appropriate temperature, it is not preferable since a shape at the time of pattern formation is deformed and the upper portion of barrier rib becomes round or its height greatly decreases or a predetermined height cannot be obtained.
[0106] Furthermore, in the above-mentioned respective steps of coating, exposure, development and firing, for the purpose of drying or preliminary reaction, a heating process of 50 to 300° C. may be introduced.
[0107] After coating a phosphor paste by a method of discharging the phosphor paste from a dispenser, a phosphor layer is formed on side and bottom of the barrier rib by drying (e.g., at 180° C. for 15 min) and firing (e.g., at 500° C. for 30 min).
[0108] Thus obtained rear panel is laminated with a front panel and sealed, and then a rare gas for discharge such as helium, neon or xenon is enclosed, and a driving circuit was bonded to prepare a plasma display.
EXAMPLES
[0109] In the following, we explained in more detail with reference to examples. However, this disclosure is not limited thereto.
[0110] By the following procedures, a rear panel of 42 inch (590×964 mm) AC (alternate current) type plasma display panel was formed and an evaluation was conducted. The forming method is explained in turn. The concentration (%) in the examples and comparative examples is wt %. The height of main barrier ribs and the height of the intersection were measured by an ultradeep microscope (produced by Keyence). The pitch and the bottom width of barrier rib were measured by using a microscope (produced by Hyrox) for 20 points, respectively, and their averages were taken.
Example 1
[0111] As a glass substrate, PD-200 (produced by Asahi Glass Co.) of 590×964×2.8 mm was used. On this substrate, address electrodes were prepared by using a photosensitive silver paste. From the photosensitive silver paste, through steps of a coating, a drying, an exposure, a development and a firing, address electrodes of a line width 20 μm, a thickness 3 μm and a pitch 100 μm were formed.
[0112] Next, a glass paste obtained by kneading 60% of a low-melting-point glass powder containing 75 wt % of bismuth oxide, 10 wt % of a titanium oxide powder of average particle size 0.3 μm, 15% of ethyl cellulose and 15% of terpineol was coated by a screen printing such that bus electrodes of display portion were covered by 20 μm thickness, and then a firing at 570° C. for 15 min was carried out to form a dielectric layer.
[0113] On the dielectric layer, a photosensitive glass paste for barrier rib was coated. The photosensitive glass paste for barrier rib was constituted with a glass powder and an organic component containing a photosensitive organic component, and as the glass powder, a glass powder of average particle size 2 μm obtained by grinding a glass consisting of lithium oxide 10 wt %, silicon oxide 25 wt %, boron oxide 30 wt %, zinc oxide 15 wt %, aluminum oxide 5 wt % and calcium oxide 15 wt %, was used. As the organic component containing a photosensitive organic component, an organic component containing 30 wt % of an acryl polymer containing carboxylic group, 30 wt % of trimethylol propane triacrylate, 10 wt % of “Irgacure 369” (produced by Ciba-Geigy Ltd.) which is a photopolymerization initiator and 30 wt % of γ-butyrolactone, was used.
[0114] The photosensitive glass paste for barrier rib was prepared by mixing these glass powders and an organic component containing a photosensitive organic component in a weight ratio of 70:30, respectively, and then by kneading by a roll mill.
[0115] Next, by using a die coater, this photosensitive paste was coated such that a coating width would be 530 mm, a dried thickness would be 200 μm. The drying was carried out by Clean Oven (produced by Yamato Scientific Co.). After the drying, as a photomask corresponding to a pattern of a precursor of auxiliary barrier rib, a photomask provided with a stripe-like pattern having a pitch of 200 μm, a length of 940 mm, a line width in the display area of 60 μm and a line width in the nondisplay area of 60 μm was prepared, and by using a stepper exposure equipment (produced by Canon Inc.), the positions of the substrate and the photomask were exposed under the conditions of an exposure irradiance of 20 mW/cm 2 , an exposure time of 20 sec and a distance (gap) between the photomask and the coating film of the substrate of 100 μm.
[0116] Then, the photosensitive paste for barrier rib was coated again by using a die coater such that a coating width would be 600 mm and a dried thickness would be 30 μm. The drying was carried out by Clean Oven (produced by Yamato Scientific Co.).
[0117] A photomask provided with a stripe-like pattern of a pitch 100 μm, a width 40 μm and a length 536 mm in the display area and a stripe-like pattern of a pitch 120 μm, a width 55 μm and a length 536 mm in the nondisplay area was prepared, and by using a stepper exposure device (produced by Canon Inc.), an exposure operation on the position of the substrate and the photomask was carried out by an exposure irradiance of 20 mW/cm 2 , an exposure time for 20 sec and a distance (gap) between the photomask and the coating film of the substrate of 100 μm. After the exposure, it was developed in 0.5 wt % aqueous solution of ethanol amine, and further, fired at 580° C. for 15 min, to obtain a barrier rib.
[0118] As a result of measurement by a microscope, the bottom width of the auxiliary barrier rib positioned in the display area was 85 μm, and the bottom width L 2 positioned in the nondisplay area was 85 μm. The pitch P 1 of the main barrier rib positioned in the display area was 100 μm, and the pitch P 2 between a main barrier rib and a neighboring main barrier rib positioned at the outermost portion of the nondisplay area was 120 μm. A bottom width L 1 of the main barrier rib positioned at the outermost portion of the nondisplay area was 85 μm, and the bottom width L 3 of the main barrier rib positioned in the display area was 70 μm. Furthermore, the height of the main barrier rib in the display area was 161 μm, and the height of intersection portion of a main barrier rib and an auxiliary barrier rib positioned at the outermost portion in the nondisplay area was 160 μm. Next, a phosphor paste was coated by a dispenser, and after that, dried (at 180° C. for 15 min) and fired (at 500° C. for 30 min) to form a phosphor layer on side and bottom of the barrier rib. Thus obtained rear, panel was laminated with a front panel and sealed, and then the rare gases of helium and neon were enclosed therein for discharge operation, and a driving circuit was connected to prepare a plasma display. The plasma display was put on and, as a result, of evaluation, no erroneous discharge occurred.
Example 2
[0119] Barrier ribs were formed in the same way as Example 1 except preparing, for forming auxiliary barrier ribs, a photomask provided with a pattern which is a stripe-like pattern of a pitch 200 μm and a length 940 mm of which line width in display area is 60 μm and line width of nondisplay area is 60 μm, and using, for forming main barrier ribs, a photomask provided with a stripe-like pattern of a pitch 100 μm, a width 40 μm and a length 536 mm in display area and a photomask provided with a stripe-like pattern of a pitch 300 μm, a width 55 μm and a length 536 mm in nondisplay area. As a result of measurement by a microscope (produced by Hyrox), the bottom width of the auxiliary barrier rib positioned in the display area was 85 μm, and the bottom width L 2 positioned in the nondisplay area was 85 μm. The pitch P 1 of the main barrier rib positioned in the display area was 100 μm, and the pitch P 2 between a main barrier rib and a neighboring main barrier rib positioned at the outermost portion of the nondisplay area was 300 μm. A bottom width L 1 of the main barrier rib positioned at the outermost portion of the nondisplay area was 85 μm, and the bottom width L 3 of the main barrier rib positioned in the display area was 70 μm. Furthermore, the height of the main barrier rib in the display area was 162 μm, and the height of intersection portion of a main barrier rib and an auxiliary barrier rib positioned at the outermost portion in the nondisplay area was 157 μm. Next, a phosphor paste was coated by a dispenser, and after that, dried (at 180° C. for 15 min) and fired (at 500° C. for 30 min) to form a phosphor layer on side and bottom of the barrier rib. Thus obtained rear panel was laminated with a front panel and sealed, and then the rare gases of helium and neon to be used for discharge were enclosed therein, and a driving circuit was connected to prepare a plasma display. In a panel evaluation, no erroneous discharge occurred.
Example 3
[0120] Barrier ribs were formed in the same way as Example 1 except preparing, for forming auxiliary barrier ribs, a photomask provided with a pattern which is a stripe-like pattern of a pitch 200 μm and a length 940 mm of which line width in display area is 60 μm and line width of nondisplay area is 60 μm, and using, for forming main barrier ribs, a photomask provided with a stripe-like pattern of a pitch 100 μm, a width 55 μm and a length 536 mm in display area and a stripe-like pattern of a pitch 300 μm, a width 55 μm and a length 536 mm in nondisplay area. As a result of measurement by a microscope, the bottom width of the auxiliary barrier rib positioned in the display area was 85 μm, and the bottom width L 2 positioned in the nondisplay area was 85 μm. The pitch P 1 of the main barrier rib positioned in the display area was 100 μm, and the pitch P 2 between a main barrier rib and a neighboring main barrier rib positioned at the outermost portion of the nondisplay area was 300 μm. A bottom width L 1 of the main barrier rib positioned at the outermost portion of the nondisplay area was 85 μm, and the bottom width L 3 of the main barrier rib positioned in the display area was 85 μm. Furthermore, the height of the main barrier rib in the display area was 162 μm, and the height of intersection portion of a main barrier rib and an auxiliary barrier rib positioned at the outermost portion in the nondisplay area was 156 μm. Next, a phosphor paste was coated by a dispenser, and after that, dried (at 180° C. for 15 min) and fired (at 500° C. for 30 min) to form a phosphor layer on side and bottom of the barrier rib. Thus obtained rear panel was laminated with a front panel and sealed, and then rare gases of helium and neon which are gases for discharge were enclosed therein, and a driving circuit was connected to prepare a plasma display. In a panel evaluation, no erroneous discharge occurred.
Example 4
[0121] A rear panel member was formed in the same way as Example 1 except preparing, for forming auxiliary barrier ribs, a photomask provided with a pattern which is a stripe-like pattern of a pitch 200 μm and a length 940 mm of which line width in display area is 60 μm and line width of nondisplay area is 60 μm, and using, for forming main barrier ribs, a photomask provided with a stripe-like pattern of a pitch 100 μm, a width 40 μm and a length 536 mm in display area and a stripe-like pattern of a pitch 300 μm, a width 180 μm and a length 536 mm in nondisplay area. As a result of measurement by a microscope, the bottom width of the auxiliary barrier rib positioned in the display area was 85 μm, and the bottom width L 2 positioned in the nondisplay area was 85 μm. The pitch P 1 of the main barrier rib positioned in the display area was 100 μm, and the pitch P 2 between a main barrier rib and a neighboring main barrier rib positioned at the outermost portion of the nondisplay area was 300 μm. A bottom width L 1 of the main barrier rib positioned at the outermost portion of the nondisplay area was 210 μm, and the bottom width L 3 of the main barrier rib positioned in the display area was 70 μm. Furthermore, the height of the main barrier rib in the display area was 162 μm, and the height of intersection portion of a main barrier rib and an auxiliary barrier rib positioned at the outermost portion in the nondisplay area was 156 μm. Next, a phosphor paste was coated by a dispenser, and after that, dried (at 180° C. for 15 min) and fired (at 500° C. for 30 min) to form a phosphor layer on side and bottom of the barrier rib. Thus obtained rear panel was laminated with a front panel and sealed, and then rare gases of helium and neon which are gases for discharge were enclosed therein, and a driving circuit was connected to prepare a plasma display. In a panel evaluation, no erroneous discharge occurred.
Example 5
[0122] Barrier ribs were formed in the same way as Example 1 except preparing, for forming auxiliary barrier ribs, a photomask provided with a pattern which is a stripe-like pattern of a pitch 200 μm and a length 940 mm of which line width in display area is 60 μm and line width of nondisplay area is 60 μm, and using, for forming main barrier ribs, a photomask provided with a stripe-like pattern of a pitch 100 μm, a width 25 μm and a length 536 mm in display area and a stripe-like pattern of a pitch 200 μm, a width 110 μm and a length 536 mm in nondisplay area. As a result of measurement by a microscope, the bottom width of the auxiliary barrier rib positioned in the display area was 85 μm, and the bottom width L 2 positioned in the nondisplay area was 85 μm. The pitch P 1 of the main barrier rib positioned in the display area was 100 μm, and the pitch P 2 between a main barrier rib and a neighboring main barrier rib positioned at the outermost portion of the nondisplay area was 200 μm. A bottom width. L 1 of the main barrier rib positioned at the outermost portion of the nondisplay area was 140 μm, and the bottom width L 3 of the main barrier rib positioned in the display area was 55 μm. Furthermore, the height of the main barrier rib in the display area was 162 μm, and the height of intersection portion of a main barrier rib and an auxiliary barrier rib at the outermost portion of the nondisplay area was 156 μm. Next, a phosphor paste was coated by a dispenser to form a phosphor layer, and after that, dried (at 180° C. for 15 min) and fired (at 500° C. for 30 min) to form a phosphor layer on side and bottom of the barrier rib. Thus obtained rear panel was laminated with a front panel and sealed, and then rare gases of helium and neon which are gases for discharge were enclosed therein, and a driving circuit was connected to prepare a plasma display. In a panel evaluation, no erroneous discharge occurred.
Example 6
[0123] Barrier ribs were formed in the same way as Example 1 except preparing, for forming auxiliary barrier ribs, a photomask provided with a pattern which is a stripe-like pattern of a pitch 420 μm and a length 940 mm of which line width in display area is 60 μm and line width of nondisplay area is 35 μm, and using, for forming main barrier ribs, a photomask provided with a stripe-like pattern of a pitch 140 μm, a width 40 μm and a length 536 mm in display area and a stripe-like pattern of a pitch 140 μm, a width 40 μm and a length 536 mm in nondisplay area. As a result of measurement by a microscope, the bottom width of the auxiliary barrier rib positioned in the display area was 85 μm, and the bottom width L 2 positioned in the nondisplay area was 50 μm. The pitch P 1 of the main barrier rib positioned in the display area was 140 μm, and the pitch P 2 between a main barrier rib and a neighboring main barrier rib positioned at the outermost portion of the nondisplay area was 140 μm. A bottom width L 1 of the main barrier rib positioned at the outermost portion of the nondisplay area was 70 μm, and the bottom width L 3 of the main barrier rib positioned in the display area was 70 μm. Furthermore, the height of the main barrier rib in the display area was 163 μm, and the height of intersection portion of a main barrier rib and an auxiliary barrier rib at the outermost portion in the nondisplay area was 160 μm. Next, a phosphor paste was coated by a dispenser to form a phosphor layer, and after that, dried (at 180° C. for 15 min) and fired (at 500° C. for 30 min) to form a phosphor layer on side and bottom of the barrier rib. Thus obtained rear panel was laminated with a front panel and sealed, and then rare gases of helium and neon which are gases for discharge were enclosed therein, and a driving circuit was connected to prepare a plasma display. In a panel evaluation, no erroneous discharge occurred.
Example 7
[0124] Barrier ribs were formed in the same way as Example 1 except preparing, for forming auxiliary barrier ribs, a photomask provided with a pattern which is a stripe-like pattern of a pitch 420 μm and a length 940 mm of which line width in display area is 60 μm and line width of nondisplay area is 35 μm, and using, for forming main barrier ribs, a photomask provided with a stripe-like pattern of a pitch 140 μm, a width 40 μm and a length 536 mm in display area and a stripe-like pattern of a pitch 140 μm, a width 60 μm and a length 536 mm in nondisplay area. As a result of measurement by a microscope, the bottom width of the auxiliary barrier rib positioned in the display area was 85 μm, and the bottom width L 2 positioned in the nondisplay area was 50 μm. The pitch P 1 of the main barrier rib positioned in the display area was 140 μm, and the pitch P 2 between a main barrier rib and a neighboring main barrier rib positioned at the outermost portion of the nondisplay area was 140 μm. A bottom width L 1 of the main barrier rib positioned at the outermost portion of the nondisplay area was 90 μm, and the bottom width L 3 of the main barrier rib positioned in the display area was 70 μm. Furthermore, the height of the main barrier rib in the display area was 163 μm, and the height of intersection portion of a main barrier rib and an auxiliary barrier rib at the outermost portion in the nondisplay area was 158 μm. Next, a phosphor paste was coated by a dispenser to form a phosphor layer, and after that, dried (at 180° C. for 15 min) and fired (at 500° C. for 30 min) to form a phosphor layer on side and bottom of the barrier rib. Thus obtained rear panel was laminated with a front panel and sealed, and then rare gases of helium and neon which are gases for discharge were enclosed therein, and a driving circuit was connected to prepare a plasma display. In a panel evaluation, no erroneous discharge occurred.
Example 8
[0125] Barrier ribs were formed in the same way as Example 1 except preparing, for forming auxiliary barrier ribs, a photomask provided with a pattern which is a stripe-like pattern of a pitch 420 μm and a length 940 mm of which line width in display area is 60 μm and line width of nondisplay area is 60 μm, and using, for forming main barrier ribs, a photomask provided with a stripe-like pattern of a pitch 140 μm, a width 40 μm and a length 536 mm in display area and a stripe-like pattern of a pitch 300 μm, a width 80 μm and a length 536 mm in nondisplay area. As a result of measurement by a microscope, the bottom width of the auxiliary barrier rib positioned in the display area was 85 μm, and the bottom width L 2 positioned in the nondisplay area was 85 μm. The pitch P 1 of the main barrier rib positioned in the display area was 140 μm, and the pitch P 2 between a main barrier rib and a neighboring main barrier rib positioned at the outermost portion of the nondisplay area was 300 μm. A bottom width L 1 of the main barrier rib positioned at the outermost portion of the nondisplay area was 110 μm, and the bottom width L 3 of the main barrier rib positioned in the display area was 70 μm. Furthermore, the height of the main barrier rib in the display area was 163 μm, and the height of intersection portion of a main barrier rib and an auxiliary barrier rib at the outermost portion in the nondisplay area was 158 μm. Next, a phosphor paste was coated by a dispenser to form a phosphor layer, and after that, dried (at 180° C. for 15 min) and fired (at 500° C. for 30 min) to form a phosphor layer on side and bottom of the barrier rib. Thus obtained rear panel was laminated with a front panel and sealed, and then rare gases of helium and neon which are gases for discharge were enclosed therein, and a driving circuit was connected to prepare a plasma display. In a panel evaluation, no erroneous discharge occurred.
Comparative Example 1
[0126] Barrier ribs were formed in the same way as Example 1 except preparing, for forming auxiliary barrier ribs, a photomask provided with a pattern which is a stripe-like pattern of a pitch 200 μm and a length 940 mm of which line width in display area is 60 μm and line width of nondisplay area is 60 μm, and using, for forming main barrier ribs, a photomask provided with a stripe-like pattern of a pitch 100 μm, a width 25 μm and a length 536 mm in display area and a stripe-like pattern of a pitch 100 μm, a width 25 μm and a length 536 mm in nondisplay area. As a result of measurement by a microscope, the bottom width of the auxiliary barrier rib positioned in the display area was 85 μm, and the bottom width L 2 positioned in the nondisplay area was 85 μm. The pitch P 1 of the main barrier rib positioned in the display area was 100 μm, and the pitch P 2 between a main barrier rib and a neighboring main barrier rib positioned at the outermost portion of the nondisplay area was 100 μm. A bottom width L 1 of the main barrier rib positioned at the outermost portion of the nondisplay area was 55 μm, and the bottom width L 3 of the main barrier rib positioned in the display area was 55 μm. Furthermore, the height of the main barrier rib in the display area was 162 μm, and the height of intersection portion of a main barrier rib and an auxiliary barrier rib positioned at the outermost portion in the nondisplay area was 170 μm. Next, a phosphor paste was coated by a dispenser to form a phosphor layer, and after that, dried (at 180° C. for 15 min) and fired (at 500° C. for 30 min) to form a phosphor layer on side and bottom of the barrier rib. Thus obtained rear panel was laminated with a front panel and sealed, and then rare gases of helium and neon which are gases for discharge were enclosed therein, and a driving circuit was connected to prepare a plasma display. As a result of a panel evaluation, erroneous discharges occurred at right and left edges of the display area.
Comparative Example 2
[0127] Barrier ribs were formed in the same way as Example 1 except preparing, for forming auxiliary barrier ribs, a photomask provided with a pattern which is a stripe-like pattern of a pitch 200 μm and a length 940 mm of which line width in display area is 60 μm and line width of nondisplay area is 60 μm, and using, for forming main barrier ribs, a photomask provided with a stripe-like pattern of a pitch 100 μm, a width 40 μm and a length 536 mm in display area and a stripe-like pattern of a pitch 340 μm, a width 40 μm and a length 536 mm in nondisplay area. As a result of measurement by a microscope, the bottom width of the auxiliary barrier rib positioned in the display area was 85 μm, and the bottom width L 2 positioned in the nondisplay area was 85 μm. The pitch P 1 of the main barrier rib positioned in the display area was 100 μm, and the pitch P 2 between a main barrier rib and a neighboring main barrier rib positioned at the outermost portion of the nondisplay area was 340 μm. A bottom width L 1 of the main barrier rib positioned at the outermost portion of the nondisplay area was 75 μm, and the bottom width L 3 of the main barrier rib positioned in the display area was 75 μm. Furthermore, the height of the main barrier rib in the display area was 162 μm, and the height of intersection portion of a main barrier rib and an auxiliary barrier rib positioned at the outermost portion in the nondisplay area was 172 μm. Next, a phosphor paste was coated by a dispenser to form a phosphor layer, and after that, dried (at 180° C. for 15 min) and fired (at 500° C. for 30 min) to form a phosphor layer on side and bottom of the barrier rib. Thus obtained rear panel was laminated with a front panel and sealed, and then rare gases of helium and neon which are gases for discharge were enclosed therein, and a driving circuit was connected to prepare a plasma display. As a result of a panel evaluation, erroneous discharges occurred at right and left edges of the display area.
Comparative Example 3
[0128] Barrier ribs were formed in the same way as Example 1 except preparing, for forming auxiliary barrier ribs, a photomask provided with a pattern which is a stripe-like pattern of a pitch 420 μm and a length 940 mm of which line width in display area is 60 μm and line width of nondisplay area is 90 μm, and using, for forming main barrier ribs, a photomask provided with a stripe-like pattern of a pitch 140 μm, a width 40 μm and a length 536 mm in display area and a stripe-like pattern of a pitch 300 μm, a width 40 μm and a length 536 mm in nondisplay area. As a result of measurement by a microscope, the bottom width of the auxiliary barrier rib positioned in the display area was 85 μm, and the bottom width L 2 positioned in the nondisplay area was 115 μm. The pitch P 1 of the main barrier rib positioned in the display area was 100 μm, and the pitch P 2 between a main barrier rib and a neighboring main barrier rib positioned at the outermost portion of the nondisplay area was 300 μm. A bottom width L 1 of the main barrier rib positioned at the outermost portion of the nondisplay area was 70 μm, and the bottom width L 3 of the main barrier rib positioned in the display area was 70 μm. Furthermore, the height of the main barrier rib in the display area was 162 μm, and the height of intersection portion of a main barrier rib and an auxiliary barrier rib positioned at the outermost portion in the nondisplay area was 176 μm. Next, a phosphor paste was coated by a dispenser to form a phosphor layer, and after that, dried (at 180° C. for 15 min) and fired (at 500° C. for 30 min) to form a phosphor layer on side and bottom of the barrier rib. Thus obtained rear panel was laminated with a front panel and sealed, and then rare gases of helium and neon which are gases for discharge were enclosed therein, and a driving circuit was connected to prepare a plasma display. As a result of a panel evaluation, erroneous discharges occurred at right and left edges of the display area.
[0000]
TABLE 1
The pattern of the photomask corresponding to a pattern
The pattern of the photomask corresponding to a pattern
of a precursor of main barrier rib
of a precursor of auxiliary barrier rib
In the display area
In the nondisplay area
In the display area
In the nondisplay area
Pitch
Width
Pitch
Width
Length
Pitch
Width
Pitch
Width
Length
The photomask used for
100 mm
40 mm
120 mm
55 mm
536 mm
200 mm
60 mm
200 mm
60 mm
940 mm
example 1
The photomask used for
100 mm
40 mm
300 mm
55 mm
536 mm
200 mm
60 mm
200 mm
60 mm
940 mm
example 2
The photomask used for
100 mm
55 mm
300 mm
55 mm
536 mm
200 mm
60 mm
200 mm
60 mm
940 mm
example 3
The photomask used for
100 mm
40 mm
300 mm
180 mm
536 mm
200 mm
60 mm
200 mm
60 mm
940 mm
example 4
The photomask used for
100 mm
25 mm
200 mm
110 mm
536 mm
200 mm
60 mm
200 mm
60 mm
940 mm
example 5
The photomask used for
140 mm
40 mm
140 mm
40 mm
536 mm
420 mm
60 mm
420 mm
35 mm
940 mm
example 6
The photomask used for
140 mm
40 mm
140 mm
60 mm
536 mm
420 mm
60 mm
420 mm
35 mm
940 mm
example 7
The photomask used for
140 mm
40 mm
300 mm
80 mm
536 mm
420 mm
60 mm
420 mm
60 mm
940 mm
example 8
The photomask used for
100 mm
25 mm
100 mm
25 mm
536 mm
200 mm
60 mm
200 mm
60 mm
940 mm
comparative example 1
The photomask used for
100 mm
40 mm
340 mm
40 mm
536 mm
200 mm
60 mm
200 mm
60 mm
940 mm
comparative example 2
The photomask used for
140 mm
40 mm
300 mm
40 mm
536 mm
420 mm
60 mm
420 mm
90 mm
940 mm
comparative example 3
[0000]
TABLE 2
Height of intersection portion
of a main barrier rib and
Height of the main
an auxiliary barrier rib
Bottom width of
Pitch between main
barrier rib in the
positioned at the outermost
barrier rib (μm)
barrier ribs (μm)
display area
portion in the nondisplay
Erroneous
L1
L2
L3
L2/L1
L1/L3
P1
P2
P2/P1
(μm)
area (μm)
discharge
Example 1
85
85
70
1.0
1.2
100
120
1.2
161
160
No
Example 2
85
85
70
1.0
1.2
100
300
3.0
162
157
No
Example 3
85
85
85
1.0
1.0
100
300
3.0
162
156
No
Example 4
210
85
70
0.4
3.0
100
300
3.0
162
156
No
Example 5
140
85
55
0.6
2.5
100
200
2.0
162
156
No
Example 6
70
50
70
0.7
1.0
140
140
1.0
163
160
No
Example 7
90
50
70
0.6
1.3
140
140
1.0
163
158
No
Example 8
110
85
70
0.8
1.6
140
300
2.1
163
158
No
Comparative
55
85
55
1.5
1.0
100
100
1.0
162
170
Occurred
example 1
Comparative
70
85
70
1.2
1.0
100
340
3.4
162
172
Occurred
example 2
Comparative
70
115
70
1.6
1.0
140
300
2.1
162
176
Occurred
example 3
The references in Table 2 denote the following:
P1: pitch between main barrier ribs positioned in display area
P2: pitch between a main barrier rib positioned at the outermost portion in non-display area and a neighboring main barrier rib
L1: bottom width of main barrier rib positioned at the outermost portion in non-display area
L2: bottom width of auxiliary barrier rib positioned at the outermost portion in nondisplay area
L3: bottom width of main barrier rib positioned at the outermost portion in display area | A plasma display member does not cause an erroneous discharge in a display region end portion and includes: a substrate ( 1 ); a substantially stripe-shaped address electrode ( 2 ) arranged on the substrate ( 1 ); a dielectric layer ( 3 ) covering the address electrode ( 2 ) and a grid-shaped partition arranged on the dielectric layer ( 3 ) and having main walls ( 4 ) substantially parallel to the address electrode ( 2 ) and auxiliary walls ( 5 ) intersecting the main partitions ( 4 ). The auxiliary wall ( 5 ) intersecting the main wall ( 4 ) located at the outermost position among the main walls ( 4 ) located at non-display regions ( 7 ) at the right and left of a display region ( 6 ) has a bottom width identical to the bottom width (L 1 ) of the main wall ( 4 ) located at the outermost position among the main walls ( 4 ) located at the non-display regions ( 7 ) at the right and left of the display region ( 6 ) which is multiplied by 0.3 to 1.0. | 7 |
FIELD OF THE INVENTION
The present invention relates to tape measures and in particular relates to tape measures which include an audio recording device attached thereto.
BACKGROUND OF THE INVENTION
Users of a conventional type tape measuring devices are required to either manually or mentally make a record of the measurement which they are taking. Individuals using conventional tape measuring devices either carry pads of paper and pen or pencil with them to record the measurements that they are taking or simply commit them to memory. The use of pencil and paper to record the measurements is extremely cumbersome and committing the measurements to memory often can result in errors and/or having to re-measure forgotten dimensions.
There is a need for a tape measure which eliminates the use of pencil and paper and eliminates the need for committing to memory dimensions and measurements that have been taken with a tape measure in order to more efficiently and effectively use a tape measure in the field.
SUMMARY OF THE INVENTION
The present concept a tape measure in combination with an audio comprising:
a) A voice recorder includes a front cover, a push pad, a circuit board and a back cover. b) Wherein the voice recorder adapted to record and play back audio recordings. c) Wherein the voice recorder is releasably attached to the tape measure such that the back cover abuts against a side of the tape measure.
Preferably wherein the front cover, the push pad, the circuit board and the back cover are layers of uniform outer dimension which are sandwiched together to form a unitary layered structure.
Preferably wherein each of the layers is circular each having the same outer diameter.
Preferably wherein the push pad is sandwiched between the front cover and the circuit board and includes button pads for controlling the recording and playback functions.
Preferably wherein the circuit board is sandwiched between the push pad and the back cover end includes a battery compartment and a speaker compartment.
The present concept a tape measure in combination with an attachable data transceiver, a headset and a cell phone comprising:
a) a data transceiver for mounting to a tape measure; b) the data transceiver includes a housing with numerous selectors including at least one record button and one playback button; the transceiver housing for mounting to a tape measure; c) the transceiver is in communication with a first user cell phone, wherein depressing the record button instructs the cell phone to record verbal analogue data received from a headset
Preferably wherein the cell phone includes a cell phone application for recording and playback of analogue data.
Preferably wherein the cell phone including a cell phone application for converting verbal analogue data into digital data using voice recognition software and recording and playback of the digital data.
Preferably wherein when the at least one playback button is depressed the data transceiver instructs the cell phone to playback the recorded digital data to the headset.
Preferably wherein further including at least two users, each user includes a data transceiver including a user selector, a tape measure, a headset and a cell phone, the user selector for instructing connection of the first users cell phone to at least one other second user cell phone by placing the user selector in the appropriate position, such that depressing the record button instructs simultaneous recordation of data received from a first headset onto the first and second user's cell phone wherein each cell phone is equipped with the cell phone application and is in communication with an associated headset.
Preferably such that depressing the playback button on either the first or second users data transceiver instructs simultaneous playback of data on the first user's cell phone to the first and the second user's headsets.
Preferably wherein the data transceiver further includes a calculate button selector which when pushed instructs the cell phone application to add together the last two recorded data points and record a calculated addition.
Preferably wherein the data transceiver further includes a respond button selector which when pushed instructs the cell phone application to playback the calculated addition to the user selected headsets.
Preferably wherein the data transceiver further includes a drawing button selector which when pushed instructs the cell phone application to project drawings stored in the cell phone using a LED projector light in the tape measure.
Preferably wherein the data transceiver further includes a walkie-talkie button selector which when pushed instructs the cell phone application to transmit in real time any voice data received from first users headset to the user selected phone and associated headset, thereby permitting selected users to speak to each other in walkie-talkie fashion.
Preferably wherein the digital data is numerical tape measurements.
Preferably wherein the data transceiver attached to the tape measure with a centrally located fastener.
Preferably wherein the data transceiver includes a cylindrical puck shaped housing for attaching to a side of the tape measure using a centrally located screw.
The present concept a digital tape measure in combination with a data transceiver, a headset and a cell phone comprising:
a) a data transceiver; b) the data transceiver includes a housing with numerous selectors including at least one record button and one playback button; the transceiver receiving digital measurement data from the tape measure when the tape of the tape measure is extended; c) the transceiver in communication with a first user cell phone, wherein depressing the record button instructs the cell phone to record digital data received from the tape measure. d) the cell phone including a cell phone application for communicating and storing digital data.
Preferably wherein when the at least one playback button is depressed the data transceiver instructs the cell phone to playback the recorded digital data to the headset.
Preferably wherein further including at least two users, each user includes a data transceiver including a user selector, a tape measure, a headset and a cell phone, the user selector for instructing connection of the first users cell phone to at least one other second users cell phone by placing the user selector in the appropriate position, such that depressing the record button instructs simultaneous recordation of data received from a first tape measure onto the first and second user's cell phone wherein each cell phone is equipped with the cell phone application and is in communication with an associated headset.
Preferably such that depressing the playback button on either the first or second users data transceiver instructs simultaneous playback of data on the first user's cell phone to the first and the second user's headsets.
The present concept a tape measure in combination with a data transceiver, a headset and a cell phone comprising:
a) a data transceiver integrally part of the tape measure; b) the data transceiver includes a housing with numerous selectors including at least one record button and one playback button; c) the transceiver is in communication with a first user cell phone, wherein depressing the record button instructs the cell phone to record verbal analogue data received from a headset.
Preferably wherein when the at least one playback button is depressed the data transceiver instructs the cell phone to playback the recorded data to the headset.
Preferably wherein further including at least two users, each user includes a data transceiver including a user selector, a tape measure, a headset and a cell phone, the user selector for instructing connection of the first users cell phone to at least one other second user cell phone by placing the user selector in the appropriate position, such that depressing the record button instructs simultaneous recordation of data received from a first headset onto the first and second user's cell phone wherein each cell phone is equipped with the cell phone application and is in communication with an associated headset.
BRIEF DESCRIPTION OF THE DRAWINGS
The present concept will now be described by way of example only with reference to the following drawings in which:
FIG. 1 is a top schematic perspective view of a tape measure with an voice recorder.
FIG. 2 is a front schematic perspective view of the voice recorder attached on the tape measure.
FIG. 3 is a schematic perspective exploded view of the voice recorder shown in FIG. 2 .
FIG. 4 is a schematic partial cross-sectional of a voice recorder shown attached to a tape measure.
FIG. 5 is a top schematic perspective view of an alternate embodiment of the present invention namely a tape measure with audio recorder.
FIG. 6 is a top perspective view of the voice recorder shown in FIG. 5 detached from the tape measure.
FIG. 7 is a front schematic plan view of a tape measure attachment.
FIG. 8 is a front schematic plan view of a tape measure attachment.
FIG. 9 is a schematic diagram showing a tape measure attachment 400 deployed onto a person together with the interaction of the signals of a cell phone.
FIG. 10 is a schematic of two tape attachments deployed onto two independent persons together with the signal interaction between the tape measure attachments cell phones and head pieces.
FIG. 11 is a schematic screen shot of a cell phone showing a data lock.
FIG. 12 is a schematic showing the LED projector projecting an image of a blueprint onto a surface.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 through 4 which show the first embodiment namely tape measure with audio recorder shown generally as 100 which includes the following major components namely; voice recorder 102 attached to tape measure 104 .
Conventional tape measure shown as 104 in FIG. 1 includes a right side 106 , a left side 108 , a top side 110 , a bottom side 112 , also includes tape blade 114 and a blade lock 116 .
Voice recorder 102 includes the following components namely front cover 120 and outer cover 122 , push buttons 124 , speaker 126 , battery cover 128 and a screw 130 .
Referring now to FIG. 3 voice recorder 102 is shown in exploded fashion with outer cover 122 removed.
Voice recorder 102 includes front cover 120 a push pad 132 , a circuit board 134 , a back cover 136 .
Front cover 120 includes speaker cut-out 140 and a battery aperture 142 and screw 130 passes there-though approximately at the centre of front cover 120 .
Push pad 132 includes 6 button pads shown as 144 as well as a battery aperture 142 and speaker cut-out 140 .
Circuit board 134 includes a battery compartment 146 housing a battery 148 as well as a speaker compartment 150 housing a speaker with an integrated speaker cover 126 .
Circuit board 134 also includes button contacts 155 in order to close the circuit when a button pad 144 is pushed using finger pressure from the outside of voice recorder 102 . Circuit board 134 also includes an integrated circuit 152 which includes the electronic circuitry for recording audio signals as well as playing back audio signals when required.
Circuit board 134 is sandwiched between push pad 132 and back cover 136 .
The four major components namely front cover 120 , push pad 132 , circuit board 134 and back cover 136 are assembled in sandwich fashion as shown in FIGS. 3 and 4 and held together with screw 130 which passes through each of these components and into the left side of tape measure 104 .
FIG. 4 shows voice recorder 102 mounted onto the left side of tape measure 104 . Screw 130 passes through screw hole 192 and into left side 108 of the body of tape measure 104 thereby securing voice recorder 102 abutting against and onto the left side 108 of tape measure 104 . Tape measure 104 also includes a belt clip 190 .
Referring now to FIGS. 5 and 6 which shows an alternate embodiment namely tape measure with audio recorder 200 which includes a detachable recorder case 220 which includes push buttons 204 , speaker 206 , left portion 208 , right portion 212 , top portion 210 and bottom portion 214 .
Recorder case 220 of voice recorder 202 has a releasable interlock 216 which forms an inner lock seam 218 as shown in FIG. 6 .
In other words recorder case 220 can be easily attached and removed from tape measure 104 by simply locking into position inter lock 216 and/or unlocking inter lock 216 as required.
In Use
In use tape measure with audio recorder 100 and/or tape measure with audio recorder 200 can record audio signals of the user. In other words someone taking a measurement with tape measure 104 can push one of the push buttons 124 and/or push button 204 which will start a voice recording of a particular measurement that is presently being taken.
Upon release of push button 124 and/or 204 the recording ends.
The user can then record a second measurement using a different push button 124 and/or 204 that was initially and again the voice recording is recorded by voice recorder 102 and/or voice recorder 202 and the recording ends when the push button is released.
In this manner up to six different voice recordings and measurements can be recorded and taken by voice recorder 102 and/or voice recorder 202 thereby helping the user to remember the measurements that have been taken with the tape measure 104 .
Other Embodiments
FIG. 7 depicts another embodiment namely a tape measure attachment shown generally as 300 which includes the following major components namely a housing 302 , three record buttons 304 , three replay buttons 306 , a mounting screw 308 , a speaker 310 .
Tape measure attachment 300 is used in similar if not identical fashion to tape measure with audio recorder 100 except for the fact that tape measure attachments 300 includes three separate record buttons and three separate reply buttons. Tape measure attachment 300 can be attached to the side of a tape measure in similar fashion as shown for tape measure with audio recorder 100 in FIG. 1 or also could be integrally part of an originally equipment produced tape measure.
Tape measure attachment 300 can record three separate recordings by pushing record button 304 number “ 1 ”, “ 2 ” or “ 3 ”. In order to play back the voice recordings one would simply hit the replay button 306 corresponding to the record button.
Once three recordings have been completed with record buttons 1 , 2 and 3 , one can simply overwrite what has been recorded at button 1 by simply pressing again on record button number 1 304 and making a new recording. The previous recording will be erased.
FIG. 8 shows data transceiver 401 which could be a tape measure attachment 400 or could be integrally part of a tape measure having the following major components namely three record buttons 404 , three playback buttons 406 , similar to tape measure 300 and additionally it also includes a calculate button 408 , a playback button 410 , a drawing button 412 which controls LED Projector 414 , a walkie talkie button 418 , and a user selector 416 .
Data transceiver 401 shown as a tape measure attachment 400 is held on with a screw 420 onto any standard tape measure and includes a housing 402 .
In similar fashion as tape measure with audio recorder 100 data transceiver 401 can either be screwed onto an existing tape measure 104 as shown in FIG. 1 or it can be made integrally part of an original equipment tape in which case data transceiver 401 components would be integrally made together with a tape measure 104 from the outset.
data transceiver 401 has the added advantage that it can communicate either wired or wirelessly to any cell phone either by blue tooth or by other wireless means.
Shown in FIG. 9 schematically is data transceiver 401 deployed onto a person 450 which has been fitted with a headset 452 and also has a cell phone 454 . Headset 452 communicates with cell phone 460 with either a wired or wireless connection and can transmit and receive signals from cell phone 454 . Cell phone 454 is equipped with an on board phone app 460 also referred to as cell phone application 460 which can convert audio signals into digital data using voice recognition software and additionally can store any data points received.
Person 450 could press for example the record button 404 on tape measure attachment 400 and then speak into mic 456 which would then send a headset send signal 458 to cell phone 454 where it is processed by phone app 460 . Pressing of one of the record buttons 404 sends a tape signal 462 to cell phone 454 which is received by phone app 460 telling it to record the signal being received from the headset namely headset send signal 458 .
It is also possible that data transceiver 401 when in the form of a digital tape measure 403 may measure digitally measurements and by pushing the record button 404 a signal is sent to cell phone 454 with the digital measurement to be recorded and at the same time phone app 460 sends a phone send signal to headset 452 with an audio announcement of the measurement being recorded for verification purposes.
By depressing for example playback button 406 the phone app 460 is instructed to send a phone send signal 464 which is intercepted by headset 452 by wireless receiver 466 which in turn communicates the signal to ear buds 468 where the measurement previously made on the phone app 460 is now replayed audibly into the persons 450 ears.
FIG. 10 shows the interaction between two users namely a first person 550 and a second person 552 each having a headset 554 which includes a mic 556 and ear buds 558 . In addition each person also has a tape measure attachment 400 shown as first tape 506 and second tape 526 which communicates to respective cell phones namely first phone 508 and second phone 528 .
In similar fashion as previously described for a single person user first person 550 for example could make a recording by pushing record button 1 404 which sends a first tape signal 504 to cell phone telling it to record the measurement that will be received from headset 554 as headset sends signal 502 .
With the user selector 416 in the H position by pressing on the playback button 406 this commands the first phone 508 to send a phone send signal 504 to headset 554 thereby replaying the measurement that was recorded with record button 1 404 .
In this example if the user selector 416 is for example in the 2 position and second user 521 has been assigned the number 2 position then in addition to first person 550 hearing the recorded measurement also second user 521 will also hear the recorded measurements since first phone 508 is now instructed to send a phone send signal 504 not only to headset 554 but also onto second phone 528 which will then further send on the measurement to second person 552 via phone send signal 540 as shown in FIG. 2 .
Therefore by moving user selector 416 to various positions up to a total of five users the information that first person 550 is storing on his first phone 508 can be shared with any one of the other five users by simply moving the user selector knob 416 to correct position.
Secondly second user 521 shown as second person 552 can also make recordings on his second tape 526 which will send a second tape signal 524 to his second phone 528 which in turn can be reviewed by second user 521 with a phone send signal 520 or the signal can be sent on to for example first person 550 by selecting position number 1 in the case that person has been assigned position number 1 or to some other position such as third phone 530 which may be assigned user selector 416 knob position number 3 .
Therefore the reader will note that information that is stored by any of the tape measures namely first tape 506 , second tape 526 , and up to five separate tapes; this information can be replayed back to the user of that particular tape and/or the information on that tape can be sent on to any of the other users by selecting the appropriate user selector position 416 .
Additionally all of the linked users 1 through 5 can also talk with each other in walkie-talkie fashion by simply selecting the user you wish to talk to by moving user selector knob 416 to the proper position and then pushing the walkie-talkie button 418 and speaking into the mic 556 .
Therefore in this example first user 501 for example could with the user selector knob into the number 2 position which corresponds to second user 521 and push the walkie-talkie button 418 and then begin speaking to second user 521 in walkie-talkie fashion.
Additionally by pushing the calculate button 408 one is able to record by voice a calculation that one would like the app to carry out for example 25.5+32.25.
By pushing the respond button 410 the app is prompt to respond with an answer to the user through the headset 554 .
Additionally it is possible to download drawings onto the phone app 416 by pressing on the drawing button 412 this would illuminate the LED projector light 414 and the drawings would be projected onto any flat surface.
Additionally and referring now to FIG. 11 cell phone 534 for example which contains phone app 536 will record a log of all of the measurements that have been recorded over time and create data log 532 as shown schematically in FIG. 11 .
FIG. 12 shows schematically how a LED projector light 414 could for example project drawings onto a flat surface.
It is also possible to use a digital tape measure which directly converts the tape position into digital measurement data thereby skipping the voice recording of the measurement. In this case the transceiver would send the digital data from the tape measure directly to the cell phone.
It should be apparent to persons skilled in the arts that various modifications and adaptation of this structure described above are possible without departure from the spirit of the invention the scope of which defined in the appended claim. | The present invention is a tape measure in combination with a data transceiver, a headset, and a cell phone. The invention includes a data transceiver with a housing that can be mounted to a tape measure, where the housing features numerous selectors including at least one record button and one playback button. The present invention further involves the transceiver in communication with a first user cell phone for instructing recordation of verbal analog data received from a head set when a record button is depressed. The cell phone also includes an application for converting verbal information into digital data using voice recognition software, communicating and storing the digital data, and communicating analog data. The present invention alternatively allows for playback of the recorded data to the headset when a playback button is depressed. Another embodiment allows for communication between the cell phones of a first and a second user and an associated headset. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to an insulating joint for metal pipepines.
Insulating joints for metal pipelines are universally known. The joints serve the purpose of interrupting the electric continuity in a pipeline by interrupting the continuity of the metal. When the insulating joints are to be used on small diameter pipelines involved in conveying fluids towards several points for their use conventionally referred to as consumers, the pipelines have to withstand low pressure and are subjected to limited mechanical stress. The tendency here is to procure the most economical insulating joints. The insulating joint is essentially a special tubular piece composed of two tubular metal parts which are mechanically and soundly connected with one another but reciprocally and electrically isolated from each other through the interposition of dielectrical and sealing parts. The construction of such insulating joints and the work involved are far from being simple, since the joint has to possess mechanical and electrical characteristics such as to endow it with elevated working reliability. The overstressed general tendency of procuring low cost insulating joints has forcefully induced the market to present poor-quality joints with a consequential lack in reliability.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an insulating joint for metal pipelines which avoids the disadvantages of the prior art.
More particularly, it is an object of the present invention to provide an insulating joint for metal pipelines which satisfies the requirements for the joint of acceptable reliability with low manufacturing costs.
In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in an insulating joint for metal pipelines which includes two tubular metal parts having dilated end portions and arranged so that the dilated end portion of one metal part is inserted into the dilated end portion of the other metal part, the dilated end portions extend parallel to one another with a gap therebetween, two sleeves composed of a rigid and slightly resilient insulating material forcefully introduced in said gap, and an O-ring compressed between opposing extreme edges of the sleeves.
When the insulating joint for metal pipelines is designed in accordance with the present invention, it has a required reliability and at the same time low manufacturing costs.
The dilated end portions of the metal tubular parts may have an elliptical cross-section. They may be formed so that the end portion of one of the tubular parts is located in the end portion of the other of the tubular parts, and the dilated end portions cannot dislodge relative to one another. The gap between the dilated end portions of the metal tubular parts may be equal to substantially a few millimeters.
The sleeves may be composed of a rigid and at the same time slightly resilient insulating material. They may have substantially the same length.
The gasket located between the two sleeves may be formed as an O-ring. The gasket may be composed of an elastomeric material.
At least one of the insulating sleeves may be glued to the respective one of the dilated end portions of the tubular parts. Of course, both insulating sleeves may be glued respectively to the dilated end portions of the tubular parts.
The end portions of the metal parts have metal surfaces which are in contact with the insulating sleeves, and at least some of the metal surfaces may be sand blasted, or lined with insulating paint.
The two tubular parts may be strongly compressed in a longitudinal direction and in a transverse direction against the two insulating sleeves. The metal tubular parts have end sections arranged to be connected with pipelines to be isolated.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing a cross-section of an insulating joint of metal pipelines in accordance with the present invention;
FIG. 2 is a view showing various components of the inventive insulating joint before their assembling and blocking; and
FIG. 3 is a view showing the insulating joint for metal in accordance with another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A prefabricated monolithic insulating joint for connecting metal pipelines includes a first metal tubular part which is identified with reference numeral 1 and has an end portion 2. The end portion 2 is progressively dilated from a point 2 (1) where the external diameter of the end portion 2 equals to the external diameter of the pipe, to the point 2 (2) where the external diameter of the end portion 2 is greater by a few millimeters than the external in the point 2 (1) for a predetermined stretch. From the point 2 (2) the diameter of the end portion 2 starts shrinking progressively for more or less a similar stretch as above, until it reaches a point 2 (3) in which it has approximately the same external diameter as in the point 2 (1).
The insulating joint further includes an another metal tubular part 3 which has an end portion 4. The end portion 4 progressively dilates for a predetermined stretch from a point 4 (1) where it has the internal diameter equal to the internal diameter of the tubular part 3, until reaching a point 4 (2). The internal surface of this first stretch of the end portion 4 is formed so that when the insulating joint in accordance with the present invention has been assembled, it runs parallel to the external surface of the second stretch of the end portion 2 of the tubular part 1 so as to form a spacing or gap of a few millimeters between the opposite surfaces of the end portions of the tubular parts 1 and 3. From the point 4 (2), the end portion 4 extends over another predetermined stretch and terminates in a point 4 (3) after a very slight flare.
The insulating joint in accordance with the present invention is further provided with a sleeve 6 which is composed of a rigid, insulating material resistant to the most elevated mechanical stress but nevertheless capable of withstanding breakage during its slight and permanent deformation, so as to have a stability under the compression needed to block the joint. The sleeve 6 has an external surface which is formed to fit forcefully and perfectly with the internal surface of the first stretch of the end portion 4 of the tubular part 3, and an internal surface which is formed to fit forcefully and perfectly with the external surface of the second stretch of the end portion 2 of the tubular part 1. The sleeve terminates in an appendix 6 (1) which has an internal diameter more or less equal to the internal diameter of the tubular parts 1 and 3. The appendix 6 (1) is provided with a supporting surface 6 (2) which houses the terminal edge 2 (3) of the second stretch of the end portion 2 of the tubular part 1.
Furthermore, the insulating joint is provided with another sleeve 7 which is also composed of an insulating material. It can be the same as the material of the sleeve 6. The sleeve 7 is shaped so that its internal surface fits forcefully and perfectly with the external surface of the first stretch of the end portion 2 of the tubular part 1 and also with a short stretch of its main portion. The external surface of the sleeve 7 is parallel to its internal surface, and the sleeve thickness equal to the sleeve thickness of the sleeve 6.
Finally the insulating joint in accordance with the present invention has an insulating sealing, elastomeric gasket ring 8 of a O-ring type or any other suitable shape. The ring 8 has an internal diameter which is equal to the maximum external diameter of the end portion 2 of the tubular part 1 in the point 2 (2). Its external diameter is equal to the maximum internal diameter of the end portion 4 of the tubular part 3 in the point 4 (2).
For assembling the insulating joint for metal pipelines in accordance with the present invention, the insulating sleeve 6 is rammed into the end portion 4 of the tubular part 3. Then end portion 2 of the tubular part 1 with the gasket ring 8 and the insulating sleeve 7 positioned thereon is inserted into the end portion 4 of the tubular part 3. Finally, the second cylindrical stretch of the end portion 4 extending between the point 4 (2) and 4 (3) is plastically deformed obtaining a conformed portion 9 which is identified in FIG. 1 and runs parallel to the portion 2 of the tubular part 1.
During the assembling of the inventive insulating joint, some or all of the following conditions are to be considered.
The two insulating sleeves 6 and 7 are forcefully lodged in their respective seats, whether or not their surfaces are wet with a suitable hot or cold glue for their perfect adhesion to the opposing metal surfaces after plasticaly pressing the end portion 4 of the tubular part 3. Already in anticipation to the plastic pressing of the end portion 4, the gasket 8 is strongly compressed with the forcing of the sleeve 7 into its seat between the end portions 2 and 4. The metal surfaces in contact with the surfaces of the sleeves 6 and 7 are sand blasted. The internal surfaces of one or two tubular parts are lined with hot or cold polymerizing insulating paint or powder. Simultaneously or subsequently to the pressing of the stretch of the end portion 4 to obtain the closing and blocking of the joint as indicated in FIG. 1, the entire surface 9 is forcefully compressed longitudinally and radially so as to insure maximum compactness of the insulating joint. The deformation of dilated end portions of the two tubular parts is such that when the joint has been closed and blocked, the external diameter of the end portion 2 in the point 2 (2) is greater than the internal diameter of the end portion 4 in the point 4 (3).
The free ends of the metal tubular parts 1 and 3 can be either provided with a flange or with a bevel or male or female threading independently from each other so as to be fixed onto the pipeline at the location of insertion of the joint. The fixation can h=performed by welding, bolting, screwing, etc.
FIG. 3 shows another embodiment of the insulating joint in accordance with the present invention. In this joint two sealing gaskets 8 (1) and 8 (2) are provided and a ring 10 is located between them. The ring 10 preferably has a rectangular cross-section and is composed of a rigid, insulating material which can be similar to the material of the sleeves 6 and 7.
The sealing gaskets 8, 8 (1) and 8 (2) can be composed for example of nitril rubber. The sleeves 6 and 7 and the ring 10 can be composed for example of polycarbonate, thermoplastic amorphus.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in an insulating joint for metal pipelines, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | An insulating joint for pipelines comprises two metal tubular parts each having a dilated end portion, the dilated portion of one of the tubular parts being located within the dilated portion of the other tubular part and the dilated portions extending substantially parallel to each other so as to form a gap therebetween, two sleeves composed of an insulating material and forcefully introduced into the gap one after the other in a longitudinal direction so as to form a space therebetween, and a gasket located in the space and forcefully compressed between the two sleeves. | 5 |
FIELD OF THE INVENTION
The invention relates to a light fixture for illuminating steps and more specifically to a step light fixture that is aesthetically pleasing and easily maintained.
BACKGROUND OF THE INVENTION
Environmental lighting, particularly outdoor lighting, is well known in commercial or public settings such as parks, government buildings, schools and shopping centers. Such lighting is also popular in residential applications, both to enhance the appearance and safety of the outdoor area and for security, to illuminate dark areas around a building or in a yard which may provide hiding places and unobserved entry points for intruders.
One area that can be particularly problematic in both indoor and outdoor settings is stairs, steps and other abrupt changes in surface height, where proper illumination can be the difference between safe passage and injury. Stairs that are insufficiently lit or that are subject to shadows exhibit a safety and security concern, especially outdoors where the light oftentimes cannot be properly directed towards its desired area of use. For example, if the light source is located behind a person as they approach the steps, the person's shadow may make the steps difficult to see. On the other hand, light fixtures physically mounted to the stairs may also impose a danger because stray light or glare emitted from the fixtures may temporarily adversely affect a person's vision. In addition, protruding light fixtures may be subject to inadvertent damage and may even pose a risk of tripping. A common approach to dealing with this challenge is to install recessed fixtures in walls adjacent to the stairs. Examples of such fixtures are disclosed in U.S. Pat. No. 6,796,684 and No. 6,779,907. However, when there are no adjacent walls, or in existing construction where creating the necessary recesses involves significant cutting and drilling into masonry or stucco walls, such fixtures may not be practical.
Another approach to lighting stairs, illustrated in FIG. 1 , involves suspending a small lamp enclosure 10 from the edge of a flat plate 8 that is sandwiched between each step riser 4 and the cap stone 6 or other tread surface on top of the riser so that the lamp enclosure is positioned beneath the overhang of the tread, i.e., the “nose” 12 of the stair. This arrangement illuminates both the step riser and the step immediately below so that the edge of each step is illuminated whether one is walking up or down the stairway. Lighting systems of this nature are particularly useful in environments where the lighting level is low, such as in theaters and the like, where it is preferable to have minimal illumination directed upward. For existing construction where the stair tread is already attached to the riser, the plate 8 can be narrow and elongated for attachment solely on the underside of the nose.
The lamp enclosure of step lights typically includes a protective lens that is directed outward or downward from the underside of the stair nose. A closed fixture is particularly appropriate for installations in an outdoor setting, to make the fixtures substantially water-tight and resistant to contaminants, but also provides the fixture with a clean, finished appearance. Maintenance of the fixtures includes cleaning of the lenses and replacement of damaged or burned-out bulbs. Many step lights have a pair of screws, one on either end of the elongated cover that includes the lens, which must be removed in order to access the lamp(s) and lamp socket(s). Obtaining access for removal of the cover can often be awkward, requiring the person performing the maintenance to kneel on a lower stair with their head level with the target fixture in order to locate the screws. Even if the screws are neatly countersunk into the outer surface of the cover face, the exposed screws can ultimately become unsightly after repeated removals since the heads can become scratched and rusty. Avoiding this problem and providing a continuous, aesthetically-pleasing surface involves concealing the screws, possibly on the sides of the fixture housing, however, access to such screws can be particularly difficult in narrow passages where the sides are not easily visible. The screws may also be located on the face of the lens where the screw is accessed from underneath the fixture in a position that cannot be seen and is difficult to access. The small screws can also be easily dropped when trying to remove or replace them.
In view of the foregoing, the need remains for a step light fixture that is attractive and effective as well as easy to install and service.
SUMMARY OF THE INVENTION
It is an advantage of the present invention to provide a step light fixture that is aesthetically pleasing and easily maintained.
In an exemplary embodiment, a step light fixture includes an enclosure for retaining one or more socket and lamp combinations, a light transmissive lens, a cover for sealing the enclosure, and a mounting plate for attaching the fixture on an underside of a stair tread overhang. In a first embodiment, the cover is attached to the enclosure by a removable hinge at a first end that permits the cover to pivot its second end outward away from the enclosure to provide access to the interior of the enclosure. The second end of the cover includes a latch that mates with a corresponding catch on the side of the enclosure to releasably close the enclosure. The latch may be a tab that inserts into a slot, but preferably includes a spring locking clip that cams into a slot or over a ridge when pressed into a closed position. The cover remains closed until the spring clip is pulled outward away from the catch or a sufficient pulling force is applied to the cover to overcome the spring bias. An optional bore may be included in the latch for insertion of a locking screw to protect against vandalism or unauthorized opening of the enclosure.
In one aspect of the invention, a step light fixture comprises a support plate having means for attachment to a bottom surface of a stair tread, a frame extending from a bottom surface of the support plate with a first end and a second end so that the frame defines a back, a first side and a second side of a partial enclosure. A lamp and a lamp socket are enclosed within the partial enclosure with a lens disposed below the lamp socket and lamp. Lens supports extend from the bottom surface of the support plate. A front cover has a first end and a second end, each of the first end and the second end having a retainer that removably attaches the front cover to the first end and the second end of the frame. In a first embodiment, a different retainer is used for each end of the cover. The first end retainer is a removable hinge comprising a bent tab that inserts into a slot in the first end of the frame. The second end retainer is a spring clip that cams into a recess or slot, or over a ridge, formed in the second end of the frame.
In a second embodiment, the same type of retainer, a spring clip, is formed on both ends of the cover to snap into corresponding slots or recesses in the sides of the enclosure. This allows the cover to be removed completely for maintenance. Optional bores may be provided at each end to prevent unauthorized opening of the fixture.
Additional embodiments comprise different combinations of retainers. In one embodiment, the first end retainer is a releasable hinge while the second end retainer is a screw, bolt, pin or other removable fastener that is inserted through corresponding openings in the cover and frame end to releasably close the fixture. In another embodiment, the both retainers are removable fasteners that may be inserted through openings in the cover and frame.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more clearly understood from the following detailed description of the preferred embodiments of the invention and from the attached drawings, in which:
FIG. 1 is a partially exploded side elevation of stairs with prior art step light fixtures.
FIG. 2 is a perspective view of a first embodiment of a step light fixture according to the present invention.
FIG. 3 is a partially exploded perspective view of the embodiment of FIG. 2 .
FIG. 4 is a front elevation of the embodiment of FIG. 2
FIG. 5 is a cross-sectional view taken along line 5 - 5 of FIG. 4 .
FIG. 6 is a detail view of the hinged end of a cover.
FIG. 7 is a detail view of the spring clip of a cover.
FIG. 8 is a perspective view of the embodiment of FIG. 2 with the cover open.
FIG. 9 is a front elevation of the embodiment of FIG. 2 with the cover open.
FIG. 10 is a perspective view of a second embodiment of the step light fixture with two spring clip retainers for attachment of the cover.
FIG. 11 is a first perspective view of a third embodiment of the step light fixture with a screw fastener as a retainer.
FIG. 12 is a second perspective view of the third embodiment.
FIG. 13 illustrates an alternative arrangement of the latch-type retainer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 2-8 illustrate a first embodiment of the step light fixture according to the present invention. For purposes of this description, reference to a “stair tread” will include any surface in a structure having a general configuration of a stair tread including a partial overhang under which a light fixture may be attached. In this exemplary embodiment, the mounting plate 28 may be attached to the bottom of a stair tread using fasteners inserted through openings 34 so that the mounting plate 28 is sandwiched between the bottom surface of the stair tread and the upper portion of the stair riser. Where the stair tread is a material that does not easily accept a fastener, such as stone, the mounting plate 28 can be sandwiched in a mortar or other adhesive between the upper portion of the stair riser and the stair tread without the use of other fasteners.
Attached to and extending downward from the bottom surface of mounting plate 28 is a lamp enclosure formed from the combination of frame 50 , lens 22 and front cover 24 . A lip 25 may be formed in the front edge of the mounting plate. Frame 50 , which is fixedly attached to mounting plate 28 , defines the back and sides of the enclosure, as well as providing support for the reflector 42 , lamp socket 38 and lamp 36 . Lens support tabs 27 provide an upper confinement of lens 22 , while two L-shaped brackets 23 extend downward from the bottom surface of mounting plate 28 to provide a lower support for lens 22 , which sits below the lamp and socket and reflector so that light is projected downward. Reflector 42 is positioned above the lamp and socket to direct light downward. Reflector 42 is held in position between one of the brackets 23 and bracket 33 , while the socket 38 is held in place by the opening 43 in reflector 42 , which extends downward from the bottom surface of the mounting plate 28 . Wires 39 , which pass through an opening in each of reflector end 43 and bracket 33 , provide electrical connection to a wire or cable (not shown) and a power source. A typical power source will be a transformer that is commonly used with low-voltage outdoor lighting systems, but may also be other sources such as a 120 VAC outlet or a battery, that may, for example, be connected to a solar photovoltaic panel. Sufficient slack should be provided in the wires 39 to allow the socket and lamp to be pulled a short distance from the fixture without risking damage to the wires.
Frame 50 has side portions 40 and 44 which are perpendicular to the back wall to define enclosure sides that support the front cover 24 . Frame 50 may be formed from a metal, such as steel or steel alloys, aluminum, stainless steel, brass, copper, or other metals that are commonly used in the manufacture of lighting fixtures. A steel or steel alloy or aluminum may be powder coated for protect against corrosion and provide an aesthetically pleasing appearance. Front cover 24 may be made from any of the metals used for the frame 50 , but preferably will have an attractive finish, such as powder coating or anodization, or a metal such as brass or copper, which may be coated to maintain the metal's shine or may be allowed to oxidize or patina. Alternatively, the frame and front cover may be formed from an impact resistant plastic or polymer.
The following description may refer to a first or right side and a second or left side to correspond to the fixture as illustrated in the drawings. It will be readily apparent that the inventive fixture is not limited to the relative positions of left and right and that the right and left components may be reversed. Thus, reference to a left or right side in the following description is for ease of illustration and is not intended to be limiting.
The left side portion 44 has a slot 46 formed therein for mating with a curved hinge tab 48 that is formed at the left end 26 of front cover 24 . The curvature of tab 48 allows the tab to function as a hinge when inserted into slot 46 , so that the right end of cover 24 can be swung outward away from the frame 50 . The combination of tab 48 and slot 46 defines a first type of retainer that releasably attaches the cover to the frame. Because there is no fixed attachment means such as a hinge pin, the cover 24 can be completely removed by pulling tab 48 out of slot 46 . The hinge function of tab 48 is illustrated in FIG. 8 , which shows the fixture with the front cover 24 pivoted outward in an open position, with tab 48 shown extending through the opening in side portion 44 . An alternative arrangement of the hinge would reverse the relative locations of the tab and slot, so that the slot is formed in the end of the front cover and the curved tab extends outward from the side of the frame to define a pivot point for the cover.
At the right end portion of the cover 24 , a latch is formed so that it mates with a corresponding catch on the side of the enclosure to define a second type of retainer for releasably closing the enclosure. The latch may be a tab that inserts into a slot, but preferably includes a spring locking clip 30 that has a ridge portion that cams into a recess or slot 41 in frame side portion 40 when pressed into a closed position. Alternatively, the ridge portion of the spring locking clip can be captured behind a corresponding ridge formed on the frame side portion once the ridge portion of the clip cams over the ridge on the frame. The cover 24 remains closed until the spring clip 30 is pulled outward away from the catch 41 or a sufficient pulling force is applied to the cover to overcome the spring bias. Optional bores 31 and 54 may be included in the latch 30 and side portion 40 , respectively, for insertion of a conventional removable fastener 32 , for example, a locking screw, pin or bolt to protect against vandalism or unauthorized opening of the enclosure. In an alternate arrangement of the latch-type retainer, illustrated in FIG. 13 , a spring clip 152 with ridge 154 may be attached to the second side 150 of the frame so that it extends forward to cooperate with a ridge or slot 160 formed in an extension 162 on the end of the front cover 164 . In this configuration, the leading edge of extension 162 will cam the spring clip 152 outward until the ridge 154 on the spring clip snaps into slot 160 in the extension to releasably lock the cover in place.
In a second embodiment of the fixture, shown in FIG. 10 , the same basic structure as described above is modified so that front cover 124 has a spring locking clip 130 formed at both ends of the cover. Thus, in this embodiment, the same type of retainer is used at both ends of the cover. The spring locking clips 130 mate with corresponding slots or ridges formed in sides 140 and 144 of the frame. For replacement of the lamp, the entire front cover 124 may be pulled away from the frame by pulling one of the clips 130 away from the frame.
A third embodiment of the fixture is illustrated in FIGS. 11 and 12 . In this embodiment, the first end 244 of cover 224 has a retainer in the form of a hinge defined by a tab and slot to allow the cover to be swung out away from the frame, as described above with reference to the first embodiment. The second end 230 of the cover is formed without a spring clip, so that the end 230 is a simple lip that is parallel to frame side portion 240 . In this embodiment, the retainer is a conventional removable fastener 232 such as a screw, pin, bolt or other similar fastening means that is inserted through end 230 and into side portion 240 to hold the cover in a closed position.
The step light fixture incorporating the attachment means described above is easily maintained while providing an aesthetically pleasing “clean” finish on the visible portion of the fixture.
The foregoing description of preferred embodiments is not intended to be limited to the specific details disclosed herein. Rather, the present invention extends to all functionally equivalent structures, methods and uses as fall within the scope of the appended claims. | A step light fixture includes an enclosure for retaining one or more socket and lamp combinations, a light transmissive lens, a cover for sealing the enclosure, and a mounting plate for attaching the fixture on an underside of a stair tread overhang. In a first embodiment, the cover is attached to the enclosure by a removable hinge at a first end that permits the cover to pivot its second end outward away from the enclosure to provide access to the interior of the enclosure. The second end of the cover includes a latch that mates with a corresponding catch on the side of the enclosure to releasably close the enclosure. | 4 |
RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent Application No. 61/023,492 filed on Jan. 25, 2008, and entitled SIMPLIFIED METHOD AND APPARATUS FOR CARRYING OUT LIMITED TWO DIMENSIONAL SEPARATION OF PROTEINS AND OTHER BIOLOGICALS, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention is in the technical field of two-dimensional separation of proteins and other biologicals and relates particularly to apparatus and a method for the rapid and reproducible separation of species in a liquid medium.
[0003] The separation and characterization of proteins is ubiquitous throughout the life sciences. Two of the most popular electrophoresis separation techniques are: 1) gel isoelectric focusing (IEF), where the separation mechanism is based on protein surface charge providing isoelectric point (pI) separation and 2) sodium dodecyl sulfate (SDS) gel electrophoresis where the separation mechanism is based on molecular weight (MW). These two techniques are most commonly performed individually.
[0004] Isoelectric focusing (IEF) is a special electrophoretic technique for separating amphoteric substances such as peptides and proteins in an electric field, across which there is both voltage and a pH gradient, acidic in the region of the anode and alkaline near the cathode. Each substance in the mixture will migrate to a position in the separation column where the surrounding pH corresponds to its isoelectric point. There, in zwitterion form with no net charge, molecules of that substance cease to move in the electric field. Different amphorteric substances are thereby focused into narrow stationary bands.
[0005] In IEF separation, it is well known that proteins having molecular weight differences or conformational differences may possess similar pI values and therefore focus at the same location. In order to then separate these co-focused proteins, a technique called two-dimensional (2D) gel electrophoresis has been employed. 2D gel electrophoresis combines two orthogonal separation techniques—gel IEF and SDS gel—to create a technique that dramatically increases separation resolution and provides for the separation of co-focused IEF protein zones. 2D gel electrophoresis is generally carried out in a polyacrylamide slab gel and although it has become a workhorse in the field of proteomics, owing to the high degree of resolution which can be obtained thereby, it is very labour-intensive, time consuming and non-quantitative.
[0006] Moreover, although 2D gel electrophoresis does afford the highest degree of molecular weight resolution of known electrophoretic separation techniques, it has not yet been possible to automate that process nor quantify the resolved component proteins or other analytes. These and other drawbacks have motivated researchers to combine two orthogonal separation techniques in the liquid phase, using a capillary or coplanar microchannel format. While these are necessarily “limited resolution” techniques, relative to 2D gel electrophoresis, they are much simpler and faster to use and are of adequate resolution for many purposes.
[0007] It is known to combine capillary or channel isoelectric focusing (cIEF) with non-porous reverse phase microliquid chromatography (RPLC) in a two-dimensional layout, to obtain useful online detection and quantitation. However, the interface between the first and second separation dimension has hitherto been carried out only at the outlet end of the IEF separation capillary or channel. It is known that the separation and pH gradient obtained in cIEF may be disturbed when mobilizing focused protein zones to reach the outlet end. A as result, it is more challenging to transfer separated zones from the first separation dimension to the second separation dimension in the orthogonal capillary or microchannel format than in apparatus for 2D gel electrophoresis. Fluid connections and for control of nanoliter volumes are required, making for complex analytical design and operation.
BRIEF SUMMARY OF THE INVENTION
[0008] This invention describes improved method and apparatus for carrying out limited electrophoretic separation in the liquid phase. The objective of the invention is to provide a simple method and apparatus for limited “2D” separation using both capillary or channel IEF separation and capillary zone electrophoresis (CZE) separation within the same capillary or channel. The present invention also integrates real-time, whole-channel electrophoresis detection with automatic sample injection, automatic cIEF separation, separation zone manipulation and on-line electrolyte selection, to achieve a separation resolution superior to that obtained using an orthogonal capillary arrangement.
[0009] The quotation marks about “2D” above reflect the fact that the present invention uses two different and sequential electrophoretic techniques, but not orthogonal capillaries as in the known arrangements described above. The term “2D” is, a convenient shorthand term for designating a method and apparatus employing two-stage electrophoretic separation, and will be used in the remainder of the specification and in the claims without quotation marks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic representation of a first embodiment of apparatus for performing limited 2D separation using electrophoresis and controlled hydrodynamic flow.
[0011] FIG. 2 illustrates schematically a physiochemical mechanism postulated to explain the separation of proteins in the presence of a hydrodynamic flow as in the method of the invention.
[0012] FIG. 3 is a schematic representation of a second embodiment of apparatus according to the invention for performing limited 2D separation using electrophoresis and chemical mobilization.
[0013] FIG. 4 illustrates graphically the separation of two proteins having the same pI value but different charge responses to pH, using the method of the invention.
[0014] FIG. 5 illustrates graphically the results of a separation effected by using apparatus according to the first embodiment of the invention, showing a single peak of tryptosinogen and pI Marker 9.46 mixture when hydrodynamic flow is minimized, and split peak of tryptosinogen and pI Marker 9.46 when hydrodynamic flow is toward the cathode.
[0015] FIG. 6 illustrates graphically the results of a separation effected by apparatus according to the second embodiment of the invention, showing two peaks of transferrin prior to anodic mobilization and four peaks of transferring subsequent to anodic chemical mobilization.
DETAILED DESCRIPTION OF THE INVENTION
[0016] FIG. 1 shows a first embodiment of the apparatus. A microfluid device is provided, including an anolyte tank 10 and a catholyte tank 12 such that electrolyes in the tanks are isolated from the sample mixture by ion conductive barriers 14 (such as semipereamble membranes). A high voltage supply connected across two electrodes that are immersed in the respective tanks. A CCD imaging camera 20 is focused so that it can detect light passing through or emitted from the entire length of a horizontal capillary separation channel 22 . The camera 20 is able to display and capture pictures in real-time, or at least very rapidly. A light source and collimation means (not shown) are provided for applying a sheet of light (arrows L) to pass through or emit from the entire length of separation channel 22 . A real time CCD sensor camera/sensor arrangement like that used with the apparatus of the present invention is described in more detail in U.S. Pat. No. 6,852,206, having a common inventor and the same assignee as the present application. U.S. Pat. No. 6,852,206 is hereby incorporated by reference for its disclosure of detection and measurement apparatus of analyte separation zones in a capillary.
[0017] A switch valve 24 is connected to the microfluidic device such that an inlet flow channel portion 26 at one end of the separation channel may be selectively connected to either an autosampler 28 for sample injection, or to the fluid medium contents of an inlet vial 30 . A hydrodynamic flow across separation channel 22 can be induced and controlled by vertical up or down fine-control motion of a hydrodynamic flow vial 32 containing fluid medium, the contents of which are connected by means of hydrodynamic flow control valve 33 with an outlet flow channel portion 34 of the separation channel.
[0018] With the switch valve 24 position set for fluid connection of the inlet channel portion 26 of the separation channel to the autosampler 28 , and with a shut-off valve for autosampler connection tube 29 open, a sample containing a mixture of proteins, carrier ampholytes and a sieving solution such as methyl cellulose is injected into the separation channel by the autosampler until the sample mixture volume fills the separation channel to overflow. The position of the switch valve is then set to connect the inlet vial with the separation channel and the high voltage is turned on by means of HV switch 36 . An electric field is thereby established across the separation channel and a linear pH gradient is formed by the carrier ampholytes. The cIEF process begins and upon completion, proteins are focused and separated into zones according to their pI when both electro-osmotic flow and hydrodynamic flow are stable. The entire IEF process is continuously monitored and the images of the separation trace are continuously captured (recorded) in real-time by the whole-channel CCD imaging camera of the CCD sensor unit. At this point, the first dimensional separation (cIEF) is complete and the second dimensional separation is initiated.
[0019] The second dimensional separation is applied to the IEF focused zones (proteins) by the application of a controlled hydrodynamic flow. The hydrodynamic flow is induced by a microgravitational force arising in the separation channel 22 resulting from the finely controlled up or down motion of the hydrodynamic flow vial. When hydrodynamic flow is introduced into the separation channel following IEF focusing, the pH gradient will be affected and additional sample mixture will enter the separation channel. As more sample mixture is continuously injected into the separation channel owing to the hydrodynamic flow, the focused zones at the far end of the separation channel (along the direction of hydrodynamic flow) are continuously pushed out. For example, if the outlet vial 32 is raised slightly, then the hydrodynamic flow direction proceeds from the anodic (outlet end) to the cathodic end (inlet end). More sample mixture is introduced from the anodic end, and the most basic zones focused at the cathodic end will be pushed out of the separation capillary (over the ion conductive barrier area, see FIG. 2 ). Since this hydrodynamic flow coexists with an electric field, the separation zone resolution and shape is preserved when the hydrodynamic flow is limited and carefully controlled and the newly injected sample mixture ampholytes are focused into their pI position. The movement of relatively larger molecular weight proteins (protein A in FIG. 2 ) is slower than that of smaller ones (protein B in FIG. 2 ) in a sieving solution such as methylcellulose. As a result, a limited second dimensional separation of cIEF zones (proteins) due to mass difference is achieved. Again, the entire second dimension separation process is continuously monitored and the images of the separation trace are continuously captured (recorded) in real-time by the whole-channel, CCD imaging camera.
[0020] FIG. 3 shows a second embodiment of the apparatus. The same reference numerals are used to indicate components corresponding to those of the first apparatus embodiment ( FIG. 1 ). The microfluid device contains an analyte tank 10 , a catholyte tank 12 and a chemical mobilization tank 38 . The electrolyes in the three tanks are isolated from the sample mixture by ion conductive barriers 14 . High voltage supply is connected at one end to an electrode immersed in the anolyte tank and at the other end to HV switch 36 such that connection can be made to either an electrode immersed in the catholyte tank or an electrode immersed in the chemical mobilization tank. Real time CCD sensor 20 is focused such that it can detect light (arrows L) passing through or emitted from the entire length of separation channel 22 and the camera is able to display and capture pictures in real-time, or at least very rapidly. Means (not shown) are provided in both the first and second embodiments of the invention for projecting a sheet of light to pass through or emit from the entire length of the separation channel. As with the first embodiment described above switch valve 24 is connected to the microfluidic device such that the inlet flow channel 26 may be connected to either autosampler 18 for sample injection or to an inlet vial 30 . The end of the outlet channel is immersed in an outlet vial.
[0021] The anolyte, catholyte and chemical mobilization tanks ( 10 , 12 , 38 ) are filled with appropriate electrolytes and, with the switch valve position set for connection between the inlet of the separation channel and the autosampler and the shut-off valve to capillary section 29 open, a sample containing a mixture of proteins, carrier ampholytes and a sieving solution such as methyl cellulose solution is injected into the separation channel by the autosampler until the sample mixture volume fills the separation channel to overflow. The switch valve position is then set for connection between inlet vial 30 and separation channel 22 , the high voltage is turned on and the switch valve 24 is set such that the catholyte electrode is contacted, an electric field established across the separation channel, and a linear pH gradient is formed by the carrier ampholytes. The cIEF process begins and upon completion, proteins are focused and separated into zones according to their pI when both electro-osmotic flow and hydrodynamic flow are well controlled. The entire cIEF process is continuously monitored and the images of the separation trace are continuously captured (recorded) in real-time by the whole-channel, CCD imaging camera. At this point, the first dimensional separation (cIEF) is complete and the second dimensional separation begins.
[0022] The second dimensional separation is achieved in this second embodiment of the apparatus, not by controlled hydrodynamic pressure but by chemical mobilization of the cIEF focused zones. An electric switch that is selectively operable to connect to anolyte electrode or the catholyte electrode is changed to connect to the chemical mobilization solution upon completion of cIEF. Mobilization of the focused zones will then occur. It is known that when non-acid solution is used as the anolyte, focused cIEF zones will migrate towards the anode (anodic mobilization). Whereas when non-base solution is used as the catholyte, focused cIEF zones will migrate towards the cathode (cathodic mobilization). Therefore, anodic mobilization may be achieved by switching the high voltage contact to the anode from the acid solution tank to the chemical mobilization tank that contains non-acid solution, or cathodic mobilization may be achieved by switching the high voltage contact to the cathode from the base solution tank to the chemical mobilization tank that contains non-base solution.
[0023] The rate of migration due to chemical mobilization is determined by the charge-to-mass ratio of the protein and the mobility of the protein in a specific sieving solution. For example, two exemplary proteins with the same pI value have different rates of migration in response to a pH change ( FIG. 4 ). As a result, these two proteins will not experience the same rate of motion during chemical mobilization. In addition, when this movement is carried out in a sieving solution, proteins with different molecular weight or shape (conformation) may have different mobility. Therefore, proteins with the same pI, but have different mobility change with pH or different molecular weights or conformation can be separated with limited 2 D separation of cIEF zones using chemical mobilization. Again, the entire second dimension separation process is continuously monitored and the images of the separation trace are continuously captured (recorded) in real-time by the whole-channel, CCD imaging camera.
[0024] cIEF is a steady state technique. Focusing and separation of proteins is achieved when transitional peaks or zones converge into stationary zones. However, if single-point detection is used, it is difficult to know the exact time when all proteins are focused, since the speed of protein focusing is affected by sample conditions such as: content of salt and carrier ampholytes in the sample, experimental conditions such as separation channel dimensions, electric field strength and electrolyte concentration. As a result, two transitional peaks or zones for one protein may be detected when the protein is not yet focused. Further, an abnormal peak may be observed due to protein aggregation or precipitation resulting from prolonged protein focusing. With whole-column detection, as used with the present invention, however, the separation and focusing of an individual protein can be monitored in real time, avoiding the problems of 2D separation of transitional peaks (premature focusing) and separation of precipitated proteins (over focusing). The pI value of the protein is calibrated and the second dimension separation is applied. With real-time, whole column detection, the protein separation can be monitored, providing better protein fingerprinting by allowing straightforward assignment of protein zones based on pI and relative molecular weight differences.
Example 1: Induced Hydrodynamic Flow as Second Dimension of Separation
[0025] FIG. 5 illustrates hydrodynamic flow induced limited 2 D separation of protein trypsinogen and a small molecular weight pI marker. In this experiment, trypsinogen and a small molecular pI marker were mixed with 8% pH 3-10 Pharmalyte and 0.35% methylcellulose. The sample mixture was injected into a 50 mm 100 μm inner diameter FC coated capillary with a micro autosampler. Focusing was conducted at a focusing voltage of 3000 V, with 80 mM H 3 PO 4 as anolyte and 100 mM NaOH as catholyte. Detection was conducted with a real-time, whole column UV detector. The hydrodynamic flow is controlled by the water level difference in the hydrodynamic flow vial and the inlet vial.
[0026] It can be seen that when hydrodynamic flow was minimized (i.e. under first dimension cIEF separation conditions), there were two peaks in the electrophorogram (trace a). The more acidic peak to the left of the electrophorogram (egram) contains the minor component of trypsinogen (pk 1 ) and the more basic peak to the right of the egram contains the major component of trypsinogen (pk 2 ) and the pI marker (pk 3 ). When a hydrodynamic flow was introduced in the direction of the cathodic end (trace b), the minor component of trypsinogen (pk 1 ) further partially separated into two subcomponents, and the pI marker (pk 3 ) was partially separated from peak the major component of trypsinogen (pk 2 ). The pI marker (pk 3 ) moved more quickly to a more basic position than the major trypsinogen component (pk 2 ) due to its smaller molecular weight in a sieving solution. When a hydrodynamic flow was introduced in the direction of the anodic end (trace c), again because of the smaller MW of the pI marker (pk 3 ) compared to that of the major component of trypsinogen (pk 2 ), the pI marker shifted more quickly to a more acidic position than that of the major component of trypsinogen.
Example 2: Chemical Mobilization as Second Dimension of Separation
[0027] FIG. 6 illustrates chemical mobilization induced limited 2D separation of transferrin, myoglobin and a small molecular weight pI marker (pI 4.22). In this experiment, transferrin and myoglobin and the pI marker were mixed with 8% pH 3-10 Pharmalyte and 0.35% methylcellulose. The sample mixture was injected into a 50 mm 100 μm inner diameter FC coated capillary with a micro autosampler. Focusing was conducted at a focusing voltage of 3000 V, with 80 mM H 3 PO 4 as anolyte and 100 mM NaOH as catholyte. Detection was conducted with a real-time, whole column UV detector. For anodic mobilization (trace b), the anolyte was replaced with 100 mM NaOH upon completion of cIEF focusing. For cathodic mobilization (trace c), the catholyte was replaced with 80 mM H 3 PO 4 upon completion of focusing. In Trace a, it can be seen that when electroosmotic flow and hydrodynamic flow are well controlled (i.e. under first dimension cIEF separation conditions), the transferrin protein is partially resolved into two peaks and a minor myoglobin peak (pk 1 ) is noted. Under anodic mobilization (trace b), the transferrin protein is now partially resolved into 4 peaks and the minor myoglobin component is partially resolved into 2 peaks (pk 1 ). When cathodic chemical mobilization was introduced (trace c), the two peaks of transferrin (trace a) are separated into two larger peaks and one smaller peak.
[0028] Neither chemical mobilization conditions produced any split or partially separation of the pI marker peak (pI 4.22) and the major myoglobin peak.
CONCLUSION
[0029] From the description and examples herein it will be seen that applicants' provides a rapid, reproducible and quantative limited 2D electrophoresis separation. Channel or capillary-based electrophoresis, unlike 2D gel electrophoresis permits automatic sample injection. No sample transfer or handling is involved and either hydrodynamic flow or chemical mobilization can be used, since both can be well controlled. Applicants' arrangement allows “two-dimensional” electrophoresis to be carried out within a single separation channel and in a single analysis run. The use of real time, whole channel image detection affords very good reproducibility in both qualitative and quantative characterization.
[0030] While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention as claimed. | A method and apparatus are provided for performing capillary isoelectric focusing followed by mobilization of the focused zones by induced hydrodynamic flow or chemical mobilization. These two dimensions of separation are integrated with real-time whole-channel electrophoresis detection and automatic sample injection to achieve a separation resolution superior to that obtainable using known orthogonal capillary two dimensional arrangements. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of synthesis of β-lactam antibiotics.
2. Discussion of the Background
It has long been known that beta-lactam antibiotics can be formed from their respective nucleus and side-chain components via enzymatic pathways (C. A. Claridge et al., Nature, Vol. 187;237, 1960).
From more recent studies it is known that a beta-lactam antibiotic, for example amoxicillin, synthesized via enzymatic pathways, has higher purity and accordingly lower toxicity than amoxicillin synthesized by chemical pathways (PCT WO 94/17800).
The general interest for industrially practical processes for enzymatically synthesizing beta-lactam antibiotics is correspondingly great.
In order to achieve this objective, a series of technical problems must be overcome or needs fulfilled, especially:
a) The need to maximize the desired synthesis reaction catalyzed by the enzyme and to minimize the undesired side reactions catalyzed by the same enzyme, such as hydrolysis of the activated side-chain components and of the beta-lactam antibiotic (see the reaction mechanism below).
Reaction mechanism
b) The need to isolate the product in a way which permits reuse of the biocatalyst, or, in other words, the enzyme.
Even now are numerous patent applications which have already been published, as well as patents granted, which claim decisive advances in solving these problems and which are based on experimental findings obtained with enzymes immobilized on insoluble carrier particles, usually covalently; in other words with systems, developed in the most recent decades, for reuse of enzymes.
It is, therefore, self-evident that the operational stability (O-ST) of these immobilized enzymes must be studied under practical conditions, in order to obtain an appraisal of the industrial productivity of such a biocatalyst.
In most cases, however, investigators have been satisfied with a minimum of tests, namely with testing of a single batch.
The result obtained in this way was then often generalized in a global claim, without regard to a fact well-known to the experts, that a result obtained from only a single batch is usually misleading for characterization of an immobilized enzyme and a reaction catalyzed thereby, specifically for the following reasons:
1. The activity measured for the first use of a covalently immobilized enzyme is usually much too high, because free enzyme is often still present. This free enzyme is adsorbed non-covalently on the support material, thus giving a false impression of higher activity of the “immobilized” enzyme, specifically until it has been eliminated by interaction with the substrate and by washing processes, such elimination lasting at least one cycle of use and usually several cycles.
In this connection, it must be recalled that immobilized enzymes are employed mainly because of their ready reusability, or in other words, their usability over many batch cycles, and because of the purity of the products which have been synthesized under these conditions.
The purity laws automatically preclude contamination by free enzyme; therefore, the product from the first batch should not be used in any case for the synthesis of pharmaceuticals.
2. Substrate and product molecules can be adsorbed on the support material on which the enzyme is covalently immobilized, and thus can elude analytical determination thereby falsifying the balance between synthesis and hydrolysis reactions.
This phenomenon is relevant in particular for the first batch. Thereafter a kind of stable state is established by saturation of the adsorbing support surface. In this context, analytical methods which consider only the dissolved constituents are misleading. In order to achieve a correct balance, only methods which permit solubilization of all molecules present should be used.
3. The immobilized enzyme almost always loses activity in the course of its use, but especially during the first three cycles of use.
For all of these reasons it is advisable to run at least four successive batch cycles in order to obtain a somewhat correct estimate of product yield, degree of conversion of the reaction and O-ST of the biocatalyst.
The test methods must obviously be significant, meaning that the product must be isolated if possible and its composition must be studied by, for example, HPLC or NM R. Samples taken from the heterogeneous product or reaction mixture must be solubilized before they are tested.
These rules have not been followed, however, in most of the patent applications and granted patents. To the knowledge of the present inventors, there is currently only a single application (PCT WO 96/23897, Chemferm, Boesten ct al.) which provides data on the O-ST of the biocatalyst obtained by testing of five successive batch cycles, with a degree of conversion of about 40% of the nucleus components.
Another critical aspect in the field of enzymatic synthesis of beta-lactam antibiotics relates to isolation of the product. Isolation of the product is problematic for the following reasons:
The antibiotic synthesized in this way is normally obtained as a heterogeneous mixture of solid and dissolved product, which must be separated from the biocatalyst, or in other words, the immobilized enzyme, which is also solid. In this regard, Clausen et al. (PCT WO 96/02663 A1) have published a process for synthesis of beta-lactam antibiotics at constantly high concentration of the reactants, wherein the desired product is obtained mainly as a solid product in the form of small crystals, which are continuously separated from the reactor by passing them through a sieve, which holds up the biocatalyst, into a centrifuge, in which such crystals are isolated. The centrifuge supernatant is pumped back into the reactor via a tank, in which further substrate is added. This process offers a noteworthy advance, in that the product is removed rapidly from the reaction medium via crystallization and centrifugation, and consequently cannot be hydrolyzed to undesired secondary products.
Despite this advantage, the process does not permit problem-free continuous operation in the stirred reactor.
The risk exists that in this process, which in principle is a wet-sieve process, the bottom sieve of the reactor will gradually become fouled because of the non-uniformity of grain sizes, and that the accumulation of solid products will form in the reactor itself a pasty mass at first and ultimately a solid conglomerate of product and catalyst particles, thus making further operation of the reactor impossible.
In summary, it can be said that the prior art known prior to this invention leaves unsolved the true problem, namely the clean separation of the product in combination with reusability, meaning reusability of the biocatalyst. A need, therefore, continues to exist for such a process which can be achieved without problems in the stirred reactor or-in the fixed-bed reactor.
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to provide a process of enzymatic synthesis of β-lactam antibiotics which achieves the clean separation of enzyme biocatalyst from the product and the reusability of the biocatalyst, especially in a stirred reactor or a fixed-bed reactor.
Briefly, this object and other objects of the present invention as hereinafter will become more readily apparent can be attained in a process of synthesizing an amino-group-containing beta-lactam antibiotic, comprising: reacting an amino-beta-lactam component and the corresponding amino-group-containing acylating side-chain component in the presence of a biocatalyst of the immobilized enzyme penicillin amidase from E. coli covalently immobilized on support particles, thereby forming a β-lactam antibiotic product; adding an acid to the obtained suspension of product and immobilized enzyme to pH 1.0 over the temperature range of 0° C., to +5° C., thereby solubilizing the product; separating the product from the immobilized enzyme; and then regenerating the enzyme biocatalyst in terms of its activity by treatment with a buffer in the neutral pH range at a temperature of about +5° C.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The example of the beta-lactam antibiotic ampicillin has shown that the problem of clean separation of enzymatically synthesized ampicillin and the immobilized enzyme used for the purpose can be solved by adding a strong acid to the suspension of product and immobilized enzyme at a temperature of 0° C. to +2° C. until a pH of 1.0 is reached. At this pH all reaction products dissolve rapidly. The products solubilized in this manner can be easily separated, via the bottom sieve of the reactor in the case of a stirred reactor and by elution in the case of a fixed bed reactor, while the immobilized enzyme remains in the respective reactor. The immobilized enzyme is inactivated almost completely, i.e., to an extent greater than 90%, by the acid treatment.
It has now also been found that the enzyme inactivated in this manner can be reactivated almost completely, i.e., to an extent greater than 90%, by adding a buffer of neutral pH to the inactivated immobilized enzyme (I-E) and keeping the I-E in suspension in this buffer for several hours at a temperature of about +5° C.
This regenerability of the I-E after total loss of its activity is the feature of this invention that is not expected by the person skilled in the art. The regenerability according to the invention of the I-E is fully preserved even after several batches and the associated several acid treatments.
This method functions with the penicillin amidase enzyme from E. coli (E.C. 3.5.1.11.) covalently immobilized on macroporous beads of polymethacrylate components. It is likely that this method will also function with penicillin amidases from other microorganisms such as Bacillus megatherium or Xanthomonas Citrii.
The method should function with any beta-lactam antibiotic (BLA) which has a free amino group in the side chain, for example with amoxicillin, cephalexin, cephadroxil, cefaclor or cefroxadine.
The immobilized enzyme (I-E)
The penicillin amidase enzyme from E. coli (E. C. 3.5. 1.11) covalently bound to Eupergit C® is employed for enzymatic synthesis of the beta-lactam antibiotic ampicillin. Such a biocatalyst is synthesized by the FZB Co. (Berlin), for example, and sold under the name PharmaKAT-PcA. This enzyme was used primarily to prepare the products in the experiments leading to the invention.
The support material
Eupergit C® is a bead-like support material for covalent immobilization of enzymes. It is made and marketed by Röhm GmbH (D-64293 Darmstadt). The particle diameter of Eupergit C® is 50-250 microns. It is a copolymer of methacrylamide, N,N′-methylenebismethacrylamide, glycidyl methacrylate and allyl glycidyl ether. Enzymes can be bound covalently to Eupergit C® by means of covalent bonds formed therebetween, for example, the amino groups of the enzyme and the oxirane groups of the glycidyl components of Eupergit C®. This bonding is stable to acids, and so the acid treatment of the invention does not cause detachment of the enzyme from the immobilizate. Eupergit C® itself has adequate acid stability, meaning that it is dimensionally stable and retains its bed volume even after prolonged action of acid, in other words neither swelling nor shrinkage of the immobilizate is observed during pH changes from pH 7.5 to pH 1.0 and vice versa. This is very important in particular for the application of the invention in the fixed-bed reactor. Any other support material which meets the above criteria would also be suitable instead of Eupergit C® for the process of the invention, an example being particles of porous glass, appropriately derivatized with groups which are acid stable and permit formation of acid-stable covalent bonds to the enzyme molecule.
Loss of activity of I-E in the acid pH range
Penicillin amidase covalently bound to Eupergit C® was synthesized and sold under the trade name Eupergit-PcA years ago by Röhm Pharma, a company that no longer exists. An applications-related pamphlet describing the use of this biocatalyst for synthesis of 6-aminopenicillanic acid mentions the loss of activity of the immobilized enzyme in the acid pH range and recommends precautions to minimize this risk.
As expected, almost complete loss of activity (>95%) was observed when we added cold 12.5-25% sulfuric acid to a cooled aqueous suspension of PharmaKAT-PcA and the product mixture of enzymatic ampicillin synthesis, in order to dissolve the undissolved ampicillin at pH 1.0 so that it could be removed by filtration from the biocatalyst particles. This type of solubilization and separation of the ampicillin from the product mixture proved to be an efficient and easily performed method, but, as expected, at the cost of almost complete loss of activity of the biocatalyst.
The solubilization of amino-group-containing beta-lactam antibiotics from their product mixture by acidification after separation from the biocatalyst (or in other words in the absence thereof!) is disclosed in U.S. Pat. No. 5,470,717.
Regeneration of the activity of the enzyme inactivated by acid
It has been surprisingly found that the biocatalyst inactivated as described above can be successfully regenerated almost completely, meaning that its original enzyme activity is successfully regained, by incubating the biocatalyst in 0.1 molar potassium phosphate buffer at pH 7.5 for a period of 8-30 hours at about +5° C.
Using the same immobilized enzyme sample in all cases, the enzymatic procedure was performed four times in succession, in other words over four consecutive synthesis cycles, without noticeable loss of enzyme activity, enzyme activity being defined as the quantity of synthesized product per unit of synthesis time per unit of enzyme quantity used. After each synthesis step the pH of the product suspension was adjusted to 1.0 at 0° C. with sulfuric acid; the product solution was then filtered off; the I-E remaining on the filter in the reactor was first washed with water and then buffer was added to the I-E obtained. The mixture was incubated for 16 hours at pH 7.5 and about +5° C. Further experimental details and results are provided in the Examples.
The applicability of the process of the invention for enzymatic BLA synthesis in the stirred reactor and in the fixed-bed reactor is demonstrated in the Examples. From the results it can be concluded that the operational stability (O-ST) of the I-E is more than four synthesis cycles provided the procedure of the present invention is followed.
Regenerability of I-E after inactivation by acid: an INNOVATION compared with the prior art
The ability of the immobilized enzyme (I-E) to regenerate after its almost complete inactivation by acid could not have been suggested by the prior art. It has been known that, after inactivation at pH 2.0, the free enzyme can be regenerated to about 40% of its original activity by incubation in neutral buffer, whereas the reactivability of the enzyme immobilized on Eupergit C® instead “diminished” (U. Haufler, Dissertation, page 103, Bremen University, 1987 as well as Haufler et al., DECHEMA Biotechnol. Conf(1988), Volume Date 1987, 1., 345-350). However, such a reduction in regenerability was not confirmed in the studies of the invention. To the contrary, even after four consecutive inactivations under acid stress, or in other words at a hydronium ion concentration which was ten times higher than in the experiments of U. Haufler and which, moreover, was repeated four times, the I-E treated in the manner of the invention was reactivated to almost 100% (>95%) of its original activity and O-ST relative to enzymatic ampicillin synthesis.
Reactors for performing the process of the invention
As already mentioned, the process of the invention can be performed in any type of reactor which is suitable for the use of immobilized enzymes for biocatalytic purposes.
If a stirred-tank reactor is employed, it must be equipped with a bottom sieve or with filter candles in order to hold up the biocatalyst, or in other words the I-E, in the reactor, specifically during all individual steps of the procedure, i. e., during enzymatic synthesis as well as during solubilization of the product by acid addition, during separation of the product by filtration, during regeneration of the immobilized enzyme by incubation in buffer, and during recharging of the reactor with substrate solution for the next cycle.
All of these steps can be performed conveniently in the same reactor, in a one-pot process as it were.
Suitable as fixed-bed reactors (FBR) are columns for preparative chromatography (on the production scale), as sold by several companies (for example, Merck/Darmstadt), provided they are made of acid-stable materials and are equipped with acid-stable supply and discharge tubes whose inside diameter is large enough to permit relatively high flowrates. The columns must also be equipped with a temperature-control jacket through which cooling fluid can be passed. In addition, the standard systems must be supplemented with devices which permit acid or buffer to be recirculated through the column and to be cooled efficiently by additional external cooling systems. Furthermore, suitable pumps, as well as measuring instruments for pressure, temperature and flowrate, are needed for operation and control of the FBR. Systems which permit automatic control are desirable.
An FBR is operated as follows:
The substrate solution is pumped continuously at constant flowrate through the FBR column (containing I-E) and the product formed therein is collected at the outlet of the column in a tank for further purification. As soon as the flowrate decreases or the pressure in the column rises, which is an indication that the column is becoming gradually fouled by product crystals, the substrate feed is stopped and a supply of acid which has been cooled to 0° C. by passage through a cooling batch is started. This acid stream is recirculated continuously through the column, which is also being cooled by means of its temperature-control jacket, until all solid product has dissolved in the acid, which is recognized by the fact, for example, that the same flowrate as at the start of substrate addition has been reached. At this point in time the acid recirculation is stopped, and the acid is collected in a separate tank while cold washing water is supplied at the same time.
The washing water is recirculated through the column for about 20 minutes, Then the recirculation of water is stopped. The water is collected in a tank, while at the same time the supply of cold regeneration buffer is started. This buffer is recirculated through the column for 12-16 hours at +5° C. Then the buffer recirculation is stopped. The buffer is collected in a tank, while at the same time the supply of substrate solution is started, after the column temperature has been adjusted to +25° C.
The result of four consecutive sequences of operation of such a column on the laboratory scale is presented in Examples 7-10. The results show that an FBR permits better control of the reaction with regard to synthesis than is possible in the stirred tank. However, an FBR involves considerably greater engineering complexity and the greater risks of faulty control that are inevitably associated therewith.
Summation
The results of the experiments in the FBR and in the stirred tank show the technical applicability of the inventive principle of product isolation in the presence of the biocatalyst at pH 1.0 and the regeneration of the biocatalyst by incubation in neutral buffer. In the present scope of application, namely the enzymatic synthesis of beta-lactam antibiotics, it was not practical to examine whether this principle also functions in the alkaline pH range.
Abbreviations used in the text:
I-E:
immobilized
FBR:
fixed-bed reactor
enzyme
O-ST:
operational stability
SLR:
stirred tank reactor
of the activity
HPLC:
high performance
of an I-E
liquid
DEI-water:
deionized water
chromatography
g:
gram
NMR:
nuclear magnetic
ml:
milliliter
resonance
6-APA:
6-aminopenicillanic
pH:
negative logarithm
acid
(to the base 10) of
7-ADCA:
7-aminodesacetoxy-
the molar
cephalosporanic
hydrogen ion
acid
concentration
PcA:
penicillin amidase
PHE-GLY:
D-phenylglycine
E. coli :
Escherichia Coli
PHE-GLY-ME:
D-phenylglycine
methyl ester
Having now generally described the invention, a further understanding can be obtained by reference to certain specific Examples which are provided herein for purpose of illustration only and are not intended to be limiting unless otherwise specified.
EXAMPLES
Example 1
Preparation of the Substrate Solution for Experiments in the Stirred Tank Reactor (SLR)
To 20 ml of deionized water there were added 4.3 g of 6-aminopenicillanic acid (6-APA) and 10 g of phenylglycine methyl ester hydrochloride. Approximately 38 ml of ammonia (1.25 molar aqueous solution) was added dropwise with stirring and cooling to 18-22° C., such that the pH of the mixture did not exceed a value of pH 8.0 at the start and a pH of 7.0 at the end of the dissolution process. In this way, about 65 ml of substrate solution was obtained. The solution was weighed and, after removal of a small quantity (about 1 g) for analytical purposes, was used quantitatively for one enzymatic synthesis in the stirred reactor.
Example 2
Enzymatic Synthesis in the Stirred Tank Reactor STR/First Batch
The substrate solution of Example 1 was added with stirring to 20 grams (moist weight) of penicillin amidase immobilized on Eupergit C®. PharmaKAT-PcA, a commercial product of FZB Biotechnik GmbH of Berlin, was used for this purpose.
The suspension was stirred for 180 minutes at 23-25° C., while the pH was maintained constant at pH 7.0 by addition of small quantities of 1.25 molar ammonia.
The mixture was then cooled to 0° C. and thereafter 2.5 molar (approximately 25%) sulfuric acid was added dropwise with stirring, constant cooling to 0° C. and precise pH control until a constant pH of 1.0 was achieved. Then this solution was stirred for a further 10-20 minutes with cooling to 0° C. and thereafter was removed by suction through the bottom sieve of the reactor. A 1.0 g amount of the filtrate was diverted for analytical determinations. The main quantity was used for isolation of the reaction products. For this purpose the pH was adjusted to pH 5.1 by addition of concentrated ammonia, while the temperature of the mixture was kept consistently at 0° C. by cooling. The mixture was stirred for 2 hours at 0° C. and pH 5.1. Meanwhile a crystalline product was precipitated. It was removed by filtration and washed with cold water, rapidly suctioned and dried overnight in vacuum at +30° C. A 7.67 g amount was obtained. This product was subjected to HPLC to determine its content of ampicillin trihydrate; result: 51% ampicillin trihydrate, corresponding to 3.9 g (9.67 mmol), which corresponds to a yield of 48% relative to the feed quantity of 6-APA.
The immobilized enzyme remaining on the filter in the STR was suspended in 100 ml of cold DEI-water and adjusted to a pH of 6.5-7.0 with cold 1.25 molar ammonia with stirring and cooling, further stirred for 10 minutes and suctioned. Then 100 ml of cold K phosphate buffer (0.1 molar, pH 7.5) was added. The mixture was stirred gently for 3 hours at +5° C. and then left in the reactor without further stirring for 12 hours at +5° C.
Example 3
Enzyme Synthesis in the STR/Second Batch
The phosphate buffer from Example 2 was removed by suction from the I-E, thus leaving the I-E on the bottom strainer in the reactor. There it was washed with 50 ml of 23° C. water and suctioned. Then substrate was added to the I-E as in Example 1.
The suspension of I-E in the substrate solution was stirred for 180 minutes at 23-24° C. In this step and in the subsequent further process, exactly the same procedure as described for Example 2 was followed.
Result: 7.46 g of crystalline product.
Content of ampicillin trihydrate: 3.4 g, corresponding to 42% yield relative to 6-APA.
Example 4
Enzyme Synthesis in the STR/Third Batch
The phosphate buffer from Example 3 was removed by suction from the I-E, and then exactly the same procedure as described for Example 2 was followed.
Result: 7.3 g of crystalline product.
Content of ampicillin trihydrate: 4.0 g, corresponding to 50% yield relative to 6-APA.
Example 5
Enzyme Synthesis in the STR/Fourth Batch
The phosphate buffer from Example 4 was removed by suction from the I-E, and then exactly the same procedure as described for Example 2 was followed.
Result: 7.32 g of crystalline product.
Content of ampicillin trihydrate: 3.2 g, corresponding to 40% yield relative to 6-APA.
As a relative measure for the ratio of synthesis to hydrolysis, the ratio of areas of ampicillin trihydrate to D-phenylglycine in the HPLC diagram was 1.1.
Example 6
Preparation of the Substrate Solution for Experiments in the Fixed-Bed Reactor (FBR)
A 16.1 g amount of 6-APA and 15.0 g of D-phenylglycine methyl ester hydrochloride were dissolved in 190 ml of DEI-water with stirring at 24-25° C. by careful addition of ammonia (2.4 molar) and adjusted to a pH of 7.0. About 45 ml of ammonia in total was added for this purpose.
Example 7
Enzymatic Synthesis in the Fixed-Bed Reactor (FBR)/First Use
An FBR was filled to a bed volume of 110 ml with an aqueous suspension of Penicillin amidase immobilized on Eupergit C® (PharmaKAT-PcA) in DEI-water. The reactor was made of stainless steel. Its diameter was 43 millimeter (mm) and its height was 150 mm. The filled height of the fixed bed was 76 mm.
Substrate solution (according to Example 6) was introduced from above onto this fixed bed, passed through the fixed bed at a flowrate of 2.5 ml per minute and collected in fractions. The contents of ampicillin, 6-APA, D-phenylglycine methyl ester and D-phenylglycine in individual fractions were determined with HPLC. (See the table for individual results.) As a relative measure of synthesis/hydrolysis, the ratio of areas of ampicillin to D-phenylglycine in the HPLC diagram was 0.83.
After 150 ml of reacted substrate solution had been collected, the supply of substrate solution was stopped and 1.25 molar sulfuric acid was passed through the fixed bed at a temperature of 0° C. until a pH of 1.0 was reached at the outlet of the fixed-bed reactor. As soon as the pH measurement at the fixed-bed outlet showed a pH of 1.0 for a period of 30 minutes, the supply of sulfuric acid was stopped. Following a washing step with cold water, the supply of potassium phosphate buffer (0.1 molar, pH 7-5) at a temperature of +5° C. was started. As soon as a pH of 7.5 was reached at the outlet of the reactor, the buffer stream through the column was switched to recirculation, or in other words to flow in a closed loop, which was maintained for 12 hours at a flowrate of 1 ml/min and a temperature of +5° C.
In this manner the biocatalyst was regenerated for the next use for synthesis of ampicillin.
Example 8
Enzymatic Synthesis in the Fixed-Bed-Reactor (FBR)/Second Use
The immobilized enzyme regenerated by incubation with buffer from Example 7 was washed with DEI-water in the FBR. Substrate solution (according to Example 6) was introduced from above onto this fixed bed, passed through the fixed bed at a flowrate of 1.7 ml per minute and collected in fractions at the reactor outlet. The contents of ampicillin, 6-APA, D-phenylglycine methyl ester and D-phenylglycine in individual fractions were determined with HPLC.
Individual results: see table.
Relative measure of synthesis to hydrolysis (corresponding to ratio of areas in the HPLC diagram) was 1.9.
After 150 ml of reacted substrate solution had been collected, the supply of substrate solution was stopped. The further procedure was identical to that of Example 7.
Example 9
Enzymatic Synthesis in the Fixed-Bed Reactor (FBR)/Third Use
The regenerated immobilized enzyme from Example 8 was used, and otherwise the same procedure as described for Example 8 was followed, with the difference that the flowrate was 1 ml per minute and the substrate supply was stopped after collection of 170 ml.
Individual results: see table.
Relative measure of synthesis to hydrolysis (corresponding to ratio of areas in the HPLC diagram) was 2.2.
Example 10
Enzymatic Synthesis in the Fixed-Bed Reactor (FBR)/Fourth Use
The regenerated immobilized enzyme from Example 9 was used, and otherwise the same procedure as described for Example 9 was followed, with the difference that the substrate supply was stopped after collection of 304 ml.
Individual results: see table.
Relative measure of synthesis to hydrolysis (corresponding to ratio of areas in the HPLC diagram): 2.1.
Example 11
Performance of the HPLC Studies: Method and Material
A Hewlett-Packard HP 1100 instrument was used for the HPLC studies.
Sample preparation
A 1 g amount of solution (in the stirred-reactor experiments after solubilization by H 2 SO 4 ; in the FBR experiments directly from the Column eluate) was diluted with phosphate buffer (25 millimolar; pH 6.5) to a final volume of 25 ml.
For testing of solid samples, 50 mg of product was dissolved in 50 ml of phosphate buffer (25 millimolar, pH 6.5).
Formulation of the standard solutions
A 50 mg amount of ampicillin trihydrate or 50 mg of D-phenylglycine or 50 mg of 6-APA or 50 mg of D-phenylglycine methyl ester hydrochloride respectively was dissolved in each case in 50 ml of phosphate buffer (25 millimolar, pH 6.5).
Method: gradient method
Eluent A: 25 millimolar phosphate buffer (pH 6.5)
Eluent B: acetonitrile
Flowrate: 1 ml/min
Wavelength: 215 nm
Injection volume. 20 microliter
Analysis duration: 20 minutes
HPLC column: MAXIL 5C18 (250×4.60 mm), 5 micron
Table of results of enzymatic ampicillin synthesis in the FBR (corresponding to Examples 7 to 10)
Guide value
Components in
First use
Second use
Third use
Fourth use
for elution
the product
Flowrate 2.5 ml/min
Flowrate 1.7 ml/min
Flowrate 1.0 ml/min
Flowrate 1.0 ml/min
volume *
mixture
HPLC area/elution vol.
HPLC area/elution vol.
HPLC area/elution vol.
HPLC area/elution vol.
100 ml
PHE-GLY
10242
9399
8094
(n.t.)
6-APA
49892
44959
39514
AMPICILLIN
9725
100 ml
16293
120 ml
10187
100 ml
PHE-GLY-ME
56103
26339
(n.t.)
150 ml
PHE-GLY
12468
11266
17606
17501
6-APA
50789
42381
40866
24240
AMPICILLIN
10308
150 ml
21602
150 ml
37134
150 ml
34237
160 ml
PRE-GLY-ME
66289
54714
36732
2193**
200 ml
PHE-GLY
not tested
(n.t.)
(n.t.)
18407
6-APA
(n.t.)
23848
AMPICILLIN
37184
200 ml
PHE-GLY-ME
10947**
250 ml
PHE-GLY
(n.t.)
(n.t.)
(n.t.)
18901
6-APA
24491
AMPICILLIN
39567
260 ml
PHE-GLY-ME
15016
300 ml
PHE-GLY
(n.t.)
(n.t.)
(n.t.)
17882
6-APA
23806
AMPICILLIN
37308
300 ml
PHE-GLY-ME
17246
Abbreviations:
PHE-GLY → D-phenylglycine
6-APA → 6-aminopenicillanic acid
AMPICILLIN → ampicillin trihydrate
PHE-GLY-ME → D-phenylglycine methyl ester
*The exact value of the elution volume is listed in the respective column
**Retardation of the ester for an unknown reason
The disclosure of German priority Application No. 198 23 332.9-42 filed May 26, 1998 is hereby incorporated by reference into the present application.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | Beta-lactam antibiotics are synthesized by reacting an amino-beta-lactam component with a corresponding amino-group-containing acylating side-chain component in the presence of penicillin amidase from E. coli covalently immobilized on support particles. The resulting beta-lactam antibiotic product is solubilized by adding an acid such as sulfuric acid to lower the pH to 1.0 at a temperature in the range of 0° C. to +5° C. The immobilized penicillin amidase is substantially inactivated by the acid. After separating the beta-lactam antibiotic product, the immobilized penicillin amidase is substantially reactivated for reuse in antibiotic synthesis by treatment with a buffer having about a neutral pH. Antibiotics that can be produced include ampicillin, amoxicillin, cephalexin, cefaclor and cefadroxil. Support particles that can be used include particles having a macroporous structure and a particle diameter of 10-1000 μm, particles having oxirane groups, particles made of a synthetic polymer and inorganic particles such as porous glass particles. | 2 |
BACKGROUND
[0001] The present invention relates generally to integrated circuit memory devices and, more particularly, to a method and apparatus for automatically adjusting the pull-up margin of a match line circuit used in conjunction with a content addressable memory (CAM).
[0002] A content addressable memory (CAM) is a storage device in which storage locations are identified by their contents, not by names or positions. A search argument is presented to the CAM and the location that matches the argument asserts a corresponding match line. One use for such a memory is in dynamically translating logical addresses to physical addresses in a virtual memory system. In this case, the logical address is the search argument and the physical address is produced as a result of the dynamic match line selecting the physical address from a storage location in a random access memory (RAM). CAMs are also frequently used for Internet address searching.
[0003] A conventional CAM array 1 having n-bit words is shown in FIG. 1 to include a row of n CAM cells 10 coupled to an associated word line WL. Each CAM cell 10 includes a latch, formed by CMOS inverters 12 and 14 , for storing a bit of data. Opposite sides of the latch are coupled to associated complementary bit lines BL and BL bar via pass transistors 16 and 18 , respectively, where each transistor has a gate coupled to the associated word line WL. The output terminal of the inverter I 2 is coupled to the gate of an NMOS pass transistor 20 , and the output terminal of the inverter I 4 is coupled to the gate of an NMOS transistor 22 . Transistor 20 is coupled between the associated bit line BL and the gate of an NMOS pull-down transistor 24 , and transistor 22 is coupled between the associated complementary bit line BL bar and the gate of pull-down transistor 24 . Pull-down transistor 24 is coupled between ground potential and a match line ML associated with the CAM word formed by the cells 10 . A PMOS pull-up transistor 26 is coupled between a supply voltage V DD and the match line ML.
[0004] In the configuration of FIG. 1, the pull-up transistor 26 has a gate tied to ground potential and, therefore, remains in a conductive state. A conventional buffer 28 is coupled in series between the match line and an associated sensing circuit (not shown). During compare operations, the word line WL associated with the CAM word is grounded to turn off the pass transistors 16 and 18 associated with each CAM cell 10 . Comparand bits to be compared with the data bits Q stored in the CAM cells 10 are provided to the associated bit lines BL, while the respective complements of the comparand bits are provided to the associated complementary bit lines BL bar. For each CAM cell 10 , if the comparand bit matches the data bit Q stored therein, the gate of the corresponding pull-down transistor 24 is driven with a logic low signal via transistors 20 or 22 , thereby maintaining the pull-down transistor 24 in a non-conductive state. If, on the other hand, the comparand bit does not match the data bit Q stored in the CAM cell 10 , the gate of the corresponding pull-down transistor 24 is driven with a logic high signal via transistors 20 or 22 , thereby turning on the pull-down transistor 24 . When conductive, the pull-down transistors 24 pull the match line toward ground potential.
[0005] Thus, if just one of the comparand bits do not match their corresponding data bits Q stored in the CAM cells 10 , the match line ML will be pulled to a logic low state (i.e., ground potential). Conversely, if all of the comparand bits match their corresponding data bits Q, the match line ML remains at the supply voltage V DD (i.e., a logic high state). In response to the voltage level on the match line ML, the buffer 28 provides to an associated sense circuit (not shown) an output signal indicative of whether all bits of the comparand word match all corresponding bits of the CAM word.
[0006] One disadvantage of the above described CAM configuration results from the fact that during a standby mode, DC current will flow through the match line circuit unless the bitline nodes (BL, BL bar) are precharged low. Otherwise, the path to ground potential results in significant power dissipation which, in turn, undesirably increases as the size and/or density of the CAM increases. On the other hand, the use of additional circuitry to precharge the bitline pairs also have negative impacts on device size and cost.
BRIEF SUMMARY
[0007] The above discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by a method for determining a desired operating impedance for a computer memory circuit, the computer memory circuit having a plurality of discrete, selectively adjustable impedance values associated therewith. In an exemplary embodiment of the invention, the method includes applying, to a reference circuit, a test impedance value to a reference circuit. The test impedance value is controlled by a binary count. A determination is made, based upon the applied test impedance value, whether the reference circuit is in either a first state or a second state. The binary count is incremented if the reference circuit is in the first state and decremented if the reference circuit is in the second state. A condition is determined in which the reference circuit oscillates between the first state and said second state, and a pair of binary count values is stored. One of the binary count values represents a first impedance value which causes the reference circuit to change from the first state to the second state, and the other binary count value represents a second impedance value which causes the reference circuit to change from the first state to the second state. The desired operating impedance for the computer memory circuit corresponds to the lower of the stored pair of binary count values.
[0008] In a preferred embodiment, the lower of the stored pair of binary count values is adjusted by subtracting a predetermined, fixed value therefrom so as to create a buffered count. The buffered count is then used in applying the desired operating impedance to the operating circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Referring to the exemplary drawings wherein like elements are numbered alike in the several Figures:
[0010] [0010]FIG. 1 is a schematic diagram of a CAM cell array configured to an existing match line circuit having a single pull-up device;
[0011] [0011]FIG. 2 is a schematic diagram of a low-power match line circuit which may be implemented as an alternative to the circuit of FIG. 1;
[0012] [0012]FIG. 3 is a schematic diagram of a low-power match line circuit having a self-adjusting pull-up margin, in accordance with an embodiment of the invention;
[0013] [0013]FIG. 4 is a truth table which illustrates the relative pull-up strength combinations of the pull-up devices shown in FIG. 3;
[0014] [0014]FIG. 5 is a schematic diagram of a reference circuit used in conjunction with the circuit shown in FIG. 3, in accordance with an embodiment of the invention;
[0015] [0015]FIG. 6 is a block diagram illustrating functional relationship between the reference circuit of FIG. 5 and the circuit of FIG. 3, as well as the generation of a buffered count to be inputted to the circuit of FIG. 3; and
[0016] [0016]FIG. 7 is a timing diagram illustrating the interrelationship between external clock signals and signals generated by the reference circuit of FIG. 5.
DETAILED DESCRIPTION
[0017] Referring initially to FIG. 2, there is shown a schematic diagram of one possible embodiment of a low-power, match line circuit 200 for a CAM sense amplifier. Match line circuit 200 replaces pull-up PFET 26 and buffer 28 of FIG. 1. For ease of description, only one CAM cell is depicted in FIG. 2. Match line circuit 200 includes pull-up PFET T 4 coupled to a voltage supply V DD and a pull-down NFET T 6 connected to ground. The gates of both T 4 and T 6 are coupled to an ENABLE signal which is initially biased at logic high (e.g., at V DD potential) and which goes to logic low (e.g., at ground potential) during a search or compare operation. In addition, the drains of T 4 and T 6 are coupled to match line ML and thereby define a node labeled MATCH in FIG. 2.
[0018] The ENABLE signal is also coupled to an inverter I 1 which, in turn, has an output thereof connected to the gate of pull-up PFET T 5 . Another pull-down NFET T 8 has its drain connected to the drain of T 5 , thereby defining a node labeled FLOAT, which is described in further detail hereinafter. The gate of T 8 is further connected to the MATCH node. Finally, a second inverter I 2 has an input connected to the FLOAT node and an output which defines a node labeled HIT.
[0019] The operation of the match line circuit 200 is understood with reference to the following description. In between search (compare) operations, ENABLE is biased at logic high, as stated earlier. Thus, NFET T 6 is rendered conductive, pulling MATCH to ground. As a result, SL and SL bar may remain in their previous state, thereby eliminating the power required to precharge them. Further, the conductive state of T 6 prevents any DC current flowing during a standby mode. This is in contrast to the circuitry shown in FIG. 1, wherein the match line is biased to V DD prior to a data comparison operation, and BLIBL bar must be switched to ground in order to eliminate a DC path.
[0020] It will also be noted that, prior to a search operation, the output of 11 is low, thereby rendering PFET T 5 conductive and charging FLOAT to V DD (since T 8 is switched off by the bias on MATCH). The output of inverter I 2 , therefore is low, and there is no “hit signal” on HIT.
[0021] During a search, ENABLE is switched to low and a comparand data bit (with associated complement) is applied to the array cell through search lines SL and SL bar. Once ENABLE goes low, T 6 is turned off and T 4 is rendered conductive, attempting to pull MATCH up toward logic high. In the meantime, the output of inverter I 1 switches from low to high, thereby turning off T 5 and causing the FLOAT node to “float” at a high voltage (until such time as T 8 might become conductive). So long as FLOAT remains charged high, the output at HIT will remain low, signifying a data match has not yet occurred.
[0022] In the event that a data match occurs (i.e., each bit in the stored CAM word matches each corresponding bit in the comparand word), none of the pull-down NFETs associated with each cell will be activated and thus will not prevent T 4 from pulling MATCH up toward high. During this time, the voltage at MATCH will rise asymptotically to a voltage level determined by the relative strengths of T 4 and the pull-down NFETs in the cells. Once the voltage level at MATCH reaches the threshold value of T 8 , T 8 will turn on and discharge FLOAT to ground. In turn, HIT will then be switched from low to high by inverter I 2 , thereby signaling a data match.
[0023] However, if one or more of the comparand data bits do not match the corresponding stored data bits, there will be at least one pull-down NFET opposing the pull-up of T 4 . Accordingly, the voltage value at MATCH will be kept below the threshold value of T 8 so as not to discharge FLOAT and falsely indicate a hit (data match) condition. In the case of a “marginal miss” scenario where there is only one mismatched bit (and thus only one pull-down path activated), the conductivity of T 4 could be just strong enough so as to overcome the pull-down of the lone mismatched cell and pull MATCH all the way up to the threshold of T 8 , thereby triggering a false match. Such a condition is not out of the realm of possibility, given the real world of process variations, inaccurate device models and unpredictable operating conditions. Thus, T 4 is designed to be a weak pull-up PFET.
[0024] On the other hand, the weaker the pull-up device used, the longer the time it takes for the device to perform its intended function. Since speed is an important consideration in the design of integrated circuit devices, it is therefore desirable to have a match line circuit for a CAM sense amplifier featuring a pull-up device strong enough to avoid a speed penalty while not allowing the asymptotic match line voltage to reach the threshold voltage (V t ) of the pull-down transistor T 8 during a “marginal miss”. Unfortunately, this can be a difficult proposition by using a single transistor (T 4 ) as the pull-up device.
[0025] Therefore, in accordance with an embodiment of the invention, a self-adjusting margin circuit for a CAM sense amplifier is disclosed, which provides automatic control of the margin between the asymptotic MATCH node voltage and the NFET V 1 . A preferred approach is to employ a PFET device having a controllable, adjustable pull-up strength responsive to actual operating conditions.
[0026] Referring now to FIG. 3, there is shown an improved match line circuit 300 for use in a CAM array. For ease of description, like or equivalent circuit components in circuit 300 are given the same reference designations as in FIG. 2. In circuit 300 , pull-up PFET T 4 (FIG. 2) has been replaced by PFET TO, as well as a parallel group of PFETs T 20 , T 21 , T 22 and T 23 connected thereto. TO acts as a switch which enables T 20 -T 23 , in combination, to determine the specific impedance (and thus the strength) of the pull up path. PFET T 20 remains conductive since the gate thereof is connected to ground, thereby defining a “default” or minimum strength pull-up value for circuit 300 . The remaining PFETs T 21 , T 22 and T 23 are selectively activated by DC control signals SAM 4 , SAM 2 and SAM 1 , respectively, which control signals determine a discrete value for the pull-up path impedance.
[0027] Control signals SAM 4 , SAM 2 and SAM 1 , collectively, may be thought of as a three-bit binary word whose value is proportional to the overall pull-up strength of circuit 300 . The PFET device characteristics are chosen such that SAMI is the least significantly weighted bit and SAM 4 is the most significantly weighted bit. FIG. 4 is a truth table illustrating the resulting device pull-up strength versus the specific combination of activated PFETs. As can be seen, the pull-up strength is minimum with only default PFET T 20 being conductive and maximum when all four PFETs are conducting.
[0028] It should be understood that the “ 1 ” and “ 0 ” representations shown in the truth table of FIG. 4 represent the conductive state of the PFETs and not the logic level of the voltage applied to the gates thereof. In other words, first entry in the table (1, 0, 0, 0) signifies that T 21 , T 22 and T 23 are each switched off, not that the inputs on control signals SAM 4 , SAM 2 and SAM 1 are all “low” or “logic 0”. On the contrary, because these devices are PFETs, the voltage inputs on control signals SAM 4 , SAM 2 and SAM 1 would actually be high (e.g., V DD ) to render them non-conductive.
[0029] Although in the presently disclosed embodiment a three-bit word is used to provide eight discrete pull-up impedance values, it will be understood that additional binary-weighted transistors may be used to provide a finer range of incremental values.
[0030] Given the range of adjustable pull-up impedances provided by circuit 300 , the next task then becomes one of dynamically controlling the PFETs (T 21 , T 22 and T 23 ) such that a specific desired pull-up impedance is achieved in view of possible variations in process conditions and operating conditions. Again, it is desired to use the highest pull-up strength which is also within an acceptable range so as not to create false hit indications.
[0031] Accordingly, FIG. 5 illustrates a reference circuit 500 which features devices substantially similar to those included within circuit 300 , and which are preferably formed upon the same chip as circuit 300 and the CAM array. However, in contrast to a plurality of circuits 300 associated with the CAM array cells, there need only be a single reference circuit 500 . In effect, reference circuit 500 is used as a “dummy” or test circuit which is self-adjusting so as to determine a desired impedance strength for the pull-up devices included in the actual operating match line circuits 300 .
[0032] As with circuit 300 , reference circuit 500 includes a plurality of parallel connected PFET pull-up transistors labeled T 30 , T 31 , T 32 and T 33 , which are analogous to T 20 , T 21 , T 22 and T 23 . T 30 , having its gate connected to ground, provides a minimum pull-up strength value for reference circuit 500 . Similar to circuit 300 , the selectively adjustable PFETs T 32 , T 32 and T 33 are controlled by input signals P 4 , P 2 and P 1 which comprise a three bit binary word. The values of P 4 , P 2 and PI are driven from latches in a counter, described in greater detail hereinafter.
[0033] Because reference circuit 500 is not physically connected to a CAM array, but is instead used in conjunction with a “simulated” CAM array, a dummy capacitive load C 0 is connected thereto. The capacitive load C 0 is intended to make the MATCH node capacitance look like a “real” match node having several capacitive loads coupled therewith. In addition, NFETs T 27 and T 28 provide a constant pull-down path which will continuously simulate a “marginal miss” condition where there is only a single CAM cell providing a pull-down path.
[0034] In operation, reference circuit 500 performs essentially the same function as the circuits 300 used in the CAM arrays. Instead of being activated by the ENABLE signal, reference circuit 500 is triggered by the rising edge of a clock signal CLKEVAL (described in additional detail later). Recalling that the operation of circuit 300 is triggered by ENABLE going from high to low, an inverter I 3 is connected to CLKEVAL in reference circuit 500 . Thus, when CLKEVAL rises the PFET network will be enabled, attempting to pull the MATCH node up to its asymptotic voltage.
[0035] If the initial value of the PFET pull-up strength (provided by T 30 , T 31 , T 32 and T 33 ) is not too strong, FLOAT will not be discharged and, if too strong, FLOAT will be discharged. Since the primary purpose of reference circuit 500 is to determine the counter value (P 4 , P 2 , P 1 ) which provides the strongest pull-up value that will not discharge FLOAT, the next highest pull-up value that does discharge FLOAT should also be determined. Accordingly, the HIT node of reference circuit 500 is further coupled to a latch L 1 which latches the result of an evaluation upon the triggering of clock signal CLKXFER. The output of latch L 1 is a signal labeled DOWN, which signal thus controls the direction of the counter.
[0036] By way of example, it will be assumed that the maximum pull-up strength of reference circuit 500 (which does not result in FLOAT being discharged) corresponds to the binary word value <101> applied to inputs P 4 , P 2 and P 1 . Reference circuit 500 will determine this value by having the input values of P 4 , P 2 and P 1 automatically adjusted until the oscillation point is found, regardless of the initial setting of P 4 , P 2 and P 1 . Thus, if upon the initial evaluation, the PFET strength is too strong, this will be reflected by the latch DOWN signal, and the binary value applied to P 4 , P 2 and P 1 is decremented by one bit for this evaluation. This will continue until FLOAT is not discharged, and then the binary value will be incremented by one bit for the next evaluation.
[0037] Continuing with the above example, the following is a table which illustrate one possible sequence of reference circuit evaluations (iterations) performed. Again, it will be assumed in this example that the maximum pull-up strength resides at input value <101> and that the initial value on the counter applied to P 4 , P 2 and P 1 is <000>:
Counter Value FLOAT DOWN signal result 000 charged increment by one 001 charged increment by one 010 charged increment by one 011 charged increment by one 100 charged increment by one 101 charged increment by one 110 discharged decrement by one 101 charged increment by one 110 discharged decrement by one
[0038] It will be seen in the above example that the reference circuit 500 has reached an equilibrium state where the float node is oscillating between charged and discharged where PFET pull-up strengths correspond to the 101 and the 110 values. Therefore, circuit 500 determined that the maximum PFET pull-up strength corresponds to the impedance value when T 31 and T 33 are conductive and T 32 is off (T 30 always being on). Reference circuit 500 will determine this point regardless of whether the initial value applied to P 4 , P 2 and P 1 is “too high” or “too low”.
[0039] Equally as important is the fact that reference circuit 500 also allows for dynamic changes in maximum allowable PFET pull-up strength during circuit operation. For example, it may be that circuit temperature conditions result in the lowering of maximum allowable PFET pull-up strength. Thus, a continuation of the above table could look as follows:
Counter Value FLOAT DOWN signal result 110 discharged decrement by one 101 charged increment by one 110 discharged decrement by one 101 charged increment by one 110 discharged decrement by one 101 discharged decrement by one 100 charged increment by one 101 discharged decrement by one 100 charged increment by one
[0040] As can be seen, the oscillation point has now been lowered such that new maximum allowable PFET pull-up strength corresponds to a <100> input at P 4 , P 2 and P 1 .
[0041] Finally, FIG. 6 is a block diagram illustrating the generation of the counter value applied to reference circuit 500 , as well as the interaction between the reference circuit 500 and the match line circuits 300 used in the CAM arrays. A clock generator 502 generates the clock signals CLKEVAL and CLKXFER (described above) sent to reference circuit 500 . The rising edge of CLKEVAL begins an evaluation, while the falling edge of CLKEVAL latches the value of HIT and creates the DOWN signal. The interrelationship between the clock signals and the HIT and DOWN signals is illustrated in FIG. 7.
[0042] In a preferred embodiment, the clock generator 502 also comprises a clock divider therein such that the evaluation is performed every 64 th system clock cycle. In one aspect, it is assumed that any drifting in operating conditions is relatively slow as compared to the system clock rate. Additionally, a divide-by-64 clock generator helps to conserve power dissipated in the circuit. However, it should be understood that other clock divider ratios (e.g., divide-by-32) may also be implemented.
[0043] Referring once again to FIG. 6, it is seen that the DOWN signal generated within reference circuit 500 is sent to an up/down counter 504 which counts up or down by one bit, depending upon the directional value of DOWN. Upon receiving the clock signal CLKEVAL, up/down counter 504 generates the next three-bit count. This new count is then applied back to P 4 , P 2 and P 1 so that, in turn, an increased/decreased PFET pull-up strength is applied for the next evaluation.
[0044] At the same time, a first register 506 stores the new count, as well as the count from the previous evaluation. Then, a comparator 508 selects the lower value of the new count and the previous count to correctly identify which of the two stored counts represents the correct PFET pull-up value that does not cause a false hit indication. In effect, comparator 508 and first register 506 act as a filter, producing a stable count since the equilibrium count is oscillating by one (least significant) bit. Because the count identified by comparator 508 represents the maximum PFET pull-up strength allowed for correct CAM circuit operation, an adder 510 is used as a buffer margin. Adder 510 will then subtract a predetermined amount from the “optimal” count, thereby producing a “conditioned” or buffered count. This conditioned count is then stored in a second register 512 and is used to control the actual pull-up PFETs used in the match line circuitry.
[0045] The fixed value that the adder 510 subtracts from the count (determined by comparator 508 ) may be chosen based on experience with the system hardware and can be coded within fuses. Assuming, for example, that this fixed value is designed to be a subtraction by 1 bit, than an oscillating count (as in the above example) between <101> and <110> results in comparator 508 identifying <101> as the maximum pull-up strength. The adder 510 would then subtract one bit from this value to produce a conditioned count of <100>. Therefore, <100> is stored in second register 510 and then buffered to the CAM circuitry for use. It is preferred, however, that additional logic be added so that the conditioned count values supplied to the CAM core are not updated during a search operation.
[0046] To summarize, reference circuit 500 , in combination with the above-described digital circuitry, provides a reference sense amplifier for a CAM device. The pull-up strength thereof is controlled by a counter that is self-adjusting in order to identify the maximum pull-up strength of a PFET device which will still allow the CAM to function correctly (i.e., no false hit indications). Once the maximum pull-up strength is identified, that value is reduced and buffered so that the actual pull-up value used in the CAM devices is close, but not “too close” to the maximum value. In the event that actual process conditions effect a shift in maximum pull-up strength, this will also be identified and compensated for.
[0047] Although the above disclosed invention embodiments have been in the context of content addressable memories, it will be appreciated that the principles herein may be applicable to other memory storage devices. Furthermore, these principles are equally applicable to other types of devices in general where it is desirable to automatically adjust the margin of operating impedances to compensate for process and dynamic operating conditions.
[0048] While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. | A method for determining a desired operating impedance for a computer memory circuit is disclosed, the computer memory circuit having a plurality of discrete, selectively adjustable impedance values associated therewith. In an exemplary embodiment of the invention, the method includes applying, to a reference circuit, a test impedance value to a reference circuit. The test impedance value is controlled by a binary count. A determination is made, based upon the applied test impedance value, whether the reference circuit is in either a first state or a second state. The binary count is incremented if the reference circuit is in the first state and decremented if the reference circuit is in the second state. A condition is determined in which the reference circuit oscillates between the first state and said second state, and a pair of binary count values is stored. The desired operating impedance for the computer memory circuit corresponds to the lower of the stored pair of binary count values. | 6 |
CROSS REFERENCES TO RELATED APPLICATIONS
The present application claims priority to Japanese Patent Application JP 2009-194187 filed on Aug. 25, 2009, the entire contents of which is hereby incorporated by reference.
BACKGROUND
The present disclosure relates to a display device and a control method, and particularly to a display device and a control method that can control output of a timing signal optimally according to a viewer viewing three-dimensional stereoscopic video.
Three-dimensional stereoscopic video contents making stereoscopic visual perception of video possible have recently been drawing attention. A system for viewing three-dimensional stereoscopic video broadly includes two kinds of systems, that is, an eyeglass system and a naked eye system.
As an example of the eyeglass system, there is a system in which video for the left eye and video for the right eye are displayed on a time-division basis, which system is referred to also as a field sequential system. A viewer wears shutter eyeglasses provided with liquid crystal shutters, and perceives video for the left eye by the left eye and video for the right eye by the right eye. A parallax is provided to the video for the left eye and the video for the right eye. The parallax of the video for the left eye and the video for the right eye enables the viewer to perceive the video stereoscopically.
The eyeglass system needs to transmit a timing signal to the shutter eyeglasses in order to synchronize an operation of opening and closing the liquid crystal shutters with display of video for the left eye and video for the right eye. Radio communication by infrared radiation, radio waves and the like is generally employed to transmit and receive the timing signal.
The naked eye system separates video for the left eye and video for the right eye from each other by predetermined separating means to perceive three-dimensional stereoscopic video without wearing eyeglasses. The naked eye system includes a lenticular system employing a lenticular lens as separating means, a parallax barrier system employing a parallax barrier as separating means, and the like.
In certain naked eye systems, the position of the head part of a viewer viewing three-dimensional stereoscopic video is detected, and control is performed to change a range where stereoscopic vision is possible (see Japanese Patent Laid-Open Nos. 2002-300610 and Hei 10-333092, for example).
SUMMARY
Heretofore, when a timing signal is output to shutter eyeglasses in the eyeglass system, the direction of the output is fixed at one direction or fixed so as to spread at a wide angle, and is not changed to an optimum direction according to the position and number of viewers. In addition, the output level of the signal is fixed at a certain level, and the output level is not automatically changed according to the number of viewers or the like.
When the output direction is fixed at one direction and when the output level is fixed at a low level, no problem is presented as long as three-dimensional stereoscopic video is viewed by an individual or a small number of people in a small area. However, because of a limited viewing range, liquid crystal shutters cease to operate outside the viewing range, so that the three-dimensional stereoscopic video cannot be perceived.
On the other hand, when the output direction is fixed at a wide angle and when the output level is fixed at a high level, a wide viewing range is ensured. However, when the timing signal is output by infrared radiation, for example, another electronic device having an infrared receiving section may receive the timing signal and cause an erroneous operation. In addition, a needlessly high output level means unnecessary consumption of power, which is not desirable from a viewpoint of saving power.
It is desirable to control output of a timing signal optimally according to a viewer viewing three-dimensional stereoscopic video.
According to an embodiment, a stereoscopic video display system includes: a display device for displaying stereoscopic video; an image pickup element for generating image data; a position determiner for processing the image data received by the image pickup element to determine position information of at least one object identified in the image data; a plurality of light output sections each having one or more light transmitters, each light transmitter configured to output timing signals having a signal strength based on the determined position information; and at least one set of shutter eyeglasses including a light receiving section for receiving timing signals output from at least one of the light transmitters of the light output sections.
According to another embodiment, a display system includes: a display device; an image pickup element for generating image data; a position determiner for processing the image data received by the image pickup element to determine position information of at least one object identified in the image data; and a plurality of light transmitters configured to output timing signals, each timing signal output from each of the light transmitters having a signal strength based on the determined position information.
According to another embodiment, a system for controlling output of at least one light transmitter is provided. The system includes: an image pickup element for generating image data of at least one object positioned a distance away from the image pickup element; a position determiner for processing the image data received by the image pickup element to determine position information of the at least one object identified in the image data; and an light output controlling section for controlling output strength level of at least one light transmitter based on the determined position information.
According to another embodiment, a position information determination system comprising: an image pickup element for generating image data of at least one object positioned a distance away from the image pickup element; and a position determiner for processing the image data received by the image pickup element to determine position information of the at least one object identified in the image data. In this embodiment, the position information is relative to a position of the image pickup element and includes vertical position information, horizontal position information, and distance information for each of the objects.
According to an embodiment, the output of a timing signal can be controlled optimally according to a viewer viewing three-dimensional stereoscopic video.
Additional features and advantages are described herein, and will be apparent from the following Detailed Description and the figures.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a diagram showing an example of configuration of an embodiment of a three-dimensional stereoscopic video display system to which the is applied;
FIG. 2 is a diagram of assistance in explaining an infrared output section;
FIG. 3 is a diagram of assistance in explaining the infrared output section;
FIG. 4 is a diagram of assistance in explaining display control of three-dimensional stereoscopic video;
FIG. 5 is a diagram of assistance in explaining display control of three-dimensional stereoscopic video;
FIG. 6 is a diagram showing an example of functional configuration for timing signal transmission control; and
FIG. 7 is a flowchart of assistance in explaining the timing signal transmission control.
DETAILED DESCRIPTION
[Example of Configuration of Three-Dimensional Stereoscopic Video Display System]
FIG. 1 shows an example of configuration of an embodiment of a three-dimensional stereoscopic video display system to which the embodiment is applied.
The three-dimensional stereoscopic video display system of FIG. 1 includes a display device 11 , a recording and reproducing device 12 , a signal transmission cable 13 , and shutter eyeglasses 14 .
The display device 11 displays three-dimensional stereoscopic video on the basis of a video signal supplied from the recording and reproducing device 12 via the signal transmission cable 13 . In the present embodiment, the display device 11 is formed by an organic EL (Electro Luminescent) display, for example. Incidentally, the display device 11 may receive a video signal for three-dimensional stereoscopic video by not only receiving the video signal from the recording and reproducing device 12 but also receiving a broadcast signal, for example.
The display device 11 has infrared output sections (emitters) 21 R, 21 L, 21 U, and 21 D at a right end, a left end, an upper central part, and a lower central part, respectively, of the display device 11 . Incidentally, in the following, when each of the infrared output sections 21 R, 21 L, 21 U, and 21 D does not particularly need to be distinguished from the other, the infrared output sections 21 R, 21 L, 21 U, and 21 D will be referred to simply as an infrared output section 21 .
The infrared output section 21 is for example composed of three transmitters 22 1 to 22 3 arranged so as to correspond to three directions as shown in FIG. 2 . The infrared output section 21 outputs a timing signal by infrared radiation with a predetermined angle as a radiation range which predetermined angle has a direction indicated by an arrow in FIG. 1 as a center thereof. Incidentally, each of the three transmitters 22 1 to 22 3 can select (control) an output level to be one of “strong” and “weak,” as shown in FIG. 3 .
The recording and reproducing device 12 reproduces the three-dimensional stereoscopic video (contents) stored on a recording medium, and supplies the video signal to the display device 11 via the signal transmission cable 13 . The recording and reproducing device 12 for example corresponds to a recorder, a personal computer or the like having an optical disk such as a DVD (Digital Versatile Disc), a Blu-Ray Disc (trademark) or the like, a hard disk and the like as recording media.
The shutter eyeglasses 14 are worn by a viewer when viewing the three-dimensional stereoscopic video. The shutter eyeglasses 14 have a light receiving section 31 for receiving the timing signal output from the infrared output section 21 of the display device 11 . The shutter eyeglasses 14 also have a shutter 32 L for the left eye and a shutter 32 R for the right eye. The shutter eyeglasses 14 perform an operation of opening and closing the shutter 32 L for the left eye and the shutter 32 R for the right eye in synchronism with the received timing signal.
[Display Control of Three-Dimensional Stereoscopic Video]
Display control of three-dimensional stereoscopic video will be described with reference to FIG. 4 and FIG. 5 .
Video for the left eye and video for the right eye are displayed on the display device 11 on a time-division basis. Specifically, as shown in FIG. 4 , the video for the left eye and the video for the right eye are displayed alternately, such as video L 1 for the left eye, video R 1 for the right eye, video L 2 for the left eye, video R 2 for the right eye, . . . .
The shutter eyeglasses 14 alternately repeat two states, that is, a state of the shutter 32 L for the left eye being opened and the shutter 32 R for the right eye being closed and a state of the shutter 32 L for the left eye being closed and the shutter 32 R for the right eye being opened, in synchronism with the timing signal.
As shown in FIG. 5 , the display device 11 displays the video for the left eye and the video for the right eye with a black display period for preventing interference (crosstalk) between the video for the left eye and the video for the right eye interposed therebetween. The black display period includes a V-blanking period of the video signal.
A signal indicating selection of the shutter 32 L for the left eye is output from the infrared output section 21 in a period of display of the video for the left eye, and a signal indicating selection of the shutter 32 R for the right eye is output from the infrared output section 21 in a period of display of the video for the right eye. The selection of the shutter 32 L for the left eye or the shutter 32 R for the right eye is changed at the beginning of a black display period. The example of FIG. 5 shows that the shutter 32 L for the left eye is selected when the timing signal is high and that the shutter 32 R for the right eye is selected when the timing signal is low.
The shutter eyeglasses 14 perform an operation of switching between the shutter 32 L for the left eye and the shutter 32 R for the right eye according to the received timing signal. The operation of switching between the shutter 32 L for the left eye and the shutter 32 R for the right eye is completed in a black display period. A state of the shutter 32 L for the left eye being opened is retained in a period of display of the video for the left eye, and a state of the shutter 32 R for the right eye being opened is retained in a period of display of the video for the right eye.
As a result, as shown by arrows in FIG. 4 , only the video for the right eye is input to the right eye of the viewer, and only the video for the left eye is input to the left eye of the viewer. A parallax is provided to the video for the left eye and the video for the right eye. The parallax of the video for the left eye and the video for the right eye enables the viewer to perceive the video stereoscopically.
[Timing Signal Transmission Control of Display Device 11 ]
FIG. 6 shows an example of functional configuration for timing signal transmission control of the display device 11 .
An image pickup element 42 is disposed in substantially a central part of an organic EL panel 41 included in the display device 11 on a back side of the organic EL panel 41 . The image pickup element 42 for example has 640×480 pixels referred to as a VGA (Video Graphics Array). The image pickup element 42 is formed by a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor) sensor or the like.
The image pickup element 42 picks up an image of a viewer viewing the three-dimensional stereoscopic video by receiving light passed through free space parts of a plurality of pixel circuits arranged in a row and a column direction in the organic EL panel 41 . Because the image pickup element 42 is disposed in substantially the central part of the organic EL panel 41 , the image pickup element 42 can determine the position of the viewer accurately (uniformly). The image pickup element 42 supplies an image obtained as a result of the image pickup to a viewer information generating section 43 .
The viewer information generating section 43 detects the position and the number of viewers viewing the three-dimensional stereoscopic video by performing predetermined image processing on the image supplied from the image pickup element 42 . The viewer information generating section 43 supplies the position and the number of viewers viewing the three-dimensional stereoscopic video as position information and head count information to an infrared output determining section 44 .
The viewer position information for example includes three parameters of a vertical direction (top, middle, and bottom), a horizontal direction (left, middle, and right), and a distance (far and near). For example, when it is detected that a viewer is located far on a left side with respect to the display device 11 , information indicating that “vertical direction, horizontal direction, distance”=“middle, left, far” is output as position information. In addition, for example, when it is detected that a large number of viewers are viewing the three-dimensional stereoscopic video in a state of being spread on each of a right side, a center, and a left side with respect to the display device 11 , information indicating that “vertical direction, horizontal direction, distance”=“middle, left middle right, far” is output as position information.
On the other hand, the viewer head count information for example includes three parameters of large, medium, and small. For example, “small” is output as head count information when one viewer is viewing the three-dimensional stereoscopic video, “medium” is output as head count information when two or three people are viewing the three-dimensional stereoscopic video, and “large” is output as head count information when four or more people are viewing the three-dimensional stereoscopic video.
The position and number of viewers can be detected by image processing as follows, for example. Viewers viewing the three-dimensional stereoscopic video necessarily wear the shutter eyeglasses 14 , which are special eyeglasses. Accordingly, the position and number of viewers can be detected by detecting the number and size of shutter eyeglasses 14 by pattern matching or the like. In addition, the position and number of viewers may be detected by face detection processing or the like commonly performed in a digital camera or the like.
Incidentally, the detection and output of the position information and the head count information as described above are a mere example.
The infrared output determining section 44 determines the turning on/off of output and output level for the infrared output sections 21 R, 21 L, 21 U, and 21 D from the position information and the head count information supplied from the viewer information generating section 43 . In this case, the turning on/off of output of the infrared output sections 21 R, 21 L, 21 U, and 21 D corresponds to determination of an output direction of infrared output.
The infrared output determining section 44 assigns the infrared output section 21 R for viewers situated in a right direction as viewed from the display device 11 and assigns the infrared output section 21 L for viewers situated in a left direction as viewed from the display device 11 . In addition, the infrared output determining section 44 assigns the infrared output section 21 U for viewers situated at a long distance in a direction of the center of the display device 11 and assigns the infrared output section 21 D for viewers situated at a short distance in the direction of the center of the display device 11 .
For example, when information indicating that “vertical direction, horizontal direction, distance”=“middle, middle, near” is output as position information and “small” is output as head count information, the infrared output determining section 44 determines that only the infrared output section 21 D is to produce output at an output level “weak.”
In addition, for example, when information indicating that “vertical direction, horizontal direction, distance”=“middle, left middle right, far” is output as position information and “large” is output as head count information, the infrared output determining section 44 determines that all the infrared output sections 21 are to produce output at an output level “strong.”
The infrared output determining section 44 supplies information on the determined infrared output sections 21 as output section selecting information to an infrared output controlling section 45 .
The infrared output controlling section 45 controls the infrared output sections 21 R, 21 L, 21 U, and 21 D on the basis of the output section selecting information supplied from the infrared output determining section 44 .
[Flowchart of Timing Signal Transmission Control]
FIG. 7 is a flowchart of timing signal transmission control. This process can be started so as to coincide with a start of display control of three-dimensional stereoscopic video, for example.
First, in step S 1 , the image pickup element 42 picks up an image of viewers viewing three-dimensional stereoscopic video. The image obtained as a result of the image pickup is supplied to the viewer information generating section 43 .
In step S 2 , the viewer information generating section 43 detects the position and number of the viewers on the basis of the image supplied from the image pickup element 42 . The viewer information generating section 43 supplies a result of the detection as position information and head count information to the infrared output determining section 44 .
In step S 3 , the infrared output determining section 44 determines the turning on/off of output and an output level for each infrared output section 21 from the position information and the head count information supplied from the viewer information generating section 43 . A result of the determination is supplied as output section selecting information to the infrared output controlling section 45 .
In step S 4 , the infrared output controlling section 45 controls the infrared output sections 21 R, 21 L, 21 U, and 21 D on the basis of the output section selecting information supplied from the infrared output determining section 44 .
In step S 5 , the infrared output sections 21 R, 21 L, 21 U, and 21 D output a timing signal by infrared radiation at the set output levels under control of the infrared output controlling section 45 .
After step S 5 , the process returns to step S 1 to repeat the process of steps S 1 to S 5 described above until the display control of the three-dimensional stereoscopic video is ended.
As described above, the display device 11 detects the viewing position and number of viewers viewing three-dimensional stereoscopic video, and controls the output of the plurality of infrared output sections 21 according to a result of the detection. Thereby, the output of the timing signal can be controlled optimally according to the viewers viewing the three-dimensional stereoscopic video.
In addition, the display device 11 can perform control so as not to send out the timing signal from a infrared output section 21 for a direction without a viewer, and control (vary) output level according to the distance of viewers. Thereby, power consumption of the display device 11 can be reduced. In addition, erroneous operation of a device operating by receiving infrared rays, which device is installed in the vicinity of the display device 11 , can be prevented.
Further, because the display device 11 has the plurality of infrared output sections 21 corresponding to the respective directions such as the right direction, the left direction, and the center direction, for example, the display device 11 can widen a range of output of the timing signal so as to correspond to a viewing angle of a screen.
In the foregoing embodiment, the turning on/off of infrared output and output level thereof are controlled in units of the infrared output sections 21 . However, because the infrared output sections 21 are formed by three transmitters 22 1 to 22 3 as shown in FIG. 2 , the turning on/off and output level of each of the three transmitters 22 1 to 22 3 of the infrared output sections 21 may also be controlled.
In addition, in the present embodiment, the output level is set to two steps of “strong” and “weak.” However, the output level may be set to three or more steps. Alternatively, the output level may be set to an arbitrary output level such as an output level corresponding to a distance to a detected viewer.
In the foregoing embodiment, description has been made of a case where the display device 11 is an organic EL display. However, other embodiments are applicable not only to organic EL displays but also displays employing an optically transmissive display panel that allows the image pickup element 42 to pick up an image even when the image pickup element 42 is disposed on the back side of the display panel. Incidentally, in a case of a non-transmissive display panel, the image pickup element 42 can be disposed in a frame part on the periphery of the display panel.
Further, while the timing signal is output by infrared radiation in the foregoing embodiment, other radio communications by radio waves and the like can be adopted. In addition, the number of infrared output sections 21 provided to the display device 11 is not limited to four, but may be one, two, or five or more.
It is to be noted that in the present specification, the steps described in the flowchart may of course be performed in time series in the described order, but may be performed in parallel or in necessary timing when a call is made, for example, without being necessarily handled in time series.
In the present specification, a system refers to an entire device formed by a plurality of devices.
It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims. | A stereoscopic video display system includes a display device for displaying stereoscopic video, an image pickup element for generating image data, a position determiner for processing the image data received by the image pickup element to determine position information of at least one object identified in the image data, and a plurality of light output sections each having one or more light transmitters. Each light transmitter is configured to output timing signals having a signal strength based on the determined position information. The stereoscopic video display system also includes at least one set of shutter eyeglasses including a light receiving section for receiving timing signals output from at least one of the light transmitters of the light output sections. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to techniques in the field of magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). The present invention also relates to techniques for measuring the spatial distribution of the electrical properties of substances such as electrolyte solutions, the tissues of a living body and human tissues by the use of MRI or MRS. The present invention relates also to techniques for measuring the spatial distributions of the currents within these substances.
[0003] 2. Description of the Prior Art
[0004] Magnetic resonance signals are high-frequency signals, typically on the order of microvolts, which have weak frequencies produced by the precession of atomic nuclei (spins) in a static magnetic field. The frequency of the precession is determined by the magnetic field strength and the type of nucleus in question. The spins are aligned by the homogenous static magnetic field, and are excited by the application of an RF field, with the resulting magnetic resonance signals being detected as a voltage with a resonant coil (antenna).
[0005] An MR image is abbreviated MRI, and the method for acquiring it is called MR imaging which is abbreviated MRI. Further, MR spectral curve is referred to as an MR spectrum which is abbreviated MRS, and the acquisition of it or the method for acquiring it is called MR spectroscopy, which is abbreviated MRS.
[0006] Since R. Damadian found in the early 1970s that the spin-lattice relaxation time T1 and the spin-spin relaxation time T2 vary with tissues significantly, and tumorous tissues have extremely longer relaxation times than normal tissues (R. Damadian, “Tissue detection by nuclear magnetic resonance.” Science vol. 171: pp.1151-1153, published in 1971), the relaxation times T1 and T2 have been recognized as very important parameters in developing and designing magnetic resonance imaging systems and obtaining and evaluating magnetic resonance images and spectra.
[0007] The relaxation time T1 is the time constant required for the spins excited in a static magnetic field to return to their initial state in which they can be excited again. Accordingly, if T1 of the tissues of a living body or the like (examination subject) is particularly long, then a correspondingly longer time is needed for obtaining the magnetic resonance signals by repeating the excitation, returning the spins to the initial state, and for obtaining MRI or MRS by performing calculations such as two-dimensional Fourier transform or one-dimensional Fourier transform with a computer. In case of a clinical MRI apparatus, the patient, who is not allowed to move during the image pickup, is more burdened. Further, the number of patients who can be imaged over a given time is decreased. Accordingly, it is generally considered better for T1 to be shorter.
[0008] The relaxation time T2 is the time constant from a time when many spins are excited in resonance with the RF field (i.e., the field having the same frequency as the frequency of the precession relative to the magnetic flux density of the static magnetic field around the spins), so that the phases of the precessions are uniform and can be detected macroscopically as an induced electromotive force by an external resonance coil, to when the phases become irregular and non-uniform, so that the spins cannot detected. Accordingly, in order to obtain the signals, it is better in many cases for T2 to be long, but there are also many cases where, even if T2 is short, it suffices if the signals are obtained, by an appropriate signal obtaining technique, for instance immediately after the excitation thereof.
[0009] Typically, T1 of the gray matter of the brain of the human body is 1.0 when it is measured in a magnetic field of 1T. Further, typically, T2 of the gray matter of the human brain is 0.1. It has been conventionally believed that there is no method or means for changing these relaxation times T1 and T2 in a given static magnetic field (of 1.0 T, 1.5 T or the like) and at a given temperature (substantially 37° C. of the human body) unless some chemical substance or the like is introduced into the human body.
[0010] More specifically, it is known that the ions of a magnetic material such as a transition metal and lanthanide ions have unpaired electronic spins which have magnetic moments several hundreds of times as large as protons, and thus have strong relaxation effects. As an application example of such substances, the injection of a gadolinium compound, which is a paramagnetic material, into the circulatory system of an examination subject is widely practiced in the field of clinical MRI. If a gadolinium compound is introduced into the tissue of a living body, it has a relatively larger shortening effect on T1, which is originally long, than on T2 which is originally short.
[0011] In other words, if the gadolinium compound is introduced into a vein, then it is absorbed into the blood or the brain tissue or the like if the cerebral blood vessel barrier has been destroyed by a cerebral infarction or the like. This selectively shortens the T1 of the tissue, so that the site of disease or the like can be selectively imaged or depicted in a T1-weighted image (that is, an image which is generated, by obtaining successive sets of magnetic resonance signals by repeating the excitation after each return of the spins to the initial state.) In such an image a substance which has a short T1 and is therefore apt to return to the initial state in which, even if previously excited, it can be excited again, produces a higher amplitude signal and thus appears brighter in the image.
[0012] A T2-weighted image is generated from a signal that is not obtained immediately after the excitation, but is obtained as a dark signal after waiting for a substance with a shorter T2 to become irregular and non-uniform in phase by the T2 relaxation and become undetectable.
[0013] Further, in the middle 1960's, E. O. Stejskal and J. E. Tanner developed a diffusion measurement method by nuclear magnetic resonance that uses a motion probing gradient (MPG) pulses. [E. O. Stejskal and J. E. Tanner, “Spin diffusion measurements: spin-echoes in the presence of time-dependent field gradient.” J. Chem. Phys. Vol. 42: pp. 288-292, published in 1965].
[0014] This is a method of measuring the magnitude of the movement of spins as a diffusion coefficient by utilizing the fact that, as long as the spins perform a precession at a stationary position, no influence is exerted even if two gradient magnetic fields which are identical in magnitude but opposite in direction are successively applied as MPG pulses, but, if the spins are moved by the diffusion, then the phases are made irregular and non-uniform eventually by the application of the MPG pulses. The MPG pulses may be applied by making them identical with each other in magnitude and direction and putting 1800 RF pulses between them.
[0015] Further, D. Le Bihan, etc. introduced MRI techniques that incorporate MPG pulses into imaging sequences of MRI in mid-1980s. [D. LeBihan, E. Breton, D. Lallemand, P. Granier, E. Cabanis and M. Laval-Jeantet, “MR imaging of intravoxel incoherent motions: application to diffusion and perfusion in neurological disorders.” Radiology Vol. 161: pp. 401-407, published in 1986].
[0016] Since then, the diffusion-weighted MRI techniques have been widely used as a very important imaging methods because, for important lesions like acute cerebral infarctions which cannot be depicted, unless two or three days lapse after the beginning of the disease, by T1-weighted imaging or T2-weighted imaging. Using diffusion-weighted imaging, these important lesions are imaged 20 to 30 minutes after the development of the disease.
[0017] The diffusion of certain molecules in the same substance, such as water molecules diffusing in water, is called self-diffusion. Accordingly, the diffusion coefficient of a substance itself refers to the self-diffusion coefficient. Self-diffusion is originally isotropic. However, among the movements of spins in living bodies, etc., not only do movements due to diffusion occur, but also some movements due to blood flow occur. More precisely, therefore, the measured diffusion coefficient of the water molecules is called the apparent diffusion coefficient (ADC). In particular, if the gradient factor attenuation value (which is sometimes abbreviated b-factor) that is determined dependent on the magnitude, the length in time and the pulse interval of each of the MPG pulses) is very small, the detection of only the movement due to the diffusion of the spins is very difficult, because the movement of the spins due to the blood flow, etc. also is detected. However, MPG pulses of such a degree that are in practical use in ordinary diffusion-weighted imaging sequences in clinical MRI, etc. at present can make the ADC value almost equal to the diffusion coefficient by sufficiently increasing the b-factor. Concerning the b-factor, details are given in the above-mentioned literature of Le Bihan, etc.
[0018] Further, a method of making a measurement by magnetic resonance while flowing an electric current through an electrolyte solution, is disclosed in U.S. Pat. No. 5,757,185.
[0019] The aforementioned patent states that by flowing an electric current, changing with time, the motion of the ions or molecules caused only by the electric current can be detected by nuclear resonance, with respect to the direction in which the gradient magnetic field is applied. Motion caused by diffusion is not detected.
[0020] There is no discussion in the aforementioned patent that applying an electric current through an electrolyte solution has any effect on T1 or T2. Moreover, the technique according to the aforementioned patent for detecting the motion of the ions or molecules produced by an electric field and thus differs from known techniques for detecting the self-diffusion that develops isotropically.
SUMMARY OF THE INVENTION
[0021] It is an object of the present invention to provide a technique for markedly shortening T1 or T2 of a water-containing substance such as an electrolyte solution, the tissues of a living body or human tissues without using an intravenous injection or the like of a paramagnetic material such as a gadolinium compound or the like.
[0022] Another object of the present invention is to provide a technique for markedly increasing the ADC of a water-containing substance, so that the diffusion-weighted sensitivity is enhanced, in the context of a diffusion-weighted MRI or diffusion-weighted MRS.
[0023] Still another object of the present invention is to provide a technique for measuring the spatial distribution of the electrical properties of a water-containing substance by the use of MRI or MRS.
[0024] Still another object of the present invention is to provide a technique for measuring the spatial distribution of the electric currents in the interior of a water-containing substance by the use of MRI or MRS.
[0025] The first object is achieved in accordance with the present invention wherein, by applying an electric current through a water-containing substance, T1 or T2 of the substance is reduced.
[0026] The first object also is achieved in accordance with the present invention in a method for obtaining magnetic resonance images or spectra wherein a water-containing substance is placed in a static magnetic field, and, by a radio-frequency magnetic field, nuclear spins in the substance are excited to generate magnetic resonance signals, and wherein, by applying an electric current through said substance, the T1 or T2 of the substance is reduced.
[0027] The second object is achieved in accordance with the present invention wherein by applying an electric current through a water-containing substance, the apparent diffusion coefficient (ADC) of the substance is increased.
[0028] The second object also is achieved in accordance with the present invention also lies in a method for obtaining a magnetic resonance image or spectrum wherein a water-containing substance is placed in a homogeneous static magnetic field, and, by a radio-frequency magnetic field, nuclear spins in the substance are excited to generate magnetic resonance signals, and wherein, by applying an electric current through the substance, the ADC of the substance is increased.
[0029] The third and fourth objects are achieved in accordance with the present invention in a method for obtaining a magnetic resonance image or spatial information representing an electrical property of a water-containing substance wherein a T1-weighted, T2-weighted or diffusion-weighted magnetic resonance image, or localized magnetic resonance spectra is/are obtained, while applying an electric current through the substance, and wherein these images or spectra are compared to images or localized spectra obtained without applying the electric current.
[0030] The water-containing substance can be an electrolyte solution or the tissues of a living body.
[0031] The first object also is achieved in accordance with the present invention in an apparatus for obtaining a magnetic resonance image of a water-containing substance having a basic field magnet which generates a homogeneous static magnetic field, an RF system which generates a radio-frequency field, a gradient system which generates gradient magnetic fields, and a computer which generates an image from the received magnetic resonance signals and an arrangement for applying an electric current through the substance while the nuclear spins are processing, to reduce T1 or T2 of the substance.
[0032] A further embodiment of the present invention is an apparatus for obtaining a magnetic resonance image of a water-containing substance having a basic field magnet which generates a homogeneous static magnetic field, an RF system which generates a radio-frequency magnetic field, a gradient system which generates gradient magnetic fields, and a computer which generates an image from the received magnetic resonance signals, and an arrangement for applying motion probing gradient (MPG) pulses through the substance, and an arrangement for applying an electric current through the substance, to increase the ADC of the substance as the magnetic resonance signals are being generated and received.
[0033] A further embodiment of the present invention is a method for obtaining spatial information, by magnetic resonance, representing the internal electric current evoked in a water-containing substance, wherein T1-weighted or T2-weighted or diffusion-weighted magnetic resonance images or localized magnetic resonance spectra while an internal current is caused to flow in the substance, and wherein images or localized spectra are obtained without an internal current flowing in the substance, which are compared to the images or the localized spectra obtained with the internal current.
[0034] Even if the internal current is evoked in the tissue of a living body instead of being externally applied, the present invention can be practiced. In particular, even if the electric current in the tissue of a living body is evoked by an external stimulus to the living body tissues or by the internal brain activity in the living body, the present invention can be practiced.
[0035] The main cause for the relaxation phenomenon of the spins excited in water lies in the dipole-dipole interaction. One water molecule has two protons. Each rotates with a positive charge, as a result of which a magnetic field is emitted as a magnetic dipole having an N pole and an S pole. Moreover, the individual protons are each disposed within the magnetic fields emitted by surrounding protons. Further, each water molecule is experiencing thermodynamic molecular motion (Brownian motion). The correlation time (i.e., the time constant when the state at a certain instant is lost by the thermodynamic molecular motion, which becomes shorter as the thermodynamic molecular motion increases of the thermodynamic molecular motion of water existing as a liquid is much shorter than the cyclical period of the spin precession.
[0036] If the correlation time of the thermodynamic molecular motion reaches the same order as that of the cyclical period of the spin precession, many protons are subjected to radio-frequency magnetic fields generated by the other protons, on the same order as that of the precessions, and accordingly on the same order as the resonance frequencies but having various frequencies on the same order as the precessions, and accordingly on the same order as that of the resonance frequencies, but the protons exhibit various frequencies, like white noise. Then, the spins excited by the radio-frequency magnetic fields with a single resonant frequency from the outside cannot keep the excitation state any longer and thus become relaxed. This is the TI relaxation caused by the dipole-dipole interaction.
[0037] Further, if the correlation time of the thermodynamic molecular motion becomes very long, then one proton also is disposed in a static magnetic field produced by the magnetic fields emitted from the other protons, so that the precession which would otherwise occur at a cyclical period due to the constant external magnetic field, is disturbed by the existence of many surrounding protons, and thus becomes irregular and non-uniform. This is the T2 relaxation caused by the dipole-dipole interaction.
[0038] On the other hand, one water molecule has two protons which have positive charges and one oxygen nucleus which has a negative charge, bonded at an angle of about 105°, and therefore, the molecule itself is a weak electric dipole. For example, in saline solution, sodium and chlorine exist in an ionized state, and the electric dipoles of the water molecule are attracted or repulsed by the dissociated ions, forming, around the individual electrolytic ions, many semi-stable structures, called hydration shells, containing many water molecules. Semi-stability refers to the state in which the total number of the electric dipoles does not change significantly with time, but replacement of the dipoles by surrounding dipoles is constantly taking place. Also in human body tissue, sodium ions of about 150 mM exist in the extracellular fluid and potassium ions of about 150 mM exist in the intracellular fluid, so that, around these ions, hydration shells are formed.
[0039] When an electric current is applied, the electrolytic ions move together with the hydration shells in a manner taking many water molecules with them. It is believed that, in this case, the thermodynamic molecular motion of the water molecules is restricted by the movement of the electrolytic ions, so that the correlation time is changed. As a result, the above-mentioned T1 relaxation and T2 relaxation based on the above-mentioned dipole-dipole interaction are caused, and T1 and T2 become markedly shorter.
[0040] Further, it is believed that, if an electric current is applied, the electrolytic ions move with the hydration shells in a manner taking many water molecules with them, as a result of which the movement of the water molecules is caused, and thus the ADC is remarkably increased. Here, the important feature pertaining to the increase of the ADC in the present invention is that the increase is developed isotropically. The mechanism therefor is believed to be in that the replacement, in a direction perpendicular to the movement, of the water molecules with the surrounding water molecules, which is caused by the movement of the hydration shells, occurs isotropically. Therefore, it is believed that the increase of the ADC in the present invention is also due to the fact that the diffusion coefficient substantially increases.
[0041] Further, T1-weighted or T2-weighted images or diffusion-weighted images can be obtained while applying an electric current through a water-containing substance, and a comparison is made between these images and corresponding control images obtained without applying an electric current. Such a comparison can be subtraction or division of attributes the images, or image calculations such as statistical inspection, etc. among many images. The tissues through which the electric current flow is higher exhibit a greater T1 shortening effect or T2 shortening effect or ADC increasing effect according to the present invention. Therefore, images in which the distribution of the electrical conductivity is represented can be obtained.
[0042] Further, according to the present invention, T1-weighted images can be obtained while applying an electric current through a water-containing substance, then T1 is shortened, as a result of which the intensity of the signals obtained is markedly high, and therefore the obtained images are bright. Alternatively, a T1-weighted image can be obtained with a “conventional” brightness but the scan can be completed in a shorter time as a whole in connection with MRI or MRS. Accordingly, in a clinical MRI apparatus, the stores the patients can be markedly reduced and patient throughput can be increased.
[0043] Further, according to the present invention, diffusion-weighted images can be obtained, while applying an electric current through a water-containing substance, causing the ADC to be markedly increased, as a result of which images in which the contrast of the signals obtained is markedly strong are obtained.
[0044] The present invention is based on the finding that, when an electric current exists in a water-containing substance, T1 or T2 is shortened, or ADC is increased. The electric current which yields such effects need not be applied from outside the subject, but can be evoked internally, such as in the case of the water-containing substance being tissue in a living body, such as brain tissue.
[0045] More specifically, the brain evokes an electric current internally in response to an external stimulus or by internal brain activity. In a living body, the nerve tissues of the brain or the like are relatively easy to supply with an electric current, and as a result of the application of the electric current, a natural biomagnetic field is generated. The intensity of such electric fields emitted in the surrounding electrolyte, however, is small. Further, the duration of the electrical activities is very short in many cases.
[0046] Thus, T1-weighted or T2-weighted or diffusion-weighted magnetic resonance images or local magnetic resonance spectra are obtained when an internal electric current exists and when no internal electric current exists, and, between the data obtained when the internal electric current exists and the data obtained when no internal electric current exists, a comparison is made by performing subtractions and divisions or, among many datasets, a comparison is made by performing statistical inspection, etc. This allows information pertaining the spatial distribution of the internal currents and/or magnetic resonance images which represent the spatial distribution of the internal currents to be obtained.
DESCRIPTION OF THE DRAWINGS
[0047] [0047]FIG. 1 is a block diagram showing the structure of the apparatus according to an embodiment.
[0048] [0048]FIG. 2 is a chart showing an example of the diffusion-weighted spin echo imaging sequence according to an embodiment of the present invention.
[0049] [0049]FIG. 3 is a chart showing an example of the diffusion-weighted MRS obtaining sequence according to an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0050] [0050]FIG. 1 is a block diagram showing the basic structure of an apparatus according to an embodiment of the present invention.
[0051] Referring to FIG. 1, a phantom sample of an electrolyte solution 5 is placed in the static magnetic field of a horizontal superconducting magnet 1 of an MRI apparatus. The phantom sample 5 is connected to a current source 6 through a lead wire 7 . The MRI apparatus also has a gradient magnetic field coil assembly 2 and a radio-frequency coil 4 . The gradient magnetic field coil assembly 2 is supplied with an electric current from an electrical power supply 3 for the gradient magnetic field coil or coils, and produces gradient magnetic fields in the homogeneous static magnetic field volume of the magnet 1 .
[0052] The gradient magnetic field power supply 3 is operated by a command sent from an unillustrated man-machine interface. Power is supplied to the radio-frequency coil 4 in a transmit mode via a transmit/receive changeover switch 8 from a radio-frequency amplifier 10 , causing spins to be excited in the phantom sample 5 . Conversely, in a reception mode the magnetic resonance signals generated by the proton spins are detected as an induced electromotive force by the radio-frequency coil 4 and are sent to a computer 11 through the transmit/receive changeover switch 8 and an amplifier stage 9 (for example a pre-amplifier and an intermediate amplifier). After known data processing such as Fourier transformation, etc., In the computer 11 , data are supplied to a display 12 as MRI or MRS data. The radio-frequency amplifier 9 is also operated by the command sent from the man-machine interface.
[0053] According to the present invention, the electrical current applied from outside to a tested subject (in case of FIG. 1, the phantom sample 5 ) is an alternating current of 10 Hz or below, preferably 2 Hz or below, or a direct electric current. The lower the frequency, the larger the T1 shortening effect, the T2 shorting effect and the ADC increasing effect become, and the use of DC current is the most effective. In case of cellular tissues constituting a living body, AC currents are easier to conduct than DC currents, and a suitable frequency range thereof is 0.1 to 1.0 Hz.
[0054] In the present invention, if the subject is a human body the density of the electric current applied from the outside must be set to 50 mA/cm 2 or below to avoid a possible danger. The current density should preferably is 10 mA/cm 2 or below and more preferably is 5 mA/cm 2 or below for non-invasion measurement.
[0055] On the other hand, in most cases the higher the current density is, the larger the T1 shortening effect and the ADC increasing effect will be. The practical current density range is 0.02 to 2.0 mA/cm 2 and preferably is 0.05 to 1.0 mA/cm 2 .
[0056] However, these current values should be set to lower values for safety if the invention is applied to a human body in the medical field, since the brain and the heart are organs which generate currents by themselves. Also in the fields of biology, veterinary medicine, botany, etc., the present invention exhibits marked effects as long as a water-containing substance is the subject, for shortening T1 or T2 or increasing ADC to perform MRI or MRS. When the present invention is employed for measuring the physical properties of water-containing substances other than the human body, allowable current values appropriate for the respective substances may of course be employed.
[0057] In the present invention, an electric current can be applied through an electrically conductive paste by the use, as electrodes, of non-magnetic metal foils, graphite plates or carbon powder-containing rubber plates. Where the tested subject is covered by an electrically conductive body, then radio-frequency eddy currents are caused to flow though the conductive body by the external radio-frequency field used for the excitation of spins, and thus the external RF field does not reach the interior of the tested subject. In an exemplary embodiment of the inventive method, an electrically conductive rubber band is placed around the wrist as one electrode, and another electrically conductive rubber band is placed around the upper arm as the other electrode, and an electric current is caused to flow between the wrist and the upper arm.
[0058] An external DC or low-frequency AC power source unit for this current, which has a magnetic component, cannot be brought near the MRI apparatus or MRS apparatus. A current-regulated power source would produce a location at the tested subject, at which the electric current flows in a concentrated manner, and thus for safety a voltage-regulated power source is better in many cases. The wire extending from the power source to the electrode in the strong magnetic field will experience a force according to Fleming's left-hand rule depending on the magnitude of the electric current, and therefore this conductor is preferably a twisted pair so that the current flows in opposite directions parallel to the static magnetic field as much as possible, or the conductor can be rigidly fixed in the magnetic field.
[0059] In order to obtain diffusion-weighted image data, it is necessary to use MPG pulses as shown in, e.g., FIG. 2. Referring to FIG. 2, RF indicates the RF pulses. Further, Gs indicates the output of the gradient magnetic field coil for slice selection. Further, Gr indicates the output of the gradient magnetic field coil for reading-out signals. Gp indicates the output of the gradient magnetic field coil for phase encoding. EC indicates the electric current applied though the tested subject.
[0060] Referring to FIG. 2, the RF pulses are applied in a direction perpendicular to the static magnetic field. If so, the many individually processing spins existing in the water-containing substance, which were directed as a whole in the direction of the static magnetic field, flip by 90° as a whole in resonance with the RF pulses. This is the first 90° pulse shown in FIG. 2.
[0061] If the second pulse (a 180° pulse twice having twice the amplitude of the 900 pulse in the example of FIG. 2) is applied to the spins thus excited, then an echo signal is generated for the same time as the time Te/2 ranging from the application of the first excitation pulse (i.e., the 90° pulse) to the application of the second pulse and after a time Te lapses from the application of the first excitation pulse. This echo signal is called spin echo, and the time Te is called echo time.
[0062] At the instant when the 90° pulse or the 180° pulse is applied, pulses of the gradient magnetic field Gs for slice selection are applied. As is known as gradient magnetic field is a magnetic field which gives a linear gradient to the static magnetic field, and the spins perform precessions only at the frequency determined depending on the magnetic field intensity. Thus, it follows that, with respect to the radio-frequency field having a fixed frequency, the excitation by the 90° pulse and the generation of the echo signal by the 180° pulse each take place only at specific position with respect to one axis in space. This is the slice selection achieved by the gradient magnetic field Gs.
[0063] Next, when the echo signal which is generated after the time Te lapses is read out (in other words, the echo signal is detected as an induced electromotive force by the radio-frequency coil 4 ), the gradient magnetic field Gr is applied. This gradient magnetic field Gr is applied to the signal source, i.e., all the spins are differently spatially distributed. The gradient magnetic field Gr is a magnetic field which gives a linear gradient to the second spatial axis (i.e., an axis different from the axis for which the slice selection was made).
[0064] By the gradient magnetic field Gr, the echo signal from a specific slice is modulated with the frequency determined depending on the second spatial axis, and the radio-frequency coil 4 detects the echo signal as one signal containing the various frequencies of all of the spins in the slice. This signal is a signal on a time axis, that is, a signal which varies with time. When this signal is Fourier-transformed by the computer ii, then it is represented as a signal on a frequency axis. The frequency axis corresponds to the second spatial axis, so that the distribution of the spins along the second axis is identified.
[0065] Referring to FIG. 2, the MPG pulses are applied, by the use of the gradient magnetic field Gr, in the same direction with the 180° pulse interposed there between. The MPG pulses have a function as already mentioned. When readout of the echo signal is completed, the 90° pulse is applied again. The time from the application of the first 90° pulse to the application of the second 90° pulse is the repetition time Tr.
[0066] During the period from the excitation by the second 90° pulse to the second readout, the gradient magnetic field Gp is applied for a fixed time with a size changed by a fixed amount from the size applied at the first time. If the gradient magnetic field Gp is applied for a fixed time to the spins which perform precessions at a fixed frequency, then the precessions of the spins advance by a phase determined by the magnitude of the gradient magnetic field Gp. This gradient magnetic field Gp is a gradient magnetic field in the direction of the third spatial axis.
[0067] If signals are obtained repeatedly, the changes in the phase of the echo signal read out in each repetition represents the spatial distribution of the spins with respect to the direction of the third axis. Thus, if a Fourier transformation is made by the computer 11 with respect to the direction of the third axis, the phase axis corresponds to the third spatial axis, and thus the distribution of the spins along the third axis is identified. This is the diffusion-weighted spin echo imaging sequence.
[0068] The computer 11 performs a two-dimensional Fourier transformation with respect to one dataset comprising several echo signals measured repeatedly, and supplies the result to the display 12 as a magnetic resonance image.
[0069] It will be understood that if diffusions are not to be detected, the MPG pulses are not applied.
[0070] Next, referring to FIG. 3, three gradient magnetic fields Gx, Gy and Gz correspond to three directions in space and are for specifying one rectangular parallelepiped in the interior of the tested subject. Referring to FIG. 3, three 90° pulses are applied. If three 90° pulses are applied as mentioned above, then, after the application of the third 90° pulse, an echo signal is generated for the same time as the time Te/2 ranging from the application of the first 90° pulse to the application of the second 90° pulse and after the time, Te+Tm, from the application of the first excitation pulse. This echo signal is called a stimulated echo and this stimulated echo is detected as an induced electromotive force by the radio-frequency coil 4 . The time Tm ranging from the application of the second 90° pulse and the application of the third 90° pulse is called the mixing time.
[0071] Every time three 90° pulses are applied, one of the gradient magnetic fields Gx, Gy and Gz in the three spatial directions is applied. In this way, slice selection is performed with respect to the three axes in space, and the stimulated echo signals obtained are those only from within the rectangular parallelepiped in which the slices in three directions intersect each other, and, from this sequence, a diffusion-weighted localized MR spectrum is obtained.
[0072] In FIG. 3 EC again designates the electric current applied through the tested subject. Referring to FIG. 3, the MPG pulses are applied to the gradient magnetic field Gx, with two pulses applied with the same magnitude but in opposite directions. The function of these MPG pulses is as described above. Again, if no diffusion is to be detected, no MPG pulse is applied.
[0073] In the present invention, in order to detect a diffusion developing isotropically, the b-factor of the MPG should be set to 0.02 to 2,000 s/mm 2 and preferably to 0.2 to 200 s/mm 2 . This is because, if the b-factor is small, the influence by the flow of ions or molecules can be contained. If the b-factor is large, then the burden in the manufacture and use of hardware such as the gradient magnetic field coil, etc. is increased.
[0074] The embodiment of the present invention will be further described, with reference to a few examples.
EXAMPLE 1
[0075] An acrylic column with a 26 mm inner diameter and 45 mm in length was filled with physiological saline solution. The column was placed as the phantom sample 5 in the magnetic field of an MRI machine of 1.5 T shown in FIG. 1. Further, the column was connected to the electric current source 6 through the lead wire 7 .
[0076] T1 values were measured by an inversion recovery (IR) sequence, applying an electric current to the phantom sample. Further, T 2 values were measured by a Carr-Purcell-Meiboom-Gill (CPMG) sequence. The measurement was made with respect to the whole solution in the column as the subject, applying a direct electric current via platinum planer electrodes of both ends of the column.
[0077] When the current density was 0.0 mA/cM 2 (in other words, when no current was applied), T1 and T2 were 2.8 and 2.1 seconds respectively. When the current density was 1.0 mA/cm 2 , T1 and T2 were 2.2 and 1.7 seconds respectively. When the current density was 2.0 mA/cm 2 , T1 and T2 were 1.8 and 1.5 seconds respectively.
[0078] In this case, the results obtained when the electric current was applied in parallel to the static magnetic field (i.e., the length direction of the column was set in parallel to the static magnetic field) and when the electric current was applied perpendicular to the static magnetic field (i.e., the length direction of the column was set perpendicular to the static magnetic field), and when the electric current was applied in a direction oblique to the static magnetic field, were the same. Thus, it has also been shown that the T1 shortening effect and the T2 shortening effect of the electric current in the present invention are isotropic.
EXAMPLE 2
[0079] The acrylic column with a 26 mm inner diameter and 45 mm in length was filled with physiological saline solution. This column was placed in the magnetic field of the MRI machine of 1.5 T, wherein the length direction of the column was set in parallel to the static magnetic field. An MRI image was obtained by the use of a T1-weighted spin echo imaging sequence with a repetition time Tr=300 and an echo time Te=25 ms, applying a direct electric current via platinum planer electrodes of both ends the column.
[0080] It was confirmed that the image of which the surface perpendicular to the static magnetic field was a section, the image of which the surface parallel to the static magnetic field was a section, and the image of which a surface oblique to the static magnetic field was a section were all markedly brighter than the images obtained under the same conditions without the application of an electric current, and, in the former, T1 was shortened and isotropically shortened.
[0081] Similar imaging experiments were conducted with a repetition time Tr=225 ms, applying an electric current. As a result, the signal intensities of the images obtained were comparable to the signal intensities of the images obtained with application of no electric current and with Tr=300 ms, whereby the imaging time as a whole was reduced by ¼ with the electric current.
EXAMPLE 3
[0082] Two aluminum plate electrodes of each 25 cm 2 were attached with conductive glue to both anterior and posterior sides of a human forearm, and the outer side thereof were wound with a cotton bandage. An MRI image was obtained by the use of a T1-weighted spin echo imaging sequence with a repetition time Tr=300 ms and an echo time Te=25 ms, applying a direct electric voltage of 8.0 V to the forearm via the electrodes.
[0083] It was confirmed that the muscle region where an electric current was allowed to flow through, produced signals brighter than the image obtained under the same condition without applying any electric current; and the T1 was shortened.
EXAMPLE 4
[0084] The acrylic column with a 26 mm inner diameter and 45 mm in length was filled with physiological saline solution. The column was placed as the phantom sample 5 in the magnetic field of the MRI machine of 1.5 T as shown in FIG. 1. The ADC was measured by a spin echo imaging sequence with a set of MPG pulses as shown in FIG. 2 , with Tr=5000 ms and Te=60 ms, applying a direct electric current via the platinum planer electrodes of both ends of the column. The MPG pulses were applied using a Gr gradient magnetic field as shown in FIG. 2, and the gradient factor attenuation value (b-factor) was set to 25 s/mm 2 .
[0085] When the current density was 0.0 mA/cm 2 (that is, when no current was applied), the ADC was 0.0021 mm 2 /s. When the current density was 0.2 mA/cm 2 , the ADC was 0.020 mm 2 /s. When the current density was 0.5 mA/cm 2 , the ADC was 0.079 mm 2 /s. In this case, the same result was obtained when the electric current was applied in parallel to the static magnetic field, when they were applied perpendicular to the static magnetic field, and when it was applied in a direction oblique to the static magnetic field. Thus, it was also proved that the ADC increasing effect according to the present invention was isotropic.
EXAMPLE 5
[0086] The acrylic column with a 26 mm inner diameter and 45 mm in length was filled with physiological saline solution. The column was placed in the magnetic field of the MRI machine of 1.5 T, wherein the length direction of the column was set in parallel to the static magnetic field. MRI images were obtained by a diffusion-weighted spin echo imaging sequence with MPG pulses and with Tr=5000 ms and Te=60 ms, applying a direct electric current of 0.2 mA/cm 2 via the platinum planer electrodes of both ends of the column. The gradient factor attenuation value of the MPG was set to 25 s/mm 2 .
[0087] The image of which the surface perpendicular to the static magnetic field was a section, the image of which the surface parallel to the static magnetic field was a section, and the image of which a surface oblique to the static magnetic field was a section, were all remarkably darker than the images obtained under the same conditions without application of an electric current; and thus it was confirmed that the ADC was remarkably increased and isotropically increased.
EXAMPLE 6
[0088] Two aluminum plate electrodes of each 25 cm were attached with conductive glue to both anterior and posterior sides of a human forearm, and the outer side thereof was wound with a cotton bandage. An MRI image was obtained by a diffusion-weighted spin echo imaging sequence with MPG pulses and with Tr=5000 ms and Te=60 ms, applying a direct electric voltage of 8.0 V to the forearm via the electrodes. The MPG gradient factor attenuation value of the MPG was set to 42 s/mm 2 .
[0089] It was confirmed that the muscle region where the electric current was allowed to flow through, produced signals markedly darker-intensity than the image obtained under the same conditions without applying an electric current; and the ADC was markedly increased.
EXAMPLE 7
[0090] A spherical glass phantom of 18 cm in inner diameter was filled with physiological saline solution. An electrical dipole of 4 cm in length, both ends of which were positive and negative electrodes, was installed in a submerged state at the center of the phantom. Lead-wires were led out from the center and twisted in the phantom so that electromagnetic effects of external currents were canceled. By applying electric voltage from outside, an electric current of 1 mA was made to flow through the spherical saline solution phantom directly from the electrical dipole. T1-weighted (Tr=300 ms, Te=25 ms), T2-weighted (Tr=5000 ms, Te=60 ms) and diffusion-weighted (Tr=5000 ms, Te=60 ms, and MPG Gradient Factor Attenuation b=25 s/mm 2 ) spin echo magnetic resonance images were obtained.
[0091] As a result, it was confirmed that, in case an electric voltage was applied to an electrical dipole, representing the distribution of an electric current around the electrical dipole, T1 and T2 reduction and diffusion increase were clearly exhibited, as compared with the case where no electric voltage was applied to the electrical dipole.
[0092] As mentioned above, according to the present invention, the T1 and T2 of a water-containing substance can be remarkably shortened without using a paramagnetic material or the like such as a gadolinium compound or the like. By shortening the T1, the measuring time of MRI or MRS can be shortened. Further, by the present invention, the ADC of a water-containing substance can be markedly increased.
[0093] Further, according to the present invention, the spatial distribution of the electrical properties of a water-containing substance can be measured. Further, according to the present invention, the spatial distribution of the electric currents in the interior of a water-containing substance can be measured. The above-mentioned measurements can all be performed in a non-invasion manner in case a living body is used as the tested subject.
[0094] Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contribution to the art. | In a method and apparatus for obtaining magnetic resonance data from water-containing substance, nuclear spins are excited in the substance in the presence of a homogenous static magnetic field, while an electrical current is flowing in the subject. The electrical current flowing in the subject shortens the spin-spin relaxation time and the spin-lattice relaxation time, and lengthens the apparent diffusion coefficient of the substance. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of prior Application Ser. No. 13/028,606, filed Feb. 16, 2011, currently pending;
[0000] Which was a divisional of Ser. No. 12/887,664, filed Sep. 22, 2010, now U.S. Pat. No. 7,913,135, granted Mar. 22, 2011;
Which was a divisional of prior application Ser. No. 12/403,791, filed Mar. 13, 2009, now U.S. Pat. No. 7,831,875, granted Nov. 9, 2010;
Which was a divisional of prior application Ser. No. 11/759,025, filed Jun. 6, 2007, now U.S. Pat. No. 7,525,305, granted Apr. 28, 2009;
Which was a divisional of prior application Ser. No. 11/096,399, filed Apr. 1, 2005, now U.S. Pat. No. 7,242,411, granted Jul. 10, 2007;
Which was a divisional of prior application Ser. No. 10/028,326, filed Dec. 21, 2001, now U.S. Pat. No. 6,877,122, granted Apr. 5, 2005;
which claims priority under 35 USC 119(e)(1) of Provisional Application No. 60/257,790, filed Dec. 22, 2000.
[0002] This patent is related to and incorporates by reference patent application Ser. No. 09/864,509 filed May 24, 2001, titled: 1149.1 Tap Linking Modules.
BACKGROUND OF THE DISCLOSURE
[0003] 1. Field of the Disclosure
[0004] This Disclosure relates generally to testing intellectual property (IP) cores via a test structure called a wrapper. The wrapper resides at the boundary of a core and provides a way to test the core and interconnections between the cores. Particularly, the Disclosure relates to a test architecture for accessing wrappers within an integrated circuit.
[0005] 2. Description of Related Art
[0006] FIG. 1 illustrates the test structure of a prior art wrapper 100 . The wrapper includes test interface signals 109 , an instruction register 105 , and set of data registers 106 - 108 . The instruction register is a register accessed by the test interface signals to load test instructions that control the operation of the wrapper, in particular the instructions control the selection of a data register and control the mode of operation of the selected data register. The selected data register may be accessed by the test interface to shift test data in and out of the wrapper. The set of data registers shown in FIG. 1 includes; (1) an internal scan register 108 for testing the core circuitry, (2) a boundary scan register 107 for controlling the inputs and outputs of the core during testing, and (3) a bypass register 106 for bypassing the wrapper via a single bit. Any number of additional user defined data registers may be included in the set of data registers of the wrapper, such as data registers supporting core emulation and programming operations as described in the referenced patent application Ser. No. 09/864,509.
[0007] The test interface 109 includes; (1) a clock signal for timing wrapper shift and test operations, (2) a shift signal for enabling data to be shifted through the wrapper from the serial input (SI) to the serial output (SO), (3) a capture signal for causing data to be captured into the instruction register or a selected data register, (4) an update signal for causing data to be output from the instruction register or a selected data register, (5) a reset signal for initializing the wrapper's instruction and data registers, and (6) a select signal for selecting data to be shifted through either the instruction register from SI to SO, or through a selected data register from SI to SO.
[0008] In the example of FIG. 1 , the test interface signals are simply gated, via AND gates (A), by the select signal to either allow them to be coupled to the instruction register or to the data registers. Other coupling methods may be used, but gating is used in this example. As can be seen, when select is high, gates 101 couple the test interface signals to the instruction register and the serial output of the instruction register is coupled to SO via multiplexer 103 . In this configuration, the instruction register may be shifted via SI and SO for instruction loading/unloading. When select is low, gates 102 couple the test interface signals to the data registers and the serial output of the selected data register, as determined by the instruction loaded in the instruction register, is coupled to SO via multiplexers 104 and 103 . In this configuration, the selected data register may be shifted via SI and SO for data loading/unloading.
[0009] As one skilled in the art of testing will see, the IEEE P1500 wrapper architecture is similar to the IEEE 1149.1 boundary scan architecture. The main difference between the P1500 wrapper architecture and 1149.1 boundary scan architecture is that the P1500 wrapper architecture accesses the instruction and data registers using discrete test interface signals 109 rather than accessing the instruction and data registers using the 1149.1's test access port (TAP) state machine interface. Thus P1500 wrappers are free of 1149.1 TAP interfaces.
[0010] FIG. 2 illustrates a core 201 equipped with the wrapper 100 of FIG. 1 . The test interface signals 109 of FIG. 2 are indicated as Control (CTL), and SI and SO are indicated as labeled in FIG. 1 . As the name implies the wrapper simply wraps around the core to provide a test access mechanism local to the core's input/output boundary. The instruction register 105 , bypass register 106 , and boundary register 107 are part of the wrapper. The internal scan register 108 is part of the core circuitry that may be accessed via the wrapper for testing the core.
[0011] FIG. 3 illustrates a prior art method of connecting three individual wrappers 307 - 309 of cores 1 - 3 onto a single scan chain arrangement 301 . The wrapper arrangement 301 will exist inside an IC. The serial inputs of the wrappers 307 - 309 are indicated as SI- 1 , SI- 2 , SI- 3 . The serial outputs of the wrappers 307 - 309 are indicated as SO- 1 , SO- 2 , and SO- 3 . The test interface signals 109 are bussed to the CTL- 1 , CTL- 2 , and CTL- 3 inputs of wrappers 307 - 309 . As seen in FIG. 3 , the arrangement 301 scan chain passes serially through the wrappers 307 - 309 from SI 302 to SO 303 . In this arrangement, all wrappers 307 - 309 can be controlled to load instructions via the SI 302 and SO 303 scan path, or all wrappers 307 - 309 can be controlled to load data via the SI 302 and SO 303 scan path. Access to the SI 302 , SO 303 , and test interface signals 109 of the arrangement 301 is typically provided to tester external of the IC.
[0012] FIG. 4 illustrates the wrapper design of FIG. 1 being modified to include an enable/disable capability. The modification includes adding an enable signal 402 and adding circuitry 401 (i.e. the OR (O) gate, AND (A) gate, and an inverter), responsive to the enable signal 402 to cause the wrapper to either be enabled to respond to the test interface 109 or be disabled from responding to the test interface 109 . In this example, a low on enable 402 will disable the wrapper from responding to the test interface 109 and a high on enable 402 will enable the wrapper to respond to the test interface 109 .
[0013] FIG. 5 illustrates an alternate method of enabling/disabling wrappers. In this example, it is assumed the wrapper design is fixed (hard) and cannot be modified, as could the wrapper design of FIG. 4 . With a fixed wrapper design, the enabling/disabling capability must be external of the wrapper. In FIG. 5 , gating circuitry 501 is inserted into the test interface 109 signal path to the wrapper and an enable signal 502 is added and connected to the gating circuitry to either enable the test interface signals 109 to be input to the wrapper or disable the test interface signals 109 from being input to the wrapper. In this example, a low on enable 502 will disable the wrapper from receiving the test interface signals and a high on enable 502 will enable the wrapper to receive the test interface signals. The use of wrapper enable signals, while not necessarily as shown in the examples of FIGS. 4 and 5 , is known.
[0014] The IEEE P1500 standard will define the connections to a wrapper test structure for an individual core of an IC. The standard leaves open the interconnection of the wrappers around multiple cores and the interconnection of wrappers around hierarchically arranged cores within cores.
SUMMARY OF THE DISCLOSURE
[0015] In accordance with the disclosure, the serial data paths into and out of the IC and into and out of the wrappers are selectively connected through input linking circuitry and output linking circuitry. The input linking circuitry and output linking circuitry provide for selective serial connection of any one, plural, or all of the wrappers on the IC between the serial data input and serial data output.
[0016] In a hierarchical arrangement of cores and their wrappers, the input and output linking circuitry provide for selective connection of the highest-level wrapper to be included in the selective serial connection. Additionally, the input and output linking circuitry provide for the selective connection of any one, plural or all of the lower level wrappers to be included in the serial connection.
[0017] The disclosed circuits provide for the selective connection of the wrappers through use of control signals output from link instruction registers. The link instruction registers produce these control output signals in response to instructions that are shifted into the link instruction registers. The link instruction registers also include a bypass path so they do not affect the shifting of test data through the serial connection of the wrappers.
[0018] In a hierarchical arrangement of wrappers on an IC, a single enable signal line may be available external of the IC for controlling the selective connection of the wrappers with a minimum number of control lines.
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1 illustrates a known core test wrapper.
[0020] FIG. 2 illustrates a core with a known wrapper.
[0021] FIG. 3 illustrates a serial connection of three known wrappers.
[0022] FIG. 4 illustrates a wrapper with an internal enable circuit.
[0023] FIG. 5 illustrates a wrapper with an external enable circuit.
[0024] FIG. 6A illustrates a test architecture according to the Disclosure
[0025] FIG. 6B illustrates input linking circuitry of the FIG. 6A test architecture.
[0026] FIG. 6C illustrates output linking circuitry of the FIG. 6A test architecture.
[0027] FIG. 7 illustrates wrapper arrangements for the FIG. 6A test architecture.
[0028] FIG. 8A illustrates the FIG. 6A test architecture coupled to a Link Instruction Register (LIR) according to the Disclosure.
[0029] FIG. 8B illustrates a 3-bit Instruction Register of the LIR.
[0030] FIG. 9 illustrates wrapper and LIR arrangements for the FIG. 8A test architecture.
[0031] FIG. 10 illustrates a wrapped core containing wrapped cores A and B.
[0032] FIG. 11 illustrates a test architecture for the wrappers of FIG. 10 .
[0033] FIG. 12 illustrates FIG. 10 wrapper arrangements.
[0034] FIG. 13 illustrates a test architecture embedded within another test architecture.
[0035] FIG. 14 illustrates the hierarchical access of FIG. 13 wrapper arrangements.
[0036] FIG. 15 illustrates a test architecture including a LIR according to the Disclosure.
[0037] FIG. 16 illustrates a test architecture containing the FIG. 15 test architecture.
[0038] FIG. 17 illustrates the hierarchical access of FIG. 16 wrapper arrangements.
[0039] FIG. 18 illustrates further embedding of test architectures according to the Disclosure.
[0040] FIG. 19 illustrates an alternate LIR circuit example.
[0041] FIG. 20 illustrates a serial connection of test architectures according to the Disclosure.
[0042] FIG. 21 illustrates a bypass arrangement for test architectures.
[0043] FIG. 22 illustrates example circuitry for enabling the FIG. 21 bypass arrangement.
[0044] FIG. 23 illustrates the use of data resynchronization circuits in the serial path between test architectures according to the Disclosure.
[0045] FIG. 24 illustrate an example circuit for the FIG. 23 data resynchronization circuits.
DETAILED DESCRIPTION
[0046] The circuits and processes disclosed in this patent are used in manufacturing to test and ensure proper operation of the integrated circuit products before sale. The circuits and processes disclosed in this patent can also be used after the sale of the integrated circuit products to test and ensure the continued proper operation of the integrated circuit products and possibly to develop and test software products associated with the integrated circuit products.
[0047] FIG. 6A illustrates a preferred test architecture 601 for accessing the wrappers 307 - 308 of FIG. 3 , according to the present Disclosure. In the test architecture 601 , wrappers 307 - 309 have been positioned between an input linking circuitry 602 block and an output linking circuitry 603 block, such that the wrapper serial inputs (SI- 1 , SI- 2 , SI- 3 ) are output from the input linking circuitry 602 and the wrapper serial outputs (SO- 1 , SO- 2 , SO- 3 ) are input to the output linking circuitry 603 . The wrapper serial outputs (SO- 1 , SO- 2 , SO- 3 ) are also input to the input linking circuitry 602 . The input linking circuitry 602 receives a serial input SI 604 and the output linking circuitry 603 outputs a serial output 605 . The control inputs (CTL- 1 , CTL- 2 , CTL- 3 ) of wrappers 307 - 309 are commonly connected to test interface CTL bus 109 . The input and output linking circuitry 602 and 603 receive control inputs from a wrapper Link bus 606 . The enable inputs (Enable- 1 , 2 , 3 ) of wrappers 307 - 309 are provided by an Enable bus 607 .
[0048] FIGS. 6B and 6C illustrate example implementations of input linking circuitry 602 and output linking circuitry 603 , respectively. Input linking circuitry 602 of FIG. 6B comprises multiplexers 608 - 610 which provide selectable connections between the serial inputs (SI- 1 , SI- 2 , SI- 3 ) of wrappers 307 - 309 and signals SI 604 , SO- 1 , SO- 2 , and SO- 3 . Multiplexers 608 - 610 receive linking control (SELSI- 1 , SELSI- 2 , SELSI- 3 ) inputs from Link bus 606 . The link control inputs 606 to multiplexer 610 enable the SI- 3 serial input to wrapper 309 to be connected to SI, SI- 1 , or SI- 2 . The link control inputs 606 to multiplexer 609 enable the SI- 2 serial input to wrapper 308 to be connected to SI, SI- 1 , or SI- 3 . The link control inputs 606 to multiplexer 608 enable the SI- 1 serial input to wrapper 307 to be connected to SI, SI- 2 , or SI- 3 . Output linking circuitry 603 of FIG. 6C comprises multiplexer 611 which, in response to link control inputs from Link bus 606 , allows connecting either the SO- 1 output of wrapper 307 , the SO- 2 output of wrapper 308 , or the SO- 3 output of wrappers 309 to SO 605 .
[0049] FIG. 7 illustrates the various wrapper arrangements 7001 - 7007 possible between the SI 604 and SO 605 of test architecture 601 . These wrapper arrangements are formed by inputting link controls to input and output circuitry 602 and 603 via Link bus 606 , and by inputting enable controls to wrappers 307 - 308 via Enable bus 607 . Arrangement 7001 contains only wrapper 307 between SI and SO. Arrangement 7002 contains wrappers 307 and 308 in series between SI and SO. Arrangement 7003 contains wrappers 307 and 309 in series between SI and SO. Arrangement 7004 contains wrappers 307 , 308 , and 309 in series between SI and SO. Arrangement 7005 contains wrapper 308 between SI and SO. Arrangement 7006 contains wrappers 308 and 309 in series between SI and SO. Arrangement 7007 contains wrapper 309 between SI and SO.
[0050] As can be seen in FIG. 7 , the test architecture 601 allows for the wrapper arrangement 301 of FIG. 3 as well as many different wrapper arrangements. The Link 606 and Enable 607 inputs to test architecture 601 may come from IC pads or from circuitry within the IC, such as an IEEE 1149.1 Test Access Port circuit. While IC pads or Test Access Port circuits may provide the Link and Enable inputs, a preferred method of providing the Link and Enable inputs to the test architecture 601 is described in detail below.
[0051] FIG. 8A illustrates circuitry for providing the Link 606 and Enable 607 control inputs to test architecture 601 , according to the present Disclosure. The circuitry includes a Link Instruction Register (LIR) 801 in series with the test architecture 601 . The LIR 801 has a serial input 802 connected to SO 605 of the test architecture 601 , a serial output (SO) 803 , control inputs connected to test interface control bus 109 , and control outputs 804 connected to the Link 606 and Enable 607 inputs of test architecture 601 . The LIR 801 consists of 3-bit instruction register (IR) 805 , a multiplexer 806 , and gating circuitry 807 .
[0052] During instruction scan operations, the select signal 808 of control bus 109 is high to enable the gating circuitry 807 to pass the control signals 109 to the 3-bit IR 805 and to connect the serial output of IR 805 to SO 803 via multiplexer 806 . In the instruction scan mode, the 3-bit IR 805 shifts instruction data when the test architecture shifts instruction data. Thus, during instruction scan operations, the 3-bit IR 805 becomes part of the instruction scan path between SI 604 and SO 803 .
[0053] During data scan operations, the select signal 808 of control bus 109 is low to disable the gating circuitry 807 from passing control signals 109 to the 3-bit IR 805 and to connect SO 605 of test architecture 601 to SO 803 via multiplexer 806 . In the data scan mode, the 3-bit IR 805 is disabled and the LIR simply forms a bypass connection between the SO 605 of test architecture 601 and the SO 803 of the LIR. Thus, during data scan operations, the LIR is included in the data scan path between SI 604 and SO 803 , but it does not add to the bit length of the data scan path. Also, since the control bus 109 is gated off during data scan operations, the data contained in the LIR's IR 805 cannot be changed during data scan operations.
[0054] It should be noted that while the LIR 801 has been shown inserted in the serial output path from the test architecture 601 (i.e. LIR input 802 connected to test architecture SO output 605 ), it could be have been similarly inserted in the serial input path to the test architecture 601 as well (i.e. LIR output 803 connected to test architecture SI input 604 ). Thus the position of the LIR 801 with respect to it being positioned at the beginning or ending of the serial path through the test architecture does not impact its ability to provide control of the Link 606 and Enable 607 bus inputs to the test architecture 601 .
[0055] FIG. 8B illustrates that the circuitry of the 3-bit IR 805 consists of a 3-bit shift register 810 , a 3-bit update register 811 , and decode logic 812 . During the shift step of an instruction scan operation, the 3-bit shift register 810 shifts data from its serial input to its serial output. During the update step of an instruction scan operation the data shifted into the 3-bit shift register 810 is transferred to the 3-bit update register 811 . The 3-bit update register outputs this data to decode logic 812 . The outputs of decode logic 812 respond to the data input from the 3-bit update register to output Link 606 and Enable 607 control signals to test architecture 601 via bus 804 . Reset signal 809 of control bus 109 is used to initialize shift register 810 and update register 811 , such that bus 804 may be set to a desired Link and Enable input state to test architecture 601 . While the examples of FIGS. 8A and 8B use a 3-bit IR, the IR could be of any bit length. The use of a 3-bit IR will be seen to be sufficient in selecting the wrapper arrangements described in regard to FIG. 9 below.
[0056] FIG. 9 illustrates the various wrapper arrangements 9001 - 9007 between SI 604 and SO 803 in response to different 3-bit codes scanned into LIR 801 . When the reset signal 809 is activated, the instruction registers 105 of wrappers 307 - 309 are initialized to a first instruction that selects the bypass registers 106 of the wrappers and enables normal operation of their associated cores. Also in response to the reset signal 809 , LIR 801 is initialized to contain all zeros, i.e. LIR=000.
[0057] As seen in arrangement 9001 , when the LIR contains a 000 code following a reset or an instruction scan operation it outputs Link 606 and Enable 607 control to enable and connect wrapper 307 in the scan path between SI 604 and SO 803 . The other wrappers 308 - 309 are disabled and disconnected from the scan path between SI 604 and SO 803 .
[0058] As seen in arrangement 9002 , when the LIR contains a 001 code following an instruction scan operation it outputs Link 606 and Enable 607 control to enable and connect wrappers 307 and 308 in the scan path between SI 604 and SO 803 . Wrapper 309 is disabled and disconnected from the scan path between SI 604 and SO 803 .
[0059] As seen in arrangement 9003 , when the LIR contains a 010 code following an instruction scan operation it outputs Link 606 and Enable 607 control to enable and connect wrappers 307 and 309 in the scan path between SI 604 and SO 803 . Wrapper 308 is disabled and disconnected from the scan path between SI 604 and SO 803 .
[0060] As seen in arrangement 9004 , when the LIR contains a 011 code following an instruction scan operation it outputs Link 606 and Enable 607 control to enable and connect wrappers 307 - 309 in the scan path between SI 604 and SO 803 .
[0061] As seen in arrangement 9005 , when the LIR contains a 100 code following an instruction scan operation it outputs Link 606 and Enable 607 control to enable and connect wrapper 308 in the scan path between SI 604 and SO 803 . The other wrappers 307 and 309 are disabled and disconnected from the scan path between SI 604 and SO 803 .
[0062] As seen in arrangement 9006 , when the LIR contains a 101 code following an instruction scan operation it outputs Link 606 and Enable 607 control to enable and connect wrappers 308 and 309 in the scan path between SI 604 and SO 803 . Wrapper 307 is disabled and disconnected from the scan path between SI 604 and SO 803 .
[0063] As seen in arrangement 9007 , when the LIR contains a 110 code following an instruction scan operation it outputs Link 606 and Enable 607 control to enable and connect wrapper 309 in the scan path between SI 604 and SO 803 . The other wrappers 307 and 308 are disabled and disconnected from the scan path between SI 604 and SO 803 .
[0064] In all arrangements 9001 - 9007 , instruction scan operations shift data through the 3-bit IR 805 of LIR 801 , but data scan operations do not shift data through the 3-bit IR 805 of LIR 801 , as previously described. A current arrangement 9001 - 9007 will be maintained following an instruction scan operation as long as the 3-bit LIR code is not changed by the instruction scan operation.
[0065] Some advantages of using the LIR 801 to control the Link 606 and Enable 607 inputs to the test architecture 601 are listed below.
[0066] The LIR 801 exists and operates within the scan path of each selected wrapper arrangement 9001 - 9007 . Therefore no additional circuitry and/or interfaces (for example no 1149.1 Test Access Port and/or IC interface pads as mentioned in regard to FIG. 7 ) are required to control the Link 606 and Enable 607 buses to switch between wrapper arrangements.
[0067] The LIR 801 provides the opportunity of switching between wrapper arrangements 9001 - 9007 following each instruction scan operation. Thus the shifting in and updating of LIR wrapper arrangement codes and wrapper test instructions may be performed during the same instruction scan operation.
[0068] The LIR 801 does not add bits to a selected wrapper arrangement 9001 - 9007 during data scan operations. By not adding to the bit length of a given wrapper arrangement, the test patterns applied to the wrapper arrangement do not have to be modified to accommodate the presence of the LIR. For example, if a test pattern set existed for testing core 1 using the internal scan register 108 ( FIG. 1 ) of wrapper 307 , arrangement 9001 could be selected via an instruction scan operation then the test patterns could be applied using data scan operations. Since the LIR does not add bits to the length of arrangement 9001 during data scan operations, the core 1 test pattern set can be applied without modification, enabling core 1 test pattern reuse
[0069] FIG. 10 illustrates an example of a core 4 1001 which has a wrapper 1002 . Core 4 differs from the previously described cores 1 - 3 in that it contains an embedded core A 1003 having a wrapper 1004 and an embedded core B 1005 having a wrapper 1006 . Access to wrapper 1002 is provided via SI- 4 , SO- 4 , CTL- 4 , and Enable- 4 . Access to wrapper 1004 is provided via SI-A, SO-A, CTL-A, and Enable-A. Access to wrapper 1006 is provided via SI-B, SO-B, CTL-B, and Enable-B.
[0070] FIG. 11 illustrates the test architecture 1101 of the present Disclosure being used to provide access to wrappers 1002 , 1004 , and 1006 of core 4 . The test architecture is similar to the test architecture 601 described in regard to FIG. 6 with the exceptions that; (1) wrapper 1002 has been substituted for wrapper 307 , (2) wrapper 1004 has been substituted for wrapper 308 , (3) and wrapper 1006 has been substituted for wrapper 309 .
[0071] FIG. 12 illustrates the wrapper arrangements 1201 - 1207 selectable via the Link 606 and Enable 607 buses of test architecture 1101 . The wrapper arrangements 1201 - 1207 are the same as wrapper arrangements 7001 - 7007 of FIG. 7 with the exceptions that; (1) wrapper 1002 has been substituted for wrapper 307 , (2) wrapper 1004 has been substituted for wrapper 308 , (3) and wrapper 1006 has been substituted for wrapper 309 .
[0072] FIG. 13 illustrate a test architecture 1301 of the present Disclosure which contains wrapper 307 , wrapper 308 , and the test architecture 1101 of FIG. 11 . Test architecture 1301 is similar to the test architecture 601 of FIG. 6 with the exception that test architecture 1101 has been substituted for the core 3 wrapper 309 . Test architecture 1301 is serially connected to an N-bit LIR 1302 which provides control input via bus 1303 to the Link 606 and Enable 607 buses of test architecture 1301 and to the Link and Enable buses 1306 of test architecture 1101 , as described previously in regard to the 3-bit LIR 810 of FIG. 8A . The N-bit LIR 1302 is similar to the 3-bit LIR 810 except that its IR contains addition bits for decoding the additional Link and Enable- 4 , A, B signals 1306 required by test architecture 1101 .
[0073] Embedding test architecture 1101 within test architecture 1301 requires that the Link and Enable- 4 , A, B signals 1306 of test architecture 1101 be brought out of test architecture 1301 so they can be controlled by the N-bit LIR via bus 1303 . Thus the N-bit LIR not only provides the Link 606 and Enable 607 signals for test architecture 1301 , but also the Link 606 and Enable signals 1306 for the embedded test architecture 1101 .
[0074] FIG. 14 illustrates in 1410 the N-bit LIR 1302 controlled arrangements 1401 - 1407 of test architecture 1301 . As can be seen in 1410 , the N-bit LIR can be loaded with codes to select; (1) wrapper 307 between SI 1304 and SO 1305 (arrangement 1401 ), (2) wrappers 307 and 308 between SI and SO (arrangement 1402 ), (3) wrapper 307 and test architecture 1101 between SI and SO (arrangement 1403 ), (4) wrappers 307 , 308 , and test architecture 1101 between SI and SO (arrangement 1404 ), (5) wrapper 308 between SI and SO (arrangement 1405 ), (6) wrapper 308 and test architecture 1101 between SI and SO (arrangement 1406 ), and (7) test architecture 1101 between SI and SO (arrangement 1407 ).
[0075] FIG. 14 further illustrates in 1420 that when test architecture 1101 is included in a test architecture 1301 arrangement between SI 1304 and SO 1305 , the N-bit LIR provides control for selecting the particular arrangement between the 1101 test architectures SI 1102 and SO 1103 . As can be seen in 1420 , the N-bit LIR can be loaded with codes to select; (1) wrapper 1002 between SI 1102 and SO 1103 (arrangement 1201 ), (2) wrappers 1002 and 1004 between SI and SO (arrangement 1202 ), (3) wrapper 1002 and 1006 between SI and SO (arrangement 1203 ), (4) wrappers 1002 , 1004 , and 1006 between SI and SO (arrangement 1204 ), (5) wrapper 1004 between SI and SO (arrangement 1205 ), (6) wrapper 1004 and 1006 between SI and SO (arrangement 1206 ), and (7) wrapper 1006 between SI and SO (arrangement 1207 ).
[0076] FIGS. 10-14 have illustrated how one test architecture 1101 of the present Disclosure may be embedded within another test architecture 1301 of the present Disclosure and both test architectures accessed using a single LIR. For simplification, only one test architecture 1101 was illustrated as being embedded in test architecture 1301 . However, it should be understood that a plurality of test architectures 1101 can be embedded in test architecture 1301 . For example, substituting a second test architecture 1101 for wrapper 308 and a third test architecture 1101 for wrapper 307 in FIG. 13 would illustrate the embedding of three 1101 test architectures within test architecture 1301 .
[0077] While only a single level of test architecture embedding was shown, i.e. test architecture 1101 embedded within test architecture 1301 , it is clear that the multiple levels of test architecture embedding is possible using the present Disclosure. When multiple levels of test architecture embedding is performed, the number of control signals that must be output from the LIR increases, as can be understood from the inspection of bus 1303 of FIG. 13 . At some point the number of LIR output control signals may reach a level that is unacceptable due to wire routing concerns within an IC. The following describes an alternate embodiment of the present Disclosure that provides a solution to this LIR output control signal wire routing problem.
[0078] FIG. 15 illustrates an alternate preferred test architecture 1501 according to the present Disclosure that combines the core 4 test architecture 1101 of FIG. 11 with a LIR 1502 . LIR 1502 is similar to LIR 801 of FIG. 8A with the exception that gating circuitry 1503 replaces gating circuitry 807 . Gating circuitry 1503 provides, in addition to the select signal from control bus 109 , an additional input for a test architecture enable (TAENA) signal 1504 . The TAENA signal 1504 is similar to the select signal 808 in that it operates to; (1) enable gating circuitry 1503 to pass control bus signals 109 to the 3-bit IR during instruction scan operations, or (2) disable gating circuitry 1503 from passing control bus signals 109 to the 3-bit IR during instruction scan operations. Thus the only time the 3-bit IR receives control bus 109 signals is when TAENA 1504 and select 808 are both set to enable gating circuitry 1503 to pass control bus 109 signals to the 3-bit IR.
[0079] FIG. 16 illustrates a test architecture 1601 of the present Disclosure which contains wrapper 307 , wrapper 308 , and the test architecture 1501 of FIG. 15 . Test architecture 1601 is similar to the test architecture 1301 of FIG. 13 with the exception that test architecture 1501 has been substituted for test architecture 1101 . Test architecture 1601 is serially connected to an N-bit LIR 1602 which provides control input via bus 1603 to the Link 606 and Enable 607 buses of test architecture 1601 and the TAENA signal 1504 to test architecture 1501 . The N-bit LIR 1602 is similar to the N-bit LIR 1302 except that it contains a reduced number of bits and control signal outputs, since it does not need to decode all the Link and Enable- 4 , A, B signals that were required by the embedded test architecture 1101 of test architecture 1301 . Embedding test architecture 1501 within test architecture 1601 only requires that the TAENA signal 1504 be brought out of test architecture 1601 so it can be controlled by the N-bit LIR via bus 1603 .
[0080] FIG. 17 illustrates in 1710 the N-bit LIR 1602 controlled arrangements 1701 - 1707 of test architecture 1601 . As can be seen in 1710 , the N-bit LIR can be loaded with codes to select; (1) wrapper 307 between SI 1612 and SO 1613 (arrangement 1701 ), (2) wrappers 307 and 308 between SI and SO (arrangement 1702 ), (3) wrapper 307 and test architecture 1501 between SI and SO (arrangement 1703 ), (4) wrappers 307 , 308 , and test architecture 1501 between SI and SO (arrangement 1704 ), (5) wrapper 308 between SI and SO (arrangement 1705 ), (6) wrapper 308 and test architecture 1501 between SI and SO (arrangement 1706 ), and (7) test architecture 1501 between SI and SO (arrangement 1707 ).
[0081] FIG. 17 further illustrates in 1720 that when test architecture 1501 is included in a test architecture 1601 arrangement between SI 1612 and SO 1613 by appropriate setting of the TAENA signal 1504 , the 3-bit LIR 1502 of test architecture 1501 is included in the arrangement and made accessible during instruction scan operations. The 3-bit LIR of test architecture 1501 can be scanned to select any particular arrangement between the 1501 test architectures SI 1505 and SO 1506 . As can be seen in 1720 , the 3-bit LIR 1502 can be loaded with codes to select; (1) wrapper 1002 between SI 1505 and SO 1506 (arrangement 1501 ), (2) wrappers 1002 and 1004 between SI and SO (arrangement 1502 ), (3) wrapper 1002 and 1006 between SI and SO (arrangement 1503 ), (4) wrappers 1002 , 1004 , and 1006 between SI and SO (arrangement 1504 ), (5) wrapper 1004 between SI and SO (arrangement 1505 ), (6) wrappers 1004 and 1006 between SI and SO (arrangement 1506 ), and (7) wrapper 1006 between SI and SO (arrangement 1507 ).
[0082] It should be clear from FIG. 17 that when test architecture 1501 is included in an arrangement 1710 of test architecture 1601 , two LIRs will be scanned in series during instructions scan operations, LIR 1602 and LIR 1502 . Also it should be clear that since LIR 1502 provides within the test architecture 1501 all the control signals required to select the test architecture 1501 arrangements 1720 , via bus 804 of FIG. 15 , the wire routing problem mentioned in regard to FIG. 13 is significantly reduced. The only control signal LIR 1602 needs to provide to include test architecture 1501 in an arrangement 1710 is the TAENA signal 1504 . Once included, the LIR 1502 of test architecture 1501 becomes enabled and can be scanned to provide all the additional signals required for selecting arrangements 1720 within test architecture 1501 .
[0083] The advantage test architecture 1501 has over test architecture 1101 is that when test architectures 1501 is embedded within another test architecture 1601 , only the TAENA 1504 signal of test architecture 1501 is required to be brought out of the other test architecture 1601 to be accessed by a LIR 1602 connected to the other test architecture 1601 . This can be compared to test architecture 1301 of FIG. 13 where it was required to bring out the Link & Enable- 4 , A, B signals of test architecture 1101 to be connected to LIR 1302 . As described earlier in regard to test architecture 1101 and 1301 of FIG. 13 , multiple test architectures 1501 could have been shown embedded within test architecture 1610 , by simply substituting a second and third test architecture 1501 for wrappers 308 and 307 respectively.
[0084] The process of making the TAENA signal of an embedded test architecture, like 1501 , externally available at the I/O boundary of a next higher level test architecture, like 1601 , forms the basis of a framework that can be used to access any hierarchically positioned test architecture within an IC. The following provides an example of this hierarchical test architecture access framework and the process for selecting embedded test architectures contained therein.
[0085] FIG. 18 illustrates a test architecture 1801 containing wrapper 307 , wrapper 308 , and the test architecture 1610 of FIG. 16 . Test architecture 1610 is similar to test architecture 1501 in that it combines a LIR 1602 with test architecture 1601 , as test architecture 1501 combined the LIR 1502 with test architecture 1101 . Test architecture 1610 has a TAENA signal 1611 , as test architecture 1501 has a TAENA signal 1504 . Test architecture 1610 is associated with a core 5 , as test architecture 1501 is associated with a core 4 . The LIR 1802 is connected to the TAENA 1611 signal of test architecture 1601 via bus 1803 , as LIR 1602 is connected to TAENA 1504 signal of test architecture 1601 via bus 1603 .
[0086] The process steps of accessing test architecture 1101 embedded within test architecture 1501 , which is further embedded within test architecture 1610 , which is still further embedded within test architecture 1810 , is as follows. The process steps below are assumed to start at a point where only wrapper 307 and LIR 1802 of FIG. 18 are in the serial path between SI 1812 and SO 1813 of FIG. 18 , similar to arrangement 9001 shown in FIG. 9 .
[0087] Step 1 Perform a first instruction scan operation to load LIR 1802 with a code that sets TAENA 1611 , via bus 1803 , to a state that enables test architecture 1610 . Following this instruction scan operation, test architecture 1610 and LIR 1802 are in the serial path between SI 1812 and SO 1813 .
[0088] Step 2 Perform a second instruction scan operation to load LIR 1802 with a code that maintains TAENA 1611 at a state enabling test architecture 1610 , and to load LIR 1602 of test architecture 1610 with a code that sets TAENA 1504 to a state that enables test architecture 1501 . Following this instruction scan operation, test architecture 1501 , LIR 1602 , and LIR 1802 are in the serial path between SI 1812 and SO 1813 .
[0089] Step 3 Perform a third instruction scan operation to load LIR 1802 and LIR 1602 with codes that maintain TAENA 1611 and TAENA 1504 at states enabling test architectures 1610 and 1501 , and to load LIR 1502 of test architecture 1501 with a code that selects a desired arrangement 1201 - 1207 of test architecture 1101 . Following this instruction scan operation, the selected arrangement 1201 - 1207 of test architecture 1101 , LIR 1502 , LIR 1602 , and LIR 1802 are in the serial path between SI 1812 and SO 1813 .
[0090] Step 4 Perform subsequent instruction and/or data scan operations to the selected arrangement 1201 - 1207 of test architecture 1101 as required to perform a desired test or other operation via the SI 1812 and SO 1813 terminals of the test architecture 1810 of FIG. 18 . During subsequent instruction scan operations, the codes loaded into LIRs 1502 , 1602 , and 1802 should maintain access to the currently selected arrangement of test architecture 1101 , unless a new arrangement is needed. Since, as previously mentioned in regard to FIG. 8A , data scan operations cannot change existing LIR codes, the access to test architecture 1101 , setup by Steps 1-3 above, is not effected during subsequent data scan operations.
[0091] At some point in accessing embedded test architectures using data scan operations, the accumulation of the LIR bypass paths, i.e. the direct connection path coupling the LIR input 802 to the LIR output 803 via multiplexer 806 of FIG. 8A , may become to long for data to propagate at a desired data scan clock rate. In some cases therefore, it may be necessary to add a resynchronization flip-flop in the serial path between test architectures, such that during data scan operations the data may be re-timed as it passes between serially connected test architectures. A logical point to insert such a resynchronization flip-flop would be in the LIR bypass path described above. Placing it elsewhere would force instruction scan operations to unnecessarily have to pass through the resynchronization flip-flop.
[0092] FIG. 19 illustrates an LIR 1901 containing a resynchronization register/flip-flop 1904 in the bypass path of the LIR. LIR 1901 is simply LIR 801 adapted to include flip-flop 1904 in the bypass path between LIR input 802 and LIR output 803 and circuitry 1902 and 1903 to enable the flip flop 1904 to receive control bus 109 input during data scan operations. During data scan operations the select signal will be low to select the registered bypass path through multiplexer 806 to SO 803 . Inverter 1902 inverts the select signal so that during data scan operations And gating circuit 1903 passes bus 109 to flip flop 1904 . In response to the clock signal of bus 109 , flip-flop 1904 moves data from SI 802 to 50803 . Use of LIR 1901 with a registered bypass path between input 802 and output 803 eliminates the above-described concern of using LIRs with direct connection bypass paths between input 802 and output 803 .
[0093] FIG. 20 illustrates a serial configuration 2001 of test architectures 2006 - 2008 . The test architectures 2006 - 2008 are connected in a serial path between SI 2004 and SO 2005 . The serial path includes a LIR 2002 that provides the link and enable control bus 2003 to the test architectures. Each test architecture and the LIR receive control input from control bus 109 . A TAENA 2009 signal is shown being input to the LIR 2002 to indicate that the serial configuration 2001 of test architectures 2007 - 2008 may itself be a test architecture according to the present Disclosure, being enabled and disabled by TAENA 2009 as previously described in regard to FIGS. 15 , 16 , and 18 . If serial configuration 2001 is viewed as a test architecture 2001 , it could be embedded within another test architecture as test architectures 1501 and 1610 were embedded within other test architectures 1610 and 1810 , respectively. The following description assumes the serial configuration (or test architecture) 2001 is enabled by TAENA 2009 .
[0094] During instruction or data scan operations data flows through the selected arrangement of each test architecture 2006 - 2008 and through the LIR from SI 2004 to SO 2005 . If testing or other operation, such as emulation, is to be performed on only one of the test architectures, say on test architecture 2007 , the selected arrangements of other test architectures 2006 and 2008 must be serially traversed during the application of the test or other operation. The following description illustrates a modification to the test architectures 2006 - 2008 that prevents having to traverse arrangements within test architectures that are not involved in a test or other operation. This modification will be described as it would be applied if test architectures 2006 - 2008 are of the type 601 shown in FIG. 6A . To illustrate that test architectures 2006 - 2008 are of type 601 , the SIs and SOs of test architectures 2006 - 2008 are each labeled as SI 604 and SO 605 .
[0095] In FIG. 21 , a group of arrangements 2101 - 2108 for the modified test architectures 601 are shown. In comparing the group of arrangements of FIG. 21 to that of FIG. 7 , it is seen that arrangements 2101 - 2107 of FIG. 21 are identical to the arrangements 7001 - 7007 of FIG. 7 . The difference between the FIGS. 7 and 21 arrangements is that a new wrapper bypass arrangement 2108 has been added in the arrangements of FIG. 21 . This new wrapper bypass arrangement 2108 provides for directly connecting the SI 604 input and SO 605 output of modified test architectures 601 , such that all wrappers 307 - 309 contained within the modified test architectures 601 may be disabled and disconnected (bypassed) from the serial path between SO 604 and SO 605 .
[0096] FIG. 22 illustrates how the output linking circuitry 603 of FIG. 6C is modified to allow for the new wrapper bypass arrangement 2108 . The modification involves replacing the three input multiplexer 611 of FIG. 6C with the four input multiplexer 2201 of FIG. 22 and connecting the SI 604 input of test architecture 601 to the fourth input of multiplexer 2201 . In addition to this modification of the output linking circuitry 603 , bypass codes for each of the test architectures 2006 - 2008 need to be added to the LIR 2002 to enable selecting the wrapper bypass arrangement 2108 of FIG. 21 in each of the test architectures 2006 - 2008 . The following description of a bypass code for test architecture 2006 is given.
[0097] When the LIR 2002 contains a bypass code for test architecture 2006 , it will output control on bus 2003 to input SELSO 2202 control to multiplexer 2201 to form the wrapper bypass arrangement 2108 between the SI 604 input and SO 605 output of test architecture 2006 . Also when LIR 2002 contains the bypass code it will disable the wrappers 307 - 309 of test architecture 2006 from responding to control bus 109 by setting their Enable- 1 , 2 , 3 inputs low via bus 2003 . While test architecture 2006 is controlled to the wrapper bypass arrangement 2108 , data passes directly from its SI 604 input to SO 605 output during instruction and data scan operations occurring in the serial test architecture configuration 2001 of FIG. 20 .
[0098] If test architectures 2006 and 2008 are controlled to the above described wrapper bypass arrangement 2108 of FIG. 21 while test architecture 2007 is controlled to say the 2105 arrangement of FIG. 21 , i.e. core 2 wrapper 308 is selected, then testing or other operations can occur on the wrapper of core 2 in test architecture 2007 without having to traverse wrapper arrangements in the leading 2006 and trailing 2008 test architectures of FIG. 20 . Thus more efficient serial access is provided to the wrapper of core 2 of test architecture 2007 using the wrapper bypass arrangements 2108 in test architectures 2006 and 2008 . This increase in serial access efficiency would be even more pronounced if the example of FIG. 20 had shown a multiplicity of serially connected test architectures preceding and following the target test architecture 2007 .
[0099] While the modification to include a wrapper bypass arrangement 2108 has been described as it would apply to the type 601 test architecture of FIG. 6A , it is a general modification that can be applied to any of the test architectures described herein. For example, test architecture 1301 of FIG. 13 , test architecture 1501 of FIG. 15 , test architecture 1610 of FIG. 16 , and test architecture 1810 of FIG. 18 could all be modified to include the wrapper bypass arrangement described above.
[0100] In test architectures that contain an embedded LIR, i.e. test architectures 1501 , 1610 , and 1810 , the embedded LIR would include the above described wrapper bypass codes required to select the wrapper bypass arrangement 2108 of the test architecture. Including the wrapper bypass arrangement in all the above-mentioned test architectures would serve to improve the serial access efficiency when the test architectures are placed into a serial configuration 2001 as shown in FIG. 20 .
[0101] In test architectures that contain an embedded LIR (i.e. 1501 , 1610 , 1810 ), it is preferable to use the LIR 1901 of FIG. 19 as opposed to LIR 801 of FIG. 8A , since LIR 1901 allows registering the data transfers during data scan operations. By registering data scan operation transfers, any number of serially connected test architectures may be placed in the wrapper bypass arrangement 2108 and operated without having to reduce the data scan clock frequency, as described in regard to FIG. 19 . In test architectures that do not contain an embedded LIR (i.e. 601 ), it may be necessary to insert a data resynchronization circuit (DRC) at points along the serial path connecting multiple test architectures to maintain a desired scan clock rate through the serial path when multiple test architectures are placed in the wrapper bypass arrangement 2108 .
[0102] For example, FIG. 23 illustrates the serial connection 2301 of the multiple test architectures 2006 - 2008 of FIG. 20 being connected together serially through DRC's 2302 - 2304 . TAENA 2313 is shown simply to indicate that serial configuration 2301 , like serial configuration 2001 , may be viewed as an embedded test architecture. As seen in FIG. 23 , DRC 2302 exists between SO 605 of test architecture 2006 and the SI 604 of test architecture 2007 , DRC 2303 exists between SO 605 of test architecture 2007 and SI 604 of test architecture 2008 , and DRC 2304 exists between SO 605 of test architecture 2008 and the SI 802 of LIR 2305 . The DRCs 2302 - 2304 are connected to the clock 2306 signal of control bus 109 , to allow them to operate during both instruction and data scan operations. The DRCs 2302 - 2304 are also connected to bypass select signals 2307 - 2309 , respectively, from LIR output control bus 2312 . The bypass select signals are signals added to the LIR output control bus 2312 when DRCs are used. There is one unique bypass select signal 2307 - 2308 for each DRC 2302 - 2304 to allow separate control of each DRC.
[0103] FIG. 24 illustrates an example DRC circuit. The DRC contains a flip-flop (FF) 2403 and a multiplexer 2402 . The DRC has a SI 2404 that is input to the multiplexer and FF. The output of the FF is input to the multiplexer. The multiplexer has a control input 2407 and a SO 2405 . The FF has a clock input 2406 . The control inputs 2407 of DRC 2302 - 2304 of FIG. 24 are connected to the bypass select signals 2307 - 2309 respectively. The clock inputs 2406 of DRCs 2302 - 2304 of FIG. 24 are connected to control bus 109 clock signal 2306 . The SIs 2404 of DRCs 2302 - 2304 of FIG. 24 are connected to the SOs 605 of test architectures 2006 - 2007 respectively. The SOs 2405 of DRCs 2302 - 2304 of FIG. 24 are connected to the SI 604 of test architecture 2007 , the SI 604 of test architecture 2008 , and SI 802 of LIR 2305 respectively.
[0104] If LIR 2305 is loaded with a bypass code for test architecture 2006 , the bypass select signal 2307 will be set cause DRC 2302 to place FF 2406 between the SO output of test architecture 2006 and SI input of test architecture 2007 . For all other codes, bypass select will be set to cause DRC 2302 to directly connect the SO output of test architecture 2006 to the SI input of test architecture 2007 via multiplexer 2402 .
[0105] If LIR 2305 is loaded with a bypass code for test architecture 2007 , the bypass select signal 2308 will be set cause DRC 2303 to place a FF 2406 between the SO output of test architecture 2007 and SI input of test architecture 2008 . For all other codes, bypass select will be set to cause DRC 2303 to directly connect the SO output of test architecture 2007 to the SI input of test architecture 2008 via multiplexer 2402 .
[0106] If LIR 2305 is loaded with a bypass code for test architecture 2008 , the bypass select signal 2309 will be set cause DRC 2304 to place a FF 2406 between the SO output of test architecture 2008 and SI input of LIR 2305 . For all other codes, bypass select will be set to cause DRC 2304 to directly connect the SO output of test architecture 2008 to the SI input of LIR 2305 via multiplexer 2402 .
[0107] As can be seen from the above description of FIGS. 23 and 24 , when a test architecture is placed in the wrapper bypass arrangement, the DRC associated with the SO output of the test architecture is set to insert FF 2406 between its SI 2404 and SO 2405 . During instruction and data scan operations, this inserted FF 2406 registers the data output from the test architecture in the wrapper bypass arrangement to the SI input of the next serially connected test architecture.
[0108] Also as can be seen from the above description of FIGS. 23 and 24 , when a test architecture is not placed in the wrapper bypass arrangement, the DRC associated with the SO output of the test architecture is set to form a direct path between its SI 2404 and SO 2405 . During instruction and data scan operations, this direct path simply passes the data from the SO output of the leading test architecture to the SI input of the trailing test architecture. Directly connecting the SO output of a test architecture not in the wrapper bypass arrangement is fine since all other selectable arrangement will include registration in the form of one of the data registers 106 - 108 described in regard to FIG. 1 .
[0109] While insertion of DRC FFs 2406 and/or LIR FFs 1904 in the serial path of series connected test architectures, such as FIG. 23 , takes away from the test pattern reuse advantage 3 stated earlier in regard to FIGS. 8 and 9 , it offers the advantage of being able to operate serially connected test architectures at high clock frequencies. Thus while test patterns may need to be modified when FF 2406 / 1904 bit positions are inserted in the path between serially connected test architectures, the inserted bit positions facilitate high speed clocking of the data through serially connected test architectures.
[0110] While DRCs in FIGS. 23 and 24 have been described as they would be used to register or pass serial test/emulation data between test architecture circuits 2007 - 2008 , it should be understood that the DRCs could also be used to register or pass functional data between functional circuits as well. For example, circuits 2006 - 2007 could represent functional circuits in an IC or on a board, such as microprocessors, digital signal processors, memories, mixed signal circuits (A/D, D/A), or any other type of circuits that are connectable via their inputs and outputs to communicate data. Using DRCs, the data communicated between functional circuits could selectively be communicated in either a registered or non-registered form, as described above in regard to FIGS. 23 and 24 .
[0111] Although the present Disclosure has been described in accordance to the embodiments shown in the figures, one of ordinary skill in the art will recognize there could be variations to these embodiments and those variations should be within the spirit and scope of the present Disclosure. Accordingly, modifications may be made by one ordinarily skilled in the art without departing from the spirit and scope of the appended claims. | A test architecture accesses IP core test wrappers within an IC using a Link Instruction Register (LIR). An IEEE P1500 standard is in development for providing test access to these individual cores via a test structure called a wrapper. The wrapper resides at the boundary of the core and provides a way to test the core and the interconnections between cores. The test architecture enables each of the plural wrappers in the IC, including wrappers in cores embedded within other cores, with separate enable signals. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
Not applicable.
INCORPORATION-BY-REFERENCE OF MATERIALS SUBMITTED ON A COMPACT DISC
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a progressive damping device for furniture, which is designed to prevent impacts between the mobile parts of furniture provided with self-closing systems, and provides progressive closure according to the speed and energy acquired in the closure, whilst complying with a general composition comprising a cylinder in which a dynamic fluid circulates, and in the interior of which there is displaced a piston which has a rod provided with an elastoplastic valve, which delimits respective compression and expansion chambers.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
In this field there are known devices provided with dampers for furniture with a self-closing system, for the purpose of preventing impact between the mobile part of the furniture, such as a drawer, and the fixed part. Amongst these devices, reference can be made to Spanish patent P-200400369 “Damping device for furniture” by the same inventor, which describes a damper based on a fluid-dynamic cylinder in which the cylindrical body is provided with a piston which is displaced in relation to the cylindrical body. The said piston has a cylindrical form and is modified by two faces which are opposite one another, and the dimensions of which decrease to form a coaxial extension. However, this damping mechanism does not provide progressive damping based on speed.
In order to prevent problems of impact of the furniture during closure by obtaining progressive damping, a number of devices have been developed, most of which are highly complex, thus adding to their production costs and making assembly difficult. In order to solve this problem, the same applicant submitted the additional Spanish patent P-200500139, in which graduation of the damping action was achieved according to the speed of the impulse to be damped. For this purpose, this damping device comprises an inner cylindrical sleeve which is prolonged by means of a strip of an elastoplastic nature, and extends diametrically in the form of a bridge which projects beyond the point of the extension of the piston in the form of a basket. This basket will permit graduation in the damping of the closure of the furniture by means of its resilient flexure, but the part which is provided with the basket is produced by injection, and the point of injection coincides with the strip of the basket. This means that it is difficult to predict the exact modulus of flexure, including the origin of possible points of occurrence of rupture cracks.
These problems are exacerbated by the dimensions of the parts with a greatly reduced size. In addition, this basket forms together with the extension of the piston an end in the form of a crosspiece, which is interposed in the fluid discharge flow.
BRIEF SUMMARY OF THE INVENTION
In view of this situation, the present invention proposes a device for damping progressively according to speed, which comprises a cylinder body in which a dynamic fluid circulates, and the interior of which comprises a piston with a rod which extends from the cylinder body, and delimits two chambers, one for compression in the damping, and the other for expansion, which, depending on the position of the piston, have a variable volume.
The piston is a cylindrical sleeve which contains in its interior a displaceable elastoplastic valve, which is provided with symmetrical resilient fins with a total radial dimension which is greater than the inner diameter of the interior annular projection of the cylindrical sleeve. The longitudinal position of these resilient fins when not flexed being such that their distance to the wall which closes the head of the elastoplastic valve is greater than the distance between the active side of the interior annular projection and the seating wall of the cylindrical sleeve, with these resilient fins reaching the active side of the interior annular projection before the wall which closes the head of the elastoplastic valve abuts the seating wall of the cylindrical sleeve.
The resilient fins of the elastoplastic valve are equidistant, there are preferably two of them, and their radial length is larger than the smaller inner diameter of the interior annular projection of the cylindrical sleeve, including in the state of flexure of the resilient fins.
The cylindrical sleeve has its interior annular projection with its respective sides equidistant from the seating walls of the cylindrical sleeve, thus facilitating its reversible assembly.
The point of support of the resilient fins on the interior annular projection of the cylindrical sleeve will be derived from the impact provided in the movement in the direction of damping, on the active side of the annular projection.
As far as the functioning is concerned, account must be taken of the fact that this is a device for damping progressively according to the speed and the force of the impact. Consequently, when there is a normal closure speed or a normal impact, the resilient fins are supported on the active side of the interior annular projection, without being flexed, and the closure wall of the head of the elastoplastic valve remains at a minimum distance from the seating wall of the cylindrical sleeve. In this case, the dynamic fluid will flow both through the cylindrical sleeve and the elastoplastic valve, and via the exterior of this cylindrical sleeve.
In the case when the impact force is high, there is a high impact, or the closure force is greater, the resilient fins will be supported on the active side of the annular projection, and will be flexed to a greater or lesser extent, depending on the energy which they absorb in the impact, by this means achieving progressive damping. The closure wall of the head of the elastoplastic valve is supported completely on the seating wall of the cylindrical sleeve, such that the passage of the dynamic fluid in the interior of the cylindrical sleeve is closed.
When the fluid absorbs to a large extent the energy of the initial impact, the resilient fins will abandon their flexed position, since the system is balanced. In this position, the head of the elastoplastic valve will be situated in the low-impact position, and there will once more be a minimum distance between the closure wall and the seating wall of the cylindrical sleeve, thus permitting the passage of the fluid through the cylindrical sleeve and the elastoplastic valve, as well as on the exterior of this cylindrical sleeve.
This device must be able to be re-armed for further use, and so on. Consequently it must be ensured that the re-arming process can be undertaken with a lesser effort, i.e. the flow of fluid transferred between the expansion and compression chambers in the re-arming phase must be greater than in the braking phase.
The cylindrical sleeve, for its part, is symmetrical in relation to its two axes, which results in greater ease of assembly and production. Each wall of the cylindrical sleeve will have a different function, depending on the position in which the assembly is carried out.
With reference to the configuration of the elastoplastic valve, in its production there will be no breakage points in the injection process, since this injection need not be carried out at any specific geometric point, and no critical dimensions arise. This facilitates the production process and subsequent assembly, since the part is symmetrical relative to its longitudinal axis.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
In order to understand better the nature of the invention, the attached drawings represent an industrial embodiment, purely by way of illustrative and non-limiting example.
FIG. 1 is a cross-section of the damping device at the beginning of the path, showing in perspective an enlarged detail of the elastoplastic valve ( 6 ), the cylindrical sleeve ( 10 ) and the cylinder body ( 1 ) in dismantled form.
FIG. 2 is a schematic view of the damping device in the position corresponding to the beginning of the path of the piston ( 2 ), indicating the corresponding detail of the elastoplastic valve ( 6 ) and the cylindrical sleeve ( 10 ) in this position.
FIG. 3 is a schematic view of the damping device in the position corresponding to the end of the path of the piston ( 2 ).
FIG. 4 is an enlargement of the detail shown in FIG. 2 , and is a view in cross-section of the damping device at the beginning of the path.
FIG. 5 is a schematic view of the damping device when a low impact occurs during the closure.
FIG. 6 is a schematic view of the damping device when a high impact occurs during the closure.
FIG. 7 shows the cross-section indicated in FIG. 8 , according to line VII-VII′ of the cylindrical sleeve ( 10 ).
FIG. 8 shows the profile of the cylindrical sleeve ( 10 ).
FIG. 9 is the front view of the elastoplastic valve ( 6 ).
FIG. 10 is the profile view of the elastoplastic valve ( 6 ).
FIG. 11 is the plan view of the elastoplastic valve ( 6 ).
In these figures, the following alphanumerical references are given:
1 —Cylinder body
2 —Piston
3 —Piston rod ( 2 )
4 —Chamber for compression in damping
5 —Expansion chamber
6 —Elastoplastic valve of the piston ( 2 )
7 —Resilient fins of the elastoplastic valve ( 6 )
8 —Stops of the elastoplastic valve ( 6 )
9 —Elastoplastic valve head ( 6 )
9 a —Wall which closes the head ( 9 )
10 —Cylindrical sleeve of the piston ( 2 )
10 a —Cylindrical sleeve wall ( 10 )
11 —Interior annular projection of the cylindrical sleeve ( 10 )
11 a —Interior annular projection side ( 11 )
12 —Fluid transfer lines.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the aforementioned references and drawings, the appended plans illustrate a preferred embodiment of the subject of the invention, with reference to a progressive damping device for furniture which, as illustrated in FIG. 1 , comprises a cylinder body ( 1 ) through which a dynamic fluid circulates, and the interior of which comprises a piston ( 2 ) which has a rod ( 3 ) which extends outside the cylinder body ( 1 ), and delimits two chambers, for compression during damping ( 4 ), and for expansion ( 5 ), and which have a variable volume, depending on the position of the piston ( 2 ) ( FIGS. 2 and 3 ).
As illustrated in FIG. 1 , the piston ( 2 ) is a cylindrical sleeve ( 10 ) which contains in its interior a displaceable elastoplastic valve ( 6 ) which is provided with symmetrical resilient fins ( 7 ) with a total radial dimension which is greater than the inner diameter of the interior annular projection ( 11 ) of the cylindrical sleeve ( 10 ), the longitudinal position of these resilient fins ( 7 ) when not flexed being such that their distance to the wall ( 9 a ) which closes the head ( 9 ) of the elastoplastic valve ( 6 ) is greater than the distance between the active side ( 11 a ) of the interior annular projection ( 11 ) and the seating wall ( 10 a ) of the cylindrical sleeve ( 10 ), with these resilient fins ( 7 ) reaching the active side ( 11 a ) of the interior annular projection ( 11 ) before the wall ( 9 a ) which closes the head ( 9 ) of the elastoplastic valve ( 6 ) abuts the seating wall ( 10 a ) of the cylindrical sleeve ( 10 ).
The resilient fins ( 7 ) of the elastoplastic valve ( 6 ) are equidistant, there are preferably two of them, and their radial length is larger than the smaller inner diameter of the interior annular projection ( 11 ) of the cylindrical sleeve ( 10 ), including in the state of flexure of the resilient fins ( 7 ). The dimensions of the length and thickness of these resilient fins ( 7 ) can be determined accurately, and different numbers and forms of the fins can be combined, since it is possible to opt for embodiments with three or four resilient fins ( 7 ), with thicknesses and lengths which differ from one another.
The cylindrical sleeve ( 10 ) has its interior annular projection ( 11 ) with its respective active sides ( 11 a ) equidistant from the respective seating wall ( 10 a ), thus facilitating its reversible assembly.
The point of support of the resilient fins ( 6 ) on the interior annular projection ( 11 ) of the cylindrical sleeve ( 10 ) will be derived from the impact provided in the movement in the direction of damping, on the active side ( 11 a ) of the interior annular projection ( 11 ).
As far as the functioning is concerned, account must be taken of the fact that this is a device for damping progressively according to the speed and the force of the impact.
As can be seen in FIG. 5 , when there is a normal closure speed or a normal impact, the resilient fins ( 7 ) are supported on the active side ( 11 a ) of the interior annular projection ( 11 ), without being flexed, and the closure wall ( 9 a ) of the head of the elastoplastic valve ( 6 ) remains at a minimum distance from the seating wall ( 10 a ) of the cylindrical sleeve ( 10 ). In this case, the dynamic fluid will flow both through the cylindrical sleeve ( 10 ) and the elastoplastic valve ( 6 ), and via the exterior of this cylindrical sleeve ( 10 ).
In the case when the impact force is high, there is a high impact, or the closure force is greater, as illustrated in FIG. 6 , the resilient fins ( 6 ) will be supported on the active side ( 11 a ) of the annular projection ( 11 ), and will be flexed to a greater or lesser extent, depending on the energy which they absorb in the impact, by this means achieving progressive damping. The closure wall ( 9 a ) of the head of the elastoplastic valve ( 6 ) is supported completely on the seating wall ( 10 a ) of the cylindrical sleeve ( 10 ), such that the passage of the dynamic fluid in the interior of the cylindrical sleeve ( 10 ) is closed.
When the fluid absorbs to a large extent the energy of the initial impact, the resilient fins will abandon their flexed position, since the system is balanced. In this position, the head ( 9 ) of the elastoplastic valve ( 6 ) will be situated in the low-impact position, and there will once more be a minimum distance between the closure wall ( 9 a ) and the seating wall ( 10 a ) of the cylindrical sleeve ( 10 ), thus permitting the passage of the fluid through the cylindrical sleeve ( 10 ) and the elastoplastic valve ( 6 ), as well as on the exterior of this cylindrical sleeve ( 10 ).
This device must be able to be re-armed for further use, and so on. Consequently it must be ensured that the re-arming process can be undertaken with a lesser effort, i.e. the cross-section of passage of the flow of fluid transferred between the expansion and compression chambers in the re-arming phase must be greater than in the braking phase.
As illustrated in FIG. 4 , the stops ( 8 ) of the elastoplastic valve ( 6 ) are supported on the interior annular projection ( 11 ) in the re-arming phase, so that the cylindrical sleeve ( 10 ) moves together with the elastoplastic valve ( 6 ).
The cylindrical sleeve, for its part, is symmetrical in relation to its two axes, which results in greater ease of assembly and production. In other words, each wall of the cylindrical sleeve will have a different function, depending on the position in which the assembly is carried out.
With reference to the configuration of the elastoplastic valve ( 6 ), in its production there will be no breakage points in the injection process, since this injection need not be carried out at any specific geometric point, and no critical dimensions arise. This facilitates the production process and subsequent assembly, since the part is symmetrical relative to its longitudinal axis. | A progressive damping device for furniture is designed to prevent impacts between the mobile parts of furniture provided with self-closing systems, and provides progressive closure according to the speed and energy acquired in the closure. The damping device generally includes a cylinder in which a dynamic fluid circulates, and in the interior of which there is displaced a piston which has a rod provided with an elastoplastic valve, which delimits respective compression and expansion chambers. | 4 |
CROSS-REFERENCE TO A RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application Ser. No. 11/493,995 filed on Jul. 27, 2006. The disclosure of the above application is incorporated herein by reference.
FIELD
[0002] The present teachings relate to a fastening tool and more specifically relate to a pusher bearing and a pusher block in a magazine of the fastening tool that more uniformly distributes force on one or more fasteners in the magazine.
BACKGROUND
[0003] A number of pneumatically and electrically operated tools have been developed to drive fasteners, such as staples and nails, into workpieces. Typically, these tools employ a magazine for holding a plurality of the fasteners and feeding the fasteners into a nose of the tool prior to driving the fasteners into the workpiece.
[0004] Despite the widespread use of such tools, it is known that fasteners being fed through the magazine and into a driver blade channel formed in the nosepiece of the fastening tool can jam. In this regard, stack-up tolerances of all of the components of the magazine, plus imperfections in the fasteners, can contribute to the fasteners jamming in the magazine. While jammed fasteners can be readily evacuated from the magazine and the nose, there remains room in the art for improvement.
SUMMARY
[0005] The various aspects of the present teachings generally include a method of urging one or more fasteners toward a nosepiece of a fastening tool. The method includes placing one or more fasteners into a magazine and moving a pusher block that is pivotally mounted on a pusher bearing toward the one or more fasteners. The method also includes rocking the pusher block about the pusher bearing as the one or more fasteners are fed sequentially into the nosepiece to maintain a pushing surface of the pusher block in substantial abutment with a surface of a last fastener of the one or more fasteners.
[0006] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present teachings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present teachings in any way.
[0008] FIG. 1 is a perspective view of a fastening tool constructed in accordance with the present teachings showing a nosepiece and a magazine in a closed position. The nosepiece is shown against a workpiece that places a contact trip mechanism in a retracted condition.
[0009] FIG. 2 is similar to FIG. 1 and shows the magazine in an open position and shows the nosepiece not engaged. With a tip of the nosepiece not engaged, the contact trip mechanism is in an extended condition and the fastening tool cannot be activated by a trigger assembly.
[0010] FIG. 3 is similar to FIG. 2 and shows the trigger assembly, a depth adjustment mechanism and a magazine clip.
[0011] FIG. 4 is an exploded assembly view of the magazine of FIG. 1 showing an outer case, an inner rail, a pusher block and a pusher bearing.
[0012] FIG. 5 is a partial cross-sectional view of FIG. 1 showing the pusher bearing, the pusher block and the fasteners in the magazine having the outer case illustrated as cut-away.
[0013] FIG. 6 is a different partial cross-sectional view of FIG. 1 showing a driver blade channel formed by an outer nose member and an inner nose member of the nosepiece. The inner nose is connected to the magazine, which is in the closed position.
[0014] FIG. 7 is a diagram showing a pushing surface of the pusher block abutting a last fastener in a slightly upward direction because the pusher block is able to rock about the pusher bearing constructed in accordance with the present teachings.
[0015] FIG. 8 is similar to FIG. 7 and shows the pusher block in a slightly downward direction relative the pusher bearing constructed in accordance with the present teachings.
DETAILED DESCRIPTION
[0016] The following description is merely exemplary in nature and is not intended to limit the present teachings, their application or uses. It should be understood that throughout the drawings corresponding reference numerals can indicate like or corresponding parts and features.
[0017] With reference to FIGS. 1 and 2 , the present teachings generally include a fastening tool 10 having a main housing 12 that can contain a driving mechanism 14 for driving one or more fasteners 16 , such as a nail or a staple. The fastening tool 10 can include a handle 18 , a nosepiece 20 that can be disposed below the main housing 12 and a magazine 22 that can be connected to the nosepiece 20 and the handle 18 . A trigger assembly 24 can be disposed on the main housing 12 and/or the handle 18 for activating the driving mechanism 14 , as is known in the art. The driving mechanism 14 can include, for example, pneumatic-based systems such as those shown in commonly assigned U.S. Pat. Nos. 3,673,922 or 5,181,450, or an electrical system such as those shown in U.S. Pat. No. 4,928,868. The above references are hereby incorporated by reference in their entirety as if fully set forth herein.
[0018] With reference to FIGS. 5 and 6 , the magazine 22 can contain the fasteners 16 and can sequentially feed the fasteners 16 into a driver blade channel 26 . Once the fasteners 16 are aligned in the driver blade channel 26 , a driver blade 28 can be extended from a retracted condition ( FIG. 1 ) to drive one of the fasteners 16 out of the driver blade channel 26 and into a workpiece 30 ( FIG. 1 ). The driver blade 28 can extend from the retracted condition to an extended condition, when the driving mechanism 14 is activated via the trigger assembly 24 , as is known in the art.
[0019] With reference to FIGS. 4, 7 and 8 , the magazine 22 can include a pusher bearing 32 that urges a pusher surface 34 on a pusher block 36 against the fasteners 16 to urge the fasteners 16 toward the nosepiece 20 . Because the pusher block 36 can move relative to the pusher bearing 32 , it can be shown that the pusher block 36 can provide relatively more uniform pressure against the fasteners 16 as the pusher block 36 urges the fasteners 16 toward the nosepiece 20 . Because the pusher block 36 can move or rock about the pusher bearing 32 , the pusher surface 34 of the pusher block 36 can be disposed at a non-parallel orientation relative the pusher bearing 32 and a pusher rod or bar 38 on which the pusher bearing 32 slides. Because the pusher surface 34 can abut the fasteners 16 in an orientation that is not parallel to a force exerted against the pusher block 36 , it can be shown that the propensity for the fasteners 16 to jam in the magazine 22 can be reduced relative to a pusher block (not shown) that is slidable within the magazine but which is otherwise not moveable or able to rock about a pusher rod or other suitable portions of the magazine 22 .
[0020] With reference to FIGS. 3, 4 and 6 , the contact trip mechanism 42 can include a lower member 40 . The lower member 40 can have a first portion 44 that is associated with the nosepiece 20 and can be coupled to a tip 46 that can contact the workpiece 30 ( FIG. 1 ). A second portion 48 of the lower member 40 can be coupled to a depth adjustment mechanism 50 disposed beneath the trigger assembly 24 . When the tip 46 is pressed against the workpiece 30 , as shown in FIG. 1 , the contact trip mechanism 42 can move from an extended condition to a retracted condition. When the contact trip mechanism 42 is positioned in the retracted condition, the contract trip mechanism 42 can permit the driving mechanism 14 of the fastening tool 10 to be activated via the trigger assembly 24 , as is known in the art. When the contact trip mechanism 42 is positioned in the extended condition, the fastening tool 10 cannot be activated.
[0021] The trigger assembly 24 can have a main trigger 52 that can be pivotally attached to the main housing 12 or the handle 18 and a supplemental trigger 54 that can be pivotally attached to the main trigger 52 . When the main trigger 52 and the contact trip mechanism 42 are activated (i.e., the lower member 40 , the tip 46 , etc. move to the retracted condition), the supplemental trigger 54 can move a valve or a switch to activate the driving mechanism 14 . It will be appreciated that the supplemental trigger 54 can move a switch when the driving mechanism 14 is an electric system or an airflow control valve when the driving mechanism 14 is a pneumatic system. Operation of the trigger assembly in combination with the contact trip assembly is well known in the art and is described in, for example, commonly assigned U.S. Pat. No. 5,785,228, which is incorporated by reference in its entirety as if fully set forth herein.
[0022] With reference to FIGS. 3 and 5 , the magazine 22 includes an outer case 56 in which an inner rail 58 can slide from an open position ( FIG. 3 ) to a closed position ( FIG. 1 ). In the open position, one or more of the fasteners 16 can be added to the magazine 22 , albeit in a position where the inner rail 58 is moved farther away from the nosepiece 20 than what is illustrated in FIG. 3 . The inner rail 58 can then be closed, i.e., moved to the closed position, as shown in FIG. 1 , to urge the fasteners 16 against the nosepiece 20 and thus align one of the fasteners 16 in the driver blade channel 26 , as shown in FIG. 6 .
[0023] The pusher block 36 can be in an upside down U-shaped configuration and ride over a top member 60 of the inner rail 58 . In this regard, the pusher surface 34 can be defined by a pair of walls 62 connected by a top portion 64 of the pusher block 36 . The pusher surface 34 can be disposed to generally match the orientation of the fasteners 16 , e.g., a surface of one staple 66 (i.e., the last staple) abuts the pusher surface 34 where the staple 66 and the pusher surface 34 are ideally parallel, as shown in FIGS. 7 and 8 .
[0024] The pusher block 36 can be made of acetal, which can be also be known as polyacetal, polyoxymethylene or polyformaldehyde. Other suitably performing polymers can also be used to form the pusher block 36 . For example, the pusher block can be made of Delrin® readily available from DuPont or Celcon® readily available from Ticona (Florence, Ky.).
[0025] When the pusher block 36 is made of acetal or other suitable material, the pusher block 36 has a coefficient of friction that can be less than or equal to the coefficient of friction of the inner rail 58 and/or the outer case 56 on and/or in which the pusher block 36 slides. The inner rail 58 and the outer case 56 can be made of aluminum or other suitable metals or plastics. The ability of the pusher block 36 to more easily slide along the inner rail 58 can reduce the propensity of the fasteners 16 jamming in the magazine 22 .
[0026] The inner rail 58 can include a front end 68 and a rear end 70 . The pusher rod or bar 38 can be disposed between the front end 68 and the rear end 70 . An inner nose member 72 associated with the nosepiece 20 can connect to the front end 68 , while a magazine bumper 74 can connect to the rear end 70 .
[0027] When the inner rail 58 is moved to the closed position ( FIG. 1 ), the inner nose member 72 approaches an outer nose member 76 , also of the nosepiece 20 , but can remain spaced from the outer nose member 76 . The spacing between the outer nose member 76 and the inner nose member 72 can be sufficient to define the driver blade channel 26 , (i.e. the channel through which one of fasteners 16 travels as it is driven into the workpiece 30 ). Moreover, the fasteners 16 can be urged against a surface of the outer nose member 76 that can face the driver blade channel 26 and thus align one of the fasteners 16 in the driver blade channel 26 , as shown in FIG. 5 .
[0028] A nose cover 78 can connect to the outer nose member 76 to form a front face 80 of the nosepiece 20 . The nose cover 78 can, moreover, hold heads 82 of fasteners that can couple the nosepiece 20 to the magazine 22 .
[0029] The pusher bearing 32 can be formed with a through hole 84 that slidably receives the pusher rod 38 . In addition, a spring 86 can be disposed over the pusher rod 38 such that the pusher rod 38 is threaded through the spring 86 . The spring 86 can be coupled to the pusher bearing 32 to bias the pusher bearing 32 towards the nosepiece 20 . The pusher bearing 32 can, in turn, be coupled to the pusher block 36 .
[0030] The pusher block 36 can define a pair of rounded apertures 88 formed in each of the walls 62 that can be configured to receive the pusher bearing 32 . The pusher bearing 32 can also have a rounded or semi-cylindrical configuration ( FIG. 4 ) that can be received in the apertures 88 of the walls 62 of the pusher block 36 . In this regard, a ball and socket joint 90 can be formed between the pusher bearing 32 and the pusher block 36 . The rounded configuration of the pusher block apertures 88 and the pusher bearing 32 can permit the pusher block 36 to move (i.e., pivot) relative to the pusher bearing 32 as the pusher bearing 32 urges the pusher block 36 , and the fasteners 16 , toward the nosepiece 20 .
[0031] The pusher bearing 32 can have walls 92 that can be generally parallel to one another. The pusher bearing 32 can also have a generally cylindrical surface 94 that can be bounded by the walls 92 . An imaginary line 96 can extend in a direction generally normal to the cylindrical surface 94 . The imaginary line 96 can also be generally perpendicular to an imaginary line 98 that can extend from one the walls 92 . The walls 62 of the pusher block can be generally flush with the walls 92 of the pusher bearing 32 . As such, the pusher block apertures 88 can have an arcuate surface 100 that can receive the cylindrical surface 94 of the pusher bearing 32 . The pusher block 36 , therefore, can be operable to move or rock relative to or about the pusher bearing 32 , as the pusher bearing 32 urges the pusher block 36 , and the fasteners 16 , toward the nosepiece 20 .
[0032] For example and with reference to FIGS. 7 and 8 , a force applied by the spring 86 in a first direction 102 can be, in turn, applied by the pusher surface 34 to the staple 66 in a second direction 104 . The first direction 102 and the second direction 104 , in some instances, are not parallel and the second direction 104 need not be parallel to the pusher rod 38 . Since the pusher block 36 is able to move about the pusher bearing 32 , the pressure applied to the fasteners 16 by the pusher block 36 can be more uniform as compared to a pusher block that is rigidly attached to a pusher bearing or other suitable portion of a magazine.
[0033] With reference to FIG. 3 , the magazine 22 can be coupled to the main housing 12 and/or the handle 18 at a first connection point 106 and a second connection point 108 . The first connection point 106 can be adjacent to the nosepiece 20 such that a front end 110 of the magazine 22 can be coupled to the nosepiece 20 to form the driver blade channel 26 therebetween. At the second connection point 108 , the magazine 22 connects to a rear end 112 of the handle 18 .
[0034] At the second connection point 108 , the housing 12 can include a magazine clip 114 . The magazine clip 114 ( FIG. 4 ) can pivot on a pin 116 that is coupled to the handle 18 . Moreover, a spring 118 can bias the magazine clip 114 in a locked position, as shown in FIG. 1 . By pressing the magazine clip 114 toward the housing 12 and against the bias of the spring 118 , the magazine clip 114 can be moved from the locked position to an unlocked position. With the magazine clip 114 in the unlocked position, the inner rail 58 can be extracted from the outer case 56 of the magazine 22 and pulled away from the nosepiece 20 , as shown in FIG. 3 . By pulling the inner rail 58 out and away from the nosepiece 20 , the fasteners 16 can be added to the magazine 22 to replenish the fasteners 16 in the magazine 22 .
[0035] When fasteners 16 are added to the magazine 22 , the inner rail 58 can be returned to the closed position, as shown in FIG. 1 . The magazine bumper 74 that can be connected to the inner rail 58 , can engage the magazine clip 114 to hold the magazine 22 in the closed position, as also shown in FIG. 1 .
[0036] With reference to FIGS. 6, 7 and 8 , when one or more fasteners 16 are contained within the magazine 22 , the pusher block 36 will necessarily butt up against the last fastener (e.g. the staple 66 ) contained in the magazine 22 opposite the nosepiece 20 . The spring 86 over the pusher rod 38 will be compressed between the pusher bearing 32 and the magazine bumper 74 ( FIG. 3 ) and thereby bias pusher bearing 32 in a first direction toward nosepiece 20 . The force exerted on the pusher block 36 is transferred to the fasteners 16 thus urging the fasteners 16 toward the nosepiece 20 to dispense the fasteners 16 into the driver blade channel 26 . Because the pusher block 36 can move about the pusher bearing 32 , the pusher surface 34 can apply pressure to the fasteners 16 in a second direction 104 that is not parallel to the first direction 102 . Moreover, the pusher block 36 can rock about the pusher bearing 32 such that the second direction 104 can form an acute angle with the first direction upwardly and/or downwardly relative to the examples illustrated in FIGS. 7 and 8 .
[0037] While specific aspects have been described in this specification and illustrated in the drawings, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the present teachings, as defined in the claims. Furthermore, the mixing and matching of features, elements and/or functions between various aspects of the present teachings may be expressly contemplated herein so that one skilled in the art will appreciate from the present teachings that features, elements and/or functions of one aspect of the present teachings may be incorporated into another aspect, as appropriate, unless described otherwise above. Moreover, many modifications may be made to adapt a particular situation, configuration or material to the present teachings without departing from the essential scope thereof. Therefore, it may intended that the present teachings not be limited to the particular aspects illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out the present teachings but that the scope of the present teachings will include many aspects and examples following within the foregoing description and the appended claims. | A method of urging one or more fasteners toward a nosepiece of a fastening tool generally includes placing one or more fasteners into a magazine and moving a pusher block that is pivotally mounted on a pusher bearing toward the one or more fasteners. The method also includes rocking the pusher block about the pusher bearing as the one or more fasteners are fed sequentially into the nosepiece to maintain a pushing surface of the pusher block in substantial abutment with a surface of a last fastener of the one or more fasteners. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2015-003810, filed on Jan. 13, 2015, the entire contents of which are incorporated herein by reference.
FIELD
[0002] The embodiments discussed herein are related to a heat exchanger, a cooling unit, and an electronic device.
BACKGROUND
[0003] Recently, miniaturization of electronic devices such as a desktop personal computer, a mobile personal computer, and a server is being promoted. Electronic components such as a central processing unit (CPU) used in these electronic devices generate heat as they are operated.
[0004] When the temperature of the electronic components such as the CPU exceeds a permissible upper temperature limit, a problem such as a failure, malfunction, or a decrease in processing capability is caused. Thus, a means for cooling an electronic component that generates a large amount of heat is required.
[0005] An air-cooling method and a water-cooling method are used to cool the electronic components. In the case of cooling an electronic component that generates a large amount of heat, the water-cooling method is often employed. Hereinafter, the electronic component that generates a large amount of heat will be referred to as a heat generation component.
[0006] In a water-cooling type cooling apparatus, a heat receiving part is mounted on the heat generation component, and a heat exchanger and a cooling fan are arranged at a location that is spaced away from the heat receiving part, and the heat receiving part and the heat exchanger are connected to each other via a pipe. The heat receiving part is provided with a flow path through which the cooling water flows. By circulating the cooling water between the heat receiving part and the heat exchanger, the heat generated from the heat generation component is transferred to the heat exchanger, and then is dissipated from the heat exchanger to the atmosphere. The heat exchanger is provided with a plurality of heat radiation fins along a flow path through which a refrigerant flows.
[0007] Further, herein, water or other fluids (refrigerant) that are used for transferring heat from the heat receiving part to the heat exchanger will be referred to as “cooling water.”
[0008] With the miniaturization of the electronic device, miniaturization is also required for the heat exchanger mounted in the electronic device. However, when the size of the heat exchanger is merely reduced, the flow path of the cooling water is narrowed so that a pressure loss increases and the flow rate of the cooling water flowing in the heat exchanger and the heat receiving part is reduced. Consequently, the heat exchange efficiency of the heat exchanger is lowered so that the heat generation component may not be sufficiently cooled.
[0009] The followings are a reference documents.
[0010] [Document 1] Japanese Laid-Open Patent Publication No. 2014-053507,
[0011] [Document 2] Japanese Laid-Open Patent Publication No. 2014-052142,
[0012] [Document 3] Japanese Examined Utility Model Registration Application Publication No. 02-005326 and
[0013] [Document 4] Japanese Laid-Open Patent Publication No. 11-230638.
SUMMARY
[0014] According to an aspect of the invention, a heat exchanger includes: a plurality of first heat radiation members, each of the plurality of first heat radiation members including a first refrigerant flow path through which a refrigerant flows; a plurality of second heat radiation members, each of the plurality of second heat radiation members including a second refrigerant flow path through which the refrigerant flows; and a fin attached between the plurality of second heat radiation members, wherein an interval between the plurality of first heat radiation members is smaller than an interval between the plurality of second heat radiation members.
[0015] The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims.
[0016] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF DRAWINGS
[0017] FIG. 1 is a perspective view illustrating a heat exchanger according to a first exemplary embodiment;
[0018] FIG. 2 is a front view illustrating the heat exchanger according to the first exemplary embodiment;
[0019] FIG. 3 is a sectional view illustrating a first header portion;
[0020] FIG. 4 is a sectional view illustrating a second header portion;
[0021] FIG. 5 is a perspective view illustrating a cooling unit including the heat exchanger according to the first exemplary embodiment;
[0022] FIG. 6 is a block diagram illustrating the configuration of the cooling unit;
[0023] FIG. 7 is a perspective view illustrating an electronic device including the cooling unit;
[0024] FIG. 8 is a side view illustrating the interior of the electronic device;
[0025] FIG. 9 is a plan view illustrating the interior of the electronic device;
[0026] FIG. 10 is a perspective view illustrating a heat exchanger according to a second exemplary embodiment;
[0027] FIG. 11 is a perspective view illustrating the heat exchanger according to the second exemplary embodiment;
[0028] FIG. 12 is a sectional view illustrating a first header portion;
[0029] FIG. 13 is a sectional view illustrating a second header portion;
[0030] FIG. 14 is a perspective view illustrating a cooling unit including the heat exchanger according to the second exemplary embodiment; and
[0031] FIG. 15 is a side view illustrating the interior of an electronic device including the cooling unit.
DESCRIPTION OF EMBODIMENTS
[0032] Hereinafter, exemplary embodiments will be described with reference to the accompanying drawings.
First Exemplary Embodiment
[0033] FIG. 1 is a perspective view of a heat exchanger 20 according to a first exemplary embodiment, and FIG. 2 is a front view of the same heat exchanger 20 .
[0034] The heat exchanger 20 according to this exemplary embodiment includes a first header portion 21 , a pair of second header portions 22 disposed with the first header portion 21 being interposed therebetween, and first and second heat radiation members 23 and 24 that interconnect the first header portion 21 and the second header portions 22 .
[0035] All the first and second heat radiation members 23 and 24 are tube-shaped or plate-shaped members, each having therein a space through which the cooling water flows. The first heat radiation members 23 and the second heat radiation members 24 are disposed horizontally such that a plurality of first heat radiation members and a plurality of second heat radiation members are arranged side by side in the vertical direction, respectively.
[0036] In the present exemplary embodiment, a plate-shaped member called a perforated pipe is used as the first and second heat radiation members 23 and 24 . In the perforated pipe, a plurality of holes, which perforate the perforated pipe from one end surface to the other end surface thereof, are provided in parallel. According to this exemplary embodiment, as illustrated in FIGS. 1 and 2 , five first heat radiation members 23 are located at a lower side, while five second heat radiation members 24 are located at an upper side. In other words, in this exemplary embodiment, the first and second heat radiation members 23 and 24 are arranged side by side in a height direction.
[0037] Further, the number of each of the first and second heat radiation members 23 and 24 may be set as appropriate, without being limited to five (5). Further, the number of the first heat radiation members 23 may be different from the number of the second heat radiation members 24 .
[0038] A plurality of heat radiation fins 25 are provided between the second heat radiation members 24 . In order to install these fins 25 , the interval between neighboring second heat radiation members 24 is set to be relatively large. In contrast, no fin is provided between the first heat radiation members 23 , and the interval between the first heat radiation members 23 is set to be relatively small.
[0039] The first heat radiation members 23 , the second heat radiation members 24 , and the fins 25 are made of a metal having good heat conductivity such as, for example, aluminum or copper.
[0040] FIG. 3 is a sectional view illustrating the first header portion 21 , and FIG. 4 is a sectional view illustrating the second header portion 22 .
[0041] As illustrated in FIG. 3 , the first header portion 21 is provided with a cooling water inlet 27 a and a cooling water outlet 27 b. Further, the first header portion 21 is partitioned into a first space 51 connected to the cooling water inlet 27 a and a second space S 2 connected to the cooling water outlet 27 b, by a partition wall 21 a. The first space 51 is located at a lower side, while the second space S 2 is located at an upper side. The cooling water inlet 27 a is an example of a first connection port, and the cooling water outlet 27 b is an example of a second connection port.
[0042] The first space 51 is connected to a hole (hereinafter, referred to as a “cooling water flow path 23 a ”) of the first heat radiation member 23 , and the second space S 2 is connected to a hole (hereinafter, referred to as a “cooling water flow path 24 a ”) of the second heat radiation member 24 .
[0043] The cooling water flowing from the cooling water inlet 27 a into the first space S 1 of the first header portion 21 further enters the cooling water flow path 23 a of the first heat radiation member 23 , and then moves to the second header portion 22 through the cooling water flow path 23 a.
[0044] As illustrated in FIG. 4 , the second header portion 22 is provided with a third space S 3 that connects the cooling water flow path 23 a of the first heat radiation member 23 with the cooling water flow path 24 a of the second heat radiation member 24 . The cooling water, which has entered the second header portion 22 from the cooling water flow path 23 a of the first heat radiation member 23 , flows upwards in the second header portion 22 , and then enters the cooling water flow path 24 a of the second heat radiation member 24 . Further, the cooling water moves to the second space S 2 of the first header portion 21 through the cooling water flow path 24 a of the second heat radiation member 24 , and is discharged from the cooling water outlet 27 b.
[0045] FIG. 5 is a perspective view illustrating a cooling unit 30 having the above-described heat exchanger 20 , and FIG. 6 is a block diagram illustrating the configuration of the same cooling unit 30 . Further, FIG. 7 is a perspective view illustrating an electronic device 40 having the same cooling unit 30 , FIG. 8 is a side view illustrating an interior of the same electronic device 40 , and FIG. 9 is a plan view illustrating the interior of the same electronic device 40 . Furthermore, arrows in FIG. 6 indicate the flow direction of the cooling water.
[0046] As illustrated in FIGS. 5 and 6 , the cooling unit 30 includes a heat exchanger 20 , a heat receiving part 31 , a pump 32 , and a tank 33 . The heat receiving part 31 is provided with a flow path through which the cooling water flows, and is thermally connected to a heat generation component 11 (see, e.g., FIG. 8 ). Further, the heat generation component 11 and other electronic components are mounted on a circuit board 10 .
[0047] The cooling water inlet 27 a of the heat exchanger 20 is connected to the cooling water flow path in the heat receiving part 31 through a pipe 28 a . Further, the cooling water outlet 27 b is connected to the tank 33 through a pipe 28 b. Further, as illustrated in FIG. 6 , the tank 33 and the pump 32 are connected to each other by a cooling water flow path 34 a, and the pump 32 and the heat receiving part 31 are connected to each other by a cooling water flow path 34 b.
[0048] According to this exemplary embodiment, a plurality of pumps 32 (e.g., six pumps in FIG. 5 ) are connected in parallel between the tank 33 and the heat receiving part 31 to increase the flow rate of the cooling water. In this regard, the number of the pumps 32 may be set as appropriate. For example, the number of the pumps 32 may be one (1).
[0049] As illustrated in FIGS. 5 and 8 , the cooling unit 30 is secured to the circuit board 10 by, for example, four locking pins 35 and springs 36 .
[0050] The electronic device 40 includes a case 41 , a circuit board 10 , a cooling unit 30 , and a cooling fan 42 . The circuit board 10 , the cooling unit 30 , and the fan 42 are disposed within the case 41 . In the electronic device 40 illustrated in FIGS. 7 and 8 , a plurality of fans 42 are disposed on an end of the case 41 , and a duct 43 is provided between the fans 42 and the heat exchanger 20 to guide air from the fans 42 to the heat exchanger 20 .
[0051] Hereinafter, an operation of the cooling unit 30 according to this exemplary embodiment will be described.
[0052] The heat generation component 11 generates heat while being operated. However, since the heat generation component 11 is thermally connected to the heat receiving part 31 (see, e.g., FIGS. 6 and 8 ), the heat generation component 11 is cooled by the cooling water flowing in the heat receiving part 31 so that the temperature is kept under a permissible upper temperature limit. Further, the temperature of the cooling water flowing in the heat receiving part 31 rises as the heat generation component 11 is cooled.
[0053] The high-temperature cooling water discharged from the heat receiving part 31 flows into the first space S 1 of the first header portion 21 of the heat exchanger 20 through the pipe 28 a and the cooling water inlet 27 a . Further, the cooling water flows from the first space S 1 into the third space S 3 of the second header portion 22 through the first heat radiation member 23 . Furthermore, the cooling water flows from the second header portion 22 into the second space S 2 of the first header portion 21 through the second heat radiation member 24 (see, e.g., FIGS. 3 and 4 ).
[0054] When the cooling water passes through the first and second heat radiation members 23 and 24 , a heat exchange process is performed between the air sent by the fans 42 and the cooling water passing through the first and second heat radiation members 23 and 24 , so that the temperature of the cooling water drops.
[0055] The low-temperature cooling water discharged from the cooling water outlet 27 b of the heat exchanger 20 flows into the tank 33 through the pipe 28 b. Further, the cooling water is temporarily stored in the tank 33 , and then is transferred to the heat receiving part 31 by the pumps 32 (see, e.g., FIG. 6 ).
[0056] Thus, the cooling unit 30 according to the present exemplary embodiment sequentially circulates the cooling water through the heat receiving part 31 , the heat exchanger 20 , the tank 33 , and the pumps 32 , so that heat generated from the heat generation component 11 is transferred to the heat exchanger 20 , and is dissipated from the heat exchanger 20 to the atmosphere.
[0057] For example, when the size of the heat exchanger is simply reduced as in the related art, the cooling water flow path of the heat radiation member is narrowed and the flow rate of the cooling water capable of flowing in the heat exchanger decreases. Further, the density of the fins increases, so that a significant pressure loss occurs in the air passing through the heat exchanger. Hence, when the size of the heat exchanger is simply reduced as in the related art, this leads to a considerable reduction in the heat exchange efficiency of the heat exchanger.
[0058] Whereas, the heat exchanger 20 according to the present exemplary embodiment is configured such that no fin is provided between the first heat radiation members 23 and the interval between the first heat radiation members 23 is small. Thus, the size of the heat exchanger may be reduced without reducing the size of the heat radiation members (e.g., the first and second heat radiation members 23 and 24 ). Further, since it is not necessary to reduce the size of the heat radiation members, a large amount of cooling water may flow into the heat exchanger 20 .
[0059] Further, the heat exchanger 20 according to the present exemplary embodiment may be configured such that the interval between the first heat radiation members 23 is small and the interval between the second heat radiation members 24 is large. Thus, the fins 25 may be arranged at a proper density between the second heat radiation members 24 . As described above, when the size of the heat exchanger according to the related art is merely reduced, the density of fins increases so that a significant pressure loss occurs in the air passing through the heat exchanger, but such a problem may be avoided in the heat exchanger 20 according to the present exemplary embodiment.
[0060] In the present exemplary embodiment, since no fin exists between the first heat radiation members 23 , a pressure loss may decrease in the air passing through the heat exchanger 20 so that the entire cooling capacity of the apparatus is improved. Moreover, since the miniaturization of the apparatus may be realized without reducing the size of the heat radiation members 23 and 24 , a pressure loss in the flow paths of the heat radiation members 23 and 24 may also be reduced, and consequently the flow rate of the cooling water may increase. Therefore, the temperature of the cooling water discharged from the heat exchanger 20 may be sufficiently lowered.
[0061] For example, according to the heat exchanger 20 of the present exemplary embodiment, the flow rate of the cooling water may increase 1.7 times while the flow rate of the air increases 1.2 times, as compared to the conventional heat exchanger having the same size. Accordingly, the heat exchanger 20 of the present exemplary embodiment has sufficiently high heat exchange efficiency even if the heat exchanger 20 is miniaturized. Further, since the cooling unit 30 and the electronic device 40 use the heat exchanger 20 that has high heat exchange efficiency, the heat generation component 11 may be sufficiently cooled.
[0062] Further, in the exemplary embodiment, descriptions have been made on a case where the second header portions 22 , the first heat radiation members 23 , and the second heat radiation members 24 are disposed on the opposite sides of the first header portion 21 , respectively. However, the second header portion 22 , the first heat radiation member 23 and the second heat radiation member 24 may be disposed on only one side of the first header portion 21 .
Second Exemplary Embodiment
[0063] FIG. 10 is a perspective view illustrating a heat exchanger 50 according to a second exemplary embodiment when viewed from a rear side, and FIG. 11 is a perspective view illustrating the same heat exchanger 50 when viewed from a front side. Here, for the convenience of description, a side where a cooling water inlet 57 a and a cooling water outlet 57 b are provided is referred to as a front side while the opposite side thereof is referred to as a rear side.
[0064] The heat exchanger 50 according to the present exemplary embodiment includes a first header portion 51 , a pair of second header portions 52 disposed with the first header portion 51 being interposed therebetween, and first and second heat radiation members 53 and 54 that interconnect the first and second header portions 51 and 52 . As in the first exemplary embodiment, a perforated pipe is used as each of the first and second heat radiation members 53 and 54 in the present exemplary embodiment.
[0065] The first heat radiation members 53 and the second heat radiation members 54 are disposed horizontally such that a plurality of first heat radiation members and a plurality of second heat radiation members are arranged side by side in the vertical direction, respectively. According to the present exemplary embodiment, as illustrated in FIGS. 10 and 11 , the plurality of first heat radiation members 53 are arranged in the front side (the side where a cooling water inlet 57 a and a water outlet 57 b are located), while the plurality of second heat radiation members 54 are arranged in the rear side. That is, in the present exemplary embodiment, assuming that the height direction is defined as a first direction, the direction where a first refrigerant flow path 53 a extends is defined as a second direction, and the direction perpendicular to the first and second directions is defined as a third direction, the first and second heat radiation members 53 and 54 are arranged side by side in the third direction (front-rear direction).
[0066] The interval between the second heat radiation members 54 is set to be relatively large. Further, a plurality of heat radiation fins 25 are disposed at a suitable interval between the second heat radiation members 54 . Meanwhile, no fin exists between the first heat radiation members 53 , and the interval between the first heat radiation members 53 is set to be relatively small.
[0067] FIG. 12 is a sectional view illustrating the first header portion 51 , and FIG. 13 is a sectional view illustrating the second header portion 52 .
[0068] As illustrated in FIG. 12 , a cooling water inlet 57 a and a cooling water outlet 57 b are provided in the first header portion 51 . Further, the first header portion 51 is partitioned into a first space 51 connected to the cooling water inlet 57 a and a second space S 2 connected to the cooling water outlet 57 b, by a diaphragm 51 a. The first space 51 is connected to a hole (hereinafter, referred to as a “cooling water flow path 53 a ”) of the first heat radiation member 53 , and the second space S 2 is connected to a hole (hereinafter, referred to as a “cooling water flow path 54 a ”) of the second heat radiation member 54 .
[0069] The cooling water, which has entered the first space 51 of the first header portion 51 from the cooling water inlet 57 a, further enters the cooling water flow path 53 a of the first heat radiation member 53 , and moves to the second header portion 52 through the cooling water flow path 53 a.
[0070] As illustrated in FIG. 13 , the second header portion 52 is provided with a third space S 3 that connects the cooling water flow path 53 a of the first heat radiation member 53 with the cooling water flow path 54 a of the second heat radiation member 54 . The cooling water, which has entered the second header portion 52 from the cooling water flow path 53 a of the first heat radiation member 53 , flows in the second header portion 52 in a direction from the front side to the rear side, and then, enters the cooling water flow path 54 a of the second heat radiation member 54 . Further, the cooling water moves to the second space S 2 of the first header portion 51 through the cooling water flow path 54 a of the second heat radiation member 54 , and then is discharged from the cooling water outlet 57 b.
[0071] FIG. 14 is a perspective view illustrating a cooling unit 60 having the above-described heat exchanger 50 , and FIG. 15 is a side view illustrating the interior of an electronic device 70 including the cooling unit 60 of FIG. 14 . Components of FIGS. 14 and 15 , which are the same as those of FIGS. 5 and 8 , will be denoted by the same reference numerals.
[0072] As illustrated in FIG. 14 , the cooling unit 60 has a heat exchanger 50 , a heat receiving part 31 , a pump 32 , and a tank 33 . The cooling water inlet 57 a of the heat exchanger 50 is connected to a cooling water flow path in the heat receiving part 31 via a pipe 28 a, while the cooling water outlet 57 b is connected to the tank 33 via a pipe 28 b.
[0073] As illustrated in FIGS. 14 and 15 , the cooling unit 60 is secured to the circuit board 10 by, for example, four locking pins 35 and springs 36 .
[0074] Further, as illustrated in FIG. 15 , the electronic device 70 includes a case 41 , a circuit board 10 , a cooling unit 60 , and a cooling fan 42 . The circuit board 10 , the cooling unit 60 , and the cooling fan 42 are disposed in the case 41 .
[0075] Since a cooling water circulation course is the same as the first exemplary embodiment, a detailed description thereof will be omitted here.
[0076] As in the first exemplary embodiment, in the present exemplary embodiment, no fin exists between the first heat radiation members 53 and the interval between the first heat radiation members 53 is set to be small. Further, the heat exchanger 50 according to the present exemplary embodiment is configured such that the interval between the first heat radiation members 53 is small and the interval between the second heat radiation members 54 is set to be large. Thus, the fins 25 are arranged at a proper density between the second heat radiation members 54 .
[0077] In this regard, similarly to the heat exchanger 20 according to the first exemplary embodiment, the heat exchanger 50 according to the present exemplary embodiment has sufficiently high heat exchange efficiency even if it is miniaturized. Further, since the cooling unit 60 and the electronic device 70 according to the present exemplary embodiment use the heat exchanger 50 that has high heat exchange efficiency, the heat generation component 11 may be sufficiently cooled down.
[0078] Further, in the exemplary embodiment, descriptions have been made on a case where the second header portions 52 , the first heat radiation members 53 , and the second heat radiation members 54 are disposed on the opposite sides of the first header portion 51 . However, the second header portion 52 , the first heat radiation member 53 , and the second heat radiation member 54 may be disposed on only one side of the first header portion 51 .
[0079] All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to an illustrating of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention. | A heat exchanger includes: a plurality of first heat radiation members, each of the plurality of first heat radiation members including a first refrigerant flow path through which a refrigerant flows; a plurality of second heat radiation members, each of the plurality of second heat radiation members including a second refrigerant flow path through which the refrigerant flows; and a fin attached between the plurality of second heat radiation members, wherein an interval between the plurality of first heat radiation members is smaller than an interval between the plurality of second heat radiation members. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Patent Application Ser. No. 60/744,535, filed Apr. 10, 2006, the entirety of which is hereby incorporated by reference.
THE FIELD OF THE INVENTION
[0002] The present invention is directed generally to the field of hip arthroplasty. This invention relates generally to surgical instruments and more particularly to an apparatus and method for implanting prostheses during surgery. The invention is specifically directed to an improved acetabular impactor uniquely constructed for use in less and minimally invasive hip surgeries.
BACKGROUND OF THE INVENTION
[0003] A joint generally consists of two relatively rigid bony structures that maintain a relationship with each other. Soft tissue structures spanning the bony structures hold the bony structures together and aid in defining the motion of one bony structure relative to the other. In the hip, for example, the bony structures are the pelvis and the femur. Soft tissue such as ligaments, tendons and capsule span the joint and provide stability. A smooth and resilient surface consisting of articular cartilage covers the articulating structures. The articular surfaces of the bony structures work in concert with the soft tissue structures to form a mechanism that defines the envelope of motion between the structures. When the joint is taken through a full range of motion, the motion defines a total envelope of motion between the bony structures. Within a typical envelope of motion, the bony structures move in a predetermined pattern with respect to one another. In the example of the hip joint, the joint is a ball in socket joint that is inherently stable. The capsule and ligaments spanning the hip joint provide stability while the muscles provide motion.
[0004] Degenerative arthritis causes progressive pain, swelling, and stiffness of the joints. As the arthritis progresses the joint surfaces wear away and progression of the disease process increases pain and reduces mobility. Treatment of the afflicted articular bone surfaces depends, among other things, upon the severity of the damage to the articular surface and the age and general physical robustness of the patient. Commonly, for advanced arthritis, joint replacement surgery is necessary wherein the articulating elements of the joint are replaced with artificial elements commonly consisting of a part made of metal articulating with a part made of ultra high molecular weight polyethylene (UHMWPE). More recently, metal on metal and ceramic on ceramic bearing surfaces have gained in popularity. Early techniques for performing total joint arthroplasty involved large incisions and surgical exposures. Excessive trauma to soft tissue structures leads to significant intraoperative blood loss, postoperative pain, prolonged hospital stay, and slower recovery. The exposure must be sufficient to permit the introduction of drills, reamers, broaches and other instruments for cutting or removing cartilage and bone that subsequently is replaced with artificial surfaces.
[0005] For total hip replacement, the acetabular articular surface and subchondral bone are removed by hemi-spherical reamers. The femoral head is resected with an oscillating saw, the femoral canal may be prepared with reamers and the proximal medullary canal is shaped with broaches. Traditionally, the acetabulum is prepared with hemi-spherical reamers supported on straight drive handles and powered by a surgical drill. Extensive surgical exposure is needed to properly orient the acetabular reamer relative to the acetabulum. This has resulted in a need for instruments that take maximum advantage of available space.
[0006] Examples of instruments specifically described as being designed for minimally invasive hip surgery are shown in, for example, U.S. Pub. 2004/0153063 (Harris), U.S. Pat. No. 7,004,946 (Parker et al), U.S. Pat. No. 7,037,310 (Murphy), and U.S. Pub. 2006/0149285 (Burgi et al). While these devices may be acceptable for their intended purposes or described uses, each requires displacement of the femur to some extent to place the impactor handle and to impact the acetabular shell.
[0007] For patients who require hip replacement surgery it is desirable to provide surgical methods and apparatuses that enable preparation of implant support surfaces and implant placement without substantial damage or trauma to associated muscles, ligaments or tendons. Such minimally invasive total hip surgery reduces exposure of the joint cavity, and the size and location of the minimally invasive incision may not be optimal for proper orientation and application of force to adequately seat and stabilize an acetabular implant. Thus, an impaction device is needed that allows for impaction of the acetabular component with the hip reduced or articulated for use with a minimally invasive exposure for total hip arthroplasty. It may also be desirable to use an alignment guide or surgical navigation to aid the surgeon in positioning the acetabular implant. To attain this goal, a system and method is needed to enable articulating surfaces of the joints to be appropriately sculpted and implants to be placed using minimally invasive apparatuses and procedures. What is needed is an acetabular cup impactor that is more easily placed into the joint space, maintains the femur in an anatomical position and enables cup impaction.
SUMMARY OF THE INVENTION
[0008] The present invention provides an apparatus and method for acetabular cup impaction during hip arthroplasty involving minimally invasive surgical procedures. The acetabular cup impactor disclosed accomplishes accurate implant orientation and implant fixation through a limited surgical exposure.
[0009] An acetabular component, such as a press fit shell, is implanted following preparation of the acetabulum. An impaction device is provided that allows for impaction of the acetabular component with the hip reduced or articulated in order to fully seat a press fit acetabular component into the acetabulum. In hip arthroplasty, the hip is accessed through an incision adequate to expose the trochanteric fossa and allow resection of the femoral neck and removal of the femoral head and neck segment. The femoral canal is accessed through the trochanteric fossa and trochanteric region. Reamers, rasps and other devices as are known to those skilled in the art are used to prepare the proximal femur to receive a femoral implant by a sequence of reaming and broaching steps. Once prepared, the intramedullary canal and retained area of the femoral neck and trochanteric region are used to support the acetabular cup impactor of the current invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view of the surgical incision through which the present invention is structured to be used.
[0011] FIG. 2 is an orthogonal view of cup impactor according to embodiment of the present invention.
[0012] FIG. 3 is a perspective view of the acetabular cup impactor, femoral broach and acetabular cup superimposed on a femur according to embodiment of the present invention.
[0013] FIG. 4 is a schematic view of a femoral broach.
[0014] FIGS. 5 and 6 are exploded views of cup impactor according to embodiment of the present invention.
[0015] FIGS. 7, 8 and 9 are cross section views of implant attachment assembly according to embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] As described above, the present invention is applicable to orthopedic surgical procedures for total hip arthroplasty; optionally the invention may be used in resurfacing hip arthroplasty. Optionally, the cup impactor of this invention may be used with an attachable alignment guide to aid in aligning and orienting the acetabular shell. Optionally, the cup impactor of this invention may be used with an attachable surgical navigational tracker to aid in aligning and orienting the acetabular shell.
[0017] Referring to FIG. 1 , there is depicted a surgical incision 100 for a less invasive total hip arthroplasty. The muscles and soft tissues spanning the hip joint are exposed and either bluntly dissected along muscle fibers or separated along muscle boundaries. Optionally, select muscles may be taken down to increase surgical exposure and access to the hip joint. Anatomy of interest to this embodiment of the invention includes the pelvis 102 , the acetabulum 104 , the femur 106 , the joint capsule (not shown) and the muscles 105 and ligaments spanning the hip joint. The femoral head is resected at the base of the femoral neck 107 as shown in FIG. 1 to provide access to the medullary canal to prepare the canal to receive a femoral hip stem. In total hip arthroplasty, the articular surfaces of the proximal femur and the acetabulum are resurfaced. In general, after resecting the femoral head, the femur is prepared by reaming and broaching to prepare the femoral canal to receive a hip stem implant and femoral head implant there on. Alternatively, the femoral head may be sculpted to receive a resurfacing implant structured to fit over the prepared femoral head, this representing another embodiment of the present invention to place an implant onto a prepared bone surface. The acetabulum is generally prepared by reaming a hemispherical cavity to receive an acetabular cup.
[0018] In traditional total hip arthroplasty the surgical exposure generally ranges between eight and twelve inches in length and may result in extensive trauma to the soft tissues surrounding the hip joint. In minimally invasive total hip surgery, the incision 100 is typically two to four inches in length as shown in FIG. 1 . While this is a typical length for a minimally invasive surgical incision, there may be some variation due to patient physiology, surgeon preferences, and/or other factors. The surgical approach involves separating the gluteus maximus muscle through blunt dissection to gain access to the hip joint capsule and the trochanteric fossa. Muscle disruption is usually limited to release of the piriformis tendon at the trochanteric fossa. It should be noted that there are variations to the surgical approaches described that are known to someone skilled in the art.
[0019] Referring now to FIG. 2 , The impactor 1 having a first end and a second end. The first end having a strike plate 16 structured to receive mallet blows to impact acetabular shell 6 . The second end structure to receive acetabular shell 6 . Impactor 1 generally includes a handle 14 , a distraction assembly 44 , an implant attachment assembly 45 and a pressure input assembly 46 .
[0020] Handle 14 includes a handle shaft 24 having a grip 15 thereon, grip 15 being of a size and shape for grasping in a hand to stabilize impactor 1 . Strike plate 16 generally covers surface of handle 1 first end and is joined to handle shaft 24 such that mallet blows applied to strike plant 16 are transferred to handle shaft 24 . Implant attachment assembly 45 is joined to handle shaft 24 such that mallet blows applied to strike plate 16 are transferred to acetabular shell 6 . Referring to FIG. 6 , handle shaft 24 includes external thread 53 to threadably receive internal thread 54 of strike plate 16 .
[0021] Distraction assembly 44 includes a piston 8 and a piston extension 9 . Referring to FIGS. 2, 3 and 4 , piston 8 is structured to slidably broach post 110 . Broach 108 is supported within femur 2 . Distraction assembly 44 is structured to receive pressure input assembly 46 to provide pressure to elongate piston 8 and piston extension 9 as described in greater detail hereinafter. Syringe pump (not shown) or similar hydraulic or pneumatic pressure source connected to pressure input assembly 46 to pressurize distraction assembly 44 .
[0022] Implant attachment assembly 45 is structured to releasably receive acetabular shell 6 and includes latch 28 to activate lock to secure adaptor link 7 as described in greater detail hereinafter.
[0023] Pressure input assembly 46 includes Luer Lock 4 for sealable connection to syringe pump (not shown) and elongated tube 19 . Elongated tube 19 sealably received by distraction assembly 44 as described in greater detail hereinafter.
[0024] Turning now to FIG. 5 , second end of handle 1 is structured to slidably receive piston extension 9 therein retained by piston retainer 13 . Piston extension 9 is structured to slidably receive piston 8 . Distraction assembly 44 includes o-rings 10 , 11 and 12 sealing interfaces between piston 8 and piston extension 9 , piston extension 9 and piston retainer 13 , and piston retainer 13 and handle shaft 24 , respectively, as illustrated in cross section view in FIG. 7 . Piston retainer 13 is structured to slidably receive piston extension 9 and to be assembled into handle shaft 24 by threaded interface 47 .
[0025] Referring to FIGS. 5 and 8 , pressure input assembly includes attachment end 51 slidably and sealably received in receiving hole (not shown) in handle shaft 24 . The receiving hole is in communication with handle shaft cylinder 49 via port 52 , which is in communication with piston extension cylinder 49 .
[0026] Implant attachment assembly 45 , shown in cross section in FIGS. 6, 7 , 8 and 9 , includes adaptor link 7 structured to be slidably and lockably received by handle shaft 24 , and structured to be assembled with acetabular shell 6 . Implant attachment assembly 45 further includes latch 28 , safety lock 29 , lock spring 30 , latch spring 31 , and retaining pin 55 , each of which is assembled into handle shaft 24 .
[0027] Adaptor link 7 includes external thread 40 sized to be threadably received by threaded receiving hole 41 in acetabular shell 6 . Adaptor link 7 being one of a set of adaptor links (not shown) of various lengths as appropriate for the size range of acetabular shells typically included in a total hip implant kit. Optionally, adaptor link set (not shown) may include various thread 40 sizes as appropriate for assembly with acetabular shells generally available. Optionally, adaptor link set may include adaptor links structured for assembly with generally available acetabular shells structured with fasteners other than threaded fasteners, for example bayonet mounts, expanding collets, or snap fits.
[0028] Assembly of latch 28 , safety lock 29 , lock spring 30 , latch spring 31 , retaining pin 55 and handle shaft 24 is as follows. Latch spring 31 is placed into receiving hole 60 . Lock spring 30 is placed into receiving hole 61 . Safety lock 29 is slidably received in slot 67 retained therein by tabs 66 slidably received in grooves 65 and by latch 28 . Latch 28 is slidably received in slot 59 and slidably retained by retaining pins 55 placed into upper receiving hole 57 and lower receiving hole 58 in handle shaft 24 . Retaining pins 55 secured in place by welding, bonding, press fit, or other suitable means know to those skilled in the art. Retaining pins 55 slidably received in upper receiving slot 34 and lower receiving slot 35 in latch 28 . Latch 28 thus assembled is free to slide up and down by force applied by the operator to release button 56 . In an unlocked position, shown in FIG. 8 , latch 28 is depressed into handle shaft 24 and retained therein by safety lock 29 tab 64 resting on latch 28 surface 68 . Sliding safety lock 29 away from latch 28 releases latch 28 to slide upward to a locked position. Tab 64 engages latch 28 slot 63 thereby retaining latch in locked position. The top face of safety lock 29 tab 64 is ramped to allow slidable release of safety lock 29 by pressing on release button 56 thereby moving the latch to unlocked position. Latch spring 31 provides bias force tending to move latch 28 towards a locked position. Lock spring 30 provides bias force tending to move safety lock 29 towards engagement with latch 28 .
[0029] Turning now to connecting an acetabular shell 6 to impactor 1 , handle 14 second end 71 is generally cylindrical with radius leading edge and includes six bayonet slots 21 circumferentially equally spaced. Optionally, one or more bayonet slots 21 may be used or other fasteners, for example threaded fastener, slip fit, taper fit, snap fit, etc., know to those skilled in the art. Adaptor link 7 cavity 70 is structured to slidably receive handle 14 second end 71 and releasably lock thereon. Cavity 70 including six tabs 69 circumferentially equally spaced to be received by corresponding bayonet slots 21 . Lower end of latch 28 includes a tab 33 positioned to close off one of the bayonet slots 21 . Latch 28 unlocked position, as shown in FIG. 8 , positions tab 33 deeper than bayonet slot 21 opening. Latch 28 locked position, as shown in FIG. 9 , positions tab 33 within bayonet slot 21 opening to block one adaptor link 7 tab 69 from turning out of bayonet slot 21 .
[0030] Adaptor link 7 is first assembled with acetabular shell 6 . With latch 28 in unlocked position, adaptor link 7 is slidably received on handle 14 second end 71 and rotated to secure tabs 69 in bayonet slots 21 . Safety lock 29 is slid away from latch 28 to release latch 28 to locked position.
[0031] Distraction assembly 44 is initially retracted as shown in FIG. 9 . Pressure, either hydraulic or pneumatic, applied to pressure input assembly 46 deploys piston 8 and piston extension 9 to tension the joint capsule as described in more detail hereinafter. Distraction assembly 44 is shown in full distraction position in FIG. 7 . Strike plate 16 , shaft handle 24 , adaptor link 7 , piston 8 and extension piston 9 are constructed of rigid material, such as metal or carbon-carbon composite, to withstand mallet blows typical of impacting an acetabular shell. Grip 15 is constructed of metal or plastic or laminated linen material as is know by those skilled in the art.
[0032] As shown most clearly in FIG. 3 , handle shaft 24 angles abruptly, generally perpendicular, away from acetabular shell 6 axis. Optionally, handle shaft 24 may angle more acutely away from acetabular shell 6 axis in a range from 45° to 90°. Curved portion 72 of handle shaft 24 is structured for co-axial alignment of acetabular shell axis, grip 15 and strike plate 16 . Curve portion 72 sized and shaped to provide clearance around anatomical features of hip joint and surrounding tissues. Such abrupt angulation of shaft handle 24 is advantageous when performing hip surgery through a limited or minimal exposure as the muscles spanning the hip are preferably left intact thereby limiting the space outside of the acetabulum.
[0033] The current invention is designed to provide alignment and orientation of the acetabular shell based on the anatomy of the pelvis, femur and on the kinematics of the hip joint. This is accomplished by tissue guided surgery “TGS” as described in patents U.S. Pat. No. 6,723,102 and patent applications US 2002/0193797 and US 2003/0236523, the entireties of which are incorporated by reference. Impactor 1 is designed to attach to a femoral broach 3 supported by femur 2 . In applying TGS to hip arthroplasty, orientation of acetabular shell 6 is guided by soft tissue envelope surrounding the hip joint. This envelope of tissue defines the limits of hip motion. The soft tissue capsule working in combination with muscles spanning the hip and the articular joint surfaces of the hip define hip kinematics. TGS utilizes such kinematics to first prepare the acetabulum, then to orient and place acetabular shell 6 . Femur 2 is used as a reference to guide impactor 1 to orient acetabular shell 6 relative to acetabulum by using the joint capsule to properly position and orient the femur with respect to the acetabulum.
[0034] Surgical Procedure
[0035] Impactor 1 is structured for partially disassembled for cleaning and sterilization. The components of the impactor are housed in an instrument tray which is brought to the operating room sterile. The instrument tray has fixtures to hold individual components and markings to show where components are to be placed. Impactor 1 is assembled in the operating room under sterile conditions. Distraction assembly 44 is fully retracted. A syringe pump (not shown) or suitable sterile fluid pressurizing source is charged with sterile saline and attached to pressure input assembly 46 .
[0036] After reaming the acetabulum and with the femoral broach in place, the appropriate size acetabular shell 6 is selected. The corresponding adaptor link 7 is selected and assembled to the shell 6 . The adaptor link 7 is attached to handle shaft 24 as described above.
[0037] Impactor 1 with acetabular shell 6 attached is used to place the shell 6 into the prepared acetabulum. Acetabular shell 6 is oriented with respect to the acetabulum by properly aligning the femur with the pelvis then deploying distraction assembly 44 as previously described to tensioning joint capsule. Cup alignment may be confirmed with a mechanical alignment guide (not shown) or with a surgical navigation system and tracker (not shown).
[0038] Acetabular shell 6 is now in proper position and orientation with respect to the acetabulum. The surgeon uses a mallet (not shown) to impact acetabular shell 6 by striking the strike plate 16 . Mallet blows are repeated until acetabular shell 6 is fully seated in the acetabulum. Distraction assembly 44 is retracted. Handle shaft 24 is released from adaptor link 7 as described above and removed from surgical site. Adaptor link 7 is removed from acetabular shell 6 using a hex driver (not shown) attaching to the hex drive 39 . The cup is now placed in the acetabulum and the total hip arthroplasty procedure continues per the surgical technique.
[0039] While a preferred embodiment of the present invention has been described, it should be understood that various changes, adaptations and modifications may be made therein without departing from the spirit of the invention and the scope of the appended claims. | A method and apparatus for minimally invasive total joint replacement. The method involves sculpting the articular surface of a second bone that normally articulates with a first bone by attaching a bone sculpting tool directly or indirectly to the first bone with the tool in bone sculpting engagement with the articular surface of the second bone, and then sculpting the articular surface of the second bone with the joint reduced and moving one bone with respect to the other. An implant is placed to replace the articular surface of the second bone using an impaction device directly or indirectly attached to the first bone. | 0 |
FIELD OF THE INVENTION
The present invention relates to systems for distributing and playing digitized audiovisual signals and, in particular, to a mechanism for distributing and playing such digitized audiovisual signals such that unauthorized copying of such signals is discouraged to thereby protect intellectual property rights of artists.
BACKGROUND OF THE INVENTION
Recent advances in lossless compression of digitized audio signals and storage capacity has recently led to the development of music players which play CD-quality music stored in solidstate memory. For example, a number of MP3 players are available into which a user can download compressed, CD-quality digitized audio signals into solid-state memory for subsequent playback. “MP3” generally refers to the MP3 format which is the MPEG standard for audio coding (MPEG-1 Video, Layer 3 Audio, ISO Standard #1172-3). The MP3 format provides excellent sound quality at a data rate of 128 Kbits (44 KHz, 16-bit samples, stereo).
While MP3 players provide very good sound quality and great convenience for the user, MP3 players provide essentially no protection whatsoever against unauthorized copying of copyrighted works. Currently, a number of computer systems provide free access to copyrighted musical works through the Internet. A user who is in possession of a digitized, copyrighted music signal in the MP3 format can, albeit most likely in violation of copyright laws, distribute unlimited identical digital copies of the music signal to friends with no compensation whatsoever to the copyright holder. Each such copy suffers no loss of quality from the original digitized music signal.
A few attempts have been made to thwart the unauthorized proliferation of perfect digital copies of digitized audiovisual signals. One such technique is used in minidisc and digital audio tape (DAT) devices. To allow transfer of previously purchased digitized audio signals, one digital-to-digital copy is permitted. In other words, digital copies of digital copies is prevented. Typically, a single bit in the storage medium indicates whether the stored signal is a digital copy. If content is written to the storage medium—e.g., either a minidisc or a DAT tape—through a digital port in a player/recorder, the bit is set to indicate that the content of the medium is a digital copy. Otherwise, the bit is cleared to indicate either an analog copy—content recorded through an analog port of the player/recorder—or that the content is an original recording, e.g., through a microphone.
This form of copy protection is insufficiently restrictive. For example, an owner of an audio DAT can distribute at least one unauthorized copy to another person. In addition, unlimited digital copies of a CD can be made onto minidiscs or DATs although each of those digital copies cannot be digitally copied. This form of copy protection can also be excessively restrictive, preventing an owner of a prerecorded audio medium to make copies for each of a number of players of the prerecorded audio owner, namely, players in the home, office, car, and for portable use.
As alluded to briefly above, the single-copy mechanism fails to prevent any copying of digital read-only media such as CDs. The content of such media is typically uncompressed and un-obscured such that unauthorized copying is unimpeded.
What is needed is a mechanism by which copyrightable content of digital storage media is protected against unauthorized copying while affording the owner of such digital storage reasonable unimpeded convenience of use and enjoyment of the content.
SUMMARY OF THE INVENTION
In accordance with the present invention, data such as a musical track is stored as a secure portable track (SPT) which can be bound to one or more specific external players and can be bound to the particular storage medium in which the SPT is stored. Such restricts playback of the SPT to the specific external players and ensures that playback is only from the original storage medium. Such inhibits unauthorized copying of the SPT.
The SPT is bound to an external player by encrypting data representing the substantive content of the SPT using a storage key which is unique to the external player, is difficult to change (i.e., is read-only), and is held in strict secrecy by the external player. Specifically, the data is encrypted using a master media key and the master media key is encrypted using the storage key. Since only the external player knows the storage key, the master media key is passed to the external player using a secure communication session and the external player encrypts the master media key using the storage key and returns the encrypted master media key. Accordingly, only the specific external player can decrypt the master media key and, therefore, the data representing the substantive content of the SPT.
The SPT is bound to a particular piece of storage medium by including data uniquely identifying the storage medium in a tamper-resistant form, e.g., cryptographically signed. The medium identification data is difficult to change, i.e., read-only. Prior to playback of the SPT, the external player confirms that the media identification data has not been tampered with and properly identifies the storage medium.
The SPT can also be bound to the storage medium by embedding logic circuitry, e.g., integrated circuitry, in the packaging of the storage medium for performing cryptographic processing. The SPT is bound by encrypting the master media key, which is used to encrypt the data representing the substantive content of the SPT, using the embedded logic. By using unique cryptographic logic in the packaging of the storage medium, only that particular storage medium can decrypt the master media key and, therefore, the substantive content of the SPT.
To allow a user to playback the SPT on a number of players, e.g., one in the home, one in the office, one in the car, etc., external players can share storage keys with one another. However, such key sharing must be done in a cryptographically secure manner to prevent crackers from attempting to collect storage keys from external players.
The two external players communicate with one another in a cryptographically secure session. One, the initiator, sends a request message which includes a certificate of the initiator and a first random number. The other, i.e., the responder, authenticates the initiator using the certificate and responds with a reply message. The reply message includes the certificate of the responder, the first random number, a second random number, and one or more storage keys of the responder encrypted with a public key of the initiator. The initiator authenticates the responder using the certificate and responds with an exchange message. The exchange message includes the first and second random numbers and one or more storage keys of the initiator encrypted with a public key of the responder. Thus, each has copies of the other's storage keys and can play SPTs bound to the other external player.
Before downloading an SPT to a particular external player, the ability of the external player to enforce restrictions placed upon the SPT is verified. During a registration process, the external player identifies those types of restrictions which can be enforced by the external player. Such types include a maximum number of times an SPT is played, an expiration time beyond which the SPT can no longer be played, and a number of copies of the SPT which can be made. For each type of restriction imposed upon a particular SPT, the external player is verified to be able to enforce that particular type of restriction,. If the external player is unable to enforce any of the restrictions imposed upon the SPT, downloading and/or binding of the SPT to the external player is refused. Otherwise, downloading and/or binding is permitted.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a computer system which includes a player, secure portable tracks, and an interface for an external player in accordance with the present invention.
FIG. 2 is a block diagram of the interface and external player of FIG. 1 showing a storage medium for the secure portable track in greater detail.
FIG. 3 is a block diagram of the format of a secure portable track in greater detail.
FIG. 4 is a block diagram illustrating bindings in the header of the secure portable track of FIG. 3 in accordance with the present invention.
FIG. 5 is a block diagram of two external players in accordance with the present invention in greater detail.
FIG. 6 is a logic flow diagram of the encoding of content to bind the content to an external player and medium in accordance with the present invention.
FIG. 7 is a logic flow diagram of the decoding of content to enforce a binding of the content to an external player and medium in accordance with the present invention.
FIG. 8 is a logic flow diagram of the exchange of keys between the two external players shown in FIG. 5 in accordance with the present invention.
FIG. 9 is a block diagram illustrating restrictions in the header of the secure portable track of FIG. 3 in accordance with the present invention.
FIG. 10 is a logic flow diagram illustrating the assurance of an external player's ability to enforce restrictions in accordance with the present invention.
FIG. 11 is a block diagram of the interface and external player of FIG. 1 showing a storage medium for the secure portable track in greater detail.
FIG. 12 is a logic flow diagram of the encoding of content to bind the content to a storage medium in accordance with the present invention.
FIG. 13 is a logic flow diagram of the decoding of content to enforce a binding of the content to a storage medium in accordance with the present invention.
DETAILED DESCRIPTION
In accordance with the present invention, data such as a musical track is stored as a secure portable track (SPT) which can be bound to one or more specific external players and can be bound to the particular storage medium in which the SPT is stored. Such restricts playback of the SPT to the specific external players and ensures that playback is only from the original storage medium. Such inhibits unauthorized copying of the SPT.
A brief overview of the operating environment of the secure portable music playing system according to the present invention facilitates appreciation and understanding of the present invention. Computer system 100 (FIG. 1) has a typical architecture. Computer system 100 includes a processor 102 and memory 104 which is coupled to processor 102 through an interconnect 106 . Interconnect 106 can be generally any interconnect mechanism for computer system components and can be, e.g., a bus, a crossbar, a mesh, a torus, or a hypercube. Processor 102 fetches from memory 104 computer instructions and executes the fetched computer instructions. Processor 102 also reads data from and writes data to memory 104 and sends data and control signals through interconnect 106 to one or more computer display devices 120 and receives data and control signals through interconnect 106 from one or more computer user input devices 130 in accordance with fetched and executed computer instructions.
Memory 104 can include any type of computer memory and can include, without limitation, randomly accessible memory (RAM), read-only memory (ROM), and fixed and removable storage devices which include storage media such as magnetic and/or optical disks. Memory 104 includes a music player 110 which includes a secure portable track (SPT) interface 114 and which is all or part of one or more computer processes which in turn execute within processor 102 from memory 104 . A computer process is generally a collection of computer instructions and data which collectively define a task performed by a computer system such as computer system 100 . Thus, when a computer process, such as player 110 , takes a particular action, in reality processor 102 executes computer instructions of the computer process and execution of those computer instructions causes the particular action to be taken.
Each of computer display devices 120 can be any type of computer display device including without limitation a printer, a cathode ray tube (CRT), a light-emitting diode (LED) display, or a liquid crystal display (LCD). Each of computer display devices 120 receives from processor 102 control signals and data and, in response to such control signals, displays the received data. Computer display devices 120 , and the control thereof by processor 102 , are conventional.
Each of user input devices 130 can be any type of user input device including, without limitation, a keyboard, a numeric keypad, or a pointing device such as an electronic mouse, trackball, lightpen, touch-sensitive pad, digitizing tablet, thumb wheels, or joystick. Each of user input devices 130 generates signals in response to physical manipulation by the listener and transmits those signals through interconnect 106 to processor 102 .
Input/output (I/O) port 140 receives control signals from processor 102 through interconnect and, in response to the control signals, receives data from and sends data to processor 102 . In addition, I/O port 140 sends data to and receives data from a device which can be coupled to I/O port 140 . In this embodiment, a secure portable music player 150 is coupled to I/O port 140 . I/O port 140 can be, for example, a serial port or a parallel port. Secure portable music player 150 is sometimes referred to herein as portable player 150 .
Network access circuitry 160 couples computer system 100 to a computer network 170 which can be, for example, an intranet or internet. Network access circuitry 160 implements data transfer protocols between interconnect 106 and computer network 170 and can be, for example, a modem or ethernet circuitry.
Briefly, player 110 receives musical tracks 112 and associated data through computer network 170 in a manner described more completely in U.S. patent application Ser. No. 09/020,025 filed Feb. 6, 1998 entitled “Secure Online Music Distribution System” by Philip R. Wiser, Andrew R. Cherenson, Steven T. Ansell, and Susan A. Canon which is incorporated herein in its entirety by reference. Accordingly, tracks 112 are stored in an encrypted format in which only player 110 can decrypt tracks 112 for playback of the substantive content of tracks 112 . SPT interface 114 creates secure portable tracks (SPTs) 116 from tracks 112 and downloads SPTs 116 to portable player 150 . While the substantive content of tracks 112 and SPTs 116 is described in this illustrative embodiment as music, it is appreciated that many of the techniques and mechanisms described herein are equally applicable to other forms of data for which unauthorized copying is to be thwarted. Examples of such content includes, for example, still graphical images, motion video, and computer software.
In accordance with the present invention, SPTs 116 are bound both to storage medium 202 (FIG. 2) in which SPTs 116 are stored within portable player 150 and to one or more specific external players, e.g., portable player 150 . For example, storage medium 202 is a removable digital storage medium such as a recordable compact disc (CD-R), a minidisc, a digital video disc (DVD), digital audio tape (DAT), flash memory card, or similar removable digital storage medium. In addition, portable player 150 can include sufficient storage to store a number of SPTs 116 which can be directly downloaded into portable player 150 , obviating removable digital storage media such as storage medium 202 . However, it is desirable to permit playback of content of SPTs 116 in less-portable external players such as high-quality component players of home stereo systems and dash-mounted players installed in cars and other vehicles. Accordingly, removable storage media such as storage medium 202 is preferred to storage directly within portable player 150 . External players are playback devices which can operate while detached from computer system 100 (FIG. 1 ).
Binding SPTs 116 to storage medium 202 (FIG. 2) renders SPTs 116 unplayable when copied to a different storage medium. Similarly, binding SPTs 116 to a number of external players, including portable player 150 , makes SPTs 116 unplayable in external players other than the external players to which SPTs 116 are bound. Accordingly, copying of SPTs 116 is inhibited.
Understanding the manner in which SPTs 116 are bound to storage medium 202 and portable player 150 is facilitated by a brief description of the format of SPTs 116 . An illustrative one of SPTs 116 is shown in greater detail in FIG. 3 . SPT 116 includes a header 302 which in turn includes a number of bindings as described more completely below and a reference to a table of contents 306 . In one embodiment, table of contents 306 is the last component of SPT 116 . In such an embodiment, table of contents 306 can be formed as images 304 A-C are appended to SPT 116 during creation and can be appended to SPT 116 after all images are included in SPT 116 and table of contents 306 is complete. Each of images 304 A-C are discrete components of SPT 116 and can have a different structure. Each image of SPT 116 is represented by and is accessible through one of descriptors 308 A-D of table of contents 306 . All images of SPT 116 collectively represent the substantive content of SPT 116 , e.g., digitally represented music.
Header 302 includes a number of bindings 400 (FIG. 4 ), each of which binds the content of SPT 116 (FIG. 2) to both (i) storage medium 202 and (ii) a particular external player such as portable player 150 . Each of bindings 400 includes the following fields, each of which stores data representing a component of the binding: (i) media identification field 402 , (ii) media type and information field 404 , (iii) storage key identification field 406 , (iv) encrypted media master key 408 , and (v) binding message authentication code (MAC) field 410 .
Media identification field 402 stores data representing a read-only serial number 204 (FIG. 2) of storage medium 202 . Serial number 204 is “read-only” in that alteration of the particular value of serial number 204 is difficult. For example, serial number 204 can be stored in a portion of storage medium 202 which cannot be overwritten or can be represented in semiconductor circuitry included in storage medium 202 . It is appreciated that serial number 204 can never be completely protected from alteration by particularly industrious and persistent crackers. However, serial number 204 should not be alterable by straightforward data writing access to storage medium 202 .
Media type and information field 404 (FIG. 4) stores data representing the type of storage medium 202 (FIG. 2 ). Such permits comparison of the indicated type with the actual type of storage medium 202 . For example, if media type and information field 404 (FIG. 4) indicates that storage medium 202 (FIG. 2) is a DVD and portable player 150 determines that storage medium 202 is a flash memory card, portable player 150 can readily reject storage medium 202 as an invalid copy.
Storage key identification field 406 stores data identifying the storage key, i.e., the key with which the master media key is encrypted. The master media key is the key with which the substantive content of SPT 116 is encrypted. To bind SPT 116 to a particular external player, e.g., portable player 150 , the storage key is a key which is maintained in secrecy and is allocated to the specific external player. An example of such a storage key is read-only key 504 A (FIG. 5) of portable player 150 . Read-only key 504 A is analogous to serial number 204 (FIG. 2) of storage medium 202 in that read-only key 504 A is difficult to change, typically requiring physical deconstruction of portable player 150 . For example, read-only key 504 A can be embedded in the internal semiconductor circuitry of portably player 150 . In one embodiment, read-only key 504 A includes three (3) separate keys: one which is never shared with other external players, one which can be shared with other external players, and one which is common to all external players. By selecting a specific one of these keys as the storage key, player 110 and SPT interface 114 can select a desired level of security of the substantive content of SPT 116 .
Storage key identification field 406 (FIG. 4) stores a digest of the storage key to identify the storage key without recording the storage key itself within SPT 116 .
Encrypted media master key field 408 (FIG. 4) stores data representing an encrypted representation of the key by which the content of SPT 116 (FIG. 3 ), e.g., images 304 A-C, is encrypted. The media master key is encrypted to prevent unauthorized decryption of the content of SPT 116 .
Binding MAC field 410 (FIG. 4) stores data representing a message authentication code (MAC) of fields 402 - 408 and therefore provides protection against tampering with the contents of field 402 - 408 by a cracker attempting to gain unauthorized access to the content of SPT 116 . MACs are conventional and known and are not described further herein.
Logic flow diagram 600 (FIG. 6) illustrates the preparation of SPT 116 (FIG. 1) from one or more of tracks 110 by player 110 through SPT interface 114 for playback by portable player 150 . In step 602 (FIG. 6 ), player 110 (FIG. 1) encrypts the content of one or more of tracks 110 using, for example, symmetric key encryption. Symmetric key encryption of the content is used in this illustrative embodiment to facilitate decryption by portable player 150 with sufficient efficiency to permit uninterrupted playback of CD-quality music while simultaneously leaving sufficient processing resources within portable player 150 for decompression of compressed audio data and permitting use of relatively inexpensive components within portable player 150 with limited processing power to thereby minimize the cost of portable player 150 to consumers.
The master media key is encrypted using the storage key of the particular external player to which SPT 116 is to be bound. To avoid divulging the storage key to player 110 , the particular external player, rather than player 110 , encrypts the master media key. Thus, in step 604 (FIG. 6 ), player 110 (FIG. 1) encrypts the media master key using a session key formed at the onset of a secure communication session between player 110 and portable player 150 and sends the encrypted master media key to portable player 150 . Portable player 150 decrypts the master media key and re-encrypts the master media key using the storage key, e.g., read-only key 504 A and sends the encrypted master media key back to player 110 . As a result, only portable player can decrypt the encrypted master media key and therefore the content of SPT 116 . Preparation of multiple bindings is described below in greater detail. Session keys are formed using a communication key of portable player 150 which, like read-only key 504 A, is difficult to change and which is held in secrecy by portable player 150 . However, for the purposes of carrying out secure communication, portable player 150 communicates the communication key to player 110 during a one-time registration which is described more completely below. The use of a communication separate from the storage key serves to protect the secrecy of the storage key.
Since the master media key is encrypted using read-only key 504 A, the master media key—and therefore the content of SPT 116 which is encrypted with the master media key—can only be decrypted using read-only key 504 A. By carefully guarding the secrecy of read-only key 504 A, SPT 116 is bound to portable player 150 and can only be played back by portable player 150 or by any external player with which portable player has shared keys. A mechanism by which external players can share read-only keys in a secure manner is described below in greater detail.
In step 606 (FIG. 6 ), player 110 (FIG. 1) forms a digest of the storage key, e.g., read-only key 504 A (FIG. 5 ), to produce storage key identification data.
In step 608 (FIG. 6 ), player 110 (FIG. 1) forms SPT 116 , stores the encrypted content in SPT 116 , and forms binding 400 (FIG. 4) within header 302 of SPT 116 . Player 110 (FIG. 1) forms binding 400 (FIG. 4) by (i) storing serial number 204 (FIG. 2) in media identification field 402 (FIG. 4 ), (ii) storing data representing the type of storage medium 202 (FIG. 2) in media type and information field 404 (FIG. 4 ), (iii), storing the digest formed in step 606 (FIG. 6) in storage key identification field 406 (FIG. 4 ), (iv) storing the encrypted media master key formed in step 604 (FIG. 6) in encrypted media master key field 408 (FIG. 4 ), and (v) forming and storing in binding MAC field 410 (FIG. 4) a MAC of fields 402 - 408 .
Player 110 (FIG. 1) can bind SPT 116 to multiple external players by forming a separate binding 400 for each such external player. For each such binding, player 110 repeats steps 604 - 606 and step 608 except that the encrypted content is included in SPT 116 only once. Thus, there is only one media master key by which the content is encrypted but each of bindings 400 stores a different encryption of media master key.
The security afforded by such binding is more fully appreciated in the context of decoding for playback by portable player 150 as illustrated by logic flow diagram 700 (FIG. 7 ). In the context of logic flow diagram 700 , storage media 202 (FIG. 5) is installed in portable player 150 such that SPTs 116 are accessible to portable player 150 . Portable player 150 includes player logic 502 A which includes circuitry and/or computer software to implement the functions performed by portable player 150 . To playback a selected one of SPTs 116 , player logic 502 A reads SPT 116 and parses header 302 (FIG. 3) therefrom and parses bindings 400 (FIG. 4) from header 302 .
In test step 702 (FIG. 7 ), player logic 502 A (FIG. 5) retrieves read-only serial number 204 from storage media 202 and media identification data from media identification field 402 (FIG. 4) and compares read-only serial number 204 to the media identification data. If read-only serial number 204 and the media identification data are not equivalent, player logic 502 A (FIG. 5) aborts playback of SPT 116 . Accordingly, simple copying of SPT 116 from storage medium 202 to another storage media renders SPT 116 unplayable. If read-only serial number 204 and the media identification data are equivalent, processing transfers to step 704 .
In step 704 (FIG. 7 ), player logic 502 A (FIG. 5) selects either read-only key 504 A or a selected one of keys 506 A 1 - 4 according to the digest stored in storage key field 406 (FIG. 4 ). As described more completely below, portable player 150 can share keys with other external players. Keys 506 A 1 - 4 store read-only keys shared by other external players. The sharing of keys permits a single user to play content on a number of external players, e.g., a home player, a portable player, a player in a car, and a player at the office. In addition, read-only key 504 A can include a number of individual component keys in one embodiment. Each such component key is considered by player logic 502 A as a separate key in step 702 (FIG. 7 ).
To select the appropriate key, player logic 502 A forms respective digests of each component key of read-only key 504 A and each of keys 506 A 1 - 4 using the same algorithm employed by player 110 (FIG. 1) in step 606 (FIG. 6) and selects the one of keys 504 A, 506 A 1 - 4 whose digest is accurately represented in storage key identification field 406 (FIG. 4 ). If no digest is accurately represented in storage key field 406 (FIG. 4 ), player logic 502 A aborts playback and presents an error message to the user. Failure of the respective digests to be accurately represented in storage key field 406 indicates that portable player 150 (FIG. 5) does not include the storage key used by player 110 (FIG. 1) in step 604 (FIG. 6 ). Accordingly, recovery of the master media key and therefore the content of SPT 116 is not possible.
In step 706 (FIG. 7 ), player logic 502 A (FIG. 5) decrypts the media master key from encrypted media master key field 408 (FIG. 4) using the key selected in step 704 (FIG. 7 ). In step 708 , player logic 502 A (FIG. 5) decrypts the content of SPT 116 using the decrypted media master key. After step 708 , the content of SPT 116 is un-encrypted and is available for decompression and playback by player logic 502 A. Decompression and playback of the unencrypted content is conventional.
Key Sharing
Frequently, a user will have multiple external players—e.g., a portable player such as portable player 150 , a full-featured player as a component of a home stereo system, a dash-mounted player in a car, and perhaps a player at the user's place of work. Typically, the user would like to play a particular purchased track, e.g., SPT 116 , on all of her external players. Since SPT 116 is bound to portable player 150 according to read-only key 504 A, any external player with a copy of read-only key 504 A can also play SPT 116 . Therefore, to play SPT 116 on multiple external players, each such external player must have exchanged keys, either directly or indirectly, with portable player 150 .
In addition to portable player 150 , FIG. 5 shows a second external player 150 B. External player 150 B can be any of the various types of external players described above, including a second portable player. The components of portable player 150 and external player 150 B are analogous to one another as shown in FIG. 5 . Communication logic and ports 512 A-B include hardware and software to communicate with other devices such as I/O port 140 and/or other external players. In one embodiment, communication logic and ports (CLPs) 512 A-B are coupled directly to one another through a connector 520 and communicate directly with one another. Connector 502 can be, for example, a cable between communication logic and ports 512 A-B. Alternatively, connector 502 can be light signals between communication logic and ports 512 A-B which can include infrared LEDs and infrared light sensors. In an alternative embodiment, communication logic and ports 512 A-B communicate only with an I/O port of a computer such as I/O port 140 of computer system 100 . In the latter embodiment, computer system 100 includes at least two I/O ports such as I/O port 140 and both external players are coupled to computer system 100 such that SPT interface 114 acts as an intermediary to act as connector 520 between the external players. In an alternative variation of this latter embodiment, computer system 100 can have only a single I/O port 140 and SPT interface can act as a surrogate, exchanging keys with a single external player at a time and acting as a key repository. In this last embodiment, it is important that the keys stored within SPT interface 114 be stored in an encrypted form to prevent passing of the device keys to an unlimited number of external players. Such would be a serious compromise of the copy protection provided, relying more completely media binding for copy protection.
Logic flow diagram 800 (FIG. 8) illustrates a key exchange conducted between portable player 150 and external player 150 B. In the embodiment in which SPT interface 140 (FIG. 1) acts as a surrogate external player and a key repository, SPT 140 performs a separate key exchange with each of portable player 150 and external player 150 B in the manner described. The key exchange of logic flow diagram 800 (FIG. 8) is initiated by either of portable player 150 and external player 150 B, perhaps in response . In this illustrative embodiment, portable player 150 initiates the key exchange.
In step 802 (FIG. 8 ), CLP 512 A initiates the key exchange by sending a key exchange request message which includes certificate 508 A of portable player 150 and a first random number. The first random number is included to add variety to session encryption keys in a known and conventional manner to frustrate attempts of malicious and ill-tempered computer processes to masquerade as either of players 150 and 150 B having eavesdropped upon the dialogue between players 150 and 150 B in hopes of gaining unauthorized access to read-only keys 504 A and/or 504 B. Certificates are known and are not described further herein except to note that certificate 508 A can be used to authenticate portable player 150 and conveys the public key of key pair 510 A of portable player 150 . Similarly, certificate 508 B can be used to authenticate external player 150 B and conveys the public key of key pair 510 B of external player 150 B. Public/private key encryption/decryption is well-known and is not described further herein.
The key exchange initiate message is received by CLP 512 B in step 852 (FIG. 8 ). In step 854 , CLP 512 B (FIG. 5) encrypts read-only key 504 B and any of keys 506 B 1 - 4 which have been acquired through previous key exchanges. In the embodiment in which read-only keys 504 A-B include multiple individual keys, CLP 512 B includes only those keys of read-only key 504 B to which portable player 150 is permitted access. CLP 512 B encrypts the keys using the public key of portable player 150 parsed from the certificate in the key exchange initiate message. Accordingly, the keys can only be decrypted by CLP 512 A. CLP 512 B prepares a reply message in step 856 (FIG. 8 ). The reply message includes the encrypted keys, the first random number, a second random number, and certificate 508 B (FIG. 5 ). The second random number adds to the variety of session keys to further frustrate attempts to gain information through eavesdropping upon the dialogue between players 150 and 150 B. In step 858 (FIG. 8 ), CLP 512 B (FIG. 5) cryptographically signs the reply message using the public key of key pair 510 B and adds the signature to the reply message.
In step 860 (FIG. 8 ), CLP 512 B sends the reply message to CLP 512 A which receives the reply message in step 804 (FIG. 8 ). In step 806 , CLP 512 A (FIG. 5) verifies the signature of the reply message using the public key of key pair 510 B from certificate 508 B. CLP 512 A encrypts read-only key 504 A and any of keys 506 A 1 - 4 which have been acquired through previous key exchanges in step 808 (FIG. 8 ). In the embodiment in which read-only keys 504 AB include multiple individual keys, CLP 512 A includes only those keys of read-only key 504 A to which external player 150 B is permitted access. CLP 512 A (FIG. 5) encrypts the keys using the public key of external player 150 B parsed from the certificate in the reply message. Accordingly, the keys can only be decrypted by CLP 512 B. CLP 512 A prepares an exchange message in step 810 (FIG. 8 ). The exchange message includes the encrypted keys, the first random number, and the second random number. In step 812 (FIG. 8 ), CLP 512 A (FIG. 5) cryptographically signs the exchange message using the public key of key pair 510 A and adds the signature to the exchange message.
In step 814 (FIG. 8 ), CLP 512 A sends the exchange message to CLP 512 B which is received by CLP 512 B in step 862 (FIG. 8 ). In step 864 , CLP 512 B (FIG. 5) verifies the signature of the exchange message using the public key of key pair 510 A. The signatures of the reply and exchange messages serve to further cross-authenticate portable player 150 and external player 150 B.
To terminate the transaction, CLP 512 B sends a terminate message in step 866 (FIG. 8) which, in step 816 , is received by CLP 512 A (FIG. 5 ). Steps 868 (FIG. 8) and 870 are directly analogous to steps 818 and 820 , respectively. Accordingly, the following description of steps 818 and 820 is equally applicable to steps 868 and 870 , respectively.
In step 818 , CLP 512 A (FIG. 5) decrypts the encrypted keys using the private key of key pair 510 A. At this point, portable player 150 has all the keys of external player 150 B. In step 820 (FIG. 8 ), portable player 150 stores the decrypted keys in previously unused ones of keys 506 A 1 - 4 , discarding decrypted keys already represented in keys 506 A 1 - 4 and discarding keys when all of keys 506 A 1 - 4 are used. While only four keys 506 A 1 - 4 are shown for simplicity, more keys can be included in portable player 150 , e.g., 256 or 1,024 keys.
Thus, as shown in logic flow diagram 800 (FIG. 8 ), portable player 150 and external player 150 B exchange keys such that any SPT, e.g., SPT 116 , bound to either of portable player 150 and external player 150 B can be played by the other. Such only requires a one-time key exchange when a new external player is acquired by a particular user.
Enforcement of Restrictions on SPT 116
Tracks 112 can have restrictions placed upon them by player 110 (FIG. 1) and, indirectly, by a server from which player 110 acquires tracks 112 . Any such restrictions are included in SPTs 116 . Such restrictions are represented in header 302 which is shown in greater detail in FIG. 9 . Header can include a number of restrictions 902 , each of which includes a restriction type field 904 , a restriction data field 906 , and a restriction state 908 .
Restriction type field 904 stores data specifying a type of restriction on playback of SPT 116 (FIG. 3 ). Such restriction types can include, for example, the number of times SPT 116 can be played back, an expiration time beyond which SPT 116 cannot be played back, a number of storage media such as storage medium 202 (FIG. 2) on which SPT 116 can be fixed, and the number of devices to which SPT 116 can be bound.
Restriction data field 906 (FIG. 9) stores data specifying type-specific data to specify more particularly the restriction placed upon SPT 116 . For example, if the restriction type is a number of times SPT 116 can be played back, restriction data field 906 specifies the number. If the restriction type is an expiration time beyond which SPT 116 cannot be played back, restriction data field 906 specifies the time. If the restriction type is a number of storage media such as storage medium 202 (FIG. 2) on which SPT 116 can be fixed, restriction data field 906 specifies the number. And, if the restriction type is a number of devices to which SPT 116 can be bound, restriction data field 906 specifies the number.
Restriction state field 908 (FIG. 9) stores data specifying the current state of the restriction. For example, if the restriction type is a number of times SPT 116 can be played back, restriction state field 908 stores the number of times SPT 116 has been played back to date. Restriction state 908 allows SPT 116 to be passed between a couple of external players which can both enforce restriction 902 .
Player 110 (FIG. 1) and SPT interface 114 rely largely upon portable player 150 , and player logic 502 A (FIG. 5) in particular, for enforcement of restrictions 902 (FIG. 9 ).
Accordingly, SPT interface 114 (FIG. 9) requires assurance from portable player 150 than all restrictions can be enforced by portably player 150 as a precondition to downloading SPT 116 to portable player 150 . Such downloading can include, for example, binding SPT 116 to portable player and copying SPT 116 as bound to a removable storage medium.
Logic flow diagram 1000 (FIG. 10) illustrates the conditional downloading of SPT 116 (FIG. 1) by SPT interface 114 contingent upon assurance by portable player 150 that restrictions 902 (FIG. 9) can be enforced by portable player 150 . In step 1002 (FIG. 10 ), SPT interface 114 receives from portable player 150 a list of restriction types which can be enforced within portable player 150 during registration. Player 110 maintains this restriction enforceability information along with the communication key of player 110 . Accordingly, step 1002 is performed only once for each external player while the following steps are performed as a precondition of downloading each SPT to an external player.
In step 1004 (FIG. 10 ), SPT interface 114 (FIG. 1) determines which restrictions are imposed upon SPT 116 by reference to restrictions 902 (FIG. 9 ). Loop step 1006 and next step 1014 define a loop in which each of restrictions 906 is processed according to steps 1008 - 1012 . During each iteration of this loop, the particular one of restrictions 902 processed by SPT interface 114 is referred to as the subject restriction.
For each of restrictions 902 , processing transfers to test step 1008 (FIG. 10) in which SPT interface 114 (FIG. 1) determines whether the subject restriction is of a type enforceable by portable player 150 . If not, processing transfers to step 1010 (FIG. 10) in which SPT interface 114 refuses to download SPT 116 for portable player 150 and processing terminates in step 1012 . Conversely, if the subject restriction is of a type enforceable by portable player 150 , processing transfers through next step 1014 to loop step 1006 and the next of restrictions 902 (FIG. 9) is processed according to the loop of steps 1006 - 1014 .
When all restrictions 902 (FIG. 9) have been processed in the loop of steps 1006 - 1014 , SPT interface 114 has determined that portable player 150 can enforce all restrictions 902 and processing transfers to step 1016 in which SPT interface 114 proceeds with downloading SPT 116 for portable player 150 . Thus, SPT interface 114 ensures that portable player 150 can enforce all restrictions placed upon SPT 116 prior to making SPT 116 available to portable player 150 .
Smart Media
In one embodiment, storage medium 202 (FIG. 2) is replaced with smart medium 1102 (FIG. 11 ). Smart medium 1102 replaces read-only serial number 204 (FIG. 2) with cryptographic logic 1104 . Cryptographic logic 1104 is embedded in the packaging of smart medium 1102 in a manner which is analogous to the embedding of logic in any currently available smart card, e.g., a plastic card of the approximate dimensions of a credit card with embedded integrated circuitry. Cryptographic logic 1104 performs encryption and decryption using an encryption algorithm and key which are both kept entirely secret within cryptographic logic.
Logic flow diagram 1200 (FIG. 12) illustrates the preparation of SPT 116 (FIG. 1) from one or more of tracks 110 by SPT interface 114 for playback by portable player 150 . In step 1202 (FIG. 12 ), SPT interface 114 (FIG. 1) encrypts the content of one or more of tracks 110 using, for example, symmetric key encryption.
In step 1204 (FIG. 12 ), SPT interface 114 (FIG. 11) sends the master media key to cryptographic logic 1104 for encryption. Cryptographic logic 1104 returns the master media key in an encrypted form. The particular manner in which the master media key is encrypted by cryptographic logic 1104 is not known by, and is of no concern to, SPT interface 114 so long as cryptographic logic 1104 can later decrypt the master media key.
Since the master media key is encrypted using cryptographic logic 1104 , the master media key—and therefore the content of SPT 116 which is encrypted with the master media key—can only be decrypted using cryptographic logic 1104 . By embedding cryptographic logic 1104 in the packaging of smart medium 1102 thereby carefully guarding the secrecy of cryptographic logic 1104 , SPT 116 is bound to smart medium 1102 and can only be played back from smart medium 1102 . SPT 116 cannot be played back from any other storage medium unless cryptographic logic 1104 is accurately replicated. Replication of such embedded logic is particularly difficult, especially for casual listeners of music.
In step 1206 (FIG. 12 ), SPT interface 114 (FIG. 11) forms SPT 116 and stores the encrypted content in SPT 116 . SPT interface 114 stores the encrypted master media key in the header of SPT 116 . SPT 116 is therefore bound to smart medium 1102 .
The security afforded by such binding is more fully appreciated in the context of decoding for playback by portable player 150 as illustrated by logic flow diagram 1300 (FIG. 13 ). In the context of logic flow diagram 1300 , storage media 1102 (FIG. 11) is installed in portable player 150 such that SPTs 116 are accessible to portable player 150 . To playback a selected one of SPTs 116 , player logic 502 A (FIG. 5) reads SPT 116 and parses header 302 (FIG. 3) therefrom and parses the encrypted master media key from header 302 in step 1302 (FIG. 13 ).
In step 1304 (FIG. 13 ), player logic 502 A (FIG. 5) sends the encrypted master media key to cryptographic logic 1104 (FIG. 11) for decryption. Cryptographic logic 1104 returns the master media key in an un-encrypted form. The particular manner in which the master media key is decrypted by cryptographic logic 1104 is not known by, and is of no concern to, player logic 502 A (FIG. 5 ). Since player 110 (FIG. 1 ), SPT interface 114 , and player 150 do not know the particular encryption/decryption algorithm implemented by cryptographic logic 1104 (FIG. 11 ), the secrecy of that algorithm is more easily protected.
In step 1306 (FIG. 13 ), player logic 502 A (FIG. 5) decrypts the content of SPT 116 using the decrypted media master key. After step 1306 (FIG. 13 ), the content of SPT 116 is un-encrypted and is available for decompression and playback by player logic 502 A. Decompression and playback of the un-encrypted content is conventional.
External Player Registration
As described above, player 110 (FIG. 1) requires device identification data such as read-only key 504 A (FIG. 5) to bind SPTs 116 to a particular external player such as portable player 150 . To register portable player 150 (FIG. 1 ), portable player 150 communicates with player 110 , e.g., through I/O port 140 and SPT interface 114 . Portable player 150 can be coupled to I/O port 140 using a convenient cradle such as those used in conjunction with currently available portable MP3 players and with the Palm series of personal digital assistants (PDAs) available from 3Com Corp. of Santa Clara, Calif. For external players which are somewhat less portable, e.g., components of a home stereo system, CLP 512 A (FIG. 5 ), certificate 508 A, key pair 510 A, and keys 504 A and 506 A 1 - 4 can be included on a smart card such as those used in conjunction with currently available digital satellite system (DSS) receivers. Such smart cards can be inserted into a reader coupled to I/O port 140 (FIG. 1) to carry out registration and key exchange and re-inserted in the stereo system component external player for playback of SPTs 116 . Dash-mounted external players in a car can include CLP 512 A (FIG. 5 ), certificate 508 A, key pair 510 A, and keys 504 A and 506 A 1 - 4 in a detachable face plate such as those commonly used for theft deterrence. The detachable face plate can be coupled to I/O port 140 (FIG. 1) through a cradle similar to those described above except that the form of the cradle fits the detachable face and include electrical contacts to meet contacts included in the detachable face plate.
Once portable player 150 is in communication with SPT interface 114 , and therethrough with player 110 , portable player 150 and player 110 conduct a key exchange in the manner described above. As a result, player 110 has a copy of read-only key 504 A (FIG. 5) and can bind SPTs 116 to portable player 150 . To allow the user of portable player 150 to acquire music products at locations other than computer system 100 (FIG. 1 ), player 100 can upload read-only key 504 A to a server computer system through computer network 170 in a cryptographically secure manner. In an embodiment in which computer network 170 is the Internet, the user can purchase content at any of a great multitude of computer systems all over the world and, in addition, at specially designated kiosks at various retail locations. Upon proper authentication of the user at any such site, the user can purchase and encode SPTs 116 for portable player 150 and, indirectly, for any external player with which portable player 150 has exchanged keys.
The above description is illustrative only and is not limiting. The present invention is limited only by the claims which follow. | Data such as a musical track is stored as a secure portable track (SPT) which can be bound to one or more players and can be bound to a particular storage medium, restricting playback of the SPT to the specific players and ensuring that playback is only from the original storage medium. The SPT is bound to a player by encrypting data of the SPT using a storage key which is unique to the player, is difficult to change, and is held in strict secrecy by the player. The SPT is bound to a particular storage medium by including data uniquely identifying the storage medium in a tamper-resistant form, e.g., cryptographically signed. The SPT can also be bound to the storage medium by embedding cryptographic logic circuitry, e.g., integrate circuitry, in the packaging of the storage medium. The SPT is bound by encrypting an encryption key using the embedded logic. By using unique cryptographic logic, only that particular storage medium can decrypt the encryption key and, therefore, the data of the SPT encrypted with the encryption key. To allow a user to playback the SPT on a number of players, players can share storage keys with one another. Such key sharing is done in a cryptographically secure manner. Before downloading an SPT to a particular external player, the ability of the external player to enforce restrictions placed upon the SPT is verified. | 6 |
BACKGROUND
This is a continuation-in-part of application Ser. No. 08/359,802 filed Dec. 20, 1994 which is now abandoned.
FIELD OF THE INVENTION
The present invention relates generally to shipping and storing thermally sensitive materials such as biologically active proteins and medicaments, and more particularly to containers for maintaining such materials at an essentially constant temperature during transport and storage.
STATE OF THE PRIOR ART
With the recent development of recombinant DNA technologies, increasing numbers of biologically active materials such as peptides, proteins and glyco-proteins have become available for research and therapeutic use. These products have a significant potency and are frequently supplied as dilute aqueous solutions of the active ingredient combined with small quantities of pharmaceutically acceptable adjuvant and carrier substances such as serum albumin. It is believed that if the solution freezes, it can generate physicochemical alterations which are not spontaneously reversible upon thawing, such as formation of both lower and higher molecular weight species of the proteins. These changes could potentially affect the biological potency of the products which have been subjected to freezing. A common problem encountered with transporting and storing pharmaceuticals is to maintain the pharmaceutical preparation within a constant temperature range.
The prior art is rife with various container designs fashioned from polymer materials, alone or in combination with cardboard or particle-board boxes. Shipping boxes with insulated interiors run the gamut from ubiquitous "food-coolers" to esoteric single vessel transport units. For example, a cardboard box filled with foam peanuts surrounding a second cardboard box holding the medicament is but one common embodiment. Other examples are plastic containers which are filled with open cell or closed cell foam and contain a cutout adapted to receive a second box, the second box contains the medication. Still another commonly employed container is an inner vessel surrounded by a space which has been evacuated of air and surrounded by a second or outer wall (i.e. the Thermos® bottle).
Persons seeking to transport highly labile samples, which must be maintained in a frozen state, have used ice and dry-ice for maintaining temperatures sufficient to keep the samples in a frozen condition. Unfortunately, the use of dry-ice preparations are of limited utility due to rapid evaporation, and as well may be dangerous due to the release of carbon dioxide. The use of ice and dry-ice creates the untoward risk of introducing a toxic contaminant, or a pathogen.
Still, other transportable containers rely on refrigeration units to maintain sub-ambient conditions. With these systems a power failure, which might proceed undetected, could prove fatal to the efficacy of the preparation.
While most people are familiar with spoilage due to exposure to heat, or to sub-freezing temperatures, maintaining a constant temperature within ambient values is a highly desirable objective. There is a vast array of pharmaceutical preparations that must be maintained within an ambient temperature range. The preferred range is generally from about 40° to 80° Fahrenheit. Therefore, the container must prevent extreme changes in outside temperatures which are often encountered in shipping from affecting the preparation contained therein. A shipment of pharmaceuticals which is stored on the tarmac prior to loading on an aircraft must endure elevated temperatures for extended periods of time. On the other hand, once loaded in the aircraft the medicaments are often exposed to sub-freezing temperatures during flight.
The emphasis of prior art containers teaches the construction of containers for maintaining a payload at sub-ambient temperatures.
Schea, III et al. U.S. Pat. No. 5,181,394 issued Jan. 26, 1993 discloses a previous attempt to provide a shipping and storage container adapted to maintain vials of liquid in a refrigerated, but not frozen state. The container comprises an outer side wall having the shape of a rectangular open tray and an inner side wall having a number of wells to accommodate a number of vials. The inner and outer side walls are dimensioned and shaped to nest the inner side wall component within the outer side wall component. A phase change material comprising a freshly prepared mixture of water and 2% by weight self-gelling carboxymethylcellulose is provided between the inner and outer side walls. A freeze indicator is positioned within the container and exhibits a color change upon being subjected to temperatures below a predetermined level. The carboxymethylcellulose gel exhibits relatively poor insulating properties, and conducts heat from the vials.
U.S. Pat. No. 5,355,684 issued to Guice discloses a shipping container for the cryogenic shipping or storage of biologic materials. Further, this invention utilizes a plurality of "heat sinks" disposed within an insulated container. The heat sink material is preferably composed of a phase change material that is first frozen and as it thaws, absorbs free heat to keep the sample inside the vessel in a frozen condition.
U.S. Pat. No. 5,058,397 issued to MacDonald discloses a storage container where microcentrifuge tubes are embedded into a coolant matrix of gel. Overlying the embedded tubes is a gel contained in an envelope within a lid means which is comprised of an envelope of gel.
U.S. Pat. No. 4,250,998 issued to Taylor discloses a container for transporting insulin and syringes wherein there is an insulated container with a plurality of cavities. The inner cavities are to be filled with water for freezing, while the outer cavities are designed to house the syringes.
SUMMARY OF THE INVENTION
A container according to the present invention provides for storage and shipping of vessels containing a liquid composition susceptible to physicochemical alteration upon freezing or upon exposure to elevated temperatures. It comprises an enclosure created by an upstanding means. It is best illustrated by a plurality of upstanding walls where there are at least two pairs of opposing walls of essentially equal dimensions thereby defining an inner space. The base portion of the enclosure contains a first heat sink, comprising a thermal energy absorbing phase change material. A vial holder is disposed within the chamber and thereby divides the container into a bottom chamber and top chamber. The vial holder is adapted to hold one or more of the vials suspended within the bottom chamber and above the first heat sink. The vial holder possesses a like number of apertures therethrough so that the resulting array of apertures is essentially in an equidistant relation to one another. A central aperture is disposed in an equidistant relationship relative to the other apertures. Within the central aperture there is a temperature indicator means disposed within a housing of a similar size and shape of the proposed sample containers which are to be disposed within the apertures to signal exposure to contraindicated temperatures. An insulating gas is contained in the inner space.
A lid may be introduced to seal the top chamber and provide closure to the container. The lid is removably retained and provides access for removal of the vessels held in the planar holder. Additionally, the lid houses a second heat sink which incorporates the same phase change material as in the first sink.
The vial holder is a thin planar panel, resides above the first heat sink and possesses at least one or more apertures for receiving the vials. The vial holder divides the container into top and bottom chambers. When in a closed condition, the vial holder retains the vials within the bottom chamber while a gas, namely air surrounds the vials.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features, objects and advantages will become evident from the following detailed description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings, in which;
FIG. 1 is an exploded view of a storage container according to the invention;
FIG. 2 is a plan view of the container of FIG. 1 with a lid of the container partially cut away to reveal an inner vial holder;
FIG. 3 is an elevational view in cross section taken along line 3--3 of FIG. 2;
FIG. 4 is an elevational view as a partial cut-away thereof;
FIG. 5 is a top plan view of the container in an opened condition;
FIG. 6A is an alternate top plan view thereof;
FIG. 6B is an alternate top plan view thereof;
FIG. 7 is an elevational view of the vial holder;
FIG. 8. is an elevational view in cut-away of the container in a closed condition;
FIG. 9 is a cross-sectional view of the container of the capillary tube and bulb;
FIG. 10 is a bottom plan view depicting the reinforcing ribs; and
FIG. 11 is a perspective view of the container.
DETAILED DESCRIPTION
Turning now to the drawings wherein like numerals refer to like parts throughout, FIG. 1 depicts a container for transporting and storing temperature-sensitive materials, said container being generally identified by the numeral 10. Although, container 10 can be of a triangular, rectangular, circular or other construction, for purposes of the present invention, the preferred container shape for description will be essentially rectilinear.
In accordance with the present invention and FIG. 1, walls 12, 14, 16, and 18 are integral and in communication with each other and base 20. The resulting preferred assemblage is essentially box-shaped, being closed on the bottom end by base 20 and open on the opposing end.
Turning to FIG. 2, base 20 is of a reduced dimension there-around, in relation to upstanding walls 12, 14, 16, 18, and at its meeting point provides shoulder 44. Panel 22 is in communication with base 20 at shoulder 44 and may be hermetically affixed thereon. The cell created by the aforesaid union provides a receptacle for a first heat sink 24.
The tops of each wall 12, 14, 16 and 18 terminates in an outwardly projecting flange area 38. Pursuant to FIGS. 1&2, lid 26 is adapted to close container 10 by nesting within the open end of said container 10 and by reversible interlocking engagement between flanges 36 and 38. Lid 26 is further comprised of panel 28 which is in integral communication as by being hermetically affixed to upper lid surface 30 and provides a cavity 32 for second heat sink 34. Second heat sink 34 projects downward and thereby furnishes an indented area of approximately the same dimensions as the opening formed by upstanding walls 12, 14, 16, 18 of container 10 to effect closure by nesting and interlocking engagement thereto.
For purposes of the present invention, differences in outside temperature will act upon a container by virtue of the phenomena of heat transfer. Heat is energy that flows, by virtue of a temperature differential, from regions of higher temperature to lower temperature. The various modes of heat transfer are by conduction, radiation and convection. In the instant regard, the greatest change in sample temperature occurs as a result of conduction.
Conduction takes place on the molecular level and involves the transfer of energy from more energetic molecules to molecules possessing less energy. Hence, the closer the molecules are to one another, the greater the incidence of collision and transfer of energy. Conduction would be greater where molecules touch each other and significantly less as the density of molecular space increases. Heat flux, or the rate of heat flow from greater temperature to lower temperature, is therefore proportionate when taken in view of the thermal conductivity of the material.
In addition, there are yet other phenomena that exist when one speaks in terms of heat transfer. Where there are different species of chemically distinct molecules there exists a concentration gradient. The term mass transfer describes the relative motion of species in a mixture due to the presence of concentration gradients. Heat will move across the gradient from areas of greater concentration to lesser concentration.
Radiation, or more appropriately in terms of the instant case, thermal radiation is electromagnetic radiation emitted by a body by virtue of its temperature and at the expense of its internal energy. Unlike conduction, radiation does not require a material medium.
Finally, the container when exposed to the vagaries of shipping will be exposed to convection. Although the sample itself will be almost immune from the direct effect of the outside convective force, the environment inside will not. Convection, as a transfer mode relates to the transfer of heat from a bounding surface to a fluid in motion or to the heat transfer across a flow plane within the interior of the flowing fluid. Mainly, the phenomenon requires the flow of a fluid or gas over a surface. When the container is exposed to the elements, as during shipping or upon exposure to ambient conditions, air currents outside the container will act upon the container encouraging changes in temperature within the container. Inside the container, the vibratory motion encountered during transportation will encourage heat transfer and temperature change, as will natural convection currents produced by the inherent temperature differential within the container.
In the preferred embodiment as shown in FIG.2, there are two heat sinks 24 and 34. Heat sinks 24 and 34 cooperate to provide a media to absorb increases or decreases in temperature within bottom chamber 42 and top chamber 40. For purposes of the present invention, the preferred heat sink material is a phase change material. As a class, phase change materials can absorb a tremendous amount of heat energy in their transition between phases. When maintained in a frozen state, the product of net specific heat and density would represent an inverse logarithmic relationship. For example, once the material which has been in a frozen condition reaches the point of freeze/thaw, the temperature remains substantially constant until complete melting occurs. Maintaining a temperature plateau allows for great amounts of heat to be absorbed at a constant rate, and encourages maintenance of a constant ambient interior container temperature. Therefore, heat sinks 24 and 34 are preferably constructed from a phase change material such as carboxymethylcellulose gel, having a freezing temperature of approximately -1° C. It should be noted that most phase change materials like carboxymethlycellulose are relatively poor insulating materials. Other materials for constructing heat sinks are phenols, salts, water, glycols, starches and alcohols.
Heat sinks 24 and 34 preferably exhibit a phase change at a temperature slightly above the freezing temperature of the liquid contained within vials 100. Thus, when container 10 is exposed to a temperature below the freezing temperature of the liquid in vials 100, a large quantity of heat energy relative to the mass of the phase change material within heat sink 24 and 34 must be dissipated to the external environment before the temperature of the heat sinks 24 and 34 will fall below the freezing temperature of the liquid in the vials 100. Heat sinks 24 and 34 thus provide a thermal damping effect against temperature changes in the environment of the container 10. In accordance with the present invention, using a total weight of carboxymethylcellulose of 6.5 ounces, container 10 should resist 8 hours of exposure to a -20-degree Celsius external temperature.
As described hereinabove, the heat sink material may be chosen from a variety of materials, based on their freezing point and the desired temperature at which the sample is to be maintained. For example, many alcohols or glycols are particularly suited for maintaining sub-ambient interior temperatures. Alcohols, glycols or any compound that has an extremely low freezing point, once frozen, requires a great amount of heat to raise their temperature above its freezing point and the freezing point of a biologic sample.
Returning to the preferred embodiment of FIGS. 1 and 2 base 12 is substantially equilateral and square in overall shape, having walls 12, 14, 16, and 18 integrally connected thereto by hermetically sealed or thermo-formed. Panel 22 is in communication with the aforesaid walls and is joined at a lower portion 24. At their lower extent, the walls 12, 14, 16, 18, extend inwardly to form support lip 44 which supports panel 22. A well formed within the boundaries of panel 22 and base 20 contains a first heat sink 24.
First and second heat sinks 24 and 34 may be retained within a well or envelope formed by hermetically sealing panels or sides to each other. Various other embodiments or materials could be operatively substituted. For example, solids like dry-ice or frozen aqueous solutions which remain solid through their "phase change" would obviate the need for encapsulating a gel material. An indented base 20 lends a distinctive appearance to container 10 as well as providing greater stability. The material contained within base 20 provides sufficient weight to encourage maintenance in an upright position.
Walls 12, 14, 16, 18, base 20 and panel 22 are preferably formed from a thermoplastic polymer component like polyvinyl chloride, PETG or a similar thermoplastic polymer. When constructed as by injection molding or by another thermo-forming method said walls 12, 14, 16, 18 and base 20 are integral. Panel 22 is preferably hermetically affixed to outstanding lips 44 so that first heat sink 24 may be disposed therein. Lid 26 is fashioned from the same polymer as panel 28, and upper lid panel 30 communicate to form downward depending well 32. Lid 26 provides downwardly depending sides 46, 48, 50, and 52 and flange 36 which reversibly communicates with flange 38 of wall 12, 14, 16, and 18 thereby encouraging closure of container 10 as seen in FIGS. 8 and 2.
Downward depending well 32 corresponds to the inside dimension of open container 10 as defined by inner wall surfaces of vial holder 56 and nests therein to accomplish closure while discouraging lateral movement. To effect closure of container 10, lid 26 reversibly nests within the space defined by upstanding walls 12-18, and upward disposed flange 38, in accordance with FIG. 2, extends outwardly radially from the upper extent of the sidewalls. A downwardly disposed flange 36 extends downwardly from outer edges 54 of upper panel 28 of the lid 26. Upper flange 36 and downward flange 38 engage each other to hold the lid 26 in a reversibly interlocked condition. A detente or interlocking members (not shown) may be provided on either the downward flange 36 or upper flange 38 to more securely attach the lid 26. Preferably, upper panel 28 and the downward flange 36 are formed as a single thermo-formed plastic part.
Walls 12, 14, 16, 18 and lid 26 are the first barrier to prevent temperature changes within the container. The thermoplastic polymer is non-porous, insulating and retards heat transfer. Therefore, depending on the thickness of the polymer there will be an insulating or "R" factor, while the material itself will by definition facilitate or retard heat transfer by virtue of its "K" factor. Not only does the non-porous material prevent radiation but also the inherent insulation rating of the material itself heat transfer through conduction. Finally, heat loss from convection caused by air passing over the non-porous outer skin of the container greatly reduces heat transfer within the container.
Vial holder 56 possesses a step-shaped appearance and contains peripheral ledge 58 which creates a horizontal surface to abuttingly retain insulating insert 68, said ledge approximates the width dimensions of the upper surface of insulating insert 68, and is secured thereon. Surfaces 58, 60, 62,64 depend substantially inward and downward from an outer edge flange 104 of vial holder 56 and terminates in an outwardly extending flange 38. Vial holder 56 and outer edge flange 104 rests atop insulating insert panel 68, and walls 12, 14, 16, 18. Preferably, vial holder 56 is formed from a single piece of plastic in a thermo-forming operation and communicates with sidewalls 12-18, insulating insert 68 and flange 38 being hermetically affixed thereon. Further, vial holder 56 divides container 10 into a top chamber 40 and bottom chamber 42.
As shown by FIGS. 1 and 2 depict placement of insulating insert 68 which is immovably retained adjacent to the inner surface of walls 12, 14, 16 and 18 by vial holder 56. As best seen in FIG. 2, surfaces 62 and 64 extend over and abut insulated insert 68. Surface 62 and surface 64 conform dimensionally to insulated insert 68 and immovably retain said insulated insert in position around the inside of walls 12, 14, 16, and 18. Overall both insert members 70 and 72 and surfaces 62 and 64 are angled sufficient to constitute mating as seen in FIGS, 2 and 8. Insulated insert 68 is preferably comprised of two L-shaped members 70 and 72 which abut one another. Insulated insert 68 is thus held securely between the lower panel 22, sidewalls 12, 14, 16, 18 and vial holder 56, and is preferably hermetically affixed or sonically welded within. Other means of affixing by the use of adhesives or by thermo-forming procedures may be substituted.
Insulating insert 68 contributes a shock absorbing component to the assemblage. Insulating insert 68 when derived from the preferred material, a closed cell foam like polyvinyl chloride, urethane or PETG, or other closed cell polymer insulator, absorbs shock waves by the inherent memory of the polymer. Not only is mechanical damage to the vials prevented, but also convection within the chamber is discouraged. Vial holder 56 is preferably formed of a single piece of plastic in a thermo-forming operation.
In accordance with FIG. 7 a series of buttresses or support struts 98 are disposed on the bottom of base 20. Struts 98 prevent deformation of the container caused by expansion of the gel of heat sink 24. Therefore, struts 98 prevent a bowing outward from the bottom of container 10, while providing overall rigidity to retard outward expansion of base 20. While the preferred embodiment is X-shaped, struts which encourage container support and structural integrity may be operatively substituted.
The preferred representation of vial holder 56, as illustrated by FIGS. 5 and 6, is further comprised of a series of descending surfaces. Hence horizontal peripheral ledge 58 descends via vertical wall 60 to slanted surface 62 which in turn and in a step-wise relation descends via wall 64 to planar surface 102. Planar surface 64 resides above the panel 22. Said planar surface 102 contains a plurality of apertures 66a-f adapted to receive a like number of vials therethrough. A central aperture 88 furnishes said plurality of apertures 66a-f a point for their arrangement in equidistant relation thereto. In accordance with FIGS. 5, 6A and 6B the overall disposition of apertures is in a circular pattern around central aperture 88. Therefore, notwithstanding the geometric figure which results, an infinite number of points which are equidistant to a central point or in circular arrangement may be operatively substituted. A further advantage inherent to the equidistant arrangement is that the vials will undergo equal cooling.
Central aperture 88 is adapted to receive temperature indicator 74. Central aperture 88 is of a reduced diameter and is adapted to receive capillary tube 86 of stem 82 and prevents bulbous portion 84 from falling therethrough. Temperature indicator 74 is assembled as a unit with dome 78 interlocking with retention ring 80 thereby preventing stem 82 and bulbous portion 84 from ejecting upward and outward therefrom.
In the preferred embodiment, panel 102 possesses an aperture centered on said panel and a plurality of apertures 66a-f which is adapted to receive a like number vials 100 of medicaments, as seen in FIGS. 5, 6A and 6B. Said vials 100 are retained within said apertures 66a-f.
FIGS. 2 and 8 show container 10 in an assembled condition, vial holder 56 and vials 100 are so situated within chambers 40 and 42 and above panel 22 and below panel 28 or above first heat sink 24 and below second heat sink 34, so that vials 100 placed in apertures 66a-f are held suspended within bottom chamber 42. Vials 100, thus positioned, are substantially spaced from the sidewalls 22 and are positioned above the first heat sink 14.
Entrapped gases which, by definition, possess a random molecular configuration, are excellent insulators. Lid 26 and base 20 defining the uppermost boundaries of top and bottom chambers 40 and 42 may contain an insulating gas, in this case air, to insulate vials 100 from the vagaries of the exterior environment. Heat sinks 24 and 34 and the carboxymethylcellulose contained therein conducts heat from the vials faster than air. Thus, by not directly embedding the vials within the gel, heat loss from the vials is reduced.
Turning to FIGS. 1 and 4, temperature indicator 74 resides within central aperture 88. Temperature indicator 74 comprises a casing 76 of approximately the same dimensions as vials 100a-f to be retained within apertures 66a-f and having an outwardly extending outer edge flange 104 at its upper extent. Flange 104 attaches to or is integral with panel 102 of vial holder 56 and surrounds a central aperture of reduced circumference 88. Casing 76 thus depends beneath the panel 102.
A clear dome cover 78 fits over casing 76. It has an outwardly extending radial flange 106 which attaches to panel 102 of vial holder 56 and adjacent the cylindrical casing flange 104. An upper surface 108 of dome cover 78 is preferably planar and imprinted with a warning regarding the color change of the indicator and including a toll-free number which a user may call for information regarding proper use of container 10 (see also FIG. 2).
Disk-shaped divider 80 fits between casing 76 and dome cover 90. A central aperture of reduced diameter 110 in divider 80 receives elongated ampule 82. Bulbous portion 84 of ampule 82 at an upper end of ampule 82 is larger than the divider aperture 110 whereby the ampule 82 is supported upon divider 80 and held secure by dome cover 78. Ampule 82, casing 76 and dome cover 78 are dimensionally similar so that when assembled, ampule 82 cannot move up and out of divider 80 through aperture 88, even if the container 10 is completely inverted. Also, temperature indicator 74 is preferably permanently attached to the vial holder 56 so that vials 100 cannot be shipped or stored without said indicator 74.
Turning to FIG. 4, bulbous portion 84 of temperature indicator 74 contains a clear fluid 90 which contracts upon freezing, preferably, a mixture of 75% octyl caprate and 25% hexyl laurate. Temperature indicator 74 further comprises a capillary stem 100 and the clear fluid 90 extends partially into the stem 86. Stem 86 contains a liquid barrier chemical 92, preferably ethylene glycol AR grade and green food dye, adjacent the clear fluid 90. A violet liquid 94, preferably a mixture of 98% iso-amyl laurate and 2% waxoline violet BA dye, is contained within the stem 86 on an opposite side of the barrier chemical 92.
Barrier chemical 92 tends not to mix with either the clear fluid 90 or the violet liquid 94 and thus keeps the violet liquid 94 out of the bulbous portion 84. The capillary nature of the stem 86 also prevents the layers 90, 92 and 94 from mixing. However, when the clear liquid 90 freezes, it contracts and pulls the violet liquid 94 into the bulbous portion where it irreversibly mixes with the clear liquid 90 to produce a noticeable color change therein. The divider 96 is preferably white or another light and contrasting color so that the color change is easily visible.
Alternatively, a temperature indicator can be provided which contains a frangible ampule (not shown, but as is well known in the art) which breaks upon the freezing and expansion of a liquid contained within the ampule. Preferably, an indicator sensitive to the liquid is provided to show a color or other change indicating that the ampule has broken. To improve the accuracy of such an indicator, the liquid may comprise a placebo preparation of the liquid contained within vials 100.
Yet another aspect of the present invention is clear from FIG. 2 which illustrates that the temperature indicator itself can be retained in a vial-shaped holder having substantially the same structure and properties as the vials holding the active contents. By providing apertures to retain vials in a substantially equidistant relationship, and a fluid or gas between the vial-shaped holder and the temperature indicator, so that theh temperature indicator suffers a similar temperature differential as the vials carrying the active contents. Unlike the prior art which teaches in-line disposition of its contents, the instant invention will provide a true reading of temperature ranges which may affect the vials.
Should vials 100 stored in container 10 be exposed to ambient temperature conditions sufficient to overcome the insulating and thermal moderating effect of the container 10, clear liquid 90 will freeze and trigger the color change within temperature indicator 74. By simply opening lid 26 of container 10, a user will thus be alerted to the possibility that the contents in vials 100 have been exposed to temperatures below their freezing point or above the temperature necessary to maintain stability. Preferably, the temperature which triggers the visual indicia of temperature indicator 74 should be slightly above the freezing point of the liquid or slightly below the temperature necessary to maintain stability of the substance in vials 100. Moreover, the choice of a phase change material for heat sinks 24 and 34 can be chosen from the groups listed hereinabove to suit the temperature range of temperature indicator 74.
While the invention has been particularly described in connection with specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and that the scope of the appended claims should be construed as broadly as the prior art will permit. | A container is disclosed for storing and transporting vessels containing a liquid composition susceptible to physicochemical alteration upon changes in temperature above or below a specified temperature. It comprises an enclosure having a lower portion, a top portion and a side portion between the lower and top portions thereby defining an inner space. A lower portion of the enclosure contains a first heat sink within a base, comprising a thermal energy absorbing substance. A vial holder in the inner space holds one or more of the vessels in the inner space above the first heat sink and substantially spaced from an insulated insert inside of the enclosure. An insulating gas is contained in the inner space. A temperature indicator in the inner space indicates when the inner space has been subjected to temperatures below a predetermined level. | 5 |
BACKGROUND TO THE INVENTION
The present invention relates to a machine for use in mining or tunnelling operations.
U.S. Pat. No. 4,056,284 assigned to the same assignee as the present application describes a machine of the type with which the present invention is concerned and is herein incorporated by reference. The machine described in U.S. Pat. No. 4,056,284 utilizes as a loading means, a unit composed of conveyors and a material-receiving means, similar to a shovel, which receives material detached by the cutters at the end of a swinging arm or jib. A device is oscillated back and forth over the shovel to transfer material accumulating on the shovel onto the conveyors. The shovel together with front regions of the conveyors can be raised and lowered. This arrangement is not particularly adaptable to the prevailing conditions and a general object of this invention is to provide an improved mounting system for the loading means of the machine.
SUMMARY OF THE INVENTION
A machine constructed in accordance with the present invention has a frame or chassis supporting a jib or arm provided with cutting means and which can be moved in a variety of directions to attack a working face. Material receiving means such as a ramp-like shovel is disposed beneath the arm and its cutting means to receive material detached by the cutting means directly or otherwise. The material thus received is transferred to at least one conveyor leading away from the working face. In accordance with the present invention, the material-receiving means is mounted to the machine so it can be moved in a vertical sense and also tilted. Thus enables the material-receiving means to be adjusted to a desired position even when the machine is standing in an inclined disposition or when material has accumulated on the floor of the working unevenly. As is known per se, an oscillating device may transfer material from the upper face of the material-receiving means onto a pair of conveyors disposed at the sides of the machine chassis.
In a preferred embodiment of the invention the material-receiving means is supported on a bearing member, such as a beam, which is itself pivotably supported on the machine chassis to provide for the lateral tilting of the material-receiving means. The latter component may then be mounted for pivoting in a vertical sense on the bearing member. The pivot connection or joint between the machine chassis and the bearing member may take the form of a stout king pin engaging in a socket and having its pivot axis directed towards the working face.
Piston and cylinder units can be used to move the bearing member about its pivot connection with the machine chassis or frame. It is desirable to design the associated hydraulic system so that these units can be locked in the hydraulic sense with the bearing member set in a desired orientation and working position. At least one additional piston and cylinder unit can be used to adjust the material receiving means in the vertical sense by swinging the latter about its pivot connection with the bearing member.
It is also possible to connect the material-receiving means to the bearing member via parallel guide rods which render the material-receiving means vertically pivotable and bodily vertically adjustable.
The invention may be understood more readily, and various other aspects and features of the invention may become apparent, from consideration of the following description.
BRIEF DESCRIPTION OF DRAWINGS
An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawing wherein;
FIG. 1 is a schematic side view of a machine constructed in accordance with the invention,
FIG. 2 is a side view of part of the machine taken on a somewhat larger scale, and
FIG. 3 is a perspective view of the mounting arrangement depicted in FIG. 2.
DESCRIPTION OF PREFERRED EMBODIMENT
As shown in FIG. 1, a machine constructed in accordance with the invention is composed of a main frame or body 12 supported for displacement on the floor of a working on two endless tracks 10. These tracks 10 are preferably driven hydraulically and are individually controlled and driven so the machine can be steered and manoeuvred. The frame 12 in turn carries a table or platform 13 which can be pivoted about a vertical axis in relation to the frame 12 by means of a pair of hydraulic piston and cylinder units 14. A superstructure or turntable 15 is mounted on the platform 13 and accommodates a support 16 which is pivotable or rotatable about an axis parallel to the longitudinal axis of the machine. The movement of the support 16 is effected by means of a pair of hydraulic piston and cylinder units 17 which are flexibly interconnected between the support 16 and the platform 13. The support 16 carries a bearing member 19. The bearing member 19 can be displaced longitudinally of the machine so as to extend or retract in relation to the support 16. This motion is effected by two hydraulic piston and cylinder units 18 flexibly interconnected between the support 16 and the bearing member 19. The bearing member 19 carries a cutting arm or jib 21 by way of a pivot joint 20 which permits the arm 21 to be raised or lowered. A cutting head 22 is provided at the free end of the arm 21 and this cutting head 22 can take the form of two cutter drums or rollers which are rotatably driven about an axis perpendicular to the longitudinal axis of the arm 21. The drive system for the cutting head 22 is conveniently located within the cutting arm 21. Two hydraulic piston and cylinder units 24 serve to raise or lower the arm 21 by pivoting about the joint 20. These units 24 are flexibly interconnected between the arm 21 and the member 16 and are at partly located inside the support 16. By operating the units 17, 18, 24 selectively the arm 21 can be brought into a variety of positions with respect to a working face 25, so the cutting head 22 can remove material over the entire face 25.
Beneath the cutting arm 21, there is material loading means composed of means for receiving material in the form of a shovel or ramp 27 which is inclined in relation to the floor 26 of the working. This shovel 27 is mounted to the frame 12 in a manner now described with reference to FIGS. 2 and 3. As shown in these Figures, a bearing member 28 is supported for tilting or swivelling motion on a pivot joint 29 formed at the front of the frame 12 only shown diagrammatically. The pivot axis of the joint 29 is directed towards the local working face 25 and can be disposed parallel to the longitudinal axis of the machine or inclined thereto. The pivot joint 29 is constituted by a strong rigid king pin 30 located more or less centrally of front end of the frame 12 and engaging in an aperture or socket 31 formed in the bearing member 28. The swivelling motion of the bearing member 28 is designated by the arrows in FIG. 3. The bearing member 28, which may take the form of a stout beam, is swivelled about the joint 29 with the aid of a pair of hydraulic piston and cylinder units 32 located at the sides of the joint 29. These units 32 are upstanding and flexibly interconnected between the frame 12 and the bearing member 28. By selective retraction and extension of the units 32 the bearing member 28 can be swivelled about the joint 29 in either a clockwise or anti-clockwise direction.
The bearing member 28 is provided with connection brackets 33 near its ends at either side of the joint 29. The shovel 27 is supported on the brackets 33 with the aid of pivot joints formed by pins locating in aligned apertures 34 in the brackets 33 and the shovel 27. The brackets 33 also support hydraulic piston and cylinder units 35 which are likewise pivoted thereto with pins locating in aligned apertures 34 in the lower regions of the brackets 33 and in head pieces of the piston rods of the units 35. The cylinders of the units 35 are pivotably linked to the shovel 27 so that by operating the units 35 the shovel 27 can be raised and lowered relative to the brackets 33. By operating the units 32, the shovel 27 can be tilted to one side or the other, while the units 35 enable the shovel 27 to be raised or lowered to any desired height. The material detached from the face 25 can thus be loaded onto the shovel 27 and if the machine is driven forwards to make the shovel 27 penetrate the material, the impact forces can be transferred to the machine frame 12 via the bearing member 28.
As represented in FIG. 1, at the upper side of the shovel 27, there is provided a transfer device or arm 30 which is designed to oscillate to and fro about an axis perpendicular to the shovel 27. In this way, material on the upper face of the shovel 27 is forced sideways onto two conveyors 41. These conveyors 41, which may take the form of scraper-chain conveyors, are located at the sides of the machine and are connected at their front end zones to the sides of the shovel 27 so as to move therewith. At their rear end zones, which are elevated, the conveyors 41 discharge the material and here the conveyors 41 are supported on a support and drive means 42. To accommodate for the displacement of the shovel 27, it is desirable to sub-divide the front end zones of the conveyors 41 from the remainder of the conveyors 41 and to provide a flexible joint or pivot joint therebetween. | A machine for use in mining or tunnelling has a chassis supporting a mobile arm provided with rotary cutters. A shovel beneath the arm serves to transfer material onto a pair of conveyors mounted alongside the machine chassis. This shovel is supported for vertical pivoting displacement on a beam which is itself linked via a central pivot joint to the machine chassis. Piston and cylinder units effect tilting and vertical adjustment in the shovel position. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Patent Application No. 10-2015-0019688, filed on Feb. 9, 2015, the entire contents of which are incorporated herein by reference.
FIELD
[0002] The present disclosure generally relates to a multi-stage transmission for a vehicle.
BACKGROUND
[0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0004] Recent rising oil prices have driven worldwide car manufacturers into unlimited competition to improve fuel efficiency. In addition, great efforts have been made to reduce the weight and improve the fuel efficiency of engines based on a variety of techniques such as downsizing and similar measures.
[0005] Another method used to improve fuel efficiency is allowing an engine to operate at more efficient operation points using the multi-staging of a transmission.
[0006] Additionally, the multi-staging of a transmission allows an engine to operate in a relatively low RPM (revolutions per minute) range, thereby improving the quietness of a vehicle.
[0007] However, as the number of shifting stages of a transmission increases, the number of internal parts constituting the transmission also increases. This may lead to undesirable effects, such as reduced mountability and transfer efficiency of the transmission and increased cost and weight of the transmission.
SUMMARY
[0008] The present disclosure provides a multi-stage transmission for a vehicle that is able to realize at least ten forward shifting stages and one reverse shifting stage with a relatively small number of parts and a simple configuration such that an engine may be operated at desired operation points, thereby improving the fuel efficiency of the vehicle, and improving the quietness of the vehicle.
[0009] According to one aspect of the present disclosure, a multi-stage transmission for a vehicle is provided including: an input shaft; an output shaft; a first, second, third, and fourth planetary gear device disposed between the input shaft and the output shaft to transmit rotary force, each of the planetary gear devices having three rotary elements; and at least six shifting elements connected to the rotary elements of the planetary gear devices. A first rotary element of the first planetary gear device may be installed to be fixable by one shifting element of the at least six shifting elements, a second rotary element of the first planetary gear device may be permanently connected to a third rotary element of the third planetary gear device and a third rotary element of the fourth planetary gear device, and a third rotary element of the first planetary gear device may be variably or selectively connected to a first rotary element of the second planetary gear device and a second rotary element of the third planetary gear device. The first rotary element of the second planetary gear device may be installed to be fixable by another shifting element of the at least six shifting elements, a second rotary element of the second planetary gear device may be permanently connected to the input shaft and variably or selectively connected to the second rotary element of the third planetary gear device, and a third rotary element of the second planetary gear device may be permanently connected to a first rotary element of the third planetary gear device. The first rotary element of the third planetary gear device may be permanently connected to a first rotary element of the fourth planetary gear device. The first rotary element of the fourth planetary gear device may be installed to be fixable by still another shifting element of the at least six shifting elements, and a second rotary element of the fourth planetary gear device may be permanently connected to the output shaft.
[0010] According to one form of the present disclosure as set forth above, the multi-stage transmission for a vehicle can realize at least ten forward shifting stages and one reverse shifting stage with a relatively small number of parts and a simple configuration such that the engine may be operated at desired operation points, thereby improving the fuel efficiency of the vehicle, and improving the quietness of the vehicle.
[0011] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0012] In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:
[0013] FIG. 1 is a diagram illustrating a configuration of a multi-stage transmission for a vehicle according to an exemplary form of the present disclosure; and
[0014] FIG. 2 is a table showing operation modes of the transmission shown in FIG. 1 .
[0015] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
DETAILED DESCRIPTION
[0016] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like of corresponding parts and features.
[0017] The present disclosure relates to a multi-stage transmission for a vehicle.
[0018] Referring to FIGS. 1 and 2 , a multi-stage transmission for a vehicle according to one form of the present disclosure may include an input shaft “IN”; an output shaft “OUT”; a first planetary gear device “PG 1 ”, a second planetary gear device “PG 2 ”, a third planetary gear device “PG 3 ”, and a fourth planetary gear device “PG 4 ” disposed between the input shaft “IN” and the output shaft “OUT” to transmit rotary force, each of the planetary gear devices “PG 1 ”, “PG 2 ”. “PG 3 ”, and PG 4 having three rotary elements; and at least six shifting elements (e.g. clutches CL 1 -CL 6 ) connected to rotary elements of the planetary gear devices.
[0019] A first rotary element S 1 of the first planetary gear device PG 1 may be installed to be fixable by one shifting element of the at least six shifting elements. A second rotary element C 1 of the first planetary gear device PG 1 may be permanently connected to a third rotary element R 3 of the third planetary gear device PG 3 and a third rotary element R 4 of the fourth planetary gear device PG 4 . A third rotary element R 1 of the first planetary gear device PG 1 may be selectively or variably connected to a first rotary element S 2 of the second planetary gear device PG 2 and a second rotary element C 3 of the third planetary gear device PG 3 .
[0020] The first rotary element S 2 of the second planetary gear device PG 2 may be installed to be fixable, i.e. fixed in place or made stationary, by another shifting element of the at least six shifting elements, a second rotary element C 2 of the second planetary gear device PG 2 may be permanently connected to the input shaft IN and selectively connected to the second rotary element C 3 of the third planetary gear device PG 3 , and the third rotary element R 2 of the second planetary gear device PG 2 may be permanently connected to a first rotary element S 3 of the third planetary gear device PG 3 .
[0021] The first rotary element S 3 of the third planetary gear device PG 3 may be permanently connected to a first rotary element S 4 of the fourth planetary gear device PG 4 .
[0022] The first rotary element S 4 of the fourth planetary gear device PG 4 may be installed to be fixable by still another shifting element of the at least six shifting elements, and a second rotary element C 4 of the fourth planetary gear device PG 4 may be permanently connected to the output shaft OUT.
[0023] The first planetary gear device PG 1 , the second planetary gear device PG 2 , the third planetary gear device PG 3 and the fourth planetary gear device PG 4 may be sequentially arranged along the axial direction of the input shaft IN and the output shaft OUT.
[0024] More specifically, the first rotary element S 1 of the first planetary gear device PG 1 may be installed to be fixable to a transmission case CS by means of a fourth clutch CL 4 from among the at least six shifting elements. The first rotary element S 2 of the second planetary gear device PG 2 may be installed to be fixable to the transmission case CS by means of a third clutch CL 3 from among the at least six shifting elements. The first rotary element S 4 of the fourth planetary gear device PG 4 may be installed to be fixable to the transmission case CS by means of a second clutch CL 2 from among the at least six shifting elements.
[0025] Accordingly, the second clutch CL 2 , the third clutch CL 3 and the fourth clutch CL 4 function as brakes, respectively, such that the first rotary element S 4 of the fourth planetary gear device PG 4 , the first rotary element S 2 of the second planetary gear device PG 2 and the first rotary element S 1 of the first planetary gear device PG 1 may be converted to a rotatable state wherein rotation is allowed or a restrained state wherein rotation is restricted by means of the operations of the second clutch CL 2 , the third clutch CL 3 and the fourth clutch CL 4 , respectively.
[0026] The other shifting elements from among the at least six shifting elements may be configured to constitute variable connection structures between the rotary elements of the planetary gear devices.
[0027] That is, the first clutch CL 1 from among the at least six shifting elements may form a variable connection structure between the second rotary element C 2 of the second planetary gear device PG 2 and the second rotary element C 3 of the third planetary gear device PG 3 . The fifth clutch CL 5 from among the at least six shifting elements may form a variable connection structure between the third rotary element R 1 of the first planetary gear device PG 1 and the second rotary element C 3 of the third planetary gear device PG 3 . The sixth clutch CL 6 from among the at least six shifting elements may form a variable connection structure between the third rotary element R 1 of the first planetary gear device PG 1 and the first rotary element S 2 of the second planetary gear device PG 2 .
[0028] In one exemplary form, the first rotary element S 1 , the second rotary element C 1 and the third rotary element R 1 of the first planetary gear device PG 1 are a first sun gear, a first carrier and a first ring gear, respectively. The first rotary element S 2 , the second rotary element C 2 and the third rotary element R 2 of the second planetary gear device PG 2 are a second sun gear, a second carrier and a second ring gear, respectively. The first rotary element S 3 , the second rotary element C 3 and the third rotary element R 3 of the third planetary gear device PG 3 are a third sun gear, a third carrier and a third ring gear, respectively. The first rotary element S 4 , the second rotary element C 4 and the third rotary element R 4 of the fourth planetary gear device PG 4 are a fourth sun gear, a fourth carrier and a fourth ring gear, respectively.
[0029] In another form, the multi-stage transmission for a vehicle according to the present invention may include the first to fourth planetary gear devices PG 1 to PG 4 each having the three rotary elements; the six shifting elements configured to selectively provide frictional force; and eight rotary shafts connected to the rotary elements of the first to fourth planetary gear devices.
[0030] Hence, from among the eight rotary shafts, the first rotary shaft RS 1 may be the input shaft IN directly connected to the second rotary element C 2 of the second planetary gear device PG 2 . The second rotary shaft RS 2 may be directly connected to the first rotary element S 2 of the second planetary gear device PG 2 . The third rotary shaft RS 3 may be directly connected to the first rotary element S 1 of the first planetary gear device PG 1 . The fourth rotary shaft RS 4 may be directly connected to the second rotary element C 1 of the first planetary gear device PG 1 , the third rotary element R 3 of the third planetary gear device PG 3 and the third rotary element R 4 of the fourth planetary gear device PG 4 . The fifth rotary shaft RS 5 may be directly connected to the third rotary element R 1 of the first planetary gear device PG 1 . The sixth rotary shaft RS 6 may be directly connected to the second rotary element C 3 of the third planetary gear device PG 3 . The seventh rotary shaft RS 7 may be directly connected to the third rotary element R 2 of the second planetary gear device PG 2 , the first rotary element S 3 of the third planetary gear device PG 3 and the first rotary element S 4 of the fourth planetary gear device PG 4 . The eighth rotary shaft RS 8 may be the output shaft OUT directly connected to the second rotary element C 4 of the fourth planetary gear device PG 4 .
[0031] In addition, from among the six shifting elements, the first clutch CL 1 may be disposed between the first rotary shaft RS 1 and the sixth rotary shaft RS 6 . The second clutch CL 2 may be disposed between the seventh rotary shaft RS 7 and the transmission case CS. The third clutch CL 3 may be disposed between the second rotary shaft RS 2 and the transmission case CS. The fourth clutch CL 4 may be disposed between the third rotary shaft RS 3 and the transmission case CS. The fifth clutch CL 5 may be disposed between the fifth rotary shaft RS 5 and the sixth rotary shaft RS 6 . The sixth clutch CL 6 may be disposed between the second rotary shaft RS 2 and the fifth rotary shaft RS 5 .
[0032] As set forth above, the multi-stage transmission for a vehicle according to the present disclosure including the four simple planetary gear devices and the six shifting elements realizes ten forward shifting stages and one reverse shifting stage according to the operation mode table as illustrated in FIG. 2 . Since the multi-stage shifting stages of ten shifting stages can be embodied based on a relatively small number of parts and a simple configuration, the multi-stage transmission for a vehicle of the present disclosure improves fuel efficiency and quietness of a vehicle, thereby ultimately improving the marketability of the vehicle.
[0033] Although the exemplary forms of the present disclosure have been described for illustrative purposes, a person skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the present disclosure. | The present disclosure relates to a multi-stage transmission for a vehicle that includes four planetary gear devices and six shifting elements, and each of the planetary gear devices include three rotary elements selectively connected to the six shifting elements, preferably so that the multi-stage transmission provides at least ten forward shifting stages and at least one reverse shifting stage with a relatively small number of parts and a simple configuration. In this configuration, an engine may be operated at desired operation points, to improve the fuel efficiency of the vehicle and improve the quietness of the vehicle. | 5 |
RELATED APPLICATIONS
[0001] This application claims the priority of U.S. provisional patent application Ser. No. 60/458,388 filed Mar. 31, 2003.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates generally to the field of laptop computer case and more particularly to a laptop computer case adaptable to comfortably and safely cradle an operating laptop computer.
[0004] 2. Background Information
[0005] Some laptop computer users transport their laptop computer in a protective case or bag. The computer must be removed from the protective case or bag when used, leaving the laptop computer vulnerable to shock or impact damage. The protective cases or bags are not suitable for effective support of an operating laptop computer held in the lap of the user.
[0006] Laptop computers may be difficult to use when supported directly on a lap of a user. A laptop computer user's arms may tend to tire over prolonged periods of use of a lap held laptop computer without wrist support. The angle of the user's lap may make the keyboard of a laptop computer held in the user's lap slope away from the user requiring the user to adopt an uncomfortable orientation of their hands in order to access the keyboard. The bottom surface of the laptop computer may not frictionally engage the users lap making the laptop computer slide around in the users lap.
[0007] Many users try to reduce these difficulties by placing a pillow on their lap and the laptop computer on the pillow. The user may orientate the pillow to provide wrist support and support the laptop computer in an ergonomic position. The soft structure of the pillow will gradually yield precluding effective user wrist support and support of the laptop computer in an ergonomic position. The pillow also tends to insulate the laptop computer hampering the heat dissipation mechanism of the laptop computer which may result in computer damage.
[0008] What is needed is a laptop computer case that is adaptable to comfortably cradle an operating laptop computer on the user's lap without removing the laptop computer from the case. The case should place the operating laptop computer at an ergonomic inclination suitable for comfortable use by the user while providing a padded user wrist support while providing accommodations for laptop computer heat dissipation.
SUMMARY OF THE INVENTION
[0009] A laptop computer case according to the present disclosure is adaptable to comfortably cradle an operating laptop computer on the user's lap without removing the laptop computer from the case. The case places the operating laptop computer at an ergonomic inclination suitable for comfortable use by the user while providing a padded user wrist support and one or more computer accessory access doors while also providing accommodations for laptop computer heat dissipation.
[0010] The laptop computer case includes a tray having a plurality of engagement supports and a back edge. The engagement stops are adjustable relative to the tray to accommodate different computers. The laptop computer case also includes a lid connected to a hinge spacer at the back edge by a hinge and the hinge spacer is connected to the tray at the back edge by another hinge. The lid further includes a pad to engage the computer when the computer case is closed to provide shock resistance. When the computer case of the present disclosure is open as described, the pad insulates a user lap or other surface from heat generated by an operating laptop, and the pad also frictionally engages a users lap to provide a secure cradle for the operating laptop computer.
[0011] In another embodiment of the present disclosure, the laptop computer case may include a retractable carrying strap that serves as a case carrying handle in the fully retracted position. In another embodiment of the present disclosure, the laptop computer case may include an illumination device. In another embodiment of the present disclosure, the laptop computer case may include a retractable mouse pad. In still another embodiment of the present disclosure, the laptop computer case may include retractable privacy and glare reducing side screens.
[0012] These and other features and advantages of this invention will become further apparent from the detailed description and accompanying figures that follow. In the figures and description, numerals indicate the various features of the invention, like numerals referring to like features throughout both the drawings and the description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1A is a perspective view of a laptop computer case in a closed position according to the present disclosure.
[0014] [0014]FIG. 1B is a perspective view of the case of FIG. 1A in an open position.
[0015] [0015]FIG. 2 is a perspective view of the case of FIG. 1A in the open position cradling a laptop computer.
[0016] [0016]FIG. 3 is a section cut view of the case of FIG. 1B.
[0017] [0017]FIG. 4 is a perspective view of a laptop computer case in the open position according to another embodiment of the present disclosure.
[0018] [0018]FIG. 5 is a top view of the case of FIG. 1B in a closed position.
[0019] [0019]FIG. 6 is a top view of a laptop computer case in a closed position according to another embodiment of the present disclosure.
DETAILED DESCRIPTION
[0020] Referring now to FIGS. 1A and 1B, in a currently preferred embodiment of the present disclosure, case 10 includes lid 14 attached by hinge 48 to spacer 54 and spacer 54 attached by hinge 46 to tray 12 . Hinge 46 may be located on side 24 of tray 12 at any suitable location. Hinge 48 may be located on side 32 of lid 14 at any suitable location. Case 10 is in closed position 38 when spacer 54 abuts side 24 of tray 12 , and when edge 22 B of side 22 of tray 12 , abuts edge 30 B of side 30 of lid 14 . In closed position 38 case 10 can cradle and enclose a laptop computer and provide shock resistance.
[0021] Case 10 is repositioned from closed position 38 to open position 116 when lid 14 and spacer 54 are pivoted, relative to tray 12 , about hinges 48 and hinge 46 , respectively, until lid 14 is located under tray 12 as shown in FIG. 1B. In open position 116 edge 22 T of side 22 of lid 14 abuts edge 30 T of side 30 of tray 12 . A user can reposition case 10 from position 38 to position 116 without removing a cradled laptop computer. The user can operate the laptop computer without removing it from case 10 when case 10 is in position 116 .
[0022] In position 116 , the connection of tray 12 to lid 14 by hinges 46 and 48 separated by spacer 54 ergonomically inclines tray 12 at angle 136 relative to top surface 14 T of lid 14 . When in position 116 , side 30 of tray 12 is at a lower elevation relative to the user than side 24 thus creating an ergonomic incline. When tray 12 is at angle 136 relative to lid 14 an operating laptop computer cradled by case 10 is placed in a comfortable position for access by a user. Angle 136 may vary with the orientation of lid 14 relative to tray 12 . The relative orientation of lid 14 and tray 12 may be controlled by engagement elements located along edges 22 T and 30 T of lid 14 and tray 12 reapectively. Angle 136 may also be changed by changing the location of hinge 46 on side 24 , the location of hinge 48 on to side 32 and/or height 52 of spacer 54 .
[0023] Space 94 is formed when case 10 is in position 116 . Space 94 provides air access between tray 12 and lid 14 . Air access may aid heat dissipation from space 94 . Air access in space 94 changes with variances in angle 136 . Changes in angle 136 directly affect air access and may increase heat dissipation from between tray 12 and lid 14 .
[0024] Pads 70 , 72 , 74 and 76 engage and support a laptop computer within case 10 . Pads 70 , 72 , 74 and 76 are located between the legs, feet or support structure of the laptop computer and tray 12 in any suitable location relative to tray 12 and laptop computer. Pads 70 , 72 , 74 and 76 provide shock absorption, support to the laptop computer and allow air access in space 82 between tray 12 and laptop computer 118 to aid heat dissipation as shown in FIG. 3. Pads 70 , 72 , 74 and 76 maybe any suitable shape. Pads 70 , 72 , 74 and 76 may removably engage tray 12 by any suitable means of engagement. Pads 70 , 72 , 74 and 76 may be laterally relocated, relative to tray 12 by means 130 attached at location 130 ″. Means 130 may include adhesive or slotted attachment or hook and loop attachment or any suitable means of lateral relocation attachment. Lateral relocation of pads 70 , 72 , 74 and 76 permits pad locations suitable for cradling various sized laptop computers. Pads 70 , 72 , 74 and 76 height above tray 12 may be adjusted by spacer 100 to promote cradling of the laptop computer and to secure the laptop computer between pads 70 , 72 , 74 and 76 and lid 14 when case 10 is in position 38 . Spacer 100 may include any suitable means of changing height of pads 70 , 72 , 74 and 76 above tray 12 including but not limited to pads 70 , 72 , 74 and 76 of varying heights or extendable pads 70 , 72 , 74 and 76 . Pads 70 , 72 , 74 and 76 may be fabricated from rubber, plastic or other suitable material.
[0025] Liner pad 50 , lining lid 14 , provides frictional engagement, insulation and cushioning. In position 38 , liner pad 50 may frictionally engage laptop computer 118 to secure and cushion the laptop computer between liner 50 and pads 70 , 72 , 74 and 76 within closed case 10 . In position 116 , liner 50 provides cushioning between the user and lid 14 and frictionally engages the lap of the user to increase stability and reduce slippage of case 10 . Liner 50 may reduce heat transferred from case 10 to the user while in position 116 and resting in the lap of the user. Liner 50 may be fabricated from open cell foam, closed celled foam or any suitable material. Liner 50 may be attached to lid 14 by any suitable means. As shown in FIG. 3, liner 50 may extend beyond the envelope of lid 14 to minimize the likelihood of contact between a user lap and lid 14 when case 10 is in open position 116 .
[0026] Tray 12 may also include material 80 secured to surface 132 . Material 80 may conduct heat radiated from laptop computer 118 . The heat conducted into material 80 may be dissipated in spaces 94 and 82 . Material 80 may be fabricated from any suitable material. Material 80 may be attached to tray 12 by any suitable means.
[0027] A laptop computer is located in case 10 so that the computer is secured against lateral movement relative to tray 12 by engagement stops 40 , 41 42 and 44 . Engagement stops 40 , 41 , 42 and 44 may removably and adjustably engage the laptop computer using engagement elements 40 ′, 41 ′, 42 ′ and 44 ′ respectively. Engagement elements 40 ′, 41 ′, 42 ′ and 44 ′ engage any suitable engagement location such as engagement locations 40 ″, 41 ″, 42 ″, and 44 ″ respectively of tray 12 Engagement elements 40 ′, 41 ′, 42 ′ and 44 ′ permit lateral relocation, relative to tray 12 , of engagement stops 40 , 41 42 and 44 respectively. Engagement elements 40 ′, 41 ′, 42 ′ and 44 ′ may also permit vertical adjustment, relative to tray 12 , of engagement stops 40 , 41 42 and 44 respectively. Engagement elements 40 ′, 41 ′, 42 ′ and 44 ′ may include but are not limited to adhesive attachment or slotted attachment or hook and loop attachment or any suitable means lateral relocation attachment. Case 10 may be adapted to engage laptop computers of various sizes by lateral relocation of engagement stops 40 , 41 , 42 and 44 .
[0028] Support 56 is formed by side 30 and is attached by hinge 138 or other suitable means to tray 12 . Support 56 may provide support to the wrists of a user operating a cradled laptop computer when support 56 is opened and case 10 is in position 116 . Support 56 may be fabricated from plastic, titanium, carbon fiber composite or any suitable material.
[0029] Computer connector access 24 ′ may be provided through side 24 . Access 24 ′ may be a rectangular window as shown in FIG. 1B or it may be a complete removal of a portion of side 24 as shown in FIG. 4. Access 24 ′ may adopt any suitable shape and may be located in any appropriate portion of side 24 . If access 24 ′ is incorporated as a window as shown in FIG. 1B, more than one access 24 ′ may be incorporated as necessary. Care must be exercised not to remove too much of side 24 by providing access 24 ′ that the structural integrity of case 10 is endangered.
[0030] A computer access door such as door 78 may be attached by hinge 86 or other suitable means to first side 26 or second side 28 or both first side 26 and second side 28 of tray 12 or other suitable locations on case 10 . Door 78 is located and sized to allow access to a laptop computer's side mounted accessories, including but not limited to CD or floppy disk drives, without removing the laptop computer from case 10 . To close door 78 , door 78 may be pivoted until door 78 is substantially flush with the side to which it is attached.
[0031] Referring now to FIG. 2, laptop computer 118 may be cradled on tray 12 by pads 70 , 72 , 74 and 76 with first corner 124 and second corner 126 of laptop computer 118 engaged by engagement stops 44 and 42 , respectively. First rear corner 122 and second rear corner 122 ′ of laptop computer 118 are engaged by engagement stops 40 and 41 respectively.
[0032] Support 56 may include pad 110 . Pad 110 provides cushioning between the user and support 56 . Pad 110 may be fabricated from any suitable material. Support 56 provides wrist support for the user when pivoted outward from tray 12 about hinge 138 until opened to position 68 . When closed, pad 110 provides cushioning between laptop computer 118 and support 56 . Door 78 can pivot outward from tray 12 on hinge 86 to position 88 to gain access to laptop computer 118 side mounted accessories without removing laptop computer 118 from case 10 .
[0033] Referring now to FIG. 3, pads 70 , 72 , 74 and 76 may be located in any suitable location relative to tray 12 and laptop computer 118 to engage support 102 . Support 102 may be feet or legs of laptop computer 118 or other laptop computer 118 support structure. Pads 70 , 72 , 74 and 76 may be located under support 102 to promote proper load transfer into laptop computer 118 . Improper load transfer may damage laptop computer 118 . Space 82 is formed when pads 70 , 72 , 74 and 76 are placed between support 102 and tray 12 . Space 82 provides air access between laptop computer 118 and tray 12 to aid heat dissipation from laptop computer 118 . Varying the size of pads 70 , 72 , 74 and 76 will vary the amount of air access in space 82 .
[0034] Referring now to FIG. 4, in a currently preferred embodiment of the present disclosure, handle 16 may be retractably attached to lid 14 . Handle 16 may adjust to varying lengths to accommodate a grip or a shoulder strap. Handle 16 may exit lid 14 through slots 18 and 20 . Slots 18 and 20 may be located in any suitable location in lid 14 . Handle 16 may be a fabric strap or a plastic strap or a combination of beaded steel cable with a padded strap or other suitable materials or combinations of materials.
[0035] Screens 90 and 96 may provide glare reduction during operation of laptop computer 118 and a privacy shield to prevent viewing of laptop computer 118 by those near the user. Screens 90 and 96 may be removably attached to tray 12 so that a user may gain access to accessories mounted on the sides of laptop 118 by removing screens 90 and 96 from tray 12 . Screens 90 and 96 may be located in any suitable location. Strap 106 may removably engage laptop 118 so that when laptop computer 118 is open, strap 106 may be draped over the open laptop computer 118 to hold up screens 90 and 96 . During extension, screens 90 and 96 pivot about line 108 until screens 90 and 96 are extended. Screens 90 and 96 may have a fan shape or other suitable shape when extended. Screens 90 and 96 may be retracted against tray 12 and fit inside case 10 when in position 38 . Screens 90 and 96 may be opaque. Screens 90 and 96 and strap 106 may be fabricated from fabric or any suitable material.
[0036] Light 128 may be attached to screen 90 or screen 96 or laptop computer 118 or tray 12 or lid 14 or any location suitable by any suitable means to provide illumination of laptop computer 118 . Illumination from light 128 may be provided by incandescent bulb or bulbs or light emitting diode or diodes or other suitable illumination source. Illumination power may be provided by a discrete battery or a connection to the cradled laptop computer power supply or other suitable power source.
[0037] Pad 64 may be removably attached or hingeably attached or slideably attached or attached by other suitable means. Pad 64 may slideably extend or pivot out of slot 104 . Slot 104 may be located on first side 26 or second side 28 or other suitable locations on tray 12 or lid 14 . Pad 64 may be sized to provide support during operation of a computer mouse. Pad 64 may be fabricated from plastic, titanium, carbon fiber composite or any suitable material.
[0038] Referring now to FIG. 5, handle 16 may be retractably attached in any suitable location in lid 14 . Handle 16 may be attached to lid 14 at attachment 114 and spooled around pulley 66 . Biasing means 112 may apply retraction force 98 to pulley 66 which then transmits this force to handle 16 to promote handle 16 retraction into case 10 . Biasing means 112 may be provided by spring or elastic material or other suitable means. Attach point 114 and pulley 66 may be located in any suitable location in lid 14 .
[0039] Referring now to FIG. 6, in another currently preferred embodiment of the present disclosure, case 10 may include lock 92 . Lock 92 may be attached to case 10 at any suitable location. Handle 16 may include end 58 . End 58 may be removable from attach point 114 and withdrawn from lid 14 . Handle 16 may be wrapped around object 134 and removably engaged by lock 92 to lock case 10 to object 134 when case 10 is in closed position 38 . Lock 92 may lock lid 14 to tray 12 .
[0040] Having now described the invention in accordance with the requirements of the patent statutes, those skilled in this art will understand how to make changes and modifications in the present invention to meet their specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention as set forth in the following claims and their legal equivalents. | A laptop computer case according to the present disclosure is adaptable to comfortably cradle an operating laptop computer on the user's lap without removing the laptop computer from the case. The case places the operating laptop computer at an ergonomic inclination suitable for comfortable use by the user while providing a padded user wrist support while providing accommodations for laptop computer heat dissipation. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. | 0 |
RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/387,674, filed Mar. 13, 2003, now issued as U.S. Pat. No. 7,329,281, which is a continuation of U.S. patent application Ser. No. 09/966,766, filed Sep. 28, 2001, now issued as U.S. Pat. No. 6,554,862, which is a continuation-in-part of U.S. patent application Ser. No. 09/789,398, filed Feb. 20, 2001, now abandoned, which is a continuation of U.S. patent application Ser. No. 09/304,885, filed May 4, 1999, now abandoned, which is a continuation of Ser. No. 08/756,413, filed Nov. 27, 1996, now issued as U.S. Pat. No. 5,899,938.
FIELD OF THE INVENTION
This invention relates to medical apparatus and methods in general, and more particularly to apparatus and methods for reconstructing ligaments.
BACKGROUND OF THE INVENTION
Ligaments are tough bands of tissue which serve to connect the articular extremities of bones, or to support or retain organs in place within the body. Ligaments are typically composed of coarse bundles of dense white fibrous tissue which are disposed in a parallel or closely interlaced manner, with the fibrous tissue being pliant and flexible, but not significantly extensible.
In many cases, ligaments are torn or ruptured as a result of accidents. As a result, various procedures have been developed to repair or replace such damaged ligaments.
For example, in the human knee, the anterior and posterior cruciate ligaments (i.e., the ACL and PCL) extend between the top end of the tibia and the bottom end of the femur. The ACL and PCL cooperate, together with other ligaments and soft tissue, to provide both static and dynamic stability to the knee. Often, the anterior cruciate ligament (i.e., the ACL) is ruptured or torn as a result of, for example, a sports-related injury. Consequently, various surgical procedures have been developed for reconstructing the ACL so as to restore normal function to the knee.
In many instances, the ACL may be reconstructed by replacing the ruptured ACL with a graft ligament. More particularly, with such procedures, bone tunnels are typically formed in the top end of the tibia and the bottom end of the femur, with one end of the graft ligament being positioned in the femoral tunnel and the other end of the graft ligament being positioned in the tibial tunnel. The two ends of the graft ligament are anchored in place in various ways known in the art so that the graft ligament extends between the femur and the tibia in substantially the same way, and with substantially the same function, as the original ACL. This graft ligament then cooperates with the surrounding anatomical structures so as to restore normal function to the knee.
In some circumstances the graft ligament may be a ligament or tendon which is harvested from elsewhere in the patient; in other circumstances the graft ligament may be a synthetic device. For the purposes of the present invention, all of the foregoing can be collectively referred to as a “graft ligament”, “graft material” or “graft member.”
As noted above, the graft ligament may be anchored in place in various ways. See, for example, U.S. Pat. No. 4,828,562, issued May 9, 1989 to Robert V. Kenna; U.S. Pat. No. 4,744,793, issued May 17, 1988 to Jack E. Parr et al.; U.S. Pat. No. 4,755,183, issued Jul. 5, 1988 to Robert V. Kenna; U.S. Pat. No. 4,927,421, issued May 22, 1990 to E. Marlowe Goble et al.; U.S. Pat. No. 4,950,270, issued Aug. 21, 1990 to Jerald A. Bowman et al.; U.S. Pat. No. 5,062,843, issued Nov. 5, 1991 to Thomas H. Mahony, III; U.S. Pat. No. 5,147,362, issued Sep. 15, 1992 to E. Marlowe Goble; U.S. Pat. No. 5,211,647, issued May 18, 1993 to Reinhold Schmieding; U.S. Pat. No. 5,151,104, issued Sep. 29, 1992 to Robert V. Kenna; U.S. Pat. No. 4,784,126, issued Nov. 15, 1988 to Donald H. Hourahane; U.S. Pat. No. 4,590,928, issued May 27, 1986 to Michael S. Hunt et al.; and French Patent Publication No. 2,590,792, filed Dec. 4, 1985 by Francis Henri Breard.
Despite the above-identified advances in the art, there remains a need for a graft ligament anchor which is simple, easy to install, and inexpensive to manufacture, while providing secure, trouble-free anchoring of the graft ligament, typically in the knee joint of a mammal.
OBJECTS OF THE INVENTION
Accordingly, one object of the present invention is to provide an improved graft ligament anchor which is relatively simple in construction and therefore inexpensive to manufacture, relatively easy to handle and install, and reliable and safe in operation.
Another object of the present invention is to provide an improved method for attaching a graft ligament to a bone.
SUMMARY OF THE INVENTION
These and other objects of the present invention are addressed by the provision and use of a novel graft ligament anchor comprising graft ligament engagement means for disposition in an opening in a bone, such that a wall of the graft ligament engagement means resides adjacent to at least one graft ligament disposed in the opening, and locking means for disposition in the opening in the bone and at least partially engageable with the graft ligament engagement means. The elements of the graft ligament anchor are adapted such that movement of the locking means in the opening in the bone causes at least a part of the locking means to engage the graft ligament engagement means so as to urge the graft ligament engagement means, and hence the portion of the graft ligament disposed adjacent thereto, toward a wall of the opening in the bone, whereby to secure the graft ligament to the wall of the opening.
In use, an opening is made in the bone, and the graft ligament and the graft ligament engagement means are inserted into the opening, with a portion of the graft ligament being disposed alongside a wall of the graft ligament engagement means. In accordance with the present invention, the locking means are also positioned in the opening in the bone, alongside the graft ligament engagement means, with the locking means being separated from the graft ligament by a portion of the graft ligament engagement means. The method further includes moving the locking means in the opening in the bone so as to cause at least a portion thereof to urge the graft ligament engagement means, and hence the portion of the graft ligament disposed adjacent thereto, toward a wall of the opening, whereby to secure the graft ligament to the wall of the opening.
In one aspect of the invention, a graft fixation device for fixing a graft member within a bone tunnel includes a radially expandable sheath having a side wall with at least one structurally weakened fracture region extending longitudinally along a length of the sheath in the side wall. The radially expandable sheath is sized to fit within a bone tunnel so that a graft member may be accommodated between a wall of a bone tunnel and an outer surface of the radially expandable sheath. A sheath expander is disposable in a central lumen of the radially expandable sheath to radially expand the sheath so as to fix the graft member within the bone tunnel. The structurally weakened fracture region is adapted to fracture upon radial expansion of the sheath to allow varying amounts of radial expansion.
In specific embodiments of this aspect of the invention, a number of longitudinal side wall segments can be provided, the segments being connected by longitudinal fracture regions. The side wall segments can also have concave outer surfaces so that each segment can capture a portion of graft material between its outer surface and the bone tunnel wall. In a further embodiment, the segments can be longitudinally divided into subsegments connected by longitudinal flexion regions.
In another aspect of the invention, a graft fixation device for fixing a graft member within a bone tunnel includes a radially expandable sheath having a side wall comprising a plurality of longitudinal side wall segments separated by convex longitudinal flex regions having convex outer surfaces, the radially expandable sheath being sized to fit within a bone tunnel and defining a central lumen. In this aspect, the side wall segments are flexible and have a concave outer surface adapted to enclose a graft member between the concave outer surface and a bone tunnel wall. A sheath expander is disposable in the central lumen of the radially expandable sheath to flex the convex longitudinal flex regions and the flexible concave wall segments to radially expand the sheath so as to fix a graft member within a bone tunnel.
In specific embodiments of this aspect, the side wall segments may include rigid longitudinal subsegments connected by longitudinal flex regions to provide flexing within the segments. In addition, convex longitudinal flex regions may be configured to flex, but then fracture to allow further radial expansion of the sheath.
Graft fixation devices of the invention allow a wider variety of materials to be used to form the radially expanding sheath and can also allow a single sized sheath to be used with a larger variety of bone tunnel and expander sizes.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which are to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein:
FIG. 1 is a diagrammatic sectional view of one form of graft ligament anchor made in accordance with the present invention;
FIG. 2 is similar to FIG. 1 , but shows the graft ligament anchor components in different operating positions;
FIG. 3 is similar to FIG. 1 , but shows an alternative embodiment of the present invention;
FIG. 4 is a diagrammatic sectional view of another form of graft ligament anchor made in accordance with the present invention;
FIG. 5 is similar to FIG. 4 , but shows the graft ligament anchor components in different operating positions;
FIG. 6 is a diagrammatic sectional view of another form of graft ligament anchor made in accordance with the present invention;
FIG. 7 is a diagrammatic sectional view of still another form of graft ligament anchor made in accordance with the present invention;
FIG. 8 is a diagrammatic sectional view of yet another form of graft ligament anchor made in accordance with the present invention;
FIG. 9 is a perspective view of one of the components of the graft ligament anchor shown in FIG. 8 ;
FIG. 10 is a diagrammatic sectional view of still another form of graft ligament anchor made in accordance with the present invention;
FIG. 11 is a diagrammatic view of still another form of graft ligament anchor made in accordance with the present invention;
FIG. 12 is a diagrammatic sectional view of yet another form of graft ligament anchor made in accordance with the present invention;
FIG. 13 is similar to FIG. 12 , but shows the graft ligament anchor components in different operating conditions;
FIG. 13A is a diagrammatic sectional view of still another form of ligament anchor made in accordance with the present invention;
FIG. 14 is a top plan view of still another form of graft ligament anchor made in accordance with the present invention;
FIG. 15 is a side view, in section, of the graft ligament anchor shown in FIG. 14 ;
FIG. 16 is a side view showing the graft ligament anchor of FIGS. 14 and 15 securing a graft ligament to a bone;
FIG. 17 is similar to a portion of FIG. 16 , but showing components of the graft ligament anchor and graft ligament of FIG. 16 in alternative positions;
FIG. 18 is a top plan view of yet another form of graft ligament anchor made in accordance with the present invention;
FIG. 19 is a side view, in section, of the graft ligament anchor shown in FIG. 18 ;
FIG. 20 is a diagrammatic sectional view of still another form of graft ligament anchor made in accordance with the present invention;
FIG. 21 is a perspective view of a component of the graft ligament anchor shown in FIG. 20 ;
FIG. 22 is a diagrammatic sectional view of still another form of graft ligament anchor made in accordance with the present invention;
FIG. 23 is a perspective view of components of the graft ligament anchor of FIG. 22 ;
FIG. 24 is a perspective view of a radially expandable sheath in accordance with a further embodiment of the invention;
FIG. 25A is a side view of the sheath of FIG. 24 ; FIG. 25B is a cross-sectional view of the sheath of FIG. 25A taken along line A-A′ in an unexpanded state;
FIG. 26 is an exploded view of the radially expandable sheath of FIG. 24 and a sheath expander;
FIG. 27 is a cross-sectional view of the radially expandable sheath of FIG. 24 with graft material placed in a bone tunnel prior to fixation; and
FIG. 28 is a cross-sectional view of the sheath and graft material of FIG. 27 in after fixation within the bone tunnel.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIG. 1 , it will be seen that one illustrative embodiment of the present invention includes a graft ligament engagement means 20 comprising a deformable sleeve 22 , preferably formed out of metal or plastic, and adapted to be inserted into an opening 24 formed in a bone B. One or more graft ligaments 28 are disposed alongside an interior wall 30 of sleeve 22 .
The embodiment illustrated in FIG. 1 further includes locking means 32 , which may be a pivotally movable rocker arm 34 , which may be provided with a slot 36 for receiving a key member (not shown) for turning rocker arm 34 .
Referring to FIG. 2 , it will be seen that turning rocker arm 34 enables a portion of the rocker arm to impinge upon an exterior surface 40 of sleeve 22 so as to force sleeve 22 , and hence graft ligaments 28 contained therein, toward sidewall 38 of opening 24 , whereby to secure sleeve 22 and graft ligaments 28 between opening sidewall 38 and locking means 32 .
In operation, opening 24 is first made in bone B and then graft ligaments 28 and graft ligament engagement means 20 are inserted into opening 24 , with graft ligaments 28 being disposed alongside a first wall, i.e., the interior wall 30 , of sleeve 22 . Locking means 32 are inserted into opening 24 alongside the exterior surface 40 of sleeve 22 . Locking means 32 are thus separated from graft ligaments 28 by graft ligament engagement means 20 , i.e., sleeve 22 . As noted above, movement of locking means 32 causes at least a portion thereof to engage sleeve 22 and to crimp the sleeve inwardly upon graft ligaments 28 , and to push both sleeve 22 and graft ligaments 28 against sidewall 38 of opening 24 .
If it is desired to thereafter release graft ligaments 28 , rocker arm 34 may be moved back to the position shown in FIG. 1 . To this end, graft ligament engagement means 20 preferably are formed out of a resilient material, whereby engagement means 20 can return to substantially the same position shown in FIG. 1 when locking means 32 return to the position shown in FIG. 1 .
If desired, substantially all of sleeve 22 can be formed so as to be deformable; alternatively, some of sleeve 22 can be formed so as to be rigid. By way of example, the portion of sleeve 22 contacted by locking means 32 can be formed so as to be substantially rigid.
Graft ligaments 28 may comprise natural or synthetic graft ligament material, and the anchor can be used to attach natural or synthetic graft ligaments and/or tendons to bone. Sleeve 22 preferably is provided with inwardly-extending protrusions 42 , such as spikes 44 , for securely retaining graft ligaments 28 therein.
Locking means 32 may be a rocker arm type, such as the rocker arm member 34 shown in FIGS. 1 and 2 , or a generally conically-shaped expansion plug 46 , as shown in FIG. 3 , with the expansion plug preferably being threaded such that as the plug is screwed into place, an increasing diameter of the plug engages sleeve 22 in a wedge-like manner so as to force the sleeve against interior wall 38 of opening 24 .
In FIG. 4 , there is shown an alternative embodiment in which graft ligaments 28 are disposed alongside exterior wall 40 of sleeve 22 , and locking means 32 is disposed within sleeve 22 . With this embodiment, locking means 32 operate to engage interior wall 30 of the sleeve ( FIG. 5 ), whereby to force graft ligaments 28 against sidewall 38 of opening 24 . Again, locking means 32 may be a rocker arm type, such as the rocker arm member 34 shown in FIGS. 4 and 5 , or may be an expansion plug 46 , preferably threaded, of the sort shown in FIG. 3 . With the embodiment shown in FIGS. 4 and 5 , sleeve 22 may be provided with protrusions 42 (in the form of spikes 44 , for example) on the exterior wall 40 thereof for engagement with graft ligaments 28 . In many instances, it is beneficial to provide at least two discrete graft ligaments 28 and, in such cases, it is preferable that the graft ligaments be disposed on substantially opposite diametric sides of the sleeve, as shown in FIGS. 4 and 5 .
In FIG. 6 , there is shown an embodiment similar to that shown in FIGS. 4 and 5 , but provided with an expandable sleeve 22 A, rather than a deformable metal or plastic sleeve 22 as shown in FIGS. 1-5 . Sleeve 22 A may be formed out of an elastomeric material, and it is expanded radially outwardly by engagement with a centrally disposed locking means 32 (preferably in the form of a threaded expansion plug 46 ) so as to force graft ligaments 28 outward into a secured position between sleeve 22 A and opening sidewall 38 .
In operation, the embodiments shown in FIGS. 4-6 function similarly to the embodiments shown in FIGS. 1-3 in attaching graft ligaments 28 to bone B. Opening 24 is first made in bone B. Graft ligaments 28 and graft ligament engagement means 20 (in the form of sleeve 22 or sleeve 22 A) are inserted into opening 24 , with graft ligaments 28 disposed alongside exterior wall 40 of the graft ligament engagement means, i.e., alongside the exterior wall 40 of sleeve 22 or sleeve 22 A. Locking means 32 (in the form of a rocker arm member 34 or a threaded expansion plug 46 ) are inserted axially into the sleeve, alongside interior wall 30 of the sleeve. Locking means 32 are thus separated from the graft ligaments 28 by the sleeve ( 22 or 22 A). Then locking means 32 are manipulated so as to engage the sleeve ( 22 or 22 A) and thereby urge the sleeve, and hence graft ligaments 28 , toward opening sidewall 38 , whereby to secure the sleeve and graft ligaments to the wall of the opening.
If and when it is desired to adjust tension on graft ligaments 28 , locking means 32 may be backed off, that is, if locking means 32 comprise the rocker arm type cam member 34 , the arm need only be rotated 90° from the positions shown in FIGS. 2 and 5 , to return to the positions shown, respectively, in FIGS. 1 and 4 ; if, on the other hand, locking means 32 comprise expansion plug 46 , the plug need only be unscrewed or otherwise axially withdrawn so as to release the securing of the graft ligaments.
Referring next to FIG. 7 , it will be seen that in an alternative embodiment, graft ligament engagement means 20 comprises plate means 48 which are movable transversely within the bone opening. As in the embodiments previously described, graft ligaments 28 are disposed alongside a wall 50 of graft ligament engagement means 20 , which in this instance is a first major surface of plate means 48 . Graft ligament engagement means 20 are disposed between graft ligaments 28 and locking means 32 . Locking means 32 may be, as in the above-described embodiments, an expansion plug 46 (as shown in FIG. 7 ), or locking means 32 may be a rocker arm type of cam member 34 (of the sort shown in FIGS. 1 , 2 , 4 and 5 ). Locking means 32 are adapted to impinge upon a second major surface 52 of plate means 48 . Plate means 48 , in the embodiment shown in FIG. 7 , comprises a single plate 54 having, on first major surface 50 thereof, one or more concavities 56 for nesting one or more graft ligaments 28 , respectively.
In the attachment of one or more graft ligaments 28 to a bone B, using the embodiment of FIG. 7 , locking means 32 are manipulated so as to bear against plate 54 so as to move plate 54 into engagement with graft ligaments 28 , and thence to further move plate 54 so as to secure the graft ligaments against sidewall 38 of opening 24 .
Referring next to FIG. 8 , it will be seen that locking means 32 may comprise the threaded expansion plug 46 deployed partly in opening 24 and threaded partly into bone B, thus serving as a so-called interference screw. With this arrangement, plug 46 is thereby (i) in part along its length disposed in opening 24 , protruding into the opening from opening wall 38 , and (ii) in part along its length threadedly engaged with bone B. Screwing in plug 46 causes the plug to engage plate 54 which, in turn, compacts one or more graft ligaments 28 against wall 38 of opening 24 .
In lieu of, or in addition to, the aforementioned concavities 56 shown in FIG. 7 , plate 54 may be provided with gripper ribs 58 for engaging graft ligaments 28 , as shown in FIGS. 8 and 9 .
In FIG. 10 , it is shown that plate means 48 may include first and second plates 60 , 62 , each having a wall 50 facing one or more graft ligaments 28 , and a wall 52 facing locking means 32 . Plates 60 , 62 may be joined together by a link 64 which may be molded integrally with plates 60 , 62 so as to form a so-called “living hinge” link. Locking means 32 are depicted in FIG. 10 as a rocker arm type of cam member 34 , but it will be appreciated that an expansion plug type of locking means (e.g., a plug 46 such as that shown in FIGS. 3 , 6 and 7 ) might also be used.
In operation, rotative movement of rocker arm 34 (or axial movement of expansion plug 46 ) causes plates 60 , 62 to move outwardly from each other so as to urge graft ligaments 28 against wall 38 of opening 24 . Walls 50 of plates 60 , 62 may be provided with concavities 56 , as shown in FIG. 10 , or with ribs 58 of the sort shown in FIG. 9 , or both.
Referring next to FIG. 11 , it will be seen that still another embodiment of the present invention includes, as graft ligament engagement means 20 , a V-shaped strip 94 , preferably made out of a resilient metal or plastic material. An end portion 96 of a graft ligament 28 is disposed between first and second leg portions 98 , 100 of V-shaped strip 94 , and graft ligament 28 extends alongside an exterior surface 102 of second leg portion 100 . Locking means 32 comprise a threaded expansion plug 46 disposed partly in opening 24 and partly in bone B, along sidewall 38 of opening 24 , in a manner similar to the disposition of threaded expansion plug 46 shown in FIG. 8 .
Upon screwing in expansion plug 46 , the expansion plug engages first leg 98 of graft ligament engagement means 20 (i.e., the V-shaped strip 94 ) to force first leg 98 to close upon second leg 100 with the graft ligament end portion 96 sandwiched therebetween and, upon further screwing in of threaded expansion plug 46 , to force graft ligament engagement means 20 and graft ligament 28 against wall 38 of opening 24 . To release graft ligament 28 , an operator need only back out expansion plug 46 .
When attaching a graft ligament to a bone with the graft ligament anchor shown in FIG. 11 , an opening is first drilled, or otherwise made, in the bone. Then the V-shaped strip 94 is inserted into the opening, with a nose portion 104 thereof pointed inwardly of the bone. Next, end portion 96 of graft ligament 28 is inserted between first and second leg portions 98 , 100 of V-shaped strip 94 . Threaded expansion plug 46 is then inserted into opening wall 38 such that a first portion 106 of the lengthwise extent of plug 46 is disposed in opening 24 , and second portion 108 of the lengthwise extent of plug 46 is threadedly engaged with bone B. Expansion plug 46 is then screwed further down so as to cause plug 46 to engage first leg 98 of V-shaped strip 94 so as to secure graft ligament end portion 96 in V-shaped strip 94 , and then screwed down further to wedge strip 94 and graft ligament 28 against wall 38 of opening 24 .
Still referring to FIG. 11 , it is to be appreciated that bone opening 24 may be formed with a constant diameter throughout its length or, if desired, may be formed with two different diameters along its length, in the manner shown in FIG. 11 , so as to form an annular shoulder 110 within the bone opening. The provision of an annular shoulder 110 can be very helpful in ensuring that the graft ligament anchor is prevented from migrating further into bone B, even if graft ligament 28 should thereafter be subjected to substantial retraction forces.
In a modification (not shown) of the FIG. 11 embodiment, the expansion plug 46 may be entered alongside graft ligament 28 and second leg portion 100 of strip 94 . In this modified version, the expansion plug 46 operates as described above, except that expansion plug 46 engages graft ligament 28 and forces strip first leg 98 against wall 38 of opening 24 .
Looking next at FIGS. 12 and 13 , yet another form of graft ligament anchor is disclosed. This graft ligament anchor is similar to the embodiment shown in FIG. 6 , except that the expandable sleeve 22 B is in the form of a cylindrical coil. Sleeve 22 B is formed out of an elastomeric material and is expanded radially outwardly by engagement with a centrally disposed locking means 32 (preferably an axially-movable threaded expansion plug 46 ) so as to force graft ligament 28 outward into a secured position between sleeve 22 B and bone B.
In FIG. 13A there is shown an embodiment similar to that shown in FIG. 10 , but in which the first and second plates 60 , 62 are discrete plates and not connected to each other. With this arrangement, locking means 32 is inserted into a central recess 74 defined by plate walls 52 , and may comprise either an expansion plug 46 of the type shown in FIGS. 6 and 7 or a rocker arm type of cam member 34 of the type shown in FIGS. 1 and 2 .
Looking next at FIGS. 14 and 15 , another graft ligament anchor 200 is shown. Anchor 200 includes graft ligament engagement means 20 comprising a flat plate 201 , a pair of through-holes 202 , 204 and a threaded through-hole 206 . In use, and looking now at FIGS. 14 , 15 and 16 , the free end 96 of graft ligament 28 is passed downward through hole 202 and then back upward again through hole 204 , and then a screw 208 is used to secure anchor 200 to the wall 210 of the bone opening by threading the shank of screw 208 through hole 206 , through graft ligament 28 , and into bone B. This will cause screw 208 and plate 201 to securely attach graft ligament 28 to bone B.
As shown in FIG. 17 , alternatively, graft ligament 28 may be passed upwardly through hole 202 and downwardly through hole 204 . Screw 208 is then threaded through hole 206 and graft ligament 28 and into bone B. Thus, as in the embodiment shown in FIG. 16 , screw 208 and plate 201 secure graft ligament 28 to bone B.
FIGS. 18 and 19 show another graft ligament anchor 200 A. Graft ligament anchor 200 A is similar to graft ligament anchor 200 , except that it includes a plurality of spikes 212 for projecting into wall 210 ( FIG. 16 ) of bone B when the graft ligament anchor is deployed against the bone. Also, graft ligament anchor 200 A has an enlarged configuration 214 in the region of through-hole 206 A, as shown in FIG. 18 .
Referring next to FIG. 20 , there is shown a still further alternative embodiment of graft ligament anchor, similar to that shown in FIG. 7 , wherein graft ligament engagement means 20 comprises plate means 48 formed in a U-shaped configuration ( FIG. 21 ) movable transversely within bone opening 24 . At least one graft ligament 28 is disposed alongside wall 50 of graft ligament engagement means 20 , which in this instance is a first major surface of plate means 48 . Graft ligament engagement means 20 is disposed between graft ligament 28 and locking means 32 . Locking means 32 may be an expansion plug 46 , as shown in FIG. 20 and in FIG. 7 , or a rocker arm type cam member 34 , as shown in FIG. 1 , or an interference screw type expansion plug 46 , as shown in FIG. 11 , or a transverse screw 208 , as shown in FIG. 16 .
In attachment of one or more graft ligaments 28 to a bone B, using the embodiment of FIG. 20 , locking means 32 is manipulated so as to bear against a second major surface 52 of plate means 48 and thereby move plate means 48 into engagement with graft ligament 28 , and thence to drive free ends 49 of plate means 48 into sidewall 38 of opening 24 so as to fasten graft ligament 28 to sidewall 38 and, thereby, to bone B.
Referring to FIGS. 22 and 23 , there is shown still another alternative embodiment of graft ligament anchor including a tubular member 300 , open at first and second ends 302 , 304 and having an opening 306 in the sidewall thereof. Otherwise, the graft ligament anchor of FIG. 22 is similar to the graft ligament anchor of FIG. 20 , described hereinabove.
In attachment of one or more graft ligaments 28 to a bone, using the embodiment of FIGS. 22 and 23 , locking means 32 are manipulated to bear against second major surface 52 of plate means 48 so as to move plate means 48 through tubular member opening 306 and into engagement with graft ligament 28 , and thence further to drive free ends 49 of plate means 48 into sidewall 38 of opening 24 , whereby to fasten tubular member 300 and graft ligament 28 to sidewall 38 and, thereby, to bone B. In this embodiment, and in the embodiments shown in FIGS. 1-3 , an operator may fasten the graft ligament to the bone without the graft ligament contacting the bone. The tubular member 300 preferably is of a plastic or metallic material and the plate means 48 is of a plastic or metallic material. In the embodiments shown in FIGS. 20 and 22 , the plate means 48 may be provided with interior teeth 47 for gripping graft ligament 28 .
A further embodiment of the present invention is illustrated in FIG. 24-FIG . 28 . FIG. 24 shows a perspective view of a selectively radially expandable sheath 400 having a side wall 401 and defining a central lumen 450 . As illustrated in FIG. 27 , sheath 400 is sized to fit within a bone tunnel 600 ( FIG. 27 ) while capturing graft material 28 between an outer surface of the sheath and an inner wall of bone tunnel 600 . Central lumen 450 is sized to accept a sheath expanding element (such as sheath expanding element 700 ( FIG. 26 ) or locking means 32 (see, e.g., FIG. 10 )) that expands the sheath radially to fix graft material 28 within bone tunnel 600 as illustrated in FIG. 28 .
Referring again to FIG. 24 , sheath 400 can include a proximal or “sheath expander lead-in” end region 403 that is tapered to ease insertion of a sheath expander into central lumen 450 . Lead-in region 403 may have proximal cut-out areas 406 to facilitate radial expansion in the proximal cross-section of sheath 400 . Central lumen 450 may also include female threads 407 on an inside surface 408 of side wall 401 to facilitate a threaded engagement with a threaded sheath expander (such as tapered screw sheath expander 700 ( FIG. 26 )) in central lumen 450 . Lead-in region 403 of sheath 400 can also include a tab 1000 which may serve as a stop to prevent any overinsertion of sheath 400 into a bone tunnel. The outer diameter of side wall 401 may also taper from a larger diameter in lead-in region 403 to a smaller diameter at distal tip 409 to provide a gradual transition in the amount of ultimate compressive load being applied to graft members 28 during insertion. As with lead-in region 403 , distal tip 409 may have cut-out areas 452 to facilitate radial expansion in the distal cross-section of sheath 400 . A portion of the outside surface of side wall 401 may include ribs 402 , protrusions or other similar features which roughen the outside surface and engage with either or both the wall 600 ( FIGS. 27 and 28 ) of a bone tunnel and graft material 28 when sheath 400 is expanded.
As illustrated in the cross-sectional view of FIG. 25B , side wall 401 of sheath 400 is divided into four longitudinal side wall segments 405 , each having concave outer surfaces which provide regions 410 , 420 , 430 , and 440 where graft material may be disposed between the side wall segments and bone tunnel wall 600 (as further illustrated in FIG. 27 ). In accordance with the principles of the invention, a sheath expander (such as tapered screw sheath expander 700 ) may be inserted into central lumen 450 of sheath 400 to deform non-circular side wall 401 toward a circular geometry to conform with an outer diameter of expander 700 . Sheath 400 includes a number of features configured to accommodate this deformation.
In particular, sheath 400 can include one or more structurally weakened fracture regions 490 extending longitudinally along a length of side wall 401 . As used herein, structurally weakened refers to a feature that can allow flexion and/or fracture side wall 401 , in some instances allowing the wall to flex as if it were hinged (and it is further contemplated that a hinge of any type could be a structurally weakened region). In a preferred embodiment, fracture regions 490 extend substantially along or entirely along the length of side wall 401 and may incorporate proximal and distal cut outs 406 and 452 . Further, fracture regions 490 may be configured to flex to allow some radial expansion of the sheath before fracturing to allow even further radial expansion of sheath 400 (post fracture expansion is illustrated in FIG. 28 ). Fracture regions 490 may be formed by thinning the material of side wall 401 longitudinally in the region of desired fracture, and in one embodiment, may be a longitudinal groove cut into side wall 401 .
In the illustrative embodiment of FIG. 25B , sheath 400 comprises four longitudinal side wall segments 405 that circumscribe central lumen 450 , each of the longitudinal side wall segments being connected to its neighbors by the four structurally weakened longitudinal fracture regions 490 . While this configuration may be preferred in the situation that the graft material being fixed to a bone tunnel can easily be separated into four components, a person of ordinary skill in the art will recognize that more or fewer side wall segments and structurally weakened regions can be provided to adapt sheath 400 to different fixation requirements. In addition, central lumen need not be fully circumscribed by side wall segments having concave outer surfaces. For example, half of side wall 401 could take the form of one half of a cylinder generally conforming to the shape of the bone tunnel, while the other half of side wall 401 could comprise two or more side wall segments 405 having concave outer surfaces, the side wall segments 405 being connected to each other and to the half cylinder portion by longitudinal fracture regions. Such a configuration may be preferable where a surgeon wishes to fix the graft material to one side of a bone tunnel (such as an anterior or posterior side) at the expense of fixation to the opposed side.
Concave side wall segments 405 may also include longitudinal flexion regions 480 to aid in allowing the wall segments to expand radially outward to fix graft material to a bone tunnel wall. As with fracture regions 490 , flexion regions can extend substantially along or entirely along the length of side wall 401 . Flexion regions 480 may also be formed by thinning the material of side wall 401 longitudinally in the region of desired flexion, and in one embodiment, may be a longitudinal groove cut into side wall 401 .
In the illustrated embodiment, each concave side wall segment 405 includes two longitudinal flexion regions 480 which divide the wall segments into three relatively rigid longitudinal subsegments connected by the two longitudinal flexion regions. A person of ordinary skill in the art will recognize that a sheath of the invention could be formed using only one flexion region within a wall segment or by using more than two such flexion regions within the spirit of the invention.
In one embodiment of the invention, longitudinal fracture regions 490 (which preferably flex before fracturing) have a convex outer surface and act as “outer hinges,” while longitudinal flexion regions 480 act as “inner hinges” to allow a first measure of radial expansion toward a circular geometry by flexing of these inner and outer hinges. This first measure of radial expansion can be followed by fracture of one or more of the longitudinal fracture regions 490 to provide a second measure of radial expansion beyond the first measure.
The provision of inner 480 and outer 490 hinges in sheath 400 provides resiliency and malleability to side wall 401 and allows for the option of using stiffer, stronger starting stock for sheath 400 than would otherwise be possible. Both inner hinge flexion regions 480 and outer hinge fracture regions 490 serve as concentrated bending areas. However, fracture regions 490 are preferably configured to act as regions of maximum stress as there is less or no graft material 28 to counterbalance radial stresses. If side wall 401 is to fail at any location for lack of ductility or strength, this embodiment allows for breakage to occur at fracture regions 490 , further illustrated in FIG. 28 after fracture as edges 500 . Flexion regions 480 , as thinned regions, are preferably configured to add flexibility to side wall segments 405 and to facilitate increase of the radius of curvature of the concave outer surface of segments 405 without undue risk of breakage on segments 405 which must carry a compressive load to graft material 28 . Accordingly, fracture regions 490 would preferably have a geometry such that the local material stresses during expansion of sheath 400 are always greater than the local stresses at flexion regions 480 so that material rupture will always be directed along the path of fracture regions 490 . This means of controlled rupture ensures that sheath 400 will remain biomechanically functional since the rupture will then occur away from ligament accommodating regions 410 , 420 , 430 , 440 .
Further, such controlled rupture along fracture regions 490 facilitates use of a wider variety of expander sizes, including the use of expanders having an outer diameter or circumference at least as large as the diameter or circumference of sheath 400 . In this way, a single sheath size may be stocked for a wide variety of procedures and intended bone tunnel sizes. In one embodiment, sheath 400 may be provided in a kit to surgeons in which a plurality of expanders having different sizes are provided for use with a single size sheath.
The inclusion of fracture regions 490 and/or flexion regions 480 widen the choice of available sheath materials to include, for example, biocompatible bioabsorbable polymers selected from the group consisting of aliphatic polyesters, polyorthoesters, polyanhydrides, polycarbonates, polyurethanes, polyamides and polyalkylene oxides. Sheath 400 may also be formed from absorbable glasses and ceramics (possibly comprising calcium phosphates and other biocompatible metal oxides (i.e., CaO)). Sheath 400 may also be formed from metals; it can comprise combinations of metals, absorbable ceramics, glasses or polymers.
In further embodiments, the expandable sheath may be fabricated from aliphatic polymer and copolymer polyesters and blends thereof. Suitable monomers include but are not limited to lactic acid, lactide (including L-, D-, meso and D,L mixtures), glycolic acid, glycolide, E-caprolactone, p-dioxanone (1,4-dioxan-2-one), trimethylene carbonate (1,3-dioxan-2-one), delta-valerolactone, beta-butyrolactone, epsilon-decalactone, 2,5-diketomorpholine, pivalolactone, alpha, alpha-diethylpropiolactone, ethylene carbonate, ethylene oxalate, 3-methyl-1,4-dioxane-2,5-dione, 3,3-diethyl-1,4-dioxan-2,5-dione, gamma-butyrolactone, 1,4-dioxepan-2-one, 1,5-dioxepan-2-one, 6,6-dimethyl-dioxepan-2-one, 6,8-dioxabicycloctane-7-one and combinations thereof. These monomers generally are polymerized in the presence of an organometallic catalyst and an initiator at elevated temperatures. The organometallic catalyst may be tin based, (e.g., stannous octoate), and may be present in the monomer mixture at a molar ratio of monomer to catalyst ranging from about 10,000/1 to about 100,000/1. The aliphatic polyesters are typically synthesized in a ring-opening polymerization process. The initiator is typically an alkanol (including diols and polyols), a glycol, a hydroxyacid, or an amine, and is present in the monomer mixture at a molar ratio of monomer to initiator ranging from about 100/1 to about 0.5000/1. The polymerization typically is carried out at a temperature range from about 80° C. to about 240° C., preferably from about 100° C. to about 220° C., until the desired molecular weight and viscosity are achieved.
It is to be understood that the present invention is by no means limited to the particular constructions and methods herein disclosed and/or shown in the drawings, but also comprises any modifications or equivalents within the scope of the claims | A graft ligament anchor comprises a graft ligament engagement member disposed in an opening in a bone, the graft ligament engagement member being arranged to receive a graft ligament alongside the engagement member, and a locking member for disposition in the opening, and at least in part engageable with the graft ligament engagement member. Movement of the locking member in the opening causes the locking member to urge the engagement member, and the graft ligament therewith, toward a wall of the opening, to secure the graft ligament to the wall of the opening. A method for attaching a graft ligament to a bone comprises providing an opening in the bone, inserting the graft ligament and a graft ligament engagement member in the opening, with the graft ligament disposed alongside a first portion of the engagement member, and inserting a locking member in the bone alongside a second portion of the engagement member, the locking member being separated from the graft ligament by the graft ligament engagement member. The method further comprises moving the locking member to cause the locking member to engage the graft ligament engagement member to urge the graft ligament engagement member, and the graft ligament therewith, toward a wall of the opening to secure the graft ligament to the wall of the opening. | 0 |
RELATED APPLICATION
[0001] This is the regular application claiming the filing date under 35 U.S.C. § 119 (e), of U.S. Provisional App. No. 60/735,795 filed Nov. 11, 2005.
BACKGROUND OF THE INVENTION
[0002] The present invention pertains to performance footwear, especially walking and athletic shoes, and most particularly, bowling shoes.
[0003] As has been recognized for a number of years, and as discussed in U.S. Pat. No. 6,907,682, experienced bowlers often desire that each of the left and right shoes exhibit different characteristics, especially with respect to sliding friction on the smooth, wooden or synthetic floors typically present in the approach region of a bowling lane. Moreover, even for one or the other of the left or right shoe, such bowler typically desires a different sliding characteristic on the foresole portion versus the heel portion of that shoe sole. In yet a further customization, the bowler may desire that the friction characteristics of each foresole and heel be adjustable depending on, for example, the surface characteristics of the bowling center in which a particular competition is staged, the day-to-day changes in temperature and humidity in the bowling center, or an increase in confidence as the bowler warms up and reaches peak performance during the course of a match.
[0004] One technique for permitting a bowler to adjust the friction characteristics of one or both shoes, even during competition, is disclosed in U.S. Pat. No. 5,542,198. The concept described therein provides for replaceable foresole and heel surface elements of different configurations and performance characteristics. Although this technique has enjoyed some commercial success, it has the disadvantages of requiring a bowler to carry a kit of varying replacement pads and, even with such a variety of pads, each adjustment increment is a step change, without continuous adjustability.
SUMMARY OF THE INVENTION
[0005] According to one aspect of the present invention, the effective friction of the shoe is adjusted by changing the angle of a portion of the sole, relative to the shoe centerline. According to another aspect, the wearer's weight distribution on the sole can be similarly adjusted.
[0006] In one embodiment, the heel portion of the sole is effectively hinged and an actuating device is spaced from the hinge axis, whereby the wearer can adjust an actuator connected to a drive member that increases or decreases the angle of the hinge. The hinge axis can be perpendicular to the centerline, either in the front of the heel with the drive member embedded in the back of the heel, or in the back of the heel, with the drive member is embedded in the front of the heel.
[0007] This angulation has two significant consequences that affect sliding friction. First, the angulation affects the location on the heel, of the first contact of the heel on the floor following the initial sliding of the foot on the foresole. Secondly the hinging affects the total area of the heel that contacts the floor as the bowler shifts more weight into the heel in order to stop, or brake, the slide. Both of these effects can be adjusted without the replacement of any portion of the heel, and without manipulating any exposed region of the heel relative to another exposed region.
[0008] Adjustment of the sliding friction characteristics of the foresole is also of significance in bowling shoes. The invention is not limited to adjustment of the heel by a hinging action about an axis perpendicular to the shoe centerline. The foresole can likewise be angulated to adjust the sliding friction characteristics.
[0009] More generally, angulation can be effected in the foresole or in the heel, about an axis perpendicular to the shoe centerline, or about an axis that is on or parallel to but offset from the centerline. In this manner, one side of the heel, or one side of the foresole, can be raised or lowered relative to the other side. This kind of lateral adjustment can affect the time dependent friction force resulting from a particular bowler's unique weight transfer in the foot bed during the course of completing the delivery of the bowling ball. As with the heel angulated about an axis perpendicular to the centerline, the lateral adjustment can affect the location of the foresole or heel that first contacts the floor, the total area of the foresole or heel in contact with the floor during the delivery, and the weight distribution over the heel or foresole.
[0010] The adjustment device is partially embedded in one or both of the heel or foresole portions of the sole and is preferably accessible as the sole faces the user's hand or tool in the user's hand. Alternatively, especially in embodiments wherein the hinge is in the heel, the adjustment device can be accessed at an upstanding exterior surface of the heel, such as at the back rim. Actuation of the device can be by any means under the control of the end-user of the shoe.
[0011] The ability to adjust the angle of the heel or foresole, front to back and side to side, can also provide benefits in other performance characteristics that do not depend significantly on the user's sensitivity to sliding friction, but do depend for comfort or safety, on adjustability of the weight-bearing regions. Unlike the present invention, known comfort adjustment techniques do not rely on a hinging of the weight bearing surface of the heel or foresole in a manner that angulates the exposed weight bearing surface relative to the centerline of the shoe.
[0012] In a more detailed characterization of the invention, a shoe having an adjustable weight bearing bottom surface comprises an upper supported by a sole extending generally along a longitudinal centerline, the sole having an arch, a foresole defining a first weight bearing bottom surface longitudinally forward of the arch, and a heel defining a second weight bearing bottom surface longitudinally behind the arch. Each of the first and second weight bearing surfaces has front and back regions and lateral side regions. An adjustment device angulates one of the first or second weight bearing surfaces. Preferably, the adjustment device has a drive member at least partially embedded in the sole and an actuator connected to the drive member such that adjustment of the actuator angulates one of the first or second weight bearing surfaces in relation to the centerline. It should be understood that as used herein, “region” denotes the general location of a sub-area of the outside of a heel or sole, such that, e.g., a side region of the heel can extent into the front or back of the heel.
[0013] The invention can be further characterized in a preferred embodiment wherein the sole includes an exterior outsole having the bottom weight bearing surfaces and a midsole between the upper and the outsole. The drive member spans the midsole and outsole. The actuator selectively expands or contracts the drive member to push or pull the outsole away from or toward the midsole at the location where the drive member is embedded.
[0014] The adjustment device can take a variety of forms. In one embodiment, one disc is embedded in a base portion of the sole, such as in the midsole, and another disc is embedded in a movable portion of the sole, with a threaded bore for receiving a worm screw or the like that has its drive end accessible at the exterior of the sole. With a screw driving device such as an Allen wrench or the like, the user can readily displace the disc in the movable portion of the sole relative to the stationary disc in the base of the sole, thereby increasing or decreasing the angulation about the hinge axis. This can be implemented for continuous adjustment, or can be ratcheted for repeatable stepwise adjustment.
[0015] In another form, the adjustment device can be a disc interposed between the base portion of the sole and the movable portion of the sole, mounted for rotation with an arc of the disc accessible externally for rotation by the user. The disc has variable thickness, preferably monotonically increasing from the minimum to the maximum, whereby rotation of the disc acts a wedge which, depending on the thickness of the disc at the contact with the opposed sole surfaces, defines the hinge angle.
[0016] Other adjustment techniques include an adjustable plug, jack or the like that can be pushed or extended through the footbed or mid sole, to angulate the heel or foresole. An air injection pump or other diaphragm or bladder-type member can likewise be used for this purpose. A step jack with bar analogous to one type of common car jack, or a pulled lever type device, could also be adapted for this purpose.
[0017] In some embodiments, increasing the angle will produce a gap or separation between the base portion and the angulated, weight-bearing portion of the sole. Preferably, measures should be taken to compensate for this discontinuity and resulting decrease in direct weight bearing surface between the base portion and the movable portion of the sole members. This compensation can take the form of providing robust, wide components for the drive member, such as the discs mentioned above, and assuring that the discs are firmly mounted in the respective seats or other stabilizing foundation within the separable components.
[0018] Another advantage uniquely achievable with the present invention is the ability to effectuate a reverse inclination on either the heel or foresole. Bowling, athletic, and other performance shoes, as well as street shoes, are universally manufactured with the main weight bearing, ground contacting surface of the heel in substantially the same plane as the weight bearing, ground contacting surface of the foresole. In other words, the center of the foresole and center of the heel lie flat on a flat surface. As an example with an adjustable heel according to the invention, the neutral adjustment position can correspond to the conventional coplanar relationship between the heel and the foresole, but with positive and negative adjustment options, whereby a back region of the heel weight bearing surface can be raised above ground level, or the front weight bearing region of the heel could be raised above ground level. Similarly, the back region of the heel could be lowered relative to the foresole, or the front region of the heel could be lowered the relative to the foresole. This added capability may be attractive to some bowlers who have unusual foot shapes, approaches, or braking tendencies. When combined with the further option of the exposed surface of the adjustable heel comprising two or more different materials, even greater customization of performance may be achieved.
[0019] It should thus be understood that important an aspect of the invention is that the exposed surface of the sole, i.e., one or both of the heel or foresole, is angulated. There is no adjustment of the footbed or other shoe component that conforms to the wearer's foot. The purpose of the angle adjustment is to increase or decrease the surface area of the sole that contacts the ground or floor. The footbed remains in the same relation to the shoe centerline, but the exposed surface of the adjusted sole portion changes its angular relation to the shoe centerline. This adjustment can affect the timing of when certain portions of the sole contact the ground, which of multiple materials contact the ground and in what sequence, and how the weight of the wearer is distributed on various portions of the foresole and heel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Various embodiments of the invention will be described with reference to the accompanying drawing, in which:
[0021] FIG. 1 is a schematic longitudinal section view of a shoe incorporating one embodiment of the invention;
[0022] FIG. 2A is a schematic detail view of the heel where a representative adjustment device is in a neutral position, FIG. 2B is similar to FIG. 2A , but with the adjustment device in a different configuration, producing an angulation in the heel about a hinge axis at the front of the heel, and FIG. 2C is a view similar to FIG. 2B , but for an alternative embodiment in which the hinge axis is at the back of the heel;
[0023] FIG. 3 is a schematic representation of another embodiment of an adjustment device for angulating the heel;
[0024] FIG. 4 is a schematic representation of yet another adjustment device for angulating the heel;
[0025] FIG. 5 is a schematic representation of an actuation device for angulating the heel about a different axis;
[0026] FIG. 6 is an elevation view of the medial heel portion of a left bowling shoe incorporating an embodiment of the invention analogous to that shown of FIG. 1 ;
[0027] FIG. 7 is a bottom plan view of the heel shown in FIG. 6 ;
[0028] FIG. 8 is a section view along line 8 - 8 of FIG. 7 ;
[0029] FIG. 9 is a section view along line 9 - 9 of FIG. 7 ;
[0030] FIGS. 10A , B, and C schematically illustrate one of many possible techniques for including a ratchet feature with the adjustment device;
[0031] FIG. 11 is a schematic of another embodiment wherein two adjustment devices are situated in the back portion of the heel, on either side of the shoe centerline;
[0032] FIG. 12 is a schematic of another embodiment, wherein two adjustment device are situated in the heel, on the same lateral side of the shoe centerline; and
[0033] FIG. 13 is a section view of one embodiment for implementing the invention in the foresole of a shoe, with the adjustment device situated laterally of the shoe centerline.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] FIGS. 1 and 2 show a schematic representation of one embodiment of the invention as implemented in a left bowling shoe. The representative bowling shoe 10 , has an upper 12 supported by a sole 14 having a foresole with associated flat slide surface 16 and heel 20 defining a nominally flat brake surface 18 . The sole can have one or more layers. An angulation adjustment device 22 is situated in the heel 20 for changing the angle between the surface 18 and the surface 16 , thereby changing the area of the heel surface 18 in contact with the, e.g., bowling lane approach, when the foresole is sliding flat on the approach and the bowler transfers weight into the heel to control braking. For purposes of the present description the term “sole” refers to the entire bottom structure of the shoe, which for exemplary purposes, can conveniently comprise a foresole associated with surface 16 , a heel associated with surface 18 , and an arch (often but not necessarily recessed) situated therebetween.
[0035] FIG. 2 shows a representative construction of the heel portion of a shoe incorporating embodiments of the present invention. The sole construction can include insole 26 and outsole 28 as shown in FIG. 2A . Similarly, the heel 20 includes a base portion 30 attached to midsole 26 or extension of outsole component 28 , and an active portion 32 . The adjustment mechanism or device 22 is partially embedded in the heel, leaving an exposed actuation surface or component 24 , and spans the base portion 30 and active portion 32 . In this context, “spans” means the device remains in contact with the spanned components. In shoes having a recessed arch, the base portion 30 and active portion 32 of the heel are analogous to the midsole 26 and outsole 28 of the foresole, in that these are the two layers closest to the ground when the shoe is worn.
[0036] The effect of manipulating the adjustment mechanism 22 from a nominal condition in FIG. 2A , whereby active heel portion 32 fully abuts the base portion 30 , is shown in an exaggerated condition in FIG. 2B , where the active portion 32 pivots about a hinge axis 33 at the front edge or rim of the heel, and has in part separated from the base portion 30 at the back edge or rim. The mechanism 22 has a first disc 34 embedded in the base 30 , and a second disc 36 embedded in the active portion 32 , with a worm screw 38 fixed at one end 40 to disc 34 and engaging a threaded bore in disc 36 . The other end 24 has a slot or socket for rotating the screw.
[0037] Upon rotation of the screw, the disc 36 is displaced relative to disc 34 , thereby separating active portion 32 from base portion 30 , creating a gap 44 . This also creates an angle 46 relative to the horizontal (such as a flat floor) 42 .
[0038] The material at or along hinge or pivot 33 can be glued or sewn relatively tightly, and the interface between the periphery of the base 30 and active portion 32 can be sewn loosely (not shown), especially adjacent the location of gap 44 , to assure that the hinging occurs at the desired hinge axis and that the base and active portions are separable but to a limited extent at gap 44 . Also, a region (preferably about 50%) of different material than the remainder of the active portion 32 of the heel can be provided to produce a coefficient of friction at exposed surface 18 ′ on one side of the actuation device 22 that is different from the coefficient of friction on the remainder of the surface 18 ″.
[0039] FIG. 2C shows an alternative in which the hinge axis 33 ′ is at the back edge of the heel and the gap 44 ′ opens at the front edge of the heel, whereby the angle 46 ′ is created between heel surface 18 and the ground 42 .
[0040] FIG. 3 is a schematic of another embodiment in which wedge disc 48 is shown between heel portions 30 and 32 . The disc 48 is situated in the space between (i.e., spans) the base 30 and active portion 32 with the center of the disc having an opening through which shaft 56 passes. The shaft has one end fixed to support member 52 , which is in turn fixed within base 30 , and another end fixed to support 54 , which is fixed within active member 32 . The disc has a varying thickness such that, upon rotation by the user, the selected thickness of the disc will bridge the base and active portion 30 , 32 thereby define the gap and thus the angle that is established between members 30 and 32 . An arc segment of the disc projects from the exterior surface of the heel, preferably at the back, thereby serving as a thumb wheel, which directly angulates the heel. The disc 48 functions as both the actuator and the drive member of the adjustment device.
[0041] FIG. 4 depicts another embodiment wherein the adjustment mechanism 58 comprises a thumb wheel 60 that is exposed at the rear of the base portion 30 , for the user to rotate screw 64 which in turn advances or retracts a disc or the like 62 embedded in portion 32 , along with portion 32 .
[0042] The same concept can be utilized to change the angle of the active portion 32 relative to horizontal 42 , laterally as suggested by arrow 74 in FIG. 5 . FIG. 5 is a view from the back of the shoe, in the direction of arrow V as shown in FIG. 1 . In this embodiment, the adjustment device is situated adjacent either the medial or lateral exterior surface of the heel, thereby permitting the adjustment of the pronation angle of the heel. Any of the adjustment devices previously described may be utilized for this embodiment. A device 66 analogous that shown in FIG. 2 is shown in FIG. 5 . A first disc 68 is embedded in the base portion 30 and a second disc 70 is embedded in active portion 32 , with an adjustment screw 72 extending between the discs and exposed to a bottom surface of the heel for access by the user. The active and base portions 32 , 30 can be separated or brought closer together, with an effective pivot or hinging axis at 76 , running parallel to but offset below the shoe centerline. This raises or lowers one side of the exposed surface of the heel, relative to ground the 42 , as shown at 74 .
[0043] It should thus be understood that the front-to-back angulation represented by α in FIG. 1 and the side-to-side angulation represented by arrow 74 in FIG. 5 can each be considered as changing the relationship of a weight bearing surface to the longitudinal centerline of the shoe or sole
[0044] FIGS. 6 through 9 show additional details for implementing a variation of the embodiment shown generally in FIGS. 1 and 2 . In this embodiment, the adjustment device is situated in the forward region of the heel, with the hinge axis situated toward the back of the heel, in contrast to the embodiment shown in FIG. 1 , where the adjustment device is centered or toward the back of the heel, and the hinge axis is relatively forward in the heel.
[0045] FIG. 6 is an elevation view of a bowling shoe 100 , rearward of the arch. In this view the adjustable, active portion of the heel is shown at 112 , adapted for contacting the ground. The base portion 114 of the heel rests on the active portion 112 , and a riser portion 116 of the shoe upper is connected to the base portion 114 . In this context, base portion 114 can be considered a midsole component in relation to the active portion 112 , which can be considered the outsole component.
[0046] FIG. 7 shows the same portion 100 of the shoe depicted in FIG. 6 . The adjustment device 118 is situated in the front or forward portion of the heel, substantially vertically beneath the shoe centerline CL. Only the adjustment screw 120 is visible and accessible from the bottom of the heel. The adjustment screw 120 can carry a structural or applied marker for selective alignment with visible discreet indicia 122 carried on the surrounding surface of the heel. In this manner, the user can reproduce a particular angular adjustment by realigning the marker with a particular one of the indicia. Preferably, the adjustment device includes a ratchet or similar discrete action, corresponding to the discreet indicia.
[0047] In this embodiment, the adjustable portion 112 and the base portion 114 of the heel converge 124 at the rearward portion of the arch, where a gap is formed which increases or decrease in size according to the position of the adjustment device. At the back of the heel, a fulcrum or pivot line is effectively formed by the overlap of the base 114 relative to the active portion 112 , as shown at 126 , 128 . The overlap 126 serves as a curtain, camouflaging the pivoting and therefore avoiding any detrimental aesthetic appearance in the shoe. Alternatively, an accordion type covering can be provided.
[0048] FIG. 8 is a section view through line 8 - 8 of FIG. 7 and FIG. 9 is a section view through line 9 - 9 of FIG. 7 . The base 114 serves as the mid sole and the adjustable portion 112 serves as the outsole. In this particular embodiment, the risers 116 forming part of the upper are connected to the base 114 , such that the inner surface of the riser and the upper surface of the base portion merge to form foot bed 130 ′, 130 ″. The side portion of the base 114 can also provide an overlap or curtain 132 relative to the sidewall 134 of the active member 112 . The exposed bottom surface of the active member 112 can have recesses or other patterns 136 (not shown in FIG. 7 ) in a well-known manner, for both aesthetic and functional purposes, but the overall boundary of the bottom surface is substantially flat. Within the active portion 112 , one or more cavities 138 can be formed for weight savings and comfort.
[0049] In the illustrated embodiment, a substantially circular rim 140 provides a support wall and is upstanding to the extent of close or contact relation with the underside of the base portion 114 . A cavity 142 is established within the support wall 140 , for containing the main components of the actuating device. In this embodiment, the active disc 144 rests on transverse support surface 146 at the bottom of the support wall 140 . This can be cemented in place, or rotationally restrained by lugs or the like (not shown) engaging the support wall 140 . Another disc 148 is seated for rotation at 150 at the underside of the base member 114 . An Allen screw or the like 120 spans these discs and is fixed with respect to disc 148 , but cooperates with the active disc 144 as in a worm gear. In this manner, rotation of the screw forces the active disc 144 to move away from or toward the stationary disc 148 . As the active disc 144 separates and moves away from the fixed disc 148 , it acts on the support surface 146 to cause separation of the active portion 112 of the heel from the base portion 114 of the heel along interface 152 . As a result, much of the weight of the bowler after release of the ball and into the follow-through shifts to the heel and is ultimately transmitted from the fixed disc 148 , through screw 120 , to the active disc 144 . Accordingly, the screw threads and the mating threads in the active disc 144 will be sufficiently robust to accommodate this weight. Furthermore, inasmuch as the heel 112 has separated from the base 114 the weight will not be transmitted to the active portion 112 at the sidewalls through the interface 152 . The active disc 144 should be of sufficient width or diameter, or include other stabilizer structure (not shown) to enable the user to maintain proper balance during desired or inadvertent lateral weight shift within the foot bed 130 .
[0050] As described above, during adjustment, the active portion 112 will separate to some extent form the base portion 114 , as a result of the displacement of the active disc 144 relative to the fixed disc 148 . While the wearer applies weight on the foot bed 130 , these members 112 , 114 are urged toward each other. However, during a bowler's stride or at other times when the shoe is above the ground without support from below, the active portion 112 would have a tendency to separate from the base portion 114 . This is prevented by the gluing and/or stitching described above with reference to FIG. 2 . Alternatively, or in addition, other embodiments of the adjustment device itself can include structure that is fixed with respect to the base 114 , such as described below with respect to FIG. 10 .
[0051] FIGS. 10A , B and C show one embodiment for including a ratchet mechanism or similar step-wise, incremental setting of the degree of adjustment. This is especially helpful in conjunction with the indicia previously described, for precisely returning the adjustment to a known setting that is to be reproduced. The active portion of the heel 112 ′ includes stationary but rotatable disc 140 with rigidly projecting adjustment screw 142 . A ratchet type mechanism 144 is also located in base portion 114 ′, spring loaded toward to circumference of the disc 140 , which has a saw toothed or similar rim 140 ′. The members 146 , 148 are threaded to screw 142 and, as the screw is rotated, the members are displaced along the screw, thereby moving active heel portion 112 ′ either toward or away from base portion 114 ′. The ratchet-type or similar detent mechanism retains the screw in a selected rotational position upon completion of the adjustment. Such movement is preferably accompanied by a sequential clicking sound generated between the ratchet 144 and rim 140 ′.
[0052] In a preferred implementation in which a single adjustment device is on the shoe centerline at the back of the heel, the movable disc has a diameter of at least about 50 mm for providing sufficient stability. The ratchet has at least seven stop positions, with eight being ideal, e.g., +4 to 0 (neutral whereby the heel and foresole are substantially coplanar) to −4. Each turn of the screw through 180 degrees, advances the moveable disc and active portion of the heel, about 0.5 mm.
[0053] FIG. 11 shows another embodiment 200 , in which two actuation devices 202 , 204 are situated in the rearward region of the heel, thereby hinging the heel about an axis 206 in the forward portion of the heel, transverse to the centerline.
[0054] FIG. 12 discloses another embodiment 300 wherein two actuation devices 302 , 304 are both situated on one lateral region of the centerline of the heel in a manner that effectuates a lateral adjustment about a hinge axis at 306 that is parallel to but offset from the shoe centerline.
[0055] FIG. 13 shows another embodiment 400 , implemented in the foresole along one lateral side of the shoe centerline 402 whereby a lateral adjustment can be made by actuating the adjustment device 404 to angulate the outsole 406 relative to the midsole 408 about a hinge axis 410 that is parallel to but laterally offset from the shoe centerline.
[0056] FIG. 13 also shows schematically within the phantom lines 412 , that other types of adjustment devices can be located for access through the footbed 414 , to angulate not only the foresole, but alternatively the heel, either front to back or laterally.
[0057] From the foregoing detailed examples, one of ordinary skill in this field can also implement a hinge adjustment in the foresole about an axis transverse to the centerline, thereby lifting or lowering the forward or back portion of the foresole, in a manner analogous to that described with respect to the heel.
[0058] It should be appreciated that the foregoing embodiments can be implemented with only one adjustment device, but two devices enhance stability and offer greater precision, especially for the lateral adjustment. Two or more can be used in combination, for fore/aft and lateral angulation. The invention can be used in other types of performance shoes, including but not limited to shoes used in court games, such as basketball or tennis, and walking shoes, driving shoes, etc. | The effective friction of a shoe is adjusted by changing the angle of a portion of the sole, relative to the shoe centerline. In one embodiment, the heel is effectively hinged and an adjustment device is spaced from the hinge axis, whereby the wearer can hold the shoe in one hand and manually adjust an actuator connected to a drive member that increases or decreases the angle of the hinge. The hinge axis can be perpendicular to the centerline, either in the front of the heel with the drive member embedded in the back of the heel, or in the back of the heel, with the drive member embedded in the front of the heel. Angulation can be effected in the foresole, about an axis perpendicular to the shoe centerline, or about an axis that is parallel to but offset from the centerline. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to road grading equipment and in particular to a drag-type road grader.
2. Description of the Prior Art
Nonpaved roads comprising dirt, gravel and the like generally require periodic maintenance to repair the damage done thereto by vehicular traffic. A common maintenance procedure is to regrade and relevel the roads with equipment especially designed for this purpose. For example, self-propelled road graders are well known and may be provided with blades for scraping, leveling and reshaping a road surface. The blades are generally adjustably mounted with respect to height, pitch and angle relative to the direction of travel. For road grading purposes, the blades are usually oriented at an oblique angle with respect to the direction of travel so that excess road material flows transversely.
However, such self-propelled, conventional road graders have several drawbacks for the maintenance of roads comprising dirt, gravel and the like. First of all, generally only a single blade is mounted thereon. The single blade performs both cutting and filling operations wherein material is respectively removed from the high spots and deposited in the low spots. The only packing and compression of such redistributed material which occurs is by the rear wheels of the vehicle. Therefore, only the fractional portion of the blade's swath directly in the path of the vehicle rear wheels is compacted.
Secondly, self-propelled road graders operate best on relatively dry roads because their blades tend to stick in damp road materials. However, dry, loose material is susceptible to being blown out of level before being compacted by vehicular traffic. For example, pot holes filled under dry conditions with a single-blade road grader may be emptied and reopened by a high wind.
Yet another disadvantage of conventional, self-propelled road graders is their slow operating speeds. Excessive blade vibration or "chatter" typically occurs at speeds of approximately four miles per hour. The relatively slow operating speeds of such equipment tend to increase the cost of road maintenance therewith through such factors as labor, equipment usage, fuel consumption, maintenance and the amount of equipment required to maintain a given road network.
Drag-type road graders are also well known and are pulled along roads by tractors and the like. In fact, such drag-type road graders may be successfully employed in combination with self-propelled, single-blade road graders since the addition of the former can help compensate for the deficiencies of the latter. An exemplary drag-type road grader is shown in the Hall U.S. Pat. No. 1,185,090 and comprises a rectangular frame with a pair of blades extending thereacross at oblique angles. The Thurston U.S. Pat. No. 1,303,415 shows a frame with transverse blades. The frame members of the Thurston device are pivotally connected whereby the frame may be skewed to form a parallelogram to adjust the angles of the blades with respect to the direction of travel.
SUMMARY OF THE INVENTION
In the practice of the present invention, a road grader is provided which includes a frame having a pair of parallel, longitudinal trusses interconnected by rectangular subframes. Each subframe is pivotally connected to the trusses and includes a blade assembly. A tongue assembly extends along the direction of travel and the longitudinal axis of the grader and includes power cylinders for skewing the frame to parallelogram-shaped configurations by longitudinally shifting the trusses relative to each other and by rotating the subframes with respect to the trusses. The subframes are pivotally connected to the frame trusses by a plurality of hinge mechanisms with vertical, pivotal axes. A pair of wheel assemblies are retractably mounted on the frame for transporting the grader in a non-working mode.
OBJECTS OF THE INVENTION
The objects of the present invention are: to provide a drag-type road grader; to provide such a grader for roads comprising dirt, gravel and the like; to provide such a grader which is well adapted for working relatively damp roads; to provide such a grader with a plurality of transverse blades; to provide such a grader with a frame which may be skewed to angle the blades a desired amount relative to the direction of travel; to provide such a grader wherein the heights of the blades are independently adjustable; to provide such a grader which includes a blade for compacting redistributed material; to provide such a grader which includes an hydraulic system for skewing its frame; to provide such a grader which includes retractable wheels for towing in a non-working mode; to provide such a grader wherein the blades are independently and vertically adjustable; to provide such a grader which is efficient in operation, economical to manufacture, capable of a long operating life and generally well adapted for the proposed useage thereof.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.
The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan of a road grader according to the present invention.
FIG. 2 is a top plan of the road grader in a first skewed configuration.
FIG. 3 is a top plan of the road grader in a second skewed configuration.
FIG. 4 is a side elevation of the road grader.
FIG. 5 is a vertical cross section of the road grader taken generally along line 5--5 in FIG. 1.
FIG. 6 is a vertical cross section of the road grader taken generally along line 6--6 in FIG. 4.
FIG. 7 is a vertical cross section of the road grader taken generally along line 7--7 in FIG. 1.
FIG. 8 is a fragmentary perspective of the road grader particularly showing a hinge assembly.
FIG. 9 is a fragmentary side elevation of the road grader particularly showing a transport wheel assembly.
FIG. 10 is a vertical cross section of the road grader taken generally along line 10--10 in FIG. 4.
FIG. 11 is a fragmentary, vertical cross section of the road grader particularly showing a compacting blade.
FIG. 12 is a fragmentary horizontal sectional view taken on line 12--12 of FIG. 5 and illustrates details of a hinge assembly.
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.
Referring to the drawings in more detail, the reference numeral 1 generally designates a road grader embodying the present invention. The road grader 1 generally comprises a distortable frame 2, a pair of retractable transport wheel assemblies 3 and a tongue assembly 4. First, second, third and fourth blade assemblies 11, 12, 13 and 14 respectively extend transversely across the frame 2. The frame 2 includes a pair of longitudinal trusses 16 each having upper, lower and outer rails 17, 18 and 19 rigidly interconnected by cords 20. The outer rails 19 are spaced equidistantly from the upper and lower rails 17 and 18 and form triangular configurations therewith when viewed from the end.
A plurality of hinge and blade depth adjustment mechanisms 25 are mounted on each truss above respective ends of the blade assemblies 11, 12, 13 and 14. Each hinge mechanism 25 includes inner and outer angle members 26, 27. The outer angle members 27 are welded to respective upper and lower rails 17, 18 and chords 20 at the intersections thereof and include four receivers for blade assembly mounting bolts 28.
The inner angle member 26 of each hinge mechanism 25 is welded to a respective upright hinge bushing 29 with upper and lower ends 30, 31 protruding above and below respective upper and lower rails 17, 18. The inner angle member 26 includes a plurality of elongated slots 32 for receiving the bolts 28 whereby the angle members 26, 27 are vertically adjustably connected. A hinge pin 37 comprising, for example, a length of hollow pipe having an outside diameter slightly less than the inside diameter of the hinge bushing 29 is inserted in the latter and rotatable with respect thereto about a vertical axis. Upper and lower collars 38, 39 are mounted on the hinge pin 37 at the upper and lower ends 30, 31 respectively. The upper collars 38 of the four transversely aligned pairs of hinge mechanisms 25 are interconnected by four tie rods 40.
Each blade assembly 11, 12, 13 and 14 includes a respective transverse torque tube 46 having a rectangular cross-sectional configuration. Each torque tube 46 is welded to a respective pair of lower collars 39. Blade mounting bars 47 are welded to the torque tubes 46 and include longitudinally spaced receivers for blade mounting bolts 49.
First, second, third and fourth blades 51, 52, 53 and 54 are bolted on the blade mounting bars 47 of respective blade assemblies 11-14. Each blade 51-54 includes a proximate leg 55 with longitudinally spaced receivers for the bolts 49 and a distal leg 56 forming an obtuse angle with respect to the proximate leg 55. Although the blade mounting bars 47 and the blades 51-54 are substantially identical, they are mounted on the blade assembles 11-14 in different orientations for performing different functions. The first and second blades 51, 52 are oriented as shown in FIG. 1 for scraping with their distal legs 56 extending downwardly and rearwardly. The blade mounting bars 47 of the blade assemblies 11, 12 are welded on rear faces of respective torque tubes 46.
The blade mounting bar 47 of the third blade assembly 13 is welded on the front of the torque tube 46. The third blade 53 functions as a cutter and is bolted to the blade mounting bar 47 with its distal leg 56 extending forwardly in the direction of travel. The blade mounting bar 47 of the fourth blade assembly 14 is welded to a respective torque tube 46 along the bottom edge of its front face and slopes upwardly and forwardly therefrom forming an upwardly open acute angle with the front face of the torque tube 46. Spacers 57 are welded to the upper edge of the torque tube front face and to the blade mounting bar 47 of the fourth blade assembly 14. The fourth blade 54 is bolted to the blade mounting bar 47 with its proximate leg 55 sloping downwardly from front to back and its distal leg 56 substantially horizontal and positioned beneath the torque tube 46. The fourth blade 54 functions to compact and smooth the material scraped and cut by the preceeding blades 51, 52 and 53.
Associated tie rods 40 and torque tubes 46 are rigidly connected at their ends to respective hinge pins 37 by the collars 38, 39 whereby they are maintained in parallel, vertically spaced relationship. Associated tie rods 40; torque tubes 46; collars 38, 39; and hinge pin pairs 37 thus interconnected form rectangular first, second, third and fourth subframes 61, 62, 63 and 64. The third subframe 63 includes diagonal braces 65 connected to the tie rod 40 and the torque tube 46 at locations spaced slightly inwardly from the hinge pins 37. The diagonal braces 65 function to maintain the subframes 61-64, and particularly the third subframe 63, in rectangular configurations and to resist racking and twisting forces acting on the frame 2 about its longitudinal axis.
The tongue assembly 4 includes a tongue 73 extending generally along the longitudinal axis of the grader 1 with front and back ends 74, 75. The tongue 73 comprises a rectangular tube 76 with a draw bar 77 on the tongue front end 74 for receiving a trailer hitch (not shown) and a clevis 78 mounted on the tube 76 at the tongue back end 75.
The tongue 73 is pivotally attached to a cross-bar 81 extending between the trusses 16 in front of the second subframe 62 by a tongue mounting bolt 82. The cross-bar 81 includes clevis ends 83 pivotally bolted to cross-bar mounting ears 84 extending forwardly from the hinge mechanisms 25 at the second subframe 62. The cross-bar 81, in conjunction with the rectangular subframes 61-64 helps to maintain the trusses 16 in parallel, spaced relation.
A pivot bar 87 is attached to a hinge mechanisms 25 at the first subframe 61 and to the rectangular tube 76 by ball and socket connections 88 at its opposite ends. The pivot bar 87 centers the tongue 73 within the first subframe 61 and aligns it with the grader longitudinal axis and direction of travel. The ball and socket connections 88 allow for limited movement of the pivot bar 87 from the horizontal so that the tongue 73 can float to a limited extent in a vertical plane. Such vertical tongue movement might result, for example, from relative dislocation between the grader 1 and a tow vehicle caused by changing road surface elevations. A tongue stop 89 extends upwardly from the torque tube 46 of the first blade assembly 11 and provides a lower limit to the vertical travel of the tongue 73.
A pair of extensible and retractible motors comprising double-acting hydraulic power cylinders 91 are provided for skewing the frame 2. Each hydraulic cylinder 91 is pivotally connected to a cylinder mounting ear 92 on a respective side of the rectangular tube 76 and to a cylinder mounting bar 93 extending forwardly from the cross-bar 81. Hydraulic lines 94 communicate the cylinders 91 with a source of pressurized hydraulic fluid (not shown) which may be located, for example, on the tow vehicle.
Each transport wheel assembly 3 includes a pair of wheels 101 with tires 102 and a wheel carriage 103 for extending and retracting the wheel carriage 103 between lowered and raised positions. The wheel carriage 103 includes a pair of triangular wheel carriage subframes 104 comprising base, vertical and hypotenuse members 105, 106 and 107. A wheel carriage pivot tube 111 interconnects the subframes 104 at the intersections of their base and vertical members and is rotatably received within a wheel carriage bushing 112 welded to a respective lower rail 18 and a cord 20. The wheel carriage bushing 112 connection with the truss 16 is reinforced with triangular gussets 113. The wheel carriage subframes 104 are interconnected at the intersections of their vertical and hypotenuse members 106, 107 by a cylinder mounting beam 114. At the intersections of their base and hypotenuse members 105, 107, axles 115 are attached to the subframes 104 for mounting the wheels 101.
A pair of extensible and retractible motors comprising double-acting hydraulic power cylinders 121 are provided for extending and retracting the wheel assemblies 3. Each cylinder 121 is pivotally connected at one end to a cylinder mounting ear 122 welded to a respective lower rail 18 and a cord 20. A cylinder rod clevis end 126 is pivotally connected to a tab 124 positioned in the cylinder mounting beam 114. Hydraulic lines 125 communicate the hydraulic cylinders 121 with the source of pressurized hydraulic fluid.
In operation, the road grader 1 may be transported to a work location by extending (lowering) the transport wheel assemblies 3. As shown in FIG. 4, the axes of the transport wheels 101 extend transversely of the forward half of the frame 2 so that the road grader 1 is tail-heavy in its transport position. The tongue 73 is attached to a tow vehicle and because the grader 1 is tail-heavy, the tongue 73 rests on the tongue stop 89.
The transport wheel assemblies 3 are retracted by extending the hydraulic cylinders 121 so that the wheels 101 are positioned above the level of the blades 51-54. The grader 1 is then skewed with the hydraulic cylinders 91. The hydraulic system causes one of the hydraulic cylinders 91 to extend as the other retracts and vice versa so that the frame 2 is skewed to either of the configurations shown in FIGS. 2 and 3 whereby excess road material is strewn laterally to the left or right. Thus, the operator can selectively determine which side of the grader 1 is to receive the excess material therefrom.
The function of the blades 51-54 may be altered by reversing their orientations. For example, the second blade 52 is shown in a scraper orientation. However, by reversing it so that its distal leg 56 extends in the direction of travel it will function as a cutter. The elongated slots 32 allow for adjusting the working depths of the blades 51-54. Vertical adjustments are accomplished by loosening the blade depth adjustment mounting bolts 28, shifting the angle members 26, 27 vertically with respect to each other and retightening the bolts 28 with the blade properly repositioned. Such working depth adjustments may be required to compensate, for example, for differential wear in respective blades 51-54.
It is to be understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown. | A drag-type road grader including a skewable frame and a plurality of blade assemblies extending transversely across the frame. A tongue assembly is mounted on the frame and includes hydraulic cylinders for skewing the frame to alternative parallelogram-shaped configurations whereby the blade assemblies are angled with respect to the direction of travel. Retractable wheel assemblies are provided for transporting the grader in a non-working mode. | 4 |
BACKGROUND
The problem of erosive damage to seals and metal components in downhole flow devices has been a challenge in the industry for quite some time. In a wellbore, for example, sliding sleeves are used in applications where high velocity flow can create a very hostile environment. The high velocity flow, especially when it contains solids, can induce flow erosion even in the hardest materials available. Additionally, when a pressure differential is unloaded across a conventional seal, severe damage can occur that renders the seal inoperable.
In the prior art, techniques that address unloading of a pressure differential across seals have used thin equalizing slots and diffuser type seals. The arrangement is intended to prevent damage to two sets of seals, or packing units, that create a barrier between the annulus and tubing pressure. Examples of this prior art technique are disclosed in U.S. Pat. Nos. 5,316,084 and 5,156,220. Prior designs such as these may not prevent damage to seals caused by abrasive flow because the seals may never be adequately protected from an initial surge of pressure during the opening sequence.
Although prior art sealing techniques may be effective, operators are continually striving for improvements to reduce the effects of erosion or pressure differential on seals used downhole. Accordingly, the subject matter of the present disclosure is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.
SUMMARY
A downhole flow device has a sliding sleeve and a ported sleeve. The sliding sleeve moves hydraulically along an axis of the ported sleeve to reveal successive ports defined along the axis of the ported sleeve. Fluid pressure applied to an open control line enters a sealed chamber between the sliding sleeve and the housing and moves the sliding sleeve along the ported sleeve.
To limit movement of the sliding sleeve, a catch has a dog that engages in a slot in the sliding sleeve. As the sliding sleeve moves, the dog moves the catch with the sliding sleeve. At a pinnacle position of the catch, the sliding sleeve can no longer be moved by the hydraulic fluid due to the catch engaging a stop. When moving the catch to its stop, the sliding sleeve reveals one of the ports in the ported sleeve, allowing flow to pass through the device.
To reset the catch so the sliding sleeve can be advanced to reveal the next port, a trigger between the sliding sleeve and housing can also move by the hydraulic pressure applied. This trigger moves on the sliding sleeve until it reaches another stop that limits its movement. When hydraulic pressure is released, the trigger moves by the bias of a spring to a reset position on the sliding sleeve. As it moves, the trigger dislodges the catch's dog from the sleeve's slot. This allows a spring to move the catch to a next lower position where the dog can then engage in a next slot on the sliding sleeve. Once completed, the mechanism is reset so that reapplication of hydraulic pressure can move the sliding sleeve to its next position. Applying hydraulic pressure to another port can move the sliding sleeve all the way back to its closed condition.
A seal is provided between the sliding sleeve and the ported sleeve. The seal has a first seal component disposed on the sliding sleeve and has a second seal component disposed on the ported sleeve. These seal components engage one another to seal flow, and they move apart to allow fluid flow through the ports in the ported sleeve. Operation of the device and the seal reduce both erosion and damage caused by high velocity flow, abrasive flow, and differential pressures. In other words, the device and seal prevent damage to the seal when unloading a differential pressure across it, and the seal is designed in such a way that abrasive flow does not have the opportunity to impinge on the sealing surface to cause erosion.
The foregoing summary is not intended to summarize each potential embodiment or every aspect of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A illustrates a cross-sectional view of a downhole tool according to the present disclosure.
FIG. 1B illustrates a detailed view of a portion of the downhole tool.
FIG. 2 illustrates a seal of the disclosed tool in more detail.
FIG. 3 illustrates a graph of flow passages for the seal of FIG. 2 .
FIGS. 4A-4B show pressure assistance of the seal for the downhole tool when exposed to internal or external pressure differentials.
FIG. 5 shows the downhole tool in a closed condition.
FIG. 6 shows the downhole tool in a first condition towards opening.
FIGS. 7-9 show the downhole tool in several subsequent conditions towards opening.
FIGS. 10-14 show the downhole tool being hydraulically actuated in various stages of opening.
DETAILED DESCRIPTION
A. Downhole Flow Device
In FIGS. 1A-1B , a downhole flow device 100 has a housing 110 , a sliding sleeve 120 , a ported sleeve 170 , a landing 180 , and a seal 200 . As shown, the housing (indicated generally by 110 ) can have a number of interconnecting housing portions 110 a - f that facilitate assembly. In the present implementation, the flow device 100 is a reservoir control tool that couples at uphole and downhole ends 102 / 104 to other tubing components (not shown), although the teachings of the present disclosure may be used on any other downhole flow device, such as a sliding sleeve, a downhole control valve, a crossover tool, etc. When used for reservoir control, the tool 100 operates as a hydraulically-actuated variable choke valve and can adjust the rate of production or injection of fluid through the tool 100 .
For example, the tool 100 can be run as part of a completion tubing string in the well. Once deployed, operators can operate the tool 100 to variably choke back the production from the well's annulus into the tool 100 . This may be done to reduce the rate of water produced from the well or to balance the rate of production (and the rate of pressure drop) of one producing zone against another. In some cases, each production zone could have a corresponding tool 100 that can be varied. As opposed to production, the tool 100 may also be used for varied injection of fluids from the tubing string into the annulus of the well.
The ported sleeve 170 has a plurality of ports 174 a - g disposed on an axis of the sleeve 170 . Exposure of more or less of the ports 174 a - g increases or decreases the flow through the tool 100 . Although shown having several separate ports 174 a - g, the ported sleeve 170 can have one or more ports disposed along the axis of the sleeve 174 so that more or less exposure of the one or more ports can increase or decrease flow through the tool 100 . For example, the ported sleeve 170 can having one port that increases in size along the axis of the ported sleeve 170 and can have any desirable shape.
To choke the flow into or out of the tool 100 completely, the sliding sleeve 120 fits all the way onto the ported sleeve 170 as shown in FIGS. 1A-1 B so that none of the ports 174 a - g in the ported sleeve 170 are exposed. As shown, the seal 200 on the closed sleeves 120 / 170 seals flow into (or out of) the tool 100 when the sliding sleeve 120 is in a closed position on the ported sleeve 170 . To achieve variable choking, the tool's sliding sleeve 120 can be hydraulically moved relative to the ported sleeve 170 , and the changing position of the sliding sleeve 120 controls the flow into (or out of) the sleeve's bore 172 by disengaging the seal 200 and exposing more or less ports 174 in the ported sleeve 170 .
When the sliding sleeve 120 is moved, for example, the seal 200 separates, and the sliding sleeve 120 opens relative to the ports 174 to allow fluid to flow from a surrounding annulus through windows 106 in the tool's housing 110 (i.e., portion 110 e ) and into the ported sleeve's bore 172 (or vice versa). As best shown in FIG. 1B , the ports 174 a - g defined in the ported sleeve 170 generally increase in size (diameter) along the axis of the sleeve 170 . Therefore, the first ports 174 a (four of which are defined around the circumference of the ported sleeve 170 ) have a first diameter, while the other ports 174 b - e above them have a slightly greater diameter. The next highest port 174 f has an even greater diameter, and the last port 174 g has the largest diameter. In this way, as the sliding sleeve 120 moves along the ported sleeve 170 , the sliding sleeve 120 successively reveals more of the ports 174 a - g , which increases the flow through the tool 100 .
In the current arrangement, the tool 100 can operate at eight discrete positions to control the amount of flow area through the tool 100 . These positions are defined in percentages of the flow area of the tubing string (specifically the diameter of the ported sleeve's bore 172 ). For example, the tool's positions can be defined as follows: 0% closed, 1% open, 3% open, 5% open, 7% open, 9% open, 15% open, and 100% open. Therefore, with the tool 100 set at the 5% position, the ports 174 a - c are exposed, and the flow area through the tool 100 is 5% of the flow area through comparably sized tubing. As will be appreciated, these values are illustrative. The actual size and number of ports 174 a - g for an implementation depends on the overall size of the tool 100 and the desired or expected flow characteristics as well as other implementation specific details. In other examples, the tool 100 may have more or less ports, and some or all of the ports may have the same diameters.
B. Seal for Downhole Flow Device
As best shown in FIG. 1B , the seal 200 has first and second seal components 210 / 250 that mate with one another when the sliding sleeve 120 is closed. The first (moving) component 210 moves with the sliding sleeve 210 , while the second (stationary) component 250 remains stationary. Either one or both of these components 210 / 250 can be incorporated into its respective sleeve (as is the stationary component 250 ) or can be an independent component affixed onto its respective sleeve (as is the movable component 210 ). As discussed below, the seal components 210 / 250 are intended to reduce damage to the seal 200 , and the design of the seal 200 is such that it resists erosion and is self-protecting.
Details of the seal 200 are shown in FIG. 2 . The moving component 210 has a first inner shelf 212 , a first inner ledge 214 , a second inner shelf 216 , and a second inner ledge 218 —each of which face inward toward the ported sleeve (not shown). The stationary component 250 has a somewhat complimentary configuration, including a first outer shelf 252 , a first outer ledge 254 , a second outer shelf 256 , and a second outer ledge 258 —each of which face outward from the ported sleeve (not shown). The stationary component 250 may also define a well 255 where the second outer shelf 256 mates with the first outer ledge 254 .
The shelves 212 / 252 define a first flow passage 202 , the first ledges 214 / 254 define a second flow passage 204 , and the second shelves 216 / 256 define a third flow passage 206 through which fluid can flow through the seal 200 . The flow passages 202 , 204 , and 206 create seal points between the metal-to-metal seal produced between the components 210 / 250 . Engagement between the first ledges 214 / 254 produces the primary sealing function when the components 210 / 250 are closed against one another.
With an understanding of the seal 200 and its components 210 / 250 , discussion now turns to how the seal 200 achieves pressure assisted and erosion resistant sealing on the tool 100 .
1. Pressure Assisted Sealing
The seal 200 is assisted closed in metal-to-metal engagement by either internal pressure acting inside the tool 100 or by external pressure acting outside the tool 100 . In FIGS. 4A-4B , the tool 100 is shown closed, and the seal components 210 / 250 are shown mated with one another. A lower packing element or seal 178 seals between the ported sleeve 170 and the housing 110 (i.e., portion 110 f ) and isolates fluid pressure inside the tool 100 from outside the tool 100 .
As noted previously, the primary sealing function of the closed seal 200 is provided by engagement of ledges 214 / 254 . As constructed, the engagement 214 / 254 are set at a circumference that matches a centerline circumference of the lower packing seal 178 on the tool 100 . As described below, the arrangement of the ledges 214 / 254 , centerline, the packing seal 178 , and other features give pressure assistance to the seal 200 regardless of whether the tool 100 is exposed to internal or external pressure differentials.
In FIG. 4A , an internal pressure differential in the bore 112 is shown acting on the tool 100 . Fluid pressure is capable of acting against the distal end of the ported sleeve 120 , which is exposed and unsealed relative to the fluid pressure in the bore 112 . As a consequence, the fluid pressure can act against the lower shoulder of the packing seal 178 . This fluid pressure creates a piston effect on the ported sleeve 170 . The resulting pressure pushes the ported sleeve 170 and its seal component 250 toward the sliding sleeve 120 and its seal component 210 , thereby assisting the sealing engagement between them.
In FIG. 4B , an external pressure differential is shown acting on the tool 100 , but the seal 200 is also pressure assisted in this circumstance. The external fluid pressure acts against the upper shoulder of the packing seal 178 . This moves the packing seal 178 away from the ported sleeve's adjacent shoulder so that the seal 178 abuts a landing 180 unconnected to the ported sleeve 170 . As a consequence, the fluid pressure can act against the ported sleeve's shoulder. Again, this tends to create a piston effect on the ported sleeve 170 that attempts to push the ported sleeve 170 and its seal component 250 toward the sliding sleeve 120 and its seal component 210 . Therefore, the seal 200 and configuration of the ledges 214 / 254 and seal 178 help pressure assist the seal produced regardless of whether exposed to an internal or external pressure differential.
2. Erosion Resistant Sealing
As noted previously, the tool 100 can encounter problems caused by erosive damage to seals and metal components when varying flow therethrough. The seal 200 of the present disclosure is intended to control the velocities of abrasive flow and isolates portion of the seal 200 from the flow as much as possible to mitigate erosive damage.
Returning to FIG. 2 , the first flow passage 202 from the shelves 212 / 252 creates a very small choke when the components 210 / 250 are closed or slightly open. The second shelves 216 / 256 providing the second flow passage 206 also provide a secondary choke that reduces the flow possible through the seal components 210 / 250 .
At the instant the seal components 210 / 250 start to separate and break the seal between the ledges 214 / 254 , the first flow passage 202 allows fluid to flow through the seal 200 , but the small gap between the shelves 212 / 252 defines the smallest available flow area through the seal 200 . This secondary choke from the sealing ledges 214 / 254 also limits the detrimental flow when the seal components 210 / 250 are first separated.
The limited flow area through the first flow passage 202 means that any sudden erosive flow from fluids flowing from the annulus into the tool (or vice versa) mainly interacts with the shelves 212 / 252 . Accordingly, the shelves 212 / 252 take the brunt of the erosive flow rather than the sealing ledges 214 / 254 themselves, which are susceptible to detrimental erosion. In this way, the seal 200 can be self-protecting by making erosion occur away from the sealing ledges 214 / 254 at initial opening of the seal 200 .
As the sliding sleeve 120 is moved on the ported sleeve 170 , the area of the flow through passages 202 , 204 , 206 changes. Details of how the flow area changes are shown in FIG. 3 , which graphs some calculations for a tool 100 having an internal diameter of about 5-in. As evident from FIG. 3 , the first flow passage 202 defines a limiting flow area through the tool 100 as the seal 200 is initially opened (i.e., when the sleeve 120 has traveled from 0 to 1-in.).
In one implementation, the sliding sleeve ( 120 ) travels approximately 0.5-in. open from the ported sleeve ( 170 ) to expose the first port ( 174 a ) and allow 1% of flow through the tool 100 . In this way, the shelves 212 / 252 act to choke the flow and take the brunt of any erosive flow until the valve is 1% open. Even after that point, the first inner ledge 214 is already moved clear of the first port ( 174 a ) so the ledge 214 can avoid erosive flow, as detailed below.
FIGS. 5-9 show some initial conditions of the seal 200 as the tool 100 opens (or closes in the reverse). In the closed condition shown in FIG. 5 , the flow area is zero, and the sliding sleeve 120 has not moved. Although the flow passages 202 , 206 (shown in FIG. 2 ) may allow for some amount of flow, the second flow passage 204 closes off the seal 200 when the ledges 214 / 254 are engaged.
In a first open condition shown in FIG. 6 , the sliding sleeve 120 is moved upward. The ported sleeve 170 also moved upward because the landing 180 moves by the bias of the spring 182 and pushes the ported sleeve 170 upward. This keeps the seal 200 closed. Eventually, the pins 176 a in the sleeve's slots 176 b limit the travel of the sleeve 170 and landing 180 .
As the sliding sleeve 120 continues to open, it reaches a first equalizing condition shown in FIG. 7 when the sleeve 120 travels from 0.00-in. to about 0.125-in. The ledges 214 / 254 move apart. The length and diametric gap of the ledges 214 / 254 provides for an orifice effect of any flow through the seal 200 . This helps to protect the metal seal surfaces during initial unloading of pressure and flow as described previously. The timing of this orifice effect is minimal as it is needed only during the first movement of separation of the two seal components 210 / 250 . However, the flow passage 202 (See also, FIG. 2 ) from the shelves 212 / 252 act to choke the flow, thereby limiting the actual flow that travels through the seal 200 .
The first flow passage 202 from the first shelves 212 / 252 is extended in comparison to the others so that these shelves 212 / 252 can define a sacrificial component during initial unloading of pressure. As the two sealing components 210 / 250 continue to separate, the external extension from the first flow passage 202 maintains a tight clearance and creates an orifice effect of any flow therethrough. As the sealing shelves 212 / 252 move further apart, the volume and area increases between the two seal components 210 / 250 , thus causing a low pressure area and a drop in flow to develop.
The choke effect from the shelves 212 / 252 continues until the moving component 210 has moved until its distal ledge 211 reaches the end of the first outer shelf 252 as shown in FIG. 8 . Beyond this position, the seal 200 reaches a second equalizing condition when the distal ledge 211 comes to separate from the ledge 254 . When this occurs, the first inner ledge 214 has preferably already passed free of the first ports 174 a in the ported sleeve 170 . Therefore, erosive damage to the ledge 214 used for closed sealing can be reduced. The shelves 212 / 252 and the distal ledge 211 , although they may be subject to more of the erosive flow, are more suited places for such damage to occur. Once the two sealing shelves 212 / 252 slide far enough apart, the movable component 210 becomes disengaged, allowing full flow into the flow port 172 a.
At a subsequent opened conditions after FIG. 8 , the flow through the seal 200 increases as flow ports 174 a are further revealed. Finally, at the opened condition shown in FIG. 9 when the sliding sleeve 120 has traveled to about 2.00-in., the flow area through the ports 174 a is 1% of the flow possible through the diameter of the ported sleeve 170 .
With further movement of the sliding sleeve 120 , more of the ports 174 in the ported sleeve 170 can be revealed. Again, as note previously, the tool has eight discrete positions in which the sliding sleeve 120 can reveal ports 174 on the ported sleeve 170 to control flow between 0%, 1%, 3%, 5%, 7%, 9%, 15%, and 100%. Details on how the sliding sleeve 120 is moved relative to the ported sleeve 170 are discussed below.
C. Hydraulic Activation
As noted previously, the sliding sleeve 120 is moved relative to the ported sleeve 170 . In general, the sliding sleeve 120 can be moved by any of the techniques conventionally used in the art for a flow device. For example, the sliding sleeve 120 can be moved manually using an appropriate pulling tool, hydraulically by a piston arrangement, or other suitable mechanism. In the current implementation, the disclose tool 100 uses a hydraulically actuated ratcheting motion to move the sliding sleeve 120 relative to the ported sleeve 170 . Details of how the tool 100 operates hydraulically are provided in FIGS. 10-14 .
In FIG. 10 , portion of the tool 100 is shown in its closed condition so that the sliding sleeve 120 engages the ported sleeve (not shown) with the sealing arrangement as discussed previously. As shown in FIG. 10 , two control lines 103 a - b connect to hydraulic connections 130 (only one shown) on the tool 100 . Control fluid in the control lines 103 a - b hydraulically move the sliding sleeve 120 relative to the ported sleeve ( 170 ). These control lines 103 a - b run from surface equipment down the tubing string to the tool 100 . When operators apply pressure to an open control line 103 a , the tool's sliding sleeve 120 moves from its current position to a next open position (in the order listed previously). When operators apply pressure to a close control line 103 a , the tool's sliding sleeve 120 moves back completely to its closed position.
In the opening procedure, for example, pressure from the open control line 130 a enters an open port 135 in the housing 110 (i.e., portion 110 b ) and travels to an outlet at a first chamber 132 between the sliding sleeve 120 and the housing portion 110 b . The first chamber 132 is formed by upper and lower seals 123 a - b between the sliding sleeve 120 and housing portions 110 a - b . Fluid pressure fills this first chamber 132 and acts against a shoulder at upper seal 123 b to force the sliding sleeve 120 upward in the housing 110 (i.e., the sleeve 120 moves to the left in FIG. 10 ).
At the same time, fluid pressure from the open port 135 fills a second chamber 134 at another of the port's outlets. Fluid pressure fills this second chamber 134 and acts against a trigger or unlocking sleeve 140 disposed on the sliding sleeve 120 . This unlocking sleeve 140 having a shape of a sleeve seals against the housing portions 110 b - c with upper and lower seals 143 a - b . The fluid pressure moves the unlocking sleeve 140 upward in the housing 110 along the sliding sleeve 120 (i.e., to the left in FIG. 10 ). When moved, the unlocking sleeve 140 acts against the bias of a spring 124 .
The results of this movement are shown in FIG. 11 . As the open control line 130 a supplies fluid pressure to the chambers 132 and 134 , the sliding sleeve 120 moves a first extent inside the housing 110 , and the unlocking sleeve 140 also moves along with the sliding sleeve 120 against the bias of the spring 124 .
A catch 150 having dogs 155 is also disposed on the sleeve 120 . This catch 150 has the shape of a sleeve and has windows for the dogs 155 . As the fluid pressure moves the sliding sleeve 120 , the catch 150 remains in position relative to the housing 110 due to the bias of another spring 126 . Eventually, the sliding sleeve 120 moves a certain distance so that the dogs 155 in the catch 150 engage a shoulder of the first slot 125 a in the sliding sleeve 120 , as shown in FIG. 11 .
Continued pressure at the open control lines 103 a moves the sleeve 120 further in the housing 110 . The catch 150 engaged by dogs 155 in the first groove 125 a also moves upward as shown in FIG. 12 . Once the catch 150 reaches its topmost stroke, it engages an internal shoulder 138 in the housing portion 110 c . This prevents further movement upward of the sliding sleeve 120 .
At this point, the sliding sleeve 120 has opened to its first position (i.e., 1% open) to expose the first ports ( 174 a ) on the ported sleeve ( 170 ) (See FIG. 9 ). To be able to open further, the mechanism is reset. To do this, fluid pressure at the open control line 103 a is released. The trigger 150 is now freed from upward pressure, and the spring 124 biases the trigger or unlocking sleeve 140 downward (i.e., to the right in FIG. 12 ). The end of the unlocking sleeve 140 engages the dogs 155 , freeing them from the slot 125 a as shown in FIG. 13 .
Although fluid pressure at the open control line 130 a is released, the sliding sleeve 120 does not move back downward in the housing 110 . As noted previously and as shown in FIG. 1A , a pair of C-rings 128 a - b help to hold the sliding sleeve 120 when positioned at varying stages along the ported sleeve 170 . A larger C-ring 128 b engages a circumferential groove in the housing portion 110 d to hold the sliding sleeve 120 when in the closed position. The smaller C-ring 128 a engages in a series of smaller circumferential grooves 115 in the housing portion 110 d as the sliding sleeve 120 is moved in stages along the ported sleeve 170 .
Returning to FIG. 13 , the unlocking sleeve 140 engaging the dogs 155 and moved by the spring 124 frees the dogs 155 from the slot 125 a . This allows the catch 150 to reset. As shown in FIG. 14 , the spring 126 pushes the freed catch 150 downward until the dogs 155 engage in the next circumferential slot 125 b on the sliding sleeve 120 .
Further opening of the sliding sleeve 120 can then be achieved through the same process outlined above. Pressure can again be applied to the open control line 103 a , and the sliding sleeve 120 can be ratcheted upward in the housing to the next slotted position by the repeated actions. Release of pressure at the open control line 103 a can then reset the hydraulic components for the next movement. Operated in this manner, the tool 100 can be set to any open condition to vary and control the flow from 1% to 100% at the discrete positions in the present example.
In any of the open conditions, the sliding sleeve 120 can be fully closed on the ported sleeve ( 170 ) to stop flow. As best shown in FIG. 14 , the close control line 103 b connects by another port 137 to a chamber. In this case, the chamber is formed by upper seal 123 a between the sliding sleeve 120 and housing portion 110 a and by lower seal ( 123 c; FIGS. 1A & 9 ) between the sleeve 120 and housing portion 110 d. When operators apply pressure to the close control line 103 b at any time, the tool's sleeve 120 moves back to its fully closed position, which isolates the tubing from the annulus and stops flow through the tool 100 . In the catch 150 , the dogs 155 with their angled edges simply ratchet past the various slots 125 along the sleeve 120 as the sleeve 120 can return to its closed position. Likewise, the C-rings 128 a - b shown in FIG. 1A also ride along the respective grooves 115 in the housing 110 until the larger C-ring 128 b engages in the lowest groove when the sleeve 120 has fully closed. The tool 100 can then be opened by applying pressure to the open control line 103 a according to the previous procedures.
In the current implementation, applying pressure to the close line 103 b closes the tool 100 all the way no matter what current position the sliding sleeve 120 has. In some implementations, closing at discrete positions may be desired. To do this, an entire reverse assembly of a catch, trigger, dogs, chambers, and slots can be provided on the tool 100 opposite to those already shown. When hydraulic pressure is applied to the close line 103 b , these reverse components can operate in the same manner described above, but only in the reverse direction. In this way, the sliding sleeve 120 can ratchet closed in discrete positions. To operate, the reverse (downward) components must accommodate the upward movement of the sliding sleeve 120 from the (upward) components (i.e., catch, trigger, dogs, etc. described previously) and vice versa.
The foregoing description of preferred and other embodiments is not intended to limit or restrict the scope or applicability of the inventive concepts conceived of by the Applicants. In exchange for disclosing the inventive concepts contained herein, the Applicants desire all patent rights afforded by the appended claims. Therefore, it is intended that the appended claims include all modifications and alterations to the full extent that they come within the scope of the following claims or the equivalents thereof. | A downhole flow device has a sliding and ported sleeves. A seal has a first component on the sliding sleeve and a second component on the ported sleeve. These components engage one another to seal flow through the ports in the ported sleeve. The components move apart to allow fluid flow through the ports. The components are protected from abrasion and flow by virtue of the seal's structure and how it is opened. The sliding sleeve moves hydraulically along an axis of the ported sleeve to reveal successive ports defined along the sleeve's axis. Operation of the device and the seal address both erosion and damage from differential pressure problems. Thus, the seal prevent damage when unloading a differential pressure across it, and abrasive flow does not have the opportunity to impinge on the sealing surfaces to cause erosion. | 4 |
FIELD OF THE INVENTION
The field of the invention is directed to methods for preventing and/or treating necrotizing enterocolitis. The field of the invention is further directed to reducing inflammation of the intestinal mucosa associated with necrotizing enterocolitis. The field of the invention is further directed to methods for preventing and/or treating necrotizing enterocolitis and/or inflammation of the intestinal mucosa associated with necrotizing enterocolitis by administering to a subject suffering from such conditions, or at risk of developing such conditions, novel cellular factor-containing solution compositions (referred to herein as “CFS” compositions), including novel sustained-release cellular factor-containing solution compositions (referred to herein as “SR-CFS” compositions).
RELATED ART
Sodhi, C., et al, (Dis Model Mech, 2008, 1 (2-3):94-98) describe the development of animals models for the study of necrotizing enterocolitis.
Mortensen, G. (Master of Art in Nursing Thesis, St. Catherine University, 2011) describes the use of simulated amniotic fluid in preventing feeding intolerance and necrotizing enterocolitis.
Good, M., et al. (PNAS, 2012, 109 (28):11330-11335) describe that amniotic fluid inhibits Toll-like receptor 4 signaling in the fetal and neonatal intestinal epithelium.
Drenckpohl, D., et al. (Pediatrics, 2008, 122; 743-751) describe a randomized trial of very low birth weight infants receiving higher rates of infusion of intravenous fat emulsions during the first week of life.
BACKGROUND OF THE INVENTION
Necrotizing enterocolitis (NEC) is a condition primarily seen in premature infants and occurs when portions of the bowel undergo necrosis (tissue death). Initial symptoms include feeding intolerance, abdominal distension and bloody stools. Symptoms may progress rapidly to abdominal discoloration with intestinal perforation and peritonitis and systemic hypotension requiring intensive medical support, including surgery.
The diagnosis of NEC is usually suspected clinically but often requires the aid of diagnostic imaging modalities such as x-ray. Radiographic signs of NEC include dilated bowel loops, paucity of gas, a “fixed loop” (unaltered gas-filled loop of bowel), pneumatosis intestinalis, portal venous gas, and pneumoperitoneum (“free air” outside the bowel within the abdomen). Recently ultrasonography has proven to be useful as it may detect signs and complications of NEC before they are evident on radiographs.
Current treatment consists primarily of supportive care including providing bowel rest by stopping oral or enteral feeding, gastric decompression with intermittent suction, fluid administration to correct electrolyte imbalances, support for blood pressure, parenteral nutrition, and antibiotic therapy. Where the disease is not halted through medical treatment alone, or when the bowel perforates, immediate emergency surgery to remove the dead bowel is generally required. Surgery may require a colostomy, which may be able to be reversed at a later time. Some children may suffer later as a result of short bowel syndrome if extensive portions of the bowel are removed.
NEC has no definitive known cause. An infectious agent has been suspected, but no common organism has been identified during cluster outbreaks in neonatal hospital units, although Pseudomonas aeruginosa is suspected of causing NEC. Other factors may be involved. The most common area of the bowel affected by NEC is near the ileocecal valve (the site of transition between the small and large bowel). NEC is almost never seen in infants before oral feedings are initiated. Formula feeding increases the risk of NEC by tenfold compared to infants who are fed breast milk alone.
Once an infant is born prematurely, thought must be given to decreasing the risk for developing NEC. Toward that aim, the methods of providing hyperalimentation and oral feedings are both important. A recent study, Drenckpohl, D., et al. (Pediatrics, 2008, 122; 743-751) demonstrated that using a higher rate of lipid (fats and/or oils) infusion for very low birth weight infants in the first week of life resulted in zero infants developing NEC in the experimental group, compared with 14% with NEC in the control group. These finding demonstrate that prevention of NEC is possible.
Typical recovery from NEC if medical, non-surgical treatment succeeds, may take 10-14 days or more without oral intake and then demonstrated ability to resume feedings and gain weight. Recovery from NEC alone may be compromised by co-morbid conditions that frequently accompany prematurity. Long term complications of medical NEC include bowel obstruction and anemia. Despite a significant mortality risk, long-term prognosis for infants undergoing NEC surgery is improving, with survival rates of 70-80%. However, infants who do survive surgery for NEC are at-risk for complications including short bowel syndrome and neuro-developmental disability.
A therapy that could prevent or treat NEC, especially one that could reduce or eliminate the need for surgical intervention, would have a major impact on the treatment, survival and long term health and development of these very ill infants. Accordingly, it is an object of the instant invention to provide such a treatment option.
BRIEF SUMMARY OF THE INVENTION
Applicants have discovered that Amnion-derived Cellular Cytokine Solution (ACCS) (for details see U.S. Pat. Nos. 8,058,066 and 8,088,732, both of which are incorporated herein by reference) exhibits many anti-inflammatory properties, as well as promoting healing in the presence of infection. Therefore, ACCS would be expected to be an effective means of preventing the development of or treating NEC by placing the composition proximal to the site of inflammation on the intestinal lining. The administration of ACCS offers the real possibility that it will be able to effectively inhibit the inflammatory response on the cellular level.
To prevent or treat NEC, the instant invention provides novel cellular factor-containing solution (CFS) compositions, including ACCS, for use in the described methods. The instant invention also provides novel sustained-release cellular factor-containing solution (SR-CFS) compositions, including SR-ACCS, for use in the methods. The instant invention also provides for oral or enteral administration of the CFC compositions. Because the cellular factors are present in the compositions at levels comparable to physiological levels found in the body, they are optimal for use in therapeutic applications which require intervention to support, initiate, replace, accelerate or otherwise influence biochemical and biological processes involved in the treatment and/or healing of disease and/or injury. In the case of the SR-CFS compositions, the cellular factors are released slowly over time to provide a continual, consistent physiologic level of such factors to optimize healing and/or recovery. Detailed information about the compositions used in the methods can be found in U.S. Pat. Nos. 8,058,066 and 8,088,732, both of which are incorporated herein by reference.
Accordingly, a first aspect of the invention is a method for preventing necrotizing enterocolitis in a patient in need thereof comprising administering to the patient a therapeutically effective amount of a CFS composition.
A second aspect of the invention is a method for treating necrotizing enterocolitis in a patient in need thereof comprising administering to the patient a therapeutically effective amount of a CFS composition.
A third aspect of the invention is a method for reducing inflammation of the intestinal mucosa associated with the development of necrotizing enterocolitis in a patient in need thereof comprising administering to the patient a therapeutically effective amount of a CFS composition such that inflammation of the intestinal mucosa is reduced.
A specific embodiment of the invention is one in which the CFS composition is ACCS.
Another specific embodiment is one in which the CFS composition is formulated for enteral administration.
Another specific embodiment is one in which the CFS composition is formulated for intravenous administration.
Another specific embodiment is one in which the CFS composition is formulated for intraperitoneal administration.
Another specific embodiment is one in which the CFS composition that is formulated for enteral administration includes a nutritive infant formula.
Another specific embodiment is one in which the CFS composition is formulated for sustained-release.
DEFINITIONS
As defined herein “isolated” refers to material removed from its original environment and is thus altered “by the hand of man” from its natural state.
As used herein, the term “protein marker” means any protein molecule characteristic of the plasma membrane of a cell or in some cases of a specific cell type.
As used herein, “enriched” means to selectively concentrate or to increase the amount of one or more materials by elimination of the unwanted materials or selection and separation of desirable materials from a mixture (i.e. separate cells with specific cell markers from a heterogeneous cell population in which not all cells in the population express the marker).
As used herein, the term “substantially purified” means a population of cells substantially homogeneous for a particular marker or combination of markers. By substantially homogeneous is meant at least 90%, and preferably 95% homogeneous for a particular marker or combination of markers.
The term “placenta” as used herein means both preterm and term placenta.
As used herein, the term “totipotent cells” shall have the following meaning. In mammals, totipotent cells have the potential to become any cell type in the adult body; any cell type(s) of the extraembryonic membranes (e.g., placenta). Totipotent cells are the fertilized egg and approximately the first 4 cells produced by its cleavage.
As used herein, the term “pluripotent stem cells” shall have the following meaning Pluripotent stem cells are true stem cells with the potential to make any differentiated cell in the body, but cannot contribute to making the components of the extraembryonic membranes which are derived from the trophoblast. The amnion develops from the epiblast, not the trophoblast. Three types of pluripotent stem cells have been confirmed to date: Embryonic Stem (ES) Cells (may also be totipotent in primates), Embryonic Germ (EG) Cells, and Embryonic Carcinoma (EC) Cells. These EC cells can be isolated from teratocarcinomas, a tumor that occasionally occurs in the gonad of a fetus. Unlike the other two, they are usually aneuploid.
As used herein, the term “multipotent stem cells” are true stem cells but can only differentiate into a limited number of types. For example, the bone marrow contains multipotent stem cells that give rise to all the cells of the blood but may not be able to differentiate into other cells types.
As used herein, the term “extraembryonic tissue” means tissue located outside the embryonic body which is involved with the embryo's protection, nutrition, waste removal, etc. Extraembryonic tissue is discarded at birth. Extraembryonic tissue includes but is not limited to the amnion, chorion (trophoblast and extraembryonic mesoderm including umbilical cord and vessels), yolk sac, allantois and amniotic fluid (including all components contained therein). Extraembryonic tissue and cells derived therefrom have the same genotype as the developing embryo.
As used herein, the term “extraembryonic cytokine secreting cells” or “ECS cells” means a population of cells derived from the extraembryonic tissue which have the characteristics of secreting a unique combination of physiologically relevant cytokines in a physiologically relevant temporal manner into the extracellular space or into surrounding culture media and which have not been cultured in the presence of any animal-derived products, making them and cell products derived from them suitable for human clinical use. In a preferred embodiment, the ECS cells secrete the cytokines VEGF, Angiogenin, PDGF and TGFβ2 and the MMP inhibitors TIMP-1 and/or TIMP-2. The physiological range of the cytokine or cytokines in the unique combination is as follows: ˜5-16 ng/mL for VEGF, ˜3.5-4.5 ng/mL for Angiogenin, ˜100-165 pg/mL for PDGF, ˜2.5-2.7 ng/mL for TGFβ2, ˜0.68 μg mL for TIMP-1 and ˜1.04 μg/mL for TIMP-2. The ECS cells may optionally express Thymosin β4.
As used herein, the term “amnion-derived multipotent progenitor cell” or “AMP cell” means a specific population of ECS cells that are epithelial cells derived from the amnion. In addition to the characteristics described above for ECS cells, AMP cells have the following characteristics. They have not been cultured in the presence of any animal-derived products, making them and cell products derived from them suitable for human clinical use. They grow without feeder layers, do not express the protein telomerase and are non-tumorigenic. AMP cells do not express the hematopoietic stem cell marker CD34 protein. The absence of CD34 positive cells in this population indicates the isolates are not contaminated with hematopoietic stem cells such as umbilical cord blood or embryonic fibroblasts. Virtually 100% of the cells react with antibodies to low molecular weight cytokeratins, confirming their epithelial nature. Freshly isolated amnion epithelial cells, from which AMP cells are selected, will not react with antibodies to the stem/progenitor cell markers c-kit (CD117) and Thy-1 (CD90). Several procedures used to obtain cells from full term or pre-term placenta are known in the art (see, for example, US 2004/0110287; Anker et al., 2005, Stem Cells 22:1338-1345; Ramkumar et al., 1995, Am. J. Ob. Gyn. 172:493-500). However, the methods used herein provide improved compositions and populations of cells.
By the term “animal-free” when referring to certain compositions, growth conditions, culture media, etc. described herein, is meant that no non-human animal-derived materials, such as bovine serum, proteins, lipids, carbohydrates, nucleic acids, vitamins, etc., are used in the preparation, growth, culturing, expansion, storage or formulation of the certain composition or process. By “no non-human animal-derived materials” is meant that the materials have never been in or in contact with a non-human animal body or substance so they are not xeno-contaminated. Only clinical grade materials, such as recombinantly produced human proteins, are used in the preparation, growth, culturing, expansion, storage and/or formulation of such compositions and/or processes.
By the term “serum-free” when referring to certain compositions, growth conditions, culture media, etc. described herein, is meant that no animal-derived serum (i.e. no non-human) is used in the preparation, growth, culturing, expansion, storage or formulation of the certain composition or process.
By the term “expanded”, in reference to cell compositions, means that the cell population constitutes a significantly higher concentration of cells than is obtained using previous methods. For example, the level of cells per gram of amniotic tissue in expanded compositions of AMP cells is at least 50 and up to 150 fold higher than the number of cells in the primary culture after 5 passages, as compared to about a 20 fold increase in such cells using previous methods. In another example, the level of cells per gram of amniotic tissue in expanded compositions of AMP cells is at least 30 and up to 100 fold higher than the number of cells in the primary culture after 3 passages. Accordingly, an “expanded” population has at least a 2 fold, and up to a 10 fold, improvement in cell numbers per gram of amniotic tissue over previous methods. The term “expanded” is meant to cover only those situations in which a person has intervened to elevate the number of the cells.
As used herein, “conditioned medium” is a medium in which a specific cell or population of cells has been cultured, and then removed. When cells are cultured in a medium, they may secrete cellular factors that can provide support to or affect the behavior of other cells. Such factors include, but are not limited to hormones, cytokines, extracellular matrix (ECM), proteins, vesicles, antibodies, chemokines, receptors, inhibitors and granules. The medium containing the cellular factors is the conditioned medium. Examples of methods of preparing conditioned media are described in U.S. Pat. No. 6,372,494 which is incorporated by reference in its entirety herein. As used herein, conditioned medium also refers to components, such as proteins, that are recovered and/or purified from conditioned medium or from ECS cells, including AMP cells.
As used herein, the term “cellular factor-containing solution” or “CFS” composition means a composition having physiologic concentrations of one or more protein factors. CFS compositions include conditioned media derived from ECS cells, amnion-derived cellular cytokine solution compositions (see definition below), physiologic cytokine solution compositions (see definition below), and sustained release formulations of such CFS compositions.
As used herein, the term “amnion-derived cellular cytokine solution” or “ACCS” means conditioned medium that has been derived from AMP cells or expanded AMP cells.
As used herein, the term “physiologic cytokine solution” or “PCS” composition means a composition which is not cell-derived and which has physiologic concentrations of VEGF, Angiogenin, PDGF and TGFβ2, TIMP-1 and TIMP-2.
As used herein, the term “suspension” means a liquid containing dispersed components, i.e. cytokines. The dispersed components may be fully solubilized, partially solubilized, suspended or otherwise dispersed in the liquid. Suitable liquids include, but are not limited to, water, osmotic solutions such as salt and/or sugar solutions, cell culture media, and other aqueous or non-aqueous solutions.
The term “lysate” as used herein refers to the composition obtained when cells, for example, AMP cells, are lysed and optionally the cellular debris (e.g., cellular membranes) is removed. This may be achieved by mechanical means, by freezing and thawing, by sonication, by use of detergents, such as EDTA, or by enzymatic digestion using, for example, hyaluronidase, dispase, proteases, and nucleases.
The term “physiologic” or “physiological level” as used herein means the level that a substance in a living system is found and that is relevant to the proper functioning of a biochemical and/or biological process.
As used herein, the term “substrate” means a defined coating on a surface that cells attach to, grown on, and/or migrate on. As used herein, the term “matrix” means a substance that cells grow in or on that may or may not be defined in its components. The matrix includes both biological and non-biological substances. As used herein, the term “scaffold” means a three-dimensional (3D) structure (substrate and/or matrix) that cells grow in or on. It may be composed of biological components, synthetic components or a combination of both. Further, it may be naturally constructed by cells or artificially constructed. In addition, the scaffold may contain components that have biological activity under appropriate conditions.
The term “cell product” or “cell products” as used herein refers to any and all substances made by and secreted from a cell, including but not limited to, protein factors (i.e. growth factors, differentiation factors, engraftment factors, cytokines, morphogens, proteases (i.e. to promote endogenous cell delamination, protease inhibitors), extracellular matrix components (i.e. fibronectin, etc.).
The term “therapeutically effective amount” means that amount of a therapeutic agent necessary to achieve a desired physiological effect (i.e. prevent or treat NEC).
As used herein, the term “pharmaceutically acceptable” means that the components, in addition to the therapeutic agent, comprising the formulation, are suitable for administration to the patient being treated in accordance with the present invention.
As used herein, the term “therapeutic component” means a component of the composition which exerts a therapeutic benefit when the composition is administered to a subject.
As used herein, the term “therapeutic protein” includes a wide range of biologically active proteins including, but not limited to, growth factors, enzymes, hormones, cytokines, inhibitors of cytokines, blood clotting factors, peptide growth and differentiation factors.
As used herein, the term “tissue” refers to an aggregation of similarly specialized cells united in the performance of a particular function.
As used herein, the terms “a” or “an” means one or more; at least one.
As used herein, the term “adjunctive” means jointly, together with, in addition to, in conjunction with, and the like.
As used herein, the term “co-administer” can include simultaneous or sequential administration of two or more agents.
As used herein, the term “agent” means an active agent or an inactive agent. By the term “active agent” is meant an agent that is capable of having a physiological effect when administered to a subject. Non-limiting examples of active agents include growth factors, cytokines, antibiotics, cells, conditioned media from cells, etc. By the term “inactive agent” is meant an agent that does not have a physiological effect when administered. Such agents may alternatively be called “pharmaceutically acceptable excipients”. Non-limiting examples include time release capsules and the like.
As used herein, the term “enteral” administration means any route of drug administration that involves absorption of the drug through the gastrointestinal tract. Enteral administration may be divided into three different categories, oral, gastric, and rectal. Gastric introduction involves the use of a tube through the nasal passage or a tube in the abdomen leading directly to the stomach.
The terms “parenteral administration” and “administered parenterally” are art-recognized and refer to modes of administration other than enteral and topical administration, usually by injection, and includes, without limitation, intravenous, intramuscular, intraarterial, intrathecal, intracapsular, intraorbital, intracardiac, intradermal, intraperitoneal, transtracheal, subcutaneous, subcuticular, intra-articulare, subcapsular, subarachnoid, intraspinal, epidural, intracerebral and intrasternal injection or infusion.
The terms “sustained-release”, “extended-release”, “time-release”, “controlled-release”, or “continuous-release” as used herein means an agent, typically a therapeutic agent or drug, that is formulated to dissolve slowly and be released over time.
“Treatment,” “treat,” or “treating,” as used herein covers any treatment of a disease or condition of a mammal, particularly a human, and includes: (a) preventing the disease or condition from occurring in a subject which may be predisposed to the disease or condition but has not yet been diagnosed as having it; (b) inhibiting the disease or condition, i.e., arresting its development; (c) relieving and or ameliorating the disease or condition, i.e., causing regression of the disease or condition; or (d) curing the disease or condition, i.e., stopping its development or progression. The population of subjects treated by the methods of the invention includes subjects suffering from the undesirable condition or disease, as well as subjects at risk for development of the condition or disease.
As used herein, the term “necrotizing enterocolitis” or “NEC” means a condition primarily seen in premature infants and occurs when portions of the bowel undergo necrosis (tissue death)
As used herein, a “wound” is any disruption, from whatever cause, of normal anatomy (internal and/or external anatomy) including but not limited to traumatic injuries such as mechanical (i.e. contusion, penetrating), thermal, chemical, electrical, radiation, concussive and incisional injuries; elective injuries such as operative surgery and resultant incisional hernias, fistulas, etc.; acute wounds, chronic wounds, infected wounds, and sterile wounds, as well as wounds associated with disease states (i.e. ulcers caused by diabetic neuropathy or ulcers of the gastrointestinal or genitourinary tract). A wound is dynamic and the process of healing is a continuum requiring a series of integrated and interrelated cellular processes that begin at the time of wounding and proceed beyond initial wound closure through arrival at a stable scar. These cellular processes are mediated or modulated by humoral substances including but not limited to cytokines, lymphokines, growth factors, and hormones. In accordance with the subject invention, “wound healing” refers to improving, by some form of intervention, the natural cellular processes and humoral substances of tissue repair such that healing is faster, and/or the resulting healed area has less scaring and/or the wounded area possesses tissue strength that is closer to that of uninjured tissue and/or the wounded tissue attains some degree of functional recovery.
As used herein the term “standard animal model” refers to any art-accepted animal model in which the compositions of the invention exhibit efficacy.
DETAILED DESCRIPTION
In accordance with the present invention there may be employed conventional molecular biology, microbiology, and recombinant DNA techniques within the skill of the art. Such techniques are explained fully in the literature. See, e.g., Sambrook et al, 2001, “Molecular Cloning: A Laboratory Manual”; Ausubel, ed., 1994, “Current Protocols in Molecular Biology” Volumes I-III; Celis, ed., 1994, “Cell Biology: A Laboratory Handbook” Volumes I-III; Coligan, ed., 1994, “Current Protocols in Immunology” Volumes I-III; Gait ed., 1984, “Oligonucleotide Synthesis”; Hames & Higgins eds., 1985, “Nucleic Acid Hybridization”; Hames & Higgins, eds., 1984, “Transcription And Translation”; Freshney, ed., 1986, “Animal Cell Culture”; IRL Press, 1986, “Immobilized Cells And Enzymes”; Perbal, 1984, “A Practical Guide To Molecular Cloning.”
Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges is also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either both of those included limits are also included in the invention.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, the preferred methods and materials are now described.
It must be noted that as used herein and in the appended claims, the singular forms “a,” “and” and “the” include plural references unless the context clearly dictates otherwise.
Compositions and Methods of Making Compositions
Detailed information and methods on the preparation of AMP cell compositions, generation of ACCS, generation of pooled ACCS, detection of cytokines in non-pooled and pooled ACCS using ELISA, generation of PCS compositions, and generation of sustained-release CFS compositions can be found in U.S. Pat. Nos. 8,058,066 and 8,088,732, both of which are incorporated herein by reference.
The invention provides for an article of manufacture comprising packaging material and a pharmaceutical composition of the invention contained within the packaging material, wherein the pharmaceutical composition comprises CFS compositions, including ACCS. The packaging material comprises a label or package insert which indicates that the CFS compositions, including ACCS, contained therein can be used for therapeutic applications such as, for example, preventing or treating NEC.
Formulation, Dosage and Administration of CFS Compositions
Compositions comprising CFS compositions may be administered to a subject to provide various cellular or tissue functions, for example, to prevent or treat NEC. As used herein “subject” may mean either a human or non-human animal.
Such compositions may be formulated in any conventional manner using one or more physiologically acceptable carriers optionally comprising excipients and auxiliaries. Carriers for CFS compositions may include but are not limited to solutions of normal saline, phosphate buffered saline (PBS), lactated Ringer's solution containing a mixture of salts in physiologic concentrations, or cell culture medium. Proper formulation is dependent upon the route of administration chosen. For enteral administration, the CFS compositions may be administered directly to the patient without any manipulation, formulation or additives or they may be combined with nutritive infant formulas. Such combinations may include the addition of the CFS composition to the nutritive infant formula. Alternatively, a powdered nutritive formula may be reconstituted in the CFS composition. Exemplary nutritive infant formulas include Enfamil® Premature 24 infant formula, Gerber® Good Start® Premature 24 infant formula, and Similac® Special Care® 24 with Iron infant formula. Other routes of administration are also contemplated by the methods of the invention. For example, in certain instances intravenous administration of the CFS compositions may be suitable. CFS combinations may also be prepared by coating with delayed release or targeted release polymers. These polymers can be designed to time the delivery of the CFS combinations to different parts of the gastrointestinal tract. For example, poly(meth)acrylates, commercially known as EUDRAGIT®, are used to coat tablets, capsules and microparticulate dosage forms. These polymers dissolve at specific pH ranges and therefore can be used to deliver CFS combinations to different parts of the gastrointestinal tract. Thus, EUDRAGIT® L 30 D-55 30% aqueous dispersion or L 100-55 powder will dissolve at pH's greater than 5.5 and are effective for drug delivery in the duodenum (Jaana Harmoinen, Kirsi Vaali, Pertti Koski, Kaisa Syrjänen, Outi Laitinen, Kai Lindevall, Elias Westermarck, Enzymic degradation of a β-lactam antibiotic, ampicillin, in the gut: a novel treatment modality, Journal of Antimicrobial Chemotherapy (2003) 51, 361-365, Md. A. Rahman and J. Ali, Development and in vitro Evaluation of Enteric Coated Multiparticulate System for Resistant Tuberculosis, Indian J Pharm Sci. 2008 July-August; 70 (4): 477-481). EUDRAGIT® L 12.5 12.5% organic solution or L 100 powder, will dissolve above pH 6.0 and are effective for drug delivery in jejunum (Pia Munkholm, 5-aminosalicylic Acid and Colorectal Cancer Prevention in Inflammatory Bowel Disease, European gastroenterology & hepatology review, 2011; 7 (3):160-5). EUDRAGIT® FS 30 D 30% aqueous dispersion, or S 12.5 12.5% organic solution, or S 100 powder will dissolve above pH 7.0 and are effective for colonic delivery (ibid). Intraperitoneal administration may also be indicated. Ultimately, the appropriate route of administration will need to be empirically determined by the treating physician.
In addition, one of skill in the art may readily determine the appropriate dose of the CFS compositions for a particular purpose. A preferred dose is in the range of about 0.1-to-1000 micrograms per square centimeter of applied area. Other preferred dose ranges are 1.0-to-50.0 micrograms/applied area. In a particularly preferred embodiment, it has been found that relatively small amounts of the CFS compositions are therapeutically useful. One exemplification of such therapeutic utility is the ability for ACCS (including pooled ACCS) to accelerate wound healing (for details see U.S. Publication No. 2006/0222634 and U.S. Pat. No. 8,187,881, both of which are incorporated herein by reference). One of skill in the art will also recognize that the number of doses to be administered needs also to be empirically determined based on, for example, severity and type of disease, disorder or injury being treated; patient age, weight, sex, health; other medications and treatments being administered to the patient; and the like. For example, in a preferred embodiment, one dose is sufficient to have a therapeutic effect (i.e. prevent or treat NEC). Other preferred embodiments contemplate, 2, 3, 4, or more doses for therapeutic effect.
One of skill in the art will also recognize that number of doses (dosing regimen) to be administered needs also to be empirically determined based on, for example, severity and type of injury, disorder or condition being treated; patient age, weight, sex, health; other medications and treatments being administered to the patient; and the like. In addition, one of skill in the art recognizes that the frequency of dosing needs to be empirically determined based on similar criteria. In certain embodiments, one dose is administered every day for a given number of days (i.e. once a day for 7 days, etc.). In other embodiments, multiple doses may be administered in one day (every 4 hours, etc.). Multiple doses per day for multiple days is also contemplated by the invention.
In further embodiments of the present invention, at least one additional agent may be combined with the CFS compositions. Such agents may act synergistically with the CFS compositions of the invention to enhance the therapeutic effect. Such agents include but are not limited to growth factors, cytokines, chemokines, antibodies, inhibitors, antibiotics, immunosuppressive agents, steroids, anti-fungals, anti-virals or other cell types (i.e. stem cells or stem-like cells, for example AMP cells). Inactive agents include carriers, diluents, stabilizers, gelling agents, delivery vehicles, ECMs (natural and synthetic), scaffolds, and the like. When the CFS compositions are administered conjointly with other pharmaceutically active agents, even less of the CFS compositions may be needed to be therapeutically effective.
CFS compositions may also be inserted into a delivery device, e.g., a tube, a syringe, in different forms. For example, the CFS compositions can be part of a solution contained in such a delivery device. As used herein, the term “solution” includes a pharmaceutically acceptable carrier or diluent. Pharmaceutically acceptable carriers and diluents include saline, aqueous buffer solutions, solvents and/or dispersion media. The use of such carriers and diluents is well known in the art. The solution is preferably sterile and fluid to the extent that easy syringability exists. Preferably, the solution is stable under the conditions of manufacture and storage and may optionally be preserved against the contaminating action of microorganisms such as bacteria and fungi through the use of, for example, parabens, chlorobutanol, phenol, ascorbic acid, thimerosal, and the like. Solutions of the invention can be prepared by incorporating the CFS compositions in a pharmaceutically acceptable carrier or diluent and, as required, other ingredients enumerated above.
The timing of administration of CFS compositions will depend upon the type and severity of the disease, disorder, or injury being treated. In one embodiment, the CFS compositions are administered as soon as possible after diagnosis of NEC or surgical intervention. In another embodiment, CFS compositions are administered more than one time following diagnosis or surgical intervention. In certain embodiments, where surgery is required, the CFS compositions are administered at surgery. In still other embodiments, the CFS compositions are administered at as well as after surgery. Such post-surgical administration may take the form of a single administration or multiple administrations.
Support matrices, scaffolds, membranes and the like into which the CFS compositions can be incorporated or embedded include matrices which are recipient-compatible and which degrade into products which are not harmful to the recipient. Detailed information on suitable support matrices, etc. can be found in U.S. Pat. Nos. 8,058,066 and 8,088,732, both of which are incorporated herein by reference.
A “therapeutically effective amount” of a therapeutic agent within the meaning of the present invention will be determined by a patient's attending physician or veterinarian. Such amounts are readily ascertained by one of ordinary skill in the art and will enable preventing or treating NEC when administered in accordance with the present invention. Factors which influence what a therapeutically effective amount will be include, the specific activity of the therapeutic agent being used, the extent of the injury, diseased tissue or surgical wound, the absence or presence of infection, time elapsed since the surgery, and the age, physical condition, existence of other disease states, and nutritional status of the patient. Additionally, other medication the patient may be receiving will effect the determination of the therapeutically effective amount of the therapeutic agent to administer.
EXAMPLES
The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the compositions and methods of the invention, and are not intended to limit the scope of what the inventors regard as their invention. Efforts have been made to ensure accuracy with respect to numbers used (e.g., amounts, temperature, etc.) but some experimental errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, molecular weight is average molecular weight, temperature is in degrees centigrade, and pressure is at or near atmospheric.
The following examples provide evidence of the anti-inflammatory and wound healing effects of ACCS is several different inflammatory disease states (mucosal/infected; skin (intact and lesioned); and cutaneous wound/infected), thus providing strong evidence for the broad applicability of ACCS to treat inflammatory diseases.
Example 1
Inflammatory Model—Use of ACCS to Prevent Onset of Periodontal Disease in an Animal Model
Objective:
The aim of this study was to evaluate the preventive role of ACCS in Porphyromonas gingivalis ( P. gingivalis )-induced experimental periodontitis in rabbits
Methods:
Eight New-Zealand White rabbits were distributed into 3 groups: 1. Untreated (n=2), 2. Control (unconditioned ACCS culture media) (n=3), and 3. ACCS (n=3). At baseline, all rabbits received silk ligatures bilaterally tied around mandibular second premolars under general anesthesia. The assigned test materials, ACCS or control, in volumes of 10 μL were topically applied to the ligated sites with a blunt needled-Hamilton Syringe from the time of ligature; control animals received ligature, but no treatment. Topical P. gingivalis -containing slurry (1 mL) was subsequently applied to induce the periodontal inflammation. The application of test materials and P. gingivalis continued for 6 weeks on an every-other-day schedule. At 6 weeks, following euthanasia, the mandibles were surgically harvested. Morphometric, radiographic and histologic evaluations were performed.
Results:
Macroscopic evaluations including soft tissue assessments, crestal bone and infrabony measurements showed significant periodontal breakdown induced by P. gingivalis in control and no treatment groups at 6 weeks compared to historical ligature-alone groups (p=0.05, p=0.03, respectively). ACCS application significantly inhibited soft tissue inflammation and prevented both crestal bone loss and infrabony defect formation compared to untreated and control groups (p=0.01, p=0.05, respectively). Histologic assessments and histomorphometric measurements supported the clinical findings; ACCS treated animals demonstrated significantly less inflammation in soft tissue and less bone loss compared to the untreated and control groups (p=0.05).
Conclusions:
Topical ACCS application prevents periodontal inflammatory changes and bone loss induced by P. gingivalis as shown both at clinical and histopathological level. ACCS has potential as a therapeutic approach for the prevention of periodontal diseases
Example 2
Inflammatory Model—Use of ACCS to Stop Progression of or Reverse Periodontal Disease in an Animal Model
Objective:
The aim of this study was to evaluate the therapeutic actions of ACCS in the treatment of periodontitis induced by P. gingivalis.
Methods:
The study was conducted using a two-phase rabbit periodontitis protocol: 1—Disease induction (6 weeks) and 2—Treatment (6 weeks). Periodontal disease was induced in 16 New-Zealand White rabbits by every-other-day application of topical P. gingivalis to ligatured mandibular premolars. At the end of Phase 1, 4 randomly selected rabbits were sacrificed to serve as the baseline disease group. For Phase 2, the remaining 12 rabbits were distributed into 3 groups (n=4), 1—Untreated, 2—Control (unconditioned ACCS culture media) and 3—ACCS treatment. At the end of Phase 2, morphometric, radiographic and histologic evaluations were performed on harvested mandibles.
Results:
The baseline disease group exhibited experimental periodontitis evidenced by tissue inflammation and bone loss. At the end of Phase 2, the untreated group showed significant disease progression characterized by increased soft and hard tissue destruction (p=0.05). The tissue inflammation and bone loss was significantly reduced by topical ACCS compared to baseline disease and untreated groups (p=0.05; p=0.002, respectively). The control treatment also arrested disease progression compared to untreated group (p=0.01), but there was no improvement in periodontal health compared to baseline disease (p=0.4). Histopathological assessments revealed similar findings; ACCS stopped the progression of inflammatory process (p=0.003) and reversed bone destruction induced by P. gingivalis (p=0.008). The ACCS-treated group had minimal osteoclastic activity limited to crestal area compared to untreated and control groups, which showed a profound osteoclastogenic activity at the bone crest as well as at interproximal sites.
Conclusions:
Topical application of ACCS stopped the progression of periodontal inflammation and resulted in tissue regeneration in rabbit periodontitis indicating its potential therapeutic efficacy.
Example 3
Evaluate the efficacy of Topically Applied ACCS to Inhibit Irritant 12-O-Tetradecanoylphorbol-13-Acetate (TPA) Skin Inflammation in Mice
Method: Topical treatment was given twice daily to the following groups: 1. TPA+topical control; 2. TPA+ACCS; 3. TPA+clobetasol 0.05 topical solution (the strongest available topical corticosteroid); 4. ACCS alone; 5. No treatment (the other untreated ear was measured). The endpoints for the study were ear thickness and ear weight at the end of the experiment. The thicker the ear and the more it weighs correlates with the degree of inflammation.
Results: Topically applied ACCS was effective at reducing the inflammation induced by TPA. The anti-inflammatory activity of topical ACCS reached the same level as clobetasol (a class 1 potent topical corticosteroid) by 3 days after beginning application.
Conclusion: ACCS has a strong anti-inflammatory effect when applied to skin.
Example 4
Evaluate the Efficacy of Intralesional Injection of ACCS to Inhibit Irritant (TPA) Skin Inflammation in Mice
Method: Intralesional injection into the ear was given once daily to the following groups: 1. TPA+intralesional control; 2. TPA+intralesional ACCS; 3. TPA+intralesional kenalog (10 mg/ml) (a potent intralesional corticosteroid); 4. ACCS intralesional injection alone; 5. Saline sham injections to the normal untreated ear. The endpoints for the study were ear thickness and ear weight at the end of the experiment. The thicker the ear and the more it weighs correlates with the degree of inflammation.
Results: Intralesional injection of ACCS was effective at reducing the inflammation induced by TPA at all time points beginning on day 2 of daily injections. Intralesional kenalog (10 mg/ml) injections induced a hematoma at the site of injection, which led to some inflammation and that is why there is not a substantial difference in ear thickness when comparing TPA+kenalog with TPA+control.
Conclusions: Intralesional ACCS did reduce skin inflammation but the topically applied ACCS in Example 1 above had a more potent effect. There was no difference in ear weight using either ACCS or intralesional kenalog compared with TPA+control.
Example 5
Effects of ACCS in an Animal Model of Chronic Wound Healing
An art-accepted animal model for chronic granulating wound was used to study the effects of ACCS on chronic wound healing (Hayward P G, Robson M C: Animal models of wound contraction. In Barbul A, et al: Clinical and Experimental Approaches to Dermal and Epidermal Repair: Normal and Chronic Wounds. John Wiley & Sons, New York, 1990.).
Results: ACCS was effective in not allowing proliferation of tissue bacterial bioburden. ACCS allowed accelerated healing of the granulating wound significantly faster than the non-treated infected control groups (Franz, M., et al., ePlasty Vol. 8, pp. 188-199, Apr. 11, 2008).
Example 6
Effects of ACCS in Animal Models of Necrotizing Enterocolitis (NEC)
Sodhi, C., et al, (Dis Model Mech, 2008, 1 (2-3):94-98) describe the development of animal models for the study of necrotizing enterocolitis. ACCS is tested in these animal models to evaluate its ability to prevent or treat necrotizing enterocolitis (NEC).
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.
Throughout the specification various publications have been referred to. It is intended that each publication be incorporated by reference in its entirety into this specification. | The invention is directed to methods for preventing and/or treating necrotizing enterocolitis. The invention is further directed to reducing inflammation of the intestinal mucosa associated with necrotizing enterocolitis. The invention is further directed to methods for preventing and/or treating necrotizing enterocolitis and/or inflammation of the intestinal mucosa associated with necrotizing enterocolitis by administering to a subject suffering from such conditions, or at risk of developing such conditions, cellular factor-containing solution compositions (referred to herein as “CFS” compositions), including sustained-release cellular factor-containing solution compositions (referred to herein as “SR-CFS” compositions). | 0 |
BACKGROUND OF THE INVENTION
The invention relates in general to a system for scanning vibrations of a mass, and for converting such mechanical vibrations, particularly of strings of musical instruments such as guitars, harps, pianos, and the like, into corresponding alternating electrical signals.
In a scanning system of this kind disclosed in German DE-OS 29 16 684, a part of the vibrating body is arranged in the path of a light beam and cooperates with a stationary body in such a manner that a gap is created between the vibrating and stationary bodies. This gap is variable in accordance with the vibrations of one of these bodies, so that, depending on the amplitude of the vibrations broad or a narrow strip is illuminated on the active surface of a converter. According to the size of the activated surface of the converter the corresponding voltage signals are generated. This known scanning system, however, permits only the scanning of such mechanical vibrations whose amplitudes are directed to the stationary body. Vibrations occurring in another plane oriented in the longitudinal direction of the gap between the vibrating and stationary bodies can be detected only by using two converters with two light gaps arranged at right angles one to another. Even in this arrangement it is possible to scan vibrations in respective planes only, whereas scanning of vibrations in longitudinal direction of the light beam is not possible.
SUMMARY OF THE INVENTION
It is therefore a general object of the present invention to overcome the aforementioned disadvantages.
More particularly, it is an object of the invention to provide an improved vibration scanning system which is not possessed of these disadvantages.
An additional object of the invention is to provide such an improved scanning system which permits the conversion of mechanical vibrations in the longitudinal direction of the scanning light beam.
In keeping with these objects and others which will become apparent hereafter, one feature of the invention resides, in a vibration scanning system of the aforedescribed kind, in a combination which comprises means for directing a narrow radiation beam against the path of the vibrating mass whose cross section is less than the cross section fo the beam, and the part of the active surface of the converter which is arranged in the path of the beam behind the vibrating mass part has such a configuration that, due to the lateral displacement of the umbra of the vibrating part, the illuminated portion of the active surface varies in size. Due to the smaller cross section of the vibrating mass part with respect to the cross section of the scanning radiation beam, the amplitudes of vibrations in a plane oriented in the longitudinal direction of the radiation beam produce on the active surface of the converter an umbra which periodically changes its size, so that even this vibrating mode is detectable. In another vibrating mode, when the mass part vibrates at right angles to the longitudinal direction of propagation of the radiation beam, there occurs always a lateral displacement of the umbra on the active surface of the converter, and these vibrations can be reliably detected.
The active surface of the converter exposed to the radiation beam may have a circular configuration. In this simple manner, it is achieved that, when the umbra of the vibrating mass part is displaced laterally to the circular rim of the active surface, it is reduced in size and consequently the proportion of the active surface exposed to the radiation becomes larger in size. As a consequence, due to this lateral displacement of the umbra, a corresponding variation of the voltage at the output of the converter is generated.
In a variation, the ray beam impinging on the active surface of the converter may also have a circular cross section. In this manner it is also achieved in a simple way that a lateral displacement of the vibrating body a smaller part of the active surface is shaded off, while the exposed active area becomes proportionally larger and so is the signal at the output of the converter.
In the plane of propagation of the ray beam, it is possible to arrange one after the other a plurality of vibrating bodies whose cross sections fall below the cross section of the radiation beam. The umbras of respective vibrating bodies superpose each other on a common active surface of the converter. Nevertheless, the superposed umbras generate a compound alternating voltage during the vibration of individual bodies.
With advantage an optical system can be arranged between the converter and the vibrating mass part for focussing the illuminating radiation beam to a smaller cross-sectional area. This optical device can be in the form of a collecting lens. In this manner it is possible to use a relatively small illumination surface at the side of the converter, whereas the radiation source can transmit a ray beam towards the converter which in the range of the vibrating mass part may have a substantially larger cross-sectional area. In addition, it is also advantageous when the collecting lens has a circular periphery, so that the ray beam projected on the active area of the converter has a circular cross section.
If desired, it is also possible to arrange between the converter and the vibrating mass part an optical device, preferably in the form of a diverging lens which disperses the ray beam on a larger cross-sectional area of the active surface. In this manner, it is possible to scan with a very narrow beam to detect very small vibrational amplitudes. By dispersing the ray beam on a larger cross-sectional area, the displacement of the umbra on the active surface of the converter is magnified.
In another embodiment, a radiation conduit, preferably in the form of a flexible light-conducting fiber can be arranged between the active surface of the converter and the optical device for transforming the cross-sectional area of the ray beam. In this way it is achieved that the optoelectric converter need not be arranged immediately behind the device for transforming the cross section of the radiation beam. The provision of light conduits makes it possible that the converter can be located outside interfering electromagnetic fields.
The electrical signal at the output of the converter can be processed in a transformer into an effective signal which may be applied to a pneumatic or the like control member.
When the system of this invention is used in connection with musical instruments, the output signal from the converter is amplified in an amplifier, and converted in a speaker into an acoustic signal.
The converted electrical signals from the output of the converter, after amplification and conversion in at least one speaker into audible signals, reproduce the sounds of strings of a guitar, of a harp, of a piano, and the like.
In scanning the vibrations of strings of the above musical instruments the radiation beam is directed at right angles to the strings which are arranged in one plane one after the other. The scanning system of this invention picks up in simple manner the vibrations of all consecutive strings.
In one embodiment of this invention, the radiation source is a light source in the form of an incandescent lamp provided with means for directing a light beam against the vibrating mass parts.
Preferably, the light source is connected to adjusting means which adjust the light beam symmetrically relative to the plane of the consecutive strings. Preferably, the light beam is enclosed in a U-shaped cover provided with openings for individual strings, so that the light beam and the focussing optical system with the series-connected converter is protected against ambient light, so that the latter cannot produce any interference.
The novel features which are considered characterisitic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a top view of a guitar provided with the vibration scanning system of this invention;
FIG. 2 is a sectional side view taken along the line II--II of the guitar of FIG. 1, shown on an enlarged scale;
FIG. 3 is a schematic representation of a scanning light beam emanating from a light source and directed in a plane of a set of guitar strings against a converging lens;
FIG. 4 shows in a front view the collecting lens with partially shaded off areas of the light beam behind the strings;
FIG. 5 is an illustration corresponding to FIG. 3, with strings vibrating transversely to the direction of propogation of the light beam;
FIG. 6 is a view of the collecting lens of FIG. 4 with a laterally displaced shaded off area of the light beam behind the vibrating strings;
FIG. 7 is an illustration corresponding to FIG. 3 in which the strings vibrate in a plane coinciding with the direction of propagation of the light beam;
FIG. 8 is a view of the collecting lens similar to FIG. 4 showing the shaded off area or umbra of a string in one momentary position of its parallel vibrations;
FIG. 9 is an illustration similar to FIG. 7 but in which two strings have different amplitudes in the vibration plane parallel to the direction of propagation of the light beam;
FIG. 10 is a front view of the collecting lens similar to FIG. 8, showing the changed umbra of the vibrating strings;
FIG. 11 shows a modification of FIG. 9 in which the collecting lens is replaced by a dispersing lens.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The scanning system of this invention is illustrated in connection with a guitar 20 consisting of a guitar body 21, a fretted neck 22 and strings 23-28 each secured at one end to the guitar body by non-illustrated catches and extending over the neck to screw-type pegs 29 by means of which the strings are tuned (FIG. 1). The scanning system of this invention is attached to the guitar body 21 above the strings and serves for scanning the vibrations of the strings and converting the same into amplified audible signals.
Referring now to FIG. 2, it will be seen that the scanning system consists of a radiation source, in this example in the form of a light source 30 constituted for example by an incandescent lamp 31. The lamp 31 is energized from a battery 32 which may be located in a recess 33 in the lower side of the guitar body 21. The current supply conduits from the battery to the incandescent lamp are connected via a switch 34 located on the upper surface of the guitar body to switch on or off the operation of the system.
A radiation beam, namely the light beam 35 emanating from the light source 30, is directed against a converging or focussing lens 36 (FIGS. 3-10). The centers of the light source 30 of the lens 36 are arranged in the plane of the set of strings 23-28 at opposite sides of the latter. The diameter of the light source 30 is larger than the diameters of respective strings, and consequently a converging umbra is formed behind each of the strings. Due to the consecutive arrangement of the strings in one plane, the umbras of respective strings combine with each other and project a single shaded off strip on the collecting lens 36.
In playing the guitar 20 one or more strings 23-28 are brought to vibration, and consequently the umbra of the vibrating string is projected on the collecting lens 36 as a shaded off strap vibrating at the same frequency. As a consequence, the illuminated area of the light collecting lens 36 varies complementary to the increasing and decreasing breadth of the shaded off strap.
It will be seen from FIG. 2 that the focussing lens 36 projects the incoming light pattern on a relatively small cross-sectional area at the end face of a light guide 37. The light guide 37 is in the form of a light-conducting fiber by means of which the light focussed by the lens 36 is supplied to an optoelectric converter 38, which converts the light into corresponding alternating electrical voltage. Of course, it is also possible to pick up the light projected by the focussing lens 36 directly to the optoelectric converter 38. In the latter case, however, the minute voltages at the output of the converter must be amplified in a non-illustrated amplifier, whereby the electrical conduits are exposed to electromagnetic fields which may introduce interference in the useful signal. On the other hand, in using ight conduits the picked-up light signals are not susceptible to interference and can be fed to a remote electro-optical converter which in this case is arranged in close proximity to the electric amplifier. The amplifier is further connected to a non-illustrated loudspeaker system which converts the amplified electrical signal into useful acoustic signals corresponding to the vibrations of strings 23-28.
It will be seen from FIG. 2 that the lamp 31 is mounted on a holder 39 which is adjustable at right angles to the plane of strings 23-28 by an adjustment screw 40. By rotating the actuation knob 41 of the screw 40 the vertical position of the lamp 31 relative to the string is changed, and consequently the symmetry of the light beam 35 relative to the plane of the strings 23-28 is adjustable.
The scanning light beam 35 transmitted from the light source past the strings 23-28 against a collecting lens 36 is enclosed in a cover 42 provided with openings 43 for respective strings. The cover 42 protects the scanning system against ambient light which might fall on the collecting lens and interfere with the scanning process.
For the sake of simplicity, only the end portions 44 and 45 of the light conduit 37 are illustrated in FIG. 2. As explained before, the input end 44 of the light conduit 37 is located immediately behind focus point of the lens 36, whereas the output end 45 is connected to a plug 46 in which an electro-optical converter 38 is enclosed. The connector plug 46 is adapted for being directly connected to a non-illustrated electric amplifier.
As has been explained before, the scanning system of this invention uses a scanning light beam which is directed parallel to the plane of consecutively arranged strings of a guitar, for example, so that the umbras of respective strings overlap each other. Surprisingly, it has been found that the superposed umbras in the path of propagation of the light beam 35 are sufficient to produce modulated voltages in the optoelectric converter, which upon amplification and reproduction in a loudspeaker produce clear and pure tones of individual guitar strings 23-28.
The reason for this phenomenon might be the fact that each guitar string 23-28 casts its own umbra. In FIGS. 3 and 4, this is illustrated with reference to strings 24 and 27. Immediately behind the guitar string 24 an umbra 47 is cast devoid of any light from the light source 30. However, due to the diameter difference between the light source and the string, the umbra is relatively short and does not reach the focussing lens 36. Nevertheless, half shaded regions are generated besides and behind the umbra 47 which are not illuminated by the full radiating surface of the light source 30. The more half shades are superimposed behind the strings 23-28, the darker are these regions at the receiving surface of the converging lens 36.
As seen from FIG. 4, a horizontal dark band extending in the center region of the collecting lens 36 represents the combined half shades of consecutively arranged strings 24 and 27. In this example, the shadows cast by guitar strings 23, 25, 26 and 28 are not considered. Below and under the central dark, horizontal band, there are produced additional bands which are somewhat brighter and result from the combined half shades.
FIG. 5 illustrates by a full line the guitar string 24 in a position in which it is displaced in vertical direction relative to its neutral position. The shaded off areas formed on the surface of the collecting lens 36 produce a different pattern having different brightness values. Due to the displacement of the dark band towards the curved rim of the lens, larger areas of the lens are illuminated and the converter 38 produces higher voltage. These voltage differences correspond exactly to the frequency of vibration of the corresponding string.
From FIGS. 4 and 6, it is evident that, by vibrating the strings 24 and 27 transversely to the direction of propagation of the light beam, the dark bands projected on the collecting lens 36 are periodically shifted to the upper and lower sides of the lens. Due to the circular shape of the lens, there are produced differences in the illumination of the collecting lens and hence of the active surface of the converter without changing the width of the dark bands. More specifically, the dark band illustrated in FIG. 6 occupies a smaller area of the total surface of the collecting lens 36 than the equally wide dark band projected across the center region of the circular collecting lens. The more remote is the shaded off band from its center position, the more it is reduced in size by the converging rounded rim of the lens when viewed in the direction of movement of the band, and the higher voltages are converted due to the increased illumination of the active surface of the converter. According to further feature of the scanning system of this invention, the scanning action is not impaired even if the strings 23-28 do not vibrate at right angles to the direction of propagation of the light beam 35. The scanning system of this invention is fully operative even if the strings vibrate fully or partially in the direction of propagation of the beam, that is in the common plane of the string set. This feature is explained in more detail with reference to FIGS. 5-10. In FIG. 7, the strings 24 and 27 are illustrated by full lines in a vibrational position in which the amplitude of the string is directed away from the rest position of the string in the direction of propagation of the light beam. In FIG. 9, in contrast, the strings 24 and 27 are illustrated at a moment of their vibrations when their amplitude is directed in the plane of propagation of the light beam towards the light source 30. In this mode of vibrations in which the strings 24 and 27 are displaced parallel to the light beam 35, there result different shaded off areas on the collecting lens which is different from the pattern shown in FIG. 3. The differences in the shade patterns according to FIGS. 3, 7 and 9 result also in correspondingly different voltages at the output of converter 38, producing also after amplification and transformation, different acoustic signals. As seen from FIG. 8, the dark band at the center of the lens 36 is more narrow than the dark band according to FIG. 4. This can be explained from the increased distance of strings 24 and 27 from the light source 30 (FIG. 7). The dark band shown in FIG. 10 is broader than that in FIG. 4, because in this case the strings 24 and 27 are displaced closer to the light source 30.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
For instance, the scanning system of this invention is equally applicable for amplifying acoustic oscillations of other string instruments such as harps, pianos and the like. Moreover, the light beam transmitted from the light source can be substituted by other radiation beams, such as an infrared or ultraviolet light beam which is invisible to the eye. Also, laser beams, roentgen beams, and the like, are conceivable. The invention is not limited to scanning of solid materials such as strings of musical instruments. It is also applicable for gaseous or liquid substances provided that they can cast shadows. For scanning vibrations of very small amplitudes, the scanning radiation beam is made very thin, and to magnify the projections on the shaded off areas, a dispersion lens 36, is used to increase the illuminated surface, as shown in FIG. 11. The scanning system of this invention is also applicable for detecting other mechanical vibrations which are beyond the range of audio frequencies. In this case, the vibrations of matter are converted into electrical signals which serve in frequency meters, amplitude meters, and the like.
While the invention has been illustrated and described as embodied in a scanning system for use with musical instruments, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | A system for scanning vibrations of a mass and for converting the mechanical vibrations into corresponding electrical signals is disclosed. The system includes a source of a scanning radiation beam, preferably of a light beam, which has a larger transverse cross section than the vibrating mass. The umbra behind the mass and the surrounding illuminated area are collected by a focussing lens and projected onto an optoelectric converter. The collecting surface and/or the active light receiving surface of the converter have an outline which is variable in the direction of displacement of the vibrating mass so that the illuminated area varies in size during the vibration of the mass. | 6 |
FIELD OF THE INVENTION
This invention relates to a thinwall guide catheter for insertion into body vessels to deliver a therapeutic device to a selected site and, more specifically, to an improved guide catheter and method of making, the guide catheter having a thinner wall and excellent stiffness, kink resistance and torque transfer characteristics.
BACKGROUND OF THE INVENTION
Present guide catheters generally are formed as a three layer composite tube. A liner is utilized to provide a lubricious surface to aid in device passage through the lumen of the guide. The next layer is a braid material, typically a stainless steel round wire braid, which is positioned directly over the liner. An outer jacket encapsulates the braid and is bonded to the liner through braid interstices to create a monolithic structure from the three components. Typically a liner made in this manner is about 0.002 in. thick, the braid is 0.002 in. thick (0.004 at the crossovers) and the outer jacket thickness is dictated by the outside diameter of the catheter. Typical overall guide catheter wall thicknesses are about 0.010 in., providing a 0.086 in. diameter lumen on an about 0.106 in. catheter. Thinner guide catheter walls are desirable to provide maximum lumen diameter for passage of therapeutic devices.
Guide catheters are typically used in procedures such as percutaneous transluminal coronary angioplasty (PTCA) which are intended to reduce arterial build-up of cholesterol fats or atherosclerotic plaque. Typically a guidewire is steered through the vascular system to the site of therapy. A guiding catheter can then be advanced over the guidewire and finally a balloon catheter advanced within the guiding catheter over the guidewire. A thin wall on the guide catheter will permit passage of a balloon having greater diameter, as is often necessary or desirable.
A number of different catheters have been developed that use braided or coiled reinforcing strands embedded in a plastic wall. Typical of these are the catheter structures described by Truckai in U.S. Pat. No. 5,176,660, Samson in U.S. Pat. No. 4,516,972 and Jaraczewski in U.S. Pat. No. 4,817,613. While providing acceptable torque and column strength, these arrangements tend to show low kink resistance and have undesirably thick walls.
Thus, there is a continuing need for improvements in guide catheters having reduced wall thicknesses with resulting increased lumen diameters while providing improved stiffness and torque transfer characteristics and high kink resistance.
SUMMARY OF THE INVENTION
The above noted problems are overcome by an apparatus and method of making guide catheters which, comprises the steps of providing a disposable core, braiding a flat metal wire over the core, pressing a heat bondable polymer tube over the braid and heating the assembly for sufficient time to bond the tube only to the outer surface of the braid.
A guide catheter made according to the method of this invention can have a wall thickness of about 0.005 inch, approximately half of the thickness required in conventional catheters to produce comparable physical characteristics including kink resistance and column strength.
Any suitable core material may be used. The core material should have sufficient strength to resist pressure during the heat bonding step, should not bond to the heat bonding polymer and should have low friction with the braid for easy removal. A solid fluorocarbon polymer is preferred for the core. While in some cases the core can be simply slid out of the braided tube, in some cases it is preferred that ends of the core extending beyond the braided tube be grasped and pulled apart slightly to stretch the core and reduce the cross section of the core to aid in sliding the core from the tube.
Wire may be braided in any suitable manner to form the braided tube. The braid is formed from a stiff flat wire, preferably a stiff metal having a width from about 0.005 to 0.015 inch and a thickness of from about 0.0007 to 0.0010 inch.
A heat shrink sleeve is used to perform the heat bonding. The heat shrink sleeve can be formed from any suitable material in a conventional manner. Typical heat shrink materials include fluorinated ethylene-propylene, tetrafluoroethylene and polyesters. Of these, an optimum combination of shrink pressure and shrinking temperature is found with fluorinated ethylene-propylene.
Preferably, a lubricant is coated onto the internal guide catheter surface to allow a balloon catheter or other device to be inserted into the guide catheter to be inserted and removed using less force.
It is, therefore, an object of this invention to provide an improved thinwall guide catheter with improved physical characteristics. Another object is to provide a thinwall guide catheter including a flat wire braid wherein the braid density or "pic count" is dynamically variable in response to bending, axial, or torsional loads. Another object is to make a thinwall guide catheter wherein the jacket is of variable thickness to permit dynamic expansion or contraction in response to bending, axial, or torsional loads. Another object is to make a thinwall guide catheter having improved kink resistance and column stiffness. Yet another object is to produce a thinwall guide catheter capable of bending to a smaller radius in a body lumen than conventional catheters while avoiding kinking.
BRIEF DESCRIPTION OF THE DRAWINGS
Details of the invention, and of preferred embodiments thereof, will be further understood upon reference to the drawing, wherein:
FIG. 1 is an axial section view through a thinwall guide catheter of this invention;
FIG. 2 is a transverse section view, taken on line 2--2 in FIG. 1;
FIG. 3 is a flow chart illustrating the steps in the guide catheter manufacturing method of this invention;
FIG. 4 is a perspective view of a newly completed thinwall guide catheter upon completion of manufacture and prior to removal of shaping components, with portions cut away;
FIG. 5 is a section view taken on line 5--5 in FIG. 4 with the core in an expanded state;
FIG. 6, is a portion of FIG. 4 with the core removed from the catheter; and
FIG. 7 is a view of FIG. 2 in a bent configuration such that the pic count is greater on the inside of the bending radius than on the outside of the bending radius.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, there is seen axial and transverse section views, respectively, through a thinwall guide catheter 10 made in accordance with this invention. A braided tube 12 of wires 14 is bonded within a polymer tube jacket 16. While a fairly loose braid density is shown for clarity, a tight braid density is often preferred. Jacket 16 is bonded to the outer surfaces of braided tube 12, with little material in the interstices 48 between adjacent wires 14 and essentially no polymer overlapping the inside surface of the braided tube 12.
The cross section of wires 14 may be generally rectangular, preferably with rounded edges. Alternatively, the cross section may be generally oval or elliptical, if desired. An optimum flat wire material is fully tempered 304 stainless steel. The selected wire is braided in a conventional manner over the core. Any suitable braid configuration, in particular any suitable pic count may be used. A braided tube 12 with from about 45 to about 55 cross-overs per inch is preferred. About 50 cross-overs per inch being the most optimum. Wires 14 define a "one (wire) under-one (wire) over" braiding pattern so that the wires 14 form an interlocking mesh with each other. For best results, the wires 14 have thicknesses of from about 0.0007 to 0.0010 inch and widths of from about 0.010 to 0.015 inch. Optimum results are achieved with a 0.0007 in. thick braid producing a 0.0014 in. thickness at the crossovers.
Any suitable polymer that will bond to wires 14 when heated to a suitable temperature may be used for the jacket 16. Typical such polymers include polyether block amides, polyurethanes, polyethylene, Polyamides and mixtures thereof. Of these, optimum results are obtained with the PEBAX® brand polyether block amide available from the Elf Atochem Corporation, Philadelphia, Pa. Using a jacket 16 having an average thickness of about 0.0036 inch, overall wall thicknesses of about 0.005 inch are achieved. A reduction of wall thickness from previous catheters is thus about 50%. This provides an 0.084 inch lumen in a 7 French (0.094 inch) catheter.
FIG. 3 is a flow diagram illustrating the steps in the manufacture of the improved thinwall guide catheter of this invention. FIG. 4 shows a perspective view, partly cut away, of the assembly for manufacturing the improved catheter.
A core 18 is provided, as indicated in step 20, around which the flat wire 14 can be braided as indicated in step 22. Any suitable core material that will withstand the processing conditions and can be easily removed from the product tube may be used. The material of core 18, however, should be softer than that of the jacket 16 so that the core material will expand into the interstices 48 of the braided tube 12 under the temperatures and pressures of the heat bonding process to essentially the outer surface of the braided tube 12. Typical core materials include fluorocarbon resins, such as tetrafluoroethylene and fluorinated ethylene-propylene resins. Of these, best results are obtained with tetrafluoroethylene, available under the Teflon® trademark from the E.I. duPont de Nemours & Co.
The jacket 16, in the form of a tube, is then placed over braided tube 12 on core 18, as indicated in step 24. A length of heat shrink sleeve 26, in the form of a tube, is then placed over the jacket 16, as indicated in step 28. Heat shrink sleeve 26 should be selected in material and thickness to provide the optimum pressure at an optimum temperature. Best results are obtained with fluorinated ethylene-propylene resins of the sort available from the E.I. duPont de Nemours & Co.
The resulting assembly is heated to shrink the heat shrink sleeve 26 and bond the jacket 16 to the braided tube 12, as indicated in step 30. Any suitable time, temperature and heating method may be used. Insufficient time and/or a lower than necessary temperature will result in a poor bond between jacket 16 and braided tube 12 and undesirably low stiffness values. Excessive time and/or excessively high temperatures will result in substantial encapsulation of the braided tube 12 by the jacket 16. This produces a great reduction in angular deflection to kink.
Through the proper selection of core material and processing conditions, the jacket 16 will be bonded only to the outer surface of the braided tube 12. Optimum processing conditions for a particular material for the jacket 16 can be easily obtained by making a series of catheters using different combinations of heating time and temperature. The catheters can be examined to determine the combination of time and temperature that produces catheters having the desired bonding to only the outer surface of the braided tube 12, which results in an optimum combination of column strength and kink resistance for an intended catheter end use.
Upon completion of the heating step, generally with cooling to room temperature, heat shrink sleeve 26 is stripped away as indicated by step 32 and core 18 is withdrawn as shown in step 34. Preferably, core 18 is slightly stretched to slightly reduce core cross section and ease removal. Preferably, after the core 18 is removed, a lubricant such as a silicone lubricant, is coated over the inside surface of braided tube 12 to facilitate device movement within the catheter 10.
FIG. 5 is a section through the assembly of FIG. 4, taken on line 5--5 during the heating step. This section passes through the cross-over points of the individual wires 14 of the braided tube 12. As seen, core 18 has expanded into the interstices 48 of the braided tube 12 so that the material of jacket 16 cannot penetrate into them. The "bulges" 17 in the core 18 at the interstices 48 of the braided tube 12 will retract when core 18 is cooled and can be further loosened when the ends of the core 18 are moved apart to stretch and reduce the cross-section of the core 18. Preferably, the ends of the core 18 are pulled away from each other to stretch the core 18 and reduce core diameter to allow easy withdrawal of the core 18 from the completed catheter 10.
Referring to FIG. 6, which is a section through the assembly of FIG. 4 with the core 18 of FIG. 5 removed from the catheter 10. The bulges 17 in the core 18 of FIG. 5 produce voids 19 in the jacket 16 at each interstitial location 48 between preferably four (4) adjacent cross-over points 44 of braided tube 12. The cross-over points, 44, define an outer surface 45, an inner surface 46, and an intermediate surface 47. The voids 19 in the jacket 16 are generally hemispherical in shape, producing corresponding variable thicknesses of the jacket 16 between the cross-over points 44 of the braided tube 12. The jacket 16 varies in thickness from a minimum in the center of the four respective cross-over points 44 of the braided tube 12 to a maximum at the junctions of the jacket 16 with the outer surface 45 of the respective cross-over points 44 of the braided tube 12. The effect of the voids 19 in the jacket 16 is that when the catheter 10 is subjected to bending, axial, or torsional loading, the jacket 16 is permitted to dynamically expand and contract within the interstices 48 of the braided tube 12 in response to the loads and thus resist a buckling failure.
With jacket 16 bonded only to the outer surface of braided tube 12, and the wires 14 forming a "one under-one over" braiding pattern as described above, the wires 14 are preferably bonded to the jacket 16 at every other cross-over point 44, with the cross-over points 44 therebetween being free from a bond with jacket 16. As a result of this preferred bonding geometry, when a region along the catheter is bent, the segments of individual wires 14 which are between adjacent points of bonding with the jacket 16 can move in response bending, axial, or torsional loading. For example, as seen in FIG. 7 segments of wire 14 are permitted to move toward each other on the inside of a bending radius and move apart at the outside of the bending radius, providing a resistance to kinking of the catheter 10. The effect of the wires 14 moving relative to each other in response to bending or torsion of the catheter results in a dynamically variable pic count in the catheter. This ability to vary the pic count at bends is of great importance in avoiding catheter kinking in use. Thus, the two-fold effect of a jacket 16 which is permitted to dynamically expand and contract within the interstices 48 of the braided tube with a dynamically variable pic count results in superior performance in the thinwall guide catheter.
With jacket 16 bonded only to the outer surface 45 of the cross-over points 44 of the braided tube 12, and the wires 14 forming a "one under-one over" braiding pattern as described above, the individual wires 14 are preferably bonded to the jacket 16 at every other cross-over point at the outer surfaces 45. The jacket 16, however, is neither bonded to the inner surface 46, nor bonded to the intermediate surface 47 of the cross-over points 44 at the outer surface, with the cross-over points therebetween being free from a bond with jacket 16. As a result of this preferred bonding geometry, when a region along the catheter is bent, the segments of individual wires 14 which are between adjacent points of bonding with the jacket 16 can move in response bending, axial, or torsional loading. For example, segments of wire 14 are permitted to move toward each other on the inside of a bending radius and move apart at the outside of the bending radius, providing a resistance to kinking of the catheter 10. The effect of the wires 14 moving relative to each other in response to bending or torsion of the catheter results in a dynamically variable pic count in the catheter. This ability to vary the pic count at bends is of great importance in avoiding catheter kinking in use.
The following examples provide further preferred embodiments of the catheter manufacturing method of this invention. Parts and percentages are by weight unless otherwise indicated.
EXAMPLE I
A catheter was prepared as follows. A core of tetrafluoroethylene from the duPont company, having a circular cross section and a diameter of about 0.084 inch, was provided. The core was braided in a Model K80/16-1K -72 braiding machine from the Steeger company with No. 304 flat stainless steel wire having a width of about 0.010 inch and thickness of about 0.0007 inch in a pattern producing a pic count of about 50 cross-overs per inch. A tube of polyethylene block amide polymer, available from Atochem, Inc. under the PEBAX® 7033(70D) designation was placed over the braided core. The tube has an inside diameter of about 0.087 inch and a wall thickness of about 0.004 inch. A fluorinated ethylene-propylene sleeve, available from Zeus, Inc. under the FEP heat shrink tubing designation and having an inside diameter of about 0.117 inch was slipped over the PEBAX® tube. The resulting assembly was placed in a 250° C. oven for about 5 minutes, then removed and allowed to cool to room temperature. The shrink tube was removed and the core withdrawn. The resulting tube has the outer jacket bonded to only the outside surface of the braid. The resulting catheter has approximately a 40 degree improvement in angular deflection to kink when compared to similar catheters having the braid encapsulated in the polymer and has excellent column strength. Repeated bending of the tube does not significantly lower the stiffness values.
EXAMPLES II-V
The manufacturing process of Example I is repeated four times, with the following differences:
Example II: Oven temperature 180° C., heating time 5 minutes,
Example III: Oven temperature 180° C., heating time 10 minutes,
Example IV: Oven temperature 250° C., heating time 7 minutes, and
Example V: Oven temperature 300° C., heating time 5 minutes.
The catheter produced in Example II has good kink resistance but low column strength. That made in Examples II and III have good kink resistance. In Examples IV and V, the polymer tube material penetrates into the interstices 48 of the braided tube and at least partially encapsulates the braid. Kink resistance is much lower than in Example I, although column strength is good.
EXAMPLE VII
An animal study was conducted, with a 35 kilogram canine with femoral cut down and using a 9F percutaneous sheath. Attempts to emplace a standard Sherpa® guide catheter was unsuccessful due to the relatively small canine anatomy. A guide catheter as described in Example I was successfully intubated into the left coronary artery. This guide catheter was found to be easier to turn and more responsive to movement.
While certain specific relationships, materials and other parameters have been detailed in the above description of preferred embodiments, those can be varied, where suitable, with similar results. Other applications, variations and ramifications of the present invention will occur to those skilled in the art upon reading the present disclosure. Those are intended to be included within the scope of this invention as defined in the appended claims. | An apparatus and method of making a thinwall guide catheter useful in delivery of therapeutic devices through a body vessel. The method comprises braiding a flat wire over the surface of a cylindrical core, placing a heat bondable polymer tube over the braid, surrounding the polymer tube with a heat shrink sleeve, heating the assembly to a temperature and for a time period sufficient to expand the core into braid interstices and bond the polymer tube to substantially only the outer surface of the braid and finally removing the heat shrink sleeve and core. The resulting guide catheter has approximately half the wall thickness of prior guide catheters and has excellent column stiffness and kink resistance. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C §119(e) of U.S. Provisional Patent Application No. 61/319,593, filed Mar. 31, 2010, entitled “Gift Wrap Bag,” the contents of which are incorporated herein in their entirety.
FIELD OF THE INVENTION
[0002] This invention relates to a gift bag; and in particular to a decorative gift bag which has a drawstring for easy closure and a clear pocket for insertion of a greeting card.
BACKGROUND OF THE INVENTION
[0003] Gift wrapping can be difficult when the gift is large or odd shaped. It can also prove to be difficult to get a gift wrapped in a short length of time. Gift wrapping paper is traditionally acquired in two forms: rolled around a tube approximately 3 feet in width, or folded up into a square or rectangle and enclosed in a sealed bag or protective covering. Using a roll of gift wrapping paper typically requires a large, flat area in which to unroll the appropriate amount of wrapping paper to wrap the intended gift. Wrapping a gift with wrapping paper is difficult enough when the gift is small and square or rectangle in shape, as the paper often shifts during the process, affecting the aesthetics of the wrapped package. In addition, the paper is thin and fragile and sometimes tears, requiring replacement; and the folding on the ends can present problems as the wrapper tries to fold the excess wrapping paper neatly into an aesthetically pleasing flap to tape down. Gift wrapping is further complicated when the gift is very large or odd shaped. Often times the wrapper is required to find or even purchase a box or container to put the gift into before it can be wrapped, resulting in additional expense and time spent wrapping. Sometimes the gift is purchased at the last minute and needs to be wrapped or concealed “on the fly” or in a location that does not allow for the spreading out and manipulation of awkward wrapping paper. Additionally, gift wrapping paper is usually torn and disposed of after use, which is wasteful and not cost effective.
[0004] Therefore, what is needed in the art is a gift wrap bag. The gift wrap bag should be available in various sizes which can be easily filled and closed with a ribbon or drawstring. In addition, the gift bag should contain a transparent or clear pocket located on the exterior surface to allow for the insertion of a greeting card or other means of identifying the person to receive the gift.
SUMMARY OF THE INVENTION
[0005] The present invention provides a gift wrap bag formed with a functional ribbon or drawstring member attached adjacent or in close proximity to the open mouth, with the functional ribbon or drawstring member circumscribing at least the majority of the perimeter of the mouth opening. The bag is constructed from an opaque polymeric material which may include printed designs or the like on its' outer surface. The drawstring member is attached to the bag by stitching or threading through a channel formed at the opening of the gift bag where the top edge is folded over and stitched or sealed around the perimeter of the mouth opening. Alternatively, the channel could be formed a distance from the top edge by placing a second piece of material around the perimeter or folding the top edge over and sewing or sealing two parallel seams circumscribing the bag and approximately 1 inch apart. The drawstring member can then be threaded through the channel to provide a means of closure to the gift bag. In another alternative embodiment, the drawstring member could be threaded through loops sewn or heat sealed onto the exterior surface of the bag. When the drawstring member is pulled taut, the gift bag is closed and the enclosed gift concealed. The gift bag can be purchased in a folded or rolled state in a variety of solid colors, patterns to suit any occasion or holiday, and in a variety of sizes. In addition, the gift bag preferably contains a transparent or clear pocket attached to the exterior surface. The pocket includes a panel attached on 3 sides to the exterior surface of the bag with the remaining side of the pocket open, allowing for the insertion of a greeting card or other means of identifying the person to receive the gift.
[0006] Accordingly, it is an objective of the instant invention to provide a decorative gift bag which can be easily filled and closed.
[0007] It is a further objective of the instant invention to provide a decorative gift bag in various sizes, colors and patterns that can be easily filled and closed.
[0008] It is yet another objective of the instant invention to provide a decorative gift bag that has a transparent or clear pocket in which to place a greeting card or means of identifying the person or persons to receive the gift.
[0009] It is a still further objective of the invention to provide a gift bag that can be opened without destruction of the bag to allow for bag reuse.
[0010] Other objects and advantages of this invention will become apparent from the following description taken in conjunction with any accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. Any drawings contained herein constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE FIGURES
[0011] FIG. 1 is a perspective view of a gift bag with three closed sides and an open mouth having a drawstring member incorporated into and circumscribing at least the majority of the perimeter of the mouth opening via a channel formed below the top edge of the gift bag, and a clear or transparent pocket attached to the exterior surface of the gift bag;
[0012] FIG. 2 is a side view of the gift bag wherein the drawstring member is in a relaxed or open condition and the drawstring member is threaded through a channel formed at the top edge of the gift bag, and a clear or transparent pocket attached to the exterior surface of the gift bag;
[0013] FIG. 3 is a side view of the gift bag wherein the drawstring member is in a gathered or closed condition and the drawstring member is threaded through loops sewn or heat sealed onto the exterior surface of the gift bag;
[0014] FIG. 4 is a side view of an alternative embodiment of the gift bag wherein the transparent pocket attached to the exterior surface of the bag extends across the entire side surface;
[0015] FIG. 5A is a front perspective view of an alternative embodiment of the instant invention;
[0016] FIG. 5B is a front view of the embodiment illustrated in FIG. 5A ;
[0017] FIG. 5C is a front view of the embodiment illustrated in FIG. 5A .
DETAILED DESCRIPTION OF THE INVENTION
[0018] While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred, albeit not limiting, embodiment with the understanding that the present disclosure is to be considered an exemplification of the present invention and is not intended to limit the invention to the specific embodiments illustrated.
[0019] All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
[0020] It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.
[0021] One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.
[0022] Referring to FIGS. 1-3 , the decorative gift bag 10 of the present invention is illustrated. The gift bag is formed from at least one and preferably two panels 16 and an attached functional ribbon or drawstring member 14 to form a flexible enclosure 12 having an open mouth 18 , a pocket 40 and a free edge 20 . The gift bag may be formed from a single sheet having a folded edge 22 which forms the bottom edge 24 of the enclosure and two side edges 26 that are seamed and positioned on opposite sides of the enclosure. The side and bottom edges 24 , 26 may be attached together by heat sealing, stitches, RF welding, high frequency welding, laser sealing, solvent sealing, friction sealing, hot gas sealing or the like which is well known in the art of making polymeric bags. Alternatively, the enclosure 12 may be formed from a tube of flexible material and sealed along the bottom edge 24 . The enclosure 12 is preferably made of a single layer of thin and flexible polymeric material such as plastic, biaxially-oriented polyethylene terephthalate, e.g. Mylar, or other suitable material known in the art, but could also be made of multi-layered polymeric material in any suitable thickness, size or color and may include combinations of material without departing from the scope of the invention. The drawstring member 14 is attached to the enclosure 12 adjacent the open mouth 18 and circumscribes at least the majority of the length of the fully extended perimeter 32 of the open mouth 18 . The drawstring member 14 may be made of plastic, ribbon, rope, string, or any other suitable material. The drawstring is preferably continuous, i.e. one piece and is attached to the bag in a manner to permit closure of the gift bag. In a preferred embodiment, the free edge is folded over and sewn or sealed to form a channel 28 around the perimeter of the open mouth into which the drawstring can be threaded. The drawstring of the preferred embodiment has a length exceeding the perimeter of the open mouth so that the ends 36 of the drawstring extend from the channel through at least one aperture 38 sufficiently to be grasped, pulled and tied into a knot, bow, or otherwise closed condition. In an alternative embodiment, the channel is formed onto the enclosure by stitching or sewing as at 34 . A plain straight stitch would be suitable. Stitch length is preferably on the order of 1/16 of an inch to 3/16 of an inch and preferably about ⅛ inches long. The stitching attachment can be via a thread which can be plastic or cloth. It is preferred that the drawstring be attached to the enclosure adjacent the free edge and preferably within about 1 inch or less of the free edge of the open mouth. The pocket 40 is preferably made from a transparent or clear material attached to the exterior surface of the enclosure 12 . The pocket 40 generally includes a pocket panel 42 attached on 3 sides 44 , 46 , 48 to the exterior surface of the enclosure with the remaining side 50 of the pocket open, allowing for the insertion of a greeting card 52 or other means of identifying the person to receive the gift. The edges of the pocket panel 44 , 46 , 48 may be attached to the outer surface of the enclosure by adhesive, heat sealing, stitches, RF welding, high frequency welding, laser sealing, solvent sealing, friction sealing, hot gas welding, speed tip welding, contact welding, hot plate welding, ultrasonic welding, friction welding, laser welding or the like.
[0023] Referring to FIG. 4 , an alternative embodiment of the decorative gift bag 10 is illustrated. The gift bag is formed from at least one and preferably two panels 16 and an attached functional ribbon or drawstring member 14 to form a flexible enclosure 12 having an open mouth 18 , a pocket 40 and a free edge 20 . The gift bag may be formed from a single sheet having a folded edge 22 which forms the bottom edge 24 of the enclosure and two side edges 26 that are seamed and positioned on opposite sides of the enclosure. The side and bottom edges 26 , 24 may be attached together by heat sealing, stitches, RF welding, high frequency welding, laser sealing, solvent sealing, friction sealing, hot gas sealing or the like which is well known in the art of making polymeric bags. Alternatively, the enclosure 12 may be formed from a tube of flexible material and sealed along the bottom edge 24 . The enclosure 12 is preferably made of a single layer of thin and flexible polymeric material such as plastic, biaxially-oriented polyethylene terephthalate e.g. Mylar, or other suitable material known in the art, but could also be made of multi-layered polymeric material in any suitable thickness, size or color and may include combinations of material without departing from the scope of the invention. The drawstring member 14 is attached to the enclosure 12 adjacent the open mouth 18 and circumscribes at least the majority of the length of the fully extended perimeter 32 of the open mouth 18 . The drawstring member 14 may be made of plastic, ribbon, rope, string, or any other suitable material. The drawstring is preferably continuous, i.e. one piece, and is attached to the bag in a manner to permit closure of the gift bag. In a preferred embodiment, the free edge is folded over and sewn or sealed to form a channel 28 around the perimeter of the open mouth into which the drawstring can be threaded. The drawstring of the preferred embodiment has a length exceeding the perimeter of the open mouth so that the ends 36 of the drawstring extend from the channel through at least one aperture 38 sufficiently to be grasped, pulled and tied into a knot, bow, or otherwise closed condition. In an alternative embodiment, the channel is formed onto the enclosure by stitching or sewing as at 34 . A plain straight stitch would be suitable. Stitch length is preferably on the order of 1/16 of an inch to 3/16 of an inch and preferably about ⅛ inches long. The stitching attachment can be via a thread which can be plastic or cloth. It is preferred that the drawstring be attached to the enclosure adjacent the free edge and preferably within about 1 inch or less of the free edge of the open mouth. The pocket 40 is preferably made from a transparent or clear material attached to the exterior surface of the enclosure 12 . The pocket panel 42 is constructed and arranged to extend completely across at least one panel 16 and is generally attached on 3 sides 44 , 46 , 48 to the exterior surface of the enclosure with the remaining side 50 of the pocket open, allowing for the insertion of a greeting card 52 or other means of identifying the person to receive the gift. The edges of the pocket panel 44 , 46 , 48 may be attached to the outer surface of the enclosure by adhesive, heat sealing, stitches, RF welding, high frequency welding, laser sealing, solvent sealing, friction sealing, hot gas welding, speed tip welding, contact welding, hot plate welding, ultrasonic welding, friction welding, laser welding or the like.
[0024] Referring to FIGS. 5A-C , an alternative embodiment of the decorative gift bag 10 is illustrated. The gift bag is formed from at least one and preferably two opaque panels 16 , a transparent pocket 40 and a free edge 20 forming an enclosure 12 . The gift bag 10 may be formed from a single sheet having a folded edge 22 which forms the bottom edge 24 of the enclosure and two side edges 26 that are seamed and positioned on opposite sides of the enclosure. The side and bottom edges 26 , 24 may be attached together by heat sealing, stitches, RF welding, high frequency welding, laser sealing, solvent sealing, friction sealing, hot gas sealing or the like which is well known in the art of making polymeric bags. Alternatively, the enclosure 12 may be formed from a tube of flexible material and sealed along the bottom edge 24 . The enclosure 12 is preferably made of a single layer of thin and flexible polymeric material such as plastic, biaxially-oriented polyethylene terephthalate e.g. Mylar, or other suitable material known in the art, but could also be made of multi-layered polymeric material in any suitable thickness, size or color and may include combinations of material without departing from the scope of the invention. In a most preferred embodiment, the biaxially-oriented polyethylene terephthalate includes a surface decoration suitable for a special occasion such as a birthday, etc. In a preferred embodiment, the enclosure includes a sufficient length to accept a gift or gift box in addition to enough length to allow the bag to be folded into a decorative present. Particularly, a top corner 60 of the free edge is folded over at about a 45 degree angle, and thereafter the opposite corner 62 is folded in a similar manner to form a pointed or truncated top portion as illustrated in FIG. 5B . The pointed or truncated portion can thereafter be folded over to the front side of the enclosure to be secured in place with a sticker 64 or the like. The pocket 40 is preferably made from a substantially transparent or clear material attached to the exterior surface of the enclosure 12 . The pocket panel 42 is constructed and arranged to extend completely across at least one panel 16 and is generally attached on 3 sides 44 , 46 , 48 to the exterior surface of the enclosure with the remaining open side 50 of the pocket open, allowing for the insertion of a greeting card 52 or other means of identifying the person to receive the gift. The open side of the pocket 50 may be closed after insertion of the greeting card with a sticker 64 or the like. The stickers may be supplied on a sheet 66 with the gift bag 10 in the form of a kit, and the stickers may include various occasions and holidays that further adorn the gift bag. The stickers each include an adhesive side and a non-adhesive side, whereby the adhesive side may be utilized to secure the pocket or the opening of the bag. The edges of the pocket panel 44 , 46 , 48 may be attached to the outer surface of the enclosure by adhesive, heat sealing, stitches, RF welding, high frequency welding, laser sealing, solvent sealing, friction sealing, hot gas welding, speed tip welding, contact welding, hot plate welding, ultrasonic welding, friction welding, laser welding or the like.
[0025] Thus, there has been shown and described a most preferred embodiment of a decorative gift bag with a drawstring for easy closure and a clear pocket for insertion of a greeting card. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. Many changes, modifications, variations and other uses and applications of the present construction will, however, become more apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modification, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered the invention. | The present invention provides a gift bag formed with a functional ribbon or drawstring member attached adjacent to the open mouth, with the functional ribbon or drawstring member circumscribing the perimeter of the mouth opening and extending through a channel formed at the opening of the gift bag. When the drawstring member is pulled taut, the gift bag is sealed and the enclosed gift concealed. The gift bag can be purchased in a folded or rolled state in a variety of solid colors, patterns to suit any occasion or holiday, and in a variety of sizes. In addition, the gift bag contains a transparent or clear pocket attached to the exterior surface. The remaining open side of the pocket allows for the insertion of a greeting card or other means of identifying the person to receive the gift. | 1 |
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional application serial no. 60/437,063 filed Dec. 31, 2002. The entirety of the provisional application is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention is directed to a tool box. In particular, this invention is directed to a tool box with a light.
[0004] 2. Discussion of Related Art
[0005] Typically, tool boxes are used to store tools or other items for portability. A user can transport the items to any desired location. As a result, the chosen location may or may not have adequate lighting to use the stored items. Areas under repair or construction often have inadequate lighting.
[0006] Poor lighting can pose several problems for the user. First, it may be difficult to locate items stored in the box. This is especially dangerous when the items are sharp. Second, it is difficult to properly use the items when the surrounding area is dark or not sufficiently illuminated.
[0007] For example, an automobile driver can experience a flat tire anywhere, which includes dark or poorly light roadways. On a dark roadway, it would be difficult to find the necessary tools in the box without the aid of a light. Even with a hand held flashlight, it would be difficult to use the tools while holding the flashlight. In such a situation, a conventional tool box may be rendered useless.
[0008] Thus, there is a need for a container, such as a tool box, that has a self contained light, especially a light that can be used when the tool box is open or closed.
SUMMARY OF THE INVENTION
[0009] An aspect of this invention is to provide a container with a self contained illumination device.
[0010] Another aspect of this invention is to provide a container with a light that can be used when the container is open and closed.
[0011] A further aspect of the invention is to provide a container that has an interior storage compartment suitable for storing tools and has an integral light.
[0012] An additional aspect of the invention is to provide a tool box with a light that can be positioned to illuminate surrounding areas and the interior of the tool box.
[0013] The invention relates to a tool box comprising a base having a bottom and side walls, and a cover having a top and side walls. The cover is movably mounted to the base to move between a closed position and an open position, and the base and the cover define a storage compartment therein. One of the side walls has a light permeable lens mounted therein. A light is mounted in the storage compartment and includes a power source and an illumination device. The illumination device is oriented toward the light permeable lens.
[0014] The light can be movably mounted in the cover on an articulated support such that the light is movable between a first position directed to the light permeable lens and a second position directed within the base. The box may have a pivoting handle mounted to the cover and a removable tray disposed within the box.
[0015] The invention also relates to a container comprising a bottom wall, a top wall, and an outer side wall extending between the bottom wall and the top wall to form a fully contained interior storage compartment. The outer side wall has a light transmitting opening therethrough. A light is mounted within the interior storage compartment and includes a power source and an illumination device. The illumination device is positioned at the light transmitting opening.
[0016] The container may have an articulated support coupled to the light such that the light may be moved from a first position directed at the light transmitting opening to a second position directed within the interior storage compartment.
[0017] These and other aspects of the invention will be apparent taken with the detailed description below.
DETAILED DESCRIPTION OF THE DRAWINGS
[0018] Features of the invention are shown in the drawings in which:
[0019] [0019]FIG. 1 is perspective front view of the container in accordance with a preferred embodiment of the invention in a closed position;
[0020] [0020]FIG. 2 is a front view of the container of FIG. 1;
[0021] [0021]FIG. 3 is a side view of the container of FIG. 1;
[0022] [0022]FIG. 4 is a perspective front view of the container of FIG. 1 in an open position;
[0023] [0023]FIG. 5 is an enlarged view of the light in accordance with an embodiment of the invention; and
[0024] [0024]FIG. 6 is a perspective view of a modified container in accordance with the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] This invention relates to a container and is described with particular reference to a container used as a tool box 10 . However, it should be understood that the invention can be applied to any storage container, not necessarily intended to store tools. For example, the container could be used for make-up, art supplies, gardening tools, or any desired items. Thus, the reference to a tool box used herein is intended to generically cover any portable storage container.
[0026] Referring to FIG. 1, tool box 10 includes a base 12 and a cover 14 , both preferably made of molded plastic. Of course, other materials could be used, including metal, wood, or composites.
[0027] Base 12 has a bottom wall 16 , seen in FIG. 2, and an exterior side wall 18 formed as four side walls extending from each edge of the bottom wall 16 . The side walls 18 and bottom wall 16 can have various depressed or raised portions 20 for strengthening ribs or for aesthetic reasons. The bottom wall 16 may have protrusions 22 to slightly elevate the bottom wall 16 from a support surface, thus protecting the bottom wall 16 and making it easier to lift the container 10 . The bottom wall 16 and side walls 18 define an interior storage compartment 24 , seen in FIG. 4. The front side wall 18 has a pair of hook portions 26 to latch the cover 14 , as described below.
[0028] The cover 14 has a top wall 28 and an exterior side wall 30 formed as four side walls extending from each edge of the top wall 28 . The top wall 28 and side walls 30 form an internal compartment 32 , seen in FIG. 4. Compartment 24 and compartment 32 join to form an interior storage space.
[0029] Top wall 28 has a handle 34 pivotally mounted thereon in a handle depression 36 . By this configuration, handle 34 can pivot between an upright lifting position and a folded position flush with the top surface of the container. A storage compartment 38 with a cover 40 is optionally provided in the top wall 28 of the cover 14 . The compartment cover 40 snaps to the side wall 30 to securely store items. Preferably, the compartment cover 40 is translucent so that objects stored in the compartments 38 can be seen without opening the compartment cover 40 . As seen in FIG. 1, a storage compartment 38 is provided on each side of the cover 14 . Any configuration of storage compartments 38 may be provided.
[0030] Cover 14 is coupled to base 12 with a hinge 42 , seen in FIGS. 3 and 4. Any type of hinge may be used that allows the cover 14 to open with respect to the base 12 . Latches 44 are mounted to cover 14 to selectively secure cover 14 to hooks 26 on base 12 . Again, any type of latch may be used. A locking formation 46 may be provided to mount a lock to the container 10 if desired. The locking formation 46 includes a pair of aligned slots formed on the edge of cover 14 and base 12 through which a lock may be inserted.
[0031] A generally cylindrical protrusion 48 is formed in the front side wall 30 of cover 14 that has a light permeable lens 50 . As seen in FIG. 3, preferably the protrusion 48 is flush with the outer surface of the tool box 10 . However, the size of the protrusion 48 and the extent to which it extends from the cover 14 can vary based on design choice. It is even possible to mount the lens 50 flush with the side wall 30 of cover 14 without a protrusion 48 . The lens 50 is preferably clear, transparent plastic, but could also be a colored lens if desired. Any material may be used that permits light transmission.
[0032] As seen in FIG. 4, the protrusion 48 is designed to mate with a light 52 that is retained within the cover 14 inside the box 10 . The light 52 is seen in detail in FIG. 5. Preferably, the light 52 includes a body 54 with a power source 56 , in this case batteries, contained in a compartment therein and an illumination device 58 , such as an incandescent bulb. The body 54 is preferably made of lightweight material, such as plastic. Of course, any type of power source may be used, including conventional alkaline batteries or rechargeable batteries.
[0033] The illumination device 58 may be any know device that generates light, including various known types of light bulbs. The illumination device 58 is preferably covered with a lens 60 . The compartment for the power source is covered with a pivotal compartment cover 62 that may be opened with a releasable latch 64 for easy access to the power source. By this, for example, batteries may be quickly and easily changed when necessary. An ON/OFF switch 65 is provided on the body 54 to connect the power source 56 to the illumination device 58 . The back end of the body 54 has a pivot rod 66 with a serrated gear 68 , the purpose of which is described below. The compartment cover 62 is carried on the pivot rod 66 for easy pivoting with respect to the body 54 .
[0034] Referring back to FIG. 4, the light 52 is mounted in the cover 14 on a pair of flanges 70 that retain pivot rod 66 and create an articulated support. At least one of the flanges 70 also has a serrated gear similar to gear 68 designed to engage gear 68 when the body 54 of the light 52 is rotated. By this engagement, each serration defines a discrete position at which the light 52 may be disposed. This enables the light 52 to be securely positioned at any desired angle to illuminate the interior storage compartment 24 or the environment surrounding the tool box 10 .
[0035] The internal compartment 32 of the cover 14 also has a locking formation 72 in the form of a pair of hooked fingers 74 that protrude outwardly from the cover 14 . The hooked fingers 74 are positioned to surround and engage the body 54 of the light 52 when the light 52 is pivoted upwardly into the internal compartment 32 . The hooked fingers 74 lock the light 52 in place into alignment with the lens 50 so that the illumination device 58 is directed outward through the lens 50 . In this position, the cover 14 can be closed while the light 52 is turned ON to illuminate the environment around the tool box 10 . The light 52 can also remain ON when the tool box 10 is transported.
[0036] A removable tray 76 , for storing small items for example, may be mounted in the internal compartment 24 . Tray 76 has a handle 78 and can be lifted from the box 10 to hold and transport tools or other items. Base 12 has an inner flange that supports the lip of the tray 76 . When the cover 14 is closed, tray 76 does not interfere with light 52 . It is also possible to form internal non-removable compartments in the internal compartment 24 .
[0037] It can be seen by above description that tool box 10 includes a light 52 that can used when the cover 14 is open or closed. The position of light 52 can also be selectively adjusted to shine out of the box 10 or within the box 10 at various locations in the compartment 24 . This allows a user to use the box 10 to illuminate an object that the user is working on, such as an automobile tire, and to illuminate the interior of the box 10 to locate a tool when insufficient external light is available, such as at a roadside.
[0038] [0038]FIG. 6 shows a modified storage container 80 having a larger base 82 and a cover 84 with a light opening 86 . Cover 84 has partitioned compartments 88 on each side that have compartment covers. As can be appreciated from the various compartment arrangements, any shape or number of compartments can be provided if desired. In this case, base 82 is significantly larger and may constitute a workbench type of storage container. A light within the container 80 works in the same manner as box 10 .
[0039] Various modifications and changes can be made to the invention and remain within the scope of the invention. It is possible to mount the light in the base, rather than the cover. It is also possible to modify the position of the light transmitting opening to be in the base or in another position on the cover.
[0040] It is also contemplated that the light can be removable, in which case the body of the light can be formed as a sleeve that the light is removably retained in so that a user can remove the light and use it as a hand held flashlight. Alternatively, the body of the light can be released from the hinge, such as by a snap fit, for hand held use. These and other modifications are within the scope of the invention as defined by the appended claims. | A container, such as a tool box, has an interior storage compartment and a cover with a light opening therein. A light is mounted within the compartment and is selectively positionable to shine through the light opening or to illuminate the interior of the storage compartment. Preferably, the light is mounted on an articulated hinge allowing movement between a plurality of discrete positions and locks in place in a stored position. The light may be battery operated and may be removable if desired. | 5 |
SUMMARY OF THE INVENTION
This invention deals generally with power plants and more specifically with a coal burning plant which drives a closed cycle gas turbine by means of heat transfer with an array of heat pipes.
While fluidized bed combustors have been used in the prior art as shown in U.S. Pat. No. 3,871,172 by Villiers-Fisher, et al., and while closed cycle engine generators are known within the power generating field, efficient heat transfer between these two systems has remained a challenge. Heat pipes, which have been used to advantage in many other heat transfer applications have not been anticipated for use in the fluidized bed application because of the high rate of deterioration and damage from immersion of a heat pipe within the fluidized bed.
The fluidized bed using limestone or dolomite is the leading solution to the need for the combustion of sulphur-bearing coals without the emission from the stack of gaseous sulphur compounds which are ecologically damaging. Instead, the sulphur contained in the coal reacts chemically with the limestone to form solid compounds which are readily removed with the ash residue of combustion.
For optimum capture of sulphur from coal, a limestone fluidized bed must be operated within a relatively narrow temperature range, roughly 1500°-1700° F. One of the major problems in the use of limestone fluidized beds is the control of bed temperature in spite of the widely varying power demands which characterize practical commercial power generating systems.
It is a characteristic of closed cycle gas turbines, as opposed to vapor turbines or open cycle gas turbines, that the variation in power output is accomplished by varying the pressure of the working gas rather than its temperature. The effect is to permit the heat source which heats the gas to operate at a relatively constant temperature regardless of variations in power demand. The present state of the art in turbine technology permits high efficiency operation in the 1400°-1700° F. temperature range.
This correspondence between the optimum operating characteristics of limestone fluidized beds and closed cycle gas turbines has been widely observed and is the subject of active development work. The problem lies in the abrasive character of the coal combustion gases. If, as they leave the fluidized bed, these hot gases are ducted directly through the turbine, they are found to carry along appreciable quantities of solid particles of fly ash from the coal and limestone. These particles rapidly erode the turbine blade materials, leading to catastrophically reduced operating life and reliability.
A conventional heat exchanger can be placed between the combustion gas and the turbine working gas to allow the heat to pass to the turbine but exclude the abrasive particles, but two disadvantages are seen to exist for this solution to the problem. First, the heat exchanger is subject to erosion and clogging by the abrasive particles. Furthermore, in most commercial heat exchangers, the puncturing of the exchanger membrane in even one place will permit the abrasive particles to leak into the turbine or permit the turbine working gas to escape. Either represents a complete system failure. A heat exchanger is needed which minimizes the effects of abrasion and clogging. Second, the insertion of the heat exchanger in the thermal path causes a temperature loss and results in decreased turbine power output. A high efficiency, low temperature loss, heat exchanger is required.
The present invention makes use of a high efficiency, high reliability heat exchanger using heat pipe principles. Heat pipes in which sodium serves as the thermodynamic working fluid are well suited for operation at 1400°-1800° F. and sodium heat pipes are capable of accepting heat at the relatively high power densities available within a fluidized bed. Sodium heat pipes are also capable of transferring the desired power of several kilowatts needed for a practical industrial or commercial power plant. Heat pipes have an intrinsically high thermal conductance and will therefore carry the power with a very small temperature loss. The result is a high efficiency heat exchanger which, in turn, permits the delivery of high temperature gas to the turbine, yielding high system efficiency.
The array of simple, cylindrical heat pipes permits ready circulation of the particles of the fluidized bed, preventing clogging and establishing a uniform temperature within the bed.
Each heat pipe is a self-contained, sealed heat transfer element independent of all others. The power plant employs several thousand such heat pipe elements in the heat exchanger. Therefore, the failure of an individual heat pipe will not cause a system failure, as would be the case with a conventional heat exchanger. The effect of the loss of a single element will be to increase the thermal resistance of the heat exchanger very slightly. For instance, if one thousand heat pipes are used, a single loss has an effect of only 0.1 percent, a negligible loss of efficiency. Failed heat pipes, if any, can be readily replaced during normal system shut-down periods when other regular maintenance is performed.
Moreover, the failure of a heat pipe will not permit working gas to escape from the closed cycle engine loop, nor fly ash to enter the engine inlet, because for this to happen it is necessary for both ends of the same heat pipe to be breached, a most unlikely occurance.
The heat pipes used in the system are, however, specially constructed to enhance their reliability in the severe conditions encountered within the fluidized bed. The heat pipes are protected from erosion, corrosion and gas permeation by constructing the heat pipe outer shells of steel upon which a thin layer of the oxides of aluminum, silicon or titanium of approximately one micron is produced.
This oxide layer is produced according to the teachings of U.S. Pat. No. 4,082,575 or U.S. Pat. application Ser. No. 169,659 by heating a steel with, for instance, an aluminum content of 1/2 to 5% to a temperature of 500° to 1000° C. for 1-10 hours. When heated in an air or oxygen atmosphere the oxide surface coating is continuous and water resistant, and when heated in a reducing atmosphere of hydrogen the oxide coating is also impermeable to hydrogen. The resulting heat pipe is therefore protected from the permeation by hydrogen and corrosion by moisture generally existing within the fluidized bed.
This thin oxide layer is itself protected from erosion due to the rapid motion of the fluidized bed particles by plasma spraying a second ceramic layer such as aluminum oxide over only the portion of the heat pipe immersed in the fluidized bed. This second protective ceramic layer is from 0.010 to 0.125 inch thick on the outside surface of the heat pipe casings.
The system of the invention will therefore provide high efficiency conversion of the combustion energy of coal to more useful forms of energy. It will perform this service without excessive atmospheric pollution, reliably and economically for an extended operating life in contrast to alternative systems made according to prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified block diagram of the power plant of the invention.
FIG. 2 is a simplified cross section side view of the preferred embodiment of the combustion chamber and heat transfer section of the invention.
FIG. 3 is a perspective view of a specially constructed heat pipe of the invention.
FIG. 4 is a cross sectional view of an alternate embodiment of the combustion chamber and heat transfer section of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The simplified block diagram of power plant 10 of the invention is shown in FIG. 1 where heat from combustion gases 12, resulting from burning coal in combustor 14 is used to heat the gas entering turbine 16 by the operation of heat exchanger 18. The hot gas powers gas turbine 16 before being returned by line 20 for reheating in heat exchanger 18. Gas turbine 16 mechanically drives generator 22 to produce distributable power in the form of electricity.
The combustion process taking place in combustor 14 uses coal and air fed to it to produce heat, combustion gases and ash.
The combustion gases 12 are passed through heat exchanger 18, and, after transferring a major portion of their heat to the turbine gas, pass into precipitator 24 which removes the remaining solid particles. The remaining heat energy in the exhaust gases is removed in boiler 26 and converted into vapor for auxiliary use, such as building heat, before the remaining gases are exhausted from the system. Boiler 26 is also usable to generate vapor for utilization in a low temperature vapor cycle turbine to produce additional mechanical energy for production of electricity.
FIG. 2 depicts the preferred embodiment of combustor 30 and heat exchanger 18 of the power plant which serve the vital functions of producing usable heat from coal, removing the sulphur contamination and transferring the heat to the turbine system.
All the functions are accomplished within vessel 32 within which fluidized bed 34 is burned. Fluidized bed 34 is continuously fed a suitable mixture of finely ground coal by means of feed pipe 36, and limestone, generally in place, can be replenished through pipe 37. Compressed air is supplied through pipe 38, while fluidized bed 34 is held in position by means of plate 35 with holes 33 through which the air passes. Fluidized bed 34 can be operated between 1500° and 1700° F. at which temperatures the sulphur in the coal combines with the lime to form heavy solid ash which falls down out of vessel 32 through discharge pipe 40.
Combustion gases exit vessel 32 above fluidized bed 34 through pipe 42, which, as shown in FIG. 1, delivers them to a precipitator for further cleansing.
The heat generated by the combustion of fluidized bed 34 is transferred to the turbine gas by means of vertical heat pipes 44 which pass through gas tight wall 46 which forms separate chamber 48 for turbine gas. Cold gas enters chamber 48 through duct 50, is heated by fins 52 attached to heat pipes 44 and 45, and exits to gas turbine 16 (FIG. 1) from duct 54.
By means of their well known heat transfer abilities, heat pipes 44 and 45 transfer heat from fluidized bed 34 to the turbine gas with very little change in temperature, thus permitting both the turbine and the fluidized bed to operate within their optimum temperatures, both in the same range of 1400° to 1700° F.
Gas-tight flanges 56 are used at the points at which heat pipes 44 and 45 penetrate wall 46 in order to both assure no leakage between the combustion gas system and the turbine system and to facilitate removal of the heat pipes for maintenance or replacement.
The preferred embodiment includes a very large quantity of heat pipes 44 and 45, which are not all shown for clarity of the drawing. The use of over one thousand such heat pipes is an assurance of reliable uninterrupted operation of the power plant since the failure of any one heat pipe by, for instance, puncture of the portion in the fluidized bed, is non-catastrophic and affects the power output by only a fraction of one percent. Since such failures are essentially not significant, the system can be operated without shutdown until normal maintenance shutdown occurs, at which time replacement can be made.
Heat pipe 45, shown in FIG. 2, is constructed similarly to heat pipe 44 except, while heat pipe 45 is depicted as a straight cylinder with one set of fins 52, heat pipe 45 is constructed with a branch section and a second set of fins 52. Such additional heat pipe condensing sections permit the balancing of the heat transfer characteristics within the input and output systems of heat pipe 45. Use of additional branches of virtually any number permits optimizing the heat transfer both at the input within fluidized bed 34 and the output at fins 52.
As shown in FIG. 3, heat pipe 44 is of a novel construction to minimize pipe failures despite the extreme environment of the fluidized bed combustion chamber.
Heat pipe 44 of the preferred embodiment utilizes sodium as the working fluid to operate in the desired temperature range of 1500° to 1700° F., and is oriented vertically to permit wickless construction for economy. Heat pipe 44 is constructed of steel and has an impervious continuous, approximately one micron thick, external layer containing oxides of aluminum, titanium or silicon. The oxide layer prevents permeation of the heat pipe by hydrogen gas and corrosion by water vapor present in the combustion chamber. This thin oxide coating can be produced by known processes disclosed in the patent and patent application noted above and can be either a single pure oxide or contain all three oxides named.
Heat pipe 44 and the thin oxide coating are further protected from erosion by second ceramic coating 58 of between 0.010 and 0.125 inch thickness which is plasma sprayed onto that portion of heat pipe 44 to be immersed in the fluidized bed. This second ceramic coating is composed of oxides of aluminum, silicon, titanium, magnesium and calcium either in the pure form of a single oxide or with some mixture of oxides. Since its essential function is abrasion resistance, and the function of a permeation barrier is fulfilled by the thin continuous layer underneath, this second surface's purity is not critical.
Gas-tight flange 56 is attached to heat pipe 44 at junction 60 by conventional bonding methods such as welding and has bolt holes 62 for conventional leak-tight attachment to wall 46 (FIG. 2). The bolt-on construction makes rapid replacement of individual heat pipes possible during regular maintenance periods of the power plant.
The portion of heat pipe 44 on the opposite side of flange 56 has attached to it heat transfer fins 52 to enhance heat exchange to the turbine gas. These fins are attached by conventional methods, familiar to those skilled in the art of heat transfer, but it is of some interest to note that the thin oxide coating of approximately one micron has no significant effect on the heat transfer between the heat pipe and the fins.
FIG. 4 depicts an alternate embodiment 68 of the combustion chamber and heat transfer section in which heat pipes 70 themselves contain the system of heat transfer to the turbine gas, but in which the lower portion of combustion chamber 72 functions in the same manner as vessel 32 of FIG. 2.
Fluidized bed 74 is fed coal and limestone and combustion takes place within combustion chamber 72 creating heat in the same manner as before. However, to eliminate the requirement for a very large, high pressure chamber 48 (FIG. 2), high pressure gas for the turbine is fed into each individual heat pipe 70 by input piping 76. The gas, after heating as it passes through heat pipe 70, exits through output piping 78. Input piping 76 of many individual heat pipes 70 is fed from input manifold 80, and output piping 78 of many heat pipes is combined into output manifold 82. Since, as noted above, several thousand heat pipes are actually used, the total gas flow in manifolds 80 and 82 is sufficient for turbine drive even though the flow through each heat pipe is appropriate for the smaller size of input piping 76 and output piping 78. Moreover, the smaller size of the piping through heat pipes 70 make attaining high pressure integrity far simpler than with the large pressure chamber of FIG. 2.
It is to be understood that the form of this invention as shown is merely a preferred embodiment. Various changes may be made in the function and arrangement of parts; equivalent means may be substituted for those illustrated and described; and certain features may be used independently from others without departing from the spirit and scope of the invention as defined in the following claims.
For instance, other methods of attachment of the heat pipes to the wall of the chamber can be used and the heat pipes may contain wicks or portions of wicks or be, as described, wickless. Also, potassium, lithium and certain molten salts could be used as heat pipe fluids and the mechanical energy of the turbine could be used for other mechanical purposes instead of generating electricity. Moreover, the heat exchanger could be oriented so that the heat pipes are horizontal or at some angle to the vertical without loss of the benefits of the invention, and ash can be removed by methods other than gravity fall-out, such as a conveyor system or batch unloading. | A coal burning power plant which produces electricity at high efficiency and with very low levels of atmospheric contamination. A fluidized bed of limestone and coal is used to burn the coal with little air pollution, and a large quantity of specially constructed heat pipes transfer the heat to a closed cycle gas turbine with very low temperature loss. The preferred embodiments of the heat pipes are constructed with steel casing, have a thin aluminum oxide layer on their surfaces to prevent hydrogen permeation into the casing and have a plasma sprayed coating of ceramic on the portion within the fluidized bed to prevent erosion of the heat pipe casing by the solid particles within the bed. | 5 |
This is a continuation of application Ser. No. 906,650, filed Sept. 11, 1986, which is a continuation of Ser. No. 554,839, filed Nov. 23, 1983 both now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a reproducing apparatus and more particularly to an apparatus for controlling the position of a transducer relative to recording tracks on a recording medium, i.e. for tracking control over the transducer.
2. Description of the Prior Art
Recording tracks which are formed, for example, concentrically on a recording medium, such as a magnetic disc, have some positional error deviating about several ten μm from a reference position due to the error of a stepwise feeding action performed on a recording head during a recording. Therefore, where record reproduction is carried out with a reproducing apparatus that differs from the apparatus used for recording the record or where the recording medium has been deformed by changes in temperature, etc., it is difficult to accurately carry out tracking control solely by means of the stepwise feeding mechanism including a suitable driving source, such as a stepping motor. To overcome this difficulty, there has been proposed an arrangement in which automatic tracking control is accomplished with a transducer, such as a magnetic head, carried by an electric-to-mechanical converting element. This element is driven with a control signal based on a reproduction output. However, in moving a reproducing head at a high speed for continuous reproducing, etc., the tracking control arrangement of the prior art has presented a problem with respect to the responsibility of the electric-to-mechanical converting element. Another shortcoming of the prior art arrangement is that the controlling direction of the tracking control is hardly discernible when the control is accomplished by a dither method.
It is a principal object of the present invention to provide a reproducing apparatus which is capable of eliminating the above shortcomings of the prior art and particularly those of the tracking control arrangement hitherto employed.
It is another object of the invention to provide a tracking control arrangement which is compatible between different apparatuses and is provided with means for permitting adequate control even in an operation mode in which a transducer must continuously gain access to a plurality of recording tracks, one after another, on a recording medium, as during a continuous reproducing mode or during a search mode.
It is a further object of the invention to provide means for carrying out appropriate control even in an operation mode wherein the transducer, by the above arrangement, gains access to the above-plurality of recording tracks, one after another.
SUMMARY OF THE INVENTION
A reproducing apparatus for reproducing recorded signals from a signal bearing medium having a plurality of tracks, each recorded with a signal in which the apparatus includes transducer means for reproducing a signal from a selected track of the signal bearing medium, moving means for relatively moving the transducer means and the bearing medium so as to position the transducer means and the signal bearing medium so as to position the transducer means relative to the selected track of the medium, and adjusting means for adjusting the position of the transducer means relative to the selected track. The apparatus also includes control signal producing means for producing, on the basis of a reproduced signal obtained through the transducer means, a control signal for controlling the adjusting means to align the transducer means with the selected track. Also included are memory means for memorizing the control signal produced from the control signal producing means and signal providing means for providing the adjusting means with the control signal memorized in the memory means.
To achieve the second object, a preferred embodiment representing an aspect of the invention includes a moving mechanism which moves a transducer relative to recording tracks on a recording medium, tracking control means which controls tracking of the transducer according to a signal reproduced by the transducer, and memory means which memorizes information on the transducer tracking control.
To achieve the third object, a preferred embodiment representing an aspect of the invention includes a shifting mechanism which shifts a transducer relative to recording tracks on a recording medium; tracking control means which controls tracking of the transducer according to a signal reproduced by the transducer; memory means which memorizes information on the transducer tracking control; and adjusting means for adjusting the position of the transducer depending on the control information memorized in the memory means in an operation mode in which the transducer is allowed to gain access to a plurality of recording tracks, one after another, recorded on the recording medium.
In the foregoing description, the term "transducer" means a signal transducer, such as a magnetic head, an optical head, an electrostatic capacity type head or the like that reproduces signals recorded on the recording medium. The term "recording medium" as used, for the purpose of this invention, is any of the recording medium usable for the above signal transducer means.
These and further objects and features of the invention will become apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a reproducing apparatus and particularly the arrangement of the tracking control part thereof as a preferred embodiment of the present invention.
FIG. 2 is a circuit diagram showing the details of the tracking control circuit shown in FIG. 1.
FIG. 3 is a circuit diagram of a system control circuit and an operation part included in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, which shows a reproducing apparatus as an embodiment of the present invention, the apparatus includes a magnetic disc 1 as a recording medium which has a center core 1a at the center thereof; a disc motor 2 which drives the magnetic disc 1 and which has a rotating spindle 2a having the center core 1a of the disc magnetic 1 attached thereto; a magnetic head 3 as a transducer; and an electric-to-mechanical converter element 4 which is composed of, for example, a piezoelectric bi-morph element. The electric-to-mechanical converter element 4 carries the magnetic head 3 at its fore end and is deflectable to displace the head 3 relative to the magnetic disc 1 in the radial direction thereof, that is in a direction crossing the recording tracks. The electric-to-mechanical converter element 4 is attached to a head carriage 5 at its tail end. The head carriage 5 is provided with an engaging part 5a which has a female screw part. This female screw part of the engaging part 5a is engaged with a screw 6, which is provided on a shaft 7a of a step motor 7. In addition, the head carriage 5 also engages with a guide member, which is not shown, at a suitable part thereof. The head carriage 5 is thus movable in the radial directions of the magnetic disc 1, i.e. a direction crossing the recording tracks as the shaft 7a of the step motor 7 rotates. The electric-to-mechanical converter element 4, which acts as an actuator on the magnetic head 3, may be replaced with a moving coil. Meanwhile, the step motor 7, which serves as stepwise feeding means, may be replaced with some other moving mechanism consisting of a drive source, such as a plunger or the like, and a cam mechanism driven by the drive source.
The apparatus further includes a tracking control circuit 8 which detects a signal reproduced by the magnetic head 3 and produces a correction signal for correcting the track deviation of the head 3 relative to a selected track. The details of the tracking control circuit 8 will be described later herein with reference to FIG. 2. A drive circuit 10 drives the electric-to-mechanical converter element 4. The drive circuit 10 is connected via a terminal "a" of a switch circuit 9 to the output terminal of the tracking control circuit 8 and via another terminal "b" of the switch circuit 9 to the output terminal of a memory circuit 11. The memory circuit 11 is connected to the output terminal of the tracking control circuit 8 via a switch circuit 15. A system control circuit 12 controls the step motor 7, the switch circuit 9 and a timer circuit 14, which will be described later herein. The system control circuit 12 is in combination with an operation part 13. The timer circuit 14 controls the switch circuit 15 by the output thereof.
The following description of the operation of the apparatus described above deals mainly with the features of the present invention: The feeding screw 6 has the lead thereof such that an integral multiple of the number of rotating steps of the step motor 7 corresponds to the amount of shift of the magnetic head 3 on the magnetic disc 1 in the radial direction of the magnetic disc 1 to an extent corresponding to one track pitch. However, for the sake of simplification, let us assume that the one rotating step of the step motor 7 corresponds to a head feeding extent corresponding to one track pitch. The reproduction output of the magnetic head 3 is supplied to the tracking control circuit 8. The tracking control circuit 8 then produces a correction signal for correcting the track deviation of the magnetic head 3 relative to a selected track. The correction signal is fed back via the drive circuit 10 to the electric-to-mechanical converter element 4 to effect the tracking control over the magnetic head 3.
Meanwhile, recording tracks, which are concentrically formed on the magnetic disc 1, are deviating from their reference positions approximately ten μm due to a feeding error of a recording head or the like, which was made at the time. Therefore, where the record of these tracks is to be reproduced by a reproducing apparatus other than an apparatus used for recording or where the magnetic disc 1 is expansively or contractively deformed by changes in temperature, etc., it is hardly possible to accurately accomplish tracking control by merely operating the stepwise feeding mechanism of the step motor 7. Therefore, as has been mentioned in the foregoing, there has been proposed an automatic tracking control means. However, in the event that the magnetic head 3 is to be moved quickly by allowing the step motor 7 to rotate at a high speed, as in the case of continuous reproduction, continuous reproduction of different still pictures or motion picture reproduction, the electric-to-mechanical converter element 4 presents a problem in responsiveness. Besides, when using the automatic tracking control in accordance with a dither method, the controlling direction of the magnetic head 3 is hardly discernible when the magnetic head 3 is dither controlled while straddling two tracks.
In the embodiment shown in FIG. 1, therefore, the correction signal produced from the automatic tracking control circuit 8 is memorized at the memory circuit 11 when one track is reproduced for a time greater than a predetermined period. Then, positioning control over the magnetic head 3 is performed based on the memorized correction signal until another track is reproduced for a time greater than the predetermined period.
More specifically, in a single track reproducing mode, when the operator designates a desired track number at the operation part 13, the step motor 7 rotates either forward or backward. Thereby the head carriage 5 operates until the magnetic head 3 reaches the designated track and the apparatus operates in the single track reproducing mode. In the single track reproducing mode, the timer circuit 14 operates under the control of the system control circuit 12. After the lapse of a predetermined time period, say, one second or thereabout, required for completion of an automatic tracking control operation, the timer circuit 14 produces an output. The output of the timer circuit 14 cancels the switch circuit 15, closing for a predetermined time period. Then, a correction signal produced at that time from the tracking control circuit 8 is memorized in the memory circuit 11.
Next, when the operator sets the apparatus in a mode for allowing the magnetic head 3 to gain access to a plurality of tracks one after another, such as in a continuous reproduction mode or a search mode, the system control circuit 12 causes the switch circuit 9 to connect the terminal "b" thereof. This holds the magnetic head 3 under the control of the correction signal memorized in the memory circuit 11 via the drive circuit 10, and the magnetic head 3 is moved to the tracks by the step motor 7. Then, when the operator again sets the apparatus back to the single track reproducing mode, the switch circuit 9 connects the terminal "a" and automatic tracking control is performed according to the reproduction output of the magnetic head 3. Then, after the lapse of the above predetermined time period, a new correction signal is memorized in the memory circuit 11.
An example of an arrangement of the above tracking control circuit 8 is as shown in FIG. 2. Referring to FIG. 2, the reproduction output of the magnetic head 3 shown in FIG. 1 is amplified at a reproduction amplifier 16. After that, the amplified reproduction output is supplied to an envelope detection circuit 17 having the envelope thereof detected there. In this specific example, the signal recorded on the magnetic disc 1 is a frequency modulated signal such as a video signal. The output of the envelope detection circuit 17 is sampled and held by a first sample-and-hold circuit 18 in accordance with the timing of timing pulses "b" from a timing pulse generation circuit 21 as shown in the drawing. The output is further sampled and held by a second sample-and-hold circuit 19 according to the timing of timing pulses "a" produced from the timing pulse generation circuit 21. The outputs of the first and second sample-and-hold circuits 18,19 are applied to a comparison circuit 20 for size comparison. Assuming that the input from the first sample-and-hold circuit 18 is A and the input from the second sample-and-hold circuit 19 is B, the output level "A>B" of the comparison circuit 20 becomes high when A is larger than B and the level of another output "A=B" of the circuit 20 becomes high when the two inputs are equal. In the actual arrangement, the comparison circuit 20 includes, for example, a differential amplifier which obtains "A-B"; two voltage comparators which compare respectively the output "A-B" of the differential amplifier with small reference voltages +ΔV and -ΔV, which are as shown in broken lines in FIG. 2; an NOR logic gate which receives the outputs of the two comparators; etc. The comparison circuit 20 makes the output level "A>B" high when A-B>+ΔV and the output level "A=B" high when -ΔV<A-B<+ΔV.
The output "A=B" of the comparison circuit 20 is inverted by an inverter 22 and is then applied to one of the input terminals of an AND gate 23. Meanwhile, timing pulses "c" produced from the timing pulse generation circuit 21 are applied to the other input terminal of the AND gate 23. The AND gate 23 allows the timing pulses "c" to pass therethrough only when the output level of the inverter 22 is high, that is, only when the level of the output "A=B" of the comparison circuit 20 is low. The timing pulses "c" thus produced from the AND gate 23 are supplied to the clock input terminal of an up-down counter 24 (hereinafter called U/D counter) which then counts the pulses "c". Meanwhile, the output "A>B" of the comparison circuit 20 is applied as a count mode control signal to the mode input terminal of the U/D counter 24. The U/D counter 24 assumes an up count mode when the level of the output "A>B" is high and a down count mode when the level of the output "A>B" is low. The digital output of the U/D counter 24 is supplied to a digital-to-analog converter 25 (hereinafter called D/A converter). The D/A converter 25 converts the digital output into a corresponding analog voltage. The analog voltage output thus produced from the D/A converter 25 is supplied to the switch circuits 9 and 15, which are shown in FIG. 1.
Assuming that one field portion or one frame portion of a video signal according to the NTSC system is recorded on one circular track of the magnetic disc 1, the magnetic disc 1 must be rotated at 3,600 rpm or 1,800 rpm during reproduction. As for the timing pulse generation circuit 21, the timing pulses "a", "b" and "c" are all produced at 60 Hz or 30 Hz at, as shown in FIG. 2, during reproduction. In other words, the timing pulses "b" are produced slightly later than the timing pulses "a" and the timing pulses "c" slightly later than the timing pulses "b". With such an arrangement, the first sample-and-hold circuit 18 always samples and holds the output of the envelope detection circuit 17 produced for the same point on each of the recording tracks of the magnetic disc 1. The second sample-and-hold circuit 18 samples and holds a value held by the first circuit 18 immediately before renewal thereof. As a result, the high level of the output "A>B" of the comparison circuit 20, which compares the outputs A and B of the first and second sample-and-hold circuits 18 and 19, indicates that the magnetic head 3 is moved adjust its position to the recording track of the magnetic disc 1. The high level of the output "A=B" indicates that the head 3 is on-track, i.e. adjusted. If both the levels of the outputs "A>B" and the "A=B" are low, it indicates that the magnetic head 3 is being displaced, moving away from the recording track. Accordingly, the U/D counter 24 counts upward as long as the output "A>B" remains at a high level, counts downward as long as both the levels of the outputs "A>B" and "A=B" remain low and stops counting when the level of the output "A=B" becomes high. With the U/D counter 24 controlled in this manner, the U/D counter 24 gives digital data required for controlling the electric-to-mechanical converter element 4 for adjusting the magnetic head 3 to the recording track. The output of the U/D counter 24 is converted into the corresponding analog voltage at the D/A converter 25. The analog voltage thus obtained is supplied to a subsequent circuit, shown in FIG. 1 as the tracking correction control signal.
The drive circuit 10, which is shown in FIG. 1 is, drives and deflects the electric-to-mechanical converter element 4 to an extent corresponding to the value of the analog voltage produced from the above-D/A converter 25. The arrangement of this circuit is well known as, for example, a bi-morph element driving circuit and thus requires no further description herein. The memory circuit 11 memorizes the analog voltage output of the D/A converter 25 supplied thereto via the switch circuit 15. In this specific embodiment, the memory circuit 11 is formed as an analog voltage memory circuit including a capacitor, etc. in a well known manner.
FIG. 3 shows the details of the arrangement of the above system control circuit 12 and the operation part 13.
The operation part 13 includes a switch 26 for setting the single track reproducing mode; a switch 27 for setting the continuous reproducing mode; and a ten-key board 28 for setting an address of a desired track to be reproduced in the single track reproducing mode and an address of a desired starting track with which reproduction is to be started in the continuous reproducing mode.
The system control circuit 12 includes an RS flip-flop 29 which memorizes the setting mode of the apparatus and is set in response to the operation of the reproducing mode switch 27. The RS flip-flop 29 is reset by a power-up-clear signal PUC and also by the operation signal of the single track reproducing mode switch 26 supplied via an OR gate 30. Accordingly, the high level of the output Q of the RS flip-flop 29 or the low level of the output Q thereof indicates the continuous reproducing mode while the high level of the output Q or the low level of the output Q indicates the single track reproducing mode. The output Q of the RS flip-flop 29 is supplied to the switch circuit 9 of FIG. 1. In this specific embodiment, the switch circuit 9 is connected to the side of a terminal "a" in response to the low level of the output Q of the RS flip-flop 29 representing the single track reproducing mode and to the terminal "b" in response to the high level of the output Q representing the continuous reproducing mode. The switch circuit 9 is operated in this manner by known electronic means.
The datum on the track designated by the ten-key board 28 is memorized by a memory circuit 31 which is composed of a register, etc. The output of the memory circuit 31 is supplied to the preset input terminal (PR-IN) of a presettable counter 32 and also to the first input terminal (IN-1) of a data selector 34. With the apparatus set in the continuous reproducing mode, a datum produced from the memory circuit 31 at that time is preset in the presettable counter 32 in response to the high level of the output Q of the RS flip-flop 29. Then the counter 32 counts track change pulses produced from a pulse generation circuit 33. The output of the counter 32 is supplied to the second input terminal (IN-2) of the data selector 34. The data selector 34 receives the output Q of the RS flip-flop 29 as a control signal. When the output Q is at a low level, i.e. in the single track reproducing mode, the data selector 34 selects the output datum of the memory circuit 31 received at the first input terminal IN-1. When the level of the output Q is high, i.e. in the continuous reproducing mode, the data selector 34 selects the output datum of the counter 32 received at the second input terminal IN-2. The output of the data selector 34 is supplied to the A input terminal (IN-A) of a digital magnitude comparator 35. Meanwhile, the output of an up-down counter 36 (hereinafter called the U/D counter) which memorizes an address of a track confronting the magnetic head 3 is supplied to the B input terminal (IN-B) of the comparator 35. The comparator 35 determines which of the two inputs A and B is larger or smaller and, as a result, makes the level of one of its outputs "A>B", "A=B" and "A<B" high. These three outputs of the comparator 35 are supplied to a step step motor drive circuit 37. The motor drive circuit 37 drives the step motor 7, shown in FIG. 1 on the basis of the three outputs and the motor driving pulses produced from a pulse generation circuit 38. More specifically, when the level of the output "A>B" of the comparator 35 is high, for example, the drive circuit 37 causes the motor 7 to rotate forward to move the magnetic head 3 in the predetermined direction (for example, toward the center of the disc 1). When the level of the output "A<B" is high, the drive circuit 37 rotates the motor 7 backward moving the magnetic head 3 in the reverse direction (for example, toward the periphery of the disc 1). If the level of the output "A=B" is high, the drive circuit 37 cuts off the supply of the driving pulses stopping the motor 7. Furthermore, the high level of the output "A>B" of the comparator 35 sets the counting mode of the U/D counter 36 to an up-count mode while the low level of the output "A>B" sets it to a down-count mode. The U/D counter 36 counts the driving pulses applied from the step motor drive circuit 37 to the step motor 7 and is cleared by the power-up clear signal PUC.
The outputs "A>B" and "A<B" of the comparator 35 are supplied to an OR gate 39. Therefore, when the address of the track confronting the magnetic head 3 does not coincide with the track address represented by the datum produced from the data selector 34, i.e. the designated track, the output level of the OR gate 39 becomes high. The output of the OR gate 39 is supplied to an AND gate 40 together with the output Q of the RS flip-flop 29. Therefore, the output level of the AND gate 40 becomes high when the address of the track confronting the magnetic head 3 does not coincide with the designated track. The output of the AND gate 40 is supplied to an OR gate 41 together with the output Q of the RS flip-flop 29. The output of the OR gate 41 is then supplied to the timer circuit 14 of FIG. 1 as a reset signal. The timer circuit 14 is thus reset by the high level output of the OR gate 41 and counts only when the output level of the OR gate 41 is low.
In the above embodiment, the operation in the single track reproducing mode is as follows: The address of a desired reproducing track is set into the memory circuit 31 via the ten-key board 28. Then, when the single track reproducing mode switch 26 is operated, the RS flip-flop 29 is reset. The output level Q of the RS flip-flop 29 becomes low and the output Q becomes high. The low level of the output Q connects the switch circuit 9 to the terminal "a". The output of the tracking control circuit 8 is thus supplied to the drive circuit 10. The data selector 34 selects the output of the memory circuit 31. Then, the motor drive circuit 37 operates the motor 7 bringing the magnetic head 3 to the track indicated by the output of the data selector 34 according to the output of the comparator 35. In this instance, the output level of either "A>B" or "A<B" of the comparator 35 is high until the magnetic head 3 reaches the designated track. Therefore, the output level of the AND gate 40 becomes high. The output level of the OR gate 41 also becomes high. Then, the timer circuit 14 of FIG. 1 is kept at reset. Then, when the magnetic head 3 reaches the designated track, the output level "A=B" of the comparator 35 becomes high. As a result, the step motor drive circuit 37 stops the step motor 7. The magnetic head 3 stops at that position. The tracking control circuit 8 then performs tracking control over the magnetic head 3 for the designated track under this condition. Meanwhile, with the low output level of the OR gate 39 becoming low in this instance, the output level of the AND gate 40 becomes low. The output level of the OR gate 41 also becomes low. Therefore, the timer circuit 14 begins to perform a time count. Then, after the lapse of the predetermined period of time, the timer circuit 14 produces a signal the level of which remains high for a predetermined period of time. During this period, the switch circuit 15 remains on allowing a correction signal produced from the tracking control circuit 8 to be memorized in the memory circuit 11. If another track is designated by the ten-key board 28 before the lapse of the count time of the timer circuit 14, the output level of the AND gate 40 again becomes high resetting the timer circuit 14. Therefore, in that instance, the memory circuit 11 does not memorize the correction signal there.
To operate the timer circuit 14 in the above manner, the timer circuit 14 may consist of a C-R (capacitor-resistor) time constant circuit, a threshold comparator, a one-shot circuit (monostable multivibrator) when produces a signal the level of which becomes high and remains high for a predetermined time period, in response to the output of the comparator, etc.
In the continuous reproducing mode, or in the search mode, information on the address of a track with which the continuous reproduction is desired to commence is put into the memory circuit 31 via the ten-key board 28. The continuous reproducing mode switch 27 is operated, thereby setting the RS flip-flop 29. The level of the output Q of the flip-flop 29 becomes high and that of the output Q low. The high level of the output Q connects the switch circuit 9 to the terminal "b" supplying the output of the memory circuit 11 to the drive circuit 10. The output datum of the memory circuit 31 is preset into the counter 32. The data selector 34 selects the output of the counter 32. Furthermore, in this instance, the timer circuit 14 of FIG. 1 is kept reset with the output of the OR gate 41 at a high level.
Then, the magnetic head 3 is moved by the driving action of the motor 7 caused by the motor drive circuit 37 depending on the output of the comparator 35 in the same manner as previously described. However, in the continuous reproducing mode, track changing pulses produced from the pulse generation circuit 33 cause the counter 32 to count up and, accordingly, the moving action on the head 3 comes to be continuously performed. Furthermore, in this instance, the track change pulses from the pulse generation circuit 33 preferably have their period selectable according to the operation mode selected, such as the continuous reproducing mode, the motion picture reproducing mode, the search mode, etc.
In the continuous reproducing mode, since the switch circuit 9 is connected to the terminal "b" as mentioned above, the output of the memory circuit 11 is supplied to the drive circuit 10. Therefore, the positioning action of the magnetic head 3 for each track is fixedly accomplished on the basis of the correction signal which is obtained by the tracking control circuit 8 in the single track reproducing mode.
In accordance with the invention, as has been described in detail, the arrangement of memory means, which memorizes information on the tracking control over the transducer, permits interchangeability among different apparatus through a relatively simple arrangement. The arrangement also permits appropriate control even in an operation mode in which the transducer must be allowed to successively gain access to a plurality of recording tracks, such as in a continuous reproducing operation or a searching operation. Furthermore, the apparatus according to the invention is capable of very stable control even in the above operation mode, allowing the transducer to successively gain access to a plurality of recording tracks.
In the specific embodiment given above, the recording medium is a magnetic disc 1. However, the magnetic disc may be replaced with an optical disc 1, an electrostatic capacity type disc or the like or may be replaced even with a drum type recording medium. Furthermore, the invention is also applicable to an apparatus using a tape-shaped recording medium such as a VTR (video tape recorder), particularly advantageous for carrying out reproduction of a still picture, an intermittent picture, frame feeding reproduction, etc. | A reproducing apparatus for reproducing a disc type signal bearing medium, which includes a reproducing transducer head and an automatic tracking control device for aligning the head with a selected track of the medium. The control device includes an electromechanical converting element for moving the head, a signal producing circuit for producing a tracking control signal based on the reproduced signal, a memory circuit for memorizing the control signal, and a switching circuit for selectively connecting the converting element with the signal producing circuit and the memory circuit. In a single track reproducing mode, the switching circuit connects the converting element with the signal producing circuit, and in a successive track reproducing mode, the switching circuit connects the converting element with the memory circuit. | 6 |
FIELD OF THE INVENTION
The present invention relates to a slagging furnace for cooling a high temperature gas mixture containing both vaporous inert ash material and vaporous potassium seed compounds, and more particularly to a slagging furnace wherein said inert ash material and said seed compounds are condensed and collected separately so as to improve the potential of the recovered seed compounds for recycling.
BACKGROUND OF THE INVENTION
Among the many possibilities for increasing the efficiency of the conversion of coal or other fossil fuels into electric power is open-cycle magnetohydrodynamic power generation (MHD). A typical open-cycle MHD system includes a combustor for generating a high velocity stream of high temperature, ionized gaseous products and a generating channel through which the high temperature gas mixture passes while being subjected to a strong magnetic field. The swift passage of the gaseous ions transversely through the magnetic field induces a flow of current in the gas which may be tapped by means of electrodes in the channel walls. Conversion efficiencies of 90% or better are theoretically possible in such an arrangement.
As the inducement of current flow is dependent upon the degree of ionization in the high temperature gas mixture, most proposed MHD systems specify the addition of a chemical "seed" such as potassium carbonate or potassium sulfate which functions to lower the mixture ionization temperature and thus augmenting the degree of ionization. Typical channel exit gas temperatures are in the range of 3800° to 3600° F. (2093° to 1982° C). As the amount of heat energy in the exiting gas mixture is still quite large, a heat recovery furnace is utilized downstream of the generating channel to recover the heat present in the gas mixture and to convert that heat into high pressure steam for use in driving a generating steam turbine.
Economic studies have shown that in order to successfully compete with less efficient, but simpler, power plant cycles utilizing coal as a fuel, an open cycle MHD generating station must effectively recycle the potassium seed material. There is currently a technological need for a waste heat recovery system that will facilitate condensation and recovery of the potassium seed compounds in a form which is amenable to recycling the recovered compounds to the high temperature coal combustor.
SUMMARY OF THE INVENTION
The present invention provides a furnace unit for recovering useful heat and potassium seed material from the exhaust gas stream of an MHD generating channel. Cooling and dwell times of the gas are managed within the unit according to the present invention to reduce the level of nitrogen oxides in the gas and to condense the gaseous potassium seed as a flyash for optimal recovery and eventual recycle to the high temperature MHD combustor.
Hot gas from the MHD channel is routed into the dwell furnace of the unit where it is cooled to a temperature less than the condensation temperature of the inert ash material carried over from the upstream high temperature converter. The cooled gas mixture, still containing gaseous potassium seed, is then ducted upward into a convection furnace through a transition section which includes a restricted flow area, or throat, for increasing gas velocity therethrough.
Inside the convective furnace, the mixture is further cooled, resulting in condensation and, eventually, solidification of the potassium seed compounds. The solidified seed is collected downstream of the unit for eventual recycling to the high temperature combustor.
It is an advantage of the heat recovery unit according to the present invention that the condensation of inert ash and the condensation of potassium seed each occur in separate furnaces, thus reducing the intermingling of these compounds which can reduce the recoverability of the valuable potassium seed.
It is also a feature of the heat recovery unit according to the present invention that any condensed liquid seed material collecting and running down the convective furnace walls or heat transmission surfaces will eventually flow into the restricted throat of the transition section and to be re-entrained in the high velocity. entering gas stream. This re-entrainment allows further cooling of the liquified slag, eventually forming solid particles which may be collected downstream for recycle to the combustor.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 shows a side elevation of the heat recovery unit according to the present invention.
FIG. 2 shows a sectional view of the transition duct as indicated in the preceding figure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A thorough discussion of the heat recovery unit according to the present invention will now be presented with reference to the drawing figures, and especially to FIG. 1 wherein a side sectional elevation of the preferred embodiment of the present invention is shown.
Coal-fired open cycle MHD power generation systems utilize a hot gas mixture which includes, besides the typical products generated during the combustion of the reactive portion of the coal fuel, at least some inert ash and a quantity of added seed compounds. At typical temperatures present at the exit of the MHD combustor, 4500° F. (2482° C.) or higher, both the inert ash material (primarily silica) and the potassium seed exist only in the vaporous state. Both the inert and seed materials remain gaseous at the exit of the channel, although a portion of the inert ash may be condensed on the cooled channel walls as a flowing liquid slag.
The apparatus and process for generating the high temperature, high speed ionized gas stream and generating electric power therefrom is well known to those skilled in the art of open cycle magnetohydrodynamic power generation. The basic concept originated in the pioneering work of Michael Faraday, with considerable refinement and adaptation occurring in the 1960's and 70's by various research laboratories and power equipment manufacturers. As the methods and apparatus used in the topping portion of the MHD cycle are not directly relevant to the subject matter of this application, no further discussion of this technical material will be presented herein. Further information may be had by reviewing articles and technical manuals available on the subject, such as the discussion presented in Combustion, Fossil Power Systems, pages 24-28 to 24-34, Combustion Engineering, Inc., 1981.
The hot gas exiting the MHD generating channel, having a temperature in the range of 3600° F. (1982° C.) to 3900° F. (2148° C.) , still retains a great deal of heat energy which may be usefully converted into high pressure steam and hence electric power. It is to a waste heat recovery unit such as that of the present invention that this high temperature gas mixture would be routed for such steam production.
A typical gas composition for the gas mixture entering the dwell furnace appears in the Table below. This analysis was developed by theoretically reacting a typical dried coal with 90% of the quantity of air necessary to completely oxidize the combustible coal components. The analysis also assuaes that 90% of the coal ash has been removed prior to the gas stream entering the waste heat recover.y unit, and that potassium containing compounds have been added to enhance the hot gas ionization level. Each of the tabulated values will therefore change should a different coal be substituted as fuel. What will not change is the fact that any open cycle MHD generation system using coal as a fuel will generate a hot gas stream having sufficient heat energy for useful conversion, will contain vaporous potassium seed compounds which must be condensed, collected, and recycled to the combustor for economic reasons, and will also contain vaporous inert ash material which will condense as the hot gas mixture is cooled and which must therefore be removed from the gas stream for disposal.
TABLE______________________________________EQUILIBRIUM CHANNEL EXIT GAS COMPOSITIONCompound Weight Fraction______________________________________CO.sub.2 0.3047CO 0.0559N.sub.2 0.5270H.sub.2 O 0.0810SO.sub.2 0.0035K.sub.2 SO.sub.4 0.0220Inert Ash 0.0059 1.0000______________________________________
Referring now to FIG. 1, the high temperature MHD gas mixture 2 enters the dwell furnace 4 of the waste heat recovery. unit according to the present invention through the dwell furnace entrance opening 6. The entrance opening 6 is connected to the MHD channel outlet (not shown) by a diffuser section 8 shown in phantom.
The dwell furnace 4 is a water-cooled chamber having a refractory lining 10 for withstanding the extreme temperatures present in the high temperature gas mixture 2. Although the refractory lining 10 does reduce the heat transfer between the water-cooled dwell chamber walls and the contained hot gas, sufficient cooling does take place to reduce the gas temperature to approximately 2850° F. (1566° C. prior to its exit through the dwell furnace exit opening 12.
The particular exit temperature of the cooled gas mixture has been chosen to be above the temperature of condensation of the vaporous potassium seed compounds, 2250° F. (1232° C.) but also within or below the temperature range in which the inert ash material condenses as a liquid slag, 2600°-3100° F. (1426°-1704° C.). A portion of the vaporous inert ash material present in the received gas 2 will therefore condense as a liquid slag upon the inner refractory 10 of the dwell chamber 4 and run downward under the influence of gravity. As can be seen in FIG. 1, the floor 14 of the dwell chamber 4 slopes to a central opening 16 through which the liquid slag is removed from the process.
The choice of the exit gas temperature of the slagging dwell furnace plays an important part in determining the efficiency of the recovery and recycle of the potassium seed material. Should seed and slag be allowed to condense simultaneously, the potassium seed dissolves into the slag in such a manner as to make the separation of the two materials very difficult.
This is to be contrasted with the result which occurs when vaporous seed and ash is condensed and solidified very quickly to form flyash like particles. A flyash combination of seed particles andinert ash particles as may be collected from the cooled gas mixture in an electrostatic precipitator or baghouse located downstream of the waste heat recovery unit can be easily separated into ash compounds and seed compounds by slurrying the collected flyash with water. The potassium, typically present as potassium sulfate, is readily soluble in water unlike the insoluble silica based ash compounds. The potassium solution, separated from the insoluble ash particles, may then be dried or otherwise processed into a form suitable for recycle to the high temperature combustor.
The waste heat recovery unit according to the present invention achieves this desirable second result by preventing the simultaneously liquid condensation and collection of the potassium seed material and inert ash. This separation is accomplished by the configuration of the transition section or duct 18 which conducts the gas mixture from the dwell furnace 4 into the convective furnace 20. The conductive furnace 20 is positioned directly above the dwell furnace 4 and contains a plurality of heat absorbing surfaces 22 located therewithin. These heat transfer surfaces 22, typically cooled by steam, quickly reduce the temperature of the gas mixture within the convection furnace 20 thus condensing and solidifying the seed material and any remaining vaporous ash into tiny particles of flyash which pass through the convection furnace and into the backpass region 24, eventually being collected in turning hopper 26 or in a downstream electrostatic precipitator or baghouse (not shown).
It must be noted at this point, that a significant portion of the remaining vaporous ash and seed material will condense upon the cooled walls and heat transfer surfaces of the convection furnace 20 as a comingled liquid slag which will run downward over the vertical surfaces under the influence of gravity. This liquid ash and slag mixture will attempt to reenter the dwell furnace 4 through the dwell furnace outlet opening 12. The present invention provides for a restriction, or throat, 28 located within the transition section 18 for creating a high velocity upward flow of gas therethrough. The velocity of the gas passing through the throat 28 is sufficient to prevent entry of the liquid seed and inert ash material into the dwell furnace 4, reentraining the condensed material in the upward flowing gas stream and carrying the entrained droplets upward into the convection furnace 20.
The reentrained droplets of inert ash material and potassium seed, again part of the gas stream entering the convection furnace 20, are further cooled to form flyash which carries over into the backpass 24 as described above. It should be recognized that a portion of the reentrained liquid does again adhere to the convection furnace walls and heat transfer surfaces 22 and run down to the throat 28 as a liquid slag. Eventually, during operation of the unit, a seed balance will be achieved such that the mass of seed and ash entering the convection furnace 20 equals the mass of seed and ash leaving as solidifed flyash particles in the gas stream.
The throat 28 of the transition duct 18 is more clearly shown in the sectional view of FIG. 2. The transition duct 18 can also be seen in FIGS. 1 and 2 to have a divergent cross section for providing at least partial recovery of the kinetic energy of the gas mixture passing through the throat 28.
The control of nitrogen oxide emissions to the environment is an important environmental consideration and must be addressed in open cycle MHD power generation. This need arises due to the combined effect of the use of ordinary air (containing 70% nitrogen as the oxidant and the high temperature of the MHD combustor, 5,000° F. (2760° C.) or higher. One leading method for nitrogen oxide control, and the one utilized in the preferred embodiment of the present invention, is to fire the MHD high temperature combustor at 90% of the airfuel stoichiometry thus producing a reducing gas containing a small amount of carbon monoxide as shown in the Table above. The nitrogen oxides produced in the high temperature substoichiometric combustor are unstable in the temperature range between 3300° and 2900° F. (1815° to 1593° C.).
The nitrogen oxides and carbon monoxide present at the exit of the MHD channel will, if held in this temperature range for sufficient time, will react to form carbon-dioxide and nitrogen molecules. Experimental and theoretical evidence has shown that two seconds would be enough time to permit sufficient decomposition of the nitrogen oxides present at the exit of the MHD generating channel. The dwell furnace 4 of the preferred embodiment of the present invention is thus sized to provide at least two seconds of residence time therewithin to accomplish this decomposition.
Although the oxygen bound to the nitrogen does react with a portion of the carbon monoxide present within the dwell furnace 4, carbon monoxide itself is a pollutant which must be eliminated prior to discharge into the environment. This is readily accomplished by adding sufficient oxidant to complete the combustion reaction at temperatures high enough to allow this reaction to occur. In the preferred embodiment of the present invention this oxidant addition is accomplished by secondary air nozzles 30 disposed in the transition duct 18 just above the restricted throat 28. By placing the secondary air ejection nozzles 30 in this location, good mixing of the oxidant and hot gas mixture is facilitated. The flow streams of oxidant will enter the high speed flow stream of gas transversely, thus inducing turbulence and facilitating the mixing of the oxidant and gas mixture. Following addition of the secondary oxidant, the gaseous products in the convection furnace 20 and backpass 24 contain a small percentage of unreacted oxygen, having been converted from a reducing gas to an oxidizing gas.
The dwell furnace and convective furnace of the heat recovery unit according to the present invention, although unusual in configuration, are constructed basically of water-cooled tubing as are most conventional steam generating furnaces. For a forced circulation steam generator, water from the steam drum 32 flows through downcomer 34 to the circulating pump 36. The pump 36 forces the water into the lower header 38 of the dwell furnace from which it flows generally upwardly through the waterwall tubes wherein the heat absorbed from the contained hot gases boils a portion of the circulating water into steam. The steam water mixture is collected at the top of the convective furnace 20 and routed back to the steam drum 32 for separation into water and steam. The main steam line 40 conducts the separated steam through the roof 42 of the heat recovery unit or into the superheater inlet headers 44 of the heat transfer surfaces 22. In this arrangement, the heat transfer surfaces 22 and unit roof 42 act as superheaters for the generated steam.
Both the advantages and features of the present invention discussed above, as well as others, will become apparent to one skilled in the art upon careful review of the preceding specification and the appended drawing figures. It should further be understood that the embodiment disclosed herein is presented as being, in applicant's opinion, the best mode for practicing the present invention, and should therefore be interpreted in an illustrative and not a limiting sense. | A two part heat recovery unit receives a high temperature gas mixture (2) in the lower, refractory-lined dwell furnace (4) wherein the gas is cooled to condense out liquid inert ash material. The cooled gas mixture exits the dwell furnace (4) vertically upward through a transistion duct (18) which includes a restricted throat (28). Additional ash and potassium seed compounds condensed from the gas mixture in the convective furnace (20) either form a loose flyash which exits the convective furnace (20) with the gas mixture via the backpass (24), or collect on the walls and heat transfer surfaces (22) of the furnace (20) as a liquid which runs downward toward the throat (28) and is there reentrained by the high velocity gas stream. | 7 |
The present invention generally relates to an ammunition canister and more specifically is directed to a lightweight canister which may be loaded with rounds at an ammunition facility with a built-in hermetic seal and little dunnage.
A great number of ammunition feed and storage systems have been designed in the gun industry which are specifically configured and limited to a certain extent in their versatility to a specific weapon.
In many instances, canisters and magazines handling a large amount of ammunition can encounter problems due to lack of ammunition control within the canister and gun power requirements necessary to forward feed the ammunition rounds from the canister.
Further, conventional ammunition canisters and magazines have been made from metal and/or wood and thus require a highly sophisticated work force and a large capital investment for tooling. In this regard, there are only a few facilities currently in production in the United States, which creates a user drawback and little opportunity for effective competition. In addition, because of these factors, it is difficult to rapidly expand production during times of surge production requirements.
In addition, typical ammunition systems include a conventional gun magazine utilized in separate wooden or metal containers to separately transport the ammunition and the magazines. Hence, the end user must transfer the ammunition from a shipping and storage container to a magazine. Additionally, if downloading is required, dunnage recovery may now become a problem.
A canister in accordance with the present invention overcomes the hereinabove-recited problems and provides a high ammunition density pre-loaded canister, utilizing recyclable plastic, and further provides power assistance to the gun for ejecting ammunition rounds from the canister, thereby reducing drag by the gun and ensuring proper firing rate for the gun.
SUMMARY OF THE INVENTION
An ammunition canister, in accordance with the present invention, generally includes an injection molded housing, which more specifically may include a pair of injection molded outer shells, with each shell configured for assembly with one another to form an ammunition canister. Each shell is also formed with guide surfaces for controlling movement of ammunition rounds within a canister.
In addition, an injection molded sprocket means, which includes a drive sprocket and an idler sprocket are provided for moving the ammunition rounds within the canister.
An injection molded spring housing assembly, rotatably mounted to one of the shells, enables a spring to apply a torque to the drive sprocket and crank means is provided for tension and spring, along with ratchet means for engaging the outer shell so that tension may be maintained on the sprocket.
Preferably, all of the components of the present invention, except for a spring and an O-ring (to be discussed later), are made of plastic. This has significant advantages in that the canister may be manufactured from non-strategic materials and a dedicated factory is neither required nor desired, since component molds can be inserted into general purpose molding machines.
As is well-known in the art, such machines are computer controlled and thus precision requirements can be met with a relatively low technical labor force. In addition, requirements for a large capital investment are significantly reduced and since the molds and the computer software are easily transportable, they can be shifted from one venue to another while maintaining quality, high production rates, and cost competitiveness.
In addition, when the canister is no longer serviceable, it may be recycled, further reducing the life cycle cost and, importantly, addressing current environmental considerations. The canister uses no dunnage for round separation and protection, as is used in conventional weapons, thus simplifying recovery.
Further, this design approach is applicable to essentially all types of linked or unlinked ammunition. And, with the exception of the spring and O-ring, the canister may be totally recycled and, in addition, because there is no dunnage required, there is no trash to dispose of or pick up after use. This feature is consistent with today's environmentally conscious population.
More specifically, the ammunition canister, in accordance with the present invention, may be injection molded from a plastic material having sufficient translucence to enable visual verification of a quantity of ammunition rounds disposed within the canister. In addition, the position of ammunition rounds within the canister may be verified and an operation status of the canister determined by the detection of jammed rounds or obstacles within the canister impeding proper canister operation.
Importantly, this translucency enhances the reloadability of the canister in the field. A user can easily determine the number of rounds required and ensure that the rounds inserted into the canister are properly rooted therein, along the guiding surfaces, thereby reducing chances of creating ammunition jamming within the canister during reloading.
More particularly, the driver and idler sprockets may be identical in size and shape. This feature enables a reduction in the number of molds necessary for the production of the subject canister.
Still more particularly, the canister in accordance with the present invention may include an injection molded, non-detachable cover and means enabling permanent assembly with the pair of injection molded outer'shells. The cover may be hinge mounted and have integrally molded thereinto latch means for engaging the shells in order to lock the cover over an ammunition exit port.
An injection molded latching pawl means may also be provided for preventing inadvertent ejection of ammunition rounds when the spring is tensioned and the cover is in an open position.
BRIEF DESCRIPTION OF INVENTION
Other features and advantages of the invention will appear from the claims and from the following description of certain embodiments of the invention, given by reference to the drawing which shows essential details of the invention, it being understood that the individual features may be implemented in any embodiment of the invention, individually or in any combination thereof.
In the accompanying drawings:
FIG. 1 is a perspective view of an ammunition canister in accordance with the present invention showing a pair of injected molded outer shells, a crank assembly designed for tensioning a spring within the housing (not shown in FIG. 1) and end cover;
FIG. 2 is a plan cross-sectional view of the canister shown in FIG. 1 with the end cover in an opened position;
FIG. 3 is an enlarged view of the spring crank assembly in accordance with the present invention;
FIG. 4 is a cross-sectional view of the crank assembly shown in FIG. 3.
FIG. 5 a view similar to FIG. 3, showing the crank assembly in an open position;
FIG. 6 is a cross-sectional view of the crank assembly shown in FIG. 5; and
FIG. 7 is an enlarged exploded perspective view of ammunition carrier links in accordance with the present invention.
DETAILED DESCRIPTION
Turning now to FIG. 1, there is shown an ammunition canister 10, in accordance with the present invention, which generally includes a pair of injection molded outer shells 12, 14 and end cover 18 along with a crank assembly 20. The shells 12, 14 are preferably injected molded with any suitable recyclable plastic, as hereinabove noted.
As shown in FIG. 2, integral to the shells 12, 14 are guide surfaces 24 for providing control of the ammunition (not shown in FIG. 2) movement through the canister 10 to an exit port 28.
As shown in FIGS. 3-6, the shell 12 includes an opening 32 molded thereinto for acceptance of the crank assembly 20. The crank assembly 20 includes a rotor 34 fitted to a top 38 of a sprocket 42 which is mounted for rotation between the shells 12, 14. Any conventional method may be utilized for joining the sprocket top 38 under rotor 34. Hinge 46 mounted to a top 48 of the rotor 34 is a crank handle 52 which is pivotable from a closed position, shown in FIGS. 3 and 4, to an open position, shown in FIGS. 5 and 6, the latter position enabling the tightening of a coil spring disposed on an underside 58 of the rotor 34. A spring 56 has one end 64 fixed to a sprocket top 38 by means of a slot 66 with another end 70 fixed to an inside surface 74 of the rotor 34.
The rotor 34 is rotatably mounted within the opening 32 and sealed therein by a means of an O-ring 80. Upon assembly of the shells 12, 14, together with the sprocket 42 therebetween, a lip 82 prevents separation of the rotor 34 from the shell 12.
The crank handle 52 may be held in the stowed position, as shown in FIG. 3, a depending member 86 engaging an opposite facing 88 formed adjacent the opening 32 in the shell 12.
In the open, or actuated, position shown in FIGS. 5 and 6, a fixed pawl surface 90 engages ratchet-like indentations 94 formed in the lip 82 to enable the of the crank handle 52 to be turned for rotating the rotor 34 and charging spring 56 and maintaining the spring charge by preventing rotation of the rotor 34 in an opposite direction.
The spring charge is transferred by sprocket arms 98 to ammunition rounds 100 via ammunition clips 102, as shown in FIG. 7. The drive sprocket 42 works in concert with an idler sprocket 106 for moving the ammunition 100 through the guide surfaces 24 molded into the shells 12, 14. Each ammunition clip includes outboard surfaces 108, 110 for slidably engaging the guide surfaces 24 to the smooth movement of the ammunition rounds within the canister and out through the exit port 28.
The idler sprocket 106 and the drive sprocket 42 may be injected molded from the same material as the shells 12, 14 and are preferably identical in size and shape, so that the same die may be used for each of the drive and idler sprockets 42, 106. This commonality of parts lowers the cost and simplifies the overall construction of the canister 10.
Idler sprocket 106 is mounted between the shells 12, 14 on assembly by means of holes 114 in the shells 12, 14.
It should be appreciated that the flat coil spring 56 is the only metallic item utilized in the canister 10 that may be of typical high carbon steel used for springs with corrosion protection provided through the use of conventional corrosion resistant sprays or by plating with a nickel, cadmium or other coating compatible for applications of this type.
It should also be appreciated that the canister 10, according to the present invention, enables the storage of ammunition rounds 100 and spring-assisted deployment of the rounds 100 without the necessity of maintaining the spring tension during storage. That is, ammunition rounds 100 may be fed into the canister 10 via the port 28 and immediately prior to the use of the canister, the spring 56 may be tensioned by rotation of the crank handle.
Ammunition rounds 100 are prevented from ejection through the port 28 by the injection molded, nondetachable cover 18, which is held in a closed position by means of outwardly projecting end tabs 118 which engage a holding surface 120 molded into the shells 12, 14, as shown in FIG. 1.
The cover may be molded from the same material as the shells and is attached thereto during assembly. The cover 18 is hinged by pins 122 molded into the shells 12, 14 which enable the lid 18 to be folded to an out-of-the-way position as shown in FIG. 2. The tabs 118 are sufficiently large to enable a user for admittance to open the lid from its latched position, as shown in FIG. 1, to the open position, as shown in FIG. 2. As shown, the lid includes molded reinforcement members 124 in the form of an X in order to reduce plastic volume and weight of the canister 10.
In order to prevent inadvertent ejection of the ammunition rounds 100 from the canister 10 when the lid is opened, an ejection-molded locking pawl 128 is pivotally mounted between the shells 12, 14 by means of a pin 130 or the like. A short leg 132 of the pawl 128 bears against the lid 18 when in a closed position, thus enabling a long leg 134 to engage an ammunition round and then movement thereof towards the lid.
After a spring 56 is wound, the drive sprocket 42 provides a bias of the ammunition rounds 100 and clips 102 against the long leg 134, preventing ejection of the ammunition rounds and clips from the exit 28 when the lid is in an open position, as shown in FIG. 2. The locking pawl 128 is released when the canister is inserted into a gun and a protruding member (not shown) of the gun urges the long leg 134 out of engagement with the ammunition round 100 and clip 102.
Turning again to FIG. 7, the clips 102 may be coupled to one another through a slot 138 and a coupler 140, pivotally mounted between molded openings 142, 144 in each clip 102.
Although there has been hereinabove described a self-powered ammunition feed and storage canister in accordance with the present invention, for the purpose of illustrating the manner in which the invention may be used to advantage, it should be appreciated that the invention is not limited thereto. Accordingly, any and all modifications, variations, or equivalent arrangements which may occur to those skilled in the art, should be considered to be within the scope of the present invention as defined in the appended claims. | An ammunition canister includes a pair of injection molded outer shells with each shell configured for assembly with another shell to form the ammunition canister. Each shell is molded with guide surfaces for controlling movement of ammunition rounds within the canister. An injection molded spring housing assembly, rotatably mounted to one of the shells, includes a spring for applying torque to said drive sprocket and a crank and ratchet are provided for tensioning the spring. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to germinated brown rice which can be easily boiled by a household rice cooker and is high in shelf-life stability. The present invention also relates to a process for treating brown rice, by which occurrence of cracked rice kernel or broken rice after drying is reduced.
2. Description of the Background Art
Germinated brown rice is evaluated as functional food because it is good in digestion and uptake and contains nutrient components such as γ-aminobutyric acid and ferulic acid in plenty compared with ordinary brown rice. However, cooked germinated brown rice is rough in mouth feel and unpleasant in flavor though the germinated brown rice may be cooked by an ordinary household rice cooker. Germinated brown rice subjected to, for example, steaming for at least 20 minutes, cooling, packaging as it is and heat sterilization, in order to facilitate boiling is broken or cracked in rice kernel because it contains water in plenty and moreover has been subjected to the heat treatment twice. Therefore, such germinated brown rice involves such problems that its appearance after boiling is impaired, it gives stink of bran and sticky feel upon eating and the cooked brown rice becomes quickly hard in mouth feel when it cools. So the use of the germinated brown rice is not always popular. In order to improve its mouth feel, it is possible to apply a process of cooking brown rice by an existing pressure rice cooker, which is performed as a method of cooking the brown rice, to the germinated brown rice. However, such a process involves a demerit of destroying rich nutrients of the germinated brown rice, such as vitamin B.
The germinated brown rice itself absorbs water in plenty in a germination process thereof, and so its shelf-life stability becomes poor and a problem arises from the viewpoint of distribution. Therefore, it has been necessary to cope with such a problem by, for example, vacuum packaging a small amount of heat-treated germinated brown rice, such as an amount of one meal, and further heat sterilizing it. When the germinated brown rice is vacuum packaged, however, a problem of handling arises when it is used in processed food of the germinated brown rice or for business purpose. Therefore, such treated germinated brown rice involves a problem that it is lacking in general-purpose properties from the viewpoints of processability and distribution property.
It is considered to dry germinated brown rice as a means for enhancing the shelf-life stability and distribution property of the germinated brown rice. However, the germinated brown rice, in which water has been contained in plenty in the germination process, involves a problem that cracking or breaking of rice kernel is often caused and its yield after the drying is lowered. On the other hand, it is also conducted to slow the drying speed to prevent the occurrence of cracked rice kernel and broken rice. However, it takes a considerably long time to dry the germinated brown rice to an ideal water content for improving shelf-life stability. There has thus been a demand for an effective means for industrially drying germinated brown rice.
SUMMARY OF THE INVENTION
It is a first object of the present invention to provide germinated brown rice which can be easily and deliciously cooked even by a household rice cooker without impairing its original nutritive value, and at the same time, is not accompanied by marked deterioration of mouth feel even when cooked germinated brown rice cools and moreover has excellent shelf-life stability.
A second object of the present invention is to provide germinated brown rice which can be cooked easily and has excellent shelf-life stability and is reduced in occurrence of cracked rice kernel or broken rice.
The present inventors have carried out an extensive investigation. As a result, it has been found that the first object can be achieved by controlling the water content, degree of gelatinization and preferably water absorption upon immersion in water of germinated brown rice. It has also been found that the second object can be achieved by controlling the water content and degree of gelatinization of germinated brown rice by subjecting the germinated brown rice to a steaming treatment or heat-moisture treatment and drying the treated germinated brown rice.
According to the present invention, there is thus provided germinated brown rice the water content of which is 10 to 18% by mass and the degree of gelatinization of which is 5 to 50%.
The germinated brown rice according to the present invention may preferably have a water absorption rate of 110 to 140% upon immersion in water.
According to the present invention, there is also provided germinated brown rice obtained by subjecting germinated brown rice to a heat-moisture treatment and drying the treated germinated brown rice to a water content of 10 to 18% by mass and a degree of gelatinization of 5 to 50%.
According to the present invention, there is further provided a process for treating germinated brown rice, which comprises removing water attached to the surface of the germinated brown rice to an extent that the germinated brown rice becomes an almost single kernel state, subjecting the germinated brown rice of the almost single kernel state to a heat-moisture treatment and then drying the treated germinated brown rice to a water content of 10 to 18% by mass and a degree of gelatinization of 5 to 50%.
According to the present invention, there can be provided germinated brown rice which can be cooked easily and has excellent mouth feel and shelf-life stability. According to the present invention, there can also be provided a treating method of germinated brown rice which can be cooked easily and has excellent shelf-life stability and is reduced in occurrence of cracked rice kernel or broken rice.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The water content in the germinated brown rice as referred to in the present invention may be generally 10 to 18% by mass, preferably 12 to 18% by mass, more preferably 13 to 16% by mass. If the water content is lower than 10% by mass, each kernel of such germinated brown rice tends to cause cracking or breaking, and so such germinated brown rice involves a problem that the taste of cooked germinated brown rice is impaired. If the water content exceeds 18% by mass on the other hand, mold, bacteria and the like are easy to gather, and so a problem arises from the viewpoint of shelf-life stability.
The degree of gelatinization as referred to in the present invention means a value determined in accordance with the β-amylase.pllulanase method (BAP method). The BAP method is an excellent method for distinguishing gelatinized starch from raw starch or retrograded starch. The degree of gelatinization of the germinated brown rice according to the present invention may be 5 to 50%, preferably 5 to 30%, more preferably 10 to 20%. If the degree of gelatinization of the germinated brown rice is lower than 5%, such germinated brown rice involves problems that it is rough in mouth feel when boiled together with polished rice and that an incidence of cracked rice kernel or broken rice becomes high upon its drying. If the degree of gelatinization exceeds 50% on the other hand, blocking among rice kernels occurs, and so handling in the drying process becomes hard, and drying efficiency also becomes poor. In addition, when the germinated brown rice is blended with polished rice to boil the blend, only the germinated brown rice becomes too soft, and so balance of mouth feel after the cooking becomes poor.
The degree of gelatinization can be controlled to the desired value by, for example, suitably adjusting conditions of the heat-moisture treatment and drying in the production of the germinated brown rice. For example, when drying speed is made mild like solar drying to subject the germinated brown rice to no heat treatment, the degree of gelatinization amounts to about 5 to 15%. When the germinated brown rice is steamed at 98° C. for about 5 to 20 minutes, or heated and dried at 60° C. for about 40 minutes or at 80° C. for about 25 minutes, the degree of gelatinization amounts to about 10 to 50%.
The water absorption upon immersion in water as referred to in the present invention is found by using water of 25° C., immersing a germinated brown rice sample at room temperature for 30 minutes in water and dividing the weight of the germinated brown rice sample after immersion by the weight of the germinated brown rice sample before the immersion and is expressed by %. In the present invention, the water absorption rate upon immersion is preferably 110 to 140%, more preferably 112 to 138%. If the water absorption rate is lower than 110%, the boiled germinated brown rice is half-done, and rice kernels after cooled become hard and have a dry mouth feel. If the water absorption rate exceeds 140% on the other hand, such germinated brown rice looses its shape when it is cooked, and the germinated brown rice tends to have a sticky feel. Therefore, not only a mouth feel, but also its appearance is spoiled. The water absorption upon immersion is also related to the water content in the germinated brown rice. Germinated brown rice having low water content is high in water absorption, and germinated brown rice having high water content is low in water absorption. However, the water absorption upon immersion is greatly affected by not only water content, but also peeling off and damage of the surface of germinated brown rice. Accordingly, the water absorption rate can be controlled by controlling the water content and conducting peeling. The more the surface of germinated brown rice is peeled, the more its water absorption rate is made high.
The water content, degree of gelatinization and water absorption upon immersion can be controlled to respective desired values by determining conditions of peeling, heat-moisture treatment and drying by conducting experiments properly.
The germinated brown rice according to the present invention can be prepared in accordance with, for example, the following process.
Brown rice is immersed in a germination tank (tank for germination) as it is or after a part of the brown rice is peeled off by a rice whitening machine, rice washer or the like to cause peeling off and damage of its surface, and the thus-obtained brown rice is washed 2 to 4 times with water and then dewatered. The peeling may be conducted after the immersion. The brown rice may be peeled to preferably 95 to 99.8% by mass, more preferably 97 to 99% by mass. By such a treatment, foreign matter and microorganisms attached to the surface of the raw brown rice can be removed, and the amount of water required of rice washing can also be reduced. As described above, the degree of peeling affects the water absorption upon immersion and percentage germination. Therefore, the degree of the peeling can preferably be determined taking this point into consideration. The water used in the rice washing may be any of tap water, distilled water, well water, acid water, electrolytic brine, water in which ozone has been dissolved, etc. so far as it is water usable for food.
With respect to conditions of immersion in the germination tank, there is a method that the brown rice is immersed in warm water of generally 20 to 50° C. until the brown rice is germinated, or immersed for, for example, about 3 to 5 hours, dewatering is conducted thereafter, and water spraying is intermittently conducted to germinate the brown rice for the predetermined period of time under high-humidity conditions. As examples of the warm water used, may be mentioned the water described in the rice washing process, and any water may be used so far as it is water usable for food.
The germination may be conducted to a state that a swelling, protuberance or plumule of about 0.5 to 2.0 mm from an embryo can be recognized. After the germination, the germinated brown rice is subjected to a heat treatment in order to stop germination. In order to stop germination, the germinated brown rice may be steamed, or treated at a proper temperature or dried by a suitable method such as the use of hot air or microwaves or cooling.
The germinated brown rice is discharged from the germination tank to transfer it to the next drying process. Before drying, it is preferred that water attached to the germinated brown rice be removed to an extent that the germinated brown rice becomes an almost single kernel state, and the germinated brown rice be subjected to a heat-moisture treatment and then dried. The single kernel state means a state that most of kernels of the germinated brown rice are not bonded to one another with water attached to the surfaces thereof. By this state, handling upon the heat-moisture treatment and drying process is conducted with ease, and so attachment of kernels to one another or a wall surface of an apparatus, unevenness of degree of gelatinization and drying irregularity can be prevented, and drying efficiency can also be improved. The removal of water attached to the surfaces can be conducted by, for example, putting the germinated brown rice discharged on a draining conveyer. At this time, the water attached to the surfaces can be efficiently removed by vibrating the conveyer or conducting ventilation. It is more preferred that agitation be conducted by a rotating blade having a agitating function, screw or the like as needed.
Specifically, the heat-moisture treatment is a process in which a subject is heated by using, as a heating medium, saturated steam or hot water in a high-humidity atmosphere, for example, an atmosphere of at least 60% humidity. In this case, either a heating method in which the subject to be heated is brought into direct contact with the heating medium or a heating method in which the subject is brought into indirect contact with the heating medium like an indirect heating system, for example, in an atmosphere of at least 60% humidity may be performed. With respect to specific conditions, the treatment may be conducted, for example, at a steam temperature of 98 to 180° C. for 3 seconds to 30 minutes. If the steam temperature is lower than 98° C., the time required for the desired gelatinization is elongated. Therefore, such a low steam temperature is not very preferable when industrial mass production is performed. If the steam temperature exceeds 180° C. on the other hand, a problem that the gelatinization is allowed to too progress is caused, and so the immersion time is limited, and the mouth feed of boiled germinated brown rice is deteriorated when the immersion is conducted for a long period of time. If the treatment time is shorter than 3 seconds, irregularities may occur on the degree of gelatinization of rice kernels, and the control in the practical process is also difficult. If the treatment time exceeds 30 minutes on the other hand, the gelatinization of the germinated brown rice is allowed to too progress, and the swelling of rice kernels occurs. Therefore, kernels of the resulting germinated brown rice are easy to be collapsed when the germinated brown rice is blended with polished rice and immersed for a long period of time.
A steaming treatment of rice, which is used in boiled rice production, fermentation industry and the like, may be mentioned as an example of another method than the above-described method. Specifically, for example, brown rice subjected to the germinating treatment is treated with steam for 3 seconds to 30 minutes, preferably 10 seconds to 30 minutes under conditions of 0.1 to 7.0 kg/cm 2 , preferably 0.1 to 2.0 kg/cm 2 . If the steam pressure is lower than 0.1 kg/cm 2 , the preventive effect on the occurrence of cracked rice kernel or broken rice is lessened. The same shall apply to the treatment time shorter than 3 seconds. If the treatment time is too long on the other hand, the gelatinization is allowed to too progress, and so the resulting germinated brown rice tends to deteriorate the mouth feel when boiled together with polished rice, easily cause blocking between kernels and deteriorate handling in the drying process. On the other hand, even if the steam pressure exceeds 7.0 kg/cm 2 , the preventive effect on the occurrence of cracked rice kernel or broken rice is achieved. However, too high pressure involves a problem of safety.
The drying may be conducted by any of convective (hot air) drying method, radiation drying method, indirect drying method, evenly heating method by electromagnetic waves or the like, vacuum drying method, lyophilization method, etc.
When tempering is conducted before the desired water content is reached in the drying process, beautiful finish can be achieved, and the occurrence of broken rice can be reduced to a greater extent.
When the raw brown rice is peeled in advance, the drying time can be shortened, and it is possible to soften hard pericarp and lessen emission of offensive smell. When a part of surface of the germinated brown rice is whitened to peel off or damage it, it is also possible to more soften hard epidermis and lessen emission of offensive smell.
The germinated brown rice according to the present invention may be used for food by boiling it either singly or in combination with brown rice or polished rice, or as a raw material of rice confectionery such as rice crackers, and processed foods such as bread and behon. As needed, intensification of nutrition may be conducted with functional components such as vitamins, minerals, γ-orizanol, tocotrienol and ferulic acid by a proper treatment such as water absorption by immersion or coating.
The present invention will hereinafter be described in detail by the following Examples.
EXAMPLE 1
Raw brown rice (Hinohikari, trade name; from Kagawa) was washed by a rice washer and immersed for 24 hours in water controlled to a constant temperature of 30° C. to be germinated. Thereafter, the thus-treated brown rice was steamed at 98° C. for 2 minutes and then subjected to fluidized bed drying at 80° C. for 20 minutes to obtain germinated brown rice.
EXAMPLE 2
Raw brown rice (Koshihikari, trade name; from Nagano) was washed by a rice washer and immersed for 24 hours in water controlled to a constant temperature of 30° C. to be germinated. Thereafter, the thus-treated brown rice was steamed at 98° C. for 20 minutes, cooled and then subjected to fluidized bed drying at 80° C. for 20 minutes to obtain germinated brown rice.
EXAMPLE 3
Raw brown rice (Koshihikari, trade name; from Niigate) milled so as to give a milling yield of 98.5% was immersed for 24 hours in water controlled to a constant temperature of 30° C. to be germinated. Thereafter, the thus-treated brown rice was steamed at 98° C. for 2 minutes and then subjected to fluidized bed drying at 80° C. for 20 minutes to obtain germinated brown rice.
EXAMPLE 4
Raw brown rice (Akitakomachi, trade name; from Akita) milled so as to give a milling yield of 99.9% was washed by a rice washer and immersed for 24 hours in water controlled to a constant temperature of 30° C. to be germinated. Thereafter, the thus-treated brown rice was subjected to fluidized bed drying at 80° C. for 20 minutes to obtain germinated brown rice.
COMPARATIVE EXAMPLE 1
Raw brown rice was treated in the same manner as in Example 1 except that the water content of germinated brown rice after the fluidized bed drying was controlled to 18.7% by mass to obtain germinated brown rice.
COMPARATIVE EXAMPLE 2
Raw brown rice (Koshihikari, trade name; from Nagano) was washed by a rice washer and immersed for 24 hours in water controlled to a constant temperature of 30° C. to be germinated. Thereafter, the thus-treated brown rice was steamed at 98° C. for 20 minutes and cooled to obtain germinated brown rice having a water content of 36.9% by mass.
COMPARATIVE EXAMPLE 3
Raw brown rice (Koshihikari, trade name; from Nagano) was washed by a rice washer and immersed for 24 hours in water controlled to a constant temperature of 30° C. to be germinated. Thereafter, the thus-treated brown rice was steamed at 98° C. for 20 minutes, cooled and then subjected to fluidized bed drying at 80° C. for 45 minutes to obtain germinated brown rice the water content of which was controlled to 9.5% by mass.
COMPARATIVE EXAMPLE 4
Raw brown rice (Hinohikari, trade name; from Kagawa) milled so as to give a milling yield of 94% was immersed for 24 hours in water controlled to a constant temperature of 30° C. to be germinated. Thereafter, the thus-treated brown rice was steamed at 98° C. for 30 minutes, cooled and then subjected to fluidized bed drying at 80° C. for 20 minutes to obtain germinated brown rice the water content of which was controlled to 14% by mass.
EXAMPLE 5
Raw brown rice (Koshihikari, trade name; from Nagano) milled so as to give a milling yield of 94% was washed by a rice washer and immersed for 24 hours in water controlled to a constant temperature of 30° C. to be germinated. Thereafter, the thus-treated brown rice was steamed at 98° C. for 20 minutes, cooled and then subjected to fluidized bed drying at 80° C. for 40 minutes to obtain germinated brown rice the water content of which was controlled to 10% by mass.
EXAMPLE 6
Raw brown rice (Koshihikari, trade name; from Nagano) was washed by a rice washer and immersed for 24 hours in water controlled to a constant temperature of 30° C. to be germinated. Thereafter, the thus-treated brown rice was subjected to fluidized bed drying at 80° C. for 13 minutes to obtain germinated brown rice the water content of which was controlled to 18% by mass.
The water contents, water absorption upon immersion in water, degree of gelatinization and fatty acid content of the germinated brown rices obtained in Examples 1 to 6 and Comparative Examples 1 to 4, and the results of a panel test (mouth feel: roughness, glutinousness, odor) and a shelf-life stability test are shown collectively in Table 1. High fatty acid content causes offensive smell and deterioration of the taste. Incidentally, the water absorption upon immersion in water was found by immersing 50 g of each sample of the germinated brown rices obtained in Examples 1 to 6 and Comparative Examples 1 to 4 at room temperature for 30 minutes in 100 ml of water of 25° C. and dividing the weight of the sample after immersion by the weight of the sample before the immersion and was expressed by %. The degree of gelatinization was determined by using a germinated brown rice sample after 1 week from the production of the germinated brown rice as a subject in accordance with the β-amylase.pllulanase method (BAP method). The water content and fatty acid content were analyzed by a method using near infrared rays.
The shelf-life stability was evaluated by heat sterilizing a sample, placing the sample into a polyvinylchloride bag with a zipper and leaving the sample to stand for 1 month. Whether the appearance of the sample was changed or not and offensive smell was emitted or not was confirmed, and the sample was ranked as ∘ where no problem arose (good), or × where a problem arose.
The panel test was conducted by having 9 panelists (20 to 50 years of old) eat a boiled germinated brown rice sample right after the boiling and a cooled sample. The evaluation was made in the following manner. Each sample of the germinated brown rices obtained in Examples 1 to 6 and Comparative Examples 1 to 4 was cooked by an electric rice cooker in immersion time of 30 minutes with water 1.5 times as much as the sample added thereto.
TABLE 1
Degree of
Water absorption
Water content
gelatini-
upon immersion
Fatty acid
Shelf stability (room
(% by mass)
zation
in water (%)
content
temperature, 1 month)
Organoleptic test
Ex. 1
16.3
12.7
124.6
27
◯ (Neither gathered
⊚
mold nor emitted
offensive smell)
Ex. 2
13.3
22.8
118.3
27
◯ (Neither gathered
◯ (Rice kernel had
mold nor emitted
no puffy feel)
offensive smell)
Ex. 3
15.4
13.5
136.2
17
◯ (Neither gathered
⊚
mold nor emitted
offensive smell)
Ex. 4
15.0
14.0
113.7
15
◯ (Neither gathered
Δ (Mouth feel after
mold nor emitted
cooled was rough
offensive smell
Comp.
18.7
14.2
125.5
29
X (Emitted
◯
Ex. 1
fermentation odor)
Comp.
36.9
24.3
108
79
X (Gathered mold
X (Kernels collapsed
Ex. 2
after 3 days, and
and had sticky feel.
emitted offensive
Had dry mouth feel
smell)
after cooled, and
emitted sugary odor)
Comp.
9.5
25.2
145
6
◯ (Neither gathered
X (Kernels collapsed
Ex. 3
mold nor emitted
and had sticky feel.
foreign odor)
Liable to become
hard after cooled)
Comp.
14.2
51
120.6
15
◯ (Neither gathered
X (Kernels has no
Ex. 4
mold nor emitted
grain feel and gave
offensive smell)
no eaten feel. Had
sticky feel)
Ex. 5
10
29
143
9
◯ (Neither gathered
Δ (Kernels has no
mold nor emitted
grain feel and gave
offensive smell)
no eaten feel. Had
sticky feel)
Ex. 6
18
11.2
108
22
◯ (Neither gathered
Δ (Hard in kernels,
mold nor emitted
and poor in mouth
offensive smell)
feel after cooled)
EXAMPLE 7
Raw brown rice (Hinohikari, trade name; from Kagawa) was immersed for 16 hours in hot water of 30° C. to be germinated. Thereafter, the thus-treated brown rice was steamed at 98° C. for 3 minutes, immediately subjected to fluidized bed drying at 100° C. for 20 minutes, and then cooled for 20 minutes by ventilation to obtain germinated brown rice the water content of which was controlled to 17% by mass.
EXAMPLE 8
Raw brown rice (Koshihikari, trade name; from Kagawa) was immersed for 5 hours in hot water of 30° C., dewatered and then left at rest at room temperature for 10 hours to be germinated. Thereafter, the thus-treated brown rice was steamed at 120° C. for 3 minutes in a ribbon agitated dryer (indirect drying type), and then subjected to fluidized bed drying at 100° C. for 20 minutes to obtain germinated brown rice the water content of which was controlled to 16% by mass.
EXAMPLE 9
Raw brown rice (Koshihikari, trade name; from Nagano) was immersed for 24 hours in hot water of 30° C. to be germinated. Thereafter, the thus-treated brown rice was steamed at 98° C. for 5 minutes, and then subjected to fluidized bed drying at 80° C. for 20 minutes to obtain germinated brown rice the water content of which was controlled to 15% by mass.
EXAMPLE 10
Raw brown rice (Akitakomachi, trade name; from Akita) was immersed for 24 hours in hot water of 30° C. to be germinated. Thereafter, the thus-treated brown rice was treated with superheated steam of 170° C. for 90 seconds, and then dried for 2 hours by ventilation to obtain germinated brown rice the water content of which was controlled to 15% by mass.
EXAMPLE 11
Raw brown rice (Hinohikari, trade name; from Kagawa) was immersed for 24 hours in hot water of 30° C. to be germinated. Thereafter, the thus-treated brown rice was steamed at 98° C. for 30 minutes, cooled and then subjected to fluidized bed drying at 80° C. for 20 minutes to obtain germinated brown rice the water content of which was controlled to 14% by mass.
COMPARATIVE EXAMPLE 5
Raw brown rice (Hinohikari, trade name; from Kagawa) was immersed for 16 hours in hot water of 30° C. to be germinated. Thereafter, the thus-treated brown rice was steamed at 98° C. for 3 minutes, immediately subjected to fluidized bed drying at 100° C. for 20 minutes, and then cooled for 20 minutes by ventilation to obtain germinated brown rice the water content of which was controlled to 20% by mass.
COMPARATIVE EXAMPLE 6
Raw brown rice (Koshihikari, trade name; from Kagawa) was washed by a rice washer and immersed for 24 hours in water controlled to a constant temperature of 30° C. to be germinated. Thereafter, the thus-treated brown rice was steamed at 98° C. for 20 minutes and cooled to obtain germinated brown rice the water content of which was controlled to 37% by mass.
COMPARATIVE EXAMPLE 7
Raw brown rice (Koshihikari, trade name; from Nagano) was washed by a rice washer and immersed for 24 hours in water controlled to a constant temperature of 30° C. to be germinated. Thereafter, the thus-treated brown rice was steamed at 98° C. for 20 minutes, cooled and then subjected to fluidized bed drying at 80° C. for 20 minutes to obtain germinated brown rice the water content of which was controlled to 9.5% by mass.
COMPARATIVE EXAMPLE 8
Raw brown rice (Akitakomachi, trade name; from Akita) was immersed for 24 hours in water controlled to a constant temperature of 30° C. to be germinated. Thereafter, the thus-treated brown rice was steamed at 98° C. for 40 minutes, cooled and then subjected to fluidized bed drying at 80° C. for 30 minutes to obtain germinated brown rice the water content of which was controlled to 10% by mass.
The water contents and degree of gelatinization of the germinated brown rices obtained in Examples 7 to 11 and Comparative Examples 5 to 8, and the results of an panel test (mouth feel: roughness, glutinousness, smell) and a shelf-life stability test are shown collectively in Table 2. The degree of gelatinization was determined by using a germinated brown rice sample after 1 week from the production of the germinated brown rice as a subject in accordance with the β-amylase.pllulanase method (BAP method). The water content was analyzed by a method using near infrared rays.
The shelf-life stability was evaluated by heat sterilizing a sample, placing the sample into a polyvinylchloride bag with a zipper and leaving the sample to stand for 1 month. Whether the appearance of the sample was changed or not and offensive smell was emitted or not was confirmed, and the sample was ranked as ∘ where no problem arose (good), or × where a problem arose.
The panel test was conducted by blending each of the germinated brown rice samples with milled rice (Koshihikari, trade name; from Kagawa) in a proportion of 1 to 1 and cooking the resultant blend by an electric rice cooker in immersion time of 30 minutes with water 1.5 times as much as the sample added thereto. The evaluation was made by having 9 panelists (20 to 50 years of old) eat the cooked blend sample right after the boiling to rank the sample in accordance with the following standard:
⊚: Very delicious;
∘: Delicious;
Δ: Rather delicious.
×: Unpalatable.
The finish of each germinated brown rice sample after the drying was visually tested to rank it in accordance with the following standard:
TABLE 2
Degree of
Water Content
gelatini-
Organoleptic
Shelf stability (room
(% by mass)
zation
test
temperature, 1 month)
Finish after drying
Ex. 7
17
22.3
⊚
◯ (Neither gathered mold nor
⊚
emitted offensive smell)
Ex. 8
16
14.4
⊚
◯ (Neither gathered mold nor
⊚
emitted offensive smell)
Ex. 9
15
11.5
◯
◯ (Neither gathered mold nor
⊚
emitted offensive smell)
Ex. 10
15
34.2
Δ
◯ (Neither gathered mold nor
⊚
emitted offensive smell)
Ex. 11
14
42.6
◯
◯ (Neither gathered mold nor
⊚
emitted offensive smell)
Comp.
20
13
X
X (Gathered mold)
X
Ex. 5
Comp.
37
22.8
⊚
◯ (Gathered mold and emitted
⊚
Ex. 6
offensive smell)
Comp.
9.5
24
◯
◯ (Neither gathered mold nor
X
Ex. 7
emitted offensive smell)
Comp.
10
50.6
X
◯ (Neither gathered mold nor
◯
Ex. 8
emitted offensive smell)
⊚ : The incidence of broken rice was within 10%, and the kernels thereof had high transparency and were glossy;
◯ : The incidence of broken rice was within 20%, and the kernels thereof had high transparency;
Δ : The incidence of broken rice was conspicuous, and the kernels thereof were whitish;
X : The incidence of broken rice was very conspicuous, and the kernels thereof were whitish. | The invention relates to germinated brown rice which can be easily and deliciously boiled even by a household rice cooker without impairing its original nutritive value, and has excellent mouth feel and shelf stability. The germinated brown rice can be provided by subjecting germinated brown rice to a heat-moisture treatment and drying the treated germinated brown rice to a water content of 10 to 18% by mass and a degree of gelatinization of 5 to 50%. | 0 |
This application is a national stage completion of PCT/EP2005/000485 filed Jan. 19, 2005 which claims priority from German Application Serial No. 10 2004 006 722.8 filed Feb. 11, 2004 and German Application Serial No. 10 2004 023 341.1 filed May 12, 2004.
FIELD OF THE INVENTION
The invention concerns the steering and drive wheel for an industrial truck.
BACKGROUND OF THE INVENTION
A controllable drive wheel for an industrial truck with two drive gears is known from the DE 41 10 792 C2. A miter gear with two miter wheel gears is arranged such that a respective output spindle drives the drive gears. The miter gear is driven by an electrical drive motor on a planetary gear that is arranged parallel or co-axial to the central axis of the device. Furthermore, a steer wheel motor is provided and is mounted outside the wheel gear case directly on the chassis of the industrial truck or on an additionally arranged head, plate torque proof to the chassis. With the operation of this steer wheel motor, this turns on a steer gear stage the wheel gear case or the gear carrier in its rotating assembly journal and thus also the wheel gear with both the wheel drives at the steering axle. The disadvantage of this steerable wheel drive is that the lateral arrangement of at least the steer drive motor makes the entire device less compact.
In addition, DE 199 04 552 A1 shows a wheel drive for an industrial truck for which an electrical traction motor and a gear driven by this are arranged co-axial to the longitudinal axis of the hub of the wheel of rotor. The traction motor is thereby designed as an electric motor with a disc-shaped rotor. Furthermore, the wheel drive exhibits electromotor steering with a steer motor and a steer gear, by which the steer motor is necessarily arranged perpendicular to the stage and is mounted by the turning of the rotor by the entire longitudinal axle of the wheel hub, traction motor and gear. The steer gear is a Wolfram-gear.
Although this wheel drive is very compact in the entire device, through the mentioned wheel hub drive as well as integration of the steer motor and the steer gear, its constructive formation, especially due to the cramped measure in the area of the wheel hub is comparatively complex and, therefore, costly. A further disadvantage is considered that the revealed combination of traction motor and gear, as well as steer motor and steer gear, develops a relatively large diameter size wheel drive.
Against this background, the task underlying the invention is to manage a constructively simple electro-motor steering and driving system for an industrial truck that exhibits a small diameter compared to known steering and driving systems and which could be manufactured at a comparatively cheaper cost with an acceptable design.
SUMMARY OF THE INVENTION
The invention concerns a steering and driving for an industrial truck with a driving engine, a traction motor, a steering engine and a steering transmission, through which at least a rotor arranged on a wheel hub of an industrial truck is drivable and is rotatable at a vertical axis. It is important with this steering and driving system that the traction motor, steering engine and the steering transmission are arranged co-axial to each other. Thereby, with an acceptable installation height, an especially radial compact design results as well as through the increased integration grade, for example, the double usage of housing components, at a comparatively lower manufacturing cost.
An especially preferred embodiment of the invention thereby provides that the driving engine, the steering engine and the steering transmission are arranged axially in this sequence, one after another, while the driving transmission, formed as a miter gear, is linked with a rotating assembly driven by a steering engine on the steering transmission and is arranged axially behind the steering transmission.
In a further constructive training of the specified design principle, it is considered that the driving engine is formed as a solid shaft and the steering engine shaft as a hollow shaft, as well as that the traction motor is led co-axially through the steering motor shaft.
Furthermore, it is considered that the traction motor carries a spur-wheel on its further end from the traction motor, which is there in tooth engagement with a spur-wheel on the input shaft of the traction gear, formed as a miter gear. The output shaft of this motor gear is linked with a wheel hub of at least a rotor.
In a further design of the invention, the steering transmission is designed as a multi-leveled planetary gears and/or a Wolfram-gear, whereby the latter exhibits an advantage due to its axially shorter length with higher gear reduction.
Furthermore, the invention concerns the drive-technical link between the steering engine and the steering transmission, as well as between the steering transmission and the swivel drive of the driving transmission or of a rotor at least linked with the latter. In this context, it is considered that the steering engine shaft is designed as the first sun wheel, whose external tooth system is in tooth engagement with the teeth of planetary wheels of the steering transmissions.
With the usage of multi-leveled planetary gears as steering transmission, it is preferably considered that the planetary wheels of the first planetary wheel are level with the first mentioned sun wheel and are stored on a first planetary carrier, which is linked slip free with a second sun wheel. On this second planetary carrier, rotary stored planetary wheels of the second planet wheel stage are meshed with the external tooth system of the second sun wheels, whereby the planet wheels of the first and the second planet wheel level are located in tooth engagement with a fixed hollow wheel or two fixed hollow wheels. Additionally, it is considered that the second planetary carrier is linked slip free with a third sun wheel, that the third sun wheel is in tooth engagement with planet wheels of the third planet wheel stage, that the planet wheels of the third planet wheel stage are stored rotating on a third planetary carrier, which is linked slip free with the hollow wheel and that the planet wheels of the third planet wheel set is in tooth engagement with an internal tooth system of the journal internal ring of rotary assembly journal, which is linked slip free with the rotary assembly or directly with the housing of the traction gear.
Another detail of the invention is thereby indicated that the journal external ring of rotary assembly journal is slip free linked with a vehicle framework of an industrial truck.
It could be further considered that the housing of the steering engine is held on with the fastener axially on the journal outer ring. Further, the compact design of this steering and driving system thereby prefers that the specified hollow wheel and the radial external end of third planetary carrier are arranged between the external wall of the steering engine housing and the journal external ring, behind each other. In this manner, the steering engine housing can be fixed against the journal external ring of rotary assembly by the mentioned fastener that are simultaneously linked as a hollow wheel affecting as a steering transmission housing as well as the third planetary carrier axially with each other.
In addition, it can be planned in a deviation that the steering transmission housing is fixed slip free on the separate fastener on the journal external ring of rotary assembly.
A preferred variation of the invention is thereby given, that a brake is arranged affecting the driving engine shaft on the driving transmission's farther end of the steering and driving system. This brake is preferably designed as electrically activated, while it is considered possible regarding the steering engine to design this as an electric motor with a disc-shaped rotor.
Further, it could be considered that the housing of the driving engine is fixed on the housing of the driving engine or an entire housing is used by both the engine elements. This housing and/or the single housing is designed as a sheet construction.
Additionally, it is profitably assessed if the steering transmission housing, the journal external ring of rotary assembly or the rotary assembly exhibits a bore for recording by swiveling angle sensors; with its help the swiveling of the rotor is ascertainable at its steering axle and is communicated to a control device.
Regarding the recording of the steering angle for usage in a control device allocated to the steering and driving system, it can be considered on the rotor of the steering engine, on the fixed journal outer ring of the rotary assembly and/or on the rotary assembly signal indicator as a magnet, which interacts together with the specified swiveling angle sensors for swiveling angle detection.
As per another aspect of the invention, it is considered that a flange, pointing radially outward, especially a ring flange, is formed on the steering transmission housing as well as on the steering engine housing, respectively, through which respective axial bores, fixing screws are fed for fixing the same on the journal external ring.
Such an example, with one or all the specified features of highly integrated steering and driving system, as a further advantage, exhibits reduced noise pressure, especially at the time of changing the pressure, and has low maintenance and/or is maintenance free, because the steering transmission could be filled with a lifetime lubricant, and also the steering engine can be of a maintenance free design by using a brushless dc motor or alternating current motor in standard or shrunk-on-disc design.
For the reduction of manufacturing costs, it is further advised to design the planetary carrier as a sheet construction with an open or closed design.
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 partial section represented with a lateral view of an electromotor steering and driving system for an industrial truck, and
FIG. 2 is a representation as in FIG. 1 , however related to a second design example of the invention.
DETAILED DESCRIPTION OF THE INVENTION
According to FIG. 1 , a steering and driving system 1 designed according to the invention, as the main component, an industrial truck (of vehicle) initially has a driving engine (traction motor) 2 , by which a driving shaft (traction motor shaft) 3 is driven on a driving transmission (traction gear) 21 of a rotor 23 . The rotor 23 is rotatable, together with the driving transmission 21 , along a vertical axis V. For the execution of this swivel movement, the steering and driving system 1 allotted on an electric steering engine (steering motor) 4 , on which a steering transmission (steering gear) 5 is arranged. For gear reduction of the steer motor revolution, the output of this steering transmission gear 5 affects a rotary assembly 27 that is linked slip free with a housing 51 of driving transmission 21 . Particularly, it is of importance for the steering and driving system 1 designed according to the invention that the driving engine 2 , the steering engine 4 and the steering transmission 5 are arranged co-axial with each other.
In detail, this steering and driving system 1 is designed in such a manner that the driving engine shaft 3 is a solid shaft and is fed through a hollow shaft placed by a steering engine shaft (steering motor shaft) 9 . A first spur-wheel 19 is fixed on the driving engine shaft 3 on the far end its traction motor, which meshes with a second spur-wheel 20 that is on a gearbox input shaft of the driving transmission (traction gear) 21 (not shown here). In this traction gear, the drive torque is managed in the known manner on an angle drive to a gear output shaft that is linked slip free with a wheel hub 22 . The rotor 23 is fixed on this wheel hub 22 with screws.
Further, a brake 42 is fixed on the traction motor housing above driving engine 2 co-axial to the vertical axis V which affects the driving engine shaft 3 if required and is particularly activated with elasticity and is electrically ventilated.
The steering engine 4 is designed here as a shrunk-on-disk rotor and is available on a stator 6 and a rotor 7 , which are placed in a steering engine housing 8 , 8 ′. Thereby the stator 6 is linked on a fixing element which not indicated further with the steering engine housing 8 , 8 ′, while the rotor 7 is fixed on the already-mentioned steering engine shaft 9 .
As represented in FIG. 1 on left of vertical axis V, the gear housing of the driving engine 2 can be fixed on the steering engine housing 8 by way of fixation screws 28 , while the right figure half could be extracted from the deviating design, for which the steering engine 4 and the driving engine 2 display a total housing 8 ′.
Further, FIG. 1 shows that the driving engine far side of steering engine 4 is covered by a cap 47 , which is clamped axially between the housing 8 , 8 ′ of steering engine 2 and a hollow wheel 16 serving as a housing element.
The steering engine shaft 9 is on a roller bearing 30 , 31 on which the cap 47 , serving as a bearing shield, and on the housing 8 , 8 ′ of steering and driving is supported revolving as well as packed on seal. It serves in a technical multi-level planetary steering transmission 5 as first sun wheel on the steering engine 4 drive. The outer teeth of this first sun wheel 9 meshes thereby with the teeth of planet wheels 10 of the first planetary wheel stage that are supported revolving on a first planetary carrier 11 . This first planetary carrier 11 is linked slip free with a second sun wheel 13 which axially connects to the spur wheel 19 on the first sun wheel 9 (steering engine shaft 9 ).
The outer teeth of the second sun wheel 13 are engaged with teeth of the planet wheels 12 of the second planet stage, which is supported revolving on a second planetary carrier 14 . Thereby the planet wheels 10 , 12 of the first and the second planet wheel stage is engaged with the fixed hollow wheel 16 .
The second planetary carrier 14 is linked slip free with a third sun wheel 15 which meshes with planet wheels 17 of the third planet wheel stage. This planet wheel 17 of the third planet wheel stage is revolving supported on a third planetary carrier 18 , which is linked slip free with the mentioned hollow wheel 16 .
Eventually the planetary carrier 18 of the third planet wheel set stands effectively engaged with the inner teeth of a bearing inner ring 25 of a rotary assembly 24 , which is linked slip free on a fixation screw 44 with the rotary assembly 27 . An outer ring 50 as well as a rolling element 29 , enclosed between the rings 25 , 50 belong to the rotary assembly 24 .
Further, it is seen in FIG. 1 that preferably the traction gear housing 51 is linked slip free by fixation screws 46 with the rotary assembly 27 . Furthermore, this representation clarifies that the driving engine shaft 3 is supported above the spur-wheel 19 on a roller bearing 48 with the rotary assembly 24 and below the same on a roller bearing 49 in the traction gear housing 51 .
The outer ring 50 of the rotary assembly 24 is firmly combinable with the chassis C of the industrial truck whereby in this outer ring 50 , a bore 26 is designed with a screw thread, in which a fixation screw is screwed in, meshing these two parts.
Finally, FIG. 1 shows that on housing 8 of steering engine 4 , an outward radial flange 52 , that can be built from one or more plates, is arranged, fastened by a fixation screw 37 led through its axial bore. The thread section of the fixation screw 37 is screwed in a thread in the outer ring 50 of rotary assembly 24 , 50 that the housing 8 ′ of steering engine is ascertained with the hollow wheel 16 serving as housing section and the third planetary carrier 18 as well as the cap 47 axial against the bearing outer ring 50 and thus against the chassis C of the industrial truck.
The design represented in FIG. 2 of two further variations of the invention formed steering and driving system 53 , 54 differs from the steering and driving system 1 , represented in FIG. 1 , in that the steering transmission is designed as a Wolfram-gear 32 , 32 ′ and not as a multi-level planet gear.
Also for both these design forms the steering engine shaft (steering motor shaft) 55 serves as sun wheel and carries an outer gearing which is engaged with the teeth of planet wheels 33 and/or 35 . For the second design variations, right near the vertical axis V, the planet wheels 33 are supported slip free on a planetary carrier 34 and are additionally engaged with an inner gearing on an inward radial section of a steering transmission housing 43 . Further, the planetary carrier 34 meshes with the inner gearing of inner ring 25 of the rotary assembly 24 already known from FIG. 1 , so that the rotary assembly 27 is rotatable at the vertical axis V by the steering engine 4 .
A hollow wheel 36 is thereby fixed or integrated with it on the radial inward projecting section of the steering transmission housing 43 , which is ascertained by way of fixation screws 45 on the outer ring 50 of the rotary assembly 24 .
As shown in FIG. 2 to the right of the vertical axis V, it is preferable if the fixation screws 45 penetrate the flange 52 of steering engine housing 8 as well as also a bore in flange 58 on steering transmission housing 43 so that, in this manner, both the upper engine elements 2 , 4 are centered to the steering transmission housing 43 and are ascertained against the bearing outer ring 50 of the rotary assembly 24 .
At the left of the vertical axis V, a third variation represents the planet wheels 35 of Wolfram-steer transmission 32 ′ display geometry as the aforementioned planet wheels 33 . Thereby it is especially striking that this exhibits the designed rotating axis on the planet wheels 33 and not the bore for recording of rotating axis of planet wheels 33 . This intervenes in the recording opening of visible planetary carrier.
In addition, in FIG. 2 it can be seen that the axial short forming steering transmission 32 ′ exhibits the hollow wheel 36 , with which the planet wheel 35 is engaged. This hollow wheel 36 is linked slip free or integrated with an inward radial section of steering transmission housing 43 . The steering transmission housing 43 is clamped on the sides under the interlayer of the cap and/or the bearing shield 47 of steering engine 4 between its housing 8 and the outer ring 50 of rotary assembly 24 .
Finally, FIG. 2 shows that in the steering and driving system 32 , 32 ′, sensors 38 , 40 can be installed with which the rotation of rotary assembly 27 is identifiable against the lying drive elements.
In the case of the second variation of the steering and driving system 32 , this angle of rotation 40 is inserted in a recording opening 41 of an inward radial and section 57 serving as a bearing shield of combined housing 8 ′ by the driving and steering engines and measures the named swivel movement on the rotor 7 of the steering engine 4 .
For the third variation of the steering and driving system 32 ′ (left near the vertical axis V represented), the sensor 38 is inserted in a recording opening 39 in the outer ring 50 of rotary assembly 24 . In this case, the swivel between the outer ring 50 and the rotary assembly 27 is ascertained and informed to a control device (not shown here).
REFERENCE NUMERALS
1 steering and driving system
2 driving engine
3 driving engine shaft
4 steering engine
5 steering transmission
6 stator steer motor
7 rotor steer motor
8 steering engine housing
9 steering engine shaft; first sun wheel
10 planet wheel of first planet wheel stage
11 first planetary carrier
12 planet wheel of second planet wheel stage
13 second sun wheel
14 second planetary carrier
15 third sun wheel
16 hollow wheel
17 planet wheel of third planet wheel stage
18 third planetary carrier
19 spur-wheel
20 spur-wheel
21 driving transmission
22 wheel hub
23 rotor
24 rotary assembly
25 bearing inner ring with inner wheel teeth
26 bore
27 rotary assembly
28 fixation screw
29 rolling element
30 roller bearing
31 roller bearing
32 Wolfram-steer transmission (variation 2)
32 ′ Wolfram-steer transmission (variation 3)
33 planet wheel of Wolfram-steer transmission (variation 2)
34 planet carrier of Wolfram-steer transmission
35 planet wheel of Wolfram-steer transmission (variation 3)
36 hollow wheel of Wolfram-steer transmission
37 fixation screw
38 angle of rotation sensor
39 recording opening in outer ring of rotary assembly bearing
40 angle of rotation sensor
41 recording opening in housing section 57
42 brake
43 housing Wolfram-gear (variation 2)
44 fixation screw
45 fixation screw
46 fixation screw
47 cap of steer gear
48 roller bearing
49 roller bearing
50 outer ring of rotary assembly
51 housing of traction gear
52 flange on housing 8
53 steering and driving system
54 steering and driving system
55 steering engine motor shaft for Wolfram-gear
57 housing section on housing 8 ′
58 plate or flange on steering transmission housing 43
V vertical axis | A steering and driving system ( 1, 53, 54 ) for an industrial truck with a driving engine ( 2 ), a driving transmission ( 21 ), a steering engine ( 4 ) and a steering transmission ( 5, 32, 32′ ), through that one rotor ( 23 ) arranged on a wheel hub ( 22 ) could be driven and is swivelable at a vertical axis (V). For the realization of the compact design form as well as lesser manufacturing costs for this steering and driving system is considered, that the driving engine ( 2 ), the steering engine ( 4 ) and the steering transmission ( 5, 32, 32′ ) are arranged co-axially to each other. | 2 |
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