description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
|---|---|---|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a vaccine prepared from Mycoplasma hyorhinis isolated from the lung lesions of pigs infected with enzootic pneumonia and the application of the foregoing vaccine.
[0003] 2. Description of Related Art
[0004] Swine enzootic pneumonia is a chronic disease characterized by high infection rate and low mortality that infects 25˜93% of swine herds and is positive in 28˜80% of lung tissues of carcasses. The growth efficiency of infected pigs is reduced by 14˜16%. In high-density rearing environment that is poorly ventilated and moist with wildly changing climate, the incidence and spread of swine enzootic pneumonia can rise to an alarming level, resulting in lower feed conversion, regarded growth, inflammatory reaction and immunosuppression in pigs. This disease is often accompanied by secondary infection of opportunistic pathogens, such as Actinobacillus pleuropneumoniae, Pasteurella , and Streptococcus suis , leading to serious economic loss and becoming one of important reasons for the cost increase of the pig industry.
[0005] The strategic approach to the prevention of swine enzootic pneumonia in Taiwan is to add antibiotic in the feed. But long-term use of antibiotic is prone to produce resistant strains and leads to the problem of residual antibiotic in the meat products, which poses significant health issue. Field experience also shows the preventive effect of feeding animals with drugs is not as ideal as expected.
[0006] There are three commonly seen mycoplasma in pigs, which are Mycoplasma hyopneumoniae ( M. hyopneumoniae ), Mycoplasma hyorhinis ( M. hyorhinis ), and M. flocculate. M. hyopneumoniae is the important causative organism of swine enzootic pneumonia (SEP); M. hyorhinis is the etiological agent of polyserositis and arthritis; M. flocculate has not been shown to cause diseases. In the past, all SEP incidences were caused by M. hyopneumoniae . But recently it is found that such disease is caused by either M. hyorhinis alone or the combination of M. hyorhinis and M. hyopneumoniae . In Taiwan, mycoplasma isolated from the lung lesions of pigs infected with SEP was only M. hyopneumoniae prior to 1996. In the case reports in other countries, M. hyorhinis was primarily isolated from the synovial fluid of pigs infected with arthritis, which did not cause SEP and was not considered an important pathogen for swine diseases. Taiwan never isolated this pathogen in the past. But starting in 1996, the Mycoplasma Laboratory of Animal Technology Institute Taiwan finds mycoplasma isolated from the lung lesions of pneumonia-infected pigs to be M. hyorhinis in more incidences as confirmed by antibody binding reaction using Western blotting and comparison with ATCC standard strains.
[0007] The Animal Technology Institute Taiwan provides mycoplasma isolation and identification service to pig farms around the country, and sees higher and higher incidence of M. hyorhinis isolates from pneumonia cases. In the 242 cases in 2001 and 205 cases in 2002, the M. hyopneumoniae infection rate dropped from 46.8% in 2001 to 15.8% in 2002, while that of M. hyorhinis rose from 65.5% in 2001 to 79.2% in 2002. The infection rate of the mixture of M. hyopneumoniae and M. hyorhinis was 14.4% in 2001 and 15% in 2002. These figures indicate rapidly rising M. hyorhinis infection in swine pneumonia cases in Taiwan and rapidly dropping infection rate of M. hyopneumoniae , while infection rate of the mixture of the two remains steady. It also indicates that M. hyorhinis is gradually replacing M. hyopneumoniae as the most significant pathogen of SEP. The past belief was that M. hyopneumoniae was the only species among mycoplasma to cause SEP. This is not the situation now. In the isolation cases described above, there was one pure M. hyorhinis infection case in 2001, and five such cases in 2002, suggesting M. hyorhinis alone could elicit SEP.
[0008] Field experience shows that the chance of reinfection with the same mycoplasma species is relatively low, indicating good innate immunity of the pigs against such pathogen. Thus using vaccination as a means of disease prevention is a viable approach. Given the weak cross reaction between the antigens of M. hyorhinis and M. hyopneumoniae , it is found in pig farm survey on vaccination that pigs administered with M. hyopneumoniae vaccine were not effectively protected against the infection of M. hyorhinis . For pigs infected with both mycoplasma species, the effect of administering M. hyopneumoniae vaccine or M. hyorhinis vaccine alone was not satisfactory. Only vaccine containing the mixture of both mycoplasma antigens provides adequate protection. Thus developing vaccine containing M. hyorhinis or both M. hyorhinis and M. hyopneumoniae is a pressing task.
SUMMARY OF THE INVENTION
[0009] For the prevention of swine enzootic pneumonia, the present invention provides a mycoplasma vaccine, comprising at least an effective amount of inactivated M. hyorhinis ATIT-7. The foregoing M. hyorhinis has been preserved at the Culture Collection and Research Center of the Food Industry Research and Development Institute (No. BCRC910223) since May 8, 2003. Besides containing M. hyorhinis ATIT-7, the foregoing mycoplasma vaccine may further include an effective amount of inactivated M. hyopneumoniae , wherein the concentration of M. hyopneumoniae in the vaccine is 60˜80% v/v and that of M. hyorhinis ATIT-7 is 40˜20% v/v.
[0010] The mycoplasma vaccine may further contain an adjuvant or diluent, wherein the inactivated mycoplasma fluid (containing only M. hyorhinis ATIT-7 or the mixture of M. hyorhinis ATIT-7 and M. hyopneumoniae ) comprises 50˜75% v/v of the vaccine composition, and the adjuvant comprises 50˜25% v/v.
[0011] The mycoplasma vaccine may be administered subcutaneously or intramuscularly to the animal.
[0012] The M. hyorhinis ATIT-7 is cultured until its O.D. 550 reaches the level of 0.14 to 0.33, and M. hyopneumoniae is cultured until its O.D. 550 reaches the level of 0.08 to 0.16.
[0013] The present invention also relates to a method for the preparation of mycoplasma vaccine, comprising the steps of: culturing M. hyorhinis ATIT-7 in vaccine culture medium; inactivating the harvested M. hyorhinis ATIT-7 with formalin; and letting the culture stand under 2-8° C. to continue the inactivation for 16 to 72 hours. M. hyorhinis ATIT-7 is cultured until its O.D. 550 reaches the level of 0.14 to 0.33 with viable count of higher than 10 9 CCU/mL. The concentration of said formalin is preferably between 0.1 and 0.5%, and more preferably between 0.1 to 0.2%.
[0014] The vaccine culture medium for cultivating M. hyorhinis comprises 500 ml of Hank's solution, 12,000 ml of distilled water, 82 g of Bacto brain heart infusion (Difco), 87 g of Bacto PPLO broth, 600 ml of yeast extract, 45 ml of phenol red, 2.5 g of bacitracin, 2.5 g of penicillin or methicillin, and 1,500 to 5,000 g of inactivated porcine serum or inactivated horse serum.
[0015] The method for preparing M. hyorhinis vaccine can further contain the steps of: culturing M. hyopneumoniae in a vaccine culture medium; inactivating harvested culture fluid with formalin; and letting the culture stand under 2-8° C. to continue the inactivation for 16 to 72 hours; admixing the resulting inactivated M. hyopneumoniae with aforesaid inactivated M. hyorhinis . The concentration of said formalin is preferably between 0.1 and 0.5%, more preferably between 0.1 to 0.2%. M. hyopneumoniae is cultured until its O.D. 550 reaches the level of 0.08 to 0.16 with viable count of higher than 10 9 CCU/mL.
[0016] The vaccine culture medium for cultivating M. hyopneumoniae comprises 500 ml of Hank's solution, 12,000 ml of distilled water, 82 g of Bacto brain heart infusion (Difco), 87 g of Bacto PPLO broth, 600 ml of yeast extract, 45 ml of phenol red, 2.5 g of bacitracin, 2.5 g of penicillin or methicillin, and 1,500 to 5,000 g of inactivated porcine serum.
[0017] The present invention further provides a pharmaceutical composition for the prevention of mycoplasma infection, comprising an effective amount of the aforesaid mycoplasma vaccine and a pharmaceutically acceptable carrier.
[0018] The present invention also relates to a M. hyorhinis strain ATIT-7 capable of infecting swine and causing pneumonia, wherein said strain has been preserved at the Culture Collection and Research Center of the Food Industry Research and Development Institute (No. BCRC 910223) since May 8, 2003.
[0019] The present invention also provides a strain collection method, comprising the steps of: isolating M. hyorhinis strain ATIT-7 from the lung lesions of pigs infected with pneumonia; culturing said strain in culture medium under 35˜38° C. for 16 to 24 hours to obtain viable organism count of higher than 10 9 CCU/mL. The culture medium for cultivating M. hyopneumoniae comprises 500 ml of Hank's solution, 12,000 ml of distilled water, 82 g of Bacto brain heart infusion (Difco), 87 g of Bacto PPLO broth, 600 ml of yeast extract, 45 ml of phenol red, 2.5 g of bacitracin, 2.5 g of penicillin or methicillin, and 1,500 to 5,000 g of inactivated porcine serum or inactivated horse serum.
[0020] The M. hyorhinis strain ATIT-7 has been preserved at the Culture Collection and Research Center of the Food Industry Research and Development Institute (No. BCRC 910223) since May 8, 2003.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1A shows the production of M. hyorhinis antibody in mice vaccinated with M. hyorhinis bacterin and bacterin containing the mixture of M. hyorhinis and M. hyopneumoniae.
[0022] FIG. 1B shows the production of M. hyopneumoniae antibody in mice vaccinated with M. hyorhinis bacterin and bacterin containing the mixture of M. hyorhinis and M. hyopneumoniae.
[0023] FIG. 2A shows the production of M. hyorhinis antibody in piglets vaccinated with M. hyorhinis bacterin and bacterin containing the mixture of M. hyorhinis and M. hyopneumoniae on days 1, 15, and day 29 respectively.
[0024] FIG. 2B shows the production of M. hyopneumoniae antibody in piglets vaccinated with M. hyorhinis bacterin and bacterin containing the mixture of M. hyorhinis and M. hyopneumoniae on days 1, 15, and day 29 respectively.
[0025] FIG. 3 observes the pathological changes of the lungs of piglets following immunoresistance test, in which A, B, C, D represents Group 1, 2, 3, and 4 respectively; Group 1 was vaccinated with M. hyorhinis bacterin and challenged with virulent M. hyorhinis ; Group 2 was vaccinated with M. hyorhinis+M. hyopneumoniae bacterin and challenged with virulent M. hyorhinis and M. hyopneumoniae ; Group 3 was not vaccinated but challenged with virulent M. hyorhinis ; and Group 4 was not vaccinated and not challenged with mycoplasma.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The features and advantages of the present invention are further depicted with the illustration of examples.
EXAMPLE
Preparation of Vaccine
[heading-0027] 1. Vaccine Strain
[0028] PRIT-5 is a M. hyopneumoniae strain disclosed in another Taiwanese patent of the applicant filed on Apr. 24, 1990 and approved on Apr. 21, 1991. PRIT-5 strain has been preserved at the Culture Collection and Research Center of the Food Industry Research and Development Institute (No. CCRC910045) since Mar. 14, 1996. ATIT-7 is a M. hyorhinis strain isolated from lung lesions of infected pigs, which is found to proliferate very fast in culture medium; its viable count could reach over 10 9 CCU/mL after growing in culture medium under 35˜38° C. for 16 hours, while the count of other M. hyorhinis strains fell in the range of 10 8 ˜10 9 CCU/mL. The ATIT-7 strain has been preserved at the Culture Collection and Research Center of the Food Industry Research and Development Institute (No. BCRC910223) since May 8, 2003.
[heading-0029] 2. Preparation of Culture Medium
[0030] The culture medium for preparing the vaccine is formulated as follows:
Hank's solution 500 ml Distilled water 12,000 ml Bacto brain heart infusion 82 g Bacto PPLO broth 87 g Yeast extract 600 ml Phenol red 45 ml Bacitracin 2.5 g Penicillin or methicillin 2.5 g Porcine serum 1,500 to 5,000 g
[0031] (The porcine serum is first inactivated under 56° C. for 30 minutes one to two times)
[0032] The formulated culture medium has pH adjusted to 7.4˜7.6 and is then filtered with 0.2 μm Millipore.
[heading-0033] 3. Preparation of Vaccine
[0034] Culture and Treatment of M. Hyorhinis Vaccine
[0035] Let M. hyorhinis strain ATIT-7 grow in vaccine culture medium which is placed in 37° C. shaking incubator for 8-24 hours. Harvest the culture when the bacterial fluid turns yellow. Use photoelectric colorimeter to measure the O.D. 550 , which must reach 0.14 to 0.33, and the viable-organism count which must be higher than 10 9 CCU/mL. Add 0.1 to 0.2% formalin to the harvested culture. After carrying out inactivation in 37° C. shaking incubator for 1 hour, place the bacterial fluid under 2˜8° C. to continue inactivation for 16 to 72 hours. Mix the formalin-treated bacterial fluid with adjuvant (50˜75% v/v of bacterial fluid and 50˜25% v/v of formalin). Agitate the mixture with agitator for 15 minutes. The resulting vaccine is stocked under 4° C. for future use. Each dose of the vaccine is 2 ml with each ml containing about 2×10 9 ˜2×10 10 CCU.
[0036] Culture and Treatment of M. Hyorhinis and M. Hyopneumoniae Mixture Vaccine
[0037] Let strain PRIT-5 and ATIT-7 grow in vaccine culture medium which is placed in 37° C. shaking incubator for 36-72 hours (PRIT-5) and 8-24 hours (ATIT-7) respectively. Harvest the culture when the bacterial fluid turns yellow. Use photoelectric colorimeter for measurement. The O.D. 550 of PRIT-5 must reach 0.08 to 0.16, and its viable-organism count must be higher than 10 9 CCU/mL; The O.D. 550 of ATIT-7 must reach 0.14 to 0.33, and its viable-organism count must be higher than 10 9 CCU/mL.
[0038] Add 0.1 to 0.2% formalin to the harvested ATIT-7 and PRIT-5 cultures respectively. After carrying out inactivation in 37° C. shaking incubator for 1 hour, place the bacterial fluid under 2˜8° C. to continue inactivation for 16 to 72 hours. Admix the formalin-treated ATIT-7 bacterin and formalin-treated PRIT-5 bacterin by the respective ratio of 40˜20% v/v and 60˜80% v/v into a bacterin mixture.
[0039] Admix the bacterin mixture with adjuvant (50˜75% v/v of bacterin mixture and 50˜25% v/v of formalin). Agitate the mixture with agitator for 15 minutes. Each dose of the resulting vaccine is 2 ml with each ml containing about 2×10 9 ˜2×10 10 CCU.
[heading-0040] 4. Use of Vaccine
[0041] Each piglet was given two or three intramuscular injections of the prepared vaccine at one dose each time. The first dose was administered at 1-3 weeks of age; the second dose was administered at 3-5 weeks of age; the third dose was administered at 5-7 weeks of age. The vaccine must be mixed well prior to use.
[heading-0042] 5. Vaccine Safety Test
[0043] (1) Safety test in mice: Obtain 40 BALB/c mice. Randomly assign 8 mice as control group and divide the remaining 32 mice into 4 test groups with 8 mice in each group. Group 1 were subcutaneously inoculated with 0.5 ml M. hyorhinis vaccine; Group 2 was subcutaneously inoculated with 0.5 ml mixture vaccine (mixture of M. hyorhinis and M. hyopneumoniae bacterins); Group 3 received intraperitoneal inoculation of 0.5 ml M. hyorhinis vaccine; and Group 4 received intraperitoneal inoculation of 0.5 ml mixture vaccine. The mice were observed for 14 days after vaccination. All mice survived and no adverse reaction was observed.
[0044] (2) Safety test in piglets: Pick 15 one-week old piglets. Randomly divide the piglets into 5 groups with 3 heads per group. Group 1 was administered with one dose of M. hyorhinis vaccine intramuscularly on the side of neck; Group 2 received 5 doses of M. hyorhinis vaccine intramuscularly on the side of neck; Group 3 was vaccinated with 1 dose of mixture vaccine intramuscularly on the side of neck; and Group 4 received 5 doses of mixture vaccine intramuscularly on the side of neck. All piglets survived and no adverse reaction was observed in subsequent 14 days of observation period.
[heading-0045] 6. Vaccine Efficacy Test
[0046] (1) Antibody titer assay in mice: Obtain 30 four-week old BALB/c female mice. Randomly divide them into 3 groups with 10 mice in each group. Group 1 and Group 2 were subcutaneously vaccinated twice with M. hyorhinis vaccine and mixture vaccine respectively. Group 3 was the control group. In one week after the second vaccination, blood was collected from eye orbit under anesthesia. The collected blood was placed under room temperature for 1 hour and then placed under 4° C. overnight. The blood was then centrifuged under 1107×g for 30 minutes. After centrifugation, supernatant was removed, placed in a new centrifuge tube, and then subject to ELISA immunoassay. The results are as shown in FIG. 1 . FIG. 1A shows the level of M. hyorhinis antibody produced in mice vaccinated with M. hyorhinis vaccine (Group 1) and mixture vaccine (Group 2); FIG. 1B shows the level of M. hyopneumoniae antibody in mice vaccinated with mixture vaccine (Group 2). It is clear that two administrations of M. hyorhinis vaccine or M. hyorhinis - M. hyopneumoniae mixture vaccine will boost the level of serum antibody and thus enhance the pig's immune reaction.
[0047] (2) Immunoresistance test in piglets: The purpose of resistance test is to compare the immunity of vaccinated and non-vaccinated piglets against mycoplasma infection. Obtain 12 3-week old piglets which were divided into 4 groups with 3 heads each. Group 1 was vaccinated with M. hyorhinis vaccine and then challenged with virulent M. hyorhinis ; Group 2 was administered with mixture vaccine and then challenged with virulent M. hyorhinis and M. hyopneumoniae ; Group 3 (control group) was given PBS and challenged with virulent M. hyorhinis ; and Group 4 (control group) was given PBS and challenged with PBS instead of virulent mycoplasma (see Table 1). The first vaccination was given on day 1, the booster shot was given on day 15, and the challenge was carried out on day 29. The piglets were sacrificed on day 50. Blood was collected three times prior to vaccination and challenge on days 1, 15, and 29 respectively, and then subjected to ELISA immunoassay. The results are as shown in FIG. 2 . FIG. 2A shows that M. hyorhinis serum antibody was observed in both Group 1 and Group 2, and the antibody level peaked after the second vaccination (day 29). FIG. 2B shows the presence of M. hyopneumoniae serum antibody in Group 2 piglets vaccinated with mixture vaccine. Both graphs indicate rising mycoplasma serum antibodies in vaccinated piglets. After two doses of vaccines, Group 1 and Group 3 were challenged with virulent M. hyorhinis , while Group 2 was challenged with both virulent M. hyorhinis and M. hyopneumoniae , and Group 4 was challenged with PBS in place of mycoplasma as control. In three weeks after the challenge, the piglets were weighed and then euthanized and necropsied. The pathological changes of the lungs of necropsied piglets are shown in FIG. 3 . FIG. 3A shows the lung from Group 1, FIG. 3B shows the lung from Group 2, and so on. The harvested lungs had lesion count and microorganism isolation with results depicted in Table 2. The average body weight of the vaccinated group and non-vaccinated group differed by nearly 15 kg, suggesting M. hyorhinis infection significantly retarded the growth of pigs, while the vaccinated groups were not affected. Based on the observation of lung lesions in FIG. 3 and lung lesion count as depicted in Table 2, it is found that the lungs of vaccinated groups and non-challenged group (Group 4, FIG. 3D ) did not have lesions, while non-vaccinated and challenged group (Group 3, FIG. 3C ) showed typical mycoplasma pneumonia lesion (at where black arrow is pointed at) with striking difference between the two.
TABLE 1 Vaccine Efficacy Test Design No. of piglets Day 1 Day 15 Day 50 Group vaccinated vaccination vaccination Day 29 challenge necropsy 1 3 M. hyorhinis M. hyorhinis M. hyorhinis — 2 3 M. hyorhinis + M. hyorhinis + M. hyorhinis + — M. hyopneumoniae M. hyopneumoniae M. hyopneumoniae 3 3 PBS PBS M. hyorhinis — 4 3 PBS PBS PBS —
[0048]
TABLE 2
Post-challenge Growth, Lung Lesion Count and M. hyopneumoniae
isolation
Body weight (kg)
Lung
Before
Before
Before
lesion
Mycoplasma
Group
vaccination
challenge
necropsy
count
isolation
1
4.3 ± 0.1
15.1 ± 0.5
37.2 ± 3.4
0
0/3
2
4.4 ± 0.2
14.9 ± 0.3
39.8 ± 1.5
0
2/3
3
4.0 ± 0.2
13.8 ± 0.3
24.1 ± 2.3
7.3 ± 5.0
2/3
4
3.9 ± 0.2
14.2 ± 0.3
34.2 ± 1.6
0
0/3
[0049] (3) Field test: To understand the ability of vaccine of the present invention to elicit protective immunity in the field, vaccines were provided to two pig farms; one had incidence of simple M. hyorhinis infection (herds of 1,300 pigs), and the other had incidence of M. hyorhinis and M. hyopneumoniae mixed infection (herds of 4,000 pigs). After vaccination, the pig farm that had simple M. hyorhinis infection saw the number of piglet death drop from 137 heads to 50 heads and the herds survival rate rising from 89% to 96%; the pig farm that had mixed infection saw the number of piglet death drop from 525 heads to 75 heads, and the herds survival rate rising from 86% to 98%.
[0050] The embodiment of the present invention as disclosed above is not meant to limit this invention. All modifications and alterations made by those familiar with the skill without departing from the spirits of the invention and appended claims shall remain within the protected scope and claims of the invention. | The present invention provides a mycoplasma vaccine, its preparation and application thereof. The foregoing mycoplasma vaccine comprises inactivated Mycoplasma hyorhinis ATIT-7 only or the mixture of inactivated Mycoplasma hyorhinis ATIT-7 and inactivated Mycoplasma hyopneumoniae , which effectively prevents the infection of swine enzootic pneumonia in pigs. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to digital data capture circuits, and more particularly to a data capture window extension circuit having a clock rate equal to the data rate.
In many instances in digital electronics, it is necessary to detect the presence of an input signal at a particular moment in time. For example, in magnetic disc storage technology, several coding methods have been developed for use in storing data on rigid or floppy magnetic discs. These coding methods include frequency modulation and modified frequency modulation. In these coding schemes, actual data and clock signals are combined into one signal (Read Data) and recorded on the magnetic disc. In order to read this recorded signal back, electronic controller circuitry especially adapted for detecting the presence of the combined read/clock signal has been used in the past.
The prior art typically requires a system clock for the controller circuitry that operates at a rate twice that of the Read Data ("RD") to be detected from the disc. However, as the frequency of data recording increases in disc devices (particularly in the recent Winchester rigid disc technology), the speed limitations of the metal oxide semiconductor ("MOS") technology typically used in the controller circuits is pressed to its limits and at times exceeded. At present, many Winchester-type discs record the combined clock/data signal at a frequency of five megahertz. The prior art would require controller circuitry operating at ten megahertz in order to read this information.
The present invention consists of a circuit that permits the detection and capture of Read Data at a particular rate using only a system Read Clock ("RC") operating at an equal rate. Thus, a read data signal recorded at five megahertz would require only a five megahertz Read Clock. The lower frequency Read Clock necessary to operate the detection circuitry permits the circuit to be easily fabricated using standard MOS technology.
It is therefore an object of this invention to provide a new and improved digital data capture window extension circuit that permits reading data at a high rate using a system clock that matches the frequency of the incoming data.
SUMMARY OF THE INVENTION
The present invention provides a digital data capture window extension circuit. For purposes of clarity only, the preferred embodiment of the invention is described in the context of its use in a magnetic disc data controller circuit.
The invention provides a matched pair of signal detection subcircuits that are activated during alternate cycles of the Read Clock. The interleaved operation of the paired subcircuits permits each subcircuit a total of two Read Clock cycles to detect and process an incoming Read Data signal. In an ideal circuit, the incoming Read Data is perfectly synchronized with the Read Clock. However, because of imprecision in the various circuits that the Read Data and the Read Clock are processed or affected by, a phase difference may occur between the two signals. The phase difference between Read Data and Read Clock in fact may vary with time, as various circuit parameters change and because of the occurrence of variations that relate to the recorded signal on the magnetic disc itself.
The rising edge of Read Data is nominally in the center of the Read Clock period. Normally, the controller circuitry has a "capture window", equal to the time between the rising edge of Read Clock and the falling edge of Read Clock, in which to detect the occurrence of the Read Data signal. Thereafter, the controller circuit has an "operation window", for further processing of the Read Data signal, that extends only through the next one-half cycle of the Read Clock. If the rising edge of the Read Data signal occurs too close in time to the falling edge of the Read Clock, the controller circuit may not properly "capture" the Read Data signal, or "capture" it too late to have adequate time to further process the signal. Hence, an erroneous logic state may be propagated to the remainder of the controller circuitry.
The present invention extends the "operation window" from one Read Clock half-cycle to two or three Read Clock half-cycles by alternating between a pair of data capture circuits. When one circuit is "capturing" data, the other circuit is processing its previously captured data, and vice versa in the next time cycle.
If the prior art were used with a five megahertz Winchester technology magnetic disc, the data capture circuit would have approximately 100 nanoseconds to capture and process the data. With the present invention, the controller circuit has approximately 400 nanoseconds to capture and process the data signal.
DESCRIPTION OF THE DRAWINGS
The invention will become better understood by reference to the following detailed description when taken in conjunction with the accompanying drawings showing the preferred embodiment of the invention.
FIG. 1A is a schematic logic diagram of the data capture window extension circuit of the present invention.
FIG. 1B is a schematic logic diagram of a subsidiary clock generator circuit used in the preferred embodiment of the present invention.
FIG. 2 is a timing diagram showing the phase relationship of the various signals occurring in the present invention.
FIG. 3 is a schematic diagram of the specialized logic flip-flops used in the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1A, four set-reset flip-flops are shown configured in two pairs of two each. Flip-flops 1 and 2 comprise a first pair of flip-flops for processing a Read Data signal. Flip-flops 3 and 4 comprise a second pair of flip-flops for processing a Read Data signal.
FIG. 2 shows a timing diagram of the various signals used in the present invention. Two timing signals, RC2F and RC2R, and their inverses, RC2F and RC2R, are generated by the clock circuit shown in FIG. 1B, which is simply an inverter ring circuit gated by the Read Clock RC signal and its inverse, RC. These additional signals are one-half the frequency of the Read Clock signal, and RC2F is phase-shifted from RC2R by one-half of an RC cycle. By logically combining RC, RC, RC2F, RC2F, RC2R, and RC2R in various combinations, four cyclic time periods (T1, T2, T3, and T4) are defined.
Again referring to FIG. 1A, flip-flop 1 can be set only if the Read Data RD signal is a logical one during time period T1. Flip-flop 2 can only be set if the Read Data signal is a logical one during time period T2. Both flip-flops 1 and 2 are reset during time period T4, by means of AND gate 7.
The outputs of flip-flops 1 and 2 are Q1 and Q2, respectively. Due to the nature of the set-reset flip-flop circuit used in the present invention (as explained in greater detail below), the Q1 and Q2 outputs are clearly valid during time T3, but also may become valid during times T1 and T2, respectively.
Flip-flops 3 and 4 are essentially identical in structure to flip-flops 1 and 2, respectively. Flip-flop 3 may be set only during time period T3, while flip-flop 4 may be set only during time period T4. Both flip-flops 3 and 4 are reset during time period T2, by means of AND gate 11.
The outputs of flip-flops 3 and 4 are Q3 and Q4, respectively. Due to the nature of the set-reset flip-flop circuit used in the present invention (as explained in greater detail below), the Q3 and Q4 outputs are clearly valid during time T1, but also may become valid during times T3 and T4, respectively.
Referring again now to FIG. 1A, data (or "D-type") flip-flop 30 will accept a logical one input (through AND gate 31 and OR gate 32) whenever the Q1 output of flip-flop 1 is a logical one during time period T3 (thus indicating that the Read Data signal was a logical one during time period T1). Alternatively, D-type flip-flop 30 will accept a logical one input (through AND gate 33 and OR gate 32) whenever the Q3 output of flip-flop 3 is a logical one during time period T1 (thus indicating that the Read Data signal was a logical one during the previous time period T3). D-type flip-flop 30 is clocked by the inverse Read Clock (RC) signal, and the output of that flip-flop is the input to a second D-type flip-flop 34. D-type flip-flop 34 is clocked by the RC signal and its output is an input to AND gate 35.
In similar fashion, the output Q2 of flip-flop 2 is gated (through AND gate 37 and OR gate 38) to the input of D-type flip-flop 36 during time period T3, and the output Q4 of flip-flop 4 is gated (through AND gate 39 and OR gate 38) to the input of D-type flip-flop 36 during the following time period T1. The output of D-type flip-flop 36 is the input to D-type flip-flop 40. The output of D-type flip-flop 40 is the input to AND gate 41.
The output of AND gate 35 is inverted and coupled to the input of AND gate 41. The output of AND gate 35 is also the input to D-type flip-flop 44a, which is the first of a chain of eight D-type flip-flops all clocked by the Read Clock RC. The output of AND gate 41 is the input to D-type flip-flop 45a, which is the first of a chain of nine D-type flip-flops all clocked by the Read Clock RC. The output of D-type flip-flop 45a is also inverted and coupled to the input of AND gate 35.
Referring now to FIG. 3, the schematic structure of a combination AND gate and set-reset flip-flop as used for each of the flip-flops in the preferred embodiment is shown. During a reset cycle, gate 50 is activated, and node 51 is charged from a voltage source, V cc . At any time when all of the set gates 52, 53, 54 are activated during the same time period, node 51 will be discharged to ground. Node 51 is the input to a first inverter 55, which in turn is the input to a second inverter 56. The output of inverter 56 is the Q output of the set-reset flip-flop, while the output of inverter 55 is the Q output of the flip-flop.
Whenever node 51 is a logical one (thus meaning that the flipflop is in its "reset" state), the Q output is a logical zero. Whenever node 51 is a logical zero (thus meaning that the flip-flop is in its "set" state), the Q output is a logical one.
Device 57 is a depletion capacitor designed to enhance the ability of the inverters 55, 56 to produce an unambiguous output by acting as a feedback element. Thus, as node 51 is discharged, the Q output begins to change to a logical zero. The change in voltage at the Q output is coupled back through capacitor 57 to the input of inverter 55, which causes node 51 to be forced further towards a logical zero value.
Gate 58 is also designed to enhance the ability of the inverters 55, 56 to produce an unambiguous logic output. In flip-flops 1 and 2, the corresponding gate 58 is activated by AND gate 8 during time period T3. In flip-flops 3 and 4, the corresponding gate 58 is activated by AND gate 12 during time period T1. Gate 58 causes the flip-flop circuit to function as follows. As node 51 begins to discharge (thus indicating that the set-reset flip-flop is being changed to its "set" state), the Q output begins to change to a logical zero. During the appropriate activation time period, gate 58 couples the Q output to node 51, which tends to force node 51 to the same logic state as the Q output.
The particular set-reset flip-flop structure used in the preferred embodiment is not a necessary part of the invention. It has been chosen because it offers advantages of simplicity and reliability in producing unambiguous logic signals. However, other structures for the AND gate and set-reset flip-flop shown in FIG. 1A may be used without deviating from the scope and intent of the invention.
In operation, flip-flops 1, 2, 3, and 4 are activated in sequence during time periods T1, T2, T3, and T4, respectively. If an RD signal is first detected during time period T1, the Q1 output of flip-flop 1 becomes a logical one.
If Q1 is set to a logical one, the output of D-type flip-flop 30 becomes a logical one during time period T3 (due to the clocking signal RC). Thereafter, the output of D-type flip-flop 34 becomes a logical one during time period T4 (due to the clocking signal RC).
If the RD signal is first detected in time period T2, flip-flop 2 is activated and output Q2 is set to a logical one. If Q2 is a logical one, the output of D-type flip-flop 36 is set to a logical one during time period T3. In turn, the output of D-type flip-flop 40 is set to a logical one during the following T4 time period.
In similar fashion, flip-flops 3 and 4 detect whether an RD signal is first detected during time periods T3 and T4, respectively, and cause D-type flip-flops 34 or 40, respectively, to be set to a logical one during the following time period T1.
The cross-coupling of AND gates 35 and 41 is designed to correct for the erroneous setting of flip-flop 1 by means of a pulse beginning in time period T4 but ending in time period T1, the erroneous setting of flip-flop 2 by means of a pulse beginning in time period T1 and ending in time period T2, the erroneous setting of flip-flop 3 by means of a pulse beginning in time period T2 and ending in time period T3, and the erroneous setting of flip-flop 4 by means of a pulse beginning in time period T3 and ending in time period T4. Any of these occurrences would be considered an illegal state because it would indicate that a RD signal was a logical one in two consecutive time periods, which for the coding schemes used in conjunction with this circuitry would be an illegal signal.
The coupling of the output of D-type flip-flop 45a to the input of AND gate 35 inhibits the output of AND gate 35 whenever flip-flops 2 or 4 have been set in the respective previous time period. On the other hand, if AND gate 35 is not so inhibited, and the outputs of flip-flops 1 or 3 are activated, the output of AND gate 41 is inhibited by the output of AND gate 35.
The effect of the inputs to AND gates 35 and 41 from D-type flip-flops 34 and 40, respectively, is to form a pattern of logic ones and zeroes in the two series of D-type flip-flops shown in FIG. 1A. These two sets of bit patterns may then be read in parallel by circuitry well-known in the prior art to decode the frequency modulation or modified frequency modulation bit coding scheme used to record the RD signal on a magnetic disc.
By comparing the parallel outputs of D-type flip-flops 44a-44g, and of 45a-45h, well-known prior art circuitry can determine whether an RD signal first occurred within time periods T1 or T3, or T2 or T4.
The effect of the paired detection circuits is that flip-flop 1 has a total of three time periods in which to detect and signify to subsequent circuitry the presence or absence of an RD signal in time period T1, and flip-flop 2 has a total of two time periods in which to detect and signify the presence or absence of an RD signal in time period T2. Flip-flops 1 and 2 are then reset in a fourth time period for a next sequence of four time periods. In similar fashion, flip-flops 3 and 4 have a total of three and two time periods, respectively, in which to detect and signify the presence of an RD signal occurring in time periods T3 and T4, respectively. Flip-flops 3 and 4 are then reset in a fourth time period for a next sequence of four time periods. The operation of flip-flops 3 and 4 is one complete RC clock cycle (two time periods) out of phase from the operation of flip-flops 1 and 2. The alternation between the paired detection circuits permits the reading of data at an effective overall processing rate twice that of prior art circuits.
While this invention has been described with reference to a preferred embodiment, it is not intended that this description be construed in a limiting sense. Various modifications of the preferred embodiment, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any modifications or embodiments as fall within the true scope of the invention. | A digital data capture window extension circuit utilizing a matched pair of signal detection subcircuits that are activated during alternate cycles of a master read clock. The interleaved operation of the paired subcircuits permits each subcircuit to detect and process an incoming data signal, resulting in an effective overall processing rate twice that of prior art circuitry. The invention therefore permits the reading of data at a high rate using a system clock of the same frequency as the incoming data. | 6 |
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT
[0001] The present invention relates to a connector. More specifically, the present invention relates to a connector such as an electrical connector for connecting devices electrically, in which a locking mechanism is provided for preventing the connector from coming off.
[0002] In a conventional connector such as an electrical connector, an optical connector, and so on, a locking mechanism is provided therein for preventing the connector connected to a mating connector from coming off the mating connector. For example, a connector having a circular cross-sectional shape such as a coaxial connector, a multi core connector, and so on, is equipped with the various locking mechanisms such as a screw-in style mechanism, a bayonet style mechanism, a push-pull style mechanism, and so on.
[0003] In the conventional connectors described above, the locking mechanism of the push-pull style includes a sleeve having a cylindrical shape on an outer circumference of a connector main body. The sleeve is capable of moving and sliding in a direction of an axis of the connector main body. When an operator unlocks the connector, the operator moves the sleeve in the direction of the axis by holding the sleeve with fingers thereof. When the fingers of the operator are released from the sleeve, the sleeve returns to an initial position automatically, thereby locking the connector.
[0004] In the conventional connector equipped with the locking mechanism of the push-pull style, when the connector is connected to the mating connector, the operator holds the sleeve of the connector with the fingers. Then, the operator applies a force so as to push the connector toward the mating connector in the direction of the axis. Accordingly, the sleeve moves to a distal end side of the connector in the direction of the axis. Thereby, the connector is unlocked and the connector becomes capable of connecting to the mating connector. As a result, the connector is connected to the mating connector as is. Further, the sleeve returns to the initial position as the fingers of the operator are released from the sleeve, thereby locking the connector.
[0005] When the operator extracts the connector from the mating connector, the operator holds the sleeve with the fingers thereof and applies a force so as to pull the connector out of the mating connector in the direction of the axis. Thereby, the sleeve moves to a proximal end side of the connector so that the connector is disengaged. Therefore, the connector is extracted from the mating connector as is.
[0006] As described above, in the conventional connector, the locking mechanism of the push-pull style enables to unlock the connector by simply holding the sleeve then applying the force in the direction that the connector is connected or extracted. Further, the locking mechanism of the push-pull style enables to lock the connector automatically by releasing the sleeve. On the other hand, when the connector is equipped with the locking mechanism of the screw-in style or the bayonet-style, it is necessary to rotate the sleeve thereof around the axis for locking or unlocking the connector. Therefore, the connector equipped with the locking mechanism of the push-pull style can be connected or extracted more easily, as compared to the connectors equipped with the locking mechanisms of the screw-in style and the bayonet-style.
[0007] As described above, the sleeve of the connector with the locking mechanism of the push-pull style automatically returns from a position being moved to the initial position as the operator releases the sleeve. It is attained since the connector is provided with a mechanism therein for returning the sleeve which is moved in the direction of the axis to the initial position. For example, when the connector includes a coil spring therein so that the coil spring is able to expand and contract in the direction of the axis, the sleeve returns to the initial position automatically.
[0008] More specifically, when the operator holds and moves the sleeve with the fingers thereof from the initial position in the direction of the proximal end side or the distal end side, the coil spring contracts with elasticity thereof. Further, when the operator releases the fingers from the sleeve, the coil spring expands with elasticity thereof. Accordingly, when a force generated by the expansion of the coil spring is applied to the sleeve, the sleeve returns to the initial position automatically.
[0009] Further, Patent Reference discloses a conventional connector having a mechanism for returning a locking sleeve to an initial position utilizing elasticity.
[0010] In the conventional connector disclosed in Patent Reference, the mechanism includes a locking sleeve and an elastic portion provided on other end of the locking sleeve. When a cam formed in the elastic portion contacts with a surface (a concaved portion with a slightly inclined surface) formed in an outer circumferential portion on the other end of a coupler, the elastic portion is deformed outward in a direction of a diameter thereof as the locking sleeve is moved from the initial position toward an end or the other end. Thereby, the locking sleeve returns to the initial position by utilizing the elasticity of the elastic portion.
Patent Reference Japanese Patent Publication No. 2003-516606
[0011] As described above, the conventional connector having the locking mechanism of the push-pull style includes the mechanism for returning the sleeve moved in the direction of the axis to the initial position. However, the mechanism described above has problems described below.
[0012] When the mechanism for returning the sleeve automatically to the initial position is configured with the coil spring as described above, the connector needs to include the coil spring, a spring washer, a space to expand and contract of the coil spring, and so on therein. As a result, a dimension of the connector in the direction of the axis becomes larger. Therefore, the connector becomes larger in size.
[0013] Further, as disclosed in Patent Reference, when the connector is equipped with the mechanism configured with the locking sleeve and the elastic portion provided on the other end of the locking sleeve, the connector becomes larger in size since the dimension of the connector in the direction of the axis also becomes larger.
[0014] More specifically, the elastic portion needs to have a certain length in the direction of the axis in order to obtain proper elasticity generated by deformation thereof. When the elastic portion has a short length as described in Patent Reference, the elastic portion tends to generate an excessive elastic force toward outside in the direction of the diameter. Consequently, a strong force is required to move the sleeve in the direction of the axis. As a result, it becomes difficult to lock and unlock easily. According to simulation, the elastic portion may need to be twice as long in the direction of the axis as disclosed in Patent Reference in order to obtain preferred operability for locking and unlocking.
[0015] Furthermore, in the conventional connector, when the mechanism for returning the sleeve to the initial position is configured with the locking sleeve and the elastic portion provided on the other end of the locking sleeve as disclosed in Patent Reference, it is difficult to provide the connector with proper durability and reduce the size of the connector.
[0016] More specifically, in the conventional connector disclosed in Patent Reference, the elastic portion has a shape of a collet chuck. Thereby, the elastic portion is capable of elastically deforming toward outside in the direction of the diameter. On the other hand, rigidity of the elastic portion becomes less strong consequently, since the elastic portion has a shape of a collet chuck. As a result, the connector is not able to obtain the sufficient durability.
[0017] Generally, when the connector is handled normally, the connector often receives an external force. For example, the elastic portion receives a force due to a forcible twisting upon extraction of the connector, or an external force generated as a cable connected to the other end of the connector is pulled in a direction crossing the direction of the axis of the connector. It is difficult for the elastic portion having the shape of the collet chuck to have sufficient durability against the forcible twisting or the external force described above.
[0018] In view of the problems described above, an object of the present invention is to provide a connector capable of reducing a size thereof, especially a size thereof in a direction of an axis thereof, as well as being equipped with a locking mechanism.
[0019] A further object of the present invention is to provide a connector having a locking mechanism including a sufficiently rigid movable sleeve arranged to be movable in the direction of the axis for locking and unlocking the connector, so that the connector is sufficiently durable and capable of preventing the movable sleeve thereof from being damaged or deformed due to the forcible twisting and so on.
[0020] Further objects and advantages of the invention will be apparent from the following description of the invention.
SUMMARY OF THE INVENTION
[0021] In order to attain the objects described above, according to a first aspect of the present invention, a first connector is to be connected to a mating connector.
[0022] According to the first aspect of the present invention, the connector includes a connector main body including a cylindrical member formed in a cylindrical shape, a supporting member disposed in the cylindrical member, a terminal supported on the supporting member on a proximal end side of the cylindrical member and extending in an axial direction, and a fitting portion formed on a distal end side of the cylindrical member for receiving the mating connector and engaging with the mating connector.
[0023] According to the first aspect of the present invention, the fitting portion is arranged to be elastically deformable to increase a diameter thereof. Further, the fitting portion has an engaging portion on an inner circumference side thereof. When the mating connector starts entering the fitting portion, the fitting portion expands in the radial direction thereof, so that the mating connector is allowed to enter the fitting portion. Further, when the mating connector is completely inserted into the fitting portion, the fitting portion returns to an original shape thereof, and the engaging portion engages with an engaged portion formed on the mating connector.
[0024] According to the first aspect of the present invention, the connector further includes a movable sleeve formed in a ring shape and disposed on an outer circumference side of the connector main body to be movable along the axial direction thereof relative to the connector main body. The movable sleeve including a diameter control portion at the distal end side for controlling an expansion of the fitting portion in the radial direction. When the movable sleeve is situated at an initial position, the diameter control portion moves close to or contacts with an outer circumferential portion of the fitting portion, so that the fitting portion is not capable of expanding in the radial direction. Further, when the movable sleeve moves toward the distal end side or the proximal end side from the initial position along the axial direction, the diameter control portion moves away from the outer circumferential portion of the fitting portion, so that the fitting portion is capable of expanding in the radial direction.
[0025] According to the first aspect of the present invention, the connector further includes an elastic deformation member formed in a substantially ring shape and disposed to be elastically deformable in a radial direction thereof; and an accommodating portion disposed between an outer circumferential portion of the connector main body on the proximal end side and an inner circumferential portion of the movable sleeve on the proximal end side for accommodating the elastic deformation member in a state that the fitting portion is capable of expanding in the radial direction.
[0026] According to the first aspect of the present invention, the connector further includes a transmission unit for converting a force in the axial direction generated when the movable sleeve moves toward the distal end side or the proximal end side from the initial position along the axial direction into a force in the radial direction for deforming the elastic deformation member, and for transmitting the force in the radial direction to the elastic deformation member. The transmission unit is further provided for converting the force in the radial direction to restore the elastic deformation member from the deformed state into the force in the axial direction to return the movable sleeve moves from the distal end side or the proximal end side to the initial position along the axial direction, and for transmitting the force in the axial direction to the movable sleeve.
[0027] According to the first aspect of the present invention, when the connector is connected to the mating connector, an operator holds the movable sleeve with fingers, and pushes the connector towards the mating connector in a state that the distal end portion of the fitting portion of the connector contacts with a distal end portion of the mating connector. With the force in the axial direction, the movable sleeve of the connector moves from the initial position to the distal end side in the axial direction.
[0028] According to the first aspect of the present invention, the transmission unit is provided for converting the force in the axial direction generated when the movable sleeve moves toward the distal end side along the axial direction into the force in the radial direction, and for transmitting the force in the radial direction to the elastic deformation member. Accordingly, the elastic deformation member deforms in the radial direction. Further, when the movable sleeve moves from the initial position, the diameter control portion moves away from the outer circumferential portion of the fitting portion, so that the fitting portion is capable of expanding in the radial direction.
[0029] According to the first aspect of the present invention, when the fitting portion expands in the radial direction, the mating connector can be inserted into the fitting portion. When the mating connector enters up to a back side of the fitting portion and is completely inserted into the fitting portion, the fitting portion contracts and returns to the original shape. Accordingly, the engaging portion engages with the engaged portion of the mating connector.
[0030] According to the first aspect of the present invention, when the operator releases the fingers from the movable sleeve, the force in the axial direction to move the movable sleeve toward the distal end side in the axial direction disappears. As a result, the force in the radial direction transmitted to the elastic deformation member disappears, so that the elastic deformation member returns to the original shape thereof with own elastic force.
[0031] At this moment, the transmission unit is provided for converting the force in the radial direction to return the elastic deformation member to the original shape into the force in the axial direction to return the movable sleeve moves from the distal end side to the initial position along the axial direction, and for transmitting the force in the axial direction to the movable sleeve. Accordingly, the movable sleeve at the distal end side in the axial direction automatically returns to the initial position.
[0032] According to the first aspect of the present invention, when the connector is disconnected from the mating connector, the operator holds the movable sleeve with the fingers, and pulls the connector away from the mating connector. With the force in the axial direction, the movable sleeve of the connector moves from the initial position to the proximal end side in the axial direction.
[0033] According to the first aspect of the present invention, the transmission unit is provided for converting the force in the axial direction to move the movable sleeve toward the proximal end side along the axial direction into the force in the radial direction, and for transmitting the force in the radial direction to the elastic deformation member. Accordingly, the elastic deformation member deforms in the radial direction. Further, when the movable sleeve moves from the initial position, the diameter control portion moves away from the outer circumferential portion of the fitting portion, so that the fitting portion is capable of expanding in the radial direction. Accordingly, the engaging portion is disengaged from the engaged portion of the mating connector, and the mating connector is pulled out from the fitting portion.
[0034] According to the first aspect of the present invention, when the operator releases the fingers from the movable sleeve, the force in the axial direction to move the movable sleeve toward the proximal end side in the axial direction disappears. As a result, the force in the radial direction transmitted to the elastic deformation member disappears, so that the elastic deformation member returns to the original shape thereof with own elastic force.
[0035] At this moment, the transmission unit is provided for converting the force in the radial direction to return the elastic deformation member to the original shape into the force in the axial direction to return the movable sleeve moves from the proximal end side to the initial position along the axial direction, and for transmitting the force in the axial direction to the movable sleeve. Accordingly, the movable sleeve at the proximal end side in the axial direction automatically returns to the initial position.
[0036] As described above, in the first aspect of the present invention, utilizing the force in the radial direction to return the elastic deformation member thus deformed I to the original shape, it is possible to automatically return the movable sleeve moved to the distal end side or the proximal end side in the axial direction to the initial position. In other words, it is possible to automatically return the movable sleeve to the initial position with the simple configuration, in which the elastic deformation member is disposed between the movable sleeve and the connector main body.
[0037] Accordingly, as opposed to the conventional configuration, in which the coil spring is provided for automatically returning the movable sleeve to the initial position, or the movable member itself is configured to elastically deform, in the first aspect of the present invention, it is possible to reduce a dimension of the connector in the axial direction, thereby reducing a size of the connector.
[0038] Further, in the first aspect of the present invention, it is possible to automatically return the movable sleeve to the initial position with the simple configuration, in which the elastic deformation member is disposed between the movable sleeve and the connector main body. Accordingly, as opposed to the conventional configuration, it is not necessary to elastically deform the movable sleeve itself. As a result, it is possible to increase rigidity of the movable sleeve, thereby improving durability of the connector.
[0039] In order to attain the objects described above, according to a second aspect of the present invention, in the connector in the first aspect, the elastic deformation member may be formed in a C character shape. Accordingly, it is possible to produce the elastic deformation member capable of elastically deforming in the radial direction with the simple configuration or the simple part.
[0040] In order to attain the objects described above, according to a third aspect of the present invention, in the connector in the first aspect or the second aspect, the transmission unit may include a first inclined surface formed on the outer circumferential portion of the elastic deformation member, a second inclined surface formed on the outer circumferential portion of the elastic deformation member, and a sliding contact portion extending from the inner circumferential portion of the movable sleeve inwardly in the radial direction.
[0041] According to the third aspect of the present invention, the first inclined surface is inclined outwardly in the radial direction from a middle portion to a distal end portion of the elastic deformation member in the axial direction. Further, the second inclined surface is inclined outwardly in the radial direction from the middle portion to a proximal end portion of the elastic deformation member in the axial direction. Further, the sliding contact portion has an end portion arranged to slide against the first inclined surface of the elastic deformation member when the movable sleeve moves toward the distal end side from the initial position, and to slide against the second inclined surface of the elastic deformation member when the movable sleeve moves toward the proximal end side from the initial position.
[0042] According to the third aspect of the present invention, the first inclined surface and the second inclined surface are formed on the outer circumferential portion of the elastic deformation member, so that the outer circumferential portion of the elastic deformation member has a shape recessed at the middle portion in the axial direction. When the movable sleeve is situated at the initial position, the sliding contact portion of the movable sleeve is situated on the outer circumferential portion of the elastic deformation member at the middle portion thus recessed in the axial direction. In this state, the elastic deformation member, for example, does not deform at all in the radial direction, or deforms only slightly.
[0043] According to the third aspect of the present invention, when the operator holds the movable sleeve with the fingers, and applies a force to the movable sleeve to move the movable sleeve from the initial position toward the distal end side in the axial direction, the sliding contact portion of the movable sleeve is moved toward the distal end side in the axial direction while sliding against the first inclined surface of the elastic deformation member. As described above, the first inclined surface is inclined outwardly in the radial direction from the middle portion to the distal end portion of the elastic deformation member in the axial direction. Accordingly, when the sliding contact portion of the movable sleeve is moved toward the distal end side in the axial direction, the sliding contact portion pushes the first inclined surface. As a result, the elastic deformation member deforms inwardly in the radial direction.
[0044] According to the third aspect of the present invention, when the operator releases the fingers from the movable sleeve, the elastic deformation member returns to the original shape, and generates the force outwardly in the radial direction. Accordingly, the force is applied to the sliding contact portion of the movable sleeve contacting with the first inclined surface of the elastic deformation member. As described above, the first inclined surface is inclined outwardly in the radial direction from the middle portion to the distal end portion of the elastic deformation member in the axial direction. Accordingly, the sliding contact portion is pushed toward the proximal end side in the axial direction. As a result, the movable sleeve is pushed back to the initial position from the distal end side in the axial direction.
[0045] According to the third aspect of the present invention, similarly, when the operator holds the movable sleeve with the fingers, and applies a force to the movable sleeve to move the movable sleeve from the initial position toward the proximal end side in the axial direction, the sliding contact portion of the movable sleeve pushes the second inclined surface. As a result, the elastic deformation member deforms inwardly in the radial direction. When the operator releases the fingers from the movable sleeve, the elastic deformation member returns to the original shape, and generates the force outwardly in the radial direction. Accordingly, the force is applied to the sliding contact portion of the movable sleeve contacting with the second inclined surface of the elastic deformation member. Accordingly, the sliding contact portion is pushed, and the movable sleeve is pushed back to the initial position from the proximal end side in the axial direction.
[0046] In the third aspect of the present invention, as described above, after the elastic deformation member is deformed, when the elastic deformation member returns to the original shape to generate the force in the radial direction, the force in the radial direction is converted into the force in the axial direction. Then, the force in the axial direction is transmitted to the movable sleeve. Accordingly, it is possible to automatically return the movable sleeve to the initial position from the distal end side or the proximal end side in the axial direction with the simple configuration.
[0047] In order to attain the objects described above, according to a fourth aspect of the present invention, in the connector in the first aspect or the second aspect, the transmission unit may include a first inclined surface formed on the outer circumferential portion of the elastic deformation member, a second inclined surface formed on the outer circumferential portion of the elastic deformation member, a first sliding contact portion extending from the inner circumferential portion of the movable sleeve on the proximal end side inwardly in the radial direction, and a second sliding contact portion extending from the inner circumferential portion of the movable sleeve on the proximal end side inwardly in the radial direction.
[0048] According to the fourth aspect of the present invention, the first inclined surface is inclined inwardly in the radial direction from a middle portion to a distal end portion of the elastic deformation member in the axial direction. Further, the second inclined surface is inclined inwardly in the radial direction from the middle portion to a proximal end portion of the elastic deformation member in the axial direction. Further, the first sliding contact portion has an end portion arranged to slide against the second inclined surface of the elastic deformation member when the movable sleeve moves toward the distal end side from the initial position. Further, the second sliding contact portion has an end portion arranged to slide against the first inclined surface of the elastic deformation member when the movable sleeve moves toward the proximal end side from the initial position.
[0049] According to the fourth aspect of the present invention, the first inclined surface and the second inclined surface are formed on the outer circumferential portion of the elastic deformation member, so that the outer circumferential portion of the elastic deformation member has a shape protruded at the middle portion in the axial direction. When the movable sleeve is situated at the initial position, the middle portion thus protruded in the axial direction on the outer circumferential portion of the elastic deformation member is situated between the first sliding contact portion and the second sliding contact portion of the movable sleeve. In this state, the elastic deformation member, for example, does not deform at all in the radial direction, or deforms only slightly.
[0050] According to the fourth aspect of the present invention, when the operator holds the movable sleeve with the fingers, and applies a force to the movable sleeve to move the movable sleeve from the initial position toward the distal end side in the axial direction, the first sliding contact portion of the movable sleeve is moved toward the distal end side in the axial direction while sliding against the second inclined surface of the elastic deformation member. As described above, the second inclined surface is inclined inwardly in the radial direction from the middle portion to the proximal end portion of the elastic deformation member in the axial direction. Accordingly, when the first sliding contact portion of the movable sleeve is moved toward the distal end side in the axial direction, the first sliding contact portion pushes the second inclined surface. As a result, the elastic deformation member deforms inwardly in the radial direction.
[0051] According to the fourth aspect of the present invention, when the operator releases the fingers from the movable sleeve, the elastic deformation member returns to the original shape, and generates the force outwardly in the radial direction. Accordingly, the force is applied to the first sliding contact portion of the movable sleeve contacting with the second inclined surface of the elastic deformation member. As described above, the second inclined surface is inclined inwardly in the radial direction from the middle portion to the proximal end portion of the elastic deformation member in the axial direction. Accordingly, the first sliding contact portion is pushed toward the proximal end side in the axial direction. As a result, the movable sleeve is pushed back to the initial position from the distal end side in the axial direction.
[0052] According to the fourth aspect of the present invention, similarly, when the operator holds the movable sleeve with the fingers, and applies a force to the movable sleeve to move the movable sleeve from the initial position toward the proximal end side in the axial direction, the second sliding contact portion of the movable sleeve pushes the first inclined surface. As a result, the elastic deformation member deforms inwardly in the radial direction. When the operator releases the fingers from the movable sleeve, the elastic deformation member returns to the original shape, and generates the force outwardly in the radial direction. Accordingly, the force is applied to the second sliding contact portion of the movable sleeve contacting with the second inclined surface of the elastic deformation member. Accordingly, the second sliding contact portion is pushed, and the movable sleeve is pushed back to the initial position from the proximal end side in the axial direction.
[0053] In the fourth aspect of the present invention, as described above, when the elastic deformation member returns to the original shape to generate the force in the radial direction, the force in the radial direction is converted into the force in the axial direction. Then, the force in the axial direction is transmitted to the movable sleeve. Accordingly, it is possible to automatically return the movable sleeve to the initial position from the distal end side or the proximal end side in the axial direction with the simple configuration.
[0054] In order to attain the objects described above, according to a fifth aspect of the present invention, in the connector in the first aspect or the second aspect, the transmission unit may include a first inclined surface formed on the inner circumferential portion of the elastic deformation member, a second inclined surface formed on the inner circumferential portion of the elastic deformation member, and a sliding contact portion extending from the outer circumferential portion of the cylindrical member of the connector main body on the proximal end side outwardly in the radial direction.
[0055] According to the fifth aspect of the present invention, the first inclined surface is inclined inwardly in the radial direction from a middle portion to a distal end portion of the elastic deformation member in the axial direction. Further, the second inclined surface is inclined inwardly in the radial direction from the middle portion to a proximal end portion of the elastic deformation member in the axial direction. Further, the sliding contact portion has an end portion arranged to slide against the second inclined surface of the elastic deformation member when the movable sleeve moves toward the distal end side from the initial position, and to slide against the first inclined surface of the elastic deformation member when the movable sleeve moves toward the proximal end side from the initial position.
[0056] According to the fifth aspect of the present invention, when the operator holds the movable sleeve with the fingers, and applies a force to the movable sleeve to move the movable sleeve from the initial position toward the distal end side in the axial direction, the sliding contact portion of the movable sleeve pushes the second inclined surface of the elastic deformation member. As a result, the elastic deformation member deforms outwardly in the radial direction.
[0057] According to the fifth aspect of the present invention, when the operator releases the fingers from the movable sleeve, the elastic deformation member returns to the original shape, and generates the force inwardly in the radial direction. Accordingly, the force is applied to the sliding contact portion of the movable sleeve contacting with the second inclined surface of the elastic deformation member. Accordingly, the sliding contact portion is pushed toward, and the movable sleeve is pushed back to the initial position from the distal end side in the axial direction.
[0058] According to the fifth aspect of the present invention, similarly, when the operator holds the movable sleeve with the fingers, and applies a force to the movable sleeve to move the movable sleeve from the initial position toward the proximal end side in the axial direction, the sliding contact portion of the movable sleeve pushes the first inclined surface. As a result, the elastic deformation member deforms outwardly in the radial direction. When the operator releases the fingers from the movable sleeve, the elastic deformation member returns to the original shape, and generates the force inwardly in the radial direction. Accordingly, the force is applied to the sliding contact portion of the movable sleeve contacting with the second inclined surface of the elastic deformation member. Accordingly, the sliding contact portion is pushed, and the movable sleeve is pushed back to the initial position from the proximal end side in the axial direction.
[0059] In the fifth aspect of the present invention, as described above, when the elastic deformation member returns to the original shape to generate the force in the radial direction, the force in the radial direction is converted into the force in the axial direction. Then, the force in the axial direction is transmitted to the movable sleeve. Accordingly, it is possible to automatically return the movable sleeve to the initial position from the distal end side or the proximal end side in the axial direction with the simple configuration.
[0060] In order to attain the objects described above, according to a sixth aspect of the present invention, in the connector in the first aspect or the second aspect, the transmission unit may include a first inclined surface formed on the inner circumferential portion of the elastic deformation member, a second inclined surface formed on the inner circumferential portion of the elastic deformation member, a first sliding contact portion extending from the outer circumferential portion of the cylindrical member of the connector main body on the proximal end side inwardly in the radial direction, and a second sliding contact portion extending from the outer circumferential portion of the cylindrical member of the connector main body on the proximal end side inwardly in the radial direction.
[0061] According to the sixth aspect of the present invention, the first inclined surface is inclined outwardly in the radial direction from a middle portion to a distal end portion of the elastic deformation member in the axial direction. Further, the second inclined surface is inclined outwardly in the radial direction from the middle portion to a proximal end portion of the elastic deformation member in the axial direction. Further, the first sliding contact portion has an end portion arranged to slide against the first inclined surface of the elastic deformation member when the movable sleeve moves toward the distal end side from the initial position. Further, the second sliding contact portion has an end portion arranged to slide against the second inclined surface of the elastic deformation member when the movable sleeve moves toward the proximal end side from the initial position.
[0062] According to the sixth aspect of the present invention, when the operator holds the movable sleeve with the fingers, and applies a force to the movable sleeve to move the movable sleeve from the initial position toward the distal end side in the axial direction, the first sliding contact portion of the movable sleeve pushes the first inclined surface of the elastic deformation member. As a result, the elastic deformation member deforms outwardly in the radial direction.
[0063] According to the sixth aspect of the present invention, when the operator releases the fingers from the movable sleeve, the elastic deformation member returns to the original shape, and generates the force inwardly in the radial direction. Accordingly, the force is applied to the first sliding contact portion of the movable sleeve contacting with the first inclined surface of the elastic deformation member. Accordingly, the first sliding contact portion is pushed, and the movable sleeve is pushed back to the initial position from the distal end side in the axial direction.
[0064] According to the sixth aspect of the present invention, similarly, when the operator holds the movable sleeve with the fingers, and applies a force to the movable sleeve to move the movable sleeve from the initial position toward the proximal end side in the axial direction, the second sliding contact portion of the movable sleeve pushes the second inclined surface. As a result, the elastic deformation member deforms outwardly in the radial direction. When the operator releases the fingers from the movable sleeve, the elastic deformation member returns to the original shape, and generates the force inwardly in the radial direction. Accordingly, the force is applied to the second sliding contact portion of the movable sleeve contacting with the second inclined surface of the elastic deformation member. Accordingly, the second sliding contact portion is pushed, and the movable sleeve is pushed back to the initial position from the proximal end side in the axial direction.
[0065] In the sixth aspect of the present invention, as described above, when the elastic deformation member returns to the original shape to generate the force in the radial direction, the force in the radial direction is converted into the force in the axial direction. Then, the force in the axial direction is transmitted to the movable sleeve. Accordingly, it is possible to automatically return the movable sleeve to the initial position from the distal end side or the proximal end side in the axial direction with the simple configuration.
[0066] In order to attain the objects described above, according to a seventh aspect of the present invention, a pair of connectors includes a first connector and a second connector both mutually and detachably connected.
[0067] According to the seventh aspect of the present invention, the first connector includes a first cylindrical member formed in a cylindrical shape, a first supporting member disposed in the first cylindrical member, a first terminal supported on the first supporting member and extending in an axial direction, and a fitting portion formed on a distal end side of the first cylindrical member for receiving the second connector and engaging with the second connector.
[0068] According to the seventh aspect of the present invention, the fitting portion is arranged to be elastically deformable to increase a diameter thereof. Further, the fitting portion has an engaging portion on an inner circumference side thereof. When the second connector starts entering the fitting portion, the fitting portion expands in the radial direction thereof, so that the second connector is allowed to enter the fitting portion. Further, when the second connector is completely inserted into the fitting portion, the fitting portion returns to an original shape thereof, and the engaging portion engages with an engaged portion formed on the second connector.
[0069] According to the seventh aspect of the present invention, the second connector includes a connector main body including a second cylindrical member formed in a cylindrical shape, a second supporting member disposed in the second cylindrical member, a second terminal supported on the second supporting member on a proximal end side of the second cylindrical member and extending in an axial direction, and the engaged portion formed on an outer circumferential portion of the cylindrical member on a distal end side thereof.
[0070] According to the seventh aspect of the present invention, the connector further includes a movable sleeve formed in a ring shape and disposed on an outer circumference side of the connector main body to be movable along the axial direction thereof relative to the connector main body. The movable sleeve including a diameter control portion for controlling an expansion of the fitting portion of the first connector in the radial direction. When the movable sleeve is situated at an initial position, the diameter control portion moves close to or contacts with an outer circumferential portion of the fitting portion, so that the fitting portion is not capable of expanding in the radial direction. Further, when the movable sleeve moves toward the distal end side or the proximal end side from the initial position along the axial direction, the diameter control portion moves away from the outer circumferential portion of the fitting portion, so that the fitting portion is capable of expanding in the radial direction.
[0071] According to the seventh aspect of the present invention, the connector further includes an elastic deformation member formed in a substantially ring shape and disposed to be elastically deformable in a radial direction thereof; and an accommodating portion disposed between an outer circumferential portion of the connector main body on the proximal end side and an inner circumferential portion of the movable sleeve on the proximal end side for accommodating the elastic deformation member in a state that the fitting portion is capable of expanding in the radial direction.
[0072] According to the seventh aspect of the present invention, the connector further includes a transmission unit for converting a force in the axial direction generated when the movable sleeve moves toward the distal end side or the proximal end side from the initial position along the axial direction into a force in the radial direction for deforming the elastic deformation member, and for transmitting the force in the radial direction to the elastic deformation member. The transmission unit is further provided for converting the force in the radial direction to restore the elastic deformation member from the deformed state into the force in the axial direction to return the movable sleeve moves from the distal end side or the proximal end side to the initial position along the axial direction, and for transmitting the force in the axial direction to the movable sleeve.
[0073] In the seventh aspect of the present invention, the elastic deformation member is disposed between the movable sleeve and the connector main body. Accordingly, it is possible to automatically return the movable sleeve of the second connector to the initial position from the distal end side or the proximal end side in the axial direction with the simple configuration. As a result, it is possible to reduce a size of the second connector and improve the durability thereof.
[0074] As described above, in the present invention, the connector includes the lock mechanism of the push-pull type, and it is possible to reduce the size of the connector through decreasing the dimension in the axial direction. Further, it is possible to increase the rigidity of the movable sleeve. Accordingly, it is possible to prevent deformation or damage due to twisting and the like, thereby making it possible to improve the durability of the connector.
BRIEF DESCRIPTION OF THE DRAWINGS
[0075] FIG. 1 is a perspective view showing an electrical connector according to a first embodiment of the present invention;
[0076] FIG. 2 is a sectional view showing the electrical connector according to the first embodiment of the present invention, taken along a line II-II in FIG. 1 ;
[0077] FIG. 3 is a perspective view showing an elastic deformation member of the electrical connector according to the first embodiment of the present invention;
[0078] FIG. 4 is a view showing measurements of various portions in the electrical connector at a proximal end portion thereof, according to the first embodiment of the present invention;
[0079] FIG. 5 is a perspective view showing a mating connector according to the first embodiment of the present invention;
[0080] FIG. 6 is a sectional view showing the mating connector according to the first embodiment of the present invention;
[0081] FIGS. 7(A) to 7(D) are sectional views showing a process of connecting the electrical connector to the mating connector, according to the first embodiment of the present invention;
[0082] FIGS. 8(A) and 8(B) are sectional views showing a process of extracting the electrical connector from the mating connector, according to the first embodiment of the present invention;
[0083] FIG. 9 is a sectional view showing an electrical connector according to a second embodiment of the present invention;
[0084] FIG. 10 is a sectional view showing an electrical connector according to a third embodiment of the present invention;
[0085] FIG. 11 is a sectional view showing an electrical connector according to a fourth embodiment of the present invention;
[0086] FIG. 12 is a sectional view showing an electrical connector according to a fifth embodiment of the present invention;
[0087] FIG. 13 is a sectional view showing a pair of electrical connectors according to a sixth embodiment of the present invention;
[0088] FIG. 14 is a sectional view showing a mating connector according to a modified example of the present invention; and
[0089] FIG. 15 is a sectional view showing a mating connector according to another modified example of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0090] Hereunder, an electrical connector according to an embodiment of the present invention will be explained with reference to the accompanying drawings.
First Embodiment
[0091] A first embodiment of the present invention will be explained. FIGS. 1 and 2 show an electrical connector according to a first embodiment of the present invention. FIG. 3 shows an elastic deformation member provided to the electrical connector. FIG. 3 shows measurements of various portions in the electrical connector at a proximal end portion thereof.
[0092] As shown in FIG. 1 , the electrical connector 1 according to the first embodiment of the present invention is a coaxial connector equipped with a locking mechanism of push-pull style. The electrical connector 1 is configured substantially with a connector main body 11 and a movable sleeve 21 being movable in a direction of an axis, provided around an outer circumference of the connector main body 11 .
[0093] As shown in FIG. 2 , the connector main body 11 includes a cylindrical member 12 . The cylindrical member 12 forms an outer shell of the connector main body 11 . In addition, the cylindrical member 12 functions as an external terminal contacting electrically with an external conductive member of a coaxial cable (not shown) connected to another end of the electrical connector 1 . The cylindrical member 12 is configured with a cylindrical portion 13 and a cylindrical portion 14 connected to each other.
[0094] In the embodiment, the cylindrical portion 13 and the cylindrical portion 14 have cylindrical shapes and are made from a metallic material, respectively. In other words, the cylindrical member 12 is configured by pushing a connecting portion 13 A at a proximal end of the cylindrical portion 13 and a connecting portion 14 A at a distal end of the cylindrical portion 14 into each other when the electrical connector 1 is manufactured.
[0095] A central terminal 15 is provided at the proximal end portion of inside the cylindrical member 12 . The central terminal 15 contacts with a central conductive member of the coaxial cable described above. The central terminal 15 is fixed in a position of a central axis of the cylindrical member 12 with a supporting member 16 . The supporting member 16 is made from an insulating material such as a resin. A tip portion of the central terminal 15 protrudes into a fitting portion 17 , which will be described later.
[0096] In the embodiment, the cylindrical member 12 includes the fitting portion 17 at a distal end portion thereof. The fitting portion 17 receives a mating connector 2 (refer to FIG. 5 ) in order to connect to the mating connector 2 . The fitting portion 17 has a space inside thereof for receiving a distal end portion of the mating connector 2 . Further, the fitting portion 17 has an opening at the distal end of the electrical connector 1 . The fitting portion 17 has a shape of collet chucks. That is, the distal end portion of the fitting portion 17 is divided into a plurality of segments 19 by a dividing groove 18 formed in the distal end portion of the fitting portion 17 at a plurality of positions in a circumferential direction. Accordingly, the fitting portion 17 is capable of expanding a diameter thereof elastically in a direction of an arrow Dr shown in FIG. 2 .
[0097] In the embodiment, the fitting portion 17 includes an engaging portion 20 in an inner circumferential portion thereof. The engaging portion 20 protrudes at the distal end portion of the fitting portion 17 toward inside in a direction of the diameter thereof. The engaging portion 20 engages an engaged portion 36 of the mating connector 2 when the mating connector 2 is connected to the fitting portion 17 .
[0098] The movable sleeve 21 is formed in a cylindrical shape and made from, for example, a metallic material, a resin material and the like. The movable sleeve 21 is attached to the connector main body 11 so as to surround the outer circumference of the connector main body 11 from the proximal end of the connector main body 11 to the distal end of the fitting portion 17 . Further, the movable sleeve 21 is movable against the connector main body 11 in the direction of the axis, in other words, in directions of arrows Db and Df shown in FIG. 2 .
[0099] In addition, the movable sleeve 21 includes a diameter control portion 22 in a distal end portion of the inner circumference thereof. The diameter control portion 22 prevents the fitting portion 17 from expanding the diameter thereof as the movable sleeve 21 is situated in an initial position, while enabling the fitting portion 17 to expand the diameter thereof as the movable sleeve 21 is moved in a direction of the proximal end or in a direction of the distal end from the initial position.
[0100] In the embodiment, the diameter control portion 22 protrudes from the distal end portion of the movable sleeve 21 inwardly in the direction of the diameter thereof. When the movable sleeve 21 is in the initial position, an end portion of an inner circumferential surface of the diameter control portion 22 is situated close to an outer circumferential surface of the distal end portion of the fitting portion 17 .
[0101] More specifically, when the movable sleeve 21 is in the initial position, the end portion of the inner circumferential surface of the diameter control portion 22 faces the outer circumferential surface of the distal end portion of the fitting portion 17 with a narrow space in between, as well as surrounding the entire outer circumferential surface of the distal end portion of the fitting portion 17 . Therefore, the fitting portion 17 is not allowed to expand the diameter thereof since the outer circumferential surface of the distal end portion of the fitting portion 17 abuts against the end portion of the inner circumferential surface of the diameter control portion 22 .
[0102] When the movable sleeve 21 is in the initial position, the end portion of the inner circumferential surface of the diameter control portion 22 may contact with the outer circumferential surface of the distal end portion of the fitting portion 17 so as to be moved slidingly.
[0103] When the movable sleeve 21 is moved from the initial position to the distal end in the direction of the axis, the diameter control portion 22 is moved from the distal end portion of the fitting portion 17 in the direction of the arrow Df, being apart from the distal end portion of the fitting portion 17 . Therefore, a relatively larger space is generated between the distal end portion of the inner circumferential surface of the diameter control portion 22 and the outer circumferential surface of the distal end portion of the fitting portion 17 . Thereby, the fitting portion 17 is allowed to expand the diameter thereof.
[0104] In addition, when the movable sleeve 21 is moved from the initial position to the proximal end in the direction of the axis, the diameter control portion 22 is moved in the direction of the arrow Db from the distal end portion of the fitting portion 17 , being apart from the distal end portion of the fitting portion 17 . In this case, the distal end portion of the fitting portion 17 protrudes from the movable sleeve 21 , thereby the fitting portion 17 is allowed to expand the diameter thereof.
[0105] In the embodiment, the movable sleeve 21 further includes a holding portion 23 at an outer circumferential surface of a proximal end portion thereof. When an operator moves the movable sleeve 21 , the operator holds the holding portion 23 of the movable sleeve 21 with fingers. The holding portion 23 has an uneven surface in order to prevent the fingers from slipping.
[0106] Furthermore, the electrical connector 1 includes the elastic deformation member 24 , an accommodating portion 25 and a transmission unit 26 as a mechanism so that the movable sleeve 21 moved in the direction of the axis is able to return to the initial position automatically. The accommodating portion 25 accommodates the elastic deformation member 24 and the transmission unit 26 generates force bringing back the movable sleeve 21 to the initial position by utilizing elastic force of the elastic deformation member 24 .
[0107] As shown in FIG. 2 , the elastic deformation member 24 is situated between the connector main body 11 and the movable sleeve 21 at the proximal end portion of the connector main body 11 . As shown in FIG. 3 , the elastic deformation member 24 is made from a resin material and has a substantial ring shape, namely, has a C-letter shape as a whole with a separation space 24 A. The elastic deformation member 24 is capable of being deformed with elasticity thereof in a direction of a diameter thereof.
[0108] In other words, the elastic deformation member 24 is deformed so as to shrink the diameter thereof by changing a width the separation space 24 A as the elastic deformation member 24 receives an external force toward inside in the direction of the diameter from an outer circumference thereof. When it stops applying the external force after the elastic deformation member 24 is deformed, the elastic deformation member 24 restores the shape as shown in FIG. 3 , expanding the diameter thereof by the elasticity thereof.
[0109] In the embodiment, the accommodating portion 25 , as shown in FIG. 2 , is situated between the outer circumference in the proximal end portion of the connector main body 11 and an inner circumference in the proximal end portion of the movable sleeve 21 . More specifically, the accommodating portion 25 has a groove shape stretching in the circumferential direction around the outer circumferential surface in the proximal end portion of the cylindrical member 12 of the connector main body 11 .
[0110] In the embodiment, the accommodating portion 25 accommodates the elastic deformation member 24 therein so that the elastic deformation member 24 is able to be deformed inwardly in the direction of the diameter. The accommodating portion 25 has a dimension in the direction of the diameter (a groove depth) designed so that the elastic deformation member 24 is able to be deformed inwardly in the direction of the diameter by a certain amount. The dimension of the accommodating portion 25 in the direction of the diameter will be described later. Further, the accommodating portion 25 has a dimension in the direction of the axis designed so that the elastic deformation member 24 does not move in the direction of the axis while being deformed smoothly in the direction of the diameter. More specifically, the accommodating portion 25 has the dimension in the direction of the axis slightly larger than a dimension of the elastic deformation member 24 in the direction of the axis.
[0111] In the embodiment, the transmission unit 26 converts a force in the direction of the axis generated by moving the movable sleeve 21 from the initial position in a direction of the proximal end or in a direction of the distal end into a force in the direction of the diameter. Further, the transmission unit 26 transmits the force in the direction of the diameter thus converted to the elastic deformation member 24 for deforming the elastic deformation member 24 .
[0112] Additionally, the transmission unit 26 converts a force in the direction of the diameter generated when the elastic deformation member 24 thus deformed restores the shape thereof into a force in the direction of the axis. Further, the transmission unit 26 transmits the force in the direction of the axis thus converted to the movable sleeve 21 for bringing back the movable sleeve 21 from the proximal end or the distal end to the initial position. The transmission unit 26 includes at least two inclined surfaces 27 , 28 formed on an outer circumferential surface of the elastic deformation member 24 and a sliding contact portion 29 provided in the movable sleeve 21 .
[0113] As shown in FIG. 2 , the inclined surface 27 inclines by a predetermined angle toward outside in the direction of the diameter, from a middle portion to the distal end of the elastic deformation member 24 in the direction of the axis. Further, the inclined surface 27 extends around the entire outer circumferential surface of the elastic deformation member 24 .
[0114] In the embodiment, the inclined surface 28 inclines by a predetermined angle toward outside in the direction of the diameter, from the middle portion to the proximal end of the elastic deformation member 24 in the direction of the axis. The inclined surface 28 extends around the entire outer circumferential surface of the elastic deformation member 24 . With the inclined surfaces 27 and 28 , the elastic deformation member 24 has a shape constricted at the middle portion thereof in the direction of the axis.
[0115] In the embodiment, the sliding contact portion 29 protrudes from the inner circumference at a proximal end side of the movable sleeve 21 toward inside in the direction of the diameter. When the movable sleeve 21 is in the initial position, the sliding contact portion 29 is situated in a neutral position Po as shown in FIG. 2 . When the sliding contact portion 29 is in the neutral position Po, an end portion of the sliding contact portion 29 is close to or contacts with the middle portion of the elastic deformation member 24 where the inclined surfaces 27 and 28 contacts with each other. At this point, the elastic deformation member 24 is not deformed or is slightly deformed in the direction of the diameter inwardly due to the contact of the sliding contact portion 29 and the like.
[0116] When the movable sleeve 21 is moved from the initial position in a direction of the distal end, the sliding contact portion 29 is moved from the neutral position Po to a pressing position Pf. The end portion of the sliding contact portion 29 contacts slidingly with the inclined surface 27 of the elastic deformation member 24 as the sliding contact portion 29 is moved from the neutral position Po to the pressing position Pf. Thereby, the sliding contact portion 29 presses the inclined surface 27 of the elastic deformation member 24 . As a result, the elastic deformation member 24 is considerably deformed inwardly in the direction of the diameter.
[0117] When the movable sleeve 21 is moved from the initial position in a direction of the proximal end, the sliding contact portion 29 is moved from the neutral position Po to a pressing position Pb. The end portion of the sliding contact portion 29 contacts slidingly with the inclined surface 28 of the elastic deformation member 24 as the sliding contact portion 29 is moved from the neutral position Po to the pressing position Pb. Thereby, the sliding contact portion 29 presses the inclined surface 28 of the elastic deformation member 24 . As a result, the elastic deformation member 24 is considerably deformed inwardly in the direction of the diameter.
[0118] In the embodiment, the sliding contact portion 29 may extend around the entire inner circumference of the movable sleeve 21 as an elongated protrusion. The sliding contact portion 29 also may be divided into a plurality of protruding pieces arranged in the inner circumference of the movable sleeve 21 with a constant or inconstant interval in the circumferential direction.
[0119] Hereunder, relation about measurements of various portions in the electrical connector 1 at a proximal end portion thereof will be explained. As shown in FIG. 4 , when an inner diameter of the cylindrical member 12 where the accommodating portion 25 is situated is a; a thickness of the elastic deformation member 24 at the distal end portion or at the proximal end portion in the direction of the axis is b; and an inner diameter of the movable sleeve 21 where the sliding contact portion 29 is situated is c, relation among a, b and c satisfies a following expression (1):
[0000] c<a+ 2 b (1)
[0120] According to the expression (1) above, the movable sleeve 21 is controlled movement thereof in the direction of the axis, so that the diameter control portion 22 is able to admit or stop expanding the diameter of the fitting portion 17 appropriately. Consequently, it is possible to prevent the movable sleeve 21 from coming off the connector main body 11 due to the movement in the direction of the axis of the movable sleeve 21 beyond the control described above.
[0121] Therefore, as shown in FIG. 4 , when the relation among a, b and c satisfies the expression (1), the sliding contact portion 29 is pressed against the inclined surface 27 of the elastic deformation member 24 as the movable sleeve 21 moves in the direction of the distal end from the initial position. Accordingly, the elastic deformation member 24 is considerably deformed inwardly in the direction of the diameter.
[0122] When an inner circumferential surface of the elastic deformation member 24 thus deformed contacts with a bottom surface of the groove shape of the accommodating portion 25 , the sliding contact portion 29 abuts against the distal end of the inclined surface 27 of the elastic deformation member 24 . As a result, the movable sleeve 21 is not allowed to move further in the direction of the distal end. Similarly, when the movable sleeve 21 moves in the direction of the proximal end from the initial position, the sliding contact portion 29 is pressed against the inclined surface 28 of the elastic deformation member 24 .
[0123] When the inner circumferential surface of the elastic deformation member 24 thus deformed contacts with the bottom surface of the groove shape of the accommodating portion 25 , the sliding contact portion 29 abuts against the proximal end of the inclined surface 28 of the elastic deformation member 24 . As a result, the movable sleeve 21 is not allowed to move further in the direction of the proximal end.
[0124] The electrical connector 1 configured as described above is manufactured as described below. First, as shown in FIG. 2 , the central terminal 15 is attached to the cylindrical portion 13 with the supporting member 16 . Then the cylindrical portion 13 is inserted into the movable sleeve 21 from the proximal end of the movable sleeve 21 . At this time, the connecting portion 13 A of the cylindrical portion 13 is arranged so as to correspond to the sliding contact portion 29 . Next, the elastic deformation member 24 is inserted into the movable sleeve 21 from the proximal end of the movable sleeve 21 as being deformed inwardly in the direction of the axis.
[0125] In the embodiment, the elastic deformation member 24 is placed between the inner circumference of the movable sleeve 21 and an outer circumference of the connecting portion 13 A of the cylindrical portion 13 . Accordingly, the middle portion of the elastic deformation member 24 is situated at a corresponding position to the sliding contact portion 29 . Further, a distal end portion of the connecting portion 14 A of the cylindrical portion 14 is inserted into the movable sleeve 21 from the proximal end of the movable sleeve 21 .
[0126] At this time, the connecting portion 14 A is arranged so that the distal end portion of the connecting portion 14 A is situated into a space formed between the connecting portion 13 A of the cylindrical portion 13 and the elastic deformation member 24 . Then the connecting portion 14 thus arranged is inserted into the movable sleeve 21 . Thereby, the electrical connector 1 is assembled completely.
[0127] As described above, the cylindrical member 12 includes the cylindrical portion 13 and the cylindrical portion 14 . The cylindrical portion 13 provides a sidewall on a distal end side of the accommodating portion 25 and the cylindrical portion 14 provides a sidewall on the proximal end side of the accommodating portion 25 . The cylindrical portions 13 and 14 are connected to each other upon manufacturing the electrical connector 1 . Consequently, it is possible to easily manufacture the electrical connector 1 with the elastic deformation member 24 irremovable from the accommodating portion 25 .
[0128] FIGS. 5 and 6 show the mating connector 2 to be connected to the electrical connector 1 . As shown in FIGS. 5 and 6 , the mating connector 2 includes an outer cylindrical member 31 . The outer cylindrical member 31 forms an outer shell of the mating connector 2 . In addition, the outer cylindrical member 31 functions as an external terminal. The outer cylindrical member 13 is made from a metallic material and has a tiered cylindrical shape. Other end of the mating connector 2 is directly attached to, for example, a housing of a device, a circuit board and so on (not shown). The outer cylindrical member contacts electrically, for example, with a ground of the device, the circuit board and so on.
[0129] In the embodiment, the mating connector 2 includes a mating terminal 32 inside the outer cylindrical member 31 thereof. The mating terminal 32 contacts electrically, for example, with a signal line of the device, the circuit board and so on. The mating terminal 32 is fixed in a position of a central axis of the outer cylindrical member 31 with a supporting member 33 . The supporting member 33 is made from an insulating material such as a resin. The mating terminal 32 includes a contact hole 34 at a tip portion thereof. The tip portion of the central terminal 15 of the electrical connector 1 enters the contact hole 34 .
[0130] In the embodiment, the outer cylindrical member 31 includes an insertion portion 35 at a distal end portion thereof. The insertion portion 35 is inserted and fitted into the fitting portion 17 of the electrical connector 1 . The mating connector 2 further includes the engaged portion 36 . The engaged portion 36 is situated at a position being apart from a distal end of the insertion portion 35 by a predetermined distance in a direction of a proximal end portion. The engaged portion 36 is a depression surrounding an entire outer circumference of the insertion portion 35 . A shape of the depression corresponds to a shape of the engaging portion 20 provided on the inner circumference of the fitting portion 17 .
[0131] When the insertion portion 35 of the mating connector 2 is inserted into the fitting portion 17 of the electrical connector 1 as the movable sleeve 21 of the electrical connector 1 is moved in the direction of the distal end from the initial position, an outer circumference surface of the insertion portion 35 contacts slidingly with an end surface of the engaging portion 20 of the electrical connector 1 .
[0132] Further, the fitting portion 17 expands the diameter thereof when the insertion portion 35 of the mating connector 2 is inserted into the fitting portion 17 of the electrical connector 1 further. Furthermore, when the insertion portion 35 of the mating connector 2 reaches inside of the fitting portion 17 of the electrical connector 1 , the engaging portion 20 of the electrical connector 1 enters the engaged portion 36 of the mating connector 2 . Thereby the engaging portion 20 and the engaged portion 36 engage each other.
[0133] FIGS. 7(A) to 7(D) show a process of connecting the electrical connector 1 to the mating connector 2 . FIGS. 8(A) and 8(B) show a process of extracting the electrical connector 1 from the mating connector 2 .
[0134] As shown in FIG. 7(A) , when the electrical connector 1 is connected to the mating connector 2 , the operator holds the holding portion 23 of the movable sleeve 21 with the fingers. Then, the operator applies force so that the electrical connector 1 is pushed toward the mating connector 2 as the distal end portion of the fitting portion 17 of the electrical connector 1 and the distal end portion of the insertion portion 35 of the mating connector 2 contact with each other.
[0135] With the force described above, the movable sleeve 21 of the electrical connector 1 is moved in the direction of the distal end from the initial position. When the movable sleeve 21 of the electrical connector 1 is moved in the direction of the distal end from the initial position, the diameter control portion 22 is moved being apart from the outer circumferential surface of the distal end portion of the fitting portion 17 .
[0136] Therefore, the fitting portion 17 is allowed to expand the diameter thereof. In addition, as the movable sleeve 21 is moved as described above, the sliding contact portion 29 is moved from the neutral position Po to the pressing position Pf (refer to FIG. 2 ). Therefore, the end portion of the sliding contact portion 29 contacts slidingly with the inclined surface 27 of the elastic deformation member 24 . Thereby, the sliding contact portion 29 is pressed against the inclined surface 27 . As a result, the elastic deformation portion 24 is deformed inwardly in the direction of the diameter.
[0137] Next, as shown in FIG. 7(B) , when the operator pushes the electrical connector 1 toward the mating connector 2 further, the insertion portion 35 of the mating connector 2 enters the fitting portion 17 of the electrical connector 1 . As the insertion portion 35 of the mating connector 2 enters the fitting portion 17 of the electrical connector 1 further, the fitting portion 17 expands the diameter thereof.
[0138] As shown in FIG. 7(C) , when the insertion portion 35 of the mating connector 2 reaches inside of the fitting portion 17 of the electrical connector 1 , the central terminal 15 of the electrical connector 1 fits into the contact hole 34 of the mating terminal 32 of the mating connector 2 . Additionally, the engaging portion 20 engages the engaged portion 36 . The operator recognizes the electrical connector 1 is connected to the mating connector 2 certainly, with sound and vibration generated as the engaging portion 20 engages the engaged portion 36 .
[0139] Next, as shown in FIG. 7(D) , as the fingers of the operator are taken off from the holding portion 23 of the movable sleeve 21 , the force moving the movable sleeve 21 toward the distal end from the initial position disappears. Accordingly, the force deforming the elastic deformation member 24 inwardly in the direction of the diameter also disappears. Therefore, the elastic deformation member 24 restores the shape thereof to an initial shape with the elasticity thereof.
[0140] For this reason, a force restoring the shape of the elastic deformation member 24 is applied to the sliding contact portion 29 of the movable sleeve 21 toward outside in the direction of the diameter, since the sliding contact portion 29 abuts against the inclined surface 27 of the elastic deformation member 24 . Therefore, the sliding contact portion 29 is pushed toward the proximal end in the direction of the axis. Consequently, the movable sleeve 21 thus pushed to the distal end side returns to the initial position thereof as the sliding contact portion 29 returns from the pressing position Pf to the neutral position Po (refer to FIG. 2 ).
[0141] When the movable sleeve 21 returns to the initial position, the diameter control portion 22 comes closer to the outer circumferential surface of the distal end portion of the fitting portion 17 . Thereby, the fitting portion 17 is not allowed to expand the diameter thereof. Accordingly, the engaging portion 20 of the electrical connector 1 is fixed in a state of engaging the engaged portion 36 of the mating connector 2 . As a result, the electrical connector 1 and the mating connector 2 are locked as connecting to each other.
[0142] Next, as shown in FIG. 8(A) , when the electrical connector 1 is extracted from the mating connector 2 , the operator holds the holding portion 23 of the movable sleeve 21 with the fingers and applies force so that the electrical connector 1 is pulled so as to be apart from the mating connector 2 .
[0143] With the force described above, the movable sleeve 21 of the electrical connector 1 is moved in the direction of the proximal end from the initial position. When the movable sleeve 21 of the electrical connector 1 is moved in the direction of the proximal end from the initial position, the diameter control portion 22 is moved so as to be apart from the distal end portion of the fitting portion 17 . Thereby, the electrical connector 1 and the mating connector 2 are unlocked since the fitting portion 17 is allowed to expand the diameter thereof.
[0144] Further, as the movable sleeve 21 is moved as described above, the sliding contact portion 29 is moved from the neutral position Po to the pressing position Pb (refer to FIG. 2 ). Therefore, the end portion of the sliding contact portion 29 contacts slidingly with the inclined surface 28 of the elastic deformation member 24 . Thereby, the sliding contact portion 29 is pressed against the inclined surface 28 of the elastic deformation member 24 . As a result, the elastic deformation portion 24 is deformed inwardly in the direction of the diameter.
[0145] Next, as shown in FIG. 8(B) , when the operator pulls the electrical connector 1 so as to be apart from the mating connector 2 further, the engaging portion 20 of the electrical connector 1 expands the diameter of the fitting portion 17 , being removed from the engaged portion 36 of the mating connector 2 . As a result, the central terminal 15 of the electrical connector 1 comes off the contact hole 34 of the mating terminal 32 of the mating connector 2 . Further, the insertion portion 35 of the mating connector 2 is pulled out of the fitting portion 17 of the electrical connector 1 . Thereby, the electrical connector 1 is extracted from the mating connector 2 .
[0146] When the electrical connector 1 is extracted from the mating connector 2 , the force moving the movable sleeve 21 toward the proximal end disappears. Accordingly, the force deforming the elastic deformation member 24 inwardly in the direction of the diameter also disappears. Therefore, the elastic deformation member 24 restores the shape thereof to the initial shape with the elasticity thereof.
[0147] For this reason, a force restoring the shape of the elastic deformation member 24 is applied to the sliding contact portion 29 of the movable sleeve 21 toward outside in the direction of the diameter, since the sliding contact portion 29 abuts against the inclined surface 28 of the elastic deformation member 24 . Therefore, the sliding contact portion 29 is pushed toward the distal end in the direction of the axis. Consequently, the movable sleeve 21 thus pushed to the proximal end side returns to the initial position thereof as the sliding contact portion 29 returns from the pressing position Pb to the neutral position Po (refer to FIG. 2 ).
[0148] As described above, according to the first embodiment of the present invention, the electrical connector 1 enables to obtain a function which automatically returns the movable sleeve 21 to the initial position with a simple configuration such that arranging the elastic deformation member 24 between the movable sleeve 21 and the connector main body 11 . Consequently, as compared to the case that having a coiled spring or having the movable sleeve capable of elastic deformation as a mechanism for returning automatically the movable sleeve to the initial position, the electrical connector 1 is able to have lesser dimension in the direction of the axis. As a result, it enables the electrical connector 1 to be downsized.
[0149] In addition, according to the first embodiment of the present invention, the electrical connector 1 enables to increase rigidity of the movable sleeve 21 thereof, since it is not necessary to deform the movable sleeve 21 elastically. Accordingly, it is possible to prevent the movable sleeve 21 from deformation or being damaged due to being twisted forcibly and the like. Consequently, the electrical connector 1 is able to obtain higher durability.
Second Embodiment
[0150] A second embodiment of the present invention will be explained next. FIG. 9 is a sectional view showing an electrical connector according to a second embodiment of the present invention. In FIG. 9 , components unchanged from the first embodiment have the same numeral references as FIGS. 1 to 8(B) and explanations thereof will be omitted.
[0151] As shown in FIG. 9 , the electrical connector 41 according to the second embodiment of the present invention includes an elastic deformation member 42 ; an accommodating portion 43 and a transmission unit 44 as the mechanism for returning the movable sleeve 21 moved by the operator in the direction of the axis to the initial position automatically. The accommodating portion 43 accommodates the elastic deformation member 42 and the transmission unit 44 generates force bringing back the movable sleeve 21 to the initial position by utilizing elastic force of the elastic deformation member 42 .
[0152] The elastic deformation member 42 is made from a resin material and has a C-letter shape as a whole. The elastic deformation member 42 is capable of being deformed with elasticity thereof in a direction of a diameter thereof. These aspects are the same as aspects of the elastic deformation member 24 in the first embodiment.
[0153] The accommodating portion 43 is situated between the outer circumference in the proximal end portion of the connector main body 11 and the inner circumference in the proximal end portion of the movable sleeve 21 . The accommodating portion 43 includes grooves 43 A and 43 B. The groove 43 A stretches in the circumferential direction around the outer circumferential surface in the proximal end portion of the cylindrical member 12 of the connector main body 11 .
[0154] In the embodiment, the groove 43 B stretches in the circumferential direction around an inner circumferential surface in the proximal end portion of the movable sleeve 21 so as to face the groove 43 A. The accommodating portion 43 accommodates the elastic deformation member 42 therein so that the elastic deformation member 42 is able to be deformed toward inside in the direction of the diameter while being disabled to be moved in the direction of the axis.
[0155] In the embodiment, the transmission unit 44 converts the force in the direction of the axis generated by moving the movable sleeve 21 from the initial position in the direction of the proximal end or in the direction of the distal end into the force in the direction of the diameter. Further, the transmission unit 44 transmits the force in the direction of the diameter thus converted to the elastic deformation member 42 for deforming the elastic deformation member 42 .
[0156] Additionally, the transmission unit 44 converts the force in the direction of the diameter generated when the elastic deformation member 42 thus deformed restores the shape thereof into the force in the direction of the axis. Further, the transmission unit 44 transmits the force in the direction of the axis thus converted to the movable sleeve 21 for bringing back the movable sleeve 21 from the proximal end or the distal end to the initial position. The transmission unit 44 includes at least two inclined surfaces 45 and 46 formed on the outer circumferential surface of the elastic deformation member 42 and two sliding contact portions 47 and 48 provided in the movable sleeve 21 .
[0157] In the embodiment, the inclined surface 45 inclines by a predetermined angle toward inside in the direction of the diameter, from the middle portion to the distal end portion of the elastic deformation member 42 in the direction of the axis. The inclined surface 45 extends around the entire outer circumferential surface of the elastic deformation member 42 .
[0158] In the embodiment, the inclined surface 46 inclines by a predetermined angle toward inside in the direction of the diameter, from the middle portion to the proximal end portion of the elastic deformation member 42 in the direction of the axis. The inclined surface 46 extends around the entire outer circumferential surface of the elastic deformation member 42 .
[0159] In the embodiment, the elastic deformation member 42 has a shape expanded at the middle portion thereof in the direction of the axis, with the inclined surfaces 45 and 46 . Hereunder, a portion of the elastic deformation member 42 thus expanded in the middle portion thereof in the direction of the axis is called an expanded portion 42 A.
[0160] In the embodiment, the sliding contact portions 47 and 48 are provided in the inner circumference at a proximal end side of the movable sleeve 21 . The sliding contact portions 47 and 48 are situated in positions corresponding to the inclined surfaces 45 and 46 of the elastic deformation member 42 , respectively.
[0161] More specifically, the sliding contact portion 47 is provided in a circumferential end portion at the distal end in the direction of the axis of the groove 43 B formed in the inner circumferential surface in the proximal end portion of the movable sleeve 21 . Similarly, the sliding contact portion 48 is provided in the circumferential end portion at the proximal end in the direction of the axis of the groove 43 B formed in the inner circumferential surface in the proximal end portion of the movable sleeve 21 .
[0162] When the movable sleeve 21 is in the initial position, the expanded portion 42 A of the elastic deformation member 42 is situated between the sliding contact portions 47 and 48 . Further, end portions of the sliding contact portions 47 and 48 are close to or contact with the inclined surfaces 45 and 46 , respectively. At this point, the elastic deformation member 42 is not deformed; is slightly deformed inwardly in the direction of the diameter due to contact of an end portion of the expanded portion 42 A with a bottom surface of the groove 43 B; or is slightly deformed inwardly in the direction of the diameter due to contact of the sliding contact portions 47 and 48 with the inclined surface 45 and 46 , respectively.
[0163] When the operator holds the holding portion 23 of the movable sleeve 21 with the fingers and applies force so that the movable sleeve 21 is pushed toward the distal end in the direction of the axis, the movable sleeve 21 is moved in the direction of the distal end from the initial position. Therefore, the sliding contact portion 48 is moved toward the distal end in the direction of the axis, contacting slidingly with the inclined surface 46 .
[0164] As a result, the elastic deformation member 42 is considerably deformed inwardly in the direction of the diameter since the inclined surface 46 is pushed against the sliding contact portion 48 . Further, when the fingers of the operator are taken off from the holding portion 23 of the movable sleeve 21 , a force toward outside in the direction of the diameter to restore the shape of the elastic deformation member 42 is applied to the sliding contact portion 48 which is in contact with the inclined surface 46 . Therefore, the sliding contact portion 48 is pushed toward the proximal end in the direction of the axis. Consequently, the movable sleeve 21 at the distal end side returns to the initial position thereof.
[0165] In addition, when the operator holds the holding portion 23 of the movable sleeve 21 with the fingers and applies force so that the movable sleeve 21 is pushed toward the proximal end in the direction of the axis, the movable sleeve 21 is moved in the direction of the proximal end from the initial position. Therefore, the sliding contact portion 47 is moved toward the proximal end in the direction of the axis, contacting slidingly with the inclined surface 45 .
[0166] As a result, the elastic deformation member 42 is considerably deformed inwardly in the direction of the diameter since the inclined surface 45 is pushed against the sliding contact portion 47 . Further, when the fingers of the operator are taken off from the holding portion 23 of the movable sleeve 21 , a force toward inside in the direction of the diameter to restore the shape of the elastic deformation member 42 is applied to the sliding contact portion 47 which is in contact with the inclined surface 45 . Therefore, the sliding contact portion 47 is pushed toward the distal end in the direction of the axis. Consequently, the movable sleeve 21 at the distal end side returns to the initial position thereof.
[0167] It is possible that the electrical connector 41 according to the second embodiment of the invention is able to obtain the same functionality and effect with the electrical connector 1 in the first embodiment of the present invention.
Third Embodiment
[0168] A third embodiment of the present invention will be explained next. FIG. 10 is a sectional view showing an electrical connector according to a third embodiment of the present invention. In FIG. 10 , components unchanged from the first embodiment have the same numeral references as FIGS. 1 to 8(B) and explanations thereof will be omitted.
[0169] As shown in FIG. 10 , the electrical connector 51 according to the third embodiment of the present invention includes an elastic deformation member 52 as a part of the mechanism for returning the movable sleeve 21 moved by the operator in the direction of the axis to the initial position automatically. In the embodiment, the elastic deformation member 52 is made from a metallic material by press working.
[0170] In the embodiment, the elastic deformation member 52 has a C-letter shape as a whole. The elastic deformation member 52 is capable of being deformed with elasticity thereof in the direction of the diameter thereof. The elastic deformation member 52 includes inclined surfaces 53 and 54 in the outer circumferential surface thereof.
[0171] In the embodiment, the inclined surface 53 inclines from the middle portion of the elastic deformation portion 52 to the distal end portion in the direction of the axis, and toward outside in the direction of a diameter. The inclined surface 54 inclines from the middle portion of the elastic deformation portion 52 to the proximal end portion in the direction of the axis, and toward outside in the direction of a diameter. Other configuration of the electrical connector 51 is the same with the configuration of the electrical connector 1 in the first embodiment of the present invention.
[0172] In addition, the electrical connector 51 has the same function with the electrical connector 1 in the first embodiment of the present invention, that is, the function to move the movable sleeve 21 to the initial position automatically, utilizing the force toward outside in the direction of the diameter generated as the elastic deformation member 52 restores the shape thereof after deformed inwardly in the direction of the diameter.
[0173] It is possible that the electrical connector 51 according to the third embodiment of the invention is able to obtain the same functionality and effect with the electrical connector 1 in the first embodiment of the present invention.
Fourth Embodiment
[0174] A fourth embodiment of the present invention will be explained next. FIG. 11 is a sectional view showing an electrical connector according to a fourth embodiment of the present invention. In FIG. 11 , components unchanged from the first embodiment have the same numeral references as FIGS. 1 to 8(B) and explanations thereof will be omitted.
[0175] As shown in FIG. 11 , the electrical connector 61 according to the fourth embodiment of the present invention includes an elastic deformation member 62 made from a resin material and has a C-letter shape as a whole. The elastic deformation member 62 is capable of being deformed outwardly in the direction of the diameter with elasticity thereof. Further, the electrical connector 61 further includes an accommodating portion 63 for accommodating the elastic deformation member 62 . The accommodating portion 63 has a groove shape stretching in the circumferential direction in the inner surface of the movable sleeve 21 at the proximal end portion.
[0176] Furthermore, the electrical connector 61 includes a transmission unit 64 for generating a force bringing back the movable sleeve 21 to the initial position by utilizing elastic force of the elastic deformation member 62 . The transmission unit 64 includes at least inclined surfaces 65 and 66 , a sliding contact portion 67 .
[0177] In other words, the elastic deformation member 62 includes the inclined surfaces 65 and 66 formed on the inner circumference of the elastic deformation member 62 . The inclined surface 65 inclines from the middle portion of the elastic deformation portion 62 to the distal end portion in the direction of the axis, and toward inside in the direction of a diameter.
[0178] In the embodiment, the inclined surface 66 inclines from the middle portion of the elastic deformation portion 62 to the proximal end portion in the direction of the axis, and toward inside in the direction of a diameter. Further, the sliding contact portion 67 is provided in the outer circumferential surface at the proximal end side of the cylindrical member 12 of the connector main body 11 . The sliding contact portion 67 extends toward outside in the direction of the diameter.
[0179] In the embodiment, the sliding contact portion 67 may extend around the entire outer circumference at the proximal end side of the cylindrical member 12 as an elongated protrusion. The sliding contact portion 67 also may be divided into a plurality of protruding pieces arranged in the outer circumference at the proximal end side of the cylindrical member 12 with a constant or inconstant interval in the circumferential direction.
[0180] When the movable sleeve 21 is in the initial position, an end portion of the sliding contact portion 67 is close to or contacts with the middle portion in the direction of the axis of the elastic deformation member 62 , where the inclined surfaces 65 and 66 contacts with each other. At this point, the elastic deformation member 62 is not deformed or is slightly deformed in the direction of the diameter outwardly.
[0181] When the operator holds the holding portion 23 of the movable sleeve 21 with the fingers and applies force so that the movable sleeve 21 is pushed toward the distal end in the direction of the axis, the movable sleeve 21 is moved in the direction of the distal end from the initial position. Therefore, the elastic deformation portion 62 is moved in the direction of the distal end.
[0182] Accordingly, the sliding contact portion 67 contacts slidingly with the inclined surface 66 . Thereby, the sliding contact portion 67 presses the inclined surface 66 . As a result, the elastic deformation member 62 is considerably deformed outwardly in the direction of the diameter. Further, when the fingers of the operator are taken off from the holding portion 23 of the movable sleeve 21 , a force toward inside in the direction of the diameter for restoring the shape of the elastic deformation member 62 is applied to the sliding contact portion 67 which is in contact with the inclined surface 66 . Therefore, the sliding contact portion 67 is pushed toward the proximal end in the direction of the axis. Consequently, the movable sleeve 21 moved to the distal end side returns to the initial position thereof.
[0183] In addition, when the operator holds the holding portion 23 of the movable sleeve 21 with the fingers and applies force so that the movable sleeve 21 is pushed toward the proximal end in the direction of the axis, the movable sleeve 21 is moved in the direction of the proximal end from the initial position. Therefore, the elastic deformation portion 62 is moved in the direction of the proximal end. Accordingly, the sliding contact portion 67 contacts slidingly with the inclined surface 65 . Thereby, the sliding contact portion 67 presses the inclined surface 65 . As a result, the elastic deformation member 62 is considerably deformed outwardly in the direction of the diameter.
[0184] Further, when the fingers of the operator are taken off from the holding portion 23 of the movable sleeve 21 , a force toward inside in the direction of the diameter for restoring the shape of the elastic deformation member 62 is applied to the sliding contact portion 67 which is in contact with the inclined surface 65 . Therefore, the sliding contact portion 67 is pushed toward the distal end in the direction of the axis. Consequently, the movable sleeve 21 moved to the proximal end side returns to the initial position thereof.
[0185] It is possible that the electrical connector 61 according to the fourth embodiment of the invention is able to obtain the same functionality and effect with the electrical connector 1 in the first embodiment of the present invention.
Fifth Embodiment
[0186] A fifth embodiment of the present invention will be explained next. FIG. 12 is a sectional view showing an electrical connector according to a fifth embodiment of the present invention. In FIG. 12 , components unchanged from the first embodiment have the same numeral references as FIGS. 1 to 8(B) and explanations thereof will be omitted.
[0187] As shown in FIG. 12 , the electrical connector 71 according to the fifth embodiment of the present invention includes an elastic deformation member 72 . In the embodiment, the elastic deformation member 72 is made from a resin material and has a C-letter shape as a whole. The elastic deformation member 72 is capable of being deformed with elasticity thereof in the direction of the diameter thereof outwardly. An accommodating portion 73 for accommodating the elastic deformation member 72 therein includes grooves 73 A and 73 B.
[0188] In the embodiment, the groove 73 A stretches in the circumferential direction around the outer circumferential surface in the proximal end portion of the cylindrical member 12 of the connector main body 11 . The groove 73 B stretches in the circumferential direction around an inner circumferential surface in the proximal end portion of the movable sleeve 21 so as to face the groove 73 A.
[0189] In the embodiment, the transmission unit 74 generates the force to move the movable sleeve 21 to the initial position, utilizing the elasticity of the elastic deformation member 72 . The transmission unit 74 includes at least inclined surfaces 75 and 76 and sliding contact portions 77 and 78 . That is, elastic deformation member 72 includes the inclined surfaces 75 and 76 on an inner circumference thereof.
[0190] In the embodiment, the inclined surface 75 inclines from the middle portion to the distal end portion of the elastic deformation member 72 in the direction of the axis, toward outside in the direction of the diameter. The inclined surface 76 inclines from the middle portion to the proximal end portion of the elastic deformation member 72 in the direction of the axis, toward outside in the direction of the diameter.
[0191] In the embodiment, the elastic deformation member 72 has a shape expanded at the middle portion thereof inwardly in the direction of the axis, with the inclined surfaces 75 and 76 . Hereunder, a portion of the elastic deformation member 72 thus expanded in the middle portion thereof in the direction of the axis is called an expanded portion 72 A. Further, the cylindrical member 12 of the connector main body 11 includes a groove 73 A in the inner circumference in the proximal end portion thereof. The sliding contact portion 77 is provided in a circumferential end portion at the distal end in the direction of the axis of the groove 73 A. The sliding contact portion 78 is provided in the circumferential end portion at the proximal end in the direction of the axis of the groove 73 A.
[0192] When the movable sleeve 21 is in the initial position, the expanded portion 72 A of the elastic deformation member 72 is situated between the sliding contact portions 77 and 78 . Further, end portions of the sliding contact portions 77 and 78 are close to or contact with the inclined surfaces 75 and 76 , respectively. At this point, the elastic deformation member 72 is not deformed; is slightly deformed in the direction of the diameter inwardly due to contact of an end portion of the expanded portion 72 A with a bottom surface of the groove 73 A; or is slightly deformed in the direction of the diameter inwardly due to contact of the sliding contact portions 77 and 78 with the inclined surface 75 and 76 , respectively.
[0193] When the operator holds the holding portion 23 of the movable sleeve 21 with the fingers and applies force so that the movable sleeve 21 is pushed toward the distal end, the movable sleeve 21 is moved in the direction of the distal end from the initial position. Therefore, the sliding contact portion 77 is moved toward the distal end in the direction of the axis, contacting slidingly with the inclined surface 75 . As a result, the elastic deformation member 72 is considerably deformed outwardly in the direction of the diameter since the inclined surface 75 is pushed against the sliding contact portion 77 .
[0194] Further, when the fingers of the operator are taken off from the holding portion 23 of the movable sleeve 21 , a force toward inside in the direction of the diameter to restore the shape of the elastic deformation member 72 is applied to the sliding contact portion 77 which is in contact with the inclined surface 75 . Therefore, the sliding contact portion 77 is pushed toward the proximal end in the direction of the axis. Consequently, the movable sleeve 21 moved to the distal end side returns to the initial position thereof.
[0195] In addition, when the operator holds the holding portion 23 of the movable sleeve 21 with the fingers and applies force so that the movable sleeve 21 is pushed toward the proximal end, the movable sleeve 21 is moved in the direction of the proximal end from the initial position. Therefore, the sliding contact portion 78 is moved toward the proximal end in the direction of the axis, contacting slidingly with the inclined surface 76 . As a result, the elastic deformation member 72 is considerably deformed outwardly in the direction of the diameter since the inclined surface 76 is pushed against the sliding contact portion 78 .
[0196] Further, when the fingers of the operator are taken off from the holding portion 23 of the movable sleeve 21 , a force toward inside in the direction of the diameter to restore the shape of the elastic deformation member 72 is applied to the sliding contact portion 78 which is in contact with the inclined surface 76 . Therefore, the sliding contact portion 78 is pushed toward the distal end in the direction of the axis. Consequently, the movable sleeve 21 moved to the proximal end side returns to the initial position thereof.
[0197] It is possible that the electrical connector 71 according to the fifth embodiment of the invention is able to obtain the same functionality and effect with the electrical connector 1 in the first embodiment of the present invention.
Sixth Embodiment
[0198] A sixth embodiment of the present invention will be explained next. FIG. 13 is a sectional view showing a pair of electrical connectors according to a sixth embodiment of the present invention. The pair of the electrical connectors includes a first electrical connector 81 (a first connector) and a second electrical connector 82 (a second connector) connected to each other.
[0199] The first connector 81 includes a cylindrical member 83 having a cylindrical shape; a central terminal 85 extending in the direction of the axis and fixed in the cylindrical member 83 with a supporting member 84 ; and a fitting portion 86 at a distal end portion of the cylindrical member 83 , for receiving the second connector 82 upon being connected to the second connector 82 .
[0200] In the embodiment, the fitting portion 86 is capable of expanding a diameter thereof elastically. Furthermore, the fitting portion 86 includes an engaging portion 87 in an inner circumference thereof. When the second connector 82 is inserted into the fitting portion 86 , the fitting portion 86 expands the diameter thereof. Thereby the second connector 2 is able to be inserted into the fitting portion 86 further. When the second connector 82 is completely inserted into the fitting portion 86 , the engaging portion 87 engages an engaged portion 95 provided in the second connector 82 as the fitting portion 86 restores a shape thereof to an initial shape.
[0201] In addition, the cylindrical member 83 further includes a reinforcement guide 88 on an outer circumference thereof. The reinforcement guide 88 has a cylindrical shape.
[0202] The second connector 82 is substantially configured with a connector main body 89 and a movable sleeve 90 . The movable sleeve 90 is able to move against the connector main body 89 in the direction of the axis.
[0203] The connector main body 89 includes a cylindrical member 91 having a cylindrical shape and a central terminal 93 fixed in the cylindrical member 91 at the proximal side of the cylindrical member 91 with a supporting member 92 . The central terminal 93 extends in the direction of the axis. Furthermore, the cylindrical member 91 includes an insertion portion 94 at a distal end portion thereof.
[0204] In the embodiment, the insertion portion 94 is inserted and fitted into the fitting portion 86 of the first connector 81 . The second connector 82 further includes the engaged portion 95 . The engaged portion 95 is situated at the proximal end on an outer circumferential surface of the insertion portion 94 of the cylindrical member 91 .
[0205] In the embodiment, the movable sleeve 90 is formed in a cylindrical shape. The movable sleeve 90 includes diameter control portions 96 and 97 in a distal end portion and a middle portion thereof in the direction of the axis, respectively. The diameter control portions 96 and 97 control expansion of a diameter of the fitting portion 86 of the first connector 81 .
[0206] When a distal end portion of the fitting portion 86 of the first connector 81 and a distal end portion of the insertion portion 94 of the second connector 82 contact with each other upon connecting the first connector 81 and the second connector 82 to each other, the diameter control portion 96 comes close or abuts to an outer circumference of the fitting portion 86 in a case that the movable sleeve 90 is situated in an initial position in the direction of the axis.
[0207] In the case described above, the fitting portion 86 is not allowed to expand the diameter thereof at the distal end. When the movable sleeve 90 is moved from the initial position to the distal end, the diameter control portion 96 becomes apart from the outer circumference of the fitting portion 86 . Thereby, the fitting portion 86 is allowed to expand the diameter thereof.
[0208] In addition, when the insertion portion 94 of the second connector 82 is inserted completely into the fitting portion 86 of the first connector 81 and the first connector 81 and the second connector 82 are connected to each other, in other words, when the engaging portion 87 engages the engaged portion 95 , the diameter control portion 97 comes close or abuts to the outer circumference of the fitting portion 86 in a case that the movable sleeve 90 is situated in the initial position in the direction of the axis.
[0209] In the case described above, the fitting portion 86 is not allowed to expand the diameter thereof at the distal end. When the movable sleeve 90 is moved to the proximal end, the diameter control portion 97 becomes apart from the outer circumference of the fitting portion 86 . Thereby, the fitting portion 86 is allowed to expand the diameter thereof.
[0210] The second connector 82 includes an elastic deformation member 98 ; an accommodating portion 99 ; and a transmission unit 100 as a mechanism for enabling the movable sleeve 90 moved in the direction either of the proximal end or the distal end to return automatically to the initial position. The accommodating portion 99 accommodates the elastic deformation member 98 and the transmission unit 100 generates force bringing back the movable sleeve 90 to the initial position by utilizing elastic force of the elastic deformation member 98 .
[0211] In the embodiment, the elastic deformation member 98 and accommodating portion 99 have the same configurations as the elastic deformation member 24 and accommodating portion 25 in the first embodiment, respectively. Further, the transmission unit 100 at least includes two inclined surfaces 101 and 102 formed on an outer circumference of the elastic deformation member 98 and a sliding contact portion 103 provided in the movable sleeve 90 having the same configurations with the inclined surfaces 27 and 28 and sliding contact portion 29 in the first embodiment of the present invention, respectively.
[0212] It is possible that the pair of the electrical connectors according to the sixth embodiment of the invention is able to obtain the same functionality and effect with the electrical connector 1 in the first embodiment of the present invention.
[0213] In the embodiments described above, according to the present invention, each of the electrical connectors 1 , 41 , 51 , 61 , 71 , 81 and 82 is a coaxial connector having a single central terminal 15 , 85 or 93 . Electrical connectors according to the present invention are not limited to the electrical connectors described above. An electrical connector according to the present invention may be a multi core connector having a plurality of terminals in an inner circumference of an external terminal.
[0214] Furthermore, in the embodiments described above, according to the present invention, each of the electrical connectors 1 , 41 , 51 , 61 , 71 , 81 and 82 has a circular cross-sectional shape. The present invention is applicable to an electrical connector having a polygonal cross-sectional shape, for example, a tetragonal cross-sectional shape, not limited to the circular cross-sectional shape.
[0215] Additionally, as shown in FIG. 14 , a mating connector 111 may include a reinforcement guide 112 . The reinforcement guide 112 has a cylindrical shape. The reinforcement guide 112 is settled so as to surround an entire outer circumference in a distal end portion of the movable sleeve 21 of the electrical connector 1 when the electrical connector 1 is connected to the mating connector 111 . The reinforcement guide 112 protects the electrical connector 1 and the mating connector 111 from an external force applied to the electrical connector 1 and the mating connector 111 due to being twisted forcibly and the like. Consequently, the electrical connector 1 and the mating connector 111 are able to obtain higher durability.
[0216] Furthermore, as shown in FIG. 15 , a mating connector 121 may include a bulging portion 124 situated next to an engaged portion 123 in a distal end portion of an outer cylindrical member 122 . The bulging portion 124 bulges outwardly in the direction of the diameter throughout an entire outer circumference of the outer cylindrical member 122 . An outer diameter of the distal end portion of the outer cylindrical member 122 is smaller than an outer diameter of the insertion portion 35 of the outer cylindrical member 31 shown in FIGS. 5 and 6 .
[0217] With the configuration as described above, it is also possible to enable the fitting portion 17 to expand the diameter thereof since the bulging portion 124 pushes the engaging portion 20 outwardly in the direction of the diameter as the mating connector 121 enters the fitting portion 17 of the electrical connector 1 . When the mating connector 121 completely enters the fitting portion 17 of the electrical connector 1 , the fitting portion 17 is allowed to shrink the diameter thereof so as to obtain an initial shape. Therefore, it is possible for the engaging portion 20 to engage the engaged portion 123 of the mating connector 121 .
[0218] In the embodiments described above, the present invention is applied to an electrical connector. It is possible to apply the present invention to an optical connector having an optical signal terminal, not limited to the embodiments described above.
[0219] Moreover, the present invention is able to modify as far as the modification is within the inventive concept readable from the claims and the specification as a whole. Therefore, the connector thus modified also falls within the inventive concept of the present invention.
[0220] The disclosure of Japanese Patent Application No. 2011-069657 filed on Mar. 28, 2011, is incorporated in the application by reference.
[0221] While the invention has been explained with reference to the specific embodiments of the invention, the explanation is illustrative and the invention is limited only by the appended claims. | A connector to be connected to a mating connector, includes a connector main body including a cylindrical member, a supporting member disposed in the cylindrical member, a terminal supported on the supporting member, and a fitting portion having an engaging portion; a movable sleeve including a diameter control portion; an elastic deformation member disposed to be elastically deformable in a radial direction thereof; an accommodating portion disposed between the connector main body and the movable sleeve for accommodating the elastic deformation member; and a transmission unit for transmitting a force in the axial direction from the movable sleeve to the elastic deformation member when the movable sleeve moves, and for transmitting a force in the radial direction from the elastic deformation member to the movable sleeve when the elastic deformation member returns to an original shape. | 7 |
BACKGROUND OF THE INVENTION
The invention relates to the field of lasers and more particularly to the field of plasma excitation-recombination lasers.
Applicants have demonstrated that recombination lasers could be generated in the recombining plasma of a laser-vaporized metal (Cd) by use of the relatively low energy (as low as 0.5 mJ) output of focused lasers. This work was documented in an article entitled, "Recombination Lasers in Nd and CO 2 Laser-Produced Cadmium Plasmas", by W. T. Silfvast, L. H. Szeto and O. R. Wood II, Optics Letters, September, 1979, Vol. 4, No. 9, pp. 271-273. This result was obtained by allowing the laser-produced plasma of the target material to expand into a low pressure background gas which provided control of the plasma expansion and increased the electron cooling rate, thereby increasing the recombination rate. Further work by applicants has indicated that segmentation of the plasma in the focal region where it is produced by cylindrical focusing is significantly more effective in generating a recombination laser in xenon gas than is the generation of the plasma by a continuous line focus. A 24-fold increase in Xe laser output was obtained for the segmented focus plasma as compared to the continuous line focus plasma for the same input energy. This increase was attributed to the larger volume of cool gas surrounding the plasmas which allowed greater plasma expansion and thereby increased the plasma recombination rate. This work was documented in an article entitled, "Ultra-High-Gain Laser-Produced Plasma Laser in Xenon Using Periodic Pumping" by N. T. Silfvast, L. H. Szeto and O. R. Wood II, Applied Physics Letters, Vol. 34, No. 3, Feb. 1, 1979, pp. 213-215.
SUMMARY OF THE INVENTION
A high-voltage, high current pulse is applied to a series of two or more conducting strips installed in series in an enclosure containing a laser cavity and either a buffer gas or a vacuum. The strips are separated by small gaps. When the high-voltage, high-current pulse is applied to the strips, plasmas are formed in the gap regions. The plasmas are comprised of ions from the strip material. Once formed, these plasmas expand hemispherically, cool and recombine to provide laser action. The composition of the plasmas depends on the strip material, the electric field in the gaps, the gap size and the background gas type and pressure.
BRIEF DESCRIPTION OF THE DRAWING
A complete understanding of the present invention may be gained from a consideration of the following detailed description presented hereinbelow in connection with the accompanying drawings in which:
FIG. 1 shows, in schematic form, an embodiment of the present invention utilizing Cd metal strips; and
FIG. 2 shows an oscilloscope trace of 1.433 μm output from a segmented plasma recombination laser in cadmium produced by discharging a 0.01 μF capacitor initially charged to 18 kV; helium is utilized as a background gas at 3 Torr.
DETAILED DESCRIPTION
An embodiment of the present invention used for the production of a segmented plasma-excitation and recombination (SPER) laser in Cd vapor is shown in FIG. 1. Ten cadmium strips 101-110, each being 1 mm thick by 2 mm wide by 10 mm long, were positioned end to end on a 6 inch long glass plate, 120, in such a manner as to leave a 1 mm gap between each pair of strips. This electrode arrangement was then installed in a gas cell, (not shown in FIG. 1). Capacitor 130, 0.01 μF, was charged to 21 kV and then discharged across the series of metal strips with a spark gap. The resultant 840 A current pulse had a ringing frequency of 1.2 MHz and produced a bright metal vapor plasma in each gap. Areas 141-149 in FIG. 1 depict the shape of the plasmas after they had expanded hemispherically outward from the gaps into a background gas of helium at 5 Torr. The areas depicted correspond to a 1 cm diameter volume. The appearance of each individual plasma was found to be similar to that produced by the focused output from pulsed Nd or CO 2 lasers on Cd targets.
Two dielectric mirrors, 150 and 151, coated for maximum reflectivity between 1.35 and 1.53 μm and having a 3 meter radius of curvature formed a 9 inch long resonator for the 1.43 μm laser radiation. The optical axis, 160, of this resonator was positioned parallel to and 7 mm above the row of cadmium strips. The output from this resonator, shown as arrow 170, was focused through suitable filters onto a room temperature Ge diode.
Glass plate 120 is not essential to operation of the laser. In fact, glass plate 120 can be eliminated without significantly affecting the laser output. It does, however, function as a structural support for the electrodes and can control the direction of plasma expansion to some extent.
Using a similar arrangement to that shown in FIG. 1, we have made SPER lasers in the near infrared at wavelengths between 0.94 and 1.84 μm in the eight elements listed in Table I. The table also lists the observed wavelengths, the transition assignment and the relative power outputs for these elements. The measured wavelengths have been identified with a transition in the neutral spectrum of the element. In every case the oscillating transitions occur between levels immediately above and below energy gaps in the excited states of the neutral species. To our knowledge laser action has not been observed before in the neutral spectra of Mg, Zn and In. Note that to produce laser oscillation in materials other than cadmium using the arrangement shown in FIG. 1, one merely replaces the cadmium strips with strips of other materials and provides the laser resonator with mirrors having high reflectivity at the appropriate wavelengths.
The 1.433 μm output from a SPER laser in cadmium produced by discharging a 0.01 μF capacitor initially charged to 18 kV in the presence of helium gas at 3 Torr pressure is shown in FIG. 2. When the rear resonator mirror 150 was removed, no radiation at or near 1.433 μm due to either spontaneous emission or stimulated emission could be detected. The onset of the 48 μsec duration laser pulse occurred long, ˜40 μsec, after the 2 μsec current pulse was over. Delay times as short as 5 μsec and as long as 100 μsec have been observed under some conditions. This delay correlated well with the observation of visible spontaneous emission from highly excited levels in neutral cadmium. This delayed spontaneous emission is a characteristic feature of the plasma-recombination process as detailed in an article by applicants entitled, "Recombination Lasers in Expanding CO 2 Laser-Produced Plasmas of Argon, Krypton and Xenon", by W. T. Silfvast, L. H. Szeto and O. R. Wood II, Applied Physics Letters, Vol. 31, No. 5, Sept. 1, 1977, pp. 334-337.
The peak power of the pulse shown in FIG. 2 was not high because the active length of the device was so short. A brief attempt to measure the energy in this pulse yielded an upper limit of 50μ Joules. Hence, given a 48 μsec pulse width, the peak power must have been no more than 1 Watt. However, since the number of atoms produced per pulse was so small, discussed hereinbelow, even if every cadmium atom were initially in the upper laser level and if the resonator could extract all of the stored energy, less than 10μ Joules would be expected. Therefore, at this time, the relative output power reported in the last column of Table I can only be given in terms of detector output voltage.
The dependence of laser output on helium pressure was found to vary according to the number and size of the gaps between the metal strips. For example, in a segmented plasma recombination laser in cadmium with 1 mm gaps, the optimum helium pressure, keeping the charging voltage constant, for 1 gap was 3 Torr, for 6 gaps was 7 Torr and for 12 gaps was 12 Torr. In this same device, even though the optimum position for the optic axis 160 of the laser resonator in this embodiment was 7 mm above the row of strips, laser oscillation could be observed anywhere in the 3 mm to 10 mm range.
A preliminary life test was conducted on a segmented plasma cadmium laser. The device to be tested was constructed of 1 mm thick by 2 mm wide by 10 mm long strips of cadmium in such a way as to have six 0.5 mm wide gaps. The apparatus was run at full power (0.01 μF capacitor charged to 21 kV) for 100,000 pulses at 2 pulses/sec with no discernable decrease in output power although the 7 Torr fill of helium gas had to be replaced occasionally.
After 100,000 pulses the device described above was dismantled and the cadmium strips were weighed. It was found that 2.1 mg per gap of cadmium had been lost during the test. This corresponds to a loss of approximately 10 14 atoms per gap per pulse. This implies that the initial cadmium density in the gaps is a maximum of 10 17 cm -3 . At the time of onset of laser oscillation, after the volume expansion has taken place, the cadmium density has dropped to less than 10 14 cm -3 . This, when taken together with the observation of a large delay time between the current pulse and the onset of laser oscillation and the observation of laser action only on transitions that occur across energy gaps in the excited states of the neutral, makes a strong case for a population inversion mechanism based on the following plasma-recombination process: A large fraction of the cadmium atoms produced in the gaps are thought to appear initially as ions. During the volume expansion (from 1 mm 3 to 10 3 mm 3 ) plasma electrons are cooled via collisions with helium gas and as a consequence the electron-ion recombination rate is significantly increased. Because of the high electron densities present, as the cadmium ions recombine with free plasma electrons, they move downward through the high-lying neutral levels by electron collisions with other free electrons until a sufficiently large energy gap is reached. Population builds up at this bottleneck and an inversion is created with respect to lower lying levels. The resulting laser has the potential for high efficiency since all of the excitation is concentrated at the upper laser level.
Extension of this same concept to produce laser action in other elements is possible, as is the scaling in active length and volume. For example, by placing a second segmented plasma device parallel to but 12 mm above the first (positioned so that the plasma expand toward one another) the power output of a segmented plasma cadmium laser at 1.433 μm was increased by more than a factor of 5. Or, by placing one 5.5 mm high glass plate on each side of a row of cadmium strips to provide some plasma confinement, the power output from a segmented plasma cadmium laser at 1.433 μm was increased by a factor of 4. In addition, it was found that increasing the number of gaps in a Cd SPER laser from 6 to 46, while keeping the input energy constant, significantly increased its gain and power output.
TABLE I______________________________________ POWERELE- WAVELENGTH TRANSI- ASSIGN- OUTPUTMENT (μm) TION MENT (mV)______________________________________Ag 1.840 4f .sup.2 F.sub.5/2.sup.o -5d .sup.2 D.sub.5/2 0.4C 0.941 3p .sup.1 D.sub.2 -3s .sup.1 P.sub.1.sup.o 10 1.454 3p .sup.1 P.sub.1 -3s .sup.1 P.sub.1.sup.o 15Cd 1.398 6p .sup.3 P.sub.2.sup.o -6s .sup.3 S.sub.1 1.433 6p .sup.3 P.sub.1.sup.o -6s .sup.3 S.sub.1 55 1.448 6p .sup.3 P.sub.o.sup.o -6s .sup.3 S.sub.1 1.640 4f .sup.3 F.sup.o -5d .sup.3 D.sub.1 18In 1.343 6p .sup.2 P.sub.1/2.sup.o -6s .sup.2 S.sub.1/2 1.5 1.432 6d .sup.2 D.sub.5/2 -6p .sup.2 P.sub.3/2.sup.o 15 1.442 6d .sup.2 D.sub.3/2 -6p .sup.2 P.sub.1/2.sup.o 15Mg 1.500 4p .sup.3 P.sub.2.sup.o -4s .sup.3 S.sub.1 15Pb 1.308 7d .sup.3 F.sub. 3.sup.o -7p .sup.3 D.sub.2 14 or 7p .sup.3 P.sub.1 -7s .sup.3 P.sub.1.sup.o 1.532 5f .sup.3 F.sub.2 -6d .sup.3 F.sub.3.sup.o 4 or 8s .sup.1 P.sub.1.sup.o -7p .sup.3 P.sub.1Sn 1.357 6p .sup.1 P.sub.1 -6s .sup.1 P.sub.1 10Zn 1.308 5p .sup.3 P.sub.2.sup.o -5s .sup.3 S.sub.1 2.5 1.318 5p .sup.3 P.sub.1.sup.o -5s .sup.3 S.sub.1 5______________________________________ | A high-voltage, high current pulse is applied to a series of two or more conducting strips (101-110) installed in series in a laser cavity (150-151) containing either a buffer gas or a vacuum. The strips are separated by small gaps. When the high-voltage, high-current pulse is applied to the strips, plasmas (141-149) are formed in the gap regions. The plasmas are comprised of ions from the strip material. Once formed, these plasmas expand hemispherically, cool and recombine to provide laser action. The composition of the plasmas depends on the strip material, the electric field in the gaps, the gap size and the background gas type and pressure. | 7 |
BACKGROUND OF THE INVENTION
The invention relates to a fluid control system for the security orientated control of at least one fluid power actuator or actor, comprising at least one local control means for the control of the fluid power actuator by way of control instrumentality means of the fluid control system, at least one sensor being provided for the transfer of at least one information item in relation to at least one operational state of the fluid power system to the local control means.
Furthermore, the invention relates to a fluid control actuator, a local control means for a fluid control system, a software module for a local control means of a fluid system and to a method for the operation of a fluid control system.
One system, of the type to which the invention relates, and termed a “fluid control” system may for example be operated as a pneumatic system with the aid of compressed air or as a hydraulic system with the aid of hydraulic oil as a pressure medium or “fluid”. In this case an electrical control means controls, by way of control instrumentality means, as for example valves, the flow of the pressure medium for the operation of the fluid control actuator or actuators. Such an actuator is for example a fluid power cylinder. The respective operational state of the fluid control system is in this case monitored with the aid of a sensor. It may for example be attached to the fluid control actuator of a position sensing system, which provides the control means with information as regards the respective position of the actuator so that same may, on the basis of the information, influence the position of the actuator by suitably acting on it with the pressure medium.
In the case of known fluid control a basic assumption is that by suitable design of the fluid control system it is possible to prevent a security risk occurring within the respective fluid control system. Protection against accidental changes in the condition of, or position in, the fluid control system, as for instance a sudden movement of a piston in a fluid power cylinder owing to a defect of a valve controlling the fluid power cylinder, is however not provided for.
SUMMARY OF THE INVENTION
One object of the invention is to provide security functions for fluid control systems.
This object is to be attained by a fluid control system for the security relevant control of at least one fluid control actuator, having at least one local control means for the control of the fluid control actuator by way of control instrumentality means of the fluid control system, there being at least one sensor for the provision of at least one item of information as regards at least one operational state of the fluid control system to the local control means, characterized in that the local control means is so designed that it can evaluate at least one item of information for detecting at least one security relevant state and that, given at least one security relevant state, it implements at least one predetermined consequential action.
The object is furthermore to be attained by a fluid control actuator in accordance with the technical teaching of claim 16 , by a control means in accordance with the technical teaching of claim 17 , by a software module in accordance with the technical teaching of claim 18 and by a method in accordance with the technical teaching of claim 19 .
In this respect the invention is based on the notion of integrating security relevant functions in the fluid control system for the control of the actuator, such functions fulfilling simple and also advanced requirement classes, for instance in accordance with the European standard EN 941-1. The fluid control actuator can for instance be a valve arrangement, a pneumatic drive or a servicing unit. The control instrumentality means may for example comprise a valve arrangement, and be operated by an electronic control module as a local control means. If within the control instrumentality means, the local control means or the controlled fluid control actuator a security relevant, improper function occurs, the local control means will recognize this problem and will initiate consequential action to deal with it.
The local control means ensures that a security relevant state does not pass unrecognized. The monitoring of the security function can then be attuned to the respective fluid control system in a optimum fashion and more particularly to the actuator, which is to be controlled. Sensor instrumentalities, which are in any case present, may then be employed for the security functions as well. It is however also possible that with the aid of some additional sensors even higher security criteria may be attained. Moreover, the fluid control system may be utilized as a complete, compact and prefabricated unit, already having integrated security functions, which for instance may cooperate with a higher order control means. They then do not have to be matched to the locally required security functions in an elaborate manner. The local control means may also transmit and receive messages specially adapted for;the transfer of security relevant information and for the issue of security relevant commands.
The fluid control system in accordance with the invention, which is security orientated, may also be designed as part of a fluid control actuator or actor. Thus for instance the fluid control system may be integrated in a locally controlled valve arrangement, which may be a single valve or a valve group, that is to say a so-called valve island. Furthermore, the security orientated system in accordance with the invention may be a component of a fluid drive, as for example of a pneumatic gripper, a pneumatic cylinder or a pneumatic linear drive. A switch-on valve, a servicing device, as for instance an oiler or a “pneumatic emergency off means” may be controlled by an external or integrated fluid control system in a security orientated manner. Thus in accordance with the invention shut off valves integrated in a pneumatic cylinder may be controlled.
As an example the control means may in accordance with the invention check an information item, as supplied by a sensor for monitoring the movement speed of an actuator, as to whether a predetermined speed of movement of the actuator is being exceeded. In such a case the sensor may even be employed for a plurality of functions, on the one hand for the control of the speed of movement as regards a predetermined value and on the other hand for checking to see whether the actuator has exceeded a security relevant speed of movement.
Further advantageous developments of the invention are defined in the dependent claims.
Once the local control means has detected the existence of a security relevant state, it may for instance cause the fluid control actuator to assume a secure state of operation as a consequential action, such state being for example a so-called “emergency stop” function, in the case of which the actuator is halted.
Moreover, the local control means may, for example by way of an LED or a loudspeaker, signalize the presence of the security relevant state and thus facilitate the location of a fault by the operator. Furthermore the local control means may transmit a message concerning the presence of the security relevant state to a higher order control means, if the local control means acts for example as a slave on a bus and is controlled and monitored by the higher order control means functioning as a master. In this case it is also possible for the higher order control means to give an instruction to the local control means for bringing the fluid control actuator into a safe operational state, that is to say for instance the above mentioned “emergency halt” function.
In a particularly preferred form of the invention the fluid control system comprises fluid power and/or electrically operated switching off means, which are able to be controlled by the local control means for switching off the effective function of the control instrumentality means as regards the fluid control actuator. The switching off means are for instance check valves placed between the control instrumentality means and the actuator. This means that it is possible for the control instrumentality means to be switched off and therefore decoupled from the actuator, when a fault occurs in the control instrumentality means. Thus for example a valve may leak so that the actuator will assume an irregular, undesired position. The local control means can find such a fault for example using control checking means cooperating with same, as for example pressure sensors, for checking the control instrumentality means.
Moreover, using the switching off means it is possible to cause the local control means firstly to at least partly switch off the effective function of the control instrumentality means by means of the switching off means and then to perform a check of the control instrumentality means. In this case the control instrumentality means may be operated without any undesired influence on the actuator and for example to run through a check cycle. Such a check cycle is for example performed in each case prior to operation of the control instrumentality means so that same are only employed for operation of the actuator, when they function correctly. The control instrumentality means may also be checked cyclically so that any malfunction of the control instrumentality means will be detected, if same as such have been idle for a long period of time.
In accordance with a further possible form of the invention the switching off means are also checked using for example sensors arranged on the switching off means, which detect changes in the state of the switching off means and signalize such information to the local control means. The local control means will then determine whether the signalized changes in state are in accordance with predetermined, expected changes in state or whether a malfunction, which may possibly be security relevant, of the switching off means is involved. The local control means can then signalize this malfunction to, for example, the higher order control means or cause an “emergency halt” function to take place. The control means may also perform the check on the switching off means cyclically or in each case after operation of the control instrumentality means or of the switching off means.
The fluid control system can also be instructed by the higher order control means by way of check instruction to check both the switching off means cyclically or in each case for each received check instruction.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be described in the following with reference to working embodiments as illustrated in the accompanying drawings.
FIG. 1 shows a first embodiment of the invention with a fluid control system, which is controlled by a local control means and acts on a fluid power cylinder.
FIG. 2 is a table of the performance of a check on the working example of FIG. 1 with the fluid power cylinder in a first position.
FIG. 3 is a table as in FIG. 2 with a further check run but with the fluid power cylinder in the second state.
FIG. 4 shows a second working example of the invention with less or modified components than in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a fluid power cylinder 10 as a fluid actuator comprising a piston 11 and a piston rod 12 which are able to reciprocate in a working space 13 . A fluid as a pressure medium, in the present case compressed air, is able to flow through a cylinder end plate and a line 14 therein at the end of the working space 13 into such space. Accordingly the piston 11 assumes its first (retracted) position the piston rod 12 consequently moves into the working space 13 , when at the opposite end facing the face of the piston 11 and at the end plate of the working space 13 by way of a line 15 air displaced by the moving piston is able to escape and the working space 13 is vented. When however by way of the line 15 compressed air flows into the working space 13 , the piston 11 moves into the second position the piston rod 12 therefore moves out of the working space 13 providing air can flow out through the line 14 . A sensor 16 detects whether the piston 11 has moved out. A sensor 17 detects whether the piston 11 has moved in. Instead of the,fluid power cylinder 10 the actuator may be in the form of a linear drive, a servicing unit for the preparation of compressed air or a pneumatically operated valve as a fluid control actuator.
The line 14 can be switched off by means of a routing valve 21 , compressed air then hot being able to flow into the working space 13 and air displaced by the piston 11 is not able to leave the working space 13 . The routing valves 20 and 21 accordingly act as switching off means and are so-called 2/2 way valves. A 2/2 way valve has an input and an output, which are separated from each other by the closed position of the respective routing valve or are connected together in an open position of the respective routing valve. The output of the routing valve 20 is connected with the line 14 and the output of the routing valve 21 is connected with the line 15 . The routing valves 20 and 21 are able to be acted upon by way of a line 22 by compressed air and then move into the open position. In the switching state of FIG. 1, the switched off position namely, the routing valves 21 and 22 are however not acted upon by compressed air and are held by a spring in the switched off position. At this point it is to be noted that the design of the components illustrated in FIG. 1 is merely symbolic. The routing valves 20 and 121 can for instance also be driven electrically be held by compressed air in the neutral position or be replaced by other valve arrangements with a switching off function.
The line 22 receives compressed air by way of a routing valve 23 or is vented through it. The routing valve 23 is a 3/2 way valve having a power output for the line 22 , an input, which is connected with a pressure source 24 , and a venting output 25 . The routing valve 23 is held in FIG. 1 in the venting position as its neutral position, as indicated by a spring means, in the case of which the line 22 is vented through the venting opening 25 . By means of an electrical drive 26 , for instance a solenoid drive, it is possible for the routing valve 23 to be moved into a switching position, compressed air then flowing from the pressure source 24 into the line 22 and the routing valves 20 and 21 being moved into the switched on position. The line 22 is furthermore connected with a pressure sensor 27 , responsive to the pressure in the line 22 . The pressure sensor 27 serves as a switching off check means for checking the routing valves 20 , 21 and 22 acting as switching off means. Instead of the pressure sensor 27 as switching off and checking means, sensors could for instance be utilized responsive to the position and arranged on the routing valves 20 , 21 and 22 .
As control instrumentality means for the control of the fluid power cylinder 10 a routing valve 30 is employed, which in the present case is a 5/3 way valve having three positions, a neutral position 31 , a second (piston extended) position 32 , a first (piston retracted) position 33 and in all five inputs and outputs, of which one input is connected with a pressure source 34 for supply with compressed air, one respective output 35 and 36 serves for venting and one input/output is connected by way of line 37 with the routing valve 20 and one input/output is connected by way of a line 38 with the routing valve 21 .
In the following description of the function of the routing valve 30 the routing valves 20 and 22 will be assumed to be in the on position. The lines 14 and 37 and also the lines 15 and 38 are respectively connected with one another. In the illustrated neutral position 31 , which is for example set by springs arranged on the solenoid valve 30 , all five inputs and outputs of the routing valve 30 are separated from one another so that no controlling pressure forces or venting forces act on the fluid power cylinder 10 and same will essentially maintain its respective position. When a drive 39 , which is arranged on the routing valve 30 , is activated, the routing valve 30 will be moved into the second position 32 , in which the compressed air flows into the lines 38 and 15 and compressed air may leave by way of the lines 14 and 37 and furthermore the output 35 . The piston rod 12 then moves out of the fluid power cylinder 10 . If a drive 40 , which is also arranged on the routing valve 30 , is activated, the routing valve 30 will be moved into the first position 33 so that compressed air will on the one hand flow into the lines 14 and 37 and on the other hand may leave by way of the lines 38 and 15 . The piston rod 12 then moves into the fluid power cylinder 10 . Instead of the routing valve 30 other valve arrangements are possible. Thus for example instead of the routing valve 30 respectively a 3/3 way valve could arranged on the lines 37 and 38 , using which valves pressurization and, respectively, venting and furthermore shut down of the lines 37 and 38 will be possible.
For checking the respective pressure conditions a pressure sensor 41 is provided on the line 37 and a further pressure sensor 42 is provided on the line 38 . The pressure sensors 41 and 42 act as control checking means. Furthermore as a check and control means a sensor system could be provided, as for example in the form of end switches for monitoring the function of the routing valve 30 , on which it will be arranged.
The routing valves 20 , 21 and 23 , which are connected together by the line 22 and are supplied from the pressure source, are switching off means for switching off the active function of the routing valve 30 acting as a control means.
The functions of the routing valves 23 and 30 are controlled by way of the respective drives 26 and furthermore 39 and 40 by the a local control means 50 . The local control means 50 possesses an input/output module 51 , a processor 52 , memory means 53 and interface modules 54 and 55 as connection means, which are respectively connected by connections, not illustrated, with each other. The local control means is operated by an operating system and furthermore by software modules, which are stored in the memory means 53 and whose program code sequences are implemented by the processor 52 . The memory means 52 comprise for instance RAM modules for data to be temporarily stored and flash memory modules and/or ROM modules for long term data storage.
By way of the interface module 54 connected with a bus 56 the local control means 50 is connected with a higher order control means 57 , from which the control means 59 can receive setting commands and to which the control means 50 can signalize information. The bus 56 may be a field bus, as for example an AS-i bus (actor sensor interface), a CAN bus or a Profibus. The higher order control means 57 is in the present example a bus master, whereas the local control means 50 is a bus slave. It is also possible for the local control means 50 to be employed without the higher order control means 57 or for further valves or drives to be connected with the control means 50 . The higher order control means 57 may furthermore be omitted completely.
Further still, the local control means 50 can be connected the high order control means 57 by way of digital inputs and outputs.
Furthermore the interface module 55 is connected by way of connection lines 58 with a display and command input module 59 . From the display and command input module 59 the control means 50 can receive commands, for instance by way of electrical hand switches or keys. Moreover, the control means 50 may signalize information to the module 59 , which the module can display, for example using LEDs. It is furthermore possible for the module 59 to be integrated in the control means 50 or to be dispensed with completely.
The input/output module 521 is connected by way of a connection 61 with the drive 39 , by way of a connection 62 with the drive 40 and furthermore by way of a connection 63 with the drive 26 . By way of the connections 61 , 62 and 63 it is possible for the control means 50 to activate respectively connected drives. Moreover the pressure sensor 41 the pressure sensor 42 by way of a connection 64 , the pressure sensor 27 by way of a connection 66 by way of a connection 65 , and the pressure sensor 27 by way of a connection 66 , signalize the respectively detected pressure values to the input/output module 51 and accordingly to the control means 50 too. Furthermore the sensor 16 sends its readings for the respective fluid power cylinder 10 by way of a connection 67 to the control means 50 and the sensor 17 sends its respective readings related to the fluid power cylinder 10 to the control means 50 . The (monitoring) connections 64 , 65 , 66 67 and 68 and furthermore the (control) connections 61 , 62 and 63 may be discrete lines or furthermore by way of a bus.
In the following a check cycle by way of example will be described with reference to FIGS. 2 and 3 for examining the correct function of the arrangement of FIG. 1 . The FIGS. 2 and 3 respectively show a table, in whose left hand column headed “ST” the checking and working steps are entered.
The columns headed “31”, “32” and “33” contain the neutral position 31 , the second position 32 and the first position 33 of the routing valve 30 for the operation of the fluid power cylinder at 10 . In this respect “0” in the columns “31”, “32” and “33” indicates that the routing valve 30 has not assumed the respective position. Furthermore “0→1” in the column “32” means that the drive 39 is activated and the routing valve 30 has the second position 32 and has reached it at “1”. In the column “33” “0→1” means that the drive 40 is activated and the routing valve 30 has assumed the first position 33 and has reached it a “1”. In the column “31” the values entered indicate whether the routing valve 30 has assumed the neutral position 31 —owing to spring force and the non-activation of the drives 39 or 40 —(“0→1”) (“1), is leaving it (“1→0”) or has already left it (“0”).
The columns “20”, “21” and “23” are to be read in a manner similar to the columns “32” and “33”. In the column “23” “0” means that the drive 26 is not activated by the control means 50 and hence the routing valve 23 is in the venting position (=neutral position). The routing valves 20 and 21 , whose control by the compressed air on the line 22 is indicated in the columns “20” and “21”, are here in the neutral position, that is to say in the turned off position (“0”). If the drive 26 is activated by the control means 50 (“0→1”) the routing valve 23 will pass into the switching position (“1”).
This means that the routing valves 20 and 21 are also operated and move over into the on position.
The columns “27”, “41” and “42” indicate the signals sent by the pressure sensors 27 , 41 and 42 to the control means 50 , “0” meaning “no pressure present” and “1” meaning control pressure applied”. In the case of digitally operating pressure sensors here an “X” stands for an irregular or non-defined intermediate value of the acting pressure. The digital or binary manner of signalizing (“0” or “1”) is however only by way of example, for the pressure sensors 27 , 41 and 42 can, given a suitable design thereof, also signalize exact intermediate or analog values for the respective acting pressure thereat.
The columns “16” and “17” indicate the messages from the sensor 16 and 17 . In this case “0” means that the piston 11 is clear of the respective sensor and the respective sensor is sending a digital signal “0” to the control means 50 , whereas the piston 11 at “1” is at a minimum distance from the respective sensor.
FIG. 2 shows a check cycle starting with a step 200 with the piston 11 fully in the first position. The sensor 17 then provides the signal “1” and the sensor 16 provides the signal “0”. Furthermore the routing valve 23 and, independently thereof, the routing valves 20 and 21 are activated and the pressure sensor 27 produces the signal “1” so that by way of the routing valve 30 in the active (=“1”) first position 33 compressed air may flow by way of the lines 37 and 14 into the fluid power cylinder 10 . The pressure sensor 41 consequently produces the signal “1”, whereas the pressure sensor, which is now connected with the vented line 38 , produces the signal “0”.
In a step 201 firstly the fluid power cylinder 10 is cut off from the lines 37 and 38 leading to the routing valve 30 and accordingly is cut off from an undesired action of pressure and venting. The control means 50 in this case drives the routing valve 23 to assume the venting position so that the line 22 is vented, the pressure sensor 27 signalizes a pressure dropping to “0” (“0→1”) and the routing valves 20 and 21 go into the shut off position (“0→1”). In the transition phase until the routing valve 23 assumes its venting position the pressure sensors 41 and 42 provide a non-defined signal “X”.
In a step 202 the routing valves 20 and 21 and moreover the pressure sensors 41 and 42 are then checked. Since the routing valves 20 and 21 are in the closed position the routing valve 30 may be operated without any effect on the fluid power cylinder 10 . For this purpose the control means 50 activates the drive 39 and deactivates the drive 40 so that the routing valve switches over from the first position 33 into the second position 32 ; the pressure sensor 42 sends a signal changing from “0” to “1” owing to the compressed air flowing into the line 38 and the pressure sensor 41 sends a signal changing from “1” to “0” owing to venting of the line 37 . If this is not the case there is an error, which is recognized by the control means 50 and for example will be signalized to the higher order control means 57 .
In a step 203 the routing valve 30 is shifted into the neutral position 31 , because the control means 50 also deactivates the drive 39 as well. The lines 37 and 38 and therefore the chambers of the fluid power cylinder 10 are then cut off both by the routing valves 20 and 21 and also by the routing valve 30 from a pressure action or a venting action.
Accordingly even without any further action on the fluid power cylinder 10 the routing valve 23 and, independently from it, the routing valves 20 and 21 may be activated in a step 204 . The respective setting signals of the routing valves 20 and 21 change, like the value detected by the pressure sensor 27 , from “0” to “1”. Should this not be the case, this will mean an error in the switching off means, which is recognized by the control means 50 . It is also possible to arrange sensors in the routing valves 23 , 20 and 21 , such sensors being connected respectively with the control means 50 whose signals are checked by the control means 50 in the step 203 . When then an error occurs, the control means 50 can conclude that there is a security relevant situation or risk and take a counter measure, as for instance it can prevent further actuation of the routing valve 30 . If in the step 204 the routing valve 20 shifts into the open position, any compressed air still present in the fluid power cylinder 10 at the end plate end and in the line 14 can flow into the line 37 so that the pressure sensor 41 signalizes values changing from “0” to “1”, which are monitored by the control means 50 and if such values are not present the control means 50 will detect a security relevant state.
When the step 204 has been performed without any fault, the control means 50 will, in a step 205 , drive the routing valve 30 back into the first position 33 , this being done by activation of the drive 40 , that is to say by sending a setting signal changing from “0” to “1”. This means that the line 15 is vented by way of the line 38 and the venting output 36 and in the case of error-free operation the pressure sensor 42 will signalize values changing from “1” to “0”.
The check cycle with the fluid power cylinder 10 in the first position is now terminated. Such a check cycle may be repeated at any time, even when there is no movement of the fluid power cylinder 10 , for instance at fixed times and for example after the fluid power cylinder 10 shifts into the first (retracted) position or before the fluid power cylinder 10 shifts into the second position. Such a movement into the second position is represented in a step 206 . In this case the control means 50 activates the drive 39 by the transmission of a setting signal changing from “0” to “1”. Simultaneously the control means 50 deactivates the drive 40 so that the line 14 is vented by way of the line 37 and the venting output 35 and the pressure sensor 41 signalizes, in the case of a fault-free operation, a value changing from “1” to “0”, while the lines 38 and 15 receive compressed air, the pressure sensor 42 signalizes values changing from “0” to “1” and the piston 11 in the fluid power cylinder 10 is shifted into the first position. When the piston 11 reaches the end plate end the sensor 16 will produce a “1” signal and the sensor 17 a “0” signal.
The end of the movement into the second position is then at the same time the starting position illustrated in FIG. 3, denoting a step 300 . In the second position as well a check cycle may be performed, as will be described in the following.
In a step 301 with an effect equivalent to that of the step 201 firstly the fluid power cylinder 10 is cut off from the lines 37 and 38 leading to the routing valve 30 and accordingly from any undesired action of pressure and undesired venting.
In a step 302 corresponding to the step 202 the routing valves 20 and 21 and furthermore the pressure sensors 41 42 are checked. The routing valves 20 and 21 are in the off position and the routing valve 30 can consequently be switched over from the second position 32 into the first position 33 by the control means 50 without affecting the fluid power cylinder 10 . For this purpose the control means 50 activates the drive 40 and deactivates the drive 39 so that owing to the compressed air flowing into the line 37 the pressure sensor 41 provides a signal changing from “1” to “0” and the pressure sensor 42 , owing to venting of the line 38 , provides a signal changing from “1” to “0”. Should this not be the case, there is a security relevant fault, which is recognized by the control means 50 and same will, for example, activate a warning LED in the display and command input module 59 .
In a step 303 the control means 50 will also deactivate the drive 40 so that the routing valve 30 will go into the neutral position and can be neither vented nor supplied with compressed air externally. Then in a step 204 the routing valve 23 , and independently thereof, the routing valves 20 and 21 may be activated again and moved into the open position so that compressed air still present in the fluid power cylinder 10 at the end plate end and in the line 15 may flow into the line 38 and the pressure sensor 42 will signalize values changing from “0” to “1”. Such values are monitored by the control means 50 as values to be expected so that the control means 50 will signalize a security relevant error if there is a trouble condition.
In a step 305 the control means 50 activates the drive 39 again the so that the routing valve 30 returns to the second position and compressed air present in the lines may escape. The pressure sensor 41 then signalizes values changing from “1” to “0”. This check cycle, which is now terminated, can also be repeated at any time.
A step 306 shows how the piston 11 may return to the first position. Here the drive 39 is deactivated and the drive 40 is activated. The pressure sensor 42 signalizes falling pressure values owing to venting and owing to the action of compressed air the pressure sensor 41 signalizes increasing pressure values. After the piston 11 has reached the end plate, the sensor 17 generates the “1” signal and the sensor 41 generates the signal “0”.
The control means 50 can implement the check steps represented in FIG. 2 and FIG. 3 in accordance with predetermined criteria, for example criteria set by configuration data. It is also possible for the control means 50 to be provided with a command for the performance of the check steps at the display and command module 59 or by the higher order control means 57 . Moreover, the control means 50 may receive from this source a security relevant command, in which the control means 50 is instructed to terminate a security relevant situation, for example, by its putting the routing valves 20 and 21 in the turned off state.
FIG. 4 essentially shows the arrangement of FIG. 1, identical or functionally equivalent components having the same reference numerals. However, the components utilized as switching off means, and more especially the routing valves 20 , 21 and 23 and lines and furthermore the pressure sensor 27 employed as switching off check means, are omitted. Furthermore the sensor 17 is omitted, whereas the sensor 16 is in this case designed in the form of a distance apart sensor, which measures the distance of the piston 11 from the end plate of the fluid power cylinder 10 . Moreover, a pressure sensor 70 is shown, which is responsive to the compressed air pressure supplied by the pressure source 34 and passing by way of the line 69 to the routing valve 30 , it signalizing such pressure by way of a connection 71 to the control means 50 . The control means 50 can set the pressure supplied by way of the pressure source 34 to the line 69 using a choke valve 72 , which is connected by way of a control connection 73 with the input/output module 51 . The choke valve 72 is accordingly a part of the control means.
By control of the routing valve 30 the control means 50 sets, as already explained, the direction of motion of the piston 11 , and using the choke valve 72 it sets its holding forces and its speed of movement. The speed of movement can be found by the control means 50 on the basis of the distance, which is found by the sensor 16 , and changes with a movement of the piston 11 , of the piston 11 from the end plate.
If the speed of movement of the piston 11 is too great, the control means 50 , acting by way of choke valve 72 , will reduce the pressure on the line 69 and if the, speed of movement is too low, it will increase the pressure. However it is possible for a defect to occur in the choke valve so that for example compressed air would act without reduction in its high pressure on the piston 11 and a piston crash might result from the high speed of motion. The control means 50 will however recognize such a security relevant situation with the aid of the sensor 16 and therefore in an “emergency off function” will move the routing valve 30 into the neutral position 31 so that working space 13 is cut off from the pressure source 34 and at the same time venting is prevented and therefore the piston 11 is braked.
Even if a security relevant fault occurs at the routing valve 30 the control means 50 can recognize same and cause consequential action to be taken as a remedy. If namely the routing valve 30 is for example in the second position 32 equal pressure values must be detected by the pressure sensor 42 and the pressure sensor 70 , which are substantially higher than the values detected by the pressure sensor 41 as a consequence of the venting of the line 14 . If this is not the case, the control means 50 will recognize this problem and will signalize the problem in a security relevant communication to the higher order control means 57 . The latter will then for example instruct the control means 50 to completely close the choke value 72 in a security relevant emergency command.
It is also possible for the control means 50 to drive a lower order control means, not illustrated, in the manner indicated and in a security relevant fashion and for example to lock the fluid power cylinder 10 in an “emergency off function” in response to a warning signal provided by same. | A fluid control system for security relevant control and a fluid control actuator, a local control means for a fluid control system, a software module for a local control means of a fluid control system and a method for the operation of a fluid control system. The fluid control actuator ( 10 ) is controlled by control instrumentality means ( 30 ) of a local control means ( 50 ). A sensor ( 16, 17, 27, 41 and 42 ) transfers information concerning operational states of the fluid control system to the local control means ( 50 ). For this purpose there is a provision such that the local control means ( 50 ) determines from such information whether there is a security relevant situation and if necessary performs a predetermined function. The security relevant functions are integrated in the fluid control system so that same is able to be employed as prefabricated unit. | 5 |
The present application is a Bypass Continuation of International Application No. PCT/EP2011/005155, filed on Oct. 14, 2011, which claims priority from German Patent Application 10 2010 060 401.1, filed on Nov. 8, 2010. The contents of these applications are hereby incorporated into the present application by reference in their respective entireties.
FIELD AND BACKGROUND OF THE INVENTION
The invention relates to a welding device that is configured for sealing welding of thermoplastic hoses and that comprises a pinching device with at least two pinching jaws, of which at least one is movable and between which a hose, which is to be welded, can be pinched, wherein the pinching device has a heating device, which is coupled to a control unit and is configured to heat the hose pinched between the pinching jaws.
Furthermore, the invention relates to an automated metering device for the metered transfer of a medium from a supply container via a connecting hose, which is made of a thermoplastic material, into a target container, wherein the connecting hose can be positioned between at least two pinching jaws of a controllable pinch valve, which is coupled to a control unit, so that a volumetric flow rate of the medium can be controlled by controlling a pinching pressure that is exerted on the connecting hose by the pinch valve at a pinching point.
Finally the invention relates to the use of the aforementioned welding device in conjunction with the aforementioned metering device.
A welding device of the type described is known from the EP 0551813 B1. A metering device as described above is known from the EP 1525138 B1.
There is a strong trend in modern medical and biotech industries away from re-usable containers to single use containers, so-called “disposables.” As a rule, all manufacturing, dispensing, storage and application processes of medical and/or biotechnology fluids have to be carried out under aseptic conditions. In the event that re-usable containers are used, this requirement is fulfilled by first sterilizing the fluids and then checking and documenting the achieved sterility. The processes associated with this sequence of steps are technically intricate and cost intensive. They can be largely dispensed with if single use containers, i.e. disposables, which are already delivered in an aseptic condition by the manufacturer, are used. Plastic bags in particular have achieved success on the market as single use containers. They can be manufactured at a low cost, are easy to sterilize, are light in weight and have very little volume in the empty state, making them easy to dispose.
For typical processes both during the manufacture and also the use of medical and/or biotechnology fluids, the metering operations play an important role. These metering operations take place under various circumstances, e.g. during administration of the fluid, during mixing of various fluids or during dispensing of a fluid into commercially available containers. In any case at least one fluid has to be transferred from at least one supply container into at least one target container. Flexible plastic hoses are widely accepted for the purpose of connecting the supply container and target container, each of which is made as a plastic bag. Under hygienic aspects the coupling of the hose to a container is viewed critically, for which reason the manufacturers usually provide the bags as a single part or by material bonding with the hoses or with whole hose systems. Once the bag is filled, these hoses are permanently closed, typically at their ends, by welding. Closing the hoses by welding has many advantages. First of all, a bag, or more specifically a hose that is closed by welding, is tamper proof. Secondly, the end of the hose is heated by the welding operation, so that an additional sterilization process is carried out at the critical opening point. In principle, the welding operation is possible with any thermoplastic material, such as PVC, PE, PET, PU, etc.
The aforementioned EP 0 551 813 B1 discloses a welding device, in which the hose that is to be welded is pinched between two pinching jaws that are constructed as welding electrodes. The pinching pressure that is constant during the entire process is so high that it completely closes the free lumen of the hose at the pinching point. The pinching jaws together form a capacitor of an electric high frequency oscillating circuit. When the oscillating circuit is actuated at a suitably high frequency, the molecular dipoles of the hose material pinched between the pinching jaws are set into oscillation and, in so doing, heat up the walls of the hose. The heat buildup causes the hose to melt, so that under the constant pinching pressure the pinching jaws squeeze the softened hose material out of the pinching point, so that the initial result is the welding followed by a severing of the welding point. This publication document focuses, in particular, on the tuning of the resonance frequency of the electric oscillating circuit, where this resonance frequency changes through the passive approach of the pinching jaws under the constant pinching pressure owing to the resulting capacitance change of the capacitor.
The aforementioned EP 1 525 138 B1 discloses a metering device, with which a plurality of small bags provided as the target containers can be filled from a large bag functioning as the supply container. The metering, i.e. the control of the volumetric flow rate from the supply container to the target containers, is performed using pinch valves, which pinch the hose connections between the supply container and the target containers between the actively controllable pinching jaws. In so doing, the pinching pressure is varied in a controlled manner, so that the free lumen of the respective hose at the pinching point changes, and the volume flow through the hose at the pinching point can be varied, as required. Following completion of the bag filling operation, the access hose of the respective target bag is closed with a lock clamp and, in addition, can be permanently welded, for example, with the aforementioned welding device. A drawback of this approach is that the welding of the access hoses for the target containers has to be performed in a separate working step, a feature that entails not only higher costs due to the amount of time that is required and the need for an additional welding device but also entails hygienic risks.
OBJECTS AND SUMMARY OF THE INVENTION
An object of the present invention is to further develop a welding device of this type in such a way that a more efficient and hygienically safer welding of target containers, which are filled by way of hoses, can be performed in a more efficient and hygienically safer way.
An additional object of the present invention is to further develop a metering device of the type desired in such a way that the welding of the hoses of the filled target containers can be performed in a more efficient and hygienically safer way.
The first engineering object described above is achieved by supplementing conventional technology in such a manner that the at least one movable pinching jaw is actuable with a controllable, bidirectional actuator, which is coupled to the control unit in such a way that the pinching pressure acting on the hose is adjustable independently of the heating device.
The second engineering object described above is achieved by supplementing conventional technology in such a manner that at least one of the pinching jaws is provided with a heating device, which is coupled to the control unit and which is configured to heat the connecting hose. In other words, the second aforementioned engineering object is achieved through the use of an inventive welding device as a controllable pinch valve of a metering device.
One important feature of the invention is that the pinching pressure, which the pinching jaws of the welding device exert on the pinching point, is variable and is controllable, in particular, in a targeted way. The person skilled in the art will recognize that in this case there is no need to give an explicit pinching pressure specification. As a result, the pinching pressure can also be adjusted indirectly, for example, by an explicit specification of the distance between the pinching jaws or an actuator feed or the like. The prior art provides only the application of a constant pinching pressure, which can be achieved, in particular, with a passive element, such as, for example, a clamping compression spring. In contrast, the present invention provides that at least one of the pinching jaws be provided with a controllable actuator that is, for example, electrically, pneumatically, hydraulically or magnetically operable. Important is that the actuator can be controlled bidirectionally. That is, the actuator can be actuated not only to raise the pinching pressure but also to lower the pinching pressure. In this case the term “actuator” is to be construed in a broad sense and includes, in particular, also systems comprising a plurality of unidirectionally working, but antagonistically interacting setting elements.
Furthermore, it is important that the actuation of the actuator can take place independently of the heating device. If in the state of the art a change in the distance between the pinching jaws was solely due to the hose material melting at a constant pinching pressure, then the present invention provides that the pinching pressure can be adjusted, as required, in particular, indirectly by way of the distance between the pinching jaws, independently of the heating device and, in particular, when the heating device is inactive. This arrangement allows the free lumen of the pinched hose to be actuated between a maximum opening state and a completely closed state, so that a welding process is not absolutely necessary.
Just like the welding device known from the prior art, the welding device according to the invention has the ability to raise the temperature of the hose material up to at least its softening temperature. In this case the pinching pressure, which is high enough to completely close the lumen of the hose, can be actuated. In other words, the pinching device according to the invention, can be used, independently of one another, as a controllable pinch valve and can be used to permanently weld the hose at the pinching point.
Consequently an additional subject matter of the present invention is the corresponding application of the inventive welding device as a controllable pinch valve of an automated metering device, through which a medium can be transferred in a metered manner into a container from a supply container through a connecting hose, which is pinched between the pinching jaws of the welding device and is made of a thermoplastic material.
With respect to the metering device according to the invention, another important feature is the possibility of heating the pinched connecting hose using a heating device, which is assigned to at least one of the pinching jaws. In this case it has to be possible to raise the temperature up to at least the softening temperature of the connecting hose. In other words, the control valve, which is anyway present in metering devices of this type, is expanded to include the additional capability of permanently welding the pinched hose.
The present invention makes it possible to integrate the closing operation by welding into the metering operation, irrespective of whether in the course of dispensing, mixing or using or the like. In particular, the use of an additional device is not necessary. Even an additional working step, in particular, with the inclusion of manual process steps, is not necessary. The advantages with respect to cost savings and improvement in the hygienic safety are substantial.
The specific configuration of the heating device, with which the pinched hose can be heated, is of secondary importance to the present invention. For example, the hose can be heated directly by generating a high frequency electric field between the pinching jaws. In this case the frequency of the electric field is adjusted to a resonance frequency of the molecular dipoles of the hose material. As an alternative, the hose can be heated directly by heating the pinching jaws, which pinch the hose, using, for example, an integrated resistance heater. The pinching jaws can also be designed as friction welding heads or ultrasonic welding heads that generate microscopic relative movements in the pinched hose and, as a result, produce heat generating friction. Furthermore, use of a heat buildup through radiation, for example, infrared radiation or microwave radiation, is also possible.
Preferably the inventive arrangement provides that the control unit is configured
to control during a metering operation a volume flow of the medium through the connecting hose when the heating device is in the inactive state in that the pinching pressure, which is exerted on the connecting hose by the pinching jaws, is controlled, as required, and to activate the heating device following completion of the metering operation and to weld the connecting hose by application of a pinching pressure that closes the connecting hose.
With respect to the resulting metering device this means that the heating device is optimally suited and the control unit is optimally configured to heat, following completion of a metering operation, the connecting hose by application of a pinching pressure, which closes the connecting hose, to such an extent that the connecting hose is permanently closed by welding.
A preferred further development of the welding device according to the invention provides that at least one of the pinching jaws has a cutting device, which is coupled to the control unit and which is configured to sever the hose. With respect to the metering device according to the invention this means that preferably at least one of the pinching jaws has a cutting device, which is coupled to the control unit and which is configured to sever the connecting hose. For example, the cutting device can comprise a movable cutting blade.
Especially when the welding device according to the invention is used as described, the provision of a cutting device allows the connecting hose to be severed at the welding point following completion of the welding operation. For this purpose the control unit of the metering device according to the invention is configured preferably to actuate, upon completion of the welding operation, the cutting device for the purpose of severing the connecting hose. In other words, it is preferably provided that the pinched hose be severed at the welding point after said hose has been welded. This arrangement allows each individual bag that is filled to be reliably and permanently closed and then further processed separately, for example, sold. As an alternative to severing the hose using a cutting blade, the hose can also be melted by raising its temperature even more until the severance has taken place.
Additional features and advantages of the invention will be apparent from the following detailed description and the accompanying drawings, which illustrate by way of example some preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings show in
FIG. 1 : a metering device according to the invention.
FIG. 2A : an embodiment of a welding valve/pinch valve in a first position.
FIG. 2B : an embodiment of the welding valve/pinch valve of FIG. 2A in a second position.
FIG. 2C : an embodiment of the welding valve/pinch valve of FIG. 2A in a third position.
FIG. 3 : a first embodiment of a magnetically actuated welding valve/pinch valve.
FIG. 4 : a second embodiment of a magnetically actuated welding valve/pinch valve.
FIG. 5 : a first embodiment of a pneumatically/hydraulically actuated welding valve/pinch valve.
FIG. 6 : a second embodiment of a pneumatically/hydraulically actuated welding valve/pinch valve.
FIG. 7 : an embodiment of a motor actuated welding valve/pinch valve.
FIG. 8 : a schematic representation of clamping heads/welding heads that are heated by electric resistance.
FIG. 9 : a schematic representation of a magnetically operated clamping head/friction welding head.
FIG. 10 : a schematic representation of a motor operated clamping head/friction welding head.
FIG. 11 : a schematic representation of electric HF (high frequency) clamping heads/welding heads.
FIG. 12 : a schematic representation of an integrated hose-cutting device.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
FIG. 1 shows a schematic representation of a metering device, in which the welding devices, designed according to the invention, are used as control valves. Such devices, which lend themselves well to both controlling a volume flow through a hose as well as to welding the hose to close it, are referred to below as welding valves 12 .
A purpose of the metering device 10 is to dispense a metered fluid from a large volume supply container 14 into a plurality of target containers 16 of smaller volume. An associated requirement is that the quantity that is to be dispensed respectively to the target containers must be adhered to exactly. The target containers 16 are constructed as flexible plastic bags that are connected, preferably as one piece or by material bonding, to a connecting hose system 18 . The connecting hose system 18 in the illustrated embodiment consists of a common hose coupling 182 that splits up into a plurality of individual hoses 184 . The common hose coupling 182 is connected to the output of a pump 20 . Each individual hose 184 is connected to its assigned target bag 16 . Upstream of its connecting point with the respective target bag 16 , each connecting hose 184 is pinched between the pinching jaws of a welding valve 12 according to the invention. The pump 20 has an output, to which the common hose coupling 182 of the hose system 18 is attached. The input side of the pump is connected to the supply container 14 through an additional connecting hose 22 .
The target bags 16 in the illustrated embodiment are stored on a stacking shelf 24 , which in turn is disposed on a balance 26 . The balance 26 , the welding valves 12 and preferably, as shown in the illustrated embodiment, also the pump 20 are connected to a control unit 30 through control lines 28 . The control unit 30 receives weighing signals from the balance 26 and sends, according to the specified rules, the control commands to the welding valves 12 and preferably to the pump 20 . The rules of procedure, according to which the evaluation of the weighing signals and the actuation of the welding valves 12 and the pump 20 are executed, are stored in the control unit 30 , preferably as software. A typical process sequence for the illustrated metering device could run as follows:
In the initial state, i.e. when all of the hose connections are established, as shown and explained above, and the individual connecting hoses 184 are pinched between the pinching jaws of the welding valves 12 , all of the welding valves 12 are activated to “close.” That is, their pinching jaws are brought so far together that the lumen of the pinched connecting hose 184 is completely closed. In this state a volume flow through the connecting hose system 18 is not possible. Prior to the start of the actual metering operation, the balance 26 is tared to a base value, preferably set to “zero.” Then the pump 20 is started. In this respect an air venting hose, which is not shown in FIG. 1 , can be provided; and the air that may be found in the connecting hose system 18 can be blown out through the air venting hose. In order to fill a first target bag 16 , for example, the target bag 16 , shown at the very bottom in FIG. 1 , the corresponding welding valve 12 is opened. That is, the pinching jaws of the welding valve are pulled so far apart that at least a partial lumen of the corresponding connecting hose 184 is released; and a volume flow of the metered fluid from the supply container 14 into the active target bag 16 is enabled. During the bag filling operation, the weight increase of the entire arrangement positioned on the balance 26 is measured in short time intervals, preferably almost continuously; and the measurement results are reported to the control unit 30 . This control unit regulates the volumetric flow rate by suitably controlling the active welding valve 12 . In this respect the person skilled in the art is familiar with the typical control algorithms for implementing a gravimetric metering procedure using a control valve. At the end of the bag filling operation the active welding valve 12 is closed again. That is, the pinching jaws of the welding valve are brought so far together that the lumen of the corresponding connecting hose 184 is completely closed again.
In the next step of the process, the heating device of the active welding valve is activated. This arrangement allows the connecting hose 184 to be heated at least up to its softening temperature; and at the same time the pinching pressure, exerted on the connecting hose by the pinching jaws of the welding valve 12 , is maintained. In this case it is not absolutely necessary that the pinching pressure be held exactly constant. Depending on the choice of hose material, wall thickness, cross section, heating procedure, etc., a variation of the pinching pressure, for example, as a function of the temperature or the material softening, is also conceivable. The only crucial factor is that the pinching pressure be not reduced to such an extent that the lumen of the hose opens again. The softening of the material produces a weld. That is, the inner walls of the connecting hose 184 that are pinched together are connected by material bonding. Then the connecting hose 184 of the target bag 16 that has just been filled is permanently closed. Finally the filled target bag 16 can be severed, as a function of the specific configuration of the welding valve 12 , from the rest of the hose system 184 by severing the generated welding point.
Thereafter the process described above for a single target bag 16 is repeated in succession for the rest of the target bags 16 . Each new bag filling operation can be introduced with a re-taring of the balance 26 . The pump 20 can run continuously or can be started again for each new bag filling operation and then stopped again after the bag filling operation. All of the essential parameters of the bag filling operation are stored preferably by the control unit 30 and can be printed out by an attached printer, for example, as adhesive labels for the individual bags.
FIGS. 2A-2C provide schematic representations of an inventive welding valve 12 in three different working phases. In this embodiment a connecting hose 184 is pinched between the pinching jaws 122 and 124 of the welding valve. FIG. 2A shows a working phase, in which the pinching jaws 122 , 124 are brought so far together that even though the free lumen 186 of the connecting hose 184 between the pinching jaws 122 , 124 is obviously constricted, it still allows a (reduced) volume flow through the connecting hose 184 . In FIG. 2B the pinching jaws 122 , 124 are brought even closer together, so that the interior sides of the hose walls 188 touch each other. That is, the lumen 186 of the hose is completely closed in the region between the pinching jaws 122 , 124 . In this state a volume flow through the connecting hose 184 is not possible. However, the lumen 186 can be opened again by opening, i.e. pulling apart, the pinching jaws 122 , 124 . Finally FIG. 2C shows a phase, in which the pinching jaws 122 , 124 are brought together to the maximum extent; and the heating device, which is not shown separately in FIGS. 2A-2C , is activated. The heat buildup in the connecting hose 184 to at least its softening temperature causes the hose walls 188 that have made contact with one another to be welded to one another. The result is a welding point (i.e. one or more point locations, lines, areas or volumes), which is provided with the reference numeral 190 and at which the lumen 186 of the connecting hose 184 is permanently closed due to the material bonding of its hose walls 188 .
In the depicted embodiment the pinching jaws 122 , 124 have a cutting projection 126 at opposite locations. Between the cutting projections 126 the connecting hose 124 is compressed to a greater extent than in the region of the rest of the welding point 190 . This arrangement allows the softened hose material to flow between the cutting projections 126 to the external environment, with the result that the cutting point 192 is completely severed. This process can be facilitated by configuring the heating device in such a way that the hose material between the connecting projections 126 heats up faster than between the other regions of the pinching jaws 122 , 124 .
In FIG. 3 a first embodiment of a welding valve according to the invention is shown in more detail. In this embodiment the function of the welding valve as a control valve is implemented by a spring-biased electromagnetic drive. Connected to the pinching jaw 122 , which may be found at the top in FIG. 3 , is a tappet 32 , which is constructed preferably as a soft iron core and which is surrounded by a coil 34 . The coil 34 is connected to a controllable direct voltage source, with which the lift of the tappet 32 and, with it, the pinching pressure, which the pinching jaw 122 in interaction with the pinching jaw 124 , which may be found at the bottom in FIG. 3 , exerts on the pinched hose 184 , can be controlled. In the depicted embodiment the pinching jaw 122 is spring biased with a spring 36 in such a way that when the coil 34 is de-energized, the valve is switched to “closed.” That is, the electromagnet 32 / 34 acts antagonistically to the spring 36 .
Furthermore, two different heating devices are shown in FIG. 3 .
The pinching jaw 122 , which may be found at the top in FIG. 3 , is an electromagnetic vibration heating device 38 ; and the pinching jaw 124 , which may be found at the bottom in FIG. 3 , is assigned a piezoelectric vibration heating device 40 . The details of these design variants shall be described below in conjunction with the FIGS. 8 and 9 . It should be noted that the illustrated heating devices 38 , 40 are preferably not implemented, as suggested in FIG. 3 , jointly in a welding valve 12 . Rather, preferably only one sort of heating device is realized in a welding valve 12 . At the same time it is possible to both equip each of the two pinching jaws 122 , 124 with a heating device and also to provide only one of the pinching jaws 122 , 124 with a heating device. When confronted with a specific problem, the person skilled in the art can easily solve such questions relating to the layout.
FIG. 4 shows a modification of the welding valve 12 from FIG. 3 . In this embodiment there is no bias spring 36 . Therefore, when this welding valve 12 is in the de-energized state, it will move automatically into the “open” state due to the intrinsic elasticity of the pinched hose. Moreover, the aforesaid with respect to the welding valve 12 in FIG. 3 also applies.
FIG. 5 shows an alternative implementation of the control valve function of the welding valve according to the invention. The pinching jaw 122 , which may be found at the top in FIG. 5 , merges into a piston 42 , which forms a pressure chamber 46 in a housing 44 . The pressure chamber 46 is connected to a pressure line, through which a pressure medium, for example, a hydraulic fluid for realizing a hydraulic system or a compressed gas for realizing a pneumatic system, can be conveyed into the pressure chamber 46 . When the pressure in the pressure chamber 46 is increased, the piston 42 is raised upwards against the pressure of the spring 36 that prestresses the pinching jaw 122 in the “closed” direction. That is, the pinching pressure on the pinched hose is reduced. Reduction of the pressure in the pressure chamber 46 lowers the lift force acting on the spring 36 , so that the pinching jaw 122 descends. Hence, in a depressurized state the welding valve 12 is in its “closed” position. Since this embodiment does not offer the possibility of increasing the pinching pressure hydraulically or pneumatically by way of the baseline pressure of the spring 36 , the spring 36 is configured preferably so strong that it alone suffices to guarantee a total lumen closure of the pinched hose as well as a pinching pressure necessary for the welding operation. Moreover, the aforesaid with respect to the welding valve 12 in FIG. 3 also applies.
FIG. 6 shows a modification of the welding valve 12 from FIG. 5 . In this embodiment there is no bias spring 36 , so that the piston 42 has to be actuated pneumatically and/or hydraulically in both the “closed” direction and also in the “open” direction. For this purpose there is an additional pressure chamber 50 above the piston 42 , which is connected to a second pressure line 52 . As a result, the pinching pressure, acting on the pinched hose, is directed essentially by the differential pressure into the pressure chambers 46 and 50 . Moreover, the aforesaid with respect to the welding valve in FIG. 5 also applies.
FIG. 7 shows an embodiment of the inventive pinch valve 12 , in which the control valve function is implemented with a mechanical spindle drive. To this end the pinching jaw 122 , which may be found at the top in FIG. 7 , is connected to a threaded nut 54 having an inside thread, in which a threaded spindle 56 is disposed. This threaded spindle in turn can be rotated about its longitudinal axis by a motor 58 . This embodiment does not provide an initial stress, for example, using a bias spring. However, in the event of a correspondingly coarse pitch design of the thread of the threaded nut 54 and the threaded spindle 56 , a mechanical tensioning may also be practical. Moreover, the aforesaid with respect to the welding valve 12 in FIG. 3 also applies.
FIG. 8 is a highly simplified schematic representation of an electromagnetic vibration heater, which can be assigned to a pinching jaw 122 of a welding valve 12 according to the invention. In this depicted embodiment the pinching jaw 122 has a soft iron base plate or a permanent base plate that is surrounded by a coil 38 . The coil 38 is connected to an alternating current source 60 , so that when the coil 38 is supplied with current, an axial vibration of the pinching jaw 122 is generated. This vibration, which is pushed away from the material of a pinched hose, generates friction in this hose, so that the hose heats up. As soon as the hose heats up sufficiently, the material softens; and this material softening in turn results in a welding of the pinched hose 184 at an adequately high baseline pressure. As an alternative, the pinching jaw 122 could also be mounted rotatably about its longitudinal axis; and its base plate could have magnetic segments which are spaced apart from one another in the circumferential direction in the manner of an electric motor. These magnetic segments are surrounded by a suitable coil arrangement. A suitable actuation of the current feed permits a rotation or rotative vibration of the pinching jaw 122 to be generated; and the pinched hose can be heated through the resulting friction.
FIG. 9 shows an alternative design variant for heating a pinched hose by friction. In this embodiment the pinching jaw 122 is mounted on a piezoelectric base plate, to which a suitable alternating voltage is applied. The piezoelectric effect causes the piezoelectric base plate to expand and to shrink, so that the result is a vibration of the pinching jaw 122 . Depending on the specific configuration of the piezo base plate 40 , a number of diverse vibrations of the pinching jaw 122 , for example axial, lateral or rotative, can fulfill the objective.
FIG. 10 shows an alternative heating device, in which the pinching jaws 122 , 124 are provided with resistance heating elements 64 . These resistance heating elements are connected to a direct or alternating voltage source and heat up in a manner known in the prior art. If the material of the pinching jaws 122 , 124 is properly chosen with a preferably high thermal conductivity, for example, copper or brass, then the electrically generated heat can be easily transferred in a targeted way to the pinched hose.
FIG. 11 shows an electric high frequency heating device, in which the pinching jaws 122 , 124 act as the “plates” 66 a , 66 b of an electric parallel plate capacitor. The capacitor is an essential part of an electric oscillating circuit, which can comprise additional electric elements, such as an ohmic resistor 68 and a coil 70 . The electric oscillating circuit is excited, preferably in resonance, by an alternating voltage source. If the resonance frequency of the oscillating circuit is tuned to the resonance frequency of the molecular dipoles in the wall material of the hose, then these molecular dipoles can be excited to oscillate by way of the alternating field applied to the capacitor, a feature that becomes apparent in the heat buildup of the wall material.
FIG. 12 shows a preferred further development of the invention that is independent of the implementation of the control valve function and the implementation of the heating function. The pinching jaw 122 , which is shown on the left in FIG. 12 , has an axial cutting channel 74 . The cutting channel 74 conceals an axially movable cutting blade 72 . This cutting blade can slide axially under influence of a drive (not illustrated) and, in particular, between a protective position, which is shown by a blade 72 , which is colored in black in FIG. 12 , and a cutting position, which is shown as a blade 72 bounded by dashed lines in FIG. 12 . In the protective position the cutting edge of the cutting blade 72 is retracted into the pinching jaw 122 . In the cutting position the cutting edge is pushed beyond the front edge of the pinching jaw 122 and is received preferably in a corresponding receiving channel 76 of the opposite pinching jaw 124 . The person skilled in the art can see that a hose (not shown in FIG. 12 ), which is pinched between the pinching jaws 122 , 124 , is severed in this cutting position. The severing operation takes place preferably after completion of the welding operation of the pinched hose in the center of the resulting welding point.
The embodiments discussed in the specific description and shown in the figures are only illustrative exemplary embodiments of the present invention. In light of the present disclosure the person skilled in the art is provided with a broad spectrum of possible design variations. In particular, the shape of the pinching jaws 122 , 124 can be adjusted to the desired shape of the welding point and can deviate significantly from the shapes that are shown in the present disclosure. Even the specific choice of the implementation of the control valve function is just as immaterial for the invention as the specific implementation of the heating or welding function respectively. Furthermore, the metering function according to the invention can be configured in a different way than shown, in particular with more or less target containers 16 and/or more supply containers 14 and with additional or alternative components, which are not illustrated. For example, the volume flow from the supply container(s) 14 to the target bags 16 can also take place without the use of a pump 20 , for example, by applying pressure to the target container(s) 16 or can be gravity driven. Instead of a stacking shelf 24 , in which the target bags 16 are arranged one above the other, it is possible to use an arrangement, in which the target bags are arranged side by side, for example, in a rack.
In other words, the above description of various embodiments has been given by way of example. From the disclosure given, those skilled in the art will not only understand the present invention and its attendant advantages, but will also find apparent various changes and modifications to the structures and methods disclosed. The applicant seeks, therefore, to cover all such changes and modifications as fall within the spirit and scope of the invention, as defined by the appended claims, and equivalents thereof. | A welding device for the sealing welding of thermopolastic hoses ( 184 ), includes a clamping device ( 12 ) with at least two clamping jaws ( 122, 124 ), of which at least one is movable and between which a hose ( 184 ) which is to be welded can be clamped, wherein the clamping device ( 12 ) has a heating devices ( 38; 40; 64 ) which is coupled to a control unit ( 30 ) and is configured to heat the hose clamped between the clamping jaws ( 122, 124 ). The invention is distinguished in that the at least one movable clamping jaw ( 122 ) is actuable with a controllable, bidirectional actuator ( 32, 34; 42 - 52; 54, 56, 58 ) which is coupled to the control unit ( 30 ) in such a manner that the clamping pressure acting on the hose ( 184 ) can be adjusted independently of the heating device. | 1 |
BRIEF DESCRIPTION OF THE INVENTION
This invention relates to a tufting machine and is more particularly concerned with a computer controlled tufting machine and a process of controlling the parameters of operation of a tufting machine.
In tufting machines, it is necessary to synchronize the feed of the backing material across the bed rail with the speed of reciprocation of the needles so as to produce a prescribed number of stitches per inch in a longitudinal direction in the backing material. This determines the number of tufts per linear inch of the backing material. In the event that it is desired to change the number of stitches per inch, it has been necessary in the past, to change the sheaves on the gear box which is connected to the in-feed and out-feed rolls of the tufting machine. Thus, generally speaking, it is difficult to change the number of stitches per inch which are sewn by the tufting machine in a manner to arrive at a predetermined weight for a square yard of such carpeting. Sometimes this involved trial and error as to the size sheave or pulley to be employed on the gear reducer for receiving the timing belt from the main drive shaft. Thus, it was quite time consuming in order to change from producing one particular weight of carpet to producing either a lighter or heavier weight of carpeting, using the same yarn.
In the past, when it was necessary to change pile heights for different patterns of goods, it was necessary to manually adjust the height of the bed rail of the tufting machine so as to have the machine produce a higher or lower tuft. Again, the problem presented itself of predetermining the amount of adjustment of the bed rail which would be necessary in order to produce a fabric having a prescribed density. Usually the change in drive of the in-feed and out-feed rolls and the change in position of the bed rail of the tufting machine required that sample carpets be sewn after each change in order to provide swatches which could be weighted to thereby determine whether or not the changes were sufficient to achieve the desired result.
While counters have been placed on the backing material in order to determine the linear length of carpeting which is produced by a tufting machine, it has, in the past, been left to the operator of the machine to determine when a prescribed linear length of carpeting has been produced to a particular job order. As a result, there are usually overruns of each pattern of carpet so as to assure that the desired amount of carpet has been produced.
Briefly described, the present invention includes a conventional tufting machine which in the present embodiment is a cut pile tufting machine, a yarn feed mechanism for simultaneously feeding a plurality of yarns to the needles of the tufting machine, in-feed and out-feed rolls for the backing material, and synchronous motors the speeds of which are controlled by the computer. One synchronous motor controls the feed of the backing material and the other synchronous motor is attached to the yarn feed mechanism for feeding each needle a prescribed amount of yarn. There are two encoders, one encoder reads the speed of the main drive shaft and the other encoder determines the absolute height of the bedrail. The signals from these encoders are fed to the computer. Programs in the computer prescribe such parameters as the number of stitches to the inch, the weight of the face yarn per square yard, the depth of stroke of the needles, the amount of yarn that is fed to each needle per stroke, the speed of the tufting machine, and the adjustment of the bed rail to provide the appropriate length of tufting. Also prescribed by the software is the linear length of carpeting to be produced according to the particular pattern prescribed.
A number of different patterns and orders for those patterns can be stored in the computer so that there is essentially no interruption between producing one particular pattern and the next pattern to be produced. The computer through the control of the main motors will shut the machine on and off and a stop motion machine is connected to the computer so as to automatically shut down the machine in the event of a break in the yarn.
Accordingly, it is an object of the present invention to provide a tufting machine which requires little attention of an operator and which will inexpensively and efficiently produce tufted fabric.
Another object of the present invention is to provide a tufting machine which can be programmed to produce a prescribed length of tufting.
Another object of the present invention is to provide a tufting machine which can be programmed to produce successively, different prescribed lengths of tufting of different designs.
Another object of the present invention is to provide a tufting machine in which the stitches per inch sewn by the needles can be readily and easily changed as desired.
Another object of the present invention is to provide a tufting machine in which the setting for pile height can be varied as desired.
Another object of the present invention is to provide a tufting machine in which the density of the tufted product can be changed, without the necessity of producing samples to determine whether the appropriate density has been achieved by an adjustment of the machine.
Another object of the present invention is to provide a tufting machine which will automatically produce successive lengths of tufting which have been programmed into the machine.
Another object of the present invention is to provide a process of tufting which will enable an operator to control the product produced from a tufting machine from a remote location.
Other and further objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings wherein like characters of reference designate corresponding parts throughout the several views.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic rear elevational view of a tufting machine constructed in accordance with the present invention.
FIG. 2 is a side view elevational view of one side of the machine depicted on FIG. 1.
FIG. 3 is a sectional view illustrating the backing material transported over the motor-driven bed rail.
FIG. 4 is a mechanical diagram for the operation of the computer-controlled tufting machine.
FIG. 5A is part of an electrical flow diagram for the operation of the computer-controlled tufting machine.
FIG. 5B is the other part of the diagram of FIG. 5A.
FIG. 6 is an illustration of the main operation interface menu-driven screen display.
FIG. 7 is an illustration of the STYLE INFORMATION menu-driven screen display.
FIG. 8 is an illustration of the DISPLAY RUN LIST menu-driven screen display.
FIG. 9 is an illustration of the DISPLAY STYLE INFORMATION menu-driven screen display.
FIG. 10 is an illustration of the DISPLAY ADDITIONAL STYLE INFORMATION screen display.
FIG. 11 is an illustration of the PRODUCTION AND OPERATION display.
DETAILED DESCRIPTION
Referring now in detail to the embodiment chosen for the purpose of illustrating the present invention, numeral 10 in FIGS. 1 and 2 denotes generally the frame of a conventional cut pile tufting machine which includes a conventional main drive shaft 11 driven by belts 12 from main motors M1 and M2.
The shaft 11 reciprocates a plurality of push rods 13 which reciprocate a needle bar 14 which carries a plurality of needles 15. Yarn 16 is supplied to the tufting machine from a yarn supply such as a creel 17, the yarn 16 passing through a yarn feed mechanism or a yarn control 20 and thence to the respective needles 15.
The yarn feed mechanism 20 includes four transversely disposed rollers 21 over which the yarn 16 pass successively and then down to the needles 15. These rollers 21 are synchronized with each other to feed the yarn and are controlled by a synchronous motor M3 through a gear reducer 22.
The base fabric or backing material 23 is fed in an essentially horizontally linear path from a roll of backing material up over a front of input drive roll or feed roll 24, passing across the machine over an idler roller 25 and a pin roll 26 and then over a rear or output cloth drive roll or discharge roll 27. A timing belt 28 passing around sheaves or rollers 29 on the drive shafts 31 of the rolls 24 and 27 synchronize the rotation of the shafts 31 so as to rotate the front roll 24 at a slightly lower speed than the rear roll 27, to thereby assure that the backing material 23 is in a taut condition when passing over the bed rail 30 shown in FIG. 3. The pin roll 26 is an idler roller which generates an interrupt signal to the computer for each rotation. The interrupt generated by rotation of the pin roll 26 causes the incrementing of a counter which determines the length of carpet produced.
A motor M4 at the right side of the frame 10 drives a reducers 32 and 18 which in turn drives the rear feed roll 27. Thus, the feed rolls 24 and 27 are driven in synchronization with each other to pass the backing material 23 across the bed rail 30 and beneath the needles 15 for stitching action of the needles 15.
The bed rail 30 is moved upwardly and downwardly as desired by means of motors such as stepping motor M5 which drives through a gear box 37 the bedrail lifts which are screws such as screw 33 which are threadedly carried by brackets such as bracket 34 attached to the frame 10. As is well known, the height of the bed rail 30 will determine how deep the needles 15 sew the loops of yarn which are caught by loopers such as looper 35. The loops are subsequently cut by knives such as knife 36. Since the function of a tufting machine in producing conventional cut pile fabric is well known, a more detailed description of the parts of the tufting machine is not deemed necessary.
According to the present invention, the motors M1, M2, M3, M4 and M5 are respectively controlled so as to dictate the various parameters of the cut pile fabric to be sewn using the machine of the present invention. The motors M1 can be driven either forwardly or rearwardly so that the machine can be rocked back and forth when the bed rail 30 is to be raised so as to permit the cutting of the loops of yarn which are held by the looper. Otherwise, the raising of the bed rail 30 may cause the loops of yarn 16 to break several of the loopers, particularly when the loopers have been subjected to metal fatigue.
FIG. 4 shows a mechanical diagram for the operation of computer-controlled tufting machine 10. The servomoters M3 and M4 drive the yarn feed roll 21 and cloth feed rolls 24, 27, in ratio to the speed of the main shaft 11 by electronic means through gear reducers 22, 32, 18 and tension belt 28. The yarn feed reducer 22 on the yarn feed servomotor M3 changes the ratio beween revolutions of the main shaft 11 to fractions of a revolution of the yarn feed roll 21 to vary the yarn feed between 0.35 and 3 inches of yarn per revolution of the main shaft. Similarly, the cloth feed reducers 32, 18 change the ratio between revolutions of the main shaft 11 to the fraction of the revolution of the front and rear cloth feed drive rolls 24, 27 to vary the backing feed rate between 0.06 and 0.2 inches of backing per revolution of the main shaft 11.
The main shaft motors M1, M2 rotate the main shaft 11 which drives the reciprocating needle bar 14. An optical encoder 40 mounted on main shaft 11 and consisting of a light emitting diode, a photocell and a slotted disk between the diode and photocell, is an incremental shaft-angle encoder that follows the rotation of the main shaft and transmits an electrical input signals to both the cloth feed motor M4 and to the yarn feed motor M3. Bedrail lift motor M5 is a stepper motor controlled by computer 50 and raises and lowers the bedrail 30 through the gear box 37. An absolute encoder 45 located on the output shelf of gear box 37 senses the position of bedrail 30. Also shown in FIG. 4 is electric bedrail hydraulic pump 38 which cooperates with motor M5 to operate bedrail clamp 39 to lock the bedrail 30 in place when motor M5 is stopped after it is raised or lowered the bedrail 30. The absolute encoder 45 is driven from main shaft 11 provides a binary-coded-decimal coded digital output word for each discrete displacement increment of the bedrail.
The electrical components of the computer-controlled tufting machine 10 are shown in the block diagram of FIG. 5A and 5B. Microprocessor-based computer 50 provides status information to the operator through operation interface 51 which in the preferred embodiment is a touch screen. Permanent style information is stored in battery backed-up random access memory. In an alternate embodiment, the interface may be a keyboard (not shown) for input and to a disk drive (not shown) for permanent storage of style information on disk. In still another alternate embodiment the interface 51 may consist of a plurality of microcomputers (not shown) networked to a central computer (not shown) to permit control of a multiplicity of tufting machines from one source. Style informaction and job orders would then be entered and stored at the location of the central computer. The computer 50 also interfaces with a printer 52 to provide automatically run data on operation of the tufting machine along with statistical data on efficiency of operation of the machine during a specific period of time such as a work shift duration.
The computer 50 controls the setting of the indexer 41 for the yarn feed and the indexer 42 for cloth feed 42 which, in turn, controls operation of yarn feed motor M3 and cloth feed motor M4, respectively, through servo drives 43 and 44. The resolver 43a on yarn feed motor M3 provides position information to the yarn feed servo drive 43. Similarly, the resolver 44a on cloth feed motor M4 provides feedback to the cloth feed servo drive 44 to control the rate of feed of the backing material 23.
The indexers 41, 42 are set with the correct ratio information through computer 50. The ratio information is fed to the gear reducers 23, 32 which control the ratio between revolutions of the main shaft 11 to fractions of revolutions of the yarn feed roll 21 and the cloth feed roll 24, respectively. Changing the two ratios determines the style of carpet, i.e., the depth and density of the carpet. The encoder 40 on the main shaft 11 follows the rotation of the main shaft 11 and sends a pulse to the indexers 41, 42 for every rotation of the main shaft 11. The indexers 41, 42 comprise electrically erasable programmable read only memory (EEPROM). The input signals from main shaft encoder 40 are used by each indexer 41 or 42 to output a pulse stream to the respective servo drive 43, 44 which control operation of the yarn and cloth feed servo motors M3, M4. Each pulse from the indexers 41, 42 is translated into steps on servo drives 43, 44. For the yarn feed rolls 21, there are between 0.5-5 steps on the servo drive 43 for each pulse from the encoder 40. The computer 50 is also used to set up interrups and an interrupt occurs for every complete revolution of the cloth roll 27. The cloth roll 27 is a spike roll which might typically have a circumference of 12.566 inches. Each interrupt results in the incrementing of a counter representing the linear length of carpet produced.
SYSTEM OPERATION
When the computer-controlled tufting machine 10 is powered up. the resident software program defining the operator interface 51 goes through a system initialization cycle wherein the graphics mode is set, the indexers 41, 42 for the yarn feed and cloth feed are reset, the touch screen 70 is initialized, interrupts are enabled, timers are initialized and the tufting machine 10 is "locked out" to prevent inadvertent operation.
After the system is initialized the first menu is displayed. Each menu requires operator interaction before another menu can be displayed. As indicated in FIG. 6, the machine operator is given the choice on touch screen 53 of setting style information block 53a, selecting the maintenance mode block 53b or selecting the production mode block 53c. If STYLE INFORMATION block 53a were selected by operator the operator would touch on that area of the display screen 53, whereby the operator is provided with the screen display 153 in FIG. 7. As indicated in FIG. 7 the choices available are creating or adding to the run list block 153a, displaying the style numbers 153b in the style data base, or changing an existing style 153c in the style data base. There is an exit option available on each screen, after the initial one, which will enable the operator to back up to the immediately preceding menu.
If CREATE OR ADD TO RUN LIST block 153a were chosen, then the operator is given the screen display 253 depicted in FIG. 8, which lists the present run list, if any, in columnar format. The first column 253a displays the order number, the second column 253b the style number, the third column 253c the batch number, the fourth column 253d the number of rolls and the final column 253e the number of feet of carpet to run on a particular job. The FEET TO RUN is the product of the number of rolls and the roll length, both of which are user inputs. The operator has a numeric touch sensitive key pad 253f on the right half of the display screen 53 enabling him to select any digit or to delete an erroneous entry. The operator selects from the add block 253g, move block 253h, or erase block 253i options. If ADD is selected, the screen display will prompt the operator, in the area of the display above the present run list, for a style number, a batch number, the number of rolls, and a run length. The order number is incremented automatically in the add mode and the entire job is added to the run list. The operator touches the MOVE block 253h on screen 253 to move a job order from one point on the run list to another which can be either higher or lower. The operator is again prompted on the screen for input in the above mode. The key pad is used to select both the order number of the job to be moved and the order number for it to be moved to on the run list. The ERASE block 253i is touch activated when the operator wants to erase a job entirely from the run list. The touch key pad is used to enter the order number to remove from the run list in response to screen prompts.
When DISPLAY STYLE NUMBERS pad 153b is selected, the operator is presented with a list of style numbers that are presently stored in memory. An EXIT pad is provided to leave this function.
When EDIT STYLE INFORMATION pad 153c is selected, the operator is presented with display 353 depicted in FIG. 7. The operator first inputs a style number. If the style number does not already exist in memory, then all the variables which are required to define that style are then initialized to zero by the computer 50. If the style number does not already exist then the computer 50 loads from permanent storage the style information associated with the style number. The user then edits the information relating to that style. The user is prompted for the associated stitch rate, yarn feed rate, bedrail height, and tufting machine speed in revolutions per minute. The numeric touch key pad 353f is again depicted on the right half of the screen 353 for user data entry. A second menu 453 depicted in FIG. 10 is then presented for entry of backing type, the number of front and rear cams required, the tufted width, the yarn size (denier and ply), the roll length, and carpet weight (in ounces).
The maintenance mode (Block 53b) will allow the following operations:
1. Running only the cloth or yarn feed motors (M4 or M3) for threading the machine or changing the backing 23;
2. Setting the stopping position of the needle bar 14; and
3. Raising or lowering the bedrail 30 for system tests.
Selection of PRODUCTION & OPERATION block 53c on the screen displayed in FIG. 6 will present the user with the screen 553 display depicted in FIG. 11. The style number at the top of the run list is read and the corresponding style information is retrieved from the permanent storage medium (e.g. random access memory) and displayed on the left side of the screen. STAND-BY is written to the system status line on the screen display. The computer 50 loads the indexers 41, 42 with the correct ratio information. After the indexers 41, 42 are loaded, the machine lock-out is removed enabling the machine to operate. MACHINE READY is then written to the system status line on the screen display 553. The system is initialized to non-active status and then to screen lock. The tufting machine 10 can be operated now, but efficiencies will not be calculated.
At this point the machine is idle and waiting for operator input. The operator starts the operation of the machine by the separate machine controls. FIG. 11 indicates that there are six possible operator inputs having to do with calculation and display of production run statistics. The ADDITIONAL INFO option displays the additional information shown in FIG. 10. The LOCKED option causes the screen lock-out to be toggled. The START, STOP, RESET and EXIT options are affected by the screen lock-out. When the screen 553 is not locked-out, START initializes efficiency calculations, STOP suspends efficiency calculations, RESET serves to reinitialize efficiency calculations and sets the timers to zero. EXIT returns the display screen to that shown in FIG. 6. As the batch is being produced on the tufting machine 10, the information indicated on the lower part of the menu is displayed and continuously updated at the screen refresh rate. This information includes batch number, requested feet, total feet for the batch, total feet for the shift, run time for shift, and efficiency (percent).
It is to be understood that the invention is not limited by the specific illustrative embodiments described herein, but only by the scope of the appended claims. | A tufting machine is provided with separate motors which drive the main drive shaft, control the feed of the backing material and control the bedrail height. A computer is electrically connected to these motors and to the yarn feed controls. The software indicates patterns to be produced, informing the computer to control the number of stitches per inch of backing, the weight of face yarn per square yard, the pile height, the amount of yarn fed to the needles and the linear length of carpeting produced. The computer also dictates the schedule by which prescribed lengths of additional patterns are produced by the tufting machine and can control a number of such tufting machines. When the pile height is to be changed, the computer automatically controls the main motors for rocking the main shaft, to reciprocate the needles while controlling the yarn feed controls and the motor to the bedrail. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of prior U.S. application Ser. No. 12/328,096 filed Dec. 4, 2008.
BACKGROUND OF THE INVENTION
[0002] Ion implanters are commonly used in the production of semiconductor wafers. An ion source is used to create a beam of charged ions, which is then directed toward the wafer. As the ions strike the wafer, they impart a charge in the area of impact. This charge allows that particular region of the wafer to be properly “doped”. The configuration of doped regions defines their functionality, and through the use of conductive interconnects, these wafers can be transformed into complex circuits.
[0003] A block diagram of a representative ion implanter 1 is shown in FIG. 1 . Power supply 2 supplies the required energy to the ion source 3 to enable the generation of ions. An ion source 3 generates ions of a desired species. In some embodiments, these species are mono-atoms, which are best suited for high-energy implant applications. In other embodiments, these species are molecules, which are better suited for low-energy implant applications. The ion source 3 has an aperture through which ions can pass. These ions are attracted to and through the aperture by electrodes 4 . These ions are formed into a beam 95 , which then passes through a mass analyzer 6 . The mass analyzer 6 , having a resolving aperture, is used to remove unwanted components from the ion beam, resulting in an ion beam having the desired energy and mass characteristics passing through resolving aperture. Ions of the desired species then pass through a deceleration stage 8 , which may include one or more electrodes. The output of the deceleration stage is a diverging ion beam.
[0004] A corrector magnet 13 is adapted to deflect the divergent ion beam into a set of beamlets having substantially parallel trajectories. Preferably, the corrector magnet 13 comprises a magnet coil and magnetic pole pieces that are spaced apart to form a gap, through which the ion beamlets pass. The coil is energized so as to create a magnetic field within the gap, which deflects the ion beamlets in accordance with the strength and direction of the applied magnetic field. The magnetic field is adjusted by varying the current through the magnet coil. Alternatively, other structures, such as parallelizing lenses, can also be utilized to perform this function.
[0005] Following the angle corrector 13 , the ribbon beam is targeted toward the workpiece. In some embodiments, a second deceleration stage 11 may be added. The workpiece is attached to a workpiece support 15 . The workpiece support 15 provides a variety of degrees of movement for various implant applications.
[0006] Referring to FIG. 2 , a traditional ion source that may be incorporated into the ion implanter 1 is shown. The ion source shown in FIG. 2 may include a chamber housing 10 that defines an ion source chamber 14 . One side of the chamber housing 10 has an extraction aperture 12 through which the ions pass. In some embodiments, this aperture is a hole, while in other applications, such as high current implantation, this aperture is a slot or a set of holes.
[0007] A cathode 20 is located on one end of the ion source chamber 14 . A filament 30 is positioned in close proximity to the cathode 20 , outside of the ion chamber. A repeller 60 is located on the opposite end of the ion source chamber 14 .
[0008] The filament 30 is energized by filament supply voltage 54 . The current passing through the filament 30 heats it sufficiently (i.e. above 2000° C.) so as to produce thermo-electrons. A bias supply voltage 52 is used to bias the cathode 20 at a substantially more positive voltage than the filament 30 . The effect of this large difference in voltage is to cause the thermo-electrons emitted from the filament to be accelerated toward the cathode. As these electrons bombard the cathode, the cathode heats significantly, often to temperatures over 2000° C. The cathode, which is referred to as an indirectly heated cathode (IHC), then emits thermo-electrons into the ion source chamber 14 .
[0009] The arc supply 50 is used to bias the ion chamber housing 10 positively as compared to the cathode. The arc supply typically biases the housing 10 to a voltage about 50-100 Volts more positive than the cathode 20 . This difference in voltage causes the electrons emitted from the cathode 20 to be accelerated toward the housing 10 .
[0010] A magnetic field is preferably created in the direction 62 , typically by using magnetic poles 86 located outside the chamber. The effect of the magnetic field is to confine the emitted electrons within magnetic field lines. The emitted electrons, electro-statically confined between cathode and repeller, take the spiral motions along the source magnetic field lines, thus effectively ionize background gases, forming ions (as shown in FIG. 3 ).
[0011] Vapor or gas source 40 is used to provide atoms or molecules into the ion source chamber 14 . The molecules can be of a variety of species, including but not limited to inert gases (such as argon or hydrogen), oxygen-containing gases (such as oxygen and carbon dioxide), nitrogen containing gases (such as nitrogen or nitrogen triflouride), and other dopant-containing gases (such as diborane, boron tri-fluoride, or arsenic penta-fluoride). These background gasses are ionized by electron impact, thus forming plasma 80 .
[0012] At the far end of the chamber 14 , opposite the cathode 20 , a repeller 60 is preferably biased to the same voltage as the cathode 20 . This causes the emitted electrons to be electro-statically confined between cathode 20 and repeller 60 . The use of these structures at each end of the ion source chamber 14 maximizes the interaction of the emitted electrons with the background gas, thus generating high-density plasmas.
[0013] FIG. 3 shows a different view of the ion source of FIG. 2 . The source magnet 86 creates a magnetic field 62 across the ion chamber. The cathode 20 and repeller 60 are maintained at the same potential, so as to effectively confine the electrons, which collide with the background gas thus generate the plasma 80 . The electrode set 90 is biased so as to attract the ions to and through the extraction aperture 12 . These extracted ions are then formed into an ion beam 95 and are used as described above.
[0014] An alternative embodiment of an ion implantation system, plasma immersion, is shown in FIG. 4 . The plasma doping system 100 includes a process chamber 102 defining an enclosed volume 103 . A platen 134 is positioned in the process chamber 102 to support a workpiece 138 . In one instance, the workpiece 138 comprises a semiconductor wafer having a disk shape, such as, in one embodiment, a 300 millimeter (mm) diameter silicon wafer. The workpiece 138 may be clamped to a flat surface of the platen 134 by electrostatic or mechanical forces. In one embodiment, the platen 134 may include conductive pins (not shown) for making connection to the workpiece 138 .
[0015] A gas source 104 provides a dopant gas to the interior volume 103 of the process chamber 102 through the mass flow controller 106 . A gas baffle 170 is positioned in the process chamber 102 to uniformly distribute the gas from the gas source 104 . A pressure gauge 108 measures the pressure inside the process chamber 102 . A vacuum pump 112 evacuates exhausts from the process chamber 102 through an exhaust port 110 in the process chamber 102 . An exhaust valve 114 controls the exhaust conductance through the exhaust port 110 .
[0016] The plasma doping system 100 may further include a gas pressure controller 116 that is electrically connected to the mass flow controller 106 , the pressure gauge 108 , and the exhaust valve 114 . The gas pressure controller 116 may be configured to maintain a desired pressure in the process chamber 102 by controlling either the exhaust conductance with the exhaust valve 114 or a process gas flow rate with the mass flow controller 106 in a feedback loop that is responsive to the pressure gauge 108 .
[0017] The process chamber 102 may have a chamber top 118 that includes a first section 120 formed of a dielectric material that extends in a generally horizontal direction. The chamber top 118 also includes a second section 122 formed of a dielectric material that extends a height from the first section 120 in a generally vertical direction. The chamber top 118 further includes a lid 124 formed of an electrically and thermally conductive material that extends across the second section 122 in a horizontal direction.
[0018] The plasma doping system may further include a source 101 configured to generate a plasma 140 within the process chamber 102 . The source 101 may include a RF source 150 , such as a power supply, to supply RF power to either one or both of the planar antenna 126 and the helical antenna 146 to generate the plasma 140 . The RF source 150 may be coupled to the antennas 126 , 146 by an impedance matching network 152 that matches the output impedance of the RF source 150 to the impedance of the RF antennas 126 , 146 in order to maximize the power transferred from the RF source 150 to the RF antennas 126 , 146 .
[0019] The plasma doping system 100 also may include a bias power supply 148 electrically coupled to the platen 134 . The bias power supply 148 is configured to provide a pulsed platen signal having pulse ON and OFF time periods to bias the platen 134 , and, hence, the workpiece 138 , and to accelerate ions from the plasma 140 toward the workpiece 138 during the pulse ON time periods and not during the pulse OFF periods. The bias power supply 148 may be a DC or an RF power supply.
[0020] The plasma doping system 100 may further include a shield ring 194 disposed around the platen 134 . As is known in the art, the shield ring 194 may be biased to improve the uniformity of implanted ion distribution near the edge of the workpiece 138 . One or more Faraday sensors such as an annular Faraday sensor 199 may be positioned in the shield ring 194 to sense ion beam current.
[0021] The plasma doping system 100 may further include a controller 156 and a user interface system 158 . The controller 156 can be or include a general-purpose computer or network of general-purpose computers that may be programmed to perform desired input/output functions. The controller 156 also can include other electronic circuitry or components, such as application-specific integrated circuits, other hardwired or programmable electronic devices, discrete element circuits, etc. The controller 156 also may include communication devices, data storage devices, and software. For clarity of illustration, the controller 156 is illustrated as providing only an output signal to the power supplies 148 , 150 , and receiving input signals from the Faraday sensor 199 . Those skilled in the art will recognize that the controller 156 may provide output signals to other components of the plasma doping system 100 and receive input signals from the same. The user interface system 158 may include devices such as touch screens, keyboards, user pointing devices, displays, printers, etc. to allow a user to input commands and/or data and/or to monitor the plasma doping system via the controller 156 .
[0022] In operation, the gas source 104 supplies a primary dopant gas containing a desired dopant for implantation into the workpiece 138 . The gas pressure controller 116 regulates the rate at which the primary dopant gas is supplied to the process chamber 102 . The source 101 is configured to generate the plasma 140 within the process chamber 102 . The source 101 may be controlled by the controller 156 . To generate the plasma 140 , the RF source 150 resonates RF currents in at least one of the RF antennas 126 , 146 to produce an oscillating magnetic field. The oscillating magnetic field induces RF currents into the process chamber 102 . The RF currents in the process chamber 102 excite and ionize the primary dopant gas to generate the plasma 140 .
[0023] The bias power supply 148 provides a pulsed platen signal to bias the platen 134 and, hence, the workpiece 138 to accelerate ions from the plasma 140 toward the workpiece 138 during the pulse ON periods of the pulsed platen signal. The frequency of the pulsed platen signal and/or the duty cycle of the pulses may be selected to provide a desired dose rate. The amplitude of the pulsed platen signal may be selected to provide a desired energy. With all other parameters being equal, a greater energy will result in a greater implanted depth.
[0024] Note that in both systems, gas is supplied to the chamber, which is used to create the ions that are then implanted in the wafer. Traditionally, these gasses include either elemental gasses, such as hydrogen, argon, oxygen, nitrogen, or other molecules, including but not limited to carbon dioxide, nitrogen tri-fluoride, diborane, phosphorus tri-fluoride, boron tri-fluoride, or arsenic penta-fluoride.
[0025] As described above, these gasses are ionized to produce the desired ions for implantation. For ion source applications, in order to maximize the generation of a specific ion species, several variables must be controlled, including source gas flow, arc current, ion source materials, wall temperature, and others. Similarly, for plasma implantation applications, factors are used to generate a uniform charged species over the wafer region. Factors, such as source antenna design, pressure, power, target bias voltage, wall/target temperature, and others, are modified to produce the desired ion distribution.
[0026] One factor that has not been fully exploited is controlling the characteristics of the incoming source gas. As stated above, different types of gasses are used, depending on the application. However, once a gas is selected, no other modifications are made to that source gas. It would be beneficial to control the composition of the ion species and their spatial distribution by varying the characteristics of the source gas.
SUMMARY
[0027] An ion source includes an ion chamber housing defining an ion source chamber, the ion chamber housing having a side with a plurality of apertures. The ion source also includes an antechamber housing defining an antechamber. The antechamber housing shares the side with the plurality of apertures with the ion chamber housing. The antechamber housing has an opening to receive a gas from a gas source. The antechamber is configured to transform the gas into an altered state having excited neutrals that is provided through the plurality of apertures into the ion source chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 illustrates a block diagram of a representative high-current ion implanter tool;
[0029] FIG. 2 illustrates a traditional ion source used in ion beam applications;
[0030] FIG. 3 shows the major components of the traditional ion source of FIG. 2 ;
[0031] FIG. 4 illustrates a plasma immersion system;
[0032] FIG. 5 shows a first embodiment of a gas injection system used in an ion beam application;
[0033] FIG. 6 shows a second embodiment of a gas injection system used in an ion beam application;
[0034] FIG. 7 shows a third embodiment of a gas injection system used in an ion beam application;
[0035] FIG. 8 shows a fourth embodiment of a gas injection system used in an ion beam application;
[0036] FIG. 9 shows an embodiment of a gas injection system used in a plasma immersion system; and
[0037] FIG. 10 shows a second view of the gas injection system of FIG. 9 .
DETAILED DESCRIPTION
[0038] FIG. 5 illustrates a first embodiment of a gas injection system used in an ion beam application. Traditionally, gas source 40 is in direct fluid communication with source chamber 14 . However, FIG. 5 illustrates the components of the gas injection system according to a first embodiment. In this embodiment, gas source 40 may be in communication with a mass flow controller (MFC) 220 . The MFC is responsible for regulating the flow of gas from gas source 40 to a desired flow rate. The output of the MFC is in fluid communication with adjustable bypass valve 210 and remote plasma source 200 . The outputs from the adjustable bypass valve 210 and the remote plasma source 200 then join together and are in fluid communication with the source chamber 14 .
[0039] The remote plasma source 200 can be of any suitable type. However, those sources having a wide operating range with high-density plasma and/or excited neutral species generation capability are preferred. In one embodiment, a microwave plasma source (Electron cyclotron resonance-type) is used, which can operate at pressures between 10 −6 and 10 −1 torr, generating high-density, highly-charged ionized species and/or highly-excited neutral species. In a second embodiment, a microwave plasma source, such as ASTRON® manufactured by MKS Instruments, is used, which can operate at pressures between 10 −1 torr and atmospheric pressure, while generating defragmented or excited neutrals. In other embodiments, a second indirectly heated cathode (IHC) ion source is used to create the heavy neutrals and ionized species, which are then supplied to the ion source 14 . In other embodiments, a helicon source, an inductively-coupled plasma (ICP) source, a capacitively-coupled plasma source, a hollow-cathode (HC) source, or a filament-based plasma source can be used. The term “remote plasma source” is intended to encompass any device capable of transforming molecules to an altered state. Altered states include not only plasma, but also ions, excited neutrals, and metastable molecules. As is well known, ions are simply atoms or molecules with an electrical charge associated with them, such as BF 2 + . Excited neutrals refer to atoms or molecules, which are still neutral in charge. However, these atoms or molecules have one or more electrons in an excited energy state. Finally, metastable molecules refer to molecule configurations which can be created, such as B 2 F 4 or B 4 F 5 . However, these molecules may not remain in those configurations for long periods of time, as they are likely to recombine or breakdown into more common molecular configurations. Each of these altered states; plasma, ions, excited neutrals and metastable molecules are of interest. Therefore, it is not a requirement that the remote plasma generator actually create a plasma as its output.
[0040] When the remote plasma source 200 is enabled, the molecules from the source gas 40 pass through the MFC 220 and enter the plasma source. Based on the type of remote plasma source and its operating parameters, the source gas can be altered. In certain cases, source gas is acted upon to produce excited neutrals, metastable molecules or ionic molecules. In other cases, the source gas is defragmented into atomic and/or smaller molecular species. In yet other embodiments, the source gas combines to generate heavier or metastable molecules.
[0041] If maximum extraction current of a specific ion species is required, the source gas injection can be tuned accordingly in order to optimize (or maximize) the concentration of that specific ion in the source chamber 14 . As an example, by operating the remote plasma source at low-pressure and high-power, the production of excited neutrals is promoted. As these excited neutrals are introduced into the source chamber 14 , the production of mono-atomic ions and/or multiply-charged ions will be enhanced and, as a result, the extraction of mono-atomic and/or multiply-charged ion current is increased.
[0042] For example, currently, source gasses, such as boron triflouride, are supplied to an ion source chamber. This gas is ionized by the indirectly heated cathode, thereby producing various ion species, such as BF 2 + , BF + , F + , B x F y + and B + . In the current disclosure, the source gas is supplied to a remote plasma source, preferably operating at high power and low pressure. This remote plasma source then produces either excited fragmented neutrals, or various fragmented ionized species. These various species are then supplied to the ion source chamber 14 . Since the composition and energy levels of the supplied gas have been modified, the output of the ion source is similarly affected, thereby creating more ions of a particular species. In this example, more small ionic species, such as B + and BF + are created.
[0043] In other embodiments, the production of heavier ions, such as dimmers, trimers or tetramers is desired. The remote plasma source may be operated at much higher pressure, thereby causing molecules to combine into heavier neutral species or metastable molecules. These excited heavy molecules and metastable molecules are then supplied to the ion source chamber 14 .
[0044] For example, currently, source gasses, such as arsenic and phosphorus, are supplied to a ion source chamber 14 . To create heavier species, the chamber must be operated at low power, and typically the output current is quite low. According to one embodiment, these source gasses can be supplied to the remote plasma source 200 , operating at a much higher pressure than used to create monoatomic species, to create these heavier neutral species, such as As 2 , As 3 , P 2 , P 3 and P 4 . These heavier species are then supplied to the ion course chamber 14 , where they are ionized and extracted into an ion beam. Since the concentration of heavier species is increased through the use of a remote plasma source, the resulting ion beam possesses a greater current.
[0045] While the above description highlights the use of the remote plasma source 200 exclusively, the disclosure is not limited to this embodiment. The use of an adjustable bypass valve 210 allows the mixing of molecular source gas and the output from the remote plasma source 200 . The resultant mixture can be adjusted such that the ratio of the molecular source gas and the output of the remote plasma source can be finely controlled to achieve the desired effect.
[0046] FIG. 6 illustrates a second embodiment of a gas injection system, usable with the ion source chamber of FIG. 3 . In this embodiment, two different source gasses are each in communication with a separate mass flow controller (MFC) 320 , 325 . These MFCs 320 , 325 are each in fluid communication with a remote plasma source 300 , 305 and an adjustable bypass valve 310 , 315 , respectively. Through use of the MFCs, the flow rate of each source gas can be controlled. Additionally, through the use of adjustable bypass valves, the ratio of injected molecular source gas and source gas in altered states can be varied for each source gas independently. Additionally, more than 2 source gasses can be utilized by replicating the structure shown in FIG. 6 . Finally, FIG. 6 shows a completely flexible system which allows the injection of Source Gas A, excited Source Gas A, Source Gas B, and excited Source Gas B. Each can be supplied in varying amounts, where each flow rate is completely independent of the other rates. However, not all of the illustrated components are required. For example, assume that in a particular embodiment, only Source Gas A and both states of Source Gas B are required. In this case, it is possible to eliminate remote plasma source 300 and adjustable bypass valve 310 . Alternatively, if Source B is only required in its excited state, adjustable bypass valve 315 can be eliminated.
[0047] In some embodiments, two separate source gases allow for specialized components. For example, one source gas, bypass valve and remote plasma source can be dedicated to n-type dopants, while the second set of components is dedicated to p-type dopants to avoid potential cross-contamination and/or improve serviceability.
[0048] FIG. 7 illustrates another embodiment suitable for use with the ion source chamber 14 of FIG. 3 . In this embodiment, a common remote plasma source 330 is utilized, whereby flows from both source gasses can enter a single plasma source. This deliberate reaction of two source gasses (which can be elemental or compound gasses) may be used to produce a new compound gas, which is then injected into the ion source chamber 14 .
[0049] By doing so, desired molecules that are derived from the combination of multiple different gasses within the vacuum and environment of the source area and/or remote plasma area can be created. In other words, different gasses are fed into the vacuum environment or plasma chamber, so that they can react to create desired molecules. These molecules may be advantageous for specific purposes, such as implantation, deposition, or use in cleaning. The formation of molecules can be tailored by manipulating the plasma conditions via various control mechanisms, such as magnetic fields, flow, pressure, or electrical fields and/or properties, to create the desired effect. Thus, the formation of new or enhanced molecules could be realized and directly put to use in the process. One example of this would be to use two source gasses to introduce Hydride and Fluoride, which then combine to create HF, which is one of the more common molecules.
[0050] Adding multiple gasses and manipulating the conditions of the reaction within the chamber could allow the tailored formation of molecules that might otherwise be unstable, toxic, pyrophoric, dangerous, or have other characteristics that make them inconvenient to store and transport in bulk. Thus, in this embodiment, these molecules are only generated for point of use and for a desired effect.
[0051] Again, as described above, all of the components shown in FIG. 7 need not be present. For example, if Source Gas A and Source Gas B are only excited in a combined state, there is no need to include separate remote plasma sources 300 , 305 . Alternatively, if there is no need to inject the molecular form of one of the source gasses, the corresponding bypass valve can be eliminated.
[0052] The path length between the remote plasma sources 300 , 305 , 330 and the source chamber 14 is an important consideration. Should the path by too long, any metastable, excited or defragmented species would recombine prior to entering the ion source chamber 14 . Several techniques can be employed to minimize the recombination of species exiting the remote plasma source. In certain embodiments, the physical distance between the remote plasma source and the ion source chamber is minimized. In other embodiments, a localized magnetic confinement scheme is utilized so that the energized electrons and ions can be delivered to the source chamber. In yet another embodiment, an orifice located proximate the output of the remote plasma source is used to provide the necessary pressure difference for different operating conditions.
[0053] The gas injection system of FIGS. 5-7 is primarily intended to be used in conjunction with the existing ion source in an ion beam system. Thus, the gas injection system is used to alter the gas before it enters the ion source chamber 14 . Thus, the injected gas can be in different neutral conditions in terms of energy, configuration and fragmentation, since the ion source is used to then ionize the incoming gas.
[0054] FIG. 8 shows another embodiment for use with an ion beam application. In this embodiment, a second chamber, known as an antechamber 400 , is use to excite source gasses before they enter the ion source chamber 14 . Gas from one or more gas sources 40 enter the antechamber 400 . The antechamber 400 may have indirectly heated cathode 420 , with a filament 430 on one end and a repeller 460 on the opposite end. While FIG. 8 shows repeller 460 on the left end of the antechamber, and repeller 60 on the right end of the ion source, this is not a requirement. For example, the repeller 460 of the antechamber and the repeller 60 of the ion source can be on the same side of their respective chambers. The same source magnet 86 , used to confine electrons and ions within the source chamber 14 , may also be used to provide the same function in the antechamber 400 , if the antechamber and the ion source chamber are aligned, as shown in FIG. 8 .
[0055] As mentioned above, gas flows into the antechamber 400 , where it is treated to form excited neutrals as well as some ions. These excited molecules are then fed into the ion source chamber 14 via small openings or holes 450 on the top side of the antechamber. Note that in this embodiment, the top side of the antechamber also serves as the bottom of the ion source chamber 14 . Thus, excited, defragmented and/or heavy neutrals enter the ion source chamber 14 after being treated in the antechamber 400 . Also, since the electric fields are parallel in the ion source chamber 14 and the antechamber 400 , a common magnetic field, such as that created by source magnet 86 , can be used to confine the electrons, which are essential for ion source operation, in both chambers.
[0056] In certain embodiments, the holes 450 connecting the antechamber to the ion source chamber 14 are extremely small, such as 0.5 mm. In this way, the pressure in the antechamber 400 can be significantly different from that in the ion source chamber. As described above, by creating a remote plasma source, the formation of desired species can be optimized. For example, to produce heavier and metastable species, the antechamber is kept at a much higher pressure than the ion source chamber 14 , such as at about 100-500 mTorr. This enables heavier excited neutral species, such as P 2 and P 4 to be created. These molecules are then allowed to pass into the ion source chamber 14 , through the small holes connecting the chambers to be ionized.
[0057] Alternatively, high power and low pressure is used to create mono-atomic species. For example, boron tri-fluoride can be supplied to the antechamber 400 . The cathode 420 in the antechamber 400 serves to break the gas into a variety of ionic species and excited neutrals. These species are then fed into the ion source chamber where they are further broken down before being extracted as an ion beam. By pre-treating the gas, the concentration of specific charged ions, e.g. B + , is increased, resulting in an increased ion beam current for specific species.
[0058] While the above description utilizes a indirect heated cathode (IHC) ion source as the antechamber, other types of plasma sources may be used to create the antechamber. For example, traditional bernas-style ion sources, hollow-cathode style sources or filament based ion sources may also be used. In other embodiments, other types of plasma sources as described earlier can be used.
[0059] In other embodiments, ion implantation is performed using plasma immersion. Altered source gas injection can be used for plasma immersion implantation, as well. As shown in FIG. 4 , source gas enters the process chamber 102 via a conduit near the top of the volume. It is then converted to plasma using antennae 126 , 146 , and diffuses above the wafer. Baffles 170 serve to disperse the plasma relatively uniformly within the chamber 102 . For these implantation applications, controlling the plasma uniformity and the deposition pattern is critical to achieve acceptable implant uniformity. However, asymmetries from plasma generation and plasma confinement make it difficult to attain this goal for some applications, especially for low-energy applications. In addition, asymmetric pumping can add additional non-uniformity to the system.
[0060] In order to compensate for this uniformity, gas injection locations 510 can be added to the process chamber 102 . FIG. 9 shows the addition of several remote plasma sources 500 . These remote plasma sources can be of the types described above in reference to ion beam implantation system. Each remote plasma source receives a source gas, such as from a central reservoir. This gas is then altered to create plasma, ions, excited neutrals and metastable molecules. As described above, different pressures and power levels can be used to create different characteristics, depending on the specific species desired. These altered states can then be injected into the process chamber 102 . In FIG. 9 , 4 side injection locations are shown. However, this is only one embodiment; a greater or lesser number of injection locations can also be provided. Note that the preferred injection locations are along the side of the process chamber 102 , near the antenna 126 , as shown in FIG. 10 . This allows the effect from planar antenna 126 to excite the injected gas into a plasma, thereby helping to improve the uniformity over the workpiece. In certain embodiments, the rate of excited gas flow into each of the gas injection locations is the same, but only the power on each remote plasma source 500 is adjusted. However, if asymmetrical gas injection is desired, a mass flow controller (MFC) can be located between the source gas reservoir and each of the remote plasma sources 500 . Thus, the uniformity of the plasma and that of the neutrals within the chamber can be improved.
[0061] Although FIG. 9 shows the output of the remote plasma source being directly in communication with the injection locations, this is not a requirement of the present disclosure. For example, any of the configurations shown in FIGS. 5-7 can be used in conjunction with the system of FIG. 9 . In other words, a mix of source gas and altered molecules (as shown in FIG. 5 ) can be supplied to one or more injection locations. Similarly, a mixture of two gasses and their altered versions (as shown in FIG. 6 ) can also be supplied to one of more injection locations. Finally, the configuration shown in FIG. 7 can also be used to supply gasses to one or more injection locations. The components for these configurations can be replicated for each injection location. Alternatively, one such set of components may be shared for two or more injection locations.
[0062] In another embodiment, shown in FIG. 10 , the gas injection location 520 located on the top of the process chamber 102 is supplied with molecules from a remote plasma source 500 e . The use of a remote plasma source to pre-treat the gas can be used to compensate for fundamental asymmetries caused by the plasma source and/or confinement. A remote plasma source 500 e supplies gas to this injection location. This remote plasma source can be any suitable device, such as those described above.
[0063] In operation, gas source 104 supplies one of more gasses to one or more remote plasma sources 500 . These remote plasma sources excite the source gas as described above. The altered gas is then fed into the plasma chamber 102 via injection locations 510 . In some embodiments, different rate flows are required at each injection location, so separate MFCs are used for each injection location. In certain embodiments, the altered gas to be supplied to the injection locations is the same, and therefore only one remote plasma source is used to supply gas to all injection locations, where the flow rate at each location is controlled by an independent MFC. In other embodiments, the altered gas to be supplied to each injection location may differ. For example, it may be desirable to inject more heavy species near the outer edge of the plasma chamber 102 , as these species do not diffuse as readily as lighter ions. In this scenario, more than one remote plasma source 500 may be used.
[0064] While this disclosure describes specific embodiments disclosed above, those of ordinary skill in the art will recognize that many variations and modifications are possible.
[0065] Accordingly, the embodiments presented in this disclosure are intended to be illustrative and not limiting. Various embodiments can be envisioned without departing from the spirit of the disclosure. | An ion source includes an ion chamber housing defining an ion source chamber, the ion chamber housing having a side with a plurality of apertures. The ion source also includes an antechamber housing defining an antechamber. The antechamber housing shares the side with the plurality of apertures with the ion chamber housing. The antechamber housing has an opening to receive a gas from a gas source. The antechamber is configured to transform the gas into an altered state having excited neutrals that is provided through the plurality of apertures into the ion source chamber. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to an improved inductive type ignition system for use with internal combustion engines and the like.
Heretofore, various types of ignition systems have been devised for internal combustion engines. Listed below are a number of U.S. Patents known to the inventor which describe various types of prior art ignition systems.
______________________________________PATENT NO. INVENTOR ISSUE DATE______________________________________1,259,995 Kettering, et al. Mar. 19, 19183,056,066 Dozier, Jr. Sept. 25, 19623,280,809 Issler Oct. 25, 19663,550,573 Kowalski Dec. 29, 19703,677,253 Oishi, et al. July 18, 19723,704,397 Crouch, et al. Nov. 28, 1972______________________________________
Generally, prior art ignition systems have been unreliable for one or more of the following reasons:
A. Incapable when engine spark plugs are contaminated of generating ignition sparks of sufficient energy to ignite a fuel-air mixture;
B. Incapable of keeping engine spark plugs clean from carbon deposits and other contaminants;
C. Characterized by generating an ignition spark of too short duration to completely ignite non-homogenous fuel-air mixtures;
D. Subject to arcing across breaker points employed as timing means, thus have been plagued by unreliability caused by deterioration of the breaker points;
E. Have had only one source of ignition pulses so as to become inoperative whenever this one energy source becomes inoperative.
F. Failure of breaker point timing means to switch currents caused by circuit operation at current levels insufficient to burn away contaminants.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved induction type of ignition system for use with internal combustion engines and the like which is characterized by obviating the aforementioned disadvantages of prior art ignition circuits.
It is also an object of the present invention to provide an improved versatile ignition system adaptable for use with solid state, mechanical or other timing means and which may be powered by battery, a magnetic current source, or any other suitable power source.
It is additionally an object of the present invention to provide an improved ignition system suitable for application in automobiles, aircraft, motorcycles and the like.
It is further an object of the present invention to provide an improved ignition system as set forth characterized by being: reliable; capable of generating a composite ignition pulse having a fast rise time and relatively long duration; having redundant ignition pulse generating circuitry so that failure or disabling of a portion of the pulse generating circuitry does not necessarily disable the entire ignition circuit; and being operable to protect breaker point timing means from voltage and current signals which tend to cause arcing thereacross.
In accomplishing these and other objects, there is provided in accordance with the present invention an ignition system arranged to deliver pulses of energy to an internal combustion engine. The exemplary ignition system includes inductive-type ignition circuitry and a pulse generator. Inductive ignition pulses are generated in time correspondence with engine movements in response to timing signals generated by breaker points and the pulse generator is simultaneously triggered to generate a high amplitude pulse which combines with the inductive ignition pulse. Thereby a composite ignition pulse having a fast rise time and relatively long duration is produced. Circuitry, biased by the pulse generator output, is associated with the breaker points which protects the breaker points from voltage and current signals tending to cause arcing thereacross. Thereby, deterioration of the breaker points caused by arcing is essentially prevented. The system may be arranged so that the pulse generator or the induction type ignition circuitry may be selectively disabled.
Additional objects of the present invention reside in the specific construction of the exemplary embodiments of ignition circuits hereinafter described in connection with the several drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of an ignition system according to the present invention.
FIG. 2 is an alternate circuit arrangement which may be used in the ignition system of FIG. 1 to decouple the breaker points from the primary winding of the ignition coil.
FIG. 3 illustrates the circuitry of one suitable type of pulse generator connected in the ignition circuit of FIG. 1.
FIG. 4, 5 and 6 are each circuit diagrams of different embodiments of ignitions systems according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in more detail, there is shown in FIG. 1 an engine ignition system generally identified by the numeral 10. The ignition system 10 includes a D.C. voltage source in the form of a battery 11. The battery 11 may supply approximately 12 Volts D.C., as is common in vehicles of conveyance. Connected in series with the battery 11 to its positive pole is an ignition switch 12 for switching the ignition system on and off. Closure of ignition switch 12 supplies voltage to the circuit points 13 and 14. The circuit point 14 is connected in common with the negative pole of the battery 11 and is illustrated grounded.
The ignition circuit 10 includes a pulse generator 15; resistors 16 and 17; an ignition coil 18; a diode 19; a capacitor 20; and breaker points 21.
The pulse generator 15 has power input terminals 22, a trigger input terminal 23 and output terminals 24. The pulse generator 15 has its power input terminals 22 connected to the circuit points 13 and 14 to receive power from the battery 11 when the ignition switch 12 is closed.
Connected in the following order in series between the circuit points 13 and 14 are the resistor 16, the primary winding of the ignition coil 18, and the diode 19. The diode 19 is connected with its anode common with the primary winding of ignition coil 18 and its cathode common with the breaker points 21. Connected in parallel with breaker points 21 are the capacitor 20 and the resistor 17.
For purposes of discussion, the cirucit points 25, 26 and 27 are identified in the ignition circuit 10. The circuit point 25 is common with the point of connection between the resistor 16 and the primary winding of the ignition coil 18 and has the positive output terminal 24 of the pulse generator 15 connected thereto. The circuit point 26 is common with the point of connection between the primary winding of the ignition coil 18 and the anode of the diode 19. The negative output terminal 25 of the pulse generator 15 is connected to circuit point 26. Circuit point 27 is common with the connection between the cathode of the diode 19 and the breaker points 21. Electrical lead 28 connects the circuit point 27 in common with the trigger input terminal 23 of the pulse generator 15.
Connected across the secondary winding of the ignition coil 18 is a standard distributor and spark plugs represented by a single spark gap 29. Before describing the operation of the circuit 10, it is noted that the pulse generator 15 may be of any suitable type which is operable when triggered to generate a relatively short duration high amplitude output pulse across its output terminals 24. The output pulse may have a magnitude of 300 volts, may be in the form of a square wave, and has a duration which is shorter than the duration of the inductive ignition pulse generated by the induction ignition circuitry of the circuit 10, preferably only a small fraction of the duration thereof. For example, the pulse generator output pulse may have a duration of one hundred microseconds.
Upon closure of ignition switch 12, the ignition circuit 10 operates in the following described manner. The breaker points 21 function as timing means which control the generation of ignition pulses and are opened and closed in a conventional manner in time correspondence with the operation of the distributor and spark plugs represented by the gap 29. The distributor operates in a timed sequence to control the delivery of ignition pulses to the spark gaps 29 of the appropriate spark plugs in the conventional engine (not shown) being operated. Thereby, potentials developed on the ignition coil 18 are delivered or distributed in a timed sequence in a well known and conventional manner to the spark gaps 29 of the spark plugs associated with the cylinders or combustion chambers of the engine being operated. Thus, ignition sparks are generated to ignite the combustible fuel mixtures delivered to the engine cylinders.
With ignition switch 12 closed upon each closure of the breaker points 21, a current flows through the current path defined by the resistor 16, primary winding of the ignition coil 18, the diode 19 and the breaker points 21. This current flow is not sufficient to generate an ignition spark across the spark gap 29 and operates to store electromagnetic energy in the primary winding of the ignition coil 18. During this period of closure of the contacts 21, the circuit point 27 is grounded.
Upon opening of the breaker points 21, the ground is removed from the point 27 and the current flow therethrough is interrupted. Thus, the inductive energy stored in the primary winding of ignition coil 18 causes the capacitor 20 to charge. As a result, a trigger voltage is generated on circuit point 27 which is transmitted by lead 28 to the trigger input terminal 23 of the pulse generator 15. A high magnitude short duration pulse is consequently generated on the output terminals 24 of the pulse generator 15. This pulse is applied to the primary winding of ignition coil 18 and consequently a fast rise high amplitude ignition pulse is generated across the spark gap 29 due to the transformer action of the coil 18. Upon termination of the ouput pulse of the pulse generator 15, the operation of the induction ignition circuit provided by the resistor 16 and the ignition coil 18 takes over to generate a relatively long duration inductive ignition pulse across the spark gap 29. Thus, a composite ignition pulse is formed which has a fast rise time and long duration. It is noted that typically the pulse generator 15 is triggered into operation by a voltage signal less than 20 volts.
It is noted that when the pulse generator 15 is triggered into operation that a very high negative voltage such as -288 V appears on the circuit point 26 which reverse biases the diode 19. As a result, the diode 19 operates to decouple the breaker points 21 from the primary winding of ignition coil 18. Consequently, large voltage and current signals which would cause arcing, just after the points 21 have opened when their separation is relatively small, do not appear across the breaker points 21. It is further noted that the pulse generated by the pulse generator 15 in FIG. 1 is applied across the primary winding of ignition coil 18 in the same sense as the energy supplied by the battery 11 so that this pulse tends to increase the energy stored in the primary winding of the ignition coil 18. Upon termination of the pulse of the pulse generator 15, the current flow in the primary winding of the coil 18 reverses at which time diode 19 again becomes forward biased causing the charging of capacitor 20 to resume. It is noted that the mechanical gap of the breaker points 21 has increased during the time the diode 19 was reverse biased due to the mechanical driving arrangement operating the breaker points with the result that the points are sufficiently separated at the time the diode 19 again becomes forward biased to prevent any arcing subsequent to the termination of the pulse generator output pulse. The resistor 17 connected in parallel with the capacitor 20 functions to drain to ground any charge accumulated thereon during the generation of the trigger pulse and inductive pulse on circuit point 27.
It is noted that in the circuit of FIG. 1, as well as the other circuits hereinafter described, that the battery 11 and resistor 16 forming the battery power source could be replaced by a magnetic energy source such as a magneto. Also there is no requirement that these ignition systems be used with a conventional distributor. Some applications in which these ignition systems may be used do not include such a distributor, such as motorcycles, gas burner ignitors and jet engines.
FIG. 2 represents an alternate circuit arrangement for decoupling the breaker points 21 from the ignition coil 18 during the generation of ignition pulses. The decoupling circuit arrangement shown in FIG. 2 is generally identified by the numberal 35 and is formed by a silicon controlled rectifier (SCR) 36, a voltage divider made up of resistors 37-39 and an on-off switch 40. For purposes of discussion, the circuit points 41, 42 and 43 are designated in the decoupler circuit arrangement 35.
In order to use the decoupler circuit 35 in the ignition circuit 10, the diode 19 is first removed. The silicon control rectifier is then connected in series between the primary winding of ignition coil 18 and the breaker points 21 by commonly connecting circuit points 42, 26 and 41, 27. Voltage is supplied to the voltage divider defined by resistors 37-39 by commonly connecting circuit points 13 and 43. The on-off switch 40 which defines the disabling switch is connected between ground and a selective point on the voltage divider, illustrated as the point of interconnection of the resistors 37 and 38. With the decoupler circuit 35 connected in ignition circuit 10 instead of the diode 19, the ignition circuit 10 functions in the same manner as above described with the on-off switch 40 open, with the added advantage that the charging of capacitor 20 does not resume upon termination of the output pulse of the pulse generator 15 since the SCR 19 is turned off during this pulse and remains nonconductive during the generation of the inductive ignition pulse. By selectively closing the switch 40, the induction ignition circuitry of the ignition circuit 10 may be selectively disabled. Closure of the switch 40 grounds the point of interconnection between the resistors 37, 38 with the result that the SCR 36 does not conduct when the points 21 close. Consequently, inductive energy is not stored in the primary winding of ignition coil 18 during the time period which the points 21 are closed.
FIG. 3 illustrates an ignition system similar to that above-described and shown in connection with FIG. 1. The circuit shown in FIG. 3 is identified generally by the numeral 110, and its components which correspond to components above described in connection with FIG. 1 are identified by a 100 numeral having the same last two digits used in FIG. 1. One configuration of suitable pulse generator is shown in the ignition circuit 110 and this pulse generator includes a low impedance DC-AC-DC voltage converter 39; an L-C resonance circuit made up of capacitor 40 and inductor 41; trigger switch means in the form of an SCR 42; and trigger signal generating means made up of resistors 43-44, diodes 45-46, a capacitor 47 and a pulse transformer 48.
The ignition circuit 110 operates in a manner similar to that above-described in connection with FIG. 1. The pulse generator therein generates a fast rise short duration ignition pulse in the following manner. The voltage converter 39 may be of any conventional type, such as an oscillator or pulse type. The converter 40 converts the 12 volt DC signal received from battery 111 to a high voltage DC signal, such as a 300 volt signal, on its output terminals 124. Upon opening of the breaker points 121, the voltage on the cathode of the diode 46 increases to reverse bias this diode. As a result, current flows in the circuit path defined by the resistor 43, diode 45, capacitor 47 and the primary winding of the pulse transformer 48 to charge the capacitor 47. As a consequence, the current through the primary winding of the transformer 48 generates a trigger pulse in its secondary winding of this coil which triggers the SCR 42 into conduction. Triggering of the SCR switch 42 into conduction connects the output terminals of the converter 39 across the primary of the ignition coil 118 to apply the large voltage on these terminals thereacross. As a consequence, a fast rise ignition pulse in generated in the L-C circuit made up of capacitor 40 and inductor 41 is triggered into oscillation
The duration of the ignition pulse generated by this pulse generator is equal to the time period the SCR 42 conducts which in turn is determined by the resonant frequency of the L-C circuit 40-41. The L-C circuit 41 functions solely as a timing means to control the period of conduction of the SCR 42 since after a half cycle of resonance the L-C circuit 40, 41 reverse biases the SCR 42 into a nonconductive state. Thus, the duration of the pulse generated by the pulse generator in this circuit may be controlled by appropriately selecting the values of capacitance and inductance of the components 40 and 41.
The pulse generator shown in FIG. 3 is a variation of a thyristor converter circuit. It is noted, however, that a blocking oscillator circuit or other type of high power ouput low impedance pulse generator circuit could be also employed.
When the breaker points 121 close, inductive energy is restored in the primary winding of the ignition coil 118. Simultaneously, the capacitor 47 is discharged through the current path defined by the resistor 44, diodes 46 and 119, and the breaker points 121. It is noted that the time delay associated with the discharge of the capacitor 47 and the increase in current flow through the primary winding of the ignition coil 118 ensures that arcing will not occur across the breaker points 121 due to momentary bounce of the breaker points at the time of their closure. It is noted that the pulse generator shown in FIG. 3 may be selectively disabled by opening the on-off switch 49.
FIG. 4 discloses an alternate embodiment of ignition circuit according to the present invention generally identified by the numeral 210. Components of the ignition circuit 210 corresponding to components in the ignition circuits hereinbefore described are identified by a two hundred number with its last two digits corresponding to the two digit number hereinbefore used to indentify the same component.
In operation of the ignition circuit 210, upon opening of the breaker points 221, the pulse generator 215 provides a fast rise short duration ignition pulse which is delivered to the primary winding of the ignition coil 218 through diode 60. It is noted that the pulse generated by the pulse generator 215 causes current to flow through the primary winding of the coil 218 in the same direction as the inductive ignition pulse induced therein. The diode 60 functions to prevent arcing across the breaker points 221 since it is forward biased by the pulse output of the pulse generator 215. Diode 60 becomes reverse biased during the generation of the inductive portion of the composite ignition pulse delivered to the spark gap 229. However, the increase of the mechanical gap of the breaker points prevents arcing theracross. It is noted that the trigger pulse delivered to trigger input terminal 223 is generated upon the opening of the breaker points 221 since at the instant the diode 60 is reverse biased, thus the capacitor 220 commences to charge. Further, it is noted that a decoupler 61 is shown connected between the resistor 216 and the primary winding of ignition coil 218. Decoupler 61 may be formed by a resistor or inductor of suitable value. The decoupler 61 operates to effectively decouple the ignition coil 218 from the battery 211 during the generation of ignition pulses. This action assures that the pulse generator circuit is not shunted by the battery and that sufficient current flows in the primary winding of the coil 218.
The ignition circuit 310 shown in FIG. 5 is numbered in a manner similar to that used for the ignition circuit 210 and uses numbers in the three hundred series. In the ignition circuit 310 the pulse generator 315 is inductively coupled to the primary winding of the ignition coil 318. This inductive coupling is illustrated being accomplished by connecting the secondary winding of pulse transformer 70 between the resistor 316 and the primary winding of the ignition coil 318. The primary winding of the transformer 70 is connected across the output terminals of the pulse generator 315. The transformer 70 should have a ferrite core or be otherwise constructed for high frequency signals in order to preserve the fast rise time of the pulse generated by the pulse generator 315.
The embodiment of ignition system shown in FIG. 6 is generally indentified by the numeral 410 and has its components which correspond to components hereinabove described indentified by a four hundred numeral with the last two digits corresponding to the two digit number used hereinbefore to identify the same component. In the embodiment illustrated in FIG. 6, the pulse transformer 470 is illustrated with its secondary winding connected in series with the secondary winding of ignition coil 418. it is noted that the polarity of the output terminals of the pulse generator 415 are reversed from that shown in FIG. 5 and that the windings of the transformer 470 are connected with their polarities out of phase rather than in phase as shown in FIG. 5. In operation of the ignition circuit 410, the fast rise short duration pulse output of the pulse generator 415 is delivered through the secondary winding of the ignition coil 218 and the diode 460 in the circuitry functions as before described in connection with FIG. 4 to prevent arching at the breaker points 421.
Although I have herein shown and described my invention in what I have conceived to be the most practical and preferred embodiments, it is recognized that departures may be made therefrom within the scope of my invention. | An ignition circuit arranged to deliver pulses of energy to an internal combustion engine includes inductive-type ignition circuitry and a pulse generator. Inductive ignition pulses are generated in time correspondence with engine movements in response to timing signals generated by breaker points and the pulse generator is simultaneously triggered to generate a high amplitude pulse which combines with the inductive ignition pulse to produce a composite ignition pulse having a fast-rise time and relatively long duration. Circuitry, biased by the pulse generator output, is associated with the breaker points which effectively isolates the breaker points electrically from voltage and current signals which tend to cause arcing thereacross. Thereby, deterioration of the breaker points caused by arcing is prevented. The circuit may be arranged so that the pulse generator or the inductive-type ignition circuitry may be selectively disabled. | 5 |
RELATED PATENT APPLICATIONS
[0001] This application is a Continuation in Part, based upon U.S. Utility patent application Ser. No. 11/998,612 filed Nov. 30, 2007 and presently pending. Applicant claims the priority of the above referenced parent patent application.
RULE 1.78 (F) (1) DISCLOSURE
[0002] The Applicant has not submitted a related pending or patented non-provisional application within two months of the filing date of this present application. The invention is made by a single inventor, so there are no other inventors to be disclosed. This application is not under assignment to any other person or entity at this time.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to Poly(2-Octadecyl Butanedioic acid) and the salts and esters thereof, and more particularly pertains to the uses of Poly(2-Octadecyl Butanedioate) and Poly(2-Octadecyl Butanedioic Acid) as polycarbonate organic polymers. This application pertains to the uses of the herein described compound in ways heretofore not disclosed or taught.
[0005] 2. Description of the Prior Art
[0006] Organic polymers (plastics) are amorphous solids that characteristically become brittle on cooling and soft on heating. The temperature at which this structural transition takes place is known as the glass transition temperature. More specifically, the IUPAC Compendium of Chemical Terminology defines the glass transition temperature as a pseudo second order phase transition in which a super-cooled melt yields a glassy structure with properties similar to those of crystalline materials upon cooling (The IUPAC Compendium of Chemical Terminology, 66, 83 (1997)). Above this temperature, these materials become soft and capable of deformation without fracture due to the weakening of the secondary, non-covalent bonds between the polymer chains. This characteristic enhances the usefulness of a subset of plastic materials known as thermoplastics. Those schooled in the art know that the transition temperature for a polymer can be influenced by the addition of plasticizers, other polymeric substances, the cooling-ratio, and its molecular weight distribution. The mean glass transition temperature for polycarbonate is reported to be 145° C. (Engineered Materials Handbook-Desk edition (1995) ASM International, ISBN 0871702835. p. 369).
[0007] Many polymers, including polycarbonates, can be used for several molding processes including, injection, extrusion, and extrusion/injection blow molding. In injection molding, these thermoplastics are heated and then pressed into a mold to form different shape plastics. In extrusion molding, the polymer is melted into a liquid and forced through a die forming a long continuous piece of plastic with the shape of the die. When the extruded material cools, it forms a solid with the desired shape. Blow molding is a process by which hollow plastic parts are formed either by injection or extrusion. Those schooled in the art know that the optimum polymer melt temperature, die and mold temperature, and annealing conditions must be empirically determined for each plastic material and mold/die configuration. Polycarbonate resins are tough thermoplastics with very high visual clarity and exceptionally high levels of impact strength and ductility. Polycarbonate resins, or “Polycarbonates” also possess inherent fire resistance, relatively good resistance to UV light, good resistance to aqueous solutions of organic and inorganic acids and good resistance salts and oxidizing agents, but offer limited resistance to organic solvents. Typical properties of polycarbonates include exceptional machine-ability, low water absorption, good impact resistance, non-toxic formulations, good thermal properties, superior dimensional stability, heat resistance, and transparency with thicknesses up to 2″.
[0008] Currently, major markets for polycarbonate resins include the electrical/electronic sectors, such as computer and business equipment and optical disks, sheet and glazing products, and the automotive industry. Other products include safety helmets, safety shields, housing components, household appliances, sporting goods, and aircraft and missile components. Specific product applications include doors, equipment enclosures, greenhouses, high voltage switches, high temperature windows, instrument gauge covers, automotive instrument panels, light bezels, pumps and valves, connectors, gears, internal mechanical parts, relays, rollers, lenses, sight glasses, light shields, machine guards, patio roofs, photo lens covers, replacement for metal components of safety equipment, guards, helmets, shields, signs, solar rods, thermal insulation, thermometer housings, and window glazing. Polycarbonates have also received approval from the U.S. Food and Drug Administration for use in medical instruments, medical implants, and tubing.
[0009] Polycarbonate, while broadly used, is limited in specific instances. As previously mentioned, polycarbonate typically shows good resistance (at room temperature) to water, dilute organic and inorganic acids, neutral and acid salts, and aliphatic and cyclic hydrocarbons. It does not resist attacks from alkalines, amines, ketones, esters, and aromatic hydrocarbons.
[0010] Several US retailers have begun to remove polycarbonate food and beverage containers from their shelves due to concerns that small amounts of bisphenol-A (BPA), a component of polycarbonates, can be released from the polymer over time. The US government's National Toxicology Program has indicated that there is limited evidence that low doses of BPA can cause health problems and reproductive defects in humans.
[0011] Polycarbonates can generally be classified into two major categories: aromatic and aliphatic. Aromatic polycarbonates are prepared by the reaction of an aromatic diol with phosgene gas (COCl 2 ). (See FIG. 3; Howdeshell, K. L., et. al. “Bisphenol A is Released from Used Polycarbonate Animal Cages into Water at Room Temperature.” Environ. Health Perspect. 111(9):1180-1187 (2003). Bisphenol-A is typically used as the aromatic diol and has been the subject of health concerns associated with its release from the polymer. It is currently not known if the source of bisphenol-A is through leaching of the monomer due to incomplete polymerization or hydrolysis of the polymer induced by heating and/or contact with acidic or basic materials.
[0012] Aliphatic polycarbonates are frequently used as bioresorbable materials for biomedical applications, such as medical implants and drug delivery carriers (see; Raigorodskii, I. M., et. al. Soedin., Ser. A. 37(3):445 (1995); Acemoglu, M. PCT Int. Appl., WO 9320126 (1993); Katz, A. R., et. al., Surg. Gynecol. Obstet. 161:312 (1985); Rodeheaver G. T., et. al., Am. J. Surg. 154:544 (1987) Kawaguchi, T., et. al., Chem. Pharm. Bull. 31, 1400:4157 (1983); Kojima, T., et. al., Chem. Pharm. Bull. 32:2795 (1984). These materials generally show good biocompatibility, low toxicity, and biodegradability (Zhu, K. J., et. al., Macromolecules. 24:1736 (1991)). Poly alkylene carbonates have been synthesized by the reaction of aliphatic diols with phosgene (Schnell, H. Chemistry and Physics of Polycarbonates, Wiley, N.Y., 1964, p 9), the copolymerization of epoxides with carbon dioxide in the presence of organometallic catalysts (Inoue, S., Koinuma, H., Tsuruta, T. Makromol. Chem. 120:210 (1969)), the ring-opening polymerization of cyclic carbonate monomers (Hocker, H. Macromol. Rep., A31 (Suppls. 6&7), 685 (1994)), carbonate interchange reactions between aliphatic diols and dialkyl carbonates (Pokharkar, V., Sivaram, S. Polymer, 36:4851 (1995)), and the direct condensation of diols with CO 2 or alkali metal carbonates (see; Soga, K. et. al., Makromol. Chem. 178:2747 (1977); Rokicki, G., et. al., J. Polym. Sci., Polym. Chem. Ed., 20:967 (1982); Rokicki, G., et. al., Polym. J. 14:839 (1982); Chen, X., et. al., Macromolecules, 30:3470-3476 (1997)).
SUMMARY OF THE INVENTION
[0013] Described herein is a novel polycarbonate, poly(2-octadecyl butanedioate), and it related derivates, consisting of a carbon containing backbone containing carboxylate groups directly attached to the backbone. This structure is in stark contrast to existing polycarbonates as all existing polycarbonates are characterized by ester linkages between the monomeric units. Thus, the “carbonate” moiety of both aromatic and aliphatic polycarbonates exist in the linear chain or backbone of the polymer. This carbonate linkage has been removed from the backbone of poly(2-octadecyl butanedioate).
[0014] In summary, the characteristics of this polymer are not predicted by the literature and, as such, the use of the polymer to be used as a polycarbonate organic polymer in the manner described, is unexpected, and constitutes a new and unexpected use for the polymer. Contrary to the literature that teaches that this polymer should not work in the manner shown empirically, it has been demonstrated that the polymer, as herein described, functions in a new, unanticipated manner, and therefore comprises a new use for Polycarbonate.
[0015] While these compounds disclosed in the prior art fulfill their respective, particular objectives and requirements, the prior art does not describe the new and useful improvements in a polycarbonate organic polymer, and the method of use of Poly(2-Octadecyl-Butanedioic Acid) and the salts and esters thereof that allows the use of these compounds as a polycarbonate resin. In this respect, the polycarbonate organic polymer, and method of use of Poly(2-Octadecyl-Butanedioic Acid) and the salts and esters thereof according to the present invention substantially departs from the conventional concepts and compounds described in the prior art, and in doing so provides compounds primarily developed for the purpose of providing these compounds as a polycarbonate resin. Therefore, it can be appreciated that there exists a continuing need for new and improved polycarbonate organic polymers, and method of use of Poly(2-Octadecyl-Butanedioic Acid) and the salts and esters thereof which can be used as a polycarbonate resin. In this regard, the present invention substantially fulfills this need.
[0016] Poly(2-octadecyl-butanedioic acid) and the salts and esters thereof, prepared from polyanhydride PA-18 or other preparative means as would be evident to those skilled in the art, possess novel polycarbonate resin characteristics. Essential characteristics/benefits are summarized below.
[0017] The novel polycarbonates, poly(2-octadecyl butanedioate) and it related derivates, possess unique properties. In addition to the properties of existing polycarbonates, these compounds have an unexpected increased resistance to organic solvents, an unexpected increased impact strength, and an unexpected increased optical clarity. Further, these polycarbonates are biodegradable, can be extruded into strands, and injection molded.
[0018] The polymers, herein described, have several potential uses that are beneficial. These include all existing applications of polycarbonates, waterproof and chemically resistant fabric (exterior fabric, hospital sheets, chemical safety clothing), chemically resistant furniture, fixtures, and containers, and BPA-free food and beverage containers.
[0019] In view of the foregoing disadvantages inherent in the known types of polycarbonate resins now present in the prior art, the present invention provides improved polycarbonate organic polymers, and method and use of Poly(2-Octadecyl-Butanedioic Acid) and the salts and esters thereof. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved polycarbonate organic polymer and method and use of Poly(2-Octadecyl-Butanedioic Acid) and the salts and esters thereof which have all the advantages of the prior art and none of the disadvantages.
[0020] To attain this, the present invention essentially comprises a polycarbonate resin comprising a polymer backbone. The backbone is a water insoluble, hydrophobic, aliphatic polymer structure. There are two sodium carboxylate groups or carboxylic acid groups per repeating unit that are directly bound to the polymer backbone. There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims attached.
[0021] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of formulation and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced an carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of descriptions and should not be regarded as limiting.
[0022] As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other formulations, and methods for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent formulations insofar as they do not depart from the spirit and scope of the present invention. It is therefore an object of the present invention to provide new and improved polycarbonate organic polymers, and method of use of Poly(2-Octadecyl-Butanedioic Acid) and the salts and esters thereof which have all of the advantages of the prior art polycarbonate resins and none of the disadvantages.
[0023] It is another object of the present invention to provide new and improved polycarbonate organic polymers, and method of use of Poly(2-Octadecyl-Butanedioic Acid) and the salts and esters thereof which may be easily and efficiently manufactured and marketed.
[0024] It is a further object of the present invention to provide new and improved polycarbonate organic polymers, and method of use of Poly(2-Octadecyl-Butanedioic Acid) and the salts and esters thereof which are easily reproduced.
[0025] An even further object of the present invention is to provide new and improved polycarbonate organic polymers,and method of use of Poly(2-Octadecyl-Butanedioic Acid) and the salts and esters thereof which is susceptible of a low cost of manufacture with regard to both materials and labor, and which is accordingly is then susceptible of low prices of sale to the consuming public, thereby making such improved polycarbonate organic polymers, and method of use of Poly(2-Octadecyl-Butanedioic Acid) and the salts and esters thereof economically available to the buying public.
[0026] Even still another object of the present invention is to provide improved polycarbonate organic polymers, and method of use of Poly(2-Octadecyl-Butanedioic Acid) and the salts and esters thereof for the use of a polycarbonate resin for the making of injection and/or extrusion molded plastics.
[0027] Lastly, it is an object of the present invention to provide new and improved polycarbonate organic polymers, and method of use of Poly(2-Octadecyl-Butanedioic Acid) and the salts and esters thereof which can be extruded into strands.
[0028] These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operational advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
FIGURES
[0029] FIG. 1 is a drawing of the compound Poly(2-Octadecyl-Butanedioic Acid), showing the pertinent structure and formula. FIG. 1 is the first configuration of the compound and illustrates two potential carboxylic acid environments. In this figure, R1, R3, and R5 represent either substituted or unsubstituted alkyl, alkenyl, alkynyl, and aryl groups. The labile hydrogen atoms of the carboxylic acid groups can be replaced with a mono, di, tri, tetra, or other valent cation to form the corresponding carboxylate salts. Additionally, these carboxylic acid groups can be esterified to form the substituted or unsubstituted alkyl, alkenyl, alkynyl and aryl ester derivatives.
[0030] FIG. 2 shows an alternate synthesis of 2-Octadecyl-Butanedioic Acid Analogs. FIG. 2 is the second configuration of the compound. In this figure, R′, R″, and R′″ represent either substituted or unsubstituted alkyl, alkenyl, alkynyl, and aryl groups. Additionally, the R group of the carboxylic acid represents hydrogen (to form the corresponding carboxylic acid), a mono, di, tri, tetra, or other valent cation (to form the corresponding carboxylate salts), or substituted or unsubstituted alkyl, alkenyl, alkynyl, and aryl groups (to form the corresponding esters).
[0031] FIG. 3 is an aromatic Polycarbonate synthesized from Bisphenol-A (BPA) and Phosgene, showing the structure of BPA and partial structure of the copolymers polycarbonate and polysulfone shown by monomeric chain units (n) within brackets. Both the rigidity of the aromatic rings and the inherent flexibility of the C—O, C—S, and C—C single bonds are depicted. Polycarbonate is joined by ester linkages (O—C═O—O) whereas Polysulfone has ether linkages (C—O). For images of three-dimensional structures, refer to Edge et all (1994).
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] Use of Poly(2-Octadecyl Butanedioate) and its corresponding acid and derivatives, as Polycarbonate resins, is herein described. As previously described, polycarbonate resins are generally tough thermoplastics with very high visual clarity and exceptionally high levels of impact strength and ductility. They also possess inherent fire resistance, relatively good resistance to UV light, good resistance to aqueous solutions of organic and inorganic acids and good resistance salts and oxidizing agents, but offer limited resistance to organic solvents. Typical properties include exceptional machinability, low water absorption, good impact resistance, non-toxic formulations, good thermal properties, superior dimensional stability, heat resistance, and transparency with thicknesses up to 2 inches.
[0033] Polycarbonate, while broadly used, is limited in specific instances and applications. As previously mentioned, polycarbonate typically shows good resistance (at room temperature) to water, dilute organic and inorganic acids, neutral and acid salts, and aliphatic and cyclic hydrocarbons. Polycarbonate does not resist attacks from alkalines, amines, ketones, esters, and aromatic hydrocarbons.
[0034] The polymer as herein described does not exhibit these limitations and may be used to make a strand, which can then be woven into a fabric or spun to make a yarn. The fabric may be used to make articles of clothing, or other such objects, such as bedsheets. The polymer may also be formed as a solid sheet, or solid object. Such sheets may be molded to form containers, or may be used as sheeting, such as in window replacement or protective shielding. Sheets of polymer may be used to form surfaces, such as protective surfaces for furniture. The forms in which the polycarbonate herein described may be used, such as strands, sheets, moldable sheets, containers, and solid objects, are collectively referred to as “constructs”. The use of the word “constructs” therefore refers to such configurations of the polymer.
[0035] Described herein is a novel polycarbonate, poly(2-octadecyl-butanedioate), and it related derivates, consisting of a carbon containing backbone containing carboxylate groups directly attached to the backbone. This structure is in stark contrast to existing polycarbonates, as all existing polycarbonates are characterized by ester linkages between the monomeric units. Thus, the “carbonate” moiety of both aromatic and aliphatic polycarbonates exist in the linear chain, or “backbone”, of the polymer. This carbonate linkage has been removed from the backbone of poly(2-octadecyl butanedioate).
[0036] The novel polycarbonates, poly(2-octadecyl butane-dioate) and its related derivates, possess unique properties. In addition to the properties of existing polycarbonates, these compounds have increased resistance to organic solvents, increased impact strength, and increased optical clarity. These enhanced characteristics are unexpected. Further, these polycarbonates can be extruded into strands and injection molded. As such, the herein described Polycarbonate presents the user with the unexpected properties, and unexpected results.
[0037] Potential applications include, but are not limited to, all existing applications of polycarbonates, the production of waterproof and chemically resistant fabric (exterior fabric, hospital sheets, chemical safety clothing), chemically resistant furniture, fixtures, and containers, and BPA-free food and beverage containers.
[0038] With reference now to the drawings, and in particular to FIG. 2 thereof, the preferred embodiment of the new and improved polycarbonate organic polymer, and method of use of Poly(2-Octadecyl-Butanedioate, sodium) embodying the principles and concepts of the present invention will be described. Simplistically stated, the polymer herein described comprises a plurality of reactive groups, being carboxylates or carboxylic acid groups. The reactive group is directly bonded to the carbon backbone. In the preferred embodiment a reactive group is bound-to a separate carbon atom. In other words, where there are two reactive groups, each reactive group is coupled to one of two carbon atoms, with (in the case of more than one reactive groups) the reactive groups not being coupled to the same carbon atom. The initial, or primary component, for the synthesis, is a commonly available, previously described component. The primary component may be prepared as follows:
[0039] 1. The polycarboxylate is produced from the corresponding polyanhydride. The polyanhydride is produced by a process that is described and disclosed in U.S. Pat. No. 3,560,456, issued to S. M. Hazen and W. J. Heilman, entitled “Process of forming copolymers of maleic anhydride and an aliphatic olefin having from 16 to 18 carbon atoms.” The description of the process as described in the '456 patent is incorporated herein by reference.
[0040] 2. The polycarboxylate is produced from the polyanhydride by the following procedure: 10 grams of the polyanhydride PA-18 are dissolved in 200 ml of 4M NaOH and stirred at 85 degrees Centigrade for 2 hours. The reaction mixture is cooled, the pH adjusted to 6 to 6.5, and vacuum filtered. The solid polymer is washed with cold analytical grade methanol and dried under vacuum.
[0041] 3. There are other methods to produce the polycarboxylate. One method is to produce the polyester. Subsequent hydrolysis of the polyester would produce the polycarboxylate. These reaction schemes would be obvious to someone skilled in the art of organic synthesis or polymer synthesis.
[0042] In the reaction sequence shown in FIG. 2 , R in both the reactants and products may be a substituted or unsubstituted alkyl, alkenyl, alkynyl, or aryl group, such as methyl or ethyl, making both the reactants and products esters. The product above, in other embodiments, may be further modified by hydrolysis of the ester in either basic or acidic media to produce the polycarboxylate or polycarboxylic acid, respectively.
[0043] In the case of hydrolysis in a basic media, if sodium hydroxide is used, the sodium salt of the polycarboxylate ion is formed (designated as R═Na + ). Likewise, if potassium hydroxide is used, the potassium salt of the polycarboxylate ion results (designated R═K + ). If one carries out an acid catalyzed ester hydrolysis (acid is used in the second reaction above), then the polycarboxylic acid is produced (designated R═H).
[0044] In these polymers, the carboxylates or carboxylic acid groups are separated by 0 to 8 carbon atoms. In other embodiments, the number of carbon atoms between the carboxylates or carboxylic acid groups may be up to 20 carbon atoms.
[0045] In describing and claiming the uses, reference is made to a carboxylate group, or to a carboxylic acid group. In describing the carbon atoms which are chemically bound to such groups (carboxylic acid, or carboxylate) the carbon is referred to as the “bound-to” carbon atom. Reactive groups includes groups other than carboxylate groups or carboxylic acid groups. The term “reactive groups” is intended to include any reactive group which may attach to a carbon atom. Where reference is made to a carboxylate group, or carboxylic acid group, as being “bound-to” a carbon atom, the language is limited to only carboxylate groups and carboxylic acid groups.
[0046] With respect to the above description then, it is to be realized that one skilled in the art would be cognizant of equivalent relationships to those illustrated in the drawings and described in the specification, and such equivalents are intended to be encompassed by the present invention.
[0047] Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact formulation and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | A polymer comprising a polymer backbone. The polymer backbone has a plurality of carbon atoms. There are two lipophobic carboxylate groups or carboxylic acid groups per repeating unit being coupled to separate carbon atoms of the backbone. | 3 |
CROSS REFERENCE TO RELATED APPLICATION
This patent application is related to a patent application filed concurrently herewith and assigned to the assignee of the instant invention, such patent application being entitled "Sewing Machine" by Sidney (NMI) Bass and Hubert Allen Rich, Ser. No. 761,381, filed Jan. 21, 1977.
BACKGROUND OF THE INVENTION
The background of the invention will be discussed in two parts:
1. Field of the Invention
This invention relates to sewing machines and more particularly to a cartridge for sewing machines.
2. Description of the Prior Art
Sewing machines utilizing cartridges or cassettes for carrying a spool of thread, or a spool of thread and a needle are shown in U.S. Pat. Nos. 3,385,247 and 3,749,039, both patents being described in the above-referenced co-pending application.
Devices for feeding strips of ribbon or the like have been devised as attachments to or modifications of existing sewing machines, such devices being shown in U.S. Pat. Nos. 1,731,074 issued Oct. 8, 1929 to Maier; 1,748,770 issued Feb. 5, 1930 to Horning; 1,849,797 issued Mar. 15, 1932 to Hake; 3,154,033 issued Oct. 27, 1964 to Roy; 2,961,186 issued Nov. 22, 1960 to Sayles; and 3,847,099 issued Nov. 12, 1974 Braun. The prior art known to applicant is listed by way of illustration and not of limitation, in a separate communication to the Patent Office.
It is an object of the present invention to provide a cartridge for a sewing machine.
It is another object of this invention to provide a cartridge having means integral therewith for dispensing ribbon-like material.
SUMMARY OF THE INVENTION
The foregoing and other objects of the invention are accomplished by providing a sewing machine having a cartridge mounted in the side of the head, the cartridge containing therein a spool of thread and a pre-threaded needle on a needle carrier adapted for reciprocation within the cartridge with the needle passing out of the cartridge through an aperture in the bottom thereof. The cartridge is so dimensioned that the spacing between the aperture and the bed of the machine is in close relation generally to preclude entry therebetween of fingers. The cartridge is provided with a recess for rotatably receiving a spool carrying a strip of ribbon-like material, the strip passing through a channel formed in an edge of the cartridge in proximity to the aperture, the spool being positioned on the cartridge in a direction of rotation so that the tendency of the strip to resist unwinding automatically directs the strip inwardly toward the aperture.
Other objects, features and advantages of the invention will become apparent upon a reading of the specification when taken in conjunction with the drawings in which like referenced characters refer to like elements in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a sewing machine having a cartridge according to the invention;
FIG. 2 is an end view of the sewing machine of FIG. 1, partially in cross section and partially broken away to show the cartridge details; and
FIG. 3 is a rear view of the cartridge used in the sewing machine of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and particularly to FIG. 1, there is shown a sewing machine which includes a main platform or work-supporting bed 10 having an integral upwardly extending standard 14, a bracket arm extending generally parallel to the bed 10 from the standard 14, the other end of which terminates in a vertically depending head 18. Generally the sewing machine is electrically operated by means of a switch 20 which connects batteries therein to a motor for operation of the machine. The structural details pertaining to the construction and operation of the sewing machine of FIG. 1 are fully shown and described in the above referenced co-pending application entitled "Sewing Machine".
In any event, the head 18 is provided with a recessed portion 22 in the side thereof, the recess 22 having a planar vertical surface with an outwardly extending ledge portion 24, the ledge 24 being adapted to engage the lower edge of a cartridge member 26 with the rear surface of cartridge 26 abutting against recess 22. The cartridge 26 can be retained within the recess 22 by any conventional means such as detents or the like. The cartridge 26 contains therein a spool of thread 28 (see also FIG. 2) which is rotatably received on a shaft projection 30 integrally formed with the front transparent cover 25 of cartridge 26. The thread 32 from spool 28 is suitably wound about a tensioning device 34 formed within cartridge 26 and more fully described in the above referenced co-pending application, the thread 32 then being passed through the eye of a needle 36 secured to a needle carrier 38 mounted for reciprocating movement on a vertical line within cartridge 26 against the force of a bias spring 40. In side elevation, as can be seen in FIG. 2, the cartridge 26 has a right angled edge generally fitting within a mating portion of the recessed portion 22 with the edge of cover 25 adjacent the operator position diverging downwardly toward the lower portion of cartridge 26 which is provided with a neck portion 42 through which extends an aperture 44 through which the needle 36 passes during its reciprocation. The neck portion 42 extends through an aperture formed within the ledge 24 integral with the side of the head 18, the lower surface of ledge 24 being generally parallel to bed 10 with a space therebetween defining a throat 46 through which the fabric to be sewn is passed. A suitable material advance foot 48 is provided for incrementing the fabric during the stitching operation.
Referring to FIGS. 2 and 3 the details pertaining to the construction of the cartridge 26 will be discussed. As previously mentioned the cartridge 26 has a transparent cover 25 engaging a generally planar rear surface or back wall 50. The back wall 50 is provided with an enlarged aperture 52 through which a crank pin extends from within the machine to actuate the needle carrier 38 by means of the crank pin engaging a crank pin groove 54 formed in the rear surface of the needle carrier 38 and accessible through aperture 52. The needle carrier 38 is vertically reciprocated with the upper portion of needle carrier 38 fitting between opposing parallel sidewalls 56 and the lower portion of needle carrier 38 sliding between opposing guide ribs 58. The needle 36 is of conventional configuration and is press fit into a suitably formed aperture within the bottom edge of needle carrier 38. The needle 36 is provided with an eye adjacent the point thereof through which the thread 32 passes out through the aperture 44 for grasping by an operator. As a consequence the cartridge contains a pre-threaded needle along with a full spool of thread 28 for immediate use by an operator. A more detailed description of the cartridge 26 and the operating of the sewing machine is provided in the above-referenced co-pending application entitled "Sewing Machine" which is incorporated herein by reference.
The main surface of cover 25 is generally parallel to the rear surface or back wall 50 to form a housing with the interconnecting edges being generally perpendicular to back wall 50. The front edge 60 of cartridge 26 is downwardly tapered toward the needle 36 and formed integrally with the forward edge 60 at the lower end thereof is a slotted member or channel 62 in proximity to the aperture 44 formed within neck portion 42 of cartridge 26. Formed adjacent the upper front edge of cartridge 26 is a recess 64 between the inner surface of upper edge 66 of cartridge 26, the perpendicular outer surface of sidewall 56 and an integral outwardly extending short wall 68. The back wall 50 of cartridge 26 is suitably cut away to provide access to the recess 64 so-formed with the cartridge 26 separated or out of engagement with the recess 22 formed in the head 18 of the sewing machine. Extending inwardly into the recess 64 so-formed, from the front wall of the transparent cover 25 is an integral shaft projection 70 adapted for rotatably receiving thereon a spool 72 containing a strip of ribbon-like material 74 which is suitably fed through channel 62 to be in proximity to needle 36. The dimension of shaft 70 is equal to or less than the overall width of front edge 60 and by means of this construction the spool 72 is assembled within recess 64 with the cartridge 26 separated from the sewing machine. With the spool 72 in place and the cartridge 26 engaging the sewing machine head 18 within recess 22 the adjacent generally planar surface of recess 22 is generally parallel to the broad surface of transparent cover 25 thereby forming a compartment rotatably retaining spool 72 within recess 64 between the sidewalls of the compartment so-formed.
As shown in FIG. 2 the spool 72 is preferably positioned on shaft 70 so that ribbon 74 is withdrawn from the spool 72 as spool 72 rotates in a clockwise direction. In this manner when the free end of ribbon 74 is positioned adjacent bed 10 the natural tendency of the ribbon 74 is to curve inwardly toward throat 46, thereby providing relative simplicity to the use of the cartridge. The position of channel 62 and, of course, ribbon 74 is directly in line with the line of travel of fabric passing through throat 46, the fabric moving from right to left as viewed in FIG. 2. In FIG. 2 the ribbon 74 is shown beneath advance foot 48 which would be the operative position for sewing the ribbon 74 on a fabric (not shown) which would normally be positioned between the ribbon 74 and the bed 10. The ribbon 74 may be any suitable spool of ribbon-like material or the like. The spool 72 is removable and replaceable within cartridge 26 to accomodate the matching of different colors of ribbons to the color of the thread contained on the spool 28 within cartridge 26.
While there has been shown and described a preferred embodiment it is to be understood that various other adaptations and modifications may be made within the spirit and scope of the invention. | A sewing machine having a cartridge containing a spool of thread and a pre-threaded needle mounted inside of the head, the cartridge having the lower end thereof terminating in proximity to the fabric to be worked upon. The cartridge is provided with integral means for receiving a spool carrying ribbon-like material, the cartridge having a channel means integral therewith adjacent the aperture of the cartridge through which the needle passes, the spool of ribbon being so mounted, and the channel so configured, that the natural unwinding tendency of the ribbon automatically positions the ribbon on the fabric in the path of the needle. | 3 |
BACKGROUND OF THE DISCLOSURE
The present disclosure is directed to a magnetic drain plug, and especially one which is installed in the oil pan of a automotive engine equipped with a crank case. The crank case is normally filled with lubricating oil. Lubricating oil is provided to lubricate the high speed operation of the crank shaft and piston rods which connect with it. In very general terms, substantial friction is created in this area The friction is reduced by filling the crank case with lubricating oil. In turn, the lubricating oil protects the rotating equipment.
There is the risk of metal particles being formed by the equipment. Abrasion and friction form particles which collect in the crank case. These particles can be cycled with the oil time and time again through the bearings and thereby damage the bearings. It is known to remove the particles with a filter. Sometimes, the flow lines in the crank case area do not direct all the oil through the filter. Rather, the metal particles fall out and collect in the oil pan thereby creating damages. Damage commonly is noted in the cylinder walls and seal rings. U.S. Pat. Nos. 5,465,078 and also 5,634,755 are pertinent to this inquiry. The '078 patent shows a magnetic drain bolt. It includes a bolt body with a magnet. This is one approach to collecting the small metal particles. Another device is the '755 patent just mentioned. It shows a bolt body with a magnet placed in it. Both of these represent devices which have met with measured success. There are limitations to them. Among the limitations, there is the spreading of the magnetic flux lines. In general terms, for a magnet of a specified or given strength, the magnetic flux lines extend outwardly from the magnet. The distribution of these flux lines in the immediate region is determined in part by the nature of the metals which support the magnet. The magnet in the references is held by a separable bolt. There is no recognition in the two references that the flux lines need to be dealt with least wide area distribution of the flux lines creates an effective magnet which is wider in size but which is reduced in intensity. The size of the magnet is enhanced as the flux lines are spread in the immediate region. In part, this depends on the magnetic response of the metal used to fabricate the bolt. In general terms, if a ferrous metal is used, it is relatively easily magnetized. The response of ferrous metal used in the bolt body and the construction of the oil pan causes a wider distribution of the magnetic flux. That however is not an advantage as will be noted below.
The flow velocity at the point of installation in the crank case may dislodge magnetically attracted particles. They will be dislodged by the high speed of the flow. Moreover they will be held in a wider region adjacent to the prior art devices just mentioned. Specifically some particles may be drawn to the bolt head and others to the magnet. However, some magnetic particles may fall through an eddy in the flowing oil and settle out, held magnetically next to the removable drain plug. Particles held magnetically to the oil pan are hard to remove. Periodically the engine lubricating oil is drained. This done by removing the plug. The metal particles on the plug can be wiped from the plug thereby removing them from the crank case. In the instance where fluid flow velocities are great in the crank case, the particles may be knocked loose from the bolt head, flushed around the crank case, and ultimately dropped out by eddy velocities and will be held by the magnetized region of the oil pan. When the bolt is removed and cleaned, some but not all of the particles will be removed. This is clearly the inference in the '078 patent as shown in the drawings and is tacitly the net result accomplished also in the '755 structure noting FIG. 8 thereof.
The apparatus of the present disclosure provides a magnet which is held higher in the region of oil flow. It is exposed to the oil flowing above the oil pan. It is also exposed to the oil at a higher elevation in the crank case. This location has an advantage and a comparable disadvantage. One advantage is that the magnet is exposed to substantially all the oil in the crank case because it flows by with significant scavenging velocity to thereby pick up particles and circulate them in near proximity to the magnet. This increases the likelihood that a metal particle will pass by and thereby be held by the magnet. In this region there is less likelihood that particles flowing by will be caught on the magnetism otherwise found in the distributed areas of the oil pan near the drain plug. This arrangement enhances the scavenging of this approach. It is accomplished however at a cost, namely, that it is closer to the rotating equipment and the flow velocities in the lubricant are more universal. With greater velocities, the likelihood of sweeping off previously collected particles increases. To counter this, the magnet of the present invention has a greater magnetic force. The force of the magnet is normally measured in units of strength known as oersteds.
It has been determined that the magnetic strength is optimum using a magnet sold under the Model TRI-NEO 30. This is a rare earth material magnet provided by Tridus International. It is made of a mixture of neodymium-iron boron. Other rare earth permanent magnets of comparable strength are acceptable. At temperatures common to those encountered in a crank case, this rare earth magnet provides permanent magnetic attraction which is better than ceramic or alnico (aluminum, nickel and cobalt) magnets. This is a sintered material which is shaped into an appropriate form. In this particular instance the form is preferably an elongate cylinder. Roughly, the sintered form of the magnetic material (generally the rare earth magnets) has very good magnetic strength at temperatures above about 100° C. and are therefore quite acceptable in this environment. Even where the crank case temperature is maintained higher, it is not normally raised much above 120° C. because excessive temperatures damage lubricating oils. Moreover, operation in the lubrication oil prevents corrosion on the surface. In that sense, corrosion and surface damage to the magnet is reduced or even prevented. In general terms it is able to provide about four to six times the energy product of the above mentioned alnico magnets. In general terms the alnico magnets define the standard; the rare earth magnets of this disclosure will operate at the appropriate temperatures and conditions.
The present disclosure is summarized as a three part system. The visible part is the removable crank case plug. The preferred materials are ceramics or metals which have minimal ferrous content and which are therefore not readily magnetized. Dependent on machining requirements, typical metals include aluminum, brass, copper, stainless steel, and others which essentially allow permeability of about 1.000. The bolt is constructed with a threaded connector. The bolt itself may vary depending on SAE standards for that particular vehicle. In some instances, metric measurements may be involved and the thread profile may be specified. Without regard to all of that, the bolt is made in accordance with these SAE standards and is the mounting device which supports the remaining two components.
The second component is a cup which serves as a holding device. The cup is attached by threading to the bolt. The cup is uniform in size and shape. The cup or holder is equipped with a drilled receptacle to receive a rare earth magnet of cylindrical form. The cylindrical shape is uniform from model to model. This reduces inventory requirements. Moreover the bolt is made of nonferrous material so that the bolt body does not spread the magnetic flux lines and thereby magnetize everything in the immediate vicinity. In effect, this creates a more concentrated magnetic field to pick up particles flowing nearby.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to embodiments thereof which are illustrated in the appended drawings.
FIG. 1 shows the preferred embodiment of the present disclosure including a drain plug, a threaded cup holder, and cylindrical magnet; and
FIG. 2 shows an alternate embodiment utilizing a different threading system for connection of the components.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Attention is directed first to FIG. 1 of the drawings. In that view, the entire assembly is shown and is identified by the numeral 10. Beginning however from the top of FIG. 1, a drain plug 12 is shown. The drain plug incorporates a threaded body 14 which is provided with threads of the appropriate thread size and body diameter to thread into an oil pan. The threads and the length of the body are determined by SAE standards. The number of turns of threads is sufficient to enable a tight grip to be obtained and to shoulder up the surrounding flange 16. A bolt head 18 is included to unthread the drain plug 12. In the preferred structure it is made of stainless steel that has a reduced magnetic susceptibility. It is not easily magnetized. Moreover it is chosen for structural stability and ease of machining. There are other materials which are easily machined. An example is a drain plus formed of ceramics or other composite materials. So long as they can be shaped and hold their shape and provide adequate strength, they are generally sufficient for these purposes. The primary goals are the provision of a drain plug which can be threaded and unthreaded time and again in the process of providing lubrication service to the vehicle. This service inflicts modest wear and tear to the drain plug 12. Sometimes, a flat gasket or seal ring is necessary adjacent to the flange 16. As appropriate, and in accordance with SAE standards, the flange is shaped to accommodate that also.
The plug 12 has the body 14, flange 16 and bolt head 18 which are all defined in size, shape and thread shape in accordance with SAE standards. The bolt body 14 supports a threaded shaft 20. It serves as a connector. The shaft 20 therefore has a specified length. This will enable it to thread to the cooperative equipment. In addition, the shaft 20 has a specified thread system on it so that there is compatibility as will be detailed. FIG. 1 shows the cup holder 24. The cup holder is constructed with a centered cylindrical body portion 26. The interior is drilled with a hole 28 and threads are formed in that hole 28 to match the threads on the connector 20. The length of the hole 28 compared with the threaded shaft 20 will be noted. A larger cylindrical portion 30 is at the lower end. It is formed with a cylindrical opening at 32. That is a smooth wall terminating at a smooth transverse shoulder 34. The entire cup holder 24 is hollow through its centerline axis. It is hollow so that a plunger can be inserted through the hole 24 to push the cylindrical magnet out of the cup holder 24.
The system also includes an elongate cylindrical magnet formed of sintered rare earth materials. This is identified at 36. The preferred form uses the above mentioned neodymium-iron boron (Nd--Fe--B) system. Preferably the magnet has about 20 oersteds or greater field strength. The magnet 36 is typically about one-quarter to one-half inch in diameter. The length varies from about 0.5 to about 1.5 inches. Larger models can be made for larger vehicles. However, one size will normally suffice for most engines. Sizes of the components should be noted. The cylindrical magnet body 36 is preferably finished and coated with a smooth external surface. This can have the form of a metal coating, or any type of acceptable spray on plastic coating including PTFE plastic systems can be applied. The purpose of the coating is to reduce surface corrosion and to provide a relatively smooth surface so that the cylindrical magnet can be cleaned. It is inserted into the cup holder 24 and shouldered against the end of the shoulder 34. A tight fit is not needed. A suitable clearance in the cup holder of about 0.002 or greater is sufficient. That kind of clearance will enable the cylindrical magnet to be inserted into the cup holder. The cup holder covers over the exterior of about 35 to 65% of the magnet. While no specific ratio is mandated, it is desirable that the magnet be snugly fitted so that it does not drop out and is not otherwise released.
The cup holder 24 is preferably made of selected grades of magnetizable metal. A suitable machining metal stock is 4140 steel. A suitable machining metal stock is 4140 steel. By using that, magnetic lines of flux from one end of the magnetized cylinder will emerge and be distributed through the cup holder. That is not particularly a detriment because the surface area of the cup holder is not much greater than the surface area of the magnet body 36. In other words, the thickness is not significantly increased and the length is not substantially altered. The free or exposed end of the magnet is the end protruding to the greatest extent into the oil bath in the crank case. The covered end which is in the cup holder 24 is less likely to attract metal particles during the flow of lubricant around the device when installed. In that light, the system is installed so that most metal particles will magnetically attach to the cylindrical magnet 36. The open cylindrical end of the cup holder is cylindrical; in one form, it can be partially split into two or four segments to make insertion easier. This also reduces flux linkage.
The passage 28 has a length which is slightly greater than the exposed shaft 20 which serves as a connector. This assures that the threaded shaft 20 does not bump or otherwise upset the cylindrical magnetic body received in the cup holder. This assures appropriate seating without dislodging the magnet. Yet, the hole 28 is kept open prior to installation so that the magnet can be seated or removed. Removal is easily done by inserting a push rod through the opening 28 to dislodge and remove the cup holder from the magnet. In general terms, that is not needed very often.
FIG. 2 is different from the structure of FIG. 1 in that the threaded connector 20 is shown as a separate component. Depending on the ease of machining and the type of materials that are involved, the drain plug in FIG. 2 can be made separate from the threaded connector 20. In that event, the connector 40 threads in the passage 42. The system shown in FIG. 2 ultimately involves four pieces while the system shown in FIG. 1 involves only three pieces. In that sense, it is easier to assemble and is easier to install. The male and female threads (see shaft 20 or 40) are aided by an epoxy resin to lock the threads after assembly. If desired, the resin can be put in the female opening in place of the threads to adhesively join the members during assembly.
ASSEMBLY AND INSTALLATION OF THE DEVICE
Whether the embodiment of FIGS. 1 or 2 is used, the device is assembled with a drain plug that is built in accordance with SAE standards for a particular vehicle. This mandates installation of appropriate gaskets to prevent leakage. This also involves the unthreading of the device so that it can be removed and installed thereafter. Removal and installation is accomplished in the ordinary fashion. In that sense, the device is installed as any drain plug in an automobile. In a retrofit situation, the drain plug 10 is installed by first removing the stock drain plug prior to substituting this apparatus. This apparatus is assembled by first pressing the cylindrical magnetic 36 into the receptacle provided for it until it shoulders against the transverse wall 34. That type construction and assembly is carried out simply by pushing the cylinder into the receptacle. Clearance is provided because a tight fit is not needed. The two components are held together by magnetic attraction. This is done to put the components together and then the shaft 20 is threaded into the mating receptacle. The plug for the particular vehicle is sized in accordance with SAE standards. That governs the width of the flange 16, the length of the threaded body 14 and the particular threads on the body. The head 18 is normally provided with a single profile or shape, again determined by industry standards. In that circumstance, the entire assembly is then installed. Typically, this occurs after draining the crank case and removing all of the oil. The plug is put into the crank case. The crank case is refilled with oil. After refilling, the oil added surrounds the magnet completely. During operation for an interval, trash is picked up and is held on the magnet. In general terms, it is not held on the plug. Moreover, it is not held by the oil pan. Trash is located above the pan. It is high up in the oil flow. In that region, it is less likely to be attracted to the oil pan. More importantly, a magnetic circuit is not formed which otherwise would extend to the oil pan through the drain plug 12 were it made of ferrous material. In summation, the device is more effective to attract and hold metal cuttings and trash. The trash and cuttings are more easily removed. Easy removal is accomplished because the cutting cling to the cylindrical magnet 36. They do not commonly stick to the plug 12. This improved servicing in that trash and particles are removed more readily.
Periodically, the vehicle can be reserviced by draining the crank case. When that is done, the plug 10 again is removed. The improved crank case drain plug of this disclosure brings the metal shavings out in a better organized fashion. It is less likely to leave particles magnetically adherent to the inside of the crank case. It is desirable that this procedure be done on scheduled oil changes.
The device of the present invention was tested. A vehicle was selected which had received periodic maintenance. The periodic maintenance is listed in the attached chart which has entries for the date and mileage of the oil changes in the columns below. This conventional vehicle equipped with a conventional drain plug was serviced in the regular manner for all entries but the last two entries. Then, this novel device was installed. Even though it was installed in a crank case filled with fresh and presumably clean oil, it was able to pick up a number of metal shavings. The chart below identifies the dates on which this device was removed and service provided. Moreover, the device was installed at 65972 miles and when cleaned only 860 miles later, trash was removed. The trash collected was comprised of metal filings. The metal particles were larger and some were smaller. This indicates that a number of metal filings had collected in the oil pan and were not quarantined there before. The free floating particles pose a serious problem. It means that the particles stay in the crank case and are not necessarily removed after being pumped by the oil pump system through the positive pressure filter. Problems arise because particles are hard to capture. This device was able to capture the small metal particles. They were caught magnetically on the magnet 36. They did not collect on the drain plug 12. They attached preferentially to the exposed area of the cylindrical magnet 36.
This apparatus is able to remove metal shavings and particles even when the crank case oil system is protected by a filter system. Only the magnet gets and holds them permanently. Indeed, the most difficult aspect of this device is the difficulty in removing the metal shavings from the cylindrical plug 36.
While the foregoing is directed to the preferred embodiment, the scope thereof is determined by the claims which follow.
Chart______________________________________DATE ODOMETER OIL CHANGED______________________________________ 2/15/95 3537 YES 6/29/95 11542 YES10/03/95 17310 YES11/18/95 21117 YES12/29/95 23601 YES 2/09/96 26300 YES 3/22/96 29150 YES 5/10/96 32480 YES 6/15/96 35244 YES 8/17/96 37570 YES 9/28/96 39793 YES11/10/96 42273 YES12/07/96 43976 YES 2/01/97 47083 YES 3/20/97 49411 YES 5/03/97 52403 YES 6/26/97 55544 YES 9/13/97 59138 YES10/16/97 61185 YES11/21/97 63020 YES 1/15/98 65490 YES 2/07/98 65972 YES 2/24/98 66832 YES______________________________________ | A magnet set forth used is in a drain plug. A drain plug is assembled with an attached holder securing an inserted cylindrical magnet. The drain plug is formed of non ferrous material such as brass, aluminum, stainless steel, etc. It is constructed in accordance with industry standards to fit as a replacement device in oil drain pans, and is non ferrous material. It incorporates an extending threaded shaft. The holder is constructed with an axial passage there through having threads at the small end for threading through the drain plug. The passage extends fully through the device, interrupted by a transverse internal registration shoulder at the middle, and defines an extending skirt fitting loosely around an elongate cylindrical rare earth magnet. | 1 |
TECHNICAL FIELD OF THE INVENTION
The present invention relates to dismantling a gas turbine engine, in particular removing the nut connecting the high-pressure rotor to the front bearing in a twin-spool, front-fan turbofan.
PRIOR ART
A twin-spool, front-fan turbofan comprises two coaxial rotors supported by bearings housed in the hubs of two structural casing elements: referred to in the art as the intermediate casing and the exhaust casing. At the front of the engine, the bearings are mounted in the intermediate casing and, at the rear, one or more bearings are housed in the exhaust casing. In an engine such as the CFM56, the rotating assemblies are thus mounted on five bearings: three at the front and two at the rear. At the front, the fan shaft and the shaft of the low-pressure (LP) rotor are respectively mounted in the two first bearings. The high-pressure (HP) rotor is supported by bearing no. 3 , downstream of the first two. At the rear, this same HP rotor is supported by an inter-shaft bearing and the shaft of the LP rotor is supported by a bearing mounted in the hub of the exhaust casing.
After a period of operation, each engine is sent to the workshop for example for a complete overhaul, in which it is entirely dismantled and each part is cleaned, repaired or replaced if necessary. Dismantling comprises several steps, including that of removing the LP turbine module at the rear and then the module formed by the HP spool. The rotor of the HP spool comprises an upstream journal which is retained in bearing no. 3 by a connecting nut which must be unscrewed. This operation has a certain degree of difficulty per se due to the relative inaccessibility of this part. The connecting nut is a cylindrical, threaded part which serves to immobilize the upstream end of the journal of the HP rotor with respect to the inner race of the bearing. This nut comprises four teeth cut into the cylindrical wall and is located in the upstream extension of the threaded portion.
The standard procedure starts with removing the LP module to the rear and extracting the LP shaft, also to the rear. Access to the connecting nut is then possible via the central passage left free by the LP shaft. After putting in place a wedging device, which replaces the bearing which has been removed, and an internal guiding tube, an appropriately shaped tool provided with two retractable lugs at the end of a cylindrical tube is introduced into this passage as far as the nut, then the two lugs are deployed radially such that they engage against two of the four teeth of the connecting nut. As the HP rotor is prevented from rotating by a wedge, turning the tool about its axis allows the nut to be unscrewed.
This operation is delicate inasmuch as the teeth of the nut must not be damaged and the nut must not be deformed. To that end, the instructions of the engine manufacturer prescribe a maximum torque to be applied.
If the connecting nut cannot be unscrewed in this way, the procedure then consists in removing the assembly consisting of the fan and the low-pressure (LP) compressor in order to gain access to the nut via the front of the engine. Once this path is open, an appropriately shaped tool is introduced along the axis of the engine as far as the connecting nut. The head of the tool is adapted to the shape of all the teeth of the nut, such that it is possible to apply a larger torque than before and increase the chances of managing to loosen it.
However, if the connecting nut can still not be removed by this operation, it has to be cut. Cutting the nut, which is not an inexpensive or straightforward solution, is to be avoided as not only must the nut be replaced but there is a risk of the resulting chips and filings contaminating the gearing located in the immediate vicinity, which would require these parts to be removed and cleaned. This gearing, known as the IGB, serves to drive the radial arm connected to the gearbox for the accessories, the AGB.
With increasing duration or number of operating cycles of the engines, and the use thereof, where relevant, in aggressive environments, it is observed that dismantling now leads more often to the connecting nut being cut due to seizing of the nut.
Seizing of the connecting nut is due to multiple factors:
coking of the grease resulting from heating of the part, deformation of the nut during loosening, due to the torsion forces generated by the permitted torque limit being exceeded, oxidation of the portions of the nut forming the centering tracks with the journal and the inner race of the rolling bearing.
The present applicant has set itself the objective of developing a method for dismantling a motor, avoiding as far as possible the need to cut the connecting nut.
DISCLOSURE OF THE INVENTION
The invention relates to a twin-spool turbofan comprising a front fan, a HP module with a HP rotor and a LP turbine module, the intermediate casing having a bearing for supporting the HP rotor. The HP rotor is retained in the bearing of the intermediate casing by a connecting nut. The method for dismantling the engine comprises a step of introducing a tool for unscrewing the connecting nut once access to the connecting nut has been cleared, and is characterized in that it comprises a step of heating, beforehand, the connecting nut before engaging the unscrewing tool.
Previous heating to a moderate temperature makes it possible to soften the coked oils gluing together the thread of the connecting nut and that of the journal and also to allow a differential expansion between the cylindrical elements in mutual contact via close-fitting supporting surfaces.
The temperature must be kept below a safe value for the integrity of the parts present. The maximum heating temperature for an exemplary embodiment of the method is 130° C.
Preferably, once the LP turbine module, with its shaft, has been removed, a tubular heating means is introduced from behind into the central space left free by the LP turbine module, along the axis of the engine, and the connecting nut is heated from the inside.
In accordance with another feature, the heating means comprises a tube with a means for blowing hot air in via one end and radial openings at the other end so as to guide the hot air radially toward the connecting nut.
After heating the nut, a rear unscrewing tool is introduced. The tool preferably comprises a tube and a plurality of fingers which are retractable between a position in which they are housed within the tube, such that the tube can be introduced as far as the nut, and a position in which they are deployed radially so as to come into contact with the teeth of the connecting nut. An unscrewing torque is then applied to the tool, the torque being maintained at a value below that at which the forces on the teeth of the nut would risk damaging them.
According to another way of effecting the dismantling, either after an unsuccessful attempt via the rear or directly, the fan is removed so as to free up said connecting nut in the forward direction and putting in place a front unscrewing tool for applying a torque for unscrewing the nut. The front unscrewing tool preferably comprises a tubular element which is provided with teeth of a shape complementary with that of the teeth of the connecting nut; the tubular element is put in place on the nut and an unscrewing torque is applied.
The tubular element is advantageously placed in a support attached to the casing of the engine, said support forming a contact point for applying the unscrewing torque.
It is also necessary to immobilize the rotor of the HP module. To that end, the LP turbine module having been removed, the HP rotor is prevented from rotating by means of a tubular element which is engaged in the space left free by the LP module and which is attached by one end to the casing of the HP module and at the other end is secured in rotation with the HP rotor. As a safety measure, when resistance to unscrewing is observed, it is ascertained that the connecting nut has not seized, by means of a break-action torque wrench calibrated to the maximum permitted torque.
BRIEF DESCRIPTION OF THE FIGURES
The method for removing the connecting nut will now be described in more detail, according to one embodiment given by way of non-limiting example, the description being made with reference to the appended drawings, in which:
FIG. 1 is a representation in axial section of an engine to which the method according to the invention applies;
FIG. 2 is an axial half-section view showing, in situ, the nut which connects the HP rotor to the front bearing in the intermediate casing and which is to be removed;
FIG. 3 is a schematic side view of the engine during dismantling;
FIGS. 4 and 5 represent one embodiment of the device for heating the connecting nut;
FIGS. 6, 7 and 8 represent one embodiment of the device for unscrewing the connecting nut, with introduction via the rear, on the turbine side; FIG. 7 is a section through AA in FIG. 6 showing the tooling in the deployed position and FIG. 8 shows the tool in the retracted position;
FIGS. 9 to 11 show the tooling for unscrewing via the front of the engine, with the support and the tubular key;
FIG. 12 shows, in isometric section, the tool for preventing the HP rotor from rotating.
DETAILED DESCRIPTION OF THE INVENTION
The section of FIG. 1 shows a twin-spool, front-fan turbofan 1 . This figure shows, from right to left, that is to say from upstream to downstream in the direction of the gas streams, the rotor of the fan 2 inside the fan casing 2 ′. The fan duct delimited by the casing is split into two concentric annular ducts, one for the primary flow which passes through the engine, the other for the secondary flow which is expelled without having been heated. The primary flow is compressed in the low-pressure boost compressor and then in the HP compressor 3 . It is admitted into the combustion chamber 4 where it is heated by combustion of a fuel. The hot gases issuing therefrom are expanded successively in the HP turbine 5 and the LP turbine 6 before being expelled. The rotors are supported within the two structural casings which are the intermediate casing 7 —the fan casing being attached on the upstream side thereof—and the exhaust casing 8 to the rear.
The fan 2 with the boost compressor and the LP turbine 6 are connected by a LP turbine shaft 6 ′. The turbine shaft 6 ′ and the turbine 6 with its casing form, with the exhaust casing 8 , the LP turbine module 60 .
The HP compressor 3 and the HP turbine 5 form the HP rotor 35 inside the HP spool or module 40 . This also comprises the combustion chamber 4 . The HP rotor 35 is mounted at the upstream end in the bearing P 3 which is supported in the hub of the intermediate casing 7 . The gearbox referred to as the IGB, for driving the accessory gearbox (AGB) via a radial shaft housed in an arm of the intermediate casing, is also here.
FIG. 2 shows this portion of the engine in more detail; the upstream journal of the rotor 35 is housed in the inner race P 3 i of the rolling bearing P 3 via the intermediary of the pinion 9 of the IGB gearing. The connecting screw 20 is screwed at 21 to the end of the rotor 35 and immobilizes the latter axially with respect to the intermediate casing. The connecting nut 20 is therefore a cylindrical part with an inner thread 21 , an outer centering track 23 and teeth 22 in the axial upstream extension of its cylindrical wall.
Removing the HP module 40 involves, beforehand, removing the LP module 60 so as to free up access to the nut 20 and putting in place a disk 70 for retaining the HP rotor in its casing, thus replacing the inter-shaft bearing. This disk replaces the downstream inter-shaft bearing which has been removed with the LP module 60 . The state of the engine is represented schematically in FIG. 3 . The front portion, comprising the fan casing and the intermediate casing, is secured to a frame and the rear portion which is to be detached from the intermediate casing is the HP module 40 . It is attached to a beam 90 suspended from a hoist.
The following step involves introducing, into the guiding tube 41 put in place in the central space freed up by the shaft of the LP turbine, the means 100 for heating the nut 20 .
It comprises a trolley 101 mounted on wheels and having a vertical wall 103 provided with vertical rails 105 guiding a platform 107 which can move vertically. The platform is suspended from a cable which is connected, via a set of pulleys, to a manually operated winch 109 by means of which the height of the platform can be adjusted. The platform 107 supports the heating assembly consisting of a heating unit 110 and a hollow tube 112 . The heating unit is arranged at the proximal end of the tube so as to produce a flow of hot air in the hollow tube 112 , directed toward the other end of the latter. This other end is open laterally with holes 114 cut into the wall of the tube 112 , about the axis of the latter. The heating assembly also comprises a means for siting the tube and wedging it in position when it is introduced into the engine. This means is formed here by two projections 113 on a transverse plate.
The heating assembly is mounted on the platform via the intermediary of a horizontal rotation spindle 115 such that it is possible to pivot it into a vertical storage position, in which it is stowed in the trolley, or into a horizontal active position. The angular position of the heating assembly is controlled by a handwheel 117 arranged on the side of the trolley. An appropriate mechanism transmits the movement of rotation of the handwheel to the rotation of the heating assembly about the horizontal spindle 115 .
In order to heat the connecting nut 20 , the trolley is placed facing the engine and in line with the axis thereof, the heating element is brought to horizontal and introduced into the guiding tube 41 until the projections 113 are in abutment in their respective housings created in the retaining disk 70 . The end of the tube is then level with the nut. The heating unit is switched on and the hot air is blown in via holes 114 of the tube toward the connecting nut. The increase in the temperature of the connecting nut is monitored, and must not exceed 130° C. When the temperature is reached, the heating unit is switched off and the trolley is withdrawn and put away.
The second step concerns unscrewing the nut with introduction of the tooling 200 from the turbine, at the rear, into the guiding tube 41 . To that end, use is made of an unscrewing tooling comprising an unscrewing tube at the end of which are mounted four fingers which can be moved between a retracted position within said tube, allowing the tube to be moved along the inner tubular space 41 , and a deployed position in which they extend radially out from the cylindrical wall of the unscrewing tube. In this latter position, and by applying a rotational torque about the axis of the tube, the four fingers press against a lateral edge of each tooth and transmit the unscrewing forces thereto. By providing a number of fingers which is equal to the number of teeth of the connecting nut, a better distribution of the forces, compared to with only two fingers, is ensured. It follows that a higher torque can be applied, increasing the chances of managing to loosen the nut.
FIGS. 6 to 8 show a section of a tooling suited to the method. This tooling 200 comprises a tubular element 201 inside which is housed the mechanism for deploying and then retracting the fingers for contact with the teeth of the connecting nut.
The mechanism for actuating the fingers comprises a disk 210 arranged across the tube, at the end thereof; the disk has four radial grooves 211 arranged in a cross, for housing each of the fingers 212 . These are connected to connecting rods 213 which are articulated to an actuating member 214 , as shown in FIGS. 7 and 8 for two positions of the fingers. By turning the actuating member on itself, about its axis, one way or the other, the fingers are made to adopt, by means of the action of the connecting rods, a retracted or extended position, depending on the direction. The disk 210 is secured to a tubular element 216 surrounding the member 214 for actuating the fingers. The tubular element 216 is secured to a toothed wheel 217 in order to be driven in rotation. The tubular element 201 is arranged so as to be made immobile with respect to the HP module 40 . To that end, it comprises projections which are not shown here and which, as in the means for heating the connecting nut, engage with the retaining disk 70 . At its other end, the tube is provided with pegs 218 which are designed to be engaged in grooves of the HP rotor journal in order to help prevent any rotation of the HP rotor 35 while the loosening torque is applied to the nut. Finally, the tube 201 is associated with vanes 219 which are able to move radially, actuated by the handwheel 222 , and which serve to extract the brake of the nut 20 before loosening.
An upstream guiding member 220 is also shown in this figure. It is of smaller diameter than the tube 201 and serves to center the tooling 200 via a tooling which is provided to that end and which is mounted on the fan 2 .
After heating the connecting nut, the tooling is introduced into the central space until the lateral projections, not shown, abut against the device 110 . The disk is then facing the teeth of the nut. The fingers are then deployed radially by means of a determined angular rotation of the control member 223 t . With one or more fingers having a lateral tab, the disk is turned such that the tabs slide into the corresponding grooves created below the teeth.
In the abutment position, it is known that, at the upstream end of the tube (not shown from the rear), the axial pegs are engaged in the corresponding axial grooves of the inside of the journal of the HP rotor 35 . While still in position and wedged, a torque multiplier, for example that known under the Sweeney brand, is put in place.
It is ascertained that the connecting nut has not seized, by means of a break-action torque wrench calibrated to the maximum permitted torque. If the wrench yields and folds in two, the maximum permitted torque has been exceeded; the nut is deemed to be stuck, and unscrewing from the front must be attempted. If the wrench does not break, a motor, for example a compressed air motor, is put in place on the torque multiplier and the connecting nut is first loosened and then unscrewed.
The method for removing the connecting nut from the front involves, first of all, removing the assembly formed by the fan, the boost compressor and the bearings P 1 and P 2 in order to have a direct view of the nut from the front.
As in the method for removing via the turbine, and in the same manner, the connecting nut is heated beforehand with the aid of the tooling 100 . Then, the front unscrewing tool 300 is put in place on the engine, FIGS. 9, 10 and 11 . The tool comprises two parts: a key support 310 secured to the casing of the engine, and a tubular key 320 which is able to turn about its axis in the support. The assembly is shown in FIG. 9 . The support 310 comprises four branches 312 which extend in a star shape from a cylindrical stem 311 . The support comprises removable shoes 322 . The operator installs shoes which are appropriate for the type of engine, such that it is possible to attain the correct interfaces for attachment to the casing. The branches and the shoes 322 have at their end holes 313 through which can pass screws for attaching to the intermediate casing. The tubular key 320 is housed in the cylindrical stem such that it is blocked axially but can rotate freely about its axis. The key comprises two circular supporting surfaces 321 which come to place themselves in the corresponding ring 314 . A removable ring 315 closes the space of the groove in the upstream direction so as to lock the key axially in the support. The key comprises, at one end, four teeth 316 of a shape complementary with the teeth 22 of the connecting nut 20 and, at its other end, a pinion 317 for driving it in rotation. The key also comprises a thin ring 323 which serves to push away the brake of the nut 20 before loosening.
Once the tool 300 has been put in place, a wedging tube 350 , FIG. 12 , is arranged inside the HP rotor so as to prevent it from rotating. This tube comprises a transverse plate with locating projections 353 which come into abutment in corresponding notches in the disk 70 . Pegs 351 , which engage with axial grooves of the HP rotor so as to immobilize the latter, are placed at the end of the tube.
The operating method comprises the following steps:
Heating the connecting nut by means of the heating device 100 up to a temperature not exceeding 130° C. Putting in place the rear loosening tooling 200 . Putting in place a force multiplier on the pinion, for example a device of the Sweeney type. Ascertaining that the connecting nut can be loosened by applying a torque lower than the limit permitted by the manufacturer, by means of a break-action torque wrench engaged in the Sweeney force multiplier. If the wrench allows the pinion to be rotated without folding, then the connecting nut has not seized and a pneumatic motor is put in place to drive the pinion. If the torque wrench indicates that the maximum torque has been exceeded, loosening via the front must be contemplated. Heating via the front comprises the following steps: Heating the connecting nut by means of the heating device 100 , up to a temperature not exceeding 130° C. Putting in place the front loosening tooling 300 . Mounting the support 310 onto the intermediate casing and screwing the four branches to the orifices existing therein. Introducing the unscrewing key 320 into the stem of the support until the toothed end is engaged between the teeth of the nut. Axially locking the key by means of the ring 315 on the support. Preventing the HP rotor 35 from rotating, for example by means of a wedging tube 350 provided with wedging pegs. Putting in place a force multiplier on the pinion 317 , for example a device of the Sweeney type. Ascertaining that the connecting nut can be loosened by applying a torque lower than the limit permitted by the manufacturer, by means of a break-action torque wrench engaged in the Sweeney force multiplier. If the wrench allows the pinion to be rotated without folding, then the connecting nut has not seized and a pneumatic motor is put in place to drive the pinion. If the torque wrench indicates that the maximum torque has been exceeded, cutting the nut must be contemplated.
The method of the invention is thus an improvement with respect to the prior art since, with this method, it has been noted that the number of instances of the nut being cut after application of the procedure has been reduced considerably and notably. | A method for removing a twin-spool turbine including a front fan, a HP module with a HP rotor, and a LP turbine module, an intermediate casing including a support bearing for the HP rotor, the HP rotor being retained in the bearing by a link nut, the method including inserting a tool for unscrewing the link nut after having released access to the link nut, and preheating the link nut before starting the unscrewing tool. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to an apparatus for supporting a reading article in an open reading position, and, more particularly, to an adjustable apparatus permitting a variety of adjusting motions so as to ensure proper angle and line of vision of the reading article with respect to the reader. Moreover, the present invention is directed to a portable support apparatus capable of assuming a collapsed condition thereby facilitating storage and transport thereof.
2. Description of Related Art
Many people, particularly students, office workers, etc. complain of neck pain while reading in a sitting position. This pain is caused by poor posture due to a forward flexed head position necessary to read the material lying on the table or desk top. Forward flexion of the head at angles greater than 20 degrees lead to pain and fatigue of the posterior neck muscles. Prolonged awkward postures such as this is a causative factor of cumulative trauma disorder. Although sometimes referred to as repetitive motion injuries, cumulative trauma disorders involve factors such as repetitive motions, mechanism stress, and improper postures among others. These factors require more muscle effort, allowing less recovery time which can lead to fatigue and scarring and weakening of structures such as ligaments, disks, muscles, bones, nerves, blood vessels, and tendons. If such injuries are ignored, chronic pain or disability may often be the end result.
It is known in the art to utilize reading article supports or stands to orient an article in an open reading position. See, e.g., U.S. Pat. Nos. 2,501,019 to Attick; 3,952,989 to Bannister Hatcher and 4,886,231 to Doerksen. Although not specifically intended to minimize the degree of flexion of the head, these devices inherently provide some relief to the reader in that the article is supported in a general upright position. Consequently, the line of sight of the reader is improved, i.e., more horizontally oriented as compared to the line of sight defined with the reading article lying flat on, for example, a table top.
Although known prior art devices have proven to be generally effective in maintaining reading material in an open upright position, these devices have their own particular shortcomings which detract from their usefulness. For example, such devices are limited with respect to their adjustability along several axes, i.e., along a horizontal and/or vertical plane, and with respect to the adjustability of the angular orientation of the reading article. In addition, the devices are generally complicated requiring a number of component parts, thus increasing the difficulty of operation. Moreover, known devices are not particularly adapted to handle reading articles of varying sizes, particularly, large or oversized reference books.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to an apparatus which addresses the disadvantages of the prior art. Generally speaking, the invention is directed to an apparatus for supporting a reading article in an open position. The apparatus includes a base member having a base supporting surface for supporting a reading article along a lower edge of the reading article when in an open position and being appropriately dimensioned to accommodate reading articles of varying sizes, and a backing member operatively connected to the base member and extending at least in a vertical direction relative to the base member and having a backing support surface for supporting the reading article. The base member is foldable preferably along a hinge to a closed position thereof to be in superposed relation with respect to the backing member. At least one leg member may be associated with one of the base member and the backing member. The one leg member is selectively adjustable to at least adjust the vertical positioning of the base member to thereby at least adjust the vertical position of the reading article. Means may be provided for releasably securing the one leg member at a plurality of predetermined positions with respect to the base member. Preferably, the one leg member is telescopically received within a correspondingly dimensioned bore defined within the backing member.
At least one brace member may be connected to the backing member. The one brace member is movable to selectively adjust the angular orientation of the backing member. A locking brace may be provided and connected to either the base member or the backing member. The locking brace is engagable by the brace member to selectively position the backing member at a desired angular orientation. Preferably, at least two brace members are provided whereby a first of the brace members is connected to an upper portion of the backing member and a second of the brace members is connected to the first brace member and engagable with the locking brace. The first and second brace members are preferably adapted for relative movement to adjust the effective length of the two members thereby providing another manner to adjust the angular orientation of the backing member. A securing member may be associated with the brace members and is movable to secure the relative positioning of the first and second brace members.
The apparatus may further include at least one lower article clamp associated with the base member and moveable in a lateral direction with respect to the backing member to releasably engage a lower portion of the reading article. A locking member for securing the lower article clamp at a plurality of predetermined lateral positions may be provided. Preferably, the lower article clamp is rotatable about an axis of rotation to assume a closed position in general superposed relation with respect to the base member.
The apparatus may further include an upper article clamp associated with the backing member and dimensioned and configured to releasably engage an upper portion of the reading article. Preferably, at least the vertical positioning of the upper article clamp is adjustable relative to the backing member to accommodate reading articles of varying heights.
In an alternate embodiment, the apparatus for supporting a reading article includes a base member having a base supporting surface for supporting a reading article along a lower edge of the reading article when in an open position, a backing member operatively connected to the base member and extending at least in a vertical direction relative to the base member and having a backing support surface for supporting the reading article, and at least one leg member associated with one of the base member and the backing member. The one leg member is selectively adjustable to at least adjust the vertical positioning of the base member to thereby at least adjust the vertical positioning of the reading article.
In another alternate embodiment, the apparatus for supporting a reading article includes a base member having a base supporting surface for supporting a reading article along a lower edge of the reading article when in an open position, a backing member operatively connected to the base member and extending at least in a vertical direction relative to the base member and having a backing support surface for supporting the reading article, and an upper article clamp associated with the backing member to releasably engage an upper portion of the reading article. Preferably, at least the vertical positioning of the upper article clamp is adjustable to accommodate reading articles of varying heights.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the disclosure are described herein with reference to the drawings wherein:
FIGS. 1-2 are frontal and rear perspective views of the apparatus constructed in accordance with the principles of the present invention;
FIG. 3 is a perspective view similar to the view of FIG. 1 illustrating a reading article supported by the apparatus;
FIG. 4 is a cross-sectional view of a lower article clamp for releasably engaging a lower portion of the reading material;
FIGS. 5A-5B are cross-sectional views similar to the view of FIG. 4 illustrating the lower article clamp biased inwardly by a spring mechanism;
FIG. 6 is a partial perspective view illustrating movement of the lower article clamps to a closed position in superposed relation with the base member;
FIG. 7 is a cross-sectional view of a leg member telescopically received within a bore of the backing member to adjust the vertical position of the base member;
FIG. 8 is a cross-sectional view taken along the lines 8--8 of FIG. 2 illustrating the locking mechanism for securing the relative positioning of the first and second brace members;
FIG. 9 is a rear perspective view illustrating folding of the brace members in accordance with a preferred sequence of folding the apparatus;
FIG. 10 is a view similar to the view of FIG. 9 illustrating the locking member folded onto the brace members in accordance with the preferred sequence; and
FIG. 11 is a frontal perspective view illustrating folding of the base member in superposed relation relative to the backing member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now in detail in which like reference numerals identify similar or like elements throughout the several views, FIGS. 1-3 illustrate, in perspective, the apparatus 10 constructed in accordance with the principles of the present invention. Apparatus 10 is intended to support a reading material or article in an open position and, as will be further appreciated from the description provided hereinbelow, is readily adaptable to accommodate articles ranging in a variety of sizes. Apparatus 10 is also adjustable with respect to its vertical, horizontal and angular positions to ensure reader comfort and to satisfy ergonomic concerns. Moreover, apparatus 10 is readily collapsible to be positioned in a brief case, book bag, etc. . . . for ease of transport.
Apparatus 10 includes backing member 12 and base member 14 connected to the backing member 12 through first and second hinge elements 16. Base member 14 defines base supporting surface 18 which is intended to support the lower edges of reading article A (e.g., a book, magazine, journal, etc. . . . ) (FIG. 3). Base supporting surface 18 is advantageously dimensioned to accommodate reading articles of varying sizes and thicknesses and preferably ranges in length "L" from about 9 inches to about 18 inches, more preferably 12 inches and in width "W" from about 1 inch to about 6 inches, more preferably 3 inches. Base supporting surface 18 defines a general horizontal plane when in the open position as depicted in FIG. 1.
Backing member 12 defines a backing support surface 12a extending in a general vertical direction when in the open position. Backing member 12 preferably ranges in height "H" from about 10 inches to about 20 inches, more preferably about 14 inches. Further details of backing member 12 will be discussed in more detail hereinbelow.
With reference now to FIG. 4, in conjunction with FIG. 1, first and second article clamps 20 are mounted to base member 14. Article clamps 20 are intended to releasably engage the lower portion of the reading article "A" to maintain the article in the open position depicted in FIG. 3. Article clamps 20 are generally U-shaped as shown and possess an article engaging segment 22 which engages the pages of the article support "A". The remote end of each article engaging segment 22 has an engaging knob 23 which directly contacts the pages of the reading article. Knobs 23 are preferably fabricated from a suitable rubber or polymeric material to enhance frictional engagement with the pages of the article "A". In a preferred mounting arrangement of article clamp 20, a mounting segment 24 of each article clamp 20 is received within a correspondingly dimensioned lateral or transverse bore 26 defined in base member 14 to mount the article clamp 20 to the apparatus. Each article clamp 20 is laterally movable (as shown in phantom in FIG. 4) relative to backing member 12 as provided by translation of mounting segment 24 through bore 26, to accommodate books of varying thicknesses. A pair of winged locking bolts 28 may be provided to engage mounting segments 24 of article clamp 20 to secure each clamp at a desired lateral position. Locking bolts 28 are received within threaded bores 30 extending from the lower surface of base member 14. It is also envisioned that one article clamp 20 (instead of two) may be utilized to accomplish the objectives of the present invention.
FIGS. 5A-5B illustrate an alternate embodiment of the article clamps 20. In accordance with this embodiment, each article clamp 20 is normally biased toward backing member 12 by coil spring 32. In particular, coil spring 32 is mounted within a recessed section 34 of base member 14 and engages at one end support surface 36 of base member 14 and at its other end spring collar 38 of the article clamp 20. Spring collar 38 is fixed about the outer surface of mounting segment 24 of article clamp 20 or may be integrally formed therewith. With this arrangement, article clamp 20 is normally biased in a direction toward backing member 12 thus causing engaging segment 22 and knob 23 to engage the reading article "A". FIG. SB illustrates coil spring 32 in a compressed condition corresponding to a position of article clamp 20 when in engagement with the reading article "A".
With reference now to FIG. 6, in conjunction with FIG. 4, article clamp 20 is rotatably movable about an axis of rotation extending through mounting segment 24 between an operative position depicted in FIG. 4 and the non-operative position depicted in FIG. 6. In the non-operative position, article clamp 20 is in superposed relation with base member 14. Preferably, base member 14 includes first and second mounting grooves 40 extending through support surface 18 of base member 14 to receive article clamps 20 when in the non-operative position to thereby reduce the overall profile of the folded base member 14.
Referring again to FIGS. 1-3, apparatus 10 further includes an upper article clamp 42 which is configured to releasably engage the upper portion of the reading article "A". Upper article clamp 42 is preferably a conventional spring clamp pivotally movable between the closed position depicted in FIG. 1 and the open position depicted in FIG. 3. Other types of clamps are envisioned as well such as the article clamp 20 described hereinabove. Article clamp 42 is mounted to clamp support plate 44, which is, in turn, slidably mounted to backing member 12. In a preferred arrangement, the edge portions 44a of clamp support plate 44 are received within correspondingly dimensioned longitudinal slots 46 defined between side mounts 48 and the support surface 12a of backing member 12. Side mounts 48 may be integrally formed with backing member 12 or may be separate components affixed to the backing member 12 as shown. Clamp support plate 44 is selectively movable in a general vertical direction as indicated by the directional arrow of FIG. 1 to selectively adjust the vertical positioning of article clamp 42, thus, to accommodate books of varying height. As best depicted in FIG. 2, a plurality of wing bolts 50 extend through the rear surface of backing member 12 and engage the rear surface of clamp support plate 44 to positively fix the clamp support plate 44 at a desired vertical position. Wing bolts 50 may be similar in function and structure to those described in connection with lower article clamp 20.
Thus, the movement of clamp support plate 44 relative to backing member 12 enables the user to increase the effective length of backing member 12 so as to provide support for significantly large (in length) books. It is to be noted that clamp support plate 44 may move toward base member 12 to a position whereby lower edge 44b (FIG. 1) of clamp support plate 44 engages base member 14 to accomodate books smaller in length.
Referring now to FIG. 7, in conjunction with FIGS. 1-2, apparatus 10 further includes first and second vertical leg members 52 telescopically received within correspondingly dimensioned bores 54 extending through backing member 12. Leg members 52 are slidably movable within bores 54 to selectively adjust the vertical positioning of base member 14. Accordingly, the vertical location of the reading article "A" may be selectively adjusted to ensure the article "A" is at a proper reading level to minimize forward flexion of the head. As depicted in FIG. 2, a plurality (two are shown) of wing bolts 56 extend from the rear through threaded bore 58 of backing member 12 to engage vertical leg members 52 to secure the vertical leg members 52 at any desired position. Leg members 52 may have suction cups 60 at their remote ends to enhance engagement with the table top.
With continued reference to FIG. 2, in conjunction with FIG. 8 which is a cross-sectional view taken along the lines 8--8 of FIG. 2, apparatus 10 further includes first and second brace members 62, 64 which permit adjustment of the angular orientation of backing member 12. First brace member 62 is pivotally connected to the upper portion of backing member 12 through hinge joint 66. Second brace member 64 is slidably mounted to first brace member 62 via a pin and slot arrangement. In particular, each brace member 62, 64 includes a longitudinal slot 68 in general alignment with the respective slot of the other brace member. A pair of mounting wing bolts 69 extend through the corresponding slots 66. Preferably, first brace member 62 has locking nuts 70 (FIG. 8) which threadably engage mounting bolts 69 to thereby secure the brace members 62, 64 at a plurality of relative positions. Second brace member 64 is slidably movable relative to first brace member 62 to adjust the overall effective length of the brace members 62, 64, the significance of which will be appreciated from the description provided hereinbelow.
With particular reference to FIG. 2, a locking brace 72 is pivotably connected to the lower rear surface of backing member 12 through hinge joint 74. Locking brace 72 is advantageously configured to be engaged by the first and second brace member 62, 64 arrangement to maintain the first and second brace members 62, 64 at a desired angular orientation with respect to the backing member 12. Accordingly, the angular orientation of backing member 12 may be adjusted to selectively orient the angular orientation relative to the vertical of the reading article "A". Locking brace 72 includes a plurality of transverse slots 74 which receive the lower edge 64a of second brace member 64 to maintain the first and second brace arrangement 62, 64 at a desired orientation, i.e, to position the backing member 12 towards a more vertical orientation, lower edge 64a is positioned in one of the slots 74 proximate backing member 12. To position backing member 12 at a more inclined orientation, lower edge 64a of second brace member 64 is positioned in one of the slots 74 remote to backing panel 12.
It is to be appreciated that the overall effective length of the first and second brace arrangement 62, 64 may also be adjusted to control the angular orientation of backing member 12, i.e. the effective length may be increased which would position the backing member 12 in a more vertical position. Alternatively, the effective length may be decreased which would position the backing member 12 at a more inclined position. It is also envisioned that locking brace 72 may be removed whereby the lower edge 64a of second brace member 64 would contact the desktop or table with the angular orientation of backing member 12 adjusted solely through the changing of the effective length of the brace members 62, 64 in the manner discussed above. With this arrangement, a rubber surface may be adhered to the lower edge 64a of second brace member 64 to facilitate engagement with the table surface. Alternatively, a suction cup such as that described in connection with leg members 52 may be utilized to engage the table top.
Referring now to FIGS. 9-11, collapsing of the apparatus to facilitate transport will be discussed. Initially, first and second brace members 62, 64 are disengaged from locking brace 72. Second brace member 64 is then moved relative to first brace member 62 such that the lower edges of the brace members 62, 64 are in general alignment. Thereafter, the brace members 62, 64 are pivoted along hinge 66 such that they are positioned flat against the rear of backing member 12. Locking brace 72 is pivoted upwardly against brace members 62, 64 as depicted in FIG. 10. Preferably, locking brace 72 includes two apertures 76 formed therein to receive wing bolts 68 to ensure that the locking brace 72 lies flat against second brace member 62. Locking brace 72 has a Velcro™ strip 78 which engages Velcro™ strip 80 on second brace member 64 to retain the locking brace 72 in the secured position. Other means for retaining locking brace 72 in the secured position are envisioned as well including locking hooks, tabs, etc. . . .
With reference now to FIG. 11, leg members 52 are moved upwardly by disengaging wing bolts 56 and advancing the leg members 52 within bores 54 of backing member 12. Wing bolts 56 may then be tightened to ensure that the leg members 52 are secured in this position. Base member 14 is then pivoted upwardly along hinges 16 to the superposed position with respect to backing member shown in FIG. 11. Velcro strips 82, 84 (FIG. 1) disposed on base member 14 and backing member 12, respectively, may be utilized to maintain the base member 14 in the secured position.
Thus, the apparatus of the present invention can support a reading article in a sturdy upright position and is readily adjustable to ensure a proper line of sight regardless of the reader's position or location of the table top. The apparatus can be collapsed to facilitate transport and storage. Preferably, the structural components are fabricated from a polymeric material through injection molding techniques although it is envisioned that wood or stainless steel may be used as well.
While the above description contains many specifics, these specifics should not be construed as limitations on the scope of the invention, but merely as an exemplification of a preferred embodiment thereof. Those skilled in the art will envision other possible variations that are within the scope and spirit of the invention as defined by the claims appended hereto. | An apparatus for supporting a reading article in an open position includes a base member having a base supporting surface for supporting a reading article along a lower edge of the reading article when in an open position and being appropriately dimensioned to accommodate reading articles of varying sizes and a backing member operatively connected to the base member and extending at least in a vertical direction relative to the base member and having a backing support surface for supporting the reading article. The apparatus is adjustable along several axes, i.e., along both horizontal and vertical planes, to selectively position the reading material at a desired reading level. The angular orientation of the article is also adjustable. The support apparatus is capable of supporting books of varying sizes including oversized reference books or the like. The apparatus is also collapsible for ease of transport and/or storage. | 0 |
BACKGROUND
[0001] 1. Field of Use
[0002] The present invention relates generally to electrical safety devices and more particularly to a Leakage Detection and Interruption (LCDI) device having ignition containment features.
[0003] 2. Description of Prior Art
[0004] Conventional electrical appliances typically receive alternating current (AC) power from a power supply, such as an electrical outlet, through a pair of conducting lines. The pair of conducting lines, often referred to as the line and neutral conductors, enable the electrical appliance, or load, to receive the current necessary to operate.
[0005] A power cable typically comprises at least two conducting lines through which current travels from the power source to the load. Specifically, a power cable typically comprises a power line and a neutral line. A metal sheath can be used to surround the power line and the neutral line in order to provide the power cable with arc sensing capabilities.
[0006] The connection of an electrical appliance to a power supply through a pair of conducting lines can create a number of potentially dangerous conditions. In particular, there exists the risk of ground fault and grounded neutral conditions in the conducting lines. A ground fault condition occurs when there is an imbalance between the currents flowing in the power and neutral lines. A grounded neutral condition occurs when the neutral line is grounded at the load.
[0007] Ground fault circuit interrupters are well known in the an and are commonly used to protect against ground fault and grounded neutral conditions. A ground fault circuit interrupter (GFCI) typically comprises a differential transformer with opposed primary windings, one primary winding being associated with the power line and the other primary winding being associated with the neutral line. If a ground fault condition should occur on the load side of the GFCI, the two primary windings will no longer cancel, thereby producing a flux flow in the core of the differential transformer. This resultant flux flow is detected by a secondary winding wrapped around the differential transformer core. In response thereto, the secondary winding produces a trip signal which, in turn, serves to open at least one of the conducting lines between the power supply and the load, thereby eliminating the dangerous condition.
[0008] While GFCI circuits of the type described above are well known and widely used in commerce to protect against ground fault and grounded neutral, conditions, it should be noted that a power cable is susceptible to other types of hazardous conditions which are not protected against by a conventional GFCI circuit. As an example, it has been found that one type of arcing condition can occur between one of the conducting lines and the metal sheath which surrounds the conducting lines. It should be noted that the presence of this type of arcing condition between either the power line and the metal sheath or the neutral line and the metal sheath can result in a fire or other dangerous condition.
[0009] When an electrical spark jumps between two conductors or from one conductor to ground the spark represents an electrical discharge through the air and is objectionable because beat is produced as a byproduct of this unintentional “arcing” path. Such arcing faults are a leading cause of electrical fires. Arcing faults can occur in the same places that ground faults can occur—in fact, a ground fault would be called an arcing fault if it resulted in an electrical discharge, or spark, across an air gap. Arc fault detection is typically accomplished by monitoring the electrical current flow into a load and comparing the profile of this current flow to a characteristic “signature' that arcing faults will exhibit it is known for ALCI enclosures to “burn up” during an internal fire or ignition creating extreme hazards and dangerous conditions.
[0010] In U.S. Pat. No. 7,525,777, to Aromin, V, incorporated herein by reference for all it discloses, new and improved safety circuits for a power cables are disclosed. The power cable includes two or more conducting lines and a metal sheath surrounding the conducting lines. The safety circuits sense the presence of an arcing condition between one of the conducting lines and the metal sheath, and in response thereto, opens at least one of the conducting lines between the power supply and the load.
[0011] Although a variety of safety circuits are available to shut down an ALCI is response to hazardous arcing conditions there is a need for an ALCI that can contain “burn up” during an internal fire through the use of fire retardant materials and structure located on the circuit assembly.
BRIEF SUMMARY
[0012] The foregoing and other problems are overcome, and other advantages are realized, in accordance with the presently preferred embodiments of these teachings. In accordance with one embodiment of the invention a Leakage Current Detection and Interruption Device (LCDI) with Ignition Containment features is disclosed.
[0013] The structure of the LCDI circuit card assembly incorporates a load input cavity having fire retardant materials surrounding the load input terminals, and further includes a contact actuator which encases the switch or contact arm at the source input section of the LCDI. Further, the particular placement of components on the circuit card assembly is to maximize the fire containment features of the LCDI. The circuit card assembly incorporates either 120 Volt, 240 Volt 15 Amp, or 240 Volt 20 Amp source input conductors.
[0014] Components and circuit traces mounted and or adhered to the LCDI Circuit Card assembly are configured to minimize packaging density while simultaneously maximizing distances between component and circuit traces to conform to required safety standards, e.g., UL840, to prevent electric arcing, and dielectric breakdown. A safety circuit for a power cable is included and disposed on the circuit assembly which includes two or more conducting lines and a metal sheath surrounding the conducting lines.
[0015] The safety circuit senses the presence of an arcing condition between one of the conducting lines and the metal sheath, and in response thereto, opens at least one of the conducting lines between the power supply and the load. The safety circuit and circuit card assembly may be mass produced, has a minimal number of parts, and can be easily assembled.
[0016] The safety circuit is for use with a power cable, said power cable connecting a power source with a load, said power cable comprising a power line, a neutral line and a metal sheath which surrounds the power line and the neutral line, said safety circuit comprising a circuit breaker comprising a first switch located in one of said lines between the power source and the load, said switch having a first position in which the power source in its associated line is connected to the load and a second position in which the power source in its associated line is not connected to the load, a circuit opening, device for setting said switch in either its first position or its second position, said circuit opening device being operable in either a first state or a second state, said circuit opening device setting said switch in its first position when in its first state and said circuit opening device setting said switch in its second position when in its second state, a first silicon controlled rectifier (SCR) for detecting the presence of an arcing condition between one of said lines and the metal sheath, said first SCR setting said circuit opening device at its second state upon detecting the presence of an arcing condition between one of said lines and the metal sheath.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0018] FIG. 1 is a schematic circuit diagram of an embodiment of a safety circuit used in the Leakage Current. Detection and Interruption Device (LCDI) of the present invention;
[0019] FIG. 2 is another schematic circuit diagram of an embodiment of a safety circuit used in the LCDI of the present invention;
[0020] FIG. 3 is another schematic circuit diagram of an embodiment of a safety circuit used in the LCDI of the present invention;
[0021] FIG. 4 is another schematic circuit diagram an embodiment of a safety circuit used in the LCDI of the present invention;
[0022] FIG. 5 is a perspective top view of an LCDI enclosure employing the principles of subject invention;
[0023] FIG. 6 is a perspective bottom view of an LCDI enclosure with 240 Volt 20 Amp source conductors employing the principles of subject invention;
[0024] FIG. 7 is a perspective bottom view of an LCDI enclosure with 240 Volt 15 Amp source conductors employing the principles of subject invention;
[0025] FIG. 8 is a perspective bottom view of an LCDI enclosure with 120 Volt source conductors employing the principles of subject invention;
[0026] FIGS. 9 through 13 illustrate a circuit assembly for an LCDI employing the principles of subject invention;
[0027] FIG. 11A illustrates an exploded view of FIG. 11 ;
[0028] FIG. 14 illustrates a circuit card assembly mounted in a bottom LCDI housing employing the principles of subject invention;
[0029] FIGS. 15 and 16 illustrate a circuit card assembly having a connected load input cable employing the principles of subject invention.
DETAILED DESCRIPTION
[0030] Referring now to FIG. 1 there is shown a first embodiment of a safety circuit constructed according to the teachings of the present invention, the safety circuit being represented generally by reference numeral 1011 . Safety circuit 1011 is designed principally for use as a safety device for a power cable P which connects a power source (i.e., a line) to a load, said power cable P including a power line L, a neutral line N, and a ground line G. Each of the power and neutral lines L and N is wrapped with a metal sheath or other similar type of shielded wrapping.
[0031] The metal sheaths of the power and neutral lines L and N are, in turn, twisted together so as to effectively form a single metal sheath S 1 which surrounds power line L and neutral line N. Ground line G remains electrically isolated from power line L and neutral line N.
[0032] As will be discussed in detail below, safety circuit 1011 interrupts the flow of current through power line L and neutral line N extending between the power source and the load when an arcing condition occurs either between power line L and metal sheath S or between neutral line N and metal sheath S 1 . As can be appreciated, the presence of an arcing condition either between power line L and metal sheath S or between neutral line N and metal sheath S can result in a fire or other dangerous condition.
[0033] Safety circuit 1011 comprises a circuit breaker 13 which selectively opens and closes power line L and neutral line N. Circuit breaker 13 includes a first normally-closed switch K 1 which is located in power line L between the power source and the load. Circuit breaker 13 also includes a second normally-dosed, switch K 2 which is located in neutral line N between the power source and the load. Switches K 1 and K 2 can be positioned in either of two connective positions. Specifically, switches K 1 and K 2 can be positioned in either a first, or closed, position or a second, or open, position. With switches K 1 and K 2 disposed in their closed position, which is the opposite position as illustrated in FIG. 1 , current is able to flow from the power source to the load. With switches K 1 and K 2 disposed in their open position, which is illustrated in FIG. 1 , current is unable to flow from the power source to the load.
[0034] A metal-oxide varistor MOV 1 protects against voltage surges in power and neutral conducting lines L and H. Metal-oxide varistor MOV 1 preferably has a model number of Z151 and includes a first terminal 61 and a second terminal 63 . First terminal 61 of metal-oxide varistor MOV 1 is connected to power line L and second terminal 63 of metal-oxide varistor MOV 1 is connected to neutral line N.
[0035] A solenoid SOL is ganged to the circuit breaker contacts of switches K 1 and K 2 and is responsible for selectively controlling the connective position of switches K 1 and K 2 . Specifically, when solenoid SOL is de-energized, switches K 1 and K 2 remain in their closed positions. However, when solenoid SOL is energized, solenoid SOL moves and maintains switches K 1 and K 2 into their open positions. Solenoid SOL includes a winding 15 which includes a first end 17 and a second end 19 , second end 19 being connected to power line L. It should be noted that safety circuit 1011 is not limited to the use of solenoid SOL to selectively move and maintain the connective position of switches K 1 and K 2 . Rather, it is to be understood that solenoid SOL could be replaced with alternative types of circuit opening devices which are well known in the art without departing from the spirit of the present invention.
[0036] A first silicon controlled rectifier SCR 1 acts to detect the presence of an arcing condition between the power line L and the metal sheath S 1 and to switch solenoid SOL from its de-energized state to its energized state upon detecting the presence of the arcing condition between the power line L and the metal sheath S. First silicon controlled rectifier SCR 1 preferably has a model number of ECI03B and includes an anode 21 , a cathode 23 and a gate 25 .
[0037] Diode bridge 1013 comprises four diodes D 91 , D 92 , D 93 and D 94 , each diode preferably having a model number of IN4004. Diode D 91 includes an anode 1015 connected to cathode 23 of silicon controlled rectifier SCR 1 and a cathode 1017 connected to first end 17 of solenoid SOL. Diode D 92 includes an anode 1019 connected to cathode 1017 of diode D 91 and a cathode 1021 connected to anode 21 of silicon controlled rectifier SCR 1 . Diode D 93 includes an anode 1023 connected to neutral line N at the power source and a cathode 1025 connected to anode 21 of silicon controlled rectifier SCR 1 . Diode D 94 includes an anode 1027 connected to cathode 23 of silicon controlled rectifier SCR 1 and a cathode 1029 connected to neutral line N at the power source.
[0038] In use, diode bridge 1013 in safety circuit 1011 acts to detect the presence of an arcing, condition between neutral line N and metal sheath S 1 and to switch solenoid SOL from its de-energized state to its energized state upon detecting the presence of the arcing condition between neutral line N and metal sheath S 1 . Voltage dropping resistor R 21 preferably has a value of approximately 15 Kohms. Diode 022 is preferably model number of IN4148. Capacitor C 21 preferably has a value of approximately 0.22 uF. A pair of nuisance tripping resistors R 22 and R 23 preferably have a value of approximately 330 ohms. Resistor R 22 is connected in parallel with capacitor C 21 and protection diode D 22 , with one of its terminals connected to gate 25 of first rectifier SCR 1 . In use, resistor R 22 serves to reduce the likelihood of nuisance tripping in rectifiers SCR 1 and diode bridge 1013 .
[0039] An indicator circuit 213 is included connecting power line L to neutral line N at a location between sheath S 1 and circuit breaker 13 . Indicator circuit 213 comprises a light emitting diode (LED) D 25 , a current limiting resistor R 24 and a protection diode D 26 which are connected in Series. Preferably, current limiting resistor R 24 has a value of approximately 33 Kohms and protection diode D 26 has a model number of IN4004. In use, indicator circuit 213 serves to provide a visual indication (i.e., a light) when power is being applied to the load.
[0040] A test circuit 215 is included in safety circuit 1011 , test circuit 215 connecting power line L (at a location between sheath S 1 and circuit breaker 13 ) to R 21 . Test circuit 215 comprises a test switch TEST and a resistor R 25 which are connected in series. Preferably, resistor R 25 has a value of approximately 33 Kohms. In use, test circuit 215 allows the user to test whether safety circuit 1011 is operating properly.
[0041] In use, safety circuit 1011 functions in the following manner. In the absence of arcing conditions, switches K 1 and K 2 are disposed in their normally-closed positions, thereby enabling AC power to pass from the power source to the load through power and neutral lines L and N. Upon the presence of an arcing condition between power line L and metal sheath S, leakage voltage travels from metal sheath S and passes through resistor R 21 , resistor R 21 dropping the leakage voltage to an acceptable level.
[0042] Diode bridge 1013 in safety circuit 1011 acts to detect the presence of an arcing condition between neutral line N and metal sheath S 1 and to switch solenoid SOL from its de-energized state to its energized state upon detecting: the presence of the arcing condition between neutral line N and metal sheath S 1 .
[0043] A first silicon controlled rectifier SCR 1 acts to detect the presence of an arcing condition between the power line L and the metal sheath S 1 and to switch solenoid SOL from its de-energized state to its energized state upon detecting the presence of the arcing condition between the power line L and the metal sheath S 1 .
[0044] It should be noted that safety circuit 1011 differs from conventional electrical safety devices in that fireguard 1011 does not comprise a differential transformer rendering the fireguard circuit 1011 more compact in size and less expensive to manufacture than conventional electrical safety devices which utilize a differential transformer.
[0045] Referring now FIG. 2 , there is shown a second embodiment of a safety circuit constructed according to the teachings of the present invention, the safety circuit being represented generally by reference numeral 1111 . Safety circuit 1111 is identical in all respects with safety circuit 1011 with one notable exception: the power connections for solenoid SOL and the sensing circuitry are derived from the output side the load) rather than from the input side (i.e., the power soure). Specifically, second end 19 of winding 15 for solenoid SOL is connected to power line L at a location between sheath S 1 and circuit breaker 13 . In addition, anode 1023 of diode D 93 and cathode 1029 of diode D 94 are connected to neutral line N at a location between sheath S 1 and circuit. breaker 13 .
[0046] Referring now FIG. 3 , there is shown a third embodiment of a safety circuit constructed according to the teachings of the present invention, the safety circuit being represented generally by reference numeral 1211 Safety circuit 1211 is substantially similar in construction to safety circuit 1011 . The principal distinction between safety circuit 1211 and safety circuit 1011 is that, in safety circuit 1211 , solenoid SOL is connected directly to silicon controlled rectifier SCR 1 whereas, in safety circuit 1011 , solenoid SOL is connected indirectly to silicon controlled rectifier SCR 1 through diode bridge 1013 . Specifically, in safety circuit 1211 , first end 17 of the winding for solenoid SOL is connected to anode 21 of silicon controlled rectifier SCR 1 and second end 19 of the winding for solenoid SOL is connected to cathode 1021 of diode D 92 . Furthermore, diode bridge 1013 is directly connected to the input side (i.e., the power source) of power line L and neutral line N, with anode 1019 of diode D 92 connected to power line L at the power source and anode 1023 of diode D 93 connected to neutral line N at the power source.
[0047] Referring now FIG. 4 , there is shown a fourth embodiment of a safety circuit constructed according to the teachings of the present invention, the fireguard circuit being represented generally by reference numeral 1311 . Safety circuit 1311 is identical in all respects with safety circuit 1211 with one notable exception: the power connections for diode bridge 1013 are derived from the output side (i.e., the load) rather than from the input side (i.e., the power source). Specifically, anode 1019 of diode D 92 is connected to power line L at its output side and anode 1023 of diode D 93 is connected to neutral line N at its output side.
[0048] FIGS. 5-8 illustrate the external housings used to encase the circuit card assemblies 20 illustrated in FIGS. 9-16 . External Housing 10 includes bottom cover 10 A, a top cover 10 B, and a wire cover 10 C. As illustrated in FIGS. 6-8 , the LCDI of the present invention is adaptable to support a variety of source input prong assemblies including 240 20 A prongs 12 , 240 15 A prongs 14 , and 120 Volt prongs 16 .
[0049] FIG. 9 illustrates a circuit card assembly 20 having a top side 20 A, a bottom side 20 B, a load input section 25 and a source input section 27 . Referring to FIG. 10 and FIG. 14 a Load Input section 25 includes a cavity 30 , formed by sidewalk, 30 A, top wall 30 B, and bottom wall 30 C. Cavity 30 serves as a containment barrier for arcing conditions occurring either between power line L and metal sheath S 1 or between neutral line N and metal sheath S 1 that could result in a fire or other dangerous condition. Referring to FIG. 1-4 , Cavity 30 encases load input conductors terminals L, N, and G, and sheathing S 1 . Cavity 30 can be made from any suitable fire retardant material having material properties with flame ratings in accordance with Underwriters Laboratories (UL) 94 flame rating data. In the preferred embodiment, suitable materials such as phenolic and VALOX manufactured by SAW Corp. are utilized.
[0050] In the preferred embodiment, MOV 50 is mounted on bottom side 20 B on the surface of bottom wall 30 C. Movable contact arms 60 extend from a first load contact end 60 A located within cavity 30 , thru bottom wall 30 C, and extending to a second source contact end 60 B ( FIG. 11 , FIG. 12 ) located at the source input section 27 . A ground conductor 65 extends from a first load contact end 65 A, thin bottom wall 30 C, and extending to a second source contact end 65 B located at the source input section 27 .
[0051] Movable contact arms 60 are resiliently flexible and include at the source input section 27 , an actuating member 70 , and latch 72 to reciprocate second source contact end 60 B. Referring to FIG. 11 , source contact prong assembly 12 includes line and Neutral conductors having an outlet end 12 A and a circuit end 12 B. Actuating member 70 includes a cavity 70 A for isolation and containment of both source contact prong 12 circuit end 12 B and movable contact arm 60 source contact end 60 B. Cavity 70 A provides containment of arcing conditions occurring either between power line L and metal sheath S or between neutral line N and metal sheath S that could result in a fire or other dangerous condition. Referring to Circuits 1 - 4 , cavity 70 A contains switches K 1 and K 2 . Cavity 70 A can be made from any suitable fire retardant material having material properties with flame ratings in accordance with Underwriters Laboratories (UL) 94 flame rating data. In the preferred embodiment, suitable materials such as phenolic and VALOX manufactured by SABIC Corp. are utilized.
[0052] Referring to FIG. 14 , circuit card assembly 20 is fitted in bottom cover 10 A. Bottom cover 10 A includes openings for the passage and securement of source contact prongs 12 thereby ensuring a fixed placement of circuit end 12 B within cavity 70 A, and further ensures the fixed placement of ground conductor 65 . Referring to FIG. 11A , Cavity 70 A includes sidewalls 70 B and a top wall 70 C. When fitted in bottom cover 10 A, top wall 70 C isolates movable contact arm 60 source contact end 60 B from contacting the interior of bottom cover 10 A.
[0053] Referring to FIGS. 15 and 16 , load input cable 80 includes a power line 80 A, a neutral line 80 B, and a metal sheath 80 C line that forms a single metal sheath S 1 which surrounds power line L and neutral line N. Ground line 65 remains electrically isolated from power line 80 A and neutral line 80 B. FIG. 16 further illustrates the removal of wire cover 10 C for easy access and quick connection of load types.
[0054] The embodiments shown of the present invention are intended to be merely exemplary and those skilled in the art shall be able to make numerous variations and modifications to it without departing from the spirit of the present invention. All such variations and modifications are intended to be within the scope of the present invention as defined in the appended claims. | A leakage current detection and interruption (LCDI) device, for use as a safety device for a cable connecting, a power source with a load. The LCDI having a safety circuit that senses the presence of an arcing condition between one of the conducting lines and a metal sheath, and in response thereto, opens at least one of the conducting lines between the power supply and the load. The structure of the LCDI circuit card assembly incorporates a load input cavity having fire retardant materials surrounding the load input terminals, and further includes a contact actuator which encases the switch or contact arm at the source input section of the LCDI. | 7 |
FIELD OF THE INVENTION
[0001] This invention relates to a diagnostic method for an infertility condition giving rise to reduced ability to have offspring and to a method of treating such a condition.
BACKGROUND OF THE INVENTION
[0002] An inability or reduced ability to have children can cause great personal distress and has a high attendant social cost, particularly in terms of the cost of medical intervention. A large proportion of couples fall into this category. In the USA, for example, it is said that some 10-15% of couples of reproductive age are unable to have children, whereas in the United Kingdom this is 14%. In 1995 it was calculated that 5.1 million women had impaired fertility in the USA alone, with this figure projected to increase to 5.9 million by the year 2020 (56). In the US, the cost of a pregnancy conceived by IVF varies between US$66.000 for the first cycle to US$114.000 by the sixth cycle (60).
[0003] In the context of this patent an infertility condition is to be understood to relate not only the capacity to conceive but also to miscarriage, spontaneous abortion or other pregnancy related conditions, such as pre-eclampsia, and includes sub fertility.
[0004] Recent studies have revealed that a major proportion of infertile couples are childless because of a higher than normal rate of early embryonic loss (70% miscarriage v. 21% miscarriage in fertile controls, 57), rather than an inability to conceive. These findings have initiated a search for reasons for the increased rate of early embryonic loss in infertile couples, as well as potential therapies to avert such losses.
[0005] In the last 20 years or so some hope has been held out to infertile couples with the development of in vitro fertilisation (IVF) techniques. These IVF techniques generally take the form of stimulating the female to ovulate, contacting collected ova with sperm in vitro and introducing fertilised ova into the uterus. Multiple variations of this general process also exist. Despite considerable research and technical advances in the IVF field the rate of successful pregnancy following IVF treatment is still quite low and is in the order of 15 to 25% per cycle.
[0006] Undertaking an IVF program often causes great anguish, especially when there is no resultant successful pregnancy. It is presently believed that the poor success rate in IVF treatment is due to an extraordinarily high rate of early embryonic loss (58, 59), possibly related to the patient's impaired reproductive state or the IVF process itself.
[0007] The low efficacy of IVF, together with its high cost and the associated psychological trauma from repeated treatment failures makes it desirable that alternative approaches to the problem of infertility are sought. Current methods of increasing pregnancy rates during IVF treatment include placing multiple embryos (2-5) into the uterine cavity, but this is not always effective since uterine receptivity is believed to be at fault at least as commonly as embryonic viability. Furthermore, the ensuing high rates of multiple pregnancy are associated with an increased maternal risk of pre-eclampsia, haemorrhage and operative delivery, and fetal risks including pre-term delivery with the attendant possibility of physical and mental handicap.
[0008] Similarly, early pregnancy loss is a major constraint in breeding programs for livestock and rare or threatened species. Embryonic mortality during the pre- and per-implantation period is viewed as the major reason for poor pregnancy outcome when assisted reproductive technologies such as artificial insemination are used. Even following natural mating, variability in litter size and in the viability of offspring arc additional limitations with serious economic implications.
[0009] The reasons for increased rates of early embryonic loss following natural and assisted conception remain unknown. Chromosomal studies on miscarried embryos have confirmed that at least half of these embryos are genetically normal (61). Normal embryos appear to be lost primarily because the environment provided by the maternal tract during pre-implantation development or at the time of implantation into the endometrium is insufficient to nurture their growth and development. Embryos may lose viability or developmental potential if the maternal tract milieu comprises inappropriate or insufficient nutrients or peptide growth factors. Moreover, a primary determinant of uterine receptivity is provided by the maternal immune response to the conceptus, which is perceived as foreign or semi-allogeneic due to expression of both maternal and paternal antigens.
[0010] Medawar originally hypothesised that maternal immune accommodation of the semi-allogeneic conceptus may be facilitated by immunological tolerance to paternal transplantation antigens (major histocompatibility [MHC] antigens) (70). This hypothesis lost favour when it was found that pregnancy does not permanently alter the capacity of mice to reject paternal skin grafts (5, 46). However, the concept of transient hyporesponsiveness to paternal MHC antigens (46) is now receiving renewed attention, as a recent study by Tafuri et al (31) has provided clear evidence to show that during murine pregnancy, T-lymphocytes reactive with paternal class I MHC become ‘anergic’, or unable to recognise antigen due to internalisation of T-cell receptors. This anergic state conferred ‘tolerance’ to paternal MHC antigen-expressing tumor cells, and was functionally operative from as early as implantation (day 4 of pregnancy) and lasted until shortly after parturition when lymphocytes regained their reactivity. The data support the hypothesis that a permissive maternal immune response to other antigens expressed on the embryo, or the fetal-placental unit (hereafter referred to as the conceptus) may similarly be due to induction of a tolerant immune response specific to those antigens.
[0011] Just precisely what is responsible for inducing this tolerance of paternal MHC antigens and other conceptus antigens has heretofore been unclear. Additionally the nature of the tolerance was unclear.
[0012] The term tolerance in the context of this invention is taken to mean inhibition of the potentially destructive cell-mediated immune response against conceptus antigens, and/or inhibition of synthesis of conceptus antigen-reactive immunoglobulin of complement-fixing isotypes (for example the ‘Th1’ compartment of the immune response). This tolerance may or may not be associated with induction of synthesis of non-destructive, conceptus antigen-reactive immunoglobulin of the non-complement-fixing isotypes and subclasses (for example the ‘Th2’ compartment of the immune response). The term tolerance should be taken to encompass T cell anergy and other permanent or transient forms of hypo-responsiveness or suppression of the maternal Th1 compartment
[0013] Tafuri et al (31) have shown that paternal antigen-specific tolerance is active by the onset of blastocyst implantation on day 4 of pregnancy in mice. The pre-implantation embryo is a poor antigenic stimulus since it usually comprises fewer than 100 cells and is enveloped by a protective coat (zona pelluicida) until just before implantation. Semen however is richly endowed with paternal antigens present on and within sperm, somatic cells and the seminal plasma itself, and comprises an effective priming inoculum for many paternal antigens (5) known to be shared by the conceptus. Up until now seminal plasma has been conventionally thought to function primarily as a transport and survival medium for spermatozoa traversing the female reproductive tract (21). The recent studies described by the inventors in this specification have highlighted a hitherto unappreciated role for this fluid in interacting with maternal cells to induce a cascade of cellular and molecular events which ultimately lead to maternal immune tolerance to paternal antigens present in semen and shared by the conceptus, thereby abrogating immune rejection during implantation.
[0014] Ejaculation during coitus provokes a leukocyte infiltrate at the site of semen deposition termed the ‘leukocytic cell reaction’ in a variety of mammalian species, including man (1). In mice, the cascade of cellular and molecular changes initiated by the introduction of semen into the uterus, in many respects, resembles a classic inflammatory response. Within hours after mating, a striking influx and activation of macrophages, neutrophils, and eosinophils occurs in the endometrial stroma (2-4), in association with upregulated expression of major histocompatibility complex (MHC) class II and CD86 antigens by endometrial dendritic cells, followed by enlargement of draining lymph nodes (5.6). This inflammatory response is transient and fully dissipates by the time of embryo implantation on day 4 of pregnancy (2-4), when leukocytes persisting in the endometrium are predominantly macrophages with an immunosuppressive phenotype (7).
[0015] The temporal changes in trafficking and phenotypic behaviour of endometrial leukocytes during the period between mating and implantation are likely to be orchestrated principally by cytokines emanating from steroid hormone regulated epithelial cells lining the endometrial surface and comprising the endometrial glands (8). Of particular importance are granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-(IL)-6, the synthesis of which are upregulated at least 20-fold and 200-fold respectively in estrogen primed epithelial cells following induction by specific proteinaceous factors in seminal plasma (8.9) known to be derived from the seminal vesicle gland (10). Previous studies have implicated the surge in epithelial GM-CSF release as a key mediator in the post-mating inflammatory response since injection of recombinant GM-CSF into the estrous uterus is sufficient to produce cellular changes resembling those seen following natural mating (11). The inventors have found, using GM-CSF deficient mice, that the chemotactic activity of GM-CSF is likely to be compensated or augmented by an array of chemokines, the expression of which are transiently upregulated after mating (12), and cytokines synthesised by activated endometrial macrophages including IL-1 and tumour necrosis factor-α (TNF-α)(4).
[0016] The present inventors have investigated the nature of the seminal factor which acts to stimulate GM-CSF release from the uterine epithelium. Previous experiments have shown that the increase in uterine GM-CSF content is neither the result of introduction of GM-CSF contained within the ejaculate, nor a consequence of a neuroendocrine response to cervical stimulation, and is independent both of the presence of sperm in the ejaculate and MHC disparity between the male and female (8). A mechanism involving induction of GM-CSF mRNA synthesis in epithelial cells by proteinaceous factors derived from the seminal vesicle was suggested by experiments showing that seminal vesicle-deficient (SV−) males did not evoke GM-CSF release or a post-mating inflammation-like response in females, and that trypsin-sensitive, high molecular weight material extracted from the seminal vesicle could upregulate GM-CSF release from uterine epithelial cells in vitro (10).
[0017] It has, however, not been clear from previously published work that this inflammatory response is related to the induction of tolerance by the mother to the conceptus, or alternatively whether the inflammatory response has a role in enhancing the immune system to combat the influx of foreign matter such as potential pathogenic bacteria is not clear. Nor is there any indication as to what the trigger for the induction of tolerance is or indeed that tolerance is mediated by semen.
[0018] One known relevant prior art document is U.S. Pat. No. 5,395,825 by Feinberg. This specification discloses a finding that suggests that elevated TGFβ in the female reproductive tract can facilitate production of fibronectin, a protein hypothesised to assist implantation by promoting adhesion of the embryo to the endometrial surface. The half life of TGFβ is only a few minutes and its effect on fibronectin is very short term. Therefore the administration of TGFβ in the above method can only be contemplated to assist implantation if delivered at precisely the time at which the pre-implantation embryo arrives in the uterine cavity. The present invention does not require such temporal precision in TGFβ delivery, nor does it purport that the effect of TGFβ is mediated through fibronectin.
SUMMARY OF THE INVENTION
[0019] The inventors have identified TGF-β as a principal immune regulatory molecule within seminal plasma. TGMβ produced in the latent form in the seminal vesicle gland is activated within the female reproductive tract where it acts to induce GM-CSF synthesis in uterine epithelial cells, thereby initiating the post-coital inflammatory response.
[0020] Additionally the inventors have shown that TGFβ, when administered to the female reproductive tract together with sperm or semen, can elicit tolerance towards male antigens, including paternal MHC class I antigens. This state of tolerance is evidenced by inhibition of Th1-type immune responses to paternal antigens, including delayed-type hypersensitivity (DTH) responses primed by a previous injection with sperm, production of complement-fixing isotypes of immunoglobulin specific for sperm, and cell-mediated immune rejection of tumor cells bearing the same MHC class I antigens as contained in the priming sperm inoculum. It is proposed that this tolerance might be achieved by exposure of the female to TGFβ either with or without male antigen.
[0021] The significance of this is that it is highly likely that certain infertility conditions will be related to the incapacity to produce tolerance to antigens of the male and/or to provide a suitable cytokine environment for growth and development of the pre-implantation embryo, as a result of either a lack of TGFβ in the seminal fluid of the male, an incapacity of the female to process the TGFβ from an inactive to an active form, or an absence or low levels of paternal antigens in the ejaculate. In some instances infertility may be due to the inability of the female to respond to TGFβ, in which case direct application of molecules induced by TGFβ, such as GM-CSF, may be warranted.
[0022] The TGF-β 1 content of murine seminal vesicle secretions, like that of human seminal plasma (22), was found to be extraordinarily high and second only to that reported for platelet distillate (23). In mammalian species the TGF-β family comprises at least three closely related polypeptides, TGF-β 1 , -β 2 and -β 3 (24), which exhibit 70-80% sequence homology and share many biological actions. TGFβ, is the dominant TGFβ isotype responsible for increasing murine uterine GM-CSF output, since TGFβ 1 -specific neutralising antibody is now found to have the ability to block 85% of seminal vesicle GM-CSF stimulating activity ( FIG. 2 ). Other members of the TGFβ superfamily, such as TGFβ 2 and activin, have also now been identified as capable of eliciting an increase in uterine GM-CSF output ( FIG. 4 ). These additional members of the TGF-0 family, complexed with other carrier proteins such as the 250-300 kDa binding protein betaglycan (25) may account for the higher molecular weight activity present in murine seminal vesicle fluid and human seminal plasma (22).
[0023] The synthesis of TGFβ as a latent complex is believed to have a stabilising effect (26) and focus its activity at the target site by binding to extracellular matrix (27). Evidence for a uterine mechanism for activation of latent TGF-β was provided by the present finding that in contrast to activity in the seminal vesicle, the majority of the TGFβ 1 found in the uterine luminal fluid after mating was in the active form ( FIG. 5 ). Plasmin or other proteolytic enzymes derived from uterine cells or the male accessory glands (28, 29, 47) may contribute to the activation of TGFβ after ejaculation.
[0024] The proposal that components of the ejaculate can indirectly contribute to pregnancy success is supported by experiments in accessory gland-deficient mice (36, 37) and the finding that poor pregnancy outcome and dysregulated fetal and/or placental growth after embryo transfer or during first pregnancy in various livestock species (38-40) can be partially ameliorated by prior exposure to semen (41, 42). Likewise, studies in humans now clearly identify lack of exposure to semen due to limited sexual experience, use of barrier methods of contraception, or in IVF pregnancies with increased risk of implantation failure, spontaneous abortion and pre-eclampsia (43-45).
[0025] In a broad form the invention could be said to reside in a method of treating an infertility condition in a human or mammal by exposure of the prospective mother to TGFβ or an effective derivative or analog thereof before attempted conception to elicit a transient hyporesponsive immune reaction to one or more antigen of a prospective father to thereby alleviate symptoms of the infertility condition.
[0026] In another broad form the invention could be said to reside in a method of treating an infertility condition in a human or mammal by exposure of a prospective mother to one or more antigens of a prospective father and to TGFβ or an effective derivative or analog thereof before attempted conception to elicit a transient hyporesponsive immune reaction to said one or more antigen to thereby alleviate symptoms of the infertility condition.
[0027] Preferably a mucosal surface of the prospective mother is exposed to the antigen, and more preferably the mucosal surface is the genital mucosal surface, however, it is feasible that exposure at other mucosal surfaces can give rise to the transient paternal antigen tolerance. There are two basic reasons that this might be the case, firstly it is known that tolerance to external antigens can be elicited at mucosal surfaces, thus it is known that women that are exposed to seminal fluid orally show evidence of reduced pre eclampsia effects to MHC antigens of the male partner (48). Thus the exposure could be oral, respiratory, gastrointestinal or genital. For example the surface antigen and TGFβ may be presented as an oral or nasal spray, or as a rectal or vaginal gel. Such a gel might for example be a gel such as used in the vaginal gel sold under the brand name PROSTIN (Upjohn Pty Ltd). Alternatively it might be desired to take the TGFβ and the surface antigen in a form that gives exposure to the small and perhaps large intestines, such as perhaps contained in a gelatin capsule.
[0028] Whilst a mucosal exposure may be preferred because it is likely to give rise to a transient tolerant immune reaction, it may also be feasible to provide for another route of exposure. Thus the surface antigen and TGFβ may be injected for systemic contact.
[0029] It may be desirable to deliver the TGFβ and the antigen together, for example where the two are combined in a gel, or spray, alternatively, it might be desirable to provide a source of TGFβ at the mucosal surface of interest, which might be the genital tract, and the antigen could subsequently be deposited onto the mucosal surface. It is also not yet clear whether the TGFβ needs to be present at the same time as the antigen is present, although it is believed to be preferable, however, it is proposed that it may be possible to have a delay between the delivery of the TGFβ and the surface antigen. Thus an alternative would be to deposit the antigen first perhaps as an ejaculate and then deliver the TGFβ as a pessary after intercourse.
[0030] The nature of the relevant surface antigens is not entirely clear, but will presumably be those that are particularly antigenic and prominent either on the sperm, or on the conceptus. The most likely candidates are MHC antigens, and more preferably MHC class I. The most efficient manner of presenting these antigens is in the form that they are naturally present—on any appropriate cell of the intended male parent that expresses them and those cells would include sperm cells and may include leukocytes. The antigens may also be presented in biological fluids such as seminal plasma which is known to carry certain male antigens (49). This use or cells other than sperm cells will be pertinent where the sperm count of the prospective father is somewhat low. The use of cells other than sperm cells may be preferred where a non-genital route is used. Alternatively the antigens may be presented in purified or semi-purified form, which may or may not be presented on inert or adjuvant carriers, thus for example it may be presented in the carriers known as ISCOMS. This latter approach however is likely to be more technically complex and expensive. It is additionally possible that the antigens may be encoded within sperm cells in the form of mRNA (or other nucleic acid) and this RNA message is then expressed by maternal genital tract cells. It may be that TGFβ therefore plays a role in promoting the events leading to presentation of paternal antigen to maternal lymphocytes through activating genital tract antigen presenting cells to take up and translate sperm mRNA.
[0031] The level of TGF β may be varied, and will vary depending upon which species is being treated. For humans the level of TGFβ will preferably be greater than 50 ng/ml with a total dose of 150 ng/ml and more preferably at a concentration of between 100 and 400 ng/ml with a total dose of between 100 to 2000 ng. The level of TGFβ in normal male semen is in the order of 200 ng/ml. This level can be judged empirically when assessing other animals, and thus for horses or cattle the preferred level is expected to be in the order of 100 ng/ml. These levels may vary if the TGFβ is supplied in a slow release depot, perhaps as a patch or as a gel or latent TGFβ complex.
[0032] The level of exposure to surface antigens may vary, in a preferred form the exposure will be to the prospective mother's genital tract in the form of the prospective father's ejaculate, and the level of exposure will be determined by the cell count and antigenic density on the surface of such cells. Where cells are administered other than in the above manner, a similar number of cells might be used, however, the most effective manner may be determined empirically. It is though that an exposure of leukocytes in the order of 10 7 -10 9 cells might be the appropriate level of exposure to a mucosal surface.
[0033] The specificity of TGFβ to be co-administered with the male antigens is at present not entirely clear, and because TGFβ 1 is thought to be responsible whereas TGFβ 2,3 are less important, it is more likely that TGFβ 1 is to be used. It will however also be understood that various modification might be made to TGFβ 1 or indeed TGFβ2, or TGFβ 3 which could be effective in eliciting an effective transient tolerant immune reaction either separately or in combination with another agent. Such modified TGFβ's might include substitution, deletion or addition mutants, and might include peptide fragments, which may or may not be incorporated into another protein to make a recombinant protein. Alternatively other members of the TGFβ superfamily may also be used or used as a starting point to developing an analog of the TGFβ activity, one such member is known as activin.
[0034] Where unmodified TGFβ is used it will preferably be administered as TGFβ 1 . The TGFβ 1 may be administered in its active form, however, where the prospective mother is capable of activating TGFβ 1 it may also be administered in its precursor form. An alternative “delivery” option would be natural TGFβ such as in the form of platelets. Thus instead of purified TGFβ a preparation of platelets or other source rich in natural TGFβ, such as milk or colostrum, may be used.
[0035] The exposure is preferably a multiple exposure. The multiple exposure is preferably performed over a period of at least three months, with the mucosal surface being exposed to TGFβ during each exposure to the prospective father's antigens. This period of time could however be somewhat reduced, and it may be possible to achieve improvement with one exposure but as a minimum it is anticipated that exposure would be at least one week before conception is attempted. It may also be preferred that non-barrier contraceptive measures be taken prior to the planned conception, where the antigens are associated with sperm cells and these are administered to the genital tract, so that there is some certainty of a period of exposure to the prospective father's antigens before conception. This is particularly the case where the fertility condition is of the type where conception takes place but either miscarriage, spontaneous abortion or pre-eclampsia occurs after conception.
[0036] It is also envisaged that the administration of TGFβ in the presence or absence of the at least one surface antigen may need to continue past the prospective date of conception perhaps for the first 12 weeks of pregnancy.
[0037] In an alternative form the invention could be said to reside in a method of diagnosing an infertility condition in males by testing the level of TGFβ in seminal fluid.
[0038] Greater than 70% of the TGF-β 1 in seminal vesicles exists in the latent form. The infertility condition might therefore not be due to a lack of TGFβ in the semen of the male partner but it may be that the female cannot process the inactive form of the TGFβ. The invention could therefore also be said to include the method of exposing inactive form of TGFβ to the genital tract of a female and testing for her capacity to convert the inactive form of TGFβ to active TGFβ. If this is found to be the case, the method of treating the fertility condition will include administration of active TGFβ, or alternatively a compound capable of activating TGFβ can be administered, such as plasmin, so as to increase the level of active TGFβ.
[0039] In a preferred form the method of treating infertility will first include the step or diagnosing or testing whether the male has adequate levels of TGFβ or the female has the capacity to activate TGFβ, or alternatively whether anti-sperm antibodies exist.
[0040] The use of the present invention may be used in conjunction with IVF treatment, whereby the transient tolerant immune response is elicited before transfer of the conceptus or gametes is attempted. It is expected however that where the infertility condition is caused as a result of reduced TGFβ level in semen, or capacity to activate TGFβ, it is likely that the trauma of IVF treatment may not be needed and that a ‘natural’ conception may be possible in its place.
[0041] It will be understood that this invention is not necessarily limited to humans, but may also extend to treatment of other mammals including livestock species.
[0042] Some specific disorders or procedures that may benefit from the present invention are now discussed to some degree.
[0043] Recurrent miscarriage. It is known that approximately 2-5% of couples are involuntarily childless due to recurrent miscarriage. The aetiology of recurrent miscarriage is complex, but in the vast majority of cases no chromosomal, hormonal nor anatomical defect can be found and an immunological lesion is implicated. A variety of therapies which attempt to modify the mother's immune response to the semi-allogeneic conceptus have been trialed with variable success. The predominant therapeutic approach over the past 20 years has been to inject women with paternal leucocytes in the hope of achieving ‘tolerance’ to paternal antigens. This therapy has had limited success with a meta-analysis of 15 trials concluding that paternal leucocyte immunisation can increase pregnancy rates by 8-10% (51).
[0044] Coulam & Stern (52) have administered seminal plasma from a pooled donor source to the genital tract of women with recurrent miscarriage and were able to produce a non-statistically significant increase in live birth rates (60% v 48%, p=0.29 n=86). This treatment differs significantly from a preferred therapeutic regime in that seminal plasma was administered in the absence of paternal antigen. It is not surprising that the success of this therapy was limited, since no paternal antigen was administered.
[0045] The data supporting the present invention provide encouraging results which indicate that TGFβ may be a beneficial treatment for recurrent miscarriage because of its potent immune modulating capacity. It is expected that administration of sperm in combination with TGFβ will help produce a tolerant or ‘nurturing’ immune response to a future conceptus which would share some of the same MHC class I or other antigens.
[0046] Adjunct to IVF treatment. It is currently believed that premenstrual pregnancy wastage produces a significant negative contribution to IVF success rates. One theory for this increased early pregnancy loss is that IVF is an ‘unnatural’ process that separates the act of intercourse from conception. This would mean that IVF recipients may not be exposed to seminal plasma and it's associated antigens early in pregnancy. Several animal studies and human investigations, including the randomised control trial described herein, have suggested that exposure of the female genital tract to semen at the initiation of a pregnancy, as well as prior to a pregnancy, is beneficial to subsequent pregnancy outcome. It is proposed that there will be some benefit derived from giving women exogenous TGFβ in combination with partner's sperm/leucocytes at or near the time of embryo transfer, especially if the partner's seminal plasma TGFβ content is low or sperm numbers are low.
[0047] Anti-sperm antibody therapy. A significant proportion of infertility is due to the presence of anti-sperm antibodies in either the male or female partner (53). Seminal plasma has been shown to suppress the formation of anti-sperm antibodies in the female serum and genital tract secretions of the mouse. One of the active agents within seminal plasma responsible for suppressing maternal production of potentially damaging, complement-fixing isotypes or subclasses of immunoglobulin specific for sperm antigens has been identified as TGFβ. It is expected that the present invention may, in at least some instances, block anti-sperm antibody formation. The relationship between maternal anti-sperm antibody formation in women and their partner's seminal plasma TGFβ concentration will be investigated to confirm this. Current therapies for anti-sperm antibodies are not sufficiently effective (for example oral steroids or the prolonged use of barrier contraception) or require expensive assisted reproduction therapy. It is proposed that administration of a TGFβ-containing pessary following intercourse will abrogate this anti-sperm antibody response and enable natural pregnancy to ensue.
[0048] Pre-eclampsia and IUGR prophylaxis. Pre-eclampsia and some forms of intra-uterine growth restriction (IUGR) are believed to be an immunological disorder due to ‘shallow’ placentation resulting from a damaging, Th1-type immune attack on the invasive trophoblast. There is epidemiological evidence showing that repeated exposure of a woman to her partner's antigens through intercourse in the absence of barrier contraception decreases her chances of developing pre-eclampsia in a subsequent pregnancy to that partner (54, 55). This may be brought about by the generation of maternal ‘tolerance’ towards paternal antigens as a consequence of repeated exposure at intercourse, which facilitates placental growth and invasion of the maternal decidua. Some women have a propensity to develop pre-eclampsia or to suffer fetal growth restriction every time they become pregnant. This may be due to inadequate TGFβ content of their partner's semen, or an inability to process latent TGFβ into a biologically active form.
[0049] Priming with partner's antigens in combination with TGFβ before conception and perhaps until 3 months of pregnancy, by which time placental invasion is complete, may help prevent the development of pre-eclampsia and IUGR in these high risk women.
[0050] Prospective analysis of stud animal fertility in livestock breeding industries. Variability in the productivity of stud males is a major constraint in pig, cattle, sheep and other livestock breeding programs. In many species there are substantial differences between studs, particularly in the pre-implantation mortality of embryos sired, even within a given herd. Currently, reliable estimation of the fertility and fecundity of a stud male is only possible after documentation of the outcome of multiple pregnancies. Measurement of the TGFβ content of seminal plasma of potential studs, for example by simple enzyme-linked immunosorbent assay, is likely to be an effective tool in livestock breeding management. Such measurements may need to be taken over the course of some weeks and could be made in conjunction with measurements of other factors known to inhibit the action of TGFβ, such as interferon-γ.
[0051] Optimisation of pregnancy outcome in livestock breeding industries. A primary determinant of the productivity of livestock breeding programs, particularly in species such as the pig where litters are large, is variability in the litter size and weight of offspring. As detailed above, these parameters are believed to be influenced largely by the extent to which the mother's immune response is ‘tolerised’ to paternal antigens shared by the conceptus. Pregnancy outcome is often further compromised where the pregnancy is initiated by artificial insemination, particularly when artificial semen extenders, as opposed to seminal plasma, are employed as the carrier. Since the frequency of mating between breeding females and studs is often limited, and variability in the seminal plasma TGFβ content between males is probable, pregnancy outcome is likely to benefit from exogenous administration of TGFβ in many livestock species. TGFβ could be given prior to, or at the initiation of a naturally-sired pregnancy, or at the time of artificial insemination.
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] FIG. 1 . Sephacryl S-400 size exclusion chromatography of (A) GM-CSF stimulating activity and (B) TGF-β immunoactivity in murine seminal vesicle fluid. In A, uterine epithelial cells from estrous mice were incubated for 16 h with untreated (o, =active TGF-β) or acid activated (●=active+latent TGF-β) fractions of seminal vesicle fluid. After a further 24 h culture, the GM-CSF content of supernatant % was determined by FD 5112 bioassay. Values are means of triplicate cultures and the horizontal dashed line is GM-CSF production by epithelial cells cultured with DMEM-FCS alone. In B, the content of immunoactive TGF-β 1 (●) in fractions of seminal vesicle fluid was determined by ELISA. TOF-β bioactivity was detected by Mv-1-Lu cell bioassay. Fractions depicted by the hatched area contained >300 pg/ml, and other fractions contained <50 pg/ml. Data is representative of similar results obtained from three replicate experiments.
[0053] FIG. 2 . The effect of neutralising antibodies specific for TGF-β 1,2,3 and TGF-β 1 on GM-CSF stimulating activity in murine seminal vesicle fluid. Uterine epithelial cells from estrous mice were incubated for 16 h with 2% crude seminal vesicle fluid or DMEM-FCS alone, in the presence or absence of mouse anti-bovine TGF-β 1,2,3 (20 μg/ml) or chicken anti-bovine TGF-01 (10 μg/ml). After a further 24 h culture, the GM-CSF content of supernatants was determined by FD 5/12 bioassay. Values are mean±SD of triplicate cultures. Data is representative of similar results obtained from three replicate experiments.
[0054] FIG. 3 . The effect of TGF-β 1 on GM-CSF production by uterine epithelial cells in vitro. Uterine epithelial cells from estrous mice were incubated for 16 h with 0.08-80 ng/ml recombinant human TGF-β 1 . After a further 24 h culture, the GM-CSF content of supernatants was determined by FD 5/12 bioassay. The mean±SD of triplicate wells is shown. Data is representative of similar results obtained from four replicate experiments.
[0055] FIG. 4 . The effect of TGF-β 2 , activin and inhibin on GM-CSF production by uterine epithelial cells in vitro. Uterine epithelial cells from estrous mice were incubated for 16 h with 0.05-50 ng/ml recombinant human TGF-β 1 , porcine TGFβ 2 , or human recombinant activin and inhibin. After a further 24 h culture, the GM-CSF content of supernatants was determined by FD 5/12 bioassay. The mean±SD of triplicate wells is shown. Data is representative of similar results obtained from two replicate experiments.
[0056] FIG. 5 . The effect of seminal composition on the TGF-β 1 content of uterine luminal fluid after mating. TGF-β 1 immunoactivity was determined by ELISA in untreated (o=active TGF-0) or acid activated (●=active+latent TGF-β) uterine luminal fluids collected from estrous mice, or from mice 1 h after mating with intact, vasectomized (vas) or seminal vesicle deficient (SV−) males. Symbols represent data from individual mice and median values for treatment groups are scored. Data were compared by Kruskal-Wallis one way ANOVA and Mann Whitney Rank Sum test. Data sets labelled on the x-axis with different lower case letters denote statistical significance between treatment groups (p<0.01).
[0057] FIG. 6 . The effect of intra-uterine TGF-β 1 on the GM-CSF content of uterine luminal fluid. Fluids were collected 16 h after natural mating with intact males, or after administration of 0.4-40 ng recombinant human TGF-β 1 in 50 μl PBS/1% BSA, or vehicle only, to the uterine luminal cavity of estrous mice. Symbols represent data from individual mice and median values for treatment groups are scored. Data were compared by Kruskal-Wallis one way ANOVA and Mann Whitney Rank Sum test. Data sets labelled on the x-axis with different lower case letters denote statistical significance between treatment groups (p<0.01).
[0058] FIG. 7 . The effect of rTGFβ 1 and semen on GM-CSF output from human reproductive tract epithelial cells. The GM-CSF content of culture supernatants collected from (A) cervical keratinocytes and (B) endometrial cell cultures was determined by commercial ELISA. 12 hours after the addition of dilute whole semen (10% vol/vol) or 10 ng/ml rTGFβ 1 .
[0059] FIG. 8 . The effect of intra-uterine priming with sperm and TGFβ on induction of Th1-type immunity. Balb/c F1 female mice were immunised by intra-uterine infusion with CBA sperm in the presence of absence of 10 ng rTGFβ. Additional groups of uterine-ligated mice were mated naturally with CBA males, or were given sub-cutaneous immunisations with sperm in complete Freund's adjuvant. Ten days later mice were assessed for DTH Lo sperm antigens, or serum content of anti-sperm IgG2b immunoglobulin. Data was compared by Kruskal-Wallis one way ANOVA, followed by Mann Whitney rank sum test with different superscripts indicating significant differences (p<0.05).
[0060] FIG. 9 . Effect of prior immunisation with sperm and TGFβ on fetal and placental weights during subsequent pregnancy in mice. Balb/F1 female mice were immunised by intra-uterine infusion with CBA sperm in the presence (±rTGFβ 1 ), and were mated naturally with CBA males 2 weeks later. Females were sacrificed on day 17 of pregnancy and fetal (A) and placental weights (B) were determined. Comparisons between groups were made according to the number of viable fetal-placental units per uterine horn, by Kruskal Wallis one-way ANOVA followed by Mann Whitney rank sum test (p<0.05).
DETAILED DESCRIPTION OF THE INVENTION
[0000] Materials and Methods
[0000] Cell Lines, Media, Cytokines and Antibodies.
[0061] RPMI-1640 and low glucose Dulbecco's modified Eagle' medium (DMEM, GIBCO) were supplemented with 10% fetal calf serum (CSL), 20 mM HEPES pH 7.2, 5×10 −5 M β-mercaptoethanol, 2 mM L-glutamine and antibiotics (RPMI-FCS and DMEM-FCS). FD5/12 cells (14), 3T3 fibroblasts, and JR-5 Balb/c fibrosarcoma cells were cultured in RPMI-FCS and mink lung cells [Mv-1-Lu, CCL-64] and uterine epithelial cells were cultured in DMEM-FCS. Human ectocervical cells were cultured in 70% DMEM, 20% Hams F-12 (Gibco), 9% FCS, 1% Neutridoma-SP (Boehringer Mannheim), and 0.4 μg/ml hydrocortisone (Upjohn. Rydalmere, NSW) (ECM-FCS), and human endometrial cells were cultured in DMEM-FCS.
[0062] Recombinant human (rh)TGF-β 1 was from R&D Systems, recombinant murine GM-CSF was provided by N. Nicola, The Walter and Eliza Hall Institute for Cancer Research, and recombinant human activin and inhibin were provided by J. Findlay, Prince Henry's Institute for Medical Research. Monoclonal antibodies (mAb) used for immunohistochemistry were anti-CD45 (TIB 122), anti-Mac-1 (CD11b. TIB 128), anti-MHC class II (Ia antigen. TIB 120; all from ATCC). F4/80 (15), and RB6-6C5 (16). Mouse anti-bovine TGF-β 1,2,3 mAb (which neutralizes all three mammalian TGF-β isoforms) was from Genzyme (Cambridge. MA) and chicken anti-bovine TGF-β1 mAb (neutralizes TGF-β1, <2% cross reactivity with TGF-β 2 and -β 3 ) was from R & D Systems.
[0063] Mice and Surgical Procedures. Adult (8-12 week) female mice of the [Balb/c X C57B1]F1, Balb/c or Balb/k strains, and adult male mice of the [CBA×C57B1]F1, CBA, or Balb/c strains were obtained from the University of Adelaide Central Animal House and maintained in a minimal security barrier facility on a 12 hour light/12 hour dark cycle with food and water available ad libitum. Females were synchronised into estrus using the Whitten effect (17) and cycle stage was confirmed by analysis of vaginal smears. For natural mating, females were placed 2 per cage with individual males and the day of sighting of a vaginal plug was nominated as day 1 of pregnancy. Male studs used for collection of accessory gland secretions were all of proven fertility and were rested for one week prior to use.
[0064] For intra-uterine injections, uterine horns of estrus females were exteriorised through a dorsal midline excision and injected with 0.2-40 ng rhTGF-β 1 in 50 ml of RPMI/0.1% BSA, or vehicle only, prior to sacrifice of mice 16 hours later for assessment of luminal cytokine content or collection of uterine tissue for immunohistochemistry. Non-surgical administration of sperm/TGFβ 1 to the uterine lumen was achieved by passing a 3 French gauge Tom Cat™ catheter (Sherwood Medical, St. Louis, Mo.) into the uterine lumen (proximal to the point of bifurcation) of restrained females, after visualisation of the cervix with the aid of an auriscope (Heine, Germany), and manual dilation of the cervix with a fine wire. Each uterine catheter was loaded with 50 μl of sperm/TGFβ 1 , which was delivered to the uterine cavity with the aid of a mouth pipette.
[0065] Vasectomised mice were prepared by bilateral ligation of the vas deferens through a transverse incision in the abdomen (Hogan et al., 1986), and seminal vesiculectomised mice were prepared by removal of the seminal vesicles through a transverse incision in the abdomen following ligation and severing of the proximal tubule at the base of the gland. The body wall and skin were sutured and the mice were allowed to recover for at least two weeks prior to mating.
[0066] All surgical procedures were performed under anaesthesia using Avertin [1 mg/ml tribromoethyl alcohol in tertiary amyl alcohol (Sigma) diluted to 2.5% v/v in saline; 15 μl/g body weight injected i.p.].
[0067] Collection of Reproductive Tract Fluids. Seminal vesicle secretions were extruded from intact glands and solubilised in 6 M guanidine HCl (1:4 v/v), then desalted into DMEM using 5 ml Sephadex G-25 desalting columns (Pharmacia) before application to epithelial cell cultures. Prostate and coagulating gland secretions were extracted by homogenisation of intact glands in 0.5 ml of PBS/1% BSA, followed by sedimenation of debris at 5000 g. Uterine luminal fluid was collected 16 h after mating or instillation of rhTGF-β1 into the uterus by flushing each horn with 500 μl of RPMI-FCS. Debris was sedimented at 2000 g and the supernatant stored at −80° C. prior to cytokine assay. In experiments where uterine TGF-β1 was measured, flushings of the right horn were made with 6 M guanidine HCl/0.1% BSA, and desalted into PBS/0.1% BSA prior to cytokine assay. For matings with intact and seminal vesicle deficient males the left horn was flushed with DMEM to enable confirmation that adequate insemination had occurred (>1×10 6 sperm per ml).
[0068] Chromatography. Approximately 1 ml of seminal vesicle fluid in 6 M guanidine HCl was applied to a Sephacryl S-400 column (40 cm×16 mm; Pharmacia) equilibrated in 6 M guanidine HCl/0.05 M Hepes pH 7.4. Fractions of 1 ml were collected, desalted into DMEM and assayed for GM-CSF-stimulating activity. Before addition to uterine culture or TGF-β assay half of each fraction was acid activated as previously described (18).
[0069] Murine uterine epithelial cell cultures. Uterine epithelial cells were prepared as previously described (19) and plated in 1 ml culture wells (Nunc) at 1-2×10 5 cells/ml in 500 μl of DMEM-FCS. After 4 h incubation at 37° C. in 5% CO2 to allow cell adherence, a further 500 μl of desalted seminal vesicle fluid in DMEM-FCS, cytokines in DMEM-FCS, or DMEM-FCS alone, were added. Culture supernatants were collected and replaced with fresh medium at 16 hours, then collected again 24 hours later, at which time adherent cells were quantified as previously described (19). All treatments were performed in duplicate or triplicate.
[0070] Human endometrial cultures. Human endometrial cell cultures were prepared under sterile conditions using a modification of the procedure described by Bentin-Ley (64). Briefly, stromal cells were embedded in a collagen matrix, covered by a thin layer of Matrigel (Collaborative Biomedical Products. Bedford, Mass.), which in turn was over-laid with uterine epithelial cells. Uterine epithelial cell supernatants were collected at 12 hrs (basal), replaced with 400 μl of medium containing either rTGFβ 1 , semen, or fresh culture medium, and supernatants were collected 12 h later. The GM-CSF content of 24 h supernatants were normalised to the GM-CSF content of corresponding 12 h (basal) supernatants.
[0071] Human cervical keratinocytes. Human cervical keratinocytes were cultured using a modification of the technique described by Rheinwald and Green (65). Cervical biopsies were obtained from consenting women undergoing hysterectomy for non-malignant gynaecological indications. All women were pre-menopausal, but no distinction was made regarding stage of menstrual cycle at the time of surgery. The cervical biopsies were placed in ice-cold HBSS for transport to the laboratory, washed twice in antibiotic containing medium, and incubated overnight at 4° C. in DMEM containing 5 U dispase (Boehringer Mannheim). Large sheets of keratinocytes were mechanically stripped from the biopsy using sterile forceps after a subsequent 1 h incubation at room temperature. Disaggregation into single cells was facilitated by incubation in DMEM/0.25% trypsin/0.05% collagenase for 30 minutes at 37° C., and repeated aspiration using a needle and syringe. Keratinocytes were cultured in ECM-FCS, at a density of 1-2×10 −5 cells/ml, over monolayers of murine 3T3 fibroblasts rendered mitogenically inactive by exposure to 4% mitomycin C (Sigma). Keratinocytes were incubated for 5-7 days to enable attachment and displacment of the 3T3 fibroblasts, when the media was replaced with fresh ECM-FCS. Supernatant was collected 12 h later (basal) and replaced with 500 μl of ECM-FCS containing 10 ng of rTGFβ 1 , 10% semen or culture medium only (control), which in turn was collected 12 hrs later. The GM-CSF content of 24 h supernatants were normalised to the GM-CSF content of corresponding 12 h (basal) supernatants.
[0072] Cytokines and Cytokine Assays. GM-CSF was assayed using the GM-CSF dependant cell line FD5/12, essentially as previously described (19). Cell proliferation was determined by the addition of Alamar Blue (Alamar Biosciences) for the last 24 h of the assay or by pulsing with 1 μCi of [ 3 H]-thymidine per well for the last 6 h of the assay. The minimal detectable amount of GM-CSF was 1 U/ml (50 U/ml defined as that producing half maximal FD5/12 proliferation). TGF-β bioactivity was measured using Mv-1-Lu cells as previously described (71), except that cell numbers were quantified by the addition of Alamar Blue for the last 24 h of the assay. The minimal detectable amount of TGF-β in this assay was 15 pg/ml. Cytokine bioassays were standardised against recombinant cytokines and the specificity of the assays was confirmed by the use of cytokine specific neutralising antibodies. TGF-β1 immunoactivity was measured in a specific ELISA (R&D Systems) according to the manufacturers instructions.
[0073] Immunohistochemistry. Uterine tissue was embedded in OCT Tissue Tck (Miles Scientific) and frozen in isopropanol cooled by liquid N 2 , then stored at −80° C. until use. Six μm semi-serial sections were cut from uteri collected at 1400 h on the day of estrus or day 1 of pregnancy, or from mice injected with rhTGF-β1 and fixed in 96% ethanol (4° C./10 min). For mAb staining, sections were incubated with mAbs (neat hybridoma supernatant containing 10% normal mouse serum [NMS]) and goat anti-rat-horseradish peroxidase (HRP; Dako, 1:20 in PBS containing 10% NMS) as detailed previously (19). To visualise HRP or endogenous peroxidase (to detect eosinophils), slides were incubated in diaminobenzidine (Sigma)(5 mg/ml in 0.05 M Tris-HCl pH 7.2) plus 0.02% hydrogen peroxide for 10 min at room temperature. After counterstaining in haematoxylin the sections were analysed using a video image analysis package (Video Pro, Faulding Imaging, Adelaide) in which the area of positive staining in the endometrial stroma was expressed as a percentage of total cell staining.
[0074] Anti-sperm antibody ELISA: A solid phase ELISA technique modified from the protocol of Okada (66) was used to quantify the serum content of sperm-specific immunoglobulins in an isotype-specific manner. Antigen was prepared by disruption of freshly isolated CBA sperm (5×10 6 sperm/ml in PBS) using a Branson sonicator. 50 μl of sperm antigen suspension was added to polystyrene 96 well flat-bottomed ELISA plates (Maxisorb™, Nunc), and incubated overnight at 4° C. Plates were blocked with PBS/3% BSA for 1 h, and stored at −20° C. until use. Serum was diluted 1:4 in PBS, then serially diluted 1:2 to a final dilution of 1:128, before 2 h incubation in the thawed sperm antigen-coated plates. Bound immunoglobulin was detected with rabbit α mouse antibody (Mouse Typer™, BioRad; 1 hr), followed by biotinylated donkey α rabbit antibody (Amersham, UK: 1:2000 in PBS/1% BSA; 1 hr) and streptavidin-HRP (Amersham; 1:4000 in PBS; 30 mins). HRP was visualised by the addition of tetra methylbenzidine (TMB, Sigma; 20 mins) following acidification of product with 1 M H 2 SO 4 . Quantification of each immunoglobulin isotype (IgG 1 , IgG 2a , IgG 2b ) was performed in duplicate, and all incubations were at room temperature. The antibody titre of each serum was determined by plotting A 150 against titration.
[0075] Sperm antigen delayed type hypersensitivity (DTH) response: A footpad swelling assay (69) was employed to measure the DTH response against sperm antigens. Balb/c F1 mice were primed on two occasions separated by one month by intra-uterine inoculation with sperm antigens in the presence or absence of TGFβ, and 10 days later, footpad thickness was measured using a micrometer gauge (0.01 mm increments) (Mitutoyo, Tokyo, Japan) before and 24 h following injection into the hind footpad of 25 μl of sperm suspension (1×10 8 sperm 1 ml in HBSS). Antigen-specific swelling was calculated by subtracting the thickness of contralateral footpads injected with HBSS.
[0076] Human leukocyte chemotaxis assay: Leukocyte populations were obtained from human peripheral blood using Ficoll-Paque™ density gradient centrifugation, according to the method described by Boyum (68). Peripheral blood mononuclear cells (PBMC: lymphocytes and monocytes) were suspended in HBSS containing 10% ECM-FCS at 5×10 5 cells/ml. The chemotaxis assay was a modification of a Boyden chamber protocol described by Bignold (69). Cervical keratinocyte culture supernatants (diluted 1:1 with HBSS/10% ECM-FCS), HBSS/10% ECM-FCS, or N-formyl-methionyl-leucyl-phenylalanine (FMLP, Sigma) were added to the bottom half of chambers and were separated from PBMCs by 3 μm polycarbonate mounted adjacent to an 8 μm polycarbonate sparse-pore filter (Nuclepore). Following 45-60 mins incubation at 37° C., during which time PBMCs migrating through the 8 μm sparse-pore filter were trapped on the surface of the underlying 3 μm filter, cells were fixed by addition of 1 ml of 10% formalin and quantified by manual counting after staining with Mayer's haematoxylin. Mean cell numbers (±s.d.) of triplicate measurements were made for each test sample.
EXAMPLE 1
[0000] Seminal TGFβ Initiates the Post Mating Inflammatory Response in Mice and Humans
[0077] The cytokine GM-CSF, produced by the uterine epithelium following contact with seminal vesicle secretions, is thought to be pivotal to the generation of maternal tolerance since it is largely responsible for initiating the leukocytic influx into the female reproductive tract after mating and for increasing the antigen presenting capacity of these cells.
[0078] Seminal vesicle fluid was fractionated by size exclusion chromatography in order to identify GM-CSF-stimulating activity. Two fractions were identified; a high molecular weight (650 kDA) proteinacous moiety and a intermediate molecular weight, more heterogenous moiety eluting between 150-440 kDa (10.62). The latter moiety was identified as TGFβ 1 , on the basis of findings that it's GM-CSF stimulating activity was enhanced by acid activation, that TGFβ 1 immunoactivity and bioactivity co-eluted in the same fraction, and that anti-TGFβ 1 neutralising antibody could block the GM-CSF stimulating activity of this fraction ( FIGS. 1,2 ). The molecular weight of the GM-CSF stimulating activity in seminal vesicle fluid (150-440 kDa) is consistent with that of the latent form of TGF-β 1 , a complex of 230-290 kDa which comprises of the mature TGF-β dimer (25 kDa) non-covalently associated with a 75-80 kDa latency associated protein and a 130-190 kDa binding protein (23).
[0079] The TGF-β 1 content of murine seminal vesicle secretions, like that of human seminal plasma (22), was found to be extraordinarily high and second only to that reported for platelet distillate (23). Furthermore the seminal vesicle gland secretions were identified as contributing in excess of 90% of total ejaculate TGFβ 1 content, with the prostate and coagulating gland secretions containing only small amounts of TGFβ 1 . The addition of rTGFβ 1 to uterine epithelial cells in culture and in vivo was confirmed to increase uterine epithelial GM-CSF output in a dose responsive manner ( FIG. 3 ).
[0080] The administration of rTGFβ1 to the uterine lumen of oestrus mice was observed to not only increase uterine GM-CSF production, but also initiate an influx and activation of inflammatory cells similar to that seen following mating (Table 1 and FIG. 6 ). This result further supports the proposal that TGFβ can fully replicate the post-mating inflammatory response induced in the natural situation by seminal plasma.
[0081] In vitro experiments with human cervical keratinocytes and endometrial tissue indicated that both semen and rTGFβ 1 can elicit an increase in GM-CSF production from reproductive tract tissues in women ( FIG. 7 ). Furthermore, the content of leukocyte chemotactic activity in supernatants from keratinocyte cultures was enhanced by treatment with either semen or rTGFβ 1 ( FIG. 8 ), further supporting a principal role for seminal TGFβ in the post-mating inflammatory cascade in women (63).
TABLE 1 The effect of intra-uterine injection with TGF-β 1 on endometrial leukocyte parameters. treatment n CD45 F4/80 Mac-1 Ia RB6-8C5 peroxidase vehicle 5 15 (8-19) a 15 (12-25) a 9 (7-21) a 20 (8-23) a 11 (5-15) a 4 (4-7) a rhTGF-β 1 4 28 (13-39) ab 37 (30-48) b 23 (18-42) a 25 (15-35) ab 15 (4-20) a 15 (11-19) b mated 4 41 (30-60) b 31 (21-49) b 48 (46-56) b 32 (26-57) b 36 (15-41) b 13 (10-20) b
[0082] Tissues were collected 16 h after natural mating with intact males, or after administration of 20 ng rhTGF-β 1 in 50 μl PBS/1% BSA, or vehicle only, to the uterine luminal cavity of estrous mice. The reactivity of endometrial tissue with mAbs specific for all leukocytes (anti-LCA), macrophages (F4/80 and anti-Mac-1), neutrophils (anti-Mac-1 and RB6-8C5), and activated macrophages/dendritic cells (Ia), was determined by immunohistochemistry and video image analysis. Eosinophils were detected by staining for endogenous peroxidase activity (peroxidase). Reactivity with mAbs are expressed as the median (range) percent positivity. The number of mice in each experimental group=n. Data were compared by Kruskal-Wallis one way ANOVA and Mann Whitney Rank Sum test. Data sets labelled with different lower case letters within columns denote statistical significance between treatment groups (p<0.01).
EXAMPLE 2
[0000] Seminal Vesicle Fluid Modulates Maternal Reproductive Performance and the Maternal Immune Responsive to Paternal Antigens.
[0083] Previously, exposure to semen at mating was found to cause an intense but transient inflammatory response, and factors in seminal plasma derived from the seminal vesicle were implicated in this response. In studies in mice, the inventors have identified seminal vesicle fluid as a pivotal determinant in optimal embryo development and implantation. Furthermore, exposure to semen at mating has been shown to have an important role in inducing maternal tolerance prior to implantation, and factors present in seminal plasma have been identified as necessary for induction of this state, suggesting that the beneficial effect of seminal plasma on pregnancy outcome may at least in part be due to the immune deviating effects of this fluid.
[0084] To test the importance of exposure to seminal reside fluid for pregnancy success. Balb/c F1 females were mated with CBA males from which the seminal vesicles had been surgically removed (SV− studs). No implantation sites were present in the uterus on day 17 of pregnancy (n=12 females). This total infertility was not due to a lack of fertilisation, but rather was associated with implantation failure or early fetal resorption. This may reflect insufficient maternal tolerance of the semi-allogencic embryos due to the lack or exposure to seminal reside TGFβ at mating.
TABLE II Effect of seminal plasma on embryonic development of mice. Intact SV− Number of females with embryos 8/8 (100%) 8/8 (100%) on day 3 (%) # embryos @ day 3 (mean ± SD) 8.0 ± 2.1 9.0 ± 2.0 Number of females with implantation 10/10 (100%) 0/12 (0%) sites on day 17 (%) # implants @ day 17 (mean ± SD) 7.5 ± 1.8 0
[0085] Balb/c F1 mice mated naturally with intact or seminal vesicle-deficient (SV−) CBA males were sacrificed at 1600 h on day 3 to assess embryonic development, or on day 17 to determine number of implantation sites.
[0086] To investigate the importance of semen, particularly seminal vesicle fluid, on the induction of Th1 immune response to paternal MHC antigens, Balb/k (H-2 k ) female mice were mated with intact Balb/k or congenic Balb/c (H-2 d ) stud males, or Balb/c SV− studs. To achieve psuedopregnancy, the uteri of Balb/k females were ligated at the oviductal junction 2 weeks prior to mating. Immune responsiveness to MHC class I (H-2 d ) antigen was assessed by measuring the growth of tumor cells injected on day 4 of pregnancy or psuedopregnancy. Tumor cells were rejected in most Balb/k females mated with Balb/k males, but grew in pregnant or psuedopregnant Balb/k females mated with Balb/c males. In contrast, tumors did not usually grow in Balb/k mice mated with SV− Balb/c males. These data demonstrate that exposure to semen is sufficient to induce specific tolerance to paternal MHC class I antigens, even in the absence of an ensuing pregnancy, and show that this tolerance is dependent on factors derived from the seminal vesicle (Table III).
TABLE III Effect of pregnancy and psuedopregnancy on rejection of Balb/c JR-5 fibrosarcoma cells in Balb/k mice. status at tumor growth median tumor Female Male JR-5 injection at day 17 (%) size# Balb/c virgin 11/11 (100) ++++ Balb/c Balb/c d4 pregnant 5/5 (100) ++++ Balb/k virgin 0/10 (0) − Balb/k Balb/c d4 pregnant 13/14 (93) +++ Balb/k Balb/c (vas) d4 psuedo- 5/7 (71) ++ pregnant Balb/k Balb/c (SV−) d4 pregnant 4/11 (36) ++ Balb/k Balb/c d4 psuedo- 9/9 (100) +++ (ut lig) pregnant Balb/k Balb/k d4 pregnant 5/15 (33) + Balb/k C57Blk × d4 pregnant 4/8 (50) + CBA Balb/k C57Blk × d4 psuedo- 4/8 (50) + (ut lig) CBA pregnant
[0087] Balb/c (H-2 d ) or Balb/k (H-2 k ) female mice were mated with Balb/c or C57Blk×CBA F1(H-2b/k) studs. In some groups the uteri of Balb/k females were ligated at the oviductal junction 2 weeks prior to mating (ut lig). Other groups of intact Balb/k mice were mated with vasectomised Balb/c males (vas) or Balb/c males from which the seminal vesicles were removed at least 2 weeks prior to mating (SV−). The day of finding a vaginal plug was designated day 1 of pregnancy or psuedopregnancy. Balb/c tumor cells (JR-5 fibrosarcoma cells, 10 5 ) were injected s.c. on day 4, and tumor growth (diameter, in two dimensions) was measured on day 17 of pregnancy or psuedopregnancy (++++=>8 mm; +++=>5 mm; +=1-3 mm).
EXAMPLE 3
[0000] Seminal TGFβ is an Immune Deviating Agent
[0088] To assess the effect of TGFβ on induction of Th1 and Th2 immune responses against CBA sperm antigens, Balb/c F1 female mice were immunised by intra-uterine infusion with CBA sperm, in the presence or absence of rTGFβ, on two occasions separated by 4 weeks. Development of Th1 anti-sperm immunity was assessed two weeks later by measuring the DTH response to a subcutaneous sperm antigen challenge, and by measuring serum content of anti-sperm reactive immunoglobulin of the IgG 2b subclass. Whereas sperm administered alone or in the presence of Freunds Complete Adjuvant elicited a strong DTH response and a moderate IgG2b antibody response, immunisation in the presence of TGFβ substantially diminished both of these parameters, and was comparable to the response elicited by natural mating ( FIG. 8 ). In contrast, synthesis of sperm-reactive immunoglobulin of the IgG1 isotype (indicating induction of a Th2 response) occurred to a similar extent in all treatment groups, regardless of the presence of TGFβ in the immunising inoculum.
[0089] In another experiment, the effect of TGFβ on the induction of ‘tolerance’ to paternal MHC antigens associated with sperm was investigated. Balb/k (H-2k) female mice that were given intra-uterine infusions of sperm from Balb/c (H-2d) males together with rTGFβ 1 were not able to reject paternal MHC antigen-bearing tumour cells injected 4 days later, whereas tumours were rejected in naïve mice or mice given sperm alone (Table IV). Tumour rejection was also compromised in mice that administered TGFβ without sperm antigen, although tumours in this treatment group were not as large as those which grew in mice that received both antigen and TGFβ.
[0090] Both of these experiments show that delivery of paternal antigens in combination with TGFβ to the female reproductive tract can generate systemic paternal antigen-specific tolerance, specifically by inhibiting the Th1 compartment of the immune response. This immune deviating effect is dependent on the administration of TGFβ since antigen given alone elicits Th1 immunity as opposed to tolerance. TGFβ given in the absence of antigen may confer a state of partial, non-antigen specific tolerance.
TABLE IV The effect of intra-uterine immunisation with Balb/c sperm and TGFβ on rejection of Balb/c JR-5 fibrosarcoma cells in virgin Balb/k mice. tumor growth median Treatment at day 17 (%) tumor size# 5 × 10 6 Balb/c sperm 3/8 (38) + 10 ng TGFβ 5/7 (71) +++ 5 × 10 6 Balb/c sperm + 6/9 (67) ++++ 10 ng TGFβ Control (PBS) 0/6 (0) −
[0091] Balb/k female mice were uterine ligated, and after two weeks rest were synchronised into estrous by administration of GnRH agonist. At 0900 h-1200 h on the day of estrous, mice were anaesthetised and given intra-uterine injections of 5×10 6 Balb/c sperm and/or 10 ng TGFβ in 100 ul of PBS (50 ul administered per horn). Balb/c tumor cells (JR-5 fibrosarcoma cells, 10 5 ) were injected s.c. 72 h after surgery, and tumor growth (diameter, in two dimensions) was measured 13 days later (++++=>8 mm; +++=>5 mm; +=1-3 mm).
EXAMPLE 4
[0000] Paternal Antigen-Specific Immune Deviation Improves Reproductive Performance
[0092] The experiments described above show that seminal vesicle secretions can elicit Th1 hypo-responsiveness which manifests as ‘tolerance’ in the maternal immune response specific for seminal antigens, including but not likely to be limited to paternal MHC antigens, deposited in the female reproductive tract at mating. The data suggest that diminished reproductive outcome ensues when a pregnancy has been initiated in the absence of exposure to seminal plasma, perhaps because of inadequate induction of maternal ‘tolerance’ to conceptus antigens. An experiment was therefore performed to test the hypothesis that a prior state of TGFβ-mediated ‘tolerance’ to antigens in paternal semen can benefit reproductive performance. This experiment consisted of immunisation by intra-uterine infusion of Balb/c F1 females with CBA sperm, with or without rTGFβ 1 , two weeks before mating with intact CBA male studs. Immunisation with sperm plus TGFβ 1 resulted in an increase in mean fetal and placental weight (Table V), despite a small decline in litter size which was evident in all females immunised with sperm regardless of the presence of TGFβ. This increase was still apparent after adjustment for different fetal numbers per uterine horn, thereby discounting an effect of litter size ( FIG. 9 ).
[0093] Induction of Th1 hypo-responsiveness against paternal antigens has been reported to result in an improved pregnancy outcome in women previously experiencing recurrent miscarriage (102). While no data exist on the ability of paternal antigen/TGFβ immunisation to initiate Th1 hypo-responsiveness against paternal antigens, or to deviate previously existing Th1 immune responses in women, nor on the ability of TGFβ to improve reproductive outcome, this is likely to be the case. The inventors have been the first to conduct a large randomised, controlled trial investigating the effect of semen exposure on IVF treatment outcome. This trial has confirmed that women exposed to semen (containing paternal antigen and natural TGFβ) around the time of thawed embryo transfer have a reduced risk of early embryonic loss compared to those instructed to abstain (Table VI). This improvement in reproductive outcome is likely to be mediated by maternal immune tolerance towards paternal antigens initiated by TGFβ and seminal antigens at the time of intercourse.
TABLE V Effect of prior immunisation with sperm and TGFβ on reproductive outcome in mice Control sperm + TGFβ 1 sperm number 139 144 103 litter size 11.4 ± 1.0 a 10.4 ± 1.2 b 10.3 ± 0.9 b (total) litter size 11.25 ± 1.3 a 10.1 ± 1.5 b 10.1 ± 0.9 b (viable) # resorptions 0.167 ± 0.58 a 0.21 ± 0.58 a 0.20 ± 0.42 a fetal weight (mg) 645.2 ± 61.2 a 677.6 ± 56.6 b 646.1 ± 49.9 a placental weight 97.7 ± 12.1 a 105.2 ± 12.4 b 101.8 ± 9.8 b (mg) fetal:placental 6.69 ± 0.9 a 6.5 ± 0.8 ab 6.36 ± 0.8 b weight ratio
[0094] Balb/cF1 female mice were immunised by intra-uterine infusion with CBA sperm in the presence or absence of 10 ng rTGFβ 1 , and were mated naturally with CBA males 2 weeks later. Females were sacrificed on day 17 of pregnancy and the number of total, viable and resorbing implantation sites, as well as fetal and placental weights of viable conceptuses, were determined. Values are mean±SD. Comparisons between groups were by Kruskal Wallis one-way ANOVA followed by Mann Whitney rank sum test (p <0.05).
TABLE VI Effect of semen exposure around the time of thawed embryo transfer on early pregnancy outcome. signif- Intercourse abstain icance transfer cycles 59 56 NS embryos transferred 106 107 NS implantations (%) 11/106 (10.3) 11/107 (10.2) NS viable conceptus 10/106 (9.4) 7/107 (6.5) NS at 6 weeks (%) transfer cycles 9/59* (15.3) 7/56 (12.5) NS with biochemical pregnancy biochemical 0 (0) 2/11 (8.2) NS pregnancy loss clinical 1/11 (9) 2/11 (18.2) NS miscarriage total pregnancy 1/11 (9) 4/11 (36.4) 0.043 wastage Pregnancy outcome following thawed embryo transfer. Patient characteristics were not significantly different between the two groups. An biochemical pregnancy was defined as one serum βHCG exceeding 25 IU and a clinical pregnancy as a conceptus/fetal pole seen at ultrasound at 6 weeks gestation. Statistical analysis was performed using the Chi square calculation. NS = not significant. *= one twin pregnancy.
[0095] Pregnancy outcome following thawed embryo transfer. Patient characteristics were not significantly different between the two groups. An biochemical pregnancy was defined as one serum βHCG exceeding 25 IU and a clinical pregnancy as a conceptus/fetal pole seen at ultrasound at 6 weeks gestation. Statistical analysis was performed using the Chi square calculation. NS=not significant. *=one twin pregnancy.
REFERENCES
[0000]
1. Barratt et al. (1990) Hum. Reprod. 5, 639-648.
2. De et al (1991) J. Leukocyte Biol. 50, 252-262.
3. Kachkache et al (1991) Biol. Reprod. 45, 860868-868.
4. Mcmaster et al (1992) J. Immunol. 148, 1699-1705.
5. Beer & Billingham (1974) J. Reprod. Fert. Suppl. 21, 59-88.
6. Clarke (1984) in Immunological aspects of reproduction in mammals, ed. Crighton, (Butterworths, London), pp. 153-182.
7. Hunt et al (1984) Cell. Immunol 85, 499-510.
8. Robertson & Seamark (1990) Reprod. Fertil. Dev. 2, 359-368.
9. Head et al (1991) in The Molecular and Cellular Immunobiology of the Maternal-Fetal Interface, eds. Wegmann et al (Oxford University Press, New York),
10. Robertson et al. (1996) J Reprod Fert 107, 265-277
11. Robertson et al (1994) in Serono Symposium on the Immunobiology of Reproduction, eds. Hunt & Burnett.
13. Wilbanks et al. (1992) Eur. J. Immunol. 22, 165-173.
14. Duhrsen (1988) Leukaemia 2, 334-342.
15. Austyn & Gordon. (1981) Eur. J. Immunol. 11, 805
16. Conlan & North. (1994) J. Exp. Med. 179, 259-268.
17. Whitten. (1956) J. Endocrinol. 14.160-163.
18. Lawrence et al. (1984) J. Cell Physiol. 121, 184-188.
19. Robertson et al. (1992) Biol Reprod. 46, 1069-1079.
20. Anderson et al. (1983) J. Reprod. Fertil. 68, 1-7.
21. Mann, T. (1964) The biochemistry of semen and the male reproductive tract (John Wiley and Sons. Inc.,
22. Nocera & Chu (1995) Am. J. Reprod Immunol. 33, 282-291.
23. Wakefield et al. (1988) J. Biol. Chem. 263, 7646-7654.
24. Massague. (1990) Annu. Rev. Cell Biol. 6, 597-641.
25. Andres. (1989) J. Cell Biol. 109, 3137-3145.
26. Wakefield et al (1990) J. Clin. Invest. 86, 1976-1984.
27. Wahl (1992) J. Clin. Immunol. 12.61-74.
28. Finlay et al. (1983) Endocrinology 112, 856-861.
29. Danglot er al. (1986) FEBS Lett. 194, 96-100.
30. Weiner et al (1994) Annu. Rev. Immunol 12.809-837.
31. Tafuri et al. (1995) Science 270, 630-633.
32. Wegmann et al. (1993) Immunol. Today 14.353-356.
34. Anderson & Tarter (1982) J. Immunol. 128.535-539.
35. Lee & Ha (1989) Int Arch Allergy Appl Immunol 88, 412-419.
36. Pang et al. (1979) J. Reprod Fert. 56, 129-132.
37. Peitz & Olds Clarke. (1986) Biol. Reprod. 35.608-617.
38. Polge. (1982) in Control of pig reproduction, eds. Cole & Foxcroft. (Butterworths, London), pp. 277-291.
39. Mah et al (1985) J. Anim. Sci. 60, 1052-1054.
40. Walker et al. (1992) Theriogenology 37, 111-126.
41. Murray et al. (1983) J Anim Sci 56,895-900.
42. Stone et al. (1987) Proc. Am. Fert. Soc. 43, 88
43. Klonoff-Cohen et al. (1989) JAMA. 262, 3143-3147.
44. Robillard et al (1995) The Lancet 344, 973-975.
45. Bellinge et al. (1986) Fertil. Steril. 46, 2523-2526.
46. Breyere and Burhoe (1964) Ann. NY Acad. Sci. 120, 430-434
47. Kester et at (1971) J. Clin. Path. 24, 726-730
48. Dekker et at (1996) Abstract No 516 Amt J Obstet Gyn
49. Kajina et at Am J Reprod. Immun. 17, 91-95
50. Scott et at (1987) Obst. Gyn. 70, 645
51. Gleicher (1994) Am. J Reprod Immun. 32, 55-72
52. Coulam & Stern Reprod Immun Serono Symposium 97, 205-216, Eds Donero & Johnson
53. Kutten et at (1992) Mol Androl, 4, 183-193
54. Klonoff-Cohen et at (1989) JAMA 262, 3143-3147
55. Robillard et at (1995) Lancet 344, 93-975
56. Stephen E H (1996) Fert Steril 66, 205-9
57. Hakim et at (1995) Am J Obstet Gyn 172, 1510-7
58. Weinberg et at (1988) Fert Steril 50, 993-5
59. Lenton et at (1988) Ann NY Acad Sci 541, 498-509
60. Neumann et at (1994) N Eng J Med 331, 239-43
61. Stern et at (1997) Am J Reprod Immun 37, 352-3
63. Tremellen et at (1997) J Reprod Immun 34, 76-7
64. Bentin-Ley et al (1994) J Reprod Fert 101, 327-32
65. Reinwald et at (1975) Cell 6, 331-44
66. Okada et at (1993) Am J Reprod Immunol 29,241-6
67. Lee et at (1989) Int Arch Allergy Appl Immun 88, 412-19
68. Boyden S V (1962) J Exp Med 115, 453-61
69. Bignold L P (1989) J Immun Method 118, 217-25
70. Medwar P B (1953) Symp Soc Exp Biol 44, 320-38
71. Like et al (1986) J Biol Chem 261, 13426-29
72. Gordon et at (1987) Nature. 326: 403-5
73. Robertson et al. (1991) The Molecular and Cellular Immunobiology of the Maternal - Fetal Interface . (Oxford University Press, New York) pp 191-206. Eds: Wegmann, Nisbett-Brown & Gill.
74. de Moraes & Hansen (1997) Biol Reprod 57:1060-1065.
75. Imakawa et al. (1993) Endocrin. 132: 1869-71. | A method of treating an infertility condition in humans or mammals, by exposure of a prospective mother to TGFβ or derivative or analog of TGFβ. The exposure is advantageously in conjunction with one or more antigens of a prospective father so that a hyporesponsive immune reaction is mounted to the one or more antigens of the prospective father. | 0 |
REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 10/404,942, filed 31 Mar. 2003, now U.S. Pat. No. 6,832,865, which is a continuation of U.S. application Ser. No. 09/661,968, filed 14 Sep. 2000, now U.S. Pat. No. 6,572,293.
FIELD OF THE INVENTION
This invention relates to a document reproduction apparatus and in particular to a simple and inexpensive high-capacity output catch tray for document production devices such as copiers, printers and fax machines.
BACKGROUND OF THE INVENTION
A. High Capacity Output Stacking Trays
In the prior art of output trays there has generally been an association of large, complex and expensive high volume copiers with similarly large, complex and expensive high capacity output collecting devices such as elevator trays, collators, sorters, vertically repositionable sheet output ports, and “mailbox” systems. In part this is because high volume copiers often must be capable of being coupled to subsequent machines in a production line, requiring that the top of the output stack be maintained at a relatively precise elevation for pickup by the next machine in the production line. However, where subsequent processing is not necessary there has previously been no simple, inexpensive, high capacity output stacking tray system available as a final station for such high volume copiers which did not suffer from various drawbacks addressed by the present invention.
Similarly, there has been an association of smaller, slower, and less expensive copiers with small, fixed, limited capacity output trays. High capacity output trays or systems with elevators or multiple trays generally either been unavailable for such smaller machines, or are too expensive to be suitable for the typical uses of such machines.
In all types of document production machines such as copiers, printers and fax machines, but particularly copiers for high speed, high volume production runs, the production of sheets by the copier can often exceed the capacity of presently available output catch tray systems. High capacity output trays, often referred to in the art as “stackers,” are particularly desirable for the collected output of high speed or plural job batching copiers or printers. High capacity stackers are also desirable for the accumulated output of unattended plural user (networked) copiers and printers, of any speed.
Further by way of background on sheet stacking difficulties in general, outputted sheets are usually ejected into an output tray from above one side thereof. Normal output stacking is by ejecting sheets or sets of sheets from above one side of the top sheet of the stack of sheets onto which that additional ejected sheet or set of sheets must also stack. Typically, sheets or sets are ejected generally horizontally (or slightly uphill initially) and continue to move horizontally primarily by inertia. That is, sheets or sets in the process of being stacked are not typically effectively controlled or guided once they are released into the output tray. The sheets or sets fall by gravity into the tray to settle onto the top of the stack. However, such settling is resisted by the relatively high air resistance of the sheet or set to movement in that direction. Yet, for high volume copiers stacking must be done at high speed, so a long settling time is undesirable. Thus, a long drop onto the stack is undesirable.
Stacking is made even more difficult where there are variations in thickness, material, weight and condition (such as curls) of the sheets. Different sizes or types of sheets, such as tabbed or cover sheets or Z-folded or other inserts, may even be intermixed in the stack. The ejection trajectory and stacking should thus accommodate the varying aerodynamic characteristics of such various rapidly moving sheets or sets. A fast moving sheet or set can act as a variable airfoil to aerodynamically affect the rise or fall of the lead edge of the sheet as it is ejected. This airfoil effect can be strongly affected by curls induced in the sheet, by fusing, color printing, etc. Therefore, an upward trajectory output angle and substantial release height is often provided, well above the top of the stack. Otherwise, the lead edge of the entering document can catch or snub on the top of the stack already in the output tray, and curl over, causing a serious jam condition. However, setting too high a document ejection level to accommodate all these possible stacking problems greatly increases the settling time for all sheets or sets and creates other potential problems, such as scattering.
Scatter within a stack causes at least four problems. First, if copier has a sets offsetting feature, intended to provide job set separations or distinctions, scatter within a stack makes such set distinction more difficult. Second, misaligned sheets or sets tend to incur damage such as bending, folding, abrasion or tearing of sheet edges out of alignment with the overall stack edge. Third, a substantial stack within which individual sheets are not well aligned to each other is more difficult for an operator to grasp and remove from the stacker. Fourth, a misaligned stack is not easily loaded into a box or other transporting container of corresponding dimensions.
For the above listed reasons, it may be seen that the top of stack elevation should be maintained within a desired range. A tray elevator or vertically repositionable sheet output port is therefore normally provided to maintain a relatively constant relationship of sheet output elevation to top of stack elevation for high capacity output trays.
Numerous means for dealing with various such general problems of sheet stacking are taught in U.S. Pat. No. 4,385,758, U.S. Pat. No. 4,469,319, U.S. Pat. No. 5,005,821, U.S. Pat. No. 5,014,976, U.S. Pat. No. 5,014,977, U.S. Pat. No. 5,033,731, and art therein. Sheet “knock down” or settling assistance systems are known, but add cost and complexity and can undesirably prematurely deflect down the lead edge of the ejected sheet. Also, such “knock down” systems can interfere with sheet stack removal or loading and can be damaged thereby. Also, stacking systems should desirably provide relatively “open” trays, which will not interfere with open operator access to the output stacking tray or bin, for ease of removal of the sheet stack therein.
Many attempts have been made in the prior art to provide high capacity sheet stacking output trays. Among these are: U.S. Pat. No. 5,609,333 (describing a sheet stack height control system); U.S. Pat. No. 5,318,401 (describing a stacking tray system with nonvertically receding elevator yielding square stacks); U.S. Pat. No. 5,346,203 (describing a high capacity sheet stacking system with variable height input and stacking registration); U.S. Pat. No. 4,329,046 (describing a method for operating a reproduction machine with unlimited catch tray for multimode operation); U.S. Pat. No. 4,141,546 (describing a mini-collator/sorter); U.S. Pat. No. 4,012,032 (describing a sheet handling system with a receiving tray for use in non-collate mode and a plurality of collator bins for operating in collator mode); U.S. Pat. No. 4,026,543 (describing a control system using a copy count, a tangent copy count, and a document tracing indicator to provide automatic control for copy overflows); U.S. Pat. No. 4,134,581 (describing a system having multiple collator bins treated as one virtual bin.)
In these systems there are generally two approaches to increasing output catch tray capacity. The first approach uses multiple receipt trays, bins or mailboxes (for simplicity, collectively referred to as “trays). The trays may be vertically or horizontally repositionable relative to a fixed output port, or the copier output port may be vertically or horizontally repositionable relative to a fixed tray or trays, or some combination of movable trays and moveable output port may be employed. However, although though multiple trays are in use, the individual trays generally have limited capacities requiring either additional control for tray switching, system shutdown or additional operator intervention.
In the second approach a single large output catch tray is used, but relatively powerful, complicated and expensive elevator mechanisms are required either to lower the catch tray or raise the copier output port as the stack grows in order to keep the top of the stack within an acceptable range below the sheet output port. As far as is presently known, prior art does not include the combination of a single large output catch tray with a vertically repositionable output port.
Other systems such as U.S. Pat. No. 3,871,643 teach a sorter system having two sorter sections. In particular, the control switches from one section to the next to continue a copying job. Also, if the bins in both sections of the sorter contain copy sheets, and the job requirement has not been completed, upon removal of the copy sheets in one of the sections, the reproduction machine will resume operation after having been temporarily halted.
The addition of multiple bins and trays, catch trays with elevator mechanism, or vertically repositionable copier output port increases the complexity of the components for copiers and their controls, with a corresponding decrease in expected reliability and increase in cost. It would therefore be desirable to provide a high capacity output catch tray for document production machines such as photocopiers, printers and fax machines having a minimum number of receiving trays and/or complex mechanisms and yet be able to handle high volume requirements with minimum operator intervention. Due to the lack of such a device, it is not unknown in the prior art to use stacks of cardboard boxes as cheap, high capacity output “trays.”
B. Inclined Output Trays
For better stacking alignment to obtain neat, square and even-sided stacks, as is known in the art, it is preferable to output sheets or sets sequentially onto an inclined surface. Initially this is the inclined surface of the empty output tray, and then it is the correspondingly inclined upper surface of the sheet or set previously stacked thereon. If the output tray surface is upwardly inclined away from the copier output port into the tray, this is known in the art as “uphill” stacking. It is called “downhill” stacking if the output tray slopes downwardly away from the copier output port. There are many advantages to using either “uphill” or “downhill” stacking, either for stacking per se, or for stacking in a compiler for stapling or other binding or finishing. It allows different sizes of sheets to be stacked using the same paper path and the same tray system, using gravity assisted stacking against a simple inboard or outboard alignment surface, and is therefore relatively less expensive than more complicated active stacking registration or alignment systems, such as those requiring scullers, flappers, tampers, joggers, etc.
“Uphill” stacking desirably lends itself to stacking alignment at an inboard side of the output tray, that is, at the side adjacent the copier. It automatically slows down the ejected sheets, due to their initial “uphill” movement. The sheets then reverse their movement to slide back down against an upstanding wall or edge adjacent to but underlying the output port. Incoming sheets thus do not get caught on the edge of the stack in the tray, so long as subsequent sheets or sets enter above the top of the stack, which of course grows in length/height as the copy job progresses.
Prior art does not provide for a high capacity single output tray which can quickly and easily be configured to provide uphill, horizontal or downhill output stacking without the use of a tray elevator or vertically repositionable sheet output port.
C. Stack Edge Alignment
It is known in the art to provide a stacking system with an output tray elevator. The top of a stack in the output tray is maintained at a suitable height for such stacking, by the output tray and all its contents being moved downward as the stack accumulates, so that the top of the stack remains in the same general relative position below the copier output port.
In prior art, the stacking alignment surface is normally a fixed vertical surface which does not move relative to the copier and its output port, and not an integral upstanding side of the tray itself, as in a sorter bin or other conventional stacking tray. That is, the alignment surface against which the ejected sheets or sets are aligned is typically the vertical surface of the side of the machine or the stacking tray elevator itself, against which the sheets or sets may align as they stack.
In part, such a fixed alignment surface addresses the problem that if, instead, a conventional alignment side wall integral (and substantially perpendicular to) the stacking tray were provided (moving therewith), that alignment wall require a height equal to the full elevator travel range of the output tray. Otherwise, sheets or sets stacked higher than that alignment wall would slide off the stack. In the empty, fully raised position of such an output tray, such a fixed height alignment side wall would unacceptably extend well above the top of the machine, and/or block the sheet entrance to the tray if located on that side of the tray for “uphill” stacking.
Also, with such an output tray designed for high capacity stacking, the first incoming sheets would be required to drop a substantial distance before coming to rest on the top of the stack or tray. This large drop distance tends to increase the number of stacking problems noted above, such as sheets or sets coming to rest in an orientation other than flat against the top of the stack, and/or substantial scatter within the stack.
However, previous systems with fixed alignment surfaces suffer from various drawbacks. Since the edges of the sheets in the stack move relative to the alignment surface, friction of the sheet edges against the alignment surface lifts the sheet edges relative to the downward motion of the output tray, abrading the sheet edges and disturbing the stack so that is less flat, neat and square. This phenomenon is known in the art as “creep.” With the extended use experienced by high volume copiers, over time, the friction also causes wear on the alignment surface so that it may become less smooth, exacerbating the problems of lift and creep. Fixed alignment surfaces must also be relatively long to provide high capacity and are therefore relatively bulky.
One previous attempt to deal with the problem of fixed alignment surfaces can be seen in U.S. Pat. No. 5,346,203, in which a variable height stack registration and edge alignment system is provided by way of numerous small belt-like flexible sheets which unroll upward corresponding to upward movement of a vertically repositionable sheet output port. However, as with previous tray elevator systems, this system is subject to the drawbacks of complexity, expense, and limited inter-connectivity; even more so in that it is associated with multiple output tray and/or mailbox systems.
It is therefore desirable to provide a simple, relatively smooth, variable length stack alignment and edge alignment system which corresponds directly and automatically to the output tray height and requires no external power source or control system.
To recapitulate, the limitations of the prior art of high capacity output trays are substantial. A simple fixed high capacity output tray without a vertically repositionable sheet output port is impractical because it requires either a high fixed side wall or that the output tray be very deep, so that ejected sheets or sets would have too far to drop and be subject to the abovementioned problems of scatter, disorientation, buckling, folding, etc. Vertically repositionable copier output ports, output tray elevators, multiple trays/bins/mailboxes are all relatively complex and high maintenance, require external power sources and controls, and are correspondingly expensive both initially and over time.
The present invention provides a simple, high capacity, adjustable, sheet stacking output tray suitable for connection to both large, high volume copiers and to smaller, less expensive ones, which is capable of automatically maintaining the top of stack height within an acceptable range relative to the sheet output port, without external power source or control, where precise stack height control is not required. The various adjustments in output tray angle, stack angle, effective spring rate, total weight capacity, and total stack height permitted by the invention allow a user to customize and optimize the invention for numerous applications. The invention thus uniquely provides for maximum upgrade-ability, downgrade-ability and compatibility between various sizes, types and brands of document production devices.
SUMMARY OF THE INVENTION
Briefly, the present invention is concerned with a simple, inexpensive high capacity output catch tray. The disclosed output tray automatically increases in capacity as the stack of copies in it accumulates, without external power source or control, while maintaining a relatively constant elevation relative to the copier output port, and automatically returns to its original position when partially or completely unloaded.
The invention achieves these advantages by the use of trampoline-type arrangement that suspends a stack support platform by springs around its perimeter from a frame removably attached to the copier. As copies accumulate on the platform the weight of the copies causes the springs stretch and increases the capacity of the output tray. The springs act as energy-storing biasing elements which return the platform to its unloaded position when the stack of copies is removed from the tray, and may also act as variable length alignment surfaces to keep the accumulating stack neat and square. Preferably the springs have a relatively smooth outer surface such as is provided by telescoping cylindrical sleeves around metallic coil springs, elastic cords or bands, or bungee cords, to keep the sides of the stack straight and prevent the sheets from binding or rubbing as the stack increases in length, thereby minimizing lift or creep of the sheets relative to the platform and alignment surface, but other commonly known biasing devices such as weights and pulleys, could be used alone or in combination with springs.
The invention provides improved output stacking of multiple printed sheets, such as multiple sets or jobs of flimsy copy sheets sequentially outputted by a copier, with overall stack alignment for subsequent handling, particularly for large stacks, at relatively low cost, and without sacrificing desired stacking and alignment orientations. Further so disclosed is a stacking system with a variable length alignment surface coupled to a vertically movable stack support platform.
The invention has particular utility and application for high capacity stacking of pre-collated copy output sheet sets from a copier, which may include a compiler and finisher, where such output may require stacking relatively large numbers of completed copies in a relatively high stack. Such stacked copies may be individual sheets or sets which may be unfinished, or may be stapled, glued, bound, or otherwise finished and/or offset.
The invention further provides a high capacity output tray for stacking substantial quantities of the output from a copier on a stack support platform optionally providing an inclined stacking surface at a substantial angle from the horizontal for receiving and aligning sheets against an upright stack edge alignment surface. Here, with little or no relative movement between the alignment surface and the stack edge, this stack edge alignment surface is automatically varied in length below the copier output port and above the stack support platform in coordination with the change in stack length/height supported by the platform.
The invention overcomes the above and other problems and limitations of prior art, without requiring an externally powered tray elevator or variable height output port, yet without sacrificing the desired output and stacking positions for the ejected sheets or sets.
The copier may operate in a single mode producing simple stacks, or may operate in multiple modes with stacks, unstapled sets and/or stapled sets, the sets and stacks being offset in the catch tray. With the addition of a simple detector, the copier can be made to temporarily halt when the top of the stack reaches a specified height relative to the sheet output port to avoid spilling or jamming, then resume operation and continue to do so as the output tray is emptied until the job in process is either completed or canceled.
As to specific hardware components which may be used with the subject apparatus, or alternatives, it will be appreciated that, as is normally the case, various suitable such specific hardware components are known per se in other apparatus or applications, including the cited references and commercial applications thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned objects and features of the present invention can be more clearly understood from the following detailed description considered in conjunction with the following drawings, in which the same reference numerals denote the same elements throughout, and in which:
FIG. 1A is an isometric view of a simple “tampoline-style” high capacity output tray with springs configured to stack sheets vertically.
FIG. 1B is a cutaway side view of the same simple “trampoline-style” high capacity stacking output tray, showing a relatively small stack of outputted sheets stacked vertically.
FIG. 1C is a cutaway side view of the same simple “trampoline-style” high capacity stacking output tray, showing a relatively large stack of outputted sheets which has displaced the stack support platform vertically downward while maintaining the top of stack elevation within an acceptable range relative to the copier output port.
FIG. 1D is a side view of the same simple “trampoline-style” high capacity stacking output tray, showing an angled brace from the frame to the side of the document production machine for supporting the weight of large stacks of outputted sheets.
FIG. 1E is a side view of the same simple “trampoline-style” high capacity stacking output tray, showing a leg brace from the frame to the floor near the side of the document production machine for supporting the weight of relatively larger stacks of outputted sheets, and also showing a travel limiter to keep the stack support platform from moving too far down and over-extending the springs.
FIG. 1F is a side view of a simple “trampoline-style” high capacity stacking output tray with a large frame extending down to the floor on all sides of the stack, where part of the frame adjacent the document production machine also functions as a guide track to guide and stabilize the stack support platform as it moves downward, for supporting the weight of extremely large stacks of outputted sheets.
FIG. 2 shows an isometric view of an alternative simple “trampoline-style” high capacity stacking output tray with springs configured both to stack sheets vertically and to facilitate operator access for sheet removal.
FIG. 3A shows an isometric view of a wedge-shaped shim which can be positioned on the output tray to obtain either “uphill” or “downhill” stacking, depending on its orientation, or removed entirely to obtain flat stacking.
FIG. 3B shows uphill stacking accomplished by placing the low side of the shim toward the side of the output tray adjacent the copier and below the copier output port.
FIG. 3C shows downhill stacking accomplished by placing the high side of the shim toward the side of the output tray away from the copier and opposite the copier output port.
FIG. 4 shows a variable length stack edge alignment surface comprised of a wide belt which unrolls from the top of the output tray support frame in “windowshade” style to provide a smooth alignment surface which does not move relative to the stack.
FIG. 5 shows an alternative variable length stack edge alignment surface comprised of a wide belt which moves over a roller at the top of the output tray support frame, where one end of the belt is attached to the stack support platform and the other end of the belt is attached to a spring connected to the frame.
FIG. 6 shows an alternative simple, high capacity output tray where the biasing element is a telescoping cylinder that compresses as sheets are stacked on the stack support platform.
The present invention is not limited to the specific embodiments illustrated herein. The specific exemplary embodiments disclosed show a high-capacity stacking output tray that moves vertically downward, with either a flat or an inclined stacking surface at a selected stacking angle to the horizontal. With the addition of relatively simple angle adjustment devices such as variable length braces or wedges attached to the frame, it is possible to obtain substantially non-vertical downward movement of the output tray while maintaining the output tray surface at substantially a right angle to the direction of movement, thereby optimizing the alignment and square stacking capacity of the system.
DETAILED DESCRIPTION OF THE INVENTION
High Capacity Stacking Output Catch Tray
FIG. 1 shows a simple “trampoline-style” high capacity stacking output catch tray 100 with springs as biasing elements 120 connecting a frame 110 to a stack support platform 130 , wherein the springs 120 are configured to catch and accumulate a vertical stack of sheets or sets output by a document production machine such as a copier, printer, or fax machine. According to this embodiment, the frame 110 defines a rectangular opening somewhat larger than the approximate size of the sheets to be caught and stacked. Connected to or made as part of the frame 110 are coupling devices known in the art as hooks 115 used to couple the frame 110 to the copier. The springs 120 connect the frame 110 to the stack support platform 130 , the proximal ends 121 of the springs 120 being coupled to the frame 110 and the distal ends 122 of the springs 120 being coupled to and about the perimeter of a rectangular stack support platform 130 of approximately the size of the sheets to be stacked. The stack support platform 130 is thereby suspended from the frame 110 by means of the springs 120 and is free to move downward in an approximately vertical direction in response to the weight of an accumulating stack of sheets or sets output by the copier.
The rectangular dimensions of the frame 110 and stack support platform 130 may be varied, according to the dimensions of the sheets to be stacked, where relatively precise alignment of the stack edge is sought. Alternatively, where less precise alignment is required, a single large tray may suffice for all of the sizes of paper or documents which a particular copier is capable of producing. As a further alternative, a tray can be dimensioned to closely fit the stack in one direction but be relatively looser in another, for instance to allow for lateral offsetting of sets or jobs. As an additional further alternative, the frame 110 may be constructed in such a manner as to allow the lengths of its sides to be adjusted in the field by an operator, so that a single output tray 100 can be configured to define a plurality of differently dimensioned rectangles, according to the precise dimensions of the sheets to be stacked and other factors such as offsetting. The same may be provided with respect to the stack support platform 130 .
In the preferred embodiments shown, the springs 120 are arranged so as to provide triangulation and lateral stability to the stack support platform 130 , although the springs 120 could be configured so as to hang straight down or in some other arrangement. Additionally, one or more dampening devices in the nature of shock absorbers may be provided to further reduce swaying and resonant motion of the stack in response to cyclic rhythms or movements induced by operation of the copier.
As sheets or sets are ejected from the output port of the copier, they move across the top of the frame 110 until striking the opposite side of the frame 110 , whereupon the sideways movement of the ejected sheet is stopped above the rectangular opening defined by the frame 110 . The sheet or set then drops down through the rectangular opening of the frame 110 , initially onto the top of the stack support platform 130 and subsequently onto the top of the stack accumulating in the output tray 100 . When or before the output tray 100 reaches maximum capacity it is partially or completely emptied by an operator, reducing or eliminating the weight of the stack and allowing the springs 120 to reposition the stack support platform 130 upward to maintain either the unloaded stack support platform 130 or the top of the stack at an elevation within an acceptable range 170 relative to the elevation of the copier output port.
Preferably, one or more portions of the frame 110 on the side opposite the copier output port are higher than the output port to provide a backstop 111 , so that sheets ejected at an angle substantially upward of horizontal will not fly over the frame 110 but will instead strike the backstop 111 and be captured.
Although the preferred embodiment depicted in the figures utilizes coiled metallic springs 120 , numerous alternative energy-storing biasing elements may be provided such as springs of various configurations (coiled, leaf, torsion bar), elastic cords or bands made of rubber or elastomers, bungee cords, pressurized piston-cylinder devices, weights, and/or pulleys, alone or in combination with each other.
The springs 120 stretch in response to the weight of the stack accumulating on top of the stack support platform 130 , allowing the stack support platform 130 to move downward and accommodate a stack of increasing length while maintaining the elevation of the top of the accumulating stack within a desirable range 170 relative to the copier output port. Since the weight of the stack increases linearly with the length of the stack, springs are particularly well-suited for use as biasing elements because they can easily be fashioned to have an inherently linearly increasing spring rate which is directly proportionate to the vertical linear movement of the stack support platform 130 . Elastic cords or bands are specifically preferred for use as springs 120 because they can easily be fashioned with a relatively smooth exterior surface which is less likely than other types of springs to catch or bind the edges of sheets or stacks in the output tray 100 .
In addition, the energy storing capacity of the springs 120 provides assistance to an operator when lifting sheets and/or stacks to remove them from the output tray 100 .
Additionally, as the springs 120 stretch under the weight of the stack accumulating on top of the stack support platform 130 , the springs 120 simultaneously act as variable length alignment surfaces 140 to produce a substantially aligned, straight stack, without the need for an additional component to provide an alignment surface. Although in this embodiment there is some relative motion between the surface of the springs 120 as they stretch, and the edges of sheets or sets accumulating in the stack, such relative motion is far less than would occur with an alignment surface which was fixed in relation to the movement of the stack support platform 130 as in prior art. By thus reducing relative motion between the alignment surface and the edges of sheets or sets accumulating in the output tray 100 , friction and resulting binding, lifting and creeping of the stack edges is correspondingly reduced. The relatively smooth exterior surface of the preferred elastic cords or bands as springs 120 further reduces friction, binding, lifting and creeping, thereby additionally facilitating the aligning and straightening action of the springs 120 .
In the preferred embodiment, sufficient capacity is provided by the output tray 100 so that constant monitoring or attention by an operator will not be required, and an interval of at least several minutes will elapse between occasions when an operator must reduce or remove the stack of sheets and/or sets accumulated in the output tray 100 . However, if desired, one or more simple detectors and/or switches of types well known in the art can be added to provide signals to the copier or an operator to warn when maximum capacity of the output tray 100 is being approached or has been reached, and additionally if desired to cause the copier to cease output until the stack in the output tray 100 is removed or at least reduced.
In the preferred embodiment, variation in stack height capacity, weight capacity, and range of acceptable stack height relative to the copier output port, are accommodated by various combinations of springs 120 of different lengths and effective spring rates, and/or by additional mounting points on the frame 110 and stack support platform 130 to accommodate different numbers, sizes and arrangements of springs 120 . If desired, further adjustability can be added by various devices known in the art, such as screw adjusters which move the mounting points of the springs 120 to vary their tension or pre-load.
Depending on the desired size and capacity of the output tray 100 , the frame 110 may be entirely supported by and suspended from the hooks 115 coupled to the copier, in combination with cantilevered forces against the side of the copier, friction and the moment of inertia generated by the weight of the output tray 100 and the stack it contains, as depicted in most of the figures. In an alternative embodiment depicted in FIG. 1D , additional weight bearing capacity for large stacks is provided by at least one angled brace 112 in the nature of a knee brace, the upper end of which is attached to the frame 110 and the lower end of which rests against the side of the copier. In a further alternative embodiment shown in FIG. 1E , increased additional weight bearing capacity is provided by a leg 113 , the upper end of which is attached to the frame 110 and the lower end of which rests upon a floor or other horizontal surface adjacent the copier. In a final alternative embodiment as depicted in FIG. 1F , extreme weight bearing capacity is provided by enlarging the frame 110 so that its lower portion rests directly upon a floor or other horizontal surface adjacent the copier. To prevent the stack support platform 130 from traveling downward farther than may be desired, and thereby to limit the height and/or weight of the stack, an adjustable travel limiter 114 may be provided to contact the underside of the stack support platform 130 and prevent further downward movement of the stack support platform 130 , as depicted in FIG. 1E and FIG. 1F .
As also depicted in FIG. 1F , a guide track 116 may be provided to guide and stabilize the stack platform 130 as it moves downward under the weight of an extremely large stack. In the preferred embodiment shown in FIG. 1F the guide track 116 is an integral part of a large frame 110 , thereby minimizing complexity and number of parts.
Alternatively, the guide track 116 may be a detachable component available as an upgrade for frames 10 of various sizes.
The hooks 115 can be fashioned in various ways to provide maximum compatibility with different sizes, types, models and brands of copiers. Such ways include interchangeable frames with integral hooks of a desired configuration, or frames with detachable hooks which can be changed according to the configuration required for coupling to a particular copier.
Referring to FIG. 2 , a preferred embodiment is shown of the frame 110 and springs 120 defining a lengthwise opening in one side of the output tray 100 to facilitate operator access for removal of sheets and/or sets from the output tray 100 . The access opening shown in FIG. 2 is on the side of frame 110 opposite the sheet output port, but may be configured to be on any of the three sides not adjacent the copier.
Stack Support Platform Angle Adjusting Shim
Referring to FIG. 3A , a simple wedge-shaped stack support platform angle adjusting shim 131 is shown. Viewed from above, the shim 131 is rectangular. The shim 131 fits through the frame 110 and rests on top of the stack support platform 130 , and is otherwise dimensioned to be compatible with the size of sheets and/or sets to be accumulated in the output tray 100 . Viewed from the front, one side of the shim 131 is substantially higher than the other so that when the shim 131 is placed on top of the stack support platform 130 , either uphill or downhill stacking can be provided according to the orientation of the shim 131 . If horizontal stacking is desired, the shim 131 is not employed and sheets or sets output by the copier rest directly on top of the stack support platform 130 . As shown in FIG. 3B , uphill stacking is accomplished by placing the low side of the shim 131 towards the side of the output tray 100 adjacent the copier and below the copier output port. Downhill stacking is accomplished by reversing the orientation of the shim 131 so that the high side is below the output port and adjacent the copier, as shown in FIG. 3C . The shim 131 can be maintained in position by mechanical interlock with the springs 120 and their mounting points on the stack support platform 130 , the weight of the stack resting on the shim 131 , other fastening means commonly known in the art such as velcro, single- or double-sided tape, glue, screws, clips, etc., or various combinations thereof.
Variable Length Stack Edge Alignment Surface
FIG. 4 shows a side view of a variable length stack edge alignment surface 140 comprised of a belt-like flexible sheet or membrane which unrolls from the top of the output tray support frame 110 in “windowshade” style to provide a smooth alignment surface which does not move relative to the stack. Preferably a single stack edge alignment surface 140 is utilized, being approximately the width of the side of the frame 110 from which it unrolls, but in alternative embodiments two or more “belts” of narrower width may be employed. Although the material of the variable length stack alignment surface 140 is flexible enough to be rolled or curved, the number and arrangement of the springs 120 provide sufficient lateral and longitudinal support so that the material is not deformed beyond a range acceptable for a desired stack edge alignment tolerance.
As shown in FIG. 4 , a single roll of such material for a variable length stack edge alignment surface 140 may be provided, on the side of the frame 110 adjacent the copier. The roll of flexible material for the stack edge alignment surface 140 is positioned sufficiently below the copier output port so as not to interfere with ejected sheets and/or sets, but not so low as to allow sheets and/or sets at the top of the stack to slide out of the output tray 100 . In alternative embodiments, the roll may be located on any one side of the frame 110 , or an additional roll or rolls may be located on any two or three or on all four sides of the frame 110 . The length of the stack edge alignment surface 140 is determined according to the maximum desired stack height or output capacity of the output tray 100 , and will vary according to particular applications.
In the preferred embodiment, one end of the variable length stack edge alignment surface 140 is attached to and wrapped around a roller 141 located adjacent a top edge of the frame 110 , and the other end is attached to the stack support platform 130 . As shown in FIG. 4 , the “windowshade” style variable length stack edge alignment surface 140 , unrolls and re-rolls onto the roller 141 according to the upward and downward movement of the stack support platform 130 responsive to the height and weight of the stack in the output tray 100 . As again shown in FIG. 4 , the spring 120 may be separate from a roller rewind spring 142 provided keep the variable length stack edge alignment surface 140 taught and to cause it to roll back around the roller 141 when the stack support platform 130 rises after being unloaded. Alternatively, the functionality of some of the springs 120 could be incorporated into a roller rewind spring 142 and some of the springs 120 eliminated.
FIG. 5 shows an alternative variable length stack edge alignment surface 140 that moves over a roller 141 located adjacent a top edge of the frame 110 , where one end of the variable length stack edge alignment surface 140 is attached to the stack support platform 130 and the other end is attached to a spring 120 , which in turn is attached to the frame 110 .
FIG. 6 shows an alternative simple, high capacity output tray 100 where the biasing element is a telescoping cylinder 124 that compress as sheets are stacked on the stack support platform 130 . The top of upper end of the cylinder 124 contacts the underside of the stack support platform 130 , while the lower end of the cylinder 124 rests on the floor. In a preferred embodiment, the cylinder 124 is sealed and capable of being pressurized either in the manner of a sealed “air spring” or hydraulically with the addition of a reservoir and pump. The cylinder 124 may be pre-pressurized or “pre-loaded” if desired, so that it will not begin to compress until a desired minimum stack weight is reached. Alternatively, the cylinder 124 may be essentially un-pressurized until compressed as sheets accumulate on the stack support platform 130 .
GENERALITY OF THE INVENTION
The invention has general applicability to various fields of use relating to document production machines. In addition to copiers, the invention may be used for printers, whether stand-alone or networked, fax machines, or any other type of device which outputs sheets or sets of sheets of relatively thin, flexible material.
The foregoing merely illustrates the principles of this invention, and various modifications can be made by persons of ordinary skill in the art without departing from the scope and spirit of this invention. | The invention is relates to a simple, inexpensive high capacity output catch tray for copiers and other document production machines. The output tray automatically increases in capacity as the stack of copies in it accumulates, without external power source or control, while maintaining a relatively constant elevation relative to the copier output port, and automatically returns to its original position when partially or completely unloaded. | 1 |
CROSS RELATED APPLICATION
This application relates to and claims priority to Finnish Patent Application No. 20090039 filed on Feb. 9, 2009, the entirety of which is incorporated by reference.
BACKGROUND OF INVENTION
The present invention relates to a method for generating steam from a black liquor in a digester plant of a chemical pulp mill.
Conventionally, fiberline systems have a chip bin where steaming of wood chips or other cellulose material occurs, liquid is added to form a slurry, followed by pressurization of the slurry (this section is also referred to as the feed system), fed to a treatment vessel or vessels (could be an impregnation vessel, a pre-hydrolysis process or other vessels), followed by a digester (this section is also referred to as the cooking system). Currently, at least one black liquor stream (typically at a temperature of 110-150° C.) is withdrawn from the cooking system. The extracted black liquor stream or streams are used as a source of heat to “pre-heat” white liquor, other black liquor streams, and/or other liquid streams being sent to the feed and cooking systems. The extracted black liquor stream (or streams) is then sent to the pre-evaporation system, e.g., two or more flash tanks where steam is produced from the hot black liquor as the liquor is cooled, typically to temperatures of approximately 95-110° C. At this point, the black liquor is sent to the evaporator system in the recovery area. The flash steam so produced can be used elsewhere in the pulping process. For example, flash steam can be used directly to presteam chips prior to cooking.
The above flashing process, though it has been successfully employed in conventional continuous digesters, has the drawback that the steam produced contains volatile compounds, including sulfur compounds, which are undesirable in the presteaming of wood chips. Typically, wood chips are steamed at atmospheric pressure, or slightly above, such that the residual gases not absorbed by the wood chips must be collected and treated. The treatment typically is carried out by combustion in a mill's noncondensable gas (NCG) system. However, this collection and treatment system becomes particularly significant when the steam used contains volatile compounds, including sulfur compounds, which have undesirable environmental impact, including noxious odor. It is therefore preferable to use a source of steam which minimizes or eliminates the introduction of volatile compounds to the steaming process.
Steam is also needed for heating the fibrous material to the cooking temperature in the vapor phase of the digester. In the known systems medium-pressure steam from the mill's turbine plant is typically used for this purpose. Due to the cost of energy, any further improvement to the energy efficiency of the chemical pulp mill is needed.
U.S. Pat. No. 4,944,840 discloses a process in which waste liquor discharged from a digester is evaporated in multiple evaporation stages. Vapors generated in the evaporation stages are directly introduced to the impregnation and cooking zones in a digester for heating the fibrous material.
SE patent 453,673 reveals a method in which a fibrous material is cooked with a cooking liquor while passing steam into the top of the digester where the fibrous material and the liquor flow continuously and are separated, the cooking liquor being recycled. According to the method, a part of the cooking liquor is extracted from the digester and led to a steam converter for production of steam. The steam is fed to the digester in order to heat the fibrous material introduced to the desired temperature.
A system is revealed in U.S. Pat. No. 6,722,130 for the generation of pure steam from black liquor. The pressure of the black liquor is first reduced in order to produce a second black liquor at a higher concentration and black liquor vapor, which is condensed to form a condensate. The condensate is heated by the first black liquor and expansion evaporated to produce pure steam which is used in a chip bin.
A system is revealed in U.S. Pat. No. 6,176,971 for the generation of pure steam to be used in the chip bin. Substantially clean useable steam is produced from a hot spent treatment liquor (e.g. black liquor) by passing the spent liquor to a reboiler, and then pressurizing (e.g. with an eductor, fan, or compressor) the clean steam discharged from the reboiler. The quantity of clean steam produced is increased by placing under negative pressure the pure steam side of the steam converter in the steam converter with a steam-driven ejector. The reduced pressure of the pure steam side ensures that more heat can be withdrawn from the black liquor, which in itself gives a greater quantity of steam, while the supply of steam to the ejector also contributes to the delivery of greater quantities of steam. In this case, however, the steam vapor formed consists of a mixture of pure steam that has been expelled from the process fluid and steam that has been taken from the steam supply network of the mill for driving the ejector.
A further process for the generation of pure steam is revealed in U.S. Pat. No. 6,306,252 for use in the chip bin, where the black liquor from the digester is led through a heat exchanger in which pure process water is heated, after which the pressure of the heated process water is reduced, such that pure steam is generated.
US Patent Application Publication 2007/0131363 discloses a method which comprises generating black liquor in a digester system, sending the black liquor to an evaporator system without using any pre-evaporator system, flashing the black liquor in the evaporator system to yield steam, and using at least some of the steam for chip steaming in a chip bin and/or for supplying in-direct heat exchangers in the digester system for pre-heating white liquor and/or filtrates for use in the digester system.
WO 2007073333 discloses a system and a method for the generation of steam in a digester plant for the production of chemical cellulose pulp. The pressure of hot, pressurized black liquor from a digester is reduced in a first step for the formation of black liquor steam that is used for the steam pre-treatment of the chips in a second pre-heating step. Pure steam for the steam pre-treatment of the chips in a first preheating step is formed through re-heating the black liquor the pressure of which has been reduced before a final subsequent pressure reduction, where the increased quantity of black liquor steam is led to a steam converter for the generation of pure steam.
WO 2008/057040 concerns a method which comprises an impregnation vessel in which to impregnate the chips, which chips are then fed to a subsequent digester vessel in a transfer fluid. A black liquor withdrawal is taken from the digester, which withdrawal is led to the bottom in order there to heat the chips before they are fed out from the impregnation vessel. A withdrawal of the transfer fluid is taken from the top of the digester and led to a position in order there to act as impregnation fluid in the impregnation vessel. At least a portion of the transfer fluid that was withdrawn from the top of the digester passes through an indirect heat exchanger, in which the transfer fluid withdrawn from the top of the digester at a temperature exchanges heat indirectly with a first fluid for the production of steam from the first fluid. The steam that is produced is then led to a steam pre-treatment position, upstream of the impregnation process, in order to heat the chips at said steam pretreatment position.
The known solutions provide different systems for producing cleaner steam for heating needs in the digester plant and for improving the energy economy of the pulp mill.
SUMMARY OF INVENTION
A method and system have been invented for the production of clean steam for steam pre-treatment of wood chips by utilizing the heat of black liquor and for the production of steam from black liquor for heating fibrous material in a digester. Steam and vapor is generated from black liquor so that the treated black liquor has better properties as regards the further treatment in the recovery area of the pulp mill. Further, the energy economy of the whole pulp mill can be improved with the method and system disclosed herein.
The present invention, in one embodiment, relates to a method for generating steam in a digester plant of a chemical pulp mill, in which method
a) black liquor is produced in the digester system,
b) a first stream of black liquor is extracted from the digester and evaporated using fresh steam as a heating medium to generate vapor and evaporated black liquor having an increased dry solids content,
c) the vapor from the evaporation in step b) is used for heating fibrous material in the digester,
d) a second stream of black liquor extracted from the digester is flashed to generate flashed black liquor and flash vapor, which is introduced to at least one heat exchanger, preferably a reboiler, into an indirect heat exchange contact with a clean evaporable liquid to produce clean steam,
e) the clean steam from step d) is used for steaming chips, and
f) the flashed black liquor from step d) is led to further evaporation.
Step d) may be practiced so that the evaporated black liquor from step b) and the second stream of black liquor extracted from the digester are combined before or during the flashing. The evaporated black liquor from step a) may have a higher dry solids content than the flashed black liquor from step d).
The clean evaporable liquid in step d) may be evaporator condensate, demineralized water, boiler feed water or clean enough water fraction.
The fresh steam may be condensed in the evaporation in step b) and fresh steam condensate thus produced is led to the mill's recovery boiler plant where it is used as feed water.
Step f) may be practiced so that the flashed black liquor from step d) is led together with the evaporated black liquor from step b) to further evaporation.
An embodiment of the present inventive method includes:
a) Required vapor to the digester top is produced by evaporating extraction black liquor in one or multiple stage evaporator(s) using fresh steam as a heating medium, and
b) Odor-free steam for the steam pre-treatment of chips is generated by flashing extraction liquor and condensing the flash vapor in a re-boiler/s which exchanges heat indirectly in a reboiler/s with the condensate or pure enough water in order to produce odor-free steam. The steam that is produced is then led to a steam pre-treatment position to a retention and/or steaming vessel.
SUMMARY OF THE DRAWINGS
FIG. 1 shows schematically a system for generating steam in a digester plant and for treating black liquor.
DETAILED DESCRIPTION
FIG. 1 illustrates a system for generating steam in a digester 5 a plant and for treating black liquor so that the heat efficiency of the cooking process is improved. The fiberline system comprises a chip bin 10 where steaming of wood chips or other cellulose material occurs with steam from line 2 (a line is a conduit such as a pipe), liquid is added to form a slurry, followed by pressurization of the slurry (this section is also referred to as the feed system) followed by a continuous digester 5 a (this section is also referred to as the cooking system). Before the digester 5 a , the slurry may be optionally fed to and treated in a treatment vessel or vessels (could be an impregnation vessel, a pre-hydrolysis process or other vessels, not shown). The slurry of chips and cooking liquid is fed via line 3 to the top of the digester 5 a Only those components that are important for the invention are shown in the drawing, and other types of chips steaming or feeding or digester 5 a circulations can, of course, be present in the digester 5 a system. At least one black liquor stream (typically at a temperature of 120-160° C. and at a dry solids content of 12-17%), is withdrawn from the digester 5 a through line 4 and introduced further through line 5 into an evaporator 6 . Optionally, a pressurized fiber filter 7 can be located in the line 5 between the digester 5 a and the evaporator 6 to allow the removal of fiber from the black liquor stream to a level of about 40 ppm leaving the filter. The fiber material removed from the filter would be in the form of a slurry to be returned to the digester 5 a or feed system.
A fiberline system for production of chemical cellulose pulp is disclosed herein comprising a chip bin 10 where steaming of a cellulose material occurs using clean steam from a steam line 2 , a feed system where liquid is added to the cellulose material to form a slurry, followed by pressurization of the slurry, optionally one or more treatment vessels where the slurry is treated prior to cooking, and a continuous digester 5 a for cooking the slurry, said digester 5 a comprising a first line 4 , 5 for withdrawing at least one black liquor stream from the digester 5 a and feeding it into at least one evaporator 6 , wherein the black liquor is evaporated to generate secondary vapor and evaporated black liquor, and a second line 14 , 13 for withdrawing at least one black liquor stream from the digester 5 a and feeding it to a flash tank 15 , wherein the pressure of the liquor is decreased to produce flash vapor and flashed black liquor, wherein the evaporator 6 further having a steam supply line 8 for supplying fresh steam to heat the slurry, a steam withdrawal line 11 for directing secondary vapor generated in the evaporator 6 to the digester 5 a inlet, where said steam is used as heating steam for heating fibrous material in the slurry, a condensate line 12 for withdrawing condensated fresh steam from the evaporator, and a line for withdrawing evaporated black liquor from the evaporator 6 , optionally feeding it to a flash tank 15 , wherein the pressure of the liquor is decreased to produce flash vapor and flashed black liquor, said flash tank further 15 having a line 18 for withdrawing flashed black liquor and feeding it to the evaporation plant of the mill, and a vapor line 16 for directing flash vapor to a reboiler 17 , where the vapor produces clean steam by indirect heat exchange with a clean, evaporable liquid, said reboiler 17 further having a steam line 2 for withdrawing clean steam and directing it to the chip bin 10 , a line 21 for supplying clean, evaporable liquid to the reboiler 17 , and one or more lines 19 , 20 for withdrawing foul condensate and concentrated non-condensable gases from the reboiler 17 .
The line for withdrawing evaporated black liquor from the evaporator 6 and either said first line 4 or said second line 14 , 13 for withdrawing at least one black liquor stream from the digester 5 a , or both, may be combined for feeding these liquids to said flash tank 15 , or are individually directed to said flash tank 15 .
The condensate line 12 for withdrawing condensated fresh steam from the evaporator 6 may direct the evaporator condensate to the line 21 for supplying clean, evaporable liquid to the reboiler 17 .
The evaporator 6 and the flash tank 15 may be arranged to provide evaporated black liquor having a higher dry solids content than the flashed black liquor.
The condensate line 12 for withdrawing condensated fresh steam from the evaporator 6 may direct the fresh steam condensate as feed water to a recovery boiler plant in the mill.
A pressurized fiber filter 7 may be located in the first line 5 between the digester 5 a and the evaporator 6 to allow the removal of fiber from the black liquor stream.
The evaporator 6 may be a falling film evaporator which has a plurality of plate or tube heat exchange elements 9 , along the outer surfaces of which the black liquor discharged from the digester 5 a is arranged to flow.
The at least one evaporator 6 may be constituted by two or more evaporators or a multistage evaporator generating vapors having different temperatures, wherein vapor lines are directing said vapors to the digester 5 a ( 5 a ) for heating the fibrous material.
The black liquor may be evaporated in the evaporator 6 . Fresh steam (the pressure of steam is typically 6-17 bar (g) and the steam may be extraction steam from a turbine) is supplied via line 8 to heat exchange elements 9 . The evaporator is typically a falling film evaporator which has a plurality of plate or tube heat exchange elements. The black liquor being evaporated, in other words, the black liquor discharged from the digester 5 a , is caused to flow along the outer surfaces of the heat exchange elements 9 . The secondary vapor generated in the evaporator 6 is directed through line 11 to the top of the digester 5 a to be used as heating steam. The vapor has typically a temperature of over the cooking temperature, so that the fibrous material is heated to the cooking temperature by the vapor, which is led through the vapor inlet opening of the digester 5 a which communicates with the vapor space of the evaporator 6 . The black liquor can also be evaporated in two or more evaporators or in a multistage evaporator, and the vapors having different temperatures are generated and may be used for heating the fibrous material in the digester 5 a . The dry-solid content of the black liquor is increased as much as the total evaporation shall be in the evaporator(s). The fresh steam is condensed in the evaporator 6 , and fresh steam condensate thus produced is pure and it can be led via line 12 to the mill's recovery boiler plant where it can used as feed water without any purification process.
The quantity of the black liquor to be evaporated depends on the steam flow needed in the digester 5 a . It is not advantageous to generate excess black liquor vapor in the evaporation by means of fresh steam, which would worsen the heat economy of the mill.
By using the steam from the black liquor evaporator in the digester 5 a for heating fibrous material, a better heat economy is achieved, because the black liquor is not diluted by adding fresh steam in the digester 5 a.
Hot black liquor extracted from the digester 5 a typically at a temperature of 120-160° C. and at a dry solid content of 12-17%, is also led via lines 14 , 13 to a flash tank 15 where the pressure of the liquor is decreased to produce flash vapor having typically a temperature of 100-130° C. and flashed black liquor, the dry solid content of which can be increased by 2-4% in flashing. Preferably one or more black liquor streams withdrawn from the digester 5 a through an outlet or outlets and through lines 4 , 14 is/are combined with the evaporated black liquor from the evaporator 6 . The flow (kg/s) of the evaporated black liquor is typically smaller than that of the black liquor going directly from the digester 5 a to the flash tank 15 . It is possible to send the evaporated black liquor directly to the mill's evaporation plant, but it is preferable to mix it with unevaporated black liquor to be able to utilize all available heat at a reasonable temperature level. The flashed black liquor is sent via line 18 to the evaporation plant of the mill where the black liquor is concentrated to a high dry solids content before combustion in a recovery boiler.
The energy of the flash steam in line 16 is recovered in a reboiler 17 where the steam is passed in an indirect heat exchange relationship with volatile-compound-free “clean” liquid to heat the water above its boiling point or flash point to produce clean, volatile compound-free, odor-free steam. The clean liquid is fed via line 21 . It may typically be evaporator condensate, demineralized water, boiler feed water or clean enough water fraction. The clean steam produced in the reboiler has substantially less noncondensable gases than steam produced by direct black liquor flashing. The clean steam in line 2 is preferably used for pretreating wood chips with steam, e.g. in the chip bin 10 . When used to treat chips, since the steam does not introduce volatile compounds to the presteaming process, the load of the volatile compounds which must be collected and treated by a mill's NCG system is reduced.
The flash vapor from the black liquor flash tank 15 contains volatile compounds, such as sulfur compounds. These compounds are passed to a foul condensate and to a concentrated noncondensable gas (CNCG) stream which are generated in the reboiler. The foul condensate is sent from the reboiler via line 19 to the evaporator plant where it is treated in a way known per se. The CNCG stream is led via line 20 to a condenser, e.g. digester 5 a auxiliary condenser (not shown).
The potential advantages of the system and method disclosed herein include:
a) Mill-wide heat economy will improve, as the dry solid content of the extraction liquor which is led to the evaporation plant of the mill will increase. Increased dry solid content is a consequence of flashing the extraction liquor and the fact that there is no direct steam usage into the digester 5 a . The steam consumption and capacity demand will decrease in the evaporation plant.
b) Investment cost savings of the evaporation plant decreases due to the lower capacity demand.
c) Fresh steam condensate return increases and thus the mill-wide steam consumption decreases.
d) Methanol recovery of the mill-wide system is improved, as the first evaporated fractions from the black liquor shall be condensed in dedicated heat exchangers (evaporator and reboiler).
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | A method for generating steam in a digester plant of a chemical pulp mill including: producing black liquor in the digester plant, extracting a first stream of black liquor from the digester; generating vapor by evaporating the first stream of black liquor by heating the first stream with fresh steam; heating fibrous material in the digester with the generated vapor from the evaporated first stream of black liquor; extracting a second stream of black liquor from the digester; flashing the second stream of black liquor to generate flashed black liquor and flashed black liquor vapor; introducing the flashed black liquor vapor to at least one heat exchanger to indirectly heat a clean evaporable liquid to produce clean steam from the clean evaporable liquid; and steaming, with the clean steam produced in the at least one heat ex-changer, cellulosic feed material before feeding the cellulosic feed material to the digester plant. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Priority is hereby claimed to provisional application Ser. No. 60/957,802, filed Aug. 24, 2007, which is incorporated herein
FIELD OF THE INVENTION
[0002] The invention is directed to a device for clearing clogged plumbing. More specifically, the invention is drawn to a plunger with a replaceable, disposable, sanitary cover.
BACKGROUND OF THE INVENTION
[0003] Plungers have been used since time immemorial to unclog jammed plumbing, such as sinks and toilets. It is inevitable that every plunger put into use will eventually come into contact with human waste. After a conventional plunger has been used to free a clog in a toilet, the user is faced with the unappealing task of cleaning the plunger of residual matter and returning the plunger to wherever it is stored when not in use. This clean up problem has bedeviled the users of plungers for as long as plungers have been in existence. Additionally, the design of a plunger head requires that it perform like a bellows in order to function properly. Thus, plunger heads in general have a tendency trap matter therein, and make effectively cleaning the plunger very difficult. This difficulty is exacerbated by natural human aversion to having human excrement contacting human hands.
SUMMARY
[0004] The invention is directed to a plunger construction comprising: a handle, a plunger bell with an inner bell surface, and an elongated tubular sheath. The sheath at least substantially encases the handle and plunger bell, and the sheath is at least partially secured to the inner bell surface.
[0005] The sheath may be comprised of any suitable flexible material, such as a thermosetting or thermoplastic polymer film.
[0006] The plunger construction may optionally further comprise holding tabs on the sheath that secure a portion of the sheath to the handle. It is preferred that the sheath is at least partially secured to the inner bell surface. This can be done by any suitable fastener, such as a peel and stick-type adhesive, contact cement, hook and loop fasteners, etc.
[0007] In one embodiment of the invention, the handle is comprised of a fixed handle portion and a slidable handle portion. The fixed handle portion has one end attached to the plunger bell and the other end slidably engaged to the slidable handle portion. The slidable handle portion is configured to collapse upon the fixed handle portion in a collapsed position and extend from the fixed handle portion in an extended position. It is preferred that the fixed handle portion and the slidable handle portion are hollow and form a handle cavity and the slidable handle portion is slidably engaged to the fixed handle portion by an airtight seal. In this version of the invention there is an opening defined in the inner bell surface leading to the handle cavity, and the handle is configured so that extending the slidable handle portion creates a vacuum at the opening in the inner bell surface which secures the sheath against the inner bell surface. The plunger may further comprise a one-way air valve contained in the slidable handle portion. The one-way air valve is configured to allow the handle to collapse in the collapsed position when the plunger bell is covered by the sheath. The plunger may include a lock configured to secure the slidable handle portion in the extended position, such as a pop-up latch mounted on the fixed portion that engages a corresponding hole in the slidable handle portion or twist-and-lock handle.
[0008] In another version of the invention, the fixed handle portion and the slidable handle portion are hollow and form a handle cavity. An opening is defined in the inner bell surface leading to the handle cavity. An attaching device is disposed within the handle cavity and has a first end connected to the slidable handle portion and a second end extending through the opening in the inner bell surface and secured to the sheath. In this fashion, the sheath is removably fixed to the plunger.
[0009] The plunger may also comprise a spring-pressurized piston that is configured to spring upwards to secure the sheath against the inner bell surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows a cross-sectional view of a slidable plunger handle that utilizes vacuum pressure as a securing means, a standard bell shaped plunger bell, and a protective sheath.
[0011] FIG. 2 shows a cross-sectional view of a fixed plunger handle utilizing adhesive as a securing means, a bellows-type plunger bell, and a protective sheath.
[0012] FIG. 3 shows a cross-sectional view of a slidable plunger handle that utilizes a hook mechanism as a securing means, a standard bell-shaped plunger bell, and a protective sheath with a loop.
DETAILED DESCRIPTION
[0013] The present invention is directed to a plunger with a replaceable cover 24 that allows the user to clean the plunger quickly and easily. The device is dimensioned and configured substantially to encase the plunger, as well as the user's hands, thereby preventing the plunger and user from directly contacting any matter in a clogged sink, toilet bowl, or other plumbing fixture. Once the job is complete, the encasement that surrounds the plunger and the user's hands is easily removed and discarded.
[0014] One version of the invention is depicted in FIG. 1 . FIG. 1 shows a cross-sectional view of the plunger encased in a replaceable cover or encasement 24 . As depicted in FIG. 1 , the plunger according to the present invention has a resilient, flexible bell 22 at the bottom, attached to a collapsible handle 20 . The handle 20 comprises two parts; a fixed handle portion 14 having one end attached to the bell 22 , and the other end 10 being slidably engaged with the fixed handle portion 14 . The sliding handle portion 10 is generally hollow and connected to the fixed handle portion 14 in such a manner that it may be extended upward away from the bell, to a stop point, and then locked in place by twisting. In short, the sliding handle portion 10 and the fixed handle portion 14 are dimensioned and configured to slidingly engage, relative to each other, and are extendible from a first collapsed position to a second extended position, as shown in FIG. 1 . The handle portions are sealed where they slidingly engage to provide an air-tight seal 12 around the circumference of the fixed portion of the handle, thereby creating a vacuum at the opening 17 to the fixed handle portion 14 that engages the bell 22 . Thus, as shown in FIG. 1 , the sliding handle portion 10 may include an air valve 19 to allow the handle to collapse even when the bell end is covered by the sheath 24 .
[0015] An elongated sheath 24 made of any suitably flexible material, preferably a thermosetting or thermoplastic polymer film, most preferably a polyethylene film, is placed over the plunger bell 22 and handle 20 . The sheath 24 is closed on the bell end to receive the plunger bell 22 , and open on the other end to allow access to the handle 20 by the user. The handle end of the sheath has a pair of holding tabs 18 extending inside the sheath. These tabs may be used to secure a portion of the sheath 24 to the handle 20 after the sheath has been pulled over the plunger and the user's hands.
[0016] The bell end of the sheath is designed to have a portion that may be pulled into the plunger bell. This portion may be secured by utilizing the handle 20 to create a vacuum in the bell 22 , thereby pulling the sheath 24 up against the inner bell surface 16 . By locking the slidable handle portion 10 in the extended position the vacuum pressure may be maintained, thereby securing the sheath 24 until the handle 20 is unlocked and released. Once the plunger is no longer needed, the slidable portion 10 of the handle is unlocked and slid towards the bell 22 , thereby releasing the vacuum that was securing the sheath 24 against the inner bell surface 16 and placing the handle in the collapsed position. The sheath 24 is then folded upon itself down the handle 20 and over the plunger bell 22 , thereby inverting the sheath 24 and allowing the user to avoid contact with the outer surface of the sheath 24 that was exposed to the toilet water.
[0017] Another version of the invention is depicted in FIG. 2 . FIG. 2 depicts a cross-sectional view of a plunger encased in a replaceable cover 30 . The plunger construction is comprised of a solid handle 26 with a bellows-type plunger bell 28 and an elongated sheath 27 . The sheath 27 has an open end for inserting the plunger and a closed end to cover the bell 28 . The sheath 27 is preferably an elongated piece of flexible material (as noted earlier) that tapers out as the open end approaches the closed end, with an adhesive portion 32 inside the closed end for adhering the sheath 27 to the inner bell surface 16 . The sheath 27 is placed over the plunger bell 28 with the adhesive portion exposed (for example, removing the paper from a peel-and-stick-type adhesive). The adhesive portion is affixed to the inner bell surface 16 and the sheath 27 is extended over the handle 27 . Once the plunger cover 30 is no longer needed, the sheath is then folded upon itself down the handle and over the plunger bell 28 , thereby inverting the sheath 27 and allowing the user to avoid contact with the outer surface of the sheath that was exposed to the toilet water. The sheath may then be discarded, leaving a clean plunger.
[0018] The aforementioned embodiments are merely a few versions of the invention, and it is contemplated that numerous additions and modifications can be made. The following are additional examples. It is understood that these examples are not to be construed as describing the only additions and modifications to the invention and that the true scope of the invention is defined by the claims included herein.
[0019] There are several methods contemplated for securing the sheath to the inner bell surface. One such method contemplated is illustrated in FIG. 3 . Here, a hook 26 may extend down the slidable handle assembly 20 , wherein when the slidable handle 10 is depressed, the hook exits the handle into the bell area. The flexible sheath cover includes a loop 34 for attaching to the hook. Once the sheath loop 34 has been hooked, the handle 20 is slid upwards, thereby pulling the hook 26 back into the handle 20 and thereby securing the sheath 24 by pulling it tight against the inner bell surface 16 . Other means of controlling the hook assembly have been contemplated, for example, a spring-urged piston extending downwards with a hook on the end that may be pushed further inside the handle cavity to latch the sheath loop 34 and then allowed to spring upwards to pull the hook 26 and loop 34 connection tight. Further, the sliding handle portion preferably locks into a fixed position with the fixed handle portion 14 by twisting, although, several other methods may be used; for example, a pop-up latch mounted on the fixed portion that snaps into a hole in the slidable portion thereby locking it.
[0020] In the fixed handle configuration, several means of securing the sheath to the inner bell surface are contemplated. The use of a peel-and-stick-type adhesive 32 is preferred, although various other securing means would be acceptable, for example a hook-and-loop fastener configuration, or contact cement.
[0021] The sheath material may be polyethylene, but may also be made of various other plastic polymers or composites. The sheath may be elastic or non-elastic and of single or varying thicknesses and size. The sheath may have a circular, square or another shape cross-sectional configuration. The sheath preferably tapers out moving from the handle end towards the bell end, but may have a continuous diameter as well. Additionally, it is contemplated that one or more sheaths may be stored inside the plunger handle or bell for easy access and convenient storage. The stored sheaths may further be attached in a continuous manner to allow for sequential dispersion from the handle. The plunger bell for any embodiment may be of various shapes and sizes and may attach to the handle by various means such as the male and female threaded connection typically found in plungers. | Disclosed is a plunger including, in combination, a handle, a plunger bell with an inner bell surface, and an elongated tubular sheath, wherein the sheath at least substantially encases the handle and plunger bell, and the sheath is at least partially secured to the inner bell surface. | 4 |
FIELD OF THE INVENTION
The invention concerns a rinsing or flushing apparatus and process in a simulated moving bed separation apparatus comprising at least two circulation lines connecting the distribution plates to external fluids.
BACKGROUND OF THE INVENTION
The prior art is particularly illustrated in European patents EP-A-0 688 590, EP-A-0 415 822, EP-A-0 075 611 and U.S. Pat. No. 5,156,736.
In simulated moving bed separation processes such as those carried out in the "Sorbex" series of processes, among them the PAREX®, MOLEX®, SAREX®, OLEX®, and EBEX® processes, a plurality of beds are used which are localised in one or two adsorption columns. Each distributor plate situated between two consecutive beds is connected to the exterior by means of a single line leading into a rotary valve which brings each of the beds in succession into communication with each of the streams entering or leaving the adsorption section in sequence. Such streams comprise:
1) the feed to be separated constituted by a mixture of at least two products:
A the most adsorbed in the beds and B the least adsorbed, or retarded, in the beds;
2) the solvent or desorbent which elutes or desorbs the constituents of the feed;
3) the extract, constituted by a mixture of the most adsorbed product (A) and the desorbent;
4) the raffinate, constituted by a mixture of the least adsorbed product (B) and desorbent;
5) the in flush, or in rinse, constituted by a mixture of extract and desorbent, which can flush the slug of feed trapped in the common line after the feed has been introduced into the adsorber into the interior of the adsorber;
6) the out flush, or out rinse, constituted by a mixture of extract and desorbent, which draws the slug of extract which is trapped in the common line after the extract has been extracted from the adsorber toward the exterior. The in flush and out flush flow rates are equal, and a pump places the out flush stream in communication with the in flush. The flush flow rate is calculated so that the volume of the longest line connecting the rotary valve to the furthest bed is flushed 2 to 3 times during a permutation period;
7) the secondary flush can be constituted either by desorbent, or by extract which is depleted in desorbent. Its aim is to flush the extremity of the common line so as to flush any impurity which may have lodged there by diffusion or exchange into the interior of the adsorber just before extracting the extract.
The disadvantage of this type of process is that each of the common lines must be flushed between introducing the feed and extracting the extract and between extracting the extract and introducing the desorbent, if a high purity of constituent A is desired in the extract. The flush flow rate linked to the highest volume of flushed line is far from negligible in the light of the feed flow rate, and it has the effect of causing the system to operate slightly off the optimum flow rate in the different zones.
A further disadvantage of coupling by means of the rotary valve of the in flush and out flush is that this requires a pump, a flow meter and a flow rate regulating valve since during a cycle, the pressure of the out flush can easily be lower than the pressure of the in flush.
Further, the flow rate regulating system in the in flush, out flush loop is not particularly suitable for a programmable flow rate which varies, for example, from zero over a certain portion of the period to a certain reference value during another portion of the period, thus allowing effective flushing with a minimum displaced volume.
An alternative technique which is used in the Eluxyl process, for example, consists of connecting each distributor plate located between two consecutive beds to the exterior by at least two distinct circulation or distribution lines.
It also contains a distinct on-off valve per distributor plate and per principal entering or leaving stream (desorbent, extract, feed, raffinate).
In principle, if one of the two lines is used for "clean" fluids (desorbent or extract), and the other is used for "dirty" fluids (feed or raffinate), flushing each of the two common lines becomes superfluous. If not just two lines dedicated to "clean" and "dirty" fluids are used, but four distinct lines are used each connecting each of the principal streams to the distributor plate, flushing such lines is in principle of no use.
However, each of such lines leads into the principal stream circulating from one bed to the next and the extremity of the two lines (dedicated to clean and to dirty fluids) or the extremity of the four lines dedicated to extract, raffinate, feed or desorbent may be contaminated by exchange or diffusion with the principal fluid. When the purity and yield are to be maximised, such contamination becomes deleterious.
SUMMARY OF THE INVENTION
The aim of the invention is thus to overcome this disadvantage by carrying out flushes where the volumes or flow rates are as small as possible and in any case lower than those of processes using a rotary valve and a single line which is common to the four principal streams per bed.
A second aim of the invention is to minimise the flushing volumes by increasing their efficiency, by flushing at a very high flow rate for only a portion of the period.
More precisely, the invention concerns a counter-current or co-current simulated moving bed separation apparatus which is combined with a line flushing apparatus which transports various fluids. In more detail, there is provided a simulated moving bed separation apparatus comprising a plurality of interconnected chromatographic columns or column sections (2, 4, 6), a fluid distributor plate (3) between each column section, at least two (10, 30) and at most four (10, 20, 30, 40) distinct circulation lines connected to the distributor plate (3), each circulation line being connected to a different line selected from two supply lines (100, 300) by which the feed and the desorbent enter and two extraction lines (200, 400) by which a fluid containing the desired product and a fluid containing the unwanted product or products leave; in which a first circulation line (10) is connected to two lines (100, 200) in which the desorbent and the fluid containing the desired product circulate respectively, a second circulation line (30) is connected to a feed supply line (300) and a third circulation line is connected to an extraction line for fluid containing the unwanted product (400); or in which a first circulation line is connected to two lines (300 and 400) in which the feed and the fluid containing the unwanted product or products respectively circulate, a second circulation line is connected to a desorbent supply line (100), and a third line is connected to a line for extracting fluid containing the desired product (200); or in which a circulation line (10) is connected to two lines in which the desorbent (100) and the fluid containing the desired product (200) respectively circulate, and the other circulation line (30) is connected to two lines in which the feed (300) and the fluid containing the unwanted product or products (400) circulate respectively. The apparatus is characterized in that the line (10) for circulating the fluid containing the desired product comprises a flushing line (250) for a secondary incoming fluid (desorbent, fluid containing the desired product or fluid containing the desired product depleted in desorbent) or for an outgoing fluid (250) (mixture of desorbent and fluid containing the desired product).
At least one other of the circulation lines (30) can comprise a flushing line (350) for a fluid (desorbent) entering the distributor plate or for a fluid (350) leaving the distributor plate (feed, fluid containing the unwanted products).
In a first variation, the fluid in flush line (250 or 350) comprises at least one pressurised chamber or a pump (101 or 253) for supplying said fluid respectively connected to a flow rate regulation means (351, 352 or 256, 257, FIG. 1).
In a second variation, the fluid out flush line (350 or 250) comprises a flow rate regulation means (352, 351 or 256, 257).
The invention also concerns a process using the apparatus. In more detail, a simulated moving bed separation process is provided which is carried out in a separation zone or adsorber comprising a plurality of interconnected columns or column sections, a fluid distributor plate between each column section, at least two (10, 30) and at most four (10, 20, 30, 40) distinct circulation lines connected to the distributor plate, each line being connected to a different line of the four lines containing the four principal streams (fluid containing the desired product, fluid containing the unwanted product, feed, desorbent); in which a first circulation line (10) is connected to two lines (100, 200) in which the desorbent and the fluid containing the desired product circulate respectively, a second circulation line (30) is connected to a feed supply line (300) and a third circulation line is connected to an extraction line for fluid containing unwanted product (400); or in which a first circulation line is connected to two lines (300 and 400) in which the feed and the fluid containing the unwanted product or products respectively circulate, a second circulation line is connected to a desorbent supply line (100), and a third line is connected to a line for extracting fluid containing the desired product (200); or in which a circulation line (10) is connected to two lines in which the desorbent (100) and the fluid containing the desired product (200) respectively circulate, and the other circulation line (30) is connected to two lines in which the feed (300) and the fluid containing the unwanted product or products (400) circulate respectively. The process is characterized in that the line (10) containing the fluid containing the desired product is flushed at least once with a secondary fluid entering each distributor plate or by a fluid leaving each of said plates during at least a portion of a period of time between two successive permutations of the principal supply lines and the principal extraction lines, or during the totality of said periods, the secondary fluid being selected from the group formed by the desorbent, the fluid containing the desired product and the fluid containing the desired product freed of at least a portion of the desorbent.
In one feature of the process regarding the lines for the "clean" fluids, the line (10) containing the fluid containing the desired product is flushed by the secondary fluid which is of substantially the same composition during at least a portion of the period, said flushing being sequential, one plate at a time, all of the plates being flushed successively during the course of one cycle.
Said line can be sequentially flushed by the secondary fluid, downstream of the extract extraction and upstream of the feed supply if the desired product is in the extract and downstream of the raffinate and upstream of the desorbent if the desired product is in the raffinate.
Said line (10) containing the fluid containing the desired product can be flushed by the fluid containing the desired product or the desorbent or said fluid depleted in desorbent, upstream of the feed supply for a portion of the period then downstream of the extract extraction during a further portion of the period, the two positions thus defined being distinct, if the desired product is in the extract.
In a variation, said line is continuously flushed by the secondary fluid over all of the plates at once during all of the periods of the cycle.
Further, the lines containing a "dirty" fluid (for example feed or raffinate) can also be flushed.
Thus in a first variation, the line (30) containing the fluid containing the unwanted product or products is sequentially flushed at least once with desorbent entering the distributor plate between the extract extraction and the feed supply during at least a portion of the period, preferably during the entire period, when the desired product is in the extract.
In a second variation, the line containing the fluid containing the unwanted product or products is sequentially flushed at least once with the fluid contained in the desorption zone for the desired product which leaves a distributor plate between the desorbent supply and the extract extraction, preferably near the desorbent supply, during at least a portion of the period.
Finally, in a third variation, the lines containing the unwanted product or products from all of the distributor plates are continuously flushed using the fluid contained in the adsorber.
In a further characteristic of the invention, when the distributor plate comprises three or four circulation lines, the line transporting the desorbent (100) can be flushed by desorbent (line 150).
The line containing the fluid containing the desired product can be flushed with a ratio of the flushing fluid flow rate to the feed flow rate which is in the range 0.005 to 0.4, advantageously in the range 0.02 to 0.15, and preferably in the range 0.04 to 0.08.
The same ratio can be used for flushing the line containing the fluid containing the unwanted product.
The invention will be better understood from the figures which schematically show embodiments of the invention, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the flushing apparatus when each fluid distributor comprises two circulation lines (10 and 30);
FIG. 2 shows a flushing apparatus when each distributor is connected to four fluid circulation lines (10, 20, 30, 40).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A simulated moving bed separation unit is constituted by at least one column 1 separated into a plurality of beds or sections 2, 4, 6. . ., the number of beds being in the range 4 to 24. Each bed is filled with an adsorbent, for example an X or Y zeolite exchanged with a group IIa cation and a group Ia cation, when para-xylene is to be separated from a C 8 aromatic cut.
Apart from the bed located at the lower extremity of each column, each bed is separated from the bed immediately below it by a distributor 3, 5 . . . . This distributor is connected to the exterior of the column by either 2 circulation lines (10 and 30), see FIG. 1, or by 4 circulation lines (10, 20, 30, 40), see FIG. 2.
Referring to FIGS. 1 and 2, a desorbent line 100 supplies each bed via valves 21a, 61a. Desorbent is successively sent to each bed via line 100 by means of a pump 101 and its flow rate is precisely regulated by means of a flow meter 102 and a control valve 103.
An extraction line 200 serves each of the beds via valves 22a, 62a. The extract is successively extracted from each bed at a controlled flow rate via line 200 by means of a flow meter 201 and valve 202 then directed to distillation column 203 where para-xylene, for example, is extracted overhead via line 206 while desorbent constituted essentially by para-diethylbenzene is extracted via line 205 before being returned to pump 101. This column also comprises an extraction plate 204 for extracting an extract which is depleted in desorbent.
A feed line 300 serves each bed via valves 41a, 81a. The feed is successively sent to each bed via line 300 by means of a pump 301 and its flow rate is precisely regulated by means of a flow meter 302 and a control valve 303. Raffinate is successively extracted from each bed under controlled pressure via line 400 by means of control valve 401 and pressure sensor 402 located on the column. It is directed to a distillation column 403 where a mixture of paraffins and naphthenes, ethylbenzene, meta-xylene and ortho-xylene, for example, is extracted overhead via line 405 while the desorbent constituted essentially by para-diethylbenzene is extracted via line 404 towards pump 101.
Referring to FIG. 1 alone, the distributor plates communicate with the exterior via two lines: 10 and 30 for plate 3, 50 and 70 for plate 5, and so on. Lines 10, 50 lead into lines 21, 22 and 23 and into lines 61, 62, 63 respectively. These lines transport the clean fluids, for example extract and desorbent if the desired product is in the extract. These lines 10, 50 can be flushed either 10 continuously or sequentially by means of lines 23, 63 and valves 23a, 63a respectively. When flushing is to be continuous, valves which can regulate a constant and substantially even flow rate whatever the introduction position are used. In contrast, when flushing is to be sequential, on-off valves are used. Valves 23a, 63a can place each distributor 3, 5 in communication with a line 250 to either extract or inject a flushing fluid into lines 10, 50. The following can be injected via line 250:
either desorbent, in which case valve 251a is opened and the flow rate is regulated using flow meter 256 and control valve 257 (valves 254a, 255a and 258a are closed);
or extract, in which case valve 255a is opened. Pump 253, flow meter 256 and control valve 257 send a regulated flow of extract to line 250 (valves 251a, 254a and 258a are closed);
or extract which is depleted in desorbent, in which case valve 254a is opened, pump 253, flow meter 256 and control valve 257 send a regulated flow of depleted extract to line 250 (valves 251a, 255a and 258a are closed).
The contents of lines 10, 50 can be extracted via line 250. Valves 255a and 258a are opened (valves 251a, 254a are closed), and flow meter 256 and control valve 257 extract a regulated flow of extract-desorbent mixture and send it to distillation column 203.
Lines 30, 70 lead into lines 41, 42, 43 and lines 81, 82, 83 respectively. These lines transport the dirty fluids, for example the raffinate and feed if the desired product is in the extract. These lines 30, 70 can be flushed either continuously or sequentially by means of lines 43, 83 and valves 43a, 83a. When flushing is to be continuous, valves which can regulate a constant and even flow rate whatever the introduction position are used. In contrast, when flushing is to be sequential, on-off valves are used. Valves 43a, 83a can place each distributor 3, 5 in communication with a line 350 to either extract or inject a flushing fluid into lines 30, 70.
Desorbent can be injected via line 350, in which case valve 353a is opened, valve 354a is closed, and control valve 352 and flow meter 351 regulate the injection flow rate.
A mixture of feed and raffinate can be extracted via line 350 and returned to distillation column 403 (valve 354a open and valve 353a closed) at a flow rate which is regulated by control valve 32 and flow meter 351.
Referring to FIG. 2 alone, the distributor plates communicate externally with four circulation lines:
10, 20, 30, 40 for plate 3;
50, 60, 70, 80 for plate 5.
Lines 24, 64 are connected to lines 20, 60. Lines 20, 60 exclusively transport desorbent from line 100 or desorbent for flushing from line 150 via valves 24a, 64a. They can be flushed either continuously or sequentially by means of lines 24, 64. When flushing is to be continuous, valves which can regulate a constant and substantially even flow rate whatever the introduction position are used. In contrast, when flushing is to be sequential, on-off valves are used.
Valves 24a, 64a can place each distributor 3, 5 in communication with a line 150 to either extract or introduce a flushing fluid into lines 20, 60.
Desorbent can be injected via line 150. Valve 151a is opened and the flow rate is regulated by means of flow meter 152 and control valve 153 (valve 154a is closed). A mixture of desorbent and extract can be extracted via line 150: valve 154a is opened (valve 151a is closed) and the flow rate is regulated by means of flow meter 152 and control valve 153.
Lines 23, 63 are connected to lines 10, 50. Lines 10, 50 exclusively transport extract via valves 22a, 62a (towards line 200) and a flushing stream from or to line 250 via valves 23a, 63a.
They can be flushed either continuously or sequentially. When flushing is to be continuous, valves which can regulate a constant and substantially even flow rate whatever the introduction position are used. In contrast, when flushing is to be sequential, on-off valves are used.
Valves 23a, 63a can place each distributor 3, 5 in communication with line 250 to:
either inject desorbent; in which case valve 251a is opened and the flow rate is regulated using flow meter 256 and control valve 257 (valves 254a, 255a and 258a are closed);
or inject extract; in this case, valve 255a is opened, pump 253, flow meter 256 and control valve 257 send a regulated flow of extract to line 250 (valves 251a, 254a and 258a are closed);
or inject extract which is depleted in desorbent; in which case valve 254a is opened, pump 253, flow meter 256 and control valve 257 send a regulated flow of depleted extract to line 250 (valves 251a, 255a and 258a are closed);
or extract the contents of lines 10, 50, in which case valves 255a and 258a are opened (valves 251a, 254a are closed). Flow meter 256 and control valve 257 extract a regulated flow rate of a mixture of extract and desorbent and send it to distillation column 203.
Lines 44, 84 are connected to lines 40, 80. Lines 40, 80 exclusively transport feed via valves 41a, 81a (from line 300) or desorbent for flushing the line from line 450 via valves 44a, 84a.
They can be flushed either continuously or sequentially by means of lines 44, 84. When flushing is to be continuous, valves which can regulate a constant and substantially even flow rate whatever the introduction position are used. In contrast, when flushing is to be sequential, on-off valves are used.
Valves 44a, 84a can place each distributor 3, 5 in communication with line 450 to:
either inject desorbent, in which case valve 453a is opened, valve 454a is closed and the flow rate is regulated using flow meter 451 and control valve 452;
or extract the contents of lines 40, 80, in which case valve 454a is opened, valve 453a is closed and the flow rate is regulated using flow meter 451 and control valve 452.
Lines 43, 83 are connected to lines 30, 70. Lines 30, 70 exclusively transport raffinate via valves 42a, 82a (to line 400) and a flushing stream to line 350 via valves 43a, 83a.
These lines can be flushed either continuously or sequentially. When flushing is to be continuous, valves which can regulate a constant and substantially even flow rate whatever the introduction position are used. In contrast, when flushing is to be sequential, on-off valves are used.
Valves 43a, 83a can place each distributor 3, 5 in communication with line 350 to:
either inject desorbent, in which case valve 353a is opened, valve 354a is closed, and control valve 352 and flow meter 351 regulate the flow;
or a mixture is extracted from the adsorber via lines 30, 70 and returned (valve 354a open, valve 353a closed) to the raffinate distillation column 403. The flow rate is regulated by flow meter 351 and control valve 352.
The following examples illustrate the invention:
Descriptive Section Which is Common to Examples 1 to 19
A simulated moving bed separation unit constituted by 24 adsorbent beds was disposed in two columns, each with twelve beds. The internal diameter of each bed was 915 mm. The heights of beds n° 1 to 11 and 13 to 23 were all substantially the same while the heights of beds 12 and 24 were reduced: in accordance with French patent FR-A-2 721 529, the beds located near the recycling pumps were shorter to compensate for the effects of the dead volume in each recycling loop.
The average volume of each bed was 0.686 m 3 , to which was added an average of 0.031 m 3 per bed representing the total dead volume (recycle loops and internal volumes of distributors).
A distributor between every two beds separated the beds and was connected to the exterior by two distinct lines. The first of these two lines led into a feed valve, a raffinate valve and a flushing valve for the "dirty" service line. Each on-off flushing valve was followed by a manual valve for regulating the flow rates. The second of these two lines led into a desorbent valve, an extract valve and a flushing valve for the "clean" service line.
The feed circulation line was provided with a pump, a flow rate control valve and a flow meter, and connected to each of the 24 "dirty" service lines of each stage.
The raffinate circulation line was provided with a pressure control valve and a flow meter, and connected to each of the 24 "dirty" service lines of each stage.
The "dirty" flushing circulation line was provided with a flow meter. It could be connected either to the intake of the desorbent pump or to the supply to the raffinate distillation column. Thus it could carry the in or the out flushes.
The desorbent circulation line was provided with a pump, a flow rate control valve and a flow meter, and was connected to each of the 24 "clean" service lines of each stage.
The extract circulation line was provided with a flow rate control valve and a flow meter, and connected to each of the 24 "clean" service lines of each stage.
The "clean" circulation line was provided with a pump, a flow rate control valve and a flow meter. It could be connected either to the intake of the desorbent pump or just downstream of the extract control valve, or finally to the 25 th plate of the extract distillation column (the first forty were in the rectification zone, the last twenty were in the stripping zone). This clean flushing distribution line could thus effect in flushes of either desorbent or extract, or of extract depleted in desorbent.
The adsorbent was an X zeolite with barium as the principal compensating cation. The desorbent was constituted by 97.9% para-diethylbenzene, 1.6% meta-diethylbenzene and 0.5% of about ten different aromatic constituents containing 10 carbon atoms. The feed to be separated was constituted by 3.1% of paraffins and naphthenes, 1.2% of toluene, 11.6% of ethylbenzene, 21.9% of para-xylene, 39.1% of meta-xylene, 21.9% of ortho-xylene and 0.2% of various aromatic constituents containing 9 carbon atoms.
The unit was operated isothermally at 165° C. The pressure at the intake of the two recycling pumps was regulated at 9 bars. The compositions of the streams were obtained by the average of analysis of five series of samples (desorbent, extract, feed, raffinate) extracted every six hours. The flow rates corresponded to an average measurement over 24 hours. The purity was calculated with respect to the composition of the extract, and the yield with respect to the compositions and flow rates of the extract and raffinate.
The material balances showed a difference of at most 0.3% for the major constituents (C 8 aromatics and para-diethylbenzene) and at most 2.6% for the minor constituents (paraffins and naphthenes, toluene, C 9 aromatics, meta-diethylbenzene, other C 10 aromatics).
EXAMPLE 1 (comparative, with no line flushing)
There were 5 beds in zone 1 between desorbent injection and extract extraction, 9 beds in zone 2 between extract extraction and feed injection, 7 beds in zone 3 between feed injection and raffinate extraction, and 3 beds in zone 4 between raffinate extraction and desorbent injection. The following flow rates were used for the temperature and pressure conditions: desorbent 18.3 m 3 /h, extract 6.95 m 3 /h, feed 11.8 m 3 /h; raffinate 23.15 m 3 /h. The permutation period was 56 seconds, and thus the complete cycle lasted 22 minutes 24 seconds.
The composition of the extract was: paraffins and naphthenes 0.009%; toluene 1.121%; ethylbenzene 0.055%; para-xylene 35.324%; meta-xylene 0.095%; ortho-xylene 0.048%; C 9 aromatics 0.017%; meta-diethylbenzene 1.021%; para-diethylbenzene 62.012%, C 10 aromatics 0.298%.
The purity was calculated with respect to the paraffins and naphthenes, ethylbenzene, meta-xylene, ortho-xylene and the C 8 aromatics. Toluene was not included as it was removed in a further distillation column. The purity was 99.37%. The composition of the raffinate was: paraffins and naphthenes 1.58%; toluene 0.271%; ethylbenzene 5.887%; para-xylene 0.555%; meta-xylene 19.903%; ortho-xylene 11.65%; C 9 aromatics 0.097%; meta-diethylbenzene 0.952%; para-diethylbenzene 58.82%, C 10 aromatics 0.30%. The yield was thus 95%.
EXAMPLE 2: (flushing the clean line with desorbent, in accordance with the invention)
Example 1 was repeated, connecting the "clean" flushing circuit to the desorbent pump discharge. The flushing desorbent flow rate was 0.96 m 3 /h.
The temperature and pressure were identical to Example 1. As above, there were 5 beds in zone 1, 7 beds in zone 3 and 3 beds in zone 4. However, there was one bed between the extract extraction and the flush injection (zone 5) and there were 8 beds between the flush injection and the feed injection (zone 2).
The flow rates of desorbent, feed and raffinate were strictly identical to those of Example 1. The flow rates in zone 1, zone 2, zone 3 and zone 4 were strictly identical to those of Example 1.
However, the extract flow rate was held at 7.91 m 3 /h and the flow rate in the bed located between the extract extraction and the flush injection (zone 5) was reduced by 0.96 m 3 /h relative to the above case; this meant that the average recycle flow rate remained 56.06 m 3 /h.
Under these conditions, the para-xylene content in the extract was no more than 31.072%. The amounts of impurities were: paraffins and naphthenes 0.002%; ethylbenzene 0.044%; meta-xylene 0.051%, ortho-xylene 0.026%; C 9 aromatics 0.008%. The purity was thus 99.58%, and the yield was practically unchanged: 95.02%.
EXAMPLE 3 (flushing the "clean" line with desorbent)
The conditions of Example 2 were repeated, with the exception that the flow rate of the flushing desorbent was reduced from 0.96 m 3 /h to 0.48 m 3 /h.
The extract flow rate was then 7.43 m 3 /h, and the average recycle flow rate as 56.08 m 3 /h.
The composition of the extract was: paraffins and naphthenes 0.002%; ethylbenzene 0.045%; para-xylene 33.044%; meta-xylene 0.0052%, ortho-xylene 0.026%; C 9 aromatics 0.008%. The purity was thus 99.60%, and the yield remained 95%.
EXAMPLE 4 (flushing the "clean" line with desorbent)
The conditions of Example 2 were repeated, with the exception that the flow rate of the flushing desorbent was reduced to 0.24 m 3 /h. The extract flow rate was then 7.19 m 3 /h, and the average recycle flow rate was 56.09 m 3 /h. The purity was 99.59%, and the yield was 94.99%.
EXAMPLE 5 (flushing the "clean" line with desorbent)
Example 3 was repeated, changing only the distribution of beds between zones 5 and 2. There were 2 beds between the extract extraction and the flushing injection. There were 7 beds between the flushing injection and the feed injection. The average recycle flow rate changed as there was one extra bed in zone 5 and one less bed in zone 2: instead of 56.08 m 3 /h (Example 3), it reduced to 56.06 m 3 /h. The purity was 99.65%, and the yield was 94.99%.
EXAMPLES 6 TO 8 (flushing the "clean" line with extract)
The clean flushing circuit was connected downstream of the extract control valve. The flushing extract flow rate was 0.48 m 3 /h.
The flow rates in zones 1, 5, 2, 3, 4 and the desorbent, flushing, feed, extract and raffinate flow rates were identical to those of Example 3. The temperature and pressure conditions were identical to those of Examples 1 to 5. The number of beds in zones 5 and 2 were varied as shown in Table I
TABLE I______________________________________ Average recycle Beds in Beds in flow rate Purity YieldExample zone 5 zone 2 m.sup.3 /h % %______________________________________6 1 8 56.08 99.65 94.827 2 7 56.06 99.70 94.808 4 5 56.02 99.75 94.77______________________________________
EXAMPLES 9 AND 10 (flushing of "clean" line with extract depleted in desorbent)
The "clean" flushing circuit was connected to the extraction plate of the extraction column (25 th plate in the rectification zone). The distillation column was regulated so that the concentration of para-xylene at this plate was about 65%.
This figure corresponded to the maximum concentration of para-xylene in the adsorber. This maximum was localised in zone 2.
The flow rates in zones 1, 5, 2, 3, 4 and the desorbent, flushing, feed, extract and raffinate flow rates, also the temperature and pressure conditions were identical to those of Examples 6 to 8. The number of beds in zones 5 and 2 were varied as shown in Table II
TABLE II______________________________________ Average recycle Beds in Beds in flow rate Purity YieldExample zone 5 zone 2 m.sup.3 /h % %______________________________________ 9 2 7 56.06 99.73 94.8110 4 5 56.02 99.77 94.79______________________________________
EXAMPLES 11 AND 12 (flushing with extract in two different positions)
The clean flushing circuit was connected downstream of the extract control valve. The flushing extract flow rate was 0.48 m 3 /h.
The valves connected to the clean flushing circuit were activated twice during the 56 second period.
During the first part of the period, there were 7 beds between the extract extraction and the flushing injection and 2 beds between the flushing injection and the feed injection. During the second part of the period, there were 2 beds between the extract extraction and the flushing injection and 7 beds between the flushing injection and the feed injection.
The flow rates in zones 1, 3, 4, the flow rates of desorbent, flushing, extract and raffinate, also the temperature and pressure conditions, were identical to those of Examples 6 to 8.
During the entire period, zones 2 and 5 had no more than 2 beds each and their flow rates were identical to those in Examples 6 to 8. There were alternately 5 beds in zone 5 during the first part of the period then in zone 2 during the second part of the period. To account for this particular feature, when the recycle pump was connected to these five beds, the set recycle flow rate value was the arithmetic mean of the flow rates in zone 5 and in zone 2 (Table III). A sixth zone thus existed, exactly as if two clean flushing streams were being permanently injected into two different areas of the adsorber.
TABLE III______________________________________ Average Second recycle First part part flow rate Purity YieldExample s s m.sup.3 /h % %______________________________________11 16 40 56.03 99.72 94.7512 28 28 56.02 99.79 94.70______________________________________
These Examples 11 and 12 should be compared with Example 7.
EXAMPLE 13 (flushing with depleted extract at two different positions)
The clean flushing circuit was connected to the extraction plate of the extraction column. The procedure was exactly as in Example 12, with the same conditions of flow rates, the same arrangement of zones 2 and 5, and the same division of time between the two parts of the 56 second period.
The purity was 99.82%, and the yield was 94.68% (compare with Examples 10 and 12).
EXAMPLE 14 (for comparison with Example 13)
The temperature was raised to 175° C. and other conditions were used: the mass flow rates were the same as in Example 13, the volume flow rates were all increased by 0.9% (in inverse proportion to the density of the feed at 165° C. and at 175° C.). The permutation period was reduced from 56 seconds to 55.6 seconds. The first and second parts of the period were each 27.8 seconds.
The purity was 99.86%, and the yield was 94.76%.
EXAMPLE 15 (sequential flushing of the clean line and continuous out flush of the dirty line)
Compared with Example n° 13, the desorbent flow rate was increased by 0.24 m 3 /h (i.e., from 18.3 m 3 /h to 18.54 m 3 /h). The dirty flushing line was connected to the supply to the raffinate distillation column. All of the dirty flush on-off valves were open and the flow rates were regulated for each stage so that a continuous flow rate of 0.01 m 3 /h was extracted from each distributor. The total of the dirty flushes leaving the unit was in total 0.24 m 3 /h. This stream was sent to the supply to the raffinate distillation column.
The purity was 99.83% and the yield was 94.27%.
EXAMPLE 16 (sequential flushing of the clean line and the dirty line)
Example 13 was repeated, with two flushing valves which were operated sequentially. There was one bed between the desorbent injection and the dirty flush extraction, and four beds between the dirty flush extraction and the extract extraction. The flow rate of the desorbent was 18.54 m 3 /h and the dirty flush flow rate was 0.24 m 3 /h. One period per cycle, when the recycle pump was connected to the bed in zone 7 (between the desorbent injection and the dirty flush extraction), the rate of the pump was increased by 0.24 m 3 /h with respect to the rate in zone 1. The purity was 99.84% and the yield was 94.65%.
EXAMPLE 17 (sequential in flush between the clean and dirty lines)
The conditions of Example 10 were repeated, with the dirty flushing line being connected to the discharge of the desorbent pump. The dirty flushing on-off valves were operated sequentially. The dirty flush was injected at the same place as the clean flush: four beds after the extract extraction.
The flow rate in zone 5 dropped by 0.24 m 3 /h, the extract flow rate increased by 0.24 m 3 /h (from 7.43 m 3 /h to 7.67 m 3 /h). The average recycle flow rate reduced from 56.02 m 3 /h to 55.98 m 3 /h. The purity was 99.68% and the yield was 95.49%.
EXAMPLE 18 (flushing in two different positions of the clean line and sequential in flush of the dirty line)
The conditions of Examples 12 and 17 were repeated. The dirty flush was injected 7 beds after extract extraction and two beds before the feed injection. A flow rate of 0.24 m 3 /h of desorbent was used. The average recycle flow rate was 55.95 m 3 /h. The purity was 99.78% and the yield was 95.34%.
EXAMPLE 19 (flushing at two different positions of the "clean" line using extract depleted in desorbent and sequential flush out of the "clean" line)
The conditions of Example 14 were repeated, adding the sequential flush out described in Example 16. The purity was 99.89% and the yield was 94.67%.
The following section of the description is common to Examples 20 to 24. In the unit described above, the distributors separating the beds were replaced by distributors connected to the exterior by four distinct lines. The first of these lines led into a feed valve and a flush valve. The second of these lines led into a raffinate valve and a flush valve. The third line led into a desorbent valve and a flush valve. The fourth line led into an extract valve and a flush valve.
The composition of the feed and desorbent, also the nature of the molecular sieve, were identical to those of Examples 1 to 19.
EXAMPLE 20 (comparative)
The operating conditions of Example 1 were strictly repeated. The purity obtained was 99.19% and the yield was 96.21%.
EXAMPLE 21 (sequential flushing in two different positions of the extract line only)
The operating conditions of Example 14 were strictly repeated. The purity obtained was 99.69% and the yield was 95.95%.
EXAMPLE 22 (sequential flushing in two different positions of the extract line and sequential in flush of the desorbent line)
The conditions of Example 21 were repeated. In addition, a flushing stream constituted by 0.24 m 3 /h of desorbent was injected into the flushing valve connected to the desorbent line, issuing 4 beds downstream of the extract extraction. The purity obtained was 99.88%, and the yield was 95.55%.
EXAMPLE 23 (sequential flushing in two different positions of the extract line, sequential in flush of the desorbent line, sequential out flush of the feed line)
The conditions of Example 22 were repeated, increasing the desorbent flow rate by 0.24 m 3 /h and extracting a stream of 0.24 m 3 /h via the flushing valve connected to the feed line one bed downstream of the desorbent injection.
The out flush stream was sent to the feed addition line. The purity obtained was 99.90%, and the yield was 94.97%.
EXAMPLE 24 (sequential flushing in two different positions of the extract line, sequential in flush of the desorbent line, sequential out flush of the feed line, sequential out flush of the raffinate line)
The conditions of Example 23 were repeated, increasing the desorbent flow rate by 0.24 m 3 /h and extracting a stream of 0.24 m 3 /h via the flushing valve connected to the raffinate line one bed downstream of the desorbent injection. The out flush stream was sent to the raffinate distillation. The purity obtained was 99.91%, and the yield was 94.62%.
Examples 2 to 19 and 21 to 24 show that it is essential to rinse the clean line or lines to obtain large gains in purity and to separate the raffinate line and feed line to obtain a large gain in yield. Flushing the dirty lines only results in small gains in purity at the expense of a large drop in yield. | An apparatus and process are described for simulated moving bed separation in which line containing fluid containing the desired product is flushed at least once by a secondary fluid entering each distribution plate or by a fluid leaving each of said plates during at least a portion of a period of time between two successive permutations of the principal supply lines and the principal extraction lines, or during the entirety of said periods, the secondary fluid being selected from the group formed by the solvent, the fluid containing the desired product and the fluid containing the desired product freed of at least a portion of the solvent. | 1 |
BACKGROUND OF INVENTION
The invention relates to the field of privacy keypads, and more particularly concerns concealment of operation of a keypad in an escutcheon for a door lock and concealment of a joint in an escutcheon.
Keypads are often used to enter private or secure information. For example, such information includes codes for operating door locks, banking account numbers and passwords, and long distance calling card numbers. In order to prevent people positioned behind or adjacent to a user from viewing the keypad, the user must position his or her body or hand over the keypad. In some instances doing so may be difficult or socially awkward, and in general a user may neglect to take such a precaution.
A keypad is disposed on an escutcheon for an electronic door lock for operation of the lock. Upon entry of a predetermined code, the keypad sends an electrical signal to the lock that unlocks the lock. Shields may be used to obstruct the view of the keypad. A conventional shield for a keypad may obstruct the view of the keypad with a front element that covers the keypad and side elements adjacent to the keypad. The front element may be stationary, leaving enough room for a user's hand to operate the keys, or may move, for example, by having a hinge that allows that element to rotate away from the keypad enough to allow a user's hand to operate the keys. The front element may be opaque, which impedes the view by the user, or it may be polarized, preventing view through the element at an angle but allowing direct viewing. However, the front element can interfere with free operation of the keypad. Further, the front element is a part commonly separate from the device that includes the keypad, and is subject to breakage and vandalism.
Side elements are generally mounted vertically adjacent to the sides of the keypad and may also be opaque or polarized. Unfortunately, like the front element, the side elements are parts that are commonly separate from the device that includes the keypad, and accordingly are also subject to damage.
Accordingly, there exists a need for a view-shielding means that is integral with a door escutcheon that includes a keypad and reduces opportunity for damage.
SUMMARY OF INVENTION
In accordance with an embodiment of the present invention, a privacy keypad includes a faceplate, a keypad, and at least one protrusion. The keypad is disposed on the faceplate. The protrusion is integral with the faceplate and extends upwardly from the surface of the faceplate laterally adjacent to the keypad. The protrusion obstructs at least partially a line of sight to the keypad by being of a sufficient height and length along the central longitudinal axis of the keypad to do so. The protrusion may be of unitary construction with the faceplate. A line from the center point of the keypad normal to the central longitudinal axis of the keypad to the top of a protrusion may form an angle of at least about 10 degrees with a plane tangential to the surface of the faceplate along the central longitudinal axis of the keypad.
In another embodiment according to the present invention, a privacy keypad includes two parallel protrusions laterally adjacent to and on opposite sides of the keypad. Each protrusion at least partially obstructs a line of sight to the keypad. The protrusions may define a longitudinal channel in the faceplate for receiving the keypad.
In another embodiment according to the present invention, a privacy keypad includes a faceplate, a keypad disposed on the faceplate, and two parallel protrusions. The two parallel protrusions extend upwardly from the surface of the faceplate laterally adjacent to and on opposite sides of the keypad to define a longitudinal channel in the faceplate for receiving the keypad. The protrusions are integral and of unitary construction with the faceplate, and each protrusion is of a sufficient height and length along the longitudinal axis of the keypad to obstruct at least partially a line of sight to the keypad.
In another embodiment according to present invention, an escutcheon for a door lock includes a housing, a keypad, and at least one protrusion. The keypad is disposed on the housing for unlocking the door lock. The protrusion is integral with the housing and extends upwardly from the surface of the housing laterally adjacent to the keypad. The protrusion obstructs at least partially a line of sight to the keypad by being of a sufficient height and length along the central longitudinal axis of the keypad to do so. The protrusion may be of unitary construction with the housing. A line from the center point of the keypad normal to the central longitudinal axis of the keypad to the top of a protrusion may form an angle of at least about 10 degrees with a plane tangential to the surface of the housing along the central longitudinal axis of the keypad.
In another embodiment according to the present invention, an escutcheon for a door lock includes two parallel protrusions laterally adjacent to and on opposite sides of the keypad. Each protrusion at least partially obstructs a line of sight to the keypad. The protrusions may define a longitudinal channel in the housing for receiving the keypad.
In another embodiment according to the present invention, an escutcheon for a door lock includes a housing and a keypad disposed on the housing for unlocking the door lock. Two parallel protrusions extend upwardly from the surface of the housing laterally adjacent to and on opposite sides of the keypad to define a longitudinal channel in the housing for receiving the keypad. The protrusions are integral and of unitary construction with the housing, and each protrusion is of a sufficient height and length along the longitudinal axis of the keypad to obstruct at least partially a line of sight to the keypad.
In another embodiment according to the present invention, a lockset for a door includes a housing, a lock, and a keypad operatively connected to the lock for unlocking the lock by electrical signal. The lock is disposed in and the keypad is disposed on the housing. Two parallel protrusions extend upwardly from the surface of the housing laterally adjacent to and on opposite sides of the keypad to define a longitudinal channel in the housing for receiving the keypad. The protrusions are integral with the housing, and each protrusion is of a sufficient height and length along the longitudinal axis of the keypad to obstruct at least partially a line of sight to the keypad. The protrusions may be of unitary construction with the housing.
In another embodiment according to the present invention, an escutcheon for a door lock includes a lower cover having an opening through which a door latch operator passes. The lower cover has a surface projecting a first distance away from the surface of the door and has a top edge. An upper cover having a bottom edge has a surface that projects away from the surface of the door a second distance that is greater than the first distance. The upper cover is mounted to the surface of the door above the lower cover such that the bottom edge of the upper cover and top edge of the lower cover are in close and complementary registration. The top edge of the lower cover and the bottom edge of the upper cover may be arcuate. The arcuate top edge of the lower cover may be convex while the arcuate bottom edge of the upper cover is concave. The arcuate top edge of the lower cover may be concave while the arcuate bottom edge of the upper cover is convex.
In another embodiment according to the present invention, an escutcheon system for a lock on a door includes a lower cover through which a latch operator passes, adapted to be mounted to the surface of the door and having a top edge. A first upper cover has a bottom edge. The first upper cover is adapted to be mounted to the surface of the door above the lower cover such that the bottom edge of the first upper cover and the top edge of the lower cover are in close and complementary registration. A second upper cover differing from the first upper cover in size, features, or a combination thereof, has a bottom edge. Like the first upper cover, the second upper cover is adapted to be mounted to the surface of the door above the lower cover such that the bottom edge of the second upper cover and top edge of the lower cover are in close and complementary registration. The top edge of the lower cover, bottom edge of the first top cover, and bottom edge of the second lower cover may be arcuate.
In another embodiment according to the present invention, an escutcheon system for a lock on a door includes an upper cover adapted to be mounted to the surface of the door and having a bottom edge. A first lower cover through which a latch operator passes has a top edge. The first lower cover is adapted to be mounted to the surface of the door below the upper cover such that the top edge of the first lower cover and bottom edge of the upper cover are in close and complementary registration. A second lower cover through which a latch operator passes differs from the first upper cover in size, features, or a combination thereof. The second lower cover has a top edge. Like the first lower cover, the second lower cover is adapted to be mounted to the surface of the door below the upper cover such that the top edge of the second lower cover and bottom edge of the upper cover are in close and complementary registration. The bottom edge of the upper cover, top edge of the first lower cover, and top edge of the second lower cover may arcuate.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is an exploded perspective view of an embodiment of a lockset according to the present invention.
FIG. 2 is a front elevation view of an outer escutcheon and door handle of the lockset of FIG. 1 .
FIG. 3 is a side elevation view of the outer escutcheon and door handle of FIG. 2 .
FIG. 4 is a section view of the escutcheon and door handle taken along the line 4 — 4 of FIG. 2 .
FIG. 5 is a section view of the escutcheon and door handle taken along the line 5 — 5 of FIG. 2 .
FIG. 6 is a perspective view of the escutcheon and door handle of FIG. 2 .
FIG. 7 is a front elevation view of an inner escutcheon and door handle of the lockset of FIG. 1 .
FIG. 8 is a front elevation view of another embodiment of an outer escutcheon and door handle according to the present invention.
DETAILED DESCRIPTION
In the Figures herein, unique features receive unique reference numerals, while features that are the same in more than one drawing receive the same reference numerals throughout. Where a feature is modified between figures or is modified only by a change in location, a letter may be added or changed after the feature reference numeral to distinguish that feature from a similar feature in a previous figure or the same feature in an alternate location. Further, certain terms of orientation may be used, such as “upper”, “lower”, “top”, “bottom”, “left”, “right”, “inside”, “outside”, “inner”, and “outer”. These terms are generally for convenience of reference, and should be so understood unless a particular embodiment requires otherwise.
The scope of the invention is not intended to be limited by materials listed herein, but may be carried out using any materials that allow the construction and operation of the present invention. Materials and dimensions depend on the particular application. In general the materials of the components may be metal, and selectively may be plastic, as known by one of ordinary skill in the art.
Referring now to the drawings, an embodiment of a lockset 20 according to the present invention is shown in FIG. 1 . The lockset 20 includes an inner rose assembly 22 mounted through an opening 24 in a door 26 to an outer rose assembly 28 as is conventional. Fasteners and electrical wiring are omitted from FIG. 1 for clarity.
A lower cover 32 fits over the outer rose assembly 28 and against the outside surface 30 of the door 26 . An opening 36 in the lower cover 32 allows connection of an outside lever handle 34 to an operating spindle associated with the outer rose assembly 28 . As best seen in FIG. 4 , the diameter of the hub of the outside lever handle 34 is slightly larger than the opening 36 in the lower cover 32 so that the lower cover 32 is held snugly against the outside surface 30 of the door 26 . Referring again to FIG. 1 , a lower cover 32 a is similarly mounted against the inside surface 42 of the door 26 . Specifically, a hub of an inside lever handle 34 a having a diameter slightly larger than an opening 36 a in the lower cover 32 a is fixed for rotation with an operating spindle associated with the inner rose assembly 22 . It is understood that rotation of either handle 34 , 34 a functions to retract a latch (not shown) which extends through an opening 38 in the edge of the door 26 .
A battery holder 50 is fastened to the inside surface 42 of the door 26 above the lower cover 32 a for accommodating batteries (not shown) which provide an electrical power source for operating the lockset 20 . An upper cover 52 is fastened to the battery holder 50 and against the inside surface 42 of the door 26 with a fastener (not shown) through an opening 53 in the upper cover 52 . Similarly, an upper cover 56 is mounted against the outside surface 30 of the door 26 above the lower cover 32 . The upper cover 56 includes a transverse threaded socket 78 ( FIGS. 3 and 4 ) that is received in an opening 57 in the door 26 . A fastener (not shown) extends through an opening 58 in the battery holder 50 for securing the outer upper cover 56 to the door 26 . The upper and lower covers 52 , 32 a , 56 , 32 on each side of the door 26 form inner and outer escutcheon housings, respectively. A keypad 60 is provided on the outer upper cover 56 .
The outer escutcheon 62 is shown in FIG. 2 . The bottom edge 74 of the upper cover 56 is concave and mates with the top edge 76 of the lower cover 32 , which is convex. A channel 64 having a central longitudinal axis A—A is formed in the surface of the upper cover 56 and is defined by upstanding sidewalls 70 , 72 . In this embodiment of the present invention, the sidewalls 70 , 72 are of unitary construction with the upper cover 56 , in that the sidewalls 70 , 72 and upper cover 56 are all formed from one piece of material. This integral and unitary construction reduces or eliminates the opportunity for damage to the sidewalls 70 , 72 .
The keypad 60 is mounted in the channel 64 . In this embodiment the central longitudinal axis A—A of the channel 64 is also the central longitudinal axis of the keypad 60 . The keypad 60 may comprise a touch sensitive device or buttons, as shown, that extend outwardly from the surface of the channel 64 . The channel 64 that is shown has a substantially planar surface, but other shapes such as a curved surface or the like may be used.
As best seen in FIG. 3 , when the outer escutcheon 62 is viewed from a position adjacent to the door 26 , the keypad 60 is obstructed by the sidewalls 70 , 72 that shield the keypad 60 . FIGS. 4 and 5 are section views of the outer escutcheon 62 showing that the sidewalls 70 , 72 protrude from the surface of the channel 64 and beyond the keys to shield the keypad 60 from the view of an observer.
To shield the keypad from the view of an observer the sidewalls 70 , 72 must be a certain height. The height of a sidewall 70 , 72 may be determined by considering that the sidewalls 70 , 72 protrude to a height from the surface of the channel 64 that corresponds to a predetermined angle from the center of the keypad 60 , in conjunction with the lateral spacing of the sidewalls 70 , 72 from the keypad 60 . Referring to FIGS. 2 , 4 , and 5 , this necessary height is best shown by a line from the center point 73 of the keypad 60 normal to the central longitudinal axis A—A to the top 75 , 77 of the sidewall 70 , 72 that forms an angle □ of at least about 10 degrees with a plane 79 tangential to the surface of the channel 64 along the central longitudinal axis A—A. In the embodiment shown, the tops 75 , 77 of the sidewalls 70 , 72 are closely adjacent to the keypad 60 and are sufficiently close to obstruct at least partially the view of the keypad 60 by an observer. The sidewalls 70 , 72 may taper longitudinally as shown, but need not do so and must remain a height that continues to obstruct at least partially the view of the keypad 60 by an observer.
FIG. 6 is a perspective view of the outer escutcheon 62 as viewed by a typical observer. This figure shows that as the outer escutcheon 62 is viewed from this angle, the line of sight to the keypad 60 is obstructed. The keypad 60 becomes less visible as the observer moves closer to the door 26 . Also, from the vantage point shown in FIG. 6 , the line of sight to the joint between the upper cover 56 and lower cover 32 is obstructed. Even where the joint may be in view, the joint can appear to be a bend in the escutcheon 62 rather than a joint between two parts.
The inside escutcheon 80 , comprising an upper cover 52 that covers the battery holder 50 and the lower cover 32 a , is shown in FIG. 7 . The bottom edge 81 of the upper cover 52 is concave and mates with the upper edge 82 of the lower cover 32 a , which is convex. Conversely, the bottom edge of the upper cover 52 could be convex and the top edge of the lower cover 32 a could be concave. In addition, the bottom edges of the upper covers 52 , 56 and the top edges of the lower covers 32 , 32 a could be straight. A feature of the present invention is the ability to interchange upper covers and lower covers of different shape as long as they have complimentary edges that mate to form a continuous joint. For example, the outer upper cover 56 and inner upper cover 52 are interchangeable because they fit with complementary lower covers.
Another embodiment of an outer escutcheon is shown in FIG. 8 and generally designated at 84 . This embodiment includes an upper cover 92 and a lower cover 94 . The upper cover 92 is generally circular in cross-section. The lower cover 94 is elongated relative to that of the prior embodiment of the outer lower cover 32 . The bottom edge 96 of the upper cover 92 is convex, and mates with the top edge 98 of the lower cover 94 , which is concave. Similarly to the previous embodiments, the upper cover 92 and lower cover 94 may be interchanged with other parts having like joint edges.
Similar to the previously described embodiment of the outer escutcheon 62 , a keypad 60 a is disposed in a longitudinal channel 64 a defined by upstanding sidewalls 86 , 88 on the upper cover 92 . The sidewalls 86 , 88 are similar to those in the previous embodiment 62 in that the sidewalls 86 , 88 are integral with and are a part of the upper cover 92 , but differ in that they are not of unitary construction. One sidewall 88 is made of rubber and may be bonded or otherwise attached to the remainder of the upper cover 92 . A light source 90 , such as a light emitting diode, is provided in one of the sidewalls 86 for illuminating the keypad 60 a . Optionally light sources may be located on both sidewalls 86 , 88 .
Specific embodiments of an invention are described herein. One of ordinary skill in the lock and security hardware arts will recognize that the invention has other applications in other environments. In fact, many embodiments and implementations are possible. For example, the escutcheon of the present invention may be made in different shapes and sizes. The mating edges of upper and lower covers may be straight or arcuate, so long as they are in close and complimentary registration. The sidewalls could be applied as shields anywhere keypad security is needed. In addition, the recitation “means for” is intended to evoke a means-plus-function reading of an element in a claim, whereas, any elements that do not specifically use the recitation “means for”, are not intended to be read as means-plus-function elements, even if they otherwise include the word “means”. The following claims are in no way intended to limit the scope of the invention to the specific embodiments described. | A privacy keypad providing privacy for keypad character entry and concealment of a joint in an escutcheon. A privacy keypad may include a faceplate, a keypad disposed on the faceplate, and at least one protrusion integral with the faceplate. An escutcheon for a door lock may include a housing, a keypad disposed on the housing for unlocking the door lock, and at least one protrusion integral with the housing. The protrusion may obstruct at least partially a line of sight to the keypad. An escutcheon may include top and bottom covers with the top cover projecting outward from the surface of a door more than the lower cover, resulting in an at least partially hidden joint between covers. Top and bottom covers may be interchangeable with covers having similar edges. | 4 |
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/676,543 filed Apr. 28, 2005, incorporated by reference herein.
STATEMENT REGARDING FEDERAL RIGHTS
[0002] This invention was made with government support under Contract No. W-7405-ENG-36 awarded by the U.S. Department of Energy. The government has certain rights in the invention.
FIELD OF THE INVENTION
[0003] The present invention relates generally to electrochromic materials and more particularly to an electrochromic polyamide material.
BACKGROUND OF THE INVENTION
[0004] Polyaniline (PANI) is an organic conducting polymer that has shown promise for commercial applications due to its low cost, fast switching in redox states, and environmental stability. Some of the potential applications for PANI include rechargeable batteries [1], electrochromic displays [2], chemical and electromechanical actuators [3], anti-corrosion coatings [4], and electromagnetic interference shielding [5]. PANI, however, is generally a difficult material to process because of its limited solubility [6]. For these reasons, it has become important to develop better methods for processing PANI, to synthesize derivatives of PANI that are easier to process, and to invent other conducting polymers that are easier to process than PANI.
[0005] One of the better methods for processing PANI involves doping PANI with an organic acid. Doping PANI with an organic acid having a bulky alkyl group (camphorsulfonic acid (CSA), dodecylbenzenesulfonic acid (DBSA), or acrylimido-2-methyl-1-propanesulfonic acid (AMPS), for example) improves the solubility in organic solvents such as DMF or DMSO [7]. Soluble derivatives of PANI have been prepared from alkyl-substituted and alkoxy-substituted monomers [8].
[0006] One approach for preparing PANI involves using highly concentrated solutions of emeraldine base (EB) that include a small amount of a gel inhibitor. The gel inhibitor is believed to disrupt interchain H-bonding interactions. Highly concentrated solutions (greater than about 20 weight percent of emeraldine base) have been prepared using this approach [9].
[0007] Another processing method involves incorporating aniline oligomer segments into the polymer backbone. Using this approach, the properties of the polymer may be altered by adjusting the chain length of the oligomer segments [10]. Some materials prepared this way have better physical properties than those for high molecular weight conducting polymers [11].
[0008] There remains a need for conducting polymers that may be processed more easily than PANI.
[0009] Accordingly, an object of the present invention is to provide a conducting polymer that may be processed more easily than PANI.
[0010] Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
SUMMARY OF THE INVENTION
[0011] In accordance with the purposes of the present invention, as embodied and broadly described herein, the present invention includes a polymeric reaction product of a compound of the formula
with a compound of formula X(O═)C—R′—C(═O)X;
wherein n is an integer greater than 2; wherein R is independently selected from hydrogen, alkyl having 1-12 carbon atoms, aryl, alkyl-substituted aryl, alkoxy having 1-4 carbon atoms, fluoroalkyl having 1-12 carbon atoms, fluoride, chloride, bromide, and iodide; wherein Z is independently selected from hydrogen and —(C═O)OR″ wherein R″ is alkyl having 1-12 carbon atoms; wherein R′ is selected from alkyl having 1-12 carbon atoms, aryl, alkyl-substituted aryl, fluoroalkyl, and fluoroaryl; and wherein X is selected from the group consisting of F, Cl, Br, I, and OH.
[0012] The invention also includes a method for preparing a thin film. The method involves dissolving the polymeric reaction product of a first compound and a second compound in a solvent to produce a solution, then casting a film of the solution on a surface, and evaporating the solvent. The first compound has the formula
wherein n is an integer greater than 2; wherein R is independently selected from hydrogen, alkyl having 1-12 carbon atoms, aryl, alkyl-substituted aryl, alkoxy having 1-4 carbon atoms, fluoroalkyl having 1-12 carbon atoms, fluoride, chloride, bromide, and iodide; and wherein Z is independently selected from hydrogen and —(C═O)OR″ wherein R″ is alkyl having 1-12 carbon atoms. The second compound has the formula
X(O═)C—R′—C(═O)X
wherein R′ is selected from alkyl having 1-12 carbon atoms, aryl, alkyl-substituted aryl, fluoroalkyl, and fluoroaryl; and wherein X is selected from the group consisting of F, Cl, Br, I, and OH.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the embodiment(s) of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:
[0014] FIG. 1 shows cyclic voltammagrams of copolymers I, II, III, IV and polyaniline. The voltammagrams were obtained in an aqueous 1.0 M HCl solution using Ag/Ag + as reference electrode with a scanning rate of 50 mV/sec.
[0015] FIG. 2 shows a representation of the polymer backbone for copolymer II of this invention as it undergoes oxidation and reduction.
[0016] FIG. 3 shows Fourier transform infrared (FTIR) spectra of copolymer II in a 1.0 M solution of hydrochloric acid at different potentials (−0.20 V, 0.45 V, 0.75 V, and 1.00 V) followed by a dedoping treatment in an aqueous solution of 0.1 molar (M) ammonium hydroxide.
[0017] FIG. 4 shows UV-VIS spectra of the copolymer II thin film oxidized at different potentials (−0.20 V, 0.45 V, 0.75 V and 1.00 V), followed by the dedoping treatment in an ammonium hydroxide aqueous solution
[0018] FIG. 5 shows UV-VIS spectra of a thin film of copolymer II on an ITO-glass electrode at different oxidation potentials in an aqueous 1.0 M HCl solution; and
[0019] FIG. 6 shows a plot of the transmittance of a thin film of copolymer II as a square wave potential (−0.2 V and 1.0 V) at applied frequencies of 1 Hz, 0.1 Hz, 0.5 Hz, and 0.05 Hz.
DETAILED DESCRIPTION
[0020] Briefly, the present invention is concerned with soluble, electrochromic, copolymers that are processed more easily than PANI. These copolymers are polyamide copolymers, and may be synthesized by reacting oligoaniline monomers with diacyl chloride compounds. An exemplary oligoaniline monomer includes non-conjugated aromatic and aliphatic groups, and amine-protecting groups (tert-butoxy-carbonyl (BOC), for example). It is believed that these groups play a role in improving the solubility of the copolymers.
[0021] An advantage of this invention is related to the solubility of the copolymers as compared to PANI and PANI derivatives. Copolymers of this invention are soluble in volatile solvents such as dichloromethane, chloroform, and acetone, while PANI derivatives have limited solubility in less volatile solvents such as NMP and DMF.
[0022] Another advantage of this invention is concerned with the preparation of thin films of the copolymers as compared to PANI and PANI derivatives. Thin films of the copolymer cast from solution are easily prepared because the solvents are easily removed by evaporation at relatively low temperatures. By contrast, thin films of PANI derivatives cast from solution are not as easily prepared because the solvents (NMP and DMF, for example) are higher boiling and require higher temperatures for their removal. In addition, thin-film quality often suffers from the limited solubility of PANI EB (polyaniline emeraldine base) in these higher boiling solvents.
[0023] The as-cast films of copolymers of this invention are not electrochromic. However, they become electrochromic upon treatment with acid or by heating them under an argon atmosphere.
[0024] Importantly, the electrochromic properties of the invention copolymers were found to be superior to those of PANI.
[0025] In particular, the invention includes a polymeric reaction product of a compound of the formula
with a compound of formula X(O═)C—R′—C(═O)X; wherein n is an integer greater than 2; wherein R is independently selected from hydrogen, alkyl having 1-12 carbon atoms, aryl, alkyl-substituted aryl, alkoxy having 1-4 carbon atoms, fluoroalkyl having 1-12 carbon atoms, fluoride, chloride, bromide, and iodide; wherein Z is independently selected from hydrogen and —(C═O)OR″ wherein R″ is alkyl having 1-12 carbon atoms; wherein R′ is selected from alkyl having 1-12 carbon atoms, aryl, alkyl-substituted aryl, fluoroalkyl, and fluoroaryl; and wherein X is selected from the group consisting of F, Cl, Br, I, and OH.
[0026] The invention also includes a method for preparing a thin film. The method involves dissolving the polymeric reaction product of a first compound and a second compound in a solvent to produce a solution, then casting a film of the solution on a surface, and evaporating the solvent. The first compound has the formula
wherein n is an integer greater than 2; wherein R is independently selected from hydrogen, alkyl having 1-12 carbon atoms, aryl, alkyl-substituted aryl, alkoxy having 1-4 carbon atoms, fluoroalkyl having 1-12 carbon atoms, fluoride, chloride, bromide, and iodide; and wherein Z is independently selected from hydrogen and —(C═O)OR″ wherein R″ is alkyl having 1-12 carbon atoms. The second compound is a diacyl halide compound having the formula
X(O═)C—R′—C(═O)X
wherein R′ is selected from alkyl having 1-12 carbon atoms, aryl, alkyl-substituted aryl, fluoroalkyl, and fluoroaryl; and wherein X is selected from the group consisting of F, Cl, Br, I, and OH. When Z is the carbonyl alkoxy-protecting group, the invention also includes exposing the film to acid, which exchanges the carbonyl alkoxy group for hydrogen.
[0027] The EXAMPLES that follow, which are given to illustrate embodiments of the present invention, include preparations of exemplary monomers and copolymers of this invention. According to the procedures followed, tetrahydrofuran, methylene chloride, chloroform, and toluene were dried by filtration through alumina. Benzophenone, 4-bromoaniline, 1,4-phenylenediamine dihydrochloride, sodium tert-butoxide, rac-2,2′-Bis (diphenylphosphino)-1,1′-binaphthyl, N,N-(dimethylamino) pyridine, di-tertbutylcarbonate, hydroxylamine hydrochloride, tetrabutylammonium tribromide, isophthaloyl dichloride, terephthaloyl chloride, azelaoyl chloride and dodecanedioyl dichloride were purchased from ALDRICH, INC. and used as received without further purification. The UV-Visible spectra were measured using a PERKIN-ELMER LAMDA 19 instrument. The Fourier transform infrared (FTIR) spectra were obtained from KBr pellets using a NICOLET MAGNA-IR 750. The NMR spectra were measured using a 500-MHz BRUKER DRX 500 system.
EXAMPLE 1
[0028]
[0029] The synthesis of tert-butoxy-carbonyl (BOC) protected compound (1) is based on a literature procedure [15]. Benzophenone (3.64 g, 20.0 mmol), N-phenyl-p-phenylenediamine (3.68 g, 20.0 mmol), 5 Å molecular sieves (10 g), and toluene (10 ml) were put into a round bottom flask that was fitted with a reflux condenser and a rubber septum. The mixture was heated to reflux under a positive pressure of argon. After 24 hours, the solvent was decanted from the molecular sieves. The molecular sieves were washed with CH 2 Cl 2 until the filtrate was colorless. The mixture was condensed under vacuum. The residue was dissolved in CH 2 Cl 2 (40 ml) and treated with tetrabutylammonium tribromide (1.69 g, 24.2 mmol). After being stirred for 30 min, a saturated aqueous Na 2 SO 3 solution (40 ml) was added, and the mixture was stirred for 10 min. It was then diluted with 2.0 M NaOH, and the organic layer and aqueous layer were separated. The organic layer was washed with brine (40 ml) and dried over anhydrous Na 2 SO 4 . After being concentrated under vacuum, the residue and 4-methylaminopyridine (4-DMAP) (268 mg, 2.20 mmol) were dissolve in THF (25 ml), and di-butyl-carbonate, (28.6 mmol) in THF (30 ml) was added. After being refluxed for 24 hours, a crude product (7.04 g) was collected under vacuum and purified by washing with isopropanol. Compound (1) was characterized by NMR and IR spectroscopy. 1 H-NMR (500 MHz, CDCl 3 ) δ 7.75 (d, 2H), 7.47-7.35(m, 6H), 7.28 (d, 2H), 7.12 (d,2H), 7.03 (d, 2H), 6.94 (d, 2H), 6.68 (d, 2H), 13.9 (s, 9H). IR (KBr pellet): 2980, 2930, 1700, 1630, 1510, 1340, 1290, 1160, 1060, 957, 833, 764, 602, 540 cm −1 .
EXAMPLE 2
[0030]
[0031] N-(Diphenylmethylene)-4-bromoaniline (2) was synthesized as follows: Benzophenone (45.5 g, 0.250 mol), 4-bromoaniline (47.3 g, 0.275 mol), 5 Å molecular sieves (125 g) and toluene were heated to reflux in a round bottom flask fitted with a reflux condenser, rubber septum, under a positive pressure of argon. After 24 hours, the mixture was filtered and the molecular sieves were washed with diethyl ether until the filtrate was colorless. The filtrate was concentrated under vacuum to give a residue. Yellow crystals of compound (2) were obtained by recrystallizing the residue from methanol. Compound (2) was characterized using NMR and IR spectroscopy. 1 H-NMR (500 MHz, CDCl 3 ): δ 7.77 (d, 2H), 7.54-7.40 (m 3H), 7.33-7.23(m, 5H), 7.12 (d, 2H), 6.63 (d, 2H). IR (KBr pellet): 3050, 3020, 1610, 1480, 1440, 1300, 1230, 1140, 1070, 1010, 957, 918, 825, 779, 702, 663, 609, 583, 525 cm −1 .
EXAMPLE 3
[0032]
[0033] A mixture of 1,4-phenylenediamine dihydrochloride (4.25 g, 12.64 mmol), N-(diphenylmethylene)-4-bromoaniline (2) (1.13 g, 6.24 mmol), sodium tert-butoxide (2.7 g) and rac-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP, 59 mg) in toluene (50 ml) was heated in a round bottom flask with magnetic stirring to a temperature of 80 degrees Celsius under argon. After 24 hours, the mixture was cooled to room temperature and N,N-(dimethylamino) pyridine (76 mg, 0.625 mmol), di-tert-butyl dicarbonate (4.78 g, 21.88 mmol) and tetrahydrofuran (35 ml) were added. The heating was resumed for another 24 hours. Then the mixture was poured into 100 ml of hot ethanol. A gray product precipitated from the solution and was collected by filtration. The crude product was combined with hydroxylamine hydrochloride (1.08 g) in a solvent mixture of pyridine (2.00 ml), chloroform (100 ml), THF (25 ml) and ethanol (12.5 ml) and stirred. After 3 hours, triethylamine (8.7 ml) was added and the resulting suspension was stirred for an additional 3 hours. The suspended mixture was concentrated, and the residue solid was heated in a mixture of 2-propanol (150 ml), chloroform (30 ml), and water (15 ml) for 10 min. The mixture was then allowed to cool to room temperature and stand for 12 h. The precipitated product was collected by filtration and washed, first with water and then with 2-propanol. Compound (3) (2.3 g, 75.0%) was obtained as a solid after drying under vacuum. Compound (3) was characterized by NMR and IR spectroscopy. 1 H-NMR(500 MHz, DMSO-d 6 ): δ 7.06 (s, 4H), 6.83 (d, 4H), 6.51 (d, 4H), 5.12 (s, 4H), 1.34(s, 18H). IR (KBr pellet): 2980, 1710, 1620, 1500, 1330, 1160, 1070, 1010, 957, 833, 771, 702 cm −1 .
EXAMPLE 4
[0034]
[0035] A mixture of compound (3) (490 mg, 1.0 mmol), compound (1) (1.11 g, 2.1 mmol), Pd(OAc) 2 (13.5 mg, 0.06 mmol), sodium tert-butoxide (288 mg, 3.0 mmol), R-BINAP ((R)-(+)-2,2′-Bis(diphenylphosphino)-1′1-binaphthyl, 44 mg, 0.07 mmol) and triethylamine (1.3 ml) in toluene (5 ml) was heated at a temperature of 90 degrees Celsius with magnetic stirring under argon. After 24 hours, heating was stopped temporarily, and N,N-(dimethylamino) pyridine (12.2 mg, 0.1 mmol), di-tert-butyl dicarbonate (873 mg, 4.0 mmol) in tetrahydrofuran (7 ml) were added and the resulting mixture was heated for another 24 hours. The reaction mixture was poured into 10 ml of hot ethanol, and the precipitate was collected by filtration. The precipitate was mixed with ammonium formate (3.14 g), Pd(OH) 2 on carbon (698 mg), THF (60 ml) and ethanol (30 ml) and then heated to 70 degrees for 1.5 hours. The mixture was filtrated and the filtrate was evaporated under vacuum to produce a residue. The residue was dissolved in CH 2 Cl 2 (15 ml) and washed with 2 N aqueous NaOH, followed by brine. The organic layer was evaporated, and a final product was obtained after the residue was washed with a 1:1 solvent mixture of hot hexane and isopropanol. Characterization: 1 H-NMR (500 MHz, CDCl 3 ) δ 7.19-7.08 (m, 20H), 6.97 (d, 4H), 6.62 (d, 4H), 3.68 (s, 4H), 1.42 (s, 54H). IR: 2980, 2930, 1700, 1630, 1510, 1330, 1160, 1060, 957, 849, 771, 548 cm −1 .
EXAMPLE 5
[0036] Synthesis of copolymer of compound (4) and isophthaloyl dichloride. Compound 4 (200 mg, 0.159 mmol, prepared according to EXAMPLE 4) and an equimolar amount of isophthaloyl dichloride, and triethylamine (66 ul) were dissolved in 1.2 ml chloroform at 0 degrees Celsius and then warmed to room temperature. After being stirred overnight, chloroform (10 ml) was added, and the resulting mixture was washed with water and dried over sodium sulfate. The solvent was evaporated under vacuum to produce copolymer I as a colorless powder. The product copolymer I was characterized by NMR and IR spectroscopy. 1 H-NMR (500 MHz, CDCl 3 ): δ9.05 (1H, m), 8.24 (1H, m), 7.92 (2H, m), 7.58 (4H, m), 7.12-7.03 (24H, m), 1.43 (18H, s), 1.42 (36H, s) ppm. IR (KBr pellet: 2980, 2930, 1710, 1600, 1510, 1330, 1300, 1160, 1060, 957, 849, 764, 717, 617, 555 cm −1
EXAMPLE 6
[0037] Synthesis of copolymer of compound (4) and terephthaloyl chloride. Copolymer II was prepared according to the procedure of EXAMPLE 5, with the exception that terephthaloyl chloride was used instead of isophthaloyl dichloride. azelaoyl chloride and dodecanedioyl dichloride. The product copolymer II was characterized by NMR and IR spectroscopy. 1 H-NMR (500 MHz, CDCl 3 ): δ7.72-7.63 (8H, m), 7.16-7.07 (24H, m), 1.43 (18H, s), 1.42 (36H, s) ppm. IR (KBr pellet): 2980, 2940, 1710, 1600, 1510, 1330, 1260, 1160, 1060, 957, 849, 764, 555 cm −1
EXAMPLE 7
[0038] Synthesis of copolymer of compound (4) and azelaoyl chloride. Copolymer III was prepared according to the procedure of EXAMPLE 5, with the exception that azelaoyl chloride was used instead of isophthaloyl dichloride. The product copolymer III was characterized by NMR and IR spectroscopy. 1 H-NMR (500 MHz, CDCl 3 ): δ7.47 (4H, d, J=8.3 Hz), 7.11 (24H, s), 2.28-2.22 (4H, m), 1.67-1.61 (4H, m) 1.43 (54H, s). IR (KBr pellet): 2980, 2930, 1710, 1600, 1510, 1330, 1160, 1060, 957, 849, 764, 548 cm −1
EXAMPLE 8
[0039] Synthesis of copolymer of compound (4) and dodecanedioyl chloride. Copolymer IV was prepared according to the procedure of EXAMPLE 5, with the exception that dodecanedioyl chloride was used instead of isophthaloyl dichloride.
[0040] The product copolymer IV was characterized by NMR and IR spectroscopy. 1 H-NMR (500 MHz, CDCl 3 ): δ 7.45 (4H, d, J=8.4 Hz), 7.12 (24H, s), 2.30-2.27 (4H, m), 1.70-1.64 (4H, m), 1.44 (18H, s). IR (KBr pellet): 2980, 2930, 1710, 1600, 1510, 1330, 1160, 1060, 957, 841, 764, 555 cm −1
[0041] The molecular weights of invention copolymers were determined by gel permeation chromatography using a WATERS GPC system equipped with an AM GPC gel column and KNAUER DRI detector. The copolymers were dissolved in methylene chloride and then 25 μl of solution were injected with a flow rate of 1.0 ml/min under a controlled temperature at 30 degrees Celsius. TABLE 1 summarizes the molecular weight data of copolymers I, II, and III.
TABLE 1 Copolymer M n M w M z M w /M n Copolymer I 2,475 3,550 4,700 1.43 Copolymer II 8,675 17,460 28,100 2.04 Copolymer III 12,200 27,850 47,300 1.43
[0042] As TABLE 1 shows, copolymer 1 exhibits a relatively low molecular weight of about 3,550, averaging 2.5 repeating units (repeat unit M w , 1,384). Copolymer 2 has a much higher molecular weight (17,650), averaging 13 repeat units (repeat unit M w , 1,384). The para-substituted terephthaloyl dichloride used for preparing copolymer II likely allowed the chain to grow much longer than the meta-substituted isophthaloyl dichloride used for preparing copolymer 1. The flexible monomer dodecanedioyl dichloride produced an even higher molecular weight copolymer III (about 27,850), averaging 19 repeat units (repeat unit Mw, 1,448). While not intending to be bound by any particular explanation, it appears that steric effects likely play an important role in determining the length (and therefore, the molecular weight) of copolymer chains.
[0043] Electrochemical characterization of invention copolymer thin films was performed in 1.0 aqueous hydrochloric acid using a CHI660 Electrochemical Workstation. A compact, three-electrode system connected to the CHI660 system that fits in a quartz cell was placed in a UV-VISIBLE sample holder. Transmission measurements were performed at a detector wavelength setting of 600 nm. FIG. 1 shows a cyclic voltammagram of copolymers I-IV and polyaniline. The voltammagram was obtained in an aqueous solution of 1.0 M HCl using Ag/Ag+ as a reference electrode with a scan rate of 50 mV/sec. The copolymers used were cast as thin films from chloroform solutions on a platinum sheet. The films were heated at a temperature of 180 degrees Celsius to remove the protecting BOC groups. As FIG. 1 shows, the cyclic voltammagram for polyaniline has two pairs of redox peaks. One of these peaks corresponds to a transition from the leucoemeraldine base form to emeraldine base form, and the other transition corresponds to the transition from the emeraldine base form to pernigraniline base form. By contrast, each of the copolymers includes three oxidation peaks at voltages of about 0.4 V, about 0.7 V, and about 0.8 V. It is believed that the first oxidation peak corresponds to a transition from the leucoemeraldine form to a first intermediate state, the second peak corresponds to a transition from first intermediate state to a second intermediate state, and the third peak corresponds to the transition from the second intermediate state to the pernigraniline base form. Without wishing to be bound by any particular explanation, it is believed that differences in electrochemical behavior between the copolymers and PANI are due mainly to their differences in chemical structure. For the case of copolymer II, for example, after the oligoaniline is copolymerized with isophthaloyl dichloride to form copolymer II (EXAMPLE 5), the two terminal amine functional groups are not involved in the electrochemical reaction. It is believed that the oligoaniline segments in the copolymer cannot form an exact EB form of two amine groups and two imine groups as PANI can. Instead, as is illustrated in FIG. 2 , the copolymer is transformed from a leucoemeraldine base (LEB) form to an intermediate form (intermediate state I as depicted in FIG. 2 ) having one quinoid ring on each oligoaniline segment. Afterward, the copolymer is transformed to a second intermediate form (intermediate state II as depicted in FIG. 2 ) with two quinoid rings on each oligoaniline segment, and finally to pernigraniline base (PNB) form. By contrast, PANI has only one intermediate form. A possible explanation for this difference is that PANI has many more aniline repeat units than the copolymer has, and as the form of PANI changes from the LEB form to a more oxidized form, it may also have many more quinoid rings in the polymer chains, and therefore a “continuum of forms” (i.e. oxidation states). Studies by MacDiarmid et al. show, however, that LEB conversion to EB and EB conversion to PB occur in one step without passing through an intermediate having a discrete oxidation state [12]. While MacDiarmid states that there are three allowable forms for PANI, our results show only one intermediate form between the LEB form and the PNB form.
[0044] Changes in the oxidation state of the oligoaniline segments in the copolymer backbone were confirmed using Fourier transform infrared (FTIR) spectroscopy and ultraviolet-visible (UV-VIS) spectroscopy. FIG. 3 shows Fourier transform infrared (FTIR) spectra of copolymer II in a 1.0 M solution of hydrochloric acid at different potentials (−0.20 V, 0.45 V, 0.75 V, and 1.00 V) followed by a dedoping treatment in an aqueous solution of 0.1 M ammonium hydroxide. The bands at 1567 and 1492 cm −1 correspond to the stretching of an N═Q═N and N—B—N unit in the polymer chain, respectively (Q represents the quinoid ring and B represents the benzene ring structure). The band at 1650 cm −1 group corresponds to the stretching of the C═O of amide group and the band at 816 cm −1 corresponds to the deformation of CH out of the plane vibrational mode. For polyaniline, the relative intensities of the peak at 1567 cm −1 to the peak at 1492 cm −1 increase with the increasing numbers of quinoid rings in the polymer backbone structure [13]. As seen in FIG. 3 , the intensity peak ratio of 1567 cm −1 /1492 cm −1 increases as the oxidation potential is increased from −0.20 V to 0.45 V to 0.75 V to 1.00 V. This result suggests that the relative numbers of quinoid rings in the oligoaniline segments increases with increasing oxidative potential.
[0045] FIG. 4 shows UV-VIS spectra of the copolymer II thin film oxidized at different potentials (−0.20 V, 0.45 V, 0.75 V and 1.00 V), followed by the dedoping treatment in an ammonium hydroxide aqueous solution. According to FIG. 4 , the copolymer oxidized at −0.20 V shows only one sharp peak at about 330 nm, which suggests that the copolymer is in the leucoemeraldine base form. The copolymers oxidized at 0.45 V, 0.75 V, and 1.00 V show two absorption peaks: one sharp peak at about 330 nm and a second broad band at about 600 nm. The 330 nm peak has been associated with the π-π* transition, and the peak at about 600 nm has been referred to as the “exciton” peak, which is directly associated with the quinone diimine structure [14]. The exciton peak for copolymers (<611 nm) is blue shifted from the exciton peak at 636 nm that is typically observed for PANI EB thin films cast from n-methyl-2-pyrrolidinone solution. The oxidations of the copolymer at 0.45 V, 0.75 V and 1.00 V are associated with exciton peaks at 611 nm, 598 nm, and 583 nm, respectively which suggests that the effective conjugated length increases from a pernigraniline base to an intermediate form I to intermediate form II (see FIG. 2 ).
[0046] Copolymer thin films exhibit electrochromic behavior during a redox cycle. A thin film of copolymer II, for example, undergoes color changes from yellow (at about −0.2 V), to green (at about 0.45 V), to blue (at about 0.75 V), and finally to purple (at about 1.00 V) when a linear potential sweep from −0.20 V to 1.00 V with a scanning rate of 100 mV/S is applied.
[0047] FIG. 5 shows UV-VIS spectra of a thin film of copolymer II oxidized at different potentials on an ITO-glass electrode in an aqueous solution of 1.0 M HCl in a quartz cuvette. The set-up also included a silver wire as a reference electrode and a platinum wire as a counter electrode. The UV-VIS spectra were monitored at a constant voltage. FIG. 5 shows that copolymer oxidized at −0.20 V produces only one peak at 300 nm and a minimum absorbance at the visible and near IR region. This suggests that the copolymer thin film is in the leucoemeraldine state. When the copolymer was oxidized at 0.45 V or 0.75 V, a strong absorbance in the visible and near IR regions was observed. This strong absorbance is believed to result from the delocalization of the radical cation (i.e. the polaron) along the doped copolymer backbone structure. The position and shape of the polaron band are determined mainly by the oxidation states and polymer conformations. The extended chain conformation has an increased conjugated length and a smaller band-gap energy, which leads to delocalization of polarons and a higher intensity of the free-carrier tail into the NIR region. This also suggests that the doped copolymers in the intermediate form I and intermediate form II are conductive.
[0048] The copolymers show a much lower intensity in the free-carrier tail and a blue shift of the polaron band when oxidized at 1.00 V. The UV-VIS spectra suggest that doped pernigraniline (fully oxidized copolymer) is not as conductive as the doped copolymer in intermediate form I and intermediate form II.
[0049] The copolymer thin films of this invention adhered to ITO glass more strongly than did PANI. Copolymer II thin film was electrochemically stable and adhered to ITO even after hundreds of redox cycles. By contrast, the degradation and delamination of PANI occurs much sooner.
[0050] The optical and electrochemical responses of invention copolymer thin films were measured. FIG. 6 shows a plot of the transmittance of a thin film of copolymer II as a square wave potential (−0.2 V and 1.0 V) at applied frequencies of 1 Hz, 0.1 Hz, 0.5 Hz, and 0.05 Hz. The detector wavelength was set at 600 nm and 1.0V. FIG. 6 shows copolymer II switching from a transmittance of 56 percent at −0.2 V to a transmittance of 22 percent at 1.0 V. As the frequency was increased from 0.1 Hz to 1 Hz, the difference in the transmittance between two oxidation states decreased from 34 percent to 9 percent. These results illustrate the conversion of invention copolymer from the fully oxidized form to the fully reduced form.
[0051] Similar results were observed for copolymers I, III, and IV in terms of their electrochromic responses. It is believed that the electrochromic properties of the invention copolymers are largely determined by the diffusion of the electrolyte in and out of the copolymer thin film.
[0052] In summary, electrochromic polyamide copolymers were prepared by condensation N-protected aniline oligomers and diacyl halides. Films cast from solutions of the copolymers displayed electrochromic properties after treatment with acid or heat. The copolymer films were easy to prepare, are electrochemically stable, and adhere to ITO even after hundreds of redox cycles.
[0053] The foregoing description of the invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. While this invention has been described fully and completely, it should be understood that, within the scope of the appended claims, the invention may be practiced otherwise than specifically described.
[0054] The embodiment(s) were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Although the invention has been disclosed with reference to its preferred embodiments, from reading this description those of skill in the art can appreciate changes and modifications that may be made which do not depart from the scope and spirit of the invention as described above and claimed hereafter. It is intended that the scope of the invention be defined by the claims appended hereto.
REFERENCES
[0055] The following references are incorporated by reference herein.
1. A. G. MacDiarmid, S.-L. Mu, N. L. D. Somasiri, W. Wu, Mol. Cryst. Liq. Cryst. (1985), vol. 121, pp. 187-. 2. T. Kobayashi, H. Yoncyama, H. amura, J. Electroanal. Chem. Interfacial Electrochem. (1984), vol. 161, pp. 419-423. 3. (a) K. Kaneto, M. Kaneko, Y. Min, A. G. MacDiarmid, Synth. Met. 1995, 71, 2211. (b) W. Takashima, M. Kaneko, K. Kaneto, A. G. MacDiarmid, Synth. Met. 1995, 71, 2265. (c) J. M. Sansiñena, J. Gao, H.-L. Wang, Adv. Funct. Mater. 2003, 13 (9), 703. (d) J. Gao, J. M. Sansiñena, H.-L. Wang, Chem. Mater. 2003, 15 (12), 2411. 4. (a) D. W. Deberry, J. Electrochem. Soc. 1985, 132, 1022. (b) N. Ahmad, A. G. MacDiarmid, Synth. Met. 1996, 78, 103. (c) W.-K. Lu, R. L. Elsenbaumer, B. Wessling, Synth. Met. 1995, 71, 2163. 5. (a) T. Taka, Synth. Met. 1991, 41, 1177. (b) N. F. Colaneri, L. W. Shacklette, IEEE Trans. Instrum. Meas. 1992, 21, 291. (c) J. Joo, A. J. Epstein, Appl. Phys. Lett. 1994, 65, 2278. 6. (a) L. X. Wang, T. Soczka-Guth, E. Havinga, K. Mullen, Angew. Chem. Int. Ed. Engl. 1996, 35, 1495. 7. (a) W. H. Jang, B. J. Kim, H. J. Choi, M. S. Jhon, Colloid Polym. Sci. 2001, 279, 823. (b) W. Luzny, E. J. Samuelsen, D. Djurado, Y. F. Nicolau, Synth. Met. 1997, 90, 19. (c) Y. Haba, E. Segal, M. Narkis, G. I. Titelman, A. Siegmann, Synth. Met. 1999, 106, 59. (d) S. Kabaya, M. Appel, Y. Haba, G. I. Titelman, A. Schmidt, Macromolecules 1999, 32, 5357. (e) Y. Haba, E. Segal, M. Narkis, G. I. Titelman, A. Siegmann, Synth. Met. 2000, 110, 189. (f) S. J. Su, N. Kuramatto, Synth. Met. 2000, 108, 121. (g) W. Yin, E. Ruchkenstien, Synth. Met. 2000, 108, 39. (I) Y. Cao, A. Andreatta, A. J. Heeger, P. Smith, Polym. 1989, 30, 2305. 8. (a) V. Prevost, A. Petit, F. Pla, Synth. Met. 1999, 104, 79. (b) M. T. Nguyen, P. Kasai, J. L. Miller, A. F. Diaz, Macromolecules 1994, 27, 3625. (c) L. May, M. Zigon, Polym. Bull. 2000, 45, 61. 9. (a) D. Yang. B. R. Mattes, Synth. Met. 1999, 101, 746. (b) H. L. Wang, B. R. Mattes, Synth. Met. 1999, 102, 1333. 10. P. J. Kinlen, B. G. Frushour, Y. Ding, V. Menon, Synth. Met. 1999, 101, 758. 11. (a) F. Garnier, G. Horowitz, X. Peng, D. Fichou, Adv. Mater. 1990, 2, 592. (b) G. Horowitz, D. Fichou, X. Peng, Z. Xu, F. Garnier, Solid State Commun. 1989, 72, 381. 12. J. G. Masters, Y. Sun, A. G. MacDiarmid, A J. Epstein, Synth. Met. 1991, 41-43, 715. 13. (a) F.-L. Lu, F. Wudl, M. Novack, A. J. Hegger, J. Am. Chem. Soc. 1986, 108, 8311. (b) L. W. Shacklette, J. F. Wolf, S. Gould, R. H. Baughman, J. Chem. Phys. 1988, 88, 3955. (c) J. Tang, X. Jing, B. Wang, F. Wang, Synth. Met. 1988, 24, 231. (d) S. Quillard, G. Lourarn, J. P. Buisson, S. Lefrant, J. Masters, A. G. MacDiarmid, Synth. Met. 1993, 55. 475. 14. J. G. Masters, J. M. Ginder, A. G. MacDiarmid, A J. Epstein, J. Chem. Phys. 1992, 96, 4768. 15. (a) R. A. Singer, J. P. Sadighi, S. L. Buchwald, J. Am. Chem. Soc. 1998, 120, 213. (b) J. P. Sadighi, R. A. Singer, S. L. Buchwald, J. Am. Chem. Soc. 1998, 120, 4960. | Electrochromic polyamides are prepared by condensation polymerization. The polyamides are soluble in common organic solvents. Thin films of the polyamides adhere strongly to indium tin oxide (ITO) glass and do not delaminate even after hundred of redox cycles. | 2 |
BACKGROUND OF THE INVENTION
Platelet-activating factor (PAF) has recently been identified as an acetyl glyceryl ether phosphorylcholine (AGEPC), i.e., 1-O-hexadecyl/octadecyl-2-O-acetyl-sn-glyceryl-3-phosphorylcholine (Hanahan, D. S. et al., J. Biol. Chem., 255: 5514, 1980). Even before its chemical identification, PAF has been linked to various biologic activities and pathways making it one of the important mediators responsible for a variety of physiological processes including activation or coagulation of platelets, pathogenesis of immune complex deposition, smooth muscle contraction, inflammation as well as respiratory, cardiovascular and intravascular alterations. These physiological processes are known to be associated with a large group of diseases, for example, inflammatory diseases, cardiovascular disorders, asthma, lung edema, and adult respiratory distress syndrome. It is therefore only natural that more and more scientific investigators are focusing their work on the search of a PAF-antagonist or inhibitor for the treatment and/or the prevention of these common diseases.
The compounds of the present invention are potent and specific PAF-antagonists. They include various substituted 1-benzylidene-indene derivatives of Structure (I) especially where R 2 is an amino sulfonyl group. ##STR1##
These indene derivatives are related to sulindac, a non-steroidal anti-inflammatory drug disclosed by U.S. Pat. Nos. 3,654,349; 3,870,753 and 3,994,600. However, these patents do not disclose the indene derivatives as PAF antagonists nor do they describe the 1-(p-aminosulfonylbenzylidine)-derivatives of the present invention.
Accordingly, it is the object of the present invention to provide novel derivatives of Structure (I) as specific PAF-antagonists.
Another object of this invention is to provide processes for the preparation of novel derivatives of Structure (I).
A further object of this invention is to provide a pharmaceutically acceptable composition containing at least one of the compounds of Structure (I) as the active ingredient for the treatment of diseases which are subject to the mediation of a PAF-antagonist.
Still a further object of this invention is to provide a method of treatment comprising the administration of a therapeutically sufficient amount of at least one of the compounds of Structure (I) to a patient suffering from various skeletal-muscular disorders including but not limited to inflammation, e.g., osteoarthritis, rheumatoid arthritis and gout, hypertension; cardiovascular disorder; asthma; bronchitis; lung edema; or adult respiratory distress syndrome.
DETAILED DESCRIPTION OF THE INVENTION
A. Scope of the Invention
This invention relates to specific PAF-antagonists of the structural formula (I) ##STR2## wherein R is H or loweralkyl especially C 1-6 alkyl, for example, methyl, ethyl, isopropyl, n-propyl, butyl, pentyl or hexyl;
R 1 is
(a) --CHR 4 COOR wherein R 4 is hydrogen or loweralkyl;
(b) --(CH 2 ) m R 5 wherein R 5 represents R, OR, SR, S-phenyl(unsubstituted or substituted), SOR, SO 2 R, ##STR3## --O--COR, --NHCOR, --NRR 4 , halo especially fluoro; and m is 1 to 4; (c) --CH═CHR;
(d) --CH 2 CONRR 4 ; or
(e) --CHOH--CHOH--R;
R 2 is
(a) --NHSO 2 R 6 where R 6 represents R, --CF 3 , unsubstituted or substituted phenyl, for example, phenyl, p-methoxyphenyl, p-chlorophenyl, m-trifluoromethylphenyl or the like;
(b) hydrogen;
(c) lower alkyl; ##STR4## (e) --NRR 4 ; (f) --OR 7 wherein R 7 is H, R, loweralkenyl especially C 1-6 alkenyl such as --CH 2 --CH═CH 2 ; lower alkynyl especially C 1-6 alkynyl such as --CH 2 --C.tbd.CH;
(g) --(CH 2 ) m O-- when two adjacent R 2 are joined together and where m represents 2 or 3;
(h) halo especially fluoro, chloro and bromo;
(i) --SR 6 ;
(j) --SOR 6 ;
(k) --SO 2 R 6 ;
(l) --SO 2 NRR 4 ;
(m) --SO 2 NHY wherein Y is a heterocycle as defined below;
(n) --SO 2 NHX wherein X is --CONH 2 , CSNH 2 or --C(═NH)NH 2 ;
(o) --SO 2 CF 3 ;
(p) --CN;
(q) --SO 2 NR 4 COR 6 ; or
(r) --COOR 6 ;
n is 1, 2 or 3; and
R 3 is
(a) hydrogen;
(b) lower alkyl especially C 1-6 alkyl;
(c) --OR 7 ;
(d) --O--(CH 2 ) m -- when two adjacent R 3 are joined together and wherein m is 2 or 3;
(e) halo especially F;
(f) --O--CH 2 --phenyl or substituted phenyl;
(g) --CH 2 OR 6 ;
(h) --SR 6 ;
(i) --S--CH 2 --phenyl or substituted phenyl;
(j) --CH 2 --S--R 6 ;
(k) --SOR 6 ;
(l) --SO 2 R 6 ;
(m) --OCOR 6 ;
(n) --NRR 4 or --NH 2 ;
(o) --NR 4 COOR 6 ;
(p) --NHCOR 6 ; or
(q) --OCOOR 6 .
Preferably, the specific PAF-antagonists of this invention are of the structural Formula (II) ##STR5## wherein R 1 , R 2 and R 3 are as previously defined.
Even more preferably, the specific PAF-antagonists of this invention are of the structural Formula (III) ##STR6## wherein n and R 5 are as previously defined;
R 2 is
(a) --SO 2 NRR 4 ;
(b) --SOR 6 ;
(c) --SO 2 R 6 ;
(d) --SO 2 NHX wherein X represents --CONH 2 , --CSNH 2 , --C(═NH)NH 2 --SO 2 NHY wherein Y represents a heterocycle e.g., ##STR7## (e) --SO 2 CF 3 ; (f) --SO 2 NHCOR 6 ; or
(g) --OR 7 ; and
R 3 is
(a) hydrogen;
(b) loweralkyl;
(c) --OR 7 ;
(d) --O(CH 2 ) m -- when two adjacent R 3 are joined together and m is 2 or 3;
(e) --OCH 2 --phenyl or substituted phenyl;
(f) --F;
(g) --SR 6 ;
(h) --OCOR 6 ;
(i) --NHCOR 6 ; or
(j) --OCOOR 6 .
B. Preparation of the compounds within the scope of the invention
As discussed above, most PAF-antagonists of this invention are known compounds related to sulindac except where R 2 is --OR 7 , --SO 2 NRR 4 , SO 2 NHC(NH)NH 2 , SO 2 NHCONH 2 , and SO 2 NR 4 COR 6 . These analogs, however, can be easily prepared from the corresponding indenes and the appropriately substituted benzaldehydes. For example, ##STR8##
EXAMPLE 1
Z(cis) and E(trans) 1-(4-Aminosulfonylphenyl)methylene-5-substituted-2-methyl-1H-3-indenylacetic acids and analogs
Step 1
Preparation of E and Z 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenylacetic acids (2a and 3a)
To a solution of 5-methoxy-2-methyl-3-indenylacetic acid (1a) (3.95 g) in 90% methanol (24 ml) containing 85% potassium hydroxide (2.7 g) was added a solution of p-aminosulfonylbenzaldehyde (3.70 g) in 90% methanol (24 ml). The resulting mixture was refluxed under nitrogen for 4-6 hours. A solution of 50% aqueous acetic acid (50 ml) was then added to the reaction mixture during 40 minutes at 50°-60° C. The crystals were collected after aging at 15° C. for 1 hour. The crude product was recrystallized five times from acetone-hexane to give pure Z form of 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenylacetic acid (2a) (4.0 g, 57%): m.p. 224°-225° C.; R f =0.45 (silica gel, 10% MeOH in CHCl 3 developed 3-4 times).
Anal. Calcd for C 20 H 19 NO 5 S: C, 62.33; H, 4.97; N, 3.63; S, 8.32. Found: C, 62.48; H, 5.06; N, 3.60; S, 8.15.
The E acid enriched mother liquor from above (E:Z=1:4, 100 mg) was purified via preparative tlc using 500 μm silica gel plates (3-4 mg per plate) developed 5-6 times with 10% methanol in chloroform to give the E form of 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl acetic acid (3a); m.p. 223°-225° C.; R f =0.35 (silica gel, 10% MeOH in CHCl 3 developed 3-4 times); mass spectrum, m/e 385; nmr (300 MHz, CD 3 OD) δ1.80 (s, 3H, C-2-Me), (for cis C-2-Me: 2.18).
Step 2
Preparation of E and Z methyl 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenylacetate (4a and 5a)
A solution of the E acid 3a (950 mg) and toluenesulfonic acid monohydrate (200 mg) in methanol (60 ml) was refluxed for 1-2 hours. The solution was filtered and the filtrate was concentrated to 30 ml. After cooling at 0° to 5° for 1 hour, the crystals were collected and dried. The crude ester was recrystallized from acetonitrile to give the pure E methyl 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenylacetate 5a (850 mg, 86%): m.p. 169.5°-171.0° C.
Anal. Calcd for C 21 H 21 NO 5 S: C, 63.14; H, 5.30; N, B 3.51; S, 8.03. Found: C, 62.97; H, 5.27; N, 3.66; S, 8.19.
In the same manner, the Z acid 2a was converted to the Z methyl 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenylacetate (4a): m.p. 179.5°-181.0° C.
Anal. Calcd for C 21 H 21 NO 5 S: C, 63.14; H, 5.30; N, 3.51; S, 8.03. Found: C, 63.02; H, 5.35; N, 3.37; S, 7.91.
Following substantially the same procedures as described in Steps 1 and 2, but starting with 5-fluoro-2-methyl-3-indenylacetic acid, the following analogs were prepared:
(1) Z1-(4-Aminosulfonylphenyl)methylene-5-fluoro-2-methyl-1H-3-indenylacetic acid (2b); m.p. 242.5°-244.0° C.
Anal. Calcd for C 19 H 16 FNO 4 S: C, 61.12; H, 4.32; N, 3.75; F, 5.09; S, 8.59. Found: C, 61.05; H, 4.43; N, 3.61; F, 5.09; S, 8.31.
(2) Z Methyl 1-(4-aminosulfonylphenyl)methylene-5-fluoro-2-methyl-1H-3-indenylacetate (4b); m.p. 183°-184° C.
Anal. Calcd for C 19 H 16 FNO 4 S: C, 62.01; H, 4.68; N, 3.62; F, 4.90; S, 8.28. Found: C, 62.11; H, 4.69; N, 3.70; F, 5.17; S, 8.35.
(3) E-Methyl 1-(4-aminosulfonylphenyl)methylene-5-fluoro-2-methyl-1H-3-indenylacetate (5b); m.p. 206.5°-208.5° C.
Anal. Calcd for C 20 H 18 FNO 4 S: C, 62.01; H, 4.68; N, 3.62; F, 4.90; S, 8.28. Found: C, 61.60; H, 4.54; N, 3.52; F, 5.12; S, 8.46.
Step 3a
N-Methylation of 4a and 5a with diazomethane to form methyl 1-(4-(N-methylaminosulfonyl)phenyl)methylene-5-methoxy-2-methyl-1H-3-indenylacetate and its N,N-dimethyl derivative
A solution of 4a (100 mg) in methanol (20 ml) was treated with excess diazomethane ether solution to give two products. They are separated via preparative tlc using 1500 μm silica gel plates developed 3 times with 5% ethyl acetate in chloroform to give Z methyl 1-(4-(N-methylaminosulfonyl)phenyl)methylene-5-methoxy-2-methyl-1H-3-indenylacetate (6a) (30 mg, 29% yield): m.p. 167°-169° C.
Anal. Calcd for C 22 H 23 NO 5 S.1/2H 2 O: C, 62.54; H, 5.73; N, 3.31; S, 7.59. Found: C, 62.55; H, 5.52; N, 3.27; S, 7.65.
and Z methyl 1-(4-(N,N-dimethylaminosulfonyl)phenyl)methylene-5-methoxy-2-methyl-1H-3-indenylacetate (6b) (60 mg, 56% yield): m.p. 163°-164° C.
Anal. Calcd for C 23 H 25 NO 5 S.1/5H 2 O: C, 64.08; H, 5.94; N, 3.25; S, 7.44. Found: C, 64.02; H, 5.91; N, 3.15; S, 7.30.
Following the same procedure as described in Step 3a but starting with 5a or 5b, the following compounds were prepared:
(1) E Methyl 1-(4-(N-methylaminosulfonyl)phenyl)methylene-5-methoxy-2-methyl-1H-3-indenylacetate (7a): m.p. 151.5°-153.5° C.
Anal. Calcd for C 22 H 23 NO 5 S: C, 63.90; H, 5.61; N, 3.39; S, 7.75. Found: C, 64.00; H, 5.65; N, 3.27; S, 7.66.
(2) E Methyl 1-[4-(N-methylaminosulfonyl)phenyl]-methylene-5-fluoro-2-methyl-1H-3-indenylacetate (7b): m.p. 168.5°-170.0° C.
Anal. Calcd for C 21 H 20 FNO 4 S.1/5H 2 O: C, 62.27; H, 5.08; N, 3.46. Found: C, 61.99; H, 4.64; N, 3.25.
Step 3b
Acetylation of 4a to form Z methyl 1-[4-(N-acetylaminosulfonyl)phenyl]methylene-5-methoxy-2-methyl-1H-3-indenylacetate (6c)
A solution of 4a (100 mg) in pyridine (5 ml) was added acetic anhydride (2 ml). The mixture was heated at 110° for 1 hour and concentrated in vacuo. The crude mixture was purified via preparative tlc using 2000 μm silica gel plates developed with 30% ethyl acetate in chloroform. The isolated product was recrystallized from acetone-hexane to give pure Z methyl 1-[4-(N-acetylaminosulfonyl)phenyl]methylene-5-methoxy-2-methyl-1H-3-indenylacetate (55 mg, 50%): m.p. 172.5°-174.5° C.
Anal. Calcd for C 23 H 23 NO 6 S: C, 62.57; H, 5.25; N, 3.17; S, 7.26. Found: C, 62.69; H, 5.25; N, 3.15; S, 7.25.
Following the same procedure as described in Steps 1-3, but starting with an appropriate substrate, there were prepared the following compounds:
(1) From 5-methoxy-2-methyl-1H-3-indenylacetic acid and 3,4-dimethoxybenzaldehyde to Z methyl 1-(3,4-dimethoxyphenyl)methylene-5-methoxy-2-methyl-1H-3-indenylacetate (29a); m.p. 101°-103° C. and E methyl 1-(3,4-dimethoxyphenyl)methylene-5-methoxy-2-methyl-1H-3-indenylacetate (30 a); m.p. 131°-133° C.
(2) From treating 5-methoxy-1H-3-indenylacetic acid and 4-aminosulfonylbenzaldehyde to the following compounds:
(a) E 1-(4-aminosulfonylphenyl)methylene-5-methoxy-1H-3-indenylacetic acid (3c); m.p. 211°-213° C.
Anal. Calcd for C 19 H 17 NO 5 S.1/8H 2 O: C, 61.07; H, 4.65; N, 3.75. Found: C, 60.86; H, 4.54; N, 3.59.
(b) E Methyl 1-(4-aminosulfonylphenyl)methylene-5-methoxy-1H-3-indenylacetate (5c); m.p. 174°-176° C.
Anal. Calcd for C 20 H 19 NO 5 S: C, 62.33; H, 4.97; N, 3.63; S, 8.31. Found: C, 62.29; H, 4.96; N, 3.35; S, 8.35.
(c) E Methyl 1-[4-(N-methylsulfonylphenyl)methylene-5-methoxy-1H-3-indenylacetate (7c); m.p. 151°-152.5° C.
Anal. Calcd for C 21 H 21 NO 5 S.1/2H 2 O: C, 61.75; H, 5.43; N, 3.43. Found: C, 61.42; H, 5.16; N, 3.13. ##STR9##
EXAMPLE 2
E and Z 1-(4-Substituted aminophenyl)methylene-5-substituted-2-methyl-1H-3-indenylacetic acids and analogs
Step 1
Preparation of Z 1-(4-aminophenylmethylene-5-fluoro-2-methyl-1H-3-indenylacetic acid (8b)
Following the procedure of Example 1, Step 1, but substituting for the compound 1a and p-aminosulfonylbenzaldehyde used therein, an equivalent amount of 5-fluoro-2-methyl-3-indenylacetic acid and p-acetamidobenzaldehyde, there was obtained Z 1-(4-aminophenyl)methylene-5-fluoro-2-methyl-1H-3-indenylacetic acid (8b); m.p. 214.0°-215.5° C.
Anal. Calcd for C 19 H 16 FNO 2 : C, 73.77; H, 5.21; N, 4.53; F, 6.14. Found: C, 74.00; H, 5.46; N, 4.22; F, 5.65.
Step 2
Preparation of Z methyl 1-(4-aminophenyl)methylene-5-fluoro-2-methyl-1H-3-indenylacetate (10b)
Following the procedure of Example 1, Step 2, but substituting the compound 3a used therein, an equivalent of 8b, there was obtained Z methyl 1-(4-aminophenyl)methylene-5-fluoro-2-methyl-1H-3-indenylacetate (10b); m.p. 102.5°-103.5° C.
Anal. Calcd for C 20 H 18 FNO 2 : C, 74.29; H, 5.61; N, 4.33; F, 5.88. Found: C, 73.86; H, 5.39; N, 4.47; F, 5.55.
Step 3
Mesylation of 10b to form Z methyl 1-(4-N-mesylaminophenyl))methylene-5-fluoro-2-methyl-1H-3-indenylacetate (12b)
To a solution of compound 10b (100 mg) in methylene chloride (20 ml) was added pyridine (55 mg) at 5°-10° and then methanesulfonylchloride (80 mg) dropwise. The mixture was stirred at room temperature for 31/2 hours. Purification of the mixture via preparative tlc gave pure Z methyl 1-(4-(N-mesylaminophenyl))methylene-5-fluoro-2-methyl-1H-3-indenylacetate (12b) (110 mg, 88% yield); m.p. 160°-162° C.
Anal. Calcd for C 21 H 20 FNO 4 S: C, 62.83; H, 5.02; N, 3.49; F, 4.73; S, 7.99. Found: C, 63.12; H, 5.01; N, 3.45; F, 4.58; S, 8.13.
Following similar procedures as described in Example 2, Steps 1-3, there was obtained Z methyl 1-(4-(N-mesylaminophenyl))methylene-5-methoxy-2-methyl-1H-3-indenylacetate (12a); m.p. 159°-160° C.
Anal. Calcd for C 22 H 23 NO 5 S: C, 63.91; H, 5.61; N, 3.39; S, 7.75. Found: C, 63.42; H, 5.50; N, 3.26; S, 8.15. ##STR10##
EXAMPLE 3
E and Z 1-(Substituted phenyl)methylene-5-substituted-2-methyl-1H-3-indenyl-(2-methoxy)ethane
Step 1
Preparation of methyl 5-fluoro-2-methyl-1H-3-indenylacetate (14b)
Following the procedure of Example 1, Step 2, but substituting the compound 3a used therein, an equivalent of 1b, there was produced methyl 5-fluoro-2-methyl-3-indenylacetate (14b) as an oil, which was used in the next step without further purification.
Step 2
LAH reduction of 14b to form 5-fluoro-2-methyl-1H-3-indenyl-(2-hydroxy)ethane (15b)
To a solution of 14b (24 g) in dry THF (300 ml), LiAlH 4 (6.9 g) was added in portions. The mixture was stirred at room temperature for 1.5 hours. Excess LiAlH 4 (LAH) was destroyed with saturated Na 2 SO 4 solution. The organic phase was concentrated in vacuo, and the crude product was purified via silica gel column chromatography eluting with methylene chloride. The product was recrystallized from hexane to give 5-fluoro-2-methyl-1H-3-indenyl-(2-hydroxy)ethane (15b) (14.9 g, 63% yield): m.p. 65°-66.5° C.
Anal. Calcd. for C 12 H 13 FO: C, 74.98; H, 6.82; F, 9.88. Found: C, 74.62; H, 6.64; F, 9.76.
Step 3
Diazomethane methylation of 15b to methyl 5-fluoro-2-methyl-1H-3-indenyl-(2-methoxy)ethane (16b)
To a solution of compound 15b (1.84 g) in methylene chloride (50 ml) containing 5 drops of BF 3 -etherate was added a solution of freshly prepared diazomethane ether solution (80 ml, from nitrosomethyl urea). The solution was stirred for 1/2 hour at room temperature and passed through a short column to remove most of the impurities, and the crude product isolated was used directly in the next step.
Step 4
Preparation of Z and E 1-(4-aminosulfonylphenyl)methylene-5-fluoro-2-methyl-1H-3-indenyl-(2-methoxy)ethane (17b and 18b)
Following the procedure of Example 1, Step 1, but substituting for the compound 1a used therein, an equivalent of 16b, there were produced in 57% yield Z 1-(4-aminosulfonylphenyl)methylene-5-fluoro-2-methyl-1H-3-indenyl-(2-methoxy)ethane (17b), m.p. 145°-147° C.
Anal. Calcd. for C 20 H 20 FNO 3 S: C, 64.33; H, 5.40; N, 3.75; F, 5.09; S, 8.58. Found: C, 64.13; H, 5.19; N, 3.88; F, 5.13; S, 8.47.
and E 1-(4-aminosulfonylphenyl)methylene-5-fluoro-2-methyl-1H-3-indenyl-(2-methoxy)ethane (18b), m.p. 185°-186° C.
Anal. Calcd. for C 20 H 20 FNO 3 S: C, 64.33; H, 5.40; N, 3.75; F, 5.09; S, 8.58. Found: C, 64.06; H, 5.19; N, 3.77; F, 5.17; S, 8.48.
Following the same procedures as described in Step 1-4, the following compounds were prepared:
(1) 5-methoxy-2-methyl-1H-3-indenyl-(2-hydroxy)ethane (15a):
Anal. Calcd. for C 13 H 16 O 2 1/4H 2 O: C, 74.81; H, 7.97. Found: C, 74.46; H, 7.86.
(2) Z 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methoxy)ethane (17a), m.p. 161.5°-162.5° C.
Anal. Calcd. for C 21 H 23 NO 4 S C, 65.43; H, 6.01; N, 3.63; S, 8.32. Found: C, 65.27; H, 6.05; N, 3.60; S, 8.25.
(3) E 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methoxy)ethane (18a), m.p. 138.5°-140.0° C.
Anal. Calcd. for C 21 H 23 NO 4 S C, 65.43; H, 6.01; N, 3.63; S, 8.32. Found: C, 65.79; H, 6.05; N, 3.62; S, 8.37. ##STR11##
EXAMPLE 4
E and Z 1-(4-Aminosulfonylphenyl)methylene-5-substituted-2-methyl-1H-3-indenyl-(2-methanesulfonyloxy)ethane
Step 1
Preparation of 2-methyl-5-methoxy-1H-3-indenyl-(2-methanesulfonyloxy)ethane (19a)
To a solution of the alcohol 15a (6.0 g) and triethyl amine (6.5 ml) in methylene chloride (60 ml) at room temperature was added a solution of methanesulfonyl chloride (3.0 ml) in methylene chloride (30 ml) dropwise. The mixture was stirred at room temperature for 30 minutes and the precipitates were removed by filtration. The filtrate was evaporated to dryness and the residue was purified via a silica gel column to give 2-methyl-5-methoxy-1H-3-indenyl-(2-methanesulfonyloxy)ethane (19a) (5.7 g, 68% yield): m.p. 84.5°-86.0° C.
Anal. Calcd. for C 14 H 18 O 4 S: C, 59.57; H, 6.43; S, 11.36. Found: C, 59.34; H, 6.64; S, 11.34.
Following the same procedure of Step 1 but starting with 15b, there was prepared 5-fluoro-2-methyl-1H-3-indenyl-(2-methanesulfonyloxy)ethane (19b): m.p. 65.0°-66.5° C.
Anal. Calcd. for C 12 H 13 OF: C, 74.98; H, 6.82; F, 9.88. Found: C, 74.62; H, 6.64; F, 9.76.
Step 2
Preparation of 2-methyl-5-methoxy-1H-3-indenyl-(2-methylthio)ethane (20a)
To a saturated solution of methyl mercaptan in absolute ethanol (50 ml) containing potassium tert-butoxide (0.994 g) was added the mesylate 19a (2.5 g). The reaction mixture was refluxed for 30 minutes and evaporated to dryness. The residue was purified via preparative tlc using 1500 μm silica gel plates developed with 20% hexane in methylene chloride to give pure 2-methyl-5-methoxy-1H-3-indenyl-(2-methylthio)ethane (20a) (1.79 g, 86% yield).
Following the same procedure of Step 2, 19b was converted by reaction with phenylmercaptan to 5-fluoro-2-methyl-1H-3-indenyl-(2-phenylthio)ethane (20b).
Anal. Calcd. for C 19 H 20 OS.1/6H 2 O: C, 76.21; H, 6.79; S, 10.71. Found: C, 76.18; H, 6.78; S, 10.67.
Step 3
Preparation of Z and E 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methylthio)ethane (21a and 22a)
Following the procedure of Example 1, Step 1, but substituting the compound 1a used therein an equivalent amount of 20a, there was obtained Z 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methylthio)ethane (21a): m.p. 178.5°-180.5° C.
Anal. Calcd. for C 21 H 23 NO 3 S 2 : C, 62.82; H, 5.77; N, 3.49; S, 15.97. Found: C, 62.52; H, 5.79; N, 3.36; S, 15.94.
and E 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methylthio)ethane (22a): m.p. 172.5°-173.5° C.
Anal. Calcd. for C 21 H 23 NO 3 S 2 : C, 62.82; H, 5.77; N, 3.49; S, 15.97. Found: C, 62.79; H, 5.85; N, 3.44; S, 15.84.
Following the same procedures as described in Steps 1-3, there were prepared the following compounds:
(1) Z 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-phenylthio)ethane (23a).
Anal. Calcd. for C 26 H 25 NO 3 S 2 .1/4H 2 O: C, 66.71; H, 5.47; N, 2.99. Found: C, 66.86; H, 5.35; N, 3.09.
(2) E 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-phenylthio)ethane (24a).
Anal. Calcd. for C 26 H 25 NO 3 S 2 .1/2H 2 O: C, 66.07; H, 5.50; N, 2.96. Found: C, 66.15; H, 5.34; N, 3.09.
(3) Z 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-[2-(N-imidazolyl)]ethane (25a): m.p. 240.0°-242.0° C.
Anal. Calcd. for C 23 H 23 N 3 O 3 S: C, 65.54; H, 5.50; N, 9.97; S, 7.66. Found: C, 65.63; H, 5.41; N, 9.78; S, 7.62.
(4) E 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-[2-(N-imidazolyl]ethane (26a): m.p. 197.0°-199.0° C.
Anal. Calcd. for C 23 H 23 N 3 O 3 S.H 2 O: C, 62.86; H, 5.69; N, 9.57. Found: C, 62.75; H, 5.24; N, 9.43.
(5) Z 1-(4-aminosulfonyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-hydroxy)ethane (27a): m.p. 170.0°-171.5° C.
Anal. Calcd. for C 20 H 21 NO 4 S.1/4H 2 O: C, 63.90; H, 5.76; N, 3.72. Found: C, 64.06; H, 5.74; N, 3.57.
(6) E 1-(4-aminosulfonyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-hydroxy)ethane (28a): m.p. 185.5°-187.0° C.
Anal. Calcd. for C 20 H 21 NO 4 S.1/3H 2 O: C, 63.64; H, 5.78; N, 3.71. Found: C, 63.35; H, 5.88; N, 3.33. ##STR12##
EXAMPLE 5
E and Z 1-(4-Aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methylsulfinyl)-and-(2-methylsulfonyl)ethanes
Step 1
Preparation of Z 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methylsulfinyl)ethane (31a)
To a solution of 21a (250 mg) in methanol (35 ml) at 0°-5° C. was added a solution of m-chloroperbenzoic acid (90 mg) in methanol (3 ml). The solution was stirred at 5° C. for 1/2 hour and room temperature for 1 hour. Purification of the crude product via preparative tlc 1000 mm silica gel plates developed three times with 2.5% methanol in methylene chloride gave pure Z 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methylsulfinyl)ethane (31a) (140 mg, 54% yield): m.p. 205.0°-207.0° C.
Anal. Calcd. for C 21 H 23 NO 4 S 2 .H 2 O: C, 57.90; H, 5.78; N, 3.22; S, 14.71. Found: C, 58.08; H, 5.33; N, 3.28; S, 14.67.
Step 2
Preparation of Z 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methoxysulfonyl)ethane (32a)
Following the procedure of Example 5, Step 1, but substituting one equivalent of MCPBA used therein, two equivalent of MCPBA there was obtained Z 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methylsulfonyl)ethane (32a): m.p. 181.0°-182.5° C.
Anal. Calcd. for C 21 H 23 NO 5 S 2 .1/5H 2 O: C, 57.70; H, 5.40; N, 3.21. Found: C, 57.55; H, 5.51; N, 3.30.
Following the same procedures as described in Example 5, Steps 1-2, but starting with the E form (22a), there were prepared the following compounds:
(1) E 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methylsulfinyl)ethane (33a): m.p. 189.0°-190.5° C.
Anal. Calcd. for C 21 H 23 NO 4 S 2 .1/5H 2 O: C, 59.89; H, 5.60; N, 3.33; S, 15.23. Found: C, 60.00; H, 5.40; N, 3.61; S, 15.14.
(2) E 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methylsulfonyl)ethane (34a): m.p. 190.0°-192.0° C.
Anal. Calcd. for C 21 H 23 NO 5 S 2 .1/5H 2 O: C, 57.70; H, 5.40; N, 3.21. Found: C, 57.74; H, 5.17; N, 3.07. ##STR13##
EXAMPLE 6
E and Z 1-(4-Substitutedphenyl)methylene-5-fluoro-2-methyl-1H-3-indenyl-(2-acetamido)ethanes
Step 1
Preparation of Z 1-(4-methylsulfinylphenyl)methylene-5-fluoro-2-methyl-1H-3-indenyl-2-acetamido)ethane (36b)
Following the procedure of Example 5, Step 1, but substituting the compound 21a used therein, an equivalent amount of 35b, there was produced compound Z 1-(4-methylsulfinylphenyl)methylene-5-fluoro-2-methyl-1H-3-indenyl-(2-acetamido)ethane (36b): m.p. 135°-137° C.
Anal. Calcd. for C 22 H 22 FNO 2 S.1/2H 2 O: C, 67.06; H, 5.90; N, 3.56. Found: C, 67.04; H, 5.54; N, 3.35.
Step 2
Preparation of Z 1-(4-methylsulfonylphenyl)methylene-5-fluoro-2-methyl-1H-3-indenyl-(2-acetamido)ethane (36c)
Following the procedure of Example 5, Step 2, but substituting the compound 21a used therein, an equivalent amount of 35b there was produced Z 1-(4-methylsulfonylphenyl)methylene-5-fluoro-2-methyl-1H-3-indenyl-(2-acetamido)ethane (36c): m.p. 193.5°-194.5° C.
Anal. Calcd. for C 22 H 22 FNO 3 S: C, 66.14; H, 5.55; N, 3.51; F, 4.76; S, 8.03. Found: C, 66.17; H, 5.56; N, 3.55; F, 4.86; S, 8.32.
Similarly by employing the same procedures as described above, there was prepared the following compound.
(1) E 1-(4-methylsulfonylphenyl)methylene-5-fluoro-2-methyl-1H-3-indenyl-(2-acetamido)ethane (38c): m.p. 213.5°-215.0° C.
Anal. Calcd. for C 22 H 22 FNO 3 S: C: 66.14; H, 5.55; N, 3.51; F, 4.76; S, 8.03. Found: C, 66.16; H, 5.54; N, 3.59; F, 4.66; S, 8.03. ##STR14##
EXAMPLE 7
Photoisomerization of Z form indenes to E form indenes
Method A
A solution of the Z methyl ether, Z 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methoxy)ethane (17a) (650 mg) and benzophenone (2.0 g) in acetonitrile was degassed 2-3 times in a pyrex round-bottomed flask and irradiated with a 3000 A lamp under nitrogen for 89 hours. The resulting photolysate was purified via preparative tlc using 1000 μm silica gel plate (40 mg per plate) developed 3-5 times with 3% acetone in methylene chloride to give E 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methoxy)ethane (18a): (66 mg, 10% yield): m.p. 138.5°-140.0° C.
Anal. Calcd. for C 21 H 23 NO 4 S: C, 65.43; H, 6.01; N, 3.63; S, 8.32. Found: C, 65.09; H, 6.08; N, 3.53; S, 8.16.
Method B
A solution of the Z methyl ether, E 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methoxy)ethane (17a) (700 mg) and benzophenone (3.5 g) was irradiated with a medium pressure Hanovia lamp (450 watt) through a quartz well for 75 minutes under nitrogen. Following the work up procedure of Method A, there was obtained E 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-(2-methoxy)ethane (18a) (90 mg, 13% yield): m.p. 139.5°-140.0° C.
Anal. Calcd. for C 21 H 23 NO 4 S: C, 65.43; H, 6.01; N, 3.63; S, 8.32. Found: C, 65.30; H, 5.99; N, 3.62; S, 8.31.
Similarly, the Z imidazol derivative, 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-[2-(N-imidazolyl)]ethane (25a) was converted to E 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl-[2(N-imidazolyl)]ethane (26a); m.p. 216.0°-217.0° C.
Anal. Calcd. C 23 H 23 N 3 O 3 S: C, 65.54; H, 5.50; N, 9.97; S, 7.66. Found: C, 65.22; H, 5.52; N, 9.87; S, 7.45.
C. Utility of the compounds within the scope of the invention
This invention also relates to a method of treatment for patients (or mammalian animals raised in the diary, meat, or fur industries or as pets) suffering from disorders or diseases which can be attributed to PAF as previously described, and more specifically, a method of treatment involving the administration of compound (I) as the active constituent.
Accordingly, compound (I) can be used among other things to reduce inflammation, to correct respiratory, cardiovascular, and intravascular alterations or disorders, and to regulate the activation or coagulation of platelets, the pathogenesis of immune complex deposition and smooth muscle contractions.
For the treatment of inflammation, cardiovascular disorder, asthma, or other diseases mediated by the PAF, compound (I) may be administered orally, topically, parenterally, by inhalation spray or rectally in dosage unit formulations containing conventional non-toxic pharmaceutically acceptable carriers, adjuvants and vehicles. The term parenteral as used herein includes subcutaneous injections, intravenous, intramuscular, intrasternal injection or infusion techniques. In addition to the treatment of warm-blooded animals such as horses, cattle, sheep, dogs, cats, etc., the compounds of the invention are effective in the treatment of humans.
The pharmaceutical compositions containing the active ingredient may be in a form suitable for oral use, for example, as tablets, troches, lozenges, aqueous or oily suspensions, dispersible powders or granules, emulsions, hard or soft capsules, or syrups or elixirs. Compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected from the group consisting of sweetening agents, flavoring agents, coloring agents and preserving agents in order to provide pharmaceutically elegant and palatable preparation. Tablets contain the active ingredient in admixture with non-toxic pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients may be for example, inert diluents, such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, corn starch, or alginic acid; binding agents, for example starch, gelatin or acacia, and lubricating agents, for example magnesium stearate, stearic acid or talc. The tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate may be employed. They may also be coated by the techniques described in the U.S. Pat. Nos. 4,256,108; 4,160,452; and 4,265,874 to form osmotic therapeutic tablets for controlled release.
Formulations for oral use may also be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, for example peanut oil, liquid paraffin, or olive oil.
Aqueous suspensions contain the active materials in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients are suspending agents, for example sodium carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia; dispersing or wetting agents may be a naturally-occurring phosphatide, for example lecithin, or condensation products of an alkylene oxide with fatty acids, for example polyoxyethylene stearate, or condensation products of ethylene oxide with long chain aliphatic alcohols, for example heptadecaethyleneoxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, for example polyoxyethylene sorbitan monooleate. The aqueous suspensions may also contain one or more preservatives, for example ethyl, or n-propyl, p-hydroxybenzoate, one or more coloring agents, one or more flavoring agents, and one or more sweetening agents, such as sucrose or saccharin.
Oily suspension may be formulated by suspending the active ingredient in a vegetable oil, for example arachis oil, olive oil, sesame oil or coconut oil, or in a mineral oil such as liquid paraffin. The oily suspensions may contain a thickening agent, for example beeswax, hard paraffin or cetyl alcohol. Sweetening agents such as those set forth above, and flavoring agents may be added to provide a palatable oral preparation. These compositions may be preserved by the addition of an antioxidant such as ascorbic acid.
Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent, suspending agent and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, for example sweetening, flavoring and coloring agents, may also be present.
The pharmaceutical compositions of the invention may also be in the form of oil-in-water emulsions. The oily phase may be a vegetable oil, for example olive oil or arachis oils, or a mineral oil, for example liquid paraffin or mixtures of these. Suitable emulsifying agents may be naturally-occurring gums, for example gum acacia or gum tragacanth, naturally-occurring phosphatides, for example soy bean, lecithin, and esters or partial esters derived from fatty acids and hexitol anhydrides, for example sorbitan mono-oleate, and condensation products of the said partial esters with ethylene oxide, for example polyoxyethylene sorbitan monooleate. The emulsions may also contain sweetening and flavoring agents.
Syrups and elixirs may be formulated with sweetening agents, for example glycerol, propylene glycol, sorbitol or sucrose. Such formulations may also contain a demulcent, a preservative and flavoring and coloring agents. The pharmaceutical compositions may be in the form of a sterile injectable aqueous or oleagenous suspension. This suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example as a solution in 1,3-butane diol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of injectables.
Compound (I) may also be administered in the form of suppositories for rectal administration of the drug. These compositions can be prepared by mixing the drug with a suitable non-irritating excipient which is solid at ordinary temperatures but liquid at the rectal temperature and will therefore melt in the rectum to release the drug. Such materials are cocoa butter and polyethylene glycols.
For topical use, creams, ointments, jellies, solutions or suspensions, etc., containing the anti-inflammatory agents are employed.
Dosage levels of the order from about 1 mg to about 100 mg per kilogram of body weight per day are useful in the treatment of the above-indicated conditions (from about 50 mg to about 5 gms. per patient per day). For example, inflammation is effectively treated and anti-pyretic and analgesic activity manifested by the administration from about 25 to about 75 mg of the compound per kilogram of body weight per day (about 75 mg to about 3.75 gms per patient per day). Advantageously, from about 5 mg to about 50 mg per kilogram of body weight per daily dosage produces highly effective results (about 250 mg to about 2.5 gm per patient per day).
The amount of active ingredient that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. For example, a formulation intended for the oral administration of humans may contain from 5 mg to 5 gm of active agent compounded with an appropriate and convenient amount of carrier material which may vary from about 5 to about 95 percent of the total composition. Dosage unit forms will generally contain between from about 25 mg to about 500 mg of active ingredient.
It will be understood, however, that the specific dose level for any particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, rate of excretion, drug combination and the severity of the particular disease undergoing therapy.
D. Biological Data Supporting the Utility of the Compounds Within the Scope of the Invention
It has been found that the compounds of formula (I) exhibit in vitro and in vivo antagonistic activities with respect to the PAF.
A. In Vitro Assay
In vitro, they inhibit PAF-induced functions in both the cellular and tissue levels by disturbing the PAF binding to its specific receptor site. The ability of a compound of formula (I) to inhibit the PAF binding to its specific receptor binding site on rabbit platelet plasma membranes was measured by an assay recently developed by us.
The inhibition of H 3 -PAF binding to the rabbit platelet plasma membrane by a PAF-antagonist of Formula (I) was determined by a method employing isotropic labeling and filtration techniques. Generally, a series of Tris-buffered solutions of the selected antagonist at predetermined concentrations were prepared. Each of these solutions contains 1 pmole of 3 H-PAF, a known amount of the test antagonist, and a sufficient amount of the pH 7.5 Tris-buffer solution (10 mM Tris, 0.25% bovine serum albumin, and 150 mM NaCl per ml water) to make the final volume of 1 ml. After adding into a set of test tubes each with 100 μg of the platelet plasma membrane suspension (S. B. Hwang, et al., Biochemistry, 22, 4756 (1983)) and one of the Tris-buffer solutions described above, the resulting mixture in each test tube was incubated at 0° C. for about one hour or until the reaction was complete. Two control samples, one of which (C 1 ) contains all the ingredients described above except the antagonist and the other (C 2 ) contains C 1 plus a 1000-fold excess of unlabeled PAF, were also prepared and incubated simultaneously with the test samples. After the incubation was completed, the contents of each test tube were filtered under vacuo through a Whatman GF/C fiberglass filter and the residue washed rapidly several times with a total of 20 ml cold (0°-5° C.) Tris-buffer solution. Each washed residue was then suspended in 10 ml scintillation solution (Aquasol 2, New England Nuclear, Connecticut) and the radioactivity was counted in a Packard Tri-Carb 460CD Liquid Scintillation System. Defining the counts from a test sample as "Total binding with antagonist"; the counts from the control sample C 1 , as "Total binding C 1 "; and the counts from the control sample C 2 as "non-specific binding C 2 ", the percent inhibition of each test antagonist can be determined by the following equation: ##EQU1##
The following Tables I and II summarize the in vitro results:
TABLE 1______________________________________% Inhibition of PAF Binding byE (Trans)-1-(4-Substituted phenyl)methylene-5-R.sup.32-methyl-3-indenyl-R.sup.1. ##STR15## Dose %R.sup.1 R.sup.2 R.sup.3 μM Inhibitor______________________________________CH.sub.2 COOCH.sub.3 SO.sub.2 NH.sub.2 OCH.sub.3 5 100 1 84 0.5 70 0.1 35CH.sub.2 COOCH.sub.3 SO.sub.2 NHCH.sub.3 OCH.sub.3 5 100 0.5 67CH.sub.2 COOCH.sub.3 SOCH.sub.3 F 5 45CH.sub.2 COOCH.sub.3 SO.sub.2 NH.sub.2 F 1 60CH.sub.2 COOCH.sub.3 SO.sub.2 NHCH.sub.3 F 1 56CH.sub.2 CH.sub.2 OH SO.sub.2 NH.sub.2 OCH.sub.3 1 59CH.sub.2 COOCH.sub.3 3,4-dimethoxy OCH.sub.3 10 87 1 45CH.sub.2 COOH SO.sub.2 NH.sub.2 OCH.sub.3 5 4CH.sub.2 CH.sub.2 OCH.sub.3 SO.sub.2 NH.sub. 2 OCH.sub.3 5 100 2.5 100 1 80 0.5 76 0.25 58 0.1 40 0.05 20 0.1 2CH.sub.2 CH.sub.2 SOCH.sub.3 SO.sub.2 NH.sub.2 OCH.sub.3 5 74 0.5 24CH.sub.2 CH.sub.2 SCH.sub.3 SO.sub.2 NH.sub.2 OCH.sub.3 1 100 1 100 0.5 78 0.1 34CH.sub.2 CH.sub.2 SO.sub.2 CH.sub.3 SO.sub.2 NH.sub.2 OCH.sub.3 5 100 1 81 0.5 61 0.1 35CH.sub.2 CH.sub.2 SC.sub.6 H.sub.5 SO.sub.2 NH.sub.2 OCH.sub.3 5 56 ##STR16## SO.sub.2 NH.sub.2 OCH.sub.3 5 1 0.5 0.1 90 45 31 17CH.sub.2 CH.sub.2 OCH.sub.3 SO.sub.2 NH.sub.2 F 5 61______________________________________
TABLE II______________________________________% Inhibition of PAF Receptor byZ(Cis) 1-(4-Substituted-phenyl)methylene-5-R.sup.32-methyl-3-indenyl-R.sup.1 ##STR17## % In- Dose hib-R.sup.1 R.sup.2 R.sup.3 μM itor______________________________________CH.sub.2 CH.sub.2 NHCOCH.sub.3 SCH.sub.3 F 5 50CH.sub.2 CH.sub.2 NHCOCH.sub.3 SOCH.sub.3 F 5 39CH.sub.2 CH.sub.2 NHCOCH.sub.3 SO.sub.2 CH.sub.3 F 5 68 5 90CH.sub.2 COOH SO.sub.2 NH.sub.2 OCH.sub.3 50 94 20 57 5 32CH.sub.2 COOCH.sub.3 SONHC(NH)NH.sub.2 OCH.sub.3 1 50CH.sub.2 COOCH.sub.3 NHSO.sub.2CH.sub.3 OCH.sub.3 10 72 3 35CH.sub.2 COOH SOCH.sub.3 OC.sub.2 H.sub.5 5 42CH.sub.2 CH.sub.2 SC.sub.6 H.sub.5 SO.sub.2 NH.sub.2 OCH.sub.3 5 33CH.sub.2 COOCH.sub.3 SO.sub.2 NH.sub.2 OCH.sub.3 50 100 20 100 10 75 5 66 3 58 1 39CH.sub.2 CH.sub.2 OCH.sub.3 SO.sub.2 NH.sub.2 F 5 29 ##STR18## SO.sub.2 NH.sub.2 OCH.sub.3 5 68CH.sub.2 CH.sub.2 SOCH.sub.3 SO.sub.2 NH.sub.2 OCH.sub.3 5 56______________________________________
B. In Vivo Assay
The specific PAF-antagonistic activities are further established by in vivo assays following the protocol (modified procedure of Humphrey et al., Lab. Investigation, 46, 422 (1982)) described below:
______________________________________Protocol for the Evaluation of the Oral Activity ofPAF Antagonists or the Inhibition of PAF-InducedIncrease of Vasopermeability by PAF-Antagonists______________________________________I. Animal species: 5 guinea pigs (400-500 g)II. Material: 0.5% (w/v) aqueous methylcellulose solution sodium nembutol2% Evans Blue 2 g of Evans Blue in 100 ml ofsolution: pH 7.5 Tris-Buffer solutionTris-Buffer solution: 150 mM NaCl and 10 mM Tris/ml with pH adjusted to 7.5.III. Procedure(1.) Weigh the guinea pigs. Label them as control. T.sub.1, T.sub.2, T.sub.3 and T.sub.4. -(2.) Fast the animals overnight.(3.) Weigh the animals again after the fasting.(4.) Ground and suspend a PAF antagonist of formula (I) with intensive sonication in 3 ml of 0.5% aqueous methylcellulose solution.(5.) Administer orally to each of the animals T.sub.1, T.sub.2, T.sub.3 and T.sub.4 an appropriate amount (in terms of mg/kg of bodyweight) of the antagonist solution from 4), except the control animal which should receive only the 0.5% aq. methylcellulose solution.(6.) Forty minutes after the oral administration, anesthetize the animals with sodium nembutol (0.75 ml/kg i.p.).(7.) After 20 minutes or when the anesthetics became effective, inject intracardially to each animal 2 ml/kg body weight of the 2% Evans Blue solution.(8.) Wait for 10 minutes. In the meantime, shave the backs of the guinea pigs and get ready for the PAF injection. Select two rows of 5 (a total of ten) sites on the back of each animal and designate them as sites1a 2a 3a 4a 5a1b 2b 3b 4b 5band inject intracutaneously, in duplicate 0.1ml of a PAF solution in Tris-buffer or 0.1 mlof the Tris-buffer itself (control) accordingto the following schedule:Sites Solution to be injected1a Tris-buffer1b "2a 5 × 10.sup.-9 g/ml PAF2b "3a 5 × 10.sup.-8 g/ml PAF3b "4a 5 × 10.sup.-7 g/ml PAF4b "5a 5 × 10.sup.-6 g/ml PAF5b " Repeat the same injection on the backs of the remaining animals.(9.) Wait for 30 minutes or until the blue color developed into a steady shade on each injection site. Open the chest of each animal, extract by cardiac puncture 1 ml of blood and transfer it to a marked centrifuge tube. Centrifuge all the five blood samples at about 2000 xg for 10 minutes and decant the blue tinted supernatants (plasma). Set aside these plasma samples for later spectroscopic measurements.(10.) Sacrifice the animals and remove the back skin of each of them. Isolate with a 20 mm diameter steel punch the injection sites (blue spots) into individual discs of skin and dissect each of the skin discs into about 10-20 pieces.(11.) Mix in a 50 ml polyethylene test tube the skin pieces from a particular injection site with a medium containing 14 ml of acetone and 6 ml of 0.5% aqueous solution of sodium sulfate. See Harada, M., et al., J. Pharm. Pharmacol. 23, 218-219 (1971) for detailed procedures. Repeat the same procedures for each individual injection site.(12.) Homogenize the contents of each test tube on a polytron (Kinematica GmbH, Switzerland) with setting at 5 for 10-20 seconds.(13.) In the meantime, extract a 100 μl sample of each of the plasma set aside in Step (9) with the same acetone-aqueous sodium sulfate solution used in Step (11). Set aside the resulting extracts for late determination of the Evans blue concentration in the plasma of each animal.(14.) Centrifuge the skin preparations from Step (12) for 10 minutes at 750 xg and decant the supernatants for the following spectroscopic determination.(15.) Measure the absorbance of each supernatant from Step (14) ("skin sample") as well as the plasma extract from Step (13) ("plasma sample") at 620 nm with a Cary 210 spectrophotometer (Varian, Palo Alto, CA). Calculate the amount of Evans blue in each skin sample in terms of the volume (μl) of the exuded blood plasma according to the following equation: ##STR19## (II)(16.) Draw a plasma exudation curve for each animal, i.e., control, T.sub.1, T.sub.2, T.sub.3 and T.sub.4.(17.) Calculate the percent inhibition of PAF-induced cutaneous vascular permeability from measuring the area under the plasma exudation curve of the control animal (A.sub.C) and that of an animal treated orally with an antagonist (A.sub.D), for example T.sub.1, according to the following equation: ##STR20## = A.sub.C - A.sub.D /A.sub.C × 100 = (1 - A.sub.D /A.sub.C ) × 100 where the ratio A.sub.D /A.sub.C can be determined from the weight of the paper under the plasma exudation curve of the control curve (A) and that under the plasma exudation curve of the treated animal T.sub.1 (A.sub.D).______________________________________
The following table summarized the in vivo results.
TABLE III______________________________________% In Vivo Inhibition of PAF Receptor by E (Trans)-1-(4-Sub-stitutedphenyl)-methylene-5-R.sup.3-2-methyl-1H3-indenyl-R.sup.1 : ##STR21## DoseR.sup.1 R.sup.2 R.sup.3 mg/kg % Inhibitor______________________________________CH.sub.2 CH.sub.2 OCH.sub.3 SO.sub.2 NH.sub.2 OCH.sub.3 30 67 20 60 10 28CH.sub.2 CH.sub.2 SO.sub.2 CH.sub.3 SO.sub.2 NH.sub.2 OCH.sub.3 20 45 10 9CH.sub.2 CH.sub.2 SCH.sub.3 SO.sub.2 NH.sub.2 OCH.sub.3 20 46 10 30CH.sub.2 COOCH.sub.3 SO.sub.2 NH.sub.2 OCH.sub.3 50 0 ##STR22## SO.sub.2 NH.sub.2 OCH.sub.3 50 45 59 52______________________________________ | Indene derivatives have been found to have potent and specific PAF (Platelet-Activating-Factor) antagonistic activities and are thereby useful in the treatment of various diseases or disorders mediated by the PAF, for example, inflammation, cardiovascular disorder, asthma, lung edema, and adult respiratory distress syndrome. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is related to and claims the benefit of United Kingdom Patent Application No. 1419817.0, filed Nov. 7, 2014, which application is incorporated by reference herein for all purposes.
BACKGROUND
[0002] Aspects of the present disclosure are related to handling of data traffic in relation to a network controller-sideband interface (NC-SI). In a computer or other network connected device (e.g. switches, routers, and network controllers) a baseboard management controller (“BMC”) is a service processor or a microcontroller usually embedded on the motherboard of a server. The microcontroller uses sensors to report on matters such as temperature and fan speeds. The microcontroller may also control the operation of the system, including matters such as firmware updates, hardware configuration, power management, and monitoring. BMCs deployed in large network systems must be remotely accessible over the network, in particular via the network interface controller (“NC”) of the managed device, or via a serial port connected to the microcontroller. An Intelligent Platform Management Interface (“IPMI”) can specify a set of interfaces, protocols, and hardware buses for building such remote managed systems.
[0003] In such a network environment, the interface between the BMC and the NC can be referred to as the Network Controller-Sideband Interface (NC-SI). The NC-SI is a standardized interface that enables an NC to provide network access for a BMC, while allowing the NC to simultaneously and transparently provide network access for a host system. An NC-SI specification can define protocols and electrical specifications for a common Sideband Interface (SI) between a BMC and an 802.3 Local Area Network (LAN) via one or more external NCs. The NC-SI specification version 1.0.0 was published in July 2009 by the PMCI Working Group of the Distributed Management Task Force (DMTF).
SUMMARY
[0004] According to embodiments of the present disclosure, the present disclosure is directed towards a network interface controller that could provide a connection for a device to a network. In embodiments, the network interface controller can include a sideband port controller. In embodiments, the sideband port controller can provide a sideband connection between the network and a sideband endpoint circuit that can be operative to communicate with the network via a sideband. In embodiments, the sideband port controller can include an event notification unit operative to compile information into an event notification packet. In embodiments, the sideband port controller can further include a packet parser. In embodiments, the packet parser could be operative to analyses a packet to provide an indication that the packet contains the event notification packet. In embodiments, the sideband port controller could be operative to forward the information in the event notification packet to the sideband endpoint circuit, responsive to that indication.
[0005] According to embodiments of the present disclosure, the present disclosure is directed towards a method that could include providing event notifications in a network interface controller that could provide a connection for a device to a network. In embodiments, the network interface controller can include a sideband port controller. In embodiments, the sideband port controller could provide a sideband connection between the network and a sideband endpoint that could be operative to communicate information with the network via a sideband. In embodiments, the method can include compiling information into an event notification packet. In embodiments, the method can include analyzing a packet to provide an indication that the packet contains the event notification packet. In embodiments, the method can further include forwarding, responsive to the indication that the packet contains the event notification packet, the information in the event notification packet to the sideband endpoint.
[0006] The above summary is not intended to describe each illustrated embodiment or every implementation of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 illustrates a diagram of a device showing an example main network controller-sideband interface (NC-SI) connection.
[0008] FIG. 2 illustrates a diagram of NC-SI connections, according to embodiments of the present disclosure.
[0009] FIG. 3 illustrates a diagram of an asynchronous event notifications (AEN) unit, according to embodiments of the present disclosure.
[0010] FIG. 4 illustrates a diagram of a circuit around a transmit arbiter, according to embodiments of the present disclosure.
[0011] FIG. 5 illustrates a diagram of circuits for injecting pass-through traffic in the host traffic, according to embodiments of the present disclosure.
[0012] FIG. 6 illustrates a diagram of circuits for extracting pass-through traffic from the host traffic, according to embodiments of the present disclosure.
[0013] FIG. 7 illustrates a diagram of a structure of an AEN NC-SI packet, according to embodiments of the present disclosure.
DETAILED DESCRIPTION
[0014] A Network Controller-Sideband Interface (NC-SI) port controller (NPC) is a circuit that can provide a connection between a baseboard management controller (BMC) and a network interface controller (NC) for local and remote management traffic. It can allow two types of traffic to be carried between the BMC and the NC: “Control” traffic and “Pass-through” traffic. Control traffic consists of commands (requests) sent to the local NC for controlling and configuring it, responses sent by the NC back to the BMC, as well as Asynchronous Event Notifications (“AENs”) in which the NC can send data back to the BMC without being prompted from the BMC. Pass-through traffic consists of packets that are transferred between an external network and the local BMC using the NC-SI. An NPC is not limited to communicating the sideband data with a BMC, but that is the usual endpoint for it.
[0015] FIG. 1 shows an example of a device 1 that can communicate with a network 2 . The network 2 can handle the reception of packets into the device. The device 1 can include a host Ethernet adapter (HEA) 3 . The device 1 can include an associated media access controller (MAC) 4 . The MAC 4 can receive data from the network 2 via its communication line and can transmit the data to a line buffer 5 (via a switch 12 ). This buffer forms part of a receive backbone (RBB) 6 . The RBB manages the movement of data from the MAC by converting, aligning, and storing the data into the line buffer 5 . Once the RBB 6 stores the data, the RBB 6 transmits the data to a second buffer 7 . The second buffer 7 forms part of a (BaRT-based finite state machine (BFSM))-based parser filter and checksum (BPFC) 8 . The second buffer 7 is known in this case as the “data path”.
[0016] The role of BPFC 8 is to analyze the packets in the second buffer 7 and make various decisions, for example, checking a checksum of a data packet that can be transmitted with the data packet. A various decision can also be to decide a packet queues to send the data packet to (the packet queues are not shown), i.e. those for distributing packets to other ports of the switch, classifying or discarding the packets, before they are forwarded to the main part of the device, i.e. the host. This can be accomplished with a packet parser 9 like that known from US2012/0159132 and US2012/0195208.
[0000] The packet parser 9 can include a rule processor 10 that can receive data from the data path buffer 7 and can then apply parsing rules to the received data. The parsing rules can include a test part and a result part. The test part can specify, among other things, values to compare with the received data and masks that can be applied to match a current rule. The result part can encode, among other things, a set of instructions and actions to be performed when the current rule is matched. This combination of comparisons and actions can be used to make the various decisions noted above. The rules can be loaded from a local store (and several are loaded into the rule processor 10 to be processed in parallel). The packet parser 9 can be arranged to scan through the packet for an end of packet marker once it has been indicated that the packet is to be passed to the network.
[0017] Transmit backbone unit (XBB) unit 16 can receive the packets from a host and can prepare them for transmission by the MAC 4 (via the switch 12 ). The MAC 4 can also pass traffic between the network 2 and a BMC 17 . This traffic is known as pass-through traffic because it does not carry a local NC command or NC response. Pass-through packets from the BMC 17 to be transmitted over the network 2 can be received by an NPC unit 23 and can be passed from the NPC unit 23 to MAC 4 (via the switch 12 ), and packets received by the MAC 4 destined for the BMC can be handled by the NPC unit before being passed to the BMC. In FIG. 1 (and FIG. 2 discussed below) the NC can include the HEA 3 , MAC 4 , switch 12 , and NC-SI port controller (NPC) 23 , but may not include the BMC 17 . The switch 12 is provided to route the packets between the MAC 4 , the HEA 3 and the NPC 23 .
[0018] FIG. 2 shows an embodiment of a device 1 . This embodiment, in block diagram form, shows the internal circuit of the NC-SI port controller (NPC) 23 described in FIG. 1 . NPC 23 can include a MAC 26 , a first transmit buffer 25 , an Asynchronous Event Notification Unit (AEN unit) 28 , an NC-SI packet handler 29 , a receive buffer 24 , a transmit arbiter 21 , and a receive arbiter 22 . The MAC 26 is connected to receive packets from the BMC 17 and can operate to pass the received packets into the first transmit buffer 25 . The packets can be passed from there, via the transmit arbiter 21 to a second transmit buffer 27 . When the packets are at the second buffer 27 , the NC-SI packet handler 29 can examine them and can determine whether they should be forwarded to the XBB unit 16 (from where they can be forwarded to network 2 via MAC 4 ), or whether they should remain within the NPC 23 for further processing. The data sent to the NPC 23 by the BMC 17 can include commands for the NC such as, for example, enable/disable a channel or get parameters, as well as pass-through packets to be forwarded by the NIC on to the external network 2 . The NC-SI packet controller 23 can provide a transmit data route between an input at NPC MAC 26 and the output of the second transmit FIFO 27 , which route can include NPC MAC 26 , first transmit buffer 25 transmit arbiter 21 , and second transmit buffer 27 . Buffers that are include in the embodiments of the present disclosure can include a first in, first out (FIFO) method. The FIFO method can organize and manipulate a data buffer, where an oldest (first) entry, or ‘head’ of the queue, is processed first. A Wr request 286 is depicted.
[0019] Ethernet packets received into the NC-SI port controller 23 from the network via RBB unit 6 can be passed directly to the receive buffer 24 . The receive arbiter 22 can choose between the NC-SI packet handler 29 and the receive buffer 24 for which packet to transmit next to the BMC 17 . This can be accomplished by connecting the receive buffer 24 or the NC-SI packet handler 29 to the NPC MAC 26 , which in turn can transmit it to the BMC. The NPC 23 can provide a receive data route between an input to receive buffer 24 and an output at NPC MAC 26 , which route also can include those and the transmit arbiter 22 . The receive buffer 24 , can include an overrun mechanism that can drop incoming packets when it is full.
[0020] In some embodiments, the receive arbiter 22 can connect the NC-SI packet handler 29 to the MAC 26 , thereby transmitting data from the NC-SI packet handler to the BMC. This data may be responsive to commands from the BMC, but may also be Asynchronous Event Notifications (AENs). In some other embodiments, the NPC can be in connection to a NC, the NC can include more than one external network connection. One of such connections is then referred to as a “channel”, and one receive buffer (such as 24 ) can be provided per channel into the NPC. Asynchronous Event Notification packets (AENs) can enable the NC to deliver unsolicited notifications to the BMC when certain status changes occur in the NC. Each event consists of a specific AEN packet that the NPC can generate and then send to the BMC, the AEN packet discussed further in FIG. 7 .
[0021] In embodiments, an AEN packet can include a certain structure. FIG. 7 depicts the packet format of a NC-SI AEN packet. The AEN packet comprises a plurality of ordered fields, where each field can have characteristics, such as size, length, position in a packet, content, possible values, etc. in accordance with an NC-SI specification. The different fields can be indicated using labels that indicate their function and/or content. A summary of the labelled fields and their associated function and/or content is as follows:
[0022] “DA” represents the Destination Address field of the Ethernet header that can encapsulate NC-SI packets. This field may not interpreted by the BMC and is always set to a broadcast address in a form of FF:FF:FF:FF:FF:FF:FF.
[0023] “SA” represents the Source Address field of the Ethernet header which encapsulates all NC-SI-packets. The NC always sets this field to FF:FF:FF:FF:FF:FF for the NC-SI packets that it can generate.
[0024] “EtherType” represents the EtherType field of the Ethernet header which encapsulates all NC-SI packets. This field can be set to the value of 0x88F8.
[0025] “MCID” identifies the BMC which has issued the command. This field is fixed to the value of 0x00 in version 1.0.0 of the NC-SI specification.
[0026] “HR” identifies the version of the control packet header used by the sender. The value of 0x01 corresponds to version 1.0.0 of the NC-SI specification.
[0027] “IID” is a sequence number copied from the sequence identifier field used by the corresponding command sent by the BMC. This field is fixed to 0x00 because by definition, an AEN packet is never issued as a response to a previous BMC command and therefore an AEN packet does not need to be acknowledged with an IID sequence number.
[0028] “CPT” is a Control Packet Type field that identifies the current packet among 127 possible type of commands and 127 possible type of responses. Because an AEN packet is neither a command nor a response, this field is fixed to 0xFF.
[0029] “ChID” identifies the package ID and the internal channel ID of the NC which is issuing this AEN.
[0030] PLLen contains the length of the payload data present in the current AEN packet, excluding Payload Pad and optional Checksum value.
[0031] “AEN-TYPE” can identify the type of AEN packet. Currently, only three AEN types are defined by the NC-SI specification version 1.0.0. These are the Link Status Change type (encoded with AEN-TYPE=0x0), the Configuration Required type (encoded with AEN-TYPE=0x1) and the Host NC Driver Status Change type (encoded with AEN-TYPE=0x2). AEN-TYPE values 0x3 . . . 0x7F are reserved and AEN-TYPE values 0x80 . . . 0xFF are for OEM-specific use.
[0032] “Payload Data” contains AEN packet-specific data.
[0033] “Payload Pad” are 0 to 3 Bytes used to align the Checksum field to a 32-bit boundary and make the overall Payload (Data+Pad) multiple of 4 Bytes. These padding bytes are always equal to 0x00.
[0034] “Checksum” is the 32-bit checksum compensation value computed as the 2's complement of the checksum over the 16-bit unsigned integer values that make up the AEN packet. The content of this field is optional and a value of all zeros can be set to specify that the checksum is not being provided for the current response.
[0035] “FCS” represents the Frame Check Sequence field of the Ethernet header which encapsulates all NC-SI packets.
[0036] As mentioned above, it is one of the tasks of the NPC 23 to generate and send such formatted AEN packets to the BMC. This it does when the NC-SI packet handler 29 is exposed to asynchronous events from the NC.
[0037] The NC-SI packet handler 29 is exposed to asynchronous events when an AEN pseudo-packet ends up into the transmit buffer 27 and its content is parsed.
[0038] AEN pseudo-packets are compiled by the AEN unit 28 . The details of this unit are shown in FIG. 3 , according to various embodiments. When enabled by an enable signal 281 , this compiles an AEN pseudo-packet of up to 16 bytes (=128 bits) in a latch 282 . In embodiments, the AEN pseudo-packet can contain four 1-bit flags so as to implement three AEN packet types that can be defined by the NC-SI specification version 1.0.0 (the rest of the bits can be unused). A larger AEN pseudo-packet can allow for it to be used by other circuits that have much more complex states to report than as NIC can have. Bit 0 of the AEN pseudo-packet is connected to be set if any of three signals from the HEA 3 that indicate that the status of the “external interface link”, i.e. the connection to the network provided by the conductors or fiber optic connected to the MAC 4 , has changed, which signals are grouped together by an OR gate 283 . In embodiments, bit 1 of the AEN pseudo-packet is set if the network controller has transitioned to an error or a reset state which requires the interface to be re-initialized by the BMC. Bit 2 of the AEN pseudo-packet is set if there is a change in the state of the host driver of the NC. Bit 3 of AEN pseudo-packet corresponds to the payload field of an AEN packet of AEN-TYPE=2. This bit indicates whether NC driver for the host external network interface is operational (‘1’) or not (‘0’), and is provided by a memory mapped IO (MMIO) register 284 which is accessible by the host. Finally the AEN unit 28 provides a valid signal being the logical AND, provided by AND gate 285 , of the enable signal 281 and the logical OR, provided by OR gate 287 , of the three AEN status signals from the HEA. So this signal indicates that there is some AEN status to report. Compiling can include at least part of the content of the memory mapped register 284 as at least part of the event notification packet. The compiling may be responsive to a memory mapped register 284 and can be done in response to writing of the memory mapped register 284 .
[0039] FIG. 4 shows a first part of how the AEN pseudo-packet can be delivered to NC-SI packet handler 29 shown in FIG. 2 , according to various embodiments. This can show the route of the AEN pseudo-packet from the AEN unit 28 to the second transmit buffer 27 . This can include the latch 282 , a multiplexer 212 of the transmit arbiter 21 , and the marked connection to the second transmit buffer 27 . Arbitration logic 211 of transmit arbiter 21 receives the valid signal from AEN unit 28 and a signal 251 from the first transmit buffer 25 indicating its status and decides which should pass its packet to the second transmit buffer 27 . It can then accordingly set multiplexer 212 of the transmit arbiter 21 to connect the second transmit buffer 27 to the first transmit buffer 25 or pseudo-packet latch 282 . The data in the connected one of those is then passed to the second transmit buffer 27 . The transmit arbiter 21 gives priority to the pseudo-packet latch 282 because its transmission is somehow equivalent to the generation of a software interrupt in the context of a general purpose processor.
[0040] FIG. 2 shows the second part of how the AEN pseudo-packet is delivered to the BMC 17 . The NC-SI packet handler 29 can read data from the AEN pseudo-packet in the second transmit buffer using a sliding window, i.e. a parallel set of connections to a portion of the data, the portion being determined by a pointer. The NC-SI packet handler 29 has a packet parser 30 . This has similar structure and operation to that of the BPFC unit 8 in that it has rules coded in wide instruction words which can specify, among other things, values for comparing with the data words and masks to be applied in the comparison, which comparisons are used to identify conditions and make decisions, providing output accordingly. The rules in this case are rules for carrying out the functions of the NC-SI packet handler 29 . AEN pseudo-packets are tagged with a control bit allowing the packet parser 30 to differentiate them from other NC-SI command packets and pass-through packets. The NC-SI packet handler 29 has a set 31 of action machines 32 which respond to the output of the packet parser 30 by taking various actions. In the case of the packet parser 30 identifying an AEN pseudo-packet, an AEN/RSP action machine 32 prepares one (and possibly multiple) AEN packet formatted according to the structure depicted in FIG. 7 . When the AEN packet is ready for forwarding to the BMC 17 , it can be presented to receive arbitrator 22 , which decides when it should be passed to MAC 26 , which can transmit it to the BMC 17 .
[0041] When the packet parser 30 recognizes an NC-SI command packet in the second transmit buffer 27 it can apply a set of rules to it to decode the command and provides output to the AEN/RSP action machine 32 causing it to generate a NC-SI response packet containing the information sought by the command. Again, the AEN/RSP action machine 32 can format and presents the response packet to receive arbitrator 22 , which can decide when it should be passed to MAC 26 , which can transmit it to the BMC 17 .
[0042] The receive arbitrator 22 can give priority to command responses and AEN packets to avoid the BMC becoming starved of those in the case of a long burst of pass-through packets for the BMC is received from the network.
[0043] Finally, the packets in the second transmit buffer 27 may be pass-through packets from the BMC bound for the network. These packets are recognized by the parser if they carry an EtherType value that is different from the NC-SI EtherType (i.e. 0x88F8), and if their source MAC address matches the settings of the external network interface. Once identified by the packet parser 30 of the NC-SI packet handler 29 , the output of the sliding window can be passed to the XBB unit 16 . The packet parser can advance the sliding window along the pass-through packet transmitting the packet data to the XBB unit 16 as it goes, terminating when a rule of the packet parser 30 finds an end of packet (EOP). No other rule processing is done by the packet parser 29 , since the NC-SI is not concerned with the content of the packet.
[0044] The first and second transmit buffers 25 , 27 can be provided with a pause mechanism, which can allow flow control of packets from the BMC 17 . So, for example if the route from the BMC 17 to the network 2 becomes blocked by AEN pseudo-packets or packets from the HEA to the XBB unit 16 , the BMC pauses sending its packets. This can be discussed further below.
[0045] FIG. 5 is a block diagram of the relevant components in the XBB unit 16 and the NPC 23 for the injection of data packets from the BMC 17 into the XBB unit 16 and hence into the stream of packets transmitted by the main MAC 4 , according to various embodiments. Note that in FIG. 5 and FIG. 6 the dashed connections show the path of the data packets.
[0046] Firstly, when a data packet has been forwarded to the second buffer 27 of the NPC unit 23 , as noted above, the packet parser 30 can read the packet then determine if the packet is an NC-SI command, AEN pseudo-packet or pass-through packet from the BMC 17 that is to be injected into the XBB unit 16 .
[0047] If the data packet is an NC-SI command then the packet parser 30 examines the packet and signals ejection logic 410 to gate a back-pressure signal that it receives from the XBB unit 16 , allowing the packet to be discarded from the second buffer 27 after being processed and without entering the XBB unit 16 . The back pressure signal, is a full signal from the XBB unit and indicates that it cannot receive further packets.
[0048] If the packet is a pass-through packet then the packet parser 30 does not gate the back pressure. The packet parser having analysed the packet, its outputs cause the action machine 31 to switch on an inject signal for the XBB unit 16 .
[0049] If a packet injection register (PR) 500 of the XBB unit 16 is not full (signalled by the back pressure/full signal from a latch 501 ), then the data packet is transferred from the buffer 27 to the PIR 500 . This is apart from the part of the data packet containing the MAC status, which is not used in the XBB unit 16 and is discarded. The end of packet marker (EOP) triggers the latch 501 to be set, which indicates the PIR 500 is full.
[0050] Next, a packet injection arbiter (PIA) 512 of the XBB unit selects the next packet to be forwarded to an output XS1 buffer 508 of the XBB unit 16 . This arbitration occurs when a packet is not engaged. Priority is given to an XS2 buffer 506 , which receives normal data packets from the host into the RBB unit, but a “leak” mechanism is provided by the arbiter 512 so the network is not starved of pass-through traffic from the NPC unit 23 . In the “leak” mechanism a counter is provided connected to increment when an in-band packet is advanced from XS1 to XS2 and to be reset when a packet is advanced from the NPC, and the arbiter 512 is arranged to allow a packet from the NPC packet to advance when the counter has reached a certain value. If the XS2 buffer 506 is empty, which indicated to the PIA 512 by that buffer's “empty” signal, then the PIR 500 is selected, and vice versa. Once the decision has been made, a packet engaged latch (PEL) 504 is set.
[0051] The data packet then transfers from the selected source (either the XS2 buffer 506 or the PR 500 ) to an XS1 buffer 508 of the RBB unit 16 . If the XS1 buffer 508 is full then a “full” signal from that buffer is sent to a transfer logic block 507 , which gates the back pressure for this transfer (i.e. stops data packets being transferred from either the XS2 buffer 506 or the PIR 500 ). An end of packet (EOP) signal can be sent to the PIA 512 when the end of packet marker is transferred to the XS1 buffer 508 , which resets the packet engaged latch (PEL) 504 , and the arbitration decision process in the PIA 512 begins again.
[0052] The XS1 buffer 508 then transmits the received data packets to the main MAC 4 . Note that injection of sideband packets at this point in the transmission of host data to the network also allows sideband packets to be looped-back to the receive path (i.e. via the RBB unit 3 and BFPC unit 8 ) to the host. This allows implementation of “OS2BMC” technology.
[0053] In FIG. 6 , a block diagram of the relevant components in the RBB unit 6 and the NPC unit 23 for extracting data packets from the main traffic incoming to the device from the network that are destined for the BMC 17 can be seen, according to various embodiments. Write 31 and 24 are within the NPC as indicated by a dotted vertical line that is to the left of 31 .
[0054] Firstly, data can be received by buffer RS 1 X 600 a and buffer RS 2 X 600 b of the RBB unit from the main MAC 4 then into MUX 502 . A scheduler 604 can then decide which of those buffers the next data packet is selected from via an arbitration mechanism.
[0055] The selected data packet is read by a decoder 608 . The decoder 608 reads the packet header. If the packet header says that the packet is destined for the BMC 17 then the decoder 608 sets a latch 606 . If the packet header is not destined for the BMC 17 then the decoder does not set the latch 606 .
[0056] The write control scheduler 604 then sends a “write” pulse. If the latch 506 is set, then the “write” pulse is sent to the action machines 31 in the NC-SI unit 23 and the packet can be sent to the receive buffer 24 of the NC-SI. If the latch is not set, the “write” pulse can be sent to a FIFO control 510 of the RBB unit and the packet can be sent to a line buffer (LB) 512 of the RBB unit.
[0057] Finally, the EOP marker of the packet triggers the latch 606 to reset, making the LB buffer the default recipient of incoming packets. In turn packets in the LB buffer 512 can be passed to the BPFC unit 8 .
[0058] Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein.
[0059] The present invention may be a system or a method.
[0060] The block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems and methods according to various embodiments of the present invention. In this regard, each block in the block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams, and combinations of blocks in the block diagrams can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions. | Aspects of the present disclosure are directed towards a network interface controller that could provide a connection for a device to a network. The network interface controller can include a sideband port controller. The sideband port controller can provide a sideband connection between the network and a sideband endpoint circuit that can be operative to communicate with the network via a sideband. The sideband port controller can include an event notification unit operative to compile information into an event notification packet. The sideband port controller can further include a packet parser. In embodiments, the packet parser could be operative to analyses a packet to provide an indication that the packet contains the event notification packet. In embodiments, the sideband port controller could be operative to forward the information in the event notification packet to the sideband endpoint circuit, responsive to that indication. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a magnetic bearing device and, more particularly, to a magnetic bearing device in which the need for detection of and control of the position of a rotational member in the axial direction is eliminated to reduce the number of component parts, and which, therefore, can be smaller in size and can have lower manufacturing cost and lower power consumption.
2. Description of the Related Art
FIG. 5 illustrates an example of a conventional magnetic bearing device 10 of a five axes control type. An upper radial electromagnet 1 in the arrangement shown in FIG. 5 is capable of adjusting the position in the radial direction (hereinafter referred to simply as “radial position”) of an upper portion of an inner rotor 3 with an adjustment meter or the like (not shown) based on a radial position detected by an upper radial position detection sensor 2 . On the other hand, a lower radial electromagnet 5 is capable of adjusting the radial position of a lower portion of the inner rotor 3 with an adjustment meter or the like (not shown) based on a radial position detected by a lower radial position detection sensor 6 .
A motor 7 is provided between the upper radial electromagnet 1 and the lower radial electromagnet 5 to cause the inner rotor 3 to rotate at a high speed in a state of floating by magnetic force. A disk 9 is fixed to a portion of the inner rotor 3 below the lower radial position detection sensor 6 . The disk 9 is attracted upward by an upper axial electromagnet 11 a and is attracted downward by a lower axial electromagnet 11 b.
An axial sensor 13 is provided in a lower portion of a cylindrical casing 15 so as to face the lower end of the inner rotor 3 . The position in the axial direction (hereinafter referred to simply as “axial position”) of the inner rotor 3 can be adjusted by balancing the attractions of the upper and lower axial electromagnets 11 a and 11 b with an adjustment meter or the like on the basis of the axial position detected by the axial sensor 13 .
In the above-described conventional magnetic bearing device 10 , however, the axial sensor 13 , the upper axial electromagnet 11 a and the lower axial electromagnet 11 b are required for supporting the rotor at the predetermined axial position.
The number of component parts of the magnetic bearing device 10 is thereby increased, so that it is difficult to reduce the manufacturing cost and size of the magnetic bearing device. Moreover, since electric power is consumed by the upper and lower axial electromagnets 11 a and 11 b , there is a limit to reduction of the power consumption.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above-described problems of the conventional art, an object of the present invention is to provide a magnetic bearing device in which the need for detection of and control of the position of a rotating member in the axial direction is eliminated to reduce the number of component parts, and which, therefore, can be smaller in size and can have lower manufacturing cost and lower power consumption.
To achieve the above-described object, according to the present invention, there is provided a magnetic bearing device comprising: a rotational member floated and supported by magnetic force; at least one permanent magnet arranged on the rotational member; magnetic means for rotating the rotational member by magnetic fields generated through a core on which motor coils are formed, and which is spaced apart from the permanent magnet in the radial direction so as to form a predetermined gap therebetween; at least one set of radial position detection means for detecting the radial position and/or the inclination of the rotational member; and at least one set of radial position adjustment means for adjusting the radial position and/or the inclination of the rotational member based on the radial position and/or the inclination of detected by the radial position detection means. According to the present invention, the rotational member is supported at the desired axial position by axial direction components of magnetic attractions generated between the permanent magnet and the core.
The rotational member rotates in a state of floating by magnetic force. The rotational member comprises an inner rotor and an outer rotor. The magnetic bearing device is assumed to comprise an electric motor and a generator capable of floating a rotational member by magnetic force. The rotational member is provided with at least one permanent magnet. The core on which the motor coils constituting the magnetic means are formed is spaced apart from the permanent magnet so as to form a predetermined gap therebetween. The rotational member is rotated by magnetic attraction forces generated between the permanent magnet and the magnetic means.
The radial position detection means detects the radial position and/or the inclination of the rotational member. The radial position adjustment means adjusts the radial position and/or the inclination of the rotational member based on the radial position and/or the inclination detected by the radial position detection means.
In the case of three axes control, a radial position control is formed by one set of radial position detection means and one set of radial position adjustment means. In the case of five axes control, a radial position control is formed by two sets of radial position detection means respectively provided in two places distanced apart from each other along the axial direction, and two sets of radial position adjustment means also provided in two places along the axial direction.
There is no particular limitation in the order in which the radial position detection means and the radial position adjustment means are arranged in the axial direction.
The rotational member is supported at the desired axial position by axial direction components of magnetic attractions generated between the permanent magnet and the core.
As described above, the need for detection of and control of the position of the rotational member in the axial direction can be eliminated. Accordingly, the number of component parts can be reduced, and the magnetic bearing device can be small in size and can have low manufacturing cost and low power consumption.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a longitudinal sectional view of a magnetic bearing device which represents an embodiment of the present invention;
FIG. 2 is a cross-sectional view taken along the lines I—I and V—V of FIG. 1;
FIG. 3 is a cross-sectional view taken along the line III—III of FIG. 1;
FIG. 4 is a cross-sectional view taken along the lines II—II and IV—IV of FIG. 1; and
FIG. 5 is a diagram showing an example of a conventional magnetic bearing device of a five axes control type.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the present invention will be described below with reference to FIGS. 1 through 4, in which components identical or corresponding to those shown in FIG. 5 are indicated by the same reference symbols. The description for the corresponding components will not be repeated.
Referring to FIG. 1, an upper radial position detection sensor 2 , an upper radial electromagnet 1 , a motor 7 , a lower radial electromagnet 5 and a lower radial position detection sensor 6 are mounted in this order on the circumferential surface of a stator 21 from an uppermost position to a lowermost position thereon. A rotational member comprises a shaft 23 which is passed through a central portion of the stator 21 . A stopper 24 is fixed to the lower end of the shaft 23 , while an outer rotor 25 of the rotational member is fixed to the upper end of the shaft 23 . The stopper 24 prevents the rotating member from coming off the stator 21 .
The outer rotor 25 is a rotational member having a hollow cylindrical shape such as to cover the upper radial position detection sensor 2 , the upper radial electromagnet 1 , the motor 7 , the lower radial electromagnet 5 , and the lower radial position detection sensor 6 .
The upper radial position detection sensor 2 (having the same construction as the lower radial position detection sensor 6 ) is formed by winding radial position detection coils 2 c around projecting portions 2 b extending from an iron core 2 a , as shown in FIG. 2 . The projecting portions 2 b and the radial position detection coils 2 c are formed in four circularly-distributed places such as to form magnetic pole pairs in X- and Y-directions.
That is, the projecting portions 2 bx 1 and the radial position detection coils 2 cx 1 are provided in the X-axis plus direction; the projecting portions 2 bx 2 and the radial position detection coils 2 cx 2 , in the X-axis minus direction; the projecting portions 2 by 1 and the radial position detection coils 2 cy 1 , in the Y-axis plus direction; and the projecting portions 2 by 2 and the radial position detection coils 2 cy 2 , in the Y-axis minus direction.
Also, the upper radial electromagnet 1 (having the same construction as the lower radial electromagnet 5 ) is formed by winding radial position adjustment coils 1 c around projecting portions 1 b extending from an iron core 1 a , as shown in FIG. 4 . The projecting portions 1 b and the radial position adjustment coils 1 c are formed in four circularly-distributed places such as to form magnetic pole pairs in X- and Y-directions, respectively.
That is, the projecting portions 1 bx 1 and the radial position adjustment coils 1 cx 1 are provided in the X-axis plus direction; the projecting portions 1 bx 2 and the radial position adjustment coils 1 cx 2 , in the X-axis minus direction; the projecting portions 1 by 1 and the radial position adjustment coils 1 cy 1 , in the Y-axis plus direction; and the projecting portions 1 by 2 and the radial position adjustment coils 1 cy 2 , in the Y-axis minus direction.
The radial position detecting coils 2 c of the upper radial position detection sensor 2 , and the radial position adjustment coils 1 c of the upper radial electromagnet 1 are provided in the same directions.
The motor 7 is formed by winding motor coils 7 c around projecting portions 7 b extending from an iron core 7 a , as shown in FIG. 3 . The core of the motor 7 is formed by the iron core 7 a and the projecting portions 7 b . The projecting portions 7 b and the motor coils 7 c are formed in twelve places circularly arranged at regular intervals.
On the inner surface of the outer rotor 25 , an upper radial position detection target 32 is fixed circularly while being positioned so as to face the projecting portions 2 b of the upper radial position detection sensor 2 . Similarly, a lower radial position detection target 36 , an upper radial position adjustment target 31 , and a lower radial position adjustment target 35 are fixed on the inner surface of the rotor 25 while being positioned so as to face projecting portions 6 b of the lower radial position detection sensor 6 , the projecting portions 1 b of the upper radial electromagnet 1 , and projecting portions 5 b of the lower radial electromagnet 5 , respectively.
Each of the upper radial position detection target 32 , the lower radial position detection target 36 , the upper radial position adjustment target 31 , and the lower radial position adjustment target 35 is formed a laminated piece of steel.
A motor permanent magnet 37 is fixed on the inner surface of the rotor 25 while being positioned so as to face the projecting portions 7 b of the motor 7 . The motor permanent magnet 37 is magnetized so as to have a predetermined number of magnetic poles.
The operation of the embodiment of the present invention will now be described.
An X-direction displacement of an upper portion of the outer rotor 25 is detected with the radial position detection coils 2 cx 1 and 2 cx 2 , and an X-direction displacement of a lower portion of the outer rotor 25 is detected with the radial position detection coils 6 cx 1 and 6 cx 2 . This detection is performed based on a change in the inductance between each sensor and the outer rotor 25 .
Also, a Y-direction displacement of the upper portion of the outer rotor 25 is detected with the radial position detection coils 2 cy 1 and 2 cy 2 , and a Y-direction displacement of the lower portion of the outer rotor 25 is detected with the radial position detection coils 6 cy 1 and 6 cy 2 .
The radial position adjustment coils 1 cx 1 and 1 cx 2 are excited through an adjustment meter or the like (not shown) on the basis of the detected X-direction displacements, while the radial position adjustment coils 1 cy 1 and 1 cy 2 are excited through an adjustment meter or the like (not shown) on the basis of the detected Y-direction displacements. The excited coils attract the outer rotor 25 to adjust the radial position of the upper portion of the outer rotor 25 . The radial position adjustment of the lower portion of the outer rotor 25 is also performed in the same manner.
The motor permanent magnet 37 and the motor coils 7 c drive and rotate the outer rotor 25 by the magnetic attractions generated between them, and also support the outer rotor 25 in the predetermined position in the axial direction by their magnetic attractions. This support is also effected when the outer rotor 25 is in a stationary state.
In the above-described arrangement, there is no need for additional means for supporting the axial position of the outer rotor 25 at the predetermined position, such as required for the conventional magnetic bearing device shown in FIG. 5, i.e., the axial sensor 13 , the upper axial electromagnet 11 a , the lower axial electromagnet 11 b , and the targets facing these components.
Therefore, the manufacturing cost and the size of the magnetic bearing device 20 can be reduced by reducing the number of component parts, as described above. Further, since the axial sensor 13 , the upper axial electromagnet 11 a and the lower axial electromagnet 11 b which are required for the conventional magnetic bearing device shown in FIG. 5 are not necessary in the magnetic bearing device of the present invention, electric power can be correspondingly saved.
In the bearingless motor, the magnetic forces generated by the motor coils 7 c are unbalanced by the magnetic forces generated by the radial position adjustment coils 1 c or the radial position adjustment coils 5 c to magnetically adjust the radial position while producing a rotating force.
The present invention can also be applied to a magnetic bearing device using an integral bearingless motor constructed in such a manner that the motor coils 7 c and radial position adjustment coils 1 c or the radial position adjustment coils 5 c are formed on one iron core. Also in such a case, the axial sensor 13 and other components can be eliminated.
According to the present invention, as described above, the rotational member is supported at the desired axial position by axial direction components of magnetic attractions generated between the permanent magnet and the magnetic thereby eliminating the need for detection of and control of the position of the rotational member in the axial direction. Consequently, the number of component parts can be reduced. | A magnetic bearing device has a rotational member mounted for undergoing rotation about a rotary axis, a permanent magnet disposed on the rotational member, and a motor for rotating the rotational member. The motor has a core, projecting portions extending from the core, and motor coils each wound around a respective one of the projecting portions. The motor is disposed opposite to and spaced-apart from the permanent magnet for rotating the rotational member and contactlessly controlling an axial position of the rotational member along the rotary axis only by a magnetic forces generated between the permanent magnet, the core and the motor coils. A magnetic radial bearing contactlessly controls a radial position of the rotational member. | 5 |
This application is a division of application Ser. No. 07/385,840, filed Jul. 27, 1989 now U.S. Pat. No. 5,034,393.
FIELD OF THE INVENTION
This invention provides new compounds that have excellent plant fungicide activity. Some of the compounds have also demonstrated insecticidal and miticidal activity. The invention also provides compositions and combination products that contain a compound of the invention as active ingredient, as well as providing fungicidal, miticidal, and insecticidal methods.
There is an acute need for new fungicides, insecticides, and miticides, because target pathogens are rapidly developing resistance to currently used pesticides. Widespread failure of N-substituted azole fungicides to control barley mildew was observed in 1983, and has been attributed to the development of resistance. At least 50 species of fungi have developed resistance to the benzimidazole fungicides. The field performance of DMI (demethylation inhibitor) fungicides, which are now widely relied on to protect cereal crops from powdery mildew, has declined since they were introduced in the 1970's. Even recently introduced fungicides, like the acylalanines, which initially exhibited excellent control of potato late blight and grape downy mildew in the field, have become less effective because of widespread resistance. Similarly, mites and insects are developing resistance to the miticides and insecticides in current use. Resistance to insecticides in arthropods is widespread, with at least 400 species resistant to one or more insecticides. The development of resistance to some of the older insecticides, such as DDT, the carbamates, and the organophosphates, is well known. But resistance has even developed to some of the newer pyrethroid insecticides and miticides. Therefore a need exists for new fungicides, insecticides, and miticides.
SUMMARY OF THE INVENTION
This invention provides compounds of the formula (1): ##STR1## wherein one or two of A, B, E, or D are N, and the others are CR 1 or A, E, and D are N and B is CR 1 ; where R 1 and R 2 are independently H, halo, (C 1 -C 4 ) alkyl, (C 3 -C 4 ) branched alkyl, (C 1 -C 4 ) alkoxy, halo (C 1 -C 4 ) alkyl, phenyl, or substituted phenyl;
X is O, S, SO, SO 2 , NR 3 , or CR 4 R 5 , where R 3 is H, (C 1 -C 4 ) alkyl, or (C 1 -C 4 ) acyl, and R 4 and R 5 are independently H, (C 1 -C 4 ) acyl, (C 1 -C 4 ) alkyl, (C 2 -C 4 ) alkenyl or -alkynyl, CN, or OH, or R 4 and R 5 combine to form a carbocyclic ring containing four to six carbon atoms;
Y is a bond or an alkylene chain one to six carbon atoms long, optionally including a carbocyclic ring, and optionally including a hetero atom selected from O, NR 3 , S, SO, SO 2 , or SiR 20 R 21 , where R 3 is as defined above and R 20 and R 21 are independently (C 1 -C 4 ) alkyl, (C 3 -C 4 ) branched alkyl, phenyl, or substituted phenyl, and optionally substituted with (C 1 -C 4 ) alkyl, (C 2 -C 4 ) alkenyl or- alkynyl, branched (C 3 -C 7 ) alkyl, (C 3 -C 7 ) cycloalkyl or -cycloalkenyl, halo, hydroxy, or acetyl, and
Z is
(a) a C 1 -C 12 saturated or unsaturated hydrocarbon chain, straight chain or branched optionally including a hetero atom selected from O, S, SO, SO 2 , or SiR 20 R 21 , where R 20 and R 21 are as defined above and optionally substituted with halo, halo (C 1 -C 4 ) alkoxy, hydroxy, (C 3 -C 8 ) cycloalkyl or cycloalkenyl, or (C 1 -C 4 ) acyl;
(b) (C 3 -C 8 ) cycloalkyl or cycloalkenyl, optionally substituted with (C 1 -C 4 ) alkyl, (C 1 -C 4 ) alkoxy, halo (C 1 -C 4 ) alkyl, halo (C 1 -C 4 ) alkoxy, halo, hydroxy, or (C 1 -C 4 ) acyl;
(c) a phenyl group of the formula (2) ##STR2## where R 6 to R 10 are independently H, halo, I, (C 1 -C 10 ) alkyl, (C 3 -C 8 ) alkenyl or -alkynyl, branched (C 3 -C 6 ) alkyl, -alkenyl, or -alkynyl, (C 3 -C 8 ) cycloalkyl or -cycloalkenyl, halo (C 1 -C 7 ) alkyl, (C 1 -C 7 ) alkoxy, (C 1 -C 7 ) alkylthio, halo (C 1 -C 7 ) alkoxy, phenoxy, substituted phenoxy, phenylthio, substituted phenylthio, phenyl, substituted phenyl, NO 2 , acetoxy, OH, CN, SiR 11 R 12 R 13 , OSiR 11 R 12 R 13 , NR 14 R 15 , S(O)R 16 , or SO 2 R 17 where R 11 , R 12 , and R 13 are independently (C 1 -C 4 ) alkyl, (C 3 -C 4 ) branched alkyl, phenyl, or substituted phenyl, R 14 and R 15 are independently H, (C 1 -C 4 ) alkyl, or (C 1 -C 4 ) acyl, and R 16 and R 17 are (C 1 -C 10 ) alkyl, phenyl, or substituted phenyl;
(d) a furyl group of formula (3) ##STR3## where R 18 is H, halo, halomethyl, CN, NO 2 , (C 1 -C 4 ) alkyl, (C 3 -C 4 ) branched alkyl, phenyl, or (C 1 -C 4 ) alkoxy;
(e) a thienyl group of the formula (4) ##STR4## where R 18 is as defined in paragraph (d); (f) a group of formula (5) or (6) ##STR5## where R 18 is as defined in paragraph (d), J is N or CH, and G is O, NR 19 , or S, provided that if J is not N then G is NR 19 , where R 19 H, (C 1 -C 4 ) alkyl, (C 1 -C 4 ) acyl, phenylsulfonyl, or substituted phenylsulfonyl;
(g) a group selected from
optionally substituted naphthyl, dihydronaphthyl, tetrahydronaphthyl, and decahydronaphthyl;
optionally substituted pyridyl;
optionally substituted indolyl;
and 1,3-benzodioxolyl;
or an acid addition salt of a compound of formula (1);
provided that the following compounds are excluded:
1) pyrido[2,3-d]pyrimidines of formula (1) wherein X is NR 3 and --Y--Z is benzyl, or X is NR 3 , Y is an alkylene chain containing an O or S atom adjacent to Z, and Z is either unsubstituted phenyl or a substituted phenyl group other than one substituted with
branched (C 3 -C 6 ) alkyl,
halo (C 1 -C 4 ) alkyl,
halo (C 1 -C 4 ) alkoxy,
phenyl,
substituted phenyl,
phenoxy,
substituted phenoxy,
phenylthio,
substituted phenylthio,
SiR 11 R 12 R 13 , or
OSiR 11 R 12 R 13 ;
2) pyrido[3,4-d]pyrimidines of formula (1) wherein X is NR 3 , Z is unsubstituted phenyl, and R 2 is methyl; and
3) pyrido[3,4-d]pyrimidines of formula (1) wherein X is NR 3 and --Y--Z is benzyl or isoamyl.
Proviso (1) excludes compounds that are described as fungicides in Japanese patent application 5108806 of Sankyo. Proviso (2) excludes compounds for which cytokinin activity is reported in Agri. Biol. Chem., 50, 2243-49 (1986). Proviso (3) excludes compounds for which cytokinin activity is reported in Agri. Biol. Chem., 50, 495-97 (1986).
The fungicide combinations of the invention comprise at least 1% by weight of a compound of formula (1), excluding compounds of proviso (1) but including those of provisos (2) and (3), in combination with a second plant fungicide.
The fungicide compositions of the invention comprise a disease inhibiting and phytologically acceptable amount of compound of formula (1), excluding compounds of proviso (1) but including those of provisos (2) and (3), in combination with a phytologically-acceptable carrier. Such compositions may optionally contain additional active ingredients, such as an additional fungicidal, miticidal, or insecticidal ingredient.
The fungicidal method of the invention comprises applying to the locus of a plant pathogen a disease inhibiting and phytologically acceptable amount of a compound of formula (1), excluding compounds of proviso (1) but including those of provisos (2) and (3).
The insecticide and miticide combinations of the invention comprise at least 1% by weight of a compound of formula (1), including compounds of provisos (1) to (3), in combination with a second insecticide or miticide.
The insecticide and miticide compositions of the invention comprise an insect- or mite-inactivating amount of a compound of formula (1), including compounds of provisos (1) to (3), in combination with a carrier. Such compositions may optionally contain additional active ingredients, such as an additional fungicidal, miticidal, or insecticidal ingredient.
The insecticidal or miticidal method of the invention comprises applying to the locus to be protected an insect- or mite-inactivating amount of a compound of formula (1), including compounds of provisos (1) to (3), or of a combination described above.
DETAILED DESCRIPTION OF THE INVENTION
Throughout this document, all temperatures are given in degrees Celsius, and all percentages are weight percentages unless otherwise stated.
The term "halo" refers to a F, Cl, or Br atom.
The term "(C 1 -C 7 ) alkoxy" refers to straight or branched chain alkoxy groups.
The term "(C 1 -C 7 ) alkylthio" refers to straight and branched chain alkylthio groups.
The term "halo (C 1 -C 7 ) alkyl" refers to a (C 1 -C 7 ) alkyl group, straight chain or branched, substituted with one or more halo atoms.
The term "halo (C 1 -C 7 ) alkoxy" refers to a (C 1 -C 7 ) alkoxy group substituted with one or more halo groups.
The term "halo (C 1 -C 4 ) alkylthio" refers to a (C 1 -C 4 ) alkylthio group, straight chain or branched, substituted with one or more halo atoms.
The term "substituted phenyl" refers to phenyl substituted with up to three groups selected from halo, I, (C 1 -C 10 ) alkyl, branched (C 3 -C 6 ) alkyl, halo (C 1 -C 4 ) alkyl, hydroxy (C 1 -C 4 ) alkyl, (C 1 -C 4 ) alkoxy, halo (C 1 -C 4 ) alkoxy, phenoxy, substituted phenoxy, phenyl, substituted phenyl, NO 2 , OH, CN, (C 1 -C 4 ) alkanoyloxy, or benzyloxy.
The terms "substituted naphthyl", "substituted pyridyl" and "substituted indolyl" refer to these ring systems substituted with halo, halo (C 1 -C 4 ) alkyl, CN, NO 2 , (C 1 -C 4 ) alkyl, (C 3 -C 4 ) branched alkyl, phenyl, substituted phenyl, (C 1 -C 4 ) alkoxy, or halo (C 1 -C 4 ) alkoxy.
The term "substituted phenoxy" refers to phenoxy substituted with up to three groups selected from halo, I, (C 1 -C 10 ) alkyl, branched (C 3 -C 6 ) alkyl, halo (C 1 -C 7 ) alkyl, hydroxy (C 1 -C 7 ) alkyl, (C 1 -C 7 ) alkoxy, halo (C 1 -C 7 ) alkoxy, phenoxy, substituted phenoxy, phenyl, substituted phenyl, NO 2 , OH, CN, (C 1 -C 4 ) alkanoyloxy, or benzyloxy.
The term "carbocyclic ring" refers to a saturated or unsaturated carbocyclic ring containing three to seven carbon atoms.
The terms "substituted phenylthio" and "substituted phenyl sulfonyl" refer to such groups substituted with up to three groups selected from halo, I, (C 1 -C 10 ) alkyl, branched (C 3 -C 6 ) alkyl, halo (C 1 -C 7 ) alkyl, hydroxy (C 1 -C 7 ) alkyl, (C 1 -C 7 ) alkoxy, halo (C 1 -C 7 ) alkoxy, phenoxy, substituted phenoxy, phenyl, substituted phenyl, NO 2 , OH, CN, (C 1 -C 4 ) alkanoyloxy, or benzyloxy.
The term "unsaturated hydrocarbon chain" refers to a hydrocarbon chain containing one or two sites of unsaturation.
The term "HPLC" refers to a high-performance liquid chromatography.
Compounds
Compounds of formula (1) wherein A is N and B, E, and D are CR 1 are pyrido [3,2-d]pyrimidines.
Compounds of formula (1) wherein B is N and A, E, and D are CR 1 are pyrido [4,3-d]pyrimidines.
Compounds of formula (1) wherein E is N and A, B, and D are CR 1 are pyrido[3,4-d]pyrimidines.
Compounds of formula (1) wherein D is N and A, B, and E are CR 1 are pyrido[2,3-d]pyrimidines.
Compounds of formula (1) wherein A and D are N and B and E are CR 1 are pteridines (or pyrazino[2,3-d]pyrimidines.
Compounds of formula (1) wherein B and D are N and A and E are CR 1 are pyrimido[4,5-d]pyrimidines.
Compounds of formula (1) wherein E and D are N and A and B are CR 1 are pyrimido[4,5-c]pyridazines.
Compounds of formula (1) wherein A and E are N and B and D are CR 1 are pyrimido[5,4-d]pyrimidines.
Compounds of formula (1) wherein A and B are N and E and D are CR 1 are pyrimido[5,4-c]pyridazines.
Compounds of formula (1) wherein B and E are N and A and D are CR 1 are pyrimido[4,5-d]pyridazines.
Compounds of formula (1) wherein A, E, and D are N and B is CR 1 are pyrimido[5,4-e]-1,2,4-triazines.
While all of the compounds of the invention are useful fungicides, certain classes are preferred for reasons of greater efficacy or ease of synthesis, viz:
(a) compounds of formula (1) wherein one of A, B, E, and D is N and the rest are CR 1 .
(b) compounds of class (a) wherein D is N and A, B, and E are CR 1 , i.e., pyrido[2,3-d]pyrimidine derivatives;
(c) compounds of formula (1) wherein Z is substituted phenyl;
(d) compounds of formula (1) wherein X is O;
and
(e) compounds of class (d) wherein Y is a chain at least two atoms long.
Synthesis
The compounds of this invention are made using well known chemical procedures. The required starting materials are commercially available, or they are readily synthesized using standard procedures.
Synthesis of Compounds Wherein X is O
The compounds of formula (1) wherein X is O are made by condensing a compound of formula (7): ##STR6## where R 2 , A, B, E, and D are as previously defined, and L is a leaving group such as F, Cl, Br, I, NO 2 , 1,2,4-triazol-1-yl, --O--Si(Me) 3 , arylthio, alkylthio, alkylsulfonyl, arylsulfonyl, alkoxy, or arylsulfinyl with an alcohol or phenol of the formula (8):
HO--Y--Z (8)
where
Y and Z are as previously defined.
For many of the examples, the reaction was carried out in toluene treated with dry HCl, at room temperature or with gentle heating.
Alternatively, and preferably, the reaction may be carried out in the presence of a strong base, such as sodium hydride, in a non-reactive organic solvent, such as DMF, at a temperature in the range of 0° to 25° C.
Synthesis of Compounds Wherein X is NR 3
The compounds of formula (1) wherein X is NR 3 are prepared by condensing a compound of formula (7) with an amine of the formula (9) ##STR7## where R 3 ' is H or (C 1 -C 4 ) alkyl, and
Y and Z are as previously defined. The chloride of formula (7) is allowed to react with an appropriate amine at a wide variety of temperatures (20°-180° C.), preferably in the presence of an acid acceptor, such as triethylamine. The reaction may be carried out neat, or in a non-reactive organic solvent. Compounds where R 3 is acyl are prepared from amines where R 3 is H, which were allowed to react with an acylating agent such as acetyl chloride or acetic anhydride. In cases where the starting material of formula (7) is one wherein R 1 or R 2 is Cl, a mixture of products is obtained which are separable using liquid chromatography.
Synthesis of Compounds Wherein X is CH 2
The compounds of formula (1) wherein X is CH 2 can be made using the process described in J. Heterocyclic Chemistry, Vol. 14, p. 1081-1083 (1977) by A. Scoville and F. X. Smith. This process entails preparation of a barbituric acid of the formula (10) ##STR8## which is then hydrolyzed and decarboxylated by dissolving the intermediate in a solution of sodium hydroxide and water, refluxing, then making the solution slightly acidic with hydrochloric acid and again refluxing.
The acid addition salts of compounds of formula (1) are obtained in the usual way.
Accordingly, the invention also provides a process for preparing a compound of formula (1) which comprises:
(a) condensing a compound of formula (7) ##STR9## wherein R 1 , R 2 , A, B, E, and D are as previously defined, and L is a leaving group with an alcohol of the formula (8):
HO--Y--Z (8)
wherein Y and Z are as previously defined to produce a compound of formula (1) wherein X is O; or
(b) condensing a compound of formula (7) as defined above with an amine of the formula (9) ##STR10## where R 3 ' is H or (C 1 -C 4 ) alkyl, and Y and Z are as previously defined, to provide a compound of formula (1) where X is NR 3 '; or
(c) acylating a compound of formula (1) wherein X is NR 3 ' to provide a compound of formula (1) wherein X is NR 3 and R 3 is acyl; or
(d) hydrolyzing and decarboxylating a compound of formula (10) ##STR11## to produce a compound of formula (1) wherein X is CH 2 .
Preparation of Pyridopyrimidine, Pyrimidopyrimidine, and Pteridine Starting Materials
4-Hydroxyridopyrimidine starting materials are commercially available or readily prepared using conventional procedures. For example, useful synthetic procedures are described in
R. K. Robins & G. H. Hitchings, J. Am. Chem. Soc., 77, 2256 (1955);
S. Gabriel & J. Colman, Chem. Ber., 35, 2831 (1902); and
C. C. Price & D. Y. Curtin, J. Am. Chem. Soc., 68, 914 (1946).
4-Hydroxypyrimido[4,5-d]pyrimidines can be prepared using the procedure described in E. C. Taylor, et al., J. Amer. Chem. Soc., 82, 6058 (1960).
4-Hydroxypteridines can be prepared using the procedures described in A. Albert, D. J. Brown and G. Cheesman, J. Chem. Soc., 474 (1951).
4-Hydroxypyrimido[4,5-c]pyridazines can be prepared by the procedures described in J. L. Styles and R. W. Morrison, J. Org. Chem., 50, 346 (1985).
4-Hydroxypyrimido[5,4-d]pyrimidines can be prepared by the procedures described in F. A. Gianturro, P. Gramaccioni, and A. Vaciago, Gazz. Chim. Ital., 99, 1042 (1969).
4-Hydroxypyrimido[5,4-c]pyridazines can be prepared by the procedures described in R. N. Castle and H. Murakami, J. Hetero. Chem., 5, 523 (1968).
4-Hydroxypyrimido[4,5-d]pyridazines can be prepared by the procedures described in R. N. Castle, J. Hetero. Chem., 5, 845 (1968).
4-Chloro derivatives of formula (7) wherein L is Cl are prepared by chlorodehydroxylation of the corresponding 4-keto compounds using conventional methods, for example by reaction with POCl 3 .
Intermediates of formula (7) wherein L is 1,2,4-triazol 1-yl, can be prepared, for example, by adding POCl 3 dropwise to a mixture of a 4-hydroxypyridopyrimidine (1 equiv.) and 1,2,4-triazole (3 equiv.) in pyridine at a temperature from 20° to 100° C.
EXAMPLES 1-72
The following examples are compounds actually prepared by the above described general procedures. The melting point is given for each compound. In addition, although the data has not been included, each compound was fully characterized by NMR, IR, mass spectra, and combustion analysis. Specific illustrative preparations for the compounds of Examples follow the tabular listing.
______________________________________EXAMPLENUMBER COMPOUND M.P.______________________________________ 1 4-(4-fluorophenoxy)pyrido[2,3-d]- 142-144° C. pyrimidine 2 4-[2-[4-( .sub.. i-propyl)phenyl]ethyl- 198-200° C. amino]pyrido[2,3-d]pyrimidine 3 4-[2-(4-chlorophenyl)ethoxy]pyrido- 126-128° C. [2,3-d]pyrimidine 4 4-[2-(4-chlorophenyl)ethoxy]pyrido- 86° C. [3,2-d]pyrimidine 5 4-[2-[4-( .sub.- t-butyl)phenyl]ethylamino]- 77-78° C. pyrido[3,2-d]pyrimidine 6 4-(2-chloro-4-fluorophenoxy)pyrido- 181-182° C. [2,3-d]pyrimidine 7 4-[2-(4-ethoxyphenyl)ethoxy]pyrido- 74-75° C. [3,2-d]pyrimidine 8 N-(2-phenylethyl)pyrido[2,3-d]- 252-254° C. pyrimidin-4-amine 9 N-[2-(2-naphthalenyl)ethyl]pyrido- 247-251° C. [2,3-d]pyrimidin-4-amine10 4-[2-(2,4-difluorophenyl)ethoxy]- 84-85° C. pyrido[2,3-d]pyrimidine11 4-[2-(4-ethoxylphenyl)ethoxy]pyrido- 62-64° C. [2,3-d]pyrimidine12 N-[2-[3-(trifluoromethyl)phenyl]- 190-193° C. ethyl]pyrido[2,3-d]pyrimidin-4-amine13 N-(4-phenylbutyl)pyrido[2,3-d]- 179-181° C. pyrimidin-4-amine14 N-(3-phenylpropyl)pyrido[2,3-d]- 195-198° C. pyrimidin-4-amine15 4-(2-phenylethoxy)pyrido[2,3-d]- 101-102° C. pyrimidine16 N-[2-(4-chlorophenyl)ethyl]pyrido- 271-275° C. [2,3-d]pyrimidin-4-amine17 4-[2-(4-methoxy-3-methylphenyl)- 113-114° C. ethoxy]pyrido[2,3-d]pyrimidine18 4-[3-(4-phenoxyphenyl)propoxy]- oil pyrido[2,3-d]pyrimidine19 N-[(4-chlorophenyl)methyl]pyrido- 252-255° C. [2,3-d]pyrimidin-4-amine20 N-[2-(2,6-difluorophenyl)ethyl]- 263-266° C. pyrido[2,3-d]pyrimidin-4-amine21 4-[2-[4-(trimethylsilyl)phenyl]- 90° C. ethoxy]pyrido[2,3-d]pyrimidine22 4-[2-(2-naphthalenyl)ethoxy]pyrido- 108° C. [2,3-d]pyrimidine23 4-[2-(4-methoxyphenyl)ethoxy]- 109-110° C. pyrido[2,3-d]pyrimidine24 4-(4-fluorophenoxy)pyrido[3,4-d]- 212-214° C. pyrimidine25 4-[2-[4-phenylphenyl]ethoxy]pyrido- 124-125° C. [2,3-d]pyrimidine26 4-[2-[4-( .sub.- t-butyl)phenyl]ethoxy]- 59-60° C. pyrido[3,-d]pyrimidine27 4-[2-[4-(t-butyl)phenyl]-ethyl- 209-211° C. amino]pyrido[2,3-d]pyrimidine28 4-[2-[4-( .sub.- i-propyl)phenyl]ethyl- 165-167° C. amino]pyrido[3,4-d]pyrimidine29 4-[2-[4-( .sub.- t-butyl)phenyl]ethoxy]- 55° C. pyrido[3,2-d] pyrimidine30 4-[2-[4-(trifluoromethyl)phenyl]- 65-67° C. ethoxy]pyrido[2,3-d]pyrimidine31 4-(4-fluorophenoxy)pyrido[3,2-d]- 149-151° C. pyrimidine32 4-[2-[4-(trimethylsilyl)phenyl]- 81° C. ethoxy]pyrido[3,4-d]pyrimidine33 4-[2-(4-ethoxyphenyl)ethoxy]pyrido- 87-88° C. [3,4-d]pyrimidine34 N-[2-(4-methoxyphenyl)ethyl]- 260-263° C. pyrido[2,3-d]pyrimidin-4-amine35 N-[2-(4-methoxyphenyl)ethyl]- 153-155° C. pyrido[3,4-d]pyrimidin-4-amine36 4-(2-[1,1'-biphenyl]-4-ylethoxy)- 137-138° C. pyrido[3,4-d]pyrimidine37 N-[2-[4-( .sub.- t-butyl)phenyl]ethyl]- 138-163° C. pyrido[3,4-d]pyrimidin-4-amine38 N-[2-(4-ethoxyphenyl)ethyl]- 174-176° C. pyrido[3,4-d]pyrimidin-4-amine39 N-(4-phenylbutyl)pyrido[3,4-]- 60-75° C. pyrimidin-4-amine40 N-[2-(4-ethoxyphenyl)ethyl]pyrido- 220-222° C. [2,3-d]pyrimidin-4-amine41 4-[2-[4-( .sub.- t-butyl)phenyl]ethoxy]- 77-79° C. pyrido[2,3-d]pyrimidine42 N-[[3-trifluoromethyl)phenyl]- 202-201° C. methyl]pyrido[2,3-d]pyrimidin-4- amine43 N-[[4-(trifluoromethoxy)phenyl]- 247-249° C. methyl]pyrido[2,3-d]pyrimidin-4- amine44 N-[2-(4-methylphenyl)ethyl]pyrido- 260-264° C. [2,3-d]pyrimidin-4-amine45 N-[2-(2-methoxyphenyl)ethyl]pyrido- 158-171° C. [2,3-d]pyrimidin-4-amine46 N-(2-phenylethyl)pyrido[3,4-d]- 134-137° C. pyrimidin-4-amine47 N-[4-(trifluoromethyl)phenyl]pyrido- 283-290° C. [2,3-d]pyrimidin-4-amine48 4-[[2-(4-methoxyphenyl)ethyl]amino]- 120-122° C. pyrido[3,2-d]pyrimidine49 N-(2-phenylethyl)pyrido[3,2-d]pyri- 135-137° C. midin-4-amine50 N-[2-[4-( .sub.- t-butyl)phenyl]ethyl]- 157-158° C. pyrido-[4,3-d]pyrimidin-4-amine51 N-[2-(2-naphthyl)ethyl]pyrido- 140-143° C. [3,2-d]pyrimidin-4-amine52 N-methyl-N-(2-phenylethyl)pyrido- 114-116° C. [2,3-d]pyrimidin-4-amine53 N-methyl-N-[phenylmethyl)pyrido- 99-101° C. [2,3-d]pyrimidin-4-amine54 4-[2-(4-methylphenyl)ethoxy]- 91-92° C. pyrido[2,3-d]pyrimidine55 4-[2-[4-( .sub.- t-butyl)phenyl]ethoxy]- 149° C. pteridine56 4-[2-(4-methylphenyl)ethoxy]pyrido- 74-75° C. [3,4-d]pyrimidine57 4-[2-(biphenyl)ethoxy]pyrido[3,2-d]- 83-84° C. pyrimidine58 4-[2-(4-methoxyphenyl)ethoxy]pyrido- 80-81° C. [3,4-d]pyrimidine59 4-[(4-methylphenyl)methoxy]pyrido- 110-111° C. [2,3-d]pyrimidine60 4-(2-cyclohexylethoxy)pyrido[2,3-d]- 72° C. pyrimidine61 4-[2-(phenyl)ethoxy]pyrido[3,4-d]- 77-78° C. pyrimidine62 4-[2-(4-chlorophenyl)ethoxy]pyrido- 108-109° C. [3,4-d]pyrimidine63 4-(3-phenylpropoxy)pyrido[2,3-d]- 34-36° C. pyrimidine64 4-[(2-phenylethyl)amino]pteridine 159-160° C.65 N-[2-(4-ethylphenyl)ethyl]pyrido- 218-220° C. [2,3-d]pyrimidin-4-amine66 N-(2-ethoxyethyl)pyrido[2,3-d]- N.A. pyrimidin-4-amine67 N-(2-methoxyethyl)pyrido[2,3-d]- 190-193° C. pyrimidin-4-amine68 N-[2-(2-chloro-6-fluorophenyl)- 248-251° C. ethyl]pyrido[2,3-d]pyrimidin-4-amine69 N-[3-(diethylamino)propyl]pyrido- 163-167° C. [2,3.d]pyrimidin-4-amine70 N-[2-[4-( .sub.- t-butyl)phenyl]ethyl]-4- 147° C. pteridinamine71 N-(phenylmethyl)pyrido[2,3-d]- 258-260° C. pyrimidin-4-amine72 4-[2-(2-methyl)ethoxy]pyrido- 128-129° C. [3,4-d]pyrimidine______________________________________
The procedures described in the following detailed examples are representative of the procedures used to prepare the compounds of the other examples.
Preparation 1
Pyrido[34-d]pyrimidin-4(3H)one
A mixture of 4 g of 3-amino-pyridine-4-carboxylic acid in 15 mL of formamide was heated in an oil bath to 160°-180° C. After one hour the mixture was allowed to cool. Then, the mixture was slurried in 25 mL of water and filtered. The product was recrystallized from water. Yield 3.3 g. M.P. 317° C. (with sublimation).
Preparation 2
Pyrido[3,2-d]pyrimidin-4(3H)one
A mixture of 6.5 g of 3-amino-pyridine-2-carboxylic acid in 9 g of formamide was heated in an oil bath while stirring. The temperature was increased from 130° C. to 180° C. over a two hour period, then the mixture was allowed to cool. The mixture was then diluted with water. The solids were collected and washed with fresh water, then dried. Yield 4.6 g. M.P. 346°-347° C.
Preparation 3
4-Chloropyrido[2,3-d]pyrimidine
A mixture of 17.8 g of Pyrido[2,3-d]pyrimidin(4(3H)one and 200 mL of POCl 3 was stirred under reflux for one hour. Excess POCl 3 was removed under vacuum, and then CH 2 Cl 2 , ice, and water were added. A black solid dissolved slowly. The organic layer was then separated, washed with aqueous NaHCO 3 , and dried over Na 2 SO 4 . Solvent was then removed under vacuum to leave a yellow solid, which was recrystallized from toluene/hexane. M.P. 137° dec.
Preparation 4
4-[1'-(1,2,4-triazolyl)]pyrido[2,3-d]-pyrimidine
A. A mixture of 28.5 g of Pyrido[2,3-d]-pyrimidin-4(3H)one and 40.1 g of 1,2,4-triazole in 500 mL of pyridine was stirred as 71.4 g of 4-chlorophenyl dichlorophosphate was added with modest cooling. The mixture was then stirred at room temperature. Then 2.5 L of CH 2 Cl 2 was added, and the mixture was washed successively with 500 mL of water, 1 L of 2% HCl, and 500 mL of water, then dried over MgSO 4 . Solvent was then evaporated, leaving a yellow solid, which was recrystallized from toluene/hexane to give 9.0 g first crop, M.P. 206°-210° C., 5.7 g second crop, M.P. 218°-220° C., 1.45 g third crop, M.P. 205°-209° C.
B. The title compound was also made by mixing 1.47 g of pyrido[2,3-d]pyrimidin-4(3H)one and 2.07 g of 1,2,4-triazole in 50 mL of pyridine and adding 1.12 mL of POCl 3 while stirring the mixture at room temperature. After stirring the mixture overnight, 500 mL of CH 2 Cl 2 was added, and the mixture was washed successively with 500 mL of 2% HCl and 500 mL of water, and then dried over MgSO 4 . Solvent was evaporated under vacuum to leave 0.4 of yellow solid, which was recrystallized from toluene/hexane. M.P. 217°-219° C.
Example 2
4-[2-[4-(i-propyl )phenyl]ethylamino]pyrido[2,3-d]pyrimidine
A mixture consisting of 1.98 g (0.01 mole) of 4-[1'-(1,2,4-triazolyl)]pyrido[2,3-d]pyrimidine, 1.63 g (0.01 mole) of 2-[4-(i-propyl)phenyl]ethylamine, and 50 mL of CHCl 3 was stirred at reflux for two hours. Then 1.01 g (0.01 mole) of triethyl amine was added, and the mixture was refluxed for four hours. After washing the mixture with water, the CHCl 3 layer was dried over MgSO 4 . The CHCl 3 was removed using a vacuum and the product was recrystallized from EtOH/H 2 O. Yield 1.5 g. This product was recrystallized from ethyl acetate. M.P. 200°-203° C.
Example 3
4-[2-(4-chlorophenyl)ethoxy]pyrido[2,3-d]pyrimidine
A mixture consisting of 1.48 g (7.5 mmole) of 4-[1'-(1,2,4-triazolyl)-pyrido[2,3-d]pyrimidine, 1.20 g of 2-(4-chlorophenyl)ethanol (7.5 mmole), and 50 mL of toluene which had been treated with dry HCl gas was stirred at room temperature, heated gently for about one and one half hours, then cooled. TLC indicated that the reaction was not complete, so additional alcohol was added and the mixture was warmed. After cooling the mixture, it was diluted with water and made basic with 1.0N NaOH. The product was extracted from the mixture into toluene, which was then washed with saturated brine, filtered through phase separating paper, and concentrated in vacuo. The oily residue that crystallized was chromatographed (silica gel, CH 2 Cl 2 →70% CH 2 Cl 2 /30% EtOAc). The fractions containing the major product were combined, and the product crystallized. The product was recrystallized from CH 2 Cl 2 /petroleum ether. Yield 1.05 g. M.P. 126°-128° C.
Example 26
4-[ 2-[4-(t-butyl)phenyl]ethoxy]pyrido[3,4-d]pyrimidine
To a suspension of 300 mg of 60% NaH in 15 mL of DMF was added 1.33 g of 2-[4-(t-butyl)phenyl]ethanol. The mixture was stirred at room temperature for 30 minutes. The 1.48 g of 4-[1'-(1,2,4-triazolyl)pyrido[3,4-d]pyrimidine was added and the mixture was stirred at room temperature overnight. Solvent was then removed in vacuo, azeotroping with xylene. The residue was diluted with water and the pH was adjusted to neutral by adding dilute HCl. The product was extracted into CH 2 Cl 2 , which was then washed with brine, dried over Na 2 SO 4 , filtered, and concentrated. The residue was adsorbed onto silica gel and chromatographed, eluting with CH 2 Cl 2 to 75/25 CH 2 Cl 2 /EtOAc. Fractions containing the major product were combined to give a thick oil which crystallized from petroleum ether. Yield 1.4 g. M.P. 59°-60° C.
Example 41
4-[2-[4-(t-butyl)phenyl]ethoxy]pyrido[2,3-d]pyrimidine
A mixture consisting of 1.86 g (0.011 mole) of 4-chloropyrido-[2,3-d]pyrimidine, 2.0 g (0.011 mole) of 2-[4-(t-butyl)phenyl]ethanol, and 40 mL of toluene containing a little HCl gas was stirred at room temperature. The mixture was then cooled, and a yellow solid was collected. This was washed with hexane, then partitioned between 1N NaOH and CH 2 Cl 2 . The CH 2 Cl 2 layer was dried over MgSO 4 , then the solvent was removed under vacuum to leave a yellow solid, which was recrystallized from hexane. Yield 2.5 g. M.P. 77°-79° C.
Example 50
4-[2-[4-(t-butyl)phenyl]ethylamino]pyrido[4,3-d]pyrimidine
A mixture consisting of 0.45 g of pyrido[4,3-d]pyrimidine-4-ol, 0.53 g of 2-[4-(t-butyl)phenyl]ethylamine, about 40 mg of (NH 4 ) 2 SO 4 in 4 mL of hexamethyldisilazane was refluxed for about five hours. The mixture was then cooled and excess disilazane was removed in vacuo. The residue was dissolved in CH 2 Cl 2 , and the solution was washed with water and filtered through phase separating paper. Evaporated the CH 2 Cl 2 and adsorbed the residue onto silica gel, which was applied to a thin silica pad and eluted with CH 2 Cl 2 →50% EtOAc/50% CH 2 Cl 2 →EtOAc. Fractions containing the major product were combined and the product which crystallized was recrystallized from hexane/EtOAc. Yield 0.2 g. M.P. 157°-158° C.
Example 55
4-[2-[4-(t-butyl)phenyl]ethoxy]pteridine
To a suspension of 2 g of 4-hydroxypteridine in 20 mL of CH 2 Cl 2 under nitrogen was added 1.2 g of pyridine. The mixture was cooled to -30° C. and over a 15 minute period a solution of 4.82 g of triphenyl phosphite in CH 2 Cl 2 was added simultaneously with addition of chlorine gas. The mixture was stirred for one and one half hours while maintaining the temperature at -15° to -20° C. The mixture was then allowed to warm to 10° C., and a solution of 2.67 g of 2-[4-(t-butyl)phenyl]ethanol in CH 2 Cl 2 was added. The resulting mixture was refluxed for 45 minutes, then cooled and diluted into toluene. The toluene solution was washed with dilute base, then filtered through phase separating paper and concentrated in vacuo. The resulting bluish oil was adsorbed onto silica gel and chromatographed (silica gel, CH 2 Cl 2 →80% CH 2 Cl 2 , 20% EtOAc). Fractions containing the major product were combined. The product was then recrystallized from petroleum ether/CH 2 Cl 2 . Yield 60 mg. M.P. 149° C.
Fungicide Utility
The compounds of the present invention have been found to control fungi, particularly plant pathogens. When employed in the treatment of plant fungal diseases, the compounds are applied to the plants in a disease inhibiting and phytologically acceptable amount. The term "disease inhibiting and phytologically acceptable amount," as used herein, refers to an amount of a compound of the invention which kills or inhibits the plant disease for which control is desired, but is not significantly toxic to the plant. This amount will generally be from about 1 to 1000 ppm, with 10 to 500 ppm being preferred. The exact concentration of compound required varies with the fungal disease to be controlled, the type formulation employed, the method of application, the particular plant species, climate conditions and the like. A suitable application rate is typically in the range from 0.25 to 4 lb/A. The compounds of the invention may also be used to protect stored grain and other non-plant loci from fungal infestation.
Greenhouse Tests
The following experiments were performed in the laboratory to determine the fungicidal efficacy of the compounds of the invention.
This screen was used to evaluate the efficacy of the present compounds against a variety of different organisms that cause plant diseases.
The test compounds were formulated for application by dissolving 50 mg of the compound into 1.25 ml of solvent. The solvent was prepared by mixing 50 ml of "Tween 20" (polyoxyethylene (20) sorbitan monolaurate emulsifier) with 475 ml of acetone and 475 ml of ethanol. The solvent/compound solution was diluted to 125 ml with deionized water. The resulting formulation contains 400 ppm test chemical. Lower concentrations were obtained by serial dilution with the solvent-surfactant mixture.
The formulated test compounds were applied by foliar spray. The following plant pathogens and their corresponding plants were employed.
______________________________________ Designation inPathogen Following Table Host______________________________________Erysiphe graminis tritici POWD wheat(powdery mildew) MDEWPyricularia oryzae RICE rice(rice blast) BLASPuccinia recondita tritici LEAF wheat(leaf rust) RUSTBotrytis cinerea GRAY grape berries(gray mold) MOLDPseudoperonospora cubensis DOWN squash(downy mildew) MDEWCercospora beticola LEAF sugar beet(leaf spot) SPOTVenturia inaequalis APPL apple seedling(apple scab) SCABSeptoria tritici LEAF wheat(leaf blotch) BLOT______________________________________
The formulated technical compounds were sprayed on all foliar surfaces of the host plants (or cut berry) to past run-off. Single pots of each host plant were placed on raised, revolving pedestals in a fume hood. Test solutions were sprayed on all foliar surfaces. ALL treatments were allowed to dry and the plants were inoculated with the appropriate pathogens within 2-4 hours.
The following Table presents the activity of typical compounds of the present invention when evaluated in this experiment. The effectiveness of test compounds in controlling disease was rated using the following scale.
______________________________________0 = not tested against specific organism = 0-19% control at 400 ppm+ = 20-89% control at 400 ppm++ = 90-100% control at 400 ppm+++ = 90-100% control at 100 ppm______________________________________
______________________________________PLANT PATHOLOGY SCREENEXAMPLE POWD RICE LEAF GRAY DOWNNUMBER MDEW BLAST RUST MOLD MDEW______________________________________ 1 - - - - - 2 - - +++ - +++ 3 + +++ +++ - +++ 4 - ++ + - + 5 +++ +++ +++ + +++ 6 + - - - + 7 + - ++ - +++ 8 - - +++ - +++ 9 - - ++ - +10 ++ - +++ - +++11 ++ - +++ - +++12 - - ++ - +++13 - - +++ - +++14 - - + - +++15 + - +++ - +++16 - - + - -17 +++ +++ +++ - +++18 - ++ +++ - +++19 - - + - -20 - - - - +21 +++ - +++ - +++22 +++ - +++ - +++23 - +++ +++ - +++24 - - - - -25 +++ +++ +++ - +++26 +++ +++ +++ - +++27 - + +++ - +++28 +++ +++ +++ - +++29 ++ ++ ++ - +++30 +++ +++ +++ - +++31 - - - - -32 ++ ++ ++ - ++33 ++ - ++ - ++34 - + ++ - ++35 ++ +++ +++ - +++36 - ++ + - +++37 ++ +++ +++ - +++38 ++ ++ +++ - +++39 +++ ++ +++ - +++40 + + +++ - ++41 +++ +++ +++ - +++43 - - ++ - +44 - - + - ++45 - - ++ - ++46 ++ - ++ - ++47 - - - - ++48 ++ ++ ++ - ++49 + - ++ - ++50 - - ++ - ++51 +++ + +++ - +++52 ++ - ++ - ++53 - - + 0 +54 ++ - ++ 0 ++55 - - + - +++61 ++ ++ ++ - ++65 - - +++ - +++67 - - - 0 ++72 + ++ +++ - +++______________________________________
Combinations
Fungal disease pathogens are known to develop resistance to fungicides. When strains resistant to a fungicide do develop, it becomes necessary to apply larger and larger amounts of the fungicide to obtain desired results. To retard the development of resistance to new fungicides, it is desirable to apply the new fungicides in combination with other fungicides. Use of a combination product also permits the product's spectrum of activity to be adjusted.
Accordingly, another aspect of the invention is a fungicidal combination comprising at least 1% by weight of a compound of formula (1) in combination with a second fungicide.
Contemplated classes of fungicides from which the second fungicide may be selected include:
1) N-substituted azoles, for example propiconazole, triademefon, flusilazol, diniconazole, ethyltrianol, myclobutanil, and prochloraz;
2) pyrimidines, such as fenarimol and nuarimol;
3) morpholines, such as fenpropimorph and tridemorph;
4) piperazines, such as triforine; and
5) pyridines, such as pyrifenox. Fungicides in these five classes all function by inhibiting sterol biosynthesis. Additional classes of contemplated fungicides, which have other mechanisms of action include:
6) dithiocarbamates, such as maneb and mancozeb;
7) phthalimides, such as captafol;
8) isophthalonitrites, such as chlorothalonil;
9) dicarboximides, such as iprodione;
10) benzimidazoles, such as benomyl and carbendazim;
11) 2-aminopyrimidines, such as ethirimol;
12) carboxamides, such as carboxin;
13) dinitrophenols, such as dinocap; and
14) acylalanines, such as metalaxyl.
The fungicide combinations of the invention contain at least 1%, ordinarily 20 to 80%, and more typically 50 to 75% by weight of a compound of formula (1).
Insecticide and Miticide Utility
The compounds of the invention are also useful for the control of insects and mites. Therefore, the present invention also is directed to a method for inhibiting an insect or mite which comprises applying to a locus of the insect or mite an insect- or mite-inhibiting amount of a compound of formula (1).
The compounds of the invention show activity against a number of insects and mites. More specifically, the compounds show activity against melon aphid, which is a member of the insect order Homoptera. Other members of the Homoptera include leafhoppers, planthoppers, pear pyslla, apple sucker, scale insects, whiteflies, spittle bugs as well as numerous other host specific aphid species. Activity has also been observed against greenhouse thrips, which are members of the order Thysanoptera. The compounds also show activity against Southern armyworm, which is a member of the insect order Lepidoptera. Other typical members of this order are codling moth, cutworm, clothes moth, Indianmeal moth, leaf rollers, corn earworm, European corn borer, cabbage worm, cabbage looper, cotton bollworm, bagworm, eastern tent caterpillar, sod webworm, and fall armyworm.
Representative mite species with which it is contemplated that the present invention can be practiced include those listed below.
__________________________________________________________________________FAMILY SCIENTIFIC NAME COMMON NAME__________________________________________________________________________ACARIDAE Aleurobius farinae Rhizoglyphus echinopus Bulb mite Rhizoglyphus elongatus Rhizoglyphus rhizophagus Rhizoglyphus sagittatae Rhizoglyphus tarsalisERIOPHYIDAE Abacarus farinae Grain rust mite Aceria brachytarsus Acalitus essigi Redberry mite Acera ficus Aceria fraaxinivorus Aceria granati Aceria parapopuli Eriophyes sheldoni Citrus bud mite Aceria tulipae Aculus carnutus Peach silver mite Aculus schlechtendali Apple rust mite Colomerus vitis Grape erineum mite Eriophyes convolvens Eriophyes insidiosus Eriophyes malifoliae Eriophyes padi Eriophyes pruni Epitrimerus pyri Pear leaf blister mite Eriophyes ramosus Eriophyes sheldoni Citrus bud mite Eriophyes ribis Phyllocoptes gracilis Dryberry mite Phyllocoptruta oleivora Citrus rust mite Phytoptus ribis Trisetacus pini Vasates amygdalina Vasates eurynotus Vasates quadripedes Maple bladdergall mite Vasates schlechtendaliEUPODIDAE Pentaleus major Winter grain mite Linopodes spp.NALEPELLIDAE Phylocoptella avellanae Filbert bud mitePENTHALEIDAE Halotydeus destrustorPYEMOTIDAE Pyemotes tritici Straw itch mite Siteroptes cerealiumTARSONEMIDAE Polyphagotarsonemus latus Broad mite Steneotarsonemus pallidus Cyclamen miteTENUIPALPIDAE Brevipalpus californicus Brevipalpus obovatus Privet mite Brevipalpus lewisi Citrus flat mite Dolichotetranychus floridanus Pineapple flase spider mite Tenuipalpes granati Tenuipalpes pacificusTETRANYCHIDAE Bryobia arborea Bryobia practiosa Clover mite Bryobia rubrioculus Brown mite Eotetranychus coryli Eotetranychus hicoriae Pecan deaf scorch mite Eotetranychus lewisi Eotetranychus sexmaculatus Sixspotted spider mite Eotetranychus willametti Eotetranychus banksi Texas citrus mite Oligonychus ilicis Southern red mite Oligonychus pratensis Banks grass mite Oligonychus ununguis Spruce spider mite Panonychus citri Citrus red mite Panonychus ulmi European red mite Paratetranychus modestus Paratetranychus pratensis Paratetranychus viridis Petrobia latens Brown wheat mite Schizotetranychus celarius Bamboo spider mite Schizotetranychus pratensis Tetranychus canadensis Fourspotted spider mite Tetranychus cinnabarinus Carmine spider mite Tetranychus mcdanieli McDaniel spider mite Tetranychus pacificus Pacific spider mite Tetranychus schoenei Schoene spider mite Tetranychus urticae Twospotted spider mite Tetranychus turkestani Strawberry spider mite Tetranychus desertorum Desert spider mite__________________________________________________________________________
The compounds are useful for reducing populations of insects and mites, and are used in a method of inhibiting an insect or mite population which comprises applying to a locus of the insect or arachnid an effective insect- or mite-inactivating amount of a compound of formula (1). The "locus" of insects or mites is a term used herein to refer to the environment in which the insects or mites live or where their eggs are present, including the air surrounding them, the food they eat, or objects which they contact. For example, plant-ingesting insects or mites can be controlled by applying the active compound to plant parts, which the insects or mites eat, particularly the foliage. It is contemplated that the compounds might also be useful to protect textiles, paper, stored grain, or seeds by applying an active compound to such substance. The term "inhibiting an insect or mite" refers to a decrease in the numbers of living insects or mites; or a decrease in the number of viable insect or mite eggs. The extent of reduction accomplished by a compound depends, of course, upon the application rate of the compound, the particular compound used, and the target insect or mite species. At least an insect-inactivating or mite-inactivating amount should be used. The terms "insect-inactivating amount" and "mite-inactivating amount" are used to describe the amount, which is sufficient to cause a measurable reduction in the treated insect or mite population. Generally an amount in the range from about 1 to about 1000 ppm active compound is used.
In a preferred embodiment, the present invention is directed to a method for inhibiting a mite which comprises applying to a plant an effective mite-inactivating amount of a compound of formula (1) in accordance with the present invention.
Mite/Insect Screen
The compounds of Examples 1-10 were tested for miticidal and insecticidal activity in the following mite/insect screen.
Each test compound was formulated by dissolving the compound in acetone/alcohol (50:50) mixture containing 23 g of "TOXIMUL R" (sulfonate/nonionic emulsifier blend) and 13 g of "TOXIMUL S" (sulfonate/nonionic emulsifier blend) per liter. These mixtures were then diluted with water to give the indicated concentrations.
Twospotted spider mites (Tetranychus urticae Koch) and melon aphids (Aphis gossypii Glover) were introduced on squash cotyledons and allowed to establish on both leaf surfaces. Other plants in the same treatment pot were left uninfested. The leaves were then sprayed with 5 ml of test solution using a DeVilbiss atomizing sprayer at 10 psi. Both surfaces of the leaves were covered until runoff, and then allowed to dry for one hour. Two uninfested leaves were then excised and placed into a Petri dish containing larval southern armyworm (Spodopetra eridania Cramer).
Activity on Southern corn rootworm (Diabrotica undecimpuctata howardi Barber) was evaluated by adding two ml of tap water, a presoaked corn seed, and 15 g of dry sandy soil to a one ounce plastic container. The soil was treated with 1 mL of test solution containing a predetermined concentration of test compound. After six to 12 hours of drying, five 2-3 instar corn rootworm larvae were added to the individual cups, which were then capped and held at 23° C.
After standard exposure periods, percent mortality and phytotoxicity were evaluated. Results for the compounds found to be active are reported in the following table. The remaining compounds showed no activity. The following abbreviations are used in the following table:
CRW refers to corn rootworm
SAW refers to Southern armyworm
SM refers to twospotted spider mites
MA refers to melon aphids.
______________________________________MITE AND INSECT SCREEN SAW SM MAEXAMPLE RATE RESULTS RESULTS RESULTSNUMBER PPM % % %______________________________________1 400 0 0 02 200 0 0 0 400 80 0 03 200 0 0 0 400 0 0 04 200 0 0 0 400 0 0 05 200 0 100 90 400 0 100 1006 400 0 0 07 200 0 0 90 400 0 0 08 200 0 0 0 400 0 0 09 200 80 0 0 400 70 0 010 200 0 90 90 200 0 80 100 400 0 100 10011 200 0 100 100 400 0 100 10012 200 0 0 0 400 0 0 013 200 60 0 0 400 0 0 014 200 0 0 50 400 0 0 015 200 0 0 0 400 0 80 8016 200 80 0 0 400 0 0 017 200 0 80 80 400 0 60 8018 200 0 30 80 400 0 90 9019 200 0 0 0 400 0 0 020 200 0 0 0 400 0 0 021 200 70 100 100 400 0 100 6022 200 90 100 100 400 0 60 8023 200 0 0 90 400 0 40 8024 400 0 0 025 200 80 50 60 400 0 0 026 200 0 100 80 400 0 0 027 200 0 0 20 400 0 0 028 200 0 20 30 400 0 0 029 200 0 100 90 400 0 80 8030 200 0 100 100 400 0 100 10031 400 0 0 032 200 60 100 90 400 0 0 033 200 0 0 0 400 0 0 034 200 60 0 0 400 0 0 035 200 0 0 60 400 0 0 036 200 0 0 0 400 0 0 037 200 0 0 0 400 0 0 038 200 20 0 0 400 20 0 039 200 0 80 0 400 0 0 040 200 20 0 0 400 0 0 041 200 0 100 100 400 0 100 10044 200 0 0 0 400 40 0 045 200 0 0 0 400 0 0 046 400 0 0 047 200 0 20 90 400 0 0 048 200 0 80 60 400 0 0 049 200 0 0 0 400 0 0 050 200 0 90 70 400 0 0 051 200 50 80 80 400 40 0 052 200 0 0 0 400 0 100 10053 400 0 0 054 400 0 100 10055 400 0 0 057 200 0 90 90 400 0 80 10061 400 0 0 N.A.64 400 0 0 065 200 90 0 0 400 100 0 067 400 0 0 10068 400 0 0 072 200 0 0 0 400 0 0 0______________________________________
Compositions
The compounds of this invention are applied in the form of compositions which are important embodiments of the invention, and which comprise a compound of this invention and a phytologically-acceptable inert carrier. The compositions are either concentrated formulations which are dispersed in water for application, or are dust or granular formulations which are applied without further treatment. The compositions are prepared according to procedures and formulae which are conventional in the agricultural chemical art, but which are novel and important because of the presence therein of the compounds of this invention. Some description of the formulation of the compositions will be given, however, to assure that agricultural chemists can readily prepare any desired composition.
The dispersions in which the compounds are applied are most often aqueous suspensions or emulsions prepared from concentrated formulations of the compounds. Such water-soluble, water-suspendable or emulsifiable formulations are either solids usually known as wettable powders, or liquids usually known as emulsifiable concentrates or aqueous suspensions. Wettable powders, which may be compacted to form water dispersible granules, comprise an intimate mixture of the active compound, an inert carrier and surfactants. The concentration of the active compound is usually from about 10% to about 90% by weight. The inert carrier is usually chosen from among the attapulgite clays, the montmorillonite clays, the diatomaceous earths, or the purified silicates. Effective surfactants, comprising from about 0.5% to about 10% of the wettable powder, are found among the sulfonated lignins, the condensed naphthalenesulfonates, the naphthalenesulfonates, the alkylbenzenesulfonates, the alkyl sulfates, and non-ionic surfactants such as ethylene oxide adducts of alkyl phenols.
Emulsifiable concentrates of the compounds comprise a convenient concentration of a compound, such as from about 50 to about 500 grams per liter of liquid, equivalent to about 10% to about 50%, dissolved in an inert carrier which is either a water miscible solvent or a mixture of water-immiscible organic solvent and emulsifiers. Useful organic solvents include aromatics, especially the xylenes, and the petroleum fractions, especially the high-boiling naphthalenic and olefinic portions of petroleum such as heavy aromatic naphtha. Other organic solvents may also be used, such as the terpenic solvents including rosin derivatives, aliphatic ketones such as cyclohexanone, and complex alcohols such as 2-ethoxyethanol. Suitable emulsifiers for emulsifiable concentrates are chosen from conventional nonionic surfactants, such as those discussed above.
Aqueous suspensions comprise suspensions of water-insoluble compounds of this invention, dispersed in an aqueous vehicle at a concentration in the range from about 5% to about 50% by weight. Suspensions are prepared by finely grinding the compound, and vigorously mixing it into a vehicle comprised of water and surfactants chosen from the same types discussed above. Inert ingredients, such as inorganic salts and synthetic or natural gums, may also be added, to increase the density and viscosity of the aqueous vehicle. It is often most effective to grind and mix the compound at the same time by preparing the aqueous mixture, and homogenizing it in an implement such as a sand mill, ball mill, or piston-type homogenizer.
The compounds may also be applied as granular compositions, which are particularly useful for applications to the soil. Granular compositions usually contain from about 0.5% to about 10% by weight of the compound, dispersed in an inert carrier which consists entirely or in large part of clay or a similar inexpensive substance. Such compositions are usually prepared by dissolving the compound in a suitable solvent, and applying it to a granular carrier which has been pre-formed to the appropriate particle size, in the range of from about 0.5 to 3 mm. Such compositions may also be formulated by making a dough or paste of the carrier and compound, and crushing and drying to obtain the desired granular particle size.
Dusts containing the compounds are prepared simply by intimately mixing the compound in powdered form with a suitable dusty agricultural carrier, such as kaolin clay, ground volcanic rock and the like. Dusts can suitably contain from about 1% to about 10% of the compound.
It is equally practical, when desirable for any reason, to apply the compound in the form of a solution in an appropriate organic solvent, usually a bland petroleum oil, such as the spray oils, which are widely used in agricultural chemistry.
Insecticides and miticides are generally applied in the form of a dispersion of the active ingredient in a liquid carrier. It is conventional to refer to application rates in terms of the concentration of active ingredient in the carrier. The most widely used carrier is water.
The compounds of the invention can also be applied in the form of an aerosol composition. In such compositions the active compound is dissolved or dispersed in an inert carrier, which is a pressure-generating propellant mixture. The aerosol composition is packaged in a container from which the mixture is dispensed through an atomizing valve. Propellant mixtures comprise either low-boiling halocarbons, which may be mixed with organic solvents, or aqueous suspensions pressurized with inert gases or gaseous hydrocarbons.
The actual amount of compound to be applied to loci of insects and mites is not critical and can readily be determined by those skilled in the art in view of the examples above. In general, concentrations of from 10 ppm to 5000 ppm of compound are expected to provide good control. With many of the compounds, concentrations of from 100 to 1500 ppm will suffice. For field crops, such as soybeans and cotton, a suitable application rate for the compounds is about 0.5 to 1.5 lb/A, typically applied in 50 gal/A of spray formulation containing 1200 to 3600 ppm of compound. For citrus crops, a suitable application rate is from about 100 to 1500 gal/A spray formulation, which is a rate of 100 to 1000 ppm.
The locus to which a compound is applied can be any locus inhabited by an insect or arachnid, for example, vegetable crops, fruit and nut trees, grape vines, and ornamental plants. Inasmuch as many mite species are specific to a particular host, the foregoing list of mite species provides exemplification of the wide range of settings in which the present compounds can be used.
Because of the unique ability of mite eggs to resist toxicant action, repeated applications may be desirable to control newly emerged larvae, as is true of other known acaricides.
The following formulations of compounds of the invention are typical of compositions useful in the practice of the present invention.
A. 0.75 Emulsifiable Concentrate
______________________________________Compound of Example 25 9.38%"TOXIMUL D" 2.50%(nonionic/anionic surfactant blend)"TOXIMUL H" 2.50%(nonionic/anionic surfactant blend)"EXXON 200" 85.62%(naphthalenic solvent)______________________________________
B. 1.5 Emulsifiable Concentrate
______________________________________Compound of Example 25 18.50%"TOXIMUL D" 2.50%"TOXIMUL H" 2.50%"EXXON 200" 76.50%______________________________________
C. 0.75 Emulsifiable Concentrate
______________________________________Compound of Example 41 9.38%"TOXIMUL D" 2.50%"TOXIMUL H" 2.50%"EXXON 200" 85.62%______________________________________
D. 1.0 Emulsifiable Concentrate
______________________________________Compound of Example 41 12.50%N-methylpyrrolidone 25.00%"TOXIMUL D" 2.50%"TOXIMUL H" 2.50%"EXXON 200" 57.50%______________________________________
E. 1.0 Aqueous Suspension
______________________________________Compound of Example 25 12.00%"PLURONIC P-103" 1.50%(block copolymer of propylene oxideand ethylene oxide, surfactant)"PROXEL GXL" .05%(biocide/preservative)"AF-100" .20%(silicon based antifoam agent)"REAX 88B" 1.00%(lignosulfonate dispersing agent)propylene glycol 10.00%veegum .75%xanthan .25%water 74.25%______________________________________
F. 1.0 Aqueous Suspension
______________________________________Compound of Example 25 12.50%"MAKON 10" (10 moles ethyleneoxide 1.00%nonylphenol surfactant)"ZEOSYL 200" (silica) 1.00%"AF-100" 0.20%"AGRIWET FR" (surfactant) 3.00%2% xanthan hydrate 10.00%water 72.30%______________________________________
G. 1.0 Aqueous Suspension
______________________________________Compound of Example 41 12.50%"MAKON 10" 1.50%"ZEOSYL 200" (silica) 1.00%"AF-100" 0.20%"POLYFON H" 0.20%(lignosulfonate dispersing agent)2% xanthan hydrate 10.00%water 74.60%______________________________________
H. Wettable Powder
______________________________________Compound of Example 25 25.80%"POLYFON H" 3.50%"SELLOGEN HR" 5.00%"STEPANOL ME DRY" 1.00%gum arabic 0.50%"HISIL 233" 2.50%Barden clay 61.70%______________________________________
I. Aqueous Suspension
______________________________________Compound of Example 25 12.40%"TERGITOL 158-7" 5.00%"ZEOSYL 200" 1.00%"AF-100" 0.20%"POLYFON H" 0.50%2% xanthan solution 10.00%tap water 70.90%______________________________________
J. Emulsifiable Concentrate
______________________________________Compound of Example 25 12.40%"TOXIMUL D" 2.50%"TOXIMUL H" 2.50%"EXXON 200" 82.60%______________________________________
K. Wettable Powder
______________________________________Compound of Example 41 25.80%"SELLOGEN HR" 5.00%"POLYFON H" 4.00%"STEPANOL ME DRY" 2.00%"HISIL 233" 3.00%Barden clay 60.20%______________________________________
L. Emulsifiable Concentrate
______________________________________Compound of Example 25 6.19%"TOXIMUL H" 3.60%"TOXIMUL D" 0.40%"EXXON 200" 89.81%______________________________________
M. Wettable Powder
______________________________________Compound of Example 25 25.80%"SELLOGEN HR" 5.00%"POLYFON H" 4.00%"STEPANOL ME DRY" 2.00%"HISIL 233" 3.00%Barden clay 60.20%______________________________________
N. Aqueous Suspension
______________________________________Compound of Example 41 12.40%"TERGITOL 158-7" 5.00%"ZEOSYL 200" 1.00%"POLYFON H" 0.50%"AF-100" 0.20%xanthan solution (2%) 10.00%tap water 70.90%______________________________________ | 4-substituted-pyrido[3,2-d]pyridmidine, -pyrido[4,3-d]pyrimidine, -pyrido[3,4-d]pyrimidine, pyrido[2,3-d]pyrimidine, -pteridine, -pyrimido[4,5-d]pyrimidine, -pyrimido[4,5-c]pyridazine, -pyrimido[5,4-d]pyrimidine, -pyrimido[5,4-c]pyridazine, pyrimido[4,5-d]pyridazine, and pyrimido[5,4-e]-1,2,4-triazine derivatives, for example 4-[2-(4-chlorophenyl)ethoxy]pyrido[2,3-d]pyrimidine, are useful as fungicides, inseciticides and miticides. | 2 |
TECHNICAL FIELD
The invention relates to magnetic tunnel junction magnetoresistive devices, and more particularly, to a magnetic random access memory that employs such devices.
BACKGROUND
A magnetic tunnel junction (MTJ) forms the basic memory element of a non-volatile magnetic random access memory (MRAM) that promises high performance and endurance, and moreover has the potential to be scaled to extremely small sizes. A magnetic tunnel junction (MTJ) is composed of a sandwich of two magnetic layers separated by an ultra-thin insulating layer. One of these layers forms the memory or storage layer, and the other layer forms a reference layer whose magnetic structure is not changed during operation of the MRAM. Electrical current that tunnels between the reference and memory magnetic layers is spin-polarized: The magnitude of the spin-polarization is determined by a combination of the electronic properties of the magnetic electrodes and “spin-filtering” properties of the tunnel barrier. (These magnetic layers are in contact with electrodes; alternatively, these magnetic layers may be viewed as forming part of the electrodes themselves.)
In current-day MRAM the magnetic state of the MTJ is changed by passing a current through it. The current, which is innately spin-polarized, delivers spin angular momentum, so that once a threshold current is exceeded the direction of the memory layer moment is switched. The magnitude of the switching current that is required is less when the magnetization of the electrodes is oriented perpendicular to the layers.
The most promising materials that are being explored for MTJs for dense MRAM include ferromagnetic electrodes formed from alloys of Co, Fe and B, and tunnel barriers formed from MgO (see, for example, U.S. Pat. No. 7,598,555 titled “MgO tunnel barriers and method of formation”). The ferromagnetic electrodes are made of layers sufficiently thin that the magnetizations of these electrodes are oriented perpendicular to these layers. The perpendicular magnetic anisotropy (PMA) of Co—Fe—B layers arises from the interfaces between these layers and the tunnel barrier and/or the underlayer on which the Co—Fe—B layer is deposited. Thus, these layers must be made sufficiently thin that the interface PMA overcomes the demagnetization energy that arises from the magnetic volume and increases in proportion with the magnetic volume of the Co—Fe—B layer. In practice, this means that the PMA is too weak to overcome thermal fluctuations when the device has a critical dimension less than ˜20 nm in size, since the thickness of the magnetic layer has to be (i) below that required to maintain its moment perpendicular and (ii) below that needed to switch the magnetic layer with reasonable current densities.
SUMMARY
Materials for use as ferromagnetic electrodes are disclosed which display much larger PMA than that exhibited by Co—Fe—B, with the PMA arising from the volume rather than the interfaces of the electrodes. These compounds, known as Heusler alloys 1 , are compounds having the chemical formula X 2 YZ or X′X″YZ, wherein X and X′ and X″ and Y are transition metals or lanthanides (rare-earth metals) and Z is from a main group metal. The Heusler compounds have a structure of the type Cu 2 MnAl (defined in the Pearson Table), in which the elements are disposed on 4 interpenetrating face-centered cubic (fcc) lattices. Many compounds (˜800) are known in this family 2 . Some of these compounds are ferromagnetic or ferrimagnetic due to magnetic moments on the X and/or Y sites. Moreover, while the parent Heusler compounds are cubic and exhibit weak or no significant magnetic anisotropy, the structure of some of these compounds is found to be tetragonally distorted: Due to this distortion the magnetization exhibited by these compounds may be aligned along the tetragonal axis. Thus, thin films formed from such materials may exhibit PMA due to a magneto-crystalline anisotropy associated with the tetragonally distorted structure. Some examples of such tetragonal Heusler compounds are Mn 3-x Ga and Mn 3-x Ge. Thin films of these materials exhibit large PMA but, to date, all work on these materials has involved films that are grown epitaxially on single crystalline substrates such as MgO(100) using seed layers formed from a variety of materials but preferably Cr or Pt 3 . Such single crystalline substrates are not useful for MRAM applications in which the MTJs must be deposited on wires formed from polycrystalline copper, which may be covered with other layers that are also polycrystalline or amorphous.
A preferred embodiment of the invention is a device that includes a tetragonal Heusler of the form Mn 1+c X, in which X includes an element selected from the group consisting of Ge and Ga, with 0≦c≦3. The device also includes a substrate oriented in the direction (001) and of the form YMn 1+d , in which Y includes an element selected from the group consisting of Ir and Pt, with 0≦d≦4. The tetragonal Heusler and the substrate are in proximity with each other, thereby allowing spin-polarized current to pass from one through the other. In a more preferred embodiment X is Ge, Y is Ir, the tetragonal Heusler is of the form Mn 3 Ge, and the substrate is of the form IrMn 3 . The magnetization of the Heusler compound is preferably oriented perpendicular to the film plane and has a thickness of between 10 and 500 angstroms.
Another preferred embodiment of the invention is a device that includes a first electrode, a magnetic free layer in contact with the first electrode, a tunnel barrier underlying the free magnetic layer, and a magnetic reference layer underlying the tunnel barrier, in which the magnetic reference layer includes a tetragonal Heusler of the form Mn 1+c X, X includes an element selected from the group consisting of Ge and Ga, and 0≦c≦3. The device also includes a second electrode underlying the magnetic reference layer, with the second electrode including a substrate oriented in the direction (001) and of the form YMn 1+d , in which Y includes an element selected from the group consisting of Ir and Pt, and 0≦d≦4. Current that passes through the first electrode and the second electrode passes through the magnetic free layer, the tunnel barrier, and the magnetic reference layer.
One implementation of the invention is a method of using the device just described, in which voltage is applied across the first electrode and the second electrode, thereby inducing current to flow through the magnetic layers and the tunnel barrier. As a result, the orientation of the free magnetic layer may be changed due to spin transfer torque from the current. The device may be one of a plurality of magnetic tunnel junction devices that together form an MRAM, with each of the tunnel junction devices including a free layer having a respective orientation. Information may be read out of the MRAM by detecting the orientation of the free layers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 (which includes FIGS. 1A and 1B ). Mn 3 Ge Heusler films: structural and topographical properties
FIG. 1A X-ray diffraction θ-2θ patterns of 300 Å thick Mn 3 Ge films deposited at various temperatures on Si(001)/SiO 2 substrates on which were first deposited TaN/IrMn 3 films. The Mn 3 Ge layers were capped with 30 Å thick Ta layers. For comparison the upper two curves correspond to data taken on films that were: (i) deposited at room temperature (RT) followed by an in-situ anneal and (ii) prepared using a 3-step process. Data for these samples are also included in FIG. 1B .
FIG. 1B Deposition temperature dependence of (top-panel) crystal structure ordering (extrapolated from FIG. 1A ) and (bottom-panel) root mean square (RMS) surface roughness measured by atomic force microscopy (AFM). The top panel shows the ratio of the measured intensities of the Mn 3 Ge (002) to the Mn 3 Ge (004) peaks for three different deposition methods.
FIG. 2 (which includes FIGS. 2A, 2B, 2C, and 2D ). High-resolution transmission electron microscopy (HRTEM) image and electron energy loss spectroscopy (EELS) for Mn 3 Ge films, with and without TaN diffusion barriers HRTEM images of films with the structure: ( FIG. 2A ) Si/250 Å SiO 2 /200 Å TaN/200 Å IrMn 3 /300 Å Mn 3 Ge (RT+450C Anneal)/30 Å Ta, and ( FIG. 2C ) Si/250 Å SiO 2 /200 Å TaN/200 Å IrMn 3 /20 Å TaN/300 Å Mn 3 Ge (3-steps process)/20 Å rf-MgO/12 Å Co 20 Fe 60 B 20 /50 Å Ta/50 Å Ru. EELS data are shown in FIG. 2B and FIG. 2D , which were taken for the samples in FIG. 2A and FIG. 2C , respectively. (In each case, the data were collected over the region indicated by the box in the image and in the direction indicated by the arrow within that box.) Data are shown for the concentration of Ta, N, Mn, Ir, and Ge versus the thickness of the film. These data show clear differences for Ir and Ge interdiffusion. No sign of interdiffusion was found when a TaN diffusion barrier was deposited between the IrMn 3 and Mn 3 Ge layers.
FIG. 3 (which includes FIGS. 3A, 3B, 3C, and 3D ). Mn 3 Ge Heusler films with giant perpendicular magnetic anisotropy
FIG. 3A Magnetization versus magnetic field hysteresis loops of Mn 3 Ge films grown on different underlayers/substrates. Open squares pertain to measurements with applied magnetic field aligned parallel to the film plane. The top four panels refer to samples with the following structures: Si(001)/SiO 2 /200 Å TaN/200 Å IrMn 3 /10 Å TaN/xÅ Mn 3 Ge (3-step)/30 Å Ta, with x=50 Å, 70 Å, 100 Å and 300 Å. Solid lines denote out-of-plane loops. The bottom-left panel refers to Mn 3 Ge film grown without a 10 Å TaN diffusion barrier, while the bottom-right panel refers to Mn 3 Ge film deposited on a MgO/Cr-buffered MgO(001) single crystal substrate. Measurements are carried out at ambient temperature. FIG. 3C Top panel—magnetic moment per unit area m extrapolated from the data in FIG. 3A . The solid line indicates the predicted bulk areal moment of D0 22 -Mn 3 Ge. Bottom panel—coercive field H C (left axis, full triangles) and uniaxial anisotropy constant K U (right axis, empty squares). In order to determine the uniaxial anisotropy constant from the relation K U =H eff ·M S /2+2πM S 2 , H eff is usually evaluated from the M vs. H hard-axis loop at the magnetic field at which the magnetization reaches saturation. As is noticeable in FIG. 3A (open squares), the magnetization is expected to saturate at high magnetic fields values, not accessible by the measurement tool; thus, H eff was assumed (as a lower bound) to be 7T.
FIGS. 3B and 3D Schematic diagrams of the nominal structure of films grown on a Si(001)/SiO 2 substrate ( FIG. 3B ) and a MgO(001) single crystal substrate ( FIG. 3D ). To investigate the structure, topography, and magnetic properties of these films, 30 Å Ta (not shown in the figures) was used in each case as a capping layer.
FIG. 4 (which includes FIGS. 4A, 4B, 4C, and 4D ). Characteristics of Mn 3 Ge-based magnetic tunnel junction
FIG. 4A MgO thickness dependence of R AP A product (solid symbols) and TMR (open symbols). Si/SiO 2 /TaN/IrMn 3 , Si/SiO 2 /TaN/IrMn 3 /TaN, MgO(100)/Cr seed layers are compared. Solid line and dashed lines are guides to the eye for R AP A product and TMR, respectively.
FIG. 4B HRTEM image of a Mn 3 Ge-based device with ˜27 nm junction size, patterned by e-beam lithography.
FIG. 4C 2-terminal junction resistance versus magnetic field applied perpendicular to the device measured at 300K (smaller squares) and 3K (bigger squares). TMR of junctions with (solid squares) and without (open squares) TaN diffusion barrier are compared. For MTJs with TaN diffusion barriers, two sets of data were measured at 3K (solid bigger squares) after cooling down the device from 300 K in a field of +9T and a field of −9T, respectively. These data are mirror images of each other, as can be seen in the figure.
FIG. 4D Temperature dependence of R P and R AP (bottom panel) and TMR (top panel) for TaN/IrMn 3 and TaN/IrMn 3 /TaN.
DETAILED DESCRIPTION
Films of the Heusler compound Mn 3-x Ge, along with other layers, were grown over Si(100) substrates covered with 250 Å of amorphous SiO 2 , by ion-beam deposition (IBD) or by dc-magnetron sputtering in an ultra-high vacuum (UHV) chamber with a base pressure of ˜2×10 −9 Torr. For MTJs for MRAM applications, the magnetization of the film should exhibit a well-defined magnetization versus perpendicular magnetic field hysteresis loop which is square (remanent magnetization is equal to or nearly equal to the saturation magnetization of the film in large magnetic fields), in which the magnetization switches abruptly from one direction perpendicular to the film plane to the opposite direction at a well-defined coercive field (the field where the magnetization of the film is zero). Also, when the magnetic field is applied in a direction in the plane of the film, the magnetization in the direction of the applied field should increase from approximately zero to the value of the saturation magnetization approximately linearly. When films of Mn 3-x Ge are directly deposited on a surface of amorphous SiO 2 , the films are found to exhibit no well-defined crystalline texture and, for this reason, the magnetization of the films is not well oriented perpendicular to the film plane so that the magnetization versus perpendicular applied magnetic field is not square as required for optimum performance.
For some materials even highly textured films can be formed by depositing these materials on appropriate underlayers that are properly prepared. For example, typically fcc materials such as Cu or Pt will preferentially be textured with (111) crystal planes parallel to the surface of the film, whereas body centered cubic materials will tend to grow with (110) crystal planes parallel to the surface of the film. However, such metals as Cu and Pt grown on oxide surfaces are often very rough because these metals may not “wet” the oxide surface. Thus, to minimize their surface energy they may grow initially in the form of disconnected islands that may eventually coalesce to form a continuous thin film when the film is made sufficiently thick.
In a preferred embodiment of the invention, highly textured (001) oriented films of Mn 1+c Ge or Mn 1+c Ga, in which for each case 0≦c≦3 (or in the case of the Ge compound, 1≦c≦3 is even more preferred) are prepared by using underlayers that are themselves highly textured when deposited on an amorphous layer of SiO 2 . Underlayers that have this property include TaN/IrMn 3 and TaN/IrMn 3 /TaN. IrMn 3 films that are deposited on TaN seed layers on amorphous SiO 2 are highly textured with the (001) axis perpendicular to the plane of the IrMn 3 film. (Similar results would be expected using Pt instead of Ir.) Without the TaN seed layer, the IrMn 3 layers are poorly textured with grains in the film that are oriented with (111) planes or (001) or (110) planes parallel to the substrate. The (001) orientation of the grains within the polycrystalline IrMn 3 layer is needed to promote the growth of (001) oriented Mn 3 Ge layers, in which the tetragonal axis is perpendicular to the plane of the Mn 3 Ge layer. Although the lattice mismatch between IrMn 3 and Mn 3 Ge is small (<1%), these same underlayers of TaN/IrMn 3 (and equivalently TaN/IrMn 3 /TaN) are found to promote the growth of a wide range of both cubic and tetragonal Heuslers that have larger lattice mismatches. (Even lattice mismatch as high as ˜7% is estimated by assuming epitaxial 45° in-plane rotated growth of Heusler compound on IrMn 3 , i.e., <110> Heusler //<100> IrMn3 in L2 1 unit cell for Heusler and L1 2 unit cell for IrMn 3 .) These compounds include Co 2 MnSi, Co 2 MnGe, Ni 2 MnGe, Fe 2 CuSn, Fe 2 CuSb, Mn 3 Ga, Mn 2 NiSb, Mn 2 CuSb Co 2 RhSb, and Rh 2 CoSb. Thin films of these Heusler compounds were grown on TaN/IrMn 3 and TaN/IrMn 3 /TaN underlayers and were found, in each case, to exhibit well defined (001) crystallographic textures due to the properties of the underlayers.
Data of an example of the structure that realizes a highly textured Mn 3 Ge film are shown in FIG. 1 . Seed layers of TaN that are 200 Å thick are first deposited on a Si(100)/SiO 2 substrate by reactive dc magnetron sputtering at ambient temperature. IrMn 3 underlayers that are 100 Å-200 Å thick are subsequently deposited at ambient temperature by dc-magnetron sputtering. These layers may also be deposited by ion-beam deposition (IBD). For magnetron sputtering a sputter gas pressure of 3 mTorr was used; TaN was grown using a sputter gas mixture of argon and nitrogen. The composition of the TaN film, i.e., Ta 1-x N x , was sensitive to the composition of the sputter gas: A preferred composition of 90% Ar and 10% N2 (by flow of gas into the chamber) was used to obtain films with a composition close to Ta 50 N 50 .
A series of studies was carried out to determine optimal conditions for preparing films composed of the Mn 3 Ge compound, as shown in FIG. 1A . (Data analogous to those shown in FIG. 1A were recorded for Mn 2 Ga, which are not shown, but which were similar in appearance.) In one set of experiments, Mn 3 Ge films, each 300 Å thick, were deposited on Si(100)/SiO 2 /200 Å TaN/200 Å IrMn 3 at seven different deposition temperatures (T D or T growth ), which varied from room temperature (RT) to 550° C. but without a subsequent annealing step (see the bottom seven curves in FIG. 1A ). The roughness of these films depends on T D (see the curves in FIG. 1B labeled “no anneal”). Rough films (root mean square (RMS) roughness >5 Å) were obtained for T D greater than 200° C., with the RMS roughness increasing monotonically with increasing T D . For use as magnetic electrodes in MTJs for MRAM applications, the tunnel barriers are preferably very thin in the range of ˜1-2 nm, and consequently, the magnetic electrodes are ideally very smooth. At the same time, for optimal magnetic properties of the Heusler compound, the Mn and Ge atoms must be well-ordered atomically on the respective atomic sites in the unit cell of the Heusler compound. To obtain smooth films, T D must be kept as low as possible but to achieve chemically ordered Heusler compounds T D must be maintained preferably as high as possible. At the same time there is a limitation on the maximum value of T D which is determined by the temperature above which diffusion of elements from the underlayers into the Mn 3 Ge layer becomes significant. A second, alternative method of forming the Mn 3 Ge layer involves depositing the layer at ambient temperature or a sufficiently low deposition temperature (e.g., <200° C.) and then subsequently annealing the structure at an elevated temperature (see the curve in FIG. 1A labeled “RT+anneal”).
A third method combines aspects of these two methods in which the Mn 3 Ge films are grown using a 3-step process (see the curve in FIG. 1A labeled “3 steps”). First, a seed layer formed from Mn 3 Ge is grown at a high temperature, for example, a layer 20 Å thick is deposited at 450° C. Second, a Mn 3 Ge layer is deposited at a lower temperature. The thickness of the combination of the seed layer and the second Mn 3 Ge layer equals the desired thickness. For example, a layer formed from 280 Å Mn 3 Ge is deposited at 150° C. Third, the deposited structure is annealed in-situ: for example, at 450° C. for 1 hour in the deposition chamber in ultra-high vacuum. The films grown by this 3-step process had significantly lower RMS roughness (˜3 Å) while having chemical ordering comparable to the films grown directly at 450° C. (As indicated in FIG. 1B , the chemical ordering between the MnMn and MnGe planes in a D0 22 -Mn 3 Ge structure is directly correlated with the intensity ratio of the x-ray diffraction peaks I(002)/I(004); Mn 3 Ge and higher chemical ordering implies improved magnetic properties, such as higher spin polarization of electrons flowing through the Mn 3 Ge electrode.) This is shown in FIG. 1B , which compares RMS roughness of the three methods just described.
During the annealing step, there may be substantial interdiffusion between the IrMn 3 and Mn 3 Ge layers, as shown in FIG. 2 . This may result in deterioration of the magnetic properties of the Mn 3 Ge layer. For example, the magnetic moment of the Mn 3 Ge film may be substantially reduced. Using the conditions mentioned above, Mn 3 Ge films with thicknesses of up to ˜100 Å display almost zero magnetic moment. To reduce the interdiffusion of elements between the underlayers and the Mn 3 Ge layer and the consequent degradation of properties of the Mn 3 Ge layers, a thin TaN layer may be deposited on top of the IrMn 3 layer before the Mn 3 Ge layer is deposited. A TaN layer as thin as 20 Å or even 10 Å is sufficient to considerably limit interdiffusion. Electron energy loss spectroscopy (EELS) studies carried out in a transmission electron microscope on cross-sectional samples of TaN/IrMn 3 /Mn 3 Ge (see FIG. 2B ) and TaN/IrMn 3 /TaN/Mn 3 Ge (see FIG. 2D ) thin film structures show that, in the first case, there is substantial diffusion of Ir into the Mn 3 Ge layer whereas in the second case, there is no evidence of Ir diffusion into the Mn 3 Ge layer (see FIGS. 2B and 2D ). FIGS. 2A and 2C are high resolution cross sectional TEM images of the structures corresponding to the data shown in FIGS. 2B and 2D , respectively.
The magnetic properties of samples of TaN/IrMn 3 /Mn 3 Ge and TaN/IrMn 3 /TaN/Mn 3 Ge are compared in FIG. 3 for several thicknesses of the Mn 3 Ge layers. FIG. 3A shows in-plane (open squares) and out-of-plane (solid line) magnetic hysteresis loops measured using a SQUID-VSM for Mn 3 Ge films grown on Si(001)/SiO 2 substrates, with and without 20 Å of TaN. Mn 3 Ge films deposited on the TaN diffusion barrier show a magnetization that increases with film thickness. The bottom-right panel in FIG. 3A corresponds to the lower part of the full MTJ structure shown in FIG. 3D without the upper free layer structure above Mn 3 Ge (i.e., instead of MgO/CoFeB/Ta/Ru, a 30 Å Ta capping layer was deposited on Mn 3 Ge), whereas the other five panels in FIG. 3A correspond to the lower part of structure shown in FIG. 3B (once again, instead of MgO/CoFeB/Ta/Ru, a 30 Å Ta capping layer was deposited on Mn 3 Ge). In FIG. 3B , which shows a preferred embodiment of the present invention, Ta/Ru could form part of a top electrode, and TaN/IrMn 3 could form part of a bottom electrode. The magnetic free layer and the magnetic reference layer are represented by the structures CoFeB and Mn 3 Ge, respectively, whereas the tunnel barrier is MgO. The additional layer of TaN below the magnetic reference layer Mn 3 Ge is an optional diffusion barrier. In an MRAM device, the orientations of the free layers in an array of MTJ structures (e.g., see the exemplary structure of FIG. 3B ) represents data (information) that may be written into the MTJ structures and/or read out of them (by detecting the orientations of the free layers).
Magnetic hysteresis loops of 300 Å thick Mn 3 Ge film grown on MgO/Cr-buffered MgO(001) single crystal substrate are illustrated in the right-bottom panel of FIG. 3A ; this film was grown in order to compare the quality between Mn 3 Ge films grown onto amorphous and single crystal substrates. All Mn 3 Ge films display very strong PMA, although the anisotropy is substantially lower when they are grown on MgO/Cr-buffered single crystal MgO(001), presumably due to the lattice mismatch between Cr and the Heusler alloy. In contrast, the IrMn 3 buffer-layer allows a ‘strain-free’ growth of Mn 3 Ge, giving rise to a giant PMA, with values of coercive fields H C up to 6T, as shown with the full triangles in the bottom panel of FIG. 3C (for a TaN/IrMn 3 /TaN/Mn 3 Ge structure). Magnetic moment per unit area m as a function of Mn 3 Ge thickness is estimated from the magnetization vs. field loops and illustrated in the top panel of FIG. 3C . Here, the solid straight line refers to the calculated value of bulk D0 22 -Mn 3 Ge: The experimental values for Mn 3 Ge films grown on Si/SiO 2 substrates with the TaN diffusion barrier (top panel of FIG. 3C , circles connected by dashed line) follow the theoretical trend; however, compared to these values, m is only ˜80% and ˜65% of the theoretical value for films without the TaN barrier and those grown on MgO(001) single crystal substrates (see also top panel of FIG. 3C ). Even in the case of Mn 2 Ga, large PMA values were observed using a TaN/IrMn 3 /Mn 2 Ga structure.
The uniaxial anisotropy constant K U is shown in the bottom panel of FIG. 3C (empty squares) as a function of Mn 3 Ge thickness. K U monotonically increases by depositing thicker films onto the TaN diffusion barrier, which is due to the increase of magnetization with the Mn 3 Ge thickness. K U was estimated from the relation K U =H eff ·M S /2+2πM S 2 (H eff being the effective magnetic field and M S the saturation magnetization), in which the first term stands for the effective magnetic anisotropy, and the second one relates to the shape anisotropy arising from the sample's lateral dimensions (note that H eff =7T was considered as lower bound—see the description of FIG. 3C in the Brief Description of the Figures).
MTJ devices were fabricated using standard lithographic techniques from films whose structure was Si/250 Å SiO 2 /200 Å TaN/200 Å IrMn 3 /10-20 Å TaN/300 Å Mn 3 Ge (3-step process)/8-28 Å rf-MgO/10-15 Å CoFeB/50 Å Ta/50 Å Ru. Before patterning, these films were post-annealed at 350° C. for 60 minutes in a high-vacuum chamber with an applied magnetic field of 1T directed out of the plane of the samples. Devices with sizes of 1×2 μm 2 and ˜30 nm in diameter were fabricated by optical lithography and e-beam lithography, respectively. Only the free layer was patterned to define the junction size—the reference layer was not patterned. The reference layer was formed from the Mn 3 Ge Heusler compound, and the free layer was formed from an ultrathin layer of CoFeB with a composition of 20:60:20.
FIG. 4C shows the tunnel magnetoresistance (TMR) of the patterned MTJ devices versus applied perpendicular magnetic field measured at 300 K (smaller squares) and 3K (larger squares) for a 1×2 μm 2 MTJ device with a TaN diffusion barrier (solid squares; the MgO barrier was 25 Å thick) and without a TaN diffusion barrier (open squares; the MgO barrier was 27 Å thick). At both these temperatures very high applied magnetic fields (±9 T) are needed to align the moments of the Heusler and CoFeB layers parallel to each other (P state) because of the giant uniaxial anisotropy of the Mn 3 Ge reference layer. In the P state the junction resistance is high and switches to a low resistance close to zero field when the CoFeB free layer moment switches its direction to be in the anti-parallel configuration (AP state). Thus the tunneling magnetoresistance (TMR) determined using the formula [(R P −R AP )/R AP ]×100 is negative with values of ˜−35% at 300 K and ˜−74% at 3K (R P and R AP being the junction resistances in the P and AP states, respectively). This negative TMR is indicative of negative spin polarization of the Mn 3 Ge layer. This is the highest reported TMR to date obtained from perpendicularly-magnetized magnetic tunnel junction with a tetragonal Heusler alloy.
For the same device, the TMR ( FIG. 4D , top panel) and the resistances in the P and AP states ( FIG. 4D , bottom panel) were measured while cooling the device from 300 K to 3K. R AP barely changed, while R P increased monotonically as T decreased, resulting in higher TMR at low temperatures (see the bottom panel of FIG. 4D ).
The dependence of the resistance-area product R AP A (solid symbols) and TMR (open symbols) of MTJs on the tunnel barrier thickness measured at RT is averaged over >20 devices and summarized in FIG. 4A . (Note that the TMR values in FIG. 4A are smaller than those shown in FIG. 4C : In FIG. 4A , for fast evaluation of the TMR, R AP and R P values were respectively measured at +0.3T and −0.3T, instead of sweeping the magnetic field over the range ±9T.) R AP A increases exponentially with barrier thickness (A=area of device).
A cross-sectional high-resolution transmission electron microscopy (HRTEM) image of a device with the structure Si/250 Å SiO 2 /200 Å TaN/200 Å IrMn 3 /300 Å Mn 3 Ge (3-step process)/15 Å rf-MgO/15 Å Co 20 Fe 60 B 20 /50 Å Ta/50 Å Ru pattered by e-beam lithography is illustrated in FIG. 4B . The multilayered stack was etched by Ar milling down to the MgO tunnel barrier, giving the CoFeB free layer the desired size (here the device width is ˜27 nm); after that, the lateral sides of the junction were filled with Al 2 O 3 (bright and amorphous layer in the image) to isolate the junction from the top 50 Å Ru/650 Å Au contact, deposited in-situ by IBD.
Although the preferred materials for the underlayers that favor (001) textured Heusler thin films are TaN/IrMn 3 and TaN/IrMn 3 /TaN, TaN may be substituted with other metallic nitrides that give rise to smooth surfaces. These include NbN (lattice constant a=4.36 Å), TiN (a=4.24 Å) and ScN (a=4.50 Å). IrMn 3 may be replaced with other similar materials that have the same structure as the AuCu 3 family of compounds. These include especially Mn-based compounds that include Mn 3 Rh (a=3.81 Å) and Mn 3 Os, which are particularly suitable for the growth of Mn based Heuslers including Mn 3 Ge and Mn 3 Ga. Other materials that may replace IrMn 3 include: AuCu 3 (a=3.74 Å), Ag 3 Pt (a=3.88 Å), Mn 3 Pt (a=3.87 Å), Fe 3 Pt (a=3.73 Å), FePt 3 (a=3.87 Å), HfIr 3 (a=3.93 Å).
Note that the elemental composition of the underlayers and Heusler compounds is the nominal composition. This was measured by Rutherford backscattering (RBS) which is accurate to approximately ±1 atomic percent. The properties of the Heusler compounds are typically sensitive to the elemental composition, as well as the chemical ordering of the constituent elements and any impurities. For the IrMn 3 underlayer, the composition can be varied over a wide atomic range but preferably the ratio of Ir:Mn is within ±10% of the nominal ratio 1:3 or, less preferably, ±20% of the nominal ratio 1:3.
The preferred compositions disclosed herein are ideally pure with little or no impurities. In practice, however, deviations from the ideal case may be tolerated. The level of impurities is preferably less than 1 atomic percent, although an impurity level of up to 10 atomic percent may be tolerated.
REFERENCES
1. Felser, C., Fecher, G. H. & Balke, B. Spintronics: A Challenge for Materials Science and Solid-State Chemistry. Angew. Chem. Int. Ed. 46, 668-699, (2007).
2 . Pearson's Handbook of Crystallographic Data for Intermetallic Phases. 2nd edn, (2009).
3. Li, M., Jiang, X., Samant, M. G., Felser, C. & Parkin, S. S. P. Strong dependence of the tetragonal Mn 2.1 Ga thin film crystallization temperature window on seed layer. Appl. Phys. Lett. 103, 032410, (2013). | A structure includes a tetragonal Heusler of the form Mn 1+c X, in which X includes an element selected from the group consisting of Ge and Ga, with 0≦c≦3. The tetragonal Heusler is grown directly on (or more generally, over) a substrate oriented in the direction (001) and of the form YMn 1+d , wherein Y includes an element selected from the group consisting of Ir and Pt, with 0≦d≦4. The tetragonal Heusler and the substrate are in proximity with each other, thereby allowing spin-polarized current to pass from one through the other. This structure may form part of a magnetic tunnel junction magnetoresistive device, and an array of such magnetoresistive devices may together form an MRAM. | 7 |
RELATED U.S. PATENT APPLICATION DATA
[0001] This patent application claims priority from U.S. provisional patent application No. 61/294,130, filed Jan. 12, 2010.
FIELD OF THE INVENTION
[0002] The present invention relates to a modified feeding utensil comprising a feeding utensil component and a receptacle component. The receptacle component is either permanently or detachably positioned below the feeding utensil component to avoid spills.
BACKGROUND
[0003] A young child may need assistance in feeding such that a caretaker offers food on a utensil to be consumed by the child. Frequently some of the offered food does not reach the mouth of the child, but is spilled. The present invention provides a modified feeding utensil which minimizes the amount of spillage when feeding the child.
SUMMARY OF THE INVENTION
[0004] In one aspect, the invention provides a modified feeding utensil. The modified feeding utensil comprises a feeding utensil component, a receptacle component for collecting food that spills from the feeding utensil component positioned below the feeding utensil component, and a positioning component connecting the feeding utensil component to the receptacle component. The receptacle component comprises a bottom surface and one or more sides,
[0005] The feeding utensil component may be a spoon, fork or the spout of a bottle. The receptacle component comprises a bottom surface and one or more sides. The bottom surface may have the shape of an oval or circle with upright or sloping sides. The bottom surface may have the shape of a triangle, square, rectangle, trapezoid, pentagon, hexagon, heptagon, octagon with one or more upright sides or with one or more sloping sides. The positioning component comprises one or more rods or straps which connects the feeding utensil component to the receptacle component. The positioning component allows for permanent or detachable positioning of the receptacle component below the feeding utensil component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 illustrates a side view of a modified spoon with an oval-shaped receptacle bottom surface.
DETAILED DESCRIPTION OF THE INVENTION
[0007] The present invention discloses a modified feeding utensil which minimizes the amount of food (solid or liquid) spillage while feeding an individual (child or adult). The modified feeding utensil comprises a feeding utensil component, a receptacle component for collecting solids or liquids that spill from the feeding utensil component positioned below the feeding utensil component and a positioning component. The positioning component connects the feeding utensil component to the receptacle component.
[0008] The feeding utensil component may comprise a fork or spoon or a spout for the transfer of liquid from a bottle. The receptacle component comprises a bottom surface with one or more sides. The bottom surface may be of any shape. As an illustration, the receptacle component bottom may be a circle or oval shape with an upright or sloping side. The receptacle component bottom may take on other geometric shapes, for example, a triangle, square, rectangle, trapezoid, pentagon, hexagon, heptagon, octagon, nonagon, decagon, undecagon, dodecagon and on and on. These receptacle components may have one or more upright sides or one or more sloping sides. For example, for a square bottom shape 3 of the sides may be upright but the fourth one closest to the neck of an individual may be sloping, When the sides are sloping sides, the sides are angled so that spills slide down the sides to the bottom of the receptacle component.
[0009] The feeding utensil component and receptacle component are positioned so that the feeding utensil component is above the receptacle component and the receptacle component is below the feeding utensil component. In this manner most food or liquid that falls off the feeding utensil component lands safely in the receptacle component rather than on an individual. The feeding utensil and receptacle components are positioned so using the positioning component. The positioning component may comprise one or more rods or flat straps. The feeding utensil and receptacle components may be detachably positioned in such a way so that the receptacle component collects most of the food that spills from the feeding utensil component. The feeding utensil and receptacle components may be detachably positioned using a positioning component with, for example, snaps or Velcro straps at the ends of the rods or flat straps. Alternatively, the feeding utensil component and receptacle component may be permanently molded to the positioning component.
[0010] The feeding utensil, receptacle and positioning components may be constructed out of plastic or metal. The feeding utensil and receptacle components should be rigid or unbendable. The positioning component may be rigid or unbendable. Alternatively, the positioning component could be bendable under certain conditions, but unbendable at other conditions. For example, the positioning component could be made from a temperature-sensitive plastic. The positioning component could be warmed up by rubbing with hands or in a microwave to make it bendable. Once the positioning component is warmed it can be molded into a desired shape, then cooled down, and connected to the feeding utensil and receptacle components.
[0011] FIG. 1 illustrates a side view of one of many embodiments of this invention. In this embodiment, the feeding utensil component 10 is a spoon 12 containing some peas. The receptacle component 16 has an oval-shaped bottom surface 18 and a sloping side 20 to collect any peas that may spill. The receptacle component 16 is positioned below the feeding utensil component 10 so as to allow the approach of the individual's mouth in order to allow the individual to consume the food or liquid. The receptacle component is positioned below the feeding utensil component by a positioning component 21 using one or more rod supports 22 . In FIG. 1 , the supports are permanently molded to the feeding utensil component and the receptacle component. Most of the peas that fall off the spoon land in the oval-shaped receptacle.
[0012] In another embodiment, the feeding utensil component is a fork containing some peas. The receptacle component has a trapezoidal-shaped bottom surface and four upright to collect any peas that may spill. The receptacle component is positioned below the feeding utensil component so as to allow the approach of the individual's mouth in order to allow the individual to consume the peas. The receptacle component is positioned below the feeding utensil component by a positioning component using one rod support. The support is permanently molded to the feeding utensil component and the receptacle component. Most of the peas that fall off the fork land in the trapezoidal-shaped receptacle.
[0013] While the invention has been described in the foregoing with reference to details of the illustrated embodiment, these details are not intended to limit the scope of the invention as defined in the appended claims. | The present invention relates to a modified feeding utensil comprising a feeding utensil component and a receptacle component. The receptacle component is either permanently or detachably positioned below the feeding utensil to avoid spills. | 0 |
BACKGROUND OF INVENTION
[0001] This invention relates to a rotor for a permanent magnet type rotary electrical machine having permanent magnets adapted to cooperate with the coils formed on armatures of a stator.
[0002] In both motors and generators such as those used in vehicles such as motorcycles, a rotary machine has been known in which permanent magnets fixed to a rotor are rotated around a stator. In such a machine not only does the rotor rotate at high speed, but also the permanent magnets are subjected to repeated attractive and repulsive forces between the magnets and the coils of the stator. This can and does cause generation of vibration and noise. Because the quality and strength of permanent magnets gas improved and permanent magnets with very large magnetic flux density are now used, the attractive and repulsive forces are increased further.
[0003] To prevent or reduce the generation of vibration and noise, a high rigidity of the rotor is desirable. Therefore, rotors of large thickness has been used and the whole rotor has been made of a casting with substantial thickness.
[0004] Thus although the noise and vibration are reduced the rotor has not only a large weight, but also a large moment of inertia. When such a generator is used in a vehicle, it causes not only an increase in vehicle weight, but also a drop in the acceleration and deceleration of the engine. Because electric power consumption has increased especially in the newer model vehicles the load of the generator is increased. The resulting generator tends to be larger in size and to have a larger capacity. This still further amplifies the weight and moment of inertia.
[0005] It is, therefore, a principle object of this invention to provide a rotor for a rotating electrical machine with increased rigidity without increased weight and moment of inertia to prevent generation of vibration and noise.
[0006] The machines of this type can generate substantial heat and this heat must be dissipated. This can be done by using fans or other auxiliary cooling structures. This brings with it further problems of weight and inertia, not to mention added cost.
[0007] Therefore it is a further object of this invention to provide a rotor for a rotating electrical machine that is capable of effecting improved cooling property as well as its size reduction and capacity increase.
SUMMARY OF INVENTION
[0008] A first feature of the invention is adapted to be embodied in a rotor for a rotating electrical machine comprised of a rim portion carrying a plurality of spaced permanent magnets, a hub portion adapted to be affixed to a rotatable shaft, and an interconnecting portion for interconnecting the rim and hub portions. A plurality of openings are defined by the interconnecting portion for reducing the weight and rotational inertia of said rotor without significantly reducing its strength.
[0009] As a further feature of the rotor set forth in the preceding paragraph, the openings may be formed to create a fan effect for cooling the machine.
[0010] A further feature of the invention is embodied in a rotor for a rotating electrical machine comprised of a rim portion carrying a plurality of spaced permanent magnets, a hub portion adapted to be affixed to a rotatable shaft, and an interconnecting portion for interconnecting the rim and hub portions. In connection with this feature, a plurality of reinforcing ribs are formed in the interconnecting portion.
BRIEF DESCRIPTION OF DRAWINGS
[0011] [0011]FIG. 1 is a cross sectional view of a rotating electrical machine constructed in accordance with a first embodiment of the invention.
[0012] [0012]FIG. 2 is a cross sectional view, in part similar to FIG. 1 but showing only the rotor used in the generator.
[0013] [0013]FIG. 3 is an end elevational view of the rotor.
[0014] [0014]FIG. 4 is an end elevational view of the opposite side of the rotor.
[0015] [0015]FIG. 5 is a sectional view taken along line 5 - 5 of FIG. 4.
[0016] [0016]FIG. 6 is a graph of coil temperature in relation to rotational speed comparing this embodiment with the prior art.
[0017] [0017]FIG. 7 is a cross sectional view, in part similar to FIG. 2, but of a rotor of another embodiment.
[0018] [0018]FIG. 8 is a cross sectional view, in part similar to FIG. 2, but of a rotor of still another embodiment.
[0019] [0019]FIG. 9 is a left side view of the embodiment of FIG. 8 FIG. 10 is a right side view of the embodiment of FIG. 8.
[0020] [0020]FIG. 11 is a cross sectional view taken along the line 11 - 11 of FIG. 10.
DETAILED DESCRIPTION
[0021] Referring first to the embodiment of FIGS. 1 - 5 , a rotating electrical machine such as a generator is indicated generally by the reference numeral 21 . Although described as a generator, it will be readily apparent to those skilled in the art, the invention can be used equally with an electric motor.
[0022] The generator 21 is incorporated in an engine, shown only partially, for a motorcycle or the like, and is disposed and driven at one end of the engine crankshaft 22 (FIG. 1). In such an arrangement, the generator 21 is enclosed in a generator housing section 23 formed between a crankcase 24 of the engine and a generator cover 25 mounted to the crankcase 24 .
[0023] One end of the crankshaft 22 protrudes from the crankcase 24 into the generator housing section 23 . A stator 26 is fixedly supported on the crankcase 24 in surrounding relation to the protruding portion of the crankshaft 22 .
[0024] The stator 26 is formed of radial magnetic pole teeth 27 of a stator core, and coils 28 wound thereon. In the case of a three-phase AC generator, the number of magnetic pole teeth 27 is a multiple of three, and for example, 9, 12, 15 and 18 poles are provided. The winding directions of the coils 28 of each phase are arranged to be normal or reverse corresponding to the magnetic poles of permanent magnets 29 of a rotor, indicated generally by the reference numeral 31 and to be described later, to which these coils 28 face so that voltages induced by the coils 28 of the same phase have the same polarity.
[0025] The rotor 31 is comprised of a hub section 32 fitted fixedly on the crankshaft 22 , a cylindrical section 33 facing close to the outside circumference of the magnetic pole teeth of the stator 26 , and a plate-like spoke section 34 for connecting the hub section 32 and the cylindrical section 26 . In this embodiment, the hub section 32 , spoke section 34 and cylindrical section 33 of the rotor 31 are integrally formed from a material like steel by cold forging or hot forging.
[0026] The hub section 32 is nonrotatably key-fitted on a tapered portion formed at one end of the crankshaft 22 , and fixed axially to the crankshaft 22 by a bolt 35 .
[0027] The permanent magnets 29 are bonded on the inside circumferential surface of the cylindrical section 33 and a small clearance is provided between the permanent magnets 29 and the outside circumference of the stator 26 . The permanent magnets 29 are magnetized such that they have polarities changing circumferentially at regular intervals, that is, into twelve or sixteen poles.
[0028] The permanent magnets 29 used here are preferably neodymium-iron-boron magnets with high flux density. The magnets 29 have a very large flux density, so that their thickness can be decreased, which is suited for size reduction and weight saving of the generator 21 . Between the permanent magnets 29 and the spoke section 34 is mounted a spacer 36 made of non-magnetic material.
[0029] For stiffening purposes, a number of radial ribs 37 are formed on the inside surface of the spoke section 34 , that is, on a surface on the stator 26 side. These ribs 37 extend from the hub section 32 to the cylindrical section 33 . The ends 37 a of the ribs 37 near the cylindrical section 33 are each bent in an arc in the rotational direction R (FIGS. 3 and 4) of the rotor 31 . The spoke section 34 is also formed with a number of windows 38 that extend therethrough in the direction of a rotation axis B of the rotor in a position close to but not interfering with the ribs 37 and particularly their curved portions 37 a.
[0030] Groove-like slant faces 39 are formed on the surface of the spoke section 34 opposite to that on which the ribs 37 are provide. These groove-like slant faces 39 are formed at one side of the windows in the circumferential direction, configured such that they begin at the opening edges (leading side) of the windows 38 and their depths are gradually shallower in the rotational direction (R) of the rotor 26 .
[0031] The generator 21 is air-cooled or liquid-cooled. In the case of liquid cooling, the whole generator is immersed in cooling oil. That is, cooling oil, for example engine lubricating oil, is circulated in the generator housing section 23 . The cooling oil is preferably cooled down by an oil cooler or the like (not shown).
[0032] As is clear from FIGS. 3, 4, this embodiment has twelve ribs 37 and twelve windows 38 , so that the number of magnetic poles of the magnets 29 fixed to the cylindrical section 33 is preferably twelve. However, it should be understood that the numbers of ribs 37 and windows 38 are not limited to that, but they may be changed depending on the number of magnetic poles of the permanent magnets or the like.
[0033] In this generator 21 , rotation of the crankshaft 22 causes the rotor 31 to rotate in the direction (R). As a result of the rotation of the rotor 31 , magnetic field produced by the permanent magnets 29 fixed to the cylindrical section 33 is rotated, which changes the number of magnetic fluxes passing through coils of the stator 26 , resulting in induction of voltages in the coils. The permanent magnets 29 are subjected alternately to attractive and repulsive forces every time they move past different magnetic pole teeth while facing thereto. These forces form a vibration source to the cylindrical section 33 , which could cause vibration of the entire rotor 31 .
[0034] However since the cylindrical section 33 and the spoke section 34 of the rotor 31 are united in one body and the spoke section 34 is formed with the ribs 37 the rotor is stiffened. Thus, sufficiently large rigidity is effected for the united body of the cylindrical section 33 and the spoke section 34 , so that vibration of the united body of the cylindrical section 33 and the spoke section 34 is restricted, decreasing noise associated with the vibration. This is also accomplished without unnecessarily increasing the total weight.
[0035] In addition, the formation and shape of the windows 38 causes cooling air or cooling oil in the generator housing 23 to be circulated inside the rotor 31 , accelerating the cooling of the stator 26 . Therefore, size reduction and capacity increase of the generator 21 is effected. In this case, the cooling air or the cooling oil which has entered the rotor 31 , strikes against the ribs 37 is dispersed into surrounding areas. Thus, the ribs 37 have the function of enhancing cooling effects.
[0036] Because the opening edges of the windows on the opposite side from the ribs are formed slant faces 39 in the rotational direction (A) of the rotor, cooling air (oil) flows efficiently into the rotor 31 along the slant faces 39 as guides. Thus, improvement of cooling performance is further effected. Further, the ribs 37 are bent in the rotational direction (R) of the rotor at the ends on the cylindrical side, so that cooling air (oil) which has entered at the windows 38 is introduced radially inwardly of the rotor along the bent sections 37 A as guides. Therefore, cooling air (oil) is possibly introduced successfully also to the rotor 31 near the hub section 32 , enabling improvement of the cooling property as well.
[0037] [0037]FIG. 6 illustrates the stator coil temperature, in comparison, of the case where ribs ( 37 ), windows ( 38 ) and slant faces ( 39 ) are provided according to this embodiment (cooling type, dash lines) and the case where no ribs, windows nor slant faces are provided (standard type, dash lines). In this case, measurement of the stator coil temperature is made on the generator 21 under the same load.
[0038] According to the result of the measurements, it can be seen that maximum temperature of the coil and ΔT max (rise of the coil temperature relative to the temperature of the mounting seat surface of the coil) are both considerably lower in the cooling type according to this invention than in the standard type.
[0039] [0039]FIG. 7 illustrates a rotor of another embodiment. A rotor indicated generally at 31 a is arranged such that a hub section 32 a is separated from the united body of a cylindrical section 33 a and a spoke section 34 a , and both members are coupled with rivets 51 . In this embodiment, the rotor 31 a is divided into two members ( 32 a and the united body of 33 a and 34 a ) without decreasing the effect of this invention, thereby facilitating forming of each member. In FIG. 7, like parts as shown in FIG. 2 are designated by like reference numerals and further description is believed to be unnecessary to permit those skilled in the art to utilize this embodiment.
[0040] Referring now to FIGS. 8 - 11 , a rotor constructed in accordance with another embodiment is indicated generally at 31 b . The rotor 31 b is similar to that of FIGS. 1 - 5 in that a hub section 32 b , a cylindrical section 33 b and a spoke section 34 b are molded integrally. The spoke section 34 b is formed with approximately fan-shaped twelve windows 38 b at regular intervals in the circumferential direction.
[0041] As a result, between adjacent windows 38 b are formed straight sections 61 extending approximately in the radial direction. These straight sections 61 act as stiffening ribs. On one edges of the straight sections 61 on the side in the leading side of the rotational direction of the rotor are formed, by chamfering, slant faces 62 in the longitudinal direction of the straight sections 61 . That is, the slant faces 62 face to the outside of the rotor 31 b.
[0042] In this embodiment, with the rotor 31 b rotating in the direction of R, cooling air or cooling oil flows smoothly and efficiently into the rotor 31 b along the slant faces 62 as guides. In FIG. 11, dash lines show the flow of the cooling air (oil). Therefore, cooling properties of the rotor 31 b and the stator (not shown) enclosed in the rotor 31 b is improved.
[0043] Thus it can be seen that in the disclosed embodiments ribs of the rotor extend approximately radially. Therefore, rigidity can be increased without need of increasing the weight and moment of inertia of the rotor, so that vibration of the stator is restricted as well as generation of noise. Also openings formed between the ribs permit coolant to flow from one side of the rotor to the other for cooling. Of course, the embodiments described are only preferred embodiments of the invention and various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims. | Several embodiments of rotors for rotating electrical machines configured to increase the stiffness without increasing the weight and to promote the flow of coolant across the rotor. This is achieved by utilizing stiffening ribs and flow openings in an intermediate portion of the rotor that interconnects the cylindrical portion that carries the permanent magnets and the hub section. | 7 |
[0001] This is a continuation-in-part of U.S. patent application Ser. No. 11/675,637, filed Feb. 16, 2007, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a biochip, and particularly relates to a biochip for nucleic acid hybridization and a method for accelerating the rate of hybridization between a target nucleic acid and a nucleic acid probe.
[0004] 2. The Prior Arts
[0005] The hybridization method in which the nucleic acid probe is hybridized to the target nucleic acid is one of the most common analytical techniques to confirm whether the target DNA has the desired gene or nucleic acid sequence or not, wherein the nucleic acid probe is a nucleic-acid fragment that is complementary to another nucleic-acid sequence and thus, when labeled in some manner, as with a radioisotope, can be used to identify complementary segments present in the nucleic-acid sequences of various nucleic acids. Conventionally, the blotting process used in hybridization analysis is to transfer the target nucleic acid to a substrate such as membrane, and then the nucleic acid probe with specificity is applied for hybridization, and then the color, chemiluminescence, or radioactivity exhibited by the labeled molecules in the nucleic acid probe is detected whereby it is possible to judge whether a target base sequence is present in the target nucleic acid or not.
[0006] One of the hybridization techniques used today is the “Southern blotting”, in which the target DNA is transferred from an electrophoresis gel to a membrane, and then hybridized with a probe. When used with RNA target the method is called “Northern blotting”. In the other methods, in accordance with the dropping area the target nucleic acid is directly dropped onto the membrane by dot blotting, slot blotting, or spot blotting. In the dot blotting, slot blotting, and spot blotting method, the nucleic acid can be directly blotted onto a substrate without the transfer process of electrophoresis. Therefore, the analysis time for target nucleic acid is reduced. The Blotting method can be used in the qualitative analysis by batch.
[0007] In the conventional blotting assay, after the target nucleic acid is dropped onto the surface of the membrane, the nucleic acid is permanently attached to the membrane by cross-linking using heating or UV radiation so that the target nucleic acid will remain on the film when being washed after the step of hybridization with a probe. Because the target nucleic acid is dropped onto a wet surface of a membrane, and then diffuses and adsorbs on the wet surface under the known working conditions. Most of the target nucleic acid is only firmly absorbed on the membrane surface and the nearby pores thereof, and thereby the numbers of nucleic acid molecules firmly absorbed are limited, and thus the produced hybridization signal is relatively weak. As a result, if the amount of the nucleic acid sample is not enough or the nucleic acid sample has a long molecular chain, the reaction sensitivity will be greatly reduced. When the probe hybridization solution containing the blocking reagent is added to the membrane, the nucleic acid probe can only diffuse on the surface of the membrane as the target nucleic acid does, and find out the target nucleic acid for hybridization in Brownian movement. Therefore, the nucleic acid hybridization reaction takes more processes to be accomplished, and the reaction time is more than 10 hours. Therefore, the hybridization results cannot be obtained in a short time. In addition, it is not economical for the qualitative analysis of the nucleic acids if the hybridization assay takes long time and needs lots of reagents. Therefore, there is a need for the development of a simple blotting device and a blotting method to reduce the process steps and time for hybridization assay and to reduce the background noise, and thus such a blotting device and such a blotting method can be applied to the detection for simple or batch process.
SUMMARY OF THE INVENTION
[0008] In order to solve the time-consuming problem in hybridization assay when the nucleic acid probe is base-paired with the target nucleic acid by Brownian motion, and in order to increase the amount of target nucleic acid firmly absorbed on the surface and the inside of the pores of the membrane for increasing base pairing probabilities and reaction sensitivity, the present invention provides a biochip for nucleic acid hybridization assays. In the present invention, the inside space of the biochip is limited so that the target nucleic acid and the nucleic acid probe can rapidly diffuse into the micropores of the substrate in a very short time and are base paired with each other when the hybridization solution enters the inside of the substrate. Furthermore, under the condition of pressurizing the fluid, the target nucleic acid and the nucleic acid probe can move rapidly, and because the adsorption and reaction area of the target nucleic acid and the nucleic acid probe are enlarged when they flow into the inside of the membrane, the number of base pairing is increased, which can enhance the detection sensitivity. Meanwhile, the base pairing between the target nucleic acid and the nucleic acid probe is speeded up due to the flowing movement of the nucleic acid molecules. Moreover, because the washing solution can be deeply flushed into the inside of the membrane and washes away the probe molecules unspecifically bound to the membrane, and thereby the cleanness is improved and the reaction background level is reduced.
[0009] In order to achieve the above objectives, the present invention provides a biochip, comprising: a hybridization chamber which is in the form of a cavity, a porous membrane pressed in the hybridization chamber; and at least one first circulation hole and at least one second circulation hole which are communicated with the hybridization chamber so that the reaction solution flows in the at least one first circulation hole and flows out the at least one second circulation hole through the pores of the porous membrane. The biochip includes an upper substrate and a lower substrate, wherein the upper substrate and the lower substrate are stacked together one on top of the other to form the hybridization chamber therein, and the porous membrane is provided in the hybridization chamber, and at least one first circulation hole located at the upper substrate and at least one second circulation hole, which are communicated with the hybridization chamber, are provided on the top and the side of the hybridization chamber, respectively.
[0010] There is no specific limitation on the shape and the thickness of the hybridization chamber, and its shape and thickness can be changed with the porous membrane structure. An interstice with predetermined width is left between the porous membrane and the sidewall of the hybridization chamber so that the reaction solution can enter the porous membrane from the side thereof. In addition, the central top of the hybridization chamber is provided with a first circulation hole. There is no specific limitation on the position and the number of the first circulation hole. The first circulation hole, the second circulation hole, and the hybridization chamber can be further communicated with a microchannel, and the reaction solution can rapidly pass through the porous membrane by pressurizing the reaction solution via the microchannel, and thereby the reaction rate is increased. If the porous membrane is in a dry state before the reaction, the reaction solution can rapidly enter the inside of the porous membrane due to the capillary attraction of the pores of the membrane. The porous membrane has a pore diameter of 0.1 μm to 50 μm. The porous membrane can be a nylon membrane, a nitrocellulose membrane, or any other suitable membrane.
[0011] In the biochip of the present invention, the target nucleic acid can enter the hybridization chamber via one or more circulation holes and can be absorbed by the membrane therein. Because the target nucleic acid can enter the inside of the membrane, the number of the target nucleic acid molecules firmly adsorbed by the membrane is increased, which can enhance the detection sensitivity. After the target nucleic acid molecules are firmly adsorbed by the membrane, the nucleic acid probe solution enters the membrane pressed in the hybridization chamber via one or more circulation holes and anneals with the target nucleic acid. Because the nucleic acid probe can easily move in the pores of the membrane, it can anneal with the target nucleic acid in a very short time. Furthermore, the washing solution is flushed into the membrane via one or more circulation holes for washing. Because the nucleic acid probe can easily move in the pores of the membrane, the nucleic acid probe molecules unspecifically bound to the membrane can be easily and rapidly flushed out of the membrane. Therefore, the washing process is rapid and complete, the reaction time is shortened, and the background noise level is reduced.
[0012] The present invention provides a biochip, comprising an upper substrate and a lower substrate, which are stacked together one on top of the other. A hybridization chamber is provided between the upper substrate and the lower substrate, and a porous membrane is provided in the hybridization chamber. A plurality of little pillars protrude from an interface between a bottom of the upper substrate and the hybridization chamber wherein the ends of the little pillars are in contact with the surface of the porous membrane pressed in the hybridization chamber. In addition, at least one first circulation hole located at the upper substrate and at least one second circulation hole are provided on a top and a side of the hybridization chamber, respectively, wherein the second circulation hole is communicated with the interspace among the little pillars, so that the reaction solution is able to fill up the interspace among the little pillars via the second circulation hole and then enters the membrane. By using such little pillars, the area occupied by the reaction solution in the membrane is enlarged, and thereby the rate of the reaction solution that enters the membrane and its efficiency are increased. As a result, the reaction is rapid and complete.
[0013] The present invention provides a biochip comprising an upper substrate and a lower substrate, and the lower substrate can be a single-layer lower substrate or can be composed of a top substrate and a bottom substrate. The third circulation hole which is communicated with hybridization chamber can be provided in a single-layer lower substrate or in a lower substrate composed of a top substrate and a bottom substrate. The third circulation hole is further communicated with the second microchannel, and the second microchannel is further communicated with the fourth circulation hole so that the reaction solution can enter the membrane from the bottom of the lower substrate. Therefore, the reaction solution can enter the membrane from different flow paths.
[0014] Moreover, in order to solve the time-consuming problem in hybridization assay when the nucleic acid probe is base-paired with the target nucleic acid by Brownian motion, and in order to increase the amount of target nucleic acid firmly absorbed on the surface and the inside of the pores of the fiber substrate for increasing base pairing probabilities and reaction sensitivity, the present invention also provides a method for hybridizing a nucleic acid probe to a target nucleic acid, comprising the following steps: providing a fiber substrate having a plurality of pores; transferring the target nucleic acid to the fiber substrate by means of a first liquid flow, the first liquid flow being accelerated from an inlet side to an exit side of the fiber substrate, wherein the target nucleic acid is captured by the fiber substrate, and stretched and wound around fibers of the fiber substrate; fixing the target nucleic acid on the fiber substrate; transferring the nucleic acid probe to the fiber substrate by means of a second liquid flow, the second liquid flow being accelerated from the inlet side to the exit side of the fiber substrate, wherein the nucleic acid probe is captured by the fiber substrate, and is stretched and wound around fibers of the fiber substrate; and hybridizing the target nucleic acid with the nucleic acid probe on the fiber substrate for a time period sufficient for base-pairing the nucleic acid probe with the target nucleic acid and forming a hybridization product.
[0015] Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1A is an exploded view of the biochip according to the first embodiment of the present invention;
[0017] FIG. 1B is a cross-section view after the biochip is assembled according to the first embodiment of the present invention;
[0018] FIG. 1C is a top view after the biochip is assembled according to the first embodiment of the present invention;
[0019] FIG. 1D is a schematic view of the solution flowing direction during the hybridization reaction according to one preferred embodiment of the present invention;
[0020] FIG. 1E is a schematic view of the solution flowing direction during the hybridization reaction according to another embodiment of the present invention;
[0021] FIG. 1F is a top view of another biochip in square shape derived from the embodiment of the present invention;
[0022] FIG. 2A is an exploded view of the biochip according to an embodiment of the present invention;
[0023] FIG. 2B is a cross-section view after the biochip is assembled according to the embodiment of the present invention;
[0024] FIG. 2C is a top view after the biochip is assembled according to the embodiment of the present invention;
[0025] FIG. 2D is a schematic view of the solution flowing direction during the hybridization reaction according to the embodiment of the present invention;
[0026] FIG. 3A is an exploded view of the biochip according to an embodiment of the present invention;
[0027] FIG. 3B is a cross-section view after the biochip is assembled according to the embodiment of the present invention;
[0028] FIG. 3C is a top view after the biochip is assembled according to the embodiment of the present invention;
[0029] FIG. 3D is a schematic view of the solution flowing direction during the hybridization reaction according to the embodiment of the present invention;
[0030] FIG. 4A is an exploded view of the biochip according to an embodiment of the present invention;
[0031] FIG. 4B is a cross-section view after the biochip is assembled according to the embodiment of the present invention;
[0032] FIG. 4C is a top view after the biochip is assembled according to the embodiment of the present invention; and
[0033] FIG. 4D is a schematic view of the solution flowing direction during the hybridization reaction according to the embodiment of the present invention.
[0034] FIG. 5 is the fluorescent microscope image of the fluorescent nucleic acid probes present in the porous membrane according to one embodiment of the present invention.
[0035] FIG. 6 is the fluorescent microscope image of the fluorescent nucleic acid probes present in the porous membrane according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0036] FIG. 1A is an exploded view of the biochip of the first embodiment of the present invention. With reference to FIG. 1A , the biochip of this embodiment comprises an upper substrate 10 , a lower substrate 20 , and a porous membrane 30 , wherein the upper substrate 10 and the lower substrate 20 are stacked together, and the porous membrane 30 is provided in the hybridization chamber 11 . The porous membrane 30 having an upper surface which is tightly contacted with a lower surface of the upper substrate 10 , and having a lower surface which is tightly contacted with an upper surface of the lower substrate 20 , an interstice 15 is defined between the porous membrane 30 and a sidewall of the hybridization chamber 11 .
[0037] With reference to FIG. 1A , FIG. 1C , and FIG. 1E , the upper substrate 10 has a hybridization chamber 11 , which is in the form of a disk-shaped cavity. However, the shape, the size and the thickness of the hybridization chamber 11 have no restriction, and the hybridization chamber 11 can be a tetrahedral cavity (as shown in FIG. 1E ). The center of hybridization chamber 11 is provided with a first circulation hole 12 . There is no specific limitation on the position of the first circulation hole 12 , and the position of the first circulation hole 12 can be changed with the position of another circulation hole so that the reaction solution can flow over the whole inside of the porous membrane 30 . As FIG. 1A shows, the first circulation hole 12 is located at the upper substrate and on the top of the hybridization chamber 11 , whereas in FIG. 1E the first circulation hole 12 ′ may either be located on the side of the hybridization chamber 11 . Besides, there is also no specific limitation on the number of the first circulation holes 12 . The first circulation hole 12 can be further communicated with a microchannel (such as the microchannel 17 communicated with one side of the hybridization chamber 11 shown in FIG. 1E ) or another circulation hole (not shown in the drawings) for facilitating solution injection.
[0038] The first microchannel 14 is communicated with one side of the hybridization chamber 11 , and the first microchannel 14 is further communicated with the second circulation holes 13 . There is no specific limitation on the number and the positions of the first microchannels 14 , and the number and the positions thereof can be changed with the flow path of the reaction solution. In addition, an interstice 15 with predetermined width is left between the porous membrane 30 and the sidewall of the hybridization chamber 11 . The interstice 15 has a width of 0.05 to 0.2 mm, and preferably 0.1 mm. In another example, two interstices 15 ′ with predetermined width, as shown in FIG. 1E , are respectively left between the porous membrane 30 ′ and the sidewall of the hybridization chamber 11 , and not communicated.
[0039] With reference to FIG. 1A and FIG. 1B , the hybridization chamber 11 , the first microchannel 14 , and the second circulation hole 13 are formed between the upper substrate 10 and the lower substrate 20 . The hybridization chamber 11 , the first microchannel 14 , and the second circulation holes 13 are not limited to be located on the upper substrate 10 , but they may be located on the lower substrate 20 , or on both the upper substrate 10 and the lower substrate 20 (divided into male and female halves). The upper substrate 10 and the lower substrate 20 may be separately manufactured, or integrally manufactured, and the hybridization chamber 11 , the first microchannel 14 , and the second circulation hole 13 will be formed inside the substrates while manufactured.
[0040] The biochip of this embodiment includes, but not limited to, a microfluidic chip, a nanofluidic chip, or any other structure which is suitable to the present invention. The quartz, glass, or the like can be used as the substrate of the microfluidic chip, and the capillary microchannels are formed by wet etching, and a layer of quartz, or glass covers the tops of the capillary microchannels, and then the chip with the closed microchannels or cavities is produced. Alternatively, the substrate of the biochip is made of the hard polymer, for example, polymethyl methacrylate (PMMA), polycarbonate (PC). First, the mother mold is made by wet-etching the quartz, and then the microchannels are formed on the PMMA or PC material by the embossing method, and then the tops of the microchannels is covered with the same material as the substrate. The substrate of the biochip of the present invention can also be made of soft polymer, for example, polydimethyl siloxane (PDMS). Because of good flowing ability, the thermal compression is not needed so that the mother mold will not be easily damaged, and the biochips can be manufactured in large scale. This makes PDMS a preferable material to be used.
[0041] The porous membrane 30 can be a fiber membrane, such as a nylon membrane, a nitrocellulose membrane, or any other suitable membrane fitted in shape for the hybridization chamber 11 . The nylon membrane is positive charged or neutral. The nylon membrane and nitrocellulose membrane have a pore diameter of 0.1 μm to 0.5 μm. The proper porous diameter is selected based on the molecular weight of the target nucleic acid, and the larger the nucleic acid, the larger the porous diameter is used. The pore diameter is preferably 0.2 μm to 0.45 μm. Moreover, the porous membrane can be in a dry state so that the injected target nucleic acid can be adsorbed on the porous membrane rapidly. Furthermore, the target nucleic acid can be DNA or RNA.
[0042] FIG. 1D is the schematic view showing the flow direction of the hybridization solution according to one preferred embodiment of the present invention. With reference to FIG. 1D , the target nucleic acid solution T is injected into the second circulation hole 13 , and then flows through the first microchannel 14 and enters the interstice 15 surrounding the periphery of the porous membrane 30 . After entering the interstice 15 , the interstice 15 is firstly filled with the target nucleic acid solution T, and then the target nucleic acid solution T diffuses toward the center of the porous membrane 30 from the periphery of the porous membrane 30 , and finally is discharged to the outside via the first circulation hole 12 . Furthermore, if the porous membrane 30 is in a dry state, the target nucleic acid solution T can rapidly enter the inside of the porous membrane 30 due to the capillary attraction of the micropores of the porous membrane 30 . Moreover, the target nucleic acid solution T which enters the porous membrane 30 can be permanently attached to the surface and the inside of the porous membrane 30 by heating or UV irradiation.
[0043] Afterwards, the nucleic acid probe solution P is also injected via the second circulation hole 13 for hybridization reaction. The added nucleic acid probe solution P will take the same flow path as the target nucleic acid solution T, and distribute over the whole porous membrane 30 . The nucleic acid probe is labeled with chromogenic molecules in order to detect the results of hybridization reaction. The nucleic acid probes can be detectably labeled, for example, with a radioisotope, a fluorescent compound, or an enzyme. If the porous membrane 30 is in a dry state before the nucleic acid probe solution P is added, the nucleic acid probe solution P can also rapidly enter the inside of the porous membrane 30 . After the nucleic acid probe solution P is added, the biochip is placed at a proper temperature (such as 40 to 48° C.) for 2 to 5 minutes to allow the nucleic acid probe to base-pair with the target nucleic acid, and thus the process of hybridization is completed.
[0044] After the process of hybridization, the unhybridized nucleic acid probes are washed away. During the washing process, the washing solution W is flushed into the hybridization chamber 11 via the first circulation hole 12 , and enters the inside of the porous membrane 30 from the center thereof. After entering the inside of the porous membrane 30 , the washing solution W diffuses across the porous membrane 30 to the interstice 15 which surrounds the periphery of the porous membrane 30 . Then, the washing solution W flows through the first microchannel 14 , and is discharged to the outside via the second circulation hole 13 . Because the washing solution W is flushed from the outside of the porous membrane 30 to the inside of the porous membrane 30 , the nucleic acid probe, which is a relatively small molecule, can be easily and rapidly flushed out of the pores of the porous membrane 30 . Therefore, the background noise level is reduced, and the time for flushing is shortened. Then, the nucleic acid probes labeled with chromogenic molecules are detected, and the results of hybridization reaction are obtained and thereby the complementary sequence of the nucleic acid sequence of the nucleic acid probe present in the sequence of the target nucleic acid is determined.
[0045] FIG. 1E is the schematic view showing the flow direction of the hybridization solution. With reference to FIG. 1E , the target nucleic acid solution T is injected into the hybridization chamber 11 via the first circulation hole 12 , and enters the inside of the porous membrane 30 from the center thereof. After entering the inside of the porous membrane 30 , the target nucleic acid solution T diffuses across the porous membrane 30 to the interstice 15 which surrounds the periphery of the porous membrane 30 . Then, the target nucleic acid solution T flows through the first microchannel 14 , and is discharged to the outside via the second circulation hole 13 . If the porous membrane 30 is in a dry state, the target nucleic acid solution T can rapidly enter the inside of the porous membrane 30 due to the capillary attraction of the micropores of the porous membrane 30 . Moreover, the target nucleic acid solution T which enters the porous membrane 30 can be permanently attached to the surface and the inside of the porous membrane 30 by heating or UV irradiation.
[0046] Afterwards, the nucleic acid probe solution P is injected into the hybridization chamber 11 via the first circulation hole 12 for hybridization reaction. The nucleic acid probe is labeled with chromogenic molecules in order to detect the results of hybridization reaction. The nucleic acid probes can be detectably labeled, for example, with a radioisotope, a fluorescent compound, or an enzyme. The added nucleic acid probe solution P will take the same flow path as the target nucleic acid solution T, and distribute over the whole membrane 30 . If the porous membrane 30 is in a dry state before the nucleic acid probe solution P is added, the nucleic acid probe solution P can also rapidly enter the inside of the porous membrane 30 . After the nucleic acid probe solution P is added, the biochip is placed at a proper temperature (such as 40 to 48° C.) for several minutes to allow the nucleic acid probe to anneal with the target nucleic acid, and thus the process of base pairing is completed.
[0047] After the process of base pairing, the unhybridized nucleic acid probes are washed away. The washing solution W is injected via the second circulation hole 13 during the washing process. The washing solution W is flushed into the hybridization chamber 11 through the first microchannel 14 . When the washing solution W is flushed into the hybridization chamber 11 , the interstice 15 is firstly filled with the washing solution, and then the washing solution W diffuses toward the center of the porous membrane 30 from the edge of the porous membrane 30 , and finally is discharged to the outside via the first circulation hole 12 . Because the washing solution W is flushed from the outside of the porous membrane 30 to the inside of the porous membrane 30 , the nucleic acid probe, which is a relatively small molecule, can be easily and rapidly flushed out of the pores of the porous membrane 30 . Therefore, the background noise level is reduced, and the time for flushing is shortened. Then, the nucleic acid probes labeled with chromogenic molecules are detected, and the results of hybridization reaction are obtained.
[0048] A test for the flow directions of the nucleic acid probe solution is done. In one case, the fluorescent nucleic acid probe (such as 20-mer DNA oligomers) solution P is injected into the second circulation hole 13 , and then flows through the first microchannel 14 , enters the interstice 15 , and diffuses toward the center of the porous membrane 30 from the periphery of the porous membrane 30 , and finally is discharged to the outside via the first circulation hole 12 , wherein the fluorescent nucleic acid probe solution P is accelerated from the second circulation hole 13 to the first circulation hole 12 due to a reduction in the flow area (by considering mass conservation). Then, the porous membrane 30 with the fluorescent nucleic acid probes is dried. The dried porous membrane 30 with the fluorescent nucleic acid probes is observed using a fluorescent microscope, and the fluorescent microscope image obtained is shown in FIG. 5 . In another case, the fluorescent nucleic acid probe solution P is injected into the hybridization chamber 11 via the first circulation hole 12 , and enters the inside of the porous membrane 30 from the center thereof. After entering the inside of the porous membrane 30 , the target nucleic acid solution T diffuses across the porous membrane 30 to the interstice 15 , and then flows through the first microchannel 14 , and is discharged to the outside via the second circulation hole 13 . Then, the porous membrane 30 with the fluorescent nucleic acid probes is dried. The dried porous membrane 30 with the fluorescent nucleic acid probes is observed using a fluorescent microscope, and the fluorescent microscope image obtained is shown in FIG. 6 .
[0049] From the above flow direction test, it surprisingly found that when the nucleic acid probe solution P diffuses toward the center of the porous membrane 30 from the periphery of the porous membrane 30 , the nucleic acid probe can be captured by the porous membrane 30 , and stretched and wound around the fibers of the porous membrane 30 due to the change in strain. In this case, it is noted that the nucleic acid probe solution P is accelerated from the periphery (the inlet side) to the center (the exit side) of the porous membrane 30 due to the mass conservation law so that the length of the nucleic acid probe becomes more stretched towards the center than in the periphery of the porous membrane 30 . As a result, a lot of the nucleic acid probe molecules are present in the porous membrane 30 (see FIG. 5 ). By contrast, when the nucleic acid probe solution P diffuses toward the periphery of the porous membrane 30 from the center of the porous membrane 30 , the nucleic acid probe cannot be captured by the porous membrane 30 . This is because the nucleic acid probe solution P is decelerated from the center (the inlet side) to the periphery (the exit side) of the porous membrane 30 that the length of the nucleic acid probe cannot be stretched. As a result, much less of the nucleic acid probe molecules are present in the porous membrane 30 (see FIG. 6 ). By considering mass conservation, the same results for the nucleic acid probe solution P should be also applied to the target nucleic acid (such as large molecules of DNA) solution T.
[0050] FIG. 2A is an exploded view of the biochip of the second embodiment of the present invention. With reference to FIG. 2A , the biochip of this embodiment comprises an upper substrate 40 , a lower substrate 20 , and a membrane 30 , wherein the upper substrate 40 and the lower substrate 20 are stacked together one on top of the other, and the porous membrane 30 is provided in the hybridization chamber 41 located on the upper substrate 40 .
[0051] With reference to FIG. 2A to FIG. 2C , the upper substrate 40 has a hybridization chamber 11 , which is in the form of a disk-shaped cavity. However, the shape, the size and the thickness of the hybridization chamber 41 have no restriction, and the hybridization chamber 41 can be a tetrahedral cavity. The center of hybridization chamber 41 is provided with a first circulation hole 42 . There is no specific limitation on the numbers and the positions of the first circulation hole 42 , and the positions of the first circulation hole 42 can be changed with the position of another circulation hole so that the reaction solution can flow over the whole inside of the porous membrane 30 . In addition, the first circulation hole 42 can be further communicated with a microchannel or another circulation hole (not shown in the drawing) for facilitating the solution injection.
[0052] A plurality of little pillars 411 protrude from the interface between the bottom of the upper substrate 40 and the hybridization chamber 41 . The ends of these little pillars 411 are in contact with the surface of the porous membrane 30 located in the hybridization chamber after the biochip is assembled.
[0053] A pair of the first microchannel 44 are respectively communicated with the hybridization chamber 41 , and the pair of the first microchannel 44 are further respectively communicated with a pair of the second circulation holes 43 . There is no specific limitation on the number and the positions of the first microchannel 44 , and the number and the positions thereof can be changed with the flow path of the reaction solution. The second circulation holes 43 and the first microchannels 44 are communicated with the interspace among the little pillars 411 . In addition, an interstice 45 with predetermined width is left between the porous membrane 30 and the sidewall of the hybridization chamber 41 . The interstice 45 has a width of 0.05 to 0.2 mm, and preferably 0.1 mm.
[0054] With reference to FIG. 2A and FIG. 2B , the hybridization chamber 41 , the first microchannels 44 , and the second circulation hole 43 are formed between the upper substrate 40 and the lower substrate 20 . The hybridization chamber 41 , the first microchannels 44 , and the second circulation holes 43 are not limited to be located on the upper substrate 40 , but they may be located on the lower substrate 20 , or on the upper substrate 40 and the lower substrate 20 (divided into male and female halves). Once the upper substrate 40 and the lower substrate 20 are stacked together one on top of the other, the desired structures of the hybridization chamber, the microchannels, and the circulation holes will be formed.
[0055] The biochips can be fabricated by the conventional method. There is no specific limitation on the material, the shape, and the pore size of the porous membrane 30 .
[0056] FIG. 2D is the schematic view showing the flow direction of the hybridization solution according to the second embodiment. With reference to FIG. 2D , before the hybridization reaction, the target nucleic acid solution T is injected into the hybridization chamber 41 from the second circulation hole 43 on the left side of the hybridization chamber through the first microchannels 44 . The target nucleic acid solution T firstly fills up the interstice 45 , and then enters the inside of the porous membrane 30 from the lateral side of the porous membrane 30 . While entering the porous membrane 30 from the lateral side thereof, the target nucleic acid solution T fills up the interspace among the little pillars 411 and then diffuses from the top side the porous membrane 30 to the bottom side thereof. Finally, the target nucleic acid solution T flows through first microchannels 44 on the right side of the hybridization chamber, and is discharged to the outside via the second circulation hole 43 . and the first circulation hole 42 . If the porous membrane 30 is in a dry state, the target nucleic acid solution T can rapidly enter the inside of the porous membrane 30 due to the capillary attraction of the fine pores of the porous membrane 30 . Moreover, the target nucleic acid solution T which enters the porous membrane 30 can be permanently attached to the surface and the inside of the porous membrane 30 by heating or UV irradiation.
[0057] Afterwards, the nucleic acid probe P is injected into the hybridization chamber 41 via the first circulation hole 42 for hybridization reaction. After the nucleic acid probe solution P is added, the added nucleic acid probe solution P will take the same flow path as the target nucleic acid solution T as exemplified in the first embodiment, and distribute over the whole membrane 30 . If the porous membrane 30 is in a dry state before the nucleic acid probe solution P is added, the nucleic acid probe solution P will rapidly enter the inside of the porous membrane 30 . After the nucleic acid probe solution P is added, the biochip is placed at a proper temperature (such as 40 to 48° C.) for several minutes to allow the nucleic acid probe to anneal with the target nucleic acid, and thus the process of base pairing is completed.
[0058] After the process of base pairing, the unhybridized nucleic acid probes are washed away. The washing solution W is flushed into the hybridization chamber 41 from the second circulation hole 43 on the left side through the first microchannel 44 . When the washing solution W is flushed into the hybridization chamber 41 , the washing solution W diffuses toward the center and the bottom of the porous membrane 30 from the lateral side and the top side of the porous membrane 30 , respectively, and finally is discharged to the outside through the first circulation hole 42 and the second circulation hole 43 on the right side. Because the washing solution W is flushed from the lateral side and the top side of the porous membrane 30 to the inside of the porous membrane 30 , the nucleic acid probe, which is a relatively small molecule, can be easily and rapidly flushed out of the pores of the porous membrane 30 . Therefore, the background noise level is reduced, and the time for flushing is shortened.
[0059] FIG. 3A is an exploded view of the biochip of the third embodiment of the present invention. With reference to FIG. 3A , the biochip of this embodiment comprises an upper substrate 50 , a lower substrate 20 composed of a top substrate 201 and a bottom substrate 202 , and a membrane 30 , wherein the upper substrate 50 , the top substrate 201 , and the bottom substrate 202 are stacked together one on top of the other, and the porous membrane 30 is provided in the hybridization chamber 41 located on the upper substrate 50 .
[0060] With reference to FIG. 3A to FIG. 3C , the upper substrate 40 has a hybridization chamber 51 , which is in the form of a disk-shaped cavity. However, the shape, the size and the thickness of the hybridization chamber 41 have no restriction, and the hybridization chamber 41 can be a tetrahedral cavity. The hybridization chamber 41 is provided with a first circulation hole 52 . There is no specific limitation on the numbers and the positions of the first circulation hole 52 , and the positions of the first circulation hole 52 can be changed with the position of another circulation hole so that the reaction solution can flow over the whole inside of the porous membrane 30 . In addition, the first circulation hole 52 can be further communicated with a microchannel or another circulation hole (not shown in the drawing) for facilitating solution injection.
[0061] A plurality of little pillars 511 protrude from the interface between the bottom of the upper substrate 50 and the hybridization chamber 51 . The ends of these little pillars 511 are in contact with the surface of the porous membrane 30 located in the hybridization chamber after the biochip is assembled.
[0062] A pair of the first microchannel 54 are respectively communicated with the hybridization chamber 51 , and the pair of first microchannels 54 are further respectively communicated with a pair of the second circulation holes 53 . There is no specific limitation on the number and the positions of the first microchannels 54 , and the number and the positions thereof can be changed with the flow path of the reaction solution. The second circulation holes 53 and the first microchannels 54 are communicated with the interspace among the little pillars 411 . In addition, an interstice 55 with predetermined width is left between the porous membrane 30 and the sidewall of the hybridization chamber 51 . The interstice 55 has a width of 0.05 to 0.2 mm, and preferably 0.1 mm.
[0063] The lower substrate 20 is composed of a top substrate 201 and a bottom substrate 202 , which are stacked together one on top of the other. The top substrate 201 has the third circulation hole 2011 , and the bottom substrate 202 has the third circulation hole 2021 corresponding to the third circulation hole 2011 . The third circulation hole 2011 or 2021 can be provided in a single-layer lower substrate 20 or in a lower substrate 20 composed of a top substrate 201 and a bottom substrate 202 as this embodiment. The third circulation hole 2021 is further communicated with the second microchannel 2022 , and the second microchannel 2022 is further communicated with the fourth circulation hole 2023 .
[0064] With reference to FIG. 3A and FIG. 3B , the hybridization chamber 51 , the first microchannels 54 , and the second circulation hole 53 are formed between the upper substrate 50 and the lower substrate 20 . The hybridization chamber 51 , the first microchannels 54 , and the second circulation holes 53 are not limited to be located on the upper substrate 50 , but they may be located on the lower substrate 20 , or on both the upper substrate 50 and the lower substrate 20 (divided into male and female halves). Once the upper substrate 50 and the lower substrate 20 are stacked together one on top of the other, the desired structures of the hybridization chamber 51 , the first microchannels 54 , and the second circulation holes 53 will be formed. Likewise, the third circulation holes 2011 , 2021 , the second microchannels 2022 , and the fourth circulation holes 2023 are not limited to be located on the top substrate 201 , but they may be located on the bottom substrate 202 , or on both the top substrate 201 and the bottom substrate 202 (divided into male and female halves).
[0065] The biochips can be fabricated by the conventional method. There is no specific limitation on the material, the shape, and the pore size of the porous membrane 30 .
[0066] FIG. 3D is the schematic view showing the flow direction of the hybridization solution according to the third embodiment. With reference to FIG. 3D , before the hybridization reaction, the target nucleic acid solution T is injected into the hybridization chamber 51 from the fourth circulation hole 2023 through the second microchannel 2022 , and then the third circulation holes 2021 and 2011 . After entering the hybridization chamber 51 , the target nucleic acid solution T diffuses into the inside of the porous membrane 30 from the bottom center thereof, and continuously diffuses toward the outer edge of the porous membrane 30 . Some of the target nucleic acid solution T flows in the interspace among the little pillars 511 , and is collected in the interstice 55 surrounding the periphery of the porous membrane 30 . Finally, the target nucleic acid solution T is discharged to the outside via the first microchannel 54 and the second circulation holes 53 which are located on the two sides of the hybridization chamber 51 , and the first circulation hole 52 . If the porous membrane 30 is in a dry state, the target nucleic acid solution T can rapidly enter the inside of the porous membrane 30 due to the capillary attraction of the fine pores of the porous membrane 30 . Moreover, the target nucleic acid solution T which enters the porous membrane 30 can be permanently attached to the surface and the inside of the porous membrane 30 by heating or UV irradiation.
[0067] Afterwards, the nucleic acid probe solution P is injected into the hybridization chamber 51 via the first circulation hole 52 for hybridization reaction. After the nucleic acid probe solution P is added, the added nucleic acid probe solution P will take the same flow path as the target nucleic acid solution T as exemplified in the first embodiment, and distribute over the whole membrane 30 . If the porous membrane 30 is in a dry state before the nucleic acid probe solution P is added, the nucleic acid probe solution P will rapidly enter the inside of the porous membrane 30 . After the nucleic acid probe solution P is added, the biochip is placed at a proper temperature (such as 40 to 48° C.) for several minutes to allow the nucleic acid probe to anneal with the target nucleic acid, and thus the process of base pairing is completed.
[0068] After the process of base pairing, the unhybridized nucleic acid probes are washed away. The washing solution W is flushed into the hybridization chamber 51 from the fourth circulation hole 2023 through the second microchannel 2022 , and then the third circulation holes 2021 and 2011 . When the washing solution W is flushed into the hybridization chamber 51 , the washing solution W diffuses into the inside of the porous membrane 30 from the bottom center thereof, and continuously diffuses toward the outer edge of the porous membrane 30 . Some of the washing solution W flows in the interspace among the little pillars 511 , and is collected in the interstice 55 surrounding the periphery of the porous membrane 30 . Finally, the washing solution W is discharged to the outside via the first microchannels 54 and the second circulation holes 53 which are located on the two sides of the hybridization chamber 51 , and the first circulation hole 52 . Because the washing solution W is flushed from the bottom of the porous membrane 30 to the inside thereof, the nucleic acid probe, which is a relatively small molecule, can be easily and rapidly flushed out of the pores of the porous membrane 30 by the outward diffusion of the washing solution W and the guidance of the interspace among the little pillars. Therefore, the background noise level is reduced, and the time for flushing is shortened.
[0069] FIG. 4A is an exploded view of the biochip of the fourth embodiment of the present invention. With reference to FIG. 4A , the biochip of this embodiment comprises an upper substrate 60 , a lower substrate 20 composed of a top substrate 201 and a bottom substrate 202 , and a membrane 30 , wherein the upper substrate 60 , the top substrate 201 , and the bottom substrate 202 are stacked together one on top of the other, and the porous membrane 30 is provided in the hybridization chamber 61 located on the upper substrate 60 .
[0070] With reference to FIG. 4A to FIG. 4C , the upper substrate 60 has a hybridization chamber 61 , which is in the form of a disk-shaped cavity. However, the shape, the size and the thickness of the hybridization chamber 61 have no restriction, and the hybridization chamber 61 can be a tetrahedral cavity. The hybridization chamber 61 is provided with a first circulation hole 62 . There is no specific limitation on the numbers and the positions of the first circulation hole 62 , and the positions of the first circulation hole 62 can be changed with the position of another circulation hole so that the reaction solution can flow over the whole inside of the porous membrane 30 . In addition, the first circulation hole 62 can be further communicated with a microchannel or another circulation hole (not shown in the drawing) for facilitating solution injection.
[0071] A pair of the first microchannel 64 are respectively communicated with the hybridization chamber 61 , and the pair of first microchannels 64 are further respectively communicated with a pair of the second circulation holes 63 . There is no specific limitation on the number and the positions of the first microchannels 64 , and the number and the positions thereof can be changed with the flow path of the reaction solution. In addition, an interstice 65 with predetermined width is left between the porous membrane 30 and the sidewall of the hybridization chamber 61 . The interstice 65 has a width of 0.05 to 0.2 mm, and preferably 0.1 mm.
[0072] The lower substrate 20 is composed of a top substrate 201 and a bottom substrate 202 , which are stacked together one on top of the other. The top substrate 201 has the third circulation hole 2011 , and the bottom substrate 202 has the third circulation hole 2021 corresponding to the third circulation hole 2011 . The third circulation hole 2011 or 2021 can be provided in a single-layer lower substrate 20 or in a lower substrate 20 composed of a top substrate 201 and a bottom substrate 202 as this embodiment. The third circulation hole 2021 is further communicated with the second microchannel 2022 , and the second microchannel 2022 is further communicated with the fourth circulation hole 2023 .
[0073] With reference to FIG. 4A and FIG. 4B , the hybridization chamber 61 , the first microchannels 64 , and the second circulation hole 63 are formed between the upper substrate 60 and the lower substrate 20 . The hybridization chamber 61 , the first microchannels 64 , and the second circulation holes 63 are not limited to be located on the upper substrate 60 , but they may be located on the lower substrate 20 , or on both the upper substrate 60 and the lower substrate 20 (divided into male and female halves). Once the upper substrate 60 and the lower substrate 20 are stacked together one on top of the other, the desired structures of the hybridization chamber 61 , the first microchannels 64 , and the second circulation holes 63 will be formed. Likewise, the third circulation holes 2011 , 2021 , the second microchannels 2022 , and the fourth circulation holes 2023 are not limited to be located on the top substrate 201 , but they may be located on the bottom substrate 202 , or on both the top substrate 201 and the bottom substrate 202 (divided into male and female halves).
[0074] The biochips can be fabricated by the conventional method. There is no specific limitation on the material, the shape, and the pore size of the porous membrane 30 .
[0075] FIG. 4D is the schematic view showing the flow direction of the hybridization solution according to the fourth embodiment. With reference to FIG. 4D , before the hybridization reaction, the target nucleic acid solution T is injected into the hybridization chamber 61 from the fourth circulation hole 2023 through the second microchannel 2022 , and then the third circulation holes 2021 and 2011 . After entering the hybridization chamber 61 , the target nucleic acid solution T diffuses into the inside of the porous membrane 30 from the bottom center thereof, and continuously diffuses toward the outer edge of the porous membrane 30 . Subsequently, the target nucleic acid solution T is collected in the interstice 65 surrounding the periphery of the porous membrane 30 . Finally, the target nucleic acid solution T is discharged to the outside via the first microchannels 64 and the second circulation holes 63 which are located on the two sides of the hybridization chamber 51 , and the first circulation hole 62 . If the porous membrane 30 is in a dry state, the target nucleic acid solution T can rapidly enter the inside of the porous membrane 30 due to the capillary attraction of the fine pores of the porous membrane 30 . Moreover, the target nucleic acid solution T which enters the porous membrane 30 can be permanently attached to the surface and the inside of the porous membrane 30 by heating or UV irradiation.
[0076] Afterwards, the nucleic acid probe solution P is injected into the hybridization chamber 61 via the first circulation hole 62 for hybridization reaction. After the nucleic acid probe solution P is added, the added nucleic acid probe solution P will take the same flow path as the target nucleic acid solution T as exemplified in the first embodiment, and distribute over the whole membrane 30 . If the porous membrane 30 is in a dry state before the nucleic acid probe solution P is added, the nucleic acid probe solution P will rapidly enter the inside of the porous membrane 30 . After the nucleic acid probe solution P is added, the biochip is placed at a proper temperature (such as 40 to 48° C.) for several minutes to allow the nucleic acid probe to anneal with the target nucleic acid, and thus the process of base pairing is completed.
[0077] After the process of base pairing, the unhybridized nucleic acid probes are washed away. The washing solution W is flushed into the hybridization chamber 61 from the fourth circulation hole 2023 through the second microchannel 2022 , and then the third circulation holes 2021 and 2011 . When the washing solution W is flushed into the hybridization chamber 61 , the washing solution W diffuses into the inside of the porous membrane 30 from the bottom center thereof, and continuously diffuses toward the outer edge of the porous membrane 30 . Subsequently, the washing solution W is collected in the interstice 65 surrounding the periphery of the porous membrane 30 . Finally, the washing solution W is discharged to the outside via the first microchannels 64 and the second circulation holes 63 which are located on the two sides of the hybridization chamber 61 , and the first circulation hole 52 . Because the washing solution W is flushed from the bottom of the porous membrane 30 to the inside thereof, the nucleic acid probe, which is a relatively small molecule, can be easily and rapidly flushed out of the pores of the porous membrane 30 . Therefore, the background noise level is reduced, and the time for flushing is shortened.
[0078] According to polymerase chain reaction (PCR), the annealing of the primer and the target nucleic acid only took one minute to be completed. By using the biochip of the present invention, the nucleic acid probe can effectively diffuse on part of the surface and in the inside of the membrane and forms a base pair with the target nucleic acid in a very short time after the nucleic acid probe enters the hybridization chamber and contacts with the membrane. The hybridization reaction of the present invention only takes several minutes instead of over 10 hours for the prior art. On the other hand, the nucleic acid probe cannot easily stick to the membrane because the nucleic acid probe can form a base pair with the target nucleic acid in a very short time. Therefore, when the washing solution W is flushed into the inside of the porous membrane 30 , the small nucleic acid probe molecules unspecifically bound to the membrane can be easily and rapidly flushed out of the membrane. As a result, the background noise level is reduced. It is also worth noting that the flow directions of the target nucleic acid solution and the nucleic acid probe solution play a very important role in the present invention. Moreover, the structures of the flow-in and the flow-out circulation holes for the target nucleic acid solution T, the nucleic acid probe solution P, and the washing solution W described in the above embodiments are just exemplified, therefore, those are not limited to the described ones.
[0079] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Thus, it is intended that the present invention cover the modifications and the variations of this invention provided they come within the scope of the appended claims and their equivalents. | The present invention relates to a biochip for nucleic acid hybridization. The biochip of the present invention comprises a hybridization chamber which is in the form of a cavity, a porous membrane pressed in the hybridization chamber; and at least one first circulation hole and at least one second circulation hole which are communicated with the hybridization chamber so that the reaction solution flows in the at least one first circulation hole and flows out the at least one second circulation hole through the pores of the porous membrane. The hybridization reaction area is increased by flowing the reaction solution through the pores of the membrane, which enable the reaction sensitivity to be increased. The diffusion distance for the reaction molecules is decreased due to the limited inside space of the membrane, and thereby the hybridization time is shortened. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to the field of pressurized fuel cylinders, and more particularly to means for preventing splashing of liquid into the vapor withdrawal pipe and for stabilizing the pipe.
BACKGROUND OF THE INVENTION
[0002] Propane gas is becoming known as an attractive alternative to the use of conventional gasoline to fuel lawnmowers and other devices. Using propane tanks for lawnmowers eliminates the spillage associated with gasoline use and lessens harmful vapor releases. Propane versions of lawnmowers have been found to significantly reduce ozone-destroying emissions.
[0003] Propane gas cylinders or tanks are generally made from lightweight metals such as aluminum, but may also be made of steel or composite material. Because the cylinders are typically laid on their sides when positioned on the lawnmower, a pipe, runs from the service valve coupling at the top of the cylinder into the interior of the cylinder, and has a bend formed in it to position the open end of the pipe adjacent to the side of the cylinder at or near its uppermost point. This allows the propane vapor enter the pipe and exit through the service valve.
[0004] A significant problem exists in conventional gas cylinders with internal pipes for withdrawing liquid or gas, in that, due to the long lever arm presented by the pipe, vibrations of the pipe can result in significant stresses on the connection of the pipe to the service valve coupling. As a result, the pipe can develop fatigue cracks at the point where it is internally threaded into the service valve coupling. It would be desirable to have at least one brace inside the tank to support the vapor withdrawal pipe to prevent breaking of the pipe, especially in a vibration-prone environment.
[0005] In addition, because the bottom portion of the tank contains liquid fuel, it is important that means be employed to reduce the possibility that liquid fuel splashes into the vapor withdrawal pipe. In prior art uses of horizontal propane tanks in other vehicles, such as in recreational vehicles, the possibility of propane splashes is lessened by the fact that the vehicle is not generally in motion when the propane tank is in use. When horizontal propane tanks are used to fuel moving vehicles, such as lawnmowers, however, the tanks can be expected to operate in uneven or rough terrain in which sloshing and splashing of propane into the vapor withdrawal pipe could be a problem. It would therefore be desirable to have a means for reducing the possibility of splashing liquid entering into the vapor withdrawal pipe of a horizontal propane tank.
[0006] U.S. Pat. No. 5,105,996 (“the '996 patent”) addresses the problem of providing support for a liquid propane fuel pipe inside a horizontal propane cylinder. This prior art invention employs a cylinder made from a top section including a “joggle lip” which mates with the substantially straight rim lip of the cylinder bottom section. A brace member is welded to the joggle. The brace member includes a pair of spaced tines which are spaced apart to allow the liquid pipe to be fitted between the tines. The liquid pipe is secured to the brace prior to assembly of the top and bottom cylinder sections by fitting the pipe between the tines and then crimping the tines together to clamp the pipe in the brace. Once the pipe is secured within the brace, the top and bottom head sections are welded together to form the cylinder. The invention disclosed in the '996 patent thus addresses the problem of providing bracing for a liquid propane fuel pipe, but does not address the problems peculiar to the use of a horizontal propane tank with an internal vapor fuel pipe put to use in an operating environment which would cause splashing of liquid fuel. Further, the '996 patent does not address the need to protect the inlet of the vapor fuel pipe from splashing of liquid propane.
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to provide a pressurized fuel cylinder for supplying fuel vapor to devices that may be operating in rough terrain and therefore be subjected to substantial jolts and vibrations.
[0008] It is another object of the present invention to provide a support apparatus for the vapor fuel withdrawal pipe of a fuel cylinder.
[0009] It is yet another object of the present invention to provide a means for reducing the possibility of liquid fuel splashing into the vapor fuel withdrawal pipe inlet.
[0010] The present invention achieves these objectives by providing a fuel cylinder with a vapor fuel withdrawal pipe that is supported in one or more places by internal bracing and in which a liquid splash guard protects the inlet of the vapor fuel withdrawal pipe from splashing fuel.
[0011] For purposes of summarizing the invention, certain aspects, advantages, and novel features of the invention have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any one particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.
[0012] These and other embodiments of the present invention will also become readily apparent to those skilled in the art from the following detailed description of the embodiments having reference to the attached figures, the invention not being limited to any particular embodiment(s) disclosed.
DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a frontal, partially broken-away view of a gas cylinder employing a brace and splash guard in accordance with one embodiment of the present invention.
[0014] FIG. 2 is a cross-sectional view of the cylinder of FIG. 1 , taken along line 2 - 2 of FIG. 1 , showing a top view of the brace securing the vapor fuel pipe and the splash guard.
[0015] FIG. 3 is a cross-sectional view of one embodiment of the invention taken along line 3 - 3 of FIG. 2 , showing the weld joints securing the brace to the top head joggle lip.
[0016] FIG. 4 is a partial perspective view of one embodiment of the top head section showing the vapor fuel pipe, the brace, and the splash guard.
[0017] FIG. 5 is a partial broken-away view of one embodiment of the brace, showing the brace tines in further detail.
[0018] FIG. 6 is a front view of one embodiment of the splash guard, before it is welded into place.
[0019] Repeat use of reference characters throughout the present specification and appended drawings is intended to represent the same or analogous features or elements of the invention.
DETAILED DESCRIPTION
[0020] The present invention and its advantages are best understood by referring to the drawings. The elements of the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention.
[0021] FIG. 1 illustrates one embodiment of a horizontal fuel gas cylinder 10 that may be used on a propane-powered lawnmower or other gas fuel-powered device. The cylinder 10 is made up of a “top” head section 11 and a “bottom” head section 12 , which sections are secured together by a circumferential weld joint 13 to form a pressure vessel for containing fuel. (Note that the use of “top” and “bottom” head sections refers to the positioning of the cylinder in its traditional orientation, which is the orientation used for filling the cylinder, and not in its horizontal position, i.e., the position of its use.) Both the top head and the bottom head sections may be fabricated from aluminum or aluminum alloy to minimize the weight of the cylinder and to resist corrosion, though other materials could be used as well, such as steel or composite materials. In this embodiment, a guard or collar 14 is welded to the top head 11 in the conventional manner, and a foot ring 15 is welded to the bottom of the bottom head section 12 .
[0022] In another embodiment of the invention, the cylinder is made of a composite material. In the composite embodiment, the head sections are connected together with adhesive.
[0023] Referring to FIG. 1 , the cylinder 10 also comprises a pipe 16 contained within the cylinder 10 . The pipe 16 is made of steel in one embodiment, though other materials could be employed, such as aluminum or plastic. In one embodiment, the pipe 16 is a ⅜ inch steel NPS pipe. One end 17 of the pipe 16 is threaded into a coupler 18 which in turn connects to a service valve 19 . The valve 19 can be used to connect to an engine to provide the fuel vapor for engine operation. The pipe 16 has a bend 20 formed in it to bring the pipe's “open” end 21 adjacent to the side 22 of the bottom head section 12 . In operation, the cylinder 10 is laid horizontally on its side as shown in FIG. 1 , and oriented so that the pipe end 21 is at or near the uppermost point in the cylinder 10 .
[0024] In the conventional manner, the cylinder 10 further includes additional fittings, such as a fill valve, a fill coupling, a float valve to indicate the fuel level and a pressure relief valve. These additional fittings are not illustrated herein.
[0025] To relieve the strain on the pipe 16 due to its long lever arm and the vibration experienced during operation of the lawnmower, a brace 30 is included to secure the pipe in accordance with the present invention. For aluminum cylinders, the brace 30 may be made of ⅛ inch thick aluminum, and in one embodiment is made of 6061-T6 aluminum alloy. As illustrated in FIG. 2 , one embodiment of the brace 30 defines two protruding tines 36 and 38 , which are spaced apart by a sufficient distance (prior to assembly with the pipe 16 ) to just allow the pipe 16 to be fitted between the tines. It is desirable to provide a slot dimension between the tines which is only slightly larger than the outer dimension of the pipe 16 , so that the pipe fits tightly between the tines. This facilitates the clamping of the pipe tightly between the tines, so that the tine compression or crimping is not required to do all the work of securing the pipe in place.
[0026] As is better illustrated in FIG. 3 , in one embodiment a joggle 31 is formed in the top head 11 , and the bottom head 12 is formed with a straight rim 33 . This arrangement permits the brace 30 to be welded to the joggle 31 of the top head 11 prior to the mating of the top and bottom head sections 11 and 12 . The pipe 16 can then be fitted between the tines 36 and 38 of the brace 30 prior to assembling the top and bottom heads 11 and 12 , and the tines squeezed together to secure the pipe 16 in place, as illustrated in FIGS. 2 , 4 and 5 . It will be appreciated that the tines 36 and 38 permit mechanical engagement with the pipe 16 by crimping the tines together into contact with the pipe. In this embodiment, because the brace is typically aluminum, and the pipe is steel, welding the brace 30 to the pipe 16 would be difficult due to the dissimilar materials.
[0027] As illustrated in FIG. 3 , the brace 30 is welded to the joggle 31 of the top head section 11 via weld 32 . In one embodiment illustrated herein, the brace 30 is welded to the joggle 31 by gas tungsten arc welding. For an aluminum cylinder of one embodiment, the welding filler wire found particularly well suited to the purpose for welding the 6061-T6 aluminum brace 30 to the joggle of 5154 aluminum is 4043 aluminum alloy filler wire. This particular filler wire is compatible with the two aluminum alloys, the 6061-T6 and the 5154, yet is a ductile material which provides a strong bond between the brace and the joggle. It is important that good welding techniques be employed to weld the brace to the joggle, such as welding to the ends of the brace and having an ample supply of the filler wire, so that the weld joint is not starved for filler during the welding process, and allowing the weld to spill over slightly at the brace ends. Such good welding techniques should be employed to prevent cracking of the weld due to the vibration experienced during operation of the lawnmower or other device.
[0028] Advantages of the brace 30 described above include the securing of the pipe 16 against vibration, thereby reducing the stress on the pipe and reducing stress failure rates, while fulfilling the requirement (applicable to metal cylinders) that no welding can be done to the straight sides of the cylinder. Further, the brace secures the pipe in a rugged and inexpensive manner even when the pipe and the brace are of dissimilar materials which cannot readily be welded together. While the brace disclosed herein is clamped onto the pipe by crimping the tines, and such method is particularly advantageous because of its simplicity, low cost and ruggedness, other mechanical means of connecting the brace to the pipe could alternatively be employed, such as inserting the pipe through a hole in the brace element. In embodiments of the invention in which the cylinder is fabricated from composite materials, the brace is glued to the inner surface of the cylinder rather than welded.
[0029] As illustrated in FIGS. 1 , 2 , and 4 , the cylinder 10 includes splash guard 40 , which is attached to the interior surface of joggle 31 of the top head section 11 as shown in FIGS. 2 and 4 . The attachment of the splash guard, accomplished for metal cylinders by welding of the splash guard 40 to the joggle 31 of the top head 11 , takes place prior to the mating of the top and bottom head sections 11 and 12 . In one embodiment, the splash guard 40 , further illustrated in FIG. 6 , is a roughly rectangular or oblong aluminum sheet 44 containing aperture 41 . Although the aperature is illustrated in FIG. 6 as a round hole, other shapes of apertures, such as oval or slotted, are also within the scope of the present invention. Further, other shapes of splash guards, such as circular or oval, are possible without departing from the scope of the present invention.
[0030] In the embodiment illustrated in FIG. 2 , the sheet 44 is bent or curved as shown and fitted over the pipe 16 in such a manner that the pipe 16 is fed through the aperture 41 of the splash guard 40 . In one embodiment, the splash guard 40 is welded to the joggle 31 via two welds 42 at the distal ends of the splash guard 40 . In composite cylinders, the splash guard is attached to the interior surface of the cylinder via adhesive.
[0031] After the brace 30 , pipe 16 and splash guard 40 are installed to the top head section 11 , as described herein, the top head section 11 is mated to the bottom section 12 in the conventional manner. In one embodiment, the completed fuel cylinder is approximately one foot in inside diameter by about twenty-eight (28) inches in length.
[0032] Although the illustrated embodiment is a fuel cylinder designed for horizontal use, other orientations and shapes of fuel tanks could also employ the present invention, provided that the tanks have a fuel vapor withdrawal pipe internal to the cylinder.
[0033] This invention may be provided in other specific forms and embodiments without departing from the essential characteristics as described herein. The embodiment described is to be considered in all aspects as illustrative only and not restrictive in any manner.
[0034] As described above and shown in the associated drawings and exhibits, the present invention comprises an improved pressurized fuel cylinder. While particular embodiments of the invention have been described, it will be understood, however, that the invention is not limited thereto, since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. It is, therefore, contemplated by the appended claims to cover any such modifications that incorporate those features or those improvements that embody the spirit and scope of the present invention. | A fuel cylinder for use in fueling vapor-powered machines and devices is claimed. The fuel cylinder contains a fuel vapor withdrawal pipe that bends upward towards the top edge of the cylinder when the cylinder is in its position of use, for example, the horizontal position if the tank is used horizontally. A liquid splash guard surrounds the inlet of the fuel vapor withdrawal pipe to protect the inlet from splashing of liquid propane in the cylinder. A brace connects to the fuel vapor withdrawal pipe to stabilize the fuel pipe during high vibration use. In one embodiment, the splash guard and brace are welded to the internal surface of a joggle in the rim of the upper head portion of the cylinder before the upper head portion and lower head portion of the cylinder are mated and welded together. | 5 |
RELATED APPLICATION
This application is based on provisional application Ser. No. 60/197,189, filed Apr. 14, 2000.
FIELD OF INVENTION
The invention relates to lift systems for raising and lowering window blinds which have a cord lift system such as pleated shades, roman shades and venetian blinds.
BACKGROUND OF THE INVENTION
Venetian type blinds have a series of slats hung on ladders which extend from a headrail to a bottomrail. In most venetian blinds a pair of lift cords is provided each having one end attached to the bottomrail and then passing through elongated holes in the slats up to and through the headrail. When the lift cords are pulled downward the blind is raised and when the lift cords are released the blind is lowered. A cord lock is usually provided in the headrail through which the lift cords pass. The cord lock allows the user to maintain the blind in any desired position from fully raised to fully lowered. Pleated shades and roman shades are also raised and lowered by lift cords running from the bottom of the shade into a headrail. The cord lock system and other cord lift systems used in venetian blinds can also be used in pleated shades and roman shades.
Another type of lift system for window blinds utilizes a take-up tube for each lift cord. These tubes are contained on a common shaft within the headrail. Each lift cord is attached to one end of a tube. The tubes are rotated to wind or unwind the lift cord around tubes. This system is generally known as a tube lift system. One problem with tube lift systems of the prior art is that the tube may rotate faster than the cord is pulled away from the tube during lowering of the blind. This can occur when one end of the blind is prevented from moving downward as happens when the blind hits a piece of furniture that is too close to the window. That will cause the cord to bunch and often become tangled within the headrail. When this occurs it is usually enough to help the bottomrail with your hand to the bottom most position and then operate again. However, sometimes it is necessary to remove the blind from the window and untangle or replace the tangled lift cord. This is especially true when the capstan has a cone shape. There is a need for a tube lift system which is easy to operate and which will prevent the lift cords from becoming tangled when the blind is raised and lowered.
A second problem with tube lift systems arises from the fact that the diameter of the lift cords can vary by as much as five thousandths of an inch and the diameter of the tube or spool on which the lift cords are wrapped can vary by four thousandths of an inch. If a blind has two lift cords, each cord having a different diameter and each spool on which a lift cord is wound having a diameter different from the other spool, then it is possible that one lift cord will end up being longer than the other lift cord when the blind is lowered. This difference can be as much as one half to three fourths of an inch when the blind is fully lowered. Consequently, the bottomrail is noticeably slanted or uneven. Prior to the present invention the art had found no good solution to this problem. One solution was to shorten the cord which was longer when the blind was fully lowered so that the bottomrail appeared to be even when the blind was fully lowered. However, when that was done the bottomrail was slanted in an opposite direction when the blind was stacked. Another solution was to replace the lift cords. Depending upon how close the diameters of the replacement cords were to one another, this may or may not have been an improvement. Whatever the solution, the shade had to be disassembled and restrung. Consequently, there is a need for a cord lift system for blinds which can be adjusted to compensate for differences in diameters of lift cords and spools on which they are wound.
SUMMARY OF THE INVENTION
I provide a lift system for blinds of the type having at least one pair of lift cords for raising and lowering the blind. I prefer to provide a conical cord collector or cone for each center lift cord or each pair of lift cords that pass over the edge of the slats. I prefer that the cone be threaded. In an edge lift cord system two lift cords will lie side by side when wrapped around the cone. An axle passes through each externally threaded cone so that rotation of the axle will rotate the cones and the cones may slide along the axle or the axle will traverse the headrail. I prefer that the cones have a frusto-conical shape. I further prefer to provide a cover that surrounds at least a portion of each cone. This cover may be internally threaded. Optionally a drive wheel is positioned adjacent the cone which engages a lift cord as that lift cord is unwrapped from around the cone. The drive wheel is literally fixed relative to the headrail so that it is always adjacent where the lift cord enters the headrail space. At least one cone can be adjusted laterally and radially relative to the axle and the other cones so that the lift cord can effectively start wrapping on any diameter of the cone.
Other objects and advantages of the present invention will become apparent from a description of the present preferred embodiments shown in the drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a rear perspective view partially cut away of the present preferred embodiment of my lift system on a pleated shade shown in a near fully lowered positioned.
FIG. 2 is a sectional view taken along the line II—II of FIG. 1 .
FIG. 3 is an enlarged view of a present preferred cone used in the embodiment shown in FIG. 1 .
FIG. 4 is a sectional view taken along the line IV—IV of FIG. 1 .
FIG. 5 is a rear perspective view of one end of the headrail partially cut away which contains a second present preferred embodiment of my lift system.
FIG. 6 is a perspective view of a conical cord collector and cover portion of a third present preferred embodiment of my lift system.
FIG. 7 is a perspective view of a portion of the lift system similar to that shown in FIG. 1 which utilizes a threaded axle and locking nuts with a position indicator.
FIG. 8 is a top plan view of the drive wheel in engagement with a portion of a conical cord collector.
FIG. 9 is a top plan view of another present preferred embodiment of my lift system.
FIG. 10 is a front view of a venetian type blind containing another present preferred embodiment of my lift system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first present preferred embodiment of my lift system is contained in a headrail 2 , with endcaps 3 shown in FIG. 1 . That lift system can operate a pleated shade 28 shown in FIG. 1 or other window covering attached to the headrail. The lift system has a central axle 5 which is turned by pulling cord loop 10 . One could provide an electric motor to turn the axle. The axle is carried on brackets 6 . As shown in FIG. 9, I prefer to provide threads 12 at one end of the shaft 5 . If desired one could use a release brake of the type disclosed in my U.S. Pat. Nos. 5,791,393 and 5,927,370 to turn the axle. That release brake is indicated by the box 13 in dotted line in FIG. 4 . As can be seen in FIG. 1, each lift cord 9 is wound on a conical cord collector or cone 8 .
As shown most clearly in FIG. 3, I prefer that each cone have a series of stepped or threaded diameters 7 with the width of each step or thread being approximately the diameter of a standard lift cord, namely, 0.9 to 1.4 mm. As the lift cord 9 is wound about the cone the cord wraps on decreasingly smaller diameters of the cone. Referring to FIGS. 1 and 2, I further provide a guide wheel 16 carried on arm 17 . The lift cord 9 enters the headrail 2 through an eyelet 18 . The cord 9 is pressed against cone 8 by guide wheel 16 . A preferred wheel 16 shown in FIG. 8 has a rim 19 that presses the cord 9 against the cone 8 keeping the cord in a correct position. A spring 15 keeps the guide wheel 16 against the cone 8 . A clutch could also be provided. As the axle 5 is turned either the entire axle and attached cones move left or right within the headrail or the cones move left or right along the axle depending upon the direction in which the axle is rotated. The axle could be threaded at one end as shown in FIG. 9 to enable the axle to move or threaded at locations carrying cones to enable the cones to move on the axle. One could also provide a smooth shaft and allow the wrap of the cords to advance the cones along the axle. This movement presents a changing cone diameter to the guide wheel. Consequently, no two full rotations of the axle will wind or unwind the same length of cord.
An important advantage of the guide wheel arises from the wheel being driven by the cone as the blind is being lowered and by the cord as the blind is being raised. That means that the wheel will turn faster than the cord when it is being unwound from the cone and the blind is being lowered and at the same speed as the cord when the blind is being raised. This action drives the cord from the cone through the eyelet 18 and out of the headrail. Consequently, if the cone keeps turning while downward movement of the blind is obstructed, the excess cord is likely to be expelled from the headrail where it is less likely to tangle and easier to untangle.
In a standard tube lift the lift cord is wound about a cylindrical tube or cylindrical axle. Consequently, each rotation of the axle will collect or release a length of cord equal to the circumference of the tube which can be calculated from the equation L=πdw where d is the outside diameter of the tube plus the radial diameter of the cord as it wraps on the tube and w is the number of wraps. In blinds for standard residential and commercial windows the axle may rotate 40 or more times to fully raise or lower the blind. All window blinds that have lift cords will have at least two lift cords and each lift cord is wound on a separate portion of the tube or has its own spool. Although all tubes are supposed to have a consistent diameter, one portion of a tube is often larger than the other portions with differences in diameters being as much as 0.005 inches. The cord diameters can also vary by up to 0.005″. Since the spool will rotate about forty times to fully lower the blind, that means one lift cord could be lowered 0.4 inches more than the other lift cord. Hence the bottom of the shade will appear to be tilted.
In the present lift system the total length of lift cord that will be released is determined by the equation:
L=Σπd A w
wherein d A is the average diameter of the cone over which the cord winds and the diameter of the cord. Average diameter on a cone equals the largest diameter and the smallest diameter divided by two. It is desired to have the length L constant. The number of wraps will be the same for all of the cones since they are on the same axle. Therefore, the average diameter of the cone and the cord needs to be equal from cone to cone. Since the cones are likely to vary slightly from part to part and the cord diameters will also vary the average diameter d A can be equalized by adjusting the starting or largest diameter that cord begins wrapping on.
Because a cone offers a series of different diameters a fabricator can position the cones on the axle so that the lift cords begin wrapping at slightly different locations on the cones. Consequently, the fabricator can compensate for variations among cones and cords. The result is that every blind can be fabricated so that the bottom of the blind is level when the blind is fully lowered. The fabricator can adjust the position of the cord simply by rotating the cone relative to the axle and advancing it relative to the axle. For example, suppose the cone is shaped so that each thread is 0.030″ smaller or larger than the adjacent thread and that there are two cones used in the blind. Also suppose that one cone′ is 0.005″ smaller in diameter than the other and also that the cord wrapping on that cone is 0.005″ smaller in diameter. If the cords were started in exactly the same spot on both cones then L′=Σπd′ A w<L=Σπd A w because d′ A would be 0.010″ smaller than d A . Rotating either cone 120° or 1/3 of a wrap and advancing it 1/3 of the travel of one thread would compensate for the difference and L=L′.
I prefer to provide a cover that surrounds the cone as shown in FIGS. 5 and 6. The cover may be a rectangular or cylindrical housing 20 which fits around and is spaced apart from the cone as shown in FIG. 5 . Alternatively, the housing 22 may be frusto-conical and have interior threads or shoulders 23 which match the stepped diameters 7 of cone 8 such as shown in FIG. 6 . In the event that an obstruction prevents the bottom of the blind from falling, axle 5 may continue to turn. Should that happen, the lift cords would continue to unwrap from the cone. Since there is no force pulling the lift cord from the headrail the excess cord will remain in the cover in the headrail. If there are no covers that excess lift cord could easily get caught on a bracket or other structure in the headrail. Additionally, the excess cord could become tangled on itself forming a “nest” of cord within the headrail. It is then necessary to open the headrail to untangle the lift cords. Sometimes the lift cords must be replaced. The covers shown in FIGS. 5 and 6 overcome this problem by capturing the unwinding cord. In limited tests I have found that should a blind encounter an obstruction when descending thereby creating unwound cord in the headrail, the problem can be corrected by removing the obstruction and fully lowering the blind. It is not necessary to open the headrail or replace the cords. A partial cover may also be used. One such partial cover would appear like segment 21 of cover 22 shown in dotted line in FIG. 6 . The segment may be fixed to prevent transverse movement but be able to move radially toward and away from the cone.
In yet another embodiment of the lift system shown in FIG. 7 the cone 8 is held on a threaded axle 30 . Lock nuts 31 and 32 are provided on the axle 30 at either end of the cone 8 to retain the cone in a desired location. One could also use a threaded collet and nut or a simple spring clutch between each cone and a corresponding fixed collar on a non-round axle. In FIG. 7, I provide a series of spaced apart marks 34 on nut 32 . I further prefer to provide a longitudinal reference line 35 on shaft 30 . This line could be a groove cut in the threads. When the blind is initially fabricated the cone 8 is positioned so that the zero line 36 is aligned with reference line 35 . If it is necessary to adjust the position of the cone 8 , a fabricator can turn nut 31 a distance that can be measured by the markings 34 on nut 32 . Of course, if nut 32 is turned, nut 31 would be turned an equal amount to prevent slippage of the cone 8 along the axle 30 .
Another embodiment of my lift system shown in FIG. 9 has two axles. The first axle 40 contains a cone 48 . The second axle 42 contains a collection spool 44 . Both axles are held within the headrail 2 on brackets 43 . Only the cylinder axle is powered with a drive mechanism 41 that can be operated with a cord loop, wand or pull cord (not shown). The cones and axle are rotated by the cords. The lift cord 8 wraps around a selected diameter of the cone 48 and then is collected on spool 44 . In the event that the bottom of a blind is not level when the blind is fully lowered, the fabricator can shift one of the cones 48 so that the lift cord leaves the spool at a different diameter. Consequently, the path of one lift cord over a cone onto a spool will be longer than the same path of another cord. If desired the lift cord may make multiple wraps around the cone 48 before moving onto the spool 44 .
In all of the lift systems illustrated in FIGS. 1 through 9 there has been a single lift cord at each cone location. The present lift system is not limited to such blinds but can also be used in a blind having pairs of lift cords such as the venetian blind shown in FIG. 10 .
In such a blind, lift cords are positioned near either end of the blind in slots on both the front and rear edges of the slats. In the embodiment of FIG. 10 four lift cords extend from the bottomrail (not shown) through the headrail. Lift cords 81 and 83 extend from the bottomrail through slots 67 in the front edge of slats 66 . Lift cords 82 and 84 extend from the bottomrail through slots in the rear edge of slats 66 . Each pair of lift cords 81 , 82 , 83 and 84 pass through the headrail 2 . Each pair of lift cords 81 , 82 or 83 , 84 are directed through the headrail over an eyelet 68 onto a cone 8 on axle 54 provided in the headrail. Each pair of cords is wrapped side by side on each stepped diameter of the cone 8 .
A lateral tilt mechanism is provided to move the rails of the tilt ladder 50 relative to one another to open and close the blind. The tilt mechanism in the preferred embodiment is comprised of a strap 58 to which the rails of the tilt ladder 50 are connected. This type of lateral tilt system is disclosed in my U.S. Pat. No. 5,778,956. The strap 58 is carried on pulleys 59 . A handle 55 is turned to open and close the blind. The handle 55 is connected to a gear box 53 that operates an end pulley at the gear box. Turning wand 55 causes the end pulley 59 to turn and move the strap. Movement of the strap 58 in either direction lifts one rail relative to the other to open and close the blind.
Although I have shown and described certain present preferred embodiments of my venetian blind it should be distinctly understood that the invention is not limited thereto but may be variously embodied within the scope of the following claims. | An axle driven cord collection system that uses cones to spool the lift cords. An idle/drive wheel on each cone prevents the cords from tangling. A collet connects each cone in an adjustable way so that the total travel of each cord can be precisely controlled by adjusting the position of the starting wrap on at least one of the cones. | 4 |
FIELD OF THE INVENTION
This invention relates to an electron beam exposure system utilizing a shaped-electron-beam which is vector scanned within a sub-field and an electrical raster scan system for positioning sub-fields over a large rectangular area, and a continuously moving mechanical system for writing large patterns. More particularly it relates to a pattern writing system with a steered electron beam. This invention also relates to registration systems for accurately determining the target position relative to the electron beam position.
DESCRIPTION OF RELATED ART
U.S. Pat. No. 4,467,170 of Hata et al for "Electron Beam Drilling Apparatus" includes a system to control beam deflection to compensate for workpiece movement. The system uses an electron beam for drilling a continuously moving workpiece. See FIG. 4 of Hata et al. There is no registration cycle using the E-beams to check registration marks on the surface of the workpiece.
Commonly assigned U.S. Pat. No. 4,477,729 of Chang et al for "Continuously Writing Electron Beam Stitched Pattern Exposure System" describes a vector scanned E-beam exposure system for writing patterns on a substrate. It includes a continuously moving x-y table, and a laser interferometer control system. Workpiece movement commands are embedded within the pattern defining data to control relative movement between the workpiece and the writing field with respect to movement direction, velocity, and acceleration. Measurement of workpiece location is made by means of two axis laser interferometry, Col. 3, lines 56-59. No suggestion of measurement of the location of registration marks on the workpiece with an E-beam is suggested. Thus the deviation between the position of the workpiece on the table and the location of patterns on the workpiece deviating from the desired location is not taken into account. Only registration marks located on the workpiece within the area to be exposed can provide the desired registration information.
U.S. Pat. No. Re. 31,630 of Goto et al for "Electron Beam Exposure System" shows a shaped beam and a continuously moving table. The amount of workpiece shift is approximated by means of x and y laser interferometers which detect the position of the table, but no reregistration of the workpiece is provided. See Col. 2, lines 33-50.
U.S. Pat. No. 4,063,103 of Sumi for an "Electron Beam Exposure Apparatus" describes an E-beam exposure system with laser interferometry to control x-y table movement.
U.S. Pat. No. 3,900,737 of Collier et al for "Method and Apparatus for Positioning a Beam of Charged Particles" describes and E-beam system with continuously moving x, y table. At Col. 6, lines 51-56, Collier et al states as follows:
"Prior to exposure the exact alignment of the beam scan with respect to the table 21 is carried out by temporarily operating the exposure system as a convention scanning electron beam apparatus. During this latter mode of operation, the electron beam is controlled to scan the fiducial marks."
The system does not reregister the workpiece during operation but makes an assumption from Col. 6, lines 32-44, as follows:
"In addition, precise operation of the overall system presupposes an electron beam characterized by excellent short-term positional stability. As a practical matter, such stability of the beam is achievable in a well-engineered electron column (for example, one of the type disclosed in the above cited Lin application). But it is important to monitor and correct for any long-term drift of the electron beam stemming from, for example, electrical or thermal effects. Illustratively, this is done by periodically interrupting the aforedescribed exposure process and moving the table 21 to precisely determined positions. When the table is so positioned, the relatively stable beam can be expected to be directed approximately at preformed topographical features marked on the surface of the table (for mask fabrication) or on the surface of the wafer itself (for device fabrication). Illustrative registration or fiducial marks 65 through 68 are shown in FIG. 1."
Thus the table must be stopped and moved to align the E-beam with the fiducial marks and that involves the delay which is intended to be avoided by means of this invention while using the system of continuously driving the table supporting the workpiece.
U.S. Pat. No. 4,544,846 of Langner et al for "Variable Axis Immersion Lens Electron Beam Projection System", (commonly assigned) describes an E-beam system with a variable axis immersion lens (VAIL) (referred to below).
U.S. Pat. No. 3,900,736 of Michail et al for "Method and Apparatus for Positioning a Beam of Charged Particles" (commonly assigned) describes an E-beam exposure system with a computer driven correction system for use with a four corner registration system. The correction system operates dynamically to correct the deflection of an electron beam to minimize the deviation from desired alignment. Such alignment problems are caused by factors including the deviation of the position of the registration marks from their design positions.
The Hontas system of E-beam exposure employed by Michail et al has heretofore employed a step-and-repeat method of performing the tasks of registration, writing and transporting of the workpiece to expose each field of a multi-field pattern on a workpiece. Heretofore, the Hontas step-and-repeat system has employed an A cycle, a B cycle and a C cycle. During the A cycle, the workpiece has been registered while the workpiece on the transporting table was at rest. Then the B cycle has followed, during which time the pattern to be exposed has been written by the E-beam, while the workpiece and the table still remained at rest. Finally, only in the C cycle, has the table supporting the workpiece moved along its time consuming trip to the next location for exposing the next field on the workpiece.
The MEBES system provides continuous mechanical motion of the worktable supporting the workpiece, but it does not reregister the workpiece with respect to the E-beam during the process of exposing the entire workpiece. This has the advantage of speed since the reregistration steps are eliminated with the risk that the alignment of the workpiece and the E-beam deviates significantly from the desired alignment.
A problem with previous E-beam exposure systems has been that they either did not employ frequent registration of actual chip position, as with MEBES; or that if they did employ reregistration of chip position as with HONTAS, they required the system to stop in a step-and-repeat type of hesitation sequence. For example, the MEBES system employs a dead-reckoning type of positioning system with a continuous drive system with no reregistration checks during the process of E-beam exposure, with the assumption that the errors between the actual and desired location of patterns on the workpiece will be acceptable because tolerance requirements will be satisfied. The lack of frequent measurements of position in a dead reckoning type of system with continuous motion leads to a problem of alignment of the successive stages of exposure in a multilayer E-beam exposure system. The step-and-repeat system involves stopping the table carrying the workpiece to be exposed for registration and exposure or writing cycles, which requires extensive periods of time for stopping and starting the table. That start-stop time can be approximately equal to the time required to make the exposures.
With the tighter tolerances and smaller dimensions of VLSI chips being designed today, periodic reregistration to the workpiece and the E-beam position are becoming an essential feature of systems. With the economic pressures of high costs of manufacturing equipment and time delays required for E-beam exposure it is essential to maximize throughput of an E-beam system. Thus it is desirable to avoid the step-and-repeat system of exposure, to make the E-beam system more competitive with alternative technologies and to reduce overall costs of manufacture towards and optimum level.
SUMMARY OF THE INVENTION
Heretofore, it has been thought that the work table must be stopped for the purpose of reregistration of the workpiece, which has required a considerable time to start and stop the work table which is massive and accordingly has a long period of inertia in starting and stopping. Moreover, additional time is required for damping out of the overshoot and undershoot in table speed on reinitiating the operation of the drive system to a steady state. These factors greatly delay the operation of such a system.
Accordingly, an object of this invention is to provide a system for E-beam exposure which can perform the process of moving the workpiece simultaneously with the processes of registration of the workpiece and writing on the workpiece, so that the step-and-repeat type of delays of the table supporting the workpiece can be avoided and the errors inherent in a dead-reckoning type of system will be avoided.
In accordance with this invention, a system is provided for providing an electron beam system with a continuously moving table combined with means for registration of the workpiece relative to the electron beam system.
This invention relates to an electron beam exposure system utilizing a shaped-electron-beam which is vector scanned within a sub-field in combination with an electrical raster scan system for positioning sub-fields over a large rectangular area in combination with a continuously moving mechanical system for writing large patterns with a minimum of interruption. More particularly, it relates to a pattern writing system with a steered electron beam. This invention also provides a registration system using the electron beam to determine the target position accurately relative to the electron beam writing system.
In accordance with this invention, the system preferably employs writing of lithographic patterns with a shaped electron beam exposure system which minimizes the time wasted by workpiece positional requirements. Large lithographic patterns are written with subpatterns in sub-fields in a vector writing mode without interruption between successive sub-fields. This is made possible by continuously moving the workpiece in combination with the writing capability of a large rectangular writing field. The writing field contains a rectangular array of electronically positioned sub-fields which are written in a raster sequence. The large width of the writing field provided by the VAIL system reduces the number of mechanical scans required to write the pattern on the workpiece which further reduces the time required by workpiece positioning. The continuous velocity of the continuously moving workpiece during Y axis scans along a column on the wafer is corrected during writing to compensate for pattern density, maintaining an optimum workpiece position relative to the writing field. When patterns are being superimposed over previously written patterns, a means of registration is required since processing can cause workpiece distortions that are not detectable by position measurement systems. Accurate positioning of the overall workpiece relative to positional measurement systems is impractical due to thermal effects and other error sources. This system includes a registration field confined to local areas on the workpiece, which is larger than the writing field, which can be used for registration, without requiring a height-related change in focus and without requiring the mechanical system comprising the X-Y work table to change speed during the registration and reregistration of the various fields on a semiconductor wafer. The registration field can be larger than the writing field, because the quality requirements demanded from the shaped-electron-beam are less for detecting the locations of such registration marks at the various locations on the wafer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the electron beam exposure system showing the general details in accordance with this invention.
FIG. 2 is a plan view of the workpiece showing the relationships of the registration and writing strategy.
FIG. 3 illustrates the workpiece registration field and the pattern writing field employed in accordance with this invention.
FIG. 4 shows a detailed block diagram showing the details of the velocity and position control and monitoring system.
The foregoing and other objects, features and advantages of the invention will be apparent from the more particular description of the preferred embodiments of the invention which follows.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In accordance with this invention, a large lithographic pattern is written as quickly as possible by writing sub-field patterns in a vector scan mode. The sub-fields are positioned with a large field deflection system in combination with a continuously moving workpiece. This rectangular array of sub-fields provides several advantages which reduce the total time required to expose the workpiece (i.e. wafer or mask). The large field deflection capability provides registration capability on sparsely located registration marks by using the beam as a probe to locate the target fields accurately relative to the deflection systems. The advantages over prior art are:
1. A wide strip of sub-fields is written for each pass of the wafer, thus minimizing the number of passes required and the time required for reversing the work table motion and repositioning.
2. The large field deflection system provides the capability of positioning the sub-fields in a rectangular array thus providing a time buffer for dense and sparse patterns in the sub-fields. This capability reduces the velocity change requirements for the continuously moving work table.
3. Registration capability provides a more precise superposition of the written pattern over existing lithography.
FIG. 1 generally illustrates a preferred embodiment of this invention. Referring to the E-beam writing process employed in accordance with this invention, continuous mechanical motion of the X-Y work table 8 beneath the E-beam B. The motion is generally provided along a serpentine, boustrophedontic path, as the oxen plow from one end of a column to the next column along the "Y" axis. Thus, the continuous motion occurs along one axis herein defined as the "Y" axis, whereas the motion at right angles to the X axis, at the end of each column, occurs as a step function at the end of each Y axis excursion in the direction referred to herein as the "X" axis. An E-beam exposure system is indicated generally by the phantom line 10. E-beam source 11 produces a beam B which is shaped into various spot shapes and blanked by the deflection and aperture apparatus 12, under the control of spot shaping apparatus and blanking apparatus, both located in unit 14 in accordance with Michail et al U.S. Pat. No. 3,900,736 cited above. The positioned and shaped spot is controlled, in part, by spot shaping, blanking analog electronics unit 14 under the control of digital electronics in pattern control section 15. This determines the pattern written in the sub-field under control of the control computer 16, as in Michail et al above. Pattern control section 15 supply signals on line 64 to unit 14. The shaped beam is vector positioned by the deflection apparatus 13 under the control of vector deflection apparatus 33. After each sub-field is completed the next sub-field is positioned by the large field deflection apparatus 17 under the control of large field deflection system 19. Pattern control section 15 supplies signals on line 66 to control deflection system 19. Preferably the large field deflection apparatus 17 incorporates a Variable Axis Immersion Lens arrangement as described in Langner et al U.S. Pat. No. 4,544,846. That arrangement permits the beam B to be deflected farther from the axis of the electron beam column to provide a large range writing capability.
The next sub-field is positioned orthogonally with respect to the direction of motion of the X-Y drive work table 8 which supports the workpiece 7 which is shown as a semiconductor wafer. However, at the edge of the writing field the exception is that the sub-field is positioned normally (or at right angles) with the direction of motion. The result of this sub-field positioning scheme in combination with a continuously moving work table 8 is a continuously moving, boustrophedontic raster scan. The raster scan positioning of the sub-fields is controlled by the large field deflection control system 19 containing electronic circuitry and pattern data from pattern control section 15. A motion compensating signal on line 20 from stage (work table) position measurement system 21 is received by large field deflection system 19 from the laser stage (work table) position measurement system 21. Measurement system 21 preferably directs a pair of laser beams at two edges of the work table 8 to measure table position as will be understood by those skilled in the art. The laser beams are omitted from the drawing to minimize confusing detail. Electronics in system 19 provide signals to the deflection apparatus 17 to compensate for X, Y, and angular errors resulting from the continuous motion of the work table 8 while sub-fields are being written.
The writing of patterns is temporarily stopped, typically after writing at a chip position on wafer 7 has been completed, and a reregistration cycle on wafer 7 is initiated. In the preferred embodiment, the beam B is deflected to the nominal location of four registration marks for the next chip on wafer 7 and four areas are scanned by the E-beam to probe the four areas. The actual positions of the registration marks (such as marks 39 in FIGS. 2 and 3) are detected by backscattered electrons which strike detectors 22. The signals from detectors 22 are fed on lines 27 and 28 to registration detection circuits 23 to determine the actual next chip position which provides a signal on lines 60 and 61 to pattern control section 15, and on lines 60 and 62 to the control computer 16. The designed chip position is supplied from control computer 16 on line 63 to the pattern control section 15. In pattern control section 15, the values on lines 63 and line 61, i.e. the designed chip position and the actual chip position, are compared, and corrections are applied on line 65 to the vector deflection apparatus 33. The registration cycle is alternated with writing cycles until the X-Y work table 8 arrives at the edge of the workpiece 7 which is a semiconductor wafer or mask. The work table 8 is moved along the X axis and the direction of motion in the Y axis is reversed starting the reregistration and writing cycles for the next column of chips. An alternate embodiment of the invention provides a two mark registration cycle with pairs placed more often on the edge of the writing field.
The X-Y mechanical drive work table 8 for moving the chip horizontally under the E-beam is controlled as follows. The X axis work table positioning is controlled by an X position signal included in an X/Y position signal on line 24 from control computer 16 to stage position measurement system 21. The signal on line 24 is predetermined by wafer specifications stored in the form of position control data in control computer 16 as modified by current registration signals received via lines 60 and 62 from registration detection circuits 23. The actual X position of work table 8 is determined by (laser) stage position measurement system 21 and that value is compared to the desired X position signal on line 24 from control computer 16. A resulting position error signal on line 25 is applied to a servo apparatus in the X stage drive mechanism 26 which applies a drive signal to motor 67 by lines omitted for convenience of illustration, as well known in the art. The Y table velocity and position control system 29 utilizes
(1) a predetermined course velocity control signal on line 18 from control computer 16,
(2) a laser LSB signal on line 30 from measurement system 21 which is used for determining actual table velocity, and
(3) a sub-field position completion signal on line 31 from pattern control section 15 for determining velocity corrections.
A velocity control (position error) signal on line 6 from the control system 29 is applied to Y stage drive mechanism 35 which applies an input to control Y axis drive motor 9 by lines omitted for convenience of illustration. After a single scan of a column of chips is completed, the Y axis of the work table is positioned utilizing the methods described for X axis positioning by using the x/y position signal on line 34 and a position error signal on line 6. During this time between scans, the velocity control signal in the Y direction will be zero for an interval while the x-axis drive motor 67 moves the work table 8 to the next row. This is necessary since the scan is a serpentine scan in which the x-axis drive motor 67 is held still or halts its motion temporarily until the y drive motor 9 has reached the end of a row. Then, the y drive motor 9 remains still until the x drive motor 67 moves the work table 8 to the next row. Then the scan is continued for the new row in the opposite direction from the previous scan. A more detailed description of the Y axis table control system 29 follows below in connection with FIG. 4.
FIG. 2 further illustrates and clarifies the writing method employed in connection with this invention. The E-beam B is shown directed to a chip site C1 on wafer 7. The E-beam B exposes one chip at a time moving along the path from chip site C1, to chip site C2, to chip site C3, to chip site C4 as indicated by the dotted line path. The exploded view of a chip C2 in the circle on the upper left shows the chip site C2 with a large registration field RF with four registration points 39 and a writing field WF, which is a narrow stripe only 10 mm wide for a series of sub-fields on the chip site C2. The registration field RF is also known as a field comprised of a number of sub-fields SF, some of which are shown as squares within the writing field WF. The writing field WF and the registration field RF are covered by the large field deflection of the VAIL system. The direction of table movement TM is to the upper right. The exploded square SF indicates that sub-field vector writing is employed in accordance with the HONTAS system as described in the Michail et al patent, above. Spots SP are shown to illustrate the spots written by a conventional Hontas system.
FIG. 3 further illustrates the registration method employed with this invention, and the relative size of the registration deflection area 36 (i.e. registration field RF), and the writing deflection area 37 (i.e. writing field WF). The chip area 38, with its four corner registration marks 39, is also shown. Although the writing deflection area 37 is not capable of covering the complete chip area 38, it is seen that the registration deflection area 36 is larger than the chip area 38 and can reach the registration marks 39 in each of the four corners. The registration deflection area 36 can be larger than the writing deflection because the requirements on the spot edge acuity are less for the detection of registration marks than for pattern writing (larger deflections have inherently more spot distortion than smaller deflections). In the writing sequence, during the registration step the deflection of the beam B expands beyond area 36 to reach out to measure the location of the four registration marks 39, the field dimension are adjusted, so that, as the continuously moving table 8 brings the chip area 38 under the range of the writing deflection that the pattern being written has the proper translations and size to overlay the underlying pattern on the chip 38.
FIG. 4 shows the detailed schematic diagram of control system 29 which operates the table 8 with continuous motion in accordance with this invention. Referring to FIG. 4, a course velocity control signal is received on line 18 from the control computer 16 in FIG. 1, as previously described. That signal on line 18 is based on a pre-analysis of the pattern density and the registration time requirements. The signal on line 18 is converted to an analog voltage by digital-to-analog converter (DAC) 42, which analog voltage is applied to summing amplifier 43. After the completion of a sub-field, the control system 29 receives a pulse on line 31 from pattern control section 15 in FIG. 1. That pulse is converted to an analog signal on line 45 by the frequency-to-voltage converter 46. The signal on line 45 is applied to difference amplifier 50. Laser LSB's on line 30 from the measurement system 21 are divided by digital divider circuits 48 providing its output on line 40 where the divisor "A" is proportional to the sub-field size and inversely proportional to the number of sub-fields per row. The output of the divider circuits 48 is applied to frequency-to-voltage converter 49. The output of converter 49 on line 41 is then applied to difference amplifier 50. Ideally, the output of the frequency-to-voltage converters 46 and 49 will be identical and therefore the output of the difference amplifier 50 will be "0". The output of the difference amplifier 50 is also applied to summing amplifier 43 as was the output of DAC 42. Deviations sensed by summing amplifier 43 will decrease or increase the velocity control signal on line 6 to Y stage drive mechanism 35 in FIG. 1. It can be recalled that the stage drive mechanism 35 controls motor 67 which drives the work table in the y direction in response to the signals on lines 6 and 34 in FIG. 1. Referring again to FIG. 4, the laser LSB signal on line 30 from FIG. 1 is also counted by digital circuits in counter 53 in FIG. 4. The output from counter 53 on lines 51 is converted to an analog signal on line 54 by digital-to-analog converter 55, whose output signal on line 54 to large field deflection control system 19 in FIG. 1 causes the deflection system 17 to follow the table motion.
Referring again to FIG. 4, after a complete row of sub-fields has been written, the counter 53 is reset by the output of the digital divider 56 carried on line 32. Since the divider 56 receives a pulse per sub-field on line 31 from the pattern control section 15 in FIG. 1, the beam B is placed in the proper position for writing the next row of sub-fields. The laser LSB signal on line 30 is also converted to an analog signal on line 58 by frequency-to-voltage converter 57, as a feed-forward signal to the large field deflection control system 19 in FIG. 1. This signal provides circuit delay compensation to the large field deflection system 17.
ALTERNATIVE DESIGNS
Industrial Applicability
This invention is applicable in manufacture and testing of VLSI chips. | This system employs writing of lithographic patterns with a shaped electron beam exposure system which minimizes the time wasted by workpiece positional requirements. The writing field contains an array of sub-fields written in a raster sequence. The large width of the writing field provided by the VAIL system reduces the number of mechanical scans required to write the pattern on the workpiece which further reduces the time required for workpiece positioning. When patterns are being superimposed over previously written patterns, registration is employed. This system includes a registration field confined to local areas on the workpiece, which is larger than the writing field, without requiring change in focus and without requiring the mechanical system comprising the X-Y work table to change speed during the registration and reregistration of the various fields on a semiconductor wafer or mask. The registration field can be larger than the writing field is possible because the quality requirements demanded from the shaped electron beam are less for detecting the locations of such registration marks at the various locations on the wafer. | 7 |
BACKGROUND OF THE INVENTION
[0001] Consumers have expressed an interest in decorating various articles of personal property with various symbols, letters, characters, numbers, and the like. These articles include portable electronic devices, such as cell phones, portable audio and audio/video devices, portable computers, among other products.
[0002] Existing approaches to such decoration usually involve the acquisition of decorative elements, such as crystals, and glue and then manually affixing the decorative elements to an article to be decorated. This approach may produce a decorative effect that approaches the desired result but includes many drawbacks. The manual approach is time consuming for a consumer at any skill level, but particularly so for a consumer who is not experienced at forming the desired decorative arrangement. Moreover, during what is likely to be a process of trial and error for most consumers, some number of decorative elements may be rendered unusable, thereby wasting these elements. Furthermore, some amount of glue may be misplaced both causing waste and unintentionally spilling glue onto surfaces that require a time-consuming cleanup after the work is complete.
[0003] In addition to the inefficiency of the existing approach, the quality of the result obtained using the existing approach will depend heavily on the experience and skill of the person applying the pattern of decorative elements. In some cases, the resulting patterns may have poor geometric consistency and be unsightly, thereby defeating the decorative purpose the entire process is intended to accomplish. Moreover, in other cases, a mistake may be difficult to correct since once the glue dries, removal of improperly located decorative elements may be difficult to achieve and/or may damage the decorative elements and/or the article of personal property being decorated. Accordingly, there is a need in the art for an improved apparatus and method for decorating articles of personal property.
SUMMARY OF THE INVENTION
[0004] According to one aspect, the invention provides a device, comprising: a sheet suitable for attachment to an article of personal property; and a plurality of decorative elements disposed on a first surface of the sheet, the decorative elements displaying a pattern on the device.
[0005] According to another aspect, the invention provides an apparatus comprising: a container; a plurality of decorative devices disposed within the container, each decorative device comprising a sheet having first and second surfaces, the second surface having an adhesive layer affixed thereto and being connected via the adhesive surface to a backing layer, the first surface having a plurality of decorative elements disposed thereon, the decorative elements displaying a pattern on the first surface, the decorative devices being suitable for affixation to one or more articles of personal property; and a mechanism for closing the container.
[0006] According to yet another aspect, the invention provides a method, comprising: providing a decorative device having a sheet, the sheet having a first surface and a second surface, the first surface having a plurality of decorative elements disposed thereon, the plurality of decorative elements displaying a pattern; providing an article of personal property; and securing the decorative device to a surface of the article.
[0007] Other aspects, features, advantages, etc. will become apparent to one skilled in the art when the description of the preferred embodiments of the invention herein is taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] For the purposes of illustrating the various aspects of the invention, there are shown in the drawings forms that are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
[0009] FIG. 1 is a plan view of a decorative device connected to a backing layer in accordance with one or more embodiments of the present invention;
[0010] FIG. 2 is a plan view of a plurality of decorative devices connected to a backing layer in accordance with one or more embodiments of the present invention;
[0011] FIG. 3 is a plan view of a decorative device connected to a backing layer in accordance with one or more embodiments of the present invention;
[0012] FIG. 4 is a plan view of a decorative device attached to a backing layer, there being a variation in cosmetic characteristics among the decorative elements disposed on the decorative device in accordance with one or more embodiments of the present invention;
[0013] FIG. 5 is a plan view of a decorative device attached to a backing layer showing a star pattern using a variation in cosmetic characteristics of decorative elements disposed on the decorative device in accordance with one or more embodiments of the present invention;
[0014] FIG. 5A is a cross-sectional view of the decorative device and backing layer taken along the line 5 A in FIG. 5 ;
[0015] FIG. 6 is a perspective view of a plurality of decorative devices attached to a cell phone in accordance with one or more embodiments of the present invention;
[0016] FIG. 7 is a perspective view of a plurality of decorative devices attached to a cell phone in accordance with one or more embodiments of the present invention;
[0017] FIG. 8 is a perspective view of a plurality of decorative devices attached to a portable electronic audio device in accordance with one or more embodiments of the present invention;
[0018] FIG. 9 is a perspective view of a kit of decorative devices incorporated within commercial packaging in accordance with one or more embodiments of the present invention;
[0019] FIGS. 10-12 are plan views of groups of decorative devices which could be included in kits, such as the kit of FIG. 9 , in accordance with one or more embodiments of the present invention;
[0020] FIG. 13 is a plan view of a decorative device incorporating a pattern of a leopard hide in accordance with one or more embodiments of the present invention;
[0021] FIG. 14 is a plan view of a decorative device incorporating a pattern of a zebra hide in accordance with one or more embodiments of the present invention; and
[0022] FIG. 15 is a plan view of a decorative device incorporating a pattern of a tiger hide in accordance with one or more embodiments of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Herein, the term “pattern” includes all images illustrated by decorative elements disposed on decorative devices in FIGS. 1-8 , thereby including but not limited to heart shapes, rectangles, single-element-wide rows of decorative elements, arc-shaped rows of decorative elements, and alphanumeric characters.
[0024] With reference to the drawings, wherein like numerals indicate like elements, there is shown in FIG. 1 a plan view of a decorative device 102 connected to a backing layer 104 in accordance with one or more embodiments of the present invention. Decorative device 102 may be affixed to backing layer 106 via the use of an adhesive layer (not shown). However, means of attachment other than adhesive material may be used for attachment of attachment device 102 to an article of personal property. These alternative means may include but are not limited to magnetic force, clips, force fit, suction, and static electricity.
[0025] The pattern displayed by the arrangement of decorative elements 106 may be implemented in various ways. The decorative elements may substantially fill the available space on sheet 108 of decorative device 102 . In this case, the shape of sheet 108 and thus of decorative device 102 will substantially determine the pattern displayed by the totality of decorative elements 106 . As is discussed in connection with other FIGS below, a pattern displayed by decorative elements 106 may also be implemented based on a pattern of placement of decorative elements 106 on sheet 108 and/or by color variation among the decorative elements located on sheet 108 of decorative device 102 .
[0026] In the embodiment of FIG. 1 , decorative elements 106 can substantially fill the space on the upper surface of sheet 108 of decorative device 102 . In this embodiment, decorative device 102 has a rectangular outer perimeter and a rectangular cutout in the center, which accounts for a portion of backing layer 104 being visible near the center of decorative device 102 .
[0027] A wide range of shapes could be selected for decorative device 102 . Moreover, shapes for decorative device 102 could be selected to match the shapes of surfaces of specific commercial products on which it is desired to locate decorative device 102 . Moreover, the decorative elements 106 may be of similar size and shape, or the sizes and shapes of decorative elements 106 may vary within one of the decorative devices disclosed herein.
[0028] FIG. 2 is a plan view of a plurality of decorative devices 202 - a , 202 - b and 202 - c connected to backing layer 204 in accordance with one or more embodiments of the present invention. In this embodiment, three separate decorative devices 202 a - c are initially located on a single backing layer 204 . Thus, as usual, the individual decorative devices 202 can remain intact as a user transfers one or more of them from backing layer 204 to the surface of a product or article. However, upon removing decorative devices 202 a - c from backing layer 204 , a user can re-arrange the relative placement of one or more of the decorative devices, as desired, on a surface of a personal article to obtain a desired pattern. It will be appreciated that any number of decorative devices 102 could be employed. Moreover, decorative devices 102 of different shapes could be located on a common backing layer 204 .
[0029] FIG. 3 is a plan view of a decorative device 302 connected to backing layer 304 in accordance with one or more embodiments of the present invention. In the embodiment of FIG. 3 , the displayed pattern of decorative elements 106 arises from the distribution of decorative elements on sheet 308 of decorative device 302 . Thus, in comparison with the embodiment of FIG. 2 , less work is needed to reproduce the series of three rectangular distributions of decorative elements 106 on an article using the embodiment of FIG. 3 . At the same time, the embodiment of FIG. 2 provides the user with greater flexibility in arranging the three separate decorative devices 202 a - c.
[0030] FIG. 4 is a plan view of a decorative device 402 attached to a backing layer 404 , there being a variation in cosmetic characteristics among the decorative elements 106 disposed on decorative device 402 in accordance with one or more embodiments of the present invention. In the embodiment of FIG. 4 , decorative device 402 can include sheet 408 on which decorative elements 106 may be placed. In this embodiment, a visible pattern may be implemented by varying one or more cosmetic characteristics of the various decorative elements 106 .
[0031] In FIG. 4 , for the sake of convenience, the illustration of cosmetic variation among the decorative elements 106 is shown by illustrating some decorative elements 106 with solid circles and other decorative elements 106 with hollow circles. However, cosmetic variation among decorative elements 106 in actual physical embodiments of decorative device 402 can be implemented by various means, such as by varying the color of decorative elements located on sheet 408 of decorative device 402 . Other characteristics of decorative elements 106 which may be varied to implement a visible pattern include, but are not limited to, the shape and/or size of the decorative elements 106 , the spacing between neighboring elements, the reflectivity of the elements, and/or the degree of transparency of each element 106 .
[0032] FIG. 5 is a plan view of decorative device 502 attached to backing layer 504 showing a star pattern 510 using a variation in cosmetic characteristics of decorative elements 106 disposed on decorative device 502 in accordance with one or more embodiments of the present invention. FIG. 5 illustrates a concept similar to that shown in FIG. 4 except that FIG. 5 illustrates a star-shaped pattern. It will apparent to those of skill in the art that patterns of any shape and that any total number of patterns may be illustrated within one decorative device 502 using the principles disclosed herein.
[0033] FIG. 5A is a sectional view of the decorative device and backing layer of FIG. 5 . In this embodiment, backing layer 504 is shown at the bottom. Adhesive layer 512 of decorative device 502 is shown above backing layer 504 . Sheet 508 of decorative device 502 is shown above adhesive layer 512 . Finally, a layer 514 of decorative elements 106 is shown on sheet 508 . While the embodiment of FIG. 5A shows an adhesive layer, it will be appreciated that the present invention is not limited to the use of an adhesive layer. As previously discussed, other means including magnetism, clips, suction, clamps, force fit, static electricity, or other mechanisms may be employed to locate decorative device 502 on an article of property of a user's choice.
[0034] In one embodiment, decorative elements 106 may be pieces of plastic and/or glass having a plurality of substantially flat surfaces for reflecting light in a decorative and desirable manner. In one embodiment, decorative elements 106 can have a diameter of about 0.1 inches, although decorative elements larger or smaller than this may be used. In one embodiment, decorative elements 106 can be generally spherical and have generally flat surfaces disposed about a periphery of the generally spherical shape, thereby emulating the appearance of a precious gem. Moreover, decorative elements 106 could be three-dimensional polygons of any size and having a wide range of possible shapes. Moreover, decorative elements 106 are not limited to any particular shape, to any particular size, or to being made of any particular material.
[0035] Decorative elements 106 may be made of inexpensive materials, such as plastic or glass. Alternatively, decorative elements 106 may include items of greater value, such as gems, if desired. Decorative elements 106 could also include pieces of metal or other material which could be located on the surface of sheet 508 of decorative device 502 or within sheet 508 . Moreover, decorative elements may be made of any material or combination of materials selected from a group that includes but is not limited to: crystal, glass, plastic, metal, wood, paper, leather, metal oxides, and ceramic.
[0036] In some embodiments, decorative elements 106 can be located on a surface of sheet 508 of decorative device 502 (or other embodiments of decorative devices 102 , 202 , 302 , 402 , etc). Alternatively, decorative elements 106 could be embedded within a layer of material forming part of sheet 508 of decorative device 502 . In still other embodiments, decorative elements 106 could be located on a lower surface of sheet 508 .
[0037] Items which decorative devices ( 102 , 202 , 302 , 402 , and/or 502 ) may be placed on include but are not limited to: cell phones, portable digital audio devices, computers including portable computers, cameras, cosmetic supply containers, sunglasses, toothbrushes, remote control devices, address books, ceramics, combs, mirrors, watches, pill boxes, flower pots, picture frames, hairbrushes, hair accessories, handbags, calculators, shoes, hats, shirts, pants, and other articles of clothing, wine glasses, chests and other containers of personal goods, joysticks, telephones, microphones, clocks, household thermometers and humidifiers, pens and pencils and other writing instruments, hair clips, watches, remote control devices for home audio and video devices, toys, dolls, figurines, tape dispensers, staplers and other home office products, scissors, candle holders, lamps such as lava-lamps, other household products, and other electronic products, whether portable or not.
[0038] FIG. 6 is a perspective view 600 of a plurality of decorative devices attached to a cell phone in accordance with one or more embodiments of the present invention. It is noted that in the embodiment of FIG. 6 , the shape and size of decorative device 602 substantially matches the size and shape of the surface to which it is attached. Decorative device 602 could be manufactured to match the surface to which it is attached in FIG. 6 . Alternatively, device 602 could be customized by a user to fit the surface of the cell phone of FIG. 6 or the surfaces of other articles. In the embodiment of FIG. 6 , the pattern displayed in decorative device 602 is a heart. However, any pattern could be displayed by decorative device 602 .
[0039] In the embodiment of FIG. 6 , additional decorative devices 604 , 606 , and 608 are also shown. In this embodiment, decorative device 604 forms an arc composed of substantially spherical decorative elements substantially matching the shape of a display screen on the cell phone to which it is attached, the arc being coupled to a row of decorative elements at one end of the arc. Alternatively, the arc and row of decorative elements forming decorative device 604 could be provided by two or more separate decorative devices.
[0040] In the embodiment of FIG. 6 , decorative device 606 includes a row of substantially spherical decorative elements, located alongside and substantially parallel to the straight-row portion of decorative device 604 . In FIG. 6 , decorative device 608 includes two substantially straight and substantially parallel rows of decorative elements located next to decorative device 602 . In an alternative embodiment, two separate decorative devices could be employed to provide the two rows of decorative device 608 . It will be appreciated that additional decorative devices could be added to the cell phone of FIG. 6 , if desired.
[0041] FIG. 7 is a perspective view 700 of a plurality of decorative devices 702 , 704 , 706 , and 708 attached to a cell phone in accordance with one or more embodiments of the present invention. In this embodiment, decorative device 702 displays a script version of the letter “B.” Moreover, in this embodiment, the pattern of this letter is formed via the distribution of the decorative elements on device 702 rather than via color variation, or other cosmetic variation, among the decorative elements. It will be appreciated that any alphanumeric character or image or combination thereof could be represented employing the patterning method used in decorative device 702 .
[0042] The embodiment of FIG. 7 also includes decorative devices 704 , 706 , and 708 . In this embodiment, decorative devices 704 and 706 are substantially straight and substantially parallel rows of substantially circular decorative elements. In an alternative embodiment, the rows of decorative elements provided by decorative devices 704 and 706 could be provided by a single two-row decorative device.
[0043] The embodiment of FIG. 7 further includes decorative device 708 which includes one arc pattern of decorative elements and two substantially parallel rows of decorative elements. In an alternative embodiment, the arc and two rows of decorative elements included in decorative device 708 could be provided employing two or more separate decorative devices.
[0044] FIG. 8 is a perspective view 800 of a decoration 802 attached to the front surface of a portable electronic audio device in accordance with one or more embodiments of the present invention. Since decoration 802 includes a number of different geometric patterns (a circle and a plurality of rectangles), decoration 802 could be provided either with one decorative device incorporating all of the geometric patterns shown in FIG. 8 or with a plurality of decorative devices, each including one or more of the geometric patterns shown in FIG. 8 .
[0045] In one or more embodiments of the present invention, the decorative devices disclosed herein can be removed from surfaces of articles of personal property to which they have been attached without causing damage either to the article or to the decorative device. In the case of articles of clothing, the decorative devices can be removed prior to washing clothes and then replaced on the clothing once washing and drying are complete. Thus, damage to the disclosed decorative devices from the effects of washing machines and dryers can be readily avoided. This contrasts with the situation faced when using existing forms of clothing decoration.
[0046] In the case of cell phones and other electronic products, the decorative devices disclosed herein can be removed without damaging the cell phone or other electronic product. This feature can help avoid problems, for instance, when returning the cell phone or other device to a retailer or manufacturer for refund, maintenance or repair.
[0047] FIG. 9 is a perspective view of a kit 900 of decorative devices incorporated within commercial packaging in accordance with one or more embodiments of the present invention. Kit 900 can provide a user with a convenient assortment of decorative devices (such as, but not limited to, devices 102 , 202 , 302 , 402 , 502 , 602 , and 602 ) which devices can have different sizes and shapes and which can incorporate different patterns and/or characters thereon. The decorative devices included in kit 900 may be used as originally provided, or may be modified (by cutting to various shapes and sizes) as desired by a user. The decorative devices (not shown) can be used either individually, or in combination, to provide a desired result.
[0048] Different kits 900 may be made available with different ones of the kits having different combinations of decorative devices therein. Moreover, different kits may have different themes within which the included decorative devices fall. For instance, one exemplary kit could focus on alphabetic characters. This type of kit could enable a purchaser to construct a desired sequence of characters, customized to that purchaser's wishes. The sequence of characters could, for instance, correspond to a first name, a nickname, or a set of initials. In this embodiment, while the patterns representing the individual characters would be pre-arranged, the sequence of characters placed onto an article by a purchaser could be selected by the purchaser.
[0049] In another embodiment, kits of decorative devices could be tailored to decorate particular commercial products. For instance, kits could be customized to accommodate a selected Samsung® cell phone, Motorola® cell phone, I-pod®, Palm Pilot® and/or numerous other consumer products whether electronic or non-electronic, and whether portable or non-portable. While tailored for a particular product, these kits could include a wide variety of different decorative devices, with some devices illustrating images, others illustrating alphanumeric symbols and so forth.
[0050] More generally, the pre-arranged patterns could be standard or custom-made. Thus, some decorative devices could include patterns which are widely used and which are not specific to a particular purchaser or group of purchasers. However, other decorative devices could include patterns that are customized for specialized groups of customers or even for individual customers. For instance, letter sequences spelling out names such as “Jack” or “Susan” could be made available on selected decorative devices for purchasers wishing to acquire decorative devices with such names illustrated thereon as pre-arranged patterns.
[0051] FIG. 10 illustrates a group of decorative devices which could be included in a kit, such as the kit of FIG. 9 , in accordance with one or more embodiments of the present invention. In the embodiment of FIG. 10 , a kit could include forty decorative devices 1002 illustrating a star-shaped pattern, eighty devices 1004 each device having two sets of closely spaced rows of decorative elements, four devices 1006 having decorative elements sparsely distributed within a “square” pattern and thirty-six devices 1008 having decorative elements closely spaced and forming the perimeter of a square. Clearly, the number and type of the devices that could be included in a kit could be varied extensively, and all such variations are intended to be included within the scope of the present invention. In one or more embodiments, the decorative devices of FIG. 10 , which can be included within one kit of devices, are selected for their suitability for application to a particular article of personal property, such as a particular cell phone or particular hair care product.
[0052] FIG. 11 illustrates a group of devices similar to those illustrated in FIG. 10 except that a group of thirty-two devices 1102 having heart-shaped patterns has been substituted for the group of forty devices 1002 having star-shaped patterns shown in FIG. 10 . As with the embodiment of FIG. 10 , the number and type of devices that could be included in a kit could be varied extensively, and all such variations are intended to be included within the scope of the present invention. In one or more embodiments, the decorative devices of FIG. 11 , as with the devices of FIG. 10 , can be selected for their suitability for application to a particular article of personal property and can all be included within one kit of devices.
[0053] FIG. 12 illustrates a group of devices similar to those illustrated in FIG. 10 except that a group of forty-one devices 1202 having butterfly-shaped patterns has been substituted for the group of forty devices 1002 having star-shaped patterns shown in FIG. 10 . As with the embodiment of FIG. 10 , the number and type of devices that could be included in a kit could be varied extensively, and all such variations are intended to be included within the scope of the present invention. In one or more embodiments, the decorative devices of FIG. 12 , as with the devices of FIGS. 10 and 11 , can be selected for their suitability for application to a particular article of personal property and can all be included within one kit of devices.
[0054] In one or more embodiments, the decorative devices shown in FIGS. 1-8 and 10 - 12 are intended to be applied as inseparable units of decoration, without isolating the individual decorative elements 106 for independent attachment to articles of personal property. For example, decorative devices 1002 , 1102 , and 1202 including images of a star, a heart and a butterfly ( FIGS. 10, 11 and 12 ), respectively, are intended to be applied as single units of decoration and not separated out into dozens of separately applied decorative elements 106 . Moreover, in one or more embodiments, decorative devices 1004 , which include rows of decorative elements 106 , are also intended to be applied to articles as single units of decoration.
[0055] FIGS. 10-12 are plan views of groups of decorative devices which could be included in kits, such as the kit of FIG. 9 , in accordance with one or more embodiments of the present invention;
[0056] FIG. 13 is a plan view of a decorative device 1302 incorporating a pattern of a leopard hide in accordance with one or more embodiments of the present invention. In one embodiment, the colors of decorative elements 106 within device 1302 may be varied to implement the illustrated pattern.
[0057] FIG. 14 is a plan view of a decorative device 1402 incorporating a pattern of a zebra hide in accordance with one or more embodiments of the present invention. In one embodiment, the colors of decorative elements 106 within device 1402 may be varied to implement the illustrated pattern.
[0058] FIG. 15 is a plan view of a decorative device 1502 incorporating a pattern of a tiger hide in accordance with one or more embodiments of the present invention. In one embodiment, the colors of decorative elements 106 within device 1502 may be varied to implement the illustrated pattern.
[0059] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims, and such alternatives are meant to be incorporated herein. | A device is disclosed which includes a sheet suitable for attachment to an article of personal property; and a plurality of decorative elements disposed on a first surface of the sheet, said decorative elements displaying a pattern on said device. A method is disclosed which includes providing a decorative device having a sheet, the sheet having a first surface and a second surface, the first surface having a plurality of decorative elements disposed thereon, the plurality of decorative elements displaying a pattern; providing an article of personal property; and securing the decorative device to a surface of the article. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 11/036,513, filed Jan. 14, 2005 now U.S. Pat. No. 7,192,392 which is a continuation of PCT/EP03/07216, filed Jul. 5, 2003, claiming priority from German Application No. 102 32 147.7, filed Jul. 16, 2002 which is hereby incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a nonwoven perforation device for manufacturing a perforated nonwoven and a perforated nonwoven material
Perforating materials is part of the prior art if the intention is to provide specific properties in materials, such as permeability to liquid and/or vapor. For example, providing a top sheet of a material for a hygiene article with perforations is known from U.S. Pat. No. 3,965,906. For this purpose, a needle roller is used, which is positioned diametrically opposite a brush roller. Using this perforation device, a film or a nonwoven is perforated. The nonwoven or film is to absorb liquid and conduct it through when it is used as a top sheet in a hygiene article. A perforation device which has a needle roller and a perforated roller is known from European Patent Application 1 046 479 A1 and from European Patent Application 1 048 419. Nonwoven materials and films may be passed through between the needle roller and the perforated roller and perforated. Using this device, three-dimensional perforation holes are also to be achieved in particular.
The object of the present invention is to allow continuous perforation of approximately circular holes.
SUMMARY OF THE INVENTION
The present invention provides a perforation device which can be used for manufacturing a perforated nonwoven material, more particularly, a thermobonded nonwoven having embossed points. Needles of the needle roller of the nonwoven perforation device engage in the nonwoven and perforate the nonwoven. The nonwoven is subsequently processed further. This may occur either directly after the nonwoven perforation device or at a later time. For example, the nonwoven is wound up using a rewinder after the perforation. The surface of the nonwoven may also be treated. For example, one or more substances may be applied. The present invention provides that the ratio between a needle number of the needle roller and an embossed point number of the thermobonded nonwoven provided with embossed points is set between 0.15 and 0.25 and a ratio of a hole size in the perforated nonwoven to an embossed point size of the thermobonded nonwoven is set 15 between 0.15 and 0.25. A further improvement may be achieved if the ratio between perforation count and embossed point number is between 0.15 and 0.19. An additional improvement may also be observed if the ratio between hole size and embossed point size is between 0.15 and 0.19.
It has been shown that it is advantageous for achieving holes which are circular as possible in the perforated nonwoven if the corresponding perforation tool and the embossed points in the nonwoven are tailored to one another. Otherwise, the perforated holes may have notches or may be implemented as oval. In particular, it has been shown to be advantageous, for a predetermined embossed surface, to use a corresponding number of many small embossed figures, instead of manufacturing this embossed surface through a few large embossed figures and, in particular, embossing points. Experiments have shown that during a perforation step, smaller embossed figures may be displaced much more easily than large figures. In the following, the concept of embossed point is to be understood as all embossed figures which fall under the definition above. According to one embodiment, the embossed figures cover the entire surface without any intermediate space. According to another embodiment, the embossed figures are at least partially provided with an intermediate space, in the form of a ring, for example. Further embossed figures may be round, rhomboidal, oval, rectangular, and/or approximately star-shaped. Different embossed figures may also be used together.
Parameters of experimental rollers, using which different tests were performed, may be read from the following table. The rollers used were engraved rollers. The embossed figures may, however, also be applied to a matrix through spark erosion or other production methods, for example. The matrix does not absolutely have to be a roller. Instead of a roller, a strip or something similar may also be used.
Figure
Pressing
shape
area
Pressing
in top
Dimension
area
Figures
Pressing area
Roller
view
[mm]
[mm 2 ]
[number/cm 2 ]
proportion [%]
Roller 1
Circular
0.541
0.208
69.86
14.49
Roller 2
Circular
0.756
0.449
32.65
14.66
Roller 3
Oval
0.834*
0.325
49.90
16.19
0.495
It has been shown to be advantageous if a pressing area of an embossed figure is in a range between 0.15 mm 2 and 0.4 mm 2 , preferably in a range between 0.18 mm 2 and 0.35 mm 2 . The number of embossed figures is to be between 43 per cm 2 and 80 per cm 2 . A pressing area proportion on a roller is preferably between 10% and 18%, for example.
It is advantageous if a nonwoven is used which has an embossed point count between 55 points/cm 2 and 80 points/cm 2 . An appropriately thermally treated nonwoven may be provided from an unwinder. Another embodiment provides that the nonwoven is guided directly from a nonwoven production device to a thermobonding device. Subsequently, the thermally bonded nonwoven having the desired embossed point count and embossed point size is guided to the nonwoven perforation device. Between 10 perforation/cm 2 and 20 perforation/cm 2 are preferably produced in the nonwoven. Particularly in the field of hygiene applications, this number of perforations has been shown to be advantageous for absorbing the liquids which encounter the nonwoven. For hygiene applications, the perforated nonwoven is used as a top sheet, for example. Further fields of application are the household field, for example, top sheets in dishcloths, the medical sector, for cover sheets, for example, for protective clothing, and other fields. Furthermore, the nonwoven may be used in filtration applications, in construction, and/or in laminates with other materials. These may be fabrics, films made of metal or thermoplastic material, and even rigid surfaces, paper, paperboard, or even nets.
Dimensions of a needle roller, using which exemplary experiments were performed, are listed in the following table.
Needle
Needle
Needle
area
Needle shape
diameter
area
Needles
proportion
Roller
in top view
[mm]
[mm 2 ]
[number/cm 2 ]
[%]
Needle
Circular
1.95
2.987
15.36
45.86
roller
An insertion depth of the needles was preferably between 2 mm and 4.5 mm, particularly between 2.5 mm and 3 mm, for example. The insertion depth of the needles is particularly a function of the nonwoven thickness. Preferably, particularly for the hygiene field, nonwoven weights between 14 gsm and 50 gsm are used. In other fields, nonwoven weights of more than 50 gsm may be used, particularly in construction, for textiles, and for geotextiles.
A preferred hole size in the nonwoven is between 0.8 mm 2 and 1.8 mm 2 . Furthermore, a perforated nonwoven which has embossed points caused by thermobonding has a ratio of a perforation count to an embossed point count between 0.15 and 0.25 and a ratio of a hole size to an embossed point size between 0.15 and 0.25. A further improvement may be achieved if the ratio between perforation count and embossed point count is between 0.15 and 0.19. An additional improvement may also be observed if the ratio between hole size and embossed point size is between 0.15 and 0.19.
The following table reproduces exemplary data of a perforated nonwoven. This is data which was obtained from a single-layer 15 spunbonded nonwoven having an area weight of 30 gsm.
Hole dimensions
Area [mm 2 ]
1.16
Diameter MD [mm]
1.33
Diameter CD [mm]
1.11
Axis ratio MD/CD
1.2
Open area
[%]
18.7
Thickness
[mm]
0.709
Tensile strength
MD [n/50 mm]
26.63
CD [N/50 mm]
23.52
Extension
At rupture MD [%]
21.93
At rupture CD [%]
30.14
MD: machine direction
CD: cross direction
Different strength properties may be influenced through different variables. These variables may be the number of perforations, the number of bonding embossings in the nonwoven, their size, and also other parameters.
The corresponding parameters are preferably to be set in such a way that the nonwoven has a strength in MD which is greater than a strength in CD. In particular, the nonwoven has a minimum strength of 6 N/50 mm in CD and 8 N/50 mm in MD. Preferably, particularly in hygiene applications if the nonwoven is used as a top sheet, for example, the nonwoven has a strength which is at least 20 N/50 mm in both directions.
The nonwoven used may be single layer or multilayer. It may have one or more polymers. Usable polymers are particularly polypropylene, polyethylene, polyamide, polyester, etc. The nonwoven may be a spunbonded nonwoven, a meltblown, a staple fiber nonwoven, or something different. The fibers of the nonwoven may be multicomponent fibers.
According to a further idea of the present invention, a perforated nonwoven is provided which has embossed points produced by thermobonding. The perforations have crater-like perforation edges in the nonwoven, which arise from the nonwoven. A longest axis of an embossed point in the nonwoven is smaller than a height of a perforation edge of a perforation in the nonwoven. In particular, the perforation edge to be considered is positioned neighboring the embossed point whose longest axis is considered in the ratio to the height of the perforation edge. It has been shown that with this type of selection of a ratio between three-dimensionality and the perforation and thermal bonding of the nonwoven, an especially large uniformity of round perforations may be observed, which may be produced continuously.
A further idea of the present invention provides that a nonwoven perforation device is provided for performing a method described above and/or for manufacturing a nonwoven described above. The nonwoven perforation device has at least one needle roller and a counter roller. The needle roller and the counter roller form a gap. A nonwoven is guided through the gap for perforation. The needle roller has a needle count between 10 needles/cm 2 and 25 needles/cm 2 . At least some of the needles have a circular diameter. An effective needle diameter is between 1.5 mm and 2.5 mm. A needle area component of the surface of the needle roller is between 35% and 65%. The effective needle diameter is the diameter which generates the perforations in connection with the nonwoven and is responsible for their size.
Advantageous features and embodiments arise from the following drawing. The features illustrated therein do not restrict the present invention as such, however, but rather may be combine with the features already described into further refinements of the present invention, not described here in greater detail.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
FIG. 1 shows a first perforated nonwoven,
FIG. 2 shows a close-up of a perforation, and
FIG. 3 shows a nonwoven perforation device in a schematic view.
DETAILED DESCRIPTION OF THE INVENTION
The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the inventions are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
FIG. 1 shows an example of a perforated nonwoven 1 . The nonwoven is single-layer and has an area weight of 30 gsm. The nonwoven is a spunbonded nonwoven, which has been produced according to the Dokan method. A standard polypropylene was used as the thermoplastic material. The nonwoven is illustrated here in a top view, black cardboard being used as an underlay. Furthermore, this view is in a scale which shows dimensions in mm. The zoom factor used here is 1.5. Beside the perforations 2 , which may be seen as black holes, there are embossed points 3 . The embossed points 3 are much smaller than the perforations 2 . The perforations 2 are preferably larger than the embossed points 3 by at least a factor of 4.
FIG. 2 shows an enlargement of FIG. 1 . The perforated nonwoven 1 is illustrated with a perforation 2 and the surrounding embossed points 3 . It may be seen that fibers of the nonwoven 1 are displaced by the perforation procedure and form a perforation edge 4 . The fiber structures are preferably maintained in this case. The fibers have not been melted. A further embodiment provides that the fibers are heated to the softening temperature, so that neighboring fibers adhere to one another on their surface. Embossed points 3 are also partially included in this perforation edge 4 . Although these embossed points cause a certain rigidity and strength in the nonwoven, the embossed point size is tailored in such a way that perforation still leads to approximately circular holes. If the embossed point size is too large in relation to the size of the perforation 2 , there is the danger that the holes will have notches. Instead of circular perforations 2 , oval holes or holes having another shape could also arise. It has been shown to be especially advantageous if a longest axis of an embossed point is smaller than a height of a perforation edge 4 , which arises through deformation of the nonwoven during the perforation. The relatively strong embossed point is otherwise deformed through the deformation of the nonwoven in such a way that indentations arise at the edge of the perforation hole.
FIG. 3 shows a nonwoven perforation device 5 having a needle roller 6 and a counter roller 7 . Needles 8 are positioned on the needle roller 6 . The needles 8 engage in the surface 9 of the counter roller 7 . The surface 9 is preferably yielding to the needles 8 . In particular, the surface 9 may have a felt material. Furthermore, the nonwoven perforation device 5 has an unwinder 10 . A prebonded nonwoven 14 , which is provided with embossed points, is guided from the unwinder 10 to the counter roller 7 via rolls 12 . The rolls 12 preferably include a tension measuring roll 13 . The tension measuring roll allows a tensile force, which acts on the nonwoven 14 to be perforated, to be checked. The tensile force may, for example, be set via the rolls 12 and via the tension measuring roll 13 , particularly also in interaction with the counter roller 7 and the unwinder 10 . From the tension measuring roll 13 , the nonwoven 14 to be perforated is guided to the counter roller 7 and loops around it for a specific range. This range is preferably greater than 45 degrees. In this range, while in contact with the counter roller 7 , the nonwoven may be heated, for example. In particular, there is the possibility of heating the nonwoven to a temperature which lies below the melting temperature of the polymer used or the polymers from which the nonwoven was produced. Furthermore, the nonwoven may also be heated up to a limit of the softening temperature of the thermoplastic material. From the counter roller 7 , the nonwoven 14 to be perforated is guided into a gap 15 . The gap 15 is formed by the needle roller 6 and the counter roller 7 . In the gap 15 , the nonwoven 14 to be perforated is perforated by the needles 8 . In this case, the needles 8 are engaged with the surface 9 of the counter roller 7 . According to this embodiment of the nonwoven perforation device 5 , this perforated nonwoven is preferably guided from the counter roller 7 to the needle roller 6 . The nonwoven preferably remains on the needle roller 6 for a certain looping range. The looping range is preferably greater than 45 degrees, in particular, it is in a range between 90 degrees and 270 degrees. Keeping the perforated nonwoven 1 on the needle roller 6 particularly leads to stabilization of perforation edges. Instead of looping of the needle roller 6 , the perforated nonwoven may also be guided to a winder 16 after the gap 15 . Rolls 12 are preferably again positioned between the needle roller 6 and the winder 16 . One of the rolls 12 is preferably a tension measuring roll 13 . The perforated nonwoven 1 coming from the needle roller 6 may again be wound into a roll on the winder 16 at an adjustable defined tension in this way.
Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. | The present invention relates to perforation device for the manufacture of a perforated nonwoven material, whereby a prebonded nonwoven with embossing points is guided to a nonwoven perforation device, needles of a needle roller engage into the prebonded nonwoven and perforate it, and the perforated nonwoven material then undergoes further processing. A ratio is set between the number of needles to the number of embossed points of between 0.15 and 0.25 and a ratio of hole size to embossed point size of between 0.15 and 0.25. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for detecting a level of liquid in a liquid storage tank, and provides a float type liquid level meter comprising a connecting lever which has a structure to suppress a fluctuation of a liquid level signal.
In a conventional float type liquid level meter, a connecting lever connecting a float and an apparatus for detecting buoyancy is comprised of a solid rod of small diameter, having a lighter weight than the float and of sufficient strength to hold the float, aiming only to transmit changes in weight of the float and which changes depend on a liquid level to the apparatus for detecting buoyancy. Therefore, such methods to provide a countermeasure with elements other than a connecting lever itself as a method to insert the connecting lever into a guide tube without any contact and a method to furnish supporting arms, extended from a float toward an inside wall of a liquid storage tank etc., are used as a method to suppress and moderate effects of disturbance which are caused with a bending stress to the connecting lever by buoyancy, or with a lateral oscillation by liquid flow. Several float type liquid level meters according to prior art are exemplified in the publication, such as, Japanese Patent Application Laid-Open No. 57-10417.
An example of the prior art using a tubular rod as a connecting lever to transmit a change of liquid level is disclosed in the U.S. Pat. No. 4,646,796, but a float to detect a liquid level and the connecting rod move concurrently with a magnetic connection and the float and the connecting rod are not connected directly. Therefore, the U.S. Pat. No. 4,646,796 is different in composition of a liquid level meter from the present invention, in which a float type liquid level meter comprising a float, an apparatus to detect buoyancy of the float and to convert the buoyancy to a liquid level, and a connecting rod which connects the float and the apparatus to detect buoyancy is disclosed.
The prior art described above considers a disturbance caused by buoyancy and liquid flow but not that from an external vibration effected directly to the liquid level meter itself. Consequently, when a vibration is caused at a place where the liquid level meter is installed, the vibration is transmitted to the liquid level meter itself and a phenomenon causing the fluctuation of an output signal from the liquid level meter is generated in spite of the liquid level itself being kept stable.
As a countermeasure for the phenomenon, in the case of a liquid level regulating system in which a regulating valve is operated with a regulator which intakes an output signal from a liquid level meter, a method for using the regulator having a large time lag element is adopted in order to prevent a fluctuation of the output signal of the liquid level meter from effecting directly the liquid level regulating system. But, if the fluctuation of the output signal of the liquid level meter is suppressed, it is possible to use a regulator having a small time lag element and to respond quickly to a change of liquid level, and consequently, a performance of the liquid level regulating system is improved.
SUMMARY OF THE INVENTION
In view of an aspect described above, one of object of the present invention is to provide a float type liquid level meter wherein a fluctuation of an output signal is suppressed and a float type liquid level transmitter wherein a fluctuation of an output signal is suppressed.
Substantial structure of a connecting lever which is preferable to suppress a fluctuation of an output signal of a liquid level is any of a lever structure comprised with a hollowed body having a circular outer shape or a polygonal outer shape in a section which is transverse to a longitudinal axis of the connecting lever, a lever structure comprised with a solid rod having at least one enforcing blade on a circumferential surface of the rod along a longitudinal axis of the rod, and a lever structure comprised with a solid rod wherein at least one ring is inserted and fixed on the circumferential surface of the rod at least on one intermediate position of a longitudinal axis of the rod.
Similar results are obtained by applying a connecting lever having a structure to suppress a fluctuation of an output signal, as described above, to a float type liquid level transmitter comprising a float, a connecting lever, an apparatus for detecting buoyancy, and a transducer.
FIG. 1a is a partially cutaway view of a float type liquid level meter relating to the present invention. An operation theory of a float type liquid level meter will now be described with reference to FIG. 1a.
A float type liquid level meter is comprised with casings 2, 3, a float 4, a connecting lever 5, and an apparatus for detecting buoyancy 6 which measures an apparent weight of the float, converts the apparent weight to a liquid level and outputs a signal of the liquid level. A lower casing 3 is connected to a structure which is a target to detect a liquid level with connecting pipes 7, and according to a theory of a connecting pipe, a liquid level in the structure which is a target to detect a liquid level is revealed inside of the lower casing 3.
The float 4 is a hollow vessel and is connected to the apparatus for detecting buoyancy 6 with the connecting lever 5. In a case that liquid level is zero, the apparatus for detecting buoyancy measures weight of the float itself and converts the weight of the float itself to a liquid level, and a signal ε 0 is output as an indication of the liquid level is zero. In a case in which the liquid level is higher than a bottom line of the float by L, a buoyancy expressed by an equation (γLS), where γ is a specific gravity of a liquid and S is an area of a cross section of the float, of the float 4, results and an apparent weight of the float 4 expressed by an equation (W-γLS) is transmitted to the apparatus for detecting buoyancy wherein a signal ε 0 -Δε, where Δε is a displacement equivalent to the buoyancy, is output and a liquid level L is indicated.
With a float type liquid level meter which is operated on a theoretical base described above, an operation of a connecting lever having a structure to suppress fluctuation of an output signal related to the present invention is described in the following.
A connecting lever of a conventional float type liquid level meter has a simple structure, a solid rod with a small diameter, in aiming of only transmission of an apparent weight of a float which changes depending on a liquid level to the apparatus for detecting buoyancy. The conventional float type liquid level meter of such a structure has a phenomenon under an operation in which a liquid level output signal fluctuates in spite of the liquid level being kept at a stable condition. An investigation of a cause of such a fluctuation reveals that the fluctuation is induced with vibrations which are transmitted from outside of the apparatus for detecting buoyancy to casings and the connecting lever, wherein the vibrations are amplified by self-excitation, and a combination of a buoyancy and the amplified vibration is transmitted to the apparatus for detecting buoyancy and induces the fluctuation.
An external vibration transmitted to a connecting lever through a casing induces vibrations like a string as shown in FIG. 2 to the connecting lever. Vibrations of a string changes at random such as first mode, second mode, third mode, and so on, and amplitude of vibrations of a string are also changed. Therefore, even though frequency of generating fluctuation and strength of fluctuation change at random, a fluctuation having the maximum output power is generated with the first mode vibration of the connecting lever. If energies of external vibrations which are transmitted to the casing have a same value, a relation between the amplitude of vibration of the connecting lever V and natural frequency of vibration f is expressed with an equation V∝1/f as shown by a theory of vibration of a string. And, a relation between the amplitude of vibration of the connecting lever V and strength of fluctuation a is determined to be proportional, to each other by experiments, and the relation is expressed with equations, a∝V∝ 1/f, that is a ∝1/f. Accordingly, as the strength of fluctuation a is proportional to a reciprocal number, 1/f, of the natural frequency of vibration of the connecting lever f, the strength of fluctuation a becomes less by making a structure of the connecting lever to be a structure having a large natural frequency of vibration f, that means the fluctuation of output from a float type liquid level meter is suppressed.
Natural frequency of vibration f of a connecting lever is expressed by a following equation (Japanese Society of Mechanical Engineers: JSME Mechanical Engineers' Handbook Revised 5th Edition, page 3-49, 1968) as the equation for a transverse vibration of a rod having a relatively small constant sectional area along a longitudinal axis. ##EQU1## where, f: Natural frequency of a connecting lever
λ: Coefficient of frequency of vibration (First mode π/π, second mode 3π/2 . . . )
l: Length
E: Young's modulus
γ: Weight of a unit volume
A: Cross section
I: Secondary moment of the cross section
Based on the equation described above, four methods described hereinafter are understood to be effective to make natural frequency of a connecting lever larger and to suppress fluctuation of an output signal of a float type liquid level meter.
a) To shorten a length of a connecting lever
b) To enlarge a shape factor, I/A, of a connecting lever
c) To avoid vibrations of low order mode
d) To use substance having a large substance factor, E/γ, as materials for a connecting lever
Structures of a connecting lever described hereinafter are effective to embody the method described a) A connecting lever having a structure which
a) A connecting lever having a structure which enables the length of the connecting lever, l, to be as short as possible in consideration of a shape of a target structure to detect liquid level, a position where an apparatus for detecting liquid level is installed, liquid level of a target liquid, and an environmental condition such as corrosive atmosphere etc.
b) Further, a structure of a connecting lever which is comprised with a hollowed body having a large diameter and thin wall thickness in order to make the shape factor, I/A, of the connecting rod large. Shapes of a transverse cross section to a longitudinal axis of the hollowed body are preferably a ring and a hollowed polygon, etc.. Examples of the structure relating to the present invention are illustrated in FIG. 3b, 3d, 3e, 3f, and 3g with a prior art in FIG. 3a and 3c. FIG. 3a is an illustration showing a connecting lever 5 and a float 4 of prior art, and the shape of the cross section of the connecting lever 5 at A--A position in FIG. 3a is a circle with small diameter as shown in FIG. 3c. FIG. 3b is an illustration showing a float 4 and a connecting lever 5 which has a structure relating to the present invention, and the shape of the cross section of the connecting lever 5 at A'-A' position in FIG. 3b is a ring (or ring-like) as shown in FIG. 3d or a hollowed square as shown in FIG. 3e.
c) As another measure to increase rigidness of the connecting lever and to enlarge a value of the shape factor, I/A, a structure of a connecting lever having fin shape enforcing blades along the longitudinal axis on the circumferential surface of the connecting lever, and a structure of a connecting lever of which transverse cross section to the longitudinal axis of the connecting lever is cruciform shape. Examples of the structures described above are shown in FIG. 3f and FIG. 3g, respectively.
d) A structure of a connecting lever having rings which are fixed on the circumferential surface of the connecting lever at intermediate positions of the longitudinal axis of the connecting lever is effective to avoid low order vibration of the connecting lever. Especially, with making the number of rings one or two, a place where the ring is fixed comprises a node to suppress first mode vibration, and consequently, a fluctuation having the maximum output induced by first mode vibration is prevented. One of the examples of the structure described above is shown in FIG. 4a and FIG. 4b. FIG. 4a is an illustration of a connecting lever 5 and a float 4 showing a fixed position of a ring, and FIG. 4b is a longitudinal cross section of a part designated as 4b in FIG. 4a to show the detail of the ring fixation. In the example described above, the maximum output is induced with second mode vibration having a wave length, a half of which equals 2/3 of total length of the connecting lever, and first mode vibration is suppressed.
e) Substances having a large substance factor defined as E/γ are preferable as materials for a connecting lever, but in view of industrial use, a property of corrosion resistance of materials to environmental substances existing in the target structure to be detected the liquid level is considered at first and substances having good corrosion resistance to the environmental substances are selected, and later, it is necessary to select materials for the connecting lever in view of large substance factor from the substances having good corrosion resistance. A connecting lever which is preferable for suppressing fluctuations is obtained by composing the connecting lever having a structure described above in a) to d) with materials selected as described in e).
All of the structures of the connecting lever described in a) to e) are the structure to make the natural frequency f of the connecting lever large, and any of the structures has an effect to suppress fluctuations based on a relation that the strength a of fluctuation is proportional to the reciprocal number of natural frequency f of the connecting lever.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a is an illustration of a float type liquid level meter related to an embodiment of the present invention,
FIG. 1b is a partially cutaway section showing the detail structure of a part designated as 1b in FIG. 1a,
FIG. 2 is a conceptual view showing generic vibration mode of a connecting lever,
FIG. 3a is an illustration showing a connecting lever and a float according to the prior art,
FIG. 3b is an illustration showing a float and a connecting lever which has a structure relating to the present invention,
FIG. 3c is a transverse section of the connecting lever according to the prior art,
FIG. 3d is a transverse section of a connecting lever showing one of the embodiments of the present invention,
FIG. 3e is a transverse section of a connecting lever showing one of the embodiments of the present invention,
FIG. 3f is a transverse section of a connecting lever showing one of the embodiments of the present invention,
FIG. 3g is a transverse section of a connecting lever showing one of the embodiments of the present invention,
FIG. 4a is an illustration of a connecting lever and a float related to one of embodiments of the present invention to show a fixed position of a ring,
FIG. 4b is a longitudinal cross section of a part designated as 4b in FIG. 4a to show the detail of the ring fixation,
FIG. 5 is a schematic block diagram showing an embodiment of a water level regulating system using a float type liquid level meter according to the present invention,
FIG. 6a is a partially cutaway view of a connecting lever and a float according to the present invention,
FIG. 6b is a partially cutaway view of a connecting lever and a float according to the prior art,
FIG. 7a is a recording chart of a liquid level detection showing an example of a liquid level detection of a water separator according to the prior art, and
FIG. 7b is a recording chart of a liquid level detection showing an example of a liquid level detection of a water separator relating to one of the embodiments of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Example 1
One of the embodiments of the present invention is described in detail referring to from FIG. 5 to FIG. 7b.
FIG. 5 is a schematic block diagram showing an embodiment of a water level regulating system of a storage tank using a float type liquid level meter relating to the present invention. A float type liquid level meter 10 is connected to a storage tank 11 with connecting pipes 7. Based on an output from the float type level meter, a controller 12 controls an inlet regulating valve 13 and an exit regulating valve 14 to maintain water level in the storage tank constant.
FIG. 6b is a partially cutaway view showing a structure of a conventional connecting lever and a float used in a liquid level meter of prior art which is installed on a water separator in an electric generating turbine plant. Total length of the connecting lever from an upper supporting point which is connected to an apparatus for detecting buoyancy to a bottom base line of the float is determined depending on a distance from a position where the liquid level meter is installed to a liquid level. The connecting lever is comprised with a stainless steel solid rod having 280 mm in total length and 5 mm in diameter, but values of the length and the diameter of the connecting rod are described as one of examples of prior art and are not to be any limitation of the present invention. A result of a liquid level detection using a liquid level meter having the conventional connecting lever 5 and the float 4 is shown in FIG. 7a as an example of prior art. Referring to FIG. 7a, where passing time is shown in a horizontal axis and liquid level detecting values are shown in a vertical axis as real liquid level is put as a base line. There are many fluctuations in the liquid level detecting values and the maximum fluctuation is recognized as ranging to about 10% of full scale in a period shown in the FIG. 7a.
On the other hand, FIG. 6a is an illustration of a float 4 and a connecting lever 5 using in a liquid level meter related to the present invention which is used at the same place and under the same condition as the liquid level meter of prior art described before. Referring to FIG. 6a, the outer diameter and the length of the float 4, and the total length from the upper supporting point to the bottom line of the float are the values determined with a premise that the liquid level meter is used at the same place and under the same condition as the liquid level meter of prior art which is described above, and same values as the example of prior art shown in FIG. 6b, but the feature of the present embodiment lies in a structure of the connecting lever 5. That is, the total length of the connecting lever 5 of the embodiment is same, 280 mm, as the total length of the connecting lever of prior art described above because the connecting lever of the embodiment is used at a same position of the connecting lever of prior art, but a structure of the connecting lever of the embodiment is a cylinder having 13.8 mm in outer diameter and 9.4 mm in inner diameter in contrast with the connecting lever of prior art which is comprised with a solid rod having 5 mm in diameter.
By using a cylinder for a connecting lever, a shape factor in the embodiment, that is a value of a secondary moment of a cross section, I, divided with an area of the cross section, A, becomes 17.43 mm 2 , and the value equals almost eleven times of a shape factor, 1.56, of the conventional connecting lever described above. Consequently, a natural frequency of the connecting lever, f, becomes larger by almost three times, and hence, a strength of fluctuation, a, decreases to less than one third of the fluctuation of the example of the conventional liquid level meter based on a relation, a∝1/f.
The effect described above was confirmed with a practical use of a float type liquid level meter related to the present invention. A recording chart of a liquid level of a water separator determined with a float type liquid level meter having a connecting lever 5 related to the present invention and a float 4 used at the same position and under the same condition as a conventional float type liquid level meter is shown in FIG. 7b as designated as a present invention. Referring to FIG. 7b, a horizontal axis shows time passing at liquid level determination, and a vertical axis shows liquid level detecting values as real liquid level is put as a base line.
In comparing with the recording chart of an conventional level meter of prior art shown in FIG. 7a, a liquid level detecting values shown in FIG. 7b are very stable, and the strength of fluctuation decreases to about 2% of full scale, that is, about 1/2 to 1/4 of the example of prior art. The result of a practical use described above reveals that an effect of the present invention to suppress a strength of fluctuation is obvious.
Example 2
Another embodiment of the present invention is described referring to FIG. 2, FIG. 4a, FIG. 4b, FIG. 6a, and FIG. 6b.
FIG. 4a is an illustration showing a composition of a float 4 and a connecting lever 5 (for example, an elongated hollowed body) which has a structure to suppress large fluctuations by inserting and fixing of ring bodies on circumferential surface of the connecting lever at intermediate positions for avoiding first mode of vibration of the connecting lever, and FIG. 4b is a longitudinal section illustrating an examples of a fixing status of a ring body on a circumferential surface of the connecting lever.
With FIG. 6b, an example of embodiments wherein the present invention is applied to a conventional connecting lever 5 is described in the following.
The conventional connecting lever 5 is comprised with a solid rod having 5 mm in diameter and 280 mm in length, and the connecting lever vibrates with modes of a several orders as shown in FIG. 2 when the connecting lever vibrates with one end supporting at a point connected to an apparatus for detecting buoyancy. Among vibrations, the vibration of the first order mode causes a maximum fluctuation in a detecting signal of liquid level, and hence, it is important to eliminate the vibration of the first order mode in aiming to suppress fluctuation in the output signal of liquid level. Therefore, a connecting lever relating to the present invention is comprised with inserting a steel ring having 18 mm in outer diameter, 5.2 mm in inner diameter, and 6 mm in thickness on a circumferential surface of the connecting lever and fixing with welding at a place where it is 93 mm upward from the connecting point of the float and the connecting lever, that is, a position of 1/3 of the total length of the connecting lever. When vibration is transmitted to the connecting lever having the structure described above, an inertia of the weighted ring causes making a node at the place where the ring fixed and the connecting lever vibrates with vibration modes of higher than the second order mode, and the first order vibration is excluded. Consequently, large fluctuations which is caused by the vibration of the first order mode is suppressed, and an effect to obtain stable output signals of the liquid level is obvious.
Depending on the present invention, fluctuation in liquid level output signals of a float type liquid level meter is suppressed. An example of embodiments shows that the fluctuation in liquid level output signals of a float type liquid level meter relating to the present invention decreases to about 1/10 of the fluctuation obtained with a conventional float type liquid level meter of prior art, and stable output signals indicating liquid level are obtained. Consequently, a detection of liquid level becomes more precise and, in a case using a float type liquid level meter relating to the present invention or a float type liquid level transmitter relating to the present invention in a liquid level regulating system, it becomes possible to set a time lag element small because of the stability of the output signals, and a response of the regulating system to a change of liquid level becomes fast and a performance of the liquid level regulating system is improved.
The improvement described above brings an obvious effect to increase a total reliability and a total stability of a various plants which adopt a float type liquid level meter related to the present invention and a float type liquid level transmitter related to the present invention. | A float type liquid level meter is provided having an enhanced resistance against vibration transmitted from outside of the float type liquid level meter. The inventor obtained a finding that an external vibration is amplified with a connecting lever which is composing a part of the float type liquid level meter and a fluctuation of an output signal of the float type liquid level meter is proportional to the vibration of the connecting lever. An enhanced resistance against vibration is achieved by providing a connecting lever having a structure which prevents the connecting lever from generating vibration of a low order mode. | 6 |
BACKGROUND OF THE INVENTION
This present invention relates to wireless networks. More particularly, the invention relates to detecting fraud in the use of wireless network services.
As the use of mobile wireless terminals in wireless networks increases, a serious challenge confronting wireless network service providers is reducing, and even eliminating, fraudulent access of intruders and imposters to wireless network services as well as their unauthorized use of the wireless network services. Fraudulent access to network services may occur as a result of theft and subsequent illegal use of one of the following: i) a mobile wireless terminal (which will be referred to as a “terminal” henceforth) that belongs to an authorized subscriber of their respective wireless network services, ii) a subscriber's user identification module (UIM), which may be a detachable security device without which a terminal may not be activated or connected to a network, or iii) a subscriber's security association (SA), which is an index to the abstraction of the details of the subscriber security scheme that may be placed in packets transferring a subscriber's data across the network. Such fraudulent access to network services may result in the loss of significant revenue for wireless network service providers as well as financial loss and personal inconvenience for individual users who are the victims of such fraud.
Currently, a subscriber who no longer has her terminal or UIM in her possession, as a result of, for example, theft, accident or even carelessness, may simply report the loss of the terminal or UIM to the wireless network service provider to which she subscribes, and then wireless network service provider may revoke or even terminate terminal access to the wireless network or inhibit registration or connection to the wireless network by the UIM to avoid inadvertent or fraudulent use of the wireless network services by someone other than the subscriber to the wireless network or appropriate user of the terminal. However, since the subscriber may be otherwise preoccupied, or even in view of the increasingly reduced size of terminals and the detachable nature of UIMs, the absence of a terminal or UIM from a subscriber's possession may not be noticed or detected until after a significant amount of fraudulent or otherwise unauthorized use of the terminal or UIM by an unauthorized user has occurred. Moreover, a subscriber may not be aware of the theft of her SA with the network through an intruder's electronic eavesdropping on the wireless channel. In such cases, the subscriber to the wireless network may be unaware that her terminal or UIM or SA has been used for fraudulent or otherwise inappropriate access to the wireless network services until she receives an invoice from the wireless network service provider that includes a detailed record of access to the wireless network services by her terminal or UIM, which may result in significant charges.
Thus, there is a need for a system and technique that protect wireless network service providers from the financial loss that result from the fraudulent or otherwise unauthorized access to and use of wireless network services, as well as protecting the subscribers of the mobile wireless network services from the financial loss and personal inconvenience that further result from such fraudulent or otherwise unauthorized use thereof.
SUMMARY OF THE INVENTION
The present invention provides a system by which a wireless network service provider, including the network operator, is able to detect fraudulent use of a mobile wireless terminal, a subscriber user's identification module (UIM) or a subscriber user's security association (SA) for accessing and using the wireless network services, regardless of whether or not the authorized subscriber is aware of such fraudulent use of her mobile wireless terminal, UIM or SA.
According to an aspect of the present invention, detecting unauthorized access to and unauthorized use of services in a wireless network includes recording a history of terminal location within the wireless network and dynamic monitoring of the terminal's registration patterns, analyzing the recorded history of location of the terminal within the wireless network, monitoring current location and registration patterns of the terminal within the wireless network, and requesting clarification when a deviation between said statistical analysis of the location and registration pattern of the terminal within the wireless network and the current location and registration pattern of said terminal within the wireless network is detected. The invention may be implemented in databases as well as control and transport entities of a network, either singularly or in combination with each other or further network entities.
BRIEF DESCRIPTION OF THE DRAWINGS
The scope of the present invention will be apparent from the following detailed description, when taken in conjunction with the accompanying drawings. The detailed description of example embodiments of the invention is provided as illustrations only, since changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description, in which:
FIG. 1 shows an example of a wireless network in which the present invention may be utilized.
FIG. 2 is a flowchart showing an example of a method according to the present invention.
DETAILED DESCRIPTION
In the following detailed description, example embodiments and values may be given, although the present invention is not limited thereto. Further, while example embodiments of the present invention will be described in conjunction with a method for detecting fraud in wireless networks as an example, practice of the present invention is not limited thereto.
FIG. 1 shows an example of a wireless network in which the present invention may be utilized. The example wireless network of FIG. 1 may include a plurality of cells 2 a , 2 b and 2 c that may provide a mobile terminal (hereinafter “terminal”) that belongs to a subscriber of services provided by the wireless network service provider with access to the network infrastructure, which may include, but is not limited to, an Internet Protocol (IP) infrastructure. Each of base stations BS 1 , BS 2 and BS 3 may serve as a transmitting and receiving station for terminals in the respective cells 2 a , 2 b and 2 c . The terminals may include, but are not limited to, telephones, pagers, laptop computers and other wireless transmitting and receiving systems. Therefore, based upon the services offered by the respective network service providers, the respective base stations BS 1 , BS 2 and BS 3 may or may not serve as an IP router, that is, the respective base stations may or may not have IP routing and processing capabilities.
Access gateways AG 1 , AG 2 and AG 3 , which may be provided for the respective cells 2 a , 2 b and 2 c , are edge IP routing and control entities that connect one or more of the base stations BS 1 , BS 2 and BS 3 to the network 1 . However, beyond the example network of the present application, it is noted that an access gateway may actually connect several base stations to a network, and further, in no way is the present invention limited to a network having only three cells or even a one-to-one ratio of base stations to cells. Authentication, authorization and accounting (AAA) entity 6 is a network operator entity for network 1 that receives, processes and accepts or denies registration requests for the terminal. Thus, the AAA entity 6 is able to dynamically monitor the registration patterns of the terminals.
The network 1 may further include geographic location manager (GLM) 3 that is a control/management entity for network 1 . GLM 3 may receive and store information pertaining to the geographic location of active or registered terminals. Such information pertaining to the geographic location of active or registered terminals may be gathered from satellite positioning systems including, but not limited to, the Global Positioning System (GPS), which is well known in the art of communications. For the present description, reference will be made to GPS, although the present invention is not limited to use of only GPS.
The GLM 3 may gather information regarding the geographic location of a terminal 4 in the network 1 to which the terminal is registered, and, based on the gathered information, the GLM may compute a probability density function, which is a normalized histogram, of the exact location of the active subscriber terminal 4 . The histogram may be refined with each additional geographic location update of the subscriber terminal 4 , which may occur, for example, every time the subscriber terminal 4 re-registers with the AAA 6 of network 1 as the subscriber terminal 4 moves from one cell to another, from cell 2 a to 2 b in FIG. 1 , or at predetermined time intervals. The GLM 3 may provide normalized histograms regarding the geographic location of subscriber terminal 4 across network 1 to network control entities of the operator, which may include, but is not limited to, AAA 6 and the transport entities of the respective cells, which include, but are not limited to, AG 1 -AG 3 .
Explanation of an example embodiment of invention will now be further explained in reference to the flow chart of FIG. 2 . The example embodiment further refers to FIG. 1 in which a registered terminal, which is subscribed to a particular network, moves among cells 2 a through 2 c in the network 1 , although the present invention and application thereof is in no way limited thereto. In addition, the example embodiment of the invention may be implemented by a program run by the network entities described herein.
After subscription to the services offered by the network services provider associated with network 1 , as terminal 4 moves from cell 2 a to 2 b , for example, terminal 4 may re-register its location with the network operator of the network 1 in order to maintain a connection to the network 1 . GLM 3 may gather information from a positioning system to monitor all movements and corresponding locations of the terminal 4 within the network 1 and may further maintain such tracking information in a GLM database, as in step 20 . With each recorded location of the terminal 4 within the network 1 , or at predetermined time intervals, GLM 3 may update a normalized histogram as in step 22 , which includes a probability distribution, of the exact location of the terminal 4 . GLM 3 continues to monitor movements and corresponding locations of the terminal 4 in network 1 , as in step 22 , and with each recorded location of the terminal 4 within the network 1 , or at predetermined time intervals, GLM 3 may update the histogram for terminal 4 locations. The AAA entity 6 , or any other designated operator entity, may monitor the locations and registration patterns of terminal 4 by retrieving the exact location of terminal 4 as well as the probability distribution of locations of terminal 4 from GLM 3 upon receiving a registration request from terminal 4 , as in step 24 .
Thus, a normalized histogram for the behavior of terminal 4 within the network 1 may be established. The histograms may include information regarding the geographic locations and registration patterns of the terminal 4 in the network 1 . When a deviation from any of the patterns provided in the histograms for terminal 4 has been detected, as in step 26 , the network operator entities, including AAA 6 and AG 1 -AG 3 , may be alerted that terminal 4 , or its associated UIM or SA, may not be currently used by the subscriber thereof. Then the network operator entity, including AAA 6 or any other entities, which are provided with the updated histogram for terminal 4 , may prompt a clarification protocol to determine whether terminal 4 is being used fraudulently, as in step 28 .
A deviation from an established pattern of use for terminal 4 may result from, as examples only, theft, accident or loss, which results in terminal 4 , or its associated UIM or SA, being used by someone other than the authorized subscriber to the wireless network. Further, a deviation from an established pattern of use for terminal 4 may result from a clone or intruder illegally impersonating the terminal 4 or its UIM or SA by other unauthorized electronic means, thus impersonating an authorized network subscriber.
A further example of a deviation from an established pattern of use for terminal 4 may include frequent repetitive attempts by a terminal for registration or connection to a network 1 from the same location. Such case may include a subscriber making repeated, unsuccessful attempts at registering for the network services provided on the network 1 , with such registration or connection attempts being denied, often because a clone of terminal 4 , is already connected to the network 1 . In such case, a network operator including AAA 6 or any of the network operator entities that are provided with the histograms to monitor the activities of terminal 4 on network 1 may prompt the clarification protocol after a threshold number of attempts at registration or connection for a terminal 4 to network 1 have been denied within a threshold amount of time.
Another example of a deviation from an established pattern of use for terminal 4 may include a network operator including AAA 6 or any other operator entities that monitor the network activity of terminal 4 on network 1 receiving a registration or connection request from terminal 4 from an unlikely geographic location which has not been previously recorded in the GLM database. Although a registration or connection request from a new geographic location does not necessarily indicate fraudulent use of terminal 4 , the network operating entities may prompt the clarification protocol to thereby protect the authorized subscriber, as well as the wireless network service provider, from fraud.
Yet another example of a deviation from an established pattern of use for terminal 4 may include a network operator entity including AAA 6 or any other operator entities that monitor the network activity of terminal 4 on network 1 receiving registration or connection requests from a subscriber for terminal 4 that are inconsistent and therefore suspicious. For example, if the registration or connection requests come from different geographic locations within an improbable time frame, for instance registration or connection requests are made in New York, N.Y. and Washington, D.C. within five minutes of each other, the network operator entities may understand that such requests within such a short amount of time are physically impossible, and therefore the network operator entities may then prompt the clarification protocol.
A further example prompt for the clarification protocol may include an outside party contacting the network operator to report difficulty in contacting the subscriber user of terminal 4 .
The clarification protocol, shown in clarification request step 28 , which is intended to determine whether terminal 4 is being used fraudulently may include a step of terminating access to network 1 by terminal 4 or denying re-registration of terminal 4 as it moves from cell 2 a to cell 2 b , as in FIG. 1 for example. In the alternative, the clarification request step 28 may include a step of allowing re-registration of the terminal 4 within a new cell in the network 1 and then transmitting a query to the terminal 4 requesting verification that the current user of terminal 4 is the actual subscriber. The query may be an automated or operator-initiated text or audio message, depending on the capabilities of the terminal 4 , which is transmitted before allowing further activity on the network 1 by the terminal 4 . Such query may include a request for predetermined subscriber information or predetermined security information including, but not limited to, social security information, mother's maiden name, date of birth, etc. If the current user of the terminal 4 is not able to respond to the query in a satisfactory manner, all activities by terminal 4 on the network 1 may be terminated, as in step 30 . At such point, the network operator may implement further security measures including, but not limited to, contacting the authorized subscriber using predetermined security protocols including alternative forms of communication, contacting appropriate law enforcement authorities and prohibiting all future network activity by terminal 4 until the authorized subscriber has contacted the network service provider and satisfactorily proven that the terminal 4 is being used by an authorized user. Otherwise, no fraudulent use is found, and service on network 1 may continue for terminal 4 , as in step 30 ′.
This concludes the description of the example embodiments. Although the present invention has been described with reference to illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the scope and spirit of the principles of the invention. More particularly, reasonable variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the foregoing disclosure, the drawings and the appended claims without department from the spirit of the invention. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art. | A system and method are provided by which a network operator is able to detect fraudulent use of a subscriber's terminal, regardless of whether or not the subscriber is aware of the fraudulent use of her terminal. Detecting unauthorized terminal use in a wireless network includes recording a history of terminal location and registration patterns, analyzing the recorded history of location and registration patterns of the terminal, monitoring current location and registration patterns of the terminal, and requesting clarification when a deviation between said statistical analysis of the location and registration patterns of said terminal and said current location and registration patterns of said terminal is detected. | 7 |
This application is a division of co-pending U.S. application Ser. No. 459,058, filed Jan. 19, 1983, now U.S. Pat. No. 4,483,543.
FIELD OF THE INVENTION
Tnis invention relates to ring seals and in particular to resilient ring seals with supporting and clearance closing end rings.
DESCRIPTION OF THE PRIOR ART
Molded seal elements such as those shown on page 26 of "Production Packer Equipment and Services", catalog publication OEC 5120D of Otis Engineering Corporation, P. 0. Box 819052, Dallas, Texas 75381-9052, have been successfully used to sealingly engage and maintain pressure seals between well tools and well tools and tubing or casing used in earth wells.
Seals of the type shown in U.S. Pat. No. 4,109,716 to Carlos R. Canalizo entitled "SEAL" have been used to effectively seal tools at desired depths inside well tubulars. Another example of a similar seal is shown in U.S. Pat. No. 4,305,595 to Miyagishima and Carbaugh.
The aforementioned seals are of the diametral "interference" type. A diametral interference type seal is typified by the inside diameter of the seal being smaller than the tool mandrel outside diameter over which it is installed and the expanded outside diameter of the seal being greater than the inside diameter of the seal bore into which the seal is inserted and radially compressed to sealingly engage.
Pressure differential sealing ability of interference seals is dependent on many factors including strength of the resilient material in compression, in tension, and in shear and percent loss of those strengths because of elevated temperatures and chemical attack in earth wells, the amount of resilient material interference and the amount of clearance between tool outside diameter or seal supporting end ring outside diameters and the inside diameter of the bore engaged by the seal.
The aforementioned seal elements typically utilize a great amount of diametral interference. Supporting rings of harder, stronger material are usually connected to the resilient seal material by bonding during the resilient material molding process. The large amount of interference and bonded supporting rings are required to withstand high temperatures and pressures encountered in modern deeper earth wells. One result of this large amount of interference is that a large longitudinal force is required to radially expand the resilient seal material when installing over a tool mandrel and to radially compress the resilient material to insert into a bore for sealing engagement. Forced insertion and resulting stress concentrations at support ring corners frequently tear the support ring bonds. Shear stresses induced into the resilient material also contribute to permanent damage to the seal. As increasing pressure differentials are placed on the engaged seal, connecting bonds may be partially or completely destroyed, and the resilient material is forced into any clearance between end support rings and seal bores inducing shear, tensile and/or compressive stresses into the material at the seal material/support ring interface. Excessively high pressures can cause extrusion of the resilient material through very small clearances resulting in complete seal failure.
SUMMARY OF THE INVENTION
The molded seal configuration of the present invention utilizes generously radiused convex internal and external resilient material contours bonded at both ends to support rings which provide stronger resilient material to support ring connections and reduce internal resilient material stresses and extrusion when the seal is in use. Tests of this seal configuration reveal that much lower insertion forces are required for a given amount of diametral interference. When using wireline methods for installing tools in tubing seal bores, great forces for radial seal compression and insertion are not available. These seals are not easily damaged by insertion and high pressures, as the radiused resilient material and support rings effectively reduce or eliminate inducement of excessive compressive and shear stresses into the resilient material and ring to seal bonds remain intact much longer.
As elevated temperatures encountered in today's deep earth wells cause softening of resilient materials used for molded seals, high pressures present may tear resilient material support ring bonds and cause extrusion of softened seal materials through very small support ring-seal bore clearances, resulting in seal failure. Configurations of the present invention seal utilize the uniquely contoured resilient material with pressure deformable support ring configurations which provide resilient material to support ring connection after bond tear or failure, and reduce or eliminate clearance between support ring outside diameters and seal bore inside diameters to enhance seal pressure holding capabilities.
An object of this invention is to provide a seal ring requiring less force to install on a seal mandrel and to insert into a seal bore.
Another object of this invention is to provide a seal ring wherein resilient material stresses induced by sealing great pressure differentials are greatly minimized.
Another object of this invention is to provide a seal ring configuration which prevents excessive resilient seal material stress concentrations around end support rings.
An object of this invention is to provide seal support ring configurations which enhance sealing ability by remaining connected to the resilient material after resilient material support ring mold bonds partially or totally fail.
Also, an object of this invention is to provide seal support rings which further enhance the sealing ability of the resilient material configuration by reducing or closing the clearances sealed.
Also, another object of this invention is to provide support rings for a resilient seal which both reduce sealed clearances and are mechanically connected to the resilient material.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a half-sectioned elevational view of the seal of this invention with radiused end support rings.
FIG. 2 is a view in elevation of the seal of FIG. 1 on a tool mandrel inserted into and sealingly engaging a seal bore.
FIG. 3 is a cross-sectional view of the seal of this invention with connected support rings.
FIG. 4 is a view in cross-section of the seal of this invention with deformable two-piece support rings.
FIG. 5 is also a cross-sectional view of the seal of this invention with deformable connected support rings.
FIG. 6 is a cross-sectional view of the seal of this invention with connected one-piece support rings.
FIG. 7 is another cross-sectional view of the invention seal with deformable support rings.
FIG. 8 is a cross-sectional view of the seal of this invention with connected deformable support rings.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows the basic molded resilient seal configuration of this invention wherein radiused one end support rings 1 are connected to both ends of a resilient moldable material portion 2, which is formed and connected by bonding to the support rings during the molding process. Typical of the resilient material portion 2 are a middle section 2b, which is curved convexly on the outside and inside surfaces, and cylindrical sections 2a formed on both ends of section 2b. The centers and magnitudes of radii forming the outside and inside of section 2b are selected by design calculation to intersect the cylindrical sections 2a outside and inside near the support rings for minimum cross-section compression and ease of installing the seal over a mandrel or into a seal bore. Sufficient resilient material and space for material movement is provided without the material being compressed between support rings and seal bore, and possibly cut. High pressure differentials are sealingly retained without high shear and compressive stresses in the resilient material near the support rings. For this purpose, angles B in FIG. 1 should be preferably 5-30 degrees and less than 40 degrees resulting in lower over mandrel installation and seal bore entry forces as angles B decrease during installation and insertion in a seal bore.
Resilient material compressive and shear stresses are minimized, when sealing high differential pressures, by the large radius support rings which also provide greater surface areas for enhanced connecting bonds of resilient material to support rings. Angles A, FIG. 1, have been determined to be preferably 30-35 degrees, within a workable range of 15-75 degrees.
FIG. 2 shows the seal of FIG. 1 installed over tool mandrel M and retained in sealing engagement on the tool mandrel smooth turned outside diameter by retaining ring R engaged in groove G. The tool mandrel with seal S has been inserted into and sealingly engages seal bore B, and pressure differential P force has moved the molded resilient material toward the support ring-seal bore and turn clearances C.
During rigorous tests of the seal configuration of FIG. 1, under extremely high pressures and temperatures, frequent and rapid pressure reversals eventually tore the support ring resilient material bonds partially or completely. The support ring configurations of FIGS. 3-8 were developed to prevent extrusion and bond tears and furnish better support for the resilient material portion of the seal ring.
FIG. 3 shows the molded seal portion 2 of FIG. 1 with support rings of a cross-section which remain connected to the resilient material even though the mold formed connecting bond between support ring and resilient material partially or totally fails. This additional molded connection has been found to increase the longevity and/or the pressure holding capability of seals not having connected support rings. A number of openings 1 are formed in a tongue portion 3 of the support rings 4. During the molding process, resilient material bonds to the support rings and bonds to itself through the openings, providing tne additional mechanical connection.
FIG. 4 shows the seal portion 2 of FIG. 1 to which four "L" cross-section concentric support rings 1 and 3 form an inward facing "U" cross-section and are bonded at each end to the resilient material during molding. As differential pressure thrust moves and compresses sealingly engaged resilient seal material, the deformable supports away from high pressure are deformed and spread by the compressed resilient material within, to close clearances sealed and increase the pressure holding ability of the seal.
FIG. 5 shows the bonded seal material and support rings of FIG. 4 wherein a number of pins P, having shoulders on one end, have been installed from inside through holes or openings 1 in "U" section support rings (pair of 2's) to keep the pins from falling out. The resilient material is molded around and bonded to the pins to provide a mechanical connection after bond failure.
FIG. 6 shows one-piece "U" cross-section end support rings mechanically connected and bonded to the molded material configuration of FIG. 1, by molding around pins 1 bradded in support ring openings 2.
FIG. 7 shows deformable one-piece "U" section support rings 1 bonded to the molded seal portion 2 of FIG. 1. The support rings of FIG. 7 (like those of FIG. 4) may be deformed by compressive forces induced in the resilient seal material by differential pressure thrust and spread to reduce support ring-seal bore clearances and increase differential pressures held by the seal. If deforming forces become great enough, the deformable support rings may be moved outwardly and inwardly far enough to contact the outside of the seal mandrel and inside of the seal bore and close clearances into which the resilient material may be forced or possibly extruded through, increasing to a maximum pressure holding capabilities of the seal. If deforming force induced stresses exceed the support ring material elastic limit, the support rings will be permanently deformed and will not return to their original shape when the deforming force is reduced.
FIG. 8 shows the seal of FIG. 7 wherein the deformable support rings have been rolled or crimped inwardly before molding, to remain connected to the molded resilient material portion after the support ring-resilient material bond has been partially or totally destroyed. | A molded resilient ring seal with support rings mold bonded or bonded and connected to both ends. The molded resilient material portion of the seal utilizes unique contouring to reduce internal resilient material stresses during use, enabling the seal to seal higher pressures at elevated temperatures for longer periods of time. A number of support ring configurations are also disclosed, which further enhance sealing ability of the resilient material. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to the field of electrically alterable read-only semiconductor memories. More specifically, this invention is described with respect to the type of memory that utilizes floating gate field effect transistors as storage cells. Each storage cell, which may also include a selection transistor therein, stores one bit of information. Typically, eight bits or eight storage cells are logically grouped together to form a byte. The bytes are organized in an array of rows and columns. Thus, if 16 columns are utilized with each column containing 128 rows, an array of 2,048 bytes is produced on a single semiconductor chip.
The prior art recognizes the desirability for being able to clear these memories one byte at a time if desired. Such a feature permits the user to change the contents of a single eight-bit byte by erasing only that byte and then entering new data into the byte. Without the feature, it would be necessary to empty the entire contents of the memory into a temporary buffer memory where the required byte could be altered and then to rewrite all 2,048 bytes back into the semiconductor memory chip.
One typical prior art approach for clearing a single byte involves positioning a special transistor in the vicinity of each byte on the chip, operable in response to an X address signal and a Y address signal, to clear only the eight storage cells in the selected byte. The disadvantage of this prior art approach is that 2,048 additional transistors are required to operate the 16 by 128 byte array mentioned above. Furthermore, each column of bytes requires an extra metal line to supply the Y address signal to the special transistors associated with each byte in that column. These additional transistors and metal lines reduce the density of parts on the chip and require larger chips to accommodate the same storage capacity. The present invention, however, permits greater density in the memory array by providing a circuit wherein the selection devices necessary to select an individual byte for clearing may be positioned at the periphery of the array rather than dispersed throughout the array. As a result, each column may operate with one less signal line and one less transistor per byte.
SUMMARY OF THE INVENTION
Briefly, the present invention contemplates means to isolate the ground path for each column of bytes during the clearing process so that the appropriate clearing signal can be introduced through the conventional input/output lines that are normally used to write data in and read data out of the memory. In order to prevent unselected bytes from being cleared, each of the columns is connected to a weak pull-up transistor which operates to prevent a clearing signal from accidentally being present in the bytes in the column unless the weak pull-up signal is overpowered by the intentional introduction of a clearing signal, which happens only at a specific selected byte. Hence, it is unnecessary to use a switching device at each byte in order to electrically isolate the byte. Rather, the present invention can clear a particular byte by introducing a clearing signal in such a way that the signal will only be strong enough at the selected byte to achieve a clearing operation.
BRIEF DESCRIPTION OF THE DRAWING
The drawing presents a schematic diagram of the byte clear circuit utilized in the preferred embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawing, a typical memory is schematically diagrammed, along with some typical peripheral circuits, and also the specific peripheral circuits necessary to accomplish the byte clear function of the present invention. One byte is completely diagrammed inside the dashed line 10. Byte 10 comprises eight storage cells, 12 through 19. Each storage cell is essentially identical and includes a floating gate transistor 20 and a select transistor 22. The storage cells 12 through 19 are connected to a common ground line 23 at one end and coupled at the other end through their select transistors 22 to a series of output lines 30 through 37. Output lines 30 through 37 connect respectively to a group of input/output lines 28 through a series of eight Y address selection transistor 24.
Byte 10 may be thought of as the top byte in a column of bytes in which the other bytes in the column are represented by box 25 in the drawing. Additional columns of bytes are represented by box 26 in the drawing. In conventional memory writing and reading operations, individual bits or bytes may be selected by introducing signals X 1 through X N and P 1 through P N from a row address select means 27 and signals Y 1 through Y N from a column address select and byte clear logic means 29. The circuitry necessary to create the desired address signals is well known to those skilled in the art and therefore not discussed in detail herein.
For the purposes of explanation, it is convenient to refer to a typical storage cell such as cell 12. Cell 12 may be cleared by the introduction of 0 volts at point 43 in combination with the application of a 20 volt P 1 signal to a control gate 38 in floating gate transistor 20. In so doing, a charge will be caused to jump from the drain region of transistor 20 to the floating gate. The charge on the floating gate inhibits current flow in device 20 during the application of a conventional 5 volt P 1 read signal to the control gate 38. In a like manner, all of the other storage cells 13 through 19 may be cleared by the application of a 20 volt P 1 pulse on program line 39 from row address select means 27 in combination with the application of 0 volts to the points 43 on each of transistors 20.
In order to clear out one particular selected byte, three signals are required. Column address select and byte clear logic means 29 provides these three signals. Logic 29 introduces a 0-volt signal on input/output lines 28. In addition, byte 10 is selected in a conventional manner by the application of a Y 1 signal on line 27 which operates to turn on a series of eight address selection transistors 24, so as to connect output lines 30 through 37 to input/output lines 28 and the 0 volt signal thereon. Transistors 24 thus present a 0 volt signal to each of the select transistors 22 in the storage cells 12 through 19. The selection of byte 10 is further accomplished by the generation of an X 1 signal on line 41 from row address select means 27 which operates to turn on transistors 22 so as to convey the 0 volt signal to point 43 in each of the storage cells. The combination of this 0 volt signal in the drain regions of floating gate transistors 20 with a 20 volt P 1 signal on line 39 clears all of the floating gate transistors 20 in the storage cells 12 through 19. Hence, the entire byte 10 is cleared simultaneously.
Since the selection signals X 1 and P 1 are transmitted across an entire row of bytes and through several other columns of bytes 26, other bytes could be cleared as well if they were permitted to have an accidental 0 volt signal on their respective output lines. To prevent this, the output lines of all the other columns are caused to have a higher voltage by means of a clear prevention signal device 44, which operates through a series of transistors 40, and in response to a signal V CP on line 42, to apply a clear prevention signal to output lines 30 through 37. In the preferred embodiment, clear prevention signal means 44 comprises a high impedance, weak pull-up, transistor, connected as shown to the output lines 30 through 37 in byte 10. Weak pull-up transistor 44 is also connected to a source of voltage V pp , which in the preferred embodiment is chosen to be 20 volts. This 20 volt signal is applied to the output lines 30 through 37.
However, in the case of byte 10, the 0 volt signal applied by input/output lines 28 is sufficient to overcome the 20 volt signal which transistor 44 is attempting to establish and establish itself on output lines 30 through 37. As a result, in the case of byte 10, the storage cells 12 through 19 are cleared anyway. However, in the case of the other columns 26, there is no 0 volt signal applied through output lines 28 because the signal Y 1 on line 27 is not applied to the other columns 26. The other columns 26 are connected to other column pull-ups 46, as shown in the drawing, and since the other column pull-ups 46 are also activated by the signal V CP on line 42, all of the other columns will be prevented from having a 0 volt signal on their output lines corresponding to lines 30 through 37. Thus, none of the bytes in the other columns will be cleared.
Another way that the 0 volt signal on output lines 30 through 37 could reach other columns would be through an accidental ground loop path. To prevent this, each of the ground lines 23 of an individual column are isolated from the ground lines in other columns by means of an isolation means which in the preferred embodiment comprises a ground isolating transistor 52. Transistor 52 is turned off during a byte clear operation by a signal V GP presented by logic circuit 29 through a line 50. The signal on line 50 also goes to a series of other column ground gates 54 which control the connections on the ground lines 23 in the other columns 26. Thus, during the byte clear process, the grounds for each column of bytes are isolated from each other and floated through the action of a number of transistors 52 and 54 operating in response to the signal on line 50.
It may be seen, therefore, that all of the columns are urged toward a positive voltage on their output lines by means of a series of weak pull-up transistors 44 and 46 so that a clear signal is effective only in the specific byte at which the 0 voltage on output lines 28 is presented. The Y N signal from logic 29 controls the introduction of the 0 volt signal on lines 28 into the selected byte (byte 10 in the case of the drawing) so that it can overpower and dominate the weak pull-up transistor 44 and allow a clearing action to take place. Various modifications to the circuits shown will occur to those skilled in the art, including other means to isolate the column grounds from each other and other means to urge the column voltages positive during the byte clear operation. Accordingly, we intend to be bound only by the, appended claims. | A circuit for clearing selected bytes in a semiconductor electrically alterable memory in which the ground lines for any one column of bytes is isolatable from the ground lines for other columns, all the outputs for the bytes are urged toward a non-clearing condition, and the outputs for only the selected byte are used to introduce a clearing signal that dominates the non-clearing condition. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. provisional application Ser. No. 61/053,811 filed on May 16, 2008, incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with Government support under Grant No. FA9550-05-1-0138, awarded by the Air Force Office of Scientific Research (AFOSR). The Government has certain rights in this invention.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
Not Applicable
NOTICE OF MATERIAL SUBJECT TO COPYRIGHT PROTECTION
A portion of the material in this patent document is subject to copyright protection under the copyright laws of the United States and of other countries. The owner of the copyright rights has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the United States Patent and Trademark Office publicly available file or records, but otherwise reserves all copyright rights whatsoever. The copyright owner does not hereby waive any of its rights to have this patent document maintained in secrecy, including without limitation its rights pursuant to 37 C.F.R. §1.14.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the manufacture of nanocomposites comprising nano-sized materials and polymer resin, and more specifically to the manufacture of nanocomposites using monomer stabilization.
2. Description of Related Art
Vinyl ester resin has been widely used in the marine (Naval submarine) industry due to its good mechanical properties such as large Young's Modulus and tensile strength, and its superior resistance to moisture and chemicals. As a thermosetting material, vinyl ester resin can be cured easily in an ambient condition and was reported to strongly depend on curing temperature, initiators and accelerator levels. Separately, nano-sized materials are of tremendous interest in different fields of chemistry and physics due to their unique magnetic properties such as high coercivity and chemical catalytic properties inherent with their small size and high specific surface area.
Polymeric nanocomposites reinforced with nanoparticles have attracted much interest due to their cost-effective processability and tunable physical properties such as mechanical, magnetic, optical, electric and electronic properties. Inorganic nanofillers dispersed into polymer matrices can stiffen and strengthen the nanocomposites, increase the electric and thermal conductivities, introduce unique physicochemical properties such as magnetic and optical properties, and even improve the shape replicability. The use of proper functional nanoparticles within a polymeric matrix renders the resulting nanocomposites applicable in devices such as photovoltaic (solar) cells, polymer-electrolyte membrane fuel cells, and magnetic data storage systems. The functional groups of the polymer surrounding the nanoparticles enable these nanocomposites to be used for various industrial applications, such as site-specific molecule targeting applications in the biomedical areas and explosive detection sensors. Recent investigations on nanocomposites reinforced with different ceramic nanoparticles, such as alumina, zinc oxide, iron oxide and copper oxide, have shown that the ceramic nanoparticle itself has some effect on the curing process and subsequent performance of nanocomposites.
Nonetheless, industrial applications of bare vulnerable metal nanoparticles are still a challenge due to their aggregation and easy oxidation. To achieve a stable nanoparticle usable system in the context of nanocomposites, metal nanoparticles are usually stabilized by a surfactant/polymer or a noble metal shell, which reduces the particle agglomeration in a colloidal suspension or protects them from oxidation in harsh environments. High particle loading, required for certain applications such as solar cells, electromagnetic interfaces (EMI), microwave absorbers and giant magnetoresistance sensors, usually has a deleterious effect on the mechanical properties due to the particle agglomeration and poor interfacial bonding between the nanoparticle and polymer matrix. Therefore, particles are functionalized by a surfactant or a coupling agent to achieve uniform particle dispersion in the matrix and chemical bonding at the interface. There still lacks a systematic study of the nanoparticle effect on the curing process for high-quality vinyl ester resin nanocomposite fabrication, especially for the case of reactive magnetic metallic nanoparticles. In addition, the functionalization of nanoparticles made the composite fabrication more complicated and costly.
Metallic multilayer giant magnetoresistance sensors (GMRs) have found wide applications in areas such as biological detection, magnetic recording and storage systems, and rotational sensors in automotive systems since the discovery of GMR in 1988. Compared with the metal-based multilayer GMR sensors, the polymer nanocomposite-based sensors would have the benefit of easy manipulation and cost-effective fabrication. However, the challenge is to obtain high-quality polymer nanocomposites with nanoparticles uniformly dispersed in the polymer matrix. In other words, to prevent particle agglomeration is an inherent challenge in the composite fabrication. In addition, the interaction between the nanoparticles and the polymer matrix plays an important role in the quality of the nanocomposite. Poor linkage, such as the presence of gas voids may result in deleterious effects on the mechanical properties of the nanocomposites.
BRIEF SUMMARY OF THE INVENTION
Overcoming one or more of these limitations, the present invention comprises an improved method to prepare reinforced resin nanocomposites without the need of surfactants or coupling agents. Instead, the present invention comprises the use of monomers for improving the dispersion of nano-sized materials and enhancing the particle/matrix interaction. The monomers, which importantly serve to stabilize the nanoparticles, are covalently bound onto the nanoparticle surface and copolymerize with non-bound monomers after introduction of a catalyst and a promoter that initiate polymerization. Without any additional surfactant or coupling agent, the resin is chemically bound onto the nanoparticle surface and protects the iron nanoparticles from agglomeration and oxidation. Physical characteristics, such as tensile strength and Young's Modulus, are larger than those of cured pure resin. The resulting magnetically harder nanocomposites with an increased thermal stability are ferromagnetic at room temperature and have potential applications in the marine systems, magnetoresistive sensors and microwave absorption systems.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only:
FIG. 1 shows DSC curves of the liquid pure resin and vinyl ester nanocomposites with different iron nanoparticle loadings.
FIG. 2 shows DSC curves of the vinyl ester nanocomposites after a 24-hour room temperature curing.
FIG. 3 shows TGA curves of the nanocomposites with different particle loadings after 24-hour room temperature curing.
FIG. 4 shows TGA curves of the nanocomposites with different particle loadings after post curing at 100° C.
FIG. 5 is an SEM micrograph of (a) the cross-section and (b) fracture surface after tensile test of the nanocomposites with a particle loading of 35 wt %.
FIG. 6 shows room temperature magnetic hysteresis loops of vinyl ester resin monomer stabilized iron nanoparticles and the iron nanoparticles reinforced vinyl ester resin nanocomposites with different particle loading.
FIG. 7 shows high-resolution carbon is XPS spectrum of THF washed vinyl ester/iron nanoparticle complex.
FIG. 8 shows magnetic hysteresis loops of the fresh and annealed vinyl ester monomer stabilized iron nanoparticles; inset shows the TEM micrographs of the as-received nanoparticles.
FIG. 9 shows (a) temperature dependent resistivity and (b) Ln (resistivity) as a function of T^ (−½) of as-prepared and heat-treated monomer stabilized iron nanoparticles; inset of (b) shows the MR of the annealed monomer stabilized nanoparticles.
FIG. 10 shows (a) hysteresis loops of as-prepared and heat-treated nanocomposites with a particle loading of 15 and 40 wt %, inset shows the SEM image of nanocomposite with a 40 wt % particle loading; and (b) TEM micrograph of the heat-treated nanocomposite, inset shows the SAED and HRTEM images of nanocomposite with a 40 wt % particle loading.
FIG. 11 shows temperature dependent resistivity of the nanocomposite with 20 and 40 wt % particle loading after heat treatment at 450° C.
FIG. 12 shows room temperature MR as a function of applied field for heat treated nanocomposites reinforced with a particle loading of 15, 20 and 40 wt %, respectively.
The features mentioned above in the summary, along with other features of the inventions disclosed herein, are described below with reference to the drawings. The illustrated embodiments in the figures listed below are intended to illustrate, but not to limit, the inventions.
DETAILED DESCRIPTION OF THE INVENTION
Referring more specifically to the drawings, for illustrative purposes the present invention is embodied and characterized by that shown in FIG. 1 through FIG. 12 . It will be appreciated that the apparatus may vary as to configuration and as to details of the parts, and that the method may vary as to the specific steps and sequence, without departing from the basic concepts as disclosed herein.
In one embodiment of the present invention, a nanocomposite comprises nanoparticles, for example, nano-metals, combined with at least one polymer fabricated by a monomer of, for example, a vinyl ester, for particle stabilization without any additional surfactant or coupling agent. In one particular embodiment, the nano-metal comprises iron, although other nanomaterials are contemplated for effective manufacture of a nanocomposite. As with other embodiments with other polymers, the vinyl ester monomer serves as a coupling agent with one side covalently bound onto the nanoparticle surface by a displacement reaction and the other end copolymerized with non-bound vinyl ester resin monomers to form a robust unity. The addition of iron nanoparticles favors the nanocomposite fabrication with a lower initial curing temperature. Vinyl ester resin in the nanocomposites becomes thermally stable as compared to the pure vinyl ester resin. An enhanced mechanical property is observed due to the uniform particle dispersion and the introduced interfacial covalent bondage. The iron nanoparticles become magnetically harder (with a larger coercivity) after dispersion in the vinyl ester resin matrix.
It is contemplated that nanocomposites of the present invention would comprises metal such as chromium, manganese, iron, cobalt, nickel, palladium, silver, platinum, copper, zinc, silver, gold, or lanthanum, although other metals may be suitable for certain applications useful for nanocomposites. It is further contemplated that the nano-metal particles comprise pure metals, alloys of metal particles, or oxides of metals that may have a metal core-oxide shell structure. An embodiment of an inventive nanocomposite herein could include a plurality of different nano-metal particles or alloys or oxides thereof.
One embodiment of the inventive nanocomposite was made and is set forth as an example of nanocomposites contemplated as part of the present invention. The polymeric matrix used was a vinyl ester resin, Derakane momentum 411-350 (manufactured by the Dow Chemical Company), which is a mixture of 55 wt % vinyl ester with an average molecule weight of 970 g/mole and 45 wt % styrene monomers. Styrene with only one unsaturated carbon-carbon double bond provides linear chain extension. Vinyl-ester monomers with two reactive vinyl end groups enable the cross-linking for network formation. The liquid resin has a density of 1.045 g/cm 3 and a viscosity of 350 centipoise (cps) at room temperature. Trigonox 239-A (curing catalyst or initiator, organic peroxide, liquid) was purchased from Akzo Nobel Chemicals. Cobalt naphthenate (CoNap, OM Group, Inc.) was used as a catalyst promoter (accelerator) to decompose the catalyst at room temperature. Iron nanoparticles made by QuantumSphere, Inc. of Santa Ana, Calif., with an average diameter of 20 nm and a specific surface area of 35-55 m 2 /g (BET) were produced and transported in the inert gas to prevent the oxidation. The active nanoparticles were used as nanofillers for the nanocomposite fabrication and also served as a metal precursor for the displacement between the monomers and the metals.
In one embodiment of the inventive method described herein, a specific amount of iron nanoparticles with an average size of 20 nm (provided by QuantumSphere Inc.) and the nitrogen degassed vinyl ester resin (30 g) were transferred into a 2-neck flask. The sealed flask was ultrasonically stirred for about 2 hours to completely wet the nanoparticles by the resin. The suspended solution was further stirred by hand and ultrasonically for another 2 hours until uniform dispersion is obtained. A mixture of the nitrogen degassed catalyst (2.0 wt %, Trigonox 239-A, organic peroxide, Akzo Nobel Chemicals) and promoter (0.3 wt %, cobalt naphthenate, OM Group, Inc.) was introduced quickly. The final solution was poured into a silicone mold for room temperature curing. All the reactants were added in an ultrahigh purity nitrogen protection condition, and the iron nanoparticles were handled in a fume hood due to high risk of fire and respiratory health issues. The optimum curing condition was investigated by a differential scanning calorimetry (DSC) with a heating rate of 20° C./min and a nitrogen flow rate of 10 cm 3 /min (ccpm). The reaction enthalpy (J/g) and residual heat of reaction were measured from the area under the DSC peaks.
Nanocomposites with different particle loadings were fabricated based on the functionality of the vinyl ester resin monomers and the reactivity of the metal nanoparticles. Weight percentage of nanoparticles in the nanocomposites and thermal stability of the nanocomposites were determined by the thermogravimetric analysis (TGA, PerkinElmer) with an argon flow rate of 50 ccpm and a heating rate of 10° C./min. The dispersion quality of the nanoparticles in the vinyl-ester resin matrix was investigated by scanning electron microscopy (SEM) on the polished nanocomposite cross-sectional area. The SEM samples were carefully prepared as follows. The cured composite samples were polished with a 4000-grit sand paper and a following 50 nm alumina nanoparticle aqueous solution polishing to achieve a smooth surface, then washed with DI water, and followed by sputter coating a 3 nm gold. The fracture surface of the nanocomposites after the tensile test was sputter coated with a 3 nm gold studied for SEM investigation.
An x-ray photoelectron spectroscopy (XPS) was utilized to investigate the nanocomposite formation mechanisms. XPS was conducted on a Kratos Axis Ultra XPS system using a monochromatic Al Kα source for irradiation. The sample was prepared by allowing complete reaction between the nanoparticles and vinyl ester resin monomers under ultrasonication without curing, then washing with excessive anhydrous tetrahydrofuran to remove excessive resin.
The mechanical properties were evaluated by tensile tests following the American Society for Testing and Materials standard (ASTM, 2005, standard D 1708-02a). An Instron 4411 with Series IX software testing machine was used to measure the tensile strength and Young's modulus. The dog-bone shaped specimens were prepared as described in the nanocomposite fabrication section. The specimen surfaces were smoothed with an abrasive sand paper (1000 grit). A crosshead speed of 15 mm/min was used and strain (mm/mm) was calculated by dividing the crosshead displacement (mm) by the gage length (mm). The magnetic properties were investigated in a 9-Tesla Physical Properties Measurement System (PPMS) by Quantum Design.
The iron nanoparticles were observed to have a significant effect on the curing process as investigated by DSC. The initial and peak exothermal curing temperatures were substantially decreased after the incorporation of nanoparticles in the liquid resin. The released reaction heat (based on the neat resin) decreased with the increase of the particle loading as marked in FIG. 1 . The lower initial exothermal curing temperature indicates that the addition of iron nanoparticles favors a lower temperature curing.
The DSC study on the 24-hour room temperature cured nanocomposites showed a similar 75% polymerization for composites with two different loadings. However, a lower curing temperature was observed in composites with a higher particle loading, shown in FIG. 2 . As compared to the lower initial curing temperature in the liquid composite samples, the higher initial curing temperature in the composites after 24-hour room-temperature curing is due to larger molecule chains which require more energy for further polymerization. In contrast to the lower reaction heat in the liquid nanocomposites with higher particle loading, the room temperature cured nanocomposites with higher particle loading have higher reaction heat. This is due to more monomers surrounding the particle surface with a less molecular mobility for polymerization.
FIG. 3 shows the thermo-gravimetric analysis (TGA) curves of the room temperature cured vinyl ester resin nanocomposites reinforced with different particle loadings. Vinyl ester resin in the 24-hour room-temperature cured nanocomposites was observed to be stable at temperatures lower than 300° C. and decompose at temperatures higher than 300° C. The slight weight loss in the range of 100° C. to 300° C. in the composites with low particle loadings was due to the monomer evaporation.
A fully cured nanocomposite with a 100% curing extent was deduced after post cure at 100° C. for 2 hours with an observed straight line in the DSC curves (not shown here). The thermal stability of the fully cured nanocomposite was investigated by thermo-gravimetric analysis (TGA). FIG. 4 shows the TGA curves of the fully-cured nanocomposites with different particle loadings. The fabricated polymer nanocomposites can resist to higher temperatures above 300° C. or even higher with the increase of the particle loading. Iron nanoparticles were reported to serve as a catalyst for carbon nanotube/nanofiber formation and may decrease the thermal stability of the nanocomposites. However, the enhanced thermal stability is due to the following synergistic effects. The nanoparticles lower the mobility of the polymer chains which were chemically bounded onto the nanoparticle surface. The bounded polymer, on the other hand, inhibits the active component of elemental iron to catalyze the polymer by forming an iron-vinyl ester complex. The mechanism of the reaction was investigated by X-ray photoelectron spectroscopy (XPS).
The tensile mechanical properties were measured. The Young's Modulus and tensile strength increased 170% and 20%, respectively in the 35 wt % nanocomposite. However, the tensile strength decreased in the 50 wt % nanocomposite because of the noticeable voids.
The particle distribution within the cured vinyl ester resin matrix was characterized by a field emission scanning electron microscope (SEM). FIG. 5( a ) shows the typical SEM micrograph of the cross-sectional area of the nanocomposite with a particle loading of 35 wt %. The particles show different sizes in the SEM micrographs. This is due to the particles embedding in different depth in the vinyl ester resin matrix. However, no particle pull-out (i.e., voids) in the samples after polishing was observed indicating a strong chemical bondage between the nanoparticles and the vinyl ester resin matrix.
FIG. 5( b ) shows the SEM micrographs of the fracture surface after the tensile test. A rougher fracture surface with many openings was observed in the nanocomposites as compared to the fracture surface characterized by larger smooth areas, ribbons and fracture steps observed in the cured pure vinyl ester resin. This micro-rough structure is attributed to the matrix shear yielding or local polymer deformation between the nanoparticles rather than the intra-particle propagating cracks due to the difficulty in breaking the harder iron nanoparticles. No void/holes arising from the possible peeling off the nanoparticles from the polymer matrix were observed in the high-resolution SEM micrograph as shown in the inset of FIG. 5( b ), which is similar to the polished cross-sectional composite sample and indicates a strong chemical interaction between the nanoparticles and vinyl ester resin matrix. The strong interfacial interactions between the nanoparticles and the vinyl ester resin matrix thus have an important effect on the effective transfer of the local stress. The extremely higher specific surface area inherent with the nanoscale particles as compared to the bulk/micron particles together with the strong interfacial chemical bondage between the polymer matrix and the reinforcing nanoparticles effectively facilitate the local stress transfer from the polymer matrix to the tougher metal nanoparticles, which results in a much higher tensile strength as compared with the cured pure vinyl ester resin.
FIG. 6 shows the room-temperature magnetic hysteresis loop of the as prepared vinyl ester monomer stabilized iron nanoparticles and the iron nanoparticles reinforced vinyl ester resin nanocomposites with different particle loading. The monomer stabilized iron nanoparticles were prepared by displacement reaction between iron nanoparticles and vinyl ester resin in ultrasonication and nitrogen protection conditions, washing with tetrahydrofuran and drying in a vacuum oven.
The magnetization of the monomer stabilized iron nanoparticles and the fully cured vinyl ester resin nanocomposite does not saturate at higher field as shown in FIG. 6 . Saturation magnetization was determined by the extrapolated saturation magnetization obtained from the intercept of the magnetization versus H-1 at high field. The calculated Ms was 30.5 emu/g, 52.5 emu/g, and 73.0 emu/g for the vinyl ester resin nanocomposites with a particle loading of 15 wt %, 25 wt %, and 35 wt %, respectively. Ms based on the pure iron nanoparticles was about 203 emu/g, 210 emu/g, and 209 emu/g for nanocomposites with a particle loading of 15 wt %, 25 wt %, and 35 wt %, respectively. All of these values are a little lower than that of the bulk iron (218 emu/g), C. Brosseau and P. Talbot, J. Appl. Phys., 2005, 97, 104325-1/11, which is due to the loss of the active magnetic iron on the nanoparticle surface arising from the iron oxidation either by the displacement or exposure to air during the composite fabrication.
The iron nanoparticle is reported to have a superparamagnetic zerocoercivity region of 10 nm and a critical size of 100 nm with a maximum coercivity. The coercivity decreases to that of the bulk iron when the nanoparticles become agglomerate with size of microscale. The observed larger coercivity in the nanoparticles after dispersed in the polymer matrix further indicates a fairly uniform dispersion of nanoparticles in the polymer matrix, i.e., the nanoparticles are stabilized by the vinyl ester monomers without agglomeration. Gas bubbles were observed during the particle dispersion in the vinyl ester resin in the air-free nitrogen condition. This is due to the hydrogen generation arising from the displacement reaction between reactive metallic iron nanoparticles and vinyl ester monomers. The nature of the interaction between the nanoparticles and the vinyl ester monomers was investigated by XPS investigation and the XPS samples were prepared carefully as described in Experimental section. FIG. 7 shows the high resolution carbon 1s XPS spectra with all the fitting curves representing different functional groups. The peaks at 284.6 eV, 285.0 eV, 286.6 eV, and 288.6 eV represent C—C and/or C—H, C—C and/or C—H, C—O, and C═O bonds, respectively. These characteristic peaks arise from the vinyl ester resin and thus indicates the presence of vinyl ester resin on the nanoparticle surface. Iron 2p3/2 high resolution XPS spectrum verified partial oxidation of the iron nanoparticle surface arising from the displacement of the vinyl ester resin on the nanoparticle surface.
The nanocomposite formation mechanisms are shown in Scheme 1, where an example of vinyl ester stabilization of iron nanoparticles is shown, with “OR” representing the hydroxyl group in vinyl ester. The active metallic iron nanoparticles react with the hydroxyl functional groups of the vinyl ester monomers and release hydrogen. The vinyl ester monomer serves as a surfactant with one side chemically bound onto the nanoparticle surface. The other side promotes the dispersion of the nanoparticles in the monomer solution. The subsequent addition of the catalyst and promoter serves as a free radical to initiate the monomer polymerization for crosslinkage formation. The carbon-carbon double bonds of the vinyl ester monomers bound onto the nanoparticles also copolymerize with the unbound monomers (styrene for polymer chain growth or vinyl ester monomers for polymer cross-linking growth) to form a robust nanocomposite. The strong chemical bondage between the nanoparticles and the vinyl ester matrix enhances the mechanical properties. The linked vinyl ester serves as a spacer to separate the nanoparticles leading to an observed larger coercivity. The crosslinked vinyl ester resin matrix provides the protection for the iron nanoparticles from further oxidation and dissolution in acidic environments.
FIG. 8 shows the room-temperature hysteresis loops of the as-prepared and heat-treated vinyl ester monomer stabilized iron nanoparticles. The samples were prepared through a displacement reaction between iron nanoparticles and the vinyl ester resin activated through sonication in a nitrogen environment. The mixture was washed with tetrahydrofuran and dried in a vacuum oven at room temperature. As compared to the reported coercive force (coercivity, Hc) of 5 Oe for the bare superparamagnetic iron nanoparticles, coercivity is observed to increase to 153 Oe after stabilization with the vinyl ester monomers. This is due to the interparticle dipolar interaction within the nanocomposite achieved with a uniform dispersion of single-domain nanoparticles, consistent with a particle loading dependent coercivity in the nanoparticle assembly. Little coercivity difference is observed in the samples after annealing, however the saturation magnetization (Ms, 76 emu/g) of the as-prepared nanocomposites increases to 109 emu/g after annealing due to the decomposition of vinyl ester monomers. The lower saturation magnetization in both composite samples indicates that the displacement reaction has caused the majority of the iron atoms on the nanoparticle surface to become a nonmagnetic salt.
The as-prepared vinyl ester monomer stabilized Fe nanoparticles exhibit lower electric resistivity as compared to the one after heat treatment as shown in FIG. 9( a ). The resistivity of the monomer stabilized iron nanoparticles increases slowly with decreasing temperature in the range of room-temperature to 100° C. and then remains constant at temperatures lower than 100° C. However, the nanocomposites become less conductive after the heat treatment. The resistivity increases slowly from room-temperature to 100° C. and suddenly increases beyond the equipment limitation. The linear relation between logarithmic resistivity and the square root of temperature T-1/2 shown in FIG. 2( b ) indicates a tunneling conductive mechanism for the heat-treated vinyl ester monomer stabilized nanoparticles. Both non-metallic behaviors were observed in the as-prepared and heat-treated monomer stabilized iron nanoparticle samples, indicating that vinyl ester monomers and the subsequently carbonized vinyl ester have effectively protected Fe nanoparticles from oxidation. There are three regions for the as-prepared vinyl ester monomer stabilized nanoparticles as shown in FIG. 9( b ). This behavior could be due to the thermal shrinkage/expansion of the stabilized polymer chain with a change of the temperature. MR (%) in the composite is defined as:
MR ( % ) = R ( H ) - R ( 0 ) R ( 0 ) × 100
where R(H) and R(0) are the resistivity at a field of H and zero, respectively. A room temperature GMR of 1.7% is observed in the heat-treated vinyl ester monomer stabilized iron nanoparticles as shown in inset of FIG. 2( b ). However, only 0.9% MR is observed in the as-prepared vinyl ester monomer stabilized iron nanoparticles.
The particle distribution within the cured vinyl ester resin matrix before the heat treatment was characterized by a scanning electron microscope (SEM). The polymer nanocomposite samples with a particle loading of 40 wt % were prepared by polishing the cured vinyl ester resin samples with 4000 grit sandpaper. The inset of FIG. 10( a ) shows the typical SEM images of the cross-section of the nanocomposite. The uniform particle dispersion within the polymer matrix indicates that vinyl ester resin has effectively protected the iron nanoparticles from agglomeration. Further X-ray photoelectron spectroscopy (XPS) investigation indicates a strong particle-polymer interaction through the displacement reaction between the reactive nanoparticles and the vinyl ester resin monomers.
A large shrinkage is observed in the nanocomposites after a two-hour annealing at 450° C. There is no further polymer residue observed after the heat treatment as evidenced by FT-IR investigation. These results indicate a complete decomposition of the cured vinyl ester resin in the polymer nanocomposites. FIG. 10( b ) shows the TEM bright field microstructures of the nanocomposite (40 wt %) after heat treatment at 450° C. for 2 h. The left inset of FIG. 10( b ) shows the selected area electron diffraction (SAED) patterns of the annealed polymer nanocomposites. The inner ring of the SAED patterns with a d-spacing of 0.34 nm clearly indicates the formation of graphite carbon. The obvious core-shell structure arises from the atomic number difference between iron and carbon. The right inset of FIG. 10( b ) shows the high-resolution TEM microstructure of the annealed polymer nanocomposites. The observed clear lattice fringes indicate the formation of highly crystalline nanoparticles and the calculated lattice distance of 0.205 nm corresponds to Fe.
FIG. 10( a ) shows the room-temperature hysteresis loops of the vinyl ester resin nanocomposites with a particle loading of 15 and 40 wt % before and after heat-treatment, respectively. Larger coercivity (230 Oe) is observed after the Fe nanoparticles are dispersed in the vinyl ester resin nanocomposites, as compared to those of the bare superparamagnetic iron nanoparticles and vinyl ester monomer stabilized iron nanoparticles. This indicates a weak interparticle dipolar interaction after the nanoparticles are dispersed into the polymer matrix. However, Hc is much lower than those (685 and 900 Oe for 65 and 35 wt % loading, respectively) of the iron/polyurethane system. The saturation magnetizations (Ms) of the nanocomposites are 34 and 72 emu/g for the particle loadings of 15 and 40 wt %, corresponding to 213 emu/g and 183 emu/g for the nanoparticles, respectively. Ms in the vinyl ester resin system is much larger than that in the polyurethane system, which is due to the particle oxidation in the polyurethane nanocomposite fabrication process and particle-polymer surface interaction effects. The observed smaller Hc after the heat-treatment is due to the decreased interparticle distance concomitant with a stronger dipolar interparticle interaction.
No electric conductivity is detected in the vinyl ester resin nanocomposites reinforced with the iron nanoparticles, even at 40 wt % loading, indicating the particle loading is still lower than the percolation threshold. The conductivity improves considerably after the heat treatment. FIG. 11 shows the temperature dependent resistivity of the vinyl ester resin nanocomposites after heat treatment at 450° C. for 2 hours. The resistivity increases significantly with decreasing temperature, characteristic of a non-metallic behavior. In view of the high conductivity of iron, the high resistance observed in the 450° C. heat treated specimen is due to the poor conductivity of the carbon matrix. With decreasing temperature, the resistivity increases much faster in the heat-treated 15 wt % nanocomposites than in the heat-treated 40 wt % nanocomposites. This is obviously attributed to the dominating less-conductive carbon matrix in the 15 wt % nanocomposites, as compared to the dominating more-conductive iron in 40 wt % nanocomposites. The observed linear relationship between the logarithmic resistivity and the square root of temperature T-1/2 shown in FIG. 11 indicates an interparticle tunneling/hopping conduction mechanism, which is different from the observed metallic conduction as observed in the granular Co—Au coreshell nanoparticles. The decreased carbon content in the nanocomposite with an initial particle loading of 40 wt % favors electron spin hopping from one particle to another, thus it has a lower resistivity as compared to that of the nanocomposites with an initial particle loading of 15 wt %.
The particle loading was observed to have a dramatic effect on the MR performance of the annealed nanocomposites as shown in FIG. 12 . A room temperature MR of 8.3% is observed in the heat-treated nanocomposite with an initial particle loading of 15 wt %, whereas the heat-treated nanocomposites with an initial particle loading of 20 and 40 wt % show a room-temperature MR of 6.8% and 6.0%, respectively. All of these GMR values are observed at a fairly high field of 90 kOe. Compared to multilayered GMR materials, a high magnetic field is required to saturate the MR, which is characteristic of the tunneling conduction mechanism. However, a 2.0% MR observed at 4.5 kOe still indicates that the GMR in these nanocomposites could be used for biological targeting applications. The particle loading dependent MR is attributed to the interparticle distance. In addition, the spacer materials (vinyl ester resin and carbonized vinyl ester resin) play a role in the MR property. The observed field dependent MR hysteresis loops ( FIG. 12 ) in the nanocomposite with high particle loadings are also due to the decreased interparticle distance together with a strong interparticle dipolar interaction.
The foregoing description is that of preferred embodiments having certain features, aspects, and advantages. Various changes and modifications also may be made to the above-described embodiments without departing from the spirit and scope of the inventions. For example, numerous different nano-sized particles may be used to create a nanocomposite according to the present invention, depending upon the desired application. In addition, numerous different polymers may be used to create a nanocomposite according to the present invention, depending upon the desired application.
Although the description above contains many details, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Therefore, it will be appreciated that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural, chemical, and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112, sixth paragraph, unless the element is expressly recited using the phrase “means for.” | An improved method is provided to prepare reinforced resin nanocomposites without the need of surfactants or coupling agents. The present invention comprises the use of monomers for improving the dispersion of nano-sized materials and enhancing the particle/matrix interaction. One comprises mixing a plurality of nanoparticles with a monomer resin to form a mixture, blending a catalyst and a promoter with the mixture, and curing the blended mixture to form a polymerized nanocomposite. The monomers, which serve to stabilize the nanoparticles, are covalently bound onto the nanoparticle surface and copolymerize with non-bound monomers after introduction of a catalyst and a promoter that initiate polymerization. Without any additional surfactant or coupling agent, the resin is chemically bound onto the nanoparticle surface and protects the iron nanoparticles from agglomeration and oxidation. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation application of U.S. application Ser. No. 10/906,486 filed Feb. 22, 2005 and presently pending.
[0002] The present invention relates generally to a wear-resistant weld overlay applied to a substrate and to a process for producing the resulting hardfaced structure. More specifically, the present invention relates to a carbide metal matrix composite weld overlay which offers high wear resistance with reduced weight.
BACKGROUND OF THE INVENTION
[0003] The invention has been developed in connection with hardfacing of metal components used in mining and processing of oil sand and it will be described herein in connection with that environment. However, it is contemplated that the invention may find application in other fields of use as well.
[0004] Oil sand is mined, trucked, slurried, conveyed in a pipeline and processed, using various equipment and vessels, all with the objective of recovering contained bitumen (a form of heavy viscous oil). Both the dry, as-mined oil sand and the slurry obtained by mixing the oil sand with heated water are particularly abrasive and erosive.
[0005] The industry has, therefore, for many years, conducted research and introduced improvements with respect to hardfacing the steel and other metal components that come in contact with the oil sand and slurry, to enable them to better withstand the wear.
[0006] One example of the progress achieved in this regard has to do with screens used to remove oversize ore from the slurry. Initially these screens were formed of carbon steel with no overlay. Thus, the life of such a screen was relatively short, in the order of 500,000 tons of slurry treated. To improve their life, the screens were then hardfaced with a chrome carbide weld overlay. The life of the screens were thereby extended to about 5,000,000 tons of slurry treated. Following this, tungsten carbide (WC) powder, the hard phase, was applied together with a powder matrix of Ni—Cr—B—Si, and the screens were hardfaced using an oxy-acetylene torch. The life of the screens were thereby extended to about 20,000,000 tons of slurry treated.
[0007] These achievements were hard won through years of experimentation. They involved successfully marrying selected overlay materials with selected welding techniques.
[0008] The current hardfacing system, involving WC, has problems associated with it. The WC has a relatively high density, in the order of 15.8-17.2 g/cm 3 , depending on the type of tungsten carbide used. The matrix (Ni—Cr—B—Si) has a density of about 8.9 g/cm 3 . As a result of the high densities and the difference in densities between the WC and Ni—Cr—B—Si matrix, the WC particles tended to sink in the weld pool and segregate. This is undesirable as one wants to maintain as even a distribution of the hard phase in the overlay as one can manage, to ensure uniform wear performance.
[0009] In addition, WC is relatively expensive. Further, the WC overlay is relatively heavy. If, for example a truck box is lined with the WC overlay, the load capacity of the truck is significantly diminished due to the added weight of the overlay. Finally, there is a narrow window of welding parameters that can be used to overlay with such a matrix.
[0010] It will therefore be appreciated that there has long existed a need for an overlay system that is relatively less expensive, relatively less likely to be characterized by hard phase segregation, easy to weld and amenable for preferred use with a lightweight metal substrate to produce a lightweight structure.
SUMMARY OF THE INVENTION
[0011] In accordance with the invention, a powder form of a hard phase component, selected from the group consisting of boron carbide, silicon carbide and a mixture of boron carbide and silicon carbide, is combined with an aluminum alloy matrix powder and applied to a metal substrate using plasma transferred arc (“PTA”) welding to produce a hardfaced structure having a wear-resisting carbide metal matrix composite overlay.
[0012] The metal substrate can be any metal structure where wear resistance is desirable. The metal substrate can be comprised of any metal or combination of metals, for example, aluminum, aluminum alloy, steel, carbon steel and the like.
[0013] There are many commercial aluminum alloy matrix powders available, having alloying constituents such as zinc, magnesium, silicon, zirconium, titanium and the like, which can be used in accordance with the present invention.
[0014] In one embodiment the invention is directed to a hardfaced structure comprising: a metal substrate; and a weld overlay fused to the substrate, the overlay comprising an aluminum-containing metal matrix composite securing hard phase particles, selected from the group consisting of boron carbide, silicon carbide and a mixture of boron carbide and silicon carbide, distributed therein.
[0015] In a preferred embodiment, boron carbide powder is combined with an aluminum-silicon alloy matrix powder and applied by PTA welding to an aluminum or aluminum alloy substrate to produce a lightweight hardfaced structure. Alternatively the powders can be applied by PTA welding to a steel substrate, such as a slurry screen, to hardface the steel substrate. In a further preferred embodiment, the aluminum-silicon alloy matrix powder comprises aluminum and 12% by weight silicon, which is a eutectic mixture.
[0016] It is understood by those skilled in the art that the upper particle size limit of the hard phase particles is determined by the plasma torch design for the powder feed of the PTA welding equipment. It is further understood that the lower size limit is determined based on the survivability (decomposition) of the smaller hard particles as the particles are transferred through the welding arc.
[0017] Thus, in a preferred embodiment, the hard phase particles have a mean particulate size greater than about 20 microns to about 1000 microns. In a further preferred embodiment, the hard phase particles have a particulate size ranging between about 53 microns and about 210 microns, with a mean or average size of approximately 100 microns.
[0018] In another embodiment, the invention is directed to a process for hardfacing a metal substrate comprising: feeding a hard phase powder, selected from the group consisting of boron carbide, silicon carbide and a mixture of boron carbide and silicon carbide, and an aluminum alloy metal matrix powder to an operative plasma transferred arc welding torch; and welding to form a carbide metal matrix composite overlay fused to a metal substrate.
[0019] The metal substrate produced by the hardfacing process herein exhibits increased wear resistance without a significant increase in the overall weight of the metal substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a schematic representation of the process for hardfacing a metal substrate according to an embodiment of the invention.
[0021] FIGS. 2 a , 2 b , 2 c and 2 d are photomicrographs of two of the Al—Si—B 4 C weld overlays of the invention.
[0022] FIG. 3 is a photomicrograph of a 70 wt. % B 4 C in 30 wt. % Al—Si weld overlay of the invention.
[0023] FIG. 4 is a schematic of the slurry jet erosion test rig used to measure wear resistance.
[0024] FIG. 5 illustrates a volume loss (mm 3 ) versus impingement angle (degree) graph for welded structures of the invention having been hardfaced with various Al—Si—B 4 C overlays.
[0025] FIGS. 6( a ), 6 ( b ) and 6 ( c ) are scanning electron micrographs showing the erosion/wear of a 30% Al—Si-70% B 4 C overlay at 20°, 45° and 90° impingement angles, respectively
[0026] FIGS. 7( a ), 7 ( b ) and 7 ( c ) are scanning electron micrographs showing the erosion/wear of a 35% Ni—Cr—B-65% WC overlay at 20°, 45° and 90° impingement angles, respectively.
[0027] FIG. 8 is a bar graph showing the volume loss (mm 3 ) using ASTM G 65 testing procedure for welded structures of the invention having been hardfaced with various Al—Si—B 4 C/SiC overlays.
[0028] FIGS. 9( a ) and 9 ( b ) are scanning electron micrographs at 35 times and 150 times magnification, respectively, of a ASTM G 65 wear scar for a 30% Al—Si-70% B 4 C overlay.
[0029] FIG. 10 illustrates a volume loss (mm 3 ) versus impingement angle (degree) graph for welded structures of the invention having been hardfaced with a weld overlay comprising 40 wt. % Al-12 wt. % Si+30 wt. % B 4 C+30 wt. % SiC.
[0030] FIG. 11 is a photomicrograph of a weld overlay comprising 40 wt. % Al-12 wt. % Si+30 wt. % B 4 C+30 wt. % SiC.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] The invention is exemplified by the following description and examples.
Example I
[0032] With reference to FIG. 1 , a plasma transferred arc (“PTA”) welding machine 3 comprising electrode 5 connected to the negative terminal of a power supply (not shown) is provided. The hardfacing substrate, aluminum substrate 2 , is connected to the positive terminal of the power supply. A primary arc of inert gas 7 is established between electrode 5 and aluminum substrate 2 to create a plasma column 6 .
[0033] A powder of hardfacing material 8 , comprising a mixture of boron carbide powder (hard phase particle) and aluminum-silicon alloy powder (metal matrix), is introduced into passage 9 , typically by use of an inert gas as a carrier. While in the plasma column 6 , at least one component of the hardfacing material 8 is melted by the plasma column 6 and a weld 1 of hardfacing material is applied to aluminum substrate 2 to form welded structure 4 . This process was repeated with a number of samples to yield welded structures for examination.
[0034] More particularly, the process was carried out as follows:
boron carbide (B 4 C) powder (−70/+270 mesh size) was obtained from ElectroAbrasive, Inc.; the powder had a density of 2.54 g/cm 3 ; aluminum—12 wt. % silicon (Al—Si) alloy powder (−140/+325 mesh size) was obtained from Eutectic Canada Inc.; the powder had a density of 3.21 g/cm 3 ; the B 4 C and Al—Si powders were blended in the following range of proportions: 0% by wt. B 4 C and 100% by wt. Al—Si to 70% by wt. B 4 C and 30% by wt. Al—Si; the 12″ long×3″ wide×1″ thick 6061 T6 aluminum substrate 2 was pre-heated to 100° C. in an oven prior to welding to assist in subsequent fusion; the mixture of powders was fed in argon carrier gas at a rate of 6 Λ/min through the feed port of a Eutectic Gap 375 PTA welding machine 3 and torch; samples were prepared in the following welding parameter ranges: current: 100-120 Amps; voltage: 27-30 V; travel speed 3.875-4.625 inches per minute, 1 inch weave size; powder feed rate: 11.5 g/min; plasma gas: 6 Λ/min; shielding gas: 25 Λ/min; and the powder feed was deposited on top of the aluminum substrate 2 creating a weld overlay several mm thick.
[0042] FIGS. 2 a and 2 c , and FIGS. 2 b and 2 d are photomicrographs at 37.5 times magnification and 375 times magnification, respectively, of two of the Al—Si—B 4 C overlays so produced. The overlay shown in FIGS. 2 a and 2 b was produced from a powder mixture consisting of 10 wt. % B 4 C in Al—Si. The overlay shown in FIGS. 2 c and 2 d was produced from a powder mixture consisting of 20 wt. % B 4 C in Al—Si.
[0043] FIGS. 2 a and 2 c demonstrate that the boron carbide particles are relatively uniformly dispersed throughout the aluminum-silicon metal matrix in each overlay. Further, it can be seen in FIGS. 2 b and 2 d that the boron carbide particles are highly angular, indicating minimal decomposition of these particles during the PTA welding process, under the welding parameters that were used.
[0044] FIG. 3 is a photomicrograph showing an acceptable distribution of carbide particles when the PTA welding parameters described above were used to produce a welded sample having good wear resistance. The powder mixture used was 70 wt. % B 4 C in 30 wt. % Al—Si. It can be seen in FIG. 3 that the boron carbide particles are uniformly dispersed and closely packed together, thus providing close to maximum wear resistance. Again, high angularity of the particles indicates minimal decomposition.
[0045] Welded structures 4 of Example I were subjected to sectioning, mounting and polishing for metallographic inspection and surface ground for dry sand rubber wheel wear resistance testing in accordance with the ASTM G 65 procedure. Slurry erosion tests were also performed on these samples at the National Research Council-Innovation Centre in Vancouver, Canada.
[0046] The ASTM G 65 Test Method for Measuring Abrasion Using the Dry Sand/Rubber Wheel Apparatus Low Stress is well known in the art and is described more fully in the standard. However, a modified Procedure A test was performed to more accurately rank the metal matrix composite materials of the invention. The modified test involved performing two Procedure A tests in the same wear scar. This was done because the first G 65 test essentially removes the matrix material resulting in an initially high wear rate. Once the matrix is removed, however, the hard carbides provide the wear resistance. Thus, the second G 65 test in the same wear scar more accurately represents the actual wear resistance of the metal matrix composite overlay.
[0047] The slurry erosion test was performed to corroborate the results obtained with the G 65 test. The slurry erosion test can be best described with reference to slurry jet erosion test rig 10 shown in FIG. 4 . The eroding material used in the slurry test is an 8% by weight AFS 50-70 Ottawa silica sand in a water slurry. Air 11 is supplied via electronic valve 12 to slurry pump 14 . Computer 16 controls air pressure.
[0048] Silica sand slurry 30 is housed in slurry tank 24 and fed to slurry pump 14 via slurry line 32 . Flow meter 18 measures the rate in which the silica sand slurry is feed through nozzle 20 , said nozzle 20 having a nozzle orifice diameter of 5 mm. Nozzle 20 is directed at hardfaced sample structure 22 , which preferably is located approximately 120 mm away from it.
[0049] The impingement angle of the slurry jet onto sample structure 22 can be adjusted as required. As a standard, testing is performed at 20°, 45° and 90° impingement angles. Spent silica sand slurry 30 is collected in slurry tank 24 and recycled through slurry pump 14 for repeated use. Slurry by-pass valve 26 allows silica sand slurry 30 to by-pass nozzle 20 .
[0050] Each hardfaced sample structure 22 is then measured for volume loss (mm 3 ). Volume loss is directly measured by laser profilometry.
[0051] FIG. 5 shows the slurry erosion test results for four sample structures having been hardfaced with four different overlays comprising 90% Al—Si—10% B 4 C, 72% Al—Si-28% B 4 C, 40% Al—Si-60% B 4 C and 30% Al—Si-70% B 4 C. The volume loss of each sample structure was measured and compared to a sample structure having been hardfaced with a 35% Ni—Cr—B-65% WC overlay. The results in FIG. 5 demonstrate that erosion or wear resistance (as demonstrated by a decrease in volume loss (mm 3 ) of the sample structures) increases significantly with the increase in carbide particles added to the Al—Si metal matrix. The sample structure comprising the 30% Al—Si-70% B 4 C overlay was shown to have the closest wear resistance to 35% Ni—Cr—B-65% WC.
[0052] FIGS. 6( a ), 6 ( b ) and 6 ( c ) are scanning electron micrographs showing the erosion/wear of the 30% Al—Si-70% B 4 C overlay at 20°, 45° and 90° impingement angles, respectively. For comparison, FIGS. 7( a ), 7 ( b ) and 7 ( c ) are scanning electron micrographs showing the erosion/wear of the 35% Ni—Cr—B-65% WC overlay at 20°, 45° and 90° impingement angles, respectively. It can be seen that the erosion/wear scars look similar in appearance for both the 30% Al—Si-70% B 4 C overlay and the 35% Ni—Cr—B-65% WC overlay. The boron carbide samples look slightly more polished but there was no significant evidence of particle fracture in the locations that were observed.
[0053] FIG. 8 is a bar graph showing the ASTM G 65 results for sample structures comprising various Al—Si—B 4 C weld overlays of the invention. The results in FIG. 8 also demonstrated that that erosion or wear resistance (as demonstrated by a decrease in volume loss (mm 3 ) of the sample structures) increased significantly with the increase in carbide particles added to the Al—Si metal matrix. The sample structure comprising the 27 % Al—Si-73% B 4 C weld overlay was shown to have the closest wear resistance to 35% Ni—Cr—B-65% WC.
[0054] FIGS. 9( a ) and 9 ( b ) are scanning electron micrographs at 35 times and 150 times magnification, respectively, of a ASTM G 65 wear scar for a 30% Al—Si-70% B 4 C overlay. The wear scar was similar to that of 35% Ni—Cr—B-65% WC (not shown).
Discussion Relative to Example I
[0055] A reasonably wide range of welding parameters produced results similar to the foregoing. This is in contrast to the very tight controls on welding parameters one requires when PTA welding WC—Ni—Cr—B—Si overlays to produce acceptable carbide distribution throughout the weld. The welding parameters are controlled by WC decomposition and poor distribution (due to slower cooling rates) at higher welding heat inputs and lack of fusion at low heat inputs.
[0056] The poor distribution of WC in Ni—Cr—B—Si metal matrix material is partially due to the significantly different densities of WC and WC/W 2 C (15.8-17.2 g/cm 3 ) compared to approximately 8.9 g/cm 3 for nickel alloys. In contrast, B 4 C or SiC with densities of 2.52 and 3.21 g/cm 3 , respectively, are much more compatible with aluminum which has a density of 2.7 g/cm 3 . Practically, this means that a much larger welding parameter window is possible with the present system, which allows the welder more flexibility in how welding is performed.
[0057] The matrix powder used in the experimental runs was Al-12 wt. % Si alloy, which is a eutectic composition. This material yields a low melting point (approx. 575° C.) when compared to Al-6061, which melts in the range of 582-652° C. While Al-6061 does produce acceptable uniform distribution of the carbide particles, the use of the eutectic Al-12 wt. % Si alloy ensures that the Al-12 wt. % Si alloy welds cool very rapidly, essentially going directly from a liquid to a solid. This allows for optimal uniform distribution of the carbide particles.
[0058] The low density of the combined PTA Al-12 wt. % Si—B 4 C weld overlay yields a low weight, wear-resistant material that could be used in applications where weight restrictions are of concern. As an example, power shovels and other excavating equipment used in mining applications can have literally tons of wear protection to ensure reasonable equipment life. This directly reduces the payload carrying capacity of these units. Using lightweight wear protection could not only provide an adequate level of wear protection but also increase the productivity of the equipment by potentially increasing the payload capacity of the unit.
Example II
[0059] This Example demonstrates that SiC can be substituted for some or all of the B 4 C.
[0060] The same welding parameters, equipment and procedures were used to produce weld overlays using a 40 wt. % Al-12 wt. % Si+30 wt. % B 4 C+30 wt. % SiC feed mixture as in Example I. FIG. 10 shows that this combination gave essentially the same erosion testing results as the 30 wt. % Al-12 wt. % Si+70 wt. % B 4 C combination. Additionally, the photomicrograph in FIG. 11 shows that the dark phase (SiC) and the light phase (B 4 C) carbides are very angular indicating little decomposition of the carbides during processing.
[0061] This substitution would be done in consideration of the properties required for the final weld overlay. It appears from FIG. 10 that erosion performance is acceptable for both the B 4 C and B 4 C/SiC mixture tested. However, the high silicon content of the aluminum alloy also inhibits the degradation of SiC, which begins decomposing at 1700° C. B 4 C does not decompose but sublimes at 2400° C. It should be noted that these temperatures could be reached during processing as the powder is passed through the welding torch onto the substrate. The welding arc itself can reach temperatures of over 30000° K.
Example III
[0062] The aluminum-carbide metal matrix composite overlays of the invention can be joined to most other metals either directly (as shown in Examples I and II) or indirectly by precoating the other metals or using a bi-metallic transition piece. For example, to hardface a carbon steel substrate, the overlay is deposited onto an intermediate alloy, which is placed onto the carbon steel substrate by a number of methods known to a person skilled in the art. This is often referred to in the art as “buttering” the steel with a “butter layer” such as a nickel or copper alloy.
[0063] Methods for buttering steel can be found in American Welding Society Welding Handbook, Materials and Applications-Part 1, “Aluminum and Aluminum Alloys, Joining to Other Metals”, (American Welding Society 1996), p. 97, and include the following:
1. brazing a nickel or copper based alloy onto the carbon steel surface; 2. roll bonding, cladding or explosion bonding a nickel or copper based alloy of at least ⅛″ in thickness onto the base carbon steel; and 3. Arc welding of suitable nickel or copper based metallurgy on top of a carbon steel substrate. | A powder form of a hard phase component, selected from the group consisting of boron carbide, silicon carbide and a mixture of boron carbide and silicon carbide, is combined with an aluminum alloy matrix powder and applied to a metal substrate using plasma transferred arc (“PTA”) welding to produce a hardfaced structure having a wear-resisting carbide metal matrix composite overlay. The metal substrate can be any metal structure, such as an aluminum, aluminum alloy, steel or carbon steel structure, where wear resistance is desirable. Further, a process for hardfacing a metal substrate is disclosed comprising feeding a hard phase powder, selected from the group consisting of boron carbide, silicon carbide and a mixture of boron carbide and silicon carbide, and an aluminum alloy metal matrix powder to an operative PTA welding torch and welding to form a carbide metal matrix composite overlay fused to a metal substrate. The metal substrate produced by the hardfacing process herein exhibits increased wear resistance without a significant increase in the overall weight of the metal substrate. | 8 |
FIELD OF THE INVENTION
The present invention relates to a locking fastener to prevent the loosening of a threaded fastener in a fastener joint.
BACKGROUND OF THE INVENTION
Locking washers are commonly used in fastening assemblies to prevent relative motion between the stem and fastened pieces, which may cause a nut to back off the stem, thereby loosening the fastened piece.
Vehicle wheel assemblies commonly include an axle shaft supported for rotation by a knuckle and a wheel bearing disposed between the shaft and knuckle. The assembly is commonly secured by a retaining ring. A disc for mounting a wheel for rotation with the axle shaft is then mounted on the shaft. The disc may integrate a brake rotor and hub flanges into one piece. A locking washer slides against the disc and a nut tightens the locking washer against the disc to prevent relative movement between the axle shaft and the disc, which may cause the nut to back off the axle shaft.
A variety of locking washers known in the art have been used with vehicle wheel assemblies to prevent nut loosening, including split washers and star washers. One problem with using star or split washers in vehicle wheel assemblies is that during operation of the vehicle, these washers may still be subject to movement. Any relative movement may cause the nut to back off, which in turn may cause the wheel to become detached while the vehicle is in motion.
To address these and other deficiencies associated with conventional locking washer configurations, including star or split washers, manufacturers have machined the threaded portion of the axle shaft to create a linear groove extending along its threads. The washer is provided with a spline tang extending into the groove to prevent the washer from rotating relative to the threaded shaft. A similar locking washer uses a flat portion on the inside circumference to lockingly engage a flat plane machined on the external threads. These designs prevent the nut from loosening because the washer cannot rotate around the axle shaft while being subjected to vibration, twisting, expansion, contraction, and other possible movements. However, these designs require additional machining of the threaded portion of the axle shaft. Any extra machining increases manufacturing costs and expense. Moreover, care must be taken in machining the threaded portion of the axle shaft to prevent damage to any threads.
SUMMARY OF THE INVENTION
The present invention is directed to a vehicle wheel assembly having a locking washer and axle shaft configuration that prevents rotational movement of the washer relative to the axle shaft without requiring machining of the threaded portion of the shaft.
The locking washer includes a generally flat outboard face against which the nut tightens. The inboard face of the washer includes an indented portion, which defines members that mate with torque transferring members on the axle shaft. The invention is further directed to a locking washer that has a step portion that allows the washer members to engage the torque transferring members of the axle shaft while securely locking the disc onto the axle shaft.
Further scope of applicability of the present invention will become apparent from the following detailed description, claims, and drawings. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given here below, the appended claims, and the accompanying drawings in which:
FIG. 1 is a sectional view of a wheel end assembly according to the present invention;
FIG. 2 is an exploded perspective view of the wheel end assembly shown in FIG. 1 ;
FIG. 3 is a partial sectional view taken along the line 3 — 3 shown in FIG. 1 ;
FIG. 4 is an elevational view of the locking washer viewed from axially inward of the washer;
FIG. 5 is a side sectional view of the locking washer taken along the line 5 — 5 shown in FIG. 4 ;
FIG. 6 is an elevational view similar to FIG. 4 illustrating an alternative embodiment of the locking washer; and
FIG. 7 is an exploded sectional view of the wheel and assembly shown in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
I. Construction
A wheel end assembly 10 constructed in accordance with the preferred embodiment is illustrated in FIG. 1 . Conventionally, wheel end assemblies attach a wheel to a vehicle axle 20 and transmit torque from the engine to the wheel. To this end, the wheel end assembly 10 includes an axle support assembly 30 , a disc 50 fixed to the wheel, a locking washer 60 , and a nut 90 . The axle 20 is coupled to the engine of the car through the drive train, passes outward from the center of the car, and is supported for rotation by the axle support assembly 30 . The axle support assembly 30 includes a housing or knuckle 32 that forms a cavity within which is disposed a wheel bearing unit 40 to facilitate rotation of the axle 20 relative to the knuckle 32 . The axle support assembly 30 , wheel bearing unit 40 , and disc 50 are secured to the axle 20 by the locking washer 60 and the nut 90 , as shown in FIG. 1 .
In general, inner bearing rings 44 of the wheel bearing unit 40 and the disc 50 rotate with the axle 20 to drive the vehicle wheel. While a variety of axle, bearing unit, and disc configurations may be used to provide the desired rotational coupling, the illustrated embodiment of the axle 20 includes a shaped portion 22 ( FIG. 2 ) disposable within the wheel bearing unit 40 and the disc 50 and configured to rotationally couple the disc 50 to the axle 20 . Notwithstanding the variety of configurations that may be used with the present invention, it is noted that the shaped portion 22 and a cooperating central passage 52 on the disc 50 may provide a friction fit, include cooperating splines (typically twenty-eight to thirty-six splines), or polygonal lobes to rotationally interlock the shaped portion 22 with the disc 50 . It should be appreciated that while a single shaped-section 22 is described herein, separate sections of differing configurations may be used without departing from the scope of the invention defined by the appended claims. The axle 20 and inner wheel bearing rings 44 are illustrated as being frictionally coupled, but a variety of other methods may be used. The axle 20 also includes a threaded portion 24 positioned axially outward of the shaped section 22 and having threads configured to cooperate with the internal threading on the nut 90 .
As is best shown in FIGS. 4 and 5 , the locking washer 60 includes an axially outer face 72 , an inner face 76 , a sleeve 78 , a central hole 74 sized to receive the axle 20 , and a shaped cavity 82 recessed axially from the inner face 76 and communicating with the central hole 74 to define a passage extending through said washer. The cylindrical and inwardly projecting washer sleeve 78 is disposable within a sleeve groove 62 formed in the disc 50 (FIG. 7 ). The shaped cavity 82 is partially defined by a non-cylindrical outer surface 84 having projections 83 configured to match the cross-sectional configuration of the shaped section 22 of the axle 20 . By this arrangement, the washer 60 is rotationally coupled to the axle shaft 20 , thereby preventing any rotational movement of the washer 60 relative to the axle shaft 20 . The outer face 72 may be scored or include other techniques known in the industry to prevent the nut 90 from rotating relative to the washer 60 .
While the cross-sectional configuration of the shaped cavity 82 and shaped section 22 may vary, exemplary illustrations are shown in FIGS. 4-6 . For example, FIGS. 4 and 5 illustrate a sleeve 78 with radially inwardly extending projections 83 in the shape of the polygonal lobes 85 that interact with similarly configured polygonal lobes 26 on the axle 20 . Another example may be seen in FIG. 6 , where the radially inwardly extending projections in the shape of splines 88 interact with similarly configured splines on the axle 20 . The use of polygonal lobes 85 allows for ease of manufacturing the shaft 20 and the washer 60 , durability of the lobes 85 throughout the operating life, and ease of assembly in mating the shaft 20 , axle support assembly 30 , disc 50 , and washer 60 . Of course it should be easily recognized by one skilled in the art that the configuration, shape, and design of the inner shaped recess 82 , projections 83 , and outer surface 84 may be formed to interconnect with virtually any non-cylindrical shape or design of the shaped portion 22 on the axle 20 . For example, in the embodiments illustrated in FIGS. 4-6 , the inner shaped recess 82 completely interconnects, without any gaps, with the shaped portion 22 on the axle 20 . However, the shaped recess 82 does not have to mirror the shaped portion 22 completely, but may contain only a portion that interacts with the shaped portion 22 on the axle 20 to prevent any rotational movement of the washer 60 about the axle 20 . Further, those skilled in the art will appreciate that complete multiple projections are not required for all embodiments of the invention. For example, the inner shaped recess 82 may define only one lobe 84 that interconnects with the shaped portion 22 on the axle. For many embodiments, no more than one lobe 84 may be needed to prevent rotational movement of the washer 60 relative to the axle shaft 20 .
The locking washer 60 may be constructed of any suitable material. In the illustrated embodiment the washer 60 is formed from heat-treated steel with a GEOMET coating applied for corrosion resistance. A GEOMET coating is a water-based chromium-free coating widely used in the auto industry to provide resistance to corrosion. Of course, it should be readily apparent that other materials such as a mild steel or aluminum may be used to form the washer. It also should be readily apparent that the coating may be zinc, black oxide, or some other corrosion-resistant material and that the washer 60 may even be formed without any coating.
II. Manufacturing Process
The manufacturing process for the axle 20 , axle support assembly 30 , wheel bearing unit 40 , disc 50 , and nut 90 are well known in the art. For axles 20 with a polygonal shaped portion 22 , conventional manufacturing processes may be used, such as counter-rotational machining.
The locking washer 60 may be formed by a variety of techniques well known in the art for forming washers. In the preferred embodiments, the locking washer 60 may be formed by machining but other processes may be used. When machining the washer, a blank having the size and shape of the washer may be formed. Next, the blank may be machined to form the outer groove 80 , inner shaped recess 82 , and hole 74 . Of course, one skilled in the art should recognize that there is no particular order to machine the washer 60 . Other techniques well known in the art for fasteners that are suitable for fabricating the washer 60 include stamping, powder metallurgy, and cold heading.
III. Assembly on a Vehicle
The wheel end 10 may be assembled in a manner readily apparent to those skilled in the art. For example, once the axle 20 is interconnected into the vehicle drive train (not shown) and the wheel bearing 40 is placed within the knuckle 32 , the knuckle 32 and bearing unit 40 may be slid onto the axle 20 . The knuckle 32 may then be attached to the vehicle suspension system (not shown) or the vehicle frame (not shown). Next, the disc 50 is rotationally aligned with and inserted onto the shaped axle section 22 and engaged on the lobes 26 or splines. The locking washer 60 is then placed onto the axle 20 with the projections 83 (e.g., washer lobes 85 ) aligned to engage against the shaped portion 22 and prevent rotation of the locking washer 60 relative to the axle 20 . The sleeve 78 of the washer 60 fits within the sleeve groove 62 on the disc 50 . In the illustrated embodiment the sleeve 78 is not in contact with the disc 50 , but the washer 60 contacts the disc 50 at the disc contact surface 86 . The nut 90 is then threaded onto the axle 20 and tightened so that the axle support assembly 30 , disc 50 , and locking washer 60 are all firmly held on the axle 20 . Because the locking washer 60 is engaged with the shaped portion 22 on the axle 20 , it is prevented from rotating or transferring vibrational movements from the disc 50 to the nut 90 , preventing the nut 90 from backing off.
The foregoing discussion discloses and describes an exemplary embodiment of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without departing from the true spirit and fair scope of the invention as defined by the following claims. | A locking washer for axles on vehicles that prevents a nut from rotational movement relative to the axle. The locking washer includes a sleeve step having central passage with a non-cylindrical section that is rotationally coupled to the axle. The non-cylindrical section may include polygonal lobes or splines that engage a matching shaped portion on the axle. The washer is engaged directly on the shaped portion of the axle instead of the threaded portion of the axle and thereby reduces manufacturing costs and steps by eliminating machining of the threaded portion. The washer being engaged on the shaped portion prevents any relative movements between the axle and the washer from disturbances such as vibration, impact, and rotation. | 5 |
[0001] This application relies for priority on U. S. Provisional Patent Application Serial No. 60/416,534, filed on Oct. 8, 2002, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to snow grooming vehicles that use winches to assist in climbing steep inclines. The invention is also directed to level winding systems for winch assemblies.
[0004] 2. Description of Related Art
[0005] Tracked vehicles used in rugged terrain often employ winch assemblies to assist in maneuvering steep inclines. Snow grooming vehicles, for example, are sometimes equipped with winches that have cables that attach to fixed points on the incline to allow the vehicle to be anchored to the fixed point while sweeping up or down the slope. The cable anchor prevents the vehicle from turning over or sliding down the slope, which could occur on very steep inclines.
[0006] A winch-equipped vehicle typically carries a cable that extends outwardly through a rotatable boom. The boom is an elongated metal arm that guides the cable through a series of pulleys. Depending on the direction of intended travel, the boom is rotated to extend forwardly over the cab or to extend rearwardly away from the cab. The cable is typically carried on a drum, preferably a grooved drum, that is driven to control outlay and intake of the cable. A guide, preferably a level winder, is provided at the base of the boom to assist in aligning the cable as it is fed to and from the drum to prevent twisting of the cable.
[0007] Most prior art winches use vertical guides and worm gears that follow a linear path parallel to the drum's axis of rotation to align the cable with the drum grooves. As the load on the cable in such a system can be up to 10,000 lbs., the guide assembly must be constructed to accommodate such forces. These assemblies require a large degree of maintenance to prevent the guides and gears from rusting and breaking. However, constant lubrication is necessary. Additionally, these guide assemblies consume a large amount of space, which leaves limited space for the pulleys and rollers associated with the cable system. As a result, the diameter of the pulleys and rollers are often smaller than the minimum recommended cable bending radius. Bending cable about a radius less than the recommended bending radius shortens the life and reliability of the cable.
[0008] Some prior art systems use capstan systems to address the problems associated with the prior art guide assemblies described above. FIG. 5 illustrates a capstan system 100 that utilizes a linear guide system 110 . The torque applied to the guide system 110 is reduced by winding cable 120 around a capstan 130 . As a result, the force at the exit of the capstan 130 is a fraction, 1,000 lbs. for example, of the force in a conventional guide system. The cable 120 is guided from the capstan 130 through a sliding component 140 to a drum 150 . However, the capstan 130 itself occupies a great deal of space and is complex, due in large part to the motors required for driving the capstan. Further, maintenance for a capstan is complicated as changing a cable requires a large investment of labor. Moreover, the sliding component 140 must be constantly lubricated.
[0009] Thus, there is a need for a less complex and more compact guide assembly associated with such a winch, especially a level winder assembly.
SUMMARY OF THE INVENTION
[0010] An aspect of embodiments of the invention is to provide a winch assembly that has a relatively compact and simple design.
[0011] Another aspect of embodiments of the invention is to provide a winch assembly suitable for use on a snow grooming vehicle and further to provide a snow grooming vehicle equipped with such a winch.
[0012] A further aspect of embodiments of the invention is to provide a winch that is relatively easy to operate, may allow an operator to observe operation, and may extend the useful life of the wound cable.
[0013] Among other things, the invention is directed to a winch assembly that includes a drum, a driver, and a level winder. The drum carries a length of cable. The driver is coupled to the drum and rotates the drum to wind and unwind the cable. The level winder is disposed adjacent to the drum to guide the cable with respect to the drum, and is supported to move in an arc shaped path.
[0014] The invention is also directed to a winch assembly that includes a drum, a driver, and a level winder. The drum carries a length of cable. The driver is coupled to the drum and rotates the drum about a generally horizontal axis to wind and unwind the cable. The level winder is disposed adjacent to the drum to guide the cable with respect to the drum. The level winder is also supported to pivot about a generally vertical axis.
[0015] The invention is also directed to vehicle that includes a frame, an engine that is supported by the frame, a drive mechanism that is operatively connected to the engine, and a winch assembly that is supported by the frame. The winch assembly includes a drum that carries a length of cable. A driver is coupled to the drum for rotating the drum to wind and unwind the cable. A level winder is disposed adjacent to the drum to guide the cable with respect to the drum. The level winder is supported to move in an arc shaped path.
[0016] These and other aspects of embodiments of the invention will become apparent when taken in conjunction with the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Features of the invention are shown in the drawings, which form part of this original disclosure, in which:
[0018] [0018]FIG. 1 is a partial view of a tracked vehicle having a winch assembly in accordance with embodiments of the invention;
[0019] [0019]FIG. 2 is an enlarged side view of the level winder illustrated as a part of the tracked vehicle shown in FIG. 1;
[0020] [0020]FIG. 3 is a top schematic view of the level winder of FIG. 2;
[0021] [0021]FIG. 4 is a side perspective view of the level winder of FIG. 2; and
[0022] [0022]FIG. 5 is a view of a prior art capstan cable winding system.
DETAILED DESCRIPTION OF THE INVENTION
[0023] This invention is described for use on a tracked vehicle, particularly a snow grooming vehicle, for purposes of illustration only. However, the winch and level winder in accordance with embodiments of this invention may be used in any cable winding system. Further, the winch may be used on any type of vehicle, especially vehicles driven by rotatable tracks that may be driven over rugged terrain, such as steep inclines on mountains or ravines.
[0024] Throughout this description, reference is made to vertical and horizontal axes. It is understood that these axes are intended to refer to a vehicle position in which the vehicle is supported on a substantially horizontal surface.
[0025] [0025]FIG. 1 illustrates a vehicle 10 of the present invention. The vehicle 10 includes a frame 12 , an engine 14 supported by the frame 12 , a drive mechanism 16 operatively connected to the engine 14 , a winch assembly 24 supported by the frame 12 , and a boom 18 supported by the frame 12 . A cab 15 for having an operator and vehicle control elements is also supported by the frame 12 . In the illustrated embodiment, the engine 14 is not illustrated, but its location is indicated on the frame 12 . As would be appreciated by those skilled in the art, the engine 14 need not be positioned in the area indicated. Instead, the engine 14 may be located on the vehicle 10 in any alternative, suitable location.
[0026] The frame 12 can be fabricated from materials well known in the art, including but not limited to steel. Fabrication techniques well known in the art can be used to form and assemble the frame 12 .
[0027] The engine 14 can be any engine typically used in such vehicles. The size of the engine 14 will depend on the size and specific demands of the vehicle 10 . Preferably, the engine 14 is an internal combustion engine that can generate a high horse power.
[0028] The drive mechanism 16 is operatively connected to the engine 14 so as to move the vehicle 10 across a surface. The drive mechanism 16 allows for the vehicle 10 to move across land, ice, or water. The drive mechanism 16 may comprise an endless track, as illustrated by FIG. 1, wheels, or any component that will allow the vehicle 10 to travel.
[0029] The winch assembly 24 is supported on a winch frame 19 that is coupled to the frame 12 . The winch assembly 24 includes a drum 26 that carries a length of cable 28 , a driver 30 coupled to the drum 26 for rotating the drum 26 to wind and unwind the cable 28 , and a level winder 32 disposed at a base portion of the boom 18 and adjacent to the drum 26 to guide the cable 28 with respect to the drum 26 .
[0030] It is contemplated that the driver 30 is a hydraulic motor that is operatively connected to the engine 14 via a suitable hydraulic system. Of course, as would be appreciated by those skilled in the art, the driver 30 may be mechanically driven by the engine. Alternatively, the driver 30 my be an electrically-driven motor. It should be understood that the driver 30 may be of any type suited for this purpose without departing from the scope and spirit of the invention.
[0031] The boom 18 has a guide system that guides the cable 28 outward from (or inward to) the vehicle 10 . The guide system includes a series of pulleys 20 , a series of rollers 22 , or any combination of pulleys 20 and rollers 22 . The pulleys 20 are disposed on the boom 18 , and the cable 28 is fed around the pulleys 20 . The rollers 22 are disposed on the boom 18 , and the cable 28 is fed over the rollers 22 . The boom 18 is preferably formed of metal and may comprise a pair of parallel beams with the guide system supported therebetween. Alternatively, the boom 18 may be formed of a series of rigid members fixed together as an integral cantilever support. It is noted that the boom 18 may have any other suitable construction without departing from the invention.
[0032] As seen in FIG. 1, the boom 18 is supported for movement on a support platform 21 that is supported by the vehicle frame 12 , at least in part, via the winch frame 19 . Preferably, the boom 18 is supported for rotatable movement with respect to the platform 21 on the winch frame 19 . With this arrangement, the boom 18 can be oriented at various directions with respect to the drive mechanism 16 to accommodate different directions of travel. The direction of the boom 18 may be controlled by the operator or may be preset. Alternatively, other mounting structures may be implemented that allow for directional adjustment. It is also possible to use a fixed boom depending on the intended use of the vehicle 10 .
[0033] The cable 28 is typically metal, such as steel, but may be any material suitable for the intended purpose of the invention. Any known cable 28 capable of withstanding a large load is suitable. The diameter of the cable 28 and type of material are chosen to ensure that the load requirements of the vehicle 10 may be tolerated.
[0034] The drum 26 is mounted on the winch frame 19 such that it rotates about a longitudinal axis. The longitudinal axis is generally horizontal (when the vehicle 10 is supported on a horizontal surface). The drum 26 is sized to ensure that the appropriate amount of cable 28 can be completely wound onto the drum 26 . The cable 28 is wound across an outer circumferential surface of the drum 26 . The outer circumferential surface of the drum 26 may be smooth or grooved. In the preferred embodiment, the drum 26 is grooved, as illustrated in FIG. 3.
[0035] Grooves with the appropriate radius may be formed in the circumferential surface of the drum 26 so that when the cable 28 wraps around the drum, the cable 28 lies in what is essentially one continuous groove. The grooves may be added to the drum 26 by standard fabrication techniques, including but not limited to machining. Spaced grooves around the circumference of the drum 26 allow the cable 28 to be retained in the grooves during winding and unwinding. The grooves provide a tighter, neater, and more compact wind as compared to drums with a smooth surface. This provides for smoother operation and may enhance the life of the cable 28 .
[0036] The driver 30 is coupled to the drum 26 and rotates the drum 26 . The drum 26 rotates in one direction to wind the cable 28 and in the opposite direction to unwind the cable 28 . As mentioned above, the driver 30 may be an electric or hydraulic motor, for example. The driver 30 may be operatively connected to the vehicle engine 14 and/or electrical system or may be an independent component. The driver 30 preferably is sized to handle the load created by the drum 26 and the cable 28 .
[0037] The level winder 32 is disposed adjacent to the drum 26 to guide the cable 28 from the boom 18 with respect to the drum 26 . The level winder 32 is supported to move in an arc shaped path and is preferably supported to pivot about a generally vertical axis. The arc shaped path is largely defined by the pivoting of the level winder 32 about the generally vertical axis.
[0038] As illustrated in FIG. 2 and FIG. 3, the level winder 32 includes a rotatable support 34 , a cable support frame 36 that is connected to the rotatable support 34 , and a pair of rotatable pulleys 38 carried by the cable support frame 36 . The cable support frame 36 pivots with the rotatable support 34 . By this, the pair of pulleys 38 pivot with respect to the drum 26 .
[0039] The rotatable support 34 is mounted on the winch frame 19 . The rotatable support 34 is preferably operatively connected to a pair of rotatable support bearings 58 . The rotatable support bearings 58 are fixedly attached to the winch frame 19 . The rotatable support bearings 58 are connected to opposite ends of the rotatable support 34 so that the rotatable support 34 can freely rotate about a generally vertical axis, while being fixed in the other two directions. The rotatable support 34 is substantially the shape of a hollow cylinder with at least one slot 35 along the longitudinal length of the cylinder. Of course, any suitable support assembly may be used to allow the level winder 32 to pivot with respect to the drum 26 .
[0040] The winch assembly 24 further includes a rotatable pulley 60 that is disposed adjacent to the rotatable support 34 such that an outer edge of the rotatable pulley 60 lies within the slot 35 of the rotatable support 34 . The rotatable pulley 60 is disposed between two substantially parallel support plates 37 . The support plates 37 are fixedly attached to the rotatable support 34 such that the support plates 37 rotate with the rotatable support 34 about a generally vertical axis. The rotatable pulley 60 is mounted to the support plates 37 such that the rotatable pulley 60 can freely rotate about its generally horizontal axis. The rotatable pulley 60 directs the cable 28 from the boom 18 to the level winder 32 . The rotatable pulley 60 has a radius greater than or equal to the minimum recommended bending radius of the cable 28 .
[0041] The level winder 32 further includes at least one actuator 40 that is coupled to the rotatable support 34 . In the preferred embodiment, one upper bracket 39 is mounted to each support plate 37 , preferably above the axis of the rotatable pulley 60 . One end of the actuator 40 is pivotally attached to the upper bracket 39 . The opposite end of the actuator 40 is pivotally attached to the winch frame 19 , as seen in FIG. 1, and is in communication with a proximity switch 56 . Preferably, the actuator 40 is a hydraulic or pneumatic cylinder. Upon activation, the actuator 40 extends or retracts to push or pull the support plates 37 , which in turn rotates the rotatable pulley 60 , the rotatable support 34 , and the cable support frame 36 . As will be discussed below, this causes the pair of pulleys 38 to pivot with respect to the drum 26 to maintain the cable 28 in a predetermined position relative to the drum 26 . The desired predetermined position relative to the drum 26 is generally perpendicular, in this case.
[0042] Referring to FIGS. 2 - 4 , the cable support frame 36 includes an upper plate 41 and a lower plate 43 that are substantially parallel to one another. The cable support frame 36 has a longitudinal centerline CL that extends in a direction from the rotatable support 34 towards the drum 26 . Each support plate 37 further includes a pair of lower brackets 45 that are fixedly attached to the support plate 37 below the axis of the rotatable pulley 60 . The lower brackets 45 in each pair are spaced such that the cable support frame 36 can be disposed therebetween. A pair of level winder ball bearings 62 are disposed within the cable support frame 36 on opposite sides of the longitudinal centerline CL. The level winder ball bearings 62 are mounted and oriented in such a way as to create a generally horizontal axis. The level winder ball bearings 62 allow the cable support frame 36 to rotate within a fixed range about a generally horizontal axis.
[0043] A biasing mechanism 42 is coupled between the cable support frame 36 and the top of the support plates 37 , preferably at the upper brackets 39 . The biasing mechanism 42 maintains the cable support frame 36 in a predetermined position relative to the rotatable support 34 . The predetermined position relative to the rotatable support 34 is generally perpendicular. The biasing mechanism 42 can include a spring that retains the cable support frame 36 in a relatively horizontal position. Of course, any biasing mechanism can be used, including a resilient cable or hydraulic or pneumatic cylinder. By this construction, the cable support frame 36 can move slightly up or down with respect to the surface of the drum 26 to accommodate the thickness of the cable 28 wound on the drum 26 .
[0044] At the opposite end of the cable support frame 36 , the pair of pulleys 38 are disposed between the upper plate 41 and the lower plate 43 on opposite sides of the longitudinal centerline CL of the cable support frame 36 . The pair of pulleys 38 are connected to the cable support frame 36 with pulley bearings 47 . The pulleys 38 are generally oriented in the same plane and are spaced so that the cable 28 can pass between them. The centers of the pulleys 38 are aligned on an axis that is generally perpendicular to the longitudinal centerline CL of the cable support frame 36 .
[0045] The level winder 32 further includes a feeding mechanism 44 that is pivotally supported by the cable support frame 36 . The feeding mechanism 44 controls the tension and direction of the cable 28 as the cable 28 is fed from the pulleys 38 to the drum 26 . An embodiment of the feeding mechanism 44 is illustrated in detail in FIG. 4. The feeding mechanism 44 includes a pivot arm 55 , a pair of guiding rollers 46 , and a pair of tensioning rollers 49 .
[0046] In the preferred embodiment, the pivot arm 55 is disposed above the upper support plate 41 of the cable support frame 36 such that the pivot arm 55 and the cable support frame 36 extend in substantially parallel planes to one another. The pivot arm 55 is pivotally connected to the cable support frame 36 with a bearing 59 and a fastener 61 at a position along the longitudinal centerline CL of the cable support frame 36 . The pivot arm 55 has a first end and a second end. The first end of the pivot arm 55 extends beyond the cable support frame 36 in the direction towards the drum 26 .
[0047] The guiding rollers 46 are attached between a pair of roller support brackets 53 with bearings and fasteners. The roller support brackets 53 are fixedly attached to the first end of the pivot arm 55 and extend generally downward in such a manner that they do not interfere with the pair of pulleys 38 . The guiding rollers 46 are generally aligned in a vertical plane and are spaced and shaped such that the cable 28 can fit snugly between them.
[0048] The pair of tensioning rollers 49 are disposed at one end of a pair of cantilever brackets 51 . The cantilever brackets 51 each have a first end and a second end. The first ends of the cantilever brackets 51 are pivotally connected to the first end of the pivot arm 55 with bushings and fasteners. The second ends of the cantilever brackets 51 extend away from the pivot arm 55 and cable support frame 36 towards the drum 26 . The tensioning rollers 49 are connected to the second ends of the cantilever brackets 51 with bearings and fasteners. Preferably, the tensioning rollers 49 and the guiding rollers 46 are oriented such that their axes of rotation are perpendicular to one another. For example, in the preferred embodiment, the guiding rollers 46 rotate about generally horizontal axes and the tensioning rollers 49 rotate about generally vertical axes (when the vehicle 10 is supported on a horizontal surface). Alternatively, the guiding rollers 46 may rotate about generally vertical axes and the tensioning rollers 49 may rotate about generally horizontal axes (when the vehicle 10 is supported on a horizontal surface).
[0049] The feeding mechanism 44 further includes a pressure controller 48 . The pressure controller 48 is coupled to the tensioning rollers 49 to control the pressure between the tensioning rollers 49 to control feeding of the cable 28 . Preferably, the pressure controller 48 includes a hydraulic cylinder. Alternatively, the pressure controller 48 may include a pneumatic cylinder or any other resilient device. In the preferred embodiment, the pressure controller 48 includes a pair of hydraulic cylinders, as illustrated in FIG. 4.
[0050] The feeding mechanism 44 further includes a sensitivity controller 50 . The sensitivity controller 50 is coupled to the tensioning rollers 49 to adjust the distance between the tensioning rollers 49 . Preferably, the sensitivity controller 50 includes a first plate 64 mounted to one of the cantilever brackets 51 and a second plate 66 mounted to the other cantilever bracket 51 . A third plate 68 is disposed in between the cantilever brackets 51 and is fixedly attached to the pivot arm 55 . The sensitivity controller 50 further includes a pair of adjustment screws 52 . The adjustment screws 52 are used to set a gap between the first plate 64 and the third plate 66 and a gap between the second plate 68 and the third plate 66 .
[0051] As the adjustment screws 52 are tightened, the cantilever brackets 51 are pushed away from each other, thereby increasing the gap between the tensioning rollers 49 , which decreases the sensitivity to changes in the position of the cable 28 . Conversely, as the adjustment screws 52 are loosened, the cantilever brackets 51 will by drawn towards each other due to the pressure exerted by the pressure controller 48 . This in turn will decrease the gap between the tensioning rollers 49 , which increases the sensitivity to changes in the position of the cable 28 .
[0052] The feeding mechanism 44 further includes a position actuator 54 that is operatively coupled to the proximity switch 56 that activates the actuator 40 to pivot the level winder 32 . A first end of the position actuator 54 is pivotally connected to the pivot arm 55 . A second end of the position actuator 54 is pivotally connected to the proximity switch 56 . When the feeding mechanism 44 pivots beyond a certain predetermined position, the position actuator 54 signals the proximity switch 56 . The proximity switch 56 activates movement of the level winder 32 along the arc shaped path by signaling the actuator 40 . Any known type of proximity switch or position detector may be used.
[0053] In operation, the cable 28 starts in a fully wound position on the drum 26 . The cable 28 is fed from the drum 26 through the level winder 32 , through the rotatable support 34 , through the guide system within the boom 18 , and out one end of the boom 18 . The cable 28 is secured to a predetermined anchor point located on the terrain and the vehicle 10 moves away from the anchor point via the drive mechanism 16 . In order for the vehicle 10 to move away from the anchor point, the cable 28 must be lengthened or “played out” from the drum 26 . The driver 30 rotates the drum 26 such that the cable 28 unwinds from the drum 26 , thereby allowing the cable 28 to lengthen.
[0054] As the cable unwinds from the drum 26 , it releases from the drum at a release point 57 . The release point 57 moves parallel to the longitudinal axis of the drum 26 as the drum 26 rotates. The level winder 32 pivots in an arc such that the feeding mechanism 44 is substantially aligned with the release point 57 . This ensures that the cable 28 is generally perpendicular to the drum 26 at the release point 57 so that the cable does not twist or kink.
[0055] After the cable 28 releases from the drum 26 , the cable 28 passes in between the pair of tensioning rollers 49 . As the location of the release point 57 changes, the cable 28 exerts a greater pressure against one of the tensioning rollers 49 . When the resulting pressure on the pressure controller 48 exceeds a predetermined value, the pivot arm 55 pivots just enough to keep the cable 28 perpendicular to the drum 26 . When the pivot arm 55 reaches a maximum pivot point, the position actuator 54 activates the proximity switch 56 . The proximity switch 56 then signals the actuator 40 . The actuator 40 rotates the level winder 32 along an arc shaped path in the direction that the cable 28 is extending toward the drum 26 . As the level winder 32 rotates, the pivot arm 55 is drawn by the cable 28 to rotate independently to ensure the cable 28 remains perpendicular to the drum 26 . These adjustments by the feeding mechanism 44 are constantly repeated while the winch assembly 24 is in operation.
[0056] After the cable 28 passes through the tensioning rollers 49 , the cable 28 passes in between the guiding rollers 46 . The guiding rollers 46 ensure that the cable 28 is properly lined up to pass in between the pair of pulleys 38 , regardless of the amount of tension in the cable 28 . Once the cable 28 passes the pair of pulleys 38 , it travels through the cable support frame 36 and onto the rotatable pulley 60 . The rotatable pulley 60 feeds the cable 28 though the rotatable support 34 to the pulleys 20 and rollers 22 located in the guide system in the boom 18 .
[0057] To drive the vehicle 10 in a reverse direction towards the anchor point, the rotation of the drum 26 must be reversed by the driver 30 so that any slack in the cable 28 can be tightened. In other words, the cable 28 must be rewound onto the drum 26 . Further, the vehicle 10 may need the power of the winch assembly 24 help pull the vehicle 10 back towards the anchor point. The level winder 32 operates in the same manner as was described above, only the cable 28 moves in the opposite direction and the pulleys 20 , 60 , 38 and rollers 22 , 46 , 49 rotate in the opposite direction.
[0058] Due to the relatively compact design of the level winder 32 , the operator of the vehicle 10 can watch the winding process to ensure that the cable 28 is being properly unwound and wound, because the level winder 32 does not obstruct the view of the drum 26 .
[0059] It will be understood that the invention encompasses various modifications and alterations to the precise operating systems. For example, although the system is described for use in a heavy duty cable winding assembly, other windable materials may be used in the device, and the device may be adapted for use in smaller manufacturing environments. | A level winder is provided for winding cable in a winch system. The winch is suitable for use on a tracked vehicle, such as a snow grooming vehicle, to assist the vehicle in maneuvering on steep inclines. The level winder uses a pivoting pulley assembly to feed cable onto and off of a drum. | 4 |
BACKGROUND AND SUMMARY OF THE INVENTION
The invention relates to a method and apparatus of mining a desired geological stratum from surrounding undesired geological strata, the desired and undesired strata having different properties, especially different light reflecting properties. In the mining of coal and other valuable geological strata which occur in laminar fashion (seams), it is desirable to recover as much as possible of the valuable stratum without excessive contamination from the adjacent undesired stratum. Conventionally, this is accomplished by the operator himself. The operator of a mining maching periodically steers it in the direction of the boundary between the desired and undesired strata until contact is made with the undesirable stratum, which contact can be observed by noting the appearance of the mined product. The operator then backs the mining machine off a few inches and proceeds. Such a procedure is practical where the operator can see when contact has been made.
There are many situations when it is not practical for the operator to visually observe the mining operation. In many situations, for safety reasons, it is undesirable for an operator to be within sight of the mining face. In some situations, the stratum immediately above the desired stratum is unstable, and it is necessary to leave some of the desirable stratum in place to support the unstable stratum. Also, with auger-type mining machines and the like where an operator is stationed at a point remote from the mining face, it may be several minutes before the operator, by observing the appearance of the mined product, can tell that contact with the undesired stratum has been made, and this can result in excessive contamination of the mined material.
Devices have been constructed to indicate to the operator that the undesired stratum has been contacted so that the operator need not rely on visual inspection. One such device is shown in U.S. Pat. No. 3,333,893. In such device, the difference in the reflectivity between the desired stratum (coal) and the undesired stratum is utilized to provide an indication of when the undesired stratum has been reached. An auxillary cutting tooth is provided that operates at a fixed distance beyond the periphery of the cutting head for the mining machine itself. In practice, this distance cannot exceed about one-half inch, and the mining machine can only depart from its desired path by this fixed distance before the main cutting elements of the mining machine encounter the adjacent stratum. Utilizing such a structure which determines when the undesired stratum has actually been contacted, if the line of demarcation between the desired and undesired strata is irregular (as is usually the case), the operator has very little time to react and alter the course of the mining machine to remain entirely within the desired stratum. Also, since the auxillary cutting tool must operate at the head of the mining machine, and often contacts the rough, harsh, undesired stratum for significantly long periods of time, wear of the auxillary cutting tool is excessive, and worn bits must be replaced quite frequently.
There have also been other proposals for measuring the distance between the mining machine and the boundary of the undesired stratum, but normally such devices are based on the "back-scattering" of radioactive rays, such devices being bulky and dangerous for an inexperienced operator.
According to the present invention, a method and apparatus have been provided that minimize or eliminate all of the drawbacks inherent in the prior art. According to the present invention, it is possible to measure the distance from the mining machine to the extremity of the stratum being mined, and this can be accomplished utilizing a tool a having increased wear-life compared to the prior art, and in a simple and safe manner, using the difference between the light reflecting properties of the desired and undesired strata to indicate the distance from a reference to the undesired strata.
According to one aspect of the present invention, a method of mining a desired geological stratum from surrounding undesired strata having different light reflecting properties, is provided. The method comprises the steps of boring in a first direction (horizontally) into the desired stratum with a mining machine, and progressively penetrating the desired stratum with the mining machine while measuring the distance of the mining machine from the undesired strata in a second direction (up) perpendicular to the first direction. The measuring is accomplished by taking advantage of the different light reflecting properties of the desired stratum and the surrounding undesired strata. The direction of boring is controlled based upon the received measurements so that the machine generally stays within the desired stratum. The measuring is accomplished by boring through the desired stratum toward and into the undesired strata in the second direction, to generate chips, and continuously monitoring a property of the chips that is different for the undesired strata chips than for the desired stratum chips--preferably the light reflecting characteristics of the chips. The boring is accomplished by rotating a rotary drill bit with a peripheral speed that is low--i.e., only about 50 feet per minute, compared to the peripheral speed of a cutting head which is high--i.e., about 600 feet per minute--thus resulting in little wear to the drill bit, especially since it only need contact the normally abrasive undesired strata instantaneously.
The apparatus according to the present invention comprises a mining machine having a high speed cutting head, and adapted to penetrate a geological stratum in a first direction (horizontally). Means for penetrating the desired stratum and toward and into the undesired strata in a second direction (up) generally perpendicular to the first direction is also provided, such means preferably comprising a rotary drill mounted on the mining machine posterior of the cutting head. Means are provided for measuring the distance of the mining machine from the undesired strata in the second direction, this being accomplished by utilizing a light source mounted on the machine and a reflective surface and a photocell mounted in operative relationship with the light source, the chips generated during boring in the second direction being contacted by the light emitted from the light source, and reflected to the photocell. An abrupt change in the light reflecting properties of the chips--such as occurs when the undesired stratum is contacted--causes the photocell to change its conductivity, which effects operation through solid state circuitry to automatically stop the advance of the drill and return the drill to its original position. A digital counter counts the extent of penetration of the drill, and the counter displays the distance digitally until the next cycle of operation is begun at which time it automatically resets. Utilizing such apparatus, it is possible to always remain in the desired stratum since advance warning is provided when the boundary of the desired stratum is being reached, and in this way it is possible to leave any desired amount of desired stratum overhead that is necessary for safety purposes.
It is the primary object of the present invention to provide a simple, safe, and efficient method and apparatus for maintaining a mining machine in a desired geological stratum. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of an exemplary mining machine for practicing the method of the present invention;
FIG. 2 is a side view of the mining machine of FIG. 1;
FIG. 3 is a vertical cross-sectional view of exemplary measuring apparatus according to the present invention; and
FIG. 4 is an electrical schematic of exemplary control circuitry according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
In the following detailed description, the desired stratum to be mined will be referred to as "coal" although a wide variety of other desired strata are within the purview of the invention; the undesired strata will be referred to as "over-burden" and can comprise a wide variety of materials; and the first direction, the direction of penetration of the mining machine, will be referred to as "horizontal", and the second direction will be referred to as "up", even though the first and second directions may be different within the purview of the invention.
An exemplary mining machine for practicing the present invention is shown generally at 10 in the drawings. The mining machine 10 includes a conventional rotatable cutting head 12 for boring horizontally, in direction H, into the coal seam and for progressively penetrating the coal seam, and wing cutters 14 also may be provided. The mining machine 10 may be of a conventional type. According to the present invention, means 16 are provided for measuring the distance of the mining machine 10 from the over-burden B in the direction V, which is generally perpendicular to direction H.
The means 16, which is shown most clearly in FIGS. 3 and 2, includes means 18 for penetrating the coal A and moving toward and into the over-burden B in the direction V to generate chips, and means 20 for continuously monitoring a property of the generated chips that is different for the over-burden chips than for the coal chips. The means 20 preferably takes advantage of the difference in light reflectivity of the coal chips and the over-burden chips, and includes a chip collecting means 22, a light source 23, and light sensitive means (a photocell) 24 positioned so as to receive the light reflected off chips and the chip collecting means 22. The chip collecting means 22 includes a chips funnel 25 surrounding the penetrating means 18 for capturing chips generated thereby, and having a collecting cup 27 positioned at the termination 26 of the funnel 25. The collecting cup 27 may be of any suitable type, but preferably includes an interior reflective surface 28, and an opening 29 in the bottom to let the chips automatically fall out after being retained for a short period of time in the cup 27. All of the component parts of the means 20 are preferably mounted on a mounting plate assembly 32 which supports the apparatus and also protects the relatively fragile lamp 23 and photoconductive cell 24 from damage from flying lumps of material during the mining operation.
The penetrating means 18 preferably comprises a rotary drill, including a drill bit 34, means for rotating the drill bit 34, and means for linearly moving the bit 34 in direction V. Preferably, a single power source (43) is provided for both effecting rotating and linear movement of the bit 34.
The means for rotating the bit 34 preferably comprises a drive tube 36 which is operatively connected to the bit 34, and a gear 38 rigidly connected to the drive tube 36, a power source (43) being operatively connected to the gear 38. Preferably, the gear 38 is a worm gear, and is driven by a worm 40. The worm 40 is connected through key 41 to a power shaft 42 of a reversible motor 43. The bit 34 is operatively connected to the drive tube 36 by a drill tube 45. The drill tube 45 is preferably connected to the drive tube 36 by spline means 46, 47 which prevent relative rotational movement between the elements 36, 45, but allow relative linear movement therebetween along their axes (in direction V). The means for linearly moving the drill bit 34 preferably comprises the spline means 46, 47, and an internally threaded bushing 49 attached to the drill tube 45, and an externally threaded fixed rod 50 mounted to the mining machine 10, and concentric with the tubes 45, 36. The threads on the bushing 49 and rod 50 cooperate so that upon rotation of the tube 36--and thus the tube 45--with the rod 50 remaining stationary, the tube 45 will move linearly along the axis of the rod 50.
For convenience, it is preferred that the rod 50 has ten threads per standard length unit (i.e., ten threads per inch) so that a digital counting means provided for counting the number of revolutions of the drill bit 34 may be read directly in tenths of said standard length unit (i.e., in tenths of an inch). The peripheral speed of the bit 34 need only be about 50 feet per minute, and this low peripheral drill speed combined with the only momentary contact with a possibly abrasive stratum results in negligible drill bit wear. Comparatively, the peripheral speed of the cutting head 12 is conventionally high--i.e., 600 feet per minute, and this is the peripheral speed of conventional cutting tools for other photoelectric strata sensing apparatus (such as shown in U.S. Pat. No. 3,333,893).
The operator station 55 (see FIG. 4) is remote from the mining machine 10, and control means are provided for controlling operation of the penetrating means 18 in conjunction with the monitoring means 20. The control means preferably includes first circuitry means 56, with mostly solid state components, for determining the distance of movement of the penetrating means (drill bit 34) from a reference point in the direction V to the point where the drill bit 34 penetrates the over-burden; or first circuitry means comparable to means 56 only including the hookup of line 111 shown in dotted line in FIG. 4 rather than the hookup of line 110, for determining the distance of movement of the penetrating means (drill bit 34) from the start of the coal seam A to the point where it penetrates the over-burden B (thus determining the thickness of the coal seam A); and second circuitry means 57 (mostly solid state) operatively connected to the light sensitive means 24 for effecting movement of the penetrating means 18 back toward the machine 10 after penetration of the over-burden. When the apparatus of FIG. 3 is utilized, determination of the distance of movement in direction V is simple, since it is directly proportional to the number of rotations of the drill bit 34 (and/or components rotatively rigidly connected thereto). Thus, the first circuitry means preferably comprises a reed switch 59 and a permanent magnet 60 mounted in the worm gear 38, each rotation of the gear 38 resulting in the magnet 60 passing the reed switch 59 once, and effecting operation thereof. The first circuitry means further comprises a conventional digital counter 62 for counting the number of rotations of the gear 38 in a given sequence and digitally displaying that number.
FIG. 4 shows one exemplary circuitry arrangement that is desirable for use with apparatus of FIG. 3. The circuit of FIG. 4 includes a digital counter 62, a monostable multi-vibrator 63 which emits a pulse through transistor 64 to the digital counter 62 each time reed switch 59 is closed, the multi-vibrator 63 insuring that only one pulse is delivered to the counter 62 for each revolution; a voltage comparator 65 for comparing the voltage delivered from photocell 24 to a reference voltage, and a potentiometer 66 for adjusting the reference voltage which the voltage comparator 65 compares to the voltage from the photocell 24. Four different voltage dividers are provided by resistors 67, 68; 69, 70; 71, 72; and 92, 100. Line 73 is the main power line while line 74 is an accessory power line for the lamp 23 and photocell 24. Forward and reverse limit switches 75, 76 are operatively connected to line 74, the limit switches being mounted on the mining machine for cooperation with the drill tube 45. While such switches are not shown in FIG. 3, it will be understood that any conventional actuators for limit switches may be provided associated with the structure of FIG. 3.
Main power line 73 is connected up to solenoid valve 77 which controls the reversible motor 43 for rotating power shaft 42, valve 77 having a forward solenoid 106 and a reverse solenoid 107.
Resistor 79 is connected in parallel with voltage comparator 65, and ultimately to the common ground 80. Four SCRs 81, 82, 83 and 84 respectively are connected up to various of the circuitry components and ultimately to ground 80. Gate capacitors 85, 86, 87 and 88 are associated with the respective SCRs, charging current for these capacitors being provided by the voltage drop across resistors 89, 92, 91 and 71 respectively. Resistors 90 and 93 serve to expedite the discharge of capacitors 86 and 88 respectively. Resistors 94 and 95 respectively provide a small current from main line 73 to SCRs 82, 84, respectively, to maintain them in a conducting state in the absence of gate current. Resistor 96 and capacitor 97 determine the duration of pulses from the multivibrator 63. Transistor 98 serves to prevent SCR 83 from being turned on simultaneously with SCR 84 when conductor 73 is first connected to the 36 VDC power supply. Resistor 99 returns the base of transistor 98 to ground when the reverse limit switch goes to ground, thus permitting transistor 98 to conduct. Pushbutton 102 starts the measuring sequence.
When the effective measuring by the means 16 of the distance of the mining machine 10 from the over-burden B in the direction V is accomplished by determining the distance between a reference associated with the mining machine 10 and the over-burden B, the line 110 connection shown in solid line in FIG. 4 is utilized. However, under some circumstances it is desirable to accomplish the effective measurement of the machine 10 from the overburden B in the direction V by determining the thickness of the coal seam A. This is accomplished merely by providing the line 111 connection, shown in dotted line in FIG. 4, instead of the line 110 connection, so that resistor 67 is connected up to the bottom of resistor 101 instead of to the top of resistor 69.
Apparatus according to the present invention having been described, a mode of operation thereof will now be set forth.
Mining machine 10 is moved into the coal seam A in direction H, the cutting portions 12, 14, effecting cutting of the coal seam A. After penetration of the seam a predetermined distance, the mining machine 10 is stopped, and the machine operator at the operator station 55 depresses the start-push button 102 of the control circuitry (see FIG. 4). At the time the start-push button 102 is depressed, the forward limit switch 75 is open, the reed switch 59 is open, the solenoid valve 77 is not energized, the light source 53 is energized, the photocell 24 is receiving light reflected off of the surface 28 of chip receptacle 27, reverse limit switch 76 is at 5 volts DC, SCRs 81 and 83 are off and 82 and 84 are conducting, transistors 64 and 98 are in their blocking states, the internal solid state switch in the voltage comparator 65 is open, and the digital counter 62 shows the extent of drill penetration from the previous cycle.
Once the start-push button 102 is depressed, the SCR 81 is turned on and SCR 82 is turned off by the commutating action of capacitor 81, the digital counter 62 is reset to 0, and the forward solenoid 106 of solenoid valve 77 is energized which causes motor 43 to turn shaft 42 in the forward direction. Shaft 42 acts through worm 40 and worm gear 38 to rotate drive tube 36, which is operatively connected to drill tube 45 through the keying means 46, 47. Drill tube 45 also moves linearly in direction V as it rotates since the internal threads on threaded bushing 49 thereof cooperate with the threads on fixed rod 50, the keying means 46, 47 allowing the relative linear movement between the elements 3, 45.
As the drill bit 34 is rotated, permanent magnet 60 will activate reed switch 59 upon each rotation of gear 38. Once SCR 81 is turned on by the depression of start-push button 102, the voltage applied to the base of transistor 64 by the voltage divider 67, 68 is incapable of sustaining transistor 64 in its blocking state. Thus, each time reed switch 59 closes, the multi-vibrator 63 emits a pulse through transistor 64 to digital counter 62, the multi-vibrator 63 insuring that only one pulse is delivered to counter 62 for each revolution of the gear 38.
As the advance of the drill 34 in direction V continues, the reverse limit switch 76 goes to ground permitting transistor 98 to conduct. Even with the limit switch 76 grounded, however, the voltage applied by the voltage divider 69, 70, is insufficient to turn on SCR 83.
Once drill bit 34 penetrates the coal seam A, chips are generated, which chips fall through the chips funnel 25 into the chip collecting bin 27, covering the reflective surface 28 as they slowly fall through opening 29 in chips cup 27. This results in a decrease in the amount of light reflected to the photocell 24 from lamp 23, effecting an increase in the resistance of photocell 24. The increase in resistance of photocell 24 causes the voltage delivered to voltage comparator 65 from the top of resistor 79 to decrease below the reference voltage which has been set by the potentiometer 66. The potentiometer 66 will be adjusted depending upon the relative light reflecting characteristics of the coal seam A and the material of the over-burden B. With the decrease of the voltage supplied from the top of resistor 79 relative to that supplied through potentiometer 66, the comparator 65 connects the junction of resistors 100, 101 to ground, capacitor 86 then discharging through resistors 90, 92.
As rotation of drill bit 34 and advancement in direction V continues, the number of revolutions thereof is counted by the counter 62 until the drill bit 34 hits the over-burden B, at which point chips are generated from the over-burden B and falling through funnel 25 into collecting cup 27. Because of the greater light reflective characteristics of the over-burden chips, photocell 24 receives more light and the resistance thereof decreases, causing the voltage at the top of resistor 70 to again exceed the reference voltage supplied by potentiometer 66. Then the internal solid state switch in voltage comparator 65 opens permitting current to flow from main line 73 to gate capacitor 86, which turns on SCR 82, and through the commutating action of capacitor 104 turns SCR 81 off. This de-energizes the forward solenoid 106, stopping the forward advance of the drill, and increasing the voltage applied by the voltage divider 69, 70 to the gate capacitor 87 turning SCR 83 on, with SCR 84 turned off by the commutating action of capacitor 105. Also, the turning off of SCR 81 increases the voltage applied to the base of transistor 64, returning it to its blocking state and locking in the number of counts in the digital counter 62, preventing any further pulses from counter-switch 59 and multi-vibrator 63 from reaching the counter 62.
When the line 110 connection, shown in solid line in FIG. 4, is employed, the number displayed by the digital counter 62 is a representation of the distance the drill bit 34 has advanced from the reference point to where it contacted over-burden B. However, when the line 111 connection, shown in dotted line in FIG. 4 is employed in place of the line 110 connection, the number displayed by the digital counter 62 is a representation of the distance the drill bit has moved in direction V after contacting coal seam A, or the thickness of the coal seam A. This is because when the line 111 connection is employed the digital counter 62 counts only when the internal solid state switch in voltage comparator 65 connects the junction of the resistors 100 and 101 to ground; this would permit transistor 64 to conduct only while the chips generated by drill bit 34 possess low reflectivity. Preferably, the threads of elements 49, 50 are provided in tenths of a standard unit length so that the digital counter may be read directly in tenths of that standard unit length--for instance, in tenths of an inch.
When SCR 83 is turned on, the reverse solenoid 107 is energized, reversing the direction of rotation of the shaft 42 by the motor 43, and thus moving the drill bit 34 back to its original position. The drill continues to rotate in the reverse direction until the reverse limit switch 76 is actuated thereby applying 5 volts DC to the voltage divider 71, 72, and turning on SCR 84, which turns off SCR 83 through the commutating action of capacitor 105. Turning off SCR 83 de-energizes the reverse solenoid thus terminating power to the drill motor 43. The operator then inspects the effective distance the mining machine is from the over-burden B by viewing the digital counter 62, whether it gives the reading in distance of the over-burden B from a reference, or thickness of the coal seam A over the machine 10, makes any correction to the steering of the mining machine 10 that is necessary, and continues penetration in direction H of the mining machine 10 until the next desired test point is reached. The time consumed by the penetration of the coal seam A and over-burden B in direction V results in only about a one minute delay for each test stop in the continuous mining operation.
It will thus be seen that according to the present invention a method and apparatus have been provided that provide for a simple, safe, and efficient determination of the effective distance of the mining machine from the over-burden, to allow exact control of the mining machine to keep it within the coal seam. While the invention has been herein shown and described in what is presently conceived to be the most practical and preferred embodiment thereof, it will be apparent to those of ordinary skill in the art that many modifications may be made thereof within the scope of the invention, which scope is to be accorded the broadest interpretation of the appended claims so as to encompass all equivalent structures and methods. | A method and apparatus for mining a desired geological strata, such as a coal seam, from surrounding undesired geological strata. A bore is formed in the coal seam in a first direction, and while progressively penetrating the coal seam with a mining machine, the distance of the mining machine from the undesired strata in a second direction perpendicular to the first direction is effectively measured. The measuring is accomplished by generating chips by boring upwardly through the coal seam toward and into the undesired strata, and reflecting light off of the chips, the difference in reflectivity between the chips from the coal and from the undesired stratum serving to indicate when the undesired stratum has been reached. The distance of upward movement of the drill from a reference until the reflectivity of the undesired stratum is detected is measured, or the thickness of the coal seam above the machine is measured, and the mining machine is controlled based upon such measurements. A single power source can be employed for both rotating the drill and reciprocating the drill in measured progress toward the undesired stratum. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to PCT/EP2013/056112 filed Mar. 22, 2013, which claims priority to European application 12161874.8 filed Mar. 28, 2012, both of which are hereby incorporated in their entireties.
TECHNICAL FIELD
[0002] The present invention relates to the processing of hybrid metal/ceramic parts in the field of gas turbine technology. It refers to a method for separating a metal part from a ceramic part according to the preamble of claim 1 .
BACKGROUND
[0003] Modern, next generation gas turbine hot gas path components consist of more than one material (see for example EP 1 362 983 A2, US 2010/0166551 A1, EP 2 017 433 A2, EP 2 108 785 A2, US 2010/0074759 A1 or U.S. Pat. No. 7,452,189 B2) to adjust the properties of each region of the component to its environment.
[0004] Very often those parts consist of ceramic and metal sections to make use of the higher temperature capability of the ceramic where needed and of the strength/and/or toughness of the metal where needed.
[0005] After completion of one service interval, the components need to be disassembled and worn pieces need to be replaced. Typically the ceramic part cannot be reworked and will be replaced, while the metal part can be reused or reworked (e.g. crack brazing). Such modular parts are often joined together by brazing (see US 2008/0056888 A1, US 2008/0307793 A1).
[0006] Limited information is available on disassembly of modular parts. US 2008/0229567 A1 discloses a process that intends to leach out only a ceramic matrix in which ceramic fibres are embedded and to restore the ceramic afterwards by infiltration. However, the leaching process is not disclosed. In any case, leaching (which generally involves a liquid) is typically a slow process, whereas a gaseous process that is executed at higher temperatures, might have the advantage of the exponential temperature dependence of most chemical reactions, thus providing a faster process.
[0007] Furthermore, the leaching process would only be suitable for a local repair of the ceramic part, which is very unlikely considering the brittle behaviour of ceramics and does not take advantages of the modular design of the component, which aims at replacing worn pieces instead of doing repair, which anyway can only cope with limited damages.
[0008] Especially, when considering multiple reconditioning or heavy damages of gas turbine parts, a disassembly is unavoidable. Thus, although US 2008/0229567 A1 provides a process that is beneficial for some niche applications, it does not solve the problem of how to efficiently remove the ceramic part from the metallic part.
[0009] Another process known in the art for disassembling of brazed parts is de-brazing, i.e. subjecting the component to high temperatures in order to re-melt the braze alloy. However, this requires temperatures exceeding the original braze temperature, since the melting point depressants have diffused during service operation and thus the liquidus temperature of the braze joint has increased.
[0010] Therefore, the component, especially low tolerance joints, is prone to thermal deterioration. In addition, the braze alloy is only re-melt but not dissolved, i.e. residues are still attached to the joining surfaces even if the parts can be separated. However, these joining surfaces have complicated geometries and tight tolerances, so that every mechanical cleaning of the joining surfaces risks to modify their geometry beyond the tolerance, especially when low tolerance parts are involved.
SUMMARY
[0011] It is an object of the present invention to provide a method, which offers a time efficient one step process for disassembly, cleaning, preparation for repair and joining of a hybrid component, especially for gas turbines, said process being used to separate a ceramic or ceramic composite from a metal, e.g. separating ceramic parts from metallic parts of a modular hybrid gas turbine component.
[0012] It is another object of the invention to provide a process, which can be used for the simultaneous cleaning of the metal part and/or ceramic composite part, such that the metal part can be brazed without further cleaning or oxide removal and in case no rework of the metal part is required the part is immediately ready for joining with a new ceramic part.
[0013] It is a further object of the invention to provide a process, which can be used as a batch process, not a single piece process, and which allows economic ceramic removal for entire sets in very short time.
[0014] These and other objects are obtained by a method according to claim 1 .
[0015] The inventive method is for separating a metal part from a ceramic part, which are joined at a connecting face within a hybrid component, especially of a gas turbine. It is characterized in that said hybrid component is subjected to an inert/reducing atmosphere in a gaseous process at elevated temperatures to dissolve the connection between said metal part and said ceramic part.
[0016] According to an embodiment of the invention said reducing atmosphere contains halogens as reactive species.
[0017] Specifically, said halogens have a higher electronegativity than oxygen, on either Pauling Scale, Mulliken Scale or Allred-Rochow Scale.
[0018] More specifically, said halogens comprise F.
[0019] Alternatively, said halogens comprise Cl.
[0020] According to another embodiment of the invention said ceramic part itself is dissolved or disintegrated as a whole.
[0021] Specifically, said ceramic part is a partially or fully stabilized ceramic, whereby, during the process, the stabilizing phase is removed by phase change from the ceramic, such that the entire ceramic destabilizes and is readily removed or spalls of, as soon as the content of the stabilizing phase decreases below a stability limit, especially during a temperature change, when being cooled down from reaction temperature.
[0022] More specifically, said ceramic part is a partially or fully stabilized oxide ceramic.
[0023] Especially, said partially or fully stabilized oxide ceramic is zirconia stabilized with a rare earth or an alkaline earth element or combinations thereof.
[0024] Preferably, said rare earth or alkaline earth element is one of Sc, Y, Sm, Mg, Ca, Ce, Ta or Sr.
[0025] According to another embodiment of the invention, said ceramic part contains an alkali silicate, alkali borosilicate, earth alkali silicate, earth alkali borosilicate or any of those compounds with the addition of a semimetal or metalloid, and that, during the process, the halogen attacks the Si containing phase, which results in dissolution and removal of the entire ceramic.
[0026] According to a further embodiment of the invention a joint layer is disposed between said metal part and said ceramic part, and that said halogen attacks said joint layer, such that said metal part and said ceramic part are separated from each other.
[0027] Specifically, said joint layer comprises a braze alloy and/or a mineral glue or a high temperature resistant cement.
[0028] According to another embodiment of the invention, said hybrid component is put in a reactor, which is heated to more than 850° C., preferably to more than 1000° C. but not more than 1150° C.
[0029] According to a further embodiment of the invention said process is conducted as a batch process to allow economic ceramic-metal separation for entire sets in very short time.
[0030] According to a just another embodiment of the invention the metal part and/or ceramic composite part is simultaneously cleaned in said process, such that it can be brazed without further cleaning or oxide removal and, in case no rework of the metal part is required, is immediately ready for joining with a new ceramic part, and/or the ceramic composite part cane be re-used.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The present invention is now to be explained more closely by means of different embodiments and with reference to the attached drawings.
[0032] FIG. 1 shows different steps in a method for removing the ceramic part from a hybrid metal/ceramic component in a pulsed process in a reactor according to an embodiment of the invention; and;
[0033] FIG. 2 shows different steps in a method for separating the ceramic part from the metal part of a hybrid metal/ceramic component in a pulsed process in a reactor according to another embodiment of the invention.
DETAILED DESCRIPTION
[0034] FIG. 1 shows different steps in a method for removing the ceramic part from a hybrid metal/ceramic component in a pulsed process in a reactor according to an embodiment of the invention.
[0035] The process starts with a (simplified exemplary) hybrid component 10 , which comprises a metal part 11 and a ceramic part 12 , which are jointly connected at a connecting face 13 ( FIG. 1( a )).
[0036] The hybrid component 10 is put into a reactor 15 , which can be heated by means of a heater 14 ( FIG. 2( b )). The inner space 24 of the reactor 15 can be filled with one or more gases through a gas supply line 18 , which can be closed by means of valve 16 . On the other hand, the inner space 24 can be pumped out or evacuated by means of pump 17 through a pumping line 19 .
[0037] When the process begins at a low temperature T1 (e.g. room temperature), the reactor 15 is heated up to an elevated temperature T2, which is substantially higher than the temperature T1 ( FIG. 1( c )).
[0038] Then, a first inert/reducing atmosphere A1 containing hydrogen (H 2 ) is established in the inner space 24 of the reactor 15 by introducing gas through gas supply line 18 ( FIG. 1( d )).
[0039] By introducing a reactive halogen, e.g. F, in form of an HF gas, through gas supply line 18 , a second reducing atmosphere A2 is established, which begins to destabilize the ceramic part 12 of the hybrid component 10 ( FIG. 1( e )).The reactor 15 is operated in a pulsed mode, i.e. the reaction products are removed from the reactor 15 by pumping out the gas with pump 17 ( FIG. 1( f )) and supplying fresh gas afterwards through gas supply line 18 ( FIG. 1( g )). Several of such cycles ( FIG. 1( f )→ FIG. 1( g )→ FIG. 1( f )→ FIG. 1( g )) are done, until the ceramic part 12 is completely removed and the surface of the metal part 11 cleaned ( FIG. 1( h )). In the following, some examples of the method according to the invention will be explained.
1. Example
[0040] Disassembly of a modular hybrid part, having a ceramic airfoil fabricated from yttria stabilized zirconia (YSZ) brazed to a load-carrying spar fabricated from an SX superalloy:
Aim: A set of modular hybrid parts shall be reconditioned, the ceramic portion requires replacement due to foreign object damage (FOD). The expensive metal part, which consists of an SX superalloy can be used for another service cycle; Process: the parts are put in a reactor 15 , which is heated to more than 850° C., preferably to more than 1000° C. but not more than 1150° C. To achieve a reducing atmosphere the reactor 15 is flooded with H 2 . As reactive halogen, F is introduced as HF gas. The reactor 15 is operated in a pulsed mode, i.e. the reaction products are removed from the reactor 15 by pumping out the gas and supplying fresh gas afterwards. Several of such cycles are done; Result: The gas readily destabilizes the YSZ, which disintegrates, the braze alloy interface is attacked and cleaned on the surface as well. Thus the complex-shaped joining surface of the metallic part with its tight tolerances is preserved without the need for further (mechanical) cleaning and is ready for being brazed to a new ceramic part. Additionally, the metal parts are simultaneously cleaned by this treatment, thus the cracks can be repaired without further preparation.
2. Example
[0044] Disassembly of a modular hybrid part, fabricated from a DS superalloy, with a ceramic portion on the pressure side of the trailing edge (cut-back trailing edge, e.g. shown in document WO 2010/028913 A1) fabricated from YSZ:
Aim: preserve the expensive DS component and replace only the worn trailing edge insert; Process: the parts are put in a reactor 15 , which is heated to more than 850° C., preferably to more than 1000° C. but not more than 1150° C. To achieve a reducing atmosphere the reactor 15 is flooded with H 2 . As reactive halogen, F is introduced as HF gas. The reactor 15 is operated in a pulsed mode, i.e. the reaction products are removed from the reactor 15 by pumping out the gas and supplying fresh gas afterwards. Several of such cycles are done; Result: the YSZ insert from the pressure side of the trailing edge is readily dissolved, the rest of the component is preserved and the surface is clean and ready for brazing a new insert into the trailing edge. Considering the fragile nature of the small joining surface, any mechanical cleaning process is prohibitive.
3. Example
[0048] Disassembly of a modular hybrid part, having a ceramic airfoil fabricated from YSZ which is attached to the root section using a bi-cast process, i.e. the parts are interlocked:
Aim: preserve the precision-machined root section and replace the airfoil, which was damaged by FOD; Process: the parts are put in a reactor 15 , which is heated to more than 850° C., preferably to more than 1000° C. but not more than 1150° C. To achieve a reducing atmosphere the reactor 15 is flooded with H 2 . As reactive halogen, F is introduced as HF gas. The reactor 15 is operated in a pulsed mode, i.e. the reaction products are removed from the reactor 15 by pumping out the gas and supplying fresh gas afterwards. Several of such cycles are done; Result: the YSZ is readily de-stabilized and disintegrated. Thus is can be removed from the interlocking features of the root. A replacement airfoil can be brazed to the cleaned root.
4. Example
[0052] Disassembly of a modular hybrid part, having a ceramic section fabricated from a ceramic matrix composite (CMC) comprising SiN fibres in a water-glass based matrix, which is attached using a mineral glue to a complex shaped superalloy section that includes channels for instrumentation and was build employing selective laser melting:
Aim: remove worn section but preserve expensive instrumented platform; Process: the parts are put in a reactor 15 , which is heated to more than 850° C., preferably to more than 1000° C. but not more than 1150° C. To achieve a reducing atmosphere the reactor 15 is flooded with H 2 . As reactive halogen, F is introduced as HF gas. The reactor 15 is operated in a pulsed mode, i.e. the reaction products are removed from the reactor 15 by pumping out the gas and supplying fresh gas afterwards. Several of such cycles are done; Result: while the ceramic SiN fibres resist the HF attack, the water-glass based matrix is strongly attacked, thus the CMC is readily removed from the expensive platform, which is cleaned at the same time and can be reused.
[0056] FIG. 2 shows different steps in a method for separating the ceramic part from the metal part of a hybrid metal/ceramic component in a pulsed process in a reactor according to another embodiment of the invention.
[0057] The process starts with a component 20 , which comprises a metal part 21 , which is joined with a ceramic part 22 by means of a joint layer 23 ( FIG. 2( a )).
[0058] The component 20 is put into a reactor 15 , which can be heated by means of a heater 14 ( FIG. 2( b )). The inner space 24 of the reactor 15 can be filled with one or more gases through a gas supply line 18 , which can be closed by means of valve 16 . On the other hand, in the inner space 16 can be pumped out or evacuated by means of pump 17 through a pumping line 19 .
[0059] The reactor 15 is heated up to a temperature T2, which is substantially higher than room temperature ( FIG. 2( a )).
[0060] By introducing hydrogen and a reactive halogen, e.g. F, in form of an HF gas, through gas supply line 18 , a reducing atmosphere A2 is established, which begins to destabilize the joint layer 23 of the component 20 ( FIG. 2( a )).
[0061] The reactor 15 is operated in a pulsed mode, i.e. the reaction products are removed from the reactor 15 by pumping out the gas with pump 17 ( FIG. 2( b )) and supplying fresh gas afterwards through gas supply line 18 ( FIG. 2( c )). Several of such cycles ( FIG. 2( b )→ FIG. 2( c )→ FIG. 2( b )→ FIG. 2( c )) are done, until the joint layer 23 is completely removed and both parts 21 , 22 are separated and the surface of metal part 21 cleaned ( FIG. 2( d )).
5. Example
[0062] Disassembly of a modular hybrid part, having a ceramic airfoil fabricated from Al 2 O 3 that is attached to the root section using a buffer layer (joint layer) which consists of porous YSZ:
Aim: preserve the precision-machined root section and replaced worn airfoil; Process: the parts are put in a reactor 15 , which is heated to more than 850° C., preferably to more than 1000° C. but not more than 1150° C. To achieve a reducing atmosphere the reactor 15 is flooded with H 2 . As reactive halogen, F is introduced as HF gas. The reactor 15 is operated in a pulsed mode, i.e. the reaction products are removed from the reactor 15 by pumping out the gas and supplying fresh gas afterwards. Several of such cycles are done; Result: In this case the airfoil, which consists of Al 2 O 3 is only slowly attacked by the HF gas. However the porous buffer layer, which is fabricated from porous YSZ, dissolves readily in the HF gas, thus the Al 2 O 3 airfoil can be easily detached from the metallic root section.
[0066] So the method offers a time efficient one step process for disassembly, cleaning, preparation for repair and joining of a hybrid metal/ceramic component, with the following characteristics:
Said process is used to separate a ceramic from a metal, e.g. separating ceramic parts from metallic parts of a modular hybrid gas turbine component. The halogen attacks preferably the stabilizing phase within the ceramic body or section, thus after dissolving only a few percent of the ceramic, the amount of the stabilizing phase has decreased below the stability limit and the entire ceramic disintegrates. This enables a very efficient removal of the ceramic with a minimum of reactive species. The halogen attacks and cleans the braze alloy/ceramic interface. Said braze alloy attacks the mineral glue or cement used for joining ceramic and metallic parts together. The process is a batch process, not a single piece process, which allows economic ceramic removal for entire sets in very short time. A benefit is the simultaneous cleaning of the metal part, thus the metal part can be brazed without further cleaning or oxide removal and in case no rework of the metal part is required the part is immediately ready for joining with a new ceramic part. So the process offers a time efficient one step process for disassembly, cleaning, preparation for repair and joining.
[0073] Further examples of the method according to the invention relate to:
Abradables (conservation, cleaning of BC); Preservation of a specific metallic surface texture; Top layer from ceramic multi-layer coating (sacrificial surface sealing, EBC) Cleaning of clogged effusion/transpiration cooling holes. | The invention relates to a method for separating a metal part from a ceramic part, which are joined at a connecting face within a modular hybrid component, especially of a gas turbine. The method includes said component being subjected to a reducing atmosphere in a gaseous process at elevated temperatures to dissolve the connection between said metal part and said ceramic part, especially by dissolving the ceramic part itself. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of an earlier filing date from U.S. Provisional Application Ser. No. 62/158,059 filed May 7, 2015, the contents of which are incorporated by reference herein in their entirety.
BACKGROUND
The subject matter disclosed herein relates to elevator systems. More specifically, the subject disclosure relates to tension members for elevator suspension and/or driving.
Elevator systems utilize a lifting means, such as ropes or belts operably connected to an elevator car, and routed over one or more sheaves, also known as pulleys, to propel the elevator along a hoistway. Lifting belts in particular typically include a plurality of wires at least partially within a jacket material. The plurality of wires are often arranged into one or more strands and the strands are then arranged into one or more cords.
Lifting belts may be required to meet certain established standards to be certified for fire resistance, and/or may require the installation of fire mitigation systems. Thus, the jacket material is often formed of a material with increased fire resistant properties at the outer surface of the belt. Such materials, however, can have non-optimal wear durability and other mechanical performance characteristics.
BRIEF SUMMARY
In one embodiment, a belt for suspending and/or driving an elevator car of an elevator system includes a plurality of tension members arranged in a lengthwise direction and a jacket substantially retaining the plurality of tension members. The jacket includes a traction portion, a back portion, and an inner portion between the traction portion and the back portion. The traction portion is formed from a first material and the inner portion is formed from a second material having an increased fire resistance compared to the first material.
Additionally or alternatively, in this or other embodiments one or more intermediate layers are located between the traction portion and the inner portion, and/or between the inner portion and the back portion.
Additionally or alternatively, in this or other embodiments the one or more intermediate layers are formed from a fiberglass fabric, another fire resistant fabric, or a wire metal mesh.
Additionally or alternatively, in this or other embodiments the back portion has increased fire resistance relative to the traction portion.
Additionally or alternatively, in this or other embodiments the traction portion and the back portion are formed from the same material.
Additionally or alternatively, in this or other embodiments an edge treatment is located at one or more lateral edges of the belt to increase fire resistance of the lateral edges.
Additionally or alternatively, in this or other embodiments the edge treatment includes a layer of material located at one or more lateral edges of the belt having increased fire resistance relative to the traction portion.
Additionally or alternatively, in this or other embodiments the layer of material is formed from the second material.
Additionally or alternatively, in this or other embodiments the edge treatment extends in board partially along the traction portion and/or the back portion.
Additionally or alternatively, in this or other embodiments the edge treatment includes an at least partially exposed tension member.
Additionally or alternatively, in this or other embodiments the tension member is one of a cord formed from a plurality of metal wires, or metallic strips located at the edge portion
Additionally or alternatively, in this or other embodiments the edge treatment has a C-shaped cross-section and mechanically interlocks with the jacket.
Additionally or alternatively, in this or other embodiments the edge treatment is preformed and secured to the jacket during formation of the jacket.
In another embodiment, an elevator system includes an elevator car movable along a hoistway, a machine located in the hoistway to drive rotation of a traction sheave, and a belt operably connected to the elevator car and interactive with the traction sheave such that rotation of the traction sheave drives movement of the elevator car along the hoistway. The belt includes a plurality of tension members arranged in a lengthwise direction and a jacket substantially retaining the plurality of tension members. The jacket defines a traction portion interactive with the traction sheave, a back portion, and an inner portion between the traction portion and the back portion. The traction portion is formed from a first material and the inner portion is formed from a second material having an increased fire resistance compared to the first material.
Additionally or alternatively, in this or other embodiments one or more intermediate layers are located between the traction portion and the inner portion, and/or between the inner portion and the back portion.
Additionally or alternatively, in this or other embodiments the one or more intermediate layers are formed from a fiberglass fabric, another fire resistant fabric, or a wire metal mesh.
Additionally or alternatively, in this or other embodiments the back portion has increased fire resistance relative to the traction portion.
Additionally or alternatively, in this or other embodiments the back portion and the traction portion are formed from the same material.
Additionally or alternatively, in this or other embodiments an edge treatment is positioned at one or more lateral edges of the belt to increase fire resistance of the lateral edges.
Additionally or alternatively, in this or other embodiments the edge treatment comprises a layer of material having increased fire resistance relative to the traction and/or back portions.
Additionally or alternatively, in this or other embodiments the layer of material is formed from the second material.
Additionally or alternatively, in this or other embodiments the edge treatment extends partially along the traction portion.
Additionally or alternatively, in this or other embodiments the edge treatment includes an at least partially exposed tension member.
In yet another embodiment, a method of forming an elevator system belt includes arranging a plurality of tension members in a lengthwise direction and securing the plurality of tension members in a jacket by at least partially enclosing the plurality of tension members in the jacket. The jacket includes a traction portion, a back portion, and an inner portion having a greater fire resistance than the traction portion.
Additionally or alternatively, in this or other embodiments the jacket is trimmed to expose the inner portion at a lateral edge of the jacket thus forming an edge treatment having an increased fire resistance.
Additionally or alternatively, in this or other embodiments one or more fire retardant edge portions are formed, and the one or more edge portions are secured to one or more lateral edges of the jacket.
Additionally or alternatively, in this or other embodiments the one or more edge portions are preformed, and the one or more edge portions are guided into a forming tool together with the plurality of tension members. The plurality of tension members are at least partially enclosed in the jacket at the forming tool, and the one or more preformed edge portions are secured to the jacket at the forming tool.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1A is a schematic view of an exemplary embodiment of a traction elevator system;
FIG. 1B is a schematic view of another exemplary embodiment of a traction elevator system;
FIG. 1C is a schematic view of yet another embodiment of a traction elevator system;
FIG. 2 is cross-sectional view of an embodiment of a belt for a traction elevator system;
FIG. 3 is a cross-sectional view of another embodiment of a belt for a traction elevator system;
FIG. 4 is an illustration of a trimming process for an exemplary traction elevator belt;
FIG. 5 is a cross-sectional view of still another embodiment of a traction elevator belt.
FIG. 6 is a cross-sectional view of another embodiment of a traction elevator belt;
FIG. 7 is a cross-sectional view of yet another embodiment of a traction elevator belt; and
FIG. 8 is a cross-sectional view of still another embodiment of a traction elevator belt.
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION
Shown in FIGS. 1A, 1B and 1C are schematics of exemplary traction elevator systems 10 . Features of the elevator system 10 that are not required for an understanding of the present invention (such as the guide rails, safeties, etc.) are not discussed herein. The elevator system 10 includes an elevator car 12 operatively suspended or supported in a hoistway 14 with one or more belts 16 . The one or more belts 16 interact with one or more sheaves 18 to be routed around various components of the elevator system 10 . The one or more belts 16 could also be connected to a counterweight 22 , which is used to help balance the elevator system 10 and reduce the difference in belt tension on both sides of the traction sheave during operation.
The sheaves 18 each have a diameter 20 , which may be the same or different than the diameters of the other sheaves 18 in the elevator system 10 . At least one of the sheaves could be a drive sheave 26 . The drive sheave 26 is driven by a machine 24 . Movement of the drive sheave 26 by the machine 24 drives, moves and/or propels (through traction) the one or more belts 16 that are routed around the drive sheave 26 .
At least one of the sheaves 18 could be a diverter, deflector or idler sheave 18 . Diverter, deflector or idler sheaves 18 are not driven by the machine 24 , but help guide the one or more belts 16 around the various components of the elevator system 10 .
In some embodiments, the elevator system 10 could use two or more belts 16 for suspending and/or driving the elevator car 12 . In addition, the elevator system 10 could have various configurations such that either both sides of the one or more belts 16 engage the one or more sheaves 18 (such as shown in the exemplary elevator systems in FIG. 1A, 1B or 1C ) or only one side of the one or more belts 16 engages the one or more sheaves 18 .
FIG. 1A provides a 1:1 roping arrangement in which the one or more belts 16 terminate at the car 12 and counterweight 22 . FIGS. 1B and 1C provide different roping arrangements. Specifically, FIGS. 1B and 1C show that the car 12 and/or the counterweight 22 can have one or more sheaves 18 thereon engaging the one or more belts 16 and the one or more belts 16 can terminate elsewhere, typically at a structure within the hoistway 14 (such as for a machineroomless elevator system) or within the machine room (for elevator systems utilizing a machine room. The number of sheaves 18 used in the arrangement determines the specific roping ratio (e.g. the 2:1 roping ratio shown in FIGS. 1B and 1C or a different ratio). One skilled in the art will readily appreciate that the configurations of the present disclosure could be used on elevator systems other than the exemplary types shown in FIGS. 1A, 1B and 1C .
Referring to FIG. 2 , a cross-sectional view of an exemplary belt 16 is shown. The belt 16 is constructed of one or more cords 28 in a jacket 30 . The cords 28 of the belt 16 may all be identical, or some or all of the cords 28 used in the belt 16 could be different than the other cords 28 . For example, one or more of the cords 28 could have a different construction, formed from different materials, or size than the other cords 28 . As seen in FIG. 2 , the belt 16 has an aspect ratio greater than one (i.e. belt width is greater than belt thickness). Each cord 28 comprises a plurality of wires 32 , which in some embodiments are formed into strands 34 , which are then formed into the cord 28 .
The belt 16 is constructed to have sufficient flexibility when passing over the one or more sheaves 18 to provide low bending stresses, meet belt life requirements and have smooth operation, while being sufficiently strong to be capable of meeting strength requirements for suspending and/or driving the elevator car 12 .
The jacket 30 includes a traction portion 36 interactive with and contacting the drive sheave 26 and a back portion 38 opposite the traction portion 36 . Further, a width of the belt 16 is defined by edge portions 40 . An inner portion 42 of the belt 16 may be located between the traction portion 36 and the back portion 38 . The traction portion 36 and back portion 38 each have thicknesses extending across a thickness of the belt 16 so that the desired materials of the traction portion 36 and back portion 38 are present at these locations over a service life of the belt 16 .
The jacket 30 , for example, inner portion 42 , can substantially retain the cords 28 therein. The phrase substantially retain means that the jacket 30 has sufficient engagement with the cords 28 such that the cords 28 do not pull out of, detach from, and/or cut through the jacket 30 during the application on the belt 16 of a load that can be encountered during use in an elevator system 10 with, potentially, an additional factor of safety. In other words, the cords 28 remain at their original positions relative to the jacket 30 during use in an elevator system 10 . The jacket 30 could completely envelop the cords 28 (such as shown in FIG. 2 ), substantially envelop the cords 28 , or at least partially envelop the cords 28 .
The portions 36 , 38 , 40 and 42 of the jacket 30 may be formed from a number of different materials. For example, in one embodiment, the traction portion 36 is formed from a first material, for example a thermoplastic polyurethane (TPU) material. The first material has desired mechanical properties for desired traction, low noise and wear properties. Further, in embodiments of elevator systems 10 where the back surface 38 back portion 38 contacts sheaves 18 , it may be desired to form back portion 38 from the first material to provide the same mechanical properties at the back portion 38 as at the traction portion 36 .
As stated above, the inner portion 42 of the belt 16 is located between the traction portion 36 and the back portion 38 . The inner portion 42 is configured to have a degree of fire resistance greater than the traction portion 36 . The inner portion 42 may be formed from a second material, such as a material including a percentage of melamine cyanurate (MC) to increase its fire resistance relative to the traction portion 36 material. In some embodiments, the inner portion 42 is approximately 60% to 90% of a thickness 44 of the belt 16 . The material layer thickness of the traction portion 36 and/or the back portion 38 may vary in thickness. Some embodiments may include an intermediate layer 46 , for example, a fiberglass fabric or wire metal mesh between the traction portion 36 and the inner portion 42 or as a replacement for the inner portion 42 . The intermediate layer 46 may be either embedded in the belt 16 or located at the back portion 38 . The inner portion 42 and/or the intermediate layer 46 are positioned and configured to prevent burn through or melt through of the belt 16 thus leading to improved fire resistance of belt 16 , while the traditional first material is utilized at the traction portion 36 to provide the expected traction, noise level, wear rate and other properties of belt 16 operation.
Referring to FIG. 3 , in an alternate embodiment the traction portion 36 is formed from the first material, and the remaining thickness of the belt 16 , extending to the back portion 38 , is formed from the second material, the inner portion 42 extending from the traction portion 36 and extending to an defining the back portion 38 .
Referring again to FIG. 2 , embodiments may include one or more edge treatments to reduce the effect of flame spread and wraparound from the traction portion 36 to the back portion 38 , or vice versa. In the embodiment of FIG. 2 , the belt edge portion 40 are formed from the fire resistant second material, but in other embodiments may be formed from a different fire resistant material. The edge portion 40 extends inboard partially across the traction portion 36 and/or the back portion 38 . It is desired to minimize the wraparound flame spread so that the fire resistance of the edge portion 40 is maintained while minimizing the impact on performance of the traction portion 36 . In some embodiments, the edge portion 40 extends laterally inboard about 3 mm, but can vary according to desired performance.
The edge portions 40 may be formed in any one of several ways. One method of forming the edge portion 40 is illustrated in FIG. 4 . In the embodiment of FIG. 4 , the edge portion 40 is formed oversized in both thickness 50 and width 52 , and may be formed via, for example, co-extrusion with the traction portion 36 , the back portion 38 and the inner portion 42 , or may be formed via a secondary extrusion or other process. After forming, the edge portion 40 is trimmed along trim lines 54 to a selected shape to expose the fire retardant material of the edge portion 40 . The trimming operation allows for a well-defined transition area 56 between the first material of the traction portion 36 and the second material of the edge portion 40 , and ensures a selected thickness of the first material at the transition area 56 .
Referring now to FIG. 5 , in another embodiment the edge portion 40 is formed by trimming or by extruding or otherwise forming the belt 16 so that at least a portion of an end cord 28 is exposed. The metal material of the cord 28 acts as a fire resistant material to protect the belt 16 . In some embodiments, about 25% to 50% of a lateral width of the cord 28 is exposed, so the cord 28 provides fire resistance while still being securely retained in the jacket 30 . The cord cross-section for these end cords could deviate from circular and, for example, could be constructed of metallic strips or other fire resistant materials.
In other embodiments of belt 16 shown in FIGS. 6 and 7 , the edge portion 40 is pre-formed separately rather than being formed as the material flowing through the extruder screw in an extrusion process. The pre-formed edge portion 40 is then fed into the extrusion die along with the cords 18 . The preformed edge portion 40 then joined to the other jacket portions 36 , 38 , 42 of the belt 16 via a combination of adhesion and mechanical interlocking. In the embodiments of FIGS. 6 and 7 , the edge portion 40 is formed as a “C” geometry shape that achieves mechanical interlocking, but those skilled in the art will readily appreciate that edge portions 40 may be formed to other geometric shapes. In some embodiments, such as in FIG. 7 , one or more cords 18 may be positioned within an envelope of the edge portion 40 , particularly in those embodiments where edge portion 40 material has desired wear and noise performance properties. With this approach, materials with greater fire resistance can be used without the need to be processable in the extruder screw and/or at the same time as the remaining jacket material. These preformed edge portions 40 can be made by separate extrusion, machining, lamination and other continuous processes.
In another embodiment, illustrated in FIG. 8 , the edge portion 40 is located at an edge distance 60 from the end cord 28 that is at least one half of a cord diameter 58 with a maximum preferred edge distance 60 of about two cord diameters 58 so that stresses imparted to the jacket material by the cord 18 as it presses the jacket 30 against the sheave is substantially reduced.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims. | A belt for suspending and/or driving an elevator car of an elevator system includes a plurality of tension members arranged in a lengthwise direction and a jacket substantially retaining the plurality of tension members. The jacket includes a traction portion, a back portion, and an inner portion between the traction portion and the back portion. The traction portion is formed from a first material and the inner portion is formed from a second material having an increased fire resistance compared to the first material. A method of forming an elevator system belt includes arranging a plurality of tension members in a lengthwise direction and securing the plurality of tension members in a jacket by at least partially enclosing the plurality of tension members in the jacket. The jacket includes a traction portion, a back portion, and an inner portion having a greater fire resistance than the traction portion. | 3 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a Continuation application of copending U.S. Ser. No. 11/272,299 which was filed on Nov. 10, 2005, now Abandoned.
TECHNICAL FIELD
The present invention relates to estimation of disasters in infrastructures, such as computer networks.
BACKGROUND
Risk analysis predicts likelihood of disasters, such as severe failures of an Information Technology (“IT”) infrastructure, that an organization may face, and the consequences of such failures. IT disasters, such as an e-mail server failure or other computer network failure, can impact the organization's ability to operate efficiently.
Known cindynic theory (science of danger) is applicable in different domains. For example, cindynics has been used to detect industrial risks and can also be used in the area of computer network (including computer hardware and software) risks. According to the modern theory of description, a hazardous situation (cindynic situation) has been defined if the field of the “hazards study” is clearly identified by limits in time (life span), limits in space (boundaries), and limits in the participants' networks involved and by the perspective of the observer studying the system. At this stage of the known development of the sciences of hazards, the perspective can follow five main dimensions.
A first dimension comprises memory, history and statistics (a space of statistics). The first dimension consists of all the information contained in databases of large institutions constituting feedback from experience (for example, electricity of France power plants, Air France flights incidents, forest fires monitored by the Sophia Antipolis center of the Ecole des Mines de Paris, and claims data gathered by insurers and reinsurers).
A second dimension comprises representations and models drawn from the facts (a space of models). The second dimension is the scientific body of knowledge that allows computation of possible effects using physical principles, chemical principles, material resistance, propagation, contagion, explosion and geo-cindynic principles (for example, inundation, volcanic eruptions, earthquakes, landslides, tornadoes and hurricanes).
A third dimension comprises goals & objectives (a space of goals). The third dimension requires a precise definition by all the participants and networks involved in the cindynic situation of their reasons for living, acting and working. It is arduous to clearly express why participants act as they do and what motivates them. For example, there are two common objectives for risk management—“survival” and “continuity of customer (public) service”. These two objectives lead to fundamentally different cindynic attitudes. The organization, or its environment, will have to harmonize these two conflicting goals.
A fourth dimension comprises norms, laws, rules, standards, deontology, compulsory or voluntary, controls, etc. (a space of rules). The fourth dimension comprises all the normative set of rules that makes life possible in a given society. For example, socient determined a need for a traffic code when there were enough automobiles to make it impossible to rely on courtesy of each individual driver; the code is compulsory and makes driving on the road reasonably safe and predictable. The rules for behaving in society are aimed at reducing the risk of injuring other people and establishing a society. On the other hand, there are situations, in which the codification is not yet clarified. For example, skiers on the same ski-slope may have different skiing techniques and endanger each other. In addition, some skiers use equipment not necessarily compatible with the safety of others (cross country sky and mono-ski, etc.)
A fifth dimension comprises value systems (a space of values). The fifth dimension is the set of fundamental objectives and values shared by a group of individuals or other collective participants involved in a cindynic situation. For example, protection of a nation from an invader was a fundamental objective and value, and meant protection of the physical resources as well as the shared heritage or values. Protection of such values may lead the population to accept heavy sacrifices.
A number of general principles, called axioms, have been developed within cindynics. The cindynic axioms explain the emergence of dissonances and deficits.
CINDYNIC AXIOM 1—RELATIVITY: The perception of danger varies according to each participant's situation. Therefore, there is no “objective” measure of danger. This principle is the basis for the concept of situation.
CINDYNIC AXIOM 2—CONVENTION: The measures of risk (traditionally measured by the vector Frequency—Severity) depend on convention between participants.
CINDYNIC AXIOM 3—GOALS DEPENDENCY: Goals can directly impact the assessment of risks. The participants may have conflicting perceived objectives. It is essential to try to define and prioritise the goals of the various participants involved in the situation. Insufficient clarification of goals is a current pitfall in complex systems.
CINDYNIC AXIOM 4—AMBIGUITY: There is usually a lack of clarity in the five dimensions previously mentioned. A major task of prevention is to reduce these ambiguities.
CINDYNIC AXIOM 5—AMBIGUITY REDUCTION: Accidents and catastrophes are accompanied by brutal transformations in the five dimensions. The reduction of ambiguity (or contradictions) of the content of the five dimensions will happen when they are excessive. This reduction can be involuntary and brutal, resulting in an accident, or voluntary and progressive achieved through a prevention process.
CINDYNIC AXIOM 6—CRISIS: A crisis results from a tear in the social cloth. This means a dysfunction in the networks of the participants involved in a given situation. Crisis management may comprises an emergency reconstitution of networks.
CINDYNIC AXIOM 7—AGO-ANTAGONISTIC CONFLICT: Any therapy is inherently dangerous. Human actions and medications are accompanied by inherent dangers. There is always a curing aspect, reducing danger (cindynolitic), and an aggravating factor, creating new danger (cindynogenetic).
The main utility of these principles is to reduce time lost in unproductive discussions on the following subjects:
How accurate are the quantitative evaluations of catastrophes—Quantitative measures result from conventions, scales or unit of measures (axiom 2); and Negative effects of proposed prevention measures—In any action positive and negative impacts are intertwined (axiom 7).
Consequently, Risk Analysis, viewed by the cindynic theory, takes into account the frequency that the disaster appears (probability), and its real impact on the participant or organization (damage).
FIG. 1 shows a known “Farmer's” curve 9 where disasters are placed on a graph showing the relationship between probability and damage.
Disaster study is a part of Risk Analysis; its aim is to follow the disaster evolution. Damages are rated in term of cost or rate, with time. Let “d” denote the damage of a given disaster and “f” denote the frequency of such a disaster. From a quantitative point of view, it is common to define a rating “R” of the associated risk as: R=d×f. In practice, often, the perception of risk is such that the relevance given to the damaging consequences “d” is far greater than that given to its probability of occurrence f so that, the given “R=d×f” is slightly modified to: R=d k ×f with k>1. So, numerically larger values of risk are associated with larger consequences.
Disasters are normally identified by IT infrastructure components. These components follow rules or parameters and may generate log traces. Typically, disaster information is represented in the form of log files. The disaster rating and scale are relative rather than absolute. The scale may be, for example, values between “1” and “10”: “1” being a minor disaster of minimal impact to the disaster data group and “10” being a major disaster having widespread impact. The logging function depends of the needs of monitoring systems and data volumes and, in some cases, delay due to legal obligations.
The known Risk Analysis uses a simple comparison between values found by the foregoing operations, in order to extract statistics. Also, a full Risk Analysis of a IT infrastructure required a one to one analysis of all the data held on disasters. By comparing each disaster with each of the other disaster it was possible to calculate the likelihood of further disasters. This process is computationally expensive and also requires a significant amount of a computer's Random Access Memory (RAM).
An object of the present invention is to estimate risk of disaster of an infrastructure.
Another object of the present invention is to facilitate estimation of risk of disaster of an infrastructure.
SUMMARY OF THE INVENTION
The present invention is directed to a method, system and computer program for estimating risk of a future disaster of an infrastructure. Times of previous, respective disasters of the infrastructure are identified. Respective severities of the previous disasters are determined. Risk of a future disaster of the infrastructure is estimated by determining a relationship between the previous disasters, their respective severities and their respective times of occurrence.
In accordance with a feature of the present invention, the risk is estimated by generating a polynomial linking severity and time of occurrence of each of the previous disasters. The polynomial can be generated by approximating a Tchebychev polynomial.
In accordance with other features of the present invention, the risk is also estimated by modifying the polynomial by extracting peaks in a curve representing the polynomial, regenerating the polynomial using the extracted peaks and repeating the modifying step until a number of extracted peaks is less than or equal to a predetermined value.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an example of a prior art Farmer's curve.
FIG. 2 illustrates the result of the Tchebychev's polynomials approximation's use.
FIG. 3 a illustrates a polynomial curve showing the collected disaster information from a first origin.
FIG. 3 b illustrates a polynomial curve showing the collected disaster information from a second origin.
FIG. 4 illustrates the combining of the polynomial curves of FIG. 3 according to an embodiment of the invention.
FIG. 5 is a flow diagram, including a flowchart and a block diagram, illustrating a program and system for generating polynomials according to the present invention.
FIG. 6 illustrates a system according to the present invention for estimating risk of disaster of an infrastructure.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described in detail with reference to the Figures. A Tchebychev analysis program 500 (shown in FIGS. 5 and 6 ) executing in a risk estimation computer 20 generates a continuous polynomial curve with a corresponding polynomial equation. Program 500 takes derivatives of the polynomial equation. When the derivative of the continuous curve is null, the risk reaches its maximum. The construction of the polynomial equation is shown below.
For i≧1 and j≧1, a Tchebychev polynomial having “n” points is given by:
P n ( x ) = ∑ i = 1 n ( y i ∏ j = 1 n ( x - x j ) ( x i - x j ) )
For example, to calculate the polynomial between two points, Point1 and Point2, having coordinates (x 1 , y 1 ) and (x 2 , y 2 ) respectively in space (x,y), the formula is: n=2,
P 2 ( x ) = y 1 ( x - x 2 ) ( x 1 - x 2 ) + y 2 ( x - x 1 ) ( x 2 - x 1 )
Where P 2 (x 1 )=y 1 , and P 2 (x 2 )=y 2 .
To calculate the polynomial between 3 points: Point1 (x1, y1), Point2 (x2,y2) and Point3 (x3,y3), the formula is: n=3,
P 3 ( x ) = y 1 ( x - x 2 ) ( x - x 3 ) ( x 1 - x 2 ) ( x 1 - x 3 ) + y 2 ( x - x 1 ) ( x - x 3 ) ( x 2 - x 1 ) ( x 2 - x 3 ) + y 3 ( x - x 1 ) ( x - x 2 ) ( x 3 - x 1 ) ( x 3 - x 1 )
where P 3 (x 1 )=y 1 , P 3 (x 2 )=y 2 and P 3 (x 3 )=y 3 .
The Tchebychev polynomial is a continuous curve between “n” points.
Referring to FIG. 5 , Tchebychev analysis program 500 receives identified disasters data 510 from an infrastructure which are then inputted to a Tchebychev approximation module 520 . The Tchebychev module 520 calculates a polynomial from the identified disasters data 510 . The polynomial is inputted to a derivative module 530 . The derivative module 530 identifies peaks and troughs by identifying points which have a null derivative. The peaks having a null derivative are forwarded to a peaks (or tops) module 540 . The peaks module 540 identifies the peaks by studying the sign of the derivative before and after each of the identified points. Where the sign of the derivative is positive before and negative after an identified point, a peak has been found. A new filter module 550 counts the number of identified peaks and compares this to a predetermined maximum. If there are more identified peaks than the maximum, the identified peaks are inputted to the Tchebychev module 520 and the process is repeated. If the number of peaks is less than or equal to the maximum the process stops (step 560 ).
FIG. 2 illustrates an example of results produced by program 500 . An identified disasters trace 210 plots severity of a disaster against their time of occurrence. Program 500 then generates an approximation of Tchebychev's polynomials to obtain a first polynomial equation represented by a first polynomial curve 220 . Program 500 then takes derivatives of first polynomial equation 220 to identify the points at which the derivative is equal to zero. Null derivative points 230 correspond to peaks and troughs on the polynomial curve. Program 500 identifies peaks by analyzing each null derivative point 230 . If the polynomial values of the polynomial 220 before and after each null derivative point 230 are lower that the peak polynomial value at this point, a peak is identified. In this example, program 500 also identifies the extracted peaks 240 from the polynomial 220 through comparison with the identified disasters trace 210 . Where a null derivative point 230 is identified as a peak, program 500 compares the null derivative point 230 to the value of identified disasters trace 210 before and after the null derivative point 230 . Thus, program 500 identifies the extracted peaks 240 in FIG. 2 . For example, point A is one of extracted peaks 240 , B is the null derivative point 230 preceding A, and C is the null derivative point 230 following A. If the derivative is positive between A and B, and negative between A and C, point A is a peak. Furthermore, the values of the identified disasters trace 210 before and after point A are less than point A. Therefore point A is an extracted peak 240 .
Program 500 then uses an approximation of Tchebychev's polynomials to create a modified polynomial 250 using points which have been identified as peaks and the start and end point. Program 500 further modifies polynomial 250 by repeating the process described above to identify peaks. In this case, there would be no further improvement but in other cases the process will preserve only the highest peaks.
Referring now to FIGS. 3 a and 3 b , polynomial curves 340 a and 340 b show two collections of disaster information for two organizations (called “first origin” and “second origin”) with each disaster 310 a and 310 b shown as a point (resembling a small circle) on the respective polynomial curve 340 a and 340 b . Program 500 identifies represented peaks 320 a and 230 b (shown as starts) by the process described above to identify peaks from recovered data points. Each polynomial curve 340 a and 340 b has respective ends 330 a and 330 b (shown as triangles).
Referring now to FIG. 4 , the polynomial curves 450 a and 450 b represent the two polynomial curves 340 a and 340 b respectively, of FIGS. 3 a and 3 b ( 340 ). The first origin of curve 450 a has disaster points 420 (represented by the number “2” in a circle) and the second origin of curve 450 b has disaster points 430 (represented by the number “1” in a circle). Program 500 identifies peaks and ends of each of the polynomial curves 450 a and 450 b , and extracts represented peaks. The new ends 440 are the ends from either of the polynomial curves 450 a or 450 b which are of greater gravity or greater extremity of time. Program 500 then uses the represented peaks from each polynomial curve 450 a or 450 b along with the new ends 440 to generate a merged polynomial 460 which represents disaster from the combined information of the first and second origin.
Referring now to FIG. 6 , a data logger 602 which enables information, typically consisting of logged events, to be collected from a infrastructure network 604 . The information from the data logger 602 is stored in a data storage 606 . A disaster identification program 608 assesses the logged events to determine whether the event is deemed a disaster. For example, if the logged event indicates a failure of system hardware or software it may be logged as a disaster. A disaster gravity program 610 assesses each identified disaster generating disaster data. For example, as described previously, a disaster may be assigned a value between “1” and “10” corresponding to level of impact on the infrastructure 604 . The disaster data is then inputted to Tchebychev analysis program 500 as described previously. The Tchebychev analysis program generates a risk analysis equation or data. Program 500 then analyzes the risk analysis data to identify one or more high risk disaster events. For example, after the Tchebychev analysis program 500 has completed the risk analysis, program 500 typically identifies a number of peaks corresponding to high risk events 612 . These peaks/events can be identified as disasters which generate significant risk to the infrastructure 604 . Measures can then be automatically, or otherwise, taken to minimise further risk. For example, the computer system 20 could instigate additional services on other computers or server of the network 604 to provide additional redundancy to cope with a particular high risk event. The high risk events 612 can also be displayed on a computer screen, or any type of visual display unit, to allow a user to view and obtain more information about the high risk events 612 . In this manner, a disaster of greatest potential risk can be identified automatically.
The present invention may be embodied in a computer program (including program modules 608 , 610 , 500 and 612 ) comprising instructions which, when executed in computer 20 , perform the functions of the system or method as described above. The computer 20 includes a standard CPU 12 , operating system 14 , RAM 16 and ROM 18 . The program modules 608 , 610 , 500 and 612 are stored on computer readable disk storage 606 for execution by CPU 12 via computer readable memory 16 . The program modules 608 , 610 , 500 and 612 can be loaded into computer 20 from a computer-readable storage device such as a magnetic disk or tape, optical device or DVD, or alternatively downloaded via network 604 via a TCP/IP adapter card 21 .
Improvements and modifications may be incorporated without departing from the scope of the present invention. | Method, system and computer program for estimating risk of a future disaster of an infrastructure. Times of previous, respective disasters of the infrastructure are identified. Respective severities of the previous disasters are determined. Risk of a future disaster of the infrastructure is estimated by determining a relationship between the previous disasters, their respective severities and their respective times of occurrence. The risk can be estimated by generating a polynomial linking severity and time of occurrence of each of the previous disasters. The polynomial can be generated by approximating a Tchebychev polynomial. | 6 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an electronic device comprising an electronic element which generates heat during operation and another electronic element to be used under an ambient temperature lower than a temperature caused by heat irradiated from the heat generating element.
[0002] As a prior art, for example, there is proposed a support structure in JP-A-11-249214, which comprises a support plate on one side surface of which a circuit board is mounted and the other side surface of which a structural body sensitive to heat is mounted, wherein the support plate is composed of two metal plates, having different thermal conductivities from each other, which are arranged so as to oppose to each other and electrically connected with each other, and wherein the circuit board is mounted on one side of the higher conductivity plate opposite to the other side facing the lower conductivity plate and the structural body is mounted on one side of the lower conductivity plate opposite to the other side facing the higher conductivity plate.
SUMMARY OF THE INVENTION
[0003] In the prior art construction, some distance is retained between the circuit board and the structural body. However, there is a need that desirably the distance between the circuit board and the structural body is as small as possible.
[0004] In the prior art construction, further there is a need that the metal plate having higher thermal conductivity has to possess enough strength in order to mount the circuit board thereon. Therefore, the metal plate having higher thermal conductivity has to be produced from a specific restricted material.
[0005] In the prior art construction, there is a problem that the metal plate having higher conductivity is required to be thick.
[0006] In the prior art construction, there is also a problem that a heat dissipating part of the electronic device becomes a higher temperature than that of the other remaining parts of the electronic device.
[0007] Thus, an object of the present invention is to solve the above problems.
[0008] Another object of the present invention is to downsize electronic devices.
[0009] Under the above objects, according to the present invention, there is provided an electronic device comprising an electronic element which generates heat during operation and another electronic element to be used under an ambient temperature lower than a temperature caused by heat irradiated from the heat generating element, wherein the electronic device comprises a support means to support a housing of the electronic device, and a heat conducting means being arranged between the support means and the heat generating element to conduct heat irradiated from the heat generating element.
[0010] Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a exploded perspective view showing components of a DVD camera according to the invention;
[0012] [0012]FIG. 2 is a perspective view of an assembly of a heat conducting member and a frame according to the invention;
[0013] [0013]FIG. 3 is a front view of the assembly of the heat conducting member and the frame according to the invention;
[0014] [0014]FIG. 4 is a longitudinal cross-sectional view of the part including a laser of the DVD camera according to the invention;
[0015] [0015]FIG. 5 is a longitudinal cross-sectional view of the DVD camera according to the invention;
[0016] [0016]FIG. 6 is a partial enlargement of FIG. 5 as indicated by arrow VI, which shows around a tripod piece;
[0017] [0017]FIG. 7A is a transverse cross-sectional view of the DVD camera according to the invention;
[0018] [0018]FIG. 7B is a partial enlargement of FIG. 7A as indicated by arrow 7 B;
[0019] [0019]FIG. 8A shows the heat conducting member and the frame assembled with each other;
[0020] [0020]FIG. 8B is a cross-sectional view taken along the line indicated by arrows 8 B- 8 B, which shows joints of the both members;
[0021] [0021]FIG. 9A an enlargement of the cross-section of one of the joints shown in FIG. 8B;
[0022] [0022]FIG. 9B shows a state of the joint in fabrication process of the heat conducting member and the frame, which corresponds to FIG. 9A; and
[0023] [0023]FIG. 10 shows a second embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Herein below preferred embodiments will be described.
[0025] In the preferred embodiments, the electronic device is a DVD camera, a component mounted on a board generates heat during operation, and a laser to read/write data on a DVD is an electronic component having a maximum operational temperature lower than that elevated by the heat generating component mounted on the board. The invention, however, is not limited to this application and can be incorporated in other electronic devices comprising an electronic element which generates heat during operation and another element having a maximum operational temperature lower than that elevated by the heat generating element including, but are not limited to, video tape cameras, HDD cameras, memory cameras, optomagnetic disk cameras, data read/write devices and the like.
[0026] [0026]FIG. 1 is an exploded perspective view showing a component arrangement of a DVD camera embodying the present invention. Referring to FIG. 1, major components of the DVD camera will be described. A frame 1 and a heat conducting member 2 fixed to the frame 1 are disposed between a right case 5 and a board A 3 juxtaposing a board 4 outside the board 3 . The assembly is further covered with a front case 8 , a cover 9 , a rear case 6 , and a left case 7 for completion.
[0027] A disk drive for an optical disk is fabricated in the right case 5 , and a laser of an optical pick-up device in the disk drive is an element sensitive to elevated temperatures. The board 3 carries an element which generates heat during operation. An arrangement is made such that heat generated by the element on the board 3 is conducted effectively to outer members via the heat conducting member 2 . Furthermore, the heat conducting member 2 is arranged so as to be apart from the laser of the disk drive. More specifically, an arrangement to secure prescribed distances between the laser and the heat generating element in three dimensions (straight distance from laser) and shorten the space between the disk drive and the heat conducting member 2 enables the reduction in thickness of the DVD camera. Details of this feature will hereinafter be described in order.
[0028] Referring to FIG. 2 showing a perspective view of an assembly of the heat conducting member 2 and the frame 1 , a configuration of the heat conducting member 2 will be described. The heat conducting member 2 is jointly fixed onto the frame 1 to dispense with a specific mounting member between the heat conducting member 2 and the frame 1 . The joining methods will be described later with reference to FIGS. 8 and 9.
[0029] On the heat conducting member 2 , a heat conducting part a 2 a, a heat conducting part 2 b, and a heat conducting part 2 c to conduct heat to the outer members are disposed. By means of the three heat conducting parts a 2 a, b 2 b, 2 c on the heat conducting member 2 , internal heat created by the board 3 and the like can be conducted efficiently to the outer members. If the heat conducting parts are disposed at locations most unlikely to contact with users' hands, users may feel comfortable in operating the electronic devices. The structure for conducting internal heat to the outer members will be described with reference to FIGS. 5, 6, and 7 .
[0030] Referring to FIG. 3 illustrating a front view of the assembly of the heat conducting member 2 and the frame 1 , a positional relationship between the heat generating area and the laser of the disk drive will be described. The board A 3 (not shown) is disposed on the front side in FIG. 3 and the heat generating element is located in an encircled area denoted a heat generating area 3 a of board 3 . The disk drive 11 is disposed on the back side in FIG. 3 and the laser sensitive to elevated temperatures is located in a dotted circle denoted a laser position 31 a.
[0031] It is configured such that no part of the heat conducting member 2 is disposed around the laser position 31 a, namely the area sensitive to heat (laser) 11 a. On the other hand, the heat conducting member 2 is placed over the board A heat generating area 3 a.
[0032] As the temperature of the heat conducting member 2 is elevated during operation of the electronic device, the laser is arranged so as to be apart from the heat conducting member 2 to minimize a rise in temperature of the laser due to heat radiation from the heat conducting member 2 . More specifically, it is arranged that the laser is spaced predetermined distances, dimensions A 1 and A 2 , apart from the heat conducting member 2 to minimize an increase in the temperature of the laser.
[0033] The positional relationship between the laser and the heat conducting member 2 will further be described later with reference to FIG. 4. A structure to conduct heat of the board A heat generating area 3 a to the heat conducting member 2 will also be explained later with reference to FIG. 5.
[0034] In the preferred embodiments, a stainless steel plate is adopted to fabricate the frame 1 . Stainless steel permits the use of a thin plate providing sufficient strength and helps reduce weight of the electronic device. For the fabrication of the heat conducting member a copper plate is adopted. With its high thermal conductivity and superior machining properties, even a thin copper plate gives rise to an adequate heat conducting effect and copper is easy to be processed into various forms.
[0035] While it has been described in the preferred embodiments that the material of the frame 1 is stainless steel and that of the heat conducting member 2 is copper, the materials for the frame 1 and the heat conducting member 2 are not limited. As the heat conducting member 2 according to the invention is not required to support such structural members as a board and the like, a non-metal material like graphite can also be used.
[0036] [0036]FIG. 4 is a longitudinal cross-sectional view of the part including the laser of the DVD camera. Referring simultaneously to FIGS. 4 and 3 the arrangement of the laser 31 and the heat conducting member 2 is described. From the view point of temperature control the straight distance between the laser 31 and the heat conducting member 2 may preferably be large enough, however, to reduce thickness of the DVD camera the dimension B is required to be small enough. Therefore, the embodiments of the present invention adopt a configuration of the heat conducting member 2 with a cut away area such that the laser 31 and the heat conducting member 2 are spaced dimensions A 1 and A 2 in FIG. 3 apart each other. This configuration helps minimize a thermal effect over the laser 31 resulting from heat radiation from the heat conducting member 2 which may be prominent if the dimension B is reduced and materialize thin DVD cameras.
[0037] Referring to FIG. 5 showing a longitudinal cross-sectional view of the DVD camera, the arrangement of the disc drive 11 , the board 3 , and the heat conducting member 2 will be described. The frame 1 carrying the heat conducting member 2 fixed thereto is mounted on the right case 5 and then the board 3 and the board 4 are fixed to the frame 1 . The disk drive 11 is assembled in the right case 5 .
[0038] Between the heat conducting member 2 and the board 3 heat radiation rubber 20 having a high thermal conductivity is disposed to efficiently conduct heat of the heat generating element on the board 3 to the heat conducting member 2 . Furthermore, the heat conducting part a 2 a is disposed in contact with the cover 9 and similarly the heat conducting part 2 b is disposed in contact with the tripod piece 10 such that heat inside the DVD camera is conducted to the outer members including the cover 9 and the tripod piece 10 for dissipation to outside.
[0039] Referring to FIG. 6 showing a detail around the tripod piece 10 , the arrangement of the tripod piece 10 and the heat conducting part 2 b will be described. The heat conducting part 2 b contacts with the tripod piece 10 , one of the outer members, and is configured so as to be interposed therebetween in assembling to efficiently dissipate heat of the heat conducting member 2 to outside by means of the heat conducting part 2 b and the tripod piece 10 .
[0040] [0040]FIG. 7A shows a transverse section of the DVD camera and FIG. 7B shows a detail thereof. Referring to FIGS. 7A and 7B, the arrangement of the rear case 6 and the heat conducting part 2 c will be described. The heat conducting part 2 c contacts with the rear case 6 , one of the outer members, and is provided with heat radiation rubber B 21 having a high thermal conductivity in its recess. It is configured therebetween such that the heat radiation rubber 21 is interposed in assembling for efficient dissipation of heat of the heat conducting member 2 to outside by means of the heat conducting part 2 c and the rear case 6 . On the other hand, no heat radiation rubber is disposed on the heat conducting parts 2 a and 2 b to allow fabrication of the assembly of the central members into the casing of the DVD camera in the direction as indicated by the arrow in FIG. 2. Under the foregoing construction if heat radiation rubber pieces are disposed on the heat conducting parts 2 a and 2 b, such rubber pieces may be twisted in assembling the central members. Therefore, the heat radiation rubber is disposed only on the heat conducting part 2 c facing the rear case 6 .
[0041] Referring now simultaneously to FIGS. 8A and 8B and FIGS. 9A and 9B, joining methods between the heat conducting member 2 and the frame 1 will be described. FIG. 8A is a front view of the assembly of the heat conducting member 2 and the frame 1 , FIG. 8B a section of the joining parts thereof, FIG. 9B a detailed view of one of the joining parts prior to connection, and FIG. 9A a detailed view of the joining part after connection.
[0042] A section taken along the line 8 B- 8 B including the joining parts in FIG. 8A is FIG. 8B, wherein two joining parts are included. A frame bar ring 1 d having a projection like a grommet is inserted into a heat conducting member hole 2 d (refer to FIG. 9B) and then the top of the frame bar ring 1 d is broken down into a frame caulking 1 e to fix the heat conducting member 2 onto the frame 1 (refer to FIG. 9A). In the preferred embodiments a plurality of the joining parts are provided.
[0043] The method for joining the heat conducting member 2 and the frame 1 is not limited to the foregoing example and other methods including, but are not limited to, adhesion, bolting, welding and the like may be adopted.
[0044] Referring now to FIG. 10, a second embodiment will be described. In the first embodiment, the frame 1 has been described as a single plate. In the second embodiment, however, the frame 1 consists of a first frame 1 A and a second frame 1 B as shown in FIG. 10. Even in a same model of cameras there is a case where different type of taking lenses is adopted. When this is the case, as is shown in FIG. 10 a frame part associated with lenses is separated into a second frame, and the second frame alone may be changed corresponding to the type of lenses for manufacture of the DVD camera while maintaining the first frame unchanged.
[0045] In other words, the second frame includes two different second frames and depending on the type of lenses either one of the second frames will be used.
[0046] By separating the frame into the first frame and the second frame, manufacture of frames will be facilitated and the production costs will be reduced.
[0047] As described heretofore, according to the present invention electronic devices can be reduced in their sizes.
[0048] It should be further understood by those skilled in the art that although the foregoing description has been made on embodiments of the invention, the invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims. | Disclosed is an electronic device comprising an electronic element which generates heat during operation and another electronic element to be used under an ambient temperature lower than a temperature caused by heat irradiated from the heat generating element, wherein the electronic device comprises a support means to support a housing of the electronic device, and a heat conducting means being arranged between the support means and the heat generating element to conduct heat irradiated from the heat generating element. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to an intracranial pressure relief valve and, more particularly, to a simplified valve construction including coaxially aligned valve part members which establish three stage valve operation to provide either constant pressure or constant flow characteristics in accordance with a fluid pressure differential applied across the valve.
Hydrocephalus is a condition in which the body, for any one of a variety of reasons, is unable to relieve itself of excess cerebrospinal fluid (CSF) collected in the ventricles resulting in an abnormal increase in both epidural and intradural pressures. This in turn may cause a number of adverse physiological effects including compression of brain tissue, impairment of blood flow in the brain tissue and impairment of the brain's normal metabolism.
Treatment of a hydrocephalic condition frequently involves relieving the abnormally high intracranial pressure. Accordingly, a variety of CSF pressure regulator valves and methods of controlling CSF pressure have been developed which include various check valves, servo valves or combinations thereof. Generally, such valves serve to divert CSF from the ventricles of the brain through a discharge line to some suitable drainage location in the body such as the venous system of the peritoneal cavity. Check valves operate by opening when the difference between CSF pressure and pressure in the discharge line exceeds a predetermined value.
The use of a simple check valve can be advantageous with respect to minimizing the cost of the valve, but with nothing more than check valve operation, the treatment of hydrocephalus is potentially disadvantageous since it is possible for such valve to open in response to a sudden, but nevertheless perfectly normal, increase in differential pressure between CSF in the ventricular spaces and fluid at the selected discharge location of the body, resulting in abnormal and potentially dangerous hyperdrainage of the ventricular spaces. For example, when a patient stands after lying in a recumbent position, resulting increased vertical height of the fluid column existing between the head and the selected drainage location may result in such an increase in differential pressure. Accordingly, valves, such as that described in the copending application of the present inventor, Ser. No. 672,868, filed Nov. 19, 1984, have been developed which serve to prevent undesired hyperdrainage by limiting the flow rate of fluid through the valve when a sudden increase in differential pressure occurs.
In this valve, a diaphragm, movable in response to the pressure differential between ventricular CSF pressure and pressure of fluids at the drainage location of the body, was mechanically coupled to a valve seat having a fluid metering orifice extending therethrough. The orifice allowed passage of CSF from the ventricular spaces to the selected drainage location. Motion of the diaphragm in response to change in the differential pressure caused the valve seat to be moved from a first position, in which the valve seat contacted a suitably located sphere to block and thereby prevent the passage of fluid through the orifice, to a second position, in which a generally cylindrical fluid flow restrictor partially occluded the orifice, thereby limiting fluid flow therethrough. By controlling the position of the sphere, the valve seat and the restrictor, it was possible to construct a valve having flow characteristics which avoided hyperdrainage with sudden changes in differential pressure.
As valves of this type are miniaturized, the number of parts involved, the complexity of the configurations of the various parts and the cost of generating the same become major factors. Working tolerances involved are on the order of 0.001 of an inch and continuing efforts are being made to reduce manufacturing costs while maintaining rather complex effective functioning.
The present invention is directed to an improvement in such a valve wherein the more standard types of valve elements or parts are utilized, the accumulated knowledge available in the manufacture of such parts being relied upon to reduce the cost of the valve. Basically, the preferred form of valve constructed in accordance with the present invention utilizes a sphere spring held against a valve seat somewhat similar to the well known type of check valve, the flow characteristics of the valve in response to variations in differential pressure being controlled by a restrictor element of simplified construction and cooperating with the check valve sphere in a unique manner to effectively provide the various modes of operation in the treatment of hydrocephalus.
In view of the foregoing, it is a general object of the present invention to provide a new and improved pressure regulator valve for relieving intracranial pressure caused by the presence of excess CSF in the ventricles of the brain.
It is a more specific object of the present invention to provide a pressure regulator valve which includes components which may be easily and economically manufactured.
It is a still more specific object of the present invention to provide a pressure regulator valve in which critically dimensioned components are of an easily manufactured configuration.
SUMMARY OF THE INVENTION
The invention is directed to a valve for controlling the passage of body fluids from one location in the body to another location. The valve includes a housing having first and second interior chamber areas. An inlet port establishes fluid communication between the first chamber area and the one location, while an outlet port establishes fluid communication between the second chamber area and the other location. A valve mechanism, including a series of coaxially aligned parts having a valve seat, valve seat closure means, fluid flow restrictor means and positioning means acting on the valve seat closure means, is actuable to a first condition in which fluid communication between the first and second chamber areas is prevented. The valve mechanism is also actuable to a second condition in which fluid communication is provided between the first and second chamber areas at a flow rate sufficient to maintain a substantially constant desired first pressure in the first chamber area, and to a third condition in which fluid communication is provided between the first and second chamber areas sufficient to maintain a desired substantially constant fluid flow rate. Finally, the valve mechanism is actuable to a fourth condition in which fluid communication is provided between the first and second chamber areas sufficient to maintain a substantially constant desired second pressure in the first chamber area. Thus, the valve sequentially prevents the passage of fluid between the one location and the other location, maintains a constant fluid pressure differential between the one location and the other location, maintains a desired constant rate of flow of fluid between the one location and the other location, and maintains a second constant desired fluid pressure differential between the one location and the other location.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with the further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, in the several figures of which like reference numerals identify like elements, and in which:
FIG. 1 is a perspective view, partially in section, of a CSF pressure relief system employing a three stage pressure regulator valve constructed in accordance with the present invention, showing such a system implanted within a patient.
FIG. 2 is an elevational view of the pressure regulator valve.
FIG. 3 is a cross-sectional view of the pressure regulator valve taken along line 3--3 of FIG. 2.
FIG. 4 is an enlarged cross-sectional view of the valve showing a section thereof and operation of the valve in a first constant pressure mode.
FIG. 5 is a cross-sectional view, similar to FIG. 4, showing the pressure relief valve in a constant flow rate mode.
FIG. 6 is a cross-sectional view, similar to FIG. 4, showing the pressure relief valve in a second constant pressure mode.
FIG. 7 is a graphical depiction of certain pressure and flow characteristics of the three stage pressure relief valve useful in understanding the operation thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, and particularly to FIGS. 1 and 2, a CSF pressure relief system 10 for maintaining a desired predetermined intracranial pressure in a patient 11 is illustrated. The system shown includes a three stage pressure relief valve 12 constructed in accordance with the present invention for maintaining the desired intracranial pressure.
Cerebrospinal fluid (CSF) 14 is drained from a ventricle 15 of the brain 16 by means of a ventricular catheter 17. Preferably, the catheter is radio-opaque in order to facilitate its accurate placement within the brain. The distal end 18 of the catheter may be provided with a plurality of apertures 20 (FIG. 2) for allowing the passage of CSF therethrough and is positioned in a suitable brain ventricle 15. The other end of the catheter is coupled to the inlet port 21 of the valve to establish fluid communication between the valve and the ventricle. The outlet port 22 of the valve is attached to one end of a drain catheter 23, the opposite end of which discharges into an appropriate location in the patient's body. Although the drain catheter is shown threaded through an appropriate vein 24 to terminate within the right atrium of the heart 25, a different drainage location, such as, for example, the peritoneal cavity, could be selected instead. When open, pressure relief valve 12 allows passage of CSF from the brain ventricle to the selected discharge location to relieve excessive intracranial pressure caused by excessive accumulation of CSF.
While an increased differential pressure may result from the excessive accumulation of CSF in the brain ventricle, such an increase might also be a perfectly normal response to ordinary physical cavity of the patient. For example, when a patient stands after lying for some time in a recumbent position, as illustrated in phantom of FIG. 1, the differential pressure will suddenly increase by reason of the sudden increase in vertical height H of the fluid column existing between the distal end of the ventricular catheter 17 and the drainage location. If the relief valve were to open and permit unrestrained fluid flow in response to this pressure increase, hyperdrainage of the ventricle, and a brain hematoma, are possible results. Accordingly, the valve includes means for preventing such unrestricted fluid flow to the drainage location in the event of a sudden increase in the differential pressure.
The construction of the three stage valve may best be understood by reference to FIGS. 2 and 3. As illustrated, the valve includes a tubular housing 26 fashioned from a durable, biologically compatible material, such as thermoplastic polymers of polyethersulfone or polycarbonates. The dimensions of the housing 26 are selected so as to be compatible with subcutaneous implantation of the valve over the cranium 27 (FIG. 1).
The housing 26 includes at opposite ends thereof frusto-conically shaped housing end members 28 and 29, which interiorly define chamber areas 30 and 31, respectively. Fluid flow through the valve is illustrated by the arrows forming apart of FIG. 3, the catheter 17 being attached to the inlet port 21 defined by the housing end member 28, and the catheter 23 being attached to the outlet port 22 defined by the housing end member 29.
Referring to FIG. 3, the interior of the housing 26 includes a pair of longitudinally spaced valve assemblies which are of identical construction. Each valve assembly includes a valve housing 32 formed from any suitable material such as stainless steel. At the inflow end of each valve assembly the housing is shaped to form a valve seat internally thereof, such seat being defined by the internal frusto-conical surface 33 which converges toward the inflow end of the housing and terminates in an annular orifice 34 defined by a flat inner surface. The divergent end of the seat 33 merges with an annular inner surface 35 of the valve housing 32, this inner surface being interrupted rearwardly of the valve seat in the direction of fluid flow by an inwardly projecting, annular fluid flow restrictor 36. The end of the valve housing 32 which defines the outlet end thereof is provided with an annular wall portion 37 or spring retainer having a centrally located fluid discharge orifice 38 therein. This end wall portion along the inner surface thereof surrounding the discharge orifice 38 establishes a seat for the adjacent end of a coil spring 39 which extends coaxially and centrally of the valve housing 32, through the restrictor ring 36 and into engagement with a valve seat closure member 40 which is in the form of a ball or sphere. The spring 39 is confined between the end wall portion 37 of the valve housing 32, this end wall portion functioning as a spring retainer, and the check valve sphere 40 which, in the absence of a predetermined fluid differential pressure, is held by the spring 39 in engagement with the valve seat 33 so as to occlude the fluid flow orifice 34.
The sphere 40 is highly polished and may be fabricated from synthetic sapphire. The spring 39 may be formed from stainless steel and is pre-calibrated so that the valve assembly will function in the manner to be described. The restrictor ring 36 is dimensioned to permit the spring and ball to move therethrough as will be described, the clearance being on the order of approximately 0.001 of an inch. Thus, the lumen of the valve housing 32 is restricted to a predetermined extend by the inwardly projecting annular ridge or ledge defining the restrictor 36.
While FIG. 3 illustrates the use of a pair of identical valve assemblies in the primary housing 26, it will be understood that single valve assembly may be utilized. Each of the valve assemblies illustrated in the embodiment of FIG. 3 functions is precisely the same manner as will be described. Briefly, the fluid discharge of the right hand valve assembly in FIG. 3 will exert the same pressure differential against the left hand valve assembly in FIG. 3, thus resulting in the same amount of fluid discharge therefrom. The provision of a pair of valve assemblies in the single main housing permits the total system to be tested after implantation. Pressure exerted on various points in the system, such as between the two valve assemblies of FIG. 3, can assist in determining whether blockage has occurred. To facilitate this testing, the primary housing 26 is flexible to some extent thereby permitting pressure to be applied to the housing between the valve assemblies after the system has been implanted. Application of appropriate pressure against the housing 26 between the valve assemblies will result in testing both valve assemblies. For example, depression of the central portion of the housing will increase the fluid pressure acting against the left hand valve assembly and will cause additional fluid flow therethrough. If by chance the right hand assembly is clogged to an extent that complete closure of the assembly is prevented, the centrally exerted pressure as described can assist in establishing this fact.
The various modes of operation of the three stage valve have been referred to hereinabove. FIG. 7 illustrates these modes. Basically, the pressure relief valve 12 normally operates to maintain a predetermined differential pressure P 1 between fluid in the brain ventricle and at the selected discharge location of the body. The valve accomplishes this by adjusting the fluid flow rate Q so that the pressure P 1 is maintained. This operation of the valve is shown in region I of FIG. 7.
When differential pressure rapidly increases, such as when the patient stands, a flow rate greater than a preselected rate Q 1 is necessary to maintain pressure P 1 . However, such a flow rate may create the risk of undesirable hyperdrainage of the brain ventricle. Accordingly, when a rapid increase in differential pressure occurs, the valve automatically serves to maintain a relatively constant desired rate of fluid flow despite changes in differential pressure, as depicted in region II of FIG. 7. In a practical valve, the flow rate will not be entirely independent of the applied differential pressure but rather will increase from a lower flow rate Q 1 to a higher flow rate Q 2 as differential pressure increases between first pressure P 1 and a second pressure P 2 , as indicated by the solid line in FIG. 7. Flow rates Q 1 and Q 2 are sufficiently low so that during a temporary rapid increase in differential pressure, pressure will return to normal before a quantity of CSF sufficient to cause adverse side effects may flow through the valve. In a typical valve Q 1 and Q 2 might be 0.4 ml./min. and 0.8 ml./min., respectively, while first and second pressures, P 1 and P 2 , may have values of 80 and 350 millimeters of water, respectively.
While it is desirable to avoid high flow rates through the valve in order to avoid hyperdrainage of the ventricle, it may, under certain emergency conditions, be desirable to allow rapid shunting of CSF in order to avoid possible brain damage. When the valve is operating in region II, increases in differential pressure tend to close the valve. To avoid the possibility of building extremely high ventricular CSF pressure, the valve is constructed so that when differential pressure exceeds a predetermined pressure P 2 substantially higher than pressure P 1 , the valve once again operates to allow a fluid flow rate sufficient to maintain a differential pressure no higher than pressure P 2 . This operation is depicted in region III of FIG. 7. When the valve is operating in this region, further increases in differential pressure result in an increase in fluid flow through the valve thereby stabilizing differential pressure.
FIGS. 3 through 6 illustrate the four different conditions of fluid flow and/or valve assembly operation. Operation of a single valve assembly is illustrated in FIGS. 4 through 6. FIG. 3 shows the valve assembly in the first condition wherein fluid flow is prevented such as when differential pressure is negative or non-existent. As urged by the spring 39, the valve seat closure member 40 engages the frusto-conical ramp surface 33 of the valve seat and the fluid flow orifice 34 is completely closed. CSF fluid flow between chamber areas 30 and 31 is prevented.
When the differential pressure is relatively low, such as when the valve is operating in region I of FIG. 7, the resulting slight pressure is sufficient to displace the valve seat closure member 40 from the valve seat ramp 33 thereby allowing CSF to pass through the orifice 34 as shown in FIG. 4. The lumen of the restrictor 36 is sufficiently removed from the ball member 40 so as not be interfere with the flow of CSF between the chamber areas. Thus, the valve acts primarily as a constant pressure device whereby the pressure differential P 1 is maintained between the CSF in the chamber areas 30 and 31. A slight increase in differential pressure results in further movement of the ball member 40 against the action of the spring 39 thereby further opening the orifice 34 to allow greater CSF flow between the chamber areas. Similarly, a decrease in pressure allows the ball member 40 to move toward the valve seat ramp 33 restricting flow between the chamber areas and causing pressure in the chamber area 30 to increase.
FIG. 5 illustrates the operation of the valve when a sudden increase in differential pressure is applied to the valve. When such an event occurs, the pressure differential exceeds the predetermined regulated pressure P 1 and the valve operates in region II of FIG. 7. The displacement of the ball member 40 is now sufficient to bring the same into close association with the restrictor ring 36 so as to cause the ball member to move within the ring. Under these circumstances, the restrictor functions to partially occlude the fluid flow area within the valve housing 32. This increasing occlusion occurring by reason of increasing differential pressure is sufficient to offset the higher flow rate ordinarily resulting from increased pressure, resulting in a relatively uniform rate of fluid flow between the chamber areas despite such an increase in differential pressure. Accordingly, in this condition, the valve acts primarily as a constant flow device permitting the passage of fluid from chamber area 30 to chamber area 31 at a relatively constant predetermined rate despite changes in applied differential pressure.
FIG. 6 illustrates the operation of the valve in region III of FIG. 7, such as would occur when the differential pressure exceeds a predetermined pressure P 2 . In this condition, differential pressure displaces the ball member 40 beyond the restrictor ring 36 so as to allow CSF to flow through the restrictor ring more readily by reason of reducing occlusion of the ring. The fluid flow area within the valve housing 32 is now less restricted than in region II. When the valve is operating in this manner, increases in differential pressure cause further opening of the valve and allows a greater fluid flow rate. Thus, the valve operates essentially as a constant pressure device whereby differential pressure greater than the predetermined maximum pressure P 2 is prevented.
The design of the valve mechanism of the present invention readily lends itself to miniaturization. The simplicity of construction enhances its usefulness while maintaining manufacturing cost at a minimum. Assembly of the valve is uncomplicated. These advantages plus the fact that the valve automatically provides control over multiple conditions of operation establishes the significance of the present invention.
While a particular embodiment of the invention has been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made therein without departing from the invention in its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. | An implantable valve for allowing the passage of cerebrospinal fluid (CSF) from a ventricle of the brain to a suitable drainage location in the body includes a housing having an inlet and outlet with valving means in the housing to control fluid flow from the inlet to the outlet. The valving means includes various parts which are coaxially aligned between the inlet and outlet, the valving means having a valve seat, a valve closure means, a fluid flow restrictor means and a positioning means to control variable positioning of the valve closure means relative to the parts of the valving means. The valving means is actuable in response to applied pressure differentials, and regulates passage of CSF from the ventricular spaces to the drainage location. When the pressure differential is relatively small, the valve operates in a constant pressure mode to maintain a predetermined pressure differential across the valve. In response to a sudden increase in differential pressure, the valve operates in a constant flow mode to maintain a desired relatively constant CSF flow rate through the valve. Above a predetermined pressure differential, the valve operates in a constant pressure mode to maintain a predetermined maximum pressure differential across the valve. | 8 |
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
The U.S. Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of Contract No. DE-AC05-00OR22725 awarded by the U.S. Department of Energy to UT-Battelle, LLC.
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
FIELD OF THE INVENTION
The present invention relates to the modification of organic and inorganic fibers using plasma technology and microwave radiation. More specifically, the present invention relates to a method for producing an undulated surface on reinforcement fibers using microwave radiation and a non-uniform plasma energy.
BACKGROUND OF THE INVENTION
Advanced structural composites are reinforced polymers constructed using a matrix material and one or more reinforcement elements, such as fibers, filaments, or elongated particles. They are generally lightweight and possess superior strength and elasticity over most metals, and are often used as structural members in the aerospace industry and in high-tech space applications. Advanced structural composites are also used in other broader commercial applications where low weight and high mechanical strength materials are required, such as tennis rackets, fishing poles and golf clubs.
In general, the mechanical properties of the composite depend primarily upon the reinforcement elements selected and their ability to interact with the matrix material, usually a polymeric resin. The intrinsic mechanical properties of these two constituents are very different and, therefore, each constituent serves a different function. The function of the matrix material is to bind the reinforcement elements together to form a coherent structure, and to provide a medium for transferring applied loads from one element to another. The matrix material also provides the composite with its high temperature mechanical properties, transverse strength and moisture resistance, and is a key factor in providing toughness, shear strength, and oxidation and radiation resistance. The matrix material also strongly influences the fabrication process and the associated parameters for forming intermediate and final products from the composite material.
The reinforcement constituent, on the other hand, functions as the composite's load-bearing element. This is because the strength of the reinforcement material is generally many orders of magnitude greater than the matrix material. As a result, the matrix resin can generally tolerate higher levels of deformation than the reinforcement material. This higher tolerance allows the matrix system to distribute applied loads from one reinforcement element to another. For this reason, good bonds between the reinforcement elements and the matrix resin are extremely important for composites subjected to loads, particularly shear-critical loads.
If fibers are selected as the reinforcement element, a broad spectrum of fibers with variable mechanical properties can be used. For example, one commonly used fiber is the carbon fiber. Carbon fibers have a very high strength and/or stiffness when compared to polymeric resins. Other fibers include fibers made of glass, nylon, rayon, cellulose, aramide, polyethylene, polypropylene, silicon carbide and more.
Early studies with carbon and glass fiber have demonstrated that surface treatments can lead to improved interfacial adhesion and, thus, better mechanical composite properties. In the case of carbon fiber reinforcement, these surface treatments were targeted toward the improvement of the chemical bond between the carbon fiber and the epoxy matrix resin.
Fiber manufacturers have developed many fiber surface treatments to modify the characteristics of polymer surfaces and to enhance their adhesion to resin matrices. These technologies include anodic oxidation, electro-deposition, wet and dry oxidation, acid etching, low-energy plasma treatments, transcrystallinization, ion implantations, covalent bonding, etc. The basic principle of these technologies is to place chemically active groups on the surface of each fiber. These chemically active groups, in turn, react chemically with other groups in the surrounding matrix to form a strong mechanical bond and, thus, tie the fiber surface and the matrix together.
In low-energy plasma treatments, plasma generated photons and energy particles interact with the fiber surface, usually by free radical chemistry, to enhance the adhesive characteristics of the fiber. The use of low-energy plasma surface treatment is a well known technology, previously discussed at length by Werthelmer et al., “Plasma Treatment of Polymers to Improve Adhesion,” Adhesion Promotion Techniques: Technological Applications, 139-174 (Mittal and Pizzi, ed., 1999); J. C. M. Peng et al., “Surface Treatment of Carbon Fibers,” Carbon Fibers, Third Edition, 180-187 (J. B. Donnet et al., ed., 1998); L. H. Peebles, “Plasma Treatment,” Carbon Fibers Formation, Structure, and Properties, 128-135 (1995); Listen et al., “Plasma Surface Modification of Polymers for Improved Adhesion: A Critical Review,” J. Adhesion Sci. Technol., 7:10:1091-1127 (1993); and J. Delmonte, “Surface Treatment of Carbon/Graphite Fibers,” Technology of Carbon and Graphite Fiber Components, 189-191 (1981).
The use of a plasma surface treatment will generally result in a cleaning of the fiber's surface; an ablation, or etching, of material from the fiber's surface; a cross-linking or branching of the fiber's near-surface molecules; and a modification of the fiber's surface chemical structure. (See Werthelmer et al., supra at 145; and Listen et al., supra at 1096.) Each effect is always present to some degree, although to a variable extent depending upon the fiber substrate, the plasma gas chemistry, the plasma reactor design, and the overall operating parameters. Each of these effects also contributes in a synergistic manner to the enhancement of adhesion. For example, surface cleaning and ablation improves adhesion by removing organic contaminates and weak boundary layers from the fiber's surface. Cross-linking improves adhesion by providing a thin cross-linked layer of molecules on the fiber's surface which mechanically stabilizes the surface and serves as a barrier to inhibit low molecular weight molecules from diffusing into the fiber/matrix interface. Finally, chemical modification, the most dramatic and widely reported effect of plasma, improves adhesion by introducing to the fiber surface new chemical groups capable of interacting and covalently linking with the matrix resin to yield the strongest bonds.
It is also known that ablation may enhance the adhesive characteristics of some polymer surfaces by causing a change in the fiber's surface morphology. This change is usually a result of the cleaning of badly contaminated surfaces, or the removal of weak boundary surface layers formed during the fabrication process, or the treatment of filled or semi-crystalline materials. In particular, plasma removes amorphous polymers many times faster than crystalline polymers or inorganic fillers. Therefore, the over-treatment of polymer surfaces containing zones of amorphous polymers may result in the ablated amorphous zones appearing as random valleys or pits. This change is believed to have the unexpected effect of improving the mechanical interlocking of the polymer surface, while increasing the polymer's surface area available for chemical interactions.
Although it is known that some ablation of reinforcing fibers may improve composite properties, surface treatments for deliberately modifying the topography of fiber surfaces are very limited. This is because present methods generally only provide random ablative activity in those zones containing amorphous polymers, and often require over-treatment of the fiber in order to obtain the modification. Over-treatment, in turn, may also have the undesired effect of reducing the fiber's diameter, resulting in a thin reinforcing fiber having significantly weakened bulk properties. In addition, the etching or pitting of the fiber may result in cornered edges, which may further reduce the bulk properties of the fiber, or create air traps which may interfere with effective fiber/resin binding.
BRIEF SUMMARY OF THE INVENTION
The present invention is summarized in that a novel method is disclosed for producing an undulated surface on reinforcement fibers using a non-uniform microwave generated plasma and microwave radiation. In general, reinforcement fibers are introduced into an oxygen-free atmosphere under pressure, the fibers being under slight tension and at least partially stabilized, and then subjected to a microwave generated plasma flux and microwave radiation, the plasma flux and microwave radiation being varied over either space or time to produce the undulated surface. The plasma is varied by either modulating the power input of the microwave energy or the internal pressure of the plasma chamber in which the plasma is generated, or by altering the angle at which the microwave radiation reacts with the plasma chamber to generate the plasma. Preferably, the plasma is generated in a controlled oxygen free plasma chamber using an oxygen free gas capable of acting as a carrier for the effluents of the processing system. The microwave radiation is generated by a standard microwave generator capable of providing a power input of between 250 W and 100 kW, and more preferably between 750 W and 15 kW.
The undulated surface on the reinforcement fibers can be produced in a batch process, quasi-batch process, or a continuous process. In a continuous process, the intensity of the plasma and the microwave radiation is preferably varied over time to produce the undulated surface on the fiber as it is passed through the plasma field, the intensity variation being induced by either a pulsing of the microwave power level or a gradual change in the microwave power level or a modulation of the internal pressure of the plasma chamber. In a quasi-batch or a batch process the intensity of the plasma and the microwave radiation may be varied over either space or time to create the undulated surface, the variation over space being induced by passing the fiber over a region having a higher intensity of plasma energy or microwave radiation.
Another aspect of the present invention are the fibers produced by the method of the present invention, wherein the cross-sectional area of the fiber is reduced by up to about 50% of its original cross-sectional area, or preferably reduced by up to about 30% of its original cross-sectional area, or more preferably reduced by up to about 15% of its original cross-sectional area.
A principle object of the present invention is to provide a method for increasing the strength of advanced structural composites by improving the mechanical bonding between the composite's resin matrix and its reinforcement fibers.
It is another object of the present invention to provide a novel method for producing an undulated surface on reinforcement fibers in order to improve the fibers' ability to mechanical interlock with composite resins.
It is yet another object of the present invention to utilize plasma technology and electromagnetic radiation to enhance the mechanical binding properties of reinforcement fibers.
One advantage of the present invention is that the surface topography of the fiber can be modified using either a batch, quasi-batch, or continuous system.
Another advantage of the present invention is that the surface of the fiber can be undulated to desired parameters.
Yet another advantage of the present invention is that the use of both a plasma energy and a microwave radiation allows for efficient processing of the reinforcement fibers.
Other objects, features, and advantages will become apparent upon consideration of the following detailed description, drawings and examples.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIGS. 1 a, 1 b and 1 c schematic are example of a fiber filament with its entire circumference modified, including lateral and cross-section views.
FIGS. 2 a, 2 b and 2 c are schematic example of a fiber filament with a portion of its circumference modified, including lateral and cross-section views.
FIG. 3 is a general illustration of the peaks and valleys of an undulated surface produced in accordance with the present invention.
FIG. 4 is a schematic example of a conventional plasma-etched fiber, including lateral and cross-section views.
FIG. 5 is a general illustration of the periods in which surface undulation may be performed.
FIG. 6 is a general illustration of a fiber carbonization system capable of batch processing carbon fiber precursors using plasma and microwave radiation.
FIG. 7 is a general illustration of a double H frame fiber holder generally used in batch processing systems to physically restrain the stabilized carbon fiber precursors under tension.
FIG. 8 is a general illustration of the non-uniform plasma flux along the quartz tube of FIG. 6 .
FIG. 9 is a graph illustration of the typical microwave power and gas pressure profiles during combined microwave and plasma processing of carbon fibers.
DETAILED DESCRIPTION OF THE INVENTION
The present invention utilizes plasma technology in connection with microwave radiation to produce an undulated surface on reinforcement fibers. Fibers so modified are able to more effectively mechanically interlock with composite resins than fibers treated with traditional plasma surface treatments.
The use of accelerated plasma or ions to impact thin surface layers on polymer objects has been described in U.S. Pat. No. 5,389,195 (Ouderkirk et al.). This process uses either short (10 −8 sec. to 10 −3 sec.) high energy pulses of plasma or ions, or scanned beams of high intensity plasma or high fluence ions and charged and neutral particles to impact the object's thin surface layer and alter its chemistry, topography, density, and/or crystal morphology. The process utilizes a plasma or ion directing device, preferably a coaxial plasma gun (e.g., railgun), as a source for the accelerated plasma. Of particular importance is that both high intensity (high power per unit area) and high energy density are required. These two requirements assure that a substantial amount of heat generated in the very thin surface of treatment in a very short time stays in the surface during the short increments of the process, concentrating the energy into the surface layer. Thermal diffusion, from the thin treatment layer into the bulk, reduces the energy concentration and makes the process less efficient. This process, therefore, requires that only a small amount of heat be dissipated into the bulk during the treatment. The more heat that is dissipated into the bulk, the less efficient the process becomes until so much heat goes into the bulk that the process no longer works.
Unlike the process above, the present invention utilizes microwave radiation and non-uniform microwave generated plasma to ablate the surface of the reinforcement fiber in a controlled manner and produce an undulated surface. It is believed that this ablation is a result of a variety of complex mechanisms arising from the combination of the plasma and the microwave radiation. First, a substantial portion of the microwave radiation couples directly to the plasma to produce a flux of electrons, ions, neutral free radicals, and vacuum ultraviolet radiation which couple with the fiber's surface. These combined fluxes have energies many orders of magnitude higher than the normal thermal fluxes used in conventional processes, thus providing an enhanced processing of the outermost layers of the fiber's surface. Second, the remaining microwave radiation which does not couple to the plasma is adsorbed directly by the fibers. This adsorption is believed to be uniform over the bulk of the cross-section of the fiber as the adsorption depth of the microwave energy is much larger than your typical fiber diameter. This energy goes into simple bulk heating of the fiber, while the plasma and ultraviolet flux preferentially processes only the fiber's surface to enhance the desorption of unwanted compounds.
By modulating the intensity of the plasma and the microwave radiation it is possible to produce an undulated surface on the reinforcement fiber. Depending upon the processing parameters, this undulation can be tailored to a predetermined geometry. More specifically, the cross-sectional diameter of the fiber may be modified along the length of the fiber by varying the intensity of the plasma and the microwave radiation as the fiber passes through the plasma and microwave field. This feature both improves the ability of the fiber to mechanically interlock with composite resins, and increases the surface area of the fiber to provide an increased number of sites for enhanced chemical binding and to allow further distribution of loads applied to the final composite material. The combination of these effects ultimately produce a stronger bond between the fiber and the composite resin than could otherwise be obtained using conventional processes.
As shown in FIGS. 1 a - 3 , the undulated surface is characterized to include a continuous rolling topography of peaks and valleys on the fiber's surface, as compared to the generally linear topography of fibers treated with traditional low-pressure plasma treatments (FIG. 4) or conventional carbon fiber processing. The valleys define regions of reduced cross-sectional area in the fiber (FIGS. 1 b and 2 b ) and are generally formed by exposing the region to an increased level of plasma and microwave radiation. The peaks define regions of the fiber in which the cross-sectional area has been maintained (FIGS. 1 c and 2 c ) or reduced to a lesser extent than the regions defining the valleys. In general, the undulated surface may be produced along the entire length of the fiber, but may also be produced in only specified locations along the fiber's axis. In addition, the undulated surface may be produced along the entire circumference of the fiber (as shown in FIGS. 1 a - 1 c ), or produced only along a portion of the fiber's circumference (as shown in FIGS. 2 a - 2 c ).
Referring to FIG. 3, the depth of the valleys (d) and the period between the peaks (λ) may vary depending upon the type of equipment used (applicator plasma profile), the process controls, the type of precursors or fibers to be processed, the plasma conditions (gas, pressure), and the desired properties of the modified fiber. In general, the depth of the valleys (d) will vary depending upon the diameter of the fiber or precursor being processed, the period between the peaks (λ), and whether or not the undulated surface is being produced along the entire circumference of the fiber or along only a portion of the fiber. In the preferred embodiment, the cross-sectional area of the fiber is reduced by up to about 50% of its original cross-sectional area, or preferably reduced by up to about 30% of its original cross-sectional area, or more preferably reduced by up to about 15% of its original cross-sectional area. The depth of the valleys (d) may also depend upon the physical properties of the reinforcement fiber. For example, fibers which are more brittle, such as petroleum-based pitch fibers, would preferably only have their cross-sectional areas reduced by up to about 30%, while high strength fibers (having a low or moderate modulus) could have their cross-sectional areas reduced by up to about 50%.
The period (λ) between the peaks will also vary depending upon the physical properties of the fiber as well as the mechanical properties desired in the final composite material. For example, a more brittle fiber will generally require a gradually change of diameter and, therefore, a greater period between the peaks. A more elastic or ductile fiber, such as a PAN-based fiber with a high elongation at break value, may be able to sustain a more drastic change in diameter and, thus, a shorter period between peaks.
In general the undulated surface is produced on the reinforcement fiber using a non-uniform microwave generated plasma and microwave radiation. The reinforcement fibers modified may include both inorganic and organic fibers which have been at least partially stabilized. Organic fibers may be made of any solid organic, such as natural or synthetic polymeric material, and may include, for example, fibers made of carbon, graphite, nylon, rayon, cellulose, pitch (e.g., petroleum based), polyacrylonitrile (PAN), aramide, polyesters (e.g., polyethyleneterephthalate), polyfluorenes, polyimides, polyamides, polyolefins, polyepoxides, polysiozanes, polyethers, polyetherimides, polysulfones, polyurethanes, fluorinated and/or chlorinated polymers (such as polytetrafluoroethylene), and polyvinyls. Inorganic fibers may be made of solid inorganic material and may include, for example, ceramics (e.g., SiO 2 , TiO 2 , etc.) glass, metals, and silica carbide.
The term “plasma” is used to identify gaseous complexes which may comprise electrons, positive or negative ions, gaseous atoms and molecules in the ground state or any higher state of excitation including light quanta. In the preferred embodiment of the present invention, the plasma is considered a low pressure “cold” plasma and generally comprises gas atoms at room temperature and electrons at much higher temperatures. This plasma state provides an ambient gas temperature along with electrons, which have sufficient kinetic energy to cause the cleavage of chemical bonds.
The plasma utilized in the present invention is generated and maintained in a controlled oxygen free plasma chamber having the capacity to control the introduction of oxygen free gases or the removal of off-gases therefrom so as to allow control of the pressures inside the chamber which are induced by the modification process. The gases utilized in the present invention include those oxygen-free gases capable of maintaining a plasma reaction and serving as a carrier for the effluents generated by the modification process. Examples of such gases include, without limitation, argon, nitrogen, helium, hydrogen, or any mixture thereof.
The microwave radiation is preferably produced by an electromagnetic generator capable of producing an electromagnetic discharge in the microwave frequency range. The generator must also have power levels sufficient to produce an undulated surface using the method of the present invention. In one embodiment, the power input by the microwave generator is preferably between 250 W and 100 kW, and more preferably between 750 W and 15 kW.
In general, the undulated surface may be produced on the fiber at any time during the fiber production process. The fiber, however, must be at least partially stabilized in order to avoid the melting of the fiber. Methods for stabilizing such fibers are well known in the art and may be employed as appropriate for the fiber to be modified.
With respect to carbon fibers, the undulated surface can be produced on the fiber at any stage of the carbonization process once the carbon fiber or its precursor is at least partially stabilized. FIG. 5 illustrates the general process for preparing carbon and graphite fibers and the periods in which surface undulation may be performed. In the illustrated process, surface undulation can be performed at any one of several stages during the carbonization or graphitization process.
In the illustrated process of FIG. 5, the processed fiber originates from a carbon fiber precursor. Carbon fiber precursors are generally defined as carbonaceous material previously spun into fiber form and fully or partially stabilized by a stabilization process effective in preparing the material for carbonization. Such fibers and the methods of their manufacture are well known in the art and generally include, without limitation, rayon-based fibers, PAN-based fibers, pitch-based fibers, or any other fiber spun from material capable of being converted into carbon when heat-treated to temperatures in excess of 500° C. Most preferably, the carbon fiber precursor is either a PAN-based or a pitch-based precursor, and more preferably a PAN-based precursor.
The method of the present invention begins by preparing the fiber for processing. This preparation step generally requires placing the fiber under slight tension to ensure the proper alignment of the fiber's internal structure. For example, in batch processes the fiber may be physically restrained in a fixture, such as an H-frame as illustrated in FIG. 7, so that the fiber will come under tension as the modification process proceeds. Meanwhile, in a continuous process, tension may be maintained by rollers or other mechanisms commonly known in the art.
Once prepared, the fibers to be treated are introduced into an oxygen-free plasma chamber where they are subjected to plasma and microwave radiation in an atmosphere of oxygen-free gas. The plasma is initiated during this process by an electrical discharge or an induced dielectric breakdown, depending upon the processing system utilized. In the preferred embodiment, this discharge is created by a high level electromagnetic frequency discharge generated by the microwave generator. The plasma formed in the plasma chamber interacts with the fiber, initiating the pyrolysis of the fiber and increasing the fiber's dielectric loss tangent (tan δ). The raising of the fiber's tan δ, in turn, increases the fiber's coupling efficiency to the microwave radiation.
The coupling of the plasma and microwave radiation generates a uniform application of microwave energy throughout the fiber's cross-section, resulting in a uniform and homogeneous volumetric heating of the bulk fiber material. This heating promotes the mass exchange of oxygen and evolved gases across the entire cross-section of the fiber. As the input power of microwave radiation is increased, the heating temperature across the fiber's cross section is also increased. This increase in heating temperature results in further processing of the fiber's elements and the release of additional off-gases. The released off-gases, in turn, serve as additional fuel for the plasma and will eventually be partially consumed by the reaction or extracted from the chamber in an effluent gas stream.
As the fiber interacts with the plasma, the microwave radiation input power is varied to produce the undulations on the fiber's surface. This input power is preferably varied between 250 W and 100 kW, and more preferably between 750 W and 15 kW, and will depend upon several factors including, among others, the particular reinforcement fiber being modified, the tow of the fibers as they are processed, and the extent of surface undulation desired in the final product.
Unlike the ablation processes using pulsed plasma guns or ion accelerators, the present invention provides a much cleaner method for ablating inorganic and organic surfaces. This is because no metal electrodes or grids are required to generate the plasma and the plasma is not accelerated toward the fibers. In particular, the use plasma guns and ion accelerators to generate pulsed, accelerated plasmas typically requires the creation of a high-energy arc between two metal electrodes. The arc has the added effect of eroding the metal electrodes to produce a large amount of metal impurity ions in the plasma. These metal ions may then be sputtered on the fiber's surface, having a detrimental effect upon the strength of the fiber. Similarly, the accelerator needs metal extraction grids to accelerate the plasma toward the fibers. Metal grids can also create undesirable metal impurities by etching the metal grids with the plasma.
The undulated surface can be produced in either a batch process, a quasi-batch process, or a continuous process. In a continuous process, the intensity of the plasma and the microwave radiation is preferably varied over time to produce the undulated surface on the fiber as it is passed through the plasma field, the intensity variation being induced by either a pulsing of the microwave power level or a gradual change in the microwave power level or a modulation of the internal pressure of the plasma chamber. In a quasi-batch or a batch process the intensity of the plasma and the microwave radiation may be varied over either space or time to create the undulated surface, the variation over space being induced by passing the fiber over a region having a higher intensity of plasma energy or microwave radiation.
For example, the modification of the reinforcement fiber to produce an undulated surface may be performed in a batch system using a microwave glow-discharge plasma applicator designed to provide a non-uniform plasma over a particular length of space. The surface undulation is produced by translating the fiber along the non-uniform plasma field. Alternatively, the surface undulation can be accomplished by slowly pulsing a uniform microwave field over the length of the fiber or by slowly translating the fiber along a non-uniform microwave field.
A plasma applicator system which produces a non-uniform plasma energy over a particular length of space is illustrated in FIG. 6 . The plasma applicator includes a section of WR 430 waveguide 10 with inner dimensions of 4.30 in. wide by 2.15 in. high by 24 in. long, having a shorting plate 12 affixed to a first end 14 and a 6-kW, 2.45-GHz microwave generator 16 affixed to a second end 18 . A quartz tube 20 having an inlet end 22 and an outlet end 24 passes through the broad wall (4.30 in. wide) of the waveguide 10 at a 15° angle to the waveguide axis so as to be irradiated with microwave radiation generated by the microwave generator 16 and directed towards the quartz tube by the waveguide 10 . In the illustrated embodiment, the quartz tube 12 used for the containment of the fiber samples has a nominal outer diameter of 30 mm and thickness of 2.1 mm. The inlet end 22 of the quartz tube is connected to a leak valve 30 for pressure control of inert gases feed into the system while the outlet end 24 is connected to a mechanical vacuum pump 28 for removing off gases generated during the modification process.
A quartz double H-frame 32 holds the carbon fiber sample 34 as shown in FIG. 7 . In the illustrated embodiment, the sample consists of a bundle of approximately 48,000 to 50,000 individual fiber filaments, collectively referred to as a “tow” 34 . The tow 34 is loosely tied to each end of the double H-frame 32 to allow for natural contraction during processing and placed inside the quartz tube 20 .
The 15° angle of the quartz tube 20 is set to allow the plasma absorption of the microwaves to be tapered along the axis of the waveguide 10 . The intersection of the quartz tube 20 and the waveguide 10 forms an elliptical slot (not shown), wherein the plasma absorption is strongest at the leading edge 26 of the elliptical slot due to locally enhanced microwave electric fields at the sharp metallic corners created by the acute 15° angle of the quartz tube 20 to the waveguide 10 , resulting in an area of increased plasma intensity. (See FIG. 8 ). This tapering of plasma absorption minimizes the microwave power reflected back toward the microwave generator 16 so that no waveguide tuning elements are required. Accordingly, the waveguide 10 is shorted at the first end 14 since almost all the microwave energy is absorbed in the plasma on the first pass along the quartz tube 20 (the quartz tube has a very low microwave absorption).
Since the microwave fields are peaked at the intersection 26 of the quartz tube 20 and the waveguide 10 , the slow translation of the sample 34 on the H-frame 32 back and forth through the applicator 10 allows regions on the tow 34 to be exposed to a slowly varying microwave-generated plasma that has a maximum intensity at the junction of the quartz tube 20 and the leading edge 26 of the waveguide 10 as shown in FIG. 8 . In addition, because the energy propagates across the short radius of the quartz discharge, the plasma does not completely absorb all the microwave energy. This remaining energy is strongly absorbed by the tow 34 allowing the interior of the fibers to be heated. The fiber surface, therefore, is heated by a plasma flux while the fiber interior is heated directly by the microwave energy. This combined processing allows the fiber to be processed much more rapidly than either microwave or plasma processing alone.
In the illustrated embodiment, the normal length of the tow 34 is between twelve and twenty-four inches. The maximum possible length inside the applicator at any time is approximately ten to eleven inches. This means that at any given time, only a portion of the tow 34 is exposed to the combined microwave/plasma. For this reason, the local processing time of any one region along the tow 34 will be vary as compared to the overall processing time of the fiber. It is this non-uniform heating combined with the rapid processing which produces a processing gradient along the fiber's axis to produce the undulated surface on the reinforcement fiber.
In the particular illustrated embodiment, the quartz tube 12 provides the oxygen-free chamber for processing and will contain the generated off-gases (effluents) from the fibers being processed. In a preferred embodiment, an internal pressure of about 3 to 6 Torr of nitrogen or argon gas should be established inside the quartz tube 20 to initiate the glow discharge. The microwave power then breaks down the background gas to establish a microwave glow-discharge plasma. The fiber is processed by moving the quartz tube back and forth through the waveguide applicator 10 in a reciprocating fashion with a period of approximately 4 seconds. This allows a section of the total length of the fibers in the H-frame to reach a temperature wherein a portion of the fiber's organic material is converted to carbon, resulting in the release of off-gasses. Given enough residence time and input microwave power, carbonization and subsequent graphitization will continue until acceptable levels of processing are reached. Microwave power and gas pressure for a typical processing run for fully oxidized or stabilized carbon fiber (PAN) precursor is shown in Table 1 below and illustrated in FIG. 9 . The power is increased in discrete steps to allow for the gases evolved from the fiber to be eliminated by the vacuum system. When the pressure drops to around 3 to 6 Torr, the power is increased and the processing is repeated until a final fiber product has been obtained. It is believed that when the carbon fiber is processed using these steps, a surface undulation will occur on the fiber.
In the example cited, the fiber is being both carbonized and modified to provide an undulating surface topography. It is believed that the surface topography of prior carbonized or graphitized carbon fiber can just as easily be modified. In this case, the fiber is already processed and the evolved carbon fiber off-gas will be much less and the processing time will be much shorter than the recipe shown in FIG. 9 and Table 1.
Another aspect of the present inventions is that the disclosed method can also be performed in a continuous system where the microwave radiation and plasma is varied over a period time. Continuous systems to treat fibers are well known in the art and described previously by Listen et al., supra; and R. Diefendorf, “Carbon/Graphite Fibers,” Engineering Materials Handbook: Composites, 38-42 (1987).
To vary the plasma and microwave radiation, one may simply modulate the microwave power to increase the intensity of the plasma energy and create a process gradient along the length of the fiber. For example, one may gradually increase the microwave power input to increase the intensity of the combined microwave and plasma energy and enhance the processing of the fiber to induce a reduction in the fiber's cross-sectional area. Once the desired cross-sectional area is reached, the power input could then be gradually decreased to slow the processing of the fiber and minimize the cross-sectional reduction. Such an application is likely to result in a gradual surface undulation with an extended period between peaks. Alternatively, one could apply a moderate pulse of microwave input power to cause a rapid decrease in the cross-sectional area and provide a surface undulation having a shortened period between peaks and/or substantial depth.
The net effect of scanning the tow across an intense region of plasma or the application of a varied pulse or scanned microwave radiation is the creation of a processing gradient along the length of the fiber. A beneficial effect of this variability in the fiber processing is the ability to develop localized regions along the fiber wherein the fiber is exposed to higher processing. Through this processing methodology, the enhancement of filament properties in discrete regions is also possible. These filament properties can include higher electrical resistivity, higher density, and higher mechanical strength than in the rest of the bulk carbon fiber.
Once the surface undulation has been completed, the fibers may be subjected to additional oxygen plasma treatments to enhance their adhesive characteristics. In this final step, the remaining oxygen-free gas and off-gases are removed from the plasma chamber and a small level of oxygen is introduced. This oxygen is then consumed by the plasma resulting in the treatment of the fiber's surface in a manner typically utilized in commonly known plasma surface treatments. Caution must be taken, however, to avoid introducing too much oxygen into the chamber as excess oxygen may result in a negative thermal reaction and loss of fiber product. Alternatively, the fibers may be removed from the plasma applicator system and treated with any one of the many plasma surface treatments known in the art which are used to modify the fiber surface's chemical structure.
Although the descriptions above the modification of reinforcement fibers using a single plasma chamber and a single source of microwave radiation, it is anticipated that a series of plasma chambers or a series of electromagnetic generators may be utilized to practice the disclosed method in a continuous process. These processes may include, without limitation, a continuous flow process similar to a kiln type application with no physical separation between stages in processing, or a continual sequence process having discrete processing stages. It is also anticipated that one of ordinary skill in the art would be sufficiently familiar with plasma operations to adjust the reaction to accommodate different fibers, gases, and systems to produce an undulated surface on the reinforcement fibers. Accordingly, this invention is not limited to the preferred embodiments and alternatives heretofore described, to which variations and improvements may be made.
TABLE 1
Carbon Fiber Processing Conditions
Initial
Percent
Sample
Fiber wt.
Wt. Loss
5
6.01 g.
Power Input
400
500
600
700
800
900
43.0%
(Watts)
Minutes
7
5
5
5
5
5
8
4.10 g.
Power Input
700
1000
1400
1700
—
—
45.0%
(Watts)
Minutes
5
5
7
3
—
—
9
4.70 g.
Power Input
800
1200
1500
2000
—
—
51.3%
Minutes
5
5
5
5
—
—
(Watts)
15
4.52 g.
Power Input
750
1000
1400
2000
—
—
44.0%
(Watts)
Minutes
5
6
5
4
—
—
17
3.80 g.
Power Input
600
800
1000
1400
1800
2000
50.0%
(Watts)
Minutes
3
3
5
5
5
5
18
4.40 g.
Power Input
700
1000
1500
2000
—
—
52.3%
(Watts)
Minutes
4
4
4
4
—
—
19
3.60 g.
Power Input
700
1000
1500
1800
—
—
42.5%
(Watts)
Minutes
4
4
5
4
—
—
21
4.00 g.
Power Input
600
800
1000
1400
1800
2000
50.0%
(Watts)
Minutes
4
4
4
4
4
4
NOTE:
Initial pressure at each stage for each sample was approximately 3 to 6 TorrS. | The present invention introduces a novel method for producing an undulated surface on composite fibers using plasma technology and microwave radiation. The undulated surface improves the mechanical interlocking of the fibers to composite resins and enhances the mechanical strength and interfacial sheer strength of the composites in which they are introduced. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application No. 61/753,299 entitled “Integral nano-scale pump and injector for high performance liquid chromatography” filed on Jan. 16, 2013 in the United States Patent and Trademark Office and which is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention pertains to pump and injection valve systems for use with liquid chromatography. More particularly, the present invention pertains to a combined pump/injection valve for injection of a nanoliter-sized sample into a chromatography column utilizing an single piece as the barrel of the pump and as the stator of the valve, thus eliminating any need for connections between the pump and valve.
2. Description of the Related Art
High performance liquid chromatography (HPLC) is generally performed using pumps, columns and injection valves scaled to deliver fluids at flow rates measured in cubic centimeters of fluid per minute. These components are typically separate and joined together to provide a system for HPLC. Unfortunately, these systems require relatively large sample volumes, large mobile phases, and large flow rates for analysis.
Additionally, these relatively large systems frustrate generate of field portable HPLC units, where there is a need for a lightweight robust flow system which uses a minimum of mobile phase during an analysis.
It would therefore be desirable to provide an integrated nano-scale pump and injection valve for high performance liquid chromatography.
SUMMARY OF THE INVENTION
The present invention therefore meets the above needs and overcomes one or more deficiencies in the prior art by providing a combined pump/injector valve which injects nanoliter samples into a chromatographic column, which is sealed during loading of the sample and filling of the pump, such that complete analyses can be completed with microliters of mobile phase, ranging from as small as about 5-10 nanoliters, to 60 nanoliters, and larger. The present invention therefore provides a lightweight robust flow system which uses a minimum of mobile phase during an analysis and is appropriate for use as a field portable HPLC unit.
The present invention provides an integral nano-scale pump and injection valve for high performance liquid chromatography which includes an integrated barrel-stator, which has an elongate barrel in a first end and a stator at a second end, a plunger slidably disposed within an interior chamber of the barrell of substantially uniform cross-section, and a rotor, wherein the pump and injection valve is switchable between a load position and a injection position. In one embodiment, the circular rotor has a surface adjacent the stator and has a plurality of channels in its surface and is with respect to the stator about a centerpoint between the load position and the injection position. The elongate barrel portion of the integrated barrel-stator includes an open ends, a length, and a sidewall defining the interior chamber adapted to receive a supply of fluid, an outer diameter, and a wall thickness. The circular stator has an orifice therethrough at its centerpoint and a first side and a second side such that the elongate barrel open distal end is aligned with the second side of the stator at the centerpoint and the interior chamber includes the orifice. The pump is therefore in communication with the valve at the orifice.
In a first embodiment, the rotor includes three channels and the stator has a first stator port for communication with a mobile phase supply, a second stator port in communication with a fifth stator port, a third stator port for communication with a sample reservoir, a fourth stator port for sample outflow, a sixth stator port for communication with a chromatography column, a seventh stator port for return from the chromatography column, and an eighth stator port for outflow from the valve. In the first embodiment, the load position is defined by the first port and the orifice communicating with a first channel and by the third port and the fourth port communicating with a second channel. In the first embodiment, the injection position is defined by the orifice and the second port communicating with the first channel, by the fifth port and the sixth port communicating with the second channel, and by the seventh port and the eighth port communicating with the third channel.
In the alternative embodiment, the rotor includes four channels and the stator has a first stator port for communication with a mobile phase supply, a second stator port in communication with a fifth stator port via an external loop, a third stator port for communication with a sample reservoir, a fourth stator port for sample outflow, a sixth stator port for communication with a chromatography column, a seventh stator port for return from the chromatography column, and an eighth stator port for outflow from the valve. In the alternative embodiment, the load position is defined by the first port and the orifice communicating with a first channel, by the second port and the third port communicating with the second channel, and the fourth port and the fifth port communicating with the third channel. In the alternative embodiment, the injection position is defined by the orifice and the second port communicating with the first channel, by the fifth port and the sixth port communicating with the third channel, and by the seventh port and the eighth port communicating with the fourth channel.
In a further alternative embodiment, where the embodiment is used as a pump without regard to the equipment connected thereto, the rotor has only one channel and the stator has a first stator port for communication with a mobile phase supply and a second stator port for communication with an external device. In the further alternative embodiment, the load position is defined by the first port and the orifice communicating with a first channel and the injection position is defined by the orifice and the second port communicating with the first channel.
In an additional alternative embodiment, wherein the the embodiment is used to push sample through a column, but wherein the output of the column is provided to other equipment rather than through the valve, the embodiment includes channels and the stator has a first stator port for communication with a mobile phase supply, a second stator port in communication with a fifth stator port via an external loop, a third stator port for communication with a sample reservoir, a fourth stator port for sample outflow, and a sixth stator port for communication with a chromatography column. In the additional alternative embodiment, the load position is defined by the first port and the orifice communicating with a first channel, by the second port and the third port come communicating with the second channel, and the fourth port and the fifth port communicating with the third channel. In the alternative embodiment, the injection position is defined by the orifice and the second port communicating with the first channel, and by the fifth port and the sixth port communicating with the third channel.
Additional aspects, advantages, and embodiments of the invention will become apparent to those skilled in the art from the following description of the various embodiments and related drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the described features, advantages, and objects of the invention, as well as others which will become apparent are attained and can be understood in detail; more particular description of the invention briefly summarized above may be had by referring to the embodiments thereof that are illustrated in the drawings, which drawings form a part of this specification. It is to be noted, however, that the appended drawings illustrate only typical preferred embodiments of the invention and are therefore not to be considered limiting of its scope as the invention may admit to other equally effective embodiments.
In the drawings:
FIG. 1 is an illustration of a top view of one embodiment of the present invention as assembled.
FIG. 2 is an illustration of a side view of one embodiment of the present invention as assembled.
FIG. 3 is an illustration of the face of the stator of the integrated barrel-stator of the first embodiment of the present invention.
FIG. 4 is an illustration of the face of the rotor of the first embodiment of the present invention.
FIG. 5 is an illustration of the relative positions of the face of the stator and the face of the rotor of the first embodiment of the present invention in the load position.
FIG. 6 is an illustration of the relative positions of the face of the stator and the face of the rotor of the first embodiment of the present invention in the injection position.
FIG. 7 is a cross-section illustration of the present invention along line Z-Z of FIG. 1 for the maximum position of the pump associated with the load position in connection with a linear actuator.
FIG. 8 is a cross-section illustration of the present invention along line Z-Z of FIG. 1 for the maximum position of the pump in the injection position in connection with a linear actuator.
FIG. 9 is a close-up of the pump plunger driven forward for delivery for the maximum position of the pump in the injection position.
FIG. 10 is an illustration of isometric view of the embodiment of the present invention with the pump and valve actuators illustrating the first valve position illustrated in FIGS. 5 and 7 at the maximum position of the pump in the load position.
FIG. 11 is an illustration of isometric view of the embodiment of the present invention with the pump and valve actuators illustrating the second valve position illustrated in FIGS. 6 and 8 at the maximum position of the pump in the injection position.
FIG. 12A is an enlargement of Section A of FIG. 10 .
FIG. 12B is an enlargement of Section B of FIG. 11 .
FIG. 13 is an illustration of the face of the stator of the integrated barrel-stator in the alternative embodiment of the present invention.
FIG. 14 is an illustration of the face of the rotor of the alternative embodiment of the present invention.
FIG. 15 is an illustration of the relative positions of the face of the stator and the face of the rotor of the alternative embodiment of the present invention in the load position.
FIG. 16 is an illustration of the relative positions of the face of the rotor and the face of the rotor of the alternative embodiment of the present invention in the injection position.
FIG. 17 is an illustration of the relative positions of the face of the stator and the face of the rotor of the further alternative embodiment of the present invention in the load position.
FIG. 18 is an illustration of the relative positions of the face of the rotor and the face of the rotor of the further alternative embodiment of the present invention in the injection position.
FIG. 19 is an illustration of the relative positions of the face of the stator and the face of the rotor of the additional alternative embodiment of the present invention in the load position.
FIG. 20 is an illustration of the relative positions of the face of the rotor and the face of the rotor of the additional alternative embodiment of the present invention in the injection position.
FIG. 21 is a close-up of the pump plunger driven forward for delivery for the maximum position of the pump in the injection position depicting a seal of the present disclosure.
FIG. 22 is an illustration of the relative positions of the face of the stator and the face of the rotor of the additional alternative, embodiment of the present invention in the load position.
FIG. 23 is an illustration of the relative positions of the face of the rotor and the face of the rotor of the additional alternative embodiment of the present invention in the injection position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2 , a two-position embodiment of the integrated nano-scale pump and injection valve 100 is provided. A top view of one embodiment of the integrated nano-scale pump and injection valve 100 as assembled is provided in FIG. 1 while a side view is provided FIG. 2 . As illustrated in FIGS. 1B and 2 , the integrated nano-scale pump and injection valve 100 includes an integrated barrel-stator 716 which provides the interface between the pump section 102 and valve section 104 .
Referring to FIGS. 3 and 4 , constructions of the face of the stator 302 and the face of the rotor 402 of the integrated barrel-stator 716 are illustrated for a first embodiment. Referring to FIGS. 13 and 14 , constructions of the face of the stator 302 of the integrated barrel-stator 716 and the face of the rotor 1402 of the valve section 104 are illustrated for an alternative embodiment.
Referring to FIGS. 1-22 , by forming the elongate barrel 726 of the pump 708 and the stator 302 , 1302 , 1712 , 1932 of the valve 710 of a single part as integrated barrel-stator 716 , the integrated nano-scale pump and injection valve 100 may operate at high pressures without degradation incident to intervening parts and fittings.
Unlike the prior art where a valve and pump were separate bodies simply joined together, in the integrated nano-scale pump and injection valve 100 , as illustrated in FIGS. 7-12B , the elongate barrel 726 of the pump 708 and the stator 302 , 1302 , 1712 , 1932 of the valve 710 are integrally formed of a single piece to provide direct communication between the pump 708 and the valve 710 without introducing any fittings or connectors which may swell or leak during high pressure operation.
By switching between the maximum extent of the load position 502 , 1502 , 1710 , 1928 and the maximum extent of the injection position 602 , 1602 , 1802 , 2002 , the integrated nano-scale pump and injection valve 100 provides a pump 708 , which may be sized to hold microliters for use with nano-scale columns for quick separation.
Upon initiation of loading, the pump 708 and valve 710 and positioned in the load position 502 and the plunger 706 begins being retracting by the piston 712 and draws a solvent from a reservoir, such as through a 15 cm×200 μm steel tube into the barrel 726 . At the same time and independent of pump filling, a sample is introduced into the sample loop through a 5.08 cm×75 μm inner diameter capillary, which is connected to the port 308 on the pump and to a sample supply, preferably using a zero-dead volume connector.
After completion of loading, the integrated nano-scale pump and injection valve 100 may be switched for injection, changing the direction of operation of the pump 708 and changing the position of the valve 710 . During injection, the plunger 706 is driven by the piston 712 into the barrel 726 . The rate of advance, and therefore the dispensing flow rate, may be controlled by power supply and/or by computer software. As the plunger 706 is driven forward by the piston 712 , the sample is driven from the sample passage of second channel 406 into the column 504 while the mobile phase flows from the barrel 726 through the loop 506 , through the column 504 and to the detector.
In all embodiments, in the load position 502 , 1502 , 1710 , 1928 , the pump plunger 706 is retracted for filling the interior chamber 702 as illustrated in FIGS. 7, 10 and 12A . The plunger may have a diameter of 0.03 inches, or slightly smaller, or of 0.93 inches, or slightly larger, or may be between, such as 0.62 inches. The pump 708 thus includes a pump plunger 706 , an interior chamber 702 defined by an elongate barrel 726 and the plunger 706 . Referring to FIGS. 5, 7, 10, 12A and 15 , the arrangement and nano-scale operation of integrated nano-scale pump and injection valve 100 is illustrated in at the maximum position of the pump 708 in the load position 502 . The load position 502 of integrated nano-scale pump and injection valve 100 , showing the positions of the stator 302 and the rotor 402 in the first embodiment, is depicted in FIG. 5 . The load position 1502 of integrated nano-scale pump and injection valve 100 , showing the positions of the stator 1302 and the rotor 1402 for the alternative embodiment is depicted in FIG. 15 . As can be appreciated either the stator 302 , 1302 , 1712 , 1932 or the rotor 402 , 1402 , 1702 , 1902 will include a seal surface to contact the other. A cross-section illustration of the present invention along line Z-Z of FIG. 1 for the maximum position of the pump 708 in the load position 502 , 1502 , 1710 , 1928 is illustrated in FIG. 7 . An illustration of isometric view of the embodiment of the present invention with the valve actuator illustrating the first valve position is illustrated in FIG. 10 . An enlargement of Section A of FIG. 10 is provided in FIG. 12A .
Referring to FIG. 21 , for operation at high pressure, such as above 10000 psi, it is essential that a strong seal 2150 be positioned about the plunger 706 within the barrel 726 of the integrated barrel-stator 716 , at least a stroke-length 1202 above or beyond the first end 750 of the plunger 706 when in the maximum injection position so as to contact the plunger 706 and to form a seal thereabout. Positioning the seal 2150 less than a stroke-length 1202 from the first end 750 of the plunger 706 would cause the seal 2150 to fail when the plunger 706 was fully retracted to reach the maximum load position. While a single seal across the barrel 726 , through which the plunger 706 would move, may be used, a composite seal is preferable. As depicted in FIG. 21 , the seat 2150 about the plunger 706 within the barrel 726 may be formed of a compressed sequence of a first hard seal 2100 , a flexible seal 2108 , and a second hard seal 2112 , placed under compression by a driving disk 2106 maintained within the integrated barrel-stator 716 . The diameter of the barrel 726 of the integrated barrel-stator 716 is enlarged for that section more than a stroke-length 1202 above or beyond the first end 750 of the plunger 706 when in the maximum injection position to accept a first hard plastic seal 2100 . The first hard plastic seal 2100 may be composed of a material such as polyether ether ketone (PEEK) or another material, and is sized to fit within the barrel 726 and about the plunger 706 without precluding movement of the plunger 706 . Atop the first hard plastic seal 2100 is positioned a flexible seal 2108 . The flexible seal 2108 is composed of a compressible sealing material, such as polytetrafluoroethylene (PTFE). The flexible seal 2108 is sized to fit within the barrel 726 and about the plunger 706 without precluding movement of the plunger 706 . Atop the flexible seal 2108 is positioned a second hard plastic seal 2112 , which may also may be composed of a material such as polyether ether ketone (PEEK) or another material, and is sized to fit within the barrel 726 and about the plunger 706 without precluding movement of the plunger 706 . Compression of the flexible seal 2108 results in lateral expansion of the flexible seal 2108 and thereby causes the flexible seal 2108 to provide a seal against the plunger 706 which does not preclude movement of the plunger 706 , between the first hard seal 2100 and the second hard seal 2112 . This may be accomplished, by application of force against the second hard seal 2112 and a shoulder 2114 in the barrel 726 to maintain the position of the first hard seal 2100 . The application of force against the second hard seal 2112 may be obtained by joining a threaded male sleeve or nut 2102 , having a bore therethrough to freely accommodate the plunger 706 and piston 712 without interference, to the integrated barrel-stator 716 , above or beyond the seal 2150 , which threaded male sleeve 2102 would apply force to one or more springs 2122 , particularly a Belleville spring also known as a coned disc spring, positioned within the integrated barrel-stator 716 above or adjacent the barrel 726 , to force a driving disk 2106 to compress the second hard seal 2112 . The threaded male sleeve 2102 is sized to a threaded female section of the integrated barrel-stator 716 above or adjacent the barrel 726 . The driving disk 2106 includes a bore 2124 sized to permit the plunger 706 to pass therethrough without interference, a shoulder 2116 to permit the application of force against the driving disk 2106 from the springs 2122 smaller in diameter than the threaded male sleeve or nut 2102 so as not to contact the inner walls of the integrated barrel-stator 716 , and a neck 2120 at its end 2126 proximate the barrel 726 sized to enter the barrel 726 without interference and having sufficient height to contact and apply force against the second hard seal 2112 . As a result, the neck 2120 is driven against the second hard seal 2112 , which is in turn driven into the flexible seal 2108 to compress it and form a seal about the plunger 706 . The plunger 706 is therefore able to move through the seal 2150 without fluid seeping past, even as the flexible seal 2108 may become pliable during repeated movement of the plunger 706 . Because only the seals 2112 , 2108 , 2100 laterally contact the plunger 706 , and because the balance of the components, including the integrated barrel-stator 716 , the threaded male nut or sleeve 2102 , and the driving disk 2106 , include sufficient clearance for the plunger 706 to move without interference, the plunger 706 can move within the barrel 726 and can operate to draw or eject fluid into the barrel 726 and through the stator 302 , particularly at high pressure.
Thus, the seal 2150 includes a first hard plastic seal 2100 , a flexible seal 2108 , a second hard plastic seal 2112 and is compressed to seal about the plunger 706 by a driving disk 2106 , a threaded male sleeve 2102 , and one or more springs 2122 . The first hard plastic seal 2100 is sized to fit within the barrel 726 and to fit about the plunger 706 . The flexible seal 2108 is sized to fit within the barrel 726 and to fit about the plunger 706 adjacent the first hard plastic seal 2100 . The second hard plastic seal 2112 is sized to fit within the barrel 726 and to fit about the plunger 706 adjacent the flexible seal 2108 . The driving disk 2106 has a bore 2124 therethrough sized to fit about the plunger 706 without interference, a first end 2118 and a second end 2126 . The driving disk 2106 is sized to freely fit within said integrated barrel-stator 716 adjacent the barrel 726 , and includes a shoulder 2116 near the first end 2118 , and a neck 2120 at the second end 2126 , which neck 2120 is sized to fit within the barrel 726 and to contact the first hard plastic seal 2100 . The threaded male sleeve 2102 has a bore therethrough sized to permit movement of the plunger 706 without interference and is sized to a threaded female section within the integrated barrel-stator 716 above, or adjacent, the barrel 726 . The spring 2122 contacts the shoulder 2116 of the driving disk 2106 and an end of said threaded male sleeve 2102 and is compressed as the threaded male sleeve 2102 is driven into the integrated barrel stator 716 .
Referring to FIG. 5 , in the first embodiment, the valve 710 thus has a circular stator 302 , formed integrally with the elongate barrel 726 to form integrated barrel-stator 716 , and a circular rotor 402 where the two components cooperate to permit or preclude fluid communication among various parts of the valve 710 . The stator 302 has an orifice 320 at its centerpoint, as well as a first stator port 304 for communication with a mobile phase supply, a second stator port 306 in communication with a fifth stator port 312 , a third stator port 308 for communication with a sample reservoir, a fourth stator port 310 for outflow of sample waste, a sixth stator port 314 for communication with a chromatography column 504 , a seventh stator port 316 for return from the chromatography column 504 , and an eighth stator port 318 for outflow from the valve 710 such as to a detector. As both ends of the column 504 can be connected to the integrated nano-scale pump and injection valve 100 to maintain pressure during filling of the integrated nano-scale pump and injection valve 100 when the flow through the column 504 is stopped, if desired. This would eliminate a delay period for column re-pressurization. The rotor 402 therefore has a surface adjacent the stator 302 and three channels, or slots, 404 , 406 , 408 in its surface. The rotor 402 is rotable with respect to the stator 302 about the centerpoint between the load position 502 and the injection position 602 . Rotation between the two positions may be 45 degrees about the centerpoint, or more or less, in the load position 502 , components are isolated while the mobile phase is delivered to the internal chamber 702 of the pump 708 , so that the first port 304 communicates with the orifice 320 , and thereby to the internal chamber 702 of the pump 708 , via the first channel 404 , to provide filling, while all other ports are individually or paired in isolation, include the third port 308 and the fourth port 310 , while communicating via the second channel 406 not otherwise communicating with any other components. The column 504 may therefore maintained at pressure and isolated while the interior chamber 702 of the pump 708 located in the pump section 102 , as illustrated in FIG. 7 , is filled by a mobile phase by drawing mobile phase through orifice 320 , introduced via first channel 404 which is connected to port 304 . For initial charging of the column 504 , the operator can run the mobile phase through the second channel 406 , the sample channel, switching between the load position 502 and the injection position 602 to fill the column 504 and to ensure no bubbles are present in the system. In the load position 502 , the port 318 , which may be connected to a detector, is likewise isolated. Referring to FIGS. 3 and 4 , and more particularly to FIG. 5 , in this load position 502 , with reference to stator 302 and rotor 402 , ports 306 and 312 are in communication to form a loop 506 , to provide an internal sample, but are otherwise isolated. This loop 506 may be of 5.08 cm×75 or 150 μm inner diameter stainless steel tubing to carry the mobile phase to the column during injection (dispensing). A sample is introduced to and flows through the integrated nano-scale pump and injection valve 100 at port 308 , the sample inlet port, which is connected via second channel 406 to port 310 , the waste outlet port. As can be appreciated each port is associated with a connector 206 on the intersection of the pump section 102 and the valve section 104 . During the introduction of the sample, second channel 406 therefore contains the sample to be tested. Thus, in this load position 502 , a sample, which may originate from an external reservoir, may be flowed through an internal passage. In the injection position 602 , mobile phase is delivered from the pump 708 and directed through the valve 710 to the column 504 and potentially to a downstream detector by connecting the orifice 320 , which is in communication with the pump 708 , and the second port 306 via the first channel 404 , by connecting the fifth port 312 and the sixth port 314 via the second channel 406 , which thereby provides a complete flow path to the chromatography column 504 , and by connecting the seventh port 316 , which is in communication with the outflow of the column 504 , with the eighth port 318 via the third channel 408 so that the sample separated by the column 504 may be processed by a detector. As can be appreciated, in a secondary embodiment, the seventh port 316 , the eighth port 318 and the third channel 408 could be omitted and the outflow from the column 504 provided directly to a detector or other equipment.
Due to the volumes involved, refilling of the integrated nano-scale pump and injection valve 100 may be accomplished is less than 2 minutes. Since typical flow rates used in capillary columns (100-150 μm i.d.) range from 100 to 500 nL/min, an isocratic separation can be easily completed without the need to refill the integrated nano-scale pump and injection valve 100 .
In the alternative embodiment, such as depicted in FIGS. 13, 14, 15, and 16 , the valve 710 has a circular stator 302 , again formed integrally with the elongate barrel 726 , and a circular rotor 402 where the two components cooperate to permit or preclude fluid communication among various parts of the valve. As with the stator of the first embodiment, the stator 1302 has an orifice 1320 at its centerpoint with the pump 708 in communication with the valve 710 at the orifice 1320 , a first stator port 1304 for communication with a mobile phase supply, a second stator port 1306 in communication with a fifth stator port 1312 via a loop 1506 , a third stator port 1308 for communication with a sample reservoir, a fourth stator port 1310 for outflow, a sixth stator port 1314 for communication with a chromatography column 1504 , a seventh stator port 1316 for return from the chromatography column 1504 , and an eighth stator port 1318 for outflow from the valve 710 such as to a detector. The rotor in the alternative embodiment includes the four channels 1404 , 1406 , 1408 , 1410 in its surface, in the alternative embodiment, the load position 1502 is defined by the first port 1304 and the orifice 1320 communicating with the first channel 1404 , by the second port 1306 and the third port 1308 communicating with the second channel 1406 , and the fourth port 1310 and the fifth port 1312 communicating with the third channel 1408 . In the alternative embodiment, as illustrated in FIG. 15 , the column 504 is attached to port 1314 , column inflow, and port 1316 , column outflow, which are otherwise isolated. The column 1504 is therefore maintained at pressure and isolated while the interior chamber 702 of the pump 708 located in the pump section 102 , as illustrated in FIG. 7 , is filled by a mobile phase by drawing mobile phase through orifice 1320 , introduced via the first channel 1404 , the fill/dispense channel, which is connected to port 1304 . In the load position 502 , the port 318 , which may be connected to a detector, is likewise isolated. Referring to FIGS. 13 and 14 , and more particularly to FIG. 15 , in this load position 502 , with reference to stator 1302 and rotor 1402 , ports 1306 and 1312 are in communication to form a loop 1506 but are otherwise isolated. A sample is introduced to and flows through the integrated nano-scale pump and injection valve 100 at port 1308 , the sample inlet port, which is connected via second channel 1406 to port 1306 and then, via a loop 1506 to port 1312 , which is then in communication with port 1310 via third channel 1408 , the waste outlet port. As can be appreciated each port is associated with a connector 206 . During the introduction of the sample, the sample to be tested is contained with the channel 1406 and the loop 506 , providing for an increased sample size. Thus, in this load position 502 , a sample, which may originate from an external reservoir, may be flowed through an internal passage. In the alternative embodiment, the injection position 1602 is defined by the orifice 1320 and the second port 1306 communicating with the first channel 1404 , by the fifth port 1312 and the sixth port 1314 communicating with the third channel 1408 , and by the seventh port 1316 and the eighth port 1318 communicating with the fourth channel 1410 .
In the first embodiment, the second channel 406 defines the nano-scale sample size while the interior chamber 702 contains the volume from which mobile phase is pumped. In the alternative embodiment, the third channel 1408 and the loop 1506 define the nano-scale sample size.
Referring to FIGS. 6, 8, 9, 11, and 12B , the nano-scale operation of the pump section 102 is illustrated in the injection position 602 for the first embodiment. The injection position 602 of the nano-scale operation of the pump section 102 , showing the positions of the stator 302 and the rotor 402 , is depicted in FIG. 6 . As illustrated in FIG. 6 , the rotor is rotated 45 degrees, preferably by a mechanical valve actuator 202 coupled to act in concert with the action of the linear pump actuator 204 , generating a new flow path within the valve 710 . The relative position between the stator 302 and the rotor 402 may be set to provide for a greater or lesser rotation. Referring to FIG. 6 , the first channel 404 , the fill/dispense channel, connects the internal pump 708 , via orifice 320 , to the loop 506 at port 312 . The loop 506 now connects to second channel 406 containing the sample. Ports 308 and 310 are now isolated, preventing further inflow of any sample. Similarly, port 304 is isolated, preventing further inflow of mobile phase. As second channel 406 containing the sample now connects to the inlet of the column 504 via port 314 and as channel 408 now connects the outlet of the column 504 , at port 316 , to the port 318 , the outlet to the detector, a complete flow path is established and the mobile phase pushes the sample through the column 504 and to any connected detector. This is accomplished by the pump plunger 706 being driven toward the valve 710 as illustrated in FIGS. 8, 10 and 12B , displacing fluid from the interior chamber 702 into the valve 710 . Thus, the pump 708 delivers fluid through the sample passage of second channel 406 into the column 504 . When the drive shaft 730 of the valve 710 is rotated by a valve actuator 202 , the pump 708 is started, which results in the pump 708 starting the moment the endpoint is reached and thus avoids the column bed becoming unstable. As can be appreciated, upon completion of the analysis, the integrated nano-scale pump and injection valve 100 is returned to the load position 502 , the filling position.
Referring to FIGS. 8, 9, 11, 12B, and 16 , the nano-scale operation of the pump section 102 is illustrated in the injection position 1602 for the second embodiment. The injection position 1602 of the nano-scale operation of the pump section 102 , showing the positions of the stator 1302 and the rotor 1402 , is depicted in FIG. 16 . As illustrated in FIG. 16 , the rotor is rotated 45 degrees, preferably by a mechanical valve actuator 202 coupled to act in concert with the action of the linear pump actuator 204 , generating a new flow path within the valve 710 . The relative position between the stator 1302 and the rotor 1402 may be set to provide for a greater or lesser rotation. Referring to FIG. 16 , first channel 1404 , the fill/dispense channel, connects the internal pump 708 , via orifice 1320 , to the loop 1506 at port 1312 . The loop 1506 , containing some sample, connected to third channel 1408 also containing some sample, now connects to the inlet of the column 1504 via port 1314 and as third channel 1408 now connects the outlet of the column 1504 , at port 1316 , to the port 1318 , the outlet to the detector, a complete flow path is established and the mobile phase pushes the sample through the column 1504 and to any connected detector. This is accomplished by the pump plunger 706 being driven toward the valve 710 as illustrated in FIGS. 8, 10 and 12B , displacing fluid from the interior chamber 702 into the valve 710 . Thus, the pump 708 delivers fluid into the column 504 . Ports 1308 and 1310 are isolated, preventing further inflow of any sample. Similarly, port 1304 is isolated, preventing further inflow of mobile phase. When the drive shaft 730 of the valve 710 is rotated by a valve actuator 202 , the pump 708 is started, which results in the pump 708 starting the moment the endpoint is reached and thus avoids the column bed becoming unstable. As can be appreciated, upon completion of the analysis, the integrated nano-scale pump and injection valve 100 is returned to the load position 502 , the filling position.
Referring to FIGS. 17 and 18 , the present disclosure may alternatively be used as a pump without regard to the equipment connected thereto. In the further alternative embodiment, the rotor 1702 has a channel 1704 and the stator 1712 has a first stator port 1706 for communication with a mobile phase supply, an orifice 1714 in communication with the elongate barrel 726 and a second stator port 1708 for communication with an external device. In the further alternative embodiment, the load position 1710 , as illustrated in FIG. 17 , is defined by the first port 1706 and the orifice 1714 communicating with the channel 1704 and the injection position 1802 is defined by the orifice 1714 and the second port 1708 communicating with the channel 1704 . As can be appreciated, any number of additional ports may be positioned on the stator 1712 to permit the pump to draw fluid through the first port 1706 to be pumped to any one of a plurality of ports, providing a multiple position valve.
Referring to FIGS. 19 and 20 , the present disclosure may be used to push a sample through a column, wherein the output of the column is provided to other equipment rather than through the valve. In the additional alternative embodiment, the rotor 1902 has a first channel 1904 , a second channel 1906 , and a third channel 1926 , and the stator 1932 has the orifice 1924 in communication with the elongate barrel 726 , a first stator port 1908 for communication with a mobile phase supply, a second stator port 1910 in communication with a fifth stator port 1912 via an external loop 1914 , a third stator port 1916 for communication with a sample reservoir, a fourth stator port 1918 for sample outflow, and a sixth stator port 1920 for communication with a chromatography column 1922 . In the additional alternative embodiment, the load position 1928 is defined by the first port 1908 and the orifice 1924 communicating with a first channel 1904 , by the second port 1910 and the third port 1916 communicating with the second channel 1906 , and the fourth port 1918 and the fifth port 1912 communicating with the third channel 1926 . In the alternative embodiment, the injection position 2002 is defined by the orifice 1924 and the second port 1910 communicating with the first channel 1904 , and by the fifth port 1912 and the sixth port 1920 communicating with the third channel 1926 , which is connected to a column 1922 connected to the sixth port 1920 .
Referring to FIGS. 22 and 23 , the present disclosure may be used to push an internal sample through a column, wherein the output of the column is provided to other equipment rather than through the valve, incorporating the structure and flow paths of the first embodiment depicted in FIGS. 3-6 excerpt for the third channel 408 , and the seventh port 316 and the eighth port 318 , which are omitted. FIG. 22 is an illustration of the relative positions of the face of the stator and the face of the rotor of the additional alternative embodiment of the present invention in the load position. FIG. 23 is an illustration of the relative positions of the face of the rotor and the face of the rotor of the additional alternative embodiment of the present invention in the injection position. Referring to FIG. 22 , the valve 710 has a circular stator 2202 , formed integrally with the elongate barrel 726 to form integrated barrel-stator 716 , and a circular rotor 2250 where the two components cooperate to permit or preclude fluid communication an various parts of the valve 710 . The stator 2202 has an orifice 2220 at its centerpoint, as well as a first stator port 2204 for communication with a mobile phase supply, a second stator port 2206 in communication with a fifth stator port 2212 via a loop 2260 , a third stator port 2208 for communication with a sample reservoir, a fourth stator port 2210 for outflow of sample waste, and a sixth stator port 2214 for communication with a chromatography column 2280 . The rotor 2250 therefore has a surface adjacent the stator 2202 and two channels, or slots, 2254 , 2256 in its surface. The rotor 2250 is rotable with respect to the stator 2202 about the centerpoint between the load position 2222 and the injection position 2232 . The injection position 2232 of the nano-scale operation of the pump section 102 , showing the positions of the stator 2202 and the rotor 2250 , is depicted in FIG. 23 . The first channel 2254 , the fill/dispense channel, connects the internal pump 708 , via orifice 2220 , to the loop 2260 at port 2212 . The loop 2260 now connects to second channel 2256 containing the sample. Ports 2208 and 2210 are now isolated, preventing further inflow of any sample. Similarly, port 2204 is isolated, preventing further inflow of mobile phase. As second channel 2256 containing the sample now connects to the inlet of the column 2280 via port 2214 , providing a complete flow path so the mobile phase pushes the sample through the column 2280 and to any connected detector.
The stroke of the pump section 102 , as illustrated in general in FIGS. 7 and 8 , is particularly illustrated in FIGS. 12A and 12B , wherein the stroke 1202 of the pump section 102 is illustrated between the maximum load position 502 , 1502 , 1710 , 1928 and the maximum injection position 602 , 1602 , 1802 , 2002 . The stroke 1202 may be 0.25 inches, or slightly smaller, or 0.75 inches, or slightly larger, or may be between, such as at 0.50 inches. As can be appreciated, the stroke 1202 and the diameter of the barrel 726 determine the volume of fluid transmitted during each load and injection cycle, which, by virtue of their values, are measured in microliters. Operation of the invention and the associated low flow rates are made possible by use of the integration of the pump section 102 and the valve section 104 , unlike conventional products.
Referring to FIGS. 7, 8, 9, 10, 11, 12A and 12B , operation of the integrated nano-scale pump and injection valve 100 is provided by the body 724 , the linear pump actuator 204 , and the integrated barrel-stator 716 . The linear pump actuator 204 includes a plunger-driving piston 712 connected to the plunger 706 . A plunger 706 , at least equal in length to the stroke 1202 and nearly-equivalent to the diameter of the interior chamber 702 , is attached to the end of the plunger-driving piston 712 . In the load position 502 , 1502 , 1710 , 1928 , the plunger 706 is at its maximum retraction within the elongate barrel 726 and defines the maximum volume which may be moved during the stroke 1202 . In the injection position 602 , 1602 , 1802 , 2002 , the plunger 706 is at its maximum displacement into the elongate barrel 726 . The volume displaced during the stroke 1202 between the maximum position associated with the loading 502 , 1502 , 1710 , 1928 and the maximum position associated with the injection 602 , 1602 , 1802 , 2002 is equal to the volume of the plunger 706 introduced into the elongate barrel 726 . The position of the plunger 706 in the barrel 726 and its extent during the stroke be determined with mechanical systems such as optical encoders, or others known in the art, and the maximum extent may be defined and operation limited by mechanical stops or limit switches.
Thus, the integral nano-scale pump and injection valve 100 includes a body having a pump section 102 and a valve section 104 where the body has a pump 708 in the pump section 102 and a valve 710 in the valve section 104 . The pump 708 functions linearly by using an elongate barrel 726 and a plunger 706 . As the barrel provides an internal chamber in which the plunger 706 moves, drawing or ejecting fluid from one end while the plunger 706 is moved from the opposing end, the elongate barrel 726 is characterized by an open proximal end, an open distal end, a length, and a sidewall, which define the interior chamber 702 . As detailed, the internal chamber 702 is adapted to receive a supply of mobile phase, and provides operation in connection with the plunger 706 by having an inner diameter sized to the plunger, an outer diameter sized to fit within the pump section and a wall thickness therebetween to provide sufficient strength. The plunger 706 , which has a substantially uniform cross-section, is slidably disposed within the interior chamber 702 and is sized to ensure effective operation during the load position 502 , 1502 , 1710 , 1928 and the injection position 602 , 1602 , 1802 , 2002 .
The present invention provides an integral nano-scale pump and injection valve 100 for high performance liquid chromatography which includes an integrated barrel-stator 716 , which has an elongate barrel 726 at a first end and a stator 302 , 1302 , 1712 , 1932 at a second end, a plunger 706 slidably disposed within an interior chamber 702 of the barrel 726 of substantially uniform cross-section, and a rotor 402 , wherein the pump 708 and valve 710 are switchable between a load position 502 , 1502 , 1710 , 1928 and a injection position 602 , 1602 , 1802 , 2002 . The circular rotor 402 has a surface adjacent the stator 302 and has a plurality of channels 404 , 406 , 408 , 1404 , 1406 , 1408 , 1410 in its surface and is rotatable with respect to the stator 302 , 1302 about a centerpoint between the load position 502 , 1502 , 1710 , 1928 and the injection position 602 , 1602 , 1802 , 2002 . The elongate barrel 726 portion of the integrated barrel-stator 716 includes an open proximal end, an open distal end, a length, and a sidewall defining the interior chamber 702 adapted to receive a supply of fluid and which has an inner diameter, an outer diameter, and a wall thickness. The circular stator 302 has an orifice 320 at its centerpoint and a first side and a second side such that the elongate barrel open distal end is aligned with the second side of the stator 302 at the centerpoint and the interior chamber 702 includes the orifice 320 . The pump 708 is therefore in communication with the valve 710 at the orifice 320 .
The nano-scale operation of the integrated nano-scale pump and injection valve 100 is made possible by integration of parts may be further augmented by sufficient and operable 360 zero-dead volumemicrometer fittings, and by material selection. Diamond-coated surfaces may be utilized where beneficial. The plunger 706 may be constructed of a work hardened super alloy, such as MP35N, a nickel-chromium-molybdenum-cobalt alloy providing ultra-high strength, toughness, ductility and high corrosion resistance—particularly from contact with hydrogen sulfide, chlorine solutions and mineral acids (nitric, hydrochloric, and sulfuric). Moveover, the nano-scale operation of the integrated nano-scale pump and injection valve 100 permits portability, such as being battery-operated, while being light weight, having low mobile phase consumption and generating low waste. Additionally, this system, designed particularly for capillary column use, does not employ a splitter, provides a substantial in operation. The integrated nano-scale pump and injection valve 100 can generate up to 110.32 MPa (16,000 psi) pressure, with a pump volume capacity of 24 μL, and a sample volume as low as 10 nL, or higher, such as 60 nL, can be injected As a result of the structures provided herein, the maximum and minimum dispensing volumetric flow rates of the integrated nano-scale pump and injection valve 100 are 74.2 μL/min and 60 nL/min, respectively. This may further be accomplished by providing the loop 506 of 5.08 cm×75 or 150 μm inner diameter stainless steel tubing to carry the mobile phase to the column during injection (dispensing).
The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof. | A combined pump-injector valve utilizing a single piece as the barrel of the pump and as the stator of the valve, thus eliminating any need for connections between a pump and a valve, and therefore the potential for high-pressure leaks or pressure reductions. The combined pump-injector valve permits injection of nanoliter-sized samples into a chromatographic column, which is sealed during loading of the sample and filling of the pump, such that complete analyses can be completed with microliters of mobile phase with nanoliters of a sample. | 5 |
BACKGROUND OF THE INVENTION
The present invention concerns a cabinet assembly, and in particular a cabinet adaptable for use with a removable partition panel having a door that is stored above the cabinet.
Cabinets including an over-the-top door are known and are often preferred over other cabinets because the doors do not strike objects within the cabinet, and further do not take up space within the cabinet when opened. Another benefit is that the top of the cabinet must stay free of clutter because the door prevents use of the space above the cabinet for storage purposes. Such cabinets and doors often use a sliding hinge arrangement, where a pair of hinges are attached to a top and front of the cabinet and a track is attached to a side of the door for both slidably and pivotally engaging the hinge. The door opens by sliding the door upwardly and/or outwardly until the door can be slid onto the top of the cabinet for storage in an open position. For example, see U.S. Pat. No. 3,771,847.
A problem is that these pivot/slide hinged doors can close with guillotine-like motion if the doors are prematurely released when partially open. This results in the doors moving vertically downwardly by gravity with a potentially unsafe speed and force unless proper care is used. Some cabinet manufacturers have conceived of alternatives to reduce the potential or likelihood of such accidental downward movement of the doors. However, the known alternatives are costly, include an unacceptable number of components, are mechanically too complex, and/or are difficult to assemble.
Also, racking and binding of doors can be problematic. When sliding the door between the opened and closed positions, doors may cant, thus binding the door against the cabinet itself or within the mechanisms attaching the door to the cabinet.
Therefore, an apparatus solving the aforementioned problems and having the aforementioned advantages is desired.
SUMMARY OF THE INVENTION
In one aspect of the present invention, a cabinet assembly includes a cabinet having a front opening, a door configured to close the front opening, sliding hinge structures, a follower, and a mating guide separate from the hinge structures. The sliding hinge structures operably support the door on the cabinet for pivotal and sliding movement between a closed position, in which the door covers the front opening, and an open position, in which the door is stored above the cabinet. The follower and mating guide operably attach an upper edge of the door to a front edge of the cabinet. The follower and the guide constrain the door to a pivotal movement as the door is initially opened in a manner so as to prevent a sliding guillotine-like movement while the door is in a partially opened position.
In another aspect of the present invention, a follower and guide are provided in a cabinet assembly having a cabinet and a door. The cabinet includes a front opening and a top panel. The door is configured to cover the front opening. The cabinet further includes hinges that pivotally and slidably mount the door to a front edge of the top panel. The door is movable between a closed position where the door covers the front opening, a pivoted forward/opened position where the door extends horizontally in front of the cabinet, and a stored forward/opened position where the door is located generally parallel to the top panel. The guide extends fore-to-aft in the top panel and is generally centrally located within the top panel and extends to the front edge thereof. The follower is provided on the door separate from the hinges and is both pivoted to the door and slidably engaged with the slide. The door pivots on the follower and the hinges when the door is moved between the closed position and the pivoted forward/opened position. Characteristically, the follower cannot slide when the door is initially pivoted from the closed position, thus preventing the door from moving with a guillotine-like movement when initially pivoted from the closed position. The follower slidably engages the guide when the door is slidingly moved on the hinges between the pivoted forward/opened position and the stored forward/opened position. Characteristically, the door cannot pivot on the follower, nor pivot on the hinges, when the door is slidingly moved from the stored/open position toward the pivoted/opened position. As a result, an over-the-top cabinet door is provided that substantially cannot be moved with a vertical guillotine-like motion as the door is closed.
In yet another aspect of the present invention, the cabinet assembly includes a cabinet, a door, and a door support mechanism. The cabinet is provided with a front opening and includes a top panel. The door is configured to close the front opening and includes a rear surface. The door support mechanism operably mounts the door to the cabinet and is configured to support the door for pivotal movement between a closed position, when the door covers the front opening, and a pivoted forward/opened position, when the door is pivoted open and extends forward of the cabinet. The door support mechanism is further configured to support the door for sliding movement between the pivoted forward/opened position and the stored/opened position where the door is located over the cabinet. The door support mechanism includes a first track and a first follower operably engaging the first track and defining a first axis of rotation and a first path. The door support mechanism further includes second tracks and second followers operably engaging the second tracks and defining a second axis of rotation and a second path. The first tracks and second followers are attached to one of the cabinet and the door. The second tracks and first followers are attached to the other of the cabinet and the door. The tracks and the followers are located so as the first and second paths extend in substantially perpendicular directions when the door is in the closed position, the first and second paths are coplanar and align when the door is between the pivoted forward/opened position and stored/opened position. The first and second tracks and first and second followers are further located so that the first and second axes are co-axially aligned only when in or between the closed position and pivoted forward/opened position, but are misaligned when in or close to the stored forward/opened position. The door is limited to a pivoting motion when the door is between the closed position and the pivoted forward/opened position and is limited to a sliding motion when the door is between the pivoted forward/opened position and the stored/opened position.
These and other features, advantages, and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a cabinet with an over-the-top door embodying the present invention, with the door in the closed position;
FIG. 2 is a perspective view of the cabinet with the door in the pivoted/open position;
FIG. 3 is a cross-sectional view of the cabinet taken along the line III--III in FIG. 1;
FIG. 4 is an enlarged fragmentary cross-sectional view of a follower and guide taken of area IV in FIG. 1;
FIG. 5 is an enlarged fragmentary cross-sectional view of a slot taken along line V--V in FIG. 4;
FIG. 6 is an enlarged fragmentary cross-sectional view of a modified follower and guide taken of area VI in FIG. 1;
FIG. 7 is an enlarged fragmentary cross-sectional view of a groove taken along line VII--VII in FIG. 6; and
FIG. 8 is an enlarged fragmentary cross-sectional view of another modified follower and guide taken along line VIII--VIII in FIG. 1.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
For purposes of description herein, the terms "upper," "lower," "right," "left," "rear," "front," "vertical," "horizontal," and derivatives thereof shall relate to the invention as oriented in FIG. 1. However, it is to be understood that the invention may assume various orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.
The reference numeral 10 (FIG. 1) generally designates a panel-mounted storage cabinet assembly embodying the present invention. The illustrated panel-mounted storage cabinet assembly 10 includes a cabinet assembly 11 formed by side panels 12, a top panel 13, and a bottom panel 14 that define a storage area 15. An over-the-top door 16 is mounted to the cabinet 11 for closing a front opening of the storage area 15. The door 16 is operably mounted to the cabinet 11 by a pair of track-and-hinge assemblies 17 and by a guide-and-follower assembly 18, so that the door 16 opens onto top panel 13 of the cabinet 11, as described below. Advantageously, the interaction of the track-and-hinge assemblies 17 and the guide-and-follower assembly 18 cause the door 16 to initially open with a pivoting motion, and then cause the door 16 to slide horizontally to a storage position over the cabinet assembly 11. By this arrangement, the door 16 is prevented from moving with a sudden guillotine-like motion when the door 16 is near the closed position, which is an advantage desired by some consumers, as discussed below.
Cabinet assembly 11 (FIGS. 1 and 2) is formed by side panels 12, top panel 13, and bottom panel 14 defining a storage area 15 that has a substantially rectangular shape. Cabinet assembly 11 also includes a back panel 30. The illustrated side panels 12, top panel 13, and bottom panel 14 are constructed of steel; however, it is contemplated that other appropriate materials may be used including, but not limited to, wood, aluminum, and durable plastics.
Side panels 12 (FIGS. 1-3) are each defined by a front edge 32, a rear edge 34, a top edge 36, and a bottom edge 38. Side panels 12 are each provided with a plurality of mounting hooks 40 along rear edge 34 for removably mounting the cabinet assembly 11 to a partition panel (not shown). Side panels 12 are provided with inwardly facing keyhole slots 27 and inwardly facing notches 28.
Top panel 13 is defined by front edge 42, rear edge 44, and side edges 46. Rear edge 44 of top panel 13 is provided with a rearwardly extending L-shaped rail 48 for rigidifying the cabinet assembly 11. Top panel 13 is further provided with hanging pins 29 that extend outwardly from side edges 46. Top panel 13 is attached to the side panels 12 by engaging the hanging pins 29 within the keyhole slots 27 of side panels 12.
Bottom panel 14 includes a front edge 68, a rear edge 68', and side edges 70. Bottom panel 14 includes a shelf 69 defining a forwardly facing notch 72 running along front edge 68 and a rear flange 72' defining a rear stop for the shelf. Bottom panel 14 is further provided with hanging pins 29 that extend outwardly from side edges 70. Bottom panel 14 is attached to side panels 12 by engaging the hanging pins 29 within the notches 28 of side panels 12. Other methods of attachment that are appropriate for the materials used to construct the cabinet assembly are envisioned.
Door 16 (FIGS. 1 and 2) defines a top edge 50, a bottom edge 52, side edges 54, a front surface 56, and a rear surface 58. The door 16 is mounted to the cabinet 11 for closing the storage area 15. Door 16 is operable between a closed position (FIG. 1), a pivoted forward/opened position (see FIG. 2, although in FIG. 2 the door is shown as having been slid rearwardly an inch), and a stored/opened position in which the door 16 is slid completely rearwardly such that it is positioned over the top panel 13 (not shown).
Door 16 is operably mounted to cabinet assembly 11 by track-and-hinge assemblies 17. Exemplary track-and-hinge assemblies 17 that can be used in the present invention are disclosed within U.S. Pat. No. 3,771,847 (Reissue Patent No. 28,994). Such assemblies are available in the industry.
The track-and-hinge assemblies 17 (FIG. 1) each include a stationary hinge member 19 attached to the top of panel 13, a pivot hinge member 20 that is pivotally attached to the stationary hinge member 19 by way of a hinge pin (not shown) defining a first axis of rotation, and a track 24 attached to the rear surface 58 of door 16 that slidably engages the pivot hinge member 20. More specifically, the sliding mechanism includes a first rail, a second rail, and a plurality of ball bearings seated therebetween (not shown). The first rail operably slides in a linear motion within the second rail.
The guide-and-follower assembly 18 (FIGS. 1 and 4) prevents the door 16 from being moved with a sudden guillotine-like motion when the door 16 is near the closed position. The guide-and-follower assembly 18 includes a slot 21 formed within top panel 13, and a guide member 22 that rearwardly extends from rear surface 58 of door 16. The slot 21 is centrally located within the top panel 13, extends through the entire thickness of top panel 13, and extends rearwardly from front edge 42 towards rear edge 44. However, the slot 21 may be located at any location along the top panel 13. The guide member 22 is provided a proximal end 25 that rearwardly projects from the rear surface 58 of door 16, and a distal end 26 for engagement under top wall 13. The illustrated guide member 22 (FIG. 4) is a bent bar that is curved at an approximate 90° angle; however, other angles that provide substantial contact between the guide member 22 and the top panel 13 can be used and still be within the scope of the present invention.
In operation, the door 16 (FIGS. 1, 2, 4, and 5) is pivotable between the closed position, the open/pivoted position, and the open/stored position. The guide member 22 prevents travel of the door in a linear motion along the tracks 24 of the track-and-hinge assemblies 17 until the door 16 has been pivoted to a substantially coplanar position with the top panel 13. The interaction of the track-and-hinge assemblies 17 and the guide-and-follower assembly 18 cause the door 16 to initially open with a pivot motion, and then allow the door 16 to slide horizontally to a stored position over the cabinet assembly 11. The door 16 is prevented from moving with a sudden guillotine-like motion when the door is near the closed position as a result of the contact between the guide member 22 and top panel 13. When in the closed position, the bottom edge 52 of door 16 is loosely seated within notch 72 of bottom panel 14, such that door 16 sits flush with front edges 32 of side panels 12.
An alternative embodiment to the guide and follower assembly 18 (shown in FIGS. 4 and 5) includes a groove 60 that is formed within slot 21 and extends laterally into top panel 13 (FIGS. 6 and 7). The groove 60 is defined by a top wall 62, a bottom wall 64, and an inner wall 66.
In operation, the distal end 26 of guide member 22 travels in a linear path within the groove 60. The door is prevented from moving with a sudden guillotine-like motion when the door 16 is near the closed position as a result of the contact of the guide member 22 with the top wall 62 of groove 60.
In yet another embodiment of the present invention (FIGS. 1 and 8), the guide-and-follower assembly 18 includes a slot 21 formed within top panel 16, a guide member 74, a set of pivot arms 76 which extend inwardly from door 16, and a pivot pin 78. Slot 21 is centrally located within the top panel 13 and extends rearwardly from front edge 42 towards rear edge 44. The slot 21 defines opposing flanges 86 within top panel 13. The flanges 86 are defined by a top surface 88, a bottom surface 90, and an inside surface 92. An "I" shaped guide member 74 is provided having a pair of laterally extending lower flanges 80, a pair of laterally extending upper flanges 82, and a pivot arm 84. Guide member 74 is located within slot 21, such that top panel 16 is positioned between the lower flanges 80 and the upper flanges 82 allowing guide member 74 to travel linearly along slot 21 without binding or rotating within slot 21. The pivot arm 84 of guide member 74 is pivotally connected to the set of pivot arms 76 by the pivot pin 78, thus defining a second axis of rotation. Guide member 74 is constructed of lubricious plastic or other suitable material.
In operation, the door 16 is pivoted between the closed position, the open/pivoted position, and the open/stored position. The guide member 74 prevents travel of the door in a linear motion along the tracks 24 of the track-and-hinge assemblies 17 until the door has been pivoted to a substantial coplanar position with top panel 13. Once the door 16 is pivoted to a coplanar position with top panel 13, the guide member 74 may travel along slot 21, thus allowing door 16 to be positioned above top panel 13.
In the foregoing description, it will be readily appreciated by persons skilled in the art that modifications may be made to the invention without departing from the concepts disclosed herein. For example, it is contemplated that the track-and-hinge assemblies 17 could be replaced with a slot (like slot 21) located in the door 16 and a follower/guide member (like guide member 22) located at a front edge of the top panel 13. Such modifications are to be considered as included in the following claims, unless these claims by their language expressly state otherwise. | A cabinet assembly includes a cabinet, a door, sliding hinge structures, a follower, and a mating guide. The cabinet is provided with a front opening. The door is configured to close the front opening. The sliding hinge structures operably support the door on the cabinet for pivotal and sliding movement between a closed position covering the front opening, and an open position uncovering the front opening and storing the door above the cabinet. The follower and the mating guide are separate from the hinge structures and operably attach an upper edge of the door to a front edge of the cabinet. The follower and guide constrain the door to a pivotal movement as the door is initially opened in a manner preventing a sliding guillotine-like movement when the door is initially opened. | 4 |
[0001] This application is a continuation-in-part and claims the benefit of priority of co-pending application U.S. Ser. No. 10/400,317 filed Mar. 27, 2003.
FIELD OF THE INVENTION
[0002] This invention relates to the production of carpets from staple fiber made from poly(trimethylene terephthalate).
BACKGROUND OF THE INVENTION
[0003] Carpet is generally constructed from the following components: the face yarn, which can be cut pile, loop pile, or a combination of the two and is formed from natural or synthetic fibers, a primary backing, a binding compound such as latex, and often a secondary backing. Synthetic fibers for use in carpet and other uses are formed by a process in which molten polymer is forced through tiny holes, or extruded, through a metal plate, or spinneret. After the filaments emerge from the spinneret, they are cooled, drawn, and texturized. Synthetic fibers can be extruded in different shapes or cross sections, such as round, trilobal, pentalobal, octalobal, or square, depending on the design and shape of the spinneret holes.
[0004] Carpet is generally made from either bulked continuous filament (BCF) or from staple fiber. BCF is continuous strands of synthetic fiber formed into yarn bundles. If a BCF yarn is desired, the extruded product containing the proper number of filaments for the desired yarn denier is wound directly. Staple fiber is short lengths of fibers which are cut from filaments (as opposed to BCF which is continuous filament). Staple fibers may be converted into spun yarns by textile yarn spinning processes and this generally requires three critical preparation steps—blending, carding, and drafting—prior to the spinning process.
[0005] U.S. Pat. Nos. 5,645,782, 5,662,980, and 6,242,091 describe a method for preparing BCF carpet yarn from poly(trimethylene terephthalate) by drawing the fiber from above its glass transition temperature to 200° C. using a draw assist such as hot pin or steam. A different method for preparing BCF yarns for making carpets is described in EP 0,745,711, U.S. Pat. Nos. 6,113,825, 6,254,961, and 6,315,934 using a two-stage draw. In U.S. Pat. No. 6,109,015, poly(trimethylene terephthalate) BCF yarn was prepared by heating the yarn to a temperature between its glass transition temperature and its crystallization temperature. The above methods involve extruding PTT into continuous filaments and then drawing the filaments on a set of feed rolls before using them to make carpet fibers.
[0006] Staple fibers have different properties than BCF fibers. Each has its advantages. Staple fiber, when constructed into a higher face weight carpet of >32 oz/yd 2 , has the advantage of giving a more luxurious look and feel than BCF carpets of comparable face weight. Other synthetic or natural staple fibers, such as poly(ethylene terephthalate), nylon, acrylic, polypropylene, silk, wool and cotton, can be blended with poly(trimethylene terephthalate) staple fibers to enhance carpet appearance, wear performance, and dyeing properties. These other fibers cannot be easily blended with BCF yarns. Therefore, it would be useful to be able to prepare staple fiber carpet yarn from poly(trimethylene terephthalate). The present invention provides a method to do so.
SUMMARY OF THE INVENTION
[0007] In one aspect, the present invention is directed to a process for the production of staple fibers from poly(trimethylene terephthalate) for conversion into carpets which comprises:
[0008] (a) extruding poly(trimethylene terephthalate) at a melt temperature of 240 to 280° C. into a fiber tow formed of fiber filaments having an undrawn filament denier of at least 25 denier,
[0009] (b) quenching the fiber tow such that the fiber tow has a crystallinity of less than or equal to 25%,
[0010] (c) prior to drawing, heating the fiber tow to temperature of 35° C. to 65° C.,
[0011] (d) drawing the fiber tow, and
[0012] (e) forming staple fibers from the drawn fiber tow.
BRIEF DESCRIPTION OF THE DRAWING
[0013] FIG. 1 is a plot comparing the crystallization half time of poly(trimethylene terephthalate) and polyethylene terephthalate measured with a differential scanning calorimeter.
[0014] FIG. 2 is a typical differential scanning calorimeter scan of extruded poly(trimethylene terephthalate) filaments prior to drawing.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The staple fiber preparation process of this invention is designed specifically for poly(trimethylene terephthalate), the product of the condensation polymerization of 1,3-propane diol and a terephthalic acid or ester thereof, such as terephthalic acid or dimethyl terephthalate. The poly(trimethylene terephthalate) may be derived from minor amounts of other monomers such as ethane diol and butane diol as well as minor amounts of other diacids or diesters such as isophthalic acid. Poly(trimethylene terephthalate) having an intrisic viscosity (i.v.) within the range of 0.8 to 1.1 dl/g, preferably 0.86 to 0.96 dl/g (as measured in a 50/50 mixture of methylene chloride and trifluoroacetic acid at 30° C.) and a melting point within the range of about 215 to about 235° C. is particularly suitable. It is preferred that the moisture content of the poly(trimethylene terephthalate) be less than 0.005 percent prior to extrusion. Such a moisture level can be achieved by, for example, drying polymer pellets in a drier at 110 to 180° C. with dehumidified air until the desired dryness has been achieved.
[0016] The poly(trimethylene terephthalate) is extruded through a spinneret into a plurality of continuous filaments at a temperature within the range of 240 to 280° C., preferably 250 to 270° C., and then cooled rapidly, preferably by contact with cold air, and then the tows are combined for drawing, crimping, and cutting into staple fibers. A spinneret is a metal disc containing numerous minute holes used in manufactured fiber extrusion. The melted polymer is forced through the holes to form the fiber filaments.
[0017] The fiber filaments have a denier prior to drawing the fiber filaments such that the fiber filaments may be drawn and formed into staple fibers useful for the preparation of carpets. The undrawn fiber filaments may have a denier of at least 25 denier, or at least 35 denier, or at least 45 denier, or at least 55 denier, or at least 65 denier. In an embodiment the undrawn fiber filaments have a denier of from 25 denier to 65 denier, or from 35 denier to 55 denier.
[0018] Directly after emerging from the spinneret, the fiber tow formed of the fiber filaments is quenched at a temperature of 14 to 25° C., preferably from 14 to 20° C. Preferred quenching methods include contact with cross-flow, inwards, or outwards radial-flow cold air. The flow rate of the cold air may range from 0.3 to 1.2 meters per second depending on the extrusion melt temperature, the number of extruded filaments, and the methods of cooling the filaments.
[0019] If the fiber tow is heated in a hot spin finish emulsion or hot water dip bath, the temperature of the emulsion or bath should be less than 50° C. in order to achieve the goal of controlling the crystallization which is discussed in more detail below. The emulsion or bath temperature is chosen such that the fiber tow does not crystallize significantly so that it becomes brittle for drawing. Usually this can be visually observed by a change in the fiber tow from translucent to opaque in undelustered PTT fibers. The opaque fiber tow will become too brittle for drawing.
[0020] In a process where the fiber tow does not go through a dip bath but instead is put through a series of rolls with hot water or spin finish emulsion sprays, the temperature of the spray should be less than 90° C. The spray temperature chosen will also depend on the number of sprays and the speed of the rolls. The temperature must be chosen such that the fiber tow is not cold crystallized and does not become brittle when it reaches the last roll prior to drawing.
[0021] Unlike poly(ethylene terephthalate), poly(trimethylene terephthalate) has a very fast crystallization rate. FIG. 1 compares the crystallization half time, t 1/2 , of the two polymers measured with a differential scanning calorimeter at different degrees of undercooling. The undercooling temperature is defined as the difference between the polymer's equilibrium melting point and the crystallization temperature. The equilibrium melting points of poly(ethylene terephthalate) and poly(trimethylene terephthalate) are 285° C. and 242° C., respectively. t 1/2 is the time required to reach 50 percent of the equilibrium crystallinity when the polymer is crystallized at a constant temperature. The lower the t 1/2 is, the faster the crystallization rate. Because of the very fast crystallization rate of poly(trimethylene terephthalate), the crystallinity of the extruded filaments should be controlled. The consequence of fast crystallization, if not properly controlled, will render the poly(trimethylene terephthalate) spun fiber tow difficult or impossible to draw into fibers. Even though poly(trimethylene terephthalate) is an aromatic polyester, it cannot be processed into staple fiber like poly(ethylene terephthalate) polyester because of the fast crystallization rate. The extruded poly(trimethylene terephthalate) filaments, prior to drawing, should have a crystallinity of less than or equal to 25%, preferably less than or equal to 20%.
[0022] Crystallinity of poly(trimethylene terephthalate) is measured herein by using a differential scanning calorimeter (DSC) at a heating rate of 20° C./min. The DSC scan of the extruded poly(trimethylene terephthalate) filaments should contain the following thermal features shown in FIG. 2 . The features are (i) a glass transition temperature, A, of 35 to 55° C.; (ii) a cold crystallization exotherm, B, of 50 to 80° C. (the peak temperature of exotherm B should always be greater than the glass transition temperature A by 5 to 35° C.); (iii) a heat of fusion of 1 to 30 cal/g; and (iv) an endotherm, C, with peak melting temperature of 220 to 235° C.
[0023] Crystallinity is defined by the following equation:
% Crystallinity=(Δ H c −ΔH B )×100%/Δ H f
where
[0024] ΔH c =Heat of fusion of endotherm C in cal/g
[0025] ΔH B =Heat of fusion of exotherm B in cal/g
[0026] ΔH f =Heat of fusion of 100% crystalline
[0027] poly(trimethylene terephthalate), and is reported by Gonzalez et al. in Journal of Polymer Science: Part B: Polymer Physics, Volume 26, pages 1397-1408, 1988, which is herein incorporated by reference, as 35±4 cal/g. Other methods for measuring crystallinity such as density, wide-angle X-ray diffraction, etc. may be used in lieu of the DSC method. Failure to control cold crystallization during processing of poly(trimethylene terephthalate) into staple fiber will cause the extruded filaments to become too brittle and will either result in excessive fiber breaks in the draw frame or the polymer will become impossible to draw into fibers at all.
[0028] The extruded poly(trimethylene terephthalate) filaments with controlled crystallinity can either be wound up into fiber packages or laid as loose tow of fibers in a tow can for subsequent drawing, crimping and cutting into staple fibers as a separate processing step, or the extruded filaments can be drawn, crimped, and cut into staple fibers as a continuous process.
[0029] In this invention, the preferred drawing temperature of poly(trimethylene terephthalate) ranges from 35° C. to 75° C. This can be achieved by either dipping the fiber tow in a water bath or by heating with hot godet. Typically, 0.2 to 2% by weight of lubricant is applied to the fibers to facilitate drawing. The lubricant can be applied in an emulsified form in the water bath or sprayed onto the filament tow before or after the first heated godet. Suitable lubricants include fatty esters, polyether copolymers which have an ethylene-oxide and/or propylene-oxide unit, nonionic surfactants including propylene-oxide and ethylene-oxide surfactants, and ionic surfactants such as sulfonic acid salts, phosphoric acid ester salts, and high molecular weight fatty acid salts.
[0030] The preheated fiber tows may then be fed to at least one set of pre-draw rolls, preferably at a temperature of 50 to 85° C., and preferably drawn at a draw ratio of 2.8 to 4.0. The drawn fiber tows may have a drawn filament denier of at least 10, or from 10 denier to 30 denier, preferably from 15 denier to 25 denier.
[0031] Next, the drawn tow can be further heated and then fed to a crimper roll which is operated at a pressure of 2 to 4 bar. Crimping is the process of imparting crimp to the fiber tow. This is important because it provides bulk to the staple fibers. It may be accomplished with the aid of steam or hot air at 120 to 200° C.
[0032] The fiber tows are next dried using conventional means, such as a hot air tunnel dryer operated at 130 to 180° C. Finally, the staple fiber is cut into short lengths, such as 1.5 to 10 inches, preferably 4 to 8 inches, and then baled. This is a common shipping and storage package into which these fibers are compressed.
EXAMPLES
Example 1
[0033] 500 lbs. Of poly(trimethylene terephthalate) polymer (PTT) pellets dried to a moisture level of <0.005% were extruded at 250° C. without drawing into a 56 denier per filament (dpf) unoriented yarns with 497 filaments and wound into packages. Forty-five packages of the of the extruded yarns were then combined for drawing, crimping, and cutting into staple fibers with a Neumag staple fiber line, Model 3466. The yarns first passed through a hot spin finish dip bath at 38° C. The spin finish used was 20% Lurol 6023 emulsion from G. A. Goulston Company. The final spin finish level on the fibers was 0.5 to 0.7% by weight. The yarns coated with spin finish were then fed into a series of pre-draw rolls at 77° C. and at a speed of 400 m/min., and drawn at a draw ratio of 3.43. When the spin finish dip bath temperature was >55° C., the filament crystallized in situ in the bath, turned opaque, caused excessive filament break in the drawing process, and reduced the draw ratio. When the filaments were allowed to further crystallize by prolonging the residence time in the bath or raising the bath temperature, they became too brittle and could not be drawn at all.
[0034] The drawn yarns were further heated with 70 psi steam prior to crimping. The crimper roll was operated at 3.1 bar and the crimper box pressure was 1.85 bar. The yarns were crimped with 12 crimps/inch with the aid of steam at 132° C. They were then dried at 130° C. in a 40 foot long hot air drying tunnel and cut into 7 inch long staple and baled.
Example 2
[0035] 6000 lbs. of PTT staple fibers delustered with 0.1% TiO 2 were made on a staple fiber line Neumag Model 3466. The dried polymer was first extruded into unoriented spun yarn with 41 dpf and a total of 483 filaments and collected as a fiber tow in a tow can. After relaxing in the tow can overnight, the fiber shrunk by about 20% and gave unoriented yarn with 54 dpf. The crystallinity of the yarn, measured by a differential scanning calorimeter (DSC), was 18%. The DSC showed a cold crystallization peak temperature of 67.5° C. and a glass transition temperature of 44° C. Fifty-seven tows of the spun yarns were combined for drawing, crimping, and cutting into staple fibers. The combined tows were passed through a hot spin finish (20% Milube 5494 from G. A. Goulston Company) dip bath at 37° C. The final spin finish on the fibers was 0.2 to 0.5%. The yarns were then fed into a series of pre-draw rolls at about 57° C. and drawn at 400 m/min. to a draw ratio of 3.6. The drawn yarns were further heated with 70 psi steam prior to crimping on a crimper roll operated at 3.1 bar and crimper box pressure of 4.2 bar. The yarns were crimped with 10 crimps/inch with aid of steam at 132° C. They were then dried at 160° C. in a 40-foot long hot air drying tunnel and passed through a finish bath (20% Milube NA29 from G. A. Goulston Company). The final finish on yarn was 1.9%. The yarn was then cut into 7 inch staple fiber and baled.
Properties of the Staple Fiber Denier per filament 17.5 Crimps per inch 10.5 Tenacity (g/den.) 2.1 Elongation, % 82% Fiber cross-section Trilobal with 1.5 Modification ratio
Example 3
[0036] Making PTT Staple Carpets
[0037] A 100 lb. of the PTT staple fiber bale of Example 1 was opened, carded, and spun into staple yarns in a typical stable spinning process. Two plies of the yarns were then twisted into 5.25×5.0 twists/inch yarn with 3.75 cotton count. The yarns were heat set in a Suessen heat setter at 185° C. They were tufted into ⅛ inch gauge 24 oz. and 30 oz. staple carpets with 9/16 inch pile height. The PTT staple carpets were dyed with disperse dyes at atmospheric boil without using a carrier.
[0038] Accelerated Floor Trafficking Test of PTT Staple Carpets
[0039] Specimens 9″×22″ were cut from both the length and width direction and fastened to the floor with the 22″ width perpendicular to the traffic flow. Pedestrians walked in fifty minute intervals. All specimens were vacuumed every hour before traffic was resumed. Multiple electronic counters were used to determine when the predetermined amount (20,000 cycles) of traffic had been applied. At the test's conclusion all specimens were vacuumed before removal from the floor with the last pass of the vacuum in the direction of the original pile. All specimens were allowed to recover at room temperature a minimum of 24 hours before grading by a panel of technicians. Specimens were individually rated using the Carpet and Rug Institute Reference Scale in which the samples are compared to pre-existing reference samples. Ratings were averaged and reported. The higher the rating is the better the expected performance is. The rating scales described the appearance change of the tested product.
[0040] Rating:
5—No change 4—Slight change 3—Moderate change 2—Significant 1—Severe change
[0046] The accelerated floor trafficking test is one that is commonly used in the industry as a good representation as to how the carpet resiliency would perform in service. A rating of at least 3 is required for the carpet mill to guarantee the product.
Accelerated Floor Trafficking Results Carpets Rating 24 oz. PTT staple carpet 4.5 30 oz. PTT staple carpet 4.0
Example 4
[0047] Preparation of PTT Carpets
[0048] PTT staple fibers from Example 2 were opened and 1.5% Goulston LPS400 lubricant and 3.5% water was applied to the fibers for carding. Sliver weight from the card was 700 g/yd. Drafting was done in three steps. Six slivers were used in the first and second drafts and three slivers were used for final drafting to give a sliver weight of 70 g/yd. They were then ring spun with a spindle speed of 4,500 rpm and twisted into yarn with 3.25 cotton count and 4.25 twist per inch. The yarns were Suessen heat set at 175° C., tufted into carpets with 32, 40, 50 and 60 oz./yd2 face weight, and dyed with disperse dye at atmospheric boil. The carpets had good bulk and excellent hand by touch compared to commercially available PET staple carpets. | This invention is a process for the production of staple fibers from poly(trimethylene terephthalate) for conversion into carpets which comprises: (a) extruding poly(trimethylene terephthalate) at a melt temperature of 240 to 280° C. into round, trilobal, delta, multi-lobal, or hollow cross section staple fiber tow, (b) quenching the fiber tow such that the undrawn filament tow has a crystallinity of ≦25%, preferably ≦20%, (c) prior to drawing, heating the fiber tow to temperature of 35° C. to 65° C., preferably between 35 and 55° C., to control crystallization, and (d) drawing the staple fiber tow into staple fibers. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to and is a continuation-in-part application of application Ser. No. 11/384,031, filed on Mar. 17, 2006, and which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a heat-shrinkable holder for securing articles, a package securing such articles using heat-shrinkable sheets, and a method of securing such articles using heat-shrinkable sheets.
BACKGROUND OF THE INVENTION
[0003] Articles such as beverage containers are often secured together using thermoplastic ring-type carriers. Some such carriers are sometimes known as “six-pack” carriers, although carriers for holding various numbers of containers have been used. Typically, such carriers comprise a flexible plastic, for example made from a low-density polyethylene. The carriers have openings formed smaller than the containers. The carriers are stretched over a suitably positioned group of the containers. When released, the openings conform to the sides of the containers, thereby unitizing the containers into a package.
[0004] The characteristics of the plastics used in such stretch-loaded carriers are such that it can be difficult to remove individual containers or groups of containers together due he the amount of force required. In particular, the complexity of manufacture and use of such carriers increases substantially with the number of containers being held by the carrier. Also, the carriers used are generally small strips, located around the top portion of the containers, for example along a ridge at the top of a can. The plastics are thus not susceptible to carrying printed indicia, and are typically not sufficiently transparent or translucent so as to allow the view of any indicia on the containers being held. Also, a fair amount of force and complicated machinery is required to stretch the carriers so as to place them over the containers. Therefore, although stretch-loaded carriers have been used for many years, various drawbacks do exist with regard to stretch-loaded carriers.
[0005] In conventional shrink-wrapping, a load is fed to a wrapping zone in which a shrink-wrap film is placed on the load in some fashion. The film is cut into pieces or sheets before or during the placement on the load. Typically, the film makes a complete revolution around the load so that two cut ends overlap. The load and film are then passed into a heating tunnel causing the film to shrink and compress against the load. Typically, the film is cut into sheets large enough to allow for some overlap between edges when placed on the load. During the heating process, the edges may therefore be sealed together forming a unitary package.
[0006] Groups of articles such as containers have been wrapped with shrink-wrap in such fashion previously. However, due to the nature of conventional shrink-wrapping, the film extends only around the outside of the articles. Therefore, individual articles may not be removed without compromising the integrity of the entire package, and individual articles may contact each other while packaged, possibly leading to damage. To address issues such as thee, sometimes, articles are even placed in a first container such as a box or a stretch wrap carrier, and then shrink-wrapped. Such packaging adds cost and wastes material.
[0007] Accordingly, an improved holder for articles such as containers, an improved package of unitized containers, and improved methods of packaging would be welcome, addressing one or more of the above drawbacks of conventional packaging technology, and/or other disadvantages of currently available technology.
SUMMARY OF THE INVENTION
[0008] According to certain aspects of the invention, a heat-shrinkable holder is disclosed for securing a plurality of articles, the holder including a first sheet formed of heat-shrinkable material and having a pre-shrinking length, and a second sheet formed of heat-shrinkable material substantially equal to the first sheet pre-shrinking length, the second sheet being joined to the first sheet. The first sheet and the second sheet are joined so as to create at least two openings therebetween, each of the openings sized larger than one of the articles, the first and second sheets being heat-shrinkable to an extent to shrink the openings sufficiently to secure two of the articles together into a unit. Various options and modifications are possible.
[0009] For example, the holder may include two of the first sheets and two of the second sheets joined together in a unit, and the holder may be configured with a plurality of openings arranged in to rows and/or with six openings for securing six articles in a two-by-three arrangement.
[0010] The articles may be arranged so that they do not contact each other directly when secured. At least one of the first or second sheets may include printed indicia relating to the article. The first and second sheets are may be joined via at least one of heating or an adhesive. The openings may have an internal circumference larger than an outer circumference of the article to be placed therein. The holder may be formed in a group of separable holders formed sequentially from the first and second sheets, and perforations may be provided for separating adjacent holders formed from the first and second sheets. The holder may further include a handle extending from at least one of the first and second sheets, and the articles may be containers. At least one of the first or second sheets may include perforations configured for allowing an article to be removed from the unit after heat shrinking.
[0011] According to other aspects of the invention, a package of articles is disclosed including a plurality of articles, a first sheet formed of heat-shrinkable material and having a pre-shrinking length, and a second sheet formed of heat-shrinkable material substantially equal to the first sheet pre-shrinking length, the second sheet being joined to the first sheet. The first sheet and the second sheet are joined so as to create at least two openings therebetween, each of the openings sized larger than one of the articles, the first and second sheets being heat-shrinkable to an extent to shrink the openings sufficiently to secure two of the articles together into a unit. As above, various options and modifications are possible.
[0012] According to other aspects of the invention, a package of articles is disclosed including a plurality of articles, and at least four sheets of heat-shrunken material having substantially equal pre-shrinking lengths, the sheets being joined at a plurality of discrete joinder portions thereby forming a plurality of openings arranged in at least two rows, each opening sized to secure an article therein, the heat-shrunken material and articles thereby forming a unitary heat-shrunken package configured with a plurality of articles arranged in at least two rows. As above various options and modifications are possible.
[0013] For example, the package may be configured so that the articles are drawn together in two perpendicular directions by the shrinking, and/or with the openings arranged in a two-by-four arrangement or a two-by-three arrangement. The package may be configured so that articles do not contact each other directly when secured.
[0014] According to certain other aspects of the invention, a heat-shrinkable holder is disclosed for securing a plurality of articles, the holder including at least four sheets of heat-shrunken material having substantially equal pre-shrinking lengths, the sheets being joined at a plurality of discrete joinder portions thereby forming a plurality of openings arranged in at least two rows, each of the openings sized larger than one of the articles, the sheets being heat-shrinkable to an extent to shrink the openings sufficiently to secure two of the articles together into a unit having at least two rows of articles. Again, various options and modifications are possible.
[0015] According to other aspects of the invention, a method of packaging articles is disclosed including providing a first sheet of heat-shrinkable material, the first sheet defining a plurality of pre-shrinking holder lengths; providing a second sheet of heat-shrinkable material, the second sheet defining a plurality of pre-shrinking holder lengths substantially equal to those of the first sheet; joining the first sheet to the second sheet at discrete joinder portions spaced along the first and second sheet so as to form a plurality of openings, each opening located between each adjacent pair of joinder portions, the joinder forming a plurality of holders each having the pre-shrinking holder lengths of the first and second sheets; inserting an article into each of the openings; and heating the first and second sheets to shrink the first and second sheets thereby forming a unitary package of the sheets and the inserted articles. Various options and modifications are possible with this method as well.
[0016] For example, the method may further include cutting the first and second sheets to form an article holder of the pre-shrinking holder length before the heating step. Also, the method may further include providing two of the first and second sheets of heat-shrinkable material. The method may involve joining the first and second sheets so as to form a plurality of openings arranged in two rows. Also, the method may include forming perforations in at least one of the first or second sheets to allow removal of individual articles. The joining step may be achieved by at least one of applying an adhesive or applying heat. The method may further include opening the openings before the inserting step. The opening step may include one of blowing a gas, applying suction, or using one or more mechanical fingers to open the openings. The articles may be containers, and the first and second sheets are sized so that during the heating step the articles are drawn together in two perpendicular directions. The method may include providing a handle for the package.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1A is a perspective schematic view of one possible line configuration of a line for manufacturing heat-shrinkable holders according to certain aspects of the present disclosure.
[0018] FIG. 1B is a perspective schematic view of one possible line configuration of a line for placing articles in heat-shrinkable holders so as to create a package.
[0019] FIG. 2A is a perspective view of one example of an empty heat shrinkable holder.
[0020] FIG. 2B is a perspective view of the heat shrinkable holder as in FIG. 2A , with articles located within the openings of the holder, before heat-shrinking.
[0021] FIG. 2C is a perspective view of the holder and articles as in FIG. 2B , after heat-shrinking
[0022] FIG. 3 is a top view of a heat-shrunken holder as in FIG. 2C , with the articles removed for clarity.
[0023] FIG. 4A is a perspective view of an alternate heat-shrunken holder and articles, as in FIG. 2C , wherein the holder includes perforations for assisting in removing individual articles.
[0024] FIG. 4B is a perspective view of an alternate heat-shrunken holder and articles, as in FIG. 2C , wherein the holder has a smaller vertical dimension.
[0025] FIG. 4C is a perspective view of an alternate heat-shrunken holder and articles, as in FIG. 2C , wherein the articles are held by two holders as in FIG. 4B .
[0026] FIG. 4D is a perspective view of an alternate heat-shrunken holder and articles, as in FIG. 2C , wherein the holder is smaller and centrally located vertically along the articles.
[0027] FIG. 4E is a perspective view of an alternate heat-shrunken holder and articles, as in FIG. 2C , wherein the holder includes printed indicia thereon.
[0028] FIG. 4F is a perspective view of an alternate heat-shrunken holder and articles, as in FIG. 2C , wherein printed indicia on the articles may be seen through at least a portion of the holder, and including an optional handle.
[0029] FIG. 4G is a perspective view of an alternate heat-shrunken holder and articles, as in FIG. 2C , wherein the holder extends along the entire side surfaces and at least partially onto the top and bottom surfaces of the articles.
[0030] FIG. 5A is a perspective view of an alternate heat-shrunken holder and articles, as in FIG. 2C , wherein the holder holds more articles in a two by six arrangement.
[0031] FIG. 5B is a perspective view of an alternate heat-shrunken holder and articles, as in FIG. 2C , wherein the holder holds more articles in a three by four arrangement.
[0032] FIG. 6A is a perspective view of an alternate empty heat-shrinkable holder.
[0033] FIG. 6B is a perspective view of the heat shrinkable holder as in FIG. 6A , with articles located within the openings of the holder, before heat-shrinking.
[0034] FIG. 6C is a perspective view of the holder and articles as in FIG. 6B , after heat-shrinking.
[0035] FIG. 7 is a top view of a heat-shrunken holder as in FIG. 6C , with the articles removed for clarity.
[0036] FIG. 8A is a perspective view of an alternate heat-shrunken holder and articles, wherein the holder includes an optional handle.
[0037] FIG. 8B is a perspective view of an alternate heat-shrunken holder and articles, wherein the holder includes an alternate optional handle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, and not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a third embodiment. It is intended that the present invention include these and other modifications and variations. In discussing various embodiments, like or similar reference numerals are used below with like or similar parts of various embodiments.
[0039] As described herein, a shrink-wrapping material may be used to form holder for articles. Preferably, the holder is formed from at least two sheets of the heat shrinkable material for holding at least one row of articles. However, more sheets and various configurations could be employed. For example, three sheets could be used for two rows of articles, as in a conventional six-pack (two by three) arrangement. If desired the sheets may have different properties, and all sheets need not be heat-shrinkable. For example, one of two sheets may be heat shrinkable, or two of three sheets may be heat shrinkable, as discussed below. The non-shrinkable sheets may be provided for structural stability (for example, use as a center sheet or a handle), for carrying printed indicia, or for other purposes. The present disclosure also includes various packages for holding articles, and methods for creating such holders and packages.
[0040] FIGS. 1A through 3 disclose one possible method for manufacturing such holders and creating such packages. The example used therein is for a conventional six-pack of cans. It should be understood also that the present invention has utility with various articles, not just containers, and with various containers, not just cans, as shown.
[0041] More particularly, FIG. 1A is a perspective schematic view of one possible line configuration of a line for manufacturing heat-shrinkable holders, an example of which is shown in FIG. 2A . As shown in FIG. 1A , line 10 a includes film supply rolls 12 , 14 , 16 at one end and take up roll 18 at the other. Between the rolls lies a forming zone 20 , where film from rolls 12 , 14 , 16 is formed into holders for articles.
[0042] Forming zone 20 includes spreaders 22 and sealers 24 . As shown in FIG. 1A , spreaders 22 are rods inserted between films 26 , 28 , 30 to create openings 32 . At the rightmost end of forming zone 20 , spreaders 22 a are being inserted between the films 26 , 28 , 30 , closely adjacent to film 28 . Spreaders 22 generally travel along direction D with the films once inserted. By the time spreaders 22 a move along direction D and reach the position of spreaders 22 b , spreaders 22 a will have moved outward from film 28 in the directions of arrows O. Simultaneously sealers 24 are sealing films 26 and 30 to film 28 . As illustrated, sealers 24 are heat-sealing devices, although other devices could be used to seal the films together, such as adhesive applying devices. Sealers 24 a hold and seal the films 26 , 28 , 30 together thereby forming joinder portions while spreader 22 a moves to the position of spreader 22 b . Then, another sealer 24 (not shown) will contact films 26 , 28 , 30 and seal them together to create another opening (not shown) upstream from opening 32 a.
[0043] As shown, each opening 32 is formed by one spreader 22 and two sealers 24 . It is also possible to form adjacent openings utilizing common sealers 24 between them. Therefore, only one sealer set 24 could be provided above and below the films between openings 32 a and 32 b , for example. Such sealer set could make a single point contact, thereby changing the shapes of the openings a bit to widen them, or could extend along direction D between openings 32 a and 32 b and seal the entire area between sealers 24 b and 24 c . All openings 32 need not be the same size. For example, the outermost openings may be larger than the center opening in a common six pack arrangement (not different sizes of openings being formed in FIG. 1A ). Thus, the loops of film 26 may have different sizes along a given holder. Making the central loops smaller may help pull the resulting package together more tightly during heat-shrinking.
[0044] Spreaders 22 and sealers 24 should remain in contact with films 26 , 28 , 20 long enough to reliably seal them together to form a blank 42 . The amount of contact time may vary according to line speed, sealer type (heat versus adhesive), sealer temperature, film properties, etc. FIG. 1A shows only one of the possible arrangements of spreader 22 and sealer 24 contact ranges.
[0045] Spreaders 22 and sealers 24 may be moved laterally, vertically, pivotally, or some combination, into and out of place, by suitable motors, drives, etc. For example, the spreaders and sealers may be mounted on a rotating device that places the elements in the upstream position, drives them in direction D, removes them in the downstream position, and then returns them to the upstream position. A programmable logic controller, motors and sensors can be used to control such movement as desired. Various guide rollers 34 , which may be driven or idlers, may be provided to guide the films thorough line 10 a . The films may be paid off rolls 12 , 14 , 16 at different speeds to account for the different lengths of films used in forming zone 20 . That is, more of films 26 and 30 is needed than of film 28 , as configured in FIG. 1A . Some or all of the film supply rolls 12 , 14 , 16 may therefore be driven, and other flow controlling structures such as gimballing rollers or the like may be used.
[0046] Perforating devices 36 , 38 , and 40 , schematically shown in FIG. 1A , may also be employed, if desired. As shown, perforating device 36 perforates all three films 26 , 28 , 30 , so as to allow for division of the films into separate holders. Perforating device 38 perforates film 26 , and perforating device 40 perforates film 30 . These latter perforations allow individual articles to be removed from the formed holders later. Perforating devices 36 , 38 , 40 may be linearly or rotationally moving knife devices. Controllers and servomotors and the like may cause the perforating devices to operate at desired times, to achieve perforations where desired in the films.
[0047] Take up roll 18 may be eliminated if desired, and line 10 a of FIG. 1A may lead directly to line 10 b of FIG. 1B . Alternatively, take up roll 18 may be replaced by a box or the like, with the film material being fan folded in place. Use of a box may provide easier splicing and changeout opportunities, while use of a roll may provide more secure control and denser packaging. Either is an acceptable modification of that shown.
[0048] FIG. 1B is a perspective schematic view of one possible line configuration of a line 10 b for placing articles in heat-shrinkable holders so as to create a package. As stated, lines 10 a and 10 b may be merged into one line, eliminating the need for use of take up rolls 18 , if desired. As shown, roll 18 supplies blank 42 material, comprising in FIG. 1B adjacent six-pack holders 100 separated by perforations 44 formed by device 36 . Blank 42 travels to an opening station 46 , where an opener such as a blower 48 , a suction device 49 , or a mechanical finger device 50 , or some combination of both opens the openings 32 of holders 100 . Articles 102 are then loaded into openings 32 (see arrow L). As shown, six cans are vertically moved into the openings 32 . However, the articles may instead be vertically stationary and the blank material may be placed over the articles from above or below, if desired. Blank 42 is then separated at perforations 44 by a divider 52 to form individual loaded holders. It is possible to not make the perforations where illustrated in line 10 a , and to simply cut the blank 42 when indicated in line 10 b . The loaded holders 100 are then passed into a heating device 54 such as a heat tunnel. Any of the films within the holders 100 that are heat-shrinkable will then contract, forming unitary packages 200 .
[0049] If desired, packages 200 may be further combined in various ways, such as by heat sealing or shrinking or adhesives to create still larger packages. For example, two six packs could be combined to create a twelve pack (see FIG. 5B ); four six packs could be combined to create a case, etc. Also, packages 200 may be connected vertically.
[0050] It should be understood that the representations of FIGS. 1A and 1B are not intended to be to scale and are schematic illustrations only. It should also be understood that the line 10 a need not use three films; any number of films greater than two may be employed with modification of the line. For example, two films could be used to create a linear collection of articles. Four or five films could be used to create a grouping of articles three across (as opposed to two across). Modifications to the heat sealing and possible use of adhesives, whether heat activated, heat cured, contact adhesives, or otherwise, could be used to create larger arrays of openings and larger packages.
[0051] FIGS. 2A-2C show enlarged views of a holder 100 and articles 102 , in this case cans. FIG. 2A shows a holder 100 , as separated along perforations 44 . It would be possible to separate the holders 100 before filling them with articles 102 , if desired. FIG. 2B shows six articles 102 in openings 32 of holder 100 before heat shrinking FIG. 2C shows unitized package 200 after heat shrinking FIGS. 2B and 2C illustrate that heat-shrinking can beneficially cause the articles 102 to be pulled together in two perpendicular dimensions, that is along the line of central film 28 and perpendicular to it. This shrinking helps ensure a solid unitized package 200 . Adjacent articles 102 all have film between their sides to the will not “clank” into each other, possibly damaging the articles during handling or shipping. This is especially useful if the articles are containers, such as glass bottles. Also, the heat shrinking maintains the articles in a solid formation, as opposed to certain container holders where the bottoms of the containers may swing out from the tops when moved about. Again, the disclosed holder 100 prevents such swinging, and potentially prevents damage resulting therefrom. Articles are unlikely to slip out of holder 100 due to the tensions caused by heat shrinking, making them easy to handle and carry. Also, the resulting unitary package can be readily stacked and or used in displays. Because each article is packaged in its own heat-shrunken opening, individual containers are readily removed without damaging the integrity of the rest of the package.
[0052] FIG. 3 is a top view of a heat-shrunken holder 100 as in FIG. 2C , with the articles removed for clarity. As seen, shrinking along the central line followed by film 28 helps draw the six containers in to form a unitized shape, with all adjacent containers having at least one buffering piece of film between them for protection. As can be seen, the amount of film used from films 26 and 30 is much greater than from central film 28 , and the outermost openings 32 are larger than the central openings. Based on the size and shape of the articles to be packaged, the operation of forming zone 20 can be readily designed so as to achieve a desired resulting configuration. The amount of film used for outer films 26 and 30 may thus be two times more than that of film 28 , and could be as much as four or more times greater as well, depending on the application.
[0053] FIG. 4A is a perspective view of an alternate package 210 including heat-shrunken holder 110 and articles 102 , as in FIG. 2C , wherein the holder includes additional perforations 112 for assisting in removing the individual articles. Perforations 112 are made by devices 38 and 40 in line 10 a , as discussed above. As shown, two perforations 112 are provided for each article 102 , but more or fewer may be provided. Also, the area of film 114 between the perforations may be bonded to the article 102 , if desired, for example, by an adhesive that could be applied to the film or article, or activated during heat shrinking or otherwise. Thus, the holder 100 would provide a label for the article 102 via film piece 114 , eliminating the necessity of separately labeling the article. (See FIG. 4E below for printed indicia on film).
[0054] FIG. 4B is a perspective view of an alternate heat-shrunken package 220 including holder 120 and articles 102 , as in FIG. 2C , wherein the holder has a smaller vertical dimension. If desired, holder 120 may thus cover less of the articles, but the protective abilities may be lessened at some point with a smaller holder. Also, the holder may be placed around a bottle neck or along a can ridge, if desired.
[0055] FIG. 4C is a perspective view of an alternate heat-shrunken package 230 including holder 120 and articles 102 , as in FIG. 2C , wherein the articles are held by two holders 120 as in FIG. 4B . Use of two smaller holders 120 requires less film than holder 100 and addresses protection issues noted above, although assembly of the package 230 may be more complex.
[0056] FIG. 4D is a perspective view of another alternate package 240 including a heat-shrunken holder 120 and articles 102 , as in FIG. 2C , wherein the holder is smaller and centrally located vertically along the articles. Central location of a smaller holder may also address protection issues while reducing material used.
[0057] FIG. 4E is a perspective view of an alternate package 250 including a heat-shrunken holder 150 and articles 102 , as in FIG. 2C , wherein the holder 150 includes printed indicia 152 thereon. The printed indicia 152 may be individual elements or a common element across the various articles or across multiple packages, as desired. Thus all article labeling or supplemental article labeling may be accomplished via the package holder portion.
[0058] FIG. 4F is a perspective view of an alternate package 260 including a heat-shrunken holder 160 and articles 102 , as in FIG. 2C , wherein printed indicia 162 on the articles 102 may be seen through at least a portion of the holder, and including an optional handle 164 . In this embodiment, the outer films 26 and 30 would be at least partially translucent or transparent in whole or part. If such a handle 164 were provided, it could be part of a film, such as central film 28 as shown, or an entirely separate piece attached in some way, such as via heat or adhesive. Handle 164 could need to be made of a more robust and/or less or non-shrinkable film or other material, depending on the size and weight of the package.
[0059] FIG. 4G is a perspective view of an alternate package 270 including heat-shrunken holder 170 and articles 102 , as in FIG. 2C , wherein the holder extends along the entire side surfaces and at least partially onto the top and bottom surfaces of the articles. Thus, as shown, the articles 102 are substantially wrapped and secured in three dimensions using holder 170 .
[0060] FIG. 5A is a perspective view of an alternate package 280 including a heat-shrunken holder 180 and articles 102 , wherein the holder holds articles in a two by six arrangement. Thus, it should be understood that various arrangements of articles is possible. For example, as further shown in FIG. 5B alternate package 290 includes a heat-shrunken holder 190 and articles 102 , wherein the holder holds articles in a three by four, twelve-pack arrangement. Such arrangement can be achieved in various ways, and in various steps as mentioned above. As shown herein, the package 290 is essentially equivalent to two side-by-side six pack packages 200 , with an added film layer 292 therebetween. Layer 292 could be applied via heat and/or adhesive. Alternatively, the entire twelve article holder 190 could be constructed in one pass on a modified version of line 10 a.
[0061] FIGS. 6A-6C show enlarged views of an alternate holder 300 and articles 302 , in this case bottles. Holder 300 is made from four sheets of film, 324 , 326 , 328 , 330 . Holder 300 may be formed from a blank holding a plurality of such holders, separable along perforations, such as perforations 44 discussed above. Separation of holders 300 results in two edges 322 at each end of the holder. As shown, holder 300 has eight openings 332 for receiving the articles 302 , although as discussed above, practically any number could be employed. Other openings 333 are created by the manufacturing process, but these are not necessarily sized to accept articles 302 , or at least articles of the same size. FIG. 6B shows eight articles 302 in openings 332 of holder 300 before heat shrinking FIG. 6C shows unitized package 400 after heat shrinking. As with FIGS. 2B and 2C above, heat-shrinking can cause the articles 302 to be pulled together in two perpendicular dimensions, helping ensure a solid unitized package 400 . Adjacent articles 302 all have film between their sides, as above, and each article is again packaged in its own heat-shrunken opening so that individual containers are readily removed without damaging the integrity of the rest of the package.
[0062] Holder 300 beneficially includes sheets of substantially equal length between edges 322 . Such equal sheet length allows holder 300 or a blank of multiple holders to lie flat or be readily rolled. In some applications, such abilities may be desirable, as compared to the holders described above.
[0063] It should be understood that although holder 300 is illustrated as having four sheets and eight openings, various different sizes are possible. For example, holder 300 could have two sheets holding a linear grouping of articles, or could have six or eight sheets, holding wider groupings.
[0064] FIG. 7 is a top view of a section through heat-shrunken holder 300 , with the articles removed for clarity. As seen, shrinking helps draw the eight containers in to form a unitized shape, with all adjacent containers having at least one buffering piece of film between them for protection. Since the amount of film used from films 324 - 330 is somewhat equal, the resulting package is somewhat symmetrical.
[0065] Based on the size and shape of the articles to be packaged, the operation of forming zone as shown in FIG. 1A and the filling zone in FIG. 1B can be readily modified to form holder 300 . For example, an even number of film supply rolls could be used, and the spreaders and sealers could be arranged as needed to form the desired configuration. It would be possible to first join two films to form an initial blank having one row of openings for articles, and then to join two or more of those blanks so as to create a package having more than one row. It would also be possible to join the films using a heat sealer while joining the blanks using an adhesive, or vice versa. The ultimate processes and machinery will depend on the desired package shape.
[0066] FIGS. 8A and 8B show two modifications to package 400 including handles. In FIG. 8A , package 410 includes a handle 464 , similar to that shown above. Handle 464 may extend from one of the sheets forming holder 300 ′ or may be an added sheet. In FIG. 8B , handle 564 of package 420 is attached to an outer sheet of holder 300 ″. Handle 564 may be attached at any location via heat sealing or adhesive. Either handle may be made of shirnkable or nonshrinkable plastic or other materials, as desired. Handle 564 may also extend further around package for a more secure hold, if desired.
[0067] Various types of films may be used for the holders' films and handles, such as commercially available heat-shrink films, such as polyethylene (LLDPE, LDPE, HDPE), PVC, polypropylene, styrene copolymer, or the like. The ultimate material selected and its properties can be selected to achieve the needs of the size, shape, weight, and number of the articles being packaged, the method of shipment, sale and use, etc.
[0068] Therefore, it should be understood that the types of holders, packages, and articles utilized with the teachings of the present disclosure should not be limited to those embodiments shown herein. It should also be understood that features of the various embodiments above may be recombined in other ways to achieve still further embodiments within the scope of the present invention. | A heat-shrinkable holder is disclosed for securing a plurality of articles. The holder may include a first sheet formed of heat-shrinkable material, and a second sheet formed of heat-shrinkable material and joined to the first sheet. The first sheet and the second sheet each have a substantially equal pre-shrinking length, and are joined so as to create at least two openings therebetween. Each of the openings is sized larger than one of the articles. The first and second sheets are heat-shrinkable to an extent to shrink the openings sufficiently to secure two of the articles together into a unit. Various modifications and additions are possible, including use of more than three sheets, providing for the reading of printed indicia on the articles or holder, providing a handle. Numerous orientations and collections of articles are possible. Related packages including a holder and articles are also disclosed, as well as related methods of manufacture of the holder and package. | 1 |
This application is the U.S. national phase of international application PCT/IB01/02253 filed Nov. 28, 2001, which designated the U.S., which in turn claims priority from application PCT/IT00/00532 filed on Dec. 19, 2000.
FIELD OF THE INVENTION
This invention relates to a modulator for modulating sample fractions in a capillary column during a gas chromatographic analysis.
The modulator according to the present invention can be designed for a traditional gas chromatographic apparatus in order to enhance the sensitivity by narrowing the peaks when placed directly in front of the detector or to focus the injected analytes when placed directly after the injector. However, it con also specially designed for comprehensive two dimensional gas chromatography.
STATE OF THE ART
The comprehensive two dimensional gas chromatography, also called comprehensive 2D GC, or GCXGC, is a gas chromatographic technique in which the sample is first separated on a conventional normal-bore high-resolution capillary GC column in the programmed temperature mode. All of the effluent of this first column is then focused in a large number of extremely narrow (<100 ms) and adjacent fractions at regular, short intervals and subsequently injected onto a second capillary column, which is short and narrow to allow for very rapid separations. GCxGC can be interpreted as to exist of two GC systems coupled in series by means of a so-called modulation system (FIG. 1 ). The first GC is a conventional capillary GC system, including a conventional injector; the second is a fast GC, which is about 50 times faster than the first one. This is accomplished by using a short and narrow-bore column to provide very narrow peaks with peak widths at baseline of 100-200 ms. The modulation system provides the correspondingly narrow injection pulses in such a way that no sample is lost during the transfer between the chromatographic dimensions. In this way the comprehensive GCxGC technique permits to obtain a separation power considerably larger than that of conventional capillary gas chromatography, together with an improved sensitivity, a better peak identification and other advantageous features.
As previously said, in order to carry out said GCxGC it is necessary to operate a so-called modulation system between the first and second capillary column in order to retain and focus the narrow fractions of the effluent of said first column and inject the some at intervals onto said second column.
The most widely used modulators are of the thermal type, wherein a thermal action on a column length is used to trap and release the fractions to be injected in the second column.
The known heated modulators use an intermediate, thick film modulation capillary to trap (parts of) the eluting analytes from the first column by means of phase-ratio focusing. Heat is applied to thermally desorb the analytes from the thick film stationary phase in order to re-inject the narrow chemical pulses into the second column. FIG. 2 presents this phase-ratio focusing and thermally desorption process in four steps.
In the first paper describing the comprehensive GCxGC technique, by Liu and Phillips [Z. Y. Liu, J B. Phillips, J. Chrom. Sci., 1991, 29,227-231] and in the Phillips patent [U.S. Pat. No. 5,196,039] a dual-stage metal-coated capillary with a thick film of stationary phase, connected with the outlet of the first column, but placed outside the oven, was employed as a modulation system. Sequentially the two parts of the metal coated capillary were resistively heated to desorb the analytes trapped due to the lower temperature of the modulation column and its thick stationary phase film. This system appeared not to be robust enough for long use and introduced limitations in the lower temperature of the oven housing of the two columns (as the minimum temperature of the oven should be in this case at least 100° C. higher than the temperature of the modulator which is kept close to the ambient one).
A more sophisticated heated desorption system was described and made commercially available by Ledford et al. [J. B. Phillips, R. B. Gaines, J. Blomberg, F. W. M. van der Wielen, J. M. Dimandja, V. Green, J. Granger, D. Patterson, L. Racovalis, H. J. De Geus, J. De Boer, P. Haglund, J. Lipsky, V. Sinha, E. B. Ledford, J. High Resolut. Chromatogr., 1999, 22, 3-10], and Phillips and Ledford patent [U.S. Pat. No. 6,007,602) mainly consisting of a slotted heater moving along the thick film capillary (sweeper) within the gas chromatographic oven.
However, this system too shows drawbacks, mainly due to the movement of the slotted heater in the close vicinity of the tiny capillary, which causes an easy breakage of the column and a limit of the oven maximum temperature.
In order to render more efficient the fraction trapping and eliminate the necessity of a special thick film capillary length, inserted between the first and second column as well as to remove the limitations related with the maximum oven temperature, so called cryogenic or cooled modulators were introduced.
These modulators, consisting of a cold trap moving sequentially forward and backwards along the inlet portion of the second capillary column (the cooling medium sweeps an upstream length of the second column), cryogenically trapping and focusing (parts of) the analytes as they elute from the first column on the first section of the second column itself [R. M. Kinghorn, P. J. Marriott, J. High Resolut. Chromatogr., 1998, 21,620-622]. When the cryogenic system moves away from the zone in which the analytes were trapped, the surrounding GC-oven air quickly heats up the trapped analytes remobilising them for re-injection in the remaining part of the second column. This cryogenic trap, focus and re-injection process is schematically presented in FIG. 3 .
The major drawback of this system is the very frequent breakage of the portion of the fused silica capillary column where the cold trap is moving due to ice formation between the cold trap and the column.
Apart from the mechanical differences between the heated and cooled modulators, there are also some differences in their applicability. In the heated modulators a difference in temperature of at least 100° C. is necessary between the oven and the sweeper, to remobilize the analytes from the thick film capillary that holds the retained fraction. The maximum temperature to which this capillary can be heated up, i.e. the maximum allowable temperature of its stationary phase, determines the maximum operation temperature of the sweeper.
The maximum temperature of the column oven will be therefore limited to 100 C. below the sweeper temperature and this introduces strong limitations in the application range covered by such systems. This limitation does not exist with the cooled moving modulator, the maximum operation temperature of the oven can be much higher as it is limited only by the maximum operating temperature of the two separation columns themselves.
The common characteristic of the thermal modulators as they have been described, however, is the fact that both techniques use a heating/cooling device that moves across a close distance around a fragile fused silica capillary column. Even very accurate (and rather tedious) tuning of these moving devices and their short distance to the capillaries, frequently leads to breakage of the tiny, and fragile capillaries.
Ledford [E. B. Ledford, C. Billesbach, J. High Resol. Chromatogr., 2000, 23, 202-204] introduced a modification of its heating sweeper, by applying a cooling jet of CO 2 on the heating arm. However, this system and the cryogenic system as previously illustrated show all drawbacks of the modulators having movable parts within the oven and moreover the continuous jet of CO 2 tends to create ice formations on the column which involves, breaking possibilities and hindering of fraction release.
Ledford (E. B. Ledford, presented on the 23 rd Symposium on Capillary Gas Chromatography , Riva del Garda, Italy, June 2000) recently proposed a two-stage liquid nitrogen/heated air let modulator with no moving parts. Two cooling and two heating jets spot-cool and heat a very short section of the second column to trap/focus and re-inject the modulated fractions. The two cooling jets of the two-stage jet modulator alternately spray liquid nitrogen directly onto the inlet part of the second column for trapping/focusing. Two jets with heated gas alternately heat up these spots to remobilize the analytes for re-injection as very narrow pulses.
The heating jets were necessary, since the temperature of the cooled sections of the second column could reach temperatures as low as 190° C.
Liquid nitrogen is not easily available at every laboratory and needs bulky insulation when transported through tubes. Moreover, the use of liquid nitrogen may create problems due to ice formation within the oven and in particular on the jet nozzles which may such hinder or even stop the release of liquid nitrogen. Moreover, since the hot air jet must have a temperature at least 100° C. above the oven temperature and very high air jet temperature cannot be reached for reasons of column integrity (maximum temperature of fused silica columns is 350° C.), this limits the maximum temperature of the oven and the range of applications covered by such systems.
OBJECTS OF THE INVENTION
The object of the present invention is now to provide a modulator for GC or GCxGC which optimises the analytes treatment in a conventional GC system and overcomes the drawbacks of the presently known modulators for GCxGC, in particular with reference to those connected with the mobile modulators (sweepers) and with the use of liquid nitrogen and hot air jets in the Ledford modulator with no moving parts.
DESCRIPTION OF THE INVENTION
The main feature and further features of the modulator according to this invention are reported in claim 1 and respectively in the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more deeply described with reference to the accompanying drawings, wherein:
FIG. 1 is a scheme of the GCxGC system.
FIG. 2 is a scheme of the known heating modulation system (sweeper).
FIG. 3 is a scheme of the known cryogenic modulation system.
FIG. 4 is a scheme of a modulator according to the present invention.
FIG. 5 is a detail of the jet configuration of the modulator of FIG. 5 .
FIG. 6 is a chromatogram obtained by means of a GCxGC separation of C 8 through C 18 with a modulator according to the present invention.
FIG. 7 is a chromatogram obtained by means of a GCxGC separation with a modulator according to the invention and showing the shape of the modulated n-C 14 peaks.
FIG. 8 is a scheme of a modulator according to the present invention when applied to a conventional GC system.
FIG. 9 represents two chromatograms showing the effect of peak sensitivity enhancement.
FIGS. 10 a and 10 b are diagrammatic representations of an alternative embodiment of the jet configuration, respectively in front view and side view.
FIG. 11 is a diagrammatic end view of another alternative embodiment of the jet configuration.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, FIG. 1 diagrammatically shows the components of a known GCxGC system, preferably housed in a single oven. FIG. 2 shows a scheme of the heating modulation process, in which the fraction eluting from the first column is trapped at the upstream end of the thick film of the modulation capillary (phase trapping) (step 1 ); when the heating sweeper comes in correspondence of this capillary upstream end, the heat effect releases the fraction (step 2 ) and transports the same along the thick film capillary, while a further fraction is trapped at the capillary upstream end (step 3 ).
When the sweeper reaches the second column, the first fraction is released on the same, while the further fraction is still trapped at the modulation capillary upstream end (step 4 ).
FIG. 3 schematically shows the cryogenic modulation process, wherein a cooling medium cools an upstream length of the second column. In correspondence of the cooling medium the fraction is trapped by thermal action and then released when the cooling medium is removed.
FIG. 4 is a scheme of a GCxGC system with a modulator according to this invention. The system comprises, in a GC oven 8 , an injector 1 , a first column 2 and a second column 6 which are connected at 3 according to a well known technique. The second column 6 ends in a detector 7 .
On an upstream length 9 of the second column 6 two jets 4 A and 4 B operate alternatively and at a suitable frequence, which are fed, through corresponding valves 5 A and 5 B, by a source of liquid CO 2 10 so that two parts of the capillary length 9 are directly cooled alternating in order to trap and focus the fraction, whereafter they are remobilized by the heat of the surrounding oven air. The opening time of each valve is preferably the same for all valves and half the cycle time, while the opening and closure of the valves are carried out in sequence to cover a cycle time in the order of 0.1 to 30 seconds. It is to be noted that the opening time of said valves could also be different and that this opening time may vary from about 0.1 to about 30 seconds.
The CO 2 jets in FIG. 5 consist of two electrical-driven two-way valves 5 A, 5 B that open and close the liquid-CO 2 line alternating through two pieces of 40 mm long, 0.8 mm ID capillaries 11 A/ 11 B, coupled to the nozzles ( 12 A, 12 B), 50 mm long 0.5 mm ID capillaries. In order to force as much CO 2 from the outlet of the jets to touch the column, the outlets have been modified to form a slit, 0.04 mm wide and 3 mm long, in parallel above the capillary. To prevent ice formation onto the outside of the jets at oven temperatures below about 100° C., they have been inserted in a 12 mm diameter brass socket to increase the heat capacity.
An alternative embodiment of the jet configuration is shown in FIGS. 10 a , 10 b and 11 , wherein, instead of the slit, the outlet is constructed by inserting a series of seven capillaries in a row between the same brass half blocks. More detailedly, as shown in FIGS. 10 a and 10 b , each brass block 20 houses a stainless steel capillary 21 , for instance having {fraction (1/16)}″ OD and 0.7 mm ID, said capillary 21 being connected through a related valve 15 , to the CO 2 source 10 . Within the end of capillary 21 are inserted for instance seven capillaries 22 placed according to what is shown in FIG. 11 and fixed preferably by a ceramic glue or soldering 23 , which is able to withstand temperatures of up to 400° C. In the shown example the capillaries have the following dimensions: length 35 mm, OD 0.23 mm, ID 0.11 mm and their free portions are aligned so to run in parallel with the secondary GC column 9 so that an optimum heat exchange is enabled by generating a “curtain” of expanding CO 2 .
The axes of the outlet openings of the capillaries 22 are placed 0.4 mm apart, so that the total length of the nozzle again is 3 mm. Of course, the above stated number and dimensions of capillaries can be changed at will.
The above stated construction allows to decrease the consumption of CO 2 and optimize the effectiveness of the throttling process at the nozzle outlet of the cryogenic jets.
As the liquid CO 2 expands at the outlet of the nozzles, the throttling process cools the departing gas through the Joule-Thompson effect. Since this gas is sprayed directly onto the second column length 9 at the prevailing flow, the column quickly cools down to about 100° C. below the oven temperature. Closing the valve will immediately stop the cooling process and the surrounding air from the stirred oven will heat up the short cooled section of capillary (about 10 mm) momentarily to oven temperature. The time required to heat the capillary column from cryogenic to oven temperature is only 13 ms for a normal 100 μm column (15 μm polyimide and 80 μm fused silica walls).
The length 9 of the second column in which the modulation takes place, is stretched and secured between two Valco unions 13 mounted on a bracket 14 . The stretching is necessary in order to avoid vibration of the column caused by the rather intense flow of cold CO 2 that is sprayed onto the column. The unions are mounted onto two bonds of 1 mm thick, resilient steel in order to compensate for the difference in thermal expansion of the steel bracket and the fused silica column.
A simple timing device that generates the 24 DC voltages for valve switching controls the modulation process. Modulation times shorter than 0.3 seconds can be established.
In order to test the performance of the modulator according to the invention, a gas chromatograph was used with a split/splitless injector and a Flame Ionisation Detector capable to produce a digital signal sampled at 200 Hz rate. The first dimension column 30 m×0.32 mm ID was coated with methylsilicon polymer, 0.25 microns film thickness. It was coupled through a press-fit connector to the second is column 1.5 m×0.10 mm ID, which was coated, with 0.1 μm BPX50 (SGE International, Ringwood, Australia). The flow was set to 1.0 mL/min through a column head pressure of 170 kPa helium. The columns were temperature programmed from 50° C., 4 min isothermal, 2° C./min to 300° C.
The main functions of the modulator are twofold: focusing small fractions from the effluents of the first column into narrow pulses and re-injection of these pulses into the remaining part of the second column. To judge the performance of the modulator, it is sufficient to measure or calculate the bandwidth of the injected pulses. To judge the performance of the dual jet modulator, a series of n-alkanes (C 8 through C 18 , see FIG. 6 ) was separated. From calculations of the peaks modulated from n-C 14 (see FIG. 7 ), the peak widths are σ=30 ms, which is better than second dimension peaks previously reported in the literature for known modulation systems (sweeper and cryomodulators). The injection bandwidth appeared to be σ<10 ms, which is also better than the injection bandwidths of the known sweeper and cryo modulators.
According to what stated above, the jet modulator of this invention is very simple in construction and easy to install and maintain. Its control is performed by simply switching one, two or more valves, so that no movable part are foreseen within the oven, thus preventing any column breakage due to movement of the previously known movable modulators.
Moreover, it has been ascertained that the ability of the modulator according to the invention to focus the trapped first dimension fractions into narrow pulses is superior to that of the modulators known, tested and described in the prior art.
It is to be finally noted that the present modulator, when designed with one liquid CO 2 jet only, can act as an injection focusing device and/or as a peck narrowing and then a detector sensitivity enhancing device in a conventional one-dimensional GC system. This configuration is depicted in FIG. 8 , where a capillary column 2 is conventionally housed in an oven and connected with an injector 2 and a detector 3 . A jet of liquid CO 2 issued by a source outside the oven and controlled by a valve, placed outside the oven, con be foreseen to impinge on a column portion respectively directly after the injector (position A) and/or immediately before the injector (position B).
When in position A, the CO 2 jet allows to focus the injected analytes, while when in position B the jet enhances the sensitivity of the detector by narrowing the peaks.
This is confirmed by the chromatograms of FIG. 9 , comparing the detector response under the some conditions respectively without sensitivity enhancement (CO 2 jets in position A and B not operative) and with sensitivity enhancement (CO 2 jet in positron A not operative and CO 2 jet in position B operative). A series of low concentration impurities in a main component are shown in the chromatograms of FIG. 9 , wherein the upper chromatogram shows the main peak together with a series of low concentration impurities in the conventional way, where the lower chromatogram shows how these impurities are collected by means by the single liquid CO 2 jet in position B (at the time of valve on) and released as a series of sharp peaks (at the time of valve off) at increased peak intensities. | This invention relates to a modulator for use in gas chromatographic analysis, adopted for alternatively trapping and releasing fractions of solutes in a length of a capillary column within a chromatographic oven, characterized in that it comprises at least one nozzle placed to spray at least one jet in at least one corresponding place along said capillary column length, said nozzle(s) being connected each to a source of liquid CO 2 via a related valve, and means for alternatively opening said valve(s) for a predetermined time, to cause a jet of liquid CO 2 to impinge for said predetermined time on said column place and to leave the oven atmosphere to heat said column place after said predetermined time. The modulator can be used in a conventional GC system or in a two dimensional GC system, for modulating the analytes fed to the second capillary column. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority based on U.S. Provisional Application Ser. No. 60/406,713 for “Managing and Controlling User Applications with Network Switches”, filed Aug. 28, 2002, the disclosure of which is incorporated here by reference in its entirety.
BACKGROUND
The present invention relates to network switching, and more particularly to Layer 2 through Layer 7 switching.
This invention relates to uses for network switches, and more particularly to filters and policies for managing and controlling user applications using network switches.
The OSI (Open System Interconnection) Model is an ISO standard for worldwide communications that defines a networking framework for implementing protocols in seven layers. Control is passed from one layer to the next, starting at the applications layer in one station, proceeding to the physical layer and back up the hierarchy.
The layers are defined as:
Applications Layer 7 provides interface to end-user processes and standardized services to applications.
Presentation Layer 6 specifies architecture-independent data transfer format, encodes and decodes data, encrypts and decrypts data, compresses data.
Session Layer 5 manages user sessions and reports upper-layer errors.
Transport Layer 4 manages network layer connections and provides reliable packet delivery mechanism.
Network Layer 3 addresses and routes packets.
Data Link Layer 2 frames packets and controls physical layer data flow.
Physical Layer 1 interfaces between network medium and network devices. Also defines electrical and mechanical characteristics.
SUMMARY OF THE INVENTION
The present invention provides methods and apparatus, including computer program products, for processing data packets in a computer network, the data packets including information from one or more of Layers 2 through 7 of the OSI model.
In one aspect the invention is directed to a computer network. The computer network includes a multiport network device and a computer executing a software application. The multiport network device receives data packets to be transported using the computer network and the network device stores one or more authorized network descriptors. A software application generates data packets to be transported to the computer network through the network device. The software application registers a network rights descriptor with the network device and inserts the network rights descriptor in each generated data packet. The network device is configured to discard data packet, if the network rights descriptor in the data packet does not match an authorized network rights descriptor and to process the data packet if the network rights descriptor in the data packet matches an authorized network rights descriptor.
Implementations of the invention can include one or more of the following features. The network device can store one or more authorized network descriptors. The network descriptors can be stored in a known location connected to the computer network and the network device can be configured to retrieve authorized network descriptors from the known location. The network device can be configured to retrieve authorized network descriptors from an authentication server. The network device can store one or more user defined packet policies and it can be configured to perform an action from a user defined packet policy that matches the network rights descriptor. The network device can be configured to route the data packet using a layer 2-3 switch. The network rights descriptor can include an application rights descriptor, a content rights descriptor and an enterprise rights descriptor. The network rights descriptor can be encrypted. The network device can be configured to process the data packet at wire speed. The network device can also be configured to block the discarded data packets from utilizing the computer network, redirect the discarded data packets, and log the discarded data packets.
In another aspect, the invention is directed to a computer network including a first multiport network device and a second multiport network device. The first multiport network device receives data packets to be transmitted using the computer network. The first network device inserts a local network descriptor in each data packet transmitted by the first network device. The second network device receives data packets from the computer network and the second network device stores one or more authorized local network descriptors. The second network device is configured to discard the data packet if the local network descriptor in the data packet does not match an authorized local network descriptor and to process the data packet of the local network descriptor in the data packet matches an authorized local network descriptor.
Implementations of the invention can include one or more of the following features. The one or more authorized network descriptors can be stored in the second network device. The authorized network descriptors can be stored in a known location connected to the computer network and the second network device can be configured to retrieve the authorized network descriptors. The second network device can be configured to retrieve the authorized network descriptors from an authentication server. The second network device can store one or more user defined packet policies and it can be configured to perform an action from a user defined packet policy that matches the network rights descriptor. The second network device can be configured to route the data packet using a layer 2-3 switch. The network rights descriptor can be encrypted. The first network device can be configured to process the data packet at wire speed. The second network device can be configured to process the data packet at wire speed. The second network device can be configured to block discarded data packets from utilizing the computer network, redirect discarded data packets, and log discarded data packets. The second network device can be configured to strip the local network descriptor before processing the data packet, if the data packet has a destination external to the computer network.
In another aspect, the invention is directed to a method for storing one or more authorized network descriptors at a multiport network device. The data packets are generated at a software application, and the data packets are transmitted to the computer network through the network device. The software application inserts a network rights descriptor in each generated data packet. The network device receives input identifying the network rights descriptor as an authorized network rights descriptor. If the network rights descriptor in the data packet matches an authorized network rights descriptor, the data packet is processed at the network device. If the network rights descriptor in the data packet does not match an authorized network rights descriptor, the data packet is discarded.
The invention can be implemented to realize one or more of the following potential advantages. Marking locally generated packets using a local network descriptor allows local packets to be distinguished from spoofed packets. Identification of locally generated traffic provides greater security from unauthorized utilization of the network and protects against unauthorized network traffic. Application rights descriptors can be used to allow only authorized applications to utilize the network, and to prevent spoofing of authorized applications. Application rights descriptors can also be used to enforce software license agreements, enforce copyright restrictions, prevent illegal copies of applications from running on the network, and limit the number of users for a software application. Content rights descriptors can be used to enforce a set of rights associated with the content by preventing unauthorized content from utilizing the network. Enterprise rights descriptors can be used to implement enterprise-specific policies for network utilization. One implementation of the invention can provide all of the above advantages.
The details of one or more implementations of the invention are set forth in the accompanying drawings and the description below. Further features, aspects, and advantages of the invention will become apparent from the description, the drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a conceptual block diagram of a data packet 100 including a network rights descriptor.
FIG. 1A illustrates an IP header included in the data packet.
FIG. 2 is a conceptual block diagram of a user workstation connected to a local area network.
FIG. 3 is a flow diagram illustrating a method for preventing unauthorized utilization of the network by marking packets using a local network descriptor.
FIG. 4 is a flow diagram illustrating a method for preventing unauthorized applications from utilizing the network.
Like reference numbers and designations in the various drawings indicate like elements.
DETAILED DESCRIPTION
FIG. 1 is a conceptual block diagram of a data packet 100 including a network rights descriptor 105 . The network rights descriptor 105 can be inserted in a known location in the data packet. The network rights descriptor 105 can also be inserted in a reserved or unused portion of the packet header. The network rights descriptor 105 can be used to identify data packets that are authorized to use network resources. The network rights descriptor 105 can also be used to identify the originator of the data packet, including the identification of locally generated data packets. The network rights descriptor 105 can include an application rights descriptor 110 , a content rights descriptor 115 , and an enterprise rights descriptor 120 .
The application rights descriptor is used to include information regarding a software application, device, or network appliance generating the data packet. The application rights descriptor can include an application signature inserted by the software application, where the application signature uniquely identifies the software application. Application signatures can also include information identifying a user or a workstation generating the data packet, date and time when the data packet was generated, and license information for the software application. To ensure the legitimacy of the application signature the application signature can be encoded and optionally encrypted and created dynamically at the time the application is first installed or each time the application is run. In one implementation, the application descriptor includes license information for the software application generating the data packet, and the license information is used to enforce the terms of a software license agreement for the software application (e.g. a maximum number of users running the software application at any time). The license information can also be used to only allow data packets generated by a software application having a valid license to use network resources. In an alternate implementation, the application rights descriptor includes information identifying a storage device at the user workstation that was used to generate the data packet, and only data packets originating from authorized storage devices are permitted to use network resources. The information identifying the storage device used to generate the data packets can be used to prevent a user from attaching a portable storage device (e.g. a portable hard drive, or a ZIP drive) to a user workstation and transporting data contained in the portable storage device using network resources.
The content rights descriptor is used to include information in the data packet that is specific to digital information contained in the data packet. The content rights descriptor identifies the type of content, e.g., text, graphics, audio, video, electronic documents, computer program instructions, and other data or information, and a set of associated rights. Each right in the set specifies one or more permitted actions for the data packet that can be authorized using that right. Optionally, the set of rights can specify conditions on performing the permitted actions. For example, a data packet containing a video clip can be associated with a content rights descriptor that specifies viewing rights. The viewing rights can specify the user or the workstation that can be used to view the video clip. Optionally, conditions on the viewing rights can specify, e.g., a limited time period, or a limited number of times for viewing the video clip. The viewing rights can also restrict the user receiving the video clip from transmitting the video clip to another user, and this restriction can be enforced using the content rights descriptor.
The enterprise rights descriptor is used to include enterprise specific information in the data packet. The enterprise rights descriptor can include information identifying an origin of the data packet. For example, the enterprise rights descriptor can be used to identify the copyright owner and the software licensee of the software application that generated the data packet, the patent owner and licensee of the user workstation used to generate the data packet, the copyright owner and the licensee of the operating system running on the user workstation used to generate the data packet, and the end-user of the application software used to generate the data packet. Alternatively, the enterprise rights descriptor can include information operable to determine if the data packet is a native packet that originated within an enterprise network, or if the data packet is a foreign packet that originated outside the enterprise network. The enterprise rights descriptor can also be used to specify and manage network bandwidth allocated to the data packet. For example, the enterprise rights descriptor can specify a bandwidth allocation for the data packet, a maximum or a minimum bandwidth allocation for the data packet, and a priority for the data packet.
FIG. 2 illustrates a conceptual block diagram of a user workstation 200 connected to a local area network 220 . The local area network 220 is connected to the Internet 285 through a router 280 . The user workstation 200 can be connected to a number of devices using the local area network 220 , e.g., printers 225 , storage devices 230 , and other workstations 235 . A configuration server 245 and an authentication server 250 can also be connected to the network 220 . A software application 205 , running on the user workstation 200 , generates data packets to be transmitted using the network 220 and receives data packets from the network 220 . The devices connected to the network 220 can transmit data packets to the software application 205 using the network 220 . The software application 205 transmits and receives data packets through a network interface 210 in the user workstation 200 . The network interface 210 connects the user workstation 200 to the network 220 through a multiport network device 215 . The network device 215 has three or more ports, and is dedicated to communicating data packets between the ports. Each port of the network device can transmit and receive data packets. The network device 215 can be a network switch, multi-layer switch, or a router. The network device is not a general purpose computing device. Techniques for implementing a multi-layer switch are described in U.S. application Ser. No. 10/445,293, titled “Switch for Local Area Network,” to Sean Hou, William R. Ge, Daniel Yin Yung Ching, Keith M. Andrews, Christopher H. Claudatos, and Magnus B. Hansen, filed on May 22, 2003, which is incorporated by reference herein.
A second user workstation 260 is connected to the local area network 220 through a multiport network device 275 . A software application 265 , running on the user workstation 260 , generates data packets to be transmitted using the network 220 and receives data packets from the network 220 . The software application 265 transmits and receives data packets through a network interface 270 in the user workstation 260 . The network interface 270 connects the user workstation 260 to the network 220 through the multiport network device 275 .
FIG. 3 is a flow diagram illustrating a method for preventing unauthorized utilization of the network 220 by marking packets using a local network descriptor. The local network descriptor is a predefined network rights descriptor 105 , or one of a set of predefined network descriptors 105 , used to identify the locally generated packets. The local network descriptor is inserted in the known or reserved portion of the packet header, or in a portion of the data packet other than the packet header. In one implementation, the data packet includes an IP header 130 ( FIG. 1A ). The Type of Service (ToS) field 135 ( FIG. 1A ) of the IP header, also referred to as the Differentiated Services Code Point (DSCP), is typically not used. A part of the ToS field 135 or the entire ToS field 135 can be used to insert the local network descriptor. In one implementation, six bits of the ToS field are used to insert the local network descriptor. The local network descriptor can be inserted by the software application 205 generating the data packet, the network interface 210 transmitting the generated data packet, or the network device 215 receiving the generated data packet from a trusted network interface 210 . The local network descriptor can be encoded and optionally encrypted using a predefined encryption algorithm. In one implementation, the network device 215 inserts the local network descriptor in all data packets received or transmitted through a physical port on the network device 215 , thereby marking these data packets as known packets.
Referring to FIG. 2 , data packets are transmitted from user workstation 200 to user workstation 260 . The data packets are generated by the software application 205 and transmitted through the network device 215 , using the network 220 . The data packets are received by the network device 275 and communicated to the software application 265 . The network device 215 inserts local network descriptor in the data packet and before transmitting the data packet through the network 220 .
The data packets are received at the network device 275 (step 300 ), and the local network descriptor is compared to a list of authorized local network descriptors (step 305 ). If the local network descriptor is encrypted using a predefined encryption algorithm, the network device 275 decrypts the local network descriptor in step 305 . A list of authorized local network descriptors, specified by a user or network administrator, is used to specify data packets authorized to utilize the network 220 . The list of authorized local network descriptors can be stored in the network device 215 , or it can be stored on some other device connected to the network 220 , e.g., the configuration server 245 . The network device 215 can also use an authentication server connected to the network 220 , e.g., the authentication server 250 , or a remote authentication server that is not directly connected to the network 220 to determine whether the local network descriptor is an authorized local network descriptor. If the local network descriptor is not an authorized local network descriptor (“no” branch of decision step 310 ), the data packet is discarded or redirected for further processing. In one implementation, discarded data packets are redirected to applications running on the network device 215 . In an alternative implementation, discarded data packets can be redirected to a specific port for logging, reporting, and surveillance.
In order to enhance network security the local network descriptor can be stripped from data packets being transmitted to a destination outside the network 220 , e.g., the Internet 285 , or before the data packets are presented to the software application 265 . Stripping the local network descriptor prevents entities outside the network 220 from observing and copying the local network descriptor to potentially generate spoofed packets. If the local network descriptor included in the data packet is an authorized local network descriptor (“yes” branch of decision step 310 ), the method determines if the local network descriptor should be stripped from the data packet (step 320 ). If the local network descriptor should be stripped (“yes” branch of decision step 320 ), the data packet is processed (step 330 ) after stripping the local network descriptor (step 325 ). If the local network descriptor does not have to be stripped (“no” branch of decision step 320 ), the data packet is processed as received (step 330 ). In one implementation, a local network descriptor inserted by a device can only be stripped by a receiving device of the same type as the inserting device, e.g., a receiving network device 215 can only strip local network descriptors inserted by a network device 215 , and a receiving network interface 210 can only strip local network descriptors inserted by a network interface 210 .
FIG. 4 is a flow diagram illustrating a method for preventing unauthorized applications from utilizing the network 220 . The method requires that software applications 205 utilizing the network 220 insert an application descriptor in data packets generated by the software application 205 . In one implementation, a part of the ToS field 135 ( FIG. 1A ) or the entire ToS field 135 can be used to insert the application descriptor. In one implementation, six bits of the ToS field are used to insert the application descriptor. In one implementation, the software applications 205 pre-register with the network device 215 and provide information required by the network device 215 to locate the application descriptor in the data packet. Pre-registration can also provide other information needed by the network device 215 to extract information from the application descriptor, e.g., whether the application descriptor is encrypted, and the format of the information contained in the application descriptor. In an alternative implementation, the network device 215 has the required information for all software applications 205 authorized to run on the network 220 and pre-registration is not required.
In FIG. 4 , the data packets are received at the network device 215 (step 400 ), and the network rights descriptor 105 is inspected (step 405 ) to determine if the network rights descriptor 105 is an authorized application rights descriptor (step 410 ). If the application rights descriptor is encrypted using a predefined encryption algorithm, the network device 215 decrypts the application rights descriptor before inspection. A list of authorized application rights descriptors, specified by a user or a network administrator, can be used to specify applications authorized to utilize the network 220 . The list of authorized application rights descriptors can be stored in the network device 215 . The network device 215 can retrieve the list of authorized application rights descriptors from another device, and store the retrieved list either persistently or temporarily. The list can be stored on some other device connected to the network 220 , e.g., the configuration server 245 . The network device 215 can also use an authentication server connected to the network 220 , e.g., the authentication server 250 , or a remote authentication server that is not directly connected to the network 220 to determine whether the application rights descriptor is an authorized application rights descriptor. If the application rights descriptor is not an authorized application rights descriptor (“no” branch of decision step 410 ), the data packet is discarded or redirected for further processing. In one implementation, discarded data packets are redirected to applications running on the network device 215 . In an alternative implementation, discarded data packets can be redirected to a specific port for logging, reporting, and surveillance.
The application rights descriptor can be stripped for data packets being transmitted to a destination outside the network 220 or before the data packets are presented to a software application 205 . Stripping the application rights descriptor prevents entities outside the network 220 from observing and copying the application rights descriptor to potentially generate spoofed packets. If the application rights descriptor included in the data packet is an authorized application rights descriptor (“yes” branch of decision step 410 ), the method determines if the application rights descriptor should be stripped from the data packet (step 420 ). If the application rights descriptor should be stripped (“yes” branch of decision step 420 ), the data packet is processed (step 430 ) after stripping the application rights descriptor (step 425 ). If the application rights descriptor does not have to be stripped (“no” branch of decision step 420 ), the data packet is processed as received (step 430 ).
Processing the data packet includes routing the data packet using a multi-layer switch. Processing the packet also includes allocating bandwidth, specifying a minimum bandwidth, and specifying a maximum bandwidth for the data packet. Processing the packet can also include redirecting the packet to another port of the network device 215 processing the data packet, redirecting the data packet to another device connected to the network 220 , mirroring the packet to a particular physical port of the network device 215 , prioritizing the data packet, and counting discarded data packets. The network device 215 receiving the data packet can also modify the network rights descriptor for the data packet, or add a secondary network rights descriptor to the data packet. The secondary or modified network rights descriptor is used in the same manner as the original network rights descriptor. In one implementation, the network device 215 is a multi-layer switch that processes the data packet according to user-defined packet policies for the network rights descriptor contained in the data packet.
Data packets can be marked with network rights descriptors based on additional parameters such as source IP address, destination IP address, MAC address, time of day, traffic content, traffic type (e.g., voice, video, documents, graphics, file types), VLAN tag, device ID, encrypted key, and application source. These network rights descriptors can be processed in a manner similar to application rights descriptors in FIG. 4 to implement user-defined policies based on the additional parameters.
The invention can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. The invention can be implemented as a computer program product, i.e., a computer program tangibly embodied in an information carrier, e.g., in a machine-readable storage device or in a propagated signal, for execution by, or to control the operation of, data processing apparatus, e.g., a programmable processor, a computer, or multiple computers. A computer program can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network.
Method steps of the invention can be performed by one or more programmable processors executing a computer program to perform functions of the invention by operating on input data and generating output. Method steps can also be performed by, and apparatus of the invention can be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit).
Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in special purpose logic circuitry.
The invention can be implemented in a computing system that includes a back-end component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a front-end component, e.g., a client computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the invention, or any combination of such back-end, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (“LAN”) and a wide area network (“WAN”), e.g., the Internet.
The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network.
The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.
The invention has been described in terms of particular embodiments. Other embodiments are within the scope of the following claims. For example, the steps of the invention can be performed in a different order and still achieve desirable results. | Methods and apparatus, including computer program products, implement techniques of processing data packets in a computer network. The computer network includes a multiport network device and a computer executing a software application. The multiport network device is configured to receive data packets to be transmitted using the computer network and the network device stores one or more authorized network descriptors. The software application generates data packets to be transmitted to the computer network through the network device. The software application registers the network rights descriptor with the network device and inserts the network rights descriptor in each generated data packet. The network device is configured to discard the data packet if the network rights descriptor in the data packet does not match an authorized network rights descriptor and to process the data packet if the network rights descriptor in the data packet matches an authorized network rights descriptor. | 7 |
BACKGROUND OF THE INVENTION
The weft feeding devices for weaving looms or for textile machines in general (also briefly called weft feeders), now used on all modern shuttleless looms, are usually of the type with a drum for weft yarn storage, incorporating a coaxial electric motor. The weft yarn, unwound from a reel or bobbin, is wound in turns by a rotor on the drum, so as to form a reserve thereon, from which the loom subsequently draws the weft yarn with a tension being as uniform and as regular as possible.
The overall structure most commonly adopted by constructors for these devices comprises a casing formed of a central body housing the electric motor and of a peripheral arm rigidly connected to the central body and supporting a weft yarn brake unit, a sensor detecting the amount of yarn wound on the drum, and a yarnguide eyelet.
The central body of the device is required to have a proper rigidity and high thermal dissipation properties, while the peripheral arm, as well as being suitably stiff, should also act as a sliding and support guide for the brake unit, for the sensor detecting the yarn reserve and for the yarnguide, these members having to be easily movable longitudinally along the arm, so as to control the strength of the braking action on the yarn being fed from the device and, respectively, the yarn reserve being stored on the drum.
The main longitudinal axis of the device corresponds to the motor and drum axes, while the longitudinal axis of the sliding guide should be parallel to the main axis, so as to always allow proper alignment of the brake unit and of the detector in respect of the remaining part of the device.
To satisfy these requirements, in the casings of known weft feeders, the central body is conventionally obtained by casting of aluminum or "zamak" (or other alloy) and, for large production quantities, diecasting is obviously adopted, involving considerable investments for the casting equipment.
As concerns the peripheral support and guiding arm, it should be rigidly fixed to the central body and can be made from different materials and using different methods, for instance by casting of aluminium, zamak or other alloys (adopting diecasting for large quantities of pieces), with the sliding guides incorporated into the arm and eventually obtained by subsequent machining, or made of stamped iron plate or extruded bar and performing simultaneously the dual function of support and guide, or made of section iron or of a similar material with the sliding guides obtained by machining, or finally also obtained by simultaneously adopting two or more of these systems, like associating a secion iron as support with an aluminium extrusion as sliding guide.
In any case, all these systems require a proper fixing between the various parts forming the casing, as well as supplementary machinings which are often neither simple nor economical.
Furthermore, to give a pleasant aspect to the weft feeder, one usually provides for surface finishings, like varnishing and/or applying closing and finishing elements, generally of plastic material, these steps involving costs and structural complications which should well be taken into consideration.
SUMMARY OF THE INVENTION
The present invention now proposes to supply a casing for weft storage and feeding devices which is much simpler and more economical to produce than the conventional ones and which requires no finishing steps to improve its appearance, thereby providing further advantages from the economical point of view.
The casing for weft storage and feeding devices according to the invention is substantially characterized in that it is formed from at least one extruded section length.
Said extruded section length will have to be suitably machined, removing parts thereof by simple cutting, while other simple and inexpensive machinings may be performed thereon for adjustment purposes.
The casing will preferably be formed from two extruded section lengths, firmly connected one to the other.
Extruded sections of aluminium or aluminium alloys are the most suited to construct the casing of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is now described in further detail, with reference to a preferred embodiment thereof, wherein the casing for weft storage and feeding device is formed from two extruded section lengths. This embodiment is illustrated in the accompanying drawings, in which:
FIG. 1 is a cross section view of the two extruded section lengths, associated to form the casing according to the invention;
FIGS. 2 and 3 are a side view and a top view of the two lengths of FIG. 1, associated to form the casing according to the invention;
FIG. 4 is a comprehensive view of a weft feeder constructed with the casing of FIGS. 1 to 3;
FIGS. 5 to 10 are suitably enlarged section views, corresponding to the zones C, D, of FIG. 1, showing methods of associating the section lengths of FIG. 1 in order to obtain the casing according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawings, the present invention proposes to use, for the construction of a weft feeder casing, a pair of section lengths obtained by extrusion, preferably of aluminium or aluminium alloys, associated one to the other by known methods.
As shown in FIGS. 1 to 3, the casing is obtained from an extruded length 1, forming the central body with axis A--A, which houses the weft feeder motor in its cylindrical cavity 1A, and from an extruded length 2, with axis B--B, forming the peripheral support and guiding arm. The length 1 already comprises fins 1B, adapted to efficiently dissipate the heat from the motor and to facilitate mounting and position adjustment of the weft feeder on the loom or other textile machine onto which it is applied. In the length 2, the inner projections 2A form the sliding guide for the sensor detecting the yarn reserve, while the cavity 2B is adapted to house--along the length 1 and of the motor contained therein--the cards of the electronic circuits controlling the weft feeder.
The extruded lengths 1 and 2 are obtained by simply cutting them into the size exactly required for the purposes having to be fulfilled, from considerably long extruded sections easily obtainable on the market. The length 1, forming the central body, is therefore considerably shorter than the length 2, which forms the arm.
It should be noted that this arrangement is possible thanks to the fact that the cross section of the casing has been divided, as shown in FIG. 1, along the zones C and D.
On the other hand, along such zones, it is necessary to provide for the tight connection between the two lengths, in order to give to the casing of the invention the required monolithic structure. This may be obtained in any known manner, for instance by simply fixing together the extruded lengths, suitably shaped for the purpose--as shown in FIG. 5, where the engagement is favoured by the elasticity of the section length 2; or in FIG. 6, where a conventional dovetail engagement is obtained; or in FIGS. 7 and 8, where a free sliding engagement is obtained between the two lengths 1 and 2, fixing them together by pressure insertion of a frustoconical pin 3 into flange elements 4 and 5 thereof, provided with suitable seats--or by connecting the lengths 1 and 2 with a welding seam 6--as shown in FIG. 9--or even by simply fixing together the two lengths by means of screws, bolts or transverse rivets 7--as shown in FIG. 10. In any case, the choice of the type of connection depends on the geometry of the profile and on the experience of the firm producing the extruded sections. The important thing is to actually obtain a monolithic structure of the casing.
The solution according to the invention allows to construct the casing of a weft feeder making use of the extrusion technique, by means of which it is possible to obtain bars of considerable length, with the desired profile, and having fairly close tolerances so as to often avoid machining.
In fact, as seen, the profile of the section of the casing is determined by the profile of the die used for the extrusion of the section lengths, the cost of which is fairly contained compared to that of pressure casting dies, and which allows to extrude aluminium and its alloys.
On the other hand, these lengths are obtained--as also seen--by an elementary cutting of bar sections which can easily be found on the market, and they require practically no finishing operations. In fact, the structure formed therewith can be left unchanged in the finished device, as it has a pleasant appearance. Alternatively, since the structure is usually made of aluminium, a surface finishing can be provided by simple anodizing (to be executed also on the full bar and being in any event of limited cost).
FIG. 4 shows diagrammatically a complete weft feeder constructed with the casing according to the invention. In it can be seen: the main axis A--A and the axis B--B of the sliding guide; the casing according to the invention, comprising the central body formed from the length 1 and the peripheral arm formed from the length 2, tightly connected one to the other in the zone CD to form a monolithic structure; flanges 8 for closing the central body and supporting the motor shaft; a drum 9 around which the yarn reserve is wound; the sensor 10 for detecting the yarn reserve; the brake unit 11; and the outlet eyelet 12.
It can be noted that, through a fully original and highly advantageous construction of the casing or carrying structure of the device, it has been possible to obtain a conventional weft feeder configuration.
Since the operations involving cutting the bar sections, to obtain the lengths 1 and 2, and then removing the excess parts of such lengths--see dashed lines of FIGS. 2 and 3 for the length 2--are very simple and thus economical, and since, moreover, the initial investment for the extrusion die is modest and it is possible to avoid any extra body parts, while the surface finishing treatment is not required, or is in any event simple and economical, the solution proposed by the invention is particularly important from the economic point of view. This is all the more true when considering, furthermore, that the removed parts of the section lengths can be easily recycled, the energy consumption for aluminium and its alloys being advantageously low.
Moreover, the monolithic body generally requires very little machining, on account of the dimensional precision of the extruded piece and, if the section design has been carefully planned, the machining can even be avoided or reduced to merely boring the housing for the motor.
It is understood that the invention covers any other embodiments thereof apt to satisfy the same requirements. In particular, it covers a casing obtained from a single length of extruded bar, the cross section of which substantially corresponds to the assembly of FIG. 1 (imagining the separation lines C and D between parts 1 and 2 not to be there, said parts forming in this case a single body), and the cutting of which takes place in two stages, so as to obtain first of all a length of the size of the casing arm, and subsequently remove therefrom the surplus portion to the side of said arm to obtain the shorter central body, up to forming a casing substantially like that shown in FIGS. 1 to 3 (wherein, in addition to lines C and D, also the separation line Z between lengths 1 and 2 in FIG. 2 should be eliminated), but--unlike that--obtained in one piece.
A construction of this type obviously provides the advantages of a totally monolithic structure of the casing and of a faster and simpler production thereof in finished form, but it involves further waste of material (even if its recovery is particularly easy and convenient); moreover, there can be practical difficulties of construction since use has to be made of extruders having a power and dimensions which are not easy to find on the market. | A casing for weft storage and feeding devices for use in weaving looms comprises a central body housing the motor; and a peripheral arm guiding and supporting the brake unit, the sensor detecting the yarn reserve, and the yarn-guide eyelet. The casing is formed from at least one extruded section length. | 3 |
FIELD OF INVENTION
[0001] The presently described invention relates generally to a flexible and collapsible straightedge and leveling device to be used in any application requiring a level or straightedge such as installing wallpaper, hanging pictures, posters, or other articles upon walls. More specifically it relates to the combination of the flexible straightedge with a level, which is a combined tool that is durable, not bulky, and is compact yet sturdy to fulfill the full functionality of a level and a straightedge.
BACKGROUND
[0002] Levels have been part of the construction industry since the ancient times. The reed level was used by the ancient Arabs during construction of structures. Leveling devices are used to achieve a level position when hanging pictures, posters or other articles upon walls.
[0003] One type of leveling device is a bubble-within-fluid leveling device. This is generally termed a “spirit” level (or “bubble” level). The spirit level was invented by Melchisedech Thevenot in the 1600's. Typically, spirit levels comprise a transparent tubular vial that contains a predetermined quantity of fluid (such as a spirit or alcohol), leaving a bubble in the vial. Leveling devices generally comprise a body made of aluminum or metal that have various apertures and have tubular vials positioned within those apertures so that the leveling bubble in the tubular vial can be seen from the front or back of the leveling device.
[0004] Leveling devices are typically designed to indicate whether a surface is horizontal (level) or vertical (plumb). A spirit level is used to achieve a level position by aligning a straight edge of the level with an edge of the article, and adjusting the article's angle until the bubble is centered within the surrounding liquid. Different types of spirit levels may be used by carpenters, plumbers, electricians, handymen, stonemasons, bricklayers, other building trades workers, surveyors, millwrights and other metalworkers, and in some photographic or videographic work. Most leveling devices used in the construction industry are relatively large and expensive, are made of aluminum or metal, and are generally bulky.
[0005] More recently, leveling devices have incorporated use of a laser. These include manual-leveling lasers, self-leveling and automatic-leveling lasers, horizontal lasers, dual beam (or split-beam) lasers, line laser and rotary laser levels. These leveling devices are generally more expensive than traditional bubble-type lasers, and are bulkier and require charging or use of a battery.
[0006] A straightedge is a tool with an edge free from curves, or which is straight. It is used for transcribing straight lines, or checking the straightness of lines or edges. Some are combined with measurement indicia (or markings) to function as rulers or as measuring devices. Straightedges are generally used in the automotive service and machining industry to check the flatness of machined mating surfaces. They are also used as guides for installing wallpapers. True straightness can in some cases be checked by using a laser line level as an optical straightedge whereby it illuminates a straight line on a flat surface such as the edge of a plank or shelf. Straightedges which incorporate lasers are expensive. Moreover, to date, straightedges have been constructed of rigid (non-flexible) surfaces between one and four feet long and can be bulky and very heavy.
[0007] Collapsible or rollable tape measures have been used by seamstresses and other clothing designers to accurately measure the human form. However, the construction industry and consumers have not adapted the rollable tape measure for use as a straightedge as it is not able to maintain a straight edge without significant assistance. Moreover, collapsible or rollable tape measures simply do not provide the combined functionality of a leveling device.
[0008] Thus, a need exists for a device that combines the functionality of a straightedge and a level, including a straightedge with measurement indicia that allows it to also function as a ruler. There is a need for a compact, sturdy, lightweight, easy and inexpensive to manufacture, reusable and durable device that provides a combined functionality of a straightedge and a level, with the added functionality of a ruler.
SUMMARY
[0009] The presently described invention relates generally to the combination of a collapsible straightedge, level, and ruler.
[0010] It is an object of the present invention to provide a single device that is capable of independently functioning as a straightedge, a level and/or a ruler.
[0011] It is also an object of the present invention to provide a device that has the combined features of a straightedge and level that is lightweight, compact, sturdy, easy and inexpensive to manufacture, reusable, and durable in its construction.
[0012] Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims, and when read in conjunction with the accompanying drawings.
[0013] The combination straightedge, ruler and level (“CSRL”) is developed for use in the installing of wallpaper, pictures and other home decor, but can be used in any application requiring a level, ruler or straightedge. While it is reusable, because of its low cost of manufacture, it may also be disposable. The CSRL can be used both in the vertical and horizontal position. The CSRL can also be rolled into a coil, which reduces storage space.
[0014] In an exemplary embodiment of the present invention, the straightedge is made of polystyrene, styrene, plastic or other materials known in the art which allow for the straightedge to retain its shape when rolled or folded. The straightedge is able to retain its rigidity when unfolded such that it does not need external assistance to operate as a straightedge (such as a hand to hold in place). The straightedge may include markings (or measurement indicia) on the top and bottom in equal increments which operate as a measuring device or ruler. The measurement indicia may also be on a front side and/or a back side of the straightedge. These markings or indicia can be either metric, US or other systems of measurement.
[0015] In this exemplary embodiment, the length of the CSRL can be three to four feet in length with a width of two and a half inches. The CSRL is of an operative thickness, but preferably 0.020 inches. The thickness of the CSRL can be varied depending upon the type of material used, so that it is rigid enough to function as a straightedge, yet foldable or rollable and able to retain its shape when rolled or folded. The length and width of the CSRL can also be varied.
[0016] The level portion of the CSRL is preferably of a bubble level variety. The leveling unit may be attached to the straight edge such as through adhesive or plastic riveting. The leveling unit is made of plastic or other lightweight material. The leveling unit is attached at one end of the CSRL, approximately one inch from the end, though it may be attached anywhere on the straightedge. The leveling unit itself preferably contains both “plumb” (90 degrees in the vertical direction) and “straight” (90 degrees in the horizontal direction) levels. The leveling unit that is used in an exemplary embodiment is approximately two inches in height and two and one quarter inches in length.
[0017] The CSRL is rollable and can be tucked into a relatively space for storage. In order to keep the CSRL rolled when not in use, it has an optional hook and loop (such as “Velcro®” strips). The CSRL can also be kept in its folded or rolled configuration using a string, or through fasteners such as but not limited to, clips and snap buttons.
[0018] In an another exemplary embodiment, each end of the CSRL has a punched hole (approximately one-eighth inch in diameter) located at a position that is horizontally aligned with the center of the leveling unit.
[0019] Additional features and embodiments of the systems will be described hereinafter and will form the inventive subject matter supporting the claims appended hereto. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the systems are not limited in application to the details of construction or to the arrangements of the components set forth in the following description or illustrated in the drawings. Rather, the systems may be practiced in numerous forms and embodiments, and of being practiced and carried out in various ways, all within the scope of the present inventions. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting.
[0020] These and other embodiments, features, aspects, and advantages of the inventive systems will become better understood with regard to the following description, appended claims and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The foregoing aspects and the attendant advantages of the present invention will become more readily appreciated by reference to the following detailed description, and when taken in conjunction with the accompanying drawings, wherein:
[0022] FIG. 1 is front plan view of portions of the CSRL according to one embodiment of the present invention, with a break about the middle represented by a zig-zag line.
[0023] FIG. 2 is a perspective view of the CSRL as it appears when in its rolled or folded configuration.
[0024] FIG. 3 is a front plan view of the CSRL as it appears when used in the vertical position.
[0025] FIG. 4 is a front plan view of the CSRL as it appears when used in the horizontal position.
[0026] FIG. 5 is a top view of the CSRL as it appears when held in place in its rolled or folded configuration.
[0027] FIG. 6 is a front plan view of an embodiment of the CSRL with the measurement indicia on a top portion of the CSRL.
[0028] FIG. 7 is a front plan view of an embodiment of the CSRL with the measurement indicia on both the top portion and bottom portion of the CSRL.
DETAILED DESCRIPTION
[0029] The presently described invention relates generally to the combination of a collapsible straightedge, level, and ruler.
[0030] The CSRL is developed for use in the installing of wallpaper, pictures and other home decor, but can be used in any home application requiring a level, ruler or straightedge. The low cost provides near throwaway functionality. The CSRL can be used both in the vertical and horizontal position. The CSRL can also be rolled into a coil, which reduces the space required to store a device which has the combined features of a straightedge, level and ruler.
[0031] FIG. 1 is front plan view of an exemplary embodiment of the CSRL ( 100 ) showing the placement of the leveling unit ( 130 ), with a break about the middle represented by a zig-zag line. The portion represented by this zig-zag line is a uniform portion of a straightedge ( 115 ).
[0032] The CSRL depicted in FIG. 1 comprises a straightedge ( 115 ) and a leveling unit ( 130 ). In an exemplary embodiment, the CSRL may be three to four feet in length with a width of two and a half inches. The length and width of the CSRL can be varied. The CSRL is of a predetermined, operative thickness to allow flexibility (and capability to be rolled) yet rigidity such that the CSRL is independently capable of operating as a straightedge. For example, a thickness of 0.020 inches of a styrene material, allows such capability.
[0033] Referring to FIG. 1 , the leveling unit ( 130 ) of the CSRL may comprise a combination of a vertical level ( 140 ), a horizontal level ( 150 ). The leveling unit ( 130 ) is preferably of a bubble level variety. The leveling unit ( 130 ) is preferably made of plastic or other lightweight material. The leveling unit ( 130 ) may be attached to the surface of the straightedge through either an adhesive (such as but not limited to thermal set adhesive) or through rivets ( 160 ) (such as but not limited to brass or plastic rivets), to secure the leveling unit ( 130 ) to the CSRL ( 100 ). The leveling unit ( 130 ) is attached to the surface of the straightedge, to allow vertical and/or horizontal leveling. In an exemplary embodiment such as shown in FIG. 1 , the vertical level ( 140 ) is aligned with, or parallel to, the left vertical edge ( 115 c ) and the right vertical edge ( 115 d ) of the straightedge ( 115 ). The horizontal level ( 150 ) is aligned with, or parallel to, the top horizontal edge ( 115 f ) and the bottom horizontal edge ( 115 g ) of the straightedge ( 115 ).
[0034] The leveling unit ( 130 ) preferably contains both “plumb” (90 degrees in the vertical direction) and “straight” (90 degrees in the horizontal direction) levels. The leveling unit incorporated into the straightedge may be sourced from manufacturers such as Guangzhou Youcheng Hardware Co., Ltd., of Xingang Zhonglu, Guangzhou, China.
[0035] The straightedge ( 115 ) is made of styrene, polystyrene, plastic or other materials known in the art which allow for the straightedge to retain its shape when rolled or folded. The straightedge is able to retain its rigidity when unfolded as shown in FIG. 1 such that it does not need external assistance to operate as a straightedge.
[0036] As shown in FIG. 1 , the straightedge ( 115 ) also has measuring indicia or units ( 110 ) printed on the straightedge's surface. The straightedge ( 115 ) has a top portion ( 115 a ) and a bottom portion ( 115 b ), and the straightedge ( 115 ) may include the markings (or measurement indicia) on the top portion ( 115 a ) and/or the bottom portion ( 115 b ) in equal increments which operate as a measuring device or ruler. The measurement indicia or units ( 110 ) may also be on a front side and/or a back side of the straightedge ( 115 ). The straightedge ( 115 ) may be opaque, translucent, or transparent. These markings or indicia can be either metric, US or other systems of measurement.
[0037] The straightedge ( 115 ) also has punched holes ( 120 a and 120 b ). As shown in FIGS. 3 and 4 , and as discussed below, pins ( 125 a and 125 b ) may be placed into these punched holes ( 120 a and 120 b ) to secure the CSRL ( 100 ) in place while in operation. Commercially-available pins or thumb tacks may be used. In an exemplary embodiment depicted in FIG. 1 , the straightedge ( 115 ) has a first punched hole ( 120 a ) and a second punched hole ( 120 b ), each approximately one eighth inch in diameter. The first punched hole ( 120 a ) may be located proximal to the left vertical edge ( 115 c ) and the second punched hole ( 120 b ) may be located proximal to the right vertical edge ( 115 d ) of the straightedge. In an embodiment wherein the straightedge ( 115 ) is approximately two and a half inches in width, each punched hole is centered at approximately one and one fourth inches from the straightedge's top horizontal edge ( 115 f ) and one and one forth inches from the straightedge's bottom horizontal edge ( 115 g ). Preferably, as shown in FIG. 1 , each punched hole ( 120 a and 120 b ) is located at a position that is horizontally aligned with the center of the leveling unit ( 130 ).
[0038] FIG. 2 is a perspective view of the CSRL ( 100 ) as it appears when in its rolled or folded configuration. Preferably, the leveling unit ( 130 ) is located on the inside of the roll to protect the leveling unit.
[0039] FIG. 3 is a view of the CSRL ( 100 ) as it appears when used in the vertical position with the leveling unit ( 130 ) and punched holes ( 120 a and 120 b ) in use when securing the CSRL ( 100 ) to a surface.
[0040] As shown in FIG. 3 , the CSRL ( 100 ) is placed in a vertical position, for example, at the point where a first piece of wallpaper would be applied. A first pin ( 125 a ) is then inserted into a first punched hole ( 120 a ). After the first pin ( 125 a ) is inserted, the straightedge ( 115 ) is then adjusted to the left or to the right. Once the bubble ( 140 a ) in the plumb or vertical level ( 140 ) of the leveling unit ( 130 ) is centered, a second pin ( 125 b ) is then inserted into a second punched hole ( 120 b ). A pencil or other marker may then be used to draw a vertical line from top to bottom, or vice versa, using the straightedge ( 115 ) as a guide.
[0041] FIG. 4 is a front plan view of the CSRL ( 100 ) as it appears when used in the horizontal position with the leveling unit ( 130 ) and punched holes ( 120 a and 120 b ) in use when securing the CSRL ( 100 ) to a surface.
[0042] As shown in FIG. 4 , the CSRL ( 100 ) is placed in a horizontal position. A first pin ( 125 a ) is then inserted into a first punched hole ( 120 a ). After the first pin ( 125 a ) is inserted, the straightedge ( 115 ) is then adjusted upwards or downwards. Once the bubble ( 150 a ) in the horizontal level ( 150 ) of the leveling unit ( 130 ) is centered, a second pin ( 125 b ) is then inserted into a second punched hole ( 120 b ). A pencil or other marker may then be used to draw a horizontal line from left to right, or vice versa, using the straightedge ( 115 ) as a guide.
[0043] FIG. 5 is a top view of the CSRL ( 100 ) as it appears when held in place in its rolled or folded configuration when not in use, with the leveling unit ( 130 ) preferably on the inside of the roll. The CSRL is rollable and can be tucked into a relatively space for storage. In order to keep the CSRL rolled when not in use, it has an optional hook and loop, such as but not limited to, “Velcro®” attachments ( 500 ) shown in FIG. 5 . A piece of fabric with “Velcro®” strips that is looped around the rolled CSRL, or Velcro® strips attached to the surface of the straightedge may also be used to keep the CSRL in its rolled configuration. The CSRL ( 100 ) can also be removably kept in its folded or rolled configuration with a string or using various fastening means such as but not limited to, snap buttons or clips, or by any other means known in the art to prevent the CSRL ( 100 ) from unfolding as shown in FIG. 1 .
[0044] FIG. 6 is a front plan view of another embodiment of the CSRL with the measurement indicia on the top portion of the CSRL.
[0045] FIG. 7 is a front plan view of another embodiment of the CSRL with the measurement indicia on both the top portion and bottom portion of the CSRL.
[0046] Although specific embodiments of the CSRL have been described, various modifications, alterations, alternative constructions, and equivalents are also encompassed within the scope of these inventions.
[0047] The specification and figures are, accordingly, to be regarded in an illustrative rather than a restrictive sense. It will, however, be evident that additions, subtractions, deletions, and other modifications and changes may be made thereunto without departing from the broader spirit and scope of the inventions as set forth in the claims. | A combination straightedge, ruler and leveling tool which contains both horizontal and vertical levels for use in various applications in home decorating and in the construction industry, wherein the combination straightedge, ruler and leveling unit is made of a rigid, but flexible material that can be rolled into a coil for a smaller storage footprint, and that can be unrolled for later use. The combination tool also has an optional hook and loop (such as “Velcro®” strips), or optional fasteners, snap buttons, or a string to keep it in a rolled configuration. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The entirety of each of International Application No. PCT/CN2011/071154, filed Feb. 22, 2011 and Chinese Patent Application No. 201020674383.8, filed Dec. 21, 2010, are hereby incorporated by reference.
BACKGROUND
1. Field of the Invention
This application is directed to products for providing shade from the sun or protection from the wind, rain, snow, or other elements, particularly as related to umbrellas. In some embodiments, a free arm umbrella (e.g., cantilever, wall-mounted, etc.) is provided, mainly used for hanging or securing on a wall.
2. Description of the Related Art
Generally, sun-shading products currently on the market are commonly known for being complicated in structure, high in price, and occupying a relatively large amount of space. With living spaces decreasing in size in buildings, homes and apartments in cities and other environments, there is a demand for products that allow people living in such environments to enjoy outdoor leisure in the shade in small places (e.g., a balcony). This application is directed to improved free arm umbrella structures, featuring favorable price, structure, and compactness at least when stowed.
SUMMARY
Overcoming disadvantages mentioned above, this application is directed to an effort to provide a free arm umbrella for large-scale application, which features simple structure, easy operation, low or affordable price and usability in a narrow, small, or limited space.
To meet the ends or objectives described above, in some embodiments, the following technical solutions are adopted for these free arm umbrellas:
In some embodiments, the free arm umbrella includes a fixing plate, an upper hub (e.g., nest), a lower hub (e.g., nest), umbrella ribs and support ribs. The umbrella ribs are hingedly coupled with the upper nest and the first and second ends of each of the support ribs are hingedly coupled with the lower nest and one of the umbrella ribs respectively. In some embodiments, the free arm umbrella also includes a control mechanism, a support rod, a first strut rod and a second strut rod. The first and second ends of the first strut rod are hingedly coupled with the lower nest and the upper portion of the fixing plate respectively. One end of the second strut rod is hingedly coupled with the upper nest and the other end is provided with a support block. A middle part of the first strut rod or portion positioned between the first and second ends is hingedly coupled with the middle part of the second strut rod or portion positioned between the two ends of the second strut rod. The first and second ends of the control mechanism support rod are hingedly coupled with the second strut rod and the fixing plate respectively. The control mechanism is fixed on the fixing plate. The support block is moveably fixed on the control mechanism.
In some embodiments, the free arm umbrella also includes a rotating lockout mechanism. The fixing plate includes a first fixing plate and a second fixing plate. The rotating lockout mechanism is set or positioned between the first fixing plate and the second fixing plate, and respectively fixed onto the two plates. The support rod, control mechanism and first strut rod are all hingedly coupled with the second fixing plate.
In some embodiments, an upper part of the first fixing plate can be flexibly connected to an upper part of the second fixing plate.
In some embodiments, the rotating lockout mechanism comprises a knob handle, fastening screw, first latch segment and second latch segment. The first latch segment engages with the second latch segment. The fastening screw runs through the first and second latch segments, and engages with the knob handle. The first latch segment is fixed on the second fixing plate, while the second latch segment on the first fixing plate, the support rod hinged with the second fixing plate, and the control mechanism on the second fixing plate.
In some embodiments, the free arm umbrella is also equipped with a first L-shape flat bar and a second L-shape flat bar. The first L-shape flat bar and second L-shape flat bar are fixed respectively with the second fixing plate and the first fixing plate, and at the same time are held, secured and/or supported respectively by the first latch segment and second latch segment.
Furthermore, in some embodiments, the fastening screw has an oval head and square neck. It runs or extends through the first L-shape flat bar, the first latch segment, the second latch segment and the second L-shape flat bar, and then engages with threads on the knob handle. The neck of the screw is stuck, positioned and/or fixed in the first L-shape flat bar.
In some embodiments, the control mechanism comprises a housing, spring plate, and spanner. The lower part of the spring plate is fixed on the housing. The spanner can be moveably set inside the housing. The lower part of the spanner lies against the spring plate. The housing is fixed on the fixing plate and has a slideway. The supportblock runs or extends through the slideway and is held, supported, and/or secured by the spring plate.
In some embodiments, the control mechanism also includes elastic components. The elastic components are set or positioned between the spring plate and the housing, and connected or coupled to the spring plate and the housing respectively.
In some embodiments, the free arm umbrella also comprises a control handle, which is set or positioned on the second strut rod, near, adjacent, or in close proximity to the support block.
In some embodiments, the free arm umbrella includes three umbrella ribs and three support ribs.
The benefits of this these embodiments include but are not limited to: this free arm umbrella applies a scissor-type opening method, and is fixable on a wall or can be hung on a column with the fixing plate. In some embodiments, the rotating lockout mechanism enables the umbrella to swing or rotate, and the control mechanism facilitates the opening of the umbrella. With simple structure, easy operation, low cost and usability in a narrow space, this umbrella is suitable for large scale applications in some embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects and advantages are described below with reference to the drawings, which are intended to illustrate but not to limit the inventions. In the drawings, like reference characters denote corresponding features consistently throughout similar embodiments.
FIG. 1 is a front schematic view of an example of a free arm umbrella in a closed position.
FIG. 2 is a perspective view of the example free arm umbrella as shown in FIG. 1 in an open position.
FIG. 3 is a side view of the example free arm umbrella as shown in FIG. 1 in an open position.
FIG. 4 is an enlarged view of the details of Area A of the example free arm umbrella as shown in FIG. 3 .
FIG. 5 is an exploded view of certain components of the example free arm umbrella as shown in FIG. 4 .
FIG. 6 is an exploded view diagram of an example fixing plate and rotating lockout mechanism of the free arm umbrella as shown in FIG. 2 .
FIG. 7 is perspective view of another example free arm umbrella.
FIG. 8 is a detail view of the example free arm umbrella as shown in FIG. 7 .
FIG. 9 is a partial view of the example free arm umbrella as shown in FIG. 8 with a handle removed.
FIG. 10 is a top perspective view of the handle shown in FIG. 8 and removed in FIG. 9 .
FIG. 11 is a partial view of the example free arm umbrella as shown in FIG. 8 with a pivotable member removed.
FIG. 12 is a partial view of the example free arm umbrella as shown in FIG. 8 with a housing removed.
FIG. 13 is rear perspective view of the pivotable member as shown in FIG. 8 and removed in FIG. 11 .
DETAILED DESCRIPTION
While the present description sets forth specific details of various embodiments, it will be appreciated that the description is illustrative only and should not be construed in any way as limiting. Furthermore, various applications of such embodiments and modifications thereto, which may occur to those who are skilled in the art, are also encompassed by the general concepts described herein.
To articulate the technical characteristics of this application, examples of the free arm umbrella and various components herein are detailed below as an illustration of potential embodiments.
See FIGS. 1-6 for details of various embodiments. In some embodiments, the free arm umbrella includes a fixing plate 1 , which is a type of wall mount structure that enables rotation of the free arm umbrella, upper hub (e.g., nest) 2 , lower hub (e.g., nest) 3 , umbrella ribs 5 and support ribs 6 . The umbrella ribs 5 and support ribs 6 are a type of umbrella structural members. A shade providing structure can include the upper hub (e.g., nest) 2 , lower hub (e.g., nest) 3 , umbrella ribs 5 and support ribs 6 . The umbrella ribs 5 are hingedly coupled with upper nest 2 . The first and second ends of each of the support ribs 6 are hingedly coupled with lower nest 3 and umbrella ribs 5 respectively. The free arm umbrella includes a control mechanism 7 , support rod 9 , first strut rod 10 and second strut rod 20 . The first and second ends of the first strut rod 10 are hingedly coupled with the lower nest 3 and fixing plate 1 respectively. One end of the second strut rod 20 is hingedly coupled with the upper nest 2 , and the other end is provided with a support block 21 . A middle part of the first strut rod 10 or middle portion disposed between the two ends of first strut rod 10 is hingedly coupled with a middle part of the second strut rod 20 or middle portion disposed between the two ends of the second strut rod 20 . The first and second ends of the support rod 9 are hingedly coupled with the second strut rod 20 and the fixing plate 1 respectively. The control mechanism 7 is fixed on or coupled to the fixing plate 1 . The support block 21 is moveably fixed on the control mechanism 7 .
In some embodiments, the free arm umbrella also includes a rotating lockout mechanism 8 , which is a type of umbrella positioning or rotation device. The fixing plate 1 includes a first fixing plate 11 and a second fixing plate 12 . The rotating lockout mechanism 8 is set, positioned, supported and/or secured between the first fixing plate 11 and the second fixing plate 12 , and respectively fixed onto or coupled to the two fixing plates. The support rod 9 is hingedly coupled with the second fixing plate 12 , the control mechanism 7 is fixed on the second fixing plate 12 , and first strut rod 10 is also hingedly coupled with the second fixing plate 12 . In some embodiments, the upper part of the fixing plate 11 and the upper part of the fixing plate 12 are moveably or rotatably hinged together. See FIG. 6 for details. In some embodiments, the fixing plate 1 includes a first L-shape flat bar 13 and a second L-shape flat bar 14 . The first L-shape flat bar 13 and the second L-shape flat bar 14 are respectively fixed to the first fixing plate 11 and the second fixing plate 12 . The first L-shape flat bar 13 and the second L-shape flat bar 14 partially overlap each other and are connected by a screw 15 , thus allowing for rotation between the first fixing plate 11 and the second fixing plate 12 in some embodiments if needed.
In some embodiments, the rotating lockout mechanism 8 includes a knob handle 81 , fastening or carriage screw 82 , first latch segment 83 , and second latch segment 84 . The first latch segment 83 engages with the second latch segment 84 . The fastening screw 82 runs or extends through the first and second latch segments 83 and 84 , and engages with the threads on the knob handle 81 . The first latch segment 83 is fixed on or coupled to the second fixing plate 12 , while the second latch segment 84 is fixed on or coupled to the first fixing plate 11 . The support rod 9 is hingedly coupled with the second fixing plate 12 and the control mechanism 7 is fixed on or coupled to the second fixing plate 12 . Preferably, the free arm umbrella is also equipped with a first L-shape flat bar 85 and a second L-shape flat bar 86 . The first L-shape flat bar 85 and second L-shape flat bar 86 are fixed or coupled respectively with the second fixing plate 12 and the first fixing plate 11 , and at the same time are held, secured, or supported respectively by the first latch segment 83 and second latch segment 84 . See FIG. 6 for reference. In some embodiments, the fastening screw 82 has an oval head and square neck. It runs or extends through the first L-shape flat bar 85 , the first latch segment 83 , the second latch segment 84 and the second L-shape flat bar 86 , and engages with the threads of the knob handle 81 . The neck of the screw is received by or inserted in an opening of the first L-shape flat bar 85 . The two L-shape flat bars 85 and 86 are fixed or positioned between the second fixing plate 12 and first fixing plate 11 respectively, thus enabling the first latch segment 83 and second latch segment 84 to loosen and engage through the round headed square necked screw 82 , and allowing for the rotation between the second fixing plate 12 and first fixing plate 11 through the two L-shape flat bars 85 and 86 .
In some embodiments, the control mechanism 7 comprises a housing 71 , spring plate 72 , and a spanner 73 . The lower part of the spring plate 72 is fixed on the housing 71 . The spanner 73 can be moveably set inside the housing 71 . The lower part of the spanner 73 is positioned or lies against the spring plate 72 . The housing 71 is fixed on the fixing plate 1 with a slideway 74 . The support block 21 runs through the slideway 74 and is received by or secured by the spring plate 72 . In some embodiments, the control mechanism 7 also includes one or more elastic components or biasing mechanisms 75 . The elastic components 75 are set or positioned between the spring plate 72 and the housing 71 , and respectively connected to the spring plate 72 and housing 71 . See FIGS. 4 and 5 for reference. In some embodiments, the elastic components 75 refer to springs. The housing 71 is fixed on or secured to the second fixing plate 12 .
See FIG. 3-5 for details to facilitate operation by a user according to some embodiments. In some embodiments, the free arm umbrella also comprises a control handle 22 , which is set, coupled to or positioned on the second strut rod 20 , near, adjacent, or in close proximity to the support block 21 .
Theoretically, there can be any number of umbrella ribs 5 and support ribs 6 . See FIG. 2 for reference. In some embodiments, the free arm umbrella includes three umbrella ribs 5 and three support ribs 6 .
To achieve specific or better sun-shading effect, the rotating lockout mechanism 8 is added to some embodiments. The fixing plate 1 is fixed on a wall in some embodiments. In certain embodiments, the free arm umbrella is hung on a column with the fixing plate 1 . The rotating lockout mechanism 8 enables the umbrella to swing or rotate to provide shade or protection from the elements in a user desired area. In some embodiments, rotating or swinging the umbrella includes the steps of: turning the knob handle 81 left, loosening the carriage screw 82 , loosening the first latch segment 83 and second latch segment 84 , pushing the control handle 22 , and swinging the umbrella surface from side to side. In some embodiments, fixing, locking or securing the umbrella into position includes turning the knob handle 81 right, tightening the carriage screw 82 , and engaging the first latch segment 83 and second latch segment 84 to fix the umbrella position.
In some embodiments, to facilitate user operation, in opening the umbrella with the control mechanism 7 , a user holds the control handle 22 to push the support block 21 on the second strut rod 20 into the slideway 74 of the housing 17 on the control mechanism 7 . If the spring plate 72 holds or secures the support block 21 , the umbrella can remain open. Referring to the arrow direction in FIG. 3 , pulling the spanner 73 activates spring plate 72 , thus loosening the support block 21 . Holding the control handle 22 to withdraw support block 21 from the spring plate 72 , allows a user to close the umbrella conveniently.
In another embodiment, as illustrated in FIGS. 7-13 , a type of rotation device 108 is provided that is configured to allow a free arm umbrella, as described in any of the embodiments discussed above, to swing or rotate to a user selected position and be maintained in that position. The embodiment, as illustrated in FIGS. 7-8 , can comprise one or more features of any of the free arm umbrella embodiments described above. For example, the free arm umbrella 100 can include a wall mount structure 101 , a shade providing structure including an upper hub 102 (e.g., nest), lower hub 103 (e.g., nest), and a plurality of umbrella structural members (e.g., umbrella ribs 105 , support ribs 106 , etc.), a support rod 109 , a first strut rod 110 , a second strut rod 120 , a control mechanism 107 , and a support block 121 . Any of the features of the embodiments illustrated in FIGS. 7-13 can be combined with any of the embodiments described above. The embodiments illustrated in FIGS. 7-13 can also comprise one or more different features. For example, the free arm umbrella can comprise a rotation device 108 as discussed in more detail below.
In some embodiments, the wall mount structure 101 is configured to mount the free arm umbrella 100 to a fixed structure (e.g., wall, upright surface, etc). The wall mount structure 101 can include a first portion 111 (e.g., plate, mount) for securing the free arm umbrella 100 to the fixed structure (not shown). The wall mount structure 101 can include a shaft 130 rotatably coupled to the wall mount structure 101 to enable the shade providing structure to be moved about an upright or vertical axis. In some embodiments, rotation of the shaft 130 rotates the shade providing structure.
In some embodiments, the free arm umbrella, as illustrated in FIGS. 7-13 , can include the rotation device 108 configured to allow a user to move, swing or rotate the free arm umbrella 100 about the upright or vertical axis. The vertical axis can extend in a direction parallel to an axis extending between lower and upper ends 132 , 131 of the shaft 130 which are pivotally mounted to the wall mount structure 101 . In some embodiments, the shaft 130 (e.g., cylindrical pole) is rotatably fixed to the wall mount structure 101 via one or more mounts (e.g., an upper L-shaped mount 140 and a lower L-shaped mount 142 ) that are secured to the wall mount structure 101 . In other embodiments, different shaped mounts can be used. The shaft 130 can be moveable (e.g., rotatable) relative to the mounts 140 , 142 . In some embodiments, the shaft 130 can extend through both the upper and lower mounts 140 , 142 such that the upper end 131 of the shaft 130 extends above an upper surface of mount 140 and is hingedly coupled to one end of the first strut rod 110 opposite the other end of the first strut rod 110 coupled to the lower nest 103 .
In such embodiments, a shaft 130 rotatably fixed to a wall mount structure 101 via one or more mounts provides a rotatable support structure for the free arm umbrella 100 having increased strength and robustness over other types of configurations.
In some embodiments, one end of support rod 109 can be hingedly coupled to second strut rod 120 opposite the other end of support rod 109 coupled to a lower portion of the shaft 130 either directly or indirectly via a housing 133 of the control mechanism 107 that is attached or secured to the shaft 130 . In some embodiments, one end of the support rod 109 is received within an opening of the housing 133 . The opening is positioned between two opposing sides of the housing 133 . One end of the support rod 109 is hingedly coupled to the housing 133 via a pin or rod 150 configured to extend through the two sides and opening of the housing 133 and the end of the support rod 109 . In some embodiments, second strut rod 120 can be hingedly coupled to upper nest 102 at one end and removably fixable to a lower portion of shaft 130 , either directly or indirectly via the housing 133 , at an opposite end.
In certain such embodiments, coupling one end of the support rod 109 to the housing 133 via a pin 150 extending through the two sides and opening of the housing 133 and the end of the support rod 109 , provides a more robust or durable hinged coupling. Forces can be distributed more evenly onto the pin 150 and the housing 133 .
In some embodiments, the second strut rod 120 can include two parallel rods spaced apart, extending between the upper hub 102 and the housing 133 when the free arm umbrella is in the open position. The first strut rod 110 can extend between the upper end 131 of the shaft 130 and the lower hub 130 while passing between the two parallel rods of the second strut rod 120 at a middle portion of the second strut rod 120 . The second strut rod 120 can pivotally coupled to the first strut rod 110 at the middle portion where the second strut rod 120 bisects the space between the parallel rods of the first strut rod 110 . Such a configuration allows the free arm umbrella to maintain its structural integrity and be folded up in the closed position as tightly (e.g., as small and compressed footprint) as possible.
As discussed above in previous embodiments, the free arm umbrella 100 can be moved into an open or closed position. In some embodiments, a user can hold handle 122 and push one end of second strut rod 120 , opposite the end hingedly coupled to the upper nest 102 , into engagement with the lower portion of shaft 130 or housing 133 (e.g., fixed to shaft 130 ) such that the second strut rod 120 is removably fixable to the shaft 130 or housing 133 . When the second strut rod 120 is in such an engaged position, the free arm umbrella 100 is maintained or fixed in the open position. To close the free arm umbrella 100 , the user can pull the handle 122 to disengage or release the second strut rod 120 from the shaft 130 or housing 133 and move the free arm umbrella 100 into the closed position.
As illustrated in FIGS. 11-12 , in some embodiments, the second strut rod 120 can be provided with a support block 121 at one end. The support block 121 can include an engagement member 144 (e.g., u-shaped end, etc). The support block 121 is configured to be received within the opening in the housing 133 between two opposing sides of the housing 133 . The engagement member 144 is configured to engage with and disengage from a shaft, pin or rod 146 coupled to and extending through the opening of the housing 133 . When the engagement member 144 is engaged to the rod 146 , the free arm umbrella 100 is maintained in the open position. When the engagement member 144 is disengaged from the rod 146 , the free arm umbrella 100 is moveable to the closed position. In some embodiments, the engagement member 144 is configured to form a snap-fit engagement with the rod 146 .
In certain such embodiments, such a snap-fit engagement between the engagement member 144 and rod 146 provides a less complex or more simple design. Such an engagement provides a design requiring less parts or components. The engagement member 144 can be engaged with the rod 146 in this simple, yet secure and effective manner.
In some embodiments, the control mechanism 7 includes a locking device 123 attached to the housing 133 and configured to secure or lock the second strut rod 120 in the engaged position (e.g., when the engagement member 144 is engaged to the rod 146 ). To release or disengage the second strut rod 120 from the engaged position, a user can press a bottom portion of locking device 123 and then move or pull the handle 122 to disengage the second strut rod 120 from the housing 133 .
In some embodiments, the locking device 123 includes a pivotable member 166 configured to pivot about a support structure 154 attached to the housing 133 between locked and unlocked positions. The pivotable member 166 can include a protrusion 152 located on an upper portion of the pivotable member 166 and configured to be inserted into or received within recesses 148 and 158 (e.g., apertures, windows, channels) of the support block and housing 133 in the locked position to prevent accidental disengagement of the second strut rod 120 from the housing 133 .
In some embodiments, the protrusion 152 can be configured to include a self-alignment feature. As illustrated in FIG. 13 , one end 176 of the protrusion 152 can include two generally parallel surfaces 168 and 170 on opposing sides of the protrusion 152 . At a second end 178 , the protrusion 152 includes a downward sloping surface 172 extending from surface 168 towards the opposing side of the protrusion 152 and a downward sloping surface 174 extending from surface 170 . The surfaces 168 and 170 can abut or generally follow the sides of the recess 158 such that the protrusion 152 can be self-aligned or guided into the recess 158 as the locking device 123 moves to the locked position. When the second strut rod 120 is in the engaged position, the recess 158 of the housing can be aligned with the recess 148 of the support block 121 such that a top surface of the recess 148 is positioned below a top surface of the recess 158 . In such a configuration, as the locking device 123 is moved to the locked position, the surfaces 172 and 174 of the second end 178 are downward sloping such that they can be self-aligned or guided into the recess 148 along the top surface of the recess 148 .
In some embodiments, the support structure 154 can include one or more pins 160 extending outwardly away from a central portion of the support structure 154 . The one or more pins 160 are configured to extend through one or more corresponding apertures 164 positioned on the pivotable member 166 such that the pivotable member can pivot about an axis extending longitudinally through the one or more pins 160 . The one or more pins 160 can be configured to act as a fulcrum about which the pivotable member 166 can pivot.
In some embodiments, the support structure 154 includes a biasing mechanism (not shown) (e.g., one or more springs or other elastic elements) configured to bias or maintain the pivotable member 164 in the locked position. In some embodiments, one end of the biasing mechanism abuts, contacts, or is centered on a protrusion 162 located on an interior surface of the pivotable member 164 . An opposite end of the biasing mechanism abuts, contacts, or is centered on a protrusion 156 positioned on a surface of the support structure 154 . The biasing mechanism is positioned between the surface of the support structure 154 and interior surface of the pivotable member 164 to maintain the pivotable member 164 in the locked position. The biasing mechanism and protrusions 156 , 162 can be located below the one or more pins 160 . In this type of configuration pressing or applying a force to a bottom portion of the pivotable member 166 compresses the biasing mechanism and moves a lower portion of the pivotable member 166 towards the housing 133 . As the lower portion moves toward the housing 133 , the upper portion of the pivotable member 164 moves laterally away from the housing 133 . Thus, moving the protrusion 152 out of the recesses 148 and 158 and the locking device into the unlocked position. When a user releases the force applied to the pivotable member 166 , the biasing mechanism biases the locking device 123 back to the locked position.
With reference to FIGS. 7-13 , in some embodiments, the rotation device 108 can comprise, but is not limited to a handle 121 and a biasing mechanism 128 (e.g., spring, elastic element). The handle 121 is configured to be moveably secured to the lower end 132 of the shaft 130 via the biasing mechanism 128 , a channel (e.g., recess, aperture, etc.) 126 in the lower end 132 of the shaft 130 , a pin 124 (e.g., screw, nut and bolt, etc.), and corresponding first and second sets of engagement structures 129 , 127 . In some embodiments, the pin 124 is configured to extend through an aperture 134 of the handle 122 and channel 126 . The pin 124 is coupled to a portion of the biasing mechanism 128 to secure the handle 121 to the lower end 132 of the shaft 130 and biasing mechanism 128 . Such a configuration permits the handle 122 to be moveably secured to the lower end of the shaft 132 . The pin 124 is vertically translatable up and down within the channel 126 which permits the handle 121 to be vertically translatable.
In some embodiments, the rotation device 108 is vertically translatable between a first position (e.g., an engaged or locked position) and a second position (e.g., a disengaged or unlocked position). In the first position, the free arm umbrella 100 is fixed or locked in a position selected by a user wherein the first set of engagement structures 129 (e.g., protrusions, teeth, etc.) of the handle 122 mechanically engages to or mate with the corresponding second set of engagement structures 127 (e.g., protrusions, teeth, etc.) attached to a bottom surface of mount 142 . This engagement prevents the free arm umbrella 100 from swinging or rotating about the vertical axis through the shaft 130 to different positions. A user can vertically translate the rotating mechanism 108 to the second position by holding the handle 122 and applying a downward force to the handle 122 indicated by arrow 135 . By applying a downward force, the biasing mechanism 128 is biased or compressed, as the handle 121 translates downwardly. The corresponding engagement structures 129 , 127 are disengaged as the handle 121 is translated downwardly. Upon disengagement of the corresponding engagement structures 129 , 127 , the free arm umbrella 100 is configured to be rotatable to a position selected by the user.
In some embodiments, the free arm umbrella 100 is configured to be rotatable less than or equal to about ±90, ±135, ±175 degrees from a vertical plane bisecting midpoints of the wall mount structure 101 and shaft 130 . Releasing the handle 121 of the rotation device 108 in the second position, permits the rotation device 108 to return to the first position in which the corresponding engagement structures 129 , 127 are configured to engage or mate to prevent further rotation of the free arm umbrella 100 . For example, when the handle 121 is released when the rotation device 108 is in the second position, the biasing mechanism 128 biases the rotation device 108 back to the first position in which the engagement structures 129 , 127 can engage or mate with each other.
In some embodiments, the first set of engagement structures 127 can comprise, but is not limited to, a cylindrical or circular pattern of downwardly extending teeth or protrusions, coupled to a bottom surface of mount 142 , spaced apart around the perimeter of the shaft 130 with gaps or spaces 125 positioned between each tooth or protrusion. The corresponding second set of engagement structures 129 of the rotation device 108 can comprise, but is not limited to, a corresponding pattern of teeth or protrusions and gaps extending radially inwardly from an inner surface of handle 122 configured to mate or engage with the gaps and protrusions of the first set of engagement structures 127 to prevent rotation of the free arm umbrella 100 .
In certain such embodiments, the rotation device 108 with engagement structures 129 , 127 provides a robust and easy to use design for allowing a user to rotate and selectively maintain the free arm umbrella 100 in a desired position. The protrusions or teeth of the corresponding engagement structures 129 , 127 provide a secure and strong mechanical engagement for preventing further rotation of the free arm umbrella 100 . The steps for engaging and disengaging the rotation device 108 and rotating the free arm umbrella 100 are simplified. The rotation device 108 can allow a user to simply pull the handle 121 downwardly in one motion to move the rotation device into the disengaged position and then rotate the handle to move the free arm umbrella 100 . The user can then simply release the handle 121 to return the rotation device 108 back into the engaged position. With such a rotation device 108 , the user does not have to screw or unscrew a bolt several time to move the rotation device 108 between engaged and disengaged positions. Additionally. the user can use one hand to operate the rotation device 108 and rotate the free arm umbrella.
In some embodiments, the free arm umbrella of this application features simple structure, easy operation, low cost and usability in narrow places or areas, and is suitable for large scale application.
Although specific application of this umbrella has been articulated, more uses are available. Therefore, the explanation, description and appended figures are instructive, instead of restrictive or limiting. Although these inventions have been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present inventions extend beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the inventions and obvious modifications and equivalents thereof. In addition, while several variations of the inventions have been shown and described in detail, other modifications, which are within the scope of these inventions, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combination or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the inventions. It should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed inventions. Thus, it is intended that the scope of at least some of the present inventions herein disclosed should not be limited by the particular disclosed embodiments described above. | A free arm umbrella includes a fixing plate, an upper nest, a lower nest, umbrella ribs and support ribs. The free arm umbrella also includes a control mechanism, a support rod, a first strut rod and a second strut rod. The middle part of the first strut rod is hinged with the middle part of the second strut rod. A rotating lockout mechanism can also be set on the free arm umbrella so that the umbrella cover can be rotated easily. The free arm umbrella has advantages of simple structure, convenience of use, economic practicality, and being applicable to narrow space. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 60/674,912, filed on 26 Apr. 2005 and entitled “FOOD SAMPLE COLLECTOR,” and to Ser. No. 60/625,302, filed on 5 Nov. 2004 of same title, both of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] Aspects of the present invention relate generally to improving the efficiency of pathogen detection for increasing the safety and quality of food products, and more particularly to novel methods and devices for increasing the number of independent, discrete samples taken during a pathogen detection sampling procedure, thereby increasing pathogen detection power, and providing sampling cost savings by minimizing time, material and product loss.
BACKGROUND
[0003] One of the main objectives of the food industry is to continually improve the safety and quality of its products. To accomplish this objective, the industry must constantly monitor the efficacy of implemented food safety programs. One such exemplary monitoring program involves sampling of product to verify the absence of pathogens such as Escherichia coli O157:H7, Salmonella spp., and Listeria monocytogenes.
[0004] Current food sampling techniques, as performed by the industry, are primarily manual procedures that involve either cutting of food pieces, or swabbing surfaces using sponges. These procedures consume substantial time and material, are laborious, and promote product contamination via multiple handling steps.
[0005] Typical sampling plans for meat products follow a ‘two-class’ attribute plan, based on testing for the presence (positive result) or absence (negative result) of an organism. For example, following conventions set forth by the International Commission on Microbiological Specifications for Foods (ICMSF) (ICMSF; Microorganisms in Foods, Kluwer Academic/Plenum Publishers, 2002), for ‘two-class’ attribute plans, the probability of acceptance (P a ) for a lot is a function of three factors. The first is the actual incident rate (IR) of E. coli O157:H7 in a lot at a given sampling point. The second is “n”, representing the number of sample units collected for the lot, and the third is “c”, representing a maximum allowable number of sample units yielding unsatisfactory results for the lot.
[0006] The US Department of Agriculture Food Safety Inspection Service has a zero tolerance level for E. coli O157:H7 in non-intact beef products (see USDA-FSIS: United States Department of Agriculture Food Safety and Inspection Service; 1999 FSIS Policy on non-intact raw beef products contaminated with E. coli O157:H7; Food Safety and Inspection Service, U.S. Department of Agriculture, Washington, D.C. (available online; http://www.fsis.usda.gov/OA/background/O157policy.htm)). A significant consequence of the USDA-FSIS zero tolerance level for E. coli O157:H7 is that a lot of product is defective as soon as a positive result is obtained from a sample unit. No sampling plan can guarantee the complete absence of a pathogen unless all material in the lot is sampled, which is a practical impossibility. Furthermore, it is not yet commercially possible to produce product that is completely free of pathogens. Therefore, it is impossible to a priori design a sampling plan that will meet USDA-FSIS requirements. However, it would be highly desirable to improve the level of confidence of detecting pathogens in meat products if they are present.
[0007] Therefore, there is a pronounced need in the art for methods and apparatus to increase the power of detection for pathogens present in, e.g., meat products. There is a pronounced need in the art for methods and devices allowing for more sanitary sampling with reduced sample handling, and that allow for increased speed of sampling. There is a pronounced need in the art for methods and devices allowing for reduction of the cost of sampling materials, and for devices and equipment that may be easily sterilized prior to reuse. There is a pronounced need in the art for methods and devices enabling reduction of product loss by allowing for sampling smaller discrete pieces. There is a pronounced need in the art for methods and devices that allow for increasing the power of pathogen detection by taking a significantly higher number of representative samples in a cost-effective manner that reduces product waste, while precluding the necessity to sample all material.
SUMMARY OF THE INVENTION
[0008] The present invention provides novel methods and devices for detection of pathogens or other microbes in various analyzed samples (e.g., food, industrial, pharmaceutical, botanical, environmental, etc.).
[0009] In preferred aspects, a novel surface sampling device for bulk solid foods is provided. The inventive sampling device operates to remove (e.g., shave) small pieces from, for example, each product piece that it comes into contact with. The device comprises a sampling mechanism having utility to remove samples (e.g., cut slivers from), for example, larger pieces of food. In particular embodiments, the device is a two-part unit comprising primary shaft member (e.g., cylindrical stainless steel), and a housing comprising one or more shaving means. Alternately, the device may be unitary, or effectively unitary, comprising shaft and sampling elements.
[0010] The novel methods and devices provide for increasing the power of detection for pathogens on food surfaces by increasing the number of independent, discrete samples taken during the sampling procedure. The inventive sampling devices reduce sampling costs by minimizing time, material and product loss relative to prior art sampling techniques.
[0011] Particular aspect provide a surface sampling device for increasing the number of discrete surface samples taken during sampling of a multi-piece sample, comprising: a cylindrical housing having external and internal surfaces defining a housing wall, a sample-proximal end having an opening therein, a sample-distal end having an opening therein, and an internal channel between the ends, the channel generally defining an axis and a forward direction toward the sample-proximal end; at least one aperture within the housing wall, the aperture in communication with the internal channel and comprising a directional sample cutting or shaving surface at an external edge thereof, the directional cutting or shaving surface operative with the aperture upon rotation of the housing, to direct cuttings or shavings toward the internal channel; and a shaft member having a diameter less than the internal housing diameter and receivable into the housing at the sample-proximal housing end, the shaft member comprising: a sample-distal shaft end insertable through and extending beyond the sample-distal housing end opening; a sample-proximal shaft end-cap receivable into the sample-proximal housing end opening to seal the opening; a shaft attachment member positioned on the shaft between the distal shaft end and the shaft end-cap, the attachment member receivable into the sample-distal housing end and positioned at a distance from the shaft end-cap to hold the end-cap in sealable communication with the sample-proximal housing end opening; and a piston in communication with the internal housing surface and positioned on the shaft between the shaft attachment member and the shaft end-cap and defining a sample collecting chamber within the internal channel between the piston and the end-cap, and wherein the at least one aperture is in communication with the collecting chamber.
[0012] Preferably, the shaft attachment member is threaded and receivable into complementary thread receiving means in the sample-distal housing end to lock the housing onto the shaft. In particular embodiments, the threads are reverse threaded with respect to an operative rotational direction of the sampling device. In certain embodiments, the at least one aperture comprises an elongated opening running parallel to the housing channel axis. In particular aspects, the at least one aperture is framed with a turned-down or beveled leading edge, with respect to a direction of rotation, and a sharpened trailing edge to allow the device, during rotational operation thereof to perform a cutting or shaving action. Preferably, the device comprises a plurality of apertures, either positioned randomly along the wall of the sample collecting chamber or positioned in a symmetrical array along the wall of the sample collecting chamber. In certain aspects, the shaft diameter is less than one-half the outside diameter of the piston.
[0013] Additional aspects provide a method for enhanced sampling of multi-piece samples, comprising: obtaining a test sample comprising multiple pieces; rotating one of the sampling devices described herein by rotating the sample-distal shaft end extending beyond the sample-distal housing end opening; introducing the rotating sampling device into the test sample to obtain multiple sample surface cuttings or shavings from the multiple pieces or from a representative fraction thereof; and recovering the multiple sample surface cuttings or shavings from the device to provide for a collected sample comprising discrete surface samples. Preferably, ‘introducing’ comprises at least one repetition of forward introduction of the device into the test sample and retrieval of the device in the reverse direction from the test sample. Preferably, there is a plurality of repetitions through different sampling paths within the test sample. In particular aspects, recovering the multiple sample surface cuttings or shavings from the device comprises unlocking the shaft from the housing, removing the shaft from the housing to expose the piston, and recovering the surface cuttings or shavings from the sample collecting chamber and the at least one aperture.
[0014] Yet further aspects provide a surface sampling device for increasing the number of discrete surface samples taken during sampling of a multi-piece sample, comprising: a cylindrical member having and external surface, a sample-proximal end, a sample-distal end, the cylindrical member generally defining an axis and a forward direction toward the sample-proximal end; at least one channel extending into the cylindrical member from the external surface thereof, the channel comprising a sample collection chamber and a directional sample cutting or shaving surface at an external edge thereof, the directional cutting or shaving surface operative with the channel, upon rotation of the cylindrical member, to direct cuttings or shavings into the channel and collection chamber; and a cylindrical shaft integral with, or lockingly receivable into the cylindrical member at the sample distal end thereof, the cylindrical shaft suitable to operatively rotate the cylindrical member when rotational force is applied to the cylindrical shaft. In particular embodiments, the at least one channel comprises an elongated opening running parallel to the axis of the cylindrical member. Preferably, the at least one channel is framed with a turned-down or beveled leading edge, with respect to a direction of rotation, and a sharpened trailing edge to allow the device, during rotational operation thereof to perform a cutting or shaving action. In particular aspects, there is a plurality of channels positioned either randomly along the external surface of the cylindrical member, or positioned in a symmetrical array along the external surface of the cylindrical member.
SUMMARY OF THE DRAWINGS
[0015] FIGS. 1A , 1 B, 1 C and 3 show an exemplary sampling device 2 comprising a two-part unit having a primary shaft member (e.g., cylindrical stainless steel) 4 , and a housing 6 comprising one or more shaving means 8 .
[0016] FIG. 2 , shows, according to exemplary aspects of the present invention, the difference in power of detection based on sampling an n=25 and n=100.
[0017] FIG. 3 , shows, according to a preferred embodiment, representative dimensions for several of the device elements of FIG. 1A .
[0018] FIG. 4A shows an additional exemplary embodiment of an inventive sampling device.
[0019] FIG. 4B shows another exemplary embodiment of an inventive sampling device.
[0020] FIGS. 5 , 6 , 7 and 8 show use of an exemplary embodiment to obtain a sample of a food product (e.g., meat trimmings). FIG. 5 shows the embodiment of FIG. 4A attached to an electric drill. FIG. 6 shows the exemplary embodiment of FIG. 1C used to collect a sample of food. FIG. 7 shows a similar sample collected using the embodiment of FIG. 4A , and shows that the sampled (e.g., shaved and grated) food product is contained in the well of the fluted opening. FIG. 8 shows how the sample collected from the embodiment of FIG. 1C can be removed for subsequent laboratory analysis.
[0021] FIG. 9 shows a sample, collected with the embodiment of FIG. 4A , separated into individual pieces.
[0022] FIGS. 10A , 10 B, 10 C, 11 and 12 show further aspects of the invention in obtaining a composite sample consisting of a large number of discrete sample units. FIGS. 10A , 10 B and 10 C show portions of beef (approximating the size and nature of those found in ‘combos’ during the production of beef products) spray painted to distinctively mark their surfaces. FIG. 11 shows the embodiment of FIG. 4B after it was withdrawn from the container containing the discrete colored layers. Many colors are represented in the collected sample contained in the well of the fluted opening. FIG. 12 shows the collected sample after removal from the well of the fluted opening, and confirms that the embodiment removed discrete portions of material from all of the discrete colored layers present in the container.
[0023] FIG. 13 shows several exemplary devices constructed with vertical (longitudinal) flute openings (e.g., cavities).
[0024] FIGS. 14A , 14 B and 14 C show several exemplary flute designs. FIG. 14A shows an exemplary four-flute design with non-beveled cutting edges. FIG. 14B shows an exemplary four-flute design with beveled cutting edges. FIG. 14C shows an exemplary three-flute design with non-beveled cutting edges.
DETAILED DESCRIPTION OF THE INVENTION
[0025] In particular aspects, the present invention provides a surface sampling device for bulk solid foods. The device shaves small pieces of each product that it comes into contact with. The principle operation of the sampling device involves the use of a shaving mechanism to cut slivers from larger pieces of food.
[0026] In particular embodiments, and with reference to FIGS. 1A , 1 B, 1 C and 3 , the sampling device 2 comprises a two-part unit having a primary shaft member (e.g., cylindrical stainless steel) 4 , and a housing 6 comprising one or more shaving means 8 (in this exemplary embodiment shown as an opening in the housing, the opening framed with a turned-down leading edge and a sharpened trailing edge).
[0027] The primary shaft member 4 comprises an end-cap 10 , a stationary-piston 12 , and a threaded shaft member 14 . The end-cap 10 prevents the device from performing a coring action which would limit the amount of discrete samples that may be made. The stationary piston 12 facilitates the removal of shaved/cut food slivers from the shaving tube. The threaded shaft member 14 (counter-clockwise or reverse threaded to ensure that the tube does not unscrew during clockwise or opposite rotary operation) allows the shaving tube to be locked onto the primary shaft during sampling.
[0028] The primary shaft 4 acts as the main framework for supporting the shaving tube and (in cooperation with the shaving tube 6 ) houses collected food shavings, while also acting as a removable stationary piston suitable to expel product collected inside the tube into a sampling bag for further analyses.
[0029] The shaving tube 6 comprise a threaded housing member 16 , cooperative with the threaded shaft member 14 . The shaving tube 6 also comprises one or more openings 8 (e.g., elongated openings running parallel to the tube axis), each opening framed with a turned-down leading edge (refereeing to the direction of rotation) and sharpened trailing-edge to allow the device, during operation, to perform a grating/cutting action. The openings 8 act to slice or shave, and are responsible for contacting food surfaces and shaving slivers of food during rotation of the device. Alternatively, it is possible to use grater type shaving surfaces, or other means suitable to slice or shave pieces from contacted surfaces.
[0030] The sampling device 2 is inserted (e.g., into the chuck) in an electric drilling tool to generate the rotary action of the device and allow the slicers (e.g., vertically elongated) to perform cuts of food by passing rapidly over the food surface.
EXAMPLE 1
Novel Sampling Procedure Using the Inventive Sampling Device
[0031] In a further aspect, the invention provides a novel sampling procedure, comprising the following steps:
[0032] In step 1 , placing the shaving tube 6 onto the primary shaft 4 .
[0033] In step 2 , locking the shaving tube 6 into place on the shaft's threaded-housing member 16 , using, for example, counter-clockwise threads (reverse threaded with respect to the direction of rotation).
[0034] In step 3 , the shaft-end of the device 18 is locked into the end of a drill tool.
[0035] In step 4 , the drill tool is powered on and the sampling device 2 turns, for example, in a clockwise direction at the selected speed allowing the user to take samples from any food surface.
[0036] In step 5 , the shaving tube 6 is unlocked from the primary shaft 4 (e.g., by turning the tube counter-clockwise.
[0037] In step 6 , the shaving tube 6 is drawn back passed the stationary piston 12 , allowing the sample to be expelled on the exposed portion of the shaft 20 .
[0038] In step 7 , the sample is deposited into a sample collection bag.
EXAMPLE 2
Operating Characteristics Evaluation
[0039] As stated herein above, sampling plans for meat products follow two-class attribute plans based on testing for the presence (positive result) or absence (negative result) of an organism. Following conventions set forth by the International Commission on Microbiological Specifications for Foods (ICMSF; 2002. Microorganisms in Foods, Kluwer Academic/Plenum Publishers), for two-class attribute plans the probability of acceptance (P a ) for a lot is a function of three factors. The first is the actual incident rate (IR) of E. coli O157:H7 in the lot at the sampling point. The second is “n”, representing the number of sample units collected for the lot. The third is “c”, representing the maximum allowable number of sample units yielding unsatisfactory results for the lot.
[0040] Following ICMSF conventions, comparative values of P a were computed using an operating characteristic function, and depicted as an operating characteristic (OC) curve. OC curves were generated using Sampling Plan Analyzer from Taylor Enterprises, Inc. The function used was to evaluate sampling plans for single defects (positive for pathogen) from a pool of representative stratified samples (where a stratified sample is one where it is specified that equal number of samples should come from different parts of the lots).
[0041] P a , values were computed by assigning values to each of the three factors described above. First, the incident rates of E. coli O157:H7 in fresh beef trim in combo-bins prior to shipping was estimated based on available literature. Second, the “n” values from the two lot acceptance sampling plans were used. Lastly, for the case of zero tolerance, “c” was set to zero (c=0). The difference in power of detection based on sampling an n=25 and n=100 is represented in FIG. 2 .
[0042] Furthermore, TABLE 1 (below) emphasizes the importance of increasing the number of discrete samples in order to increase power of detection for product contaminated with pathogens. With low sample numbers such as n=5, the probability of accepting a lot that is more contaminated (i.e., 5%) is 77% whereas that using a higher sample number such as n=100 drops to 0.6%. This is a significant difference and illustrates the importance for using a sampling procedure that increases the number of discrete samples taken to ensure that product contaminated with pathogens is not accepted but detected and removed or reworked.
[0000]
TABLE 1
Probability of acceptance for various incident rates as a function of sampling number (n).
Probability of Acceptance (P a ) for various n values
Incident Rate
P a for n = 5
P a for n = 10
P a for n = 15
P a for n = 20
P a for n = 25
P a for n = 100
0.0
1
1
1
1
1
1
0.1
0.995
0.990
0.985
0.980
0.975
0.905
0.2
0.990
0.980
0.970
0.961
0.951
0.819
0.3
0.985
0.970
0.956
0.942
0.928
0.740
0.4
0.980
0.961
0.942
0.923
0.905
0.670
0.5
0.975
0.951
0.928
0.905
0.882
0.606
0.6
0.970
0.942
0.914
0.887
0.860
0.548
0.7
0.965
0.932
0.900
0.869
0.839
0.495
0.8
0.961
0.923
0.886
0.852
0.818
0.448
0.9
0.956
0.914
0.873
0.835
0.798
0.405
1.0
0.951
0.904
0.860
0.818
0.779
0.366
1.2
0.941
0.886
0.834
0.785
0.739
0.299
1.4
0.932
0.868
0.809
0.754
0.703
0.244
1.6
0.923
0.851
0.785
0.724
0.668
0.199
1.8
0.913
0.834
0.762
0.695
0.635
0.163
2.0
0.904
0.817
0.739
0.668
0.603
0.133
2.5
0.881
0.776
0.684
0.603
0.531
0.080
3.0
0.859
0.737
0.633
0.544
0.467
0.048
3.5
0.837
0.700
0.586
0.490
0.410
0.028
4.0
0.815
0.665
0.542
0.442
0.360
0.017
4.5
0.794
0.631
0.501
0.398
0.316
0.010
5.0
0.774
0.599
0.463
0.358
0.277
0.006
EXAMPLE 3
Additional Embodiment
[0043] FIG. 4A shows an additional exemplary embodiment of an inventive sampling device. In this embodiment the sampling device comprises a primary shaft member (e.g., cylindrical stainless steel) terminating in a shaving member (e.g., cylindrical tube). The primary shaft member and the shaving member (e.g., cylindrical shaving tub) may be a single unit formed of a unitary material, may be comprised of two units (e.g., a primary shaft, and a shaving member) permanently jointed (e.g., welded together), or may be removably joined (e.g., by means of threads and thread receiving means). Preferably, the sampling device is a unitary member, or is comprised of a primary shaft member and a shaving member permanently joined (e.g., by welding) to minimize potential contamination areas.
[0044] The shaving member (e.g., cylindrical tube) in this example comprises one or more longitudinal (relative to the shaft member) open channels or cavities (e.g., shown as longitudinal fluted openings in the example of FIG. 4A ). With respect to a direction of shaving member rotation, each flute is framed with a turned-down leading edge and a sharpened trailing edge such that, during operation, the sampling device performs a grating/cutting action with respect to materials through which it may pass (e.g., food samples, meat samples or trimmings, vegetable samples or trimmings, etc.). During operation (e.g., rotational operation), the fluted openings act to contact the surfaces to be sampled (e.g., food surfaces), and remove (e.g., by excising, slicing, shaving, scraping, etc), samples (e.g., slivers of food). The sampled sample is retained in (e.g., along the bottom) the fluted groove or grooves.
[0045] FIG. 4B shows another exemplary embodiment. This embodiment is similar to that shown in FIG. 4A . There are three (3) fluted openings, and the cutting edge has an effective higher profile relative to the circumference of the circular shaft, which results in a more aggressive cutting action (e.g., thicker slices are removed from the sample during sampling with the device).
[0046] FIGS. 5 , 6 , 7 and 8 show use of an exemplary embodiment to obtain a sample of a food product (e.g., meat trimmings). FIG. 5 shows the embodiment of FIG. 4A attached to an electric drill, which provides a preferred means to turn (e.g., rotate) the embodiment as it passes through (e.g., penetrates down through) food being sampled. An electric drill can turn the exemplary sampling device in a reproducible manner, and at a speed sufficient such that the momentum of the cutting edge ensures that a smooth cut ensues instead of ‘grabbing’ the product.
[0047] Alternatively, the exemplary embodiment can be turned by grasping and rotating the shaft by hand. Alternatively, a ‘t’ bar head (e.g., consisting of a short bar affixed at right angles to the main shaft, and at the end opposite of the shaving member (e.g., shaving tube)) can be added or operationally attached to the embodiment, and the embodiment can be turned by grasping the ‘t’ bar head and using it to rotate the shaft.
[0048] FIG. 6 shows the exemplary embodiment of FIG. 1C used to collect a sample of food. In this example, the food consists of portions of beef approximating the size and nature of those found in ‘combos’ (combo bins) during the production of beef products.
[0049] FIG. 7 shows a similar sample collected using the embodiment of FIG. 4A , and shows that the sampled (e.g., shaved and grated) food product is contained in the well of the fluted opening.
[0050] FIG. 8 shows how the sample collected from the embodiment of FIG. 1C can be removed for subsequent laboratory analysis.
[0051] FIG. 9 shows a sample, collected with the embodiment of FIG. 4A , separated into individual pieces. The number of discrete portions was found to be over 170. In addition, a portion of the sample was found to consist of a ‘paste’ of discrete portions too small to differentiate. Referring to TABLE 1 of EXAMPLE 2 herein, this number of discrete portions is highly desirable with respect to reducing the probability of accepting a lot containing a low incidence rate of undesirable contaminant.
[0052] Further investigation of the ability of the invention to obtain a composite sample consisting of a large number of discrete sample units is shown in FIGS. 10A , 10 B, 10 C, 11 and 12 . FIGS. 10A , 10 B and 10 C show portions of beef (approximating the size and nature of those found in ‘combos’ during the production of beef products) spray painted to distinctively mark their surfaces. The colored portions of beef were placed into a container similar to that shown in FIG. 6 , one color at a time, so as to form a series of discrete colored layers. This collection was sampled using the embodiment of FIG. 4B , and in a manner similar to that shown in FIGS. 5 , 6 , 7 and 8 .
[0053] FIG. 11 shows the embodiment of FIG. 4B after it was withdrawn from the container containing the discrete colored layers. As can be seen in FIG. 11 , many colors are represented in the collected sample contained in the well of the fluted opening. FIG. 12 shows the collected sample after removal from the well of the fluted opening, and confirms that the embodiment removed discrete portions of material from all of the discrete colored layers present in the container. Again referring to EXAMPLE 2 herein, this result confirms that the embodiment collects a large number of independent sample units from the mass being sampled.
Exemplary Materials of Construction
[0054] The device may be constructed of materials which are acceptable in the food industry. Acceptable materials for fabricating the cutting edge include all materials that have previously found use in the food industry. Examples include, but are not limited to the following materials:
[0055] Stainless steels—including those metal alloys that consist of about 10.5% or more Chromium (Cr) and more than about 50% Iron (Fe). For example, cutting edges formed from Martensitic, or hardenable stainless steels, are suitable. Martensitic stainless steels by convention are classified in the 400 series, usually with 11.5% chromium up to 18% chromium, with higher levels of carbon than ferritics, and are capable of being heat treated to a wide range of hardness and strength levels. An example of an acceptable Martensitic stainless steel is Grade 420 with alloy composition <0.15% C, 12.0-14.0% Cr, <1.0% Mn, <1.0% Si, <0.04% P, >0.03% S and balance Fe;
[0056] Cobalt/Chromium “Superalloy” stainless steels—Examples include the commercial materials Impervium® and Talonite®. The chemical breakdown of Talonite® is <3% Ni, <2% Si, <3% Fe, <3% Mn, 28-32% Cr, <1.5% Mo, 3.5-5.5% Tu, 0.9-1.4% C, and balance Co;
[0057] High carbon steels—metal alloys which contain a high proportion of carbon. This type of steel makes the best performing blades in terms of edge retention, toughness and ease of sharpening. It is commonly referred to as tool steel. The drawback associated with high carbon steel is that it is not stain resistant and will rust and discolor over time. An example of an acceptable carbon steel alloy is D-2 is a high carbon tool steel that has a high chromium content (1.5% C, 0.3% Mn, 0.3% Si, 12% Cr, 0.75% Mo and 0.9% V and balance Fe);
[0058] Ceramics—Examples include stabilized zirconium oxide commonly used on consumer knives; and
[0059] Aluminum or aluminum alloys may also be used.
Preferred Design Details
[0060] Several devices were constructed with vertical (longitudinal) flute openings (e.g., cavities), as shown in FIG. 13 . A comparison between a 3-flute design with a beveled cutting edge and a 3-flute design with a non-beveled cutting edge showed that the beveled design with its more aggressive exposed cutting edge collected more distinct pieces of product having a greater size range (from large to small pieces) than the non-beveled version (mostly small pieces). Furthermore the distinct pieces collected by the beveled version composed 37.9% of the total sample weight compared to 30.5% for the non-beveled design, with the remainder in both cases consisting of small shavings and paste too small to differentiate.
[0061] Several exemplary flute designs are shown in FIGS. 14A , 14 B and 14 C. FIG. 14A shows an exemplary four-flute design with non-beveled cutting edges. FIG. 14B shows an exemplary four-flute design with beveled cutting edges. FIG. 14C shows an exemplary three-flute design with non-beveled cutting edges.
[0062] The exemplary devices may comprise one or more sampling openings or channels (e.g., flutes). The only restriction is that the number of flutes times the flute opening size (along the circumference) must be less than the circumference of the shaving tube. The tube itself may be of any diameter. Preferably, the diameter is great enough so that the flute openings can contain enough material to satisfy laboratory sampling requirements. Preferably, the diameter should be small enough so that it is possible to force the shaving tube through the material being sampled without excessive resistance. In the embodiment of FIG. 13 , the flute openings of approximately 0.375 inches wide by 1 foot long were machined onto a cutting tube of diameter 1.25 inches. This allowed the collection of between 75 and 100 grams of material, for a test which required 75 grams or more.
[0063] An alternative opening/channel/flute arrangement is in the form of a spiral helix. All of the variations in shape, number, and beveled vs. non-beveled cutting edge may still be applied in the context of a helix design The helix angle design will tend to move the collected sample out of the way toward the butt end of the auger, where an optional chamber to store sampled food may be located.
[0064] The inventive food sampling devices allow for collection of several hundred discrete samples from food product in less time and with less product loss than current procedures. | The present invention provides novel methods and devices for detection of pathogens or other microbes in an analyzed sample (e.g., food, industrial, pharmaceutical, botanical, environmental etc., sample). The inventive methods and devices provide for increasing the power of detection for pathogens on food surfaces, comprising increasing the number of independent, discrete samples taken during the sampling procedure. The inventive sampling device reduces sampling costs by minimizing time, material and product loss relative to prior art sampling techniques. In particular aspects, a novel surface sampling device for bulk solid foods is provided that operates to remove (e.g., shave) small pieces from contacted product (e.g., product pieces). The device comprises a sampling mechanism having utility to remove samples (e.g., cut slivers from) larger pieces of food or other sample materials. In particular embodiments, the device comprises a primary shaft member (e.g., cylindrical stainless steel), and a shaving means. | 2 |
This application claims the benefit of U.S. Provisional Patent Application No. 61/683,884, filed Aug. 16, 2012.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention is directed to manufacturing of decorative trim such as cornices that provide for detailed woodworking features and architectural structures.
2. Description of Prior Art
Prior art devices of this type have been developed to enable different trim and finish molding venues, see for example U.S. Pat. Nos. 3,956,861, 4,706,431, 5,444,956 and U.S. Pat. No. 7,168,474.
U.S. Pat. No. 3,956,861 discloses a trim arrangement for interior partitions wherein a partition panel has a channel for receiving fasteners and a cover concealment strip which is frictionally inserted therein.
U.S. Pat. No. 4,706,431 claims a recessed decorative molding for wood paneling having a groove for receiving a decorative strip insert for use in a wood door panel.
U.S. Pat. No. 5,444,956 is directed to a trim molding with removable insert. A trim molding has an elongated channel into which a backing is positioned with an overlying abutting cut-away insert so as to expose a portion of the locking insert therethrough.
U.S. Pat. No. 7,168,474 is directed towards a decorative device comprised of modular interchangeable components which has a cornice for crowning an architectural structure with a decorative center piece in the cornice which is applied therein to provide interest.
SUMMARY OF THE INVENTION
A multi-part decorative trim molding assembly to simulate a hand carved decorative trim piece with relief surfaces. A base molding has a contrasting material upstanding insert in a recessed channel. A U-shaped “tunnel” molding trim having intermediate portions cut-away is inverted and straddles the upstanding insert to provide a true recessed independent composite insert configuration wherein the tunnel molding trim is spaced in relation to the upstanding contrasting material insert within the base molding.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of an assembled trim molding of the invention illustrating the multiple insert openings therewithin.
FIG. 2 is a perspective view of a portion of the assembled molding configuration.
FIG. 3 is a top plan view of a portion of the insert trim.
FIG. 4 is a side elevational view thereof.
FIG. 5 is a bottom plan view thereof.
FIG. 6 is a partial exploded perspective view of the trim molding assembly of the invention.
FIG. 7 is a partial perspective view of a base trim of an alternate form of the invention.
FIG. 8 is a cross-sectional view of an alternate trim molding assembly of the invention.
FIG. 9 is an exploded cross-sectional view of a second alternate trim molding assembly of the invention.
FIG. 10 is an exploded top plan view of a third alternate form of the invention.
FIG. 11 is a front elevational view of the third alternate assembly thereof.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 6 of the drawings, the trim molding assembly 10 of the invention can be seen having a base mounting molding 11 , a decorative insert strip 12 and a U-shaped apertured viewing insert 13 . The base receiving mounting molding 11 comprises an integral elongated strip of milled material 14 , in this example preferably wood. The top surface being contoured with a first contoured surface portion 15 extending inwardly from an upstanding perimeter edge 16 . A receiving channel 17 extends longitudinally within defining the inward terminal edge at 18 of the concave surface portion 15 as best seen in FIG. 6 of the drawings.
An opposite spaced parallel edge at 19 of the channel 17 defines the transverse dimension thereof. An angled top surface portion 14 extends from the terminal edge 19 in a convex surface contour at 20 which transitions into a curvilinear concave surface portion 21 with a rounded over upstanding parallel base perimeter edge portion 22 .
A flat bottom or back surface 23 interconnects said respective upstanding portions 22 and 16 completing the base receiving mounting molding 11 .
The decorative channel insert strip 12 can be seen best in FIGS. 1 and 6 of the drawings comprises in this example an elongated cross-sectionally rectangular material having a transverse dimension substantially less than that of the corresponding channel dimension 17 and is positioned midway therein in spaced side to side relation forming corresponding receiving channels 24 A and 24 B.
The decorative insert molding strip 12 may be of a different material to that of the base 11 , such as a varied wood variety or a contrasting “stain” color.
Alternately, a veneer overlay 25 can be pre-applied to the exposed upper surface 12 A of the strip 12 by conventional adhesion bonding techniques well know within the art. The veneer overlay 25 may be of any material including wood veneers or other contrasting non-wood materials.
The key structural element to the trim molding assembly 10 of the invention is the inverted for installation U-shaped insert strip 13 , best seen in FIGS. 5 and 6 of the drawings. The insert strip 13 is, as noted, of a generally inverted U-shaped having oppositely disposed leg portions 13 A and 13 B with an integral interconnecting contoured top 26 therebetween. A plurality of longitudinally spaced view port openings 27 are formed therein extending inwardly from the contoured top 26 to midway in the respective leg portions 13 A and 13 B. The openings 27 define parallel spaced exposed leg edge surfaces 28 A and 28 B with oppositely disposed spaced contoured top exposed edge surfaces 29 A and 29 B.
The longitudinal length of each of the respective view port openings 27 as illustrated in FIGS. 2 , 3 , 4 and 5 of the drawings is proportional to the intermediate remaining top 26 and leg areas 30 therebetween indicated generally and depending on the design venue of the application chosen which in this example is approximately one-half the length thereof.
The transverse width of the insert viewing strip 13 is also variable depending on the design requirements of the use application.
Referring now to FIG. 6 of the drawings, the assembly sequence of the trim molding assembly 10 can be seen wherein the base receiving molding 11 having the recessed channel 17 therein is illustrated with the initial placement of the decorative strip 12 within. The viewing insert 13 is then positioned thereover with the legs 13 A and 13 B registerable with the corresponding defined receiving areas 24 A and 24 B in the channel 17 as the hereinbefore defined by the insert position strip 12 .
As noted, the decorative strip 12 may have a veneer overlay 25 as illustrated in the assembled molding in FIG. 1 of the drawings and in FIG. 6 of the drawings.
Referring now to FIG. 7 of the drawings, an alternate form of the invention 31 can be seen wherein a decorative strip 32 is formed integral within a channel 33 in a base molding 34 which may be required in some venues.
Referring now to FIGS. 8 and 9 of the drawings, multiple alternate trim molding forms can be seen at 35 and 36 wherein a two-part base molding 35 A and 35 B in FIGS. 8 and 36A and 36 B in FIG. 9 of the drawings.
The base molding 35 A has a receiving area 37 formed therein which allows for the insertion of a decorative strip 38 , such as contrasting material or veneer with a U-shaped apertured viewing insert 39 positioned thereover similar to the strip 13 as set forth and described in the primary form of the invention.
In this example, an additional base molding portion 35 B is attached to one end of the base molding 35 A by the utilization of an elongated backing strip 40 . Both the base molding 35 A and base molding portion 35 B have attachment channels 41 A and 41 B respectively in their non-viewing reverse surfaces 42 and 42 . The backing strip 40 has oppositely disposed upstanding flanges 42 A and 42 B will, upon assembly, be registerably engaged within the respective attachment channels 41 A and 41 B securing the multiple part molding assembly together.
A similar assembly can be seen in FIG. 9 of the drawings wherein the base molding 36 has the two-piece assembly 36 A and 36 B with corresponding attachment channels 43 A and 43 B therein respectively. As described previously, a backing strip 44 having oppositely disposed upstanding engagement flanges 45 A and 45 B is registerable within corresponding aligned elongated receiving channels 46 A and 46 B within the non-viewable sides of the respective two-part molding base as hereinbefore described in spaced aligned relation to one another.
In this example, an independent U-shaped aperture viewing insert 47 and a decorative insert 48 are held between the respective interengaged molding bases 36 A and 36 B completing the decorative multi-part molding 36 form of the invention.
Referring now to FIGS. 10 and 11 of the drawings, a curved trim molding assembly 49 can be seen where like in the primary trim molding assembly 10 , an elongated contoured base portion 50 in this configuration curved, has a receiving channel 51 formed therein. A decorative insert strip 52 is positioned within the channel with a correspondingly curved U-shaped apertured viewing insert 53 is correspondingly positioned therewithin to achieve the complete curved trim molding assembly 49 having the same unique visualization of the hereinbefore primary and secondary and third forms of the invention, previously described.
It will thus be seen that a new and novel decorative molding with multiple relief insert has been illustrated and described and it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention. Therefore I claim: | A decorative molding assembly for a variety of surface applications providing a complex molding feature with a machine made single component set composite configured insert. A channel base molding receives a unique configured U-shaped insert forming linear spaced and aligned viewing openings for an underlying contrasting base material achieving a hand crafted detailed look with a single overlying molding tunnel insert combination. | 4 |
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to combustion devices and, more particularly, to emission control systems for combustion devices.
[0002] During a typical combustion process within a furnace or boiler, for example, a flow of combustion gas is produced. The combustion gas contains combustion products including, without limitation, carbon dioxide, carbon monoxide, water, hydrogen, nitrogen and mercury generated as a direct result of combusting solid and/or liquid fuels. Before the combustion gas is emitted into the atmosphere, hazardous or toxic combustion products, such as mercury emissions and oxides of nitrogen (NO x ), are to be removed according to EPA or state governmental regulations, standards and procedures.
[0003] At least some conventional methods of removing mercury from combustion gases include injecting activated carbon into the combustion gas as the combustion gases flow through duct work. However, with such methods, it may be difficult to obtain uniform distribution of the particulate matter within the duct work. As a result of poor mixing and/or carbon fallout, mercury may not be efficiently removed from the combustion gases. In an attempt to solve such problems, an injection rate of activated carbon is increased, which may further exacerbate the problems associated with the conventional methods.
BRIEF DESCRIPTION OF THE INVENTION
[0004] In one aspect, a method is provided for reducing mercury emissions using at least a solid fuel, furnace and flue gas system assembly. The method includes receiving a flow of fuel including mercury at the furnace assembly, injecting a flow of a solution including injecting a flow of mercury oxidizer MgCl 2 , and oxidizing the mercury using the mercury oxidizer MgCl 2 and furnace assembly.
[0005] In another aspect, a furnace assembly is provided. The assembly includes a furnace combustion zone configured to facilitate at least an oxidation reaction of mercury. The assembly also includes a first injection port positioned at the furnace combustion zone. The injection port is configured to inject a flow of mercury oxidizer MgCl 2 .
[0006] In a another aspect, a furnace combustion zone exhaust system includes a combustion chamber configured to combust materials including mercury such that mercury exits the combustion chamber in a flow of exhaust. The system also includes a furnace configured to facilitate at least an oxidation reaction of mercury and a second injection port positioned downstream of the furnace combustion zone. The second injection port is configured to inject a flow of mercury oxidizer MgCl 2 .
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a schematic view of a exemplary power plant system in accordance with one aspect of the invention;
[0008] FIG. 2 is a schematic view of a exemplary power plant system that may be used to facilitate removing mercury emissions from combustion gases generated with the power plant system shown in FIG. 1 ; and
[0009] FIG. 3 is a schematic view of an exemplary power plant system that may be used to facilitate removing mercury emissions from combustion gases generated with the power plant system shown in FIG. 1 and FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
[0010] An exemplary embodiment of the present invention provides a method and system for continuously removing and reducing hazardous and/or toxic compounds, such as mercury emissions from a flow of combustion gas produced during a combustion process within a furnace or boiler, for example. The flow of combustion gas having combustion products including, without limitation, carbon dioxide, carbon monoxide, water, hydrogen, nitrogen and mercury. This combustion gas is a direct result of combusting solid and/or liquid fuels. Before the flow of combustion gas is exhausted into the atmosphere, any toxic combustion products, such as mercury and oxides of nitrogen (NO x ), are removed according to governmental and environmental regulations and standards.
[0011] The method is described below in reference to its application in connection with and operation of a system for continuously removing mercury from a supply of combustion gas generated during a combustion process. However, it will be obvious to those skilled in the art and guided by the teachings herein provided that the methods and systems described herein are likewise applicable to any combustion device including, without limitation, boilers and heaters, and may be applied to systems consuming fuels such as coal, oil or any solid, liquid or gaseous fuel.
[0012] As used herein, references to “particulate matter” are to be understood to refer to particulate matter contained within the combustion gas. The particulate matter includes particles of matter including, without limitation, fly ash and carbon, contained within the combustion gas as a naturally occurring product of a combustion process, and may also include externally-introduced matter including, without limitation, at least one of active carbon particles and additional fly ash, recirculated or injected into the particulate matter contained within the combustion gas.
[0013] FIG. 1 is a schematic view of an exemplary power plant system 100 according to one embodiment of the present invention. In the exemplary embodiment, system 100 includes a fuel storage device 12 such as but not limited to a bin, bunker, pile or silo in which a fuel supply is stored and collected prior to transport for combustion. The fuel storage device 12 is coupled in flow communication with a fuel transport device 14 which includes but is not limited to a feeder and piping arrangement used to transport fuel for combustion. A first injection port 16 extends into fuel transport device 14 and provides flow communication to fuel transport device 14 . In an alternative embodiment, first injection port 16 is positioned upstream of fuel storage device 12 . In the exemplary embodiment, system 100 includes a furnace combustion device 18 that combusts a plurality of fuels, such as but not limited to coal, oil, or any solid, liquid or gaseous fuels in which a supply of combustion gases is produced. Combustion device 18 includes a combustion zone 20 wherein a fuel-air mixture is combusted causing a stream of high temperature combustion gas 24 to be generated.
[0014] Fuel transport device 14 is coupled to combustion device 18 and is in flow communication therewith. Contained within combustion device 18 is a fuel combustion zone 20 . In the exemplary embodiment, an air injection port 22 extends into combustion device 18 and channels and is in flow communication with combustion zone 20 . In an alternative embodiment, a second injection port extends into combustion device 18 and is in flow communication with combustion zone 20 . In an alternative embodiment, a third injection port extends into combustion device 18 downstream of combustion zone 20 and is in flow communication with a high temperature combustion gas 24 . Combustion device 18 is coupled to a gas outlet duct 26 that is configured to direct a combustion exhaust gas 28 from combustion device 18 . In the exemplary embodiment, a first injection port 16 extends into fuel transport device 14 and is configured to inject a flow of mercury oxidizer to the combustible materials directed through fuel transport device 14 . First injection port 16 is formed as an injection tree, injection ring header or any other injection device configured to inject a flow of mercury oxidizer.
[0015] In an alternative embodiment, the first injection port is positioned upstream of fuel storage device 12 to provide mercury oxidizer flow to the combustible materials directed to fuel storage device 12 . In the exemplary embodiment, the first mercury oxidizer is injected on the combustible materials in the fuel transport device. Fuel transport device 14 provides a flow of combustible materials including the first mercury oxidizer to combustion device 18 .
[0016] In the exemplary embodiment, combustion device 18 is configured to combust a plurality of fuels, such as but not limited to coal, oil, or any solid, liquid or gaseous fuels in which a supply of combustion gases are produced. Combustion device 18 is configured with a combustion zone 20 wherein a fuel-air mixture is combusted causing a stream of high temperature combustion gas 24 to be generated. In an alternative embodiment, combustion device 18 is configured with but not limited to, additional combustion gas emission reducing equipment such as over fire air injection ports and gas reburn systems that have a temperature in excess of 2500 degrees Fahrenheit. In the exemplary embodiment, air injection port 22 extends into combustion device 18 to provide combustion air flow to combustion zone 20 . In an alternative embodiment, a second injection port is configured with combustion device 18 to provide a mercury oxidizer flow to combustion zone 20 . In an alternative embodiment, a third injection port is configured with combustion device 18 downstream of combustion zone 20 to provide mercury oxidizer flow to high temperature combustion gas 24
[0017] More specifically, combustion exhaust gases 28 are contained in gas outlet duct 26 , or other suitable connection, which directs combustion exhaust gas 28 through system 100 . Gas outlet duct 26 generally provides flow communication between components of system 100 through a passage in which combustion exhaust gas 28 is channeled. It is apparent to those skilled in the art and guided by the teachings herein provided that gas outlet duct 26 may have any suitable size, shape and/or diameter to accommodate any supply of combustion gas produced during the described combustion process.
[0018] In the exemplary embodiment, gas outlet duct 26 is coupled to a pollution control device 32 and is in flow communication therewith. Pollution control device 32 is coupled to exit duct 34 and is in flow communication therewith. Exit duct 34 is coupled to chimney 36 and is in flow communication to chimney 36 . Exit gases are released into the atmosphere through chimney 36 .
[0019] In operation, a stream of high temperature combustion gas 24 is generated and directed to flow through gas outlet duct 26 . Combustion gas 24 is discharged as combustion exhaust gas 28 . Combustion exhaust gas 28 is directed to pollution control device 32 . It is apparent to those skilled in the art and guided by the teachings herein provided that pollution control device 32 may have any suitable size, shape and/or diameter to accommodate any supply of combustion exhaust gas 28 produced during the described combustion process. Pollution control device 32 includes for example, but is not limited to a selective catalyst reduction device, an electrostatic precipitator, a baghouse, an activated carbon injection device, a flue gas desulfurization device, and/or any other mercury emission, nitrogen oxide emission and particulate emission control system technologies. Pollution control device 32 discharges into and provides a flow stream to exit duct 34 which directs a flow stream to chimney 36 . Exit gases are released into the atmosphere through chimney 36 .
[0020] In operation, system 100 facilitates continuously removing and reducing hazardous and/or toxic compounds, such as mercury emissions from the high temperature combustion gas stream produced during combustion within combustion device 18 .
[0021] In one exemplary embodiment, a method of injecting a mercury oxidizer upstream of combustion device 18 is presented. As used herein, a mercury oxidizer relates to an ion in solution or compound that combines with a mercury atom. In the exemplary embodiment, the mercury oxidizer includes MgCl 2 , which is stable up to 2600 degrees Fahrenheit. Specifically, in one embodiment, the mercury oxidizer includes at least one of a powder including MgCl 2 and an aqueous solution including MgCl 2 . MgCl 2 has a solubility in water of 54 g/100 ml and, therefore, an aqueous solution may contain up to 54% MgCl 2 . In another embodiment, the mercury oxidizer includes MgCl 2 along with air. The efficiency of mercury removal can be improved by adding MgCl 2 to the materials to be combusted. In an alternative embodiment, the efficiency of mercury removal can be improved by injecting MgCl 2 into the flue gas. In the exemplary embodiment, the solution is added in a ratio of approximately 0.5 pounds to approximately 3 pounds of MgCl 2 per approximately one ton of coal. Thermal decomposition of MgCl 2 produces Cl-containing species (HCl, Cl 2 , and Cl) which results in improved mercury oxidation and improves the efficiency of mercury removal. In an alternative embodiment, a method is provided of improving the efficiency of mercury removal by, for example, activated carbon injection, wet scrubbers and other mercury control technologies.
[0022] FIG. 2 is a schematic view of an exemplary power plant system 200 according to one embodiment of the present invention. System 200 components 12 , 14 , 18 , 20 , 24 , 26 , 28 , 32 , 34 and 36 are also illustrated in FIG. 1 .
[0023] In the exemplary embodiment, system 200 includes a fuel storage device 12 such as but not limited to a bin, bunker, pile or silo in which a fuel supply is stored and collected prior to transport for combustion. Fuel storage device 12 is coupled in flow communication with a fuel transport device 14 which includes but is not limited to a feeder and piping arrangement used to transport fuel for combustion. In an alternative embodiment, an injection port extends into fuel transport device 14 and provides flow communication to fuel transport device 14 . Fuel transport device 14 is coupled to combustion device 18 and provides flow communication to combustion device 18 . Contained within combustion device 18 is fuel combustion zone 20 . In the exemplary embodiment, a second injection port 23 extends into combustion device 18 and channels and is in flow communication with combustion zone 20 . In an alternative embodiment, a third injection port extends into combustion device 18 downstream of combustion zone 20 and channels and is in flow communication with high temperature combustion gas 24 .
[0024] In the exemplary embodiment, system 200 includes a furnace combustion device 18 that combusts a plurality of fuels, such as but not limited to coal, oil, or any solid, liquid or gaseous fuels in which a supply of combustion gases are produced. Combustion device 18 includes a combustion zone 20 wherein a fuel-air mixture is combusted causing a stream of high temperature combustion gas 24 to be generated. Combustion device 18 is coupled to gas outlet duct 26 that is configured to channel combustion exhaust gas 28 from combustion device 18 .
[0025] More specifically, combustion exhaust gases 28 are contained in gas outlet duct 26 , or other suitable connection, which directs combustion exhaust gas 28 through system 200 . Gas outlet duct 26 generally provides flow communication between components of system 200 through a passage in which combustion exhaust gas 28 is channeled. It is apparent to those skilled in the art and guided by the teachings herein provided that gas outlet duct 26 may have any suitable size, shape and/or diameter to accommodate any supply of combustion gas produced during the described combustion process.
[0026] In the exemplary embodiment, gas outlet duct 26 is coupled to a pollution control device 32 and is in flow communication therewith. Pollution control device 32 is coupled to exit duct 34 and is in flow communication therewith. Exit duct 34 is coupled to chimney 36 and is in flow communication with chimney 36 . Exit gases are released into the atmosphere through chimney 36 .
[0027] In operation, system 200 facilitates continuously removing and reducing hazardous and/or toxic compounds, such as mercury emissions from the stream of high temperature combustion gas 24 produced during combustion within combustion device 18 .
[0028] Fuel storage device 12 provides the combustible materials in flow communication with fuel transport device 14 which includes but is not limited to a feeder and piping arrangement used to transport fuel for combustion. In an alternative embodiment, a first injection port extends into fuel transport device 14 and is configured to inject a flow of mercury oxidizer to the combustible materials directed through fuel transport device 14 . In another embodiment, a first injection port is positioned upstream of fuel storage device 12 and provides mercury oxidizer to the combustible materials directed to fuel storage device 12 . Fuel transport device 14 provides a flow of combustible materials including the mercury oxidizer to combustion device 18 .
[0029] In the exemplary embodiment, combustion device 18 is configured to combust a plurality of fuels, such as but not limited to coal, oil, or any solid, liquid or gaseous fuels in which a supply of combustion gases are produced. Combustion device 18 is configured with a combustion zone 20 wherein a fuel-air mixture is combusted causing a stream of high temperature combustion gas 24 to be generated. In an alternative embodiment, combustion device 18 is configured with but not limited to, additional combustion gas emission reducing equipment such as over fire air injection ports and gas reburn systems.
[0030] In an alternative embodiment, an air injection port 22 (shown in FIG. 1 ) is coupled with combustion device 18 to provide combustion air flow to combustion zone 20 . In the exemplary embodiment, a second injection port 23 is coupled with combustion device 18 to provide a mercury oxidizer flow to combustion zone 20 . Second injection port 23 is formed as an injection tree, injection ring header or any other injection device configured to inject a flow of mercury oxidizer. In an alternative embodiment, a third injection port is coupled with combustion device 18 downstream of combustion zone 20 to provide mercury oxidizer flow to high temperature combustion gas 24 .
[0031] In one exemplary embodiment, a method is provided of injecting a mercury oxidizer on the materials to be combusted in combustion zone 20 of combustion device 18 . The mercury oxidizer, in one embodiment, is at least one of an ion in solution and a compound that combines with a mercury atom. In the exemplary embodiment, the mercury oxidizer includes MgCl 2 , which is stable up to 2600 degrees Fahrenheit. Specifically, in one embodiment, the mercury oxidizer includes at least one of a powder including MgCl 2 and an aqueous solution including MgCl 2 . MgCl 2 has a solubility in water of 54 g/100 ml and, therefore, an aqueous solution may contain up to 54% MgCl 2 . In another embodiment, the mercury oxidizer includes MgCl 2 along with air. The efficiency of mercury removal can be improved by injecting MgCl 2 to the materials to be combusted in combustion zone 20 . In an alternative embodiment, the efficiency of mercury removal can be improved by injecting MgCl 2 into the flue gas downstream of combustion zone 20 . In another alternative embodiment, the efficiency of mercury removal can be improved by injecting MgCl 2 into the materials to be combusted upstream of combustion device 18 . In the exemplary embodiment, the solution is added in a ratio of approximately 0.5 pounds to approximately 3 pounds of MgCl 2 per approximately one ton of coal. Thermal decomposition of MgCl 2 produces Cl-containing species (HCl, Cl 2 , and Cl) which results in improved mercury oxidation and improves the efficiency of mercury removal. In an alternative embodiment, a method is provided of improving the efficiency of mercury removal by using activated carbon injection, wet scrubbers and other mercury control technologies.
[0032] In the exemplary embodiment, system 200 generates a stream of high temperature combustion gas 24 that is in flow communication with gas outlet duct 26 and is discharged as combustion exhaust gas 28 . Combustion exhaust gas 28 is in flow communication with pollution control device 32 . It is apparent to those skilled in the art and guided by the teachings herein provided that pollution control device 32 may have any suitable size, shape and/or diameter to accommodate any supply of combustion exhaust gas 28 produced during the described combustion process. Pollution control device 28 includes, for example, but is not limited to, a selective catalyst reduction device, an electrostatic precipitator, a baghouse, an activated carbon injection device, a flue gas desulfurization device, and/or any other mercury emission, nitrogen oxide emission and particulate emission control system technologies. Pollution control device 32 discharges flow to exit duct 34 which directs flow to chimney 36 . Exit gases are released into the atmosphere through chimney 36 .
[0033] FIG. 3 is a schematic view of an exemplary power plant system 300 according to one embodiment of the present invention. System 300 components 12 , 14 , 18 , 20 , 24 , 26 , 28 , 32 , 34 and 36 are also shown in FIGS. 1 and 2 . In the exemplary embodiment, system 300 includes a fuel storage device 12 such as but not limited to a bin, bunker, pile or silo in which a fuel supply is stored and collected prior to transport for combustion. Fuel storage device 12 is coupled in flow communication with a fuel transport device 14 which includes but is not limited to a feeder and piping arrangement used to transport fuel for combustion. In an alternative embodiment, the first injection port extends into fuel transport device 14 and is in flow communication therewith. Fuel transport device 14 is coupled to combustion device 18 and is in flow communication therewith. Contained within combustion device 18 is fuel combustion zone 20 . In an alternative embodiment, the second mercury oxidizer injection port extends into combustion device 18 and is in flow communication with combustion zone 20 . The third mercury oxidizer injection port 25 extends into combustion device 18 downstream of combustion zone 20 and is in flow communication with high temperature combustion gas 24 .
[0034] In the exemplary embodiment, system 300 includes a furnace combustion device 18 that combusts a plurality of fuels, such as but not limited to coal, oil, or any solid, liquid or gaseous fuels in which a supply of combustion gases is produced. Combustion device 18 includes a combustion zone 20 wherein a fuel-air mixture is combusted causing a stream of high temperature combustion gas 24 to be generated. Combustion device 18 is coupled to gas outlet duct 26 that is configured to channel combustion exhaust gas 28 from combustion device 18 .
[0035] More specifically, combustion exhaust gases 28 are contained in gas outlet duct 26 , or other suitable connection, which directs combustion exhaust gas 28 through system 300 . Gas outlet duct 26 generally provides flow communication between components of system 300 through a passage in which combustion exhaust gas 28 is channeled. It is apparent to those skilled in the art and guided by the teachings herein provided that gas outlet duct 26 may have any suitable size, shape and/or diameter to accommodate any supply of combustion gas produced during the described combustion process.
[0036] In the exemplary embodiment, gas outlet duct 26 is coupled to a pollution control device 32 and is in flow communication therewith. Pollution control device 32 is coupled to exit duct 34 and is in flow communication therewith. Exit duct 34 is coupled to chimney 36 and provides flow communication to chimney 36 . Exit gases are released into the atmosphere through chimney 36 .
[0037] In operation, system 300 facilitates continuously removing and reducing hazardous and/or toxic compounds, such as mercury emissions from the stream of high temperature combustion gas 24 produced during combustion within combustion device 18 . Fuel storage device 12 provides the combustible materials in flow communication with fuel transport device 14 which includes but is not limited to a feeder and piping arrangement used to transport fuel for combustion. In an alternative embodiment, a first injection port extends into fuel transport device 14 and is configured to inject a flow of mercury oxidizer into the combustible materials directed through fuel transport device 14 . In another alternative embodiment, a first injection port is positioned upstream of fuel storage device 12 to provide mercury oxidizer flow to the combustible materials directed to fuel storage device 12 . Fuel transport device 14 provides a flow of combustible materials including the first mercury oxidizer to combustion device 18 .
[0038] In the exemplary embodiment, combustion device 18 is configured to combust a plurality of fuels, such as but not limited to coal, oil, or any solid, liquid or gaseous fuels in which a supply of combustion gases is produced. Combustion device 18 is coupled with a combustion zone 20 wherein a fuel-air mixture is combusted causing a stream of high temperature combustion gas 24 to be generated. In an alternative embodiment, combustion device 18 is configured with but not limited to, additional combustion gas emission reducing equipment such as over fire air injection ports and gas reburn systems.
[0039] In an alternative embodiment, an air injection port is coupled with combustion device 18 to provide combustion air flow to combustion zone 20 . In another alternative embodiment, a second injection port is coupled with combustion device 18 to provide a mercury oxidizer flow to combustion zone 20 . In the exemplary embodiment, a third injection port 25 is coupled with combustion device 18 downstream of combustion zone 20 to provide mercury oxidizer flow to high temperature combustion gas 24 . The third injection port 25 is formed as an injection tree, injection ring header or any other injection device configured to inject a flow of mercury oxidizer. The mercury oxidizer includes, in one embodiment, at least one of an ion in solution and compound that combines with a mercury atom. In the exemplary embodiment, the mercury oxidizer includes MgCl 2 , which is stable up to 2600 degrees Fahrenheit. Specifically, in one embodiment, the mercury oxidizer includes at least one of a powder including MgCl 2 and an aqueous solution including MgCl 2 . MgCl 2 has a solubility in water of 54 g/100 ml and, therefore, an aqueous solution may contain up to 54% MgCl 2 . In another embodiment, the mercury oxidizer includes MgCl 2 along with air. The efficiency of mercury removal can be improved by injecting MgCl 2 into the flue gas downstream of the combustion zone 20 . In an alternative embodiment, the efficiency of mercury removal can be improved by injecting MgCl 2 to the materials to be combusted in combustion zone 20 . In another alternative embodiment, the efficiency of mercury removal can be improved by injecting MgCl 2 into the materials to be combusted upstream of combustion device 18 . In the exemplary embodiment, the solution is added in a ratio of approximately 0.5 pounds to approximately 3 pounds of MgCl 2 per approximately one ton of coal. Thermal decomposition of MgCl 2 produces Cl-containing species (HCl, Cl 2 , and Cl) which results in improved mercury oxidation and improves the efficiency of mercury removal. In an alternative embodiment, a method is provided of improving the efficiency of mercury removal by utilizing activated carbon injection, wet scrubbers and other mercury control technologies.
[0040] In the exemplary embodiment, system 300 includes a stream of high temperature combustion gas 24 that is generated and is in flow communication with gas outlet duct 26 and is discharged as combustion exhaust gas 28 . Combustion exhaust gas 28 is in flow communication with pollution control device 32 . It is apparent to those skilled in the art and guided by the teachings herein provided that pollution control device 32 may have any suitable size, shape and/or diameter to accommodate any supply of combustion exhaust gas 28 produced during the described combustion process. Pollution control device 28 includes, for example, at least one of a selective catalyst reduction device, an electrostatic precipitator, a baghouse, an activated carbon injection device, a flue gas desulfurization device, and/or any other mercury emission, nitrogen oxide emission and particulate emission control system technologies. Pollution control device 32 discharges flow to exit duct 34 . Exit duct 34 is in flow communication with chimney 36 . Exit gases are released into the atmosphere through chimney 36 .
[0041] Exemplary embodiments of a method and system for continuously removing mercury from a supply of combustion gas are described above in detail. The method and system are not limited to the specific embodiments described herein, but rather, steps of the method and/or components of the system may be utilized independently and separately from other steps and/or components described herein. Further, the described method steps and/or system components can also be defined in, or used in combination with, other methods and/or systems, and are not limited to practice with only the method and system as described herein.
[0042] While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims. | A method of reducing mercury emissions using a combustion device including at least a combustion zone. The method includes receiving a flow of fuel including mercury at the combustion device assembly; injecting a first mercury oxidizer flow including MgCl 2 on the fuel upstream of the combustion device assembly; and oxidizing the mercury using a mercury oxidizer flows and the combustion device assembly. | 1 |
FIELD OF THE INVENTION AND RELATED ART
This invention relates to an exposure method and a device manufacturing method for transferring, in an exposure apparatus, a pattern of an original such as a mask to a substrate such as a wafer with high precision.
In accordance with further miniaturization and further enlargement of the density of semiconductor devices due to increasing the degree of integration thereof, regarding the linewidth, a linewidth of 0.25 micron is now required for 256 MDRAM and a linewidth of 0.18 micron is required for 1 GDRAM. Thus, exposure apparatuses for transferring by exposure a pattern of an original such as a reticle or mask to a substrate such as a wafer should have higher and higher precision and better linewidth precision.
Referring to a general structure of a conventional exposure apparatus in conjunction with FIGS. 11A-11C, a light source 1 emits exposure light 2 which goes through an illumination system 3 to illuminate an original 4 on which a mask pattern 4a is formed. The exposure light passing through the original 4 has an intensity distribution (FIG. 11B) corresponding to the mask pattern 4a, such that the energy distribution (FIG. 11C) to be absorbed by a resist 5a on a substrate 5 such as a wafer corresponds to the mask pattern 4a. The resist 5a is then developed to provide a resist image and, subsequently, through a deposition process and an etching process, for example, a circuit pattern in one layer is defined. In this manner, the mask pattern 4a of the original 4 is transferred by exposure to the substrate 5.
As regards the exposure sequence, there is a global alignment method known. An example is disclosed in Japanese Laid-Open Patent Application No. 44429/1986 wherein, prior to exposure of a substrate such as a wafer, positions of alignment marks formed on the substrate are measured and, then, a statistical procedure is performed on the basis of deviations between mark design positions and mark measured positions to determine six parameters, that is, offset (X and Y directions) of the center position of the substrate, expansion/contraction (X and Y directions) of the substrate, rotational amount of the substrate, and perpendicularity of a substrate stage. Then, for exposure of each shot, the substrate stage which holds the substrate is moved in accordance with a designated alignment amount, moving the stage stepwise by a predetermined amount, so as to minimize the registration error between that shot and the original. The sequence of such stepwise motion and exposure is repeated until exposure of the whole substrate is completed. Here, in some cases, after determination of the six parameters on the basis of deviations between the mark design positions and mark measured positions in accordance with the statistical procedure and before execution of the exposure of a first shot, magnification correcting means is used to correct the amount of expansion/contraction (X and Y directions) of the substrate. For example, if the amount of substrate expansion/contraction (X and Y directions) is +5 ppm, a particular lens or lenses of a projection optical system may be shifted in a direction outside the surface, by which only the transfer magnification can be changed by +5 ppm without changing the aberration. After this, as shown in FIGS. 12A and 12B, the procedure of exposure of a shot and stepwise motion of the substrate stage for the next shot is repeated, whereby the exposure process is performed.
The magnification correcting means may be other than the one based on an optical system such as described. Japanese Laid-Open Patent Application, Laid-Open No. 211872/1997 shows a method wherein the size of an original such as a mask or the size of a substrate such as a wafer is directly changed. In relation to scan exposure, U.S. Pat. No. 5,604,779 shows a method wherein an original and a substrate are relatively shifted for magnification correction.
According to investigations made by the inventor, it has been found that, even if an original and a substrate are accurately positioned at their design positions before execution of an exposure of a certain shot, there may be the following problems. That is, during exposure of one shot, the substrate is thermally expanded due to absorption of exposure light. Such thermal expansion of the substrate causes two types of variations, as illustrated in FIGS. 13A-13D, that is, a translation p of the shot center O and an enlargement e about the shot center O. Of FIGS. 13A-13D, FIG. 13A shows by a solid line the size Wo of the shot before execution of exposure of that shot, and FIG. 13B shows the size W of the shot after the exposure. FIG. 13C. shows the translation p of the shot center, and the enlargement (change in magnification) e about the shot center. As a result of such thermal expansion of the substrate, as shown in FIG. 13D, there occurs a change in the absorbed exposure energy profile of a resist on the substrate (the relation between the position on the resist and the absorbed exposure energy), during the exposure period of one shot. This causes a slow down of an integrated absorbed exposure energy profile during the exposure period, and it deteriorates the linewidth precision.
In conventional exposure apparatuses such as described, before shot exposure, the magnification of a substrate is calculated on the basis of the result as attainable in accordance with the global alignment method. Then, an original or an optical system is shifted in a direction outside the surface or is deformed in a direction along the surface, by use of magnification correcting means, to change the size of the original or the optical system thereby to change the magnification so that it is fitted to the magnification of the substrate. Then, the shot exposure starts. However, since there is no measure with respect to thermal deformation of the substrate during exposure of one shot due to absorption of exposure light by the substrate, the transfer linewidth precision is degraded.
Further, as regards thermal distortion during scan exposure, the amount of movement of a mask pattern of an original, which is exposed simultaneously, varies with the position. It is, therefore, not possible to accomplish complete registration between the pattern of the original and the pattern of the substrate during the exposure, with respect to the whole of the pattern to be exposed simultaneously, merely by relatively moving the original and the substrate. Thus, the linewidth precision degrades, depending on the position.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an exposure method and/or an exposure apparatus by which degradation of linewidth precision due to thermal expansion of a substrate such as a wafer during exposure thereof can be reduced.
It is another object of the present invention to provide a device manufacturing method by which high precision devices can be produced with good efficiency.
Briefly, the present invention has been made on the basis of the finding that; thermal distortion during the exposure process mainly comprises enlargement about the center of a shot; the rate of enlargement is approximately uniform; and by correcting at least one of, preferably both of, translation of the shot center of the substrate and enlargement about the shot center during the exposure process, degradation of linewidth precision can be reduced.
In accordance with an aspect of the present invention, there is provided an exposure method, comprising the steps of: transferring, by exposure, a pattern formed on an original to different shot regions on a substrate sequentially; and performing, during exposure of a certain shot, at least one of (i) adjusting the relative positional relation between the original and the substrate, with respect to a direction effective to correct translation of a transfer region of the substrate due to thermal distortion thereof, and (ii) adjusting a transfer magnification of the pattern of the original to the substrate so as to correct enlargement of the transfer region due to thermal distortion of the substrate.
In accordance with another aspect of the present invention, there is provided a device manufacturing method, comprising the steps of: preparing a substrate; applying a resist to the substrate prior to exposure thereof; transferring, by exposure, a pattern of an original to the substrate in accordance with an exposure method as recited above; and developing the resist of the substrate after the exposure.
In accordance with a further aspect of the present invention, there is provided an exposure apparatus for transferring a pattern formed on an original to different shot regions of a substrate sequentially, said apparatus comprising: a first holding mechanism for holding the original; a second holding mechanism for holding the substrate; a moving mechanism for relatively and minutely moving the original and the substrate held by said first and second holding mechanisms, relative to each other; a magnification adjusting mechanism for providing variable transfer magnification in relation to transfer of the pattern of the original to the substrate; and control means for actuating said moving mechanism and said magnification adjusting mechanism during exposure of a shot.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic and diagrammatic view of an exposure apparatus, which best shows features of an exposure method according to the present invention.
FIG. 2 is a schematic and diagrammatic view, for explaining the structure related to a stage control system of an exposure apparatus to which an exposure method according to the present invention is applied.
FIG. 3 is a schematic and plan view of a chuck for an original, in the exposure apparatus.
FIGS. 4A and 4B are schematic views, respectively, showing a magnification correcting mechanism disposed on a bottom side of an original chuck base in the exposure apparatus, wherein FIG. 4B is a sectional view taken on line A--A in FIG. 4A.
FIG. 5 is a top plan view showing alignment patterns provided on an original and a substrate.
FIG. 6 is a schematic view for explaining the process of obtaining a correction table for correcting means of the present invention on the basis of experiments, and for explaining the state of deformation of a shot of a substrate and alignment patterns thereof due to the effect of thermal expansion during exposure of the shot.
FIG. 7 is a schematic view for explaining another example of the process for obtaining a correction table for correcting means on the basis of experiments, and for explaining a case wherein a dual-axis distortion gauge is disposed approximately at the center of each shot of the substrate.
FIG. 8 is a schematic and sectional view for explaining an example wherein a magnification correcting mechanism uses an optical element in accordance with an exposure method of the present invention.
FIG. 9 is a flow chart for explaining semiconductor device manufacturing processes.
FIG. 10 is a flow chart for explaining details of a wafer process.
FIGS. 11A-11C are schematic views, respectively, wherein FIG. 11A shows a general structure of a conventional exposure apparatus, FIG. 11B shows an intensity distribution of exposure light passed through an original, and FIG. 11C shows distribution of energies absorbed by a resist.
FIGS. 12A and 12B are schematic views, respectively, wherein FIG. 12A shows a general structure of a conventional exposure apparatus, and FIG. 12B shows an example of a step-and-repeat exposure process.
FIGS. 13A-13D are schematic views, respectively, for explaining thermal expansion of a substrate during exposure of a shot due to absorption of exposure light, wherein FIGS. 13A and 13B show the size of a shot before and just after the shot exposure, respectively, wherein FIG. 13C shows a translation p of the center O of the shot and an enlargement (magnification change) e about the shot center O, and wherein FIG. 13D shows changes in an absorbed exposure energy profile of a resist on the substrate during the exposure period (i.e., the relation between the position on the resist and the absorbed exposure energy).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
FIG. 1 is a schematic and diagrammatic view of an exposure apparatus which best shows features of an exposure method according to the present invention. Through exposure experiments or calculation, deformation which will be produced in a substrate 5 such as a wafer, for example, during exposure of one shot due to thermal expansion of the substrate is determined beforehand. On the basis of the thus determined data, a correction table for cancelling deformation of the substrate 5 is prepared, and a substrate stage 8 for holding the substrate 5 is moved in a direction along the surface thereof. Then, an external force is applied to an original 4 such as a mask, for example, to change the magnification of the original 4. Correction data for the magnification correction is stored in the correction table. Correcting means 13 has this correction table and, by using this correcting means 13, the stage 8 is moved in a direction along the surface by means of a stage controller 12 during the shot exposure, so that a translation of the shot center of the substrate 5 due to thermal expansion during the exposure is canceled. Also, a magnification correction controller 11 operates during the shot exposure to actuate a transfer magnification correcting mechanism 10 to apply an external force to the original 4, by which the magnification of the original 4 is changed and by which an enlargement of the substrate about the shot center is canceled.
The general structure of the present invention will be described with reference to FIGS. 1 and 2.
An original 4 such as a mask, for example, having a pattern formed thereon is fixedly held by an original chuck 6. Also, a substrate 5 such as a wafer, for example, is held by a substrate chuck 7 by attraction. The substrate chuck 7 is mounted on a substrate stage 8 which is movable in X and Y directions. Exposure light 2 emitted from a light source comprises X-rays, ultraviolet rays or visible light, and it passes through an illumination system 3 and illuminates the original 4. By this, the pattern formed on the original 4 is transferred, by exposure, onto the substrate 5. The magnification correcting mechanism 10 for correcting magnification of the original 4 by applying an external force to the original 4 is actuated in response to an output signal from the magnification correction controller 11. The substrate stage 8 for moving the substrate 5 to a desired position is actuated in response to an output signal of a stage controller 12. The position, movement speed and acceleration of the substrate 5 are controlled by means of the stage controller 12. The magnification correction controller 11 and stage controller 12 are arranged to actuate the magnification correcting mechanism 11 and the substrate stage 8 during exposure of one shot, in accordance with a specified value based on the correction table of the correcting means 13. Details of the correction table of the correcting means will be described later.
Referring to the stage controller 12, in conventional exposure apparatuses wherein exposure light 2 is projected over the whole exposure picture angle by an illumination system 3 to execute simultaneous exposure thereof, such as disclosed in Japanese Laid-Open Patent Application, Laid-Open No. 100311/1990, during exposure of one shot, a stage controller 12 so controls that, relative to an original 4 held fixed on an original chuck 6, a substrate chuck 7 is held stationary at a fixed position with respect to a certain reference. For this reason, a laser interferometer 14 is used to measure the position of the substrate chuck 7 with respect to the reference, and positioning thereof is performed. After completion of exposure of one shot, the stage controller 12 moves the substrate stage 8 stepwise in accordance with a global alignment specified value as produced by a global alignment unit 16, and the subsequent shot is exposed in a similar manner. Thus, with the conventional stage controller 12, during exposure of one shot, the substrate chuck 7 is kept stationary relative to the fixed original 4, at a certain position with respect to the reference.
As compared therewith, the stage controller 12 of the present invention controls so that, during exposure of one shot and relative to the original 4 held fixed, the distance of the substrate chuck 7 with respect to a reference is changed in accordance with the correction table of the correcting means 13. For example, it operates to move the chuck so that a translation p of the shot center O of the substrate 5 (FIG. 13C) is canceled. With such movement, the amount of translation of the shot center O of the substrate, in the X and Y directions, produced by thermal expansion of the substrate 5 during exposure of one shot, can be reduced approximately to zero.
Next, details of the structure of the original chuck 6 will be described, with reference to FIG. 3.
Original frame 21 holds an original 4 having a pattern formed on its membrane. Positioning the original frame 21 with respect to X and Y directions is performed by supporting means 19 which is mounted on one side of an original chuck base 30 and pressing means 20 which includes a pressing member 29 such as an air cylinder, for example. Positioning of the frame with respect to the Z direction is performed by Z clamping means (40a, 40b and 40c). The supporting means 19 includes an X-direction supporting member 19a which is mounted on the original chuck base 30 by a single bolt 22, for fine motion about the Z axis, and which supports supporting pins 25a and 25b of hemispherical rigid balls for engaging with a side edge of the original frame 21 for positioning the same with respect to the X direction. The supporting means 19 further includes a Y-direction supporting member 19b which is fixedly mounted on the original chuck base 30 by two bolts 22 and which supports supporting pins 25c and 25d for engaging with another side edge of the original frame 21 for positioning the same with respect to the Y direction. On the other hand, pressing means 20 includes an X-direction pressing member 20a which can be driven by a pressurizing member 29a such as an air cylinder, for example, mounted on the original chuck base 30, and which supports hemispherical pressing pins 26a and 26b for pressing a side edge of the original frame 21 in the X direction. The pressing means 20 further includes a Y-direction pressing member 20b which can be similarly driven by a pressurizing member 29b such as an air cylinder mounted on the original chuck base 30 and which supports hemispherical pressing pins 26c and 26d for pressing a side edge of the original frame 21 in the Y direction. The pressing pins 26a and 26b of the X-direction pressing member 20a are disposed at positions which are opposed to the supporting pins 25a and 25b of the supporting member 19a with the original frame 21 interposed therebetween. The pressing pins 26c and 26d of the Y-direction pressing member 20b are disposed at positions which are opposed to the supporting pins 25c and 25d of the supporting member 19b with the original frame 21 interposed therebetween. With this structure, a pressing force can be applied toward the supporting pins 25a and 25b by the pressurizing member 29a and through the pressing pins 26a and 26b of the pressing member 20a, by which the original frame 21 can be positioned with respect to the X direction. Similarly, a pressing force can be applied toward the supporting pins 25c and 25d by the pressurizing member 29b and through the pressing pins 26c and 26d of the pressing member 20b, by which the original frame 21 can be positioned with respect to the Y direction.
When the positioning of an original is accomplished by pressing the side edges of the original frame 21 through the pressing pins 26a-26d, and if any imbalance between driving forces of the pressing members 20a and 20b produces a rotational moment in the original 4, the X-direction supporting member 19a can be rotationally moved by a small amount about the Z axis. This effectively reduces distortion of the original due to over-confinement by the four supporting pins 25a-25d.
In the manner described above, positioning of the original with respect to the X and Y directions and about the Z axis is accomplished by use of the supporting means 19, including supporting members 19a and 19b with supporting pins 25a-25d, and the pressing means 20, including pressing members 20a and 20b with pressing pins 26a-26d.
Z clamping means (40a, 40b and 40c) for accomplishing positioning with respect to the Z direction, comprises three clamping mechanisms 40a, 40b and 40c which can be driven by means of actuators (not shown) having rotational motion and straight motion mechanisms. The Z clamping means further comprises three hemispherical rigid ball members (not shown) which are disposed at positions opposed to the clamping mechanisms 40a, 40b and 40c, respectively, to sandwich the original frame 21 therebetween for positioning of the original 4. The Z clamping means should be disposed at a position not interfering with the supporting means and the pressing means for X-direction and Y-direction positioning or with a magnification correcting mechanism to be described later. The original frame 21 is positioned with respect to the Z direction as the same is pressed by the Z clamping means toward the original chuck base 30. Simultaneously therewith, the positioning thereof about the X and Y axes is performed. Since the Z-direction positioning is accomplished at three points by the Z clamping means as described above, an original can be held without flatness correction which may cause deformation along the surface. Also, the structure effectively reduces the possibility of deformation of an original due to any foreign particle caught between the original and the original chuck.
An example of a specific structure of magnification correcting mechanism 10 will now be described with reference to FIGS. 4A and 4B. Mounted on the bottom face of the original chuck base 30 are a pair of magnification correcting members 33a and 33c which are disposed opposed to each other in the X direction. Also, there are a pair of magnification correcting members 33b and 33d which are disposed opposed to each other in the Y direction. These magnification correcting members 33a-33d have the same mechanism, and only the magnification correcting member 33a disposed in the X direction will be explained. The magnification correcting member 33a includes a correcting pin 36a and an air cylinder 34a. The correcting pin 36a is inserted into throughbores 35a and 37a which are formed in the original chuck base 30 and the original frame 21, being attached to one side of the original chuck base 30, respectively, and which are registered with each other. The air cylinder 34a operates to drive the correcting pin 36a, through a rod, to move the same forwardly or backwardly along the X direction. The air cylinder 34a is mounted on the bottom face of the original chuck base 30, and its pressure is controlled in accordance with a specified value in the correction table of the correcting means 13 and the magnification correction controller 11. The throughbore 35a of the original frame 21 is formed with a size smaller than that of the throughbore 37a of the original chuck base 30. With this structure, by changing the pressure of the air cylinder 34a, the correction pin 36a is moved through the rod in the X direction within the throughbore 37a, such that the side face of the correcting pin 36a pushes or pulls the inside face of the throughbore 35a of the original frame 21 in the X direction. Thus, by controlling the pressure of the air cylinder 34a of the magnification correcting member 33a, a compressing force or a tension force can be applied to the original 4 independently in the X direction, through the correcting pin 36a. The remaining magnification correcting members 33b, 33c and 33d have similar structures. Thus, by controlling pressures of air cylinders 34a-34d in accordance with specified values of the correction table of the correcting means 13 and the magnification correction controller 11, a compressing force or a tension force can be applied to the original in the X and Y directions, independently, thereby to change the magnification of the original 4 so that it is suited to the magnification of the substrate. As described, the magnification correcting mechanism 10 of the present invention is operable to change the transfer magnification during exposure of one shot, in accordance with a specified value of the correction table of the correcting means 13 and the magnification correction controller 11. For example, during exposure of a shot, the substrate may be enlarged about the shot center O (FIG. 13C) due to thermal expansion. On that occasion, the magnification correction may be controlled as described above, by which changes of magnification, in X and Y directions, about the shot center O of the substrate produced by thermal expansion of the substrate can be reduced approximately to zero.
As regards magnification correction for an original such as a mask, while magnification correction based on thermal means is known, response of the magnification correction using thermal means is not good and a long time is necessary for the magnification correction. This leads to a reduction of throughput and to decreased productivity. In consideration of this, the present embodiment uses mechanical means such as described above.
Next, the correction table of the correcting means 13 will be described. FIG. 5 shows alignment patterns formed on an original and a substrate, which are used for obtaining a correction table through experiments. There are longitudinal (Y-direction) positional deviation measuring marks MU and MD at upper and lower portions of the exposure picture angle, and lateral (X-direction) positional deviation measuring marks ML and MR at left-hand and right-hand portions. For detection of the amount of positional deviation between alignment patterns of the original and the substrate, a method based on heterodyne interference, a method based on Fresnel zone plate diffraction light, or a method based on image processing, may be used.
Then, an original having substantially the same opening ratio as a printing original to be used for practical device manufacture is used. Before a start of exposure, the alignment patterns of the original and a substrate are brought into alignment with each other and, subsequently, exposures of shots of the substrate are made. Positional deviations of alignment patterns to be produced during the exposure are calculated as follows.
FIG. 6 is an illustration for explaining the manner of obtaining a correction table of the correcting means by use of the alignment patterns shown in FIG. 5 and through experiments. An original and a substrate have alignment patterns MU, MD, ML and MR formed at corresponding positions. The size of a shot of the substrate before exposure of the shot as well as alignment patterns therefor are depicted by broken lines. The shot and alignment patterns as deformed by thermal expansion during exposure of the shot are depicted by solid lines. A design length between the X-direction marks ML and MR is Lx, and a design length between Y-direction marks MU and MD is Ly. What are to be detected here are shot translation direction offset (X, Y) of each shot, X-direction magnification Mx and Y-direction magnification My. It is now assumed that, based on measurement of alignment signals during the exposure, the X-direction movement amounts of the marks ML and MR are Δx1 and Δx2, respectively, while the Y-direction movement amounts of the marks MU and MD are Δy1 and Δy2, respectively. Then, the following signal processing is performed to calculate these values.
X translational direction offset: X=(Δx1+Δx2)/2
Y translational direction offset Y=(Δy1+Δy2)/2
X direction magnification: Mx=(Lx+Δx1-Δx2)/Lx
Y direction magnification: My=(Ly+Δy1-Δy1)/Ly
In a case where, from the symmetry of the pattern disposition of the original, the X-direction magnification My Mx and the Y-direction magnification may be considered to be substantially the same, the shot translational direction offset (X, Y) and X-Y magnification Mxy may be determined as follows. When it is detected from alignment signals that the mark ML has moved in the X direction by Δx1 and the mark MR has moved in the X direction by Δx2 and that the mark MU has moved in the Y direction by Δy1, like the preceding example, it can be calculated from below:
X translational direction offset: X=(Δx1+Δx2)/2
X-Y magnification: Mxy=(Lx+Δx1-Δx2)/Lx
Y translational direction offset:
Y=Δy1-(Lx×Mxy-Lx)/2
A larger number of marks may be used to remove the rotational component.
FIG. 7 shows a measurement pattern provided on a substrate, for detecting X-direction magnification Mx and Y-direction magnification My for the correction table of correcting means, beforehand, on the basis of another type of experiments. More specifically, a dual-axis distortion gauge SG with respect to the X and Y directions is defined substantially at the center of each shot of the substrate. The distortion gauge SG may be attached to the substrate surface, or it may be formed on the substrate through a thin film forming process. Alternatively, it may be attached to the substrate chuck. An original having substantially the same opening ratio as a printing original to be used for practical device manufacture is used, and exposures of shots on the substrate are performed. During exposure of each shot, values of distortion gauges SG provided in relation to these shots of the substrate are measured and, on the basis of this, X-direction distortion=X-direction magnification Mx, and Y-direction distortion=Y-direction magnification My can be calculated. Also, in a case where, from the symmetry of the pattern disposition on the substrate, the X-direction magnification Mx and the Y-direction magnification My can be regarded as being substantially the same, an X-Y single axis distortion gauge may be provided at the center of each shot and, by measuring values of distortion gauges being measured during exposures, distortion=X-Y magnification, that is, Mxy, may be detected.
Second Embodiment
In some exposure apparatuses using visible light or ultraviolet light such as an i-line exposure apparatus or a KrF excimer exposure apparatus wherein an original such as a mask has a high rigidity so that correcting the magnification by mechanically deforming the original is difficult to achieve, an optical element inside a projection optical system may be used for correction of transfer magnification. Before a start of exposure of a shot, the magnification of the substrate is calculated from the result having been obtained in accordance with a global alignment method, and, by moving the optical element in a direction outside the surface, the magnification is changed to meet the magnification of the substrate. Thereafter, exposure of the shot starts. Such optical element may be one by which, with movement thereof in a direction outside the surface, only the transfer magnification can be changed without changing the aberration.
Such an optical element of a projection optical system having the characteristic such as described above is used in this embodiment. Like the preceding embodiment, deformation due to thermal expansion of a substrate such as a wafer during exposure of one shot is calculated on the basis of exposure experiments or simulations. On the basis of the data thus obtained, the substrate stage for holding the substrate is moved in a direction along the surface to cancel the deformation of the substrate. Then, the optical element is moved in a direction outside the surface to change the transfer magnification. Correcting means having a correction table in which data for this is stored, is used to move, through a stage controller, the substrate stage in a direction along the surface during the exposure of the shot, by which translation of the shot center of the substrate due to thermal expansion by exposure is canceled. Also, during exposure of the shot, the optical element is moved in a direction outside the surface to change the magnification, by which enlargement of the substrate about the shot center is canceled.
FIG. 8 shows an example of a specific structure. Denoted in the drawing at 39 is a light source, and denoted at 40 is a mask. Denoted at 41 is a substrate, and denoted at 48 is a substrate stage. A projection optical system for projecting a pattern of the mask 40 to the substrate 41 includes an optical element 42 which is mechanically joined to a cell 43 by fitting, for example, and the cell 43 is mounted on a guide 11, such that movement of the optical element 42 and the cell 43 in a direction along the surface is confined while movement of them in a direction outside the surface is allowed. The cell 43 can be urged outwardly from the surface by means of a piezoelectric device 45, attached to the cell 43, by which also the optical element 43 is urged outwardly from the surface, such that the exposure magnification is changed. During exposure of one shot, the transfer magnification of the optical element 42 is changed in accordance with the correction table of the correcting means 13 having been prepared beforehand, and, in addition thereto, the substrate stage 48 is moved. With this operation, like the preceding embodiment, magnification changes in X and Y directions around the shot center of the substrate, caused by thermal expansion of the substrate during exposure of one shot, can be reduced substantially to zero.
In accordance with the arrangement of the present invention as described hereinbefore, translation of the center of a shot of a substrate as well as enlargement about the shot center caused by thermal expansion during exposure of one shot can be corrected by relatively moving the original and the substrate and by actuating a transfer magnification correcting mechanism. Degradation of linewidth precision is thus reduced.
Also, even for an i-line exposure apparatus or a KrF excimer exposure apparatus wherein, due to high rigidity of an original, magnification correction by mechanically deforming the original is difficult to accomplish, an optical element (magnification element) may be used to correct translation of the shot center of a substrate as well as enlargement thereof about the shot center. This effectively reduces degradation of linewidth precision.
Third Embodiment
Next, an embodiment of a device manufacturing method which uses an exposure method such as described hereinbefore, will be explained.
FIG. 9 is a flow chart of a procedure for the manufacture of microdevices such as semiconductor chips (e.g., ICs or LSIs), liquid crystal panels, CCDs, thin film magnetic heads or micro-machines, for example. Step 1 is a design process for designing a circuit of a semiconductor device. Step 2 is a process for making a mask on the basis of the circuit pattern design. Step 3 is a process for preparing a wafer by using a material such as silicon. Step 4 is a wafer process which is called a pre-process wherein, by using the so prepared mask and wafer, circuits are practically formed on the wafer through lithography. Step 5 subsequent to this is an assembling step which is called a post-process wherein the wafer having been processed by step 4 is formed into semiconductor chips. This step includes an assembling (dicing and bonding) process and a packaging (chip sealing) process. Step 6 is an inspection step wherein an operation check, a durability check and so on for the semiconductor devices provided by step 5, are carried out. With these processes, semiconductor devices are completed and they are shipped (step 7).
FIG. 10 is a flow chart showing details of the wafer process. Step 11 is an oxidation process for oxidizing the surface of a wafer. Step 12 is a CVD process for forming an insulating film on the wafer surface. Step 13 is an electrode forming process for forming electrodes upon the wafer by vapor deposition. Step 14 is an ion implanting process for implanting ions to the wafer. Step 15 is a resist process for applying a resist (photosensitive material) to the wafer. Step 16 is an exposure process for printing, by exposure, the circuit pattern of the mask on the wafer through the exposure apparatus described above. Step 17 is a developing process for developing the exposed wafer. Step 18 is an etching process for removing portions other than the developed resist image. Step 19 is a resist separation process for separating the resist material remaining on the wafer after being subjected to the etching process. By repeating these processes, circuit patterns are superposedly formed on the wafer.
With these processes, high density microdevices can be manufactured with lower cost.
While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims. | An exposure method includes the steps of transferring, by exposure, a pattern formed on an original to different shot regions on a substrate sequentially, and performing, during exposure of a certain shot, at least one of (i) adjusting a relative positional relation between the original and the substrate, with respect to a direction effective to correct translation of a transfer region of the substrate due to thermal distortion thereof, and (ii) adjusting a transfer magnification of the pattern of the original to the substrate so as to correct enlargement of the transfer region due to thermal distortion of the substrate. In one preferred form, the adjustment is made in accordance with a correction table related to thermal expansion of the substrate during exposure and being prepared on the basis of one of a calculation and a preparatory exposure experiment. In another preferred form, the transfer magnification is adjusted by deforming the original, and in a further preferred form, the transfer magnification is adjusted by adjusting a projection optical system for projecting the pattern of the original to the substrate. | 6 |
CROSS REFERENCES TO RELATED APPLICATIONS
This application is the U.S. National Stage of International Application No. PCT/JP02/04351, filed May 1, 2002.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a simplified analyzer.
2. Description of the Related Art
In general, there have been broadly used an analytical test papers made by impregnating water absorbing paper with color reaction reagent for making a water quality analysis or the like. In order to analyze water quality by using a conventional simplified analyzer using the analytical test paper, the analysis of the water quality is carried out by soaking the analyzer in testing fluid to be analyzed, to react the testing fluid with the color reaction reagent and comparing the color of the testing fluid. The color of the testing fluid changes as the result of the reaction with the color reaction reagent and a standard color is prescribed as a reference color.
However, the conventional analyzer using the analytical test paper has a disadvantage in which it is inferior in sensitivity and accuracy of water quality analysis because the color reaction reagent may elute into the testing fluid when soaking the test paper in the testing fluid.
Correspondingly, there is known a simplified analyzer provided for improving the analyzing sensitivity as illustrated in FIG. 10 . The conventional simplified analyzer 9 shown in FIG. 10 has a transparent or semitransparent hermetic container 90 containing powdered color reaction reagent 91 . The hermetic container 90 may be made of a polyethylene tube having both ends sealed by thermal welding or ultrasonic welding or in another method.
In conducting a water quality analysis by use of the simplified analyzer, shown in FIGS. 10 and 11 , it is necessary to thrust a pin 92 , separately prepared, into the hermetic container 90 to make a small through hole 93 in the hermetic container 90 . Then, as shown in FIG. 12 , the air or gas 21 in the hermetic container 90 is let out of the container through the hole 93 by forcibly pinching the container 90 with fingers 20 . Thereafter, the hermetic container 90 is soaked in the testing fluid 22 to allow the testing fluid 22 to flow into the hermetic container 90 like a dropper as shown in FIG. 13 . Consequently, the color reaction reagent 91 and the testing fluid 22 are mixed inside the hermetic container 90 to cause the color reaction. After the lapse of predetermined time, the water quality analysis is concluded by comparing the color changed as the result of the color reaction, with a standard color to measure the concentration of the testing fluid.
The simplified analyzer described above has an advantage in that the color reaction reagent and the testing fluid to be analyzed can be increased in amount in comparison with the conventional analyzer using analytical test paper. Thus, this simplified analyzer makes it possible to analyze even dilute testing fluid and can prevent the color reaction reagent from eluting into the testing fluid, consequently to conduct the required water quality analysis with high accuracy.
Since the aforementioned simplified analyzer requires the pin for piercing the hermetic container to conduct the water quality analysis, it can be said that this conventional simplified analyzer aiming at the simplicity of the structure is incomplete without such an additional component, and therefore, it is desired to be further improved. Besides, since the hermetic container is manually pierced with the pin, some inexperienced workers may possibly pierce an awkward hole in the hermetic container, as the result of which it is possibly difficult to apply suction to the testing fluid sucked into a small hermetic container or deal with a relatively small amount of testing fluid.
The present invention is made in the light of the foregoing disadvantages of the conventional analyzer and seeks to provide a novel simplified analyzer capable of being handled easily and surely without using any other tool such as a pin and a method for producing the simplified analyzer.
BRIEF SUMMARY OF THE INVENTION
To attain the object described above according to the present invention, there is provided a simplified analyzer comprising a see-through hermetic container containing a reaction reagent, and a tap member piercing detachably through the aforesaid hermetic container.
When the analyzer is used, the tap member is removed from the hermetic container to let out the air of the container and suck test material to be analyzed into the container.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an explanatory diagram showing an embodiment of a simplified analyzer according to the present invention.
FIG. 2 is a cross sectional view taken along line A-A in FIG. 1 .
FIG. 3 is a cross sectional view taken along line B-B in FIG. 2 .
FIG. 4 is an explanatory diagram illustrative of the procedure for using the simplified analyzer according to the present invention.
FIG. 5 is an explanatory diagram illustrative of the procedure for using the simplified analyzer according to the present invention.
FIG. 6 is an explanatory diagram illustrative of the procedure for using the simplified analyzer according to the present invention.
FIG. 7 is an enlarged view showing a tap member used in the analyzer.
FIG. 8 is a view showing the simplified analyzer in its wrapped state according to the present invention.
FIG. 9 is a view showing the simplified analyzer in its wrapped state according to the present invention.
FIG. 10 is a view showing a conventional simplified analyzer.
FIG. 11 is a diagram illustrative of the procedure for using the conventional simplified analyzer.
FIG. 12 is a diagram illustrative of the procedure for using the conventional simplified analyzer.
FIG. 13 is a diagram illustrative of the procedure for using the conventional simplified analyzer.
DETAILED DESCRIPTION OF THE INVENTION
The simplified analyzer according to the present invention is characterized by a see-through hermetic container containing a reaction reagent, and a tap member piercing detachably through the aforesaid hermetic container.
According to this structure of the analyzer of the invention, only by removing the tap member from the hermetic container with fingers, the air is let out of the container, and alternatively, test material to be analyzed can be introduced into the container. The term “see-through” used herein for the hermetic container means that the container is wholly made transparent or semitransparent or a part of the container is made transparent or semitransparent, so that the content in the container can be visually checked.
Further, the simplified analyzer of the present invention is characterized by making the hermetic container of flexible plastic material.
With this structure, the hermetic container can be deformed by being depressed with a finger to let out the air of the container and suck testing fluid to be analyzed into the container.
The simplified analyzer of the invention has another feature that the hermetic container has seam portions formed by sealing the both end parts thereof by welding, and the tap member is embedded in one of the seam portions.
Consequently, the area of contact between the hermetic container and the tap member embedded in the hermetic container becomes wide to increase resistance to a force for pulling out the tap, consequently to prevent the tap member from falling off accidentally. As a result, the sealing performance of the hermetic container is elevated to prevent the reaction reagent and testing fluid from leaking.
The aforementioned simplified analyzer according to the invention has still another characteristic in that the tap member may be formed of a string or rod material.
This characteristic structure enables the tap member to be optimized in shape.
The present invention has a further characteristic in that the tap member is provided on its one end with a finger hook having a larger diameter than the other part.
Thus, the tap member can easily be removed from the container by hooking a finger through the finger hook and pulling. When the tap member once pulled out is inserted into the container, the finger hook is caught on a through hole formed in the seam portion of the container to prevent the tap member from being entirely inserted in the container by accident.
The aforementioned simplified analyzer according to the invention has a further feature in that the other tip end of the tap member is formed in an acuminate shape.
With the tap member having the acuminate tip end, even when the tap member is pulled out, it can easily be inserted in the seam portion of the container once again. The acuminate shape of the tap member may be formed by cutting the tip end of the tap member slantwise or tapering the tap member toward the tip end.
The aforementioned simplified analyzer according to the invention has a further feature in that one tip end of the tap member protrudes outward over the other tip end as viewed in the longitudinal direction.
The protrusion at one of the tip ends of the tap member brings about resistance to a force for pulling up the tap member so as to prevent the tap member from coming off accidentally.
The present invention has a further characteristic in that the hermetic container and the tap member in the simplified analyzer of the invention are formed in different colors.
By forming the hermetic container and the tap member in the simplified analyzer of the invention in different colors, the tap member can readily be discerned when being drawn out from the hermetic container, thus to facilitate the required analytical work.
The present invention has a further characteristic in that one or more of the simplified analyzers according to the invention may be packed as one unit in a moisture-proof wrapping.
The reaction reagent contained in the hermetic container of the simplified analyzer packed in the moisture-proof wrapping can be completely protected without being affected by moisture in the air or the like.
Another object of the present invention is to provide a method for producing the aforementioned simplified analyzer having a characteristic in that the hermetic container can readily be produced by preheating the edge portion of the container and thermally sealing the preheated edge portion by welding while keeping the tap member in the edge portion.
According to this method, the hermetic container can securely be sealed by welding without adhering to the tap member, so that the tap member can easily be pulled out.
One embodiment of the present invention will be described in detail hereinafter.
FIGS. 1 to 9 illustrate an embodiment of the simplified analyzer according to the present invention along with the processes of using the analyzer. In the illustrated embodiment, a color reaction reagent is used as a chemical agent for use in a reaction. Just as one example, the simplified analyzer described herein is applied for analyzing water quality.
The simplified analyzer 1 generally comprises the transparent or semitransparent hermetic container 10 containing the color reaction reagent 11 and the tap member 12 partially inserted in the hermetic container 10 . The tap member 12 can be pulled out from the hermetic container 10 with a finger 20 , consequently to form a through hole 13 in the hermetic container.
The hermetic container 10 is made transparent or semitransparent, so that the color of the reagent can be visually checked from the outside after causing a color reaction. The hermetic container 10 is preferably made of chemically stable synthetic resin such as polyethylene, polyethylene terephthalate, and nylon. The hermetic container 10 is made flexible so that it can be deformed by being depressed with a finger to let out air or gas 21 of the container or suck testing fluid 22 into the container.
The tap member 12 is formed of a string or rod material as shown in FIG. 1 for example and partly thrust in the hermetic container so as to be pulled out of the hermetic container 10 . The string-shaped (or rod-shaped) tap member 12 has a length, which is not specifically limited, so as not to come off accidentally. The tap member 12 is preferably made of chemically stable and flexible synthetic resin such as polyethylene, polypropylene, and polyethylene terephthalate.
On both end portions of the tube-like hermetic container 10 , there are formed seam portions 15 formed by thermally sealing the end portions of the container. In one of the seam portions 15 , the tap member 12 is partly embedded by the length corresponding to the width W of seam portion 15 as shown in FIG. 2 and FIG. 3 . With this structure, the hermetic container 10 (seam portion 15 ) and the tap member 12 come in contact with each other with a large area, consequently fixing tap creating resistance to a force for pulling up the tap member so as to prevent the tap member from coming off (being removed) accidentally. As is clear from FIGS. 1-3 , the tap member 12 extends entirely through the seam portion 15 to thereby extend from an exterior of hermetic container 10 to an interior of hermetic container 10 . In addition, the sealing performance of the hermetic container is elevated to prevent the color reaction reagent 11 from leaking through the hole 13 . Besides, even when the tap member 12 once pulled out is inserted into the container once again after sucking the testing fluid 22 into the container as described later, the testing fluid 22 sucked in the container can be prevented from leaking. The width W of the seam portion 15 is arbitrarily determined according to the size of the tap member 12 or other conditions. Where the width of the seam portion is too large, the resistance to the force for pulling out the tap member is needlessly increased. To be more specific, it is preferable to determine the width W of the order of 3 to 4 mm.
In the embodiment in FIG. 1 , the tap member 12 is provided on its one end with a finger hook 14 having a larger diameter than the other part. According to this structure, the tap member 12 can easily be removed from the container 10 by hooking a finger through the finger hook 14 and pulling. When the tap member 12 once pulled out is inserted into the container 10 , the finger hook 14 is caught on a through hole formed in the seam portion of the container to prevent the tap member 12 from being entirely inserted in the container 12 by accident. The way of forming the finger hook 14 is not specifically limited. The finger hook of the tap member may be made in the form of a mold ball yielded as the result of molding, or otherwise, the finger hook 14 separately prepared may be attached later to the stem of the tap member 12 with adhesives. Thus, the finger hook may be formed in this or other possible ways.
The tap member 12 may be formed in a different color from that of the hermetic container 10 . By coloring the tap member 12 in different color from that of the hermetic container 10 , the tap member 12 is highly visible to be easily distinguishable from other components, thus to permit a tester to work faster without feeling stress. However, the present invention of course encompasses the simplified analyzer comprising the tap member 12 and the hermetic container 10 of the same color or uncolored.
The hermetic container 10 may be provided with an analyzing data display 16 . The analyzing data display 16 indicates helpful information such as the content name (testing material “Cu” in FIG. 1 by way of example), representation of the limit value of analysis or other information. The information displayed may be marked by printing, embossing or other measures.
The tap member 12 can be inserted in the hermetic container 10 in the state of capable of being pulled out by the following method. That is, the tap member 12 may be set in the hermetic container by preheating the edge portion of the hermetic container 10 made of synthetic resin at temperatures above the melting point of Tg, and then, thermally sealing the preheated edge portion by welding while keeping the tap member 12 in the edge portion. Thus, the seam portion 15 is formed at the edge portion of the hermetic container 10 by thermally sealing to firmly seal the hermetic container, but the tap member 12 and the seam portion 15 never melt together so as to be separatable by pulling the tap member 12 . This is because the melting of the seam portion 15 is terminated before the tap member 12 reaches its melting point, although the tap member 12 is heated with the preheat applied to the hermetic container 10 . Furthermore, the tap member 12 comes in close contact with the hermetic container 10 , leaving no space therebetween, owing to the part in the molten state of hermetic container 10 , which flows into between the tap member 12 and the inside wall of the through hole 13 in the process of melting the hermetic container 10 , and by virtue of the elastic force brought about by the tap member 12 and hermetic container 10 . As a result, the simplified analyzer of the invention never leaks the color reaction agent 11 and the testing fluid 22 even when the tap member 12 is once pulled out and again inserted therein upon sucking the testing fluid 22 , as described later.
The melting points of the hermetic container 10 and the tap member 12 are not specifically limited, but it is preferable to use the hermetic container 10 and the tap member 12 having the same melting point or tap member 12 having a higher melting point than the hermetic container 10 to prevent the hermetic container 10 and the tap member 12 from being completely molten together. Thus, it is desirable to choose the materials of the hermetic container 10 and the tap member 12 so as to satisfy such conditions of the melting point. However, the present invention does not at all exclude use of the tap member 12 having a melting point lower than that of the hermetic container 10 . In the case of using the tap member 12 having the lower melting point, the hermetic container 10 and the tap member 12 can be certainly prevented from being melted together by controlling the melting conditions such as a pressure to be applied to the hermetic container 10 and the tap member 12 .
The tap member 12 can be pulled out, hooking a finger through the finger hook 14 of the tap member 12 . However, if the resistance brought about in pulling out the tap member 12 is a little more than necessary, it remains possible that the tap member 12 comes off accidentally. In such a case, the surface of the tap member 12 may be knurled so as not to come off with ease. Thus, the resistance to the force for pulling off the tap member 12 can be arbitrarily regulated. Moreover, one tip end of the tap member 12 (one of the tip ends of the tap member 12 , from which the tap member 12 is inserted into the hermetic container 10 ) protrudes outward over the other tip end as viewed in the longitudinal direction, to form a protrusion 24 , as shown in FIG. 7 . With this protrusion 24 , resistance to a force for pulling out the tap member 12 is brought about around the through hole 13 so as to prevent the tap member 12 from coming off accidentally with ease. The protrusion 24 may be formed separately from the tap member 12 by molding or integrally with the tap member 12 by using burr left in the process of molding the tap member 12 . The protrusion 24 may be suitably shaped according to need. It is a matter of course that the present invention encompasses the tap member having no protrusion 24 .
The simplified analyzer 1 described above is handled in use by first pulling out the tap member 12 to make the through hole 13 as shown in FIG. 4 , and then, pushing the hermetic container 10 with a finger 20 to extrude the air or other gas 21 out of the hermetic container 10 through the through hole 13 as shown in FIG. 5 . Next, the simplified analyzer is soaked in the testing fluid 22 to be analyzed, placing the through hole 13 under the testing fluid, and then, the finger 20 is released from the hermetic container 10 to suck the testing fluid 22 into the hermetic container 10 . Subsequently, upon shaking the hermetic container 10 if necessary, after the lapse of the prescribed time, the color of the fluid reacted with the color reaction reagent is compared with a standard color prepared separately as a reference color to determine the concentration of the testing fluid.
After sucking the testing fluid 22 into the hermetic container 10 in performing the aforesaid water quality analysis, the tap member 12 once pulled out is again inserted into the through hole 13 to prevent the testing fluid 22 from leaking from the hermetic container. The reason why the testing fluid 22 can be prevented from leaking out is uncertain, but it is more than probable that it is because the tap member 12 inserted into the through hole comes in tight contact with the inner wall of the through hole 12 in the seam portion 15 with elasticities of the tap member and seam portion, and the surface tension of the testing fluid 22 is not as low as the fluid leaks out. Since the testing fluid 22 does not leak, the problems such that the leaked liquid may stain clothes and influence the human body harmfully can be eliminated.
The other tip end of the tap member 12 (the tip end from which the tap member 12 is inserted into the hermetic container 10 ) may be formed in an acuminate shape if desired. The acuminate shape of the tap member may be formed by cutting the tip end of the tap member slantwise or tapering the tap member toward the tip end as shown in FIG. 7 . With the tap member having the acuminate tip end, even when the tap member 12 is pulled out, it can easily be inserted into the through hole 13 once again. The method for forming the acuminate shape of the tap member is not specifically limited, but it is better to cut the tip end of the tap member 12 slantwise to form the acuminate shape. It is a matter of course that the present invention encompasses the tap member having its tip end cut orthogonally to the longitudinal direction.
As an alternative, another tap member prepared separately may be inserted into the through hole 13 in place of the tap member 12 pulled out from the hermetic container to prevent the testing fluid from leaking out. In this case, the tap member 12 prepared separately may be tapered toward the tip end so as to be easily inserted into the through hole 13 .
The aforementioned simplified analyzer 1 may be packed with a moisture-proof wrapping 17 as shown in FIG. 8 and FIG. 9 . Thus, even when higher moisture-proofing property is required for the hermetic container 10 and the tap member 12 , deterioration and deliquescence of the color reaction reagent 11 can assuredly be prevented. The moisture-proof wrapping 17 may be formed of synthetic resin sheet, synthetic resin sheet laminated with metallic foil, or the like. In packing the simplified analyzer 1 , a drying agent, though not shown in the accompanying drawings, may be contained in the wrapping together with the simplified analyzer 1 if required. The method for packing the simplified analyzer 1 in the wrapping is not specifically limited, but it may be cited that the simplified analyzer 1 can be packed by being contained with the tube-like wrapping 17 made of film or sheet and sealing the both ends of the tube-like wrapping by thermal welding or ultrasonic welding.
FIG. 8 illustrates one simplified analyzer 1 packed in the wrapping, and FIG. 9 illustrates five simplified analyzers packed in the wrapping by way of example. Thus, the number of simplified analyzers packed is not specifically limited. As shown in FIG. 8 and FIG. 9 , a V-cut 18 may be formed in one edge portion of the moisture-proof wrapping 17 so as to make it easier to take out the simplified analyzer 1 from the wrapping by tearing the wrapping from the V-cut 18 .
In the embodiment described above, the color reaction reagent 11 is sealed in the container by way of example, but any fluid or material visible from the outside of the container may be contained therein. As one example, a reaction reagent for precipitation may be used.
Furthermore, the aforementioned embodiment includes the hermetic container 10 made transparent or semitransparent in its entirety, but the hermetic container 10 may be made transparent or semitransparent in part as long as the contents in the container can be visibly checked from the outside.
Only the manner of using the simplified analyzer 1 for making an analysis of water quality was described above, but the simplified analyzer of the invention may be applied for gas detection or the like.
As is apparent from the foregoing disclosure, the simplified analyzer 1 according to the present invention can easily be handled in safety by anyone only by pulling out the tap member 12 to let out the air of the hermetic container 10 and suck the testing fluid into the hermetic container 10 without using any separate tool such as a pin. Furthermore, since the simplified analyzer 1 of the invention intrinsically has the tap member 12 , the through hole 13 having a desirable diameter can be made at a suitable position of the hermetic container 10 for sucking the testing fluid into the container 10 , consequently to eliminate differences between individuals in conducting various kinds of analyses and enhance the reliability of analysis. | There is provided a simplified analyzer including a see-through hermetic container having powdery or granular color reaction reagent, and a tap member partially inserted in the hermetic container in an extractable state. The tap member is provided at one end with a finger stopper larger in diameter than another portion, so as to be drawn out while holding the finger stopper with user's fingers to form a through hole for letting air out of the hermetic container and applying suction to the testing liquid to be analyzed. By using the tap member prepared in advance, the through hole having a suitable diameter for applying suction to the testing liquid to be analyzed can be formed at the appropriate point in the container. According to the analyzer of the invention, differences among individuals in performing an analyzing test do not occur. | 1 |
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with government support under grant DE-AC26-07NT42677 awarded by the Department of Energy (DOE). The government has certain rights in the invention.
BACKGROUND OF THE INVENTION
This invention relates generally to electrodialysis and, more particularly to electrolyte chemistry control in electrodialysis processing
Electrodialysis is a membrane separation technology in which stacked pairs of selective cationic and anion selective membranes are typically used to segregate increasingly dilute salt streams from concentrated salt streams. Stacks of membrane pairs can be very large and can include 10 to 100 or more pairs of alternating membranes. At one end of the stack, electrochemical reactions are produced by a cathode in electrolyte solution. At the other end of the stack, another reaction is created by an anode in electrolyte solution. In the usual process, the electrolyte stream is separated from the dilute salt and the concentrated salt flows. The electrolyte solution is continuously applied to the electrodes.
Electrodialysis processing is conventionally driven by the hydrolysis of water, which is caused by applying a voltage across an electrode pair. The production of the gases oxygen and hydrogen are well known and thought to follow chemical reactions as in Equations A1 and C1 at the anode (A1) and at the cathode (C1).
H
2
O
→
1
2
O
2
+
2
H
+
+
2
e
-
E
o
=
-
1.229
V
A1
)
2
H
2
O
+
2
e
-
→
H
2
+
2
OH
-
E
o
=
-
0.8277
V
C1
)
FIG. 1 is a schematic of a conventional electrodialysis membrane stack arrangement, generally designated by the reference numeral 10 . The electrodialysis membrane stack arrangement 10 includes an anode electrode cell 12 , a cathode electrode cell 14 and a membrane stack (also sometimes simply referred to as a “stack”) 16 appropriately disposed between the anode and the cathode cells.
The membrane stack 16 includes alternating cationic selective membranes 20 (and specifically identified by the references 20 a , 20 b , 20 c . . . ) and anionic selective membranes 22 (and specifically identified by the references 22 a , 22 b , 22 c . . . ), beginning and ending with cationic selective membranes 20 a and 20 f . By the nature of how the selective membranes are alternated, the flow of anions and cations are caused to become concentrated in one cell pair and diluted in an adjacent cell pair. As shown a manifold system is used to isolate the flow of concentrate (in a concentrate manifold 30 ) from the flow of diluate (in a diluate manifold 32 ).
The terminal cationic membranes 20 a and 20 f , located at either end of the cell stack, serve to isolate the cathode within a cathode cell and the anode within an anode cell, each cell being located on opposite sides of the stack (not shown). As shown in FIG. 1 , the terminal cationic selective membranes 20 a and 20 f also isolate a respective flow area where a flow of electrolyte solution is supplied to the electrodes.
As shown in this representation, sodium ions or other cations, can pass through the cation selective membranes 20 . However, the cations are rejected by the anion selective membranes 22 . Likewise, chloride ions, or other anions can pass through the anion selective membrane 22 , but are rejected by the cation selective membranes 20 .
FIG. 1 also shows the dynamic balance between all the cells of the electrodialysis stack. Very importantly, sodium (Na+) plays a crucial balancing role in the proper operation of the electrodes. Because each electrode is isolated from in its corresponding electrolyte by a cationic selective membrane, this means that the ionic current is particularly dependent on sodium transport. However, if the cationic membrane allows calcium or magnesium transport, then these ions will pass into the electrolyte solution.
Electrodialysis has been conventionally used to treat light brine (e.g., brine that in general contains less than 1% salt and in some cases salt in a relative amount of as few as few hundred parts per million).
The application of electrodialysis processing to the treatment or processing of highly concentrated brines, especially those that contain a high concentration of soluble calcium, or other multivalent cations, can be particularly challenging.
For example, a practical problem in applying electrodialysis to the treatment of waters with calcium levels in the range of up to or about 100 mg/l is that a significant flux of calcium can occur through the cationic membrane from the stack cell adjacent to the cathode electrolyte cell to cause scale to form on the cathode and cause precipitates of calcium sulfate and other divalent sulfates to form in the electrolyte solution.
Furthermore, if soluble calcium or some other multivalent cation is transported into the electrolyte solution, then this cation can readily increase resistance to ion flow by fouling the electrode cell (specifically at the cathode) by forming precipitated calcium salts such as calcium hydroxide, or calcium sulfate. This greatly reduces the effective amperage and the rate of ion flux in the electrodialysis stack.
The prior art suggests that all cationic membranes within a stack be made of the same material. As such, if cationic membranes allow calcium flow, then soluble calcium will be transported across the cathode isolation membrane, and thus be integrated into the electrolyte solution. If calcium exclusionary membranes are utilized in all cells of the electrodialysis stack, then calcium cannot be collected in the concentrate and it will remain in diluate stream. This would be deleterious to the overall performance of the process.
Moreover, other divalent cations with similar chemistry to calcium, specifically barium, strontium, and radium, may be encountered in certain brines. An example of such a brine is flowback water from natural gas extraction from shale formations. In view thereof, it can be highly advantageous and sought to exclude these compounds, as well as calcium, from the electrolyte.
One widely used electrolyte solution is concentrated disodium sulfate. The aforementioned divalent cations, such as calcium, barium, and radium, are known to have very low solubility in the presence of sulfate. Thus it can be desirable to be able to use the standard disodium sulfate solution as the electrolyte without the danger of precipitating and concentrating unwanted cations in the electrolyte.
In view of the above, there is a need and a demand for improvements in electrodialysis processing. Further, there is need and a demand for improved control of electrolyte chemistry in such processing. Still further, there is a need and a demand for improvements in minimizing cation fouling, particularly, multivalent fouling in electrodialysis processing.
SUMMARY OF THE INVENTION
A general object of the invention is to provide improved electrodialysis and, more particularly, to minimization of cation fouling in electrodialysis processing.
A more specific objective of the invention is to overcome one or more of the problems described above or to otherwise appropriately address one or more of the above-identified and described needs and demands.
In accordance with one aspect of the invention, a method for controlling electrolyte chemistry such as in an electrodialysis unit that includes an anode and a cathode each in an electrolyte of a selected concentration and a membrane stack disposed therebetween. In such a unit, the membrane stack typically includes pairs of cationic selective and anionic membranes to segregate increasingly dilute salts streams from concentrated salts stream.
As detailed below, in accordance with one embodiment, a desirable method for controlling electrolyte chemistry involves application of at least one technique selected from the group consisting of using a single calcium exclusionary cationic selective membrane at a cathode cell boundary, using an exclusionary membrane configured as a hydraulically isolated scavenger cell, using a multivalent scavenger co-electrolyte and combinations thereof.
Another aspect of the invention relates to specific improvements in electrodialysis units that include an anode and a cathode each in an electrolyte of a selected concentration and a membrane stack disposed therebetween, the membrane stack comprising pairs of cationic selective and anionic membranes to segregate increasingly dilute salts streams from concentrated salts stream. As detailed below, in one embodiment such improvement involves placement of a single calcium exclusionary cationic selective membrane at a cathode cell boundary to minimize transport of multivalent cations into the cathode cell.
In another improvement embodiment, relates to placing or disposing an exclusionary membrane configured as a hydraulically isolated scavenger cell in the membrane stack.
As used herein, references to electrodialysis in “high brine conditions” are to be understood to generally refer electrodialysis processing at total dissolved solids (TDS) levels of at least about 0.5% TDS, and in some cases more or greater than 1% TDS, and typically up to about 8% TDS.
Other objects and advantages will be apparent to those skilled in the art from the following detailed description taken in conjunction with the appended claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified schematic of a conventional electrodialysis membrane stack arrangement.
FIG. 2 is a simplified schematic of an electrodialysis membrane stack arrangement as modified in accordance with one aspect of the invention.
FIG. 3 is a simplified schematic of an electrodialysis membrane stack arrangement as modified in accordance with another aspect of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides improved electrodialysis and, more particularly, to improved electrolyte chemistry control in electrodialysis processing
Turning to FIG. 2 , there is shown a simplified schematic of an electrodialysis membrane stack arrangement, generally by the reference 210 , in accordance with one aspect of the invention.
The electrodialysis membrane stack arrangement 210 is somewhat similar to the electrodialysis membrane stack arrangement 10 shown in FIG. 1 and discussed above. For example, the electrodialysis membrane stack arrangement 210 similar to the electrodialysis membrane stack arrangement 10 includes an anode electrode cell 212 , a cathode electrode cell 214 and a membrane stack 216 appropriately disposed between the anode and the cathode cells. Also, the membrane stack 216 includes alternating cationic selective membranes 220 (and specifically identified by the references 220 a , 220 b , 220 c . . . ) and anionic selective membranes 222 (and specifically identified by the references 222 a , 222 b , 222 c . . . ), beginning with the cationic selective membrane 220 a . Further, by the nature of how the selective membranes are alternated, the flow of anions and cations are caused to become concentrated in one cell pair and diluted in an adjacent cell pair. As shown a manifold system is used to isolate the flow of concentrate (in a concentrate manifold 230 ) from the flow of diluate (in a diluate manifold 232 ).
The electrodialysis membrane stack arrangement 210 , however, primarily differs from the electrodialysis membrane stack arrangement 10 by the placement or positioning of a single calcium exclusionary cationic selective membrane 220 f as the cathode cell boundary. All other cationic selective membranes within the electrodialysis membrane stack are non-exclusionary cationic membranes.
More particularly, and especially in processing of streams or waters containing high concentrations of soluble calcium, it has been found that the cationic selective membrane at the cathode is beneficially a special membrane material that allows for the transport of monovalent cations, such as sodium, but limits the transport of divalent cations such as calcium or magnesium or other multivalent metals that form precipitates with the anions present in the electrolyte solution. Furthermore, the selective membrane at the anode desirably should allow transport of all cationic species.
Those skilled in the art and guided by the teachings herein provided will understand and appreciate that practice of the invention can desirably prevent, avoid, minimize or overcome at least some of the above-discussed problems associated with transport of soluble calcium into the electrolyte solution.
For example, practice of the invention can desirably prevent, avoid, minimize or overcome problems associated with transport of soluble calcium into the electrolyte solution such as leading to increased resistance to ion flow by fouling the electrode cell (specifically at the cathode) such as by the formation of precipitated calcium salts such as calcium hydroxide or calcium sulfate and the resulting reduction in the effective amperage of the electrodialysis stack at a specific voltage.
Moreover, compounds containing other divalent cations with similar chemistry to calcium, including specifically, for example, barium, strontium, thorium and radium, can be excluded, as well as calcium, from the electrolyte.
Furthermore, the invention permits the more widespread usage of disodium sulfate solution as an electrolyte with reduced danger of precipitating and concentrating unwanted cations in the electrolyte.
In accordance with one embodiment, a single Tokyama CMX-S, exclusionary membrane (which is a composite material comprised of a polymerized aniline layer on a poly(styrene sulfonic acid) membrane base) rejected about 80% of the flux of calcium into the electrolyte and has been found to be a suitable single calcium exclusionary cationic selective membrane for use in the practice of the invention. More specifically, practice of electrodialysis with the use of such a single calcium exclusionary cationic selective membrane as the cathode cell boundary manages to permit calcium to migrate into the electrolyte but avoids electrolyte, membrane and/or cell fouling.
It is believed that the likely mechanism by which such inclusion and placement of such a single, exclusionary membrane operates is that the exclusionary membrane reduces the rate of fouling by rejecting calcium from the posterior surface inside the catholyte cell. However, we have further found that there is a surprising duality to the action of the single exclusionary membrane. On the anterior side (toward the diluate cell), the membrane minimizes the flux of calcium passing the membrane. On the posterior side (inside the catholyte cell), any passed calcium enters the electrolyte without immediately fouling the membrane.
Thus, this aspect of the invention provides a novel means of limiting the degradation of electrolyte solutions and limiting resistance to ion flow in electrodialysis processing by selectively minimizing transport of calcium, magnesium or other multivalent cations into the cathode cell by use of a single calcium exclusionary cationic selective membrane at the cathode cell boundary.
Further, the invention allows the use of standard electrolyte solution disodium sulfate, even in the presence of undesirable cations such as calcium, barium, or radium, which are known to precipitate as the sulfate salt.
Still further, the invention allows the use of electrolytes that are at elevated pH, such as pH 11-12.5, without the associated problems of precipitation of hydroxide salts.
In accordance with another aspect of the invention, a novel method and hydraulic system is introduced for electrodialysis processing. As detailed below, the new method and system desirably reduce, minimize and preferably avoids or eliminates the potential for multivalent cation transport into the electrolyte at the cathode. A multivalent scavenger cell is created by two cation selective multivalent exclusionary membranes and an anion selective membrane. In one preferred configuration, a scavenger cell is constructed with one multivalent cation exclusionary membrane immediately adjacent to the cathode. The proximal membrane is the anion selective membrane. The final multivalent cation exclusionary membrane is proximal to the aforementioned anion selective membrane. The hydraulics of the scavenger cell are isolated from the other flows in the electrodialysis stack, i.e., the electrolyte, the diluate, and the concentrate. In such configuration, cations such as calcium must pass an exclusionary membrane, a cleansed solution tailored for multivalent cation capture, and a second exclusionary membrane in order to be transported into the electrolyte in the cathode cell. The fluid applied to the scavenger cell is a co-electrolyte chemically tailored for capture of the multivalent cations. If desired, an external filter or ion exchange bed can used to continually cleanse the co-electrolyte of the multivalent cations.
Turning to FIG. 3 , there is shown a simplified schematic of an electrodialysis membrane stack arrangement, generally by the reference 310 , in accordance with one embodiment of this aspect of the invention.
The electrodialysis membrane stack arrangement 310 is somewhat similar to the electrodialysis membrane stack arrangement 10 shown in FIG. 1 and discussed above. For example, the electrodialysis membrane stack arrangement 310 similar to the electrodialysis membrane stack arrangement 10 includes an anode electrode cell 312 , a cathode electrode cell 314 and a membrane stack 316 composed of alternating cationic selective membranes 320 (and specifically identified by the references 320 a , 320 b , 320 c , . . . ) and anionic selective membranes 322 (and specifically identified by the references 322 a , 322 b , 322 c , . . . ) appropriately disposed between the anode and the cathode cells. A manifold system is used to isolate the flow of concentrate (in a concentrate manifold 330 ) from the flow of diluate (in a diluate manifold 332 ).
The electrodialysis membrane stack arrangement 310 , however, differs from the electrodialysis membrane stack arrangement 10 via the creation and placement of a scavenger cell 340 adjacent the cathode electrode cell 314 . In accordance with one preferred embodiment, the scavenger cell 340 is generally composed of an electrochemical cell formed by replacing two generic cation selective membranes with two multivalent cation exclusionary membranes 342 a and 342 b . A first of the multivalent cation exclusionary membrane replacements is the membrane 342 a immediately adjacent to the cathode 314 . The anion selective membrane 322 e immediately proximal to the membrane 342 a remains. A second of the multivalent cation exclusionary membrane replacements is the proximal membrane 342 b . This forms an electrochemical cell pair that allows cation flow toward the cathode and anion flow toward the anode.
The scavenger cell 340 is desirably hydraulically isolated from both the water flow cells (concentrate and diluate) and the electrolyte flow, as shown with a scavenger cell flow path 350 .
Further, the fluid in the scavenger cell can desirably be chemically tailored for the collection of the unwanted cations. For example, in one embodiment, sulfate or phosphate ions may be used to precipitate the multivalent cations. If desired, an external filter can be used to capture the precipitate. For example, in an alternative embodiment, chloride, nitrate, or other anion that is not readily precipitated can be used to keep undesired multivalent cation(s) in solution. A chelating agent such sodium EDTA could be used to further discourage precipitation. The offending cations can, if desired and as shown, be captured or removed via an external filter and/or an ion exchange bed 352 , with fluid return via line 354 . In practice, the total flow and total volume of the scavenger can be minimal compared to the electrolyte volume and treated water volume.
Those skilled in the art and guided by the teachings herein provided will further understand and appreciate that if desired, the scavenger cell concept, as modified, can be applied anywhere within the electrodialysis stack. That is, the scavenger cell concept described herein can be applied anywhere within the electrodialysis stack where it may be advantageous to cleanse the diluate of offending cations. In such applications, the cation exchange membrane toward the cathode would be a multivalent cation exclusionary membrane and the second cation selective membrane toward the anode would allow passage of all cations. The scavenger cells could be alternated with the normal cell pairs (concentrate and diluate) and could occupy as many as 50% if the total cell pair positions. The resultant electrodialysis stack would have the effect of scavenging a majority of the multivalent cations from the diluate flow.
Thus, the invention provides improved electrodialysis and, more particularly, improved electrolyte chemistry control in electrodialysis processing
It is to be understood that the discussion of theory, such as the discussion relating to how or why the inclusion and placement a single calcium exclusionary cationic selective membrane at a cathode cell boundary beneficially prevents, avoids or minimizes electrolyte, membrane and/or cell fouling, for example, is included to assist in the understanding of the subject invention and is in no way limiting to the invention in its broad application.
The invention illustratively disclosed herein suitably may be practiced in the absence of any element, part, step, component, or ingredient which is not specifically disclosed herein.
While in the foregoing detailed description this invention has been described in relation to certain preferred embodiments thereof, and many details have been set forth for purposes of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention. | Methods for controlling electrolyte chemistry in electrodialysis units having an anode and a cathode each in an electrolyte of a selected concentration and a membrane stack disposed therebetween. The membrane stack includes pairs of cationic selective and anionic membranes to segregate increasingly dilute salts streams from concentrated salts stream. Electrolyte chemistry control is via use of at least one of following techniques: a single calcium exclusionary cationic selective membrane at a cathode cell boundary, an exclusionary membrane configured as a hydraulically isolated scavenger cell, a multivalent scavenger co-electrolyte and combinations thereof. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/962,276, filed Nov. 5, 2013 and entitled “Bifurcated Stent and Delivery System,” which is incorporated herein by reference in its entirety.
FIELD OF INVENTION
[0002] The field of invention is generally related to medical stents and related delivery systems. More specifically, the invention relates to specifically designed stents and techniques for deploying these stents into vessel bifurcations, allowing for better coverage of the atherosclerotic lesion and preservation of the side-branch ostium with proper stent strut apposition to the vessel walls. The invention overcomes many of the limitations of the previous art.
BACKGROUND
[0003] A stent is a mesh ‘tube’ inserted into a natural passage/conduit in the body to remove or counteract a disease-induced, localized flow constriction. The term may also refer to a tube used to temporarily hold such a natural conduit open to allow access for surgery.
[0004] Most of the time, stents are used to treat conditions that result when arteries become narrow or blocked. When a stent is placed into the body, the procedure is called stenting. A stent is placed in an artery as part of a procedure called angioplasty. Angioplasty restores blood flow through narrow or blocked arteries. A stent helps support the inner wall of the artery after angioplasty.
[0005] Stents are generally tubular devices for insertion into body lumens. Balloon expandable stents require mounting over a balloon, positioning, and inflation of the balloon to expand the stent radially outward. Self-expanding stents expand into place when unconstrained, without requiring assistance from a balloon. A self-expanding stent is biased so as to expand upon release from the delivery catheter. Some stents may be characterized as hybrid stents which have some characteristics of both self-expandable and balloon expandable stents. Almost all stents used in the treatment of coronary atherosclerosis are balloon expandable. Self-expandable stents are generally used in larger blood vessel in the limbs and periphery.
[0006] There are different kinds of stents. Stents usually are made of metal mesh of various metals and alloy combinations. Some stents are a plastic mesh-like material, and some stents are a combination of metal and synthetic lining material (for example PTFE-Polytetrafluoroethylene) and are called stent grafts and are used in larger arteries.
[0007] An intraluminal coronary artery stent is a small, balloon-expandable, metal mesh tube that is placed inside a coronary artery to prevent the artery from re-closing. The metal portion of the structure is called a strut and the open portion of the mesh between struts is called a cell. Re-narrowing of arteries at the site of stent deployment has been addressed with medicine coated stents, called drug-eluting stents. Like other coronary artery stents, it is left permanently in the artery.
[0008] Stents may be constructed from a variety of materials such as stainless steel, Elgiloy®, nitinol, shape memory polymers, etc. Stents may also be formed in a variety of manners as well. For example a stent may be formed by etching or cutting the stent pattern from a tube or section of stent material; a sheet of stent material may be cut or etched according to a desired stent pattern whereupon the sheet may be rolled or otherwise formed into the desired tubular or bifurcated tubular shape of the stent; one or more wires or ribbons of stent material may be braided or otherwise formed into a desired shape and pattern.
[0009] Repair of coronary vessels that are diseased at a bifurcation is particularly challenging since the stent must be precisely positioned, provide adequate coverage of the disease, provide access to any diseased area located distal to the bifurcation, and maintain vessel patency in order to allow adequate blood flow to reach the myocardium.
[0010] Currently employed techniques have results that are less favorable than stenting results for lesions that do not involve bifurcations. The most commonly employed technique is to introduce guide-wires into the main blood vessel (parent-vessel) and the side branch (daughter-vessel). The ostium of the daughter-vessel is treated with balloon angioplasty and then a stent is deployed in the parent-vessel as if there was no bifurcation involvement. The hope is to have a stent cell line up with the ostium of the daughter-vessel resulting in unobstructed flow. However, in reality this is not always the case and stent struts usually are left in the ostium increasing the risk of acute and subacute stent thrombosis. Also promotion of neointimal growth onto the unopposed struts can result in renarrowing. A daughter-vessel is in effect “jailed” by the stent and blood flow can continue to be compromised results in inadequate treatment.
[0011] Another phenomenon that is of concern in treatment of bifurcations is plaque shift. When a balloon or a stent is deployed in an artery, the plaque is compressed against the vessel wall. However, if there is a side branch ostium that is being stented across, plaque just beyond the bifurcation moves and shifts into the side branch resulting in worsening of the narrowing in this vessel. Plaque shift is of greatest concern when the plaque is located on the carina or the apex of the bifurcation.
[0012] Alternatively, access into a jailed vessel can be attained by carefully placing a guide-wire through the stent, and subsequently tracking a balloon catheter through the stent struts. The balloon could then be expanded, thereby deforming the stent struts and forming an opening into the previously jailed vessel. The cell to be spread apart must be randomly and blindly selected by re-crossing the deployed stent with a guide-wire. The drawback with this approach is that there is no way to determine or guarantee that the main-vessel stent struts are properly oriented with respect to the side branch or that an appropriate stent cell has been selected by the wire for dilatation. The aperture created often does not provide a clear opening and creates a major distortion in the surrounding stent struts. A further drawback with this approach is that there is no way to tell if the main-vessel stent struts have been properly oriented and spread apart to provide a clear opening for stenting the side branch vessel. This technique also causes stent deformation to occur in the area adjacent to the carina, pulling the stent away from the vessel wall and partially obstructing flow in the originally non-jailed vessel. Deforming the stent struts to regain access into the previously jailed vessel is also a complicated and time consuming procedure associated with attendant risks to the patient and is typically performed only if considered an absolute necessity. The deformation of the contralateral struts has been addressed by doing a simultaneous inflation with two balloons, one being placed in the parent and the other in the daughter-vessel. The inability to place a guide-wire through the jailed lumen in a timely fashion could restrict blood supply and begin to precipitate symptoms of angina, resulting in myocardial infarction or even cardiac arrest.
[0013] Other methods employed include a “T-stent” procedure. This involves implanting a stent in the daughter-vessel ostium followed by stenting of the parent-vessel across the daughter-vessel. Subsequently deforming the struts as previously described, to allow blood flow and access into the daughter-vessel. Alternatively, a stent is deployed in the parent-vessel followed by subsequent strut deformation as previously described, and finally a stent is placed into the daughter-vessel. Stent deployment in the ostium of the daughter-vessel may be necessary if there is a significant plaque burden at the bifurcation and involves the ostium of the daughter-vessel. Conversely stenting of the daughter-vessel may be required to treat a possible dissection created by the initial angioplasty. T-stenting would theoretically be useful in situations where the angle between the parent and daughter vessels is 90-degrees. This is rarely the case in real life and the alignment of the stent in the daughter-vessel with the apex of the carina results in inadequate coverage of the ostium. Alignment of the stent to the beginning of the side branch ostium results in protrusion of stent struts into the parent-vessel lumen. Both scenarios increase the risk of subsequent complications and renarrowing.
[0014] In another prior art method for treating bifurcated vessels, commonly referred to as the “Culotte technique,” the side branch vessel is first stented so that the stent protrudes into the main or parent vessel. A dilatation is then performed in the main or parent vessel to open and stretch the stent struts extending across the lumen from the side branch vessel. Thereafter, a stent is implanted in the main branch so that its proximal end overlaps with the already-stented side branch vessel. One of the drawbacks of this approach is that the orientation of the stent elements protruding from the side branch vessel into the main vessel is completely random. In addition excessive metal coverage exists from overlapping strut elements in the parent vessel proximal to the carina area. Furthermore, the deployed stent must be recrossed with a wire and arbitrarily selecting a particular stent cell. When dilating the main vessel the stent struts are randomly stretched, thereby leaving the possibility of restricted access, incomplete lumen dilatation, and major stent distortion.
[0015] In another prior art procedure, known as “kissing” stents, a stent is implanted in the main vessel with a side branch stent partially extending into the main vessel creating a double-barrelled lumen of the two stents in the main vessel distal to the bifurcation. Another prior art approach includes a so-called “trouser legs and seat” approach, which includes implanting three stents, one stent in the side branch vessel, a second stent in a distal portion of the main vessel, and a third stent, or a proximal stent, in the main vessel just proximal to the bifurcation.
[0016] All of the above-mentioned examples of stent deployment techniques suffer from the same problems and limitations. There can be uncovered intimal surface segments on the daughter-vessel between the stented segment and the parent-vessel or there is excessive coverage in the parent vessel proximal to the bifurcation. An uncovered intimal surface with a possible dissection flap or uncompressed plaque will increase the risk for sub-acute thrombosis, and the increased risk of the development of restenosis. Further, where portions of the stent are left unapposed within the lumen, the risk for subacute thrombosis or the development of restenosis is increased also. The prior art stents and delivery assemblies for treating bifurcations are difficult to use and deliver making successful placement nearly impossible. Further, even where placement has been successful, the side branch vessel can be “jailed” or covered so that there is impaired access to the stented area for subsequent intervention.
[0017] Prior art Tryton bifurcation stent with trizone technology suffers from the same limitation of requiring to recross the stent struts of the parent-vessel stent with an arbitrary selection of a cell and subsequent deformation along with all its limitations as previously described.
[0018] One prior art stent that is specifically designed for bifurcations in the petal stent from Boston Scientific. This has a specifically designed collar which expands radially into the ostium of the daughter vessel. The collar is designed as radially placed struts covering the entire perimeter of the ostium. The symmetry of the collar is believed to be a drawback as most bifurcations have non-90° take off angles, and so the collar would create an unnecessary and excessive crowding or deformation of struts in the ostium.
[0019] The key element in the successful treatment of bifurcation with current art/technology is the simultaneous “kissing” balloon inflation. Successful placement of a guide-wire through the struts of the stent in the parent-vessel is essential for this to occur. Inability to cross with a guide-wire into the daughter-vessel would leave stent struts in the ostium and unopposed to the intimal surface. The present invention solves these and other problems as will be shown.
SUMMARY
[0020] The prior art deficiencies and other problems associated with bifurcated stents and related delivery systems are overcome by the disclosed invention. It is an objective of the present invention to provide a bifurcated stent system that is easily delivered and deployed with precise positioning at a bifurcation. The invention simplifies the bifurcation stent delivery system eliminating the crucial and often failed step of recrossing with a guide-wire. It also eliminates the issue of uncovered intimal surface in the daughter-vessel and strut protrusion in the parent-vessel.
[0021] The preferred embodiment of the invention provides a bifurcated stent and related delivery system that allows retaining the guide wire in the daughter branch during the stent deployment in the parent vessel. It provides for coverage of the area of the ostium of the daughter vessel with precise placement of the parent vessel stent. The system provides for precise placement of the daughter vessel stent as well.
[0022] In another embodiment of the invention, the side branch (daughter vessel) stent could be used for placement in the ostial location of a single vessel.
[0023] Other embodiments of the invention with variation in length and diameter in conjunction with other standard stents can be utilised for treatment of plaque in the left main artery location effectively dealing with the ostial placement of the left main stent and as well as the left main/left anterior descending and left circumflex coronary artery bifurcation.
[0024] In summary the preferred embodiment of the invention provides a bifurcated stent and related delivery system that is deliverable and effectively overcomes the limitations of the prior art. Accurate placement, proper strut apposition, adequate coverage of intimal surfaces and preservation of the geometry of the side branch ostium will result in proper treatment of plaque at or near bifurcations. Part of the system can be used for accurate placement of stents in the ostial location.
[0025] According to a first aspect of the invention, a stent system is provided for stenting a bifurcated vessel structure having a parent vessel and a daughter vessel. The stent system has a parent vessel stent and a daughter vessel stent. The parent vessel stent has a substantially tubular body that is configured to be deployed into the parent vessel. This body has an angular flap that is openable to extend into the daughter vessel. The daughter vessel stent has a substantially tubular body that is configured to be deployed through the flap in the parent vessel stent into the daughter vessel. The daughter vessel stent has an angled tail portion that is configured to overlap with the flap of the parent vessel stent when both stents are deployed in the vessel structure.
[0026] Preferably, the parent vessel stent includes an introduction site proximate to a leading edge of the body of the parent vessel stent, which allows for passage of a daughter vessel guide wire on the inside of the stent along a luminal side thereof.
[0027] Preferably, the parent vessel stent includes a radio-opaque marker proximate to this introduction site.
[0028] The parent vessel stent may be pre-loaded (or later wired with) a parent vessel guide wire disposed substantially coaxially inside the body of the parent vessel stent.
[0029] Preferably, the flap includes at least one radio-opaque marker.
[0030] In the preferred embodiment, the flap has struts allowing opening of the flap in one direction. Preferably, the struts extend only on one side and do not form a collar around an ostium of the daughter vessel when opened. Preferably, the flap has struts forming a periphery around the flap. The flap is preferably a specially designed area in the parent vessel stent with a strut configuration that is different from the strut configuration of the main body of the parent vessel stent. The strut configuration allows the segment to be opened up as a flap providing coverage along a proximal end of the daughter vessel. Preferably, there are no struts along the distal edge of the ostium of the daughter vessel with the edge of the flap segment of the patient's vessel being aligned to it.
[0031] In the preferred embodiment, the parent vessel stent has a spine which also extends along a central portion of the flap.
[0032] The parent vessel stent may be pre-loaded (or may be later provided) with a balloon for deployment of the parent vessel stent.
[0033] In certain embodiments, at least one of the parent vessel stent or the daughter vessel stent may contain a drug, or may be configured to elute a drug.
[0034] Preferably, the daughter vessel stent includes a side hole proximate to a trailing edge of the body of the daughter vessel stent for passage of a parent vessel guide wire. Preferably, the side hole is defined radially opposite the angled tail portion of the daughter vessel stent.
[0035] Preferably, the daughter vessel stent includes a radio-opaque marker proximate to the side hole.
[0036] The daughter vessel stent may be pre-loaded (or later wired with) a daughter vessel guide wire disposed substantially coaxially inside the body of the daughter vessel stent.
[0037] According to a second aspect of the invention, a method is provided for stenting a bifurcated vessel structure having a parent vessel and a daughter vessel and where the daughter vessel branches from the parent vessel at an angle. The daughter vessel has an ostium where it joins the parent vessel. The ostium in turn has a proximal edge and a distal edge. The method comprises:
[0038] (1) inserting a parent vessel guide wire and a daughter vessel guide wire into the parent and daughter vessels, respectively;
[0039] (2) loading a parent vessel stent on both wires, such that the parent vessel guide wire is substantially coaxial with the parent vessel stent; and such that the daughter vessel guide wire runs generally inside the parent vessel stent along its daughter vessel luminal side and emerges at a side hole in the parent vessel stent;
[0040] (3) positioning the parent vessel stent with the daughter vessel guide wire at the distal edge of the daughter vessel ostium;
[0041] (4) deploying the parent vessel stent with a first balloon;
[0042] (5) deploying a side flap formed in the parent vessel stent into the ostium of the daughter vessel using a second balloon mounted on the daughter vessel guide wire;
[0043] (6) loading a daughter vessel stent on the daughter vessel guide wire and inserting the parent vessel guide wire such that the parent vessel guide wire runs through a side hole in the daughter vessel stent, the daughter vessel guide wire being generally coaxial with the daughter vessel stent;
[0044] (7) positioning the daughter vessel stent with the parent vessel guide wire at the distal edge of the ostium of the daughter vessel; and
[0045] (8) deploying the daughter vessel stent with a third balloon.
[0046] Importantly, once deployed, the flap of the deployed parent vessel stent and an angled side wall of the deployed daughter vessel stent overlap and are apposed at least in part with the proximate edge of the ostium.
[0047] The method may further include predilating one or both vessels prior to inserting the parent vessel guide wire.
[0048] The method may further include removing plaque from one or both vessels prior to inserting the parent vessel guide wire.
[0049] The method may further include performing a kissing balloon inflation with a fourth balloon after deploying the daughter vessel stent for further shaping of the bifurcation.
BRIEF DESCRIPTION OF THE FIGURES
[0050] FIG. 1 is a simplified vessel diagram showing deployment of a parent vessel stent with jailing effect across side branch (prior art).
[0051] FIG. 2 a is a simplified vessel diagram showing deployment of a daughter vessel stent with protrusion into parent vessel (prior art).
[0052] FIG. 2 b is a simplified vessel diagram showing deployment of a daughter vessel stent with uncovered daughter vessel intima (prior art).
[0053] FIG. 3 is a simplified vessel diagram showing deployment using stent culotte technique (prior art).
[0054] FIG. 4 is a simplified vessel diagram showing deployment using stent crush technique (prior art).
[0055] FIG. 5 is a schematic diagram of a parent vessel stent system according to an embodiment of the present invention.
[0056] FIG. 6 is a simplified sectional view of the parent vessel stent system of FIG. 5 showing guide wires and deployment balloon.
[0057] FIG. 7 is a top view of the flap portion of the parent vessel stent shown in FIG. 5 .
[0058] FIG. 8 is a diagram showing stent in parent vessel with flap extended, showing strut arrangement.
[0059] FIG. 9 is a diagram showing stent in parent vessel with flap extended.
[0060] FIG. 10 is a schematic diagram of a daughter vessel stent system according to an embodiment of the present invention.
[0061] FIG. 11 is a simplified vessel diagram showing deployed side branch (daughter vessel) stent in relation to parent vessel.
[0062] FIG. 12 is a simplified vessel diagram showing a first stage of deployment process according to an embodiment of the present method (positioning of parent vessel stent).
[0063] FIG. 13 is a simplified vessel diagram showing a second stage of the deployment process (balloon inflation of parent vessel stent in the parent vessel).
[0064] FIG. 14 is a simplified vessel diagram showing a third stage of the deployment process (balloon opening of flap in parent vessel stent into daughter vessel).
[0065] FIG. 15 is a simplified vessel diagram showing a fourth stage of the deployment process (positioning of daughter vessel stent through flap in parent vessel stent).
[0066] FIG. 16 is a simplified vessel diagram showing a fifth stage of the deployment process (balloon inflation of daughter vessel stent in daughter vessel).
[0067] FIG. 17 is a simplified vessel diagram showing a sixth and final stage after removal of balloon and guide wires (showing overlap between daughter vessel stent and parent vessel stent to provide complete coverage of the bifurcation area without unopposed struts or jailing across the ostium).
DETAILED DESCRIPTION
[0068] Before embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of the examples set forth in the following descriptions or illustrated drawings. The invention is capable of other embodiments and of being practiced or carried out for a variety of applications and in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The system includes balloon expandable stents.
[0069] The preferred embodiment of the invention provides a bifurcated stent and related delivery system that is deliverable and effectively overcomes the limitations of the prior art. Accurate placement, proper strut apposition, adequate coverage of intimal surfaces and preservation of the geometry of the side branch ostium will result in proper treatment of plaque at or near bifurcations. Part of the system can be used for accurate placement of stents in the ostial location.
[0070] In the preferred embodiment of the invention, the following steps are taken for the deployment of the bifurcation stents of the invention:
[0071] 1. Wire both vessels.
2. Predilate both lesions. Calcified lesions may require debulking/atherectomy. 3. Backload “main vessel stent” on the wires, with the wire from the daughter-vessel being introduced through the side-hole in the flap area ( FIGS. 5 , 6 and 7 ). 4. Position the stent in the parent-vessel with daughter-vessel wire at the distal edge of its ostium ( FIG. 12 ). 5. Deploy stent ( FIG. 13 ) and remove stent delivery balloon. 6. Deploy the “side-flap” further by using a balloon on the side-branch wire ( FIG. 14 ). 7. Load “side branch stent”, this time with the wire from the parent vessel in the “side-hole” ( FIG. 10 ). 8. Position the stent with the wire from the “side-hole” (parent branch) at the edge of the ostium of the side branch ( FIG. 15 ). 9. Deploy stent ( FIG. 16 ) and remove the stent delivery balloon. 10. Perform “kissing” balloon inflation if needed for further shaping of the bifurcation.
[0081] FIGS. 1 through 4 demonstrate the various shortcomings of the prior art that are overcome by the present invention. Please note that not all permutations of prior art are presented here. However, the common issues with prior art include:
[0082] 1. Inadequate coverage of vessel intima (extent dependant on technique employed).
[0083] 2. Strut protrusion into adjacent vessel lumen.
3. Need to cross cells of a stent with a guide wire after its deployment. This is a very crucial and often limiting step in the treatment of bifurcation lesions with prior art.
[0085] Note that in the present system, wires cross through a flap of a deployed stent and through a marked introduction site, but do not need to be inserted through cells (between struts).
[0086] FIG. 1 shows prior art with deployment 100 of a stent 103 in the parent vessel 101 , across the ostium of the side branch 102 . This has the problems of jailing of the side branch 102 and also leaving unopposed stent struts 104 . These result in poor long term outcomes.
[0087] FIG. 2 a shows deployment 200 a of a stent 203 a in the daughter vessel (side branch) 202 a . The stent is aligned to the proximal edge of the ostium and has the problem of stent struts 204 a protruding into the lumen of the parent vessel (main branch) 201 a.
[0088] FIG. 2 b shows deployment 200 b of a stent 203 b in the daughter vessel (side branch) 202 b . The stent is aligned to the distal edge of the ostium and has the problem of leaving part of the intima of the daughter vessel uncovered 204 b.
[0089] FIG. 3 shows deployment 300 using the stent culotte technique (a suboptimal two-stent prior art technique for bifurcated vessels). Stents 303 and 304 are placed simultaneously in the daughter 302 and parent 301 vessels respectively. This results in unopposed stent struts 305 in the parent (main) vessel 301 .
[0090] FIG. 4 shows deployment 400 using the stent crush technique (another suboptimal two-stent prior art technique for bifurcated vessels). In this technique stent 404 is placed in the daughter vessel 402 first with the stent deliberately left protruding in the parent vessel. This stent is then crushed with deployment of a stent 403 in the parent vessel 401 . This results in a double layer of stent struts 405 across the daughter vessel ostium. It also has the problem of making it difficult to navigate the wire into the daughter vessel (side branch) through the struts of not one but two stents.
[0091] FIGS. 5 through 11 show at least one embodiment of the present system with the salient features of its various components, primarily the parent vessel stent (main artery) with the “flap” area and the daughter vessel (side branch) stent with the angled proximal edge.
[0092] FIG. 5 shows the basic design of the parent vessel system 500 with parent vessel stent 501 with “flap” area 502 . Advantages include keeping the daughter vessel guide wire 503 on the luminal side 504 of the stent thereby eliminating the need of trying to recross the struts of the stent in the parent vessel. Also location of the introduction site of the daughter vessel wire 505 in conjunction with the radio-opaque markers on the stent 506 allows positioning of the “flap” area at the ostium of the daughter vessel. The “flap” 502 in combination with the angled proximal edge of the daughter vessel (side branch) stent (not shown in FIG. 5 ) eliminates the uncovered intimal portion of the daughter vessel (i.e. the problem shown in FIG. 2 b , at 204 b ).
[0093] FIG. 6 shows a schematic of the cross section of the parent vessel stent catheter/stent system 600 . This cross section is proximal to the introduction site (reference character 505 in FIG. 5 ) of the daughter vessel guide wire 601 , showing its location on the luminal side of the stent 602 . The parent vessel guide wire 604 is coaxial in the center. The daughter vessel guide wire 601 is not coaxial and is in between the stent 602 and the deployment balloon 603 .
[0094] FIG. 7 shows the top view of the flap area 700 ( FIG. 5 at 502 ). The daughter vessel guide wire is introduced at introduction site 701 just proximal to the radio-opaque marker 702 . The folded struts and spine of the “flap” 704 are deployed by a balloon in the daughter vessel and provide coverage for the proximal edge of the ostium of the daughter vessel. Strut 703 forms a perimeter around the ostium of the daughter vessel. Some of these structures are shown again in FIGS. 8 and 9 below.
[0095] FIG. 8 shows parent vessel stent system 800 with stent deployed in the parent vessel 801 with flap extended into the ostium of the daughter vessel 802 . Struts 803 and 804 provide coverage to the ostium of the daughter vessel and strut 805 forms the perimeter around the ostium.
[0096] FIG. 9 shows parent vessel stent system 900 with parent vessel 901 stent 903 deployed with flap extended 904 into the ostium of the daughter vessel 902 .
[0097] FIG. 10 shows the basic structure of the daughter vessel (side branch) system 1000 with daughter vessel stent 1002 . Here the guide wire from the daughter vessel 1001 is coaxial in the center. The proximal edge of the stent is angled 1003 for coverage of the ostium in conjunction with the flap of the parent vessel stent. The guide wire from the parent vessel 1004 is introduced at side hole 1005 just proximal to the short side of the stent (i.e. opposite angled edge 1003 ). The radio-opaque marker 1006 helps with positioning of the stent.
[0098] FIG. 11 shows the daughter vessel system 1100 with deployed side branch (daughter vessel) 1102 stent 1103 in relation to the parent vessel 1101 .
[0099] Following FIGS. 12 through 17 show the deployment sequence of current system.
[0100] FIG. 12 shows positioning 1200 of parent vessel (main vessel) 1203 stent 1205 across the daughter vessel 1202 . The parent vessel guide wire 1204 is coaxial and guide wire from the daughter vessel 1201 is introduced through the flap in the parent vessel stent (region 502 shown in FIG. 5 ). The stent is then advanced till the daughter vessel guide wire 1201 is against the distal edge of the ostium 1207 . Placement is also assisted by observing and placing the radio-opaque marker 1206 just beyond the ostium of the daughter vessel.
[0101] FIG. 13 shows the deployment 1300 of parent vessel 1301 stent 1304 coaxially over the guide wire 1303 with balloon inflation 1302 ; the daughter vessel 1305 guide wire 1306 is retained and, being on the inside of the stent in area 1307 , is not trapped.
[0102] FIG. 14 shows a further deployment 1400 of the parent vessel stent using standard angioplasty balloon 1401 which is used in this case to raise/extend the flap portion 1402 of the parent vessel 1405 stent 1406 . The balloon is placed coaxially over the guide wire 1403 in the daughter vessel 1404 . The guide wire 1407 in the parent branch is retained. The radio-opaque marker 1408 on the edge of the flap shows the area of coverage on the proximal edge of the ostium of the daughter branch.
[0103] FIG. 15 shows positioning 1500 of the daughter vessel 1501 (side-branch) stent 1506 at the ostium, using the parent vessel guide wire 1503 and radio-opaque marker 1505 on the stent as guides. The parent vessel guide wire 1503 is introduced through the “side-hole” in the stent catheter located just proximal to the short side of the stent ( 1005 FIG. 10 ). The daughter vessel stent 1506 is advanced through the flap of the parent vessel stent 1504 , as far as permitted by the guide wire in the parent vessel. Positioning is also assisted by the radio-opaque marker 1505 .
[0104] FIG. 16 shows deployment 1600 of the daughter vessel 1601 stent 1606 . Parent vessel guide wire 1603 is retained. The overlap 1605 of the angled edge with the flap 1607 of the parent vessel stent 1604 provides total coverage of the proximal edge of the ostium.
[0105] FIG. 17 shows the final deployed state of the bifurcation stent system 1700 . The overlap segment 1705 between the flap 1706 of the parent vessel 1701 stent 1703 and the angled proximal edge 1707 of the daughter vessel 1702 stent 1704 allows for adequate coverage of the ostium of the daughter vessel. The system provides such coverage over a wide range of “take-off” angles between the parent and daughter vessels.
[0106] The intent of the application is to cover all practical combinations and permutations. The above examples are not intended to be limiting, but are illustrative and exemplary.
[0107] The examples noted here are for illustrative purposes only and may be extended to other implementations. While several embodiments are described, there is no intent to limit the disclosure to the embodiment(s) disclosed herein. On the contrary, the intent is to cover all practical alternatives, modifications, and equivalents. | A stent system is provided for stenting a bifurcated vessel structure having a parent vessel and a daughter vessel. The stent system has a parent vessel stent and a daughter vessel stent. The parent vessel stent has a substantially tubular body that is configured to be deployed into the parent vessel. This body has an angular flap that is openable to extend into the daughter vessel. The daughter vessel stent has a substantially tubular body that is configured to be deployed through the flap in the parent vessel stent into the daughter vessel. The daughter vessel stent has an angled tail portion that is configured to overlap with the flap of the parent vessel stent when both stents are deployed in the vessel structure. A method of stenting using this system is also provided. | 0 |
FIELD OF THE INVENTION
This invention relates to geared rotary actuators as may be employed in a power train extending between a power drive unit or drive motor and an element whose position is to be moved as, for example, a control surface of an aircraft.
BACKGROUND OF THE INVENTION
Systems including power trains for actuating, for example, control surfaces on aircraft, and which require geared rotary actuators typically require high capacity overtravel stops. Such stops prevent system components from moving past positions defining the ends of a path of travel as a result of inertial loading within the system. In the usual case, most inertial energy in the system is located at the drive motor in the power drive unit. Consequently, the preferred location for a stop mechanism is remote from the motor so that shafting between the motor and the stops can provide a soft, spring-like action when the stops are engaged. In aircraft, this means that the stop mechanism should be located very close to the geared rotary actuator which in turn is in close proximity to the control surface to be moved. And, as in all aircraft situations, it is desirable that the system be light in weight as well as of small bulk and of minimal complexity to minimize cost and enhance reliability.
The present invention is directed to the provision that a geared rotary actuator incorporating an internal stop mechanism to achieve minimal cost, weight, bulk and complexity.
SUMMARY OF THE INVENTION
It is the principal object of the invention to provide a new and improved geared rotary actuator. More particularly, it is an object of the invention to provide a geared rotary actuator that incorporates an internal stop mechanism.
An exemplary embodiment of the invention achieves the foregoing objects in a geared rotary actuator which includes a housing adapted to be fixed to another structure, a rotatable input shaft journalled by the housing, an output shaft journalled by the housing and means including at least one gear rotatable within the housing coupling the input and output shafts. First and second stop elements are provided. One is carried by the input shaft and the other by the housing and the two are relatively movable into and out of an interference relation halting rotation of the input shaft in at least one, and preferably, both directions. Means are provided which include a lost motion connection between the gear and one of the stop elements for causing movement of the one stop element into the interference relation only upon predetermined rotation of the gear indicating that an overtravel position is being approached.
In a preferred embodiment, the first and second stop elements define a second lost motion connection. This allows axial movement of stop elements only during overtravel and provides the necessary dwell required by the geared rotary actuator.
In a highly preferred embodiment, the gear is a planet gear mounted for epicyclic movement within the housing toward and away from the overtravel position. The gear thus readily serves as a timing means for timing operation of the stop mechanism while maintaining its traditional function of coupling the input and output shafts.
The invention contemplates the provision of a mechanical sensor for sensing when the gear is rotated close to an overtravel position along with an actuator responsive to the sensor for moving one of the stop elements into interference relation with the other stop element.
In a preferred embodiment, a first ring-like element is located within the housing and the sensor is a formation on the ring-like element which is engageable with the gear when the gear is rotated close to the overtravel position. The actuator comprises a cam surface on the ring-like element which is operable to cam the second stop element into the interfering relation with the first stop element.
The invention contemplates that the first ring-like element be rotatable within the housing.
According to the invention, the second stop element includes a cam follower that is engageable with the cam surface. Means are provided to bias the second stop element away from the interfering relation as well as to bias the cam follower towards the cam surface.
According to a preferred embodiment, the second stop element is a ring-like element concentric with the input shaft and mounted within the housing for axial movement toward and away from the interfering relation and fixed within the housing against rotation relative thereto.
Preferably, a projection is mounted on the second ring-like element for interfering engagement with the first stop element and there is further provided a cam surface on the second ring-like element which is engageable with the first stop element for camming the second stop element away from the interfering relation when the gear is moving away from the overtravel position.
Other objects and advantages will become apparent from the following specification taken in connection with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially sectional, partially schematic view of a system including geared rotary actuator including an internal stop mechanism made according to the invention and with the internal stops disengaged;
FIG. 2 is a fragmentary sectional view illustrating the stops in an engaged position;
FIG. 3 is a developed view of a mechanical sensor and associated cam surface and taken generally in the direction indicated by the line 3--3 in FIG. 1;
FIG. 4 is a sectional view taken approximately along the line 4--4 in FIG. 1; and
FIG. 5 is a developed view illustrating that portion of the mechanism encompassed by the line 5--5 in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An exemplary embodiment of a geared rotary actuator with an internal stop mechanism is illustrated in the drawings and will be described herein in the environment of an aircraft, and its use in controlling the position of a control surface thereon. However, it is to be understood that the invention is not limited thereto, but may be employed with efficacy in any instance where a geared rotary actuator with overtravel stops is required.
Referring to FIG. 1, a remote drive motor or power drive unit (PDU) 10 is connected by shafting shown schematically at 12 to an input shaft 14 of the geared rotary actuator. Bearings 16 journal the shaft 14 for rotation within a housing 18 assembled to a geared rotary actuator gear part 19. The gear part 19 includes a mounting flange 20 by which it may be mounted to another structure such as part of an aircraft frame or the like.
As alluded to previously, the system includes an output arm 22 which may be connected to a control surface 24 or the like on an aircraft (not shown) for moving the same between any of a variety of positions. The output arm 22 is appropriately connected to an output ring gear 26 which is journalled as by bearings 28 and a pilot 29 to the gear part 19 to be coaxial with the shaft 14.
Within the gear part 19, a sleeve 30 is mounted to the shaft 14 for rotation therewith by means of interengaging splines 32. A set of interengaging splines 34 between the sleeve 30 and a sun gear 36 is also provided so that the sun gear is coaxial with and rotates with the shaft 14.
Teeth 38 on the sun gear 36 (which are only fragmentarily shown) are in engagement with teeth 40 of a plurality of planet gears 42 which are also within the gear part 19. The teeth 40 of the planet gears 42 are meshed with teeth 44 on the ring gear 26 as well as with stationary ring gear teeth 46 on the interior of the gear part 19. It will thus be appreciated that upon rotation of the shaft 14, the sun gear 36 will rotate and drive the planet gears 42. By reason of the fact that the planet gears are meshed with the fixed or stationary ring gear defined by the teeth 46, the planet gears 42 will undergo epicyclic movement within the housing and at the same time, will drive the output ring gear 26.
One of the planet gears 42, on its rotational axis 50, carries an axially projecting pin 52 which serves as a mechanical actuator. The pin 52 will, of course, track around the path of epicyclic movement of its associated planet gear 42 within the gear part 19 and thus serves as an indicator of the amount of rotary motion that has been outputted by the actuator via the ring gear 26, and the arm 22 to the control surface 24. In short, the position of the pin 52 is taken as an indication of how closely an overtravel position of the control surface 24 is being approached in either direction of rotation.
It will thus be appreciated that the gear system within actuator not only provides the usual power transmission function, but the same advantageously acts, as will be seen, as a timing means for operation of the stop mechanisms. Because the pin 52 and its indicating function are related to an element that undergoes epicyclic rotation rather than simple rotation about a fixed axis, a large number of revolutions of the input shaft 14 may be accommodated without the pin moving more than once to or through a position indicative of the approach of the overtravel position. This feature allows elimination of timing gearing in stop mechanisms heretofore employed, which timing gearing was in addition to the power transmission gearing, thereby reducing both weight and bulk.
Within the housing 18 is a first ring-like element 60. The first ring-like element 60 is disposed within a second ring-like element 62 which in turn is splined as by interengaging splines 64 to the gear part 19. In other words, the second ring-like element 62 may move axially within the gear part 19, but is prevented from rotating relative thereto. In contrast, no such limitation is imposed upon the first ring-like element 60 which may rotate freely within the second ring-like element 62 about the axis of the shaft 14.
As seen in FIG. 3, which is a partial developed view of the ring-like element 60, on its right hand side, it includes an axial projection 66. As can be seen in FIGS. 1 and 2, the projection 66 is radially spaced from the centerline of the shaft 14 approximately the same distance as the pin 52. Consequently, as the planet gear 42 carrying the pin 52 moves to a position closely approaching the overtravel position, the pin 52 will engage the projection 66 and rotate the first ring-like element 60.
On the side of the first ring-like element 60 opposite from the projection 64, a cam surface 68 is located. Note that the cam surface 68 includes a flat dwell section 69 for purposes to be seen. A pair of pins 70 that are directed radially are carried by the second ring-like element 62 and mount rollers 72 which engage the cam surface 68 and thus serve as cam followers. Thus, it can be appreciated from a consideration of FIG. 3 that rotation of the first ring-like element 60 as a result of contact between the pin 52 and the projection 66 will cause the second ring-like element 62 to be cammed to the left as viewed in FIGS. 1 and 2.
The second ring-like element 62, as seen in all but FIG. 3, carries a pair of axially directed stop elements 80 which are angularly spaced from one another by 180° and is concentric about the shaft 14. At the same time, the input shaft 14 includes a pair of radially projecting stops 82 which are also angularly spaced by 180°.
When the second ring-like element 62 is cammed to the left as viewed in FIGS. 1 and 2 as a result of the pin 52 engaging the projection 66 and the cam surface 68 operating against the roller 72, the stop elements 80 will be moved from the position illustrated in FIG. 1 to that illustrated in FIG. 2 which is into blocking relation or interfering relation with the stops 82. Because the second ring-like element 62 cannot rotate as a result of the restraint inherent in the use of the spline 64, further rotation of the shaft 14 in the direction that brought about engagement in the first place will be halted, thereby providing an overtravel stop. Reverse rotation of the shaft 14 will result in similar stopping action at the other end of the path of movement of the control surface 24.
The system is essentially completed by the presence of second cam surfaces 84 between the projections 80. Those skilled in the art will appreciate that the positive slope of the cam surfaces 84 will result in engagement of the cam surface 84 with the axially projecting stops 82 carried by the shaft 14 to cam the second ring-like element 62 to the right to ensure positive disengagement of the stops notwithstanding any tendency not to move in such direction as a result of wear, binding or corrosion.
Further, to assure such movement and prevent inadvertent stop engagement, a compression coil spring 88 is also disposed within the housing to act against the radially outer ends of the pins 70 and bias the second ring-like element 62 away from the path of movement of the radial projections 82 on the shaft 14.
An important feature of the invention is the fact that the orientation of the pin 52 and its association with a planet gear 42 in relation to the projection 66 establishes a first lost motion connection which provides a certain amount of the dwell required for the proper motion of the geared rotary actuator system. A second lost motion occurs between the roller 72 and the cam 68 as a result of the dwell section 69. In effect, a third lost motion connection is established by the relationship of the axial projections 80 on the second ring-like formation 62 and the radial projections 82 carried by the shaft 14 for the same purpose. Thus, sufficient lost motion is available to ensure that axial movement of the stops will occur only during overtravel.
The use of the cam surface 84 ensures proper disengagement of the stops when the actuator input reversed direction away from the stops position.
A number of additional advantages also accrue. As mentioned previously, the geared rotary actuator of the invention eliminates timing gears heretofore used in timing operation of a stop mechanism. It further minimizes cost and weight through the use of the ring gear teeth 46 as part of the interengaging splines 64 as can be appreciated from a consideration of FIGS. 1 and 2. The mounting flange 20 also provides additional weight and cost advantages by grounding both the gear rotary actuator and the stop mechanism.
The mechanism does not require additional bearings as might be required where the stop mechanism is separate from the geared rotary actuator. It will also be appreciated by incorporating the stop mechanism into the geared rotary actuator, a compact, low weight, high capacity stop mechanism has resulted which is simple to rig and which may be readily associated with an electrical sensor such as a switch or the like to sense stop engagement at both ends of the travel. | Weight and complexity concerns in geared rotary actuators and stop mechanisms for aircraft or the like may be minimized in the structure including a housing (18) adapted to be fixed to another structure, a rotatable input shaft (14) journalled by the housing (18), an output shaft (22, 28) journalled by the housing and a coupling between the input shaft (14) and the output shaft (22, 28) including at least one rotatable gear (42). The system includes a mechanical sensor (66) for sensing when the gear (42) has rotated close to an overtravel position and a first stop element (82) is associated with the input shaft (14) to be rotatable therewith. A second stop element (80) is movable into interfering relation with the first stop element (82) to stop rotation thereof and is carried by a gear part (19). Also included is an actuator (60, 62, 68, 70, 72) responsive to the sensor (66) for moving the second stop element (80). | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to structures for filling with water for damming water courses, controlling and directing water flow, for damming between walls and support structures, and providing for end to end connection of structures to extend across an area to be dammed, and the like, and includes sleeves for containing water containing bladders, where the damming structure is inexpensive to construct, erect, and dismantle.
[0003] 2. Prior Art
[0004] A need for easily installable and versatile damming structures, and the like, particularly structures that are filled with water, that are relatively inexpensive, non-permanent, reusable and are durable have been recognized by the inventor who has been awarded a number of U.S. Patents for forming and joining water structures together, forming hydraulic damming structures Such water structures have been found to be very useful for safely and reliably containing water, for directing water, are also useful for controlling hazardous waste, oil or chemical spills, for flood control, and the like. Further, such water structures are also useful, for example, for temporary damming operations such as maybe involved in agricultural water storage, construction, for de-watering work sites and fields, to protect buildings against flooding, and the like, and are even appropriate for use as permanent or long term structures.
[0005] Heretofore it has been recognized that fluid filled flexible water control structures and barriers can, if formed to resist movement, be used for retention and storage of water, control of water flow and wave action, and a number of configurations of dams and barriers have been arranged as both semi-permanent and temporary structures. Such earlier patents, however, do not show a combination of a flexible sleeve that is configured with finger ends, where the sleeves can be fitted and maintained together to form a continuous damming structure, or where the finger ends can be fitted into a door way or against a wall end to span that door way or wall. In practice, with the filling of a bladder or bladders within the sleeve or sleeves, a secure dam is formed across an area to be de-watered, across a door way, or to extend outwardly from a wall end.
[0006] Where earlier continuous damming sleeve and bladder structures have been arranged across an area to be dammed or de-watered, such have generally included pairs of sleeve with bladders that are braced against a pier structure, or have employed an outer sleeve to discourage the individual sleeves and filled bladders from rolling apart responsive to the weight of water or wave action directed against the damming structure, or have utilized other arrangements for keeping the sleeves with water filled bladders from moving. Unique to the invention, the sleeve fingers can be joined together, as by lacing them together along common edges, to discourage sleeve movement, can be joined around a fixed pole, or the like.
[0007] Summarizing, before the invention, no prior art structure has provided a barrier arrangement or arrangements of barriers were the sleeve ends have fingers can function, as set out above, to provide a versatile damming structure to meet a variety of needs as the invention can be used for.
SUMMARY OF THE INVENTION
[0008] It is a principal object of the present invention to provide a damming structure that includes at least one flexible sleeve for containing a bladder or bladders for filling with water, where each bladder includes a filling arrangement and an air drain, where the sleeve ends are notched, forming a U shape that the bladder or bladder ends fit into, with the sleeve notches to fit along opposite sides of the edge of a doorway or wall, providing, with the bladder or bladders filled with water, a barrier across a doorway or extending outwardly from a wall, and which sleeve notched ends can be fitted and maintained together, in end to end relationship, forming a barrier across an area to be de-watered or protected from flood waters.
[0009] Another object of the present invention is to provide the sleeve ends from the notches with flat parallel top and bottom surfaces or can have a taper in the top from adjacent to, or forward from, the notch, to the finger end to facilitate positioning of the sleeve finger ends containing the bladder ends across a door way or wall, and for, with blunt sleeve finger ends fitted together , will provide approximately a uniform height or the dam across the notches junction.
[0010] Another object of the present invention is to provide sleeves having ends that, from the notch, can be fitted around or across a fixed structure such as a door way, wall, post, or the like, where the sleeve notch fingers can be joined, as by lacing through spaced holes formed along the fingers edges to fix the sleeve ends in place, whereafter the bladders in the sleeve are filled with water to provide a barrier to water.
[0011] Still another object of the present invention is to provide for; conveniently filling each bladder with water to erect the structure as a water barrier; venting air from between the bladder and sleeve during filling; and for conveniently draining which bladder to deflate the barrier when it is no longer needed.
[0012] Still another object of the present invention is to provide a portable damming structure that is easily transported and erected to protect a building against flooding; to prohibit flooding of an area or for de-watering a flooded area, that is easily deflated and removed after the flood danger has subsided.
[0013] Principal features of the invention include at least one sleeve that is formed from a strong, woven polypropylene material, such as GeoTex®, or like material, to provide that is puncture resistant and has a tear strength that is sufficient to maintaining the forces exerted thereon when functioning as a damming structure, and the sleeve is to receive at least one bladder preferably formed from a lightweight polyethylene material that is capable of be filled with water to its capacity without rupturing, that includes a filing tube and air drain, and which sleeve includes a notched section in each end, between fingers, forming a U shape. Where the fingers extend parallel and each receives a bladder end fitted therein to receive water, forming a damming structure, and provides for venting air from the finger ends during bladder filling. In practice the sleeve notched ends can each be fitted across opposite sides of a pair of wall ends or sides of a door opening, straddling that wall end or door way. So arranged, the sleeve bladder or bladders, when filled with water, provide a damming structure between the wall ends or across the doorway that prohibits flood waters from passing thereacross.
[0014] The fingers top surface may be sloped relative to the finger bottom surface from the notch to the finger ends for fitting the finger along opposite sides of a doorway or wall sides, or may not be sloped, having blunt ends where the ends are essentially at right angles to the finger top and bottom surfaces, allowing the sleeve to be positioned together at their notches, with the fingers positioned alongside one another and can be joined together, as by lacing through holes, that are preferably reinforced, forming grommets, where the holes are formed at spaced interval along he fingers edges, whereby the height of the joined sleeves at the junction will be essentially the same height as that of the filled sleeves. Additionally, the fingers ends can be joined around a pier or post and secured together, as by lacing, with the pier or post therebetween, providing an anchor for holding the sleeves in place.
[0015] In practice a strong flexible sleeve formed from GeoTex®, a material manufactured by Propex Operating Company, LLC, and bladder formed from a lightweight polyethylene plastic, or the like, is selected to provide a bladder that, when filled with water, is strong enough to resist punctures and the bladder ends that fit into the sleeve finger ends preferably has a wall thickness of from (5) to (12) millimeters has been used successfully for installation in the fabric sleeve of the invention. Though, it should be understood, the invention is not limited to any particular sleeve or bladder manufacture or thickness; can utilize sleeves and/or bladders of greater or lesser wall thickness; and the sleeve notch ends can be connected by lacing a cable through grommets, or by other connection arrangement, for maintaining the sleeves fingers together, within the scope of this disclosure.
DESCRIPTION OF THE DRAWINGS
[0016] In the drawings which illustrate that which is presently regarded as the best mode for carrying out the invention:
[0017] FIG. 1 is a top plan view of a water containment structure with finger ends of the invention that is shown as a sleeve with end notches forming like fingers that can be fitted across a wall or doorway, and showing the sleeve as containing a pair of bladders or closed end tubes whose ends are fitted into the finger ends and showing, in broken lines each bladder or closed end tube as including a fill tube and air drain that extend out from each bladder or tube;
[0018] FIG. 2 is an end view of the sleeve and with finger ends, less the wall or doorway, showing the sleeve seam that extends around the sleeve mid-section, showing the seam formed from upper and lower sections joined at a seam, and showing the finger ends as including a pair of air vents;
[0019] FIG. 3 shows a side elevation view of the sleeve of FIG. 2 , showing the slope of one of the sleeve slanted finger ends as angle C, with the other sleeve finger ends being identical thereto, and showing, in broken lines, the end of the sleeve notch;
[0020] FIG. 4 is an end perspective view of the sleeve showing the sleeve as formed from top and bottom sections of material that are secured together, as by stitching the edges of the sections together, showing the bladders in broken lines, and showing in broken lines, a pair of fill tubes for filling the bladders with water, with the fill ends thereof shown as extending out from the sleeve, and showing bladders air vents adjacent to the fill tubes ends, and showing the pair of finger ends air vents, as are shown also in FIGS. 1 , 2 and 3 ;
[0021] FIG. 4A is an exploded end sectional perspective view taken from a notched end of the sleeve that shows aligned spaced eyelets that have metal rings fitted therein, forming grommets, formed along the edge of each sleeve fingers and notch and shows a cable threaded through the spaced eyelets for lacing the finger ends together forming a damming structure like that is shown in FIGS. 6 and 8 ;
[0022] FIG. 5 is a view like that of FIG. 4 only showing the sleeve notches as positioned between vertical posts, and the bladders as having been filled with water, and illustrating which filling of the bladders with water with water by arrows A, and illustrating, with arrows B, the venting of air from the bladders through the air drains during which water filling;
[0023] FIG. 6 shows sleeves like those of FIGS. 1 through 5 , except, it should be understood, the fingers have blunt ends, and are connected end to end at their notched ends with the adjacent sleeve fingers shown connected together along common edges, forming a continuous damming structure;
[0024] FIG. 7 shows an end sectional view taken along the line 7 - 7 of FIG. 6 showing the damming structure of FIG. 6 as holding back a weight of water on one side, and shows an adjacent section of the damming structure of FIG. 6 ; and
[0025] FIG. 8 shows a damming structure like that of FIG. 7 , except the damming structure is shown formed into an arc.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Temporary water structures that are erected at a location to be de-watered, to protect an area or structure from anticipated flooding, and are in common use. Such temporary structures have included flexible sleeves containing bladders or closed end tubes for positioning at a site to be dammed, with the bladders then filled with water to erect the damming structure. Such water structures have, however, lacked versatility in that none have provided convenient arrangements for joining sleeves together in an end to end relationship. Further, earlier temporary water structures have needed to included at least an arrangement of two bladders in a single sleeve along with an anchoring structure to provide a dam that would resist side ways movement or rolling from water forces exerted onto one side of the sleeve, or have required that a pair of sleeves with tubes or bladders in each that have then been contained in an outer sleeve to resist rolling movement where lateral forces were exerted against the dam. Whereas, the invention provides a sleeve with U shaped notch ends, forming parallel fingers, where the fingers can be sloped to fit and be conveniently maintained across a door way or wall end, where the fingers can be joined together around a post, or the like, for holding the sleeve, or a plurality of sleeve having blunt ends that are approximately the height of the sleeve body can be joined end to end by fitting sleeve fingers together to their notched ends to form a damming structure that will resist movement.
[0027] FIG. 1 shows a top plan view of a water containment structure with finger ends 10 of the invention, hereinafter referred to as damming structure. Shown therein, the damming structure 10 includes a sleeve 11 having parallel fingers 12 with a notch 13 there between formed on opposite sleeve ends. The sleeve 11 is shown as including a pair of bladders 14 a and 14 a that, it should be understood, can be tubes that are closed at their ends. Which bladders 14 a and 14 b extend the length of the sleeve, in parallel relationship, and into, the finger ends 13 . Each bladder 14 a and 14 b includes a fill tube 15 a and 15 b, that has a nozzle end 16 a and 16 b that extends out of the sleeve for filling the individual bladders with water, and each bladder 14 a and 14 b includes an air drain 17 a and 17 b that extends from the bladder and extends through the sleeve to vent air from the bladder as it is filled with water. Where a pair of bladders 14 a and 14 b is shown, it should be understood that a single bladder, formed to fit within the sleeve 11 and into the fingers 12 , that includes a fill tube and air vent could be used in the invention within the scope of this disclosure. Additionally, air vents 18 are provided in the end of each sleeve finger of at least one end of the sleeve to facilitate venting air from the sleeve ahead of the bladder when the bladder is being filled with water through the fill tube, which air vents allow the bladder to fully fill the sleeve and sleeve finger ends.
[0028] FIG. 1 shows the damming structure 10 fingers 12 fitted across an end of a structure 20 , with the sleeve notch 13 in engagement with the structure end 20 . This arrangement of the damming structure 10 illustrates it's use to protect an area across the structure ends 20 that can be a door way, an area behind two walls, or the like. To facilitate fitting which fingers 12 across a door way or between wall ends, as shown in FIGS. 2 and 3 , the fingers 12 are slopped at like slants from adjacent to or just forward of the notch 13 to each finger 12 end. Which slope is shown as angle C in FIG. 3 , and, it should be understood, can vary depending upon the use as the damming structure 10 is use for. In practice, for fitting the sleeve fingers across a doorway or wall end, such slope is selected from where the finger top and bottom surfaces are nearly parallel for, for joining the sleeve ends together to form a continuous damming structure, the ends of the fingers will be essentially at right angles to the finger top and bottom surfaces and, accordingly, the slope angle C can be from essentially (0) zero to (90) degrees, within the scope of this disclosure. Such finger slant facilitates the fitting of the fingers across the door way or wall end to the notch 13 where the fingers 12 extend along the opposite sides of the doorway or wall ends 20 , is selected to provide a narrowing area within the bladder 14 a and 14 b fitted into the finger ends 12 while allowing for and encouraging the exhausting of air from the space in-between which bladder outer surface and fingers inner surfaces that is vented out from the air vents 18 .
[0029] Also shown in FIGS. 2 and 3 , the sleeve 11 is preferably formed from a pair of like sections of sleeve material which, in practice, that is preferably a strong, woven polypropylene geotextile type material that provides strength and is puncture resistance, and a GeoTex® flexible fabric material manufactured by Porpex Operating Company, LLC that is resistive to tearing even when it is pulled over rough terrain, has been used as the damming structure 10 . Though, it should be understood, other materials may be so utilized within the scope of this disclosure. In practice, the sections of material are formed as upper and lower sections that are laid out over one another and are secured together along their common edges 11 a , as shown in FIGS. 4 and 5 , as by sewing, riveting, welding, or by other appropriate method, and spaced holes 25 are shown formed along the edges at the edges 11 a of the sleeve 11 a ends, as shown also in FIG. 4A . Which holes are preferably strengthened against tearing by fitted each with a metal ring, or the like, forming a grommet, and a rope, cable, lace 25 a, or the like, is fitted through a first hole 25 and is laced through the adjacent aligned holes 25 for releasably joining the finger 12 ends together, as illustrated in FIGS. 6 and 8 , as discussed below. Before or during which manufacture, the bladders 14 a and 14 b, that are preferably formed from a lightweight polyethylene mater, or like material, that are arranged in the sleeve 11 prior to closure of the sections of the sleeve material along common edges 11 a . In practice, a polyethylene material that has a thickness of from five (5) to twelve (12) millimeters has been used as the bladders 14 a and 14 b. Which bladders thickness is selected for the liner size as is required to fill the sleeve 11 .
[0030] During the forming of the sleeve 11 of the damming structure 10 , as shown in FIG. 4 , the bladder fill tubes 15 a and 15 b are installed into the bladder 14 a and 14 b and the fill tubes nozzle ends 16 a and 16 b are passed through the sleeve 11 , as the bladder air drains 17 a and 17 b that are fitted into the bladder 11 and mounted to the sleeve 11 completing the manufacture of he damming structure 10 , that can be moved to a site and filled with water.
[0031] FIG. 4A shows the end edges 11 a of the sleeve 11 that, as shown in FIGS. 1 , 4 and 5 , that has been joined together and shows spaced holes 25 that, preferably have each been fitted with a reinforcing ring, forming a grommet, and shows the lace 25 a laced through holes 25 on one side of the sleeve 11 end for connecting, end to end, finger 12 ends of sleeves, as shown in FIGS. 6 and 8 , or connecting the finger 12 ends around an anchor, as shown in FIG. 5 . The edges 11 a of the sleeve 11 ends are shown in FIG. 5 positioned around poles 30 , and the bladders 14 a and 14 b are shown as having been filled with water, forming an erected damming structure 10 supported between which poles 30 . To further anchor the damming structure of FIG. 5 , the ends of fingers 12 of each sleeve 11 end can be wrapped around each pole 30 such that and the sleeve 11 edges 11 a come together and the spaced holes 25 align to receive the lace 25 a laced through the spaced holes 25 to maintain the fingers 12 ends together, locking the sleeve ends together,
[0032] FIG. 6 shows a linking, end to end, of a plurality of sleeves 11 to form damming structure 10 that extends across an area to be dammed, as for de-watering, or the like. Which arrangement of sleeves involves fitting a sleeve 11 finger end 12 of one sleeve to a notch 13 of a next sleeve 11 such that the fingers 12 of the two sleeves 11 fit side by side and their edges 11 a over lapping to align the individual spaced holes 25 , as illustrated in FIG. 4A , to receive a lace 25 a that is laced through each pair of aligned holes 25 , across along a first and second finger 12 sides, across a finger 12 end, across a notch 13 , and along the first and second finger 12 sides and shows the lace ends knotted to prohibit back passage through the holes 25 , securing the coupling of the sleeves 11 ends together that then receive water through fill tubes to fill the sleeves, forming damming structure 10 , as shown in the sectional view of FIG. 7 . Which sectional view of FIG. 7 shows a cross sectional view of one sleeve 11 with a pair of water bladders 14 a and 14 b therein, and shows the outer surface of an adjacent sleeve 11 as having also been filled with water, forming the damming structure 10 that, as shown, is holding back a level of water 30 , which sleeves 11 and fingers 12 , it should be understood, have a same height to provide, when joined end to end, a constant height of damming structure 10 .
[0033] FIG. 8 also shows a damming structure 10 formed with sleeves 11 fitted together, end to end, where, like the damming structure 10 of FIG. 6 , the finger ends 12 and notches 13 are connected together, only, the damming structure of FIG. 8 is shown arranged in an arc and is maintained between wall ends 20 , like the single sleeve 11 arrangement shown in FIG. 1 . Which damming structure 10 arrangements of FIGS. 1 , 6 and 8 , illustrate the variety of applications the sleeve 11 with fingers 12 and notch 13 ends can be used for to form damming structures. In forming which damming structures 10 shown in FIGS. 6 and 8 , the slope of the fingers 12 top surface from approximately the notch 13 to the finger 12 end of each finger, when the fingers are positioned side by side provides, a damming structure whose profile is essentially uniform along its length, as shown in FIGS. 6 and 8 .
[0034] While not shown, it should be understood that the sections of material forming sleeve 11 could be secured together along their junctions as with a zipper, or the like, to allow access to the bladders 14 a and 14 a, and that, within the scope of this disclosure, a single bladder or closed tube can be formed to have ends arranged to fit into the sleeve fingers 12 , to the ends thereof.
[0035] The water structures 10 , as illustrated in FIGS. 1 and 5 through 8 , represent damming structures that will, when erected, hold back a body of or flow of water. In holding back such body of water, as when the wind passes over such body of water, wave actions may be created that tend to move the damming structure. Earlier temporary damming structures have met this problem by containing two or three water filled vessels within an outer sleeve to discourage a wave action from causing rolling the damming structure, and other arrangement have utilized anchors, or the like. The invention, as set out above, by connecting the sleeve finger ends across or around a fixed structure, as illustrated in FIGS. 1 and 5 , provides for fitting and securing sleeve finger ends around an anchoring for prohibiting movement, and provides for joining of one sleeve finger ends into the finger ends of a second sleeve, such that the outside surface of the finger end is apart from the sleeve, to function like an outrigger, discouraging rolling of the damming structure 10 that extends across a section of land to be protected or de-watered, as shown in FIG. 6 , and shows, in FIG. 8 , such damming structure 10 as having been anchored between fixed walls, also discouraging the damming structure from moving or rolling even when the damming structure holds back a level of water that is being subjected to wind forces.
[0036] The invention is a use of a sleeve or sleeves formed of a strong, puncture resistive and durable material such as GeoTex® manufactures by Propex Operating Company, LLC, has been used in practice, through, it should be understood another like material could be so used within the scope of this disclosure. The sleeve or sleeves are to receive one or more bladders or tube or tubes whose ends have been closed to receive water filling the bladder or closed tube are preferably formed from a material, such as a flexible polyethylene plastic, that is strong enough to resist punctures and has a range of wall thicknesses of five (5) to twelve (12) millimeters, through, it should be understood bladders or tubes having greater or less thickness could be used within the scope of this invention depending upon the sleeve size, and it should, therefore, be understood, the invention is not limited to any particular sleeve material or bladder of close tube material or to a particular wall thickness of sleeve material or bladder or closed tube and that other appropriate sleeve materials or bladder or close tubes can be used within the scope of this disclosure.
[0037] Although preferred embodiments of the invention have been shown and described herein, it should be understood that the present disclosure is made by way of example only and that variations are possible, within the scope of this disclosure, without departing from the subject matter coming within the scope of the following claims and reasonable equivalency thereof, which claims I regard as my invention. | A water containment structure with finger ends that includes at least one sleeve formed from a strong flexible material that will resist puncturing that is formed to receive at least one bladder formed to retain water, and which said sleeve includes center notches formed in the opposite sleeve ends that separate like closed end fingers, with which bladder fills the sleeve such that the ends fit against the finger ends, and at least one water fill tube and an air drain are fitted through said sleeve to pass, respectively, water into which bladder to fill same, with the air drain to provide for evacuating air from the sleeve during bladder filling. Which sleeve finger ends sloped, as needed, and can be fastened together around a support or can be secured to one another for connecting a number of sleeves, end to end, into a damming structure. | 4 |
PRIORITY
[0001] This application is a continuation of U.S. patent application Ser. No. 09/712,867, filed Nov. 15, 2000, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention.
[0003] The present invention relates to headsets and, more particularly, to a headset and method of manufacturing headsets that utilize a single transceiver form-factor design with a number of different housing styles.
[0004] 2. Description of the Related Art.
[0005] A headset is a device that, when worn by a user, positions a speaker next to the user's ear and a microphone next to the user's mouth. The headset, which allows hands-free operation, is commonly worn by telephone operators and is increasingly being worn by personal computer users for telephony over the internet, gaming, and speech recognition. In addition, more and more cell phone users are utilizing headsets.
[0006] [0006]FIG. 1 shows a perspective view that illustrates a prior-art headset 100 . As shown in FIG. 1, headset 100 has an elongated support member 110 , a speaker 112 which is connected to one end of support member 110 , and a microphone 114 which is connected to the opposite end of support member 110 .
[0007] Further, headset 100 has a positioning member 116 that is connected to support member 110 . Positioning member 116 , which is designed to be worn over the ear, has a first section that is connected to member 110 , a second angled section that is connected to the first section, and an arcuate-shaped third section that is connected to the second section.
[0008] In addition to the ear-type headset shown in FIG. 1, headsets are also commonly available that use a headband to hold the support member, and thereby the speaker and microphone, in place. With a headband support member, the speaker is placed over one ear with the headband extending over and contacting the head with a padded end that the rests above the opposite ear.
[0009] Another common type of headset, sometimes referred to as soap-on-a-rope, utilizes a speaker which is placed in or next to the ear, and a microphone which is located somewhere on the wire that connects the speaker to a telephone or computer. Although this soap-on-a-rope type headset is very compact and easy to transport, the location of the microphone, which is often clipped to the user's clothing, is susceptible to excessive background noise.
SUMMARY OF THE INVENTION
[0010] The present invention provides a method of manufacturing headsets that utilizes a single transceiver form-factor design with a number of housing styles. By utilizing a single transceiver form-factor with a number of housing styles, development costs, manufacturing costs, and time to market are reduced while at the same time providing a wider variety of choices to the consumer. In addition, after buying the first headset, the consumer can purchase additional housings without purchasing additional transceivers as the transceiver from the first headset can be used in whatever housing the consumer desires to wear.
[0011] The method of the present invention includes the step of forming a plurality of substantially identical transceivers. Each transceiver has a body, a speaker transducer connected to the body that outputs sound in response to a sound signal, and a microphone transducer connected to the body that outputs an electrical speech signal in response to input sound. The method also includes the step of forming a number of housings with different housing styles. The method further includes the step of attaching the substantially identical transceivers to the housings so that transceivers are attached to different housing styles. This, in turn, allows different headsets to be built with different outer shapes, all using the same transceiver design.
[0012] The method of the present invention may also include the steps of displaying the housing styles to a user population, and receiving an order from a user. The order identifies a style of housing selected by the user.
[0013] The method of the present invention produces a collection of headsets that include a number of first and second housings. The first and second housings each have an inner cavity. The collection of headsets also includes a number of substantially-identical transceivers. The transceivers are positioned within the inner cavity of each first housing and the inner cavity of each second housing.
[0014] A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description and accompanying drawings that set forth an illustrative embodiment in which the principles of the invention are utilized.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 is a perspective view illustrating a prior-art headset 100 .
[0016] [0016]FIG. 2 is a flow chart illustrating a method 200 for manufacturing headsets in accordance with the present invention.
[0017] [0017]FIG. 3 is a block diagram illustrating a transceiver 300 in accordance with the present invention.
[0018] [0018]FIGS. 4A and 4B are opposing perspective views of a transceiver 400 illustrating a first example of a form factor in accordance with the present invention.
[0019] [0019]FIGS. 5A and 5B are opposing perspective views of a transceiver 500 illustrating a second example of a form factor in accordance with the present invention.
[0020] [0020]FIGS. 6A and 6B are perspective views of a housing 600 illustrating a first example of a housing style in accordance with the present invention.
[0021] [0021]FIG. 7 is a perspective view of a housing 700 illustrating a second example of a housing style in accordance with the present invention.
[0022] [0022]FIGS. 8A and 8B are perspective views of a housing 800 illustrating a third example of a housing style in accordance with the present invention.
[0023] [0023]FIG. 9 is a perspective view of a housing 900 illustrating a fourth example of a housing style in accordance with the present invention.
[0024] [0024]FIG. 10 is a perspective view of a housing 1000 illustrating a fifth example of a housing style in accordance with the present invention.
[0025] [0025]FIG. 11 is a perspective view illustrating a first retaining structure 1100 in accordance with the present invention.
[0026] [0026]FIG. 12 is a perspective view illustrating a second retaining structure 1200 in accordance with the present invention.
[0027] [0027]FIG. 13 is a side view illustrating a third retaining structure 1300 in accordance with the present invention.
[0028] [0028]FIG. 14 is a perspective view of a headset 1400 illustrating the use of retaining structure (clip) 1300 in accordance with the present invention.
[0029] [0029]FIG. 15 is a flow chart illustrating a method 1500 for manufacturing headsets in accordance with the present invention.
DETAILED DESCRIPTION
[0030] [0030]FIG. 2 shows a flow chart that illustrates a method 200 for manufacturing headsets in accordance with the present invention. As shown in FIG. 2, method 200 includes step 210 where a number of transceivers with an identical form factor are produced. (Transceivers that are intended to have the same form factor but have slight variations due to manufacturing tolerances are considered to be identical.)
[0031] [0031]FIG. 3 shows a block diagram that illustrates a transceiver 300 in accordance with the present invention. As shown in FIG. 3, transceiver 300 includes a speaker transducer 310 that outputs sound in response to a received sound signal SS 1 , and a microphone transducer 312 that outputs an electrical speech signal SS 2 in response to received (input) sound.
[0032] In addition, as shown by dashed lines L 1 and L 2 , transceiver 300 can optionally include a signal-processing circuit 314 that is connected to the speaker and microphone transducers 310 and 312 . Signal-processing circuit 314 can perform all or a portion of the signal processing that is required to interface transducers 310 and 312 with a communication device (not shown), such as a telephone or a computer. Signal processing circuit 314 can also perform other functions such as filtering, limiting, and echo canceling.
[0033] Further, as shown by dashed lines L 3 and L 4 , transceiver 300 can optionally include a wireless transmission and reception circuit 316 that is connected to signal processing circuit 314 . Wireless transmission and reception circuit 316 transmits processed or partially processed signals from signal processing circuit 314 to the communication device, and transmits compatible signals from the communication device to signal processing circuit 314 , without the use of a connecting wire. In addition, as shown by dashed lines L 5 and L 6 , speaker transducer 310 and microphone transducer 312 can optionally be connected directly to wireless transmission and reception circuit 316 .
[0034] As noted above, the transceivers are produced to have a single form factor. Although the transceivers are produced to have a single form factor, the form factor can have any shape, such as an elongated shape, a circular shape, a square shape, or a flat laminated shape such as the shape of a shark's fin.
[0035] [0035]FIGS. 4A and 4B show opposing perspective views of a transceiver 400 that illustrates a first example of a form factor in accordance with the present invention. As shown in FIGS. 4A and 4B, transceiver 400 has an elongate body 410 with a first end and a second end. In addition, transceiver 400 also has a member 412 , which accommodates a speaker transducer, that is connected to the first end of the elongate body, and a projection 414 , which accommodates a microphone transducer, that is connected to the second end of elongate body 410 .
[0036] Elongate body 410 of transceiver 400 can be flexible or rigid such that a position of the speaker transducer with respect to the microphone transducer is changeable or fixed, respectively. In addition, when the transceiver does not have a wireless transmission and reception circuit, an external wire 416 is connected to transceiver 400 to provide a connection to the communication device (not shown).
[0037] [0037]FIGS. 5A and 5B show opposing perspective views of a transceiver 500 that illustrates a second example of a form factor in accordance with the present invention. Transceiver 500 is similar to transceiver 400 and, as a result, utilizes the same reference numerals to designate the structures that are common to both transceivers.
[0038] As shown in FIGS. 5A and 5B, transceiver 500 differs from transceiver 400 in that transceiver 500 has a projection 514 that accommodates a microphone transducer. Unlike projection 414 that extends from the side of transceiver 400 , projection 514 extends from the end of transceiver 500 along the longitudinal axis of transceiver 500 .
[0039] In addition to the above, rather than using a number of transceivers with a single form factor, a number of receivers with the same form factor can alternately be used.
[0040] Returning to FIG. 2, method 200 also includes step 212 where a number of housings with different styles are produced. (Steps 210 and 212 can be performed in any order, or at the same time.) Although the housing styles are different, each housing is designed to operate with the transducer of the present invention.
[0041] [0041]FIGS. 6A and 6B show opposing perspective views of a housing 600 that illustrates a first example of a housing style in accordance with the present invention. As shown in FIGS. 6A and 6B, housing 600 is a two-piece structure with a first half 610 that has an inner side 612 and a second half 614 that has an inner side 616 .
[0042] When first and second halves 610 and 614 are connected together, housing 600 has an elongate body with a first end and a second end. In addition, inner sides 612 and 616 define an inner cavity 618 that has a number of openings 620 at the first end and an opening 622 at the second end.
[0043] Inner cavity 618 receives a transceiver, such as transceiver 400 or 500 , while openings 620 allow sound from the speaker transducer to pass out to the external world. Opening 622 , in turn, directs sounds to the microphone transducer of the transceiver. Further, any of a number of structures, such as ear piece 624 , can be connected to housing. 600 to position housing 600 next to the ear of a user.
[0044] [0044]FIG. 7 shows a perspective view of a housing 700 that illustrates a second example of a housing style in accordance with the present invention. As shown in FIG. 7, housing 700 is also a two-piece structure with a first half 710 that has an inner side 712 and an outer side 714 , and a second half 716 that has an inner side 718 .
[0045] When first and second halves 710 and 716 are connected together, housing 700 has an elongate body with a first end and a second end that is shorter than the elongate body of housing 600 . In addition, inner sides 712 and 718 define an inner cavity 720 that has a number of openings 722 at the first end and an opening 724 in outer side 714 at the second end of first half 710 .
[0046] Inner cavity 720 receives a transceiver, such as transceiver 400 or 500 , while openings 722 allow sound from the speaker transducer to pass out to the external world. Opening 724 , in turn, directs sounds to the microphone transducer of the transceiver. Further, any of a number of structures, such as ear piece 726 , can be connected to housing 700 to position housing 700 next to the ear of a user.
[0047] [0047]FIGS. 8A and 8B show opposing perspective views of a housing 800 that illustrates a third example of a housing style in accordance with the present invention. As shown in FIGS. 8A and 8B, housing 800 is a two-piece structure with a first half 810 that has an inner side 812 and a second half 814 that has an inner side 816 .
[0048] When first and second halves 810 and 814 are connected together, housing 800 has a circular body. In addition, inner sides 812 and 816 define an inner cavity 818 that has a number of openings 820 at the center of the body and an opening 822 in the side wall.
[0049] Inner cavity 818 receives a transceiver, such as transceiver 400 or 500 , while openings 820 allow sound from the speaker transducer to pass out to the external world. Opening 822 , in turn, directs sounds to the microphone transducer of the transceiver. In addition, housing 800 optionally includes a hollow sound conducting tube 824 that is connected to opening 822 to direct sounds to the microphone transducer. Optionally, sound conducting tube 824 can be directly connected to the transceiver. Further, any of a number of structures, such as head band 826 , can be used to position housing 800 next to the ear of a user.
[0050] [0050]FIG. 9 shows a perspective view of a housing 900 that illustrates a fourth example of a housing style in accordance with the present invention. As shown in FIG. 9, housing 900 has a flexible, multi-layer laminate body 910 . In addition, housing 900 has a cutout 912 , an inner cavity 914 , a first opening 916 , and a number of second openings 918 . Cutout 912 allows housing 900 to be hung from the ear of a user, while inner cavity 914 receives a transceiver, such as transceiver 400 or 500 . Further, first opening 916 exposes the microphone transducer of the transceiver to external sounds, while second openings 918 expose the speaker transducer to the external world.
[0051] [0051]FIG. 10 shows a perspective view of a housing 1000 that illustrates a fifth example of a housing style in accordance with the present invention. As shown in FIG. 10, housing 1000 has a flexible, single-layer laminate body 1010 with a cutout 1012 that allows housing 1000 to be hung from the ear of a user.
[0052] Although five examples of housing styles have been discussed, the housings of the present invention are not limited to these five styles and may have, as noted above, any style. In addition, the housings can be partially or completely formed from a material that can be cut with a pair of scissors so that the user can cut the outer sides of the housing into whatever shape is desired. The material of the housings can include, for example, foamed plastic, thin films, fabrics, or rubber. When the material is penetratable, no sound holes are needed in the housings. Further, in addition to housings 900 and 1000 , housings 600 , 700 , and 800 can also have a cut out that allows these housings to hang from the ear of a user.
[0053] Returning to FIG. 2, method 200 also includes step 214 where the transceivers are attached to the housings having the different housing styles. A number of different retaining structures can be used to attach the transceivers to the housings. FIG. 11 shows a perspective view that illustrates a first retaining structure 1100 in accordance with the present invention.
[0054] As shown in FIG. 11, first retaining structure 1100 includes a number of side walls 1110 that are connected to the inner side 1112 of a housing, such as inner side 612 , 712 , or 812 . (Side walls 1110 need not be connected together as shown in FIG. 11.) Side walls 1110 have a height H such that when the housing is assembled, the side walls 1110 contact or nearly contact the opposing inner side of the housing. In the preferred embodiment of the present invention, side walls 1110 are integrally formed with the housings. (Partial in register side walls can optionally be formed on the inner sides of both halves of a housing.)
[0055] In this example, a transceiver is attached to the housing by inserting the transceiver into a region 1114 defined by side walls 1110 . After this, the first and second halves of the housing, such as halves 610 / 614 , 710 / 716 , or 810 / 814 , are connected together such that the inner sides of the housings along with side walls 1110 keep the transceiver in place.
[0056] [0056]FIG. 12 shows a perspective view that illustrates a second retaining structure 1200 in accordance with the present invention. As shown in FIG. 12, second retaining structure 1200 includes an end wall 1210 , three side walls 1212 and a partial side wall 1214 . Extending away from partial side wall 1214 in the same plane as partial side wall 1214 is a flexible member 1216 with a retaining clasp 1218 . Further, a microphone opening 1220 and a number of speaker openings 1222 are formed in the side walls. In the preferred embodiment of the present invention, retaining structure 1200 is integrally formed with the housings such that at least one of the walls is in common with the inner side of a housing.
[0057] In this example, a transceiver is attached to the housing by pushing flexible member 1216 away from the opposing side wall, sliding the transceiver into retaining structure 1200 , and then releasing flexible member 1216 . When flexible member 1216 is released, it returns to its original position. In its original position, retaining clasp 1218 of flexible member 1216 retains the transceiver within structure 1200 .
[0058] The advantage of retaining structure 1200 is that the transceivers can be easily inserted; either during the manufacturing process or by the user themselves. In addition, retaining structure 1200 gives the user the ability to switch a single transceiver among a number of housing styles. For example, a user may have a number of housing styles and a single transceiver. The user then has the ability to place the transceiver in the preferred housing, switch styles by switching housings whenever the mood occurs or buy new a housing.
[0059] [0059]FIG. 13 shows a side view that illustrates a third retaining structure 1300 in accordance with the present invention. As shown in FIG. 13, retaining structure 1300 is a clip with first and second legs 1310 and 1312 that are connected together via a U-shaped section 1314 . Structure 1300 , which utilizes a deformable material, is formed so that first leg 1310 contacts and exerts a force against second leg 1312 .
[0060] In this example, a transceiver is attached to the housing by connecting retaining structure (clip) 1300 to a transceiver, such as transceiver 400 or 500 . After this, legs 1310 and 1312 are spaced apart and the housing is inserted between legs 1310 and 1312 . Once the housing has been inserted, the legs are released. The legs, in turn, try to return to their original position, thereby clamping the housing between the legs. Structure 1300 offers many of the same advantages as structure 1200 in that a user can switch the transceiver among a number of different housing styles.
[0061] [0061]FIG. 14, shows a perspective view of a headset 1400 that illustrates the use of retaining structure (clip) 1300 in accordance with the present invention. As shown in FIG. 14, headset 1400 includes retaining structure 1300 , transceiver 500 which is attached to structure 1300 , and housing 1000 which is clamped by structure 1300 .
[0062] Alternately, rather than using retaining structures 1100 , 1200 , or 1300 , the transceivers can be permanently affixed to the housings. The transceivers can be permanently affixed using glue or other well-known adhesives. In addition, the clip can be part of the transceiver (or receiver if only a receiver is used), or part of the housing.
[0063] Thus, method 200 forms a plurality of housing styles with different shapes that each utilize the same transceiver form factor. By utilizing a single transceiver form-factor with a number of housing styles, development costs, manufacturing costs, and time to market are reduced while at the same time providing a wider variety of choices to the consumer.
[0064] In addition to providing the user with a wider variety of housing styles, the present invention also allows the end user to view the available styles, and order the desired style. As shown by dashed line 2 A in FIG. 2, method 200 can include step 216 where a number of housings with different housing styles are displayed to a user population. The housing styles can be displayed to the user population, for example, by utilizing a web page, a catalog, or in a traditional retail setting. In addition, method 200 includes step 218 where orders are received from the users.
[0065] The orders, in turn, identify the housing styles (and quantity) selected by the users. The orders can be received, for example, by using an interactive web page, a paper form, or in person at a retail store. Once the order is received, delivery is arranged. In a retail setting, stock on hand is sold.
[0066] In accordance with the present invention, rather than displaying the housings to the user population after the headsets have been assembled, some of the manufacturing steps can be delayed until after orders are received for the headsets.
[0067] [0067]FIG. 15 shows a flow chart that illustrates a method 1500 for manufacturing headsets in accordance with the present invention. Method 1500 is similar to method 200 and, as a result, utilizes the same reference numerals to designate the steps that are common to both methods.
[0068] As shown in FIG. 15, method 1500 is the same as method 200 up through step 212 (the formation of the housing styles), and diverges from method 200 at the next step, step 1514 , where the number of housing styles are displayed to a user population. As in method 200 , the housing styles can be displayed to the user population by utilizing a web page, a catalog, or a retail setting. In addition, method 1500 includes step 1516 where orders are received from the users. The orders, in turn, identify the housing styles (and quantity) selected by the users. The orders can be received, for example, by using an interactive web page, a paper form, or in person at a retail shop.
[0069] Next, method 1500 moves to step 1520 where method 1500 determines if assembly is to be performed by the user. If assembly is to be performed by the user, method 1500 moves to step 1522 where the user is provided with either a selected housing (if only a housing was purchased) or both a selected housing and a transceiver (if both a housing and a transceiver were purchased). If the user receives both the selected housing and a transceiver, the user assembles the headset by attaching the transceiver to the housing.
[0070] If assembly is not to be performed by the user, method 1500 moves to step 1524 where transceivers are attached to the housings based on the orders received during a previous time period. For example, every two weeks transceivers could be attached to the ordered housings to form completed headsets to satisfy the orders received during the previous two weeks. By attaching transceivers on an as-ordered basis, the costs to assemble the headsets can be more related to the headsets that are being sold. By allowing the user to finish the final assembly, the costs to assemble the headsets can be largely eliminated.
[0071] In addition to selecting a housing style, the user can also select or provide an example of an ornamentation to be formed on the selected housing. The ornamentation can include, for example, a logo, a trademark, a picture, or any design. Alternately, self-printable labels can be included with each housing sold so that the user can design their own ornamentation. Payment for the order can be received either prior to accepting the order, or following shipment of the order.
[0072] In addition, sample headsets can be displayed to the user population with some or none of the headset components being manufactured until some time after orders for the headsets have been received. For example, every two weeks headsets could be manufactured to satisfy the orders received during the previous two weeks.
[0073] It should be understood that various alternatives to the embodiment of the invention described herein may be employed in practicing the invention. Thus, it is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby. | A communications headset is disclosed which includes a lightweight ear support and a transducer assembly. The transducer assembly is connected to the ear support by a resilient clip. | 7 |
BACKGROUND OF THE INVENTION
The apparatus and method of this invention concerns the production of chopped glass strand mats, particularly multilayer strand mats.
In the production of multilayer strand mats, it has been a particularly difficult problem to obtain an even distribution of the chopped glass strands in the mat. The strands may be produced in the conventional manner, such as disclosed in U.S. Pat. No. 2,719,336, assigned to the Assignee of the instant application and incorporated herein by reference. In the disclosed method, a plurality of glass strands are received in the choppers from a creel, air flow directs the streams of glass fibers in the hood and the fibers are continuously collected in the form of a mat on a foraminous conveyor chain.
The difficulty has been to provide an even distribution of the glass fibers on the conveyor because of two problems. First, the circulation of gases within the hood is difficult to control. The gas flow is generally turbulent away from the side walls of the hood and is laminar to quiescent at the side walls. In a conventional hood, more than one air inlet port may be utilized to direct the fibers in the desired patterns, however this has not solved the problem. The second problem apparently involves pressure differentials at the conveyor and immediately above the conveyor. These pressure differences cause the fibers to move or jump after deposition on the conveyor, toward low pressure areas generally adjacent the edges of the conveyor. Even if it were then possible to evenly distribute the chopped fibers on the conveyor initially, the distribution would be changed before the mat leaves the hood.
SUMMARY OF THE INVENTION
The apparatus and method of this invention solves the problem of the prior art by providing a plate or panel immediately below the conveyor, which panel includes a plurality of spaced apertures or holes. The hood includes a suction box which is continuous with the hood and includes a fan or blower which draws the air through the conveyor and the plate at a relatively high rate, such as 2000 feet per minute. The plate creates a back pressure and a relatively static high pressure area immediately above the conveyor, eliminating the problem of random movement of the fibers after deposition on the conveyor and reduces the air circulation problem, permitting an even distribution of the fibers on the mat.
In the preferred embodiment, the plate is located immediately below the conveyor and produces a relatively large pressure drop across the plate. The plate therefore preferably has less than fifty percent open area and should be located within a distance equal to one diameter of the apertures from the foraminous conveyor. In the disclosed embodiment, the holes are equidistant in the plate and are equal in diameter.
Other advantages and meritorious features of the disclosed invention will be more fully understood from the following description of the preferred embodiments and method and the drawings, a description of which follows.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cross-sectioned side elevation of the apparatus of this invention;
FIG. 2 is an end view of the apparatus shown in FIG. 1;
FIG. 3 is a side cross-sectional enlarged view of the foraminous conveyor and plate shown in FIGS. 1 and 2;
FIG. 4 is a top view of the plate shown in FIG. 3; and
FIG. 5 is a side-sectional enlarged view showing a foraminous conveyor with cooperating apertured members immediately below it.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus 20 shown in FIGS. 1 and 2 includes a hood 22 and a continuous foraminous conveyor 24, such as a conventional chain conveyor. The hood 22 is substanitally enclosed, except for the openings for the conveyor and includes side walls 26, 28 and 30. The hood also includes a suction box 32 which is continuous, through channel 34, with the side walls of the conveyor. The suction box includes a blower or fan, shown schematically at 36, which draws or forces air through the foraminous conveyor 24.
In the disclosed apparatus, strands of glass fibers, not shown, are received from a creel or the like in choppers 38. The chopped glass strands are then received in the hood and directed downwardly toward the conveyor 24, by gas passing through the inlet holes or ports 40. The construction of the creel, choppers and ports are well known in the art and disclosed in the above referenced U.S. Pat. No. 2,719,336.
In the apparatus of this invention, a plate 42 is located immediately below the foraminous conveyor 24 and is supported in the hood parallel to the conveyor on suitable supports 44. As shown in FIGS. 3 and 4, the plate includes a plurality of circular apertures or holes 46 through the plate and perpendicular to its faces. The apertured plate thereby provides a substantial pressure drop across the conveyor, as will be described more fully below.
In the disclosed embodiment, the holes are spaced equidistant in the plate and define less than fifty percent of the total area of the plate. For example 3/16 inch holes on 3/4 inch centers provide a sufficient pressure drop across the conveyor for the purposes of this invention. The plate should also be located from the foraminous conveyor by a distance which is less than the diameter of the apertures, as more fully described below.
In the method of this invention using the apparatus of FIGS. 1 and 2, glass strands are received in choppers 38 and moved downwardly toward the foraminous conveyor 24. As described above, the air circulation within the hood normally causes a turbulent flow spaced from the side walls 26 to 28 of the hood. The air flow adjacent the side walls is generally laminar and the air is quiescent at the side walls because of the air-wall friction, as described above.
Air is drawn in the inlet ports 40 and down through the foraminous conveyor 24 and plate 42, through holes 46, by the fan 36 in the suction box 32. The flow rate through the holes 46 is preferably relatively high, for example 2000 feet per minute.
In the preferred embodiment, the plate 42 is located parallel to the conveyor 24 a distance equal to or less than the diameter of the holes 46, creating a back pressure and a relatively static high pressure area immediately above the conveyor, where the chopped strands are deposited on the conveyor. This static pressure area eliminates the jumping or random movement of the chopped glass fibers on the conveyor after deposition and creates a quiescent high pressure area, having a lower flow rate, which aids in the distribution of the fibers on the mat. As will be understood by those skilled in the art, that air drawn through the controlable inlet ports 40 by suction from below creates a downward stream of air inside the hood that directs the fibers to the conveyor. When the fibers reach the high pressure static area immediately above the conveyor, the fibers then settle evenly on the mat.
The method and apparatus of this invention may also be utilized in other applications, such as the manufacture of curly glass fibers, as disclosed in U.S. Pat. No. 2,927,621, wherein the choppers 38 are replaced with feeders. The glass strands are then received in the hood and blowers attenuate the streams of glass into fibers which are collected on the foraminous conveyor. The method and apparatus of this invention is however particularly suitable for the manufacture of chopped fiber glass mats, wherein the chopped fibers are relatively small and subject to random redistribution after deposition on the conveyor.
FIG. 5 is similar to FIG. 3 except that there is a second apertured member for varying the air passageways through the first apertured plate 42. The second apertured plate 43 with holes 47 is movable with respect to the first apertured plate 42 having holes 46. By moving the lower member 43, a portion of the holes 46 in the upper member 42 are blocked so that the air passageways through the first plate are varied. Thus the air flow through the first member 42 is varied. The plates may be moved to cause more air flow in desired areas of the foraminous conveyor.
So it can be seen that the invention provides improvements in apparatus for producing a fibrous layer. In a broad sense, discontinuous fibers are moved to a foraminous surface to form a layer and air is drawn downwardly through the foraminous surface such that a substantially static high air pressure region is established immediately above the surface to reduce movement of the fibers in the layer after their deposition.
More specifically, discontinuous fibers are directed to a foraminous surface to form a layer. Immediately below the foraminous surface is at least one apertured member. Air is drawn downwardly through the foraminous surface and apertured member such that a substantially static high pressure air region is formed immediately above the foraminous surface to reduce movement of the fibers in the layer on the surface.
Having described the invention in detail, it will be understood that such specifications are given for the sake of explanation, and various modifications and substitutions other than those cited may be made without departing from the scope of the invention as defined in the following claims. | The method disclosed herein includes moving the fibers downwardly toward a continuously moving foraminous conveyor, drawing the gas through the conveyor to deposit the fibers on the conveyor, creating a back pressure by locating an apertured plate immediately below the conveyor and collecting the fibers in a relatively static area, immediately above the conveyor. | 3 |
This is a division of application Ser. No. 08/534,230 filed on Sep. 26, 1995, now U.S. Pat. No. 5,729,837, which is a division of Ser. No. 08/192,331 filed on Feb. 4, 1994 now U.S. Pat. No. 5,542,132, which is a division of application Ser. No. 07/976,109 filed Nov. 13, 1992, now U.S. Pat. No. 5,305,475.
BACKGROUND OF THE INVENTION
This invention relates to water saving plumbing fixtures. More particularly, it relates to improved means for using a pump to assist in the operation of plumbing fixtures such as toilets and urinals.
DISCUSSION OF THE PRIOR ART
Gravity feed toilets of the type having a reservoir at least partially above the level of a toilet bowl have in the past typically had a water capacity of 3 or more gallons for flushing the toilet. In recent years the efficiency of these toilets have been improved such that in many cases 1.6 gallons of water is sufficient to clean the bowl. However, where especially large amounts of feces are present double flushing may still be needed to completely clean the bowl. Moreover, it was hoped that additional water savings could be effected if these toilets could be made even more efficient during normal flushes and if less water could be employed to flush when only urine and toilet tissue are in the bowl.
One known way to reduce the amount of water needed to effect flushing is to pressurize the flush water. See U.S. Pat. Nos. 2,979,731, 3,431,563 and 5,036,553. However, these prior systems were complex, costly and usually not suitable to completely fit in standard size toilets. They also suffered from other problems.
Thus a need exists for an improved pump operated plumbing fixture which alters the amount of water used based on the type of material to be flushed, more efficiently sequences the flush water with respect to the rim portion and the bowl portion, permits water distribution to multiple fixtures from a single reservoir, permits alternative placement of the reservoir, permits an aesthetically pleasing compact design, resolves potential water overflow problems, meets safety standards relating to electrical shorting, and has good bowl cleaning and waste evacuation characteristics
SUMMARY OF THE INVENTION
In one aspect, the invention provides a plumbing fixture for receiving flushable waste comprising at least one receptacle for receiving the waste, a reservoir tank for storing a volume of flush water, a pump motor and pump (both positioned in the reservoir tank), the inlet of the pump being in communication with the interior of the reservoir tank, a conduit connected between a pump outlet and the receptacle, and control means selectively and operatively connected to the motor to operate the pump for one period of time to deliver a quantity of flush water to the pump outlet.
In another preferred form, the pump means is positioned either inside or outside the reservoir tank and the control means is selectively and operatively connected to the motor to the pump means to operate the pump for at least one other period of time to deliver at least one other quantity of flush water to the receptacle.
In still another preferred form, there are at least two receptacles for receiving waste such as a toilet and an urinal.
In still another aspect, a refill valve is operatively connected to an intake conduit, and a tube is connected between the refill valve and the rim of a toilet bowl.
In still another preferred form, there are control means which include a time delay means to prevent activation of the pump and overflow of the toilet bowl.
In another aspect, there is a fluid passage means disposed through the tank wall and positioned below the motor and electrical connection to the motor.
In yet another aspect, there is a receptacle for storing a fluid such as a cleaning fluid and an additional pump means for pumping such a fluid into the toilet bowl to clean the toilet bowl.
In yet another aspect, there are overflow prevention means for both the reservoir tank and the toilet bowl. Concerning the reservoir tank, an electrically operated fail-safe valve is connected to the supply conduit to shut off the water supply in the instance where there is a leaky supply valve. There is also an overflow sensor connected to a pump motor to pump excess water from the tank. Concerning the toilet bowl, there is a time delay feature to prevent excessive operation of the pump and flooding of the toilet bowl.
In yet another preferred form, there are first and second conduits connected between the pump outlet and the basin and the rim. Control means connected to the motor and pump sequentially delivers a volume of flush water to the rim, a volume of flush water to the bowl either alternatively, or simultaneously, and in selective sequences.
The objects of the invention therefore include:
a. providing a plumbing fixture of the above kind wherein reduced quantities of water can be employed to remove flushable waste from a toilet bowl or a urinal.
b. providing a plumbing fixture of the above kind wherein a pump and motor can be electrically controlled to deliver different quantities of water and in different timing sequences to a toilet bowl and rim.
c. providing a plumbing fixture of the above kind wherein safeguards are provided to substantially reduce the possibility of overflow conditions.
d. providing a plumbing fixture of the above kind wherein the pump can be easily connected or disconnected to a plumbing fixture.
e. providing a plumbing fixture of the above kind wherein one pump can service a multiplicity of plumbing fixtures.
f. providing a plumbing fixture of the above kind wherein a constant, predetermined volume and flow of water is delivered to the jet channel regardless of supply line pressure or flow characteristics.
g. providing a plumbing fixture of the above kind wherein a cleaning fluid can be pumped from a separate tank to the toilet bowl for cleaning purposes.
h. providing a plumbing fixture of the above kind which can be fitted to standard water supply and waste lines.
i. providing a plumbing fixture of the above kind wherein the pump and the reservoir are positioned remote from a toilet bowl or urinal.
j. providing a plumbing fixture of the above kind wherein flush activation is effected by switches.
These and still other objects and advantages of the invention will be apparent from the description which follows. In the detailed description below, preferred embodiments of the invention will be described in reference to the accompanying drawings. These embodiments do not represent the full scope of the invention. Rather the invention may be employed in other embodiments. Reference should therefore be made to the claims herein for interpreting the breadth of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan, partially fragmentary view of a toilet (with tank lid removed) in which a preferred embodiment of the invention is mounted.
FIG. 2 is a partial sectional view taken along line 2--2 of FIG. 1.
FIG. 3 is a sectional view taken along line 3--3 of FIG. 1.
FIG. 4 is partial sectional view taken along line 4--4 of FIG. 1.
FIG. 5 is a partial sectional view taken along line 5--5 of FIG. 4.
FIG. 6 is a partial sectional view taken along line 6--6 of FIG. 3.
FIG. 7 is a rear elevational view of the toilet shown in FIG. 1.
FIG. 8 is a view in side elevation and partially in section illustrating an alternative embodiment.
FIG. 9 is a rear elevational view in partial section of the toilet shown in FIG. 8.
FIG. 10 is a sectional view taken on line 10--10 of FIG. 9.
FIG. 11 is a view similar to FIG. 8 showing still another alternative embodiment.
FIG. 12 is a diagrammatic view of yet another embodiment.
FIG. 13 is a view in vertical section illustrating in more detail a pump and motor for use in the toilets described herein.
FIG. 14 is a diagrammatic view of a control circuit for the motor and pump.
FIGS. 15A-17C are flow charts showing a signal flow block diagram for the control circuit shown in FIG. 14.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, there is shown a toilet generally 10 having a basin or bowl portion 12 with a hollow rim 14. A "reservoir" 16 is in the form of tank 17. Positioned in the tank 17 is a pump 18 which is of the sump type. It is supported in the reservoir by vibration absorbing feet 19. Pump unit generally 43 includes a pump 18 driven by an electric motor 20 with electric power being supplied by electrical cord 21. The motor 20 drives the pump 18 by means of a sealed and enclosed magnetic drive which is explained below in more detail in conjunction with FIG. 13. It should be noted that one surprising aspect of the invention is positioning an electrical motor in the toilet water tank.
Water enters the pump 18 at inlet 23 and exits the pump 18 by the outlet manifold 25. An outlet conduit 27 delivers water to the lower portion of bowl 12, such as through jet channel 28 (See FIG. 4) attached via connector 68. A smaller conduit 30 delivers water to the rim 14 through the channel 32.
Referring to FIGS. 2 and 3, water enters the tank 17 by the inlet pipe 35 which is connected to a conventional water source. A float valve assembly 37 includes a float 39 which operates a valve (not shown) in pipe 40 by means of rod 42 and lever arm 44. Float 39 is guided by the guide member 45. Water that passes the inlet valve enters the reservoir through the inlet valve hush tube 47. There is also a bypass tube 50 connected to the float valve assembly to deliver a small amount of water to the rim 14 whenever the float valve is in an open condition.
As best seen in FIGS. 4 and 5, there is a return passage 33 between the upper bowl portion 12 and the reservoir 16. This allows for water to pass from the tank to the bowl in case there is an overflow condition in the tank. It also permits flow in the other direction if there is a stoppage in the bowl and a near over flow condition develops.
There is also a dam member 69 which is positioned adjacent the return passage 33 and inside the tank 17. This serves to raise the water level in the tank 17 or the bowl portion 12 before overflowing into the other occurs. A rim vent hole 73 is also provided to facilitate water flow, as best shown in FIGS. 3 and 6.
Referring now to FIG. 7, there are several openings 52 extending through the back wall 11 of the tank 17. The purpose of the openings 52 is that if return passage 33 is blocked to allow overflow water from tank 17 to spill out of the tank. The openings 52 provide a fluid spill passage and are positioned in the tank a distance above the bottom so that overflow water will escape prior to contact with the electrical connection from cord 21 with the motor 20 and are positioned below the point where water could enter the motor. The position of this connection is indicated in FIG. 2. The openings 52 also prevent contaminated water from rising high enough in the tank to contact intake water in pipe 40.
FIGS. 8-11 represent alternative embodiments generally 10A. The same or similar components are designated with the same reference numerals as for the first embodiment except followed by the letter "A". One of the differences between the two embodiments is the placement of the reservoir 16A below the bowl portion 12A and accordingly the water level in the reservoir 16A below that of the bowl portion 12A. A support post 15A for the bowl portion 12A is provided as well as a surrounding housing 22A extending along the sides and back of the bowl portion 12A.
In the FIG. 8 version, positioned on the reservoir 16A is a receptacle 24A which contains a cleaning fluid for cleansing the bowl portion 12A. The cleaning fluid is pumped from the receptacle 24A by means of the conduit 53A connected to the inlet side of the pump 54A driven by the motor 56A. A second conduit 57A extends from the outlet side of the pump 54A to the rim 14A of the bowl portion 12A where it is connected to inlet tube 55A.
FIG. 11 shows an alternative placement of the receptacle 24A outside of the surrounding housing 22A.
FIGS. 9 and 10 particularly illustrate the supply of water to the reservoir 16A, as well as to the rim 14A and bowl portion 12A. The pump 18A and motor 20A are located in the reservoir 16A. Water enters through the float valve assembly 37A and is delivered to the reservoir 16A by the outlet pipe 47A. However, in this instance, inlet water is supplied to the float valve assembly 37A by the supply line 59A. The inlet water is supplied through the back of housing 22A through line 59A and is controlled by a normally closed solenoid which opens, when electrically activated, the valve 60A. Pump 18A supplies water to the bowl portion 12A by means of the conduit 27A which is connected to conduits 27A' and 27A" as well as to manifold 25A. It also supplies water to the rim 14A by the conduit 30A connected to the manifold 25A.
As best seen in FIG. 10, there is a solenoid diaphragm valve 62A connected to conduit 27A'. It is operated by a pilot 63A and is maintained in a closed position until activated to supply water to the bowl portion 12A.
Referring specifically to FIG. 9, there is shown a water level sensor device generally 65A which includes a float 66A mounted on guide rod 64A having an electrical contact cap 67A on the end thereof. Contact by the float 66A with the cap 67A will send an electrical signal to motor 20A to operate pump 18A and thereby determine the maximum level of water 26A in reservoir 16A. Guide rod 64A is supported on bracket 61A which in turn is adjustably connected to support rod 51A. A trapway 49A communicating with the typical outlet drain 58A is also shown.
FIG. 12 illustrates yet another alternative embodiment (generally 70B). The same or similar components are designated with the same reference numerals as for the first embodiment, except followed by the letter "B". In this embodiment 70B, the pump 18B and the motor 20B are located outside of a plumbing fixture such as a wall hung toilet 10B. In this instance, flush water would be contained in reservoir 16B and is pumped from the reservoir 16B by means of the intake conduit 71B and the output conduit 72B. Water is diverted to the toilet 10B and/or the urinal 74B through the diverter valve 75B.
In a preferred manner, the volume of water pumped to the toilet 10B will be 1.6 gallons or less, whereas that normally delivered to the urinal 74B would be 1.0 gallon or less. The volume of water delivered to the toilet 10B and the urinal 74B can be controlled by a timing circuit as is explained later in conjunction with FIGS. 14 and 16A and B.
FIG. 13 shows in more detail a pump 18 which is driven by the motor 20. Both the motor 20 and the pump 18 are enclosed in sealed housings 29 and 31. An electric motor 13 drives rotor 34 having magnets 36 which attract magnets 38 carried by the pump rotor 41. This effects a pumping action causing water to enter at entrance 23 and to exit from manifold 25 (See FIG. 2). It should be noted that placement of the magnets 36 and 38 in their respective plastic housings effects a seal between the rotors 34 and 41, thus reducing the chance of an electrical short into the reservoir water. Foot members 46 provide for suitable spacing of entrance 23 from the bottom of reservoir 16 or 16A (See FIG. 2 or FIG. 3). A support member 48 positions the electric motor 13 at a predetermined distance above the floor of motor housing 29.
FIGS. 14-17C illustrate electrical controls for the previously described embodiments. A microprocessor 80 is programmed to effect the desired and described functions which in the instance of embodiment 10A include a short flush function, a long flush function (which can be activated by the seat cover being closed), as well as a special bowl cleaner flush. These functions can be initiated by the respective switch buttons 81, 82 and 83 which preferably are of the touch type. A switch of this kind would be a membrane switch which would have a long flush and a short flush function in the same switch housing. In the instance of the seat cover closed function, it has in addition to activating switch 84, a monostable multivibrator 85 which is commonly known as a "one-shot".
This particular seat cover closed function is described in more detail in commonly owned U.S. patent application Ser. No. 07/824,808 filed Jan. 22, 1992 which teachings are incorporated herein by reference. See also U.S. Pat. No. 5,590,397. Basically the idea is that the position of a magnet for the bowl lid is sensed by a sensor in the tank and the information leads to control of flushing (e.g. when the lid is first closed, a flush occurs). The level sensor 65A is also inputted to the microprocessor 80. The output side of the microprocessor 80 is connected to the main pump 18A, the pump 54A for the toilet bowl cleanser liquid, and the supply valve solenoid 62A by the lines 86, 87 and 88, respectively. As explained later, in conjunction with embodiment 70B, the short flush button 81 will represent the function of the urinal flush key being pressed as shown at 118 in FIG. 16B.
Referring to FIGS. 15A and B, these represent the flow diagram for embodiment shown in FIGS. 1-7. The first step in the operation of the pump toilet 10 after the start 89 is the decision step 90 as to whether a switch has been activated such as by a key or push button. If a key is not activated, a background timer is updated at 91 and at 92. It is checked to see if it has a designated number of units. If it does, it is reset at 93 and a flush timer is looked at at 94 to determine if it equals 0 seconds. If it does not, it is decremented at 95.
This background timer will operate in conjunction with the flush timer in a manner to be explained in conjunction with the actuation of the later described activation of the long and short keys at 97 and 105 and the timing of the main pump 18. At step 96, the flush timer is checked to see if it is at greater than 30 seconds. If it is not, this allows activation of either the long or short keys at 97 or 105.
If it is the long flush key at 97, such as activated by switch 82, then main pump 18 is turned on at step 99 after a valid input check at 98. This immediately delivers water to the rim portion 14 by way of conduit 30, as well as to the jet in the bowl portion 12 through conduit 27. After a delay of 3.17 seconds as indicated at step 100, the pump 18 is turned off at step 101. This will deliver 1.6 gallons of water and would normally be used to flush fecal matter. At step 102 there is added 60 seconds to the flush timer after which there is a determination made at 103 and 104 as to whether the long or short key has been pressed before another flush cycle is initiated. If instead of the long flush cycle, a shorter one is selected, the short flush key 105 is activated such as by switch 81. After an input check at 106, the pump 18 is activated at 107, and it is operated for 2.07 seconds as indicated at 108. It is turned off at 101 after delivering 1.0 gallon of water. This short flush would normally be used to flush urine and paper. Again 60 seconds would be added to the flush timer as indicated at 102.
The background and flush timers are programmed in conjunction with steps 96 and 102 so that there are two delay features. The first involves a situation where a second flush occurs more than 30 seconds but less than 60 seconds after the first flush. It will be recognized that there is always a 30 second delay between flushes in order to refill the tank 17. In this situation, the toilet may be flushed a second time after the initial 30 second delay, but if this is done, it may then not be flushed a third time until there has been a maximum of 90 seconds from the first flush and add 60 seconds to each flush thereafter. The second alternative involves a situation where the second flush does not occur within 60 seconds of the first flush or 90 seconds after any following flushes. In this case, the background timer automatically resets and the toilet can be flushed again with no limit other than the 30 seconds required to fill the tank. In essence, this means that the toilet may be flushed every 60 seconds without being limited, as in the first case.
Referring to FIGS. 16A and B, these represent the flow diagram for embodiment shown in FIG. 12. It will be seen that steps 89-96 are the same as previously described in conjunction with FIG. 15A. If the toilet flush key 110 is selected, which would be activated such as by switch 82, then the same steps 98-102 would be followed as previously explained in conjunction with FIG. 15B. Similarly, the same determinations of the status of the toilet and urinal flush keys are made at 116 and 117. In the event the seat flush feature is activated such as at 112 and by the lid closed switch 84, the same procedure will be followed as indicated at steps 98-102 for the long flush. In the instance where the urinal flush key is activated at 118, a short flush cycle is initiated which is similar to steps 106-108 and 101 and 102 as described in conjunction with FIG. 15B.
Referring to FIGS. 17A, B and C, these represent the flow diagrams for the embodiment shown in FIGS. 8-10. The steps 89-96 are the same as previously described in conjunction with FIGS. 15A and 16A except for step 122 where supply valve 60A is turned on. If the long flush key 97 is activated, then main pump 18A is turned on at step 99 after a valid input check at 98. This immediately delivers water to the rim portion 14A by way of conduit 30A. Water is prevented from flowing through conduit 27A to the jet in the bowl portion 12A as jet diaphragm valve 62A is closed. After a delay of 0.5 second as indicated at step 123, the solenoid pilot 63A is activated at step 124. This delivers water from pump 18A to flow to the jet in the bowl portion 12A as well as to the rim portion 14A through conduit 30A. After 3.5 seconds as seen at step 100, the valve 62A is closed at step 125. After a delay of 3.0 seconds as indicated at step 126, water continues to flow to the rim portion 14A. After the 3 second delay, the main pump 18A is turned off at step 101. The remaining steps 102-104 are the same as previously described in conjunction with FIG. 15B.
A seat activated function is also shown at step 136 in conjunction with long flush steps 98-101 as previously described.
In the event a shorter flush is desired, such as to flush urine or paper, the short flush button 81 is activated to initiate the short flush as indicated at step 105. The subsequent steps 106-130 are essentially the same as indicated for the respective steps 98-126 except for step 108 where the pump is operated for 2.5 seconds rather than 3.5 seconds.
In addition to the previous flushing functions, there is also an independent cleanser flush indicated at step 131 which delivers a cleaning fluid to the rim portion 14A. After a valid input check at 132, the main pump 18A and the sanitary pump 54A are turned on at step 133A. After a time period of 6.0 seconds at step 133B, the main pump 18A and the sanitary pump 54A are turned off at step 134 after which there is a delay period of 60 seconds as shown at 135.
Referring also to FIGS. 14 and 17B, it is seen that a signal is sent to the microprocessor 80 from the level sensor 65A. This signal is shown as activated at 137 with the main pump 18A being turned on at 138 as well as the jet solenoid to pump water from the reservoir 16A and to the toilet 10A in order to prevent an overflow condition in the reservoir 16A should float valve assembly 37A malfunction. After a delay of 4 seconds, the main pump 18A and jet solenoid are turned off at 140. If the overflow feature has been active 3 times in 60 minutes as shown at 141, the supply valve 60A is turned off at 142 and a waiting period initiated at 143. An additional safety feature in conjunction with the microprocessor 80 is the closing of supply valve 60A in the event of electrical failure to the control circuit and pump 18A and the failure of float valve assembly 37A to close.
Thus our invention provides an improved toilet flushing system which utilizes a minimum of water for each function. The need for double flushing is reduced. While preferred embodiments have been described above, it should be readily apparent to those skilled in the art from this disclosure that a number of modifications and changes may be made without departing from the spirit and scope of the invention. For example, while a delivery of flush water to the rim in a first sequence, to the rim and bowl in a second sequence, and to the rim only in a third sequence has been described in conjunction with the pump toilet, this system can be altered to deliver water only to the rim by eliminating the conduits 27, 27A, 27A' and 27A" to the bowl as well as the valve 62A. Alternatively, flush water delivery only to the bowl can be effected by the herein described system by elimination of the conduits 30 and 30A to the rim and valve 62A. Any combination of the delivery of flush water to the rim and/or bowl can be effected by suitable valving. For example, if it is desired to have water flow only to the bowl in one sequence with a rim-bowl-rim delivery, a valve such as 62A can be placed in conduit 30A. Alternatively, a 3-way valve could be used in conjunction with conduits 27, 27A, 27A', 27A" and 30A.
A long and short flush cycle have been described in conjunction with the previously disclosed embodiments. It should be understood that these two cycles can be employed independently of the bowl cleaner flush or the seat cover activation. In the same manner, a third longer flush cycle could be utilized with the long and short flush cycle as well as an intermediate one with varying quantities of flush water. Similarly, if desired, only a single flush cycle could be employed by eliminating one of the flush cycles and still operate the pump for a period of time to deliver a quantity of water from the reservoir tank to the toilet bowl. While the reservoir 16B and pump 18B have been described in conjunction with one toilet 10B and one urinal 74B, a multiplicity of these plumbing fixtures could be employed by interconnection with output conduits 73B and 74B. All of the flush cycles previously described in conjunction with embodiment 10A can be utilized with toilet 10B.
Further, the seat cover and sanitation functions could be eliminated and still accomplish the water saving feature. Similarly, the overflow features could be eliminated and still accomplish the described water saver functions. Also, the cleanser function could be automated such that the processor would count uses such that after a given number of uses of a toilet (e.g. thirty), the cleaning cycle would automatically occur. A long and short flush cycle have been effected by operating a pump motor for different time intervals. This could also be accomplished by running the pump motor at two different speeds as shown alternatively in dotted line in FIG. 15B. All such and other modifications within the spirit of the invention are meant to be within the scope of the invention. | A toilet has a pump to deliver selected quantities of water from a reservoir to a toilet bowl so as to effect a water savings. In one aspect, both the motor and pump are positioned in the reservoir to deliver water to both the rim and bowl portions. In another aspect, there are conduits connected between the basin, the rim and controls which are provided to deliver water to the rim and bowl either independently, simultaneously or in selective sequences. In alternative embodiments, a refill tube is connected to an intake conduit and the rim of the bowl to effect a water seal, a fail safe valve is connected to the supply conduit, a receptacle with a cleaning fluid and a pump is connected to the bowl and there are at least two receptacles for receiving waste. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to digger and trencher equipment. More specifically, the present invention is a retractable assembly for use on portable diggers and trenchers used to add stability to the digger or trencher equipment while such equipment is in use.
2. Related Art
Many types of digger and trencher equipment ("trenchers") are disclosed in the prior art. These trenchers encompass many different types: from large, industrial trenching apparatuses used for the creation of very large and very deep trenches; to smaller, portable apparatuses used for smaller trenches. The present invention generally concerns portable diggers and trenchers, but may be used on industrial trenching apparatuses.
Of these portable trenchers, there are three main types: those which are an attachment for another vehicle or piece of equipment, those which have two main wheels and those which have four or more main wheels.
Portable trenchers can be attached to other vehicles and equipment. An example is U.S. Pat. No. 4,833,797 (Slunecka), which discloses a trencher attached to a steerable, self-propelled, wheeled tractor. The benefit in such an attachment is the fact that the trencher can be used anywhere a tractor can tow it. However, the need to use a separate vehicle, such as the tractor, to operate such a device greatly reduces the device's ease of use, and causes difficulties in using the device in confined places. Other examples of such attached equipment include: U.S. Pat. No. 4,483,084 (Caldwell); U.S. Pat. No. 3,834,049 (Bond); and U.S. Pat. No. 2,817,167 (Barber).
As mentioned above, portable trenchers may also have two main wheels. Such portable trenchers may also have a smaller, third wheel near the front of the trencher for added stability, as shown in U.S. Pat. No. 5,228,221 (Hillard). Other examples of portable trenchers with dual main wheels include: U.S. Pat. No. 2,997,276 (Davis); U.S. Pat. No. 3,087,354 (Malzahn); U.S. Pat. No. 4,322,899 (Clune); and U.S. Pat. No. 4,103,441 (Flippin).
The benefit of using a trencher with two main wheels is maneuverability. Being able to pivot on two wheels give such trenchers a very small turn radius, a feature that is very useful in digging multiple and curved trenches.
A drawback of such two main wheeled trenchers involves digging arch and kickback. As the bladed boom of the trencher is inserted and used in the soil to dig a trench, the front portion of the trencher in relation to the rear portion tends to raise up (digging arch) and jerk backward (kickback) when the bladed boom strikes buried stones and tree roots.
Finally, portable trenchers may have four or more main wheels. These trenchers range from small vehicles with built-in trenchers, to small, portable trenchers having four or more wheels. The benefit of having at least four wheels is that the trencher is very stable and does not suffer from digging arch or kickback to such a large degree as portable trenchers with two main wheels do. However, the drawback of such trenchers with four or more main wheels is the lack of ease of use and maneuverability, especially in tight corners or where multiple trenches and curves are required. Examples of such trenchers include: U.S. Pat. No. 4,913,581 (Weiler); U.S. Pat. No. 2,946,142 (Swanson); U.S. Pat. No. 4,896,442 (Stiff); U.S. Pat. No. 2,990,631 (Brown); U.S. Pat. No. 2,835,055 (Hermes); and U.S. Pat. No. 3,057,088 (George, et al.).
Thus, there is a need to create a trencher which combines the maneuverability and ease of use of the portable trenchers with two main wheels with the stability and resistance to digging arch and kickback of portable trenchers with four or more main wheels.
SUMMARY OF THE INVENTION
The present invention is a retractable walk-behind power unit stabilizing system assembly for use on walk-behind power equipment, such as portable trenchers. Walk-behind power units have a front side, a rear side, and at least one rear drive wheel near the rear side of the body of the power unit. A portable trencher generally comprises a trencher body having an engine and wheels, and a trenching boom having a trenching chain. The present invention comprises a retractable wheel or other bracing assembly mounted at the rear of a trencher, behind and spaced from the rear drive wheels, and extending downward from there. Preferably there is no other apparatus touching the ground behind the invented assembly. The invented assembly is allowed to be maneuvered by the user from a lower, stabilized position, where the invented wheel or other brace contacts the ground, to an upper, transport position. While the preferred embodiment of the present invention is to be used on trenchers of the two main wheeled variety, use on other trenchers and even other equipment is also envisioned by the inventor. Preferably, the invented assembly contacts the ground at least six inches behind the rear drive wheels.
The preferred embodiment comprises at least one wheel and a retractable system for connecting the wheel to the trencher or equipment body and for moving the wheel into the upper and lower positions. The retractable system may include pivoting, articulated, hinged, sliding or other moveable linkages. Generally, the linkage moves the wheel upward and downward within a vertical plane. A lock system, suspension system, drive system, and additional support system may be included to further optimize the invented device.
The present invention is preferably a separate wheel assembly device mounted at the rear of the trencher. Such mounting is done so that the device's wheel or wheels are oriented in the same direction as the other wheels of the trencher. While two wheels are envisioned in the preferred embodiment, the inventor also envisions embodiments using more or fewer wheels than two.
The device can easily be moved from the upper, transport position to the lower, stabilized position, and vice versa. Movement from the upper position to the lower position is simply done by the operator using his/her foot to push downward on the toe-kick bar which moves the device lower and then locks the device into a lower position. As the toe-kick bar is pushed lower by the foot of the user, tension caused by retraction springs is overcome, thereby allowing the device to be moved into the lower position. As the toe-kick bar is pushed lower, the device moves downward, approximately until the wheels of the device touch the ground. At this point, the device locks into place within the lower, stabilized position. This lock must be released before the user will be able to raise the device into the other, upper position.
To move the device to the upper position, the user merely needs to use his or her foot to push in on the disengagement flange. As the disengagement flange is pushed in, in the direction of the front of the trencher, the device is unlocked from the lower position. Once the device is moved out of this position, the user can remove his/her foot from the disengagement flange and the device will retract automatically by the retraction of the retraction spring or springs. While the preferred embodiment uses two retraction springs, the inventor envisions that any number of retraction springs, or even other lifting means, such as hydraulics, could be used in other embodiments.
The trencher can be stored or transported in or on a vehicle in either the upper or the lower position. However, the lower, stabilized position is preferred for its stabilizing properties, in that it keeps the trencher in better contact with the surface it is being transported on or over, for instance a trailer.
In use, the portable trencher is first maneuvered into position. During such maneuvering, the invented device is positioned into the upper, transport position. Maneuvering the trencher into position can be done either by manually pushing, pulling and directing the trencher into place or through steering the trencher and using the trencher's built-in wheel drive, if the trencher has such a capability. Because the preferred embodiment has driven wheels, the user may opt to move the trencher into the general area to be trenched while the device is in the lower, stabilized position in order to use the invented device's driven wheels for increased traction and power.
When the user maneuvers the trencher into the general area in which the user intends to create a trench, the user then disengages and retracts the device to allow the device to be moved into exact place by pivoting upon the trencher's two main wheels. The trencher can be pivoted on its two main wheels and maneuvered to the exact location where the user intends to dig the trench. When the user determines that the portable trencher is in place, the retractable wheel assembly is moved into the lower, stabilized position, and is then locked into this lower position.
When the operator of the trencher is finished using the trencher, or wishes to move the trencher to another location, the operator merely needs to unlock the invented device, and the retraction spring or springs will lift the invented device into the upper position. The user could then pivot and steer the trencher to the desired next location using only the two main wheels, or the user could pivot the trencher into the desired direction, then lower and engage the device's wheels, thereby allowing the user to move to the next location by using "four-wheel" drive.
Any such pivoting on the two wheels done by the user may require the user to slightly apply downward force to the rear of the trencher unit, preferably through pushing down on the trencher's maneuvering handles, so that the front leading wheel, if present, is picked up off the ground. This allows the trencher to pivot more freely.
A main benefit of the invented device is that in the lower, stabilized position, the trencher becomes more stable due to the fact that the trencher no longer experiences digging arch, and kickback is greatly reduced. Both digging arch and kickback make the use of a trencher a physically demanding task, especially in rocky soil. With the present invention, the trencher becomes much easier to operate and is considerably less physically strenuous.
As mentioned before, digging arch happens when the trencher chain, while in the ground, strikes a rock or other item, causing the front of the trencher to arch up in relation to the digging chain and the rear of the trencher. Such arch is caused by the trencher pivoting at the trencher's main wheels. The present invention eliminates this pivot point through the addition of an additional wheel or wheels to the rear of the trencher's two main wheels. Not being able to pivot at this location results in the elimination of digging arch.
Kickback is the jerking and jarring motion caused by the trencher chain striking firm soil or small rocks. This kickback increases the physical exertion required to operate the trencher. In the present invention, this kickback is greatly reduced by the use of a suspension system having at least one suspension spring and/or at least one shock absorber. This suspension system greatly reduces these jerking and jarring motions through absorbing them.
An additional benefit of the invented device is depth management. Maintaining a consistent depth using a traditional portable trencher is difficult. This is due to the fact that the trencher pivots within a vertical plane at the attachment point of the two main wheels. As the trencher digs deeper and strikes soils of differing densities, it pivots along the wheel pivot, making it difficult to maintain a constant depth. This is because, depending on the degree of pivot at the wheel, the greater the depth the trencher bar and chain are inserted in the ground, which results in a trench of varying depth. However, if the invented device is used, the center of gravity for the trencher shifts behind this wheel pivot, thereby eliminating this pivoting action and allowing the trencher to dig at a constant depth.
Another benefit of the invented device is the increased ability to traverse generally perpendicular trenches. Sometimes, a user may create multiple trenches. In doing so, the trencher may need to be transported across trenches already dug. As a traditional trencher traverses such trenches, the two main wheels of the trencher may become stuck within a previously-dug trench.
If the trencher is being used in really rocky soil, the trenches dug may end up being wider than the trencher chain would normally dig. This is due to the fact that the walls of the trench tend to collapse into the trench as the digger chain removes large rocks. This collapse results in wide trenches which are difficult to cross with trenchers of the two main wheeled variety. By adding an additional wheel or wheels, especially if such wheel or wheels are driven, the trencher can traverse multiple and wide trenches much more easily due to the fact that the trencher's wheel base is lengthened.
An additional benefit of the invented device is improved ground insertion of the trenching boom and chain. In traditional two main wheeled trenchers, due to the fact that the trencher pivots at the two main wheels as the boom and chain in inserted into the ground, the trencher tends to pivot at these wheels. Similar to digging arch, this insertion arch pivoting reduces the force that can be used to force the boom and chain into the ground. However, if the invented device is added to a trencher, the result is a shift in the trencher's center of gravity to a point behind the two main wheels, thereby eliminating this pivot point. By eliminating this pivot point, a hydraulic system located on the trencher can be used to force the digging boom and chain into the ground. Additionally, the addition of the invented device's wheel(s) essentially serves as a fulcrum point allowing the trencher to better force the digging boom and chain into the ground.
Another benefit of the invented device is trench straightening. The use of a traditional trencher often results in the challenge of repeated realignment of the trencher within the direction of travel to achieve a straight trench. This is due to the fact that traditional trenchers are constantly and jarringly moved forward to rearward, side to side, and upward and downward due to the effects of digging arch and kickback. This movement often causes the trencher to drift away from a straight line of travel, thereby making the digging of a straight line difficult. Use of the invented device greatly reduces this off-line movement due to the reduction or even elimination of digging arch and kickback. Additionally, having an additional wheel(s) on the ground helps the user maintain a straight line by allowing the user to aim and direct the added wheel to follow the path of the trench desired to be dug.
The inventor envisions that the invented device will be installed on trenchers of the two main wheeled type at the factory, however, other installations are as well envisioned.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side, perspective view of one embodiment of the invented retractable wheel assembly attached to a portable trencher with two main wheels and a smaller trailing wheel. This figure shows the assembly in the lower, stabilized position.
FIG. 2 is a is a partial, side view of the device of FIG. 1, showing the invented assembly in the lower, stabilized position.
FIG. 3 is a partial, side view of the device of FIG. 1, showing the invented assembly in the upper, transport position.
FIG. 4 is a rear, perspective view of the device of FIG. 1 in the lower position, showing the user's foot location after the toe kick bar had been depressed, thereby locking the device in the lower position.
FIG. 5 is a rear perspective detail view of the device of FIG. 1 in the upper position.
FIG. 6 is a side, schematic, partial view of the device of FIG. 1, showing the disengagement flange located on the left linkage arm being moved from a locked position to an unlocked position.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In this application, the term "forward" means "toward the end of the trencher where the trailing wheel is located," "rearward" means "away from the end of the trencher where the trailing wheel is located," "distal" means "away from the center of the trencher," and "proximal" means "toward the center of the trencher."
Referring to the Figures, there is depicted generally one, but not the only, embodiment of the invented retractable wheel assembly 100. As shown in FIG. 1, the invented device 100, is adapted for use on portable trenchers and other equipment. The equipment illustrated in FIG. 1 is a portable trencher 10 having a pair of main wheels 80, a trailing wheel 85, a trencher boom 90, and a digging chain 95. As shown in this figure, the invented retractable wheel assembly 100 is attached to the rear of the portable trencher 10, in alignment with the main wheels 80 and the trailing wheel 85.
As show in FIG. 2, the preferred embodiment of the invented device 100 comprises: a linkage system 20 for raising and lowering the invented device 100, a swing arm system 30 for mounting a wheel system and assisting the invented device 100 in swinging between an upper position to a lower position, and a retractable wheel system 86 for traction, support and stability. The preferred embodiment also preferably further comprises a drive system 70 and a suspension system 50.
The linkage system 20 comprises at least one linkage arm and a crank system 60. In the preferred embodiment, the linkage system 20 comprises a pair of linkage arms: a left linkage arm 14 and a right linkage arm 16, attached to a crank system 60. The left linkage arm 14 and the right linkage arm 16 are essentially mirror images of one another with the exception that the distal end of the lower linkage arm 21 of the right linkage arm 16 is elongated and has a toe kick bar 27 extending perpendicularly. Both of these differences are more thoroughly described infra.
The right linkage arm 16, as shown in FIG. 2, comprises a lower linkage arm 21 attached at a proximal end to the distal end of an upper linkage arm 22 at a linkage arm joint pivot 24. In the preferred embodiment, the upper linkage arm 22 comprises a pair of opposing arm pieces. The lower linkage arm 21 is further attached at a lower linkage pivot 26 to a linkage attachment 38, at or near the center of the lower linkage arm 21. The linkage attachment 38 is part of the swing arm system 30, discussed infra. A toe kick bar 27 extends perpendicularly from the right linkage arm 16 from near the distal end of the lower linkage arm 21. A lower support bar 25 extends perpendicularly from the lower linkage arm 21 at a point between the lower linkage pivot 26 and linkage arm joint pivot 24. The proximal end of the upper linkage arm 22 attaches to the upper crank arm 64 at an upper linkage pivot 66.
The left linkage arm 14 comprises a lower linkage arm 21' attached at a proximal end to the distal end of an upper linkage arm 22' at a linkage arm joint pivot 24'. In the preferred embodiment, the upper linkage arm 22' comprises a pair of opposing arm pieces. The lower linkage arm 21' is further attached at a lower linkage pivot 26' to a linkage attachment 38', at or near the proximal end of the lower linkage arm 21'. The linkage attachment 38' is part of the swing arm system 30, discussed infra. A lower support bar 25 extends perpendicularly from the lower linkage arm 21' at a point between the lower linkage pivot 26' and linkage arm joint pivot 24'. This lower support bar 25 extends between the left linkage arm 14 and the right linkage arm 16. The proximal end of the upper linkage arm 22' attaches to the upper crank arm 64' at an upper linkage pivot 66'. As shown in FIG. 6, a disengagement flange 23 connects perpendicularly the upper linkage arm 22' near the linkage arm joint pivot 24'. Another embodiment of a disengagement flange 23 is depicted in FIG. 1, this embodiment attaching to and extending from the lower support bar 25.
In the preferred embodiment, each crank system 60 comprises an upper crank arm 64, a crank pivot 63, a crank flange 68, and a lower crank arm 62. The upper crank arm 64 is attached to the proximal end of the upper linkage arm 22 at an upper linkage pivot 66. The upper crank arm 64 pivotally attaches at the crank pivot 63 to the crank flange 68. The crank flange 68 attaches to the trencher frame 51.
The linkage system 20 cooperates with the swing arm system 30 to assist the invented wheel system in retracting. This cooperation is described further infra.
In the preferred embodiment, the swing arm system 30 comprises a chain guard swing arm 36 attaching to the retractable wheel system 86 at a first end and attaching to the trencher body at a second end. The right linkage attachment 38 is attached to the right side of the generally rearward upper portion of the chain guard swing arm 36. The left linkage attachment 38' attaches to the left side of the rearwardly upper portion of the chain guard swing arm 36. These linkage attachments 38, 38' attach to the respective lower linkage arms 21, 21' at the respective lower linkage pivots 26, 26'. The right linkage attachment 38 also has a rearwardly mounted linkage arm stop 32. The stop 32 serves to stop the forward movement of the lower linkage arm 21 as the lower linkage arm 21 pivots at the lower linkage pivot 26.
The invented retractable wheel assembly 100 is able to be moved between an upper position (shown in FIG. 3) and a lower position (shown in FIG. 2). When the assembly 100 is the lower position, the linkage arm system 20 is locked into place by the hyper-extension of the right linkage arm 16 at the linkage arm joint pivot 24. This movement and locking in the lower position is described as follows: as the toe kick bar 27 is depressed by the user to move the assembly to the lower position, the right linkage arm pivots at the lower linkage pivot 26, the linkage arm joint pivot 24, and the upper linkage pivot 66. This pivoting continues until the lower linkage arm 21 contacts the mounted linkage arm stop 32 and until the upper support bar 65, attached to the upper linkage arm 22 and the crank system 60 at the upper linkage pivot 66, rotates to its rotational limit or stop. This rotational limit or stop is the furthest position within the vertical plane that the crank pivot 63 allows the upper crank arm 64 to pivot. When the pivoting of the lower linkage arm 21 continues to these two stops, the linkage arm joint pivot 24 is extended to a point resulting in the hyper-extension of the lower linkage arm 21 and the upper linkage arm 22. The consequent locking of the device 100 into the downward, lower position is illustrated by position A in FIG. 6.
If the user wishes to move the assembly 100 from the lower position to the upper position, the user must first push in, forward, on the disengagement flange 23 which is perpendicularly attached to the upper linkage arm 22' near the linkage arm joint pivot 24'. As shown in FIG. 6, this action serves to unlock arm system 20 by pushing the lower linkage arm 21 and the upper linkage arm 22 into position B in FIG. 6. The retraction springs 58, 58' then automatically lift the retractable wheel 87 into the upper position. As the assembly 100 is raised, the chain guide swing arm 36, which is attached to the linkage arm system 20, pivots along its attachment at the trencher body. Another embodiment of the present invention, shown in FIG. 1, has the disengagement flange 23 located on the lower support bar 25. As such, pushing in, or forward, on the disengagement flange 23 unlocks the arm system 20 and allows the retraction springs 58, 58' to automatically lift the retractable wheel 87 into the upper position.
In the preferred embodiment, the retractable wheel system 86 comprises at least one retractable wheel 87, and a wheel attachment means 88. The wheel 87 attaches to the swing arm system 30 by the wheel attachment means 88. The wheel attachment means 88, at a rear drive sprocket 74, attaches the swing arm system 30 to the drive system 70.
In the preferred embodiment, the drive system 70 comprises a chain 72 running between a rear drive sprocket 74 and a driven front drive sprocket 76. Other drive means are envisioned by the inventor, including belts and gears. Alternatively and less preferredly, the wheel 87 may not be connected to a drive system. The rear drive sprocket 74 is attached to the wheel attachment means 88.
In the preferred embodiment, the suspension system 50 comprises at least one retraction spring 58, a suspension spring 52, and/or at least one shock absorber 53. The suspension spring 52 attaches at one end to the trencher frame 51 and at the other end to lower crank arm 62 located on the upper support bar 65 by a suspension spring attachment 54. The shock absorber 53 attaches to the trencher frame 51 at a point generally above the retractable wheel 87 and attaches to the retractable wheel system 86 at or near the front of the retractable wheel 87 on the chain guard swing arm 36. The retraction spring 58 attaches at a first end to the trencher frame 51 directly above the invented assembly 100 at an upper spring attachment 82. The retraction spring 58 attaches at a second end to the lower spring attachment 84 which is attached to the base of the chain guard swing arm 36. The preferred embodiment uses a pair of retraction springs 58, 58' connected to upper spring attachments 82, 82' and lower spring attachments 84, 84'. Said upper spring attachments 82, 82' are located on the upper trencher body. The shock absorber 53 and the suspension spring 52 serve to dampen vibrations and movement of the trencher 10 in relation to the invented retractable wheel assembly 100.
While the preferred embodiment discloses a linkage arm type arm for maneuvering the apparatus 100 from a lower to an upper position and vice versa, it is envisioned by the inventor that other arms may also be used. Examples of such arms include articulated arms, pivoting arms, sliding arms and hinged arms. Alternatively, a non-wheeled assembly may be included in the broad disclosure of the invention, for example, a bracing arm extending from the trencher to the rear and to the ground for providing many of the benefits of the wheeled version.
Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the scope of the following claims. | The present invention is a walk-behind power unit stabilizing system for use on portable trenchers and other equipment. The preferred application comprises a retractable wheel assembly mounted at the rear of a trencher where the invented device is allowed to be maneuvered by the user from a lower, stabilization position to an upper, transport position. The device has a handle that allows the user to move the device from the upper, transport position to the lower, stabilized position, and vice versa, easily by raising and lowering the handle, either by hand or by moving the handle up or down using the user's foot. Some of the main benefits of the invented device include: ease of use; a reduction in the physical labor required to operate a trencher; stability; the ability to more consistently control the depth at which the trench is dug; an increased ability to traverse perpendicular trenches; increased force exerted on the boom when inserting the boom into the ground; and trench straightening. | 4 |
FIELD OF THE INVENTION
The present invention is generally concerned with optical lenses, and in particular ophthalmic lenses, made from a thermoplastics synthetic material such as polycarbonate, for example.
It is more particularly directed to the situation in which, as in the method which is the subject matter of French patent application number 88 14046 filed 27 Oct. 1988 (published number 2 638 391), a lens of this kind is formed from a lens blank which is heated so that natural thermal sagging under a reduced static load causes it to mate with the shape of an underlying molding shell.
BACKGROUND OF THE INVENTION
An advantage of a shaping process of this kind is that it can produce directly the final geometry of the required optical lens so that the latter is directly usable by the optician.
Another and more important advantage is that it produces only weak and even tension stresses within the optical lens.
In practise these internal tension stresses are only in the order of one tenth of those in an optical lens made in the conventional manner by injection molding.
However, regardless of the process by which they are shaped, thermoplastics synthetic material optical lenses have a further disadvantage in their mediocre resistance to abrasion.
It has therefore been proposed to coat at least one side of such lenses with a thermosetting synthetic material protection film which has good resistance to abrasion.
Various coating methods have been proposed, the diversity of which bears witness to the difficulty of this problem.
The most usual method is first to shape the optical lens to its final geometry, whether by injection molding or by natural thermal sagging, and then to apply the necessary thermosetting synthetic material coating composition or varnish to the optical lens, and finally to harden, i.e. polymerize the coating composition by heating or by radiation.
Apart from the fact that the thickness of the resulting film is not always easy to control, a drawback of this coating method is that by its very nature it introduces an additional stage of manufacture, necessarily being carried out at a different stage from that in which the optical lens itself is made.
To combine these two stages into one attempts have been made to form the optical lens to its final geometry when already coated with its protective film, the latter being at least partially hardened beforehand.
This is the case, for example, in French patent application number 77 20742 filed 6 Jul. 1977 (published number 2 358 256) and in U.S. Pat. Nos. 2,322,310, 2,481,809 and 2,640,227.
All these methods conventionally require the application of high pressures (in the order of 7 kg/cm 2 to 300 kg/cm 2 ) in a press and in an uncontrolled manner and therefore result in non-negligible internal tension stresses in the optical lens finally obtained.
When the protection film applied to the optical lens is totally polymerized before final shaping of the lens, the shaping almost inevitably causes cracking of the protection film because of the stresses occurring at the interface between it and the substrate it covers.
If the protection film is only partially polymerized before final shaping of the optical lens it is difficult to control its thickness at the end of the shaping process.
Finally, if the pressure that has to be used to shape the optical lens to its final shape is particularly high, it necessitates softening of the substrate beforehand, which is undesirable.
OBJECT AND SUMMARY OF THE INVENTION
A general object of the present invention is a method for obtaining in a single stage but without the above drawbacks a thermoplastics synthetic material optical lens coated on at least one side with a thermosetting synthetic material protection film.
It is based on the observation, not previously made, that if in the shaping process by natural thermal sagging a mold release agent is used on the molding shell, the mold release agent is transferred from the molding shell to the optical lens, adhering thereto and, surprisingly, that the same applies to any other coating composition if the latter is not fully polymerized.
Based on this observation, the method according to the invention is generally characterized in that starting from a thermoplastics synthetic material lens blank and a molding shell to the molding surface of which of a thermosetting synthetic material coating composition has been applied, said lens blank is disposed horizontally, vertically above said molding shell and heated to cause natural thermal sagging under a reduced static load of the lens blank until by contact with the coating composition on the molding surface of the molding shell it mates with the shape of said molding surface.
At the end of this process the coating composition, used on its own or together with a mold release agent, is entirely transferred from the molding shell to the lens blank, which is shaped to its final shape, the coating adhering to the lens in the required manner.
Thus in a single stage there is easily obtained an optical lens made from a thermoplastics synthetic material by natural thermal sagging having only weak and even internal stresses or no internal stresses at all and directly usable by an optician because it is directly shaped to its final shape and is coated on at least one side with the thermosetting synthetic material protection film having all the necessary abrasion resistance and adhering perfectly to the substrate it covers.
The technique usually called "in mold coating" (IMC) is a known method of coating an article within the mold in which it is made.
However, until now this technique has been used only for thermosetting synthetic material substrates of the same kind as the coating composition applied to them and the latter is introduced into the mold in the liquid state.
The combination is reactive, interaction inevitably occurring between the substrate during polymerization and the liquid coating composition with which it is in contact. The end result is some homogenization of this combination, to the detriment of the inherent qualities of the coating composition and therefore those of the protection film it produces.
This is absolutely not the case in the method according to the invention which, to the contrary, is intended to produce and succeeds in producing a heterogeneous product with a clear distinction but nevertheless all the required adherence at the interface between a thermoplastics synthetic material substrate and a thermosetting synthetic material protection film retaining intrinsically all its hardening quality.
It has to be emphasized that this result is entirely surprising.
The treated lens blank comes into contact progressively with the coating composition as it sags when heated at the same time as the coating composition is polymerized, there having previously been nothing to suggest that, despite the changing nature of the coating composition, when its application to the lens blank itself being shaped is completed a perfectly satisfactory protection film could be obtained.
To the contrary, it has been necessary to overcome some prejudice which holds that it is not normally possible to obtain a satisfactory product reproducibly if the nature of the constituents of the product changes during its formation.
This is the case in the method according to the invention, however.
The invention also reconciles in a satisfactory manner two normally contradictory requirements, yielding good adherence between two constituents of different kinds while minimizing the risk of tension stresses at the interface between them.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the invention emerge from the following description given by way of example with reference to the appended diagrammatic drawings in which:
FIG. 1 is a perspective view of an optical lens which can be formed by the method according to the invention;
FIG. 2 is a partial view of the lens to a larger scale and in axial cross-section on the line II--II in FIG. 1;
FIG. 3 shows to a still larger scale part of FIG. 2 marked by a frame III in FIG. 2;
FIG. 4 is an axial cross-section view to a different scale showing the implementation of the method according to the invention prior to shaping of the original lens blank;
FIG. 5 shows to a larger scale the part of FIG. 4 shown by a frame V in FIG. 4;
FIGS. 6A, 6B are axial cross-section views analogous to those in FIG. 4 for two successive phases in shaping of the optical lens;
FIG. 7 is a diagrammatic elevation view to a different scale of an oven used for the shaping method.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the figures, the overall aim is to obtain an optical lens 10 which, forming a thermoplastics synthetic material (for example polycarbonate) substrate, is coated on at least one side with a thermosetting synthetic material protection film 11.
In the embodiment shown in FIGS. 1 to 3 the optical lens 10 is a concave-convex ophthalmic lens and before it is trimmed to size, as shown, it has a circular contour with a flat edge of diameter D and average thickness E.
In this embodiment only its convex side 12 is coated with a protection film 11.
The thickness of the protection film 11 is e.
This thickness e is only a fraction of the thickness E, being in practise less than one thousandth of the latter.
The optical lens 10 is made by the natural thermal sagging method as described in French patent no 2 638 391.
The content of this French patent is hereby incorporated by way of reference.
Briefly, referring to FIG. 4, starting from a thermoplastics synthetic material (for example polycarbonate) lens blank 10' and a molding shell 14I having a molding surface 15I whose geometry corresponds to that required for the corresponding side of the lens to be formed, the lens blank 10' is disposed horizontally, vertically above the molding shell 14I with the molding surface 15I of the molding shell 14I facing upwards, and heated to cause natural thermal sagging under a reduced static load of the lens blank 10' until it mates with the shape of the molding surface 15I.
In the embodiment shown, and in the method described in detail in French patent no 2 638 391, the molding shell 14I rests on a shoulder 16 projecting from a lower part of the inside surface of a ring 17, the lens blank 10' itself resting on a shoulder 18 projecting from the inside surface of a ring 19 which bears on the molding shell 14I and which has at its base vents 20. A molding shell 14S is mounted to slide freely in the ring 17 above the lens blank 10', bearing on the latter, its downwardly facing molding surface 15S having the required geometry of the respective side of the lens 10 to be shaped.
The ring 17 defines with the molding shells 14I, 14S a mold 22 which in the embodiment shown is thermally insulated on the outside and over all of its height by an insulative thermal jacket 23.
As an alternative to this the ring 17 and the insulative thermal jacket 23 can be in one piece.
To bring about the required thermal sagging the mold 22 and the lens blank 10' therein are inserted in the direction of the arrow F1 in FIG. 7 into a tunnel oven 24 which has, in addition to a loading area 25 at its inlet end and an offloading area 26 at its outlet end, a plurality of successive separate areas Z1, Z2, . . . ZN with their temperature individually controlled and a conveyor 28 running along its entire length for transferring the mold 22 from its entry end to its exit end in the direction of the arrow F2 in FIG. 7.
As an alternative to this the tunnel oven 24 can have only one heating area, the temperature in which is varied during the thermal sagging process.
After passing through the tunnel oven 24 the mold 22 is removed therefrom in the direction of the arrow F3 in FIG. 7.
In the embodiment shown the lens blank 10' is flat.
The side of the optical lens 10 to be shaped which is to be coated with a protection film 11 being its convex side 12, the molding surface 15I of the bottom molding shell 14I is concave and the molding surface 15S of the top molding shell 14S is convex.
According to the invention, and prior to the natural thermal sagging process, a thermosetting synthetic material coating composition 11' is applied to the molding surface 15I of the molding shell 14I in the form of a film covering all of this molding surface 15I.
The lens blank 10' therefore comes into contact with this coating composition 11' when, as a result of natural thermal sagging, it mates with the shape of the molding surface 15I of the molding shell 14I disposed beneath it.
At the end of the natural thermal sagging process, and as shown in FIG. 6B, the coating composition 11' is transferred from the molding shell 14I to the lens blank 10', the coating composition 11' then forming on the optical lens 10 obtained the required protection film 11, adhering as required to its convex side 12.
On first contact of the lens blank 10' with the coating composition 11', the latter has preferably reached a temperature in excess of its gel point in order to limit if not eliminate any lateral flow thereof.
In other words, the coating composition 11' is preferably no longer liquid at this time.
To this end, and as described in more detail below, it is first dried or prepolymerized.
In any event, it preferably has added to it a catalyst adapted to render polymerization progressive and so favor its adherence to the lens blank 10'.
As shown diagrammatically in FIG. 6A first contact of the lens blank 10' with the coating composition 11' is preferably in the central area of the molding shell 14I.
This prevents any air pocket being trapped between the molding shell 14I and the lens blank 10' during its natural thermal sagging.
One function of the ring 19 is to achieve this result.
As it passes through the tunnel oven 24 inside the mold 22 the lens blank 10' is heated to a temperature T between its vitreous transition temperature T g and its melting point T f , without reaching the latter.
The coating composition 11' used must naturally be chosen accordingly.
In other words, it must be able to withstand the temperature T without deteriorating.
It must also be chosen such that its shrinkage between this temperature T and room temperature is comparable with that of the thermoplastics synthetic material of the lens blank 10'.
This is so that the protection film 11 that it forms on the surface of the resulting optical lens 10 is not detached from the latter on cooling.
To the contrary, it seems that although there is a clear interface between the protection film 11 and the substrate that it covers, there is excellent adherence between it and the latter, passing the usual adherence tests, and considered to be the result of a physical-chemical process.
Release of the optical lens 10 from the mold is also good, its protection film 11 not adhering to the molding shell 14I.
The static load to which the lens blank 10' is subjected during its natural thermal sagging process is preferably restricted to a value below 10 kg.
This static load is preferably restricted to a value between 2.5 kg and 50 g.
As shown, this static load in practise is the result of gravity alone.
It is restricted to the weight of the top molding shell 14S, which can have an additional weight 30 placed on the top, as shown diagrammatically in dashed outline in FIG. 4.
The method according to the invention can be implemented as follows.
First the bottom molding shell 14I is varnished, i.e. the coating composition 11' used is applied to its molding surface 15I.
This varnish can be applied in the usual way by dipping into a bath or by centrifuging.
These techniques are well known in themselves and need not be described in more detail here.
Depending on the configuration of the lens blank 10', the varnished molding shell 14I is:
1) either used directly without preliminary treatment,
2) or, especially if the lens blank 10 is precurved:
a) allowed to remain at room temperature for sufficient time for the coating composition 11' on it to be dust-dry, or
b) heated to a temperature above the gel point of the coating composition 11'.
The dried or preheated bottom molding shell 14I is then placed in the ring 17 followed by the ring 19, the lens blank 10' and the top molding shell 14S, with the additional weight 30 if required.
If the lens blank 10' is flat it is at a distance from the molding shell 14I.
If it is precurved it bears against the latter.
Either way, the mold 22 is then placed in the tunnel oven 24.
As it passes through the latter the temperature is increased to polymerize further the coating composition 1' on the bottom molding shell 14I and to initiate thermal sagging of the lens blank 10'.
If the lens blank 10' is flat, as shown here, it therefore comes into contact with the coating composition 11' in the central area of the molding shell 14I, after about 30 minutes (FIG. 6A).
As the temperature of the coating composition 11' is above its gel point, as mentioned above, there is no significant flow of the coating composition 11' towards the edge of the molding shell 14I.
As thermal sagging of the lens blank 10' continues, the lens blank 10' progressively mates with the shape of the molding surface 15I of the molding shell 14I (FIG. 6B) and at the same time polymerization of the protection composition 11' on the latter continues.
To illustrate the invention more clearly there follows an example of its use for a flat lens blank 10' having a diameter D in the order of 80 mm.
I. Preparation of coating composition 11'
The thermosetting coating composition is preferably a polysiloxane type varnish.
361.08 g of glycidoxypropyltrimethoxysilane having formula RSi(OR') 3 (where R=glycidoxypropyl and R'=CH 3 ) was hydrolized in 82.89 g of 0.1N hydrochloric acid.
Hydrolysis continued for 24 hours.
To increase abrasion resistance, 94.55 g of a solution of colloidal silica in methanol was added to the hydrolysate obtained, the colloidal silica content of the solution being 30% and the silica particle diameter being 13 mμm (millimicrons).
1.19 g of aluminium acetylacetonate were then added as catalyst and 66.03 g of ethylcellosolve and 171.55 g of methanol were added as solvent.
0.6 g of FC430 were then added as surfactant.
After complete polymerization the colloidal silica content of the dry extract was in the order of 10% and the RSi O 3/2 content was in the order of 90%.
II. Treatment of molding shells 14I, 14S
The molding shells 14I, 14S, the molding surfaces 15I, 15S of which can have any geometry, for example progressive toroidal or cylindrical geometry, can be of mineral glass subjected to thermal annealing, for example.
Their molding surfaces 15I, 15S were coated with a mold release agent such as dimethyldichlorosilane either by vapor deposition or by application of a mixture in isopropyl alcohol containing 2% by weight of this mold release agent.
Alternatively, the molding shells 14I, 14S can be used as they are.
In this case, however, their molding surfaces 15I, 15S are preferably wiped with acetone to degrease them and render them chemically clean.
III. Application of coating composition 11' to molding shell 14I
This application is done by immersion in a bath, for example.
The bath was held at a temperature of 3° C. to 4° C., the molding shell 14I introduced into it vertically, held in it for 1 minute 25 seconds and removed from it with a dewetting time (i.e. a raising time) of one minute.
Alternatively, however, and as previously mentioned, the coating composition 11' can be applied to the molding shell 14I by centrifuging.
In either case, if the starting lens blank 10' is flat, as here, the molding shell 14I entirely coated, and therefore having a molding surface 15I coated, with a film of coating composition 11', was dried at room temperature until it was dust-dry, i.e. until it had polymerized so that it was no longer tacky.
IV. Heat treatment
The static load applied to the lens blank 10' in the mold 22 into which it had been placed was limited to the weight of the molding shell 14S on top of it, which was 100 g.
The mold 22 was placed directly in the tunnel oven 24, the initial temperature in which was 110° C.
There it underwent the following cycle:
temperature increased from 110° C. to 160° C. in 30 minutes,
temperature maintained at 160° C. for 30 minutes,
temperature increased from 160° C. to 196° C. in 35 minutes,
temperature maintained at 196° C. for 50 minutes,
temperature increased from 196° C. to 203° C. in ten minutes,
temperature reduced from 203° C. to 30° C. in two hours.
V. Characteristics of resulting protection film 11
Thickness: 2.56 μm.
Adherence tests:
A first adherence test was carried out according to French standard AFNOR 76 FNT 30-038, in which results are classified as degree 0 through degree 5.
It entails cutting the protection film 11 into a cross-hatched mesh of incised lines, applying adhesive tape to the cross-hatched protection layer 11 and attempting to pull it off using the tape.
Result: degree 0.
The edges of the cuts remained perfectly smooth and none of the squares thereby was detached.
As a control, a second adherence test of the same type was carried out on an optical lens 10 provided with a protection film 11 and previously immersed in boiling water for 30 minutes.
The results were the same.
Abrasion resistance tests:
BAYER test:
This yielded a value of 3 to 4, substantially the same as that of protection layers 11 obtained by a prior art method.
Steel wool test:
This also yielded a result comparable to that for protection films 11 obtained in the usual way.
Of course, the present invention is not limited to the embodiment specifically described, but encompasses any variant execution thereof.
In particular, the silica content of the colloidal silica suspension used in the coating composition for favoring its abrasion resistance, given as a percentage dry extract relative to the final product, can vary between 0% and 30%, preferably between 10% and 30%.
It is most preferably below 30%, however.
Above 30% cracking of the protection layer can occur, shrinkage of this layer being then too great.
Similarly, the quantity of catalyst used in the composition to render polymerization progressive can be varied.
However, it is usually between 0% and 0.5% by weight, representing a compromise between good abrasion resistance and good adherence.
At 0% adherence is satisfactory but abrasion resistance can be mediocre and beyond 0.5% polymerization is usually too fast for adherence to be satisfactory.
Between 0% and 0.3% by weight of the catalyst is preferably used in the coating composition.
Applications of the invention are naturally not restricted to the treatment of concave-convex ophthalmic lenses, but extend more generally to the treatment of any optical lens, regardless of its profile.
Finally, it goes without saying that both sides of an optical lens can be coated in this way with a protection film. | A method for making a thermoplastic optical lens having at least one side coated with a thermosetting protective film is provided. The method includes steps of applying a thermosetting coating composition to a molding surface of the molding shell, disposing the thermoplastic lens blank in a horizontal position and vertically above the molding shell, heating the lens blank to cause thermal sagging under low static load conditions as the lens blank comes into contact with the coating composition on the molding surface and continuing heating until the lens blank mates with the molding surface. | 1 |
BACKGROUND OF THE INVENTION
The technical scope of the invention is that of projectiles incorporating a sub-calibre penetrator positioned in a full calibre sabot.
The sabot is made of a light material, for example aluminum, and is classically formed of several segments (more often than not, three) which surround the penetrator. The segments are linked together by a band that ensure gas tightness within the gun barrel and one or two retention rings, located to the fore or rear of the sabot, or on a front guiding seat.
The sabot enables the penetrator to be fired from the gun barrel. It releases the penetrator upon exiting the barrel.
The penetrator and the sabot generally incorporate profiles cooperating with each other so as to ensure the axial drive of the penetrator by the sabot when the projectile is being fired. These profiles may comprise helicoidal threading on the penetrator housed in female threading in the sabot or else a succession of teeth and ring-shaped grooves.
Patent FR2666647 describes such a known projectile.
Classical drive profiles are designed so as to supply the sabot with a bearing surface enabling it to transmit the longitudinal thrusting stresses, created by the action of the powder gases, to the penetrator. This profile is thus essentially dimensioned to withstand shearing.
Classical profiles are either so-called ISO profiles (in which the teeth are trapezoidal and symmetrical with respect to the transversal plane) or artillery profiles (in which the teeth are not symmetrical but have a rear flank strongly inclined with respect to the penetrator's axis).
When a projectile incorporating a drive profile of a known type moves through the barrel of a weapon, it is subjected to a certain number of transversal disturbances caused by the curvature of the barrel, pressure dissymmetry and the projectile's own vibrations which cause flexions in the penetrator.
The three sabot segments thus work independently of each other and at any given moment there are only one or two segments supporting the penetrator in flexion. The sabot, therefore, does not help the penetrator to withstand flexion.
These segment movements are all the greater in that the penetrator is long (L/D elongation over 25).
Moreover, through the combined action of its inertia, the pressure stresses and traversal accelerations, the sabot can start to open at its front pocket. In this case, the support it gives to the penetrator is reduced.
Deficiencies in the support of the penetrator lead to firing obliquities and a loss of accuracy.
Furthermore, when the front of the sabot opens like this, the guiding seats create greater friction with the barrel, thus aggravating its wear.
SUMMARY OF THE INVENTION
The aim of the invention is to propose a projectile allowing such drawbacks to be overcome. The invention also relates to the penetrator and sabot constituting such a projectile.
Thus, the projectile according to the invention incorporates means at the drive interface of the penetrator and the sabot, which also provide radial retention for the sabot segments.
This results in better flexion-resistance of the sabot and improved retention of the penetrator, and thus leads to an enhancement of firing accuracy. This increase in transversal rigidity also enables the sabot's mass to be reduced.
The invention thus relates to a sub-calibre projectile incorporating a penetrator and a sabot formed of several segments, the penetrator and sabot incorporating profiles that cooperate with one another so as to ensure the axial drive of the penetrator by the sabot when the projectile is being fired, such projectile wherein there is axial play between the profile on the sabot and that on the penetrator so as to enable a limited relative axial displacement of the sabot with respect to the penetrator, means being provided to ensure the radial locking of the sabot segments by the penetrator in the foremost position of the sabot with respect to the penetrator, this locking no longer being ensured in the most rearward position of the sabot with respect to the penetrator.
According to one embodiment of the invention, the profiles on the sabot and on the penetrator are formed of teeth and grooves, the teeth and grooves being ring-shaped or formed by helicoidal threading, a rear face of the teeth on the penetrator having a concave conical profile cooperating during firing with a convex conical profile made on a front face of the teeth on the sabot, these profiles constituting means to ensure the radial locking of the sabot segments with respect to the penetrator during firing.
According to one embodiment, a front face of the teeth on the penetrator has a convex conical profile arranged during firing at a distance from a concave conical profile made on a rear face of the teeth on the sabot, these profiles being additionally in contact with one another upon exiting the gun barrel when the sabot recoils with respect to the penetrator, the contact between these profiles enabling the sabot segments to be kept away from the penetrator.
According to another embodiment, a front face of the teeth on the penetrator has a concave profile arranged during firing at a distance from a convex profile made on a rear face of the teeth on the sabot, these profiles coming into contact with each other upon exiting the gun barrel when the sabot recoils with respect to the penetrator, the shape of the profiles being chosen so as to keep the sabot segments away from the penetrator with a starting movement of the segments that is substantially parallel to the penetrator.
According to another embodiment, the locking means comprise a specific tooth located to the fore of the grooves or threading on the penetrator, such tooth incorporating a concave conical profile on its rear face cooperating during firing with a convex conical profile made on a front face of a tooth on the sabot so as to ensure the radial locking of the sabot segments with respect to the penetrator during firing.
The invention also relates to a sub-calibre penetrator intended to be incorporated into a projectile, wherein it incorporates an external profile incorporating teeth separated by grooves, teeth and grooves being ring-shaped or formed by helicoidal threading, a rear face of the teeth having a concave conical profile.
A front face of the penetrator's teeth may have a convex conical profile.
Alternatively, a front face of the penetrator's teeth may have a concave profile.
The penetrator may incorporate an external profile incorporating teeth separated by grooves, teeth and grooves being ring-shaped or formed by helicoidal threading, one specific tooth being positioned to the fore of the teeth or grooves of the penetrator, such tooth incorporating a concave conical profile at its rear face.
The invention also relates to a sabot intended to be incorporated into a projectile, such sabot wherein it incorporates an internal profile intended to accommodate a penetrator and incorporating teeth separated by grooves, teeth and grooves being ring-shaped or formed by helicoidal threading, one front face of the teeth having a convex conical profile.
A rear face of the sabot teeth may have a concave conical profile.
Alternatively, a rear face of the sabot teeth may have a convex profile.
The sabot may incorporate an internal profile intended to accommodate the penetrator incorporating teeth separated by grooves, teeth and grooves being ring-shaped or formed by helicoidal threading, the front face of the tooth positioned the foremost incorporating a convex conical profile.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will become more apparent from the following description of the different embodiments, such description being made in reference to the appended drawings, in which:
FIG. 1 shows a schematic longitudinal section of a sabot for a discarding-sabot projectile according to prior art or according to the invention,
FIGS. 2 a and 2 b show an enlarged view of the linking profiles according to prior art, FIG. 2 a showing an ISO profile and FIG. 2 b an artillery profile,
FIG. 3 a shows an enlargement of a first embodiment of a drive profile implemented on a projectile according to the invention, this Figure shows how the sabot profile cooperates with that of the penetrator when the projectile is being fired,
FIG. 3 b shows how the sabot profile cooperates with that of the penetrator upon exiting the barrel,
FIG. 4 a shows an enlargement of a second embodiment of a drive profile implemented on a projectile according to the invention, this Figure shows how the sabot profile cooperates with that of the penetrator when the projectile is being fired,
FIG. 4 b shows a first stage in the cooperation of the sabot profile with that of the penetrator upon exiting the gun barrel,
FIG. 4 c shows a second stage in the cooperation of the sabot profile with that of the penetrator upon exiting the gun barrel,
FIG. 5 a shows an enlargement of another embodiment of a drive profile implemented on a projectile according to the invention, this Figure shows how the sabot profile cooperates with that of the penetrator when the projectile is being fired,
FIG. 5 b shows how the sabot profile cooperates with that of the penetrator upon exiting the gun barrel.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
With reference to FIG. 1 , a projectile 1 according to the invention or according to prior art classically comprises a penetrator 2 and a sabot 3 formed of several segments.
The penetrator has a fin 4 at its rear part and the different sabot segments are made integral with each other by a band 5 and a front ring 6 .
The penetrator 2 is housed in a bore 7 in the sabot 3 . This bore incorporates a profile (not visible in FIG. 1 ) which cooperates with a profile of the external cylindrical surface of the penetrator 2 so as to ensure the axial drive of the penetrator by the sabot when the projectile is being fired. The oval zone marked Z in FIG. 1 is enlarged in FIGS. 2 a to 4 c , zone Z 1 is furthermore enlarged in FIGS. 5 a and 5 b , these zones usefully highlighting the differences between the linking profiles for projectiles according to prior art and for projectiles according to the invention.
FIGS. 2 a and 2 b show an enlargement and longitudinal section of zone Z for the linking profiles according to prior art.
These profiles comprise a succession of teeth separated by grooves. The sabot teeth are marked D 3 and the sabot grooves G 3 , the penetrator teeth are marked D 2 and the penetrator grooves G 2 .
For the ISO profile shown in FIG. 2 a , the teeth D 2 , D 3 and the grooves G 2 and G 3 have a trapezoid-shaped section, all are symmetrical with respect to a plane 10 perpendicular to the penetrator's axis and passing through the tip of the tooth or groove under consideration.
Thus, the front 8 and rear 9 flanks of each tooth (or groove) form an equal angle with the direction of the bore 7 .
FIG. 2 b shows another known drive profile, the artillery profile. In this profile, the teeth and grooves are not symmetrical. In particular, the teeth D 2 of the penetrator incorporate a rear flank 9 that is strongly inclined with respect to the direction of the bore 7 .
Known profiles are either constituted by helicoidal threading on the penetrator cooperating with female threading on the sabot, or by a succession of ring-shaped teeth and grooves.
FIGS. 3 a and 3 b show an enlargement of zone Z in FIG. 1 for a projectile according to a first embodiment of the invention.
According to this embodiment, each rear face 11 of the teeth D 2 on the penetrator 2 has a concave conical profile which is defined so as to be able to cooperate during firing with a convex conical profile made on each front face 12 of the teeth D 3 on the sabot 3 .
This cooperation ensures the radial locking of the segments of the sabot 3 with respect to the penetrator 2 during firing.
Thus, the segments are no longer separated from the penetrator inside the barrel and thus provide support for it and reduce flexion.
Because of the orientation of the conical locking faces ( 11 , 12 ), the retention of the sabot 3 segments is all the more rigid in that the propellant stress is high. Locking the sabot segments improves the cohesion of the projectile. The sabot assembly may thus work in flexion thereby making it possible to lighten the sabot. Indeed, the thicknesses of the sabot may be reduced since they were partially selected to improve flexion-resistance. This reduction in mass may be of around 5%.
The half angle at the tip α ( FIG. 3 b ) of the conical surfaces of faces 11 and 12 will be selected at around 70° to 85°.
The longitudinal play J will be chosen taking into account the deviations in machining tolerances for the teeth (or threading) and thus taking into account the maximal thermal dilations.
This play enables a limited relative axial displacement of the sabot 3 with respect to the penetrator 2 .
Such an arrangement is intended to allow the sabot and penetrator to separate upon exiting the gun barrel.
The projectile functions as follows.
During firing, the pressure exerted on the rear of the sabot drives it forwards. There is thus a relative displacement of the sabot with respect to the penetrator in direction F (see FIG. 3 a ). This displacement brings the conical profile of the front face 12 of teeth D 3 of the sabot into contact with the matching profile of the rear face 11 of the penetrator's teeth.
The sabot 3 segments are thus radially locked around the penetrator 2 . This locking is ensured for as long as the gas pressure acts on the rear of the sabot, that is to say, for all the time that the projectile is inside the gun barrel.
Upon exiting the gun barrel, the pressure exerted to the rear of the sabot suddenly drops. Moreover, the relative wind created by the displacement of the projectile through the air tends to oppose the displacement of the sabot. The sabot 3 thus moves backwards with respect to the penetrator 2 in direction F′ (see FIG. 3 b ).
This displacement unlocks the sabot-penetrator link. The sabot 3 thus released is able to separate from the penetrator 2 according to classical opening mechanisms.
Each front face 13 of the teeth D 2 on the penetrator 2 has a convex conical profile which comes into contact, when the sabot recoils, with a concave conical profile made on each rear face 14 of the teeth D 3 on the sabot 3 .
The cooperation of these conical profiles, in conjunction with the axial displacement, ensures a relative radial displacement of the sabot 3 segments with respect to the penetrator 2 . To facilitate this separation, the half angle at the tip β ( FIG. 3 b ) of the cones of faces 13 and 14 will be of around 45° to 60°.
The profiles will be easily machined using a tool having a shape which corresponds to the shape of the groove to be machined.
FIGS. 4 a , 4 b and 4 c show an enlargement of zone Z in FIG. 1 for a projectile according to a second embodiment of the invention.
Once again, teeth D 2 and D 3 on the penetrator or sabot have faces 11 and 12 that cooperate so as to radially lock the sabot segments with respect to the penetrator when the projectile is being fired (displacement of the sabot forwards with respect to the penetrator, in direction F shown in FIG. 4 a ).
In accordance with this particular embodiment, each front face 13 of teeth D 2 on the penetrator 2 has a concave profile intended to cooperate upon exiting the gun barrel with a convex profile on each rear face 14 of teeth D 3 on the sabot 3 .
Moreover, these profiles are of a shape chosen so as to promote a radial distancing of the sabot segments during the sabot/penetrator separation process.
Such an arrangement promotes a sabot/penetrator separation with an initial movement of the segments that is substantially parallel to the penetrator. The risk of disturbance or shocks on the penetrator caused by the sabot when opening is thus minimized.
So as to promote thereby the radial displacement of the sabot segments, the profile of the front face 13 of teeth D 2 will be defined such that the tangent T to this profile ( FIG. 4 b ) is close to a radial direction to the penetrator 2 (angle γ of the tangent T with a radial plane 10 of around 5° to 10°).
Once again, the profiles will be easily machined using tooling of a shape matching the shape of the groove to be machined.
FIGS. 5 a and 5 b show an enlargement of the zone Z 1 of FIG. 1 , such zone positioned at the front part of a projectile according to a third embodiment of the invention.
In this embodiment, teeth D 2 , D 3 and grooves G 2 , G 3 of the penetrator and sabot have a classical ISO profile analogous to that described previously with reference to FIG. 2 a (but they could alternatively have an artillery profile such as those in FIG. 2 b ). The profile may be constituted either by threading or by a succession of ring-shaped teeth and grooves.
According to the invention, play J is provided that enables an axial displacement of the penetrator 2 with respect to the sabot 3 .
According to this particular embodiment, a specific tooth 15 is located forward of the grooves G 2 and teeth D 2 of the penetrator 2 . This tooth incorporates a concave conical profile on its rear face 16 which, during firing, cooperates with a convex conical profile 17 made on a front face of a tooth 18 on the sabot 3 .
The half-angle at the tip α ( FIG. 5 b ) of the conical surfaces of faces 16 and 17 will be chosen at around 70° to 85°.
This cooperation of the profiles with respect to tooth 15 provides radial locking for the sabot 3 segments with respect to the penetrator 2 during firing.
Functioning is analogous to that described above for the previous embodiments. During firing, the pressure exerted at the rear of the sabot 3 pushes it forwards. There is a relative displacement of the sabot with respect to the penetrator in direction F ( FIG. 5 a ) and tooth 18 is locked by tooth 15 .
Contrary to the previous embodiments, here only the front part of the sabot 3 is locked. It is therefore unable to remove itself from the penetrator during the cannon phase despite the effects of both acceleration and air pressure. The penetrator is well supported and premature wear of the guiding seats 6 further to the spreading of the sabot 3 segments is thus avoided.
Locking is ensured for as long as the gas pressure acts on the rear of the sabot, that is to say, for the full time the projectile is in the gun barrel.
Upon exiting the barrel, the pressure exerted upon the rear of the sabot suddenly drops. The sabot, pushed by the relative wind created by the flight of the projectile, is displaced backwards with respect to the penetrator in direction F′ ( FIG. 5 b ).
This displacement ensures the unlocking of the sabot penetrator link. The released sabot is able to separate from the penetrator following the usual opening mechanisms. | A sub-caliber projectile incorporating a penetrator and a sabot formed of several segments, the penetrator and sabot incorporating profiles that cooperate with one another so as to ensure the axial drive of the penetrator by the sabot when the projectile is being fired, such projectile wherein there is axial play (J) between the profile on the sabot and that on the penetrator so as to enable a limited relative axial displacement of the sabot with respect to the penetrator, means being provided to ensure the radial locking of the sabot segments by the penetrator in the foremost position of the sabot with respect to the penetrator, this locking no longer being ensured in the rearmost position of the sabot with respect to the penetrator. | 5 |
RELATED APPLICATION
This application is a divisional of application Ser. No. 08/331,711, filed Oct. 31, 1994 which is a continuation-in-part of U.S. patent application Ser. No. 08/147,254 entitled "A Method for Communicating in a Wireless Communication System", filed on Nov. 1, 1993 now U.S. Pat. No. 5,603,081, which disclosure is incorporated here by reference.
BACKGROUND
The present invention relates generally to radiocommunication systems having control channels and, more particularly, to the location of digital control channels in such systems.
Radiocommunication systems have traditionally been analog in nature. The rapid growth of radiocommunication systems, however, has compelled system designers to search for ways in which system capacity can be increased without reducing communication quality beyond consumer tolerance thresholds. One way in which increased capacity can be provided is by changing from analog to digital communication techniques. In North America, this change was implemented by transitioning from the analog AMPS system to a digital system (D-AMPS) which is now standardized as IS-54B.
Since a large consumer base having equipment that operated only in the analog domain existed prior to the introduction of digital techniques, a dual-mode (analog and digital) standard was adopted in IS-54B so that analog compatibility was provided in tandem with digital communication capability. For example, the IS-54B standard provides for both analog and digital traffic channels, wherein the system operator can replace analog traffic channels with digital traffic channels, and vice-versa, in a dynamic manner to accommodate fluctuating traffic patterns among analog and digital users.
In addition to traffic channels, radiocommunication systems also provide control channels which are used to carry call setup data messages between base stations and mobile stations. According to IS-54B, for example, there are 21 dedicated analog control channels which are assigned to fixed frequencies for each of the A and B carriers. These analog control channels are termed "dedicated" since they are always found at the same frequency and, therefore, can be readily located by the mobile stations which need to monitor the data which is transmitted thereon.
For example, when in the idle state (i.e., turned on but not in use), a mobile station in an IS-54B system tunes to and then continuously monitors the strongest control channel at its known frequency (generally, the control channel of the cell in which the mobile station is located at that moment) and may receive or initiate a telephone call through the corresponding base station. When moving between cells while in the idle state, the mobile station will eventually "lose" radio connection on the control channel of the "old" cell and tune to the control channel of the "new" cell. The initial tuning to, and the change of, control channel are both accomplished automatically by scanning all the control channels at their known frequencies in operation in the cellular system to find the "best" control channel. When a control channel with good reception quality is found, the mobile station remains tuned to this channel until the quality deteriorates again. In this manner, all mobile stations are nearly always "in touch" with the system.
As such hybrid systems mature, it is anticipated that the number of analog users will diminish and the number of digital users will increase. Eventually all of the analog traffic channels will probably be replaced by digital traffic channels. When that occurs, less expensive digital-only mobile units can replace the current dual-mode units. However, such digital-only mobile units would be unable to scan the analog control channels currently provided in the IS-54B system.
Accordingly, it is desirable to provide digital control channels to radiocommunication systems which support digital technology, such as that described by IS-54B. In addition to compatibility issues, digital control channels are also desirable for other reasons described in the above-identified application, for example an enhanced sleep mode for mobile units which results in longer battery life. Whereas IS-54B provides dedicated control channels, more flexibility is desirable in assigning the number of control channels and the frequencies for these control channels to optimize system capacity and to support hierarchical cell structures, i.e., microcells, picocells, etc. If, however, the digital control channels are not located on known frequencies, the question arises as to how the remote units will be able to locate these control channels for monitoring.
One conventional radiocommunication system used in Europe, known as the GSM, is already an all-digital system. In this system, the mobile unit simply scans through all of the available channels until it identifies a digital control channel. This location technique, however, is too slow for systems having a large number of channels. Moreover, the problem of locating a digital control channel after call termination is exacerbated by handoffs of mobile units that move from cell to cell, since a mobile unit cannot then even use its knowledge of the location of the control channel which it had been monitoring prior to the call.
SUMMARY
These and other drawbacks and limitations of conventional systems and methods are overcome according to the present invention wherein digital control channel location is expedited by, for example, prescribing a search pattern based on a relative likelihood of finding a digital control channel on a particular channel or group of channels and providing digital control channel location information on other channels.
According to exemplary embodiments of the present invention, channels are grouped into probability blocks which are ranked in accordance with the relative likelihood of finding the digital control channel in each block. A mobile unit can then look for a digital control channel within a highest ranked probability block, followed by a second highest ranked probability block and so on, until a digital control channel is located.
According to other exemplary embodiments of the present invention, information can be provided on other channels, such as traffic channels or analog control channels, which points the mobile station to a particular channel on which a digital control channel can be found or a group of channels within which a digital control channel can be found. In this way, the location process is expedited when compared with sequential channel searching.
According to still further exemplary embodiments of the present invention, a mobile unit can receive information about digital control channel location during call termination. In this way, the mobile unit need not repeat the process of trying to determine where a digital control channel is located immediately after call termination, which is particularly useful in situations where the mobile moved to a new cell during the call.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing, and other, objects, features and advantages of the present invention will be more readily understood upon reading the following detailed description in conjunction with the drawings in which:
FIGS. 1(a)-1(d) are tables which show exemplary probability block schemes according to the present invention;
FIG. 2(a) illustrates an exemplary downlink digital traffic channel according to the present invention;
FIG. 2(b) illustrates a conventional uplink digital traffic channel;
FIG. 2(c) illustrates an exemplary uplink digital control channel slot format according to the present invention;
FIG. 2(d) illustrates an exemplary downlink digital control channel slot format according to the present invention;
FIG. 2(e) is a flow chart illustrating an exemplary technique for distinguishing between traffic channels and control channels.
FIG. 3 is a flow chart which depicts an exemplary method for locating a digital control channel according to the present invention;
FIG. 4(a) is a table which illustrates an exemplary message format according to the present invention;
FIG. 4(b) is a table which illustrates an entry of the table of FIG. 4(a) in more detail; and
FIG. 5 is a block diagram of an exemplary radio communication system according to the present invention.
DETAILED DESCRIPTION
According to exemplary embodiments of the present invention, several techniques can be used, either together or individually, to expedite the acquisition of a digital control channel by the mobile station.
One technique which can be used to aid the mobile in searching for a digital control channel is to group the available frequencies into blocks which are assigned different probabilities that reflect the relative likelihood of finding a digital control channel in each block. In this manner, the time required for service acquisition by the mobile station may be significantly decreased. The two tables depicted in FIG. 1(a) and 1(b) are examples of how the channels in the A-Band and B-Band, respectively, can be assigned different relative probabilities for supporting digital control channel acquisition. Similarly, FIG. 1(c) and 1(d) present another such example. This technique can be used by a mobile station as a starting point for digital control channel location, for example, before it has received any digital control channel locator information (described below). Once a mobile station has received digital control channel locator information, it can use this information in lieu of the channel block probability scheme described herein.
Another technique for aiding the mobile in its search for a digital control channel is to place digital control channel location information on channels other than the digital control channel so that if the mobile reads such a channel while searching for the DCC, its search can be expedited. For example, the digital control channel locator (DL) is a parameter which can be placed on the digital traffic channel and that provides information to assist a mobile station in finding a digital control channel. The DL identifies for the mobile station the RF channel which carries a digital control channel. Depending upon the number of bits available to express the DL and the number of channels in the system, the DL may uniquely identify the channel on which a digital control channel resides or it may narrow the search to some subset of the possible channels. For example, if a 7-bit DL is provided, then DL values 1, 2, 3. . . 127 would be mapped to channel numbers 1-8, 9-16, 17-24,. . .1009-1016, respectively. Thus, for example, if a digital control channel occupies channel number 10, then a DL value of 2 would be sent on the digital traffic channels in the same cell. The DL value of zero does not provide any digital control channel location information, but instead indicates that no DL information is being provided by the system.
Once DL values are determined, they are encoded to form the CDL which is sent on the digital traffic channel in, for example, bit positions 314 to 324 in a IDMA slot. This is illustrated by the exemplary digital traffic channel base-to-mobile slot format shown in FIG. 2(a). The numbers below the data fields indicate the number of bits therein. Fields other than the CDL are those found in conventional IS-54B base-to-mobile traffic channel slots and the interested reader is referred thereto for additional information. Exemplary uplink digital traffic channel, uplink digital control channel, and downlink digital control channel slot formats are illustrated as FIGS. 2(b), 2(c) and 2(d), respectively, for reference and later discussion. Those skilled in the art will appreciate that other bit positions can be used for the CDL field in the slot, however, this particular position is advantageous in that it corresponds to the previously unused RSVD field of the downlink digital traffic channel slots of IS-54B. In this way, changes to the IS-54B air interface are minimized. These RSVD bits are defaulted to zeros in the IS-54B specification, which conveniently indicates when no location information has been provided. Another possibility would be to provide the DL into the Layer 2 frame of the DTC.
According to exemplary embodiments of the present invention, all channel numbers are valid candidates for digital control channel assignment. Considering that the DL does not necessarily uniquely identify any particular channel number, it is desirable that a priority scheme be established which can be used to search for digital control channel within each channel block identified by the DL. A mobile station receiving the DL value associated with a particular channel block will not automatically search all channels, but will instead search for a digital control channel in this block in accordance with this priority scheme. Thus, for example, for a DL value of 1, a mobile station could examine channel numbers 8 through 1 starting with channel 8 then 7, etc., in an attempt to find the digital control channel.
Having described exemplary techniques which can be used to expedite the location of a digital control channel, other exemplary embodiments of the present invention will now be described wherein these techniques are applied in various situations. For example, and with reference to the flow chart of FIG. 3, suppose that a mobile station is seeking a digital control channel on the A-Band carrier of an IS-54 system. As shown at block 10, the mobile will first examine, assuming that no other information is available in the mobile station, the channels within the highest ranked probability block, for example, block 1 having channel numbers 1-26 in FIG. 1(a). Within this block of channels, the mobile will select a first channel to read based on some predetermined criteria. For example, as described in block 20, this criteria can be the measured signal strength of the channels within the probability block. Alternately, the channels could be read in numbered order within the block. Thus, the mobile measures the signal strength (RSSI) of channels 1-26 and ranks them in order from strongest to weakest. The highest signal strength channel, denoted channel `X` for this discussion, is then selected for reading at block 30. If this selected channel `X` is identified as an analog channel at block 40, i.e., either an analog control channel or an analog traffic channel, then the flow returns to block 30 where the next highest ranked channel is selected for reading. If, on the other hand, channel `X` is a digital channel, then the flow proceeds to decision block 50 wherein the digital channel is identified as being either a control channel or a traffic channel. This identification can be performed in a variety of ways.
As an example for distinguishing between a digital traffic channel and a digital control channel, the IS-54 standard will again be used as an illustrative reference. Although the IS-54B digital traffic channel and digital control channel downlink slot format have structural commonality, as seen in FIGS. 2(a) and 2(c), there are also certain differences which allow for distinguishing a digital control channel from a digital traffic channel. First, because of the differences in the channel coding of the digital verification color code (DVCC) and superframe (SFP) fields, there are always 4 bits out of 12 which are different in every pair of CDVCC and CSFP codewords regardless of which CDVCC or CSFP codeword is transmitted by a base station (bit errors introduced due to radio channel impairments, however, may change the extent to which transmitted codewords differ once they are received by a mobile station). More specifically, the four check bits of the SCFP are inverted relative to the check bits of the CDVCC. Secondly, the CDVCC content is fixed from slot to slot on a digital traffic channel whereas the content of the CSFP changes in a predictable fashion from slot to slot on a digital control channel.
FIG. 2(e) illustates an exemplary technique for distinguishing between traffic channels and control channels using the differences illustrated in FIG. 2(a) through 2(c). At step 2, a field is broadcast on a channel that includes either CDVCC or CSFP depending upon whether the channel is a digital traffic or a digital control channel, respectively. At step 4, the field is received at a mobile station. Then, the field of interest is evaluated at decision block 6 to determine whether the check bits in this field are inverted relative to those expected in a digital traffic channel. If so, then the flow proceeds to block 7 wherein the channel is characterized as a digital control channel. Otherwise, the flow proceeds to block 8 where the channel is characterized as a digital traffic channel.
Another distinction which could be used is that the channel coding and interleaving employed on a digital traffic channel is different from that employed on a digital control channel regardless of the DTC service (speech or FACCH). For example, the digital traffic channel might use 1/2 rate coding while the digital control channel uses 1/4 rate coding. Moreover, the IS-54B SACCH and RESERVED fields have different functionality on a digital control channel. The actual function of each of the fields illustrated in FIGS. 2(a)-2(d) is not germane to the present discussion, however, for a more detailed explanation of the functionality of these fields reference is made to the above-incorporated application.
If channel `X` is a digital control channel then the location process has accomplished its goal and the flow proceeds to the END block. If, on the other hand, channel `X` is a digital traffic channel, then the process moves to block 60 wherein it is determined whether or not the digital traffic channel includes digital control channel location information, such as the aforedescribed DL field. If not, then the mobile reads another channel and the flow moves back to block 30. If so, then this information is used to find the digital control channel at block 70.
As an alternative to the foregoing probability block scheme, in hybrid systems where analog control channels still exist, such as the IS-54B, digital location information can be placed on these channels. For example, digital control channel information can be placed on each of the 21 dedicated analog control channels found on both carriers in IS-54B. Then, a mobile station can first tune to the strongest available analog control channel, determine where the digital control channel for that cell is located, and then tune directly to the digital control channel.
According to another exemplary embodiment of the present invention, information regarding digital control channel location can also be provided to a mobile station when that mobile station undergoes a call termination. One of the messages which is typically sent from a base station to a mobile station in connection with the termination of a call is a RELEASE message which informs the mobile search for a DCC on an indicated frequency. By placing information regarding the location of a digital control channel associated with the cell in which the mobile station is located at the time of call termination on the RELEASE message, the mobile station need not then go through any procedures for locating a new digital control channel. In this way, the mobile station will have knowledge of digital control channel location regardless of whether it has been handed off or not during a previous connection.
As an example, FIGS. 4(a) and 4(b) illustrate message formats by which information can be provided to a mobile station in the RELEASE message for finding a digital control channel. FIG. 4(a) shows an overview of an exemplary RELEASE message format which includes a Type O (optional) DCC information field having 29 bits. An exemplary format for these 29 bits is illustrated in FIG. 4(b). Therein, the "Parameter Type" field identifies the field as a DCC information field. The "Number of Values" field indicates how many information elements are in the message. The "Channel" field identifies the frequency on which a control channel can be found and the "DVCC field" provides digital verification color code information. Of course those skilled in the art will appreciate that the foregoing signal format is only an exemplary, illustrative manner in which digital control channel location information can be provided and that other formats can be used.
FIG. 5 represents a block diagram of an exemplary cellular mobile radiotelephone system according to one embodiment of the present invention which can be used to implement the foregoing. The system shows an exemplary base station 110 and a mobile 120. The base station includes a control and processing unit 130 which is connected to the MSC 140 which in turn is connected to the public switched telephone network (not shown).
The base station 110 for a cell includes a plurality of voice channels handled by voice channel transceiver 150 which is controlled by the control and processing unit 130. Also, each base station includes a control channel transceiver 160 which may be capable of handling more than one control channel. The control channel transceiver 160 is controlled by the control and processing unit 130. The control channel transceiver 160 broadcasts control information over the control channel of the base station or cell to mobiles locked to that control channel. The voice channel transceiver handles the traffic or voice channels which can include digital control channel location information as described previously.
When the mobile 120 first enters the idle mode, it periodically scans the control channels of base stations like base station 110 to determine which cell to lock on or camp to. The mobile 120 receives the absolute and relative information broadcasted on a control channel at its voice and control channel transceiver 170. Then, the processing unit 180 evaluates the received control channel information which includes the characteristics of the candidate cells and determines which cell the mobile should lock to. The received control channel information not only includes absolute information concerning the cell with which it is associated, but also contains relative information concerning other cells proximate to the cell with which the control channel is associated. These adjacent cells are periodically scanned while monitoring the primary control channel to determine if there is a more suitable candidate. Additional information relating to specifics of mobile and base station implementations can be found in copending U.S. patent application Ser. No. 07/967,027 entitled "Multi-Mode Signal Processing" filed on Oct. 27, 1992 to P. Dent and B. Ekelund, which disclosure is incorporated here by reference.
The above-described exemplary embodiments are intended to be illustrative in all respects, rather than restrictive, of the present invention. Although the foregoing exemplary embodiments have been described in terms of base and mobile stations, the present invention can be applied to any radiocommunication system. For example, satellites could transmit and receive data in communication with remote devices, including portable units, PCS devices, personal digital assistants, etc.
Thus the present invention is capable of many variations in detailed implementation that can be derived from the description contained herein by a person skilled in the art. All such variations and modifications are considered to be within the scope and spirit of the present invention as defined by the following claims. | A method and system for locating control channels, particularly digital control channels, are described. By grouping the channels which are candidates for carrying supervisory messages in blocks indicative of their relative likelihood for being used as control channels, a mobile station can begin its search for a control channel with channels which are most likely to actually be control channels. Placing location information on other channels allows the mobile station to be redirected to a control channel when it reads one of these other channels. Similarly, by placing information describing the location of a control channel in a message associated with handoff, a mobile station avoids the necessity of having to relocate a new control channel associated with the base station to which the mobile has been handed off. | 8 |
CLAIM OF PRIORITY
This application is a continuation of U.S. patent application Ser. No. 12/361,242, filed Jan. 28, 2009, which is a continuation of U.S. patent application Ser. No. 10/971,455, filed Oct. 22, 2004, now U.S. Pat. No. 7,484,322, the entire disclosures which are incorporated by reference herein.
FIELD OF THE INVENTION
This invention relates generally to a reduction system for removing soil to expose underground utilities (such as electrical and cable services, water and sewage services, etc.), and more particularly to a system for removing materials from the ground and backfilling the area.
BACKGROUND OF THE INVENTION
With the increased use of underground utilities, it has become more critical to locate and verify the placement of buried utilities before installation of additional underground utilities or before other excavation or digging work is performed. Conventional digging and excavation methods such as shovels, post hole diggers, powered excavators, and backhoes may be limited in their use in locating buried utilities as they may tend to cut, break, or otherwise damage the lines during use.
Devices have been previously developed to create holes in the ground to non-destructively expose underground utilities to view. One design uses high pressure air delivered through a tool to loosen soil and a vacuum system to vacuum away the dirt after it is loosened to form a hole. Another system uses high pressure water delivered by a tool to soften the soil and create a soil/water slurry mixture. The tool is provided with a vacuum system for vacuuming the slurry away.
SUMMARY OF THE INVENTION
The present invention recognizes and addresses disadvantages of prior art constructions and methods, and it is an object of the present invention to provide an improved drilling and backfill system. This and other objects may be achieved by a mobile digging and backfill system for removing and collecting material above a buried utility. The system comprises a mobile chassis, a collection tank mounted to the chassis, a water pump mounted to the chassis for delivering a pressurized liquid flow against the material for loosening the material at a location, a vacuum pump connected to the collection tank so that an air stream created by the vacuum pump draws the material and the fluid from the location into the collection tank, and at least one backfill reservoir mounted to the chassis for carrying backfill for placement at the location.
In another embodiment, a mobile digging and backfill system for removing and collecting material comprises a mobile digging and backfill system for removing and collecting material. The system has a mobile chassis, a collection tank moveably mounted to the chassis, and a digging tool comprising at least one nozzle and a vacuum passage proximate the nozzle. A water pump mounted on the chassis has an output connected to the nozzle for delivering a pressurized liquid flow against the material for loosening the material at a location. A vacuum pump mounted on the chassis has an input connected to the collection tank so that an air stream created by the vacuum pump draws the material and the fluid from the location into the collection tank. A motor mounted to the chassis and is in driving engagement with the water pump and said vacuum pump. A first backfill reservoir is moveably mounted on the chassis for carrying backfill for placement at the location.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and enabling disclosure of the present invention, including the best mode thereof directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
FIG. 1 is a perspective view of a drilling and backfill system constructed in accordance with one embodiment of the present invention;
FIG. 2 is a perspective view of a key hole drill for use with the drilling and backfill system of FIG. 1 ;
FIG. 3 is a perspective view of a reduction tool for use with the drilling and backfill system of FIG. 1 ;
FIG. 4 is bottom view of the reduction tool shown in FIG. 3 ;
FIG. 5 is a partial perspective view of the reduction tool of FIG. 3 in use digging a hole;
FIG. 6 is a perspective view of a key hole drilling tool base for use with the key hole drill of FIG. 2 ;
FIG. 6A is a bottom perspective view of the tool base shown in FIG. 6 ;
FIG. 7 is a perspective view of the reduction tool of FIG. 3 in use digging the hole;
FIG. 8 is a perspective view of the drilling and backfill system of FIG. 1 , showing the hole being backfilled;
FIG. 9 is a perspective view of the drilling and backfill system of FIG. 1 , showing the hole being tamped; and
FIG. 10 is a schematic view of the hydraulic, electric, water, and vacuum systems of the drilling and backfill system of FIG. 1 .
Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention.
DETAILED DESCRIPTION
Reference will now be made in detail to presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope and spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
Referring to FIG. 1 , a drilling and backfill system 10 generally includes a water reservoir tank 12 , a collection tank 14 , a motor 16 , a drilling apparatus 18 , and back fill reservoirs 20 and 22 , all mounted on a mobile chassis 24 , which is, in this embodiment, in the form of a trailer. Trailer 24 includes four wheels 38 (only three of which are shown in FIG. 1 ) and a draw bar and hitch 40 . Drilling and backfill system 10 generally mounts on a platform 42 , which is part of trailer 24 . It should be understood that while drill and backfill system 10 is illustrated mounted on a trailer having a platform, the system may also be mounted on the chassis of a vehicle such as a truck or car. Further, a chassis may comprise any frame, platform or bed to which the system components may be mounted and that can be moved by a motorized vehicle such as a car, truck, or skid steer. It should be understood that the components of the system may be either directly mounted to the chassis or indirectly mounted to the chassis through connections with other system components.
The connection of the various components of system 10 is best illustrated in FIG. 10 . Motor 16 is mounted on a forward end of trailer 24 and provides electricity to power two electric hydraulic pumps 30 and 172 , and it also drives both a water pump 26 and a vacuum pump 28 by belts (not shown). Motor 16 is preferably a gas or diesel engine, although it should be understood that an electric motor or other motive means could also be used. In one preferred embodiment, motor 16 is a thirty horsepower diesel engine, such as Model No. V1505 manufactured by Kubota Engine division of Japan, or a twenty-five horsepower gasoline engine such as Model Command PRO CH25S manufactured by Kohler Engines. The speed of motor 16 may be varied between high and low by a wireless keypad transmitter 108 that transmits motor speed control to a receiver 110 connected to the throttle of motor 16 .
The water system will now be described with reference to FIG. 10 . Water reservoir tank 12 connects to water pump 26 , which includes a low pressure inlet 44 and a high pressure outlet 46 . In the illustrated embodiment, water pump 26 can be any of a variety of suitable pumps that delivers between 3,000 and 4,000 lbs/in 2 at a flow rate of approximately five gallons per minute. In one preferred embodiment, water pump 26 is a Model No. TS2021 pump manufactured by General Pump. Water tank 12 includes an outlet 50 that connects to a strainer 52 through a valve 54 . The output of strainer 52 connects to the low pressure side of water pump 26 via a hose 48 . A check valve 56 is placed inline intermediate strainer 52 and low pressure inlet 44 . High pressure outlet 46 connects to a filter 58 and then to a pressure relief and bypass valve 60 . In one preferred embodiment, pressure relief and bypass valve 60 is a Model YUZ140 valve manufactured by General Pump.
A “T” 62 and a valve 64 , located intermediate valve 60 and filter 58 , connect the high pressure output 46 to a plurality of clean out nozzles 66 mounted in collection tank 14 to clean the tank's interior. A return line 68 connects a low pressure port 69 of valve 60 to water tank 12 . When a predetermined water pressure is exceeded in valve 60 , water is diverted through low port 69 and line 68 to tank 12 . A hose 70 , stored on a hose reel 73 ( FIG. 1 ), connects an output port 72 of valve 60 to a valve 74 on a digging tool 32 ( FIG. 3 ). A valve control 76 ( FIG. 3 ) at a handle 78 of digging tool 32 provides the operator with a means to selectively actuate valve 74 on digging tool 32 . The valve delivers a high pressure stream of water through a conduit 80 ( FIGS. 3 , 5 , 7 , and 10 ) attached to the exterior of an elongated pipe 82 that extends the length of digging tool 32 .
Referring to FIG. 3 , digging tool 32 includes handle 78 for an operator 34 ( FIG. 7 ) to grasp during use of the tool. A connector 84 , such as a “banjo” type connector, connects the vacuum system on drilling and back fill system 10 ( FIG. 1 ) to a central vacuum passage 86 ( FIG. 4 ) in digging tool 32 . Connector 84 is located proximate handle 78 . Vacuum passage 86 extends the length of elongated pipe 82 and opens to one end of a vacuum hose 88 . The other end of hose 88 connects to an inlet port 90 on collection tank 14 ( FIG. 7 ). It should be understood that other types of connectors may be used in place of “banjo” connector 84 , for example clamps, clips, or threaded ends on hose 88 and handle 78 .
Referring to FIGS. 4 and 5 , a fluid manifold 92 , located at a distal end 94 of digging tool 32 , connects to water conduit 80 and contains a plurality of nozzles that are angled with respect to one another. In one preferred embodiment having four nozzles, two nozzles 96 and 98 are directed radially inwardly at approximately 45 degrees from a vertical axis of the digging tool, and the two remaining nozzles 100 and 102 are directed parallel to the axis of the digging tool. During use of the drilling tool, nozzles 96 and 98 produce a spiral cutting action that breaks the soil up sufficiently to minimize clogging of large chunks of soil within vacuum passage 86 and/or vacuum hose 88 . Vertically downward pointing nozzles 100 and 102 enhance the cutting action of the drilling tool by allowing for soil to be removed not only above a buried utility, but in certain cases from around the entire periphery of the utility. In other words, the soil is removed above the utility, from around the sides of the utility, and from beneath the utility. This can be useful for further verifying the precise utility needing service and, if necessary, making repairs to or tying into the utility.
Digging tool 32 also contains a plurality of air inlets 104 formed in pipe distal end 94 that allow air to enter into vacuum passage 86 . The additional air, in combination with the angled placement of nozzles 96 and 98 , enhances the cutting and suction provided by tool 32 . Returning to FIG. 6 , digging tool 32 may also include a control 106 for controlling the tool's vacuum feature. Control 106 may be an electrical switch, a vacuum or pneumatic switch, a wireless switch, or any other suitable control to adjust the vacuum action by allowing the vacuum to be shut off or otherwise modulated. An antifreeze system, generally 190 ( FIGS. 1 and 2 ), may be provided to prevent freezing of the water pump and the water system. Thus, when the pump is to be left unused in cold weather, water pump 26 may draw antifreeze from the antifreeze reservoir through the components of the water system to prevent water in the hoses from freezing and damaging the system.
Turning now to FIGS. 7 and 10 , vacuum pump 28 is preferably a positive displacement type vacuum pump such as that used as a supercharger on diesel truck. In one preferred embodiment, vacuum pump 28 is a Model 4009-46R3 blower manufactured by Tuthill. A hose 112 connects an intake of the vacuum pump to a vacuum relief device 114 , which may be any suitable vacuum valve, such as a Model 215V-H01AQE spring loaded valve manufactured by Kunkle. Vacuum relief device 114 controls the maximum negative pressure of the vacuum pulled by pump 28 , which is in the range of between 10 and 15 inches of Hg in the illustrated embodiment. A filter 116 , located up stream of pressure relief valve 114 , filters the vacuum air stream before it passes through vacuum pump 28 . In one preferred embodiment, the filter media may be a paper filter such as those manufactured by Fleet Guard. Filter 116 connects to an exhaust outlet 118 of collection tank 14 by a hose 120 , as shown in FIGS. 1 , 7 , 8 , and 9 . An exhaust side 122 of vacuum pump 28 connects to a silencer 124 , such as a Model TS30TR silencer manufactured by Cowl. The output of silencer 124 exits into the atmosphere.
The vacuum air stream pulled through vacuum pump 28 produces a vacuum in collection tank 14 that draws a vacuum air stream through collection tank inlet 90 . When inlet 90 is not closed off by a plug 127 ( FIG. 1 ), the inlet may be connected to hose 88 leading to digging tool 32 . Thus, the vacuum air stream at inlet 90 is ultimately pulled through vacuum passage 86 at distal end 94 of tool 32 . Because it is undesirable to draw dirt or other particulate matter through the vacuum pump, a baffle system, for example as described in U.S. Pat. No. 6,470,605 (the entire disclosure which is incorporated herein), is provided within collection tank 14 to separate the slurry mixture from the vacuum air stream. Consequently, dirt, rocks, and other debris in the air flow hit a baffle (not shown) and fall to the bottom portion of the collection tank. The vacuum air stream, after contacting the baffle, continues upwardly and exits through outlet 118 through filter 116 and on to vacuum pump 28 .
Referring once again to FIG. 1 , collection tank 14 includes a discharge door 126 connected to the main tank body by a hinge 128 that allows the door to swing open, thereby providing access to the tank's interior for cleaning. A pair of hydraulic cylinders 130 (only one of which is shown in FIG. 8 ) are provided for tilting a forward end 132 of tank 14 upwards in order to cause the contents to run towards discharge door 126 . A gate valve 140 , coupled to a drain 142 in discharge door 126 , drains the liquid portion of the slurry in tank 14 without requiring the door to be opened. Gate valve 140 may also be used to introduce air into collection tank 14 to reduce the vacuum in the tank so that the door may be opened.
Running the length of the interior of collection tank 14 is a nozzle tube 132 ( FIG. 10 ) that includes nozzles 66 for directing high pressure water about the tank, and particularly towards the base of the tank. Nozzles 66 are actuated by opening valve 64 ( FIG. 10 ), which delivers high pressure water from pump 26 to nozzles 66 for producing a vigorous cleaning action in the tank. When nozzles 66 are not being used for cleaning, a small amount of water is allowed to continuously drip through the nozzles to pressurize them so as to prevent dirt and slurry from entering and clogging the nozzles.
Nozzle tube 132 , apart from being a conduit for delivering water, is also a structural member that includes a threaded male portion (not shown) on an end thereof adjacent discharge door 126 . When discharge door 126 is shut, a screw-down type handle 134 mounted in the door is turned causing a threaded female portion (not shown) on tube 132 to mate with the male portion. This configuration causes the door to be pulled tightly against an open rim (not shown) of the collection tank. Actuation of vacuum pump 28 further assists the sealing of the door against the tank opening. Discharge door 126 includes a sight glass 136 to allow the user to visually inspect the tank's interior.
Backfill reservoirs 20 and 22 are mounted on opposite sides of collection tank 14 . The back fill reservoirs are mirror images of each other; therefore, for purposes of the following discussion, reference will only be made to backfill reservoir 22 . It should be understood that backfill reservoir 20 operates identically to that of reservoir 22 . Consequently, similar components on backfill reservoir 20 are labeled with the same reference numerals as those on reservoir 22 .
Referring to FIG. 1 , back fill reservoir 22 is generally cylindrical in shape and has a bottom portion 144 , a top portion 146 , a back wall 148 , and a front wall 150 . Top portion 146 connects to bottom portion 144 by a hinge 152 . Hinge 152 allows backfill reservoir 22 to be opened and loaded with dirt by a front loader 154 , as shown in phantom in FIG. 1 . Top portion 146 secures to bottom portion 144 by a plurality of locking mechanisms 156 located on the front and back walls. Locking mechanisms 156 may be clasps, latches or other suitable devices that secure the top portion to the bottom portion. The seam between the top and bottom portion does not necessarily need to be a vacuum tight seal, but the seal should prevent backfill and large amounts of air from leaking from or into the reservoir. Front wall 150 has a hinged door 158 that is secured close by a latch 160 . As illustrated in FIG. 8 , hydraulic cylinders 130 enable the back fill reservoirs to tilt so that dirt can be off loaded through doors 158 .
As previously described above, backfill reservoirs 20 and 22 may be filled by opening top portions 146 of the reservoirs and depositing dirt into bottom portion 144 with a front loader. Vacuum pump 28 , however, may also load dirt into back fill reservoirs 20 and 22 . In particular, back fill reservoir 22 has an inlet port 162 and an outlet port 164 . During normal operation, plugs 166 and 168 fit on respective ports 162 and 164 to prevent backfill from leaking from the reservoir. However, these plugs may be removed, and outlet port 164 may be connected to inlet port 90 on collection tank 14 by a hose (not shown), while hose 88 may be attached to inlet port 162 . In this configuration, vacuum pump 28 pulls a vacuum air stream through collection tank 14 , as described above, through the hose connecting inlet port 90 to outlet port 164 , and through hose 88 connected to inlet port 162 . Thus, backfill dirt and rocks can be vacuumed into reservoirs 20 and 22 without the aide of loader 154 . It should be understood that this configuration is beneficial when backfill system 10 is being used in an area where no loader is available to fill the reservoirs. Once the reservoirs are filled, the hoses are removed from the ports, and plugs 166 and 168 are reinstalled on respective ports 162 and 164 .
Referring once more to FIG. 10 , hydraulic cylinders 130 , used to tilt collection tank 14 and backfill reservoirs 20 and 22 , are powered by electric hydraulic pump 30 . Hydraulic pump 30 connects to a hydraulic reservoir 170 and is driven by the electrical system of motor 16 . A high pressure output line 171 and a return line 173 connect pump 30 to hydraulic cylinders 130 . Hydraulic pump 172 , mounted on trailer 24 , is separately driven by motor 16 and includes its own hydraulic reservoir 174 . An output high pressure line 175 and a return line 186 connect pump 172 to a pair of quick disconnect couplings 182 and 184 , respectively. That is, high pressure line 175 connects to quick disconnect coupling 182 ( FIGS. 1 and 2 ) through a control valve 178 , and return line 186 connects quick disconnect coupling 184 to reservoir 188 . A pressure relief valve 176 connects high pressure line 175 to reservoir 188 and allows fluid to bleed off of the high pressure line if the pressure exceeds a predetermined level. A pressure gauge 180 may also be located between pump 172 and control valve 178 .
Quick disconnect coupling 182 provides a high pressure source of hydraulic fluid for powering auxiliary tools, such as drilling apparatus 18 , tamper device 185 , or other devices that may be used in connection with drilling and backfill system 10 . The high pressure line preferably delivers between 5.8 and 6 gallons per minute of hydraulic fluid at a pressure of 2000 lbs/in 2 . Hydraulic return line 186 connects to a quick disconnect coupling 184 ( FIGS. 1 and 2 ) on trailer 24 . Intermediate quick disconnect coupling 184 and hydraulic fluid reservoir 174 is a filter 188 that filters the hydraulic fluid before returning it to hydraulic reservoir 174 . While quick disconnect couplings 182 and 184 are shown on the side of trailer 24 , it should be understood that the couplings may also be mounted on the rear of trailer 24 .
Referring to FIGS. 1 and 2 , drilling apparatus 18 is carried on trailer 24 and is positioned using winch and crane 36 . Drilling apparatus 18 includes a base 192 , a vertical body 194 , and a hydraulic drill motor 196 slidably coupled to vertical body 194 by a bracket 198 . A high pressure hose 200 and a return hose 202 power motor 196 . A saw blade 204 attaches to an output shaft of hydraulic motor 196 and is used to drill a coupon 206 ( FIG. 7 ) in pavement, concrete or other hard surfaces to expose the ground above the buried utility. The term coupon as used herein refers to a shaped material cut from a continuous surface to expose the ground beneath the material. For example, as illustrated in FIG. 7 , coupon 206 is a circular piece of concrete that is cut out of a sidewalk to expose the ground thereunder.
Body 194 has a handle 220 for the user to grab and hold onto during the drilling process. Hydraulic fluid hoses 200 and 202 connect to two connectors 222 and 224 ( FIG. 10 ) mounted on body 194 and provide hydraulic fluid to hydraulic drill motor 196 . A crank 226 is used to move the drill motor vertically along body 194 . Drilling apparatus 18 is a Model CD616 Hydra Core Drill manufactured by Reimann & Georger of Buffalo, N.Y. and is referred to herein as a “core drill.”
In prior art systems, base 192 was secured to pavement or concrete using lag bolts, screws, spikes, etc. These attachment methods caused unnecessary damage to the surrounding area and required additional repair after the utility was fixed and the hole was backfilled. Additionally, having to drill additional holes for the bolts or screws or pounding of the spikes with a sledge hammer presented unnecessary additional work. Thus, the drilling apparatus of the present invention uses the vacuum system of drilling and backfill system 10 to secure base 192 to the pavement.
Referring to FIGS. 6 and 6A , base 192 includes a flat plate 195 having a connector 206 attached to a top surface thereof. Connector 206 attaches to an outlet port 208 formed in a top surface of plate 195 that is in fluid communication with a recessed chamber 210 ( FIG. 6A ) formed in a bottom surface 212 of plate 195 . That is, outlet port 208 has a passageway therethrough that extends between the top and bottom surfaces. A groove 230 formed in bottom surface 212 receives a pliable gasket 232 that forms a relatively air tight seal between the bottom surface 212 and the pavement or concrete being drilled. It should be understood that while a gasket is shown, it may not be necessary depending on the strength of the vacuum air stream being pulled through connector 206 since bottom surface 212 can form a sufficient seal with the pavement or concrete. A bracket 214 coupled to a top surface of plate 195 fixedly secures body 194 ( FIG. 2 ) to base 192 . A bolt or screw 216 is received through body 194 and into a threaded bore 218 to secure the body to the base. Wheels attached to the base allow the drilling apparatus to be moved around the work area after it has been off loaded the trailer by winch and crane 36 . The term “base” as used herein refers to a drill support structure that maintains a secure connection of the drill to a surface proximate the area to be drilled. The drill base should have a generally planar bottom surface, and the remaining structure of the base may be of any suitable shape to secure the drill motor to the base.
Referring to FIG. 2 , hose 88 connects to connector 206 by a suitable clamp (not shown). Once core drill 18 is positioned, vacuum pump 26 is turned on and a vacuum is pulled through hose 88 into chamber 210 , providing a vacuum of between 12-15 inches of Hg, which is sufficient to fixedly secure base 192 to the pavement or concrete during the drilling process. Prior to moving core drill 18 , vacuum pump 28 is shut down to eliminate the vacuum produced in chamber 210 .
The operation of the drilling and backfill system will now be described with reference to FIGS. 2 , 7 to 9 and 10 . Prior to using drilling and backfill system 10 , water is added to water tank 12 , and valve 54 is opened to allow water to flow to water pump 26 . Motor 16 is powered up, and water pressure is allowed to build in the system.
Referring to FIG. 2 , if a utility is located under concrete, core drill 18 is positioned over the utility, and vacuum hose 88 is connected from inlet port 90 on collection tank 14 to connector 206 on base plate 195 . Hydraulic hoses 200 and 202 are connected to hydraulic motor 196 at connectors 222 and 224 , and vacuum pump 28 and hydraulic pump 172 are powered up. Saw 204 is used to cut coupon 206 ( FIG. 7 ) from the concrete to expose the ground over the utility. Hose 70 connects to saw 204 and provides a steady stream of water that flushes the drill bit during the drilling process. Coupon 206 is removed from the hole and placed aside so that it can be reused in repairing the hole after it is backfilled.
Next, and referring to FIG. 7 , the user disconnects vacuum hose 88 from connector 206 and connects the hose to digging tool handle 78 using banjo connector 84 . High pressure water hose 70 is also connected to valve 74 to provide water to the digging tool. As tool 32 is used, it is pressed downwardly into the ground to dig a hole. For larger diameter holes, digging tool 32 is moved in a generally circular manner as it is pressed downward. Slurry formed in the hole is vacuumed by tool 32 through vacuum passage 86 ( FIGS. 4 and 5 ) and accumulates in collection tank 26 . Once the hole is completed and the utility exposed, the vacuum system can be shut down, and the operators may examine or repair the utility as needed.
After work on the utility is completed, and referring to FIG. 8 , the operator may cover the utility with clean backfill from backfill reservoirs 20 and 22 . In particular, trailer 24 is positioned so that one of backfill reservoirs 20 or 22 is proximate the hole. Hydraulic cylinders 130 are activated, causing the tanks to tip rearward so that backfill can be delivered through door 158 into the hole. Once the hole is sufficiently filled, hydraulic cylinders 130 return reservoirs 20 and 22 to their horizontal position, and door 158 is secured in the closed position.
With reference to FIG. 9 , operator 34 may use a tamping device 185 to tamp the backfill in the hole. Tamping device 185 connects to hydraulic pump 172 through quick disconnect couplings 182 and 184 via hydraulic lines 200 and 202 . Tamping device 185 is used to pack the backfill in the hole and to remove any air pockets. Once the hole has been filed and properly packed, coupon 206 is moved into the remaining portion of the hole. The reuse of coupon 206 eliminates the need to cover the hole with new concrete. Instead, coupon 206 is placed in the hole, and grout is used to seal any cracks between the key and the surrounding concrete. Thus, the overall cost and time of repairing the concrete is significantly reduced, and the need for new concrete is effectively eliminated.
Drilling and backfill system 10 can be used to dig multiple holes before having to empty collection tank 14 . However, once collection tank 14 is full, it can be emptied at an appropriate dump site. In emptying collection tank 14 , motor 16 is idled to maintain a vacuum in tank 14 . This allows the door handle to be turned so that the female threaded member (not shown) is no longer in threading engagement with the male member (not shown) on nozzle rod 132 , while the vacuum pressure continuing to hold the door closed. Once motor 16 is shut down, the vacuum pressure is released so that air enters the tank, thereby pressurizing the tank and allowing the door to be opened. Once opened, hydraulic cylinders 130 can be activated to raise forward end 132 upward dumping the slurry from the tank.
Collection tank 14 may also include a vacuum switch and relay (not shown) that prevents the tank from being raised for dumping until the vacuum in the tank has dropped below a predetermined level for door 126 to be opened. Once the vacuum in the tank has diminished to below the predetermined level, tank 14 may be elevated for dumping. This prevents slurry from being pushed up into filter 116 if door 126 can not open.
It should be appreciated by those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope and spirit of the invention. It is intended that the present invention cover such modifications and variations as come within the scope and spirit of the appended claims and their equivalents. | A mobile digging and backfill system for removing and collecting material above a buried utility. The system comprises a mobile chassis, a collection tank mounted to the chassis, a water pump mounted to the chassis for delivering a pressurized liquid flow against the material for loosening the material at a location, a vacuum pump connected to the collection tank so that an air stream created by the vacuum pump draws the material and the fluid from the location into the collection tank, and at least one backfill reservoir mounted to the chassis for carrying backfill for placement at the location. | 4 |
BRIEF SUMMARY OF THE INVENTION
This invention relates to papermaking fabrics and has to do more particularly with needled fabrics having enhanced dimensional stability.
The dimensional stability of papermaking fabrics has been a long-standing problem in the industry. While high strength and low elongation have heretofore been used to enhance dimensional stability of the fabrics, such fibers often inhibit or otherwise interfere with the surface characteristics to be imparted to the fabrics, and consequently their use has been a compromise between achieving the desired stability while maintaining the required surface characteristics.
The present invention contemplates the provision of a base fabric which is utilized in conjunction with a needled batt to provide a paper machine felt, the needled fabric being subjected to a fusing operation which stabilizes the fabric and enhances the adhesion of the batt fibers to the base fabric as well as enhancing resistance of the fabric to compaction.
The base fabric is composed of core-wrapped yarns, i.e., a core forming yarn wrapped with one or more layers of wrapping yarn. Essentially the core forming yarns will be heat infusible and the wrap forming yarns heat fusible, the yarns being utilized to produce woven or wrap knitted fabrics. A fibrous batt, which may comprise fusible or infusible fibers, or blends of different types, is needled to one surface of the base fabric, whereupon the fabric is subjected to a heat source so that the fusible wrap yarns on the surface of the fabric opposite the batt will melt and bond at each contact point of the machine direction and cross-machine direction yarns. As a result of the crossover melting and bonding of the wrap yarns, the fused yarn surface becomes smooth and the fabric becomes dimensionally stable in all directions and will resist stretching, wrinkling, distortion or bowing, and the needled batt will be firmly anchored to the base fabric.
The fusible yarns of the base fabric, which may be either staple yarns or multifilaments, will be inherently thermoplastic and will become tacky upon exposure to a temperature close to their melting points and will solidify and become non-tacky upon cooling. The infusible yarns or fibers comprise those which do not melt or become tacky upon heating to a temperature at which the fusible yarns will become tacky. While the temperatures will vary depending upon the particular yarns employed, it will be understood that the term infusible yarns denotes those yarns which are unaffected by heat at temperatures which will result in the fusion of the fusible yarns.
In forming the core wrapped yarns, for which purpose conventional covering or twisting machines may be employed, it is also possible to use two or more types of core yarns selected from both the fusible and infusible classes depending upon the end use property requirements, but in any event at least one component of the core yarn must be of the infusible type. The core may have a single wrap or a plurality of wraps, but the outermost or top wrap must be fusible and the degree of wrap should be such that the entire surface of the core yarn will be substantially covered by the wrap yarn. It is also preferred to use high strength and low shrinkage core yarns in the machine direction, and relatively low shrinkage core yarns in the cross-machine direction to reduce excessive shrinkage and tension during the surface fusing.
The fusing of the base fabric is accomplished by subjecting the exposed surface to a temperature level high enough to melt and fuse at least the top wrap yarns, thus producing a surface-to-surface bond at each crossover point. It has been found that when the fabric is exposed to fusing temperature, preferential surface characteristics are achieved, i.e., the fused surface becomes smooth and incompressible while the unfused surface retains the yarn integrity and is relatively soft and compressible. Fusion can be accomplished by passing the fabric over a suitable heating source, such as an infra red heater, a radient heater, or an open flame, the fusion time being controlled by the speed at which the fabric is advanced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view illustrative of a plain weave base fabric in accordance with the invention.
FIG. 2 is a sectional view taken along the line 2--2 of FIG. 1.
FIG. 3 is a sectional view similar to FIG. 2 illustrating the application of batt fibers to one surface of the base fabric.
FIG. 4 is a diagrammatic elevational view illustrating heating means for fusing the wrap yarns at their crossover points.
DETAILED DESCRIPTION
A base fabric in accordance with the invention may comprise a woven or wrap knitted fabric, the fabric illustrated in FIG. 1 comprising a plain weave fabric having cross-machine direction yarns 1 and machine direction yarns 2. The yarns 1 and 2 are core wrapped yarns each having a core 3 and an outer wrap 4. The term yarn as used herein contemplates spun yarns and filaments, which may be either monofilament or multifilament.
Basically, two types of yarns are utilized, the first comprising infusible yarns which do not easily melt or become tacky upon heating to relative high temperatures such as approximately 260° C. Examples of yarns of this type are aramid fibers, sold under the trademarks Kevlar and Nomex, homopolymer acrylics, coated Fiberglass, metallic fibers, and Novoloid fibers. The fusible type yarns may comprise polyamide, polyester, olefin, and polyvinyl chloride, which will become fusible at temperatures below those of the infusible yarns.
The core yarns may comprise single or multiple ends of infusible type or combinations of fusible and infusible types, although the major content of the core yarn preferably will be of the infusible type. It may be observed, however, that core yarns consisting wholly of yarns characterized as being of the fusible type also may be employed provided the load bearing machine direction core yarns have a significantly higher melting temperature than the melting temperature of the wrap yarns and the core yarns are not significantly degraded after fusing the warp yarns. For example, a core of polyester or Nylon yarns can be successfully wrpped with polyethelene or polypropylene wrap yarns. It is also preferred to use high strength and low shrinkage core yarns in the machine direction and low shrinkage core yarns in the cross-machine direction to reduce excessive shrinkage and tension during fusion.
The core yarns may have a single wrap or a double wrap of wrapped yarns. If a single wrap is selected, the wrap yarns must be of the fusible type. On the other hand, if the core yarn is double wrapped, then the inner or first wrap may be either fusible or infusible or combination of both types, but the second or outer wrap must be of the fusible type. Preferably, if the core yarn is double wrapped, the inner or first wrap will be in one direction and the second or outer wrap will be in the opposite direction. It is also preferred to use multifilament wrap yarns as the outermost yarns because they achieve a smooth yarn surface after fusion.
Following formation of the base fabric, a fiber batt, indicated at 8 in FIG. 3, is needled onto one surface of the base fabric by a conventional needle punching operation. The batt fibers may be fusible, infusible, or blends of different fibers, depending upon the type of outer wrap yarns used in the base fabric. For example, if the base fabric yarns are wrapped with multifilament polypropylene yarns, the batt fibers may comprise Nylon or polyester which will not be adversely affected when the polypropylene wrapped yarns are fused.
Fusing of the fabric is accomplished by subjecting the surface opposite the batt fiber surface to a temperature sufficiently high to melt and fuse at least the outermost wrap yarns, thereby producing a surface-to-surface bond at each crossover point of the machine direction and cross-machine direction yarns. Where this is done preferential surface characteristics will be achieved in that the fused surface becomes smooth and incompressible while the unfused surface retains the integrity of the wrap yarns and is relatively soft and compressible. At the same time, the needled batt fibers are securely anchored to the base fabric. Press felts fabricated in this manner have excellent dimensional stability, improved batt fiber adhesion to base fabric, improved drainage, less tendency to plug, easy cleanability, and improved resistance to compaction.
As diagrammatically illustrated in FIG. 4, a fabric 5 formed in accordance with the invention may be advanced in a path of travel over a suitable heat source 6, such as an infra red heater, a radiant heater, or an open flame. Fusing time may be readily controlled by controlling the speed of travel of the fabric. The fabric tension also may be controlled; and time, temperature and tension levels may be varied depending upon the type of wrap yarns which are used. However, the balance of time and temperature should be such that the wrap yarns will melt without excessive flow or degradation of the core yarns due to oxidation. In this connection, where the heat source comprises an infra red heater, an inert gas atmosphere may be utilized to reduce ocidative degradation of the wrap yarns.
Exemplary embodiments of fabrics in accordance with the invention are as follow:
EXAMPLE I
A base fabric having thirty-two ends per inch in the machine direction and twenty-eight picks in the cross-machine direction was woven on a conventional loom using core wrap yarns in a duplex weave pattern. The core wrap yarns in both machine and cross-machine directions were prepared using the following components:
Core: 400 Denier/267 Filaments, Kevlar Aramid Yarn, Type T-964 with O twist.
Outer Wrap Yarn: DuPont Nylon 840 Denier/140 Filament, Type 715.
Inner Wrap Yarn: Allied PET Base Polyester 1000 Denier/192 Filaments, Type 1W72.
The core wrap yarns were prepared on a conventional elastic covering machine in which the innermost wrap was in the "Z" direction and the outer yarn wrap in the "S" direction.
The woven fabric was formed into an endless belt, a fibrous batt of Nomex Aramid fibers of 3" stapel, 5.5 denier was needled to its uppermost surface. Following needling the fabric was mounted between two rotating rolls with a tension of ten pounds per lineal inch applied to the belt. The undersurface of the fabric was fused using an IR heater at a temperature of about 260° C. while maintaining tension, with exposure time controlled by the belt speed. After cooling, the fused fabric surface was smooth and each crossover point was found to be firmly bonded together, resulting in excellent dimensional stability while the unfused needled surface of the fabric retained its fibrous structure and was compressible.
EXAMPLE II
In another embodiment, a core wrap yarn was prepared using the following components:
Core: Three ends of DuPont Nylon 840 Denier/140 Filaments, Type 715.
Inner and Outer Wraps: Two ends of 420 Denier/35 Filament, Twist 0.52, Herculon Olefin Yarn, Type 309. Inner Wrap in "Z" direction and Outer Wrap in "S" direction.
Using the above core wrap yarn in both warp and filling directions, a woven structure was formed into an endless belt; a fibrous batt comprising 50% by weight of 6.0 Denier, 2.5" polypropylene staple and 50% Nylon 6,6 of 6 Denier, 3" staple was needled onto its uppermost surface. The endless belt, mounted between two rotating rolls with a tension of 5 pounds per lineal inch applied to it was subjected to 340° F. temperature. The undersurface of the fabric was fused while maintaining tension, with exposure time controlled by the felt speed.
After cooling, the fused fabric surface was found smooth, batt layer anchored firmly to the base fabric with each crossover point bonded together resulting in excellent dimentional stability.
EXAMPLE III
In another embodiment, a core wrap yarn was prepared using the following components:
Core:
(a) Three Ends of 840 Denier/140 Filament, Nylon 6,6.
(b) Three Ends of 350 Denier/34 Filaments low temperature meltable Nylon Type Grilon K115 (Emser Industries).
Inner and Outer Wrap Yarn: Two Ends of 350 Denier/34 Filaments Grilon K115 Type Nylon. Wrapped in opposite direction using conventional elastic covering machine.
A base fabric structure was woven using the above yarn in both wrap and filling direction. A fibrous batt consisting of blend of Grilon K115, 6 Denier, 2.5" staple fiber and 6 Denier, 3" staple of Nylon 6,6 Type 39N was needled onto both sides of the woven base fabric. A small sample of this structure was subjected to hot air at about 275° F. for several minutes.
After cooling, the batt was found to be firmly anchored to base fabric, the fabric was dimensionally stable with crossover points bonded together. | A papermaking fabric composed of a base having a fibrous batt needled to one surface thereof, the base being formed of interwoven core wrapped yarns, comprising core yarns which are effectively heat infusible and wrapping yarns which are effectively heat fusible, the fibrous batt being either heat fusible or heat infusible, the wrapping yarns of the interwoven base being heat fused to each other at their points of contact with each other on the side of the interwoven base opposite the fibrous batt. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of Ser. No. 10/408,328, filed Apr. 7, 2003, now issued as U.S. Pat. No. 6,808,536, which in turn is a continuation of application Ser. No. 09/874,117, filed Jun. 4, 2001, now issued as U.S. Pat. No. 6,585,764, which is a continuation of application Ser. No. 09/061,568, filed Apr. 16, 1998, now issued as U.S. Pat. No. 6,273,913, which in turn claims benefit of provisional application Ser. No. 60/044,692, filed Apr. 18, 1997.
FIELD OF THE INVENTION
Delivery of rapamycin locally, particularly from an intravascular stent, directly from micropores in the stent body or mixed or bound to a polymer coating applied on stent, to inhibit neointimal tissue proliferation and thereby prevent restenosis. This invention also facilitates the performance of the stent in inhibiting restenosis.
BACKGROUND OF THE INVENTION
Re-narrowing (restenosis) of an artherosclerotic coronary artery after percutaneous transluminal coronary angioplasty (PTCA) occurs in 10–50% of patients undergoing this procedure and subsequently requires either further angioplasty or coronary artery bypass graft. While the exact hormonal and cellular processes promoting restenosis are still being determined, our present understanding is that the process of PTCA, besides opening the artherosclerotically obstructed artery, also injures resident coronary arterial smooth muscle cells (SMC). In response to this injury, adhering platelets, infiltrating macrophages, leukocytes, or the smooth muscle cells (SMC) themselves release cell derived growth factors with subsequent proliferation and migration of medial SMC through the internal elastic lamina to the area of the vessel intima. Further proliferation and hyperplasia of intimal SMC and, most significantly, production of large amounts of extracellular matrix over a period of 3–6 months results in the filling in and narrowing of the vascular space sufficient to significantly obstruct coronary blood flow.
Several recent experimental approaches to preventing SMC proliferation have shown promise althrough the mechanisms for most agents employed are still unclear. Heparin is the best known and characterized agent causing inhibition of SMC proliferation both in vitro and in animal models of balloon angioplasty-mediated injury. The mechanism of SMC inhibition with heparin is still not known but may be due to any or all of the following: 1) reduced expression of the growth regulatory protooncogenes c-fos and c-myc, 2) reduced cellular production of tissue plasminogen activator; are 3) binding and dequestration of growth regulatory factors such as fibrovalent growth factor (FGF).
Other agents which have demonstrated the ability to reduce myointimal thickening in animal models of balloon vascular injury are angiopeptin (a somatostatin analog), calcium channel blockers, angiotensin converting enzyme inhibitors (captopril, cilazapril), cyclosporin A, trapidil (an antianginal, antiplatelet agent), terbinafine (antifungal), colchicine and taxol (antitubulin antiproliferatives), and c-myc and c-myb antinsense oligonucleotides.
Additionally, a goat antibody to the SMC mitogen platelet derived growth factor (PDGF) has been shown to be effective in reducing myointimal thickening in a rat model of balloon angioplasty injury, thereby implicating PDGF directly in the etiology of restenosis. Thus, while no therapy has as yet proven successful clinically in preventing restenosis after angioplasty, the in vivo experimental success of several agents known to inhibit SMC growth suggests that these agents as a class have the capacity to prevent clinical restenosis and deserve careful evaluation in humans.
Coronary heart disease is the major cause of death in men over the age of 40 and in women over the age of fifty in the western world. Most coronary artery-related deaths are due to atherosclerosis. Atherosclerotic lesions which limit or obstruct coronary blood flow are the major cause of ischemic heart disease related mortality and result in 500,000–600,000 deaths in the United States annually. To arrest the disease process and prevent the more advanced disease states in which the cardiac muscle itself is compromised, direct intervention has been employed via percutaneous transiuminal coronary angioplasty (PTCA) or coronary artery bypass graft (CABG)
PTCA is a procedure in which a small balloon-tipped catheter is passed down a narrowed coronary artery and then expanded to re-open the artery. It is currently performed in approximately 250,000–300,000 patients each year. The major advantage of this therapy is that patients in which the procedure is successful need not undergo the more invasive surgical procedure of coronary artery bypass graft. A major difficulty with PTCA is the problem of post-angioplasty closure of the vessel, both immediately after PTCA (acute reocclusion) and in the long term (restenosis).
The mechanism of acute reocclusion appears to involve several factors and may result from vascular recoil with resultant closure of the artery and/or deposition of blood platelets along the damaged length of the newly opened blood vessel followed by formation of a fibrin/red blood cell thrombus. Recently, intravascular stents have been examined as a means of preventing acute reclosure after PTCA.
Restenosis (chronic reclosure) after angioplasty is a more gradual process than acute reocclusion: 30% of patients with subtotal lesions and 50% of patients with chronic total lesions will go on to restenosis after angioplasty. While the exact mechanism for restenosis is still under active investigation, the general aspects of the restenosis process have been identified.
In the normal arterial will, smooth muscle cells (SMC) proliferate at a low rate (<0.1%/day; ref). SMC in vessel wall exists in a ‘contractile’ phenotype characterized by 80–90% of the cell cytoplasmic volume occupied with the contractile apparatus. Endoplasmic reticulum, golgi bodies, and free ribosomes are few and located in the perinuclear region. Extracellular matrix surrounds SMC and is rich in heparin-like glycosylaminoglycans which are believed to be responsible for maintaining SMC in the contractile phenotypic state.
Upon pressure expansion of an intracoronary balloon catheter during angioplasty, smooth muscle cells within the arterial wall become injured. Cell derived growth factors such as platelet derived growth factor (PDGF), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), etc. released from platelets (i.e., PDGF) adhering to the damaged arterial luminal surface, invading macrophages and/or leukocytes, or directly from SMC (i.e., BFGF) provoke a proliferation and migratory response in medial SMC. These cells undergo a phenotypic change from the contractile phenotyope to a ‘synthetic’ phenotype characterized by only few contractile filament bundles but extensive rough endoplasmic reticulum, golgi and free ribosomes. Proliferation/migration usually begins within 1–2 days post-injury and peaks at 2 days in the media, rapidly declining thereafter (Campbell et al., In: Vascular Smooth Muscle Cells in Culture, Campbell, J. H. and Campbell, G. R., Eds, CRC Press, Boca Ration, 1987, pp. 39–55); Clowes, A. W. and Schwartz, S. M., Circ. Res. 56:139–145, 1985).
Finally, daughter synthetic cells migrate to the intimal layer of arterial smooth muscle and continue to proliferate. Proliferation and migration continues until the damaged luminal endothelial layer regenerates at which time proliferation ceases within the intima, usually within 7–14 days postinjury. The remaining increase in intimal thickening which occurs over the next 3–6 months is due to an increase in extracellular matrix rather than cell number. Thus, SMC migration and proliferation is an acute response to vessel injury while intimal hyperplasia is a more chronic response. (Liu et al., Circulation, 79:1374–1387, 1989).
Patients with symptomatic reocclusion require either repeat PTCA or CABG. Because 30–50% of patients undergoing PTCA will experience restenosis, restenosis has clearly limited the success of PTCA as a therapeutic approach to coronary artery disease. Because SMC proliferation and migration are intimately involved with the pathophysiological response to arterial injury, prevention of SMC proliferation and migration represents a target for pharmacological intervention in the prevention of restenosis.
SUMMARY OF THE INVENTION
Novel Features and Applications to Stent Technology
Currently, attempts to improve the clinical performance of stents have involved some variation of either applying a coating to the metal, attaching a covering or membrane, or embedding material on the surface via ion bombardment. A stent designed to include reservoirs is a new approach which offers several important advantages over existing technologies.
Local Drua Delivery from a Stent to Inhibit Restenosis
In this application, it is desired to deliver a therapeutic agent to the site of arterial injury. The conventional approach has been to incorporate the therapeutic agent into a polymer material which is then coated on the stent. The ideal coating material must be able to adhere strongly to the metal stent both before and after expansion, be capable of retaining the drug at a sufficient load level to obtain the required dose, be able to release the drug in a controlled way over a period of several weeks, and be as thin as possible so as to minimize the increase in profile. In addition, the coating material should not contribute to any adverse response by the body (i.e., should be non-thrombogenic, non-inflammatory, etc.). To date, the ideal coating material has not been developed for this application.
An alternative would be to design the stent to contain reservoirs which could be loaded with the drug. A coating or membrane of biocompatable material could be applied over the reservoirs which would control the diffusion of the drug from the reservoirs to the artery wall.
One advantage of this system is that the properties of the coating can be optimized for achieving superior biocompatibility and adhesion properties, without the addition requirement of being able to load and release the drug. The size, shape, position, and number of reservoirs can be used to control the amount of drug, and therefore the dose delivered.
DESCRIPTION OF THE DRAWINGS
The invention will be better understood in connection with the following figures in which FIGS. 1 and 1A are top views and section views of a stent containing reservoirs as described in the present invention;
FIGS. 2 a and 2 b are similar views of an alternate embodiment of the stent with open ends;
FIGS. 3 a and 3 b are further alternate figures of a device containing a grooved reservoir; and
FIG. 4 is a layout view of a device containing a reservoir as in FIG. 3 .
DETAILED DESCRIPTION OF THE INVENTION
Pharmacological attempts to prevent restenosis by pharmacologic means have thus far been unsuccessful and all involve systemic administration of the trial agents. Neither aspirin-dipyridamole, ticlopidine, acute heparin administration, chronic warfarin (6 months) nor methylprednisolone have been effective in preventing restenosis although platelet inhibitors have been effective in preventing acute reocclusion after angioplasty. The calcium antagonists have also been unsuccessful in preventing restenosis, although they are still under study. Other agents currently under study include thromboxane inhibitors, prostacyclin mimetics, platelet membrane receptor blockers, thrombin inhibitors and angiotensin converting enzyme inhibitors. These agents must be given systemically, however, and attainment of a therapeutically effective dose may not be possible; antiproliferative (or anti-restenosis) concentrations may exceed the known toxic concentrations of these agents so that levels sufficient to produce smooth muscle inhibition may not be reached (Lang et al., 42 Ann. Rev. Med., 127–132 (1991); Popma et al., 84 Circulation, 1426–1436 (1991)).
Additional clinical trials in which the effectiveness for preventing restenosis of dietary fish oil supplements, thromboxane receptor antagonists, cholesterol lowering agents, and serotonin antagonists has been examined have shown either conflicting or negative results so that no pharmacological agents are as yet clinically available to prevent post-angioplasty restenosis (Franklin, S. M. and Faxon, D. P., 4 Coronary Artery Disease, 232–242 (1993); Serruys, P. W. et al., 88 Circulation, (part 1) 1588–1601, (1993).
Conversely, stents have proven useful in preventing reducing the proliferation of restenosis. Stents, such as the stent 10 seen in layout in FIG. 4 , balloon-expandable slotted metal tubes (usually but not limited to stainless steel), which when expanded within the lumen of an angioplastied coronary artery, provide structural support to the arterial wall. This support is helpful in maintaining an open path for blood flow. In two randomized clinical trials, stents were shown to increase angiographic success after PTCA, increase the stenosed blood vessel lumen and to reduce the lesion recurrence at 6 months (Serruys et al., 331 New Eng Jour. Med, 495, (1994); Fischman et al., 331 New Eng Jour. Med, 496–501 (1994). Additionally, in a preliminary trial, heparin coated stents appear to possess the same benefit of reduction in stenosis diameter at follow-up as was observed with non-heparin coated stents. Additionally, heparin coating appears to have the added benefit of producing a reduction in sub-acute thrombosis after stent implantation (Serruys et al., 93 Circulation, 412–422, (1996). Thus, 1) sustained mechanical expansion of a stenosed coronary artery has been shown to provide some measure of restenosis prevention, and 2) coating of stents with heparin has demonstrated both the feasibility and the clinical usefulness of delivering drugs to local, injured tissue off the surface of the stent.
Numerous agents are being actively studied as antiproliferative agents for use in restenosis and have shown some activity in experimental animal models. These include: heparin and heparin fragments (Clowes and Karnovsky, 265 Nature, 25–626, (1977); Guyton, J. R. et al. 46 Circ. Res., 625–634, (1980); Clowes, A. W. and Clowes, M. M., 52 Lab. Invest., 611–616, (1985); Clowes, A. W. and Clowes, M. M., 58 Circ. Res., 839–845 (1986);. Majesky et al., 61 Circ Res., 296–300, (1987); Snow et al., 137 Am. J. Pathol., 313–330 (1990); Okada, T. et al., 25 Neurosurgery, 92–898, (1989) colchicine (Currier, J. W. et al., 80 Circulation, 11–66, (1989), taxol (ref), agiotensin converting enzyme (ACE) inhibitors (Powell, J. S. et al., 245 Science, 186–188 (1989), angiopeptin (Lundergan, C. F. et al., 17 Am. J. Cardiol. (Suppi. B); 132B–136B (1991), Cyclosporin A (Jonasson, L. et. al., 85 Proc. Natl. Acad. Sci., 2303 (1988), goat-anti-rabbit PDGF antibody (Ferns, G. A. A., et al., 253 Science, 1129–1132 (1991), terbinafine (Nemecek, G. M. et al., 248 J. Pharmacol. Exp. Thera., 1167–11747 (1989), trapidil (Liu, M. W. et al., 81 Circulation, 1089–1093 (1990), interferon-gamma (Hansson, G. K. and Holm, 84 J. Circulation, 1266–1272 (1991), steroids (Colburn, M. D. et al., 15 J. Vasc. Surg., 510–518 (1992), see also Berk, B. C. et al., 17 J. Am. Coll. Cardiol., 111B–117B (1991), ionizing radiation (ref), fusion toxins (ref) antisense oligonucleotides (ref), gene vectors (ref), and rapamycin (see below).
Of particular interest in rapamycin. Rapamycin is a macrolide antibiotic which blocks IL-2-mediated T-cell proliferation and possesses antiinflammatory activity. While the precise mechanism of rapamycin is still under active investigation, rapamycin has been shown to prevent the G 1 to S phase progression of T-cells through the cell cycle by inhibiting specific cell cyclins and cyclin-dependent protein kinases (Siekierka, Immunol. Res. 13: 110–116, 1994). The antiproliferative action of rapamycin is not limited to T-cells; Marx et al. (Circ Res 76:412–417, 1995) have demonstrated that rapamycin prevents proliferation of both rat and human SMC in vitro while Poon et al. have shown the rat, porcine, and human SMC migratin can also be inhibited by rapamycin (J Clin Invest 98: 2277–2283, 1996). Thus, rapamycin is capable of inhibiting both the inflammatory response known to occur after arterial injury and stent implantation, as well as the SMC hyperproliferative response. In fact, the combined effects of rapamycin have been demonstrated to result in a diminished SMC hyperproliferative response in a rat femoral artery graft model and in both rat and porcine arterial balloon injury models (Gregory et al., Transplantation 55:1409–1418, 1993; Gallo et al., in press, (1997)). These observations clearly support the potential use of rapamycin in the clinical setting of post-angioplasty restenosis.
Although the ideal agent for restenosis has not yet been identified, some desired properties are clear: inhibition of local thrombosis without the risk systemic bleeding complications and continuous and prevention of the dequale of arterial injury, including local inflammation and sustained prevention smooth muscle proliferation at the site of angioplasty without serious systemic complications. Inasmuch as stents prevent at least a portion of the restenosis process, an agent which prevents inflammation and the proliferation of SMC combined with a stent may provide the most efficacious treatment for post-angioplasty restenosis.
Experiments
Agents: Rapamycin (sirolimus) structural analogs (macrocyclic lactones) and inhibitors of cell-cycle progression.
Delivery Methods:
These can vary:
Local delivery of such agents (rapamycin) from the struts of a stent, from a stent graft, grafts, stent cover or sheath. Involving comixture with polymers (both degradable and nondegrading) to hold the drug to the stent or graft. or entrapping the drug into the metal of the stent or graft body which has been modified to contain micropores or channels, as will be explained further herein. or including covalent binding of the drug to the stent via solution chemistry techniques (such as via the Carmeda process) or dry chemistry techniques (e.g. vapour deposition methods such as rf-plasma polymerization) and combinations thereof. Catheter delivery intravascularly from a tandem balloon or a porous balloon for intramural uptake Extravascular delivery by the pericardial route Extravascular delivery by the advential application of sustained release formulations.
Uses: for inhibition of cell proliferation to prevent neointimal proliferation and restenosis.
prevention of tumor expansion from stents prevent ingrowth of tissue into catheters and shunts inducing their failure.
1. Experimental Stent Delivery Method—Delivery from Polymer Matrix:
Solution of Rapamycin, prepared in a solvent miscible with polymer carrier solution, is mixed with solution of polymer at final concentration range 0.001 weight % to 30 weight % of drug. Polymers are biocompatible (i.e., not elicit any negative tissue reaction or promote mural thrombus formation) and degradable, such as lactone-based polyesters or copolyesters, e.g., polylactide, polycaprolacton-glycolide, polyorthoesters, polyanhydrides; poly-amino acids; polysaccharides; polyphosphazenes; poly(ether-ester) copolymers, e.g., PEO-PLLA, or blends thereof. Nonabsorbable biocompatible polymers are also suitable candidates. Polymers such as polydimethylsiolxane; poly(ethylene-vingylacetate); acrylate based polymers or copolymers, e.g., poly(hydroxyethyl methylmethacrylate, polyvinyl pyrrolidinone; fluorinated polymers such as polytetrafluoroethylene; cellulose esters.
Polymer/drug mixture is applied to the surfaces of the stent by either dip-coating, or spray coating, or brush coating or dip/spin coating or combinations thereof, and the solvent allowed to evaporate to leave a film with entrapped rapamycin.
2. Experimental Stent Delivery Method—Delivery from Microporous Depots in Stent Through a Polymer Membrane Coating:
Stent, whose body has been modified to contain micropores or channels is dipped into a solution of Rapamycin, range 0.001 wt % to saturated, in organic solvent such as acetone or methylene chloride, for sufficient time to allow solution to permeate into the pores. (The dipping solution can also be compressed to improve the loading efficiency.) After solvent has been allowed to evaporate, the stent is dipped briefly in fresh solvent to remove excess surface bound drug. A solution of polymer, chosen from any identified in the first experimental method, is applied to the stent as detailed above. This outer layer of polymer will act as diffusion-controller for release of drug.
3. Experimental Stent Delivery Method—Delivery via Lysis of a Covalent Drug Tether
Rapamycin is modified to contain a hydrolytically or enzymatically labile covalent bond for attaching to the surface of the stent which itself has been chemically derivatized to allow covalent immobilization. Covalent bonds such as ester, amides or anhydrides may be suitable for this.
4. Experimental Method—Pericardial Delivery
A: Polymeric Sheet Rapamycin is combined at concentration range previously highlighted, with a degradable polymer such as poly(caprolactone-gylcolide) or non-degradable polymer, e.g., polydimethylsiloxane, and mixture cast as a thin sheet, thickness range 10μ to 1000μ. The resulting sheet can be wrapped perivascularly on the target vessel. Preference would be for the absorbable polymer.
B: Conformal Coating: Rapamycin is combined with a polymer that has a melting temperature just above 37° C., range 40°–45° C. Mixture is applied in a molten state to the external side of the target vessel. Upon cooling to body temperature the mixture solidifies conformably to the vessel wall. Both non-degradable and absorbable biocompatible polymers are suitable.
As seen in the figures it is also possible to modify currently manufactured stents in order to adequately provide the drug dosages such as rapamycin. As seen in FIGS. 1 a , 2 a and 3 a , any stent strut 10 , 20 , 30 can be modified to have a certain reservoir or channel 11 , 21 , 31 . Each of these reservoirs can be open or closed as desired. These reservoirs can hold the drug to be delivered. FIG. 4 shows a stent 40 with a reservoir 45 created at the apex of a flexible strut. Of course, this reservoir 45 is intended to be useful to deliver rapamycin or any other drug at a specific point of flexibility of the stent. Accordingly, this concept can be useful for “second generation” type stents.
In any of the foregoing devices, however, it is useful to have the drug dosage applied with enough specificity and enough concentration to provide an effective dosage in the lesion area. In this regard, the reservoir size in the stent struts must be kept at a size of about 0.0005″ to about 0.003″. Then, it should be possible to adequately apply the drug dosage at the desired location and in the desired amount.
These and other concepts will are disclosed herein. It would be apparent to the reader that modifications are possible to the stent or the drug dosage applied. In any event, however, the any obvious modifications should be perceived to fall within the scope of the invention which is to be realized from the attached claims and their equivalents. | Methods of preparing intravascular stents with a polymeric coating containing macrocyclic lactone (such as rapamycin or its analogs), stents and stent graphs with such coatings, and methods of treating a coronary artery with such devices. The macrocyclic lactone-based polymeric coating facilitates the performance of such devices in inhibiting restenosis. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Ser. No. 08/443,120 filed May 17, 1995, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates in general to the field of hypodermic needles, and in particular, to a hypodermic needle assembly having a prefilled syringe.
Hypodermic syringes having prefilled barrels and prefilled cartridges for use with syringe systems provide an alternative to filling the hypodermic needle on site. Prefilled syringes minimize packaging by eliminating the need for a separate vial of medication. This is of particular importance in the emergency room or ambulance where a variety of equipment must be stored in a limited area. In addition, the step of transferring the medicine from the vial to the syringe is eliminated. Reducing the number of steps required for an injection is of particular importance in the emergency room, hospital, ambulance or other environment where the medicine must be injected as quickly as possible. The large-bore needles used to extract the fluid from the vial are also eliminated, reducing the risks of accidental needle pricks during the handling of the syringe. The risk of contamination of the medicine is also reduced.
With many prefilled syringes, the barrel includes a membrane which seals the liquid within the barrel. The membrane may be ruptured, releasing the fluid for injection, by using a needle assembly to pierce the membrane or by applying sufficient pressure to burst the membrane. Typically, the prefilled syringe is supplied with the plunger projecting from the rear of the barrel, requiring additional space for packaging, shipment and storage of the device. Additional packaging may be required to secure the plunger in the extended position and prevent premature emptying of the barrel. Moreover, care must be taken to prevent damaging the plunger prior to use. Some available syringes include an outer shell which is coupled to a piston head. The fluid is dispensed by sliding the outer shell relative to the barrel to depress the piston head. Although this type of prefilled syringe may be less susceptible to damage, the outer shell must be retained in an extended position until the syringe is used.
Prefilled cartridges provide protection against contamination of the medicine and minimize the space required for storage and shipment of the cartridges since the cannula and plunger elements are separate from the cartridge. However, the overall space occupied by the different components of the syringe assembly is not reduced. Further, the prefilled cartridge must be loaded into a syringe assembly prior to use, requiring an additional step. The risk of contamination may also be increased unless care is taken to protect the critical surfaces of the syringe assembly and/or cartridge from airborne contaminants.
The hypodermic needle is one of the most dangerous tools in modern medicine. Common microorganisms, including deadly viruses, are known to be communicable through infected hypodermic needles. In the urgent environment of ambulances or hospital emergency rooms, used and exposed hypodermic needles present a hazard to medical workers or patients. An accidental stab or scratch produced by such needles can introduce dangerous viruses or other contaminants directly into a person's blood stream. Therefore, there is a need for protecting medical personnel and patients from exposed hypodermic needles.
Many solutions have been proposed to solve the problem. Most involve very complex, spring-loaded mechanisms for automatic needle retraction after injection. These are unsuitable for disposable syringes because of cost considerations. In addition, their intricate construction increases the chances of malfunctioning.
Another group of solutions proposes a manual retraction systems. These tend to be very inconvenient and cumbersome to operate. The number of steps to be performed by the person administering an injection is drastically increased. In addition, manual retraction systems, as well as the automatic ones referred to above, increase the number of parts on the front of the syringe barrel. This limits the range of angles from which the needle can be introduced under the patient's skin. In fact, with all the fixtures and attachments required for safe needle retraction, the operator is restricted to a ninety degree angle of entry. Under this angle the needle penetrates deep under the patient's skin and is frequently hard to withdraw.
Of course, the advantage of a shallower angle of entry has been recognized in the art. Many old-fashioned syringes have a needle-mounting snout located off-center for this very reason. Nonetheless, for technical reasons having to do with the retraction mechanism, no state of the art solution incorporates the concept of shallow entry angle and protection of the hypodermic needle.
SUMMARY OF THE INVENTION
In summary, one embodiment of the present invention combines the innovation of mounting a hypodermic needle on one side of a syringe, rather than in the center, with the idea of encasing or removing the needle after it has been used. Therefore, one embodiment of this invention teaches that a needle mounted on a carriage can slide within a sheath, where this sheath is mounted on the side of a syringe or other chamber filled with fluid. The needle can slide to one of three positions; in the first position, it is closest to the front of the syringe, and it is ready to be used. In this position, the carriage mounted to the needle is in the right position to trigger the chamber to open a side outlet and allow fluid to pass through the outlet, through a duct in the carriage, and out through the needle. In the second position, the outlet is closed, and the needle and carriage are reversibly retracted into the sheath. In a third position, the outlet is also closed, and the needle and carriage are retracted, even deeper into the sheath, irreversibly, so that the needle can not be made to protrude. This is the disposal position. In the most preferred embodiment the carriage and needle are locked into these three positions along a sliding track by means of flexible legs on the carriage which protrude into notches on the track. The operator frees the carriage and needle from these notches by depressing buttons to compress the legs.
This invention teaches that the entire sheath containing the carriage and needle may be removed from the chamber of fluid. Alternatively, the carriage and needle unit may be removable from the sheath. Both of these variations use reversible mounting mechanisms, such as mechanical snapping-on of parts.
In another embodiment, the present invention provides a syringe system which is particularly useful for prefilled applications where the syringe is supplied with the chamber of the syringe filled with an injection fluid. The fluid chamber has an outer wall and an outlet for dispensing fluid from the chamber. The syringe also includes a plunger assembly for expelling fluid from the chamber. The plunger assembly includes a plunger which is slidable through the chamber for creating positive pressures to cause ejection of a fluid from the chamber. The assembly also includes an actuator coupled to the plunger for movement of the actuator between a first position, with the actuator released for movement through the chamber relative to the plunger, and a second position, with the actuator in cooperative engagement with the plunger for driving the plunger through the chamber to create the positive pressures.
The method of this embodiment of the invention includes the steps of forming a chamber for retaining an injection fluid and slidably positioning a plunger assembly in the chamber. The plunger assembly includes a plunger which is spaced from an outlet of the chamber and an actuator for driving the plunger through the chamber. At least a portion of the actuator is initially positioned within the chamber between the outlet and the plunger. The method also includes the steps of substantially sealing the outlet of the chamber and injecting a fluid into the chamber between the outlet and the plunger. Preferably, the outlet is sealed by positioning the actuator in sealing engagement with the outlet of the chamber. Prior to use, the actuator is moved into interengagement with the plunger so that the actuator may be used to move the plunger through the chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional objects and features of the invention will be more readily apparent from the following detailed description and appended claims when taken in conjunction with the drawings, wherein:
FIG. 1 is a side view of the preferred embodiment of the invention;
FIG. 2 is a perspective view of the embodiment of FIG. 1, showing three states for the needle;
FIG. 3 is a perspective view of a part of the embodiment of FIG. 1, the carriage containing the needle;
FIG. 4 is a perspective view of how the needle in the embodiment of FIG. 1 is attached to the needle carriage;
FIG. 5 is a perspective view of the locking legs of the carriage of the embodiment of FIG. 1;
FIG. 6 is a cross-section view of the entire locking mechanism of the embodiment of FIG. 1;
FIG. 7 is a side view of an alternative embodiment of the invention;
FIG. 8 is a side view of an alternative embodiment in which the sheath is removable from the syringe;
FIG. 9 is a frontal view of the embodiment of FIG. 8;
FIG. 10 is a side view of an alternative embodiment in which the carriage is removable from the sheath;
FIG. 11 is a perspective view of an alternative embodiment of the invention;
FIG. 12 is a top plan view of another embodiment of the invention;
FIG. 13 is a top plan view of another embodiment of the invention, shown with the needle oriented in a plurality of positions relative to the fluid chamber;
FIG. 13A is a side plan view of another embodiment of the invention;
FIG. 14 is a cross-sectional view of a syringe assembly in accordance with another embodiment of the invention, shown packaged for shipment and storage;
FIGS. 15A and 15B are end views of the plunger assembly of FIG. 14;
FIG. 16A is a cross sectional view of a plunger assembly in accordance with another embodiment of the present invention;
FIG. 16B is an end view of the plunger of FIG. 16A;
FIG. 17 is a cross-sectional view of the syringe assembly of FIG. 14, shown with the actuator of the plunger assembly partially retracted;
FIG. 18 is a cross-sectional view of the syringe assembly of FIG. 14, shown with the actuator of the plunger assembly fully retracted;
FIG. 19 is a cross-sectional view of the syringe assembly of FIG. 14, shown prepared for an injection;
FIG. 20 is a cross-sectional view of the syringe assembly of FIG. 14, shown following an injection with the needle assembly retracted into the protective sheath;
FIG. 21 is a cross-sectional view of the syringe assembly of FIG. 14, shown with the needle assembly detached from the chamber disengaged for disposal;
FIG. 22 is a schematic view illustrating the method of supplying a prefilled syringe in accordance with this invention;
FIG. 23 is a cross-sectional view of a syringe assembly in accordance with another embodiment of the invention, shown packaged for shipment and storage;
FIG. 24 is a cross-sectional view of the syringe assembly of FIG. 23, shown with the plunger assembly prepared for an injection;
FIG. 25 is a cross-sectional view of a syringe assembly in accordance with another embodiment of the invention, shown packaged for shipment and storage; and
FIG. 26 is a cross-sectional view of another embodiment of the invention, shown with the needle assembly being applied to the chamber.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the preferred embodiment of the invention, which is illustrated in the accompanying figures. Turning now to the drawings, wherein like components are designated by like reference numerals throughout the various figures, attention is directed to FIGS. 1-6.
FIGS. 1-6 show an embodiment of a hypodermic syringe 6 in accordance with the invention. The hypodermic syringe 6 may be used to extract fluids or to inject fluids supplied in a vial, ampule or the like which is separate from the syringe. The syringe also may be prefilled, although the modifications shown in FIGS. 14-24 are preferred for prefilled applications. The hypodermic syringe 6 generally includes a syringe body 7 and a needle assembly 8 having a needle 30 which may be easily moved from the extended position shown in FIG. 1 to a retracted position with the contaminated needle safely contained within a protective sheath 22. As is shown in FIG. 1, the syringe body 7 and needle assembly 8 are formed as a single unit. After the used needle 30 has been retracted within the sheath 22, the entire unit may be safely discarded. In alternative forms of the invention, such as those shown in FIGS. 8-11, the syringe body 7 and needle assembly 8 may be separate components with the needle assembly being detachable from the syringe body for disposal of the needle. Providing the needle assembly 8 as a separate component is particularly useful when the hypodermic needle is used to extract a sample of fluid, such as blood, from the patient's body.
Turning particularly to FIG. 1, syringe body 7 includes a chamber 10 and a plunger 12 extending through the chamber 10. The chamber 10 is filled with injection fluid, although in applications where the hypodermic is used to collect fluids the chamber 10 may be empty. Near the front end 14 of chamber 10, within a side wall 16, there is an outlet 18. A valve, such as a check valve 20, is fixed in outlet 18 to control the flow of fluid through outlet 18. The chamber 10 has a central axis substantially aligned with the plunger 12.
The sheath 22 of the needle assembly 8 is positioned to one side of the chamber 10, with the central axis of the sheath offset from the central axis of the chamber 10. With this configuration, the syringe body 7 will not interfere with the orientation of the needle relative to the patient's body, allowing the needle to be inserted into the skin at a substantially small angle. In addition, this configuration is particularly suitable for embodiments of the invention in which the sheath is detachable from the chamber 10. Although positioning the needle assembly 8 to one side of the syringe body 7 is preferred, it should be understood that in other modifications of the invention the syringe body 7 may extend circumferentially around a major portion of the needle assembly 8 if desired. In the present embodiment, the sheath 22 is defined by the side wall 16 of the chamber 10 and two spaced flanges depending from the side wall 16 to form a U-shaped channel or recess 24. Alternatively, the sheath may include a bottom wall spaced from the side wall 16 of the chamber. Depending upon the length of the chamber 10 and the size of the needle 30, the recess 24 may extend along the entire length of the chamber as shown in FIG. 1 or the recess 24 may be shorter or longer than the chamber. In the embodiment shown in FIGS. 1-6, the sheath 22 is permanently mounted to or integrally or monolithically formed with the chamber 10. In other embodiments of the invention, the sheath 22 may be removably mounted to the chamber 10.
A carriage 36 mounted within recess 24 may be moved from one end of recess 24 to the other. The needle 30 is attached at the front end of carriage 36. The carriage preferably includes a conduit for delivering fluid to the needle 30. In the embodiment shown in FIG. 1, carriage 36 has a duct 38 which extends from the valve 20 to the needle 30, presenting the only path for fluid to flow between chamber 10 and needle 30. Two buttons 40A and 40B are provided on either side of the carriage 36 for controlling the position of carriage 36. They extend outside recess 24, with the stems of the buttons engaging two lateral slots 26 formed in the walls of sheath 22. Lateral slots 26 extend along the length of recess 24 and end before reaching the front end of recess 24. The carriage 36 may be moved along the recess 24 by sliding the buttons 40A and 40B along the slots 26. The front ends of the slots 26 prevent the carriage from failing out of recess 24.
As is shown in FIG. 2, the carriage 36 may be moved within recess 24 between three positions. In a ready-position 50, carriage is near the front end 14 of chamber 10. Duct 38 is aligned with the chamber outlet 18 (FIG. 1) and positioned to open valve 20 (FIG. 1), allowing fluid to flow from the chamber 10 to needle 30. In the standby-position 52, carriage 36 and needle 30 are completely retracted into recess 24, protecting the needle 30 against contamination. With the carriage 36 in the stand-by position, the needle 30 is positioned within the sheath 22 for the safe storage and handling of the unused device. However, in other forms of the invention the needle 30 may be supplied in the extended position shown in FIG. 1 with a removable sleeve covering and protecting the needle prior to use as is known in the art. As is described in more detail below, the carriage may be easily moved from the stand-by position 52 to the ready-position 50. After the needle 30 has been used, the carriage 36 may be retracted to the disposal-position 54. Unlike the stand-by position 52, the carriage 36 may not be moved forwardly from the disposal position 54 to either the stand-by position 52 or the ready position 50.
FIGS. 3 and 4 show a more detailed view of carriage 36. Buttons 40A and 40B jut out from either side of the carriage. On the upper surface of carriage 36 facing chamber 10, duct 38 ends in a dome-shaped distal end 42 formed to open the valve 20 and permit discharge of the fluid from the chamber 10. A nose-shaped connector 44 coupled to the proxima1 end of the duct 38 projects from the front end of the carriage 36. Needle 30 has a receptor 34 on its end which attaches firmly to connector 44. In this embodiment, connector 44 is a regular tube for snapping on hypodermic needles by their receptor 34. This snap-on mechanism is well-known in the art.
FIG. 5 shows the locking feature of carriage 36 which secures the carriage 36 in each of the positions 50, 52 and 54 shown in FIG. 2. Two elastic legs 46A and 46B extend outwardly from the back end of the carriage 36. Legs 46A and 46B are tapered, and jut out slightly beyond the width of carriage 36. Buttons 40A and 40B are attached to legs 46A and 46B in such a way that when button 40A is depressed, leg 46A bends inward, so that it no longer juts outward, and button 40B depresses leg 46B in a similar way. Of course, there are many other mechanical solutions for a locking mechanism adaptable to carriage 36. Corresponding grooves, notches, catches and other provisions for actuating such locking mechanisms can be easily incorporated on the side of the syringe or inside sheath 22.
The operation of the locking mechanism is shown in FIG. 6. The walls of the recess 24 are formed with a plurality of notches shaped to engage the legs 46A and 46B of the carriage 36 and retain the carriage in one of the positions 50 and 52. The first two notches, which are the ready-position notches 60A and 60B, are closer to front end 14. When the legs 46A and 46B engage the notches 60A and 60B, the carriage 36 is held securely in the ready position 50. The engagement between the legs and the notches prevents the carriage 36 from moving backwards, withstanding the force required to insert the needle into the patient's body. Once needle 30 has been used, buttons 40A and 40B are pressed together to disengage the legs 46A and 46B from the notches 60A and 60B and the carriage 36 may be moved backwards. The notches 62A and 62B engage the legs 46A and 46B to retain the carriage 36 in the standby-position, preventing forward and backward movement of the carriage until the buttons 40A and 40B are depressed. When the operator moves carriage 36 backwards to disposal-position 54, the legs 46A and 46B are moved past two tabs 64A and 64B which catch carriage 36 and prevent it from moving forwards again. In this embodiment, the tabs are leaf springs. However, the configuration of the tabs are subject to considerable variation. Because sheath 22 is closed at the back end, carriage 36 is thereby fixed in position; there is no mechanism for moving it either forwards or backwards. However, in other embodiments of the invention the sheath may be open at its back end to allow carriage 36 and needle 30 to be removed from the recess 24.
The outlet 18 and duct 38 provide a passageway for transporting fluid between the chamber 10 and the needle 30. In the embodiment shown in FIGS. 1-6, the chamber 10 is formed with an outlet which extends straight through the chamber wall. FIG. 7 shows an alternative embodiment of the chamber 10 in which the outlet 18 is replaced by a conduit 110 extending from an interior opening 118 in the front wall of chamber 10 to an exterior opening 112 on the side wall 16. With this embodiment, all the fluid held within chamber 10 may be injected into the patient's body. With the embodiment shown in FIGS. 1-6, the fluid between the front end 14 of the chamber and outlet 18 would become trapped within the chamber once the plunger 12 had passed outlet 18.
FIG. 8 shows an embodiment of the invention in which the needle assembly 8 is detachable from chamber 10. In this embodiment, needle assembly 8 includes a sheath 22 which is mounted onto chamber 10 by a secure mounting system which allows the operator to remove sheath 22 after needle 30 has been used and safely retracted within the sheath. As is shown in FIG. 8, chamber 10 has a front wall 100 and a back wall 102 which extend beyond the side wall of the chamber. The sheath 22 may be snapped into the space between the front and back walls 100 and 102. The sheath 22 may be easily detached from the chamber 10 by pulling the sheath from between the front and back walls. In other embodiments, other means may be used to removably or permanently couple the sheath to the chamber. For example, sheath 22 may be screwed on, twisted on, slid on, magnetically placed onto chamber 10, or permanently affixed by adhesive, ultrasonic welding, and the like instead of snapping the sheath 22 in place.
FIG. 9 shows a frontal view of the embodiment of FIG. 8. Front wall 100 has a mouth 104 which allows the needle 30 to project from the front wall 100. Preferably, the carriage 36 is prevented from passing through the mouth 104. However, if desired the front ends of slots 26 may be used to interrupt the forward progress of the carriage. In the present invention, the mouth 104 is generally U-shaped slot extending upwardly from the lower edge of the front wall 100. Alternatively, the mouth may be provided as an aperture formed in the front wall 100.
FIG. 10 shows another embodiment of the invention in which sheath 22 is integrally formed with or permanently mounted to the fluid chamber 10. The lower surface (not shown) of the sheath is open for insertion of the carriage 36 into the sheath 22. Sheath 22 has an opening 80 through which the stems of the buttons 40A and 40B may pass. Opening 80 has a pair of one-way keepers or tabs 82 which bend inward when the carriage 36 is inserted into the sheath. After the stems of the buttons 40A and 40B pass through the opening 80, the keepers 82 return to their original shape and block carriage 36 from coming out of sheath 22 again. In this modification, the sheath 22 may consist of two spaced flanges depending from the chamber 10, with the engagement between the buttons 40A and 40B and the slots retaining the carriage 36 in the sheath. Alternatively, the sheath may have a bottom wall which is formed with an opening of sufficient size to receive carriage 36.
The advantages of positioning the needle 30 to the side of the fluid chamber 10 are further described in relation to the modifications shown in FIGS. 11-13. With these embodiments, the needle carriage may be efficiently mounted to the chamber 10 and removed from the chamber after the needle 30 has been used. A shallow angle of entry may be obtained by orienting the assembly with the needle carriage between the patient's skin and the chamber 10. As is described in relation to FIG. 13, the needle position is not restricted to a parallel orientation relative to the chamber 10.
In the modification shown in FIG. 11, carriage 72 does not slide along the syringe. Instead, the carriage 72 is mounted by screwing into the syringe. In this embodiment, chamber 10 has a socket 70 jutting out and surrounding an outlet (not shown). The spout 76 of carriage 72 securely engages the socket 70. In the present embodiment, the spout 76 and socket 70 are formed with screw threads which cooperate to securely retain the spout within the socket. However, various other means may be used to secure the carriage to the chamber 10 including, but not limited to, snap beads, slot-key structures, locking nuts, and the like. Carriage 72 is thereby mounted securely onto chamber 10, and duct 38 (not shown) is aligned with the outlet of the fluid chamber. After needle 74 has been used, carriage 72 is screwed off and disposed. This embodiment saves materials and costs of manufacturing.
In the embodiment shown in FIG. 12, carriage 72 is mounted to the fluid chamber 10 by positioning spout 76 in the mounting ring or socket 70 on the chamber 10. The spout 76 and socket 70 are formed with cooperating engagement means suitable for securing the two members together such as screw threads, snap beads, slot-key structures, locking nuts, and the like. The back surface of needle carriage 72 is shaped to engage a locking mount 80 carried by the fluid chamber 10 to prevent rotational movement of the needle carriage 72 relative to the chamber 10 during insertion of the needle 30. In the illustrated embodiment, the protruding bead 82 on the locking mount 80 seats in a pocket 79 formed in the back surface of the needle carriage 72. However, it should be understood that the position of the bead 82 and the pocket 79 may be reversed. Moreover, other suitable engagement means may be used to anchor the needle carriage 72 to the locking mount 80.
A U-shaped sheath 85 is slidably mounted to the needle carriage 72. After the needle has been used, the sheath 85 slides along the carriage 72 and across the needle 30 until the contaminated tip of the needle is positioned within the sheath. Unlike the needle assemblies of the prior art, mounting the needle carriage to the side of chamber 10 allows the sheath to be separate from the chamber 10, providing greater flexibility in the size of the sheath 85 and the overall assembly.
The needle position is not restricted to a parallel orientation relative to the chamber 10. FIG. 13 shows an embodiment of the invention in which the needle 30 may be held in several positions such as parallel to the longitudinal axis of the chamber 10, perpendicular to the chamber 10 or at any other angle. The needle carriage 72 is mounted to the fluid chamber 10 through the interengagement of a mounting ring or socket 70 and a spout 76. The mounting ring 70 is indexed to interlock with the spout 76 on the carriage and securely retain the needle in several different positions. Orienting the needle 30 at an angle relative to the axis of the chamber 10 allows pressure to be placed on the chamber 10 during use of the assembly, such as when extracting blood, without forcing the needle further into the patient. Various means may be used to secure the spout 76 and indexed mounting ring 70 together. For example, the mounting ring 70 may include a slot-key structure configured to permit rotation of the socket between two or more interlocked positions. In another example, the socket may be formed with a button which projects through a hole formed in the mounting ring 70 to lock the needle carriage in the desired position. By depressing the button, the button may be released and the spout rotated to bring the button into engagement with another hole formed in the mounting ring. In addition, other suitable means may be used for interlocking the spout and the mounting ring in one of several different positions.
FIG. 13A shows an embodiment of the invention in which the needle 30 has a perpendicular orientation relative to the chamber 10A. This embodiment is particularly suitable for use with a sealed vacuum container 175 which is often used when extracting a sample of blood. The container 175, which is sealed with a rubber top 176, is moved into the chamber 10A until the needle 30A pierces the top 176. The needle carriage 72 is mounted to the chamber 10A using suitable securement means such as the spout 70A of the chamber and the socket 76A of the needle carriage 72A. Blood or other fluid drawn into the needle 30 is transported through the needle 30A and into the container 175. After the container 175 has been filled, the protective sheath 85 may be moved onto the needle 30 to provide protection against accidental contact with the needle.
In the embodiments shown in FIGS. 11-13, the mounting ring or socket 70 is provided on the fluid chamber 10 while the spout 76 is positioned on the needle carriage 72. However, it should be understood that in other modifications the needle carriage 72 may have the mounting ring 70 while the fluid chamber 10 may be formed with the spout.
The protection system of the syringe of the present invention should not be limited to the specific embodiments shown in the Figures. Many other variations are possible. For example, the check valve can be replaced with a slide gate, or with any other mechanism which synchronizes the opening of an outlet for fluid with the presence of an external duct to receive the fluid; another alternative is a film covering which is penetrated once the outlet contacts the external duct. In fact, because of the presence of the plunger, fluid will not flow unless the plunger is pushed or pulled, so the check valve may be even unnecessary. Mother variation is a different mechanism for locking the carriage. For example, the legs could jut into notches in the lateral slots, or notches in the side wall, rather than notches in the walls of the recess. The buttons 40A and 40B may be replaced by one button on the top which controls one leg. In fact, any locking mechanism can be used which locks a sliding carriage to a track based on the position of the carriage within the track, such as a retracting pen mechanism. Similarly, the tabs which prevent the carriage from sliding out once the carriage attains the "disposal-position" may be any mechanism which allows unidirectional sliding of an object within a track.
FIGS. 14-21 show another embodiment of a hypodermic syringe 6 in accordance with the invention. The syringe 6 is particularly suitable for prefilled applications where the syringe is supplied to the consumer with the chamber filled with an injection fluid. The prefilled chamber offers several advantages such as the elimination of a separate package for the injection fluid and the elimination of the step of filling the chamber prior to the injection. The chamber may be supplied with a precisely measured amount of the fluid, further improving the efficiency of the injection process by eliminating the step of carefully measuring the amount of fluid which is drawn into the chamber from the supply vile.
The prefilled hypodermic syringe 6 shown in FIGS. 14-21 generally includes a chamber 10 filled with a selected fluid and a needle assembly 8. As is described in more detail in relation to FIGS. 8-9, the needle assembly 8 generally includes a protective sheath 22 which is detachable from the chamber 10 for disposal. However, if desired the sheath 22 and chamber may be a unitary structure as shown in FIGS. 1-6 or other configurations of the needle assembly 8, such as those shown in FIGS. 10-13, may be employed. The needle 30 is safely retained in the protective sheath 22 until the needle carriage 36 is secured in the position shown in FIG. 19. After the injection, the needle carriage 36 may be released and moved to the disposal position shown in FIGS. 20 and 21, with the needle safely retracted into the protective sheath.
In this embodiment, chamber 10 is formed with the conduit 110 (shown particularly in FIG. 7) for transporting fluid from an opening 118 in the front wall of the chamber to the duct 38 (FIG. 4) formed in the needle carriage 36 when the carriage is retained in the position shown in FIG. 19. The rear wall of chamber 10 is formed with an opening 122 which is sealed by a cap 124.
Syringe 6 includes a plunger assembly 130 having a plunger head 132 and an actuator 134. The actuator is initially separate from and movable relative to the plunger 132. FIG. 14 shows the actuator 134 substantially disposed in the chamber 10, while FIGS. 17 and 18 show the actuator in partially and fully retracted positions, respectively, relative to the chamber. Actuator 134 includes an elongated body 136 which extends through openings in the plunger head 132 and cap 124. The elongate body has a shaped tip 138 (FIG. 15A) which is adapted to seal the opening 118 formed in the front wall of the chamber 10 when the actuator is fully inserted in the chamber as shown in FIG. 14. In this embodiment, the shaped tip 138 includes a plug 139 which extends through the opening 118, engaging the inner wail of the conduit 110 to provide an effective seal. The plug 139 is removed from the opening 118 when the actuator 134 is retracted, breaking the seal. The tip 138 and the conduit opening 118 may have other shapes within the scope of the invention. Moreover, other means may be used to seal conduit 110 although sealing the conduit 110 with the shaped tip 138 is preferred. FIG. 27 shows another embodiment of a shaped tip 138 which includes a plug 177 shaped to seal with the enlarged opening of a laterally extending conduit 110A.
The tip 138 is shaped to engage the plunger 132 when the actuator is moved to the fully retracted position shown in FIG. 18. It is to be understood that the configuration of tip 138 and plunger head 132 is subject to considerable variation within the scope of this invention. In the embodiment shown in particularly in FIG. 14, the tip 138 has a barbed configuration which allows the tip 138 to be pulled into a cooperatively-shaped socket 140 formed in the plunger 132. The tip 138 and socket 140 are shaped to interengage and prevent removal of the tip from the socket when the actuator 134 is moved in the opposite direction relative to the chamber 10. Once the tip 138 is securely retained in the socket 140, the actuator 134 may be used to drive the plunger head 132 through the chamber 10 to inject the fluid through needle 30. The cap 124 provides stability when the actuator 134 is retracted into engagement with the plunger 132 or used to drive the plunger head through the chamber 10. In other embodiments of the invention, other means may be used to reinforce the actuator 134. Actuator 134 preferably includes means such as push plate 142 to facilitate the manipulation of the plunger assembly 130 when retracting the actuator 134 from the chamber 10 into engagement with the plunger 132 or driving the plunger 132 through the chamber. In the present embodiment, the push plate 142 is in the form of a planar disc. However, the push plate 142 may have other shapes as is known in the art.
Another embodiment of the plunger assembly 130 is shown in FIGS. 16A and 16B. The tip 138 of actuator 134 includes an enlarged flange 144 which engages the front of plunger head 132 to prevent the actuator from being pulled from the plunger when retracted prior to use. The actuator tip 138 is provided with a threaded plug 139 to prevent inadvertent removal of the plug from the outlet during handling of the syringe. The threaded plug 139 may be used with the chamber 10 shown in FIG. 14, with the threaded plug being force fit into the outlet 118. The plug 139 may also be used with a chamber (not shown) having a threaded outlet. Depending upon the material employed and the height of the threads, the plug may be pushed into the outlet with the threads slipping into interengagement or the plug may be twisted into the threaded outlet. The plug 139 may be removed from the outlet by forcefully retracting the actuator 134 or by twisting the actuator to unscrew the plug from the outlet for sealing the outlet to the chamber. The actuator 134 further includes oppositely disposed beads 146 which project from the elongate body 136 of the actuator. The actuator body 136 and beads 146 are movable through the resilient plunger 132 as the actuator is retracted from the chamber of the syringe.
The actuator 134 engages a backplate 147 of plunger 132 to drive the plunger through the plunger and expel liquid from the syringe. The backplate 147 may be a separate component or, if desired, may be provided by the cap 124 shown in FIG. 14. The backplate 147 is formed with an elongated opening 148 which is shaped to permit passage of the actuator body 136 and beads 146 when the beads are substantially aligned with the longitudinal axis of the opening 148. Once the beads have been pulled through the opening 148, the actuator 132 is rotated about 90° to position the beads 146 between a pair of spaced ridges 149. The beads 146 engage the backplate 147, allowing the actuator to drive the plunger 132 through the chamber when the actuator is moved in a forward direction. While the ridges 149 prevent inadvertent rotation of the actuator 134 during use of the syringe, it is to be understood that the configuration of the backplate 147 may be subject to considerable variation.
With the plunger assembly 130 of the present invention, the actuator 134 is initially movable relative to the plunger head, allowing the actuator to seal the outlet of the filled chamber, simplifying the structure of the syringe, and allowing the actuator to be substantially positioned within the chamber to reduce the overall size of the syringe. After the actuator is retracted from the chamber, the actuator engages the plunger head for driving the plunger through the chamber. While the figures illustrate two embodiments of a plunger assembly 130, it is to be understood that the actual configuration of the assembly and the engagement means used to secure the plunger to the actuator are subject to considerable variation within the scope of this invention.
The chamber, as supplied to the consumer, is filled with an injection fluid. Preferably, the prefilled chamber 10 contains a measured amount of fluid for a single injection. Supplying the fluid in pre-measured quantities offers several advantages including improving the efficiency of the injection process, minimizing the risk of injecting an improper amount of fluid, and reducing waste of the injection fluid. However, if desired the syringe may contain more than one application of the injection fluid.
The syringe 6 preferably includes means for filling the chamber 10 with fluid prior to shipment. In the embodiment shown in FIGS. 14-21, actuator 134 is formed with a conduit 150 having an outer opening 152 (FIG. 15B) formed in the push plate 142 and an inner opening 154 formed in the elongate body 136 of the actuator. The inner opening 154 is located so that when the actuator is fully inserted into the chamber 10 as shown in FIG. 14, the inner opening 154 is spaced inwardly of the plunger 132. A hollow tube (not shown) is preferably inserted through bore 156 defined by holes formed in the push plate 142, the cap 124 and the plunger head 132 to permit air to escape from the chamber during filling. Plunger 132 is preferably formed of a material which seals the opening in the plunger when the tube is withdrawn. The chamber 10 may be filled with fluid by injecting the fluid through the conduit 150. After the chamber has been filled, the opening 152 is sealed by a plug, membrane of other suitable means.
Other means may be used to fill the chamber with fluid. The side wall of the chamber may be formed with a port for filling the chamber. The port may be sealed by a plug, membrane or other sealing member after the chamber 10 had been filled with the injection fluid. The conduit 110 may also be used to fill the chamber with fluid by positioning the actuator 134 with the shaped end 138 spaced from the opening 118. Once the chamber is filled, the actuator is fully inserted into the chamber to bring the shaped end 138 into sealing engagement with the conduit 110.
As is shown particularly in FIG. 14, the syringe 6 may be enclosed within an outer package 160 sealed to the exterior flange 162 of chamber 10 and an outer cap 164. Package 160 and cap 164 provide a sterile environment protecting syringe 6 from the risk of contamination. The construction of the sterile packaging is subject to considerable modification within the scope of the present invention. For example, the outer cap 164 may be eliminated. FIG. 25 shows an embodiment in which a seal membrane 164A which extends between the package 160 and the push plate 142 to seal the outer package 160 to the chamber 10 and the push plate 142. In the embodiment shown in FIG. 25, the push plate 142 preferably has a diameter equal to or larger than the diameter of the chamber 10. In other modifications of the invention, the push plate 142 may fit within the outer package 160.
When the actuator 134 is retracted, removing the plug 139 of the shaped tip from the opening 118, a small amount of air will be pulled through the conduit and into the chamber 10. This air may be easily expelled from the chamber by pointing the needle 30 in an upward direction and depressing the plunger assembly 130 until liquid flows through the needle as is known in the art. In some applications, it may be desirable to isolate the injection fluid within the chamber from contaminants which may be carried by the air, As is shown particularly in FIG. 14, the space between the syringe 6 and the outer package 160 may be filled with a quantity of a sterile, inert gas generally indicated at 166., After the outer cap 164 is removed but before the seal between the outer package 160 and the flange 162 is broken, the actuator 134 is moved to the fully retracted position drawing some of the sterile air into the chamber as is shown in FIGS. 18 and 19. Once the actuator 134 is fully retracted, the outer package 160 may be removed and the sterile gas expelled from the chamber 10.
FIG. 22 schematically illustrates the method of supplying a prefilled syringe in accordance with this invention. The syringe 6 manufactured by a manufacturer 170 and shipped to a pharmaceutical source 172 where the chamber 10 is filled with injection fluid. The chamber may be filled using a conduit 150 formed in the actuator 134, a port formed through the wall of the chamber, the conduit 110 in the front end of the chamber 10, or other suitable means. After filling, a sterile plug, membrane or other sealing member may be applied to seal the openings to the chamber 10. If the conduit 150 is employed to fill the chamber 10, the outer package 160 may be sealed to the chamber and filled with sterile gas by the manufacturer 170. With the other filling methods, sterile outer packaging may be applied at the pharmaceutical source 172 after the chamber has been filled. The pharmaceutical source 172 may also apply the outer cap 164 or seal membrane 164A to the syringe 6.
The filled syringe 6 is shipped, directly or indirectly, from the pharmaceutical source 172 to the user 174 which may be a hospital, urgent care center, doctor's office, ambulance, patient, or the like. The user pulls the actuator 134 into engagement with the plunger head 132, removes the sterile packaging, moves the needle assembly 8 into the ready position and expels any air from the chamber. The syringe 6 is now prepared for the injection.
In the embodiment shown in FIGS. 14-21, the sheath 22 is detachable from the chamber 10. The chamber 10 and sheath 22 may be supplied to the pharmaceutical source 172 in a single package with the needle assembly 8 coupled to the chamber. The two components may be supplied separately to the source 172. Alternatively, as is indicated in FIG. 22, the manufacturer 170 may supply the needle assembly 8 directly to the user 174 and the empty chamber 10 to the pharmaceutical source 172, with the user snapping the needle source onto the chamber prior to the injection. As is discussed above, if desired the protective sheath may ago be an integral part of the chamber 10 as is shown for example in FIGS. 1-6.
After the injection, the user 174 retracts the needle 30 into the protective sheath 30 by moving the needle carriage 36 to the disposal position shown in FIGS. 20 and 21. With the syringe 6 of the embodiment shown in FIGS. 14-21, the protective sheath 22 may be removed from the chamber 10 as is shown in FIG. 21 and disposed in the garbage bin designated for sharp objects and the chamber 10 disposed separately. However, it is to be understood that the syringe 6 may be disposed as a single unit if desired.
Utilizing the plunger assembly 130 with the protection system of the previously described embodiments is of particular advantage in that it substantially eliminates the risk of accidental contact with a used needle. Moreover, the needle assembly 8 of this invention may be used to provide syringe 6 with a compact package. The needle 30 may also be efficiently and rapidly deployed with needle assembly 8. However, it is to be understood that plunger assembly 130 of this invention may be advantageously used with other types of needle assemblies.
FIGS. 23 and 24 show another embodiment of a syringe 6 in accordance with this invention. The syringe 6 includes a chamber 10 which may be used with the plunger assembly 130 described in relation to FIGS. 14-21. A conical tip 182 provided on the front wall of the chamber 10 is formed with a bore 184 for dispensing fluid from the chamber 10. A needle assembly (not shown) is secured to the conical tip 182 by friction or by a lure locking mechanism as is known in the art. The bore 184 in the chamber is initially sealed by the shaped tip, 138 of the actuator 134. The seal is broken by retracting the actuator from the &amber. The actuator 134 is retracted until the shaped tip 138 is pulled into engagement with the plunger head 132. Thereafter, the plunger assembly 130 may be used to dispense fluid from the chamber as is described in relation to FIGS. 14-21. If desired, the syringe 6 may include outer package 160 sealed to the chamber 10, an outer cap 164, seal membrane 164A or the like, and a sterile gas 166 filling the space between the outer package and the chamber.
While the present invention has been described with reference to a few specific embodiments, the description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims. | A hypodermic syringe and method of filling the syringe with an injection fluid. The syringe includes a fluid chamber for retaining an injection fluid and a plunger assembly for expelling fluid from the chamber. The plunger assembly includes a plunger slidably disposed in the fluid chamber for creating positive pressures to cause ejection of a fluid from the chamber and an actuator coupled to the plunger for movement of the actuator between a first position with the actuator released for movement of the actuator through the fluid chamber relative to the plunger and a second position with the actuator in cooperative engagement with the plunger for driving the plunger to create the positive pressures. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 60/362,992, filed Mar. 11, 2002 for “Integrated System for Examination, Diagnosis, Mapping, and Treatment of Prostate Problems.”
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to medical devices. It relates particularly to a holistically integrated ultrasonic system and process for examining, mapping, diagnosing, and treating diseases of the prostate gland in a male human, especially prostate cancer.
[0004] 2. Description of the Related Art
[0005] Prostate gland problems are widespread in the male population, especially the older male population. In particular, benign prostatic hyperplasia (BPH) and prostate cancer are all-too-common in men over 50 years of age. Indeed, prostate cancer is the cause of death in about 40,000 men each year, making it the Number Two cancer killer of men in the United States, second only to lung cancer. However, if prostate cancer is detected early and treated effectively, the chance of survival of one afflicted with this disease improves significantly. Unfortunately, methodS of detection of prostate cancer employed today are found seriously wanting, even in the hand of the highly skilled, as many early stage cancers still go undetected and/or an undue multiplicity of painful biopsies are required for diagnosis.
[0006] In an attempt to enhance the efficiency and efficacy of methods and systems of detection of prostate cancer, medical science turned to ultrasonics, and for several years ultrasonics has been applied in accomplishing diagnostic examinations of the prostate gland of the human male. As examples of advances made in this and related are as are the following U.S. Pat. Nos. 5,282,472; 5,398,690; 5,810,731; 5,952,828; 5,178,147; 5,919,139; 5,952,828; and 6,165,128. Notwithstanding the achievements of these inventions, the fact remains that no examining system or technique presently exists which provides the high degree of resolution and the accompanying precision which are absolutely necessary for an accurate diagnosis of prostate cancer, nor is the required repeatability of result achieved. Moreover, no technique, method, or system of the related art provides a holistically integrated ultrasonic approach which combines examining, mapping, diagnosing, and treating diseases of the prostate gland, especially cancer, in a male human, with a minimum of physical and mental discomfort.
SUMMARY OF THE INVENTION
[0007] It is accordingly a primary object of the present invention to obviate the disadvantages presented by systems and processes of the Related Art. This object is achieved, and attending benefits are acquired, by the provision of a holistically integrated ultrasonic system for examining, mapping, diagnosing and treating diseases of the prostate gland in a male human.
[0008] The first factor in the holistically integrated ultrasonic system of the present invention is means to reliably detect and map prostate cancer in early stages. However, success in the area of reliable detection and mapping will not be readily accepted and utilized appropriately, unless a second factor is integrated into the system. The second factor (a highly reliable follow-on biopsy or the application of a precisely guided reactive sensor to cancer tissue contact) is the means to reliably confirm the findings of the first factor.
[0009] Delivery of an integrated system comprising the above two factors yields opportunities to treat prostate cancer at times when the probability for successful treatment is high. Therefore, the present invention includes a third factor that provides for vastly improving the results of today's treatment modalities, as well as the introduction of new, effective, and patient friendly treatment modalities for prostate cancer in early stages.
[0010] To achieve consistent and reliable detection across the total spectrum of prostate cancer conditions, the present invention includes a fourth factor, which is an expert system, which provides the ability to utilize and integrate, in real time, data from several sensor inputs with several analytical techniques (this is not feasible with the limitations of human performance, but is achievable with the present expert system). The fifth factor in the instant system is cost-effectiveness to lower the overall health care cost associated with prostate cancer detection and treatment.
[0011] In the operation of the holistically integrated ultrasonic system according to the present invention, the following are applied:
[0012] (1) More than one ultrasonic sensor package working together in an integrated manner;
[0013] (2) Multiple analytical techniques;
[0014] (3) A constant, effective medium for superior ultrasonic sensor performance;
[0015] (4) High frequency ultrasound versus the lower frequency used in today's technology;
[0016] (5) Level-of-suspicion prostate cancer mapping;
[0017] (6) An automated slave biopsy subsystem with precision targeting; and
[0018] (7) A design philosophy to create a friendly patient and doctor experience.
[0019] As a result, the present invention has the capacity to:
[0020] (1) Provide early prostate cancer detection when the cancer or cancers are small;
[0021] (2) Automatically and clearly identify what has changed between successive examinations;
[0022] (3) Track treatment impact in real time for certain treatment modalities, and for others, to provide tracking over different time periods;
[0023] (4) Provide new, patient friendly, treatment options;
[0024] (5) Produce the matching of system output with pathology findings as proof of system performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] [0025]FIG. 1 is a schematic view of the overall system of the present invention, showing the major elements thereof.
[0026] [0026]FIG. 2 is a sectional, schematic, anatomical view showing both transrectal and transurethral systems in place in the rectum and the prostatic urethra respectively. It also shows an overlapping beam pattern from the two ultrasound systems with a detected tumor being sonically illuminated from both sides. It further shows a slaved biopsy needle deployed into said tumor.
[0027] [0027]FIGS. 3A, 3B and 3 C are cross-sectional schematic showing in the beam patterns emanating from each ultrasound system (transrectal and transurethral) separately and then in the actual overlapping pattern. Each pattern is superimposed on an outline of a diseased prostate showing the bi-directional scanning of a tumor section lying in the scan plane.
[0028] [0028]FIGS. 4A, 4B and 4 C are a schematic showing a top view, a side view and a cross-sectional view of a chair mechanism according to the present invention.
[0029] [0029]FIGS. 5A, 5B and 5 C show the same three views of the chair, but define the locations of the multiple actuators which produce the excitation sound waves used for the dynamic elastography feature according to the present invention.
[0030] [0030]FIG. 6 is an illustration of the impingement of elastography exitation pressure waves arriving at an area of differential stiffness, so that by varying the direction, frequency and power of the impinging waves, it is possible to maximize the ultrasonically detectable differential vibration of a tumor thus produced.
[0031] [0031]FIGS. 7A, 7B and 7 C show the same three views of the chair, but define the locations of the field generating elements for the magnetic position sensing system used in conjunction with the floating transrectal probe, shown in FIG. 8.
[0032] [0032]FIG. 8 is a sectional, schematic, anatomical view showing the floating transrectal prove in situ. The drawing shows the relationship of the magnetic field produced by generating elements to the sensing coils located at either end of the floating probe.
[0033] [0033]FIG. 9 is a sectional, schematic, anatomical view showing the floating transrectal prove in situ within the body.
[0034] [0034]FIG. 10 is a sectional, schematic, anatomical view showing both the transrectal and the transurethral probes in situ with the special diagnostic needle deployed into a detected tumor.
[0035] [0035]FIG. 11 is a sectional, schematic, anatomical view showing the transurethral catheter/catheter feeder assembly in situ. The drawing shows the fiber optic viewer/guide in situ within the catheter and protruding into the urinary bladder. The upper end of the fiber optic terminates in a small video camera which feeds a display used by the doctor for guidance and to assist in diagnosis. The water feed line is shown attached to the catheter feeder.
[0036] [0036]FIG. 12 is a sectional, schematic, anatomical view showing the same view as in FIG. 11 but with the fiber optic viewer/guide withdrawn from the catheter/catheter feeder assembly.
[0037] [0037]FIG. 13 is a sectional, schematic, anatomical view showing the same view as in FIG. 12 but with the transurethral ultrasound prove inserted through the catheter feeder into the catheter.
[0038] [0038]FIG. 14 is a sectional, schematic, anatomical view showing a close-up cross section of the catheter within the urethra. The distal opening of the catheter is shown with the fiber optic viewer/guide protruding through the distal opening.
[0039] [0039]FIG. 15 is a sectional, schematic, anatomical view showing the details of the catheter/catheter feeder assembly.
[0040] [0040]FIGS. 16A and 16B are sectional, schematic views showing a front pseudo-perspective and a side cross sectional view of the transrectal probe.
[0041] [0041]FIGS. 17 and 18 are sectional, schematic views showing the relationship of the dual beams emitted by the dual ultrasound scanners in the transrectal ultrasound probe. As the beams sweep across a tumor they cause different angles of acoustic shadow as shown.
[0042] [0042]FIGS. 19, 20 and 21 are sectional, schematic views showing three cross sections through the transrectal probe.
[0043] [0043]FIG. 22 is a sectional, schematic, view showing a side view of a condom covering the entire body of the transrectal probe.
[0044] [0044]FIG. 23 is a sectional, schematic view illustrating that the transrectal probe body is flexible in the saggital plan in the region of the curved neck.
[0045] [0045]FIG. 24 is a sectional, schematic, anatomical view showing the transrectal probe body in situ within the body. The drawing illustrates that the slaved biopsy needle penetrates the condom when it is deployed.
[0046] [0046]FIGS. 25A and 25B are sectional, schematic views showing the method by which the transrectal probe body is removably attached to the slaved biopsy needle mechanism housing. The non-symmetrical nesting inner and outer cone docking design guides the transrectal probe body to the proper position and alignment on the slaved biopsy needle mechanism housing and the magnetic latch holds it in place. These views show the elements before engagement.
[0047] [0047]FIG. 26 is a sectional, schematic view showing the same elements as in FIGS. 25A and 25B after engagement is complete.
[0048] [0048]FIG. 27 is a sectional, schematic view showing the slaved biopsy mechanism within the housing. The drawing illustrates the relationship of the moving parts of the mechanism at the nominal rest position.
[0049] [0049]FIG. 28 is a sectional, schematic view showing the same elements as in FIG. 27 with the angular mechanism at the extreme of its travel.
[0050] [0050]FIG. 29 is a sectional, schematic showing the same mechanism as in FIGS. 27 and 28 as it is carried within an angularly adjustable housing to facilitate optimal engagement with the patient regardless of anatomical variation.
[0051] [0051]FIGS. 30, 31, 32 , and 33 are sectional, schematic, anatomical views showing a sequence of the operation of a special tool with is deployed into a detected tumor. FIG. 30 shows a macerating cutter deployed within the tumor. FIG. 31 shows the tool reducing the volume containing the tumor to a liquid state. FIG. 32 shows the liquid extracted leaving a cavity where the tumor was. FIG. 33 shows the cavity filled with a collagen gel derived from the patients own tissues and carrying the appropriate dosage of anti-cancer drugs.
[0052] [0052]FIGS. 34, 35, 36 and 37 are sectional, schematic, anatomical views showing a similar set of sequences as in FIGS. 34 - 37 . These drawings differ only in that instead of filling the cavity, a vacuum system is used to collapse the cavity. A tissue adhesive is then used to seal the opening.
[0053] [0053]FIG. 38 is a perspective view showing the cutting mechanism of the slaved biopsy needle.
[0054] [0054]FIGS. 39, 40 and 41 are a three-part cutaway, side view of the biopsy needle showing how the forward movement of the slider pushes the blades to follow the curved guides and meet at the needle tip. The needle is then extracted containing the tissue sample.
[0055] [0055]FIGS. 42 and 43 are a set of perspective drawings of the square-end cutting biopsy needle. FIG. 43 shows the open end of the needle as it would appear during the harvesting phase of a biopsy. FIG. 42 shows the cutting blades fully extended to cut off and enclose the tissue sample.
[0056] [0056]FIGS. 44A, 44B, 44 C, and 44 D are a set of drawings showing the square cross section of the needle and the fit of the cutting blades within the side plate guides.
[0057] [0057]FIG. 45 is a perspective view of an alternate curved biopsy needle.
[0058] [0058]FIG. 46 is a sectional, schematic, anatomical view showing a patient in position of the integrated patient support platform.
DETAILED DESCRIPTION OF THE INVENTION
[0059] Following is a listing of elements constituting the system of the present invention, along with their corresponding reference numerals, as employed in the accompanying drawings.
1 patient chair 2 transurethral actuation mechanism 3 control panel 4 data display monitor 5 transrectural actuation mechanism 6 chair vertical movement 7 chair angle adjustment mechanism 8 overall urotech system 9 a, b duplex support structure a) chair b) transrectal system 10 electronics cabinet, including software package 11 transurethral probe support arm 12 foley balloon on transurethral catheter 13 transurethral catheter 14 a, b dual transrectal ultrasound scanners 15 ultrasound scan beam emitted by transurethral ultrasound scanner 16 ultrasound scan beam emitted by transrectal ultrasound scanners 17 chair pivot 18 transrectal ultrasound probe tip (entire) 19 frontal cavity within 18 20 support plate for chair pivot 21 a, b, chair hip fence adjusters 22 a, b chair hip fences 23 lateral chair adjustment 24 chair angle adjustment driver 25 chair saggital axis pivot point 26 in chair dynamic elastography exciters 27 belt mounted dynamic elastography exciters 28 belt 29 a, b hip fence mounted dynamic elastography exciters 30 stiffness node 31 representational dynamic elastography exciters 32 node showing movement in response to impinging pressure wave 33 floating transrectal probe umbilical 35 magnetic drive coils for magnetic position sensing system 36 magnetic field emitted by said coils 38 floating transrectal probe 40 a, b magnetic position sensing coils in floating trausrectal probe 41 prostate 42 urinary bladder 43 rectum 44 transrectal probe body (entire) 45 biopsy needle 46 tumor 47 transurethral ultrasound scanner 48 a, b bioimpedance sensing coils 50 tip of transurethral fiber optic viewer 51 head of penis 53 catheter feeder 54 water line to catheter feeder 55 transurethral video camera 56 transurethral fiber optic viewer 57 transurethral water line luer fitting 60 transurethral ultrasonic scanner movement 61 water bolus 62 urethra 63 upper sphincter of prostate 64 lumen of catheter 69 distal opening of catheter 70 instrument port of catheter feeder 71 sealing 0 ring of catheter feeder 72 luer fitting of catheter feeder 73 push in latch of catheter feeder 74 catheter coupler of catheter feeder 80 transurethral probe support structure 81 transrectal probe condom cover 82 head of condom cover 83 gimbal of needle guide 84 slot driver for transrectal dynamic elastography exciter 85 distal opening in condom head-for transrectal-fiber optic viewer 86 distal opening of water fill line 87 distal opening of air bleed line 88 lumen of fiber optic viewer passage 89 lumen of water line 90 lumen of air bleed line 91 driver for slot firing dynamic elastography exciter 92 water supply 95 water supply line into condom 98 seal around fiber optic viewer 99 transrectal fiber optic viewer 100 transrectal video camera 101 a, b ultrasound beams emitted by transrectal ultrasound scanners 14a, b 102 acoustic shadow 103 bleed air outlet catch container 104 thermal needle 105 volume to be necrotized 109 transrectal docking support structure 110 inner docking cone 111 lower magnetic latch 112 upper magnetic latch 113 outer docking cone 120 slaved biopsy device support structure 121 rotary movement 122 angular movement 123 depth of penetration movement 124 needle drive 125 needle guide 126 slaved biopsy mechanism cover 130 macerating needle 131 macerating flail 132 cavity created by macerating flail 133 cavity filled with gel 135 collapsed cavity 180 endcutting biopsy needle (entire) 181 cross section of square needle 182 square slider 183 a, b tissue cuffing blades on square slider 184 pressure relief lumen 185 flexible push rod 186 a, b, c side view cutaway of needle showing movement of the tissue cutting capsule with the blades following the curve of the tip and meeting to shear off tissue sample. 187 a, b views of the tip of the needle showing details of the opening and the tapered edge fence along which the tissue cutting blades run. 188 alternative curved needle configuration.
[0060] Referring now to the drawings, FIG. 1 is a schematic view of overall system showing the major elements thereof. The entire system is identified as 8 . Subsystems are as follows: the adjustable, swiveling patient chair 1 is supported on vertical movement 6 which is in turn mounted on 9 a one of the duplex support structures. The second duplex support structure 9 b carries the transrectal actuation system designated as 5 . 5 is surmounted by the transrectal probe dock shown with transrectal probe 44 latched in place. Located behind and in fixed relationship to 9 a, b is the electronic cabinet 10 . On the end of cabinet 10 , which is adjacent to the position of the patient's groin area is mounted the transurethral actuation system 2 . Said transurethral actuation system 2 has 3 degrees of freedom: it can be pulled forward to intersect the central axis of the patient. It can be moved several inches along that axis to accommodate patient variability. It can also be moved in the vertical plane to permit the distal end of the transurethral drive support arm 11 to be positioned in the proper relationship to the head of the patient's penis. On the forward face of cabinet 10 is mounted data display monitor 4 and control panel 3 . Both monitor 4 and control panel 3 are at the distal end of an adjustable arm, permitting them to be positioned at the ideal position for the physician.
[0061] [0061]FIG. 2 is a sectional, schematic, anatomical view showing the probe portion 18 of transrectal probe body 44 in place in the rectum 43 and adjacent to the prostate 41 . The transrectal probe body 44 is shown as a transparency to show the one of the transrectal scanners 19 a, b passing through the base and into the cavity 20 . The second transrectal scanner 19 b is directly behind 19 a on the other side of the probe centerline. The transparency of 44 also shows the locating cone/gimbal support 88 within probe body 44 . The transurethral scanner 47 moves within the transurethral catheter 52 which has been inserted by the physician through the urethra 61 and the prostate 41 into urinary bladder 42 where it is anchored by foley balloon 12 . Overlapping ultrasound beams 15 - 16 are emitted by transurethral scanner 47 and transrectal scanner 14 respectively. A tumor 46 is shown in the beam path and being scanned from both sides. FIG. 2 also shows a biopsy needle 45 deployed through gimbal 83 into said tumor.
[0062] [0062]FIGS. 3A, 3B, and 3 C are cross-sectional schematics showing the beam patterns 16 , 15 emanating from each ultrasound scanner (transrectal 14 and transurethral 47 ) separately and then in the actual overlapping pattern. Each pattern is superimposed on an outline of a diseased prostate 41 showing the bi-directional scanning of a tumor section 46 lying in the scan plane.
[0063] [0063]FIGS. 4A, 4B and 4 C are schematics showing a top view, a side view and a cross-sectional view of the patient chair 1 together with its associated mechanisms. FIG. 4A shows the chair 1 pivoting around pivot 17 which is in turn mounted on support platform 11 . FIG. 4B shows the lateral movement 23 for adjusting the patient position relative to center line. FIG. 4C shows the elevation mechanism 24 and the tilting action of the chair 1 proper.
[0064] [0064]FIGS. 5A, 5B and 5 C show the same three views of the chair but define the locations of the multiple actuators 26 a, b, c, d, e in the chair back, 27 a, b, c in the belt, 28 and 29 a, b in the hip fences, and 22 a, b which produce the excitation sound waves used for the dynamic elastography feature.
[0065] [0065]FIG. 6 shows the impingement of elastography pressure waves arriving at an area of differential stiffness, so that by varying the direction, frequency, and power of the impinging waves, it is possible to maximize the ultrasonically detectable differential vibration of the tumor.
[0066] [0066]FIGS. 7A, 7B and 7 C show the same three views of the chair as in FIGS. 5 A-C but define the locations of the field generating elements 35 a, b for the magnetic position sensing system used in conjunction with the floating transrectal probe 38 which will be shown in FIG. 8.
[0067] [0067]FIG. 8 is a sectional, schematic, anatomical view showing the above mentioned floating transrectal probe 38 in situ. The drawing shows the relationship of the magnetic field 36 produced by above said generating elements to the sensing coils 40 a, b located at either end of said floating probe 38 .
[0068] [0068]FIG. 9 is a sectional, schematic, anatomical view showing said floating transrectal probe 38 in situ within the rectum 43 . The drawing particularly references the location of the two magnetic sensing coils 40 a, b relative to the probe body and the attachment of said probe body to the umbilical 33 .
[0069] [0069]FIG. 10 is a sectional, schematic, anatomical view showing both the transrectal probe tip 18 and the transurethral probe 47 in situ with a special diagnostic needle 45 deployed into a detected tumor 46 . Said diagnostic needle as shown in the enlarged inset carries a pair of detection coils 48 a, b that measure the effective radio-frequency bio-impedance of the tumor. Said bioimpedance has been shown to vary with the stage of the tumor.
[0070] [0070]FIG. 11 is a sectional, schematic, anatomical view showing the transurethral catheter 52 and catheter feeder 53 in situ. The drawing shows the fiber optic viewer/guide 56 in situ within the catheter 13 and protruding into the urinary bladder 42 . The upper end of the fiber optic terminates in a small video camera 55 which feeds a display used by the doctor for guidance and to assist in diagnosis. The water feed line 54 is shown attached to the catheter feeder 53 , via luer fitting 57 .
[0071] [0071]FIG. 12 is a sectional, schematic, anatomical view showing the same view as in FIG. 11, but with the fiber optic viewer/guide withdrawn from the catheter/catheter feeder assembly.
[0072] [0072]FIG. 13 is a sectional, schematic, anatomical view showing the same view as in FIG. 12, but with the transurethral ultrasound probe 47 inserted through the catheter into the catheter 52 as far as the correct starting position at the distal end of the catheter just within the upper sphincter of the prostatatic urethra 53 .
[0073] [0073]FIG. 14 is a sectional, schematic, anatomical view showing a close-up cross section of the catheter 13 within the urethra 62 . The distal opening of the catheter 69 is shown with the fiber optic viewer/guide 56 protruding through said distal opening 69 . The water filling the catheter 64 and being extruded through said distal opening to form a leading bolus 61 is shown.
[0074] [0074]FIG. 15 is a sectional, schematic view showing the details of the catheter 13 /catheter feeder 53 assembly. Shown are the passageways, the luer fitting for the water inlet 72 , the sealing O-ring 71 which minimizes water leakage around inserted probes, and the push-in latch 73 used to attach the catheter feeder to the receptacle at the distal end of the transurethral locating arm.
[0075] [0075]FIGS. 16A and 16B are sectional, schematic views showing a front pseudo-perspective and a side cross sectional view of the transrectal probe 18 general layout. In said front pseudo-perspective view (FIG. 16A) the two complimentary scanning ultrasound systems 14 a,b are shown, resident in the forward (towards the prostate) looking cavity/window 19 on the ventral side of the transrectal probe. Said front pseudo-perspective view also shows the slot aperture 84 which is one element of the dynamic elastography multi angle excitation system. Cavity 19 is a cutaway of the front of the rigid probe tip support structure 80 which is shaped to conform to the covering condom 81 . The condom covers the entire surface of the probe tip 18 and probe body 44 . Housed within the thickened back wall of the condom are lumens to accommodate a fiber optic viewer, a water fill line and an air bleed line, all of which terminate in openings in the end cap of the condom (detailed in FIG. 21). The condom forms the front wall of the cavity 19 which houses the dual ultrasound scanners 14 a, b to act as an acoustically transparent window.
[0076] [0076]FIGS. 17 and 18 are sectional, schematic views showing the relationship of the dual beams 101 a, b emitted by the dual ultrasound scanners 14 a, b in said transrectal ultrasound probe. As the beams sweep across a tumor 46 they cause different angles of acoustic shadow 102 as shown.
[0077] [0077]FIGS. 19, 20, and 21 are sectional, schematic views showing three cross sections through said transrectal probe. FIG. 19 shows the custom silicon condum 81 which has a thickened back wall housing three lumens. The central lumen 88 is a passageway for a fiber optic viewer permitting visual inspection of the rectum during insertion of the transrectal probe. On either side of said lumen are two other lumens, one for filling the rectum with water 89 to act as a carrier for the ultrasound and one to act as an air bleed 90 for any entrapped air in the rectum. FIG. 20 shows the backbone 80 of the transrectal probe, flattened on the back to conform to the inside shape of said condum 81 . The front is cutaway to form the cavity 19 housing the dual ultrasound scanners 14 a, b. Between the ultrasound scanners is shown a cross section of the generator 91 for the dynamic elastography exciter. FIG. 21 shows the condum 81 in place surrounding and conforming to the backbone 80 . The front of the condom 81 forms the outside wall of the cavity 19 housing the dual ultrasound scanners 14 a, b.
[0078] [0078]FIG. 22 is a sectional, schematic view showing a side view of the condum 81 covering the entire body 44 of the transrectal probe. The aforementioned lumens continue down the back face of the body and are terminated in appended tubes 95 a, b for inputting water, bleeding air and for the intromission of the fiber optic viewer 91 , which passes into lumen 88 through a seal 98 terminated to a video camera 94 .
[0079] [0079]FIG. 23 is a sectional, schematic view illustrating that the transrectal probe body 44 at the junction with the probe tip 18 is flexible in the region of the curved neck in the sagittal plane.
[0080] [0080]FIG. 24 is a sectional, schematic, anatomical view showing the transrectal probe tip 18 in situ within the rectum 43 . The drawing illustrates that the slaved biopsy needle 104 penetrates the condum 81 when it is deployed into tumor 46 within prostate 41 .
[0081] [0081]FIGS. 25A and 25B are sectional, schematic views showing the method by which the transrectal probe body 44 is removably attached to the slaved biopsy needle mechanism housing. The non-symmetrical nesting inner 110 and outer cone 113 docking design guides the transrectal probe body 44 to the proper position and alignment on said slaved biopsy needle mechanism support structure 109 , and the magnetic latch 111 - 112 holds it in place. These views show the elements before engagement.
[0082] [0082]FIG. 26 a is a sectional, schematic view showing the same elements as in FIGS. 25A and 25B after engagement is complete, with cones 110 nested into cone 113 bringing gimbal 83 into the proper position inside the probe tip 18 .
[0083] [0083]FIG. 27 is a sectional, schematic view showing the slaved biopsy mechanism within the housing. The drawing illustrates the relationship of the moving parts of said mechanism at the nominal rest position. 120 is the support structure, 121 is the rotary movement, 122 is the angular movement, 123 is the depth of penetration movement. 124 is the needle drive, 125 is the needle guide tube, which is suspended from gimbal 83 , which is mounted to the tip of inner cone 110 . The entire mechanism is housed within cover 126 .
[0084] [0084]FIG. 28 is a sectional, schematic view showing the same elements as in FIG. 27, with the angular mechanism 122 at the extreme of its travel.
[0085] [0085]FIG. 29 is a sectional, schematic showing the same mechanism as in FIGS. 27 and 28 as it is carried within an angularly adjustable cone support structure 109 to facilitate optimal engagement with the patient regardless of anatomical variation.
[0086] [0086]FIGS. 30, 31, 32 and 33 are sectional, schematic, anatomical views showing a sequence of the operation of a special tool which is deployed into a detected tumor. FIG. 30 shows a macerating needle and flail 130 / 131 deployed within tumor 46 . FIG. 31 shows the tool reducing the volume containing the tumor to a liquid state. FIG. 32 shows the liquid extracted through the macerating needle 130 after removal of the macerating flail 131 leaving a cavity 132 where the tumor was. FIG. 33 shows the cavity filled with a collagen gel 133 derived from the patients own tissues and carrying the appropriate dosage of anti-cancer drugs.
[0087] [0087]FIGS. 34, 35, 36 and 37 are sectional, schematic, anatomical views showing a similar set of sequential views. The drawing differs only in that instead of filling the cavity, a vacuum working through needle 130 , after removal of the flail, is used to collapse the cavity as shown at 135 . A tissue adhesive is then used to seal the opening.
[0088] [0088]FIG. 38 shows the cutting element of the end harvesting biopsy needle. The cutting element consists of two thin square ended cutting blades permanently attached to opposite faces of a square slider element which is in turn mounted the end of a flexible push rod. Said push rod can be activated by any of a number of spring loaded, pneumatic, or electro-magnetic mechanisms, which can be manually or automatically controlled. The slider element and the pushrod have a central lumen to relieve gas pressure from gas that could be trapped inside the needle when it is being forced into the tissue during the harvesting phase.
[0089] [0089]FIGS. 39, 40, and 41 show three cutaway views of the needle from the side. In FIG. 39 the cutting element is fully retracted leaving the mouth of the needle open. FIG. 40 shows the cutting element being advanced, with the cutting blades beginning to follow the curvature of the spear point side plate guides. FIG. 41 shows the blades advanced until they meet at the tip of the needle, separating and enclosing the harvested tissue for extraction.
[0090] [0090]FIGS. 42 and 43 are a set of drawings showing the square cross section of the needle and the configuration and fit of the guides with the cutting blades. FIG. 42 shows the cutting blades fully extended to cut off and enclose a tissue sample. FIG. 43 shows the open end of the needle during the harvesting phase of the biopsy.
[0091] [0091]FIGS. 44A, 44B, 44 C, and 44 D are a set of drawings showing the square cross section of the needle and the fit of the cutting blades within the side plate guides.
[0092] [0092]FIG. 45 shows an alternative curved needle with the same cutting mechanism for situations where such a shape would be desirable. Because the push rod is flexible, the degree of curvature is arbitrary and is tailored to the need.
[0093] [0093]FIG. 46 is a sectional, schematic view showing a patient in position on the integrated support platform. The drawing illustrates the use of a laser cross hair generator 161 to assist the doctor in positioning the patient's anus at the proper point in space for correct alignment of all of the complimentary system elements.
[0094] A detailed description of the making and using of the instant system follows. The patient is reclined on a powered, adjustable chair at an angle between 0 and 20 degrees up from the horizontal, depending on the anatomical requirements of the individual for the comfortable placement of the dual diagnostic probes. This adjustment is under the full control of the doctor. The chair itself rotates and lowers for ease of patient entry. After the patient is seated the chair elevates and rotates to align the patient on centerline and reclines to the angle selected by the doctor. A laser cross hair provides a reference point in 3D space for the optimal initial positioning of the patient. The final positioning of the patient is recorded in the data file for the procedure, so that any subsequent examination can be returned to the same alignment to ensure repeatability. Additional functional elements mounted to the chair include, but are not necessarily limited to: sub-elements of the magnetic position sensor used to track and record the absolute position of the transrectal probe. The ventral set of driver elements for the dynamic elastography analysis augmentation sub-system. Various baseline physiological monitors are incorporated into the chair cushions to simplify the monitoring of patient status.
[0095] The dual diagnostic probes are the transurethral and the transrectal. The description and usage is as follows: Interaction with the doctors has lead to a definition of the relationship and procedures for the use of said probes. The transurethral subsystem consists of several elements. The ultrasound sensor drive system, which has a linear drive, a rotational drive and a signal/power/mechanical connector, is mounted on a movable structure above the area of the patient's groin. This facilitates the introduction of the transurethral probe with the penis in essentially a vertical position, as is commonly done for the introduction of other types of catheters. The drive system can be slidably moved in the vertical plane for adjustment to anatomical patient variability. It can also be slidably moved away from the patient for working clearance during other parts of the procedure. Towards the distal tip of the transurethral drive vertical movement is the signal/power/mechanical connector for the ultrasound diagnostic probe. At the distal tip of the vertical movement is the receptacle into which is inserted the catheter feeder which forms the upper end of the transurethral catheter. This serves the twofold purpose of maintaining the proper relationship between the top of the catheter and the transurethral drive for connecting the ultrasound diagnostic probe, and it also serves to hold the relationship between the catheter and the patient after the catheter/fiberscope combination has been inserted into the correct position within the patient's prostate. The transurethral catheter is 12-14 French in diameter and of a length to suit the individual patient. The catheter is inserted by the doctor through the penis, the prostate and into the bladder using a coaxially contained, articulated fiber optic scope as a guide. At the beginning of the procedure, said articulated fiber optic is threaded through the length of the catheter, such that the articulated portion protrudes through a small opening in the distal end of the catheter. A flow of water is introduced into the lumen of the catheter via the catheter feeder device to which the proximal end of the catheter is attached. The catheter and catheter feeder are permanently connected and supplied as a single unit. The catheter feeder performs a number of functions. The catheter feeder consists of a plastic block with a passageway from top to bottom. In a recessed gallery at the top of the passageway there is a soft, silicone rubber O-ring through which the fiber optic and diagnostic probes are inserted so that they go through the passageway and into the catheter. The O-ring forms a seal to insure that the water, which is introduced into the passageway via a side port, flows down through the passageway and into the catheter that is attached to the bottom of the catheter feeder by a spigot fitting. The water flows around the fiber optic and out through the tip opening around the shaft of the fiber optic. This forms a bolus of water ahead of the catheter as it is advanced through the urethra. The bolus serves both to open the urethra for the passage of the fiber optic guide and the catheter and to lubricate the interior of the urethra. Said water flow also may carry a topical anesthetic to reduce any patient discomfort during the procedure. Said water is introduced under a low pressure via the leuer fitting mounted on the side port of the catheter feeder. The distal end of the catheter may have additional openings to ensure a completely wetted outer surface. The physician uses a viewing screen to guide the fiber optic, via the articulation, through the urethra, into the bladder, The interior of the urethra, the prostate and the bladder can be viewed in this manner, which at the same time the fiber optic shaft acts as a coaxial guide wire for the catheter. After optical examination of the bladder, the fiber optic is withdrawn to a point just within the upper sphincter of the prostate. The distal tip of the catheter is now advanced to be coincident with the fiber optic tip, thus placing it in the correct relationship to the prostate for the diagnostic scan procedure. The vertical movement of the ultrasound drive mechanism is now unlatched and manually moved down to a point immediately adjacent to the catheter feeder block, where it is reached into immobility. Said catheter feeder block is fitted with a rearward projecting latching mechanism, which is now inserted into the distal receptacle, thus holding the correct relationship between the patient and the transurethral ultrasound drive mechanism for the remainder of the procedure. At this time the fiber optic is withdrawn completely from the lumen of the catheter through the catheter feeder. Water continues to flow into the lumen of the catheter as the fiber optic is withdrawn, via the side port of the catheter feeder. This leaves the lumen filled with water for the insertion of the ultrasonic diagnostic probe.
[0096] The Physician now inserts the ultrasound (or other desired modality) examination probe through the upper port of the catheter feeder. The distal end of the examination probe is advanced until it reaches the distal end of the catheter which is already in place. The tip opening that allowed the passage of the fiber optic is smaller than the diagnostic probe, so that the end of the catheter stops the forward movement of the diagnostic probe at the right place. The water eases the movement of the examination probe and the amount that is forced out of the tip opening will fill the prostatic urethra so that an inserted ultrasonic examination transducer assembly can operate in a water bath that fills the lumen of organ. The intent is to give optimal ultrasonic transmission into the volume of the prostate.
[0097] A second diagnostic probe is introduced transrectally. Said probe is flexibly mounted to better accommodate minor anatomical variations between patients. Said probe contains passageways within the probe cover to flood the rectum with water, again for optimal ultrasonic transmission. A second passageway serves to bleed off any displaced air as the rectum is filled with water. Said probe also contains a second optical system which is resident within a third passageway in the probe cover, giving a wide field of view in front of the distal end of the probe. The interior of the rectum can thus be examined for abnormalities during the insertion period of residence and removal of the probe from the body.
[0098] A preferred embodiment of the transrectal probe is described as follows: instead of a single oscillating ultrasonic transducer head which steps vertically though the rectum, the transrectal probe is mechanically modified to accommodate two scanning head assemblies. The two assemblies are identical in size and structure, and are mounted such that they view the area of the prostate in parallel with some separation between them. Mechanically these two assemblies are linked in such a manner that they step along the longitudinal axis together. Further, the driving electronics can pulse and/or receive from each assembly simultaneously or in sequence, providing a further means for shadow analysis in the overall diagnostic capabilities. Such an arrangement can accommodate phased arrays or each assembly can operate at different frequencies to increase the potential capability of the system.
[0099] A second alternative embodiment of the transrectal probe is optimized for patient comfort in cases where there is not an expectation of a requirement for a biopsy. In these circumstances a self-contained transrectal probe does not require the enlarged neck of the biopsy probe, therefore only a small cable passes through the anus for the dual purposes of extracting the data gathering probe and for carrying the electrical and data signals to and from the control apparatus. Functionally, said probe serves the same diagnostic purpose as the previously described transrectal probe. It differs only in that the location and angle of the probe is determined and recorded by a magnetic positioning system. Said free floating system has the virtues of a) minimal distention of the anus during the examination (the primary source of discomfort to the patient associated with the transrectal examination.) and b) essentially infinite flexibility to accommodate itself to variations in the rectal anatomy and angle between patients. At the same time it provides recorded information on the exact positioning of the probe within the rectum, such that should the patient require a rescan, and/or a biopsy at a later time, the second probe insertion can be to the same spatial coordinates and angle as the first for repeatability.
[0100] The two ultrasound scanners (transrectal and transurethral) move axially through the volume of space containing the prostate in sequential steps numbered from the point of origin at one end of the mechanical movements to the hard stop at the other end of the movement. Each step corresponds to a scan slice. The ultrasonic data is acquired as a series of tomographic type slices, each of which is approximately 1-2 mm thick.
[0101] The software assembles the acquired slice data into a 3-dimensional image stack for volumetric analysis and then presentation to the doctor as a level of suspicion map of the patient's prostate. The location in space of any suspect area is determined by the computer and displayed to the physician. The numbered slice in which it occurs defines the axial location of each detected structure.
[0102] In order to improve speed of actuation, mechanical robustness, safety and patient comfort, the biopsy needle uses an offset biopsy system which computes triangles for the vertical axis as well as for the location within the slice.
[0103] Said offset mechanism permits the use of mechanical movements similar to those used in high precision machine tools for aiming control. Said offset mechanism also permits the use of a pneumatically driven biopsy needle activation system which will fire the biopsy needle exactly to the physician designated point, take the biopsy sample and then extract the needle very rapidly for minimum patient trauma. A side benefit to the high speed of the pneumatic system is that the inertia of the tissue into which it is being fired will tend to lessen the possibility of the needle penetration of the prostate displacing the organ, which can push the target area out of alignment.
[0104] Said offset mechanism also permits the easy removal and replacement of the biopsy needle and the contained sample. An improved biopsy needle has been designed to further enhance the capability of the system. Conventional biopsy needles use a beveled tip and take the tissue sample by shearing the tissue on the long axis of the sample. Both of these design features have undesirable side effects. The beveled tip can cause the needle to deflect to the side (“plane”) as it passes through the tissue, particularly if the path of the needle happens to intersect a denser tissue area at an angle. An additional deficiency of current biopsy needles is that the longitudinal shearing action of their sample gathering mechanism can produce more tissue distortion than the pathologists would like to see, thereby making diagnosis more difficult. If the tissue is too dense the current design will sometimes not retrieve a tissue sample. The improved needle design has a square section, bilaterally symmetrical “javelin” point, which has little or no tendency to deviate from the desired path. It is an end harvesting design that cuts and encloses the tissue sample via to opposing cutting blades that “nip” off the tissue sample. Such an arrangement produces less distortion of the tissue for more accurate examination and analysis by the pathologist.
[0105] As a safety feature, when the physician has selected the biopsy site, the computer will set the X and Y needle guide movements to the correct position and then will set the Z movement to control the depth of penetration. The boundaries of the prostate are shown on screen along with the slice number and computed location of the point to be biopsied.
[0106] For further safety consideration an independent sensor mounted on each axis of the movement verifies the actual position that the mechanical movements have taken in response to the computer command. That position will be displayed on screen and should agree with the computed slice number. The physician makes that comparison and if satisfied with the concordance he activates the “Biopsy Armed” control. Only when this step has been accomplished does the computer give access to the “Activate Biopsy Needle” command box. This functionality is not disclosed by any other biopsy system.
[0107] An alternative method of determining if a detected, suspicious area is in fact malignant is disclosed herein. A miniature coil, mounted on the transurethral probe is used to impose a pulsating field on the volume of the prostate. This field is detected by a complimentary coil mounted on a specially modified biopsy needle. The sensitivity of the sensing coil is modulated by the bioimpedance of the tissue immediately surrounding the tip of said biopsy needle, i.e. the area of suspicion into which it has been directed. Studies have shown that the bioimpedance of a malignant cancer differs markedly from that of a benign tumor, or from normal tissue. This data can be used to corroborate, or to give a quick indication of the threat posed by that area of suspicion. This technique appears to offer advantages over the laser florescent technique that has been reported in the literature, since it works over a volume of tissue and does not require the direct exposure necessary for laser florescence. An alternative embodiment would use two coils mounted directly on the biopsy needle. Such an arrangement would give a more localized reading. The physician interacts with the computer via sealed, sterilizable touch controls. He or she uses a touch pad to select the target of interest for biopsy by sliding the intersection of a set of full screen cross hairs to the center of the desired area and touching the select button.
[0108] Most of the controls take the form of a series of nested menus of on screen dialog boxes. The control menus are hierarchical with only a small number of context sensitive controls on screen at any one time. There is a full time, context sensitive help window that defines the functionality of whatever control is currently selected. For activities where it is appropriate for safety reasons, the help window will be supplemented with a prerequisite check list, each element of which must be checked off by the physician before the next one is displayed. All check list elements must be cleared before the command functionality is enabled.
[0109] A special chair is incorporated for maximum flexibility and accuracy in the positioning of the patient for these and other urological procedures. The chair is designed for ease of patient entry and exit. It quickly adapts to the size of the individual patient for comfort, and has multiple degrees of freedom for positioning of the patient. The system incorporates a laser cross-hair alignment system to assist the physician in moving the patient so that the patient's anus is in the optimal position for insertion of the transrectal sensor probe.
[0110] The transrectal system uses dual side scanning ultrasound probes. The upper portion of the probe comprises the scanning transducer capsule and is less than 1 inch in diameter and less than 4 inches long, having a conical, rounded tip. In use the exterior surface is completely covered by a disposable cover. The cover is made from a material which has prior FDA approval. The scanning transducer capsule houses the scanning transducer systems which move longitudinally through the capsule in parallel. The transducer heads move along the longitudinal axis in a series of steps of about 2 mm. Each step corresponds to a sequentially numbered data slice taken transversely through the prostate. At each step both transducer heads would scan through the volume containing the prostate. The result is a series of broad, thin, scans into the prostate which overlap the complimentary scans being performed by the coordinated second system operating within the urethra. The overall effect is that of electronically dissecting the prostate into a large number of thin slices. Those slices are then integrated and analyzed by the expert system software and a level of suspicion map is presented to the doctor. Additionally, if desired, those slices can then be examined and manipulated by the physician in the virtual space provided by the computer. A second alternative transrectal sensor arrangement is to separate the transmitting and receiving functions to different types of transducers for the purpose of optimizing their respective functions.
[0111] The transrectal scanning transducer biopsy capsule is mounted on a hinge joint so that it has a fore-aft movement range in the sagittal plane to accommodate patient anatomic variability. A magnetic locating system is provided to give the precise location and relationship of the transurethral and transrectal probes, for data correlation.
[0112] Below the base of the sensor capsule, the remainder of the transrectal probe consists of a curved neck, which passes through the anus. The sensor capsule is mounted to the top of a handpiece, which is held by the physician if manual insertion is desired. The handpiece terminates at the top in a rounded bulge which serves as a stop to prevent it from being inserted too far into the rectum. The lower end of the handpiece couples, and is latched to the top of the canister that houses the slaved biopsy mechanism. The outer surface of the neck is covered by a continuation of the covering of the sensor capsule that acts as a seal to retain the water that has been injected into the rectum to provide an optimum ultrasonic environment, as well as accommodating the flex of the nodding movement.
[0113] The neck of the transrectal probe removably encloses the gimbal needle exit that is the pivot point for the aforementioned offset biopsy mechanism. The offset biopsy mechanism consists of the following parts:
[0114] The spherical gimbal for the biopsy mechanism is mounted in a socket at the top of a hollow, cone shaped support structure. The exit of the needle guide tube passes through the center of the spherical gimbal. The needle tube hangs from the gimbal down through the cone, which gives it complete freedom to be moved to any angle within the boundary of the cone. The upper end of the tube is flush with the surface of the sphere, while the lower end protrudes downwards and functions as a coupler between the gimbal and the remainder of the slaved biopsy mechanism.
[0115] Said gimbal is mounted at the tip of a supporting cone that is permanently mounted to the top of the canister that houses the X, Y, Z biopsy needle positioning mechanism and the biopsy activation mechanism.
[0116] When the transrectal probe handpiece is placed on the top of the said canister, said gimbal and cone pass into and are seated into a close fitting conical socket internal to the transrectal probe handpiece.
[0117] When the transrectal probe handpiece is seated onto said support cone, it locks into place. When the locking action takes place, the gimbal cone fills the internal socket of the transrectal handpiece and fixes the geometric relationship between the slaved biopsy exit point and the transrectal sensor movement thus providing known coordinate inputs for the system software. Just below and adjacent to the point at which the needle will exit through the probe cover, said cover is provided with an inflatable ridge which serves to push any adjacent anal tissue down and away from the space through which the biopsy needle will be fired. Outside of the cone socket, the wall of the cover neck houses a number of lumens which lie along the slope of the outer cone, and through which pass the various mechanical elements which actuate the movement of the scanner. Ducts that provide for removal of any gas present in the rectum and the introduction of the ultrasonic water medium, and the deployment of a fiber optic system for the examination of the interior of the rectum are provided in the thickened back wall of the disposable probe cover. Since the feed tubes for water are extensions of the disposable cover; they are also disposable for the sake of cleanliness between patients. The concept of incorporating passageways into a modified condom-type cover for the probe rather than having them internal isolates the interior of the diagnostic probe and greatly simplifies the process of cleaning and sterilization.
[0118] As an enhancement to the overall system in order to increase the sensitivity of the mapping, analysis and detection systems, the capability of performing an acoustic/ultrasonic technique called Dynamic Elastography is added as a sub-system to the set of available diagnostic techniques available in the present system. This embodiment differs from previous examples of the technique in that it uses a far more sophisticated method of excitation. Other implementations of the technique have used: focused ultrasound shear waves, mechanical cam type tissue displacement, or acoustic voice coil type exciters. All of the above use uniaxial presentation and a limited frequency and power capability.
[0119] In the present invention, the intent is to provide higher coercive force, a broader excitation spectrum, and the capability for the selection of different angles of excitation presentation. The result is to provide a high available power, tunable excitation, where the angle of presentation to the prostate can be varied to excite different stiffness modes within the prostate, thereby enhancing the positive effects of dynamic elastography on the data acquisition from, and analysis of, any existing pathology within the prostate. The excitation elements are based on piezo-electric material. Piezo-electric materials produce a higher coercive force than other types of acoustic generators and are therefore, perfectly suited and give more capability than any previous technique for dynamic elastography. One set of transducers are applied externally to the lower abdomen. The transducers are housed in an adjustable belt like arrangement. A second set of transducers are mounted on slidably “hip fences” which are adjusted to snugly fit against the patient's hips, which are incorporated into the specially designed chair of the present system. A third set of transducers are below the patient's lower back. A fourth set of transducers are embedded in the surface of the transrectal probe, above and below the window through which the diagnostic ultrasound scans the prostate interior. By using combinations of these transducer groups, excitation waves can be produced in the prostate from many different directions. This means that any available mode of vibration within the prostate can be excited, with positive impact on the identification, location, and diagnosis of any pathologic conditions existing within the prostate. These transducers impose a modulated, frequency swept, sound wave to the abdomen, which causes a vibration of the internal structures, including the prostate. Because vibration interacts most strongly with the visco-elastic properties of various tissues, this technique will cause areas of different “stiffness” to vibrate differentially. The movement pattern is then detected by pulse-echo doppler ultrasound interrogation contained in the present system. This technique has the potential to enhance and make visible prostate cancers that would not normally be detectable owing to small size or lack of distinguishing characteristics in normal grey-scale imaging. A further enhancement to the system is the inclusion of the ability to do doppler blood flow measurements over time (4-D).
[0120] Because of the coherent archiving of the patient data all measurements and scans can be accurately repeated at time intervals, and automatic digital correlation is used to produce a time-variation history for each detected condition which tracks, and quantifies the progression of the condition, a further aspect of the expert system.
[0121] A further enhancement to the present slaved biopsy sub-system is the inclusion of a treatment system which is appropriate for intervention in the case of small, detected and confirmed cancers. A special biopsy needle is available which can be fired into the detected cancer and will stop in place within the cancer. The embedded tip of the needle contains a heating element that can elevate the temperature of the surrounding tissue to above the 43 degree C. temperature, which will kill the cancer cells. Because the necrotized tissue produces a different ultrasonic return than living tissue, the area of killed tissue can be monitored real time to verify that the volume of killed tissue is larger than the previously mapped volume of the detected cancer. Archiving of this data would also permit tracking the condition over time to verify that all of the cancer was indeed killed.
[0122] A further enhancement of the present slaved biopsy sub-system is to provide the ability to inject high potency, anti-cancer drugs embedded in a viscous carrier, directly into a detected tumor if it is too large to use the hyperthermic technique described above. A further enhancement of the present system is to provide an endo-surgical system to deal with large detected cancers. The system uses a special needle to homogenize the tissue within the tumor and then aspirate the resulting debris. Once the cancer has been destroyed, the total removal of the malignant tissue is verified by the laser florescence technique (or by the use of the described bioimpedance system from within the created cavity, or alternatively by overlaying the ultrasonically mapped image of the cavity onto the stored image of the detected tumor mass.) Depending on the size of the created cavity, said cavity can be closed by creating a vacuum within the cavity to collapse it and then injecting a tissue adhesive to seal the cavity. Cavities that are too large for this technique are closed by filling them with a collagen gel that has been infused with the appropriate mixture of drugs. In order to absolutely preclude any “foreign body” reactions to the collagen gel, said collagen could be derived from the hair and fingernail clippings of that patient. Such a procedure produces a collagen gel that is completely biocompatible with that patient. | A holistically integrated ultrasonic system for examining, mapping, diagnosing, and treating diseases of the prostate gland in a male human includes an ultrasonic transrectal probe and an ultrasonic transurethral probe. Each of these probes is adapted to pulse and to receive, as well as to produce and operate within a liquid-filled volume of the lumen into which they are inserted. Each probe is in operative communication with an integrated patient support platform and an integrated expert system. The integrated expert system collects data transmitted by sensors in the transrectal and transurethral probes and produces level-of-suspicion mapping of the prostate gland with cancer probability assessments for areas contained within the level-of-suspicion mapping. The integrated expert system communicates with, and provides targeting coordinates for operation of an automated slave biopsy subsystem and directs a biopsy needle to a selected point within the prostate gland. The biopsy needle includes a means for extracting a biopsy tissue sample from the prostate gland. The integrated patient support platform includes a multi-degree of freedom positioning chair which optimizes positioning of a patient for scanning and biopsy procedures and affords repeatability thereof. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 61/891,702, filed on Oct. 16, 2013. The entire disclosure of the above application is incorporated herein by reference.
STATEMENT OF GOVERNMENT RIGHTS
The United States Government has rights in this invention pursuant to Contract No. DE-AC52-07NA27344, between the U.S. Department of Energy and Lawrence Livermore National Security, LLC, for the operation of Lawrence Livermore National Laboratory.
INTRODUCTION
Non-oxide ceramics materials, such as those based on carbides, nitrides, and borides, are used as materials in a variety of applications. Non-limiting examples include armor, transparent ceramics for lasers, electronic devices and switches, cutting tools, radiation detector components, catalysts, insulation, high strength materials, high temperature materials, and the like. Current processing of carbides, nitrides, and borides or mixtures of these materials proceeds by forming the desired compound in a high temperature reaction process. The resulting products are then ground to a desired particle size for consolidation as powder into a component.
The known process is relatively expensive and limits how fine a powder can be prepared. As a result, the process limits how good a dispersion can be achieved and/or results in a contamination of powder. In a typical grind, the powders produced are on the order of a 1000 nanometers at least and contain contamination from the mixing apparatus, such as when ground by steel balls. In addition, the grinding process provides for poor mixing of powders.
After the powders are formed in this way, they are consolidated into a component using standard commercial means, such as sintering, hot pressing, hot isostatic pressing (HIP), hot or cold extrusion, spark plasma sintering (SPS), and the like. The strength and other characteristics of the consolidated material depends in many ways on the quality of the powder, including its grain size and quality of mixing. Improved methods of making non-oxide products such as WC, TiC, SiC, and B 4 C would represent a significant advance.
SUMMARY
A general procedure has been developed that can be applied to a variety of sol-gel precursors and solvent systems. Sol-gel processing eliminates some disadvantages of prior methods by using pure chemicals to form a mixture of oxides and organic binders that are subsequently reacted at low temperatures in controlled environments to form very fine particles of the desired powder or porous ceramic bodies.
Sol-gel processing of pure chemicals according to the disclosure is used to form blends of oxides and organics that are then reaction heat treated in controlled environments to form metals, oxides, carbides, nitrides, or borides of fine powders, blends of powders, and/or porous components. Fine particles can also be added during the sol-gel process to improve dispersion of such particles.
Advantageously, sol-gel processing of pure chemicals is an inexpensive method of producing very fine oxides, such as WO 3 , TiO 2 , SiO 2 , and B 2 O 3 and the like. Forming these fine oxides within a web of organic material allows subsequent controlled reactions between the oxides, the organic materials, and the controlled environments. The reactions disclosed here convert these oxides to other desired powders and components of greater commercial value like the corresponding carbides, nitrides, and borides.
A method according to the disclosure involves the steps of forming an intimate mixture of an inorganic oxide and organic polymer, followed by reaction heat treating the mixture to form particles of a non-oxide ceramic. Thereafter, the particles are consolidated into a solid ceramic object. Advantageously, the solid ceramic object is characterized by a domain size of 100 nanometers or less.
The intimate mixture is one formed using a sol-gel process. In an embodiment, a first sol and a second sol are formed in a solution, wherein the first sol is an inorganic gel intermediate (i.e., an intermediate in the formation of an inorganic gel via the sol-gel process) and the second sol is, in similar fashion, an organic gel intermediate. Reaction in the solution continues under sol-gel conditions until at least one of the first sol and the second sol forms a gel comprising the respective inorganic oxide or organic polymer. The result in some embodiments is a interpenetrating network of inorganic oxide and organic polymer. The solvent is then removed from the solution to form the intimate mixture. As a result of the sol gel processing, the domain size of resulting particles is defined by the pore size of the intimate mixture or the interpenetrating network. Advantageously, the domains are characterized by dimensions of 100 nanometers or less, such as 50 nanometers or less, and 20 nanometers or less.
DESCRIPTION
According to various embodiments of the disclosure, sol-gel processing is used to create interpenetrating networks of two sol-gel chemistries. In sol gel processing, one begins with a solution of starting monomers (precursors) in a solvent such as water at low viscosity. Upon reaction for an initial time, the monomer precursors form a colloidal dispersion of a polymeric material called a sol. Upon reaction for a further time under the right conditions, the sol progresses until a gel is formed in the solution. To illustrate, a commonly gel made by such a process is a silica gel. To make a silica gel, a monomer such as TEOS (tetraethylorthosilicate) is provided with a low pH or added acid and hydrolysis begins. As some of the TEOS monomers polymerize and form extended siloxane networks in the solution, a colloidal suspension or sol is formed. Upon more reaction time, the sol further reacts and crosslinks until the network essentially fills the volume of the solution to form a gel. Although such gels readily form, there is an empirical component to adjusting the conditions so that the desired component forms. If the conditions are such that the reaction is too slow, the gel does not form and one achieves only a viscous fluid. On the other hand, if the kinetics are too fast, the sol forms too fast to remain in suspension and forms a precipitate.
In one aspect of the current disclosure, the sol-gel processing involves forming two sols simultaneously in the presence of one another, wherein at least one of the sols proceeds until a full gel is formed in the solution. An advantage of the method is that the sols and gel material have nanometer-sized pores. Since both gels are essentially being formed simultaneously, the two materials form in the pores of one another. Since the pores are nanosized, the solid remaining when solvent is removed is an intimate mixture based on interpenetration of the pores on the nano-scale. This intimate mixing of the two material leads to advantages of the method as described further herein.
In methods according to the current disclosure, the first sol is an inorganic oxide, and the second sol is made of an organic polymer. Suitable starting materials (precursor monomers) for both the inorganic oxide and organic polymer are described further herein. In one embodiment, a gel of the inorganic oxide forms at the same time a gel of the organic polymer is formed. If both gels form, the structure created is an interpenetrating network having two independent networks of materials. If one gel forms and the second does not fully form, then sol particles of one of the materials are held in the pores of the gel of the other material. One of the materials is fully immobilized (the one that has formed the gel), while the other material tends to migrate partially out of the pores of the other material upon removal of the solvent. In such a situation, subsequent heat treating of the intimate mixture will tend to overcoat the fully gelled material to at least a slight extent. But an intimate mixture of the two materials is still formed upon removal of the solvent. And the material remaining after subsequent reaction heat treatment contains particles with nanometer sized domains that provide useful ceramic articles upon consolidation.
In one embodiment, a method involves forming an intimate mixture of an inorganic oxide and organic polymer, reaction heat treating the mixture to form particles of a non-oxide ceramic, and consolidating the particles into a solid ceramic object. Advantageously, the solid ceramic object is characterized by a domain size of 100 nanometers or less. In various embodiments, the non-oxide ceramic is a carbide, a nitride, or a boride. The organic polymer is one that will form a gel in solution, such as a polymer of aldehyde and a mono-, di-, or a trihydroxy-substituted aromatic ring. Examples of such polymers include phenol formaldehyde resins, polymers of dihydroxybenzene (resorcinol) and formaldehyde, and polymers of trihydroxybenzene (such as phloroglucinol) and formaldehyde.
Forming an intimate mixture involves sol gel processing. In one embodiment, it involves forming a first sol comprising an inorganic gel intermediate in a solution, forming a second sol comprising an organic gel intermediate in the solution, and further reacting in the solution until at least one of the first sol and second sol forms a gel comprising the respective inorganic oxide or organic polymer. The gel is formed when the mixture has set up and has no fluid flow capability. Thereafter, solvent is removed from the solution to form the intimate mixture.
In another embodiment, the intimate mixture is formed by reacting monomer precursors of a first sol in a solution and reacting monomer precursors of a second sol in the solution. As before, the reaction is carried out in the solution for a time sufficient to form a gel from at least one of the first and second sols. Thereafter as before, the solvent is removed from the solution to form the intimate mixture. The first sol comprises an inorganic oxide and the second sol comprises an organic polymer. As noted above, the method involves forming an interpenetrating network of two sol gel chemistries in a solution and then removing the solvent from the solution to form the intimate mixture for further processing.
To make an interpenetrating network, two sol-gel processes are carried out simultaneously. One way of doing this is to react first starting monomers of a first sol in a solution and reacting second starting monomers of a second sol in the same solution. Then the first and second starting monomers are reacted in the solution until at least one of the first sol and the second sol completely reacts to form a gel in the solution. At that point, the solution forms a gel mixture. Thereafter, the solvent is removed from the gel mixture to form a mixture of inorganic oxide and organic polymer. The mixture is then reaction heat treated to form particles of non-oxide ceramic such as carbides, nitrides, and borides.
In this aspect, at least one of the first starting monomers and the second starting monomers react completely to form a gel in the solution. In some embodiments, the other starting monomers also form a gel in the solution, after which the solvent is removed and the mixture subjected to reaction heat treating. In another aspect, only one of the first starting monomers and the second starting monomers proceed to form a gel in the solution, while the other starting monomers form a polymeric material that stops short of forming a gel. In both of these variations, the first starting monomers and the second starting monomers are reacting in the solution at the same time.
In another embodiment, the method involves forming a first gel comprising inorganic oxide in a solution and forming a second gel comprising organic polymer in the solution to form a gel mixture. Thereafter, the solvent is removed from the gel mixture to form a blend of inorganic oxide and organic polymer. The mixture is then reaction heat treated to form particles of non-oxide ceramic such as carbides, nitrides, and borides.
In one variation of the above methods, the starting materials for both gels are combined in the solution at the same time at the beginning of the reaction. Reaction then proceeds to form each gel in the presence of the other gel. In other variations, one of the polymerizations or gel reactions is begun and continued for a time, at which later time either a) the precursor monomers of the other gel material are added, or b) a catalyst or initiator is added to a solution containing the precursor monomers in order to begin the polymerization reaction. In various embodiments, base or acid is used as the catalyst or initiator. Certain of the polymeric gels can be initiated with either acid or base. Systems with such gels are flexible, since they can be used together with either base-initiated or acid-initiated inorganic gels. The precise timing and order of addition of the respective precursor monomers depend on the nature of the monomers, and on the relative kinetics of sol- and gel formation. Examples of reaction conditions are given in the working examples that follow.
Inorganic Oxides
Sols and gels of inorganic oxides are formed using known methods and chemistries.
In various aspects, methods described herein involve forming an intimate mixture of an inorganic oxide and an organic polymer. An inorganic oxide as used herein refers to a solid having an extended network of element/oxygen/element bonds that can be synthesized by employing sol-gel reaction conditions known in the art. Thus, inorganic oxides include those reachable by known sol-gel procedures.
In some embodiments, the inorganic oxides are oxides of a transition metal or an alkaline earth metal, where the element of the element/oxygen/element bonds is traditionally classified as a metal. In such cases, the inorganic oxides can be referred to as metal oxides. Other inorganic oxides according to the disclosure are made from elements that are traditionally classified as metalloids (e.g. Al, Mg, Ga, Ge). Oxides of non-metals such as silica and oxides of boron are also included in the term “inorganic oxide.”
Elements known to form gels of metal oxide from a sol gel process include Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, Zr, Nb, Mo, La, Hf, Ta, and W of the transition metals. Further examples include Ga, Ge, In, Al, Sn, and Sb of the metalloids. Further example includes lanthanides selected from Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and actinides selected from Th and U. Finally, as noted the oxide can be a compound of B or Si.
Inorganic oxides are formed by using a sol-gel process. In a sol-gel process, starting materials are dissolved in a solvent and an initiator or catalyst is added to begin the reaction. The reaction is also controlled by temperature and pH. The starting materials consist of starting monomers or monomer precursors selected according to the conditions and the known chemistry for any individual element. Starting materials include oxides, alkoxides, halides, nitrates, and other suitable compounds of the respective element that makes up the inorganic oxide. Although the terms “starting monomers” and “monomer precursors” are given in the plural, it is to be understood that for many inorganic oxides, only a single precursor reacts to incorporate elements in the extended oxide network. In these cases, other “monomers” or precursors are understood to include catalysts such as acids or bases that are used to initiate the reaction, as well as any other auxiliary components or initiators. The plural also accounts for embodiments where the inorganic oxide is formed from more than one element. To illustrate, reaction is carried out in a suitable solvent such as water or an organic solvent and is typically initiated by adding acid or base to the solution of the monomer precursor(s) in the solvent. Suitable starting materials and conditions for forming gels and extended networks of inorganic oxides are given in the examples.
For convenient reference, the class of materials selected from oxides, nitrides, carbides, borides of these elements are referred to herein as ceramics, oxide ceramics, and non-oxide ceramics, depending upon the context.
Organic Polymers
At the same time that a sol or a gel of the inorganic oxide is being formed, a sol-gel reaction is carried out that can result ultimately in formation of a gel of an organic polymer. Certain polymers are known to form such gels. In a typical reaction, starting monomers (which are also called by the term monomer precursors or equivalent nomenclature) are dissolved in a suitable solvent and the polymerization initiated with catalyst or initiators. One family of suitable polymers is a copolymer of an aldehyde and a monomer containing an activated aromatic ring. Suitable aromatic rings or starting monomer of the polymers include phenol or other aryl rings substituted with 1, 2, or 3 hydroxyl groups. Examples include copolymers of formaldehyde and phenol (so-called phenol formaldehyde resins), copolymers of formaldehyde and dihydroxybenzene (such as resorcinol), and copolymers of formaldehyde and trihydroxybenzene (such as phloroglucinol).
Other polymers can be used as long as their synthesis is amenable to the sol-gel process. This is especially true if the gel of organic polymer is to be the primary gel. Examples include isocyanate polymers (polyurethanes and polyureas, for example) and cellulose polymers.
As noted above, suitable results are observed in systems of the disclosure as long as one of the gels is fully formed and its pores contain particles of the other material. As relevant here, it is possible to use organic polymers that form less than an ideal gel under the sol gel conditions as long as the metal oxide is one that is fully gelled under the conditions.
Reaction Heat Treating
After the gel mixture is formed, the solvent is removed from the gel mixture, leaving the intimate mixture of inorganic oxide and organic polymer. Solvent can be removed by any convenient means such as freeze drying and spray drying. After the solvent is removed, the resulting intimate mixture is subject to reaction heat treating conditions to make carbides, nitrides, borides, or other materials.
Heating the intimate mixture in an inert atmosphere and/or in the presence of hydrogen tends to lead to formation of carbides under the reaction heat treating conditions, with the carbon being supplied by the polymer gel. It has been found that the use of hydrogen in the atmosphere for reaction heat treating makes it easier to remove oxygen from the intimate mixture of materials so that the oxide material is fully converted to the carbide.
To make nitrides, a nitrogen component is included in the atmosphere in which the reaction heat treating is carried out. Suitable nitrogen containing components here include ammonia (NH 3 ) and nitrogen gas (N 2 ). In addition or alternatively, non-reacting nitrogen components can be included in the initial mixture of starting monomers of the respective gel components, where they survive the sol gel reaction and become part of the gel mixture. Upon removal of the solvent, the additional nitrogen components are part of the intimate mixture. Then, upon reaction heat treating the components supply nitrogen for the reaction that takes the metal oxide to a metal nitride. Examples include non-volatile and non-reactive nitrogen salts such as ammonium salts (e.g. ammonium hydroxide), nitrate salts, and the like.
In a similar way, to make borides, boron compounds are included in the reaction heat treating conditions. In one embodiment, a boron compound is added to the intimate mixture before the reaction heat treating. Alternatively or in addition, boron compounds can be provided in the original reaction vessel and become part of the gel mixture, and of the intimate mixture upon solvent removal. Suitable boron compounds include B 2 O 3 , H 3 BO 4 , and salts of boron such as Na 2 B 4 O 7 .
Doping with Non-Oxide Components
The sol-gel reaction mixtures can be doped with other components that survive the sol-gel conditions and are incorporated into a ceramic powder after the reaction heat treating is carried out. An example is adding a metal salt to the initial solution of precursors of the respective sols, so that the metal salt becomes a part of the gel mixture and of the intimate mixture resulting from solvent removal. The metal salt is then subject to heat treating conditions where the salt is reduced to the metal under the influence of carbothermal reduction. In this way, non-oxide ceramic materials can be made that, for example, have finely dispersed metal. An example is the tungsten carbide/cobalt cutting tool material exemplified in one of the examples.
Consolidating Non-Oxide Ceramic Powders
The product of forming the intimate mixture and subjecting the intimate mixture to reaction heat treating conditions is a powdered ceramic material characterized by a domain size less than 100 nanometers, and typically less than 50 nanometers, or less than 20 nanometers. The grain size can be measured by x-ray diffraction means or electron microscope (SEM, TEM, etc.) means.
Such a powder is consolidated into solid materials for known applications by standard commercial means such as sintering, hot pressing, hot isostatic pressing (HIP), hot/cold extrusion, spark plasma sintering (SPS) and the like. It is believed that the small domain sizes achievable by using the methods described herein contribute to the favorable properties of solid ceramic materials so produced.
EXAMPLES
Example 1—Preparation of WC with a Fine Dispersion of Co
Preparation of WC gels containing 8% Co is described here. Materials used are: 1) Tungsten Source: 0.697 M Na 2 WO 4 ; 2) Dowex 50W2X-100; 3) Carbon Source: 1.70 g Phloroglucinol, 1.75 g Formaldehyde 37%, 80.0 g H 2 O, and 0.04 g Ca(OH) 2 ; and 4) Cobalt Source: 0.349 M Co(C 2 H 3 O 2 ) 2 .
Prepared an ion exchange column using 30.6 g Dowex 50W2X-100 resin. Washed with deionized water to remove orange color.
To a 250 ml beaker equipped with a Teflon® stirrer, the carbon source constituents (monomer precursors for the organic polymer) were added and heated gently until a clear yellow green solution was obtained. 10 mL of the solution was combined with 2.5 mL of the cobalt solution with stirring.
Apply the sodium tungstate to the column and collect H 2 WO 4 from ion exchange column at pH 1 as indicated with Hydrion paper. Add 5 ml of this solution to the carbon source plus cobalt with stirring. Let sit to gel overnight. Freeze dry or spray dry gel to remove solvent.
Place the above powder product into a graphite crucible and reaction heat treat the powder at 1000° C. for four hours in flowing mixture of 4% H 2 -argon gas. The resulting powder is a fine blend of tungsten carbide (WC) with cobalt (Co) metal dispersed uniformly throughout the powder blend. This blend is then consolidated by commercial sintering processes into WC—Co cutting tools.
Example 2—Preparation of TiC Gels
Organic polymer precursors are 6.126 g Resorcinol, 9.025 g Formaldehyde 37%, 22 g water, 0.380 g acetic acid (AcOH).
Beaker A: To a beaker equipped with a stir bar, add resorcinol and water to dissolve. Add formaldehyde and AcOH.
Inorganic oxide precursors are 124 g Ti(OC 2 H 5 ) 4 tech grade, 10 g AcOH, 300 g ethanol (EtOH).
Beaker B: To a beaker equipped with a stir bar, add Ti(OC 2 H 5 ) 4 , EtOH and AcOH. Add contents of beaker B to beaker A while stirring. Cover and place in oven at 50° C. for 24 hrs. Remove solvent by heating at an elevated temperature, such as 90° C. under an inert atmosphere, then heat treat at 1100° C. in flowing 4% hydrogen in argon to make TiC.
Example 3—Preparation of B 4 C Gels
1.71 grams phloroglucinol, 1.75 grams formaldehyde 37% aq., 80 grams water, and 1.40 grams B 2 O 3 were heated while stirring on a hot plate. 0.04 grams Ca(OH) 2 was added at 47° C., then removed from heat. Let stand at room temperature to gel to an opaque yellow in 10 minutes. Placed in freezer, then freeze dried to remove solvent. Suitable materials substituting for B 2 O 3 would include the acids of boron such as H 3 BO 4 and the salts of boron such as Na 2 B 4 O 7 .
Suitable materials for substitution of phloroglucinol would include resorcinol or phenol and similar starting materials. The freeze dried materials are slowly (<5 C/min) heated to 1100 C in a protective/reducing atmosphere (4% H 2 -argon) to remove volatile compounds while reducing oxide compounds to carbides. Forming crystalline powder of B 4 C requires even higher heat treatments (>1400° C. for 4 hours) so the final product can be identified by x-ray diffraction means as B 4 C powders.
Example 4—Preparation of SiC Gels
1.24 grams Resorcinol, 10.0 grams EtOH, 1.97 grams Formaldehyde 37% aq., 10 grams tetramethylorthosilicate (TMOS), 1.0 ml NH 4 OH 28%.
To a beaker equipped with a stir bar, add resorcinol and H 2 O to dissolve. Add formaldehyde and TMOS. Add NH 4 OH to initiate sol gel process while stirring. Set up starts within 1 minute becoming opaque within the hour. Place in oven at 50° C. for 24 hrs. Remove solvent. For reaction heat treating, solid material is heat treated slowly (5 C/minute) to 1100 C and held for 4 hours at temperature. Subsequent heat treatments to >1500° C. are generally needed to convert the amorphous SiC into the desired crystal phase (6H or 4H) suitable for electrical switching applications.
Example 5—Preparation of Borides and Nitride Gels
The preparation of borides and/or nitrides is similar to the preparation of the B 4 C above except the amounts of hydrocarbons are reduced so that the inorganic oxide materials (WO 3 , TiO 2 , AlOx, MgOx, etc.) are not reduced and reacted to the carbides. Instead, the oxides react with furnace gases (NH 3 , H 2 , etc.) and/or chemicals in the gel mixture to form a boride (WB x , TiB 2 , AlB x , MgB x , etc.) and/or a nitride (TiN x , AlN x , MgN x , Si x N y , etc.). Depending on the particle size and phase desired, the heat treatment can vary but generally requires conditions to reduce the oxides and transform the solids at >1100° C. in 4 hours. | A general procedure applied to a variety of sol-gel precursors and solvent systems for preparing and controlling homogeneous dispersions of very small particles within each other. Fine homogenous dispersions processed at elevated temperatures and controlled atmospheres make a ceramic powder to be consolidated into a component by standard commercial means: sinter, hot press, hot isostatic pressing (HIP), hot/cold extrusion, spark plasma sinter (SPS), etc. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/479,101, filed Jun. 17, 2003.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to sunshades and more particularly to a freestanding self-erecting shade device that is collapsible for convenient transport and storage.
2. Description of the Related Art
Collapsible sunshades for chairs have been the subjects of previous patents. For example, in US 20003/0106577 A1 published Jun. 12, 2003 to Martinez teaches a collapsible sunshade for a chair. The shade is provided in the form of a flexible ring made of spring steel or other spring material. A fine mesh membrane or fabric material is attached to and disposed within the ring. The ring may be moved between an open position for providing shade and a closed position under spring tension for collapsing the shade. The opened shade can be bent and affixed to a chair to cover at least a portion of the seat of the chair. In one form of the Martinez shade, opposite ends of the erected shade are affixed to the arms of the chair to cover the seat portion of the chair. Another version of the Martinez shade has a narrow rear end and a wide front end. The narrow end is affixed to a support band on the back of the chair by fasteners. Cords are provided on the wide end to cinch to the chair so that the shade is bent towards the front of the chair over the seat of the chair in a position permitting a user to sit in the chair. A small fabric pocket may be attached to the shades for carrying small items and a flap or screen is provided in central portion of the shades to allow wind to pass through.
In FIGS. 23-28 of U.S. Pat. No. 6,698,827 B2 issued Mar. 2, 2004 to Le Gette et al., collapsible shades similar in design to the Martinez shade. Gette et al., however, places the ventilation opening on the narrow rear portion of the shades and includes a carry bag for the collapsed shade. The flaps extend away from the perimeter of the flexible band frame and provided with cord and fasteners for securing the shade to the chair. The flaps also provide additional shading.
In Patent Application Publication Number US 2002/0112752 A1 published Aug. 22, 2002 to Blakney a rigid folding canopy frame is supported in a chair bag mounted over the back of the chair. The chair bag includes a fabric pouch stitched thereon. A set of interchangeable canopies including a sunshade hemmed above the line of sight of a person sitting underneath it, a mosquito net of dark mosquito netting and a photography or changing blind having a hole in the line of sight of a person sitting in the chair.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus a self-erecting and collapsible shade device solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
The self-erecting and collapsible shade device of the present invention is provided in the form of a portable collapsible shade assembly that includes, a self-erecting and collapsible canopy, a self-erecting and collapsible canopy shade pivotally mountable to the erected canopy, at least two ground stakes and anchor lines for securing the canopy against strong winds and a storage bag for conveniently carrying the collapsed canopy, collapsed canopy shade, and other components of the assembly.
The erected shade assembly may be secured directly to the ground or affixed to an outdoor chair or seat having a supported backrest. When the storage bag is empty it can also be used as a seat cover to protect the users clothing from grass stains and soil. The assembly is primarily intended to be used to provide shade out in the open under the sun but may also be used as a hunting blind.
It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an environmental perspective view of the freestanding self-erecting and collapsible shade device according to the present invention.
FIG. 2 is a perspective view of the canopy of the shade device according to the present invention mounted upon a chair.
FIG. 3 is a rear perspective view of the canopy of the shade device according to the present invention mounted upon a chair.
FIG. 4 is a front view of a bag for storing and transporting the canopy shade and canopy of the shade device according to the present invention.
FIG. 5 is a top plan view of the canopy the shade device according to the present invention.
FIG. 6 is a front perspective view of the canopy shade for the canopy of the shade device according to the present invention.
FIG. 7 is a perspective view of the shade device according to the present invention showing a meshed storage bag affixed on the inside of the canopy.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is a portable freestanding self-erecting and collapsible shade assembly 100 . The erected shade assembly 100 may be secured directly to the ground or affixed to an outdoor chair or seat having a supported backrest. Referring first to FIG. 1 , shade assembly 100 includes a storage bag 200 , at least two stakes 104 , anchor lines 105 , a canopy 106 and a canopy shade 111 . The canopy 106 is secured to the ground by anchor lines 105 . One end of each anchor line 105 is connected to the top section 107 of canopy 106 and secured to the ground at a second end by stakes 104 . Storage bag 200 is placed on the ground underneath canopy 106 as a ground cover to be sat upon by a user.
In FIGS. 2 and 3 , canopy 106 is shown affixed to a chair 119 . Canopy shade 111 is shown erected and pivotally attached to the top section 107 of canopy 106 from an open position permitting entry by a user to a closed position providing shade over the front opening of canopy 106 . FIG. 3 additionally shows two rear web straps 112 which are used to secure canopy 106 to the backrest of chair 119 or to secure the canopy 106 to the ground with a stake 104 .
Turning now to FIG. 4 , the flexible body 120 of storage bag 200 is shown to be generally circular in shape having a front side 121 and a back side 122 . A zipper 123 is provided in the opening 124 of bag body 120 . Storage bag 200 is sized to receive the collapsed canopy 106 , the collapsed canopy shade 111 , the tie-stakes 104 and anchor lines 105 . A flexible carry strap 125 is attached to a top edge 126 of bag body 120 and a pocket 127 with closure flap 128 is provided on the front face 121 of the bag body 120 . The bag body 120 may be formed from any suitable durable flexible material. Patches 129 of hook and loop fastener material are provided on pocket 127 for releasably engaging patches 130 on the underside of flap 128 so that additional personal items can be removably stored in pocket 127 of bag body 120 .
FIG. 5 shows that the canopy 106 is provided in the form of a generally oval section 150 and a U-shaped section 151 . Stitching 169 along the side edges 168 secures U-shaped section 151 to a rear edge of oval section 150 to form the rear section 110 of canopy 106 .
Oval section 150 further includes a first frame access openings 164 centrally located along the front edge of top section 107 , a second frame access opening 166 centrally located along the rear edge of top section 107 , a first frame support opening 181 centrally located along the bottom edge and a second frame support opening 182 centrally located along the top edge (as best shown in FIG. 5 ). Oval section 150 forms the first side section 108 , top section 107 and second side section 109 of canopy 106 . Both sections 150 , 151 are both formed of a pliable material preferably Rip Stop Nylon, but can be made of other suitably pliable material as well.
Still referring to FIG. 5 , oval section 150 is folded along the edge and stitching 153 is provided to form a frame-receiving channel 154 around the periphery of the oval section 150 . A first vent opening 173 is formed in first side section 108 , a second vent opening 174 is provided in second side section 109 and a third vent opening 175 is provided in rear section 110 .
Flexible mesh panels 176 A-C are affixed by stitching 177 over vent openings 173 - 175 , respectively to form a first ventilation window 178 in first side section 108 , a second ventilation window 179 in second side section 109 and a third ventilation window 180 in rear section 110 . Ventilation windows 178 - 180 are provided to aid in airflow circulation.
The flexible mesh panels 176 A-C are preferably provided in the form of green mosquito netting but may be formed of any suitable netting. The ventilation windows 178 , 179 and 180 are depicted in the drawing figures in the form of a half circle but can be provided in any desirable ornamental configuration or shape suitable for appropriate ventilation.
A net storage bag 186 is sewn onto the inner surface of second side surface 109 the canopy 106 for storing personal items of a user, beverages and other refreshments. The bag 186 may be formed with compartments for separating some of the stored items. Bag 186 is mounted so as make the items readily accessible to the user.
In FIG. 7 , the canopy 106 is shown secured to a chair 119 . The net storage bag 186 is located adjacent to the arm of the chair 119 for convenient access to the stored items.
On the back side of the rear section 110 as shown in FIGS. 3 and 5 , there are two quick release web straps 112 having quick release buckles 113 on one end. Web straps 112 are stitched into the lower part of the rear section 110 . The free ends of straps 112 loop around the back of the chair 119 . The second end of each strap 112 is passed through buckles 113 to draw straps 112 tightly around the back of chair 119 and secured by the quick release buckles 113 to support the back of the canopy 106 .
A resilient flexible frame 155 is inserted into the frame-receiving channel 154 to form the overall arch configuration of the canopy 106 as shown in FIGS. 1-3 and 7 . Frame 155 is provided in the form of a first frame rod 156 having a first end 157 and a second end 158 and a second frame rod 159 having a third end 160 and a fourth end 161 . Rods 156 and 159 are inserted into frame receiving channel 154 of oval section 150 and secured. First end 157 of rod 156 and third end of rod 159 are fixedly secured together by a ferrule 162 . Second end 158 of rod 156 and fourth end 161 of rod 159 are fixedly secured together by a ferrule 163 . Rods 156 and 159 of frame 155 are made of any suitable spring-like material; preferably they are ¼ inch solid fiberglass rods held together by ¼ inch ferrules.
A portion of frame rod 159 is accessible through frame support opening 182 and is provided with a double sided hook and loop fastening arm connection strap 184 and an elastic restraining strap 185 . Restraining strap 185 is sized to securely retain canopy 106 in a collapsed position for storage in storage bag 200 .
A portion of frame rod 156 is accessible through frame support opening 181 and is provided with a double-sided hook and loop fastening arm connection strap 183 . The arm connection straps 183 and 184 are connected to the arm support frame or other suitable portion of chair 119 by wrapping the double sided hook and loop fastening arm connection straps 183 and 184 around the arm support frame several times. This provides support for the front of the canopy 106 .
Access to sections 165 and 167 of frame 155 is provided through frame access openings 164 and 167 , respectively. Sections 165 and 167 of resilient flexible frame 155 are used as handles during the removal and collapse of the canopy 106 .
Two tie-down loops 187 are stitched to the front edge of the top section 107 of canopy 106 at approximately 10 O'clock and 2 O'clock position as viewed in FIG. 2 . Tie-down loops 187 provide tie downs points for anchor lines 105 in windy conditions or attachment points for canopy shade 111 .
The canopy shade 111 is provided in the form of a generally round shade body 188 formed of a green mosquito netting but can be made of other suitable netting materials as well. The edge of body 188 is folded and secured by stitching 189 to form a shade frame channel 190 . A frame in the form of spring-like rod 191 is placed in channel 190 with the ends 192 and 193 secured together by a ferrule 194 . Elastic straps 196 are connected to suspender clips 197 and stitched along the edge of the body 188 generally at the 10 O'clock and 2 O'clock position as viewed in FIG. 6 . The clips 197 are used to pivotally attach the canopy shade 111 to the tie-down loops 187 on canopy 106 . A flexible strap 198 is stitched to body 188 at a location opposite the location of attachment of clips 197 .
Shade 111 is collapsible by twisting rod 191 into a figure eight and folding the loops together. Flexible strap 198 is wrapped around the collapsed shade 111 to hold it in the collapsed condition for storage and handling as seen in FIG. 1 .
After the canopy 106 has been removed from the storage bag 200 , the elastic restraining strap 185 is been removed and the canopy 106 tossed away from the user and any other object the resiliency of the frame 155 causes the canopy to self-erect.
Start installation by placing the bottom 171 of the rear section 110 over the arms of the chair and then placing the quick release web strap 112 around back of chair 119 .
To complete installation lift the front of the canopy 106 and attach arm connection straps 183 and 184 to the arms or other front portions of the chair, then return to back of chair 119 and tightened quick release web strap 112 with buckles 113 . Both quick release straps 112 should be taut to support the back of the canopy 106 upon the chair 119 . Removal is opposite of installation.
After removal of canopy 106 (when used on a chair), place the canopy 106 on the ground with the quick release web straps 112 facing to your left.
Grasp resilient flexible frame section 165 with one hand and frame section 167 with the other.
The resilient flexible frame sections 165 and 167 are brought together.
While holding resilient flexible flame sections 165 and 167 together with left hand, rotate the canopy 106 sideways so that the elastic restraining strap 185 is on the bottom and the quick release web straps 112 are facing away from you.
Place your right foot lightly on the edge of the bottom semi circle for stability.
With your right hand fold the top semi circle down past the vertical position and lightly apply downward pressure with your left hand while still holding resilient flexible frame sections 165 and 167 to prevent canopy 106 from unfolding.
Grasp the semi circle furthest away from you with your right hand while still holding semi circle closest to you with your left hand.
Press each semi circle down and toward the center to collapse the canopy 106 .
Once the canopy 106 has collapsed ensure all straps except for the elastic restraining strap 185 are stored inside the collapsed canopy 106 .
Grasp the collapsed canopy 106 with one hand and with the other hand stretch the elastic restraining strap 185 over the canopy 106 to prevent it from unfolding. The canopy 106 is now ready for storage in supplied storage bag 200 .
All straps may be mechanical or stretch material.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims. | The self-erecting and collapsible shade device is provided in the form of a portable collapsible shade assembly. The assembly includes a self-erecting and collapsible canopy, a self-erecting and collapsible canopy shade pivotally mountable to the erected canopy, at least two ground stakes, anchor lines and a storage bag for conveniently carrying the components of the assembly. The erected shade assembly may be secured directly to the ground or affixed to an outdoor chair or seat having a backrest. When the storage bag is empty it is usable as a seat cover to protect the clothing of a user seated beneath the assembly from being soiled by the ground. The assembly may also be used as a hunting blind. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of and claims priority to U.S. Ser. No. 13/402,183 filed Feb. 22, 2012, which is pending and which is hereby incorporated by reference in its entirety for all purposes.
U.S. Ser. No. 13/402,183 is a continuation of and claims priority to U.S. Ser. No. 12/586,253 filed Sep. 18, 2009, now U.S. Pat. No. 8,141,756, and which is hereby incorporated by reference in its entirety for all purposes.
U.S. Ser. No. 12/586,253 claims priority to Italian Application VI2009A000091 filed Apr. 27, 2009, which is hereby incorporated by reference in its entirety for all purposes.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a crown-type sizer to be mounted onto a hanger. More particularly, this invention relates to the combination of a hanger, preferably for underwear, lingerie and similar items, with a crown-type sizer.
2. Description of the Related Art
The use of crown-type sizers is particularly widespread in many sectors, in particular in the large-scale retail trade to identify the products on sale.
In the current state of the art, many known crown sizers have the drawback of being easily detachable from their positioning seat. Such easy removal involves the risk of hangers having missing crown sizers and therefore the risk of having some products exchanged with others by ill-intentioned people during warehouse management or in the stores where the goods are on sale. This negative circumstance can happen in particular when the crown sizer is applied onto clothes hangers for garment size identification marking.
Moreover, since the clothes hangers are normally present in domestic environments, a further risk exists that, since the sizers can be attractive to children due to their reduced size and to their color, they can in particular be mistaken for candy and thus be swallowed, precisely because they are easily detachable.
In the state of art, such as shown in U.S. Design Pat. No. D528,807, in order to prevent such negative possibilities, crown-type sizers have been devised, which are assembled onto a hanger in an integral manner, making them much more difficult to detach and remove; moreover, the possible removal compromises the integrity of the support to the point of making re-use of the hanger for different sized garments impossible.
U.S. Pat. No. 7,240,813 and U.S. Design Pat. No. D510,198 as well as published US 2006/006204 describe examples of crown-type sizers for use with hangers having a metal hook that extends perpendicularly from a clothes hanger body. However, these sizers can not easily be applied onto a hanger made entirely from plastic, as far as the body as well as the hook are concerned, as the hook extends at an angle other than 90.degree. with respect to the body, before taking on the rounded shape of the hook itself.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a crown-type sizer for use on hangers for garments, which can be positioned in a corresponding seat so that the sizer becomes very resistant to possible removal attempts.
It is another object of the invention to provide a crown-type sizer that can be applied onto a hanger entirely made from plastic and which has a plastic hook which extends from a body of the clothes hanger at an angle other than 90.degree.
It is another object of the invention to provide a crown-type sizer for hangers, which is aesthetically pleasing when is applied onto a plastic hanger.
Briefly, the invention provides a crown-type sizer that can be applied onto a plastic hanger having a body and an integral hook extending upwards from the body itself, which consists of a peripheral wall which defines an open base at a bottom end and an open base in the upper part to allow the sizer to pass over the hanger hook.
Moreover, on one of the walls of the sizer there is at least one protrusion boss for engaging the sizer onto the hanger and to ensure that the sizer remains blocked on the hanger itself.
Specifically, the peripheral wall of the sizer includes a pair of, preferably trapezium-shaped, longitudinal sides and a pair of, preferably rectangle-shaped, transverse sides, to form a prism-shaped encasing structure with both bases open and thus to form a sizer which is different and opposite the so called “side” sizer or the classic sizer inserted from the top, as known in the state of art.
Moreover, the longitudinal sides of the peripheral wall have a greater height than that of the transverse sides so as to form a recess or undercut suitable for receiving the body of the hanger; all of this imparts stability to the sizer with respect to the possibility of twisting on the hook of the hanger.
In a preferred embodiment, the hook of the hanger has a groove or cavity that extends along one side and a protrusion inside the groove, whereas the sizer has a protrusion boss on each of the two opposite sides of the peripheral wall to selectively lock into the groove and for engaging with and under the protrusion in the groove to secure the sizer onto the hanger. The presence of the double protrusions on the two sides of the peripheral wall allows the sizer to be placed over the end part of the hook of a hanger that can be indifferently oriented in either one of two possible directions.
In the embodiment in which the hook of the hanger extends from the body of the hanger by an angle other than 90.degree. before taking on the shape of a hook, the protrusion bosses on the peripheral wall allow the sizer to correctly “fit” the hanger, being kept in the correct position by the protrusion located inside the groove of the hook of the hanger.
Moreover, the hook of the hanger is tapered at the free end part so that the free end part of the hook has a thickness which is smaller than the space between a protrusion boss and the opposite side of the peripheral wall of the sizer.
In this embodiment, in order to be able to mount the sizer onto a hanger, the aforementioned sizer is positioned above the tapered end part of the hook and then moved along the hook itself. As the sizer moves along the hook, a protrusion boss of the sizer enters into the groove located on the hook thereby limiting the side-to-side movement of the sizer with respect to the hook.
Continued movement of the sizer brings the protrusion boss on the sizer into abutment with the protrusion of the hook. At that time, the sizer is forced toward the body of the hanger to allow the protrusion boss of the sizer to snap under the protrusion in the groove of the hook, with a “click”, typical of a snap-in locking.
In order to facilitate such an operation, each protrusion boss on the sizer is tapered to facilitate the sliding above the protrusion of the hook towards the body of the hanger and, at the same time, to resist a reverse movement, which must be activated in order to detach the sizer from the hook.
The dimensions of the sizer and of the hanger are such that when a protrusion boss of the sizer snaps-in under the protrusion located in the groove of the hook, the rectangular transverse sides of the peripheral wall of the sizer come to rest on the cross bar of the hanger, arranged in the recess defined in the upper part of the sizer.
Moreover, the upper surface of each protrusion boss of the sizer is flat, as well as perpendicular to the plane of the peripheral wall of the sizer and is therefore opposite the surface of the protrusion on the hook of the hanger. This blocks the sizer from coming off the body of the hanger after having being applied through the aforementioned snap-in operation.
The sizer is particularly useful on a plastic hanger having a hook which extends in a direction opposite the body with an angle other than 90.degree., before taking on the typical hook shape. With such a configuration of the hook, the width of the sizer must be significantly greater than the width of the filiform body which forms the hook, so as to form a space inside of which the hook can extend, with its particular angle. Such a considerable width of the sizer provides a relatively large area for size indicia or other advertising script on the longitudinal walls.
Finally, the offset and asymmetric arrangement of the protrusion bosses inside the sizer allows the sizer to be positioned on the body of the hanger from the moment in which the sizer engages under the protrusion located in the groove of the hook which is arranged laterally with respect to the point in which the hook merges with the body of the hanger.
In another embodiment, a sizer is provided where the protrusion, bosses are spaced apart at a greater distance than the width of the hook of a hanger so that when the sizer is initially slid over the hook, the protrusion bosses are disposed outside of the hook. Once the sizer is seated onto the hanger body, the sizer is slid laterally, i.e. sideways, to slide one or the other of the protrusion bosses into the groove of the hanger hook and under the protrusion of the hook thereby snapping the sizer into place.
In a third embodiment, a sizer is provided that can be slid onto a hook of a hanger and blocked in place as in the first embodiment or that can be slid onto a hook of a hanger and laterally moved into place as in the second embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 illustrates a front view of a hanger at the time a crown sizer in accordance with the invention is to be mounted on the hook thereof;
FIG. 2 illustrates a front view of the hanger of FIG. 1 with a crown sizer in accordance with the invention in place;
FIG. 3 illustrates a part perspective view of the hanger and sizer of FIG. 1 during sliding of the sizer over the hook of the hanger in accordance with the invention;
FIG. 4 illustrates a view similar to FIG. 3 with the sizer blocked onto the hook of the hanger in accordance with the invention;
FIG. 5 illustrates a perspective side view of the sizer of FIG. 3 ;
FIG. 6 illustrates a top view of the sizer of FIG. 5 ;
FIG. 7 illustrates a view of the sizer and hanger taken on line VII-VII of FIG. 2 ;
FIG. 8 illustrates a part perspective view of a hook with a second embodiment of a sizer according to the invention;
FIG. 9 illustrates a front side view of the sizer and hanger of FIG. 8 ;
FIG. 10 illustrates a view taken on line X-X of FIG. 8 ;
FIG. 11 illustrates a perspective view of the sizer of FIG. 8 ;
FIG. 12 illustrates a top view of the sizer of FIG. 11 ;
FIG. 13 illustrates a broken longitudinal front side view of the sizer of FIG. 11 ;
FIG. 14 illustrates a transverse side view of the sizer of FIG. 11 ;
FIG. 15 schematically illustrates the manner of sliding the sizer of FIG. 8 onto a hanger hook in accordance with the invention;
FIG. 15A illustrates a view taken on line XV-XV of FIG. 15 ;
FIG. 16 illustrates the position of the sizer of FIG. 8 on the hanger immediately prior to snapping into place;
FIG. 16A illustrates a view taken on line XVI-XVI of FIG. 16 ;
FIG. 17 illustrates the position of the sizer of FIG. 8 on the hanger after being snapped into place in accordance with the invention;
FIG. 17A illustrates a view taken on line XVII-XVII of FIG. 17 ; and the position of the sizer of FIG. 8 on the hanger immediately prior to snapping into place; and
FIG. 18 illustrates a perspective view of a further embodiment of a sizer in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
As can be seen in FIGS. 1 and 2 , the hanger 1 consists of a monolithic structure of an item made from plastic suitable for its purpose including a body 2 , equipped at the two ends with a clip structure 2 . 1 , suitable for holding one or more lingerie, underwear and similar clothing items, and a hook 3 , which extends upwards from the mid-point of the body 2 and with a lower portion 3 . 1 oriented with an angle to the body 2 which is less than 90.degree.
The hook 3 has a rear portion which is smooth and coplanar with the rear part of the body 2 and a front part where there is a channel-shaped groove 4 , which extends for the entire longitudinal length of the hook 3 . The groove also extends for the entire length of the body 2 .
A tab 5 in the form of an integral protrusion is disposed in the groove 4 at the inclined portion 3 . 1 . The tab 5 extends across the entire width of the channel-shaped groove 4 and is positioned parallel to the body 1 with a lower wall 5 . 1 and, possibly also an upper wall 5 . 2 flat (see FIG. 7 ).
A sizer 10 is fitted onto the hook 2 and blocks itself on the body 1 being kept in position by the tab 5 , in a manner described hereafter.
As can be seen in FIG. 5 , the sizer 10 comprises a peripheral wall which defines an open base “B 1 ” in the lower part and a further open base “B 2 ” in the upper part to allow the hook 3 of the hanger 1 to pass inside the sizer 10 .
The peripheral wall of the sizer 10 is defined by two preferably trapezium-shaped longitudinal walls 11 and by two rectangle-shaped transverse walls 12 , the longitudinal walls 11 having a greater height than the two transverse walls 12 , so as to define a recess 13 suitable for receiving the body 2 of the hanger 1 through lock coupling, when the sizer is positioned.
The sizer 10 is equipped with two protrusion bosses 14 and 15 protruding inside the two longitudinal walls 11 which are in contact with the tab 5 of the hook 2 , when the sizer 10 is in position, ensuring, in such a way, that the sizer 10 is blocked onto the hanger. The two protruding bosses 14 and 15 are on the upper part of the two longitudinal walls 11 and are arranged opposite one another and symmetrically with respect to the mid-point “K” ( FIG. 6 ) of the upper opening “B 2 ”.
Each of the two bosses 14 and 15 has a profile which is tapered towards the lower base “B 1 ” in order to facilitate the sliding of the sizer 10 over the sides of the hook 3 into the groove 4 as well as over the tab 5 of the hook 2 during the movement towards the body 2 of the sizer 10 .
In order to mount the sizer 10 onto the hanger 1 , the open lower base “B 1 ” of the sizer is positioned above the free tapered part 3 . 2 ( FIG. 3 ) of the hook 3 , which has a thickness which is less than the distance between the projections of the two bosses 14 and 15 of the sizer, which is thus free to move sideways.
Once a boss 14 of the sizer 10 is positioned inside the channel-shaped groove 4 of the hook 3 , the sizer 10 is guided by the channel-shaped groove 4 .
With the continuous movement along the hook 3 , the sizer 10 comes into contact, slides and snaps under the tab 5 , which crosses the channel-shaped groove 4 . In such a final position, the upper surface 14 . 1 of the boss 14 of the sizer is positioned below the lower wall 5 . 1 of the tab 5 of the hook; in such a way the sizer 10 cannot be moved backwards any longer due to the presence of the tab 5 , which is in the groove 4 and which blocks any upward movement of the sizer 10 .
Moreover, when the sizer 10 has been snapped into its location, as indicated in FIG. 4 , the body 1 of the hanger is arranged inside the recess 13 , i.e., the sizer 10 is locked or mounted “astride” over the body 1 thus impeding any twisting and/or rotation relative to the aforementioned body 1 .
Referring to FIGS. 8 to 17 , in a second embodiment, the sizer 20 is constructed so as to be slid over the hook 3 of a hanger 1 and then slid laterally into a blocked condition on the hanger.
Referring to FIG. 14 , the sizer 20 is made up of a peripheral wall defined by two, preferably trapezium-shaped longitudinal walls 21 , and two, rectangular-shaped transverse walls 22 , the two transverse walls 22 having a shorter height than the two longitudinal walls 21 , so as to define a lower recess 23 . 1 , suitable for receiving through lock coupling the body 2 , as shown in FIG. 8 , and an upper recess 23 . 2 , to allow the inclined portion 3 . 1 of the hook 3 to come off, as shown in FIG. 8 , all whilst the sizer 20 is snapped into position.
Referring to FIGS. 8 to 10 , the sizer 20 is equipped with two bosses 24 and 25 protruding inside the two longitudinal walls 21 . When the sizer 20 is in position, one or the other of the two protruding bosses 24 , 25 is in contact with the underside of the tab 5 of the hook 2 , as shown in FIG. 10 , ensuring in such a way that the sizer 20 is blocked onto the hanger body 2 .
The two protruding bosses 24 and 25 are on the upper part and at the ends of the two longitudinal walls 21 and are arranged opposite one another and symmetrically with respect to the mid-point “K” of the upper opening “B 2 ” (see FIG. 12 ). As indicated in FIG. 8 , the protrusion bosses 24 and 25 are spaced apart at a greater distance than the width of the hook 3 of the hanger so that when the sizer 20 is initially slid over the hook 3 , the protrusion bosses 24 and 25 are each disposed outside of the hook as indicated in FIG. 15 .
Each of the two bosses 24 and 25 has a profile which is tapered in opposite directions to facilitate the sliding on the side of the hook 3 during the side movement of the sizer 20 .
As can be seen in FIGS. 15 to 17 , in order to mount the sizer 20 onto the hanger 1 , the free end of the hook 3 is fitted onto the sizer, between the two bosses 24 and 25 ; for such a purpose the inner distance between the two longitudinal walls 21 is slightly greater than the thickness of the hook 3 , for which reason the sizer is guided during its sliding along the hook.
With the continuous movement along the hook 3 , the sizer 20 comes into contact and locks into the recess 23 . 1 on the body 1 ( FIGS. 16 and 16A ) and this prevents any twisting and/or rotation relative to the aforementioned body 1 .
With the subsequent horizontal sliding along the body 1 , the sizer 20 slides along the hook 2 and snaps into the tab 5 , which crosses the channel-shaped groove 4 ( FIGS. 17 and 17A ). In such a final position, the boss 24 is contained inside the channel-shaped groove 4 and its upper surface is positioned below the lower wall 5 . 1 of the tab 5 of the hook. In this way, the sizer 10 can no longer slide, due to the presence of the tab 5 , which blocks the sizer 20 from above and due to the channel-shaped groove 4 , which blocks the sizer 20 sideways.
Referring to FIG. 18 , in another embodiment, the sizer 30 sizer is constructed so as to be slid onto a hook of a hanger and blocked in place as in the first embodiment or to be slid onto a hook of a hanger and laterally moved into place as in the second embodiment.
As illustrated, the sizer 30 is made up of a peripheral wall defined by two, preferably trapezium-shaped longitudinal walls 31 and made up of two, rectangle-shaped transverse walls 32 , the transverse walls 32 having a shorter height than the two longitudinal walls 31 , so as to define a lower recess 33 . 1 and an upper recess 33 . 2 . The sizer 30 is also equipped with two bosses 34 and 35 that protrude inside the two longitudinal walls 31 and that have a tapered profile 36 towards the lower base and a further tapered profile 37 with a reciprocally opposite direction to facilitate the sliding of the sizer 30 respectively, over the tab 5 of the hook 2 , during movement downward and on the side of the hook 2 , during lateral movement.
The invention thus provides a sizer with the preferably trapezium-shaped longitudinal walls 11 , 21 or 31 that have a substantial width and therefore provide a surface that allows indicia thereon to show clearly the size of the garment hanging on the hanger.
The sizer 10 , 20 or 30 can be made from any suitable material, preferably from plastic material and the thickness of the longitudinal walls 11 , 21 and 31 , in particular at the bosses 14 , 15 and 24 , 25 as well as 34 , 35 is such as to allow the walls to flex outwards, to allow the bosses to slide over the tab 5 or over the hook 2 , respectively, to snap into the channel-shaped groove 4 of the hook.
Moreover, since the sizer 10 , 20 , 30 has the bosses 14 , 15 and 24 , 25 , as well as 34 , 35 , opposite each other, the sizer is able to slide above the portion 3 . 1 of the hook 3 which extends angularly from the body 1 , at an angle less than 90.degree. and, can be positioned on a hook in either of the two possible positions for display purposes.
Finally, from what has been described thus far it should be understood that once the sizer 10 , 20 , 30 , has been snapped into its foreseen position, the sizer cannot be easily removed from the hanger. In order to do so, a tool must be inserted inside the sizer, in order to allow the bosses 14 , 15 and 24 , 25 , as well as 34 , 35 of the sizer itself to come out of the groove 4 of the hook 2 .
The sizer 10 , 20 , 30 is illustrated and described with respect to a lingerie or underwear hanger; however, the plastic hanger can be of any suitable construction for various types of garments.
The invention further provides a sizer that can easily be mounted on any type of hook or “nail”, which extends and takes on its form angularly from any plastic hanger body. | A crown-type sizer for mounting on a hanger includes a body and a hook extending from a mid-point of the body. The sizer includes a pair of parallel walls and a pair of non-parallel walls, each wall of the non-parallel walls being joined to each wall of the parallel walls, the pairs of walls defining a lower open base and an open base in an upper part of the sizer for passing over the hook. Each of the parallel walls has a single boss disposed in a corner of the respective parallel wall and each non-parallel wall is shorter in height than at least one parallel wall. | 0 |
RELATED APPLICATION
This application is a continuation of application Ser. No. 10/975,646 filed on Oct. 28, 2004.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the production of supported catalysts, more specifically to the method for making heterogeneous catalysts containing nano-meter sized metal particles.
2. Description of the Related Art
Many industrial products such as fuels, lubricants, polymers, fibers, drugs, and other chemicals would not be manufacturable without the use of catalysts. Catalysts are also essential for the reduction of pollutants, particularly air pollutants created during the production of energy and by automobiles. The majority of industrial catalysts are composed of a high surface area support material upon which chemically active metal nanoparticles are dispersed. The support materials are generally inert, ceramic type materials having surface areas on the order of hundreds of square meters/gram. This high specific surface area usually requires a complex internal pore system. The metal nano-particles are deposited on the support and dispersed throughout this internal pore system, and are generally between 1 and 100 nanometers in size. Catalysts of this type are also referred to as heterogeneous catalysts, because the catalyst particles are solid phase, while the reactants interacting with the catalyst are generally liquid or gas phase.
Processes for making supported catalysts go back many years. One such process for making platinum catalysts, for example, involves the contacting of a support material such as alumina with a metal salt solution such as a platinum chloride solution. The salt solution “impregnates” or fills the pores of the support during this process. Following the impregnation, the support containing the salt solution would be air dried, causing the metal salt to precipitate within the pores. The support containing the crystallized metal salt would then be exposed to a hydrogen or carbon monoxide gas environment, reducing the solid metal salt to metal particles. This process, however, made it difficult to produce highly dispersed catalysts because of the difficulty in controlling the precipitated metal salt crystallite sizes and distributions. Often, depending on the reduction conditions, the metal particles would diffuse together creating larger, less desirable particles (sintering).
With the advent of the more recent focus of nanotechnology, methods for fabricating nanometer sized metal particles in liquid solutions have been combined with impregnation techniques to create heterogeneous catalysts. This process offers the potential advantage of being able to determine metal particle size, morphology and particle size distribution prior to impregnation into the support.
Yoo et al., in an article entitled “Propene Hydrogenation Over Truncated Octahedral Pt Nanoparticles Supported on Alumina”, Journal of Catalysis, 214 (2003), pg 1-7, discloses a process for loading colloidal Pt nanoparticles (synthesized by a 1:5 concentration ratio of K 2 PtCl 4 to polyacrylate capping polymer) into an alumina support via impregnation.
Miyazaki et al., in an article entitled “Morphology Control of Platinum Nanoparticles and Their Catalytic Properties”, Journal of Nanoparticle Research, Vol. 5, pg 69-80, 2003, discloses the preparation of Pt nanoparticles of varying morphology through the use of different capping polymers. Various shapes (such as square, triangular, and hexagonal) of platinum crystallites, as observed by transmission electron microscopy, were obtained. Supported catalysts were made by impregnation of previously formed Pt crystallites into an alumina support. Water was removed from the support by freeze drying, and the capping polymers were removed by calcining in air at 500° C. for 8 hours.
U.S. Pat. No. 6,569,358 discloses a method of preparing a porous material incorporating ultrafine metal particles comprising the following steps: (1) preparing surface-protected ultrafine metal particles by reducing metal ions in the presence of molecules such as dodecanethiol molecules; (2) immersing a wet gel in a solution of the ultrafine metal particles, thus forming an ultrafine metal particle/wet gel composite in which the ultrafine metal particles are incorporated in the wet gel; and (3) drying the ultrafine metal particle/wet gel composite to form a porous body.
The aforementioned processes utilize a protecting agent, or capping polymer, to control particle size, morphology, and reduce agglomeration. However, removal of the capping polymers or protecting agents can be an issue for sensitive catalytic processes, as their destruction may leave contaminating residues that are undesirable. These residues may reduce activity of the catalyst by occupying active sites necessary for subsequent reactions. The residues may also leave behind trace quantities of poisons that will eventually kill the catalyst over time. Removal of organic capping agents and polymers usually require oxidation (or burning), the exothermic heat from which can produce unwanted sintering due to the high temperatures. Sintering will increase the metal particle size and reduce the active surface area which is undesirable. Furthermore, the use of capping agents can hinder the introduction of the metal crystallites into small pores of the support.
U.S. Pat. No. 6,686,308 discloses a supported catalyst comprising catalyst metal nanoparticles having an average particle size of typically 2.0 nm or less, which are supported on support particles at a loading of 30% or more. Typical catalyst metals are selected from platinum, palladium, ruthenium, rhodium, iridium, osmium, molybdenum, tungsten, iron, nickel and tin. Typical support particles are carbon. A method of making a supported catalyst comprises the steps of: a) providing a solution of metal chlorides of one or more catalyst metals in solvent system containing at least one polyalcohol, typically ethylene glycol containing less than 2% water; b) forming a colloidal suspension of unprotected catalyst metal nanoparticles by raising the pH of the solution, typically to a pH of 10 or higher, and heating said solution, typically to 125° C. or higher; c) adding support particles to the colloidal suspension; and d) depositing the unprotected catalyst metal nanoparticles on the support particles by lowering the pH of said suspension, typically to a pH of 6.5 or lower.
U.S. Pat. No. 6,603,038 discloses a method for producing a catalyst containing one or several metals from the group of metals comprising the sub-groups Ib and VIIIb of the periodic table on porous support particles, characterized by a first step in which one or several precursors from the group of compounds of metals from sub-groups Ib and VIIIb of the periodic table is or are applied to a porous support, and a second step in which the porous, preferably nanoporous support to which at least one precursor has been applied is treated with at least one reduction agent, to obtain the metal nanoparticles produced in situ in the pores of the support. Catalysts were typically prepared by impregnation of the support with a metal salt solution, followed by a drying step. Subsequent to drying, the impregnated support materials were reduced by various techniques including re-impregnation with liquid reducing agents. Typically, the initial salt impregnation process was performed with support to salt solution ratios on the order of 1 g support/1 ml solution. These impregnation conditions are typical of traditional prior art, and generally result in lower dispersions and poor control of particle sizes and particle size distributions.
What is needed is a catalyst manufacturing process that provides improved control over metal crystallite particle sizes, distributions and morphologies without the contamination of capping agents.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method for producing a catalyst including the steps of (1) contacting a quantity of support with a volume of solvent for a time period, creating a liquid mixture, (2) adding a metal salt to the liquid mixture following the time period, and (3) contacting a reducing agent with the liquid mixture, wherein the metal salt is reduced to metal particles on the surface of the support.
It is an other object of the present invention to provide a method for producing a catalyst including (1) contacting a quantity of support with a volume of solvent, creating a liquid mixture wherein the volume of solvent is greater than two times the pore volume of the quantity of support, (2) adding a metal salt to the liquid mixture and, (3) contacting a reducing agent with the liquid mixture, wherein the metal salt is reduced to metal particles on the surface of the support.
It is yet another object of the present invention to provide a method for producing a catalyst including (1) contacting a quantity of support with a volume of solvent for a time period, creating a liquid mixture wherein the volume of solvent is greater than two times the pore volume of the quantity of support, (2) adding a metal salt to the liquid mixture following the time period and, (3) contacting a reducing agent with the liquid mixture, wherein the metal salt is reduced to metal particles on the surface of the support.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings, wherein:
FIG. 1 is a process flow block diagram of a method for making catalysts according to an embodiment of the present invention; and
FIG. 2 is a chart of CO 2 yield versus reaction temperature for two catalysts made according to embodiments of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a process flow block diagram 100 of a method for making catalysts according to an embodiment of the present invention. Reagents and starting materials for the process are represented schematically by circles 102 - 106 and 120 . In step 108 , solvent 102 and support 104 are combined. Solvent 102 may be any liquid within which metal salt 106 is suitably soluble, is sufficiently pure enough, and can be removed from the support by drying or vacuum evaporation. Such solvents include, but are not limited to water, alcohol, and other organic solvents. Preferably, water is used. More preferably, double de-ionized water is used. Alcohols that are suitable include, but are not limited to methanol and ethanol and their mixtures, with and without water. Other organic solvents include tetrahydrofuran, acetic acid, ethylene glycol, N-methylpyrrolidone, dimethylformamide, dimethylacetalmide, and their mixtures, with and without water. Support 104 materials may include, but are not limited to, alumina, silica, oxides of vanadium, oxides of titanium, oxides of zirconium, oxides of iron, cerium oxides, carbon, zeolites, and molecular sieves. Solvent to support ratios (pore volume basis) are greater than 2 (solvent volume/support pore volume), preferably 10 to 100. As an example, alumina typically has a support pore volume density of 1 cm 3 /g, so the solvent to support ratio for water and alumina, on a weight basis, would be approximately equal to the solvent to support ratio computed on a pore volume basis. For other support/solvent combinations, this may not be the case. However, irrespective of the solvent or support combination, it is important that sufficient solvent be provided to fully wet the entire pore volume of the support, and that additional solvent is provided to ensure “fluid like” behavior of the mixture. In step 110 , solvent 102 and support 104 are mixed for a time period between 1 minute and 24 hours, preferably between 1 and 4 hours. Sufficient agitation to keep the support solids in suspension is desirable. If necessary, the temperature may be adjusted in this step. Typically, ambient temperature is used, within the range of 15 to 30° C.
Steps 108 and 110 distinguish the present invention from the prior art in that the support is pre-wetted with the solvent prior to the addition of the metal salt. These steps ensure uniform (and complete) wetting of the support with the solvent, which enables a more uniform distribution of the metal salt within the pores of the support, and more uniform reduction to metal crystallites in subsequent steps. This process is aided by the use of higher solvent to support ratios, which facilitate transport of metal salts and reducing components into the support pore structures via diffusion. In a typical impregnation process of the prior art, low solvent to support ratios (typically 1.0) are used to ensure that a high percentage of the metal salt is introduced into the pores of the support, leaving a minimum of solution left outside of the support, prior to drying. These conditions often result in high metal salt concentrations within the pores of the support, and potential incomplete wetting of the entire pore structure. High salt concentrations can lead to non-uniform precipitated metal salt distributions as the catalyst undergoes drying and the solutions within the pores become supersaturated.
In step 112 , metal salt 106 is added to the solvent/support mixture. Soluble salts of metals including Pt, Pd, Ru, Rh, Re, Ir, Os, Fe, Co, Ni, Cu, Ag, Au, Zn, Cd, In, Ga, Sn, Pb, Bi, Sb, Ti, Zr, Cr, Mo, W, V, Nb and Mn are suitable. Of the foregoing, soluble salts of Pt, Pd, Ru. Rh, Re, Cu, Au, Re, Ir, Os and Ag are preferable. For example, Pt salts that are suitable include Pt(NO 3 ) 2 , (NH 3 ) 4 Pt(NO 3 ) 2 , H 2 PtCl 6 , K 2 PtCl 4 , (NH 3 ) 4 Pt(OH) 2 , and Cl 4 Pt(NH 3 ) 2 . An example of Cu and Ag salts that are suitable include AgNO 3 , AgCH 3 COO, Cu(NO 3 ) 2 , Cu(CH 3 COO) 2 , and Cu(II)acetylacetonate. An example of suitable Pd salts include Pd(NH 3 ) 4 (NO 3 ) 2 and Pd(NO 3 ) 2 . Following addition of the salt to the solvent/support mixture, concentration of the salt is between 10 −6 M and 1M, preferably between 10 −4 M and 0.1M. The concentration of the salt will depend on the target weight loading of the final catalyst and the solvent to support ratio used in step 108 .
In step 114 , the mixture including the solvent, metal salt, and support are mixed. The mixing time is between 1 and 4 hours, preferably between 1 and 2 hours. Sufficient agitation to keep the support solids in suspension is desirable. Agitation is also required to fully dissolve the salt compounds within the solvent and reduce any salt concentration gradients within the liquid solution. The temperature is the same as previous steps 108 and 110 . In step 116 , the pH and temperature of the solvent, metal salt, and support are adjusted, if required. If the temperature or pH are adjusted, an additional mixing period is provided. The additional mixing period is between 1 and 4 hours, preferably between 1 and 2 hours. In some embodiments of the present invention, only the temperature is adjusted. In other embodiments of the present invention, only the pH is adjusted. In yet other embodiments of the present invention, both pH and temperature are adjusted. In all embodiments, temperature is within a range of approximately 0° C. and 100° C. When pH is adjusted, it is generally within the range of approximately 3 to 11. Nitric acid and ammonium hydroxide are used to adjust the pH, when required.
In step 118 , reducing agent 120 is added to the solvent, support, and metal salt mixture of step 116 . Suitable reducing agents include, but are not limited to H 2 , CO, N 2 H 4 , NH 2 OH, alcohols, citrates such as sodium, potassium, and ammonium citrate; alkali metal borohydrides such as sodium and potassium borohydride; and glycols. Preferably, H 2 , NH 2 OH and N 2 H 4 are used. For the case of reduction by H 2 , an Argon purging step may precede the introduction of hydrogen to de-gas the solution and remove any dissolved oxygen. The quantity of reducing agent added is determined by the amount of metal salt. An amount between 1 and 200 times the stoichiometric requirement needed to reduce the metal salt can be used, preferably between 1 and 10 times the stoichiometric requirement. In step 122 , the reducing agent, solvent, support, and metal salt are mixed while the metal salt is reduced to nanometer sized metal particles or crystallites on the support surfaces within the pores of the support. Sufficient agitation to keep the support solids in suspension is desirable. Agitation is also required to reduce concentration gradients within the liquid solution. Step 122 is carried out for a time period long enough to complete the reduction of the metal salt. For hydrogen reduction, this time period can be between 0.1 to 48 hours, preferably 18-30 hours. For the other reducing agents, the time period can be between 1 minute to 24 hours, preferably between 5 minutes to 8 hours. As the nanometer metal particles are nucleated and grow within the pores, the metal salt concentration in the pores drops, producing a concentration gradient which draws more metal salt into the pores from the bulk solution surrounding the support. The higher solvent to support ratios used in the present invention facilitate this liquid phase diffusion transport, reducing concentration gradients in the bulk fluid by allowing thorough convective mixing of this fluid, unhindered by the solid support particles. At the termination of the process, essentially all of the metal salt is deposited as metal particles within the pores of the support. An additional advantage of the higher solvent to support ratios used in the present invention is a reduction of the potential to nucleate and grown metal crystallites homogeneously in the bulk of the solvent, due to the low concentration of metal salt. This reduces any potential loss of expensive catalyst materials such as Pt or Pd. Attempting to carry out the liquid phase, in-situ reduction process at low solvent to support ratios (near 1.0) could significantly increase the potential homogeneous nucleation and growth of crystallites outside the support. The lower free solution volume combined with high solids content would significantly hinder diffusion transport into the support pore structure, tending to support and enhance any homogeneous nucleation process.
In step 124 , the newly formed catalyst is separated from the remaining solvent by any convenient method, such as conventional filtration, vacuum drying, or freeze drying. In step 126 , the catalyst is dried at an elevated temperature between 100 and 150° C., preferably about 120° C.
The following examples serve to explain and illustrate embodiments of the present invention, without all embodiments being restricted to the examples presented.
In the following examples, particle sizes and distributions were determined by transmission electron microscopy (TEM), as is well known to those skilled in the art. Prior to TEM measurement, the metal particles were separated from the support by dissolving the alumina support in 10-50% HF, by methods well known in the art. Dimension measurements made by TEM are subject to an estimated error of 10%.
In the following examples, a representative catalytic activity was determined by measurement of CO oxidation “light off” temperatures. Prior to the measurement of CO oxidation activity, the catalysts were subjected to a standardized calcining process following air drying. The standardized process consisted of (1) loading the catalyst into a reactor, (2) purging with He to remove air at room temperature, (3) heating the catalyst in 1% oxygen (remainder inert gas) at a rate of 3° C./minute from room temperature to about 500° C., (4) purging for 10 minutes with pure He to remove oxygen (at 500° C.), (5) purging in 5% hydrogen (remainder inert gas) for 1 hour at 500° C., (6) cooling and purging in pure He to cool to room temperature. Without removing the catalyst from the reactor, the CO oxidation was then carried out. The CO oxidation process consisted of (1) purging the reactor with the reaction mixture of 1.4% CO, 5.6% O 2 (balance He) at room temperature, (2) heating the reactor from room temperature to 200° C. at about 2° C./minute with the afore mentioned CO/O 2 mixture. During this heating step, CO 2 yield was measured as a function of temperature. The temperature at 50% CO 2 yield is noted in the examples below.
Example 1
Steps 108 , 110 : 2 g SBA-150 alumina (BET surface area was 150 m 2 /g) was added to 58 ml DDI (double de-ionized) H 2 O and stirred for 2 hours at room temperature.
Steps 112 , 114 : 0.8 ml Pt(NO 3 ) 2 solution (8 mg Pt) was added to the system and stirred for 1.5 hours at room temperature.
Steps 118 , 122 : 2.05×10 −4 moles N 2 H 4 (0.50 ml 0.41 M N 2 H 4 ) was added to the solution and stirred for 2 hours at room temperature.
Steps 124 , 126 : Mixture was filtered, then dried at 120° C. for 2 hours.
The catalyst produced with the example process above had an average Pt particle diameter of 3.17 nanometers+/−a standard deviation of 1.4 nanometers. The range of particle sizes was 1.6 to 14.3 nanometers. The CO oxidation light off temperature (at 50% CO 2 yield) was 134° C. Metal weight loading was 0.4%.
Example 2
Steps 108 , 110 : 2 g SBA-150 alumina (BET surface area was 150 m 2 /g) was added to 60 ml DDI (double de-ionized) H 2 O and stirred for 2 hours at room temperature.
Steps 112 , 114 : 0.8 ml Pt(NO 3 ) 2 solution (8 mg Pt) was added to the system and stirred for 1.5 hours at room temperature.
Steps 118 , 122 : The solution purged with pure Ar for 20 min, then purged with pure H 2 for 10 min while stirring. Then the system was sealed while stirring for 24 hours.
Steps 124 , 126 : Mixture was filtered, then dried at 120° C. for 2 hours.
The catalyst produced with the example process above had an average Pt particle diameter of 3.55 nanometers+/−a standard deviation of 1.2 nanometers. The range of particle sizes was 1.3 to 9.1 nanometers. The CO oxidation light off temperature (at 50% CO 2 yield) was 131° C. Metal weight loading was 0.4%.
Example 3
Steps 108 , 110 : 2 g SBA-150 alumina (BET surface area was 150 m 2 /g) was added to 60 ml DDI (double de-ionized) H 2 O and stirred for 2 hours at room temperature.
Steps 112 , 114 : 0.8 ml Pt(NO 3 ) 2 solution (8 mg Pt) was added to the system and stirred for 1.5 hours at room temperature.
Steps 118 , 122 : 8.2×10 −4 moles NH 2 OH (2.0 ml 0.41 M NH 2 OH) was added to the solution and stirred for 2 hours at room temperature.
Steps 124 , 126 : Mixture was filtered, then dried at 120° C. for 2 hours.
The catalyst produced with the example process above had an average Pt particle diameter of 4.35 nanometers+/−a standard deviation of 1.3 nanometers. The range of particle sizes was 1.7 to 11.7 nanometers. The CO oxidation light off temperature (at 50% CO 2 yield) was 139° C. Metal weight loading was 0.4%.
Example 4
Steps 108 , 110 : 2 g SBA-150 alumina (BET surface area was 150 m 2 /g) was added to 58 ml DDI (double de-ionized) H 2 O and stirred for 2 hours at room temperature.
Steps 112 , 114 : 0.82 ml 0.05 M AgNO 3 solution (4.1×10 −5 moles Ag) was added to the system and stirred for 2 hours at room temperature.
Step 116 : 0.1 M HNO 3 was added to adjust pH of the solution to 3.86 while stirring at about 100° C. for 1.5 hours.
Steps 118 , 122 : 8.157×10 −4 moles N 2 H 4 (0.0739 ml 35% N 2 H 4 ) was added to the solution and stirred for 2 minutes at 100° C. Solution was then cooled to 0° C. and stirred for 2 hours. Solution then heated to room temperature.
Steps 124 , 126 : Mixture was vacuum dried until solid at room temperature, then dried at 120° C. for 2 hours.
The catalyst produced with the example process above had a CO oxidation light off temperature (at 50% CO 2 yield) of 111° C. Metal weight loading was 0.22%.
Example 5
Steps 108 , 110 : 2 g SBA-150 alumina (BET surface area was 150 m 2 /g) was added to 59 ml DDI (double de-ionized) H 2 O and stirred for 2 hours at room temperature.
Steps 112 , 114 : 0.82 ml 0.05 M AgNO 3 solution (4.1×10 −5 moles Ag) was added to the system and stirred for 1.5 hours at room temperature.
Steps 118 , 122 : The solution purged with pure Ar for 20 min, then purged with pure H 2 for 10 min while stirring. Then the system was sealed while stirring for 18 hours.
Steps 124 , 126 : Mixture was vacuum dried until solid at room temperature, then dried at 120° C. for 2 hours.
The catalyst produced with the example process above had a CO oxidation light off temperature (at 50% CO 2 yield) of 140° C. Metal weight loading was 0.22%.
Example 6
Steps 108 , 110 : 2 g SBA-150 alumina (BET surface area was 150 m 2 /g) was added to 60 ml DDI (double de-ionized) H 2 O and stirred for 2 hours at room temperature.
Steps 112 , 114 : 1.54 ml 0.5 M AgNO 3 solution (7.69×10 −4 moles Ag) was added to the system and stirred for 1.5 hours at room temperature.
Steps 118 , 122 : 2.31×10 −3 moles NH 2 OH (1.413 ml 5% NH 2 OH) was added to the solution and stirred for 0.9 hours at room temperature.
Steps 124 , 126 : Mixture was filtered, then dried at 12° C. for 2 hours.
The catalyst produced with the example process above had a CO oxidation light off temperature (at 50% CO 2 yield) of 79° C. Metal weight loading was 4.15%.
Example 7
Steps 108 , 110 : 2 g SBA-150 alumina (BET surface area was 150 m 2 /g) was added to 60 ml DDI (double de-ionized) H 2 O and stirred for 2 hours at room temperature.
Steps 112 , 114 : 0.3075 ml 0.5 M AgNO 3 solution (1.54×10 −4 moles Ag) was added to the system and stirred for 2.2 hours at room temperature.
Steps 118 , 122 : 4.63×10 −4 moles NH 2 OH (1.13 ml of 0.41 M NH 2 OH) was added to the solution and stirred for 1.0 hours at room temperature.
Steps 124 , 126 : Mixture was filtered, then dried at 120° C. for 2 hours.
The catalyst produced with the example process above had a CO oxidation light off temperature (at 50% CO 2 yield) of 116° C. Metal weight loading was 0.83%.
Example 8
Steps 108 , 110 : 2 g SBA-150 alumina (BET surface area was 150 m 2 /g) was added to 60 ml DDI (double de-ionized) H 2 O and stirred for 2 hours at room temperature.
Steps 112 , 114 : 0.82 ml 0.05 M Cu(NO 3 ) 2 solution (4.1×10 −5 moles Cu) was added to the system and stirred for 1.5 hours at room temperature.
Steps 118 , 122 : 4.1×10 −4 moles NH 2 OH (0.0252 ml of 50% NH 2 OH) was added to the solution and stirred for 1.0 hours at room temperature.
Steps 124 , 126 : Mixture was filtered, then dried at 120° C. for 2 hours.
The catalyst produced with the example process above had a CO oxidation light off temperature (at 50% CO 2 yield) of 195° C. Metal weight loading was 0.13%.
Example 9
Steps 108 , 110 : 2 g SBA-150 alumina (BET surface area was 150 m 2 /g) was added to 60 ml DDI (double de-ionized) H 2 O and stirred for 1.5 hours at room temperature.
Steps 112 , 114 : 0.8 ml 0.05125 M Pd(NH 3 ) 4 (NO 3 ) 2 solution (4.364 mg Pd) was added to the system and stirred for 2.0 hours at room temperature.
Steps 118 , 122 : 8.2×10 −4 moles NH 2 OH (2.0 ml of 0.41 M NH 2 OH) was added to the solution, and stirred for 2.0 hours at room temperature.
Steps 124 , 126 : Mixture was filtered at room temperature, then dried at 120° C. for 2 hours.
The catalyst produced with the example process above had a CO oxidation light off temperature (at 50% CO 2 yield) of 125° C. Metal weight loading was 0.218%.
Example 10
Steps 108 , 110 : 2 g SBA-150 alumina (BET surface area was 150 m 2 /g) was added to 60 ml DDI (double de-ionized) H 2 O and stirred for 2 hours at room temperature.
Steps 112 , 114 : 1.54 ml 0.5 M Cu(NO 3 ) 2 solution (7.69×10 −4 moles Cu) was added to the system and stirred for 1.6 hours at room temperature.
Steps 118 , 122 : 1.54×10 −3 moles NH 2 OH (3.75 ml of 0.41 M NH 2 OH) was added to the solution and stirred for 5 minutes at room temperature.
Steps 124 , 126 : Mixture was filtered, then dried at 120° C. for 2 hours.
The catalyst produced with the example process above had a CO oxidation light off temperature (at 50% CO 2 yield) of 105° C. Metal weight loading was 2.44%.
Example 11
Steps 108 , 110 : 2 g SBA-150 alumina (BET surface area was 150 m 2 /g) was added to 60 ml DDI (double de-ionized) H 2 O and stirred for 2 hours at room temperature.
Steps 112 , 114 : 4.1 ml 0.5 M Cu(NO 3 ) 2 solution (2.05×10 −3 moles Cu) was added to the system and stirred for 2.8 hours at room temperature.
Steps 118 , 122 : 1.23×10 −2 moles NH 2 OH (0.754 ml of 50% NH 2 OH) was added to the solution and stirred for 8 hours at room temperature.
Steps 124 , 126 : Mixture was filtered, then dried at 120° C. for 2 hours.
The catalyst produced with the example process above had a CO oxidation light off temperature (at 50% CO 2 yield) of 69° C. Metal weight loading was 6.51%.
FIG. 2 is a chart of CO 2 yield versus reaction temperature for two catalysts made according to embodiments of the present invention. Curve 302 is the “light off” curve for CO oxidation to CO 2 for the Pt catalyst made in Example 2 above. The CO oxidation light off temperature at 50% CO 2 yield is shown by ref 306 as about 131° C.
The present invention is not limited by the previous embodiments heretofore described. Rather, the scope of the present invention is to be defined by these descriptions taken together with the attached claims and their equivalents. | A method for producing highly dispersed catalysts is disclosed. The method includes contacting a support material with a solvent for a period of time, adding a metal salt to the solvent and support mixture, and then adding a reducing agent to the solution to reduce the metal salt to nanometer sized metal particles on the surface of the support. Excess solvent is used in the process, the volume of solvent being greater than two times the pore volume of the support. | 1 |
BACKGROUND OF THE INVENTION
1) Field of the Invention
This invention relates to a folding container and in particular to but not exclusively to a packing case, a shipping crate or a freight container.
2) Description of the Related Art
Containers are required for a variety of purposes and, in many circumstances, such as moving automotive parts or possessions between houses or flats and in the case of mobile offices, it is necessary for the container to be sufficiently sturdy to protect the container contents from damage when it is moved or accidentally knocked. However, such a container is unlikely to be in constant use, and as a result it would be advantageous if it could be stored in a flat condition when it is not required.
Containers having opposing side walls which fold onto a base panel have been described in DE 1 144 178 and DE 2 139 147.
U.S. Pat. No. 3,941,271 relates to a collapsible receptacle having inwardly and outwardly directed projections on a base panel frame and sidewalls. The outwardly directed projection of the sidewall overlaps the inwardly directed projection of the base panel frame to maintain the receptacle in the assembled non-collapsed condition such that a tilting of the sidewalls is necessary to raise the sidewall.
U.S. Pat. No. 5,642,830 describes a container having top and bottom members, and columnar members which are received in the top and bottom members when the container is in the assembled condition. When the container is disassembled the columnar members and side members may be stored inside the top and bottom members which are jointed together so that the disassembled container forms an integral unit.
A collapsible container is described in EP 1 028 061 having side panels associated with a base panel and movable between a collapsed and an assembled condition. The container is releasably retained in the assembled condition by side supports engaging adjacent side panels, the side supports comprising upright members demountably secured to the base panel and received and retained by a receptacle secured at or adjacent to the corners of the base panel.
There remains, however, a need for a compact, economical folding container design which can be readily converted from a folded to an unfolded state and which is adaptable for industrial use e.g. in shipping and intermodal containers.
SUMMARY OF THE INVENTION
A preferred feature of the present invention is directed to a folding container comprising a base panel, side support means upstanding from the corners of the base panel, side panels located between the side support means and arranged to bound a storage space, and pivot means arranged to pivotally mount the side panels onto the side support means,
wherein the pivot means for each side panel is disposed in a different horizontal plane to that of any other panel, such that when the container is in a folded state the side panels lie stacked substantially parallel to the base panel, and when in an unfolded state the side panels are substantially orthogonal to the base panel.
In a preferred embodiment the side support means includes a two part columnar member comprising a first member adjacent to the base panel and a second member remote from the base panel, the second member being pivotally secured to the first member at a position such that when the container is in the folded state the second member can be folded onto a surface of an upper one of the stacked side panels.
Preferably each side panel is pivotally mounted onto each of two adjacent side support means. More preferably each side panel substantially occupies a space between adjacent support means onto which each side panel is mounted.
Preferably the pivot means of each side panel comprises a male means cooperating with a slot in an edge of the side panel which is adjacent to the side support means when the container is unfolded, wherein said slot is terminated.
The male means may be arranged to be a free sliding fit along the length of a mating slot in each of the panel edges.
Preferably the male means comprises a pair of circularly cross sectioned pins located on adjacent side support means, wherein each pair of pins is arranged to mount side panels each at a different distance from the base panel.
In a preferred embodiment a first pair of pins associated with a first side panel is located at a distance T-S/2 from the base panel, where T is S+R, S is the thickness of a side panel, and R is the distance between adjacent panels, a second pair of pins associated with a second side panel is located at a second distance, which is 2T-S/2 from the base panel, a third pair of pins associated with a third side panel is located at a third distance, which is 3T-S/2 from the base panel, and a fourth pair of pins associated with a fourth side panel is located at a fourth distance, which is 4T-S/2 from the base panel.
Securing means may be provided on the side panels to secure each individual side panel in the unfolded state.
A cover panel may be pivotally mounted onto one of the side panels.
Preferably the side panels are formed from metal or plastic sheet material.
In a particularly preferred embodiment the base panel, side panels and support means form an integral unit.
In another embodiment the invention is directed to a folding container comprising a base panel, side support means upstanding from the corners of the base panel, side panels located between the side support means and arranged to bound a storage space, and pivot means arranged to pivotally mount the side panels onto the side support means,
wherein the pivot means for each side panel is disposed in a different horizontal plane to that of any other panel, such that when the container is in a folded state the side panels lie stacked substantially parallel to the base panel, and when in an unfolded state the side panels are substantially orthogonal to the base panel,
and the side support means includes a two part columnar member comprising a first member adjacent to the base panel and a second member remote from the base panel, the second member being pivotally secured to the first member at a position such that when the container is in the folded state the second member can be folded onto a surface of an upper one of the stacked side panels.
In a further embodiment the invention provides for a folding container comprising a base panel, side support means upstanding from the corners of the base panel, side panels located between the side support means and arranged to bound a storage space, and pivot means arranged to pivotally mount the side panels onto the side support means, wherein:
the pivot means for each side panel is disposed in a different horizontal plane to that of any other panel, such that when the container is in a folded state the side panels lie stacked substantially parallel to the base panel, and when in an unfolded state the side panels are substantially orthogonal to the base panel,
the pivot means of each side panel is provided by a slot in each edge of the side panel which are adjacent to the side support means when the container is unfolded, said slot being terminated, and male means located on the side support means arranged to engage with the slots,
the male means comprises a pair of circularly cross sectioned pins located on adjacent side support means, wherein each pair of pins is arranged to mount side panels each at a different distance from the base panel,
and a first pair of pins associated with a first side panel is located at a distance T-S/2 from the base panel, where T is S+R, S is the thickness of a side panel, and R is the distance between adjacent panels,
a second pair of pins associated with a second side panel is located at a second distance, which is 2T-S/2 from the base panel,
a third pair of pins associated with a third side panel is located at a third distance, which is 3T-S/2 from the base panel, and
a fourth pair of pins associated with a fourth side panel is located at a fourth distance, which is 4T-S/2 from the base panel.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be further understood by reference to the accompanying drawings showing an exemplary embodiment thereof.
FIG. 1 is a perspective view of a preferred embodiment of a container in accordance with this invention in a folded state,
FIG. 2 is a top view of the container in an unfolded state,
FIG. 3 is a perspective view of a side panel of the container,
FIG. 4 is a perspective view of a base panel of the container,
FIGS. 5 and 6 show mutually orthogonal side views of a side support means in an unfolded state,
FIGS. 7 a and 7 b show side views of the side support means in different operational states thereof,
FIG. 8 is a perspective view of the container shown in FIG. 1 with the side support means partially unfolded,
FIGS. 9 , 10 and FIGS. 11 , 12 respectively show alternative constructions for moving a side panel from a folded to an unfolded state,
FIGS. 13 shows a side panel onto which a cover panel is to be mounted,
FIGS. 14 a and 14 b show a pivoting arm of the side panel of FIG. 13 in different operational states,
FIGS. 15 and 16 show a cover panel being moved from a folded to an unfolded state, and
FIG. 17 shows the fully unfolded container with side panels secured.
In the Figures like reference numerals have the like parts.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The folded container illustrated in FIG. 1 has a substantially rectangular base panel 1 , four side panels 2 stacked on top of the base panel, and four two-part side support tubes 3 upstanding from the corners of the base panel, each support tube having a lower member 4 adjacent to the base panel and an upper member 5 remote from the base panel. The support tubes 3 have a circular cross section but it will be understood that other suitable cross sections may be used. The upper member 5 is pivotally secured to the lower member 4 and is folded onto the surface 6 of the upper stacked side panel. The base panel 1 , side panels 2 and side support tubes 3 are formed from metal sheet material.
Referring to FIG. 2 , each of the side panels 2 in the unfolded container occupies the space between two adjacent side support tubes 3 onto which the side panels are pivotally mounted, as will now be described.
FIG. 3 shows a side panel 2 having a terminated longitudinal slot 7 in one edge 8 . A similar slot is located in the opposing edge of the side panel.
Four pairs of laterally projecting cylindrical pins 9 , 10 , 11 and 12 are located on the lower members 4 of adjacent support tubes as shown in FIG. 4 . Each pair of pins is located at a different distance from the base panel with respect to any of the other pairs. Preferably the first pair of pins 9 closest to the base panel are located at a distance T-S/2 from the base panel, where T is S+R, S is the thickness of a side panel, and R is the distance between adjacent side panels, the second pair of pins 10 at a distance 2T-S/2 from the base panel, the third pair of pins 11 at a distance 3T-S/2 from the base panel, and the fourth pair of pins 12 furthest from the base panel are at a distance 4T-S/2 from the base panel.
Each side panel 2 is mounted onto adjacent support tubes 3 by engagement of the relevant pair of slots 7 in the side panel edges 8 with a corresponding pair of cylindrical pins 12 as shown in FIG. 11 . Each slot 7 is closed at opposing ends to retain the pin 12 associated therewith. The pins 12 engage with the slots 7 in a free sliding fashion so that the side panel 2 can undergo translational movement in the slot plane as well as pivotal movement about the pin axis. The spacing of the pairs of pins 12 from the base panel 1 ensures that in the folded state the side panels 2 stack together in different horizontal planes overlying the base panel 1 as shown in FIG. 1 .
Referring to FIGS. 5 and 7 a, the upper member 5 of a side support tube 3 has an extension 50 formed by a pair of opposed flat surfaces 13 projecting from its lower end with a longitudinal opening 14 therein. Part of the wall of the lower member 4 of the side support tube 3 projects vertically from its upper end to form two opposing end pieces 15 , each end piece having a circular hole 16 located therein as shown in the mutually orthogonal side views of FIGS. 5 and 6 . The opposing end pieces 15 define a recess 17 , which partially extends into the tubular lower member 4 , and which is dimensioned so as to receive the extension 50 of the upper member 5 in close fitting engagement, with the holes 16 aligning with the longitudinal opening 14 of the extension 50 . A cylindrically cross sectioned bar 18 projects laterally through opposing holes 16 and opening 14 so as to retain the upper member 5 of the side support within the lower member 4 . The bar 18 is in sliding engagement with the extension 50 so that the upper member 5 can be vertically extended with respect to the lower member 4 ( FIG. 7 a ).
Referring to FIGS. 7 a and 7 b the side support 3 can be moved from a substantially vertical unfolded position to a folded position substantially perpendicular to the lower member 4 by extending the upper member 5 until the lower edge 19 of the extension 50 is clear of the upper edge 20 of the lower member followed by rotation of the upper member 5 about the axis of the bar 18 .
In erecting the container from a collapsed, folded condition, a first step is to rotate the upper members 5 of the four side support tubes 3 in turn from the folded position, where the upper members 5 are lying on the surface 6 of the uppermost side panel 2 as shown in FIG. 1 , to the unfolded position where the upper members 5 are substantially vertical and form continuous columns with the corresponding lower members 4 as shown in FIG. 8 .
In a second step each side panel 2 of the container is moved in turn from a folded to an unfolded position and preferably fastened to adjacent side support tubes 3 before the next side panel is unfolded. There are two alternative methods for performing this step as shown in FIGS. 9 , 10 and in FIGS. 11 , 12 respectively.
In a first method the edge 21 of the uppermost side panel 2 furthest from the side support tubes 3 onto which it is mounted is raised and rotated upwards towards the side support tubes 3 (shown in FIG. 9 ). When the side panel 2 is in a substantially vertical position, with the opposing edges 8 parallel to the corresponding side support tubes 3 , the side panel 2 is lowered vertically towards the container base panel 1 and into the unfolded position with a bottom edge 22 of the side panel resting on the upper surface of the base panel 1 (shown in FIG. 10 ). The side panel 2 is then fastened to adjacent side support tubes 3 by sliding engagement of bolts 34 secured to the side panel 2 within corresponding recesses 37 in the side support tubes 3 . The process is repeated for the remaining side panels in turn.
In a second method the uppermost side panel 2 is slid in a substantially horizontal plane outwards between the side support tubes 3 onto which it is mounted (shown in FIG. 11 ). When the side panel 2 has been translated in this plane as far from the side support tubes 3 as the slots 7 in the edges 8 will allow, the edge 23 of the side panel 2 furthest from the side support tubes 3 is raised and rotated upwards towards the side support tubes 3 (shown in FIG. 12 ). When the side panel 2 is in a substantially vertical position, with the opposing pivoting edges 8 parallel to the corresponding side support tubes 3 , the side panel 2 is lowered vertically towards the container base panel 1 and into the unfolded position with the bottom edge of the side panel resting on the upper surface of the base panel 1 . The side panel 2 is then fastened to adjacent side support tubes 3 as described in the first method. The process is repeated for the remaining side panels in turn.
A cover panel 30 is pivotally mounted onto the side panel 2 that is uppermost when the container is in the folded state by pivoted arms 24 as shown in FIGS. 13-15 . Each arm 24 has a pin 29 arranged to co-operate with a slot 31 in opposing edges 32 of the cover panel 30 . The arm 24 also has an arcuate slot 25 cooperating with a pin 27 extending laterally through the curved slot 25 and in free sliding engagement therein. The arm 24 is secured to the edge 8 of the side panel 2 by a pin 26 ( FIG. 14 a ). The arm 24 can be partially rotated from a vertical position by pivoting about the pin 26 and sliding of the pin 27 through the slot 25 as shown in FIG. 14 b.
When all four side panels 2 have been moved from the folded to the unfolded position the upper edge 33 of the cover panel 30 is moved from a position substantially parallel to the major face of the side panel onto which it is mounted to an angled position by rotation of the arm 24 about the pin 26 as described above as shown in FIG. 15 . The cover panel 30 is then moved upwards and away from the side panel 2 as shown in FIG. 16 by rotation about the pin 24 and sliding of the pin 24 along the slot 31 in the edge 32 of the cover panel 30 until it is resting on the upper edges of a front side panel 35 and a rear side panel 36 and substantially parallel to the container base panel 1 as shown in FIG. 17 .
The container is unfolded to a collapsed condition by reversing the steps described above.
The person of ordinary skill in the art will appreciate that many modifications to the described embodiment are possible without departing from the spirit and scope of the invention defined in the appended claims. For instance wheels can be adapted to the base panel; the side support tubes may have any suitable transverse cross section; although the panels are preferably formed from metal, they could be formed of plastics or any other suitable material; the container can be suited for different uses and be of different sizes. | A folding container has a base, side support tubes upstanding from the corners of the base, and side panels located between the side support tubes and arranged to bound a storage space. Pivots are arranged to pivotally mount the side panels onto the side support tubes. The pivot for each side panel is disposed in a different horizontal plane to that of any other panel, such that when the container is in a folded state the side panels lie stacked substantially parallel to the base, and when in an unfolded state the side panels are substantially orthogonal to the base. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a scanning printer or similar image-forming apparatus.
2. Discussion of Background
A recent development in connection with image-forming apparatus such as photocopiers, etc. is a portable scanning printer using batteries as a power supply. With this scanning printer, an original document placed on an original document table is scanned in a set direction and has its image information read by a scanner section consisting of an optical system and a CCD (charge coupled device) or similar photosensitive element, and a thermal head is driven in accordance with the image information that has been read to form an image by effecting transfer of a corresponding image onto copy paper.
However, when an image corresponding to an original document is formed by an apparatus such as this, the formation of the image is effected by moving the optical system in the scanner section with respect to the whole surface of the original document table, irrespective of the size of the original document. Because of this, there is wasteful scanning action and the battery life is shortened. Further, there is wasteful return action, since the optical system always starts from one side of the original document table.
OBJECT OF THE INVENTION
It is the object of the present invention to provide an image-forming apparatus which is designed to shorten the image formation time and to save power by shortening of the distance over which an optical scanning means moves.
SUMMARY OF THE INVENTION
In order to achieve the above object, the image-forming apparatus of the present invention is an apparatus such that at the start of scanning by a scanning means that effects optical scanning of an original document placed on an original document table, the current position of the scanning means and the positions f opposite sides of an original document as judged on the basis of the original document size are compared and image formation is started after the scanning means has been moved in accordance with the findings of this comparison to the nearer of the sides.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the external appearance of the image-forming apparatus of the present invention;
FIG. 2 is a perspective view showing the control section of the image-forming apparatus shown in FIG. 1;
FIG. 3 is a front view showing the interior of the image-forming apparatus shown in FIG. 1;
FIG. 4 is a perspective view showing the structure of an optical carriage that is shown in FIG. 3;
FIG. 5 is a block diagram for explanation of the electrical operation of the image-forming apparatus of the invention; FIG. 6 is a plane view of an original document table showing how the optical carriage moves with respect to an original document;
FIG. 7 is a plane view showing copy paper on which a copy has been made on execution of a copying operation with respect to the original document shown in FIG. 6;
FIG. 8 is a plane view of an original document table showing how the optical carriage moves with respect to an original document;
FIG. 9 is a plane view showing copy paper on which a copy has been made on execution of a copying operation with respect to the original document shown in FIG. 8;
FIG. 10 is a plane view of the original document table showing how the optical system moves with respect to an original document;
FIG. 11 is a plane view showing copy paper on which a copy has been made on execution of a copying operation with respect to the original document shown in FIG. 10; and
FIG. 12 is a flowchart for explaining the operation of the image-forming apparatus of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A description of one embodiment of the present invention will now be given with reference to the drawings.
FIG. 1 is a general sketch showing the external appearance of a scanning printer as an image-forming apparatus of the present invention. A main body 1 is rectangular and on its upper surface there is provided an original document table (transparent glass plate ) 3 for supporting an original document G that is, e.g., size A4 or size B5, etc. An openable and closable original document cover 4 is provided near original document table 3. As shown in FIG. 2, on the front surface, which goes along a long side of main body 1, there is provided a control panel 2 constituted by a print start switch 2a, a sheet number specification switch 2b for setting the number of sheets that are printed, a sheet number display section 2c that displays a printed sheet number 1-9 that is set by sheet number specification switch 2b, a density adjustment key 2d, an original document size specification key 2e and an original document size display section 2f in which LEDs light up to display the original document size selected by original document size selection key 2e.
In the rear edge portion going along a long side of main body 1, there is provided a paper opening 5 for permitting insertion and discharge of paper P as recording material. In a side surface of main body 1, there is a ribbon cassette loading port 6 on which there is provided an openable and closable cover 6a. A power supply switch 7 is provided alongside loading port 6.
As shown in FIG. 3, at the lower surface side of original document table 3, there is provided a scanning unit 9 that moves reciprocally in the direction of the arrows shown in the drawings and consists of an exposure lamp 11, mirrors 12, 14 and 15 and a lens block 17. The arrangement is such that optical scanning of the surface of an original document by scanning unit 9 results in the image of the original document being focussed on the surface of an image sensor 18 constituted by a photosensitive element, e.g., a CCD (charge-coupled device). Image sensor 18 outputs electrical signals corresponding to the focussed image to a CPU 61 that is described later.
FIG. 4 shows the drive mechanism for causing reciprocal movement of the carriage of scanning unit 9. Mirror 12 and exposure lamp 11 are supported by a first carriage 41a, while mirrors 14 and 15 are supported by a second carriage 41b. These carriages 41a and 41b are guided by guide rails 42a and 42b and can move freely in parallel in the direction of the arrows a and b. In more detail, a 4-phase pulse motor 33 drives a pulley 43, and between this pulley 43 and an idle pulley 45 there extends an endless belt 45 which has an intermediate portion fixed to one end of first carriage 41a supporting mirror 12. Pulse motor 33 is a motor for causing scanning of original documents and it causes movement of exposure lamp 33 and mirrors 12, 14 and 15.
In the guide section 46 of second carriage 42b supporting mirrors 14 and 15, there are two freely rotatable pulleys 47 and 47 that are provided separated from one another in the direction of the axis of rail 42b. A wire 48 extends around and between these pulleys 47 and 47 and has one end fixed to a fixed element 49 and its other end fixed via a coil spring 50 to fixed element 49. One end of first carriage 41a is fixed to an intermediate portion of wire 48. Thus, rotation of pulse motor 33 results in rotation of belt 45 and movement of first carriage 41a, and this is accompanied by movement of second carriage 41b too. As pulleys 47 and 47 serve as running blocks at this time, second carriage 41b moves in the same direction as first carriage 41a but at half its speed. The direction of movement of first and second carriages 41a and 41b is controlled by changing the direction of rotation of pulse motor 33.
As shown in FIG. 3, there is provided a home position detection switch 51a which is actuated through contact with first carriage 41a supporting mirror 12 when exposure lamp 11 and mirrors 12, 14 and 15 are brought into correspondence with the home position. The "home position" means when the position of illumination by exposure lamp 11 is the position at point A shown in FIG. 6. Further, switches 51b, 51c, 51d, 51e and 51f are disposed in order, going from right to left as seen in the drawing, along the path of movement of first carriage 41a. Switch 51b is located in a position corresponding to an A4 original document size, switch 51c in a position corresponding to B5, switch 51d in a position corresponding to A5, switch 51e in a position corresponding to B6 and switch 51f in a position corresponding to A6. Like the abovenoted home position switch 51a, these switches 51b-51f are similarly actuated by contact with carriage 41a.
As shown in FIG. 1 and FIG. 3, printing section 19 is provided in the lower portion of paper opening 5. This printing section 19 consists of a thermal head 23 constituting a recording head, a platen 24 and an ink ribbon cassette 8 with thermal transfer ink ribbon 25 for effecting transfer. The arrangement is such that paper P inserted via paper opening 5 and thermal transfer ink ribbon 25 come into correspondence between platen 24 and thermal head 23. A control section 21 which effects electrical control of the entire apparauts is provided below optical scanning unit 9.
Control section 21 has the configuration shown in FIG. 5. Image information output by image sensor 18 is supplied via an amplifier 60 to CPU 61, which controls the whole apparatus. CPU 61 stores the image information supplied from image sensor 18 in an image processing section 62. Image processing section 62 stores the image information for one picture that has been processed by image sensor 18. Since the direction of feed of paper P is always constant, CPU 61 records signals read by image sensor 18 as they are in image processing section 62 when optical scanning unit 9 moves in direction a, but reverses them and stores them in image processing section 62 when optical scanning unit 9 moves in direction b.
When the image information for one picture is stored in image processing section 62, CPU 61 reads it out sequentially one line at a time and outputs it to a printing control section 63 which serves to drive thermal head 13 and also to effect one-line drive of a pulse motor 64 that drives platen 24 in response to the signals for each line with which it is supplied. CPU 61 also effects control of a drive section 65 that drives pulse motor 33. The arrangement is, for example, such that rotation of pulse motor 33 in the forward direction results in optical scanning unit 9 moving in direction a (forward movement) and reverse rotation of pulse motor 33 results in optical scanning unit 9 moving in direction b (return movement). (See FIG. 3 and FIG. 4.)
CPU 61 can also determine, by means of the detection signals from switches 51a-51f, whether the position at which optical scanning unit 9 is currently halted is the home position or a position corresponding to a particular original document size. Switches 51a-51f are also connected so as to permit control of the position at which unit 9 is halted when it is moved to a position corresponding to an original document size specified by an operator. A power supply 66 is constituted, e.g., by batteries, etc. and serves to drive the various sections noted above.
First and second carriages 41a and 41b of optical scanning unit 9 scan an original document G on original document table 3 upon depression of print switch 2a, and on completion of scanning, they stop in the position in which they are on this completion.
Original document sizes are specified by original document size specification key 2e, and if first and second carriages 41a and 41b are located in the home position when an original document G has been set on the original document table 3, they start scanning from the home position in response to actuation of print start switch 2a. If they are not located in the home position, first and second carriages 41a and 41b are moved by the action of pulse motor 33 to the home position or to the right-hand edge of the original document G, whichever is the nearer, and they start scanning from this position.
In more detail, as shown in the flowchart of FIG. 12, one of the switches 51a-51f detects the position at which carriages 41a and 51b have halted on completion of a print operation by the preceding operator (S1) and this halt position is stored in CPU 61. The operator who is next to effect a print operation presses the original document size specification key 2e to specify the required original document size (S2). The selection signal from specification key 2e is input to CPU 61 and CPU 61 compares (S3) the position corresponding to the original document size specified in step S2 and the halt position detected in step S1. If they are found to be equal in the comparison, i.e., if the result of subtraction between the next position and the previous position is "0", carriages 41a and 41b do not move but remain halted (S4), and this position at which they remain halted constitutes the scanning start position when the next print operation is effected. If the result of the subtraction in step S3 is not "0", the following comparison is made. The distance from the next position to the edge of original document table 3, i.e., to the home position, is compared with the distance that is the difference between the position corresponding to the original document size specified in step S2 and the halt position detected in step S1 to see if it is larger (S5). If the result of the comparison in step S5 shows that it is larger, i.e., if it is found that the home position is nearer than the next position, carriages 41a and 41b are moved by rotation of pulse motor 33 to the position corresponding to the home position (S6), and this position constitutes the scanning start position when the next printing operation is effected. If the result of the comparison in step S5 shows it to be smaller, i.e., the next position is found to be nearer than the home position, carriages 41a and 41b are moved by rotation of pulse motor 33 to the next position (S7) and this position constitutes the scanning start position when the next printing operation is effected.
Then, the scanning start position of carriages 41a and 41b having been set, print start switch 2a is pressed by the operator (S8). Receiving input of a start signal, CPU 61 supplies pulse motor 33 with drive signals to a set number of pulses via a pulse motor drive circuit 65. Hereupon, pulse motor 33 rotates, carriages 41a and 41b are moved a distance corresponding to the original document size, the original document is illuminated by lamp 11 and a scanning operation is carried out (S9). At the scanning end position, one of switches 51a-51f is pressed by carriage 41a or 41b and an end position signal is input to and stored by CPU 61 (S10). There is subsequently a return to step S1 on execution of a printing operation by the next operator.
For example, the previous operator has completed printing for an original document Ga of size B5, and switch 51c detects that carriages 41a and 41b of optical scanning unit 9 are in position B indicated in FIG. 6 and its detection signal is input to CPU 61 (step S1 of FIG. 12). The next operator places an original document Gb of size A4 on original document table 3, inserts paper P via paper opening 5 and specifies the size of original document Gb (size A4) by means of original document size specification key 2e on control panel 2 (step S2 of FIG. 12). CPU 61, having determined that optical scanning unit 9 is in a position corresponding to point B in step S1 of FIG. 12, compares the distances from this point B to point A and point C corresponding to the edges of original document Gb and determines that point C is nearer than point A, the home position (steps S3 and S5 of FIG. 12). In accordance with this findings, CPU 61 drives pulse motor 33 in the forward direction, and optical scanning unit 9 moves to point C and stops (step S6 of FIG. 12).
Then, when the operator presses print start switch 2a (step S8), CPU 61 drives pulse motor 33 in reverse, so moving optical scanning unit 9, i.e., exposure lamp 11 and mirrors 12, 14 and 15, from point C. In other words optical system 9 moves in direction b (return movement). CPU 61 also controls light of exposure lamp 11. As a result, light from exposure lamp 11 is radiated onto original document Gb on original document table 3 (is radiated starting from point C) and is led successively via reflecting mirrors 12, 14 and 15 to irradiate image sensor 18 (step S9), thereby projecting an image corresponding to original document Gb onto image sensor 18. Hereupon, image sensor 18 converts this image into electrical signals and outputs these electrical signals in bit units to CPU 61 via amplifier 60. As a result, CPU 61 reverses the signals supplied from image sensor 18 and stores them in image processing section 62. When illumination up to point A has been effected, CPU 61 stops pulse motor 33, so stopping optical system 9 (step S10). Next, image information for one picture having been stored in image processing section 62, CPU 61 reads it out one line at a time and outputs it to printing control section 63. In response to each line of signals supplied to it, printing control section 63 drives thermal head 23 and effects one-line drive of pulse motor 64 driving platen 24. This results in transfer onto paper P in accordance with thermal head 23 drive and hence formation of an image corresponding to original document Gb. As a result, an image of original document Gb is printed in the print area P6 of paper P, as shown in FIG. 7.
The operator further places a size B6 original document Gc on original document table 3, as shown in FIG. 8, inserts paper P via paper opening 5 and specified the size B6 of original document Gc by means of original document size specification key 2e on control panel 2 (step S2). Hereupon, CPU 61, having determined from the detection signal from switch 51b that optical scanning unit 9 is in a position corresponding to point C (step S1), compares the distances from point C to point A and point D corresponding to the edges of original document Gc and determines that point D is nearer than point A (steps S3 and S5). In accordance with this finding, CPU 61 drives pulse motor 33 in reverse to bring optical scanning unit 9 to point D and then stops it (step S7).
When, next, the operator presses print start switch 2a (step S8), CPU 61 drives pulse motor 33 in reverse, so moving optical scanning unit 9, i.e., exposure lamp 11 and mirrors 12, 14 and 15, from point D. In other words, optical scanning unit 9 moves in direction b (return movement). CPU 61 also controls light of exposure lamp 11. As a result, light from exposure lamp 11 is radiated onto original document Gb on original document support (is radiated starting from point D) and is led successively via reflecting mirrors 12, 14 and 15 to irradiate image sensor 18 (step S9), thereby projecting an image corresponding to original document Gb onto image sensor 18. Hereupon, image sensor 18 converts this image into electrical signals and outputs these electrical signals in bit units to CPU 61 via amplifier 60. As a result, CPU 61 reverses the signals supplied from image sensor 18 and stores them in image processing section 62. When illumination up to point A has been effected, CPU 61 stops pulse motor 33, so stopping optical scanning unit 9 (step S10). Next, image information for one picture having been stored in image processing section 62, CPU 61 reads it out one line at a time and outputs it to printing control section 63. In response to each line of signals supplied to it, printing control section 63 drives thermal head 23 and effects one-line drive of pulse motor 64 driving platen 24. This results in transfer onto paper P in accordance with thermal head 23 drive and hence formation of an image corresponding to original document Gc. As a result, an image of original document Gc is printed in the print area Pc of paper P as show in FIG. 9.
The operator further places a size A4 original document Gd on original document table 3, as shown in FIG. 10, inserts paper P via paper opening 5 and specifies the size A4 of original document Gd by means of original document size specification key 2e on control panel 2 (step S2). Hereupon, CPU 61, having determined from the detection signal from switch 51e that optical scanning unit 9 is in a position corresponding to point D (steps S1), compares the distances from point D to point A and point C corresponding to the edges of original document Gc and determines that point A is nearer than point C (steps S3 and S5). In accordance with this finding, CPU 61 drives pulse motor 33 in reverse to bring optical scanning unit 9 to point A and then stops it (step S6).
When, next, the operator presses print start switch 2a (step S8), CPU 61 drives pulse motor 33 forwards, so moving optical system 9, i.e., exposure lamp 11 and mirrors 12, 14 and 15, from point A. In other words, optical scanning unit 9 moves in direction a (forward movement). CPU 61 also controls light of exposure lamp 11. As a result, light from exposure lamp 11 is radiated onto original document Gd on original document table 3 (is radiated starting from point A) and is led successively via reflecting mirrors 12, 14 and 15 to irradiated image sensor 18 (step S9), thereby projecting an image corresponding to original document Gd onto image sensor 18 (step S9). Hereupon, image sensor 18 converts this image into electrical signals and outputs these electrical signals in bit units to CPU 61 via amplifier 60. As a result, CPU 61 stores the signals supplied from image sensor 18 in image processing section 62. When illumination up to point C has been effected, CPU 61 stops pulse motor 33, so stopping optical system 9 (step S10). Next, image information for one picture having been stored in image processing section 62, CPU 61 reads it out one line at a time and outputs it to printing control section 63. In response to each line of signals supplied to it, printing control section 63 drives thermal head 23 and effects one-line drive of pulse motor 64 driving platen 24. This results in transfer onto paper P in accordance with thermal head 23 drive and hence information of an image corresponding to original document Gd. As a result, an image of original document Gd is printed in the print area Pd of Paper P, as shown in FIG. 11.
As described above, specification of the size of an original document at the start of copying results in a comparison of the distances between the optical system's current position and the opposite edges of the original document and printing is effected by the optical scanning unit being moved on the basis of the finding of this comparison to the edge which is nearer and then effecting movement in correspondence to the original document starting from this edge. Thanks to this, the distance over which the optical scanning unit moves is short (minimum), so making it possible to reduce time and save power and also to improve reliability. It is also made possible to keep battery consumption to a minimum.
Although the printing section was a thermal transfer type using thermal transfer ribbon in the abovedescribed embodiment, it is not limited to this but may also be a heat sensitive type using leuco paper or diazo paper, an ink jet type, a wire dot type or an electrostatic printing type. Also, although the arrangement was one in which, depending on the direction of movement of the optical system, the memory contents supplied to the image processing system are changed, there is no need to change the memory contents if one has an apparatus in which the direction of the paper can be changed. | Image-forming apparatus comprising an original document table on which an original document can be placed, an optical scanning mechanism for optically scanning an original document placed on the original document table, a moving mechanism which can cause reciprocal movement of this optical scanning mechanism parallel to the original document table, a specification switch for specifying the size of an original document placed on the original document table, detection switches which detect the position in which the optical scanning mechanism has been halted after being moved by the moving mechanism, a transferring mechanism that compares a first distance between the halt position of the optical scanning mechanism detected by the detection switches and one edge portion, going in the direction of scanning, of an original document of a size specified by the specification switch and a second distance between the optical scanning mechanism's halt position and the other edge portion of the original document and which can transfer the optical scanning mechanism to the edge portion of the original document which corresponds to that of the first and second distances which has been found to be the shorter in this comparison, a photoreceptor which picks up light reflected from the document on the optical scanning mechanism which has been transferred to the original document's edge portion being caused to scan the original document by the moving mechanism and an image-forming mechanism by which an original document image picked up by the photoreceptor is reproduced on recording material. | 7 |
BACKGROUND OF THE INVENTION
The field of the invention relates to sheet presses for printing individual documents or other articles.
Two types of printing presses are generally well known to the printing industry, these being web presses and sheet presses. The former is used primarily for continuously printing a roll or web of paper or other substrate. The web is subsequently cut to desired lengths. The latter type of press is used for printing individual, pre-cut documents, envelopes or other articles.
A sheet press generally comprises one or more plate cylinders, a blanket cylinder, and an impression cylinder. One of the plate cylinders is typically driven by a power source. A gear drive is provided for coupling these two elements. Ink is provided to the etched plate mounted to the outer surface of the plate cylinder. This ink is transferred by the engagement of the outer surfaces of the plate and blanket cylinders, the latter having an outside surface defined by ink receptive blanket material The paper to be printed passes between the blanket and impression cylinders. A precise gearing arrangement maintains the relative positions of the plate and blanket cylinders when the press is in operation.
A problem occurs in sheet presses when a document is not fed and the plate and blanket cylinders must be separated. Such separation, known as the "off impression" mode, is necessary as too much ink will accumulate on the blanket cylinder if the press is allowed to keep running at this time. However, separation of the cylinders is only accomplished through separation of the gear train which joins these two elements.
Another drawback of presently known sheet presses is the inability to advance or retard the press while it is running. This is due to the fact that the gearing must be so precise that play that would permit such adjustment cannot be allowed. Devices known as indexers are accordingly employed to advance or regard the press while in it is in the static mode. A full 360° of adjustment is possible by using such indexers. Another alternative is to employ a pair of helical gears which are axially displaced with respect to each other. A major disadvantage of this approach is that the plate cylinder can only be displaced by a very limited amount.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a sheet press including a blanket cylinder, a plate cylinder, and means for separating the blanket and plate cylinders without causing misregistration of the two upon their reengagement.
It is another object of the invention to provide a sheet press including means for advancing or retarding the press while it is running.
In accordance with these and other objects of the invention, a sheet type printing press is provided which includes a blanket cylinder, a plate cylinder, means for driving the plate cylinder, the driving means including means for rotationally displacing the plate cylinder with respect to the blanket cylinder while the driving means is in operation, thereby advancing or retarding the image to be printed.
In accordance with a preferred embodiment of the invention, driving means including a harmonic drive are provided for driving the plate cylinder. The circular and dynamic splines of the harmonic drive are maintained under load to prevent misregistration when the blanket and plate cylinders are separated. The harmonic drive allows the press to be retarded or advanced, thereby correcting any misregistration. It also permits the operator to change from one job to another while the press continues to run, simply by causing relative rotation between the plate cylinder shaft and the plate cylinder drive gear.
A method for preventing misregistration of the plate and blanket cylinders of a sheet type printing press is also provided by the invention, the method including the steps of maintaining the circular spline and flexspline of a harmonic drive under load while the cylinders are disengaged from each other.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a sheet type printing press in accordance with the invention;
FIG. 2 is a sectional side elevation view of a portion of said press;
FIG. 3 is an exploded, perspective view of an assembly for driving a plate cylinder of said press; and
FIG. 4 is an enlarged, front elevation view of an assembly for maintaining the circular and dynamic splines of a harmonic drive under constant load.
DETAILED DESCRIPTION OF THE INVENTION
A sheet type printing press 10 as shown in FIG. 1 is provided by the invention. The press includes a blanket cylinder 12, one or more plate cylinders 14, and an impression cylinder 16. Each of the plate cylinders includes a cylindrical surface provided with one or more etchings. A form roller 18 or the like provides ink to the plate cylinder which, in turn, transfers it to the blanket cylinder 12. Each plate cylinder typically transfers a different color ink to the blanket cylinder.
The plate cylinders may be driven in a number of ways. In the embodiment shown in FIG. 1, a drive gear 20 connected to a motor (not shown) drives an idler gear 22 which, in turn, drives one of the plate cylinders. This plate cylinder drives the blanket cylinder while the blanket cylinder drives the other of the two plate cylinders.
The substrate 24 to be printed is passed between the blanket and impression cylinders. Sheet presses are designed for printing pre-cut articles such as paper envelopes. Each article receives a precisely metered amount of ink from the blanket cylinder in a precise location. The plate cylinders and blanket cylinder are all rotated by interengaged drive gears which maintain their alignment as the press is running. Since all of the interconnected gears are under load in operation, there is little chance of the cylinders becoming displaced with respect to each other and causing the images imparted to the blanket cylinder to be misregistered. However, such misregistration can easily occur should it become necessary to separate the plate and blanket cylinders. Separation is necessary when a document is not fed for any reason.
It is also advantageous to be able to rotationally advance or retard the plate cylinders with respect to the blanket cylinder without having to shut down the press. This allows the operator to correct small errors in registration almost instantaneously. It further allows the operator to move quickly to a different job by simply rotating the plate cylinders so that a different etching thereon will be imparted to the blanket cylinder and then printed upon the substrate 24. About ten different images can be etched upon a typical plate cylinder, which would allow ten different jobs to be performed sequentially without having to shut the press off.
Harmonic drives are commercially available differential drive units used for the transmission of power. They are used for providing high ratio, in-line gearing and allowing shaft phasing. Such couplings have heretofore been impractical for sheet type presses as there is far too much play therein.
Referring to FIGS. 2-3, the sheet press according to the invention employs a double harmonic drive assembly 26, which is a commercially available unit. The harmonic drive couples the plate cylinder 14 to the plate cylinder shaft as described below. This allows a differential coupling between the plate cylinder and the plate cylinder shaft. The assembly 26 includes first and second wave generators 28, first and second flexsplines 30, first and second circular splines 32, and first and second dynamic splines 34. The harmonic drive allows one of the plate cylinders 14 to be advanced or retarded in a manner to be explained later.
The assembly shown in FIG. 2 is driven by a gear (not shown) which engages the plate cylinder drive gear 36. The drive gear 36 is supported by a bearing 38 and secured to the harmonic drive housing 40. The harmonic drive housing is secured to a harmonic drive hub 42. The harmonic drive hub includes an axially projecting rim 44, a central bore 46, and six elongated slots 48 positioned within the rim. It is supported by a bearing 50 positioned within this bore. A ring 52 is positioned between the hub 42 and the wave generator of the harmonic drive 26 and provides a reduced friction surface therebetween.
A stub shaft 54 extends through the bearing 50 and is keyed to the wave generator of the harmonic drive 26 which is nearest to it. A bushing 56 mounted to a trim shaft 58 supports the stub shaft 54. This entire assembly is supported by a grounding clamp 59.
The trim shaft 58 is keyed to the other of the two wave generators 28 within the double harmonic drive 26. The trim shaft extends through the plate cylinder shaft 62, which drives one of the plate cylinders 14. The plate cylinder shaft is supported by bearings 60 at each end of the press. A hub 64, which functions as a harmonic drive assembly clamp, anchors the harmonic drive 26 to the plate cylinder shaft. A drive key 66 is provided for connecting the slotted, cylindrical end of this hub 64 to the plate cylinder shaft. A collar 68 is secured to the slotted end of the hub 64 as shown in FIG. 2.
A thrust ring 70 provides a frictionless surface between the harmonic drive 26 and the hub 64 adjacent thereto. Spacers 72, 74 and 76 are positioned as shown in FIG. 2 for taking up any play between the trim and stub shafts and the respective wave generators of the harmonic drive.
When the press is running, the drive gear 36 is engaged, and power is transmitted through the transmission assembly discussed above to the plate cylinder shaft 62. The drive gear 36, harmonic drive housing 40 and harmonic drive hub 44 all rotate in unison about the bearings 38, 50 which support them. One of the circular splines 32 of the wave generator is bolted to the harmonic drive hub, and accordingly rotates therewith. The other of the two circular splines is bolted to the second hub 64, which transmits power to the plate cylinder shaft 62. The rotation of the plate cylinder shaft 62 may be advanced or retarded by turning the trim shaft 58. The trim shaft, being keyed to one of the wave generators of the harmonic drive, turns the wave generator when such adjustment is desired.
One revolution of the trim shaft and associated wave generator causes the dynamic spline to rotate by 1/88 of a turn. Other ratios could alternatively be employed. More or less rotation may be provided depending upon the number of teeth in the various splines of the harmonic drive. The rotation of the hub 64 secured to the harmonic drive, and the plate cylinder shaft connected thereto, are thereby advanced or retarded by a fraction of a turn upon each rotation of the trim shaft. A wheel or other mechanism (not shown) may be secured to the end of the trim shaft for turning it manually or automatically. Since the gear ratio is high in a harmonic drive, there is no problem in turning the trim shaft even while the drive gear 36 is engaged and operating.
Upon disengagement of the drive gear 36, the play or "slop" in the power transmission assembly would likely cause misregistration between the plate and blanket cylinders upon their re-engagement. The harmonic drive hub 42 is accordingly constructed so that the teeth of the circular spline mounted thereto and the teeth of the flexspline associated therewith are always under load. As discussed above, the harmonic drive hub 42 includes elongated slots 48. The bolts connecting the adjoining circular spline 32 to this hub extend through these slots. A bore 78 is provided within the harmonic drive hub which extends from its exterior surface to one of the slots 48. A spacer 80 is positioned within the slot, and receives the bolt. An anti-backlash coil spring 82 is positioned within the bore 78 and extends into the slot where it resiliently urges the spacer in the drive direction. A set screw 84 is provided for adjusting the pressure applied by the spring.
The constant load applied to the harmonic drive allows it to be used in a sheet type press as virtually all of the play throughout the transmission assembly is removed. Misregistration which would otherwise occur when the load imparted from the engaged drive gear is removed, as in the "off impression" mode, is virtually eliminated.
It will be appreciated that more than two plate cylinders may be employed in a sheet press, each being used to transfer a different color ink. In order to correct for misregistration, it is important that at least all but one of the power transmission assemblies for rotating the plate cylinders be provided with the double harmonic drives used in accordance with the invention. This allows relative movement of each plate cylinder with respect to each other. If desired, all of the plate cylinder transmission assemblies may be equipped with harmonic drives. It is important that each of the harmonic drives be spring-biased to remove the play which would otherwise preclude their use in a sheet type printing press.
Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention. | A sheet type printing press is disclosed which includes a transmission assembly that prevents misregistration of plate and blanket cylinders upon their separation. The assembly also permits the press to be advanced or retarded while running to either correct misregistration or to start a new job using the same plate cylinders. A double harmonic drive is used to advance or retard the press. The harmonic drive is mounted to a hub which causes one of the circular splines and flexsplines thereof to be maintained under constant load. Such loading prevents misregistration when the plate cylinder drive gear is disengaged. | 5 |
[0001] This is a Continuation of application Ser. No. 12/289,243, filed Oct. 23, 2008, which in turn is a Continuation of application Ser. No. 10/465,878, filed Jun. 20, 2003, which in turn is a Division of application Ser. No. 10/224,412, filed Aug. 21, 2002, which in turn is a Division of application Ser. No. 09/155,644, filed Oct. 2, 1998, which in turn us the U.S. National Phase of PCT/JP98/00655, filed Feb. 17, 1998, which in turn claims priority of Japanese Application No. 09-032474, filed Feb. 17, 1997, and Japanese Application No. 09-066046, filed Mar. 19, 1997. The disclosure of the prior applications is hereby incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The invention relates to a display apparatus in which a current-driven light-emitting device, such as an organic electro luminescence (hereinafter referred to as “EL”) display device, are driven by using thin-film transistors. More particularly, the invention relates to a current-driven light-emitting display apparatus driven by thin-film-transistors, which realizes the suppression of deterioration with time, and to a method of producing the same.
[0004] 2. Description of Related Art
[0005] The inventor of this invention carefully examined organic EL display devices driven by thin-film transistors, and ascertained the following facts.
[0006] (1) In an organic EL display device driven by thin-film transistors, since the organic EL display device is a direct-current device, direct current also runs through thin-film transistors, which are connected in series to the EL device, for the purpose of controlling it.
[0007] (2) Thin-film transistors are classified into an n-channel type and a p-channel type. These types differ extremely in the manner in which deterioration with time occurs.
[0008] Accordingly, an object of the present invention is to suppress the deterioration with time of thin-film transistors in a current luminescent device driven by the thin-film transistors.
SUMMARY OF THE INVENTION
[0009] (1) In the present invention, there is provided a current-driven light-emitting display apparatus comprising a plurality of scanning lines and a plurality of data lines, thin-film transistors and current luminescent devices being formed in positions corresponding to each of the intersections of the scanning lines and the data lines, wherein at least one of the thin-film transistors is a p-channel type thin-film transistor.
[0010] It is possible to suppress the deterioration with time of a thin-film transistor with this apparatus.
[0011] (2) In the present invention, there is provided a current-driven light-emitting display apparatus in which a plurality of scanning lines a plurality of data lines, common electrodes, and opposite electrodes are formed, with first thin-film transistors being formed in positions corresponding to the intersections of the scanning lines and the data lines, second thin-film transistors, holding capacitors, pixel electrodes, and current luminescent elements, the first thin-film transistors controlling conductivity between the data lines and the holding capacitors by the potentials of the scanning lines, the second thin-film transistors controlling conductivity between the common electrodes and the pixel electrodes by the potentials of the holding capacitors, to thereby control the current which flows through the current luminescent elements provided between the pixel electrodes and the opposite electrodes wherein the second thin-film transistors are p-channel type thin-film transistors.
[0012] (3) In the present invention, there is provided a current-driven light-emitting display apparatus according to (1) or (2), further comprising a driving circuit for driving the current luminescent element, the driving circuit is comprised of the plurality of scanning lines, the plurality of data lines, the thin-film transistors, and the current luminescent elements, which are disposed on the substrate, wherein the p-channel type thin-film transistors are formed in the same step as the thin-film transistors in the driving circuits.
[0013] (4) In the current-driven light-emitting display apparatus according to any of (1) or (3), the thin-film transistors are polysilicon thin-film transistors.
[0014] (5) The invention provides a current-driven light-emitting display apparatus according to (3), wherein the drive circuits comprise complementary type thin-film transistors, the first thin-film transistors are formed in the same step as n-channel type thin-film transistors in the driving circuits, and the second thin-film transistors are formed in the same step as the p-channel type thin-film transistors in the driving circuits.
[0015] According to (5), it is possible to provide a current-driven light-emitting display apparatus, which exhibits high performance with no deterioration with time, without increasing the number of steps for producing the apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a block diagram of the basic structure of a display to which the present invention is applied;
[0017] FIG. 2 is an equivalent circuit diagram of a display device equipped with thin-film transistors according to a first embodiment of the present invention;
[0018] FIG. 3 is a drive voltage diagram of the display device equipped with thin-film transistors according to the first embodiment of the present invention;
[0019] FIG. 4 is a current-voltage characteristic chart of a current-thin-film transistor according to the first embodiment of the present invention;
[0020] FIG. 5 is a current-voltage characteristic chart of an organic EL display device according to the first embodiment of the present invention;
[0021] FIG. 6( a ) is a sectional view of an organic display EL device equipped with thin-film transistors according to the first embodiment of the invention, and FIG. 6( b ) is a plan view of an organic display EL device according to the first embodiment of the present invention;
[0022] FIG. 7 is an equivalent circuit diagram of an organic EL display device equipped with thin-film transistors used in a second embodiment of the present invention;
[0023] FIG. 8 is a drive-voltage diagram of an organic EL display device equipped with thin-film transistors according to the second embodiment of the present invention;
[0024] FIG. 9 is a current-voltage characteristic chart of a current-thin-film transistor according to the second embodiment of the present invention;
[0025] FIG. 10 is a current-voltage characteristic chart of an organic EL display device according to the second embodiment of the present invention;
[0026] FIG. 11( a ) is a sectional view of an organic EL display device equipped with thin-film transistors according to the second embodiment of the present invention, and FIG. 11( b ) is a plan view of an organic EL display device equipped with thin-film transistors according to the second embodiment of the present invention;
[0027] FIG. 12 is a chart showing the deterioration with time of an n-channel type thin-film transistor;
[0028] FIG. 13 is a chart showing the deterioration with time of a p-channel type thin-film transistor; and
[0029] FIG. 14( a )-( d ) are flow diagrams of the process for producing a thin-film-transistor-drive organic EL display device according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The General Structure of an Organic El Display Device
[0030] Referring to the drawings, the preferred embodiments of the present invention will be described.
[0031] As shown in FIG. 1 , the center region of a substrate 1 constitutes a display part. In the outer periphery of the transparent substrate 1 , at the top side of the drawing, a data-side drive circuit 3 , which outputs image signals to data lines 112 , is arranged, and at the left side of the drawing, a scanning-side drive circuit 4 , which outputs scanning signals to scanning lines 111 , is arranged. In these drive circuits 3 and 4 , n-type thin-film transistors and p-type thin-film transistors form complementary type TFTs. These complementary type thin-film transistors are included in shift register circuits, level shift circuits, analog switch circuits, etc.
[0032] Arranged on the transparent substrate 1 are a plurality of scanning lines 111 , and a plurality of data lines 112 extending in a direction perpendicular to the direction in which the scanning lines extend. The intersections of these data lines 112 and scanning lines 111 constitute pixels 7 in the form of a matrix.
[0033] Formed in each of these pixels 7 is a first thin-film transistor (hereinafter referred to as “a switching thin-film transistor”) 121 , in which scanning signals are supplied to a gate electrode 21 (a first gate electrode) through the scanning line 111 . One end of the source/drain region of the switching thin-film transistor 121 is electrically connected to a data line 112 , while the other end of the source/drain region is electrically connected to a potential holding electrode 113 . In addition, a common line 114 is disposed in parallel to the scanning line 111 . Holding capacitor 123 is formed between the common line 114 and the potential holding electrode 113 . The common line is maintained at a controlled potential. Accordingly, when the switching thin-film transistor 121 is turned ON through the selection by a scanning signal, the image signal from the data line 112 is written to the holding capacitor 123 through the switching thin-film transistor.
[0034] The potential holding electrode 113 is electrically connected to the gate electrode of second thin-film transistor 122 (hereinafter referred to as “a current-thin-film transistor”). The one end of the source/drain region of the current-thin-film transistor 122 is electrically connected to a common line 114 , while, the other end of the source/drain region is electrically connected to one electrode 115 of a luminescent element 131 . When the current-thin-film transistor 122 is turned ON, the current of the common line 114 flows to the luminescent element 131 of such as an organic EL display device through the current-thin-film transistor 122 , so that the luminescent element 131 emits light. Further, although one electrode of the holding capacitor is connected to a common line 114 in this arrangement, it is also possible for it to be connected to a capacitance line being provided separately, instead of being connected to the common line 114 . Alternatively, one electrode of the holding capacitor may be connected to an adjacent gate line.
First Embodiment
[0035] FIG. 2 is a block diagram of an organic EL display device equipped with thin-film transistors, according to a first embodiment of the present invention. FIG. 3 is a drive voltage diagram of an organic EL display device with thin-film transistors according to the first embodiment of the present invention. FIG. 4 is a current-voltage characteristic diagram of a current-thin-film transistor according to the first embodiment of the present invention. FIG. 5 is a current-voltage characteristic chart of an organic EL display device, according to the first embodiment of the present invention.
[0036] In FIG. 2 , there are shown a scanning line 111 , a data line 112 , a holding electrode 113 , a common line 114 , a pixel electrode formed of Al 115 , an opposite electrode formed of ITO 116 , a switching thin-film transistor 121 , an n-channel type current-thin-film transistor 122 , a holding capacitor 123 , an organic EL display element 131 (hereinafter referred to as “a forward oriented organic EL display device”) which is caused to emit light by the current flowing to the pixel electrode 115 from the opposite electrode 116 , and the current directions of the organic EL display device 131 and 141 .
[0037] In FIG. 3 , there are shown a scanning potential 211 , a signal potential 212 , a holding potential 213 , a common potential 214 , a pixel potential 215 , and a counter potential 216 . FIG. 3 , only a part of each potential is shown to illustrate the respective potential relationships. The potential of the scanning line 111 corresponds to the scanning potential 211 ; the potential of the data line 112 corresponds to the signal potential 212 ; the potential of the holding electrode 113 corresponds to the holding potential 213 ; the potential of the common line 114 corresponds to the common potential 214 ; the potential of the pixel electrode 115 formed of Al corresponds to the pixel potential 215 ; and the potential of the opposite electrode 116 formed of ITO (Indium Tin oxide) corresponds to the counter potential 216 . FIG. 3 shows each signal potential schematically and partially.
[0038] Numeral 221 indicates a period in which a pixel is in the display-state, wherein current flows into the forward oriented organic EL display element 131 , so that it emits light, and numeral 222 indicates a period in which the pixel is in the non-display state, wherein current does not flow into the forward oriented organic EL display element 131 , so that it does not emit light.
[0039] Referring to FIG. 4 , a curve 31 indicates the current-voltage characteristic of the n-channel type current-thin-film transistor 122 as observed when the drain voltage is 4V, and a curve 32 indicates the current-voltage characteristic of the n-channel type current-thin-film transistor 122 as observed when the drain voltage is 8V. Regarding either drain voltage, the following facts can been seen. When the gate voltage is low, the n-channel type current-thin-film transistor 122 is turned OFF and a small amount of drain current flows demonstrating a high source/drain resistance. When the gate voltage is high, the n-channel type current-thin-film transistor 122 is turned ON and a large amount of drain current flows demonstrating a low source/drain resistance.
[0040] In FIG. 5 , numeral 4 indicates the current-voltage characteristic of the forward oriented organic EL display element 131 . Here, the voltage represents the counter potential 216 against the pixel potential 215 , and the current represents the current which flows to the pixel electrode 115 from the opposite electrode 116 . The forward oriented organic EL display element 131 is OFF when the voltage is not higher than a certain threshold voltage; the resistance is high and allows no current to flow, so that the device does not emit light. The device is ON when the voltage is over a certain threshold voltage, and the resistance is low and allows current to flow, so that the device emits light. In this case, the threshold voltage is approximately 2V.
[0041] The operation of an organic EL display device equipped with the thin-film transistors of this embodiment will be described with reference to FIG. 2 , FIG. 3 , FIG. 4 , and FIG. 5 .
[0042] The switching thin-film transistor 121 controls the conductivity between the data line 112 and the holding electrode 113 by means of the potential of the scanning line 111 . In other words, the scanning potential 211 controls the conductivity between the signal potential 212 and the holding potential 213 . While in this example, the switching thin-film transistor 121 is an n-channel type thin-film transistor, a p-channel type thin-film transistor is also applicable.
[0043] For the period 221 in which the pixel is in the display-state, the signal potential 212 is high, and the holding potential 213 is retained at a high level. For the period 222 in which the pixel is in the non-display state, the signal potential 212 is low, and the holding potential 213 is retained at a low level.
[0044] The n-channel type current-thin-film transistor 122 has the characteristic as shown in FIG. 3 and controls the conductivity between the common line 114 and the pixel electrode 115 by means of the potential of the holding electrode 113 . In other words, the holding potential 213 controls the conductivity between the common potential 214 and the pixel potential 222 . For the period 221 in which the pixel is in the display-state, the holding potential 213 is high, so that the common line 114 is electrically connected to the pixel electrode 115 . For the period 222 in which the pixel is in the non-display state, the holding potential 213 is low, so that the common line 114 is disconnected from the pixel electrode 115 .
[0045] The organic EL display element 131 has the characteristic as shown in FIG. 5 . For the period 221 in which the pixel is in the display-state, the current flows between the pixel electrode 115 and the opposite electrode 116 , so that the organic EL display element 131 emits light. For the period 222 in which the pixel is in the non-display state, no current flows, so that the device does not emit light.
[0046] FIG. 6( a ) is a sectional view of a thin-film transistor organic EL display device (1 pixel) according to an embodiment of the present invention. FIG. 6( b ) is a plan view of a thin-film transistor organic EL display device (1 pixel) according to an embodiment of the present invention. The section taken along the line A-A′ of FIG. 6( a ) corresponds to the section taken along the line A-A′ of FIG. 6( b ).
[0047] In FIG. 6( a ), numeral 132 indicates a hole injection layer, numeral 133 indicates an organic EL layer, and numeral 151 indicates a resist.
[0048] In this example, the switching thin-film transistor 121 and the n-channel type current-thin-film transistor 122 adopt the structure and the process ordinarily used for a low-temperature polysilicon thin-film transistor, which are used for thin-film transistor liquid crystal display devices, i.e., a top-gate structure and a process conducted in the condition that the maximum temperature is 600° C. or less. However, other structures and processes are also applicable.
[0049] The forward oriented organic EL display element 131 is formed by the pixel electrode 115 formed of Al, the opposite electrode 116 formed of ITO, the hole injection layer 132 , and the organic EL layer 133 . In the forward oriented organic EL display element 131 , the direction of current of the organic EL display device, indicated at 141 , can be set from the opposite electrode 116 formed of ITO to the pixel electrode 115 formed of Al. Further, the structure of the organic EL display device is not restricted to the one used here. Other structures are also applicable, as long as the direction of current of the organic EL display device, indicated at 141 , can be set to the direction from the opposite electrode to pixel electrode.
[0050] Here, the hole injection layer 132 and the organic EL layer 133 are formed by an ink-jet printing method, employing the resist 151 as a separating structure between the pixels, and the opposite electrode 116 formed of ITO is formed by a sputtering method, yet other methods are also applicable.
[0051] In this embodiment, the common potential 214 is lower than the counter potential 216 , and the current-thin-film transistor is the n-channel type current-thin-film transistor 122 .
[0052] In the period 221 in which the pixel is in the display-state, the n-channel type current-thin-film transistor 122 is ON. The current which flows through the forward oriented organic EL display element 131 , i.e., the ON-current of the n-channel type current-thin-film transistor 122 depends on the gate voltage, as shown in FIG. 4 . Here, the term “gate voltage” means the potential difference between the holding potential 213 and the lower one of the common potential 214 and the pixel potential 215 . In this embodiment, the common potential 214 is lower than the pixel potential 215 , so that the gate voltage indicates the potential difference between the holding potential 213 and the common potential 214 . The potential difference can be sufficiently large, so that a sufficiently large amount of ON-current is obtainable. The ON-current of the n-channel type current-thin-film transistor 122 also depends on the drain voltage. However, this does not affect the above situation.
[0053] Conversely, in order to obtain a necessary amount of ON-current, the holding potential 213 can be made lower, and the amplitude of the signal potential 212 and therefore the amplitude of the scanning potential 211 can be decreased. In other words, in the switching thin-film transistor 121 and the n-channel type current-thin-film transistor 122 , a decrease in drive voltage can be achieved without entailing any loss in image quality, abnormal operations, or a decrease in the frequency enabling them to operate.
[0054] Further, in the embodiment of the present invention, the signal potential 212 for the pixel to be in the display-state is lower than the counter potential 216 .
[0055] As stated above, in the period 221 in which the pixel is in the display-state, the ON-current of the n-channel type current-thin-film transistor 122 depends on the potential difference between the holding potential 213 and the common potential 214 , but not directly on the potential difference between the holding potential 213 and the counter potential 216 . Thus, the holding potential 213 , i.e., the signal potential 212 for the pixel to be in the display-state, can be made lower than the counter potential 216 , and therefore, the amplitude of the signal potential 212 and the amplitude of the scanning potential 211 can be decreased, while retaining a sufficiently large ON-current in the n-channel type current-thin-film transistor 122 . That is, in the switching thin-film transistor 121 and the n-channel type current-thin-film transistor 122 , a decrease in drive voltage can be accomplished without entailing any loss in image quality, abnormal operations, and a decrease in the frequency enabling them to operate.
[0056] Moreover, in this embodiment, the signal potential 212 for the pixel to be in the non-display-state is higher than the common potential 214 .
[0057] In the period 222 in which the pixel is in the non-display-state, when the signal potential 212 becomes slightly higher than the common potential 214 , the n-channel type current-thin-film transistor 122 is not completely turned OFF. However, the source/drain resistance of the n-channel type current-thin-film transistor 122 becomes considerably higher, as shown in FIG. 4 . Thus, the pixel potential 215 , which is determined by dividing the common potential 214 and the counter potential 216 by the values of the resistance of the n-channel type current-thin-film transistor 122 and the resistance of the forward oriented organic EL display element 131 , becomes a potential close to the counter potential 216 .
[0058] The voltage which is applied to the forward oriented organic EL display element 131 is the potential difference between the pixel potential 215 and the counter potential 216 . As shown in FIG. 5 , the forward oriented organic EL display element 131 is turned OFF when the voltage is not higher than a certain threshold voltage, when no current flows, so that the display device does not emit light. Namely, the utilization of a threshold potential of the forward oriented organic EL display element 131 makes it possible for the forward oriented organic EL display element 131 not to emit light, even if the signal potential 212 is slightly higher than the common potential 214 , and the n-channel type current-thin-film transistor 122 is not completely turned OFF.
[0059] Here, the amplitude of the signal potential 212 , and therefore the amplitude of the scanning potential 211 can be decreased by making the signal potential 212 for the pixel to be in the non-display state to be higher than the common potential 214 . In other words, with regard to the switching thin-film transistor 121 and the n-channel type current-thin-film transistor 122 , a decrease in drive potential can be accomplished without entailing any loss of image quality, abnormal operations , or a decrease in the frequency enabling them to operate.
[0060] The operation of an organic EL display device equipped with the thin-film transistors of this embodiment is not as simple as described above; it operates under a more complicated relationship between voltage and current. However, the description above holds true approximately and qualitatively.
Second Embodiment
[0061] FIG. 7 is an equivalent circuit diagram of an organic EL display device equipped with thin-film transistors, according to the second embodiment of the present invention. FIG. 8 is a drive voltage diagram of the organic EL display device with thin-film transistors, according to the second embodiment of the present invention. FIG. 9 is a current-voltage characteristic chart of the organic EL display device according to the second embodiment of the present invention.
[0062] In FIG. 7 , there are shown a pixel electrode formed of ITO 615 , an opposite electrode formed of Al 616 , a p-channel type current-thin-film transistor 622 , and an organic EL display device 631 (hereinafter referred to as “a reverse oriented organic EL display device”), which is caused to emit light by the current flowing to the Opposite electrode 616 from the pixel electrode 615 . Numeral 641 indicates the direction of the current of the organic EL display device. This direction is the reverse of that shown in FIG. 2 . Except for this, this embodiment is the same as the above first embodiment shown in FIG. 2 .
[0063] FIG. 8 is the same as FIG. 3 except that the level of each potential is different from that of FIG. 3 .
[0064] In FIG. 9 , a curve 81 indicates a current-voltage characteristic of a p-channel type current-thin-film transistor 622 as observed when the drain voltage is 4V. A curve 82 indicates a current-voltage characteristic of the p-channel type current-thin-film transistor 622 as observed when the drain voltage is 8V.
[0065] In FIG. 10 , a curve 9 indicates a current-voltage characteristic of a reverse oriented organic EL display device 631 .
[0066] The organic EL display device equipped with the thin-film transistors of this embodiment operates in the same way as that of the first embodiment, except that the potential relationship regarding the current-thin-film transistor is reversed due to the fact that the current-thin-film transistor is the p-channel type thin-film transistor 622 .
[0067] FIG. 11( a ) is a sectional view of an organic EL display device (1 pixel) equipped with the thin-film transistors, according to the second embodiment of the present invention. FIG. 11( b ) is a plan view of a thin-film transistor organic EL display device (1 pixel), according to the second embodiment of the present invention. The section taken along the line A-A′ of FIG. 11( a ) corresponds to the section taken along the line A-A′ of FIG. 11( b ).
[0068] FIG. 11( a ) is the same as FIG. 6( a ), except that it shows a hole injection layer 632 and an organic EL layer 633 .
[0069] The reverse oriented organic EL display device 631 is formed by means of the pixel electrode 615 formed of ITO, the opposite electrode 616 formed of Al, the hole injection layer 632 , and the organic EL layer 633 . In the reverse oriented organic EL display device 631 , the direction of current of the organic EL display device, indicated at 641 , can be set to the direction from the pixel electrode 615 formed of ITO to the opposite electrode 616 formed of Al.
[0070] In this embodiment, a common potential 714 is higher than a counter potential 716 . Further, the current-thin-film transistor is the p-channel type current-thin-film transistor 622 .
[0071] In this embodiment, a signal potential 712 for the pixel to be in the display-state is higher than the counter potential 716 .
[0072] Furthermore, in this embodiment, the signal potential 712 for the pixel to be in the non-display-state is lower than the common potential 714 .
[0073] All of the effects of the thin-film transistor organic EL display device of this embodiment are also the same as those of the first embodiment, except that the potential relationship regarding the current-thin-film transistor is reversed due to the fact that the current-thin-film transistor is the p-channel type thin-film transistor 622 .
[0074] In this embodiment, the current-thin-film transistor 122 is a p-channel type thin-film transistor. This arrangement enables the deterioration with time of the current-thin-film transistor 122 to significantly decrease. Furthermore, the arrangement adopting a p-channel type polysilicon thin-film transistor enables the deterioration with time of the current-thin-film transistor 122 to decrease even further.
[0075] FIG. 14 is a diagram of a process of producing the current-driven light-emitting display apparatus equipped with the thin-film transistors, according to the embodiment of the present invention described above.
[0076] As shown in FIG. 14( a ), an amorphous silicon layer with a thickness of 200 to 600 angstroms is deposited all over a substrate 1 , and the amorphous silicon layer is polycrystallized by laser annealing etc., to form a polycrystalline silicon layer. After this, patterning is performed on the polycrystalline silicon layer to form a silicon thin-film 421 , which serves as a source/drain channel region of the switching thin-film transistor 121 , a first electrode 423 of the storage capacitor 123 , and a silicon thin-film 422 , which serves as a source/drain channel region of the current-thin-film transistor 122 . Next, an insulation film 424 , which serves as a gate insulation film, is formed over the silicon thin-films 421 , 422 , and the first electrode 423 . Then, implantation of phosphorous (P) ions is selectively effected on the first electrode 423 to lower the resistance thereof. Next, as shown in FIG. 14( b ), gate electrodes 111 and 111 ′, which consist of TaN layers, are formed on the silicon thin-films 421 and 422 through the intermediation of the gate insulation film. Next, a resist mask 42 is formed on the silicon layer 422 serving as a current-thin-film transistor, and phosphorous (P) ions are implanted through self-alignment using the gate electrode as a mask to form an n-type source/drain region in the silicon layer 421 . Subsequently, as shown in FIG. 14( c ), a resist mask 412 ′ is formed on the first silicon layer 421 and the first electrode, and boron (B) is ion-implanted in the silicon layer 422 through self-alignment using the gate electrode 111 ′ as a mask to form a p-type source/drain region in the silicon layer 422 . In this way, an n-channel type impurity doping 411 allows the switching thin-film transistor 121 to be formed. At this time, the current-thin-film transistor 122 is protected by the resist mask 42 , so that the n-channel type impurity doping 411 is not performed. Then, a p-channel type impurity doping 412 allows the current-thin-film transistor 122 to be formed.
[0077] Further, though not illustrated, in a case in which a shift register of a drive circuit section which drives the switching transistor 121 , and a thin-film transistor constituting a sample hold circuit etc., are to be formed on the same substrate, it is possible to form them simultaneously in the same step of process as has been described above.
[0078] A second electrode 425 of the storage capacitor may be formed together with the gate electrodes 111 and 111 ′ simultaneously, either of the same or different materials.
[0079] As shown in FIG. 14( d ), after the formation of an inter-layer insulation film 43 and, then, contact holes, electrode layers 426 , 427 , 428 and 429 formed of aluminum, ITO or the like are formed.
[0080] Next, after an inter-layer insulation film 44 is formed and flattened, contact holes are formed; then, ITO 45 is formed with a thickness of 1000 to 2000 angstroms, preferably about 1600 angstroms, in such a manner that one electrode of the current-thin-film transistor is connected thereto. For each pixel region, bank layers 46 and 47 , which are not less than 2.0 μm in width, are defined. Next, an organic EL layer 48 is formed by an ink-jet method etc., in the region surrounded by the bank layers 46 and 47 . After the organic EL layer 48 is formed, an aluminum-lithium layer with a thickness of 6000 to 8000 angstroms is deposited as an opposite electrode 49 on the organic EL layer 48 . Between the organic EL layer 48 and the opposite electrode 49 , a hole injection layer may be disposed, as shown in FIG. 6( a ).
[0081] The process mentioned above enables an organic EL display device driven by means of a high-performance thin-film transistor to be formed. Since polysilicon is much higher in the mobility of carriers than amorphous-silicon, a rapid operation is possible.
[0082] In particular, in this embodiment, when the p-type current-thin-film transistor 122 and the n-type switching thin-film transistor 121 are formed, it is possible to form both of n-type and p-type thin-film transistors, which are complementary type thin-film transistors constituting a shift register of a drive circuit, a sample hold circuit and the like, being simultaneously formed in the above mentioned embodiment. The arrangement makes it possible to realize a construction capable of decreasing the deterioration with time of the current-thin-film transistor 122 , without increasing the number of production steps.
[0083] As described above, in the first embodiment, an n-channel type current-thin-film transistor is used, and, in the second embodiment, a p-channel type current-thin-film transistor is used. Here, the deterioration with time of p-channel and n-channel type thin-film transistors will be examined.
[0084] FIG. 12 and FIG. 13 are charts showing respectively the deterioration with time of n-channel type and p-channel type thin-film transistors, especially of polysilicon thin-film transistors, under equivalent voltage application conditions. Numerals 511 and 512 of FIG. 12 indicate the conductivity characteristics of an n-channel type thin-film transistor, in the cases in which Vd=4V and in which Vd=8V, respectively, before voltage application. Numerals 521 and 522 indicate the conductivity characteristics of an n-channel type thin-film transistor, in the cases in which Vg=0V and Vd=15V and in which Vd=4V and Vd=8V, respectively, after voltage application of approximately 1000 seconds. Numerals 811 and 812 of FIG. 13 indicate the conductivity characteristics of a p-channel type thin-film transistor in the cases in which Vd=4V, and in which Vd=8V, respectively, before voltage application. Numerals 821 and 822 indicate the conductivity characteristics of a p-channel type thin-film transistor in the cases in which Vg=0V and Vd=15V, and in which Vd=4V and Vd=8V, respectively, after voltage application for approximately 1000 seconds. It can be seen that in the p-channel type thin-film transistor, the decrease of ON-current and the increase of OFF-current are smaller than in the n-channel type.
[0085] Taking into consideration the difference in the deterioration-with-time characteristic between the p-type and the n-type thin-film transistors as shown in FIG. 12 and FIG. 13 respectively, at least either a switching thin-film transistor or a current-thin-film transistor is formed of a p-channel type thin-film transistor, especially a p-type polysilicon thin-film transistor, whereby the deterioration with time can be suppressed. Further, by forming the switching thin-film transistor as well as the current-thin-film transistor of a p-type thin-film transistor, it is possible to maintain the characteristics of the display device.
[0086] While an organic EL display device is used as the luminescent device in the embodiment described above, this should not be construed restrictively, yet, it is needless to say that an inorganic EL display device or other current-driven luminescent devices are also applicable.
INDUSTRIAL APPLICABILITY
[0087] The display apparatus according to the present invention can be used as a display apparatus equipped with a current-driven luminescent device such as an organic EL display device or an inorganic EL display device, and a switching device to drive the luminescent device, such as a thin-film transistor. | An electroluminescent device including a substrate, a transistor disposed above the substrate, the transistor including a gate electrode, a silicon film opposing the gate electrode, and a gate insulating film between the gate electrode and the silicon film. The electroluminescent device including a first interlayer insulation film covering the transistor, a second interlayer insulation film disposed above the first interlayer insulation film, and a pixel electrode disposed above the second interlayer insulation film and electrically connected to the transistor. The electroluminescent device including an organic EL layer disposed between the pixel electrode and a counter electrode, and a capacitor including a first electrode formed by the same material as the silicon film and a second electrode formed by the same material as the gate electrode. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a soft-stop device and power converter, and more particularly, to a soft-stop device and power converter capable of directly sampling an output voltage of the power converter when shut down, and allowing the output voltage fully discharged.
[0003] 2. Description of the Prior Art
[0004] A power converter is an important part of an electronic device, which can convert an input voltage to an output voltage having different voltage levels. In general, the power converter requires to ensure the output voltage returned to zero when shut down; otherwise, the power converter may not be activated from zero voltage level due to the residual output voltage when the power converter is turned on next time, and may cause circuit damaged or a countercurrent status of an inductor current flowing to a voltage input terminal.
[0005] Please refer to FIG. 1 , which is a schematic diagram of a conventional power converter 10 . The power converter 10 is a switching-mode buck converter, which can convert an input voltage VIN to an output voltage VOUT of lower level. The power converter 10 includes a control module 100 , a power stage circuit 102 and a feedback circuit 104 . The control module 100 compares a feedback signal VFB generated by the feedback circuit 104 and a reference voltage VRF, and generates driving signals VDRV and VDRV_B reversing to each other to the power stage circuit 102 accordingly. The power stage circuit 102 is composed of an upper gate switch N 1 , a lower gate switch N 2 , an inductor L and a capacitor C, and switches a connection between the input voltage VIN or a grounding terminal and the inductor L according to the driving signals VDRV and VDRV_B, so as to convert the input voltage VIN to the suitable output voltage VOUT via inductor-capacitor effect. The feedback circuit 104 is composed of resistors R 1 and R 2 , which divides the output voltage VOUT via a voltage-dividing method, and deriving the feedback signal VFB. In other words, VFB=VOUT×R 2 /(R 1 +R 2 ).
[0006] When shut down, the power converter 10 can set the reference voltage VRF to be zero, and the control module 100 may control the power stage circuit 102 according to a gap between the feedback signal VFB and the reference voltage VRF, to reduce the output voltage VOUT. However, the feedback signal VFB can not accurately correspond to a status of the output voltage VOUT. When a voltage-dividing ratio between the feedback signal VFB and the output voltage VOUT is too high, an offset between the feedback signal VFB and the reference voltage VRF may cause the output voltage VOUT to have residual voltage and can not be completely discharged to zero when the power converter 10 is shut down. Assuming the voltage-dividing ratio between the feedback signal VFB and the voltage VOUT is VFB: VOUT=1:5, and if the offset (e.g. 100 mV) between the feedback signal VFB and the output voltage VOUT occurs, it may cause the output voltage VOUT to have a proportional residual voltage (e.g. 500 mV) when shut down, and further worsen the voltage residual status when the output voltage VOUT is higher. When the power converter 10 is booted and the upper gate switch N 1 is turned on next time, the output voltage VOUT remained on the capacitor C may cause a backflow current generated by the inductor L flowing to the voltage input terminal.
[0007] Therefore, it is a common goal in the industry to improve the voltage residual status when the power converter is shut down.
SUMMARY OF THE INVENTION
[0008] It is therefore an objective of the present invention to provide a soft-stop device and related power converter thereof, for returning an output voltage of the power converter to zero when shut down.
[0009] The present invention discloses a soft-stop device for a power converter utilized for converting an input voltage to an output voltage. The soft-stop device includes a first signal terminal, for receiving a first signal corresponding to the output voltage; a second signal terminal, for receiving a shutdown signal for turning off the power converter; a discharging switch, coupled between the first signal terminal and a grounding terminal, for controlling an electrical connection between the first signal terminal and the grounding terminal according to a control signal; a sample-and-hold unit, coupled to the first signal terminal and the second signal terminal, for sampling the first signal received by the first signal terminal when the shutdown signal is received by the second signal terminal, to generate a shutdown reference voltage; and a shutdown control unit, for generating the control signal according to the first signal and the shutdown reference voltage.
[0010] The present invention further discloses a power converter, for converting an input voltage to an output voltage. The power converter includes a control module, for providing a control signal; a power stage circuit, for receiving the input voltage, and providing the output voltage according to the control signal; and a soft-stop device, including a first signal terminal, for receiving a first signal corresponding to the output voltage; a second signal terminal, for receiving a shutdown signal for turning off the power converter; a discharging switch, coupled between the first signal terminal and a grounding terminal, for controlling an electrical connection between the first signal terminal and the grounding terminal according to a control signal; a sample-and-hold unit, coupled to the first signal terminal and the second signal terminal, for sampling the first signal received by the first signal terminal when the shutdown signal is received by the second signal terminal, to generate a shutdown reference voltage; and a shutdown control unit, for generating the control signal according to the first signal and the shutdown reference voltage.
[0011] These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic diagram of a conventional power converter.
[0013] FIG. 2 is a schematic diagram of a power converter according to an embodiment of the present invention.
[0014] FIG. 3 is a detailed schematic diagram of the power converter shown in FIG. 1 .
[0015] FIG. 4 is a timing schematic diagram of related signals of a soft-stop circuit operation of the power converter shown in FIG. 1 .
[0016] FIG. 5 is a schematic diagram of a power converter according to an embodiment of the present invention.
[0017] FIG. 6A and FIG. 6B are schematic diagrams of power converters according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0018] Please refer to FIG. 2 , which is a schematic diagram of a power converter 20 according to an embodiment of the present invention. The power converter 20 is a switching-mode buck converter, which can convert an input voltage VIN to an output voltage VOUT of lower level. The power converter 20 comprises a control module 200 , a power stage circuit 202 , a feedback circuit 204 and a soft-stop circuit 206 . The structure and operations of the control module 200 , the power stage circuit 202 and the feedback circuit 204 are similar to those of the control module 100 , the power stage circuit 102 and the feedback circuit 104 shown in FIG. 1 , and the same components are denoted by the same symbols. Difference between the power converter 20 and the power converter 10 is that the power converter 20 further adds a soft-stop circuit 206 , which can conduct the lower gate switch N 2 according to the output voltage VOUT when shut down, to discharge the residual output voltage VOUT to zero, thereby avoiding circuit damaged or a countercurrent status of an inductor current flowing to a voltage input terminal.
[0019] In detail, the soft-stop circuit 206 can turn off the power converter 20 according to a shutdown signal SD. When the shutdown signal SD does not indicate shut down, the soft-stop circuit 206 is disabled, and the control module 200 is enabled, allowing the power converter 20 to perform normal voltage converting operations. When the shutdown signal SD indicates shut down, the control module 200 may be disabled, and the soft-stop circuit 206 is enabled, allowing the power converter 20 to stop the voltage converting operations, and perform soft-stop mechanism. At this moment, the soft-stop circuit 206 can control the lower gate switch N 2 to be turned on according to a phase signal VP corresponding to the output voltage VOUT, and discharging the residual output voltage VOUT to the ground through a path of a discharge current ID via a negative feedback mechanism. In the prior art, the power converter 10 controls discharging mechanism during shut down according to the feedback signal VFB derived from dividing the output voltage VOUT, which causes residual voltage issue. In comparison, the power converter 20 directly utilizes the phase signal VP corresponding to the output voltage VOUT, and does not perform voltage dividing, thereby ensuring the output voltage VOUT to be fully discharged when shut down.
[0020] Furthermore, please refer to FIG. 3 , which is a schematic diagram of an embodiment of the soft-stop circuit 206 . In this embodiment, the soft-stop circuit 206 comprises a sample-and-hold unit 300 , a shutdown control unit 302 and a switching unit 303 . The switching unit 303 is formed by switches 316 , 318 and 320 , which control connections between the soft-stop circuit 206 , the control module 200 and the power stage circuit 202 according to the shutdown signal SD (or an inverse signal SDB of the shutdown signal SD). The sample-and-hold unit 300 comprises a sample switch 304 and a voltage storage unit 306 , which samples the phase signal VP as a shutdown reference voltage VREF when the shutdown signal SD indicates shut down (e.g. SD=1). The shutdown control unit 302 comprises a reference voltage discharging switch 308 , a current source 310 and an operational amplifier 312 , which discharges the shutdown reference voltage VREF, and compares the shutdown reference voltage VREF with the phase signal VP to generate a control signal CON, when the shutdown signal SD indicates shut down.
[0021] In detail, when the power converter 20 is in a normal converting operation (e.g. SD=0), the switching unit 303 conducts switches 318 and 320 , and cuts off the switch 316 ; thus, the control module 200 is enabled, and the soft-stop circuit 206 is disabled. When the power converter 20 is shut down (SD=1), the switching unit 303 cuts off the switches 318 and 320 , and conducts the switch 316 ; thus, the control module 200 is disabled, and the soft-stop circuit 206 is enabled. At this moment, the sample-and-hold unit 300 cuts off the sample switch 304 , to sample the phase signal VP at the moment of shut down as the shutdown reference voltage VREF, and store the sampled phase signal VP in a capacitor 314 of the voltage storage unit 306 . Then, the shutdown control unit 302 conducts the reference voltage discharge switch 308 , to discharge the shutdown reference voltage VREF via a constant current I of the current source 310 , such that the shutdown reference voltage VREF linearly falls to a grounding terminal voltage level. The control signal CON generated by the operational amplifier 312 can conduct the lower gate switch N 2 , and the phase signal VP is discharged to the ground through the path of the discharge current ID. Therefore, the operational amplifier 312 can force the phase signal VP of a positive input terminal of the operational amplifier 312 to vary with the shutdown reference voltage VREF of a negative input terminal via the negative feedback mechanism, leading the phase signal VP to follow the shutdown reference voltage VREF and linearly decrease to zero. In addition, when the power converter 20 stops converting operations, the switching unit 303 may disable the control module 200 , and the upper gate switch N 1 and the lower gate switch N 2 of the power stage circuit 202 are in an OFF state; therefore, the inductor L equals a conducting wire at this moment, and the phase signal VP equals the output signal VOUT accordingly. Therefore, when the phase signal VP follows the shutdown reference voltage VREF and is linearly reduced to zero, the output voltage VOUT can also be linearly reduced to zero, and have no residual voltage.
[0022] Please refer to FIG. 4 , which is a timing schematic diagram of related signals when operating the soft-stop circuit 206 shown in FIG. 3 . When the power converter 20 is not shut down (i.e. shutdown signal SD=0) and in the normal converting operation, waveforms of the output voltage VOUT, the phase signal VP and the shutdown reference voltage VREF are as shown in FIG. 4 . When the power converter 20 is shut down (i.e. the shutdown signal SD=1), the phase signal VP stops fluctuation and equals the output voltage VOUT, and the sample-and-hold unit 300 samples and stores the output voltage VOUT as the shutdown reference voltage VREF at this moment. Subsequently, the reference voltage discharge switch 308 is conducted, and the current source 310 starts to discharge the shutdown reference voltage VREF stored in the sample-and-hold unit 300 . Assuming a capacitor value of the capacitor 314 is C, and a current of the current source 310 is the constant current I, and a voltage of the output voltage VOUT at the moment of shut down is VOUT_SD, the shutdown reference voltage VREF is linearly reduced to 0 after a discharge time T. The discharge time T can be expressed as T=C*VOUT_SD/I.
[0023] Therefore, the soft-stop circuit 206 of FIG. 3 can directly sample the output voltage VOUT of the power converter 20 at the moment of shut down via the sample-and-hold unit 300 , and by utilizing the shutdown control unit 302 , the residual output voltage can be discharged to zero via the negative feedback mechanism when shut down. Note that, the soft-stop circuit 206 as shown in FIG. 3 is adapted to switching-mode buck applications, and the lower gate switch N 2 is as a discharging switch when shut down. However, those skilled in the art may proper adjust the soft-stop circuit 206 , to meet requirements of different applications. For example, in another embodiment, the soft-stop circuit 206 can remove the switching module 303 . Furthermore, when the upper-lower gate structure is not applied in a power converter, the soft-stop circuit 206 has to add the discharging switch.
[0024] For example, please refer to FIG. 5 , FIG. 6A and FIG. 6B , which are schematic diagrams of properly modifying and applying the soft-stop circuit 206 to different power converters according to different embodiments of the present invention. FIG. 5 is a schematic diagram of a power converter 50 according to an embodiment of the present invention. The power converter 50 comprises a control module 500 , a power stage circuit 502 , a feedback circuit 504 and a soft-stop circuit 506 . The power converter 50 is a switching-mode boost converter, which can convert the input voltage VIN to the output voltage VOUT of higher level, and operations are well known by those skilled in the art, and are not narrated hereinafter. A structure of the soft-stop circuit 506 is similar to that of the soft-stop circuit 206 of FIG. 3 , but the soft-stop circuit 506 does not include the switching module 303 , and thus the same elements are denoted by the same symbols. In detail, the soft-stop circuit 506 comprises a discharging switch ND and the sample-and-hold unit 300 and the shutdown control unit 302 shown in FIG. 3 . The difference between the soft-stop circuit 506 and the soft-stop circuit 206 shown in FIG. 2 is that since in the power converter 50 , the inductor L included in the power-stage circuit 502 is located at an input voltage terminal rather than an output voltage terminal, the soft-stop circuit 506 can directly sample the voltage of the output capacitor C to obtain the output voltage VOUT without sampling the phase signal VP corresponding to the output voltage VOUT. In addition, since the power stage circuit 502 of the power converter 50 lacks a structure of the lower gate switch N 2 included in the power converter 20 , and needs to add the discharge switch ND, to discharge the output voltage VOUT remained in the output capacitor C to the ground via the path of the discharge current ID when shut down.
[0025] Please continue to refer to FIG. 6A and FIG. 6B . FIG. 6A is a schematic diagram of a power converter 60 according to another embodiment of the present invention. The power converter 60 comprises a control module 600 , a power stage circuit 602 and a soft-stop circuit 604 . The power converter 60 is a low-dropout (LDO) linear power converter, which can convert the input voltage VIN to the output voltage VOUT of lower level, and operations are well known by those skilled in the art, and are not narrated hereinafter. The soft-stop circuit 604 comprises the discharging switch ND and the sample-and-hold unit 300 and the shutdown control unit 302 shown in FIG. 3 . The power converter 60 is not a switching-mode power converter, and lacks the inductor L included in the power converter 20 . Therefore, the difference between the soft-stop circuit 604 and the soft-stop circuit 206 is that the soft-stop circuit 604 can directly sample the output voltage VOUT of the output capacitor C. In addition, the power stage circuit 602 lacks the structure of the lower gate switch N 2 included in the power converter 20 , and thus the soft-stop circuit 604 needs to add the discharge switch ND, to discharge the output voltage VOUT remained in the output capacitor C to the ground via the path of the discharge current ID when shut down. On the other hand, in another embodiment, the power transistor N 1 of the power stage circuit 602 of the power converter 60 can also be disposed inside a control chip 620 including the control module 600 , such as a power converter 62 as shown in FIG. 6B .
[0026] Note that, the spirit of the present invention is to directly sample the output voltage (or the signal corresponding to the output voltage) rather than only sample the signal after dividing the voltage of the output voltage as the reference voltage. Therefore, using the negative feedback mechanism, the residual output voltage can be discharged to zero when shut down, and may not generate a residual voltage related to a voltage-dividing ratio. Those skilled in the art may make alterations or modifications according to different applications. For example, the soft-stop circuit of the present invention is not limited for the switching-mode power converter or the linear power converter, and can be utilized for different devices, such as a power converter, a voltage regulator, and a power generator, etc. or any other applications requiring the output voltage to be returned to zero at each restart. In addition, as to sampling the output terminal to generate the reference voltage required by the shutdown circuit, it is preferable to directly sample the output voltage or sample a signal corresponding to the output voltage. In addition, the current source I of the shutdown control unit 302 and the value of the capacitor C of the sample-and-hold unit 300 both are determined based on system requirements, to fall the output voltage to zero with different speeds after shut down. The output voltage is not limited to be linearly reduced when shut down, and can also be reduced along a curve, as long as the output voltage can be gradually reduced and have no residual voltage after shut down.
[0027] To sum up, apart from sampling the signal generated by dividing the output voltage as the reference voltage in the prior art, the soft-stop circuit of the present invention directly samples the output voltage (or the signal corresponding to the output voltage). Therefore, when shut down, the power converter can discharge the residual output voltage to zero via the negative feedback, and may not generate the residual output voltage when the voltage-dividing ratio is higher.
[0028] Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims. | A soft-stop device for a power converter includes a first signal terminal for receiving a first signal corresponding to an output voltage of the power converter; a second signal terminal for receiving a shutdown signal for turning off the power converter; a discharge switch, coupled between the first signal terminal and a grounding terminal, for controlling an electrical connection between the first signal terminal and the grounding terminal according to a control signal; a sample-and-hold unit, for sampling the first signal received by the first signal terminal when the shutdown signal is received by the second signal terminal, to generate a shutdown reference voltage; and a shutdown control unit, for generating the control signal according to the first signal and the shutdown reference voltage. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application is a continuation-in-part (CIP) application of application Ser. No. 08/335,123 to Hsieh entitled "A Circuit Arrangement for a Sanitary Apparatus" that was filed in the U.S. Patent and Trademark Office on Nov. 7, 1994, now abandoned.
FIELD OF THE INVENTION
The present invention relates to a circuit arrangement for a sanitary apparatus, and particularly to an electronic circuit for controlling sanitary fittings in a non-contacting manner.
RELATED PRIOR ARTS
U.S. Pat. No. 5,251,872, entitled Automatic Cleaner for Male Urinal discloses a device adapted for automatically cleaning a male urinal. The device includes a pyroelectric sensor for detecting the proximity of the human body, an infrared ray emitting circuit for emitting infrared rays to a human body, and an infrared ray receiving circuit detecting infrared rays reflected by the human body. The device disclosed in U.S. Pat. No. 5,251,872 does not directly take advantage of the pyroelectric sensor to activate the circuits thereof and additionally applies an infrared ray emitting circuit and an infrared ray receiving circuit which obviously increases the cost of the device and additionally consumes a significant power supplied by a battery.
U.S. Pat. No. 4,941,219, entitled Body Heat Responsive Valve Control Apparatus relates to a low battery energized passive detection system responsive to radiated body heat for operating fluid flow valves. The disclosed apparatus applies a pyroelectric detector for detecting the presence of body heat within a defined detection field and producing an output signal in response to the detection and a plurality of operational amplifiers for performing the functions of comparing and amplifying. Due to the utilization of valves and operational amplifiers, this apparatus will have a slower response to the variation of the fluid flow and this apparatus is also easily influenced by the variation of the supplied power. Further, as this apparatus uses operational amplifiers, it will consume a lot of power and the battery will not be efficiently used.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a circuit arrangement which prevents automated faucet from wasting water and decreases the risk of electric shock.
Another object of the present invention is to provide a circuit arrangement which allows the automated faucet to be installed conveniently without the interconnection to an alternating current power.
According to the present invention, an electronic circuit includes a pyroelectric sensing circuit for detecting the approach of hands of a user, a microprocessor for analyzing a signal from the pyroelectric sensing circuit and outputting a signal to a driving circuit, a voltage source for supplying the power required by the electronic circuit, an oscillator for providing a signal to the driving circuit and the microprocessor, and a manual operative circuit is connected to the driving circuit for activating the driving circuit.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the circuit arrangement of the present invention;
FIG. 2 is a circuit diagram of the present invention; and
FIG. 3 is a diagram showing operation waveforms of a respective signal in a microprocessor of FIG. 1 and a corresponding digital sequence for the signal.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a pyroelectric sensing circuit 20 detects the presence of body heat within a defined detection field, the pyroelectric sensing circuit 20 then sends a signal to a microprocessor 10, the microprocessor 10 will analyze the signal from the pyroelectric sensing circuit, if the signal received by the microprocessor 10 is judged as a result of body heat, the microprocessor 10 will send a triggering signal to a driving circuit 70 which then outputs a signal to actuate a motor-operated control valve in a faucet. A manual activating circuit 40 is connected to the driving circuit 70 for activation thereof when required. An oscillator 30 is connected to the microprocessor 10 for providing an oscillating signal thereto. The oscillator 30 is further connected the driving circuit 70 for providing an oscillating signal thereto. A power circuit 50 is provided for supplying the power needed by this circuit.
As shown in FIG. 2, a pyroelectric sensing circuit 20 is composed of a pyroelectric sensor 21 and a plurality of electronic components for detecting the proximity of the human body. An output of the pyroelectric sensing circuit 20 is connected to a microprocessor 10. An output of the microprocessor 10 is connected to an emitter of a transistor 31. An oscillator 30 composed of two NAND gates, a capacitor and two resistors for outputting an oscillating signal is connected to a base of the transistor 31.
A collector of the transistor 31 is connected to a driving circuit 70 composed of two flip-flops 71,72, two transistors 73, 74, a motor-operated control valve 75, and an ON/OFF switch 751. The collector of the transistor 31 is connected to a clock input of the flip-flop 71. A non-inverted output of the flip-flop 71 is connected to a base of the transistor 73 via a normally closed contact of the ON/OFF switch 751. The ON/OFF switch 751 is controlled by the motor-operated control valve 75 and they are connected by a method within the skill of those skilled in the art which causes the ON/OFF switch 751 to activate in a sequence as later mentioned. An inverted output of the flip-flop 71 is connected to a normally open contact of the ON/OFF switch 751.
The motor-operated control valve 75 is connected to a collector of the transistor 73. The non-inverted output of the flip-flop 71 is further connected to a clock input of the flip-flop 72, the inverted output of the flip-flop 72 is connected to a clear terminal of the flip-flop 71 via the transistor 74 for clearing the states of the flip-flop 71.
If the presence of a body heat is detected by the pyroelectric sensing circuit 20, the output of the microprocessor 10 will send a trigger signal of low voltage (e.g. ground potential) to the emitter of the transistor 31. The transistor 31 then outputs a square wave signal having a same frequency as that of the oscillating signal from the oscillator 30 to the clock input of the flip-flop 71 which causes the non-inverted output of the flip-flop 71 to become high, then the transistor 73 is turned on, the motor-operated control valve 75 will start to open. When the valve is at a fully open position, the ON/OFF switch 751 will be actuated, the transistor 73 will be turned off, the motor-operated control valve 75 will be stopped. Thus, the water will continuously flow.
When the hands of the user leave the detection field, the output of the microprocessor 10 will be high, the square wave signal input to the flip-flop 71 is stopped. The inverted output of the flip-flop 71 will become high, then the transistor 73 and the motor-operated control valve 75 are activated and the valve 75 will start to close. If the motor-operated control valve 75 is at fully closed position, the ON/OFF switch 751 is actuated and returns to its initial state. The water flow is stopped.
A manual activating circuit 40 is composed of a NAND gate 42 with two inputs, a capacitor 43, a resistor 44, and a toggling switch 41. A first input of the NAND gate 42 is connected to the base of the transistor 31 and a second input is connected to a positive voltage source V+ via the toggling switch 41. The output of the NAND gate 42 is connected to the clock input of the flip-flop 71 via a diode 45. The capacitor 43 and the resistor 44 are connected between the second input of the NAND gate 42 and the ground for composing a delay function such as ten seconds, that is, the driving circuit 70 will be activated for ten seconds after which the circuit will be disconnected.
As shown in the FIG. 2, a power circuit 50 is composed of a plurality of battery cells 60 connected in series, two transistors in a Darlington connection, a Zener diode, two capacitors, and a resistor for supplying a positive voltage V+ as mentioned above.
Referring to FIG. 3A, an output signal of the pyroelectric sensing circuit 20 is shown. This output signal is then transmitted into the microprocessor 10 for further processing. In FIG. 3A, a pulse P1 corresponds to a pulse which has detected a presence of body heat of a user and a pulse P2 corresponds to a pulse which does not detect the presence of the body heat. The signal as shown in FIG. 3A is then sampled and held with a sampling frequency of 400 Hz to derive a resultant signal as shown in FIG. 3B. The sampled and held signal shown in FIG. 3B is then compared with a predetermined reference level Vref (shown in a dashed line), then the waveform having a greater level than the reference level Vref is output, thus, a resultant signal is shown in FIG. 3C which has a corresponding binary sequence as shown in FIG. 3D. The microprocessor 10 then reads the sequence in bytes (eight bits) and executes an exclusive OR operation between two sequential bytes (i.e., a current byte and a preceding byte) to determine whether the pyroelectric sensing circuit 20 detects the presence of the body heat in a detection field. If the resultant byte has three or more "1" bits (includes three "1" bits), the microprocessor 10 will regard as a logic signal of "High" (referred to "H"). If the resultant byte has only two "1" bits or less, the microprocessor 10 will deem the resultant signal as a logic signal of "Low" (Referred to "L"). If the logic "H" signals do not continuously appear, i.e., only appear for 20 milliseconds, the signals received by the pyroelectric sensing circuit 20 will be judged as environmental noises and the motor 75 in FIG. 2 will not be activated. If the logic signal remains "H" for at least 40 milliseconds, the triggering signal will be output to the driving circuit 70 to activate the motor 75.
Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. | A circuit arrangement for controlling a sanitary device in a non-contact manner includes a pyroelectric sensing circuit for detecting a temperature in a predetermined location and outputting a signal, a microprocessor for receiving a signal from the pyroelectric sensing circuit and outputting a triggering signal when the signal received by the microprocessor is judged as a result of body heat, a driving circuit for receiving the triggering signal and actuating a motor-operated control valve. | 4 |
FIELD OF THE INVENTION
The present invention relates to a hammer drill, more particularly to a hammer drill of the "hole bottom" type, i.e., one intended to work on the actual bottom of the hole which is being drilled.
Appliances of this kind usually work with compressed air and are disposed at the end of a string of pipes which serve simultaneously for transmitting the operating compressed air to them and for the thrust and general rotary movement for regulating the action of the drill bit at the bottom of the hole.
BACKGROUND OF THE INVENTION
Pneumatic hammers intended to work at the bottom of the hole generally comprise a tubular body supplied with compressed air, a distribution mechanism, a percussion piston, and a bit receiving the blows of the percussion piston in order to transmit them to the rock. The percussion piston is movable in a cylinder formed by a liner, and longitudinal passages are provided between the liner and the inside wall of the hammer body for the supply of the compressed air acting on the piston, while other passages serve to exhaust the air after it has acted on one face or the other of the percussion piston.
In order to enable the percussion piston to apply sufficient striking force to the bit, and consequently to the rock which is being drilled, use is made of compressed air under high pressure, for example 20 to 25 bars. The consumption, which may be of the order of 10 to 15 cubic meters at S.T.P., for example, therefore entails the use of high-output, high-pressure compressors, i.e., heavy and bulky equipment. Moreover, this equipment is expensive, both with regard to initial cost and immobilization of capital and with regard to operating costs, because of the considerable consumption of energy.
SUMMARY OF THE INVENTION
The present invention makes it possible to reduce these costs substantially, and at the same time to increase drilling power and reduce energy consumption.
The invention is concerned with a hammer drill of the "hole bottom" type, which comprises a tubular body supplied with compressed air and carrying a drill bit, and in which a liner forms a cylinder in which a percussion piston is caused to perform a reciprocating movement by a compressed air distribution mechanism, thus moving alternately into the lower chamber of the cylinder, into which the shank of the bit projects, and into the upper chamber of the cylinder opposite the bit, and at the same time alternately exhausting the upper chamber and the lower chamber.
According to the invention, the hammer drill also includes a device for injecting gas oil into the upper chamber of the cylinder, with a mechanism for triggering the injection in the rising phase of the piston corresponding to additional compression of the feed air in the upper chamber, so as to bring about the internal combustion of the air-gas oil mixture and thus violently project the piston towards the bit.
In one particular embodiment of the invention, the mechanism for triggering the injection of gas oil is controlled by the deformation of an elastic diaphragm forming a wall of an auxiliary chamber supplied with compressed air at the same time as the upper chamber of the cylinder.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood by reference to one particular embodiment given by way of example and illustrated in the accompanying drawings.
FIG. 1 is a general view, in two parts and in section in an axial plane, of a hammer drill constructed in accordance with the invention.
FIG. 2 is similar to FIG. 1, but shows only the central portion of the hammer drill, in section in another axial plane.
FIGS. 3 to 6 are partial views showing the successive positions of the percussion piston in the course of an operating cycle.
FIGS. 7 and 8 show on a larger scale the operation of the gas oil injection device, in the position, of rest and the injection position respectively.
DETAILED DESCRIPTION
Referring firstly to both parts of FIG. 1, it will be seen that the main body 1 of the hammer drill is screwed at the bottom to an end piece 2 in which slides the splined shank of the drill bit 3. The shank of the bit is rotationally fixed relative to the body, and limited in respect of axial displacement, by a tangential key 4 bearing against a recess 5 in the shank.
A liner 7 inside the body 1 extends over almost the entire length of the latter. It forms two oppositely disposed shells, each open towards one end of the body, which are separated by a solid core 6. At the bottom, the liner 7 bears against a spacer ring 8 of generally conical shape, in which radial apertures 9 are formed and which in turn bears against the end piece 2. The top of the liner 7 abuts against the connector 13 screwed on the body 1. At its other end, the connector 13 receives the usual members making the connection to the pipes and rods feeding and operating the hammer drill.
The part 15, which transmits the thrust to the hammer drill, forms an annular duct 16 around a central pipe 17. The part 15, which fits over the end of the connector 13, is screwed on a hollow piston 18, whose splined bottom portion 19 permits axial sliding, without rotation, in a matching splined part inside the connector 13; the assembly 15-18 can thus slide on the connector 13. The vertical thrust on the hammer drill is therefore transmitted to the connector 13 through the compression of the pads 20, and the rotary movement through the splines 19. When, on the other hand, it is desired to raise the hammer drill, for example in order to pull it up, the lifting force is transmitted to the connector 13 by the splines of the piston 18, which rise until they strike against the shoulder 21 terminating the splines of the connector.
The bottom of the piston 18 is fastened by radial ribs 23 to a tubular member 24 screwed into a piston 25. The piston 25 is thus fastened to the piston 18 and can therefore move inside the liner 7 or inside the bore extending the latter in the connector 13, depending on whether the hammer drill is being pushed down or raised. Ducts 26 extend through the piston 25.
The end of the central pipe 17 is engaged in the central bore of the tubular member. A its other end the central bore receives a hollow needle 28, which ends in an atomizer 29 locked in the central core 6 of the liner 7. The arrangement of the internal passages in the needle 28 will be described later on in connection with FIG. 7. The fixed pipe 17 and the fixed needle 28 are thus in communication through the chamber 30 inside the member 24. When a thrust is applied to the hammer drill during the raising of the latter, the member 24 slides on the pipe 17 and on the needle 28, and the fluidtightness of the intermediate chamber 30 is maintained by the seals 31.
The fixed needle 28 passes through the block 33, which is also fixed in the upper liner 7. The block 33 contains a piston type distributor device 34, which in this figure is shown only in silhouette in dot-dash lines, and which will be described in greater detail later on in connection with FIG. 7. This device is controlled by the displacement of a core 35 which forms the center of a flexible diaphragm fixed by its periphery in the block 33.
The inner surface of the lower part of the liner 7 serves as a guide for the sliding percussion piston 38, which is adapted to move freely between a lower position, as shown in FIG. 1 in which it is in contact with the end of the shank of the bit, and an upper position, as will be seen later on in the course of the description of the operation of the apparatus. Externally, the percussion piston 38 is provided with a circular groove 39. At the top it is provided with sealing rings 40.
The outer surface of the liner 7 has five series of longitudinal grooves; in order to simplify the drawings, only a single groove of each type has been shown in FIGS. 1 and 2. A first series of grooves 41 brings into communication the apertures 42, which have their outlets between the block 33 and the piston 25, and the apertures 43 which have their outlets in a central position in the lower chamber formed by the liner 7.
A second series of grooves 44 brings into communication the apertures 45 and 46, both of which have their outlets inside the lower portion of the liner 7. A third series of grooves 48 leads to the annular chamber 49 surrounding the bottom ring 8; the apertures 50 and 51 pass through the wall of the lower part of the liner 7 and lead out into these grooves 48; the apertures 52, which pass through the upper wall of the liner 7, are normally closed when the piston 25 is in the lower position, as shown in the drawing. These apertures 52 are uncovered when the piston 25 is in the upper position corresponding to the raising of the hammer drill.
A fourth series of grooves 54 brings into communication the apertures 55 and 56, which lead respectively into the lower chamber 71 of the liner 7 and into the upper chamber 72 thereof, between the core 6 and the diaphragm 36. The groove 54 also has an aperture 57 of small dimensions, which leads into the upper part of the liner 7.
It will be noted that the chamber 49 around the ring 8 is in communication with the outside of the hammer drill through the ducts 9, through the clearances between the splines of the drill bit and the matching grooves in the end piece 2, and through the chamber 59 which is in communication with the outside by way of the exhaust ducts 60.
Finally, the fifth series of grooves 58 (FIG. 2) leads, like the grooves 48, into the chamber 49 and is therefore likewise in communication with the outside. At the top, the grooves 58 are each in communication through an aperture 74 with a calibrated passage 75 drilled in the part 25 and leading into one of the passages 26.
Reference can now be made to FIG. 7 in connection with additional details of the needle 28 and distributor 34. The latter is composed of an axial space 62 in which slides an annular piston 63 surrounding the needle 28. The piston 63 has an internal recess 64 which is in communication with the space 62 via ducts 65. In the needle 28 a duct 66 leads on the one hand into the chamber 30 and on the other hand into the periphery of the needle at the level of the recess 64 in the piston 63. Another duct 67 starts from the periphery of the needle at the level of the top part of the space 62, and leads to the aperture of the atomizer 29. A preset valve 68 is disposed on the duct 67.
The central pipe 17 is supplied from the surface with gas oil which passes via the chamber 30, the duct 66, the chamber 64, and the ducts 65 to fill the chamber 62 of the distributor. The gas oil also passes into the duct 67, but in the normal position, which is shown for example in FIGS. 1 and 7, it is prevented from flowing further by the preset valve 68.
The annular duct 16 is supplied from the surface with compressed air at low pressure, for example at a pressure of 6 bars.
The drawings do not show the connections for the simultaneous supply of the hammer drill with compressed air and gas oil, and they also do not show the structure of the extension pipes for connection to the surface, because this is quite conventional equipment.
Reference will now be made to FIGS. 3 to 6, and also to FIG. 8, in order to explain the operation of the hammer drill supplied in this manner with compressed air and gas oil. In FIG. 3, as in FIG. 1 previously referred to, the percussion piston 38 is shown in the lower position, just after its impact on the shank of the drill bit. In this position, the compressed air coming from the duct 16 fills the chamber situated above the piston 25, and by way of the ducts 26 and the apertures 42 it reaches the grooves 41. By way of the apertures 43, the groove 39 and the apertures 45, the compressed air also fills the grooves 44, and thence by way of the apertures 46 reaches the bottom chamber 70 under the percussion piston 38. The pressure in the bottom chamber 70 causes the percussion piston 38 to rise, without any reaction other than its dead weight, because the upper chamber 71 is then in free communication with the exhaust leading outside the hammer drill by way of the apertures 51, the grooves 48 and the annular chamber 49.
When in its upward stroke the percussion piston reaches the position shown in FIG. 4, the supply of compressed air to the chamber 70 is interrupted by the closing of the apertures 45. The groove 39 has then, however, brought the apertures 43 and 55 into communication, so that compressed air arrives in the grooves 54. Air is then introduced through the apertures 57 into the chamber 71, whose exhaust 51 has already been closed. At the same time, the compressed air is introduced through the apertures 56 into the chamber 72 situated below the elastic diaphragm 36. Reference will now be made to FIG. 8, in which it will be seen in greater detail that the pressure thus produced in the chamber 72 deforms the elastic diaphragm 36 by a crushing action, and the central core 35 drives the piston 63 into the chamber 62. The higher pressure thus produced in the chamber 62 then exceeds the preset value of the valve 28 and gas oil flows from the chamber 62 to the atomizer 29 via the duct 67. A certain amount of gas oil is thus sprayed into the chamber 71.
Through the impetus previously acquired the percussion piston 38 continues its upward stroke, and when it reaches the position shown in FIG. 5, the closing of the apertures 43 stops the supply of compressed air both to the chamber 71 and to the chamber 72. In addition, the groove 39, which then brings the apertures 55 and 51 into communication, connects the chamber 72 to the exhaust. The fall in pressure in this chamber 72 returns the diaphragm 36 and the piston 63 to their positions of rest, thus bringing about the termination of the spraying of gas oil into the chamber 71.
The continuation of the upward movement of the piston 38 brings about heavy compression of the mixture of air and gas oil in the chamber 71, thus causing the spontaneous ignition of the mixture. The resulting explosion violently drives the percussion piston 38 towards the shank of the drill bit 3 (FIG. 6), without back pressure because the lower chamber 70 is then connected to the exhaust by the uncovered apertures 50.
In the course of its downward stroke the percussion piston 38 first closes the exhaust 50 of the chamber 70, and then establishes communication between the exhaust and the chamber 71, from which the burned gases are evacuated through the apertures 51; the compressed air is then again supplied to the chamber 70 when the groove 39 again brings into communication the apertures 43 and 45, and the cycle can start again.
It is thus seen that in each cycle, i.e., to for each forward and return movement of the percussion piston 38, the active phase of propulsion of the percussion piston towards the drill bit is the result of the explosion of a fuel mixture, i.e., of a pressure in the chamber 71 far higher than the pressure resulting in conventional equipment from the effect of compressed air, even at high pressure of the order of 20 to 25 bars, for example. The consumption of compressed air is practically limited to that required for the upward movement of the piston, and this phase can be carried out with low pressure air, because of the benefit of the rebound effect of the shock on the end of the shank of the drill bit. The additional amount of air used in the upper chamber 71 is relatively limited, because the final compression is effected by the piston itself, and it is for that reason that the supply apertures 57 are of small diameter.
The cooling of the internal combustion engine thus incorporated in the hammer drill, and more particularly of the zone of the combustion chamber 71, is effected simultaneously by three streams of gas. A first direct cooling is effected by a continuous circulation of fresh air in the grooves 58 supplied directly by the ducts 26 and 75 and the apertures 74; the section of the ducts 75 is determined in such a manner as to branch off only a part of the compressed air of the general supply to the hammer drill, and in such a manner as not to reduce substantially the pressure in the grooves 41, which in turn have to supply the grooves 44 and 54.
The chamber 71 is in addition cooled by the fresh air circulating in the grooves 44, which is renewed in each cycle, principally for supplying the bottom chamber 70.
Finally, the body 1 of the hammer drill also participates in the cooling of the chamber 71 through the direct contact of the outer wall of the liner 7 with the inner wall of the body 1 in all the zones separating the various longitudinal grooves; a contact zone of this kind is visible in FIG. 2. The body 1 itself is cooled externally by the exhaust air coming from the bottom ducts 60 and rising in the hole along the body.
Although the drilling power of a hammer drill of this kind is far greater than that of conventional equipment, the consumption of compressed air is very greatly reduced and makes it possible to use much smaller equipment which is less expensive to purchase and less expensive in consumption of energy. The supply of compressed air at low pressure of the order of 6 bars requires in fact only connection to a customary supply system or to a compressor unit which is inexpensive to purchase and in respect of consumption. It will be noted that both the low pressure air, after it has done its work in the lower chamber 70, and the exhaust gases after explosion in the chamber 71, are still mixed together in the chamber 49 and then at the outlet of the hammer drill in the ducts 60. The total volume of gases, particularly those coming from the combustion gases in the chamber 71, is considerable, thus facilitating the blowing away of the debris around the drill bit. | A "hole bottom" hammer drill comprising a tubular body (1) supplied with compressed air, a drill bit (3) and a percussion piston (38) caused to move in an inner cylinder (7) by a mechanism distributing compressed air alternately below and above the piston.
The hammer drill includes a device (29) for injecting gas oil into the chamber (71) above the piston (38) and a mechanism (34, 35) for triggering the injection during the upward stroke of the piston (38); the additional compression effects the combustion of the air-gas oil mixture, thus projecting the piston (38) towards the drill bit (3). | 4 |
[0001] This application is a continuation application of the U.S. patent application Ser. No. 10/597,910, filed Aug. 11, 2007, which claims priority to International Patent Application No. PCT/GB2005/000447, filed Feb. 9, 2005, which claims priority to United Kingdom Patent Application No. 0403109.2, filed Feb. 12, 2004. The entirety of all of the aforementioned applications is incorporated herein by reference.
FIELD
[0002] This invention relates to apparatus for the creation of outer surfaces having certain effects for structures. In particular, the invention relates to gabion facades and to gabion inserts.
BACKGROUND
[0003] In European Patent No. 0466726, there is set forth a cage structure useful in connection with the creation of building blocks, which can be used for sea defenses, shoring hillsides, and for providing military defense walls. These structures are made of open mesh panels, for example of welded mesh material, or twisted wire construction. The advantage of the structure set forth is that the panels are used to form the walls of the structure, with the panels being pivotally connected under factory conditions and the structure can be folded to a flat collapsed condition for transportation to site. On site, simply by manipulation, the structure is capable of being moved from the collapsed condition to an erected condition, in which the structure defines a row of open topped cavities which can be filled with soil, sand, rubble or the like to form a wall (or part thereof), shoring block or the like. The invention has been successful commercially on a worldwide basis.
[0004] The type of gabion described in EP-B-0466726 has applications in the military field, as well as in civil and environmental defense. Other types of gabion have applications in landscape design and in decorative or aesthetic connections, such as garden ornaments or window boxes. It may be desirable in some circumstances to provide such gabions with a surface effect which allows the gabion fill material to be obscured from view by a surface effect material in use of the gabion.
[0005] As well as aesthetic reasons for providing a surface effect, a problem which has been encountered with some gabions is that in certain climates, particularly hot climates, the material which is used to fill the cavities formed by the panels can be susceptible to changing conditions under temperature extremes. For example the material may be caused to contract in cold weather or expand in hot weather which can cause the structure to be less rigid or threaten to “burst” the joins between the panels.
[0006] A further problem is that in certain instances it can be desirable to provide a building structure with a particular surface effect, which it might not otherwise have from the material used to fill the cavities.
[0007] It should be clear that the invention can be applied to other building structures and situations. This should be borne in mind despite the fact that in the following a structure of the type described in the applicant's patent EP0466726 is given as a particular embodiment of the invention. Other types of gabion are particularly susceptible to improvement with this invention.
[0008] In a collapsible/erectable structure it is difficult to give the walls, or one wall a different surface effect than would be achieved as a result of the materials used for the structure and the filling material. It is disclosed in the said patent that when the structure is erected and filled, the walls can be given a different surface effect by the spraying of decorative synthetic resin onto the walls of the erected structure. However, it may be desirable that the walls were to have a different surface effect, say of aesthetically attractive materials such as pebbles, turf or of other vegetation effect, or a surface effect for protective purposes that could not be achieved with the structure specifically described in the said patent.
SUMMARY
[0009] The present invention provides an apparatus whereby an outer surface can be provided, which is other than the surface which would be achieved without the invention with the located surface effect being of advantage from an appearance effect and/or in controlling the condition of the building structure.
[0010] Accordingly, the present invention provides cage structure comprising opposed side walls connected by opposed end walls defining a cage cavity therebetween, the cage structure being provided on at least one side or end wall with a façade spaced from said side or end wall to an extent sufficient to accommodate a surface effect material between the at least one side or end wall and the façade.
[0011] Preferably the façade comprises a material which permits viewing of the surface effect material when thus accommodated.
[0012] Also provided is a cage structure comprising opposed side walls connected by opposed end walls defining a cage cavity therebetween, the cage structure being provided on at least one side or end wall with an insert spaced from said side or end wall to an extent sufficient to accommodate a surface effect material between the at least one side or end wall and the insert. Preferably the side or end wall on which the insert is provided comprises a material which permits viewing of the surface effect material when thus accommodated.
[0013] The façade or insert may comprise a secondary cage structure comprising opposed side walls connected by opposed end walls defining a cage cavity therebetween.
[0014] The cage structure may be in the form of a multi-compartmental gabion comprising pivotally connected side and end walls and at least one pivotally connected partition wall, the at least one partition wall separating individual compartments of the gabion. In this case the façade or insert may comprise a secondary cage structure in the form of a multi-compartmental gabion comprising pivotally connected side and end walls and at least one pivotally connected partition wall, the at least one partition wall separating individual compartments of the gabion.
[0015] The cage structure may be provided with a first fill material filled against the façade or against the side or end wall on which the insert is provided, and a second fill material filled behind the first fill material, the second fill material being a different material from the first fill material.
[0016] The present invention also provides a cage structure comprising opposed side walls connected by opposed end walls defining a cage cavity therebetween, the cage structure being provided on at least one side or end wall with a façade spaced from said side or end wall to an extent sufficient to accommodate a surface effect material between the at least one side or end wall and the façade, the façade comprising a material which permits viewing of the surface effect material when thus accommodated.
[0017] Also according to the present invention there is provided a cage structure comprising opposed side walls connected by opposed end walls defining a cage cavity therebetween, the cage structure being provided on at least one side or end wall with an insert spaced from said side or end wall to an extent sufficient to accommodate a surface effect material between the at least one side or end wall and the insert, the side or end wall on which the insert is provided comprising a material which permits viewing of the surface effect material when thus accommodated.
[0018] It will therefore be seen that the invention permits the adaptation of a gabion structure to provide a surface effect by blocking or partially blocking through at least one side or end wall of the gabion viewing of a gabion fill material located in the gabion by interposing between the viewer and the gabion fill material a surface effect material accommodated either on the outside of the said side or end wall (and retained in place by the façade) or on the inside of the said side or end wall (and retained in place by the insert).
[0019] The façade may for example comprise a mesh material which permits viewing of the accommodated surface effect material through the mesh holes. Alternatively, the façade may comprise a transparent material—such as glass, acrylic or Perspex™ for example.
[0020] In the case of an insert, the side or end wall on which the insert is provided preferably comprises a mesh material which permits viewing of the accommodated surface effect material through the mesh holes.
[0021] If the surface effect material has a technical function rather than an aesthetic function, it is not necessary for the surface effect material to be viewable from the outside. Thus, if the surface effect material has anti-corrosive properties, for example, the façade or the side or end wall on which the insert is provided may be opaque
[0022] The façade or insert is preferably connected to the side or end wall on which it is provided, or may be connected either side of said side or end wall to neighbouring pairs of side, end walls. In the case of a multi-compartmental gabion, an insert may alternatively (or also) be connected to one or more partition walls neighbouring the side wall on which the insert is provided (partition walls in this case being the walls dividing compartments of a multi-compartmental gabion)
[0023] Such connection is preferably achieved by suitable mechanical means, for example one or more connectors, clips, ties or fasteners.
[0024] The connection, particularly in the case of a façade, may be removable. That is to say, the connector(s), clip(s) tie(s) or fastener(s) may be releasable or removable to allow detachment, or partial detachment, of the façade or insert. Such connection may be pivotal (one edge of the façade or insert being pivotally connected to a corresponding edge of the side or end wall, for example), or the façade or insert may be completely removeable from the side or end wall.
[0025] In accordance with the invention there is provided an apparatus for creating an outer surface of a structure wherein at least one wall of the structure defines a support surface, the apparatus comprising means defining a covering surface which overlies the support surface but is movable therefrom, so that a quantity of material to create the outer surface can be positioned between the support surface and the covering surface, and wherein the covering surface is in the form of a panel. When the surface effect material has an aesthetic quality. typically the panel is a mesh panel or transparent panel through which the said surface effect material can be viewed.
[0026] In accordance with the invention there is provided an apparatus for creating an outer surface of a structure wherein at least one wall of the structure defines a support surface, the apparatus comprising means defining a covering surface which overlies the support surface but is movable therefrom, so that a quantity of material to create the outer surface can be positioned between the support surface and the covering surface, and wherein the covering surface is in the form of a panel. Typically the panel is a mesh panel or transparent panel through which the said surface affect material can be viewed.
[0027] Preferably, the support surface is defined by a mesh panel, and the edges of the cover panel are connected to the edges of the support mesh panel by means of suitable connectors. Suitable connectors may be in the form of elongated, coiled wire connectors threaded round the edges of the mesh panels at a pair of opposite edges of such panels, or threaded about intermediate spacing panels which serve to space the outer panels from the support of the structure.
[0028] Preferably, the structure is defined by a series of mesh panels, and the edges of the cover panel are connected to the edges of the support mesh panel by means of elongated, coiled wire connectors threaded round the edges of the mesh panels at a pair of opposite edges of such panels, or threaded about intermediate spacing panels which serve to space the outer panels from the support of the structure.
[0029] In one embodiment, the cover panels can be pivoted away from the support panel, or be removed therefrom to a sufficient extent to allow a cavity to be formed for the reception of the material to create the outer surface. The material can for example be a layer of turf or other horticultural vegetation, or decorative wood planks, board, or wooden fencing members (such as chestnut fencing poles), rocks, boulders, gravel to be placed on the support panel, or within the cavity. The cover panel can if required be positioned to retain the said material and again if required be connected, by re-threading the coiled wire connector through the edges of the cover and support panels, to trap the material in position between the panels.
[0030] The cover panel may be detached completely by removing both coiled wire connectors, or if the cover panel is mounted so as to lie spaced from the support panel to a sufficient extent, then the material may be positioned between the panels without removing the cover panel.
[0031] The support panel may be a wall panel of a collapsible structure as described above. Indeed, and as can be expected, all of the wall panels of one or both sides of such a structure may be provided with a surface effect as set for the above. The outer surfaces for the individual wall panels will usually be the same, but they could be different as desired. The invention also extends to a structure as described above, but wherein the various panels, or at least some of them are delivered to site, and the structure is erected on site by connecting the panels together, the outer surface being added after erection of the structure, or in an alternative arrangement, each support panel and its cover panel may be pre-connected and constructed to receive the material to form the outer surface therebetween.
[0032] Where the outer surface is created by growing material, this may eventually grow to such an extent as to conceal the cover panel mesh, and so using the collapsible structures mentioned above, could provide a quick means of erecting say a grassy bank, or a boundary hedge wall, which would have a natural look, without the need for any excavation. The invention therefore has considerable advantages. The invention may also have advantages in garden and landscape design, allowing the erection of structures having pleasing outer surface effects created with minimal use of an outer surface effect material.
[0033] A further advantage is that by selecting the appropriate material to form the outer surface, so heat insulation can be achieved by the said material thereby preventing adverse effects from the heat on the structure or the filling material or on other items adjacent the structure.
[0034] Typically, each or selected sides of the structure can be provided with the panels thereby allowing an outer surface to be created on all or selected sides of the structure. In addition, the material used to form the outer surface can also be positioned on the top of the structure to form an outer surface thereon.
[0035] In a further aspect of the invention there is provided a structure comprising a series of interconnected side panels forming a cavity for the reception of filling material therein to form a building structure having opposing side walls and end walls and wherein additional panels are provided along at least the side walls, externally thereof and joined to the same but spaced apart to form respective first and second cavities for the reception of material which differs to the filling material and form outer surfaces along at least the side walls.
[0036] In one embodiment the material used has better insulating characteristics than the filling material.
[0037] By way of explanation, an embodiment of the invention, with modifications, is illustrated in the accompanying diagrammatic drawings, and is explained in the description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] FIG. 1 shows in perspective view, a wall created by collapsible/erectable structures as described herein;
[0039] FIG. 2 is an exploded perspective view of the parts defining one cavity of one of the structures shown in FIG. 1 ;
[0040] FIG. 3 is an elevation view of one of the structures of FIG. 1 , to show how it can be folded to the collapsed position;
[0041] FIG. 4 is a perspective view of the wall of FIG. 1 , but showing the cover panels attached to form a structure according to the embodiment of the invention;
[0042] FIG. 5 is a view similar to FIG. 2 , but shows a modification;
[0043] FIG. 6 is a view similar to FIG. 4 , but showing the wall with the surface effect layers in position;
[0044] FIG. 7 is a view similar to FIG. 2 , but showing a further modification;
[0045] FIG. 8 is a cross sectional view taken on the line X-X in FIG. 6 , showing the support mesh, the cover mesh panel and the surface effect layer;
[0046] FIGS. 9 and 10 respectively are views to show two of the many different types of surface effect layer which can be used;
[0047] FIG. 11 is a plan view of a collapsible/erectable structure of a different type which can be used;
[0048] FIG. 12 is a plan of the structure shown in FIG. 11 , to illustrate how it can be folded to the collapsed condition;
[0049] FIG. 13A shows, in perspective view, a multi-compartmental cage structure with a façade; and
[0050] FIG. 13B shows, in perspective view, a multi-compartmental cage structure with an insert.
DETAILED DESCRIPTION
[0000] Method to Execute the Invention
[0051] In FIG. 1 , a wall 10 is made up of three conventional collapsible/erectable structures of the type described herein and superimposed one upon the other as shown. The structures are illustrated by the reference numerals 12 , 14 and 16 . In this example the structures are of trapezoidal cross-section so that the bottom one 12 is the broadest, whilst the top one 16 is the narrowest. The structures are made up of panels as described, and these panels are interconnected by means of coiled wire connectors 18 , in known manner.
[0052] The structures 12 , 14 and 16 have no top or bottom, so that each defines a row of cavities 20 , 22 , 24 and so on, and the structures can be of any appropriate length. Typically, the structure may be of 10 cavity lengths but this is not to be considered as limiting.
[0053] In a practical example, the inner surfaces of the panels of the structures 12 , 14 and 16 are lined with a retaining material such as a geo-textile material so that when the structure cavities 20 , 22 and 24 are filled with appropriate filling material such as soil, sand, rocks or other ballast, that material will not pass through the meshes of the panels, it being remembered that the panels making up the structure will normally be of welded mesh construction.
[0054] These structures and the features described are of course already known.
[0055] FIG. 2 shows typically how the panels are used in each structure to form one cavity of the structure. In FIG. 2 the panels shown form the cavity 20 of the top structure 16 , and the panels comprise two similar mesh side panels 26 and 28 , and two end panels 30 and 32 , which comprise trapezoidal rod boundaries and intermediate parallel connecting rods, although this is still considered to be a mesh structure. Although shown in a trapezoidal form it should be appreciated that the structures can be cube or cuboid in shape, or any other suitable shape. The panels 26 to 32 are connected by means of the coiled wire connectors 18 , one of which is shown in greater detail in FIG. 2 , but each of the axes 18 A represents the position of one of these connectors. To connect the panels shown in FIG. 2 , they are brought into the trapezoidal configuration shown in FIG. 1 , and then the connectors 18 are spirally wound about the adjacent end bars of the panels so that each connector 18 embraces two bars of the respective adjacent panel edges. By this means, the panels are all pivotally connected together, and having regard to the diameter of the connector 18 , so there is a relatively free pivotal movement and there is a certain amount of clearance so that the panel edges are free to move within the connectors.
[0056] Of the panels 30 and 32 , if the panel 30 is at the end of a structure, it will be an end panel, but panel 32 will be common to the next cavity, and it is commonly known as a partition panel. The spiral connectors which connect panels 26 and 28 to panel 32 therefore also simultaneously embrace the next adjacent side panels of the next cavity, and so on.
[0057] It will be understood that the structures depicted in FIG. 1 is therefore foldable by relative pivoting between the various panels, and FIG. 3 is included to show how the structures can be folded. FIG. 3 shows the top structure 16 , and the additional panels making up cavity 22 are indicated by reference numerals 26 A, 28 A and 32 A. To collapse the structure the alternate partition panels 30 and 32 A are moved in opposite directions as indicated by the arrows 34 and 36 and so the whole structure can fold up zigzag or concertina fashion. Although the partition panels 32 and the end panels 30 are of trapezoidal form, there is sufficient clearance within the coil connectors 18 to allow complete folding to take place. Each of the structures 12 , 14 and 16 is collapsible in the same way, and therefore can be folded up for transportation purposes.
[0058] The structures 12 , 14 and 16 need not be of trapezoidal form, but this form is of particular advantage in relation to the utilisation of the present invention.
[0059] In the present invention, the outer surfaces of the panels of the structures shown in FIG. 1 are provided to receive material to form an outer surface to give the overall wall the appearance of having a surface of a material which is different from that which is typically placed in the cavity 20 , 22 , 24 . Referring to FIG. 4 , one embodiment is shown and in this embodiment, additional cover panels 40 to 50 are connected to the side panels of the structures as shown. These panels 40 to 50 are connected to the panels using the same connector coils 18 or in a modification, separate connector coils, and the coils connect so that the panels 40 to 50 are pivotable by virtue of being connected to these coils.
[0060] In order to provide the material to form the outer surface of the structure the panels 40 to 50 are pivoted clear of the side panels of the structures 12 , 14 and 16 , which side panels form support panels and the material can either be applied over the support panels as shown or placed into cavities defined between the support panels and cover panels. When the material is applied, the cover panels 40 to 50 are pivoted back onto the material, and are connected to each other by means of a coiled wire connector such as 18 at the free edges which are shown in FIG. 4 and which meet when the cover panels are placed into position. The coiled wire connectors which connect panels 40 and 46 , 42 and 48 , and 44 and 50 , may be coupled to the existing coiled wire connectors connecting the structure side panels by the insertion of a connecting rod through the two coiled connectors which are moved sufficiently close so that the coils overlap, thereby trapping the surface effect material which is viewable through the panels 40 to 50 as these panels also are of mesh construction. The effect is in fact shown in FIG. 6 , where the dashed line areas are intended to represent material which in this embodiment is turf, so that the wall eventually will have a turf surface appearance. This is applied over the whole of the wall surface.
[0061] Instead of placing turf between the support and cover mesh panels, other suitable horticultural material can be used such as the material known as “seedam” which is a material which is supplied as a thin layer and in rolls, and is simply unrolled and placed on the ground. The layer comprises soil bound by means of a woven fabric, and the soil contains a seed material from which green vegetation grows.
[0062] FIG. 8 is included to show a section of this material, and in this figure the growing material is indicated at 52 as it grows through the cover panel 44 , and the support panel 26 is also illustrated. Between the support panel and the cover panel is the fabric 54 which forms the binding for the material, and also illustrated is the soil layer 56 . The Seedam material has roots which grow rearwards, and these are shown at 58 where they pass through the geo-textile material 60 on the inner side of support panel 26 .
[0063] The Seedam material is so constructed that the soil and binding fabric will retain moisture enabling the vegetation 52 to grow efficiently, but the addition of the geo-textile material 60 provides a further means for the retention of moisture, and the invention therefore is of particular relevance to the effective growing of the Seedam material. The Seedam material provides an excellent green covering and growth is limited as compared for example to grass so that cutting of the Seedam material is not necessary and therefore it is particularly suitable for this application.
[0064] Instead of the panels 40 to 50 being pivotally mounted as shown in FIG. 4 , they can be detachably mounted and the material for the outer surface can be mounted on the panels 40 to 50 and then the panels and the material applied as appropriate.
[0065] If reference is made to FIG. 5 , modifications are shown therein to the end panel 30 . At one side end panel is shown as having an extension wing 62 which forms a connecting bar for the coiled connectors. If the bar 62 is used for example for mounting the cover panels 40 to 50 , then these panels 40 to 50 will be spaced slightly further from the support panels of the structures so that thicker surface effect layers can be positioned between the panels. In this case the structure panel would be connected to rod portion 64 , and the cover panel would be connected to rod portion 62 .
[0066] Another modification shown in FIG. 5 is indicated that the opposite side of panel 30 and comprises an extension ladder 66 . One rail 68 of that ladder would be coupled to the end panel rod portion 70 by a coiled connector, whilst the other rail 72 serves for the mounting of the cover panel. If either of these modifications is adopted, it would be adopted on each of the end and partition panels of the foldable structure.
[0067] Another modification of this character is shown in FIG. 7 where the side panels 26 and 28 are replaced by a frame 74 , which serves to receive a mesh tray 76 . The tray 76 has a mesh base and rod extension sides 78 and 80 and a base extension 82 of the form shown. The structure is built using the side panels 74 , and when it is erected into a wall, the tray 76 is fitted for the receipt of the surface effect material which can be quite thick having regard to the height of the extensions 78 and 82 . After the tray is fitted, and the surface effect material is inserted, a cover panel such as 40 to 50 is applied over the tray to retain the surface effect material. All or one or more of the side panels of the structures 12 to 16 may be constructed in this way.
[0068] FIGS. 9 and 10 show how solid material may be used to form the outer surface and these are preferably used where the spacing between the support and cover panels is sufficient and these panels are held in spaced relationship.
[0069] In FIG. 9 it is shown that wooden planks 84 may be dropped in behind the cover panels or may be placed in the tray 76 of FIG. 7 , whilst FIG. 10 shows that chestnut-fencing posts 86 may be used for creating the surface effect. In another arrangement, the surface effect is created by one or more metal plates.
[0070] FIGS. 11 and 12 are included to show that collapsible/erectable structures in accordance with the invention may be of a different configuration from that shown in FIGS. 4 to 10 . In the arrangement of FIG. 11 , additional pivot connections are provided at 90 in each side of the structure. These pivot connections are parallel to the other pivot connections on that side of the structure and again is created by a coiled wire connector. Each side of each cavity therefore is split into two equal sections which can pivot relative to one another during the collapsing and erecting operations of the structure.
[0071] FIG. 12 shows how the structure can be collapsed by pivoting the side sections outwardly so that the partition panels 30 , 32 , 32 A and so on move together in the direction of the arrows 92 as shown in FIG. 12 . In this arrangement material can be placed into the cavities 93 when the structure is in the erected condition shown in FIG. 11 , with the material placed therein forming the outer surface of the structure on both elongate side walls of the structure. For example, if it is desired that the outer surface which is formed has insulating properties, then material with such properties which are better than the material used to fill the main cavities 22 , 24 and so on can be used to fill the cavities 93 and hence provide the insulating outer surface. Such material could be rocks or the like and which therefore serve to insulate the structure as a whole. Furthermore, if required, the material used to form the outer surface of the elongate side walls can also be used to form the outer surfaces of the end walls of the structure in cavities formed therein, in the same manner by the addition of the panels and/or the top of the structure by placing and, if necessary, securing the insulating material in position, and even the base of the structure by placing said material onto the surface prior to placing the structure thereon and then filling the same.
[0072] Another modification shown in FIG. 13A provides a multi-compartmental cage structure 100 comprising opposed side walls 110 and 120 connected by opposed end walls 130 and 140 and at least one pivotally connected partition wall 150 . The at least one partition wall 150 separating individual compartments 160 of the cage 100 . The cage structure 100 further comprises a façade 200 in the form a secondary cage structure comprising opposed side walls 210 and 220 connected by opposed end walls 230 and 240 and at least one pivotally connected partition wall 250 . The façade 200 can accommodate a surface effect material 270 and comprises a material which permits viewing of the surface effect material when thus accommodated. Preferably, the end wall 230 of the façade 200 may define a cover panel that comprises a material which permits viewing of the surface effect material 270 .
[0073] In another modification shown in FIG. 13B , the cage structure 100 further comprises an insert 300 in the form a secondary cage structure comprising opposed side walls 310 and 320 connected by opposed end walls 330 and 340 and at least one pivotally connected partition wall 350 . The insert 300 can accommodate a surface effect material 370 and comprises a material which permits viewing of the surface effect material when thus accommodated. Preferably, the end wall 130 of the cage structure 100 and the end wall 330 of the insert 300 comprise a material which permits viewing of the surface effect material 370 .
[0074] A further possible embodiment of the invention may be contemplated in which the panels are provided with integrally formed limbs. Each limb may have a return that can engage a part of the gabion. In use, a layer of decorative material such as turf is interposed between the gabion and the panel. The panel is pressed against the gabion causing the decorative layer to compress. The limb bends to pass a wire of the gabion. Releasing the panel allows the decorative layer to expand back to its original dimension thereby causing the return of the limb to engage a wire of the gabion. Limbs can be provided instead of the aforementioned hinge-engaging fasteners or supplementary thereto. Additionally or alternatively, one or more limbs may be disposed towards the centre of each panel to inhibit bowing-out of the panel in use, which adverse effect may occur over time, e.g., as grass/vegetation root systems establish.
METHOD OF INDUSTRIAL APPLICATION OF THE INVENTION
[0075] In this invention it is not necessary that the structures are erected in the factory. They could be erected on site, where some or all of the pivot connections are made, and the surface effect material could be inserted in the erected structure on site or it could be supplied between the support and cover panels and supplied as panel units.
[0076] The invention provides a means of adding to the functionality and/or the aesthetic appeal of a gabion structure. Thus, if it is desired to provide a gabion structure with an exterior surface effect for aesthetic reasons, this can be achieved by using a surface effect material with aesthetic properties. Alternatively, if it is desired to provide a gabion structure with an improved functionality (e.g., resistance to weathering, corrosion, heat expansion, water penetration and the like) then a suitable functional material can be selected as the surface effect material.
[0077] The invention provides that an outer surface on the side walls of the structure can be created by using a covering mesh panel, where such effects either visual and/or protective would not normally exist. The invention has particular application to the collapsible type structures discussed herein, and can be used to maintain the characteristics of the same in extreme environmental conditions by preventing expansion or contraction and hence improving the safety of the structures as required. | The present invention provides an apparatus for creating an outer surface effect of a structure wherein at least one wall of the structure defines a support surface, the apparatus comprising means defining a covering surface which overlies the support surface but is movable therefrom, so that a quantity of material to create the outer surface effect can be positioned between the support surface and the covering surface, and wherein the covering surface is in the form of a panel. | 4 |
BACKGROUND
1. Field of the Invention
The invention relates to a drive train of a solely electrically drivable motor vehicle, having an axle which has a differential, and two electric machines, wherein the axle is drivable by means of the electric machines via at least one gearing.
2. Description of the Related Art
Such a drive train, which is used for an electrically drivable earth-moving vehicle or for an agricultural vehicle with four-wheel drive, is known from DE 600 13 340 T2. Said drive train has two electric machines which are arranged above the rear axle of the motor vehicle in the direction of travel and interact with a spur gearing which is arranged in front of the rear axle. The gearing is connected via one shaft or two shafts to the differentials which are assigned to the two axles, therefore to the rear axle and to the front axle of the motor vehicle.
It is the object of the present invention to provide a drive train in a motor vehicle to be operated solely electrically, which drive train makes it possible to drive in different driving situations with particularly good efficiency.
SUMMARY OF THE INVENTION
The drive train of the solely electrically drivable motor vehicle therefore has two electric machines. One of the two electric machines, referred to below as the first electric machine, interacts with a first gearing, and the other of the two electric machines, referred to below as the second electric machine, interacts with a second gearing. The first gearing is connectable via a first switchable clutch to an input gear of the differential, for driving two axle sections of the axle, which axle sections are connected to different outputs of the differential. The first gearing is connectable via a second clutch to a first axle section of the axle when the first clutch is open, and the second gearing is connectable via a third clutch to a second axle section of the axle when the first clutch is open.
This configuration of the drive train with the two electric machines, the two gearings assigned to the latter and the three clutches makes it possible either to drive the two axle sections of the axle by driving only the first electric machine via the first gearing assigned thereto and the differential assigned to said gearing, or else not to introduce the driving force into the differential and, instead, to drive each axle section directly by means of the electric machine assigned thereto. This independent drive of the respective axle section of the axle permits an individual wheel drive of the motor vehicle wheel assigned to the respective axle section and of the running wheel of the motor vehicle. As a result, a torque vectoring of the axle sections of the axle or of the wheels of the axle is possible. Said torque vectoring does not cause any loss due to a braking engagement on the axle section of the one or other wheel.
In the driving mode, in which force is transmitted via the differential, only the one electric machine—the first electric machine—is operated, when the first clutch is closed, while the two other clutches—the second and third clutches—are open. By contrast, in individual wheel drive, the first clutch is open and the second and third clutches are closed.
The driving of the motor vehicle only by the one electric machine—the first electric machine—is advantageous if driving situations depending on low energy consumption are to prevail. In particular whenever critical driving situations in terms of driving dynamics are to prevail, the switch is made to the individual wheel drive. Said critical driving situations in terms of driving dynamics are, in particular, those which are critical under safety aspects and a stabilizing intervention on the vehicle is required.
The two electric machines and the three clutches preferably have control means, by means of which, when the first electric machine is in operation, the first clutch is closed and the second and third clutches are open, or, when the electric machines are in operation, the first clutch is open and the second and third clutches are closed.
The gearings are preferably designed as spur gearings. They can be accommodated in the relatively small construction space. In particular, the gearings have identical transmission ratios.
The electric machines are arranged in particular transversely with respect to the direction of travel of the motor vehicle.
The drive train is preferably used in a motor vehicle which is in the form of a passenger vehicle. Said passenger vehicle is in particular a sports car. Said motor vehicle, in particular the passenger vehicle or the sports car, is preferably in the form of a rear drive. The two electric machines are therefore arranged in the rear region of the motor vehicle or of the drive train. It is considered to be particularly advantageous if the two electric machines are arranged behind the rear axle.
In principle, however, the motor vehicle can be in the form of a front drive.
The wheels assigned to the drive train are suspended in particular individually via propeller shafts. The drive train therefore does not have a rigid axle.
Further features of the invention emerge from the dependent claims, the attached drawing and the description of the preferred exemplary embodiment, which is reproduced in the drawing, without being limited thereto.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a schematic diagram of a preferred embodiment of the drive train according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The exemplary embodiment according to FIG. 1 illustrates a drive train for a solely electrically drivable motor vehicle, which is in particular a passenger vehicle, specifically a sports car. The rear axle of the drive train assigned to the motor vehicle and, furthermore, a non-driven front axle of the motor vehicle is shown.
The drive train 1 with individual wheel suspension has the first, rear axle 2 . With respect to the forward direction of travel 3 of the motor vehicle, referred to below as direction of travel, the rear axle 2 has a left axle section 4 and a right axle section 5 . The left and the right wheel of the rear axle 2 are denoted by the reference number 6 , and bearings for the axle sections 4 and 5 of the rear axle 2 are denoted by the reference number 7 . The axle sections 4 and 5 of the rear axle 2 have propeller shafts.
The motor vehicle furthermore has a second, front axle 8 which is not driven. This axle 8 also has individual wheel suspension. The front axle 8 has a left axle section 9 and a right axle section 10 . The left and right wheel of the front axle 8 are denoted by the reference number 11 , and the bearings for the axle sections 9 and 10 of the front axle 8 are denoted by the reference number 12 . The axle sections 9 and 10 of the front axle 8 likewise have propeller shafts.
The rear axle 2 is drivable by means of two electric machines 13 and 14 . In this case, the electric machine 13 interacts with a gearing 15 and the electric machine 14 interacts with a gearing 16 . The gearings 15 and 16 are arranged substantially behind the rear axle 2 , and the two electric machines 13 and 14 are each arranged transversely with respect to the direction of travel 3 . The axis of rotation of the respective electric machine 13 or 14 , illustrated by the driven shaft 17 thereof, is therefore arranged in the direction of travel 3 .
The stator of the respective electric machine 13 or 14 is denoted by the reference number 18 , and the rotor of the respective electric machine 13 or 14 , to which rotor the driven shaft 17 is connected, is denoted by the reference number 19 . The respective driven shaft 17 is mounted in bearings 20 .
The driven shafts 17 of the two electric machines 13 , 14 are arranged on the same geometrical axis, and therefore the axis of rotation of the stators 18 of the electric machines 13 and 14 corresponds to said geometrical axis.
Apart from the minor difference still to be described below, the two gearings 15 , 16 are arranged mirror-symmetrically with respect to the longitudinal axis of the vehicle and are of identical design. They therefore have identical transmission ratios. The gearings are designed as spur gearings.
The respective gearing 15 or 16 has a pinion 21 which is connected to the driven shaft 17 for rotation therewith and is designed as a spur gear. Said pinion 21 meshes with a spur gear 22 of the respective gearing 15 or 16 , which spur gear is connected to a shaft 23 for rotation therewith. Said shaft is mounted on the end sides in bearings 24 . A pinion 25 is arranged next to the spur gear 22 and is connected to the shaft 23 for rotation therewith. The pinion 25 of the gearing 16 meshes with a spur gear 26 which is mounted in a freely rotatable manner in the right axle section 5 of the axle 2 . The spur gear 26 is connected to a clutch part 27 for rotation therewith, which clutch part can be brought into an operative position with a clutch part 28 which is connected to the right axle section 5 for rotation therewith.
A spur gear 29 which is modified in relation to the spur gear 26 interacts with the pinion 25 of the other gearing 15 . In the same manner as the spur gear 26 , said spur gear 29 is mounted in a freely rotatable manner in the axle section of the axle 2 , in the present case the left axle section 4 , and is connected to a clutch part 30 , which is designed in a manner corresponding to the clutch part 27 , for rotation therewith. Said clutch part 30 can be brought into an operative position with a clutch part 31 which is connected to the left axle section 4 for rotation therewith and in this respect corresponds to the clutch part 28 with regard to construction and arrangement.
The spur gear 29 which is assigned to the left axle section 4 basically differs from the spur gear 26 which is assigned to the right axle section 5 in that the spur gear 29 non-rotatably receives a clutch part 32 . The latter can be brought into operative connection with a clutch part 33 , which is switchable and with the aid of which a non-rotatable connection can be produced between the spur gear 29 and an input gear 34 of a differential 35 . The two axle sections 4 and 5 are connected to two outputs of the differential 35 for rotation therewith.
Accordingly, the clutch parts 32 and 33 form a first switchable clutch 36 , the clutch parts 30 and 31 form a second switchable clutch 37 , and the clutch parts 27 and 28 form a third switchable clutch 38 . In a first driving situation, in which it suffices to drive the vehicle by means of one of the two electric machines, specifically the electric machine 13 , and in which an energy-saving driving manner occurs, the first clutch 36 is closed and the second and third clutches 37 , 38 are open. The electric machine 14 is switched off. Accordingly, only the electric machine 13 transmits the torque via the gearing 15 , and accordingly, the spur gear 29 and the clutch 36 to the differential 35 and from there via the two axle sections 4 and 5 to the wheels 6 .
If, by contrast, a critical situation in terms of driving dynamics prevails, the wheels 6 of the rear axle 2 can be driven individually. The first clutch 36 is open and the second and third clutches 37 , 38 are closed. In this case, force is not transmitted via the differential 35 to the axle sections 4 and 5 of the rear axle 2 , but rather the transmission takes place in a first torque train from the electric machine 13 via the gearing 15 assigned thereto to the clutch 37 and from there to the left axle section 4 with the wheel 6 assigned thereto. The electric machine 14 is connected by a second torque path via the gearing 16 to the closed clutch 38 , and therefore the right axle section 5 and the wheel 6 assigned thereto are driven via said clutch. Different torques of the electric machines 13 , 14 make is possible for different torques to be introduced into the two axle sections 4 and 5 , thus enabling torque vectoring of the rear axle 2 by means of individual wheel drive.
The two electric machines 13 and 14 and the three clutches 36 , 37 , 38 have control means, by means of which, when the first electric machine 13 is in operation, the first clutch 36 is closed and the second and third clutches 37 , 38 are open, or, when the two electric machines 13 , 14 are in operation, the first clutch 36 is open and the second and third clutches 37 , 38 are closed. | A drive train ( 1 ) of a solely electrically driven motor has an axle ( 2 ) with first and second axle sections ( 4, 5 ) connected to different outputs of a differential ( 35 ). The drive train also has a first and second electric motors ( 13, 14 ) that co-operate with first and second transmissions ( 15 ) respectively to drive the axle ( 2 ). A first clutch can connect the first transmission ( 15 ) to an entry wheel ( 34 ) of the differential ( 35 ) for driving the two axle sections ( 4, 5 ) of the axle ( 2 ). A second clutch ( 37 ) can connect the first transmission ( 15 ) to the first axle section ( 4 ) while the first clutch ( 36 ) is open and a third clutch ( 38 ) can connect the second transmission ( 16 ) to a second axle section ( 5 ) while the first clutch ( 36 ) is open. | 8 |
RELATED APPLICATIONS
This application claims priority to other applications as set forth in the Application Data Sheet filed in this application. Each of the patents and/or applications listed on the ADS is hereby incorporated by reference.
BACKGROUND
1. Field of the Invention
This invention relates to managing groups of computers and more particularly relates to managing policies for configuring hardware or software settings on groups of computers with a plurality of operating systems.
2. Description of the Related Art
A major concern of information technology management in corporations and other organizations has been balancing the complexity associated with managing large numbers of computers with the needs of individual users as they try to accomplish their tasks. A heterogeneous set of computer hardware, operating systems, and application software creates complexity and increased costs, but various combinations of hardware, operating systems, and software provide technical advantages when used as user workstations, departmental servers, corporate infrastructure equipment, and the like. User workstations are particularly difficult to manage when various needs and preferences of individual users are accommodated. For example, an engineer may require the use of a CAD system that runs only on the UNIX operating system, where other corporate users may be standardized on the MICROSOFT WINDOWS operating system and associated applications. Many similar compatibility issues exist among current computer systems.
One factor that adds to the complexity of managing various operating systems is that different operating systems employ different techniques for setting configuration information. For example, MICROSOFT WINDOWS and applications that run on Windows typically use a database, called the registry, to store configuration information. Computers running the UNIX operating system or derivatives thereof such as LINUX typically store configuration information in plain text files in particular locations in the file system directory. Information technology managers within an organization that uses heterogeneous operating systems typically institute separate sets of management procedures and standards for each operating system used in the organization.
One component of prior art solutions to the problem of managing large numbers of computers and users is the use of policies. Policies are used to set configurable options associated with an operating system or application program for a group of computer users. For example, a word processing program may have an option to select an American English dictionary or a British English dictionary. By creating one policy for its users in the United States and another policy for its users in England, an organization can set the appropriate option for all users without configuring each user's computer individually.
Another component of prior art solutions to the problem of managing groups of computers and users is the use of network directory services. Directory services provide an infrastructure to store and access information about network-based entities, such as applications, files, printers, and people. Directory services provide a consistent way to name, describe, locate access, manage, and secure information about these resources. The directories associated with directory services are typically hierarchical structures such as a tree with each node in the hierarchy capable of storing information in a unit often referred to as a container. Enterprises may use directory servers and directory services to centrally manage data that is accessed from geographically dispersed locations.
For example, corporations typically create network directory trees that mirror their corporate organizations. Information about individual employees, such as their employee number, telephone number, and hire date may be stored in a user object corresponding to each user in the directory tree. An organizational unit container representing each department may contain the user objects associated with each employee in the department. Organizational unit objects associated with each corporate division may contain the department organizational unit objects associated with each department in the division. Finally, an organization container representing the corporation as a whole may contain the company's division organizational unit objects.
Combining the use of policies and directory services facilitates management of groups of computers and users. Policies may be associated with the various containers in the directory services tree to store associated configuration information at the organization, division, or departmental level. For example, a policy may be associated with the Accounts Receivable container in a corporate organization to set options for the accounting program used in that department. Exceptions to the policy can be managed on an individual level, or by creating a group object and associating a policy with the group. Suppose, for example, that all employees in an organization use a software application with a particular set of configuration options, but department managers require a different set of options. A policy could be created with the basic set of options and associated with the organization container. A separate policy with the configuration options for managers could be created and assigned to a Managers user group object.
Using policies and directory services in combination has proven efficient in homogeneous operating system environments. Prior art computer management systems use policies targeted toward a specific operating system, referred to as the native operating system. From the point of view of prior art policy and policy management systems, other operating systems are considered to be foreign operating systems. However, the operating requirements of many organizations require information technology managers to manage multiple operating systems. The efficiencies associated with policies and directory services have not been realized in heterogeneous operating system environments. Since different operating systems use different approaches to setting configuration information, a policy associated with a directory services container may be applied to users of a native operating system that provided the policies, but there may not be a method for applying the policy for users of a foreign operating system.
From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method that extend the use of policies to manage configuration information on computers having operating systems that are foreign to the policy creation and management environment. Beneficially, such an apparatus, system, and method would control cost and complexity associated with management of computers with heterogeneous operating systems within an organization. The benefits are multiplied when network directory services are used in conjunction with policies.
SUMMARY
The present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available policy management systems. Accordingly, the present invention provides an apparatus, system, and method for managing policies on a computer having a foreign operating system that overcome many or all of the above-discussed shortcomings in the art.
In one aspect of the present invention, a method for managing policies on a computer having a foreign operating system includes providing a policy on a first computer with a native operating system, receiving the policy on a second computer with a foreign operating system, and translating the policy to configuration information usable on the second computer. In one embodiment, the method includes receiving the policy on the second computer at workstation start-up. The method also may include updating the policy at user login. These embodiments facilitate obtaining the current policy at the time they are typically needed by operating systems.
In further embodiments, the method includes polling the first computer at periodic intervals for changes to the policy. In these embodiments, configuration information usable on the second computer is updated to reflect changes in policy on the first computer, to keep the configuration information and policy closely synchronized. The method may also con include applying configuration information associated with directory services containers and objects. For example, a policy associated with a directory services organization container may be translated to configuration information that may then be applied to all users in the organization container.
In another aspect of the present invention, an apparatus to manage policies on a computer having a foreign operating system includes a policy on a first computer having a native operating system, a policy translator that translates the policy to configuration information usable on a second computer having foreign operating system, and a translator manager that manages the association between the policy on the first computer and the translator on the second computer. The apparatus, in one embodiment, is configured to manage configuration information usable on a second computer having a foreign operating system by means of policies on a first computer having a native operating system. A translator manager manages the association between the policy on the first computer, and a policy translator on the second computer.
The apparatus is further configured, in one embodiment, to include policies associated with network directory services containers and objects. Policies may be associated, for example, with organization containers, organizational unit containers, and user objects, facilitating the configuration of hardware or software information for groups of computer users at a corporate, department, or individual level.
Various elements of the present invention may be combined into a system arranged to carry out the functions or steps presented above. In one embodiment, the system includes two computers, the first having a native operating system and the second having a foreign operating system. In particular, the system, in one embodiment, includes a directory services server and database, a communications network, a policy, a policy editor, a policy template, a translator manager, and a policy translator.
Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment.
Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention.
These features and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:
FIG. 1 is a schematic block diagram depicting one embodiment of a typical prior art networking environment wherein the present invention may be deployed;
FIG. 2 is a schematic block diagram illustrating one embodiment of a prior art policy management apparatus;
FIG. 3 is a schematic block diagram illustrating one embodiment of a policy management system in accordance with the present invention;
FIG. 4 is a schematic block diagram illustrating another embodiment of a policy management system in accordance with the present invention;
FIG. 5 is a schematic flow chart diagram illustrating one embodiment of a provide translator method in accordance with the present invention;
FIG. 6 is a schematic flow chart diagram illustrating one embodiment of a policy translation method in accordance with the present invention; and
FIG. 7 is a text diagram illustrating one embodiment of policy translation example data in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Many of the functional units described in this specification have been labeled as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.
Modules may also be implemented in software for execution by various types of processors. An identified module of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module.
Indeed, a module of executable code could be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network.
Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
FIG. 1 depicts one embodiment of a typical prior art networking environment 100 that demonstrates the issues regarding managing currently deployed enterprises. As depicted, the networking environment 100 includes one or more servers 110 , a network 120 , and one or more networked computers 130 . The components of the networking environment 100 may reside at a single site or may be dispersed over multiple sites.
Some of the servers 110 may be directory servers or domain servers which can function as a registry for resources and users of the networking environment 100 . The network 120 may include routers, bridges, hubs, gateways, or the like which facilitate communications among the components of the networking environment 100 . Some of the networked computers 130 may execute legacy applications and operating systems that are unable to integrate with the servers 110 that are directory servers.
Some of the networked computers 130 may be used to run utility applications to manage the servers 110 that are directory servers and features of the directory service that runs on the servers 110 . These networked computers 130 that manage the directory service typically do not include functionality to manage foreign operating systems that may run on other networked computers 130 .
FIG. 2 is a schematic block diagram illustrating one embodiment of a prior art policy management apparatus 200 . The prior art policy management apparatus 200 includes a policy template 210 , a policy editor 220 , a first computer 260 having a native operating system, and a second computer 270 having the same native operating system. The first computer 260 includes a policy manager 230 a , a policy-related file 240 , and a configuration information database 250 a . The second computer 270 includes a policy manager 230 b , and a configuration information database 250 b . This apparatus is configured to efficiently manage a group of computers having like operating systems.
An administrative user may use a policy template 210 and a policy editor 220 to control the operation of the policy manager 230 a . The policy template 210 and the policy editor 220 may be located on the first computer 260 or may be on another computer. The policy manager 230 a may use a policy-related file 240 and settings (i.e. information) in a configuration information database 250 a to record the policy settings created by the administrative user.
As a means for efficiently managing a group of computers with like operating systems, a policy manager 230 b in a second computer 270 may be configured to obtain policy settings by reading from the policy-related file 240 or the configuration information con database 250 a on the first computer 260 , as represented by the dashed lines 233 and 236 in FIG. 2 . The policy manager 230 b may then make settings to the configuration information database 250 b on the second computer 270 .
The policy may include configuration information that applies specifically to the second computer 270 , or to a specific user or any of a group of users of the second computer 270 . Configuration information may be associated with network directory services containers and objects. For example, by associating configuration information with an organizational unit container, the behavior of an application can be controlled for all users in a company department. Configuration information maybe assigned to containers and objects at various levels in a directory services hierarchy, facilitating management of hardware and software configuration information at various organizational, geographical, or individual levels. For example, application configuration information may be associated with an organization container, organizational unit container, and user object in a network directory services hierarchy, resulting in application configuration options being assigned at corporate, departmental, and individual levels in an organization.
FIG. 3 is a schematic block diagram illustrating one embodiment of a policy management system 300 in accordance with the present invention. The depicted policy management system 300 includes a network 310 , a first computer 320 , and a second computer 340 . The first computer 320 includes a policy template 322 , a policy editor 324 , a policy manager 230 , a policy-related file 326 , and a configuration information database 250 . The depicted second computer 340 includes a translator manager 342 , a translator 344 , and a policy-related file 346 . The policy management system 300 facilitates management of a group of computers with multiple operating systems by using the first computer 320 as a reference computer from which configuration information are replicated to other computers in a workgroup, or the like. The policy management system 300 depicted in FIG. 3 represents a peer-oriented embodiment of the present invention, where the first computer 320 and the second computer 340 are workstations, and no server is required.
An administrative user may use a policy template 322 and policy editor 324 to control the operation of the policy manager 230 . The policy manager 230 may use a policy-related file 326 and settings or information in a configuration information database 250 to record the policy settings created by the administrative user. The translation manager 342 in the second computer 340 may be configured to obtain policy settings by reading from the policy-related file 326 and the configuration information database 250 on the first computer 320 , as represented by the dashed lines 333 and 336 in FIG. 3 . The translation manager 342 then passes the policy settings obtained from the first computer 320 to the translator 344 to translate to configuration information that may be stored in a policy-related file 346 on the second computer 340 . In some embodiments, the translator 344 modifies configuration information stored in a plurality of files. The policy-related file 346 may not be exclusively dedicated to storing policy information. For example, the policy-related file 346 may contain non-policy data or code. In some embodiments, the operating system on the first computer 320 may provide an event notification system that notifies the translation manager 342 that changes have been made to the policy-related file 326 or the configuration information database 250 .
FIG. 4 is schematic block diagram illustrating another embodiment of a policy management system 400 in accordance with the present invention. The policy management system 400 includes a server 410 , network 310 , a first computer 320 , and a second computer 340 . The server 410 includes a policy-related file 413 , and a configuration information database 416 . The first computer 320 includes a policy template 322 , a policy editor 324 , and a policy manager 230 . The second computer 340 includes a translation manager 342 , a translator 344 , and a policy-related file 346 . The policy management system 400 facilitates management of a group of computers having multiple operating systems by replicating configuration information from a server 410 , such as a directory server. The policy management system 400 depicted in FIG. 4 represents a client-server-oriented embodiment of the present invention, where configuration information are stored on a server 410 and replicated to client workstations represented by the second computer 340 .
As with the embodiment depicted in FIG. 3 , an administrative user may use a policy template 322 and policy editor 324 to control the operation of the policy manager 230 . In this embodiment, however, the policy manager 230 may use a policy-related file 413 and settings in a configuration information database 416 to record the policy settings created by the administrative user on a server 410 . The translation manager 342 in the second computer 340 may be configured to obtain policy settings by reading from the policy-related file 413 and the configuration information database 416 on the server 410 , as represented by the dashed lines 433 and 436 in FIG. 4 . The translation manager 342 then passes the policy settings obtained from the first computer 320 to the translator 344 to translate to configuration information that may be stored in a policy-related file 346 on the second computer 340 .
The following schematic flow chart diagrams that follow are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. Other steps, methods, and orderings may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method.
FIG. 5 is a schematic flow chart diagram illustrating one embodiment of a provide translator method 500 in accordance with the present invention. The provide translator method 500 includes a provide policy template step 520 , and a provide policy translator step 530 . The provide translator method 500 provides modules that facilitate translation of policy settings from a native operating system to a foreign operating system.
The provide policy template step 520 provides a policy template such as the policy template 322 to be used in conjunction with the policy editor 324 , or the like. As detailed in FIG. 3 and elsewhere, the policy template 322 constrains policy editing, such that policies created by the policy editor 324 conform to requirements of the first computer 320 . For example, the policy template 322 may ensure that configuration information car delivered to the policy manager 230 conform to a required syntax, or that numerical values fall within a meaningful range. The provide policy template step 520 may provide a plug-in module to an operating system utility program. In some embodiments, the provide policy template step 520 provides a wizard program module that guides a user through the process of creating a policy.
The provide policy translator step 530 provides a translator 344 that translates configuration information from the first computer 320 having a native operating system to the second computer 340 having a foreign operating system. The provide policy translator step 530 may place the translator 344 in a file system directory known to the translator manager 342 . In some embodiments, the provide policy translator step 530 may register the file system location of the translator 344 with the translator manager 342 . Upon completion of the provide policy translator step 530 , the provide translator method 500 ends 540 .
FIG. 6 is a schematic flow chart diagram illustrating one embodiment of a policy translation method 600 in accordance with the present invention. The policy translation method 600 includes a provide policy step 620 , a receive policy step 630 , a translate policy step 640 , an update configuration step 650 , an update on start-up test 655 , a wait for start-up step 660 , an update on login test 665 , a wait for login step 670 , a refresh time test 675 , and a terminate test 685 . The policy translation method 600 translates policies on a first computer 320 having a native operating system to policies for a second computer 340 having a foreign operating system.
The provide policy step 620 provides a policy on the first computer 320 having a native operating system. The provide policy step 620 may be performed by an administrative user using a policy template 322 , policy editor 324 , and/or policy manager 230 . The policy may be contained in a policy-related file 326 and a configuration information database 250 on the first computer 320 . In some embodiments, the policy may be contained in a policy-related file 413 and a configuration information database 416 on a server 410 , such as a directory server.
The receive policy step 630 receives the policy on the second computer 340 having a foreign operating system. The receive policy step 630 may be performed by a translator manager 342 on the second computer 340 . The translator manager 342 may copy the policy from a policy-related file 326 and a configuration information database 250 on the first computer 320 . In other embodiments, the translator manager 342 may copy the policy from a policy-related file 413 and a configuration information database 416 on a server 410 , such as a directory server. The translator manager 342 transmits the policy to a translator 344 .
The translate policy step 640 translates configuration information from the first computer 320 having a native operating system to the second computer 340 having a foreign operating system. The translate policy step 740 may be performed by a translator 344 on the second computer 340 . The translator 344 receives the policy from the translator manager 342 and translates the policy to foreign operating system configuration information used by the second computer 340 .
The update configuration step 650 applies the configuration information translated by the translator 344 . The update configuration step 650 may be performed by a translator 344 on the second computer 340 having a foreign operating system. After translating the policy to foreign operating system configuration information, the translator 344 applies the policy by saving the configuration information in a policy-related file 346 . In some embodiments, configuration information may be saved in a plurality of policy-related files 346 .
The update on start-up test 655 determines whether the policy is to be applied at workstation start-up. A policy may contain configuration information for all users of the second computer 340 . Many operating systems apply configuration information at workstation start-up. Updating configuration information on the second computer 340 during workstation start-up makes the updated settings available for application during the workstation start-up process. If the policy is to be updated at workstation start-up, the policy translation method 600 continues with the wait for start-up step 660 , otherwise the policy translation method 600 continues with the update on login test 665 .
The wait for start-up step 660 waits for the second computer 340 to reach a point in the workstation start-up process where computer resources are available for the second computer 340 to receive the policy from the first computer 320 . The wait for start-up step 660 includes setting a configuration setting that causes the policy translation method 600 to continue with the receive policy step 630 at workstation start-up. The wait for start-up step 660 facilitates receiving the current version of the policy so that configuration information may be applied to the second computer 340 at workstation start-up, when many operating systems typically read configuration information. Updating a policy at workstation start-up is particularly advantageous to workstation-specific configuration information.
The update on login test 665 determines whether the policy is to be applied at user login. A policy may contain configuration information that applies to a specific user or any of a group of users of the second computer 340 . In some embodiments, configuration information may be associated with network directory services containers and objects. For example, by associating configuration information with an organizational unit container, the behavior of an application can be controlled for all users in a company department. Updating configuration information on the second computer 340 makes the current version of the settings available for application for the user logging in. If the policy is to be updated at user login, the policy translation method 600 continues with the wait for login method 670 , otherwise the policy translation method 600 continues with the refresh time test 675 .
The wait for login step 670 waits for a user to log in to the second computer 340 to receive the policy from the first computer 320 . The wait for login step 670 includes setting a configuration setting that causes the policy translation method 700 to continue with the receive policy step 630 at user login. The wait for login step 670 facilitates receiving the current version of the policy so that configuration information may be applied to the second computer 340 at user login, when many operating systems typically read configuration information. Updating a policy at user login is particularly advantageous to user-specific configuration information.
The refresh time test 675 determines whether it is time to check for updates to the policy on the first computer 320 . In some embodiments, the refresh time test 675 polls the first computer 320 at periodic intervals for changes to the policy. The polling interval may be configurable by the user or may itself be a setting configurable by a policy. In some embodiments, the refresh time test 675 may include a means for the first computer 320 to notify the second computer 340 that a change has been made to the policy, and that the policy should be refreshed on the second computer 340 . If the refresh time has arrived, the policy translation method 600 continues with the receive policy step 630 , otherwise it continues with the terminate test 685 .
The terminate test 685 determines whether the refresh time test 675 should be repeated, or if the policy translation method 600 should terminate. In some embodiments, the policy translation method 600 may be terminated to facilitate deallocation of memory or other computer resources when the second computer 340 is shut down, or to allow for system maintenance. If the policy translation method is not to be terminated, it continues with the refresh time test 675 , other wise it ends 690 .
FIG. 7 is a text diagram illustrating one embodiment of policy translation example data in accordance with the present invention. The policy translation example data 700 includes policy template data 710 , policy manager input data 720 , native policy-related file data 730 , and translated policy-related file data 740 . The policy translation example data may be generated in accordance with the policy translation method 600 and the policy management system 300 .
The policy template data 710 is one example of the policy template 322 . The policy template 322 may reside on the first computer 320 having a native operating system or on a third computer, such as an administrative workstation. The policy template data 710 may comprise plain ASCII text used to constrain data input accepted by the policy editor 324 by identifying names of data objects that the policy editor 324 will allow the user to edit. Policy template data 710 may also contain the text of prompts or other fields that control the user interface presented by the policy editor 324 . Using the policy template 322 , the policy editor 324 may accept input from an administrative user and generate input data for the policy manager 230 .
Policy manager input data 720 illustrates the format of data that may be generated by the policy editor 324 . In various embodiments, in accordance with the provide policy step 620 , the policy manager 230 may accept the policy manager input data 720 from a file created by the policy editor 324 , from a file created by an administrative user, or communicated directly from the policy editor 324 to the policy manager 230 via interprocess communication. The policy manager 230 may alter the format or contents of the policy manager input data 720 . In some embodiments, the policy manager creates a policy-related file 326 and enters the location of the policy-related file 326 in the configuration settings database 250 .
The native policy-related file data 730 is a textual representation of binary data in one embodiment of the policy-related file 326 . The native policy-related file data 730 is generated by the policy manager 230 , and in preparation for the receive policy step 630 , is stored in a format and location typically used with the native operating system in use on the first computer 320 . In the depicted embodiment, the native policy-related file data 730 comprises mixed binary and UNICODE text delimited by square brackets.
The translated policy-related file data 740 is one example of the policy-related file 346 . In accordance with the translate policy step 640 , the translator 344 translates the policy data received from the translator manager 342 to data usable by the foreign operating system used by the second computer 340 . The depicted translated policy-related file data 740 is one example of a configuration file that a translator 344 has converted from mixed binary and UNICODE format to plain ASCII text format, and filtered to include only data usable by the foreign operating system in use on the second computer 340 . In the depicted example, the translated policy-related file data 740 comprises a list of user names that will be allowed to log in to the second computer 340 .
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | An apparatus, system, and method are disclosed for managing policies on a computer having a foreign operating system. Policies may specify hardware or software configuration information. Policies on a first computer with a native operating system are translated into configuration information usable on a second computer having a foreign operating system. In an embodiment, a translator manager manages the association between the policy on the first computer and the translator on the second computer. Computer management complexity and information technology management costs are reduced by centralizing computer management on the native operating system. Further reductions in management complexity are realized when the present invention is used in conjunction with network directory services. | 6 |
Reference to related application, assigned to the assignee of the present application, the disclosure of which is hereby incorporated by reference: U.S. application Ser. No. 692,381, filed Jan. 17, 1985, Heinz Bohmler et al, now U.S. Pat. No. 4,677,558, granted June 30, 1987, "Method and System for Controlling Operation of an Apparatus or Engine, Particularly Internal Combustion Engine".
Reference to related patents: U.S. Pat. No. 4,084,240; U.S. Pat. No. 4,255,789, Hartford, the disclosures of which are hereby incorporated by reference.
Reference to related publications: "Elektronik", No. 22, 1982, p. 143 et seq.
The present invention relates to a control system utilizing a computer and more specifically a microprocessor to control operations within an automotive vehicle, and more specifically to control the engine of the automotive vehicle. The invention is specifically directed to the interaction between the microprocessor or computer and a programmable read-only memory, which can be programmed to match specific required operating data of the automotive engine and/or vehicle.
BACKGROUND OF THE INVENTION
Microprocessors are increasingly used to control operation of the engine of an automotive vehicle or of other automotive vehicle components, such as, for example, braking, and/or clutching systems used therein. Microcomputers which are used in such vehicles work together with memories, usually programmable memories. Different vehicles which may require similar programming steps, for example to control the ignition instant of an automotive engine, may operate, however, based on different characteristic data. The characteristics of engine operation, for example relating ignition instant or ignition timing to engine temperature, loading and the like, vary with different engines, although the computation steps to compute the proper ignition instant based on the various characteristics are identical. Thus, it is possible to use a single microprocessor, programmed to carry out programming sequences with various types of engines or vehicles, provided the data on which the processor carries out its programs are matched to the respective engine or vehicle.
The referenced publication "Elektronik", No. 22, 1982, p. 143 et seq., describes an apparatus in which a microprocessor is connected to a serially operating interface which, in turn, is connected to a programmable memory. Data can be transmitted between the microcomputer and the memory via the serial interface. Data transmitted, for example, from the memory to the microprocessor are then processed in the microprocessor in accordance with its program. Flexibility of the system is ensured by using a memory in which the data, for example, can be changed.
U.S. Pat. No. 4,255,789, Hartford, describes a control system for a motor vehicle in which a microprocessor works together with a programmable memory. The memory is programmed, or has data entered thereinto before assembly with the operating control system. Change in a program is possible only, after incorporating the memory in the system, by replacing an integrated circuit element of the memory. Such change of the program is, however, desirable even after installation in the system, for example to compensate for effects of aging. In practical application, problems arise when utilizing a microprocessor with a preprogrammed memory. If the overall system is located within a sealed housing, change in the memory content can only be obtained by exchanging a memory integrated circuit (IC), or a group of memory ICs. This requires opening the housing, or other interference with its integrity, which may permit contamination of the contents of the computerized control system by dirt and/or dampness or humidity. Locating the memory IC on a plug-in base interferes with the integrity and operating reliability of the overall system since, in the environment of an automotive vehicle, plug-in connections of ICs are difficult to maintain in perfect contact due to the subjection to shock, vibration, changes in temperature, and the like, conditions endemic in operation of an automotive vehicle, although not necessarily encountered in office computer applications.
It has been proposed to provide programmable memories for use in combination with vehicular-type microprocessors, in which the programming or memory content to be stored in the memories can be carried out by external programming units, so that the read-only capability to be utilized by the microprocessor can be based on data specific to a particular type of engine, vehicle, or a specific use thereof. It is then possible to program the data within the memory, for example, to be particularly applicable to a specific engine, and/or customer requirements. For example, the data which can be stored in the memory may be idle speed, fuel/air mixture for use under idling, and the like. Programming for such conditions is best carried out during production of the vehicle, and/or at an installation stage when the vehicle is associated with a specific control unit, that is, during a mass-production run. Such programming during mass-production permits matching not only the data to be stored to a specific engine, but, additionally, for example to environmental conditions such as quality of fuel to be expected with which the vehicle is to be used, composition of fuel--for example whether containing alcohol or only hydrocarbons--use under tropical conditions and the like; changes due to production variations, for example within a production series, are likewise possible without exchange of the entire control unit. It is also not necessary to merely exchange a pre-programmed memory for another one, so that plug-in connectors for the memory units can be eliminated, thus substantially increasing the operating reliability of the overall control system.
SUMMARY OF THE INVENTION
It is an object to improve the control system of the type referred to which further increases the operating reliability by preventing interference with a program content or memory content in a programmable memory associated with a microprocessor, to prevent external, unauthorized or undesired interference with the memory content and further to safeguard the memory content upon improper operation or improper conditions, for example collapse of battery voltage, removal of operating power, and/or resumption of operating power at a voltage level different from previous voltage levels, for example upon exchange of a battery, or the like.
Briefly, an interface is provided for connecting data between a programming unit and a programmable memory, which includes a release-and-enable bus, coupled to the memory and being connected through the interface.
In accordance with a feature of the invention, data are entered into the programmable memory from a programming unit, the memory being capable of being addressed by the computer to retrieve data from the memory for carrying out computation operations by the computer. The computer itself receives vehicle operating data from the vehicle and computes control data for use by the computer, for example data from a receiving unit, and retransmitted to the transmitting unit, for example the programming unit, and checked to match the transmitted data. If so, the data transmission is continued. If, however, the data should be incorrect, an error subroutine can be entered into.
The system, thus, operates based on what is sometimes termed a "handshake" operation, that is, mutual acknowledgement of correctness of transmitted information, or entry into an error subroutine, if errors in transmission should be detected. Passing the release-and-enable bus through the interface and utilizing the signals on this bus in connection with the transmission routine ensures that unauthorized retrieval or alteration of data will not be possible since the back-and-forth flow of data over the various buses is based on the specific characteristics of the data themselves.
The control system and method has the advantage that the memory of the control unit itself can be programmed externally without requiring exchange of the physical memory IC itself, thus permitting entry of data specific to a particular engine and/or vehicle upon production thereof. This permits ready change-over of the particular memory data, within a general program, to conditions specific to a vehicle, such as, for example, expected fuel quality, use under specific climatic conditions, such as tropics, arctic, or the like; and, further, ready change of the stored data to adapt the data to a particular engine or engine series upon a change of characteristics in the engine, without, however, requiring general exchange of the entire control unit.
The release-and-enable line between the programming unit and the memory--or between the programming unit and the computer which, in turn, connects to the memory--provides for hardware lock-out of the memory which, without receiving a specific signal on the release-and-enable line, will not change its memory content, so that the data which the microprocessor will receive from the memory content will retain their initial program identity, regardless of attempts to change the data, either intentionally or unintentionally, or other environmental effects, such as stray voltages due to, resumption of different operating voltages, and the like.
In accordance with a desirable feature of the invention, the interface operates serially, and includes a separable plug-connection, so that the programming unit can be plugged-in to the interface element, and thus connected to the microcomputer and/or the memory unit; after programming, the plug connection is broken which then also will break the release-and-enable line. By use of the serial interface, data are transmitted serially, which require few physical connecting lines and thus permit sturdy and reliable plug connectors to be used. The interface can then be hard-wired and directly connected to the memory. It is thus possible to directly program the memory without requiring any specific memory programming program within the computer itself.
In accordance with a preferred feature of the invention, two bus lines connect the programming unit through the interface to the memory and/or the computer, one line transmitting data from the programming unit to the control unit, and the other line transmitting data in reverse direction. It is also possible, however, to use a single bidirectional control line and a second one which provides data indicating the direction of transmission, that is, providing an active, or passive signal. Such an arrangement permits connection of a number of units to a single serial bus which may have different baud rates. The parity of the data to be transmitted can be used to differentiate information from apparatus addresses, and from data to be used for programming.
The data can thus be inserted and entered into the control unit after it has been hard-wired. This, then, permits analog matching of data specific to a vehicle or apparatus by software, without having to open the control unit, or interfere with its structural or sealed integrity. It is thus possible to make a single control unit with a single programming memory for a large number of types of vehicles or engines, for example, in which the data specific to the types of engines and their uses are entered only later, thus permitting substantial economies due to mass-production while still providing for precise matching of data to a vehicle or engine.
The operation of electronic control units, particularly when using microcomputers, is increasingly determined by software. As the operating power of microcomputers increases and becomes more complex, hardware can be standardized, so that eventually, electronic control units for control of operating functions, for example in vehicles and engines, will differ only by the software within the computer and primarily within the memories, typically programmable read-only memories (PROMs), and especially electronically programmable ROMs (EEPROMs). Various types of ignition circuits having electronic ignition timing control use systems, the hardware of which is very similar, and in which the matching of engines, engine types and engine series to the ignition system can be determined entirely by software. Thus, it is possible to achieve economies in manufacture, testing, and eventual stocking of parts and components, since the physical control systems are identical, differing only in the software. Separate stocking of different control systems for different engines or types thus can be eliminated. The invention, thus, offers substantial simplification in manufacture and subsequent maintenance of vehicles and their engines.
Serial interfaces for programming of microprocessors are known. A serial interface alone, however, even when coupled to a control unit, cannot achieve the objects of the invention since programs or data which are transmitted to a microprocessor become lost upon loss of supply power. The integration into each control unit of a programming unit for an EEPROM, that is, a non-volatile memory, is not possible since the cost of such programming units for individual vehicles, for example, would be excessive, even if space therefor were available within the limited and environmentally undesirable engine compartment of the vehicle. In accordance with a feature of the invention, the microcomputer which is usually used to control the operation of the engine and/or the vehicle is controlled via an interface, preferably a serial interface, to program the non-volatile ROM and, if the ROM is released to receive data--and provide data to the programming unit, the programming unit can then proceed to directly program or, in other words, to directly enter data into the ROM which are specific to a particular engine and/or vehicle, as desired. This arrangement, thus, by use of the "handshake" system, ensures integrity of data in the ROM, or, typically, the EEPROM, while being responsive to changes of the particular programming unit only.
BRIEF DESCRIPTION OF THE DRAWING
The single figure illustrates, symbolically, a control unit for an automotive vehicle, to which a programming unit is connected to enter data specific to the vehicle, and as shown to the engine of the vehicle, in the memory of the control system.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A programming unit 1 is connected to a first bus 11, which may be termed a transmit bus, and a second bus 12, which may be termed a reply bus. The buses 11, 12 are connected to a control unit 2. The control unit 2 is part of a control structure or assembly for use in an automotive vehicle shown only schematically by a block 5. The control unit 2 provides for control of various functions, such as ignition timing, dwell angle, control of injection period in fuel injection systems and the like, all associated with an internal combustion engine (ICE) for the vehicle. Additionally, the control unit 2 may carry out various monitoring and supervisory functions within the automotive vehicle 5. The diagram is highly simplified and shows only those features necessary for an understanding of the invention. As shown, the control unit 2 receives operating data over a bus 26 from the engine 4, based on various sensors within or associated with the engine of the vehicle, and generates control data on a bus 27 for various operating or positioning elements within the vehicle or the engine, based on computations within the control unit 2. Typical data derived on bus 26 would be, for example, feedback data relating to ignition timing, dwell angle and the like; or operating data such as loading on the engine, engine temperature, environmental temperature, ambient air pressure or manually enterable data, such as data relating to seasonable operation of the vehicle, for example whether winter or summer, usually used fuel quality and the like. The output signals on line 27 control, then, such parameters as position of a throttle, fuel injection instant and time duration, current flow through an ignition coil at instant of interruption, determining, respectively, dwell angle and ignition timing, restriction of operating air during warm-up, exhaust gas recirculation (EGR) and the like. Control units to carry out commands on various operating lines of a command bus 27 are well known.
A plug-in interface 3 is provided in the buses 11, 12, which is part of the vehicle, securely connected thereto and hard-wired to the control unit 2. The plug-interface 3 may be physically connected to the control unit 2, for example forming part of the housing thereof, so that all components within the control unit 2 can be included within a sealed chamber, which cannot be readily opened, and where unauthorized access can be detected. The unit 2, thus, can be manufactured together with the plug-interface 3, and connected to the interface 3 as shown in the figure. The buses 26,27 may be conducted through the interface 3, if desired.
The control unit 2 has at least one internal interface 21, forming a serial interface which may be a standard chip of the Universal Asynchronous Receiver-Transmitter Type (UART). Both the buses 11,12 pass through the interface 3 to the UART 21. The control unit 2 further includes a microprocessor or computer 23, and a memory 25. The transmit bus 11 connects from the programming unit 1 through the plug-interface 3, the UART interface 21; the acknowledge line 12 connects from the UART interface 21 through the plug-interface 3 to the programming unit 1. An interface bus 22 connects between the UART interface 21 and the microprocessor 23; a memory bus 24 is connected between the microcomputer 23 and the memory 25.
In accordance with a feature of the invention, a release-enable bus 13 to permit programming signals or programming voltages to be transmitted from the programming unit 1 to the control unit 2 is likewise connected through the interface 3. The release-enable bus is connected directly between the memory 25 and the programming unit 1.
In ordinary operation of the vehicle, the microprocessor 23 receives data relating to the instantaneous operation of the vehicle from bus 26, for temporary storage within the microcomputer 23 and processing of the data. General programs or general data which are suitable for use with any type of vehicle are stored in a suitable operating memory within the microcomputer 23. Programs or data which are specific to an individual vehicle, or an individual engine, or to a specific series of engines or vehicles, are stored in the memory 25. The memory 25 is an EEPROM or a NVRAM, acronyms for Electrically Erasable Programmable Read-Only Memory or Non-Volatile Random Access Memory, respectively.
The programming unit 1 contains all data specific to a particular vehicle or engine, which are to be stored in the memory 25, that is, for example, data relating to fuel composition and characteristics of a specific country to which the vehicle is to be exported, data relating to particular types of engines or vehicles within a specific series, changes in specifications within a production series, and the like. The programming unit P may be placed in the installation of the vehicle manufacturer, or may be placed at the plant of the manufacturer of the control unit 2.
For programming of the control unit 2, the programming unit 1 is connected by a plug connection to the plug-interface 3, by providing connections to the bus 11, the bus 12, as well as the release enable bus 13. The programming unit 1 also includes a UART chip as receiver for serial data from the acknowledgement line 12.
Programming the Memory 25 and Operation of Control System:
The control unit is programmed by the programming unit P, 1, by first generating an addressing signal in the programming unit 1. The addressing signal is transmitted, for example over bus 11, three times, and has a specific characteristic, in the example selected, odd parity. When this control unit 2 receives at least three times a word of odd parity, it provides a "acknowledge" signal over line 12, for example, to the programming unit 1. The programming unit 1 thus will know that:
(1) the control unit 2 is ready to receive, and
(2) the control unit 2 is ready to be programmed.
The dialogue between the programming unit 1 and the control unit 2 is carried out over the two buses 11,12. Equivalent thereto and equally possible, is to carry out the dialogue over a bidirectional bus 11, and utilizing the bus 12 as an indication in which way the direction of transmission is intended.
In a typical example, the following convention or conditions are suitable and form the basis for the dialogue between the programming unit P and the control unit 2:
(a) control commands have odd parity
(b) data/addresses have even parity.
The data format includes a parity bit to ensure that the conditions are observed and can be properly decoded.
Continuing now the method of programming; after the programming unit 1 has addressed the control unit 2 by sending at least three times a word of odd parity, the control unit 2 provides the acknowledgement signal to the programming unit 1, likewise with odd parity. This is an indication to the programming unit 1 that the control unit 2 is ready to receive programming data.
The next signal provided from the programming unit 1 is a command which announces programming of the memory 25. Under the ASCII code, the command "L" for "load" is given. Thereafter, the data or addresses, respectively, follow:
start address high
start address low
number of data bytes
data bit 1, data bit 2
etc.
After each address or after each datum, respectively, the control unit 2 provides an acknowledgement signal. After the indicated number of data have been transmitted, the control unit 2 provides a "end" signal (ASCII command; "E"). At that point, the programming unit 1 provides a programming voltage to the release-enable bus 13.
If, for example, during the data transmission an error such as a bit error occurred, the control unit 2 will recognize the error due to the odd parity of the data. In such a case, the programming unit 2 will provide a "repeat" command to the programming unit 1, which, then, will repeat the last data transmitted. If, after several attempts, the data still have not been transmitted correctly, the programming unit 1 will terminate the transmission, release the programming voltage on the release-and-enable bus 13 and will provide an output indication to the operator of "malfunction", for example by lighting a "malfunction" indicator MI. The programming unit 1 can be so constructed that an error output listing can be printed out, so that the data which are to be transmitted from the programming unit and stored in the memory 25 can be analyzed for errors, so that specific error criteria can be targeted and then corrected.
The programming steps described are one of many possible steps. They will depend, specifically, on the structure of data and, respectively, on the way the "handshake" between the programming unit 1 and the control unit 2 is carried out. This will depend on the particular product specifications to be handled.
It is also possible to carry out synchronous serial data transmission over the lines 11,12 by transmitting on the line which is not used for data, a clock pulse controlling synchronization of the transmission.
If the transmission is correct, that is, when the programming unit 1 receives a "E" command from the control unit 2, the programming unit 1 sends a verification command (ASCII: "V"). The control unit 2 will then transmit the data which are stored in the memory 25 from the start address to the end address, back to the programming unit 1. The arrangement and method steps are the same as those used in the transmission from the programming unit 1 to the control unit 2. The transmitted and stored data are then compared in the programming unit 1 with the data which were originally transmitted by the control unit 1. If the transmission was correct, that is, upon congruence of data, the programming is terminated.
Upon incorrect transmission, the entire programming method or steps are repeated a second time. If, after a second programming, again, an error is detected, the programming unit 1 terminates programming and provides an output indication, for example on the malfunction indicator MI, or on an equivalent printout, to the operator.
The control unit 2, and preferably the microprocessor 23 thereof, includes analog/digital (AD) converters, which sense operating data communicated on bus 26 and provided in analog form, such as temperature of induction air, pressure in the intake manifold or induction type, battery voltage, and the like. The programming unit 1 then can control the microprocessor 23 to properly weigh the respective sensed quantities, for example by adding a predetermined constant, for example to compensate for an offset or the like, and/or to multiply by a predetermined factor, for example to compensate for amplification. The compensation may be required to compensate for manufacturing tolerances of components and sensors or elements, temperature drifting, aging or the like; such compensation may be required from time to time, and/or initially, and can be carried out electronically. The respective constants or factors can then be stored in the EEPROM memory 25.
The constant or the factor, respectively, can be determined by comparison with a reference value. For example: let it be assumed that battery voltage requires compensation. A battery voltage sensor of any suitable construction, for example a volt meter providing an analog output signal is connected to a reference voltage. The A/D converter within the control unit 2, and preferably within the microprocessor 23 then will provide a corresponding digital value. This value is transmitted from the command unit 2, for example via bus 12 to the programming unit 1. Programming unit 1 retains in its programming memory a command value which corresponds to the digital value of voltage represented by the reference voltage source. If there is a deviation of the value transmitted from the microprocessor 23 to the programming unit 1, a factor is derived representative of the difference, and transmitted, for example over bus 11, to the control unit 2 for storage in the EEPROM 25.
If more than one reference value is needed, for example two or more, a table, or characteristic curve can be linearly weighted, by providing a constant and a multiplication factor. Multi-dimensional characteristic curves, or characteristic curves and tables relating operating parameters to desired outputs likewise can be weighted, or calibrated with respect to standard values stored within the programming unit 1. A plurality of values are compared with respective reference values. For example, a parameter which depends on temperature can be checked in a temperature tunnel, by determining the actual output of the temperature sensor at the given temperature, for comparison with stored command values within the programming unit 1. The respective correction constants or correction multiplication factors are then readily determinable and stored in the EEPROM memory 25. During operation of the vehicle, for example under different temperature conditions, the microcomputer 23 then can recall the correction values and, for specific temperature values, interpolation of correction values will then readily determine the desired quantity or datum. Programs for interpolation of values between tabular, or graphically stored values are well known and can be provided in accordance with any desired subroutine.
Change of the data in the memory 25 other than by the programming unit 1, however, is not possible once the plug-in interface 3 has been severed from the programming unit P, 1 since, then, the release-enable bus 13 likewise is severed and the interplay of data transmission between the programming unit 1 and the control unit 2 likewise is interrupted, so that the required "handshake" operation relying on the respective parity of the data will not obtain. Only when the command ASCII "E" is provided, the programming unit 1 will provide the programming voltage on the release-enable bus 13. The correctness of the data transmission, of course, had previously been checked by the control unit given errors, recognized by the wrong parity, the data are repeated or retransmitted from the programming control unit for the predetermined period of time. If no correct transmission can be effected, the release-enable bus 13 is disabled, and the operator notified by the malfunction indicator MI. | To prevent change of data in a non-volatile programmable, ready-only memory (25) forming, together with a microprocessor (23) a control unit, for example for an automotive vehicle, while permitting programming of the memory from an external programming unit (P, 1), an interface (3, 11, 12) is provided through which a release-enable bus (13) also passes, data being transmitted in accordance with a predetermined characteristic--even or odd parity--, the parity correctness being checked. If the parity is correct, an "enter" signal is provided on the release-enable bus for storing the data; if not, retransmission is attempted for a predetermined number of time, and if it cannot be correctly effected, a malfunction indication output signal is generated. | 5 |
This is a Divisional application which claims priority of U.S. patent application Ser. No. 10/354,406, filed Jan. 30, 2003.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to database management in computer networks in general and, in particular, to managing said database in a manner that simplifies or condenses its size.
2. Prior Art
Broadly, a computer network may be viewed as a plurality of nodes interconnected by communications subsystems. The communications subsystems may include transmission link (such as a T1 line), local area network (LAN), wide area network (WAN), internet, etc. The nodes may include one or more devices such as switches, routers, bridges, network interface card (NIC), etc. Usually, NICs are components that are mounted in higher level devices such as a server, etc. As used in this document a node is deemed to be synonymous to one of these devices.
A switch is a network node that directs datagrams on the basis of Medium Access Control (MAC) addresses, that is, Layer 2 in the Open Systems Interconnection Basic Reference Model (OSI model) well known to those skilled in the art [see “The Basics Book of OSI and Network Management” by Motorola Codex from Addison-Wesley Publishing Company, Inc., 1993]. A switch can also be thought of as a multiport bridge, a bridge being a device that connects two LAN segments together and forwards packets of the basis of Layer 2 data. A router is a network node that directs datagrams on the basis of finding the longest prefix in a routing table of prefixes that matches the Internet Protocol (IP) destination addresses of a datagram, all within Layer 3 in the OSI model. A Network Interface Card (NIC) is a device that interfaces a network such as the Internet with an edge resource such as a server, cluster of servers, or server farm. A NIC might classify traffic in both directions for the purpose of fulfilling Service Level Agreements (SLAs) regarding Quality of Service (QoS). A NIC may also switch or route traffic in response to classification results and current congestion conditions. The present invention applies to a network node that can be a switch, a router, NIC, or, more generally, a machine capable of classifying packets and taking an action or actions (such as discarding the packet) based upon classification results.
A necessary component of the node is the database which is generated by a network administrator. The database may be used for a variety of purposes including filtering or network processing.
Network processing in general entails examining packets relative to the database and deciding what to do with them. Usually the action to be taken is part of or is recorded in the database. This examination can be costly in terms of processing cycles, and traffic can arrive irregularly over time. Consequently, to avoid backlogs, queuing latency and the danger of buffer overflow, network nodes in general must attempt to enforce security policies or other policies based upon classification as efficiently as possible.
The database is usually arranged as a matrix including a plurality of rows and a plurality of columns. Each row represents a rule in the database. The characters in the database matrix can be 0, 1 and * (Don't care or wildcard). Because the database is made out of only three character types it is often referred to as Ternary data structure. When the Ternary data structure is loaded in a Contents Address Memory (CAM) the combination (i.e. CAM and database is referred to as a Ternary Contents Address Memory (TCAM).
Information such as in a computer network packet can be given a key. Typically a key is a fixed binary expression that is the concatenation of bits from the standard header fields of the packet. A Ternary Content Addressable Memory (TCAM) includes rows that represent classifications or rules. The rows appear in an array (a matrix, in the present invention). Each row of the array includes logical tests matching bits in a key with 0, 1, and * (don't care or wildcard) entries For example, the key 0110 would fit the rule 01** since bits in the key match bits in the rule; of course, typical keys and rules would have many more than four bit positions. That is, the length of the row is the total number of entries and is constant (typically about 100 bit positions) for all rows. It is the number of columns in the array seen as a matrix. Each row points to an action (or possible a combination of actions) and a priority (to be used if one key can match multiple rows). An input key for a packet is derived from (perhaps equal to) a packet header field or the concatenation of packet header fields with the same length as the TCAM row length. The key represents the packet and is fed to the TCAM. A key is tested simultaneously for match with the corresponding 0, 1, and * entries in the row. If no rows fit, then a default action is taken (or an all * row is included with lowest priority). Else, of all the rows that do fit, the one with highest priority is selected and its action is enforced.
A 0, 1, * (Ternary) array logically identical to that searched by a TCAM can also be searched by numerous tree search methods. In tree search technology, a few bit positions are tested and, depending upon the location and relative frequency of 0, 1 entries versus * entries, the bit tests can eliminate from consideration all but one or a few rules or rows from consideration. That is, the bit tests can be used to show that the majority of rules cannot possibly fit a certain key, leaving a relatively simple test of the fall key by one remaining rule or a few remaining rules. U.S. Pat. No. 6,298,340 “System and method and computer program for filtering using tree structure” describes one such approach. An alternate approach, called the Balanced Routing Tables (BaRT) Algorithm, is described in U.S. patent application publication: US 2002/0002549 A1, Jan. 3, 2002. Other approaches are also set forth in J. van Lunteren, “Searching very large routing tables in wide embedded memory”, Proceedings IEEE Globecom, vol. 3, pp. 1615-1619, November 2001 and J. van Lunteren, “Searching Very Large Routing Tables In Fast SWAM,” IEEE International Conference on Computer Communications and Networks ICCCN 2001, Phoenix, Ariz., Oct. 15-17, 2001.) The cited references are included here as if in full.
Given an array of 0, 1, * entries and a key, a TCAM has the advantage of testing the key with all rules simultaneously and discovering all matches in only one processor cycle. However, the same key and array can be tested by tree approaches that can require smaller and cheaper hardware resources, perhaps one hundred times fewer transistors, to discover matches in tens of processor cycles. The optimal approach, be it TCAM, tree, or other, to finding which 0, 1, * rows of a ternary array fit a given key depends upon performance requirements.
One of the factors influencing performance is the size (number of rows and columns) of the ternary array. Any reduction in the number of rows and/or the number of columns has a positive effect on performance in that less storage is required and the search can be done in a much shorter time interval. Even though reducing the size of the ternary array is a desirable goal the prior art has not provided an apparatus and/or method (tool) that analyzes a ternary array and provides an array that is logically equivalent but smaller than the original array.
In view of the above there is a need for such a tool that is provided by the present invention.
SUMMARY OF THE INVENTION
The present invention describes a system and method for simplification of rule arrays.
It has been observed that rules devised by humans can contain hidden redundancies or might not be as compact as possible. This can lead to arrays that are several times larger than necessary.
In a preferred embodiment, the present invention includes preprocessing a rule array as described above and can be applied to simplify the job of classification or testing by a TCAM, tree, or other method. The present invention tests a rule array for two possible simplifications. The simplifications include replacement by a smaller array (fewer rows) that is logically equivalent to the original array. This first simplification finds logical redundancies in the rules. The second simplification is based upon reduction of the rule set, that is, replacements of subsets of two or more rules by single rules that are logically equivalent.
The invention includes a Redundancy Test Algorithm. It is assumed that N (>=2) Rules are labeled by an index i with i=0, 1, 2, . . . , N−1. Also, each rule is marked by a “valid bit” that is initially. The complexity of the algorithm is O(N^2), where N represents the number of entries in the array. Rule number i is redundant if there exists a rule number j having the properties:
1. Every bit position that is 0 in rule i is 0 or * in rule j 2. Every bit position that is 1 in rule i is 1 or * in rule j 3. Every bit position that is * in rule i is * in rule j
The pseudocode for an algorithm that systematically tests for redundancy is in Appendix A. Initially all rules have valid bits set to 1. After the Redundancy Test Algorithm runs, it is possible that some of the rules have valid bits set to 0, meaning that they can be deleted from the rule set without changing the logical application of the rules. Again, all rules in a tested set are assumed to have the same action.
The invention further includes a Reduction Algorithm that is applied to all the rules that still have the same action and priority and that have valid bit equal to 1 after application of the Redundancy Test Algorithm. It is assumed that N (>=2). Rules are labeled by an index i with i=0, 1, 2, . . . , N−1. The complexity of the algorithm is O(N^2). Rule number i and rule number j can be reduced to one logically equivalent rule if rule i and j have the properties:
1. Rules i and j are identical in every bit position except exactly one bit position.
The pseudocode for an algorithm that systematically tests for reductions is in Appendix B. Initially, all rules have valid bit set to 1. After the Reduction Algorithm runs, it is possible that some of the rules are changed and other rules have valid bit equal to 0, meaning that they can be deleted from the rule set without changing the logical application of the rules. All rules in a set tested by the Reduction Algorithm are assumed to have the same priority and action.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a block diagram of a communications network including the teachings of the present invention.
FIG. 2 shows a block diagram of a processor that executes the algorithms according to the teachings of the present invention.
FIG. 3 shows a flow chart of the Redundancy Test Algorithm according to the teachings of the present invention. The algorithm tests for redundancy in every entry of the matrix representing the rules.
FIG. 4 shows a flow chart for the Reduction Algorithm according to the teachines of the present invention. The algorithm tests each entry against the remaining entries in the matrix to determine entries to combine.
DETAILED DESCRIPTION OF INVENTION
Before describing details of the present invention some characteristics of the Rules matrix to which the invention is applicable will be discussed.
Each rule in the matrix can have one or more action attributes permit or deny could be an action attribute, as could be a rule that changes the Quality of Service designation of a packet). Two rules are said to intersect if at least one key fits both rules. Rules that intersect can have the property of priority as defined in U.S. Pat. No. 6,484,171, “System method and computer program for prioritizing filter rules”. Priority means that if a key fits two or more rules, then the rule with the highest priority value is enforced. The present invention pertains to sets of rules all of which have both the same action type and the same priority.
It can happen in enforcement of rules that the action is the critical outcome, not the knowledge of which particular rule fits among a set of rules with common priority and action. It can also happen that many rules in a ternary set have the same priority and the same action. Typically this is the case with many noninteresecting rules, but it can happen with intersecting rules as well. The present invention includes reduction of such sets of ternary rules with common priority and common action, provided only the action of the rule system matters.
It can also happen that by mistake some ternary rules are redundant. Suppose any key that fits ternary rule A must also fit ternary rule B, that A and B have the same priority, and that A and B have the same action. Then rule A is said to be included in rule B. The occurrence of rule A in the ternary rule set is pointless and A should be deleted. The present invention includes detection and correction of some such redundant ternary rule mistakes.
FIG. 1 shows a block diagram of communications network 100 in which the present invention is implemented. The communications network 100 includes a plurality of subnetworks (subnet) 106 connected by separate edge device 104 to the internet or other types of network 102 . The subnet 106 may be a wide area network, local area network, etc. The edge device may be a router bridge, server, etc. A database reduction system 104 ′ according to the teachings of the present invention is placed in each of the edge devices. It should be noted that the database reduction system 104 ′ may be placed in other parts of the network and not necessarily as shown in FIG. 1 . Therefore, its placement in the edge device is only exemplary and should not be construed as a limitation on the scope or teachings of the present invention.
The database reduction system 104 ′ includes a computer and algorithms that are executed on the computer. Turning now to FIG. 2 a block diagram of the computer 200 is shown. The logical components of computer 200 may include Random Access Memory (RAM) 202 , a Central Processing Unit (CPU) 204 , Read Only Memory (ROM) 206 , all connected by a Bus 208 . Also connected by a Bus 208 can be an Input/Output (I/O) adapter 210 and connected to the I/O Adapter can be a plurality of one or more devices 212 including devices handling packet flows. Within edge devices in hardware or software or a combination of hardware and software may reside instances of the present invention for the purpose of classification or filtration of packets. An instance of the present invention may use a combination of the logical components in the edge device.
Referring to FIG. 3 , shown is a flowchart 300 for the Redundancy Test Algorithm which tests a set of N rules, N being the number of Rules tested, labeled R 0 , R 1 , R 2 , . . . , RN−1. In principle, any rule might be redundant relative to some other rule, so all combinations must be checked. Initially, each rule is assigned a valid bit with value 1. Of course other values other than 1 could be assigned to the rules without deviating from the teachings of the present invention. When the algorithm ends, N rules are in a (generally) new list and the valid bit assigned to each rule in the new list is 0 or 1. Only rules with a valid bit equal to 1 need be tested by the Redundancy Test Algorithm in order to reach a generally smaller set of rules with the same action for any key as the original rule set. The algorithm begins at the start block 302 . An integer index i (corresponding to rule Ri) is initially set to 0, block 304 , and an integer index j (corresponding to rule Rj) is also initially set to 0, block 306 . In block 308 a test is performed, namely, “Does rule Rj have valid bit=0?” If yes, then the algorithm branches to block 314 . If no, then the algorithm branches to block 310 . In block 310 a test is performed, namely, “is j=i?” If yes, then the algorithm branches to block 314 . If no, then the algorithm branches to another test block 312 . Test in 312 asks “is no bit position that is equal to 0 in Ri equal to 1 in Rj AND is no bit position that is equal to 1 in Ri and equal to 0 in Rj AND is every bit position that is equal to * in Ri also equal to * in Rj?” If yes (this is the logical equivalent that rule Ri is redundant relative to rule Rj), then the algorithm proceeds to block 316 . If no, then the algorithm proceeds to block 314 . In block 314 the algorithm tests, “is j<N−1?” If yes, then the algorithm branches to block 318 . If no, then the algorithm branches to block 320 . In block 316 the valid bit of rule Ri is changed to 0, then the algorithm flows to block 320 . In block 318 the value of j is incremented to j+1, then the algorithm flows to block 308 . Block 320 tests, “is i<N−1?” If yes, then the algorithm branches to block 322 . If no, then the algorithm branches to block 324 . In block 322 the value of i is incremented to i+1, then the algorithm flows back to block 306 . In block 324 the algorithm ends.
Referring to FIG. 4 , shown is a flowchart 400 for the Reduction Algorithm which tests a set of N rules labeled R 0 , R 1 , R 2 , . . . , RN−1. In principle, any rule might be combined with any other rule to achieve a reduction, so all possibly combinations must be checked. Initially, each rule has a valid bit with value 0 or 1 assigned. In a preferred embodiment, this set is actually the output of the Reduction Test Algorithm and the rules with valid bit equal to 0 have already been deleted. When the algorithm ends, N rules are in a (generally) new output rule list and the valid bit of each rule in the output list is 0 or 1. Only output rules with a valid bit equal to 1 need be tested in order to reach the same logical result for any key as the original rule set. It should be noted the Reduction algorithm can be exercised as a standalone algorithm independent of the Redundancy algorithm.
Still referring to FIG. 4 , the algorithm begins at the start block 402 . An integer index i is initially set to 0, block 404 , and an integer index j is also initially set to 0, block 406 . In block 408 a test is performed, namely, “does rule Rj have valid bit=0?” If yes, then the algorithm proceeds to block 414 . If no, then the algorithm proceeds to block 410 . In block 410 a test is performed, namely, “is j=i?” If yes, then the algorithm proceeds to block 414 . If no, then the algorithm proceeds to another test 412 . Test 412 is “are all bit positions identical in Ri and Rj except exactly one bit position?” If yes, then the algorithm proceeds to block 416 . If no, then the algorithm proceeds to block 414 . In block 414 the algorithm tests, “is j<N−1?” If yes, then the algorithm branches to block 418 . If no, then the algorithm branches to block 420 . In block 416 the exceptional entry identified in block 412 is changed to * in rule Rj. The algorithm then flows to block 422 wherein the valid bit of rule Ri is changed to 0. The algorithm then flows to block 420 . In block 418 the value of j is incremented to j+1, then the algorithm flows to block 408 . Block 420 asks, “is i<N−1?” If yes, then the algorithm branches to block 424 . If no, then the algorithm branches to block 426 . In block 424 the value of i is incremented to i+1, then the algorithm flows back to block 408 . In block 426 the algorithm ends.
Having described the algorithms of the present invention, examples of their applications follows.
Here is an example of the application of the Redundancy Test Algorithm. Suppose there are 4 synthetic ternary rules with the same action as follows. Each has 25 bit positions. Initially the rule list might be as follows.
Rule ternary range valid bit 0 *00001110*100000*00011111 1 1 *00001110*100000*001011** 1 2 *00001110*100000*00011*** 1 3 *00001110*10000**00101*** 1
Note that R 0 is included in R 2 and R 1 is included in R 3 . Application of the Redundancy Test Algorithm results in the following new values for the valid bits.
Rule ternary range valid bit 0 *00001110*100000*00011*** 0 1 *00001110*100000*001011** 0 2 *00001110*100000*00011*** 1 3 *00001110*10000**00101*** 1
Because R 0 and R 1 are tagged with valid bit 0 , they would be dropped from the database of Rules.
Here is an application of the Reduction Algorithm to a set of 18 ternary rules from a real rule set. They all have the same priority and the same action (namely, the action is “permit”).
Rule ternary range valid bit 0 *00001110*100000*00011*** 1 1 *00001110*100000*00101*** 1 2 *00001110*100001*00011*** 1 3 *00001110*100001*00101*** 1 4 *00001110*100010*00011*** 1 5 *00001110*100010*00101*** 1 6 *00001110*100011*00011*** 1 7 *00001110*100011*00101*** 1 8 *00001110*001010*00011*** 1 9 *00001110*001010*00101*** 1 10 *00001110*001011*00011*** 1 11 *00001110*001011*00101*** 1 12 *00001110*010001*00011*** 1 13 *00001110*010001*00101*** 1 14 *00001110*001111*00011*** 1 15 *00001110*001111*00101*** 1 16 *00001110*010000*00011*** 1 17 *00001110*010000*00101*** 1
Application of the Reduction Algorithm results in the following new rules and new values for the valid bit of some old rules. R 0 merges with R 2 to form a new R 2 , R 4 merges with R 6 to form a new R 6 , then R 2 merges with R 6 to form a new R 6 , and so on.
Rule
ternary range
valid bit
0
*00001110*100000*00011***
0
1
*00001110*100000*00101***
0
2
*00001110*10000**00011***
0
3
*00001110*10000**00101***
0
4
*00001110*10001**00011***
0
5
*00001110*100010*00101***
0
6
*00001110*1000***00011***
1
7
*00001110*1000***00101***
1
8
*00001110*001010*00011***
0
9
*00001110*001010*00101***
0
10
*00001110*00101**00011***
1
11
*00001110*00101**00101***
1
12
*00001110*010001*00011***
0
13
*00001110*010001*00101***
0
14
*00001110*001111*00011***
1
15
*00001110*001111*00101***
1
16
*00001110*01000**00011***
1
17
*00001110*01000**00101***
1
A set of 1733 real rules was considered as a test set. A total of 1654 of the rules were special permisssion rules that had one priority (highest) and one action (permit). Therefore 79 of the rules were not treated. None of the 1654 special permission rules intersects with any other of 1732 rules. Applying the Redundancy Test Algorithm results in 20 of the 1654 special permission rules being declared “redundant” in enforcement of the rules. Checking the raw rules revealed that there actually was a logical error in them. The 20 rules are already redundant in the raw form. Then applying the Reduction Algorithm to the remaining 1634 special permission rules with valid bit 1 resulted in modification of some rules and deletion of others in multiple stages, the net reduction being from 1634 rules to 639 logically equivalent rules.
In summary, the result is that applying the present invention including the Redundancy Test Algorithm and the Reduction Algorithm to a real set of 1733 rules resulted in an equivalent set of 79+639=718 ternary rules. The ratio of 1733 to 718 is 2.4.
The Appendices A, B and C describe pseudocode and C language for implementing the invention described herein.
The foregoing is illustrative of the present invention and is not to be construed as limiting thereof Although exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teaching and advanced use of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims.
APPENDICES
Appendix A
Here is pseudo-code for an algorithm that systematically tests for redundancy. An equivalent flow chart for this algorithm is shown in FIG. 3 .
Redundancy Test Algorithm 1. Let i = 0 2. Let j = 0 3. If rule Rj has valid bit = 0, then goto 6 4. If j = i, goto 6 5. If no 0 in Ri is 1 in Rj AND no 1 in Ri is 0 in rule Rj AND every * in Ri is * in Rj, then make the valid bit in Ri 0 AND goto 7 6. If j < N−1, let j:=j+1, goto 3 7. If i < N−1, let i:=i+1, goto 2 8. END
Appendix B
Here is pseudo-code for an algorithm that systematically tests for reduction of the rule set. An equivalent flow chart for this algorithm is shown in FIG. 4 .
Reduction Algorithm 1. Let i = 0 2. Let j = 0 3. If rule Rj has valid bit = 0, then goto 6 4. If j = i, goto 6 5. If Ri and Rj are identical in every position except exactly one entry, then write * in that entry in Rj AND make the valid bit in Ri 0 AND goto 7. 6. if j < N−1, let j:=j+1, goto 3 7. If i < N−1, let i:=i+1, goto 2 8. END
Appendix C
The following includes C programs that enable logic equivalent to the Redundancy Test Algorithm and the Reduction Algorithm. In this code the symbol x was used to denote “don't care.”
****
C code that implements the Reduction Algorithm appears below.
********************************************************************
*
Ternary Compare
*
*
This program compares a set of rules to determine if there is
*
redundancy between pairs of rules and whether rule sets can
*
be reduced by replacing a bit value with a “dont-care” symbol.
*
All rule combinations are attempted and when unification occurs
*
the rules are all re-tested to ensure that all unifications
*
are found.
*
*
Input: a text file with ternary compare rules arranged in fields
*
as in the following example:
*
*
rule
77 : x01011111 x001110 x0001 1xxx
*
*
Note that there are no leading characters in the file.
*********************************************************************/
#include <stdio.h>
main(int argc, char **argv){
int i=0, j=0, num=0, loc, slen, rule[2048], resultCount=0, verbose = 0;
char vector[2048][64], valid[2048], dataFileString[128];
char s2[32], s3[32], s4[32];
FILE *dataFile, *resultFile;
if (argc < 2){
printf(“Usage: tc InputRuleFile\n”);
exit(−1);
}
/* open the input file */
strcpy(dataFileString, argv[1]);
dataFile = fopen(dataFileString, “r”);
if (dataFile == NULL){
printf(“Could not open %s\n”, dataFileString);
exit(−1);
}
/* open the output file */
strcat(dataFileString, “.result”);
resultFile = fopen(dataFileString, “w”);
if (resultFile == NULL){
printf(“Could not open %s\n”, dataFileString);
exit(−1);
}
/* initialize valid bits */
for(i=0; i<2048; i++)
valid[i] = 1;
/* print out Notes */
fprintf(resultFile, “Notes:\n‘*’ indicates a compression, so that it can be\n”);
fprintf(resultFile, “distinguished from the original dont-care ‘x’\n”);
fprintf(resultFile, “\nThe result index is relative to the position in the
input \n”);
fprintf(resultFile, “vector file, not the rule index. \n”);
printf(“Notes:\n‘*’ indicates a compression, so that it can be\n”);
printf(“distinguished from the original dont-care ‘x’\n”);
printf(“\nThe result index is relative to the position in the input\n”);
printf(“vector file, not the rule index. \n”};
/* read vectors from file */
while (fscanf(dataFile, “rule %d : %s %s %s %s\n”,
&rule[num], vector[num], s2, s3, s4) != EOF){
strcat(vector[num], s2);
strcat(vector[num], s3);
strcat(vector[num], s4);
num++;
if (verbose) if (num > 100) break;
if (verbose) printf(“the string is %s\n”, vector[num−1]);
}
printf(“Read %d vectors, processing...\n\n”, num);
/* start redundancy test algorithm */
resultCount = 0 ;
printf(“starting redundancy test algorithm...\n”);
for(i=0; i < num; i++){
for(j=0; j < num−1; j++){
if (!valid[i]) continue;
if (i == j) continue;
if (redundantCheck(vector[i], vector[j])){
valid[i] = 0;
printf(“%s is contained in \n%s (%d, %d)\n”,
vector[i], vector[j], rule[i], rule[j]);
resultCount++;
break; /* go to next Ri */
}
}
}
printf(“found %d redundancies\n\n”, resultCount);
/* start reduction algorithm */
resultCount = 0;
printf(“starting reduction algorithm...\n”);
fflush(stdout);
for(i=0; i < num; i++){
if (!valid[i]) continue;
/* this vector has already been removed
*/
/* so there is no need to test it
*/
for(j=i+1; j<num−1; j++){
if (!valid[j]) continue;
/* this vector has already been removed
*/
/* so there is no need to test it
*/
loc = findLocation(vector[i], vector[j]);
if (loc >= 0){
/* found an off-by-one vector pair */
if (verbose)
printf(“\trule %d: %s %s −> ”, rule[i], vector[i],
vector[j]);
vector[i][loc] = ‘*’;
valid[j] = 0;
i = −1;
/* loop will increment, making i==0 */
break;
/* break out of inner loop */
}
}
}
printf(“completed. Writing results...\n”);
slen = strlen(vector[0]);
/* printf(“\n\nResults:\n---------------\n”); */
fprintf(resultFile, “\n\nResults:\n---------------\n”);
for(i=0; i < num; i++){
if (valid[i]){
/* printf(“%4d) %s\n”, i, vector[i]); */
fprintf(resultFile, “%4d) %s\n”, i, vector[i]);
resultCount++;
}
}
printf(“\nCompressed %d vectors to %d, compression factor: %5.2f\n”,
num, resultCount, (float)num/(float)resultCount);
fprintf(resultFile,“\nCompressed %d vectors to %d, compression factor: %5.2f\n”,
num, resultCount, (float)num/(float)resultCount);
}
/*
* determine if Ri is redundant with Rj
*/
int redundantCheck(char *Ri, char *Rj){
int k, len;
len = strlen(Ri);
for(k=0; k< len; k++){
if ((Ri[k] == ‘0’)&&(Rj[k] == ‘1’)) return 0; /* return if we prove that
*/
if ((Ri[k] == ‘1’)&&(Rj[k] == ‘0’)) return 0; /* it is not redundant
*/
if ((Ri[k] == ‘x’)&&(Rj[k] != ‘x’)) return 0;
}
return 1;
}
/*
* find location of single difference
*/
findLocation(char *Ri, char *Rj ){
int i,j, stringLength, location;
stringLength = strlen(Ri);
if (stringLength != strlen(Rj)){
printf(“Error in the string lengths!\n”);
exit(−1);
}
/* look for the first difference */
for(i=0, location=0; i< stringLength; i++)
if (Ri[i] != Rj[i]){
location = i;
break;
}
/* if there is a second difference, return with no result */
for(i++; i< stringLength; i++)
if (Ri[i] != Rj[i])
return(−1); /* no result found here */
return(location); | A system for reducing the size of a database includes a memory in which the database configured in a ternary matrix array structure is stored. A processor executing at least one reduction algorithm scans the database tagging superfluous entries that are subsequently deleted. The tagging and deleting are done in such a way that the logical contents of the original database is unchanged, even though the size of the database is reduced. | 6 |
FIELD OF THE INVENTION
[0001] The invention relates to a method and a device for determining a border of a target region in medical images, as well as determination of physiological parameters by utilizing the determined border of the target region. More specifically, the invention relates to determination of heart physiological parameters based on real ultrasonic image data.
BACKGROUND OF THE INVENTION
[0002] Medical imaging has become an indispensable part of modern medical treatment, and the application of the medical imaging runs through the whole clinical work. The medical imaging is widely used in disease diagnosis, and further plays an important role in the aspects of planning, implementing, and curative effect evaluating of surgeries, radiotherapies and the like. At present, medical images can be grouped into two kinds, namely anatomical images and functional images. The anatomical images mainly describe human body's morphological information including X-ray transmission imaging, CT, MRI, US and so on.
[0003] Particularly, in the aspect of modern diagnosis and treatment of heart diseases, quantitative analysis of the medical images by utilizing the computer technology has become an important technical improvement direction. Such method can increase the objectivity of diagnosis, easier to be grasped and operated, and can further reduce the dependence on experience of a reader of the images, thus avoids judgment difference among different readers. Further, in this art, it is desired to obtain quantified physiological parameters of heart, such as ventricular volume, myocardial mass, cardiac chamber wall thickening, heart ejection fraction (EF value) and the like, more accurately based on the image photographing sequence of the heart. Accurate obtainment of the heart ejection fraction has an important significance, since the heart ejection capability can be estimated according to the heart ejection fraction, which is an important parameter for judging the cardiac function.
[0004] 3D ultrasound is a non-destructive imaging examination technology having advantages of high imaging speed and low cost during detecting the heart diseases, and thus has a widest range of applications in the aspects of diagnosis and treatment of the heart diseases. Analysis of volume of a cardiac chamber, ejection fraction, myocardial volume and mass, and other physiological parameters from a 3D ultrasonic image is an important basis for diagnosis. However, as an echocardiogram contains a lot of noise and the endocardium of the cardiac chamber and the edge of a myocardium are irregular (in particular in the cases of a cardiac chamber and a myocardium with pathological changes), the relevant quantitative calculation thereof becomes difficult. Particularly, how to accurately obtain the endocardial border and how to accurately make calculation regarding a heart with irregular changes are difficult. The art has worked for improving the accuracy and operability in obtaining the physiological parameters from the ultrasonic images.
[0005] At present, it is relatively common in clinical use to apply a method for determining a heart ejection fraction (EF value) which includes defining some control points in an interactive way, and modeling the cardiac chamber using a series of simulated geometric shapes, so that the result is very inaccurate.
[0006] Many patent publication documents teach adopting the above means. For example, JP2002085404, entitled “ultrasonic imaging processor”, teaches dividing a cardiac chamber into 20 segments to make approximate statistics of the volume thereof. EP123617 teaches using a segmented curve to describe a cardiac chamber. JP2008073423 teaches obtaining an approximate cardiac chamber by interpolation of reference outlines from a set of more than 50 images. EP1998671 (A1) teaches pointing out several control points by utilizing a mouse and matching them with a template, so as to achieve the automatic segmentation. EP2030042 (A1) teaches manually marking a few control points and combining them with a template having being trained, to obtain an endocardium.
[0007] In the conventional technologies, it is common to process data by utilizing a prior model, to obtain physiological parameters which are related to the volume of heart, myocardium and the like, which have complex shapes.
[0008] The prior model is a model based on statistics, indicates that a data set to be analyzed obeys certain unknown probability distribution and has a definite relationship with the data set of a known sample. In order to achieve the unknown probability distribution, the probability distribution obeyed by the known sample needs to be calculated on the data set of the known sample; and such probability distribution or the distribution parameter, which could be calculated in advance, is called as the prior model.
[0009] Generally, compared with a case of the normal cardiac chamber, a heart with the pathological changes is not a cardiac chamber which can be estimated by using the above model any more. The cardiac chamber of the heart with the pathological changes has a shape with unpredictable changes, and the endocardium is also irregular, due to for example, a tumor occupying, a ventricular aneurysm, and the cardiac chamber wall being thickened. The shape changes of the cardiac chamber result in reduction of ejection function, valvular dysfunction and other symptoms.
[0010] In the aspect of clinical applications, a prior shape model of the cardiac chamber is obtained by calculation of multiple frames of images in advance, then the prior shape model obtained is contrasted with an approximate geometric model of the cardiac chamber on the current image and further corrected to obtain the cardiac chamber on the current image. However, since such prior model is obtained by calculation according to the normal heart, in the actual clinical application, it is difficult to obtain accurate results when images of a heart with pathological changes are treated by such method.
[0011] Please refer to “Convex spatio-temporal segmentation of the endocardium in ultrasound data using distribution and shape priors”, written by Hansson M, Fundana K, Brandt S. S, Gudmundsson P., and published on “Biomedical Imaging: From Nano to Macro”, 2011, Page(s): 626-629. The document proposes making segmentation of a cardiac chamber by a method combining machine learning with morphology, particularly, it teaches establishing a probability model by using Rayleigh distribution as the basis, and using the model established to calculate the probability that the current region is inside the cardiac chamber and the probability that the current region is outside the cardiac chamber. Then, such model is trained by processing a lot of ultrasonic image data, to obtain estimated values of various parameters in the probability model. Finally, the probability calculated by the probability model is used as a priori, which is combined with the prior morphological model of the cardiac chamber to segment the central chamber on new images.
[0012] Please refer to “A level set approach for shape-driven segmentation and tracking of the left ventricle” written by Paragios N., and published on “Medical Imaging”, 2003, Page(s): 773-776. In the method provided by this document, a level set algorithm is adopted chiefly in a segmentation algorithm of left ventricle, along with using a lot of prior knowledge, i.e., the correct segmentation result of the left ventricle is known. A limitation region and a speed function of the level set are designed by using prior experience combined with the characteristics of the image. Thus, the purpose of segmenting the left ventricle is achieved.
[0013] Please refer to “Combining snakes and active shape models for segmenting the human left ventricle in echocardiographic images”, written by Hamarneh G, Gustaysson T., and published on Computers in Cardiology 2000 Digital Object Identifier: 10.1109/CIC.2000.898469 Publication Year: 2000, Page(s): 115-118. A method is proposed by using a snake model to segment the left ventricle. According to the method, a large number of cardiac ultrasonic images including left ventricle should be manually traced by medical experts to achieve a training sample, and then the data are used to define a series of discrete cosine transform coefficients (DCT coefficients). When a new left ventricle image is segmented by the snake algorithm, the discrete cosine transform coefficients of the snake coordinates are initialized, then the discrete cosine transform coefficients from the prior experience are taken as external forces to iterate an active contour till the minimization of energy.
[0014] Other relevant patent documents, such as the Chinese patent with the publication number of CN1777898A and the application number of 200480010928.2, entitled “Non-invasive volume determination of left ventricle”, relate to processing of MR images and estimating of LV (left ventricle) volume based on the contour of an endocardium in a 3D image of heart. The contours are manually traced or achieved in a semi-automatic manner. The LV volume is estimated by intensity changes in the region surrounded by the contour. The document teaches marking border points by manually tracing based on the difference between image pixels (namely image gradient), thus such method is likely to be affected by imaging noise and achieve inaccurate results. Further, when the contour determined is directly applied to other time frames, deviations would be introduced even though automatic correction is performed.
[0015] As for the conventional technologies for myocardial measurement, a myocardial segmentation method which is more frequently used in clinical use at present is based on the analysis of speckles and texture. This method also includes defining some control points in an interactive manner and obtaining an approximate myocardial contour by curve fitting method, therefore the method also achieves inaccurate results. Similarly, a prior shape model of myocardium is obtained by calculating multiple frames of images in advance, and then it is contrasted with an approximate geometric model of the myocardium on the current image and further corrected to obtain the myocardium on the current image. However, as mentioned above, the prior model is obtained by calculating images of the normal heart, therefore in the actual clinical application, it is also difficult to obtain accurate results when images of a heart with pathological changes are treated by such method.
[0016] CN101404931A (application number of CN200780009898.7), entitled “Ultrasonic diagnosis with quantification of myocardial function”, teaches firstly manually setting control points, further connecting the control points by using a curve according to image gradient, and thus achieving the purpose of approximate tracing.
[0017] CN101454688A (application number of CN200780018854.0), entitled “Quantification and display of cardiac chamber wall thickening”, discloses a method of achieving distances, changes in wall thickness and strain at specified locations of the myocardium by speckle tracking. No result of the single myocardium is obtained either. The technology determines the endocardial border by using the image gradient. If the image noise is increased, the results become inaccurate. As for the epicardium border, there is no definite gradient, thus, when the epicardium border is determined automatically, dropouts in the border often occur, and the inaccuracy is further caused. Thus, the patent document provides a tool, by which two borders are manually adjusted at the beginning and the end of a cardiac cycle, points which need to be tracked are automatically set between the two borders such that the points are positioned on the myocardium, then the pixels around each point are recorded as speckle patterns, the maximum correlation block matching is performed between the speckle patterns of different frames, and the motion of each point can be tracked. Such speckle tracking is easily to be affected by the noise.
[0018] Please refer to a related paper entitiled “Segmentation of the full myocardium in echocardiography using constrained level-sets”, written by Alessandrini, M. Dietenbeck, T. Barbosa, D. D'hooge, J. Basset, O. Speciale, N. Friboulet, D. Bernard, O., and published in Computing in Cardiology. 2010. This paper discloses combination of a traditional level-set method and a prior morphological method, specifically, two attributes namely level-set energy and morphological energy are marked on the points in an image, and two energy attribute values are finally summated in a weighted manner to obtain an energy value of each pixel point. During initialization of the algorithm, six points are manually marked on the image (five points are located on epicardium and one point is located on the endocardium), evolution functions with the value of 0 are respectively established for points on the endocardium and points on the epicardium, then the values of two evolution functions are calculated for all the points on the image, and two evolution curves are respectively obtained. A myocardial layer is segmented.
[0019] Please refer to a related paper entitled “Level-set segmentation of myocardium and epicardium in ultrasound images using localized Bhattacharyya distance”, written by Alessandrini, M. Friboulet, D. Basset, O. D'hooge, J. Bernard, O., and published in Ultrasonics Symposium (IUS). 2009. This paper discloses an algorithm which uses Bhattacharyya distance based on Rayleigh distribution as energy constraint of the level-set algorithm during evolution. During initialization of the algorithm, six points are manually marked on the image (five points are located on the epicardium and one point is located on the endocardium), and the evolution functions are respectively established for the points on the endocardium and the points on the epicardium. The myocardial layer is segmented.
[0020] Please refer to a related paper entitled “Detection of the whole myocardium in 2D-echocardiography for multiple orientations using a geometrically constrained level-set”, written by T. Dietenbeck, M. Alessandrini, D. Barbosa, J. D'hooge, D. Friboulet, O. Bernard., and published in Medical Image Analysis. 2011. This paper teaches additionally using a thickness factor as an energy constraint of level-set, on the basis of the technical solution taught by the above paper entitled “Segmentation of the Full Myocardiumin Echocardiography Using Constrained Level-Sets”. This method aims at preventing fusion of the evolution curve of the endocardium and the evolution curve of the epicardium, which could occur during the evolution process caused by the same factor. In order to ensure the correct application of the algorithm on images with a short axis, and a long axis etc., before the use of the algorithm, two points should be manually designated to determine the position of tricuspid valve, thereby ensuring the correct execution of the algorithm. The myocardial layer is segmented.
[0021] Compared with the normal myocardium, a myocardium with pathological changes has expansionary, shrinkable, hypertrophy and other pathological changes, which finally affect shrinkability, specifically represented as changes in elastic deformation parameters. In the aspect of geometry, compared with the normal myocardium, the myocardium with pathological changes also has differences, and then an irregular border may be produced.
[0022] Therefore, in the art, it is urgent to further improve the method of obtaining the heart-related quantified parameters by utilizing image processing, so as to further improve measurement precision and operability of the method.
SUMMARY OF THE INVENTION
[0023] In view of the defects in the prior art, the invention aims at seeking a more effective and accurate image processing and calculating device and a method based on the current medical imaging technology, to improve and enhance the accuracy of physiological parameters which are related to the volume of a cardiac chamber, ejection fraction, myocardial volume and mass, and the like, and further to assist in timely achieving correct diagnosis in clinical treatment process.
[0024] The first aspect of the invention provides a device for determining physiological parameters based on 3D medical images. The device comprises: a border determining unit, which is used for determining a border of a target region; and a volume determining unit, which is used for determining the total number of voxels in the target region according to the border determined, and calculating a volume of the target region according to a specified relation formula.
[0025] The second aspect of the invention provides a device for determining physiological parameters based on the first aspect, wherein the volume determining unit calculates the volume of the target region with the total number of the voxels and the distances between the voxels as parameters.
[0026] The third aspect of the invention provides the device for determining the physiological parameters based on the first or the second aspects, wherein the volume determining unit is set to determine the total number of the voxels in the following way: determining the total number of pixels in a target region in image of each slice, based on two-dimensional border of each slice in a series of slices in a frame of the 3D medical image; and calculating the total number of the voxels of the target region of the frame of the 3D image, based on the total number of the pixels in the target region in the image of each slice.
[0027] In the fourth aspect of the invention, the device is further used for determining the volume of the cardiac chamber, wherein the target region is a region of the cardiac chamber, and the volume determining unit carries out the following processing on the images of each slice:
[0028] (1) counting a total number of pixels num1 inside an endocardial border;
[0029] (2) calculating a weighted value with respect to the number of the pixels on the endocardial border according to gray level gradient, and multiplying the number of the pixels on the endocardial border by the weighted value, so as to obtain a total number of weighted pixels on the endocardial border; and
[0030] (3) calculating the volume of the cardiac chamber according to the resolution of the image and the numbers of the pixels which are respectively determined by calculations in the above two items.
[0031] The fifth aspect of the invention further provides an EF value calculation unit carrying out the following processing steps: finding a maximum value and a minimum value during each cardiac cycle according to the volume of the cardiac chamber, which is obtained by calculation, and further calculating an EF value.
[0032] The sixth aspect of the invention provides the device for determining the physiological parameters based on the fourth aspect, wherein the number of the pixels on the endocardial border is calculated by using the following formula:
[0000]
num
2
=
∑
i
=
1
N
l
i
l
max
-
l
min
[0033] wherein, N is the total number of the pixels on the border, l max is the maximum value of gray level gradient magnitude of the pixels on the border, l min is the minimum value of the gray level gradient magnitude of the pixels on the border, and l i is the gray level gradient magnitude of each pixel on the border; and
[0034] the volume of the cardiac chamber on a frame of the images is calculated by using the following formula:
[0000]
V
=
(
∑
i
=
1
S
(
num
1
i
+
num
2
i
)
)
×
sx
×
sy
×
sz
[0000] wherein, S is total number of the slices on the frame of the image, num1 i is the number of the pixels inside the endocardial border on each slice, num2 i is the number of the pixels on the endocardial border on each slice, and sx, sy and sz are distances between the central points of the voxels in x, y and z directions of the frame of the image, and the unit is millimeter (mm).
[0035] The seventh aspect of the invention provides the device for determining the physiological parameters based on the sixth aspect, further, the EF value is calculated by using the following formula:
[0000]
EF
=
V
max
-
V
min
V
max
[0036] wherein, the EF value is calculated during each cardiac cycle in an image time sequence, V max is the maximum value of the volume of the cardiac chamber on each frame of the image during the cardiac cycle, and V min is the minimum value of the volume of the cardiac chamber of each frame of the image during the cardiac cycle.
[0037] The eighth aspect of the invention provides the device for determining the physiological parameters based on the fourth aspect, the device is used for determining myocardial volume, wherein the volume determining unit carries out the following processing steps on the image of each slice:
[0038] (1) counting the number of the pixels num1 inside the border obtained according to a marked myocardial region;
[0039] (2) obtaining a weight value with respect to the pixels on the border according to the gray level gradient, so as to apply to the number of the pixels on the border; and
[0040] (3) calculating the myocardial volume according to the resolution of the image and the number of the pixels determined in the above two items.
[0041] The ninth aspect of the invention provides the device for determining the physiological parameters based on the fourth aspect, wherein the unit myocardial volume is calculated by using the following formula:
[0000]
num
2
=
∑
i
=
1
N
l
i
l
max
-
l
min
[0042] wherein, S is a total number of the slices on the frame of the image, num1 i is the number of the pixels inside the respective myocardial border on each slice, num2 i is the number of the pixels on the unit myocardial border on each slice, and sx, sy and sz are distances between the central points of the voxels in x, y and z directions of the frame of the image, and the unit is millimeter (mm).
[0043] The tenth aspect of the invention provides the device based on the eighth or the ninth aspects, which further provides a myocardial mass calculation unit which carrying out the following processing steps:
[0044] calculating myocardial mass according to the density obtained by clinical trials.
[0045] The eleventh aspect of the invention provides the device based on the above aspects, wherein the border determining unit differentiates the border of the target region according to the physical quantitative properties reflected by tissue distribution in the medical image, and the device comprises:
[0046] an interactive unit, by which an operator can select the target region on the medical image;
[0047] a threshold setting unit, which determines threshold values of the physical quantitative properties in the target region selected; and
[0048] a threshold segmentation unit, which segments a region to be analyzed, at least containing part of the target region, into sub-regions; and compares the average parameter values of the physical quantitative properties of each sub-region with the threshold values, and marks each of the sub-regions according to comparison results.
[0049] The twelfth aspect of the invention provides the device based on the above aspects, wherein the physiological parameters to be determined are selected from: volume of each cardiac chamber, a total volume of the cardiac chambers, a heart ejection fraction, myocardial volume and myocardial mass.
[0050] The thirteenth aspect of the invention provides a physiological parameter quantitative calculation method based 3D medical images, comprising the following steps:
[0051] determining a border of a target region; and
[0052] determining the total number of voxels of the target region according to the border determined, and calculating the volume of the target region according to a specified relation formula.
[0053] The fourteenth aspect of the invention provides the physiological parameter quantitative calculation, which further comprises: calculating the volume of the target region with the total number of the voxels and the distances between the voxels as parameters.
[0054] Another aspect of the invention is based on the physiological parameter quantitative calculation method in the above aspects, wherein the method further comprises differentiating the border of the target region according to the physical quantitative properties reflected by tissue distribution in the medical image, and includes the following steps:
selecting the target region, setting threshold values of the physical quantitative properties in the target region, segmenting the region to be analyzed, at least containing part of the target region, into sub-regions, and comparing the average parameter values of the physical quantitative properties of each sub-region with the threshold values, and marking each of the sub-regions according to comparison results.
[0059] The key point of the invention is that, the total number of the voxels of the target region is determined according to the border of the target region obtained according to the medical image, and the volume of the target region is further calculated based on the total number of the voxels according to the specified relation formula.
[0060] The object of the invention is to provide an intuitive and practical solution for solving the problems. The inventor notices that, as the heart, in particular the heart with pathological changes, not only has a very complex shape, but also relates to many irregular changes. On the other hand, in the present field, it is common to calculate the volume of cardiac chamber and myocardium, and an ejection parameter (EF) obtained based on the volume of the cardiac chamber with the help of a prior model or a simulated approximate method in the art, for example, a method of converting the volume calculation of the cardiac chamber to the volume calculation of a cone, so that the complex calculation processing could be avoided. However, the above modeling method is not suitable for the heart with pathological changes, so further improvement is still desired for clinical application.
[0061] Therefore, according to the invention, the total number of the voxels of the target tissue is determined based on an accurate 3D border obtained; and further, the total number of the voxels and the distances between the central points of the voxels are directly used as the parameters for obtaining the physiological parameters, such as the volume of the cardiac chamber, the heart ejection parameter, the myocardial weight and the like. The more intuitive explanation is that, the one could directly fills a container with liquid and then pours the liquid into a measuring cup to determine the volume of the container, rather than performing complex calculation from the perspective of geometry, based on the inspiration of volume calculation against the complex container.
[0062] Based on the above idea, similarly, the inventor combines the resolution characteristic of an imaging device with the computer technology, and the difficult problems in the art can be unexpectedly solved in a simple and clear way from the direction which is never considered in the art. The invention is more suitable for accurately determining the relevant parameters of the heart with pathological changes, is more targeted in clinical application and can further improve the accuracy and reliability of measurement.
[0063] The invention further provides a more specific heart-related physiological parameter calculation method, which is effective in calculating of the volume of the cardiac chamber, the heart ejection parameter, the myocardial weight and the like.
[0064] Based on the above aspects, the invention further results in advantages. In the aspect of quantifying the heart physiological parameters based on image processing, generally, only left ventricle is researched in the art, and the “ejection fraction” of the heart typically refers to the capability of the left ventricle ejecting blood into aorta, thereby representing the cardiac function. However, those skilled in the art are easy to understand that changes in function of other cardiac chambers will certainly also affect the EF value—the cardiac function. Actually, in the general situation, only the left ventricle is researched, because calculations relating to shapes and the volume of other ventricles involve more factors which would cause difficulty in calculation. However, due to the complexity and precision of the heart, for clinical medicine, it is very important to grasp more comprehensive data of different ventricles and cardiac chambers. The image processing method and the device of the present invention not only can effectively obtain the border, the volume and the ejection fraction of the left ventricle, but also are suitable for various ventricles, cardiac chambers and myocardium.
[0065] The solution of the invention for solving the problems provides a calculating and processing method and a device with clear physical significance and simple and effective algorithm, and the method and the device are particularly suitable for processing the special situations of various hearts with pathological changes in clinical art, and can improve the objectivity and accuracy in image data processing. Thus, the present invention has important application value and improvement for medical image processing technologies, in particular to cardiac image processing.
[0066] In addition, the above aspects of the invention can also be combined with other more effective target region defining device and method of the invention, so as to obtain the better technical effects. Specifically, the present invention further relates to: setting threshold values of parameters with respect to quantitative characteristic of a typical region in the target region, such as a partial region at the middle part of the target region, based on the quantitative characteristic reflected in the image by a physical nature of tissue distribution of an imaging object; determining results of comparing the threshold values with each of the sub-regions through the thresholding segmentation method, then grouping all the sub-regions into two types so as to differentiate the border of the target region on the image.
[0067] Preferably, the gray level of pixels or voxels is used as the quantitative characteristic. The average gray level is a characteristic measurement way with relatively high computing speed. In addition, the gradient distribution of the region can also be considered being another simple and efficient way for characteristic measurement.
[0068] The object of the above aspects of the present invention is to determine the border of the target region of the medical image by adopting a more accurate and effective method. When the present invention is applied to processing real 3D ultrasonic medical images, more accurate quantified physiological parameters can be obtained. The real 3D ultrasonic medical image refers to a 3D image which is directly generated by a 3D ultrasonic probe. In the ultrasonic 3D image, the determination of the endocardial border or the like has an important significance in the aspect of determining the heart-related physiological parameters.
[0069] More specifically, the present invention utilizes the computer technology to extract the border of the interest tissue from the digitized image. The pixels or the voxels around the border of the tissue of interest have an obvious contrast, but the border will become unclear due to the influence of granular noise. The inventor specifically investigates the characteristics of the pixels in the image, and arranges cells or sub-regions in the region to be analyzed, wherein such cells are assumed as “cell filled with pixels”, since it is filled with the inherent pixels for filling the sub-regions at the minimum basic cell. An investigation point is arranged in the region to be analyzed, and a circular or oval sub-region around the point is a cell or “cell filled with pixels”. The sub-regions are mutually overlapped, and the distribution characteristic of pixel values or voxel values in each sub-region is analyzed to deduce a fixed or non-fixed threshold value. Each pixel or voxel in the region around each investigation point is marked according to the threshold value, to obtain the tissue region of interest, and the border thereof is the border of the tissue of interest. The border of the tissue region of interest could be further refined by the following manner: setting investigation points on the tissue region which is well marked by using the designed algorithm again, and further analyzing the distribution discipline of the pixel values or the voxel values with circular or oval regions with different scales or sizes.
[0070] Specifically, the present invention relates to a border differentiating way utilizing the computer technology, and includes: selecting a position generally at the center of a region by an operator according to his experience, directly through the characteristics of different regions in relevant images, basing on the fact that physical properties of tissues such as the cardiac chambers and myocardium in the image are different and the fact that the tissue characteristics reflected in the medical image are different; determining the physical properties, such as average value of the gray level, gradient value and the like, of the region by utilizing the computer technology; and comparing the value obtained with the threshold value, so as to differentiate the region and the border as two groups, namely to achieve the effect of binarization of the image, and thus to differentiate the border. This differentiation way is more objective and accurate, since it could avoid the limitation of segmenting the cardiac chamber and the myocardium by using the prior model.
[0071] The above description does not intend to limit the present invention to any theoretical limitation, and is only illustrated for enabling those skilled in the art to understand the invention more easily.
[0072] Other objects, features, and characteristics of the present invention will become apparent upon the consideration of the following description with reference to the accompanying drawings, all of which form a part of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0073] In order to understand the invention more completely, please refer to the following description and the drawings, in which:
[0074] FIG. 1 is a schematic diagram showing result of approximate cardiac chamber segmentation by using an image processing device of a typical conventional technology;
[0075] FIG. 2 illustrates that a target cardiac chamber is interactive selected in an embodiment of the invention;
[0076] FIG. 3A shows the border of the cardiac chamber, marked by the method of the invention;
[0077] FIG. 3B is a schematic diagram of a cardiac chamber volume changing curve of all frames in a time sequence, wherein the maximum volume V max and the minimum volume V min of each frame of the images during each cardiac cycle can be seen from the diagram; and
[0078] FIG. 4 is a flow diagram of a specific embodiment of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0079] The border processing regarding a tissue or region (target region) of interest, proposed by the invention, can have a variety of different applications. The description of specific embodiments is provided so as to assist those skilled in the art in understanding the invention, and should not construct any limitation to the present invention.
[0080] In the description of the specific embodiments, the analysis is mainly performed by taking pixel gray level as a physical quantitative property. The present invention can also apply other suitable physical quantitative properties.
[0081] In one embodiment, the border processing of the invention comprises the following steps.
[0082] 1. Firstly, a series of slices of a medical image is divided into a series of circular regions which are mutually overlapped, as small sub-regions covering a region to be analyzed, and the regions are defined as cells considered as the cells filled by pixels of the image because the cells are filled with the pixels of the image. The divided circular regions cover the whole slice. The quantitative characteristic is calculated on each circular region according to a pixel gray level value, a threshold value is determined; then all the cells are preliminarily marked according to the threshold value, namely, all the cells are differentiated according to the threshold value.
[0083] 2. One region or a plurality of communicated regions are obtained by the preliminary marking, the regions of interest (ROI), that is, the target regions, are then integrated for further processing, namely only the communicated region containing the point clicked by a mouse from an operator is maintained, while other regions are discarded, or the other regions are unmarked. Thus, a region resulted by the preliminary segmentation is obtained.
[0084] 3. After the region resulted from the preliminary segmentation is obtained, a refining treatment is further performed on the border. Firstly, the border of the region after segmentation is marked out independently, then pixel filling cells are arranged on the border, wherein the pixel filling cells are set to cover smaller areas, which can be sized half of the pixel filling cells in the first step, and still need to be mutually overlapped. Similarly, the quantitative characteristic, such as average gray level or gradient and the like, is calculated on the regions, and the threshold value is obtained; then all the pixel filling cells are marked according to the threshold value, and an “or” operation is performed between the marked cells and the region resulted from the preliminary segmentation, so as to obtain a refined region result by merging.
[0085] In addition, further refining treatment can be performed, for example:
[0086] The operator repeats step 3 according to clinical needs, and the borders can be further refined by further reducing the size of the pixel filling cells till a satisfactory result is obtained.
[0087] In addition, a final border refining treatment can be directly performed on three-dimensional data. The so-called three-dimensional data are obtained by accumulating the above slices. Similarly, the obtained borders of the slices are accumulated in the 3D data to represent as a curved surface. Voxel filling cells are arranged on the curved surface, and set the same as in the step 3 which is executed at the last time, namely, the voxel filling cells have the same radius and still need to be mutually overlapped. Similarly, the quantitative characteristics are calculated according to the pixel gray level value on these regions, the threshold value is obtained; then all the pixel filling cells are marked according to the threshold value, and the “or” operation is performed between the marked cells and the region resulted obtained in the step 3 executed at the last time, so as to obtain the refined region results by merging.
[0088] As for the processing of the border of a cardiac chamber, it is basically the same as described in the above, except that the following processing needs to be further made in step 2:
[0089] (1) The processing steps of preliminary marking in slices are the same as that described above, except that only a gray level average value is observed in the step of selecting a region of the cardiac chamber.
[0090] (2) A preliminary segmented region is obtained in combination with the region of interest clicked by the mouse from the operator, and the operation is the same as that will be described later in detail, that is, separating the region containing the point clicked by the mouse independently by using eight communicated adjacent regions.
[0091] (3) On the region obtained in step 2, the border is marked out independently, then the border is divided into a series of mutually overlapped circular regions, with the centers of circles being points on the border and the radius of half of the radius of the circular regions in the step 1. The average value of the pixel gray level value and the average value of the pixel gray level gradient magnitude on each circular region are calculated. Two threshold values are obtained by calculating the average values of the values:
[0092] Wherein, “n” is the number of the circular regions. Then, the gray level average value and the pixel gradient magnitude average value of each circular region are checked. The gray level average value reflects the average value of gray level average value; the gradient magnitude average value reflects the average value of gradient magnitude average value; the changing amount of the pixels in the region, which reflects the changing amplitude of the pixels in the region, is analyzed as follows, with respect to the border, the amount will become large, while in the case that the amount of a region is smaller than the amount of the border, this region is inside the border and should be marked out, based on the determination condition that the gray level average value of a certain sub-region is smaller than the threshold value of the gray level average value, and the gradient magnitude average value is also smaller than the threshold value of the gradient magnitude average value. Then, the pixels inside the circular region are marked as inside a cardiac chamber region, otherwise, the pixels are marked as belonging to a non-cardiac chamber region. The “or” operation is performed between the cardiac chamber region which is marked out in this step and the cardiac chamber region which is marked out in the step 2, and a refined cardiac chamber region is obtained by merging.
[0093] (4) The operator repeats the step 3 according to the clinical needs; in each process, the radius of the circular region which is used currently is half of that of the circular region which was used at the last time, so that the border is further refined till satisfactory results on the 2D slice maps are obtained.
[0094] (5) A final refining processing of the border is performed on the frame of the 3D data. The 3D data are formed by accumulating the 2D slices, the cardiac chamber region on each 2D slice is obtained in a step 4, and a 3D region is simultaneously formed by accumulation. The border curved surface of the 3D region is firstly marked out separately, then the border curved surface is divided into a series of spherical regions which are mutually overlapped, with points on the border curved surface as the spherical centers, and the radius the circular region which is used at the last time in the step 4 as the spherical radius. The average value of the voxel gray level value and the average value of the voxel gray level gradient magnitude of each spherical region are calculated. The gray level average value and the gradient magnitude average value of the pixels are obtained by calculating the average values of the values.
[0095] Wherein, “n” is the number of the spherical regions. Then, the gray level average value and the gradient magnitude average value of each spherical region are checked, the pixels in the spherical region are marked as inside the cardiac chamber region, and otherwise, the pixels are marked as belonging to a non-cardiac chamber region. The “or” operation is performed between the cardiac chamber region which is marked out in this step and the cardiac chamber region which was marked out in the step 4, and a refined cardiac chamber 3D region is obtained by merging.
Embodiment 1
[0096] The invention is applied to real three-dimensional (3D) ultrasonic image data processing with respect to the heart of a patient, and in the embodiment, the invention is used for obtaining the volume of a cardiac chamber and an ejection fraction.
[0097] In Step 1, medical image data of the patient are obtained by utilizing an ultrasonic imaging device. In the embodiment, a real 3D ultrasonic probe is used to scan the region of the heart, then multiple time sequences of a 3D ultrasonic image are obtained, each time sequence contains a series of frames recording one or more complete cardiac cycles, and each frame contains 3D voxel data consisting of multiple slices. The imaging device, such as Siemens SC2000 echocardiographic instrument and Philips IE33, is used.
[0098] In Step 2, the contour of the cardiac chamber is extracted from all slice images of all the frames in the real 3D ultrasonic image time sequence. In the specific embodiment, generally, 5-8 time sequences are scanned with respect to one patient, one time sequence has 8-44 frames, one frame has 256 slice images, and the size of each image is of 256*256 pixels.
[0099] The extraction of the contour of the cardiac chamber comprises the following steps:
[0100] a) In a certain slice image of a certain frame of the real 3D ultrasonic image time sequence, the position of the cardiac chamber of interest is selected by clicking with a mouse, namely a target region is selected.
[0101] More specifically, the basis for selecting the slice image is that whether the image contain the cardiac chamber of interest and is exposed most clearly. The mouse-clicking position can be clearly determined by visual inspection, and the position is obviously inside the range of the cardiac chamber.
[0102] On the interfaces of all the slices of the certain frame of data, which displays the image time sequence, an operator utilizes the mouse to click on the slices, and the click positions are required to be inside the cardiac chamber of interest. Finally, with the top left corner of the image taken as an origin, the locations in the “x” coordinate and the “y” coordinate of the position point are recorded. In the embodiment, the width direction is taken the “x” axis, and the positive direction is rightward; the height direction is taken as the “y” axis, and the positive direction is downward; and then, the “x” coordinate and the “y” coordinate are obtained. The purpose of setting the coordinates is to describe the spatial position of each pixel or voxel, which is solely determined by coordinates (x, y) or (x, y, z). In calculation, the coordinates are mainly used for judging the adjacency relationship between the pixels or the voxels (there are 8 adjacent regions or 4 adjacent regions in the case of a 2D image, and there are 6 adjacent regions or 26 adjacent regions in the case of a 3D image), so as to determine the range for setting filling cells and marking the cardiac chamber of interest (a communicated adjacency relation is formed between perfusion regions covering the cardiac chamber of interest after being marked, and then a single cardiac chamber can be separated and achieved).
[0103] Alternatively, an automatic association processing unit can also be additionally arranged, by which all the slices of the frame of the 3D image can be subject to automatic association processing upon clicking one slice, and merely one slice needs to be clicked for each frame, while other slices can be further processed automatically.
[0104] Normally, the range of an ultrasonic image contains the region of interest and the noise (region of non-interest), rather than one kind of region as in an ideal state; and due to the limitation of actual effects, the operator is required to confirm (click) the region of interest as an initial step or “starting” step for implementing the whole process.
[0105] b) A circular region is defined, with a point positioned inside the cardiac chamber as the center of the circle and a radius of “r”, the pixel gray level distribution in the region is analyzed and a model parameter (threshold parameter t) is obtained.
[0106] More specifically, as the distribution range of the pixel gray level values in the cardiac chamber could not be reflected by the pixels at the point positioned in the cardiac chamber which is clicked with the mouse, and a more accurate estimation of the gray level value distribution can be obtained by utilizing the average value of pixel in an adjacent region around the point. Therefore, when the circular region is defined with the point positioned in the cardiac chamber as the center of the circle and the radius of 5 mm, the average value of the pixel gray level value in the circular region is calculated and set as a model parameter, namely as the threshold parameter “t”, on the basis of the voxel resolution of the 3D ultrasonic image (namely, the distances between the central points of the voxels in the x, y and z directions, with unit of mm) which has been converted into the range of the circular region with cell of pixel.
[0107] c) A slice is divided into circular regions which have the radius of “r” and are mutually overlapped, so as to enable the circular regions divided to comprehensively cover the slices. Here, each circular region can be considered as a sub-region of the image filled with pixels. Further, the distribution of the pixel values in each circular region is analyzed, and the cardiac chamber is further marked out by utilizing a threshold segmentation method according to the threshold parameter “t”, namely each circular region is respectively marked either as the cardiac chamber region or as the non-cardiac chamber region.
[0108] In the step, threshold segmentation is performed regarding all pixel points of each slice by adopting the threshold value calculated in the step b). As the pixel gray level value inside the region of cardiac chamber is lower, the pixels in the slice map with value smaller than the threshold value need to be marked as inside the cardiac chamber region. In the invention, the slice is firstly divided into a series of circular regions which are mutually overlapped as the sub-regions or pixel filling regions, in which the radius of the circles is 5 mm and the distances between the centers of the circles are also 5 mm; and the range of the circular region taking pixel as cell is obtained by conversion according to the method in the step b). Then, the gray level average value of all the pixels in the region is calculated, if the average value is smaller than the threshold parameter “t”, the pixel points in the circular region are marked as inside the cardiac chamber region, and otherwise, the pixels are marked as belonging to the non-cardiac chamber region. After processing all the circular regions, the is marked map is checked for communicated regions in an 8-adjacent-region way, and the communicated region containing the position point of the cardiac chamber marked out by the operator is taken as the segmentation result of the cardiac chamber of interest. Finally, the same processing of threshold segmentation is performed on all the slices on all the frames of one image time sequence.
[0109] In Step 3, the volume of the cardiac chamber and an EF value are calculated according to the cardiac chamber region, which is marked out.
[0110] a) Obtaining the endocardial border according to the marked cardiac chamber region.
[0111] On the marked cardiac chamber region, each pixel is judged for being an internal point or being a border point by using an adjacent region checking method. If the pixel is a border point, the pixel is marked with white, and pixel points of other kinds are marked with black, so that an irregular endocardial border is obtained.
[0112] b) Counting a total number of pixels num1 inside the endocardial border.
[0113] c) Calculation a weight value with respect to the pixels on the endocardial border according to the gray level gradient, so as to apply to the number of the pixels on the endocardial border.
[0114] The number of the pixels on the endocardial border is achieved by using the following formula:
[0000]
num
2
=
∑
i
=
1
N
l
i
l
max
-
l
min
[0115] wherein, N is the total number of the pixels on the border, l max is the maximum value of gray level gradient magnitude of the pixels on the border, l min is the minimum value of the gray level gradient magnitude of the pixels on the border, and l i is the gray level gradient magnitude of each pixel on the border.
[0116] d) Calculating the volume of the cardiac chamber on a frame of the image by using the following formula:
[0000]
V
=
(
∑
i
=
1
S
(
num
1
i
+
num
2
i
)
)
×
sx
×
sy
×
sz
[0117] wherein, S is the total number of the slices on the frame of the image, num1 i is the number of the pixels inside the endocardial border on each slice, num2 i is the number of the pixels on the endocardial border on each slice, and sx, sy and sz are distances between the central points of the voxels in x, y and z directions of the frame of the image, and the unit is mm.
[0118] e) Calculating the EF value by using the following formula:
[0000]
EF
=
V
max
-
V
min
V
max
[0119] wherein, the EF value is calculated during each cardiac cycle in an image time sequence, V max is the maximum value of the volume of the cardiac chamber of each frame of the image during the cardiac cycle, and V min is the minimum value of the volume of the cardiac chamber of each frame of the image during the cardiac cycle.
Embodiment 2
Calculation of Myocardial Volume and Mass
[0120] The step 1 and step 2 of Embodiment 4 are the same as those of Embodiment 1, so that detailed explanation thereof are omitted.
[0121] After the step 1 and the step 2 are completed, the step a), the step b) and the step c) in step 2 are repeated to mark out other cardiac chamber regions on the slice, for the step of excluding the cardiac chambers in subsequent myocardial segmentation. Said other cardiac chamber regions refer to the cardiac chambers not completely exposed and unclear, on which similar segmentation operation is performed for the purpose of marking out all the cardiac chambers to avoid affecting the myocardial segmentation. This step is an additional pretreatment step performed before the myocardial segmentation, for the purpose of excluding all the cardiac chambers.
[0122] In Step 3, the myocardial contour is extracted from all the slice images of all the frames in the real 3D ultrasonic image time sequence.
[0123] a) Selecting a plurality of myocardial positions of interest by clicking with a mouse.
[0124] On the interfaces of all the slices of a certain frame of data, which displays the image time sequence, the slice is clicked by the operator utilizes the mouse, and the clicking position is required to be inside the myocardium of interest (target myocardium) and near the edge. Finally, with the top left corner of the image taken as an origin, the locations in the “x” coordinate and the “y” coordinate of the position point are recorded. There may be a plurality of myocardial position points of interest.
[0125] b) A circular region is defined with each myocardial position point as the center of a circle and a radius of “r”, the pixel gray level distribution in the region is analyzed and a model parameter (t) is obtained.
[0126] As the distribution range of the pixel gray level values in the myocardium could not be reflected by the pixels at the myocardial position point which is clicked with the mouse, and a more accurate estimation of the gray level value distribution can be obtained by utilizing the average value of pixel in an adjacent region around the selected position point. Therefore, when the circular region is defined with the myocardial position point as the center of the circle and the radius of 1 mm, the average value of the pixel gray level value in the circular region is calculated and set as the model parameter, namely as the threshold parameter “t”, on the basis of the voxel resolution of the 3D ultrasonic image (namely, the distances between the central points of the voxels in the x, y and z directions, with unit of mm) which has been converted into the range of the circular region with cell of pixel.
[0127] c) The cardiac chamber regions are firstly excluded on the slice, then the slice is further divided into circular regions which have the radius of “r” and are mutually overlapped as cells (pixel filling cells), the distribution of pixel values in each sub-region is analyzed, and the myocardium is marked out by utilizing a threshold segmentation method according to the threshold parameter “t”.
[0128] In this step, the threshold segmentation is performed on all the pixel points of the slice according to the threshold parameter “t” which is calculated in the step b, and the pixel points in all the cardiac chamber regions, which are obtained in the step 2 and the additional step, are excluded.
[0129] As the pixel gray level value inside the region where the myocardium is located is higher, the pixels in the slice with value larger than the threshold parameter “t” need to be marked as inside the myocardial region.
[0130] In the processing, the slice is firstly divided into a series of circular regions which are mutually overlapped, and the circular regions are the pixel filling cells (cells). The radius of the circles is 1 mm, the distances between the centers of the circles are also 1 mm, and the range of the circular regions taking pixel as unit is obtained by conversion according to the method in step b. Then, the gray level average value of all the pixels in the region is calculated, if the average value is larger than the threshold parameter “t”, the pixel points in the circular region are marked as inside the myocardial region, and otherwise, the pixels are marked as belonging to the non-myocardial region. After processing all the circular regions, the marked image is checked for communicated regions in an 8-adjacent-region way, and the communicated region containing the myocardial position point which is marked out by the operator is taken as the segmentation result of the myocardium of interest. Finally, the same processing of threshold segmentation is performed on all the slices on all the frames of one image time sequence.
[0131] In Step 4, the myocardial volume and the myocardial mass are calculated according to the myocardial region, which is marked out.
[0132] a) Obtaining the borders of the each myocardium according to the each marked myocardial regions.
[0133] On the marked myocardial region, each pixel is judged for being an internal point or being a border point by using an adjacent region checking method. If the pixel is a border point, the pixel is marked with white, and pixel points of other kinds are marked with black, so that an irregular myocardial border is obtained.
[0134] b) Respectively counting the total number of pixels num1 inside the myocardial border.
[0135] c) Respectively calculating a weight value with respect to the pixels on myocardial border according to the gray level gradient, so as to apply to the number of the pixels on the myocardial border.
[0136] The number of the pixels on myocardial border is achieved by using the following formula:
[0000]
num
2
=
∑
i
=
1
N
l
i
l
max
-
l
min
[0137] wherein, N is the total number of the pixels on the myocardial border, l max is the maximum value of gray level gradient magnitude of the pixels on the myocardial border, l min is the minimum value of the gray level gradient magnitude of the pixels on the myocardial border, and l i is the gray level gradient magnitude of each pixel on the myocardial border.
[0138] d) Calculating the volume of each myocardium on a frame of the image by using the following formula:
[0000]
V
=
(
∑
i
=
1
S
(
num
1
i
+
num
2
i
)
)
×
sx
×
sy
×
sz
[0000] wherein, s is the total number of the slices on the frame of the image, num1 i is the number of the pixels inside unit myocardial border on each slice, num2 i is the number of the pixels on the respective myocardial border on each slice, and sx, sy and sz are distances between the central points of the voxels in x, y and z directions of the frame of the image, and the unit is mm.
[0139] e) Calculating the mass of respective myocardium by using the following formula:
[0000]
m=ρV
[0140] wherein: ρ is myocardial average density obtained according to clinical experiments, and V is the volume of the certain myocardium of interest on the frame of the image.
[0141] In the above formula for calculating volume, uncertainty of the border voxels during precise tracing of the border is considered, so that the voxels are multiplied by a weighted value before participating in volume accumulation rather than being directly used as a volume element to participate in volume calculation. Therefore, the results obtained could reflect a certain ambiguity of the voxels, and the actual volume of the cardiac chamber or the myocardium can be reflected more accurately.
[0142] The volume parameter in the formula for calculating the EF is obtained by using the method of the invention.
[0143] The volume parameter in the formula for calculating the myocardial mass is obtained by using the method of the invention.
[0144] More specifically, the processing of filling cells provided in the present invention can be performed both on 2D slices and 3D voxel data, and further can be widely used in processing of any high-dimensional data. The geometric shapes of the filling cells are circular in the case of 2D, and pixel intensity data in the circular regions are investigated; and the geometric shapes of the filling sub-regions in the case of 3D are spherical, and voxel intensity data in spheres are investigated. The processing in the case of 2D is preliminary processing, and the processing in the case of 3D is further refining/optimized processing.
[0145] In the present invention, the divided adjacent regions are overlapped by adopting a comprehensive coverage principle. The circular regions around each set point are one of the essential factors of the invention. Different shapes can be flexibly used; and the pixel filling region (sub-region) refers to total group of the circular sub-regions around each set point.
[0146] A threshold segmentation processing proposed in the present invention is a region-based image segmentation technology, and the basic principle is dividing pixel points of the image into a plurality of categories by setting different characteristic thresholds. The commonly used characteristics comprise: gray level or color characteristic obtained from the original image; and the characteristic obtained by conversion of original gray level or color value. Assuming an original image is set as f(x, y), the characteristic value T is achieved in the f(x, y) according to a certain criterion, the image is segmented into two parts, and the image g(x, y) after segmentation is as follows: if the pixel characteristic value of the f(x, y) is larger than T, the g(x, y) is taken as 0 (black), and otherwise, the g(x, y) is taken as 1 (white), which is commonly known as image binarization. When the pixel characteristic value of the f(x, y) is smaller than T, the g(x, y) is taken as 1, and otherwise, the g(x, y) is taken as 0.
[0147] The border processing of the invention can also be applied to processing three-dimensional data, and the operation can refer to the embodiment of two-dimensional processing above. For example, the geometrical shape of the segmentation processing region can be changed from circle to sphere, and the voxels in the sphere are investigated for marking.
[0148] The present invention can also be applied to other types of image data processing, such as CT, MRI, PET, SPECT and the like, so as to segment and identify an anatomic tissue of interest and calculate relevant physiological parameters. The anatomic tissue of interest has a certain contrast with the surrounding tissues in the image, is irregular and suitable for segmentation by applying the present invention. The present invention is suitable for not only the case of normal tissues, but also the case of tissue with pathological changes.
[0149] Those skilled in the art should understand that, various modification and changes can be made to the preferred embodiments described in the specification without departing from the spirit or the scope of the invention. Thus, the invention comprises various modifications and changes within the scope defined in the attached claims and equivalent thereof. | The invention discloses a device for determining physiological parameters based on 3D medical images. The device comprises: a border determining unit, which is used for determining a border of a target region; and a volume determining unit, which is used for determining the total number of voxels in the target region according to the border determined, and calculating volume of the target region according to a specified relation formula. The invention provides the calculating and processing method and the device with clear physical significance and simple and effective algorithm, and the method and the device are particularly suitable for processing the special situations of the various hearts with pathological changes in clinical art, and can improve the objectivity and accuracy in image data processing. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation of U.S. patent application Ser. No. 11/026,863, filed on Dec. 30, 2004, and entitled “PORTABLE WHEEL CHAIR LIFT”, and the benefit of the earlier filing date of such application is hereby claimed under 35 U.S.C. §120.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to lifting devices, and more particularly, to a portable wheelchair lift device to provide access to stages, platforms, risers and the like for individuals with disabilities.
[0004] 2. Description of the Background Art
[0005] Under the Americans With Disabilities Act of 1990 (the “ADA”), the U.S. government required that public buildings be accessible to the disabled. For persons requiring a wheelchair for mobility, abrupt changes in floor elevation have to be modified to enable access by wheelchair. For new construction, a ramp is typically provided and the pitch or grade on the ramp can be no greater than one inch of rise per foot of horizontal travel and a horizontal landing five feet in length must be provided for every thirty inches of vertical travel. However, a ramp of such length occupies a significant amount of floor space. For older buildings, or even newer building where space is limited, the requirement for a ramp may simply not be practical.
[0006] The ADA also permits a vertical lifting device instead of a fixed ramp. Typically, such lifting devices are permanently mounted and include a short ramp for entering a small car which is raised and lowered by a suitable jack mechanism. Under the ADA, such lifting devices must have side walls no less than forty-two inches high and include a grab bar on one side wall. Travel surfaces must be non-skid, and the jack mechanism must be suitably enclosed.
[0007] Some available fixed lifting devices include solid side walls, and may omit a gate on one end of the lifting device. Such lifting devices can be uncomfortable to ride if one is claustrophobic or a young child; moreover, having an open end on a lift car is not safe.
[0008] Most stages in public buildings are less than about forty-two inches above the floor or ground level. As used herein, the term “stage” refers to an elevated floor, whether or not the elevated floor is actually a stage in a theater or in an auditorium. Thus, lifting devices that can elevate a user to a stage height of 42 inches are generally acceptable, though it would clearly be an advantage to reach heights of 60 inches or more.
[0009] Mobile lifting devices for the disabled are known in the prior art, e.g. as described in U.S. Pat. No. 5,105,915 (Gary) which describes a lifting device having a car including fixed sides and short, one-piece ramps at each end. The car is raised and lowered by a pantograph jack including a hydraulic pump driven by an electric motor controlled by switches. The patent also describes several lifting devices of the prior art.
[0010] An improved mobile lifting device is disclosed within U.S. Pat. No. 6,182,798 to Brady, et al., and assigned to AGM Container Controls, Inc., the assignee of the present invention. The '798 patent discloses a lift device with gates at both ends of the lift car, transparent walls, a loading ramp, a dock plate, a stage height sensor, and numerous safety features.
[0011] Nonetheless, the mobile lifting device disclosed in the aforementioned Brady '798 patent does not solve all problems that have been experienced with mobile lifting devices. For example, even when the lift car is lowered to its lowermost position, it still does not lie close enough to the ground to allow a user of a wheelchair to wheel himself or herself directly into the lift car. The lifting mechanism is housed under the lift car, so the lift car can never be lowered fully to the ground. Instead, a foldable entry ramp must be provided to enable the user to get into the lift car. This entry ramp not only adds weight and material cost to the mobile lifting device, but also poses an inconvenience to both the user and any attendant assisting the user. In addition, the requirement for an entry ramp imposes space limitations on the lift device. For example, there must be enough space between the stage and any nearby walls, or between the stage and the seating area, to accommodate not only the length of the lift car but also the additional length of the deployed entry ramp.
[0012] The mobile lift device shown in the Brady '798 patent includes a stage sensor for enabling the lift device to sense when the lift car has reached the elevation of the stage. This stage sensor must be separately disposed on the stage. Moreover, the stage sensor may inadvertently, or maliciously, be moved out of position, resulting in the lift car stopping at the wrong height.
[0013] In addition, the mobile lift device shown in the Brady '798 patent has a fixed width, i.e., the overall width of the lift device is at least as wide as the width of the lift car. It often occurs that such mobile lift devices must be transported through doorways; if the doorway is rather wide (i.e., 48″ or greater), then transporting the lift device through the doorway is usually not a problem. However, it is often impractical or impossible to transport such known lift devices through doorways narrower than 48″, such as relatively-narrow 36″ doorways often found in buildings with single doorways like older schools. This explains why the hydraulic jack mechanism used to raise the lift car is disposed directly below the lift car; were the hydraulic jack mechanism moved out around the sides of the lift car, the overall width of the lift device would be increased even more.
[0014] The Brady '798 patent discloses a mobile lifting device equipped with retractable wheels for transport. When the lift device is to be transported, the wheels are extended from the base to raise the base off of the ground. When the lift device is in proper position for use, the wheels are retracted, allowing the base to directly engage the ground. The extension and retraction of such wheels is controlled by a crank which must be rotated to raise or lower each of the four wheels. This requires some significant physical effort, as well as significant time. Moreover, the size of such wheels is relatively small (typically 3.5 inches) to allow the wheels to fit under the base. However, such small wheels make it more difficult to transport the lifting device, particularly over soft and/or irregular floor surfaces, including carpeted floors or stadium turf.
[0015] In view of the foregoing, it is an object of the present invention to provide a portable lift device suitable for lifting wheelchair-bound users up to the height of stages, platforms, risers and the like in a safe and reliable manner, and comporting with all applicable ADA requirements.
[0016] Another object of the present invention is to provide such a lift device capable of lifting users 60 inches or more above the ground while maintaining a relatively low profile when the lift car is lowered to the ground.
[0017] Yet another object of the present invention is to provide such a lift device which requires minimal floor space, and which is capable of allowing users to enter the lift car even when the stage is positioned relatively close to a wall, seating area, or other obstacles.
[0018] Still another object of the present invention is to provide such a lift device which can be transported through relatively narrow passageways from one site to another while still providing a space within the lift car wide enough to comply with ADA regulations (a clear inner width of at least 36 inches) during actual usage.
[0019] A further object of the present invention is to provide such a lift device as a self-contained unit wherein the elevational height of the lift car can be adjusted to proper stage height by the managers/owners of the facility in a repeatable fashion, without relying upon wands, sensors or switches on the stage, while protecting against inadvertent or malicious alteration by unauthorized persons.
[0020] A still further object of the present invention is to provide such a lift which can be quickly and easily transported from one site to the next with minimal effort, while accommodating relatively large transport wheels.
[0021] Another object of the invention is to provide a lifting device in which the lift car can be safely raised and lowered by a passenger or an attendant.
[0022] These and other objects of the present invention will become more apparent to those skilled in the art as the description of the present invention proceeds.
SUMMARY OF THE INVENTION
[0023] Briefly described, and in accordance with one aspect thereof, the present invention relates to a lift device that may be used to provide access to a stage ( 174 ), platform, riser of the like for individuals with disabilities, including persons who rely upon wheelchairs or crutches to move about. The lift device includes a lift car ( 162 ) suitable for supporting a person ( 166 ) in a wheel chair ( 168 ). First and second supports ( 161 , 163 ) are disposed on opposing sides of the lift car ( 162 ) for resting upon a ground surface. A lifting mechanism, which might include a pair of hydraulic cylinders ( 50 , 52 ), an electric motor ( 56 ) and a hydraulic pump ( 58 ), is housed within the first and second supports. This lifting mechanism is coupled with the lift car ( 162 ) to selectively raise or lower the lift car. By moving the lifting mechanism out from under the lift car, the floor ( 170 / 196 ) of the lift car can be fully-lowered to the ground surface. This in turn permits a user to enter or exit the lift car without the aid of a loading ramp, thereby making maximum usage of available floor space. Ideally, such lift device is portable for use at multiple locations.
[0024] Preferably, the first and second supports ( 161 , 163 ) of the aforementioned lift device extend upwardly by less than the maximum elevational height to which the floor of the lift car can be raised, thereby maintaining a relatively low profile for such lift device. A preferred manner of achieving this result is to include a generally vertical fixed track ( 200 ) within the first support ( 161 ), of essentially the same height as the first support ( 161 ). A movable intermediate member ( 204 ) slides along the fixed track ( 200 ) and includes a lift car track. The lift car ( 162 ) includes at least one roller ( 205 ) that engages the lift car track of the intermediate member ( 204 ) for guiding the lift car to its final elevation. Preferably, the same arrangement is provided in conjunction with the second support ( 163 ) so that both sides of the lift car ( 162 ) are guided in the manner just described.
[0025] Another aspect of the present invention relates to a lift device for persons with disabilities, which lift device again includes a lift car ( 162 ) suitable for supporting a person ( 166 ) in a wheel chair ( 168 ) and including a front entry door ( 164 ) used to enter the lift car from the ground, a support base ( 180 ) for resting upon a ground surface, a lifting mechanism ( 50 , 52 ) coupled between the support base and the lift car for selectively raising and lowering the lift car relative to the support base; and a scissors-like brace ( 179 ) for selectively locking the front door ( 164 ) of the lift car to the support base when the lift car is elevated above the ground surface. The scissors-like brace ( 179 ) helps stabilize the lift car ( 162 ) relative to the support base ( 180 ), and keeps the front entry door ( 164 ) closed, when the lift car ( 162 ) is elevated a nominal amount above the ground. On the other hand, the scissors-like brace ( 179 ) unlocks when the lift car ( 162 ) is lowered to the ground surface for allowing the front entry door ( 164 ) to be opened.
[0026] Another aspect of the present invention relates to a portable lift device for persons with disabilities that can be compressed to fit through narrowed passageways. The lift device includes a lift car ( 162 ) suitable for supporting a person ( 166 ) in a wheel chair ( 168 ) when configured in a normal use mode; during such normal use mode, the floor ( 170 / 196 ) of the lift car has a deployed width that accommodates wheel chairs. However, the lift car ( 162 ) can also be configured into a compressed transport mode wherein the floor ( 170 / 196 ) of the lift car has a reduced width narrower than its deployed width. The compressed transport mode allows the lift device to be transported through narrow passages that would otherwise interfere with transport of such lift device.
[0027] The aforementioned portable lift device preferably has a lift car floor ( 170 / 196 ) that includes at least a first hinged panel ( 170 a ) that extends horizontally when the lift device is in its normal use mode, but which is rotated generally toward a vertical orientation when the width of the lift device is to be minimized. Ideally, the lift car floor includes two of such hinged panels ( 170 a / 170 b ). The floor panels are preferably supported by at least one underlying telescoping cross brace ( 196 ), but preferably, by a number of such telescoping cross braces ( 196 / 196 ). The length of the telescoping cross braces ( 196 ) can be shortened after the hinged panels ( 170 a / 170 b ) are rotated toward their vertical orientation, thereby reducing the overall width of the lift device. Each telescoping cross brace ( 196 ) preferably includes a first tubular member ( 206 b ) extending from a first side of the lift car, and a second tubular member ( 206 a ) extending from the opposing second side of the lift car. The second tubular member ( 206 a ) has a greater cross-sectional dimension than the first ( 206 b ), allowing the first tubular member ( 206 b ) to slidably extend within the second tubular member ( 206 a ). A fastener ( 207 ) releasably secures the first and second tubular members in a fixed relationship for adjusting the length of the telescoping cross brace ( 196 ).
[0028] Another aspect of the present invention relates to an easily transportable lift device to provide access to a stage ( 174 ) for individuals with disabilities, wherein a series of casters or wheels ( 182 ) are removably mounted to the bottom of the lift car ( 162 ). As before, the lift device includes a support base ( 180 ) that normally rests upon the ground surface, as well as a lifting mechanism ( 50 , 52 ) coupled between the support base and the lift car for selectively raising the lift car or lowering the lift car relative to the support base.
[0029] The casters ( 182 ) can be easily mounted to the bottom of the lift car ( 162 ) by slightly elevating the lift car to provide access to the underside of the lift car. The casters ( 182 ) are then inserted into the bottom of the lift car. Once the casters are secured to the bottom of the lift car, lowering the lift car toward its fully-lowered position causes the wheels ( 182 ) to engage the floor. Further operation of the lifting mechanism (in the “lowering” direction) actually causes the support base ( 180 ) to be raised off of the ground, causing all of the weight of the lifting device to be borne by the casters ( 182 ), thereby facilitating convenient transport of the lift device. When the lift device is transported to its new location, the lift mechanism is operated to raise the lift car ( 162 ), thereby taking the weight of the lift device off of the casters ( 182 ). With the lift car in a slightly elevated position, the casters ( 182 ) can be easily removed, thereby allowing the floor ( 170 / 196 ) of the lift car to be fully lowered back to the ground.
[0030] Another aspect of the present invention relates to a lift device to provide access to a stage ( 174 ) for individuals with disabilities wherein the maximum height adjustment mechanism ( 184 ) is self-contained within the lift car ( 162 ). As before, the lift device includes a lift car ( 162 ) for supporting a person ( 166 ) in a wheel chair ( 168 ), a support base ( 180 ) for resting upon a ground surface, and a lifting mechanism ( 50 , 52 ) coupled between the support base ( 180 ) and the lift car ( 162 ) for selectively raising the lift car or lowering the lift car relative to the support base. An adjustable control member ( 190 , 192 ) housed within a side wall ( 167 ) of the lift car, and accessible through a panel ( 186 , 188 ) of such side wall ( 167 ), can be adjusted before the lift car is raised for selecting the maximum height to which the lift car should be lifted. If, upon operating the lift device, the floor ( 170 / 196 ) of the lift car is not even with the stage ( 174 ), the adjustable control member ( 190 , 192 ) can be shifted slightly until the desired height is achieved. Once the desired height is achieved, the adjustable control member ( 190 , 192 ) is locked in place, and the lift car ( 162 ) can then be repeatably raised to the height of the stage ( 174 ).
[0031] Preferably, the adjustable control member ( 190 / 192 ) causes the lifting mechanism to be disengaged, as by cutting electrical power ( 154 ) to the hydraulic pump motor (at least in the elevating direction), as the lift car reaches the desired stage height. The adjustable control member preferably includes a lever arm having a first end pivotally mounted to one of the side walls of the lift car. The second end of the lever arm sweeps through an arc as the lever arm pivots about its first end. An arcuate track ( 192 ) is preferably provided generally proximate to the second end of the lever arm, and a releasable fastener ( 190 ) releasably secures the second end of the lever arm to a selected point on the arcuate track. An electrical switch ( 154 ), either mounted to the lever arm for selectively engaging another member, or mounted to another member for selectively engaging the lever arm, is used to sense that the lift car has reached its desired height, and prevents further operation of the lift mechanism as would cause the lift car to be further elevated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a schematic drawing of the hydraulic lifting mechanism, including an electric motor, hydraulic gear pump, supplemental hand pump, control valves, and hydraulic cylinders.
[0033] FIG. 2 is an electrical circuit schematic illustrating the switches and control circuitry for controlling the operation of the motor that powers the hydraulic lifting mechanism.
[0034] FIG. 3 shows a user entering the lift car from the ground.
[0035] FIG. 4 shows a user being lifted in the lift car.
[0036] FIG. 5 shows a user entering the lift car from the stage through the stage gate.
[0037] FIG. 6 shows one of the hydraulic cylinders used to raise the lift car.
[0038] FIG. 7 shows the lift car height adjustment control knob riding within an arcuate track on the lift car side wall.
[0039] FIG. 8 shows the transport casters being installed for transporting the lift device.
[0040] FIG. 9 is a perspective view of the lift device with several components removed for clarity, and with the lift car in a raised position, and illustrating vertical fixed tracks of the first and second supports, as well as a pair of movable intermediate members that slide along the fixed tracks, each of the intermediate members including a lift car track for being engaged by a roller of the lift car.
[0041] FIG. 10 is a top view of the lift device and illustrating a pair of outer floor panels hingedly connected to a narrower central floor panel of the lift car.
[0042] FIG. 11 is a bottom view of the lift device shown in FIG. 10 and illustrating telescoping cross braces extending across the lift car below the floor panels.
[0043] FIG. 12 is a perspective view of the lift device showing the bottom of the lift device with the hinged floor panels extending upwardly, with the lift car in its narrowed configuration, and with four casters installed on the bottom of the lift car, for transporting the lift device through a narrow passage.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] The portable wheelchair lift device of the present invention uses side supports ( 161 , 163 ) that extend only about 43 inches above the ground, but the lift device is capable of raising the floor ( 170 / 196 ) of the lift car ( 162 ) to a stage height of 60 inches. Nonetheless, because the sidewalls ( 165 , 167 ) and gates ( 164 , 172 ) of the lift car are 43 inches tall, the lift device is safe for persons using crutches or walkers, in addition to wheelchair users.
[0045] By eliminating the need for an entry ramp, the lift device of the present invention requires approximately 55% less floor space as compared with a similar lift device that includes an entry ramp. The lift device requires only 5 feet of linear space in use, plus perhaps another 4 feet of space near the entry door to allow the user room to maneuver into and out of lift car. In contrast, use of the lift replaces up to 65 feet of linear ramp, saving not only the cost of the ramp itself and the space it takes up, but also the cost of the labor for installing and removing the ramp.
[0046] By allowing the lift device to be compressed to a width narrower than 36 inches (e.g., down to 33 inches), the lift device can be transported through relatively narrow doorways, allowing it to be used in a wider variety of locations, including buildings with single doorways, such as older schools. The lift is compressed and then pushed through the door on its own wheels ( 182 ). Converting the lift device for passage through narrow doorways only requires a simple tool kit.
[0047] The lift device of the present invention is a completely self-contained compact unit, and does not require any additional components, such as stage height sensors or the like. When constructed in accordance with the preferred embodiment, the lift device can easily lift a load of 750 pounds.
[0048] The portability feature of the present invention makes it possible for public facilities to save on the cost of installing multiple fixed lifts or ramps since one lift can serve multiple locations. Moreover, the use of the present lift saves valuable floor space that would otherwise be occupied by fixed ramps. The lift device of the present invention can be used by schools, colleges and universities, convention centers, auditoriums, arenas, churches, hotels, conference centers, parks and recreational facilities, courtrooms, senior activity centers, outdoor amphitheaters, fairgrounds, stadiums, amusement parks, coliseums, virtually any public facility where temporary access to stages or platforms may be required.
[0049] The lift device of the present invention can be operated independently (i.e., without the aid of an attendant) by individuals with disabilities, as required by the American with Disabilities Act (ADA), and meets all applicable ADA requirements. The lift device allows individuals with disabilities to participate in stage or platform-related activities, such as graduation ceremonies or musical performances. A grab bar extends for the full length of the inside wall of the lift car, and slip resistant surfaces are provided on the car floor and dock plate. Multiple control stations are provided, one inside the car for passenger operation, and two other control stations at the front and back ends for attendant operation, if desired. Each control station includes a constant pressure “UP/DOWN” switch ( 138 ), and the control station inside the lift car includes a separate “PUSH TO STOP” emergency button ( 160 ). The emergency stop button inside the lift car locks when pushed, and requires manual reset before operation can resume.
[0050] The lift device of the present invention is supplied with a three prong grounded electrical cord designed to be plugged into a standard 120-volt wall outlet providing 60 Hertz, single phase, 10 amp service. Once plugged in, the lift device draws only 9 amps, and is ready for use. Of course, the power supply ( 111 ) can be configured for 220/240-volt operation for use in other countries. All operating controls operate from a reduced voltage of 12 VDC. A Ground Fault Circuit Interrupter (GFCI) is incorporated within the power supply to shut off power in case of partial or complete short circuit or current overload. The hydraulic pump ( 58 ) is directly coupled to a capacitor-start one-half horsepower motor ( 56 ). Other than this hydraulic pump motor, all control and operating circuits operate from the 12 VDC solid state linear power supply ( 111 ).
[0051] No building alterations or site preparations are required. The lift only needs 5 feet of clearance in front of a stage, plus approximately four feet of free space near the entry door to allow the user to maneuver into or out of the lift device. This feature is ideal for auditoriums or other venues with limited space between the stage and seating area.
[0052] One of the advantages of the present lift device is that it can be used while an event is in progress. The lift maintains a low profile, and its quiet operation will not interrupt a performance. The entry and exit gates ( 164 , 172 ), and much of the side walls ( 165 , 167 ), are preferably made of transparent high-impact thermoplastic, making the lift unobtrusive to audiences. The passenger ( 166 ) also has a clear view of the surroundings. The hydraulic operation of the lift device provides a smooth ride and will not draw unnecessary attention to passengers. In view of its ease of use, the lift device provides accessibility for all ages.
[0053] The lift device of the present invention can be set up in only a few minutes. The lift device can be used when needed and then simply stored away when no longer needed. The lift device, in its preferred embodiment, requires a storage space of only 48 inches×60 inches.
[0054] When the transport wheels ( 182 ) are installed on the bottom of the lift car ( 162 ), the lift device is easily moved by one person, rolling on its own wheels. Once rolled into a desired position, the wheels ( 182 ) can be quickly removed to provide a stable platform for operation. The transport wheels ( 182 ) are stored in the base frame ( 180 ) when the lift device is not being transported. The transport wheels ( 182 ) are preferably fabricated from hard rubber. The transport wheels can be installed onto, and removed from, the lift car without tools. When the wheels are installed, the lift device can be rolled easily over any hard, smooth, level surface. Alternatively, the lift can be transported by fork lift, truck, or trailer when it must be moved over relatively long distances. Moreover, the lift device of the present invention can accommodate larger wheels than other lifts, making the present lift ideal for outdoor use.
[0055] The stage adjustment device ( 184 ) can be used to quickly set the correct stage height, i.e., the maximum height to which the floor of the lift car is elevated, without the need for any tools. This adjustment device can be concealed by a locked panel ( 188 ) accessible via a key to prevent unauthorized use.
[0056] As the stage gate ( 172 ) opens, a hinged dock plate ( 176 ) automatically lowers into position, spanning the gap between the lift car ( 162 ) and the stage ( 174 ). The dock plate ( 176 ) rests on the stage ( 174 ) and provides a smooth transition between the lift car floor ( 170 / 196 ) and the stage ( 174 ). When the stage gate ( 172 ) is closed, the dock plate ( 176 ) is simultaneously retracted. The lower landing gate, or entry gate ( 164 ) to the lift car ( 162 ) is provided with an electro-mechanical interlock ( 179 ) that prevents the entry gate ( 164 ) from being opened whenever the car is more than 2 inches above the fully lowered position. In addition, electrical switches ( 152 , 150 ) are provided at both the entry gate ( 164 ) and stage gate ( 172 ) to prevent any movement of the lift car ( 162 ) if either gate is open. In addition, a safety skirt ( 181 ) completely encloses and protects the area under the lift car ( 162 ). For safety reasons, both the lower entry gate ( 164 ) and the upper stage gate ( 172 ) are self-closing.
[0057] In the event of a power failure, the electrical motor ( 56 ) that powers the hydraulic pump ( 58 ) will not operate. For this reason, a hydraulic hand pump ( 80 ) is provided in ar emergency to raise and lower the lift car ( 162 ) without electrical power.
[0058] The lift device constructed in accordance with the present invention weighs approximately 975 pounds maximum, provides vertical lift/lowering speeds of seven ( 7 ) feet per minute, and is capable of elevating the lift car to an elevational height within the range of 12 inches to 60 inches in infinitely adjustable increments. The lift car floor area ( 170 ) is preferably 36″×48″, and as noted earlier, the gates ( 164 , 172 ) and side panels ( 165 , 167 ) of the lift car are 43 inches tall. Before being compressed to narrow passage mode, the lift device has an overall width of approximately 48 inches. The lift car ( 162 ), base support frame ( 180 ), and the hydraulic lifting cylinders ( 50 , 52 ) are all preferably formed from ASTM A36, AISI 1018, or AISI 1020 Steel. All transparent windows are preferably fabricated from ¼″ thick high impact strength clear thermoplastic.
[0059] Those skilled in the art will now appreciate that a simple and inexpensive portable wheel chair lift apparatus has been described. While the present invention has been described with respect to preferred embodiments thereof, such description is for illustrative purposes only, and is not to be construed as limiting the scope of the invention. Various modifications and changes may be made to the described embodiments by those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims. | A portable wheel chair lift device includes a lift car, a support base, and a lifting mechanism coupled thereto to selectively raise or lower the lift car while allowing the floor of the lift car to be fully-lowered to the ground surface. The lift car floor can be folded and collapsed to a reduced width allowing transport through narrow passages. Transport casters are removably mounted to the bottom of the lift car to facilitate transport. The lift device includes a height adjustment control within the lift car to repeatably raise the lift car to the height of a stage. | 8 |
ORIGIN OF THE INVENTION
The invention described herein was made in the performance of work under a NASA contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 U.S.C. 2457).
This application is a continuation-in-part of our copending application Ser. No. 288,267, filed July 30, 1981, now U.S. Pat. No. 4,395,557 which in turn is a continuation-in-part of application Ser. No. 175,452, filed Aug. 5, 1980, now U.S. Pat. No. 4,276,344 issued June 30, 1981.
TECHNICAL FIELD
This invention relates to addition polyimide resins and to fiber or fabric-reinforced composites made from them.
BACKGROUND
Strong light-weight composites can be made by embedding various types of fibers or fabrics in a resin matrix. The polymer used for such a matrix is generally an epoxy resin, although several other resins such as phenolic, novolac, poly(ether-sulfone), poly(phenyl-sulfone), and bismaleimide resins have also been used for certain applications. As fibers or fabrics, carbon and graphite products have been quite useful in the composite structures.
The search for flame resistant materials to form laminates that can be used with greater safety in places such as aircraft cabins, has led to the selection of high temperature resins such as bismaleimides which have high anaerobic char yield (Scientific & Technological Aerospace Reprints, (1976), 14-16, Abstract N76-25354), and to the inclusion of phosphorus-containing compounds either in a mixture with or as an integral part of the resin used as matrix. Searle, in U.S. Pat. No. 2,444,536, discloses a widely used method for the preparation of maleimide polymers. As to the use of phosphorus-containing compounds, Kourtides et al. (Proceedings of the Adhesives for Industry Conference, El Segundo, CA, June 24-25, 1980) have shown substantial improvement in various properties of certain epoxy resins by preparing them with a bis(3-aminophenyl)methylphosphine oxide or its bisphenol analog, instead of the conventional diamine or phenol monomers or curing agents of the art. In summary, however, it can be stated that while the introduction of phosphorus into organic polymers has generally resulted in reduced flammability, increased adhesion, and better solubility in polar solvents, none of the resins used in the composite art are nonflammable.
In copending application Ser. No. 175,452, filed Aug. 5, 1980, entitled "Phosphorus-Containing Bisimide Resins", now U.S. Pat. No. 4,276,344 issued June 30, 1981, bisimides are prepared from phosphine oxides by a reaction typified by the following: ##STR1## The monomers (bisimides) 3 can be used to impregnate fibers and cloth and, upon curing to rigid composites, confer fire resistant qualities to the fiber or fabric reinforcement present in the composites.
It is an object of the present invention to provide improvements upon such monomers, polymers and impregnated fibers and fabrics.
DISCLOSURE OF THE INVENTION
We have found that the trisamino precursor typified by the following: ##STR2## can be used in place of the bisamino precursor. This results in curing at a lower temperature, e.g., 180° C., with good fire resistance. A further advantage is the greater ease of preparing the trisamino precursors.
We have found an improved method for reducing the nitro precursors of these trisamino compounds, wherein the nitro groups are reduced using hydrazine hydrate as the reducing agent and palladium/charcoal or Raney nickel as a catalyst.
DETAILED DESCRIPTION OF THE INVENTION
Using the triamine 4 and the anhydride 2 as models, and in a variant using also a coupling agent (a dianhydride), the following monomers result. ##STR3## In the equations above, R 1 and R 2 may be H, methyl, chlorine, or such other atoms or groups as are compatible with the respective reactions and with polymerization of the monomers.
X is a linking entity which may be a valence bond, a bivalent atom (e.g., >O or >S or a bivalent group, [e.g., --C n H 2n -- (n=1, 2, 3, etc.)], >C═O, >C═S, >C(CF 3 ) 2 , >SO 2 or any other bivalent group which is compatible with reaction (4) and with polymerization of the monomers. R 3 is --NH 2 or the imide group; ##STR4##
Further, the benzene rings may be substituted by functional and/or non-functional groups provided they do not interfere with the reactions involved in forming the monomers and provided they do not interfere with polymerization and with the thermal stability of the polymers. Examples of substituents are alkyl, e.g., C 1 to C 5 straight and branched chain alkyl; chlorine; aryl, e.g., phenyl and tolyl. Condensed ring phosphine oxides may be used.
Polymerization is accomplished thermally or by means of a catalyst such as cobalt or other metal naphthenates together with peroxides. Partial polymerization may be carried out with the monomer; fibers or fabric may then be impregnated with the resulting oligomer or lower polymer; and the impregnated material may then be cured at a higher temperature. The trisimides polymerize by opening of the olefinic double bonds. With the bisimides, which also contain free primary amine groups, nucleophilic addition of the free amino group to the double bond may also occur.
The linking groups illustrated in 10 above result in polymers having diminished cross linking density, hence composites made with these polymers have greater toughness.
The phosphine oxide component of the imides of this invention can be made from the triphenylphosphine oxide by nitration, followed by reduction of the nitro group to the amino group by, for example, stannous chloride dihydrate and concentrated hydrochloric acid, by hydrazine hydrate and palladized charcoal, or by hydrogen under pressure in the presence of a platinum catalyst. ##STR5## Imides can be prepared by reacting stoichiometric quantities of the reactants in a polar solvent (e.g., dimethylformamide, dimethylacetamide, N-methyl pyrrolidine, etc.) and cyclodehydrating the intermediate amic acid by sodium acetate and acetic anhydride. Alternatively refluxing the reactants in glacial acetic acid or dimethylformamide can also be used to prepare imides. The resulting imides can be cured in the temperature range of 180°-300° C.
The resins produced according to the process just described are suitable for many applications in which good adhesion and excellent resistance to heat, fire, solvents and chemicals are required. In the aerospace industry, the new resins may be used as adhesives and as matrix materials for fiber-reinforced lightweight composites. The fibers employed in such composites may be selected from the reinforcing fibers known in the art. For example, they may be inorganic fibers such as metal fibers; or ceramic fibers such as alumina fibers, silicon carbide fibers, boron nitride fibers, glass fibers or carbon fibers. They may also be organic fibers such as the aramid fibers (for example the aramids marketed under the names Kevlar®, Nomex®, Kevlar®-49, "X-500", and the like). These fibers can be in organized form such as fabrics, yarns, tapes, or the like or can be in disorganized forms such as felts, loose fibers, chopped fibers or the like as is known in the art. The exact form of the reinforcing fibers will in part depend upon the method employed to form the finished composite body which can be selected from the methods known in the art for forming bodies from fiber-reinforced resin including laminating, filament-winding, molding, pultruding, spray-molding, adhesive bonding, mandrel wrapping, vacuum bag forming, and the like. In such applications, conventional resin to reinforcement ratios--e.g. 5:1 to 1:5 by weight are employed so long as adequate resin is present to give a continuous resin phase in the composite. To produce such composites, the imide resin is either dry-mixed as a powder with the reinforcement and then melt-cured or dissolved in an appropriate solvent and applied to the reinforcing fibers as a "varnish" and cured. A suitable solvent for the second mode of application is an organic solvent such as a ketone, for example acetone, methyl ethyl ketone or methyl isobutyl ketone or the like or an aprotic organic liquid such as methylene chloride, dimethylformamide (DMF), dimethylsulfoxide (DMSO), or dimethylacetamide (DMAC). Preferred solvents are the aprotic solvents, especially DMF, DMSO and DMAC. When using the "varnish" method, the solution is applied to the reinforcing fibers, generally in an amount sufficient to at least impregnate the fiber. This prepreg material is formed into the shape desired for the finished article. This may be done by molding, laminating, pressing, winding, laying up or the like technique appropriate for the particular form of reinforcement employed.
The solvent is removed from the resin solution either before or after the resin/reinforcement material is formed into the desired shape. This can be accomplished by evaporation effected by heat, vacuum or a combination thereof. If heat is employed, it is generally desirable to employ a temperature below the temperature to be used to cure the resin, i.e. a temperature of from about 50° C. to about 150° C., preferably about 75° C. to about 145° C. and more preferably about 100° C. to 140° C. In a typical preparation, the solvent is removed by evaporation in an air oven at 125°-135° C. and layers of the impregnated fiber materials are formed by means of pressure and high temperature into the desired molded laminate. The laminate is then cured at an elevated temperature, for example 150°-300° C., preferably 160°-270° C. and especially 180°-250° C. The cure can be done in stages, as is known in the art.
The imide resins according to the present invention have noteworthy advantages over the imide resins of the aforesaid now-issued application. The curing of these resins can be done at relatively low temperatures while retaining the outstanding flame resistant properties of the laminates. Furthermore, the tris(aminophenyl)phosphine oxide is more easily obtained than the bis(aminophenyl)-methylphosphine oxide.
The following examples serve to illustrate the present invention.
EXAMPLE 1
Tris(m-aminophenyl) phosphine oxide, 24.25 g, was placed in a flask with 110 ml dimethyl formamide (DMF). Maleic anhydride was added (7.35 g) in two portions over a period of ten minutes. The solution was stirred at 50° C. for one hour. Benzophenone tetracarboxylic dianhydride (BTDA) (12.15 g) was then introduced and stirring was continued overnight. The solution was then heated at 145° C.±2° C. for one hour and then refluxed for 30 minutes. The polymerization product obtained in this manner can further be processed as follows:
The graphite fabric (8 harness satin-weave designated as style 133 fabric) is coated with this resin solution. The impregnated fabric is then dried in a circulating air oven at 125°-135° C. for 20 minutes. Several pre-impregnated graphite fabric pieces are placed one upon the other (4-9 plies) into a platen press and the laminate is hardened under a pressure of 125 psi and a temperature of 180° C. for 150 minutes. Post-curing of the hardened laminate was done at 220° C. for 16 hours. Physical properties of such laminates were tested by an Instron Tensile Tester. A laminate having 21-22% resin was found to have a short beam shear strength of 3300 psi and a flexural strength of 96,040 psi. The laminate did not burn in pure oxygen. The glass transition temperature of a 4-ply laminate was found to be 385° C. No delamination was observed by boiling these laminates in water for 20 hours.
Alternatively, the imide monomer can be isolated from the DMF solution by precipitating it with water and washing with boiling methanol and acetone. Curing of this resin was done thermally at 180° C., 225° C., and 232° C. and an anaerobic char yield of cured resin was found to be 68-70%. Elemental analysis gave the following results: C=65.16%, H=3.54%, N=7.12%, P=4.40%. The values calculated for formula C 61 H 38 P 2 O 11 N 6 are C=67.03%, H=3.47%, N=7.69%, P=5.67%.
EXAMPLE 2
Tris(m-aminophenyl) phosphine oxide 4.27 g, was dissolved in 25 ml DMF and 2.69 g of maleic anhydride added. The solution was stirred at 50° C. for one hour. BTDA (2.09 g) was then introduced and solution stirred overnight. The solution was heated at 145° C.±2° C. for 45 minutes and refluxed for 10 minutes.
A graphite cloth laminate was cured in a manner similar to that described in Example 1. This material had a glass transition temperature of 314° C. as obtained by DMA.
Trisimide monomer could be isolated by precipitation from the DMF solution with water. An anaerobic char yield of 62-69% was obtained. Elemental analysis showed the following results: C=64.40%, H=3.6%, N=6.92%, P=5.14%. The values calculated for formula C 69 H 38 P 2 O 15 N 6 are C=66.13%, H=3.03%, N=6.71%, P=4.95%.
EXAMPLE 3
Tris(aminophenylphosphine oxide) 1.615 g and dichloromaleic anhydride 2.48 g were dissolved separately in glacial acetic acid and mixed. This solution was then refluxed gently for 21/2 hours. The trisimide was isolated by precipitation in water. The yellow precipitate was dissolved in and recrystallized from chloroform and petroleum ether. The anaerobic char yield of the polymer formed from this monomer by curing at 305° C. for 30 minutes was found to be 65%.
EXAMPLE 4
Tris(aminophenyl)phosphine oxide 1.61 g and citraconic anhydride 1.12 g were separately dissolved in glacial acetic acid. The two solutions were mixed and gently refluxed for 21/2 hours. The imide was isolated by precipitation in water. The precipitates were dissolved in acetone and solution was concentrated. The imide was recovered by addition of petroleum ether. Elemental analysis gave the following results: C=65.33%, H=4.45%, N=7.31% and P=5.42%. Calculated values for the formula C 28 H 22 PO 5 N 3 C=65.75%, H=4.30%, N=8.21% and P=6.06%. Anaerobic char yield of resin cured at 232° C. for 2 hours was 62.5%.
EXAMPLE 5
Tris(aminophenyl)phosphine oxide 1.61 g was dissolved in 10 ml DMF and 1.62 g of maleic anhydride added. The solution was stirred overnight and then heated at 135°-145° C. for 50 minutes and refluxed for another 10 minutes. The trismaleimide was isolated by precipitation in water and recrystallized from acetone and petroleum ether. The anaerobic char yield of the imide resin formed by curing at 232° C. for 2 hours was found to be 64.5%.
EXAMPLE 6
Alternatively, the trismaleimide was prepared by dissolving 1.62 g of maleic anhydride and 1.61 g of the triamine 4 separately in 25 ml of glacial acetic acid. The solutions were then mixed and refluxed for 12-15 hours. Imide monomer was isolated by precipitation in water and filtration. The residue was washed several times with sodium bicarbonate solution until free from acid. After drying, the purification was done with chloroform and petroleum ether.
Trismaleimide was also prepared by dissolving 1.61 g of triamine 4 in 10 ml dimethylformamide and adding 1.62 g of maleic anhydride. The solution was stirred at room temperature for 1 hour and then 0.5 g of fused sodium acetate was added followed by 3.5 ml of acetic anhydride. The solution was stirred as mentioned above.
EXAMPLE 7
Triscitraconimide was also prepared by carrying out cyclodehydration with fused sodium acetate and acetic anhydride as in Example 6. Alternatively the condensation reaction of triamine and citraconic anhydride was done in glacial acetic acid by reacting 1.61 g of amine with 1.85 g of citraconic anhydride and refluxing the solution for 12-15 hours. Triscitraconimide was isolated by precipitation in water and filtration. Further processing was similar to Example 6.
As stated above, we have also discovered an improved method of reducing tris(nitrophenyl)phosphine oxides to the triamino compounds. This improved method employs hydrazine hydrate as the reducing agent and a palladium/charcoal or Raney nickel catalyst. These systems have been used heretofore to reduce nitro groups in mono- and dinitroaromatic compounds: see Furst, Chem Rev, 65:51 (1965) and Fieser and Fieser, "Reagents for Organic Syntheses" p. 440 (1967), John Wiley. However, as far as we know, such systems have not been employed to reduce nitrophenylphosphine oxides. The system may be used to reduce nitro groups in dinitro compounds such as 1 above or trinitro compounds such as 4 above. The following examples will illustrate this aspect of our invention.
EXAMPLE 8
41.3 g of the trinitro oxide 11 (0.1 mol) (m.p. 244°-245° C.) and 420 ml of 95% ethanol were placed in a 1 l three-necked flask equipped with a reflux condenser, thermometer and dropping funnel. 1.70 g of 10% palladium on carbon was added and the mixture warmed to 35°-40° C. Stirring was done with a magnetic stirrer. About 38 ml of hydrazine hydrate (0.75 mole) (Baker Chem. Co., 99%) was added from the dropping funnel over a 40 minute period. The reaction is exothermic and addition of hydrazine has to be done dropwise. 0.3 g more of Pd/C was then added and mixture refluxed for 1 h. The hot solution was then filtered with gentle suction through a thin layer of Celite. The flask was rinsed with hot ethanol and the catalyst and Celite were washed with it. The combined filtrates on cooling gave white crystals of triamine which were collected by filtration and suction dried. The precipitates after washing with water were dried in a vacuum oven at 80° C., yield=28-29 g (88-89%, m.p. 258°-263° C.). The filtrate was concentrated under reduced pressure and when the volume was reduced to about 30 ml it was added to water. A second crop of white precipitate of amine was obtained (1-1.5 g).
For easier control the hydrazine hydrate can be diluted with alcohol before addition. The Pd/C can be reused.
Elemental analysis of the amine gave the following results:
C=66.7%, H=5.67%, N=12.95%, P=9.98%
Calculated values for C 18 H 18 N 3 PO: C=66.81%, H=5.61%, N=13.0%, and P=9.6%.
EXAMPLE 9
Bis-(m-aminophenyl)methyl phosphine oxide was also prepared in a similar way by reduction of the dinitro compound. The alcoholic filtrate was concentrated under reduced pressure to a small volume and then amine was precipitated by adding an equal volume of toluene: petroleum ether. (yield=80%, m.p. 145°-149° C.).
In the mass spectra of these amines M-1 ion was the base peak. Eight most intense peaks, i.e., fragment ion values are listed in order to decreasing relative abundances (base peak is given first). Tris(m-aminophenyl)phosphine oxide: 322, 323, 93, 65, 229, 182, 230.
Bis(m-aminophenyl) methylphosphine oxide: 245, 246, 65, 92, 93, 231, 214, 63. The infra-red spectra of the amines showed characteristic absorption due to amino and P=O groups.
The trinitro compound 11 of Example 8 and the dinitro compound of Example 9 were, respectively, the m-nitro compounds.
EXAMPLE 10
The production of a fiber-reinforced composite as shown in Example 1 is repeated eight times with changes. The resin and cure cycle of Example 1 is used. The reinforcement and finished form is varied as shown in Table 1.
TABLE 1______________________________________RepeatNumber Reinforcement Product Form______________________________________A Fiberglass Cloth Hard-laid housingB Kevlar ® Aramid Cloth LaminateC Kevlar ® Aramid Fiber Yarn Filament-wound cylinderD Boron Filament Cloth LaminateE Chopped Fiber Glass Cured molded partsF Aramid Felt LaminateG Silicon Carbide Chopped Fiber Molded parts______________________________________ | Flame-resistant reinforced bodies are disclosed which are composed of reinforcing fibers, filaments or fabrics in a cured body of bis- and tris-imide resins derived from tris(m-aminophenyl) phosphine oxides by reaction with maleic anhydride or its derivatives, or of addition polymers of such imides, including a variant in which a mono-imide is condensed with a dianhydride and the product is treated with a further quantity of maleic anhydride. | 8 |
FIELD OF THE INVENTION
The present invention relates generally to power converters, and more particularly to alternating current (AC) to direct current (DC) converters with power factor corrective (PFC) requirements.
BACKGROUND OF THE INVENTION
AC to DC power converters with PFC capability are desirable in a number of applications including, for example, in laptop and desktop computers. However, conventional AC to DC power converters have high harmonic input currents and their efficiency is not as good as desired for many applications. In this regard, FIG. 1 is a schematic diagram of one prior art AC to DC converter with PFC front end 110 . As shown, the PFC front end 110 includes a valley filling circuit 140 (inductor 142 , diode 144 and transistor 146 ) and a current steering network 160 having two capacitors 162 , 166 and three diodes 170 , 176 , 178 arranged in a network with four nodes. FIG. 2 is a plot of a simulated input current waveform 202 for the PFC front end 110 shown in FIG. 1 . As shown in the plot of FIG. 2 , the input current waveform includes significant harmonics.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is providing an AC to DC converter with a PFC front end.
Another object of the present invention is reducing input current harmonics in an AC to DC converter with a PFC front end.
These objects and others are achieved by various aspects of the high efficient input current shaping AC to DC converter with PFC front end of the present invention. According to one aspect, an AC to DC converter connectable with an alternating current source and operable to output a direct current comprises a PFC front end followed by a DC/DC converter. The PFC front end includes current steering circuitry that reduces harmonic components present in an input current waveform received by the PFC front end from the alternating current source. The DC/DC converter comprises one that presents pure resistive input impedance to the PFC front end. The DC/DC converter outputs the direct current to a load. By connecting the objects in the aforementioned ways, the PFC front end does not have a power switch which is operating all the time or even a power switch which is only operating for a short time period around the input current zero crossing. As a consequence, the switching loss is greatly reduced while at the same time keeping a high power factor and low harmonics.
The current steering circuitry may be configured in various manners. In one embodiment, the current steering circuitry comprises three capacitors and six diodes (3C&6D). The three capacitors and six diodes may, for example, be arranged in a network having six nodes. For example, a first capacitor may be connected between a first node and a second node, a second capacitor may be connected between a third and a fourth node, a third capacitor may be connected between a fifth node and a sixth node, a first diode may be connected between the first node and the fifth node, a second diode may be connected between the first node and the third node, a third diode may be connected between the second node and the third node, a fourth diode may be connected between the fourth node and the fifth node, a fifth diode may be connected between the fourth node and the sixth node, and a sixth diode may be connected between the second node and the sixth node. In another embodiment, the current steering circuitry comprises two capacitors and three diodes (2C&3D). The two capacitors and three diodes may, for example, be arranged in a network having four nodes. For example, a first capacitor may be connected between a first node and a second node, a second capacitor may be connected between a third and a fourth node, a first diode may be connected between the first node and the third node, a second diode may be connected between the second node and the third node, and a third diode may be connected between the second node and the fourth node.
In addition to current steering circuitry, the PFC front end of the converter may also include valley filling circuitry that reduces the presence of discontinuities in the input current waveform. In one embodiment, the valley filling circuitry comprises an inductor, a diode, and a switching element. The diode, inductor, and switching element may, for example, be arranged in a network having four nodes. For example, the inductor may be connected between a first node and a second node, the diode may be connected between the second node and a third node, and the switching element may be connected between the second node and a fourth node.
The PFC front end may include other components in addition to the aforementioned current steering circuitry and valley filling circuitry. Further, the PFC front end may be implemented with different embodiments of the current steering circuitry in combination with valley filling circuitry or without valley filling circuitry. For example, the PFC front end may be configured with a 3C&6D current steering network and valley filling circuitry or with a 3C&6D current steering network but no valley filling circuitry. By way of further example, the PFC front end may be configured with a 2C&3D current steering network and valley filling circuitry or with a 2C&3D current steering network and no valley filling circuitry.
According to another aspect, AC to DC conversion means connectable with an alternating current source and operable to output a direct current comprise first stage means for correcting a power factor and second stage means for outputting the direct current to a load connected to the second stage means. The first stage means include current steering means for reducing harmonic components present in an input current waveform received by the first stage means from the alternating current source. The second stage means present pure resistive input impedance to the first stage means. The current steering means may, for example, be current steering circuitry such as, for example, a 3C&6D current steering circuit or a 2C&3D current steering circuit. The first stage means may optionally include valley filling means for reducing the presence of discontinuities in the input current waveform around the zero crossing such as, for example, a valley filling circuit. The second stage means may, for example, be a constant power DC/DC converter.
According to one more aspect, a current shaping AC to DC converter comprises a valley filling circuit, a current steering circuit connected with the valley filling circuit, and a constant power DC/DC converter connected with the current steering circuit and the valley filling circuit. In one embodiment, the current steering circuit comprises three capacitors and six diodes arranged in a network having six nodes with a first capacitor connected between a first node and a second node, a second capacitor connected between a third and a fourth node, a third capacitor connected between a fifth node and a sixth node, a first diode connected between the first node and the fifth node, a second diode connected between the first node and the third node, a third diode connected between the second node and the third node, a fourth diode connected between the fourth node and the fifth node, a fifth diode connected between the fourth node and the sixth node, and a sixth diode connected between the second node and the sixth node. In another embodiment, the current steering circuit comprises two capacitors and three diodes arranged in a network having four nodes with a first capacitor connected between a first node and a second node, a second capacitor connected between a third and a fourth node, a first diode connected between the first node and the third node, a second diode connected between the second node and the third node, and a third diode connected between the second node and the fourth node. In one embodiment, the valley filling circuit comprises an inductor, a diode, and a switching element arranged in a network having four nodes with the inductor connected between a first node and a second node, the diode connected between the second node and a third node, and the switching element connected between the second node and a fourth node.
Various nodes of the current steering network and the valley filling circuit may coincide thereby connecting the valley filling circuit with the current steering circuit. For example, the first and sixth nodes of the 3C&6D current steering network may coincide with the third and fourth nodes, respectively, of the valley filling circuit. In a further example, the first and fourth nodes of the 2C&3D current steering network may coincide with the third and fourth nodes, respectively, of the valley filling circuit. Additionally, input terminals of the DC/DC converter may be connected to various nodes of the current steering network and valley filling circuit. For example, one input terminal of the DC/DC converter may be connected with the coincident first/third nodes of the 3C&6D current steering network/valley filing circuit and the other input terminal of the DC/DC converter may be connected with the coincident sixth/fourth nodes of the 3C&6D current steering network/valley filling circuit. In a further example, one input terminal of the DC/DC converter may be connected with the coincident first/third nodes of the 2C&3D current steering network/valley filing circuit and the other input terminal of the DC/DC converter may be connected with the coincident fourth/fourth nodes of the 2C&3D current steering network/valley filling circuit.
These and other aspects and advantages of the present invention will be apparent upon review of the following Detailed Description when taken in conjunction with the accompanying figures.
DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and further advantages thereof, reference is now made to the following Detailed Description, taken in conjunction with the drawings, in which:
FIG. 1 is a schematic diagram showing a prior art AC to DC converter with a prior art PFC front end;
FIG. 2 is a plot of a simulated input current waveform for the AC to DC converter PFC front end shown in FIG. 1 ;
FIG. 3 is a schematic diagram of one embodiment of an AC to DC converter having a PFC front end combining 3C&6D current steering circuitry with valley filling circuitry, followed by a dc/dc converter with pure resistive input impedance;
FIG. 4 is a plot showing a simulated input voltage waveform and corresponding input current waveform for the AC to DC converter of FIG. 3 ;
FIG. 5 is a schematic diagram of one embodiment of an AC to DC converter having a PFC front end with 3C&6D current steering circuitry and without valley filling circuitry, followed by a dc/dc converter with pure resistive input impedance;
FIG. 6 is a plot showing a simulated input voltage waveform and corresponding input current waveform for the AC to DC converter of FIG. 5 ;
FIG. 7 is a schematic diagram of one embodiment of an AC to DC converter having a PFC front end combining 2C&3D current steering circuitry with valley filling circuitry, followed by a dc/dc converter with pure resistive input impedance;
FIG. 8 is a plot showing a simulated input voltage waveform and corresponding input current waveform for the AC to DC converter of FIG. 7 ;
FIG. 9 is a schematic diagram of one embodiment of an AC to DC converter having a PFC front end with 2C&3D current steering circuitry and without valley filling circuitry, followed by a dc/dc converter with pure resistive input impedance; and
FIG. 10 is a plot showing a simulated input voltage waveform and corresponding input current waveform for the AC to DC converter of FIG. 9 .
DETAILED DESCRIPTION
FIG. 3 shows a schematic diagram of one embodiment of a power converter 300 . The power converter 300 includes a valley fill circuit 340 , a current steering network 360 , and a DC/DC converter 390 . The valley fill circuit 340 , the current steering network 360 , and the DC/DC converter 390 are connected to one another at node 302 . The valley fill circuit 340 , the current steering network 360 and the DC/DC converter 390 are also connected to common node 304 . Common node 304 may be referred to herein as the ground reference or simply ground. The power converter 300 is connectable to an alternating current source 306 (e.g., an electrical outlet) and operates to convert an input alternating current to direct current that may be supplied to a load 308 . Together, the valley filling circuit 340 and the current steering circuit 360 comprise a PFC front end 310 . In other embodiments, such as described herein in connection with FIGS. 5 and 9 , valley filling circuitry is not included in the PFC front end 310 .
In addition to the valley fill circuit 340 and the current steering network 360 , the PFC front end 310 of power converter 300 may also include various additional components such as diodes (D 1 , D 2 , D 3 , D 5 , D 7 ) 312 - 320 , resistors (R 7 , R 13 ) 322 , 324 , and capacitor (C 2 ) 326 . Diode (D 1 ) 312 is connected to diode (D 3 ) 316 , diode (D 7 ) 320 , resistor (R 13 ) 324 and capacitor (C 2 ) 326 at node 330 and to source 306 through EMI 328 and diode (D 2 ) 314 at node 332 . Diode (D 2 ) 314 is connected to diode (D 1 ) 312 and source 306 through EMI 328 at node 332 and to common node 304 . Diode (D 3 ) 316 is connected to diode (D 1 ) 312 , diode (D 7 ) 320 , resistor (R 13 ) 324 and capacitor (C 2 ) 326 at node 330 and to diode (D 5 ) 318 and source 306 through EMI 328 at node 334 . Diode (D 5 ) 318 is connected to diode (D 3 ) 316 and source 306 through EMI 328 at node 334 and to common node 304 . Diode (D 7 ) 320 is connected to diode (D 1 ) 312 , diode (D 3 ) 316 , resistor (R 13 ) 324 and capacitor (C 2 ) 326 at node 330 and to valley fill circuit 340 , current steering network 360 and DC/DC converter 390 at node 302 . Resistor (R 7 ) 322 is connected between capacitor (C 2 ) 326 and common node 304 . Resistor (R 13 ) 324 is connected between node 330 and valley fill circuit 340 . Capacitor (C 2 ) 326 is connected between node 330 and resistor (R 7 ) 322 . The various components included in the power converter 300 in addition to the valley fill circuit 340 , current steering network 360 and DC/DC converter 390 and the arrangement thereof are exemplary, and in other embodiments, it may be possible to employ different components arranged in similar or in different configurations.
The valley fill circuit 340 includes an inductor (L 1 ) 342 , a diode (D 6 ) 344 , and a switching element (S 3 ) 346 arranged in a network having four nodes 302 , 304 , 336 and 350 . Inductor (L 1 ) 342 , diode (D 6 ) 344 and switching element (S 3 ) 346 are connected to one another at node 350 . More particularly, inductor (L 1 ) 342 is connected between node 336 (a terminal of resistor (R 13 ) 324 ) and node 350 , diode (D 6 ) 344 is connected between node 350 and node 302 , and switching element (S 3 ) 346 is connected between node 350 and common node 304 . When closed, switching element (S 3 ) 346 provides a zero-resistance path from node 350 to common node 304 . In this regard, switching element (S 3 ) may comprise various components including, for example, one or more transistors (e.g., MOSFET(s) and/or BJT(s) and/or IGBT(s)).
The current steering network 360 includes three capacitors (C 9 , C 10 , and C 11 ) 362 - 366 and six diodes (D 8 , D 9 , D 10 , D 11 , D 12 , D 13 ) 368 - 378 arranged in a network having six nodes 302 , 304 , 380 - 386 . Capacitor (C 9 ) 362 is connected to diode (D 8 ) 368 and diode (D 9 ) 370 at node 302 and to diode (D 12 ) 376 and diode (D 13 ) 378 at node 380 . Capacitor (C 10 ) 364 is connected to diode (D 9 ) 368 and diode (D 11 ) 374 at node 382 and to diode (D 10 ) 372 and diode (D 13 ) 378 at common node 304 . Capacitor (C 11 ) 366 is connected to diode (D 9 ) 370 and diode (D 12 ) 376 at node 384 and to diode (D 10 ) 372 and diode (D 11 ) 374 at node 386 . Diode (D 8 ) 368 is connected to diode (D 9 ) 370 and capacitor (C 9 ) 362 at node 302 and to diode (D 11 ) 374 and capacitor (C 10 ) 364 at node 382 . Diode (D 9 ) 370 is connected to diode (D 8 ) 368 and capacitor (C 9 ) 362 at node 302 and to diode (D 12 ) 376 and capacitor (C 11 ) 366 at node 384 . Diode (D 10 ) 372 is connected to diode (D 11 ) 374 and capacitor (C 11 ) 366 at node 386 and to capacitor (C 10 ) 364 and diode (D 13 ) 378 at common node 304 . Diode (D 11 ) 374 is connected to diode (D 10 ) 372 and capacitor (C 11 ) 366 at node 386 and to diode (D 8 ) 368 and capacitor (C 10 ) 364 at node 382 . Diode (D 12 ) 376 is connected to diode (D 13 ) 378 and capacitor (C 9 ) 362 at node 380 and to diode (D 9 ) 370 and capacitor (C 11 ) 366 at node 384 . Diode (D 13 ) is connected to diode (D 12 ) 376 and capacitor (C 9 ) 362 at node 380 and to capacitor (C 10 ) 364 and diode (D 10 ) 372 at common node 304 .
The DC/DC converter 390 may be configured in a number of different manners. In this regard, DC/DC converter 390 may, for example, be configured to step-up or step-down the output voltage that is output to load 308 . Regardless of its configuration, it is desirable that DC/DC converter 390 be of a constant power type. Stated another way, DC/DC converter 390 desirably presents pure resistive input impedance to the PFC front end 310 . A constant power/pure resistive input impedance DC/DC converter 390 is desirable to avoid introducing a I/R negative impedance typical of many DC/DC converters.
FIG. 4 is a plot showing a simulated input voltage waveform 402 and corresponding input current waveform 404 for the power converter 300 of FIG. 3 that combines the 3C&6D current steering network 360 with the boost valley filling circuit 340 . As can be seen by comparing the plot of FIG. 4 with the plot of FIG. 2 for the prior art device, not only are the harmonic components of the input current waveform improved relative to the prior art device shown in FIG. 1 , but the peak value of the current is suppressed. Here the DC/DC converter 390 is a constant power load and appears as a pure resistive impedance for the PFC stage. The 3C&6D current steering network 360 of the power converter 300 of FIG. 3 generates a less harmonic input current wave shape than the prior art 2C&3D network of FIG. 1 .
FIG. 5 shows another embodiment of a power converter 500 configured differently than in the embodiment of FIG. 3 . The PFC front end 510 of power converter 500 of FIG. 5 includes a 3C&6D current steering network 360 but does not implement the valley filling circuit. In this regard, switch (S 3 ), and diode (D 6 ) are not included in power converter 500 . Instead, inductor (L 1 ) 342 is connected directly with node 302 .
FIG. 6 is a plot showing a simulated input voltage waveform 602 and corresponding input current waveform 604 for the power converter 500 of FIG. 5 with the 3C&6D current steering network 360 without a boost valley filling circuit. As can be seen by comparing the plot of FIG. 6 with the plot of FIG. 4 , the input harmonics are slightly increased but are still acceptable for many applications and represent an improvement over the prior art device of FIG. 1 that employs a 2C&3D current steering circuit rather than a 3C&6D current steering network and a constant power load which has a negative input impedance following the PFC stage. However, the absence of the valley filling circuit means that discontinuities 606 around the zero crossing points of the input current waveform 604 are not filled in as is the case with the power converter 300 of FIG. 3 . Nevertheless, the presence of such discontinuities 606 may be acceptable for a number of applications.
FIG. 7 shows another embodiment of a power converter 700 configured differently than in the embodiment of FIG. 3 . The PFC front end 710 of power converter 700 of FIG. 7 includes a 2C&3D current steering network 760 (instead of 3C&6D current steering circuit) along with the valley filling circuit 340 . In this regard, the 2C&3D current steering circuit includes two capacitors (C 9 and C 11 ) 362 and 366 and three diodes (D 9 , D 12 and D 13 ) 370 , 376 and 378 arranged in a network having four nodes 302 , 304 , 380 and 384 . Capacitor (C 9 ) 362 is connected to diode (D 9 ) 370 at node 302 and to diode (D 12 ) 376 and diode (D 13 ) 378 at node 380 . Capacitor (C 11 ) 366 is connected to diode (D 9 ) 370 and diode (D 12 ) 376 at node 384 and to diode (D 13 ) 378 at common node 304 . Diode (D 9 ) 370 is connected to capacitor (C 9 ) 362 at node 302 and to diode (D 12 ) 376 and capacitor (C 11 ) 366 at node 384 . Diode (D 12 ) 376 is connected to diode (D 13 ) 378 and capacitor (C 9 ) 362 at node 380 and to diode (D 9 ) 370 and capacitor (C 11 ) 366 at node 384 . Diode (D 13 ) is connected to diode (D 12 ) 376 and capacitor (C 9 ) 362 at node 380 and to capacitor (C 11 ) 366 at common node 304 .
FIG. 8 is a plot showing a simulated input voltage waveform 802 and corresponding input current waveform 804 for the power converter 700 of FIG. 7 with the 2C&3D current steering network 760 and the boost valley filling circuit 340 . As can be seen by comparing the plot of FIG. 8 with the plot of FIG. 4 , the input harmonics are slightly increased but are still acceptable for many applications and represent an improvement of the input harmonics as compared with the prior art device of FIG. 1 that lacks a DC/DC converter following the PFC stage.
FIG. 9 shows another embodiment of a power converter 900 configured differently than in the embodiment of FIG. 7 . The PFC front end 910 of the power converter 900 of FIG. 9 includes a 2C&3D current steering network 760 similar to that of power converter 700 but does not implement a valley filling circuit. In this regard, switch (S 3 ), and diode (D 6 ) are not included in power converter 900 . Instead, inductor (L 1 ) 342 is connected directly with node 302 .
FIG. 10 is a plot showing a simulated input voltage waveform 1002 and corresponding input current waveform 1004 for the power converter 900 of FIG. 9 with the 2C&3D current steering network 760 and without a boost valley filling circuit. As can be seen by comparing the plot of FIG. 10 with the plot of FIG. 8 , the input harmonics are slightly increased but are still acceptable for many applications and represent an improvement over the prior art device of FIG. 1 that employs a 2C&3D current steering circuit with a constant power load which has a negative input impedance following the PFC stage. However, the absence of the valley filling circuit means that discontinuities 1006 around the zero crossing points of the input current waveform 1004 are not filled in as is the case with the power converter 700 of FIG. 7 . Nevertheless, the presence of such discontinuities 1006 may be acceptable for a number of applications.
The plots of FIGS. 4 , 6 , 8 and 10 are based on various exemplary components having specified electrical characteristics that may be employed in the differently configured power converters 300 , 500 , 700 and 900 . However, the various embodiments are not limited to the exemplary capacitance, inductance, resistance, and threshold voltage (V TH ) values for the various capacitors, inductors, resistors and diodes included in the power converters 300 , 500 , 700 and 900 and such values may be varied as appropriate for different applications.
While various embodiments of the present invention have been described in detail, further modifications and adaptations of the invention may occur to those skilled in the art. However, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the present invention. | An input current shaping AC to DC converter with PFC front end that reduces input current harmonics is provided. In one embodiment, an AC to DC converter connectable with an alternating current source and operable to output a direct current has a PFC front end followed by a DC/DC converter. The PFC front end reduces harmonic components present in an input current waveform received by the PFC front end from the alternating current source and includes current steering circuitry and, optionally, valley filling circuitry. The DC/DC converter is one that presents pure resistive input impedance to the PFC front end. The DC/DC converter outputs the direct current to a load connected thereto. | 8 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.