description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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FIELD OF INVENTION
[0001] This invention relates to portable workstations for working on craft and hobby projects such as bead stringing or bead weaving, while supporting the projects on the user's lap.
BACKGROUND OF THE INVENTION
[0002] It has been found convenient to support projects, such as beadwork projects on a simple support, such as holding the project in the user's lap. In this way, the projects can be enjoyed in a wide variety of informal settings, with a minimum of extra time required for equipping an area with a more formal work place. As those familiar with beadcrafting and other similar activities are aware, the raw materials required for a project are usually supplied in bulk quantity, with different types of materials being segregated one from the other. For example, bead weaving or bead stringing may require beads of different colors, sizes and shapes. Bead trays and holders, such as those described in U.S. Pat. Nos. 5,636,743 and 6,571,955 are helpful in keeping the different work pieces separate, while making the work pieces readily available to a user.
[0003] Several problems have been observed with informal lap-supported workstations. Accidental spills arising in a transportation environment or due to incidental contact with pets or children can require a considerable time investment to correct. The need has thus arisen for a system for organizing different groupings of small parts while providing convenient storage in between work sessions. Also, it is desirable to package a craft project with materials used later to provide a lap support for assembling the project.
SUMMARY OF THE INVENTION
[0004] The present invention provides a novel and improved portable workstation that provides advantages over the construction, mode of operation and use of prior art work aids, while minimizing the disadvantages associated with such items. One embodiment of a portable workstation according to principles of the present invention arranges and maintains parts in a grouping, despite movement of the workstation. The workstation includes a base with a base body and at least one receptacle, such as a channel or a compartment, offset from the base body for holding the parts. The base body has a border surrounding the receptacle. A cover includes a cover body and at least one offset portion that is offset from the cover body, and that is surrounded by a border. The border of the base body engages the border of the cover body so as to maintain the receptacle spaced from the offset portion while confining the parts within the receptacle despite movement of the portable workstation.
[0005] In another embodiment, multiple groups of parts are maintained in separate groupings, despite movement of the workstation. In this embodiment, the base includes a plurality of receptacles offset from the base body, each surrounded by a border, and the cover includes a plurality of offset portions, each surrounded by their respective borders. The borders of the base body engage the borders of the cover body so as to maintain the receptacles spaced from the offset portions while separating contents of the receptacles, despite movement of the portable workstation.
[0006] Several variations are possible. For example, the receptacles formed in the base and the offset features formed in the cover may define a channel to arrange parts in a linear series or a compartment for holding a bulk quantity of parts. The cover offset portion may be either convex or concave. The cover may interfit with the base, and may be transparent so as to enable viewing of the parts without disturbing their groupings. If desired, locks, such as snap locks, can be provided to maintain secure engagement of the cover and base. The cover and base may be provided with stiffening features to ensure confinement of the parts within respective channels and compartments when the cover and base are snapped together, even if the workstation is moved or tipped on its side.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] In the drawings:
[0008] FIG. 1 is an exploded perspective view of a portable workstation;
[0009] FIG. 2 is a cross-sectional view taken along the line 2 - 2 of FIG. 1 ; and
[0010] FIG. 3 is a cross-sectional view similar to that of FIG. 2 , but showing the portable workstation fully assembled.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0011] The invention disclosed herein is, of course, susceptible of embodiment in many different forms. Shown in the drawings and described hereinbelow in detail are preferred embodiments of the invention. It is understood, however, that the present disclosure is an exemplification of the principles of the invention and does not limit the invention to the illustrated embodiments.
[0012] Moreover, for ease of description, a portable workstation embodiment of the present invention is described below in its usual assembled position as shown in the accompanying drawings and terms such as upper, lower, horizontal, longitudinal, etc. may be used herein with reference to this usual position. However, the portable workstation may be manufactured, transported, sold or used in orientations other than that described and shown herein.
[0013] Referring now to the drawings and initially to FIG. 1 , the portable workstation 10 is particularly suitable for activities involving relatively large numbers of small sized parts, such as beads which must be assembled together by stringing, or in some other manner. The portable workstation according to principles of the present invention should be desirable to beadcrafters engaged in activities such as bead weaving and bead stringing. Workstation 10 includes a base 12 and a cover 14 .
[0014] Preferably, the base and cover are each monolithically formed of molded plastic or other suitable material. Alternatively, construction materials such as sheet metal, paper and hybrid combinations of paper and other materials could also be used. If desired, one or more coatings can be applied to the base or cover. For example, the base may be covered with a flock material. It is a generally preferred, however, that at least the cover 14 is made of transparent material, and left uncoated. Further, it is generally preferred that the cover 14 be made of sufficiently thick material so as to be relatively rigid when formed in the fashion illustrated. It is generally preferred that cover 14 and base 12 be formed of thermoplastic material that is vacuum formed to provide a number of features that are employed to add functionality as well as rigidity to the base 12 , as well as the cover 14 .
[0015] As can be seen in FIG. 1 , the base 12 of workstation 10 , and the cover 14 have a generally rectangular shape, although other shapes may be used, as desired. Also, workstation 10 has a relatively small thickness or height compared to its surface dimensions, although the workstation could be made to other proportions. As shown in the Figures, cover 14 has a generally flat planar body 18 that extends to the outer periphery of the cover. A sidewall 20 depends from body 18 and is terminated with an outwardly extending flange 22 . Preferably, the sidewall 20 and flange 22 have rounded edges. A spaced apart series of upraised channels 24 - 30 are offset, i.e. set above cover body 18 . In the illustrated embodiment, channels 24 - 28 are nested one within the other, and channel 30 is positioned to one side of the channels 24 - 28 , adjacent the bottom edge of the workstation.
[0016] Referring again to FIG. 1 , base 12 has a generally flat planar body 34 that extends generally to the outer periphery of the base. A sidewall 36 depends from body 34 and is terminated with an outwardly extending stepped flange 38 having inner and outer horizontal stepped surfaces 40 , 42 . Preferably, the sidewall 36 and stepped flange 38 have rounded edges. As can be seen, for example, in FIG. 3 , stepped flange 38 provides a cushioning or shock absorbing for base 12 . This prevents parts carried on base 12 from becoming dislodged with a slight bumping inadvertently applied to the base.
[0017] Base 12 has a number of features, preferably different types of receptacles, all of which are preferably offset below base body 34 . For example, receptacles in the form of channels 44 - 48 are spaced-apart and nested one within another and channel 50 is separately located, adjacent the workstation bottom edge. In addition, receptacles in the form of compartments 52 , 54 are located at the center. of the workstation, adjacent a third compartment 56 . Corner compartments 58 , 60 are located adjacent ends of channel 50 , at the workstation bottom edge. It is generally preferred that all of the channels 44 - 50 and the compartments 52 - 60 be separated one from the other by intervening peripheral surfaces which, in the preferred embodiment, comprise portions of base body 34 . If desired, base 12 can be provided with intervening body structures that do not lie in a common plane.
[0018] It is generally preferred that the channels and compartments provide different types of organization for the workpieces or parts employed by a user. For example, workstation 10 is useful in the field of bead crafting. Bulk quantities of various working parts, such as different size and color beads, chain links and string elements must be accommodated while various parts are assembled in a work in progress. It is important that a user be allowed to interrupt an ongoing project without concern as to whether the parts may unintentionally become mixed together, as might occur if the workstation is accidentally bumped or otherwise disturbed. Although not necessary, it is generally preferred that the channels be sized and shaped to arrange given parts in a linear series, ready for assembly. For example, it has been found helpful to allow a user to arrange parts in a trial pattern or linear series, prior to stringing. As can be seen, for example, in FIGS. 2 and 3 , the channels 44 - 50 have rounded bottom portions and rounded sidewalls that direct beads placed therein to become arranged in a linear series. Accordingly, compartments 52 - 60 are conveniently located nearby to provide a ready supply of beads and other working parts.
[0019] As mentioned, it is generally preferred that the channels be maintained separate one from the other, and from the compartments, as well. As can be seen in FIG. 2 , channels 44 - 48 are separated by portions of base body 34 . Thus, the contents of each channel are separately confined. Additional confinement is also provided by cover 14 , when the cover is engaged with the base, as shown in FIG. 3 , so as to superimpose cover channels 24 - 28 over base channels 44 - 48 to thereby form spaced apart tubular enclosures or workstation channels. As indicated in FIG. 3 , it is generally preferred that, with the cover 14 and base 12 interengaged, the base body 34 engages the cover body 18 so as to surround each base channel and each base compartment with a sealed or enclosed perimeter, to form enclosed workstation channels and compartments. In this manner, the contents of each workstation channel and each workstation receptacle are separately confined, preventing their intermingling one with the other, despite movement of the assembled workstation.
[0020] In order to quickly and easily maintain alignment of the cover channels and base channels, and to ensure that substantially the entire periphery of each channel and compartment is adequately enclosed or sealed, workstation 10 includes features for registering the cover 14 with the base 12 , in the desired manner. For example, it was mentioned that the cover and the base have rounded corners. It is generally preferred that the radius of curvature for the cover and base complement one another, and that one, such as the base, be dimensioned for internesting within the other. In addition, sidewalls 20 , 36 provide guiding surfaces as the cover and the base are interengaged, and horizontal surface 40 of stepped flange 38 provides a stop when engaged with flange 22 of cover 14 . As can be seen in FIG. 3 , a gap 64 is located between flange 22 and step surface 42 , to easily allow the fully engaged cover and base to be pulled apart, for opening the workpiece.
[0021] If desired, the channels of the cover and base can be sized similarly, although it is generally preferred that the channels be made to have different cross-sectional sizes so as to accommodate a variety of differently sized parts, ensuring a well defined array for loose parts inserted therein. The channels of the cover are generally rounded to accommodate rounded beads without pinching. In contrast, the channels of the base are less rounded, with straight sidewalls and a smaller radius, but still rounded, bottom wall. This feature provides a trapping of rounded beads within the base channel, quickly bringing the beads to an extended centerline position, as desired.
[0022] As can be seen for example in FIG. 1 , a series of locks or inwardly raised lock tabs 68 are located about the periphery of cover sidewall 20 . The lock tabs are received in depressions or detents 72 formed in base sidewall 36 with a snap fit, providing a snap lock for the cover and base. With lock tabs 68 engaged with detents 72 , body 18 of cover 14 is maintained in contact with body 34 of base 12 , ensuring a seal, preferably a continuous seal for the periphery of each channel and compartment of the workstation. Referring to FIGS. 2 and 3 , it can be seen that the lock tabs 68 are rounded, as are the detents 72 . This is important during opening of the workstation, to avoid a sudden release of stored energy that might disrupt the workstation contents. As will be appreciated by those skilled in the art, cover sidewall 20 provides an inward bias force to lock tabs 68 . This bias force can be adjusted, for example, by adjusting the thickness of the cover sidewall to further ensure a secure engagement of the cover and base, but without a jerky or sudden energy release upon opening of the workstation. It should be noted in this regard, that the relatively large size of the flange 22 and the step surface 42 which cooperate to form gap 64 (see FIG. 3 ) add substantially to the control of forces occasioned when cover 14 is separated from base 12 .
[0023] As mentioned, it is generally preferred that the cover and base be made substantially rigid, thus adding to the ensured enclosure of the workstation channels and compartments. The presence of offset features such as the channels 24 - 30 of cover 14 and the channels 44 - 50 and compartments 52 - 60 of the base further adds to the desired rigidity, especially when the cover and base are molded, using vacuum forming or other techniques. Although internested channel features have been described, other arrangements are also possible. For example, adjacent channels need not have similar shapes. If desired, additional locks could be provided within the interior of the cover and the base, although this has not been found to be necessary.
[0024] Other and further configurations, modifications and embodiments of the present invention will be apparent to those skilled in the art from the present teachings and disclosures. The present invention is not limited to the present illustrative embodiments. Changes can be made therein without departing from the spirit and scope of the invention. | A portable workstation for beadcrafting operations is provided. The workstation includes a base including at least one receptacle for holding parts such as beads, preferably in a desired pattern. A cover interfittable with the base includes a seal portion that engages and surrounds the receptacle so as to maintain the parts in their desired position, despite movement of the workstation. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method for bleaching pulp. More specifically, the present invention relates to a method of bleaching pulp using ozone in which the ozone is more effectively dispersed and dissolved in a low consistency pulp.
[0003] 2. Brief Description of the Prior Art
[0004] During the past 10-15 years the bleaching of pulp in the Kraft Process has undergone many changes. These changes were mainly prompted by environmental concerns of the quality of the effluent being discharged from paper mills. Of main concern was the bleach plant effluent, which contained polychlorinated dibenzodioxines and dibenzofurans among other compounds. The measurement of AOX was used as an indicator of the concentration of these compounds and the test was quickly adopted as a standard for legislation.
[0005] It was soon determined that the chlorine used in bleaching was a factor in high AOX values, while values could be reduced by lowering the quantity of chlorine used. Chlorine dioxide was substituted for chlorine and reduced AOX values was the result. A typical bleaching sequence became C/D.Eo.D.E.D. with at least 50% of the chlorine being replaced by chlorine dioxide on an equivalence basis. Some paper mills have eliminated chlorine entirely by using D.Eo.D.E.D. or O.D.Eo.D.E.D. sequences.
[0006] Ozone is a powerful bleaching agent used in many bleach plants throughout the world to bleach Kraft Pulp and recycled fibers. It has recently been discovered that ozone can replace chlorine dioxide and achieve the same brightness and pulp quality. It has been found that 1 kg of ozone can essentially replace 2 −4 kgClO2 . This results in lower cost bleaching sequences such as O.Z/D.Eop.D.E.D, O.D/Z.Eop.D.X.D, D/Z.Eop.D.E.D. and others. The use of ozone (O 3 ) can become more attractive, however, if a more efficient and cost effective method can be found to better disperse and dissolve O 3 into an existing bleaching sequence. The usual method of bleaching with ozone comprises dispersing ozone into a medium consistency pulp using a pump, mixer and retention tube. This is carried out at a pressure of 150 psig and requires a compressor to add the ozone.
[0007] Medium consistency pulp generally contains a cellulose fiber suspension of from 8-15%, that when exposed to high shear forces acquires fluid properties that permits it to be pumped. High shear mixers enable gases to be dispersed and dissolved in medium consistency pulps.
[0008] A typical medium consistency ozone bleaching process generally consists of pumping pulp to a mixer where ozone is added. The gas dispersion in the pulp is then sent to a vertical retention tube where at least 90% of the ozone dissolves and reacts during a hydraulic residence time of 3060 secs. If the ozone utilization is low, then a second mixer may be added. On discharge from the retention tube, gas is separated from the pulp and the excess ozone in the gas is sent to an ozone destruct unit.
[0009] To achieve high utilization of ozone in medium consistency bleaching, a pump and mixer(s) are used that are driven by high HP motors and the power requirement can reach 0.5-1.0 HP/ton pulp/day. Typically pulp is bleached with an ozone charge of about 5 kg ozone/ton pulp, and this is added in a single stage. If higher charges of ozone are required then more than a single stage is necessary, e.g. 10 kg/ton requires two stages. The limiting factor in ozone addition is the volume of gas that can be dispersed and dissolved in the pulp with high ozone utilization. For medium consistency processes it has been found that a high utilization of ozone can be achieved if the volume ratio of gas in the total fluid mixture does not exceed 30%. For ozone generated at a concentration of 10% w/w and operating at a pressure of 150 psig, the maximum charge added is 5 kg of ozone/ton of pulp. If the ozone concentration is raised to 12% this charge can be raised to 6 kg/ton with the same ozone utilization.
[0010] An alternative to medium consistency pulp technology is that of using high consistency pulp. In this process fibers are dewatered to a consistency of 25-40% by passing medium consistency pulp through a press. As well as dewatering the fibers, the pulp is compressed and then fluffed in order to have good contact between gas and fibers. The pulp is then introduced into a reactor where it is contacted with ozone for a period of 1-3 minutes at a pressure of 5 psig. After ozonation, the pulp is degassed and diluted with wash water before passing on to a washing stage.
[0011] When this process was first started there were reports of uneven bleaching, but with improved reactor design this was overcome. An advantage of this process is that it does not require high concentrations of ozone, as using 6.0% w/w works very well. However the high consistency process is not widely accepted because of the mechanical complexity of the equipment and the high power requirement for dewatering the pulp.
[0012] Another possible technique for bleaching pulp involves low consistency pulp. Low consistency pulp employs a cellulose fiber suspension of 1-5% that has a viscosity greater than water, but can be pumped using conventional pumps without the need of a high shearing effect. Chlorination is generally carried out in a low consistency process and in many processes chlorine dioxide is also added to low consistency pulp slurries. However there has been little discussion of ozonation at low consistency.
[0013] Laboratory studies have been carried out on ozonating pulp in bubble columns using pulp slurries around 0.5% concentration. This method worked well, but with columns of a height of 25 m, the gas residence time was very short and ozone utilization low. Furthermore, ozone concentrations in the gas applied were low, 2-3% w/w.
[0014] This low concentration required large volumes of gas to obtain the desired ozone charge. The low concentration also led to low mass transfer rates. The net effect of this was poor ozone utilization, and this together with the dilute pulp slurry has made the consideration of using ozone with low consistency pulp commercially unattractive.
[0015] Up to this point, therefore, there has been no commercial process devoted to ozone bleaching of low consistency pulp. While some laboratory studies have been carried out at consistencies of about 0.5% using unpacked columns and adding the ozone by a diffuser at the bottom, such a process is not considered to be practical for commercial use. Furthermore, there are reports that O 3 consumption increases due to decomposition in water. Also the favored technology for bleaching uses medium consistency pulps and there have been no reported attempts to carry out low consistency ozone bleaching on an industrial scale.
[0016] Low consistency pulp, however, is easier to pump. Dispersing ozone onto it, because of its low viscosity, would therefore require less power. This can be done before or after a low consistency D stage or a medium consistency D stage. In the latter case this is carried preferably out in a downflow tower and at the bottom of the tower the pulp is diluted to low consistency in order to pump it to the next process step.
[0017] Hence if ozone can be effectively and efficiently dispersed and dissolved in low consistency pulp, the use of low consistency technology with ozonation offers a low cost method which can be used to retrofit an existing bleaching process.
[0018] Therefore, it is an object of the present invention to provide a novel process and apparatus for bleaching pulp using ozone.
[0019] Another object of the present invention is to provide a method for more effectively and efficiently dispersing and dissolving ozone into low consistency pulp so as to make low consistency pulp bleaching technology with ozone viable.
[0020] Still another object of the present invention is to provide an efficient process and apparatus for bleaching employing low consistency technology, whereby ozone is used as the bleaching agent.
[0021] These and other objects of the present invention will become apparent to the skilled artisan upon a review of the following disclosure, the Figures of the Drawing, and the claims appended hereto.
SUMMARY OF THE INVENTION
[0022] In accordance with the foregoing objectives, there is provided a novel process and apparatus for bleaching pulp with gaseous mixtures comprising ozone. The process of the present invention comprises first preparing a slurry of cellulosic pulp of a low consistency, i.e., a consistency of fibers of from about 1-5 weight %. Ozone is then mixed with the pulp slurry using high shear mixing. This high shear is preferably created using a mixer designed for medium consistency pulp bleaching, i.e., a mixer generally used for medium consistency pulps. Such high shear (high-intensity) mixers are well known in the art. Using the high shear mixing has been found to allow the ozone to be effectively and efficiently dispersed and dissolved into the low consistency pulp, even while the pulp mixture remains at low pressure. The ozone is then maintained in contact with the cellulosic fibers for a time sufficient to bleach the fibers, before separation occurs.
[0023] The process of the present invention offers one the energy benefits of using low consistency technology, in combination with the benefits of using ozone to bleach the cellulosic pulp. The ozone bleaching step of the present invention can be combined in an overall bleaching process with other bleaching steps. For example, the ozone bleaching step can be used either before or after a chlorine dioxide bleaching step. The ozone bleaching step can also be followed by a different bleaching step, e.g., with hydrogen peroxide.
[0024] Another advantage of the present invention is that when ozone is compressed at higher pressures, it breaks down to oxygen (O 2 ). Thus, if a lower pressure can be used, more ozone should be available. Ozone also has a short half-life before converting to oxygen, therefore, the present invention with its short mixing time helps ensure more ozone is available for bleaching purposes.
[0025] In another embodiment, there is provided a system for a reactor for bleaching pulp at low consistency with ozone. The reactor comprises a high shear mixer wherein ozone is dispersed into a pulp slurry having a consistency in the range of from 1 to 5 wt %, and a retention tube connected to the mixer which operates at a pressure of from 20 to 60 psig, and wherein the ozone bleaches the pulp in the pulp slurry.
BRIEF DESCRIPTION OF THE DRAWING
[0026] [0026]FIG. 1 of the Drawing depicts a reactor for bleaching pulp at low consistency with ozone, which uses a pressurized ozone generator.
[0027] [0027]FIG. 2 of the Drawing depicts a reactor for bleaching pulp at low consistency with ozone employing an ozone compressor.
[0028] [0028]FIG. 3 of the Drawing depicts a low consistency ozone bleaching process carried out before a chlorine dioxide bleaching step.
[0029] [0029]FIG. 4 of the Drawing depicts an alternative low consistency ozone bleaching process carried out before a chlorine dioxide bleaching step.
[0030] [0030]FIG. 5 of the Drawing depicts a low consistency ozone bleaching process wherein the ozone bleaching step is carried out after a chlorine dioxide bleaching step.
[0031] [0031]FIG. 6 of the Drawing depicts an alternative low consistency ozone bleaching process using an ozone bleaching step that is carried out after a chlorine dioxide bleaching step.
[0032] [0032]FIG. 7 of the Drawing graphically depicts the D/Z delignification efficiency for various reactor/mixers at low consistency (2.5-3.5 wt %).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] The ozone employed in the process of the present invention can be of any source. Preferably, the ozone is generated on-site using an ozone generator, to thereby produce ozone from oxygen at a concentration in the range of from about 5 to 20 wt %, more preferably in the range of from about 10 to 20 wt %, and most preferably in the range of from about 10 to 15 wt %. Ozone generators are well known, and are generally operated at a pressure in the range of from about 20-60 psig, and more preferably in the range of from 30-40 psig.
[0034] The ozone/oxygen mixture is preferably introduced into the high shear mixer through a valve, which can be used to control the flow of the gas mixture into the high shear mixer. The ozone/oxygen gas mixture can be compressed, if so desired, prior to introduction into the high shear mixer. The ozone compressor generally operates at a pressure ranging from 20-150 psig, and more preferably in the range of from 30-40 psig.
[0035] The high shear mixer can be any high shear mixer well known to the art of pulp bleaching. Such mixers are described, for example, in Pulp Bleaching—Principals and Practice by Carlton W. Dence and Douglas W. Reeve, TAPPI Press, 1996, pages 549-554. In high shear (high intensity) mixers, the pulp and ozone gas mixture are mixed by passage through zones of intense shear. They induce microscale mixing in the entire volume and not only in specific locations as in a continuous stirred reactor. The high shear is created by imposing high rotational speeds across narrow gap, generally between the rotor blades and reactor casing, through which the pulp suspension flows. Although there are design differences among the high shear mixers conventionally known, they all attempt to fluidize the suspension in the mixture working zone. The high shear rate insures flock disruption and good fiber scale mixing.
[0036] The present invention employs a high shear mixer, and many different high shear mixers used for pulp bleaching are known. Some of those known include the Ahlstrom Ahlmix, the Ahlstrom MC pump, the Beloit-Rauma R series, the Ingersoll-Rand Hi-Shear and the Impco Hi-Shear mixer from Beloit Corporation. Others include the Kamry MC, the Kamry MC Pump (Pilot) the Sunds SM and Sunds T mixers. The Quantum mixer is also an acceptable high shear mixer. All such mixers are known in the art and are generally used to mix medium consistency pulp suspensions.
[0037] Mixers can be compared based on energy applied (MJ/ton of pulp) and power dissipation (W/m 3 ). J. R. Bourne in Chem. Eng. Sci., 38(1):5 (1983) states that all devices operated at the same power unit volume will generate the same rate of micromixing. This assumes energy applied equals energy dissipated, which is not true for all mixers. The distribution of power throughout the suspension is as important as its total. Examples of different mixers and the energy and power values for a given pulp consistency are as follows:
Consistency Power Dissipation Energy Mixer Type (wt %) (W/m 3 ) (MJ/ton) Hand Mixing 3 2 × 10 4 120 CSTR 2-3 600 5-9 Quantum (high 5 4.5 × 10 5 63 shear) Mixer High Shear 10 1.8 × 10 6 180
[0038] Using the measured energy dissipation rate and a correlation for the apparent viscosity of a pulp suspension given by Bennington in “Mixing Pulp Suspensions”, PhD. thesis, The University of British Columbia, Vancouver, B.C., 1988, τ is 0.02 sec. for a 10% consistency in a typical high shear mixer. In a CSTR operating at 3% consistency, τ=0.4 sec., but varies locally with the mixer. τ represents the mean lifetime of turbulent eddies.
[0039] The pulp suspension of the present invention that is provided to the high shear mixer is of low consistency. This means that the amount of pulp contained in the suspension ranges from about 1 to 5 wt %. More preferably, the amount of pulp in the suspension ranges from 2 to 4 wt %. Preferably, the temperature of the pulp slurry entering the mixer is in the range of from about 20-80° C., more preferably from about 40-60° C. The ozone charge added to the pulp is in the range of from about 2-10 kg/ton, more preferable from about 5-6 kg/ton.
[0040] Once in the high shear mixer, the ozone and pulp suspension are mixed in the high shear mixer in the range of from about 0.01 seconds to 10 seconds, and more preferably in the range of from about 0.1 seconds to 4 seconds. Once the mixing has taken place, the pulp suspension is then passed to a bleaching or reactor station, which is preferably a retention tube, wherein the residence time ranges from about 1 to 10 minutes, more preferably from about 2-5 minutes. It is in the retention tube that the bleaching of the pulp actually takes place by the ozone. Because of the use of the high shear mixer, and the short time in which it takes to dissolve the ozone, as well as the low pressures under which the mixing and retention tube can operate, more ozone is available to do the bleaching of the low consistency pulp. Accordingly, the present invention provides surprising results with regard to excellent bleaching.
[0041] Referring to FIG. 1, there is illustrated a reactor for bleaching pulp at low consistency with ozone by using a pressurized ozone generator. It consists of a medium consistency mixer where ozone is dispersed in the low consistency pulp followed by a retention tube operating at a pressure between 20-60 psig where ozone gradually dissolves and bleaches the pulp.
[0042] Air is introduced by line 1 into an air separation unit 2 where oxygen is separated from air. Oxygen passes by line 3 into an ozone generator 4 and is converted to ozone, and this passes through line 5 into a control valve 6 that automatically regulates the gas flow by gas flowmeter 7 . Ozone gas is introduced to the mixer 9 by an inlet line 8 and is dispersed into the low consistency pulp. Pulp slurry passes through line 20 into pump 21 where it is pumped into the mixer 9 and mixed with the ozone-oxygen mixture.
[0043] The pulp slurry-gas mixer passes into the column 23 that is held under pressure by a back pressure valve 24 . The ozone-oxygen mixture dissolves and reacts with the pulp slurry before exiting through valve 24 into line 25 .
[0044] The pulp slurry-gas mixture flows into a separator vessel 26 where gases are separated from the pulp and flow through line 27 into an ozone destruct unit 28 , where the ozone is destroyed and the remaining gases leave through line 29 . The pulp slurry leaves the separator through line 30 and flows into pump 31 where it is pumped to the next stage through line 32 .
[0045] [0045]FIG. 2 illustrates a reactor for bleaching pulp at low consistency with ozone by using an ozone compressor. It comprises generally of a medium consistency mixer where ozone is dispersed in the low consistency pulp, followed by a retention tube operating at a pressure between 20-60 psig where ozone gradually dissolves and bleaches the pulp.
[0046] Air is introduced by line 100 into an air separation unit 102 where an oxygen rich stream is separated from air. Oxygen passes by line 103 into an ozone generator 104 and is converted to ozone and this passes through line 105 into an ozone compressor 110 where the gas mixture is compressed. From here it flows to a control valve 106 that automatically regulates the gas flow by gas flowmeter 107 . Ozone gas is introduced to the mixer 109 by an inlet line 108 and is dispersed into the low consistency pulp. Pulp slurry passes through line 120 into pump 121 where it is pumped into the mixer 109 via line 122 and mixed with the ozone-oxygen mixture.
[0047] The pulp slurry-gas mixture passes into the column 123 that is held under pressure by a back pressure valve 124 . The ozone-oxygen mixture dissolves and reacts with the pulp slurry before exiting through valve 124 into line 125 . The pulp slurry-gas mixture flows into a separator vessel 126 where gases are separated from the pulp and flow through line 127 into an ozone destruct unit 128 , where the ozone is destroyed and the gases leave through line 129 . The pulp slurry leaves the separator through line 130 and flows into pump 131 where it is pumped to the next stage through line 132 .
[0048] [0048]FIG. 3 illustrates a low consistency ozone bleaching process in accordance with the present invention that includes an ozone bleaching stage before a chlorine dioxide bleaching stages. This uses a pressurized ozone generator to compress ozone before adding it to a mixer. This method avoids the use of a compressor to add compressed ozone to the mixer.
[0049] In the process, pulp of medium consistency is pumped through line 252 into a storage tank 251 . The pulp flows down the tank into a dilution zone 250 where it is diluted to a low consistency with dilution water added through nozzles 246 and 247 . Agitators 248 and 249 ensure that mixing is complete. The pulp slurry of consistency about 3% passes through line 220 into pump 221 where it is pumped into the mixer 209 and mixed with the ozone-oxygen mixture. Air is introduced by line 201 into an air separation unit 202 where oxygen is separated from air. Oxygen passes by line 203 into a pressurized ozone generator 204 and is converted to ozone and this oxygen-ozone mixture passes through line 205 into a control valve 206 that automatically regulates the gas flow by gas flowmeter 207 . The ozone-oxygen gas mixture is introduced to the mixer 209 by an inlet line 208 and is dispersed into the low consistency pulp.
[0050] The pulp slurry-gas mixture passes into the column 223 , that is held under pressure by a back pressure valve 224 . The ozone-oxygen mixture dissolves and reacts with the pulp slurry before exiting through valve 224 into line 225 . The pulp slurry-gas mixture flows into a separator vessel 226 , where gases are separated from the pulp and flow through line 227 into an ozone destruct unit 228 , where the ozone is destroyed and the resulting gases leave through line 229 . The pulp slurry leaves the separator 226 through line 230 and flows into pump 231 , where it is pumped through line 232 into a mixer 234 where chlorine dioxide is added through line 233 before flowing by line 235 into the bottom of the bleaching tower 236 . The pulp rises to the top of the tower and overflows through line 237 into line 238 to a washer 239 . The pulp is washed with wash water added through line 240 and the washed pulp leaves the washer through line 241 . The dilution water separated from the pulp is collected in storage tank 242 , where it is removed through line 243 by pump 244 and is pumped through line 245 to the nozzles 246 and 247 , where it is added to the dilution zone 250 of the storage tank 251 .
[0051] [0051]FIG. 4 illustrates a low consistency ozone bleaching process involving an ozone bleaching stage in accordance with the present invention that is carried out before a chlorine dioxide bleaching stage. The process uses a compressor to compress ozone before adding it to the mixer.
[0052] In the figure, pulp of medium consistency is pumped through line 352 into a storage tank 351 . The pulp flows down the tank into a dilution zone 350 where it is diluted to a low consistency with dilution water added through nozzles 346 and 347 . Agitators 348 and 349 ensure that mixing is complete. The pulp slurry of consistency about 3% passes through line 320 into pump 321 where it is pumped through line 322 into the mixer 309 and mixed with the ozone-oxygen mixture. Air is introduced by line 301 into an air separation unit 302 where oxygen is separated from air. Oxygen passes by line 303 into an ozone generator 304 and is converted to ozone, and this oxygen-ozone mixture passes through line 305 into an ozone compressor 310 where it is compressed. From here it flows to a control valve 306 that automatically regulates the gas flow by gas flowmeter 307 . The ozone gas mixture is introduced to the mixer 309 by an inlet line 308 and is dispersed into the low consistency pulp.
[0053] The pulp slurry-gas mixture passes into the column 323 , which is held under pressure by a back pressure valve 324 . The ozone-oxygen mixture dissolves and reacts with the pulp slurry before exiting through valve 324 into line 325 . The pulp slurry-gas mixture flows into a separator vessel 326 where gases are separated from the pulp and flow through line 327 into an ozone destruct unit 328 , where the ozone is destroyed and the gases leave through line 329 . The pulp slurry leaves the separator through line 330 and flows into pump 331 where it is pumped through line 332 into a mixer 334 where chlorine dioxide is added through line 333 before flowing by line 335 into the bottom of the bleaching tower 336 . The pulp rises to the top of the tower and overflows through line 337 into line 338 to a washer 339 . The pulp is washed with wash water added through line 340 and the washed pulp leaves the washer through line 341 . The dilution water separated from the pulp is collected in storage tank 342 . It is removed through line 343 entering pump 344 and is pumped through line 345 to the nozzles 346 and 347 , where it is added to the dilution zone 350 of the storage tank 351 .
[0054] [0054]FIG. 5 depicts a low consistency ozone bleaching process stage in accordance with the present invention that is carried out after a chlorine dioxide bleaching stage. The process uses a pressurized ozone generator to produce compressed ozone before adding it to a mixer. This method avoids the use of a compressor to add compressed ozone to the mixer.
[0055] Pulp of medium consistency is pumped through line 452 into a storage tank 451 . The pulp flows down the tank into a dilution zone 450 where it is diluted to a low consistency with dilution water added through nozzles 446 and 447 . Agitators 448 and 449 ensure that mixing is complete. The pulp slurry, now of low consistency about 3%, passes through line 420 into pump 421 that discharges through line 422 into a mixer 424 where chlorine dioxide is added through line 423 . The pulp slurry-chlorine dioxide mixture passes through line 425 into the bottom of tower 426 , where it flows upwards consuming chlorine dioxide and bleaching the pulp. It overflows from the tower 426 in line 427 flowing into pump 428 , which discharges into mixer 409 where the oxygen-ozone mixture is added.
[0056] Air is introduced by line 401 into an air separation unit 402 where oxygen is separated from air. Oxygen passes by line 403 into an ozone generator 404 and is converted to ozone and this passes through line 405 into a control valve 406 that automatically regulates the gas flow by gas flowmeter 407 . Ozone gas is introduced to the mixer 409 by an inlet fine 408 and is dispersed into the low consistency pulp. The pulp slurry-gas mixture passes into the column 429 , which is held under pressure by a back pressure valve 430 . The ozone-oxygen mixture dissolves and reacts with the pulp slurry before exiting through valve 430 into line 431 . The pulp slurry-gas mixture flows into a separator vessel 432 , where gases are separated from the pulp and passed through line 433 into an ozone destruct unit 434 , in which the ozone is destroyed and the resultant gases leave through line 438 . The pulp slurry leaves the separator through line 436 and flows into pump 437 , where it is pumped to the washer 439 through line 460 . The pulp is washed with wash water added through line 440 and leaves through line 441 . The washings are collected in tank 442 and leave through line 443 entering pump 444 and discharges via line 445 through nozzles 446 and 447 into the dilution zone 450 of the medium consistency storage tank 451 .
[0057] [0057]FIG. 6 illustrates a low consistency ozone bleaching process in accordance with the present invention that is carried out after a chlorine dioxide bleaching step. The process uses a compressor after the ozone generator to compress ozone before adding it to a mixer.
[0058] Pulp of medium consistency is pumped through line 552 into a storage tank 551 . The pulp flows down the tank into a dilution zone 550 where it is diluted to a low consistency with dilution water added through nozzles 546 and 547 . Agitators 548 and 549 ensure that mixing is complete. The pulp slurry, now of consistency about 3%, passes through line 520 into pump 521 and discharges through line 522 into a mixer 524 where chlorine dioxide is added through line 523 . The pulp slurry-chlorine dioxide mixture passes through line 525 into the bottom of tower 526 , where it flows upwards consuming chlorine dioxide and bleaching the pulp. It overflows from the tower in line 527 flowing into pump 528 and discharges into mixer 509 where the oxygen-ozone mixture is added. Air is introduced by line 501 into an air separation unit 502 where oxygen is separated from air. Oxygen passes by line 503 into an ozone generator 504 and is converted to ozone, and this passes through line 505 into a compressor 510 where the gas is compressed. The oxygen-ozone mixture passes through control valve 506 , which automatically regulates the gas flow by gas flowmeter 507 . The ozone gas mixture is introduced to the mixer 509 by an inlet line 508 , and is dispersed into the low consistency pulp.
[0059] The pulp slurry-gas mixture passes into the column 529 , which is held under pressure by a back pressure valve 530 . The ozone-oxygen mixture dissolves and reacts with the pulp slurry before exiting through valve 530 into line 531 . The pulp slurry-gas mixture flows into a separator vessel 532 , where gases are separated from the pulp and flow through line 533 into an ozone destruct unit 534 , wherein the ozone is destroyed and the resultant gases leave through line 535 . The pulp slurry leaves the separator through line 536 and flows into pump 537 where it is pumped to the washer 539 through line 538 . The pulp is washed with wash water added through line 540 and leaves through line 541 . The washings are collected in tank 542 and leave through line 543 entering pump 544 and discharges via line 545 through nozzles 546 and 547 into the dilution zone 550 of the medium consistency storage tank 551 .
[0060] The invention will be illustrated in greater detail by the following specific example. It is understood that the example is given by way of illustration and is not meant to limit the disclosure or the claims to follow. All percentages in the examples, and elsewhere in the specification, are by weight unless otherwise specified.
EXAMPLE 1
[0061] It has been found that most pulps bleach well giving increased brightness with little strength loss for an ozone charge of 5 kg of ozone/ton pulp. Taking this is as the basis of a design for a reactor, and assuming ozone is generated at a concentration of 12% w/w, the oxygen requirement is estimated as follows:
[0062] O 2 required=100*5/12=41.7 kg/ton of pulp.
[0063] This produces a mixture of O 2 +O 3 =5 kg O 3 +36.7 kg O 2 .
[0064] The volume of the gases at a pressure of 760 mms Hg, and temperature of 0° C. is 2.76 m 3 O 3 +30.40 m 3 O 2 .
[0065] Total gas volume=33.16 m 3 /ton of pulp.
[0066] If this is to be dispersed and dissolved in a pulp slurry having a consistency of 3%, volume of pulp slurry=100/3 m 3 /ton of pulp=33.3 m 3 /ton of pulp.
[0067] This consists of 1.0 m 3 pulp+32.3 m 3 of dilution water.
[0068] Hence it is required to dissolve and disperse 33.16 m 3 of gas in 33.3 m 3 of pulp slurry.
[0069] The ratio of gas to pulp slurry=33.16:33.3=about 1:1.
[0070] If all the O 3 dissolved in the dilution water, the solubility of the O 3 would have to be 5 kg/32.3 m 3 , or 155 g/m 3 .
[0071] If this reaction takes place at 50° C., the solubility of 12% w/w O 3 in water is as follows:
Total Pressure Partial Pressure O 3 Solubility O 3 (psia) (psia) (g/m 3 ) 14.7 1.22 13.2 24.7 2.05 22.2 164.7 13.67 147.9
[0072] If this is-compared to dispersing ozone in medium consistency pulp having a consistency of 10%:
[0073] Volume=1.0 m 3 pulp+9.0 m 3 dilution water=10.0 m 3 pulp slurry.
[0074] If 5 kg O 3 ton of pulp is dispersed and dissolved in the dilution water, O 3 applied=5 kg/9 m 3 =555 g/m 3 .
[0075] The gas to liquid ratio at a pressure of 760 mms Hg and 0° C. is 33.16:9, which is 3.7:1.
[0076] At a pressure of 150 psig, this ratio becomes 0.33:1
[0077] If this medium consistency equipment disperses ozone satisfactorily at a ratio of 0.33:1 for medium consistency pulp, it will be able to do the same for low consistency. Hence to reduce the gas:slurry ratio from 1:1 to 0.33, the gas volume must be reduced by a ratio of 1/0.33 m 3 . This corresponds to a pressure of 30 psig.
[0078] Based on the above calculations, it was decided that medium consistency equipment can be used for dispersing ozone into low consistency pulp at a pressure of 30 psig. This was confirmed by testing carried out in the Laboratory as follows:
[0079] Laboratory Studies
[0080] Trials were carried out in a Quantum Mark-5 Laboratory Mixer/Reactor. This was originally designed and operated with medium consistency pulp. For each run 90 grams of pulp having Kappa No=25.5 was used and a first bleaching stage at a temperature of 40° C. with a constant chlorine dioxide dosage of 14.5 kg/ton was carried out. Following this, 4.0-5.5% w/w ozone-oxygen mixture was then introduced at a pressure of 50-70 psig at a temperature of 40° C. During the ozone addition, the pulp was mixed for 5 seconds at high intensity using a Quantum mixer followed by subsequent intermittent mixing at a lower intensity (using a CSTR) for 5 minutes. The results are shown in Table 1 below:
TABLE 1 O 3 Charge O 3 Consumed O 3 Reacted Retention Time Pressure (kg/t) (kg/t) (%) (mins) (psig) 2.4 2.2 93.0 5 46 4.0. 3.9 95.0 5 55 6.1 5.8 95.1 5 52 7.3 7.0 95.9 5 65
[0081] This illustrates that equipment designed for dispersing gases in medium consistency pulp can also be used successfully for O 3 bleaching of low consistency pulp with high ozone utilization.
EXAMPLE 2
[0082] Tests were carried out on a Pilot Plant that was originally designed to use ozone to bleach a medium consistency pulp slurry. It consists of a pump that pumps the pulp into a pressurized high shear mixer. Ozone of concentration 12% w/w is compressed and added to the pulp slurry at the inlet of the mixer. The ozone gas mixture is dispersed in the pulp slurry where it reacts with the lignin. The slurry-gas mixture discharges into a column where the remaining ozone is consumed.
[0083] Results for a Softwood Pulp having Kappa No 31 , carried out at temperature 40° C. and a pulp consistency of 3.5%, are shown in Table 2 below:
TABLE 2 Ozone Pressure Charge Ozone Pressure Bottom Ozone Consumed Ozone Consumed to pulp inlet Mixer Tower in Mixer top Tower (kg/t) (psig) (psig) (%) (%) 6.3 30 20 87 99 6-3 90 80 94 99 6-3 110 100 99 99
[0084] These results demonstrate that a Mixer designed for dispersing ozone into a medium consistency pulp slurry can be used successfully for a low consistency pulp slurry and that it is possible to operate at lower pressures with good results.
EXAMPLE 3
[0085] Two runs of an ozone stage were performed on a brown stock kraft pulp at low consistency in a Pilot plant using a high intensity mixer. The runs were made to verify if the ozone stage efficiency (degree of delignification) and the consumption were equivalent for low and medium consistency pulp. The pulp used was a softwood kraft with an initial kappa number of 30.8 and ISO brightness of 27.9%.
[0086] In each run, the washed pulp was received at 33% consistency and diluted to 3.8% consistency in an agitated feed tank. Pulp slurry was then preheated to 40° C. with the injection of steam in the feed tank. At that temperature, concentrated (98%) sulphuric acid was added to the tank to adjust the pH of the pulp suspension to 2.5 before the ozone stage. Pulp slurry was pumped directly to the hopper of the positive displacement pump. This pump introduced pulp in the high pressure section of the pilot plant, where ozone gas was mixed with the pulp in a Impco high intensity mixer. The flow of the pulp into the high pressure section and the ozone charge and concentration were kept constants.
[0087] After compression, the ozone gas stream was introduced into the pulp suspension trough a sintered metal sparger (20 micron porosity) located between the feed pump discharge and the Impco high intensity mixer inlet. The residence time in that mixer was approximately 0.05 second. The conditions for each run are described in Table 3.
[0088] The pulp was sampled approximately 1 meter from the ozone injector point after passing through the high intensity mixer. Gas samples were removed at the exit of the high intensity mixer, at the medium consistency pulp sampling point and at the top of the tower. Each gas sample was analyzed for residual concentration by gas chromatography. The ozonated pulp for the second run was analyzed for kappa number (CPPA standard, G.18) and ISO brightness (CPPA standard, E.1). The results are shown in Table 4 below.
[0089] The efficiency of delignification was approximately 1 kappa number drop per kg ozone. This observation is comparable to the efficiency observed at medium consistency and demonstrates the successful and efficient use of a high shear mixer with ozone and low consistency pulp.
TABLE 3 Z-stage conditions Conditions First Run Second Run Consistency, % 3.8 3.8 Temperature, ° C. 40 40 pH 2.4 2.4 Ozone charge, % o.d. pulp 0.551 0.566 Ozone concentration, % 12.85 13.21 Pressure 30 90 Residence time, min 6.4 6.4
[0090] [0090] TABLE 4 Results First Run Second Run Results Bottom Top Bottom Top Ozone residual, % on o.d. pulp 0.072 0.001 0.037 0.001 Ozone consumed, % on o.d. pulp 0.479 0.550 0.530 0.565 Kappa 27.0 24.1 Brightness ISO, % 31.4 32.2 Viscosity, CP 25.3 23.3
[0091] Initial kappa: 30.8 and brightness % ISO: 27.9, 39.5 CP
EXAMPLE 4
[0092] The performance of continuously stirred tank reactors (CSTR) of different types was compared to a high shear mixer for delignification efficiency in a D/Z process at low consistency. The performances were compared on the basis of OXE (oxidation equivalent, with 1 OXE=quantity of substance which receives 1 mole electrons when the substance is reduced. ClO 2 =74.12 OXE/Kg and O 3 =125.00 OXE/Kg). All of the CSTRs considered were similar in setup in terms of ozone pressure, concentration and duration.
[0093] The various reactors/mixers run, with the results are as follows.
[0094] CRL: (D/Z)Ep, SKP, initial kappa No. 23.3, final kappa No. 3.6, 14.0 kg ClO 2 ton for 6.3 kg O 3 /ton
[0095] AL: (D/Z)Eop, SKP, initial kappa No. 24.0, final kappa No. 7.9, 8.0 kg ClO 2 /ton, 6.33 kg/O 3 /ton
[0096] ECONOTECH: (D/Z)Ep, SKP, initial kappa No. 23.3, final kappa No. 3.6, 14.0 kg ClO 2 /ton, 6.0 kg O 3 /ton
[0097] CTP: (D/Z)Ep, SKP, initial kappa No. 25.4, final kappa No. 5.1, 15.0 kg ClO 2 /ton, 5.3 kg O 3 /ton
[0098] QUANTUM: (D/Z)Ep, SKP, initial kappa No. 25.5, final kappa No. 4.5, 10.0 kg ClO 2 /ton, 4.0 kg O 3 /ton
[0099] ROBIN: (D/Z)Ep, SKP, initial kappa No. 25.4, final kappa No. 9.0, 9.3 kg ClO 2 /ton, 8.1 kg O 3 /ton
[0100] The delignification efficiency for the various reactors is graphically depicted in FIG. 7. The results clearly demonstrate the superiority of using a high shear mixer in connection with ozone at low consistency, as compared to other reactors which are conventionally used with low consistency pulp.
[0101] While the invention has been described with preferred embodiments, it is to be understood that variations and modifications may be resorted to as will be apparent to those skilled in the art. Such variations and modifications are to be considered within the purview and the scope of the claims appended hereto. | Provided is a process for bleaching pulp with ozone. The process involves preparing a slurry of cellulosic pulp having a consistency in fibers of from 1-5 weight %. Such a low consistency slurry is then mixed with ozone under high shear conditions. The ozone is then maintained in contact with the cellulosic fibers to effect bleaching of the fibers. The present process offers the advantages of bleaching using a low consistency slurry, with the added advantages of employing ozone. | 3 |
This application is the US national phase of international application PCT/SE2004/001797, filed 3 Dec. 2004, which designated the U.S. and claims priority of SE 0303246-3, filed 3 Dec. 2003, the entire contents of each of which are hereby incorporated by reference.
TECHNICAL FIELD
The present invention relates to a method and device for managing batteries of a battery system in a flexible, reliable, and cost effective way and that can be used in a wide variety of applications, such as tools, for example, hand tools, cars, boats, back-up systems, buses, trucks, golf carts, wheel chairs, electric cars and fork-lift trucks. The invention further relates to a computer readable medium comprising instructions for bringing a computer to perform such a method.
BACKGROUND
Series connected battery strings or batteries wired in series are used in a large number of applications and a large number of different vehicles, such as cars, boats, back-up systems, buses, trucks, golf carts, wheel chairs, electric cars and fork-lift trucks. Charging and discharging of such series connected batteries will inevitably result in a variance in voltage between different batteries in the string. If this difference is not corrected it will lead to an undercharging of some batteries and an overcharging of other during the charging of the batteries. This imbalance entails sulphating for lead-acid batteries (caused by undercharging) and drying up (caused by overcharging), which, in turn, will lead to that the charging level of the batteries will be below 100%, i.e. the batteries are not completely charged, and to a shortened duration of the batteries or even to battery damage. The charge process is also slowed down when the battery is reaching 100% state of charge due to apparent high voltage of the battery. The voltage difference which forces energy from the charge device to the battery is therefore reduced.
In order to avoid or prevent this voltage variance or imbalance between the batteries, a number of solutions have been proposed. A common approach is equalization, which is a technique that reduces the imbalances between the batteries aiming at equalizing the voltages of the different batteries of the string. Normally, an extended charging at a cyclic voltage or a low constant charging current is applied during an extended period of time at amplified voltages, thereby power from a battery with a higher voltage is shuffled to a battery with a lower voltage until they have an approximately equal voltage.
Another frequently utilized approach is to use a so called booster, which apply a voltage boost. This device increases the voltage to such a level that the charging is more efficient. It could however not handle the difference between different batteries in a string. Such a device is expensive if it is arranged to handle higher currents than approximately 8-12 A. In many applications, for example, buses, trucks, or fork-lift trucks current of approximately 100 A or more is common.
A third approach is to use a multi-stage generator in the engine. This type of generator could provide a controlled charge algorithm, but they are rather expensive. Furthermore, under certain conditions, it is preferred that the temperature at the battery is known in order to be able to apply a suitable charging current thus an additional temperature sensor must be located at the batteries and the temperature data must be transferred from the batteries to the generator. In many applications the temperature difference between the temperature at the batteries and the temperature at the generator can be forty degrees ° C. or more. Taken together this entails a complex construction and high costs as well as it may induce sensing errors.
Thus it is difficult to find a method and a device that provides a flexible, and reliable handling of the batteries of a battery string at a low cost and that can be used in a wide variety of applications, such as buses, trucks, golf carts, wheel chairs, electric cars and fork-lift trucks, etc.
SUMMMARY
An object is to provide a method and device for managing batteries of a battery system in a flexible, reliable, and cost effective way and that can be used in a wide variety of applications, such as tools, for example, hand tools, cars, boats, back-up systems, buses, trucks, golf carts, wheel chairs, electric cars and fork-lift trucks, etc.
The term battery refers to one cell or several cells connected in series.
According to a first aspect of the technology, there is provided a method for managing a battery system including a number of batteries. The method comprises the steps of detecting the battery voltage in the batteries of the battery system and utilizing a voltage imbalance between different batteries of the system during operation of the battery system.
According to a second aspect of the technology, there is provided a device for managing a battery system including a number of serially-coupled batteries. The device comprises a voltage detector connected to said battery system and arranged to detect the battery voltage the batteries of the battery system; a DC-to-DC-converter connected to said battery system; and a controller connected to said voltage detector and to said DC-to-DC-converter and being arranged to control the voltage distribution over the batteries of the battery system via said DC-to-DC-converter.
According to another aspect, there is provided a computer readable medium comprising instructions for bringing a computer to perform the method according to the first aspect.
The technology is based on the idea of utilizing a voltage variance or imbalance between batteries of battery system including a number of serially connected batteries for the management of the system. The technology provides a high degree of flexibility, and can be used in large number of applications, such as tools, for example, hand tools, in vehicles such as buses, trucks, golf carts, wheel chairs, electric cars and fork-lift trucks, etc., without requiring any major modifications. The technology can also be used in a wide variety of different types of batteries, for example, lead-acid batteries NiCd batteries, LiIon batteries, or NiMH batteries. Moreover, it can handle a very broad spectrum of currents. The design is simple and can therefore be realised in a cost effective manner.
According to a preferred example embodiment, a voltage imbalance between different batteries of the battery system is created and utilized during the operation of the battery system. This can be useful in certain operations, for example, during the charging of the batteries of the battery system. Thereby, the charging can be performed significantly faster since the charging is performed at a higher voltage, i.e. using the voltage difference. In another example embodiment, a detected voltage imbalance between the different batteries of the system is enhanced. This can also be useful, for example, during the charging of the batteries of the battery system in order to speed up the charging of the batteries.
According to a preferred example embodiment, a switching or alternating between batteries of the battery system having different voltages during predetermined intervals is performed during the operation of the batteries.
Furthermore, technology is also flexible in that it can use a voltage imbalance, created deliberately or detected, to improve the function of the battery system and the vehicle in which the system is mounted in dependence of external or environmental conditions. Accordingly, the technology can adapt the operation or functioning of the battery system to the conditions present.
According to an example embodiment, the device includes a temperature sensor the sense the temperature at the batteries of the battery system, thereby the operation or functioning of the battery system and the vehicle can be adapted to the external temperature. This is of a great benefit under warm as well as cold conditions and, in particular, in area where the temperature can vary to large extent. The device can also be used to provide other voltages from a battery. For example, 12V can be obtained from a 24V battery.
As realized by the person skilled in the art, the method as well as preferred example embodiments, are suitable to realize as a computer program or a computer readable medium.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows schematically a battery system managing device of a first example embodiment connected to a generator of a vehicle and to a battery system of two serially connected batteries;
FIG. 2 shows schematically the battery system managing device of FIG. 1 in more detail;
FIG. 3 shows schematically an embodiment of a method for battery system management;
FIG. 4 shows schematically a battery system managing device of a another example embodiment connected to a generator of a vehicle and to a battery system of six serially-connected batteries;
FIG. 5 shows schematically the battery system managing device of FIG. 4 in more detail; and
FIG. 6 shows schematically the principles of the method of a first example embodiment.
DETAILED DESCRIPTION
With reference first to FIG. 1 , a battery system managing device of a first example embodiment connected to a generator, alternator or other type of charging device and to a battery system of two serially connected batteries will be shown schematically. A battery system management device 10 is connected to a generator 12 of a vehicle (not shown), such as a bus, a truck, a golf cart, a wheel chair, an electric car, or a fork-lift truck, and over the batteries 14 , 14 a respectively, of the battery system string 16 . In this embodiment, the generator is of 28V and the voltage of the batteries 14 , 14 a are of 14V each. The open circuit voltage over each battery is typically lower than 14V. As discussed above, the charging and discharging of such series connected batteries results, in conventional applications, in slow charging when the batteries are close to 100% state of charge and/or a voltage imbalance between the batteries. Thus, the actual voltages over the batteries 14 , 14 a may drift so that the voltage over the first battery 14 could be 14.5V or higher and the voltage over the second battery is 13.5V or lower, or vice versa.
Turning now to FIG. 2 , the battery system managing device of FIG. 1 will be shown in more detail. The battery system managing device 10 comprises a DC-to-DC-converter 20 , a controller 21 , a sensing or detecting device 23 for sensing or detecting a battery parameter, and a timer unit 24 . In this embodiment, the sensing device 23 is a temperature sensor for sensing the temperature at the batteries. In certain applications, this sensor is not built-in in the battery managing device 10 , but placed at a distance from the device itself and wired to the device. In other applications a number of sensors are used in order to sense more than one parameter. For example, a sensor can be arranged to sense the battery type or the charge level of a battery.
A voltage detector 28 is further connected to the controller 21 and to the batteries 14 , 14 a to detect the voltage over respective battery 14 , 14 a . According to other embodiments, the voltage detector 28 can be incorporated in the DC-to-DC-converter 20 . Moreover, a power supply (not shown) is included to power the components of the managing device 10 , for example, the controller 21 and the DC-to-DC-converter 20 . However, according to an alternative, the device can be powered by the main supply.
The controller 21 is connected to the DC-to-DC-converter 20 , the sensing device 23 , and the timer unit 24 , and arranged to control the output of the DC-to-DC-converter 20 . The DC-to-DC-converter 20 is connected to the input 25 of the first battery 14 , to the output 25 a of the first battery 14 , the input 26 of the second battery 14 a , and the output 26 a of the second battery 14 a . According to this example embodiment, each of the batteries 14 , 14 a is a 14V battery and the generator is of 28V. Due to the voltage drift of the batteries discussed above, the voltage over the first battery 14 can be approximately 14.5V and the voltage over the second battery 14 a can be about 13.5V. The input voltage of the of the DC-to-DC-converter 20 is approximately 28V. Using a conventional equalizer instead of the battery system management device 10 , the voltages over the two batteries would have been leveled out, i.e. the voltage over the batteries is about 14V each. In contrast to this, the battery system management device 10 utilizes the voltage imbalance between the batteries in order to, for example, charge at a higher voltage or supply the generator with a higher voltage. Accordingly, the higher voltage of 14.5V of the first battery 14 is utilized. According to one embodiment, see FIG. 3 , a switching between the batteries 14 , 14 a occurs at predetermined intervals, i.e., during a first predetermined period of time t 1 the higher voltage V 1 of the first battery 14 is applied, which in this embodiment is about 14.5V, and during a second period of time the lower voltage V 2 of the second battery 14 a is applied, which in this embodiment is about 13.5V. This may, for example, be performed during charging, discharging, or when the batteries are in an idle state. This alternating process is preferably maintained until the batteries are equal in state of charge and, if possible, fully charged. The intervals may have a length of a few seconds to a magnitude of several minutes, for example, 10-20 minutes. According to this embodiment the DC-to-DC-converter 20 is arranged to, when receiving instructions from the controller 21 , for example, change the potential of the connection 29 between the batteries 14 , 14 a upwards or downwards. As the skilled man realizes there are other ways of obtaining these functions, for example, by switching means.
According to a practical example, if a 12V battery is charged with 14V and thereafter is disconnected, the voltage over the battery is about 13.8V the first few seconds. This falls to about 13V after a period of time (5-120 minutes). Accordingly, at charging using the present technology, in a battery system with a charging voltage of 28V and two batteries of 12V each, the imbalance between the batteries can be enhanced so that the first battery 14 has a voltage of 13.3V and the voltage over the second battery 14 a has a voltage of 14.7V. Thereby, the battery 14 having a voltage of 13.3V falls rapidly to 13.3V but this is performed without any significant transfer of energy and thereafter the battery is maintained at this level. Over the second battery 14 a , the current driving voltage is now 14.7-13.8V =0.9V, i.e. almost a fivefold increase. The charging of the battery is increased at least four times. If alternation between the batteries is performed on a regular basis, typically with 5 seconds to 10 minutes intervals, the increase is halved, but in total the charging speed is at least doubled.
Under certain conditions it may also be described to increase the voltage difference between the batteries, for example, at cold weather conditions which is of frequent occurrence, for example, in Scandinavia. To elaborate, according to the example embodiment shown in FIGS. 1 and 2 , if the controller 21 is notified via the temperature sensor 23 that the temperature at the batteries, or outside the vehicle, depending on the placement of the sensor 23 , is low, for example, under a predetermined level, which indicates that a higher voltage is desirable. The gas voltage of a battery rises with a decreasing temperature and it is favorable to charge at or near the gas voltage. Thereafter, the controller 21 sends an instruction to the DC-to-DC-converter 20 to control the voltage over the first battery 14 to be higher than the actual voltage of about 14.5V, for example, 15.0V.
With reference now to FIGS. 4 and 5 , another example embodiment of a battery system managing device schematically shown. This embodiment is adapted to be used with a battery system of six serially connected batteries. A battery system management device 40 is connected to a generator 42 , alternator or other type of charging device, and to the batteries 44 , 44 a , 44 b 44 c 44 d , and 44 e , respectively, of the battery system or battery string 46 of the vehicle. In this embodiment, the generator is of 36V and the batteries 44 , 44 a , 44 b 44 c 44 d , and 44 e , are accordingly of 6V each. As discussed above, the charging and discharging of such series connected batteries results in a voltage imbalance between the batteries. Thus, the actual voltages over the batteries 14 , 14 a may, for example, drift so that the voltage over the first battery 44 is about 6.5V, the voltage over the second battery 44 a is about 6.3V, the voltage over the third battery 44 b is about 6.1V, the voltage over the fourth battery 44 c is about 5.9V, the voltage over the fifth battery 44 d is about 5.7V, and the voltage over the sixth battery 44 e is about 5.5V.
Turning now to FIG. 5 , the battery system managing device of FIG. 4 will be shown in more detail. The battery system managing device 40 comprises a first DC-to-DC-converter 50 , a second DC-to-DC-converter 50 a , a third DC-to-DC-converter 50 b , a fourth DC-to-DC-converter 50 c , and a fifth DC-to-DC-converter 50 d , a controller 51 , a sensing or detecting device for sensing or detecting a battery parameter 53 , and a timer unit 54 . A voltage detector, which in this embodiment is incorporated in respective DC-to-DC-converter 50 - 50 d , is further connected to the controller 51 and to the batteries 44 - 44 e and are arranged to detect the voltage over respective battery 44 - 44 e . As described above, the voltage detector can be arranged stand-alone from the DC-to-DC-converters 50 - 50 d as in the embodiment shown in FIG. 2 indicated with reference numeral 28 . Moreover, a power supply (not shown) is included in the device 40 to power the components of the managing device 40 , for example, the controller 51 and the DC-to-DC-converters 50 - 50 d . However, in other embodiments the device is powered by the main supply. In this embodiment, the sensing device 53 is a temperature sensor 53 for sensing the temperature at the battery. In certain application, this sensor is not built-in in the battery managing device 10 , but placed at a distance from the device itself and wired to the device. In other applications a number of sensors are used in order to sense more than one parameter. In one example, one temperature sensor is provided for each battery. The controller 51 is connected to each one of the DC-to-DC-converters 50 - 50 d , and the timer unit 54 , and arranged to control the output of the DC-to-DC-converters 50 - 50 d . The first DC-to-DC-converter 50 is connected to the first battery 44 and the second battery 44 a , the second DC-to-DC-converter 50 a is connected to the second battery 44 a and the third battery 44 b , the third DC-to-DC-converter 50 b is connected to the third battery 44 b and the fourth battery 44 c , the fourth DC-to-DC-converter 50 c is connected to the fourth battery 44 c and the fifth battery 44 d , and the fifth DC-to-DC-converter 50 d is connected to the fifth battery 44 d and the sixth battery 44 e.
The operation principles of the device 50 mainly corresponds to the operation of the device described with reference to FIGS. 1 and 2 for that reason it is not repeated.
According to another example embodiment, three batteries are connected in series and the device comprises two DC-to-DC-converters. In this case, each battery has a voltage of 14V and the total generator voltage is 42V. The voltage over the first battery can be placed at 14.5V, the voltage over the second at 13, and the voltage over the third at 14.5V. After, for example, 5 minutes this distribution can be changed so that voltage over the first battery is at 14.5V, the voltage over the second is 14.5V, and the voltage over the third is 13.5V.
Referring now to FIG. 6 , principles of the method will be described. First, at step 60 , a battery voltage over the batteries of the battery system is detected, for example, at the batteries 44 - 44 e shown in FIG. 5 . At step 62 , which is a optional step, a battery parameter of the battery system is sensed, for example, the temperature. The sensed battery parameter can be used for the control of the voltage distribution of the batteries of the battery system. Then, at step 64 , a voltage imbalance between different batteries of the battery system during operation of the battery system is utilized, as described above. According to an embodiment, the voltage distribution of the batteries is controlled in order to create a voltage imbalance between different batteries of the battery system. For example, a detected voltage imbalance between the different batteries of the system can be enhanced and/or alternated between batteries of the battery system having different voltages during predetermined intervals as described earlier. In a preferred embodiment, the voltage imbalance between different batteries of the system is utilized during the charging and/or discharging of the batteries.
Although specific embodiments have been shown and described herein for purposes of illustration and exemplification, it is understood by those of ordinary skill in the art that the specific embodiments shown and described may be substituted for a wide variety of alternative and/or equivalent. Those of ordinary skill in the art will readily appreciate that the technology could be implemented in a wide variety of embodiments, including hardware and software implementations, or combinations thereof. As an example, many of the functions described above may be obtained and carried out by suitable software comprised in a micro-chip or the like data carrier. This application is intended to cover any adaptations or variations of the preferred embodiments discussed herein. Consequently, the present invention is defined by the wording of the appended claims and equivalents thereof. | Method for managing a battery system including a number of serially coupled batteries in a flexible, reliable, and cost effective way and that can be used in a wide variety of applications, such as tools, for example, hand tools, cars, boats, back-up systems, buses, trucks, golf carts, wheel chairs, electric cars and fork-lift trucks. The method includes the steps of detecting the battery voltage over each individual battery of the battery system; and utilizing a voltage imbalance between different batteries of the system during operation of the battery system. Furthermore, the method controls the voltage distribution of the batteries to create a voltage imbalance between different batteries of the battery system. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 793,274, filed Oct. 1, 1985, abandoned.
BACKGROUND OF THE INVENTION
In the past ten years, there has been a surge in the development of materials suitable for withstanding high temperatures, particularly those that are encountered in space reentry vehicles, rocket nozzles, turbines, internal combustion engines and the like. Materials used for such applications should exhibit high-temperature strength and resistance to thermal shock, as well as the ability to resist abrasion. Two key properties that must be displayed by such materials are (1) resistance to chemical degradation, particularly oxidation and/or reduction at such temperatures, and (2) sufficient thermal conductivity to diffuse thermal stress. Materials that have considerable potential for high-temperature applications are ceramic or metal matrix composites. To date, however, neither type of composite has been developed with significant mechanical strength at temperatures much above 1200° C.-1400° C.
Considerable effort is presently being expended to extend the useful range of ceramic or metal matrix composites. One approach has been to reinforce composites with fibrous material. Light-weight carbonaceous fibers are particularly attractive because they can be fabricated in a wide variety of tensile strengths and moduli of elasticity. Moreover, the thermal conductivity of these fibers is eight times that of copper and the fibers also exhibit a slightly negative coefficient of thermal expansion.
While carbonaceous fibers composed of carbon, carbides, or graphite have proven to increase the useful mechanical properties of resin matrix composites and some metal matrix composites, they nevertheless do not confer stability much beyond 1500° C. In part, this is because the matrices of such composites readily degrade carbonaceous fibers during composite fabricating. Fabrication must often be performed at significantly higher temperatures than those compatible with the otherwise useful carbonaceous fibers. Thus carbonaceous fibers are of limited use in high-temperature applications because of the tendency of these fibers to deteriorate. For instance, graphite fibers can withstand temperatures approaching 2200° C. in vacuum but oxidize readily in the air above 316° C. and unprotected graphite fibers at temperatures above 1350° C.-1500° C. in a SiAlON matrix are readily destroyed during composite fabrication.
Attempts to prevent oxidation of carbonaceous fibers have met with limited success. One approach has been to coat carbon fibers with silicon carbide, which in turn provides a secondary layer of silicon dioxide as a shield over the silicon carbide primary coating. This procedure works well at temperatures below 1200° C. Above this temperature, however, silicon dioxide undergoes a phase change and there is a loss of protection for the underlying carbonaceous fiber.
As noted above, carbonaceous fibers display superior thermal conductivity properties. Ceramics reinforced with carbonaceous fibers enjoy improved resistance to thermomechanical shock because the fibers conduct heat away from the site of impact. However, at high temperatures carbonaceous fibers are oxidized or reduced, and consequently fiber reinforced ceramic composites in which they are incorporated undergo premature catastrophic failure. Thus, in order to take further advantage of carbonaceous fibers in fabricating fiber reinforced ceramic or metal matrix composites, it is desirable that methods of shielding the fibers from chemical degradation at high temperatures be developed.
U.S. Pat. No. 4,376,803 describes a method for coating carbon fibers that can be used in metal matrix composites. The coated carbon fibers are not useful at high temperatures because they are (1) coated with metal oxides having low melting temperatures, such as oxides of silicon, titanium, vanadium, lithium, sodium, potassium, zirconium or boron or (2) coated with a high melting temperature oxide such as magnesium oxide that is applied by a method that forms a porous oxide coating about the fibers. Fibers produced by the latter method are not suitable for high temperature applications because oxygen diffuses through the pores resulting in oxidation of the fibers.
Considering the enhanced properties that ceramic or metal composite matrices reinforced with carbonaceous fibers display, it is particularly desirable to develop a process for protecting such fibers so that they are resistant to chemical destruction at high temperatures.
SUMMARY OF THE INVENTION
In its broadest form, the invention herein comprises a non-porous metal oxide coating capable of withstanding degradation at temperatures above 1600° C. which facilitates using carbonaceous fibers in ceramic or metal matrices. In order to prevent the oxidation of carbonaceous fibers and, additionally, enhance the structurally interactive properties of the fibers with composite matrices at high temperatures, the fibers are coated using techniques that yield a non-porous layer of a suitable metal oxide having a thickness of at least about 250 angstroms and which is stable in surface-to-surface contact with carbonaceous compounds at temperatures greater than 1600° C.
A variety of metal oxides have the requisite high temperature stability, and these include oxides of metals from Groups IIA, IIIA, IIIB and IVB of the Periodic Table. The metal oxides can be used to coat carbonaceous fibers of carbon, graphite, or carbide. The coated fibers may be employed in composites with ceramic or metal matrices composed of a number of materials. Examples of materials suitable for ceramic matrices include oxides, borides, carbides, carboxides, nitrides, oxynitrides or carbonitrides, while metal matrices can be composed of iron, cobalt, nickel, vanadium and other metals having similar properties.
Furthermore, metal oxide-coated carbonaceous fibers can, if required by the application envisioned for the fibers, be secondarily coated with a surface-active metal or dopant that enhances the wetting characteristics of the fiber and increases the interfacial bonding of the fibers with the matrix materials.
DETAILED DESCRIPTION OF THE INVENTION
The subject invention comprises non-porous metal oxide-coated carbonaceous fibers exhibiting several advantages over carbonaceous fibers shielded by other means: first, the fibers are practically impervious to oxidizing or reducing radicals at temperatures up to 2300° C.; second, they do not diffuse into the matrix or the fiber at high temperature; and third, they provide a surface capable of intermediate interfacial bonding with matrix materials resulting in good composite translational strength.
Carbonaceous fibers composed primarily of carbon, graphite, or a carbide can be coated with a multiplicity of metal oxides. An example of a suitable carbide is silicon carbide, which can be obtained commercially as either multifiber or monofiber material. In addition to silicon carbide, a variety of other carbonaceous fibers can be utilized. For example, one can use boron carbide as described in U.S. Pat. Nos. 3,398,013 and 3,294,880, and French Patent No. 1,511,672; transition element carbides as described in U.S. Pat. Nos. 3,269,802 and 3,433,725; or carbonitride fibers as described in U.S. Pat. No. 4,097,294. Other carbides which can be used include the carbides of tungsten, niobium, tantalum, uranium, zirconium, hafnium, titanium, beryllium and vanadium.
A number of metal oxides are suitable for forming a non-porous high temperature shield about a carbonaceous fiber. Particularly useful metal oxides are MgO and BeO, as well as a number of oxides of metals of Groups II, IIIA, IIIB (other than oxides of actinides other than Thorium) and IVB of the Periodic Table. An example of a preferred metal oxide is yttria, which is particularly favored for its hightemperature stability. Thus, the following elements are among those suitable for forming metal oxide shields: Be and Mg (Group IIA); Al (Group IIIA); Sc, Y, La, the lanthanides and Th (Group IIIB); and Zr and Hf (Group IVB).
It is anticipated that the minimum effective metal oxide coating thickness will be about 250 angstroms, but thicker coatings of up to 1000 angstroms or more will be preferred for use in particular instances. An example would be in the fabrication of pressed fiber composites or, alternatively, when the fabrication process itself dictates that the coating be significantly greater than the minimum effective thickness. The 250 angstrom minimum effective coating thickness is obtainable by manufacturing techniques well-known to those in the art. Care should be taken to insure that the coating is continuous (non-porous) over the fiber.
While carbonaceous fibers can be coated with a wide variety of metal oxides to form a chemical shield capable of preventing oxidation and/or reduction of the fibers, several factors will be determinative of the choice of metal oxide. Cost will be a consideration as the expense of different metal oxides differs widely. Another factor will be the interfacial bond lives between fiber and coating and between coating and matrix at expected service temperatures. Also important will be other properties such as toxicity. For example, MgO is inexpensive and is stable in the presence of carbon at temperatures up to 1800° C., while BeO is expensive and toxic but stable at higher temperatures, up to about 2300° C. The Group IIIB metal oxide, thorium oxide, is similarly expensive and stable at temperatures of about 2000° C., but radioactive. Thus, in those instances where metal oxide-coated carbonaceous fibers are sought to be employed in ceramic or metal matrices for applications at temperatures about 1800° C. where cost is not a factor, BeO or thorium oxide might be preferred; whereas at temperatures below 1800° C., the more economical MgO would be favored.
Several well-known techniques can be utilized for coating carbonaceous fibers. For at least two reasons the preferred technique is chemical vapor deposition. First, this process can be carried out at temperatures that minimize heat dependent reactions between metal oxide coating precursors and the carbonaceous fibers. Second, chemical vapor deposition deposits a metal oxide coating, that is non-porous (continuous) about the carbonaceous fiber. The latter is necessary for the fibers to withstand the high temperature applications for which they are intended. The non-porous nature of the deposited metal oxide layer prevents oxygen from diffusing into, contacting and oxidizing the underlying fibers. Suitable chemical vapor deposition techniques are described by Bunshah in Deposition Technologies for Films and Coatings (Knowles Publications, N.J. 1982).
Alternatively, fibers can be coated by first dissolving the metal oxide in a colloidal suspension wherein the suspension consists of a volatile solution that is contacted with the carbonaceous fiber. Subsequently the solution is volatilized leaving the metal oxide in place on the carbonaceous fiber. The metal oxide is then sintered to eliminate porosity. Another procedure that may be preferred in certain instances is to coat the carbonaceous fibers with metal directly and form the metal oxide by subsequent exposure to an oxidizing environment that forms the metal oxide but does not oxidize the underlying fiber. This procedure is described in U.S. Pat. No. 3,736,109, particularly as applied to forming a coating of MgO by oxidation of magnasium metal. Regardless of the procedure used, it is important to control the temperature so as not to oxidize the fiber prior to or during application of the metal oxide coating.
It will be appreciated that not all methods of coating carbonaceous fibers will form a non-porous layer of metal oxide about the fibers absent additional processing steps. This is particularly true where the metal oxide is applied in the form of a gel or colloid. In these instances, the metal oxide should be sintered at temperatures of about 1400°-1600° C. which has the effect of eliminating pores present in the oxide layer.
MgO has been shown in U.S. Pat. No. 4,376,803, to be suitable for coating carbonaceous fibers having low temperature applications. I have discovered that MgO is suitable for coating carbonaceous fibers having high temperature applications provided that the MgO is sintered at high temperatures, particularly between 1400° C. and 1700° C.
The metal-oxide coated carbonaceous fibers can be employed in ceramic matrices consisting of materials that are well-known to those skilled in the art and that are commonly used for fabricating monolithic ceramics. Particularly useful are the following materials: BeO, Al 2 O 3 , Y 2 O 3 , LiAlSi 2 O 6 , SiAlON, Al 6 Si 2 O 13 , ZrSiO 4 , SiC, Si 3 N 4 , transformation-toughened ZrO 2 , partially-stabilized ZrO 2 , transformation-toughened Al 2 O 3 , Si 3 N-SiO 2 -Y 2 O 3 , ThO 2 , TiB 2 , ZrB 2 , HfB 2 , AlON, AlN, B 4 C, BN, MgAl 2 O 4 , TiC, Cr 3 C 2 , TiN, cordierite, Fe 2 O 3 and Fe 3 O 4 . Generally, metal oxide coated carbonaceous fibers will make up to 55% by volume of the composite, though pressed fiber composites may benefit by having higher fiber amounts.
In addition to use in ceramic matrices, the coated carbonaceous fibers can similarly be employed in metal matrices. A variety of metals are compatible for combination with metal oxide-coated carbonaceous fibers and these include iron, cobalt, nickel, vanadium, beryllium, titanium, silver, gold, yttrium, niobium, tantalum, rhenium, chromium, molybdenum and tungsten, as well as alloys of these materials.
A variety of methods can be used to combine the metaloxide coated carbonaceous fibers with the matrix material. One method is by hot-pressing a mixture of carbonaceous fibers with matrix components. This procedure is described in U.S. Pat. No. 4,314,852.
Another method is by pressureless sintering in a controlled atmosphere or under vacuum. Still another method is chemical vapor infiltration (CVI) in which coated fiber architecture is infiltrated with gaseous compounds that react at elevated temperature to produce the matrix.
The following examples will illustrate the invention.
EXAMPLE I
MgO-coated Carbon Fiber Reinforced Alumina Ceramic Composite
A layer of MgO more than 250 angstroms thick but less than 1000 angstroms thick is deposited on Amoco Performance Products P55 2K carbon fibers by chemical vapor deposition (CVD). The carbon fibers have 2.5×10 5 psi (1.7×10 6 kPA) tensile strength and 5.5×10 7 psi (3.8×10 8 kPa) tensile modulus. The MgO fiber coating is not porous and covers the entire surface area of each filament because coating is precipitated from a vapor that surrounds the fibers. Substrate temperature and vapor phase densification aids control adhesion of the coating to the carbon fiber. A fiber-reinforced ceramic composite containing up to 55 volume percent coated carbon fibers in an alpha-alumina matrix can be fabricated by hot pressing, pressureless sintering, chemical vapor infiltration, and other well known methods. Hot-pressing a sample with 40 volume percent fibers at up to 1650° C. under 2000 psi (13800 kPa) pressure produces near theoretical density with a unidirectional composite translation strength of 9.1×10 4 psi (6.3×10 5 kPa) at room temperature. The density of the composite is 3.098 g/cm 3 .
EXAMPLE II
BeO-coated Silicon Carbonitride Fiber Reinforced Silicon Carbonitride Ceramic Composite
Silicon carbonitride fibers made by the process of U.S. Pat. No. 4,097,294 in an ammonia atmosphere can be coated with BeO by CVD to impart oxidation resistance and to prevent diffusion into a silicon carbonitride matrix. Fibers are fabricated under tension to control molecular orientation. Highly ordered structure makes fibers of a given material stronger and higher in modulus than monolithic materials. Composite behavior is possible, because the silicon carbonitride fibers are slightly higher in modulus than the silicon carbonitride matrix. Coefficient of thermal expansion mismatch is impossible. Fiber reinforcement of a ceramic matrix of the same chemical content as the fiber (but different crystalline structure) enables selective static properties by means of fiber architecture. Hot pressing or pressureless sintering the composite using densification aids while holding fibers under tension at lower temperature than the critical temperature for the fiber prevents strong bonding between the BeO fiber coating and the silicon carbonitride matrix.
EXAMPLE III
MgO-coated Carbon Fiber Reinforced Iron
MgO is deposited on Amoco Performance Products T40 12K carbon fiber by chemical vapor deposition. The carbon fiber has 8.2×10 5 psi (5.6×10 6 kPa) tensile strength and 4.2×10 7 psi (2.9×10 8 kPa) tensile modulus. Fibers are preheated to 1000°-1300° C. in an evacuated pre-form before casting in an iron matrix. Sizing applied to the coated fibers encourages the molten iron matrix to wet the fiber reinforcement. A composite with 25% volume fraction of fibers has a 1.8×10 5 psi (1.2×10 6 kPa) unidirectional composite tensile strength and a 5.94 g/cm 3 composite density. The composite has 0.210 (km/s) 2 specific strength compared to 0.054 (km/s) 2 for cast iron.
EXAMPLE IV
ThO 2 -coated Carbon Fiber reinforced W-l ThO 2
Chemical vapor deposition is used to coat carbon fibers such as Amoco Performance Products P75S-2K with ThO 2 . Thoria is stable in surface-to-surface contact with carbon up to 2000° C. and is also stable is surface-to-surface contact with tungsten up to 2000° C. Tungsten is infiltrated among fibers held in tension and sintered using pressure assured densification at 1500°-1600° C. The resulting composite of 50% volume fraction carbon fibers with 2 g/cm 3 density in a tungsten matrix with 19.3 g/cm 3 density has a composite density of 10.65 g/cm 3 . Carbon fiber reinforced tungsten MMC retains greater strength at temperatures approaching 2000° C. than monolithic tungsten because the carbon fibers retain almost all room temperature strength at 2000° C. | Non-porous metal oxide-coated carbonaceous fibers capable of withstanding chemical degradation at temperatures above 1600° C. and that are particularly useful in the construction of ceramic or metal composites without carbon-carbide hypereutectic formation or micro-cracking in metal and ceramic matrix composites, respectively, but with good interfacial bonding, thereby allowing the same to be favorably employed in space reentry vehicles, heat shields, high-performance aircraft, internal combustion engines, and the like. | 3 |
RELATED APPLICATION
This application is related to copending U.S. application Ser. No. 09/325,683, entitled “METHOD AND SYSTEM FOR MANAGING MULTIPLE MANAGEMENT PROTOCOLS IN A NETWORK ELEMENT.”
TECHNICAL FIELD OF THE INVENTION
This invention relates generally to telecommunications systems, and more particularly to a common management information base (MIB) for a network element in a telecommunications system.
BACKGROUND OF THE INVENTION
Telecommunications systems include customer premise equipment (CPE), local loops connecting each customer premise to a central office (CO) or other node, nodes providing switching and signaling for the system, and internode trunks connecting the various nodes. The customer premise equipment (CPE) includes telephones, modems for communicating data over phone lines, computer and other devices that can directly communicate video, audio, and other data over a datalink. The network nodes include tradition circuit-switch nodes, which have transmission pass dedicated to specific users for the duration of a call and employ continuous, fixed-bandwidth transmission as well as packet-switch nodes that allow dynamic bandwidth, dependent on the application. The transmission media between the nodes may be wireline, wireless, or a combination of these or other transmission medias.
In a telecommunication system, the nodes are managed by standardized management protocols such as Transaction Language One (TL-1), simple network management protocol (SNMP), Common Management Information Service Element (CMISE), and the like. Generally speaking, each of these management protocols includes a protocol agent and object model. The agent is responsible for parsing the external management commands and maintaining communication sessions with external management stations or users. The object model is a management information base (MIB). The MIB is a data structure built for a specific management protocol to exchange the management information between a node and external management stations.
Multiple protocol nodes that handle disparate types of traffic are typically required to support multiple management protocols such as TL-1, SNMP, and/or CMISE. Provision of multiple databases to support the different protocols requires large amounts of resources to implement the databases and maintain data integrity across the databases. One attempt to use a single database for multiple protocols configured the database in accordance with one protocol and used a protocol adapter for a second protocol. The protocol adapter translates protocol messages from the second protocol to the first protocol and responses back to the second protocol. Due to the incompatibility between management protocols, however, the adapter is a complex component that is expensive to implement. In addition, the adapter is inefficient due to the protocol translations, which slow down response time. Other attempts to support multiple management protocols with a single database provided only limited functionality for one of the protocols while creating special commands for the other. This solution is expensive to implement and provides only a partial solution.
SUMMARY OF THE INVENTION
The present invention provides a common management information base (MIB) that substantially eliminates or reduces problems associated with previous methods and systems. In particular, the common MIB provides a layer of abstraction to isolate internal data representations from data representations made externally to a network element. This allows a network element to have a single, consistent internal representation of data, and at the same time, support multiple different external interfaces for management.
In accordance with one embodiment of the present invention, the common MIB or other data store includes a set of data structures, a set of entity classes, and an interface object. The data structures each store data for an entity type. The entity classes each include specific functionality for an entity type. The interface object includes base functionality for the entity types. An interface is operable to generate an entity interface by loading the interface object with an entity class for an entity type and to access the data structure for the entity type using the entity interface.
More specifically, in accordance with a particular embodiment of the present invention, the data structures are stored in non-volatile memory, such as relational database tables. In this and other embodiments, the interface accesses the data structures by executing the entity interface. The entity interface is initially populated, executed, and responded to by executing function calls within the entity interface.
Technical advantages of the present invention include providing a protocol independent MIB for managing multi-protocol network elements within a telecommunications network. In particular, the common MIB provides a layer of abstraction to isolate data representations internal to the network element from data representations made externally to the network element. Moreover, the modular design of the common MIB allows for time and cost efficient testing, integration and packaging of the system.
Another technical advantage of the present invention includes providing an improved data store for storing data representations of a network element. In particular, the MIB includes a collection of managed entities (MEs) that includes a class definition and data attributes stored in non-volatile memory. The class definitions are instantiated to generate an interface for communicating with the data attributes in the non-volatile memory. In this way, a separate instance need not be continuously maintained for each ME. Therefore use of resources is optimized.
Other technical advantages of the present invention will be readily apparent to one skilled in the art from the following figures, description, and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals represent like parts, in which:
FIG. 1 is a block diagram illustrating a common management information base (MIB) in accordance with one embodiment of the present invention;
FIG. 2 is a block diagram illustrating relationships between interface, base and managed entities (ME) classes in the common MIB of FIG. 1 in accordance with one embodiment of the present invention;
FIG. 3 is a block diagram illustrating the ME command object of FIG. 1 in accordance with one embodiment of the present invention; and
FIG. 4 is a flow diagram illustrating a method for performing a management transaction with the common MIB of FIG. 1 in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates management components of a multi-protocol network element (NE) 10 in accordance with one embodiment of the present invention. In this embodiment, the NE 10 includes Internet Protocol (IP), Asynchronous Transfer Mode (ATM), and Synchronous Optical Network (SONET) layers and functionality and can communicate over local area networks (LANs) as well as transmission line trunks. IP and other suitable traffic from the LAN is converted to ATM traffic for transmission by the SONET layer which forms the physical interface for the transmission line trunks.
The NE 10 supports Common Management Information Service Element (CMISE), simple network management protocol (SNMP), and Transaction Language One (TL-1) management protocols. A CMISE management station 14 , SNMP management station 16 , and TL-1 management station 18 are coupled to the NE 10 by a local area network (LAN), wide area network (WAN), or other communication link 20 . Accordingly, the management stations 14 , 16 , and 18 may be local or remote from the NE 10 .
Referring to FIG. 1, the NE 10 includes a plurality of protocol-specific subsystems 30 , a common management information base (MIB) 32 , and a set of low level software drivers 34 . Each subsystem 30 includes a protocol-specific agent 40 and a data model 42 . The protocol-specific agent 40 parses external management commands and maintains communication sessions with external management stations or users. The data model 42 maps protocol-specific management transactions received from a management station to a common management protocol for processing by the common MIB 32 . Accordingly, all protocol-specific processing is local to the subsystems 30 , allowing the common MIB 32 to be protocol independent.
For the embodiment of FIG. 1, the subsystems 30 include a CMISE subsystem 50 for supporting the CMISE management station 14 , a SNMP subsystem 52 for supporting the SNMP subsystem 16 , and a TL-1 subsystem 54 for supporting the TL-1 management station 18 . The CMISE protocol is an OSI defined management service containing an interface with a user, specifying the service provided, and a protocol, specifying the protocol data unit format and the associated procedures. In the CMISE subsystem 50 , the data model 42 is a Guideline for Definition of Managed Object (GDMO) which is an OSI specification for defining a management information structure used in the CMISE environment. SNMP is an IETF defined network management protocol including definitions of a database and associated concepts. In the SNMP subsystem 52 , the data model 42 is an entity-relationship model in accordance with SNMP standards. TL-1 is an ASCII or man-machine management protocol defined by Bellcore and typically used to manage broadband and access equipment in North America. In the TL-1 subsystem 54 , the data model 42 includes a data dictionary for access identifiers (AIDs) and commands in accordance with TL-1 standards. In this way, the data models 42 only occupy a small amount of memory resources in the network element 10 and keep protocol-specific processing local to each subsystem 50 , 52 , or 54 .
The common MIB 32 includes an application interface (API) 60 , a transaction queue 62 , a set of response queues 64 , and a database 66 . The API 60 provides generic management functionality to the CMISE, SNMP, and TL-1 subsystems 50 , 52 , and 54 . As described in more detail below, the common MIB 32 provides an efficient and flexible component to allow a telecommunications device to be controlled and monitored by external interfaces using specific management protocols.
The API 60 includes an interface object 70 for each subsystem 30 registered with the API 60 , one or more command objects 72 for each registered subsystem 30 , and a set of managed entity (ME) classes 74 to which protocol-specific transactions are mapped by the subsystems 30 . As described in more detail below, by applying object-oriented modeling techniques, the information of the hardware and/or software resource is encapsulated into the class definition, which then provides service interfaces to other software components.
The interface objects 70 are each accessed by a corresponding subsystem 30 to communicate with the API 60 . The interface object 70 for a subsystem 30 is created by the API 60 upon registration by the subsystem 30 . At that time, the subsystem 30 requests a number of command objects 72 that can be simultaneously used by the subsystem 30 , which are generated and allocated by the API 60 .
The command objects 72 each encapsulate a base class 76 for the ME classes 74 . The ME classes 74 each include specific functionality for an ME type. The base class 76 includes function calls, methods, parameters, behaviors, and other attributes shared by all or at least some of the ME classes 74 . Accordingly, each command object 72 includes base functionality that is used by the ME classes 74 to access the database 66 or perform functions within the common MIB 32 , such as communicating with the low level software driver 34 in order to determine or change the state of hardware in the NE 10 . As described in more detail below, portions of the base class 76 may be overwritten by specific ME classes 74 when forming an ME command object 78 . The ME command object 78 forms an interface for accessing ME attributes and functions in the database 66 and the low level software driver 34 . In this way, each ME class 74 may select functionality from the base class 76 to be used in accessing the corresponding ME.
The transaction queue 62 stores ME command objects 78 generated by the API 60 in conjunction with the subsystems 30 for processing by the common MIB 32 . In one embodiment, the transaction queue 32 is a first-in-first-out (FIFO) buffer that serializes processing in the common MIB 32 to prevent multiple operations from being performed at the same time, and thus prevent corruption of data, data contention, and race conditions within the common MIB 32 .
In the database 66 , attributes for each of the ME types are stored in ME data structures 80 . Preferably, the data structures are non-volatile structures to ensure data integrity. In one embodiment, the database 66 is a relational database and the ME data structures 80 are relational database tables. It will be understood that the ME attributes may be otherwise suitably stored without departing from the scope of the present invention.
The response queues 64 store responses to transactions processed by the common MIB 32 . In one embodiment, the response queues 64 include a discrete queue for each subsystem 30 . In this embodiment, each subsystem 30 reads responses in its corresponding queue 64 and extracts data for generating a protocol-specific response for transmission to the management station originating the transaction. It will be understood that responses to transactions may be otherwise made available by the common MIB 32 to the subsystems 30 .
FIG. 2 illustrates details of the object interfaces 70 , command objects 72 , and ME class objects 74 in accordance with one embodiment of the present invention. In this embodiment, the objects 70 , 72 , and 74 are each fully instantiated objects encapsulating both data and behavior and inheriting data and behavior from parent classes.
Referring to FIG. 2, the interface object 70 includes client callback, client quality of service (QoS), client command objects, and client interface parameters. The interface object 70 calls an associated command object 72 in the API 60 .
The command objects 72 include command methods, command correlation, command errors, and command parameters. The command object 72 further inherits attributes of the base class 76 . As previously described, the base class 76 includes common ME attributes and common ME methods.
The ME class objects 74 each include functionality associated with a particular ME type. Such functionality includes ME attributes, methods, parameters, and behavior for the ME type. Attributes of an ME class 74 are inherited by the command objects 72 through the base class 76 to generate the ME command object 78 . As previously described, the ME command object 78 provides an interface for accessing data and functionality in the common MIB 32 .
FIG. 3 illustrates details of an ME command object 78 in accordance with one embodiment of the present invention. In this embodiment, the ME command object 78 is self contained. Any system resources obtained, such as memory or buffers are “owned” by the object 78 and released when the object 78 is destructed. It will be understood that the ME command object 78 may be otherwise suitably implemented for accessing data and attributes and common MIB 32 .
Referring to FIG. 3, the ME command object 78 includes a public data section 100 and a private data section 102 . The public data section 100 of the ME command object 78 is accessible by the client subsystem 30 . The public data section 100 includes method functions that hide the structure, data manipulation, and allocation details from the client subsystem 30 . In addition, the methods in the public data section 100 respond to affects of the methods chosen and perform any command integrity checks required.
In one embodiment, the methods may include inline functions, particularly those used for setting and retrieving small (typically integer) attribute values. Attribute methods, for example, will be available to populate get/set/create commands, and to retrieve values resulting from the same. Constructor, invoker, and releaser methods will be used to create, execute, and destroy ME command objects 78 . Behavior methods are used by common MIB 32 to execute the commands.
The private data section 102 of the ME command object 78 includes data to complete the command. The response data for successful or error return will also be contained in the private data section 102 . In one embodiment, any miscellaneous system resources dynamically allocated for the command are retained in the private data section 102 . This type of allocation is preferably minimized.
FIG. 4 is a flow diagram illustrating a method for performing a management transaction in accordance with one embodiment of the present invention. In this embodiment, the transaction may be received from any one of the plurality of management stations in a management protocol supported by the NE 10 .
Referring to FIG. 4, the method begins at step 110 in which subsystem 30 receives a transaction in a specific management protocol. Next, at step 112 , the subsystem 30 maps the protocol specific transaction to a protocol independent ME class 74 which will be used by the common MIB 32 to perform the transaction. Mapping may include any suitable type of transaction, conversion, or associations. Accordingly, protocol specific processing is retained at the subsystem level.
At step 114 , the subsystem 30 opens a communications session with the API 60 . As previously described, the session may be opened by calling an interface object 70 in the API 60 corresponding to the subsystem 30 . Proceeding to step 116 , the subsystem 30 requests a command object 72 from the API 60 . The subsystem 30 may use any number of command object 72 at a time up to the number allocated to the subsystem 30 in the API 60 .
At step 118 , the subsystem 30 identifies the protocol independent ME class 74 to which the protocol specific transaction was mapped. Next, at step 120 , the API 60 generates and returns an ME command object 78 to the subsystem 30 . As previously described, the ME command object 78 includes attributes of the base class 76 and the ME class 74 . Portions of the ME class 74 may overload portions of the base class 76 to provide specific functionality in place of base functionality. At step 122 , the subsystem 30 populates the ME command object 78 based on the transaction by calling command functions stored in the ME command object 78 .
Proceeding to step 124 , the populated ME command object 78 is transferred to the transaction queue 62 in common MIB 32 for processing. The transaction queue 32 serializes processing in common MIB 32 to prevent data contention between co-pending ME command objects 78 . At step 126 , the ME command object 78 is removed from the transaction queue 62 and executed by the common MIB 32 . During execution, the ME command object 78 accesses the corresponding ME table 80 and/or performs functions in accordance with functions, behaviors, and parameters in the ME command object 78 which are based on the transaction.
Next, at step 128 , the common MIB 32 generates a response in accordance with the function calls in the ME command object 78 . At step 130 , the response is transferred to the response queue 64 for the subsystem 30 that generated the ME command object 78 . Next, at step 132 , the subsystem 30 extracts data from the response and generates a protocol specific response for transfer back to the requesting management station. At step 134 , the subsystem 30 releases the command object 72 back to the API 60 . In this way, the common MIB 32 provides a layer of abstraction to isolate data representations internal to the. network element 10 from data representations made externally to the network element 10 . Data integrity and consistency is guaranteed as only a single database is maintained.
Although the present invention has been described with several embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present invention encompass such changes and modifications as fall within the scope of the appended claims. | In accordance with one embodiment of the present invention, a network element comprises a first subsystem operable to receive management transactions in a first management protocol and to map the transactions to a common management protocol. A second subsystem is operable to receive management transactions in a second management protocol and to map the transactions to the common management protocol. A common management information base (MIB) includes a dataset and a common interface to the dataset. The common interface is operable to access the dataset to process transactions received from the first and second subsystems in the common management protocol. | 8 |
Application 09/857,906 filed Jan. 4, 2002 the National Stage entry of PCT/US99/29091 filed Dec. 8, 1999 which claims priority to Provisional 60/111,472 filed Dec. 9, 1998.
FIELD OF THE INVENTION
This invention relates generally to absorbent dressings, and more particularly highly-absorbent synthetic polymer dressings having antimicrobial agents attached thereto.
BACKGROUND OF THE INVENTION
Bacterial growth in absorbent dressings for wounds, urinary incontinence diapers, and menstruation pads can lead to serious medical complications as well as social difficulties. For example, bacterial growth in urinary incontinence diapers or menstruation pads usually produces among, unpleasant odors that are socially unacceptable and can cause persons to alter their lifestyle. Conventional absorbent pads for urinary incontinence and menstruation are not inherently bactericidal. Consequently, the only way to avoid growth of bacteria in the absorbent dressings is to change them at frequent intervals, even if the absorbent capacity of the pad has not been reached. In the area of wound dressings, bacterial contamination of acute wounds and infection of chronic skin wounds are major clinical problems that can result in significant morbidity and, in severe cases, mortality. Conventionally, wound dressings have been designed to absorb wound fluids and yet provide a moist environment for promoting wound healing. However, such moist environments create a nutrient rich reservoir for bacterial growth in the dressing. Bacteria growing in the dressing can be shed back into the wound, increasing the risk of wound infection, or response to toxins, and producing strong, foul odors.
In an effort to address these problems, antibiotics or chemical disinfectants are frequently applied topically to wounds prior to covering the wound with a dressing. Alternatively, topical agents are sometimes applied directly to the surface of the dressing. To control foul odors, some known dressings incorporate charcoal powder to absorb molecules generating the foul odor. For some applications, topical application of antibacterial agents is not desirable. For instance, bactericidal agents applied topically to wound dressings have a tendency to seep into the wound being treated. Furthermore, many antimicrobial drugs, such as iodine, are cytotoxic and will retard wound healing if used repetitively or at high concentrations.
A composition comprising a superabsorbent polymer having a monolayer (or near monolayer) of silane antimicrobial agent in a covalent bonding relationship with the base polymer is disclosed in U.S. Pat. No. 5,045,322. The composition may be in the form of flakes, strips, powders, filaments, fibers or films, and may be applied to a substrate in the form of a coating. The aforementioned composition is less apt to enter a wound vis-a-vis conventional topical treatment systems. In that respect, the disclosed composition provides an improvement over conventional topical treatment systems. However, silanes contain siloxane bonds which can be cleaved by acids and bases produced by infection or bacterial growth. In turn, these reactions may weaken or destroy bends between the silane antimicrobial agent and the underlying polymer. Consequently, antimicrobial agent may seep into a wound and retard wound healing.
The need exists for an improved antimicrobial dressing composition having an antimicrobial agent which can be maintained securely attached to a superabsorbent polymer upon exposure to acids and bases produced by infection and bacterial growth. In addition to reducing the propensity for detachment of the antimicrobial agent, it would be desirable to provide a surface area enhanced dressing structure for increasing the effectiveness of the antimicrobial agent.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an inherently bactericidal superabsorbant dressing having an enhanced surface area.
It is another object of the present invention to provide an inherently bactericidal superabsorbant dressing having an improved bactericidal attachment structure that resists degradation upon exposure to acids or bases produced, for instance, during bacterial growth.
These and other objects are achieved by the inherently bactericidal polymer composition and the present invention. In the preferred embodiment, the composition comprises a polymer matrix having quaternary ammonium groups tethered to its surface through non-siloxane bonds. The surface area of the polymer matrix is enhanced, for instance, by electrostatically spinning a fiber-forming synthetic polymer to form a frayed fiber or filament. Alternatively, the polymer solution can be wet- or dry-spun to create a roughened fiber surface by controlling the choice of solvent and the polymer solution temperature. Additional surface area enhancement is provided by tethering molecular chains of quaternary ammonium pendent groups to the surface of the polymer matrix. Tethering may be accomplished by known techniques such as grafting and selective adsorption.
In an alternate embodiment of the invention, non-ionic bactericidal molecules are coupled to the surface of the polymer matrix, in lieu of ionically-charged molecules. Ionically-charged molecules are prone to being neutralized upon encountering oppositely-charged molecules. For instance, positively-charged quaternary ammonium groups may be neutralized by negatively-charged chloride ions present in physiological fluids. In instances were such neutralization is significant enough to reduce the bactericidal properties of the dressing below an acceptable level, non-ionic surface groups may be preferable.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A novel antibacterial polymer composition is fabricated to have an enhanced surface area and superabsorbent capacity for biological fluids, including urine, blood, and wound exudate.
In the preferred embodiment of the present invention, the composition includes a polymer matrix having quaternary ammonium compounds attached to the surface of the polymer matrix. The polymer matrix is comprised of a plurality of hydrophilic fibers or filaments which can be fabricated in any suitable manner. For example, suitable fibers or filaments can be fabricated by wet- or dry-spinning a fiber-forming synthetic polymer from a spinning solvent. The resulting polymer has superabsorbent capacity. Generally, polymers capable of absorbing from about thirty to sixty grams of water per gram of polymer are considered to be superabsorbent. Examples of superabsorbent polymers which can be fabricated in this manner include polyacrylic acids, polyethylene oxides and polyvinyl alcohols. For example, methods for spinning polyethylene oxide using acetone solvent are well known.
Significantly, the polymer matrix is fabricated to have an enhanced surface area. Enhancing the surface area of the polymer matrix results in improved absorption of biological fluids, and increases the availability of sites for attachment of the antimicrobial quaternary ammonium compounds. A corresponding increase in the quantity and density of antimicrobial sites, in turn, enhances the efficacy of the composition in killing organisms such as bacteria and viruses.
It may occur to one skilled in the art of polymer science that a variety of methods are available for accomplishing surface area modification. Preferably, surface area enhancement is accomplished by a modified spinning or casting method. For instance, electrostatic spinning is a modified spinning technique which results in fraying of the fiber as it exits the spinerette. Alternatively, a polymer solution can be wet- or dry-spun to create a roughened fiber surface by controlling the solvent type and the polymer solution temperature. This technology is well known and has been applied, for example, in the manufacture of asymmetric membranes having roughened pores for dialysis. The size of the roughened pores is primarily controlled by the speed of precipitation which, in turn, is controlled by solvent interaction parameters, temperature, etc.
The surface area of the polymer composition is further enhanced by tethering chains of antimicrobial groups to the outer surface of the individual polymer fibers. Preferably, molecular chains of quaternary ammonium pendent groups are fabricated to have at least one end adapted for attachment to a fiber surface. For instance, surface grafting may be accomplished by creating surface free radicals as initiation sites from peroxide generation (ozone or microwave). Alternatively, surface attachment of an interpenetrating network may be achieved using a monomer which swells the substrate polymer. The incorporation of tethered antimicrobial chains has the further benefit of enhancing the functionality of the composition. In particular, the tethered antimicrobial chains extend into the particular biological solution to bind to harmful bacterial and viral organisms. In contrast to known dressing compositions in which a monolayer (or near monolayer) of bactericidal compound is directly attached to a fiber surface, the chain structures of the present invention, which function like arms extending outwardly from the fiber surface, more effectively bind the antimicrobial sites to harmful organisms. Preferably, tethering is accomplished by grafting the antimicrobial chains directly to the matrix surface, or by selective adsorption of a copolymer to the matrix surface.
Grafting techniques are well known in the art. For example, quaternary ammonium compound grafting using the monomer trimethylammonium ethyl methacrylate to graft polymerize to a modified polyethylene surface is described by Yahaioui (Master's Thesis, University of Florida, 1986). Yahioui describes a grafting technique in which a plasma discharge is used to create free radicals which initiate polymerization of appropriate monomers. Selective adsorption of appropriate block copolymers can also be used.
In contrast to known compositions in which an antimicrobial structure is achieved by covalently bonding silane groups to the surface of the base polymer, the present invention incorporates a chemical structure which is based on polymerization (i.e., surface grafting) of monomers containing all carbon-carbon, carbon-oxygen and carbon-nitrogen main bonds, such as the dialkly, diallyl, quaternary ammonium compounds. Consequently, the composition of the present invention results in a structure which is less prone to reacting with acids and bases produced by bacterial growth. As previously mentioned, such reactions can degrade the attachment between the matrix and antimicrobial groups. In instances where the composition is applied to a wound dressing, such degradation could result in antimicrobial agents detaching from the polymer matrix and entering a wound site. In some cases, this can have the deleterious effect of retarding wound healing.
In an alternate embodiment of the present invention, anionic antibactericidal groups are immobilized on the surface of a superabsorbant dressing to improve the antibactericidal efficacy of the dressing. The positive charge associated with quaternary ammonium groups, for example, can be neutralized by negative ions, such as chloride ions present in physiological fluids such as urine and plasma. For applications where the degree of neutralization will significantly reduce the effectiveness of the antibactericidal agent, anionic surface groups can be substituted for quaternary ammonium groups. Examples of chemical compounds that can be used to produce immobilized anionic surface groups include Triton-100, Tween 20 and deoxycholate. For instance, Triton-100 contains a free hydroxyl group which can be derivatized into a good leaving group, such as tosyl or chloride, and subsequently reacted with a base-treated polymer, such as methyl cellulose, to yield a surface immobilized non-ionic surfactant.
Dimethyldiallyl ammonium chloride is one example of a suitable monomer which may be used with the present invention. This monomer, commonly referred to as DMDAC or DADMAC, is used in the fabrication of commercial flocculating polymers. Modifications of trialkyl(p-vinylbenzyl) ammonium chloride or the p-trialkylaminoethyl styrene monomers are also suitable. One such example is trimethyl(p-vinyl benzyl) ammonium chloride; the methyl groups of this monomer can be replaced by other alkyl groups to impart desired properties. Alternatively, methacrylate-based monomers may be used; however, they may suffer from hydrolytic instability under acidic and basic conditions in a fashion similar to the silane-based treatments of the prior art. Consequently, methacrylate-based monomers are not preferred.
While the preferred embodiments of the invention have been illustrated and described, it will be clear that the invention is not so limited. Numerous modifications, changes, variations, substitutions and equivalents will occur to those skilled in the art without departing from the spirit and scope of the present invention as described in the claims. | Absorbent dressings, including highly-absorbent dressings having antimicrobial polymer attached thereto via non-siloxane bonds are disclosed. Bandages (i.e. wound dressing), sanitary napkins and the like are useful applications for the intrinsically bactericidal absorbent dressings whose method of manufacture and use are disclosed and claimed. | 0 |
This application is a continuation-in-part of Ser. No. 10/685,920, filed Oct. 15, 2003, now U.S. Pat. No. 6,902,064.
BACKGROUND OF THE INVENTION
1. The Technical Field
The present invention is directed to packaging for grouped similar items, including elongated items such as drill bits or the like, and further including packaging adapted to be hung from retail shelving.
2. The Prior Art
There are many ways to package and present in a retail environment, elongated items, such as drill bits, jigsaw blades and the like, including skin cards, clamshell blister packs, plastic bags, and molded or stamped boxes. Such elongated items may be sold in a variety of basic ways: the single article (or at most 2–3 if small) in a package; a quantity of, e.g. 5–10 identical articles in a package; an organized set of different, but related articles (e.g., a set of an indeterminate number of articles of varying size, grade, etc.).
Presenting a single article in a package may be advantageous, in that in a transparent package, e.g., a bag or skin card, all or substantially all of the surface of the individual article may be exposed for visual inspection or even (in a thin bag or wrapper) tactile inspection.
However, single article packaging can be problematic in that it can occupy more storage and shipping volume that a comparable number of like articles packaged in bunches. Furthermore, if a customer is purchasing a large quantity of single articles, there can be more checkout time involved.
However, plural article packaging can be problematic as well, for elongated articles such as drill bits and the like. Such packaging may typically may be fabricated from plastic or paper. Plastic may be difficult to affix identifying and marketing indicia, consumer information and the like in a manner which does not obscure the visibility of the products inside. Paper may permit indicia placement but likewise typically obscures visibility of the articles being presented.
It would be desirable to provide a method for packaging plural identical articles, such as elongated articles like drill bits, which has the advantages of single article packaging, such as enabling visual inspection of the articles.
It would also be desirable to provide a method for packaging of plural identical articles, which provides for the placement of such indicia as may be desired by the manufacturer or required by law, while still permitting visual inspection.
These and other desirable characteristics of the present invention will become apparent in view of the present specification, including claims, and drawings.
SUMMARY OF THE INVENTION
The present invention comprises in part, a package of a plurality of like articles, having a longitudinal axis and a transverse axis. The package comprises a first sleeve, having a length, a top end and a bottom end; and a second sleeve, insertingly received within the first sleeve and having a length greater than the length of the first sleeve, a top end and a bottom end, so that the first sleeve overlaps at least a portion of the second sleeve in a region of overlap.
A first closure line extends along at least a portion of the region of overlap. The first closure line joins longitudinally extending inner surfaces of the first sleeve to adjacent longitudinally extending outer surfaces of the second sleeve, and opposing longitudinally extending inner surfaces of the second sleeve to each other,
A second closure line extends transversely across at least a portion of the region of overlap. The second closure line joins transversely extending inner surfaces of the first sleeve to adjacent transversely extending outer surfaces of the second sleeve, and opposing transversely extending inner surfaces of the second sleeve to each other;
The first and second closure lines define first and second chambers in the second sleeve, the first chamber being larger than the second chamber, and third and fourth chambers between the first and second sleeves, on opposite sides of the first chamber in the second sleeve.
A plurality of articles are disposed in the first chamber, and a single article is disposed in the second chamber.
A third closure line extends transversely across the second sleeve in a region beyond the region of overlap, and joins transversely opposing inner surfaces of the second sleeve, with the plurality of articles and the single article being disposed between the second and third closure lines, to maintain the plurality of articles and the single article captured within the first and second chambers, respectively.
In a preferred embodiment of the invention, each of the first and second sleeves is one of: transparent, translucent.
The package preferably further comprises at least one sheet disposed in at least one of the third and fourth chambers disposed between the first and second sleeves, on opposite sides of the first chamber in the second sleeve. The at least one sheet preferably has indicia disposed thereon.
The package preferably further comprises a fifth chamber, disposed between the third closure line and the top of the second sleeve. A reinforcement sheet is disposed in the third chamber between the third closure line and the top of the second sleeve. A fourth closure line is disposed between the reinforcement sheet and the top of the second sleeve, to maintain the reinforcement sheet captured between the third and fourth closure lines. An aperture is formed through the second sleeve and the reinforcement sheet, for enabling the package to be suspended by a member passing through the aperture.
Preferably, the top end of the second sleeve is longitudinally spaced apart from the top end of the first sleeve. The bottom end of the second sleeve is preferably disposed proximate the bottom end of the first sleeve. The second sleeve preferably has a width which is less than the width of the first sleeve.
The plurality of articles disposed in the first chamber are preferably all like articles, and the single article disposed in the second chamber is the same as one of the plurality of like articles. Preferably, the first and second sleeves comprise substantially flattened tubes.
The present invention also comprises, in part, a method for forming a package, the package having a longitudinal axis and a transverse axis. The method comprising the steps of:
forming a first sleeve, having a length, a top end and a bottom end; forming a second sleeve, having a length greater than the length of the first sleeve, a top end and a bottom end; inserting the second sleeve into the first sleeve, so that the first sleeve overlaps at least a portion of the second sleeve in a region of overlap; forming a first closure line, extending along at least a portion of the region of overlap, to join longitudinally extending inner surfaces of the first sleeve to adjacent longitudinally extending outer surfaces of the second sleeve, and opposing longitudinally extending inner surfaces of the second sleeve to each other, forming a second closure line, extending transversely across at least a portion of the region of overlap, to join transversely extending inner surfaces of the first sleeve to adjacent transversely extending outer surfaces of the second sleeve, and opposing transversely extending inner surfaces of the second sleeve to each other; the first and second closure lines defining first and second chambers in the second sleeve, the first chamber being larger than the second chamber, and third and fourth chambers between the first and second sleeves, on opposite sides of the first chamber in the second sleeve; placing a plurality of articles in the first chamber; placing a single article in the second chamber; forming a third closure line, extending transversely across the second sleeve in a region beyond the region of overlap, to join transversely opposing inner surfaces of the second sleeve, with the plurality of articles and the single article being disposed between the second and third closure lines, to maintain the plurality of articles and the single article captured within the first and second chambers, respectively.
The steps of forming the first and second sleeves, preferably further comprise the step of forming each of the first and second sleeves from one of transparent or translucent material.
The method preferably further comprises the step of:
placing at least one sheet in at least one of the third and fourth chambers disposed between the first and second sleeves, on opposite sides of the first chamber in the second sleeve.
The method preferably further comprises the step of placing indicia on the at least one sheet.
The method preferably further comprises the steps of:
forming a fifth chamber, disposed between the third closure line and the top of the second sleeve; placing a reinforcement sheet in the third chamber between the third closure line and the top of the second sleeve; forming a fourth closure line, between the reinforcement sheet and the top of the second sleeve, to maintain the reinforcement sheet captured between the third and fourth closure lines; and forming an aperture through the second sleeve and the reinforcement sheet, for enabling the package to be suspended by a member passing through the aperture.
The method preferably further comprises the step of:
positioning the top end of the second sleeve in longitudinally spaced apart relation to the top end of the first sleeve.
The method preferably further comprises the step of:
positioning the bottom end of the second sleeve proximate the bottom end of the first sleeve.
The method preferably further comprises the step of:
forming the second sleeve with a width which is less than the width of the first sleeve.
The method preferably further comprises the steps of:
selecting the plurality of articles disposed in the first chamber to be all like articles, and selecting the single article disposed in the second chamber to be the same as one of the plurality of like articles.
Preferably, the first and second sleeves are formed as substantially flattened tubes.
The invention further comprises in part, a package of a plurality of like articles, having a longitudinal axis and a transverse axis. First and second inner layers are provided, each having a width, extending along the transverse axis, and a height, extending along the longitudinal axis. The first and second inner layers are joined to one another along at least three longitudinally extending closure lines to form at least two inner chambers, for receiving articles to be packaged, the at least two inner chambers being bounded by the at least three closure lines and the first and second inner layers. The first and second inner layers are joined at least along respective bottom edge regions thereof. First and second outer layers are provided, each having a width, extending along the transverse axis, and a height extending along the longitudinal axis. The first and second outer layers are disposed adjacent the first and second inner layers, respectively. The first and second outer layers are joined to their respective adjacent first and second inner layers along at least two longitudinally extending closure lines to form at least one outer chamber. The first and second outer layers are joined, at least indirectly, at least along respective bottom edge regions thereof. A plurality of articles is disposed in at least one of the at least two inner chambers, and a number of articles is disposed in an other one of the at least two inner chambers, less than the plurality of articles disposed in the at least one of the at least two inner chambers.
In an embodiment of the invention, the first and second inner layers are contiguously, monolithically formed together along their respective bottom edge regions. Alternatively, the first and second inner layers may comprise separate sheets of material that have been sealed together along their respective bottom edge regions.
The first and second outer layers may be contiguously, monolithically formed together along their respective bottom edge regions. Alternatively, the first and second layers may comprise separate sheets of material that have been sealed together along their respective bottom edge regions.
Each of the first and second inner layers and first and second outer layers is one of: transparent, translucent, opaque.
The package may further comprise at least one sheet disposed in at least one outer chamber. The at least one sheet may have indicia disposed thereon.
The package preferably further comprises a further closure line, extending transversely across and sealing joining top edge regions of the first and second inner layers.
The top edge regions of the first and second inner layers are preferably longitudinally spaced apart from top edge regions of the first and second outer layers.
The bottom edge regions of the first and second inner layers are preferably disposed proximate the bottom edge regions of the first and second outer layers.
The first and second outer layers may have widths that are less than the widths of the first and second inner layers.
The plurality of articles disposed in the at least one of the at least two inner chambers, may be all like articles, and the number of articles disposed in the other one of the at least two inner chambers may be the same as those of the plurality of like articles.
The present invention also comprises, in part, a method for forming a package of a plurality of like articles, having a longitudinal axis and a transverse axis, the method comprising the steps of:
forming first and second inner layers, each having a width, extending along the transverse axis, and a height, extending along the longitudinal axis, joining the first and second inner layers to one another along at least three longitudinally extending closure lines to form at least two inner chambers, for receiving articles to be packaged, the at least two inner chambers being bounded by the at least three closure lines and the first and second inner layers, joining the first and second inner layers at least along respective bottom edge regions thereof; forming first and second outer layers, each having a width, extending along the transverse axis, and a height extending along the longitudinal axis, disposing the first and second outer layers adjacent the first and second inner layers, respectively, joining the first and second outer layers to their respective adjacent first and second inner layers along at least two longitudinally extending closure lines to form at least one outer chamber, joining the first and second outer layers, at least indirectly, at least along respective bottom edge regions thereof; placing a plurality of articles in at least one of the at least two inner chambers, and placing a number of articles in an other one of the at least two inner chambers, less than the plurality of articles disposed in the at least one of the at least two inner chambers.
The method may further comprise the step of contiguously, monolithically forming the first and second inner layers together along their respective bottom edge regions. The method may alternatively further comprise the step of forming the first and second inner layers as separate sheets of material that have been sealed together along their respective bottom edge regions.
The method may comprise the step of contiguously, monolithically forming the first and second outer layers together along their respective bottom edge regions. The method may alternatively further comprise the step of forming the first and second layers as separate sheets of material that have been sealed together along their respective bottom edge regions.
The method may further comprise the step of forming each of the first and second inner layers and first and second outer layers as one of: transparent, translucent, opaque.
The method may further comprise the step of placing at least one sheet in at least one outer chamber, and may also comprise the further step of placing indicia on the at least one sheet.
The method may further comprise the step of forming a further closure line, extending transversely across and sealing joining top edge regions of the first and second inner layers.
The method may further comprise the step of positioning the top edge regions of the first and second inner layers in longitudinally spaced apart relationship from top edge regions of the first and second outer layers.
The method may further comprise the step of positioning the bottom edge regions of the first and second inner layers proximate the bottom edge regions of the first and second outer layers.
The method may further comprise the step of providing the first and second outer layers with widths that are less than the widths of the first and second inner layers, and may further comprise the steps of selecting the plurality of articles disposed in the at least one of the at least two inner chambers, to be all like articles, and selecting the number of articles disposed in the other one of the at least two inner chambers to be the same as those of the plurality of like articles.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation of two components of a package for similar articles, according to a preferred embodiment of the invention.
FIG. 2 is an elevation of the two components of FIG. 1 in partially assembled configuration.
FIG. 3 is a sectional view of the assembly of FIG. 2 , taken along line 3 — 3 of FIG. 2 .
FIG. 4 is an elevation of the assembly of FIG. 3 , shown further along the fabrication process.
FIG. 5 is a sectional view of the assembly of FIG. 4 , taken along line 5 — 5 of FIG. 4 .
FIG. 6 is an elevation of the assembly of FIG. 4 , showing the insertion of elongated articles into respective receiving chambers of the package in formation.
FIG. 7 is an elevation of the assembly of FIG. 6 , showing the insertion of indicia bearing sheets, as well as a reinforcement sheet for enabling the hanging display of the package.
FIG. 8 is an enlarged sectional view of the assembly of FIG. 7 , taken along line 8 — 8 of FIG. 7 .
FIG. 9 is a perspective exploded view of two components of a package for similar articles, according to an alternative preferred embodiment of the invention.
FIG. 10 is a perspective view of a package according to the embodiment of FIG. 9 , with the indicia bearing sheets and articles to be packaged omitted.
FIG. 11 is a side elevation of the exploded assembly of FIG. 9 .
FIG. 12 is a perspective exploded view of two components of a package for similar articles, according to an another alternative preferred embodiment of the invention.
FIG. 13 is a perspective view of a package according to the embodiment of FIG. 12 , with the indicia bearing sheets and articles to be packaged omitted.
FIG. 14 is a side elevation of the exploded assembly of FIG. 12 .
FIG. 15 is a perspective exploded view of two components of a package for similar articles, according to an still another alternative preferred embodiment of the invention.
FIG. 16 is a perspective view of a package according to the embodiment of FIG. 15 , with the indicia bearing sheets and articles to be packaged omitted.
FIG. 17 is a side elevation of the exploded assembly of FIG. 15 .
FIG. 18 is a perspective exploded view of two components of a package for similar articles, according to an yet another alternative preferred embodiment of the invention.
FIG. 19 is a perspective view of a package according to the embodiment of FIG. 18 , with the indicia bearing sheets and articles to be packaged omitted.
FIG. 20 is a side elevation of the exploded assembly of FIG. 18 .
FIG. 21 is a perspective view of an unassembled package according to an alternative embodiment in which the outer layer has a lesser width than the inner layer.
FIG. 22 is a front elevation of an assembled package according to the embodiment of FIG. 10 , with the packaged articles and Indicia bearing sheets being omitted for clarity of illustration.
FIG. 23 is a front elevation of an assembled package (in which the articles packaged have been omitted to facilitate illustration), according to a further embodiment of the invention.
FIG. 24 is a perspective view of the unassembled package according to the embodiment of FIG. 23 , showing the different ways in which the package may be formed.
DETAILED DESCRIPTION OF THE INVENTION
While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will be described in detail several specific embodiments, with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments illustrated.
A package for a plurality of similar articles according to a preferred embodiment of the invention is formed first, as shown in FIG. 1 , by forming two sleeves 10 and 12 , each of which is preferably formed (e.g., by cutting to desired length), tubular plastic material (of any suitable type—typically cut from a roll of flattened tube), which are preferably transparent, or alternatively translucent, but which will permit visual inspection of anything within the respective sleeves.
Sleeve 10 includes open ends 14 and 16 , while sleeve 12 includes open ends 16 and 18 . The material of sleeves 10 and 12 is preferably susceptible to welding to itself, e.g., by pressure, heat, microwave or ultrasonic vibrations. Sleeve 10 is inserted into sleeve 12 which preferably has a circumference which is slightly greater than the circumference of sleeve 10 , in order to facilitate the insertion of sleeve 10 into sleeve 12 . Alternatively, sleeve 10 may have a circumference that is the same as or greater than that of sleeve 12 , though this may make insertion of sleeve 10 into sleeve 12 more difficult, as well as making later fabrication steps slightly more difficult. In addition, sleeve 10 has a length which is preferably substantially greater than the length of sleeve 12 .
Upon insertion, sleeves 10 and 12 form assembly 30 , in which open end 16 of sleeve 10 is preferably substantially aligned with the end 20 of sleeve 12 , although the respective ends may be unaligned if desired.
The third stage of the package formation occurs when welds 32 and 34 are provided, extending through both sleeves 10 and 12 , to form assembly 40 , creating chambers 42 , 44 , 46 , and 48 . Weld 34 closes off the bottoms 16 and 20 of sleeves 10 , 12 , respectively, while weld 32 creates a vertical separation of the volume within sleeve 10 . Preferably, weld 32 is off-center, so that chamber 42 is appropriately sized for a single article 50 , while chamber 46 is appropriately sized to receive a plurality of like articles 50 .
Although chambers 44 , 48 are, strictly speaking, contiguous, because of the fact that they are, due to the typically flattened nature of sleeves 10 , 12 , on generally opposite sides of chamber 46 , it is useful to consider them as separate and discrete chambers. In instances in which the bulk of the articles being packaged causes the package to assume a less than flattened configuration, it may be desirable to provide further welds, extending longitudinally at the sides of the region of overlap of tubes 10 , 12 , so that fully discrete and discontinuous chambers are created.
While welds, as described above are preferably used to create the separations between the various chambers of the package described herein, as being the most efficient and amenable to manufacturability, other methods of creating the welds (or closure lines) may be employed, such as staples or stitching, for example. Further, the welds or closure lines, while preferably extending continuously and completely across the height or width of the respective sleeves to which they are applied, may instead be intermittent, and may stop short of peripheral edges of the respective sleeves or at other locations, so long as the function of restraining the articles being packaged within their respective regions is accomplished.
Articles 50 are inserted into chambers 42 , 46 , after welds 32 , 34 have been accomplished. Articles 50 are shown representationally as drill bits, but may be any elongated articles (e.g., center punches, etc.). Even non-elongated articles may be accommodated, by suitably modifying the relative dimensional proportions of the chambers created by the overlapped sleeves and the subsequently created welds.
After the articles 50 have been inserted, they are sealed in place by weld 52 , which extends across sleeve 10 , but does not contact the top of sleeve 12 , thus leaving the tops of chambers 44 , 48 still open, and as well leaves the top of sleeve 10 , above weld 52 , likewise open for insertion of further items. Sheets 54 , 56 may be provided with various indicia (product name, product information, UPC bar code(s), etc.) as desired or required by law. Sheets 54 , 56 may be fabricated from any suitable material capable of bearing indicia, and once prepared and suitably printed, are inserted into chambers 44 , 48 , respectively.
As the side shown in FIG. 7 is preferably the nominal “front” of the package, it is intended to be placed on a shelf, so that sheet 56 faces front. Sheet 56 preferably is “shorter” than the articles 50 (e.g., drill bits), so that the tops of the articles will be visible, while sheet 54 may or may not be of equal or greater length than articles 50 . Sheet 54 will be rotated 180 degrees (as indicated by the arrow), so that its indicia face to the rear (although either sheet may be provided with indicia on both sides, as necessary or desired).
Once sheets 54 , 56 have been inserted, a further weld may be placed across the tops of chambers 44 , 48 . However, in usual practice this may not be necessary, as sheets 54 , 56 will be sized so that the fit of each within its respective chamber 44 , 48 will be sufficiently snug enough that sheets 54 , 56 will not fall out, subsequent to fabrication, to prevent sheets 54 , 56 from being dislodged during shipment, through placement on retail shelving, up to purchase by a consumer.
The placement of sheets 54 , 56 in the chambers 44 , 48 , rather than immediately adjacent to articles 50 is advantageous, in that articles 50 , which may be, e.g., drill bits or other tool parts, may be coated with oil or other materials, for example, to prevent rusting or other damage to the articles, pending purchase by the consumer. This coating may be harmful or detrimental to the indicia that is printed on the sheets, in that it may blur the printing or adversely affect the material of the sheets themselves. By placing the sheets 54 , 56 within chambers 44 , 48 , they are isolated from the articles, and cannot be affected by them or any coating or the like.
After placement of the sheets, and possible, though not required, welding of the tops of chambers 44 , 48 , the package is then prepared for hanging. Depending upon the strength of the material, the top of sleeve 10 may be simply closed by a further weld 58 . Alternatively, a further sheet 60 (which may or may not also have indicia placed on it) is inserted above weld 52 , prior to placement of weld 58 , to provide reinforcement strength for enabling the package to be hung on a peg, rod or hook. Once in place, a hole 62 is formed through the layers of sleeve 10 and sheet 60 , in any suitable shape that is appropriate for enabling the completed package 70 to be hung via a peg or hook, from a retail display shelf. Depending upon the characteristics of the particular materials from which sleeve 10 and sheet 60 are fabricated, the act of die cutting hole 62 may serve to press onto or microweld the layers of sleeve 10 to the sides of sheet 60 , proximate to hole 62 , so that the edges of sleeve 10 that define hole 62 are not loose, but more or less affixed to sheet 60 .
A further vertical weld 64 may be provided if desired, to prevent sheet 60 from migrating laterally, and to obviate the need for sheet 60 to extend across the entire width of the top of sleeve 10 . Alternatively, sheet 60 may be made to have a width approximately equal to the width of sleeve 10 .
Package 70 has the advantage of providing for the packaging of a plurality of like articles in a compact and economic manner, while at the same time displaying a single representative one of the articles in a complete manner for unencumbered visual inspection. Furthermore, package 70 enables indicia such as product information to be provided in a manner which is not interfered with by the articles being packaged.
While in preferred embodiments of the invention, in the package, the articles packaged are all identical or substantially so, in alternative embodiments of the invention, one or more of the articles may be non-identical.
FIGS. 9–11 illustrate components and an assembly thereof, for a package according to an alternative embodiment of the invention. In this embodiment the package may be formed from two sheets 102 , 104 of plastic (or similar) transparent material. The articles being packaged, and the indicia bearing sheets of the prior embodiments have been omitted from the illustrations, but are understood to be present in finished packages fabricated in accordance with the description hereinafter.
Sheets 102 , 104 preferably have the same width, but sheet 102 is longer than sheet 104 . Sheet 102 is folded upon itself, to form legs 106 , 108 , while sheet 104 is folded about sheet 102 , to form legs 110 , 112 . Thereafter, seams (or closure lines) 114 , 116 , 118 and 120 are formed by heat, ultrasonic or RF (radio frequency) waves, through all layers of sheets 102 , 104 , to form three long inner chambers across, between legs 106 and 108 ; three outer short chambers across between legs 106 and 110 ; and three short outer chambers across between legs 108 and 112 . For example, edges 122 , 124 and 126 define the mouths of the three short chambers on the upper side of package 100 , as seen in FIG. 9 .
In the embodiment of FIGS. 9–11 , the outer sheet 104 is folded about inner sheet 102 in such a manner that the free edges of legs 110 , 112 of sheet 104 are the same distance from the fold 111 . In alternative embodiments, sheet 104 may be shifted so that the free edges of legs 110 , 112 are at different distances from the fold. Furthermore, while in the embodiment of FIGS. 9–11 , three sets of three chambers extending across the width of package 100 are shown, it is to be understood that one of the seams (e.g., 118 ) may be omitted, to provide for two chambers extending across, or that more seams may be provided, without departing from the scope of the invention.
One or more articles, such as drills 122 ( FIG. 10 ) may be inserted into one or more of the inner chambers between legs 106 and 108 , preferably in the manner described with respect to the previously described embodiments, wherein a plurality of like articles are placed in one or two of the long chambers, while a one or two exemplary articles are placed by themselves in a separate one of the chambers. For example, a package constructed according to FIGS. 9–11 may have in one long chamber a group of several examples of a particular style or model of article; in another long chamber, a group of several examples of another particular style or model of article, and in a third long chamber, one example of each. Thereafter, a further seam (not shown) may be placed across the entire width (or some lesser part thereof) of the aligned free edges of legs 106 , 108 , to capture the articles received in the chambers. Indicia bearing cards may be placed in one or more of the short chambers formed between legs 106 , 110 , and 108 , 112 , respectively, while preferably not in the short chambers adjacent to the long chamber containing the single (or small number) of examples of the groups of articles enclosed in the other long chambers. FIG. 22 illustrates an assembled version of a package 100 according to the embodiment of FIGS. 9–11 , but with the articles and indicia bearing sheets omitted for clarity. Once the articles (not shown) have been Inserted into the various chambers, a permanent seal 152 is provided (analogous to seal 52 of the embodiment of FIGS. 1–8 ), between legs 106 , 108 (see FIGS. 9–11 ), to capture the articles in the respective chambers. A further permanent seal may also be provided across the tops of legs 106 , 108 . Similar permanent welds (not shown) will be provided as appropriate in the embodiments of FIGS. 12–21 herein. In alternative embodiments, sheet 104 (or the corresponding separate outer layer sheets of the subsequently described embodiments) may have a width that is less than the width of sheet 102 (or the corresponding separate inner layer sheets of the subsequently described embodiments) to define a fewer number of outer chambers, than of inner chambers. Such an embodiment is illustrated in unassembled form in FIG. 21 .
FIGS. 23 and 24 illustrate a further embodiment of the invention, wherein the package 500 (in which the packaged articles have been omitted to facilitate illustration), similar to the embodiment of FIGS. 1–8 . has three vertical welds 502 , 504 and 506 , to form two outer chambers on the front two outer chambers on the back, and two inner chambers. Weld 504 , being substantially closer to weld 502 than to weld 504 , creates two outer chambers that have widths substantially less than the other two outer chambers, and one inner chamber that has a width that is substantially less than the other inner chamber, to facilitate the packaging of a quantity of articles in the larger inner chamber, and an indica bearing card or cards, in the two larger outer chambers, with a smaller number of articles, or even a single article (of the same type as in the larger inner chamber) in the smaller inner chamber, for facilitating inspection and display of the articles. Package 500 may be formed from a sandwich of four sheets 510 , 512 , 514 , 516 (as shown in solid lines in FIG. 24 , similar to the embodiment of FIGS. 18 and 19 ), wherein the outer sheets 510 , 516 are “shorter”than inner sheets 512 , 514 , Alternatively, package 500 may be formed by one or two folded over sheets, wherein sheets 510 , 516 may be the front and rear faces of a single folded-over sheet (as indicated by the broken lines in FIG. 24 ), and/or sheets 512 , 514 may be the front and rear faces of a single folded-over sheet(also as indicated by the broken lines in FIG. 24 ) similar to the embodiments of FIGS. 11 , 14 or 17 . Welds 502 , 504 and 506 preferably will join all four layers. While horizontal weld 518 will join only the innermost two layers (after insertion of the articles, not shown), being located above the upper edges (e.g., edge 520 of layer/sheet 5 l 0 of the outermost layers of package 500 . While the embodiment of FIGS. 23 and 24 has only two inner chambers, it is to be understood that in an alternative embodiment (similar to FIGS. 18 and 19 ), a wider package, having a further vertical weld, may be provided, of whatever desired width, so long as there is an inner chamber having a width substantially less than any of the other inner chambers, without departing from the scope of the present invention.
In the embodiments shown in FIGS. 9–20 , the inner and outer chambers all have approximately the same width, due to the substantially equidistant spacing between the longitudinal seams. However, it is understood that the spacing between the seams may be varied so that, for example, one inner chamber is substantially wider or narrower than the other(s) of the inner chambers, again for purposes of providing one example of an article being packaged set off from a group of others of the same article, for permitting thorough inspection of the individually set-off article.
FIGS. 12 — 14 illustrate another alternative embodiment of the invention, wherein a package similar to that of FIGS. 9–11 is formed from three sheets of plastic material. Package 200 is formed from sheets 202 , 204 and folded sheet 206 . Sheets 202 , 204 are joined together along their respective bottom edges at seam 208 , as shown in FIGS. 12 and 14 , and then sheet 206 is folded about the bottom seam of sheets 202 , 204 , to form legs 210 , 212 . Vertical seams 214 , 216 , 218 and 220 are formed, in the same manner as in the embodiment of FIGS. 9–11 . Again, there are three long chambers formed, by seams 214 , 216 , 218 and 220 , between sheets 202 and 204 , and three short sheets across, between sheet 202 and leg 210 , and between sheet 204 and leg 212 . Placement of the articles to be packaged, and the indicia bearing cards, may be accomplished in the same varieties of ways, as described with respect to the previously-described embodiments. Again, a greater or lesser number of “vertical” seams may be used, to make greater or fewer numbers of chambers extending across the width of the package.
A further alternative embodiment is shown in FIGS. 15–17 , wherein package 300 is formed from folded sheet 302 , and sheets 304 , 306 . Sheet 302 is folded at fold 308 , to form legs 310 , 312 . Then sheets 304 , 306 are aligned over legs 310 , 312 as shown. Sheets 304 , 306 are joined together along fold 308 , to form seam 314 . Vertical seams 316 , 318 , 320 and 322 are then created, to form long chambers between legs 310 , 312 , and to form short chambers between leg 310 and sheet 304 , and between leg 312 and sheet 306 . Placement of the articles to be packaged, and the indicia bearing cards, may be accomplished in the same varieties of ways, as described with respect to the previously-described embodiments. Again, a greater or lesser number of “vertical” seams may be used, to make greater or fewer numbers of chambers extending across the width of the package.
A still further alternative embodiment of the invention is illustrated in FIGS. 18–20 . Four sheets 402 , 404 , 406 and 408 are provided, which are arranged in overlying fashion as shown in FIGS. 18 and 20 . The sheets are then attached to one another by one of the methods previously described, to form seams 410 , 412 , 414 , 416 and 418 , again to form long chambers between sheets 404 and 406 , and short chambers between sheets 402 , 404 and between sheets 406 , 408 . Placement of the articles to be packaged, and the indicia bearing cards, may be accomplished in the same varieties of ways, as described with respect to the previously-described embodiments. Again, a greater or lesser number of “vertical” seams may be used, to make greater or fewer numbers of chambers extending across the width of the package.
In the embodiments of FIGS. 9–20 , the sheets that make up the inner and outer layers of the packages are preferably fabricated from a suitable, sealable plastic material, that may be heat, ultrasonic or RF sealed, and which may be transparent, translucent or, at least in places opaque. The sheets may be fabricated from material upon which indicia may be printed.
The foregoing description and drawings merely explain and illustrate the invention, and the invention is not limited thereto, except as those skilled in the art who have the present disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention. | A package for like articles, especially elongated articles, such as drill bits and the like, is provided with a plurality of compartments or sectioned off regions, for the containment of an individual article for substantially unfettered visual inspection; for the containment of a further plurality of articles identical to the exposed visual article, and for indicia as required by the manufacturer and/or required by law. The package is configured to be presented in a hanging manner from retail display shelving. | 1 |
STATEMENT REGARDING FEDERAL FUNDING
This invention was made under U.S. Government Contract No. HR0011-09-C-0126. The U.S. Government has certain rights in this invention.
CROSS-REFERENCE TO RELATED APPLICATIONS
None.
TECHNICAL FIELD
This disclosure relates to transistors and methods of encapsulation and manufacture thereof.
BACKGROUND
High frequency active circuits, designed to operate at a frequency above 50 GHz, may be vulnerable to damage for a number of reasons. Such circuits may include features with extremely small physical dimensions, such as a few nanometers, that may be fragile, especially in areas around transistor gates. In addition, interconnects and passive components, such as capacitors and thin-film resistors, on a front-side of a circuit may be sensitive to scratches. Therefore, such circuits are at risk of damage when handled during packaging and assembly. Also, the front-side of the circuit may be exposed to humidity and other environmental conditions that may cause performance degradation or accelerate failure of active components.
Encapsulation, or passivation, has been used to provide some physical protection for active areas, interconnects and passive components on the front-sides of micro-electronic chips, using a layer or coating of a material having a higher dielectric constant than air. Examples of dielectric materials used for this purpose include BCB (benzocyclobutene), spin-on glass and polyimide. The protective dielectric material can also be used to provide mechanical support for multi-layer interconnects, allowing additional flexibility in the design of the circuit. However, the presence of dielectric material around gates of components of the circuit causes parasitic capacitance to increase. Parasitic capacitance can cause a significant degradation in the performance of the circuit, particularly at high frequencies, potentially affecting one or more of gain, frequency drift, noise, output power and power-added efficiency. For example, a GaN (gallium nitride) amplifier encapsulated with BCB can show a deterioration of approximately 1.5 dB in small signal gain and a shift in operational frequency of 10-15%, when compared with an unencapsulated amplifier that is otherwise identical. Such decreased performance can occur even where a low-loss dielectric material is used for encapsulation.
Therefore, the protection and flexibility provided by conventional methods is offset by a decrease in the performance of the circuit. In low frequency circuits, operating below 30 GHz, the benefits may outweigh the degradation in performance. However, at higher frequencies, above 30 GHz, the reduction in gain, output power and efficiency of the circuit can be problematical. Hence, the usefulness of conventional dielectric encapsulation and passivation protection methods for high frequency circuits is limited.
SUMMARY
Embodiments of the present disclosure may include a semiconductor device including a substrate and one or more transistors mounted on said substrate, each of said one or more transistors having a respective gate terminal. Two or more layers of dielectric material encapsulate a front side of said one or more transistors, at least one of said two or more layers of dielectric material having one or more cavities. The gate terminal of each of said one or more transistors is located within one of said one or more cavities, separated from said at least one layer of dielectric material.
Such a semiconductor device may include two or more interconnects, where a first one of said interconnects is supported by a first one of said layers of dielectric material and a second one of said interconnects being supported by a second one of said layers of dielectric material.
The one or more transistors may include a gallium nitride high electron mobility transistor.
In some embodiments, the semiconductor device may form part of a device such as a power amplifier, low noise amplifier, mixer, switch, phase-shifter or variable attenuator. Alternatively, or additionally, the semiconductor device may form part of a submillimeter-wave circuit or mixed signal circuit.
In another embodiment, a semiconductor device includes a substrate and one or more gallium nitride high electron mobility transistors mounted on said substrate, each of said one or more transistors having a respective gate terminal. One or more layers of dielectric material encapsulate a front side of said one or more transistors, at least one of said one or more layers of dielectric material having one or more cavities. The gate terminal of each of said one or more transistors is located within a respective one of said one or more cavities and separated from said at least one layer of dielectric material.
In other embodiments, a device such as a power amplifier, low noise amplifier, mixer, switch, phase-shifter or variable attenuator or a circuit, such as a sub-millimeter wave circuit or a mixed signal circuit, includes said semiconductor device.
In yet another embodiment, a method of encapsulating a semiconductor device includes mounting one or more transistors on a substrate, each of said one or more transistors having a respective gate terminal, applying two or more layers of dielectric material encapsulating a front side of said one or more transistors, and forming one or more cavities in at least one of said two or more layers of dielectric material, where said one or more cavities are located around a gate terminal of said one or more transistors to separate said gate terminal from said two or more layers of dielectric material.
In such a method, said forming one or more cavities might include, before applying a first one of said two or more layers of dielectric material, applying a layer of sacrificial material over active areas of said one or more transistors, and after applying said two or more layers of dielectric material, etching said layers of dielectric material to provide access to said layer of sacrificial material, and removing said layer of sacrificial material.
In certain embodiments, the method further includes, after applying a first one of said two or more layers of dielectric material and before applying a second one of said two or more layers of dielectric material, forming one or more interconnects supported by said first layer of dielectric material and, optionally, may further include, after applying a second one of said two or more layers of dielectric material, forming one or more interconnects supported by said second layer of dielectric material. In an example where interconnects are supported by the first and second layers of dielectric material, forming said one or more interconnects supported by said first layer of dielectric material may include dry-etching said first layer of dielectric material, and forming said one or more interconnects supported by said second layer of dielectric material may include photo-etching said second layer of dielectric material.
In a further embodiment, a method of encapsulating a semiconductor device includes mounting one or more gallium nitride high electron mobility transistors on a substrate, each of said one or more transistors having a respective gate terminal. One or more layers of dielectric material are applied to encapsulate, or passivate, a front side of said one or more transistors. Then, one or more cavities in at least one of said one or more layers of dielectric material, where said one or more cavities are located around a gate terminal of said one or more transistors to separate said gate terminal from said one or more layers of dielectric material.
These and other features and advantages will become further apparent from the detailed description of example embodiments that follows and the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a device according to an embodiment;
FIG. 2 is a flowchart of an encapsulation method for use in manufacture of the device of FIG. 1 ;
FIGS. 3 to 8 depict stages in the encapsulation of the device of FIG. 1 using the method shown in FIG. 2 ;
FIG. 9 is a graph comparing DC characteristics of a GaN HEMT that has been encapsulated according to an embodiment and an unencapsulated GaN HEMT;
FIG. 10 is a graph comparing RF characteristics of a GaN HEMT that has been encapsulated according to an embodiment and an unencapsulated GaN HEMT; and
FIG. 11 depicts an encapsulated semiconductor device according to another embodiment.
DETAILED DESCRIPTION
In the figures and the following description, numerals indicate various features, like numerals referring to like features throughout both the drawings and description.
FIG. 1 depicts a device 1 , such as an IC (integrated circuit) chip according to an embodiment. In this particular example, the device 1 includes at least two transistors 2 a , 2 b , of which the respective gate terminals 3 a , 3 b , source terminals 4 a , 4 b and drain terminals 5 a , 5 b are shown, mounted on a substrate 6 . For example, the first transistor 2 a may be a D-mode (depletion mode) GaN HEMT and the second transistor 2 b may be an E-mode (enhancement mode) GaN HEMT, while the substrate 6 is formed of SiC (silicon carbide).
The front-side of the transistors 2 a , 2 b are encapsulated with at least one layer of dielectric material. In this particular example, three dielectric layers 7 , 8 , 9 are present. In addition to providing physical protection for the front-sides of the transistors 2 a , 2 b , the dielectric layers 7 , 8 , 9 can also be used provide mechanical support for metal interconnects 10 a , 10 b , 10 c , 11 a , 11 b , 12 at one or more levels within the device 1 . In the example embodiment depicted in FIG. 1 , the dielectric layers 7 , 8 , 9 are used to support interconnects 10 a , 10 b , 10 c , 11 a , 11 b , 12 at three different levels in the device 1 . The provision of interconnects at multiple levels can allow scaling, so that the overall physical dimensions of the device 1 can be made relatively small.
The active areas of the transistors 2 a , 2 b are separated from the material of the dielectric layers 7 , 8 , 9 . In this example, a cavity 13 a , 13 b is provided in a first one of the dielectric layers 7 to provide such separation, by forming an “air-box” around the gate terminals 3 a , 3 b of the individual transistors 2 a , 2 b . Since the gate terminals 3 a , 3 b are separated from the dielectric layers 7 , 8 , 9 , parasitic capacitance between the gate terminals 3 a , 3 b and the source terminals 4 a , 4 b and/or between the gate terminals 3 a , 3 b and the drain terminals 5 a , 5 b of the respective transistors 2 a , 2 b can be reduced, when compared with encapsulated devices without cavities.
An encapsulation method for use in manufacturing the device 1 will now be described with reference to the flowchart of FIG. 2 and to FIGS. 3 to 7 , beginning at step s 0 . The transistors 2 a , 2 b are provided on a SiC wafer 6 ′ (step s 1 ). An example of a method of fabricating GaN HEMTs is disclosed in K. Shinohara et al., “ Scaling of GaN HEMTs and Schottky Diodes for Submillimeter - Wave MMIC Applications ”, IEEE Transactions of Electron Devices, October 2013, the disclosure of which is incorporated herein by reference in its entirety.
The active areas of the transistors 2 a , 2 b are coated with a layer 14 of sacrificial material (step s 2 ), as shown in FIG. 3 . In this example, the sacrificial layer 14 is formed of a photo-resist, such as PMGI (polymethylglutarimide), spun-coated on the substrate 6 and having a thickness of approximately 2 microns.
The first dielectric layer 7 is then applied over the front-side of the transistors 2 a , 2 b , covering the sacrificial layer 14 (step s 3 ). In this particular example, the first dielectric layer 7 is formed of BCB and deposited using spin-on coating.
The first dielectric layer 7 is then patterned and etched (step s 4 ) to provide vias 15 a , 15 b , 16 a , 16 b , shown in FIG. 4 , for example using a RIE (reactive-ion etching) tool. A metallization process is then used to form a first set of interconnects 10 a , 10 b , 10 c by partially filling those vias 15 a , 15 b , 16 a , 16 b (step s 5 ), as shown in FIG. 5 . In this particular example, the first dielectric layer is a BCB coating of approximately 3 microns in thickness, deposited using spin-coating, and dry etched to provide the vias 15 a , 15 b , 16 a , 16 b and the interconnects 10 a , 10 b , 10 c are formed by Au (gold) metallization.
Where the further dielectric layers are to be added to the device, for example, to provide interconnects at more levels (step s 6 ), the steps of applying and etching a dielectric layer 8 , 9 (steps s 4 and s 5 ) and forming interconnects 11 a , 11 b , 12 (step s 6 ) is repeated for each further dielectric layer 8 , 9 . In this particular example, the further dielectric layers 8 , 9 are provided in the form of spin-on BCB coatings of approximately 3 microns in thickness.
Each further dielectric layers 8 , 9 is, in turn, deposited, cured, patterned and etched, in turn, to form further vias, 17 a , 17 b , 18 (steps s 4 and s 5 ). Since tolerances for the positioning of the interconnects 11 a , 11 b , 12 in the further dielectric layers 8 , 9 is greater than the tolerance for the position of the interconnects 10 in the first dielectric layer 7 , photo-etching may be used to define the vias 17 a , 17 b , 18 instead of dry-etching in step s 5 . Further interconnects 11 a , 11 b , 12 are then formed using a process such as sputtering and electroplating (step s 6 ). FIG. 6 depicts the device 1 following the application of second and third dielectric layers 8 , 9 and the formation of the further interconnects 11 , 12 thereon.
After the required number of dielectric layers 7 , 8 , 9 and interconnects 10 , 11 , 12 have been formed (step s 6 ), the wafer 6 ′ may then be thinned to form the substrate 6 (step s 7 ). In this particular example, the wafer 6 ′ is thinned to a thickness of 50 microns. Also, if required, backside vias (not shown) can be formed through the wafer 6 ′ at this stage.
The cavities 13 a , 13 b are then formed by removing the layer 14 of sacrificial material covering the active areas of the transistors 2 a , 2 b (step s 8 ), to complete the encapsulation method (step s 9 ). In this particular example, a hard mask (not shown) is placed over the device 1 and vias 19 a , 19 b , shown in FIGS. 7 and 8 , are formed in the dielectric layers 7 , 8 , 9 using a dry-etching technique such as RIE, to provide access to the layer 14 of sacrificial material covering the active areas. The layer 14 of sacrificial material is then removed using a developer, solvent or other chemical formulation, to form the cavities 13 a , 13 b around the gate terminals 3 a , 3 b , to produce the device 1 as shown in FIGS. 1 and 8 , where FIG. 8 shows a cross-section of the device through the vias 19 a , 19 b.
FIGS. 9 and 10 show DC and RF characteristics respectively, for a GaN HEMT with multi-level interconnects such as the transistor 2 a in FIG. 1 . FIG. 9 is a graph showing variation of the transductance g m of the transistor 2 a and the current I ds between the drain terminal 5 a and the source terminal 4 a against the voltage V gs between the gate terminal 3 a and the source terminal 4 a for an example where the gate length L gd is 20 nm, the gate-to-source overlap L gs is 30 nm, the gate-to-drain overlap L gd is 90 nm and the voltage V ds between the drain terminal 5 a and the source terminal 4 a is 4.0 V. FIG. 10 is a graph showing the maximum stable gain (MSG) and unilateral gain (U g ) of the same GaN HEMT structure at radio frequencies, where the voltage V ds between the drain terminal 5 a and the source terminal 4 a is 5.0 V and the voltage V gs between the gate terminal 3 a and the source terminal 4 a is −0.75 V.
In both FIGS. 9 and 10 , the values for the GaN HEMT, before encapsulation, are indicated by a solid line, while the values for the GaN HEMT after encapsulation with a cavity 13 a are indicated by open circles. As shown by FIGS. 9 and 10 , the changes in the DC and RF characteristics of the GaN HEMT caused by encapsulation may be insignificant. In particular, in the example shown in FIG. 9 , the differences in cut-off frequency f T and maximum oscillation frequency f max between the encapsulated GaN HEMT and the unencapsulated GaN HEMT appear to be negligible. Hence, in this example, the performance of the GaN HEMT is largely unaffected by multi-layer encapsulation by the method of FIG. 2 , where the presence of the cavity 13 a prevents a significant increase in the parasitic capacitances of the gate terminal 3 a.
FIG. 11 depicts a semiconductor device 20 according to another embodiment in which two GaN HEMTs 2 a , 2 b are encapsulated by a single dielectric layer 7 and interconnects 10 a , 10 b , 10 c are supported by the single dielectric layer 7 at one level. Such a semiconductor device 20 may be provided by a method as shown in FIG. 2 , without repetition of steps s 4 , s 5 and s 6 discussed hereinabove.
Embodiments of the present disclosure may provide methods for providing at least some of the advantages of dielectric encapsulation while reducing, or even avoiding, the performance degradation associated with conventional encapsulation techniques. Where multi-layer encapsulation is used, the dielectric layers 7 , 8 , 9 can be used to support interconnects 10 a , 10 b , 10 c , 11 a , 11 b , 12 at multiple levels, facilitating scaling of devices 1 and increasing multi-functionality and improving flexibility when interconnecting between multiple devices 1 . Where the overall size of the device 1 is reduced, the cost of the device may also decrease.
Embodiments of the present disclosure may be particularly beneficial in active devices operating at high speed or at high frequencies, above 50 GHz, such as G-band frequencies (110-300 GHz), where performance degradation due to parasitic capacitances may be particularly marked. For example, the use of highly-scaled GaN HEMTs in submillimeter-wave and mixed signal circuits, power amplifiers, low noise amplifiers, mixers, switches, phase shifters, variable attenuators and so on, may be facilitated by using embodiments of the encapsulation method.
Encapsulation methods according to particular embodiments may be compatible with GaN T2, T3 and T4 processes.
In the embodiments described above, the sensitive active areas of the transistors 2 a , 2 b and at least some of the interconnects 10 a , 10 b , 10 c , 11 a , 11 b , 12 are protected by one or more dielectric layers 7 , 8 , 9 . Protected chips are easier to handle during mounting and assembly of electronic devices, for example, where tweezers of vacuum wands are used to hold and manipulate the chips.
Also, depending on the details and type of the dielectric encapsulation, the embodiments can provide a hermetic or near-hermetic environment for the active areas of the transistors 2 a , 2 b , protecting the transistors 2 a , 2 b from some adverse environmental conditions. This can improve the long-term reliability of the device 1 and, also, allows greater freedom in a next level of packaging of the device 1 .
The foregoing description of embodiments is presented for the purposes of illustration only. It is not intended to be exhaustive or to limit the disclosure to the precise form of the examples disclosed. For example, while the example embodiments disclosed with reference to FIGS. 1 and 3 to 8 and to FIG. 11 have two GaN HEMT transistors 2 a , 2 b , embodiments may have other numbers, or types, of active devices.
While FIGS. 1 and 11 depict embodiments in which transistors 2 a , 2 b are located within respective cavities 13 a , 13 b in a first dielectric layer 7 , other embodiments may be envisaged in which more than one transistor is located within one cavity and/or where a cavity extends into more than one dielectric layer 7 , 8 , 9 .
FIGS. 1 and 11 depict embodiments in which three dielectric layers 7 , 8 , 9 and one dielectric layer 7 are provided respectively, with interconnects 10 a , 10 b , 10 c , 11 a , 11 b , 12 provided on a corresponding number of levels. Other embodiments may have different numbers of dielectric layers and/or levels of interconnects.
The example embodiments shown in FIGS. 1 and 11 have a SiC substrate, gold interconnects and one or more dielectric layers 7 , 8 , 9 formed of BCB. However, in other embodiments, alternative materials may be used for some or all of these components. Examples of other suitable materials for the one or more dielectric layers 7 , 8 , 9 include spin-on glass, silicon nitride (SiN), polyimide, and so on, while suitable materials for forming some or all of the interconnects include copper. Further, other techniques may be used to deposit and/or define the layer 14 of sacrificial material and the one or more dielectric layers 7 , 8 , 9 than those discussed above in regard to FIG. 2 , such as plasma-enhanced chemical vapor deposition (PECVD).
Other modifications and variations to the above embodiments will be apparent to persons skilled in the art, and the method steps described above might be interchangeable with other steps to achieve the same result. It is intended that the scope of the disclosure be interpreted with reference to the claims appended hereto and their equivalents.
Reference to an element in the singular hereinabove is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more”. Moreover, 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 accompanying 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 . . . ”. | A semiconductor device comprises one or more transistors and two or more layers of dielectric material encapsulating a front side of said one or more transistors. The gate of each of said one or more transistors is located within a cavity, or air-box, in at least one of the dielectric layers, so that the gate terminal is physically separated from said dielectric material. Such an arrangement may reduce parasitic capacitance. In another arrangement, a semiconductor device comprises one or more gallium nitride high electron mobility transistors and one or more dielectric layers encapsulating a front side of said one or more transistors, wherein the gate terminal of each of said one or more transistors is located within a cavity in at least one of the one or more dielectric layers, separated from said dielectric material. | 7 |
FIELD OF THE INVENTION
The present invention relates to a method and apparatus for recovering metal values from particulate metal-containing dust, and more particularly to a method and apparatus for recovering metal from electric arc furnace dust.
BACKGROUND OF THE INVENTION
Rotary Hearth Furnace processes such as the Midrex FASTMET™ Process, INMETCO process, and Maumee process, and Rotary Kiln processes such as Horse Head and BUS Waelz Kiln, have been developed, marketed, and sold as methods of recovering iron units, zinc and other valuable metallics from large integrated steel mill waste streams. Economical plant capacity for these processes is in the range of 100,000 to 200,000 tonnes of waste processed per year. Mini mills, based on Electric Arc Furnace technology, are typically smaller in capacity than integrated steels mills and produce significantly less waste, ranging from 5,000 to 30,000 tonnes per year. The specific dust waste from Electric Arc Furnace (EAF) operations has been classified by the US Environmental Protection Agency (US EPA) as K061, a hazardous waste requiring special handling, inventory control and approved disposal by US EPA. These special handling requirements and implied liabilities make operation of a large capacity centralized EAF Dust Processing facility cumbersome and undesirable. High Temperature Metals Recovery (HTMR) processing of wastes classified as K061 has been identified by US EPA as the preferred method of treating and delisting.
It is therefore desirable to provide an economical method of thermal treatment of as-generated mini-mill waste located at the site at which such waste is produced.
In 1998, Midrex International BV received U.S. Pat. No. 5,730,775, that teaches an improved method known by the trade name or trademark of FASTMET™, and apparatus for producing direct reduced iron from dry iron oxide and carbon compacts that are layered no more than two layers deep onto a rotary hearth, and are metallized by heating the compacts to temperatures of approximately 1316° to 1427° C., for a short time period. For a general understanding of the recent art, U.S. Pat. No. 5,730,775 is herein incorporated by reference.
In existing rotary hearth and rotary kiln HTMR processes, most of the capital cost is associated with feed preparation equipment necessary to feed the processing furnace, with the fabrication and erection of the furnace itself, and with product handling equipment.
SUMMARY OF THE INVENTION
The invention provides a method and apparatus for recovering principally iron and zinc values from EAF dust. The method of recovering metal values from metal-containing dust, comprises the steps of:
a. mixing metal-containing dust and carbonaceous fines to form a particulate mixture;
b. heating the metal-containing dust and carbonaceous fines mixture on a moving bed horizontal tunnel furnace at a sufficient temperature and for a sufficient time to reduce and release volatile metals and alkali metals therefrom along with gaseous products;
c. collecting the released metals and gases, and reoxidizing the metals; and
d. separating the metal values from the gases and removing the metal values, principally zinc and iron, from the process as product.
The furnace is sealed to prevent the intrusion of ambient air. A baghouse is provided to collect the volatile metals.
The invented process feeds a simple “as is” mixture of EAF dust and carbon fines (coal dust, charcoal, pet coke. etc.) through a feed leg onto a horizontal stroke conveyor. Motion of the conveyor controls the feed rate and distributes the feed evenly across the conveyor pan. Since the pan is not a “moving hearth” the feed area is always cold,. i.e., at ambient temperature. This eliminates the complicated and expensive feed and leveling systems associated with rotary hearth processes.
OBJECTS OF THE INVENTION
The principal object of the present invention is to provide an improved method of achieving rapid and efficient reduction of metal oxide fines and recovery of metal values therefrom.
Another object of the invention is to provide a simple, low-cost method and apparatus for the processing of EAF dust.
Another object of the invention is to provide a reduction furnace apparatus which can be installed on site, or can be fully portable.
A further object of the invention is to provide a fines reduction furnace capable of operating at variable speed
Another object of the invention is to provide means for recovering useable zinc oxide from EAF dust.
Another object of the invention is to provide a method which requires no hazardous waste water treatment.
Another object of the invention is to provide a method which produces no hazardous solid waste.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects will become more readily apparent by referring to the following detailed description and the appended drawings in which:
FIG. 1 is a schematic diagram of the invented process.
FIG. 2 is a schematic top view of the furnace, feed, and discharge.
FIG. 3 is side view of the invented processing furnace mounted on a truck.
FIG. 4 is side view of the filter equipment of the invention mounted on a truck.
FIG. 5 is a side view of an EAF Dust silo or bin mounted on a truck.
FIG. 6 is a side view of a pulverized reductant bin mounted on a truck.
FIG. 7 is a side view of the invented tunnel furnace and associated equipment and supports.
FIG. 8 is a cross-section of the tunnel kiln taken along line 8 — 8 of FIG. 7 .
FIG. 9 is an enlarged detail view of the portion of FIG. 7 indicated by oval 90 .
DETAILED DESCRIPTION
As shown in FIG. 1 an elongated reduction furnace 10 has a charging or feed end 12 and a discharge end 14 . A feed hopper 16 communicates with the charging end 12 of the furnace which can advantageously be by a seal leg 18 controlled by a sliding gate 20 . A horizontal stroke conveyor 22 is positioned in the lower part of the furnace to move the feed material from the charging end through the furnace at a controlled rate. Burners 24 are positioned as shown in the side wall of the reduction furnace to provide the necessary heat for the reduction process. A flue gas offtake 26 is provided in the top wall of the refractory lined furnace.
The furnace 10 is a tunnel furnace and has a suitable side seal 28 such as a flexible connector which provides a seal between the sides of the furnace and the conveyor 22 .
Product is discharged from the furnace into a transport vessel 92 , the discharge of which product may be controlled by a slide gate 94 .
EAF dust is collected in bin 40 and fed to a mixing conveyor 42 along with pulverized reductant from bin 44 . The reductant is pulverized or powdered coal, petroleum coke, or charcoal.
Flue gas from offtake 26 has dilution air A provided thereto and the diluted flue gas moves through line 48 to a filter 50 . Particulates drop out from the filter which may be a bag filter and are collected in vessel 52 . The filtered diluted offgas may then be exhausted to the air through exhaust stack 54 .
The reduction furnace can not only be mounted on the ground as shown in FIGS. 1 and 7, but can be truck mounted as shown in FIG. 3 . The additional components of the process can also be truck mounted, ie, the offgas treating vessel comprising a bag filter 50 and a fan 56 shown in FIG. 4 and EAF silo or bin 40 A shown in FIG. 5 and reductant bin 44 A shown in FIG. 6 .
The speed of the material flowing through the furnace is controlled by thermocouple 88 .
The invention is a low cost plant specifically designed for efficient EAF Dust thermal processing. The invented reduction process utilizes a horizontal motion conveyor 22 in a high temperature tunnel furnace 10 for thermal processing of EAF Dust. The primary goal is recovery of high quality crude zinc oxide. Metallic iron product that is produced may be recycled to an EAF as injectable fines, or it may be briquetted in a briquetting facility, or it may be landfilled, depending on local requirements.
The horizontal conveyor 22 is shop fabricated and installed at the site with minimal foundations and field erection. The horizontal stroke conveyor transports the EAF dust and carbon mixture from the cold feed area through a heated “tunnel kiln” or furnace 10 maintained at 1100 to 1200° C. by a system of burners. Retention time in the heated zone is 10 to 20 minutes.
A thermocouple 88 located under the conveyor pan at the end of the heating zone monitors the temperature of the bottom layer of the dust and carbon mixture and maintains a setpoint by controlling by the frequency of the conveyor stroke. Since the action of the conveyor does not mix the dust mixture, monitoring the temperature of the bottom layer indicates when the reduction and volatile metals release is complete, which is when the lowermost part of the mixture reaches a temperature of about ˜1100° C., and this also protects the conveyor pan from damage due to overheating.
Volatile metals (zinc, lead, cadmium, etc.) and alkali metals (sodium and potassium) are released from the dust upon heating, are reoxidized in the flue gas, exhausted from the furnace with the flue gas, and captured by the bag filter. The volatile metals strip sulfur compounds from the flue gas and form metal sulfides that are also captured by the bag filter, thus controlling and limiting SO 2 emissions. The flue is quickly cooled from furnace temperatures (˜1150° C.) to acceptable bag filter inlet temperature by introducing dilution air (at about a 5:1 air to flue gas ratio). This quick cooling prevents formation of dioxin compounds. The fuel burners are low NO x by design and are operated with minimum excess oxygen to minimize NO x generation. No additional emission control devices are required to meet EPA requirements. The particulate captured by the bag filter is rich in zinc oxide (more than 70%) and is sold to zinc refiners as a valuable source of zinc.
Reduced iron product is discharged from the furnace, preferably into a sealed container 92 . When the container is full, the sliding gate 94 is closed, the container is removed and replaced with another. The reduced iron product collected in the container may be reintroduced by injectoin into the EAF, or briquetted and fed to the EAF with scrap, or in some cases simply disposed of in land fill. The filled container may be cooled by simply setting it aside under ambient conditions for 12 to 18 hours, or it may be more rapidly cooled by immersion in a water bath.
Plant equipment may be skid mounted for easy erection (and minimum engineering) on a simple, concrete slab foundation.
Bench scale testing has shown that reduction of EAF Dust and release of zinc is feasible under the conditions described by this process. The following table shows recovery of iron units from EAF dust in this process:
Sam-
ple
Description
Total Iron
Metallic Iron
% MET
% C
A
MET #2 Residue
52.72
41.55
78.8
2.13
B
MET Dust Mix
30.23
—
—
13.07
C
MET (10 min.) CSM
45.57
35.04
76.9
3.34
D
MET (12.5 min.) CSM
53.48
43.54
81.4
2.03
E
MET (15 min.) CSM
49.95
32.18
64.4
1.52
Notes:
A = 7.3 grams of mix heated at 1100° C. for 15 minutes
B is unheated mix-mixing ratio is 84% EAF Dust with 16% Charcoal (ground and dry)
C thru E9 grams of mix heated at 1150° C. Furnace Temperature
Alternative Embodiments
Alternatively the furnace and related equipment may be truck mounted on a series of trucks as shown in FIGS. 3 through 6, which are then connected with appropriate conduits.
Summary of the Achievement of the Objects of the Invention
From the foregoing, it is readily apparent that I have invented an improved method and apparatus for achieving rapid and efficient reduction of metal oxide fines and recovery of metal values therefrom; a simple, low-cost method and apparatus for the processing of EAF dust, which can be installed on site, or can be fully portable, a fines reduction furnace which is capable of operating at variable speed; which recovers useable zinc oxide from EAF dust; which requires no hazardous waste water treatment; and which produces no hazardous solid waste.
It is to be understood that the foregoing description and specific embodiments are merely illustrative of the best mode of the invention and the principles thereof, and that various modifications and additions may be made to the apparatus by those skilled in the art, without departing from the spirit and scope of this invention, which is therefore understood to be limited only by the scope of the appended claims. | An improved method and apparatus for recovering metal values from Electric Arc Furnace dust, particularly zinc and iron values, by mixing EAF dust and carbonaceous fines to form a particulate mixture; heating the mixture at a sufficient temperature and for a sufficient time to reduce and release volatile metals and alkali metals in a flue gas; collecting the released metals, and removing the metal values from the process as product. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a seal for a bearing that rotatably supports a shaft. The shaft extends through a housing opening of a housing element that limits, at least partially, a chamber containing a lubricant in form of a lubricating grease or oil. Between the lubricant-containing chamber and the bearing, there is provided a sealing ring that surrounds the shaft and is retained between the shaft and the housing element for protecting the bearing from the lubricant. The sealing ring forms, together with a limiting element, an annular gap.
2. Description of the Prior Art
The seals of the type descried above, are provided, e.g., on lubricant-receiving chambers or receptacles for gear units of, e.g., hand-held power tools. The sealing ring prevents the lubricant, which is provided in the associated gear housing, from directly contacting the bearing and from flowing through the bearing from the gear housing outwardly, e.g., into a motor housing.
European Patent EP 0 202 702 B1 discloses a seal for a shaft bearing and which includes a swivel ring connected with the shaft for a joint rotation therewith. The swivel ring forms a hub which extends radially outwardly and forms, together with a hub fixedly connected with the housing and extending from the housing opening radially inwardly, an annular gap. This annular gap has a labyrinth-shaped cross-section.
U.S. Pat. No. 5,876,126 discloses a shaft bearing seal that has a sealing disc retained on an outer ring of the bearing which is fixedly secured to the housing. The sealing disc forms, together with a shaft and a bearing inner ring press-fitted on the shaft, a labyrinth-shaped annular gap.
The drawback of the known shaft bearing seals consists in that despite the labyrinth-shaped annular gap, in particular at a vertical orientation of the shaft, the lubricant reaches the bearing and can leave the lubricant-receiving chamber through the bearing.
Such seals are not suitable for hand-held power tools which, e.g., are often used in overhead works and have the shaft oriented vertically for an extended time period in an operational or shut-down condition of the power tool when no lubricant should flow through the shaft bearing.
Accordingly, an object of the present invention is to provide a shaft bearing seal suitable for hand-held power tools and in which the above-mentioned drawback of the known shaft bearing seals is eliminated, and the bearing is better protected from the lubricant such as grease.
SUMMARY OF THE INVENTION
This and other objects of the present invention, which will become apparent hereinafter, are achieved according to the present invention by providing a shaft bearing seal of the type discussed above and in which the sealing ring has aeration recesses which connect the annular gap with the lubricant containing chamber. The aeration recesses permit to remove the lubricant, which penetrated in the annular gap during the operation or shut-down of the power tool as a result of a vertical orientation of the bearing, from the annular gap. To this end, a dynamic effect is used which is produced by a rotation of the sealing ring that limits the annular gap on one side, relative to another limitation that limits the annular gap on the second side. The sealing ring can be fixedly connected, e.g., with the shaft for joint rotation therewith, and the limiting element can be fixedly secured to the housing element or vice versa. The aeration recesses aerate the annular gap. The aeration of the annular gap during operation prevents development of underpressure in the annular gap that can cause an aspiration of lubricant in the annular gap or its retention there.
According to a particular advantageous embodiment of the present invention, the sealing ring is formed by an impeller-like disc connectable with the shaft for a joint rotation therewith, and the limiting element is fixedly connected with the housing element. During an operation, the sealing ring rotates together with the shaft, accelerating the lubricant accumulated on the sealing ring. Thereby, in particular with a suitable shape of the sealing ring, the lubricant can be particularly effectively forced out of the annular gap.
Advantageously, the annular gap is formed between a radially outer rotational surface of the sealing ring and the limiting element. This insures a maximum acceleration of the lubricant that accumulated on the sealing ring during operation. This further optimizes removal of the lubricant from the annular gap.
Advantageously, the aeration recesses open into the rotational surface of the sealing ring, which insures a particularly good aeration of the annular gap and, thus, an unobstructed delivery of the lubricant out of the annular gap.
Preferably, the aeration recesses are substantially identical and are spaced from each other by a same angular distance. This insures a uniform removal of the lubricant over the sealing ring circumference.
Advantageously, there are provided at least three aeration recesses. This permits to achieve a particularly high delivery output of the sealing ring with respect to the lubricant in the annular gap.
Preferably, the aeration recesses extend from a lubricant containing chamber side end surface of the sealing ring to a bearing-side end surface of the sealing ring. Thereby, the aeration of the annular gap takes place over the entire width of the rotational surface. In addition, thereby, even the region of the annular gap, which is limited by the bearing-side end surface of the sealing ring remote from the lubricant-containing chamber, is aerated.
It is further particular advantageous when the aeration recesses extend radially inwardly up to a virtual cylinder a diameter (dZ) of which is smaller than an outer diameter of an inner ring of the bearing. Thereby, the side of the bearing adjacent to the lubricant-containing chamber can be completely aerated in the region between the shaft-side inner ring of the bearing and the outer ring of the bearing fixed to the housing. In this region, because of the insufficient sealing, the lubricant exits from the lubricant exits from the lubricant-containing chamber. Complement aeration prevents underpressure in this region. Therefore, with a suitable shape of the sealing ring, in this region also, a substantially complete removal of the lubricant is possible.
Advantageously, the aeration recesses extend over from 70% to 95% of a sealing ring circumference, and an acceleration element is formed between each two adjacent aeration recesses. With this propeller-shaped design of the sealing ring a particularly high delivery output with respect to the annular gap is achieved.
It is advantageous when the acceleration element has a side surface adjacent to a rotational direction and inclined toward a bearing axis at an angle. This likewise increases the delivery output.
Advantageously, the acceleration element alternatively or in addition is inclined toward the bearing axis at the rotational surface of the sealing element, at an angle. In this way, the sealing ring forms, during an operation, a conical rotational body, and an improved lubricant delivery takes place over the circumference of the sealing ring.
The novel features of the present invention, which are considered as characteristic for the invention, are set forth in the appended claims. The invention itself, however, both as to its construction and its mode of operation, together with additional advantages and objects thereof, will be best understood from the following detailed description of preferred embodiments, when read with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings show:
FIG. 1 a partially cross-sectional view of a shaft bearing seal according to the present invention;
FIG. 2 a plan view of the sealing disc of the shaft bearing seal according to FIG. 1 ;
FIG. 3 a side view of the sealing disc according to FIG. 2 in direction of arrow III;
FIG. 4 a plan view of another embodiment of the sealing disc of the shaft bearing seal according to the present invention;
FIG. 5 a side view of the sealing disc according to FIG. 4 in direction of arrow V;
FIG. 6 a plan view of a further embodiment of the sealing disc of the shaft bearing seal according to the present invention; and
FIG. 7 a side view of the sealing disc according to FIG. 6 in direction of arrow VII.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a shaft bearing seal 2 which is provided on a grease-containing chamber 4 of a gear housing, not shown in detail, of a hand-held power tool, e.g., in form of a hammer drill or a screw driving tool. The shaft bearing seal 2 is provided on a bearing 6 that is retained in the housing opening 8 of a wall-shaped housing element 10 . The housing element 10 separates the grease-containing chamber 4 from an outer chamber 12 of a motor housing, not shown in detail.
The bearing 6 serves for supporting a shaft 14 for rotation about an axis A. The shaft 14 projects from the outer chamber 12 into the grease-receiving chamber 4 . The bearing 6 has an inner ring 16 which, e.g., is press fit-mounted on the shaft 14 for joint rotation therewith. The inner ring 16 is rotated relative an outer ring 20 of the bearing 6 by a ball-shaped bearing body 18 . The outer-ring 20 is held fixedly in the housing element 10 and is axially secured with a circlip 22 . Between the inner ring 16 and the outer ring 20 , there are provided sealing elements 24 .
On the shaft 14 , there is further provided a sealing disc 26 in form of an impeller-like disc that, e.g., is connected with shaft 14 by a press fit for joint rotation therewith. The sealing disc 26 is held, with respect to the axis A, at an axial height of a limiting element 28 that is formed by a collar section of the housing element 10 , which projects radially inwardly in the housing opening 8 . A circumferential rotational surface 32 , which is defined by radially outer surfaces of the sealing disc 26 , and the limiting element 28 form an annular gap 30 .
As shown in FIGS. 2-3 , the sealing disc 26 has three acceleration elements 33 which are separated from each other by aeration recesses 34 . The aeration recesses 34 extend over more than 90° of the rotational surface 32 . The acceleration elements 33 form radially outer circumferential surfaces 35 which define the rotational surface 32 .
Alternatively, the aeration recesses 34 can be formed by a multiplicity of smaller grooves which can be formed on the circumference of the sealing disc 26 (not shown). In each case, the rotational surface 32 is formed by the radially outer surfaces 36 of the sealing disc 26 which upon rotation of the sealing disc 26 in a direction D, form an outer cylindrical surface of the corresponding rotational body.
The aeration recesses 34 and thus, the acceleration elements 33 extend, as shown in FIG. 1 , over an entire width of the sealing disc 26 from a chamber-side end surface 36 adjacent to the grease-receiving chamber 4 to a bearing-side end surface 28 adjacent to the bearing 6 .
As shown in FIG. 1 , the aeration recesses 34 extend radially inwardly up to a common virtual cylinder Z having a diameter dZ. The diameter dZ is smaller than the outer diameter dR of the inner ring 16 of the bearing 6 .
When the respective hand-held power tool is operated or is shut down and the shaft 14 is so aligned that it extends, as shown in FIG. 4 , vertically, the grease can flow from the grease-receiving chamber 4 into the annular gap 30 between the sealing disc 26 and the limiting element 28 and through the annular gap 30 into an intermediate chamber 40 between the sealing disc 26 and the bearing 6 . As a result, the grease directly contacts the sealing elements 24 .
As soon as the shaft 14 begins to rotate about the axis A, the grease would be accelerated in the annular gap 30 and in the intermediate chamber 40 by the sealing disc 26 and would be transported from the annular gap 30 .
The aeration recesses 34 , which connect the grease-receiving chamber 4 with the annular gap 30 and the intermediate chamber 40 , insure that both the annular recess 30 and at least a region of the intermediate chamber 40 that extends over the sealing elements 24 , is adequately aerated. In this way, the built-up of an underpressure is prevented, and almost complete removal of grease, which accumulated on the sealing elements, is insured. At that, a grease cone 42 is formed that permanently adjoins the annular gap 30 but cannot penetrate thereinto as long as the sealing disc rotates.
FIGS. 4 through 7 show alternative embodiments of the sealing disc 26 , with the elements, which perform the same functions, all having the same reference numerals as in FIGS. 1-3 .
In the embodiment shown in FIGS. 4-5 , the acceleration elements 33 form, with respect to the axis A, an angle (α) on both side surfaces 44 aligned in the rotational direction D.
In the embodiment of FIGS. 6 and 7 , additionally, the radially outer circumferential surface 35 of the acceleration elements 33 forms, with respect to axis “A” an inclination angle (β), so that the sealing disc 26 forms, upon rotation in the rotational direction D, a conical rotational body, as shown with dash-dot lines.
Though the present invention was shown and described with references to the preferred embodiments, such are merely illustrative of the present invention and are not to be construed as a limitation thereof and various modifications of the present invention will be apparent to those skilled in the art. It is, therefore, not intended that the present invention be limited to the disclosed embodiments or details thereof, and the present invention includes all variations and/or alternative embodiments within the spirit and scope of the present invention as defined by the appended claims. | A seal ( 2 ) for a bearing ( 6 ) that rotatably supports a shaft ( 14 ) extending through a housing opening ( 8 ) of a housing element ( 10 ) that limits, at least partially, a lubricant-receiving chamber ( 4 ), includes a sealing ring ( 26 ) retainable between the housing element ( 10 ) and the shaft ( 14 ) and forming together with a limiting element ( 28 ) an annular gap ( 30 ), and having aeration recesses ( 34 ) which connect the annular gap ( 30 ) with the grease-containing chamber ( 4 ). | 5 |
FIELD
[0001] The disclosed embodiments generally relate to mobile terminals and more particularly to data management using mobile terminals.
BACKGROUND
[0002] Mobile terminals, or mobile (cellular) telephones, for mobile telecommunications systems like GSM, UMTS, D-AMPS and CDMA2000 have been used for many years now. In the older days, mobile terminals were used almost exclusively for voice communication with other mobile terminals or stationary telephones. More recently, the use of modern terminals has been broadened to include not just voice communication, but also various other services and applications such as www/wap browsing, video telephony, electronic messaging (e.g. SMS, MMS, email, instant messaging), digital image, audio or video recording, FM radio, music playback, electronic games, calendar/organizer/time planner, word processing, etc. Furthermore, the modern terminals have local connectivity abilities, such as Bluetooth, allowing the mobile terminals to communicate with a wide array of devices.
[0003] With the capabilities of modern mobile terminals, it is possible to record sound clips, using the microphone normally used during phone calls, and storing these sound clips for later use. However it is a problem that sound clips can not easily be recorded while the user is engaged in a phone call. One way to solve this is to allow the user to record the phone call in its entirety or parts thereof. However, there still remain drawbacks with flexibility of such functionality.
[0004] Also, there is a problem with keeping track of previous phone calls. It is previously known to keep a list of previously received and/or placed calls, where each entry has information about time, remote party, etc. However, if is still a problem for the user to know more details about each phone call, e.g. what was discussed.
[0005] Also, there is a problem with keeping track of contact records. contact records here relate to records of information stored in the mobile terminal regarding name, phone numbers, email addresses, etc. Users of mobile terminals store more and more contact records. This increases the difficulty of keeping track of who is who, which is made even more difficult if the user only stores contact names using first names.
[0006] Consequently, there is a need for an improved mobile communication terminal addressing the problems discussed above.
SUMMARY
[0007] In view of the above, an objective of the invention is to solve or at least reduce the problems discussed above.
[0008] Generally, the above objectives are achieved by the attached independent patent claims.
[0009] A first expression of a inventive aspect is a method for recording audio using a mobile communication terminal while a microphone connected to the mobile communication terminal provides audio data for an audio communication channel to a remote party, the method comprising: detecting a first user input indicating a private recording is to be started; stopping provision of audio data from the microphone to the audio communication channel; receiving an audio signal from the microphone; and recording the audio signal.
[0010] This allows a user to privately record audio from the microphone without the remote user hearing this. In other words, it allows the user to take private notes without bothering remote users.
[0011] The method may further comprise: detecting a second user input indicating the private recording is to be paused; pausing the recording of the audio signal; and reestablishing the provision of audio data from the microphone to the audio communication channel.
[0012] The detecting a first user input may involve detecting a first actuation of a user interface element and the detecting a second user input may involve detecting a second actuation of the user interface element.
[0013] The detecting a first user input may involve detecting a depression of a user interface element and the detecting a second user input may involve detecting a release of the user interface element.
[0014] The method may further comprise: detecting a third user input indicating the private recording is to be stopped; stopping the recording of the audio signal; and storing the recording of the audio signal in persistent memory.
[0015] A second expression of the first inventive aspect is a mobile communication terminal for recording audio while a microphone connected to the mobile communication terminal provides audio data for an audio communication channel to a remote party, the mobile communication terminal comprising a controller, wherein: the controller is configured to detect a first user input indicating a private recording is to be started; the controller is further configured to, as a response to the first user input, stop the provision of audio data from the microphone to the audio communication channel; the controller is further configured to receive an audio signal from a microphone; and the controller is further configured to, as a second response to the first user input, record the audio signal.
[0016] A third expression of the first inventive aspect is a computer program product comprising software instructions that, when executed in a mobile communication terminal, performs the method according to the first expression of the first inventive aspect.
[0017] A first expression of a second inventive aspect is a method for storing keywords using a mobile communication terminal while a user of the mobile communication terminal is in audio communication over a communication channel with a remote party, the method comprising: acquiring audio data related to the communication channel converting at least part of the audio data to text data; determining if the text data contains a keyword; if it is determined that the text data contains a keyword, storing the keyword associated with information regarding the remote party.
[0018] This allows the user to automatically have keywords associated with each call, alleviating remembering what was said in each call.
[0019] The determining if the text data may contain a keyword may involve comparing a candidate word of the text data against a list of words, the candidate word being determined to be a keyword if the candidate word is excluded in the list.
[0020] The list of words may be a list of words used for predictive text functionality used when entering text in the mobile communication terminal.
[0021] The determining if the text data contains a keyword may involve comparing a candidate word of the text data against a list of words, the candidate word being determined to be a keyword if the candidate word is included in the list.
[0022] The determining if the text data contains a keyword may involve counting the number of letters of a candidate word of the text data, the candidate word being determined to be a keyword if the number of letters is greater than a threshold number of letters.
[0023] The storing the keyword may involve storing the keyword, the keyword being associated with a contact record of the mobile communication terminal related to the remote party.
[0024] The method may further comprise, before the storing the keyword: if it is determined that the text data contains a keyword, displaying the keyword to the user.
[0025] The method may further comprise, before the storing the keyword: if it is determined that the text data contains a keyword, allowing the user to edit the keyword.
[0026] The converting audio data, determining if the text data contains a keyword, and if it is determined that the text data contains a keyword, storing the keyword, may be repeated until the audio communication ends.
[0027] The method may further comprise, after the audio communication ends: displaying all keywords determined during the audio communication.
[0028] The method may further comprise, after the displaying all keywords: enabling removal any of the displayed keywords.
[0029] The method may further comprise, after the displaying all keywords: enabling addition of user entered keywords to the displayed keywords.
[0030] A second expression of the second inventive aspect is a mobile communication terminal for storing keywords using a mobile communication terminal while a user of the mobile communication terminal is in audio communication over a communication channel with a remote party, the mobile communication terminal comprising a controller and memory, wherein: the controller is configured to acquire audio data related to the communication channel, the controller is configured to convert at least part of the audio data to text data; the controller is configured to determine if the text data contains a keyword; the controller is configured to, if it is determined that the text data contains a keyword, store the keyword in the memory, associated with information regarding the remote party.
[0031] A third expression of the second inventive aspect is a computer program product comprising software instructions that, when executed in a mobile communication terminal, performs the method according to the first expression of the second inventive aspect.
[0032] A first expression of the third inventive aspect is a method for managing contact data in a mobile communication terminal, where keywords are associated with a contact record stored by the mobile communication terminal, the method comprising: acquiring a keyword from text data related to communication with a party identified by the contact record; storing the keyword with an association to the contact record.
[0033] This automatically provides the user with key words for each contact, allowing the user to easier remember what person each contact record is associated with.
[0034] The acquiring a keyword may involve acquiring a keyword from text data in a text message communication with a party identified by the contact record.
[0035] The acquiring a keyword may involve acquiring a keyword from text data in a instant messaging communication with a party identified by the contact record.
[0036] The acquiring a keyword may involve converting at least part of audio data from voice communication with a party identified by the contact record to text data and acquiring a keyword from the text data.
[0037] The method may further comprise: when displaying a contact record, displaying at least part of keywords stored and associated with the contact record.
[0038] The method may further comprise: when displaying a list of contact records, displaying at least part of keywords stored and associated with each displayed contact record.
[0039] The displaying a list of contact records may involve: when displaying a list of contact records, displaying at least part of keywords stored and associated with each contact record, and for a highlighted contact record, scrolling through all keywords stored and associated with the highlighted contact record on one row.
[0040] The acquiring a keyword from text data may involve comparing a candidate word of the text data against a list of words, the candidate word being determined to be a keyword if the candidate word is excluded in the list.
[0041] The list of words may be a list of words used for predictive text functionality used when entering text in the mobile communication terminal.
[0042] The acquiring a keyword from text data may involve comparing a candidate word of the text data against a list of words, the candidate word being determined to be a keyword if the candidate word is included in the list.
[0043] The acquiring a keyword from text data may involve counting the number of letters of a candidate word of the text data, the candidate word being determined to be a keyword if the number of letters is greater than a threshold number of letters.
[0044] A second expression of the third inventive aspect is a mobile communication terminal for managing contact data, where keywords are associated with a contact record stored by said mobile communication terminal, said mobile communication terminal comprising a controller and memory, wherein:
[0045] said controller is configured to acquire a keyword from text data related to communication with a party identified by said contact record;
[0046] said controller is configured to store said keyword with an association to said contact record.
[0047] A third expression of the third inventive aspect is a computer program product comprising software instructions that, when executed in a mobile communication terminal, performs the method according to the first expression of the third inventive aspect.
[0048] Other features and advantages of the disclosed embodiments will appear from the following detailed disclosure, from the attached dependent claims as well as from the drawings.
[0049] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to “a/an/the [element, device, component, means, step, etc]” are to be interpreted openly as referring to at least one instance of the element, device, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] Aspects of the disclosed embodiments will now be described in more detail, reference being made to the enclosed drawings, in which:
[0051] FIG. 1 is a schematic illustration of a cellular telecommunication system, as an example of an environment in which the disclosed embodiments may be applied.
[0052] FIG. 2 is a schematic front view illustrating a mobile terminal according to an aspect of the disclosed embodiments.
[0053] FIG. 3 is a schematic block diagram representing an internal component, software and protocol structure of the mobile terminal shown in FIG. 2 .
[0054] FIG. 4 is a flowchart diagram illustrating the execution of the mobile terminal shown in FIG. 2 to record private sound clips.
[0055] FIG. 5 is a flowchart diagram illustrating the execution of the mobile terminal shown in FIG. 2 to store keywords for a phone call.
[0056] FIG. 6 shows a screen displaying previous calls with keywords found according to the process described in conjunction with FIG. 5 .
[0057] FIG. 7 a is a flowchart diagram illustrating the execution of the mobile terminal shown in FIG. 2 to store keywords for a contact.
[0058] FIG. 7 b is a flowchart diagram illustrating the execution of the mobile terminal shown in FIG. 2 to view keywords for a contact.
[0059] FIG. 8 shows a view of three displays illustrating the process described in conjunction with FIG. 7 b.
DETAILED DESCRIPTION
[0060] The disclosed embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
[0061] FIG. 1 illustrates an example of a cellular telecommunications system in which the disclosed embodiments may be applied. In the telecommunication system of FIG. 1 , various telecommunications services such as cellular voice calls, www/wap browsing, cellular video calls, data calls, facsimile transmissions, music transmissions, still image transmissions, video transmissions, electronic message transmissions and electronic commerce may be performed between a mobile terminal 100 according to the disclosed embodiments and other devices, such as another mobile terminal 106 or a stationary telephone 132 . It is to be noted that for different embodiments of the mobile terminal 100 and in different situations, different ones of the telecommunications services referred to above may or may not be available; the invention is not limited to any particular set of services in this respect.
[0062] The mobile terminals 100 , 106 are connected to a mobile telecommunications network 110 through RF links 102 , 108 via base stations 104 , 109 . The mobile telecommunications network 110 may be in compliance with any commercially available mobile telecommunications standard, such as GSM, UMTS, D-AMPS, CDMA2000, FOMA and TD-SCDMA.
[0063] The mobile telecommunications network 110 is operatively connected to a wide area network 120 , which may be Internet or a part thereof. An Internet server 122 has a data storage 124 and is connected to the wide area network 120 , as is an Internet client computer 126 . The server 122 may host a www/wap server capable of serving www/wap content to the mobile terminal 100 .
[0064] A public switched telephone network (PSTN) 130 is connected to the mobile telecommunications network 110 in a familiar manner. Various telephone terminals, including the stationary telephone 132 , are connected to the PSTN 130 .
[0065] The mobile terminal 100 is also capable of communicating locally via a local link 101 to one or more local devices 103 . The local link can be any type of link with a limited range, such as Bluetooth, a Universal Serial Bus (USB) link, a Wireless Universal Serial Bus (WUSB) link, an IEEE 802.11 wireless local area network link, an RS-232 serial link, etc. The local devices 103 can for example be microphones, headsets, GPS receivers etc.
[0066] An embodiment 200 of the mobile terminal 100 is illustrated in more detail in FIG. 2 . The mobile terminal 200 comprises a speaker or earphone 202 , a microphone 205 , a display 203 and a set of keys 204 which may include a keypad 204 a of common ITU-T type (alpha-numerical keypad representing characters “0”-“9”, “*” and “#”) and certain other keys such as soft keys 204 b , 204 c and a joystick 211 or other type of navigational input device.
[0067] The internal component, software and protocol structure of the mobile terminal 200 will now be described with reference to FIG. 3 . The mobile terminal has a controller 300 which is responsible for the overall operation of the mobile terminal and is preferably implemented by any commercially available CPU (“Central Processing Unit”), DSP (“Digital Signal Processor”) or any other electronic programmable logic device. The controller 300 has associated electronic memory 302 such as RAM memory, ROM memory, EEPROM memory, flash memory, hard drive, optic memory or any combination thereof. The memory 302 is used for various purposes by the controller 300 , one of them being for storing data and program instructions for various software in the mobile terminal. The memory 302 can be internal to the mobile terminal or an external memory connected to the mobile terminal. The software includes a real-time operating system 320 , drivers for a man-machine interface (MMI) 334 , an application handler 332 as well as various applications. The applications can include a contacts application 350 , as well as various other applications 360 and 370 , such as applications for voice calling, video calling, sending and receiving SMS, MMS or email, voice clip recording, web browsing, an instant messaging application, a calendar application, a control panel application, a camera application, a media player, one or more video games, a notepad application, etc.
[0068] The MMI 334 also includes one or more hardware controllers, which together with the MMI drivers cooperate with the display 336 / 203 , keypad 338 / 204 as well as various other I/O devices such as microphone, speaker, vibrator, ringtone generator, LED indicator, etc. As is commonly known, the user may operate the mobile terminal through the man-machine interface thus formed.
[0069] The software also includes various modules, protocol stacks, drivers, etc., which are commonly designated as 330 and which provide communication services (such as transport, network and connectivity) for an RF interface 306 , and optionally a Bluetooth interface 308 and/or an IrDA interface 310 for local connectivity. The RF interface 306 comprises an internal or external antenna as well as appropriate radio circuitry for establishing and maintaining a wireless link to a base station (e.g. the link 102 and base station 104 in FIG. 1 ). As is well known to a man skilled in the art, the radio circuitry comprises a series of analogue and digital electronic components, together forming a radio receiver and transmitter. These components include, i.a., band pass filters, amplifiers, mixers, local oscillators, low pass filters, AD/DA converters, etc.
[0070] The mobile terminal also has a SIM card 304 and an associated reader. As is commonly known, the SIM card 304 comprises a processor as well as local work and data memory.
[0071] FIG. 4 is a flowchart diagram illustrating the execution of the mobile terminal 200 shown in FIG. 2 to record private audio clips. When this process begins, a voice communication channel has been set up between a local mobile terminal 100 ( FIG. 1 ) and a remote mobile terminal 106 ( FIG. 1 ).
[0072] In a detect input for private recording step 402 , a user input is detected indicating that the user desires to start a private recording. The user input can be any type of suitable user input known in the art, including a dedicated key for audio recording, a soft key, a voice command, etc.
[0073] In a stop connection from microphone to communication channel step 404 , the connection between the microphone (internal or external) of the mobile terminal 100 and the communication channel is stopped. In other words, any audio caught by the microphone will no longer be transmitted over the communication channel to the remote mobile terminal 106 . In this embodiment, the audio detected by the remote mobile terminal 106 will still be transmitted over the communication channel to the local mobile terminal 100 , but it is equally possible to stop the communication from remote mobile terminal 106 to local mobile terminal 100 during the private recording.
[0074] In an acquire audio signal from microphone step 405 , the audio signal is received by the microphone is received. Also, in this step, any suitable processing known in the art is performed, such as analog-to-digital conversion, sound filtering, etc.
[0075] In a record audio signal step 406 , the processed audio signal from the previous step is recorded. The signal could be recorded in volatile memory, such as RAM, or permanent memory, such as flash memory.
[0076] In a conditional pause detected step 408 it is determined whether a user input representing a pause is detected. This user input can be an actuation of a soft key, a dedicated key, a voice command, etc. In one embodiment, a desire by the user to pause is detected by a release of the key that was used to initiate the private recording. If a pause is detected, the process proceeds to a reestablish connection from microphone to communication channel step 410 . If, on the other hand, a pause is not detected, the process proceeds to a conditional stop detected step 416 .
[0077] In the reestablish connection from microphone to communication channel step 410 , the connection between the microphone and the communication channel used for audio communication is reestablished. In other words, any audio detected by the microphone will hereafter be transmitted on the communication channel to the remote mobile terminal 106 .
[0078] In the conditional resume detected step 412 , it is determined whether a user input representing a resume is detected. If a resume is detected, the process returns to the stop communication from microphone to communication channel step 404 . If, on the other hand, a resume is not detected, the process proceeds to a conditional stop detected step 414 .
[0079] In the conditional stop detected step 414 , it is determined whether a user input representing a stop is detected. If a stop is detected, the process proceeds to a store audio signal step 420 . If, on the other hand, a stop is not detected, the process returns to the conditional resume detected step 412 .
[0080] In a reestablish connection from microphone to communication channel step 418 , the connection between the microphone and the communication channel used for audio communication is reestablished. In other words, any audio detected by the microphone will hereafter be transmitted on the communication channel to the remote mobile terminal 106 .
[0081] In the store audio signal step 420 the audio signal recorded in the record audio signal step 406 is stored in persistent memory.
[0082] It is to be noted that the effect of the process shown in FIG. 4 can alternatively be achieved using two or more separate multi-tasked processes, as is known in the art, where one of these tasks is responsible for receiving user input events and communicating these events to other tasks.
[0083] FIG. 5 is a flowchart diagram illustrating the execution of the mobile terminal 200 shown in FIG. 2 to store keywords for a phone call. When this process begins, a communication channel for voice communication has just been set up as a call between a local mobile terminal 100 ( FIG. 1 ) and a remote mobile terminal 106 ( FIG. 1 ). Optionally, this processing can be made user configurable, such that it will not be performed if the user has indicated it should not.
[0084] In an acquire audio data step 502 , audio data is acquired from the communication channel. The audio data can relate to either outgoing communication or incoming communication or both. In one embodiment, what communication is to be considered is user configurable. The audio data is captured when it is represented as digital data (or converted from analog to digital data), and optional filtering is applied. Typically, the audio data is temporarily stored in chunks for this process to process, allowing the voice call to proceed in one task (in a multitasking environment) in the mobile terminal 100 while still providing all the desired audio data to this process. This process then processes one chunk of audio data at a time, until there is no more audio data.
[0085] In a convert to text data step 504 , the audio data is converted to text data using a speech-to-text algorithm. The algorithm does not need to be perfect, it is sufficient if a substantial portion of the audio data is converted to text data. This will be discussed in more detail below. The output from this step is one or more words in text format.
[0086] In a select one unprocessed word in text data step 506 , one of the words in the extracted text data is selected for processing.
[0087] In the conditional is word keyword step 50 S, it is determined if the word being processed, or candidate word, is a keyword. There are several ways that this can be done, which will now be explained.
[0088] One way to determine a keyword is to check the word length of the candidate word. If the number of letters exceeds a certain number, the candidate word is considered to be a keyword. This will exclude most common words which are less unique and therefore less descriptive.
[0089] Another way to determine a keyword is to check if the candidate word is in a list of words which are considered less common and therefore are good keywords. Thus, if there is a match between the candidate word and a word in the list of less common words, the candidate word is considered a keyword. Optionally, the list of less common words is user configurable.
[0090] Yet another way to determine a keyword is to check if the candidate word is not in a list of words which are considered common. The candidate word is thus likely to be less common and therefore more unique if it is not in the list of common words. Such a list of common words can for example be a list of words used for predictive text entry, such as T9. Optionally, the user can edit this list of common words.
[0091] Additionally, in one embodiment, the candidate word can be checked against a list of keywords determined prior to the current call, where the candidate word is not considered a keyword if it has been determined to be a keyword previously, either in calls to the same remote mobile terminal, or all previous calls.
[0092] If the candidate word is considered a keyword, the process proceeds to a store keyword step 510 . If, on the other hand, the word is not determined to be a keyword, the process proceeds to a conditional all words in text data processed step 512 .
[0093] In the store keyword step 510 , the keyword is stored, associated with the call in progress. The keyword may be stored directly in persistent memory or it may be stored in volatile memory initially, for later storage in persistent memory.
[0094] In the conditional all words in text data processed step 512 , it is determined if all the words in the text data has been processed. If this is the case, the process proceeds to a conditional more audio data step 514 . If, on the other hand, there are more words to be processed, the process returns to the select one unprocessed word in text data step 506 .
[0095] In the conditional more audio data step 514 , it is determined if there is more audio data to process. If this is the case, the process returns to the acquire audio data step 502 . If, on the other hand, there is no more audio data to process, the process proceeds to a present found keywords to user step 516 .
[0096] In the present found keywords to user step 516 , the call has now ended and the user is presented with all keywords that have been found for the call that just ended.
[0097] In the user edit of keywords step 518 , the user can edit the keywords that are presented. The user can add, remove and edit keywords, before accepting the list. When the list is accepted, the keywords are stored in persistent memory, associated with the call in question and this process ends.
[0098] This process allows the user to browse previous calls and see keywords associated with each call. Consequently, the user is given hints to what the conversation was about.
[0099] One advantage with the process described above is that it works even if a recognition ratio of the voice-to-text algorithm is rather poor. Because only a small amount of keywords need to be saved for it to be useful, it is not really a problem if the voice-to-text algorithm recognizes 50% of the words or even less.
[0100] Optionally or additionally to the process described above, the user could be offered to see the list of words as they are created during the call and potentially even edit or use the words during the voice call e.g. copy selected words into a new text message.
[0101] FIG. 6 shows a screen displaying previous calls with keywords found according to the process described in conjunction with FIG. 5 . This is shown on a display such as the display 203 of FIG. 2 .
[0102] A screen 640 shows two previously voice call records 641 , 645 originated from the local mobile terminal 100 . Looking in more detail of one of the records 641 , the name 644 (as stored in the list of contacts) of the remote party of the conversation is shown on the first row. On the second row, the date and time 642 of the voice call is shown. Finally the keywords 643 extracted from the voice call is shown. The keywords 643 are here shown on two rows, but these could equally well be shown on one row or three or more rows. Additionally, if necessary, the keywords can scroll horizontally or vertically through the available space.
[0103] FIG. 7 a is a flowchart diagram illustrating the execution of the mobile terminal 200 shown in FIG. 2 to store keywords for a contact record. Optionally, this processing can be made user configurable, such that it will not be performed if the user has indicated it should not. The trigger to start this process can be a sent or received text message, multimedia message etc. or a start of a voice communication.
[0104] In an acquire text data associated with contact step 702 , text data associated with contact is acquired. This can for example be text data from a text message, text data from a multimedia message, text data from an instant messaging conversation, audio data from a voice call converted to text data using speech-to-text algorithms (like discussed above), etc. In other words, the text data can be any text data derived from communication with a contact.
[0105] In a select one unprocessed word in text data step 706 , one of the words in the acquired text data is selected for processing.
[0106] In the conditional is word keyword step 708 , it is determined if the word being processed, or candidate word, is a keyword. There are several ways that this can be done which will now be explained.
[0107] One way to determine a keyword is to check the word length of the candidate word. If the number of letters exceeds a certain number, the candidate word is considered to be a keyword. This will exclude most common words which are less unique and therefore less descriptive.
[0108] Another way to determine a keyword is to check if the candidate word is in a list of words which are considered less common and therefore are good keywords. Thus, if there is a match between the candidate word and a word in the list of less common words, the candidate word is considered a keyword. Optionally, the list of less common words is user configurable.
[0109] Yet another way to determine a keyword is to check if the candidate word is not in a list of words which are considered common. The candidate word is thus likely to be less common and therefore more unique if it is not in the list of common words. Such a list of common words can for example be a list of words used for predictive text entry, such as T9. Optionally, the user can edit this list of common words.
[0110] Additionally, in one embodiment, the candidate word can be checked against a list of keywords determined previously, where the candidate word is not considered a keyword if it has been determined to be a keyword previously, either as a keyword associated with the contact now in question, or all previous keywords.
[0111] If the candidate word is considered a keyword, the process proceeds to a store keyword associated with contact step 710 . If, on the other hand, the word is not determined to be a keyword, the process proceeds to a conditional all words in text data processed step 712 .
[0112] In the store keyword step 710 , the keyword is stored, associated with the contact in question. The keyword may be stored directly in persistent memory or it may be stored in volatile memory initially, for later storage in persistent memory.
[0113] In the conditional all words in text data processed step 712 , it is determined if all the words in the text data has been processed. If this is the case, the process proceeds to a present found keywords to user step 716 . If, on the other hand, there are more words to be processed, the process returns to the select one unprocessed word in text data step 706 .
[0114] In the present found keywords to user step 716 , the user is presented with all keywords that have been found in the acquired text data.
[0115] In the user edit of keywords step 718 , the user can edit the keywords that are presented. The user can add, remove and edit keywords, before accepting the list. When the list is accepted, the keywords are stored in persistent memory, associated with the contact in question and this process ends.
[0116] Optionally, the keyword list for each contact is limited to a certain number of keywords, where oldest words are removed as new words are added. In other the list would work according to a first-in-first-out order.
[0117] FIG. 7 b is a flowchart diagram illustrating the execution of the mobile terminal shown in FIG. 2 to view keywords for a contact.
[0118] In a display contact list with keywords step 720 , when the user wishes to view the contact list in the mobile terminal, the list is presented with keywords shown for each contact. The keywords can be shown on a separate row under each current contact. If all the keywords do not fit on one row, either the list is truncated by the edge of the display, or several rows are used. If truncation is used, a highlighted contact can let the keywords scroll horizontally allowing the user to view all the keywords over time.
[0119] In a display contact with key words step 722 , details about the contact is shown, including key words.
[0120] A search functionality can also be provided, allowing the user to search all the keywords for contacts for easier contact navigation.
[0121] FIG. 8 shows a view of three screens illustrating the process described in conjunction with FIG. 7 b , e.g. shown on display 203 of FIG. 2 .
[0122] A first screen 850 shows a screen of two contacts 851 , where one contact 852 is selected. The selected contact 852 shows keywords 853 on two rows, but one row could also be used. Optionally, the keywords can scroll automatically for the selected contact 852 . If the user presses a key associated with contact details 854 , e.g. the middle soft key, the mobile terminal switches to a contact details screen 860 .
[0123] In the contact details screen 860 , the contact details known in the art are shown. Additionally the keywords 861 associated with the contact are shown. If the keywords are selected (e.g. using joystick 211 of FIG. 2 ) and the user presses a key associated with viewing details 862 , the mobile terminal switches to a keyword details screen 870 ,
[0124] In the keyword details screen 870 , the keywords 871 are displayed in the main part of the screen. The user is provided with options to add, delete or edit the keywords.
[0125] For privacy reasons, the keyword functionality can be password protected. Additionally, the contact list can be configured not to display keywords.
[0126] Optionally, as an additional effect, the phone could have a pre-stored list of keywords which are mapped to certain colors which then are mapped to the contacts who have the specific keywords in their keywords field. E.g. the phone knows the word “honey” and if that word is included in a contact's keyword list, the contact name could be colored red to indicate affection.
[0127] While the term voice call has been used above, the disclosed embodiments is not limited to only voice calls. When the term voice call or voice communication is used, it is to be interpreted as communication including voice or audio communication. In other words, multimedia communication, including combined video and audio communication works equally well within the scope of the disclosed embodiments.
[0128] The invention has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended patent claims. | A method for recording audio using a mobile communication terminal while a microphone connected to the mobile communication terminal provides audio data for an audio communication channel to a remote party. The method includes detecting a first user input indicating a private recording is to be started; stopping provision of audio data from the microphone to the audio communication channel; receiving an audio signal from the microphone; and recording the audio signal.
Various methods of storing keywords are also presented. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to polymeric fibrids that contain particulate matter. More specifically, the invention concerns such fibrids which are particularly suited for use as obscurants of radar, electromagnetic waves and the like.
2. Description of the Prior Art
Effective means have long been sought for hiding the movement of troops and equipment from visual detection or from detection by means of devices that depend on reflection or absorption of electomagnetic waves, such as radar or infra-red waves. Smoke screens, tinsel foil dropped from airplanes and the like have been used in the past. However, more effective obscurant means are needed.
Though not related to the above-described problem, fibrids formed from organic polymers and processes for their production are known, as for example, from Morgan, U.S. Pat. No. 2,999,788. Morgan also discloses that various materials can be added to the fibrids, such as dyes, antistatic agents, surfactants, fillers such as silica, titanium dioxide or sand, pigments, antioxidants, electroluminescent phosphors, bronze powder, metal filings, and the like. Parrish et al, U.S. Pat. No. 2,988,782, discloses a specific shear-precipitation process for making fibrids, and certain equipment (tube fibridators) that is particularly suited for carrying out the process. Parrish et al also discloses the inclusion of fillers and pigments. Gross, U.S. Pat. No. 3,756,908, discloses a process for preparing fibrids of aramid polymers. Miyanoki, U.S. Pat. No. 4,146,510, discloses various flash-spun polymeric fibrids which a variety of finely divided that can pass through a less-than-100-mesh screen and are no more than 500 microns in nominal size, for use in forming pulps, sheets, etc. Rosser et al, U.S. Pat. No. 4,397,907, discloses a supercooled fiber-forming polymer solution which is combined with metal, graphite, lead oxide, iron oxide or other particles and then the polymer is formed into 500 to 10 7 Angstrom particles. The particles are trapped by or entangled with, but not encapsulated by, the polymeric particles, which then are optionally further beaten.
Some of the above-described particles have found use in papers and other nonwoven products, but none are disclosed as being air-dispersible.
Hugdin et al, U.S. Pat. No. 4,582,872 discloses that metallized polymers which are produced by melting metal and polymer together are suited for shielding electromagnetic interference. Luksch, U.S. Pat. No. 3,505,038, discloses "hair-like metal fibrils" that are dispersible or conveyable in air.
A purpose of the present invention is to provide loaded fibrids that can remain air-borne for a sufficiently long time (i.e., have a sufficiently slow settling rate) to be effective as electromagnetic-wave obscurants for hiding military operations.
SUMMARY OF THE INVENTION
The present invention provides polymeric fibrids loaded with an effective amount of an electromagnetic wave obscurant, the obscurant preferably being particles of conductive metal amounting to 30 to 70% of the total weight of the fibrids, and the loaded fibrids having an average size that passes through a 20-mesh screen and preferably is retained on 100-mesh screen and an average settling rate of no greater than 5 meters per minute, preferably less than 2 m/min and most preferably less than 1 m/min.
The present invention also provides a process for preparing the obscurant-loaded fibrids. The process includes shear precipitation of an organic polymer in the presence of an effective amount of particles of an electromagnetic wave obscurant. In a preferred process of the invention, the obscurant, in finely divided form, is uniformly dispersed in a polymer solution prior to the shear precipitation and after shear precipitation, the fibrids are dried and further reduced in size, as for example, by milling or shearing.
DESCRIPTION OF PREFERRED EMBODIMENTS
The invention is further illustrated by the following description of preferred embodiments. These embodiments and the examples that follow are included for the purposes of illustration and are not intended to limit the scope of the invention, which is defined by the appended claims.
As used herein, "electromagnetic wave obscurant" means a material that absorbs or reflects long wavelength electromagnetic radiation and includes radar and infrared radiation (i.e., a wavelength of at least 1,000 micrometers).
In accordance with the present invention the obscurant particles are incorporated, trapped or encapsulated in the fibrid. All such such fibrids are referred to herein as "loaded fibrids". Preferably, the polymer of the fibrid substantially completely encloses or covers the obscurant particles. The extent of encapsulation of the obscurant by the polymer can be evaluated with the aid of a Scanning Electron Microscope (SEM). The surface of the loaded fibrid is swept by a focused electron beam of the SCM. The scatt red and/or emitted electrons are detected electronically. The detector generates a signal which is collated on a cathode ray screen to produce an image. Examination of the loaded fibrids in this manner reveals how completely the obscurant particles are covered by polymer. In loaded fibrids made by preferred processes of the present invention, the obscurant particles are substantially completely covered with polymer. Even though obscurant particles may appear (under a microscope) to be only entrapped by the fibrid or on the surface of the fibrid, rather than deeply embedded within it, the obscurant particles nonetheless are covered or coated with fibrid polymer. Further evidence shows that the obscurant particles are covered by the polymer of the fibrids. Many of the iron particles incorporated into fibrids in accordance with the procedures of Examples 2, 4 and 7-9, below, do not appear, under an optical microscope, to be fully encapsulated within the polymer of the fibrid. Such iron particles usually oxidize very rapidly when exposed to air. However, examination of the iron-loaded fibrids after exposure to air for several weeks, revealed no signs of oxidation of the iron, thereby indicating that the iron particles were completely coated with the polymer. Also, it was noted that although the obscurant particles themselves conduct electricity, the obscurant-containing fibrids do not.
Electromagnetic wave obscurants suitable for loading into the fibrids of the present invention usually are conductors of electricity. For use in the present invention, the obscurants are usually in powdered or particulate form. Conductive obscurant materials include metals such as aluminum, copper, iron, nickel, and tungsten, metal alloys such as brass, carbon in graphite, coke or pitch form, salts such as copper sulfide and nickel sulfide, and the like. Suitable obscurants generally have a resistivity of less than 10,000 ohm-cms. To facilitate dispersion and incorporation of the obscurant in the polymeric fibrid, the obscurant particles usually have a maximum dimension or nominal particle size of less than about 50 microns, preferably, in the range of 0.1 to 2.5 microns.
Loaded fibrids usually contain obscurant particles amounting to no more than about 90% of the loaded fibrid weightand no less than 7.5%. When used as air-borne electromagnetic wave obscurants, the obscuring capacity of loaded fibrids varies directly with the concentration of fibrids in the air, the concentration of obscurant in the fibrids, and the rate at which the fibrids settle to the ground. To maximize obscuring effectiveness, the obscurant content of the fibrid should be as high as is consistent with a slow settling rate. Optimum concentration of obscurant is usually in the range of about 30 to 70 percent by weight of the loaded fibrid.
Many polymers are suitable for loading with obscurant particles in accordance with the invention. Morgan, U.S. Pat. No. 2,999,788 lists many such polymers. Because the so-called "hard" polymers of Morgan are more amenable to reduction in particle size, "hard" polymers are preferred. Such polymers include acrylonitrile polymers and copolymers; polyacrylic and polymethacrylic esters; cellulose esters, such as cellulose acetate; polymers and copolymers of vinyl chloride; polymers and copolymers of hydrocarbons, such as styrene, ethylene and propylene; polyesters, such as poly(ethylene terephthalate); polyamides, such as poly(hexamethylene adipamide); aramid polymers, such as poly(p-phenylene terephthalamide) and poly(m-phenylene isophthalamide); and many others. Because they are bio-degradable, cellulosic fibrids are preferred for use in the present invention.
In accordance with the present invention, the average size of the fibrids is usually no greater than that of fibrids which pass through a 20-mesh screen. Fibrids that pass through a 400-mesh screen are generally undesirable. Such small particles can be a respiratory hazard. Preferably, the smallest fibrids of the present invention will not pass through (i.e., they are retained on) a 100-mesh screen.
In accordance with the process of the invention, loaded fibrids are prepared by uniformly dispersing finely divided obscurant particles in a solution of polymer. The thusly formed dispersion is combined with a precipitant. Suitable precipitants are liquids in which the polymer can dissolve to no more than a 3% concentration (based on precipitant weight). Usually, the precipitant is at least slightly miscible with the polymer solvent. Preferably, the precipitant is completely miscible with the polymer solvent in the proportions used. Extensive information on the conditions required to form fibrids is described in Parrish et al, U.S. Pat. No. 2,988,782, the entire disclosure of which is hereby incorporated herein by reference. Although there are differences in conditions for specific combinations of polymer solution and precipitant, the directions of Parrish et al are generally applicable to the preparation of the fibrids of the present invention.
In preparing fibrids according to the invention, shearing of the polymer solutions can be performed by stirrers, the stirring blades or paddles of which are set at angles to the plane of rotation of the paddles or blades. The stirrer blade of a conventional Waring Blendor has a particularly satisfactory pitch. Shear and turbulence can be increased by introducing suitable baffles in the mixing vessel. Other means can be used for shearing polymer solution, so long as the equipment subjects the solution to sufficient shear to form the desired fibrids. For example, the polymer solution can be sheared by passage between solid surfaces which are in relative motion, such as between counter-rotating discs or between a rotating disc and a stationary disc or in a "tube fibridator", in which polymer solution is introduced through an orifice or series of orifices in the tube wall to subject the solution to high shear.
Freshly-precipitated fibrids produced by the shear precipitation step are filtered, washed to remove solvent and precipitant, and then dried (as for example in a vacuum oven or by freeze drying). Dried fibrids of the invention can be dispersed in a current of air. However, the dried fibrids prepared as described above frequently form a cake that is somewhat difficult to separate into individual, dispersible fibrids. Also, the loaded fibrids may require a further reduction in size. Separation of the fibrids and further size reduction fibrids can be accomplished by milling, by additional shearing (as in a Waring Blendor) or by seiving to remove larger-fibrid fractions.
In use, the fibrids may be made air-borne by being dropped from airplanes, raised aloft by thermal currents, dispersed by rockets, propelled from containers by gasses under pressure, fired into the air with mortar or artillery shells, or the like. Because of their very slow settling rates and the loaded fibrids of the invention are effective electromagnetic-wave obscurants.
Test Procedures
Several parameters and characteristics of the loaded fibrids of the invention are reported herein. These can be measured by the following test methods.
Settling rate of a fibrid sample is measured in a column of still air, provided inside a glass pipe, measuring 5.1 cm (2 inches) in diameter and 1.22 meters (48 inches) in length, the lower end of which is inserted into a sealed container. A first point for observing falling particles is located 19 cm (7.5 inches) below the top of the column. A second observation point is located 25.4 cm (10 inches) further down the column. The rate of descent of a fibrid of the invention has usually reached a stable constant value, by the falls to the first observation point. Initially the top of the column is covered by a 20-mesh screen.
To determine the settling rate of a particular batch of fibrids, an "elapsed time" is first measured, and then the settling rate of at least twenty-five individual fibrids, as follows. A first sample of about 25 milligrams of fibrids is placed atop the screen. The screen is gently tapped to cause the fibrids to fall through the screen and enter the air column. The screen is then replaced with a solid cover to assure that the column of air remains still. The time that elapses between when a first fibrid of the sample passes the first observation point and when the last fibrid of the sample passes that point is defined as the "elapsed time" for that sample of fibrids. Then, for each of the at-least-25 determinations of fibrid settling rate, a fresh 25-milligram sample is placed atop the screen; the screen is tapped; the screen is replaced by the cover; after a time period of one-half of the measured "elapsed time", the time required by a particular fibrid passing the first observation point to reach the second observation point is measured. The results of the at-least- 25 determinations are averaged and reported as the settling rate in meters per minute.
The size of a sample of fibrids is determined by means of seive analysis. seive mesh. A Testing Sieve Shaker Model B made by W. S. Tyler, Inc. Combustion Engineering, Mentor, Ohio, is employed. The apparatus consists of a brass cylinder with a removable top and bottom and in which cylindrial brass screens of various standard mesh sizes are placed. The sides of the screens have a depth of about two inches. The screens used for determining the sizes reported herein are U.S. Standard Sieve Series purchased from Preiser Scientific Company. The particular sequence of mesh sizes employed is a 20-mesh screen as the top screen, followed by screens of 40, 60, 80, and 100 mesh. A weighed sample is placed atop the 20-mesh screen and the cover is put in place. The closed cylinder is then placed in a shaker which simultanously shakes the cylinder and taps the top which causes the particles of sizes less than that of a particular screen mesh to pass through the screen. After 45 seconds, the shaking is stopped and the amount of material collected on each screen and on the bottom is weighed. The particles on any screen can be characterized as having been unable to pass through a screen of that mesh but having been able to pass through the preceding screen.
The examples which follow are illustrative of the invention and the results reported therein are believed to be representative but do not constitute all the runs involving the indicated ingredients. In the examples, when a particle size is given in terms of a mesh size, the mesh refers to the seive on which the particles were retained in the hereinbefore-described seive test or it refers to the particle size quoted by the maufacturer of the particles.
EXAMPLES 1-7
These examples illustrate the preparation of various polymeric fibrids in which various powdered obscurants are loaded in accordance with the invention. Fibrids of acrylonitrile are loaded with aluminum and iron (Examples 1 and 2, respectively); fibrids of acrylonitrile copolymer, with copper (Example 3); fibrids of poly(m-phenylene isophthalamide) with iron and tungsten (Examples 4 and 5, respectively); and fibrids of cellulose acetate, with graphite and iron (Examples 6 and 7, respectively). Characteristics of the fibrids are summarized in Table I. The settling rates reported in Table 1 were determined by the above-described test and are for the fraction of the fibrids that pass through a 20-mesh U. S. Standard Seive.
EXAMPLE 1
To a three-neck 1-liter round-bottom flask, equipped with a mechanical stirrer and a nitrogen gas inlet, 279 grams of dimethylacetamide and 21 grams of polyacrylonitrile were added. The mixture was stirred at room temperature until a clear solution formed. Then, 21 grams of powdered aluminum was added to the solution, to form a suspension of the aluminum particles in the polymer solution. The aluminum particles were obtained from Cerac, Inc., 407 13th St., Milwaukee, Wis. 53233 and were of 1 micron or less in size. The thusly formed suspension was added slowly to a 0.5% aqueous solution of sodium alginate, while being stirred vigorously in a Waring Blendor, to form a suspension of polymeric fibrids in which the aluminum particles were loaded. The fibrids were filtered, washed with acetone, and dried in air. The fibrids contained about 50% by weight of aluminum and had settling rates of 3.6 meters/min.
EXAMPLE 2
A polymer solution was prepared in the apparatus of Example 1 by adding 14 grams of polyacrylonitrile to 186 grams of stirred dimethylacetamide to form a clear solution. To the stirred clear solution, 28 grams of iron particles which passed through a 325-mesh screen (nominal diameter of about 44 microns) were added. Stirring was continued until the iron particles were well dispersed. The dispersion was then added to a vigorously stirred 50/50 mixture of glycerol and water in a Waring Blendor to produce iron-loaded acrylonitrile fibrids. The fibrids were washed with water and then acetone, and then dried in air. The loaded fibrids contained about 67% by weight of iron. The settling rate of the iron-loaded fibrids was 4.6 m/min.
EXAMPLE 3
In the same apparatus as was used in Example 1, 79 grams of dimethylacetamide were added and chilled to -20° C. While being stirred, 21 grams of a copolymer containing, by weight, 93.2% acrylonitrile, 6% methyl acrylate, and 0.8% sodium styrene sulfonate were added to the chilled liquid. When the addition of the copolymer was completed, cooling was stopped, but stirring was continued as the temperature rose to room temperature and continued thereafter for about 16 hours. A clear polymer solution was obtained. Then, while stirring continued, 21 grams of pulverized copper were added to the clear polymer solution to thoroughly disperse the copper in the solution. The thusly formed dispersion was added slowly to a vigorously stirred 0.5% aqueous solution of sodium alginate in a Waring Blendor to form fibrids in which copper particles were loaded. The copper-loaded fibrids were washed with water and then acetone and then dried under vacuum. The copper content of the fibrids was found to be 34.6%. Apparently, some of the copper was not incorporated in the fibrids. The settling rate of the fibrids (labelled Example 3a in Table I) was measured to be 4.7 m/min.
A portion of the dried copper-loaded fibrids was further reduced in size by being subjected to shearing in a Waring Blendor operating at high speed for about one minute. The smaller copper-loaded fibrids (labelled Example 3b in Table I) had a settling rate of 3.9 m/min.
EXAMPLE 4
To 143 grams of a dimethylacetamide solution containing (by weight) 9% calcium chloride, 1.5% water, and 19.3% poly(m-phenylene isophthalamide) in the apparatus of Example 1, 93 grams of dimethylacetamide were added. The mixture was stirred until a uniform dilute solution formed. This dilute solution contained 7% by weight of solid material. Twenty grams of 325-mesh iron powder (from Peerless Metal Powders, Inc.) were added to the dilute solution and the mixture was stirred until a uniform dispersion was formed. The dispersion was poured slowly into a Waring Blendor containing 500 cm 3 of a vigorously stirred 60/40 (by volume) mixture of water and dimethylacetamide. Iron-loaded fibrids were produced, collected on a Buchner funnel, washed with water, then with acetone, and then dried under vacuum at 80° C. These fibrids contained about 67% by weight of iron. The dried fibrids were reduced in size in a Waring Blendor. The smaller size fibrids had a settling rate of 1.1 m/min.
EXAMPLE 5
To 80 grams of the poly(m-phenylene isophthalamide) polymer solution in dimethylacetamide of the Example 4, 20 grams of tunsten powder having an average diameter of 500 micrometers in diameter were added with stirring. An additional 200 grams of dimethylacetamide was added to the stirred mixture. The resulting slurry was added to a 50/50 mixture of water and diamethylacetamide in a Waring Blendor operating at full speed to form tungsten-loaded fibrids. The loaded fibrids were rinsed with water. Three grams of an anionic surfactant were added to the rinsed fibrids, which were then placed in two liters of boiling water for two hours. The tungsten content was about 56% of the total weight of the loaded fibrid. The loaded fibrids were filtered, washed three times with water, and dried under vacuum at 110° C. The dried fibrids were further reduced in size in a Waring Blendor. The resultant fibrids had a settling rate of 1.8 m/min.
EXAMPLE 6
In the apparatus of Example 1, a solution was prepared by dissolving 7 grams of cellulose acetate in 93 grams of dimethylacetamide. To the solution, 14 grams of 325-mesh graphite (J. T. Baker Technical Grade) were added and stirred until a uniform dispersion was obtained The dispersion was poured slowly into a Waring Blendor containing 350 cm 3 of a vigorously stirred 50/50 mixture of water and glycerol. Graphite-loaded fibrids were produced in which the graphite amounted to about 67% by weight of the loaded fibrids. The loaded fibrids were collected in a Buchner funnel, washed with water, and then dried under vacuum at approximately 90° C. The dried fibrids were reduced in size in a Waring Blendor. The resultant fibrids had a setting rate of 0.6 m/min.
EXAMPLE 7
An iron powder, of the same type as was used in Example 4, and a process of the general type that was employed in Example 6, were used to prepare cellulose acetate fibrids containing approximately 67% by weight of iron. A waterleaf handsheet was prepared by pouring a slurry of these fibrids onto a wire screen. The handsheet was dried and reduced to small size particles in a Waring Blendor. The resultant fibrid particles were sieved to two classifications: (a) fibrids that passed a 40-mesh screen but were retained by a 60-mesh screen and (b) fibrids that passed through the 60-mesh screen. The settling rate of each classification of iron-loaded fibrids was about the same, about 0.5 m/min.
TABLE 1______________________________________Settling Rates of Fibrids of Examples 1-7 SettlingExample Fibrid Encapsulated Obscurant RateNo. Polymer.sup.1 Powder Percent.sup.2 m/min______________________________________1 AN Aluminum 50 3.62 AN Iron 67 4.6 3a AN/MA/SSS Copper 35 4.7 3b AN/MA/SSS Copper 35 3.94 MPDI Iron 67 1.15 MPDI Tungsten 56 1.86 CA Graphite 67 0.6 7a CA Iron 67 0.5 7b CA Iron 67 0.5______________________________________ Notes: .sup.1 AN = acrylonitrile polymer AN/MA/SSS = copolymer of 93.2% acrylonitrile, 6% methyl acrylate and 0.8% sodium styrene sulfonate MPDI = poly(mphenylene isophthalamide) polymer CA = cellulose acetate polymer .sup.2 By total weight of loaded fibrid
EXAMPLES 8-9
Examples 8 and 9 illustrates (a) the size distribution of fibrids of the invention and (b) the further reducing of dried, shear-precipitated fibrids in size. These effects are shown with cellulose acetate fibrids, in which iron obscurant particles, amounting to two-thirds of the total fibrid weight, are loaded.
Fibrids, prepared by shear-precipitation techniques substantially as described in Example 7, were dried and reduced in size by shearing in a Waring Blendor operated at high speed for about one minute. For the fibrids of Example 8, a 10% cellulose acetate polymer solution was shear precipitated; for Example 9, a 7% solution was used. The original shear-precipitated portion is referred to as part "a" of each example; the additionally sheared portion, as part "b". The results of seive size distribution analysis of the thusly prepared fibrids are summarized in Table 2 below, in which all percentages are by weight of the total sample.
Settling rates of seived fractions of the fibrids which passed through a 100-mesh U. S. Standard Seive were determined and, as recorded in the table, was in the range of 0.4 to 1.0 m/min.
TABLE 2______________________________________Size Distribution of Fibrids of Examples 8-9Example No. 8a 8b 9a 9bFibrids As-made Reduced As-made Reduced______________________________________% retained on: 40-mesh screen 37.7 21.5 22.7 8.1 60-mesh screen 7.7 37.9 22.0 25.4 80-mesh screen 0.7 13.8 7.3 17.2100-mesh screen 0.2 6.5 3.2 9.8% passing through: 20-mesh screen 46.6 95.9 61.3 94.7100-mesh screen 0.1 16.2 6.2 34.2Settling Rate m/min 1.0 0.7 0.7 0.4Of fibrids passing100-mesh screen______________________________________ | Polymeric fibrids are loaded with particles that obscure the absorption or reflection of radar, infra-red or other electromagnetic waves. The loaded fibrids have settling rates that are slower than 5 meters per minute and are suited for use as air-borne obscurants of movements of military personnel and equipment. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates in general to winning machines for winning minerals, coal or the like.
More particularly, this invention pertains to a rotating cutting roller for such a winning machine.
Even more particularly, the present invention relates to a spraying nozzle system operated for suppressing coal dust produced during the winning operation.
It is known that, when a cutting drum provided with a plurality of cutting picks or bits is utilized in the winning machine, spraying nozzles are used for individual picks which spray water onto the picks of the rotating drum to suppress mineral or coal dust produced during the underground mining. Spraying jets applied by the nozzles to the cutting picks are usually so directed that about one third of the free length of the individual pick is stricken by the spraying jet. Thereby the pick is substantially cooled and its service life is increased. The spraying water is normally supplied to the periphery of the cutting drum or roller from the water supply source through the tubular support of the cutting roller. Water is then fed from the tubular support, namely from a special conduit provided in the interior of the tubular support, to fluid distribution channels or passages which are arranged in the foot areas of the helical blade and the locking ring of the cutting roller, adjacently to the outer circumferential surface of the tubular support. Such a fluid distribution passage is usually formed either in the foot area of the locking ring and extends in the circumferential direction of the locking ring or is immediately cut in the foot area of the respective blade and extends according to the shape of the blade in the direction of the outer surface of the tubular support. Individual holes are made in the cutting roller, which extend from the distribution passages to the spraying nozzles. Radial connecting channels or passages formed as deep bores can be also provided in the cutting roller between the fluid distribution passages and the nozzles.
German Offenlegungsschrift No. 2,261,206 discloses a cutting drum for a winning machine, which is provided with a number of helical blades formed of segments. The cutting drum has a fluid distribution channel which extends circumferentially of the respective blade and is radially spaced from the outer surface of the body of the drum. The fluid distribution channels for individual adjacent segments are not connected to each other.
German Offenlegungsschrift No. 2,032,846 describes a cutting roller, in which the fluid distribution channel is formed in the region of the blade, sheltered from the winds, inside of the free edge area of the blade extended transversally to the welded profile iron portion thereof, said channel extending in the circumferential direction of the blade. This fluid distribution channel formed as a conduit is held in position by clamping straps. The disadvantage of this otherwise satisfactory construction is that it has unfavorable loading effect on the blade due to the welded profile iron portion and because of the unfavorable arrangement of the elongated fluid distribution conduit in the area of the outer periphery of the blade, and wherein the clamping straps present a further source of disturbance. The construction expenses in this design are extremely high and thus manufacturing costs are high, respectively. A further disadvantage of the cutting drum described in this German publication is a possibility of blocking of the channel system due to possible corrosive sediments. Furthermore, a multiple coiled fluid supply conduit formed as a hose is provided in this known construction, which should be disposed in the interior of the body of the cutting drum. A similar construction is disclosed in German Pat. No. 1,242,539, this structure being also very expensive.
German Pat. No. 1,272,257 shows a cutting drum or roller in which pick holders extend in the circumferential direction of the blade and are welded to the blade by the fluid distribution conduit formed as a U-iron piece, or are connected to the blade by a weld seam by means of a tubular profile iron piece which in turn is connected, also by welding, to the fluid distribution conduit. This construction is disavantageous in that cracks may be formed in the structure which would lead to leakage in the fluid distribution conduit. Spraying nozzles in this construction direct the spraying jets also unfavorably, namely onto the free spaces rather than onto the picks so that the picks are not properly cooled whereby the service life of these picks is shortened and the picks must be replaced when worn out. The structure is also bulky due to the arrangement of its components on the free periphery of the blade.
British patent specification No. 1,309,005 discloses a rotary cutter for a mineral mining machine, in which water spraying conduits are formed of nylon tubes. The water spraying system of the British disclosure is very complicated and also very expensive in manufacturing.
German patent publication No. 27 25 8726 discloses a cutting roller for a winning machine, in which water spraying system includes a water distribution passage extended circumferentially of the helical blade of the roller, and a radially extended bridging passage to which water or cooling fluid is supplied from a fluid supply passage arranged in the interior of the tubular support of the roller. The fluid spraying system is also provided with connection channels which extend from the fluid distribution passage to individual spraying nozzles. Since the fluid distribution passage is spaced radially outwardly from the outer face of the tubular support forces generated at the weld seam at the foot of the blade act so that they do not unfavorably affect that seam. Furthermore, the manufacturing of such a fluid spraying system presents no problems because the fluid distribution passage is made by milling a groove in the body of the blade. To close such a groove a sheet-like strip formed according to the shape of the groove is provided, which is connected to the body of the blade or the locking ring, if the groove is formed in the latter, by welding. All fluid conducting conduits formed in the cutting roller and including the fluid supply conduit, the fluid distribution conduit and the connection conduits which lead to individual spraying nozzles, have a corrosion-resistant lining or coating to prevent the formation of corrosive sediments on the interior surfaces of the entire fluid channel system. Due to the above arrangement the reliable operation of the whole fluid channel system is warranted. This also results in increase of cutting capacity of the cutting picks and in a longer service life of the picks, particularly in those cases when the whole cutting roller is made out of stainless steel, for example of NIROSTA or a suitable material containing chromium-molybdenium-manganese-nickle-steel.
Apparenty tubes or hoses of synthetic plastic material can be used in the fluid channel system for conducting a spraying fluid; such tubes or hoses should be tightly sealed at the transition or connection zones with each other by clamping straps. The cutting rollers in which such tubes can be utilized have the advantage that the whole channel system is protected against corrosion. However, even this structure has the disadvantage which resides in that it requires repair and cleaning of the interior of the channel system due to corrosion of covering strips and shields which are welded to the body of the blade or the locking ring. These repair and cleaning operations are bothersome and costly and should be usually carried out at work side.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved cutting roller for a winning machine.
It is a further object of this invention to provide a rotary cutting roller with an improved water-spraying system.
It is still another object of the invention to provide a cutting roller with a fluid channel system having fluid passages with corrosion-resistant coating, particularly with a fluid distribution passage and connection passages leading to the individual nozzles, formed with such a coating, and in which passages tubes or hoses of synthetic plastic material are disposed which are connected to each other clamping straps and short transition sleeves whereby a required repair or cleaning of the fluid channel system can be carried out fast and without any problems.
These and other objects of the invention are attained by a cutting roller for a winning machine, comprising an elongated tubular support; at least one helical blade provided on a circumferential surface of said support; a locking ring connected to said tubular support at one end thereof, said blade and said locking ring each having side walls and a periphery and each being provided with a plurality of pick holders on said periphery for receiving cutting picks therein; spraying nozzles located on said blade and said locking ring near said pick holders and each being assigned to a respective pick holder for spraying a hydraulic fluid on the respective pick; at least one fluid supply passage means formed in said tubular support for said blade and said locking ring; fluid distribution passage means formed in said blade and extended circumferentially thereof and also formed in said locking ring; a plurality of connecting channels for connecting said fuid distribution passage means to individual spraying nozzles, said fluid distribution passage means being radially outwardly spaced from the outer circumferential surface of said tubular body towards said spraying nozzles, said fluid distribution passage means including a first circumferential groove formed in the side wall of said blade and a second circumferential groove formed in the side wall of the locking ring, said first and second grooves being closed with respective covers; bridging passage means for connecting the fluid supply passage means to said fluid distribution passage means, said bridging passage means including a third radially extended groove formed in the side wall of said blade, said third groove being closed with a cover, said covers for said first and second grooves and said cover for said third groove being detachably connected to the blade and to the locking ring, respectively, and being made of non-corrosive material.
In the cutting roller according to the invention the covers which close the fluid passages, for example the fluid distribution passage, are connected to the respective blade or the locking ring in such a manner that no corrosion due to operation with a spraying fluid occurs on the blade, or the locking ring or the tubular support; these covers can be easily detached from the respective components of the cutting roller and also easily connected to them.
When the respective cover is removed from the blade or the locking ring and the plastic hose located in the respective groove is exposed, the operator can easily exchange the hose or the tube, after releasing the clamping straps, if desired.
The channel system according to the invention makes possible an easy cleaning of the entire fluid-conducting system.
The covers may be screwed to the respective walls of said blade and said locking ring by bolts. This structure is particularly advantageous for operation in underground mines.
Furthermore, the covers may be clamped to the respective walls of said blade and said locking ring. Small hand grips can be used to detach the covers from those walls and bring them again to a closed position.
The covers may be also connected to the respective walls of said blade and said locking ring by hinges.
The covers may be formed as sheet-like strips, or profiled iron-pieces or as segments connected to each other. The last construction is suitable particularly for specifically shaped fluid distribution channels when such a channel is divided along its length into a plurality of individual portions which are easy to handle.
The hinge-like structure includes covers which are pivotally connected to the respective wall of the blade or the locking ring and may be secured to that wall in the closed position, for example by screws.
The fluid distribution passage means may further include a tubular conduit made of synthetic plastic material and located in said first groove, said connecting channels being each formed of a tubular conduit of synthetic plastic material, said first mentioned tubular conduit being connected to the tubular conduit of the respective connecting channel by a T-shaped connecting member.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a cutting roller with cutting picks omitted, according to one embodiment of the invention;
FIG. 2 is a perspective view of the cutting roller, also with the cutting picks not illustrated, according to a further embodiment of the invention;
FIG. 3 is a sectional view along the line III--III of FIG. 4;
FIG. 4 is a view, partially in section, along the line IV--IV of FIG. 2;
FIG. 4a is a view similar to that of FIG. 4 but with the cover strip connected to the blade by a hinge; and
FIG. 4b shows the cover formed of a number of segments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, reference character 1 denotes a tubular support, on the outer surface of which a helical blade 2 is arranged. This blade extends radially outwardly from the outer surface of support 1 and has a helically formed plate-like configuration. A number of identical blades axially spaced from each other and disposed at a predetermined angle of inclination to the periphery of support 1 can be provided on the cutting roller. Each blade is, at its foot region, rigidly connected, for example welded, to the outer surface of support 1. Reference numeral 4 designates a locking ring the annular portion of which, which is conically open towards the working face, is also rigidly connected to support 1. The blade 2 as well as the locking ring 4 are provided at the outer periphery thereof with a plurality of pick holders 3 and 6 which are circumferentially spaced from each other an equal distance. Each pick holder carries in the known manner a cutting pick (not shown herein) which extends outwardly away from the respective pick holder, to perform cutting of the material, e.g. mineral.
The cutting roller according to the invention can be particularly suitable for use in underground mining with winning machines.
It is to be understood that the locking ring 4 and blade 2 each have similar constructions in the both illustrated embodiments of the invention. Locking ring 4 is also connected to the support 1 by welding and is of the structure known in the art.
Reference numeral 5 denotes a cover which closes the cutting roller in the direction of the working face.
As shown further in FIGS. 1 and 2, a number of spray nozzles 7 or 8 are provided on the blade 2 or locking ring 4, each of which corresponds to the respective pick holder 3 or 6. Spray nozzles 7 and 8 are formed near respective pick holders to spray water onto the cutting picks at a predetermined angle. The water spray or jet from the nozzles is so directed that it strikes against the upper or third portion of the respective pick so that the latter is cooled and damage to a hard metal solder on the picks due to their overheating will be prevented. Thereby a service life of the cutting picks is significantly increased. Due to the sprays of water applied to all the picks the cutting roller is surrounded with a spray mist and dust produced during the mining becomes suppressed. Therefore such cutting rollers do not contaminate the environment.
The constructions in which an individual nozzle corresponds to each individual pick is known as "an individual nozzle system".
A fluid supply passage or a fluid feeding passage is formed in the known manner in the interior of the tubular support 1. Such a passage is not shown in the drawing. A special respective tube or a conduit which is connected to that fluid supply passage by means of a nipple or the like leads to the fluid distribution passage and from there to the respective blade 2 or the locking ring 4 in the manner described herein below.
In the embodiment illustrated in FIG. 1 a radially extended bridging conduit 9 is provided, which can be formed by a groove cut in the side wall of blade 2. In the embodiment depicted in FIG. 2 the connection is effected by means of one or more radially extended holes formed in the blade 2 which are also connected to the fluid supply passage. Such holes are not shown in the drawings for the sake of simplicity. Similar holes are formed in the locking ring to conduct water from the fluid supply passage to the periphery of the locking ring. The bridging conduict 9 is closed by a sheet metal strip 10.
Reference character 11 designates a distribution passage which extends in the circumferential direction of blade 2 and is uniformly spaced in the radial direction from the outer surface of tubular support 1. Distribution passage 11 is also closed by one or several sheet metal strips 12. Distribution passage 11 is formed as a recess or groove cut or milled in the side wall of blade 2.
In the embodiment of FIG. 2 a distribution passage 13 is provided, which is arranged similarly to the distribution passage 11 of FIG. 1 and closed or covered by a sheet-like strip 14.
Strips 10, 12 and 14 are connected to the body of the blade by screws or bolts so that they can be removed from the blade without any problem. The distribution passage 13 of the embodiment of FIG. 2 also formed as a groove or recess in the wall of blade 2 is connected to one or more fluid supply passages (not shown). Each distribution passage 11 or 13 is in turn in communication with a respective connection passage or channel 28 which leads to a respective nozzle-receiving member and thus to a respective nozzle, for example nozzle 7 to supply the latter with a spraying hydraulic fluid.
With reference to FIGS. 3 and 4 which show details of FIG. 2 it is shown that the distribution passage 13 is formed as a groove or recess cut in the back side wall of blade 2. This groove is closed along the length thereof with sheet-like strip 14 which is secured to the body of blade 2 by bolts 16 (only one bolt 16 is shown in FIG. 4). A tubular conduit 17 extends from the passages which lead to the spray nozzles, for example nozzle 7.
The conduit system shown in FIGS. 3 and 4 is formed of hoses or tubes of synthetic plastic material which has considerable flexibility. Tubes 18 and 19 of synthetic plastic material, which are connected to each other, form the distribution conduit located in the recess 13 and the tube or hose 20 of synthetic plastic material forms the conduit 17.
Tubes 18 and 19 are connected to each other and to the tube 20 by a T-like element 24 extended with its portions into and engaged in openings of tubes 18, 19 and 20, respectively. Clamping straps 21, 22, 23 hold the ends of the tubes connected to each other in the fixed position. Clamping straps 21, 22, 23, 25 can be metallic whereas the T-shaped connection member 24 can be made out preferably of a corrosion-resistant synthetic plastic material suitable for operation underground and with minerals being or of stainless steel.
The end of plastic tube 20 overlaps the connection nipple of a nozzle-receiving member 26. The clamping strap 25 is arranged at the end of tube 20, which end receives an axial projection 30 formed on the nozzle-receiving member 26. Thus clamping strap 25 clamps the tube 20 on the nozzle-receiving member.
As can be understood the conduit system according to the invention can be easily exposed for cleaning or repair merely by removing sheet-like strips 14 and without disassembling of one or more plastic tubes. After required cleaning or repair cover strips 14 can be again mounted to their closed position. In the system of the invention therefore, no components subjected to corrosion are used.
The cover strips 10, 14 can be clamped to the blade by any suitable means.
The cover strips 10, 14 can be formed not only as sheet-like strips, but also made out of a profile iron or made of segments a shown in FIG. 4b.
Furthermore, it is possible to connect the cover strips 10, 14 to the blade 2 or locking ring 4 by a hinge 27, as shown in FIG. 4a, so that they can swing to and from the blade or locking ring.
It is to be understood that similar fluid distribution circumferential passages as well as radially extended bridging passages are provided in the side wall of the blade 2 and in the back side wall of the locking ring 4 for supplying hydraulic fluid to the respective spraying nozzles.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of cutting rollers differing from the types described above.
While the invention has been illustrated and described as embodied in a cutting drum, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | A cutting roller for a winning machine, which includes a tubular support and a number of helical blades on the tubular support provided with cutting picks arranged on the periphery of each blade, is provided with a hydraulic fluid spraying system which comprises a circumferential fluid distribution passage formed in the blade, connecting passages leading to the spraying nozzles and a radial bridging passage connecting the fluid distribution passage with the connecting passages. The fluid distribution passage and the bridging passage are grooves which accommodate plastic fluid-conducting tubes. The grooves are covered with covers of non-corrossive material which are releasably connected to the walls of the blade. | 4 |
FIELD OF INVENTION
[0001] The present invention generally concerns devices, systems and methods for establishing and releasing a vacuum seal; and more particularly, in various representative and exemplary embodiments, to devices adapted to facilitate the vacuum release and sealing of jars, bottles or other containers.
BACKGROUND
[0002] It is well known that perishable foods stored at reduced pressure maintain their freshness longer. Food articles, such as tea, fruit, nuts, preserves, etc. may be vacuum sealed in order to maintain freshness over extended periods of time. In general, vacuum packed foods will begin to loose their freshness the moment the vacuum seal provided during original packaging is lost.
[0003] Vacuum sealed containers are generally well known. Typical vacuum sealed vessels may include containers for food products, such as: jelly, pickles, condiments, beverages, baby food, and the like. In some vacuum sealed containers, the lid may be at least partially held against the containment volume by the reduced pressure of the vacuum seal itself. Releasing the vacuum seal will generally allow for removal of the lid closure.
[0004] In other vacuum sealed containers, the lid may also be adapted for threaded engagement with the container, such that removal of the lid may involve both releasing the vacuum seal and unscrewing the lid. Often, the lids of vacuum sealed containers may be formed with a slight concave depression near the center of the lid, indicating that the vacuum seal has not been compromised. After the vacuum seal has been released, the depression may be convex or domed and/or flexible to manual pressure and/or emitting a slight oil can noise with manual pressure, indicating that the vacuum seal has been broken. A concave, domed or flexible depression may also indicate that even if the lid has not been removed from the container, the vacuum seal has been compromised. Once the vacuum seal has been released or compromised, the contents of the container will typically have a more limited shelf life.
[0005] When the lid closure is retained by a vacuum seal alone, a common tool for releasing the seal is one that is adapted to pry the edge of the lid away from the container; however, this may cause permanent damage of the lid, such that it may be difficult to reuse the lid closure to provide a subsequent good seal. If the lid closure is also adapted for threaded engagement with the container, conventional procedures for loosening the lid may involve, for example, tapping the jar or bottle on a surface, hitting a corner of the lid with a utensil, or running hot water over the lid closure to expand the lid material away from the containment vessel material. Such procedures may crack the container or introduce water or glass chips into the product, which may be difficult to remove.
[0006] In order to assure the quality and shelf life of stored food contents, the vacuum seal must generally be impermeable to fluids and gases. Accordingly, releasing the vacuum seal to open the container may be difficult to accomplish by manual manipulation alone. Many of the food articles stored in vacuum sealed containers, such as condiments and sauces, are stored with screw lids. It can be difficult for people to open and reseal screw lids, especially people who are physically disabled, elderly, suffering from carpal tunnel syndrome, arthritis, tennis elbow, sprains, and/or the like and persons with weakness in their hands or arms.
[0007] Accordingly, there is a need to provide a mechanism for easily releasing the vacuum seal of jars, bottles and similar containers which avoids prior difficulties and makes opening and re-establishing a vacuum seal quick, easy and safe.
SUMMARY OF THE INVENTION
[0008] In various representative aspects, the present invention provides an apparatus and method for establishing and/or releasing a vacuum seal. Exemplary features are generally disclosed as including methods for puncturing a portion of a lid closure with a penetrator device, actuating a vacuum pump to remove at least a portion of atmospheric gas from inside the containment vessel via the puncture hole, and sealing the puncture with a laminar valve.
[0009] Advantages of the present invention will be set forth in the Detailed Description which follows and may be obvious from the Detailed Description or may be learned by practice of exemplary embodiments of the invention. Still other advantages of the invention may be realized by means of any of the instrumentalities, methods or combinations particularly pointed out in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Representative elements, operational features, applications and/or advantages of the present invention reside in the details of construction and operation as more fully hereafter depicted, described and claimed—reference being made to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout. Other elements, operational features, applications and/or advantages may become apparent in light of certain exemplary embodiments recited in the Detailed Description, wherein:
[0011] FIG. 1 representatively illustrates a vacuum seal release device in accordance with an exemplary embodiment of the present invention;
[0012] FIG. 2 representatively illustrates a vacuum seal release device in accordance with another exemplary embodiment of the present invention;
[0013] FIG. 3 representatively illustrates a partially exploded view of a vacuum device that may be used in conjunction with various embodiments of the present invention;
[0014] FIG. 4 generally depicts the vacuum device of FIG. 3 in a representative operational configuration and environment;
[0015] FIG. 5 generally illustrates another vacuum device that may be used in conjunction with various embodiments of the present invention.
[0016] Elements in the Figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the Figures may be exaggerated relative to other elements to help improve understanding of various embodiments of the present invention. Furthermore, the terms “first”, “second”, and the like herein, if any, are generally used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. Moreover, the terms “front”, “back”, “top”, “bottom”, “over”, “under”, and the like, if any, are generally employed for descriptive purposes and not necessarily for comprehensively describing exclusive relative position or order. Any of the preceding terms so used may be interchanged under appropriate circumstances such that various embodiments of the invention described herein, for example, are capable of operation in orientations and environments other than those explicitly illustrated or otherwise described.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0017] The following descriptions are of exemplary embodiments of the invention and the inventor's conception of the best mode and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following Description is intended to provide convenient illustrations for implementing various embodiments of the invention. As will become apparent, changes may be made in the function and/or arrangement of any of the elements described in the disclosed exemplary embodiments without departing from the spirit and scope of the invention.
[0018] Typically, the pressure inside a vacuum sealed food container (e.g., “jar”) is much lower than atmospheric pressure. It will be appreciated that as used herein, the term “jar” may be understood to include or alternatively reference a bottle, a lid, a cap or any other containment volume or containment volume closure that may be suitably adapted to provide at least a partial vacuum seal of the internal volume disposed therein.
[0019] The lid of a jar typically has a large force pressing the sealing surface to the lip of the jar due to a differential pressure between the external environment and the internal containment volume. This force on the lid translates into friction on the sealing surface. The equation describing this friction force ƒ may be given as:
ƒ=μF normal
where μ is the coefficient of friction of the lid seal and the lip of the jar, for instance, and F normal is the normal force created by the vacuum pressure on the lid closure.
[0020] As generally depicted for example in FIG. 1 , a representative and exemplary embodiment of the present invention provides a vacuum release device that is adapted to penetrate the lid closure of a jar with a small diameter penetrator 100 , leaving a small hole. The resulting hole allows the pressure inside the jar to equalize with atmospheric pressure, thereby substantially eliminating the normal force on the jar lid closure, and therefore the associated vacuum-induced friction forces at the sealing surface.
[0021] The penetrator 100 point may be placed perpendicular and substantially normal to the top surface of the lid closure. The housing 120 is pressed down (e.g., toward the lid closure), which in turn forces the penetrator 100 and striker 130 up, thus pre-loading the load spring 110 . The load spring 110 is compressed by the upward movement of the striker 130 . When the trigger pin 180 comes into contact with the trigger block 190 , the trigger pin 180 is forced into a set hole in the penetrator 100 . The trigger pin 180 has a hole of a larger diameter than the striker 130 . The movement of the trigger pin 180 aligns the trigger pin hole and the striker 130 . The pre-loaded load spring 110 forces the striker 130 through the trigger pin hole to strike the penetrator 100 . This in turn forces the penetrator 100 through the lid closure.
[0022] The light return spring 150 forces the penetrator 100 down until the penetrator 100 contacts the penetrator down stop 160 . The striker 130 and penetrator 100 are dimensionally configured such that the trigger spring 140 forces the trigger pin 180 to set against the striker set pin 170 , which is inside the trigger pin hole. The arrangement of the trigger pin hole and the striker set pin 170 are such that the trigger pin 180 is retained within the penetrator 100 . This arrangement provides a ‘hair trigger’ that may be automatically reset against the trigger block 190 each time the jar lid vacuum release device is used.
[0023] In an alternative exemplary embodiment depicted in FIG. 2 for example, the penetrator 200 point may be placed perpendicular and substantially normal to the top surface of the lid closure. The housing 220 is pressed down (e.g., toward the lid closure), which in turn forces the penetrator 200 and striker 240 up, thus pre-loading the load spring 210 . The load spring 210 is compressed by the upward movement of the striker 240 . When the trigger pin 270 comes into contact with the trigger block 250 , the trigger pin 270 is forced into a set hole in the striker 240 . The trigger pin 270 generally has a hole of a larger diameter than the striker 240 . The movement of the trigger pin 270 aligns the trigger pin hole and the striker 240 . The pre-loaded load spring 210 forces the striker 240 against the striker down stop 230 to strike the penetrator 200 . This in turn forces the penetrator 200 through the lid closure.
[0024] The light return springs 260 force the penetrator 200 down until the penetrator 200 contacts the penetrator down stop 280 . The striker 240 and penetrator 200 are dimensionally configured such that the trigger spring 290 forces the trigger pin 270 to set against the striker set pin 295 , which is inside the trigger pin hole. The arrangement of the trigger pin hole and the striker set pin 295 are such that the trigger pin 270 is retained within the penetrator 200 . This arrangement provides a ‘hair trigger’ that may be automatically reset against the trigger block 250 each time the lid closure vacuum release device is used.
[0025] Once a jar is opened, the food contained therein is exposed to the atmosphere. The jar evacuator representatively illustrated for example in FIGS. 3 and 4 , is a hand-held vacuum pump 300 , 310 combined with a substantially laminar seal 410 on the surface 420 of lid closure 400 that may be used to reseal the jar.
[0026] Without a seal closure 410 , the hole 430 may pose a problem with respect to food spoilage. A metalized plastic sheeting with integral PST (pressure sensitive tape) may be provided to re-establish a contiguous sealing lid. Metalized plastic sheeting with integral PST may be provided on a roll or package with easy dispensing, much like conventional cellophane tape. Additionally, metalized plastic sheeting with integral PST is typically FDA approved and may be used to provide a food grade seal for the hole 430 .
[0027] In general, the hole 430 in the lid closure allows for the use of a vacuum resealing device to be applied. For example, a small hole 430 is placed in the lid 400 of the jar or container to be resealed in a fashion substantially conforming to the method described vide supra. A small, thin laminar valve 410 is generally placed over the hole 430 . The valve may have a small amount of PST on one side or corner 440 , to attach it to the lid, but typically not directly over the hole 430 .
[0028] The hand-held vacuum pump 300 , 310 is placed over the hole 430 and valve 410 and the pump 300 , 310 operated to evacuate the area under the pump 300 , 310 and the inside of the containment volume. Lower pump housing collar 330 may be additionally adapted to provide a sealing surface 340 (e.g., gasket, etc.) between the vacuum pump lower housing 300 and the lid 400 .
[0029] As the pump operating handle 320 is moved up with respect to lower pump housing 300 , the pumping column 310 is disposed within the interior volume 350 of lower pump housing 300 in a manner that draws a partial vacuum in interior volume 350 . Valve 410 lifts up as air is removed from the jar. The differential pressure experienced across the valve 410 forces the valve 410 down on top of the hole 430 , thereby providing a vacuum seal in the containment volume.
[0030] The hole 430 in the lid 400 and the valve 410 allow for simple release of the vacuum by lifting the valve 410 , for example by hand, and re-evacuation by the methods described vide supra.
[0031] Laminar valve seal 410 may comprise a small flexible flap of rubber, silicone, or any other type of sealing material, whether now known or otherwise hereafter described in the art, which has suitable flexibility and sealing properties. The valve 410 may have one end coated in PST or other adhesive. Any adhesive material may be used, whether now known or otherwise hereafter described in the art, which has suitable adhesive properties to adhere the laminar valve or seal 410 to the lid surface 420 thereby holding the valve or seal 410 in position. Alternatively, conjunctively or sequentially, laminar valves/re-valves/seals may be used and adapted to comprise a substantially integrated feature of a lid closure designed for engagement with a jar. In such an embodiment, the jar seal may be release and re-sealed prior to subsequent storage.
[0032] FIG. 5 generally depicts an alternative exemplary embodiment in accordance with the present invention that provides the ability to apply an adhesive seal 530 over the puncture hole 560 in the lid 570 of the jar while achieving or otherwise maintaining a vacuum in the jar. Plunger 520 is generally suspended inside the piston/handle assembly of the vacuum pump and is typically displaced with the movement of the piston as the pump is operated. Seal 530 allows substantially linear movement of plunger 520 within the piston while maintaining a vacuum pressure between the vacuum body (e.g., jar lid 570 ) and the vacuum piston. Spring 500 generally retains plunger 520 in a position such that the distal end of plunger 520 does not typically contact lid surface 570 until the top of plunger 520 is depressed. Alternatively, conjunctively or sequentially, plunger 520 may be suitably adapted to automatically descend and apply seal 530 in correspondence to the vacuum force experienced by plunger 520 .
[0033] Metalized plastic or other suitable material may be provided to accomplishing sealing of the contents of the vessel from the exterior environment. In a representative application, seal 530 will generally seal hole 560 after a vacuum has been drawn on, for example, a jar. Typically seal 530 will comprise a sealing element and generally not a “valve” element.
[0034] To secure seal 530 to plunger 520 prior to deployment, a double-sided tape or pressure sensitive tape material may be employed wherein the side of seal 530 attaching to the bottom of plunger 520 (i.e., the upper side 540 ) is generally less “sticky” than the side attaching to the top of lid surface 570 (i.e., the lower side 550 ). Various other means, whether now known or otherwise hereafter described in the art, may be employed for mechanically releasable attachment of seal 530 to plunger 520 wherein said attachment does not substantially impede application of seal 530 to lid surface 570 .
[0035] In operation, seal 530 may be attached to the bottom surface of plunger 520 within the vacuum tool generally depicted in FIG. 5 . The vacuum tool may then be placed over a lid surface generally encompassing the hole 560 in the lid surface 570 . The vacuum pump may then be operated to at least partially evacuate air for the vessel (i.e., jar) thereby establishing a pressure differential (e.g., vacuum). While retaining the seal of the vacuum tool to the lid surface 570 , plunger 520 may be depressed in order to apply seal 530 over the hole 560 in the vessel's lid 570 .
[0036] In general, the term “valve” may be understood to reference a configuration whereby at least a portion of the valve may be at least partially displaced for at least one of substantially equilibrating the interior pressure of a containment volume with the exterior pressure, or at least a portion of the valve may be at least partially displaced during the action of establishing a pressure differential between the interior pressure and the exterior pressure of a containment volume. Alternatively, conjunctively or sequentially, the term “seal” may be generally understood to reference a configuration whereby a majority portion of the seal is substantially securely adhered to the surface of a containment lid around or about a vent opening for the purpose of establishing a contiguous seal without necessarily being adapted for partial displacement in accordance with the “valve” embodiment described vide supra.
[0037] In the foregoing specification, the invention has been described with reference to specific exemplary embodiments; however, it will be appreciated that various modifications and changes may be made without departing from the scope of the present invention as set forth in the claims below. The specification and Figures are to be regarded in an illustrative manner, rather than a restrictive one and all such modifications are intended to be included within the scope of the present invention. Accordingly, the scope of the invention should be determined by the claims appended hereto and their legal equivalents rather than by merely the examples described above. For example, the steps recited in any method or process claims may be executed in any order and are not limited to the specific order presented in the claims. Additionally, the components and/or elements recited in any device claims may be assembled or otherwise operationally configured in a variety of permutations to produce substantially the same, result as the present invention and are accordingly not limited to the specific configuration recited in the claims.
[0038] Benefits, other advantages and solutions to problems have been described above with regard to particular embodiments; however, any benefit, advantage, solution to problems or any element that may cause any particular benefit, advantage or solution to occur or to become more pronounced are not to be construed as critical, required or essential features or components of any or all the claims.
[0039] As used herein, the terms “comprises”, “comprising”, or any variation thereof, are intended to reference a non-exclusive inclusion, such that a process, method, article, composition or apparatus that comprises a list of elements does not include only those elements recited, but may also include other elements not expressly listed or inherent to such process, method, article, composition or apparatus. Other combinations and/or modifications of the above-described structures, arrangements, applications, proportions, elements, materials or components used in the practice of the present invention, in addition to those not specifically recited, may be varied or otherwise particularly adapted by those skilled in the art to specific environments, manufacturing specifications, design parameters or other operating requirements without departing from the general principles of the same. | An exemplary system and method for providing and releasing a vacuum seal is disclosed as comprising inter alia: puncturing a portion of a lid closure with a penetrator device; actuating a vacuum pump to remove at least a portion of atmospheric gas from inside the containment vessel via the puncture hole; and sealing the puncture with a laminar valve or thin film held in place with PST or other suitable adhesive. Disclosed features and specifications may be variously controlled, adapted or otherwise optionally modified to improve release and/or re-establishment of a vacuum seal for any application or operating environment. Exemplary embodiments of the present invention generally provide for quick, easy and safe opening and resealing of vacuum packaged containers for food products. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an air traffic control system, and in particular, to a technology capable of traceback and isolation of flight data packet transferred between a flight data processing system and a flight data terminal through an aeronautical telecommunication network that is a backbone network for building a next-generation air traffic control system.
[0003] 2. Description of the Related Art
[0004] An aeronautical fixed telecommunication network (AFTN), which is a backbone network of an air traffic control system, is an X.25-based closed type telecommunication network that includes a separate network address system, router equipment, etc., for the aeronautical fixed telecommunication network. The aeronautical fixed telecommunication network has lower security risk from the inside and outside as compared with an open type telecommunication network. However, the aeronautical fixed telecommunication network has problems in that manufacturing companies avoid the development of products such as a router and a dedicated line in an X.25 format, the maintenance cost is increased, it is difficult to accommodate surging air data, and it is difficult to support communication, navigation surveillance/air traffic management (CNS/ATM) of a next-generation air traffic control system, etc.
[0005] The aeronautical telecommunication network (ATN) is a next-generation digital telecommunication network that integrates and operates wired/wireless air telecommunication networks built and operated by each airline or airport-related agency according to the recommendation of international civil aviation organization (ICAO) in order to solve the problems occurring in the existing aeronautical fixed telecommunication network.
[0006] The aeronautical telecommunication network is recommended so that it includes common interface services based on ISO OSI reference models and telecommunication services and applications allowing a data subnetwork for ground, air-to-ground, and airbone electronic devices to be mutually operated by adopting protocols and is designed to support the CNS/ATM.
[0007] However, according to the “review, of web application security and intrusion detection in air traffic control systems” published in 2009, about 3000 or more weak points were highlighted in the web application for the air traffic control as a result of checking the air control system of U.S. to which a portion of the aeronautical telecommunication network is applied.
[0008] In other words, although the aeronautical telecommunication network is an efficient telecommunication network to support the next-generation air traffic control system, it is expected that a serious problem will occur in providing safe aircraft control unless efficient security measures using an interface such as web applications to support a new air traffic control system are prepared.
[0009] Therefore, an urgent need exists for a flight data packet managing method capable of more safely controlling an aircraft based on the aeronautical telecommunication network.
SUMMARY OF THE INVENTION
[0010] The present invention proposes to solve the above problems. It is an object of the present invention to increase security, reliability, and availability for an air control system by monitoring a flight data packet transferred between a flight data processing system and a flight data terminal that are connected through an aeronautical telecommunication network and when a high-risk flight data packet is generated, tracebacking high-risk flight data and isolating a source of the high-risk flight data in the aeronautical telecommunication network.
[0011] Further, it is another object of the present invention to efficiently traceback a high-risk flight data packet transmission path by using agent information generated by routers configuring an aeronautical telecommunication network.
[0012] In order to achieve the above object, according to an embodiment of the present invention, there is provided a method of traceback and isolation of high-risk flight data packet, including: monitoring, by a flight data packet monitoring unit, whether a high-risk flight data packet is generated in flight data packets transmitted to a flight data processing apparatus; tracebacking a transfer path for the high-risk flight data packet on a network by a path tracebacking unit when the high-risk flight data packet is generated; and isolating, by an isolation processing unit, a flight data terminal transmitting the high-risk flight data packet to the transfer path in an aeronautical telecommunication network.
[0013] The method of traceback and isolation of high-risk flight data packet may further include generating agent information by allowing a router relaying the transmission of the flight data packets to use the flight data packets.
[0014] The agent information may include a previous IP address field, a current IP address field, a next IP address field, and a masking or not field. The tracebacking the transfer path may traceback the transfer path by using the agent information.
[0015] The tracebacking the transfer path may include: collecting the agent information including the masking or not field indicating that the flight data packet is masked; and forming the transfer path using the collected agent information.
[0016] The forming the transfer path may form the transfer path by connecting IP addresses of the previous IP address field and the next IP address field corresponding to the collected agent information.
[0017] The isolating the flight data terminal in the aeronautical telecommunication network may instruct the filtering the high-risk flight data packet by all the routers existing in the aeronautical telecommunication network and stop the transfer of all the data transferred from the IP corresponding to the flight data terminal.
[0018] According to another exemplary embodiment of the present invention, there is provided an apparatus of monitoring and tracebacking a flight data packet, including: a flight data packet monitoring unit that monitors whether a high-risk flight data packet is generated in flight data packets transmitted to a flight data processing apparatus; a path tracebacking unit that tracebacks a transfer path for the high-risk flight data packet on a network when the high-risk flight data packet is generated; and an isolation processing unit that isolates a flight data terminal transmitting the high-risk flight data packet to the transfer path in an aeronautical telecommunication network.
[0019] The apparatus of monitoring and tracebacking a flight data packet may further include an agent information collecting unit that collects agent information from routers configuring the aeronautical telecommunication network.
[0020] The agent information may include a previous IP address field, a current IP address field, a next IP address field, and a masking or not field.
[0021] The path tracebacking unit may form the transfer path by connecting IP addresses of the previous IP address field and the next IP address field corresponding to the collected agent information.
[0022] According to the embodiments of the present invention, it can isolate a risk such as a service stop due to the high-risk flight data packet generated in the air traffic control system based on the aeronautical telecommunication network and safely provide air traffic control service to the user.
[0023] Further, the present invention isolates only the flight data terminal transferring the high-risk flight data packet in the aeronautical telecommunication network, thereby making it possible minimize inconvenience to other users and improve the overall security of the air traffic control system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a diagram showing an air traffic control system based on an aeronautical telecommunication network according to an exemplary embodiment of the present invention;
[0025] FIG. 2 is a diagram showing an example of a flight data packet used in an air traffic control system shown in FIG. 1 ;
[0026] FIG. 3 is a diagram showing an example of agent information used in an air traffic control system shown in FIG. 1 ;
[0027] FIG. 4 is an operational flow chart showing a method of traceback and isolation of a high-risk flight data packet according to an exemplary embodiment of the present invention;
[0028] FIG. 5 is an operational flow chart showing an example of a step of tracebacking transfer path shown in FIG. 4 ; and
[0029] FIG. 6 is a block diagram showing a flight data packet monitoring and tracebacking apparatus according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] The present invention will be described below with reference to the accompanying drawings. Herein, the detailed description of a related known function or configuration that may make the purpose of the present invention unnecessarily ambiguous in describing the present invention will be omitted Exemplary embodiments of the present invention are provided so that those skilled in the art may more completely understand the present invention. Accordingly, the shape, the size, etc., of the elements in the figures may be exaggerated for explicit comprehension.
[0031] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0032] FIG. 1 is a diagram showing an air traffic control system based on an aeronautical telecommunication network according to an exemplary embodiment of the present invention.
[0033] Referring to FIG. 1 , the air traffic control system includes an air control system 110 , an aeronautical telecommunication network (ATN) 120 , and a flight data terminal 130 .
[0034] The air control system 110 may include a flight data processing apparatus 111 , a subsystem for air control 112 , a flight data packet monitoring and tracebacking apparatus 113 , and a firewall 114 .
[0035] The aeronautical telecommunication network 120 includes a plurality of routers 142 , 143 , 144 , 145 , and 146 .
[0036] Each router 142 , 143 , 144 , 145 , and 146 is installed with an agent program for generating traceback information. Therefore, the router serves to form the transfer path of the flight data packet.
[0037] The air traffic control system including the flight data processing apparatus 111 and the flight data terminal 130 based on the aeronautical telecommunication network may configure one site.
[0038] The flight data processing apparatus 111 and the flight data terminal 130 may be connected to each other by a specific interface.
[0039] The flight data packet monitoring and tracebacking apparatus 113 may be positioned in the air control system 110 . In this case, the flight data packet monitoring and tracebacking apparatus 113 may exist as an independent separate apparatus and may exist as a portion of other apparatuses such as the flight data processing apparatus 111 or the subsystem 112 for air control, etc.
[0040] The flight data packet transferred through the flight data terminal 130 may be transferred to the flight data processing apparatus 111 via the routers 147 , 146 , 145 , 142 , and 141 and the firewall 114 .
[0041] In this case, the flight data packet monitoring and tracebacking apparatus 113 checks whether the transferred flight data packet is a high-risk flight data packet and when it is determined whether the flight data packet is the high-risk flight data packet, tracebacks the path through which the corresponding flight data packet is transferred by operating a tracebacking module to find out the flight data terminal 130 and isolates it from the aeronautical telecommunication network.
[0042] The agent program installed in each of the routers 141 , 142 , 143 , 144 , 145 , 146 , and 147 according to the present invention stores the routing information of the routed flight data packet in the database. In this case, the routing information may include a previous IP address, a next IP address, flight data packet contents, etc. In other words, the agent program may store the previous IP address, the next IP address, and the flight data packet contents for all the flight data packet transferred through the corresponding router and database them.
[0043] In addition, when the flight data packet monitoring and tracebacking apparatus 113 senses packets suspected as the high-risk flight data packet, the flight data packet monitoring and tracebacking apparatus 113 may request the agent information as the agent program installed in each of the routers 141 , 142 , 143 , 144 , 145 , 146 , and 147 . In this case, the flight data packet monitoring and tracebacking apparatus 113 may instruct a masking for the flight data packet suspected as the high-risk flight data packet, the agent program searches the routing information stored in the database to add the masking information indicating that the flight data packet is masked to the routing information when the routing information on the corresponding high-risk flight data packet is in the database, thereby making it possible to provide the flight data packet monitoring and tracebacking apparatus 113 . The agent program includes the masking information indicating that the flight data packet is not masked even when there is no routing information on the corresponding high-risk flight data packet, thereby making it possible to return the routing information.
[0044] In addition, when the agent program receives the masking request for the high-risk flight data packet from the flight data packet monitoring and tracebacking apparatus 113 , it can serve to isolate the routing for the flight data terminal transferring the corresponding packet.
[0045] The agent information generated in the agent program may be masking or not for the IP address of the corresponding router, the IP address of the previous router, the IP address of the next router, and the flight data packet.
[0046] When the flight data terminal 130 transfers the flight data packet whose contents are damaged, the flight data packet monitoring and tracebacking apparatus 113 senses the risk of the flight data packet transferred to the air control system 110 via the routers of the aeronautical telecommunication network 120 . The flight data packet monitoring and tracebacking apparatus 113 immediately instructs masking of the corresponding high-risk flight data packet to the agents installed in the router of the aeronautical telecommunication network and all the agents update the agent information and transfers the corresponding information to the flight data packet monitoring and tracebacking apparatus 113 . If there is no flight data packet to be masked in the flight data packet monitoring and tracebacking apparatus 113 , the unmasked information is transferred to the flight data packet monitoring and tracebacking apparatus 113 . The flight data packet monitoring and tracebacking apparatus 113 aligns the information collected from the agent as a key value for the masking or not, virtualizes the transfer path based on the previous/current/next IP addresses according to the masking or not, and tracebacks the position of the flight data terminal transferring the corresponding flight data packet. The isolation of the tracebacked flight data terminal instructs the isolation of the flight data packet to the agent that exists in the virtual path formed in the flight data packet monitoring and tracebacking apparatus 113 and the router in which the agent is installed isolates the transfer of the corresponding flight data packet.
[0047] The transfer path tracebacking according to the present invention may use the agent information configured by the agent to reconfigure the path on the network to which the high-risk flight data packet is transferred and then, filter the high-risk flight data packet in all the routers configuring the aeronautical telecommunication network and isolate the corresponding flight data terminal from the aeronautical telecommunication network.
[0048] FIG. 2 is a diagram showing an example of a flight data packet used in an air traffic control system shown in FIG. 1 .
[0049] Referring to FIG. 2 , the flight data packet includes a header field 210 , an address field 220 , and a flight data field 230 .
[0050] The header field 210 includes a flight data message header.
[0051] The address field 220 includes a unique identifier of the flight data terminal. In this case, since the unique identifier of the flight data terminal is different from the IP address and the flight data packet includes the unique identifier of the flight data terminal, not the IP address, such that the path tracebacking process of the present invention using the agent information is needed.
[0052] The flight data field 230 is a data field that is transferred to the flight data processing apparatus 111 .
[0053] FIG. 3 is a diagram showing an example of agent information used in an air traffic control system shown in FIG. 1 .
[0054] Referring to FIG. 3 , the agent information includes a previous IP field 310 , a current IP field 320 , a next IP field 330 , a masking or not field 340 , and a flight data packet field 350 .
[0055] The previous IP field 310 includes the IP address of the previous router where the agent is installed in the flight data packet transfer path.
[0056] The current field 320 includes the IP address field of the current router where the agent is installed in the flight data packet transfer path.
[0057] The next field 330 includes the IP address field of the next router where the agent is installed in the flight data packet transfer path.
[0058] The masking or not field 340 indicates whether the high-risk flight data packet determined by the system of the present invention is masked.
[0059] The flight data packet field 350 includes the flight data packet transferred through the aeronautical telecommunication network. For example, the flight data packet field 350 may include the flight data packet shown in FIG. 2 .
[0060] In this case, the previous IP field 310 , the current IP field 320 , and the next IP field 330 may be used for configuring the tracebacking path for the high-risk flight data packet.
[0061] The fields shown in FIGS. 2 and 3 are by way of example only and may be changed according to the request of the user or the provided service.
[0062] FIG. 4 is an operational flow chart showing a method of traceback and isolation of a high-risk flight data packet according to an exemplary embodiment of the present invention.
[0063] Referring to FIG. 4 , the method of traceback and isolation of high-risk flight data packet according to an exemplary embodiment of the present invention first receives the flight data packet (S 410 ).
[0064] Further, the method of traceback and isolation of high-risk flight data packet checks whether the received flight data packet is the high-risk packet (S 420 ).
[0065] In this case, the flight data packet may be transferred to the flight data processing apparatus.
[0066] As the determination result of step S 420 , when the flight data packet is determined as the high-risk packet, the method of traceback and isolation of high-risk flight data packet tracebacks the transfer path of the corresponding flight data packet on the network (S 430 ).
[0067] After tracebacking the transfer path on the network through step S 430 , the method of traceback and isolation of high-risk flight data packet isolates the flight data terminal transferring the high-risk flight data packet to the transfer path on the network from the aeronautical telecommunication network (S 440 ).
[0068] As the determination result of step S 420 , when the flight data packet is not determined as the high-risk packet, the method of traceback and isolation of high-risk flight data packet transfers the corresponding flight data packet to the flight data processing apparatus (S 450 ).
[0069] Although not shown in FIG. 4 , the method of traceback and isolation of high-risk flight data packet may further include generating agent information by allowing the router relaying the transmission of the flight data packets to use the flight data packets.
[0070] In this case, the agent information may include a previous IP address field, a current IP address field, a next IP address field, and a masking or not field.
[0071] In this case, step S 430 can traceback the transfer path by using the agent information.
[0072] Step S 440 instructs the filtering of the high-risk flight data packet by all the routers existing in the aeronautical telecommunication network and can stop the transfer of all the data transferred from the IP corresponding to the flight data terminal transferring the high-risk flight data packet.
[0073] FIG. 5 is an operational flow chart showing an example of the transfer path tracebacking of step S 430 shown in FIG. 4 .
[0074] Referring to FIG. 5 , the transfer path tracebacking step collects the agent information from the routers configuring the aeronautical telecommunication network (S 510 ).
[0075] In this case, the agent information may be generated/stored by the agent installed in each router.
[0076] Further, the transfer path tracebacking step aligns the agent information according to, the masking or not (S 520 ). That is, the transfer path tracebacking step separately classifies the agent information including the masking or not field indicating that it is masked.
[0077] In addition, the transfer path tracebacking step compares/analyzes the previous IP and the next IP of the agent information corresponding to the masking or not field indicating that it is masked (S 530 ).
[0078] The router and the link of the router are formed by the comparison/analysis of step S 530 to form the virtual path and the formed path becomes the transfer path of the high-risk flight data packet (S 540 ).
[0079] In other words, when steps S 530 and S 540 for all the masked agent information are repeated, the path on the network transferring the high-risk flight data packet may be configured.
[0080] FIG. 6 is a block diagram showing the flight data packet monitoring and tracebacking apparatus according to an embodiment of the present invention.
[0081] Referring to FIG. 6 , the flight data packet monitoring and tracebacking apparatus according to an exemplary embodiment of the present invention includes a flight data packet monitoring unit 610 , an agent information collecting unit 620 , a path tracebacking unit 630 , and an isolation processing unit 640 .
[0082] The flight data packet monitoring unit 610 monitors whether the high-risk flight data packet is generated in the flight data packets transferred to the flight data processing apparatus.
[0083] The agent information collecting unit 620 collects the agent information from the routers configuring the aeronautical telecommunication network. In this case, the agent information may be generated/stored by the agent installed in each router and may be a type of data shown in FIG. 3 .
[0084] The path tracebacking unit 630 tracebacks the transfer path for the high-risk flight data packet on the network when the high-risk flight data packet is generated.
[0085] In this case, the path tracebacking unit 630 uses the agent information generated by the routers configuring the aeronautical telecommunication network, thereby making it possible to traceback the transfer path.
[0086] In this case, the agent information may include a previous IP address field, a current IP address field, a next IP address field, and a masking or not field.
[0087] The path tracebacking unit 630 collects the masking information including the masking or not field indicating that it is masked and uses the collected masking information, thereby making it possible to form the transfer path. In this case, the path tracebacking unit 630 connects the previous IP address field corresponding to the collected masking information and the IP address corresponding to the next IP address field, thereby making it possible to form the transfer path.
[0088] The isolation processing unit 640 isolates the flight data terminal transmitting the high-risk flight data packet to the transfer path from the aeronautical telecommunication network.
[0089] The isolation processing unit 640 instructs the filtering of the high-risk flight data packet to all the routers existing on the aeronautical telecommunication network and stops the transfer of all the data transferred from the IP corresponding to the flight data terminal, such that it can isolate the flight data terminal transferring the high-risk flight data packet from the aeronautical telecommunication network.
[0090] The method of traceback and isolation of high-risk flight data packet and apparatus for the same according to the present invention as described above are not limited to the configuration and method of the embodiments as described above, but the embodiments may be configured by selectively combining all the embodiments or some of the embodiments so that various modifications can be made. | Disclosed is a method of traceback and isolation of a high-risk flight data packet and an apparatus for the same. The method of traceback and isolation of a high-risk flight data packet includes monitoring, by a flight data packet monitoring unit, whether a high-risk flight data packet is generated in flight data packets transmitted to a flight data processing apparatus; tracebacking a transfer path for the high-risk flight data packet on a network by a path tracebacking unit when the high-risk flight data packet is generated; and isolating, by an isolation processing unit, a flight data terminal transmitting the high-risk flight data packet to the transfer path from an aeronautical telecommunication network. The present invention can increase the security, reliability, and availability of the air traffic control system and can be performed without stopping the allocation of services to authenticated users of the air traffic control system. | 7 |
This is a continuation of application Ser. No. 385,423, filed Aug. 28, 1973, now abandoned.
FIELD OF THE INVENTION
This invention relates to a single seed drilling machine having a drum rotatable about a substantially horizontal axis and disposed partly in or at a seed container, the interior of the drum being connected to a source of negative pressure and the drum having suction holes disposed at equal intervals on a circle.
DESCRIPTION OF THE PRIOR ART
Pneumatically operated single seed drilling machines are known in which individual seeds are held at suction holes by the existence of a pressure differential. For example, a single seed drilling machine is known (German Patent Application No. 1,457,873), in which a drum rotatable about a substantially horizontal axis extends into the seed container and has in its outer surface suction holes disposed equidistantly, each hole having an associated projection being arranged behind said hole in the direction of drum rotation. The space within the drum is connected through the drum spindle to a negative pressure source, so that upon movement of the suction holes through the container, at least one seed is held at each hole and is entrained as the drum rotates. In this known machine, the seeds at the suction holes are singled out by a stream of air directed parallel to the drum axis to blow off the excess seeds. Further, a scraper roll is provided which rotates in the opposite direction to the drum, its shape accommodating the projections on the drum.
Inside the drum is a blower tube which ends at the inside surface of the drum, and which, as the drum rotates, becomes successively aligned with the suction holes. This blower tube is connected to a compressed air source and its effect is that seeds are removed from the holes by the compressed air when a hole moves adjacent the blower tube. Close co-operation between the blower tube and the suction holes is achieved in that the tube is pressed against the inside surface of the drum by a spring.
In this known machine, disadvantages arise in that, in addition to a negative pressure source, it is also necessary to provide a compressed air source. Further, proper function of this machine pre-supposes that the blower tube co-operates at least substantially in sealing fashion with the individual suction holes. By reason of the relative movement between the fixed blower tube and the rotating drum, wear (promoted by dust, treatment medium and seed residues) occurs, so that, in time, it becomes necessary to change the affected parts. Also, this machine can only sow seeds of one size category since a seed larger than the projections is squashed by the scraper roller. If a seed is smaller, then several seeds can easily be allowed through each suction hole by the scraper roller. The stream of air which extends parallel to the drum to single out the seeds may at least partially blow away treatment medium present on the seeds, so that difficulties may arise in growing the sown seeds.
It is thus an object of the invention to reduce or avoid these disadvantages and to provide a relatively simple machine which operates substantially wear-free and at the same time provides for substantially accurate maintenance of the distance required between successive seeds deposited in a row and taken from any uncased, uncalibrated seed stock.
SUMMARY OF THE INVENTION
According to this invention there is provided a seed drilling machine wherein a rotatable plate with inner and outer surfaces closes a space which in use is at reduced pressure so as to hold seeds against the outer surface at suction holes arranged on a circle, and wherein interrupter means in the space engages the inner surface at the circle of holes and ejector means is adjacent the outer surface at the circle of holes and in the region of the interrupter means.
Also according to this invention, in a single seed drilling machine having a seed container, a drum partly in or on the container and rotatable about a generally horizontal axis, means to connect the interior of the drum to a source of negative pressure, and suction holes in the drum and disposed on a circle, there is provided the improvement wherein the suction holes are provided in a perforated plate closing the drum, the plate being accessible to the seeds and being disposed at right angles to the said axis, interrupter means within the drum engaging the inner surface of the plate at the lowest region thereof at the circle of holes, and ejector means engaging the outer surface of the plate at the lowest region thereof at the circle of holes and in the region of the interrupter means.
Thus, in the apparatus of the invention, a negative pressure is in use applied to the interior of the drum, sealing being against the spindle, that is, against the smallest available diameter. Therefore it is not necessary to seal the negative pressure with respect to the ambient pressure at high relative speeds, so that the main cause of wear in the known machines is avoided. Accurate deposition of seeds into the furrow is therefore not left solely to the effect of gravity, but is assured by the interrupter means engaging the inner surface of the perforated plate, in conjunction with the ejector means disposed at the outer surface of the perforated plate in the region of the interrupter means. The perforated plate can be connected to the drum in any desired manner.
Preferably the interrupter means is a roller of elastic material which runs on the inner surface of the perforated plate, in the region of the suction holes. As it runs over the inner surface, the roller can be deformed so that it penetrates partly into the individual suction holes and presses out the seed held on the outer surface of the plate at a hole. In addition to this mechanical effect, there is a sealing of that suction hole which is associated momentarily with the roller with respect to the negative pressure in the drum, so that there is no longer any pressure difference at the relevant seed which might otherwise hold it against the plate at the hole in question.
The roller surface may be frusto-conical and downwardly widening, the axis of the roller in extension passing through the centre of the perforated plate. This arrangement ensures that no relative movement occurs between the roller and the inner surface of the perforated plate, which movement might cause wear on the roller.
The roller may be mounted on an arm connected rigidly to the drum spindle. Alternatively the roller may be mounted on an arm which is pivotably connected to the drum spindle and is engaged by a spring mounted on the spindle, the outer end of which spring urges the arm towards the perforated plate. Both arrangement ensure that the roller is pressed adequately firmly against the perforated plate so that it can partially penetrate the suction holes.
The interrupter means may be a blocking plate the edge of which bears against the inner surface of the perforated plate in the region of the circle of holes, the blocking plate being rotatable about an axis which is slightly inclined to the drum axis and which has only a slightly larger diameter than the circle of holes. This interrupter means engages in the suction holes in the region of the ejection point to some extent and in addition ensures sealing of the relevant suction hole with respect to the negative pressure in the drum.
In many cases, it is advantageous to provide the edge of the blocking plate with a flexible or elastic coating on that side which is towards the perforated plate. The blocking plate or its coating can have projecting studs which, upon rotation of the drum with the blocking plate, engage in the suction holes to a greater or less extent.
The ejector means may have a guide edge which gradually, outwardly draws close to the circle of holes, passes beyond it, and terminates in a downwardly inclined path. This ejector means helps to force the seeds downwards in the ejection region and to impart a desired trajectory to them. The ejector means prevents a seed which has become fouled with the associated suction hole moving beyond the ejection point which would otherwise result in its being deposited in the wrong place.
The guide edge may be rounded at its edge which is close to the outer surface of the perforated plate. This rounding prevents foreign matter, for example hairs, which may be clinging to the seeds, penetrating the gap between the perforated plate and the scraper. At the same time, the rounding ensures that the hairs or other foreign matter cannot advance into the gap between the perforated plate and the ejector means.
The position of the ejector may be adjustable with respect to the circle of holes. This adjustability is important if it is intended to sow different types of seeds which are of considerably differing sizes.
There may be provided a scraper which rests against the outer surface of the perforated plate in the upper region, radially outside the circle of holes, this scraper being profiled step-like, and the effective surfaces of the steps, with increasing distance from the outer surface of the perforated plate being set back farther from the circle of holes. The effect of this arrangement is that in the different steps of the scraper, it is possible to engage beneath the generally more or less sphericial seeds, enhancing the effect of the scraper and virtually excluding the possibility of one suction hole holding more than one seed. At the same time, seeds which may be partially introduced into the suction holes cannot be sheared off on the outside of the perforated plate and so destroyed.
The cross-section of the scraper may be the segment of a circle, and the scraper may be of curved construction with a radius of curvature corresponding to the pitch circle radius of the circle of holes. Also in this way it becomes possible to engage beneath the seeds, whereby (in the direction of rotation) the successive steps of the scraper extend increasingly more closely to the circle of holes.
The scraper may have successive pairs of oppositely inclined steps, whereby in the direction of rotation, one step of a pair draws gradually closer to the circle of holes, while the other step in contrast falls back sharply. Therefore, on rotation of the perforated plate, the steps which gradually draw close to the circle of holes press excess seeds gradually and radially inwardly or downwardly, lifting them at least partly off the perforated plate, while the other steps fall back sharply with respect to the circle of holes.
The scraper may be adjustable relative to the perforated plate by being pivotable about an axis parallel to the drum axis. This adjustability is important if it is intended to sow with one machine different types of seeds which are of markedly different sizes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a first embodiment of single seed drilling machine, in which the blade is only indicated;
FIG. 2 is a section on the plane 2--2 of FIG. 1;
FIG. 3 is a section similar to FIG. 2, of a second embodiment in which substantially only the pivotable connection between the arm carrying the roller and the drum spindle is shown;
FIG. 4 is a section similar to FIG. 3 of a third embodiment which shows a blocking plate;
FIG. 5 is an elevation of part of a scraper co-operating with the perforated plate;
FIG. 6 is a section on the plane 6--6 of FIG. 5;
FIG. 7 is a detail elevation of the ejector co-operating with the perforated plate; and
FIG. 8 is a part section on the plane 8--8 of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, the first embodiment of the machine is intended for one seed furrow. A plurality of such single seed machines can be disposed in a row one beside another and may be carried by a tractor.
The single seed drilling machine has a substantially disc-shaped housing 1, formed on the upper portion of which is a seed hopper 2. The housing 1 has a hub part 3 (FIG. 2) in which is a tubular spindle 4. Extending through the hub part 3, and radially with respect to the spindle 4, is a screw 5 which has at its radially inner end a point 6 which engages the spindle 4, fixing the latter to the housing 1. Mounted on the spindle 4 is an inner race 7 of a ball-bearing 8 between the hub part 3 at the housing 1 and a radially outwardly projecting shoulder 9 on the spindle 4. An outer race 10 of the ball-bearing 8 is disposed in an axially extending bearing portion 11 of a cup-like or flanged wheel 12 and is secured in a bore 13 in the bearing portion 11 between a circlip 14 and the bottom 15 of the bore 13.
Mounted rigidly on the bearing portion 11 is a chain wheel 20 which can be driven by a chain (not shown), according to the speed at which the machine is moved.
Connected rigidly to the bearing portion 11 is a disc-shaped portion 21 of the wheel 12, which portion 21 in its radially inward zone extends as far as the spindle 4, where it has a seal 22 which separates the two sides of the disc-shaped portion 21 in air-tight manner at the outer surface of the spindle 4.
The wheel 12 also has a concentrically extending cylindrical portion 23 which, together with the disc-shaped portion 21, forms a drum 24 which is closed by a perforated plate 25 which is parallel to the disc-shaped portion 21. The perforated plate 25 is circular and at its edge 26 is rigidly connected to a threaded projection 27 which co-operates with a screwthread 29 on the outer surface 28 of the cylindrical portion 23, allowing a separable connection to be made between the cylindrical portion 23 and the perforated plate 25. To establish air-tight connection between the plate 25 and the portion 23, a sealing ring 30 is disposed in the edge of the portion 23 which is towards the perforated plate 25, as seen in FIG. 2.
Mounted on the end of the spindle 4 which projects from the housing 1, is a tube 36 which connects the bore in the spindle 4 to a negative pressure source (not shown). The spindle 4 carries at its inner end 31 a collar 32 which is secured on the spindle 4 by a clamping screw 33. Welded to the collar 32 is a radially extending arm 34 which carries a roller 35 at its outer end. The roller 35 includes a cylindrical thrust ring 40 and a soft rubber annular sheel 41 fitted thereon. The ring 40, by means of two dust-proof ball-bearings 42, is rotatable about a journal 43 rigidly connected to the outer end of the arm 34. In extension, the axis of the journal 43 being the axis of the roller 35 passes through the centre of the perforated plate 25. On its outer surface, the rubber shell 41 is frusto-conical such that the extensions of its generatrices also pass through the centre of the plate 25; thus the roller 35 is always in contact with the inside face of the perforated plate 25 along one generatrix.
Fitted centrally on the outside face of the perforated plate 25 is an agitator 44 which consists of a plate 45 resting directly on the outside face of the perforated plate 25 and rigidly connected thereto, as well as two webs 46 extending at right-angles to each other, which cross at the centre of the perforated plate 25 and which slightly project in axial direction from the plate 45.
Provided in the perforated plate 25 on a pitch circle, the diameter of which is a little less than the inside diameter of the cylindrical portion 23, are a number of equidistant cylindrically shaped suction holes 61, their axes in each case being parallel with the spindle 4. The diameter of each suction hole 61 should be such that even the smallest grains of the relevant seed stock cannot pass through it.
A cover 47 is hinged on the housing 1 so that it can pivot about a vertical axis 48 (FIG. 1). The cover 47 is spaced, as shown in FIG. 2, from the perforated plate 25, and downwardly approaches the perforated plate 25. When closed, the cover 47 has its upper edge 49 (FIG. 2) abutting an obliquely extending bottom plate 50 of the seed hopper 2. Connected to the inside surface of the cover 47 is a baffle 51 which constitutes a transition from the seed hopper 2 to a seed container 52 formed between the cover 47 and the perforated plate 25. At its end remote from the vertical axis 48, the cover 47 can be separably connected to the housing 1 by a pivoting connection 53, shown diagrammatically in FIG. 1.
On the inside of the cover 47 is a wall 54 which extends so close to the outside of the perforated plate 25 that, when the cover 47 is closed, it seals off the lower portion of the seed container 52 and reliably prevents seeds dropping from the container 52. As FIG. 1 shows, in the bottom part of the cover 47, starting from the right-hand edge of the cover in FIG. 1, the wall 54 has an almost horizontal portion 55 adjacent which, to the left, is a rising, obliquely extending portion 56 which merges into an arcuately extending portion 57. Adjacent to the right-hand end (FIG. 1) of the horizontal portion 55 is a marginal portion 58 extending close to the outside of the perforated plate 25 and, when the cover 47 is closed, adjacent the seed hopper 2 in the region of the pivoting connection 53. The seed container 52 formed by the cover 47 is thus defined by the marginal portion 58, the horizontal portion 55, the obliquely extending portion 56 and the arcuately extending portion 57. The right-hand upper part of the seed container 52 is open and a rectangular cut-out 59 (FIG. 1) in the cover 47 permits inspection of the perforated plate 25.
In its lower part, the cover 47 extends as far as the obliquely extending portion 56 of the wall 54 and forms a recess 60 where the perforated plate 25 is exposed. In this recess a rectangularly angled ejector (generally indicated by 65) engages the outside face of the perforated plate 25 and has, extending parallel with the plate 25, a guide portion 66, the bottom end of which is rounded off, FIG. 2. Adjacent the upper end of this guide portion 66, and virtually at right-angles to the perforated plate 25, is a connecting portion 67 which merges into an arm portion 68 extending on the outside of the cover 47. The arm portion 68 is connected to a knurled disc 70 having a pointer 69. This disc and pointer are turnable on a bolt 71 projecting outwardly from the cover 47 (FIG. 2) and which can be tightened in the desired position by a nut 72 on the bolt 71. The pointer 69 co-operates with a dial 73 on the cover 47.
Referring now to FIGS. 7 and 8, the guide portion 66 of the ejector 65 is shown on a larger scale than in FIG. 1, and forms a guide edge or path 74. Viewed in the direction of rotation of the perforated plate 25, this guide path 74 is composed of two portions of opposite curvature, the seed entrained by the perforated plate 25 reaching a first portion which has a curvature corresponding approximately to the curvature of the circle of holes 61, while the second portion which it reaches subsequently is curved arcuately downwardly, passing beyond the circle of holes and extending as a parabola. The roller 35 is disposed on the inside of the perforated plate 25 in the region of this guide path 74.
Referring again to FIG. 1, the cover 47 has a projection 75 at the top, extending to the left. Mounted in this projection 75 is a shaft 76 on which in the projection 75 a thrust lever 77 is fixedly secured. Rigidly connected to the shaft 76 is a pointer 78 which co-operates with a dial 79 on the outside of the projection 75. The shaft 76 also carries a positioning lever 80 on the end of which is a scraper 85 having a plane surface 86 which, when the cover 47 is closed, lies closely against the outside of the perforated plate 25, radially outside the holes 61. The scraper 85 has a step-like profile, as shown, adjacent steps being of opposite pitch. For example, the step 87 (first reached by a seed held on the perforated plate 25) gradually approaches the circle of holes, while the subsequent step 88 in contrast falls back sharply. The next step 87a again gradually approaches the circle of holes, extending more closely to the circle than the step 87. Then follows step 88a, which again falls back steeply. The situation is similar with the subsequent steps, although in the direction of rotation the steps 87 always extend closer to the circle of holes.
Those surfaces of the steps 87, 88 which are towards the circle of holes are such that, with increasing distance from the outside of the perforated plate 25, they recede increasingly further from the circle of holes. In consequence, the steps 87, 88 adjacent the outside of the plate 25 project farthest in the direction of the circle of holes and consequently engage beneath the seeds held on the plate 25.
Mounted on the projection 75 of the cover 47 is one end of a tension coil spring 89, the other end being connected to the positioning lever 80 to urge the lever 80 (FIG. 1) to turn anti-clockwise about the shaft 76. The axis of the spring 89 lies in a plane inclined to the perforated plate 25, so that the upper end of the spring 89 is farther behind the projection 75 than is its lower end. Thus the lever 80 and the scraper 85 are urged not only upwardly but also towards the plate 25.
Also on the projection 75 is a knurled screw 90 of which the end screwed into the projection 75 engages the thrust lever 77 and, upon screwing of the knurled screw 90 into the projection 75, pivots the thrust lever 77 and with it the scraper 85 clockwise against the action of the spring 89.
FIG. 1 shows a blade 91 needed for producing the furrow in which the seeds are to be sown.
The second embodiment (FIG. 3) differs from the first only in that the arm 34 carrying the roller 35 is not rigidly connected to the spindle 4 but is pivotable about a pin 95 mounted transversely of the spindle 4 and held by the collar 32. Close to its outer end, that side of the arm 34 which is towards the disc-shaped portion 21 is engaged by a leaf spring 96, the inner end of which is fixed to the collar 32.
The third embodiment (FIG. 4) differs from the other embodiments only in the construction of the interrupter element, which is in this case in the form of a blocking plate 98. This blocking plate 98 is rotatable about a disc axis 99 slightly inclined to the drum axis 4, and which is welded to the spindle 4 by a holder 100. The inclination of the disc axis 99 is such that the edge of the blocking plate 98, in the region of the holes 61, engages the lower portion of the drum 24 on the inside of the perforated plate 25. The diameter of the blocking plate 98 is therefore only slightly greater than the diameter of the circle of holes 61, so that there are virtually no relative movements between the perforated plate 25 and the blocking plate 98.
The edge of that side of the blocking plate 98 which is close to the perforated plate 25 has an elastic covering 101 which seals the relevant suction hole 61 with respect to the negative pressure in the drum 24, and also penetrates partially into the suction hole 61 and expresses the seed mechanically from it.
FIGS. 5 and 6 show another embodiment of scraper 105. In cross-section (FIG. 6) the scraper 105 is a segment of a circle and has a radius of curvature (FIG. 5) corresponding approximately to the pitch circle radius of the perforated plate 25. It has successive pairs of oppositely inclined steps 106, 107, the step 106 reached in the direction of rotation (to the left in FIG. 5) of the perforated plate 25 extending gradually closer to the circle of holes, while the next step 107 falls back sharply, as shown. The following pairs of steps are similarly arranged. As can be seen from FIG. 6, the scraper 105, in the immediate vicinity of the perforated plate 25, projects to the greatest extent towards the circle of holes and can thus engage beneath seeds at the holes 61.
OPERATION
Seed passes into the seed container 52 from the hopper 2. If the drum 24 is connected to a negative pressure source (not shown) and if the chain wheel 20 is driven according to the speed at which the machine is advanced over the ground, then seeds are applied against the suction holes 61 in the plate 25 and, as the plate rotates, they are entrained by the holes, and in some cases more than one seed may cling to each hole 61. Those suction holes 61 which carry seeds now pass into the zone of influence of the scraper 85 or 105, whose position can be adjusted by the knurled wheel 90 so that only one seed is allowed to remain at each suction hole 61, the diameter of the holes being of course less than the diameter of the smallest seed. The thus singled out seeds are now moved on until their radilly inward sides are each engaged by the guide path 74 of the ejector 65, so that the seeds are pressed gradually, radially outwards. This action is assisted in that as a rule during the action of the ejector 65 on a seed, the associated suction hole 61 is masked on the inside of the perforated plate 25 by the interrupter element, e.g. the roller 35 or the blocking plate 98, so that the seed is no longer held by the negative pressure in the drum 24. Further, the interrupter element partly projects into the relevant hole 61 so as to express the seed which is partly inserted held in the hole 61. The trajectory of deposition of the seed into the furrow is determined, independently of the weight of the seed and the peripheral speed of the perforated plate 25, by the guide path 74. Delayed deposition of seed is not possible, so that the distance between the adjacent sown seeds is generally constant.
If it is intended to use the machine for different seed in which the individual seeds are of dimensions other than those previously used, then after the cover 47 has been opened, the perforated plate 25 can be exchanged for a different plate 25 having appropriate sized holes 61; the scraper and the ejector element are adjusted appropriately. | A single seed drilling machine has a rotatable drum the interior of which is connected in use to a source of reduced pressure. The drum is closed by a plate which has a circle of suction holes, so that seed can be held at the holes against the outer surface of the plate. Within the drum an interrupter device engages the plate to close a hole in the lowest region of the plate. Adjacent that hole, outside the plate, is a seed ejector device. Thus in the lowest region of the rotatable plate, the suction holding seed at a hole is temporarily rendered ineffective, at which time the seed is directed away from the plate by the ejector device. | 0 |
BACKGROUND OF THE INVENTION
The most widely used on-site wastewater treatment systems for individual households have traditionally been either septic systems or aerobic treatment units. Septic systems generally include a septic tank followed by a leaching tile field or a similar absorption device located downstream, but physically on-site of the individual residence. The septic tank allows for larger/heavier solids in the sewage to settle out within the tank, while anaerobic bacteria partially degrade the organic material in the waste. The discharge from the septic tank is further treated by dispersion into the soil through any number of soil absorption devices, such as a leaching tile field, whereby bacteria in the soil continue the biodegradation process.
The conventional septic system is typically a flow-through system. The septic tank and the tile field are positioned so that sewage is carried out of the residence and through the treatment system by gravity and hydraulic displacement. As a flow-through system, the tank relies on sufficient hydraulic capacity to slow the velocity of the flow and allows settling of the solids to take place. Unfortunately, as the settable solids accumulate in the bottom of the tank, they displace the beneficial tank volume, effectively increasing the velocity of flow through the tank and decreasing the efficiency of solids removal. Also, as a flow-through system, the velocity of the flow through the tank and the related efficiency of solids removal by gravity are dependent upon the volume and frequency of the incoming sewage. A lower volume and rate of incoming sewage flow allows for greater gravity separation and removal efficiency. Higher volumes and rates of flow therefore decrease gravity settling and solids removal efficiency. Over the course of time, an increasing in volume of organic material is discharged from the tank (due to decreasing removal efficiency) until the total volume of solids discharged over the life of the system exceeds the capacity of the downstream soil absorption system (leaching tile field) to accomplish further treatment. The soil absorption system will then retain solids and become plugged, thereby causing a back-up of sewage into the home. In this situation, the downstream soil absorption system is considered failed. Rejuvenation of a failed soil absorption system is not technologically feasible. Therefore, the downstream soil absorption system or other downstream device must be replaced or a new downstream device installed. However, even if sufficient land area is available toward the installation of a new downstream device, such can be accomplished only at considerable cost and inconvenience. Typically, heavy construction equipment is required to excavate and install any new replacement leaching tile field (a commonly used soil absorption system), or a similar device. This is much more inconvenient and costly then at the time of installation of the original treatment system. Construction equipment operating around an occupied residence frequently requires considerable destruction of hundreds of square feet of existing sod or lawn, moving fences, trees or recreational equipment, and creating a hazard for individuals, particularly smaller children.
Most aerobic treatment units are also flow through systems. Unlike septic tanks, aerobic treatment units perform primary (anaerobic) treatment and secondary (aerobic) treatment within the confines of the system. This arrangement provides a much higher degree of treatment within a relatively small area. As traditional aerobic treatment units are designed for a much higher removal of solids and organic compounds than anaerobic treatment units, a downstream device is frequently not required or is severely diminished in size compared to one which would be required downstream of a septic tank. In a traditional aerobic treatment unit, the first stage of the process is called pretreatment and provides for anaerobic treatment very much like that provided by a septic tank. A separate, isolated pretreatment chamber contains sufficient hydraulic capacity to slow the velocity of the flow somewhat and allows the settling of some of the solids to take place. Anaerobic bacteria partially degrade the organic material in the waste. As a flow through system, the contents of the pretreatment chamber (partially treated waste) are displaced by incoming sewage, and are transferred to the aeration chamber or biological reactor.
Within the aeration chamber, air is introduced in controlled amounts creating a proper environment for the development of a number of types of aerobic bacteria. The aerobic bacteria maintain a higher metabolic rate than anaerobic bacteria, which causes them to readily consume the organic material contained in the pretreated sewage. Prior to discharge of this flow through system, the aerobic bacteria (commonly called activated sludge) must be separated from the treated liquid. If the activated sludge particles are allowed to exit the system, two problems occur. First, the activated sludge would not be available to treat additional incoming sewage. As the system is operated on a continuing basis, the cultured bacteria need to be retained for future use. Secondly, if the activated sludge is allowed to be discharged from the system, the organic nature of the sludge would be considered a pollutant if returned directly to the environment.
Commonly, the activated sludge is separated from the treated liquid by allowing the solids to settle out in a gravity clarifier. In a flow through system, the contents of the aeration chamber containing the activated sludge are hydraulically displaced to the clarifier by partially treated liquid entering from the pretreatment chamber. Once in the gravity clarifier, quiescent conditions allow the activated sludge to slowly settle to the bottom of the chamber while the treated liquid is discharged from the system near the top of the chamber. The clarifier relies on having sufficient hydraulic capacity to slow the velocity of the flow through the chamber and thereby allows the activated sludge solids to settle to the bottom. The settled sludge at the bottom of the clarifier is returned, by various means, to the aeration chamber. This return prohibits the clarifier from accumulating a large volume of solids and thereby reducing the efficiency of solids separation. However, as a flow through system, the settling efficiency of the clarifier is dependent also on the volume and frequency of the incoming sewage flow.
From the foregoing, it is clearly seen that the efficient and long-term operation of a flow through septic system or a flow through aerobic treatment unit is dependent on eliminating surges and maintaining a uniform, consistent rate of flow through the system. Unfortunately, a uniform, consistent rate of flow through a residential wastewater system is not commonly achieved. Modern homes are furnished with many water using appliances that generate large volumes of sewage flow in compressed periods of time. Wastewater from washing machines, dishwashers, hot tubs, spas, and similar appliances tend to be high in volume and discharge within a short period of time. These concentrated hydraulic surges disrupt the quiescent environment of septic tanks or aerobic treatment units, reducing efficiency of the gravity settling process. This effect causes partially treated waste or biological solids to be discharged to a downstream soil absorption system or other downstream treatment device resulting in premature failure, or causes biological solids to be returned to the environment as a pollutant.
SUMMARY OF THE INVENTION
An object of the present invention is to enhance the operation of new or existing septic tanks or aerobic treatment units to prohibit the discharge of partially treated waste or other organic solids. By installing a novel wastewater treatment unit of the present invention downstream of a new or existing septic tank or an aerobic treatment unit, but upstream of a soil absorption system, device or a discharge point, the discharge of partially treated waste or other organic solids is substantially totally precluded. In particular, the wastewater treatment unit of the present invention is of a relatively compact size and its installation as aforesaid can be accomplished with minimum disturbance to existing yards, landscaping or home sites whose downstream soil absorption system is being newly installed or has been installed for a time and is failing. Even if the downstream treatment system has not failed, the installation of the wastewater treatment unit of the present invention provides enhanced performance benefits to new or previously installed residential wastewater treatment systems at a minimum of cost, effort and installation time. By thus installing the wastewater treatment unit of the present invention into or as part of a residential wastewater treatment system, an increase in the serviceability of the latter is automatically achieved. As the total volume of solids discharged by a secondary treatment system typically accumulate in the downstream soil absorption system or device, premature failure is common. Removal of accumulated solids from a failed or plugged soil absorption device is not technological feasible, but rejuvenation thereof can be achieved by the present invention in the sense that the wastewater treatment unit of the present invention can be installed upstream from the failed soil absorption system and will accumulate solids which can in turn be removed readily from grade thereby preventing solids from passing beyond the wastewater treatment unit to the failed soil absorption system. In this fashion the wastewater treatment unit of the present invention can rejuvenate wastewater treatment systems which have failed and, if installed prior to such failure, can extend the life thereof.
The latter objects are achieved by a novel wastewater treatment unit utilizing substantially the wastewater treatment mechanism disclosed in U.S. Pat. No. 5,264,120 granted on Nov. 23, 1993 which is housed in a settling and retention basin which collects solids from domestic wastewater discharge. The settling and retention basin includes an inlet and an outlet pipe or invert which are respectively connected to the discharge of a flow-through septic system or a flow-through aerobic treatment unit and a soil absorption system (leaching tile field) or any such other downstream treatment device. Wastewater enters the settling and retention basin and before being discharged therefrom passes through and is treated by a wastewater treatment mechanism (similar to that of U.S. Pat. No. 5,264,120 which is known in the trade as assignee's Bio-Kinetic® device) which contains three filtration zones, eight settling zones, 37 baffled chamber plates and 280 lineal feet of kinetic filtration, all of which dramatically reduce loading on downstream soil absorption systems. Moreover, within the Bio-Kinetic® device are settling zones which operate in conjunction with filtration and flow equalization to effectively retain BOD and solids which are removed from the flow stream. The Bio-Kinetic® device includes flow equalization ports arranged to manage daily flow variations and control flow through all upstream and downstream treatment processes, higher sustained flow ports which become operative under longer hydraulic surges and, finally, peak flow ports which operate under high, prolonged flow surges. Thus, under all three potential flow patterns, the solids can be settled by the Bio-Kinetic® device and retained in the settling and retention basin for subsequent removal from grade. Since the settling and retention basin has a normal capacity of 52 gallons below an outlet invert, normal liquid and solids retention capacity is quite high, but for special applications additional ring sections and riser sections can be added to dramatically increase the volume of the retention basin and allow water-tight installation at burial depths of up to 12 feet. However, an upper end of the settling and retention basin is at all times exposed above grade and is closed by a heavy duty access cover which permits the removal and cleaning of the Bio-Kinetic® device, the removal of solids from the settling and retention basin, and the re-installation of the Bio-Kinetic® device into the settling and retention basin for continued use. Thus, by installing the wastewater treatment unit of the present invention upstream of new or existing tile fields, sand filters, leaching fields, mounds, irrigation systems, constructed wet lands or any process that is biologically sensitive, hydraulically sensitive or difficult to replace, effective wastewater treatment is assured through the settling and storage of suspended solids, flow equalization, filtration and, if desired, chemical addition.
Thus, upon the installation of the wastewater treatment unit of the present invention immediately downstream of a new or existing septic tank or an aerobic treatment unit, the following advantages are achieved:
a) direct filtration and settling of treated wastewater or treated effluent,
b) beneficial flow equalization through all upstream and downstream treatment stages,
c) the addition of downstream chemicals via chemical feeders,
d) the enhancement of beneficial nitrification, and
e) the enhancement of beneficial de-nitrification.
With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view of a wastewater treatment system, and illustrates a wastewater treatment unit defined by a wastewater treatment mechanism (Bio-Kinetic® device) housed within a sectional solids settling and retention basin having an inlet connected to a conventional wastewater treatment plant and an outlet connected to a pipe leading to a downstream soil absorption system, such as an irrigation system, a leaching tile field, sand filters, etc. with an upper end of the settling and retention basin being accessible above grade upon the removal of an access cover.
FIG. 2 is an enlarged axial cross sectional view, and illustrates details of the wastewater treatment unit including compression clamps and associated seals or gaskets for securing tubular sections of the solids settling and retention basin to each other in a water-tight fashion, as well as securing the access cover to an uppermost tubular riser section of the solids settling and retention basin.
FIG. 3 is a perspective view of the wastewater treatment unit, and illustrates the exterior configuration thereof including a plurality of circumferential outwardly projecting ribs (inwardly opening valleys) and outwardly opening valleys (inwardly projecting ribs) and the access cover in its seated position.
FIG. 4 is an axial cross sectional view of the solids settling and retention basin of FIGS. 1 through 3, and illustrates three individual sections prior to being united together, a safety/surface guard or cover, and the access cover.
FIG. 5 is an axial cross sectional view through a one-piece molded solids settling and retention basin body immediately after the molding thereof, and illustrates shaded areas representing annular bands of waste material which can be selectively removed to form a segmented solids settling and retention basin and its associated safety/service guard or cover.
FIG. 6 is an axial cross sectional view of the segmented solids settling and retention basin body, and illustrates as exemplary the manner in which riser sections and/or ring sections can be interchangeably mated with each other.
FIG. 7 is another axial cross sectional view of another one-piece solids settling and retention basin body, and illustrates as exemplary eleven shaded areas representative of annular bands of waste material which can be selectively removed and discarded and from which a solids settling and retention basin can be formed of a variable number of riser and/or ring sections differing in height from those of FIGS. 5 and 6.
FIG. 8 is an axial cross sectional view of the solids settling and retention basin body of FIG. 7, and illustrates as exemplary all of the riser/ring sections telescopically united in one of several interchangeable arrangements.
FIG. 9 is a highly enlarged axial cross sectional view of the encircled portion of FIG. 2, and illustrates a compression clamp and seal assembly formed by an annular sealing gasket interposed between telescopic tubular sections of the sectional solids settling and retention basin and the compression clamp clamping the sections together in a water-tight fashion.
FIG. 10 is a top perspective view of the compression clamp, and illustrates opposite ends thereof, one end being in the form of a projecting tab or tongue having a plurality of elongated slots or openings, and the other end having an apertured wall or shoulder through which the tongue projects and a flexible locking tab having an inward projection which is received in one of the openings of the projecting tongue.
FIG. 11 is an enlarged fragmentary longitudinal cross sectional view of the compression clamp of FIG. 10, and illustrates details of the opposite ends thereof including the inward projection which seats in one of the openings of the tongue.
FIG. 12 is a fragmentary longitudinal cross sectional view of the compression clamp, and illustrates the compression clamp in its clamped position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A novel wastewater treatment system constructed in accordance with this invention is illustrated in FIG. 1 of the drawings and is generally designated by the reference numeral 10 .
The wastewater treatment system 10 includes a conventional wastewater treatment plant 11 connected by a discharge or outlet pipe 15 to a novel and unobvious wastewater treatment unit 20 of the present invention which is in turn connected by an outlet or discharge pipe 16 to a conventional soil absorption system or device 14 , such as an irrigation system, a leaching tile field, or the like. In conventional wastewater systems, the wastewater treatment plant 11 is connected directly by a sewer pipe to the soil absorption system 14 , obviously absent the wastewater treatment unit 20 , and as the total volume of solids are discharged and accumulate in the soil absorption system 14 , plugging and premature failure thereof is common. Removal of accumulated solids from a failed soil absorption system, such as the soil absorption system 14 , to rejuvenate the same is not technically feasible. However, in accordance with the novel method of this invention indefinitely extends the life of a new or rejuvenating such a failed soil absorption system 14 is accomplished by first excavating earth between the wastewater treatment plant 11 and the soil absorption system 14 . Thereafter the wastewater treatment unit 20 is installed as illustrated in FIG. 1 connected to the discharge of the wastewater treatment plant 11 through a newly installed outlet or discharge pipe 15 and by a newly installed outlet or discharge pipe 16 to the soil absorption system 14 .
As will be described more fully hereinafter, the wastewater treatment unit 20 removes accumulated solids discharged therein from the wastewater treatment plant 11 through the pipe 15 and thus the liquid discharge from the wastewater treatment unit 20 via the discharge pipe 16 is substantially solids-free. Solids so removed by the wastewater treatment unit 20 can be periodically removed therefrom and thereby the life of the soil absorption system 14 is extended or rejuvenated.
The wastewater treatment plant 11 is of a conventional construction and corresponds to the wastewater treatment plant disclosed in U.S. Pat. Nos. 5,207,896 and 5,264,120 granted respectively on May 4, 1993 and Nov. 23, 1993 to Norwalk Wastewater Equipment Company of Norwalk, Ohio, the assignee of the present invention. The specific details of the wastewater treatment plant of the latter-identified patents is incorporated herein by reference, but excluded from a clarifier or clarification chamber 17 of the wastewater treatment system 10 is the wastewater treatment mechanism (BioKinetic® device) and instead a conventional tubular tee T is connected to the pipe 15 .
The wastewater treatment unit 20 (FIGS. 1 and 2) of the present invention includes a sectional solids settling and retention basin 21 which preferably is a one-piece body molded from polymeric/copolymeric synthetic plastic material, as shall be described more fully hereinafter with respect to FIGS. 5 and 7 of the drawings, or can be constructed from a plurality of individual tubular sections, such as an upper tubular section or riser 22 , an intermediate or middle tubular section 23 and a lower tubular section 24 closed by an integral bottom wall 25 collectively defining the solids settling and retention basin 21 and a solids settling and retention chamber 26 thereof in which solids entering the chamber 26 through the discharge pipe 15 from the wastewater treatment plant 11 accumulate and can be periodically removed. The discharge pipe 15 is solvent-connected to the intermediate section 23 by a conventional schedule 40 PVC inlet coupling 18 and an associated seal (not shown), and the discharge pipe 16 is likewise connected to the intermediate tubular section 23 by another schedule 40 PVC outlet coupling 19 and an associated seal (not shown).
A wastewater treatment mechanism 50 (BioKinetic® device) which corresponds in most respects to the like numbered wastewater treatment mechanism of U.S. Pat. No. 5,264,120 is suspendingly supported within the solids settling and retention chamber 26 of the solids settling and retention basin 21 . The wastewater treatment mechanism 50 includes an outermost, substantially cylindrical, integral, one-piece molded filtering means, filtering media or filtering body 70 having a lower cylindrical filtering wall portion 72 of a smaller mesh than that of a upper cylindrical filtering wall portion 73 with an imaginary line 74 defining the line of demarcation therebetween. A solid wall 71 closes the bottom of the filtering means 70 and an upper end thereof terminates in a radially outwardly directed flange 75 .
The filtering body 70 includes a pair of diametrically opposite flow equalization means 85 defined by vertically aligned spaced flow equalization ports 81 , 82 and 83 progressively increasing in size upwardly and functioning in the manner set forth in U.S. Pat. No. 5,264,120. The sizes, spacing and function of the flow equalization ports 81 through 83 correspond to the same dimensions and functions as set forth in U.S. Pat. No. 5,264,120 which are incorporated hereat by reference.
A housing 90 having an open bottom is closed by an upper closure assembly 120 suspendingly support therein a baffle plate assembly 110 housing approximately three dozen baffle plates 99 . The latter unitized components corresponding substantially in structure and function to the like components of U.S. Pat. No. 5,264,120. The upper closure assembly 120 also includes a top wall or deck having a generally T-shaped channel (not shown) which discharges liquid into an outlet port 176 slidably telescopically received in a tubular discharge pipe 453 of a first flange coupler 451 which is vertically slidably received downwardly into and upwardly out of a generally U-shaped upwardly opening flange receiving coupler 456 having an opening (unnumbered) in fluid communication with the discharge pipe 16 . The couplings or coupler 451 , 456 permit the entire wastewater treatment mechanism 50 to be installed into and removed from the solids settling and retention basin 21 from above, as will be more apparent hereinafter.
Means 140 in the form of a dry tablet chlorination feed tube 141 for housing stacked chlorination tablets is carried by the upper closure assembly 120 as is dechlorinating means 180 in the form of a dry tablet dechlorination feed tube 181 for housing stacked dechlorination tablets, again as the latter structures and their functions are more fully specified in U.S. Pat. No. 5,264,120.
Resting atop the flange 75 of the wastewater treatment mechanism 50 is a removable moisture/vapor closure, cover or shield 55 defined by a one-piece molded polymeric/copolymeric body including a circular disc 51 , two tubular portions 57 , 58 projecting upwardly therefrom, and a tubular handle portion 59 spanning the tubular portions 57 , 58 . When positioned as illustrated in FIG. 2 of the drawings, the tubular portions 57 , 58 of the moisturelvapor cover 55 telescopically receive and stabilize the respective chlorination and dechlorination tubes 141 , 181 . Four equally circumferentially spaced holes (not shown) in the circular disc 51 receives fasteners, such as screws, which are threaded into like holes (also not shown) of the flange 75 to secure the moisture/vapor cover 55 to the flange 75 yet permit the rapid disassembly thereof by removing the screws (not shown). The purpose of the moisture/vapor cover or shield 55 is to prevent condensation from entering the wastewater treatment mechanism 50 .
Before specifically describing the three piece sectional solids settling and retention basin 21 of FIG. 2 which is defined by the upper, intermediate and lower tubular sections 22 through 24 , respectively, reference is made to FIG. 5 of the drawings which illustrates a one-piece hollow solids settling and retention body 30 molded by rotational molding, vacuum molding or injection molding from polymeric/copolymeric plastic material, such as corrosion resistant polyethylene. The hollow body 30 includes a tubular wall 31 having an upper end closed by an integral top wall 32 and a bottom end closed by an integral bottom wall 40 . A plurality of alternating internally projecting peripheral ribs 33 , 34 and inwardly opening valleys 35 , 36 are disposed substantially along the axial length of the tubular body 31 . The ribs 33 are of a substantially lesser internal diameter than the diameter of the ribs 34 and the valleys 35 are of a greater axial height and a greater diameter than the axial height and diameter of the valleys 36 . For the most part, the ribs and the valleys are arranged in the axial sequence 33 , 35 , 34 , 36 ; 33 , 35 , 34 , 36 ; etc. Within each such sequence of ribs and valleys, each rib 33 and its adjacent valley 35 are defined by a wall 37 common to each rib 33 and each valley 35 . Each rib 33 also includes an innermost cylindrical wall portion 38 and each valley 35 adjacent thereto includes an outermost cylindrical wall portion 39 .
Cut lines C 1 , C 2 define annular bands of scrap material or bands S 1 , S 2 and S 3 . By cutting along the cut lines C 1 , C 2 , the shaded annular bands S 1 , S 2 and S 3 are removed as scrap material and four tubular sections 41 , 42 , 43 and 44 are formed therefrom. Adjacent the top wall 32 , a somewhat wider circumferential band of scrap material S 4 can be removed when the hollow body 30 is severed along the cut lines C 1 , C 2 associated therewith. However, the hollow body 41 adjacent the top wall 32 terminates in two adjacent valleys 35 , 35 separated by a rib 34 . The purpose of this configuration is to not only create the tubular section 41 of essentially the identical contour as the tubular sections 42 , 43 and 44 , but also to form therefrom a generally concavo-convex wall 45 which can be rotated or flipped 180° from the position shown in FIG. 5 to that shown in FIG. 6 and thereby define a safety/surface guard, closure or cover 45 , preferably having a central hole 47 , for closing the solids settling and retention basin 21 , as is illustrated in its operative position in FIG. 2 and FIG. 6 of the drawings. However, upon the removal of the annular scrap 4 , the upper and lower edges (unnumbered) of the tubular sections 41 through 44 are identical to each other and a cylindrical wall portion 49 of each smaller valley 36 (FIG. 6) will telescopically seat within the remaining portion of the wall portion 39 of the larger valley 35 resulting in the telescopic nested supported relationship of the section 41 upon the section 42 , the section 42 upon the section 43 , and the section 43 upon the section 45 .
The hollow body 30 and the manner in which the scrap S 1 through S 4 are removed therefrom is merely exemplary of many different options which are available with respect to a particular installation of the solids settling and retention basin 21 between the wastewater treatment plant 11 and the soil absorption system 14 (FIG. 1 ). For example, the hollow body 30 (FIG. 5) is of the same diameter as the diameter (approximately 24″) of the solids settling and retention basin 21 but is only 60″ in height, as compared to the approximately 70″ total height of the solids settling and retention basin 21 . If only the band of scrap S 4 was removed, the remaining uncut tubular sections 41 through 44 of the hollow body 30 could be used in lieu of the axially shorter lower tubular section 24 (FIG. 2) of the solids settling and retention basin 21 thereby increasing the overall height, volume, and depth below grade or grade level GL thereof. As another example, by removing all bands of scrap material S 1 -S 5 , each of the tubular sections 41 through 44 can be individually utilized to increase the height or depth below grade GL or both of the solids settling and retention basin 21 by, for example, adding one of the sections 41 through 44 to the upper tubular section or riser 22 (FIG. 2) or to the lower section 24 as a so-called ring. Depending upon the number of removed scrap bands S 1 through S 5 , the axial heights thereof and the distances therebetween, each 60″ hollow body 30 can be utilized at the site of installation as might be required. In FIG. 5, if all scrap or scrap sections S 1 through S 5 were removed from the areas indicated, the upper and lower tubular sections 41 , 44 would each be approximately 12″ in axial length and the two middle tubular sections 42 , 43 would each be approximately 18″ in length. These sections could be used, as desired, to alter the overall height and depth above and/or below grade GL of the solids settling and retention basin 21 by 12″, 18″, 24″ etc. increments.
As another example of utilizing the hollow body 30 or sections thereof for particular installations, another identical hollow body 30 ′ is illustrated in FIG. 7 and the height thereof is also approximately 60″. However, in this case the hollow body 30 ′ includes eleven tubular scrap sections S 6 through S 16 which if all were removed would create ten tubular riser or ring sections 60 through 69 . The tubular sections 60 through 64 are each 6″ in axial height and the tubular sections 65 through 69 are each 3″ in axial height. Upon the removal of the cylindrical scrap material S 6 through S 16 , the tubular sections are shown in FIG. 8 telescopically united to each other, though such is merely exemplary and will not be used in actual practice. However, any 6″ tubular section 60 through 64 or any 3″ tubular section 65 through 69 can be utilized as need be to increase the height or depth above or below grade GL of the solids settling and retention basin 21 of FIG. 2 in lesser axial increments than provided by the 12″ tubular segments 41 , 44 and the 18″ tubular segments 42 , 43 of the body 30 of FIG. 5 . Accordingly, the hollow body 30 and the equivalent hollow body 30 ′ demonstrate the flexibility afforded the solids settling and retention basin 21 for a variety of site installations. It is, of course, within the scope of the invention to remove, for example, only the scrap material S 4 or S 6 of the respective hollow bodies 30 , 30 ′ and utilize the same as a single piece basin for other purposes, such as a pump housing. For example, a preferable single piece basin of approximately 70¼″ in height could be formed by molding either of the hollow bodies 30 , 30 ′ of an approximate axial length of 72″. Thereafter, the removal of only the narrow scrap section S 4 of the hollow body 30 or the scrap section S 6 of the hollow body 30 ′ would form a one-piece molded basin of approximately 70¼″. The latter basin excludes the flat wall 98 but would be provided with openings corresponding to the openings O, O′, though if used for a pump housing, the axial offset would be unnecessary.
Reference is made to FIG. 4 of the drawings which more specifically demonstrates details of the intermediate or middle tubular section 23 , as compared to the upper tubular section 22 , the lower tubular section 24 , or any of the tubular sections 41 through 44 and 60 through 69 . The major difference is an inwardly projecting rib 95 (FIG. 4) having an innermost cylindrical wall portion 96 of a diameter less than the diameter of the ribs 33 , 34 and an upper substantially horizontal wall portion 97 . The rib 95 projects inwardly substantially beyond the inward projection of any of the ribs 33 , 34 , and this allows the wastewater treatment mechanism 50 to be inserted into and withdrawn from the solids settling and retention basin 21 through the open upper end (unnumbered) upon the removal of the safety/service cover 45 and a separately fabricated heavy duty access cover 46 . Since the flange 75 (FIG. 2) of the filter media body 70 of the wastewater treatment mechanism 50 has a diameter substantially greater than the opening defined by the cylindrical wall portion 96 of the rib 95 , the flange 75 is underlyingly supported by the horizontal wall portion 97 of the rib 95 of the tubular section 23 . Additionally, there is a considerable annular gap G (FIG. 2) between the solids settling and retention basin 21 and the filter body 70 of the wastewater treatment mechanism 50 which allows the entire filter body 70 to be shifted radially to the left, as viewed in FIG. 2, to withdraw the outlet port 176 from the tubular discharge pipe 453 and vice versa incident to disassembly and reassembly, respectively, for purposes of installation, inspection servicing and/or cleaning.
The intermediate or medial tubular section 23 also includes two diametrically opposite relatively flat wall portions 98 having respective openings O, O′ (FIG. 2) preferably cut therein at the plant or factory immediately after the molding of the tubular section 23 or an entire one-piece basin 21 , as will be described more fully hereinafter. The inlet coupling 18 and the outlet coupling 19 are also preferably bolted (not shown) to the tubular section 23 at the factory. The axis Ao of the opening O (FIG. 2) is 1″ above the axis Ao′ of the opening O′ creating thereby an automatic and natural 1″ fall between the two openings O, O′.
The upper tubular section 22 (FIG. 2 ), normally termed a “riser” in the trade, is clampingly secured to the intermediate tubular section 23 by a compression clamp and seal assembly 100 . In FIG. 2 an identical compression clamp and seal assembly 100 clamps the medial tubular section 23 to the lower section 24 and, of course, identical compression clamp and seal assemblies 100 are utilized to connect other upper tubular sections or risers as desired above the medial tubular section 23 and like tubular sections, which are normally termed “rings” in the trade, when added beneath the middle tubular section 23 . A like compression clamp and seal assembly 100 also clamps the heavy duty access cover 46 to the upper tubular section or riser 22 with a peripheral edge (unnumbered) of the safety/service cover 45 being sandwiched between wall portions (unnumbered) of the uppermost rib 34 of the tubular section 22 and an inwardly directed peripheral wall 91 (FIGS. 2, 4 and 6 ) of an outwardly directed rib 92 of the heavy duty access cover 46 .
The compression clamp and seal assembly 100 is best illustrated in FIG. 9 of the drawings, and includes an O-ring type annular seal 105 and a compression clamp 115 . The annular seal 105 includes an outer cylindrical leg portion 106 , a bight portion 107 , and an inner cylindrical leg portion 108 collectively defining therebetween a slot or groove 109 which receives the wall portion 39 of the lower tubular section 24 . A generally radially inwardly directed wall portion 101 of the annular seal 105 is sandwiched between opposing generally radial wall portions 102 , 103 of the intermediate tubular section 23 and the lower tubular section 24 , respectively. A number of conventional annular sealing lips (unnumbered) are carried by the wall portions 108 , 101 .
The compression clamp or clamping means 115 of the compression clamp and seal assembly 100 is a one-piece molded polymeric/copolymeric band of a substantially U-shaped configuration over a major portion of the length thereof from a first end portion 112 to an opposite second end portion 113 at which a minor portion 114 continues in the form of a tongue or tab having a plurality of equally spaced narrow slots 119 and a tool receiving opening 116 . The end portion 112 of the major portion includes an upstanding wall 117 (FIG. 11) having a slot 118 and adjacent to the latter a depending flexible latching tab 125 carries a projection 121 . The flexible latching tab 125 is bordered by a U-shaped slot 124 . A slot 128 is formed through the flexible locking tab 125 . The first end portion 112 further includes a group of equally spaced slots 121 and an upstanding locking tab 122 having an opening 123 .
After the annular seal 105 has been assembled upon the wall portion 39 in the manner illustrated in FIG. 9, the upper tubular riser section 23 is seated upon the sealing lips (unnumbered) of the radial wall portion 101 of the annular seal 105 after which the compression clamp 115 is positioned in loosely surrounding relationship thereto, as is also illustrated in FIG. 9 of the drawings. The tongue 114 of the compression clamp 115 is inserted through the slot 118 (FIG. 12) and over and beyond the locking tab 122 . A tool, such as a screwdriver, is then inserted through the tool receiving opening 116 or any one of the slots 119 and the end of the blade thereof is seated in a selected one of the slots 121 of the first end portion 112 of the compression clamp 115 after which the screwdriver is levered or fulcrumed in a conventional manner to draw the tongue 114 further through the slot 118 and further over and further beyond the locking tab 122 which progressively constricts the compression clamp 115 against the outer cylindrical leg portion 106 (FIG. 9) of the annular seal 105 eventually creating a water-tight seal therebetween and a water-tight seal between the sealing lips (unnumbered) and the opposing wall portion 39 of the valley 36 . When the compression clamp 115 is tightened manually in this fashion sufficiently to assure a water-tight seal, the tongue 114 is manipulated as need be by utilizing the screwdriver to align one of the slots 119 of the tongue 114 with the locking tab 122 and subsequently uniting the two together in the manner illustrated in FIG. 12 at which point the locking tab or projection 122 projects through one of the slots 119 , as is illustrated in FIG. 12 . If desired a lock, bolt, locking ring or a wire can be passed through the opening 123 of the locking tab 122 and thereafter twisted to preclude inadvertent/accidental disassembly of the locking tab 122 from its assembled condition (FIG. 2 ).
The compression clamp 115 performs a number of functions effectively, such as compressing the annular gasket 105 to effect a water-tight seal between any two components, preventing vertical separation between components, maintaining horizontal alignment of the components, and creating in effect two seals, one afforded by the inner cylindrical leg portion 108 and the other by the radially inwardly directed wall portion 101 of the annular seal or gasket 105 . The latter assures a water-tight seal between all tubular sections and between the uppermost tubular section or riser 22 , the associated safety/service cover 45 thereof, and the heavy duty access cover 46 . The latter two covers 45 , 46 are also preferably tether-connected to the upper tubular section or riser 23 by respective retainer cables 145 , 146 , respectively (FIG. 2 ).
The compression clamp 115 is released and removed by first releasing and removing the locking ring or twisted wire passing through the opening 123 . Thereafter the end of the tongue 114 adjacent the slot 116 can be manually gripped or gripped by a pair of pliers and pulled upwardly to remove locking tab 122 from its associated slot 119 . At this time the flexible latching tab 125 is still engaged in its associated slot 119 (FIG. 12) and further lifting of the tongue 114 upwardly will have no effect thereon. A blade of the screw driver is inserted through the slot 128 with its end engaged against the underlying upper surface (unnumbered) of the first end portion 112 , and thereafter the blade is pivoted or torqued to the right, as viewed in FIG. 12, causing the flexible latching tab 125 to flex to the phantom outline position of FIG. 12 which draws the depending latching projection 121 outwardly of its associated slot 119 thereby completely releasing the compression clamp 115 .
Installation
Reference is made to FIG. 1 of the drawings, and it is assumed for the moment that the wastewater treatment unit 20 has not been installed and that a single pipe or sewer pipe extends from the wastewater treatment plant 11 to the soil absorption system 14 which has become “plugged” through the retention of solids, as described earlier herein, thereby potentially causing a back-up of sewage into an associate home (not shown). The soil absorption system 14 is considered “failed” and “rejuvenation” of a “failed” soil absorption system 14 is not technically feasible, except at the considerable inconvenience, danger and expense earlier noted. However, in keeping with the present invention, the site at which the waste treatment unit 20 , and particularly the solids settling and retention basin 21 , is to be installed is first excavated by simply digging a hole to expose the existing sewer line or pipe (not shown). A relatively narrow sewer trench is dug along the length of the original sewer line to enable its entire removal. A hole must also be dug or excavated for the solids settling and retention basin 21 . Since the maximum outside diameter of the solids settling and retention basin 21 is approximately 24″, the excavation should be at a minimum of 36″×36″ square or approximately 36″ diameter, if round. The exact excavation depth depends upon a variety of factors and of importance is the vertical distance between grade or grade level GL and the outlet (unnumbered) of the clarifier 17 from which the old sewer line is removed and replaced by the outlet pipe 15 . The closer the outlet pipe 15 to grade level GL, the less the depth of the excavation and vice versa. One or more risers of required heights might necessarily have to be added above the middle tubular section 21 , while one or more rings of required heights might necessarily have to be added below the middle tubular section 21 depending upon the specifics of the installation. As a typical example, the excavation for the solids settling and retention basin 21 is preferably deep enough to permit a minimum 4″ levelling bed or pad P of gravel, sand or fine crushed stone upon which rests the bottom wall 25 of the solids settling and retention basin 21 . In actual practice and in the present example the distance D 1 between the upper edge (unnumbered) of the upper tubular section or riser 22 (FIGS. 1 and 2) and the bottom wall 25 is approximately 70¼″ and the distance D 2 from the top of the heavy duty access cover 46 and grade level GL is approximately 7½″. Thus the total depth of the excavation would be approximately 75″ to 80″ depending upon the total thickness or depth of the leveling pad P.
The new outlet pipe (influent sewer line) 15 is then connected to the clarifier opening (unnumbered) of the wastewater treatment plant 11 , though not permanently connected thereto. The outlet pipe (effluent sewer line) 16 can be positioned in the sewer trench, generally as illustrated in FIG. 1, though not necessarily permanently connected to the soil absorption system 14 . The distance between the top surface of the leveling pad P and the center of the pipe 15 is measured to assure that the inlet coupling 18 , previously bolted to the flat wall portion 98 of the tubular section 23 , will be in axial alignment with the pipe 15 . Obviously, the axis of the pipe 15 must be preferably 1″ minimum above the axis of the pipe 16 upon the complete installation of the wastewater treatment unit to assure that the pipes 15 , 16 are aligned with and enter into the couplings 18 , 19 which are of the same 1″ fall because of the 1″ difference in the axes Ao and Ao′ earlier described. In the specific example given the lower tubular section 24 of the solids settling and retention basin 21 is selected and, for example, formed by selectively removing scrap material from several of the molded basin bodies 30 such that when clamped to the middle tubular section 21 and installed with the bottom wall 25 resting upon the levelling pad P, the total distance D 3 from the bottom wall 25 to the volute (bottom) of the pipe 15 is approximately 38⅛ and the distance D 4 of the volute (bottom) of the pipe 16 from the bottom wall 25 of the solids settling and retention basin 21 is 37⅛″ which is a natural 1″ fall between the two.
The solids settling and retention basin 21 is then lowered into the excavation with its bottom wall 25 seated upon the upper surface of the levelling pad P after which the pipe 15 can be inserted into and solvent-welded to the coupling 18 . An appropriate conventional seal is provided between the outlet pipe 15 and the wall (unnumbered) of the wastewater treatment plant 11 . The pipe 16 is likewise inserted into and solvent-welded to the coupling 19 and to the soil absorption system 14 . Prior to making the latter permanent connections, a level is applied to the solids settling and retention basin 21 to assure horizontal level and vertical plum thereof.
The solids settling and retention basin 21 should be back-filled immediately after the pipes 15 , 16 have been permanently installed. The sewer trench above the pipes 15 , 16 should also be back-filled. However, before back-filling the heavy duty access cover 46 should be at least seated upon, though not necessarily locked to the riser 22 to prevent dirt or debris from entering the solids settling and retention basin 21 during back-filling. The finished grade GL should be 3″ below the upper edge (unnumbered) of the solids settling and retention basin 21 .
Immediately after back-filling, the access cover 46 is removed and the solids settling and retention basin 21 is filled with hold down water, although the hold down water can be added before back-filling.
The filtering body 70 of the wastewater treatment mechanism 50 , excluding the housing 90 , the upper closure assembly 120 , the baffle plate assembly 110 carried by the upper closure assembly 120 , the chlorination feed tube 141 , the dechlorination feed tube 181 , the moisture/vapor shield or cover 55 and the safety/service cover 45 , is lowered into the solids settling and retention basin 21 . Natural buoyancy created by the hold down water will cause the filtering body 70 to tend to float in the hold down water, but a hose can be utilized to direct water into the filtering body 70 through the open upper end thereof resulting in the gradual sinking of the filtering body 70 into the solids settling and retention basin 21 . During the latter assembly the filtering body 70 is aligned such that the flange coupler 451 (FIG. 2) progressively vertically enters into and seats in the U-shaped receiving flange or coupling 456 (FIG. 2 ). In the final installed position of the filtering body 70 the flange 75 thereof rests upon the rib 95 of the solids settling and retention basin 21 . Means (not shown) may be utilized to secure the flange 75 upon the rib 95 , as, for example, four circular discs equally spaced about the periphery of the flange 75 and vertically pivotally mounted thereto in an eccentric fashion such that each disc can be rotated in a horizontal plane about a vertical axis from a position entirely inside the periphery of the flange 75 to a radially outwardly projecting position with a portion of each disc being received within the opposing valley and underlying the uppermost rib of the solids settling and retention basin 21 thereby preventing vertical withdrawal of the filtering body 70 therefrom.
Thereafter the unitized housing 90 , the upper closure assembly 120 , and the baffle plate assembly 110 suspendingly supported from the latter are inserted progressively into the filtering body 70 until the outlet port 176 is aligned with the tubular discharge pipe 453 of the first flange coupler 451 after which the housing 90 is shifted to the right to the position illustrated in FIG. 2 .
The moisture/vapor shield or cover 55 is positioned atop the flange 75 and is conventionally secured thereto by passing fasteners through openings (not shown) in the circular disc 51 of the safety/service guard or cover and threading the same into the flange 75 of the filtering body 70 . The chlorination tube 141 and the dechlorination tube 181 are telescopically assembled through the tubular portions 57 , 58 , respectively, to the position illustrated in FIG. 2 . Chlorination tablets are inserted in the chlorination tube 141 and dechlorination tablets are inserted into the dechlorination tube 181 before or after the latter installation with caps (unnumbered) being appropriately assembled thereon. The safety/service guard or cover 45 and the heavy duty access cover 46 are then assembled, as shown in FIG. 2, and locked by means of the associated compression clamp and seal assembly 100 .
Operation
Under normal conditions, wastewater W (FIG. 1) within the clarification chamber or clarifier 17 of the wastewater treatment plant 11 is at a wastewater level L dependent upon the hydraulic head, and the rate of flow of the wastewater/effluent through the wastewater treatment unit 20 and particularly the wastewater treatment mechanism 50 thereof will depend upon the head or height of the wastewater within the clarification chamber 17 . During such normal hydraulic head, the level L of the wastewater approximates the position of the lowermost of the diametrically opposite pair of flow equalization ports or openings 81 , and this is the design flow level DFL of the wastewater treatment unit 20 , as established by the flow equalization ports 81 of the wastewater treatment mechanism 50 . Under such normal design flow conditions, wastewater not only accumulates in the solids settling and retention basin 21 , but small solids or particles Ss (FIG. 2) pass through the smaller mesh of the lower cylindrical filtering wall portion 72 while larger solid particles Sp falling downwardly and accumulating upon and above the bottom wall 25 of the solids settling and retention basin 21 . The wastewater and still smaller particles Sss which have passed through the filtering wall portion 72 but are too light to settle upon the bottom wall 71 of the filtering body 70 flow upwardly and through the baffle plate assembly 110 during which the smallest particles are filtered out from the wastewater by the baffle plates 99 . The wastewater eventually discharges through an opening (not shown) in the upper closure assembly 120 and passes through the outlet ports 176 , 453 into the pipe 16 with prior chlorination and dechlorination being effected, if desired, in the manner disclosed in U.S. Pat. No. 5,264,120. In the case of a retro fit for a failing or failed disposal system, the essentially solids-free wastewater/effluent continues toward its discharge at the soil absorption device 14 which though plugged can absorb and disperse the substantially solids-free effluent thereby rejuvenating the entire wastewater treatment system 10 due to the extraction of the solids or solid particles Sp, Ss, Sss and Spl within the solids settling and retention basin 21 , the bottom wall 71 and within and upon the approximately three dozen baffle plates 99 of the baffle plate assembly 110 . Should the installation be for a new wastewater treatment system, the substantial solids-free effluent extends the life of the disposal system substantially indefinitely.
Should the flow of wastewater from the clarification chamber 17 exceed the design flow designated by the design flow level DFL (FIG. 2 ), as controlled by the diametrically opposite flow equalization ports 81 , the wastewater will rise to a higher sustained flow level SFL at which the pair of flow equalization ports 82 become operative, as described in U.S. Pat. No. 5,264,120.
During peak flow of wastewater from the clarification chamber 17 , the wastewater reaches a peak flow level PFL established by the larger diameter flow equalization ports 83 , just as in the case of U.S. Pat. No. 5,264,120 with, of course, solids or solid particles Spl passing through the larger mesh of the upper cylindrical filtering wall portion 73 and settling down and upon the bottom wall 71 of the filtering body or filtration media body 70 .
Servicing and Cleaning
Access to the interior of the wastewater treatment unit 20 is required from time-to-time during normal use and is readily effected by removing the compression clamp 115 associated with the access cover 46 . Upon unlatching and removing the compression clamp 115 , the access cover 46 and the safety/service cover 45 can be removed. The chlorination and dechlorination tubes 141 , 181 can simply be filled with tablets or can be removed by pulling the same vertically upwardly. Each tube 141 , 181 can be flushed and cleaned, refilled with chlorination and dechlorination tablets, and reassembled to the position illustrated in FIG. 2 after which the components 45 , 46 and 115 can be reassembled. Obviously the feed tubes 141 , 181 need not be removed when the only servicing required is to add respective chlorination and dechlorination tablets thereto.
Over longer periods of time the entire wastewater treatment unit 20 must be completely cleaned to remove all of the solids accumulated in the solids settling and retention basin 21 , all of the solids accumulated upon the bottom wall 71 of the filtering body 70 and all of the solids accumulated upon each of the baffle plates 99 of the baffle plate assembly 110 . Such servicing is again accomplished by first removing the uppermost compression clamp 115 , the access cover 46 and the safety/service cover 45 . The feed tubes 141 , 181 are then withdrawn upwardly and removed followed by the removal of the moisture/vapor shield or cover 55 after unfastening the cover disc 51 from the flange 75 of the filter media body 70 .
The entire housing 90 of the wastewater treatment mechanism 50 can now be lifted upwardly by, for example, manually grasping the closure assembly 120 or utilizing a special tool (not shown) which interlocks with the upper closure assembly 120 . Since the baffle plate assembly 110 is secured to the upper closure assembly 120 , the unitized components 90 , 110 , 120 are removed in unison. The unitized components 90 , 110 , 120 must, of course, be lifted straight up, as viewed in FIG. 2, to remove the outlet port 176 from the discharge pipe 453 prior to lifting and removing components upwardly and outwardly from the filter media body 70 .
The flange 75 of the filter media body 70 is then detached from the solids settling and retention basin 21 by rotating the eccentrically mounted, vertically pivoted, four circular discs in a horizontal plane (not shown and earlier described) to remove the same from the opposing valley which is the uppermost unnumbered valley of the middle tubular section 23 of the solids settling and retention basin 21 . The solids settling and retention basin 21 can then be lifted vertically upwardly to detach the couplings 451 , 456 . A suction hose/line can be inserted into the filtering body 70 to withdraw wastewater and solids therefrom prior to lifting the filtering body 70 upwardly and outwardly of the solids settling and retention basin 21 to ease the effort involved in this task. The same suction line can then be inserted into the solids settling and retention basin 21 to draw wastewater and the solids accumulated therein while simultaneously washing and cleaning the interior of the solids settling and retention basin 21 utilizing water from a garden hose until the solids settling and retention basin 21 is thoroughly cleansed and rinsed. Thereafter, the safety/service cover 45 can be temporarily seated in the upper end of the riser 22 to preclude dirt or debris from entering the now cleaned solids settling and retention basin 21 while cleansing the withdrawn remaining components in the immediately environs. Water from a garden hose is directed to all surfaces of all of these components including the individual baffle plates 99 upon disassembly thereof from the baffle plate assembly 110 in the manner disclosed in U.S. Pat. 5,264,120.
After all components have been thoroughly cleaned, they are reassembled in a manner apparent from the description of the disassembly thereof, with, of course, chlorination and dechlorination tablets being added to the respective feed tubes 141 , 181 before or after the reassembly thereof. The moisture/vapor cover 55 , the safety/service closure 45 , the access cover 46 and the compression clamp 115 are reassembled in the manner shown in FIG. 2, and the wastewater treatment unit 20 is ready for continued long term wastewater treatment/disposal.
It is to be particularly understood that though the solids settling and retention basin 21 of FIGS. 1 and 2 is sectional, the same can and for the most part will remain as a one-piece molded body as aforesaid with the openings O, O″ being cut therein at the factory to make certain that the axis Ao is 1″ higher than the axis Ao′ of the opening O′ thereby assuring the necessary natural 1″ fall to achieve efficient flow-through from the pipe 15 to the pipe 16 . Also, with the connectors 18 , 19 being bolted to the wall portions 98 at the factory, when the one-piece solids and retention basin 21 is delivered to the site for installation, the only major criteria required for proper flow-through is to make certain that the discharge pipe 15 has an acceptable fall from the wastewater treatment plant 11 to the opening O and additional fall from the opening O′ to the soil absorption system 14 .
Also though the invention has been described specifically with respect to the installation of the wastewater treatment unit 20 relative to an existing wastewater treatment plant 11 and a plugged soil absorption system 14 , the wastewater treatment plant 11 is equally applicable to “new” installations. In the case of a new installation, an area of the ground must be excavated to also include the new wastewater treatment plant 11 and, of course, a new soil absorption system 14 is installed. Obviously, there are no pre-existing sewer pipes to remove and, therefore, the installation remains essentially identical for the new system as that earlier described for the “old” or “plugged” system.
Although a preferred embodiment of the invention has been specifically illustrated and described herein, it is to be understood that minor variations may be made in the apparatus without departing from the spirit and scope of the invention, as defined the appended claims. | A method of and an apparatus for rejuvenating a wastewater treatment system of the type including a septic tank, an aerobic treatment unit or the like connected by a pipe to a plugged downstream soil absorption system includes a wastewater treatment unit which is interposed between the septic unit/aerobic treatment unit and the downstream soil absorption system. The wastewater treatment unit includes a single piece or a multiple piece solids settling and retention basin within which is suspendingly supported a wastewater treatment mechanism essentially of the type disclosed in U.S. Pat. No. 5,264,120. The wastewater treatment mechanism includes filters for filtering and settling solids from wastewater and flow equalization ports for effecting flow equalization thereby eliminating flow surges to the downstream plugged soil absorption system. By utilizing an extremely compact solids settling and retention basin and its attendant operative components, solids are prevented from passing beyond the wastewater treatment unit to the failed soil absorption system. In this fashion the wastewater treatment unit of the present invention can rejuvenate wastewater treatment systems which have failed, and if installed prior to such failure, can extend the life thereof substantially indefinitely. The latter and other advantages are achieved at relatively low cost, absent destruction of existing sod or lawn, moving fencing, trees, etc., and absent creating a hazard for individuals, particularly small children. | 8 |
RELATED APPLICATIONS
The present invention is a continuation-in-part of, was first described in, and claims the benefit of U.S. Provisional Application No. 62/138,419, filed Mar. 26, 2015, the entire disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to a stabilizer pad having interiors to removably secure objects having matching appendages.
BACKGROUND OF THE INVENTION
There are a great many products used around homes and businesses in an outdoor environment. These objects include everything from tables and chairs, ladders, planters, portable awnings, to heavier objects such as support jacks used for recreational vehicles and the like. Unfortunately, when such objects are placed on soft ground surfaces such as grass or even asphalt, they are not level and/or sink into the ground immediately or over time. Many resort to the use of blocks of wood to help level, stabilize, and to prevent sinking. It is quickly realized that these blocks of wood are often too thick, too thin, or not wide enough. This causes the blocks to slip, slide, and create even more problems than they were intended to solve. Accordingly, there exists a need for a means by which various types of door objects can be supported, leveled, and stabilized in order to prevent problems as described. The development of the stabilizer pad fulfills this need.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a stabilizing pad system, including at least one (1) first generally square resilient body, each having a planar first side, a planar second side, and a first recessed area located within a first interior rib upstanding from the first side. The system also includes least one (1) second square resilient body, each having a planar third side, a planar fourth side, a first perimeter rib disposed about a perimeter of the third side, a second recessed area located between a second interior rib upstanding from the third side and the first perimeter rib, a second perimeter rib disposed about a perimeter of the fourth side, and a third recessed area located between a third interior rib upstanding from the fourth side and the second perimeter rib. The first interior rib is capable of stacking with either the second or third interior rib. The first recessed area is capable of receiving and supporting a portion of a piece of weighted object therein. Some embodiments also include a fourth recessed area located within a fourth interior rib upstanding from the second side. wherein said plurality of notches are capable of removably receiving said fourth interior rib therein of another first body. The fourth interior rib is capable of stacking with either the second or third interior rib. The fourth recessed area is also capable of receiving and supporting a portion of a piece of weighted object therein.
Another object of the present invention is to provide for the first interior rib or fourth rib of the first body to be generally circular.
Another object of the present invention is to provide for the first interior rib to be generally rectangular. In certain embodiment, the first interior rib further has a plurality of notches. Such plurality of notches is shaped to be capable of removably retaining the circular shape of the first or fourth interior rib. Some embodiments include a second plurality of notches shaped to be capable of removably retaining the rectangular shape of the first interior rib.
Another object of the second body it to have the second interior rib to include a first center portion located on a center of the third side, and a first plurality of linear portions, each radiating outward from the first center portion to the first perimeter rib. Similarly, the third interior rib further includes a second center portion located on a center of the fourth side, and a second plurality of linear portions, each radiating outward from the second center portion to the second perimeter rib. In certain embodiments, the first plurality of linear portions includes a plurality of notches, each capable of removably receiving either the first or fourth interior rib from the first body. The first plurality of linear portions can also include another plurality of notches, each capable of removably receiving either first or fourth interior rib from the first body. Similarly, the second plurality of linear portions can include a plurality of notches, each capable of removably receiving either first or fourth interior rib from said first body. The second plurality of linear portions can also include another plurality of notches, each capable of removably receiving either first or fourth interior rib from the first body.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which:
FIG. 1 is a front perspective view of a first embodiment 10 of a stabilizer pad, according to a preferred embodiment of the present invention;
FIG. 2 is a front perspective view of a second embodiment 20 of a stabilizer pad, according to an alternate embodiment of the present invention;
FIG. 3 is a front perspective view of a third embodiment 30 of a stabilizer pad, according to an alternate embodiment of the present invention;
FIG. 4 is a front perspective view of a fourth embodiment 40 of a stabilizer pad, according to an alternate embodiment of the present invention;
FIG. 5 is a rear perspective view of a first embodiment 10 of a stabilizer pad, according to a preferred embodiment of the present invention;
FIG. 6 is a rear perspective view of a second embodiment 20 of a stabilizer pad, according to an alternate embodiment of the present invention;
FIG. 7 is a rear perspective view of a third embodiment 30 of a stabilizer pad, according to an alternate embodiment of the present invention; and,
FIG. 8 is a rear perspective view of a fourth embodiment 40 of a stabilizer pad, according to an alternate embodiment of the present invention.
DESCRIPTIVE KEY
10 first embodiment
11 first embodiment first recessed area
12 first embodiment first side interior rib
13 first embodiment arcuate notch
14 first embodiment center notch
15 first embodiment first side
16 first embodiment second recessed area
17 first embodiment second side
18 first embodiment second side interior rib
20 second embodiment
21 second embodiment recessed area
22 second embodiment interior rib
23 second embodiment arcuate notch
24 second embodiment center notch
25 second embodiment first side
27 second embodiment second side
30 third embodiment
31 third embodiment first recessed area
32 a third embodiment first side interior rib
32 b third embodiment second side interior rib
33 a third embodiment first side first notch
33 b third embodiment first side second notch
34 third embodiment first side perimeter rib
35 third embodiment first side
36 third embodiment second recessed area
37 third embodiment second side
38 a third embodiment second side first notch
38 b third embodiment second side second notch
39 third embodiment second side perimeter rib
40 fourth embodiment
41 fourth embodiment recessed area
42 fourth embodiment interior rib
45 fourth embodiment first side
47 fourth embodiment second side
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within FIGS. 1 through 3 . However, the invention is not limited to the described embodiment and a person skilled in the art will appreciate that many other embodiments of the invention are possible without deviating from the basic concept of the invention, and that any such work around will also fall under scope of this invention. It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one (1) particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope.
The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one (1) of the referenced items.
The stabilizer pad, as its name implies, is a set of interlocking pads available in multiple embodiments 10 , 20 , 30 , 40 used to support, level, and spread the weight impact of concentrated loads in an outdoor environment. The first embodiment 10 , second embodiment 10 , and fourth embodiment 40 are each capable of being placed under and protecting legs of an object, the third embodiment 30 is capable of enabling stacking of adjacent ones of either the first embodiment 10 , second embodiment 20 , or fourth embodiment 40 .
Referring now to FIGS. 1, 2, 4-6, and 8 , each of the first embodiment 10 , second embodiment 20 , and fourth embodiment 40 is capable of being placed under various objects or legs of objects. The pads 10 , 20 , 40 may vary in size according to need; however an average size pad is envisioned to be a generally square shape with rounded corners and sized approximately twelve square inches (12 in 2 ). Each pad 10 , 20 , 40 would vary in thickness from one-quarter inch (¼ in.) up to one inch (1 in.) or more. The first side 15 , 25 , 45 , of the first embodiment 10 , second embodiment 20 , and fourth embodiment 40 is provided either with a circular or rectangular center recessed area 11 , 21 , 41 to hold the original object or leg of the object. The recessed area 11 , 21 , 41 is provided with additional interlocking segments such as interior support ribs 12 , 22 , 42 that complement the perimeter of the object it is supporting. These support ribs 12 , 22 , 42 can be provided with inner locking anti-rotation tabs. Each pad 10 , 20 , 40 would be used on objects such as chairs, tables, ladders, portable awnings, trailer jacks, and the like. The user can adjust the height of the object or level individual parameters of the object by placing at least one (1) pad 10 , 20 , 40 under the object. It is possible to also include the third embodiment 30 in order to stack multiple embodiments 10 , 20 , 30 , 40 together to achieve the desired height. While originally viewed as a method to obtain a desired height or level an object, it may also be used to protect products from ground contact and to prevent any point of load objects from sinking into the ground.
Referring now to FIGS. 4 and 5 the fourth embodiment first side 45 and the first embodiment second side 17 each has a recessed area 41 , 16 in the shape of a circle. Both the fourth embodiment first side 41 and the first embodiment second side 17 has respective fourth embodiment interior rib 42 a first embodiment second interior rib 18 also in the general shape of a circle. The fourth embodiment interior rib 42 and first embodiment second interior rib 18 are continuous.
Referring now to FIGS. 1 and 2 , the first embodiment first side 15 and second embodiment first side 25 each have interior support ribs 12 , 22 that are discontinuously in the form of a rectangle. The sides with the shorter length are continuous. The sides with the greater length has aligned center notches 14 , 24 . Adjacent the ends of the side with the greater length are arcuate notches 13 , 23 corresponding to the circular shape of the fourth embodiment interior rib 42 and first embodiment second interior rib 18 . As such, this enables the fourth embodiment first side 45 to have a friction fit nesting stacking arrangement with either the first embodiment first side 15 or second embodiment first side 25 . Similarly, the first embodiment second side 17 also can enjoy a friction fit nesting stacking arrangement with either another first embodiment first side 15 or a second embodiment first side 25 .
Referring now to FIGS. 6 and 8 , the second embodiment second side 27 and the fourth embodiment second 47 are each planar and have no ribs.
Referring now to FIGS. 3 and 7 , the third embodiment 30 has a general shape similar to that of the first embodiment 10 , second embodiment 20 , and fourth embodiment 40 , although it is thicker. The third embodiment has a first side 35 and second side 37 having identical features. The third embodiment 30 is capable of employing friction fit nesting stacking arrangements of either the first embodiment 10 , second embodiment 20 , or fourth embodiment 40 on either the third embodiment first side 35 or third embodiment second side 37 . The third embodiment first side perimeter rib 34 is continuously disposed about the perimeter of the third embodiment first side 35 . Similarly, the third embodiment second side perimeter rib 39 is continuously disposed about the perimeter of the third embodiment second side 37 . The third embodiment first interior rib 32 a is fashioned as a continuous small circular portion centered on the third embodiment first side 35 and a plurality of discontinuous radiating ribs connecting to the third embodiment first side perimeter rib 34 . Similarly, the third embodiment second interior rib 32 b is fashioned as a continuous small circular portion centered on the third embodiment second side 37 and a plurality of discontinuous radiating ribs connecting to the third embodiment second side perimeter rib 39 . In a preferred embodiment, the number of radiating ribs are eight (8) and they are equidistantly spaced from each other. The third embodiment first recessed area 31 corresponds to all the area between the third embodiment first side perimeter rib 34 and third embodiment first side interior ribs 32 a , whereas the third embodiment second recessed area 36 corresponds to all the area between the third embodiment second side perimeter rib 39 and third embodiment second side interior ribs 32 b.
Similar to the first embodiment and second embodiment interior ribs 12 , 42 , the third embodiment 30 has a plurality of notches 33 a , 33 b , 38 a , 38 b to enable the friction fit nesting stacking arrangement between either side 35 , 37 of the third embodiment 30 with the circular shape of the interior rib 42 , 18 of the first embodiment second side 17 or fourth embodiment first side 45 , or the rectangular shape of the interior rib 12 , 22 of the first embodiment first side 15 or second embodiment first side 25 . The plurality of radiating ribs on the third embodiment first side 35 has a plurality of third embodiment first side first notches 33 a aligned in an arrangement capable of receiving in a friction fit nesting stacking arrangement of the rectangular shape of the first embodiment first side interior rib 12 and second embodiment interior rib 22 . Similarly, the plurality of radiating ribs on the third embodiment second side 37 has a plurality of third embodiment second side first notches 38 a aligned in an arrangement capable of receiving in a friction fit nesting stacking arrangement of the rectangular shape of the first embodiment first side interior rib 12 and second embodiment interior rib 22 . The plurality of radiating ribs on the third embodiment first side 35 has a plurality of third embodiment first side second notches 33 b aligned in an arrangement capable of receiving in a friction fit nesting stacking arrangement of the circular shape of the first embodiment second side interior rib 12 and fourth embodiment interior rib 42 . Similarly, the plurality of radiating ribs on the third embodiment second side 37 has a plurality of third embodiment first side second notches 38 b aligned in an arrangement capable of receiving in a friction fit nesting stacking arrangement of the circular shape of the first embodiment second side interior rib 12 and fourth embodiment interior rib 42 .
The use of each pad 10 , 20 , 30 , 40 provides a means to stabilize and level outdoor objects in a manner which is quick, easy, and effective. The materials required to produce each stabilizer pad 10 , 20 , 30 , 40 are all readily available and well known to manufacturers of goods of this type. Each of the pads 10 , 20 , 30 , 40 would be made of high density, ultraviolet (UV) resistant plastic in an injection molding process. Such a process would require the design and use of custom molds. The raw materials as used in each pad 10 , 20 , 30 , 40 would best be obtained from wholesalers and manufacturers that deal in goods of that nature and assembled at a final location. The relatively simple design of each pad 10 , 20 , 30 , 40 and the material of construction make it a cost-effective design due to the relatively low material and labor costs involved. Final production of each pad 10 , 20 , 30 , 40 will be performed by manufacturing workers of average skill.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention and method of use to the precise forms disclosed. Obviously many modifications and variations are possible in light of the above teaching. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application, and to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions or substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but is intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention. | A stabilizer pad includes a generally square shape with an interior area having a geometry adapted to removably secure objects having either matching geometrical bases. The pad is capable of stacking upon an identically shaped pad. | 1 |
This application is a continuation of application Ser. No. 729,848 filed May 3, 1985, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to an electrodialytic process for recovering mixed acids from mixed salts. More particularly, the invention is directed to the recovery of mixed acids comprising HF and, for example, HNO 3 from spent process materials such as pickling liquors by a process which employs a three-compartment electrodialytic water splitter.
Pickling baths, for example, are employed to remove scale, oxides, and other impurities from metal surfaces such as stainless steel. These baths comprise inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, and hydrofluoric acid, and commonly are mixtures thereof. Eventually, the acids in these baths are exhausted due to the reactions of the acids with the oxides, scale, etc. Consequently, the pickling acids are converted to a spent solution comprising acidified mixed salts. This spent solution must then be disposed of and the acids lost must be replaced. The acids, particularly hydrofluoric and nitric, are costly to replace. Moreover, the toxicity of the spent materials, especially hydrofluoric acid, can create significant environmental damage if improperly disposed of, and the large volumes of the exhausted baths add a very substantial cost to pickling processes due to the cost of disposing of these materials.
Processes for regenerating processing materials are known. For example, U.S. Pat. Nos. 3,477,815 and 3,485,581 disclose processes for removing SO 2 from combustion gases employing a scrubbing solution which can be thermally regenerated, and U.S. Pat. No. 3,475,112 discloses a process for removing SO 2 from combustion gases using a scrubbing solution which can be electrolytically regenerated. Recently, electrodialytic methods have been disclosed for regenerating process solutions. In U.S. Pat. Nos. 4,082,835 and 4,107,015, processes are disclosed for regenerating scrubbing solutions used in stripping SO x from flue gases by feeding the spent solutions through an electrodialytic water splitter.
While concentrated acids can be produced by electrodialytic water splitting methods, such production is limited by the current efficiency of producing these acids. For example, the current efficiency of producing 5% HNO 3 is only about 0.6. Therefore, many processes employing electrodialysis produce relatively dilute acid solutions to insure high current efficiency. For example, in U.S. Pat. No. 4,504,373, a process is disclosed for regenerating a dilute sulfuric acid solution for use in the processing of rayon.
BRIEF DESCRIPTION OF THE INVENTION
We have unexpectedly discovered a process for recovering concentrated mixed acids comprising HF from mixed salts at a high current efficiency. The process comprises the steps of:
(a) providing an electrodialytic water splitter comprising at least one unit cell, each unit cell comprising a first compartment and a second compartment;
(b) feeding an aqueous solution comprising at least two salts formed from at least two different anions to the first compartment, one of said anions being fluoride;
(c) feeding a liquid comprising water to the second compartment;
(d) passing current through said electrodialytic water splitter to produce an aqueous product comprising mixed acids formed from the different anions in the second compartment, and an aqueous salt-containing product comprising a reduced concentration of said anions in the first compartment; and
(e) recovering aqueous products from the second compartment.
Our process is particularly useful in the production of concentrated HNO 3 at unexpectedly high current efficiencies, and has particular utility in the area of regenerating stainless steel pickling acid mixtures comprising HF and HNO 3 .
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically illustrates a three-compartment electrodialytic water splitter employed for carrying out the process of the present invention.
FIG. 2 schematically illustrates a preferred embodiment of applicants' process employing a three-compartment electrodialytic water splitter of the type illustrated in FIG. 1.
FIG. 3 graphically illustrates the decrease in efficiency of electrodialytic water splitting processes as one attempts to produce increasing concentration of a strong acid.
FIG. 4 graphically illustrates the efficiency of the reaction in the salt compartment of a three-compartment electrodialytic water splitter when operated in accordance with the process of the present invention.
FIG. 5 graphically illustrates the substantially increased efficiency for producing a 5% concentration of HNO 3 when operating a three-compartment electrodialytic water splitter in accordance with the process of the present invention.
DETAILED DESCRIPTION
The preferred apparatus employed in performing the basic process of the present invention is known in the art as a three-compartment electrodialytic water splitter. A three-compartment electrodialytic water splitter comprises at least one unit cell, each unit cell comprising cation, water-splitting, and anion membranes arranged in alternating fashion to define base, acid, and salt compartments. A typical unit cell is schematically illustrated as unit cell 13 in FIG. 1.
Employed in each unit cell are means for splitting water into hydrogen ions and hydroxyl ions (water-splitting membrane). Most preferably, the means for splitting water into hydrogen and hydroxyl ions is a bipolar membrane. Examples of bipolar membranes which are particularly useful include those described in U.S. Pat. No. 2,829,095 to Oda et al. (which has reference to water splitting generally), in U.S. Pat. No. 4,024,043 (which describes a single film bipolar membrane), and in U.S. Pat. No. 4,116,889 (which describes a cast bipolar membrane). However, any means capable of splitting water into hydrogen and hydroxyl ions may be used; for example, spaced apart anion and cation membranes having water disposed therebetween.
The cation membranes employed in the electrodialytic water splitter may be moderately acidic (e.g., phosphonic group-containing) or strongly acidic (e.g., sulfonic group-containing) cation permselective membranes having a low resistance at the pH at which they are employed. Particularly useful cation membranes are Dupont's Nafion® acidic fluorocarbon membranes, especially Nafion® 110, 901, and 324 cation membranes.
The anion membranes used in the electrodialytic water splitter are strongly, mildly, or weakly basic anion permselective membranes. Usable membranes are, for example, commercially available from Ionics, Inc., Watertown, Mass. (sold as Ionics 204-UZL-386 anion membrane), or from Asahi Glass Co. (sold under the trade name Selemion® AMV or ASV anion permselective membranes).
FIG. 1 schematically illustrates a typical design of a three-compartment water splitter 10 comprising two unit cells. As shown, the water splitter comprises, in series, an anode (e.g., a platinum anode), an anolyte compartment, alternating base B, acid A, and salt S compartments, a catholyte compartment, and a cathode 12 (e.g., a platinum cathode). The unit cells 13 and 13' are defined by serially arranged membranes as follows: bipolar membrane 13b, anion permselective membrane 13c, and cation permselective membrane 13a', and bipolar membrane 13b', anion permselective membrane 13c', and cation permselective membrane 13a", respectively.
In accordance with the invention, the anolyte and catholyte compartments would contain a salt, base or acid solution (e.g., KOH in the arrangement illustrated in FIG. 1), the base B and acid A compartments would initially contain a liquid comprising water, and the salts compartment would initially contain a mixed salt solution comprising a fluoride salt MF and a salt MX of a different (second) anion (e.g., KF and KNO 3 ). Splitting of the mixed salts into acid and base commences by applying a direct current through the water splitter 10 from the anode 11 to the cathode 12.
In the acid compartment, hydrogen ions (H + ) are added via the function of the bipolar membrane 13b. Simultaneously, anions (designated F - and X - in the drawings) of the salts are transported across the anion membrane 13c into the acid compartment. The reaction of the hydrogen ions with the anions yields a mixed acid product comprising HF and HX. The use of the designation X - (and from that MX or HX) refers not only to monovalent anions other than F - but also to divalent anions, such as sulfates, and trivalent anions, such as phosphates. Ordinarily, the efficiency of HX acid production in the acid compartment would be limited by the leakage of H + ions back into the salt compartment. Applicants have unexpectedly discovered that, due to the presence of fluoride ions in the salt compartment, the hydrogen ions are believed to preferentially react with the fluoride to produce a bifluroide anion, HF 2 - which, in turn, is transported back across the anion membrane 13c in preference to the fluoride anion, F - , thus returning the lost hydrogen ion to the acid compartment. Consequently, more hydrogen ions are available to react with the anion X - , the result of which is the more efficient production of HX.
Cations in the salt compartment simultaneously pass through the cation membrane 13a to the base B compartment. In the base B compartment, the cations, M + , react with the hydroxyl ions generated by the bipolar membrane 13b to produce a basified solution. Consequently, the solution remaining in the salt compartment is depleted in both salts.
As indicated in FIG. 1, cations migrate through cation membrane 13a from the anolyte compartment and similarly pass from the base compartment through the cation membrane 13a'" to the catholyte compartment. Therefore, the anolyte and catholyte solutions are typically continuously recirculated from the anolyte compartment to the catholyte compartment and back (or the reverse) to maintain a substantially constant concentration of base (salt or acid) in each compartment.
It should be understood that the electrodialytic water splitter can be operated in a batch mode, a continuous mode, or variations thereof. It should also be readily apparent that product solutions or portions thereof (e.g., when using a feed and bleed apportionment operation) be recycled for further concentration. Moreover, it should be apparent that mechanisms for serial feed through the compartments (e.g., B to B') may be employed. These and other modifications, changes and alterations to the design of the water splitter will not affect the scope of the invention and will be obvious to thos or ordinary skill.
The water splitter is ordinarily supplied with a direct current ranging from about 30 amps/ft 2 (≈300 A/m 2 ) to about 200 amps/ft 2 (≈2000 A/m 2 ), preferably from about 80 A/ft 2 (≈800 A/m 2 ) to about 120 A/ft 2 (≈1200 A/m 2 ) amps. The system normally operates at a temperature of between about 10° C. and about 80° C. with a temperature range of between about 30° C. and 55° C. being preferred.
A preferred embodiment of the present invention is schematically illustrated in FIG. 2. Spent process material comprising fluoride anions and anions of another kind, for example spent pickling bath liquor comprising acidified fluoride and nitrate salts, is removed from the manufacturing operation and supplied through line 1 to a precipitation chamber 2. To the precipitation chamber 2, is supplied a basified solution (e.g., KOH, NaOH, NH 4 OH, or mixtures thereof, preferably an alkali metal hydroxide, and most preferably KOH) through line 17 for contact with the spent process material. In the event the spent process material contains heavy metal ions (for example, Ni, Fe, Cr, Mn, etc.), the basified solution will react to form hydroxides thereof which will precipitate out. The resulting product (for example a suspension) is then fed through line 3 to a filtration unit (e.g., a plate and frame filter press). In filtration unit 4, the precipitate is filtered from the resulting product and may be washed with, for example, water supplied from line 5 via line 6, and/or with an aqueous depleted salt solution from line 6. The remaining solid is then withdrawn via line 7.
The aqueous filtrate of soluble mixed salts comprising a fluoride salt is then fed via line 8 to each salt compartment of the three-compartment electrodialytic water splitter 10. A liquid comprising water is fed to the acid compartment via line 9, and a liquid comprising water such as aqueous depleted salt solution supplied via line 14a is fed to the base compartment via line 15.
The operation of a three-compartment electrodialytic water splitter is as described with respect to FIG. 1, with mixed acid product being withdrawn via line 11, depleted salt being withdrawn via line 12, and basified solution being withdrawn via line 16. The mixed acid product from line 11 can be directly recycled to the manufacturing process (e.g., to a pickling bath), stored for subsequent use or sale, or recycled through the electrodialytic water splitter for further concentration or some combination thereof. The depleted salt solution from line 12 can be split into two streams via lines 14a and 14b. A portion of the aqueous depleted salt can be recycled (via line 6) through the filtration unit 4 and back to the salt compartment while another portion can be supplied to the base compartment lines 14a and 15 for basification. In addition, the depleted salt may be used to dilute the process liquor or may be concentrated by, for example, reverse osmosis or electrodialysis to yield a relatively concentrated salt solution (which may be reintroduced into the water splitter) and a relatively pure water stream (which may be used for washing the precipitate or as make-up water in the electrodialysis process). The basified solution (either as a relatively pure base or as a basified salt solution when depleted salt is supplied) is recycled from the electrodialytic water splitter via line 16 and 17 to the precipitation unit 2.
The process of the present invention is capable of operating with an aqueous mixed salt-containing solution having varied concentration. Typically, the concentration of the mixed salts should be at least about 0.4 molal, and preferably is at least about 1 molal. More importantly, however, the concentration of fluoride anion in the mixed salts should be at least about 0.1M, preferably at least about 0.2M, and most preferably at least about 0.4M. Generally, the fluoride concentration is between 0.1M and about 3.0M, preferably between about 0.2M and 2.0M and most preferably between about 0.4M and 1.0M.
The liquid supplied to the acid compartment comprises water and is generally selected from the group consisting of water, aqueous acid solutions or dilute salt solutions. The liquid supplied to the base compartment also comprises water and is generally selected from the group consisting of water, aqueous basic solutions, and depleted salt solutions (e.g., from the salt compartment). Feedstreams to both the acid and base compartments can be supplied either by independent supply systems, through a recycle of all or part of the liquid removed from a particular compartment, or some combination thereof.
Typically, the process is capable of producing HF at a concentration of up to about 15% by weight and the additional acid or acids at a total wt % of up to about 12% at unexpectedly high efficiencies. FIG. 3 graphically illustrates the efficiency for the production of HNO 3 from KNO 3 as a function of HNO 3 concentration in the acid compartment of a three-compartment electrodialytic water splitter. FIGS. 4 and 5 graphically illustrate the unexpectedly improved efficiency for the production of nitric acid from nitrate when fluoride is also present in the salt compartment. The graphs were generated from test data gathered from using an electrodialytic water splitter having unit cells comprising an Asahi ASV anion membranes, cast bipolar membranes of the type disclosed in U.S. Pat. No. 4,116,889, and Dupont Nafion® 324 cation membranes to produce 5% by weight nitric acid. As is clearly indicated from FIG. 3, the efficiency of nitric acid production dropped steadily from about 0.8 at 1% HNO 3 to about 0.6 at 5% HNO 3 , with continuously decreasing efficiency at higher concentrations. In accord with our invention, FIG. 4 illustrates the highly efficient transfer of fluoride and nitrate ions from the salt compartment to the acid compartment and similarly, FIG. 5 illustrates the highly efficient production of mixed acids in the acid compartment, in particular concentrated nitric acid. As is clearly indicated from FIG. 5, the efficiency of producing 5% by weight nitric acid remains at about 0.8, with an efficiency of about 0.7 for a 7% by weight acid solution (as compared to an efficiency of about 0.5 for a 7% nitric acid solution in the absence of fluoride). Moreover, FIGS. 4 and 5 illustrate a principal mechanism of the process of the invention; namely, the preferential transfer of nitrate ions as compared to fluoride ions and the corresponding increased rate of production of nitric acid as compared to the rate of production of hydrofluoric acid.
The following examples illustrate the practice of the present invention. These examples should not be construed in any way as limiting the invention to anything less than that which is expressly disclosed or which would have been obvious to one of ordinary skill in this art therefrom.
EXAMPLE 1
Spent processing liquor having the following chemical composition was subjected to pretreatment steps prior to being subjected to electrodialytic splitting in accordance with applicants' invention:
______________________________________Ion % Concentration______________________________________F.sup.- ≈5.5NO.sub.3 .sup.- ≈12.7Heavy Metals ≈6.7______________________________________
The density of the liquor was about 1.25 g/mL, and the acidity of the liquor was approximately 6.0 meq - OH/mL to pH 7.
Samples of the liquor were initially treated with 2M NH 3 and 2M KOH to determine the effectiveness for precipitating the heavy metals from the liquor and the filtration rates. Four hundred ml of the process liquor was treated with 1200 ml of 2.0M base (KOH or NH 3 ). In each instance, the filtrate was collected and the cake washed with 400 ml H 2 O. The cake was vacuumed dry and the wash collected. Fluoride ions and nitrate ion analysis indicated the following approximate balance:
TABLE 1______________________________________ Volume Wt. F.sup.- Wt. NO.sub.3 .sup.-Solution (mL) (g) (g)______________________________________Sample 1 (NH.sub.3 treated)Pickle liquor 400 26.9 63.4Filtrate 1200 15.6 46.8Wash 470 4.1 10.7Cake (62.7 g) 9.4 5.0Sample 2 (KOH treated)Pickle liquor 400 26.9 63.4Filtrate 1670 25.2 64.1Wash 1670 25.2 64.1Cake (72.8 g) 2.3 2.0______________________________________
The results of these pretreatment steps indicated that KOH was generally more effective in precipitating heavy metal ions.
EXAMPLE 2
For each test reported hereinbelow a three unit cell, three-compartment electrodialytic water splitter was employed. The electrodialytic water splitter was constructed principally with ASV anion membranes, Nafion® 324 cation membranes, and Allied bipolar membranes made in accordance with the procedure disclosed in U.S. Pat. No. 4,116,889. Exposed membrane area for each membrane is about 17 cm 2 . Tests were conducted in batch fashion with solutions being recirculated through the respective compartments of the electrodialytic water splitter. In most cases, estimates of current efficiency were made by measuring concentration and volume changes.
COMPARATIVE TEST 1
The electrodialytic water splitter described was operated under the following conditions:
______________________________________ Current = 1.90 A Δ E = 12.4 (v) min. T = 28-35° C.______________________________________
The salt compartment was initially charged with 1M KNO 3 . Water was initially supplied to the acid base compartments. During the test (7200 second in duration), 431 ml of 1.001M HNO 3 was metered to the base compartment to keep the pH≈7. Concentration of HNO 3 in the acid and salt compartments were determined periodically, as well as the volumes in calibrated reservoirs. Relevant concentrations and volumes are reported in Table 2 below:
TABLE 2______________________________________ACID SALT Volume VolumeTime(s) % HNO.sub.3 (mL) Time(s) % HNO.sub.3 (mL)______________________________________ 150 1.44 295 200 .028 4951750 2.98 300 1800 .168 4823600 4.52 305 3640 .355 4685300 5.71 309 5330 .515 4557100 6.78 314 7120 .638 445______________________________________
The calculated current efficiency and acid concentration as a function of time were plotted to generate FIG. 3. Also, it is important to note the increased acidification of the salt as the testing time increased. This is the result of H + ions leaking into the salt compartment.
Test 2
In accordance with the basic concept of the present invention, mixed salts of KF and KNO 3 were supplied to the three-compartment electrodialytic water splitter described above. The three-compartment electrodialytic water splitter was operated under the following conditions:
______________________________________ Current = 1.90 A Δ E = 13.6 (v) min T = 28-37° C.______________________________________
In addition to analysis for acidity, the acid and salt were analyzed by ion chromatography for F - and NO 3 - . Results are tabulated in Table 3 below:
TABLE 3______________________________________SaltTime(s) Meq/g H.sup.+ % F % NO.sub.3 Volume (mL)______________________________________ 70 .003 5.26 2.43 3861715 .012 5.09 1.02 3683560 .006 4.28 0.24 3555560 .004 2.71 0.05 3277250 .003 1.11 0.02 309______________________________________AcidTime(s) Meq/g H.sup.+ % HF % HNO.sub.3 Volume (mL)______________________________________ 50 0.91 .93 2.89 2271715 1.27 1.14 4.57 2363515 1.62 1.61 5.06 2415530 1.99 2.33 5.14 2507210 2.25 2.90 4.92 255______________________________________
Using the experimental data from Table 3, the efficiency for salt transfer and hydrogen ion production was calculated and is graphically illustrated in FIGS. 4 and 5. From the data, it is clear that nitrate was transported in preference to fluoride ions. From the salt analysis, apparently HF 2 - is transported in preference to fluoride ion as the salt does not become very acidic during the experiment, even at high nitric acid concentrations.
Test 3
A three-compartment electrodialytic water splitter of a construction described above was charged with the following solutions:
______________________________________Base Compartment 480 mL 0.5M KOHAcid Compartment 305 mL 1% HNO.sub.3Salt Compartment 415 mL Filtrate of Sample 1(1.30% F, 3.90% NO.sub.3 .sup.-)______________________________________
The three-compartment electrodialytic water splitter was operated under the following conditions:
______________________________________ Current = 1.90 A Δ E = 15.9 (V) min T = 26-38° C.______________________________________
The process was operated in a batch mode. At the end of a batch, a portion of the acid was removed and replaced with H 2 O, and the salt was removed and replaced with fresh filtrate. The results of a three-batch test are summarized in Table 4 below:
TABLE 4______________________________________ Acid CurrentBatch (meq/g) Base N EfficiencyNo. Initial Final Initial Final Duration(s) Acid Base______________________________________1 0.16 1.32 0.54 1.25 8200 0.81 0.832 0.91 2.00 1.25 1.85 9660 0.78 0.753 1.47 1.99 1.85 2.17 5600 0.68 0.70______________________________________
The final acid from Batch No. 3 was 1.49% HF/8.52% HNO 3 at a current efficiency of about 0.7.
Test 4
A three-compartment electrodialytic water splitter of generally the same construction described above was charged with the following solutions:
______________________________________Base Compartment 500 mL 0.4 N KOHAcid Compartment 300 mL 1% HNO.sub.3Salt Compartment 500 mL Filtrate of Sample 2(0.80M KF, 0.6M KNO.sub.3)______________________________________
The three-compartment electrodialytic water splitter was operated under the same conditions as in Test 3. The process was again operated in a batch mode, with the replacement of salt solution occurring at the end of Production Batch No. 1. The results of the two batch test are reported in Table 5 below:
TABLE 5______________________________________ Acid CurrentBatch (meq/g) Base N EfficiencyNo. Initial Final Initial Final Duration(s) Acid Base______________________________________1 0.16 1.63 0.40 1.34 9500 0.89 0.902 1.14 2.19 1.34 2.05 9000 0.76 0.84______________________________________
The salt was 0.41M KF/0.01 KNO 3 after Batch No. 1 and 0.53M KF/0.03M KNO 3 after Batch No. 2. The acid after Batch No. 1 was about 0.63M HF/1.07M HNO 3 , and after Batch 2 was about 0.81M HF/1.53M HNO 3 . Note again the high currency efficiency for each batch.
EXAMPLE 3
Four batches of KF/KNO 3 filtrate were prepared from a spent process liquor for use in a five-day test. The first two batches were prepared by KOH precipitation followed by a precipitation wash with 400 ml of H 2 O. For batches 3 and 4, the precipitate was washed with 300 ml of depleted salt from previous batches and 300 ml of H 2 O. For Batches 3 and 4, base generated by electrodialytic water splitting of Batches 1 and 2 was used to prepare the salt feed with fresh KOH being added to adjust the concentration of the generated base to 2M and to make-up. After each batch run, the acid and base were drained to 500 ml. The drained acid was replaced with fresh water and the drained base was replaced with depleted salt from the previous batch. The electrodialytic water splitter employed was of the same construction as the electrodialytic water splitter used in Test 4 of Example 1. The electrode rinse flow in Batches 1 and 2 was K 2 SO 4 and in Batches 3 and 4 was 0.5M KOH. The results of the batch runs are summarized in Table 6 below:
TABLE 6______________________________________ Approximate CurrentBatch No. Duration Hr. Initial Final Efficiency______________________________________Acid (meq/g)1 23.0 0.16 1.67 .842 19.8* 0.33 1.54 --3 23.7 0.36 1.76 .814 23.2 0.42 1.84 .82Base (N)1 23.0 0.5 1.97 .852 19.8* 0.39 1.24 --3 23.7 0.34 1.30 .854 23.2 0.38 1.32 .82Salt N1 23.0 1.28 0.47 .922 19.8* 1.24 0.61 --3 23.7 1.30 0.23 .874 23.2 1.32 0.41 .89______________________________________ .sup.* Current <1.9 A for undertermined time; electrode rinse flow (through anolyte and catholyte compartments) was blocked by a precipitate of K.sub.2 SO.sub.4 2.9 hours at 1.30 A
A mathematical analysis of the solution from Batch No. 4 confirming the experimental results is summarized below:
TABLE 7__________________________________________________________________________Initial Salt (4.5 L) 0.48M NO.sub.3.sup. - ; 0.84M F.sup.- (Total by IEX ≈ 1.32M)Final Salt (3.76 L) .005M NO.sub.3.sup. - ; 0.39M F.sup.- (Total by IEX ≈ 0.4M)*IEX = Ion ExchangeΔ NO.sub.3.sup. - = 4.5 L × .48 moles/L - 3.76 L × .005moles/L = 2.14 molesΔ F.sup.- = 4.5 L × .84 moles/L - 3.76 L × .39 moles/L= 2.31 molesTotal = 4.45 moles lostTheoretical yield = 4.93 moles lostCurrent Efficiency (η) = 4.45/4.93 ≈ .90Initial Acid (2.50 L) 0.19M HNO.sub.3 ; 0.22M HF (Total H.sup.+ ≈ 0.42M)Final Acid (2.76 L) 0.94M HNO.sub.3 ; 0.97M HF (Total H.sup.+ ≈ 1.84M)Δ HNO.sub.3 = (.94) (2.76) - (.19) (2.50) = 2.12 moles HNO.sub.3 gainedΔ HF = (.97) (2.76) - (.22) (2.50) = 2.13 moles HF gainedTotal = 4.25 molesTheoretical yield = 4.93 moles gainedCurrent efficiency (η) ≈.86__________________________________________________________________________
As is quite clear from the results of applicants' experiments, the process operates at current efficiencies which are unexpectedly higher as compared to the efficiency attainable for the production of a single strong acid.
The above description gives a detailed discussion of applicants basic invention and of applicants preferred embodiments. It will be obvious to those of ordinary skill in the art that various modifications and changes and/or alterations may be made without varying the scope of the present invention as defined by the appended claims. | A process for recovering concentrated mixed acids comprising HF from mixed salts at a high efficiency is disclosed. The process comprises the steps of providing an electrodialytic water splitter comprising at least one unit cell, each cell comprising a first compartment and a second compartment, feeding an aqueous solution comprising at least two salts formed from at least two different anions to the first compartment, one of said anions being fluoride, feeding a liquid comprising water to the second compartment, passing current through said electrodialytic water splitter to produce an aqueous product comprising mixed acids formed from the different anions in the second compartment, and an aqueous salt-containing product comprising a reduced concentration of said anions in the first compartment, and recovering aqueous products from the second compartment. The process is particularly useful in the production of concentrated HNO 3 at unexpectedly high current efficiencies, and has particular utility in the area of regenerating stainless steel pickling acid mixtures comprising HF and HNO 3 . | 2 |
This application is a continuation of application Ser. No. 840,115, filed Mar. 13, 1986, now abandoned.
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
This invention relates to submersible, remotely operated vehicles (ROVs) which clean metallic surfaces and use ultrasound to measure the thickness of the metal.
2. RELATED ART
Metal which has corroded, rusted or accumulated other extraneous matter such as tar and barnacles due to submersion in water or oil, must often be inspected to insure its continued viability. Inspection requires that the metal surface first be exposed.
The metal walls of oil tanker holds are one example of such metal. When the hold is drained of oil, it is often filled with seawater. Presently, the hold walls are inspected manually while dockside by lowering a small boat and people into the hold, and having the boat manuever around the hold's perimeter while the water level in the hold is lowered. Extraneous matter attached to the metal surface at a desired inspection site is scraped away with hand tools. Once exposed, the thickness of the metal is checked.
Not only is manual inspection of oil tanker holds difficult and inefficient, the toxic fumes accumulated in the confines of the unfilled portion of the hold provide a potentially hazardous environment.
Remotely operated underwater vehicles have been used for inspection for years. Television camera have been incorporated in various ROVs and manipulator arms have been attached. The maneuverability of such ROVs in restricted areas has been limited however, and an ROV which can clean and check the thickness of metal walls in such close confines as a tanker hold has not heretofore been disclosed.
Further, the flammable materials in environments such as tanker holds makes the use of electrical equipment above the surface of the water very dangerous. All prior submersible ROV systems have employed electrical supplies located on the surface. A spark or explosion in such a supply may cause a secondary explosion. Such systems are therefore not "intrinsically safe" An intrinsically safe submersible ROV system for cleaning and inspection of metal is clearly desirable, but heretofore unknown.
SUMMARY OF THE INVENTION
The present invention is a submersible ROV which can clean extraneous material from metal walls and determine the thickness of the metal. The ROV releasably secures itself near the site to be inspected with, for example, a suction pump system. A cleaning means such as a milling tool strips the extraneous matter. The cleaning tool is moved aside and an ultrasonic head extended to measure the thickness of the metal by directing ultrasonic energy into the metal. The entire operation is conducted in full view of a camera included in the ROV.
For tight maneuvering, the cleaning and inspecting means are preferably located near the extremes of the vehicle carriage so that access by the cleaning and inspecting means will not be unduly constrained by the carriage.
Preferably, the cleaning means and ultrasonic head are disposed along a common axis so that the cleaning means can clean a site, be rotated aside, and the ultrasonic head extended along the axis to precisely contact the cleaned site.
The present invention also provides an intrinsically safe submersible, ROV metal cleaning and inspection system by combining the above described ROV with a submersible electrical power supply. The power supply is driven by a nonelectrical water motor so that no power is generated above the surface. The only link to the electronics in the deck house surface console is a fiber optic link, which is itself intrinsically safe.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a side view of an ROV in accordance with the present invention.
FIG. 2 is a front view of the ROV of FIG. 1 taken along line 2--2.
FIG. 3 is a cutaway, rear view of the ROV of FIG. 1 taken along line 3--3.
FIG. 4 is a cutaway side view of the tilt head of the ROV of FIG. 1.
FIG. 5 is a top view of the tilt head of FIG. 4 taken along line 5--5.
FIG. 6 is a block diagram of the electronics of the ROV of FIG. 1.
FIG. 7 is a cutaway of the electronics bottle of FIG. 3.
FIG. 8 is a schematic of an intrinsically safe system employing the ROV of FIG. 1 and a water driven, submersible electrical power supply.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Submersible ROV 10 of FIG. 1 includes: a means for removing (such as milling tool 12) extraneous material 14 attached to a location 16 on a metal wall or surface 18, means for viewing (such as camera 20) the site cleaned by the removing means, means for measuring the thickness of metal wall 18 (such as ultrasound head 22 and associated electronics 24) carriage means 26 for supporting the removing means, the viewing means and the thickness measuring means, means for releasably securing (such as suction cup 28 and suction pump 30, see FIGS. 2 and 6 for pump 30) carriage means 26 to metal wall 18 and means for moving (such as the thrusters 32, 34, 36 and 38) carriage means 26 in water 40. The buoyancy of ROV 10 can be adjusted by securing flotation devices and or ballast tanks to carriage 26.
Preferably milling tool 12, ultrasound head 22 and camera 20 are supported by a means (such as tilt head 42) which is movably secured to carriage 26. In particular, tilt head 42 is slidably attached to rods 44 and 46 and can rotate about pivot points 48 and 49.
Conveniently, milling tool 12 is located near the end of arm 50. Arm 50 can rotate about axis 52 in a plane parallel to the face 54 of tilt head 42, from a first position 56 to a second position 58 (see FIG. 2). Tilt arm 50 is torsionally spring loaded to the first position 56. Ultrasound head 22 is extendably secured (e.g., by a threaded shaft driven axially) to tilt head face 54 and in axial alignment (see FIG. 5) with second position 58 (i.e., the cleaning and inspecting position).
Light 60 (see FIG. 2) illuminates the inspection site 16. Light 62 is used for long range viewing only. Standoff bars 64 and 66 are a convenient way to position tilt head 42 relative to metal wall 18. Bars 63 and 65 provides added strength to carriage 26. Plates 67 and 69 secure buoyancy materials 71 and 73, respectively, to bars 63 and 65. Sonars 68 and 70 allow determination of distance in two, orthogonal directions.
Electrical power and control is provided, for example, through a power bottle 72 and an electronics bottle 74 (see FIG. 6)--both packed within the bottom of carriage 26. The following is a description of a convenient electronic circuit for use in ROV 10.
Power bottle 72 receives 120 VAC and steps that down and converts it to DC with transformer/rectifier 76 to 12 VDC. The 12 VDC supplies power to the four thruster controllers 78, 80, 82 and 84 through a high current relay in the form of a pulse width modulated signal.
Electronics bottle 74 preferably includes an input/output printed circuit board (I/O Bd. 86) for routing and controlling signals and a central processing printed circuit board (CPU board 88) which contains the control programs and executes instructions in response to commands input at a remote surface console 85 (see FIG. 8). Electronic bottle 74 also receives 120 VAC and steps it down and rectifies it in 5 v DC power supply 87 and ±15 v DC supply 89.
The I/O board 86 provides circuitry (e.g., relay/drivers) to take in the logic level (e.g., 5 v) control signals from CPU board 88 and control the 120 VAC power devices. These power devices are the thruster motors power switch (not shown), the ultrasonic probe position motor 90, the tilt head motor 92, the cleaning motor 94, suction motor 30 and lights 60 and 62.
I/O board 86 includes a bank of fiber optic modules 96 for receiving and transmitting optical data along optical down link 98 and optical up link 100, respectively. Module 96 performs opto-electrical conversion on signals input thereto. Command signals will be transmitted from a surface console along down link 98, converted to electrical signals in modules 96, transmitted to CPU board 88 along serial data bus 102. Thereafter, CPU board 88 will pass data back along interboard connect 104 to control the various ROV components through relay/drivers (not shown) on I/O board 86.
I/O board 86 includes a 120 VAC control and fusing circuit 106 for directing 120 VAC to many of the components on tilt head 42. Digital control signals from CPU board 88 will operate relay/drivers on I/O board 86 to turn these components on or off in response to command signals input at surface console 85.
A digital control circuit 108 for thrusters 32, 34, 36 and 38 is on I/O board 86. Circuit 108 responds to digital signals from CPU board 88 to selectively control the duration of the pulse width modulated power signal to the four thruster controllers 78, 80, 82 and 84.
Analog signal conditioning circuit 110 on I/O board 86 receives analog signals from depth pressure transducer 112, angular rate sensor 114, a potentiometer (not shown) indicating the angular position of tilt head 42 and a signal indicative of voltage magnitude on the 120 VAC line. The CPU board 88 has an A/D converter 116 with (typically) a larger ± voltage range than the input analog signal. Circuit 110 will scale these analog signals to the range of the A/D convertor 116 by level shifting. If the analog signal range is smaller than the range of A/D converter 116, as is often the case, such scaling will increase signal resolution.
A convenient angular rate sensor 114 is a Watson Industries single axis angular rate sensor which uses a pair of piezoelectric vibrating beam elements. Torque applied to the elements due to rotation in the water generates a signal indicative of the magnitude and direction of rotation.
CPU board 88 conveniently includes a CPU 118 (e.g., an Intel 80188 16 bit microprocessor) with additional memory afforded by electrically programmable ROM 121 and RAM 122. EPROM 121 holds the basic programming to control the ROV electronics and RAM 122 allows for in operation modifications of selected aspects of the system. Further, the operator at surface console 85 can annotate the display of the video signal from camera 20 with identification data for a particular run of ROV 10.
In addition to directing digital control signals to I/O board 86, CPU board 88 can derive azimuth from data from angular rate sensor 114 and depth from depth transducer 112 data.
RAM 122 can also store data on the route of a particular ROV run so that suspect sites on wall 18 can be easily found on future runs.
The distance that ROV 10 is from objects during its course is derived by sonars 68 and 70 and range finder circuit board 124. An amplifier circuit is included in board 124. Since the strength of a sonar return signal rapidly diminishes with distance, it is preferable to provide the rangefinder circuitry with time variable gain (i.e., TVG). TVG increases the amplifier gain as time increases to compensate for the weakness in signals being returned from remote objects, thus retaining a desired level of signal resolution. The time for the return signal to be received is, of course, indicative of the distance from the object.
Additionally, a grid scaled to represent distance can be superimposed on a video display on surface console 85. The dimensions of the grid can be varied (by CPU board 88) as the distance of ROV 10 from an object varies to give the operator real time information on the distance that camera 20 is from an object.
Camera 20 may employ a focus motor 126 (preferably controlled through I/O board 86) and a zoom lens 127. Video signals are transmitted from camera 20 along video link 128 to I/O board 86 for transmission to surface console 85.
Additional preferable features (not shown) in ROV 10 are closed loop servo systems to maintain heading and depth (located in CPU board 88), manual override of the servo-loops, and circuitry to detect water intrusion into the power or electronics bottles.
FIG. 8 displays a schematic of an intrinsically safe submersible electrical power supply 130 which is particularly suited for connection to tether 132 of ROV 10. The primary components of power supply 130 are a water driven mechanical energy source such as water driven motor 134, an electrical generator 136 for converting the mechanical energy to electrical energy, a housing 138 which is water impermeable, and a power cable 140 for transmitting electrical energy to the ROV 10.
A reaction type of water driven motor (i.e., wherein the water can discharge against a back pressure and be piped away to a convenient point) is preferred as motor 134. Motor 134 is powered solely by water pressure produced, for example, by the water supply 135 of a ship. This hydro-motive force requires no electrical source on deck and therefore minimizes the chances of sparks being released above the surface of the water.
When electrical power supply 130 is used with ROV 10, it is convenient to include a fiber optic cable 142 which couples to the surface console 85, and is co-extensive with power cable 140 between housing 138 and ROV 10 to form a single tether 132 for ROV 10. Use of a fiber optic cable 142 will also avoid passing an electrical cable from surface console 85 through a hazardous surface environment.
A more detailed description of power supply 130 is included in a U.S. patent application entitled "Submersible Electrical Power Supply", assigned to the assignee of the present application and filed on the same date as the present application, this other patent application being incorporated herein by reference.
In operation, thrusters 32, 34, 36 and 38 are activated to move ROV 10 adjacent site 16. ROV 10 can be held against wall 18 at a fixed distance by pressing standoff bars 64 and 66 against wall 18 with the thrusters. Generally light 60 will be used to properly illuminate site 16 for camera 20. Suction cup 28 will engage wall 18. Milling tool 12 is rotated to cleaning position 58 and tool 12 activated. It is preferable to have the face of tool 12 form a small angle (typically a few degrees) with the surface of wall 18 so that the blades of tool 12 will cut smoothly without "chatter".
Extraneous material 14 is removed by tool 12, thereby exposing metal wall 18. The removal operation is monitored visually with camera 20 and is terminated when wall 18 is exposed. Tool 12 is rotated via a camming surface to position 56 as ultrasound head 22 is extended to engage wall 18. Head 22 typically has a flat face which should be positioned flush against wall 18. Head 22 in conjunction with electronics 24 will then send an ultrasonic signal into wall 18. The opposite face of wall 18 will reflect a portion of the initial ultrasonic signal back to head 22. The ultrasonic electronics 24 will determine the thickness of metal wall 18 by measuring the time for the return signal.
The location of site 16 can be recorded in RAM 122 by processing data from depth sensor 11, rangefinders 68 and 70 and angular rate sensor 114. ROV 10 can disengage by retracting head 22, stopping the pump for suction cup 28, retracting cup 28 and reverse thrusting with selected thrusters.
Clearly the process can be continued to inspect all desired sites. To perform the operation in an intrinsically safe manner, power supply 130 must be submerged prior to activation of supply 130 or ROV 10.
The present invention is particularly suited for use in the holds of oil tankers, but any metal which one wants to inspect which is submerged at the time of inspection can be cleaned and its thickness measured with the present invention. Storage tanks on land or the exterior hull of a ship are examples of other metal walls which may be inspected with this invention.
The embodiment depicted in FIG. 1 affords access to tight spots by allowing tilt head 42 to run up to position 144 (or down to position 146) in FIG. 1. Where the height of carriage 26 in FIG. 1 is about 23 inches, this places ultrasound head 22 about 2 inches from the uppermost part of ROV 10. One could manuever ROV 10 to touch the upper wall of a holding tank, run tilt head 42 up bars 44 and 46, and extend head 22 to the edge of standoff bars 64 and 66. This allows head 22 to reach any point on wall 18 except for a 2 inch strip adjacent the corner of wall 18 and the top of the tank.
One could also variously position head 22 on an extended arm to allow access to even the few inches that the device of FIG. 1 cannot reach.
Note further that tilt head 42 can tilt about points 48 and 49. This allows head 22 to be extended at various angles with regard to carriage 26. However, the ultrasonic head 22 should be placed flush against the metal wall being inspected to insure accurate thickness measurements, and if the site to be inspected is curved too sharply (e.g., a corner), one will be unable to properly position head 22. The device of FIG. 1 includes 1/10 horsepower thrusters 32, 34, 36 and 38. If ROV 10 were to be used in a lake or particularly the open sea, more powerful motors are preferred.
ROV 10 can be used in oil tankers while the same are underway, thus freeing the inspection process from dockside. | A submersible ROV removes extraneous material from the surface of submerged metal with a cleaning tool and measures the thickness of the metal with an ultrasonic probe. A camera allows visual operation of the ROV. The cleaning tool and ultrasonic probe can reach areas of limited access making the ROV useful for inspecting the interior of holding tanks. A submersible, electrical power supply can be combined with the ROV to provide an intrinsically safe system which is particularly useful in environments where sparks pose a substantial hazard. | 1 |
CLAIM OF PRIORITY
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/174,518 filed May 1, 2009.
FIELD OF THE INVENTION
[0002] The present invention relates to a containment barrier, and more preferably to a barrier adapted to be stored in a dry configuration, wetted for use, and then, preferably allowed to desorb to be re-stored in the dry configuration.
DESCRIPTION OF RELATED ART
[0003] Sorb Sox™ sold at www.andax.com are a competitive product which has a compressive bandage type exterior containing textile products which absorb fluid to become a barrier, such as at a culvert, or drainage area proximate to a curb in a street. The product effectively forms a four, eight or twelve foot long 3″ diameter sausage which can be placed in an anticipated path of a spill.
[0004] Sorb Sox™, once wet, must then often be treated as contaminated waste and placed in appropriately marked containers and sent to expensive bibbed landfills.
[0005] An improvement of this prior art technology is believed to be necessary.
SUMMARY OF THE INVENTION
[0006] It is a present object of the present invention to provide an improved containment barrier.
[0007] It is another object of the present invention to a containment barrier which has a dry storage configuration and is capable of desorption in a timely manner for re-storage in the storage configuration.
[0008] It is another object of the present invention to provide a containment barrier having a plurality of compartments which may cooperate with a curb or other structure to divert fluid, at least temporarily, from entering the drains/culverts or other point of concern.
[0009] In a presently preferred embodiment of the present invention, a first fabric may be formed, preferably into a plurality of compartments by folding the fabric and then defining the compartments by sewing at desired locations. A second fabric may then encapsulate the first fabric with similar structural compartmentation once an appropriate desired amount of SAP is placed in the desired compartments. The first fabric is preferably a 100% cotton woven twill. The second fabric is preferably at least one of burlap and jute. Handles may be placed on the outer bag, for the ease of transportation.
[0010] The containment barrier, once built, is preferably activated by pouring water onto or into it, and allowing it to take shape, preferably before being installed. The barrier can prevent, or at least retard contaminants from entering a culvert or other location of interest.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings in which:
[0012] FIG. 1 is a front plan view of inner fabric prior to being folded as shown in FIG. 2 into an at least partially compartmentalized configuration;
[0013] FIG. 2 is a top perspective view showing the folding of the inner fabric;
[0014] FIG. 3 is a top perspective view of the fabric shown in FIGS. 1-3 ;
[0015] FIG. 4 is front plan view showing the compartmentalized nature of the inner bag prior to installation in an outer bag;
[0016] FIG. 5 is a front plan view of an outer fabric prior to being sewn into compartmentalized sections about the inner bag;
[0017] FIG. 6 is top perspective view showing the folding of the outer fabric;
[0018] FIG. 7 is a front plan view showing the compartmentalized nature of the outer bag with handles installed;
[0019] FIG. 8 shows a top plan view of a drainage culvert of a presently preferred embodiment of the present invention prior to installing the containment device of the presently preferred embodiment of the present invention as shown constructed in FIG. 7 ; and
[0020] FIG. 9 shows a top plan view of the drainage culvert of FIG. 8 with the presently preferred embodiment of the present invention shown in FIG. 7 installed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] In accordance with a presently preferred embodiment of the present invention, FIGS. 1-7 show construction of a containment barrier 10 . Barrier 10 may be constructed as shown and described herein.
[0022] Inner bag 12 may be formed as shown in FIG. 4 by starting with fabric 14 shown in FIG. 1 . A 100×14 inch portion of fabric 14 may preferably be folded along fold 16 to provide folded fabric 18 as shown in FIG. 2 . At specified intervals, seams A,B,C,D,E,F which may be provided perpendicularly or otherwise relative to fold 16 . Seams A,B,C,D,E,F may assist in defining chambers or compartments 20 , 22 , 24 , 26 , 28 .
[0023] Tape 30 may be used over or along seams A,B,C,D,E,F as well as along edge 32 to assist in providing compartments 20 , 22 , 24 , 26 , 28 . In fact ¼ inch topstitched tape is utilized in the illustrated embodiment. Edges 32 and possibly 33 may be sewn together after a super absorbent polymer (SAP) is added to the openings 34 , 36 , 38 , 40 , 42 . In a preferred embodiment, about 24 grams or 26 milliliters of SAP with an absorption ratio of about 1/500 is added to compartment 20 and 28 . About 30 grams or 109 milliliters may be added to compartments 22 , 24 , 26 . A molecular weight greater than one for the SAP is helpful to keep the barrier from floating. Other amounts, and other numbers of compartments and sizes could be utilized with other embodiments. After finishing the inner bag 12 , it may have a finished dimensions of about 6½×99½ inches.
[0024] It is then time to preferably add outer casing 44 over inner bag 12 . First outer material 46 may be folded along fold 48 . The dimensions may preferably be slightly greater than that of inner bag material 14 . 17×101 has been found effective. When folded, particularly with a ¾ inch foldback, the inner bag fits particularly well inside the casing 44 . Twill tape may then be utilized along seams 50 , 52 , 54 , 56 , 58 , 60 perpendicular to fold 48 . Twill tape may also be utilized along edge 62 . Loop handles 64 , 66 , 68 , 70 , 72 , 74 may be formed while employing the tape 76 and in at least one preferred embodiment, handles 66 , 68 , 70 , 72 are connected to the outer casing 44 and not sewn through inner bag 12 while handles 64 , 74 are sewn through both inner bag 12 and outer casing 44 . Other embodiments may have different constructions.
[0025] Nine to ten stitches per inch, or more or less, may be employed. The thread may be 100% polyester TXT 70 or other appropriate thread. The fabric of the outer casing 46 may be burlap or jute, such as 9 oz. fabric. The inner bag may preferably be China twill, such as 108×56 with 32 mesh weave made of 100% cotton. Stitches for the inner bag may be 100% polyester TXT 70 or other material. 9-10 stitches or more or less may be employed. Other fabrics and stitching may be utilized with other embodiments. Twisting of the inner bag 12 within the outer casing 44 may be avoided.
[0026] Once constructed, the containment barriers 10 have an air permeability greater than or equal to 28 and are preferably stored dry in a storage configuration until ready to be deployed. Barriers 10 are then wetted such as with water from a truck tank and allowed to absorb the water. They are then placed in position relative to a curb and draining such as curb 78 and drainage 80 whereby they form a barrier with the curb 78 preventing flow of fluid into the drainage 80 .
[0027] Instead as water rises (presumably contaminated water) it is directed around the drainage 80 to elsewhere. As an improvement over prior art constructions, once the barrier 10 has been utilized, it can be re-used relatively easily. By having handles, the handles 64 , 66 , 68 , 70 , 72 , 74 can be pulled under a garage door to assist in preventing flooding under a garage door. Contamination will be limited to exterior surfaces 82 of the barrier 10 . Exterior surfaces 82 may be rinsed off as the contamination should not become entrapped in the SAP since the SAP can be “pre-loaded” with water prior to installation.
[0028] After rinsing off the contamination, the barriers may desorb the water over a period of days, such as about 10-14 days of 60% or less humidity. The dry barriers 10 can then be re-stored and ready for re-use at a later date. This cannot happen with prior art Sorb Sox™ as the contamination cannot be as easily removed. They are typically placed in appropriate containers and sent to special bibbed landfills at a large cost. Instead, the applicant's product can be re-used. Once exhausted, or if the user desires to exhaust the SAP, a high pH solution can be employed to break down remaining bonds in the SAP for termination of the life of the barrier 10 .
[0029] Compartments such as compartments 22 , 24 , 26 have larger volume/mass of SAP ratio than compartments 20 , 28 . Compartments 20 , 28 help hold the barrier 10 against the curb 78 when installed. Less ballooned compartments 22 , 24 , 26 can help in some embodiments to seal against the surface of the road to prevent leakage into drainage 80 .
[0030] Due to the dry storage nature of the applicants' barrier 10 which are particularly compact and light until wetted, significant advantages can be experienced over the prior art Sorb Sox even during deployment, over and above the retrieval issues described above.
[0031] Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.
[0032] Having thus set forth the nature of the invention, what is claimed herein is: | A containment barrier is provided in a plurality of compartments, such as linearly arranged, with a supply of super absorbent polymer in each of the compartments. In a wetted configuration, the barrier can prevent the flow of fluid into a drainage, or even past a garage door. Compartments may be defined in an inner bag contained within an outer covering. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates in general to the design and construction of clamping rings which are used as an intermediary for transmitting static clamping loads from a clamping device to an object. More particularly, the present invention relates to a clamping load distributor utilized as an intermediary for holding a fuel injector body to the cylinder head of an internal combustion engine.
Many internal combustion engines, whether compression ignition or spark ignition engines, are provided with fuel injection systems to satisfy the need for precise and reliable fuel delivery into the combustion chamber of the engine. Such precision and reliability is necessary to address the goals of increasing fuel efficiency, maximizing power output, and controlling the undesirable by-products of combustion.
A unit injector is a precision device that must meter the quantity of fuel required for each cycle of the engine and must develop the high pressure necessary to inject the fuel into the combustion chamber at the correct instant of the operating cycle. Many fuel injection units utilize a mechanical linkage from the engine, such as a push rod and rocker arm, to pressurize the fuel charge and obtain the desired fuel spray pattern. The mechanical linkage interacts with a timing plunger that is disposed within a bore formed in the fuel injector for engaging an incompressible liquid fuel. This mechanical pressurization of the liquid fuel produces an extremely high fuel injection pressure, often exceeding 20,000 p.s.i. (13,800 Newtons per square centimeter).
In the past, designers of internal combustion engines have generally used a mechanical clamping device to hold a fuel injection unit on the cylinder head. One approach is to affix a clamping device, having a wishbone shaped fork at one end, to the cylinder head. The clamping device is bolted to the cylinder head. The forks on the wishbone shaped end contact the top surface of the fuel injector body in two places, thereby holding the fuel injector unit in place. A second approach is to utilize a clamping plate that engages a flange formed on the outer perimeter of the fuel injector body. The clamping plate is secured to the engine by one, or a pair of bolts, thereby drawing the flange against the engine block and holding the fuel injector unit in place.
These two approaches of fastening a fuel injector unit to an internal combustion engine have a common limitation. The common limitation being that the mechanical clamping device imparts a concentrated clamping force to a portion of the fuel injector body. Premature failure of the fuel injector unit is often attributed to the fuel injector body receiving a concentrated clamping load. The concentrated clamping forces distort the precision bores formed internal to the injector. Sliding clearance must be maintained on moving components inside the injector. The clamping load distortion necessitates an increase in the "match clearance" in the "pre-distorted state" (i.e. during the manufacturing process) to compensate for the reduced clearance during operation. This contributes to "timing plunger scuffing," and requires that excessive clearance be designed into the product.
During engine operation this excessive clearance allows "blow-by" and leakage past the plunger. This problem associated with excessive clearance must be addressed in order to effectively utilize alternate materials such as ceramics. Alternate materials having diverse coefficients of thermal expansion cause the "match clearance" to widen as thermal expansion of the parts occurs. The ability to reduce and control "match clearances" internal to the fuel injector allows the use of alternate fluids to drive the timing plungers. Current technology uses "diesel fuel" as a lubricant and a hydraulic medium to drive the injection pressures. The timing plungers can be driven and lubricated with alternative fluids such as engine lubricating oil, alcohol, gasoline, etc. The reduced match clearances advance the state of the art in fuel injector units.
In order to try and solve, or at least minimize, the foregoing problem, designers have tried different approaches. For example, there have been a variety of clamping rings, for transferring static clamping loads produced by clamping devices conceived of over the years. The following listing of references is believed to be representative of such earlier designs.
______________________________________REFERENCESPatent No. Patentee Issue Date______________________________________4,829,646 Cigolotti et al. May 16, 19894,571,161 Leblanc et al. Feb. 18, 19864,419,977 Hillenbrand Dec. 13, 19834,403,586 Taniguchi Sept. 13, 19833,387,867 Rogers June 11, 1968______________________________________Patent No. Applicant Date______________________________________French Fives-Lille Company March 10, 1939No. 838,650______________________________________
Even with a variety of earlier designs, there remains a need for a distortion reducing load ring that is easy to install and addresses the clamping distortion attributed to the transmission of a concentrated clamping force to the fuel injector body, thereby reducing the distortion of the bore formed in the fuel injector body. The present invention satisfies this need in a novel and unobvious way.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a distortion reducing load ring according to a typical embodiment of the present invention as assembled between a fuel injector body and a wishbone clamp.
FIG. 2 is a front elevational view in full section of the FIG. 1 distortion reducing load ring as assembled on the fuel injector body with the wishbone clamp removed.
FIG. 3 is a top plan view of the FIG. 1 distortion reducing load ring.
FIG. 4 is a side elevational view in full section taken along line 4--4 of the FIG. 3 distortion reducing load ring.
FIG. 5 is a side elevational view of the FIG. 1 distortion reducing load ring connected to a fuel injector body.
SUMMARY OF THE INVENTION
To address the unmet needs of prior fuel injector unit mounting devices, the present invention contemplates a load ring disposed between a fuel injector body and a clamping device, the load ring comprising: a body having a first portion and a second portion opposite to the first portion, the first portion positioned for receiving a clamping load from the clamping device, the first portion having a first radial width, the second portion constructed and arranged for contacting the fuel injector body, the second portion having a second radial width, wherein the second radial width is smaller than the first radial width, and a convex portion connecting between the first portion and the second portion.
One object of the present invention is to provide an improved distortion reducing load ring for fastening a fuel injector body on the cylinder head of an internal combustion engine.
Related objects and advantages of the present invention will be apparent from the following description.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
Referring to FIGS. 1 & 2, there is illustrated a distortion reducing load ring 20 which is designed and manufactured in accordance with the present invention. Distortion reducing load ring 20 is designed to reduce the concentrated point loading inherent with a hold down clamp 21, and transfer the static clamping load radially inward toward a central axis Y, or at least on lines parallel to central axis Y of the fuel injector body 22. The distortion reducing load ring 20 is positioned on the fuel injector unit 23 between the upper surface 24, of the fuel injector body 22, and the hold down clamp 21.
The hold down clamp 21 is provided for securing the fuel injector body 22 to a cylinder head 27 of an internal combustion engine (not illustrated). In the preferred embodiment the hold down clamp 21 includes a first end 21a that contacts upper surface 27a of the cylinder head 27. The second opposite end of the hold down clamp 21 defines a pair of forks 2lb and 21c that are formed in a spaced apart relationship with each other. A coplanar lower surface 21d of the pair of forks 21b and 21c is positioned to contact the load ring 20 when the hold down clamp 21 is mounted to the cylinder head 27. A threaded fastener 28 includes a shaft portion 28a that passes through a clearance hole 21e formed in the body of the hold down clamp 21. In the preferred embodiment the threaded fastener is a hex head bolt 28. It is further contemplated that the fastener could alternatively be a threaded rod and nut combination. The bolt 28 engages an internally threaded bore formed in the cylinder head 27. The torquing of bolt 28 transmits a hold down clamp static load through the forks 21b and 21c to the clamping load distributor 20, thereby holding the fuel injector body 22 against a deck 29 of cylinder head 27.
With further reference to FIG. 2, there is illustrated the fuel injector unit 23 having load ring 20 positioned around a portion of the outer circumference of coupling return spring 30, and contacting the upper surface 24 of fuel injector body 22. The fuel injector body 22 is formed preferably as a forged unit that includes an upstanding cylindrical portion 22a, and a central axial cavity 31 extending throughout the length of the fuel injector body 22. The axial cavity 31 is actually comprised of two coaxial and communicating cylindrical bores of different inner diameters. In the preferred embodiment the first cylindrical bore 32 is machined to within 0.000039 inch cylindricity in the fuel injector body 22 and slideably receives a timing plunger 33. At this level of precision, any distortion of the cylindrical bore 32 is detrimental to the lubrication of the timing plunger 33.
The timing plunger 33 in the preferred embodiment is formed from steel, however in an alternate embodiment the timing plunger 33 is formed of ceramic. The second cylindrical bore 34 is defined in the upstanding cylindrical portion 22a of the fuel injector body 22 and slideably receives a coupling member 35. At the exposed portion 35a of the coupling member 35, a bore 35b and a load bearing surface 35c are formed. A link 36 is disposed within the bore 35b and contacts the load bearing surface 35c for transmitting a force to the coupling member 35, to overcome the spring force of coupling return spring 30. The link 36 functions in a well known fashion and is typically in contact with a valve train camshaft (not illustrated) of the internal combustion engine. Link 36 reciprocates along the central axis Y in response to the angular position of the actuating valve train camshaft.
The coupling member 35 defines a lower surface 35d that is contactable with an upper surface 33a of timing plunger 33. In the preferred embodiment there is no mechanical fixation or attachment between the coupling member 35 and the timing plunger 33; only a compressive load is transmitted from the coupling member 35 to the timing plunger 33. However, in another embodiment there is mechanical attachment between the coupling member and the timing plunger. The compressive load transmitted from the coupling member 35 to the timing plunger 33 causes the axial movement of the timing plunger 33 which functions to pressurize a fuel charge disposed within the fuel injector unit 23.
Referring to FIGS. 3-5, there is illustrated the load ring 20 having a substantially cylindrical main body 40. In the preferred embodiment the load ring 20 is of a unitary design and is formed from a steel blank. A predetermined amount of material is removed from the steel blank, by a machining process which utilizes a turning operation, a milling operation, and a grinding process to produce the desired geometric configuration described hereinafter. In the preferred embodiment the load ring 20 is of hardened steel. Preferably the load ring has a hardness in the range of about Rockwell 50-55 C. Alternatively, the load ring 20 can be formed by any other suitable manner which provides a durable ring with the desired dimensions, such as by a sintered powder metal process or forging.
The main body 40 of the load ring 20 includes a substantially flat, first upper portion 41, and a substantially flat, second lower portion 42 that is disposed opposite of the first upper portion 41. The first upper portion 41 and the second lower portion 42 are formed substantially parallel to each other. In the preferred embodiment the first upper portion 41 is parallel to the second lower portion 42 within a tolerance of about 0.001 inch. The second lower portion 42 is disposed between a pair of spaced apart reference lines, which are parallel to the first upper portion 41. The reference lines are spaced apart 0.001 inch. The main body 40 of load ring 20 has an aperture 43 extending therethrough between the first upper portion 41 and the second lower portion 42. An internal diameter surface 43a is defined on aperture 43, and this internal diameter surface 43a is larger than the outside diameter of the coupling return spring 30 that is disposed circumferentially around the upstanding cylindrical portion 22a of the fuel injector body 22. This relative difference in diameter size permits the load ring 20 to be placed during assembly circumferentially around the coupling return spring 30.
The load ring 20 includes a longitudinal centerline X. In the preferred embodiment the main body 40 is substantially symmetrical about the central longitudinal axis X. The symmetry of the load ring allows for the ease of assembly because there is no requirement to radially position the load ring 20 before connecting the hold down clamp 21 thereto. The first upper portion 41 of the main body 40 is formed substantially transverse to the longitudinal centerline X of the load ring 20 and is adapted for receiving the forks 21b and 21c of hold down clamp 21. A static clamping load is transmitted from forks 21b and 21c to the load ring 20. In the preferred embodiment the first upper portion 41 defines a planar surface having a first radial width "s". In the preferred embodiment the first upper portion 41 defines a first annular ring. A slight chamfer 44 is formed at the junction of the aperture 43 and the first upper portion 41. The use of the slight chamfer 44 is generally known to a person skilled in the art for eliminating the negative ramifications of a sharp corner.
The second lower portion 42 contacts the upper surface 24 of the fuel injector body 22. In the preferred embodiment the second lower portion 42 defines a second annular ring having a radial width "t" of about 1/32 of an inch. It should be understood that second annular rings having other dimensions are contemplated. In the preferred embodiment the second lower portion 42 has a radial width "t" that is smaller than the radial width "s" of the first upper portion 41. Further, in the preferred embodiment the ratio of the radial width "s" of the first upper portion 41 to the radial width "t" of the second lower portion 42 is at least about 11:1. The above geometrical relationship between the first upper portion 41 and the second lower portion 42 results in the transfer of the concentrated static clamping load from the hold down clamp 21 to the upper surface 24 of the fuel injector body 22. The load ring 20 is utilized to direct the static clamping load radially inward from the hold down clamp 21 to a location parallel to the longitudinal centerline X; the location being aligned with the second lower portion 42. The movement of the clamping load towards the center of the fuel injector body 22 results in a significant decrease in the distortion of the first cylindrical bore 32 which has timing plunger 33 slideably disposed within. By decreasing the distortion of the first cylindrical bore 32 there is a corresponding reduction in the scuffing of the timing plunger 33. The reduction of timing plunger 33 scuffing minimizes or eliminates the current of timing plunger seizure.
An annular portion 50 is formed on the main body 40 and connects the first upper portion 41 and the second lower portion 42. The annular portion 50 has a convex shape thereto, and in the preferred embodiment the convex shape is substantially spherical. However, other convex shapes including hyperbolic, parabolic, and elliptical are contemplated in other embodiments. In the preferred embodiment the convex shape is formed by machining a sphere with a radius of 2.0 inches on the lower part of the steel blank. A surface grinding operation is then performed to produce the second annular ring 42. The surface grinding operation produces a precision flat surface on the main body 40 having a surface finish in the range of about 40-50 micro inches. The annular portion 50 being of a convex shape increases the load ring's 20 resistance to bending when the clamping load is applied. Further, the annular portion 50 is formed on the main body 40 radially outward of the second annular ring 42. In the preferred embodiment the annular portion 50 is formed adjacent the second annular ring 42 and continues outwardly to the cylindrical edge 51 of the main body 40.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. | A distortion reducing load ring disposed and connected between a fuel injector and a clamping device. The load ring functions as an intermediary for transmitting a static clamping load from the clamping device to the fuel injector body. The load ring includes a substantially cylindrical shaped main body having a bore extending therethrough between an upper portion and a lower portion. The upper portion of the main body being adapted for receiving a clamping load from the clamping device. The lower portion defining an annular ring for contacting the upper surface of the fuel injector body. A convex shaped portion connecting between the lower portion and the upper portion for increasing the resistance to bending of the load ring. The geometric relation of the load ring is utilized to transfer the static clamping load from the clamping device to a substantially central region of the fuel injector body. By transferring the static clamping load to a more central region of the fuel injector body there is a corresponding reduction in the failure rate of fuel injector units. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Applications No. 60/274,499, filed Mar. 9, 2001, and No. 60/297,862, filed Jun. 13, 2001. Both of these provisional applications are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to wireless data communication networks, and specifically to receivers for wireless local area networks that must operate in the presence of jamming.
BACKGROUND OF THE INVENTION
[0003] Wireless local area networks (WLANs) are gaining in popularity, and new applications are being developed. The original WLAN standards, such as “Bluetooth” and IEEE 802.11, were designed to enable communications at 1-2 Mbps in a band around 2.4 GHz. More recently, IEEE working groups have defined the 802.11a and 802.11b extensions to the original standard, in order to enable higher data rates. The 802.11a standard (including Annex G of the standard) envisions data rates over 20 Mbps over short distances in the 2.4 and 5.5 GHz bands, using Coded Orthogonal Frequency Division Modulation (COFDM). The COFDM system uses multiple subcarriers, which are modulated using phase shift keying (PSK) or quadrature amplitude modulation (QAM). The 802.11b standard defines data rates up to 11 Mbps in the 2.4 GHz band using Quadrature PSK (QPSK) or 8-ary PSK (8PSK). These modulation schemes are further described in the IEEE 802.11 standards, which are incorporated herein by reference.
[0004] Wireless modems are sensitive to unintentional jamming by high-power narrowband signals in the communication band of the desired signal. Jamming is particularly problematic in the 2.4 and 5.5 GHz bands, which have been set aside by the Federal Communications Commission (FCC) for unlicensed use. Modems operating in this range under the 802.11 standards must typically deal with strong jamming signals generated by other communication devices such as cordless telephones and Bluetooth transmitters. Receivers known in the art generally use adaptive notch filters to remove such interference. Techniques of adaptive filtering, however, suffer from slow convergence and lack the capability to deal with transient in-band jamming. Bluetooth signals, for example, hop to a new frequency in the 2.4 GHz band once every microsecond, in a hop pattern that appears random to a non-Bluetooth device. Even using very fast adaptation, every such hop in an adaptive filtering system will generally cause a burst of errors in an COFDM or M-PSK receiver.
SUMMARY OF THE INVENTION
[0005] In accordance with one aspect of the present invention, a wireless receiver applies one or more of a number of novel approaches to estimate and remove jamming interference from received Frequency Division Modulation (FDM) signals. These approaches include the following:
Detecting the frequencies at which jamming occurs, and erasing these frequencies from the processed signal before demodulating the signal to recover the data. Typically, convolutional coding is applied to the transmitted signal, and the signal is demodulated using a Viterbi decoder in the receiver. In an exemplary embodiment, certain frequencies can be erased or given reduced weights during the decoding process in a manner that permits the signal to be decoded based on the remaining frequencies. Alternatively, the principle of erasing jammed frequencies can also be applied using other demodulation techniques, as are known in the art. Detecting the phase of the jamming signal, using a phase detector, and then reconstructing the jamming signal so as to cancel it from the processed signal. The phase detector operates most effectively in this manner when the jamming signal is strong, and this method is therefore preferably used when the strength of the jamming signal prevents sufficiently complete removal solely through the preceding approach of frequency “erasure.” Due to factors such as the finite length of the time window used in transforming the received signal to the frequency domain for demodulation, the effects of a strong jamming signal in a narrow band may be felt over a much wider range of frequencies in the receiver. Cancellation of the jamming signal before transformation to the frequency domain can help to overcome this problem. Demodulating the jamming signal, when the method of modulation used in the jamming signal is known (for example, Frequency Shift Keying—FSK—modulation used for Bluetooth signals). The receiver can then accurately reconstruct the jamming signal in order to remove it from the processed signal. This approach is preferably used under the strongest jamming conditions. Active digital or analog cancellation of the jamming signal. This approach is possible when the jamming signal is “cooperative,” for example, a signal generated by a Bluetooth transmitter collocated with a FDM receiver, so that the transmitter output is known to the receiver.
[0010] A receiver configured in accordance with the present invention may include an anti-jamming controller, which monitors the jamming characteristics, and selects one of the above methods depending on the level and nature of jamming. Several jamming signals may be monitored and dealt with simultaneously in this manner. Alternatively, the receiver may be designed to implement only one these anti-jamming methods, against a single jamming signal or multiple jamming signals. If the jamming is sufficiently weak, the controller turns off the anti-jamming function.
[0011] In certain embodiments of the present invention, the phase detector used in determining the phase of the jamming signal comprises a phase-locked loop (PLL), preferably a digitally-implemented PLL. A buffer typically stores one or more blocks of samples of the incoming signal while the phase detector and jamming cancellation circuitry operates on the samples. This block-oriented mode of operation allows the PLL to be operated in non-causal fashion, running both forward and backward in time, in order to accurately estimate transitions and other parameters of the jamming signal. Alternatively, the phase detector may comprise a filter, such as a finite impulse response (FIR) or infinite impulse response (IIR) filter, with an automatic frequency control (AFC) circuit.
[0012] In further exemplary embodiments of the present invention, other techniques are used to improve the anti-jamming performance of a transmitter/receiver pair. In one such exemplary embodiment, when the receiver determines that a packet has been corrupted by jamming but that the packet header may nonetheless enable identification of the identity of the transmitter that sent the packet, the receiver sends a NACK (non-acknowledge) signal to the transmitter. The transmitter, upon receiving the NACK, retransmits the packet without back-off. Additionally or alternatively, an outer code is added to the transmitted data in each packet. Preferably, for the purpose of outer coding, each packet is divided into several code words, with Reed-Solomon codes.
[0013] Although the inventors have developed these techniques particularly for use in FDM schemes, such as those specified by IEEE standard 802.11a, the principles of these techniques may also be applied, mutatis mutandis, to processing of signals based on other modulation schemes, such as M-PSK (as specified by the 802.11b standard) and Code Division Multiple Access (CDMA) schemes. These principles may also be applied to different types of narrowband jamming signals with different modulation schemes, such as PSK modulation, QAM modulation or CDMA.
[0014] In one aspect, the present invention relates to a receiver capable of receiving a signal carrying data via multiple subcarriers at respective subcarrier frequencies. The receiver includes an anti-jamming (AJ) processor, adapted to assess jamming interference on the subcarrier frequencies and, responsive thereto, to assign respective reliability metrics to the subcarriers. The receiver further includes a demodulator adapted to demodulate the signal using the reliability metrics and thereby recover the data.
[0015] In another aspect, the present invention comprises a receiver capable of receiving a signal carrying data in the presence of jamming interference. The receiver includes an anti-jamming (AJ) processor adapted to process the received signal so as to determine a frequency, phase and amplitude of the jamming interference. A jamming cancellation circuit, coupled to the AJ processor, removes the jamming interference from the received signal responsive to the frequency, phase and amplitude determined by the AJ processor. The receiver further includes a demodulator adapted to demodulate the signal after removal of the jamming interference therefrom so as to recover the data.
[0016] In yet another aspect, the present invention comprises a method for communicating data in the presence of jamming interference. The method includes transmitting a first signal carrying the data from a transmitter to a receiver at a data transmission rate. If it is determined at the receiver that the first signal has been corrupted by the jamming interference, then a reply is sent from the receiver to the transmitter, indicating such corruption has occurred. In response to the reply, a second signal carrying the data from the transmitter to the receiver is transmitted substantially without back-off of the transmission rate. The first and second signals are then processed at the receiver in order to recover the data therefrom.
[0017] The present invention also contemplates a method for processing a received signal carrying data via multiple subcarriers at respective subcarrier frequencies. The method includes assessing jamming interference on the subcarrier frequencies. In response to the assessed interference, respective reliability metrics are assigned to the subcarriers. The signal is then demodulated using the reliability metrics so as to recover the data.
[0018] In a further aspect, the present invention relates to a method for recovering data from a signal received in the presence of jamming interference. The method includes processing the received signal so as to determine a frequency, phase and amplitude of the jamming interference. Jamming interference is removed from the received signal responsive to the determined frequency, phase and amplitude. The signal is then demodulated after removal of the jamming interference therefrom so as to recover the data.
[0019] The present invention will be more fully understood from the following detailed description of various embodiments thereof, taken together with the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a block diagram that schematically illustrates a wireless data receiver, in accordance with an exemplary embodiment of the present invention;
[0021] FIG. 2 is a block diagram that schematically illustrates an anti-jamming processor, in accordance with an exemplary embodiment of the present invention;
[0022] FIG. 3 is a block diagram that schematically illustrates a phase detector for determining the phase of a jamming signal, in accordance with an preferred embodiment of the present invention;
[0023] FIG. 4 is a block diagram that schematically illustrates circuitry for demodulating and reconstructing a jamming signal, in accordance with an exemplary embodiment of the present invention;
[0024] FIG. 5 is a flow chart that schematically illustrates a method for removing jamming interference from a signal received by a modem, in accordance with an exemplary embodiment of the present invention;
[0025] FIGS. 6A, 6B and 6 C are timing diagrams that schematically illustrate processing of signals by a modem to removing jamming interference from the signal, in accordance with an exemplary embodiment of the present invention;
[0026] FIG. 7 is a block diagram that schematically illustrates circuitry for digital active cancellation of a jamming signal, in accordance with an exemplary embodiment of the present invention; and
[0027] FIG. 8 is a flow chart that schematically illustrates a method for transmitting and receiving data packets in the presence of jamming, in accordance with an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0028] FIG. 1 is a block diagram that schematically illustrates a wireless receiver 20 , in accordance with an exemplary embodiment of the present invention. In the description that follows, receiver 20 is assumed to be part of a modem used in a wireless LAN (WLAN), operating in accordance with an COFDM modulation scheme. Exemplary schemes of this sort are those put forth by IEEE standard 802.11a, including Annex G of the standard, as noted in the Background of the Invention. The WLAN environment is assumed to be noisy and, in particular, subject to jamming interference from a variety of possible sources, such as signals generated by Bluetooth transmitters. Although the elements of receiver 20 are shown and described in terms of separate functional blocks, it will be apparent to those skilled in the art that many or even all of these blocks may be implemented in a single integrated circuit chip or in a set of such chips. Additionally or alternatively, the digital processing functions described hereinbelow may be implemented in software running on a suitable microprocessor.
[0029] Receiver 20 comprises an analog front end (AFE) 22 , which performs initial analog processing on signals received over the air, as is known in the art. The AFE filters, amplifies, and splits the signals into in-phase (I) and quadrature (Q) parts, which are digitized by analog/digital (A/D) converters 24 . Preferably, the A/D converters sample the incoming signal at a rate of 44 Msps (million samples/sec). The digitized signals are then held in an A/D buffer 26 , which is preferably configured to hold samples from two successive time segments, corresponding to two successive COFDM symbols. In terms of the 802.11a standard, this means that the buffer should hold two I/Q vectors of samples, each comprising 44*80*2 samples.
[0030] Preferably, an automatic gain control (AGC) circuit 28 reads the digitized samples in buffer 26 and analyzes the signals to control the gain of AFE 22 , as is known in the art. A preamble detector (not shown) also uses the data in the buffer to detect the beginning of a data packet and thereby control other elements of receiver 20 . The functions of the preamble detector are beyond the scope of the present patent application and are therefore omitted from the figures for the sake of simplicity.
[0031] An anti-jamming (AJ) processor 30 reads the data in A/D buffer 26 , and uses these data to reduce or eliminate the effects of jamming signals in receiver 20 . Preferably, processor 30 implements a range of different anti-jamming measures, depending on the strength and nature of the jamming signals, as described in detail hereinbelow. By holding two symbols in succession, buffer 26 allows processor 30 to analyze the incoming samples in both forward and reverse temporal directions, so as to accurately determine the phase, frequency and onset/termination of any jamming signals. When the jamming signal is strong, processor 30 reconstructs the signal and applies an AJ canceling block 32 to subtract the reconstructed jamming signal from the samples in buffer 26 . Additionally or alternatively, processor 30 may indicate that certain frequencies in the input signal should be erased, or at least treated as unreliable, when the signals are decoded.
[0032] Following jamming cancellation, the I/Q samples are frequency-corrected by a phase rotator 34 , under the control of an automatic frequency control (AFC) circuit 36 . Each symbol is then converted to the frequency domain, preferably by a Fast Fourier Transform (FFT) processor 38 . The FFT output is held in a buffer 40 , which provides input to AFC circuit 36 , as is known in the art. The FFT results are also used by AJ processor 30 in determining the frequencies of narrowband jamming signals. In the case of narrowband jammers such as a Bluetooth signal, the jamming signals typically appear as sharp peaks in the spectrum of the COFDM signals.
[0033] Based on the FFT results, a metric quantization block 42 assigns a QAM metric to each QAM symbol of the COFDM signal. The QAM metric provides an estimate of the received QAM symbol that is utilized during the decoding process described below. In addition, a channel estimator 44 generates a channel estimate by approximating the phase shift and gain applied to each subcarrier by the communication channel over which the signals are received. Assuming that the symbols were interleaved by the transmitter, a de-interleaver 46 is used to reverse the interleaving. The resultant stream of QAM metrics is then input to a decoder 48 , typically a Viterbi decoder, along with corresponding channel estimates. Subject to the anti-jamming processing described hereinafter, the decoder 48 then regenerates the transmitted bitstream on the basis of this estimated symbol and channel information.
[0034] In accordance with the invention, when channel estimator 44 has determined that certain frequencies have been corrupted by jamming, it indicates to decoder 48 that the QAM metrics of the corresponding subcarriers should be assigned a low reliability or ignored altogether in the decoding process. The reliability of the subcarriers is typically represented by respective reliability metrics applied by the decoder. The nature of FDM signal transmission with convolutional coding, together with Viterbi decoding, makes it possible to drop certain carriers at the decoding stage without losing data in the bitstream.
[0035] The bitstream output of decoder 48 is used in higher-level functions of receiver 20 , including an ACK (acknowledgment) detector 50 and a MAC (media access control) interface 52 , as are known in the art. The decoder output is also used by channel estimator 44 and by AFC circuit 36 . For the purposes of AFC, the bitstream output of decoder 48 is re-encoded, following a short chain-back and interleaving process, and is compared to the samples stored in buffer 40 in order to determine the frequency correction to be applied by rotator 34 .
[0036] FIG. 2 is a block diagram showing details of AJ processor 30 , in accordance with an exemplary embodiment of the present invention. As pictured in FIG. 2 and described hereinbelow, processor 30 provides a range of different AJ measures, which are implemented selectively by an AJ controller 60 , depending on the strength and other characteristics of the jamming signal. The measures are typically selected based on the following alternative jamming scenarios:
1. Jamming signal absent or too weak to detect. In this case, each subcarrier channel is assigned a reliability metric based on the quality of reception at the corresponding frequency. The metric is applied by decoder 48 . 2. Jamming signal is detectable, but not strong enough to reconstruct its phase and other parameters. The subcarrier channels that are jammed are assigned an erasure metric. The erasure metric is typically a reliability measure that, when applied to jammed channels, is so low as to cause decoder 48 to effectively ignore such channels. Other subcarriers receive reliability metrics based on the quality of reception, as described above. 3. Jamming signal is strong enough to allow reconstruction. In this case, an interference estimation circuit 62 reconstructs the phase and other parameters of the jamming signal, while the input signal is held in buffer 26 . Details of circuit 62 are shown in FIGS. 3 and 4 . The reconstructed jamming signal is subtracted from the input signal by adders 66 in AJ canceling block 32 . The reliability or erasure metrics of the subcarrier channels are preferably assigned or adjusted following AJ cancellation. 4. Jamming signal is strong enough to allow reconstruction, and its modulation scheme is known. This will be the case, for example, when the jamming is known to be caused by FSK signals, as are generated by Bluetooth transmitters. In this case, circuit 62 can not only estimate the phase of the jamming signal, but can actually demodulate the signal and derive other signal parameters, such as modulation index and timing. The reconstructed jamming signal is subtracted from the signal in buffer 26 , and the subcarrier metrics are assigned, as described above. 5. Jamming signal is generated by a known source, such as a Bluetooth transmitter collocated with receiver 20 . For example, it is expected that some data communication devices will be configured with both a Bluetooth modem for low-rate communications and an 802.11-compliant modem for higher-rate transmissions. In this case, a digital active cancellation circuit 64 can receive an input from the Bluetooth transmitter (or other known jamming source), and can use this input to determine precisely the anti-jamming correction to be applied by AJ canceling block 32 . Details of circuit 64 are shown in FIG. 7 .
[0042] AJ processor 30 may be configured to apply all of the above measures, or only a subset of them, depending on the expected jamming environment in which receiver 20 must operate and other factors, such as cost of the modem or other device in which the receiver is used. When multiple jamming signals are present simultaneously at different frequencies, AJ controller 60 may decide to apply different measures against different signals, depending on the jamming signals strengths and modulation characteristics. In order to reconstruct multiple jamming signals in real time, AJ processor 30 will typically comprise multiple interference estimation and cancellation circuits or modules. Although the possibility of erasing or reducing the reliability measure of jammed subcarriers (scenario 2 above) is applicable primarily to FDM receivers, the remaining alternatives for reconstructing and canceling the jamming signal at the receiver can be applied in receivers using other modulation schemes, as well, such as M-PSK modulation.
[0043] FIG. 3 is a block diagram that schematically shows details of interference estimation circuit 62 , in accordance with an exemplary embodiment of the present invention. In this embodiment, circuit 62 is based on a second-order digital phase-locked loop (PLL) 70 , which determines the phase of the jamming signal. Alternatively, other types of PLLs may be used, as described, for example, by Lindsey and Chie, in “A Survey of Digital Phase-Locked Loops,” Proceedings of the IEEE 69 (1981), pp. 410-431, which is incorporated herein by reference. Further alternatively, other means known in the art may be used to determine the phase of the jamming signal, such as a suitable finite impulse response (FIR) filter or an infinite impulse response (IIR) filter.
[0044] PLL 70 generates a waveform s(n), given by s(n)=K exp {j({circumflex over (Φ)}(n)+Φ 0 }, wherein n is the sample index, given by t=nT sample , and {circumflex over (Φ)}(n) is the estimated phase of the jamming signal at sample n. A complex multiplier 72 multiplies samples r(n) from buffer 26 , having phase Φ(n), by s*(n), to generate an error signal:
e ( n )= r ( n )• s *( n )= K ′ exp { j (Φ( n )−{circumflex over (Φ)}( n )} (1)
An arctangent converter 74 converts the I and Q components of e(n) to a phase error:
θ e ( n )=arctan ( r ( n )• s *( n )) (2)
[0045] The phase error is fed to a first amplifier 76 , with gain G 1 , and to a second amplifier 82 , with gain G 2 , via an adder 78 and an accumulator 80 . Computation of the appropriate gain values is described in an Appendix to this specification. The outputs of the amplifiers are summed by an adder 84 , and the result is summed by another adder 86 with the contents of an accumulator 88 and with a constant increment 2πf BT T sample . Here f BT is the frequency of the jamming signal, determined based on the output of FFT processor 38 . The label “BT” is used to denote that the jamming signal is generated by a Bluetooth transmitter, by way of example, but other narrowband jamming signals can be treated in like manner. The phase error stored in accumulator 88 is converted to I/Q form, by a converter 90 , to generate the new value of the signal s(n). This signal is conjugated using an inverter 92 , and is then input to complex multiplier 72 .
[0046] Assuming that PLL 70 has sufficient bandwidth to track changes in the jamming signal, the waveform s(n) provides a consistent reconstruction of the jamming signal. To determine the correct amplitude K to apply to the waveform, the phase error determined by arctangent converter 74 and the amplitude of the jamming frequency components from FFT processor 38 are fed to a gain estimator 94 . The estimator preferably uses a lookup table to determine the optimal gain value, which is applied by a gain set-up block 96 to the I and Q components of s(n) that are output by converter 90 . The result is a reconstruction of the phase and amplitude of the jamming signal, which is then subtracted by AJ canceling block 32 from the input signal in buffer 26 .
[0047] FIG. 4 is a block diagram that schematically illustrates details of interference estimation circuit 62 , in accordance with another preferred embodiment of the present invention. Here it is assumed that the modulation scheme of the jamming signal is known, allowing the jamming parameters to be accurately estimated by actually demodulating the jamming signal. In this embodiment, too, circuit 62 comprises a phase lock demodulator 100 , which is preferably similar in design and operation to PLL 70 , as described above. The phase estimate of the jamming signal is smoothed by low-pass filtering with an adder 102 and a delay stage 104 . Based on the phase estimate, a parameter estimation block 106 determines other parameters needed to reconstruct the jamming signal, including its modulation index k and its start and stop times. An interference reconstruction block 108 uses the signal phase and the other parameters provided by block 106 to generate the reconstructed jamming signal output s(t).
[0048] For the specific example of a Bluetooth jamming signal, with Gaussian FSK (GFSK) modulation, the modulated jamming signal can be represented as:
v ( t ) = 2 E T exp { j ( Φ ( t ) + Φ 0 ) } ( 3 )
Here E is the signal energy, and T is the symbol period (1 μs for Bluetooth signals). The continuous phase of v(t) is given by:
Φ ( t ) = ω t + 2 π k ∫ - ∞ t m ( η ) ⅆ η + θ ( 4 )
wherein m(t) is the modulating signal, k is the modulation index, ω is the center frequency of the Bluetooth signal, and θ is the random phase of the Bluetooth signal.
[0049] In Bluetooth GFSK, the modulating signal is the result of filtering a NRZ (non-return to zero) sequence of the input data bits with a Gaussian filter whose time impulse response is:
h G ( t ) = π α exp ( - π 2 α 2 t 2 ) , α = 2 ln 2 B ( 5 )
where B is the 3 dB bandwidth of Gaussian filter. The modulating signal can then be expressed as:
m ( kT Sample ) = ∑ n = - ∞ ∞ x ( ( k - n ) T Sample ) h G ( nT Sample ) ( 6 )
wherein x(nT Sample ) is the sampled NRZ input signal. In an exemplary implementation of the receiver 20 , the A/D converters 24 operate to sample the NRZ input signal at the rate of 44 Msps.
[0050] Given the phase information and signal parameters determined by blocks 100 and 106 , the estimated jamming signal reconstructed by block 108 will have a complex envelope of the form:
s ( t ) = K exp { j ( Φ ^ ( t ) + Φ 0 ) } = K exp { j ∑ - n 0 NT s ( h G ( n ) * θ e ( n ) ) } ( 7 )
where T s is used for brevity to denote T sample . It will be seen that s(t) is, essentially, a delayed version of the original jamming signal given by equation (3). Preferably, equation (7) is used to construct a lookup table, which is used by block 108 in reconstructing s(t).
[0051] Reference is now made to FIGS. 5 and 6 A-C, which schematically illustrate methods for determining the phase of a jamming signal, in accordance with an exemplary embodiment of the present invention. FIG. 5 is a flow chart, showing the steps carried out by AJ processor 30 and other elements of receiver 20 in estimating parameters of the jamming signal. FIGS. 6 A-C are timing diagrams, showing the timing of processing stages involved in the phase estimation methods of FIG. 5 . FIG. 6A shows the processing stages involved when a jamming signal was present during the preceding COFDM symbol received by receiver 20 and continues through the present symbol; FIG. 6B shows the stages when a jamming signal present during the preceding COFDM symbol terminates at the present symbol; and FIG. 6C shows the stages when a jamming signal is detected initially during the present symbol, without its having been detected at the preceding symbol.
[0052] The methods illustrated by these figures take advantage of the block-oriented processing structure of receiver 20 . In accordance with this structure, during the time a block of samples is stored in buffer 26 , AJ processor 30 can run a phase detector on the samples at least twice—once in a forward time direction, and once in reverse. This forward/backward operation is advantageous in improving the phase detection performance of interference estimation circuit 62 , including removal possible bias and phase distortion that can accumulate when conventional unidirectional phase estimation is used. It is particularly useful in finding start and stop times of the jamming. In the description that follows, reference is made to PLL 70 as an example of a phase detector than can be run in a bi-directional manner, but the methods of FIGS. 5 and 6 A-C can similarly be applied using phase detectors of other types.
[0053] The method of FIG. 5 is initiated each time a block of samples corresponding to a new COFDM symbol is received in buffer 26 , at a symbol reception step 110 . This new symbol is referred to in FIGS. 6A-6C as COFDM Symbol N-1. The subsequent steps taken by AJ processor 30 depend on whether or not a jamming signal was detected at the previous symbol, as determined at a previous symbol status step 112 . If a jamming signal was detected at the previous symbol, PLL 70 runs over the samples in both forward and reverse directions, at a PLL running step 114 . For efficient convergence of the PLL, the jamming signal frequency is held at the same value as it had at the preceding symbol, and the initial phase values in accumulators 80 and 88 are also set to the values determined at the conclusion of processing of the preceding symbol. After running PLL 70 , the power and phase of the jamming signal are estimated, as described above, at an estimation step 116 . If the jamming signal terminates during Symbol N-1 ( FIG. 6B ), the transit time (i.e., the identification of the sample during the symbol interval at which the jamming terminated) is also estimated.
[0054] Based on the power and phase estimates determined at step 116 , the jamming signal is reconstructed and subtracted out of the current block of samples by AJ cancellation block 32 , at a jamming erasure step 118 . After subtraction of the jamming signal and frequency correction by rotator 34 , FFT processor 38 operates to transform the symbol to the frequency domain, at a FFT step 120 . AJ controller 60 checks the frequency spectrum of the symbol to confirm the existence and removal of the jamming signal, as well as to determine the residual level of interference at the jamming frequency and in other FDM frequency bins. The AJ controller accordingly issues reliability or erasure metrics for these bins, to be applied by Viterbi decoder 48 , at a bin update step 122 . To the extent that the jamming terminated during the current symbol, the next symbol is processed assuming, at step 112 , that no jamming signal was detected during the preceding symbol. The absence of a jamming signal during the next symbol is preferably verified by the FFT performed on the samples of the next symbol.
[0055] When a new jamming signal is detected in the current symbol at step 112 , without the jamming signal having been present in the previous symbol, the frequency and amplitude of the new jamming signal must be estimated before further processing can take place. These estimates are made by running a FFT on the raw samples in buffer 26 , at a preliminary FFT step 124 . Based on the FFT spectrum, the center frequency and gain of the jamming signal are found, at a frequency determination step 126 . Using this information, PLL 70 is run on the samples of the current symbol in a forward direction, then in reverse, and then forward again, at a PLL rerunning step 128 . The results of step 128 are used to estimate the power, phase and start time of the jamming signal during the current symbol, at a start estimation step 130 .
[0056] The estimated parameters of the jamming signal are used to correct the COFDM samples at step 118 . The FFT performed on the corrected samples at step 120 is, in this case, the second FFT performed on the samples of the current symbol. As in the previous case, the FFT enables AJ controller to confirm the jamming frequency (to be used in processing the next symbol, as well) and to determine the metrics to be passed to decoder 48 . Because of the delay in carrying out the second FFT at step 120 , as exemplified by FIG. 6C , PLL 70 is preferably run on the next block of samples first in the reverse direction, and only afterwards in the forward direction.
[0057] FIG. 7 is a block diagram that schematically shows details of active cancellation block 64 ( FIG. 2 ), in accordance with an exemplary embodiment of the present invention. As noted above, this block is used when there is an actual link or similar cooperative relationship established between receiver 20 and a source of jamming interference, such as a Bluetooth transmitter 152 collocated with the receiver.
[0058] In order to cancel the Bluetooth jamming signal out of the samples of the COFDM symbol, the samples from buffer 26 are input to a complex negative rotator 140 . In operation, the negative rotator 140 functions to frequency align the Bluetooth jamming signal with the baseband Bluetooth transmit signal in order to facilitate establishment of time alignment therebetween. Delay blocks 142 and 144 apply successive delays of T/2 to the samples, wherein T is the Bluetooth symbol period. The samples and their delayed counterparts are then input to a bank of correlators 146 , 148 and 150 for correlation with delayed versions of the actual signals generated by Bluetooth transmitter 152 provided by a T/2 delay block 156 . For purposes of clarity, the output of the T/2 delay block 156 is not explicitly depicted as being separately connected to each correlator 146 , 148 and 150 . The results of early correlator 146 , which operates on the undelayed samples, and of late correlator 150 , which operates on the results delayed by T, are input to absolute value blocks 160 and 162 , which provide the real square amplitudes of the complex correlation values. The amplitudes are summed together by an adder 164 and provided to early late filter 158 .
[0059] Meanwhile, the actual signals generated by Bluetooth transmitter 152 are delayed by a variable delay block 154 . The length of the delay is determined by an early/late filter 158 . The delayed signals are subjected to an additional T/2 delay, by a fixed delay block 156 . The delayed signal output from block 154 is combined with the output of on-time correlator 148 by a phase shift determination block 166 , to find the phase shift of the modulation of the Bluetooth signal relative to the COFDM symbols. This phase shift is applied to a complex positive rotator 168 in order to generate the reconstructed Bluetooth signal for subtraction from the COFDM samples by AJ cancellation block 32 .
[0060] Although the preferred embodiments described above make particular reference to FDM schemes, such as those specified by IEEE standard 802.11a, the principles of these techniques may also be applied, mutatis mutandis, to processing of signals based on other modulation schemes, such as M-PSK (as specified by the 802.11b standard) and Code Division Multiple Access (CDMA) schemes. Similarly, although these preferred embodiments deal by way of example with interference caused by Bluetooth transmitters, the methods of the present invention support coexistence of WLANs with multiple narrowband jamming sources with frequency modulation signals. The principles of the present invention may also be applied to other narrowband jammers with different modulation schemes, such as PSK modulation, QAM modulation or CDMA. In such cases, when the modulation scheme of the jamming source is known, interference estimation block 62 and active cancellation block 64 make use of the particular modulation characteristics of the jamming signal, instead of the GFSK characteristics of Bluetooth. Adaptation of the designs shown in FIGS. 4 and 7 to operate with other modulation schemes will be straightforward for those skilled in the art.
[0061] FIG. 8 is a flow chart that schematically illustrates a method for transmitting and receiving packets over a WLAN in the presence of jamming, in accordance with another preferred embodiment of the present invention. This method relies on a novel protocol, which is implemented by a transmitter and receiver in the WLAN independent of any other AJ measures that may be used in the receiver, such as those described with reference to the preceding figures. Present WLAN protocols, such as those specified by IEEE standards 802.11a and 802.11b, provide for the transmitter to back off (i.e., to reduce) its transmission rate when it determines that packets are being lost due to interference. The reduced transmission rate makes it easier for the receiver to decode the packets, but of course, it reduces the throughput of the data link. While this step may be necessary in the presence of broadband interference, it is unnecessarily severe when only narrowband jamming is concerned.
[0062] Thus, when the receiver determines that a portion of the data in a packet have been corrupted, at a packet reception step 170 , it does not immediately discard the packet, but rather tries to determine the source of the packet and the reason for the data corruption. The receiver attempts to identify the source of the packet by deciphering the source address, typically a MAC address, in the packet header, at an address reading step 172 . If the address is indecipherable, the packet is simply discarded, in accordance with existing protocols, at a discard step 174 .
[0063] On the other hand, if the receiver is able to read the packet source address, and determines that the corruption of the data in the packet was due to jamming, the receiver sends a NACK (non-acknowledge) signal to the transmitter, at a NACK step 176 . The NACK signal tells the transmitter to retransmit the packet without back-off, at a retransmission step 178 . When the retransmitted packet is received, it may be uncorrupted, particularly if the jamming has abated. On the other hand, if the jamming signal continues, the retransmitted packet may also contain corrupted data, but it is probably a different portion of the data from that which was corrupted in the initial packet. Thus, at a decoding step 180 , the receiver decodes the entire contents of the retransmitted packet, with the assistance of the data from the initial packet. In this manner, the jamming interference is overcome, with a less drastic reduction of data throughput than is caused by protocols known in the art.
[0064] Other techniques may also be used to improve the throughput of COFDM transmissions in the presence of jamming. For example, the number of subcarrier channels used may be increased from the 64 frequencies provided by the 802.11a standard to 128 frequencies, provided that sufficiently accurate frequency estimation is used to maintain orthogonality between the channels. Alternatively or additionally, an outer code may be added to the transmitted data in each packet, to be used in reconstructing COFDM symbols that are erased due to jamming. Preferably, for the purpose of outer coding, each packet is divided into several code words with Reed-Solomon codes. For this same purpose, repeat transmission of the symbols may be used, at the cost of reducing the maximum data rate. For example, the transmitter may use a 16 QAM, rate 2/3 convolutional code with repetition, in place of the 16 QAM, rate 1/2 code specified by the standard.
[0065] It will be appreciated that the preferred embodiments described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art.
APPENDIX—COMPUTATION OF PLL PARAMETERS
[0066] Attention is drawn to the above-referenced Provisional Patent Application No. 60/297,862, which describes computation of various parameters and initial conditions pertinent to operation of the DLL 70 of FIG. 3 . | An embodiment of the present invention provides a method for communicating data in the presence of jamming interference, comprising transmitting a first signal carrying the data from a transmitter to a receiver at a data transmission rate, determining at the receiver that the first signal has been corrupted by the jamming interference, sending a reply from the receiver to the transmitter, indicating that the first signal was corrupted, responsive to the reply, transmitting a second signal carrying the data from the transmitter to the receiver substantially without back-off of the transmission rate, and processing the first and second signals at the receiver to recover the data therefrom. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The priority of European Patent Application EP04380274.3 filed Dec. 27, 2004 is hereby claimed under the provisions of 35 USC § 119.
FIELD OF THE INVENTION
[0002] The present invention relates to the asymmetric reduction of ketones using chiral catalytic systems to render nonracemic chiral alcohols. More particularly, it relates to a new process for the preparation of the pure enantiomers of an intermediate alcohol which is used in the preparation of Cizolirtine, (±)-2-[phenyl(1-methyl-1H-pyrazol-5-yl)methoxy]-N,N-dimethylethanamine and its enantiomers, comprising the enantioselective hydrogenation of a prochiral ketone.
BACKGROUND OF THE INVENTION
[0003] The compound (±)-2-[phenyl(1-methyl-1H-pyrazol-5-yl)methoxy]-N,N-dimethylethanamine, also referred to as (±)-5-[α-(2-dimethylaminoethoxy)benzyl]-1-methyl-1H-pyrazole, or Cizolirtine of formula (I)
was described in the European patent EP 289 380. This compound is a potent analgesic which is currently in phase II clinical trials.
[0004] The two enantiomers of Cizolirtine, hereinafter referred to as (+)-I and (−)-I, have been previously obtained by optical resolution of the Cizolirtine racemate by fractional crystallization with optically active acids (WO 99/02500) such as, for instance, with (−)- and (+)-di-p-toluoyltartaric acid (Torrens, A.; Castrillo, J. A.; Frigola, J.; Salgado, L.; Redondo, J. Chirality, 1999, 11, 63). An enantiomerically pure compound synthesis (EPC synthesis) starting from ethyl (R)-mandelate of the intermediate permitted the assignation of the (R) absolute configuration to the (+)-I isomer (Hueso-Rodriguez, J. A.; Berrocal, J.; Gutierrez, B.; Farre, A.; Frigola, J. Bioorg. Med. Chem. Lett. 1993, 3, 269).
[0005] The (±)-Cizolirtine has been prepared by O-alkylation of compound (±)-II of formula II:
[0006] The pure enantiomers of Cizolirtine (+)-I and (−)-I may be prepared by separately O-alkylating the enantiomerically pure intermediates (+)-II and (−)-II.
[0007] The enantiomerically pure compounds (+)-II and (−)-II are obtained either by reduction of a compound of formula III, which yields (±)-II as a racemate, followed by procedures of optical resolution of the racemate (±)-II, like fractional recrystallization from solvents or column chromatography [J. A: Hueso, J. Berrocal, B. Gutierrez, A. J. Farré y J. Frigola, Bioorg. Med. Chem. Lett. 1993, 3, 269], or by EPC synthesis starting from the prochiral ketone of formula III:
[0008] The enantioselective reduction of prochiral ketones in organic synthesis to obtain secondary alcohols with high enantiomeric purity is of high interest since they can be valuable intermediates for the manufacture of active compounds. Accordingly, a number of strategies for the asymmetric reduction of prochiral ketones to single enantiomer alcohols have been developed [R. Noyori, T. Ohkuma, Angew. Chem. Int. Ed., 2001, 40, 40-73].
[0009] A possibility exists in the use of oxazoborolidines as ligands or catalysts which constitutes a major advance in the asymmetric reduction of prochiral ketones. The use of said chiral ligands or catalysts in combination with achiral reducing agents for the preparation of (+)-I and (−)-I has been described in patent EP 1 029 852 B 1. Further examples can be found in the literature [E. J. Corey, Ch. J. Helal, Tetrahedron Lett. 1995, 36, 9153-9156; E. J. Corey, Ch. J. Helal, Tetrahedron Lett. 1996, 37, 5675-5678].
[0010] However, for diaryl methanols, the reduction of the corresponding ketone precursors is problematic. The chiral catalyst has to differentiate between the two aromatic rings. This can usually only be done with high selectivity if the two rings are different in terms of steric and/or electronic properties which is not obvious in the case of Cizolirtine.
[0011] The main strategy for the enantioselective reduction of aromatic and heteroaromatic prochiral ketones with high ee values comprises the use of an optically active diphosphane/Ru/-iamine/inorganic base catalyst system. Moreover, there are also examples with rhodium [K. Kriis, T. Kanger, A.-M. Müürisepp, M. Lopp, Tetrahedron: Asymmetry 2003, 14, 2271-2275.] or cobalt [K. Micskei, C. Hajdu, L. A. Wessjohann, L. Mercs, A. Kiss-Szikszai, T. Patonay, Tetrahedron: Asymmetry 2004, 15, 1735-1744] as metal for the asymmetric reduction of prochiral ketones.
[0012] Enantioselective hydrogenation of ketonic structures has been achieved with also a wide range of chiral ruthenium catalyst systems which can be prepared by different combinations of Ru (II) chiral phosphanes and diamine ligands. The extent of the enantioselectivity obtained with the different ketones depends largely on the nature of the substituents of the prochiral ketone as shown by the state of the art [see, for instance, Table 2, on p. 53: R. Noyori, T. Ohkuma, Angew. Chem. Int. Ed. 2001, 40, 40-73]. It is also known that heteroaromatic ketones can be enantioselectively hydrogenated to nonracemic secondary alcohols with these chiral ruthenium catalysts systems [C. Chen, R. A. Reamer, J. R. Chilenski, C. J. McWilliams, Org. Lett. 2003 5, 5039]. One finds further asymmetric hydrogenations with ketones with a phenyl and a heteroaryl in the literature [K. Okano, K. Murata, T. Ikariya, Tetrahedron Lett. 2000, 41, 9277-9280].
[0013] However it has been found that one specific catalyst or a class of catalysts cannot be used equally well in all hydrogenations. Thus, to attain satisfactory ee values by the enantioselective hydrogenation of prochiral ketones, each hydrogenation problem has to be investigated separately with regard to the substrate, the catalyst and the reaction conditions for finding the optimal conditions to obtain the best results.
SUMMARY OF THE INVENTION
[0014] The present invention provides a process for the enantioselective hydrogenation of a phenyl pyrazoyl ketone, which operates particularly well on an industrial scale, is satisfactory as regards yield, conversion and enantiomer excess, and advantageously provides specific enantiomer-enriched alcohols as intermediates for the preparation of (+)- and (−)-Cizolirtine.
[0015] Surprisingly, the inventors have achieved the enantioselective hydrogenation with a chiral ruthenium (II) catalyst system of a prochiral ketone with a phenyl and a methyl-pyrazol substituent comprising two nitrogen atoms, with high ee value and high conversion. Investigations carried out by the inventors have shown in a no way foreseeable manner that the prochiral ketone with a phenyl and a methyl-pyrazol substituent provides the catalytical enantioselective hydrogenation of said ketone with high enantioselectivity and conversion. This could not have been predicted from the nature of the substrate. We therefore have applied this process to the synthesis of the enantiomerically pure intermediates (+)-II and (−)-II and to a process to obtain Cizolirtine and its enantiomers. This process is contemplated as operating particularly well on an industrial scale and in a satisfactory manner with regard to enantiomer excess, amount and availability of catalyst, and raw material costs in general.
[0016] More specifically, the present invention is directed to a process for the preparation of an enantiomerically enriched compound of formula (II):
in which the process includes the asymmetric hydrogenation of a prochiral ketone of formula (III)
in the presence of a base and a chiral ruthenium (II) catalyst system including at least a bidentate phosphorous-containing ligand and a diamine ligand.
[0017] The above-described process allows the preparation of the known intermediates of formula II, which can be optionally transformed in enantiomerically pure pharmaceutically active compounds such as (+)-Cizolirtine and (−)-Cizolirtine.
[0018] Other aspects, features and embodiments of the invention will be more fully apparent from the ensuing disclosure and appended claims.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The process of the present invention gives the desired product of formula II with high conversion and enantiomeric excess. This process has the further advantage that the starting materials are not expensive and that it works under low or normal pressures. Similar hydrogenations are known, as mentioned above, but for the first time they have been applied by the present inventors to a pyrazol containing substrate. Although problems due to the coordination of the pyrazol were expected, on the contrary we have found that the reaction works remarkably well providing a simple route to the alcohols of formula (II) with high conversion and enantiomeric excess. The process of the invention allows the compounds of the above formula (II) to be synthesized directly from the compounds of formula (III), without any further intermediate steps or laborious separation of the isomeric forms.
[0020] The product of formula II is especially useful in the preparation of Cizolirtine enantiomers. The details of the process are discussed below.
[0021] The chiral ruthenium (II) catalyst system used in the process of the present invention is known to the person skilled in the art and is composed of Ruthenium (II) complexes with two different ligands, a bidentate phosphorous-containing ligand and a diamine, in the presence of a base. Such catalyst system components can be provided to the reaction mixture individually to form the reactive catalyst system in situ, or they can be provided as preformed complexes.
[0022] The bidentate phosphorous-containing ligand is in general of the biphosphines or biphosphites types, and more preferably it is of the biphosphine type. Illustrative examples of nonracemic chiral diphosphines include 2,2′-bis(diphenyl-phosphino)-1,1′-binaphtyl (BINAP), ToIBINAP and XylBINAP [R. Noyori, T. Ohkuma, Angew. Chem. Int. Ed., 2001, 40, 40-73], 2,2′-bis(diphenylphosphino)-1,1′-dicyclopentane (BICP) [P. Cao, X. Zhang, J. Org. Chem. 1999 64, 2127-2129.], 2,2′,6,6′-tetramethoxy-4,4′-bis-3,3′-bipyridine (P-Phos), Tol-P-Phos and Xyl-P-Phos [J. Wu, H. Chen, W. Kwok, R. Guo, Z. Zhou, C. Yeung, A. S. C. Chan, J. Org. Chem. 2002, 63, 7908-7910], 4,12-bis(diphenylphosphino)[2.2]paracyclophane (PhanePhos) and Xyl-PhanePhos [M. J. Burk, W. Hems, D. Herzberg, C. Malan, A. Zanotti-Gerosa, Org. Lett. 2000, 2, 4173-4176] and equivalents thereto that are recognized by those skilled in the art.
[0023] In one preferred embodiment the diphosphine ligand comprises a binaphthyl group. More preferably, the diphosphine ligand is selected from the group consisting of the enantiomers of 2,2′-bis(diphenyl-phosphino)-1,1′-binaphtyl (BINAP), TolBINAP and XylBINAP [see R. Noyori, T. Ohkuma, Angew. Chem. Int. Ed., 2001, 40, 40-73].
[0024] Suitable diamines include 1,2-diamine species that exhibit a sufficient activity or selectivity in the catalyst under consideration. They can be chiral or non-chiral. Ilustrative examples include any stereoisomers of 1,1-bis(4-methoxyphenyl)-3-methyl-1,2-butanediamine (DAIPEN), 1,2-diphenylethylendiamine (DPEN), 1,2-diaminocyclohexane (DACH) or achiral diamines such as ethylenediamine. Achiral amines are further discussed in U.S. Pat. No. 6,743,921, the disclosure of which hereby is incorporated herein by reference in its entirety.
[0025] The use of enantiomerically enriched diamines such as DAIPEN and DPEN has proved particularly advantageous, with DPEN being most preferred as regards costs and higher activity and selectivity.
[0026] The bidentate phosphorous-containing ligand together with the diamine and the ruthenium (II) form a complex referred to hereinafter as the ruthenium (II) component of the catalyst system. Examples of preformed complexes of the ruthenium with the diphosphine ligand and the diamine include complexes represented by the formula RuX 2 LA wherein X represents a halogen atom or pseudo-halide group, preferably chloride or bromide, L represents the diphosphine ligand and A is the diamine. Illustrative examples include RuCl 2 [(S)-BINAP][(R,R)-DPEN], RuCl 2 [(S)-BINAP][(S,S)-DPEN], RuCl 2 [(R)-BINAP][(R,R)-DPEN], RuCl 2 [(R)-BINAP][(S,S)-DPEN], RuCl 2 [(R)-BINAP][(R)-DAIPEN], RuCl 2 [(S)-BINAP][(S)-DAIPEN].
[0027] Such component is present in catalytic amounts, meaning less than stoichiometric relative to the ketone reactants and as low as possible while ensuring the optimum possible conversion rate. The minimum amount of the ruthenium (II) component of the catalyst system may depend on the activity of the specific catalyst system composition, the reaction temperature, the concentration of the reactants and catalyst system components in the solution, the hydrogen pressure and the maximum time allowed for completion of the reaction. In a typical embodiment, the molar ratio of the ruthenium (II) component of the catalyst to the ketone reactant (s/c) is in the range of from about 50 to 20,000, preferably from about 200 to about 20,000, and more preferably from about 10,000 to about 20,000.
[0028] Suitable bases include organic bases and inorganic bases, which should not have a negative influence on, for example, the enantiomer purity of the products that are formed. Preferably, the base is selected from the group consisting of hydroxide, C 1 -C 5 -alkoxide, bicarbonate, carbonate, di- and tribasic phosphate, borate, fluoride, amine optionally substituted with C 1 -C 4 -alkyl or aryl, and silane optionally substituted with C 1 -C 3 -alkyl.
[0029] In this connection alkali metal alcoholates are advantageous, such as for example t-BuOK, as well as inorganic bases such as for example KOH or K 2 CO 3 . Also used are organic nitrogen bases such as NEt 3 and salts as for example AgCF 3 SO 3 . In a more preferred embodiment t-BuOK is used. When the base used is t-BuOK it is preferably added to the reaction vessel in form of a solution of t-BuOK in t-BuOH.
[0030] It has been found that a molar excess of base referred to the ruthenium (II) component of the catalyst system is advantageous. The typical mole ratio of base:ruthenium (II) component of the catalyst system is in a range of from 10:1 to 1:1, more preferably in a range of from about 4:1 to about 2:1. It has been found that both the activity and the selectivity of the hydrogenation vary with the amount of the base. In this respect, the activity of the hydrogenation increases with rising concentration of the base. However, if the concentration of base is too high, there is a possibility of racemization of the end product, which is not desirable. A ratio in the vicinity of about 4:1 is particularly preferred.
[0031] The hydrogenation reaction advantageously is conducted in a solvent system that is capable of dissolving the catalyst system and is reaction-inert. The term solvent system is used to indicate that a single solvent or alternatively a mixture of two or more solvents can be used. The term reaction-inert is used to mean that the solvent system does not react unfavourably with the reactants, products, or the catalyst system. The solvent system need not bring about complete solution of the ketone reactant or the chiral alcohol product. The ketone reactant may be incompletely dissolved at the beginning of the reaction or the chiral alcohol product may be incompletely dissolved at the end of the reaction, or both. Representative solvents include alcohol solvents such as methanol, ethanol, n-propanol, 2-propanol, n-butanol, sec-butanol or t-butanol and their mixtures, organic solvents containing heteroatoms such as DMF and ethers such as THF. Preferably the solvent system comprises an alcohol solvent, more preferably an alcohol solvent selected from the group consisting of methanol, isopropanol, t-butanol and their mixtures. Tert-butanol is a particularly preferred solvent species.
[0032] The hydrogenation takes place in a suitable reactor, e.g., a reactor of a type known to the person skilled in the art, such as an autoclave. It is advisable to carry out the hydrogenation under an inert gas atmosphere. Suitable media include, without limitation, nitrogen gas or a noble gas such as argon.
[0033] The temperature during the reaction may in principle be chosen arbitrarily by the person skilled in the art, as long as a sufficiently quick and selective reaction is achieved. However, it has to be taken into account that the temperature depends strongly on solvent and that some catalyst systems are unstable above 40° C. In typical embodiments, the reaction is suitably conducted at temperature in a range of from 10 to 45° C., preferably between 20 and 35° C., and most preferably at about 30° C.
[0034] The term hydrogenation as used herein refers to reacting the ketone with a source of hydrogen atoms under appropriate conditions so that two hydrogen atoms are added to the carbonyl group of the ketone to produce the hydroxyl group of the chiral alcohol. Preferably the source of hydrogen atoms includes molecular hydrogen (H 2 ). If the hydrogenation is carried out in the presence of molecular hydrogen, the hydrogen pressure in the reaction is preferably low, typically at least about 1.3 atm. More generally, pressure can be in a range of from 0.8 to 100 bar. In a preferred embodiment, the hydrogen pressure is in the range of from 1.3 to 8 bar.
[0035] The ketone of formula (III) is known and can be prepared as described for example in International Patent Publication WO99/07684 or by any other suitable method readily apparent to the person skilled in the art. Normally, the ketone substrate (III), the catalyst system and the base (if it is a solid) are weighed and introduced in the reactor. Then the solvent is added and stirred to complete dissolution of the catalyst. Thereafter the base, if not a solid, is added. The reactor is brought to adequate temperature and pressure to complete the reaction. Alternatively, the ketone of formula (III) is dissolved in an appropriate solvent, then the constituents of the catalyst system or the catalyst in preformed form are added, and then the hydrogenation is performed at appropriate temperature and suitable hydrogen pressure.
[0036] The ketone concentration ranges from about 0.025 to 0.1 mol/l, and preferably from about 0.05 to about 0.1 mol/l. In general the reaction is allowed to continue until complete conversion of the ketone is achieved. Reaction time in a range of from 1 to 110 hours is generally sufficient, although shorter times are preferred in terms of economy of the process.
[0037] The advantages associated with the invention are numerous. The process according to the invention provides a simple means of access to isomers which were previously relatively difficult to obtain, and also allows this to be done on a large industrial scale with excellent productivity. The process according to the invention makes it possible to prepare the desired product not only in high yields but also with very high enantioselectivity. No additional purification steps are needed, and the products may be further processed directly just as they occur.
[0038] Conversions of 100% of the ketone are achieved by the process of the present invention. The enantiomeric proportions achieved by the process of the invention are above 80 ee % and can be as high as 82 ee %. Since the constituents of the catalyst (diamine, ruthenium (II) and bidentate phosphorous containing ligand) may be used in several diasteromeric and enantiomeric forms and the complex in each case may therefore be present in so-called matched or mismatched configurations with regard to the chiral ketone, the person skilled in the art is able to appropriately verify which pair works most suitably as regards selectivity.
[0039] In one preferred embodiment, the process of the present invention is directed to the synthesis of each of the following alcohols of formula II with the highest possible enantiomeric purity:
[0040] Once the hydrogenation is completed, the obtained hydrogenated product, i.e., the enantiomers of the nonracemic alcohol mixtures [(+)-II and (−)-II], may be subjected to additional purification, for example one or more washing steps and/or recrystallization from the solvent used, and may be separated and worked up in an conventional manner.
[0041] Thus, in another aspect, the invention relates to a process as defined above which further comprises the step of O-alkylation of an enantiomerically enriched compound of formula (II) to yield the desired enantiomer of the pharmaceutically active Cizolirtine (I). To this end, the compound of formula (II) is treated with an amine of the formula
X—CH 2 CH 2 N(Me) 2
wherein X is a suitable leaving group such as halogen, more preferably chlorine, bromine or iodine; a reactive esterified hydroxyl, for example arylsulfonyloxy such as phenylsulfonyloxy; tosyloxy; mesyloxy; C 1-4 alkyl sulfonyloxy, for example methanesulfonyloxy; arylphosphoryloxy, for example diphenylphosphoryloxy, dibenzylphosphoryloxy or a C 1-4 alkyl phosphoryloxy, for example dimethylphosphoryloxy.
[0042] An appropriate O-alkylation has been described in EP289 380 and in International Patent Publication WO 99/07684, the disclosures of which hereby are incorporated herein in their entirety.
[0043] The alkylation preferably is carried out directly in the same reaction medium resulting from the process of the invention, without further purification of the carbinol. Alternatively the solvent can be evaporated and a non-polar solvent such as toluene added for the alkylation.
[0044] In general, the O-alkylation is carried out in conditions of phase transfer, using for example 2-chloro-N,N,-dimethylethylamine (other leaving groups instead of chloro are possible), an alkaline aqueous solution such as NaOH or KOH, in the presence of a catalyst such as a quaternary ammonium salt. Accordingly, the same solvent as the one used in the process of the invention is used, such as toluene. In these conditions we have the further advantage that the impurities, e.g., any remaining zinc salts, are also eliminated through the aqueous phase.
[0045] The resulting product of formula I is enantiomerically enriched, and it can be further purified using polar organic solvents. Further, a pharmaceutically acceptable salt of the compound of formula I can be formed. For example, the citrate salt can be prepared by dissolving the amine of formula I in ethanol and treating the solution with citric acid monohydrate. The preparation of other salts will be readily apparent to the person skilled in the art.
[0046] The following examples will further illustrate the invention, and are not to be interpreted as limiting, as regards the scope of the invention.
EXAMPLES
[0000] General Methods and Materials.
[0047] a) Reactions in Autoclave
[0048] The substrate, and the components of the chiral ruthenium (II) catalyst system used in the process of the present invention, bidentate phosphorous-containing ligand, amine and base (if the base is a solid) are weighed (it is not necessary that anaerobic conditions be used in such step) in a Schlenk flask. With larger quantities of substrate (more than 1.5 mmol), the substrate is filled directly into the autoclave. The Schlenk flask is securated and the solvent (stock solution) is added under anaerobic conditions. The formed suspension is stirred until the dissolution of the chiral ruthenium (II) catalyst system has been completed (˜5 min). Then the base solution is added with a securated Hamilton glass syringe and stirred again for 5 minutes if it was not already added as a solid at the beginning. Afterwards the solution is transferred into the securated autoclave standing under vacuum (via capillary and argon pressure). The reaction solution is then heated to the desired temperature. The desired hydrogen pressure is adjusted.
[0049] b) Reactions at Normal Pressure
[0050] The substrate, and the components of the chiral ruthenium (II) catalyst system used in the process of the present invention, bidentate phosphorous-containing ligand, amine and base (if the base is a solid) are weighed (it is not necessary to use anaerobic conditions for such step) and provided in an adjustable temperature two neck reaction vessel. This is connected to a dropping funnel containing the solvent (stock solution, under anaerobic conditions) and the normal pressure registration equipment. Afterwards this complete system is carefully securated. The solution in the dropping funnel is added to the solids in the reaction vessel and the base solution is added to the suspension. Then the argon is replaced with hydrogen (3× securation with hydrogen). Normal pressure is adjusted by deflating the overpressure over a bubble counter and the measurement is started.
Example 1
Preparation of the Enantiomerically Enriched phenyl 1-methylpirazoyl carbinol
[0051] TABLE 1 Preparation of the enantiomerically enriched phenyl 1-methylpirazoyl carbinol (variation of standard condition*) pressure time enantiomeric entry s/c Diamine solvent temperature (conversion) excess 1 50 R,R-DPEN 20 ml MeOH 100 bar 2 h 42 ee % 30° C. (100%) 2 50 R,R-DPEN 20 ml MeOH 100 bar 18 h 53 ee % 25° C. (100%) 3 100 R,R-DPEN 20 ml isopropanol 8 bar 3.5 h 73 ee % 35° C. (100%) 4 100 R,R-DPEN 20 ml isopropanol 8 bar 2 h 79 ee % 30° C. (100%) 5 100 R,R-DPEN 20 ml isopropanol 8 bar 5 h 81 ee % 25° C. (100%) 6 100 R,R-DPEN 20 ml 8 bar 3.5 h 82 ee % t-butanol 30° C. (100%) 7 100 R,R-DPEN 19 ml t-butanol 8 bar 1 h 80 ee % 1 ml isopropanol 30° C. (100%) 8 100 R-DAIPEN 20 ml isopropanol 8 bar 3 h 73 ee % 25° C. (100%) 9 100 ethylen- 20 ml isopropanol 8 bar 4 h 33 ee % diamine 25° C. (100%) 10 100 R,R-DPEN 20 ml isopropanol 1 bar 20 h 75 ee % 25° C. (98%) 11 100 R,R-DPEN 19 ml t-butanol 1 bar 20 h 75 ee % 1 ml isopropanol 25° C. (100%) *Standard conditions: 0.01 mmol R,R-Ru(BINAP); 0.01 mol amine; 0.5 or 1 mmol 1-methylpirazoyl carbinol; 0.04 mmol t-BuOK; 20 ml solvent; 1-100 bar H 2 ; 10-45° C.
Entry 1 and 2
according to method a)
[0052] The compound was prepared from 0.5 mmol phenyl 1-methylpyrazoyl ketone
[0000] 0.01 mmol R—Ru(BINAP); 0.01 mmol R,R-DPEN
[0000] 0.04 mmol t-BuOK (40 μl, t-BuOK 1.0 M solution in t-BuOH);
[0000] 20 ml methanol,
[0000] at 25° C. or 30° C. and 100 bar H 2 .
[0000] Conversion:
[0053] 100% after 2 hr with 42% ee for 30° C. and
[0054] 100% after 18 hr with 53% ee for 25° C.
[0000] Entry 3, 4 and 5
[0000] according to method a)
[0055] The compound was prepared from 1 mmol phenyl 1-methylpyrazoyl ketone
[0000] 0.01 mmol R—Ru(BINAP); 0.01 mmol R,R-DPEN
[0000] 0.04 mmol t-BuOK (40 μl, t-BuOK 1.0 M solution in t-BuOH);
[0000] 20 ml isopropanol,
[0000] at 25° C., 30° C. or 35° C. and 8 bar H 2 .
[0000] Conversion:
[0056] 100% after 3.5 hr with 73% ee for 35° C.,
[0057] 100% after 2 hr with 79% ee for 30° C. and
[0058] 100% after 5 hr with 81% ee for 25° C.
[0000] Entry 6 and 7
[0000] according to method a)
[0059] The compound was prepared from 1 mmol phenyl 1-methylpyrazoyl ketone
[0000] 0.01 mmol R—Ru(BINAP); 0.01 mmol R,R-DPEN
[0000] 0.04 mmol t-BuOK (40 μl, t-BuOK 1.0 M solution in t-BuOH);
[0000] 20 ml t-butanol or 19 ml t-butanol and 1 ml isopropanol;
[0000] at 30° C. and 8 bar H 2 .
[0000] Conversion:
[0060] 100% after 3.5 hr with 82% ee for 20 ml t-butanol and
[0061] 100% after 1 hr with 80% ee for 19 ml t-butanol and 1 ml isopropanol.
[0000] Entry 8 and 9
[0000] according to method a)
[0062] The compound was prepared from 1 mmol phenyl 1-methylpyrazoyl ketone
[0000] 0.01 mmol R—Ru(BINAP); 0.01 mmol R-DAIPEN or ethylendiamine;
[0000] 0.04 mmol t-BuOK (40 μl, t-BuOK 1.0 M solution in t-BuOH);
[0000] 20 ml isopropanol;
[0000] at 25° C. and 8 bar H 2 .
[0000] Conversion:
[0063] 100% after 3 hr with 73% ee for DAIPEN and
[0064] 100% after 4 hr with 33% ee for ethylendiamine.
[0000] Entry 10 and 11
[0000] according to method b)
[0065] The compound was prepared from 1 mmol phenyl 1-methylpyrazoyl ketone
[0000] 0.01 mmol R—Ru(BINAP); 0.01 mmol R,R-DPEN
[0000] 0.04 mmol t-BuOK (40 μl, t-BuOK 1.0 M solution in t-BuOH);
[0000] 20 ml isopropanol or 19 ml t-butanol and 1 ml isopropanol;
[0000] at 25° C. and 1 bar H 2 .
[0000] Conversion:
[0066] 98% after 20 hr with 75% ee for 20 ml isopropanol and
[0067] 100% after 20 hr with 75% ee for 19 ml t-butanol and 1 ml isopropanol.
[0068] The best results were obtained with the 19 to 1 mixture of t-butanol and isopropanol at 8 bar and 30° C., see example 7. | A process is described for the preparation of a precursor alcohol of Cizolirtine, (±)-2-[phenyl(1-methyl-1H-pyrazol-5-yl)methoxy]-N,N-dimethylethanamine and its enantiomers. The process involves the asymmetric reduction of a prochiral ketone in the presence of a chiral ruthenium (II) catalyst system including at least a bidentate phosphorous-containing ligand and a diamine ligand to yield chiral alcohols. The chiral alcohols are further O-alkylated to yield corresponding pharmaceutically active ethanamines. | 2 |
FIELD OF THE INVENTION
[0001] The invention relates to a novel process, novel process steps and novel intermediates useful in the synthesis of pharmaceutically active compounds, in particular neutral endopeptidase (NEP) inhibitors.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a method to prepare N-acyl derivatives of biphenyl alanine. N-acyl derivatives of biphenyl alanine are key intermediates in the synthesis of pharmaceutically active compounds, in particular neutral endopeptidase (NEP) inhibitors, such as those described in U.S. Pat. No. 4,722,810, U.S. Pat. No. 5,223,516, U.S. Pat. No. 4,610,816, U.S. Pat. No. 4,929,641, South African Patent Application 84/0670, UK 69578, U.S. Pat. No. 5,217,996, EP 00342850, GB 02218983, WO 92/14706, EP 0034391 1, JP 06234754, EP 00361365, WO 90/09374, JP 07157459, WO 94/15908, U.S. Pat. No. 5,273,990, U.S. Pat. No. 5,294,632, U.S. Pat. No. 5,250,522, EP 00636621, WO 93/09101, EP 00590442, WO 93/10773, WO2008/031567 and U.S. Pat. No. 5,217,996.
[0003] Typically, synthetic methods to prepare biphenyl alanine derivatives use expensive starting materials such as non-natural D-tyrosine. Moreover, said methods require the use of trifluoromethanesulfonic anhydride, which is also expensive, to activate the phenolic hydroxyl in order to carry out the aryl coupling reaction leading to the desired biphenyl structure. One example of such a synthetic approach is described in the Journal of Medicinal Chemistry 1995, Vol. 38 No. 10. Scheme 1 illustrates one of these methods:
[0000]
[0004] Therefore, there is a strong need to develop inexpensive methods to prepare biphenyl alanine derivatives. It is found that the present invention meets this objective and thus provides a process that is industrially advantageous.
SUMMARY OF THE INVENTION
[0005] This invention provides a method for preparing a N-acylbiphenyl alanine of formula (3), as defined herein. The new process, according to the present invention, for producing compounds according to formula (3), is summarized in Scheme 2. By reacting biphenyl formaldehyde, as defined herein, N-acylglycine (A), as defined herein, and an anhydride (B), as defined herein, under alkaline conditions, a compound of formula (1), as defined herein, is obtained. Said compound of formula (1) is next converted into a compound of formula (2), as defined herein, which in turn is hydrogenated, for example with hydrogen and palladium on charcoal, to provide the compound of formula (3). A compound of formula (3) can be converted into a neutral endopeptidase (NEP) inhibitors, for example, as described in the Journal of Medicinal Chemistry, 1995, Vol. 38, No. 10, 1691, and the patent documents cited hereinbefore, the disclosure for each of which is incorporated by reference
[0006] The synthetic process summarized in Scheme 2 uses inexpensive starting materials and reagents and is thus suitable for industrial production.
[0000]
DETAILED DESCRIPTION OF THE INVENTION
Step a
[0007] In a first embodiment the present invention relates to a method for preparing a compound of formula (1-a), or salt thereof,
[0000]
[0000] preferably wherein the compound of formula (1-a) is of the formula (1),
[0000]
[0000] wherein R1 is C 1-7 alkyl, preferably methyl, or C 6-10 aryl, preferably phenyl,
comprising
reacting
[0000]
[0000] or salt thereof,
with
a compound of formula (A),
[0000]
[0000] or salt thereof,
wherein R1 is as defined for the compound of formula (1-a),
and (R2CO) 2 O, wherein R2 is C 1-2 alkyl, preferably methyl or propyl, most preferably methyl or ethyl,
under alkaline conditions,
to provide the compound of formula (1-a).
[0008] The reactions described above can be carried out in solvents generally known in the art, for example, in the presence of a solvent, (named solvent I), selected from benzene, toluene, xylene, chlorobenzene, dichlorobenzene, nitrobenzene, heptane, acetic acid, propionic acid, isobutyric acid, n-butyric acid, acetic anhydride or propionic anhydride.
[0009] Preferably, anhydride (B) is acetic anhydride or propionic anhydride.
[0010] The term “under alkaline conditions” means that the step requires a base. Preferably, said base is selected from triethylamine, pyridine, N-methylpyrrole, N-methylmorpholine, sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, sodium acetate, potassium acetate, sodium propionate, or potassium propionate.
[0011] Preferably, step a is carried out at a reaction temperature of from 80 deg C. to reflux, preferably, with a reaction time of 0.5 to 48 hours.
[0012] Preferably, in step a, the molar ratio of said biphenyl formaldehyde:said N-acylglycine (A):said anhydride (B):said base is 1.0:(0.7 to 5.0):(1.0 to 6.0):(0.05 to 2.00); the amount of said solvent I is 0 to 20 times the weight of feed amount of said biphenyl formaldehyde.
Step b
[0013] In a further embodiment, the present invention relates to a method for preparing a compound of formula (2-a), or salt thereof,
[0000]
[0000] preferably wherein the compound of formula (2-a) is of the formula (2),
[0000]
[0000] wherein R1 is C 1-7 alkyl, preferably methyl, or C 6-10 aryl, preferably phenyl,
comprising
reacting
a compound of formula (1-a), or salt thereof,
[0000]
[0000] preferably wherein the compound of formula (1-a) is of the formula (1),
[0000]
[0000] wherein R1 is as defined for a compound of formula (2-a),
with water
to provide the compound of formula (2-a).
[0014] The reactions described above can be carried out in solvents generally known in the art, for example, in the presence of a solvent, (named solvent II), selected from water, ethanol, methanol, isopropanol, propanol, ethyl acetate, isopropyl acetate, ethyl propionate, acetone, butanone, methyl isobutyl ketone, tetrahydrofuran, 1,4-dioxane, N, N-dimethyl formamide, or N-methylpyrrole. Preferably, the weight of feed amount of said solvent II is 2 to 50 times the amount of the compound of formula (1) [named product 1] in step a; the weight of feed amount of water is 0.5 to 20 times the amount of product 1 in step a.
[0015] Preferably, step b is carried out at a reaction temperature of from room temperature to reflux.
Step c
[0016] In a further embodiment, the present invention relates to a method for preparing a compound of formula (3), or salt thereof,
[0000]
[0000] preferably wherein the compound of formula (3) is of the formula (3-a),
[0000]
[0000] wherein R1 is C 1-7 alkyl, preferably methyl, or C 6-10 aryl, preferably phenyl,
comprising
treating a compound of formula (2-a), or salt thereof,
[0000]
[0000] preferably wherein the compound of formula (2-a) is of the formula (2),
[0000]
[0000] wherein R1 is C 1-7 alkyl, preferably methyl, or C 6-10 aryl, preferably phenyl,
under hydrogenation conditions
to provide the compound of formula (3).
[0017] Hydrogenation conditions are well-known in the art and thus refer to the use of hydrogen and a transition metal catalyst, for example, as described in Section B.3.3 in WO2009/090251, which is incorporated herein by reference. Preferably the transition metal catalyst is palladium, preferably palladium on charcoal, preferably containing 1% to 20% palladium by weight.
[0018] In another embodiment, the hydrogenation takes place with hydrogen in the presence of a transition metal catalyst comprising an organometallic complex and a chiral ligand, for example as described in Section C.2 in WO2009/090251, which is incorporated herein by reference.
[0019] The reactions described above can be carried out in solvents generally known in the art, for example, in the presence of a solvent (named solvent III) selected from ethanol, methanol, ethyl acetate, N, N-dimethyl formamide, N-methylpyrrole and tetrahydrofuran.
[0020] Preferably, in step c, the weight of feed amount of said solvent III is 5 to 50 times of the amount of the compound of formula (1) [named product 1] in step a. Preferably, the amount of palladium on charcoal is 0.1% to 20% of the compound of formula (2) [named product 2] in step b by weight.
[0021] Preferably, in step c, glacial acetic acid is also added in order to maintain acidic conditions.
[0022] Preferably, the reaction temperature is of from 20 deg C. to 150 deg C.
[0023] Preferably, the pressure of hydrogen is 0.2 MPa to 10.0 MPa.
Further Embodiments
[0024] In a further aspect, the present invention relates to a method for preparing a compound of formula (3), as defined herein, or salt thereof, comprising
i) step a), as described above; ii) step b), as described above; and iii) step c) as described above.
[0028] In a still further aspect, the present invention relates to a method for preparing a compound of formula (3), as defined herein, or salt thereof, comprising
iv) step b), as described above; and v) step c) as described above.
Preferred Embodiments
Embodiment [1]
[0031] A method for preparing N-acylbiphenyl alanine which is characterized by the following steps:
[0000]
[0032] Wherein R1 is a straight-chain or branched-chain alkyl or aryl and R2 is a methyl or ethyl.
Embodiment [2]
[0033] A method for preparing N-acylbiphenyl alanine according to embodiment [1], characterized in that for step a, the molar ratio of said biphenyl formaldehyde:said N-acylglycine:said anhydride:said base is 1.0:(0.7 to 5.0):(1.0 to 6.0):(0.05 to 2.00), and the amount of said solvent I is 0 to 20 times the weight of feed amount of said biphenyl formaldehyde.
Embodiment [3]
[0034] A method for preparing N-acylbiphenyl alanine according to embodiment [1], characterized in that for step a, said solvent I is selected from benzene, toluene, xylene, chlorobenzene, dichlorobenzene, nitrobenzene, heptane, acetic acid, propionic acid, isobutyric acid, n-butyric acid, acetic anhydride, or propionic anhydride; said anhydride is acetic anhydride or propionic anhydride; said base is selected from triethylamine, pyridine, N-methylpyrrole, N-methylmorpholine, sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, sodium acetate, potassium acetate, sodium propionate, or potassium propionate.
Embodiment [4]
[0035] A method for preparing N-acylbiphenyl alanine according to embodiment [1], characterized in that step a is carried out at a reaction temperature from 80 deg C. to reflux with a reaction time of 0.5 to 48 hours.
Embodiment [5]
[0036] A method for preparing N-acylbiphenyl alanine according to embodiment [1], characterized in that for step b, said solvent II is selected from water, ethanol, methanol, isopropanol, propanol, ethyl acetate, isopropyl acetate, ethyl propionate, acetone, butanone, methyl isobutyl ketone, tetrahydrofuran, 1,4-dioxane, N, N-dimethyl formamide, or N-methylpyrrole.
Embodiment [6]
[0037] A method for preparing N-acylbiphenyl alanine according to embodiment [1], characterized in that for step b, the weight of feed amount of said solvent II is 2 to 50 times the amount of product 1 in step a; the feed amount of said water is 0.5 to 20 times the amount of product 1 in step a.
Embodiment [7]
[0038] A method for preparing N-acylbiphenyl alanine according to embodiment [1], characterized in that step b is carried out at a reaction temperature from room temperature to reflux.
Embodiment [8]
[0039] A method for preparing N-acylbiphenyl alanine according to embodiment [1], characterized in that for step c, the said solvent III is selected from ethanol, methanol, ethyl acetate, N, N-dimethyl formamide, N-methylpyrrole, or tetrahydrofuran; and said palladium charcoal contains 1% to 20% palladium by weight.
Embodiment [9]
[0040] A method for preparing N-acylbiphenyl alanine according to embodiment [1], characterized in that for step c, wherein the weight of feed amount of said solvent III is 5 to 50 times the amount of product 1 in step a, the amount of said palladium charcoal is 0.1% to 20% of the product 2 in step b by weight.
Embodiment [10]
[0041] A method for preparing N-acylbiphenyl alanine according embodiment [1], characterized in that glacial acetic acid is also added in order to adjust pH and maintain acidic conditions while step c is carried out, and the range of reaction temperature is from 20 deg C to 150 deg C, and said pressure of hydrogen is 0.2 MPa to 10.0 MPa.
GENERAL TERMS
[0042] Listed below are definitions of various terms used to describe the present invention. These definitions, either by replacing one, more than one or all general expressions or symbols used in the present disclosure and thus yielding preferred embodiments of the invention, preferably apply to the terms as they are used throughout the specification unless they are otherwise limited in specific instances either individually or as part of a larger group.
[0043] Alkyl being a radical or part of a radical is a straight or branched (one or, if desired and possible, more times) carbon chain, and is especially C 1 -C 7 -alkyl, such as C 1 -C 4 -alkyl, in particular branched C 1 -C 4 -alkyl, such as isopropyl. The term “lower” or “C 1 -C 7 -” defines a moiety with up to and including maximally 7, especially up to and including maximally 4, carbon atoms, said moiety being branched (one or more times) or straight-chained and bound via a terminal or a non-terminal carbon. Lower or C 1 -C 7 -alkyl, for example, is n-pentyl, n-hexyl or n-heptyl or preferably C 1 -C 4 -alkyl, especially as methyl, ethyl, n-propyl, sec-propyl, n-butyl, isobutyl, sec-butyl, tert-butyl, in particular methyl, ethyl, n-propyl, iso-propyl, n-butyl, isobutyl, sec-butyl, tert-butyl. Very preferred is methyl or ethyl.
[0044] Aryl, as a radical or part of a radical, for example is a mono- or bicyclic aryl with 6 to 22 carbon atoms, such as phenyl, indenyl, indanyl or naphthyl, in particular phenyl.
[0045] In formulae above and below, the term “ ” represents a covalent bond, which comprises an (E) stereoisomer as well as a (Z) stereoisomer.
[0046] The term “reflux” refers to the temperature at which the reaction mixture boils, preferably a temperature up to 180° C., preferably up to 140° C.
[0047] As used herein, the term “room temperature” or “ambient temperature” means a temperature of from 20 to 35° C., such as of from 20 to 25° C.
[0048] The terms “transition metal catalyst”, “organometallic complex” and “chiral ligand” are as described in WO2009/090251, and said definitions are incorporated herein by reference.
[0049] In the formulae of the present application the term “Ph” means phenyl.
[0050] In view of the close relationship between the compounds and intermediates in free form and in the form of their salts, including those salts that can be used as intermediates, for example in the purification or identification of the compounds or salts thereof, any reference to “compounds”, “starting materials” and “intermediates” hereinbefore and hereinafter, is to be understood as referring also to one or more salts thereof or a mixture of a corresponding free compound, intermediate or starting material and one or more salts thereof, each of which is intended to include also any solvate, metabolic precursor such as ester or amide, or salt of any one or more of these, as appropriate and expedient and if not explicitly mentioned otherwise. Different crystal forms may be obtainable and then are also included. Salts can be formed where salt forming groups, such as basic or acidic groups, are present that can exist in dissociated form at least partially, e.g. in a pH range from 4 to 10 in aqueous solutions, or can be isolated especially in solid, especially crystalline, form. In the presence of basic groups (e.g. imino or amino), salts may be formed preferably with organic or inorganic acids. Suitable inorganic acids are, for example, halogen acids, such as hydrochloric acid, sulfuric acid, or phosphoric acid. Suitable organic acids are, for example, carboxylic, phosphonic, sulfonic or sulfamic acids, for example acetic acid, propionic acid, lactic acid, fumaric acid, succinic acid, citric acid, amino acids, such as glutamic acid or aspartic acid, maleic acid, hydroxymaleic acid, methylmaleic acid, benzoic acid, methane- or ethane-sulfonic acid, ethane-1,2-disulfonic acid, benzenesulfonic acid, 2-naphthalenesulfonic acid, 1,5-naphthalene-disulfonic acid, N-cyclohexylsulfamic acid, N-methyl-, N-ethyl- or N-propyl-sulfamic acid, or other organic protonic acids, such as ascorbic acid. In the presence of negatively charged radicals, such as carboxy or sulfo, salts may be formed with bases, e.g. metal or ammonium salts, such as alkali metal or alkaline earth metal salts, for example sodium, potassium, magnesium or calcium salts, or ammonium salts with ammonia or suitable organic amines, such as tertiary monoamines, for example triethylamine or tri(2-hydroxyethyl)amine, or heterocyclic bases, for example N-ethyl-piperidine or N,N′-dimethylpiperazine. When a basic group and an acid group are present in the same molecule, internal salts may also be formed. Particularly useful salts include the hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric, lactic acid, fumaric acid, succinic acid, oxalic acid, malic acid, malonic acid, tartaric acid, tolyltartaric acid, benzoyltartaric acid, orotic acid, nicotinic acid, methane-sulfonic acid or 4-methylbenzenesulfonic acid salts of compounds of formula (1), (1-a), (2), (2-a), (3), (3-a) and the like formed from reaction with the above reagents. Methods to prepare acid addition salts are described in the literature, for example, in the relevant chapters of “CRC Handbook of Optical Resolutions via Diasteromeric Salt Formation”, D. Kozma, CRC Press 2002, in Acta Cryst, 2006, B62, 498-505 and in Synthesis, 2003, 13, 1965-1967.
[0051] Where the plural form is used for compounds, starting materials, intermediates, salts, pharmaceutical preparations, diseases, disorders and the like, this is intended to mean one (preferred) or more single compound(s), salt(s), pharmaceutical preparation(s), disease(s), disorder(s) or the like, where the singular or the indefinite article (“a”, “an”) is used, this is not intended to exclude the plural, but only preferably means “one”.
[0052] Particular embodiments of the invention are provided in the following Examples. These Examples serve to illustrate the invention without limiting the scope thereof, while they on the other hand represent preferred embodiments of the reaction steps, intermediates and/or the process of the present invention.
Example 1
[0053] Synthesis of 4-(4-biphenyl methylene)-2-methyl-oxazole-5 (4H)-ketone (1, R1=Me)
[0000]
[0054] In a dry and clean reaction bottle, add 36.4 g of biphenyl formaldehyde (Japan, Mitsubishi Chemical Co, Ltd, industrial, contents >98%), 28 g of acetyl glycine, 56 g of acetic anhydride, and 6 g of anhydrous sodium acetate. Heat to reflux for 0.5 hours. End heat preservation and cool to 80 deg C. Add 200 ml of water and agitate for 30 min. Filtrate and use 100 ml of water to wash filter cake for two times. Vacuum dry wet product at 30 to 40 deg C to obtain the title product.
[0055] 1H NMR (400 MHz, CDCl 3 ) δ 8.16 (d, J=8.4 Hz, 2H), 7.74-7.66 (m, 2H), 7.66-7.58 (m, 2H), 7.52-7.43 (m, 2H), 7.43-7.36 (m, 1H), 7.19 (s, 1H), 2.43 (s, 3H). M=263.
Example 2
Synthesis of 2-acetamido-3-biphenyl propenoic acid (2, R1=Me)
[0056]
[0057] In a 1000 ml reaction bottle, add 40 g of 4-(4-biphenyl methylene)-2-methyl-oxazole-5 (4H)-ketone (1, R1=Me), 450 ml of acetone, and 60 ml of tap water. Heat to reflux for 8 hours. End heat preservation. Add 3 g activated charcoal and decolorate for 1 hour. Filtrate and wash with 50 ml of acetone. Steam distillate acetone about 300 ml and then add 200 ml of water. Cool down to 20 deg C. Filtrate and dry wet product at 60 deg C to obtain the title product. 1H NMR (400 MHz, DMSO) δ 12.69 (s, 1H), 9.53 (s, 1H), 7.81-7.64 (m, 6H), 7.49 (dd, J=10.4, 4.7 Hz, 2H), 7.39 (dd, J=8.2, 6.5 Hz, 1H), 7.26 (s, 1H), 2.01 (s, 3H). M=281, M+=280.
Example 3
Synthesis of 3-biphenyl-2-acetamido alanine acid (3, R1=Me)
[0058]
[0059] In a 1 L high-pressure autoclave, add 20 g of 2-acetamido 3-biphenyl propenoic acid (2, R1=Me), 300 ml of anhydrous ethanol, 2 ml of glacial acetic acid, and 1 g of palladium charcoal containing 5% of palladium. Seal the reaction autoclave and use nitrogen to displace air. Heat to 70 to 80 deg C of internal temperature. Adjust hydrogen pressure to 6 MPa. React for 20 hours with heat preservation. Cool down reaction autoclave to 60 deg C. Release gas. Filtrate it. Wash with 10 ml of ethanol. Condense the filtrate to about 60 ml. Cool down to 0 to 5 deg C. Filtrate and dry wet product at 60 deg C to obtain the title product.
[0060] 1H NMR (500 MHz, DMSO-d6): 1.82, 2.89-2.93, 3.08-3.12, 4.45-4.50, 7.33-7.37, 7.44-7.47, 7.58-7.60, 7.64-7.66, 8.26-8.28, 12.75; MS (m/z): 224.07(100), 167.14(56), 165.16(26), 282.94 ([MH+], 1).
Example 4
Synthesis of 4-(4-biphenyl methylene)-2-phenyl-oxazole-5(4H)-ketone (1, R1=Ph)
[0061]
[0062] In a dry and clean reaction bottle, add 36.4 g of biphenyl formaldehyde (Japan, Mitsubishi Chemical Co, Ltd, industrial, contents >98%), 33 g of N-benzoyl glycine, 52 g of propionic anhydride, and 20 g of N-methylmorpholine and 182 g of chlorobenzene. Heat to 100 deg C. Heat preserve for 24 hours. Cool down to 80 deg C. Add 200 ml of water and agitate for 30 min. Filtrate and use 100 ml of water to wash filter cake for two times. Vacuum dry wet product to obtain the title product.
[0063] 1H NMR (400 MHz, CDCl3) δ 8.29 (d, J=8.4 Hz, 2H), 8.24-8.17 (m, 2H), 7.73 (d, J=8.4 Hz, 2H), 7.69-7.59 (m, 3H), 7.55 (t, J=7.5 Hz, 2H), 7.49 (dd, J=10.2, 4.8 Hz, 2H), 7.44-7.37 (m, 1H), 7.29 (s, 1H). M=325.
Example 5
Synthesis of 2-benzamido-3-biphenyl propenoic acid (2, R1=Ph)
[0064]
[0065] In a 1000 ml reaction bottle, add 60 g of 4-(4-biphenyl methylene)-2-phenyl-oxazole-5 (4H)-ketone (1, R1=Ph), 1000 ml of tetrahydrofuran, and 150 ml of tap water. Heat to room temperature. Heat preserve for 24 hours. Add 3 g of activated charcoal and decolorate for 1 hour. Filtrate and wash with 50 ml of tetrahydrofuran. After steam distillating about 600 ml of tetrahydrofuran, cool down to 20 deg C. Filtrate and dry wet product at 60 deg C to obtain the title product.
[0066] 1H NMR (400 MHz, DMSO) δ 9.61 (s, 1H), 8.00 (t, J=8.6 Hz, 2H), 7.82-7.36 (m, 13H), 7.33 (t, J=7.2 Hz, 1H). M=343, M+=342.
Example 6
Synthesis of 3-biphenyl-2-benzamido alanine (3, R1=Ph)
[0067]
[0068] In a 1 L high-pressure autoclave, add 10 g of 2-benzamido 3-biphenyl propenoic acid (2, R1=Ph), 350 ml of methanol, 1 ml of glacial acetic acid, and 2 g of palladium charcoal (Pd/C) containing 5% of palladium. Seal the reaction autoclave and displace air with nitrogen. Heat to 140 to 150 deg C of internal temperature. Adjust nitrogen pressure to 0.2 MPa. React for 20 hours with heat preservation. Cool down reaction autoclave to 60 deg C. Release gas. Filtrate and wash with about 10 ml of ethanol. Condense filtrate to about 60 ml. Cool down to 0 to 5 deg C. Filtrate and dry wet product at 60 deg C to obtain the title product.
[0000] 1H NMR (500 MHz, DMSO-d6): 3.12-3.17, 3.23-3.27, 4.65-4.70, 7.31-7.33, 7.34-7.45, 7.46-7.48, 7.58-7.60, 7.62-7.64, 7.83-7.84, 8.77-8.79, 12.85; MS (m/z): 224.0(100), 167.1(34), 165.1(15), 105.1(10), 77.2(18), 344.8 ([MH+], 1).
Example 7
Synthesis of 4-(4-biphenyl methylene)-2-phenyl-oxazole-5(4H)-ketone (1, R1=Ph)
[0069]
[0070] In a dry and clean reaction bottle, add 36.4 g of biphenyl formaldehyde (Japan, Mitsubishi Chemical Co, Ltd, industrial, contents >98%), 33 g of N-benzoyl glycine, 52 g of propionic anhydride, and 10 g of anhydrous sodium propionate and 200 g of dichlorobenzene. Heat to 80 deg C. Heat preserve for 48 hours. Cool down to 80 deg C. Add 200 ml of water and agitate for 30 min. Filtrate and use 100 ml of water to wash filter cake two times. Vacuum dry wet product at 30 to 40 deg C to obtain the title product.
[0071] Spectroscopic data as Example 4.
Example 8
Synthesis of 2-benzamido-3-biphenyl propenoic acid (2, R1=Ph)
[0072]
[0073] In a 1000 ml reaction bottle, add 50 g of 4-(4-biphenyl methylene)-2-phenyl-oxazole-5 (4H)-ketone (1, R1=Ph), 550 ml of butanone, and 120 ml of tap water. Heat to 40 deg C. Heat preservation for 24 hours. Add 3 g of activated charcoal and decolorate for 1 hour. Filtrate and wash with 50 ml of tetrahydrofuran. After steam distillating about 600 ml of tetrahydrofuran cool down to 20 deg C. Filtrate and dry wet product at 60 deg C to obtain the title product.
[0074] Spectroscopic data as Example 5.
Example 9
Synthesis of 3-biphenyl-2-benzamido alanine (3, R1=Ph)
[0075]
[0076] In a 1 L high-pressure autoclave, add 15 g of 2-benzamido 3-biphenyl propenoic acid (2, R1=Ph), 300 ml of tetrahydrofuran, 1.5 ml of glacial acetic acid, and 4 g of palladium charcoal (Pd/C) containing 5% of palladium. Seal the reaction autoclave and displace air with nitrogen. Heat to 100 to 110 deg C of internal temperature. Adjust hydrogen pressure to 10.0 MPa. React for 20 hours with heat preservation. Cool down reaction autoclave to 60 deg C. Release gas. Filtrate and wash with about 10 ml of ethanol. Condense filtrate to about 60 ml. Cool down to 0 to 5 deg C. Filtrate and dry wet product at 60 deg C to obtain the title product.
[0077] Spectroscopic data as Example 6. | The invention relates to a novel process, novel process steps and novel intermediates useful in the synthesis of pharmaceutically active compounds, in particular neutral endopeptidase (NEP) inhibitors. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 61/815,079 filed Apr. 23, 2013. The disclosure of the above application is incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates generally to an integrated valve assembly which is capable of providing venting from a carbon canister, as well as providing venting from the fuel EVAP system during on-board diagnostic testing.
BACKGROUND OF THE INVENTION
Purge systems are generally known and are used in different types of vehicles. Some types of turbo purge systems in vehicles equipped with turbocharging units use two check valves located remotely from a turbo purge valve to control turbo pressure and intake vacuum respectively to supply a source vacuum to a canister purge valve. The pressurized air generated by the turbocharger is forced into the engine to increase combustion pressure, and therefore increase the power generated by the engine. With some tubocharging systems, a portion of the pressurized air is bled off to create a vacuum and induce flow of purge vapor. The vacuum created is used as part of a purge system, where the purge system directs purge vapors from a fuel tank through various conduits to redirect the vapors into the intake manifold of the engine, and burn off these vapors through combustion.
The types of check valves used in these systems commonly check at very low vacuum pressure levels. Because these check valves check at such low vacuum pressure, it is difficult to use these valves to vent the fuel tank system and stabilize to atmospheric conditions prior to initiating the small leak test for on-board diagnostic (OBD) compliance.
To overcome this issue, these types of systems typically require a separate OBD relief valve to vent the fuel evaporative emissions (EVAP) system when the vehicle is shut off. The valve is necessary to conduct the OBD test. However, the inclusion of this valve adds complexity and cost to the system.
Accordingly, there exists a need for a valve assembly which is able to vent the fuel tank system, and allow the fuel tank system to stabilize to atmospheric conditions, as well as perform an OBD test, and control turbo pressure and intake vacuum pressure supplied to a turbo purge valve.
SUMMARY OF THE INVENTION
The present invention is an integrated valve assembly, which integrates two check valves and a purge valve. Each check valve utilizes a nylon insert along with an over molded rubber seal. The added mass and design of the check valves prevents actuation at low vacuums and flows when the vehicle is shut off.
To further accelerate EVAP system bleed down, drive software pulses the purge valve to create a pressure differential across the purge valve, and the resulting pressure pulses provide momentum to the check valves because of the increased mass and design of the check valves, which prevents checking.
The integrated valve assembly of the present invention eliminates the need for an OBD relief valve, and simplifies the EVAP system, saving costs, complexity, and eliminates several possible leak connections.
In one embodiment, the present invention is a turbo purge valve assembly which includes an overmold assembly having an overmold assembly cavity, a solenoid assembly located in the overmold assembly adjacent the overmold assembly cavity, a cap connected to the overmold assembly, a reservoir connected to the cap, and a reservoir cavity formed as part of the reservoir. A cap aperture is formed as part of the cap, such that the cap aperture provides fluid communication between the overmold assembly cavity and the reservoir cavity when the solenoid assembly is in an open position. The turbo purge valve assembly also includes a first check valve connected to the reservoir and in fluid communication with an intake manifold and the reservoir cavity, and a second check valve connected to the reservoir and in fluid communication with a venturi valve member and the reservoir cavity.
During a first mode of operation and when the solenoid assembly is in an open position, vacuum pressure places the first check valve in an open position and the second check valve in a closed position. During a second mode of operation and when the solenoid assembly is in an open position, pressurized air places the first check valve in a closed position, and vacuum pressure generated by the venturi valve member places the second check valve in an open position.
The first check valve includes a first valve plate moveable between an open position and a closed position, a first seal member connected to and circumscribing the first valve plate, and a first valve seat selectively in contact with the first seal member. A first check valve aperture is in fluid communication with the reservoir cavity, and the first check valve aperture is at least partially surrounded by the first valve seat. The first check valve also includes a first base portion, a first inner wall formed as part of the first base portion, and the first seal member is selectively in contact with the first inner wall. The first check valve also has a first plurality of vents formed as part of the first base portion, and a first check valve cavity, the first plurality of vents and the first check valve aperture are in fluid communication with the first check valve cavity. A first vent port is integrally formed with the first base portion, and a first guide member at least partially extends into the reservoir cavity and partially extends into the first vent port, and the first valve plate is integrally formed with the guide member.
The first valve plate is located in the first check valve cavity, and during the first mode of operation, the first valve plate is exposed to vacuum pressure from the intake manifold, which causes the first valve plate to move toward and contact the first inner wall, placing the first check valve is in the open position, allowing purge vapor to flow from the reservoir cavity through the first check valve aperture, through the first check valve cavity, and through the first plurality of vents and out of the first vent port. During the second mode of operation, pressurized air places the first valve plate in contact with the first valve seat, preventing purge vapor from entering the first check valve cavity from the reservoir cavity.
The second check valve is constructed similarly to the first check valve, and the second check valve includes a second valve plate moveable between an open position and a closed position, a second seal member connected to and circumscribing the second valve plate, and a second valve seat selectively in contact with the second seal member. A second check valve aperture is in fluid communication with the reservoir cavity, and the second check valve aperture surrounded by the second valve seat. The second check valve also includes a second base portion, a second inner wall formed as part of the second base portion, and the second seal member is selectively in contact with the second inner wall. The second check valve also includes a second plurality of vents formed as part of the second base portion, and a second check valve cavity, the second plurality of vents and the second check valve aperture are in fluid communication with the second check valve cavity. A second vent port is integrally formed with the base portion, and a second guide member at least partially extends into the reservoir cavity and partially extends into the second vent port, and the second valve plate integrally formed with the second guide member.
The second valve plate is located in the second check valve cavity, and during the first mode of operation, the second valve plate is exposed to vacuum pressure in the reservoir cavity, which places the second valve plate in contact with the second valve seat, preventing purge vapor from entering the second check valve cavity from the reservoir cavity. During the second mode of operation, the second valve plate is exposed to vacuum pressure from the venturi valve assembly, which moves the second valve plate toward and in contact with the second inner wall, placing the second check valve in the open position, allowing purge vapor to flow from the reservoir cavity through the second check valve aperture, through the second check valve cavity, and through the second plurality of vents and out of the second vent port.
In one embodiment, the turbo purge valve assembly of the present invention is used with an air flow system for a vehicle. The air flow system includes a turbocharger unit for generating the pressurized air such that a portion of the pressurized air flows into the first check valve of the turbo purge valve assembly during the second mode of operation. The air flow system also includes a canister containing purge vapor, which is in fluid communication with the turbo purge valve assembly. A pressure sensor is used for detecting a change in pressure in the canister. The turbo purge valve assembly is part of the air flow system, and performs an on-board diagnostic test for detecting a malfunction in the air flow system. During the on-board diagnostic test, the air flow system is in the second mode of operation, and the turbocharger unit is generating pressurized air, the solenoid assembly is placed in the closed position. If the system is functioning properly, there is no change in pressure in the canister when the solenoid assembly is changed to the closed position because the canister and the turbo purge valve assembly are sealed components. If the pressure sensor detects change in pressure in the canister, this is an indication of a malfunction, such as a leak, in the canister, the turbo purge valve assembly, or some other component, when a change of pressure occurs.
In one embodiment, the turbo purge valve assembly also includes a canister vacuum relief function, where the solenoid assembly is pulsated after the vehicle is shut off. The pulsation of the solenoid assembly generates an air pulsation in the reservoir cavity, opening one of the first check valve or the second check valve, allowing air to pass from either of the first vent port or the second vent port into the reservoir cavity, through the solenoid assembly, through the overmold assembly cavity, and into the canister to relieve vacuum pressure in the canister.
The turbo purge valve assembly also includes the features having the ability to reduce or eliminate turbo lag which occurs during the initial activation of the turbocharger unit. The first check valve is unbiased towards the open position or the closed position, and the second check valve is also unbiased towards the open position or closed position, allowing both the first check valve and the second check valve to transition between open and closed positions from the application of the pressurized air or vacuum pressure, reducing turbo lag as the turbocharger is activated and deactivated.
In other embodiments, the turbo purge valve assembly is oriented such that gravity biases the first check valve to the open position, or the turbo purge valve assembly is oriented such that gravity biases the first check valve to the closed position. In yet other alternate embodiments, the turbo purge valve assembly is oriented such that gravity biases the second check valve to the open position, or the turbo purge valve assembly is oriented such that gravity biases the second check valve to the closed position.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a diagram of an air flow system having a turbo purge valve assembly, according to embodiments of the present invention;
FIG. 2 is a perspective view of a turbo purge valve assembly, according to embodiments of the present invention;
FIG. 3 is a sectional side view of a turbo purge valve assembly, according to embodiments of the present invention; and
FIG. 4 is an exploded view of a turbo purge valve assembly, according to embodiments of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
A diagram of an airflow system of a vehicle having a turbo purge valve assembly according to the present invention is shown generally in FIG. 1 at 10 . The system 10 includes an air box 12 which intakes air from the atmosphere. Located downstream of and in fluid communication with the air box 12 is a turbocharger unit 14 , and located downstream of and in fluid communication with the turbocharger unit 14 is a throttle assembly 16 . The throttle assembly 16 controls the amount of air flow into an intake manifold 18 , which is part of an engine.
A plurality of conduits also provides fluid communication between the various components. Air flows through the conduits between the various components, and the direction of airflow through the conduits varies, depending on the mode of operation of each component. More specifically, there is a first conduit 20 a providing fluid communication between the air box 12 and the turbocharger 14 , a second conduit 20 b providing fluid communication between the turbocharger 14 and the throttle assembly 16 , and there is also a third conduit 20 c providing fluid communication between the throttle assembly 16 and the intake manifold 18 .
A fourth conduit 20 d is in fluid communication with the third conduit 20 c and a turbo purge valve assembly 22 , and a fifth conduit 20 e places the turbo purge valve assembly 22 in fluid communication with a venturi valve assembly 24 . The turbo purge valve assembly 22 includes a first check valve 60 in fluid communication with the fourth conduit 20 d , and a second check valve 62 in fluid communication with the fifth conduit 20 e . There is also a carbon canister 30 in fluid communication with the turbo purge valve assembly 22 through the use of a sixth conduit 20 f.
A seventh conduit 20 g provides fluid communication between the venturi valve assembly 24 and the second conduit 20 b , such that pressurized air is able to flow from the second conduit 20 b , through the seventh conduit 20 g and to the venturi valve assembly 24 . An eighth conduit 20 h provides fluid communication between the venturi valve assembly 24 and the air box 12 .
Referring to FIGS. 2-4 , the turbo purge valve assembly 22 includes an overmold assembly 36 , and disposed within the overmold assembly 36 is a solenoid assembly, shown generally at 68 , and the solenoid assembly 68 is disposed within a cavity, shown generally at 70 , formed as part of the overmold assembly 36 , and the cavity includes an inner wall portion 72 , and also forming part of the cavity 70 is an outer wall portion 74 of the overmold assembly 36 .
The solenoid assembly 68 includes a stator insert 38 which surrounds a support 78 formed as part of the overmold assembly 36 . A first washer 40 is disposed between an upper wall 80 of the overmold assembly 36 and a bobbin 42 . The bobbin 42 is surrounded by a coil 48 , and two straps 44 surround the coil 48 . There is a sleeve 46 which is surrounded by the bobbin 42 , and the sleeve 46 partially surrounds a moveable armature 54 . The armature 54 includes a cavity, shown generally at 82 , and located in the cavity 82 is a spring 52 , which is in contact with an inner surface 84 of the cavity 82 . The spring 52 is also mounted on a narrow diameter portion 86 of the support 78 . Disposed between part of the armature 54 and the bobbin 42 is a second washer 50 . Connected to the overmold assembly 36 is a cap 56 , and formed as part of the cap 56 is a valve seat 88 and a cap aperture 90 , where purge vapor is able to flow from an overmold assembly cavity, shown generally at 92 , formed as part of the overmold assembly 36 and through the cap aperture 90 .
The armature 54 includes a stopper portion 54 a which is made of a rubber or other flexible material. The stopper portion 54 a includes a contact surface 96 which contacts the valve seat 88 when the armature 54 is in the closed position. The stopper portion 54 a includes a plurality of post members 98 are of the same durometer, but are of different sizes, and therefore have different levels of stiffness. The largest post members 98 are in contact with the bottom surface of the washer 50 when the armature 54 is in the closed position, as shown in FIG. 3 . The smaller post members 98 contact the bottom surface of the washer 50 when the armature 54 moves to the open position. The more the coil 48 is energized, the further the armature 54 moves away from the valve seat 88 , and the greater number of post members 98 contact the bottom surface of the washer 50 . The movement of the armature 54 to open and close the solenoid assembly 68 controls the amount of purge vapor allows to pass through the turbo purge valve assembly 22 , and into the intake manifold 18 .
Because the post members 98 are made of rubber, the post members 98 are able to deform as the armature 54 is moved further away from the valve seat 88 . The largest post members 98 in contact with the bottom surface of the washer 50 deform first when the armature 54 moves away from the valve seat 88 . As the armature 54 moves further away from the valve seat 88 , more of the post members 98 contact the bottom surface of the washer 50 , and then begin to deform as the armature 54 moves even further away from the valve seat 88 . The deformation of the post members 98 (when the armature 54 is moved to the open position away from the valve seat 88 ) functions to dampen the movement of the armature 54 , eliminating noise, and preventing metal-to-metal contact between the armature 54 and the stator insert 38 .
Disposed between the bottom surface of the washer 50 and an inside surface 100 of the cap 56 is a filter 102 . The filter 102 is made of several blades of plastic which are adjacent one another. The filter 102 is designed to limit the size of debris and particles passing through the blades of plastic to less than 0.7 millimeters. The distance between the armature 54 and the stator insert 38 is about 1.0 millimeters, and is the maximum allowable distance between the contact surface 96 of the stopper portion 54 a and the valve seat 88 . The filter 102 ensures that no particles may pass through the filter 102 that are too large to affect the functionality of the solenoid assembly 68 (the particles being too large to fit between the valve seat 88 and the stopper portion 54 a ) when the armature 54 is in the open position.
The aperture 90 is also in fluid communication with a reservoir cavity, shown generally at 94 , formed as part of a reservoir 58 . The cavity 94 is also in fluid communication with a first check valve 60 and a second check valve 62 . The first check valve 60 includes a first vent port 64 , and the second check valve 62 includes a second vent port 66 . The check valves 60 , 62 and the vent ports 64 , 66 are substantially similar.
The first vent port 64 of the first check valve 60 includes a first cap portion 104 which is connected to a first flange portion 106 formed as part of the reservoir 58 . The connection between the cap portion 104 and the flange portion 106 may be any suitable connection, such as snap-fitting, welding, an adhesive, or the like. The connection between the cap portion 104 and the flange portion 106 forms a first check valve cavity, shown generally at 108 , and formed as part of a first side wall 110 of the reservoir 58 is a first check valve aperture 112 , which allows for fluid communication between the cavity 108 and the cavity 94 when the first check valve 60 is in an open position.
The first check valve 60 also includes a first valve member 114 , which in this embodiment is a first valve plate 114 , located in the first check valve cavity 108 , and includes a first seal member 116 that selectively contacts a first valve seat 118 and a first inner wall 120 of the cap portion 104 . The valve seat 118 at least partially surrounds the aperture 112 , and no air passes around the valve plate 114 when the seal member 116 is in contact with the valve seat 118 , where the first check valve 60 is in the closed position. The inner wall 120 is part of a first base portion 122 , and formed as part of the base portion 122 is a first plurality of vents 124 which are in fluid communication with the cavity 108 , such that when the seal member 116 is not in contact with the valve seat 118 , purge vapor is able to flow from the cavity 94 through the aperture 112 into the cavity 108 , and through the vents 124 and into the first vent port 64 .
Formed with the valve plate 114 is a first guide member 126 , which is cylindrical in shape, and partially extends into an aperture 128 formed as part of the side wall 110 , and also partially extends into another aperture 130 formed as part of the base portion 122 . The first guide member 126 is able to slide freely in the apertures 128 , 130 , and does not bias the valve plate 114 in a particular direction. The guide member 126 is able to slide freely in the apertures 128 , 130 because there is a clearance between the outer diameter of the guide member 126 and the diameter of each of the apertures 128 , 130 , and this clearance allows for some of the purge vapor to pass through the apertures 128 , 130 . However, when the seal member 116 is in contact with the valve seat 118 , purge vapor flowing through the clearance around the guide member 126 in the aperture 128 or through the aperture 112 does not flow around the valve plate 114 or the seal member 116 .
The second check valve 62 includes similar components to the first check valve 60 , and functions in a similar manner. The components of the second check valve 62 includes a second cap portion 104 a connected to the second flange portion 106 a of the reservoir 58 , and a second check valve cavity, shown generally at 108 a , formed by the connection of the cap portion 104 a to the second flange portion 106 a . A second side wall 110 a is also formed as part of the reservoir 58 , and a second check valve aperture 112 a is formed as part of the second side wall 110 a to provide fluid communication between the cavity 94 and the second check valve cavity 108 a . The second valve member 114 a having a second seal member 116 a is located in the second check valve cavity 108 a and selectively contacts the valve seat 118 a formed as part of the side wall 110 a and the inner wall 120 a formed as part of the a base portion 122 a . The base portion 122 a and the second cap portion 104 a are part of the second vent port 66 . Similarly to the first base portion 122 , there is a second plurality of vents 124 a formed as part of the second base portion 122 a . A second guide member 126 a is integrally formed with the valve plate 114 a , and the second guide member extends into the aperture 128 a formed as part of the second side wall 110 a and the aperture 130 a formed as part of the second base portion 122 a.
The air flow system 10 has multiple modes of operation. In a first mode of operation, when the turbocharger 14 is not active, air flows through the air box 12 , the turbocharger 14 , the throttle 16 , and into the intake manifold 18 . There is vacuum pressure in the intake manifold 18 created by the engine during the first mode of operation, drawing air into the intake manifold 18 . This vacuum pressure is also in the fourth conduit 20 d , and when the solenoid assembly 68 is in the open position, the vacuum causes the first check valve 60 to open, where during the first mode of operation, the vacuum pressure draws the valve plate 114 away from the valve seat 118 and toward the inner wall 120 , such that the seal member 116 contacts the inner wall 120 , allowing purge vapor to pass from canister 30 , through the sixth conduit 20 f , the cavity 92 of the overmold assembly 36 from an inlet port 132 connected to the sixth conduit 20 f , the aperture 90 , the cavity 94 of the reservoir 58 , through the aperture 112 , the valve cavity 108 , through the vents 124 , the first vent port 64 and into the fourth conduit 20 d . The purge vapor from flows through the fourth conduit 20 d , through the third conduit 20 c where the purge vapor mixes with air and flows into the intake manifold 18 . This same vacuum pressure also causes the second check valve 62 to close, where the vacuum pressure in the cavity 94 of the reservoir 58 draws the second valve plate 114 a towards the second valve seat 118 a , such that the second seal member 116 a contacts the valve seat 118 a , and the purge vapor does not pass through the second check valve 62 .
The air flow system also has a second mode of operation, where the turbocharger 14 is activated, and air flowing into the turbocharger 14 from the air box 12 is pressurized, the pressurized air flows through the throttle 16 , and the air then flows into the intake manifold 18 . In this second mode of operation, the manifold 18 is operating under positive pressure. Some of this pressurized air flows into the fourth conduit 20 d , and into the first vent port 64 . During the second mode of operation, the pressurized air then flows through the vents 124 and into the first check valve cavity 108 and applies pressure to the first valve plate 114 , moving the valve plate 114 towards the valve seat 118 such that the seal member 116 contacts the valve seat 118 , placing the first check valve 60 in the closed position.
When the turbocharger 14 is activated during the second mode of operation, and pressurized air is passing through the seventh conduit 20 g , the venturi valve assembly 24 , and the eighth conduit 20 h . The pressurized air flowing through the venturi valve assembly 24 also creates vacuum pressure in the fifth conduit 20 e , where air is drawn from the fifth conduit 20 e into venturi valve assembly 24 , such that the air passes through the eighth conduit 20 h and into the air box 12 . During the second mode of operation, this vaccum pressure in the fifth conduit 20 e also draws the second valve plate 114 a away from the second valve seat 118 a and towards the inner wall 120 a of the base portion 122 a , placing the second check valve 62 in an open position. During the second mode of operation, purge vapor from the canister 30 passes through the sixth conduit 20 f , the cavity 92 of the overmold assembly 36 from the inlet port 132 connected to the sixth conduit 20 f , the aperture 90 (when the solenoid assembly 68 is in the open position), the cavity 94 of the reservoir 58 , through the aperture 112 a , the valve cavity 108 a , through the vents 124 a , the second vent port 66 and into the fifth conduit 20 e . The purge vapor flows into the venturi valve assembly and mixes with the pressurized air in the eighth conduit 20 h , and flows into the air box 12 . The purge vapor and air mixture then flows through the turbocharger 14 , the throttle 16 , and into the intake manifold 18 .
The orientation of the turbo purge valve assembly 22 also has an effect on the operation of the turbo purge valve assembly 22 , since there are no springs or other biasing members in either of the check valves 60 , 62 to bias either of the check valves 60 , 62 to an open or closed position. In the embodiment shown in FIG. 1 , gravity biases the valve plate 114 of the first check valve 60 downward (towards the first valve seat 118 ), and therefore towards the closed position. However, it is within the scope of the invention that the turbo purge valve assembly 22 may be oriented such that gravity may bias the first valve plate 114 toward either the first valve seat 118 or the inner wall 120 . It is also within the scope of the invention that the turbo purge valve assembly 22 may be oriented such that gravity may bias the second valve plate 114 a toward either of the second valve seat 118 a or the second inner wall 120 a . The turbo purge valve assembly 22 is shown in different orientations in FIGS. 1-4 , where gravity biases the check valves 60 , 62 to either the open or closed positions, depending on the orientation of the valve assembly 22 .
Furthermore, the free movement of each of the valve plates 114 , 114 a in the respective check valve cavities 108 , 108 a also provides the advantage of reducing or eliminating turbo lag. Because there is no biasing member which biases either of the valve plates 114 , 114 a towards an open or closed position, the valve plates 114 , 114 a change position quickly between the open and closed positions as the manifold 18 changes from operating under vacuum pressure to positive pressure, when the turbocharger 14 is activated.
When the turbocharger 14 is generating pressurized air during the second mode of operation, and purge vapor is passing through the purge valve assembly 22 , some level of vaccum is detectable in the canister 30 by a pressure sensor 32 . By placing the solenoid assembly 68 in the closed position, flow through the venturi valve assembly 24 is reduced, exposing the sixth conduit 20 f and the canister 30 to less vacuum pressure, which is detected by the sensor 32 . If there is a pressure change detected by the sensor 32 in the canister 30 when the solenoid assembly 68 is changed between the open and closed positions, a malfunction has occurred, such as the sixth conduit 20 f becoming disconnected from either the canister 30 or the inlet port 132 , and a malfunction light may be used to alert the vehicle driver the malfunction has occurred.
Another function of the turbo purge valve assembly 22 is the relief of vacuum pressure in the canister 30 and the fuel tank of the vehicle after the vehicle is shut off. Due to fuel consumption over time, the fuel flows out of the fuel tank to the engine, creating vacuum pressure in the fuel tank and the canister. The turbo purge valve assembly 22 is capable of relieving this vacuum pressure. To relieve the vacuum pressure, the solenoid assembly 68 is pulsated after the vehicle is shut off. In one embodiment, the solenoid assembly 68 is pulsated at 10 Hz, but it is within the scope of the invention that the solenoid assembly 68 may be pulsated at other frequencies. This pulsation opens one of the check valves 60 , 62 to allow air to flow from one of the ports 64 , 66 into the cavity 94 , and then through the aperture 90 and into the cavity 92 . The air flows back into the cavity 92 , through the sixth conduit 20 f , the canister 30 , and into the fuel tank, relieving the vacuum pressure.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | An integrated valve assembly, which integrates two check valves and a solenoid assembly which functions as a purge valve. When the solenoid assembly is in an open position, during a first mode of operation, vacuum pressure places the first check valve in an open position and the second check valve in a closed position, and during a second mode of operation, pressurized air places the first check valve in a closed position, and vacuum pressure generated by a venturi valve member places the second check valve in an open position. Each check valve utilizes a nylon insert along with an over molded rubber seal. The design of the check valves prevents actuation at low vacuums and flows when the vehicle is shut off. The integrated valve assembly eliminates the need for an OBD relief valve, and simplifies the EVAP system, saving costs, complexity, and eliminates several possible leak connections. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to demodulation, and more particularly to demodulation of a burstwise signal transmitted over a channel that introduces unknown amplitude and phase changes in the burstwise signal. Even more particularly, the present invention relates to demodulation of burstwise communications signals, such as digital cellular telephone signals and the like, having been transmitted through air and having had unknown changes in amplitude and phase introduced thereinto.
In order to effectively operate in a coherent mode, i.e., a mode characterized by a fixed phase relationship between points on an electromagnetic wave, a receiver must determine phase (and possibly amplitude) distortions introduced by a channel through which a signal traverses in reaching the receiver. For mobile communications-type-channels such as cellular-type channels, in particular, the channel often fades rapidly such that significant changes can occur in phase and amplitude distortions, even over individual signal bursts. Hence, the receiver must repeatedly determine a time-varying estimate of the channel's phase and amplitude distortion characteristics. Nonetheless, coherent operation is highly desirable because capacity of, for example, cellular systems can be increased by about sixty percent (2dB) given constant voice quality.
Determination of a coherent frame-of-reference is frequently based on a portion of each signal burst made up of "known" data, i.e., made up of a sequence of symbols that are known a priori to the receiver. Such "known" data may be for example a synch pattern transmitted at a prescribed position within each signal burst. However, when no such "known" data, or synch pattern, (or an insufficient amount of "known" data) is present within signal bursts of a particular system, the receiver must make this determination "blindly", i.e., without the benefit of a priori knowledge of any significant portion of the signal burst.
In the event that known symbols are not available, one approach is to hypothesize all possible symbols, and to evaluate how well each such hypothesis matches the samples actually received. For example, when signal bursts of a length of 40 symbols and a duration of 2 milliseconds, with each symbol representing two bits of data, are utilized in a "blind" system, the total number of possible transmitted bit sequences per burst is 4 40 , i.e., approximately 1.2×10 24 . For each of these possible sequences, the phase and amplitude distortions of the channel could be estimated, and for each possible sequence, hypothesized data (i.e., the possible sequence) can be passed through the estimated channel. Differences between the hypothesized data having been passed through the estimated channel and the burst actually received can be squared and summed so as to yield a statistic, i.e., a measure of the similarity between the burst actually received and the hypothesized data having been passed through the estimated channel. The estimated channel and hypothesized data that together yield the lowest statistic can then be selected, and the selected estimated channel used to determine an estimate of the burst that was actually transmitted.
Unfortunately, this approach to channel estimation is computationally intractable. Thus, what is needed is an approach to blind demodulation of a coherent signal and more particularly to determining phase and amplitude distortions introduced by a channel through which such signal is transmitted that significantly reduces computational demands as compared to determining a channel estimate for every possible bit sequence for every burst and selecting the channel estimate with the smallest error statistic, while at the same time maintaining a high degree of accuracy in channel estimations.
The present invention advantageously addresses the above and other needs.
SUMMARY OF THE INVENTION
The present invention advantageously addresses the needs above as well as other needs by providing an approach to blind demodulation of burstwise communications signals, such as digital cellular telephone signals and the like, having been transmitted through air and having had unknown changes in amplitude and phase introduced thereinto.
In one embodiment, the invention can be characterized as a method of blindly estimating phase distortions introduced by a communications channel to a transmitted signal. The method involves dividing a portion of a received signal into a prescribed number of groups; determining a channel estimate for each of a plurality of possible data sequences that could have been transmitted in each group; generating a hypothesized received data sequence for each channel estimate by processing each of the plurality of possible data sequences through its channel estimate; determining an error statistic for each channel estimate, each error statistic being indicative of an amount by which each hypothesized received data sequence deviates from a corresponding actual received data sequence; selecting a plurality of the channel estimates for each group, the plurality of channel estimates being selected for each group for having smaller error statistics than another plurality of channel estimates not selected for each group; and selecting a best channel estimate for each group from the plurality of channel estimates having been selected for each group by finding a least error path through a trellis comprising the plurality of channel estimates having been selected for each group.
In another embodiment, the invention can be characterized as a method of blind channel estimation by receiving a signal burst over a communications channel; dividing the signal burst into a prescribed number of groups of symbols; hypothesizing all possible transmitted data sequences for each group; generating a corresponding channel estimate for each possible data sequence having been hypothesized for each group; determining an error measurement for each corresponding channel estimate having been generated; selecting a predetermined number of the corresponding channel estimates for each group from amongst the corresponding channel estimates having been generated for each group, the predetermined number of the corresponding channel estimates being selected for having smaller error measurements than remaining corresponding channel estimates not selected from amongst the corresponding channel estimates for each group; identifying a best channel estimate for each group from amongst the predetermined number of the corresponding channel estimates having been selected for each group; and reviewing the best channel estimate having been identified for each group.
The identifying of the best channel estimates involves forming a trellis with a number of epochs equal to the prescribed number, each epoch containing a number of states equal to said predetermined number, the states each being one of the predetermined number of channel estimates having been selected for each group; determining a branch metric for each possible pair of channel estimates from adjacent epochs as a function of a sum of the error measurement for the channel estimates of each possible pair, and as a function of a difference between the channel estimates of each possible pair; and finding a least cost path though the trellis using a Viterbi analysis in response to said branch metrics having been determined
The reviewing the best channel estimates having been selected involves defining a curve in two dimensional space, the curve including the best channel estimates having been identified for each group; defining a plurality of segments of the curve, the segments each including a plurality of the best channel estimates having been identified; determining smoothness of each of the plurality of segments of the curve by comparing the curve with a reference; selecting one of the plurality of segments in response to the determining of smoothness; and reidentifying best channel estimates for each group not in the plurality of groups for which the best channel estimates having been selected are included in the one of the plurality of segments having been selected, the reidentifying being so as to increase smoothness of another curve including the best channel estimates having been reidentified and the best channel estimates included in the one of the plurality of segments having been selected.
In a further embodiment, the invention can be characterized as a system for blindly estimating phase distortions introduced by a communications channel to a transmitted signal. The system has an antenna; a demodulator coupled to the antenna; an analog-to-digital converter coupled to the demodulator; and a processor coupled to the analog-to-digital converter.
The processor has means for dividing a portion of a received signal into a prescribed number of groups; means determining a channel estimate for each of a plurality of possible data sequences that could have been transmitted in each group; means for generating a hypothesized received data sequence for each channel estimate by processing each of the plurality of possible data sequences through its channel estimate; means for determining an error statistic for each channel estimate, each error statistic being indicative of an amount by which each hypothesized received data sequence deviates from a corresponding actual received data sequence; means for selecting a plurality of the channel estimates for each group, the plurality of channel estimates selected for each group being selected to have smaller error statistics than another plurality of channel estimates not selected for each group; and means for selecting a best channel estimate for each group from the plurality of channel estimates having been selected for each group by finding a least error path through a trellis comprising the plurality of channel estimates having been selected for each group.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein:
FIG. 1 is a block diagram of a communications system in which an embodiment of the present invention is utilized;
FIG. 2 is a representation of changes in phase and amplitude distortions introduced by a communications channel, such as shown in FIG. 1;
FIG. 3 is a block diagram system for channel estimate in accordance with the present embodiment;
FIG. 4 is a representation of a signal burst that has been divided into groups for which individual channel estimates and corresponding error statistics are generated for each possible data sequence that could have been received in each group by the system of FIG. 3;
FIG. 5 is a representation of a trellis having eight epochs, each having thirty-two possible states, through which a least cost path is determined by the system of FIG. 3;
FIG. 6 is a representation of a curve including eight best channel estimates, one from each group, and of a line (or reference) to which a segment of the curve is compared by the system of FIG. 3 in order to determine smoothness of the segment; and
FIG. 7 is a flow diagram of steps traversed by the system of FIG. 3 in order to determine a channel estimate in accordance with the present embodiment.
Corresponding reference characters indicate corresponding components throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the presently contemplated best mode of practicing the invention is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims.
Referring first to FIG. 1, a block diagram is shown of a communications system 10 employing a transmitter 12, a communications channel 14 and a receiver 16. As is frequently the case when the communications channel includes air, the communications channel 14 is responsible for subjecting a transmitted signal 18 from the transmitter 12 to Rayleigh fading. Distortions of the transmitted signal's phase and amplitude occur as a result of Rayleigh fading.
Within the receiver 16 is a demodulator that operates coherently. Problematically, such coherent operation, while desirable, is not possible unless the phase (and possibly amplitude) distortions of the communications channel 14 traversed by a received signal 20 can be accurately tracked.
Heretofore, known information, such as a synch pattern, within each of a plurality bursts in the received signal has been used to approximate the phase and amplitude distortions introduced by the communications channel 14, thereby enabling the demodulator to approximate the phase and amplitude distortions in unknown portions of a signal burst with reasonable accuracy.
When, however, the received signal contains no known portions, or relatively small known portions, i.e., less than 10% of each signal burst, such an approach becomes impossible or impractical.
In sum, when Rayleigh fading occurs, estimating the channel is challenging, and typically leads to performance degradation, however, channel estimation is much easier when an appreciable portion of the transmitted information is known to the receiver. This known portion gives the receiver a basis for forming an initial estimate of the channel's characteristics. Without such a priori knowledge of at least a portion of the transmitted information, however, the receiver must base all of its estimates on noisy, phase and amplitude distorted, unknown samples.
Referring next to FIG. 2, a representation is shown of changes in phase and amplitude distortions introduced by a particular communications channel over time. The representation is shown as a curve 32 in two-dimensional complex space. The representation is over 40 symbols within a particular signal burst. Problematically, these particular variations in phase and amplitude distortion over such signal burst are not, in practice, known a priori. Thus, it is necessary for coherent operation to estimate these variations based on the received signal only.
Referring next to FIG. 3, a block diagram is shown of a system for channel estimation based solely on received symbols having already been distorted in phase and amplitude by the channel through which such symbols are transmitted.
As mentioned above, when none of, or only a small number of, the symbols having been transmitted are known to the receiver, it becomes necessary to generate channel estimates based solely or primarily on received symbols that have already been distorted in phase and amplitude by the channel.
The present approach utilizes an antenna 50 to receive a signal 52 (hereinafter the received signal 52) that is made up of a plurality of signal bursts. The received signal 52 is passed through a bandpass filter 54, such as is known in the art, and a demodulator 56, such as is also known in the art.
Next, the received signal 52 is digitized by an analog-to-digital converter 58 and then segmented into groups of contiguous samples within each burst. For example, as shown in FIG. 4, each burst 100 (FIG. 4), which may be made up of 40 symbols 102 and may be divided into groups 104 (FIG. 4) of five symbols per group, thus yielding eight groups per burst. These groups 104 (FIG. 4) of symbols are passed by the analog-to-digital connector 58 (FIG. 3) to a channel determination error estimation module 60 (FIG. 3).
For each of the possible data sequences transmitted during each of the eight groups 104 (FIG. 4), corresponding phase and amplitude distortions of the channel are estimated by the channel determination/error estimation module 60 (FIG. 3). Note that for each group 104 (FIG. 4), there are 45, i.e., 1024 possible transmitted bit sequences 106 (FIG. 4). Thus, 8 groups 104 (FIG. 4)×1024 possible transmitted bit sequences 106 (FIG. 4) per group, i.e., 8192 possible transmitted bit sequences and 8192 corresponding estimates 108 (FIG. 4) of the phase and amplitude distortions introduced by the channel are generated, which is far fewer than the 1.2×10 24 estimates of the phase and amplitude distortions of the channel that could be estimated, if all possible transmitted bit sequences throughout each signal burst were used in generating estimates of phase and amplitude distortions of the channel.
Next, the channel determination/error module 60 (FIG. 3) determines for each of the eight groups 104 (FIG. 4), the "best" thirty-two estimates 62 of the phase and amplitude distortions of the channel from amongst the 1024 estimates for each of the eight groups. The selection of the thirty-two best estimates 62 (FIG. 3) is based on a statistic 110 (FIG. 4) generated by determining differences between the hypothesized data having been passed through the estimated channel, and the symbols actually received. Each of the thirty-two best estimates in each of the eight groups, has an associated error statistic 110 (FIG. 4), and a location in two-dimensional space.
Note that the 1024 cases (estimates) to be considered for each group can be reduced to 256 if the phase of one of the five symbols (in each estimate) is fixed. (This is because for any given set of unknown received samples, there are four sets of data (i.e., cases) that equally well correspond to such samples. This is because 90° rotations of the whole sequence are equally valid when the samples are unknown, thus creating a four-way ambiguity.) The four way ambiguity in the one of the five symbols for which phase is fixed can be resolved in a trellis structure (see below) by allowing each of four 90° rotations when assigning distance metrics between states (and selecting a least distance metric).
Next, one "best" estimate for each group (to be selected from amongst the thirty-two "best" estimates for each group) is identified by a channel selection module 64 (FIG. 3). Such identification is based on an assumption that the one "best" estimate for each group should be similar to, i.e., not very different from the one "best" estimates selected for each adjacent group. This is because the channel is assumed not to have changed very much over each group of symbols.
Referring to FIG. 5, to select the one best estimate 202 (FIG. 5) for each group, a trellis 200 (FIG. 5) is created by the channel selection module 64 (FIG. 3) with eight epochs, all containing thirty-two states. The "least cost" path though the trellis 200 (FIG. 5) is determined by employing branch metrics. Specifically, a combined error, or branch metric, is determined for each possible pair of the best thirty-two states from adjacent groups of states as a weighted sum of the error originally associated with each of the thirty-two best states, i.e., the error originally used by the channel determination/error estimation module 60 (FIG. 3) to select the thirty-two best states, and of the square of the difference between the each of the thirty-two best states in one of the groups, and each of the thirty-two best states in an adjacent group. In other words, the branch metric is a function of the statistic associated with the one state in one group, the statistic associated with one state in an adjacent group, and a statistic proportional to the distance between the location of such states in two-dimensional space.
After forming this trellis, and after tracing it back, the one best estimate 202 (FIG. 5) for each of the eight groups is selected by the channel selection module 64 (FIG. 3) based on a Viterbi analysis, as described below. As shown in FIG. 6, these eight best estimates 202 (FIGS 5 and 6) (one for each group) define a curve 300 (FIG. 6) in two dimensional space that provides an estimate as to how the channel varied over the burst.
As mentioned above, the determination as to the one best state for each group (which, if made blindly, would include 32 8 possibilities, i.e., 1.10×10 12 ) can be based on a Viterbi analysis of all of the possible sequences of states. The Viterbi analysis allows the sequence of states resulting in the least total combined error to be determined in many fewer calculations than if a blind determination were made (i.e., 7×(32 2 ), i.e., 7168 calculations).
Viterbi analysis, which is well known in the art, involves determining the error statistic for each state in the first group, i.e., the error originally used to select the thirty-two best states. Next, such analysis involves, for each of the thirty-two best states in each subsequent group, considering each predecessor state, i.e., each of the thirty-two states in the immediately previous group, and determining, for each possible pair of one predecessor state and one subsequent state, a total error made up of (i) the sum of the error associated with the predecessor state, and the error associated with the subsequent state; plus (ii) the error associated with the transition leading from the predecessor state to the subsequent state. The pair of states corresponding to the smallest total error is selected, and the total error and predecessor state associated with the smallest total error are stored for later recall.
In the final group, the state, among the thirty-two possible best states, that has the smallest total error is selected. This final state with the smallest total error, is the "end" of the best path through the eight groups.
Next, the Viterbi analysis involves tracing back through the remembered predecessor states to find the complete "best path" 66 (FIG. 3), i.e., the sequence of states with the least combined total error. Such "tracing back" is known in the art.
While, the Viterbi analysis finds the "path" 66 (FIG. 3) in two-dimensional space that minimizes combined total error of the states relative to one another, it does nothing to evaluate the "smoothness" of the channel estimate curve 300 (FIG. 6) through two-dimensional space. However, because the ability of a real-world communications channel to change quickly is, as a practical matter, limited, the result of the Viterbi analysis is next reviewed by a channel selection connection module 68 (FIG. 3) to assure that the selected "best" path 66 (FIG. 3) represents a relatively "smooth" path through two-dimensional space.
Hence, secondary processing is performed by the channel selection connection module 68 (FIG. 3) in order to select a portion of the path 66 (FIG. 3) resulting from the Viterbi analysis that corresponds, i.e., best fits, to a reasonably smooth line or path 302 (FIG. 6) through two-dimensional space, as would be expected in a real-world channel. For example, the "line" searched for may be a "best fit" straight line, or, in accordance with other embodiments, higher order polynomials.
This "best fit"-type of analysis involves considering hypothesized contiguous segments of the selected best path 66 (FIG. 3) made up of the selected best states from several adjacent groups of states. These segments are selected, for example, to have lengths of from, for example, four to eight, or six to eight states, i.e., from four or six to eight of the "best" states making up the selected best path 66 (FIG. 3). For each hypothesized contiguous segment, an error statistic, such as a sum-squared-error, is calculated indicative of the deviation of the hypothesized contiguous segment from a "best fit" straight line 302 (FIG. 6) through the states making up such segment. A bias factor is applied to favor longer segments (so as to favor using more available information). The segment with the smallest error statistic (after bias is applied) is selected as the basis for an extrapolation to create a final channel estimate 70 (FIG. 3), i.e., path through two-dimensional space.
The bias factor applied to favor longer segments may for example involve dividing the error statistic by the length of the segment in question in states, e.g., 4 states, 5 states, 6 states, 7 states or 8 states, raised to some power, e.g., 1.5.
If the one "best" states (if any) from groups not in the selected segment represent a substantial deviation from the "best fit" line 302 (FIG. 6), another "best" state is selected for such group by the channel selection connection module 68 (FIG. 3) from amongst the thirty-two best states in such group, regardless of the fact that the other "best" state may result in a larger total combined error from a Viterbi analysis point of view. After the other "best" state or states are selected, the final channel estimate 70 (FIG. 3), i.e., path through two-dimensional space, is complete.
Advantageously, the final channel estimate 70 (FIG. 3) represents very accurately the actual channel through which the received signal has passed. Thus, the final channel estimate can be applied by a distortion elimination module 72 (FIG. 3) to the burst actually received in order to determine an estimate of the burst actually transmitted 74 (FIG. 3), which is of course what is ultimately needed. Once the estimate of the burst actually transmitted 74 (FIG. 3) is determined, it can be processed in a conventional manner consistent with the communications system with which the present embodiment is employed.
For example, if the system with which the present embodiment is employed is a cellular telephone system, a mobile radio system, or the like, the estimate of the burst actually transmitted 74 (FIG. 3) could have any of four phases. If some small number of symbols throughout the burst, e.g., three, are known to a receiver, they can be applied in determining the burst's phase, by, for example, determining the squared error of the known symbols under each phase, and selecting the phase that yields the least squared error. Next, if the burst is a voice burst, it can be decoded and used to generate speech from a speaker, or, if the burst is a control burst, it can be used to generate control signals within a remote cellular telephone, such as is well known in the art.
Referring to FIG. 7, a flow diagram is shown of steps traversed by the system for channel estimation in response to a control program in order to determine a channel estimate in accordance with the present embodiment.
After the control program is initiated (Block 1000), the received signal 52 (FIG. 3) is received (Block 1002), and then is segmented (Block 1004) into groups of contiguous samples within each burst. For example, as shown in FIG. 4, each burst 100 (FIG. 4), which may be made up of -40 symbols 102 and may be divided into groups 104 (FIG. 4) of five symbols per group, thus yielding eight groups per burst.
For each of the possible data sequences transmitted during each of the eight groups 104 (FIG. 4), corresponding phase and amplitude distortions of the channel are estimated (Block 1004). Note that for each group 104 (FIG. 4), there are 4 5 , i.e., 1024 possible transmitted data (bit) sequences 106 (FIG. 4). Thus, 8 groups 104 (FIG. 4)×1024 possible transmitted bit sequences 106 (FIG. 4) per group, i.e., 8192 possible transmitted bit sequences and 8192 corresponding estimates 108 (FIG. 4) of the phase and amplitude distortions introduced by the channel are generated (Block 1006).
Next, the "best" thirty-two estimates 62 (FIG. 4) of the phase and amplitude distortions of the channel are selected (Block 1008) from amongst the 1024 estimates for each of the eight groups. The selection of the thirty-two best estimates 62 (FIG. 3) is based on a statistic 110 (FIG. 4) generated by determining differences between the hypothesized data having been passed through the estimated channel, and the bursts actually received. Each of the thirty-two best estimates in each of the eight groups, has an associated error statistic 110 (FIG. 4), and a location in two-dimensional space.
Note that the 1024 cases (channel estimates) to be considered for each group can be reduced to 256 if the phase of one of the 5 symbols (in each estimate) is fixed. (See explanation above in reference to FIG. 2). The 4 way ambiguity in the one of the 5 symbols for which phase is fixed can be resolved in a trellis structure.
Next, one "best" estimate for each group (to be selected from amongst the thirty-two "best" estimates for each group) is identified (Block 1010). As mentioned above, such identification is based on an assumption that the one "best" estimate for each group should be similar to, i.e., not very different from the one "best" estimates selected for each adjacent group. To select the one best estimate 202 (FIG. 5) for each group, a trellis 200 (FIG. 5) is created with eight epochs, all containing thirty-two states. The "least cost" path through the trellis 200 (FIG. 5) is determined by employing branch metrics. Specifically, the combined error, or branch metric, is determined for each possible pair of the best thirty-two states from adjacent groups of states as a weighted sum of the error originally associated with each of the thirty-two best states, i.e., the error originally used by the channel determination/ error estimation module 60 (FIG. 3) to select the thirty-two best states, and of the square of the difference between the each of the thirty-two best states in one of the groups, and each of the thirty-two best states in an adjacent group.
After forming this trellis, and after tracing it back, the one best estimate 202 (FIG. 5) for each of the eight groups is selected (Block 1010) based on a Viterbi analysis, such as described above in reference to FIGS 3 and 5.
The eight "best" estimates 202 (FIG. 5) (one for each group) define the curve 300 (FIG. 6) in two dimensional space that provides an estimate as to how the channel varied over the burst. Because the ability of a real-world communications channel to change quickly is, as a practical matter, limited, and the result of the Viterbi analysis not, the result of the Viterbi analysis is next reviewed (Block 1012) to assure that the selected "best" path 66 (FIG. 3) represents a relatively "smooth" path through two-dimensional space.
Hence, secondary processing is performed (Block 1012) in order to select a portion of the path 66 (FIG. 3) resulting from the Viterbi analysis that corresponds to a reasonably smooth line or path 302 (FIG. 6) through two-dimensional space, as would be expected in a real-world channel. As mentioned above, the "line" searched for may be a straight line, or, in accordance with other embodiments, higher order polynomials.
This "best fit" -type of analysis involves considering hypothesized contiguous segments of the selected best path 66 (FIG. 3) made up of the selected best states from several adjacent groups of states. These segments are selected, for example, to have lengths of, for example, from four to eight, or from six to eight states, i.e., from four or six to eight of the "best" states making up the selected best path 66 (FIG. 3). For each hypothesized contiguous segment, an error statistic, such as a sum-squared-error, is calculated indicative of the deviation of the hypothesized contiguous segment from the "best fit" straight line 302 (FIG. 6) through the states making up such segment. A bias factor is applied to favor longer segments (so as to favor using more available information), and the segment with the smallest error statistic (after bias is applied) is selected as the basis for an extrapolation to create a final channel estimate 70 (FIG. 3), i.e., path through two-dimensional space.
If the one "best" states from groups (if any) not in the selected segment represent a substantial deviation from the "best fit" line 302 (FIG. 6), another "best" state is selected for such group from amongst the thirty-two best states in such group, regardless of the fact that such other "best" state may result in a larger total combined error from a Viterbi analysis point of view. After the other "best" state or states are selected, the final channel estimate 70 (FIG. 3), i.e., path through two-dimensional space, is complete (Block 1014).
While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims. | A system and method of blind channel estimation to receive a signal burst over a communications channel; divide the signal burst into a prescribed number of groups of symbols; hypothesize all possible transmitted data sequences or each group; generate a corresponding channel estimate for each possible data sequence; determine an error measurement for each corresponding channel estimate; select a number of the corresponding channel estimates for each group from amongst the corresponding channel estimates, the number of the corresponding channel estimates being selected for having smaller error measurements than remaining corresponding channel estimates not selected; identifying a best channel estimate for each group from amongst the number of the corresponding channel estimates having been selected for each group; and reviewing the best channel estimate having been identified for each group and reidentifying best channel estimates for some of the groups so as to increase smoothness of a curve in two-dimensional space made from the reidentified best channel estimates and the best channel estimates for remaining groups for which no reidentification is made. | 7 |
FIELD OF THE INVENTION
The present invention relates to a method of protecting a microcomputer system against manipulation of its program. The microcomputer system includes a rewritable memory in which at least one portion of the program is stored. In this method, a check is performed as part of a checking procedure to determine whether at least one portion of the rewritable memory includes a specified content.
The present invention also relates to a microcomputer system which is protected against manipulation of its program. The microcomputer system includes a rewritable memory in which at least one portion of the program is stored. In addition, the microcomputer system includes for its protection a checking arrangement for checking on whether at least one portion of the rewritable memory includes a preselected content.
BACKGROUND INFORMATION
A method and a microcomputer system for protecting against manipulation of a program is referred to in German Published Patent Application No. 197 23 332, for example. The method discussed in German Published Patent Application No. 197 23 332 is used in particular to protect an automotive control device against manipulation of its control program. The control device controls and/or regulates automotive functions, for example of an internal combustion engine, an electronic control (steer-by-wire) or an electronic brake (brake-by-wire). In the method discussed in German Published Patent Application No. 197 23 332, a boot routine is executed each time the microcomputer system is powered up, a checking procedure is executed as part of the boot routine. The checking procedure is implemented, for example, as a checking program, which is stored in a read-only memory of the microcomputer system. In execution of the checking procedure, a code word is determined from at least one portion of the memory content of the rewritable memory with the help of an encryption algorithm and compared with a reference code word stored in the rewritable memory. The code word is a checksum, for example. Execution of the control program stored in the rewritable memory of the control device is blocked if the code word determined is not the same as the reference code word.
If a manipulated program has been stored in the rewritable memory, the code word determined via the memory content of the rewritable memory will usually differ from the reference code word stored, and execution of the manipulated program is blocked. This prevents the automotive functions or automotive units that are to be regulated or controlled by the control device from being damaged by manipulation of the control program.
Various encryption algorithms may be used to form the code word. In particular, cross-checksums and/or longitudinal checksums may be formed (even parity check) or a cyclic redundancy check (CRC) may be used, in which code words are generated in blocks from the content of the rewritable memory and compared with reference code words. The more complex the encryption algorithms used to calculate the code word, the more difficult it is for an unauthorized third party to overcome the protection against manipulation and tuning. On the other hand, a complicated encryption algorithm requires a great deal of computation capacity (memory and computing time) of a computer core, in particular a microprocessor, of the microcomputer system. However, it is problematical that unlimited time is not available for checking the content of the rewritable memory in a microcomputer system. There is thus a destination conflict between secure and reliable protection against manipulation and tuning of a microcomputer system and rapid execution of the checking procedure without any significant delay in execution of the program.
In a microcomputer system, the power of the microprocessors used is not unlimited for reasons of cost and configuration (high-power microprocessors require a relatively large structure, have a relatively high power consumption and generate a great deal of waste heat which is dissipated from the microcomputer system). For this reason, the checking procedure in other prior systems is executed only at certain points in time when more time is available for complete processing of the checking program, e.g., when powering up the microcomputer system or after reprogramming or new programming of the rewritable memory. As an alternative, it may also be allowed to process only a portion of the checking program, which takes less time but reduces the certainty and reliability of the protection against manipulation and tuning.
If the checking procedure reveals that the checked portion of the rewritable memory includes a specified content, a corresponding marker is stored in a memory of the microcomputer system. By querying this marker at later points in time, e.g., each time the microcomputer system is powered up, it is allowed within an extremely short period of time to check on whether or not the program stored in the rewritable memory has been manipulated. In the method discussed in German Published Patent Application No. 197 23 332, however, no check of the content of other portions of the rewritable memory or even the entire rewritable memory during operation of the microcomputer system, i.e., while the program is running, is performed. Another check is performed only on reaching the point in time for performing the checking procedure again, e.g., when powering up the microcomputer system again. In the exemplary method according to the present invention, it may therefore take a relatively long time until manipulation of the program of a microcomputer system is detected and suitable countermeasures have been taken.
SUMMARY OF THE INVENTION
It is an object of the exemplary embodiment and/or exemplary method of the present invention to reliably and with certainty protect a microcomputer system against manipulation of its program, so that manipulation is detectable within the shortest period of time.
The exemplary embodiment and/or exemplary method of the present invention provides that the checking procedure be executed cyclically at preselectable intervals during operation of the microcomputer system.
According to the exemplary embodiment and/or exemplary method of the present invention, the checking procedure is thus executed not only at discrete points in time, e.g., following a reprogramming or new programming of the rewritable memory, but instead cyclically during normal operation of the microcomputer system, i.e., when running the program. Cyclic execution of the checking procedure may be performed in addition to or instead of execution of the checking procedure at discrete points in time, e.g., after reprogramming or new programming of the rewritable memory. The portion of the checking procedure executed during a cycle is reduced so that running of the program is hardly impaired by a computer core, in particular by a microprocessor, of the microcomputer system. A reduction in the checking procedure may be achieved, for example, by checking only a small portion of the rewritable memory in each cycle. The entire rewritable memory may be checked according to the present invention after only a relatively short operation of the microcomputer system and repeated execution of various portions of the checking program. If it is found in execution of the checking procedure that the rewritable memory or the checked portion of the rewritable memory does not include a specified content, suitable measures are initiated immediately. For example, the program or the checked portion of the program is declared invalid immediately and execution of the program, i.e., the checked portion of the program, is blocked immediately.
Various checking procedures which may be used in conjunction with the exemplary embodiment and/or exemplary method of the present invention are referred to in other prior systems. First, a method referred to in German Published Patent Application No 197 23 332 may be used, for example. In this method, a code word, e.g., a checksum, is formed over the rewritable memory or at least one portion of the rewritable memory and compared with a reference code word. In addition, the content of the rewritable memory may be marked or encrypted on the basis of an asymmetrical encryption method within the checking procedure. By checking the signature of decryption of a reprogrammed or newly programmed program, it may be ascertained as to whether or not the new program has been manipulated. Finally, as other method markers may be introduced into the program at defined locations and checked according to specified procedures. This method may allow low demand on the computing capacity of the microcomputer system. The disadvantage, however, is that the content of a program to be checked does not enter into the check and therefore only another completely different program without markers is detectable as manipulated.
According to an exemplary embodiment of the present invention, execution of the program may be blocked immediately as part of the checking procedure if the rewritable memory or a portion thereof does not include the specified content. Due to the fact that execution of the program is blocked immediately following the cyclically executed checking procedure if it is found to have been manipulated, rapid and reliable blocking of execution of the program is allowed, thus promptly preventing damage to a unit controlled or regulated by the microcomputer system.
According to an exemplary embodiment of the present invention, various portions of the rewritable memory may be checked by the checking procedure within a plurality cycles. The portions of the rewritable memory to be checked during a cycle of the checking procedure may be selected either randomly or on the basis of a predefined algorithm. In the case of a fixed algorithm, it may be predicted as to exactly when the entire rewritable memory has been checked. In the case of a random selection of the portion of the rewritable memory to be checked, it may be determined statistically as to when the entire rewritable memory has been checked. The size of the portions of the rewritable memory to be checked within a cycle depends on the computing power of the computer core of the microprocessor system and the available computation time. The size of the portions should be selected so as to prevent any negative effect on execution of the program due to the execution of the checking procedure.
According to another exemplary embodiment of the present invention, a preselectable marker is stored in a storage area of the microcomputer system if the rewritable memory or a portion thereof includes the specified content; the content of the storage area is checked during the execution of the program; and the marker is deleted to block the execution of the program. The presence of the marker in the storage area of the microcomputer system thus means that the program stored in the rewritable memory has not been manipulated. The marker is deleted when manipulation of the program is detected. The marker is in the form of a test pattern, for example. It may include one bit, multiple bits or even one or more bytes.
According to an alternative exemplary embodiment of the present invention, a storage area of the microcomputer system is checked during execution of the program, and a preselectable marker is stored in the storage area to block execution of the program. According to this alternative exemplary embodiment, the storage area of the microcomputer system thus does not have any marker with a non-manipulated program. However, if manipulation of the program is detected, a corresponding marker is stored in the storage area. According to another exemplary embodiment of the present invention, the cyclic execution of the checking procedure may run as a background application during operation of the microcomputer system. The checking procedure is thus always active in the background of running the program by the computer core and is called up cyclically at preselectable points in time.
According to an alternative exemplary embodiment of the present invention, the cyclic execution of the checking procedure may run at noncritical running times during operation of the microcomputer system. Noncritical running times are understood to be points in time when running time does not play a role, i.e., utilization of the computer core due to running of the program is low. This is the case, for example, during steady-state operation of the microcomputer system.
In addition, a use of the exemplary method according to the present invention for protecting an automotive control device against manipulation of its control program includes using the control device to control and/or regulate an automotive function.
The checking arrangement may also execute the check of the rewritable memory cyclically at preselectable intervals during operation of the microcomputer system.
According to an exemplary embodiment of the present invention, the rewritable memory may be configured as an EPROM (erasable programmable read-only memory) or an EEPROM (electronically erasable programmable read-only memory), in particular as a flash memory.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an exemplary microcomputer system according to the present invention.
FIG. 2 shows an exemplary flow chart of a method according to the present invention.
DETAILED DESCRIPTION
FIG. 1 shows a microcomputer system 1 including a computer core 2 (central processing unit, CPU) and multiple memories 3 , 4 , 5 . Memories 3 , 4 , 5 are connected to one another and to computer core 2 via a data connection 6 which is configured as a bus system in the present exemplary embodiment.
Memory 3 is a read-only memory, ROM, memory 4 is a read-write memory (random access memory, RAM) and memory 5 is a rewritable memory (erasable programmable read-only memory, EPROM, electronically erasable programmable read-only memory, EEPROM or flash EPROM). Program commands or data processed by computer core 2 is stored in memories 3 , 4 , 5 . Different data or programs are stored according to the type of memory 3 , 4 , 5 .
Read-only memory 3 contains a fixedly stored program which is alterable only by establishing a new memory module. Therefore, this memory 3 usually holds only a minimum program which enables computer core 2 to execute commands stored in other storage media, in particular in rewritable memory 5 . Read-write memory 4 is capable of storing data only during ongoing operation of microcomputer system 1 and is therefore only used as storage for data or program commands during ongoing operation of microcomputer system 1 . The memory content of read-write memory 4 may be accessed particularly rapidly, so that to some extent, programs may be transferred to read-write memory 4 from other storage media, e.g., from read-only memory 3 or from rewritable memory 5 , to be executed from there. Rewritable memory 5 , which is executed as an EPROM or a flash EPROM in the present exemplary embodiment contains program sections or data that are to be alterable within certain limits. This allows adaptation of microcomputer system 1 to different tasks. This is important in particular when microcomputer system 1 is used as a control device for a motor vehicle. Then in addition to the minimum program, the control program for the internal combustion engine or other automotive functions is also stored in read-only memory 3 . Then data, e.g., parameters or limiting values for operation of the internal combustion engine accessed by the control program, is stored in rewritable memory 5 .
Furthermore, additional program modules which are not to be implemented in each control device, for example, may be stored in rewritable memory 5 . Thus a control device may be used for different applications. The control and regulatory functions which are the same for all applications are stored in read-only memory 3 , while the programs or data, which differ in the individual applications, are stored in rewritable memory 5 .
However, it may be problematical that this increased flexibility may be associated with the risk that unauthorized parties might alter the memory content of rewritable memory 5 . When used in a motor vehicle, for example, the power of the internal combustion engine could be increased in this manner by replacing programs or data in rewritable memory 5 . However, this increase in power through manipulation of the control program or data may lead to an overload on the engine and ultimately even to an engine defect. To prevent such unwanted manipulation of the memory content of rewritable memory 5 , a checking program is provided in read-only memory 3 for executing a checking procedure capable of investigating the content of memory 5 for such inadmissible changes.
Various checking procedures of other systems may be available and may be used as part of the exemplary embodiment and/or exemplary method of the present invention. In particular, a checking procedure which checks for the presence of markers in the program may be used, the markers having been introduced into the program previously at defined locations. As part of the checking procedure, however, a code word, e.g., a checksum, may also be formed over the content of rewritable memory 5 or a portion thereof and then compared with a reference code word. The code word calculation may include the entire program stored in rewritable memory 5 or only portions of the program, depending on the version. The computing time for calculation of the code word is proportional to the size of the storage area to be checked. Depending on the available computing time, the size of the storage area to be checked may therefore be selected so that there is no excessively great burden on execution of the program. Finally, a checking procedure which calculates a signature over the program may also be used, a microcomputer-individual or application-specific value optionally is used as additional information. The signature may be executed, for example, on the basis of an asymmetrical encryption method using a public key accessible to anyone plus a private key accessible to only a limited user group.
FIG. 2 shows a flow chart of an exemplary method according to the present invention. This method begins in a function block 9 . In a function block 10 the checking procedure is executed to check on the content of a portion 5 a of rewritable memory 5 for manipulated data. A query block 11 then checks to determine whether the check of rewritable memory 5 or portion 5 a thereof was successful. If not, this means that manipulation of the program stored in rewritable memory 5 has been detected. A query block 12 then checks to determine whether a marker 7 , e.g., a test pattern, has already been stored in a preselectable storage area 5 b of rewritable memory 5 . If that is the case, marker 7 is deleted in a function block 13 , i.e., the test pattern is destroyed. If the checking procedure executed in query block 11 was successful, the sequence branches off from query block 11 to query block 14 , where a check determines whether a marker 7 has already been stored in preselectable storage area 5 b of rewritable memory 5 . If not, then a corresponding marker 7 is stored in a function block 15 to document the validity of the program. The checking procedure is concluded in a function block 16 .
Then in a query block 17 , a check determines whether the program stored in rewritable memory 5 is to be executed. If so, the program is initialized in a function block 18 , i.e., the necessary measures are executed to prepare computer core 2 for running the program. Internal registers of computer core 2 are set at initial values, and computer core 2 is thereby enabled to perform input and output operations necessary for execution of commands. After execution of this boot routine in function block 18 , the content of preselectable storage area 5 b of rewritable memory 5 is queried in a function block 19 . Then a query block 20 checks whether or not marker 7 has been stored in preselectable storage area 5 b . If no marker 7 has been stored, this means that the program has been recognized as having been manipulated. Consequently, the sequence branches off to a function block 21 and (further) execution of the program is blocked. As an alternative, other measures may also be taken in response to detection of manipulated data, e.g., emergency operation of the microcomputer system using specified parameters and limiting values. The exemplary method according to the present invention is terminated in a function block 22 .
However, if the query in query block 20 has shown that marker 7 has been stored in preselectable storage area 5 b , the sequence branches off to a function block 23 , where the program is executed (further). The program is executed as long as there is no request for renewed execution of the checking procedure. This request may be made at either precisely preselectable or randomly selected points in time during execution of the program. If such a request has been made (function block 24 ), the sequence branches back to function block 10 and the checking procedure is executed again. In the new cycle, a different portion of memory 5 is checked from that in the first cycle, so that entire memory 5 is checked after a plurality of cycles.
Microcomputer system 1 is configured as a control device for a motor vehicle for controlling and/or regulating automotive functions, e.g., in an internal combustion engine, an electronic steering or an electronic brake. Through the exemplary method according to the present invention, manipulation of the control program or of parameters or limiting values of the control device may be detected within a very short period of time. In addition, with the exemplary method according to the present invention, a manipulated control program may be blocked within a very short period of time, so that further execution of the control program is no longer allowed. After blocking the control program, the control device may be either shut down or switched to an emergency operation mode, so that automotive functions which are to be controlled and/or regulated may be maintained in an emergency even when the control program is blocked. | A method of protecting a microcomputer system against manipulation of its program, in which the microcomputer system includes a rewritable memory in which at least one portion of the program is stored, and in which a check is performed as part of a checking procedure to determine whether at least one portion of the rewritable memory includes a specified content. To permit detection of a manipulated program in the shortest amount of time, the checking procedure is executed cyclically at preselectable intervals during operation of the microcomputer system. In addition, execution of the program is blocked immediately as part of the checking procedure if the rewritable memory or a portion thereof does not include the specified content. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Provisional Application No. 61/996,308, filed May 5, 2014.
TECHNICAL FIELD
[0002] The current document is directed to a dental-hygiene tool and, in particular, to a dental-hygiene tool that facilitates teeth cleaning by orthodontics patients wearing braces and other orthodontic devices, fixtures, and appliances that hinder use of standard dental floss.
BACKGROUND
[0003] Braces are a common orthodontic appliance used for straightening teeth. Braces includes brackets, attached to the front sides of teeth, and wires that fit through slots in the brackets in order to apply force to reposition teeth, over time. Braces may also include metal bands, and other components. Although useful in correcting undesirable positions and arrangements of teeth, braces may inhibit proper cleaning and maintenance of teeth, including both brushing and use of dental floss. Regular use of dental floss ameliorates problems such as gingivitis, cavities, tartar, demineralization, and bad breath due to bacteria and other organisms. While a person without braces can generally floss his or her teeth within around two minutes, an orthodontics patient with braces may spend 15 minutes or more to adequately floss his or her teeth.
[0004] Numerous different dental-floss threading devices have been developed and proposed to facilitate use of dental floss. However, many of these devices have improper dimensions and shapes for use by orthodontics patients and often require tedious threading operations that are difficult and frustrating for younger children and orthodontics patients lacking adequate near vision and dexterity. For this reason, use of dental floss remains a challenging, tedious, and frustrating endeavor for many orthodontics patients.
SUMMARY
[0005] The current document is directed to a dental-hygiene tool to facilitate flossing of teeth, particularly for orthodontics patients wearing braces or other orthodontic devices, fixtures, and appliances that hinder use of standard dental floss. The currently disclosed dental-hygiene tool includes a hook-shaped tip to which a length of dental floss is attached. The hook-shaped tip has a blunt tip to prevent gum injuries during use and is sufficiently rigid to facilitate navigation through orthodontics fixtures and appliances, including braces.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 illustrates one implementation of the dental-hygiene tool to which the current document is directed.
[0007] FIGS. 2A-E illustrate an example use of the dental-hygiene tool to which the current document is directed.
[0008] FIG. 3 illustrates certain of the dimensions of one implementation of the hook-shaped tip of the currently disclosed dental-hygiene tool.
DETAILED DESCRIPTION
[0009] FIG. 1 illustrates one implementation of the dental-hygiene tool to which the current document is directed. The dental-hygiene tool includes a hook-shaped tip 102 within which a length of dental floss 104 is attached. In the implementation illustrated in FIG. 1 , the hook-shaped tip includes an inner cylindrical chamber in the handle end 106 into which the length of dental floss is inserted and attached. In the illustrated implementation, the handle end has a diameter of between 0.9 and 1.2 mm and the hook end 108 is a blunt tip with a diameter of 0.4-0.6 mm. In the illustrated implementation, the hook-shaped tip has a linear length of approximately 45 mm and tapers from a point nearer the handle end than the tip end to a point nearer the tip end than the handle end. In certain implementations, the taper maybe be continuous along the length of the hook-shaped tip. In one implementation, the tip is made of high-impact polystyrene and is sufficiently rigid to maintain its shape while manipulated by a user to thread the floss through braces and other orthodontic appliances. In the illustrated implementation, the length of dental floss 104 is attached within the hook-shaped tip by heating to weld the nylon dental floss to the polystyrene material. In other implementations, the dental floss is attached using adhesives within the cylindrical aperture in the handle end of the hook-shaped tip. The dental floss, in the illustrated implementation, is shred-resistant and waxed to facilitate threading of the dental floss between teeth. Because the dental floss is attached internally within the hook-shaped tip, there are no dimensional discontinuities along the surface of the dental-hygiene tool that could catch or become entangled with orthodontic-appliance components, such as wires and brackets.
[0010] In alternative embodiments, the hook-shaped tip may be hollow, with dental floss running through the hook-shaped tip and out from the tip end 108 . In this implementation, the hook-shaped tip may be advanced along a long stretch of dental floss and excess floss emerging from the tip end can be cut, thus allowing the tip to be continued to be used as worn or soiled dental floss is advanced through the tip and removed in order to a provide a new, fresh stretch of dental floss emerging from the handle end 106 . In this implementation, the dental floss is held in place by a secure constriction at the tip end of the hook-shape tip. In yet additional implementations, the hook-shaped tip and dental floss are formed of a continuous material that is differentially molded and/or treated to provide the hook-shaped semi-rigid tip and a trailing, flexible strand of dental floss. In certain implementations, the dental floss is treated with additional substances to confer various desirable properties to the dental floss, including antibacterial properties. In alternative implementations, the hook-shaped tip may have non-circular cross-sections, such as ellipsoid, rectangular, and other cross-section shapes. Similarly, the internal chamber within the hook-shaped tip may have correspondingly differently shaped walls. In these alternative implementations, the term “diameter” refers to a largest dimension perpendicular to the hook-shaped lengthwise axis of the hook-shaped tip.
[0011] FIGS. 2A-E illustrate an example use of the dental-hygiene tool to which the current document is directed. All five figures use the same illustration conventions, next described with reference to FIG. 2A . In FIG. 2A , a row of teeth 202 is shown, to which an orthodontic brace 204 has been attached. The orthodontic brace 204 includes brackets attached to the face of each tooth, such as bracket 206 , and a wire 208 that is slotted through the brackets under tension in order to apply force to the teeth. The dental-hygiene tool to which the current document is directed 210 has been positioned by a user in front of the wire 208 with the tip end 108 resting against the surface of tooth 212 . As shown in FIG. 2B , the dental-hygiene tool 210 has been lowered so that the tip end 108 is now positioned below and underneath the wire 208 . As shown in FIG. 2C , the hook-shaped tip 102 of the dental-hygiene tool 210 has been rotated upward so that the tip end 108 is now pointed upward and is above the wire 208 . As shown in FIG. 2D , the hook-shaped tip 102 of the dental-hygiene tool 210 has been pulled downward to thread the dental floss 104 underneath the wire 208 . Finally, as shown in FIG. 2E , the user has now grasped the dental floss with two hands (not shown in FIG. 2E ) above and below the wire to pull the dental floss 104 taut and to begin threading the dental floss between tooth 212 and tooth 214 in order to clean the edges of these two teeth and the space between the two teeth at the gum line.
[0012] The example manipulation shown in FIGS. 2A-E is but one possible use of the dental-hygiene tool disclosed in the current document. For example, the hook-shaped tip may be alternatively positioned handle-end upward and then rotated downward in order to thread the dental floss upward, below the wire. Many other operations are possible. The various possible operations and manipulations are facilitated by the semi-rigid nature of the hook-shaped tip as well as by the compact, hook-shaped configuration of the hook-shaped tip, allowing large-angle rotations with respect to the teeth and wire without forcing the tip into the teeth or gums. A flaccid, soft tip that does not hold its shape during manipulations would not provide a user with the ability to accurately position and pull the dental hygiene tool through and around spaces between the wire and teeth. Long, needle-like devices cannot be rotated around small components of orthodontic appliances in order to position floss behind them.
[0013] FIG. 3 illustrates certain of the dimensions of one implementation of the hook-shaped tip of the currently disclosed dental-hygiene tool. The hook-shaped tip 102 has a handle end 106 with a diameter of one millimeter and a hook end 108 having a diameter of 0.5 millimeters. The distance between the hook end 108 and the handle end 106 is, in this implementation, 17 mm 302 , and may vary from 15 to 19 mm in certain alternative implementations. In the various implementations, the hook-shaped tip has a linear length of between 35 and 55 mm.
[0014] Although the present invention has been described in terms of particular embodiments, it is not intended that the invention be limited to these embodiments. Modifications within the spirit of the invention will be apparent to those skilled in the art. For example, any of many different plastic polymers, flexible but semi-rigid metals, or composite materials can be used for the hook-shaped tip in alternative implementations. The dimensions, curvature, and shape of the hook-shaped tip may be varied in order to provide optimal usability for a variety of different types of users and a variety of different types of orthodontic appliances and fixtures.
[0015] It is appreciated that the previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. | The current document is directed to a dental-hygiene tool to facilitate flossing of teeth, particularly for orthodontics patients wearing braces or other orthodontic devices, fixtures, and appliances that hinder use of standard dental floss. The currently disclosed dental-hygiene tool includes a hook-shaped tip to which a length of dental floss is attached. The hook-shaped tip has a blunt tip to prevent gum injuries during use and is sufficiently rigid to facilitate navigation through orthodontics fixtures and appliances, including braces. | 0 |
BACKGROUND
The present invention relates to structural supports and more particularly to a supporting anchor for a mobile building structure.
Mobile building structures such as mobile homes are commonly utilized to provide living facilities which can be moved from place to place. Conventional construction provides a housing or body having a floor that is rigidly attached to a frame structure that usually includes flanged frame members such as I-beams. Typically, the frame structure is supported at a designed location on a plurality of stands or pylons that support the frame members. In order to provide stability in storms and other disturbances, various schemes have been utilized for anchoring the pylons to the ground, and for attachment to the frame member. However, the mobile building anchors or the prior art generally exhibit one or more of the following disadvantages:
1. They require holes to be drilled in the frame structure for receiving connecting fasteners, undesirably adding to the cost of installation, and undesirably weakening the structure.
2. They are ineffective for resisting the large forces having any directional orientation as required by resent and expected legislation. This is because existing clamping devices for connecting pylons to the frame members have limited resistance to longitudinal movement of the frame members.
3. They are unsuitable for use with frame structures having a variety of flange widths. Generally, were there are provisions for variant flange widths, the attachment to the frame member is ineffective for resisting relative movement in both the longitudinal and lateral directions relative to the frame members.
Thus there is a need for a mobile home anchor that is effective in withstanding forces having any directional orientation, that accommodates a variety of frame structure configurations and sizes, which is inexpensive and easy to install.
SUMMARY
The present invention is directed to a mobile home anchor apparatus and method that meets this need. The apparatus includes a support member for contacting a flanged frame member of a mobile building structure, means for anchoring the support member, a bladed clamp member, and fastener means for securing the clamp member to the support member, the blade member being adapted for locally deforming a flange member of the frame along a line intersecting a side edge of the flange member in response to tightening of the fastener means for preventing relative movement between the frame member and the support member. Preferably the apparatus includes stop means on the support member for preventing movement of the frame member in a first direction perpendicular to flange side edge relative to the support member and the clamp member together with the fastener means is adapted for preventing relative movement in a opposite direction relative to the support member. The blade member can be oriented perpendicular to the side edge.
The flange member of the frame member can include first and second flange portions extending on opposite sides of a web member, the blade member contacting the first blade portion, the stop means preferably being adapted for receiving the second flange portion and holding it against the supporting surface of the support member. The stop means can include a stop member extending upwardly from the supporting surface and forming an acute angle therewith for receiving the second flange portion.
Preferably the blade member is heat treated to an elevated hardness for penetrating into structural steel. Preferably the clamp member comprises two of the blade members for enhanced resistance to relative movement of the frame member. The blade members can be formed at opposite ends of the clamp member, the blade members preferably overhanging the supporting surface of the support member for permitting the clamp member to be tightened against the supporting surface in the absence of the frame member without the blade member contacting the support member, there by facilitating handling and storage of the apparatus with out damage to the blade members.
Preferably apex bisectors of the blade members are inclined relative to the supporting surface, intersecting above the supporting surface for enhanced resistance to relative movement between the frame member and the support member. More preferably, respective outside blade surfaces are inclined outwardly and downwardly to respective blade apexes for promoting further penetration by at least one of the blade members in response to an applied force in a direction parallel to the first side edge.
A bisector of an included angle between the blade members in the plane of the supporting surface is preferably perpendicular to the first edge of the flange member for equal resistance to applied forces in opposite directions along the first edge.
When the apparatus is to be used with frame members having variant flange widths, the invention includes means for selectively locating the clamp member in a plurality of discrete positions relative to the support member. The discrete positions for the clamp member advantageously enhance the resistance of the apparatus to forces perpendicular to the first edge of the flange member. Preferably the fastener means includes a pair of spaced apart fastener members that protrude the support member and the clamp members, the means for locating including a pair of first engagement means on one of the clamp member and the support member and a plurality of pairs of second engagement means on the other member, the fastener members engaging the first engagement means and a selected pair of the second engaging means corresponding to the selected discrete position of the clamp member. The second engaging means can include three pair of clearance holes in the support member
The means for securing the support member can include a threaded member extending rigidly from the support member. Also, a pylon having an anchorable base and a tubular collar rigidly spaced above the base and inclosing a portion of the threaded member to effect a rigid adjustable connection of the support member to the pylon structure.
The present invention also includes a method for anchoring a mobile building structure having a body member rigidly supported on a frame member, the frame member having a flange member extending therefrom and spaced from the body member, the flange member having a first side edge, the method comprising the steps of:
(a) providing a support member having a supporting surface;
(b) anchoring the support member with the supporting surface in contact with the flange member;
(c) providing a clamp member having a blade member; and
(d) tightly fastening the clamp member to the support member with the flange member between the blade member and the supporting surface,
whereby the blade member penetrates into the flange member along a line intersecting the first side edge for preventing relative movement between the frame member and the support member.
DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings where:
FIG. 1 is a fragmentary sectional elevational perspective view of apparatus according to the present invention in use supporting a mobile building;
FIG. 2 is a fragmentary sectional elevational view of the of FIG. 1 on line 2--2 of FIG. 1;
FIG. 3 is a fragmentary sectional elevational view of the FIG. 1 on line 3--3 of FIG. 1; and
FIG. 4 is a fragmentary plan view of the apparatus of FIG. 1 line 4--4 of FIG. 2.
DESCRIPTION
The present invention is directed to an anchor apparatus for mobile building structures that is intended to withstand forces in any direction. With reference to the drawings, and FIGS. 1-3 in particular, a building structure 2 has a housing or body 3 and a rigidly attached floor-supporting frame 4 that includes a spaced plurality of longitudinal frame members 5. Each frame member 5 includes a vertically extending web member 6 and a horizontally extending flange member 7 in spaced relation to the body 3. According to the present invention, an anchor apparatus 10 includes a support member 12 having a supporting surface 14 for contacting and supporting the frame member 5 of the structure 2. A threaded post member 16 is rigidly connected to the support member 12, extending downwardly and protruding a tubular collar 18 of an anchoring pylon 20. The pylon 20 has a polygonal base 22 including a perforate mounting member 24 for receiving an anchor member 26 that can be driven into the ground or otherwise connected to a concrete or timber foundation in a conventional manner. A plurality of legs 30 rigidly connect corners of the base 22 to the tubular collar 18. A pair of lock nuts 32 on the post member 16 effect a rigid and adjustable connection to the pylon 20, a tubular spacer 34 being selectively positioned above or below the collar 18 for extending the range of vertical adjustment of the support member 12.
A clamp member 40 is connected to the support member 12 by a pair of threaded fasteners 42 for clamping a first flange portion 44 of the flange member 7, the first flange portion 44 extending from the web member 6 to a first side edge 46 of the flange member 7. The clamp member 40 forms a Z-shaped cross section, a head portion 48 thereof extending over the first flange portion 44 and a foot portion 50 extending from proximate the first side edge to a line of contact 52 with the support member 12. The fasteners 42 protrude the support member 12 and the foot portion 50 of the clamp member 40. As shown in FIG. 3, the fasteners 42 are configured as hex head cap screws extending downwardly through a pair of clearance holes 54 in the clamp member 40 and another pair of clearance holes 55 in the support member 12, engaging respective nuts 58 below the support member 12. As best shown in FIG. 2, there are three pairs of the clearance holes 55 in the support member 12 for selectively locating the clamp member 40 as further described below. Also, and as best shown in FIG. 1, the fasteners 42 are locked from rotation by engagement of a head flat 56 of the fastener 42 with a web portion 57 of the clamp member 40. The web portion 57 is configured to provide a vertical offset between the head portion 48 and the foot portion 50 of the clamp member 40, the offset being less than a flange thickness of the frame member 5.
An important feature of the present invention is a pair of blade members 60 that are formed in the head portion 48 at opposite ends of the clamp member 40, the blade members 60 being adapted for locally deforming the flange member 7 along lines 62 that intersect the first side edge 46 of the flange member 7. The blade members 60 are hardened by local heat treatment of the clamp member 40 to an elevated hardness for facilitating penetration of the blade members 60 into structural steel forming the frame member 5, as the fasteners 42 are tightened. The local deformation along the lines 62 advantageously prevents relative movement between the frame member 5 and the support member 12 in opposite directions parallel to the first side edge 46, designated direction x in the drawings.
Regarding other possible directions of relative movement, the support member 12 itself prevents relative movement of the frame member 5 in a direction toward the supporting surface 14. The clamp member 40, being tightly connected to the support member 12 by the fasteners 42, prevents movement of the frame member 5 in a z direction away from the supporting surface 14. Also, the clamp member 40, and the blade members 60 in particular, being inclined relative to the supporting surface, form a wedge-shaped slot 64 that prevents movement of the frame member 5 in a y direction toward the fasteners 42. The effectiveness of this combination is enhanced by the inclination of the blade members 60 and the extension of the blade members 60 from the first flange portion 44 beyond the first side edge 46. Thus the deepest penetration of the blade members 60 is at the first edge 46, the penetration becoming shallower toward the blade web member 6 along the lines of contact 62. Moreover, any such movement of the frame member 5 in the y direction would produce an even deeper penetration by the blade members 60.
A stop member 70 is formed in the support member 12 at a location opposite the web member 6 from the fasteners 42, the stop member 70 receiving a second flange portion 72 of the flange member 7. As further shown in FIG. 2, the stop member 70 is curved upwardly from the supporting surface 14, extending upwardly and toward the web member 6 at an acute angle A from the supporting surface for holding the second flange portion 72 as well as for preventing relative movement of the frame member 5 on the support member 12 in the y direction away from the fastener 42.
Preferably each of the blade members 60 is oriented for producing its line of contact 62 with the first flange portion 44 in a direction perpendicular to the first side edge for enhanced resistance to relative movement in the x direction. Alternatively, the blade member 60 can be oriented at an angle B from a perpendicular to the first side edge 46 as shown in FIG. 4. Preferably the angle B is the same for each blade member 60 such that a bisector of the lines of contact 62 is perpendicular to the first side edge 46. Thus the apparatus 10 provides symmetrical resistance to relative movement in the opposite x directions with the blade member 60 having a symmetrical preferred cross-sectional configuration described below.
With particular reference to FIG. 3, the blade members 60 preferably each extend in the x direction to an apex 74 that is located outwardly from a corresponding portion of the supporting surface 14 for preventing contact with the support member 12 during handling of the apparatus 10 prior to its installation. Also, the apex 74 of each blade member 60 is formed at the intersection of an outside blade surface 76 and an inside blade surface 78, the apex 74 having an angle V, bisectors 80 of the angles V intersecting above the supporting surface 14, sloping downwardly and outwardly for producing increased compressive loading in one of the blade member 60 in response to an applied force of the frame member 5 in the x direction relative to the apparatus 10. The increased compressive loading of the blade member 60 advantageously improves the engagement of the blade member 60 with the permanently deformed material of the first flange portion 44 along the line contact 62, and enhances the resistance of the blade member 60 to permanent deformation or fracture in bending. More preferably, the outside blade surfaces 76 also slope downwardly and outwardly toward the respective apexes 74 for urging the blade member 60 to bite further into the first flange portion 44 in response to loading of the frame member 5 in the X direction relative to the support member 12. As also shown in FIG. 3, the fasteners 42 are spaced apart, being located proximate opposite ends of the clamp member 40. Thus the fasteners 42 are effective in preventing rotation of the clamp member 40 relative to the support 12 in the plane of the supporting surface 14. This further enhances the resistance of the apparatus 10 to forces in the x direction.
The blade embers 60 of the clamp member 40 are preferably roughly shaped by a stamping or shearing operation that forms the inside blade surfaces 78. Then, the sloping outside blade surfaces 76 are preferably formed by grinding.
As best shown in FIG. 2, the pairs of clearance holes 55 in the support member 12 provide three discrete positions for the clamp member 40 relative to the support member 12 for use of the apparatus 10 with flange members 5 having a variety of widths W of the flange member 7. For this purpose, the blade members 60 extend a distance D across a full width of the head portion 48 of the clamp member 40. Also, the pairs of clearance holes 55 are spaced in the y direction by a distance E, the distance E being less than the distance D.
The combination of the bladed clamp member 40, the fasteners 42, and the support member 12 of the present invention provides a high degree of resistance to loading, especially in the x direction, but without requiring drilling or other machining of the frame member 5, which would be undesirable for the reasons described above. The apparatus 10 also provides an effective restraint against loading in the other directions, even for frame member 5 of the differing cross-sectional configurations, because of the advantageous combination of the stop member 70, the sloping members 60 that permanently deform the first flange portion 44 of the frame member 5 along the lines of contact 62 intersecting the first side edge 46, and the spaced apart fasteners 42 that selectively engage pairs of the clearance holes 55 in the support member 12.
Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not necessarily be limited to the description of the preferred versions contained herein. | A mobile home anchor apparatus that withstands high wind loading and other forces in any direction includes a pylon-mounted support member for supporting a frame flange of a mobile building structure. The support member has a bladed clamped member that permanently deforms a flange portion of the frame when it it tightened against the support member, and a stop member that receives an opposite side portion of the flange. The clamp member is mountable in selected locations on the support member for accommodating variant flange widths of the frame, blade members of the clamp member extending in sloped relation to the support member across an edge of the first flange portion. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to an image display apparatus for a liquid crystal television receiver using a liquid crystal display panel.
Recently, portable liquid crystal television receivers using a liquid crystal display panel have been replacing CRTs in practical use. In Japanese television broadcasting the NTSC system is adopted. In the NTSC system, one vertical scanning period or one field has 262.5 horizontal scanning lines. On the other hand, a liquid crystal display panel having 120 by 160 picture elements has 120 scanning side electrodes, which correspond in number to substantially one half the number of effective horizontal scanning lines in one field of the video signal in the prior art. This means that the scanning side electrodes are driven for display each for every two horizontal scanning periods. In a liquid crystal television receiver using a liquid crystal display panel, one back plate period for a liquid crystal display panel corresponds to two horizontal scanning periods in the video signal. With the prior art liquid crystal television receiver, a video signal for only one horizontal scanning period is sampled during one back plate period, i.e., the sampled data is used for display for one back plate period. That is, with the prior art liquid crystal television receiver only substantially one half of the video signal of the ordinary television receiver can be obtained in the same horizontal scanning period. Therefore, even if the sampled video signal for a horizontal scanning period contains noise, it is displayed as such for one back plate period. In addition, even if adjacent video signals in one back plate period are considerably different, only one of them is used, leading to deterioration of the image display quality.
Further, in a prior art liquid crystal television receiver where signal electrode side register and driver circuit have n-bit structures, an n-bit television signal is received for display in 2 n gradations. Therefore, if the number of bits is insufficient, the number of gradations is also insufficient, so that fine intermediate tones of color cannot be sufficiently displayed. To increase the number of gradations, it is necessary to increase the number of bits, thus leading to complication of the circuit construction.
SUMMARY OF THE INVENTION
An object of the invention is to provide an image display apparatus, which can obviate the above drawbacks and permits the number of gradations to be increased without complicating the circuit construction while permitting simplification of the driver circuit in case when the number of gradations is not increased.
To attain the above object of the invention, there is provided an image display apparatus with a liquid crystal display panel, which comprises A/D conversion means for sampling a television signal a plurality of times in a horizontal effective display period and converting the sampled television signal into digital data consisting of a predetermined number of bits, data control circuit means for receiving a data control signal with the signal level thereof changed for each back plate period in the liquid crystal display panel corresponding to a plurality of horizontal scanning lines and digital data obtained from the A/D converter and for providing data consisting of a smaller number of bits than the bit number of digital data every time the level of said data control signal changes, means for generating a gradation signal in each back plate period according to data provided a plurality of times in one back plate period from the data control circuit means, and means for driving the liquid crystal display panel according to the gradation signal generated by the gradation signal generating means.
With the image display apparatus having the above construction according to the invention, a gradation signal is synthesized in one back plate period, or a new gradation signal is synthesized for two consecutive fields. Thus, it is possible to realize a gradation display similar to the case where there is one more bit than the bits constituting the signal electrode side driver circuit system.
It is thus possible to increase the number of gradations without complicating the circuit construction or, in case when the number of gradations is not increased, simplify the driver circuit. For example, where the segment side shift register and latch circuit individually have 160 stages, a reduction of a 4-bit gradation signal to 3 bits leads to a saving of 320 bits, which is very useful.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing an embodiment of the image display apparatus according to the invention;
FIG. 2 is a circuit diagram showing a specific circuit construction of a data control circuit shown in FIG. 1;
FIG. 3 is a view showing the relation between input data to and output data from the data control circuit;
FIG. 4 is a timing chart for explaining the operation of the circuit shown in FIG. 1;
FIG. 5 is a waveform chart showing gradation signals generated in the circuit shown in FIG. 1;
FIG. 6 is a block diagram showing a different embodiment of the image display apparatus according to the invention;
FIG. 7 is a timing chart for explaining the operation of the circuit shown in FIG. 6;
FIG. 8 is a waveform chart showing gradation signals generated in the circuit shown in FIG. 6;
FIG. 9 is a block diagram showing a further embodiment of the image display apparatus according to the invention;
FIG. 10 is a schematic representation of a specific circuit construction of an A/D converter shown in FIG. 9;
FIG. 11 is a view showing the relation between input data to and output data from the A/D converter shown in FIG. 10;
FIG. 12 is a timing chart for explaining the operation of the circuit shown in FIG. 10;
FIG. 13 is a waveform chart showing gradation signals generated in the circuit shown in FIG. 10;
FIG. 14 is a block diagram showing a further embodiment of the image display apparatus according to the invention;
FIG. 15 is a timing chart for explaining the operation of the circuit shown in FIG. 14; and
FIG. 16 is a waveform chart showing gradation signals generated in the circuit shown in FIG. 14.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, a first embodiment of the invention will be described in detail with reference to FIGS. 1 to 5. Referring to FIG. 1, there is shown an embodiment of the invention applied to a liquid crystal television receiver having 120 by 150 picture elements. In the illustrated image display system, a sync separator 1 separates horizontal and vertical sync signals from a video signal supplied from a prestage video amplifier (not shown) and feeds the separated sync signals to a synchronization control circuit 2. An A/D (analog-to-digital) converter 3 converts the video signal from the video amplifier noted above into a 4-bit digital signal 0 1 -O 4 to be fed to a data control circuit 4. The synchronization control circuit 2 generates various timing signals as shown in FIG. 4 according to the sync signals separated in the sync separator 1, the timing signals being fed to a segment side shift register 5, a latch circuit 6, a gradation signal generator 7, a segment side analog multiplexer 8, a common side shift register 9 and a common side analog multiplexer 10. The synchronization control circuit 2 further generates a data control signal E which is a digital signal fed to the data control circuit 4. The data control circuit 4 generates a 3-bit signal D 1 -D 3 fed to the segment side shift register 5 according to the 4-bit data from the A/D converter 3 and data control signal E from the synchronization control circuit 2, as will be described later in detail. The shift registers 5 has a structure of 3 bits by 60 stages. It reads out the 3-bit data D 1 -D 3 from the data control circuit 4 in synchronism to a chip enable signal CE and a clock signal φ 1 from the synchronization control circuit 2, the read-out data being fed to the latch circuit 6. The latch circuit 6 has a structure consisting of 3 bits by 160 stages. It reads out input data in synchronism to a latch signal φ ny from the synchronization control circuit 2, the read-out data being fed to the gradation signal generator 7. The gradation signal generator 7 operates in synchronism to the clock signal φ ny and a timing signal φ c from the synchronization control circuit 2 to generate a gradation signal according to the latch data in the latch circuit 6, the gradation signal being fed to the segment side analog multiplexer 8. To the multiplexer 8 are fed drive voltages V 0 , V 2 , V 3 and V 5 from a liquid crystal drive voltage generator 11 and also a frame signal φ f from the synchronization control circuit 2. The multiplexer 8 generates a liquid crystal drive voltage according to the gradation signal and frame signal φ f noted above to drive segment electrodes of a liquid crystal display panel 12 having 120 by 160 picture elements. The common side shift register 9 has a structure of 1 bit by 120 stages. It reads out a signal D x from the synchronization control circuit 2 according to a timing signal φ nx and shifts the read-out signal. The output of the common side shift register 9 is fed to the common side analog multiplexer 10. Of the liquid crystal drive voltages V 0 to V 5 generated by the liquid crystal drive voltage generator 11, the voltages V 0 , V 1 , V 4 and V 5 are fed to the multiplexer 10, and the voltages V 0 , V 2 , V 3 and V 5 are fed to the multiplexer 8. The multiplexer 10 drives common electrodes of the liquid crystal display panel 12 according to the data from the shift register 9.
The data control circuit 4 will now be described in detail with reference to FIG. 2. The data control circuit 4 includes NAND gates 21 to 23, an inverter 24, a NOR gate 25, exclusive-NOR gates (hereinafter referred to as EX-NOR gates) 26 and 27 and an exclusive-OR gate (hereinafter referred to as EX-OR gate) 28. Of the 4-bit data O 1 to O 4 provided from the A/D converter 3, the data O 1 is fed to the NAND gate 21 and EX-NOR gate 26, the data O 2 is fed to the NAND gates 21 and 22 and EX-OR gate 28, the data O 3 is fed to the NAND gate 21, inverter 24 and EX-NOR gate 27, and the data O 4 is fed to the NAND gate 23. To the NAND gate 23 are also fed the output of the NAND gate 21 and data control signal E from the synchronization control circuit 2, and the output signal of the NAND gate 21 is fed to the EX-NOR gate 27. The output of the NAND gate 23 and the output of the inverter 24 are fed through the NOR gate 25 to the EX-OR gate 28 and NAND gate 22. The output of the NAND gate 22 is fed to the EX-NOR gate 26. The outputs of the EX-NOR gate 26, EX-OR gate 28 and EX-NOR gate 27 are fed as the 3-bit data D 1 -D 3 to the segment side shift register 5. The data control signal E has a level which is alternately inverted to "1" and "O" in synchronism to the timing signal φ ny as shown in FIG. 4. The signal E changes the output data D 1 to D 3 of the data control circuit 4 to two different values. More specifically, the data control circuit 4 provides data D 1 -D 3 of two different values as the data control signal E is inverted to "0" or "1" according to the data O 1 -O 4 from the A/D converter 3 as shown in FIG. 3.
The operation of the embodiment having the above construction will now be described. The synchronization control circuit 2 feeds the signal to the common side shift register 9 for one back plate period in synchronism to the vertical sync signal, as shown in FIG. 4. The signal D x is read into the common side shift register 9 according to the clock φ nx provided from the synchronization control circuit 2 for every back plate period, and is shifted through the shift register 9. The shift register 9 feeds successive signals X1, X2, . . . each having one back plate duration F as shown in FIG. 4 to the common side analog multiplexer 10. The multiplexer 10 feeds the liquid crystal drive signals V 0 , V 1 , V 4 and V 5 to the liquid crystal display panel 12 according to the signal from the shift register 9 for driving the common electrodes. More specifically, the signal X1 selects the corresponding common electrode for one back plate period a1, the signal X2 selects the corresponding common electrode for the next back plate period a2, and so forth. The multiplexer 10 inverts the liquid crystal drive signal in synchronism to the frame signal.
Meanwhile, A/D converter 3 samples the video signal supplied from the video amplifier in individual horizontal scanning periods d1, d2, . . . as shown in FIG. 4 for conversion to the 4-bit digital signal O 1 -O 4 fed to the data control circuit 4. The data control circuit 4 provides the 3-bit data D 1 -D 3 according to the signal O 1 -O 4 from the A/D converter 3 and data control signal E from the synchronization control circuit 2. More specifically, the data control circuit 4 provides data D 1 to D 3 corresponding to the data O 1 to O 4 from the A/D converter 3 as different values when the data control signal E is E=0 and E=1, respectively, as shown in FIG. 3. The level of the data control signal E is inverted in synchronism to the latch signal φ ny as shown in FIG. 4. For example, the data control signal E is "O" for the first half b of one back plate period and is "1" for the second half c of the period. The data D 1 -D 3 from the data control circuit 4 is fed to the segment shift register 5. When the chip enable signal CE is provided from the synchronization control circuit 2, the shift register 5 reads out the data D 1 -D 3 from the A/D converter 3 in synchronism to the clock φ 1 . When data has been read into all the bits of the shift register 5, the synchronization control circuit 2 produces a latch pulse φ ny , causing the data in the shift register 5 to be latched in the latch circuit 6 to be fed to the gradation signal generator 7. The gradation signal generator 7 counts the clock signal φ c according to the data from the latch circuit 6 to produce the gradation signal fed to the multiplexer 8. The multiplexer 8 feeds the liquid crystal drive signals V 0 , V 2 , V 3 and V 5 to the liquid crystal display panel 12 according to the gradation signal from the gradation signal generator 7 for driving the segment electrodes. At this time, the multiplexer 8 inverts the liquid crystal drive signals V 0 , V 2 , V 3 and V 5 in synchronism to the frame signal φ f for dynamically driving the liquid crystal display panel 12. While the gradation signal for driving the liquid crystal display panel 12 is produced according to the data provided from the data control circuit 4 in the manner as described above, the data control circuit 4 performs different operations according to the data control signal E. Thus, even if entirely the same data is provided from the A/D converter 3 for the first and second halves of one back plate period, the data control circuit 4 produces different data for the first and second halves of the back plate period according to the data control signal E as shown in FIG. 3. The output level of the data control circuit 4 is thus switched for every horizontal scanning period according to the data control signal E. More specifically, when the data control signal E is at "O" level, the upper three bits of the input data O 1 to O 4 are provided as data D 1 to D 3 from the data control circuit 4 to be used for the display for one horizontal scanning period. In the horizontal scanning period, the data control signal E is at "1" level. In this case, if the least significant bit O 4 of the output data O 1 to O 4 of the A/D converter 3 is "O", the upper three bits are provided as data D 1 to D 3 from the data control circuit 4. If the least significant bit O 4 is "1", "1" is added to the upper three bits, and the resultant data is provided as data D 1 to D 3 .
Therefore, the gradation signal generator 7 provides different gradation signals for the first and second halves b and c of one back plate period as shown in FIG. 5. FIG. 5 shows waveforms of gradation signals "O" to "15". In the liquid crystal display panel 12, the same common electrode is scanned during one back plate period noted above. The gradation signal provided from the generation signal generator 7 thus has a single gradation level for both the first and second halves b and c of one back plate period as shown in FIG. 5. The video data for each horizontal scanning line can be regarded to be the same for the first and second periods b and c of one back plate period, so that it is possible to control sixteen different gradations "O" to "15" according to the 3-bit data D 1 -D 3 provided from the data control circuit 4.
In the embodiment of FIG. 1 shown above, the data D 1 to D 3 have been controlled according to the data control signal E provided from the synchronization control circuit 2 to the data control circuit 4.
FIGS. 6 to 8 illustrate a different embodiment. In this instance, a frame signal φ f provided from a synchronization control circuit 2 is provided as a data control signal to a data control circuit 4, while the synchronization control circuit 2 feeds a timing signal φ n to a latch circuit 6, a gradation signal generator 7 and a common side shift register 9. The timing signal φ n consists of pulses each provided for every other horizontal sync signal as shown in FIG. 7, and it corresponds to the timing signal φ nx shown in FIG. 1. A chip enable signal CE also consists of pulses each provided for every other horizontal scanning line for selecting the video signal for every other horizontal scanning line. In FIG. 6, parts like those in FIG. 1 are designated by like reference numerals.
In the above structure, the A/D converter 3 converts the video signal supplied from the video amplifier into 4-bit digital data O 1 -O 4 to be fed to the data control circuit 4. Like the preceding embodiment, the data control circuit 4 converts the digital signal O 1 -O 4 provided from the data control circuit 4 into 3-bit data D 1 -D 3 according to the frame signal φ f from the synchronization control circuit 2. The data D 1 to D 3 provided from the data control circuit 4 are read into the segment side shift register 5 in synchronism to the chip enable signal CE and clock φ 1 . The data written in the shift register 5 is latched in the latch circuit 6 in synchronism to the timing signal φ n to be fed to the gradation signal generator 7. The gradation signal generator 7 generates a gradation signal corresponding to the data latched in the latch circuit 6 under the control of the timing signals φ n and φ c , the gradation signal thus produced being fed to the segment side analog multiplexer 8 for driving the liquid crystal display panel 12.
The output level of the data control circuit 4 is switched for very field according to the frame signal φ f . More specifically, when the frame signal φ f is at "O" level, the upper three bits of the input data O 1 to O 4 are fed as data D 1 to D 3 to the data control circuit 4 to be used for the display for one field. In the next field, the frame signal φ f is at "1" level. In this case, if the least significant bit O of the output data O 1 to O 4 of the A/D converter 3 is "O", the upper three bits are provided as data D 1 to D 3 from the data control circuit 4. If the least significant bit O 4 is "1", "1" is added to the upper three bits, and the resultant data are provided as data D 1 to D 3 to the data control circuit 4.
The video signal of the individual horizontal scanning lines can be regarded to be the same for the two adjacent fields noted above. Thus, the shade is displayed for two fields F and G as a unit as shown in FIG. 8. That is, a signal of 4 bits in effect, i.e., 15 gradations can be provided although the data control circuit 4 provides a 3-bit signal, i.e., an 8-gradation signal.
FIG. 9 shows a further embodiment of the invention.
The circuit construction shown in FIG. 9 is the same as the circuit construction shown in FIG. 1 except that the data control circuit 4 in the circuit of FIG. 1 is omitted, the data control signal E from the synchronization control circuit 2 is fed to the A/D converter 3, and the output of the A/D converter 3 is fed to the segment side shift register 5. In FIG. 9, parts like those in FIG. 1 are designated by like reference numerals.
The A/D converter 3 in the circuit of FIG. 9 will now be described in detail with reference to FIG. 10. Referring to FIG. 10, the A/D converter includes a voltage divider 30 which includes series resistors r1 to r16 having an equal resistance. A reference voltage power supply 31 is connected across a series circuit consisting of the resistors r1 to r15 via gates 32a and 32b, and it is connected across a series circuit consisting of the resistors r2 to r16 via gates 33a and 33b. The gates 32a and 32b are gate controlled according to the data control signal E from the synchronization control circuit 2, and the gates 33a and 33b are gate controlled according to an inverted signal obtained for the data control signal E. The connection points between adjacent ones of the resistors r1 to r16 are each connected to a minus input terminal of each of comparators 34a to 34o. A video signal h from the video amplifier (not shown) is fed to a plus terminal of each of the comparators 34a to 34o. The comparators 34a to 34o compare respective division voltages obtained from the output voltage of the reference power supply 31 through the resistors r1 to r16 to the video signal h and provide the results to a decoder 35. The decoder decodes the outputs of the comparators 34a to 34o to recover the 3-bit data D 1 to D 3 which are fed to the segment side shift register 5. The level of the data control signal E is inverted alternately to "1" and "O" in synchronism to the timing signal φ ny as shown in FIG. 12, and the A/D converter 3 provides output data D 1 to D 3 as two different values according to the signal E. More specifically, depending on whether the data control signal E is "1" or "O", the series circuit of the resistors r1 to r15 or resistors r2 to r16 of the voltage divider is selected as shown in FIG. 11, whereby the bias voltage fed to the comparators 34a to 34o is varied to provide the two different values as the data D 1 to D 3 .
The operation of this embodiment will now be described. The synchronization control circuit 2 feeds a signal Dx to the common side shift register 9 in synchronism to the vertical sync signal for one back plate period as shown in FIG. 12. This signal Dx is read into the common side shift register 9 under the control of a clock φ nx provided for every back plate period, and it is shifted through the shift register 9. The shift register 9 thus feeds successive signals X1, X2, . . . each having a duration F of one back plate period as shown in FIG. 12 to the common side analog multiplexer 10. The multiplexer 10 feeds the liquid crystal drive signals V 0 , V 1 , V 4 and V 5 to the liquid crystal display panel 12 according to the signal from the shift register 9 for driving common electrodes. More specifically, the signal X1 selects the corresponding common electrode for a back plate period a1, the signal X2 selects the corresponding common electrode for the next back plate period a2, and so forth. The multiplexer 10 inverts the liquid crystal drive signal in synchronism to the frame signal φ f .
Meanwhile, the A/D converter 3 samples the video signal supplied from the video amplifier in successive horizontal scanning periods d1, d2, . . . for conversion to the 3-bit digital data D 1 to D 3 as shown in FIG. 12. The A/D converter 3 provides different data as the data D 1 to D 3 when the data control signal E is E=0 and E=1, respectively. The level of the data control signal E is inverted according to the latch clock φ ny as shown in FIG. 12. That is, the data control signal E is "O" and "1" for the respective first and second halves b and c of one back plate period. The data D 1 to D 3 provided from the A/D converter 3 are fed to the segment side shift register 5. The data D 1 to D 3 from the A/D converter 3 are read out into the shift register 5 in synchronism to the clock when a chip enable signal CE is provided from the synchronization control circuit 2. When the data has been read into all the bits of the shift register 5, the synchronization control circuit 2 produces a latch pulse φ ny , thus causing the data held in the shift register 5 to be latched in the latch circuit 6 and to be fed to the gradation signal generator 7. The gradation signal generator 7 generates a gradation signal by counting the clock φ c according to the data from the latch circuit 6, the gradation signal thus produced being fed to the multiplexer 8. The multiplexer 8 feeds the liquid crystal drive signals V 0 , V 2 , V 3 and V 5 to the liquid crystal display panel 12 according to the gradation signal from the gradation signal generator 7, whereby segment electrodes are driven for display. In this case, the multiplexer 8 inverts the liquid crystal drive signals V 0 , V 2 , V 3 and V 5 in synchronism to the frame signal φ f , thus dynamically driving the liquid crystal display panel 12. While the gradation signal is generated according to the data provided from the A/D converter 3 for driving the liquid crystal display panel 12, the A/D converter 3 performs different operations according to the data control signal E. Thus, even if entirely the same video signal is supplied for the first and second halves of one back plate period, the A/D converter 3 provides different data for the first and second half of the back plate period as shown in FIG. 11. That is, the output signal level of the A/C converter 3 is switched for every horizontal scanning period according to the data control signal E. More specifically, when the data control signal E is at "O" level, the gates 33a and 33b are held enabled, so that the voltage of the reference voltage power supply 31 is divided through the resistors r2 to r16 in the voltage divider 30 to obtain reference voltages fed to the comparators 34a to 34o. With the gates 33a and 33b enabled as shown above, a low level side voltage R L of the reference voltage power supply 31 is fed directly to the comparator 34o while a high level side voltage R H is fed through the resistor r16 to the comparator 34a. Thus, the reference voltages fed to the comparators 34a to 34o are switched to a low level side. When the data control signal E is at "1" level, the gates 32a and 32b are held enabled, so that the voltage of the reference voltage power supply 31 is divided through the resistors r1 to r15 of the voltage divider 30 to obtain reference voltages fed to the comparators 34a to 34o. With the gates 32a and 32b enabled as shown, the low level side voltage R L of the power supply 31 is fed through the resistor r1 to the comparator 34o while the high level side voltage R H is fed directly to the comparator 34a. The reference voltages fed to the comparators 34a to 34o are thus switched to the high level side. The result of comparison of the video signal h to the reference voltages, provided from the comparators 34a to 34o, is fed to the decoder 35 for decoding to produce the data D 1 to D 3 . That is, since the reference voltages of the comparators 34a to 34o are switched according to the level E of the data control signal E, the decoder 35 produces different data as the data D 1 to D 3 when the data control signal E is "O" and "1", respectively, as shown in FIG. 11.
The gradation signal generator 7 thus produces different gradation signals for the the first and second halves b and c of one back plate period as shown in FIG. 5.
FIG. 13 shows waveforms of gradation signals "O" to "15". In the liquid crystal display panel 12, the same common electrode is scanned during one back plate period. The gradation signal provided from the gradation signal generator 7 thus has a single gradation level for both the first and second halves b and c of one back plate period as shown in FIG. 13. The video data for each horizontal scanning line can be regarded to be the same for the first and second periods b and c of one back plate period, so that it is possible to control sixteen different gradations "O" to "15" according to the 3-bit data D 1 -D 3 provided from the A/D converter 3.
FIG. 14 shows a further embodiment of the invention. In this instance, a frame signal (which is inverted for every television field) provided from the synchronization circuit 2 is fed as a data control signal to the A/D converter 3, and the synchronization control circuit 2 feeds a timing signal φ n to the latch circuit 6, gradation signal generator 7 and common side shift register 9. The timing signal φ n consists of pulses each provided for every other horizontal sync pulse, and it corresponds to the timing signals φ nx shown in FIGS. 1 and 4. The chip enable signal CE is provided for every other horizontal scanning line to select the video signal for every other horizontal scanning line.
In the above structure, the A/D converter 3 converts the video signal supplied from the video amplifier into the 3-bit data D 1 to D 3 according to the frame signal φ f from the synchronization control circuit 2 as in the embodiment shown in FIG. 9. The data D 1 to D 3 provided from the A/D converter 3 are successively read into the segment side shift register 5 in synchronism to the chip enable signal CE and clock φ 1 . The data written in the shift register 5 is latched in the latch circuit 6 in synchronism to the timing signal φ n to be fed to the gradation signal generator 7. The gradation signal generator 7 generates a gradation signal corresponding to the data latched in the latch circuit 6 according to the timing signals φ n and φ c , the gradation signal thus produced being fed to the segment side analog multiplexer 8 for driving the liquid crystal display panel 12.
The output level of the A/D converter 3 is switched for every field according to the frame signal φ f . When the frame signal φ f is at "O" level, the gates 33a and 33b shown in FIG. 10 are held enabled. In this case, the reference voltages of the comparators 34a to 34o are on the low level side. The outputs of the comparators 34a to 34o at this time are decoded in the decoder 35 into the data D 1 to D 3 to be used for the display for one field. In the next field, the frame signal φ f is at "1" level. At this time, the gates 32a and 32b are held enabled, and the reference voltages of the comparators 34a to 34o are on the high level side. The outputs of the comparators 34a to 34o at this time are again decoded in the decoder 35 into the data D 1 to D 3 to be used for the display for one field.
The video signal of the individual horizontal scanning lines can be regarded to be the same for the two adjacent fields noted above. Thus, the shade is displayed for two fields F and G as a unit as shown in FIG. 16. That is, a signal of 4 bits in effect, i.e., 15 gradations, can be provided although the A/D converter 3 provides only the 3-bit data D 1 to D 3 , i.e., an 8-gradation signal.
The above embodiments are concerned with the NTSC system television receiver, but the invention is of course applicable to television receivers of other systems such as the PAL system and SECAM system as well. | An image display apparatus having an A/D converter which samples a television signal a plurality of times in each horizontal effective display period and converts the sampled signal into digital data, and a gradation signal generator combines gradation signals produced in a plurality of horizontal effective display periods according to the digital data to produce a new gradation signal. An image display panel is driven for display according to the new gradation signal. | 6 |
CLAIM OF BENEFIT OF FILING DATE
[0001] The present application claims the benefit of the filing date of U.S. Provisional Application Serial No. 60/334,228 filed Nov. 29, 2001.
TECHNICAL FIELD
[0002] The present invention relates to an apparatus and method for making Nigiri Sushi and other Sushi products. More particularly, the present invention provides a kit including an improved molding apparatus and method of making Nigiri, square, rectangular, pentagonal, hexagonal, etc., as well as any polygonal design as well as Maki or California Rolls.
BACKGROUND OF THE INVENTION
[0003] In the traditional production and preparation of sushi products, such as Nigiri and Maki Sushi (hereinafter referred to as “Sushi Rolls”), a significant amount of time and effort is required. Nigiri are small ball or oval shaped forms of vinegared boiled rice topped with sliced fish, shellfish or other traditional toppings. The art of Nigiri is in the formation of the rice ball and more particularly, the proper compression of the rice to hold its shape during consumption. Once the rice ball is formed, the topping is added. Production rate and uniformity of the Sushi Roll in restaurant or other food facility requires experience, training, and skill which are all dependent upon the experienced of the chef. The present invention addresses these potential disadvantages of traditional sushi products by providing a method, apparatus, and kit for forming high quality Nigiri Sushi and Sushi Rolls which could be utilized in household, domestic, restaurant, food service, and food production environments.
[0004] The Sushi Rolls are thin sheets of seaweed (nori) topped with a layer of vinegared boiled rice and a second layer of crab, fish, or vegetables or other traditional toppings. Traditionally, the nori, rice and toppings are then rolled by hand with a bamboo mat so as to tighten and consolidated the ingredients forming an elongate horizontal roll. The California Roll is then sliced vertically into smaller bite sized pieces. Like Nigiri, the art of the California Roll is forming a compact horizontal roll that will maintain its shape after cutting and during consumption. And like Nigiri, production rate and uniformity for environments such as a restaurant is generally slow even for the most experienced chef.
SUMMARY OF THE PRESENT INVENTION
[0005] The present invention provides a kit for producing a high quality sushi product with uniformity and at a high rate of production. The kit includes a Nigiri Sushi mold and a Sushi Roller apparatus. In a preferred embodiment, the kit may include a traditional Japanese bento box that houses both the Nigiri Sushi mold and the selected Sushi Roll. The Nigiri Sushi mold is made up of a mold having several indentations for supporting the preferred ingredients. Each indentation includes an opening at the lowest point or base of the indentation. The mold has rimmed upper area for receiving a plate. The plate is configured with funnels extending from a flat surface and an outer profile similar to the rimmed upper area of the mold. These funnels correspond to the indentations located on the lower mold. An elongated press is provided and is shaped at one end identical to the funnels of the plate and at the other end is shaped identical to the opening at the lowest point of the mold. The outer profiles of both ends of the press are slightly smaller than the openings intended for seating within the plate and mold.
[0006] To form Nigiri Sushi, the Nigiri mold is placed on a level surface. A preferred topping is first place within the indentations of the mold. This is opposite the traditional method wherein the topping is placed after the rice ball has been formed. Next, the plate is seated within the mold and Wasabi is applied through various means, such as a tube, followed by vinegared rice being placed within the funnels. The funnel end of the press is used to press and compact the rice into the funnel and the indentations of the mold. The press or push tool may also be utilized by the user to achieve a desired amount of texture, consistency, or compactness of the sushi product The press and the funnel plate are then removed from the top of the mold. The mold is then rotated or turned upside down by the user which then allows gravity to displace the sushi product from the mold when the mold comes into contact with a level surface, such as a counter, assembly line, or food service station. Any remaining sushi product in the mold can then be removed with a press or push tool or instrument. For example, the opposite end of the press is used to gently remove the newly formed Nigiri Sushi from the indentations in the mold by inserting the press end into the openings provided in the bottom of the mold indentations. The Nigiri Sushi may then be served in the bento box, a sushi plate, or any other type of serving platform. Since the rice ball is rotated 180 degrees, the topping is now correctly located on top of the rice ball as tradition dictates.
[0007] The apparatus used to form the Sushi Rolls sits atop an inverted Nigiri mold and includes a roller sheet comprising an integrated roller rod, a flexible sheet or material, such as silicone, and a stopper that is flexibly attached to a base plate. In a preferred embodiment, the roller is supported by the Nigiri mold inverted to form a level support surface. A rolling rod with a set of opposing handles may be removably attached to one end of the roller sheet. A stopper may be removably attached to the opposite end of the roller sheet and secures the roller sheet to the base plate.
[0008] The California Roll is made by placing a sheet of seaweed on the silicone roller sheet between the rolling rod and the stopper within the edges of the inverted Nigiri mold. A layer of vinegared rice is spread to cover the seaweed. A layer of filling is added on top of the rice and preferably is spaced from the rolling rod. To successfully form the California Roll, the handles of the rolling rod are grasped and move the roller sheet toward the stopper. The roller rod is lifted and turned so that the flat surface of the rod is facing the selected filling. The flat surface (roller slip) is pushed against the filling using a forward motion by the user to push and compact the filling. An example of the rolling method allows a user to effectively form sushi products through a “reverse roll” method or process whereby the user initially manipulates the silicone in a counter-clockwise direction and then manipulates the roller rod in a clockwise direction thereby forming and moving the sushi product along the base plate and toward the user. Although it will be appreciated that the desired manipulation can be either in a clockwise or counter-clockwise motion, it should be seen that the desired technique, method, or process forces the ingredients to roll up forming an elongated cylinder. At the end of this “reverse roll” process, the sushi product itself will generally come into contact with the stopper, thereby positioning the roller slightly below the stopper. If the user continues to manipulate the roller in a clockwise direction, the circumference of the silicone around the roll will decrease in size thus compacting or compressing the rice and other filling to form the desired texture, consistency, and compactness of the desired sushi product. When the cylinder reaches the stopper, the rolling rod is brought back to its original position by the user. Once compacted, the California Roll is removed from the roller sheet and cut vertically into serving size pieces. The Japanese bento box top or inverted bottom may be used as a serving plate.
[0009] These and other objects of the present invention will become apparent upon reading the following detailed description in combination with the accompanying drawings, which depict systems and components that can be used alone or in combination with each other in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 illustrates an exploded perspective of the present invention.
[0011] [0011]FIG. 2 illustrates a top view of an alternative embodiment of a mold of the present invention.
[0012] [0012]FIG. 3 illustrates a cross-sectional view of the mold in FIG. 2.
[0013] [0013]FIG. 4 illustrates a top view of an alternative embodiment of a plate of the present invention.
[0014] [0014]FIG. 5 illustrates a cross-sectional view of an alternative embodiment of a mold of the present invention.
[0015] [0015]FIG. 6 illustrates an elevational view of a preferred embodiment of a press of the present invention.
[0016] [0016]FIG. 7 illustrates a perspective view of a first preferred embodiment of a California Sushi Roll apparatus of the present invention.
[0017] FIGS. 8 - 11 illustrate a method for making a California Sushi Roll with a first preferred embodiment of the present invention.
[0018] FIGS. 12 - 13 illustrate a method for making Nigiri Sushi with a particularly preferred embodiment of a square-shaped Nigiri Sushi mold of the present invention.
[0019] [0019]FIG. 14 illustrates a perspective view of a preferred embodiment of a California Sushi Roll apparatus of the present invention.
[0020] [0020]FIG. 15 illustrates an exploded view of a kit including the Sushi apparatus of the present invention.
[0021] FIGS. 16 illustrates a particular preferred embodiment of the present invention consisting of an integrated roller unit having a generally rectangular shaped footplate.
[0022] [0022]FIG. 17 illustrates another view of the integrated roller unit of the present invention.
[0023] [0023]FIG. 18 illustrates yet another embodiment of the integrated roller unit depicting a half-moon shaped design.
DESCRIPTION OF THE INVENTION
[0024] Referring to FIGS. 1 - 6 , the present invention of a method and apparatus of preparing Nigiri Sushi is illustrated consisting of a Nigiri Sushi mold assembly 10 , for receiving rice, a selected portion of fish or other seafood item, vegetables, and selected seasonings (not shown.) It should be appreciated that the present invention can be utilized to form Sushi Rolls and other rolled food products using any type of food items or comestible materials selected by the user for human consumption. The Nigiri Sushi mold assembly 10 is configured with a mold 12 , a plate 14 , a press 16 , and, optionally, a box 18 with a removable lid 20 . In a first example of operation, box 18 would be used as storage unit for mold 12 , plate 14 and press 16 . In a second example of operation, a box 18 may be configured with regions configured to receive and serve the Nigiri Sushi.
[0025] Referring now to FIGS. 2 - 6 , mold 12 of the Nigiri Sushi mold 12 is configured with a flat surface 20 and is substantially circular in shape. Preferably mold 12 , will be further configured with a lip 22 having an inwardly projecting male key 24 , and a supporting leg 26 (FIG. 3) both residing on the outer circumference of mold 12 which project perpendicularly away from flat surface 20 . Flat surface 20 is configured with at least one and, more preferably, a plurality of indentations 28 extending radially from the center portion 30 of mold 12 . The indentations 28 are supported in part by supporting surface 32 and wall 34 which substantially surrounds both the indentations 28 and the supporting surface 32 . The indentations 28 are further configured with an elliptical hole 36 positioned substantially at the center of the indentations 28 , which is substantially smaller in both shape and dimension than the indentations 28 .
[0026] The number of indentations found in the assembly of the present invention would be consistent with the number and size of pieces or portions of individual Nigiri Sushi selected by the user to be served and consumed. However, it is foreseeable that the number of indentations, and orientation thereof, would vary at the point of sale or use and could further be configured in any number of sizing. For example, it is contemplated that the present invention could be commercialized as an individual serving size product, a family size product, a commercial size product for the large scale preparation of sushi such as in a restaurant, food service, or food manufacturing facility or any other size or shape that is desired by the consumer. Furthermore, it is foreseeable that the indentations found in the present invention may vary in size and shape as serving portions and comestible materials used to form the Sushi may vary according to taste, size of group, etc.
[0027] Referring to FIGS. 3 - 5 , a plate 14 is configured with a flat surface 38 having an outer circumference similar in size and shape to the inner surface 40 of lip 22 . Plate 14 is further configured with an inwardly recessed female key 42 for receiving male key 24 causing mold 12 and plate 14 to become aligned. Plate 14 is yet further configured with a plurality of funnels 44 which extend radially from the center portion 46 of plate 14 which are in alignment with indentations 28 . Opposing finger holes 49 are provided along the outer circumference to aid in removing the plate 14 from the top of the mold 12 after the Nigiri Sushi has been formed.
[0028] Referring specifically to FIGS. 3 and 5, when the plate 14 and mold 12 are in alignment and flush with each other, extending member 48 of funnel 44 partially resides in at least one of the indentations 28 . The shape and size of extending member 48 is substantially similar to that of the outer area of at least one of the indentations 28 .
[0029] The number of funnels 42 may be equal to that of the number of indentations 28 of the mold 12 . However, it is foreseeable the number of funnels 42 are more or less than the number of indentations 28 . This may be preferable when it is desired to create mold 12 and plate 14 configurations to obtain a specific number of servings.
[0030] Referring now to FIG. 6, other important features of the present invention include the use of a press 16 which is illustrated as having a first end 50 and a second end 52 . The first end 50 has a cross sectional shape substantially similar to that of the opening of funnel 44 such that the first end 50 can unobtrusively enter in and through funnel 44 and extending member 48 . The second end 52 has a cross sectional shape substantially similar to that of the elliptical hole 36 residing in the bottom of the indentations 28 such that the second end 52 can fit unobtrusively through elliptical hole 36 .
METHOD OF MAKING NIGIRI SUSHI OF THE PRESENT INVENTION
[0031] The present invention also comprises a method of making Nigiri Sushi utilizing the apparatus and device described above. In a preferred embodiment of the methodology employed for making Nigiri Sushi, a Nigiri Sushi mold assembly 10 is used to combine selected ingredients (e.g. a fish portion, a seafood portion, rice, vegetables, selected seasonings, as well as any other type of comestible material consumed by humans) as well as any other ingredient or combination of ingredients typically used in the making of Nigiri Sushi.
[0032] Referring to FIGS. 1 - 6 , the supporting leg 26 of the mold 12 is placed on a substantially flat surface such that the plurality of indentations 28 and elliptical hole 36 are fully exposed. The user then places the selected fish or seafood portion, typically found in Nigiri Sushi, in each of the indentations 28 of the mold and applies seasonings to the chosen portions. It is contemplated that the types of seafood or fish items that may be incorporated within Sushi, as well as the seasonings used in the making of Nigiri Sushi, are well known in the art and may vary between applications and the specific taste of the user or consumer. It may be desirous to omit all spices at this stage or only use spices at this stage depending upon taste or a customer's preferences.
[0033] A plate 14 is placed over mold 12 and aligned through keys 24 and 42 as previously discussed. The plate is then substantially seated into the opening created by lip 22 and onto the flat surface 20 of the mold 12 . This results in the funnels 44 of the plate 14 being aligned with the indentations 28 of the mold 12 .
[0034] Cooked rice is then placed within and partially through each of the funnels 44 and onto the fish portions residing in each of the indentations 28 . The rice is then packed further into the indentations 28 forming a semi-ball shaped mound. This is accomplished by inserting first end 50 of the press 16 through the funnel 44 opening and at least partially into the extending member 48 resulting in an applied force to the cooked rice. Once the rice residing in the indentations 28 is compressed to the desired amount the press 16 and plate 14 are removed from the open created by the lip 22 of mold 12 .
[0035] The box 18 , which is configured to additionally be a serving tray, is positioned such that the serving surface is placed on top of the cooked rice and mold 12 . The mold and box 18 are simultaneously turned over and the second end 52 of the press 16 is inserted into elliptical hole 36 to aid in gently removing the sushi from the mold 12 . The mold 12 is then lifted out of the box 18 thus presenting the final product of the Nigiri Sushi arranged in the box 18 . This process is then repeated until the desired amount of Nigiri Sushi is created.
[0036] In another embodiment of the Sushi Roll apparatus of the present invention, more fully shown and described in FIGS. 7 - 11 , a method and apparatus for molding and forming traditional sushi pieces, such as California Rolls is shown and described. More particularly, in this embodiment, a Sushi Roll Apparatus 54 is disclosed which utilizes a roller sheet 56 having an attached rod 58 with two ends or handles 60 used to physically roll and form the chosen food items into a piece of Sushi. In a particular preferred embodiment which has a number of manufacturing and marketing advantages, it is contemplated that this function can be achieved through the use of an integrated roller unit 220 which consists of a unitary or attached assembly of the roller sheet 256 , rod 258 , and a roller slip or securing strip 264 , which is a generally rectangular piece having a plurality of pegs 174 which engage with the openings 172 of the flexible material and into the holes or receptacles 161 . As shown in FIGS. 16 - 18 , the integrated roller unit embodiment utilizes a generally rectangular-shaped footplate having the plurality of pegs 174 in unitary engagement with the flexible material, such as a silicone sheet, and a rollstop. The pegs 174 engage with the openings 172 of the flexible material and into the holes or receptacles 161 (not shown) which aids in stabilizing the stopper. The roller unit further comprises a nonskid sole or under portion consisting of a rubber or other non-skid materials which further increases stability and reduces inadvertent or unwanted movement. This embodiment provides substantial timesaving in the making of properly formed and dimensioned sushi pieces by the user. In addition, these features may provide components which are more hygienic and easier to clean in food service, food preparation, or food manufacturing environments subject to health codes and regulations. For example, the rice and other materials may be readily released which would be advantageous to novice chefs or less skilled food preparation personnel. The roller sheet 56 is comprised of a flexible material bonded at one end 62 to a base plate 64 of a chosen dimension. In FIG. 7, the base plate 64 is approximately 8 inches by 8 inches, but can be in any size. The bottom of the base plate 64 has a slight incline of approximately one-quarter of one inch which acts as a stopping means 66 at the end of the rolling process when the chosen piece of Sushi is completed. Guide rails 68 may also be provided to aid in rolling the roller sheet 56 along the base plate 64 .
METHOD OF MAKING A CALIFORNIA ROLL OF THE PRESENT INVENTION
[0037] With reference to FIGS. 8 - 11 , a sheet of seaweed 70 is placed on roller sheet 56 . The seaweed should be sized to fit to the inside edge of guide rails 68 , if provided, and to the inside edge of the roller rod 58 and bottom edge 62 toward the stopping means 66 of base plate 64 . A layer of sushi rice 72 is spread on top of this sheet to cover the seaweed. If guide rails 68 are provided in the embodiment, the rice is preferably spread to the guide rails 68 and out to the roller rod 58 and bottom edge 62 of roller sheet 56 . A filling 74 (e.g. crab meat, Avocado, or other fillings) is then placed across the layer of rice approximately 1½″ from the roller rod 58 toward the stopping means 66 . Holding both handles 60 , the user picks up the top end of the roller sheet 56 , pulling the handles 60 and roller sheet 56 towards the bottom edge 62 and the stopping means 66 , thus rolling up a cylinder shaped Sushi Roll. When the sushi roll reaches the bottom edge 62 , the roller sheet 56 is draped over the stopping means 66 down to table level. Using both hands, the user compresses the sushi roll between the roller sheet 56 and the stopping means 66 , with light but firm pressure. This will form a finished roll. The roller sheet 56 is pulled back to its original position and the cylinder shaped sushi roll is removed from the stopping means 66 . Finally, the sushi roll is cut with a sharp knife into approx. 8 pieces depending on the desired serving size.
[0038] With reference to FIGS. 12 - 15 , another preferred embodiment of the present invention is there shown and includes a second preferred embodiment of a Nigiri Sushi mold 110 and a second preferred embodiment of a California Roll apparatus 154 for use in conjunction with the Nigiri Sushi mold 110 . This embodiment is shaped so that both apparatus of the present invention may be stacked and fit neatly within a box 18 with lid 20 (FIG. 1) to form a sushi kit 200 . The kit 200 is compact and is easily stored as a unit that can readily be formed into a Nigiri Sushi mold 110 and may also be quickly and easily assembled for making California Rolls.
[0039] In a particularly preferred embodiment, FIGS. 12 and 13 illustrate a Nigiri Sushi mold 110 for use with the Sushi kit 200 . The Nigiri Sushi mold assembly 110 is configured with a mold 112 , a plate 114 , a press 116 and a box 18 with a removable lid 20 (FIG. 1.) In a first example of operation, box 18 would be used as storage unit for mold 112 , plate 114 and press 116 . In a second example of operation, box 18 would be configured with regions configured to seat and serve the Nigiri Sushi. Mold 112 and plate 114 are of a rectangular configuration allowing for the plate 114 to readily set on lip 122 (FIG. 13) without the need for a male and female key arrangement as illustrated in FIGS. 1, 2 and 4 .
[0040] The mold 110 includes a flat surface 120 that is configured with at least one and, more preferably, a plurality of indentations 128 extending longitudinally along the flat surface 120 of mold 112 . The indentations 128 are shown at an angle but may be provided in any configuration. The indentations 128 are supported in part by supporting surface 132 and wall 134 which substantially surrounds both the indentations 128 and the supporting surface 132 . The indentations 128 are further configured with an elliptical hole 136 positioned substantially at the center of the indentations 128 , which is substantially smaller in both shape and dimension than the indentations 128 .
[0041] A plate 114 is configured with a flat surface 138 having an outer profile similar in size and shape to the inner surface 140 of lip 122 . Plate 114 is further configured with a plurality of funnels 144 which extend longitudinally along the flat surface 138 of plate 114 which are in alignment with indentations 128 . Opposing finger holes 149 (FIG. 15) are provided along the outer circumference to aid in removing the plate 114 from the top of the mold 112 after the Nigiri Sushi has been formed.
[0042] Referring specifically to FIG. 13, when the plate 114 and mold 112 are in alignment and flush with each other, extending member 148 of funnel 144 partially resides in at least one of the indentations 128 . The shape and size of extending member 148 is substantially similar to that of the outer area of at least one of the indentations 128 .
[0043] The number of funnels 142 may be equal to that of the number of indentations 128 of the mold 112 . However, it is foreseeable the number of funnels 142 are more or less than the number of indentations 128 . This may be preferable when it is desired to create mold 112 and plate 114 configurations to obtain a specific number of servings. It is contemplated that the funnels 142 may further comprise a spout or wave-shaped bottom edge which can assist in the formation of the rice into the desired oval or ball shape and allows the selected seafood item to shape and meet the respective contours.
[0044] Other important features of the present invention include the use of a press 116 , which is illustrated as having a first end 150 and a second end 152 . The first end 150 has a cross sectional shape substantially similar to that of the opening of funnel 144 such that the first end 150 can unobtrusively enter in and through funnel 144 and extending member 148 . The second end 152 has a cross sectional shape substantially similar to that of the elliptical hole 136 residing in the bottom of the indentations 128 such that the second end 152 can fit unobtrusively through elliptical hole 136 .
[0045] With reference to FIGS. 14 and 15, a second preferred embodiment is there shown for a method and apparatus for molding and forming traditional sushi pieces, such as California Rolls. More particularly, in this embodiment, a Sushi Roll Apparatus 154 is disclosed which utilizes a roller sheet 156 having an attached rod 158 with two ends or handles 160 used to physically roll and form the chosen food items into a piece of Sushi. The rod 158 is attached to a free end 159 of roller sheet 156 by attaching means such as pegs 161 extending downwardly from the securing strip 176 through the roller sheet 156 for attachment to a roller rod 160 via corresponding openings 172 , 174 . The roller sheet 156 is comprised of a flexible material bonded at one end 162 to a base plate 164 of a chosen dimension that has a plurality of holes 171 and seats within the inverted mold 112 and plate 114 of the Nigiri Sushi mold 110 illustrated in FIGS. 12 - 13 . Attaching means such as pegs 165 extend downwardly from stopping means 166 through corresponding openings 167 in one end 162 of the roller sheet 156 and openings 169 in base plate 164 and aligning with peg support holes 170 in the inverted mold 112 .
[0046] As best shown in FIGS. 14 and 15, the Sushi Roll apparatus 154 uses the inverted Nigiri Sushi mold 110 as a support base. To form the California Roll apparatus 154 , the plate 114 of the Nigiri Sushi mold 110 is inverted and supports the inverted mold 112 . Rod 158 is attached to roller sheet 156 by inserting pegs 161 through openings 172 and subsequently through openings 174 in securing strip 176 . Securing strip 176 may be made of any material, such as rubber, plastic, or silicone, that is rigid and will provide temporary or permanent securing means for supporting the rod 158 to the roller sheet 156 when in use. Stopping means 166 is removably secured to the support base 112 by extending pegs 165 through openings 165 , 167 for insertion into support holes 170 in the support base 112 . The Sushi Roll apparatus 154 is shown in its functioning form in FIG. 14. As described above in detail, the method for making and using the Nigiri Sushi mold and Sushi Roll apparatus are used to form sushi. The box 18 with lid 20 may be used as serving pieces for the sushi when not being used to store the kit 200 .
[0047] Although the invention has been described with particular reference to certain preferred embodiments thereof, variations and modifications can be effected within the spirit and scope of the following claims. | The present invention provides a kit ( 200 ) for producing a high quality sushi product with uniformity and at a high rate of production. The kit ( 200 ) includes a Nigir i Sushi mold ( 10, 110 ) and a California Sushi Roll apparatus ( 54, 154. ) In a preferred embodiment, the kit ( 200 ) includes a traditional Japanese bento box ( 18,20 ) that houses both the Nigiri Sushi mold ( 10, 110 ) and California Sushi Roll ( 54, 154. ) The Nigiri Sushi mold ( 10, 110 ) is made up of a mold ( 12, 112 ) having several indentations ( 28, 128 ) for supporting the preferred ingredients. The Nigiri mold ( 12, 112 ) is joined with the plate ( 14, 114 ) and is placed in the bottom half of the Japanese bento box ( 18 ) to form the lower portion of the Sushi kit ( 200 ) of the present invention. The apparatus ( 54, 154 ) used to form the California Rolls sits atop an inverted Nigiri mold ( 12, 112 ) with plate ( 14, 114 ) and includes a roller sheet ( 56, 156 ) that is flexibly attached to a base plate ( 64, 164. ) | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to floating docks, and, in particular, to durable polyethylene dock sections that are formed to provide a rigid, strengthened top surface that maintains its shape and provides a superior support and feel for persons walking on the section.
2. Description of the Prior Art
Floating marine docks formed of sections are commonly used as a means of providing access to and mooring for boats or as swimming or fishing platforms. Modular or sectional docks are frequently employed for constructing docks of various sizes and configurations. In the past, Styrofoam has commonly been used as the basis for docking modules. These modules, however, are unstable, cumbersome, hazardous to the environment, and are, therefore, limited in their applications. This creates a need for a buoyant modular dock made almost entirely of molded polyethylene or other environmentally stable materials.
In addition, the apparatus connecting modular docks together must be secure enough and strong enough to withstand high stress. Some prior art docks have secured floating dock sections together with joists, locking pins, mounting plates, springs and other fasteners, but each suffers from its own disadvantages. U.S. Pat. No. 5,281,055 utilizes rubber connectors that fit into sockets positioned at the top and bottom edges of the dock sections. To maintain flotation of the '055 patent dock sections if they are damaged so that they become filled with water, the sections are formed with a plurality of frustoconically shaped pylons that trap air for assisting in supporting the sections in the water.
The lateral and vertical movement that results from the action of wind and waves against floating docks puts considerable stress on the connecting apparatus which must be highly durable. Furthermore, the top surface of the dock sections must be supported to present a firm feel to a user. In addition, the amount of flexing of the top surface should be minimized to reduce the potential of stress cracking. A need exists, therefore, for a modular floating dock with a high strength connecting apparatus that is durable enough to be used in a variety of settings.
SUMMARY OF THE INVENTION
The present invention provides a durable modular floating dock section that can be utilized to form a variety of dock configurations for boating, swimming, fishing, and various other functions. The individual dock sections include a plurality of closely spaced apart parallel aligned troughs that are arranged in a transverse relationship to the length of the sections. The sections can be connected together by using a connecting member to form a variety of design configurations. The connecting member is comprised of two flanges that each fit into a complementary receiving socket on two adjacent dock sections. The connecting member and dock sections can be further secured together by a bolt and nut. Other modular pieces, such as a pole bracket, can be connected to the dock sections in a similar fashion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective top view of a preferred embodiment of the components of a floating dock of the present invention formed of two dock sections and three connecting members that are used to secure the dock sections together.
FIG. 2 is a perspective view of a preferred embodiment of one of the connecting members shown in FIG. 1 .
FIG. 3 is a side view of the connecting member of FIG. 4 .
FIG. 4 is a top view of the connecting member of FIG. 4 .
FIG. 5 is a perspective bottom view of one of the dock sections of FIG. 1 .
FIG. 6 is a cross sectional view of one of the dock sections of FIG. 1 taken along the line 6 — 6 of FIG. 1 .
FIG. 7 is a perspective view of a pole bracket that can be attached to a dock section.
FIG. 8 is a top view of the embodiment of FIG. 7 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention involves a floating dock 10 , as shown in FIG. 1, comprised of at least two dock sections 11 of the present invention. Preferably, the sections 11 are connected together by three connecting members 12 to provide a wobble free connection therebetween. However, it should be recognized by those skilled in the art that a single connecting member 12 could be used where conditions allow. Each dock section 11 is, in the preferred embodiment, a one piece molded body and may be of any shape, although a square or rectangular shape is preferred. The dimensions of each dock section 11 can vary depending upon its intended location and design. In the preferred embodiment, each section 11 is generally rectangular in shape, forty-five inches long, thirty inches wide, ten inches high and weighs approximately fifty pounds.
The dock sections 11 can be constructed of any suitable material, but preferably they are made of molded polyethylene, because it possesses strength and durability, is resistant to gas, oil and other contaminants and is also stable on the water. Each dock section 11 is generally hollow. The wall thickness of the dock sections 11 can vary, but a range of one-eighth inch in protected areas to three-eighth inch in exposed areas like outside corners, and with a wall thickness on the top (walking) surface of approximately one-fourth inch, is preferred.
Spaced about the perimeter of the dock sections 11 are a plurality of receiving sockets 13 . It is preferred that the sockets 13 are uniformly spaced along the sides and ends of each dock section 11 so that two sections can be connected together in a variety of ways. The dock sections 11 can have any appropriate number of sockets 13 , although in the preferred embodiment, three such sockets are located along the long side of the dock section 11 and two sockets are located along the short side.
Referring now to FIGS. 2, 3 and 4 the connecting members 12 are used to attach the dock sections 11 together and are complimentary in shape to the sockets 13 . Each connecting member 12 has a body 15 with at least two flanges 16 , and each flange 16 is received in and interlocks with a receiving socket 13 . Each flange 16 has an inwardly tapered post section 17 adjacent to which is a top recess 18 . In the preferred embodiment, the body 15 further includes two side members 19 that are somewhat similar in shape to the flanges 16 and extend from opposite sides thereof. Each side member 19 is notched to form a recess 20 , and the flanges 16 have lower ledge portions 24 that are spaced from the side members 19 to form bottom recesses 25 .
In the preferred embodiment, the top of each post section 17 contains a threaded bore 26 molded therein. Securing means, such as a bolt (not shown), can then be positioned through holes 28 in the top of the dock section 10 and secured in the bores 26 . This serves to semi-permanently secure the dock section 10 and its associated connecting member 12 together.
As shown best in FIG. 5, the sockets 13 each comprise a central, vertically oriented, tapered recessed portion 30 that is complementary in shape to one-half of a connecting member 12 , as described below so that they fit together in an interlocking relationship. At the top of each socket 13 is a top overhang 31 intended to fit into the top recess 18 of one of the connecting members 12 . In the preferred embodiment, the sockets 13 further comprise two bottom overhangs 32 that interlock with the bottom recesses 25 of one of the connecting members 12 , and two side overhangs 33 that interlock with the recesses 20 in the side members 19 to thereby provide an efficient, effective and durable means for interlocking the dock sections 10 together.
To increase the structural strength of the dock sections 10 , a number of parallel aligned troughs 35 and 36 (FIG. 5) of a generally rectangular shape extend from the bottom upward toward the top of each dock section 10 . These troughs 35 and 36 each define a cavity in the dock section 10 , so that air is captured within the trough 35 when the dock section 10 is positioned in the water. The sides of the troughs 35 and 36 also provide structural support against downward or lateral pressure applied to the dock sections 11 and minimize flexing of the top surface of the sections 11 . In the preferred embodiment, the troughs 35 and 36 comprise a total of five and extend along the bottom of the dock section 10 .
There are three of the troughs 35 , which are shorter than the troughs 36 and extend between the receiving sockets 13 on their respective sides. There are two of the long troughs 36 that are unencumbered by the receiving sockets 13 so as to extend from side to side. In the preferred embodiment, the short troughs 35 are approximately nineteen inches long, four inches wide and nine and one-half inches deep, and the long troughs 36 are approximately twenty-five inches long, four inches wide and nine and one-half inches deep. Accordingly, a majority of the bottom of the dock sections 11 is formed from the troughs 35 and 36 . As shown by FIGS. 5 and 6, the ceilings of the troughs 35 and 36 are formed with transverse ribs 37 to improve the flow of plastic during molding and productability of the sections 11 . The top of each dock section 11 is formed with a plurality of parallel aligned, spaced apart elongated indentations 38 (see FIG. 1) that span each section 11 , which indentations are located in an alignment between each of the troughs 35 and 36 to further minimize the amount of flexing of the dock section top surface and thereby reduce the potential of stress cracking.
To stabilize the dock 10 , it is highly preferable to utilize one or more stabilizing poles (not shown) to brace the floating dock. Each stabilizing pole can be secured to the dock by the use of a pole bracket 40 as shown in FIGS. 7 and 8. Each of the members 40 is comprised of a flange section 41 and a pole section 42 that contains a pole hole 43 . The flange section 41 is similar in shape to the flanges 16 . Thus, each pole bracket 40 can be secured in one of the receiving sockets 13 . Other types of attachments and accessories, such as gangways, ladders, boat moorings, and floating dry docks for watercraft (all not shown) can also be attached to the dock by the use of members that interlock with the receiving sockets 13 .
In application, the dock sections 10 are connected together with the use of connecting members 12 into a desired configuration. Any dock section 11 can easily be secured to the shore through the use of arms, cables, gang planks or other means. The present invention thus provides a complete floating dock that does not require additional elements for use, such as boat bumpers or wood planking, or additional parts for assembly. The polyethylene dock sections 11 are durable, stable and have a long life. The shape of the flanges 16 and receiving sockets 13 ensure that the dock sections 11 will remain securely attached by the connecting members 12 so that the dock sections 11 will not separate during use. The connecting members 12 also result in a tight fit and a very small gap between the dock sections 11 , and this increases the ease and safety of walking on the dock 10 .
While a preferred embodiment of the present invention has been described, it should be understood that various changes, adaptations and modifications may be made therein without departing from the spirit of the invention and the scope of the appended claims. | A floating dock section that is secure, economical and durable and can be coupled together with a similar type section by a connecting member that fits into a socket of the dock section. Each connecting member has flanges that fit into receiving sockets of two adjacent dock sections to form a dock of a preferred configuration so that the dock sections can be arranged in a plethora of configurations. Modular pieces for end posts and other accessories can be added. The bottom surface of the dock section includes a plurality of rectangularly shaped closely spaced apart troughs that are in a parallel alignment with one another. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to a device for installing tiles on surfaces to be lined, such as walls and floors.
As is known tiles are currently installed by means of a binder (adhesive, cementitious mortar) interposed between the bottom surface of the tiles and the surface to be lined or coated.
The surface is composed of a layer of cementitious mortar which serves as the substrate and is suitably smoothed and in which are embedded the pipes for the utilities such as heating, water and electricity.
The traditional technique of tile installation has some serious drawbacks. First of all, it is time consuming and requires specialized labor. Moreover, if it becomes necessary to service underlying pipes for making connections or repairs, part of the lining must be pulled down, which most of the times involves replacement of all of the tiles because the ones pulled down, years after their installation, are no longer available.
SUMMARY OF THE INVENTION
This invention sets out to provide a device which facilitates and speeds up the installation of the tiles and, when necessary, permits their removal.
This object is achieved by a device which is characterized in that it comprises a support whereto a tile is to be attached with the interposition of adhesives and which is provided with means for a rabbet coupling to means anchored to the surface to be lined.
BRIEF DESCRIPTION OF THE DRAWING
Further features will be more clearly apparent from the following description in conjunction with the accompanying drawing, where:
FIG. 1 is a perspective, partly sectional, view of a floor wherein the tiles have been applied with a device according to the invention;
FIGS. 2 and 3 are sectional views of the rabbet coupling means;
FIG. 4 is a perspective view of a tile and the surface to be lined, provided with the coupling means of FIG. 2;
FIG. 5 is a perspective view of a further embodiment of the invention; and
FIG. 6 shows a detail of the coupling means anchored to the surface to be lined.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The device for tile installation comprises a rigid support 1 whereto, with the interposition of a layer 2 of a suitable adhesive, is to be attached an ordinary tile 3 of ceramics or other material. The support 1 is formed from resins or inert materials and has, at two opposite parallel sides, a projection 4 and recess 5 which lie in the plane of the support 1. From the lower or bottom face of the support 1 there project coupling means in the form of mushrooms 6, uniformly spaced along parallel rows. The mushrooms 6 are adapted for rabbet engagement in the grooves 7, either of dovetail or inverted "T" configuration, of sectional anchoring members 8 embedded in a mortar layer 9 covering the floor 10. Spacers 11 are effective to hold the sectional members 8 spaced apart and perfectly parallel to one another.
To facilitate the insertion of the mushrooms 6 into the grooves 7, the sectional members 8 are made of a material possessing a certain elasticity at least at the mouth of their groove. Suitably, to prevent the layer 9 from neutralizing this ability to flex, the sectional members 8 have a cross-section as indicated in FIG. 6, where the groove 7 is formed by two wings 12 which define on the outsides two interspaces 13 which prevent the mortar of the layer 9 from adhering to the wings 12 to allow the latter to flex during the introduction of the mushrooms 6.
The tiles are installed by aligning them and forcing the mushrooms 6 into the grooves 7. It should be noted that to take up the play, or clearance, between adjacent tiles, provision is made for the use of a material adapted for sealing the joints between the adjacent edges of the tiles and between the projections 4 and recesses 5 of the supports.
The coupling means of the support to the floor or wall may differ from the ones described above.
In the embodiment of FIG. 2, provision is made for tubular projections 14 to protrude downwards which are provided, at the free end, with an inner annular embossment 15 and axial notches 16. The tubular projections 14 are intended for coupling to cup-like anchoring elements embedded in the mortar layer 9 which covers the floor. Each element comprises a flange 17 wherefrom there project two rings 18,19, concentrical to each other and separated by an annular interspace 20. The inner ring 19 has axial notches 21 and an outer groove 22. In a suitable manner, the projections 14 and cup elements are distributed all over the surface of the support and floor, as shown in FIG. 9.
The coupling of the support to the wall is effected by introducing the projections 14 into the annular interspaces 20 such that the annular embossments 15, by engaging with the grooves 22, produce a catch which prevents the projections 14 from sliding out. The variation of FIG. 3 differs from that of FIG. 2 in that the tubular projection 14 is provided with an outer collar 23 and that the inner ring 19 is provided with an inner groove 24. In this embodiment, the projection 14 penetrates the ring 19 until the projection 23 engages in the groove 24. The interspace 20 has the function of preserving the elasticity of the inner ring 19 to prevent the latter from being blocked by the mortar of the layer 9.
Finally, in the embodiment of FIG. 5, the coupling of the tile to the floor is obtained by providing on the latter sectional members 25 of mushroom cross-sectional shape adapted for rabbet insertion in complementary grooves 26, formed in the lower face of the support 1. It should be noted that from the edges which form one corner of the support there rise two side pieces 27,28 having the same height as the tiles which form a square adapted for facilitating the positioning of the tiles and creating a thickness between the tiles which has the function of taking up plays and of sealing the joints.
The device according to the invention, thanks to the elastic retention between the coupling means, permits at any time removal of the tiles for servicing the underlying pipes 29 embedded in the layer 9.
The application of the tiles 3 to the supports 1 can be carried out at the factory. The adhesive layer 2 may have a thickness such as to ensure that the combined thickness of the tile and support is strictly constant. Thus, it is possible to make a correction that cancels the thickness deviations of the tiles.
The device, in addition to permitting the tiles to be installed flat, also allows the application of wall linings. The sealant which is interposed between the adjacent edges of the tiles and between the projections 4 and recesses 5 will have a limited adhesive power dependent on the individual requirements. | A device for installing tiles on surfaces to be lined comprises a support, whereto a tile is to be attached by an adhesive, and provided with rabbet coupling elements effective to provide a rabbet coupling with the surface to be lined on which counter rabbet coupling means are anchored. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention.
The present invention relates to surgical retractor apparatus, and in particular, it relates to a retractor used to retract organs.
2. Description of the Prior Art.
Surgical retractors are customarily used during major surgery to hold back the incision area to expose the area in which the surgeon operates. Abdominal surgery presents particular problems because of the presence of large soft organs, especially long lengths of intestines. The positioning during surgery of these lengths of intestines is vitally important to the success of the surgery. The intestines can obscure the surgeon's vision if the intestines are not held back by retractors. On the other hand, the intestines themselves are fragile and puncture results in contamination of the field of surgery greatly increasing the risk of post-operative infection.
In the prior art, surgical absorbent clothes or sponges, sometimes with the addition of hard metal retractors, have been used to hold and separate the intestines from the point of surgery.
The Rudie U.S. Pat. No. 3,372,696 describes the use of an abdominal pad having a flexible body member having a slight degree of rigidity with a weighted pocket formed at one end for holding back the intestines.
The Kohlmann U.S. Pat. No. 3,749,088 describes a retractor having a blade with a lower flexible end portion.
The Hurson U.S. Pat. No. 4,048,987 describes a hand-shaped retractor with a wire core having a multi-member body portion and a handle portion. The members of the body portion are individually adjustable.
The James U.S. Pat. No. 3,467,079 describes a retractor having a shaft that ends in a hook and a winged blade.
The Kadavy U.S. Pat. No. 1,947,649 describes a surgical instrument having a pair of pivotally connected members having a pair of outwardly extending arms that are inserted into a rubber covering. The arms are extended outwardly so that the covering is held taut between the two arms.
The Sinnreich U.S. Pat. No. 4,190,042 describes a flexible retractor having a bifurcated member with a flexible membrane tensed between segments of the bifurcated member.
The LeVahn U.S. Pat. No. 4,355,631 illustrates conventional retractors.
SUMMARY OF THE INVENTION
A retractor apparatus includes a retractor blade having a malleable element that defines a blade perimeter and a retractor area. A flexible member is supported by the malleable element and extends over the retractor area.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the retractor apparatus of the present invention, in its position of use, the retractor apparatus being supported by a retractor support;
FIG. 2 is a perspective view of the support member of the retractor device of the present invention; and
FIG. 3 is a perspective view of the retractor apparatus of the present invention in a flat state.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the drawings, like reference characters will be used to indicate like elements throughout the several views. A retractor device of the present invention is generally indicated at 10 in FIG. 1. The retractor 10 includes a blade 14 attached to a support member 12. The blade 14 includes a transparent membrane 16 supported by a wire element 18 in the form of a continuous loop. The wire element 18 has first and second ends 20 and 22 that are attached to the support member 12. Although the wire element 18 is shown in substantially rectangular form, the wire element may take various other shapes and be within the scope of the invention.
In the embodiment illustrated, the transparent membrane 16 is in the form of a bag having an open end 24. The wire element 18 is disposed within the bag forming the blade 14. The wire element 18 is inserted into the open end 24 and the open end 24 is heat sealed along the lines indicated by reference character 26. Alternatively, the membrane 16 need not be in the form of a bag. The membrane 16 may be a single layered membrane that is fixedly attached to the wire element 18. Preferred materials for the membrane 18 include polymeric films. A suitable polymeric film is polyethylene.
Preferably, the membrane 16 is slack, as illustrated in FIG. 1. By slack is meant that the membrane forms a slight pouch or an indentation in which an organ 28 is retained. For example, the retractor device of the present invention is used to retain the bowel during deep abdominal surgery. Unlike retraction of muscle, soft tissue retraction, such as the bowel, presents a unique problem. Not only must the organ be held securely out of the way during surgery, the organ must be held in as gentle a manner as possible so that it is not damaged and circulation through the organ is not affected. The membrane provides a flexible surface, and, in the membrane's relatively slack state, an indentation or pouch is formed when the retractor is placed against the organ 28. Using the device of the present invention, the organ is gently but securely held in place, minimizing the chance of the organ sliding parallel to the retractor blade surface and out of a "retained" position. Although preferably the membrane 16 is in a slack state, the membrane could be taut, that is, held under tension, and still provide adequate retraction. In such a case, the flexibility of the film provides a retraction surface that gently retains the organ.
In addition, the membrane 18 is preferably transparent so that the organ 28 is viewable through the membrane 16. By transparent is meant that the organ is sufficiently viewable so that the condition of the organ can be ascertained. For example, lack of circulation may be indicated by a discoloration of the organ. Such discoloration should be visible through the membrane.
To further aid in holding the organ, the wire element 18 is made of a malleable material. By malleable is meant that the wire element is bendable and then stays bent in the selected shape or form in which it is bent. As illustrated in FIG. 3, the blade of the retractor device of the present invention is initially in a flat state. The surgeon then bends the wire element to form the blade to a selected shape. It will be appreciated that each surgical procedure can be different and that the capability to form the retractor to a desired shape to the needs of a particular situation is highly desirable.
In the working embodiment illustrated in the figures, the wire element is made of stainless steel and can be sterilized for repetitive use. In an alternative embodiment, the wire element may be made of metal other than stainless steel and then coated. For example, the wire element, along with the support member 12, are encased entirely in a polymeric resin, such as polyvinyl chloride or an epoxy resin. In addition, a foamed resin coating may be applied to the wire element. Coating the wire element and the support member 12 in a plastic resin permits usage of material much less expensive than stainless steel, making the device of the present invention a disposable item.
The support member 12 is made of flat sheet metal and has a main portion 30 and secondary portion 32 disposed at approximately a right angle to the main portion 30. The portion 32 includes apertures 34 and 36 through which extend the ends 20 and 22 of the wire element 18. The apertures 34 and 36 are located adjacent the main portion 30 such that the ends 20 and 22 can be fixedly attached to the portion 30 by welding.
The support member 12 further includes an aperture 38. The aperture 38 permits attachment of the retractor device 10 to a retractor support clamp 40, as illustrated in FIG. 1. The retractor support clamp is then held by a suitable retractor support, such as illustrated and described in the LeVahn et al U.S. Pat. No. 4,617,916, assigned to the same assignee as the present application, and herein incorporated by reference. Although the specific retractor apparatus in the LeVahn et al Patent is mentioned, any suitable retractor support can be used with the retractor device of the present invention.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. | A retractor apparatus includes a retractor blade having a malleable element that defines a blade perimeter and a retractor area. A flexible member is supported by the malleable element and extends over the retractor area. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and a method for sensing the presence of a liquid by observing the temperature behavior of a heated temperature sensor. The principle of operation of the present invention is to determine whether the sensor is surrounded by a gas or a liquid or to determine which of two immiscible liquids surround the sensor by determining the external thermal load upon the sensor. The thermal load upon the sensor is determined by heating the sensor by application of a predetermined amount of thermal energy and observing the rate of temperature increase of the sensor. If the temperature sensor is surrounded by a gas, there is less thermal conduction away from the sensor than if same sensor was surrounded by a liquid. That is, a gas would absorb less of the thermal energy within the temperature sensor via convection than would the liquid. As a consequence, for a given amount of thermal energy applied to the temperature sensor, the sensor would reach a greater temperature in a gas than in a liquid. A similar condition would occur if the temperature sensor could be immersed in one of two immiscible liquids having differing thermal conductivities. Thus, observation of the rate of temperature increase of the temperature sensor enables a determination of the type of fluid surrounding the sensor.
The above mentioned scheme for determining the presence of a liquid has a problem in that the rate of temperature rise is dependent not only upon the type of fluid surrounding the temperature sensor, but also upon the initial temperature of both the sensor and the fluid. Therefore, in order to employ this method of liquid level sensing, it is necessary to compare the temperature of the temperature sensor with a reference signal which has an initial value dependent upon the initial temperature of the sensor and a rate of change dependent upon both the initial temperature of the sensor and upon the rate of heating of the sensor.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an apparatus and a method for detecting the presence of a liquid having particular predetermined thermal properties by observing the temperature change of a temperature sensor heated at a predetermined rate for a predetermined period of time.
It is another object of the present invention to enable liquid level sensing in a manner described above in which the temperature measured by the temperature sensor is compared with a temperature reference signal which has an initial value related to the initial temperature measured by the sensor and further has a rate of change dependent upon the rate of heating of the sensor and the initial temperature.
It is a further object of the present invention to enable liquid level sensing in the manner described above further including a latching output whenever the temperature measured by the temperature sensor and the temperature reference signal have a predetermined comparative relationship at any time during the predetermined period of time.
It is still a further object of the present invention to provide liquid level sensing in the manner described above in which the temperature sensor is repeatedly heated at the predetermined rate for the predetermined time and then permitted to cool for a further predetermined period of time.
One embodiment of the present invention is an autoreferencing liquid level sensing apparatus including a temperature sensor at the liquid level detection position, a heater, a temperature reference source and a comparator.
A second embodiment of the present invention is an autoreferencing liquid level sensing method including the steps of placing a temperature sensor at the liquid level detection position, adding thermal energy to the temperature sensor, generating a temperature reference signal and comparing the temperature measured by the temperature sensor and the temperature reference signal.
A third embodiment of the present invention is an autoreferencing liquid level sensing circuit for use with a temperature sensor including an electric power regulator, a temperature reference source and a comparator.
In one prefered embodiment of the present invention the temperature sensor is a temperature sensitive resistance element disposed at a position where the liquid level is to be determined, the heating means is an electrical power source applying a predetermined amount of electric power to the resistance means for the predetermined period of time and the temperature reference signal is provided by a capacitor which is initially provided with an electric charge related to the initial temperature and which is discharged towards a fixed voltage throughout the predetermined period of time.
In another preferred embodiment of the liquid level sensor of the present invention, a latch output signal is generated upon detection of a predetermined relationship between a temperature dependent signal and temperature reference signal at any time during the predetermined period of time.
In a further preferred embodiment of the liquid level sensor of the present invention, a voltage regulator provides power at a first predetermined voltage to the electric power source whenever it receives electric power having a voltage greater than a second predetermined voltage and further includes a latch inhibiting function which prevents generation of the latch output signal whenever the electric power received by the voltage regulator has a voltage less than the second predetermined voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects of the present invention will become clear from the following detailed description of the invention taken in conjunction with the drawings in which:
FIG. 1 is a graph comparing the temperature of the heated temperature sensor in liquid and gas and the temperature reference for two initial temperatures;
FIG. 2 is an overall system block diagram of the present invention;
FIG. 3 is a graph of the specific resistivity of N-type silicon as a function of temperature;
FIG. 4 is an illustration of one embodiment of the temperature sensor of the present invention;
FIG. 5 is a block diagram of a practical embodiment of the present invention employed as an automobile crankcase oil level detector;
FIG. 6 is an illustration of the typical sensor network voltage for oil response, air response and the reference level at two different temperatures;
FIG. 7 is a practical circuit diagram of the present invention employed as a crankcase oil level detector; and
FIG. 8 is a practical circuit diagram of the present invention having a repeated measuring function.
DETAILED DESCRIPTION OF THE INVENTION
The invention of the present application enables discrimination between a liquid and a gas or between two immiscible liquids having differing conductivities and therefore provides a liquid level indication. The principle of operation of the present invention is to determine the external thermal load upon a heated temperature sensor. The temperature sensor is disposed in the liquid container in a position at which it is desired to determine the liquid level. The temperature sensor is then heated at a predetermined rate for a predetermined period of time during which the temperature measured by the temperature sensor is observed. If the temperature sensor is surrounded by a gas, there is a smaller thermal load imposed upon the sensor than if the same sensor were surrounded by a liquid. That is, a gas would absorb less of the heat energy within the temperature sensor via convection than would a liquid. As a consequence, for a given amount of thermal energy applied to the temperature sensor, the sensor would measure a greater temperature gain in a gas than in a liquid. A similar condition would occur if the sensor could be immersed in one of two immiscible liquids having differing thermal conductivities.
An illustrative graph showing the temperature measured by the heated sensor for two differing initial temperatures is shown in FIG. 1. A first set of curves illustrates the measured temperature when the initial temperature is T 1 . In the case of both the gas response and the liquid response, the measured temperature at time is t 0 to T 1 . For later times, as the temperature sensor is heated, the gas response diverges from the liquid response, reaching higher temperatures than the liquid response throughout the remainder of the heating interval. A similar situation is illustrated for a higher initial temperature T 2 . It should be clearly understood that the rate of change of each of the liquid and gas temperature response curves illustrated in FIG. 1 is critically dependent upon the rate of heating of the temperature sensor.
With the temperature response curves illustrated in FIG. 1 in mind, it is readily seen that discrimination between the liquid response and the gas response cannot be obtained on the basis of a single fixed reference level. Not only does each response vary with time, but the ultimate temperature reached as well as the rate of change is dependent upon the initial temperature. For example, a temperature reference level of T 9 discriminates between the ultimate liquid response temperature T 3 and the ultimate gas response temperature T 5 for the case in which the initial temperature is T 1 . However, note that a reference level of T 9 does not discriminate between the liquid response and the gas response during a first portion of the predetermined period of heating the sensor. In addition, a reference level of T 9 never distinguishes between the responses if the initial temperature is T 2 , because throughout the interval of heating, both the liquid response and the gas response are greater than this reference level.
As can be seen from a study of the curves illustrated in FIG. 1, the reference necessary to distinguish between the liquid response and the gas response must be both time varying and temperature dependent. An example of such an adapting reference is illustrated in FIG. 1. Note the reference level curve starting at temperature T 7 at time t 0 and ultimately reaching temperature T 9 . This curve is initially greater than the initial sensor temperature of T 1 and has an ultimate value between the liquid response ultimate value of T 3 and the gas response ultimate value of T 5 . Thus, this reference level crosses the gas response at time t 1 and never crosses the liquid response. This reference must be made temperature dependent as illustrated in the reference curve from temperature T 8 to temperature T 10 for the case of an initial sensor temperature of T 2 . In this case, the reference crosses the gas response at time t 2 and never crosses the liquid response. These reference curves may be generated by setting their inital values at some percentage above the initial temperature of the sensor and setting their rate of change to be substantially parallel to the liquid response rate of change for the corresponding initial temperature. In such a case the liquid response would never cross the reference level, whereas the initial value of the reference level can be set so that the gas response will cross the reference level at some point during the heating interval. This requires some reference source which models the liquid response temperature gain of the sensor during the heating interval. Although it is not illustrated in FIG. 1, it is equally clear that another type of adapting reference may be employed. By setting the initial reference level at a percentage below the initial temperature and providing a rate of change to the reference level substantially parallel to the gas response, the reference level will cross the liquid response at some point during the heating interval, but will never cross the gas response. Reference curves of this type are not illustrated in FIG. 1 for the purpose of clarity.
It is should be clearly understood that the situation illustrated in FIG. 1 is equally applicable to the case in which the temperature sensor may be surrounded by one of two immiscible liquids. In such a case the gas response curves illustrated in FIG. 1 would correspond to the response curves of the liquid having the lower thermal cnductivity.
FIG. 2 illustrates a block diagram of the present invention generally designated by the reference 100. Heater 101 applies thermal energy to sensor 102 at a predetermined rate for a predetermined period of time. Sensor 102 is disposed in liquid vessel 103 at a position to distinguish between Level 1 of the liquid and Level 2 of the liquid. The resulting temperature dependent signal of sensor 102 is applied to both temperature reference 104 and comparator 105. Temperature reference 104 samples the initial temperature measured by sensor 102 and then produces the proper temperature reference signal such as illustrated in FIG. 1. Because the temperature reference signal is set at an initial value corresponding to the initial temperature dependent signal, this technique is called autoreferencing. The temperature dependence signal of sensor 102 and the temperature reference signal of temperature reference source 104 are both applied to comparator 105 which produces an output indicative of their relative levels. This comparator output signal may be employed directly or it may be fed to an optional latch circuit such as a latch 106 enclosed in the dashed lines. Latch 106 would provide a latch output response if the crossing condition ever occurred during the heating interval. In the case of the reference levels such as illustrated in FIG. 1, latch 106 would provide the latch output signal if the comparator output signal ever indicated that the temperature dependent signal was greater than the temperature reference signal. As illustrated in FIG. 1, such a condition would indicate that the level of liquid in vessel 103 is below the position of sensor 102, and therefore the sensor was surrounded by gas.
It has been found convenient in embodiment of the present invention to employ a temperature sensitive resistance element for sensor 102. This choice of temperature sensor 102 enables embodiment of heater 101 with an electric power source. This electric power source would apply a predetermined amount of electric power to the sensor for the predetermined heating interval causing Joule heating in the temperature sensitive resistance element.
One preferred embodiment of the temperature sensitive resistance element employed as sensor 102 includes a doped silicon bulk resistor element. This temperature sensitive resistance element is constructed according to principles illustrated in FIGS. 3 and 4. The silicon used in the silicon bulk resistor element has a carefully controlled impurity concentration of a specific element. Control of this impurity concentration enables substantial control of the temperature dependent resistance characteristics of the resistance element as illustrated in FIG. 3. FIG. 3 illustrates the specific resistivity of N-type silicon as a function of temperature for various donor impurity concentration levels. A donor impurity atom is an atom which provides an additional electron when bound within the silicon crystalline structure. Within the intrinsic region, the specific resistivity is independent of the impurity concentration level. Within this region, the silicon exhibits a negative temperature coefficient of resistance, that is, the resistance decreases with increasing temperature. Within the extrinsic region, the specific resistivity of the silicon depends upon the impurity concentration level. Within the region, the temperature coefficient of resistance is positive, that is, the resistance increases for increasing temperature. This relation is clearly illustrated in FIG. 3 for each of several different impurity concentration levels. As can be seen from the curves illustrated in FIG. 3, selection of the impurity concentration enables selection of the specific resistivity of the silicon employed (note the various specific resistivities at the reference temperature of 25° C.) and also enables selection of the temperature at which the silicon switches from the extrinsic to the intrinsic region. The silicon bulk resistor employed in the sensor of the present invention has an impurity concentration causing an extrinsic positive temperature coefficient of resistance throughout the expected range of operating temperatures.
The structures of the preferred embodiment of the temperature sensitive resistance element of the present invention is illustrated in FIG. 4. The temperature sensitive resistance element as a whole is designated 200. It includes a silicon bulk resistor 201, shown in dashed lines in FIG. 4. The bulk resistor 201 is sandwiched between electrodes 202 and 212. Electrode 202 includes a thick vertical portion 203, a thinner horizontal portion 204 and a contact paddle 205 which is in contact with one surface of bulk resistor 201. Similarly, electrode 212 includes thick vertical portion 213, thinner horizontal portion 214 and paddle 215. The electrodes 202 and 212 are embedded in a plastic spacer 206 which serves to provide mechanical stability for the entire structure. The temperature sensitive resistance element may be mounted via spacer 206 and electrodes 202 and 212 may be connected to an electric power source serving as heater 101. This electric power causes Joule heating of bulk resistor 201. The temperature of the temperature sensitive resistance element is indicated by the resistance of bulk resistor 201. This resistance may be determined by measuring the voltage applied to the sensor and the current flowing through the sensor.
The block diagram of a practical circuit employing the present invention used as an automobile crankcase oil level indicator is illustrated in FIG. 5. The apparatus is connected to the automobile DC power supply through filter and polarity guard 301. Filter and polarity guard 301 provides protection against inadvertent misconnection of the apparatus in a reverse polarity and provides some filtering for any AC components in the automobile's DC power supply. Filter and polarity guard 301 feeds power to first regulator 302. The first regulator 302 provides a relatively stable DC output voltage from the automobile DC power supply, because the automobile power supply is known to exhibit wide voltage swings. The output of first regulator 302 is coupled to second regulator 303 which provides a further stabilized DC voltage. This further stabilized DC voltage is applied to sensor power 304. Sensor power 304 is coupled to sensor network 305 and provides the predetermined electric power during the heating interval. Sensor network 305 is a voltage divider including temperature sensitive resistance element 305a and a resistor 305b. Temperature sensitive resistance element 305a is disposed in the automobile crankcase at a position corresponding to the one-quart low oil level. This position has been selected as a convenient position for generating a warning signal to the driver concerning the oil level. The voltage at the node of the sensor network 305 between temperature sensitive resistance element 305a and resistor 305b is applied to both a reference network 306 and comparator 308. Reference network 306 is also a voltage divider which applies a percentage of the voltage of the node of sensor network 305 to temperature reference 307. As will be explained in greater detail below, this connection serves to set the temperature reference at the proper initial value in relation to the initial temperature measured by temperature sensitive resistance element 305a as required by the autoreferencing technique of this invention. Comparator 308 receives the signal from the node of sensor network 305 and a temperature reference signal from temperature reference 307. As explained in further detail below, comparator 308 provides a comparator output signal if the voltage of the node of sensor network 305 falls below the temperature reference signal from temperature reference 307. This comparator output is applied to latch logic 309 which produces a latch output signal to output 310 if comparator 308 ever generates the comparator output signal during the heating interval. Low voltage detector 311 receives a signal from first regulator 302 and applies signals to latch logic 309 and timer 312. It has been discovered that the automobile DC power supply voltage may occasionally momentarily fall so low that either comparator 308 or latch logic 309 would inadvertently trigger an erroneous output. Low voltage detector 311 determines when the voltage applied to the apparatus is so low that such an erroneous output may be produced and serves to inhibit the action of latch logic 309 during this low voltage condition. Timer 312 provides outputs to sensor power 304 and latch logic 309. Timer 312 thus sets the predetermined heating interval during which sensor power 304 applies the predetermined heating power to the temperature sensitive resistance element 305a. In addition timer 312 also provides a signal to latch logic 309 so that latch logic 309 is enabled only during the heating interval. Timer 312 receives a signal from low voltage detector 311 which serves to slow or suspend the timing operation during a low voltage condition. This function is provided because during the time in which the low voltage detector determines that latch logic 309 may be falsely triggered due to the low supply voltage, the amount of power applied to temperature sensitive resistance element 305a from sensor power 304 is below the predetermined amount of power. Thus this function provides a time out operation during which the function of the apparatus is largely suspended awaiting return of normal power levels.
FIG. 6 illustrates the typical voltage response at the node of the sensor network together with the temperature reference at two initial temperature levels. Note that because temperature sensitive resistance element 305a has a positive temperature coefficient of resistance throughout the region of expected temperatures, increasing temperature means an increasing resistance for temperature sensitive resistor 305 and therefore a decrease in the voltage level at the node. Therefore, the initial voltage of the node is lower at 125° C. than at -20° C. as illustrated in FIG. 6. Also please note that the voltage response curves slope downward during the heating interval also indicating a decreasing node voltage for higher sensor temperatures. Reference network 306 enables the temperature reference to be set at a percentage of the sensor network node voltage as illustrated in FIG. 6. Once set at this initial value, the temperature reference signal then has a decreasing value, indicating an increasing reference temperature, as illustrated in FIG. 6. Also note that the rate of change of the temperature reference signal is dependent upon the initial value.
FIG. 7 illustrates a practical circuit diagram of the oil level sensing circuit system illustrated in FIG. 5. The circuit of FIG. 7 employs lamp L1 for indicating the output results. Because the engine oil level becomes unstable due to splashing shortly after beginning engine operation, the circuit illustrated in FIG. 7 is designed to check the oil level once each time the engine is turned on. Lamp L1 is employed as an output indicator. The circuit is designed to flash lamp L1 once when power is first applied as a system check. If the circuit detects the sensor S1 is above the oil level, that is if the circuit determines that the oil is below the one-quart low point in the crankcase, lamp L1 is driven in a flashing mode to indicate the low oil level.
The filter and polarity guard 301 of FIG. 5 is provided by diodes CR1 and CR8 in FIG. 7, and the combination of resistor R1 and capacitor C1. Please note that if the circuit is inadvertently connected in the reverse polarity, diode CR1 is reverse biased preventing application of the reverse polarity voltage to most of the circuit while diode CR8 is forward biased turning on lamp L1. The first regulator function is provided by resistor R16 and zener CR9. Zener diode CR9 reduces the voltage swing on the line between resistor R1 and resistor R16 by clamping the voltage appearing at the other terminal of resistor R16. In addition zener diode CR9 provides a stable voltage for driving the voltage divider network comprising resistors R9, R10 and R11. The function of this divider will be described in detail below.
Upon initial turn-on of the system, capacitor C1 is discharged. Therefore, initially the voltage across zener diode CR2 is less than its reverse breakdown voltage. Therefore, no signal is applied to the base of the transistor Q3. Transistor Q3 is thus turned off. This has two effects. Firstly, a voltage derived from the voltage source is applied to the noninverting input terminal of operational amplifier A1 via diode CR1 and resistors R1 and R4. Diode CR3 is provided to discharge capacitor C2 when power is off. Because there is no charge stored upon capacitor C2 initially, the noninverting input terminal of operational amplifier A1 is at a greater voltage than its inverting input terminal. Thus, the output of operational amplifier A1 is driven to the supply voltage. This applies a base current through R3 to transistor Q1 turning on lamp L1. The output of operational amplifier A1 is also applied to one input of NOR gate G2 thereby causing the output of NOR gate G2 to be a logical low. Secondly, because transistor Q3 is turned off, a current derived from the supply voltage is applied to the time constant circuit composed of capacitor C6 and resistor R8 through diode CR11. This places an initial charge into capacitor C6 which places a logical high signal on one input of NOR gate G1. This forces the output of NOR gate G1 to be a logical low. Thus the inital period during which transistor Q3 is turned off serves to initialize the logical states of both NOR gates G1 and G2.
After the power has been applied to the circuit for a short period of time, capacitor C1 charges to a voltage greater than the reverse breakdown voltage of zener diode CR2. This causes a current to flow through the back biased zener diode CR2 and resistor R2 to ground. This places a base voltage on transistor Q3, thereby turning this transistor on. Immediately thereafter one end of resistor R6 is grounded through transistor Q3 and diode CR11 is reverse biased. At this time, operational amplifier A1 begins to function as a timer in a manner which will be described in further detail below.
After the initialization of NOR gates G1 and G2 caused by the initial off period of transistor Q3, both NOR gates G1 and G2 apply logical low signals to the inputs of NOR gate G3. This causes the output of NOR gate G3 to be a logical high. This signal is applied to the base of transistor Q2 thereby turning this transistor on to supply current through temperature sensitive resistance element S1 and the parallel combination of resistor R15 with the resistors R13 and R14. Operational amplifier A2 serves to control the amount of electric power flowing through transistor Q2. A voltage reference is provided by the combination of zener diode CR9 and the resistance divider network comprised of resistors R9, R10 and R11. This circuit provides a predetermined voltage at the node between resistors R9 and R10 which is applied to the noninverting input of operational amplifier A2. The inverting input of operational amplifier A2 is connected to the node between the emitter of transistor Q2 and temperature sensitive resistance element S1. Operational amplifier A2 thus controls the base bias applied to transistor Q2 through diode CR6 in order to keep the voltage at the node between the emitter of transistor Q2 and temperature sensistive resistance element S1 at a value very close to the voltage applied to the noninverting input of operational amplifier A2.
Temperature sensitive resistance element S1 and resistor R15 from a sensor network such as sensor network 305 illustrated in FIG. 5. The node between temperature sensitive resistance element S1 and resistor R15 is connected to the noninverting input of operational amplifier A4 which serves as a comparator.
The temperature reference circuit includes operational amplifier A3, diode CR5, capacitor C5 and resistor R12. The sensor network node is connected to one end of a voltage divider circuit including resistor R13 and resistor R14 which form the reference network 306 illustrated in FIG. 5. Upon initial turn on of transistor Q2, the voltage appearing at the sensor node is a measure of the initial temperature of temperature sensitive resistance element S1. A percentage of this voltage is applied to the noninverting input of operational amplifier A3 through the reference network. Diode CR4 is provided to discharge capacitor C5 when power is off. Because capacitor C5 is initially discharged, the output of operational amplifier A3 is driven to the positive supply voltage. This output of operational amplifier A3 serves to charge capacitor C5 through diode CR5 until the voltage on capacitor C5 equals the voltage at the reference network node. As temperature sensitive resistance element S1 begins to heat, the voltage on the sensor network node begins to drop (see FIG. 6). Thus, the voltage applied to the noninverting input of operational amplifier A3 drops to the predetermined percentage of this reduced sensor node voltage. This drop causes the output of operational amplifier A3 to drop to ground. Ordinarily, this drop in voltage would serve to discharge capacitor C5, thus reducing the voltage applied to the inverting input of operational amplifier A3 until it equals the voltage of the reference network node. However, when the output of operational amplifier A3 drops below the voltage stored on capacitor C5, the diode CR5 is reverse biased and capacitor C5 cannot be discharged in this manner. Instead, the charge stored in capacitor C5 is discharged through resistor R12 to the reference voltage appearing at the node between resistors R10 and R11. The resistance of resistor R12 is selected to be so much greater than the resistance of resistors R10 and R11 that current flowing through resistor R12 has little effect upon the voltage at this node. Thus, the voltage on capacitor C5 is initially a fixed percentage of the temperature dependent signal appearing at the node of the sensor network and decreases in the manner illustrated in FIG. 6. Operational amplifier A4 serves as the comparator. The noninverting input is connected to the sensor network node and thus has the temperature dependent signal applied thereto. The inverting input of operational amplifier A4 is connected to capacitor C5 and thus has the temperature reference signal applied thereto. Initially the temperature reference signal is a predetermined percentage of the temperature dependent signal (see FIG. 6), and thus the output of operational amplifier A4 is driven to the positive supply voltage. This serves to charge capacitor C4 to the positive supply voltage. This signal is in turn applied to one input of NOR gate G1.
The timer function of operational amplifier A1 and its associated circuitry will now be described in detail. After the initial charging of capacitor C1, transistor Q3 is turned on. This serves to ground one end of resistor R6, thus forming a voltage divider circuit including resistors R4 and R6. The voltage at the junction of these resistors, which is fixed percentage of the supply voltage, is fed to the noninverting input of operational amplifier A1. Capacitor C2 is connected to the inverting input of operational amplifier A1. Because capacitor C2 is initially discharged, the voltage applied to the noninverting input terminal of the operational amplifier is greater than the voltage applied to the inverting input terminal upon initial power up. Therefore, the output of operational amplifier A1 is driven to the positive supply voltage. As explained above, this has the effect of applying a base bias current to transistor Q1 through resistor R3 thereby turning on lamp L1. In addition, the output of operational amplifier A1 is applied to NOR gate G2 thereby forcing the output of NOR gate G2 to a logical low. In addition, in response to the logical state initiation function described above, the output of NOR gate G1 is also forced to a logic low. These two outputs are applied to the inputs of NOR gate G3. This forces the output of NOR gate G3 to a logical high, thereby turning on transistor Q2 and applying power to the temperature sensitive resistance element S1.
While the circuit remains in this state, the voltage applied to the noninverting input terminal of operational amplifier A1 is determined by a voltage divider circuit including the parallel combination of resistors R4 and R5, which are connected between the power supply voltage and the noninverting input, and resistor R6, which is connected between the noninverting input and ground. Because the output of operational amplifier A1 has been driven to the positive supply of voltage, capacitor C2 is charged through resistor R7. In this state, because the output of NOR gate G2 is a logical low condition, diode CR11 is back biased and therefore has no effect upon the charging of capacitor C2. This charging process will continue until capacitor C2 is charged to a voltage greater than the voltage applied to the noninverting input of operational amplifier A1 via the voltage divider circuit. In this state, the output of operational amplifier A1 switches to become ground. Thus, operational amplifier A1 provides a timed output, whose length of time is set by the length of time it is required to charge capacitor C2 to the voltage set upon the noninverting input of operational amplifier A1 via the voltage divider circuit.
In the case in which the temperature sensitive resistance element S1 is covered by oil, the temperature dependent signal is always greater than the temperature reference signal throughout the predetermined interval set by the timing function described above (see FIG. 6). In such a case, the output of operational amplifier A4 remains at the positive supply voltage throughout the interval set by operational amplifier A1 and its associated circuitry. Thus, capacitor C4 is fully charged to the positive supply voltage when the output of operational amplifier A1 switches from the positive supply voltage to ground. When the output switching of operational amplifier A1 occurs, a bias current is no longer applied to transistor Q1. As a result, lamp L1 is turned off. In addition, a logical low signal is applied to one input of NOR gate G2. Because NOR gate G1 also applies a logical low signal to the other input of NOR gate G2, the output of NOR gate G2 switches to a logical high. This has the effect of changing the output state of NOR gate G3 to a logical low state. Therefore, a base bias current is no longer applied to the input of transistor Q2 (note that no bias current can come from operational amplifier A2 because diode CR6 blocks any such current), therefore power is no longer applied to the sensor network. The logical high input of NOR gate G2 is applied to one input of NOR gate G1, thereby insuring that the output of NOR gate G1 remains a logical low. In this state NOR gates G1 and G2 are latched, that is, they have achieved a stable state which is not altered by further operation of the circuit. Capacitor C4 is provided to insure that a logical high signal is applied to one input of NOR gate G1, thereby keeping its output at a logical low level, until a reliable latch up is achieved regardless of the output state of the comparator operational amplifier A4. The logical high output signal from NOR gate G2 is applied to capacitor C2 through the now forward biased diode CR7. The voltage divider resistors R4, R5 and R6 are selected to insure that the voltage applied to the noninverting input of operational amplifier A1 in this state is always less than the thus achieved voltage on capacitor C2. Therefore, the output of operational amplifier A1 remains pinned to ground and lamp L1 remains off. Thus when the level of oil in the engine crankcase is above the position of temperature sensitive resistance element S1, lamp L1 lights during the heating period and is then turned off. Thus no low oil level signal warning is generated.
When the oil level in the crankcase is below the position of temperature sensitive resistance element S1, then some time during the interval set by the timer function the temperature dependent signal falls below the temperature reference signal (see FIG. 6). Thus some time before capacitor C2 is charged to the voltage applied to the noninverting input of operational amplifier A1 and while the output of operational A1 is held at the power supply voltage, the output of operational amplifier A4 switches from the power supply voltage to ground. This discharges capacitor C4, thus applying a logical low signal to the associated input of NOR gate G1. Because the output of operational amplifier A1 remains at the positive supply voltage, a logical high is applied to one input of NOR gate G2, thereby forcing its output to a logical low state. This logical low is applied to a second input of NOR gate G1. After the initial power up signal applied to capacitor C6, this capacitor is discharged through resistor R8. Each of the three inputs to NOR gate G1 are logical lows and therefore the output of NOR gate G1 becomes a logical high. This logical high output is applied to one input of NOR gate G2, thereby forcing its output to a logical low. In addition, this output is also applied to one input of NOR gate G3, forcing the output of NOR gate G3 to a logical low and turning off sensor power through transistor Q2. Capacitor C5 is charged to the logical high output level of NOR gate G1 through transistor R17 and diode CR10. This insures that the voltage applied to the inverting input terminal of operational amplifier A4 is always greater than the voltage applied to the noninverting input terminal, thus assuring that capacitor C4 is always discharged and a logical low signal is applied to the associated input of NOR gate G1. Thus NOR gates G1 and G2 are latched in the opposite state from that described above in conjunction with the oil response of the sensor. In this state, with the output of NOR gate G2 a logical low, diode CR7 is back biased and therefore has no effect upon the function of the timing circuit including operational amplifier A1. In this state operational amplifier A1 is an oscillator. Operational amplifier A1 continues to produce an output signal equal to the supply voltage, thereby keeping lamp L1 turned on until capacitor C2 is charged to the voltage applied to the noninverting input via the divider circuit. As described above, at this time the output of operational amplifier A1 switches to ground thereby turning off lamp L1. This grounding of the output of operational amplifier A1 switches one terminal of resistor R5 from the positive supply voltage to ground. This has the effect of switching resistor R5 from being in parallel with resistor R4 to being in parallel with resistor R6. The voltage applied to the noninverting input of operational amplifier A1 is thus switched to a lower voltage as defined by the new divider circuit. Because capacitor C2 is charged to a voltage greater than this new reference voltage, the output of operational amplifier A1 remains grounded. Capacitor C2 is then discharged to the grounded output voltage of operational amplifier A1 through resistor R7. This discharging process continues until the voltage across capacitor C2 falls below the new reference voltage applied to the noninverting input. When this occurs, the output of operational amplifier A1 is again switched to the positive supply voltage. This switches resistor R5 from being in parallel with resistor R6 to being in parallel to resistor R4, thereby raising the divider voltage applied to the noninverting input to the initial level. As before, capacitor C2 is charged toward this new reference voltage through the output voltage applied to one end of resistor R7. As a consequence, the output of operational amplifier A1 periodically switches from the positive supply voltage to ground and back in synchronism with the charging and discharging of capacitor C2. Thus lamp L1 flashes on and off giving an indication that the level of oil in the crankcase is below the position of temperature sensitive resistance element S1.
As illustrated in FIG. 5, the circuit illustrated in FIG. 7 also includes a low voltage protector. This low voltage protector operates in conjunction with the previously described circuit including zener diode CR2, resistor R2 and transistor Q3. Any time the supply of voltage drops to the extent that the charge stored in capacitor C1 has a voltage less than the reverse breakdown voltage of zener diode CR2, transistor Q3 is turned off for lack of base bias current. As a result, resistor R6 is open circuited and therefore the the positive supply voltage is supplied to the noninverting input terminal of operational amplifier A1. This prevents the timer from ending its predetermined period of time during a low voltage state because capacitor C2 cannot charge to a voltage greater than the supply voltage less the forward bias voltage drop across diode CR3. In addition, diode CR11 applies a small current to capcitor C6. As a result, a logical high is applied to one input of both NOR gates G1 and G2. Thus the latch circuit is held in its initial state and is prevented from being responsive to any change in the output of the comparator operational amplifier A4. This circuit is employed because in the automotive application contemplated for the circuit illustrated in FIG. 7, the electrical power supply has occasional periods of low voltage. These low voltage periods could trigger a false low oil latching condition because the temperature dependent signal from the sensor network may fall below the temperature reference signal stored on capacitor C5 momentarily during such a low voltage condition. In order to prevent such an occurrence the timer circuit is inhibited from completing its predetermined timed interval and the latch circuit is prevented from entering either latch condition when a low supply voltage condition is detected.
FIG. 8 illustrates a second embodiment of the autoreferencing liquid level sensor of the present invention. Whereas the previous circuit determined the liquid level once when the power was first turned on, the circuit illustrated in FIG. 8 checks the liquid level repeatedly.
The circuit illustrated in FIG. 8 is highly similiar to the previous circuit illustrated in FIG. 7 except for some differences in the timing circuit and the logic circuit. In addition, the circuit illustrated in FIG. 8 does not include a low voltage detector. Upon initial application of power to the circuit, a percentage of the power supply voltage is supplied to the noninverting input of operational amplifier A1 through the divider circuit composed of resistors R4 and R6. Because capacitor C2 is initially discharged, the voltage applied to the noninverting input terminal of operational amplifier A1 is greater than the voltage applied to the inverting input terminal. Therefore, the output of operational amplifier A1 is driven to the positive supply voltage. This applies the logical high signal to one input of NOR gate G2 forcing its input to assume a logical low state. An initial high level input signal is applied to one input of NOR gate G1 from the output of operational amplifier A1 through capacitor C3. Because the outputs of both NOR gates G1 and G2 are logical low signals, these two signals when applied to the inputs of NOR gate G3 causes a logical high output from NOR gate G3. In the manner explained in detail above, transistor Q2 is turned on thereby initiating the sensor heating cycle. In addition, a logical low signal from NOR gate G1 is applied to the base of transistor Q1 through resistor R3. This turns transistor Q1 off therefore lamp L1 is not lit.
In the manner described in greater detail above, capacitor C2 is charged through resistor R7 up the voltage applied to the noninverting input of operational amplifier A1 set by the voltage divider network.
In the case in which the liquid level is above the position of temperature sensitive resistance element S1, then the output of operational amplifier A4 remains at the positive supply voltage throughout the heating period. This is because the temperature dependent signal is always greater than the temperature reference signal (see FIG. 6). When capacitor C2 charges up to the voltage applied to the noninverting input of operational amplifier A1, the output of operational amplifier A1 switches from the positive supply of voltage to ground. This discharges capacitor C3 and applies a logical low signal to one input of both NOR gates G1 and G2. Because NOR gate G1 still has a logical high signal applied to one of its inputs from operational amplifier A4, its output remains a logical low and lamp L1 remains off. However, the two inputs to NOR gate G2 and both now logical low signals. Therefore, the output of NOR gate G2 becomes a logical high signal. This logical high signal is applied to one input of NOR gate G3. Thus NOR gate G3 applies a logical low to the base of transistor Q2 turning off the power to the sensor network. In addition, the logical high output of NOR gate G2 is fed back to NOR gate G1, thereby latching these gates in a state which indicates the liquid level is above the position of the sensor. Capacitor C4 is provided to retain a logical high signal on one input NOR gate G1 until this latching is complete, regardless of the effect of turning off the sensor power on the output of operational amplifier A4.
As noted in detail above, with one input of resistor R6 grounded, the circuitry associated with operational amplifier A1 is an oscillator. Once the output of operational amplifier A1 has switched from the positive supply voltage to ground, the charge stored on capacitor C2 is discharged through resistor R7 to the newly set reference level applied to the noninverting input of operational amplifier A1 from the divider circuit. When this voltage, which is applied to the inverting input of operational amplifier A1, reaches the reference voltage, the output of operational amplifier A1 again becomes the positive supply voltage and capacitor C2 begins to charge to the newly set, higher reference voltage. This new output of operational amplifier A1 applies a logical high signal to the input of NOR gate G1 through the time constant circuit including capacitor C3 and resistor R8. At the same time, this output of operational amplifier A1 applies a logical high to one input of NOR gate G2, thus forcing its output to a logical low level. At this time NOR gate G3 receives two logical low signal inputs. Thus NOR gate G3 produces a logical high output turning on the sensor power via transistor Q2. The time constant of capacitor C3 and resistor R8 is selected so that a logical high signal is reliably applied to the associated input of NOR gate G1 until operational amplifier A4 produces its initial output signal which is equal to the positive supply voltage. This prevents the latch comprising NOR gates G1 and G2 from falsely latching in an improper state. As long as the temperature dependent signal never goes below the temperature reference signal, the circuit osciallates between the two states described above and lamp L1 is never lit.
In the case in which the liquid level is below the position of temperature sensitive resistance element S1, then at some time during each charging period of capacitor C2 the temperature dependence signal falls below the temperature reference signal (see FIG. 6). At this time the output of operational amplifier A4 goes to ground, thereby providing a logical low signal to the associated input of NOR gate G1. At this time the capacitor C3 has been fully charged to the supply voltage from the output of operational amplifier A1 thus no current flows through resistor R8, and therefore a logical low signal is also supplied to the input of NOR gate G1 associated with capacitor C3 and resistor R8. Because the output of NOR gate G2 is also a logical low signal, each of the inputs to NOR gate G1 is a logical low signal. Thus the output of NOR gate G1 becomes a logical high signal. This applies a base bias current to transistor Q1 through resistor R3, thus turning on lamp L1. In addition, this applies a logical high signal to one input of NOR gate G3, thus causing NOR gate G3 to produce a logical low output signal turning off the base bias current to transistor Q2 and thus the sensor power. Again because capacitor C3 is fully charged up to the positive supply voltage, the output of operational amplifier A1 has no effect upon the output of NOR gate G1. Thus NOR gates G1 and G2 are latched in a state indicating a low liquid level and lamp L1 is on. The logical state of NOR gates G1 and G2 is not changed when the output of operational amplifier A1 switches to ground when the charge on capacitor C2 reaches the reference voltage. During the time in which the charge on capacitor C2 is discharged through resistor R7 toward the new reference voltage in a manner fully described above, the logical states of NOR gates G1 and G2 remain unchanged and thus lamp L1 continues to be lit. When the voltage on capacitor C2 falls below the reference voltage on the noninverting input of operational amplifier A1, the output of operational amplifier A1 becomes the positive supply voltage. This output of operational amplifier A1 resets the logical states of NOR gates G1, G2 and G3 in a manner similar to that upon first turn on of the system. Thus a base bias is applied to transistor Q2, electrical power is applied to the sensor network and no base bias current is applied to transistor Q1 thus shutting lamp L1 off. This state continues until the temperature dependent signal again falls below the temperature reference signal in the manner described above. Thus in the case in which the liquid level is below the position of temperature sensitive resistance element S1, the lamp L1 flashes on and off with the length of the off period related to the length of time necessary for the temperature dependent signal from the heated sensor to cross the temperature reference signal. This flashing of the lamp can be clearly distinguished from the case in which the liquid is above the position of temperature dependent resistance S1 in which the lamp is never lit. | An autoreferencing liquid level sensing apparatus and method determines the presence of a liquid by observation of the convective cooling rate of a heated temperature sensor. The temperature measured by the temperature sensor is compared with an adapting temperature reference whose initial value is determined from the initial measured temperature and whose value increases during the heating at a rate proportional to the rate of heating of the temperature sensor and the initial temperature. This comparison enables discrimination of whether the convective cooling rate of the temperature sensor is above or below a predetermined level. Because the rate of convective cooling depends in large part on the thermal capacity of the fluid surrounding the sensor, the convective cooling rate determination allows discrimination of whether the temperature sensor is surrounded by a gas or a liquid, or surrounded by one of two immiscible liquids having differing thermal properties. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit of U.S. Provisional Application No. 61/427,549, filed Dec. 28, 2010, the contents of which are herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the present invention generally relate to an abrasive jet drilling assembly. More particularly, embodiments of the present invention relate to a resettable circulation tool for use in the abrasive jet drilling assembly.
[0004] 2. Description of the Related Art
[0005] In the oil and gas industry, a wellbore may be formed by using an abrasive jet drilling assembly. The abrasive jet drilling assembly typically includes a jetting drill device disposed on a drill string. The jetting drill device ejects a high velocity stream of drilling fluid which includes abrasive particles. The high velocity stream of drilling fluid erodes the rock adjacent the jetting drill device to form the wellbore. If the abrasive jet drilling assembly encounters a gas cake (e.g. gas pocket) while forming the wellbore, it is oftentimes necessary to circulate back through a circulation port of a circulation tool. There are circulation tools commercially available that enable a downhole circulation port to be opened from the surface. Current designs of such circulation tools are limited in their number of operation and function by dropping a ball, shearing a pin, or other method that precludes utilizing the circulating function for another event. Many tools function by dropping a ball or plug that impedes further flow as the circulation function is not reversible or resettable. Additionally, these circulation tools stay open without the ability to utilize the flow through the body of the circulation tool as per the initial (pre-deployed) condition. Therefore, there is a need for a resettable circulation tool for use in the abrasive jet drilling assembly.
SUMMARY OF THE INVENTION
[0006] The present invention generally relate to an abrasive jet drilling assembly. In one aspect, a resettable circulation tool for use in an abrasive jet drilling assembly includes an inner body having a first port in fluid communication with a bore; an outer body having a second port; and a cam member configured to move along one or more slots, wherein the bodies move relative to each other to selectively align and misalign the first port and the second port as the cam member moves along the slots.
[0007] In another aspect, a resettable circulation tool for use in an abrasive jet drilling assembly is provided. The resettable circulation tool includes an inner body having a first port in fluid communication with a bore. The resettable circulation tool further includes an outer body having slots formed on an inner surface, wherein the outer body includes a second port. Additionally, the resettable circulation tool includes a cam member configured to move along the slots of the outer body, wherein the bodies move relative to each other to selectively align and misalign the first port and the second port as the cam member moves along the slots.
[0008] In another aspect, a method of using a resettable circulation tool disposed in an abrasive jet drilling assembly is provided. The method includes the step of positioning a jetting drill device in the abrasive jet drilling assembly into contact with a portion of a wellbore. The method further includes the step of applying a first axial force and a first rotational force on the drilling assembly, thereby causing a first port and a second port in the resettable circulation tool to align. The method also includes the step of pumping fluid through the ports of the resettable circulation tool. The method further includes the step of applying a second axial force and a second rotational force on the drilling assembly, thereby causing the first port and the second port to misalign. Additionally, the method includes the step of pumping fluid through the resettable circulation tool and into the jetting drill device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0010] FIG. 1 is a view illustrating a resettable circulation tool in an abrasive jet drilling assembly.
[0011] FIG. 2 is a cross-section view illustrating the resettable circulation tool in the abrasive jet drilling assembly.
[0012] FIG. 3 is a cross-section view illustrating the resettable circulation tool.
DETAILED DESCRIPTION
[0013] The present invention generally relates to a resettable circulation tool for use in the abrasive jet drilling assembly. To better understand the novelty of the resettable circulation tool of the present invention and the methods of use thereof, reference is hereafter made to the accompanying drawings.
[0014] FIG. 1 is a view illustrating a resettable circulation tool 100 in an abrasive jet drilling assembly 200 . Generally, the abrasive jet drilling assembly 200 is used to form a wellbore by ejecting a high velocity stream of drilling fluid which includes abrasive particles. The abrasive jet drilling assembly 200 includes a jetting drill device 205 for ejecting the high velocity stream of drilling fluid. The abrasive jet drilling assembly 200 is connected to a drill string (not shown). The abrasive jet drilling assembly 200 further includes the resettable circulation tool 100 .
[0015] The resettable circulation tool 100 includes a plurality of circulation ports 105 that may be selectively opened during the drilling operation to circulate drilling fluid out of the drill string and then closed. The resettable circulation tool 100 could be operated multiple times during the drilling operation. The resettable circulation tool 100 is normally closed, and may optionally be provided with a shear pin safety system to prevent unwanted operation. The resettable circulation tool 100 is movable between a closed position (normal operation) and an opened position. In the opened position, fluid is circulated out from the resettable circulation tool 100 above the device 205 to eliminate a shot column. To move the resettable circulation tool 100 to the opened position from the closed position, a downward motion will allow the resettable circulation tool 100 to open and allow circulation, and remain in this position until a similar downward motion is utilized to close the resettable circulation tool 100 and resume the drilling operation. The resettable circulation tool 100 can be operated as often as required to accomplish the desired objectives during the drilling operation.
[0016] FIG. 2 is a cross-section view illustrating the resettable circulation tool 100 in the abrasive jet drilling assembly 200 . As shown, a bore 210 of the jetting drill device 205 is in fluid communication with a bore 110 of the resettable circulation tool 100 . During the drilling operation, drill fluid is pumped through the drill string through the bores 110 , 210 and then out of the jetting drill device 205 . The drill fluid includes abrasive particles that are configured to erode the rock to form the wellbore. The resettable circulation tool 100 in the closed position (e.g. normal operation) allows all of the drill fluid to flow though the bore 110 of the resettable circulation tool 100 . The resettable circulation tool 100 in the opened position allows substantially all of the drill fluid to flow though the circulation ports 105 of the resettable circulation tool 100 .
[0017] FIG. 3 is a cross-section view illustrating the resettable circulation tool 100 . The resettable circulation tool 100 generally includes an inner sub 130 and an outer sub 125 . Each sub 125 , 130 has the requisite connection member, such as a threaded connection, that is required to be placed above the jetting drill device 205 , and allows the subs 125 , 130 to be an extension of the jetting drill device 205 . The inner sub 130 has the sector control profile, such as slots, that allows the “ratcheting” function of the sub's operation. As set forth herein, cams 140 are installed into the outer sub 125 to provide the control of the ports 105 to either the opened position or the closed position. In one embodiment, there are three sets of cams 140 and profiles to allow strength to support the resettable circulation tool 100 function. In addition, there may also be a lock collar 160 that adds additional shear strength in tension operations. The outer sub 125 may optionally include shear pins with total WOB (Weight on Bit) loads from 9,500 lbs. to 20,000 lbs. to actuate the circulation function of the resettable circulation tool 100 for the first time.
[0018] The resettable circulation tool 100 is generally a two-position tool, which can be cycled from the closed position to the opened position and back again to the closed position any number of times. The resettable circulation tool 100 is cycled by a downward direction force, arrow 165 , with slight rotation in a first direction. In one embodiment, the first direction is toward the right. Re-pressurization (e.g. by restoring flow) pumps open the tool and open the circulating ports 105 of the resettable circulation tool 100 . In the event that this action needs to be reversed (e.g. moved to the closed position), the downward force 165 is once again applied with slight rotation in the first direction, and re-pressurizing to pump, the circulation ports 105 are closed.
[0019] The resettable circulation tool 100 allows numerous cycles from opened position to closed position as required during the drilling operation. In addition, there is no obstruction to flow in the bore 110 of the resettable circulation tool 100 as compared to current designs of circulation tools which require a ball or a plug to operate. Further, there are minimum maintenance requirements in the resettable circulation tool 100 other than grease flush during cleaning. In one embodiment, shear pins may be included to ensure a minimum operating force (e.g. downward force 165 ) prior to operation; however this feature would be single use only.
[0020] The resettable circulation tool 100 is installed in-line with the jetting drill device 205 (see FIG. 2 ), with appropriate connections and crossovers as required. The inlet 170 is the fluid inlet for the resettable circulation tool 100 and directly provides a flow path to the jetting drill device 205 through a crossover at the bottom. The only other flow ports are ports 105 , 155 .
[0021] During the operation of the resettable circulation tool 100 , the flow ports 105 are either closed or open. The resettable circulation tool 100 is operated by pressure acting as a spring and forcing the outer sub 125 to travel downward and stop. In one embodiment, low pressure operation of around 100 to 300 PSI is used.
[0022] The resettable circulation tool 100 includes cam 140 which drives the outer sub 125 through the slots 145 that control the positioning of the outer sub 125 relative to the inner sub 130 . In one embodiment, the slots 145 extend circumferentially around the inner sub 130 and axially along a substantial length thereof. In one embodiment, the slots 145 extend circumferentially around the outer sub 125 and axially along a substantial length thereof. The slots 145 include guides and shoulders (not shown) that are used to direct the cam 140 along a slot pathway. The slots 145 may include a plurality of longer length slots and a plurality of shorter length slots. In one embodiment, a shear pin 135 may be utilized to prevent the movement of the cam 140 in the slots 140 unless sufficient force, such as 10,000 lbs. to 35,000 lbs., is applied downward.
[0023] The slots 145 have been arranged to have the resettable circulation tool 100 function with applied downward force (e.g. 165 ), but the resettable circulation tool 100 is recommended to have right-hand torque when setting down. The slots 145 provide up and down function but will resist rotating the outer sub 125 relative to the inner sub 120 . The slots 145 provide different slot lengths for open or closed positions. The open position is longer, providing the additional length to open the flow ports 105 , 155 to the bore 110 . In one embodiment, the slot configuration has three dual function segments in the cam surfaces.
[0024] In the closed position as shown in FIG. 3 , flow cannot exit the resettable circulation tool 100 , and the flow is directed into the jetting drill device 205 . If outboard circulation is desired, the force 165 (e.g. WOB) is applied with a slight torque in the first direction. In turn, the cam 140 is reset into a longer length slot of the slots 145 , so that when the pressure is applied to the resettable circulation tool 100 , it will cycle to the opening of the flow ports 105 . The resultant area is 6 times the nozzle area with a corresponding pressure drop. In other words, to move the resettable circulation tool 100 to the opened position, the resettable circulation tool 100 is cycled by a downward direction force, arrow 165 , with slight rotation in a first direction, which causes the cam 140 to move along the guides of the slots 145 and stop at one of the shoulders. At this point, the inner port 155 of the inner sub 120 is aligned with the outer port 105 of the outer sub 125 , and fluid is allowed to exit the resettable circulation tool 100 .
[0025] To move the resettable circulation tool 100 from the opened position to the closed position, substantially the same set down force 165 (e.g. WOB) is applied with a torque in the first direction which allows the outer sub 125 to rotate to a shorter length slot in the slots 145 , and when pressurized, the resettable circulation tool 100 will cycle to the closed position with the flow ports 105 closed again. In other words the inner port 155 of the inner sub 120 is misaligned with the outer port 105 of the outer sub 125 , and fluid is prevented from exiting the resettable circulation tool 100 . Repetition of the same downward action will reset the resettable circulation tool 100 to either the closed or open position as desired. The resettable circulation tool 100 alternatively either opens or closes during activation.
[0026] The resettable circulation tool 100 includes a first seal 115 and a second seal 120 between the inner sub 120 and the outer sub 125 . The seals 115 , 120 are configured to prevent the leakage of fluid between the subs 120 , 125 . The seals 115 , 120 also seal ports 105 , 155 and provide the necessary seal and backup for 10,000 PSI operation for multiple cycles.
[0027] In another embodiment, the threaded collar 160 may be used for tensile strength. Specifically, the threaded collar 160 is used at the bottom of the inner sub 120 to retain the integrity of the resettable circulation tool 100 if the cams malfunction.
[0028] In addition to circulating fluid, the resettable circulation tool 100 may be used to allow for drill string drainage (after shot is circulated out) and subsequent (dry string) to aid in drill string servicing when coming out of the hole. This is enabled by opening the ports 105 in a similar manner, as described herein, for drainage of the drill string.
[0029] The resettable circulation tool 100 may be furnished as a custom tool to match the threaded connections of the jetting drill device 205 and the desired upper connection, as well as larger sizes of jetting drill devices.
[0030] The simplicity and ease of maintenance of the resettable circulation tool 100 are maintained by removing the threaded collar 160 and the three cam pins 140 . Larger resettable circulation tools may have more cam pins. Once removal of the cam pins 140 has been accomplished, the inner sub 120 is removed from the outer sub 125 for cleaning and seal replacement.
[0031] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | The present invention generally relates to an abrasive jet drilling assembly. In one aspect, a resettable circulation tool for use in an abrasive jet drilling assembly is provided. The resettable circulation tool includes an inner body having a first port in fluid communication with a bore. The resettable circulation tool further includes an outer body having a second port. Additionally, the resettable circulation tool includes a cam member configured to move along one or more slots, wherein the bodies move relative to each other to selectively align and misalign the first port and the second port as the cam member moves along the slots. In another aspect, a method of using a resettable circulation tool disposed in an abrasive jet drilling assembly includes moving the first and second ports into and out of alignment. | 4 |
INCORPORATION BY REFERENCE
The present patent application claims priority to U.S. patent application Ser. No. 12/655,206 titled METHOD AND APPARATUS FOR TREATING FLUID COLUMNS, filed on Dec. 26, 2009, the entire contents of which are hereby expressly incorporated herein by reference.
BACKGROUND OF THE INVENTION
The instant invention relates to a method and apparatus for treating fluid columns to prevent the formation of scale and other flow restricting deposits within conduits utilized in the transmission of fluids. The instant method and apparatus may also be utilized to extract deposits from the surfaces of conduits and other components of fluid transmission systems, accelerate the separation of contaminants from a fluid and reduce the amount of chemicals required for the maintenance, treatment and processing of many fluids.
Thermal exchange systems comprising components such as boilers, heat exchangers and cooling towers utilize water as a heat transfer medium. Suspended and dissolved minerals precipitate out of the water and accumulate as deposits of scale on the surfaces of thermal exchange system components and restrict the flow of water, act as insulation that inhibits heat transfer from one surface to another, impede the operation of equipment and increase energy consumption as the fouled systems lose efficiency and labor to meet operational parameters. Fouled heat exchange systems must undergo descaling processes to recover lost productivity and reduce energy consumption at a significant expense, not only for the cost of cleaning system components but also for lost productivity while a facility is out of service as the fouled thermal exchange system is descaled.
Chemical treatment is a common means of controlling scale, corrosion, algae, bacteria and other biological contaminants in thermal exchange systems and is also commonly used to remove suspended or dissolved solid contaminants from process water, make-up water, industrial storm water and wastewater. Utilization of chemicals is costly, requires the storage, handling and dispensing of dangerous substances and poses increasing environmental concerns. As chemicals, minerals and other contaminants accumulate in thermal exchange systems, the water becomes unsuitable for continued use and a fresh supply of water is required for the ongoing operation of such systems. Contaminant laden water from such systems typically incurs large surcharges for wastewater disposal due to the treatment needed to render the water suitable for discharge into the environment.
In petroleum production, water, paraffin and minerals entrained in petroleum production fluids extracted from oil producing formations are separated from marketable oil by bulk recovery apparatus. Water extracted from crude oil is typically returned to the formation while recovered petroleum containing residual amounts of water and contaminants is transported to a refinery for processing into commodities. Over time, deposits of scale and other contaminants form within the separation equipment used to remove water from oil, conduits utilized to return water to the formation and pipelines used to transport crude oil to a refinery; resulting in restricted fluid flow, limited capacity of fluid transmission systems and the deterioration of pumps, valves, meters and other equipment. Productivity is lost when costly physical cleaning and chemical remediation are required to restore full flow to petroleum production and transmission systems. Refineries, as well as other industrial complexes, are constantly challenged with remediation of hydrocarbon contaminants that migrate into storm water and wastewater systems.
Prior art apparatus use a length of wire coiled around the outer surface of a pipe to form an antenna that is then energized with electrical energy switched on and off at a frequency of 2 kHz-20 kHz in an effort to replace chemical treatment. Prior art apparatus are challenged by a number of deficiencies. Energizing an antenna with electrical energy continuously switched on and off at a frequency of 2 kHz-20 kHz generates a signal that radiates from the coiled wire, and because the signal radiates from the antenna only a limited area of the flow channel within the pipe receives the signal. Prior art apparatus attempt to treat pipes greater than 1″ in diameter by amplifying their signals to treat a broader cross section within the pipe. However, amplification merely results in the signal radiating farther from the coiled wire and typically fails to treat a broader cross section of the flow channel within larger diameter conduits.
Further, such prior art devices fail to shield the signals they generate and are susceptible to interference from stronger signals of other devices that can limit the efficiency of the fluid treatment they provide. The unshielded signals of prior art devices also radiate from the coil and may interfere with radio controlled devices, such as apparatus utilized in telemetering data and equipment.
SUMMARY OF THE INVENTION
The instant invention includes a method of providing fluid treatment, comprising the steps of providing a fluid treatment vessel defining a fluid impervious boundary wall with an inner surface and having a fluid input port and a fluid output port, the inner surface of said fluid impervious boundary wall establishing a fluid treatment chamber; providing at least one transducer to direct at least one pulsed electromagnetic wave proximate at least one distinct region within the fluid treatment chamber, each at least one transducer comprising at least one length of electrical conducting material having a first conductor lead and a second conductor lead and forming at least one antenna; providing at least one electrical energizing unit having a capacity to produce at least one distinct programmable output of electrical energy continuously switched on and off at a pulsed repetition rate to establish at least one pulsed electrical signal; providing at least one shielding material member to restrict radiation of the at least one pulsed electrical signal, said at least one shielding material member further reducing external interference with said at least one pulsed electrical signal; providing means for deploying the at least one transducer within the fluid treatment chamber; and providing means for deploying the at least one shielding material member to restrict propagation of the at least one pulsed electrical signal. The instant method further comprises connecting the conductor leads of the at least one transducer to the at least one electrical energizing unit to energize said at least one transducer with at least one pulsed electrical signal and thereby produce at least one pulsed electromagnetic wave directed proximate at least one distinct region within the fluid treatment chamber and establishing at least one region of pulsed fluid treatment within said fluid treatment chamber; introducing a feed stream comprising a fluid column receptive to pulsed fluid treatment to the fluid inlet port of the fluid treatment vessel to establish a flow of the fluid to be treated through the fluid treatment chamber; directing the fluid to pass through at least one region of pulsed fluid treatment; and discharging the feed stream exiting from the fluid outlet port of the fluid treatment vessel as a processed fluid.
The instant method of fluid treatment may include one or more of the steps of dispersing a supply of at least one fluid treatment chemical into the feed stream, directing the feed steam to pass through at least one contaminant separation process or directing the feed steam to pass through at least one fluid flow conditioning process.
The instant invention may be utilized to improve the efficiency of apparatus utilized in solid/liquid phase separation or liquid/liquid separation (such as oil/water separation) and may also be effective in controlling and eliminating many biological contaminants. Unlike chemical treatment, the instant invention typically will not over treat or under treat a feedstock and requires little monitoring or adjustment for effective fluid treatment. Suspended and dissolved contaminants within many fluid columns may be rendered non-adhesive and inhibit their accumulation as deposits within conduits and on the surfaces of equipment. The instant invention may be utilized in single pass fluid treatment applications and closed-loop fluid transmission systems.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate the preferred embodiments of the invention in which:
FIG. 1 shows the configuration of the instant invention in a fluid treatment system; and
FIG. 2 shows the transducers of the instant invention disposed within the fluid treatment chamber of a fluid treatment vessel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The instant invention includes an apparatus providing fluid treatment, comprising a fluid treatment vessel defining a fluid impervious boundary wall with an inner surface and having a fluid input port and a fluid output port, the inner surface of said fluid impervious boundary wall establishing a fluid treatment chamber; at least one transducer to direct at least one pulsed electromagnetic wave proximate at least one distinct region within the fluid treatment chamber, each at least one transducer comprising at least one length of electrical conducting material having a first conductor lead and a second conductor lead and forming at least one antenna; means for deploying the at least one transducer within the fluid treatment chamber; at least one electrical energizing unit coupled to the at least one transducer, said at least one electrical energizing unit providing at least one distinct programmable output of electrical energy continuously switched on and off at a pulsed repetition rate to establish at least one pulsed electrical signal to energize the at least one transducer and thereby produce at least one pulsed electromagnetic wave directed proximate at least one distinct region within the fluid treatment chamber; at least one shielding material member having a capacity to restrict radiation of the at least one pulsed electrical signal, said at least one shielding material member further reducing external interference with said at least one pulsed electrical signal; and means for deploying the at least one shielding material member to restrict propagation of the at least one pulsed electrical signal.
A feed stream receptive to fluid treatment may be directed to make a single pass through the pulsed fluid treatment device or may be directed to make at least one additional pass through the pulsed fluid treatment device. In some applications, a feed stream may be directed to pass through the pulsed fluid treatment device as a continuous flow of fluid, but in other instances a feed stream may be directed to flow into an embodiment of the fluid treatment vessel comprising a collection basin, settling tank, retention pond or similar type of reservoir to allow for gravity separation of suspended and dissolved solids in the feed stream prior to discharging processed fluid from the fluid treatment vessel. At least one transducer may be deployed within a collection basin, settling tank or retention pond to direct pulsed fluid treatment to fluid retained within a reservoir.
FIG. 1 shows a configuration of the instant invention in a fluid treatment system wherein a feed stream receptive to fluid treatment introduced to port 1 may be directed to pass through at least one pulsed electromagnetic wave within fluid treatment vessel 2 . First and second conductor leads 4 of a transducer disposed in the fluid treatment vessel are shown connected to electrical energizing unit 3 . Shielding material member 5 is shown enclosing the fluid treatment vessel and electrical energizing unit to restrict propagation of the at least one pulsed electrical signal produced by the electrical energizing unit and at least one pulsed electromagnetic wave produced by the at least one energized transducer. The processed fluid may then be discharged from port 6 in a single pass application or directed to apparatus 7 of a closed-loop system to allow for additional circulation through the fluid treatment devices. A processed fluid may also be directed to collection basin 8 for additional processing of the fluid.
The electrical energizing unit of the instant pulsed fluid treatment device may establish a pulsed electrical signal having a direct current component. This may be accomplished through a switching sequence comprising initially switching an output of electrical energy to an “on” state during a first time interval to energize at least one transducer with electrical energy flowing from the first conductor lead to the second conductor lead, switching said first output of electrical energy to an “off” state to interrupt the energizing of said at least one transducer, switching an output of electrical energy to the “on” state during a second time interval to energize said at least one transducer with electrical energy flowing from the first conductor lead to the second conductor lead, and switching said second output of electrical energy to the “off” state to interrupt the energizing of said at least one transducer and causing the switching sequence to repeat at a repetition rate. The first and second time intervals and the repetition rate may be substantially constant or one or more of the first and second time intervals and the repetition rate may be variable.
The electrical energizing unit may also establish a pulsed electrical signal having an alternating current component. This may be accomplished through a switching sequence comprising initially switching an output of electrical energy to an “on” state during a first time interval to energize at least one transducer with electrical energy flowing between the first conductor lead to the second conductor lead in a first direction, switching said first output of electrical energy to an “off” state to interrupt the energizing of said at least one transducer, reversing the direction of the flow of electrical energy, switching an output of electrical energy to the “on” state during a second time interval to energize said at least one transducer with electrical energy flowing between the first conductor lead to the second conductor lead in a second direction, switching said second output of electrical energy to the “off” state to interrupt the energizing of said at least one transducer and causing the switching sequence to repeat at a repetition rate. The first and second time intervals and the repetition rate may be substantially constant or one or more of the first and second time intervals and the repetition rate may be variable.
Said electrical energizing unit establishing a pulsed electrical signal having an alternating current component may energize at least one transducer through a switching sequence comprising initially energizing said at least one transducer during a first time interval with electrical energy flowing between the first conductor lead to the second conductor lead in a first direction, switching the direction of the flow of electrical energy and energizing said at least one transducer during a second time interval with electrical energy flowing between the first conductor lead to the second conductor lead in a second direction and causing the switching sequence to repeat at a repetition rate. The first and second time intervals and the repetition rate may be substantially constant or one or more of the first and second time intervals and the repetition rate may be variable.
The electrical energizing unit may have the capacity to vary the direction and amplitude of the pulsed electrical signal over the operation range of a transducer to more evenly distribute energy throughout the fluid treatment chamber. The amplitude of the pulsed electrical signal may be substantially constant or variable. The electrical energizing unit may generate a variety of waveforms including, but not limited to, square waves, sine waves, saw tooth waves, triangle waves or composite waves.
At least one of the time interval, repetition rate, waveform, wavelength, amplitude or direction of the output of electrical energy may be established according to one or more of the composition of the fluid, material comprising the fluid treatment vessel, dimensions of the fluid treatment vessel, embodiment of the at least one transducer, resistance or impedance of the at least one transducer, means for deploying the at least one transducer, material comprising the at least one shielding material member and configuration of the at least one shielding material member.
An electrical energizing unit may energize a single transducer with a pulsed electrical signal or energize a first transducer and a second transducer with a pulsed electrical signal. The electrical energizing unit may provide a plurality of distinct programmable outputs of electrical energy with each output of electrical energy establishing a distinct pulsed electrical signal, wherein a first pulsed electrical signal may energize a first transducer and a second pulsed electrical signal may energize a second transducer. The first pulsed electrical signal may have electrical characteristics substantially equivalent to the second pulsed electrical signal or the first pulsed electrical signal may have electrical characteristics distinct from the second pulsed electrical signal.
In some applications, it may be advantageous to utilize a first electrical energizing unit to energize a first transducer with a first pulsed electrical signal and a second electrical energizing unit to energize a second transducer with a second pulsed electrical signal. The second electrical energizing unit may establish a second pulsed electrical signal having electrical characteristics substantially equivalent to the first pulsed electrical signal or the second electrical energizing unit may establish a second pulsed electrical signal having electrical characteristics distinct from the first pulsed electrical signal.
As shown in FIG. 2 , the preferred means of deploying the at least one transducer is to dispose the at least one transducer within the fluid impervious boundary wall of the fluid treatment vessel. Fluid treatment vessel 10 is shown enclosing antenna 11 in substantially concentric surrounding relation with the transducer being coaxially disposed and radially spaced apart from the inner surface of the fluid impervious boundary wall of the fluid treatment chamber.
The at least antenna may be directional or omni-directional in function and enclosed within a housing to protect said antenna from corrosive feedstocks and debris in a feed stream that could affect the performance of the antenna or destroy the antenna.
A feed stream comprising a fluid column receptive to pulsed fluid treatment may be introduced to fluid input port 10 a of the fluid treatment vessel to establish a flow of the fluid to be treated through the fluid treatment chamber, then directed to pass through at least one pulsed electromagnetic wave emitted by the antenna. The feed stream may then be discharged from fluid output port 10 b of the fluid treatment vessel as a processed fluid.
Fluid treatment vessel 10 is also shown enclosing antenna 12 in substantially eccentric surrounding relation with the transducer disposed proximate and spaced apart from inner surface of the fluid impervious boundary wall of the fluid treatment chamber, and enclosing antenna 13 in substantially eccentric surrounding relation with the transducer disposed in fluid communication inner surface of the fluid impervious boundary wall of the fluid treatment chamber. Antenna 14 is shown extending through the fluid impervious boundary wall of the fluid treatment vessel and into the fluid treatment chamber substantially orthogonal to the direction of the flow of fluid through the fluid treatment chamber.
In some applications, it may be advantageous to deploy an embodiment of the transducer of the at least one transducer substantially diagonal to the direction of the flow of fluid through the fluid treatment chamber. First and second conductor leads 11 a and 11 b , 12 a and 12 b , 13 a and 13 b or 14 a and 14 b of a transducer may be connected to at least one electrical energizing unit to energize a transducer with at least one pulsed electrical signal and thereby produce pulsed fluid treatment in at least one region within the fluid treatment chamber.
The fluid treatment vessel, at least one transducer and at least one electrical energizing unit may be enclosed within a single shielding material member to restrict the radiation of the at least one pulsed electrical signal, or a shielding material member may enclose any combination the fluid treatment vessel, at least one transducer and at least one electrical energizing unit. Each of the fluid treatment vessel, the at least one transducer and the at least one electrical energizing unit may be enclosed within distinct and dedicated shielding material members so that each component may be individually shielded.
A fluid treatment vessel comprising a material having a capacity to restrict propagation of the at least one pulsed electrical signal may form a shielding material member for the at least one transducer. In such instances, the inner surface of the fluid impervious boundary wall of the fluid treatment vessel may establish a resonant chamber for the at least one pulsed electromagnetic wave.
A length of coaxial cable, comprising an external braid of wire encircling at least one internal strand of electrical conducting material in substantially concentric surrounding relation, may be utilized as a conductor lead of said transducer and connected to the at least one shielded electrical energizing unit, wherein the external braid of wire forms a shielding material member to restrict the radiation of the at least one pulsed electrical signal transmitted through the at least one internal strand of electrical conductor. Other combinations and embodiments of shielding material members may be utilized.
A treated fluid may receive additional pulsed fluid treatment downstream of the instant invention. In some instances, at least one antenna may be disposed in fluid communication with the outer surface of a conduit promoting the flow of a processed fluid to provide additional pulsed fluid treatment. In other applications, a processed fluid may be retained in a collection basin, settling tank, retention pond or similar type of reservoir to allow for gravity separation of suspended and dissolved solids in the processed fluid column. At least one antenna may be deployed within said reservoir to direct additional pulsed fluid treatment to the processed fluid retained within the collection basin prior to discharging the fluid.
Directing a feed stream through at least one pulsed electromagnetic wave may neutralize the electrical charges of many suspended and dissolved solid contaminants in the feedstock, render them non-adhesive and enhance the clarification of the fluid. Water utilized as a heat transfer medium in thermal exchange systems, such as boilers, heat exchangers or cooling towers, may be directed through at least one pulsed electromagnetic wave to retard the formation of scale and other heat insulating deposits in such thermal exchange systems. Directing seawater through the pulsed fluid treatment of the instant invention may improve the efficiency of desalination and reverse osmosis systems. The instant invention may also be utilized to reduce the surface tension of irrigation water to allow for better penetration of the soil to improve feeding of the roots of plants.
Coagulating chemicals are typically used to neutralize the electrical charges of particles suspended in a fluid column. Directing a feedstock to pass through the instant invention may cause suspended and dissolved contaminants in a feed stream to be repelled from the fluid and facilitate removal of solid contaminants, and may thereby reduce the amount of coagulants required for adequate processing of a fluid. Flocculants are commonly injected into wastewater sludge upstream of dewatering equipment and mixed into a feedstock to promote the aggregation of finely dispersed solids suspended in wastewater into particles large enough to be removed by physical separation. Pretreatment of wastewater may result in a reduction of the amount of chemical required for processing while simultaneously generating drier solids and clearer filtrate discharged from dewatering equipment.
Energizing the at least one transducer with certain pulsed electrical signals may generate alternating positive and negative pressure waves in a feed stream that tend to tear fluids apart and create vacuum cavities forming micron-size bubbles. As these bubbles continue to grow under the influence of the alternating positive and negative pressure waves, they reach a resonant size where they then collapse, or implode, under a force known as cavitation. Imploding bubbles form jets of plasma having extremely high temperatures that travel at high rates of speed for relatively short distances. Energy released from a single cavitation bubble is extremely small, but the cavitation of millions of bubbles every second has a cumulative effect throughout a fluid as the pressure, temperature and velocity of the jets of plasma destroy many contaminants in the fluid. The resonant frequency of an energized transducer typically determines the size and magnitude of the cavitation bubbles, with the number of cavities formed typically increasing as the frequency increases. Lower frequencies tend to create larger bubbles with more energy as the available power is concentrated in fewer bands of pulsed fluid treatment, while higher frequencies tend to produce smaller bubbles that distribute power more evenly throughout the fluid treatment chamber. Slight shifts in the resonant frequency of a transducer are preferred to enhance fluid treatment and the repetition rate of a pulsed electrical signal may be programmed to automatically vary on a constant basis. For example, a transducer designed to operate at 20 kHz may be driven by an electrical energizing unit sweeping 19 kHz-21 kHz to transform electrical energy into a signal suitable for generating fluid cavitation. However, an electrical energizing unit may be programmed to produce pulsed electrical signals sweeping an even broader range of frequencies.
The physical properties of high density, low viscosity, middle range surface tension and middle range vapor pressure are ideal conditions for cavitation, with surface tension being a significant factor in determining the intensity of bubble cavitation.
In certain applications, diffused ambient air or other forms of small bubbles may be introduced immediately upstream of the fluid treatment chamber to assist in initiating the cavitation process. Electrolysis of a feedstock may also be utilized to generate small bubbles in a feed stream by energizing at least one pair of electrodes with electrical energy. Each electrode may comprise at least one plate comprising an electrical conducting material and having at least one conductor lead, with each pair of electrodes configured as a substantially parallel array of spaced-apart plates interleaving to form at least one cavity between the facing surfaces of adjacent plates. Each electrode plate may be energized with an electrical charge opposite from its adjacent plate. The conductivity of a feedstock typically influences the voltage required to maintain the level of current required to energize the electrodes. Electron flow between the charged plates, along with electromagnetic field generation, releases oxygen and hydrogen bubbles from many water-based feedstocks that may be useful in initiating the cavitation process. Electrodes may be energized with electrical energy having an alternating current component or a direct current component. It may be desirable to periodically reverse the polarity of the signal applied to such electrodes to reduce the plating of contaminants on the surfaces of the electrodes. In certain applications, a pulsed fluid treatment device or a magnetic field treatment device may be configured upstream of the electrodes to retard plating of the electrodes.
Most biological contaminants regulate their water intake through osmosis via the electrical charge of fats and proteins in their surface membranes. Directing biological contaminants to pass through at least one pulsed electromagnetic wave may overwhelm the electrical fields and charges in the surface membranes of these microorganisms and drive them to an imbalanced state, weakening their cell walls and destroying the membranes. Unlike chemical treatment and other means of controlling many biological contaminants, many organisms may not develop immunity to the instant method of fluid treatment. Further, the utilization of charged electrodes may provide an additional means of destroying biological contaminants in fluids.
Directing an emulsion of oil and water through at least one pulsed electromagnetic wave may cause the water to repel the oil and the oil to repel the water. Pulsed electromagnetic waves may neutralize the charges of many suspended and dissolved solid contaminants that tend to cause emulsions, allowing small oil droplets to coalesce into larger oil droplets, float out of the water and be removed by separation apparatus. Similarly, water may be removed from hydrocarbon fluids. At least one pair of charged electrodes may be utilized in concert with the instant invention to break many of the bonds that create many types of emulsions.
At least one chemical dispersing apparatus providing means for distributing a supply of at least one fluid treatment chemical into a fluid directed to pass through at least one pulsed electromagnetic wave may be utilized to disperse a supply of at least one chemical into a feed stream upstream of the fluid treatment vessel, into the fluid treatment vessel or downstream of the fluid treatment vessel. Fluid treatment chemicals may be selected from a group consisting of but not limited to, algaecides, biocides, scale retardants, coagulants, flocculants, pesticides, fertilizers, coolants, ambient air, oxygen, hydrogen, ozone, hydrogen peroxide, surfactants, petroleum production fluid additives, fuel additives and lubricant additives. As used herein, charged electrodes generating oxygen and hydrogen bubbles in the electrolysis of water-based feedstocks may comprise a chemical dispersing apparatus.
In some instances, chemical pretreatment may hamper the efficiency of separation apparatus, such as screening devices that tend to blind off with chemically treated feedstocks, and hydrocyclones, desanders and desilters. Improved removal of suspended and dissolved solid contaminants from a fluid may be achieved by directing a feed stream free of coagulants or flocculants to pass through at least one pulsed electromagnetic wave upstream of such apparatus to enhance the separation of solids from a fluid.
At least one contaminant separation apparatus providing means for separating and collecting a volume of contaminants from a fluid and discharging a processed feed stream having a reduced volume of contaminants carried within a treated fluid column may be utilized to treat a feed stream upstream of the fluid treatment vessel or downstream of the fluid treatment vessel. Contaminant separation apparatus may be selected from a group consisting of, but not limited to, phase separation systems, solids separation equipment, dewatering devices, oil/water separators, petroleum production equipment, petroleum refining systems, water filters, desalination equipment, reverse osmosis systems, fuel filters and lubricant filters.
At least one fluid flow conditioning apparatus providing means for altering the flow of a fluid directed to pass through at least one pulsed electromagnetic wave may be utilized to alter the flow of a feed stream upstream of the fluid treatment vessel, within the fluid treatment vessel or downstream of the fluid treatment vessel. Fluid conditioning apparatus may be selected from a group consisting of, but not limited to, pumps, blowers, vortex inducing equipment, static mixing devices and dynamic mixing apparatus to create turbulence in a flow of fluid or laminar flow conditioners to remove turbulence from a flow of fluid.
The foregoing description of the preferred embodiment has been for the purpose of explanation and illustration. It will be appreciated by those skilled in the art that modifications and changes may be made without departing from the essence and scope of the present invention. Therefore, it is contemplated that the appended claims will cover any modifications or embodiments that fall within the scope of the invention. | Methods and apparatuses are disclosed including a method of neutralizing charges of solid contaminants and weakening cell walls and membranes of biological contaminants in a fluid, comprising the steps of: establishing a flow of a fluid through a fluid treatment chamber surrounded by a sidewall of a fluid treatment vessel shaped as a conduit having a fluid input port, and a fluid output port, the sidewall constructed of a shielding material; and energizing a coil of at least one antenna within the fluid treatment chamber with at least one electrical energizing unit to produce pulsed radiation within the fluid treatment chamber to treat the flow of the fluid therein, wherein the sidewall of the fluid treatment vessel establishes a chamber having a capacity to restrict propagation of the pulsed radiation out of the fluid treatment vessel. | 2 |
FIELD OF THE INVENTION
The invention relates to a process to prepare a multidentate phosphite compound represented by the general formula (1) ##STR4## in which n is 2-6, R is an n-valent organic group and R 1 and R 2 are fused aromatic ring systems having 2 or more rings. The rings of R 1 and R 2 are substituted in the ortho position (relative to the oxygen atom), only with hydrogen, provided that substitution is possible. The phosphite compounds are prepared by first preparing a phosphorochloridite compound starting from R 1 --OH and R 2 --OH alcohol compounds and a phosphorous chloride compound. In a subsequent step, the phosphorochloridite compound is contacted with an alcoholic compound R--(OH) n to yield the phosphite.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 5,235,113 discloses the preparation of a phosphorochloridite by reacting 3,6-di-tert-butyl-2-naphthol dissolved in triethylamine and PCl 3 dissolved in toluene. A bidentate phosphite is subsequently prepared by contacting the phosphorochloridite compound with 2,2'-biphenyldiol in triethylamine.
Disadvantages of this known process include the difficulty in preparing the intermediate phosphorochloridite compound in a high yield when starting from alcohols (R 1 OH and R 2 OH) in which the steric bulk around the hydroxyl group is not sufficiently large. In this case, the main product will be a triorganophosphite compound in which the organo-groups correspond to the starting alcohol compound. The formation of this compound can be explained by the relatively minimal steric hinderance around the P--O bond of the phosphite, which makes it possible for three moles of alcohol to react with one mole of PCl 3 .
There is a need for a process in which these phosphorochloridite compounds can be prepared in a high yield. The phosphorochloridite compounds are needed to prepare the class of multidentate phosphite compounds represented by formula (1) which presently are difficult to obtain.
SUMMARY AND OBJECTS OF THE INVENTION
This need is satisfied by the present process in which the phosphorochloridite compound is prepared by performing the following two steps in a solvent:
a) contacting a compound represented by the general formula: ##STR5## in which R 3 and R 4 are C 1 -C 4 alkyl groups, with the R 1 OH and R 2 OH compounds, and
b) contacting the resulting compound of step (a) which is represented by the formula (3): ##STR6## with HY, wherein Y represents a halogen atom.
The present invention makes it possible to prepare the phosphorochloridite compound and thus the phosphite compound represented by formula (1) in a high yield.
A method for preparing phosphite compounds directly, in one step, from a dialkyl-N,N'-dialkylphosphoramide compound and a mono-alcohol is described in Synthesis, 1988, 2, 142. The resulting phosphite compound is, however, a monodentate phosphite compound. It appeared difficult to prepare a multidentate phosphite compound directly in an analogous method by starting from a compound, R(OH) n , with more than one alcohol functionality (n>1).
DETAILED DESCRIPTION OF THE INVENTION
Starting alcoholic compounds R 1 OH and R 2 OH preferably have 10-30 carbon atoms and preferably comprise 2 to 4 fused aromatic rings. Examples are naphthol, anthranol and phenanthrol. All carbon atoms adjacent or ortho to the hydroxyl group substituted carbon atom are substituted, if possible, only with hydrogen. Other carbon atoms of the fused rings may optionally be substituted with other groups, for example alkoxy, alkyl, amine and halogen groups. Preferably, R 1 and R 2 are the same group. R 1 and R 2 are preferably 9-phenanthryl or 1-naphthyl groups.
Step (a) can be performed in substantially the same manner as described in Synthesis, 1988, 2, 142-144, the complete disclosure of which is incorporated herein by reference. This article describes the preparation of alkyl and aryl di-tert-butyl phosphates using di-tert-butyl N,N-diethylphosphoramidite as an intermediate compound. This intermediate compound is analogous to the compound represented by formula (3).
The compound according to formula (2) can be obtained by methods known to those skilled in the art. For example, methods can be used substantially analogous to those described in Synthesis, 1988, 2, 142-144.
R 3 and R 4 are, independent of one another, C 1 -C 4 alkyl, such as for example methyl, ethyl, propyl, butyl or tert-butyl. Preferably, R 3 and R 4 the same group.
In Step (a), the compound according to formula (2) is contacted in a suitable solvent with the R 1 OH and R 2 OH, preferably in the presence of a base. Examples of bases include organic bases such as, for example, a trialkylamine having 2 to 12 carbon atoms. Examples of suitable solvents include ethers like, for example, diethyl ether, dioxane or tetrahydrofuran and aromatic solvents like, for example, benzene or toluene. Step (a) is preferably performed at a temperature between about -80° and about 60° C., and more preferably, at about room temperature.
The concentration of the compound represented by formula (2) is preferably between about 0.01 and about 5 mol/l. The molar ratio of R 1 OH and R 2 OH and the compound (2) is preferably stoichiometric. Other ratios may be possible, but generally, a greater effort is then needed to purify the product.
In Step (b), the Y of HY can be F, Cl, Br or I. A preferred HY is HCl. HY can be present in a gaseous form or dissolved in solvent such as, for example an ether like diethyl ether, dioxane or tetrahydrofuran or in an aromatic solvent like benzene or toluene. The temperature in step (b) is preferably between -80° and 60° C. The molar ratio of HY and compound (3) is preferably between about 0.8 and about 5.
The step (b) phosphorochloridite reaction product, e.g. a compound according to the general formula (3), is generally dissolved in a reaction mixture having precipitated R 3 R 4 NH.HCl salt present. It can be advantageous to separate the salt from the phosphorochloridite compound before using this compound further. Separation is especially preferred when the R--(OH) n compound is not very reactive. Separation can be performed by, for example, filtration of the reaction mixture.
The phosphorochloridite compound thus obtained is subsequently contacted with an alcoholic compound according to R--(OH) n in which R is the n-valent organic group of formula (1) and n is 2 to 6.
The conditions for such a contacting in order to prepare the phosphite compound are generally known and are, for example, described in the aforementioned U.S. Pat. No. 5,235,113, the complete disclosure of which is hereby incorporated by reference. In general, the contacting is performed in a suitable solvent like, for example, the solvents for step (a). Preferably, contacting is performed in the presence of a base like, for example, an organic base like, for example, an alkylamine exemplified by triethylamine. The temperature is preferably between about -80° about 100° C.
The n-valent group R can be any of the organic bridging groups which are commonly known for multidentate phosphite compounds such as, for example those groups described in U.S. Pat. No. 5,235,113, EP-A-214622 and WO-A-9518089, the complete disclosures of which are incorporated herein by reference.
Preferably the n-valent group has at least two carbon atoms and less than 40 carbon atoms. The n-valent group can be, for example, alkylene groups or divalent aromatic groups. Examples of suitable alkylene groups include ethylene, trimethylene, tetramethylene or pentamethylene. Examples of alcohols according to R--(OH) n , which are the building blocks of the n-valent organic group, include 2,5-di-t-butylhydroquinone, 2,5-di-t-amylhydroquinone, 2,5-dimethylhydroquinone, 4,6-di-t-butylresorcinol, 4,4'-isopropylidenebisphenol, 4,4'-methylenebis(2-methyl-6-t-butylphenol), 4,4'-oxobis(2-methyl-6-isopropylphenol), 4,6'-butylidenebis (3-methyl-6-t-butylphenol), 2,2'-biphenyldiol, 3,3',5,5'-tetramethyl-2,2'biphenyldiol, 3,3',5,5'-tetra-t-butyl-2,2'-biphenyldiol, 3,3'-dimethoxy-5,5'-dimethyl-2,2'-biphenyldiol, 3,3'-di-t-butyl-5,5'-dimethoxy-2,2'-biphenyldiol, 3,3'-di-t-butyl-5,5'-dimethyl-2,2'-biphenyldiol, 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 2,2'-thiobis(4-methyl-6-t-butylphenol), 2,2'-thiobis(4-t-butyl-6-methylphenol), 2,2'-thiobis(4,6-di-t-butylphenol), 1,1'-thiobis(2-naphthol), catechol, 2,3-dihydroxynapthalene, 1,8-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,3,5-trihydroxybenzene, 1,1'-methylenebis(2-naphthol), 1,1'-di-2-naphthol, 10,10'-di-9-phenanthrol, ethyleneglycol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, pentaerythritol, trans-1,2-cyclohexanediol, cis-1,2-cyclohexanediol, cis-1,2-cyclohexanedimethanol, cis-1,2-cyclododecanediol, and the like.
A preferred and novel class of bidentate phosphite compounds represented by formula (1) have a group R according to the following formula (4): ##STR7## in which X is hydrogen or an organic group. Preferably, both X substituents are an organic group, and more preferably, an alkyl group, an aryl group, a triarylsilyl group, a trialkylsilyl group, a carboalkoxy group, a carboaryloxy group, an aryloxy group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an amide or a nitrile group. The present invention is also directed to this novel bidentate phosphite ligand.
The alkyl group is preferably a C 1 -C 10 alkyl group such as, for example methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, isobutyl, pentyl or hexyl. Exemplary of a triarylsilyl group is triphenylsilyl and examples of a trialkylsilyl group are trimethylsilyl and triethylsilyl. Preferred aryl groups have 6 to 20 carbon atoms, such as, for example, benzyl, tolyl, naphthyl or phenanthryl. Preferred aryloxy groups have 6 to 12 carbon atoms and include, for example phenoxy. Preferred alkoxy groups have 1 to 10 carbon atoms and include, for example, methoxy, ethoxy, tert-butoxy or isopropoxy. Preferred alkylcarbonyl groups have 2 to 12 carbon atoms and include, for example, methylcarbonyl and tert-butylcarbonyl. Preferred arylcarbonyl groups have 7 to 13 carbon atoms such as, for example, phenylcarbonyl.
X is most preferably a carboalkoxyl or carboaryloxy group, --CO--O--R 3 , in which R 3 is an alkyl group having 1 to 20 carbon atoms or an aryl group having 6-12 carbon atoms. Examples of suitable R groups include methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, isobutyl, phenyl, tolyl. Even more preferably, both X substituents are the same carboalkoxyl group.
The phosphite compounds having a bridging group R represented by formula (4) as described above can be advantageously used as part of a homogeneous catalyst system also comprising rhodium. Such a catalyst system is preferably used for the hydroformylation reaction of an unsaturated organic compound, and especially, of an internally unsaturated organic compound to a terminal aldehyde organic compound. High reaction rates and high selectivities to linear or terminal aldehyde products can be achieved when using such catalyst system.
It has been found, for example, that when using such a catalyst system, the reaction of a C 1 -C 6 alkyl 3-pentenoate ester to the C 1 -C 6 alkyl 5-formylvalerate ester proceeds with a high selectivity, yield and reaction rate when compared to state of the art processes, such as, for example, processes described in WO-A-9518089, the complete disclosure of which is hereby incorporated by reference. The present invention is also directed to a process for preparing C 1 -C 6 alkyl 5-formylvalerate esters. Preferably, the alkyl is methyl or ethyl.
Preferably, the multidentate phosphite compound represented by formula (1) as obtained by the process of the invention is used as a polymer stabilizer. Preferably, the multidentate phosphite compound represented by formula (1) as obtained by the process of the invention is used as a fire retarding additive or filler.
Preferably, the multidentate phosphite compound as obtained by the process of the invention is used as part of a homogeneous catalyst system also comprising a metal of Group VIII. The homogeneous catalyst system can be used for the isomerization of olefins. More preferably, the homogeneous catalyst system is used in the hydroformylation of an ethylenically unsaturated organic compound to a terminal aldehyde compound. Preferably the unsaturated compound is a pentenoic acid, or its corresponding ester or nitrile, and the Group VIII metal is rhodium. The resulting 5-formylvaleric acid, or its corresponding ester or nitrile, are important intermediates in a process to prepare precursors for Nylon-6 and Nylon-6,6.
The invention will be elucidated with the following non-limiting examples.
EXAMPLE I
3.88 g (20 mmol) 9-phenanthrol was dissolved in 250 ml toluene and water was removed by azeotropic distillation. Subsequently, 2.3 g triethylamine and 1.74 g (10 mmol) diethylaminophosphorous dichloride were added at room temperature while stirring. In this way, diethylamino diphenanthrene phosphite was synthesized ( 31 P NMR δ 138.7 ppm). To obtain diphenanthrene phosphorous chloride, 22 ml of a 1 M HCl solution in diethyl ether was added ( 31 P NMR δ 161.4 ppm). The reaction mixture was filtered, and to the filtrate, 3 g (30 mmol) of triethyl amine and 1.98 g of dimethyl 2,2'-dihydroxy-1,1'-binaphthalene-3,3'-dicarboxylate were added. After stirring for 10 minutes, the reaction was completed and NEt 3 .HCl was removed by filtration (Et=ethyl). The solvent was removed and the product was purified by crystallization from acetonitrile/toluene ( 31 P NMR δ 126.6 ppm). The yield of product Compound 1, represented below, was 90%. ##STR8##
Comparative Example A
Compound 1 was also intended to be prepared starting from 9-phenanthrol by the synthetic route described in Example 10 of U.S. Pat. No. 5,235,113. It was, however, not possible to obtain the phosphorochloridite intermediate in a high yield (about 5%). Rather, tri(9-phenanthryl)phosphite was mainly obtained. The desired product in yield of only 5% could not be isolated easily. This experiment illustrates that it is difficult to prepare the Compound 1 by the prior art synthetic route as for example described in EP-A- 518241.
EXAMPLE II
A 150 ml Hastelloy-C steel autoclave (Parr) was filled under nitrogen with 5.8 mg Rh(acac)(CO) 2 (acac=acetylacetonate) (4.8×10 -5 mol), 14.0×10 -5 mol of Compound 1 as ligand (ligand/rhodium ratio (L/Rh)=2.9 mol/mol) and 60 ml of toluene. Hereafter, the autoclave was closed and purched with nitrogen. Next, the autoclave was brought to a pressure of 1 MPa using carbon monoxide/hydrogen (1:1) and heated to 90° C. in approx. 30 min. Subsequently, a mixture of 7.44 g (65 mmol) freshly distilled methyl 3-pentenoate and 1.2 gram of nonane topped up to 15 ml with toluene was injected into the autoclave. The composition of the reaction mixture was determined by gas chromatography. After 7 hours of reaction, a 90.1% conversion was determined. The selectivity to methyl 5-formylvalerate was 75.1%. The molar ratio of methyl 5-formylvalerate and the sum of methyl 3- and methyl 4-formylvalerate (n/b ratio) was 9.3, and the hydrogenation to methyl valerate was 5.7%.
EXAMPLE III
Example II was repeated in which the L/Rh ratio was 3.1 with a ligand represented by: ##STR9## The conversion was 81.8% and the selectivity to methyl 5-formylvalerate was 84.6%.
EXAMPLE IV
Example I was repeated using as R--(OH). compound di-isopropyl 2,2'dihydroxy-1,1'-binaphthalene-3,3'-dicarboxylate and as R 1 (OH) starting compound 9-phenanthrol. A compound represented by: ##STR10## was obtained as a slightly yellow coloured powder in 85% yield.
EXAMPLE V
Example I was repeated using as R--(OH) n compound pentaerythritol and as R 1 (OH) starting compound 1-naphthol. A compound represented by: ##STR11## was obtained as a yellow coloured oil in a 80% yield.
EXAMPLE VI
Example I was repeated using as R--(OH) n compound diethyl 2,2'-dihydroxy-1,1'-binaphthalene-3,3'-dicarboxylate and as R 1 (OH) starting compound 4-chloro-1-naphthol . The yield was about 90%.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to those of ordinary skill in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. | A process to prepare a multidentate phosphite compound according to the general formula (1) ##STR1## in which n is 2-6, R is an n-valent organic group and R 1 and R 2 are fused aromatic ring systems with 2 or more rings, which rings are substituted on the ortho position relative to the oxygen atom only with hydrogen, by first preparing a phosphorochloridite compound from a R 1 --OH and R 2 --OH alcohol compound and a phosphorus chloride compound and subsequently contacting the phosphorochloridite compound with an alcoholic compound according to R--(OH) n , wherein the phosphorochloridite is prepared by performing the two steps in a solvent:
a) contacting a compound with the general formula: ##STR2## in which R 3 and R 4 are C 1 -C 4 alkyl groups, with the R 1 OH and R 2 OH compounds, and
b) contacting the resulting compound of step (a) which has the formula (3): ##STR3## with HY, wherein Y is a halogen. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to polyurethane resins which are useful in producing polyurethane resin coatings which, in particular, exhibit excellent weather resistance.
2. Description of the Prior Art
Polyurethane resins are classified into two types by the kind of isocyanate compounds contained in them. The classification thus includes "yellowing" and "non-yellowing" types. Isocyanates which have hitherto been in use as ones giving polyurethane resins of the non-yellowing type include: such aliphatic isocyanates as hexamethylenediisocyanate, isophoronediisocyanate, 2,2,4-trimethylhexamethylenediisocyanate, dicyclohexylmethanediisocyanate, etc.; and xylylenediisocyante, etc. Whilst non-yellowing type polyurethane resins obtained by causing these isocyanates to react with polyols have been employed as coating materials, there still remained many problems to be solved in using them for such purpose.
One of these problems is their toxicity. Since isocyanate compounds are substances which are chemically highly reactive, they are very dangerous when used by persons who are of an allergic constitution or have weak respiratory organs. Because of this, the limit of concentration in the atmosphere of, for instance, monomers of toluenediisocyanate, diphenylmethanediisocyanate, etc., was fixed at 0.02 ppm by the Commission of the American Conference of Governmental Industrial Hygienists. For such reason, the unmodified isocyanate monomers are seldom used in polyurethane coatings. However, in special cases, they are used after having been modified into prepolymers--adducts obtained by adding them to trimethylolpropane, ethylene glycol, etc. This modification has the effect of lowering vapor pressure, thereby reducing the toxicity and bad odor of the isocyanate. In addition, modification allows adjustment of the reactivity of the isocyanate and diversification in the type of coatings to be realized.
Since, however, it is difficult to wholly eliminate isocyanate monomers in the prepolymer additions during commercial operation, the fact is, that one still smells a strong irritating odor while he is engaged in the work of preparing coating materials or of applying coats. Many people complain of the symptoms of respiratory diseases which are peculiarly contracted by inhaling isocyanate vapors. With an increase in the use of polyurethane products, this question has now more than ever been brought much to the fore.
With the isocyanate additions and while these materials are in storage, in particular, it is said that there occurs dissociation of diisocyanates into highly toxic monomers, depending upon the storage conditions, and this constitutes an uneasy factor for those concerned including chemical engineers and operators alike. Under such circumstances, certain measures are being taken for improvement of the working environment. For instance, provision of good ventilation, is necessary so that the operators will not directly inhale the isocyanate compound vapors. However, the state of things in this connection is still far from being satisfactory.
The second question in the conventional technology is that there remains, with the conventional coatings, much to be desired with respect to their weather resistance. Although the non-yellowing type polyurethane resins were originally developed with a view to improving the weather resistance of coatings, they are not, as yet, sufficiently resistant to weather when used as coatings for items which are exposed to severe outdoor conditions over a long period of time, such as automobiles, railroad carriages, aircrafts, vessels, building materials, and so forth.
The third question concerning polyurethane coating materials, according to conventional techniques, is that the range in which the selection of solvent composition can be made is not necessarily wide enough, and that, if the amount of solvent is reduced from the viewpoint of energy saving and prevention of environmental pollution, the coating efficiency of the resultant product, being the so-called "high solid type" coating with a high concentration of polyurethane resin, is impaired because of its high viscosity.
SUMMARY OF THE INVENTION
The main object of the present invention is to provide polyurethane resins and polyurethane resin coatings having a high resistance to weather.
Another object of this invention is to provide polyurethane resin coating compounds which afford an improved coating work efficiency.
Still other objects of the present invention will become clear from the description to follow.
We have found that a novel aliphatic triisocyanate, 1,6,11-undecane triisocyanate, can be utilized for preparing a polyurethane resin film coat having an excellent weather resistance, and that the objects of the present invention can be therefore attained.
The film coat of the present invention has, for its main ingredient, a polyurethane resin which is a reaction product obtained by causing a polyol to react with 1,6,11-undecane triisocyanate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
1,6,11-Undecane triisocyanate, used for preparing the polyurethane resin of the present invention, belongs to a new type of aliphatic triisocyantes and possesses advantages over aliphatic polyisocyanates of the prior arts.
1,6,11-Undecane triisocyanate can be prepared from 1,6,11-undecane triamine by a conventional phosgenation method. The novel triisocyanate boils at 166° C. to 167° C. under a vacuum of 0.2 torr. This boiling point range will be appreciated to be well-balanced from the view-point of purification and toxicity. This isocyanate generates scarcely any odor or vapor irritating the nose, eyes, throat, etc., because of its low vapor pressure, whereas it can be easily purified by vacuum distillation.
This triisocyanate differs significantly from the other aliphatic isocyanates, such as hexemethylene diisocyanate or 2'-isocyanatoethyl-6-isocyanatocaproate by its substantially reduced toxicity and strong resistance to the action of alkaline substances. Some of these properties may be attributed to the chemical structure of the novel triisocyanate as it has neither any hetero-atoms such as oxygen and nitrogen, nor any unsaturated bonds in the molecule except for three NCO groups.
Moreover, the NCO group content in the novel triisocyanate reaches as high as about 45 weight percent, based on the total weight of the triisocyanate. Furthermore, the novel triisocyanate has low viscosity so that it does not necessarily require dilution with solvents for the purpose of lowering viscosity for practical usage.
Thus the novel triisocyanate is extremely suitable for preparing a non-yellowing type polyurethane resin.
A polyol as referred to in the present invention means a compound or polymer containing two or more hydroxyl groups per molecule.
As examples of polyols, there are diols, triols, tetraols, pentols and hexitols; while there are also such polymer polyols as polyester containing two or more hydroxy radicals per molecule (hereinafter called "polyester polyol"), polyether containing two or more hydroxyl groups per molecule (hereinafter called "polyether polyol"), acrylic polymer containing two or more hydroxyl radicals per molecule (hereinafter called "polyacryl polyol"), etc. In the present invention, there may be used either singly or as a mixture of two or more kinds. Hereunder are given further examples, in more particulars, of polyols.
Diols: ethylene glycol, propylene glycol, β,β'-dihydroxydiethyl ether (diethylene glycol), dipropylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, polyethylene glycol, polypropylene glycol, polypropylene-polyethylene glycol, polybutylene glycol;
Triols: glycerine, trimethylol propane, 1,2,6-hexanetriol;
Tetraols: penta erythritol, 2-methylglucoside;
Hexitol: sorbitol;
Polyester polyols; These are polymerized by the condensation reaction between a polybasic acid, such as adipic acid, dimer acid, phthalic anhydride, isophthalic acid, etc., and a diol or triol, such as ethylene glycol, diethylene glycol, propylene glycol, trimethylol propane, glycerine, etc.
Polyether polyols: These are prepared by adding propylene oxide, ethylene oxide, or the like, to a polyhydric alcohol, such as glycerine, propylene glycol, etc. In this category are also included polyether polyols rich in hydroxyl radicals obtained by causing a multifunctional compound such as ethylenediamine, ethanolamine, etc. to react with ethylene oxide or propylene oxide.
Polyacryl polyols: Copolymers of an acrylic acid ester or methacrylic acid ester containing a hydroxyl group (as expressed by the following general formula) in combination with a monomer which is capable of being copolymerized with such: ##STR1## wherein n=1, 2 or 3
R 1 =hydrogen or methyl
R 2 =a remnant radical of substituent or nonsubstituent hydrocarbon with a carbon number of 2 to 12
Hereunder are enumerated examples of acrylic acid esters or methacrylic acid esters containing the aforesaid hydroxyl group. 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 2-hydroxypentyl methacrylate, methacrylic acid monoester of glycerine, acrylic acid or methacrylic acid monoester of trimethylol propane, 2-hydroxy-3-chloropropyl acrylate, 2-hydroxy-3-chloropropyl methacrylate, etc.
Out of these, the most desirable are: 2-hydroxylethyl methacrylate, 2-hydroxyethyl acrylate and 2-hydroxypropyl methacrylate.
Examples of monomers which are capable of being copolymerized with the above-mentioned acrylic acid or methacrylic esters containing a hydroxyl group are given below:
(1) acrylic acid or its esters, for example, acrylates of methyl, ethyl, propyl, butyl or 2-ethylhexyl
(2) methyacrylic acid or its esters, for example, methacrylates of methyl, ethyl, butyl, decyl, 2-ethylhexyl or lauryl
(3) styrene or its derivatives, for example, α-methylstyrene, β-chlorostyrene, etc.
(4) vinyl esters, for example, vinyl acetate, vinyl propionate, vinyl isopropionate, etc.
(5) nitriles, for example, acrylonitrile, methacrylonitrile, etc.
Out of these, the most desirable are: methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, butyl methacrylate, lauryl methacrylate, acrylic acid, methacrylic acid, styrene, acrylamide, vinyl acetate, etc.
To prepare polyacryl polyols best suited for purpose of this invention, it is desirable that the amount of each monomer used be selected from the following ranges:
(A) Hydroxylalkyl(meth)acrylate . . . 5 to 30 pct. by wt.
(B) Alkyl ester of acrylic acid and/or of methacrylic acid . . . 50 to 95 pct. by wt.
(C) Other monomer(s), as occasion demands . . . 0 to 50 pct. by wt.
(D) Acrylic acid or methacrylic acid . . . 0 to 10 pct. by wt.
If, of the foregoing, the amount of hydroxylalkyl(meth)acrylate is less than 5 pct. by wt., the degree of bridging by reaction with isocyanate compounds becomes too small and hence it will be impossible to obtain a film coat of such performance as was to be expected.
While the manufacture of polyacryl polyols by copolymerization of monomers, as described above, may be carried out by any one of such well known polymerization methods as solution, block, emulsion and suspension polymerization, the first mentioned method, i.e., solution polymerization, is generally employed.
Selection of the polyols may be made at one's discretion so as to fit a specific purpose, but, in general, the use of polyester polyols or polyacryl polyols is preferable.
As for the molecular weight of the polyols used, too, selection may be made from quite a wide range according to the specific purpose. For the "high solid type" coating, however, a range of 500 to 5,000, especially, 500 to 3,000, is preferred. More particularly, when polyester polyols are used, those with a molecular weight in the range of 500 to 1,000 are best suited for the purpose; while when polyacryl polyols are used, those with a molecular weight in the range of 1,000 to 3,000 may be utilized to best advantage. When manufacturing coatings which are not of the "high solid type", polyols with a molecular weight higher than ordinary are employed.
By making the proper choice of polyols to be used and by adjusting the NCO/OH mole percentage, the physical properties and hence efficiency of the product, such as the strength of film coat, flexibility, chemical resistance, solvent resistance, etc., can be modified in a wide range, thereby to make it suitable for specific purposes.
Compounds of which the NCO/OH mole percentage is in the range of 0.5 to 2.0 are suited for the manufacture of films and for the application of film coat. For polyurethane coatings, in particular, the range of 0.5 to 1.2 is preferred.
If the NCO/OH mole percentage is below the lowest figure, as above noted, the hot water and acid resistance of the resulting film coat is lowered, resulting in a poorer weather resistance. When it is above the highest figure, there also takes place a lowering of weather resistance.
Those compounds with an NCO/OH mole percentage in the range of 0.5 to 1.0 may be advantageously used for such fields as electrical insulation, capsulation, and manufacture of cast products.
When the NCO/OH mole percentage is in the range of 0.1 to 0.7, such compounds may be advantageously utilized for the manufacture of highly efficient adhesives or hardening agents. When, on the other hand, the NCO/OH mole percentage is greater, such compounds are suited for the manufacture of foam products. The foaming may be achieved by introducing a certain fixed amount of water or a blowing agent into the reaction products, by utilization of known foaming techniques.
The polyurethane resin coating of the present invention is adaptable to both the one-component and two-component types, but is more advantageous to use it as a two-component type coating.
(1) TWO-COMPONENT, POLYOL HARDENING TYPE
This is a two-component type polyurethane resin coating comprising a kneaded mixture of a polyol and a pigment, the latter being added at need ("A" liquid), and a trifunctional isocyanate of the present invention, diluted with a solvent as needed ("B" liquid). In use, the "A" and "B" liquids are mixed together and, when necessary, the viscosity is adjusted by the use of a thinner. For mixing the two liquids, a two-liquid gun may preferably be employed. It is desirable that the mixing ratio be determined in such a manner that the NCO/OH mole percent will be 0.5 to 2.0, the concentration of carbamide radical 5×10 -4 to 50×10 -4 moles per gram of the reaction product, and the bridging parameter 150 to 1,500.
The solvent in the "B" liquid, and the thinner for the mixture, which is used if needed, may be either the same or different; but, in the latter case, it is necessary that the two are compatible with each other. Further, these must not be ones which are reactive with isocyanates and polyols, such as ones containing active hydrogen atoms. Some examples of solvents that may be used are given below.
Hydrocarbon solvents: benzene, toluene, xylene, and aromatic naphtha.
Ester solvents: ethyl acetate, butyl acetate, cellosolve, hexyl acetate, amyl acetate, ethyl propionate, and butyl propionate
Ketone solvents: acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, diethyl ketone, and cyclohexanone.
Glycol ester solvents: ethylene glycol monoethyl ether acetate, and diethylene glycol monoethyl ether acetate.
One of the characteristics of the present invention resides in the fact that, of the whole solvent composition, more than 50 pct. by wt. can be the aforesaid hydrocarbon solvent.
Further, the amount of solvent in the aforesaid "B" liquid can be as small as 0 to 50 pct. by wt., and this also constitutes a characteristic of the coating in accordance with the present invention. This makes it easier to obtain a "high solid type" coating--a contributing factor in improving the outward appearance of film coats.
As for polyols to be used, those which were previously mentioned, that is, polyester polyols, polyether polyols, polyacryl polyols, etc., are recommended. These are certain to give good results.
By combining the proper kinds of polyols and isocyanate compounds, it is possible to obtain coats of varied properties, from soft to hard and tough, all of which possess excellent resistance to weather, water, chemicals and staining. Coatings of this type are ordinarily used at temperatures ranging from room temperature to 120° C. They display an excellent adhesive property when used for the coating of such materials as ferrous and nonferrous metals, plastics, rubber, leather concrete, etc., and hence have a wide range of applications in such fields of industry as the manufacture of building materials, automobiles, machines and instruments, woodworks, aircraft, railroad carriages and ships; and so forth.
(2) ONE-COMPONENT, HEAT CURING TYPE
With coatings of the two-component, polyol hardening type which has been described above, the reaction progresses even at room temperature; hence there frequently arise cases where the pot life of coatings in use presents a problem.
In this type of coating, (one-liquid, heat curing type), the isocyanate group of the isocyanate compound is once blocked by the addition of a blocking agent so that the coating will be stable at room temperature. The coating, after having been applied, is heated to dissociate the blocking agent. The isocyanate group is thus activated again and is caused to react with the hydroxyl group to form a film coat. This method is best suited for such applications as the coating of automobiles on a manufacturing line, or the like, where it is necessary to ensure stability of the coating materials while they are in storage at room temperature.
As polyols to be combined with the blocked type isocyanate prepolymer, polyester polyols and polyacryl polyols may be used to best advantage.
As blocking agents for the purpose of masking the free isocyanate radical of the trifunctional isocyanate compounds used in the present invention, those which are in general use may be brought into employment. Hereunder are given some examples of such blocking agents: Phenol, m-nitrophenol, p-chlorophenol, catechol, ethyl malonate, acetylacetone, ethyl acetoacetate, cresol, ε-caprolactam, methyl ethyl ketoxime, cyclohexanoneoxime, butyl mercaptan, methanol, ethanol, ethylene chlorohydrin, etc.
Although the temperature at which the above-mentioned blocking agents are dissociated varies with the type of blocking agent used, it is generally accepted that heating to at least 120° C. is required. Since this type coating requires baking at a relatively high temperature, it has hitherto been in use mainly in such fields as the manufacture of electric wires, etc. It is expected, however, that there will be new developments in its utilization, such as adaptation to a powder paint with polyurethane resin base, to an aqueous emulsion paint, and so forth.
Solvents for this type of coating, which are used as occasion demands, are identical with those in the case of the two-component type coatings. In this instance, too, more than 50 pct. by wt. of the whole solvent composition can be hydrocarbon solvents.
The coating compounds according to the present invention can be applied to the desired articles by ordinary coating methods such as spray, brush or roller coating, or dipping. The compounds also permit the use of commonly used pigments and plasticizers, or other kinds of additives which are used in small amounts when preparing the paint or when applying it, provided that the amounts used are within the limit of the common practice. For the choice of pigments, it is necessary to pay attention to their water content, as well as to other properties similar to those noted above in conjunction with the selection of suitable solvent. It is to be noted that extenders, in particular, have a great water adsorbability.
Catalysts may also be used to accelerate drying and hardening. For instance, such tertiary amines as dimethylethanolamine, triethylenediamine, etc., and organic salts of tin such as stannous, dibutyl tin dilaurate, etc., may be employed.
The characteristics of the coating according to this invention are as follows:
(1) It excels in gloss retention and anti-cracking properties.
(2) It has an excellent resistance to acid and water. It is thought that, this comes from the fact that it hardens very quickly after application, and that such property is closely related to the network-like structure of the hardened coat produced by the trifunctional isocyanate compound used in the present invention.
(3) It facilitates an improvement in the outward appearance of the coat.
Whilst the luster and build of a coat are related to various factors, the influence of the coating on the under coat is a factor which must not be left unheeded. With the compounds of this invention, it is possible to use a variety of solvents and, in particular, aromatic compound solvents may be used. This permits a reduction in the influence of the coating on the under coat, for instance, primer surface. That is, the permeation of the solvent is kept to the minimum, helping to achieve an improvement in the outward appearance of the coat. Thus, it is best suited for such purposes as coating of automobiles, etc., where an emphasis is placed on a good outward appearance.
(4) It contributes to development of coatings of the "high solid type".
Amidst the recent moves for restriction on environmental pollution, the development of polyurethane resin coatings of the "high solid type" or of the solventless type is attracting much attention in concerned circles. Isocyanate as an ingredient of such coatings is required to have, like the polyol ingredient, a low viscosity at room temperature. As the trifunctional isocycanate used in the present invention has a low molecular weight, it has a low viscosity, and hence may be intended for the manufacture of coatings in a manner that will help prevent environmental pollution. It is also possible, by proper choice of the polyols to be used, to manufacture solventless coatings and thus to contribute to savings in resources or energy. The coating of the present invention is, because of its low viscosity, excellent in respect of coating work efficiency, too.
(5) Hardening speed is excellent.
Although the hardening speed at room temperature is not so clearly different from that of the coating materials on the market, it becomes considerably greater than the latter upon a rise in baking temperature. Thus, it is possible to shorten the time required for curing.
(6) Low toxicity.
Hexamethylenediisocyanate prepolymers or adducts have, in general, a pretty strong and irritating odor. This is because, it is said, of the existence of a very small amount of hexamethylenediisocyanate monomer in the prepolymers or adducts. With, on the other hand, the trifunctional isocyanate compounds employed in the present invention, the vapor pressure is remarkably low, and there is no liberation of volatile, high toxicity, ingredients while they are kept in storage. Also, their NCO content is higher than that of the coating materials on the market. Therefore, the coating of this invention emits little irritating odor which is peculiar to the isocyanate content of coatings. As the proportion of the isocyanate ingredient to that of the polyol ingredient may, in view of its high NCO content, be reduced, it is quite advantageous from the viewpoint of hygiene.
The polyurethane resin of the present invention may be put to a wide range of uses in various fields of industries besides its use as a coating material as above noted.
For instance, those compounds with an NCO/OH mole percentage in the range of 0.5 to 1.0 may be used to advantage in such fields as electrical insulation and capsulation, and in the manufacture of cast products.
When the NCO/OH mole percentage is in the range of 0.1 to 0.7, such compounds may be advantageously utilized in the manufacture of highly efficient adhesives or hardening agents. When, on the other hand, the NCO/OH mole percentge is greater, such compounds are suited for the manufacture of foam products. The foaming may be achieved by introducing a certain fixed amount of water or a blowing agent into the reaction products, by utilization of well known foaming techniques.
The present invention will now be further illustrated in the following examples. However, it is to be noted that these examples are given merely to explain and not to limit the invention, and that numerous changes may be made in the examples without departing from the spirit and scope of the invention as defined in the appended claims.
Several examples of embodiments of the present invention are now recited and compared with a few comparative examples. The phrase "Part or parts", of the composition shown in the examples, means "part or parts by weight" unless noted otherwise.
PREPARATION OF 1,6,11-UNDECANETRIISOCYANATE
To a solution of 100 g of 1,6,11-undecanetriamine in 100 ml of methanol, 136 ml of concentrated (35 wt. percent) hydrochloric acid was added dropwise while cooling to maintain the reaction temperature at below 30° C. The reaction mixture was concentrated by means of a rotary evaporator in vacuo on a hot water bath to yield a thick oil. The oil, which on digestion with 500 ml of i-propyl alcohol was similarly concentrated, was evacuated at about 80° C. under a vacuum below 5 torr for 10 hrs. to give white solids of 1,6,11-undecanetriamine trihydrochloride. The solids thus obtained were crushed and pulverized in a mortar with a pestle under a dry atmosphere to result in a fine powder, having particle sizes of below 175 μm diameter and capable of passing through a screen of 80 mesh.
A four-necked, round-bottomed flask fitted with a mechanical stirrer, a thermometer, a gas inlet almost reaching the bottom of the flask, and a condenser, was charged with 66.5 g of this triamine hydrochloride powder and 665 ml of o-dichlorobenzene. The mixture was phosgenated by using a phosgene flow of approximately 30 g/hr. The reaction was started at 130° C. and gradually heated to 140° C. after 4 hours, then was maintained for 7 hours at 140° C. and further maintained for 4 hours at 150° C. As the reaction proceeds, the starting powder suspended in the mixture was dissolved. After cooling to room temperature and filtration, the solvent was distilled off at about 40° C. under reduced pressure of about 4 torr, and the product was distilled at 166° C. to 167° C. at 0.2 torr to give 47.2 g of 1,6,11-undecane triisocyanate:
n D 20 --1.4720
Analysis--Calc'd for C 14 H 21 N 3 O 3 (percent): C 60.19; H 7.58; N 15.05, Found C 59.89; H 7.55; N 14.82.
High-resolution MS--Cal'd for C 14 H 21 N 3 O 3 , M + /e=279.1584, Found M + /e=279.1585.
IR Spectra (cm -1 )--2940, 2869, 2260(NCO), 1460, 1360.
NMR Spectra (ppm)--1.45(singlet, 16H), 3.4(distorted triplet, 5H)
EXAMPLE 1
A vessel equipped with a mechanical stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube, was charged with the following solvents under a nitrogen atmosphere, and heated to 90°-95° C.
______________________________________Xylole 50 partsButylacetate 50 parts______________________________________
The following mixture was dripped in a constant rate over a period of 3 hours.
______________________________________Styrene 34.0 partsn-Butylacrylate 38.0 partsβ-Hydroxyl methacrylate 23.4 partsAcrylic acid 0.4 partsAzobisisobutyronitrile 1.2 parts______________________________________
After completion of dripping of the mixture, the mixture was maintained at 90°-95° C. for one hour, and then 0.7 parts of azobisisobutyronitrile were added 4 times at intervals of 30 minutes, and after that, the mixture was further held for one hour.
The resulting solution of acrylic polyol was a clear liquid and its Garnder Viscosity was T-U at 25° C. The total solids content was 50%. The OH Value of this solution was 50 and the calculated average OH value per one copolymer molecule was 12.9. The molecular weight (Mn) of this copolymer was 14,500.
This white enamel was diluted with a thinner composed of toluol and cellosolveacetate (50/50 wt %) with a settlement time of 18 seconds using Ford Cup No. 4. This diluted composition was sprayed onto zinc phosphate treated steel panels coated with primer surfacer No. 114 (Kansai Paint Co. Ltd.) and polished with sand paper, to form a smooth film at a dry film thickness of about 40ν. Panels thus coated were cured at room temperature (23° C.) for 7 days. The resulting films were tough and had excellent properties for acid resistance and warm water resistance as shown in Table 1. Also the exposure test results indicated no significant difference in yellowing resistance between the films of this example and coating film obtained by using commercially available aliphatic polyisocyanate, especially Desmodur N-75 (Bayer AG).
EXAMPLE 2
The apparatus of Example 1 was charged with the following solvents under an atmosphere of nitrogen, and heated to 80°-85° C.
______________________________________Xylole 80 partsButylacetate 20 parts______________________________________
The following mixture was dripped in at a constant rate over a period of 3 hours.
______________________________________Styrene 25.0 partsMethyl methacrylate 25.0 partsn-Butylmethacrylate 21.0 partsn-Butylacrylate 14.0 partsβ-Hydroxylmethacrylate 12.0 partsAcrylic acid 0.7 partsAzobisisobutyronitrile 1.2 parts______________________________________
After completion of dripping of the mixture, the mixture was maintained at 80°-85° C. for 2 hours, and then 0.5 parts of azobisisobutyronitrile were added 4 times at intervals of 2 hours. After that, the mixture was held for further for 3 hours. The resulting acrylic polyol solution was a clear liquid and its Gardner Viscosity was V-W at 25° C., the total solids content was 50%. The molecular weight (Mn) of the copolymer was 11,700, and the OH value of the solution was 25. Accordingly the calculated average OH value per one copolymer molecule was 5.2.
Using the same method described in Example 1, 1,6,11-undecanetriisocyanate and a panel was coated therewith, followed by curing of the resin. The resulting film exhibited excellent performance in uniform high gloss, higher reactivity with polyol, acid resistance and warm water resistance as shown in Table 2. The yellowing resistance of the exposure test film was as good as the film obtained by using an available aliphatic polyisocyanate.
COMPARATIVE EXAMPLES 1-2
In these Examples, the paint and its curing film were prepared using "Desmodur N-75" (the biuret type based on hexamethylene diisocyanate, registered trademark of Bayer AG) instead of 1,6,11-undecanetriisocyanate as used in Examples 1 and 2. The properties of the films were compared in Tables 1 and 2.
White enamel was prepared by mixing following two polyol components with "Desmodur N-75" at an NCO/OH ratio of 1.0. The polyol components were prepared by mixing each of the acrylic polyols obtained in Examples 1 and 2 with TiO 2 "R-930" (registered trademark of Ishihara Sangyo Kaisha, Ltd.) glass beads using a Paint Conditioner (shaker). The white enamel compositions thus obtained were diluted to a settlement time of 18 seconds using Ford Cup No. 4 and then the diluted compositions were coated onto steel panels by the same method as in Example 1.
The paints in accordance with the present invention were higher in non-volatility properties at spray operation (thus saving raw materials), and they exhibited good compatibility with the solvents. The cured films, in accordance with the invention, had approximately the same level of practical properties as the films obtained by using "Desmodur N-75", but exhibited excellent acid resistance in contrast to the "Desmodur N-75" films.
TABLE 1__________________________________________________________________________ Example 1 Comparative Example 2 Comparative 1,6,11- Example 1 1,6,11- Example 2Test Undecane- "Desmodur Undecane- "DesmodurItems Condition triisocyanate N-75" triisocyanate N-75"__________________________________________________________________________Initial hardness rate ○ ○ ○ ○Gloss 60° 95 92 93 93Pencil hardness F F F FImpact resistance Du Pont 30 cm 30 cm 25 cm 20 cm1/2", 1000 gErichsen 7.0 mm 6.5 mm 7.7 mm 7.5 mmAdhesion Cross Cut 100/100 100/100 100/100 100/100Warm water resistance 50° C. × 24 hr ○ Δ ○ ΔAcid resistance 40 vol % H.sub.2 SO.sub.4 ○ x ○ x 55° C. × 5 hrSolvent resistance Naphtha No. 5/ ○ ○ ○ ○ toluol = 6/4 dipping for 10 min " Xylole rubbing ○ ○ Δ Δ 30 timesYellowing index (YI) UV* 0 hr 2.5 3.2 2.8 3.0 " UV* 200 hr 10.0 12.1 9.6 11.2YI 200 hr 7.6 8.9 7.4 8.2E (Lab) 200 hr 5.0 5.5 5.5 5.0__________________________________________________________________________ Legend *Sterilization Lamp GL 15 (15 W) made by Tokyo Shibaura Electric Co., Ltd., wave length: 254 mm, radiation strength from distance 20 cm: 600 Pigmentation: PWC 50% Curing condition: 23° C. × 7 days Evaluated level sign: ⊚ excellent ○ good Δ fair x poor
TABLE 2______________________________________ Compar- Compar- ative ative Example 1 Example 1 Example 2 Example 2______________________________________polyol 50 50 25 25OH valueIsocya- 1,6,11- "Desmodur 1,6,11- "Desmodurnate Undecane N-75" Undecane N-75" triiso- triiso- cyanate cyanateTest itemsCompatibilitytoluol/cello- ○ ○ ○ ○solve acetate50:50toluol ○ Δ ○ Δ (slightly (slightly opaque) opaque)Film ⊚ ○ ⊚ ○appearance*Spraying 55% 49% 54% 48%solids contentFord CupNo. 420 seconds______________________________________ *used a thinner comprising toluol and cellosolve acetate (50/50) Pigmentation: PWC 50% Curing condition: room temp (23° C.) × 7 days Substrate: Zinc phosphate treated steel coated with primer surfacer No. 114 and polished with sand paper Evaluated level sign: same as Table 1
EXAMPLE 3
Polyester polyol was prepared from the following mixture:
______________________________________Neopentyl glycol 126.9 partsTrimethylol propane 22.1 partsAdipic acid 72.3 partsisophthalic acid 123.2 parts______________________________________
This mixture was charged into a vessel and heated to 200° C. for 30 minutes with stirring. Then until the Gardner viscosity raised to F, while the acid value decreased to about 10 and the OH value decreased to about 100 in a MEK solution (N.V.=60%), the mixture was maintained for about 15 minutes. After that, this mixture was cooled and diluted with MEK solvent to a non-volatility property of 60%, and thus the polyester polyol solution was obtained.
Then, this solution and 1,6,11-Undecanetriisocyanate were mixed uniformly at an NCO/OH ratio of 1.0. This composition was coated onto a substrate and cured. The resulting film had high gloss and excellent mechanical properties.
Although this invention has been described with reference to certain particular processing conditions, compounds, and other parameters, it will be appreciated that many variations may be made without departing from the spirit and scope of the invention as defined in the appended claims. | Polyurethane resins and polyurethane coating compositions are provided which exhibit enhanced resistance to weather. The resins comprise the reaction product obtained from reacting a polyol with 1,6,11-undecanetriisocyanate. The resin composition herein disclosed is readily adapted for use in either a one component-heat curing system or in a two component-polyol hardening system. In the one component system, the isocyanate group of the isocyanate compound is blocked by a blocking agent so as to ensure stability of the coating at room temperature. After application, the coating resin is heated to effect reaction of a hydroxyl group from the polyol with an isocyanate group to cause hardening of the film. In the two component system, the polyol-pigment liquid, liquid "A", is mixed with the trifunctional isocyanurate compound (above noted) and solvent, liquid "B". | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent Application No. 10-2007-0015552 filed with the Korean Intellectual Property Office on Feb. 14. 2007., the disclosures of which are incorporated herein by reference in their entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to a hydrogen generating apparatus, more particularly to a hydrogen generating apparatus that can control the amount of generation of hydrogen supplied to a fuel cell.
[0004] 2. Description of the Related Art
[0005] A fuel cell refers to an energy conversion apparatus that directly converts chemical energy of a fuel (hydrogen, LNG, LPG, methanol, etc.) and air to electricity and/or heat by means of an electrochemical reaction. Unlike a conventional power generation technology that requires fuel combustion, steam generation, or a turbine or power generator, the fuel cell technology needs no combustion process or driving device, thereby boosting energy efficiency and curbing environmental problems.
[0006] FIG. 1 illustrates an operational architecture of a fuel cell.
[0007] Referring to FIG. 1 , a fuel cell 100 is composed of an anode as a fuel pole 110 and a cathode as an air pole 130 . The fuel pole 110 is provided with hydrogen molecules (H 2 ), and decomposes them into hydrogen ions (H + ) and electrons (e − ). The hydrogen ion (H + ) moves toward the air pole 130 via a membrane 120 , which is an electrolyte layer. The electron moves through an external circuit 140 to generate an electric current. In the air pole 130 , the hydrogen ions and the electrons are combined with oxygen molecules in the atmosphere, generating water molecules. The following chemical formulas represent the above chemical reactions occurring in the fuel cell 100 .
[0008] CHEMICAL FORMULA 1
[0009] Fuel pole 110 : H 2 →2H + +2e −
[0010] Air pole 130 : ½O 2 +2H + +2e − →H 2 O
[0011] Overall reaction: H 2 +½O 2 →H 2 O
[0012] In short, the fuel cell 100 functions as a battery by supplying the electric current, generated due to the flowing of the decomposed electrons, to the external circuit 140 . Such a fuel cell 100 hardly emits an atmospheric pollutant such as Sox and NOx and makes little noise and vibration.
[0013] Meanwhile, in order to produce electrons in the fuel pole 110 , the fuel cell 100 necessitates a hydrogen generating apparatus that can change a common fuel to hydrogen gas.
[0014] A hydrogen storage tank, generally known as a hydrogen generating apparatus, however, occupies a large space and should be kept with care.
[0015] Moreover, as a portable electronic device, such as a mobile phone and a notebook computer, requires a large capacity of power, it is necessary that the fuel cell have a large capacity and perform high performance while it is small.
[0016] In order to meet the above needs, methanol or formic acid, permitted to be brought into an airplane by International Civil Aviation Organization (ICAO), is used for fuel reforming, or methanol, ethanol, or formic acid is directly used as a fuel for the fuel cell.
[0017] However, the former case requires a high reforming temperature, has a complicated system, consumes driving power, and contains impurities (e.g., CO 2 and CO) in addition to pure hydrogen. The latter case deteriorates power density due to a low rate of a chemical reaction in the anode and a cross-over of hydrocarbon through the membrane.
SUMMARY
[0018] The present invention provides a hydrogen generating apparatus that can generate hydrogen by using an environment-friendly material instead of a BOP (Balance of Plant) unit consuming separate power and difficult to be miniaturized.
[0019] Also, the present invention provides a cost-effective hydrogen generating apparatus that can have a simple structure and generate pure hydrogen under room temperature by using an electrochemical reaction.
[0020] In addition, the present invention provides a hydrogen generating apparatus that can control the amount of hydrogen generation by controlling the amount of the electric current between electrodes according to the demand of a user or a fuel cell. Therefore, the present invention can be applied to a mobile device, in which power consumption varies depending on circumstances.
[0021] An aspect of the present invention features a hydrogen generating apparatus. The apparatus can comprise an electrolyzer that is filled with an aqueous electrolyte solution containing hydrogen ions; a first electrode that is accommodated in the electrolyzer, submerged in the aqueous electrolyte solution, and generates electrons; a second electrode that is accommodated in the electrolyzer, submerged in the aqueous electrolyte solution, and receives the electrons to generate hydrogen; and a control unit that is disposed between the first electrode and the second electrode, and controls the amount of electrons transferred from the first electrode to the second electrode.
[0022] The control unit can control the amount of electrons in accordance with information inputted by a user.
[0023] The hydrogen generating apparatus can be coupled with a fuel cell, to which the hydrogen is supplied, and the control unit controls the amount of electrons in accordance with information on the amount of hydrogen or power demanded for the fuel cell.
[0024] A metal forming the first electrode can have a higher ionization tendency than a metal forming the second electrode.
[0025] The first electrode or the second electrode can be disposed in plural number.
[0026] Another aspects of the present invention features a fuel cell power generation system can comprise a hydrogen generating apparatus that controls the amount of hydrogen generation by adjusting the amount of electrons transferred between electrodes; and a fuel cell that receives hydrogen generated in the hydrogen generating apparatus, and produces a direct current by converting chemical energy of the hydrogen to electric energy.
[0027] The hydrogen generating apparatus can comprise an electrolyzer that is filled with an aqueous electrolyte solution containing hydrogen ions; a first electrode that is accommodated in the electrolyzer, submerged in the aqueous electrolyte solution, and generates electrons; a second electrode that is accommodated in the electrolyzer, submerged in the aqueous electrolyte solution, and generates hydrogen by receiving the electrons; and a control unit that is disposed between the first electrode and the second electrode, and controls the amount of electrons transferred from the first electrode to the second electrode.
[0028] The control unit can control the amount of the electrons in accordance with information inputted by a user.
[0029] The control unit can control the amount of electrons in accordance with information on the amount of hydrogen or power demanded for the fuel cell.
[0030] A metal forming the first electrode can have a higher ionization tendency than a metal forming the second electrode.
[0031] The first electrode or the second electrode can be disposed in plural number.
[0032] Additional aspects and advantages of the present general inventive concept will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the general inventive concept.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
[0034] FIG. 1 illustrates an operational architecture of a fuel cell;
[0035] FIG. 2 shows a sectional view of a hydrogen generating apparatus in accordance with an embodiment of the present invention;
[0036] FIG. 3 is a graph showing how the amount of electric current between a first electrode and a second electrode and the amount of generated hydrogen are related in a hydrogen generating apparatus in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
[0037] Since there can be a variety of permutations and embodiments of the present invention, certain embodiments will be illustrated and described with reference to the accompanying drawings. This, however, is by no means to restrict the present invention to certain embodiments, and shall be construed as including all permutations, equivalents and substitutes covered by the spirit and scope of the present invention. Throughout the drawings, similar elements are given similar reference numerals. Throughout the description of the present invention, when describing a certain technology is determined to evade the point of the present invention, the pertinent detailed description will be omitted.
[0038] Terms such as “first” and “second” can be used in describing various elements, but the above elements shall not be restricted to the above terms. The above terms are used only to distinguish one element from the other. For instance, the first element can be named the second element, and vice versa, without departing the scope of claims of the present invention. The term “and/or” shall include the combination of a plurality of listed items or any of the plurality of listed items.
[0039] When one element is described as being “connected” or “accessed” to another element, it shall be construed as being connected or accessed to the other element directly but also as possibly having another element in between. On the other hand, if one element is described as being “directly connected” or “directly accessed” to another element, it shall be construed that there is no other element in between.
[0040] The terms used in the description are intended to describe certain embodiments only, and shall by no means restrict the present invention. Unless clearly used otherwise, expressions in the singular number include a plural meaning. In the present description, an expression such as “comprising” or “consisting of” is intended to designate a characteristic, a number, a step, an operation, an element, a part or combinations thereof, and shall not be construed to preclude any presence or possibility of one or more other characteristics, numbers, steps, operations, elements, parts or combinations thereof.
[0041] Unless otherwise defined, all terms, including technical terms and scientific terms, used herein have the same meaning as how they are generally understood by those of ordinary skill in the art to which the invention pertains. Any term that is defined in a general dictionary shall be construed to have the same meaning in the context of the relevant art, and, unless otherwise defined explicitly, shall not be interpreted to have an idealistic or excessively formalistic meaning.
[0042] Hereinafter, certain embodiments will be described in detail with reference to the accompanying drawings. Identical or corresponding elements will be given the same reference numerals, regardless of the figure number, and any redundant description of the identical or corresponding elements will not be repeated.
[0043] FIG. 2 is a sectional view of a hydrogen generating apparatus in accordance with an embodiment of the present invention.
[0044] A hydrogen generating apparatus 200 includes an electrolyzer 210 , a first electrode 220 , a second electrode 230 and a control unit 240 . For the convenience of description and understanding, it will be presumed below that the first electrode 220 is composed of magnesium (Mg) and the second electrode 230 is composed of stainless steel.
[0045] The electrolyzer 210 is filled with an aqueous electrolyte solution 215 . The aqueous electrolyte solution 215 contains hydrogen ions, which are used by the hydrogen generating apparatus 200 to generate hydrogen gas.
[0046] Examples of the electrolyte for the aqueous electrolyte solution 215 are LiCl, KCl, NaCl, KNO 3 , NaNO 3 , CaCl 2 , MgCl 2 , K 2 SO 4 , Na 2 SO 4 , MgSO 4 , AgCl, or the like.
[0047] The electrolyzer 210 accommodates the first electrode 220 and the second electrode 230 , the entirety or portions of which are submerged in the electrolyte solution 215 .
[0048] The first electrode 220 is an active electrode, where the magnesium (Mg) is oxidized to magnesium ions (Mg 2+ ), releasing electrons due to the difference in ionization energies of magnesium and water. The released electrons move to the second electrode 230 through a first electric wire 225 , the control unit 240 and a second electric wire 235 .
[0049] The second electrode 230 is an inactive electrode, where the water molecules receive the electrons moved from the first electrode 220 and then are decomposed into the hydrogen molecules.
[0050] The above chemical reactions can be represented as the following chemical formula 2:
[0051] CHEMICAL FORMULA 2
[0052] First electrode 220 : Mg→Mg 2+ +2e −
[0053] Second electrode 230 : 2H 2 O+2e − →H 2 +2(OH) −
[0054] Overall reaction: Mg+2H 2 O→Mg(OH) 2 +H 2
[0055] The reaction rate and the efficiency of the chemical reaction depend on various factors, including the area of the first electrode 220 and/or the second electrode 230 , the concentration of the aqueous electrolyte solution 215 , the type of the aqueous electrolyte solution 215 , the number of the first electrode 220 and/or the second electrode 230 , the method of connecting the first electrode 220 and the second electrode 230 , the electric resistance between the first electrode 220 and the second electrode 230 .
[0056] Changing any of the above factors affects the amount of electric current (that is, the amount of electrons) flowing between the first electrode 220 and the second electrode 230 , thereby altering the reaction rate of the electrochemical reaction shown in CHEMICAL FORMULA 2, which in turn changes the amount of hydrogen generated in the second electrode 230 .
[0057] Therefore, the amount of the hydrogen generated in the second electrode 230 can be controlled by controlling the amount of the electric current that flows between the first electrode 220 and the second electrode 230 . Faraday's law explains this as shown in MATHEMATICAL FORMULA 1 below.
[0000]
N
hydrogen
=
i
nE
N
hydrogen
=
i
2
×
96485
(
mol
)
V
hydrogen
=
i
2
×
96485
×
60
×
22400
(
ml
/
min
)
=
7
×
i
(
ml
/
min
)
MATHEMATICAL
FORMULA
1
[0058] where N hydrogen is the amount of hydrogen generated per second (mol/s), V hydrogen is the volume of hydrogen generated per minute (ml/min), i is the electric current (C/s), n is the number of the reacting electrons, and E is the electron charge per mole (C/mol).
[0059] In the case of the above CHEMICAL FORMULA 2, n has a value of 2 since two electrons react at the second electrode 230 , and E has a value of −96,485 C/mol.
[0060] The volume of hydrogen generated per minute can be calculated by multiplying the time (60 seconds) and the molar volume of hydrogen (22400 ml) to the amount of hydrogen generated per second.
[0061] For example, in the case that the fuel cell is used in a 2 W system, it takes 42 ml/mol of hydrogen and 6 A of electric current. However, in the case that the fuel cell is used in a 5 W system, it takes 105 ml/mol of hydrogen and 15 A of electric current.
[0062] The hydrogen generating apparatus 200 can meet the variable hydrogen demand of the fuel cell connected thereto by controlling the amount of electric current flowing through the first electric wire 225 , connected to the first electrode 220 , and the second electric wire 235 , connected to the second electrode 230 .
[0063] However, most of the factors that determine the rate of the hydrogen generation reaction occurring in the second electrode of the hydrogen generating apparatus 200 , except the electric resistance between the first electrode 220 and the second electrode 230 , are hardly changeable once the hydrogen generating apparatus 200 is manufactured.
[0064] Therefore, the hydrogen generating apparatus 200 according to this embodiment of the present invention has the control unit 240 disposed between the first electric wire 225 and the second electric wire 235 , which connect the first electrode 220 and the second electrode 230 , in order to regulate the electric resistance between the first electrode 220 and the second electrode 230 .
[0065] Thus, the hydrogen generating apparatus 200 controls the electric resistance between the first electrode 220 and the second electrode 230 , that is, the amount of the electric current flowing therebetween, thereby generating as much hydrogen as needed by the fuel cell.
[0066] The first electrode 220 can be also composed of a metal having a relatively high ionization tendency, such as iron (Fe), aluminium (Al), zinc (Zn), or the like. The second electrode 230 can be also composed of a metal having a relatively low ionization tendency compared to the metal of the first electrode 220 , such as platinum (Pt), aluminum (Al), copper (Cu), gold (Au), silver (Ag), iron (Fe), or the like.
[0067] The control unit 240 controls a transfer rate, that is, the amount of electric current, at which electrons generated in the first electrode 220 are transferred to the second electrode 230 .
[0068] The control unit 240 receives information on the amount of power or hydrogen demanded for the fuel cell and, according to the information, controls the amount of electrons flowing from the first electrode 220 to the second electrode 230 . If the demanded amount of power or hydrogen is large, the control unit 240 increases the amount of electrons, and the control unit 240 reduces the amount of the electrons if the demanded amount of power or hydrogen is small.
[0069] For example, the control unit 240 includes an adjustable resistor as its component, and controls the resistance of the adjustable resistor, thereby adjusting the amount of the electric current flowing between the first electrode 220 and the second electrode 230 . For another example, the control unit 240 has an ON/OFF switch, which controls a timing of on/off operation, thereby adjusting the amount of the electric current between the first electrode 220 and the second electrode 230 .
[0070] The hydrogen generating apparatus 200 can receive the information on the amount of the power or the hydrogen demanded for the fuel cell from the fuel cell combined with the hydrogen generating apparatus 200 or from a user, who inputs the information through a separate input unit.
[0071] The hydrogen generating apparatus of the present invention can have a plurality of the first electrodes 220 and/or the second electrodes 230 . In the case that a plural number of the first electrode 220 and/or the second electrode 230 are disposed, it can take a shorter time to generate the demanded amount of hydrogen since the hydrogen generating apparatus 200 can generate more hydrogen per unit time.
[0072] FIG. 3 is a graph showing how the amount of electric current flowing between the first electrode 220 and the second electrode 230 is related to the volume of hydrogen generated on the second electrode 230 . Here, it should be noted that the volume of hydrogen is shown in flow-rate measured per minute, because not the total volume of generated hydrogen but the flow-rate of hydrogen is significant to a fuel cell.
[0073] An experiment for FIG.3 was conducted under the following conditions:
[0074] First electrode 220 : Magnesium (Mg)
[0075] Second electrode 230 : Stainless steel
[0076] Distance between the electrodes: 3 mm
[0077] Ingredients and concentration of electrolyte: 30 wt % KCl
[0078] Nnumber of the electrodes: Magnesium 3 each, Stainless steel 3each
[0079] Electrode connecting method: Serial
[0080] Volume of aqueous electrolyte solution: 60 cc (excessive condition)
[0081] Size of the electrode: 24 mm×85 mm×1 mm
[0082] FIG. 3 shows a greater flow rate of the hydrogen than a theoretical value based on MATHEMATICAL FORMULA 1, due to an interaction of the three pairs of electrodes.
[0083] Nevertheless, it is verified from FIG. 3 that the flow-rate of hydrogen is correlated with the amount of electric current between the first electrode 220 and the second electrode 230 . Also, the graph shows an almost linear relation between the flow-rate and the amount of the electric current, which agrees with the MATHEMATICAL FORMULA 1.
[0084] While the invention has been described with reference to the disclosed embodiments, it is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the invention or its equivalents as stated below in the claims. | An aspect of the present invention features a hydrogen generating apparatus. The apparatus can comprise an electrolyzer that is filled with an aqueous electrolyte solution containing hydrogen ions; a first electrode that is accommodated in the electrolyzer, submerged in the aqueous electrolyte solution, and generates electrons; a second electrode that is accommodated in the electrolyzer, submerged in the aqueous electrolyte solution, and receives the electrons to generate hydrogen; and a control unit that is disposed between the first electrode and the second electrode, and controls the amount of electrons transferred from the first electrode to the second electrode. The hydrogen generating apparatus according to the present invention can control the amount of hydrogen generation by controlling the amount of the electric current between electrodes according to the demand of a user or a fuel cell. Therefore, the present invention can be applied to a mobile device, in which power consumption varies depending on circumstances. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is related to the following applications, filed on even date herewith, with the disclosures of each the applications being incorporated by reference herein in their entireties:
[0002] Application Ser. No. ______ (Attorney Docket No. P31213), filed on even date herewith, entitled “Tire Compositions And Components Containing Silated Cyclic Core Polysulfides”.
[0003] Application Ser. No. ______ (Attorney Docket No. P31214), filed on even date herewith, entitled “Tire Compositions And Components Containing Free-Flowing Filler Compositions”.
[0004] Application Ser. No. ______ (Attorney Docket No. P31215), filed on even date herewith, entitled “Tire Compositions And Components Containing Free-Flowing Filler Compositions”.
[0005] Application Ser. No. ______ (Attorney Docket No. P31216), filed on even date herewith, entitled “Tire Compositions And Components Containing Silated Core Polysulfides”.
[0006] Application Ser. No. ______ (Attorney Docket No. P31217), filed on even date herewith, entitled “Tire Compositions And Components Containing Blocked Mercaptosilane Coupling Agent”.
[0007] Application Ser. No. ______ (Attorney Docket No. US194234), filed on even date herewith, entitled “Silated Cyclic Core Polysulfides, Their Preparation And Use In Filled Elastomer Compositions”.
[0008] Application Ser. No. ______ (Attorney Docket No. US194914), filed on even date herewith, entitled “Free-Flowing Filler Composition And Rubber Composition Containing Same”.
[0009] Application Ser. No. ______ (Attorney Docket No. US194915), filed on even date herewith, entitled “Free-Flowing Filler Composition And Rubber Composition Containing Same”.
[0010] Application Ser. No. ______ (Attorney Docket No. US193438), filed on even date herewith, entitled “Silated Core Polysulfides, Their Preparation And Use In Filled Elastomer Compositions”.
[0011] The present application is directed to an invention which was developed pursuant to a joint research agreement wherein the meaning of 35 U.S.C. §103(c). The joint research agreement dated May 7, 2001 as amended, between Continental AG, and General Electric Company, on behalf of GE Advanced Materials, Silicones Division, now Momentive Performance Materials Inc.
BACKGROUND OF THE INVENTION
[0012] This invention relates to sulfur silane coupling agents containing multiple blocked mercapto groups which are latent, that is, they are in a state of reduced activity until such a time as one finds it useful to activate them. The invention also relates to the manufacture of mineral filled elastomers, rubbers and inorganic fillers comprising these silane coupling agents, as well as to the manufacture of the silanes.
[0013] The majority of art dealing with of sulfur-containing coupling agents in mineral filled elastomers involves silanes containing one or more of the following chemical bond types:
[0014] S—H (mercapto), S—S (disulfide or polysulfide), C═S (thiocarbonyl) or C(═O)S (thioester). Mercaptosilanes have high chemical reactivity with organic polymers used in mineral filled elastomers and therefore effect coupling at substantially reduced loadings. However, these chemical bonds between the coupling agent and the organic polymer are weaker than the carbon-carbon bonds of the organic polymer. Under high stress and/or high frequency use conditions, these chemical bonds are susceptible to breakage and, therefore, loss of coupling between the organic polymer and the coupling agent. The loss of coupling may contribute to the wear and to the degradation of other elastomeric physical properties. The high chemical reactivity of mercaptosilane coupling agents with organic polymers also leads to unacceptably high viscosities during processing and premature curing (scorch). Their undesirability is aggravated by their odor. As a result, other, less reactive coupling agents such as the coupling agents that contain the S—S (disulfide and polysulfide), C═S (thiocarbonyl) or C(═O)S (thioester) functional groups are used. Because these silane coupling agents are less reactive with the organic polymers, they require higher use levels and often do not achieve the same level of bonding. Similar to the mercaptosilane coupling agents, these sulfur silanes are bonded to the organic polymer through a C—S bond.
[0015] The prior art discloses acylthioalkyl silanes, such as CH 3 C(═O)S(CH 2 ) 1-3 Si(OR) 3 (M. G. Voronkov et al. in Inst. Org. Khim ., Irkutsk, Russia) and HOC(═O)CH 2 CH 2 C(═O)S(CH 2 ) 3 Si(OC 2 H 5 ) 3 (U.S. Pat. No. 3,922,436 to R. Bell et al.). Takeshita and Sugawara disclosed in Japanese Patent JP 63270751 A2 the use of compounds represented by the general formula CH 2 ═C(CH 3 )C(═O)S(CH 2 ) 1-6 Si(OCH 3 ) 3 in tire tread compositions; but these compounds are not desirable because the unsaturation α,β to the carbonyl group of the thioester has the undesirable potential to polymerize during the compounding process or during storage. Prior art by Yves Bomal and Olivier Durel in Australian Patent AU-A-10082/97 discloses the use in rubber of silanes of the structure represented by R 1 n X 3-n Si-(Alk) m (Ar) p —S(C═O)—R (Formula 1P) where R 1 is phenyl or alkyl; X is halogen, alkoxy, cycloalkoxy, acyloxy, or OH; Alk is alkyl; Ar is aryl; R is alkyl, alkenyl, or aryl; n is 0 to 2; and m and p are each 0 or 1, but not both zero. This prior art, however, stipulates that compositions of the structures of Formula (1P) must be used in conjunction with functionalized siloxanes. The prior art does not disclose or suggest the use of compounds of Formula (1P) as latent mercaptosilane coupling agents, nor does it disclose or suggest the use of these compounds in any way that would give rise to the advantages of using them as a source of latent mercaptosilane. In addition, these patents do not describe coupling agent that have multiple thioester groups in the appropriate stereochemical configuration to foster multiple linkages to the organic polymer.
[0016] U.S. Pat. Nos. 6,608,125; 6,683,135; 6,20439; 6,127,468; 6,777,569; 6,528,673 and 6,649,684, US Patent Publication Nos. US20050009955A1, 20040220307A1, 2003020900A1, 20030130388A1, and application Ser. Nos. 11/105,916 and 10/128,804, and European patent application EP1270657A1 teach the use of blocked mercaptosilanes of the structure represented by [[ROC(═O)) p -(G) j ] k —Y—S] r -G-(SiX 3 ) s , where Y is a polyvalent blocking group (Q) z A(=E) and r is an integer 1 to 3 in rubber compounds and s is preferably 1 to 3, in rubber master batches and as a surface treatment for mineral fillers and how to manufacture the silane. Although these patents and patent applications disclose structures that possess more than one blocked mercapto group, i.e. r=2 or 3, they do not teach the specific stereochemical configurations of the polyvalent G structure between the silicon atom and the organofunctional group necessary to achieve the efficient multiple bonding between the coupling agent and the organic polymer.
[0017] U.S. Pat. Nos. 4,519,430 to Ahmad et al. and 4,184,998 to Shippy et al. disclose the blocking of a mercaptosilane with an isocyanate to form a solid which is added to a tire composition, which mercaptan reacts into the tire during heating, which could happen at any time during processing since this is a thermal mechanism. The purpose of this silane is to avoid the sulfur smell of the mercaptosilane, not to improve the processing of the tire. Moreover, the isocyanate used has toxicity issues when used to make the silane and when released during rubber processing.
[0018] U.S. Pat. No. 3,957,718 to Porchet et al. discloses compositions containing silica, phenoplasts or aminoplasts, and silanes, such as xanthates, thioxanthates, and dithiocarbamates; however, the prior art does not disclose or suggest the use of these silanes as latent mercaptosilane coupling agents, nor does it suggest or disclose the advantage of using them as a source of latent mercaptosilane.
[0019] U.S. Pat. Nos. 6,359,046; 5,663,226; 5,780,531; 5,827,912; 5,977,225; 4,709,065; 6,759,545 and WO 2004000930A1 disclose a class of polysulfide silane coupling agents that contain more than one S—S (disulfide or polysulfide) functional groups per molecule. However, the multiple S—S linkages are achieved by separating the functional groups with an organic hydrocarbon radical. In use, these S—S groups decompose to form sulfur radicals that couple to the polymer, but generate species that contain only one sulfur reactive group per silicon atom. Dittrich, et al. in U.S. Pat. Nos. 5,110,969 and 6,268,421 and Weller, et al., overcame this feature. They disclosed structures that contain more than one sulfur functional group directly attached to silicon atom through a cyclic hydrocarbon radical. The multiple S—S groups were bonded to adjacent carbon atoms and the silicon atoms were directly attached to the rings through hydrosilation of the alkoxysilane to a vinyl containing cyclic hydrocarbons. However, these compounds contained rings of S—S and carbon atoms or were polymeric materials wherein the silyl containing hydrocarbon radicals were connected through S—S groups. These cyclic or polymeric coupling agents were rendered less reactive with the organic polymers because they contained S—S groups attached directly to secondary carbons. The attachment of the S—S containing group to secondary carbon atoms sterically hinder the reaction of the S—S groups and inhibit their reactions with the organic polymers.
[0020] Therefore, a need exists for latent coupling agents that have low reactivity to affect processing of the mineral filled elastomers or rubbers without scorch and can be activated at the desired time to form multiple linkages with the organic polymer. These multiple linkages provide sufficient bonding so that the loss of coupling between the rubber and coupling agent is minimized during high stress or frequency use conditions, such as is experienced by tires, without exhibiting the disadvantages such as described herein.
BRIEF DESCRIPTION OF THE INVENTION
[0021] The present invention is directed to the composition, manufacture and use of blocked mercaptosilane derivatives in which more than one mercapto group is directly linked to the silicon atom through carbon-carbon bonds and in which the mercapto group is blocked (“blocked mercaptosilanes”), i.e., the mercapto hydrogen atom is replaced by another group (hereafter referred to as “blocking group”). Specifically, the silanes of the present invention are blocked mercaptosilanes in which the blocking group contains an unsaturated heteroatom or carbon chemically bound directly to sulfur via a single bond. The use of these silanes in the manufacture of inorganic filled rubbers is taught wherein they are deblocked by the use of a deblocking agent during the manufacturing process. The uses of these silanes in the preparation of masterbatches and treated fillers and the manufacture of such silanes are taught as well.
[0022] More particularly, the present invention is directed to blocked mercaptosilane compositions comprising at least one component having the chemical structure in formula (I) consisting of:
[0000] [R k —Y—S(CH 2 ) n ] r -G-(CH 2 ) m —(SiX 1 X 2 X 3 ) (1)
[0000] wherein
[0023] each occurrence of Y is a polyvalent species (Q) z A(=E), preferably selected from the group consisting of —C(═NR 1 )—; —SC(═NR 1 )—; —SC(═O)—; (—NR 1 )C(═O)—; (—NR 1 )C(═S)—; —OC(═O)—; —OC(═S)—; —C(═O)—; —SC(═S)—; —C(═S)—; —S(═O)—; —S(═O) 2 —; —OS(═O) 2 —; (—NR 1 )S(═O) 2 —; —SS(═O)—; —OS(═O)—; (—NR 1 )S(═O)—; —SS(═O) 2 —; (—S) 2 P(═O)—; -(—S)P(═O)—; —P(═O)(—) 2 ; (—S) 2 P(═S)—; -(—S)P(═S)—; —P(═S)(−) 2 ; (—NR 1 ) 2 P(═O)—; (—NR 1 )(—S)P(═O)—; (—O)(—NR 1 )P(═O)—; (—O)(—S)P(═O)—; (—O) 2 P(═O)—; -(—O)P(═O)—; -(—NR 1 )P(═O)—; (—NR 1 ) 2 P(═S)—; (—NR 1 )(—S)P(═S)—; (—O)(—NR 1 )P(═S)—; (—O)(—S)P(═S)—; (—O) 2 P(═S)—; -(—O)P(═S)—; and -(—NR 1 )P(═S)—;
[0024] wherein each atom (A) attached to the unsaturated heteroatom (E) is attached to the sulfur, which in turn is linked via a group —(CH 2 ) n G(CH 2 ) m — to the silicon atom;
[0025] each occurrence of R is chosen independently from hydrogen, straight, cyclic, or branched alkyl, alkenyl groups, aryl groups, and aralkyl groups, with each R containing up to about 18 carbon atoms;
[0026] each occurrence of R 1 is chosen independently from hydrogen, alkyl, alkenyl, aryl or aralkyl groups with each R 1 containing up to about 18 carbon atoms;
[0027] each occurrence of G is chosen independently from a group consisting of a trivalent or polyvalent hydrocarbon group of 3 to 30 carbon atoms derived by substitution of alkane, alkene or aralkane or a trivalent or polyvalent heterocarbon group of 2 to 29 carbon atoms with the proviso that G contains a cyclic structure (ring);
[0028] each occurrence of X 1 is independently selected from the set of hydrolysable groups group consisting of —Cl, —Br, R 1 O—, R 1 C(═O)O—, R 1 2 C═NO—, R 1 2 NO— or R 2 N—, wherein each R 1 is as above;
[0029] each occurrence of X 2 and X 3 are independently chosen from the group consisting of the members listed for R 1 and X 1 ;
[0030] each occurrence of Q is selected independently from oxygen, sulfur, or (—NR—);
[0031] each occurrence of A is selected independently from carbon, sulfur, phosphorus, or sulfonyl;
[0032] each occurrence of E is selected independently from oxygen, sulfur, or NR 1 ;
[0033] k is 1 to 2; m=1 to 5; n=1 to 5; r is 2 to 4; z is 0 to 2; with the proviso that if A is phosphorus, then k is 2.
[0034] In another embodiment, the present invention is directed to a process for the preparation of the blocked mercaptosilane comprising reacting a thioacid with a silylated hydrocarbon containing r terminal carbon-carbon double bonds.
[0035] In another embodiment, the present invention is directed to a process for the preparation of the blocked mercaptosilane comprising reacting a salt of a thioacid with a silane containing r haloalkyl groups, wherein the halogen is attached to a primary carbon atom.
[0036] In still another embodiment, the present invention is directed to filled elastomer or rubber compound comprising the blocked mercaptosilanes of the present invention.
[0037] In another embodiment, the present invention is directed to a treated filler in which the treated filler comprises the blocked mercaptosilane of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Silane Structures
[0038] The novel blocked mercaptosilanes of the present invention can be represented by the Formula (I):
[0000] [R k —Y—S(CH 2 ) n ] r -G-(CH 2 ) m —(SiX 1 X 2 X 3 ) (1)
[0000] wherein
[0039] each occurrence of Y is a polyvalent species (Q) z A(=E), preferably selected from the group consisting of
[0040] —C(═NR 1 )—; —SC(═NR 1 )—; —SC(═O)—; (—NR 1 )C(═O)—; (—NR 1 )C(═S)—; —OC(═O)—; —OC(═S)—; —C(═O)—; —SC(═S)—; —C(═S)—; —S(═O)—; —S(═O) 2 —; —OS(═O) 2 —; (—NR 1 )S(═O) 2 —; —SS(═O)—; —OS(═O)—; (—NR 1 )S(═O)—; —SS(═O) 2 —; (—S) 2 P(═O)—; -(—S)P(═O)—; —P(═O)(—) 2 ; (—S) 2 P(═S)—; -(—S)P(═S)—; —P(═S)(−) 2 ; (—NR 1 ) 2 P(═O)—; (—NR 1 )(—S)P(═O)—; (—O)(—NR 1 )P(═O)—; (—O)(—S)P(═O)—; (—O) 2 P(═O)—; -(—O)P(═O)—; -(—NR 1 )P(═O)—; (—NR 1 ) 2 P(═S)—; (—NR 1 )(—S)P(═S)—; (—O)(—NR 1 )P(═S)—; (—O)(—S)P(═S)—; (—O) 2 P(═S)—; -(—O)P(═S)—; and -(—NR 1 )P(═S)—;
[0041] wherein each atom (A) attached to the unsaturated heteroatom (E) is attached to the sulfur, which in turn is linked via a group —(CH 2 ) n G(CH 2 ) m — to the silicon atom;
[0042] each occurrence of R is chosen independently from hydrogen, straight, cyclic, or branched alkyl, alkenyl groups, aryl groups, and aralkyl groups, with each R containing from 1 to 18 carbon atoms;
[0043] each occurrence of R 1 is chosen independently from hydrogen, alkyl, alkenyl, aryl or aralkyl groups with each R 1 containing from 1 to 18 carbon atoms;
[0044] each occurrence of G is chosen independently form a group consisting of a trivalent or polyvalent hydrocarbon group of 3 to 30 carbon atoms derived by substitution of alkane, alkene or aralkane or a trivalent or polyvalent heterocarbon group of 2 to 29 carbon atoms with the proviso that G contains a cyclic structure (ring);
[0045] each occurrence of X 1 is independently selected from the set of hydrolysable groups consisting of —Cl, —Br, R 1 O—, R 1 C(═O)O—, R 1 2 C═NO—, R 1 2 NO— or R 2 N—, wherein each R 1 is as above;
[0046] each occurrence of X 2 and X 3 are independently chosen from the group consisting of the members listed for R 1 and X 1 ;
[0047] each occurrence of Q is selected independently from oxygen, sulfur, or (—NR—);
[0048] each occurrence of A is selected independently from carbon, sulfur, phosphorus, or sulfonyl;
[0049] each occurrence of E is selected independently from oxygen, sulfur, or NR 1 ;
[0050] k is 1 to 2; m=1 to 5; n=1 to 5; r is 2 to 4; z is 0 to 2; with the proviso that if A is phosphorus, then k is 2.
[0051] The term, “heterocarbon”, as used herein, refers to any hydrocarbon structure in which the carbon-carbon bonding in the backbone is interrupted by bonding to atoms of nitrogen, and/or oxygen; or in which the carbon-carbon bonding in the backbone is interrupted by bonding to groups of atoms containing nitrogen and/or oxygen, such as cyanurate (C 3 N 3 ). Heterocarbon groups also refer to any hydrocarbon in which a hydrogen or two or more hydrogens bonded to carbon are replace with a oxygen or nitrogen atom, such as a primary amine (—NH 2 ), and oxo (═O). Thus, G includes, but is not limited to branched, straight-chain hydrocarbon containing at least one ring structure, cyclic, and/or polycyclic aliphatic hydrocarbons, optionally containing ether functionality via oxygen atoms each of which is bound to two separate carbon atoms, tertiary amine functionality via nitrogen atoms each of which is bound to three separate carbon atoms, and/or cyanurate (C 3 N 3 ) groups; aromatic hydrocarbons; and arenes derived by substitution of the aforementioned aromatics with branched or straight chain alkyl, alkenyl, alkynyl, aryl and/or aralkyl groups.
[0052] As used herein, “alkyl” includes straight, branched and cyclic alkyl groups; “alkenyl” includes any straight, branched, or cyclic alkenyl group containing one or more carbon-carbon double bonds, where the point of substitution can be either at a carbon-carbon double bond or elsewhere in the group; and “alkynyl” includes any straight, branched, or cyclic alkynyl group containing one or more carbon-carbon triple bonds and optionally also one or more carbon-carbon double bonds as well, where the point of substitution can be either at a carbon-carbon triple bond, a carbon-carbon double bond, or elsewhere in the group. Specific examples of alkyls include methyl, ethyl, propyl, isobutyl. Specific examples of alkenyls include vinyl, propenyl, allyl, methallyl, ethylidenyl norbornane, ethylidene norbornyl, ethylidenyl norbornene, and ethylidene norbornenyl. Specific examples of alkynyls include acetylenyl, propargyl, and methylacetylenyl.
[0053] As used herein, “aryl” includes any aromatic hydrocarbon from which one hydrogen atom has been removed; “aralkyl” includes any of the aforementioned alkyl groups in which one or more hydrogen atoms have been substituted by the same number of like and/or different aryl (as defined herein) substituents; and “arenyl” includes any of the aforementioned aryl groups in which one or more hydrogen atoms have been substituted by the same number of like and/or different alkyl (as defined herein) substituents. Specific examples of aryls include phenyl and naphthalenyl. Specific examples of aralkyls include benzyl and phenethyl. Specific examples of arenyls include tolyl and xylyl.
[0054] As used herein, “cyclic alkyl”, “cyclic alkenyl”, and cyclic alkynyl also include bicyclic, tricyclic, and higher cyclic structures, as well as the aforementioned cyclic structures further substituted with alkyl, alkenyl, and/or alkynyl groups. Representive examples include norbornyl, norbornenyl, ethylnorbornyl, ethylnorbornenyl, ethylcyclohexyl, ethylcyclohexenyl, cyclohexylcyclohexyl, and cyclododecatrienyl.
[0055] Representative examples of the functional groups (—YS—) present in the silanes of the present invention include thiocarboxylate ester, —C(═O)S-(any silane with this functional group is a “thiocarboxylate ester silane”); dithiocarboxylate, —C(═S)S-(any silane with this functional group is a “dithiocarboxylate ester silane”); thiocarbonate ester, —OC(═O)S-(any silane with this functional group is a “thiocarbonate ester silane”); dithiocarbonate ester, —SC(═O)S— and —OC(═S)S— (any silane with this functional groups is a “dithiocarbonate ester silane”); trithiocarbonate ester, —SC(═S)S— (any silane with this functional group is a “trithiocarbonate ester silane”); dithiocarbamate ester, (—N—)C(═S)S— (any silane with this functional group is a “dithiocarbamate ester silane”); thiosulfonate ester, —S(═O) 2 S— (any silane with this functional group is a “thiosulfonate ester silane”); thiosulfate ester, —OS(═O) 2 S— (any silane with this functional group is a “thiosulfate ester silane”); thiosulfamate ester, (—N—)S(═O) 2 S— (any silane with this functional group is a “thiosulfamate ester silane”); thiosulfinate ester, —S(═O)S— (any silane with this functional group is a “thiosulfinate ester silane”); thiosulfite ester, —OS(═O)S— (any silane with this functional group is a “thiosulfite ester silane”); thiosulfimate ester, (—N—)S(═O)S— (any silane with this functional group is a “thiosulfimate ester silane”); thiophosphate ester, P(═O)(O—) 2 (S—) (any silane with this functional group is a “thiophosphate ester silane”); dithiophosphate ester, P(═O)(O—)(S—) 2 or P(═S)(O—) 2 (S—) (any silane with this functional group is a “dithiophosphate ester silane”); trithiophosphate ester, P(═O)(S—) 3 or P(═S)(O—)(S—) 2 (any silane with this functional group is a “trithiophosphate ester silane”); tetrathiophosphate ester P(═S)(S—) 3 (any silane with this functional group is a “tetrathiophosphate ester silane”); thiophosphamate ester, —P(═O)(—N—)(S—) (any silane with this functional group is a “thiophosphamate ester silane”); dithiophosphamate ester, —P(═S)(—N—)(S—) (any silane with this functional group is a “dithiophosphamate ester silane”); thiophosphoramidate ester, (—N—)P(═O)(O—)(S—) (any silane with this functional group is a “thiophosphoramidate ester silane”); dithiophosphoramidate ester, (—N—)P(═O)(S—) 2 or (—N—)P(═S)(O—)(S—) (any silane with this functional group is a “dithiophosphoramidate ester silane”); trithiophosphoramidate ester, (—N—)P(═S)(S—) 2 (any silane with this functional group is a “trithiophosphoramidate ester silane”).
[0056] Representative examples of X′ include methoxy, ethoxy, propoxy, isopropoxy, butoxy, phenoxy, benzyloxy, hydroxy, chloro, and acetoxy. Representative examples of X 2 and X 3 include the representative examples listed above for X 1 as well as methyl, ethyl, propyl, isopropyl, sec-butyl, phenyl, vinyl, cyclohexyl, and higher straight-chain alkyl, such as butyl, hexyl, octyl, lauryl, and octadecyl.
[0057] Representative examples of trisubstutitued G include any of the structures derivable from vinylnorbornene and vinylcyclohexene, such as —CH 2 CH 2 -norbornyl=, —CH(CH 3 )-norbornyl=, —CH 2 (CH—)-norbornyl-, —CH 2 CH 2 -cyclohexyl=, —CH(CH 3 )-cyclohexyl=, and —CH 2 (CH—)-cyclohexyl-; any of the structures derivable from limonene, such as —CH 2 CH(CH 3 )[(4-methyl-1-C 6 H 8 ═)CH 3 ], —C(CH 3 ) 2 [(4-methyl-1-C 6 H 8 ═)CH 3 ], and —CH 2 (C—)(CH 3 )[(4-methyl-1-C 6 H 9 —)CH 3 ], where the notation C 6 H 9 denotes isomers of the trisubstituted cyclohexane ring lacking substitution in the 2 position and where C 6 H 8 denotes the 1,4 disubstituted cyclohexene ring; any of the vinyl-containing structures derivable from trivinylcyclohexane, such as —CH 2 (CH—)(vinylC 6 H 9 )CH 2 CH 2 — and —CH 2 (CH—)(vinylC 6 H 9 )CH(CH 3 )—; any of the structures derivable from trivinylcyclohexane, such as (—CH 2 CH 2 ) 3 C 6 H 9 , (—CH 2 CH 2 ) 2 C 6 H 9 CH(CH 3 )—, —CH 2 CH 2 C 6 H 9 —[CH(CH 3 )—] 2 , and C 6 H 9 —[CH(CH 3 )—] 3 , where the notation C 6 H 9 denotes any isomer of the trisubstituted cyclohexane ring; any structure derivable by trisubstitution of cyclopentane, tetrahydrocyclopentadiene, cyclohexane, cyclodecane, cyclododecane, any of the cyclododecenes, any of the cyclododecadienes, cycloheptane, any of the cycloheptenes and any of the cycloheptadienes; trisubstituted cyanurate, piperazine, cyclohexanone, and cyclohexenone; and any structure derivable by trisubstituted benzene, toluene, xylene, mesitylene and naphthalene.
[0058] Representative examples of tetrasubstituted G include any of the structures derivable from vinylnorbornene or vinylcyclohexene, such as —CH 2 (CH—)-norbornyl= and —CH 2 (CH—)-cyclohexyl=; any of the structures derivable from limonene, such —CH 2 (C—)(CH 3 )[(4-methyl-1-C 6 He)CH 3 ], where the notation C 6 H 8 denotes the 1,4 disubstituted cyclohexene ring; any of the vinyl-containing structures derivable from trivinylcyclohexane, such as —CH 2 (CH—)(vinylC 6 H 9 )(CH—)CH 2 —, where the notation C 6 H 9 denotes any isomer of the trisubstituted cyclohexane ring; any of the structures derivable from trivinylcyclohexane, such as —CH 2 (CH—)C 6 H 9 —[CH(CH 3 )—] 2 , —CH 2 (CH—)C 6 H 9 —[CH 2 CH 2 —] 2 , and —CH 2 (CH—)C 6 H 9 —[CH(CH 3 )—][CH 2 CH 2 —], where the notation C 6 H 9 denotes any isomer of the trisubstituted cyclohexane ring; and any structure derivable by tetrasubstitution of cyclopentane, tetrahydrocyclopentadiene, cyclohexane, cyclodecane, cyclododecane, any of the cyclododecenes, any of the cyclododecadienes, cycloheptane, any of the cycloheptenes and any of the cycloheptadienes; and any structure derivable by tetrasubstitution of benzene, toluene, xylene, mesitylene and naphthalene.
[0059] Representative examples of pentasubstituted G include any of the structures derivable from trivinylcyclohexane, such as —CH 2 CH 2 C 6 H 9 —[(CH—)CH 2 —] 2 , —CH(CH 3 )C 6 H 9 —[(CH—)CH 2 —] 2 , and C 6 H 9 [(CH—)CH 2 —] 3 , where the notation C 6 H 9 denotes any isomer of the trisubstituted cyclohexane ring; and any structure derivable by pentasubstitution or hexasubstitution of cyclododecane.
[0060] Representative examples of R include hydrogen, methyl, ethyl, propyl, isopropyl, butyl, hexyl, 2-ethylhexyl, octyl, dodecyl, octadecyl, cyclohexyl, phenyl, benzyl, phenethyl, methallyl, and allyl.
[0061] In another embodiment of the present invention represented by formula (I) wherein each occurrence of Y is a polyvalent species (Q) z A(=E), each occurrence of Q is independently selected from oxygen, sulfur or NR 1 , and A is carbon and E is selected independently from oxygen, sulfur or NR 1 . Representative examples are selected from, but not limited to, the group —C(═NR)—; —SC(═NR)—; —NR′C(═NR 1 )—; —C(═O)—; —SC(═O)—; —OC(═O)—; —NR 1 )C(═O)—; and —C(═S)—; —NR 1 C(═S)—; —SC(═S)—.
[0062] In another embodiment of the present invention represented by formula (I) Y is —C(═O)—.
[0063] In another embodiment of the present invention each occurrence of m is 2-4 and n is 1-4.
[0064] In another embodiment of the present invention each occurrence of m is 2-4 and n is 2-4.
[0065] In another embodiment of the present invention each occurrence of m is 2 and n is 2.
[0066] In another embodiment of the present invention each occurrence of G is a substituted hydrocarbon containing at least one ring and from 1 to 18 carbon atoms.
[0067] In another embodiment of the present invention each occurrence of G is selected from the group consisting of substituted cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclododecane and benzene.
[0068] In another embodiment of the present invention each occurrence of the R is a straight chain alkyl group from 1 to 8 carbon atoms.
[0069] In another embodiment of the present invention each occurrence of the R is selected from the group consisting of hydrogen, methyl, ethyl and propyl.
[0070] In still another embodiment of the present invention the sum of the carbon atoms within the R groups within the molecule is from 2 to 16, more preferably 6 to 14. This amount of carbon in the R group facilitates the dispersion of the inorganic filler into the organic polymers and can affect the rate of cure, thereby improving the balance of properties in the cured filled rubber.
[0071] In another embodiment of the present invention each occurrence of G is selected from a group consisting of a trisubstituted cyclohexane or benzene, R is a straight chain alkyl group from 1 to 8 carbon atoms, r=2 and m=1 or 2, and n=1 or 2.
[0072] Representative examples of the silanes of the present invention include, but are not limited to, 1-(2-triethoxysilylethyl)-3,5-bis-(3-thia-4-oxopentyl)benzene, 1-(2-triethoxysilylethyl)-3,5-bis-(3-thia-4-oxohexyl)benzene, 1-(2-triethoxysilylethyl)-3,5-bis-(3-thia-4-oxoheptyl)benzene, 1-(2-tripropoxysilylmethyl)-3,5-bis-(3-thia-4-oxopentyl)benzene, 4-(2-triethoxysilylethyl)-1,2-bis-(2-thia-3-oxopentyl)benzene, 1-(2-diethoxymethylsilylethyl)-3,5-bis-(3-thia-4-oxopentyl)benzene, 4-(2-dimethylethoxysilylethyl)-1,2-bis-(3-thia-4-oxopentyl)benzene, 4-(2-triethoxysilylethyl)-1,2-bis-(2-thia-3-oxopentypcyclohexane, 1-(2-triethoxysilylethyl)-2,4-bis-(2-thia-3-oxopentypcyclohexane, 2-(2-triethoxysilylethyl)-1,4-bis-(2-thia-3-oxopentypcyclohexane, 4-(2-diethoxymethylsilylethyl)-1,2-bis-(3-thia-4-oxopentypcyclohexane, 4-(2-dimethylethoxysilylethyl)-1,2-bis-(3-thia-4-oxopentypcyclohexane, 4-(2-triethoxysilylethyl)-1,2-bis-(3-thia-4-oxohexypcyclohexane, 1-(2-triethoxysilylethyl)-2,4-bis-(3-thia-4-oxohexyl)cyclohexane, 2-(2-triethoxysilylethyl)-1,4-bis-(3-thia-4-oxohexyl)cyclohexane, 4-(2-triethoxysilylethyl)-1,2-bis-(3-thia-4-oxononyl)cyclohexane, 1-(2-triethoxysilylethyl)-2,4-bis-(3-thia-4-oxononypcyclohexane, 2-(2-triethoxysilylethyl)-1,4-bis-(3-thia-4-oxononyl)cyclohexane, 4-(2-triethoxysilylethyl)-1,2-bis-(3-thia-4-oxoundecyl)cyclohexane, 1-(2-triethoxysilylethyl)-2,4-bis-(3-thia-4-oxoundecypcyclohexane, 2-(2-triethoxysilylethyl)-1,4-bis-(3-thia-4-oxoundecyl)cyclohexane, 4-(2-dimethylethoxysilylethyl)-1,2-bis-(3-thia-4-oxododecyl)cyclohexane, 4-(2-triethoxysilylethyl)-1,2-bis-(3-thia-4-oxododecyl)cyclohexane, 4-(2-triethoxysilylethyl)-1,2-bis-(3-thia-4-oxo-5-aza-5-methyldodecypcyclohexane, (2-triethoxysilylethyl)-1,2-bis-(3,5-dithia-4-oxododecyl)cyclohexane, 1-(2-triethoxysilylethyl)-3,5-bis-(3-thia-4-oxopenyl)mesitylene and 6-(2-triethoxysilylpropyl)-2,2-bis-(3-thia-4-oxopentyl)cyclohexanone, and mixtures thereof.
[0073] In another embodiment mixtures of various blocked mercaptosilanes may be used, including wherein synthetic methods result in a distribution of various silanes or where mixes of blocked mercaptosilanes are used for their various blocking or leaving functionalities. Moreover, it is understood that the partial hydrolyzates of these blocked mercaptosilanes (i.e., blocked mercaptosiloxanes) may also be encompassed by the blocked mercaptosilanes herein, in that these partial hydrolyzates will be a side product of most methods of manufacture of the blocked mercaptosilane or can occur upon storage of the blocked mercaptosilane, especially in humid conditions.
[0074] In still another embodiment the silane, if liquid, may be loaded on a carrier, such as a porous polymer, carbon black, siliceous filler, or silica so that it is in solid form for delivery to the rubber. The silane can react with the surface groups of the siliceous filler or silica, especially if the silane and filler mixture is heated to about 50 to 150 degrees C. at atmospheric or reduced pressures.
Manufacture of Silanes
[0075] An embodiment of the present invention includes methods for the preparation of blocked mercaptosilanes which can involve direct incorporation of the thioester group into a silane by addition of the thioacid across a carbon-carbon double bond. The reaction is the free radical addition of a thioacid across a carbon-carbon double bond of an alkene-functional silane, catalyzed by UV light, heat, or the appropriate free radical initiator wherein, if the thioacid is a thiocarboxylic acid, the two reagents are brought into contact with each other in such a way as to ensure that whichever reagent is added to the other is reacted substantially before the addition proceeds. The reaction can be carried out by heating or refluxing a mixture of the alkene-functional silane and the thioacid. Aspects have been disclosed previously in U.S. Pat. No. 3,692,812 and by G. A. Gornowicz et al., in J. Org. Chem. (1968), 33(7), 2918-24. The uncatalyzed reaction can occur at temperatures as low as 105° C., but often fails. The probability of success increases with temperature and becomes high when the temperature exceeds 160° C. The reaction may be made reliable and the reaction brought largely to completion by using UV radiation or a catalyst. With a catalyst, the reaction can be made to occur at temperatures below 90° C. Appropriate catalysts are free radical initiators, e.g., air, peroxides, preferably organic peroxides, and azo compounds. Examples of peroxide initiators include peracids, such as perbenzoic and peracetic acids; esters of peracids; hydroperoxides, such as t-butyl hydroperoxide; peroxides, such as di-t-butyl peroxide; and peroxy-acetals and ketals, such as 1,1-bis(t-butylperoxy)cyclohexane, or any other peroxide. Examples of azo initiators include azobisisobutyronitrile (AIBN), 1,1-azobis(cyclohexanecarbonitrile) (VAZO, DuPont product); and azo-tert-butane. The reaction can be run by heating a mixture of the alkene-functional silane and the thioacid with the catalyst. It is preferable for the overall reaction to be run on an equimolar or near equimolar basis to get the highest conversions. The reaction is sufficiently exothermic that it tends to lead to a rapid temperature increase to reflux followed by a vigorous reflux as the reaction initiates and continues rapidly. This vigorous reaction can lead to hazardous boil-overs for larger quantities. Side reactions, contamination, and loss in yield can result as well from uncontrolled reactions. The reaction can be controlled effectively by adding partial quantities of one reagent to the reaction mixture, initiating the reaction with the catalyst, allowing the reaction to run its course largely to completion, and then adding the remains of the reagent, either as a single addition or as multiple additives. The initial concentrations and rate of addition and number of subsequent additions of the deficient reagent depend on the type and amount of catalyst used, the scale of the reaction, the nature of the starting materials, and the ability of the apparatus to absorb and dissipate heat. A second way of controlling the reaction would involve the continuous addition of one reagent to the other with concomitant continuous addition of catalyst. Whether continuous or sequential addition is used, the catalyst can be added alone and/or preblended with one or both reagents or combinations thereof. Two methods are preferred for reactions involving thioacid, such as thiocarboxylic acid, and alkene-functional silanes containing terminal carbon-carbon double bonds. The first involves initially bringing the alkene-functional silane to a temperature of 160° to 180° C., or to reflux, whichever temperature is lower. The first portion of thioacid is added at a rate as to maintain up to a vigorous, but controlled, reflux. For alkene-functional silanes with boiling points above 100° to 120° C., this reflux results largely from the relatively low boiling point of thioacid (88° to 92° C., depending on purity) relative to the temperature of the alkene-functional silane. At the completion of the addition, the reflux rate rapidly subsides. It often accelerates again within several minutes, especially if an alkene-functional silane with a boiling point above 120° C. is used, as the reaction initiates. If it does not initiate within 10 to 15 minutes, initiation can be brought about by addition of catalyst. The preferred catalyst is di-t-butyl peroxide. The appropriate quantity of catalyst is from 0.2 to 2 percent, preferably from 0.5 to 1 percent, of the total mass of mixture to which the catalyst is added. The reaction typically initiates within a few minutes as evidenced by an increase in reflux rate. The reflux temperature gradually increases as the reaction proceeds. Then the next portion of thioacid is added, and the aforementioned sequence of steps is repeated. The preferred number of thioacid additions for total reaction quantities of about one to about four kilograms is two, with about one-third of the total thioacid used in the first addition and the remainder in the second. For total quantities in the range of about four to ten kilograms, a total of three thioacid additions is preferred, the distribution being approximately 20 percent of the total used in the first addition, approximately 30 percent in the second addition, and the remainder in the third addition. For larger scales involving thioacid and alkene-functional silanes, it is preferable to use more than a total of three thioacid additions and, more preferably, to add the reagents in the reverse order. Initially, the total quantity of thioacid is brought to reflux. This is followed by continuous addition of the alkene-functional silane to the thioacid at such a rate as to bring about a smooth but vigorous reaction rate. The catalyst, preferably di-t-butylperoxide, can be added in small portions during the course of the reaction or as a continuous flow. It is best to accelerate the rate of catalyst addition as the reaction proceeds to completion to obtain the highest yields of product for the lowest amount of catalyst required. The total quantity of catalyst used should be 0.5 to 2 percent of the total mass of reagents used. Whichever method is used, the reaction is followed up by a vacuum stripping process to remove volatiles and unreacted thioacid and silane. The product may be purified by distillation.
[0076] In another embodiment of the present invention the reaction is between an alkali metal salt of a thioacid with a haloalkylsilane. The first step involves preparation of a salt of the thioacid. Alkali metal derivatives are preferred, with the sodium derivative being most preferred. These salts would be prepared as solutions in solvents in which the salt is appreciably soluble, but suspensions of the salts as solids in solvents in which the salts are only slightly soluble are also a viable option. Alcohols, such as propanol, isopropanol, butanol, isobutanol, and t-butanol, and preferably methanol and ethanol are useful because the alkali metal salts are slightly soluble in them. In cases where the desired product is an alkoxysilane, it is preferable to use an alcohol corresponding to the silane alkoxy group to prevent transesterification at the silicon ester. Alternatively, nonprotic solvents can be used. Examples of appropriate solvents are ethers or polyethers such as glyme, diglyme, and dioxanes; N,N-dimethylformamide; N,N-dimethylacetamide; dimethylsulfoxide; N-methylpyrrolidinone; or hexamethylphosphoramide. Once a solution, suspension, or combination thereof of the salt of the thioacid has been prepared, the second step is to react it with the appropriate haloalkylsilane. This may be accomplished by stirring a mixture of the haloalkylsilane with the solution, suspension, or combination thereof of the salt of the thioacid at temperatures corresponding to the liquid range of the solvent for a period of time sufficient to complete substantially the reaction. Preferable temperatures are those at which the salt is appreciably soluble in the solvent and at which the reaction proceeds at an acceptable rate without excessive side reactions. With reactions starting from chloroalkylsilanes in which the chlorine atom is not allylic or benzylic, preferable temperatures are in the range of 60° to 160° C. Reaction times can range from one or several hours to several days. For alcohol solvents where the alcohol contains four carbon atoms or fewer, the most preferred temperature is at or near reflux. When diglyme is used as a solvent, the most preferred temperature is in the range of 70° to 120° C., depending on the thioacid salt used. If the haloalkylsilane is a bromoalkylsilane or a chloroalkylsilane in which the chlorine atom is allylic or benzylic, temperature reductions of 30° to 60° C. are appropriate relative to those appropriate for nonbenzylic or nonallylic chloroalkylsilanes because of the greater reactivity of the bromo group. Bromoalkylsilanes are preferred over chloroalkylsilanes because of their greater reactivity, lower temperatures required, and greater ease in filtration or centrifugation of the coproduct alkali metal halide. This preference, however, can be overridden by the lower cost of the chloroalkylsilanes, especially for those containing the halogen in the allylic or benzylic position. For reactions between straight chain chloroalkylethoxysilanes and sodium thiocarboxylates to form thiocarboxylate ester ethoxysilanes, it is preferable to use ethanol at reflux for 10 to 20 hours if 5 to 20 percent mercaptosilane is acceptable in the product. Otherwise, diglyme would be an excellent choice, in which the reaction would be run preferably in the range of 80° to 120° C. for one to three hours. Upon completion of the reaction the salts and solvent should be removed, and the product may be distilled to achieve higher purity.
[0077] If the salt of the thioacid to be used is not commercially available, its preparation may be accomplished by one of two methods, described below as Method A and Method B. Method A involves adding the alkali metal or a base derived from the alkali metal to the thioacid. The reaction occurs at ambient temperature. Appropriate bases include alkali metal alkoxides, hydrides, carbonates, and bicarbonates. Solvents, such as toluene, xylene, benzene, aliphatic hydrocarbons, ethers, and alcohols may be used to prepare the alkali metal derivatives. In Method B, acid chlorides or acid anhydrides would be converted directly to the salt of the thioacid by reaction with the alkali metal sulfide or hydrosulfide. Hydrated or partially hydrous alkali metal sulfides or hydrosulfides are available; however, anhydrous or nearly anhydrous alkali metal sulfides or hydrosulfides are preferred. Hydrous materials can be used, however, but with loss in yield and hydrogen sulfide formation as a coproduct. The reaction involves addition of the acid chloride or acid anhydride to the solution or suspension of the alkali metal sulfide and/or hydrosulfide and heating at temperatures ranging from ambient to the reflux temperature of the solvent for a period of time sufficient largely to complete the reaction, as evidenced by the formation of the coproduct salts.
[0078] If the alkali metal salt of the thioacid is prepared in such a way that an alcohol is present, either because it was used as a solvent, or because it formed, as for example, by the reaction of a thioacid with an alkali metal alkoxide, it may be desirable to remove the alcohol if a product low in mercaptosilane is desired. In this case, it would be necessary to remove the alcohol prior to reaction of the salt of the thioacid with the haloalkylsilane. This could be done by distillation or evaporation. Alcohols, such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, and t-butanol are preferably removed by azeotropic distillation with benzene, toluene, xylene, or aliphatic hydrocarbons. Toluene and xylene are preferred.
Utility
[0079] The blocked mercaptosilanes described herein are useful as coupling agents for organic polymers (i.e., rubbers) and inorganic fillers. The blocked mercaptosilanes are unique in that the high efficiency of the mercapto group can be utilized without the detrimental side effects typically associated with the use of mercaptosilanes, such as high processing viscosity, less than desirable filler dispersion, premature curing (scorch), and odor. These benefits are accomplished because the mercaptan group initially is nonreactive because of the blocking group. The blocking group substantially prevents the silane from coupling to the organic polymer during the compounding of the rubber. Generally, only the reaction of the silane —SiX 1 X 2 X 3 group with the filler can occur at this stage of the compounding process. Thus, substantial coupling of the filler to the polymer is precluded during mixing, thereby minimizing the undesirable premature curing (scorch) and the associated undesirable increase in viscosity. One can achieve better cured filled rubber properties, such as a balance of high modulus and abrasion resistance, because of the avoidance of premature curing.
[0080] The number of methylene groups between the silicon and G group, denoted by m, and sulfur (blocked mercaptan) and G group, denoted by n, improves coupling because the methylene group mitigates excessive steric interactions between the silane and the filler and polymer. Two successive methylene groups mitigate steric interactions even further and also add flexibility to the chemical structure of the silane, thereby enhancing its ability to accommodate the positional and orientational constraints imposed by the morphologies of the surfaces of both the rubber and filler at the interphase, at the molecular level. The silane flexibility becomes increasingly important as the total number of silicon and sulfur atoms bound to G increases from 3 to 4 and beyond. Tighter structures containing secondary and especially, tertiary carbon atoms; ring structures; and especially, aromatic structures on G near silicon and/or sulfur, are more rigid and cannot readily orient to meet available binding sites on silica and polymer. This would tend to leave sulfur groups unbound to polymer, thereby reducing the efficiency by which the principle of multiple bonding of silane to polymer via multiple bocked mercapto groups on silane, is realized.
[0081] The G group from which silicon and blocked mercapto group emanate through one or more methylene groups from a cyclic structure also improves coupling because the geometry of the cyclic structure naturally directs the emanating groups away from each other. This keeps them from getting in each other's way and also forces them to orient in divergent directions, so that silicon can bond to the filler, while sulfur bonds to the polymer phase. Aromatic cyclic structures for G are very rigid. Thus, although they direct silicon and blocked mercapto group in diverging directions, their rigidity limits freedom of orientation. The aliphatic cyclic G structures, because they do not contain the conjugated double bonds, are more flexible. They combine the advantages of divergent silicon and sulfur orientations from a cyclic structure and flexibility of the aliphatic cyclic structure.
[0082] One embodiment of the present invention is a rubber composition comprising:
a) a blocked mercaptosilane of formula I; b) an organic polymer; c) a filler; and optionally, d) other additives and curatives.
[0087] Another embodiment involves the use of these blocked mercaptosilanes of the present invention. One or more of the blocked mercaptosilanes are mixed with the organic polymer before, during, or after the compounding of the filler into the organic polymer. In a preferred embodiment the silanes are added before or during the compounding of the filler into the organic polymer, because these silanes facilitate and improve the dispersion of the filler. The total amount of silane present in the resulting combination should be about 0.05 to about 25 parts by weight per hundred parts by weight of organic polymer (phr), more preferably 1 to 10 phr. Fillers can be used in quantities ranging from about 5 to 100 phr, more preferably from 25 to 80 phr.
[0088] When reaction of the mixture to couple the filler to the polymer is desired, a deblocking agent is added to the mixture to deblock the blocked mercaptosilane. The deblocking agent may be added at quantities ranging from about 0.1 to about 5 phr, more preferably in the range of from 0.5 to 3 phr. If alcohol or water is present (as is common) in the mixture, a catalyst (e.g., tertiary amines, Lewis acids, or thiols) may be used to initiate and promote the loss of the blocking group by hydrolysis or alcoholysis to liberate the corresponding mercaptosilane. Alternatively, the deblocking agent may be a nucleophile containing a hydrogen atom sufficiently labile such that the hydrogen atom could be transferred to the site of the original blocking group to form the mercaptosilane. Thus, with a blocking group acceptor molecule, an exchange of hydrogen from the nucleophile would occur with the blocking group of the blocked mercaptosilane to form the mercaptosilane and the corresponding derivative of the nucleophile containing the original blocking group. This transfer of the blocking group from the silane to the nucleophile could be driven, for example, by a greater thermodynamic stability of the products (mercaptosilane and nucleophile containing the blocking group) relative to the initial reactants (blocked mercaptosilane and nucleophile). For example, if the nucleophile were an amine containing an N—H bond, transfer of the blocking group from the blocked mercaptosilane would yield the mercaptosilane and one of several classes of amides corresponding to the type of blocking group used. For example, carboxyl blocking groups deblocked by amines would yield amides, sulfonyl blocking groups deblocked by amines would yield sulfonamides, sulfinyl blocking groups deblocked by amines would yield sulfinamides, phosphonyl blocking groups deblocked by amines would yield phosphonamides, phosphinyl blocking groups deblocked by amines would yield phosphinamides. What is important is that regardless of the blocking group initially present on the blocked mercaptosilane and regardless of the deblocking agent used, the initially substantially inactive (from the standpoint of coupling to the organic polymer) blocked mercaptosilane is substantially converted at the desired point in the rubber compounding procedure to the active mercaptosilane. It is noted that partial amounts of the nucleophile may be used (i.e., a stoichiometric deficiency), if one were to deblock only part of the blocked mercaptosilane to control the degree of vulcanization of a specific formulation.
[0089] Water typically is present on the inorganic filler as a hydrate, or bound to a filler in the form of a hydroxyl group. The deblocking agent could be added in the curative package or, alternatively, at any other stage in the compounding process as a single component. Examples of nucleophiles would include any primary or secondary amines, or amines containing C═N double bonds, such as imines or guanidines, with the proviso that said amine contains at least one N—H (nitrogen-hydrogen) bond. Numerous specific examples of guanidines, amines, and imines well known in the art, which are useful as components in curatives for rubber, are cited in J. Van Alphen, Rubber Chemicals , (Plastics and Rubber Research Institute TNO, Delft, Holland, 1973). Some examples include N,N′-diphenylguanidine, N,N′,N″-triphenylguanidine, N,N′-di-ortho-tolylguanidine, orthobiguanide, hexamethylenetetramine, cyclohexylethylamine, dibutylamine, and 4,4′-diaminodiphenylmethane. Any general acid catalysts used to transesterify esters, such as Bronsted or Lewis acids, could be used as catalysts.
[0090] The rubber composition need not be, but preferably is, essentially free of functionalized siloxanes, especially those of the type disclosed in Australian Patent AU-A-10082/97, which is incorporated herein by reference. Most preferably, the rubber composition is free of functionalized siloxanes.
[0091] In practice, sulfur vulcanized rubber products typically are prepared by thermomechanically mixing rubber and various ingredients in a sequentially stepwise manner followed by shaping and curing the compounded rubber to form a vulcanized product. First, for the aforesaid mixing of the rubber and various ingredients, typically exclusive of sulfur and sulfur vulcanization accelerators (collectively “curing agents”), the rubber(s) and various rubber compounding ingredients typically are blended in at least one, and often (in the case of silica filled low rolling resistance tires) two, preparatory thermomechanical mixing stage(s) in suitable mixers. Such preparatory mixing is referred to as nonproductive mixing or nonproductive mixing steps or stages. Such preparatory mixing usually is conducted at temperatures up to 140° to 200° C. and often up to 150° to 180° C. Subsequent to such preparatory mix stages, in a final mixing stage, sometimes referred to as a productive mix stage, deblocking agent (in the case of this invention), curing agents, and possibly one or more additional ingredients are mixed with the rubber compound or composition, typically at a temperature in a range of 50° to 130° C., which is a lower temperature than the temperatures utilized in the preparatory mix stages to prevent or retard premature curing of the sulfur curable rubber, which is sometimes referred to as scorching of the rubber composition. The rubber mixture, sometimes referred to as a rubber compound or composition, typically is allowed to cool, sometimes after or during a process intermediate mill mixing, between the aforesaid various mixing steps, for example, to a temperature of about 50° C. or lower. When it is desired to mold and to cure the rubber, the rubber is placed into the appropriate mold at about at least 130° C. and up to about 200° C., which will cause the vulcanization of the rubber by the mercapto groups on the mercaptosilane and any other free sulfur sources in the rubber mixture.
[0092] By thermomechanical mixing, it is meant that the rubber compound, or composition of rubber and rubber compounding ingredients, is mixed in a rubber mixture under high shear conditions where it autogenously heats up as a result of the mixing primarily due to shear and associated friction within the rubber mixture in the rubber mixer. Several chemical reactions may occur at various steps in the mixing and curing processes.
[0093] The first reaction is a relatively fast reaction and is considered herein to take place between the filler and the SiX 3 group of the blocked mercaptosilane. Such reaction may occur at a relatively low temperature such as, for example, at about 120° C. The second and third reactions are considered herein to be the deblocking of the mercaptosilane and the reaction which takes place between the sulfuric part of the organosilane (after deblocking), and the sulfur vulcanizable rubber at a higher temperature, for example, above about 140° C.
[0094] Another sulfur source may be used, for example, in the form of elemental sulfur as S 8 . A sulfur donor is considered herein as a sulfur containing compound which liberates free, or elemental, sulfur at a temperature in a range of 140° to 190° C. Examples of such sulfur donors may be, but are not limited to, polysulfide vulcanization accelerators and organosilane polysulfides with at least two connecting sulfur atoms in its polysulfide bridge. The amount of free sulfur source addition to the mixture can be controlled or manipulated as a matter of choice relatively independently from the addition of the aforesaid blocked mercaptosilane. Thus, for example, the independent addition of a sulfur source may be manipulated by the amount of addition thereof and by sequence of addition relative to addition of other ingredients to the rubber mixture.
[0095] Addition of an alkyl silane to the coupling agent system (blocked mercaptosilane plus additional free sulfur source and/or vulcanization accelerator) typically in a mole ratio of alkyl silane to blocked mercaptosilane in a range of 1/50 to ½ promotes an even better control of rubber composition processing and aging.
[0096] In an embodiment of the present invention, a rubber composition is prepared by a process which comprises the sequential steps of:
[0097] (A) thermomechanically mixing, in at least one preparatory mixing step, to a temperature of 140° to 200° C., alternatively to 140° to 190° C., for a total mixing time of 2 to 20 minutes, alternatively 4 to 15 minutes, for such mixing step(s);
[0098] (i) 100 parts by weight of at least one sulfur vulcanizable rubber selected from conjugated diene homopolymers and copolymers, and copolymers of at least one conjugated diene and aromatic vinyl compound,
[0099] (ii) 5 to 100 phr (parts per hundred rubber), preferably 25 to 80 phr, of particulate filler, wherein preferably the filler contains 1 to 85 weight percent carbon black,
[0100] (iii) 0.05 to 20 parts by weight filler of at least one blocked mercaptosilane;
[0101] (B) subsequently blending therewith, in a final thermomechanical mixing step at a temperature to 50° to 130° C. for a time sufficient to blend the rubber, preferably between 1 to 30 minutes, more preferably 1 to 3 minutes, at least one deblocking agent at about 0.05 to 20 parts by weight of the filler and a curing agent at 0 to 5 phr; and optionally
[0102] (C) curing said mixture at a temperature of 130° to 200° C. for about 5 to 60 minutes.
[0103] In another embodiment of the present invention, the process may also comprise the additional steps of preparing an assembly of a tire or sulfur vulcanizable rubber with a tread comprised of the rubber composition prepared according to this invention and vulcanizing the assembly at a temperature in a range of 130° to 200° C.
[0104] Suitable organic polymers and fillers are well known in the art and are described in numerous texts, of which two examples include The Vanderbilt Rubber Handbook , R. F. Ohm, ed. (R.T. Vanderbilt Company, Inc., Norwalk, Conn., 1990), and Manual for the Rubber Industry , T. Kempermann, S. Koch, and J. Sumner, eds. (Bayer AG, Leverkusen, Germany, 1993). Representative examples of suitable polymers include solution styrene-butadiene rubber (sSBR), styrene-butadiene rubber (SBR), natural rubber (NR), polybutadiene (BR), ethylene-propylene co- and ter-polymers (EP, EPDM), and acrylonitrile-butadiene rubber (NBR). The rubber composition is comprised of at least one diene-based elastomer, or rubber. Suitable conjugated dienes are isoprene and 1,3-butadiene and suitable vinyl aromatic compounds are styrene and alpha methyl styrene. Thus, the rubber is a sulfur curable rubber. Such diene based elastomer, or rubber, may be selected, for example, from at least one of cis-1,4-polyisoprene rubber (natural and/or synthetic, and preferably natural rubber), emulsion polymerization prepared styrene/butadiene copolymer rubber, organic solution polymerization prepared styrene/butadiene rubber, 3,4-polyisoprene rubber, isoprene/butadiene rubber, styrene/isoprene/butadiene terpolymer rubber, cis-1,4-polybutadiene, medium vinyl polybutadiene rubber (35 percent to 50 percent vinyl), high vinyl polybutadiene rubber (50 percent to 75 percent vinyl), styrene/isoprene copolymers, emulsion polymerization prepared styrene/butadiene/acrylonitrile terpolymer rubber and butadiene/acrylonitrile copolymer rubber. An emulsion polymerization derived styrene/butadiene (eSBR) might be used having a relatively conventional styrene content of 20 percent to 28 percent bound styrene or, for some applications, an eSBR having a medium to relatively high bound styrene content, namely, a bound styrene content of 30 percent to 45 percent. Emulsion polymerization prepared styrene/butadiene/acrylonitrile terpolymer rubbers containing 2 to 40 weight percent bound acrylonitrile in the terpolymer are also contemplated as diene based rubbers for use in this invention.
[0105] The solution polymerization prepared SBR (sSBR) typically has a bound styrene content in a range of 5 to 50 percent, preferably 9 to 36 percent. Polybutadiene elastomer may be conveniently characterized, for example, by having at least a 90 weight percent cis-1,4-content.
[0106] Representative examples of suitable filler materials include metal oxides, such as silica (pyrogenic and precipitated), titanium dioxide, aluminosilicate and alumina, siliceous materials including clays and talc, and carbon black. Particulate, precipitated silica is also sometimes used for such purpose, particularly when the silica is used in connection with a silane. In some cases, a combination of silica and carbon black is utilized for reinforcing fillers for various rubber products, including treads for tires. Alumina can be used either alone or in combination with silica. The term “alumina” can be described herein as aluminum oxide, or Al 2 O 3 . The fillers may be hydrated or in anhydrous form. Use of alumina in rubber compositions can be shown, for example, in U.S. Pat. No. 5,116,886 and EP 631,982.
[0107] In another embodiment of the present invention, the blocked mercaptosilane may be premixed, or prereacted, with the filler particles or added to the rubber mix during the rubber and filler processing, or mixing stage. If the silane and filler are added separately to the rubber mix during the rubber and filler mixing, or processing stage, it is considered that the blocked mercaptosilane then combines in situ with the filler.
[0108] The vulcanized rubber composition should contain a sufficient amount of filler to contribute a reasonably high modulus and high resistance to tear. The combined weight of the filler may be as low as about 5 to 100 phr, but is more preferably from 25 phr to 85 phr.
[0109] In another embodiment of the present invention, precipitated silicas are used as the filler. The silica may be characterized by having a BET surface area, as measured using nitrogen gas, preferably in the range of 40 to 600 m 2 /g, and more usually in a range of 50 to 300 m 2 /g. The silica typically may also be characterized by having a dibutylphthalate (DBP) absorption value in a range of 100 to 350, and more usually 150 to 300. Further, the silica, as well as the aforesaid alumina and aluminosilicate, may be expected to have a CTAB surface area in a range of 100 to 220. The CTAB surface area is the external surface area as evaluated by cetyl trimethylammonium bromide with a pH of 9. The method is described in ASTM D 3849.
[0110] Mercury porosity surface area is the specific surface area determined by mercury porosimetry. For such technique, mercury is penetrated into the pores of the sample after a thermal treatment to remove volatiles. Set up conditions may be suitably described as using a 100 mg sample, removing volatiles during two hours at 105° C. and ambient atmospheric pressure, ambient to 2000 bars pressure measuring range. Such evaluation may be performed according to the method described in Winslow, Shapiro in ASTM bulletin, page 39 (1959) or according to DIN 66133. For such an evaluation, a CARLO-ERBA Porosimeter 2000 might be used. The average mercury porosity specific surface area for the silica should be in a range of 100 to 300 m 2 /g.
[0111] A suitable pore size distribution for the silica, alumina, and aluminosilicate according to such mercury porosity evaluation is considered herein to be: 5 percent or less of its pores have a diameter of less than about 10 nm; 60 percent to 90 percent of its pores have a diameter of 10 to 100 nm; 10 percent to 30 percent of its pores have a diameter of 100 to 1,000 nm; and 5 percent to 20 percent of its pores have a diameter of greater than about 1,000 nm.
[0112] The silica might be expected to have an average ultimate particle size, for example, in the range of 0.01 to 0.05 μm as determined by the electron microscope, although the silica particles may be even smaller, or possibly larger, in size. Various commercially available silicas may be considered for use in this invention such as, from PPG Industries under the HI-SIL trademark with designations HI-SIL 210, 243, etc.; silicas available from Rhone-Poulenc, with, for example, designation of ZEOSIL 1165 MP; silicas available from Degussa with, for example, designations VN2 and VN3, etc.; and silicas commercially available from Huber having, for example, a designation of HUBERSIL 8745.
[0113] In another embodiment of the present invention, where it is desired for the rubber composition, which contains both a siliceous filler such as silica, alumina and/or aluminosilicates and also carbon black reinforcing pigments, to be primarily reinforced with silica as the reinforcing pigment, it is often preferable that the weight ratio of such siliceous fillers to carbon black is at least 3/1 and preferably at least 10/1 and, thus, in a range of 3/1 to 30/1. The filler may be comprised of 15 to 95 weight percent precipitated silica, alumina, and/or aluminosilicate and, correspondingly 5 to 85 weight percent carbon black, wherein the carbon black has a CTAB value in a range of 80 to 150. Alternatively, the filler can be comprised of 60 to 95 weight percent of said silica, alumina, and/or aluminosilicate and, correspondingly, 40 to 5 weight percent carbon black. The siliceous filler and carbon black may be preblended or blended together in the manufacture of the vulcanized rubber.
[0114] The rubber composition may be compounded by methods known in the rubber compounding art, such as mixing the various sulfur-vulcanizable constituent rubbers with various commonly used additive materials. Examples of such commonly used additive materials include curing aids, such as sulfur, activators, retarders and accelerators, processing additives, such as oils, resins including tacicifying resins, silicas, plasticizers, fillers, pigments, fatty acid, zinc oxide, waxes, antioxidants and antiozonants, peptizing agents, and reinforcing materials, such as, for example, carbon black. Depending on the intended use of the sulfur vulcanizable and sulfur vulcanized material (rubbers), the additives mentioned above are selected and commonly used in conventional amounts.
[0115] The vulcanization may be conducted in the presence of an additional sulfur vulcanizing agent. Examples of suitable sulfur vulcanizing agents include, for example, elemental sulfur (free sulfur) or sulfur donating vulcanizing agents, for example, an amino disulfide, polymeric polysulfide, or sulfur olefin adducts which are conventionally added in the final, productive, rubber composition mixing step. The sulfur vulcanizing agents (which are common in the art) are used, or added in the productive mixing stage, in an amount ranging from 0.4 to 3 phr, or even, in some circumstances, up to about 8 phr, with a range of from 1.5 to 2.5 phr, sometimes from 2 to 2.5 phr, being preferred.
[0116] Vulcanization accelerators, i.e., additional sulfur donors, may be used herein. It is appreciated that they may be, for example, of the type such as, for example, benzothiazole, alkyl thiuram disulfide, guanidine derivatives, and thiocarbamates. Representative of such accelerators are, for example, but are not limited to, mercapto benzothiazole, tetramethyl thiuram disulfide, benzothiazole disulfide, diphenylguanidine, zinc dithiocarbamate, alkylphenoldisulfide, zinc butyl xanthate, N-dicyclohexyl-2-benzothiazolesulfenamide, N-cyclohexyl-2-benzothiazolesulfenamide, N-oxydiethylenebenzothiazole-2-sulfenamide, N,N-diphenylthiourea, dithiocarbamylsulfenamide, N,N-diisopropylbenzothiozole-2-sulfenamide, zinc-2-mercaptotoluimidazole, dithiobis(N-methyl piperazine), dithiobis(N-beta-hydroxy ethyl piperazine) and dithiobis(dibenzyl amine). Other additional sulfur donors, may be, for example, thiuram and morpholine derivatives. Representative of such donors are, for example, but not limited to, dimorpholine disulfide, dimorpholine tetrasulfide, tetramethyl thiuram tetrasulfide, benzothiazyl-2,N-dithiomorpholide, thioplasts, dipentamethylenethiuram hexasulfide, and disulfidecaprolactam.
[0117] Accelerators are used to control the time and/or temperature required for vulcanization and to improve the properties of the vulcanizate. In one embodiment, a single accelerator system may be used, i.e., a primary accelerator. Conventionally and preferably, a primary accelerator(s) is used in total amounts ranging from 0.5 to 4 phr, preferably 0.8 to 1.5 phr. Combinations of a primary and a secondary accelerator might be used with the secondary accelerator being used in smaller amounts (of 0.05 to 3 phr) in order to activate and to improve the properties of the vulcanizate. Delayed action accelerators may be used. Vulcanization retarders might also be used. Suitable types of accelerators are amines, disulfides, guanidines, thioureas, thiazoles, thiurams, sulfenamides, dithiocarbamates, and xanthates. Preferably, the primary accelerator is a sulfenamide. If a second accelerator is used, the secondary accelerator is preferably a guanidine, dithiocarbamate, or thiuram compound.
[0118] Typical amounts of tackifier resins, if used, comprise 0.5 to 10 phr, usually 1 to 5 phr. Typical amounts of processing aids comprise 1 to 50 phr. Such processing aids include, for example, aromatic, naphthenic, and/or paraffinic processing oils. Typical amounts of antioxidants comprise 1 to 5 phr. Representative antioxidants may be, for example, diphenyl-p-phenylenediamine and others such as those disclosed in the Vanderbilt Rubber Handbook (1978), pages 344-46. Typical amounts of antiozonants comprise 1 to 5 phr. Typical amounts of fatty acids, which, if used, can include stearic acid, comprise 0.5 to 3 phr. Typical amounts of zinc oxide comprise 2 to 5 phr. Typical amounts of waxes comprise 1 to 5 phr. Often microcrystalline waxes are used. Typical amounts of peptizers comprise 0.1 to 1 phr. Typical peptizers may be, for example, pentachlorothiophenol and dibenzamidodiphenyl disulfide.
[0119] In still another embodiment of the present invention, the rubber composition of this invention can be used for various purposes. For example, it can be used for various tire compounds. Such tires can be built, shaped, molded, and cured by various methods which are known and will be readily apparent to those having skill in such art.
[0120] All references cited are incorporated herein as they are relevant to the present invention.
[0121] The invention may be better understood by reference to the following examples in which the parts and percentages are by weight unless otherwise indicated.
COMPARATIVE EXAMPLE A
Preparation of 3-(octanoylthio)-1-propyltriethoxysilane
[0122] Into a 12-liter, three-necked round bottom flask equipped with mechanical stirrer, addition funnel, thermocouple, heating mantle, N 2 inlet, and temperature controller were charged 3-mercaptopropyltriethoxysilane (1,021 grams, 3.73 moles purchase as SILQUEST® A-1891 silane from General Electric Company), triethylamine (433 grams), and hexane (3,000 ml). The solution was cooled in an ice bath, and octanoyl chloride (693 grams, 4.25 moles) were added over a two hour period via the addition funnel. After addition of the acid chloride was complete, the mixture was filtered two times, first through a 0.1 μm filter and then through a 0.01 μm filter, using a pressure filter, to remove the salt. The solvent was removed under vacuum. The remaining yellow liquid was vacuum distilled to yield 1,349 grams of octanoylthiopropyltriethoxysilane as a clear, very light yellow liquid. The yield was 87 percent.
Example 1
Preparation of (2-triethoxysilylethyl)-bis-(3-thia-4-oxohexyl)cyclohexane
[0123] This example illustrates the preparation of a thiocarboxylate alkoxysilane from a silane containing two vinyl groups through the formation of an intermediate thioacetate silane.
[0124] The preparation of the (2-trimethoxysilylethyl)divinylcyclohexane was prepared by hydrosilation. Into a 5 L, three-neck round bottomed flask equipped with magnetic stir bar, temperature probe/controller, heating mantle, addition funnel, condenser, and air inlet were charged trivinylcyclohexane (2,001.1 grams, 12.3 moles) and VCAT catalysts (1.96 grams, 0.01534 gram platinium). Air was bubbled into the vinyl silane by means of the air inlet where the tube was below the surface of the silane. The reaction mixture was heated to 110° C. and the trimethoxysilane (1,204 grams, 9.9 moles) was added over a 3.5 hour period. The temperature of the reaction mixture increased to a maximum value of 130° C. The reaction mixture was cooled to room temperature and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxylbenzyl)benzene (3 grams, 0.004 mole) was added. The reaction mixture was distilled at 122° C. and 1 mmHg pressure to give 1,427 grams of (2-trimethoxysilylethyl)divinylcyclohexane. The yield was 51 percent.
[0125] The (2-triethoxysilylethyl)divinylcyclohexane was prepared by transesterification. Into a 3 L, three-neck round bottomed flask equipped with magnetic stir bar, temperature probe/controller, heating mantle, addition funnel, distilling head and condenser, and nitrogen inlet were charged (2-trimethoxysilylethyl)divinylcyclohexane (284 grams, 2.33 moles), sodium ethoxide in ethanol (49 grams of 21% sodium ethoxide, purchased from Aldrich Chemical) and ethanol (777 grams, 16.9 moles). The reaction mixture was heated and the methanol and ethanol were removed by distillation at atmospheric pressure. The crude product was then distilled at 106° C. and under reduced pressure of 0.4 mmHg to give 675 grams of product, 89 percent yield.
[0126] The (2-triethoxysilylethyl)bis-(3-thia-4-oxopentyl)cyclohexane was prepared by addition of thioacetic acid to the divinylsilane. Into a 1 L, three-neck round bottomed flask equipped with magnetic stir bar, temperature probe/controller, heating mantle, addition funnel, condenser, air inlet and a sodium hydroxide scrubber, was charged thioacetic acid (210 grams, 2.71 moles). The (2-triethoxysilylethyl)divinylcyclohexane (400 grams, 1.23 moles) was added slowly over a period of 30 minutes and at room temperature by means of an addition funnel. The reaction was an exothermic reaction. The temperature of the mixture increased to 94.6° C. The mixture was stirred for 2.5 hours and allowed to cool to 38.8° C. Additional thioacetic acid (10 grams, 0.13 moles) was added and a slight exothermal reaction was observed. The reaction mixture was stirred overnight (18 hours) at about 25° C. Analysis indicated that the reaction mixture contained less than 2 percent thioacetic acid. Its overall purity was 91 percent. The reaction mixture was further purified by a distillation using a Kugel apparatus under reduced pressure.
[0127] The dimercaptosilane intermediate was prepared by removing the acetyl groups from (2-triethoxysilylethyl)bis-(3-thia-4-oxopentyl)cyclohexane. Into a 5 L, three-neck round bottomed flask equipped with magnetic stir bar, temperature probe/controller, heating mantle, addition funnel, distilling head and condenser, 10-plate Oldershaw column and nitorgen inlet were charged (2-triethoxysilylethyl)bis-(3-thia-4-oxopentyl)cyclohexane (2,000 grams, 4.1 moles), ethanol (546.8 grams, 11.8 moles) and sodium ethoxide in ethanol (108 grams of a 21% sodium ethoxide in ethanol). The pH of the reaction mixture was about 8. The reaction mixture was heated to 88° C. for 24 hours to remove the ethyl acetate and ethanol from the reaction mixture. Twice ethanol (1 liter) was added to the mixture and the pH of the reaction mixture was increase to about 10 by the addition of 21% sodium ethoxide in ethanol (21 grams) and heated an additional 6.5 hours. The reaction mixture was cooled and then pressure filtered. The reaction mixture was stripped at a temperature less than 95° C. and 1 mmHg pressure. The stripped product was filtered to give (2-triethoxysilylethyl)bis(2-mercaptoethyl)cyclohexane (1398 grams, 3.5 moles, 86% yield).
[0128] The (2-triethoxysilylethyl)-bis-(3-thia-4-oxohexyl)cyclohexane was prepared by the acetylation of the bismercaptosilane. Into a 5 L, three-neck round bottomed flask equipped with magnetic stir bar, temperature probe/controller, ice/water bath, addition funnel and condenser were charged (2-triethoxysilylethyl)bis(2-mercaptoethyl)cyclohexane (1010.6 grams, 2.56 moles), triethylamine (700 grams, 6.93 moles) and methylene chloride (1000 grams). Propionyl chloride (473.8 grams, 5.12 moles) was added to the stirred reaction mixture over a 1.5 hour period. The reaction mixture temperature increased to 50° C. Additional propionyl chloride (45.4 grams, 0.49 mole) was added. The reaction mixture was filtered and the salts were mixed with 500 mL of methylene chloride and washed with three times with distilled water and twice with saturated sodium chloride solution. The organic phase was dried over anhydrous magnesium sulfate and then stripped at 124° C. and reduced pressure to remove the volatile components. The stripped product (1196 grams, 2.36 moles) was analyzed by GC/MS, NMR and LC and the yield was 92 percent.
[0129] One isomer of (2-triethoxysilylethyl)-bis-(3-thia-4-oxohexyl)cyclohexane has the following structure:
[0000]
Example 2 and 3
The Use of Silanes in Low Rolling Resistant Tire Tread Formulation
[0130] A model low rolling resistance passenger tire tread formulation as described in Table 1 and a mix procedure were used to evaluate representative examples of the silanes of the present invention. The silane in Example 1 was mixed as follows in a “B” BANBURY® (Farrell Corp.) mixer with a 103 cu. in. (1690 cc) chamber volume. The mixing of the rubber was done in two steps. The mixer was turned on with the mixer at 80 rpm and the cooling water at 71° C. The rubber polymers were added to the mixer and ram down mixed for 30 seconds. The silica and the other ingredients in Masterbatch 1 of Table 1 except for the silane and the oils were added to the mixer and ram down mixed for 60 seconds. The mixer speed was reduced to 35 rpm and then the silane and oils of the Materbatch 1 were added to the mixer and ram down for 60 seconds. The mixer throat was dusted down and the ingredients ram down mixed until the temperature reached 149° C. The ingredients were then mixed for an addition 3 minutes and 30 seconds. The mixer speed was adjusted to hold the temperature between 152 and 157° C. The rubber was dumped (removed from the mixer), a sheet was formed on a roll mill set at about 85° to 88° C., and then allowed to cool to ambient temperature.
[0131] In the second step, Masterbatch 1 was recharged into the mixer. The mixer's speed was 80 rpm, the cooling water was set at 71° C. and the batch pressure was set at 6 MPa. The Masterbatch 1 was ram down mixed for 30 seconds and then the temperature of the Masterbatch 1 was brought up to 149° C., and then the mixer's speed was reduce to 32 rpm. The zinc oxide and stearic acid were added (Masterbatch 2) and the rubber was mixed for 3 minutes and 20 seconds at temperatures between 152 and 157° C. During this mixing, the trimethylol propane was added (if needed). After mixing, the rubber was dumped (removed from the mixer), a sheet was formed on a roll mill set at about 85° to 88° C., and then allowed to cool to ambient temperature.
[0132] The rubber masterbatch and the curatives were mixed on a 15 cm×33 cm two roll mill that was heated to between 48° and 52° C. The sulfur and accelerators were added to the rubber (Masterbatches 1 &2) and thoroughly mixed on the roll mill and allowed to form a sheet. The sheet was cooled to ambient conditions for 24 hours before it was cured. The curing condition was 160° C. for 20 minutes.
[0133] Silane from Example 1 was compounded into the tire tread formulation according to the above procedure. The performance of the silanes prepared in Examples 1 was compared to the performance of silanes which are practiced in the prior art, bis-(3-triethoxysilyl-1-propyl)disulfide (TESPD), and Comparative Example A. The test procedures were described in the following ASTM methods:
[0000]
Mooney Scorch
ASTM D1646
Mooney Viscosity
ASTM D1646
Oscillating Disc Rheometer (ODR)
ASTM D2084
Storage Modulus, Loss Modulus,
ASTM D412 and D224
Tensile and Elongation
DIN Abrasion
DIN Procedure 53516
Heat Buildup
ASTM D623
Percent Permanent Set
ASTM D623
Shore A Hardness
ASTM D2240
[0134] The results of this procedure are tabulated below in Table 1.
[0000]
TABLE 1
Example Number
Comp.
Comp.
Example
Example
Ingredients
Units
B
C
2.00
3.00
Masterbatch 1
SMR-10, natural rubber
phr
10.00
10.00
10.00
10.00
Budene 1207, polybutadiene
phr
35.00
35.00
35.00
35.00
Buna VSL 5025-1, oil-ext. sSBR
phr
75.63
75.63
75.63
75.63
N339, carbon black
phr
12.00
12.00
12.00
12.00
Ultrasil VN3 GR, silica
phr
85.00
85.00
85.00
85.00
Sundex 8125TN, process oil.
phr
6.37
6.37
6.37
6.37
Erucical H102, rapeseed oil
phr
5.00
5.00
5.00
5.00
Flexzone 7P, antiozonant
phr
2.00
2.00
2.00
2.00
TMQ
phr
2.00
2.00
2.00
2.00
Sunproof Improved, wax
phr
2.50
2.50
2.50
2.50
Kadox 720C, zinc oxide
phr
—
—
—
—
Industrene R, stearic acid
phr
—
—
—
—
Aktiplast ST, disperser
phr
4.00
4.00
4.00
4.00
Silane TESPD
phr
4.50
—
—
—
Silane Comparative Example 1
phr
—
6.90
—
—
Silane Example 2
phr
—
—
9.68
9.68
TMP
phr
2.50
2.50
2.50
—
Masterbatch 2
Kadox 720C, zinc oxide
phr
2.50
2.50
2.50
2.50
Industrene R, stearic acid
phr
1.00
1.00
1.00
1.00
TMP
phr
—
—
—
2.50
Catalysts
Naugex MBT
0.10
0.10
0.10
0.10
Diphenyl guanidine
2.00
2.00
2.00
2.00
Delac S, CBS
2.00
2.00
2.00
2.00
Rubbermakers sulfur 167
2.20
2.20
2.20
2.20
total
phr
256.30
258.69
261.47
261.47
Specific Gravity
g/cm3
1.21
1.21
1.22
1.21
Physical Properties
Mooney Viscosity at 100 Celsius
ML1 + 3
mooney units
69.60
55.80
55.90
52.70
Minimum Torque (Mooney Low)
dNm
2.67
1.74
1.83
1.79
Maximum Torque (Mooney High)
dNm
19.31
18.17
19.89
19.40
Torque (Max − Min)
dNm
16.64
16.43
18.06
17.61
1.13 DNM RISE
min
1.30
1.50
1.15
0.98
2.26 DNM RISE
min
1.77
1.78
1.40
1.18
Cure, 160 Celsius for 20 minutes
T-10
min
1.65
1.70
1.37
1.15
T-40
min
2.50
2.27
2.01
1.65
T-95
min
13.36
15.00
19.80
17.62
cure time
min
20.00
20.00
20.00
20.00
50% Modulus
MPa
1.40
1.57
1.57
1.50
100% Modulus
MPa
2.53
2.83
2.80
2.80
300% Modulus
MPa
12.20
11.87
12.23
12.80
Reinforcement Index
4.82
4.19
4.37
4.57
Tensile
MPa
16.80
15.30
15.93
17.13
Elongation
%
425.20
406.40
410.40
416.90
M300 − M100
9.67
9.04
9.43
10.00
Durometer Shore “A”
shore A
66.80
67.90
68.90
68.50
Zwick Rebound, Room Temperature
percent
30.50
33.60
30.10
30.90
Zwick Rebound, 70 Celsius
percent
47.70
49.70
49.90
49.60
Delta Rebound, 70 C. − RT
percent
17.20
16.10
19.80
18.70
[0135] The data from Table 1 show an improvement in the delta rebound, an indicator of improve traction, and torque, an indicator of improved wear, while maintaining the other processing and physical properties when trimethylol propane was added as an activator.
EXAMPLES 4 AND 5
[0136] The rubber compounds described in Table 2 were prepared according to the procedures of Examples 2 and 3. The data from Table 2 show and improve in the delta rebound over the two comparative Example D and E.
[0000]
TABLE 2
Example Number
Comp.
Comp.
Example
Example
Ingredients
Units
D
E
4.00
5.00
Masterbatch 1
SMR-10, natural rubber
phr
10.00
10.00
10.00
10.00
Budene 1207, polybutadiene
phr
35.00
35.00
35.00
35.00
Buna VSL 5025-1, oil-ext. sSBR
phr
75.63
75.63
75.63
75.63
N339, carbon black
phr
12.00
12.00
12.00
12.00
Ultrasil VN3 GR, silica
phr
85.00
85.00
85.00
85.00
Sundex 8125TN, process oil.
phr
6.37
6.37
6.37
6.37
Erucical H102, rapeseed oil
phr
5.00
5.00
5.00
5.00
Flexzone 7P, antiozonant
phr
2.00
2.00
2.00
2.00
TMQ
phr
2.00
2.00
2.00
2.00
Sunproof Improved, wax
phr
2.50
2.50
2.50
2.50
Kadox 720C, zinc oxide
phr
—
—
2.50
—
Industrene R, stearic acid
phr
—
—
1.00
—
Aktiplast ST, disperser
phr
4.00
4.00
4.00
4.00
Silane TESPD
phr
4.50
—
—
—
Silane Comparative Example 1
phr
—
6.90
—
—
Silane Example 2
phr
—
—
9.68
9.68
TMP
phr
—
—
—
—
Masterbatch 2
Kadox 720C, zinc oxide
phr
2.50
2.50
—
2.50
Industrene R, stearic acid
phr
1.00
1.00
—
1.00
TMP
phr
—
—
—
—
Catalysts
Naugex MBT
0.10
0.10
0.10
0.10
Diphenyl guanidine
2.00
2.00
2.00
2.00
Delac S, CBS
2.00
2.00
2.00
2.00
Rubbermakers sulfur 167
2.20
2.20
2.20
2.20
total
phr
253.80
256.20
258.97
258.97
Specific Gravity
g/cm3
1.21
1.21
1.21
1.21
Physical Properties
Mooney Viscosity at 100 Celsius
ML1 + 3
mooney un
75.50
67.10
61.20
60.60
Minimum Torque (Mooney Low)
dNm
2.99
2.26
1.96
2.04
Maximum Torque (Mooney High
dNm
18.52
17.40
17.55
17.82
Torque (Max − Min)
dNm
15.53
15.14
15.59
15.78
1.13 DNM RISE
min
0.80
1.97
1.39
1.80
2.26 DNM RISE
min
1.73
2.41
1.76
2.17
Cure, 160 Celsius for 20 minutes
T-10
min
1.41
2.24
1.64
2.05
T-40
min
3.09
3.12
2.37
2.81
T-95
min
11.20
10.87
12.23
12.22
cure time
min
20.00
20.00
20.00
20.00
50% Modulus
MPa
1.20
1.33
1.20
1.20
100% Modulus
MPa
2.00
2.40
2.10
2.17
300% Modulus
MPa
10.47
11.03
10.53
10.53
Reinforcement Index
5.24
4.60
5.01
4.86
Tensile
MPa
17.33
16.27
17.23
16.57
Elongation
%
470.40
446.60
474.00
462.80
M300 − M100
8.47
8.63
8.43
8.36
Durometer Shore “A”
shore A
62.60
64.40
63.00
64.60
Zwick Rebound, Room Temperat
percent
32.00
35.00
33.20
31.60
Zwick Rebound, 70 Celsius
percent
47.70
50.40
50.00
48.60
Delta Rebound, 70 C. − RT
percent
15.70
15.40
16.80
17.00
indicates data missing or illegible when filed
Example 6
Preparation of (2-triethoxysilylethyl)-bis-(3-thia-4-oxounidecyl)cyclohexane
[0137] This example illustrates the preparation of a thiocarboxylate alkoxysilane from a silane containing two vinyl groups and a thioacid. Into a 3 L, three-neck round bottomed flask equipped with magnetic stir bar, temperature probe/controller, heating mantle, addition funnel, condenser, air inlet and a sodium hydroxide scrubber, was charged thiooctanoic acid (780.1 grams, 4.87 moles). Air was bubbled into the thioacid by means of the air inlet where the tube was below the surface of the thioacid. (2-Triethoxysilylethyl)-divinylcyclohexane (755.0 grams, 2.31 moles) was added slowly to the thioacid by means of an addition funnel over a period of 32 minutes. The addition started at 22.3° C. and a slight exothermal reaction occurred which raised the temperature to 34.9° C. The reaction mixture was then slowly heated to 84.8° C. over 3 hours. Di-tert-butyl peroxide (1.1 grams) was added and stirred for 2 hours. 2,2′-Azoisobutyronitrile (1.2 grams, from Aldrich Chemical) was added and the mixture was heated for an additional 4.4 hours at 85° C. The thiooctanoic acid (32.4 grams) was removed under reduced pressure (0.5 mmHg) and elevated temperature of 167° C. to give 1,472.1 grams of product. 13 C NMR analysis indicated that 95% reaction occurred between the thiooctanoic acid and the vinyl groups of (2-triethoxysilylethyl)divinylcyclohexane.
Example 7
Preparation of (2-triethoxysilylethyb-bis-(3-thia-4-oxohexyl)cyclohexane
[0138] This example illustrates the preparation of a thiocarboxylate alkoxysilane from a silane containing two vinyl groups and a thioacid. Into a 3 L, three-neck round bottomed flask equipped with magnetic stir bar, temperature probe/controller, heating mantle, addition funnel, condenser, air inlet and a sodium hydroxide scrubber, was charged thiopropanoic acid (591.8 grams, 6.49 moles). Air was bubbled into the thioacid by means of the air inlet where the tube was below the surface of the thioacid. (2-Triethoxysilylethyl)-divinylcyclohexane (1052.0 grams, 3.22 moles) was added to the thioacid by means of an addition funnel over a period of 15 minutes. The addition started at 21.0° C. and an exothermic reaction occurred which raised the temperature to 86.7° C. After 70 minutes, the reaction mixture was then heated to maintain a temperature of about 86° C. for an additional 20 minutes. 2,2′-Azoisobutyronitrile (1.2 grams, from Aldrich Chemical) was added and the mixture was heated for one hour at 86° C. Di-tert-butyl peroxide (2.0 grams) was charge to the reaction mixture and heated for 7 hours at 86° C. The thiopropanoic acid was removed under reduced pressure (0.5 mmHg) and elevated temperature of 70° C. to give the product.
[0139] While the above description contains many specifics, these specifics should not be construed as limitations of the invention, but merely as exemplifications of preferred embodiments thereof. Those skilled in the art will envision many other embodiments within the scope and spirit of the invention as defined by the claims appended hereto. | The invention relates to sulfur silane coupling agents containing multiple blocked mercapto groups which are in a state of reduced activity until activated. The coupling agents are advantageously used in rubber formulations, for example, for fabricating tires with low rolling resistance. | 8 |
BACKGROUND OF THE INVENTION
The invention is related to a process for the adjustment of a travel sensor for a vacuum brake booster for automotive vehicle brake systems having an anti-locking device. The electrical travel sensor monitors the position of a movable wall which furnishes the boosting power of the vacuum brake power booster. In particular, the invention relates to a process for the adjustment of the desired axial distance between an actuating element of the travel sensor and the movable wall.
It is, for example, known from the German patent application published without examination, No. 3,731,603, corresponding to U.S. Pat. No. 4,826,255, to sense the position of the movable wall in order to safeguard the regular functioning of brake systems with anti-locking device which work as "open" systems. U.S. Pat. No. 5,141,295 filed on Dec. 19, 1989 assigned to the assignee of this application also describes such movable wall sensor for a brake power booster for this purpose.
In these arrangements, a rotary hydraulic pump is provided, which, in one control mode, aspirates hydraulic fluid out of an unpressurized supply tank, and with the wheel valves in the closed condition, delivers the same into the master brake cylinder in order to properly position the brake pedal. For this purpose, a travel sensor, for example, a travel-controlled electric switch, is envisaged which supplies an electrical signal depending on the position of the movable wall to an electronic control system which controls the pumping rate of the pump.
The vacuum brake power booster, in particular its housing, is subject to sizable working tolerances which have a negative effect on the functioning of the travel sensor and, in an extreme case, may even lead to the total failure of the brake system.
It is, therefore, the object of the invention to provide a process for the adjustment of the exact position of the electrical travel sensor in respect of the movable wall of a vacuum brake power booster, which affords a virtual elimination of the influence of its working tolerances on the functioning of the travel sensor.
SUMMARY OF THE INVENTION
According to the invention, this object is achieved by the following process steps:
a) installing a stop in the booster housing for the output member driven by the booster movable wall, the stop having a defined length;
b) applying a vacuum to the vacuum chamber in the booster housing;
c) actuating the vacuum brake power booster by applying a predetermined input force which shifts the position of the movable wall to abut the output member with the stop and bring the movable wall to a test location;
d) determining the distance between a reference surface at the booster housing and the movable wall at the test location;
e) comparing the distance in step d) to a distance from a reference surface of the travel sensor to the tip of an actuating element with the tip located at a point located so that the travel sensor signal output corresponds to the test location of the movable wall;
f) installing the travel sensor in the booster housing while locating the travel sensor reference surface by means of the booster housing reference surface using a suitable spacing means to locate the tip of the actuating element at the test location of the movable wall with said travel sensor actuating element set in said travel sensor at said location corresponding to said test location.
The spacing means employed can be the selection of a replaceable tip sized to create the appropriate spacing distance.
Another spacing means can be provided by selecting a properly sized holder installed in the booster housing with the travel sensor assembled into the holder. The holder can also be adjustable to vary the location of the installed travel sensor. By these two latter operations an exchange of the travel sensor will be simplified, and the advantage offered by this approach consists in that in this case, the adjustment is carried out at the brake power booster whose condition is no longer changed. In the former approach using replaceable tips, the adjustment is carried out at the travel sensor, so that it must be carried out again in the event the travel sensor is replaced.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially sectional view of a power booster and a diagrammatic representation of a measuring arrangement for carrying out the inventive process;
FIG. 2 is a partially sectional view of a power booster and travel sensor which has been adjusted in accordance with the invention;
FIG. 3 is an enlarged, fragmentary, and partially sectional view of a first embodiment of a sensor accommodating element positioning the travel sensor; and
FIG. 4 is an enlarged, fragmentary, and partially sectional view of a second embodiment of the sensor accommodating element.
DETAILED DESCRIPTION
FIG. 1 shows a vacuum brake power booster 1 which is to be equipped with a travel sensor, not shown in the drawing, which is connected through a non-return valve 6 to a vacuum source 2. The booster housing 10 is sealed to be airtight. A diagrammatically illustrated stop 3 having a portion projecting into the booster housing 10 of defined length Y, is installed during the measuring procedure. The stop 3 serves to engage a power output member 9 transmitting the output power of the vacuum brake power booster 1, with a predetermined input force F exerted on the input member of the booster.
Simultaneously, a sensor accommodating element 7 is inserted in an opening 8 being provided in the booster housing 10, the opening 8 accommodating installation of the aforementioned travel sensor after the adjustment process is complete.
In the course of the measuring procedure, a measuring instrument 4 is introduced through the sensor accommodating element 7 and sealed off by means of a seal 5. The function of the measuring instrument 4 consists in determining, at a fixed moment with the movable wall 11 at a test location with the input force F applied and the output member 9 against the stop 3, the distance A between a travel sensor mounting reference surface which is defined at the booster housing 10, i.e., between the front face 12 of the sensor accommodating element 7, on one hand, and a movable wall 11 which exerts the boosting power of the vacuum brake power booster 1 on the output member 9. The predetermined known input force F having been applied to the input member, the movable wall 11 is advanced so that the power output member 9 is caused to be slid in the direction of the stop 3 until the power output member 9 abuts against the stop 3. As a result, the movable wall 11 comes to be positioned in an advanced test location shown in phantom lines.
The axial distance A between the front face 12 of the sensor accommodating element 7 and the movable wall 11 corresponding to that position is compared to a functional length measure of the travel sensor 13 (FIG. 2) to be used whose actuating element 14 interacts with the movable wall 11 during operation. The said functional parameter preferably corresponds to the distance from a reference surface on the travel sensor 13 to the tip of the actuating element 14 at the moment when a predetermined signal output of the travel sensor 13 is reached, corresponding to the test location of the movable wall 11.
Subsequently, the correct length of a spacing element, for example of a spacing cap 15, is determined on the basis of the result of the forementioned comparison. In order to facilitate the correlation of the spacing caps 15 of different length to the results of the comparison, it is envisaged that a defined color corresponds to each length measure of the spacing caps 15, for example red, green, blue or white. Upon the selection of the right spacing cap 15, the latter is plugged onto the end of the actuating element 14 and the travel sensor 13 is introduced into the sensor accommodating element 7 and secured against sliding by means of a retaining ring 16. This completes the adjusting procedure.
FIG. 3 shows a first embodiment of a sensor accommodating element 17 which corresponds to a positioning of the travel sensor 13 in respect of the movable wall 11 mentioned before and not shown in the drawing, so that the adjustment is carried out directly at the vacuum brake power booster housing 11. For this purpose, for example four groups of sensor holders 17 of different dimensions are furnished one of which is selected depending on the distance between the aforementioned reference surface and the movable wall 11. In this case, the reference surface is constituted by the surface of the booster housing 10 which accommodates the travel sensor 13. As will be seen in FIG. 3, the sensor holder 17 is provided projecting into the inner space of the booster housing 10 with a plurality of locking projections 18 which in the mounted condition of the sensor holder 17 within the booster housing 10 catch behind the edge of the opening 8 which is provided for the purpose.
An elastic seal, preferably an O-ring 27, which is positioned between the surface of the booster housing 10 and an annular surface 28 on the sensor holder 17 provide effective sealing of the sensor 17 to the booster housing 10. In order to fix the travel sensor 13 in the sensor holder 17 upon its mounting, the portion protruding outside the booster housing 10 is formed, with a radial peripheral groove 19 which accommodates the retaining ring 16 holding the travel sensor 13. The distance L between the surface of the booster housing 10 and the flank of the peripheral groove 19 which is positioned nearer to the booster housing 10 is the dimension defining the proper holder 17 to achieve proper adjustment of the travel sensor.
The sensor holder 17 may be fixed within the booster housing 10 by other means such as, for example by a bayonet catch. For this purpose, the sensor holder 17 is furnished, for example, with a plurality of radial projections which are inserted into matching clearances in the booster housing 10, whereupon the sensor holder 17 is rotated so that the projections again are engaged behind the edge of the opening 8, the seal which seals off the sensor accommodating element furnishing the necessary prestressing and retaining force for the bayonet locking.
The sensor holder assembly 20 shown in FIG. 4 affords adjustment of its overall length to properly locate the tip of the travel sensor 13. It is composed of a first part 21 which is passed through the booster housing opening 8 from the inside, and of a second part 22 which is positioned outside the booster housing 10. The first and second parts 21, 22 are coupled to each other by means of a threaded union 29.
In the course of mounting of the illustrated sensor accommodating assembly 20, the first part 21 is plugged through the opening 8 and is secured against falling out by means of a spring ring 23. After determining the above-mentioned distance "A" between the movable wall and the reference surface at the booster housing 10, and upon having fixed the length "L" which determines the position of the mounted travel sensor 13, the second part 22 is screwed onto the first part 21, the first part 21 being rotated with a tool (not shown) engaging with grooves 25. In the final phase of threaded advance, a nose 24 at the end of the second part 22 facing the first part 21, enters a gap being provided in the booster housing 10 adjacent opening 8. The nose 24 after entering the opening prevents the second part 22 from rotating, to constitute an antirotation means.
In this design version, the seal 27 which seals the second part 22 to the booster housing 10 is positioned in an annular groove 26 in the front side of the second part 22 which faces the booster housing 10. The groove flanks are inclined so that the seal 27 cannot fall out of the annular groove 26 in the course of mounting
As soon as the length "L" defined before is reached by threading of part 22 on part 21, the adjusting procedure is ended, so that the travel sensor 13 can be inserted and be located and secured by means of the retaining ring 16. In this context, the front face of the first part 21 which faces away from the inner space of the booster housing 10 serves as a supporting surface for the seal 5 which seals off the travel sensor 13 in respect of the sensor holder assembly 20. | A process for adjusting the travel sensor for a brake power booster movable wall is disclosed to compensate for tolerance variations, in which a fixed stop is installed to engage the output member upon applying a predetermined input force to shift the movable wall to a test location. The distance to the test location of the movable wall from a booster housing reference surface is measured with a measuring instrument installed temporarily in the booster housing opening normally receiving the travel sensor. The tips of the travel sensor is positioned at the test location with the travel sensor in the corresponding signal condition either by using an appropriately dimensioned replaceable tip or sensor holder, or by use of an adjustable length sensor holder. | 1 |
This application claims the benefit of U.S. Provisional Patent Application No. 61/301,749, filed Feb. 5, 2010.
BACKGROUND AND SUMMARY
Conventional systems in a vehicle for measuring ambient air temperature include a sensor placed on the vehicle in a location exposed to ambient air. Any location on the vehicle, however, is subject to heat generated by the vehicle engine, exhaust, transmission, etc., which could influence a temperature measurement. When the vehicle is stationary or moving slowly, for example, a boundary layer of hot air exists around the engine compartment and exhaust components, and ambient air temperature measurement is influenced by the heat in this boundary layer.
Various methods for reducing or correcting for the effect of vehicle-generated heat are known. U.S. Pat. No. 5,813,765 to Peel et al. includes placing the temperature sensor on the radio antenna to locate it as far as possible from vehicle heat sources. U.S. Pat. No. 7,387,437 to Brown et al. discloses using multiple sensors placed at different locations on the vehicle, comparing the readings from the multiple sensors, and applying a correction factor generated according to vehicle speed and other factors. U.S. Pat. No. 4,770,543 to Burghoff et al. discloses a method including monitoring vehicle speed and using a temperature measured when speed exceeds a threshold, and, when speed drops below the threshold, storing and using a last temperature measurement before the speed dropped below the threshold.
The invention improves on the art in proposing a method and system for measuring ambient air outside a vehicle that overcomes deficiencies in the art. According to the invention, a temperature sensor is mounted in a flow path of an air blowing or moving device, such as the engine radiator fan. A controller is configured to monitor at least one vehicle parameter, compare the vehicle parameter to a reference parameter, and responsive to the comparison, control the air blowing device and make an ambient air temperature reading.
According to the invention, the vehicle parameter may be a vehicle speed value, and the air blowing device is controlled to be activated to move ambient air across the sensor if the vehicle speed value is below a road speed reference value stored in a controller memory.
According to another aspect of the invention, the method includes the steps of monitoring the vehicle speed for a measured interval after taking the temperature reading, and, if the determined road speed remains below the road speed reference value during the interval, further including activating the device to move ambient air across the sensor, taking a temperature reading with the sensor, and holding the temperature reading as the current ambient air temperature if the temperature reading is lower than the stored temperature value.
According to another aspect of the invention, the sensor is mounted in an air flow path of a vehicle radiator fan, and the step of controlling the device to move ambient air across the sensor comprises activating the radiator fan.
Alternatively, an air blowing device to move air across the sensor may be provided if locating the sensor in the radiator fan flow path is not convenient or desired.
According to another aspect of the invention, the method includes applying a correction to the temperature reading and storing the corrected temperature reading as the ambient air temperature. The correction may compensate for the effect of heat not removed by the activated fan, and may constitute a subtraction of 2 degrees Celsius.
The method also includes the step of communicating the current ambient air temperature to vehicle components, for example, by broadcasting a temperature signal on the CAN bus. The Engine Management System and other controllers can then make use of the temperature information to perform various functions.
According to the invention, the method includes taking a plurality of temperature readings during a predetermined time duration while the fan is activated and storing a lowest temperature reading as the current ambient air temperature.
According to another aspect of the invention, if the determined road speed is above the road speed reference value, for example 50 kph, for at least a predetermined time duration, the method includes continuously taking temperature readings as the ambient air temperature. The predetermined time duration may be set at 90 seconds to allow sufficient air flow over the temperature sensor to remove enough engine heat for an accurate ambient air temperature reading.
According to yet another aspect of the invention, if the determined road speed is above a second road speed reference value, for example 80 kph, which is higher than the first road speed reference value, the method includes immediately continuously taking temperature readings and storing a lowest value as the ambient air temperature.
According to another aspect of the invention, the method includes monitoring the engine temperature, and upon determining that the engine temperature is below a reference temperature, for example, 50 degrees Celsius, which indicates a cold engine start, taking a temperature reading with the sensor, and, holding the temperature reading as the current ambient air temperature.
According to yet another aspect of the invention, the method includes monitoring the engine temperature and if the engine temperature is above the reference temperature, for example, 50 degrees Celsius, which indicates a warm engine or may indicate a warm engine start, holding the last held temperature reading as the current ambient air temperature for a measured interval, activating the device to move ambient air across the sensor after the measured interval, taking a temperature reading with the sensor and, holding the temperature reading as the current ambient air temperature if the temperature reading is lower than the held temperature value. The measured interval for holding the last held temperature may be 60 minutes, for example.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a schematic representation of an embodiment of a system according to the invention;
FIG. 2 is a schematic representation of a controller arrangement in accordance with the invention;
FIG. 3 is a functional diagram of a portion of an embodiment of a method according to the invention; and
FIG. 4 is a diagram of another portion of the method of FIG. 3 .
DETAILED DESCRIPTION
An exemplary embodiment of a system for determining ambient temperature according to the invention is illustrated schematically in FIG. 1 . The system includes a temperature sensor 10 mounted on the vehicle (not illustrated) in an air flow path 12 of an air blowing device or fan 14 . The fan 14 may conveniently be the vehicle radiator fan. Alternatively, a dedicated fan may be provided if mounting the temperature sensor near the radiator is not desired. The fan 14 or air blowing device is arranged to draw air from outside the vehicle, i.e., ambient air, and move it across the temperature sensor.
A controller 20 is connected to receive temperature readings from the temperature sensor 10 . The sensor 10 may be connected to an instrument cluster module (See, FIG. 2 ) which receives the temperature reading and passes it to a Vehicle Electronic Control Unit (ECU). The controller 20 is also connected to the fan 14 to control operation of the fan, and is connected to receive signals from a vehicle speed sensor 22 and engine temperature sensor 24 . The controller may be implemented as a single device, which in this described embodiment is the Vehicle ECU.
The controller 20 broadcasts the ambient air temperature value onto the vehicle data network 26 , for example, a J1939 CAN link to communicate the value to other systems on the vehicle that make use of the temperature value. This may include, for example, the instrument cluster, which displays the temperature value to the driver, and the Engine Management System. The Engine Management System may use the ambient air temperature in performing certain functions, for example, in exhaust aftertreatment systems temperature models, in mass flow calculations and condensation protection, and controlling exhaust gas recirculation cooler cleaning, among others.
Alternatively, the controller 20 may comprise several devices interconnected for communication by the vehicle data bus, each performing one or more of the control functions, as illustrated in FIG. 2 . For example, the controller 20 may be implemented as and comprise an Engine Management unit 32 controlling the fan and reading engine temperature, an Instrument Cluster unit 34 reading ambient temperature, and a Vehicle ECU 30 reading vehicle speed and performing other logic. In this arrangement, the Instrument Cluster 34 provides the temperature sensor reading to the VECU 30 and to a Climate Control unit 36 . The VECU 30 logic, as explained below, includes correcting the temperature sensor reading to produce an ambient temperature signal for the EMS 32 . Other configurations are also possible.
The controller 20 contains control logic and processes the ambient air temperature signal. According to the invention, the temperature sensor value may be processed by applying a correction factor. According to the invention, the correction factor may be a subtraction of 2 degrees C. to compensate for the effects of heat that cannot be removed by the activation of the fan.
An exemplary embodiment of a method according to the invention is shown in the functional diagrams of FIGS. 3 and 4 . The method as shown should not be understood as requiring certain steps to be performed in a particular sequence; rather, the figures show relationships between and among functions, and, as described below, it should be understood that certain functions may be performed continuously or performed simultaneously in parallel, and depending on the result of a function, subsequent functions may then be performed.
The controller 20 determines the ambient air temperature according to the method described below, and holds and communicates the ambient air temperature to other vehicle components, which may be as described above. The terms “held” or “hold” here means storing the value in memory and using that stored value when communicating the ambient air temperature. According to the invention, when the engine is shut off, the controller will hold the currently held temperature value until a new value is held.
Referring now to FIG. 3 , the controller 20 will access various vehicle systems or sensors to monitor vehicle parameters 40 , including engine temperature (e.g., engine oil or coolant temperature), vehicle speed, and key position. Monitoring vehicle parameters continues as other functions are performed, as certain values for vehicle parameters will determine that functions are performed, overriding other functions, as will be understood. The value for engine temperature is compared to a reference temperature. The value for vehicle speed is compared to a reference first speed and a reference second speed, which is higher than the first speed.
If the controller 20 determines that the engine temperature is below an engine temperature reference value 42 , for example a coolant temperature of 50 degrees Celsius, which may indicate a cold engine start, the ambient temperature sensor 10 is read continuously and the value broadcast continuously 44 . The controller 20 continues to monitor vehicle parameters.
Similarly, if the controller 20 determines that the vehicle speed has been above the first reference vehicle speed for more than a predetermined time interval 42 , the ambient temperature sensor 10 is read continuously and the value broadcast continuously. The first reference vehicle speed is high enough that an air flow over the sensor is sufficient to give an accurate temperature reading, which hi this embodiment is 50 kph. The predetermined time interval is sufficiently long to provide an ambient air flow to remove from the sensor and its environs heat that may be present if the vehicle had been stopped or moving slowly. In this embodiment, the predetermined time interval is 90 seconds. The controller continues to monitor the vehicle parameters 40 .
Also, if the controller 20 determines that the vehicle speed is above the second reference vehicle speed, which in this embodiment is 80 kph, the ambient temperature sensor 10 is read continuously and the value broadcast continuously 44 . This second, higher speed reference is sufficiently high, and will involve a sufficiently long acceleration time, that the temperature sensor 10 reading is considered accurate. The controller 20 continues to monitor vehicle parameters.
If the controller determines that the vehicle speed is below the first reference speed or the engine temperature is above the engine reference temperature value, the last valid temperature sensor reading is held 48 . A 60 minute delay timer is started 50 . Note that the vehicle parameters continue to be monitored. After 60 minutes, if the vehicle parameters have not changed (i.e., the speed remains below the reference vehicle speed and/or the engine temperature remains above the reference engine temperature), the fan is requested 52 .
Turning to FIG. 4 , the fan request results in the fan being activated 60 . A maximum fan run time is calculated 62 based on vehicle parameters related to heat generation and vehicle speed when power take-off equipment is in use. For example, the maximum fan run time may be calculated as follows: if the vehicle is moving at less than a PTO speed (in a speed range within which power take off equipment may operate, in this embodiment 8 kph) and the engine torque is greater than a PTO torque (here, 50% of maximum engine torque) and the coolant temperature is above a PTO coolant temperature (here, 80 degrees C.), the maximum fan run time is set at 5 minutes. Otherwise, the maximum fan run time is set at 150 seconds. The fan run times are calculated to provide a sufficient flow of air to the sensor to remove enough engine heat to allow an accurate ambient air temperature reading.
Once the fan starts, the controller reads the temperature sensor immediately and repeats reading at read intervals 64 . The read interval may be set at a duration appropriate to detect changes in the temperature sensor reading induced by the active fan, for example 60 seconds.
The controller monitors vehicle parameters for conditions related to determining a valid temperature reading 66 . The controller monitors the fan run time to determine if the maximum fan run time has been reached 72 or that the vehicle speed has been above the first vehicle reference speed for more than 90 seconds 74 or that the vehicle speed is above the second vehicle reference speed 76 or that the engine temperature is below the reference engine temperature 78 . If any of those parameters is met, the fan is stopped 70 . An override may be provided to protect the fan clutch by keeping the fan on for a minimum fan run period, for example, 30 seconds.
If none of the parameters of fan run time 72 , vehicle speed 74 , 76 , or engine temperature 78 is met, the controller continues to read the temperature sensor at the read intervals, and continues to monitor the fan run time, vehicle speed, and engine temperature. Again, if any of the vehicle parameters is met, as described above, the fan is stopped 70 .
Alternatively, the controller may monitor for minimum fan run time, and at the end of the minimum run time, the controller will compares read temperature values to determine if the values are changing or stable. If the values are not changing or are changing within a minimum range, that is the readings differ by no more than a minimal amount, for example 1 degree C., the controller may determine that a valid temperature reading has been taken and stop the fan. If the temperature readings are not within the minimum range, the controller would continue to monitor the parameters or fan run time, vehicle speed, and engine temperature as described above.
Once the fan is stopped, the lowest read temperature sensor value is held and broadcast as the ambient temperature 48 and the hold timer is again run for 60 minutes 50 , returning to the function as described in connection with FIG. 3 . Also, as described above, the controller continues to monitor vehicle parameters of vehicle speed and engine temperature, which can trigger an interruption of the timer.
Referring to FIG. 3 and to step 48 , when the controller holds the last valid ambient temperature value, it continues to monitor the temperature sensor and compare the readings to the held value 54 . If a read value is lower than the held value, the lower value is held as the ambient air temperature 56 .
If the controller determines that the key position is “off”, indicating that the vehicle has been shut down 80 , the last valid temperatures sensor reading is held as the ambient air temperature 82 and the hold timer continues to run. If the vehicle is started within the hold timer run time, the controller will determine ambient temperature according to the function described in connection to the hold timer (refer to step 50 ) or until the system detects a change in vehicle parameters calling for a new temperature sensor reading.
The invention has been described in terms of preferred principles, embodiments, components, and steps, but those of skill in the art will recognize that substitutions may be made without departing from the scope of the invention as defined in the following claims. | A method for determining ambient air temperature outside of a vehicle with a sensor mounted on the vehicle, includes the steps of determining a road speed of the vehicle, comparing the determined road speed to a reference road speed value, if the determined road speed is below the reference road speed value, activating a device to move ambient air across the sensor, the ambient air being drawn from a location outside the vehicle, taking a temperature reading with the sensor, and, if the temperature reading is lower than a stored temperature value, storing the lower temperature reading as the ambient air temperature. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION OR PRIORITY
[0001] This application is a continuation of co-pending International Application No. PCT/DE03/01859 filed Jun. 3, 2003, which designates the United States, and claims priority to German application number DE10225686.1 filed Jun. 10, 2002.
FIELD OF THE INVENTION
[0002] The present invention relates to a travel-transmitting element for an injection.
BACKGROUND OF THE INVENTION
[0003] Such an element is known from DE 199 62 177 A1, in which the travel-transmitting element has a pressure-loaded storage chamber area, the boundaries of which are elastically formed. Despite the different coefficients of thermal expansion that exist among the individual components within injection valves (e.g., ceramic, steel and hydraulic fluid), this thermal compensating element can make a positive tie between the individual components of an injection valve in the overall operating range; it is important to take into account among other things the steadiness of the rotational speed in respect of the travel-transmitting element. According to DE 199 62 177 A1 the storage chamber area is bounded by a sprung bellows arrangement made of metal. The first disadvantage of this is that metal bellows arrangements are costly to manufacture and therefore, relatively expensive. Since metal bellows are very stiff in the radial direction, volume compensation takes place in the axial direction. Metal bellows exhibit a linear spring characteristic during small displacements only. During larger displacements, such as can occur, for example, during an operating temperature variation, the bellows show marked hysteresis effects. Due to the settlement and hysteresis properties of the individual bellows, an additional spring element is necessary in order to ensure perpetuation of the storage chamber pressure and thereby, the ability to operate even at high engine speeds. Another disadvantage in the case of this metal bellows arrangement is that the dynamic characteristics can change during operation.
[0004] Alternatively, according to DE 199 62 177 A1 the storage chamber area with the elastically formed boundaries can also be made from elastomeric material. Volume compensation can then be achieved by radial movement of the bellows. In the axial direction, these elements are relatively soft, which is necessary in order for the actuator to generate sufficient travel. However, known elastomeric materials exhibit creep properties, and in the course of inevitable ageing, this leads to a loss of radial stiffness and in turn to an unwelcome loss of pressure in the storage chamber. Therefore, steadiness of the rotational speed would not be provided even in the case of an elastomeric bellows-type member.
SUMMARY OF THE INVENTION
[0005] The object of the invention is to provide a travel-transmitting element for an injection valve, ensuring sufficient steadiness of the rotational speed over the service life.
[0006] According to the invention, this object is achieved by means of a travel-transmitting element having an elastomeric bellows-type member with a stiffening element which ensures constant radial stiffness over the service life in at least some sections thereof. Then despite ageing of the elastomeric material, unwanted pressure loss over the service life is prevented by the elastic stiffening element. It is possible to provide a suitable additional element to generate the counter-force for an injection valve actuator, if necessary this element being one that is known from prior art.
[0007] The travel-transmitting element can be embodied in a particularly compact form if the stiffening element or at least some part thereof increases the axial stiffness of the elastomeric material to the smallest extent at the same time. Then at least a section of the elastomeric bellows-type member can provide both the storage element function and the actuator counter-force function at the same time. The stiffening element is optimally chosen so that it particularly compensates for the loss of radial stiffness due to ageing of the elastomeric material without increasing the axial stiffness of the storage element too greatly. If the stiffening element extends the full length of the elastomeric bellows-type member, the geometry of both the elastomeric bellows-type member and the stiffening element must be chosen with particular care to achieve the respective requirements of this compromise.
[0008] According to a preferred embodiment, it is proposed that the elastomeric bellows-type member, which is connected in series using spring technology, shall have a first section A and a second section B, the stiffening element being provided in the second section only. A suitable choice of geometry makes the first section A stiffer in the radial direction than the second section. The stiffening element makes the second section B stiffer in the axial direction than the first section A. The two sections A and B are connected in series in the axial direction so that the reciprocals of each axial stiffness are added together. When the actuator causes an overall displacement, the additional counter-force acting on the actuator is therefore, to a first approximation only, determined by the first section A with the lower stiffness. In addition, due to the lower radial stiffness of the second section B, and to a first approximation only, the existing volume of hydraulic fluid leads to a bellows-like movement in the second section B. Assigning the properties in both sections of the elastomeric bellows-type member therefore enables the properties of the travel-transmitting element to be set to their optimum.
[0009] According to the invention, in order to be able to provide a compact and sturdy travel-transmitting element or storage element, it is further possible for the stiffening element in the elastomeric bellows-type member, which is embodied in particular in the form of a sleeve, to be inserted by injection. This applies to an increased extent if a bottom plate and/or head plate are connected by means of extrusion technology to the elastomeric bellows-type member and the stiffening element to form a standard component.
[0010] The injection valve with travel-transmitting element to which the invention relates will be disclosed by means of a typical embodiment and figures described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a greatly simplified cross-section of an injection valve, and FIG. 2 shows an enlarged perspective representation of a storage element in the travel-transmitting element.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] According to FIG. 1 , an injection valve comprises an actuator 1 which uses a travel-transmitting element, having a hydraulic inverter 3 to control the movement of a valve needle 5 , thereby controlling the fuel injection procedure. For this purpose, the valve needle 5 is moved in a known way within a valve needle housing 9 fitted with corresponding valve openings 7 , so that the valve according to FIG. 1 opens inwards or outwards. A needle tappet 11 and a linked actuator tappet 13 are enclosed in a hydraulic fluid filled housing 12 of the hydraulic inverter 3 . Movement of the actuator 1 is transmitted by the actuator tappet 13 to the needle tappet 11 and then to the valve needle 5 . For the purpose of thermal volume compensation for the hydraulic fluid, the travel-transmitting element has a storage chamber 15 in the housing 12 as well as an ancillary storage chamber 16 formed within an ancillary elastic storage element 17 . The elastic wall sections of the storage element 17 are provided by an elastomeric bellows-type member 19 which also provides the axial counter-force for the actuator 1 . The elastomeric bellows-type member 19 , which is shaped like a hollow cylinder, is tightly connected at the front end to both a bottom plate 21 and a head plate 23 . The bottom plate 21 closes off the housing 12 of the hydraulic inverter 3 and has a corresponding opening for the actuator tappet 13 . The head plate 23 is tightly connected at the actuator end to the actuator tappet 13 . The annular space between the actuator tappet 13 and the inner wall of the elastomeric bellows-type member 19 thus forms the ancillary storage chamber 16 with the elastic wall sections. The ancillary storage chamber 16 has a suitably dimensioned annular space 25 , formed in the region of the opening of the housing 12 between this and the actuator tappet 13 , to which the storage chamber 15 formed in the housing 12 of the hydraulic inverter 3 is connected by fluid technology.
[0013] In the axial direction, the elastomeric bellows-type member 19 of the storage element 17 has a first section A and a second section B with different axial and radial elasticity properties. The two sections A, B provide different functions of the storage element 17 and are appropriately adjusted with respect to each other according to requirements. Arranged in the second section B of the elastomeric bellows-type member 19 is a stiffening element 27 formed by a sleeve-shaped metal net, for instance ( FIG. 2 ). By this means, this section is radially softer than in the case of entirely metal bellows according to the known prior art, and in fact soft enough that the additional volume of the hydraulic fluid can be taken up in the storage element 17 without a sharp rise in pressure. This metal net 27 also ensures constant radial stiffness in the second section B of the elastomeric bellows-type member 19 despite creep in the elastomeric material over its service life. At the same time, the geometry of the elastomeric bellows-type member 19 in the first section A is chosen so that the lateral stiffness in the first section A is significantly greater than in the second section B despite not having a stiffening element. Therefore, any radial bellows action and/or associated pressure loss over the service life in the first section A is negligible and the steadiness of the rotational speed of the storage element is not negatively affected overall.
[0014] Due to the design of the radial stiffening element 27 according to FIG. 2 , however, the elastomeric bellows-type member 19 in the second section B has increased axial stiffness which, if the section A were not present, would have a negative effect on the ability of the injection valve to operate. In the case of the known actuator types, the output travel actually decreases as the applied counter-force increases. The appropriate design of the axial stiffness in the first section A of the elastomeric bellows-type member 19 , however, ensures that the actuator travel can be introduced into the transmission element 3 with negligible additional counter-force. Since the axial stiffness in the second section B is now no longer relevant to the function of the converter, its chosen value can be arbitrarily high and in particular can be optimal with reference to the requirements described above. The elastomer used in the section A is not strengthened, and its stiffness is set to axial optimum by the hardness of the material and by the geometry. However, as described above, the length of the section A must be chosen so that this section A is stiff enough in the radial direction to bulge only negligibly in the event of an increase in the hydraulic fluid volume.
[0015] In summary therefore, the hydraulic converter 3 and/or the storage element 17 are formed in such a way that on the one hand, due to the lower radial stiffness in the second section B, the additional volume of hydraulic fluid generated by a temperature change is provided without any noticeable increase in pressure, and therefore the dynamic properties of the injection valve change only imperceptibly in the operating temperature range from −40° C. to +150° C. On the other hand, due to the lower axial stiffness in the first section A, the actuator counter-force generated by the storage element 17 is suitably low. In this case the hardness of the elastomeric material is 70 to 85 ShoreA in accordance with DIN 53505 . The stiffness of the elastomeric material is isotropic and therefore, directionally independent. However, due to space restrictions the elastomeric bellows-type member 19 is in the form of a sleeve, with the result that the length of the sleeve is significantly higher than its wall strength.
[0016] The entire elastomeric storage element 17 is produced in a vulcanizing process. For this purpose the head plate and the bottom plate 21 , 23 together with the stiffening element 27 are inserted into a suitable injection mould and the hot material is injected. The cross-linking process takes place at a high temperature and pressure, so that all parts are connected firmly together and can be taken from the injection mould as a compact and sturdy standard component (not shown).
[0017] The travel-transmitting element according to the invention is suitable for use as a hydraulic compensator in different types of injection valves, in particular diesel injection valves or High Pressure Direct Injection (HPDJ) systems. | Disclosed is a travel-transmitting element for an injection valve, comprising a pressure-loaded storage chamber which is filled with a hydraulic fluid and a storage element that is provided with an elastomeric bellows-type member. In order to ensure sufficient steadiness of the rotational speed over the service life, the inventive elastomeric bellows-type member is provided with a stiffening element which ensures constant radial stiffness over the service life at least in some sections thereof. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to a test system of a cable, and in particular, relates to an insulation and/or spark test system of a cable.
A prior cable test system (Japanese Public Notice of patent application No. 37-14502, published Sept. 19, 1962) has a differentiation circuit connected to the end of the cable to be tested, means for applying a high voltage at said end of the cable for discharging at the point where the dielectric strength is weak, a pulse transformer for transmitting a reflected pulse signal at the dielectric weak point of the cable, and means for measuring the interval of the pulse signal for the round trip to the dielectric weak point and displaying the position of the dielectric weak point.
However, the above prior system has the disadvantage that the frequency characteristics of a pulse transformer are not sufficient for transmitting the pulse signal correctly. Therefore, the pulse transformer generates an undesirable overshoot and/or back-swing waveform, which makes the result of the measurement of the distance to the dielectric weak point incorrect.
SUMMARY OF THE INVENTION
It is an object, therefore, of the present invention to overcome the disadvantages and limitations of prior cable test systems by providing a new and improved cable test system.
It is an also an object of the present invention to provide a new and improved method for testing a cable.
The above and other objects are attained by a cable test system comprising a connector for connecting a cable to be tested to the test system, a D.C. high voltage source connected between a terminal of said connector and the ground, a differentiation circuit connected to said terminal, a limiter circuit connected to the output of said differentiation circuit, a pair of pulse amplifiers connected to the output of said limiter circuit, a time counter connected to the outputs of said pulse amplifiers so as to be started and stopped by the outputs of said pulse amplifiers and a display unit connected to the output of said time counter for displaying the distance from said connector to a dielectric weak point of the cable to be tested according to the content of said time counter.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and attendant advantages of the invention will be appreciated as the same become better understood by the accompanying drawings wherein;
FIG. 1 is a block-diagram of the apparatus for testing a cable according to the prior art;
FIG. 2 shows waveforms showing the operation of the apparatus of FIG. 1;
FIG. 3 is a brief block-dirgram of the apparatus for testing a cable according to the present invention, and
FIG. 4 is a detailed circuit diagram of the apparatus for testing a cable according to the present invention
DESCRIPTION OF THE PREFERRED EMBODIMENT
First, the prior test system of a cable will be explained with regard to FIG. 1 for the easy understanding of the present invention. In FIG. 1, the reference numeral 11 is a coaxial cable, the outer conductor 12 of which is grounded. 13 is a D.C. high voltage source, the positive output of which is grounded, and the negative output of which is connected to the inner conductor 14 of the coaxial cable 11. The differentiation circuit 15 having a serial capacitor C and a parallel resistor R is connected between the inner conductor 14 and the end of the primary winding 17 of the pulse transformer 16. The pulse transformer 16 has a pair of secondary windings 18, 19. The uni-directional elements like the diodes 20, 21 are connected at the end of the winding 18 and the other end of the winding 19. The other ends of the diodes 20 and 21 are connected to the inputs of the pulse amplifiers 22 and 23, respectively. Each output of the amplifiers 22 and 23 are connected to the start input and the stop input of the time counter 24, respectively. The output of the time counter 24 is connected to the display unit 25, which displays the distance from the end of the cable to the point A where the dielectric strength is weak.
If there is a dielectric weak portion at A, a discharge occurs at point A between the inner conductor 14 which the negative high voltage is applied to and the outer conductor 12 which is grounded. The surge voltage (FIG. 2(a) generated by the discharge at point A propagates towards the end B of the cable with the propagation speed determined by the characteristics of the cable. The surge voltage which reaches point B is differentiated by the differentiation circuit 15, which generates the positive pulse shown in FIG. 2(b). Said surge voltage is reflected at the end of the cable and propagates back to the cable 11, since the input impedance of the transformer 16 does not match the impedance of the cable, that is, the former is much higher. The reflected pulse whose phase is the same as that of the input pulse reaches point A where the dielectric strength is weak after a duration determined by the propagation speed and the distance from point B to point A. It should be noted that the impedance at point A when the reflected pulse reaches there, is still small or zero since the propagation time of a surge signal is considerably smaller than the duration of the discharge. Accordingly, the reflected pulse is reflected again, and the re-reflected pulse whose phase is opposite to the original reflected pulse propagates to point B (see FIG. 2(c)). When the re-reflected pulse reaches the measure point B, it is differentiated by the differentiation circuit 15, and the negative differentiated pulse shown is FIG. 2(d) is generated. Although the pulse signal goes and comes back between points A and B repetitively, the first two pulses (FIG. 2(b) and FIG. 2(d) are enough for the testing of the cable, since pulse signals reflected more than three times are considerably attenuated.
When the positive pulse is applied to the pulse transformer 16, the first secondary winding 18 provides an output signal to a first pulse amplifier 22 through a forward connected diode 20. The signal induced on the second secondary winding 19 by the positive input pulse is not applied to the second pulse amplifier 23 since the diode 21 is connected so as to prohibit the signal. On the other hand, when the negative pulse is applied to the transformer 16; the second secondary winding 19 provides an output signal to a second pulse amplifier 23 through the diode 21. The negative input pulse does not cause an input signal to be applied to the first pulse amplifier 22.
The time counter 24 starts counting beginning with the output signal from the first pulse amplifier 22, and finishes the same with the output signal from the second pulse amplifier 23. Counting by the time counter 24 is the function of the propagation time, that is to say, the duration (see T in FIG. 2(d)) that the pulse goes and comes back from the measure point B to the point A where the dielectric strength is weak. The result of the counting is applied to the display unit 25 where the distance relating to the duration T/2 is displayed as the length from point B to point A.
However, as mentioned before, a pulse transformer does not have the satisfactory frequency characteristics. Therefore, the undesirable output pulses like an overshoot and/or a backswing appear at the secondary windings 18 and/or 19. These undesirable pulses disturb the correct operation of the pulse amplifiers 22, 23, the time counter 24 and/or the display unit 25. Thus, the measured value sometimes becomes incorrect. Further, since a pulse transformer is expensive, the test system is made expensive, also.
FIG. 3 and FIG. 4 show a brief block-diagram and a detailed circuit diagram of a cable test system according to the present invention, which overcomes the drawbacks of the prior art mentioned above. The feature of FIG. 3 and FIG. 4 is the replacement of the pulse transformer 16 and the diodes 20, 21 in FIG. 1 with the limiter 31 and the inverter 32. The same members in FIG. 3 and FIG. 4 as the members in FIG. 1 have the same reference numerals, and 15a is an arrester and 33 is a connector for connecting a cable to the test system.
In FIGS. 3 and 4, the operation of the voltage source 13 and the differentiation circuit 15 is the same as that in FIG. 1, and a pair of pulses, the first positive pulse (FIG. 2(b)) and the second negative pulse (FIG. 2(d)) are applied to the limiter 31 from the differentiation circuit 15. The amplitude of these pulses are limited within a predetermined value by the limiter 31. The limiter 31 comprises a pair of zenar diodes 31a and 31b connected in series in opposite polarities as shown in FIG. 4, and the arrester 15a connected parallel with the limiter 31 improves the operation of said limiter 31 for an unimaginable high input voltage. The positive pulse from the limiter 31 is amplified and wave-shaped by the first amplifier 22. At this time, the inverter 32 applies a negative pulse to the second amplifier 23, inverting the polarity of the input positive pulse. However, the second amplifier 23 does not operate with the negative input pulse. On the other hand, the negative pulse from the limiter 31 is inverted by the inverter 32 to the positive pulse, which is amplified and wave-shaped by the second amplifier 23. The first amplifier 22 does not, of course, operate with the negative input pulse. The first amplifier 22 applies a start pulse to the time counter 24 and the second amplifier 23 applies a stop pulse to the time counter 24. Thus, the time counter 24 counts the interval T between the start pulse and the stop pulse, and according to the output of the time counter 24, the display unit 25 displays the distance to the dielectric weak point A.
Since the amplifiers 22 and 23 in FIG. 4 have NPN transistors 22a and 23a whose emitters are directly grounded, these transistors 22a and 23a operate with only positive pulses. It is possible to design the inverter 32 so that it operates with only a negative input pulse. For that purpose, all that it needed is an NPN transistor (not shown) attached to the input circuit of the inverter 32. Further, if the second amplifier 23 is designed to operate with only a negative input pulse, the inverter 32 can be omitted. If the positive electrode of the D.C. high voltage source 13 is connected to the inner conductor 14 and the negative electrode of the same is grounded, the negative differentiation pulse appears first and the positive differentiation pulse follows. In that case, the operational characteristics of the amplifiers 22 and 23 must be designed to match with the polarities of the high voltage source, or the connections between the amplifiers 22, 23 and the time counter 24 must be changed to match with the polarities of the high voltage source.
As mentioned above, according to the present invention the input signal to the amplifiers 22 and 23 does not suffer from the undesirable overshoot and/or back-swing. Therefore, the time counter 24 can operate correctly and the distance to the dielectric weak point can be measured correctly. Further, the present invention replaces the pulse-transformer and rectifiers with a limiter 31, which is relatively inexpensive. Therefore, a whole test system can be manufactured at a reasonable price. Further, due to the presence of the limiter circuit, and arrester the whole circuit including the pulse amplifiers, are protected even though a high amplitude of impulse is applied to the circuit.
From the foregoing it will now be apparent that a new and improved cable test system which provides the accurate distance to the dielectric weak point and can be manufactured at a reasonable price, has been found. It should be understood, of course, that the embodiments disclosed are merely illustrative and are not intended to limit the scope of the invention. Reference should be made, therefore, to the appended claims rather than to the specification, as indicating the scope of the invention. | The distance from the end of the cable to the dielectric weak point of said cable is measured by applying a D.C. high voltage to said cable and generating a discharge at the dielectric weak point, obtaining a pair of pulse signals one by differentiating a surge signal generated and the other reflected at said dielectric weak point, limiting the amplitude of said pair of pulse signals, and measuring the interval between said pair of pulse signals. | 6 |
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention generally relates to an automated luminaire, specifically to a light control system in an automated luminaire.
BACKGROUND OF THE INVENTION
[0002] Luminaires with automated and remotely controllable functionality are well known in the entertainment and architectural lighting markets. Such products are commonly used in theatres, television studios, concerts, theme parks, night clubs and other venues. A typical product will commonly provide control over the pan and tilt functions of the luminaire allowing the operator to control the direction the luminaire is pointing and thus the position of the light beam on the stage or in the studio. Typically this position control is done via control of the luminaire's position in two orthogonal rotational axes usually referred to as pan and tilt. Many products provide control over other parameters such as the intensity, color, focus, beam size, beam shape and beam pattern. The beam pattern is often provided by a stencil or slide called a gobo which may be a steel, aluminum or etched glass pattern. The products manufactured by Robe Show Lighting such as the Robin MMX Spot are typical of the art.
[0003] The optical systems of such automated luminaires may be designed such that a very narrow output beam is produced so that the units may be used with long throws or for almost parallel light laser like effects. These optics are often called ‘Beam’ optics. To form this narrow beam with the large light sources in the prior art the output lens either needed to be very large with a large separation between the lens and the gobos or of a short focal length and much closer to the gobos. It is problematic to use a large separation with a large lens as such an arrangement makes the luminaire large and unwieldy and makes automation of the pan and tilt movement difficult. Thus the normal solution is a closer and smaller lens with a short focal length. Alternatively the thick heavy front lens may be replaced with a Fresnel lens where the same focal length is achieved with a much lighter molded glass lens using multiple circumferential facets. Fresnel lenses are well known in the art and can provide a good match to the focal length of an equivalent plano-convex lens, however the image projected by such a lens is typically soft edged and fuzzy and not a sharp image as may be desired when projecting gobos or patterns.
[0004] FIG. 1 illustrates a multiparameter automated luminaire system 10 . These systems commonly include a plurality of multiparameter automated luminaires 12 which typically each contain on-board a light source (not shown), light modulation devices, electric motors coupled to mechanical drives systems and control electronics (not shown). In addition to being connected to mains power either directly or through a power distribution system (not shown), each luminaire is connected is series or in parallel to data link 14 to one or more control desks 15 . The luminaire system 10 is typically controlled by an operator through the control desk 15 . Control of the automated luminaire 12 is effectuated by electromechanical devices within the luminaire 12 and electronic circuitry 13 including firmware and software within the control desk 15 and/or the luminaire 12 . In many of the figures herein, important parts like electromechanical components such as motors and electronic circuitry including software and firmware and some hardware are not shown in order to simplify the drawings so as to teach how to practice the inventions taught herein. Persons of skill in the art will recognize the need for these parts and should be able to readily fill in these parts.
[0005] FIG. 2 illustrates a prior art automated luminaire 12 . A lamp 21 contains a light source 22 which emits light. The light is reflected and controlled by reflector 20 through a hot mirror 23 , aperture or imaging gate 24 , and optical devices 25 , 27 which may include dichroic color filters, effects glass and other optical devices well known in the art. Optical components 27 are the imaging components and may include gobos, rotating gobos, iris and framing shutters. The final output beam may be transmitted through focusing lens 28 and output lens 29 . Lens 29 may be a short focal length glass lens or equivalent Fresnel lens as described herein. Either optical components 27 , lens 28 , or lens 31 may be moved backwards and forwards along the optical axis to provide focus and/or beam angle adjustment for the imaging components. Hot mirror 23 is required to protect the optical systems 25 and 27 from high infra-red energy in the light beam and typically comprises a glass plate with a thin film dichroic coating designed to reflect long wavelength infra-red light radiation and only allow the shorter wavelength, visible, light to pass through and into the optical system.
[0006] More recently lamps 21 with extremely small light sources 22 have been developed. These often use a very short arc gap, of the order of 1 mm, between two electrodes as the light producing means. These lamps are ideal for producing a very narrow beam as their source etendue is low, and the size of the lenses and optical systems to collimate the light from such a small source can be substantially reduced. However, the short arc and small light source coupled with the short focal length, and thus large light beam angles, of the reflector also tend to produce substantial amounts of unwanted and objectionable spill light which can escape between gobos or around the dimming shutters.
[0007] There is a, increased need for an improved light control system for an automated luminaire utilizing a light source with an intense hotspot such that light spill around or between gobos and/or through the dimming shutter is reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings in which like reference numerals indicate like features and wherein:
[0009] FIG. 1 illustrates a typical automated lighting system;
[0010] FIG. 2 illustrates a prior art automated luminaire;
[0011] FIG. 3 illustrates an embodiment of an improved light engine for automated luminaires with high hot spot, non even beam profiles and gobos;
[0012] FIG. 4 illustrates an isometric view of an embodiment illustrated in FIG. 3 ;
[0013] FIG. 5 illustrates an isometric view of the embodiment illustrated in FIG. 3 ;
[0014] FIG. 6 illustrates a view of the static gobo wheel of an embodiment illustrated in FIG. 3 ;
[0015] FIG. 7 illustrates a view of the rotating gobo wheel of an embodiment illustrated in FIG. 3 ;
[0016] FIG. 8 illustrates an embodiment of a logic flow chart of the control of the light control system where the aperture size is automatically selected based on selections of the rotating and static gobos; and
[0017] FIG. 9 illustrates an embodiment of a logic flow chart of the control of the light control system during a mechanical blockout.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Preferred embodiments of the present invention are illustrated in the FIGUREs, like numerals being used to refer to like and corresponding parts of the various drawings.
[0019] The present invention generally relates to an automated luminaire, specifically to the design and operation of a light control system for use within the automated luminaire utilizing a light source with an intense hotspot such light spill around or between gobos and/or through the dimming shutter is reduced.
[0020] FIG. 3 illustrates an embodiment of the invention. The automated luminaire contains a light source 32 within reflector 30 . Light source 32 may be a short arc discharge lamp with arc length of approximately 1 mm, and reflector 30 may be an ellipsoidal glass reflector. The combination of a short arc light source and an ellipsoidal reflector is well known in the art and produces a light beam towards the second focus of the ellipsoidal reflector. Such a beam typically has a very high energy beam center, or hotspot, which can be damaging to downstream optics and also produces a poor wide beam pattern when trying to use the luminaire as a wash light. The light beam passes through the heat protection and homogenization system 34 before passing through optical systems such as, for example, color system 36 , static gobo system 37 , and rotating gobo system 38 . The light beam then continues through lenses 40 , 42 , and 44 which may each individually or cooperatively be capable of movement along optical axis 46 so as to alter the focus and beam angle or zoom of the light beam.
[0021] Because of the short focal length of the lamp 32 and reflector 30 the light beam passing through the static gobo wheel 37 , and rotating gobo wheel 38 is sharply diverging, far from a parallel beam. This diverging beam provides increased possibility for light spill through one gobo on the first wheel past the edges of another gobo on the second wheel. FIG. 4 illustrates a perspective view of an embodiment of the invention which more clearly shows the gobo wheels providing the light control system. The light control system utilizes coordinated control of the static gobo wheel 37 and rotating gobo wheel 38 in order to minimize light spill.
[0022] FIG. 5 illustrates a further perspective view of an embodiment of the invention which more clearly shows the dimmer shutter 49 as well as the static gobo wheel 37 and rotating gobo wheel 38 .
[0023] FIGS. 6 and 7 illustrate detailed views of the static gobo wheel 37 and rotating gobo wheel 38 . Static gobo wheel 37 contains a plurality of patterns or gobos such as 58 and 60 . It further contains a range of sizes of circular apertures including large aperture 56 and medium aperture 54 . Similarly rotating gobo wheel 38 contains a plurality of patterns or gobos such as 52 each of which may be rotated about its central axis. It also contains a full aperture 50 with no pattern or gobo, usually called the open hole.
[0024] In operation the light control system coordinates the use of the full 56 and medium sized 54 apertures on the fixed gobo wheel 37 with the movement of the rotating gobo wheel 38 in order to minimize light spill. If the user is only utilizing the fixed gobo wheel 37 and the rotating gobo wheel 38 is positioned such that the open hole 50 is across the light path, then the system will utilize the medium aperture 54 as being the open hole for that wheel. In such case the large aperture 56 cannot be selected by the user and the system will avoid it when the wheel is rotated. The use of the medium aperture 54 instead of the large aperture 56 avoids excessive light spill from the large aperture 56 which could create haloes and patterns in the light beam. However, as soon as the user selects any gobo on rotating gobo wheel 38 other than the open hole 50 , such as gobo 52 , then the static gobo wheel 37 will automatically rotate from the medium aperture 54 to the large aperture 56 as its open hole. The use of the large aperture 56 on static gobo wheel in conjunction with any gobo other than the open aperture on the rotating gobo wheel results in improved light output through the rotating gobo wheel and, because a rotating gobo is in place, the risk of light spill is minimized.
[0025] FIG. 8 shows the flow chart which clarifies the algorithm by which the software in the automated light will determine the relative automatic movements of the static gobo wheel 37 and rotating gobo wheel 38 to use the appropriate sized aperture as the open hole on the fixed gobo wheel 37 . Such a system provides an advantage to the user in that it maximizes the light output from the system when using rotating gobos while minimizing light spill at all times, with any combination of static and rotating gobos.
[0026] If other than open hole is selected on the rotating gobo wheel 71 and other than open hole is selected on the fixed wheel 75 , then the fixed wheel position is retained 77 and the inquiry repeats at 71 .
[0027] If other than open hole is selected on the rotating gobo wheel 71 and there is no selection other than open hole on the fixed wheel 75 , then the large size aperture on the fixed wheel is automatically selected 76 and the inquiry repeats at 71 .
[0028] If there is no other than open hole selected on the rotating gobo wheel 71 and other than open hole is selected on the fixed wheel 72 , then the fixed wheel position is retained 74 and the inquiry repeats at 71 .
[0029] If there is no other than open hole selected on the rotating gobo wheel 71 and there is no selection other than open hole on the fixed wheel 72 , then the medium size aperture on the fixed wheel is automatically selected 73 and the inquiry repeats at 71 .
[0030] In a further embodiment of the invention the light control system makes further use of the static gobo wheel 37 to minimize light spill from the luminaire when it is dimmed to blackout. The discharge lamps used in automated luminaires such as lamp 32 shown herein cannot typically be electrically dimmed to a full blackout. Enough current has to be left running to maintain the arc discharge. Thus, to obtain a full blackout of the luminaire, a secondary dimming or shutter system such as 49 must be provided. These systems are typically mechanical utilizing blades, shutters, iris diaphragms or similar devices well known in the art to selectively restrict light from the optical system thus dimming it. At the extreme position of such a mechanical dimmer the shutter or blade may be completely across the light beam. However, with the short arc, short focal length lamps described herein, extreme angle light may still be able to escape through or around the dimmer system resulting in objectionable ghosting of stray light and an incomplete blackout. The light control system described recognizes when the mechanical dimmer is in its minimum, or blackout, position and automatically moves the static gobo wheel 37 to the nearest position intermediate between two patterns or gobos thus providing a secondary block to stray light. For example, as shown in FIG. 6 , if the static gobo wheel is in position such that gobo 58 is being used and is across the light beam and the user issues the command to black out the luminaire, then the light control system will automatically move static gobo wheel 37 to position 62 that is intermediate between gobos 58 and 60 . This is a position where no light can pass through the wheel so that it provides a secondary block to spill light. Similarly, for any other position on the static gobo wheel 37 , on receiving the blackout command the wheel will rotate one half of a step to the closest intermediate position between two gobos. This small rotation may happen very quickly and is not noticeable to the user or the audience. Upon opening the dimmer again and coming out of blackout, the static gobo wheel 37 will return to its original position.
[0031] FIG. 9 illustrates an embodiment of a logic flow chart of the control of the light control system during a mechanical blackout. If the mechanical dimmer is in a blackout position 82 and the fixed wheel is in the large aperture position 84 , then the fixed wheel is moved 1 and ½ positions 90 so it is between gobo positions and the inquiry repeats.
[0032] If the mechanical dimmer is in a blackout position 82 and the fixed wheel is not in the large aperture position 84 , then (1) if the fixed wheel is between positions 86 then the inquiry repeats (2) if the fixed wheel is not between positions 86 then the fixed wheel is moved ½ position 88 so it is between gobo positions and the inquiry repeats.
[0033] If the mechanical dimmer is NOT in a blackout position 82 and the fixed wheel is NOT between gobo positions 92 the inquiry repeats.
[0034] If the mechanical dimmer is NOT in a blackout position 82 and the fixed wheel is between gobo positions 92 then the fixed wheel is returned to the last user or automatically selected hole position 94 and the inquiry repeats.
[0035] While the disclosure has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the disclosure as disclosed herein. The disclosure has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the disclosure. | Automatic light control system for a Luminaire with a light source and beam forming light collector with and intense hotspot. The Luminaire automatically selects a large aperture when a gobo is selected. When no gobo is selected then a medium aperture is automatically selected. In some embodiments these selections can be overridden. In some embodiments the large and medium aperture are on a non-glass gobo wheel. In further embodiments, when blackout is selected, this wheel automatically advances ½ position or 1 and ½ position so as to support a blackout state of the fixture until a non-blackout condition is selected. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The subject matter of the present application is related to U.S. patent application Ser. No. ______, attorney docket number AUS920030090US1, and U.S. patent application Ser. No. ______, attorney docket number AUS920030093, incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention is related generally to the organization of financial accounts. Specifically, the present invention is directed towards a method of managing smartcard applications.
BACKGROUND OF THE INVENTION
[0003] The use of credit cards in consumer transactions is well known in the art. A credit card is defined as an account card issued by a specific bank or financial institution for the purpose of purchasing goods and services on credit provided by the bank or financial institution. Credit cards typically have a preset spending limit and specific terms regarding payment terms, interest rates, grace periods, and other terms and conditions. However, the credit card itself does not contain any information other than the account number. In order to complete a transaction, the credit card account number is read from the card, sent to the bank or financial institution for verification of account and charge authorization, and returned to the vendor with approval for the transaction to proceed. The transaction process can be time consuming when the transaction occurs during peak purchasing periods or when the transaction takes place in a foreign country. The transaction may be stopped entirely if the vendor is unable to establish communications with the bank. Moreover, credit cards apply to a single account. In other words, the bank or financial institution must issue one credit card to the consumer for every account, requiring the consumer to carry multiple credit cards when the consumer has more than one account. Therefore, a need exists for a credit card that can be used for multiple accounts.
[0004] Debit cards are also well known in the art. With a debit card the consumer spends money already deposited in an account, rather than creating a credit account that will be paid at some later time. Debit cards are frequently used with deposit accounts such as checking, savings, and money market accounts. Unfortunately, like credit cards, debit cards card only contain a single account number. The vendor must still authorize the transaction through a communications network in order for the transaction to proceed, and the debit card can only be used for transactions with a single account. Therefore, a need exists for a debit card that can be used for multiple accounts.
[0005] A smartcard is one solution to the problems encountered with traditional credit and debit cards. A smartcard is a card, sized similarly to a credit card, which contains a processor and a memory. A smartcard is more advantageous than a credit card in that the smartcard can store and update account information within the smartcard memory. Storing and updating the account information within the smartcard memory is advantageous because charge authorization can be obtained directly from the card itself rather than through communications with the bank or financial institution. Moreover, because the smartcard has the ability to store and update information, one smartcard can contain information regarding a plurality of accounts. The ability of the smartcard to store account information on a plurality of accounts eliminates the need for the consumer to carry a plurality of cards. Instead, the consumer can carry one smartcard that contains account information for the user's checking, savings, money market, and credit accounts.
[0006] Moreover, smartcards contain additional flexibility because a user can add various applications onto their smartcard. One example of an application for a smartcard is a health care application. In a health care application, a smartcard may contain the user's heath insurance information so that the user's doctor can scan the smartcard and receive the patient's updated medical and insurance information, thereby streamlining the information exchange between the doctor, the patient, and the insurer. A similar application can be added to the smartcard for prescription drugs so that the doctor can use the card to know the status of the user's prescriptions.
[0007] Another example of an application is an airline frequent flyer application. In the frequent flyer application, the smartcard contains the user's frequent flyer information such as the account number, mileage balance, status level, and so forth. When the user purchases air travel with the smartcard, the frequent flyer information is automatically connected to the travel information, streamlining the exchange of information between the user and the airline.
[0008] However, the combination of a plurality of accounts and applications on a single smartcard creates new problems that were not previously encountered with credit or debit cards. One of these problems is efficient organization and maintenance of the accounts and applications on the smartcard. Smartcard users need to be able to add, modify, update, and delete accounts and applications as needed. Therefore, a need exists for an efficient method of organizing and maintaining accounts and applications associated with a smartcard.
[0009] The problem of smartcard management has been addressed by the prior art. U.S. Pat. No. 5,544,246 (the '246 patent) entitled “Smartcard Adapted for a Plurality of Service Providers and for Remote Installation of Same” discloses a method of organizing and limiting access to the files installed within a smartcard. U.S. Pat. No. 6,199,762 B1 (the '762 patent) entitled “Methods and Apparatus for Dynamic Smartcard Synchronization and Personalization” discloses an account maintenance system for a smartcard. What is needed beyond the '246 patent and the '762 patent is a method for organizing a plurality of accounts and applications associated with a smartcard.
[0010] Consequently, a need exists in the art for a method for organizing accounts and applications associated with a smartcard. Furthermore, a need exists for a method for adding, deleting, updating, and modifying accounts and applications associated with a smartcard. The need extends to an apparatus for implementing the aforementioned methods.
SUMMARY OF THE INVENTION
[0011] The present invention, which meets the needs identified above, is a method and apparatus for managing applications installed on a smartcard. The present invention can be embodied in a software program operable on a computer. In the software embodiment, the invention comprises a Smartcard Management Program (SMP), a User Action Program (UAP), a User Command Program (UCP), an Application Status Update Program (ASUP), and a Card Status Update Program (CSUP). The SMP interfaces with smartcard communications system and accepts the user commands. The UAP obtains applications from external sources, updates the user profile, and transmits the user profile to the user for viewing on a graphical user interface (GUI).
[0012] The UCP breaks the user commands into card actions and application actions and executes the card actions and application actions. Possible card actions include updating the PIN. Possible application actions include adding, installing, personalizing, updating, and deleting an application.
[0013] The ASUP updates the user profile by changing the entry in an application name column, an application status column, a user action column, and an information column. Possible application states include without limitation: new, downloaded, installed, ready, update available, blocked, unblocked and personalized. An application is new when the application is available to the user. An application is downloaded when the user has downloaded the compressed data file for the application to the smartcard. An application is installed when the user has installed the compressed data file. An application is personalized when it has been properly set up by the user, possibly including registration. An application is ready when it is ready to be used. An application has an update available when there is a downloadable update available for the application. An application is blocked when the application issuer or the smartcard issuer has temporarily blocked the application. An application issuer or smart card issuer can also unblock an application.
[0014] The CSUP updates the user profile by changing the entry in the card status field. Possible card states include without limitation: terminated, updated PIN, and locked. The card is terminated when the smartcard issuer blocks all activity on the smartcard, such as when the smartcard is lost or stolen. The PIN needs to be updated when the smartcard issuer resets the PIN, possibly for security reasons. The card is locked when the smartcard issuer wants to temporarily block activity on the smartcard, possibly to affirm that the activity on the card is not fraudulent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0016] FIG. 1 is an illustration of the communications system associated with a smartcard;
[0017] FIG. 2 is an illustration of the flow of information between the smartcard, the chip management system (CMS), and the client card system (CCS);
[0018] FIG. 3 is an illustration of the flow of information between the smartcard user, the CMS, an external server, and the CSS;
[0019] FIG. 4 is an illustration of a computer memory containing the computer program embodiment of the present invention;
[0020] FIG. 5 is a flowchart of the logic of the Smartcard Management Program (SMP) of the present invention;
[0021] FIG. 6 is a flowchart of the logic of the User Action Program (UAP) of the present invention;
[0022] FIG. 7 is a flowchart of the logic of the User Command Program (UCP) of the present invention;
[0023] FIG. 8 is a flowchart of the Application Status Update Program (ASUP) of the present invention;
[0024] FIG. 9 is a flowchart of the Card Status Update Program (CSUP) of the present invention; and
[0025] FIG. 10 is an illustration of the display of the graphical user interface (GUI) on the CSS associated with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] “Application issuer” shall have the same meaning herein as the term “Application Provider” (AP).
[0027] “Chip” means a processor and a memory contained within a smart card wherein the processor is connected to the memory and is capable of wired or wireless communication with a card reader or card reader/writer.
[0028] “Chip Information Number” (CIN) means a unique number assigned to each individual chip. The CIN can be used to identify the correct smartcard user when used in conjunction with a PIN.
[0029] “Chip Management System” (CMS) means a system that manages the lifecycle of the chip including without limitation storage and management of a card profile associated with a chipholder.
[0030] “Client Card System” means a computer having an interface for communication with a smart card.
[0031] “Computer” means a machine having a processor, a memory, and an operating system, capable of interaction with a user or other computer, and shall include without limitation: desktop computers, notebook computers, servers, personal digital assistants (PDAs), handheld computers, and cell phones.
[0032] “Display” means a visual depiction of a web page or computer program on a graphical user interface (GUI).
[0033] “Distribution Server” (DS) means a server that is a trusted node to the CMS that can obtain the chipholder profile from the CMS and package information from the chipholder profile into Application Protocol Data Units (APDU). The DS has an Intelligent Gateway mode where the user is directly interfacing with the server or a router mode where another device such as an automatic teller machine (ATM) is performing the interaction with the user.
[0034] “Input device” means a keyboard, mouse, trackball, touchpad, touchpoint device, stylus pen, touch screen, or any other type of device used to input data into a computer.
[0035] “Post-issuance data” means instructions and data for adding, modifying, or deleting data stored in a chip. One type of post issuance data is a user profile.
[0036] “Personal Information Number” (PIN) means a unique number assigned to each individual smartcard. The PIN can be used to identify the correct smartcard user when used in conjunction with a CIN.
[0037] “Security Server” (SS) means a server that provides for secure transmission of data from the CMS to the DS.
[0038] “Smartcard” means a card used for personal or business transactions comprising at least a processor and a memory capable of supporting an operating system application programs, storage of chip holder personalization data, application data and other data as may be required by the issuer of a smart card.
[0039] “User interaction” means activating a button on a display by clicking on the button with a user input device or by touching the screen with a human hand or object; or activating a menu item on a display by clicking on the item with a user input device or by touching the screen with a human hand or object.
[0040] FIG. 1 is a diagram of one embodiment of a system 20 for carrying out operations associated with and providing post-issuance data to smartcard 32 . Smartcard 32 is shown inserted into client card system (CSS) 30 . CSS 30 may be, for example, a point-of-sale terminal, an automatic teller machine (ATM), or similar device. In general, smartcard 32 is capable of communicating with CSS 32 . For example, smartcard 32 may have a set of electrically conductive contacts arranged on a surface, and CSS 30 may have a similarly arranged set of electrically conductive contacts located in a smart card interface. When smartcard 32 is inserted into CSS 30 , corresponding members of the two sets of contacts may come into physical contact with one another. In addition, smartcard 32 is preferably capable of establishing and carrying out secure communications with CSS 30 as described in U.S. patent application Ser. No. ______ (attorney docket number AUS920030090).
[0041] In addition to CSS 30 and smartcard 32 , system 20 also includes chip management system (CMS) 22 , security server (SS) 24 , distribution server (DS) 28 , and communication network 26 . As indicated in FIG. 1 , CSS 30 , CMS 22 , SS 24 , and DS 28 are connected to communication network 26 . Communication network 26 includes, without limitation, the public switched telephone network (PSTN) and/or the Internet. CSS 30 , CMS 22 , SS 24 , and DS 28 communicate with one another via communication network 26 to convey post-issuance data to smartcard 32 via a secure communication channel established within communication network 26 .
[0042] One type of post-issuance data is the user profile described herein. FIG. 2 is an illustration of the process of CSS 30 obtaining user profile 40 from CMS 22 . FIG. 2 is best understood when viewed in conjunction with Smartcard Management Program (SMP) 100 in FIG. 5 . When smartcard 32 is inserted into CSS 30 , CSS 30 reads CIN 34 from smartcard 32 . CSS 30 then transmits CIN 34 to CMS 22 . CMS 22 uses CIN 34 to access the user's profile 40 . CMS 40 then transmits user profile 40 back to CSS 30 , where CSS 30 displays user profile 40 on graphical user interface (GUI) 42 . Display 600 in FIG. 10 is one possible illustration of the display of GUL 42 .
[0043] As part of the present invention, the smartcard user can modify his user profile from any CSS. FIG. 3 is an illustration of the process of a user 46 modifying his user profile 40 . FIG. 2 is best understood when viewed in conjunction with User Action Program (UAP) 200 in FIG. 6 . User 46 views his user profile on GUI 42 . User 46 then performs a user action on a input device 44 . CSS 30 transforms the user action into an electronic user command and transmits the user command to CMS 22 . CMS 22 uses the user command to modify user profile 40 . If necessary, CMS 22 can send a request to external server 48 and external server 48 will send an application, an update, or similar data back to CMS 22 . CMS 22 then sends the updated user profile back to CSS 30 , where CSS 30 displays the updated user profile on GUI 42 . This process illustrated in FIG. 3 ends when smartcard 32 is removed into CSS 30 or user 46 terminates the process by input into input device 44 . Alternatively, the user profile can be installed on the smartcard and updates sent to a user profile archive in the CMS.
[0044] The internal configuration of a computer, including connection and orientation of the processor, memory, and input/output devices, is well known in the art. The present invention is a methodology that can be embodied in a computer program. Referring to FIG. 4 , the methodology of the present invention is implemented on software by Smartcard Management Program (SNP) 100 . SMP 100 comprises User Action Program (UAP) 200 , User Command Program (UCP) 300 , Application Status Update Program (ASUP) 400 , and Card Status Update Program (CSUP) 500 . SMP 100 , UAP 200 , UCP 300 , ASUP 400 , and CSLTP 500 described herein can be stored within the memory of a computer on CMS 22 , SS 24 , DS 28 , or the CSS 30 depicted in FIGS. 1 , 2 , and 3 . Alternatively, SMP 100 , UAP 200 , UCP 300 , ASUP 400 , and/or CSUP 500 can be stored in an external storage device such as a removable disk or a CD-ROM. Memory 98 is illustrative of the memory within CMS 22 of FIGS. 1 , 2 , and 3 . Memory 92 also contains user profile 40 . The present invention may interface with user profile 40 through memory 98 . As part of the present invention, the memory 98 can be configured with SMP 100 , UAP 200 , UCP 300 , ASUP 400 , and/or CSUP 500 .
[0045] In alternative embodiments, SMP 100 , UAP 200 , UCP 300 , ASUP 400 , and/or CSUP 500 can be stored in the memory of other computers. This configuration allows the processor workload to be distributed across a plurality of processors instead of a single processor. Further configurations of SMP 100 , UAP 200 , UCP 300 , ASUP 400 , and/or CSUP 500 across various memories are known by persons skilled in the art.
[0046] Turning to FIG. 5 , a flowchart of the logic of SMP 100 is illustrated. SMP 100 is a program which runs while the smartcard is inserted into a CSS. SMP 100 starts ( 102 ) when the user inserts the smartcard into the CSS ( 104 ). Generally, the user must enter his PIN on the input device on the CSS in conjunction with inserting the smartcard into the CSS. The CSS then reads the CIN from the smartcard and transmits the CIN to the CMS ( 106 ). The CMS then uses the CIN to access the user profile ( 108 ). The CMS then transmits the user profile back to the CSS ( 110 ). The CSS then displays the user profile on the GUI ( 112 ). SMP 100 then makes a determination whether there is a user command ( 114 ). If there is a user command, SMP 100 runs UAP 200 ( 116 ) and returns to step 114 . If at step 114 there is not a user command (i.e. the user has removed his smartcard from the CSS), SMP 100 ends ( 118 ).
[0047] Turning to FIG. 6 , a flowchart of the logic of UAP 200 is illustrated. UAP 200 starts ( 202 ) when prompted by SMP 100 . UAP 200 accepts the user command entered in SMP 100 ( 204 ) and directs the CSS to transmit the user command to the CMS ( 206 ). UAP 200 then makes a determination whether an application is available from an external source ( 208 ). If an application is available from an external source, UAP 200 obtains the application from the external source ( 210 ) and proceeds to step 212 . If at step 208 an application is not available from an external source, UAP 200 proceeds directly to step 212 . At step 212 , UAP 200 runs UCP 300 ( 212 ). UAP 200 then runs ASUP 400 ( 214 ) and CSUP 500 ( 216 ). UAP 200 then directs the CMS to send the updated user profile to the CSS ( 218 ). The CSS then displays the updated user profile on the GUI ( 220 ). UAP 200 then ends ( 222 ).
[0048] Turning to FIG. 7 , a flowchart of the logic of UCP 300 is illustrated. UCP 300 starts ( 302 ) when prompted by UAP 200 . UCP 300 accepts the user command entered in SMP 100 ( 304 ). UCP 300 then makes a determination whether the user command is a card action or an application action ( 306 ). In other words, UCP 300 classifies user commands into commands concerning applications installed on the card and commands concerning the smartcard itself. If the command is a card action, then UCP 300 makes a determination whether the card action is a user command to update the PIN ( 308 ). If the user does not want to update the PIN, UCP 300 returns to step 306 . If the user wants to update the PIN, the UCP 300 allows the user to update the PIN ( 310 ) and proceeds to step 332 . Persons skilled in the art are aware of other card actions in addition to updating a PIN.
[0049] Returning to step 306 , if the user command is an application action, then UCP 300 proceeds to step 312 where UCP 300 makes a determination whether the user command is to add an application ( 312 ). If the user command is to add an application, then UCP 300 adds the application to the user profile ( 314 ) and proceeds to step 332 . In adding the application to the user profile, UCP 300 downloads the compressed application data file to the user profile and/or smartcard and adds the application name to the application name column (see FIG. 10 ). Returning to step 312 , if the user does not want to add an application, UCP 300 proceeds to step 316 where UCP 300 makes a determination whether the user command is to install an application ( 316 ). If the user command is to install an application, UCP 300 installs the application ( 318 ) and proceeds to step 332 . In installing the application, UCP 300 decompresses the compressed application data file and runs the install program associated with the application. Returning to step 316 , if the user does not want to install an application, USP 300 proceeds to step 320 where UCP 300 makes a determination whether the user command is to personalize an application ( 320 ). If the user wants to personalize an application, then UCP 300 personalizes the application selected by the user ( 322 ) and proceeds to step 332 . In personalizing the application, the user adds any necessary or optional data to the application to place the application in a state to perform a task. Personalizing an application can include registering the application.
[0050] Returning to step 320 , if the user does not want to personalize the application, then UCP 300 makes a determination whether the user command is to update an application ( 324 ). If the user wants to update an application, then UCP 300 downloads the update from the applicable location, installs the update ( 326 ), and proceeds to step 332 . Returning to step 324 , if the user does not want to update the application, UCP 300 makes a determination whether the user wants to delete the application ( 328 ). If the user does not want to delete the application, UCP 300 returns to step 312 . If the user wants to delete the application, UCP 300 deletes the application from the user profile ( 330 ) and proceeds to step 332 . In deleting the application, UCP 300 removes the application from the user profile and/or the smartcard. Persons skilled in the art are aware of how to add, install, personalize, update, and delete an application from a smartcard and/or user profile. Persons skilled in the art are also aware of other application actions besides the ones described in steps 312 through 330 . UCP 300 then updates the user profile ( 332 ) and ends ( 334 ).
[0051] Turning to FIG. 8 , a flowchart of the logic of ASUP 400 is illustrated. ASUP 400 starts ( 402 ) when prompted by UAP 200 . ASUP 400 uses the CIN to access the user profile ( 404 ). ASUP 400 then makes a determination whether there are any applications that can be installed on the user profile which are not already installed ( 406 ). If there are not any applications that can be installed on the user profile, ASUP 400 proceeds directly to step 414 . If there are applications which can be installed, ASUP 400 adds the application name column of the user profile (see FIG. 10 ) ( 408 ). ASUP 400 then adds the “new” icon to the application status column (see FIG. 10 ) ( 410 ). ASUP 400 then adds the “download” button to the user actions column (see FIG. 10 ) ( 412 ). ASUP 400 then proceeds to step 414 .
[0052] At step 414 , ASUP 400 makes a determination whether any applications are saved on the user profile ( 414 ). If there are not any applications saved on the user profile, ASUP 400 proceeds to step 454 . If there are applications saved on the user profile, ASUP 400 goes to the first application and makes a determination whether the application is downloaded ( 416 ). If the application is downloaded, ASUP 400 removes the “new” icon from the application status column and adds the “downloaded” icon to the application status column ( 418 ). ASUP 400 then removes the “download” button from the user action column and adds the “install” and “delete” buttons to the user action column ( 420 ). ASUP 400 then proceeds to step 422 .
[0053] Returning to step 416 , if the application is not downloaded, then ASUP 400 proceeds to step 422 where ASUP 400 makes a determination whether the application is installed ( 422 ). If the application is installed, ASUP 400 removes the “downloaded” icon from the application status column and adds the “installed” icon to the application status column ( 424 ). ASUP 400 then removes the “install” button from the user action column and adds the “personalize” button to the user action column ( 426 ). ASUP 400 then proceeds to step 428 .
[0054] Returning to step 422 , if the application is not installed, then ASUP 400 proceeds to step 428 where ASUP 400 makes a determination whether the application is personalized ( 428 ). If the application is personalized, ASUP 400 removes the “installed” icon from the application status column and adds the “ready” icon to the application status column ( 430 ). ASUP 400 then removes the “personalize” button from the user action column ( 432 ). ASUP 400 then proceeds to step 434 .
[0055] Returning to step 428 , if the application is not personalized, then ASUP 400 proceeds to step 434 where ASUP 400 makes a determination whether an update for the application is available ( 434 ). If an update for the application is available, ASUP 400 adds the “update available” icon to the application status column ( 436 ). ASUP 400 then adds the “update” button to the user action column ( 438 ). ASUP 400 then proceeds to step 440 .
[0056] Returning to step 434 , if an update for the application is not available, ASUP 400 proceeds to step 440 where ASUP 400 makes a determination whether the application is blocked ( 440 ). An application is blocked if the application issuer has stopped the user from using the particular application. Persons skilled in the art are aware of how to block an application on a smartcard. If the application is blocked, ASUP 400 adds the “blocked” icon to the application status column ( 442 ). ASUP 400 then hides the buttons in the user action column ( 444 ). ASUP 400 then proceeds to step 450 .
[0057] Returning to step 440 , if the application is not blocked, ASUP 400 proceeds to step 446 where ASUP 400 makes a determination whether the “blocked” icon is in the application status column ( 446 ). If the “blocked” icon is not in the application status column, ASUP 400 proceeds to step 450 . If the “blocked” icon is in the application status column, ASUP 400 removes the “blocked” icon from the application status column and displays the user action buttons ( 448 ). ASUP 400 then proceeds to step 450 .
[0058] At step 450 , ASUP 400 makes a determination whether there is another application on the user profile ( 450 ). If there is another application on the user profile, ASUP 400 goes to the next application ( 452 ) and returns to step 416 . If at step 450 there is not another application, ASUP 400 updates the user profile ( 454 ) and ends ( 456 ).
[0059] Turning to FIG. 9 , a flowchart of the logic of CSUP 500 is illustrated. CSUP 500 starts ( 502 ) when prompted by UAP 200 . CSUP 500 then uses the CIN to access the user profile ( 504 ). CSUP 500 then makes a determination whether the smartcard has been terminated ( 506 ). A smartcard has been terminated if the smartcard issuer has blocked all activity on the smartcard. A smartcard may be terminated if the smartcard is lost or stolen. Persons skilled in the art are aware of how to terminate a smartcard. If the smartcard has been terminated, CSUP 500 changes the card status to “card terminated” ( 508 ) and proceeds to step 520 . If at step 506 the card has not been terminated, CSUP 500 makes a determination whether the PIN has been reset ( 510 ). A PIN has been reset when the smartcard issuer deletes an old PIN and requests that the user set a new PIN. Persons skilled in the art are aware of how to reset a PIN. If the PIN has been reset, CSUP 500 changes the card status to “update PIN” ( 512 ) and proceeds to step 520 . If at step 510 the PIN has not been reset, CSUP 500 makes a determination whether the card is locked ( 514 ). A card is locked if the smartcard issuer wants to temporarily block the use of the card, but not terminate the card. Persons skilled in the art are aware of how to lock a smartcard. If the card is locked, CSUP 500 changes the card status to “card locked—call customer service for more information” ( 516 ) and proceeds to step 520 . If at step 514 the card is not locked, CSUP 500 changes the card status to “ready” ( 518 ) and proceeds to step 520 . At step 520 , CSUP 500 updates the user profile ( 520 ) and ends ( 522 ).
[0060] FIG. 10 is one possible display 600 from GUI 42 depicted in FIGS. 2 and 3 . Display 600 depicts the card status 602 , which is modified by CSUP 500 in FIG. 9 . Display 600 also depicts numerous applications 604 which can be modified by UCP 300 depicted in FIG. 7 and ASUP 400 depicted in FIG. 8 . ASUP 400 makes reference to application name column 606 , application status column 608 , user action column 610 , all of which are depicted in display 600 . Display 600 also contains information column 612 which displays any additional information related to a particular application 604 .
[0061] While the disclosed application for the present invention is within smartcards, this disclosure is not meant to be limiting in any way. The present invention can be alternatively embodied in wireless devices, home appliances, and the like. In fact, the present invention is advantageous whenever there is a need to organize various kinds of information.
[0062] With respect to the above description, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. The novel spirit of the present invention is still embodied by reordering or deleting some of the steps contained in this disclosure. The spirit of the invention is not meant to be limited in any way except by proper construction of the following claims. | A method and apparatus for managing applications installed on a smartcard. The invention comprises a Smartcard Management Program (SMP), a User Action Program (UAP), a User Command Program (UCP), an Application Status Update Program (ASUP), and a Card Status Update Program (CSUP). The SMP interfaces with smartcard communications system and accepts the user commands. The UAP obtains applications from external sources, updates the user profile, and transmits the user profile to the user for viewing on a graphical user interface. The UCP breaks the user commands into card actions and application actions and executes the card actions and application actions. The ASUP updates the user profile by changing the entry in an application name column, an application status column, a user action column, and an information column. The CSUP updates the user profile by changing the entry in the card status field. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 USC §119(e) of U.S. Provisional 60/441,464 filed 21 Jan. 2003, which application is herein specifically incorporated by reference in its entirety.
REFERENCE TO SEQUENCE LISTING
[0002] This application refers to sequences listed in a Sequence Listing hereinto attached, which is considered to be part of the disclosure of the invention.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The field of the invention is related to treating liver steatosis with agents capable of activating the ciliary neurotrophic factor (CNTF) receptor. More specifically, the invention relates to treating liver steatosis in a subject suffering thereof with CNTF or CNTF variants such as, for example, Axokine®.
[0005] 2. Description of Related Art
[0006] Gloaguen et al. (1997) Proc. Natl. Acad. Sci. USA 94:6456-6461 and U.S. Pat. No. 6,565,869 describe the use of ciliary neurotrophic factor (CNTF) for treatment of obesity, including obesity associated with diabetes. Ntambi et al. (2002) Proc. Natl. Acad. Sci. USA 99:11482-11486 describe reduced adiposity in mice targeted with disruption of stearoyl-CoA desaturate (SCD).
SUMMARY OF THE INVENTION
[0007] Experiments described below show that treatment with a modified CNTF molecule correlated with decreased liver steatosis and improved liver function as determined by serum ALT/AST ratio as well as enhanced biochemical responsiveness of the liver to insulin (e.g. phosphorylation of IRS-1, recruitment of PI3-kinase, and Akt-kinase phosphorylation). These changes were accompanied by rapid alterations in hepatic gene expression caused by Axokine™, most notably in the reduced expression of stearyol-CoA desaturase-1 (SCD-1), a rate-limiting enzyme in the synthesis of complex lipids, and increased expression of carnitine palmitoyltransferase-1, a gene which promotes lipid oxidation.
[0008] Accordingly, the invention features a method of treating liver steatosis in a subject in need thereof, comprising administering an agent capable of activating the ciliary neurotrophic factor (CNTF) receptor. In specific embodiments, the agent capable of activating the CNTF receptor is CNTF or a modified CNTF capable of activating the CNTF receptor, for example, Axokine™. Additional CNTF variants are described in U.S. Pat. Nos. 5,349,056, 5,846,935, 6,472,178, 6,440,702, and 6,565,869, which publications are herein specifically incorporated by reference in their entirety.
[0009] Preferred embodiments of the invention are those wherein the agent is formulated with an acceptable pharmaceutical carrier suitable for administration via subcutaneous, intramuscular, intradermal, intraperitoneal, intravenous, intranasal, epidural, and oral routes.
[0010] Further embodiments include a method of treating liver steatosis with an agent capable of activating the CNTF receptor and a second agent capable of ameliorating diabetes, e.g., insulin. In this embodiment, the therapeutic method may allow a decreased amount of the second agent to be administered when administered in combination with an agent of the invention.
[0011] In specific embodiments, the invention provides methods for treating, ameliorating, or improving liver steatosis, wherein treatment results in one or more of improved liver function as determined by ALT/AST ratio, reduced stearyol-CoA desaturase-1 (SCD-1) gene expression or activity, enhanced the biochemical responsiveness of the liver to insulin, and/or reduced synthesis of complex lipids.
[0012] A subject suitable for treatment by the methods of the invention is a mammal, more preferably a human subject, suffering from or at risk from suffering from liver steatosis. Contributing factor may include obesity and/or alcohol abuse, and may be accompanied by increased fat deposition in the liver (steatosis), steatohepatitis, cirrhosis, and hepatocellular carcinoma (Tilg et al. (2000) Mechanisms of Disease 343:1467-1476).
[0013] Other objects and advantages will become apparent from a review of the ensuing detailed description.
BRIEF DESCRIPTION OF THE FIGURES
[0014] FIGS. 1 A- 1 C. Treatment with Axokine™ decreased body weight (FIG. 1 a ) and improves fasating glucose serum glucose (mg/dl) and insulin (ng/ml) levels. Results of an oral glucose tolerance test are shown in FIG. 1 c. All data are expressed as the mean (n≧6)±SEM. ANOVA: % BW, P<0.001 for both C-0.1 and C-0.3; Tolerance Test, P<0.001; glucose P<0.001; Insulin P<0.05. *−difference from ad lib fed db/db vehicle and PF controls by Dunnett post-hoc test.
[0015] FIGS. 2 A- 2 D. Male db/db mice treated with Axokine™ at 0.1 or 0.3 mg/kg/day for 10 days had reduced (FIG. 2A) epididymal white adipose tissue (EWAT) compared to pair-fed (PF) or Vehicle (V) and (FIG. 2B) reduced total liver weight. Liver glycogen content (FIG. 2C) was significantly reduced by pair feeding (PF), while liver function (FIG. 2D) as assessed by the ration of serum ALT/AST was significantly improved by both doses of Axokine. Each bar represents mean±s.e.m. of n=6-8 animals. ANOVA: EWAT, P<0.001; Liver, P<0.001; Glycogen P<0.001. *−difference from ad lib fed db/db vehicle control by Dunnett post-hoc test.
DETAILED DESCRIPTION
[0016] Before the present methods are described, it is to be understood that this invention is not limited to particular methods, and experimental conditions described, as such methods and conditions may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only the appended claims.
[0017] As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. Thus for example, a reference to “a method” includes one or more methods, and/or steps of the type described herein and/or which will become apparent to those persons skilled in the art upon reading this disclosure and so forth.
[0018] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned herein are incorporated by reference.
[0019] General Description
[0020] The invention is based in part on findings that administration of a CNTF variant results in a far greater improvement in body weight and diabetic parameters such as fasting glucose and insulin levels, oral glucose tolerance, triglycerides and non-esterified free-fatty acids than can be achieved by comparable food restriction. The increased weight loss resulting from Axokine™ treatment is correlated with increased energy expenditure. The increased insulin sensitivity induced by Axokine™ administration is correlated with decreased liver steatosis and improved liver function as determined by serum ALT/AST ratio as well as enhanced biochemical responsiveness of the liver to insulin. These changes are accompanied by rapid alterations in hepatic gene expression caused by Axokine™ administration, most notably in the reduced expression of stearoyl-CoA desaturase (SCD-1), a rate-limiting enzyme in the synthesis of complex lipids. In addition, increased expression of camitine palmitoyltransferase-1 (CPT-1), a gene that promotes lipid oxidation, is also observed following Axokine™ administration. Similar changes in hepatic gene expression, and consequent improvements in glucose and lipid metabolism, were not observed in pair-fed or weight-matched control mice. Taken together, these findings demonstrate that Axokine™ exerts metabolic effects that substantially contribute to the marked improvements in glucose and lipid homeostasis in diabetic mice, and which cannot be achieved by equivalent caloric restriction or weight reduction alone.
[0021] Pharmaceutical Compositions
[0022] The present invention also provides pharmaceutical compositions. Such compositions comprise a therapeutically effective amount of an active agent, and a pharmaceutically acceptable carrier. The term “pharmaceutically acceptable” means approved by a regulatory agency of the Federal or a state government or listed in the U.S. Pharmacopeia or other generally recognized pharmacopeia for use in animals, and more particularly, in humans. In a specific embodiment, the composition comprises a combination of an agent of the invention and a second agent capable of ameliorating diabetes. The term “pharmaceutically acceptable” means approved by a regulatory agency of the Federal or a state government or listed in the U.S. Pharmacopeia or other generally recognized pharmacopeia for use in animals, and more particularly in humans. The term “carrier” refers to a diluent, adjuvant, excipient, or vehicle with which the therapeutic is administered. Such pharmaceutical carriers can be sterile liquids, such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil and the like. Suitable pharmaceutical excipients include starch, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene, glycol, water, ethanol and the like. The composition, if desired, can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents. These compositions can take the form of solutions, suspensions, emulsion, tablets, pills, capsules, powders, sustained-release formulations and the like. The composition can be formulated as a suppository, with traditional binders and carriers such as triglycerides. Oral formulation can include standard carriers such as pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharine, cellulose, magnesium carbonate, etc. Examples of suitable pharmaceutical carriers are described in “Remington's Pharmaceutical Sciences” by E. W. Martin.
[0023] In a preferred embodiment, the composition is formulated in accordance with routine procedures as a pharmaceutical composition adapted for intravenous administration to human beings. Where necessary, the composition may also include a solubilizing agent and a local anesthetic such as lidocaine to ease pain at the site of the injection. Where the composition is to be administered by infusion, it can be dispensed with an infusion bottle containing sterile pharmaceutical grade water or saline. Where the composition is administered by injection, an ampoule of sterile water for injection or saline can be provided so that the ingredients may be mixed prior to administration.
[0024] The active agents of the invention can be formulated as neutral or salt forms. Pharmaceutically acceptable salts include those formed with free amino groups such as those derived from hydrochloric, phosphoric, acetic, oxalic, tartaric acids, etc., and those formed with free carboxyl groups such as those derived from sodium, potassium, ammonium, calcium, ferric hydroxides, isopropylamine, triethylamine, 2-ethylamino ethanol, histidine, procaine, etc.
[0025] The amount of the active agent of the invention which will be effective in the amelioration of type 2 diabetes can be determined by standard clinical techniques based on the present description. In addition, in vitro assays may optionally be employed to help identify optimal dosage ranges. The precise dose to be employed in the formulation will also depend on the route of administration, and the seriousness of the condition, and should be decided according to the judgment of the practitioner and each subject's circumstances. However, suitable dosage ranges for intravenous administration are generally about 20-500 micrograms of active compound per kilogram body weight. Suitable dosage ranges for intranasal administration are generally about 0.01 pg/kg body weight to 1 mg/kg body weight. Effective doses may be extrapolated from dose-response curves derived from in vitro or animal model test systems.
[0026] Combination Therapies
[0027] In numerous embodiments, the fusion polypeptides of the present invention may be administered in combination with one or more additional compounds or therapies. For example, CNTF or a modified CNTF can be co-administered in conjunction with one or more therapeutic compounds. The combination therapy may encompass simultaneous or alternating administration. In addition, the combination may encompass acute or chronic administration.
[0028] Treatment Population
[0029] Hepatic steatosis, also termed fatty liver, may be caused by a number of factors, including long term consumption of alcohol, obesity, exposure to hepatotoxins, and infection. In many patients, a specific risk factor may not be identified. Methods for clinical identification of hepatic steatosis are known to those of skill in the art. Accordingly, the population of patients to be treated with the methods of the invention are clinically identified through standard tests of liver function.
EXAMPLES
[0030] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the methods and compositions of the invention, and are not intended to limit the scope of what the inventors regard as their invention. Efforts have been made to ensure accuracy with respect to numbers used (e.g., amounts, temperature, etc.) but some experimental errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, molecular weight is average molecular weight, temperature is in degrees Centigrade, and pressure is at or near atmospheric.
Example 1
[0031] Materials and Methods
[0032] Animals and Experimental procedures. Male C57BL/KS-Lep db (db/db ) and non-diabetic littermate mice (obtained from Jackson Laboratories) were obtained at 7-8 weeks of age, and were housed in 12 h of light per day at 69-74° C. and 40-60% humidity. All experiments began at 10 weeks of age and all animal procedures were conducted in compliance with protocols approved by the Institutional Animal Care and Use Committee. Axokine™ is a recombinant variant of human CNTF (for a complete description, see U.S. Pat. No. 6,472,178). Axokine™ (0.1 and 0.3 mg/kg, s.c.) and vehicle (V; 10 mM Sodium Phosphate, 0.05% Tween 80, 3%o PEG 3350, 20% Sucrose pH 7.5) were injected daily for 10 days. For glucose tolerance testing, all animals were fasted for 16-18 hours before gavaging with a standard glucose bolus, as previously outlined (Tonra et al. (1999) Diabetes 48(3), 588-94). For assessment of insulin activation of signaling molecules, animals from long term dosing studies outlined above were anesthetized and a bolus of insulin (1 U/kg) was administered through the jugular vein and at the indicated times the liver was rapidly removed and frozen at −80° C. until it could be processed.
[0033] Serum chemistry and tissue analysis. Serum samples reported were taken between 10:00 and 12:00 h and analyzed for glucose, triglycerides and cholesterol utilizing the Monarch blood chemistry analyzer (Instrumentation Laboratory Company, Lexington, Mass.). NEFAs were analyzed with a diagnostic kit (WAKO, Richmond, Va.) and insulin levels by ELISA (Linco, St. Charles, Mo.). Tissue samples for histological analysis were taken from all mice at the conclusion of the experiments and fixed overnight in 10% buffered formalin. For H&E staining, tissue was embedded in paraffin, sections cut at approximately 6 mm, placed onto glass slides, deparaffinized with xylene and processed using standard methods. For analysis of endogenous lipids, frozen sections of liver were mounted on glass slides and stained with Oil red O. Liver glycogen was measured from frozen tissues by assaying for glucose after amyloglucosidase digestion, with a correction for non-glycogen glucose.
[0034] Tissue lysates and SDS-PAGE. Liver samples were separately homogenized on ice in buffer A (1% NP-40 buffer, 50 mM Hepes pH 7.4, 150 mM NaCl, 1 mM EDTA, 30 mM sodium pyrophosphate, 50 mM sodium fluoride, 0.5 mM sodium orthovanadate, 5 μg/ml aprotinin, 5 μg/ml leupeptin, 1 mM PMSF) and centrifuged for 10 min at 14,000 g. The supernatant was taken and protein level quantified (BCA protein assay, Pierce, Rutherford, Ill.) and either used for immunoprecipitation or equal amounts of protein resolved by SDS-PAGE (Novex, 8% precast gels). Proteins were transferred to nitrocellulose membranes to be blocked and then immunoblotted with phospho-specific Akt (Ser473) polyclonal antibodies (New England BioLabs, Beverley, Mass.). After secondary antibody incubation (Goat anti-Rabbit HRP conjugated, Boehringer Mannheim) detection was by an enhanced chemiluminescence detection system (Renaissance, Dupont NEN products).
[0035] Real Time PCR and Northern Blotting. Tissues were rapidly dissected and immediately frozen at −80° C. RNA was isolated using Tri-reagent (MRC, Cincinnati, Ohio). Tissue specific expression was analyzed in separate reactions using the Taqman (Applied Biosystems, Foster City, Calif.) real-time PCR chemistry and detection system (SCD-1 forward 5′-GGTACTACAAGCCCGGCCTC-3′ (SEQ ID NO:1), reverse 5′-AGCAGTACCAGGGCACCAGC -3′ (SEQ ID NO:2) SCD-1 probe 6-FAM-TGCTGATGTGCTTCATCCTGCCCA(SEQ ID NO:3); GPAT forward 5′-CAGACGAAGCCTTCCGACG-3′ (SEQ ID NO:4), GPAT reverse 5′-GACTTGCTGGCGGTGAAGAG-3′ (SEQ ID NO:5), GPAT probe 6-FAM-AGGCTGATTGCAAACCTGGCTGAGC-TAMRA (SEQ ID NO:6); CPT-1 forward 5′-CTGCAACTTTGTGCTGGCC-3′ (SEQ ID NO:7), reverse 5′-TTGAACAGCTTGAGCCTCTGC-3′ (SEQ ID NO:8) CPT-1 probe 6-FAM-TGATGGACCCCACAACAACGGCA (SEQ ID NO:9); PPARα-forward 5′-GCCGAGAAGACGCTTGTGG-3′ (SEQ ID NO:10), PPARα-reverse 5′-TCGGACCTCTGCCTCTTTGTC-3′ (SEQ ID NO:11), PPARα-probe 6-FAM-CAAGATGGTGGCCAACGGCGTC-TAMRA (SEQ ID NO:12); PPARγ-forward 5′-ATGCCATTCTGGCCCACC-3′ (SEQ ID NO:13), PPARγ-reverse 5′-GGAATGCGAGTGGTCTTCCATC-3′ (SEQ ID NO:14), PPARγ-probe 6-FAM-ACTTCGGAATCAGCTCTGTGGACCTCTCC-TAMRA (SEQ ID NO:15); UCP 2 forward 5′-TAGTGCGCACCGCAGCC-3′ (SEQ ID NO:16), UCP 2 reverse 5′-AGCTCATCTGGCGCTGCAG-3′ (SEQ ID NO:17), UCP 2 probe 6-FAM-CAGTACCGTGGCGTTCTGGGTACCATC-TAMRA (SEQ ID NO:18). Control genomic DNA was used as a standard to estimate copies of molecule per cell and all probes were run with a no-reverse transcriptase control for assessment of any genomic DNA contamination. Samples were done in duplicate from pools of 3 individual animal samples. Results are expressed as fold change from vehicle treated db/db levels. Northern blots were done on samples from pools of 3, as described previously (Lambert et. al. (2001) Proc. Natl. Acad. Sci. USA, 98, 652-4657).
[0036] Indirect Calorimetry. Metabolic measurements were obtained using an Oxymax (Columbus Instruments International Corp., Columbus, Ohio) open circuit indirect calorimetry system. The system was calibrated against standard gas mixture to measure O 2 consumed (ml/kg/h) and CO 2 generated (ml/kg/hr). Energy expenditure (or heat) was calculated as the product of calorific value of oxygen (=3.815+1.232×respiratory quotient) and the volume of O 2 consumed. These measurements were taken on animals that had received 9 days of Axokine™ or vehicle treatment. The first 2 h of measurements was used as a period of adaptation for the animals and metabolic rate and activity were evaluated for a 24 hr period.
[0037] Statistical analyses. Data is expressed as mean±s.e.m. and analysis of variance (ANOVA) conducted using the program STATVIEW. When a significant F ratio was obtained (significance P<0.05), post hoc analysis was conducted between groups using a multiple comparison procedure with Bonferroni/Dunn correction of means (ANOVA rm ) or Dunnett post hoc comparison. P-values less than P<0.05 were considered significant.
Example 2
[0038] Dose Dependent Effect of Axokine™ on Body Weight.
[0039] To further explore the effects of Axokine™ on glucose and lipid metabolism, studies were conducted in C57BL/KS-Lep db (db/db) mice, a murine model of type 2 diabetes that results from loss of functional leptin receptors (ObR's), and is thus leptin-resistant. In this strain of mice, the metabolic abnormalities manifest early during development, and are quite severe in young adult animals. Moreover, once established, these metabolic changes are resistant to modulation by caloric restriction or weight reduction, compared to other mouse models of obesity-associated insulin-resistance and dyslipidemia (Tonra et al. (1999) Diabetes 48(3), 588-94).
[0040] Groups of db/db mice received a daily subcutaneous injection of vehicle (V), Axokine™ at 0.1 or 0.3 mg/kg/day (C-0.1 or C-0.3) or were provided with the same amount of chow eaten by the C-0.3 treatment group (PF). Results are shown in FIGS. 1 A-C.
[0041] Administration of Axokine™ to 10 week-old diabetic db/db mice decreased body weight in a dose dependent fashion (FIG. 1A). Even though this weight loss was associated with a dose-dependent decrease in food intake, matching caloric intake in a cohort of control db/db mice (“pair-fed”; PF) did not result in an equivalent weight loss. This is in contrast to observations made in other models of obesity, such as ob/ob mice or diet induced obesity (DIO), where little or no difference in weight loss is evident between CNTF-treated mice and PF controls.
[0042] Vehicle treated db/db mice (V) exhibited the fasting hyperglycemia (630±50 mg/dL), hyperinsulinemia (5.2±0.75 ng/ml) and impaired glucose tolerance characteristic of this strain. Fasting plasma glucose and insulin levels were significantly reduced in mice treated with Axokine™ (FIG. 1 b ), and oral glucose tolerance was also markedly improved (FIG. 1C; ANOVA, for both group and interaction, P<0.001). Similar improvements in glucose and insulin homeostasis were not seen in food-restricted control mice, matched for either equivalent caloric intake (c.f. C-0.3, animals receiving 0.3 mg/kg/d Axokine™) or body mass (c.f. C-0.1, animals receiving 0.1 mg/kg/d Axokine). Serum non-esterified free fatty acids (NEFAs) and triglycerides were also significantly reduced by Axokine™ relative to levels evident in both V and PF control mice (see Table 1).
TABLE 1 Effect of Treatment with Axokine ™ db/db Parameter db/? Vehicle C-0.1 C-0.3 PF No. and sex 24 males 12 males 24 males 24 males 18 males Body Weight (g) 26.4 ± 0.4* 40.0 ± 0.6 35.3 ± 0.4* 31.5 ± 0.6* 35.7 ± 0.5* Insulin (ng/ml) 1.0 ± 0.2* 5.2 ± 0.8 4.3 ± 0.4 2.9 ± 0.4 4.9 ± 0.4 Glucose (mg/dl) 185 ± 8* 630 ± 50 285 ± 32* 213 ± 23* 631 ± 44 NEFA (mmol/l) 0.88 ± 0.05* 1.53 ± 0.09 1.00 ± 0.1* 1.05 ± 0.07* 1.22 ± 0.04 Triglyceride (mg/dl) 69 ± 4* 92 ± 10 70 ± 6 57 ± 3* 73 ± 3 Cholesterol (mg/dl) 91 ± 5 121 ± 14 115 ± 5 89 ± 7* 92 ± 3*
Example 3
[0043] Effect of Axokine™ on Non-Fasting Serum Glucose Levels.
[0044] In an experiment conducted on a separate cohort of mice, the effect of Axokine™ on non-fasting serum glucose levels was apparent within 2 days of the initiation of treatment, with a 50% reduction evident by day 4 (P <0.05), and reaching near non-diabetic control levels by day 10 (213±23; not significantly different from lean db/? controls, 185±8 mg/dL). At no time were any of the Axokine™-treated db/db mice hypoglycemic. Caloric restriction did produce a modest (˜25%) reduction in serum cholesterol levels, similar to that observed with Axokine™ treatment. However, food-restriction alone again failed to improve glycemic control in db/db mice. This observation is particularly significant, as rigorous control of hyperglycemia in diabetic humans can significantly attenuate the development of chronic complications associated with type-2 diabetes such as retinopathy and nephropathy (Colagiuri et al. (2002) Diabetes Care 25:1410-7); Klein et al. (1998) Diabetes Care 21 Suppl 3:C39-43).
Example 4
[0045] Effect of Axokine™ Treatment on Epididymal White Adipose Tissue.
[0046] The effect of Axokine™ treatment on epididymal white adipose tissue (EWAT). The mass of this fat depot was reduced significantly in mice treated with Axokine (FIG. 2A) compared to mice injected with vehicle. Pair-feeding tended to reduce EWAT weight, though not to the same degree as that seen in Axokine™ treated mice. Microscopic evaluation revealed no obvious changes in adipocyte cell morphology in the EWAT of Axokine™ treated mice relative to PF controls, and there was no evidence of multi-locular cells type of the development of brown adiposities.
Example 5
[0047] Measurement of Serum and Tissue Markers of Hepatic Function.
[0048] Serum and tissues markers of hepatic function were measured as described above. H &E staining of liver sections revealed reduced lipid vacuoles, which was confirmed by Oil Red-O staining which showed a clear reduction in the deposition of neutral lipids in CNTF treated groups, compared to both pair-fed and vehicle injected controls. Characteristically, db/db mice present with moderate hepatomegaly (FIG. 2B) and impaired liver function as indicated by an elevation in the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) (FIG. 2D). These changes are thought to be secondary to hepatic accumulation of fat, which is evident in hematoxylin and eosin and Oil Red 0 stained sections of the livers of control db/db mice. Treatment of db/db mice with Axokine™ reduced the liver weight and normalized the serum ALT/AST. Lipid deposition in liver was also markedly reduced. In contrast, caloric restriction produced only a small, non-significant reduction in liver weight, which was accompanied by a marked depletion of hepatic glycogen stores. Caloric restriction did not improve hepatic function (ALT/AST) or decrease lipid deposition in the liver. The combined effect of Axokine™ to reduce serum glucose and lipid levels, preserve liver glycogen, reduce the ALT/AST ratio as well as the deposition of neutral lipid in the liver, are indicative of a marked improvement in obesity-related fatty liver that is distinct from the effects of food restriction or weight reduction alone.
Example 6
[0049] Axokine™ Treatment Restores Hepatic Insulin Sensitivity.
[0050] After 10 days of Axokine™ treatment as outlined above, mice were anaesthetized, and an i.v. bolus of insulin or vehicle was administered. The liver was removed and frozen in liquid nitrogen 2 minutes later. Equal amounts of liver homegenate were immunoprecipitated with anti-IRS-i and blotted with anti-phosophotyrosine (pTyr) or antibodies against the p85 subunit of P13-kinase (p85). Comparison of the signals obtained showed rapid tyrosine phosphorylation of IRS-1 and the recruitment of the p85 subunit of PI3-kinase in lean non-diabetic mice and a blunted response in the vehicle treated db/db mice state. In contrast, robust tyrosine phosphorylation of IRS-1 and subsequent p85 recruitment was seen consistently in both groups of Axokine™ treated mice (C-0.1 and C-0.3), but not pair-fed mice. Activation of the downstream signaling molecule Akt-kinase was assessed with phospho-specific antibodies of lysates taken from similarly treated mice 10 min after insulin administration. A consistent increase in phospho-Akt was observed in lean control mice, but not in diabetic mice that were injected with vehicle or pair-fed. In contrast, the insulin stimulated increase in phospho-Akt was at least as robust in Axokine™-treated db/db mice as in lean, non-diabetic littermates. Moreover, a clear decrease in basal levels of phospho-Akt was evident in PF mice, and this was also corrected by administration of Axokine™.
Example 7
[0051] Evaluation of Differential Changes in Gene Expression.
[0052] To elucidate the molecular mechanism by which Axokine™ induces the physiological changes described supra, differential changes in gene expression were probed by northern blot analysis as well as real time PCR assays (Taqman) in hepatic tissue as follows. Liver tissue was collected from male db/db mice treated with Axokine (C-0.3) for 4 days and from pair-fed or vehicle-injected controls. Total RNA was prepared for assessment by Northern blots for stearoyl-CoA desaturase (SCD-1), glycerol-palmitoyl acyl-transferase (GPAT), CPT-1 and UCP-2 & PPARa PPARg, phosphoenolpyruvate carboxylase (PEPCK) and acyl CoA oxidase (ACO). Each lane represents a pool of RNA from 3 mice. The same RNA sample were analyzed by real time PCR and results are expressed as bar graphs as the fold increase/decrease relative to controls that received only vehicle injections (mean±SEM n=6-10 individual samples). ANOVA: CPT-1 P<0.001; PPARg ,P<0.001; GPAT P<0.001. *−difference from ad lib fed db/db vehicle control by Dunnett post-hoc test. One of the most striking features of Axokine™ treatment was the specific decrease in the expression of genes associated with triacylglycerol synthesis and uptake in liver, such as GPAT and SCD-1; the changes in SCD-1 in particular were far more impressive than those noted with PF alone. Associated with treatment, but also evident in the PF group, is an increase in PPARα mRNA (<2 fold), together with its target enzymes of FA oxidation, CPT-1 and UCP-2. No change could be could be detected in ACO mRNA, however there may be subtle changes in activation of this enzymes that may further contribute to increased b-oxidation. The net effect of these changes would be to reduce fatty acid biosynthesis and decrease hepatic lipid content, consistent with the above histological and serum chemistry results. The expression of several genes important in carbohydrate metabolism and known to be regulated by leptin, such as PEPCK, glucose-6-phosphatase, fructose bisphosphatase and hexokinase, were not altered by Axokine™ treatment. Analysis of EWAT showed Axokine™ administration produced a rapid, two-fold decrease in mRNA for fatty acid synthase (FAS) in EWAT, but surprisingly no changes in expression in ACC, GPAT, PPARγ UCP-1, UCP-2, UCP-3, GLUT4, GLUT1 and CPT-1 could be detected in EWAT by RT-PCR.
[0053] These findings suggest that, in addition to its established appetite-suppressing actions in the hypothalamus, Axokine™ acts to decrease the synthesis and increase the oxidation of lipids in the livers of db/db mice. Here, the specific Axokine™-mediated reduction in the expression of hepatic SCD-1 is particularly noteworthy. Recently, Cohen et al. (2002) Science 297:240-243) reported that leptin administration dramatically reduced SCD-1 expression in the livers of ob/ob mice. Moreover, mice deficient in SCD-1 were lean and hyper-metabolic, while ob/ob mice bearing a mutation in the SCD-1 gene were less obese and exhibit elevated levels of energy expenditure compared to control ob/ob mice. The livers of these mice were histologically normal, and triglyceride stores were much reduced. These effects of leptin in ob/ob mice closely parallel the effects of Axokine™ on liver structure and function observed here in obese, diabetic db/db mice, suggesting that Axokine™ might also exert a positive effect on energy expenditure that could account for the differential loss in body weight seen in treated mice compared to pair-fed controls.
Example 8
[0054] Assessment of Effects of Axokine™ on Energy Expenditure.
[0055] Groups of db/db mice received daily subcutaneous injections of vehicle or Axokine™ (0.3 mg/kg, C-0.3) for 9 days. Indirect calorimetry was performed over a 24 hour period following the last injection. Oxygen consumption (VO 2 ; ml/kg/hr); carbon dioxide production (VCO 2 ; ml/kg/hr), energy expenditure as heat (kcal/hr), and locomotor activity was measured for C-0.3 and V treated groups in at approximately 1 hr intervals. ANOVA: oxygen, P<0.001; carbon dioxide, P <0.001; energy P<0.001. Control and Axokine™ treated mice were evaluated by indirect calorimetry to assess the effects of Axokine™ administration on energy expenditure. In control db/db mice, metabolic rate is increased during the dark period (night), as indicated by increased oxygen consumption and carbon dioxide production. These parameters are reduced in the subsequent light period, when the animals are normally at rest. Control mice also showed an increase in heat production during the dark period, reflecting the combined effects of increased physical activity and/or thermogenesis. Heat production declines in the lights-on period (day) when the animals are at rest, and thus reflects basal energy expenditure. Treatment of db/db mice with Axokine induced an increase in metabolic rate, as evidenced by elevations in VO 2 and VCO 2 and increased energy expenditure relative to controls, particularly during the light period. Locomotor activity was characteristically higher during the dark period than during the light period in control db/db mice, and neither the pattern nor overall level of activity was altered by Axokine™ treatment, indicating that the observed increase in energy expenditure was not secondary to increased physical activity. Axokine™ treatment did not induce a switch in metabolic substrate (i.e. a differential respiratory quotient or VCO 2 /VO 2 ratio). These observations show that Axokine™ treatment can produce a differential reduction in body weight in obese and diabetic (db/db) mice by decreasing appetite while maintaining or increasing energy expenditure, as is the case for leptin treatment in the leptin-deficient ob/ob mice. That Axokine™ treatment also reduces hepatic expression of SCD-1 supports the proposal that this enzyme plays a key role in mediating the pro-metabolic effects of these both of these proteins. | Methods of treating, inhibiting, and/or ameliorating liver steatosis in a subject in need thereof, comprising adminstering an agent capable of activating a ciliary neurotrophic factor (CNTF) receptor. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an operating device for rolling shutters.
2. History of the Related Art
Generally, a rolling shutter assembly comprises a shaft around which a shutter can be more or less rolled up according to the rotation of the shaft around its elongated axis. Driving systems for rotating the shaft are of diversified types. They may consist of an electric motor or of a mechanical winch. It is also possible that a user would operate the rolling shutter by direct action, for which is provided an equalizing mechanism capable of holding the shutter in a position in which it is left by the user.
In any case, sometimes it is necessary to disengage the rolling shutter's driving mechanism because of security reasons or to service the mechanism. In the previously known devices it was necessary to provide a specific disengaging system, which system had to be the subject of an elaborate study of the resistance of the materials and required the manufacture of specific parts.
SUMMARY OF THE INVENTION
The present invention is designed to provide an operating device for rolling shutters that allows an effective disengagement of the driving mechanism, which is low in cost, reliable to operate and easy to install.
With this in mind, the present invention relates to an operating device for rolling shutters comprising a reeling shaft for a shutter rotated by a motor held by a collar, characterized by the fact that the collar is attached to a toothed wheel that can engage with a screw so as to immobilize the rotating collar. The threads of the screw is provided with at least one flat, so that the mechanical connection between the toothed wheel and the screw can be engaged and disengaged.
According to the present invention, it is particularly easy to disengage the operating device because it suffices to turn the screw until one of its flats faces the toothed wheel; the play between the screw and the toothed wheel is then sufficient to allow a movement of one with respect to the other.
The invention is particularly attractive from a cost-effective point of view because it is based on the use of a toothed wheel and a screw that are widely used in mechanical winch drives of reeling shafts for rolling shutters. This use of elements, already widely known, avoids a thorough study of the resistance of the materials. In its customary application, the winch functions to block rotation as well as acts as a connection between several mechanical components. Thus, such a winch is already designed for use with this new application because essentially it carries out the same functions.
This use of already widely utilized components also avoids the duplication of components being machined because it is unnecessary to machine new parts. The thus obtained mass produced parts allows for a reduction in the unit price of components already in use.
From a mechanical point of view, the endless screw and the toothed wheel comprising the winch provide a reliable immobilization of rotation because the holding effect is obtained by a gear that is particularly suited for transmission action, and thus for the blocking or inhibiting of rotation.
These components provide an easily disengaged device because the angle of the gear is designed with respect to the rotation of the screw, even under stress; thus, it is easy to disengage the device. Moreover, the use of a system comprising a screw and a toothed wheel presupposes the assurance that, due to the multiple teeth disposed along the periphery of the wheel and to the continuity of the screw's thread, a re-engaging position can be easily and rapidly found.
According to an advantageous variation of the present invention, the screw is provided with two flats that are symmetrically arranged opposite to its elongated axis. Furthermore, the device can be provided with means for an elastic positioning of the screw.
Lastly, the present invention can be used with a device that comprises an equalizer spring suitable to cause the rotation of the shaft in such a manner as to roll-up the shutter when the connection between the wheel and the screw is disengaged. The present invention can also be used with a device that comprises a speed reduction unit for lowering the shutter when the connection between the toothed wheel and the screw is disengaged. In all cases, the screw can be formed by a simple tooling of a screw used in a standard operating device for rolling shutters provided with a mechanical winch.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood and its other advantages will be more clearly elucidated in light of the below description of four embodiments of an operating device for rolling shutters in accordance with its principle, given solely by way of example and referenced in the hereto attached drawings wherein:
FIG. 1 shows a front cross-sectional view having portions broken away of a rolling shutter incorporating a first embodiment of the present invention;
FIG. 2 is an enlarged cross-sectional view along the line II--II of FIG. 1, showing the device in an engaged position;
FIG. 3 is an enlarged cross-sectional view along the line III--III of FIG. 2;
FIG. 4 is a view similar to that of FIG. 2, showing the device disengaged;
FIG. 5 is a sectional view similar to that of FIG. 3 showing the device disengaged;
FIG. 6 is a view similar to that of FIG. 1, showing a second embodiment of an operating device for rolling shutters;
FIG. 7 is a detailed cross-sectional view of a portion of an operating device for rolling shutters in accordance with a third embodiment of the present invention; and
FIG. 8 is a view similar to that of FIG. 7 showing a fourth embodiment of an operating device for rolling shutters.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The device 1 to operate rolling shutters shown in FIG. 1 is essentially constituted by a reeling shaft 2 on which is housed a tubular motor comprising a stationary housing 3 containing an electric motor 4, a reduction unit 5 and a limit switch 6. A flange 7 upon which rests the housing 3, is firmly attached to a stationary bracket 8 by means of a shaft 7a that extends into a housing 9 of which the sheathing is firmly attached to the bracket 8. A collar 10, affixed to the shaft 2, is provided with inside teeth that interact with a pinion, not shown herein, that conveys to the limit switch the movement of the shaft 2. The output shaft of the reduction unit 5 is provided with a disk 11 that is engaged with the shaft 2 and is suitable to impart a rotating movement from the motor to the reeling shaft.
An equalizer spring 12 is housed inside of the shaft 2 in the proximity of its other end. One end of the spring 12 is attached to a stationary disk 13 inside the shaft 2 while its other end is attached to a movable second disk 14 that rotates together with the shaft 2. A spindle 15 holds the disk 13 and it is attached by means of a bolt or strap 16 to a supporting bracket 17.
The mechanism operates as follows. When the shutter 18 of the rolling shutter assembly is completely wound up around the shaft 2, the equalizer spring 12 is not stretched. Should it be necessary to close the rolling shutter, the electric motor 4 is activated in such a manner that, through the reduction unit 5 and the driving disk 11, it imparts a torque on the shaft 2, which gradually unrolls the shutter 18. The rotating movement of the shaft 2 gradually stretches the spring 12 so that it stores energy. The movement of the shutter 18 may be stopped at any time by means of a brake, not shown herein, that is coupled to the motor 4. When it becomes necessary to roll-up the shutter 18 of the rolling shutter assembly, the motor is activated in a reverse direction in order to impart upon the shaft 2 a rotating movement in a reverse direction. The equalizer spring 12 then tends to cause the shaft 2 to rotate in the same direction as the motor 4 by releasing the energy it had stored at the time of the lowering of the shutter.
The equalizer spring 12 is dimensioned in such a manner that, in the absence of the motor 4 and the brake associated therewith, it causes the rewinding of the shutter. From FIG. 2 it can be clearly seen that the housing 9 includes a toothed wheel 19 that rotates together with the shaft 7a. The wheel is fixed to this shaft, by way of example, by a nut 20.
In accordance with the present invention, an endless screw 21 is provided in the proximity of the toothed wheel 19, so that, as shown in FIG. 3, the teeth of the toothed wheel mesh with the thread of the screw 21. The screw 21 is a screw of the type used in an operating device for rolling shutters provided with a mechanical winch. Thus, the screw is a component that is already mass produced at a relatively low cost. This screw is held between two plates 22 and 23 and supported by the ends of two springs 24 and 25 resting against thrust bearings or nuts 26 and 27 of the housing 9. Thus, the springs 24 and 25 constitute a means for a resilient or elastic positioning of the screw 21 opposite or perpendicular to the axis of the shaft 2. A handle 30 is connected to the plate 22 through the bearing 26 and the spring 24. This handle enables the screw 21 to be rotated about its axis.
In accordance with the present invention, and more clearly shown in FIGS. 4 and 5, the screw threads are provided with pairs of two oppositely oriented flats 21a and 21b. These flats allow a space or play "J" to be created between the outside edges of the thread of the screw 21 and the outside edges of the teeth of the toothed wheel 19, so that the mechanical connection between the toothed wheel and the screw is disengaged when the screw is in the position shown in FIG. 5. Preferably, the play "J" should be of less than 10 mm and of the order of a few millimeters.
The embodiments of FIGS. 1 to 5 show the use of the present invention on a security shutter or door. In fact, when it becomes necessary to rapidly open the shutter by means of this embodiment, it suffices to turn the handle 30 one quarter of a turn in order to disengage the device and allow the rotation of the flange 7 and of the motor 4 so that, under the effect of the equalizer spring 12, and eventually by a vertical upward thrust, the shutter is rolled-up around the shaft 2.
When it becomes necessary to operate the device by means of the electric motor 4, it suffices to turn the handle 30 one quarter of a turn in the same or in the opposite direction in order to reestablish the mechanical connection between the toothed wheel 19 and the screw 21, as shown in FIG. 3. It can be noted that because of the design of the device with a toothed wheel and a screw, it is possible to easily and rapidly obtain the re-engagement because of the multiple teeth of the wheel 19 and of the threads of the screw 21 having the flats 21a and 21b.
Moreover, it is particularly easy to disengage the device. A turn of the handle 30 about the axis of the screw in a first direction or in the reverse trigonometric direction causes the device to disengage, which is of special importance when this device must be operated by an individual not familiarized with the device or acting in a state of panic.
It must be noted that due to the utilization of components used in large quantities by mechanical winches, the cost of these components is low and therefore the cost of the thus obtained release mechanism is also low.
FIG. 6 shows an application of the invention on a fireproof door. The reference numbers of the parts or components similar or identical to those of FIG. 1 are increased by 50.
The essential difference between this device 51 and the embodiment of FIGS. 1 to 5 is that it does not have an equalizer spring and that a vibratory release unit 62 acts as a speed-reducer for the movement of the shaft 52. By using the invention, it is possible to disengage the mechanical connection between a toothed wheel 69 attached to the shaft 57a and a screw 71 mounted in a housing 59 secured to a bracket 58. When the mechanical connection between the toothed wheel 69 and the screw 71 is disengaged, the shutter 68 is driven by gravity and it is unwound from the shaft 52, while being slowed or restrained by the release unit 62.
This device is particularly advantageous for use with fireproof doors. In fact, as before, it is easy to manipulate the screw 71 to disengage the mechanical connection with the toothed wheel 69, thus releasing the shutter 68 in the case of fire. As in the previous embodiment, it suffices to turn the screw 71 one quarter turn in the reverse direction, or in the same direction, to re-engage the device to enable the movement of the shutter 68 to be actuated by means of the electric motor 54.
FIG. 7 is a detailed view of a portion of an operating device for rolling shutters in accordance with a third embodiment of the present invention in which the reference numbers of the parts similar to those of FIG. 1 to FIG. 5 are increased by 100.
This device 101 comprises a reeling shaft 102 in which is set a housing 103 comprising an electric motor, not shown herein. A limit switch 106 is connected to a collar 110 that is fixed to the reeling shaft 102 by a driving pinion 131 which, because of the inside teeth 110a of the collar 110, imparts upon the device 106 the movements of the shaft 102. A flange 107 is fixed to the housing 103. A shaft 107a extends from the flange into a housing 109 that, in accordance with the present invention and similar to the first embodiment, includes a toothed wheel 119 and an endless screw 121. Moreover, this device includes a stationary part 132 housed in the shaft 102 and supporting the limit switch 106 and the flange 107. The part 132 carries one half 133a of a rotating connector 133, of which the other half 133b rests on the flange 107. The rotating connector can be of any known type and, by way of example, with contact brushes sliding on a contact surface. Through this connector, electric current is fed to the motor by means of a cable 134, of which one part is attached to the housing 109 and to part 132 while another part 134b enters into an aperture 107b in the flange 107.
When the device of the present invention is disengaged, that is to say, when the endless screw is in its position in which a thread is spaced from the toothed wheel 119, the toothed wheel is being driven, by example, by an equalizer spring of the type shown in FIG. 1, and the flange 107 rotates in relation to the stationary part 132 so that an electric cable can be simply attached to these two components. The reason being, that the rotating connector 133 is provided between them so that the cable 134 will not be damaged by movement after the device is disengaged.
FIG. 8 shows a fourth embodiment of the present invention in which the reference numbers of the parts similar to those of FIG. 7 are increased by 100. This device differs from the previous one essentially in that a differential connection is provided between the shaft 207a and the flange 207, and because the limit switch is replaced with detectors that, by way of example, are positioned along the path of the rolling shutter.
The differential connection between the shaft 207a and the flange 207 is established by means of a toothed wheel 237 mounted at the opposite extremity of the shaft 207a that is provided with the toothed wheel 219. The toothed wheel 232a engages with a pinion 238 that meshes with inside teeth 232a of the stationary part 232. The axis of rotation 239 of the pinion 238 rests upon the flange 207 in such a manner that the toothed wheel 237 may cause the flange 207 to rotate by using the pinion 238 as a planet gear. It is understood that several pinions 238, may be distributed along the periphery of the toothed wheel 237.
The mechanism operates as follows. While the toothed wheel 219 is immobilized by the endless screw 221, the toothed wheel 237 blocks the rotation of the flange 207. Should the connection between the endless screw 221 and the toothed wheel 219 be disengaged, the toothed wheel 237 may be turned by the pinion 238 and it no longer prevents the movement of the flange 207.
The differential connection established between the toothed wheel 219 and the flange 207 allows the use of the ratio of the number of teeth of the elements 237, 238 and 232a in order to constitute a speed reducer. Moreover, this construction is particularly advantageous for heavy rolling shutters, such as the protective iron bars of stores. In fact, in such a case, the motor is subjected to a considerable torque and the differential connection allows a reduction of the stress at the contact point between the endless screw 221 and the toothed wheel 219, which leads to a reduction of the disengaging stress of their respective teeth and facilitates the release.
It is understood that the differential connection is also applicable to a mechanism that incorporates a limit switch. This modification is within the understanding of those skilled in the art.
This invention was explained with rolling shutters driven by electric motors but it is applicable to whatsoever type of driving device is used for rolling shutters. In particular, it is applicable to a rolling shutter operated by means of a mechanical winch. | An operating device for a rolling shutter assembly comprising a reeling shaft for a shutter wherein the shaft is rotated by a motor connected to a flange. The flange is fixed to a toothed wheel that can mesh with a thread of a screw so as to immobilize the rotation of the flange. The thread of the screw is provided with at least one flat, so that the mechanical connection between the toothed wheel and the screw can be disengaged when a flat is positioned adjacent the toothed wheel. Disconnection of the screw from the wheel allows a rapid operation of the shutter for reasons of security or maintenance. | 4 |
This is a divisional of application Ser. No. 08/098,530, filed on Jul. 28, 1993, now U.S. Pat. No. 5,419,096.
FIELD OF THE INVENTION
This invention relates to packages for food products which are adapted for gaseous exchange to extend the life of the food product. Particularly, this invention relates to such packages, packaging methods, and packaging apparatus adapted to contain relatively large meat products such as whole chickens, roasts, or other large meat products.
BACKGROUND OF THE INVENTION
Domed meat packages have been used in the past to contain large cuts of meats such as chickens or roasts. However, these packages have suffered from a number of drawbacks.
It is desirable to control the atmosphere within the meat package to delay the aging of the food product and to extend its shelf life in the supermarket. For example, by providing low oxygen environments, the shelf life of the food product can be extended from a few days to as long as two weeks or more perhaps.
In order to make the customer feel comfortable with the food packaging, the customer should be able to view a substantial portion of the food product. In order to maintain a desired atmosphere around the package, a package which is somewhat larger than the food product is required. However, with a large, relatively heavy meat product it is difficult to allow for spacing around the food product and yet maintain the product in an attractive fashion within the container.
Moreover, since the consumer would normally desire that he or she be able to see the food product, the spacing becomes visible to the consumer. The consumer may believe that the package is too large and wasteful. Moreover, if the product is substantially larger than the food product, the food product may move around during transportation and handling, and the package itself may be indented or otherwise damaged.
In the past, deep draw packages may have been used for this type of packaging. However, deep draw packages become difficult to form at large sizes and may experience significant deformation of the packaging material. These packages are particularly susceptible to the formation of thin spots and to the indenting and collapsing of the corner regions.
Thus, the present applicant has appreciated that it would be desirable to form a domed package rather than to use the deep draw plastic forming technique. With the domed package, the product may protrude above the sealing flanges that connect the upper and lower package portions. It is also possible to form the package portions from different materials adapted to particular packaging needs. For example, it may be desirable to form the bottom portion out of foam material and the top out of transparent plastic.
The requirements of a relatively large package made of relatively rigid packaging material seem to be incompatible with the necessity of extra space within the package for conventional gas exchange techniques to extend the shelf life. Thus, most conventional, large food products are simply overwrapped with plastic wrap, and the supermarket endures the additional costs that result from meat loss.
Therefore, it would be highly desirable to provide a relatively rigid domed food package, packaging method, and packaging apparatus which allows relatively large cuts of meat to be efficiently packaged in a desirable gas environment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified cross-sectional view showing three stages in one embodiment of a packaging process in accordance with the present invention;
FIG. 2 is a partial, enlarged, top plan view of the package shown in FIG. 1a;
FIG. 3 is a partial, enlarged, top plan view of the package shown in FIG. 1b;
FIG. 4 is an enlarged, cross-sectional view of one embodiment of a packaging apparatus for accomplishing the process steps shown in FIG. 1b;
FIG. 5 is an enlarged, cross-sectional view of the packaging apparatus of FIG. 4, shown in position to accomplish the process steps shown in FIG. 1c; and
FIG. 6 is an enlarged, top plan view of another embodiment of the package shown in the position illustrated in FIG. 1b.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing wherein like reference characters are used for like parts throughout the several views, a packaging process for packaging a large meat product "A" is shown in FIG. 1 and includes the steps a, b, and c. In step a, the food product "A" is shown contained within a dish-shaped plastic package portion 10 which is supported by a peripheral flange 12 on a member 14.
The package portion 10 may be formed of a variety of conventional materials including any known plastic packaging material. In many instances, it may be desirable to form the lower package portion 10 of molded foamed plastic so that the package portion will be relatively rigid.
Referring to FIG. 1, step b, an upper package portion 18 is shown in spaced relation to the lower package portion 10 over the food product "A". The package portion 18 is domed and includes a peripheral flange 20. Like the package portion 10, the upper package portion 18 may be formed of a variety of conventional plastic materials. However, in many instances, it may be desirable to form the upper package portion 18 out of relatively rigid, molded transparent plastic material. This allows the food product "A" to be viewed within the food package. Advantageously, both the portions 10 and 18 are preformed of relatively rigid, molded plastic material.
As shown in FIG. 1, step c, the upper and lower package portions 18 and 10 may be joined along their peripheral flanges 20 and 12 by an apparatus 22 which presses the flanges 20 of the portion 18 downwardly onto the flanges 12 of the package portion 10. If desired, the apparatus 22 may be a heat seal machine which causes heat sealing of the juxtaposed flange portions thereby connecting the materials.
The advantage of holding the upper domed portions 18 in spaced juxtaposition with the lower portion 10 is that the gaseous environment within the package may be transformed prior to the sealing step c shown in FIG. 1. For example, the air inside the package may be exhausted, and a desired gas may be supplied in its place. The desired gas may be one which is relatively low in oxygen content so that the shelf life of the food product may be extended. For example, the gas may be relatively higher in either carbon dioxide and/or nitrogen than normal atmospheric air in order to prevent or diminish the oxidation processes that shorten the life of the meat product "A".
As shown in FIG. 2, the lower package portion 10 may be maintained in a desired arrangement by a set of two pairs of opposed guides 24. Each of the guides 24 is arranged in a substantially tangential arrangement to the curved sides of the lower package portion 10 so as to abut with the sealing region 26. The sealing region 26 provides the point of attachment to the upper package portion 18. It can also be seen in FIG. 2 that the lower package portion 10 may include an outwardly extending flange portion 28 on either of two opposed ends of the package 10. While the package 10 shown in FIG. 2 has an oblong configuration, the cross-sectional configuration of the package may assume one of a variety of different shapes.
FIG. 3 shows the positioning of the upper package portion 18 over the lower package portion 10. The upper package portion 18 includes a pair of opposed bluntly pointed end flanges 34 which interact with and are constrained between each set of guides 24. The outwardly extending flange portions 34 extend over the tubes 30 such that the tubes 30 do not generally guide the positioning of the upper package portion 18 in the horizontal plane. This accomplished substantially by the guides 24. In the regions 36, the flanges 34 extend past the edges 32 of the flanges 28 so that there is a region of overhang of the flange 34 over the lower package portion 10.
FIG. 4 shows a packaging machine for achieving the package operation shown in FIG. 1b. In order to illustrate that a variety of package shapes may be utilized, the package 38 shown in FIG. 4 is of a slightly different shape than the package shown in FIG. 1. In particular, the lower package portion 10 is deeper than the package portion 10 shown in FIG. 1, and the abruptness of both the lower and the upper package portions 18 and 10 is greater in the embodiment shown in FIG. 4.
The lower package portion 10 rests in a conforming tray 40 which conforms to its outside configuration and supports the flange 12. The upper package portion 18 has its flange portion 36 resting atop the filling tube 30.
The filling tube 30 is reciprocal up and down within a slot 42. However, the extent of its upward extension is controlled by the overhanging edge 44 of the adjacent guide 24. Each tube 30 includes an outer cylinder 30a and an inner cylinder 30b.
The outer cylinder 30a includes a set of "O" rings 46 which prevent leakage around the tube 30. A pin 48 is provided to control the extent of downward movement of the tube 30 and to prevent its rotation about its lengthwise axis. Within the center of the tube 30 is a bore 50 which is capable of conveying gas to or from the interior of the package to or from the passageway 52. Thus, gas may pass via the passageway 52 to or from the interior of the package shown in the configuration of FIG. 4.
A pressurized gas supply passageway 72 is connected to a source (not shown) of pressurized gas. When desired, pressurized gas may be communicated via the passageway 72 to act on the lower end of the outer cylinder 30a. This causes the tube 30 to move to its upper position shown in FIG. 4.
Juxtaposed over the upper package portion 18 is a pusher bar 54 and a sealing bar 56. The sealing bar 56 may be a conventional heat sealing bar which heat seals the flanges of the upper package portion 18 to those of the lower package portion 10.
The vacuum chamber cover 90 seals to the lower chamber 92 through inner and outer peripheral seals 94 and 96 and the abutment of gasket 98 on the lower chamber 92. A valved passage 100 is provided for pulling a vacuum inside the chamber defined by the cover 90.
FIG. 6 shows an alternate embodiment in which a gas exchange system is provided on the upper package portion 18. The gas exchange portion 58 is constructed generally in accordance with the teaching of applicant's co-pending patent application Ser. No. 08/064,700, filed May 20, 1993, hereby expressly incorporated by reference herein. The portion 58 includes one or more holes 60 formed in the package portion 18. These holes are covered by a first circular plastic film layer 62 which may be permeable to atmospheric air. The layer 62 is sealed to the package portion 18 at 64. Attached over the portion 62 is an upper fluid impermeable plastic film 66 which is sealed at 68 to the upper package portion 18. When desired, the layer 66 may be peeled away to allow gas exchange through the lower layer 62 via the holes 60.
The method and apparatus of the present invention may be implemented in the following fashion. The lower package portion 10, loaded into the conforming tray 40, is supported by its flanges 12. Then a meat product "A", if not already loaded, may be loaded inside the package portion 10. Next, the relatively rigid top or upper portion 18 is aligned over the lower package portion 10 but resting on the top of the filling tubes 30 as shown in FIG. 4.
Initially, the air within the package is exhausted through both the passage 100 and the bore 50 to the passageway 52. Then, with the passage 100 closed, a desired gaseous environment is passed through the passageway 52 and the bore 50 into the package. This gaseous environment may be one which is relatively poor in its concentration of oxygen and relatively higher (with respect to normal ambient atmosphere) with respect to its carbon dioxide and/or nitrogen content. The result of such an environment is to extend the shelf life of a meat product. This is because the presence of oxygen causes the meat product to age and discolor.
After the desired environment has been established, the gas filling tubes 30 are pushed downwardly by the pusher bar 54 into their passageways 42 until the pins 48 engage the top of the slots 80. In this position, shown in FIG. 5, the upper package portion 18 is in abutment with the lower package portion 10. At this point, the sealing regions 26 are likewise in abutment. The package is thereafter sealed along the regions 26 of the upper and lower package portions 10 and 18 to provide an air tight seal between the two package portions. This is accomplished through the sealing bar 56 which may, in one advantageous embodiment, cause heat sealing of the components together. The sealing bar 56 reciprocates with the pusher bar 54. However, the pusher bar 54 pushes the tubes 30 below the flanges to insure that, regardless of the package thickness, the tubes 30 do not interfere with the sealing process.
The completed package 38 may be removed by raising the cover 90 with the sealing bar 56 and pusher bar 54. The package 38 may be removed from the conforming carrier 40. This may be accomplished in batch or continuous fashion as desired.
The cycle may be repeated after the gas tubes 30 are reciprocated to their upper position. This is achieved by supplying air pressure to the upper cylinders 30a. The air pressure is released through a relief valve (not shown) when the tubes 30 are pushed downwardly by the pusher bar 54.
The positioning of the upper and lower packaging portions 10 and 18 with respect to one another is assured by the provision of the guides 24 and the filling tubes 30 which interact with the special package shape to ensure exact juxtaposed position of the parts relative to one another. Moreover, the flange portions 36 of the upper package portion 18 maintain the separation of the package when they abut with the filling tubes 30.
Firstly, the lower package portion 10 is inserted into the conforming carrier 40, guided by tubes 30 and guides 24. Then, the upper package portion 18 is located on the tubes 30, positioned by the guides 24. Thereafter, the cover 90 is closed and the process may be repeated.
In many applications, particularly those involving red meat, it may be desirable to withdraw the low oxygen atmosphere from the container at the point of sale. Otherwise, the package with its low oxygen environment will cause the meat to have a purplish color. Thus, in the supermarket, the upper fluid impermeable film 66 may be peeled back. This allows ambient atmosphere to enter the package so that the meat will take on a reddish color.
The provision of the overhang 36 of the upper package portion 18 over the lower package portion 10 facilitates the removal of the domed upper package portion 18 in use. Moreover, the concealed location of the overhang 36 diminishes the possibility of accidental opening.
Thus, it is apparent that there has been provided, in accordance with the invention, a package, a method, and a packaging apparatus that satisfies the aims, objects, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such embodiments, alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims. | A package, packaging method, and packaging apparatus for facilitating the packaging of large meat products and exchanging the ambient atmosphere to establish a desired gaseous atmosphere that extends the shelf life of the product. The package includes a pair of preformed relatively rigid plastic domed or cupped members which abut along a sealing surface. The upper and lower package portions include flanges which are adapted to facilitate not only the formation of the package but its subsequent opening. A reciprocatable filling tube maintains the separation between the upper and lower package portions to permit gas exchange and then may be reciprocated downwardly to allow the upper package portion to abut atop the lower package portion for sealing connection. | 1 |
[0001] This application is a Divisional of Ser. No. 11/160,670, filed Jul. 5, 2005.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to lithographic chemical shrink processes, and more specifically, to improvements to lithographic chemical shrink processes.
[0004] 2. Related Art
[0005] During the fabrication of a semiconductor integrated circuit (IC), contact holes (i.e., openings) are typically formed in a dielectric layer and then filled with metal (e.g., copper) to provide electric accesses to devices of the IC underneath the dielectric layer. In one conventional method, these contact holes can be formed using a traditional photolithographic process. As the contact holes become smaller and smaller in size with, for example, successive technology generations, there is a need for improvements to the traditional photolithographic process for printing (i.e., creating) smaller contact holes.
[0006] Therefore, there is a need for contact hole printing processes that allow printing contact holes relatively smaller than those of the prior art.
SUMMARY OF THE INVENTION
[0007] The present invention provides a structure formation method, comprising providing a structure including (a) a hole layer having a top hole layer surface, (b) a BARC (bottom antireflective coating) layer on the top hole layer surface, and (c) a patterned photoresist layer on top of the BARC layer, wherein the patterned photoresist layer comprises a photoresist hole such that a top BARC surface of the BARC layer is exposed to the surrounding ambient at a bottom wall of the photoresist hole; extending the photoresist hole by removing a portion of the BARC layer directly beneath the bottom wall of the photoresist hole such that an area of the top hole layer surface is exposed to the surrounding ambient via the extended photoresist hole, wherein said extending the photoresist hole is performed before any deposition of any layer on the patterned photoresist layer; and depositing a hole shrinking film (i) on the patterned photoresist layer, (ii) on a side wall of the extended photoresist hole, and (iii) on the bottom wall of the extended photoresist hole after said extending the photoresist hole is performed.
[0008] The present invention also provides structure formation method, comprising providing a structure including (a) a hole layer having a top hole layer surface, (b) an acid containing layer on the top hole layer surface, wherein the acid containing layer comprises acids necessary for a chemical shrink process, and (c) a patterned photoresist layer on top of the acid containing layer, wherein the patterned photoresist layer comprises a photoresist hole such that a top acid containing layer surface of the acid containing layer is exposed to the surrounding ambient at a bottom wall of the photoresist hole; extending the photoresist hole by removing a portion of the acid containing layer directly beneath the bottom wall of the photoresist hole such that an area of the top hole layer surface is exposed to the surrounding ambient via the extended photoresist hole, wherein said extending the photoresist hole is performed before any deposition of any layer on the patterned photoresist layer, and wherein said extending the photoresist hole undercuts the patterned photoresist layer; and depositing a hole shrinking film (i) on the patterned photoresist layer, (ii) on a side wall of the extended photoresist hole, and (iii) on the bottom wall of the extended photoresist hole after said extending the photoresist hole is performed.
[0009] The present invention also provides a structure, comprising (a) a hole layer including a top hole layer surface; (b) a BARC (bottom antireflective coating) layer being on the top hole layer surface and comprising a BARC hole in the BARC layer; (c) a photoresist layer being on top of the BARC layer and being in direct physical contact with the BARC layer via a first common interfacing surface, wherein the photoresist layer comprises a photoresist hole directly above the BARC hole; and (d) a polymerized hole shrinking region in the photoresist hole and the BARC hole, wherein the polymerized hole shrinking region is in direct physical contact with the hole layer.
[0010] The present invention provides contact hole printing processes that allow printing contact holes relatively smaller than those of the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIGS. 1A-1F illustrate the steps of a first contact hole printing process, in accordance with embodiments of the present invention.
[0012] FIGS. 2A-2E illustrate the steps of a second contact hole printing process, in accordance with embodiments of the present invention.
[0013] FIGS. 3A-3F illustrate the steps of a third contact hole printing process, in accordance with embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] FIGS. 1A-1F illustrate the steps of a first contact hole printing process, in accordance with embodiments of the present invention. More specifically, with reference to FIG. 1A , in one embodiment, the first contact hole printing process starts out with a structure 100 including a contact hole layer 110 (comprising a dielectric material such as SiO 2 in one embodiment) to be patterned with contact holes. The contact hole layer 110 is formed on a semiconductor substrate (not shown for simplicity). The structure 100 further comprises (i) a BARC (bottom antireflective coating) layer 120 on top of the contact hole layer 110 and (ii) a photoresist layer 130 on top of the BARC layer 120 .
[0015] Next, in one embodiment, the photoresist layer 130 is exposed to light through a mask (not shown, but typically placed over the photoresist layer 130 ) containing clear and opaque features such that a region 131 of the photoresist layer 130 is exposed to light while other regions of the photoresist layer 130 are not exposed to light, in this case drawn to reflect a positive-tone photoresist. The BARC layer 120 ensures that a substantial portion of light that passes through the photoresist layer 130 is absorbed by the BARC layer 120 without being reflected back to the photoresist layer 130 by any layer(s) beneath the BARC layer 120 (including the contact hole layer 110 ).
[0016] In one embodiment, assume that positive-tone optical lithography is used. In other words, the photoresist layer 130 comprises a positive-tone photoresist material such that regions of the photoresist layer 130 exposed to light change from originally insoluble to soluble in a first photoresist developer (a solvent) while other regions of the photoresist layer 130 not exposed to light remain insoluble in the first photoresist developer. As a result, with reference to FIG. I B, in one embodiment, the first photoresist developer is used to develop away (remove) the exposed-to-light region 131 ( FIG. 1A ) of the photoresist layer 130 (called development process) resulting in a photoresist hole 132 in the patterned photoresist layer 130 .
[0017] It should be noted that when the photoresist layer 130 is exposed to light, the intensity of energy reaching the photoresist layer 130 is at its highest at the center of the region 131 ( FIG. 1A ) and decays at the perimeter of the region 131 ( FIG. 1A ). As a result, a region 139 abutting the region 131 ( FIG. 1A ) does not attain an acid concentration level required for inducing photoresist development. Therefore, when the region 131 ( FIG. 1A ) is later removed, the region 139 remains and contains some photo acids (called residual photo acids).
[0018] Next, in one embodiment, the patterned photoresist layer 130 is used as a blocking mask for directionally (vertically) etching the BARC layer 120 through the photoresist hole 132 so as to extend the photoresist hole 132 further down until a top surface 112 of the SiO 2 contact hole layer 110 is exposed to the surrounding ambient through the photoresist hole 132 as shown in FIG. 1C . In one embodiment, the directional etching of the BARC layer 120 is a RIE (reactive ion etching) process.
[0019] Next, with reference to FIG. 1D , in one embodiment, a hole shrinking film 140 is formed on top of the entire structure 100 of FIG. 1C by, illustratively, a spin-on process such that the hole shrinking film 140 completely fills the photoresist hole 132 and such that the hole shrinking film 140 and the BARC layer 120 have a common surface 135 .
[0020] In one embodiment, the hole shrinking film 140 comprises a material which, when coming into direct contact with the residual photo acids at a high temperature, becomes solid and capable of withstanding a subsequent etching of the BARC layer 120 and the contact hole layer 110 during the formation of a contact hole 114 ( FIG. 1F ) in the contact hole layer 110 . More specifically, in one embodiment, the hole shrinking film 140 comprises a water-soluble polymer (or alcohol-soluble polymer) and can be formed by spin-applying the water-soluble polymer on top of the entire structure 100 of FIG. 1C . Next, the structure 100 is baked to an elevated temperature such that (i) the residual photo acids in the region 139 diffuse into a region 143 of the hole shrinking film 140 via the side wall 133 and (ii) BARC acids in the BARC layer 120 diffuse into a region 145 of the hole shrinking film 140 via the common surface 135 .
[0021] In one embodiment, the acid concentration in the region 139 is smaller than the acid concentration in the BARC layer 120 . As a result, the acid diffusion from the region 139 into the region 143 is at a lower rate than the acid diffusion from the BARC layer 120 into the region 145 resulting in a thickness 143 ′ of the region 143 being smaller than a thickness 145 ′ of the region 145 . In other words, different acid concentrations in the region 139 and the BARC layer 120 results in different acid diffusion rates from the region 139 and the BARC layer 120 into the regions 143 and 145 , respectively. However, it should also be noted that temperature also affects the acid diffusion rates from the region 139 and the BARC layer 120 into the regions 143 and 145 , respectively. For instance, the acids in the region 139 may be more mobile than the acids in the BARC layer 120 upon heating above the glass transition temperature (Tg). Since the BARC is conventionally cross-linked, there is no such transition point in the BARC. In one embodiment, the thicknesses 143 ′ and 145 ′ are controlled by (i) the bake temperature at which the structure 100 is baked and (ii) the duration of the bake step. The higher the bake temperature and the longer the structure 100 is baked, the larger the thicknesses 143 ′ and 145 ′.
[0022] At the elevated temperature, the diffused residual photo acids in the region 143 catalyze cross-linking reactions (i.e., polymerization) in the region 143 causing the region 143 to change from originally soluble to insoluble in a first post-shrink rinse chemical (e.g., water).
[0023] Similarly, at the elevated temperature, the diffused BARC acids in the region 145 catalyze cross-linking reactions (i.e., polymerization) in the region 145 causing the region 145 to change from originally soluble to insoluble in the first post-shrink rinse chemical.
[0024] Next, the first post-shrink rinse chemical is used to the remove the entire hole shrinking film 140 except the insoluble regions 143 and 145 (also referred to as the region 143 , 145 ) such that the photoresist hole 132 is reopened and such that the top surface 112 of the contact hole layer 110 is again exposed to the surrounding ambient through the reopened photoresist hole 132 as shown in FIG. 1E . This process can be referred to as the first post-shrink rinse.
[0025] Next, with reference to FIG. 1F , in one embodiment, the contact hole 114 is formed in the contact hole layer 110 directly beneath and aligned with the reopened photoresist hole 132 . Illustratively, the contact hole 142 is formed by directionally etching (e.g., RIE etching in one embodiment) the contact hole layer 110 through the photoresist hole 132 . In one embodiment, the contact hole 114 is then filled with an electrically conducting material (not shown) such as copper to provide electric access to device(s) (not shown) underneath the contact hole layer 110 .
[0026] FIGS. 2A-2E illustrate the steps of a second contact hole printing process, in accordance with embodiments of the present invention. More specifically, with reference to FIG. 2A , in one embodiment, the second contact hole printing process starts out with a structure 200 including a contact hole layer 210 (comprising a dielectric material such as SiO 2 in one embodiment) formed on a semiconductor substrate (not shown for simplicity). The structure 200 further comprises (i) a BARC (bottom antireflective coating) layer 220 on top of the contact hole layer 210 and (ii) a photoresist layer 230 on top of the BARC layer 220 .
[0027] For simplicity, all reference numerals herein have three numeric digits starting with the numeric figure number. In addition, similar regions have identical reference numerals except for the first digit which is used to indicate the numeric figure number. For example, the BARC layer 120 ( FIG. 1A ) and the BARC layer 220 ( FIG. 2A ) are similar.
[0028] Next, in one embodiment, the photoresist layer 230 is exposed to light through a mask (not shown, but typically projected onto the photoresist layer 230 ) containing clear and opaque features such that a region 231 of the photoresist layer 130 is exposed to light while other regions of the photoresist layer 230 are not exposed to light. The BARC layer 230 optimizes the image quality by suppressing reflections within the resist.
[0029] In one embodiment, assume that positive-tone optical lithography is used. As a result, with reference to FIG. 2B , a second photoresist developer is used to develop away (remove) the exposed-to-light region 231 ( FIG. 2A ) of the photoresist layer 230 (called development process) resulting in a photoresist hole 232 in the patterned photoresist layer 230 .
[0030] It should be noted that when the photoresist layer 230 is exposed to light, the intensity of energy reaching the photoresist layer 230 is at its highest at the center of the region 231 ( FIG. 2A ) and decays at the perimeter of the region 231 ( FIG. 2A ). As a result, a region 239 abutting the region 231 ( FIG. 2A ) does not attain an acid concentration level required for inducing photoresist development. Therefore, when the region 231 ( FIG. 2A ) is later removed, the region 239 remains and contains some photo acids (called residual photo acids).
[0031] In one embodiment, the BARC layer 220 comprises a wet-developable material such that the second photoresist developer which is used to develop the photoresist layer 230 also isotropically etches the BARC layer 220 stopping at the SiO 2 contact hole layer 210 . Alternatively, an isotropic etching of the BARC layer 220 separate from the development of the photoresist layer 230 (i.e., using etchants other than the second photoresist developer) is performed. As a result of the development of the photoresist layer 230 and the subsequent isotropic etching of the BARC layer 220 , a top surface 212 of the contact hole layer 210 is exposed to the surrounding ambient through the photoresist hole 232 . In one embodiment, the isotropic etching of the BARC layer 220 undercuts the photoresist layer 230 as shown in FIG. 2B .
[0032] Next, with reference to FIG. 2C , in one embodiment, a hole shrinking film 240 is formed on top of the entire structure 200 of FIG. 2B by, illustratively, a spin-on process such that the hole shrinking film 240 completely fills the photoresist hole 232 . In one embodiment, the hole shrinking film 240 comprises a water-soluble polymer and can be formed by spin-applying the water-soluble polymer on top of the entire structure 200 of FIG. 2B .
[0033] Next, the structure 200 is baked to an elevated temperature such that (i) the residual photo acids in the region 239 diffuse into a region 243 of the hole shrinking film 240 via the side wall 233 and (ii) BARC acids in the BARC layer 220 diffuse into a region 245 of the hole shrinking film 240 via the common surface 235 .
[0034] In one embodiment, the acid concentration in the region 239 is smaller than the acid concentration in the BARC layer 220 . As a result, the acid diffusion from the region 239 into the region 243 is at a lower rate than the acid diffusion from the BARC layer 220 into the region 245 resulting in a thickness 243 ′ of the region 243 being smaller than a thickness 245 ′ of the region 245 . In one embodiment, the thicknesses 243 ′ and 245 ′ are controlled by (i) the bake temperature at which the structure 200 is baked and (ii) the duration of the bake step. The higher the bake temperature and the longer the structure 200 is baked, the larger the thicknesses 243 ′ and 245 ′.
[0035] In one embodiment, the bake temperature and the duration of the bake step for the structure 200 of FIG. 2B are such that the difference of thicknesses 243 ′ and 245 ′ is equal to the undercut degree 238 ( FIG. 2B ).
[0036] At the elevated temperature, the diffused residual photo acids in the region 243 catalyze cross-linking reactions (i.e., polymerization) in the region 243 causing the region 243 to change from originally soluble to insoluble in a second post-shrink rinse chemical (e.g., water).
[0037] Similarly, at the elevated temperature, the diffused BARC acids in the region 245 catalyze cross-linking reactions (i.e., polymerization) in the region 245 causing the region 245 to change from originally soluble to insoluble in the second post-shrink rinse chemical.
[0038] Next, the second post-shrink rinse chemical is used to the remove the entire hole shrinking film 240 except the insoluble regions 243 and 245 (also referred to as the region 243 , 245 ) such that the top surface 212 of the contact hole layer 210 is again exposed to the surrounding ambient as shown in FIG. 2D . This process can be referred to as the second post-shrink rinse.
[0039] Because the difference of thicknesses 243 ′ and 245 ′ is equal to the undercut degree 238 ( FIG. 2B ), the side wall 234 of the reopened photoresist hole 232 is vertical through out the photoresist layer 230 and the BARC layer 220 .
[0040] Next, with reference to FIG. 2E , in one embodiment, the contact hole 214 is formed in the contact hole layer 210 directly beneath and aligned with the photoresist hole 232 . Illustratively, the contact hole 242 is formed by directionally etching (e.g., RIE etching in one embodiment) the contact hole layer 210 through the photoresist hole 232 . In one embodiment, the contact hole 214 is then filled with a electrically conducting material (not shown) such as copper to provide electric access to device(s) (not shown) underneath the contact hole layer 210 .
[0041] FIGS. 3A-3F illustrate the steps of a third contact hole printing process, in accordance with embodiments of the present invention. More specifically, with reference to FIG. 3A , in one embodiment, the second contact hole printing process starts out with a structure 300 including a contact hole layer 310 (comprising a dielectric material such as SiO 2 in one embodiment) formed on a semiconductor substrate (not shown for simplicity). The structure 300 further comprises (i) a BARC (bottom antireflective coating) layer 320 on top of the contact hole layer 310 and (ii) a photoresist layer 330 on top of the BARC layer 320 .
[0042] Next, in one embodiment, the photoresist layer 330 is exposed to light through a mask (not shown, but typically formed on top of the photoresist layer 330 ) containing clear and opaque features such that a region 331 of the photoresist layer 330 is exposed to light while other regions of the photoresist layer 330 are not exposed to light. The BARC layer 330 ensures that a substantial portion of light that passes through the photoresist layer 330 is absorbed by the BARC layer 330 without being reflected back to the photoresist layer 330 by any layer(s) beneath the BARC layer 330 (including the contact hole layer 310 .
[0043] In one embodiment, assume that positive-tone optical lithography is used. As a result, with reference to FIG. 3B , a third photoresist developer is used to develop away (remove) the exposed-to-light region 331 ( FIG. 3A ) of the photoresist layer 330 (called development process) resulting in a photoresist hole 332 in the patterned photoresist layer 330 .
[0044] It should be noted that when the photoresist layer 330 is exposed to light, the intensity of energy reaching the photoresist layer 330 is at its highest at the center of the region 331 ( FIG. 3A ) and decays at the perimeter of the region 331 ( FIG. 3A ). As a result, a region 339 abutting the region 331 ( FIG. 3A ) does not attain an acid concentration level required for inducing photoresist development. Therefore, when the region 331 ( FIG. 3A ) is later removed, the region 339 remains and contains some photo acids (called residual photo acids).
[0045] In one embodiment, the BARC layer 320 comprises a wet-developable material such that the second photoresist developer which is used to develop the photoresist layer 330 also isotropically etches the BARC layer 320 stopping at the SiO 2 contact hole layer 310 . Alternatively, an isotropic etching of the BARC layer 320 separate from the development of the photoresist layer 330 (i.e., using etchants other than the third photoresist developer) is performed. As a result of the development of the photoresist layer 330 and the subsequent isotropic etching of the BARC layer 320 , a top surface 312 of the contact hole layer 310 is exposed to the surrounding ambient through the photoresist hole 332 . In one embodiment, the isotropic etching of the BARC layer 320 undercuts the photoresist layer 330 as shown in FIG. 3B .
[0046] Next, with reference to FIG. 3C , in one embodiment, the photoresist layer 330 is thermally reflowed at a reflow temperature in a range of 100 - 200 ° C in a duration in a range of 60 - 90 seconds such that some material of the photoresist layer 330 flows down under the force of gravity and covers the BARC layer 320 . The heat of the flow process not only generates acids through out the patterned photoresist layer 330 but also uniformly redistributes the residual photo acids from the region 339 ( FIG. 3B ) throughout the patterned photoresist layer 330 .
[0047] Next, with reference to FIG. 3D , in one embodiment, a hole shrinking film 340 is formed on top of the entire structure 300 of FIG. 3C by, illustratively, a spin-on process such that the hole shrinking film 340 completely fills the photoresist hole 332 . In one embodiment, the hole shrinking film 340 comprises a water-soluble polymer and can be formed by spin-applying the water-soluble polymer on top of the entire structure 300 of FIG. 3C .
[0048] Next, the structure 300 is baked to an elevated temperature such that the acids in the region 339 diffuse into a region 343 of the hole shrinking film 340 via the side wall 333 and such that BARC. At the elevated temperature, the diffused acids in the region 343 catalyze cross-linking reactions (i.e., polymerization) in the region 343 causing the region 343 to change from originally soluble to insoluble in a third post-shrink rinse chemical (e.g., water).
[0049] Next, the third post-shrink rinse chemical is used to the remove the entire hole shrinking film 340 except the insoluble regions 343 such that the photoresist hole 332 is reopened and such that the top surface 312 of the contact hole layer 310 is again exposed to the surrounding ambient through the reopened photoresist hole 332 as shown in FIG. 3E . This process can be referred to as the third post-shrink rinse.
[0050] Next, with reference to FIG. 3F , in one embodiment, the contact hole 314 is formed in the contact hole layer 310 directly beneath and aligned with the photoresist hole 332 . Illustratively, the contact hole 314 is formed by directionally etching (e.g., RIE etching in one embodiment) the contact hole layer 310 through the photoresist hole 332 . It should be noted that the region 343 not only covers the side wall of the photoresist hole 332 but also covers the top surface of the photoresist layer 330 . As a result, the photoresist layer 330 is better protected from the etching of the contact hole layer 310 during the formation of the contact hole 314 . In one embodiment, the contact hole 314 is then filled with a electrically conducting material (not shown) such as copper to provide electric access to device(s) (not shown) underneath the contact hole layer 310 .
[0051] In the embodiments described above, the first, second, and third contact hole printing processes are used to print contact holes 114 , 214 , and 314 of FIGS. 1F, 2E , and 3 F, respectively. In general, any hole (not just contact holes) of any size and shape can be printed in the layers 110 , 210 , and 310 of FIGS. 1 F, 2E , and 3 F, using the first, second, and third contact hole printing processes, respectively. For instance, with reference to FIGS. 1A-1F , if a the hole 114 having a shape of a long trench needs to be printed in the layer 110 , the photoresist hole 132 needs to have the shape of a long trench.
[0052] While particular embodiments of the present invention have been described herein for purposes of illustration, many modifications and changes will become apparent to those skilled in the art. Accordingly, the appended claims are intended to encompass all such modifications and changes as fall within the true spirit and scope of this invention. | A structure and a method for forming the same. The method comprises providing a structure including (a) a hole layer, (b) a BARC (bottom antireflective coating) layer on the top of the hole layer, and (c) a patterned photoresist layer on top of the BARC layer and having a photoresist hole; etching the BARC layer through the photoresist hole to extend the photoresist hole to the hole layer; performing the chemical shrinking process to shrink the extended photoresist hole; and etching the hole layer through the shrunk, extended photoresist hole so as to form a hole in the hole layer. | 8 |
CLAIM OF PRIORITY
This application is a utility filing of the provisional application U.S. patent application Ser. No. 60/343,181 filed on Dec. 31, 2001, the entire contents of which are hereby incorporated by reference.
TECHNICAL FIELD
This invention relates to a coupling for servicing a pressurized system.
BACKGROUND
Servicing couplings are commonly employed to facilitate charging and evacuation of pressurized fluid systems, such as refrigeration systems, air conditioning systems, or hydraulic systems. The service coupling connects to a service port of the system. The service coupling opens a service port of a system, allowing fluids, including liquids or gases, to be exchanged with the system. A quick-release interconnection between the service port and the service adapter can facilitate the servicing process. For example, when servicing a refrigeration or air conditioning system the service coupling can be connected by a flexible hose to a refrigerant supply source, such as a pressurized bottle or cylinder. When the service coupling and service port is opened, refrigerant can flow through the coupling and into the refrigeration system. Because pressurized fluid systems can be serviced when the system is installed in a confined space such as a vehicle, service couplings having small dimensions can be useful for convenient servicing.
SUMMARY
In one aspect, a service device includes a body having a first end engagable with a service port, a second end engagable with a service unit, and an inner surface defining an interior chamber. The device includes a valve opening member disposed in the interior chamber, and a service port opening member configured to rotate the valve opening member relative to the body, the first end and the second end being in fluid communication when a service port is engaged with the first end and the service port is opened.
The valve opening member can include a plug engaging end proximate to the first end, the plug engaging end being capable of changing position relative to the first end.
The device can also include a spring within the body, biasing the valve opening member toward the first end, and a sealing gasket between the body and the first end. The first end can be capable of forming a seal with the port when the first end is engaged with the service port. The plug engaging end can have a cross section having a substantially hexagonal shape. The body can be a portion of a coupling device. The first end can be engagable with a refrigerant port.
The device can include a valve member within the body having a first position oriented closer to the first end relative to a second position, the valve member moving from the first position to the second position when the service port is engaged with the first end of the body and the service port is opened. The first end can be in fluid communication with the second end when the valve member is in the second position. The valve member can be slideably disposed on a surface of the service port opening member.
The device can be a coupling member. An air conditioning or refrigeration service device can include a service unit including the coupling member.
In another aspect, a method of opening a service port includes adjusting a position of a valve opening member relative to a first end of a service port connector, and opening a valve within the service port. The valve opening member can include a plug engaging end proximate to the first end. The service port connector can be attached to a service unit or can be capable of attaching to a service unit and the first end can be engagable with the service port. The valve opening member can rotate relative to the body to open the valve. Adjusting can take place upon attaching the service port connector to the service port. The method can also include sealing the connector to the port prior to opening the valve. Opening the valve can actuate a valve member within the connector to bring a first end of the connector and a second end of the connector into fluid communication.
The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1A is a sectional view of a service coupling.
FIG. 1B is a sectional view of an engagement member of the service coupling along the line 1 B— 1 B of FIG. 1 A.
FIG. 2 is a sectional view of a service port.
FIG. 3 is a sectional view of the service coupling connecting to a service port.
FIG. 4 is a sectional view of the service coupling connected to the service port.
FIG. 5 is a sectional view of the service coupling opening the service port.
DETAILED DESCRIPTION
Referring to FIG. 1A , a service coupling 100 includes a mating portion 110 for coupling to a service port, a port 120 , and a flow path control portion 130 that allows an operator to control a fluid flow path between mating portion 110 and port 120 .
Port 120 can be attached to service equipment to connect the equipment to the service port. For example, the service port can be a service port of an automotive air conditioning system and the service equipment can include any sort of maintenance or repair system, such as a diagnostic tester, fluorescent leak detection system (i.e., dyes, injection system, lights), electronic leak detection system, recovery and recycling machine radiator service device, refrigerant identification tester, a flushing system, an oil insertion system, or a manifold gauge set.
Service coupling 100 is formed by a main body member 140 , a flow path control portion 130 , a knob 260 , and a port nozzle 125 .
Main body member 140 is generally tubular in shape and has an outer surface 148 , an inner surface 146 , a first end 141 , and a second end 149 opposite first end 141 . End 141 of main body member 140 defines hole 144 dimensioned to receive ball bearing 320 . Ball bearing 320 is retained in hole 144 by an annular ring 310 which surrounds a portion of outer surface 148 . Ball bearing 320 is arranged to engage a service port when inserted into mating portion 110 .
Annular ring 310 includes an inner face 313 with an interior annular lip 314 having a raised portion 315 . Interior annular lip 314 has a lip wall 12 . Inner face 313 and outer surface 148 of main body member 140 , along with lip wall 12 and a lateral wall 143 on outer surface 148 of main body member 140 , together define an annular volume 340 which houses a spring 330 . Spring 330 biases lip wall 12 away from lateral wall 143 so that annular ring 310 contacts retaining ring 302 and is compressible toward lateral wall 143 to allow ball bearings 320 to project into notch 301 from channels 144 thereby releasing a service port received in mating portion 110 .
Inner surface 146 at end 141 of main body member 140 defines a chamber 410 for receiving a service port into mating portion 110 . Inner surface 146 also defines an annular groove 147 around chamber 410 for receiving a sealing member 184 which seals to a service port when received in mating portion 110 . In addition to inner surface 146 , chamber 410 is bounded by a central body member 220 and a valve member 170 .
Central body member 220 is also generally tubular in shape and has an outer surface 228 , an inner surface 226 , a first end 221 , and a second end 229 opposite first end 221 . Central body member 220 defines a volume 230 and channels 231 , 232 that communicate between outer surface 228 and inner surface 226 . Central body member 220 also includes a lateral wall 225 that extends inner surface 226 into axial volume 230 . Orifice 233 located at end 229 extends from volume 230 to outer surface 228 .
Axial volume 230 contains an elongate engagement member 150 that extends into chamber 410 . Engagement member 150 has a first end 151 , a second end 159 opposite first end 151 , and a wall 156 including a pair of opposing lateral slots 154 (only one is shown) and an axial channel 155 extending from first end 151 to second end 159 . Lateral slots 154 have a first end 152 and a second end 158 . Pin 160 is contained between first end 152 and second end 158 in slots 154 , and traverses laterally through engagement member 150 . Pin 160 is mechanically joined to central body member 220 . Engagement member 150 is slidable along pin 160 , allowing relative axial movement between member 220 and engagement member 150 over the span between first end 152 and second end 158 . Pin 160 can also transmit torque from handle 260 , through member 220 to engagement member 150 . Spring 190 is contained in axial volume 230 between lateral wall 225 of central body member 220 and end 159 of engagement member 150 , biasing engagement member 150 toward mating portion 110 . Spring 190 allows engagement member 150 to be driven into axial volume 230 during insertion of a service port into chamber 410 if engagement member 150 is not aligned properly with the service port, as discussed further below in regard to FIG. 2 .
Annular valve member 170 is also generally tubular in shape and has an outer surface 178 , an inner surface 176 , a first end 171 , and a second end 179 opposite first end 171 . Inner surface 176 defines an annular groove 17 for receiving a sealing member 250 to seal valve member 170 to outer surface 228 of central member 220 . Annular valve member 170 defines channels 174 which span between outer surface 178 and inner surface 176 . Fixed seal 240 is attached to surface 146 and forms a releasable seal between surface 146 and surface 178 . Annular valve member 170 also includes an outwardly extending lip 177 contacting a spring 180 circumscribing outer surface 178 of annular valve member 170 and outer surface 228 of central member 220 but within inner surface 146 of main body member 140 . Spring 180 biases annular valve member 170 to form the seal between surface 178 and surface 146 . Annular valve member 170 is slidable along outer surface 228 of central member 220 . When member 170 slides away from the mating region 110 , for example, when coupled to a service port as described below, the releasable seal formed between fixed seal 240 and inner surface 146 to form a fluid flow path from chamber 410 through channels 174 to channel 126 of port nozzle 125 , which, in turn, is in fluid communication with orifice 127 of port nozzle 125 .
Flow path control portion 130 includes knob 260 , which as describe above, applies torque to engagement member 150 by rotating inner knob 280 . Inner knob 280 is fixed to central body member 220 . Outer ratchet teeth 264 of knob 260 contact and mate with inner ratchet teeth 224 of inner knob 280 . Gasket 200 is located between knob 260 and knob 280 over orifice 233 . Gasket 200 is secured to knob 260 by fastener 210 and fastener 212 . Spring 291 , which is located between inner knob 260 and holding plate 290 , biases knob 260 toward mating portion 110 . This bias holds ratchet teeth 264 in contact with ratchet teeth 224 . Biasing of knob 260 toward mating portion 110 by spring 291 also forms a seal between gasket 200 and orifice 233 .
When knob 260 is rotated in a direction that opens an engaged service port (for example, a counter-clockwise direction when knob 260 is viewed from above), a surface of ratchet teeth 264 presses against a surface of ratchet teeth 224 in an orientation parallel to the axis of rotation. This configuration allows all torque applied to knob 260 to be applied to member 150 when opening the service port because no slipping occurs between knob 260 and inner knob 280 . When knob 260 is rotated in a direction that closes an engaged service port (for example, a clockwise direction when knob 260 is viewed from above), a surface of ratchet teeth 264 presses against a surface of ratchet teeth 224 in an orientation that is not parallel to the axis of rotation. This configuration allows slippage to occur when the torque applied to knob 260 overcomes friction between the surface of ratchet teeth 264 and ratchet teeth 224 when closing the service port, thereby avoiding application of a potentially damaging force to the service port. The friction can be influenced by spring 291 . When slippage occurs, knob 260 moves away from member 220 , allowing the seal between gasket 200 and orifice 233 to break during the slippage.
Referring to FIG. 1B , wall 156 of engagement member 150 forms a hexagonal cross-section circumscribing axial channel 155 for engaging and rotating a service port received in mating portion 110 .
Referring to FIG. 2 , a service port 500 includes a body 550 and a plug 600 . Body 550 includes a conduit portion 558 for conducting fluid and a mating portion 552 for connecting to service coupling 100 . Conduit portion 558 includes a wall 556 defining a fluid channel 560 . Mating portion 552 is generally tubular and has an end 559 , an outer surface 557 , and an inner surface 556 . Mating portion 552 is joined to conduit portion 558 . Outer surface 557 can form a seal with sealing member 184 of coupling 100 , as discussed further below. Inner surface 556 defines a chamber 510 and includes a threaded portion 554 . When port 500 is assembled, chamber 510 receives plug 600 . Plug 600 is generally tubular in shape and includes a wall 620 with a first end 621 , a second end 629 , an outer surface 628 , and an inner surface 626 . End 621 of plug 600 is capped by a conical tip portion 610 . Tip portion 610 includes an outer sloped surface 604 extending away from end 621 . Outer surface 628 of wall 620 has a thread 624 are dimensioned to threadedly mate with threaded portion 554 of inner surface 556 of body 550 . End 621 includes orifice 630 penetrating wall plug 600 . In a closed position (as shown), tip portion 610 extends into fluid channel 560 and sloped surface 604 of tip portion 610 seals with wall 556 of fluid channel 560 at contact region 700 . Inner surface 626 defines cavity 611 , which can be hexagonal in cross-section and dimensioned to snugly receive engagement member 150 so that rotation of engagement member 150 can impart a rotational force to sealing member 600 and move sealing member 600 along threads 555 to open and close service port 500 . In the closed position, radial seal 700 prevents fluid communication between fluid channel 560 and chamber 510 . In an open position (not shown), contact in region 700 is broken bringing chamber 510 and channel 560 into fluid communication through orifice 630 .
Referring to FIG. 3 , in use, an operator inserts end 559 of service port 500 into mating portion 110 and chamber 410 of service coupling 100 . Sealing member 184 seals outer surface 557 of service port 500 to inner surface 146 of main body member 140 . Ball 320 engages with outer surface 557 , holding port 500 in coupling 100 . Cavity 611 is dimensioned to receive engagement member 150 , each of which can have a hexagonal cross section. However, at the time of insertion, the cavity 611 of plug 600 may not be properly oriented to receive engagement member 150 , in which case end 151 of engagement member 150 catches on end 629 of plug 600 . As a result, end 629 forces engagement member 150 into volume 230 , compressing spring 190 . Slots 154 accommodate the inward movement of engagement member 150 as member 150 slides along pin 160 from first end 152 to second end 158 . The movement of member 150 allows coupling 100 to mate with port 500 without damaging the coupling or the port.
Referring to FIG. 4 , with service port 500 in chamber 410 of service coupling 100 , the operator manually commences rotating knob 260 . Knob 260 is mechanically joined to pin 160 , which also commences rotation about axis A. The rotation of pin 160 in turn rotates engagement member 150 to align the cross-sectional pattern of member 150 with the cross-sectional pattern of cavity 611 . When the cross-sectional patter of member 150 is aligned with the cross-sectional pattern of cavity 611 , spring 190 slides member 150 along slot 154 and pin 160 and into cavity 611 to engage plug 600 , thereby coupling plug 600 and knob 260 for combined rotation.
Referring to FIG. 5 , once member 150 is engaged with plug 600 , as described above, rotation of plug 600 using knob 260 moves plug 600 along threads 555 of service port body 550 , separating sloped surface 604 from wall 556 and opening service port 500 . As plug 600 is rotated, engagement member 150 extends progressively deeper into cavity 611 and tip 610 progressively withdraws from fluid channel 560 to place fluid channel 560 in communication with the fluid path formed by channel 155 and volume 230 . As plug 600 moves along member 150 , end 629 of plug 600 contacts end 171 of valve member 170 and slides valve member 170 toward knob 260 along central member 220 . As member 170 slides toward knob 260 , the seal between surface 178 and surface 146 at fixed seal 240 breaks, allowing volume 230 and channel 126 to fluidly communicate via channels 231 , 232 . Valve member 170 detects the presence plug 600 and the opening of the service port and moves toward knob 260 to form an uninterrupted fluid flow path from fluid channel 560 , through channel 155 and volume 230 to channel 126 in port nozzle 125 . With this arrangement, the operator will not be able to break the seal at a fixed seal 240 until service port 500 is received in chamber 410 of service coupling 100 and service port 500 has been broken when the port is opened. As described above, when knob 260 is rotated in a direction that closes an engaged service port, a surface of ratchet teeth 264 presses against a surface of ratchet teeth 224 in an orientation that is not parallel to the axis of rotation, allowing slippage to occur and causing the seal between gasket 200 and orifice 233 to break during the slippage. The slippage occurs when plug 600 has been rotated to the closed position. The breaking of the seal between gasket 200 and orifice 233 that occurs once plug 600 has been rotated to the closed position allows pressure within the coupling to be equalized with the ambient environment.
A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. | A service device connects to a service port of a pressurized system. The device includes a valve opening member for opening a valve within the port. The device can attach to a service unit for servicing the pressurized system. The system can be an air conditioning or refrigeration system. | 8 |
TECHNICAL FIELD
[0001] The present invention relates to plating work performed on an inner surface of a casing in manufacturing a rotary machine.
[0002] Priority is claimed on Japanese Patent Application No. 2012-288536, filed on Dec. 28, 2012, the contents of which are incorporated herein by reference.
BACKGROUND ART
[0003] For example, a rotary machine such as a centrifugal compressor or a turbine is provided with a casing that covers rotating bodies such as a rotary shaft and a blade set from an outer circumference side. Since an interior of the casing is exposed to a working fluid, plating is carried out on an inner surface of the casing as a measure against anticorrosion, for instance, when the working fluid is carbon dioxide
[0004] Here, such plating work is typically done by immersing the casing in a plating liquid in a plating tank. Accordingly, a plating tank that has a large volume and is appropriate for the dimensions of the casing of the rotary machine is currently required, which inevitably leads to higher costs.
[0005] Incidentally, a plating method of sending a plating liquid into an interior of a long pipe under pressure and plating an inner surface of the long pipe without using a plating tank is disclosed in Patent Literature 1.
CITATION LIST
Patent Literature
Patent Literature 1
[0006] Japanese Unexamined Patent Application, First Publication No. H08-319576
SUMMARY OF INVENTION
Technical Problem
[0007] However, if the plating method of Patent Literature 1 is used, no plating tank is required, which leads to a reduction of costs. However, in addition to the fact that the dimensions are very large, the casing also has a complicated shape. Therefore, when application of the method of Patent Literature 1 to the plating work for the inner surface of the casing of the rotary machine is attempted, a huge device is required, and the plating work is not easy.
[0008] An object of the present invention is to provide a method of manufacturing a rotary machine, a method of plating the rotary machine, and the rotary machine, all of which enables plating work for a casing using a simple technique while reducing costs.
Solution to Problem
[0009] A method of manufacturing a rotary machine according to a first aspect of the present invention includes: a casing forming process of forming a casing of the rotary machine that has multiple opening parts and suctions and discharges a fluid; a surface activating process of supplying a pretreatment liquid into the casing, then discharging the pretreatment liquid from the casing through the opening parts, and activating an inner surface of the casing after the casing forming process; a plating process of performing supply and discharge of a plating liquid into and from the casing through the opening parts to circulate the plating liquid and plating the inner surface of the casing after the surface activating process; and an assembling process of providing a rotating body that is rotatable relative to the casing so as to be covered from an outer circumference side by the casing plated in the plating process.
[0010] According to this method of manufacturing the rotary machine, the inner surface of the casing is activated from the opening parts formed in the casing by the pretreatment liquid. Further, plating work is performed by circulation of the plating liquid. Since the multiple opening parts for suctioning and discharging the liquids are formed in the casing, the supply and discharge of the pretreatment liquid and the plating liquid can be performed using the multiple opening parts with no change in the surface activating process and the plating process. Accordingly, separate nozzles for supplying and discharging the pretreatment liquid and the plating liquid are not provided, and a plating tank for immersing the entire casing is not required either. As such, the plating work for the inner surface of the casing is possible.
[0011] Further, a method of manufacturing a rotary machine according to a second aspect of the present invention may further include a preheating process of
[0012] supplying a pretreatment liquid into the casing, then discharging the pretreatment liquid from the casing through the opening parts, and preheating the casing between the surface activating process and the plating process in the first aspect.
[0013] Because this preheating process is provided, the plating tank for immersing the entire casing is not required, and the preheating before the plating work can be performed using the opening parts. Particularly, in the casing having a large size and a complicated shape, it takes time to raise a temperature by circulating the plating liquid. Further, an uneven temperature may be caused on the inner surface of the casing by partial immersion of the plating liquid. For this reason, it may be impossible to obtain a sufficient quality of plating. Due to the preheating liquid, such a problem can be avoided, and a quality of plating can be further improved.
[0014] Further, in a method of manufacturing a rotary machine according to a third aspect of the present invention, the casing in the preheating process in the second aspect may be preheated by a preheating liquid containing a reductant as the preheating liquid.
[0015] The preheating liquid containing such a reductant is used, and thereby it is possible to prevent an oxide thin film from forming at the inner surface of the casing which is a portion to be plated during the preheating. That is, the oxidation of the inner surface of the casing can be prevented, and the quality of plating can be further improved in the plating process.
[0016] Further, in a method of manufacturing a rotary machine according to a fourth aspect of the present invention, the plating liquid supplied into the casing in the plating process in any one of the first to third aspects may be stirred by a stirring device.
[0017] This stirring device is used, and thereby even in the casing having a large size and a complicated shape, a flow velocity of the plating liquid in the casing can be set to a numerical value most suitable for plating work. Further, by removing a gas that is generated during the plating work and is attached to the inner surface of the casing, it is possible to prevent the plating work from being obstructed at portions at which the gas is attached. Therefore, the quality of plating can be further improved in the plating process.
[0018] Further, in a method of manufacturing a rotary machine according to a fifth aspect of the present invention, in the plating process in any one of the first to fourth aspects, the plating may be performed in a state in which the opening part having a largest opening among the multiple opening parts is directed upward.
[0019] Thereby, the gas that is generated during the plating work and is attached to the inner surface of the casing can be easily discharged outside the casing. Therefore, the quality of plating can be further improved in the plating process.
[0020] Further, in a method of manufacturing a rotary machine according to a sixth aspect of the present invention, the plating liquid in the plating process in any one of the first to fifth aspects may be supplied and discharged from the opening part that requires plating work and suctions and discharges the fluid among the multiple opening parts.
[0021] Thereby, when the plating liquid is supplied and discharged, an inner surface of the opening part requiring the plating work can be plated at the same time. For this reason, the plating work can be performed on the casing in a more efficient way.
[0022] Further, in a method of manufacturing a rotary machine according to a seventh aspect of the present invention, in the plating process in any one of the first to sixth aspects, the plating may be performed in a state in which a cover member surrounding an opening edge of the opening part from an outer circumference side is provided for the casing so as to cause the opening part opened upward among the multiple opening parts to further extend in an upward direction.
[0023] Due to such a cover member, a liquid level of the plating liquid supplied into the casing can be at a higher position than the upper opening part. For this reason, the plating work can be performed up to an opening edge of the opening part, and the plating work can be reliably performed on the entire inner surface of the casing. Therefore, the quality of plating is further improved.
[0024] Further, in a method of manufacturing a rotary machine according to an eighth aspect of the present invention, in the plating process in any one of the first to seventh aspects, the plating may be performed after a core is installed in the casing in a state in which the core is spaced apart from an inner surface of the casing.
[0025] Because such a core is provided, an internal volume of the casing can be reduced, and a supplied amount of the plating liquid can be reduced, which leads to a reduction of costs. Further, a flow channel when the plating liquid circulates and flows in the casing is reduced, and a flow can be made smooth. Therefore, the quality of plating can be improved.
[0026] Further, in a method of manufacturing a rotary machine according to a ninth aspect of the present invention, in the plating process in the eighth aspects, a hollow member having through-holes that are formed in an outer circumferential surface thereof and communicate with an interior and exterior thereof may be used as the core, and the plating liquid may be supplied into the hollow member and be ejected from the through-holes toward an exterior of the hollow member.
[0027] Because the core of such a hollow member is used, the flow channel when the plating liquid circulates and flows in the casing is reduced, and the flow can be made smooth. Further, the plating liquid is ejected from the through-holes, and thereby a stirring effect can also be obtained. Accordingly, it is possible to make the flow velocity of the plating liquid in the casing uniform, and to remove the gas that is generated during the plating work and is attached to the inner surface of the casing. Therefore, the quality of plating can be improved in the plating process.
[0028] Further, in a method of manufacturing a rotary machine according to a tenth aspect of the present invention, in the plating process in the eighth or ninth aspect, the plating may be performed while moving the core.
[0029] Thereby, it is possible to obtain an effect of stirring the plating liquid, to optimize the flow velocity of the plating liquid, and to remove the gas. Therefore, the quality of plating can be further improved in the plating process.
[0030] Further, in a method of manufacturing a rotary machine according to an eleventh aspect of the present invention, in the plating process in any one of the first to tenth aspects, the plating may be performed in a state in which a partition plate for partitioning an interior of the casing into multiple spaces in an extending direction of the casing is provided such that at least two of the opening parts communicate with the respective spaces.
[0031] Thereby, the internal space of the casing in which the plating liquid circulates can be finely divided, and the plating liquid can flow through each space. Therefore, fluidity of the plating liquid in the casing can be improved, and the quality of plating can be improved.
[0032] Further, in a method of manufacturing a rotary machine according to a twelfth aspect of the present invention, in the plating process in any one of the first to eleventh aspects, the plating may be performed while vibration is imparted to the casing by a vibration imparting device.
[0033] Thereby, it is possible to prevent retention of the gas that is generated during the plating work and is attached to the inner surface of the casing. As such, the quality of plating can be further improved in the plating process.
[0034] Further, in a method of manufacturing a rotary machine according to a thirteenth aspect of the present invention, in the plating process in any one of the first to twelfth aspects, the plating may be performed while the inner surface of the casing is rubbed by a brush.
[0035] Thereby, it is possible to prevent retention of the gas that is generated during the plating work and is attached to the inner surface of the casing, and to further improve the quality of plating in the plating process.
[0036] Further, a rotary machine according to a fourteenth aspect of the present invention is manufactured by the method according to any one of the first to thirteenth aspects.
[0037] According to this rotary machine, the supply and discharge of the pretreatment liquid and the plating liquid can be performed using the multiple opening parts with no change in the surface activating process and the plating process. Accordingly, the separate nozzles for supplying and discharging the pretreatment liquid and the plating liquid are not provided. Further, as the plating tank for immersing the entire casing is not required either, the plating work for the inner surface of the casing is possible.
[0038] Further, a method of plating a rotary machine according to a fifteenth aspect of the present invention includes, to plate an inner surface of a casing of the rotary machine that has multiple opening parts and suctions and discharges a fluid, a surface activating process of supplying and discharging a pretreatment liquid into and from the casing through the opening parts and activating the inner surface of the casing, and a plating process of performing supply and discharge of a plating liquid into and from the casing through the opening parts to circulate the plating liquid and plating the inner surface of the casing after the surface activating process.
[0039] According to this method of plating the rotary machine, the separate nozzles for supplying and discharging the pretreatment liquid and the plating liquid are not provided. Further, as the plating tank for immersing the entire casing is not required, the plating work for the inner surface of the casing is possible.
[0040] Further, a rotary machine according to a sixteenth aspect of the present invention is manufactured by the method according to the fifteenth aspect.
[0041] According to this rotary machine, the rotary machine can be manufacture by the plating method of performing the plating work on the inner surface of the casing while the separate nozzles for supplying and discharging the pretreatment liquid and the plating liquid are not provided, and the plating tank for immersing the entire casing is not required.
Advantageous Effects of Invention
[0042] According to the method of manufacturing a rotary machine, the method of plating the rotary machine, and the rotary machine, the pretreatment liquid and the plating liquid are supplied and discharged using the opening parts formed in the casing. Thereby, a cost can be reduced, and plating work of the casing can be performed by a simple technique.
BRIEF DESCRIPTION OF DRAWINGS
[0043] FIG. 1 is a schematic cross-sectional view illustrating a centrifugal compressor manufactured by a method of manufacturing the centrifugal compressor according to a first embodiment of the present invention.
[0044] FIG. 2 is a flow chart illustrating a procedure of the method of manufacturing the centrifugal compressor according to the first embodiment of the present invention.
[0045] FIG. 3 is a perspective view illustrating an aspect of carrying out plating on a casing using the method of manufacturing the centrifugal compressor according to the first embodiment of the present invention.
[0046] FIG. 4 is a perspective view illustrating an aspect of carrying out plating on a casing using a method of manufacturing a centrifugal compressor according to a second embodiment of the present invention.
[0047] FIG. 5 is a perspective view illustrating an aspect of carrying out plating on a casing using a method of manufacturing a centrifugal compressor according to a third embodiment of the present invention.
[0048] FIG. 6 is a perspective view illustrating an aspect of carrying out plating on a casing using a method of manufacturing a centrifugal compressor according to a fourth embodiment of the present invention.
[0049] FIG. 7 is a perspective view illustrating an aspect of carrying out plating on a casing using a method of manufacturing a centrifugal compressor according to a fifth embodiment of the present invention.
[0050] FIG. 8 is a perspective view illustrating an aspect of carrying out plating on a casing using a method of manufacturing a centrifugal compressor according to a sixth embodiment of the present invention.
[0051] FIG. 9 is a perspective view illustrating an aspect of carrying out plating on a casing using a method of manufacturing a centrifugal compressor according to a seventh embodiment of the present invention.
[0052] FIG. 10A is a view illustrating the aspect of carrying out the plating on the casing using the method of manufacturing a centrifugal compressor according to the fifth embodiment of the present invention when the casing is obliquely viewed from the inside.
[0053] FIG. 10B is a view illustrating the aspect of carrying out the plating on the casing using the method of manufacturing a centrifugal compressor according to the fifth embodiment of the present invention when the casing is viewed from the outside.
DESCRIPTION OF EMBODIMENTS
First Embodiment
[0054] Hereinafter, a method of manufacturing a centrifugal compressor (rotary machine) 100 according to a first embodiment of the present invention will be described.
[0055] The centrifugal compressor 100 manufactured by the present embodiment is a device that takes in a fluid F, circulates the fluid F along an axis O, and thereby raises a pressure of the fluid F.
[0056] As illustrated in FIG. 1 , the centrifugal compressor 100 includes a casing 1 having a cylindrical shape, an internal casing 2 that is adapted to be covered from an outer circumference side thereof by the casing 1 and is provided so as not to be relatively rotatable with respect to the casing 1 , a rotary shaft (rotating body) 3 and an impeller (rotating body) 4 that are covered from an outer circumference side thereof by the internal casing 2 and are provided so as to be relatively rotatable with respect to the internal casing 2 .
[0057] The rotary shaft 3 has a columnar shape whose center is an axis O, and extends in a direction of the axis O. Further, the impeller 4 has multiple stages that are fit onto the rotary shaft 3 at predetermined intervals in the direction of the axis O and are rotated about the axis O along with the rotary shaft 3 .
[0058] The internal casing 2 supports the rotary shaft 3 and the impeller 4 . Further, a channel (not shown) is formed between the stages of the impeller 4 in the internal casing 2 , and the fluid F is gradually circulated from the foremost stage to the rearmost stage of the impeller 4 via the channel and is increased in pressure.
[0059] The casing 1 has a cylindrical shape whose center is the axis O and in which an upstream opening part 10 of one side in the direction of the axis O (left side in the space of FIG. 1 ) and a downstream opening part 11 of the other side are formed, and takes an external form of the centrifugal compressor 100 . In the present embodiment, the casing 1 is shaped to protrude toward a radial inner side of the axis O in an annular shape at an end of one side in the direction of the axis O. Thereby, in comparison with the downstream opening part 11 , the upstream opening part 10 is adapted to have a smaller diameter.
[0060] The casing 1 has an intake port (opening part) 5 of the fluid F which is provided at the end of one side serving as an upstream side in the direction of the axis O, and a discharge port (opening part) 6 of the fluid F which is provided at the end of the other side so as to protrude from an outer circumferential surface thereof toward a radial outer side of the axis O. In the present embodiment, the casing 1 is one cylindrical member without a division plane.
[0061] The intake port 5 is formed with an intake channel FC 1 that passes through the casing 1 in a radial direction of the axis O so as to communicate with the interior and exterior of the casing 1 . The intake channel FC 1 is adapted to communicate with an interior of the foremost-stage impeller 4 , to take in the fluid F from the outside, and to allow the fluid F to flow into this impeller 4 .
[0062] The discharge port 6 is formed with a discharge channel FC 2 that passes through the casing 1 in the radial direction of the axis O so as to communicate with the interior and exterior of the casing 1 . The discharge channel FC 2 is adapted to communicate with an interior of the rearmost-stage impeller 4 , and to be able to discharge the fluid F from this impeller 4 to the outside.
[0063] Next, with regard to a manufacturing method (including a plating method) of the centrifugal compressor 100 , first, an outline of manufacturing processes will be given, and then details of each process will be described.
[0064] As illustrated in FIG. 2 , the manufacturing method of the centrifugal compressor 100 includes a casing forming process S 0 of forming the casing 1 , a preparing process S 1 of preparing plating work for the inner surface 1 a of the casing 1 after the casing forming process S 0 , and a surface activating process S 2 of supplying a pretreatment liquid W 1 into the casing 1 after the preparing process S 1 and activating the inner surface 1 a of the casing 1 .
[0065] Further, the manufacturing method of the centrifugal compressor 100 includes a cleaning process S 3 of cleaning the interior of the casing 1 after the surface activating process S 2 , a preheating process S 4 of supplying a preheating liquid W 2 into the casing 1 and preheating the casing 1 after the cleaning process S 3 , a plating process S 5 of supplying a plating liquid W 3 into the casing 1 and plating the inner surface 1 a of the casing 1 after the preheating process S 4 , and a casing finishing process S 6 of finishing the casing 1 after the plating process S 5 .
[0066] Then, the manufacturing method of the centrifugal compressor 100 includes an assembling process S 7 of incorporating the internal casing 2 , the rotary shaft 3 , and the impeller 4 into the casing 1 after the casing finishing process S 6 . The final centrifugal compressor 100 is manufactured via these processes.
[0067] First, the casing forming process S 0 is carried out. In detail, a cylindrical casing 1 is formed using machining such as casting.
[0068] Next, the preparing process S 1 is carried out. In detail, masking is performed on an unnecessary plating portion of the casing 1 . Afterwards, the casing 1 is placed such that the direction of the axis O is identical to a vertical direction and the intake port 5 is disposed downward. Since the downstream opening part 11 is placed upward at this point in time, among the intake port 5 , the discharge port 6 , the upstream opening part 10 , and the downstream opening part 11 that are all the opening parts in the casing 1 , the largest opening part is directed upward.
[0069] In the preparing process S 1 , the upstream opening part 10 is additionally covered to prevent a liquid from leaking from the upstream opening part 10 . In addition, a pump 15 and a tank 16 (see FIG. 3 ) are installed to connect pipings 16 a to the intake port 5 and the discharge port 6 .
[0070] Although details of the tank 16 are not illustrated, three kinds of liquids, i.e. the pretreatment liquid W 1 , the preheating liquid W 2 , and the plating liquid W 3 , are adapted to each be stored separately. Then, the liquid used in each process is separately supplied into the casing 1 via the piping 16 a. Further, the liquids discharged from the interior of the casing 1 are adapted to be recovered, via the piping 16 a. Further, a pH value, a concentration, and a temperature of each liquid are properly adjusted so as to have predetermined values at all times.
[0071] In the preparing process S 1 , an alkaline solution is sprayed onto the inner surface 1 a of the casing 1 , and treatment such as degreasing is performed on the inner surface 1 a . For example, as the alkaline solution, a mixture such as sodium hydroxide, a silicate, and a surfactant is used. After the treatment of the inner surface 1 a is performed, flushing is performed by spraying water on the inner surface 1 a.
[0072] Further, a cover member 17 , which surrounds an opening edge 11 a of the downstream opening part 11 from the outer circumference side so as to cause the downstream opening part 11 opened upward to further extend in an upward direction and has a cylindrical shape in which a space in which the liquid is collected is formed in an upper portion of the downstream opening part 11 , is mounted on an upper portion of the casing 1 . The cover member 17 may be fixed to the upper portion of the casing 1 , or it may simply be placed on the upper portion of the casing 1 , for instance, via a packing.
[0073] Next, the surface activating process S 2 is performed. In detail, the pretreatment liquid W 1 is supplied from the tank 16 to the intake port 5 by the pump 15 , and the interior of the casing 1 is filled with the pretreatment liquid W 1 . In this case, it is preferable to decide a supplied amount of the pretreatment liquid W 1 such that a liquid level SF of the stored pretreatment liquid W 1 is located inside the cover member 17 or overflows over the cover member 17 , and the liquid level SF preferably reaches the upper portion of the downstream opening part 11 . Afterwards, the pretreatment liquid W 1 is discharged from the discharge port 6 of the casing 1 , is recovered to the tank 16 , and removes an oxide film of the inner surface 1 a of the casing 1 to activate the inner surface 1 a.
[0074] As the pretreatment liquid W 1 , for example, an acid solution such as hydrochloric acid adjusted to room temperature is used.
[0075] The cleaning process S 3 is performed after the surface activating process S 2 . In detail, flushing is performed on the inner surface 1 a of the casing 1 which is activated by the pretreatment liquid W 1 using a spray.
[0076] Next, the preheating process S 4 is performed. In detail, with respect to the casing 1 flushed in the cleaning process S 3 , the preheating liquid W 2 is supplied from the tank 16 to the intake port 5 by the pump 15 , and the interior of the casing 1 is filled with the preheating liquid W 2 . Then, it is preferable to decide a supplied amount of the preheating liquid W 2 such that a liquid level SF of the preheating liquid W 2 stored in the casing 1 is located inside the cover member 17 or overflows over the cover member 17 , and the liquid level SF preferably reaches the upper portion of the downstream opening part 11 . Afterwards, the preheating liquid W 2 is discharged from the discharge port 6 of the casing 1 , is recovered in the tank 16 , and raises a temperature of the casing 1 before the plating work.
[0077] As the preheating liquid W 2 , for example, an aqueous solution including a reductant adjusted to a temperature of about 90° C. is used. As the reductant, for example, sodium hypophosphite is used, but other typical reductants may be used.
[0078] Here, the flushing may be performed after the preheating process S 4 has been performed.
[0079] Next, the plating process S 5 is performed. In detail, with respect to the casing 1 preheated in the preheating process S 4 , the plating liquid W 3 is supplied from the tank 16 to the intake port 5 by the pump 15 , and the interior of the casing 1 is filled with the plating liquid W 3 . A supplied amount of the plating liquid W 3 filling the casing 1 is decided such that a liquid level SF of the plating liquid W 3 is located inside the cover member 17 or overflows over the cover member 17 . Namely, the liquid level SF is adapted to reach the upper portion of the downstream opening part 11 , and the casing 1 remains filled with the plating liquid W 3 up to the uppermost portion thereof. In this state, the plating liquid W 3 is discharged from the discharge port 6 , and is recovered to the tank 16 . In a state in which the interior of the casing 1 is filled with the plating liquid W 3 , the plating liquid W 3 is circulated to plate the inner surface of the casing 1 .
[0080] As the plating liquid W 3 , for example, an electroless nickel plating liquid W 3 adjusted to a temperature of about 90° C. is used.
[0081] Next, the casing finishing process S 6 is performed. In detail, the plated inner surface 1 a of the casing 1 is flushed using a spray first, and then is dried, and the casing 1 is finished. Further, a baking treatment (hydrogen embrittlement removal) may be carried out.
[0082] Finally, the assembling process S 7 is performed. In detail, the internal casing 2 , the rotary shaft 3 , and the impeller 4 are installed in the casing 1 , and the centrifugal compressor 100 is manufactured.
[0083] In this manufacturing method of the centrifugal compressor 100 , the pretreatment liquid W 1 is supplied from the intake port 5 formed in the casing 1 , and is discharged from the discharge port 6 . Thereby, the inner surface 1 a of the casing 1 is activated by the pretreatment liquid W 1 . Likewise, the preheating liquid W 2 and the plating liquid W 3 are supplied and discharged from the intake port 5 and the discharge port 6 . Thereby, the plating work for the inner surface 1 a of the casing 1 can be performed.
[0084] In detail, in the surface activating process S 2 and the plating process S 5 , the supply and discharge of the pretreatment liquid W 1 and the plating liquid W 3 can be performed using the multiple opening parts with no change. Accordingly, separate nozzles for supplying and discharging these liquids are not provided, and a plating tank for immersing the entire casing 1 is not required either. As such, the plating work for the inner surface 1 a of the casing 1 is possible.
[0085] Here, especially in the casing 1 having a large size and a complicated shape, it takes time to raise the temperature based on the circulation of the plating liquid W 3 . Further, the plating liquid W 3 is partly immersed, and thereby unevenness in the temperature may occur at the inner surface 1 a of the casing 1 . For this reason, a sufficient quality of plating may not be obtained. In view of this, the preheating process S 4 is performed before the plating process S 5 , and thereby a preheating tank for immersing the entire casing 1 is not required. As such, the temperature of the casing 1 can be uniformly raised. For this reason, a quality of plating can be further improved.
[0086] Further, in the preheating process S 4 , the preheating liquid W 2 containing the reductant is used. Thereby, in the inner surface 1 a of the casing 1 which is a portion to be plated, it is possible to prevent the oxide film from forming during the preheating. That is, it is possible to achieve the antioxidation of the inner surface 1 a of the casing 1 , and to further improve the quality of plating in the plating process S 5 .
[0087] Furthermore, the casing 1 is placed such that the downstream opening part 11 that is the largest opening part is directed upward, and the plating work is performed. For this reason, hydrogen gas that is generated during the plating work and is attached to the inner surface 1 a of the casing 1 can be easily discharged outside the casing 1 . Therefore, the quality of plating can be further improved in the plating process S 5 .
[0088] Thus, in the present embodiment, in the state in which the cover member 17 is provided upward and the space in which the liquid is collected is formed in an upper portion of the casing 1 , each of the pretreatment liquid W 1 , the preheating liquid W 2 , and the plating liquid W 3 is supplied into the casing 1 . For this reason, the liquid level SF of the liquid supplied into the casing 1 is placed at a higher position than the downstream opening part 11 , and the plating work can be performed up to the opening edge 11 a of the downstream opening part 11 . Accordingly, since the plating work can be reliably performed on the entire inner surface 1 a of the casing 1 , this leads to further improvement in the quality of plating. Each liquid overflowing from the upper portion of the cover member 17 is recovered to the tank 16 and is reused.
[0089] Further, since the plating liquid W 3 is supplied from the intake port 5 and the discharge port 6 of the casing 1 , inner surfaces 1 a of the intake and discharge channels FC 1 and FC 2 can also be plated at the same time.
[0090] According to the manufacturing method of the centrifugal compressor 100 of the present embodiment, the pretreatment liquid W 1 and the plating liquid W 3 are supplied and discharged using the intake and discharge ports 5 and 6 formed in the casing 1 . Thereby, costs are reduced, and the plating work for the inner surface 1 a of the casing 1 can be performed in a simple way.
[0091] Here, in the present embodiment, the pretreatment liquid W 1 , the preheating liquid W 2 , and the plating liquid W 3 are adapted to be supplied from the intake port 5 of the casing 1 and be discharged from the discharge port 6 . However, without being limited to such an example, conversely, each liquid may be supplied from the discharge port 6 and be discharged from the intake port 5 , or be supplied and discharged using the upstream opening part 10 and the downstream opening part 11 . Further, in addition to the intake port 5 , the discharge port 6 , the upstream opening part 10 , and the downstream opening part 11 , each liquid may be supplied and discharged through other opening parts formed in the casing 1 .
[0092] Incidentally, of the intake and discharge ports 5 and 6 , the opening part from which high corrosion resistance is particularly required may be subjected to overlaying using a stainless steel material. Such an opening part requires no plating work. For this reason, as the pretreatment liquid W 1 , the preheating liquid W 2 , and the plating liquid W 3 are supplied and discharged from the opening part from which the plating is required among the multiple opening parts, the plating work is performed on the inner surface 1 a of the casing 1 , and these opening parts can be plated. Therefore, the casing 1 can be more efficiently plated. For example, in a side stream type of compressor, since two intake ports 5 and one discharge port 6 are provided, the opening parts supplying and discharging the liquid can be appropriately selected from these intake ports 5 and the discharge port 6 .
[0093] When there is a low possibility of unevenness in temperature occurring at the inner surface 1 a of the casing 1 in view of a shape and size of the casing 1 , the preheating process S 4 may not necessarily be performed. Further, no reductant is contained in the preheating liquid W 2 used in preheating process S 4 .
[0094] The supply of the plating liquid W 3 may also be initiated before the preheating liquid W 2 is completely discharged.
[0095] The casing 1 is placed in the state in which the downstream opening part 11 is directed upward, and each liquid is supplied and discharged. However, the casing 1 may be placed, for instance, such that the direction of the axis O becomes a horizontal direction, i.e. such that a direction in which the upstream opening part 10 and the downstream opening part 11 are open becomes a horizontal direction, and each liquid may be supplied and discharged.
[0096] In the preparing process S 1 , the cleaning process S 3 , and the casing finishing process S 6 , the interior of the casing 1 is flushed by the spray. Instead of this, similar to the surface activating process S 2 , the preheating process S 4 , and the plating process S 5 , water may be supplied and discharged using the intake port 5 , the discharge port 6 , the upstream opening part 10 , and the downstream opening part 11 , and the inner surface 1 a of the casing 1 may be flushed. The same is true when the flushing is performed after the preheating process S 4 .
[0097] The cover member 17 may not necessarily be provided, and the surface activating process S 2 , the preheating process S 4 , and the plating process S 5 may be performed by supplying each liquid such that each liquid overflows from the downstream opening part 11 opened upward.
Second Embodiment
[0098] Next, a method of manufacturing a centrifugal compressor 100 according to a second embodiment of the present invention will be described.
[0099] The same components as in the first embodiment will be given the same numerals or symbols, and detailed description thereof will be omitted.
[0100] In the present embodiment, a plating process S 25 is different from that of the first embodiment.
[0101] As illustrated in FIG. 4 , in the plating process S 25 , plating work is performed on an inner surface 1 a of a casing 1 in a state in which a stirring propeller 21 acting as a stirring device is inserted from a downstream opening part 11 .
[0102] The stirring propeller 21 has a body part 22 shaped of a rod extending in a direction of an axis O, blade parts 23 that are provided in one body so as to protrude to a radial outer side of the body part 22 , i.e. so as to be directed to the inner surface 1 a of the casing 1 , and a driving part 24 such as an electric motor which clamps the body part 22 to provide a rotational force about the axis O.
[0103] In the plating process S 25 , a plating liquid W 3 is circulated while the stirring propeller 21 is rotated and an interior of the casing 1 filled with the plating liquid W 3 is stirred.
[0104] According to the method of manufacturing the centrifugal compressor 100 of the present embodiment, even in the case of the casing 1 that is large and has a complicated shape, the use of the stirring propeller 21 allows a flow velocity of the plating liquid W 3 in the casing 1 to be set to a numerical value most suitable for plating work.
[0105] Further, hydrogen gas that is generated during the plating work and is attached to the inner surface 1 a of the casing 1 is removed. Thereby, it is possible to prevent the plating work from being obstructed at portions at which the hydrogen gas is attached. For this reason, a quality of plating can be further improved in the plating process S 25 .
[0106] Here, another device may be used as the stirring device. Namely, the plating liquid W 3 in the casing 1 can also be convected and stirred, for instance, by controlling a flow rate of the supplied or discharged plating liquid W 3 . To be specific, as a supplied amount of the plating liquid W 3 from an intake port 5 is increased, and a discharged amount of the plating liquid W 3 from the discharge port 6 is reduced, convection of the plating liquid W 3 can be generated, and the foregoing effects can be obtained like the stirring propeller 21 .
[0107] Further, the stirring propeller 21 can be applied to the plating process S 25 as well as a surface activating process S 2 , a preheating process S 4 , a cleaning process S 3 , and so on. Thereby, the quality of plating can be further improved.
Third Embodiment
[0108] Next, a method of manufacturing a centrifugal compressor 100 according to a third embodiment of the present invention will be described.
[0109] The same components as in the first and second embodiments will be given the same numerals or symbols, and detailed description thereof will be omitted.
[0110] In the present embodiment, a plating process S 35 is different from those of the first and second embodiments.
[0111] As illustrated in FIG. 5 , in the plating process S 35 , a core 31 of a columnar shape is provided by insertion from a downstream opening part 11 so as to have the same axis as a casing 1 , i.e. in a state in which a central axis of the core 31 is identical to an axis O and the core 31 is spaced apart from an inner surface 1 a of the casing 1 , and plating work for the inner surface 1 a of the casing 1 is performed.
[0112] According to the method of manufacturing the centrifugal compressor 100 of the present embodiment, the core 31 is inserted, so that an internal volume of the casing 1 can be reduced. For this reason, a supplied amount of a plating liquid W 3 can be reduced, which leads reduction of costs. Further, the plating liquid W 3 causes flowing between the core 31 and the inner surface 1 a of the casing 1 . For this reason, a flow channel when the plating liquid W 3 circulates and flows in the casing 1 is reduced, and a flow can be made smooth. Therefore, a quality of plating can be improved.
[0113] Further, a space defined between the inner surface 1 a of the casing 1 and the core 31 has a constant gap throughout the circumference in a radial direction of the axis O in order to provide the core 31 on the same axis as the casing 1 . Accordingly, a flow velocity of the plating liquid W 3 flowing through an interior of the casing 1 can be made uniform, and thus the quality of plating can be further improved.
[0114] The core 31 may not necessarily be provided on the concentric axis. If the core 31 is at least provided so as to reduce the internal volume of the casing 1 , the supplied amount of the plating liquid W 3 is reduced to enable cost reduction.
[0115] Further, the core 31 is rotated around the axis O or is caused to move up and down, and thereby the core 31 can be used as a stirring device. Hydrogen gas attached to the inner surface 1 a of the casing 1 during the plating work is removed, and the quality of plating can be further improved.
[0116] Furthermore, the core 31 can be applied to the plating process S 35 as well as a surface activating process S 2 , a preheating process S 4 , or a cleaning process S 3 . Thereby, the quality of plating can be further improved.
Fourth Embodiment
[0117] Next, a method of manufacturing a centrifugal compressor 100 according to a fourth embodiment of the present invention will be described.
[0118] The same components as in the first to third embodiments will be given the same numerals or symbols, and detailed description thereof will be omitted.
[0119] In the present embodiment, a plating process S 45 is different from those of the first to third embodiments.
[0120] As illustrated in FIG. 6 , like the third embodiment, in the plating process S 45 , a core 41 with a cylindrical shape is provided so as to have the same axis as a casing 1 , i.e. in a state in which a central axis of the core 41 is identical to an axis O. Further, the core 41 is provided by insertion from a downstream opening part 11 in a state in which the core 41 is spaced apart from an inner surface 1 a of the casing 1 , and plating work for the inner surface 1 a of the casing 1 is performed.
[0121] Here, the core 41 is a hollow member, and an outer circumferential surface thereof is formed with multiple through-holes 41 a so as to communicate with the interior and exterior of the core 41 . The core 41 is connected to the tank 16 via a piping 41 b and a pump 42 . A plating liquid W 3 is supplied into the core 41 during the plating work.
[0122] According to the method of manufacturing the centrifugal compressor 100 of the present embodiment, the core 41 is inserted, and the plating liquid W 3 is supplied into the core 41 . Thereby, the plating liquid W 3 flows between the core 41 and the inner surface 1 a of the casing 1 . For this reason, a flow channel of the plating liquid W 3 is reduced, and a flow can be made smooth. Further, since the plating liquid W 3 can be ejected from the through-holes 41 a toward the inner surface 1 a of the casing 1 , it is possible to obtain a stirring effect in the casing 1 . Accordingly, it is possible to measure a uniform flow velocity of the plating liquid W 3 in the casing 1 , and to remove hydrogen gas attached to the inner surface 1 a of the casing 1 during the plating work. Therefore, a quality of plating can be improved in the plating process S 45 .
[0123] The core 41 may not necessarily be provided on the concentric axis. The core 41 is rotated around the axis O or is caused to move up and down, and thereby the stirring effect can be further improved. The core 41 can be applied to the plating process S 45 as well as a surface activating process S 2 , a preheating process S 4 , or a cleaning process S 3 .
Fifth Embodiment
[0124] Next, a method of manufacturing a centrifugal compressor 100 according to a fifth embodiment of the present invention will be described.
[0125] The same components as in the first to fourth embodiments will be given the same numerals or symbols, and detailed description thereof will be omitted.
[0126] In the present embodiment, a plating process S 55 is different from those of the first to fourth embodiments.
[0127] As illustrated in FIG. 7 , in the plating process S 55 , plating work for an inner surface 1 a of a casing 1 is performed in a state in which plating supply hoses 51 acting as a stirring device are inserted from a downstream opening part 11 .
[0128] Here, the plating supply hoses 51 are connected to a tank 16 via piping 51 a and a pump 52 . A plating liquid W 3 is adapted to be supplied from an interior of the tank 16 into the casing 1 .
[0129] According to the method of manufacturing the centrifugal compressor 100 of the present embodiment, the plating liquid W 3 is supplied by the plating supply hoses 51 alongside the supply from an intake port 5 . Thereby, it is possible to remove hydrogen gas attached to the inner surface 1 a of the casing 1 during the plating work. Therefore, it is possible to prevent the plating work from being obstructed at portions at which the hydrogen gas is attached. For this reason, a quality of plating can be further improved in the plating process S 55 .
[0130] Particularly, when the casing 1 has a more complicated shape, a water stop region is formed at a corner portion such as a connection portion between the inner surface 1 a of the casing 1 and an intake channel FC 1 and between the inner surface 1 a of the casing 1 and a discharge channel FC 2 . The plating liquid W 3 is supplied from the plating supply hoses 51 at this position, and an effect of removing the hydrogen gas can be further improved.
[0131] The plating supply hoses 51 can carry out the plating process S 55 as well as a surface activating process S 2 , a preheating process S 4 , or a cleaning process S 3 using the same technique as in the present embodiment in which each liquid is supplied by the supply hoses. Thereby, the quality of plating can be further improved.
[0132] In the present embodiment, the plating supply hoses 51 are used as the stirring device. Instead of this, plating suction hoses suctioning the plating liquid W 3 from the interior of the casing 1 can also be used.
Sixth Embodiment
[0133] Next, a method of manufacturing a centrifugal compressor 100 according to a sixth embodiment of the present invention will be described.
[0134] The same components as in the first to fifth embodiments will be given the same numerals or symbols, and detailed description thereof will be omitted.
[0135] In the present embodiment, a plating process S 65 is different from those of the first to fifth embodiments.
[0136] As illustrated in FIG. 8 , in the plating process S 65 , a mounting table 61 is provided as a vibration imparting device, and plating work is performed in a state in which a casing 1 is placed on the mounting table 61 .
[0137] Here, the mounting table 61 has, for instance, an electric motor (not shown), and is a device that generates vibration in a horizontal direction, a vertical direction, and forward, backward, leftward, and rightward directions.
[0138] According to a method of manufacturing a centrifugal rotary machine of the present embodiment, vibration is imparted to the casing 1 by the mounting table 61 in a state in which a plating liquid W 3 is stored in the casing 1 . For this reason, it is possible to prevent stagnation of hydrogen gas that is generated during plating work and is attached to an inner surface 1 a of the casing 1 . Accordingly, a quality of plating can be further improved in the plating process S 65 .
[0139] Here, without using the mounting table 61 as the vibration imparting device, a technique of, for instance, directly striking the casing 1 may also be used.
[0140] Further, ultrasonic waves may also be imparted to the casing 1 using an ultrasonic generator (ultrasonic generating part) generating the ultrasonic waves as the vibration imparting device.
[0141] Furthermore, the vibration imparting device can be applied to the plating process S 65 as well as a surface activating process S 2 , a preheating process S 4 , or a cleaning process S 3 . Thereby, the quality of plating can be further improved.
Seventh Embodiment
[0142] Next, a method of manufacturing a centrifugal compressor 100 according to a seventh embodiment of the present invention will be described.
[0143] The same components as in the first to sixth embodiments will be given the same numerals or symbols, and detailed description thereof will be omitted.
[0144] In the present embodiment, a plating process S 75 is different from those of the first to sixth embodiments.
[0145] As illustrated in FIG. 9 , in the plating process S 75 , plating work is performed by a brush 71 inserted from a downstream opening part 11 while an inner surface 1 a of a casing 1 is rubbed.
[0146] The brush 71 is shaped of a rod which extends in a direction of an axis O with multiple hairs being provided on an outer circumferential surface thereof, and is displaced up and down by a driving part 74 such as an electric motor. The driving part 74 may rotate the brush 71 around the axis O.
[0147] According to the method of manufacturing the centrifugal rotary machine of the present embodiment, in a state in which a plating liquid W 3 is stored in the casing 1 , the inner surface 1 a of the casing 1 is rubbed by the brush 71 . For this reason, it is possible to prevent stagnation of hydrogen gas that is generated during plating work and is attached to the inner surface 1 a of the casing 1 . Therefore, a quality of plating can be further improved in the plating process S 75 .
[0148] The brush 71 can be applied to the plating process S 75 as well as a surface activating process S 2 , a preheating process S 4 , or a cleaning process S 3 . Thereby, the quality of plating can be further improved.
Eighth Embodiment
[0149] Next, a method of manufacturing a centrifugal compressor 100 A according to an eighth embodiment of the present invention will be described.
[0150] The same components as in the first to seventh embodiments will be given the same numerals or symbols, and detailed description thereof will be omitted.
[0151] In the present embodiment, a casing 1 A that is a target to be plated is different from those of the first to seventh embodiments. Further, a plating process S 85 is different from those of these embodiments.
[0152] As illustrated in FIGS. 10A and 10B , in the plating process S 85 , the casing 1 A undergoing plating work is given as a horizontal division type that is divided into two parts so as to include an axis O.
[0153] In the plating process S 85 , the plating work is performed in a state in which the casing 1 A is placed in a halved state such that the axis O becomes a horizontal direction, i.e., such that a direction in which an upstream opening part 10 A and a downstream opening part 11 A are open becomes a horizontal direction. At this point in time, a division-side opening part 82 of the casing 1 A is placed upward. For this reason, among an intake port 5 A, a discharge port 6 A, the upstream opening part 10 A, the downstream opening part 11 A, and the division-side opening part 82 that are all opening parts in the casing 1 , the largest opening part remains directed upward.
[0154] Further, in the plating process S 85 , plating work is performed in a state in which an interior of the casing 1 A is partitioned into two spaces by a partition plate 81 shaped of a plate. To be specific, the partition plate 81 is provided between the intake port 5 A and the discharge port 6 A so as to be perpendicular to the axis O, and the partition plate 81 is sandwiched to partition the interior of the casing 1 A into a first space C 1 of one side in a direction of the axis O (right side in the space of FIG. 10A ) and a second space C 2 of the other side in the direction of the axis O.
[0155] The partition plate 81 is installed to be plugged into a groove 1 Aa formed in the inner surface 1 a of the casing 1 A in a ring shape in a circumferential direction of the axis O. In this case, a gap may also be present between the inner surface 1 a of the casing 1 A and the partition plate 81 .
[0156] In the plating process S 85 , the upstream opening part 10 A and the intake port 5 A communicate with the first space C 1 , and the downstream opening part 11 A and the discharge port 6 A communicate with the second space C 2 . That is, at least two opening parts communicate with each space.
[0157] According to the method of manufacturing the centrifugal compressor 100 A of the present embodiment, the space in the casing 1 A in which a plating liquid W 3 circulates can be divided into the first space C 1 and the second space C 2 . For this reason, the plating liquid W 3 can flow through each space, and fluidity of the plating liquid W 3 in the casing 1 A can be improved compared to when the partition plate 81 is not provided. Therefore, a quality of plating can be improved.
[0158] In the present embodiment, the partition plate 81 can be applied to the plating process S 85 as well as a surface activating process S 2 , a preheating process S 4 , or a cleaning process S 3 . Thereby, the quality of plating can be further improved.
[0159] Although preferred embodiments of the present invention have been described in detail, some design changes are also possible without departing from the technical idea of the present invention.
[0160] In the aforementioned embodiments, the cylindrical type of casing 1 has been described with regard to the first to seventh embodiments. However, the method of manufacturing the centrifugal compressor 100 in these embodiments may be applied to the horizontal division type of casing 1 A described in the eighth embodiment. In this case, as illustrated in FIGS. 10A and 10B , the casing 1 A is preferably placed in a halved state such that the division-side opening part 82 is directed upward.
[0161] Further, in the eighth embodiment, the horizontal division type of casing 1 A has been described. However, the method of manufacturing the centrifugal compressor 100 A in the eighth embodiment may be applied to the cylindrical type of casing 1 described in the first to seventh embodiments. In this case, the casing 1 is preferably placed such that the downstream opening part 11 or the upstream opening part 10 is directed upward.
[0162] Furthermore, the methods for manufacturing the centrifugal compressor 100 ( 100 A) described in the first to eighth embodiments may be appropriately combined. For example, the stirring propeller 21 of the second embodiment may be combined with the mounting table 61 of the sixth embodiment.
[0163] Further, in the aforementioned embodiments, the centrifugal compressor 100 ( 100 A) has been described, but the aforementioned manufacturing method may be applied to other rotary machines such as an axial compressor, a turbine, and so on.
INDUSTRIAL APPLICABILITY
[0164] According to the method of manufacturing the rotary machine, the method of plating the rotary machine, and the rotary machine, all of which are described above, the pretreatment liquid and the plating liquid are supplied and discharged using the opening parts formed in the casing, and thereby costs can be reduced, and the plating work for the casing can be done by a simple technique.
REFERENCE SIGNS LIST
[0165] 1 : casing
[0166] 1 a : inner surface
[0167] 2 : internal casing
[0168] 3 : rotary shaft (rotating body)
[0169] 4 : impeller (rotating body)
[0170] 5 : intake port (opening part)
[0171] 6 : discharge port (opening part)
[0172] 10 : upstream opening part
[0173] 11 : downstream opening part
[0174] 11 a : opening edge
[0175] 15 : pump
[0176] 16 : tank
[0177] 16 a : piping
[0178] 17 : cover member
[0179] 100 : centrifugal compressor (rotary machine)
[0180] O: axis
[0181] F: fluid
[0182] FC 1 : intake channel
[0183] FC 2 : discharge channel
[0184] S 0 : casing forming process
[0185] S 1 : preparing process
[0186] S 2 : surface activating process
[0187] S 3 : cleaning process
[0188] S 4 : preheating process
[0189] S 5 : plating process
[0190] S 6 : casing finishing process
[0191] S 7 : assembling process
[0192] SF: liquid level
[0193] W 1 : pretreatment liquid
[0194] W 2 : preheating liquid
[0195] W 3 : plating liquid
[0196] S 25 : plating process
[0197] 21 : stirring propeller (stirring device)
[0198] 22 : body part
[0199] 23 : blade part
[0200] 24 : driving part
[0201] S 35 : plating process
[0202] 31 : core
[0203] S 45 : plating process
[0204] 41 : core
[0205] 41 a : through-hole
[0206] 41 b : piping
[0207] 42 : pump
[0208] S 55 : plating process
[0209] 51 : plating supply hose (stirring device)
[0210] 51 a : piping
[0211] 52 : pump
[0212] S 65 : plating process
[0213] 61 : mounting table (vibration imparting device)
[0214] S 75 : plating process
[0215] 71 : brush
[0216] 74 : driving part
[0217] 1 A: casing
[0218] 1 Aa: groove
[0219] 5 A: intake port
[0220] 6 A: discharge port
[0221] 10 A: upstream opening part
[0222] 11 A: downstream opening part
[0223] 81 : partition plate
[0224] 82 : division-side opening part
[0225] S 85 : plating process
[0226] C 1 : first space
[0227] C 2 : second space
[0228] 100 A: centrifugal compressor (rotary machine) | Provided is a method of manufacturing a rotary machine, which includes: a casing forming process of forming a casing of the rotary machine that has multiple opening parts and suctions and discharges a fluid; a surface activating process of supplying a pretreatment liquid into the casing, then discharging the pretreatment liquid from the casing through the opening parts, and activating an inner surface of the casing after the casing forming process; a plating process of performing supply and discharge of a plating liquid into and from the easing through the opening parts to circulate the plating liquid and plating the inner surface of the casing after the surface activating process; and an assembling process of providing a rotating body that is rotatable relative to the casing so as to he covered from an outer circumference side by the casing plated in the plating process. | 8 |
BACKGROUND
1. Field of the Invention
This invention relates generally to printing-press equipment, and more particularly to a "suction foot" or "sheet sucker" used in small presses to separate the top piece of stock (paper, cardboard, etc.) from a pile and to forward that top piece into the press proper.
2. Prior Art
There are basically three known forms of suction foot for a printing press. The first is simply a cut-off hollow rod, attached at the top to a suction system tnat is part of the press (or is added later). Attached to the bottom tip of the rod there is usually a soft rubber or plastic hood that droops slightly onto the stock to enhance the suction effect between the tip of the rod and the stock.
Such a foot is moved by the press mechanism in such a way that it slightly lifts the top sheet of stock from the supply pile, or moves the top sheet forward after it has been lifted, or both. In the printing craft the lifting process is generally called "separation"; the forward motion, which moves the sheet into a position where it can be pulled along by rollers in the press, is generally called "forwarding".
Simple cut-off rods are problematical in that they must be positioned very carefully for each project (and for each sheet), to apply suction effectively without punching holes or indentations into the stock. This is particularly difficult since the height of the pile of stock changes continuously during operation of the press, and the servocontrolled stock elevator cannot perform perfectly.
Cut-off rods are also troublesome because they tend to compress the top of the pile slightly, pushing air out of the pile. Effective separation requires ready access of air under each of the top few sheets--to push the top sheet upwardly, while the suction system removes the downward pressure normally presented by air above the top sheet.
Nevertheless, such suction feet are used widely in small presses for their extreme simplicity and low cost--but most particularly because they do not take up much room. The simple rod-type foot does not extend horizontally toward the pullout rollers, various crossbar mounts, or side guides and side walls in the rather cramped quarters within a small press, and its suction hose extends vertically, up out of the way of these various other components.
Hence design efforts have been concentrated in providing adjustments for the rod-type suction foot, relative to the top of the supply pile, that are as accurate as such things can economically be. Such adjustments sometimes require considerable "fussing" by the press operator at the beginning of each project, and continual vigilance to be certain that the stock is not being damaged by drift of the adjustment, or by excessive dead zone in the elevator servosystem.
A second generation of suction foot is known as the "compensating foot" or, more affectionately, "compensating sucker". The compensating type has a vertical cylinder, with a hollow internal piston and rod that are within the cylinder and are spring-loaded downwardly relative to the cylinder. At the lower tip of the piston rod there is of course a floppy hood as before. At the top of the cylinder is a hollow support rod (similar to the cut-off rod foot) that is attached to the suction system of the press. The hole in the support rod communicates directly witn the space above the piston, and hence communicates with the hole through the piston and rod.
In operation the compensating sucker is lowered by the press mechanism toward the pile of sheets, if it is being used for separation. If the sucker is being used for forwarding only, a sheet is raised toward the compensating sucker. In either case, before the solidly supported cylinder hits the top sheet, the downwardly spring-loaded piston-rod tip engages the sheet, closing the end of the air passage. The suction now becomes effective to hold the sheet of stock up against the tip, but with much less fussiness of adjustment since the tip may engage the sheet anywhere within the piston stroke.
For the compensating sucker to work well in a separating mode, however, it is also necessary for the suction system to draw the piston upward within the cylinder. In other words, once the sheet of stock has closed off the bottom of the piston-rod tip, the dead air space within the piston and piston rod act almost as if they were part of the piston. The situation is theoretically as if the piston were solid, and the suction applied above the piston should retract the tip. In theory the sheet is thus raised from the top of the pile.
In practice these devices are unreliable, because the suction force for retraction is opposed both by the spring and by gravity. The pressure differential available from a typical suction system often varies in operation, and especially with age; and the weight of a sheet of stock varies substantially. Small pieces of dirt and the like can increase stiction in the system, making matters worse.
The overall result is unreliable retraction. In addition the compensating sucker if used for both separation and forwarding often drags on horizontal return, damaging or marking the next sheet. Furthermore, the downwardly spring-loaded foot sometimes presses too hard on the pile, before the suction takes effect to retract the foot. In such cases air is squeezed out of the top of the pile, impairing separation as with a cut-off rod.
A third type of suction foot, sometimes called a "sheet seeker", has been previously found only on large presses, and has been used almost exclusively for forwarding. In addition, the sheet-seeker type has been used only to support a sheet from generally the center of the sheet (relative to the direction of feed), rather than from the leading edge. Finally, sheet seekers have been used only in "stream feeding" systems--systems in which successive sheets are overlapped for travel into the rollers of the press, rather than being strictly consecutive as in a pure "sheet feeding" system.
Except for these severe limitations in application, the sheet-seeker foot operates very well. It too has a cylinder, spring-loaded hollow piston and piston rod, and suction-system attachment. The spring-loading, however, is upward rather than downward, and the suction-system connection point is not through the top support rod but rather by means of an external port partway down the side wall of the cylinder.
Thus the force relationships are reversed: it is the suction system (aided by gravity) that extends the suction tip downward toward the sheet, by drawing downwardly on the underside of the piston; and it is the spring that retracts the tip after the sheet is engaged. In this system there is a very fine pilot-pressure hole drilled radially through the piston-rod wallp--so that, when a sheet closes the bottom of the hollow piston rod, air is removed from the central hollow, equalizing the forces on the top and bottom of the piston. In some cases the same effect may be obtained by relying on leakage around the piston. The suction effect on the piston is thereby neutralized, and the spring drives the piston upward to retract the tip with the suspended sheet.
This operation has been found to be excellent, and sheet-seeking feet consequently are becoming generally standard on large presses--but, as previously mentioned only for center-of-sheet support and stream feed. They have not been used, even in large presses, for leading-edge support or sheet feed. Moreover, they have been only negligibly used for separation--as, for example, in certain Miehle units where there is a small amount of vertical motion and a large amount of horizontal motion.
The reason for nonuse of sheet seekers in small presses is fairly clear: prior sheet-seeker feet have been large, and their suction lines protruding from the sides of the cylinders have made them entirely impractical for small presses. By "small" I refer to presses capable of printing sheets no larger than, roughly fourteen by eighteen inches (roughly thirty-five by forty-five centimeters).
Many small presses such as the ATF Chief are particularly designed for (and particularly effective with) leading-edge sheet-feed forwarding. There would be inadequate room for the cylinder of a conventional sheet sucker, not to mention a forward-extending suction hose, anywhere near the leading edge of a sheet that is being individually (i. e., sheet-feed) forwarded. It will be understood that in stream feeding the leading edge of each sheet is carried into the press proper by its central or rearward portions. Consequently the suction foot need not move as far forward toward the pullout rollers and related hardware, and there is a lesser problem of clearances.
Even if the bulkiness of the cylinder could be overcome, prior sheet-seekers would still be extremely problematical in most or all small presses because of the suction line placement. For definiteness in the following discussion of clearances, the ATF Chief will be used as a point of reference. It will be understood, however, that the clearance problems as described are merely exemplary of analogous problems to be found in small presses generally.
If the suction line were extended forwardly from the cylinder wall, it would drag on the lower pullout roller or in some other way--as already suggested--aggravate the leading-edge clearance problem. If the suction lines for a pair of sheet-seeker feet were extended laterally "outward" (toward the side walls of the press) there would be a problem of clearing the side guides when small pieces of stock were being printed. There would be a problem of clearing the side walls, and related hardware there, when fairly large pieces of stock (approaching the lateral size capacity of the machine) were being printed.
On the other hand, if the lines for a pair of sheet seekers were extended laterally "inward" (toward each other), then there would be mutual interference, and interference with the upper pullout roller in many cases, for relatively small pieces of stock (such as envelopes and small announcements). If the lines were extended rearwardly--paralleling the direction of feed--there would be interference with the pile-height sensor, and/or with the transverse shaft that supports the side and rear guides.
The upshot of this discussion will be a realization that in a small press the suction hoses for even a slimmed-down version of the prior-art sheet seekers would have to be custom-rerouted for each job. For many jobs different hose lengths would have to be custom-installed. This kind of added chore would be an extreme aggravation to the pressman, and for competitive short-run commercial work would be totally uneconomical.
Furthermore, some small presses such as the AB Dick or Ryobi have suction feet that are a screw-in type. These are cut-off rods that thread into a hollow transverse bar, which supplies the suction at the top of the rods. Conventional sheet-seeker feet, with their lateral suction nipples, could not be mounted without custom modifications to the press.
It is not entirely clear to me why sheet-seeker feet have not been used in large presses for leading-edge support or sheet feed, or more extensively than they for separation, since many of the problems mentioned above would be alleviated by the more-ample clearances available in larger presses. I believe, however, that the reason is a combination of (1) the very awkward bulk of the conventional sheet-seeker configuration--particularly as to the hose-routing problem--and (2) the compound motion that is imparted to a suction foot when it is used for separation and forwarding in combination.
Restriction of the benefits of the sheet-seeker format to forwarding is very unfortunate. It is true that they are beneficial in forwarding because they are much less likely to drag on return, but sheet seekers are also particularly useful in separation. If they are not used, other types of suction foot must be used in tandem with the forwarding sheet seekers, to raise the sheets into engagement with the sheet seekers.
Such conventional cut-off rods or compensating suckers, in tandem with the sheet seekers, have all the previously enumerated disadvantages of damaging the stock or marring the finished work. These drawbacks are here compounded, however, by the big-business, high-pressure psychological environment that goes with operating the larger, more expensive equipment with its higher overhead.
Restriction of the benefits of the sheet-seeker format to center-of-sheet suspension is also undesirable, in comparison with leading-edge suspension, for the following reasons. In some multipass (e. g., multicolor) printing jobs, when the foot picks up the sheet in the printed area, incompletely dried ink tends to collect on the suction foot. This ink is then transferred to other sheets, marring the finished product. In other cases, spray powder that is used to hasten drying can collect on the suction foot, and be carried into the press--and thus into contact with the printing surfaces (e. g., the "blanket" in an offset lithographic press). Of course the powder interferes with the printing process, producing a ring pattern of the spray powder on the printed piece--but it can also interfere with the inking process, and on long runs the result can be a full-blown mess.
Finally, restriction of the sheet-seeker foot to stream feed is regrettable since accurate, positive feed can be obtained more economically in more modest presses that are designed for sheet feeding. Even the large presses that are sheet fed--such as one Heidelberg unit--do not use sheet-seeker feet.
Prior-art sheet seekers offer excellent performance relative to other suction-foot types; however, all the characteristics that make them incompatible with small presses, with separation, with leading-edge support, and with sheet feed, are serious disadvantages.
SUMMARY OF THE DISCLOSURE
My invention provides a sheet-seeking suction foot for combined sheet separation and forwarding, in a small printing press with a suction system.
The suction foot includes a cylinder with a side wall and a closed upper end, defining a cavity. The cylinder also has a constricted aperture at its lower end.
The suction foot of my invention also includes a piston that is closely fitted within the cylinder cavity, and that has a downwardly extending piston rod or shank. This shank is closely fitted within--and protrudes downwardly through--the aperture. The suction foot also includes a first air passage defined through the piston and shank.
Also part of the invention is a support rod extending upwardly from the closed upper end of the cylinder and adapted for mechanical attachment to the press. The support rod defines within it a second air passage, which is adapted for connection above the top of the cylinder to the suction system. This second air passage extends downwardly from the support rod into the closed upper end of the cylinder. For presses with screw-in feet as standard equipment, the support rod of my invention is simply cut to the correct length and threaded.
My invention also includes some means for communication between the cylinder cavity, below the piston, and the second air passage just mentioned. For purposes of speaking generally, these means for communication will be called the "air-passage means". The air-passage means are defined at least partially within the side wall of the cylinder.
In certain preferred embodiments of my invention, the air-passage means include (1) at least two individual fine axial passages within the side wall of the cylinder, and generally parallel to an axis of the cylinder; and (b) a corresponding number of individual fine radial passages within the side wall of the cylinder and at a point below the piston. These individual small radial passages communicate between respective axial passages and the cylindrical cavity.
In addition, in certain preferred embodiments the support rod is generally centrally disposed with respect to the upper end of the cylinder; and the air-passage means further include an additional corresponding number of individual fine radial passages within the closed upper end of the cylinder. These upper passages communicate between respective axial passages and the "second air passage" mentioned earlier.
Thus it will be understood that the fine air passages bored through the cylinder side walls and top wall serve to carry the suction effect that is applied to the hollow support rod down through the cylinder walls to a point below the piston. In this way the piston is pulled downwardly by the suction, but there is no port or nipple protruding and no hose horizontally extending from the side wall of the cylinder.
I prefer to provide at least four sets of axial and radial passages, since I have found that a smaller number is not adequate for a good suction effect at the tip of the device.
I also prefer to shape the cylinder wall externally to define two opposed very thin wall segments, each adapted for close juxtaposition of the center of the cylinder to other components within the press. The remaining segments of the cylinder wall are externally shaped to define two opposed relatively thick wall segments, to accommodate the radial and axial passages--or other air-passage means.
My invention also encompasses the combination of the suction foot, as above described, with a small printing press that has a suction system. In this combination the support rod is mechanically attached to the press so as to engage the top of a pile of sheets very near the front edge of each sheet. In this combination the second air passage is connected above the top of the cylinder to the suction system of the press.
The support rod is also mechanically actuated by the press mechanism so as to move the suction foot vertically as well as forward and back, and thereby to separate each sheet in turn and forward that sheet into the press for printing--in other words, to do both separation and forwarding. Finally, I prefer to use mechanisms that produce full sheet feeding as distinct from stream feeding.
All of the foregoing operational principles and advantages of the present invention will be more fully appreciated upon consideration of the following detailed description, with reference to the appended drawings, of which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exterior perspective view of a sheet-seeking suction foot that is a preferred embodiment of my invention, taken from slightly below the article.
FIG. 2 is an isometric view of the same embodiment, taken from slightly above the article, with the cylinder drawn partially in section to show the interior components and features.
FIG. 3 is a very generalized perspective view of the stock-feed area of a small printing press on which are installed two suction feet that are in accordance with the FIG. 1 embodiment of my invention.
FIG. 4 is an elevation of the FIG. 1 embodiment, also showing the cylinder partially in section, and in addition showing in section typical suction and mechanical-support connections to a printing press (such as that in FIG. 3).
FIGS. 5 and 6 are sectional plans of the upper and central portions of the cylinder, taken respectively along lines 5--5 and 6--6 of FIG. 4. (FIGS. 5 and 6 also both include section lines 4--4 along which FIG. 4 is taken.)
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
As shown in FIG. 1, my invention has a cylinder 10 that has preferably been made from a cylindrical piece of metal such as aluminum. Its outer surface is still partially cylindrical at two opposing sides as at 11, but to improve clearances has been cut off along two opposing sides to form planar surfaces 16.
The upper end of the cylinder 10 is unitary with a support rod 31, which extends upwardly from the top 19 of the cylinder 10. Visible in FIG. 1 are four small holes 13a, 13b 14a and 14b drilled into the portion of the wall that is still cylindrical--two near the top of the cylinder and two near the center (vertically). The outer ends of these holes are plugged. The purpose of these holes will shortly become clear.
The cylinder 10 is hollow, having a cylindrical cavity within it, and fitted within this cavity is a bushing 36 whose bottom surface may be generally flush with the bottom of the cylinder. The bushing 36, advantageously of metal, is held in place by a set screw that is threaded into a tapped hole 48 in the cylindrical portion of the cylinder wall.
The bushing 36 creates at the bottom of the cylindrical cavity a constricted aperture 38, through which protrudes downwardly a hollow piston rod or shank 21. The shank is advantageously metal, preferably aluminum. Defined in this shank 21 is a hole 24, which extends the entire length of the shank.
At the bottom end of the shank 21 is a narrow, shallow, circumferential flange 25; and slightly above it is a similar flange 26. Captured between these two flanges is an outwardly and downwardly extending soft rubber hood 41. The hood is stabilized in a conventional manner by a short vertical section 42 that closely surrounds the portion of the shank 21 between the two flanges 25 and 26.
As revealed by FIG. 2, and FIGS. 4 through 6, the piston rod or shank 21 extends upwardly within the cylindrical cavity 12 and terminates in a piston 22. For minimal operating noise and longer life the piston 22 may be made of nonmetallic material such as plastic. To minimize friction the piston 22 may be of Teflon, but other plastics such as Nylon also serve the purpose.
The piston 22 is prevented from riding down the shank by suitable means such as a shoulder (not illustrated) formed near the top of the shank. The piston is held to the top end of the shank 21 by any suitable fastening arrangement, such as peening outwardly the topmost surface of the shank 21 to form a retaining flange 23, somewhat like a rivet head.
The previously mentioned hole 24 in the shank is continued to the top of the piston 22. This hole 24 thus provides communication between the outside air below the assembly and the internal air space above the top of the piston 22. The upper end of the bushing 36 is turned down radially to form a narrow annular space within the cylindrical cavity 12. Within this narrow space is fitted the lower end of a spring 46, which pushes the piston 22 upward. (As shown in FIG. 4, the lower end of the piston 22 is also turned down radially, creating a similar annular space to receive the upper end of the spring 46.)
The top end of the internal cylindrical cavity 12 does not extend through the top of the cylinder 10, but rather terminates below a top bulkhead 19. Above this bulkhead is the support rod 31, which for strength is advantageously turned down from the same piece of metal stock as the cylinder 10. The support rod 31 too, however, is hollow. Defined in it is a central air passage 32, which extends downwardly below the top surface of the cylinder into the bulkhead 19.
Drilled laterally through the top bulkhead 19 and into the central hole 32 that is extended below the support rod is a small radial passage 13c. Intersecting this radial passage 13c is a small axial passage 15c. This axial passage 15c is drilled in the relatively thick portion 17 of the cylinder wall that is provided within the previously mentioned part 11 of the outer surface that has been left cylindrical.
The outer radial end of the radial passage 13c, and the upper axial end of the axial passage 15c are both plugged, so that the two passages 13c and 15c in series with the central hole 32 in the support rod form a closed passage from the top of the support rod to a point roughly halfway down the cylinder.
Yet another radial passage 14c is drilled through the cylinder wall, also intersecting the axial passage 15c, but lower than the previously mentioned radial passage 13c. This lower radial passage 14c is roughly halfway down the cylinder wall, and so intersects the axial passage 15c at or near the bottom end of that passage.
The outer radial end of the lower radial passage 14c, like the outer extremities of the other passages, is plugged; consequently the inside of the cavity 12--very roughly near its midpoint, vertically--is placed in sealed communication with the top end of the hole 32 in the support rod 31.
FIG. 3 illustrates that the support rod 31 of each suction foot according to my invention is to be gripped mechanically by a portion 51 of the printing press which imparts suitable motion for feeding paper or card stock. FIG. 3 also shows that a suction tube 56 from a suction bar 58 (which communicates with a pump in the printing press) is connected to the top end of the support rod 32. This setup applies suction to activate the suction foot. As will be shown, when the bottom tip of the foot (and the hood 41) contacts a piece of stock, the suction holds the paper up against the foot.
The part 51 of the press which supplies the mechanical gripping function is also shown in FIG. 4, but in a highly generalized way, and drawn broken away as at 52. A set screw 54 is typically threaded into a tapped hole 53 in the gripping mechanism 51, to secure the support rod 31 to that mechanism. The suction hose 56 is also shown in FIG. 4, but similarly drawn broken away as at 57.
(In some small presses the suction feet are screwed into a motion-imparting suction bar such as appears at 58, so that suction and motion are supplied by the same element. The support rod 31 of my invention is very readily cut to the appropriate length, and appropriately diametered and threaded, to fit into such systems.)
Now in operation the suction at hose 56 is applied through the hole 32 in the support rod, to the upper small radial passage 13c, and thence to the small axial passage 15c, and thereby finally to the lower small radial passage 14c. This suction thus is applied to the space that is (1) defined radially between the interior wall of the cylindrical cavity 12 and the outer surface of the shank 21, and (2) defined axially between the top of the fixed bushing 36 and the bottom of the piston 22.
Since the piston is movable, the applied suction tends to draw the piston downwardly against the action of the spring 46, causing the shank 21 to move downwardly from its retracted position (FIGS. 2 and 4) to an extended position (FIG. 1).
If the bottom tip of the shank, with its rubber boot 41, is now brought into contact with a sheet of stock, the degree of force associated with the contact depends not only upon the relative velocity of the support rod and the pile of stock--but also upon the effective suction force at the underside of the piston 22, in comparison with the strength of the spring 46, and to a lesser degree the force of gravity on the piston 22 and shank 21.
The forcibleness of the contact is very readily made slight, by suitable choice of various dimensions such as the diameters of the piston 22, the shank 21, and the small axial and radial passages 13c, 14c and 15c. Increasing the difference between the two first-mentioned of these diameters has the effect of making the annular area of the piston larger, which increases the downward force with which the shank 21 is held extended. Making the diameters of the passages 13c, 14c and 15c larger does likewise.
Once the foot is in contact with the stock, of course, it is desirable to apply the suction from the hose 56, through the various passages previously mentioned, to the upper surface of the top sheet of stock. This is accomplished by providing very slight suction leakage around or through the piston 22. In some cases appropriate leakage can be achieved merely by suitable selection of clearance between the outer cylindrical surface of the piston 22 and the inner cylindrical surface of the cavity 12. I prefer, however, to control the leakage more closely by providing a very fine pilot hole 27 through the shank 21 and/or the piston 22.
The suction loss through the pilot hole 27 is not enough to impair the downward extension of the boot 41 under the influence of the suction system. When the boot 41 contacts a sheet of stock, however, the suction system removes air within the cavity 24 in the shank 21, through the pilot hole 27. This air removal is enough to apply effective suction to the sheet of stock below the tip of the foot; in other words, the suction is strong enough to hold the stock up against the foot.
Furthermore, once the stock closes the bottom of the hole 24 in the shank 21, the air pressure within that hole 24--and thus the pressure in the air space 28 above the piston 22--promptly falls to very nearly the same value as the pressure within the annular cavity below the piston 22. The effect of suction on the annular or peripheral portion of the piston 22 is therefore neutralized. The spring 46, in cooperation with the suction on the central part of the piston 22 (including the part effectively provided by the sheet of stock across the hole 24 in the shank 21), raises the piston 22--and with it the shank 21, the boot 41, and the sheet of stock.
As a practical matter I find the shapes and dimensions of the preferred embodiment rather "fussy". The exterior clearances in the various small printing presses are often very small. For some particular types of press they may not be small in general, but they are certainly small under particular circumstances such as when printing short stock, or narrow stock, or wide stock.
To make a pressure foot that is commercially practical, it is necessary to make one that is usable in virtually all such cases. This means it is essential to make the exterior of the foot as small as possible. On the other hand, it is crucial to apply sufficient suction to (1) effectively extend the shank 21, and to (2) reliably, affirmatively hold each sheet of stock against the bottom tip of the shank while the stock is lifted from the pile.
In practice I have found that the above-described single series of small passages 13c, 14c and 15c, in combination with the single pilot hole 27, is only marginally sufficient to meet these requirements in enough of the many small-printing-press environments to be commercially practical.
Of course the number of passages and pilot holes cannot be sensibly considered alone. The number of such passages and holes is interrelated with the diameter of each passage and pilot hole, and with the external dimensions of the overall device. As already explained, however, it is desirable to keep the external dimensions very compact, and therefore the diameters of the passages and pilot holes must be quite small. Accordingly after very extensive effort I have settled on a preferred embodiment that has four such sets of small axial and radial passages, and four such pilot holes.
Two radial passages mentioned earlier are visible in FIG. 1 (and some of them in FIG. 2)--namely, the upper radial passages 13a and 13b, and lower radial passages 14a and 14b. In FIG. 2 another axial passage 15a and another radial passage 13d are also visible. FIGS. 5 and 6 illustrate the full complement of small axial and radial passages 13a through 13d, 14a through 14d, and 15a through 15d.
As illustrated, all the small axial and radial passages 13a through 15d are drilled through the relatively thick wall segments 17 of the cylinder 10, formed by the cylindrical portions 11 of the wall. Yet excellent exterior clearances are obtained at the two opposed very thin wall segments 18 formed by the planar-cutaway surfaces 16.
As to the pilot holes, the hole 27 appearing in FIG. 4 is continued entirely through the piston 22 and shank 21, so that it passes through both of the diametrally opposed walls of the piston and shank, forming two pilot holes. Another identical diametral hole (not illustrated) is also drilled entirely through the piston 22 and shank 21 at right angles to the first hole 27, to form two more pilot holes.
To place these configurations in perspective, and also to provide a disclosure fully adequate to permit practice of my invention by a person skilled in the general art of mechanical devices at the level of a technician or even a machinist, tne preferred embodiment of my invention is made with these dimensions, in inches:
0.99 diameter of the cylindrical portion of the outside wall of the cylinder, as measured across two opposing cylindrical surfaces 11;
0.70 thickness of the planar-cutaway portion of the outside wall of the cylinder, as measured across two opposing planar surfaces 16;
1.12 height of the cylinder block 10;
0.56 inside diameter of the cylindrical cavity 12;
0.99 axial depth of the cylindrical cavity 12;
0.38 outside diameter of the support rod 31;
0.22 inside diameter of the hole 32 in the support rod 31;
1.64 length of the support rod 31;
1.75 axial depth of the hole 32 in the support rod 31, to the bottom of the intersecting upper radial passages;
0.09 diameter of each axial or radial passage 13a through 15d;
0.31 outside diameter of the shank 21;
0.20 inside diameter of the shank 21;
1.19 overall length of the shank 21, including the section within the piston 22;
0.55 outside diameter of the piston 22;
0.06 inside diameter of each pilot hole 27; and
0.56 outside diameter of the bushing 26.
The appropriate strength of the spring 46 will vary from one press type to another, in dependence upon the strength of the associated suction system. For the ATF Chief, I have found satisfactory a spring that provides a force of approximately 0.3 ounce when the piston rod 21 is fully retracted, and a force of approximately 0.5 ounce when the piston rod 21 is fully extended. Such a spring is sufficient to lift the weight of the piston 22 and piston rod 21 (roughly 0.1 ounce), and with them the weight of half the leading edge of virtually any stock that will go through the press.
I have found that in operation my invention makes it possible for an ATF Chief press to feed any stock from very light onionskin to chipboard, without need for the slightest adjustment in suction or in pile position. In fact, it is possible to place on the stock elevator a pile containing stock of all such weights and types mixed together, and a press fitted with suction feet made as prescribed above will reliably and positively feed each piece of stock in the pile. This capability has been publicly demonstrated to professional printers, using my invention on an otherwise completely standard, typical small printing press without any type of special setup or accommodation--of either the peculiar mix of stock or the suction foot itself. Personnel familiar with the normal operating performance of such presses found this demonstration both very unusual and, literally, very surprising. In fact they reacted uniformly: they were astounded.
It is to be understood that all of the foregoing detailed descriptions are by way of example only, and not to be taken as limiting the scope of my invention--which is expressed only in the appended claims. | This suction foot or "sheet sucker" has a cylinder and a hollow piston fitted in the cylinder. The piston has a piston rod whose tip protrudes downwardly from the cylinder to apply suction to the top sheet of stock in a small press. The cylinder is supported from and moved by a hollow support rod that is connected with the suction system of the press. The piston and rod are spring-loaded upward relative to the cylinder. The hole in the support rod communicates with a point in the cylinder cavity below the piston. Applied suction consequently draws the cylinder and rod downward, against the spring action, in effect telescoping the suction foot tip outwardly toward the stock. When a sheet of stock closes the bottom end of the hollow piston and rod, pressure on the cylinder is equalized and the suction foot tip retracts, raising the stock for travel into the press. The necessary air communication is effected by several fine air passageways in the cylinder side wall and top wall. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of U.S. application Ser. No. 11/164,819 filed Dec. 7, 2005, and incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a thermally enhanced three-dimensional package, and more particularly, to a three dimensional package utilizing a heat sink on a first chip package to position another chip package.
[0004] 2. Description of the Prior Art
[0005] In conventional semiconductor packages, three dimensional packages fabricated by stacking a plurality of chip packages over one another are commonly utilized to achieve multi-functional purpose. However, as the chip packages generate large amounts of heat during operation, a heat sink is often installed to maintain the three dimensional package at a normal working temperature. Additionally, a boat is utilized to position the chip packages while stacking the chip packages over one another. This will unavoidably increase the overall cost. Moreover, a slight miscalculation in the size of the boat or the edge of the substrate of the chip packages will result in a cold joint issue and unsuccessful bonding of the chip package, and as the chip packages undergo numerous reflow processes, a warpage phenomenon will often result.
[0006] Please refer to FIG. 1 . FIG. 1 is a perspective diagram showing a cross-section of a conventional three-dimensional package. As shown in FIG. 1 , the three-dimensional package 100 includes a first chip package 110 , a second chip package 120 , a plurality of solder balls 130 , and a plurality of external conductive devices 140 . Preferably, the first chip package 110 includes a first substrate 111 and a first flip chip 112 , in which the first substrate 111 includes a top surface 113 and a bottom surface 114 . The flip chip 112 is connected to the bottom surface 114 of the first substrate 111 by utilizing a plurality of bumps 115 , in which the bumps 115 are sealed by an underfill layer 116 . Similarly, the second chip package 120 includes a second substrate 121 and a second flip chip 122 , in which the second substrate 121 includes a top surface 123 and a bottom surface 124 . The second flip chip 122 is connected to the top surface 123 of the second substrate 121 by utilizing a plurality of bumps 125 , in which the bumps 125 are sealed by an underfill layer 126 . Additionally, the solder balls 130 are formed between the top surface 113 of the first substrate 111 and the bottom surface 124 of the second substrate 121 to electrically connect the first chip package 110 and the second chip package 120 , and the external conductive devices 140 are disposed on the bottom surface 114 of the first substrate 111 for connecting to other electronic devices (not shown).
[0007] Essentially, the first chip package 110 and the second chip package 120 of the three-dimensional package 100 often generate significant amounts of heat during operation thereto reducing the performance of the device as a result of overheating. Additionally, phenomenon such as warpage occurs frequently on the first chip package 110 and the second chip package 120 and influences the structural sturdiness and electrical transmission of the three-dimensional package 100 . Furthermore, when the first chip package 110 and the second chip package 120 are stacked over each other, a boat is commonly utilized to position the first chip package 110 and the second chip package 120 , thereby increasing cost and reducing over yield.
SUMMARY OF THE INVENTION
[0008] It is therefore an objective of the present invention to provided a thermally enhanced three-dimensional package. Preferably, the thermally enhanced three-dimensional package includes a heat sink, a first chip package, and a second chip package, in which the heat sink includes an opening and a stiffener ring inside the opening. A first substrate of the first chip package is positioned in the opening and secured on a first surface of the stiffener ring, and a second substrate of the second chip package is secured on a second surface of the stiffener ring. By utilizing the stiffener ring to secure the first chip package and the second chip package, the present invention is able to prevent the warpage phenomenon of the first chip package and the second chip package.
[0009] It is another aspect of the present invention to provide a thermally enhanced three-dimensional package. Preferably, the thermally enhanced three-dimensional package includes a heat sink having an opening and a stiffener ring inside the opening, a first chip package disposed on a first surface of the stiffener ring, and a second chip package disposed on a second surface of the stiffener ring, such that the heat generated by the first chip package and the second chip package during operation can be dissipated via the heat sink.
[0010] It is another aspect of the present invention to provide a thermally enhanced three-dimensional package. Preferably, the thermally enhanced three-dimensional package includes a heat sink having an opening and a stiffener ring inside the opening, a first chip package disposed on a first surface of the stiffener ring, and a second chip package disposed on a second surface of the stiffener ring, in which the stiffener ring is utilized to control the height of the solder balls between the first chip package and the second chip package, thereby preventing a solder failure or a broken circuit.
[0011] It is another aspect of the present invention to provide a method of fabricating a thermally enhanced three dimensional package, the method includes: providing a first chip package, wherein the first chip package comprises a first substrate; disposing a heat sink having a first opening and a stiffener ring inside the first opening on the first chip package, wherein the stiffener ring comprises a first surface and a second surface and the first substrate of the first chip package is disposed in the opening of the heat sink and secured to the first surface of the stiffener ring; disposing a second chip package having a second substrate on the heat sink, wherein the second substrate is secured to the second surface of the stiffener ring; and performing a reflow process for forming a plurality of solder balls between the first substrate and the second substrate, wherein the solder balls are formed inside the stiffener ring for connecting the first substrate and the second substrate.
[0012] According to the present invention, a thermally enhanced three dimensional package includes: a heat sink having a first opening and a stiffener ring inside the opening, in which the stiffener ring comprises a first surface and a second surface; a first chip package having a first substrate, in which the first substrate is disposed in the opening of the heat sink and secured to the first surface of the stiffener ring; a second chip package having a second substrate, in which the second substrate is secured to the second surface of the stiffener ring; and a plurality of solder balls disposed between the first substrate of the first chip package and the second substrate of the second chip package and inside the stiffener ring for connecting the first substrate and the second substrate. Preferably, the heat sink is utilized to position and facilitate the stacking of the first chip package and the second chip package, and the stiffener ring is utilized to secure the first chip package and the second chip package for preventing a warpage phenomenon and facilitating the heat dissipation of the two package structures.
[0013] 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
[0014] FIG. 1 is a perspective diagram showing a cross-section of a conventional three-dimensional package.
[0015] FIG. 2 is a perspective diagram showing the cross-section of a thermally enhanced three-dimensional package according to the first embodiment of the present invention.
[0016] FIG. 3 is a three-dimensional diagram showing the heat sink of FIG. 2 .
[0017] FIG. 4 through FIG. 6 are perspective diagrams showing a means of fabricating the thermally enhanced three-dimensional package 200 according to the first embodiment of the present invention.
[0018] FIG. 7 is a perspective diagram showing the cross-section of a thermally enhanced three-dimensional package according to the second embodiment of the present invention.
[0019] FIG. 8 is a perspective diagram showing the cross-section of a thermally enhanced three-dimensional package according to the third embodiment of the present invention.
[0020] FIG. 9 is a perspective diagram showing the cross-section of a thermally enhanced three-dimensional package according to the fourth embodiment of the present invention.
DETAILED DESCRIPTION
[0021] Please refer to FIG. 2 and FIG. 3 . FIG. 2 is a perspective diagram showing the cross-section of a thermally enhanced three-dimensional package according to the first embodiment of the present invention and FIG. 3 is a three-dimensional diagram showing the heat sink from FIG. 2 . As shown in FIG. 2 and FIG. 3 , a thermally enhanced three-dimensional package 200 includes a heat sink 210 , a first chip package 220 , a second chip package 230 , and a plurality of solder balls 240 . Preferably, the heat sink 210 includes an I-shaped cross-section, an opening 211 , and a stiffener ring 212 inside the opening 211 , in which the stiffener ring 212 is monolithically formed on the heat sink 210 . Additionally, the stiffener ring 212 includes a first surface 213 and a second surface 214 , such that the opening 211 exposes the first surface 213 and the second surface 214 . The first chip package 220 includes a first substrate 221 having a top surface 222 and a bottom surface 223 , in which the first substrate 221 is disposed in the opening 211 of the heat sink 210 and secured to the first surface 213 of the stiffener ring 212 by utilizing an adhesive 250 , thereby preventing the first substrate 221 of the first chip package 220 from suffering from the warpage phenomenon. The first chip package 220 also includes a first chip 224 and a plurality of bumps 225 . According to the present embodiment, the first chip 224 is connected to the bottom surface 223 of the first substrate 221 by a flip chip packaging process, the bumps 225 are electrically connected to the bottom surface 223 of the first substrate 221 , and an underfill layer 226 is formed to seal the bumps 225 . Additionally, the thermally enhanced three-dimensional package 230 includes a plurality of external conductive devices 260 , such as solder balls or pins, in which the external conductive devices 260 are disposed on the bottom surface 223 of the first substrate 221 and exposed from the opening 211 of the heat sink 210 to provide an external connection to other electronic devices (not shown).
[0022] The second chip package 230 includes a second substrate 231 having a top surface 232 and a bottom surface 233 . Preferably, the second substrate 231 is disposed on the second surface 214 of the stiffener ring 212 , in which the second substrate 231 is secured to the second surface 214 by another adhesive 250 for preventing warpage of the second substrate 231 . The second chip package 230 also includes a second chip 234 , such as a flip chip and a plurality of bumps 235 , in which the second chip 234 is electrically connected to the top surface 232 of the second substrate 231 by utilizing the bumps 235 , and an underfill layer 236 is formed to seal the bumps 235 thereafter.
[0023] The solder balls 240 are formed between the first substrate 221 of the first chip package 220 and the second substrate 231 of the second chip package 230 and inside the stiffener ring 212 of the heat sink 210 , such that the solder balls 240 are utilized to connect the first substrate 221 and the second substrate 231 , and facilitate the stacking of the first chip package 220 and the second chip package 230 . Preferably, the height of the solder balls 240 can be adjusted via the stiffener ring 212 , thereby preventing a solder failure or a broken circuit.
[0024] By utilizing the heat sink 210 to position the first chip package 220 and the second chip package 230 , the present invention requires no additional boat as in the prior art. Additionally, the first chip package 220 and the second chip package 230 are secured on the stiffener ring 212 to prevent the warpage phenomenon. Furthermore, the heat generated by the first chip package 220 and the second chip package 230 during operation can be transmitted via the first substrate 221 of the first chip package 220 , the second substrate 231 of the second chip package 230 , and the stiffener ring 212 to the heat sink 210 , such that the heat will be dissipated by the heat sink 210 .
[0025] Please refer to FIG. 4 through FIG. 6 . FIG. 4 through FIG. 6 are perspective diagrams showing a means of fabricating the thermally enhanced three-dimensional package 200 according to the first embodiment of the present invention. As shown in FIG. 4 , a first chip package 220 having a first substrate 221 and a first chip 224 is first provided. Preferably, the first substrate 221 includes a top surface 222 and a bottom surface 223 , in which the first chip 224 is attached to the bottom surface 223 of the first substrate 221 by utilizing a plurality of bumps 225 . Next, a plurality of solder bumps 240 a is formed on the top surface 222 of the first substrate 221 .
[0026] As shown in FIG. 5 , a heat sink 210 , such as the one shown in FIG. 3 , is disposed on the top surface 222 of the first chip package 220 . Preferably, the heat sink 210 includes an opening 211 and a stiffener ring 212 inside the opening 211 , in which the stiffener ring 212 includes a first surface 213 and a second surface 214 . Subsequently, an adhesive 250 is applied on the stiffener ring 212 for attaching the first substrate 221 on the first surface 213 of the stiffener ring 212 .
[0027] As shown in FIG. 6 , a second chip package 230 having a second substrate 231 and a second chip 234 is disposed on the stiffener ring 212 of the heat sink 210 . Preferably, the second chip package 230 includes a second substrate 231 and a second chip 234 , in which the second chip 234 is connected to the top surface 232 of the second substrate 231 by utilizing the plurality of bumps 235 . Additionally, an adhesive 250 is formed to attach the second chip package 230 on the second surface 214 of the stiffener ring 212 , and a plurality of second solder bumps 240 b is formed on the bottom surface 233 of the second substrate 231 . Preferably, the heat sink 210 is utilized to position the first chip package 220 and the second chip package 230 , such that the second solder bumps 240 b of the second chip package 230 can be aligned corresponding to the first solder bumps 240 a of the first chip package 220 . Subsequently, a soldering flux 270 is formed on the first solder bumps 240 a or the second solder bumps 240 b to facilitate the melting of the first solder bumps 240 a and the second solder bumps 240 b during a reflow process for producing a plurality of solder balls 240 (as shown in FIG. 2 ). Preferably, the height of the stiffener ring 212 of the heat sink 210 is controlled corresponding to the height of the solder balls 240 between the first chip package 220 and the second chip package 230 to prevent a solder failure or a broken circuit. Subsequently, a plurality of external conducting devices 260 is disposed on the bottom surface 223 of the first substrate 221 and exposed from the opening 211 of the heat sink 210 for forming a thermally enhanced three-dimensional package 200 (as shown in FIG. 2 ).
[0028] Please refer to FIG. 7 . FIG. 7 is a perspective diagram showing the cross-section of a thermally enhanced three-dimensional package 300 according to the second embodiment of the present invention. As shown in FIG. 7 , the thermally enhanced three-dimensional package 300 includes a heat sink 310 , a first chip package 320 , a second chip package 330 , and a plurality of solder balls 340 , in which the heat sink 310 includes an opening 311 and a stiffener ring 312 inside the opening 311 . According to the present embodiment, the stiffener ring 312 is step-shaped, in which the stiffener ring 312 also includes a first surface 313 and a second surface 314 , and both the first surface 313 and the second surface 314 expose the opening 311 . Preferably, the first chip package 320 is disposed in the opening 311 , in which the first chip package 320 includes a first substrate 321 and a first chip 324 . Additionally, the first substrate includes a top surface 322 and a bottom surface 323 , in which the first substrate 321 is positioned in the opening 311 of the heat sink 310 and secured on the first surface 313 of the stiffener ring 310 . The first chip 322 is connected to the bottom surface 323 of the first substrate 321 by utilizing a plurality of bumps 325 , and an underfill layer 326 is formed to seal the bumps 325 .
[0029] The second chip package 330 includes a second substrate 331 and a second chip 334 . Preferably, the second substrate 331 includes a top surface 332 and a bottom surface 333 , in which the second substrate 331 is disposed in the opening 311 of the heat sink 310 and secured on the second surface 314 of the stiffener ring 312 . The second chip 334 is attached to the top surface 332 of the second substrate 314 by utilizing a plurality of bumps 335 , and an underfill layer 336 is formed to seal the bumps 335 . The solder balls 340 are disposed between the top surface 322 of the first substrate 321 and the bottom surface 333 of the second substrate 331 , the first chip package 320 is secured on the first surface 313 of the stiffener ring 312 , and the second chip package 330 is secured on the second surface 314 of the stiffener ring 312 to facilitate the alignment of the first chip package 320 and the second chip package 330 while stacking the packages over each other. Preferably, the present invention is able to utilize the stiffener ring 313 to secure the first chip package 320 and the second chip package 330 to prevent warpage of the two packages, utilize the heat sink 310 of the stiffener ring 312 to dissipate heat, and utilize the step-shaped stiffener ring 312 to control the height of the solder balls 340 between the first chip package 320 and the second chip package 330 for preventing a solder failure or a broken circuit.
[0030] Please refer to FIG. 8 . FIG. 8 is a perspective diagram showing the cross-section of a thermally enhanced three-dimensional package 400 according to the third embodiment of the present invention. As shown in FIG. 8 , the thermally enhanced three-dimensional package 400 includes a heat sink 410 , a first chip package 420 , a second chip package 430 , and a plurality of solder balls 440 . Preferably, the heat sink 410 includes an opening 411 and a stiffener ring 412 inside the opening 411 , in which the stiffener ring 412 includes a first surface 413 and a second surface 414 , such that the first surface 413 and the second surface 414 expose the opening 411 .
[0031] The first chip package 420 includes a first substrate 421 , a first chip 422 , a plurality of wires 423 , and a sealing compound 424 , in which the first substrate 421 includes a top surface 425 and a bottom surface 426 . The first chip 422 is disposed on the top surface 425 , in which the first chip 422 is electrically connected to the first substrate 421 via the wires 423 , and the sealing compound 424 is utilized to seal the first chip 422 and the wires 425 . Preferably, the first substrate 421 is contained in the opening 411 of the heat sink 410 and secured to the first surface 413 of the stiffener ring 412 , in which an adhesive 450 is disposed to secure the bonding of the stiffener ring 412 and the first substrate 421 and prevent warpage of the first substrate 421 . Additionally, the thermally enhanced three-dimensional package 400 includes a plurality of external conductive devices 460 , such as solder balls. As shown in FIG. 8 , the external conductive devices 460 are disposed on the bottom surface 426 of the first substrate 421 and exposed from the opening 411 of the heat sink 410 .
[0032] The second chip package 430 includes a second substrate 431 , a second chip 432 , a plurality of wires 433 , and a sealing compound 434 , in which the second substrate 431 includes a top surface 435 and a bottom surface 436 . The second chip 432 is disposed on the top surface 435 of the second substrate 431 and electrically connected to the second substrate 431 via the wires 433 , and the sealing compound 434 is formed on the top surface 435 of the second substrate 431 to seal and protect the second chip 432 and the wires 433 . The second substrate 431 is secured on the second surface 414 of the stiffener ring 412 , in which an adhesive 450 is disposed on the second surface 414 of the stiffener ring 412 to prevent the second substrate 431 of the second chip package 430 from suffering from the warpage phenomenon.
[0033] The solder balls 440 are formed between the top surface 425 of the first substrate 421 and the bottom surface 436 of the second substrate 431 and on the periphery of the first chip 422 , in which the solder balls 440 are utilized to electrically connect the first substrate 421 and the second substrate 431 . Preferably, the thermally enhanced three-dimensional package 400 is able to utilize the stiffener ring 412 to control the height of the solder balls 440 to prevent a solder failure or a broken circuit, and utilize the heat sink 410 to dissipate the heat generated during the operation of the first chip package 420 and the second chip package 430 .
[0034] Please refer to FIG. 9 . FIG. 9 is a perspective diagram showing the cross-section of a thermally enhanced three-dimensional package 500 according to the fourth embodiment of the present invention. As shown in FIG. 9 , the thermally enhanced three-dimensional package 500 includes a heat sink 510 , a first chip package 520 , a second chip package 530 , and a plurality of solder balls 540 , in which the heat sink 510 includes an opening 511 and a first surface 512 and a second surface 513 inside the opening 511 . According to the present embodiment, the opening 511 exposes the first surface 512 and the second surface 513 and forms a step shape.
[0035] The first chip package 520 includes a first substrate 521 , a first chip 522 , a plurality of wires 523 , and a sealing compound 524 , in which the firs substrate 521 includes a top surface 525 and a bottom surface 526 . The first chip 522 is disposed on the top surface 525 of the first substrate 521 and electrically connected to the first substrate 521 via the wires 523 , in which the sealing compound 524 is utilized to seal the first chip 521 and the wires 523 . When the first chip package 520 is bonded to the heat sink 510 , the first substrate 521 is positioned on the first surface 512 of the heat sink 510 . Additionally, a plurality of external conductive devices 550 is disposed on the bottom surface 526 of the first substrate 521 and exposed from the opening 511 of the heat sink 510 for connecting to other electronic devices (not shown).
[0036] The second chip package 530 includes a second substrate 531 , a second chip 532 , a plurality of wires 533 , and a sealing compound 534 . The second chip 532 is disposed on a top surface 535 of the second substrate 531 , the wires 533 are utilized to electrically connect the second substrate 531 and the second chip 532 , and the sealing compound 534 is formed to seal the second chip 532 and the wires 533 . When the second chip package 530 is bonded to the heat sink 510 , the second substrate 531 is disposed on the second surface 513 of the heat sink 510 . Since the first chip package 520 is secured to the first surface 512 of the heat sink 510 and the second chip package 530 is secured to the second surface 513 of the heat sink 510 , the present invention is able to accurately align and stack the packages over each other, thereby preventing the warpage phenomenon and utilizing the heat sink effectively. Additionally, by controlling the height of the heat sink 510 corresponding to the height of the solder balls 540 between the first chip package 520 and the second chip package 530 , the present invention is able to prevent a solder failure or a broken circuit.
[0037] 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 thermally enhanced three-dimensional (3D) package is disclosed. The package includes a heat sink having an opening and a stiffener ring inside the opening. The stiffener ring has a first surface and a second surface. A first substrate of a first package is disposed inside the opening and secured to the first surface of the stiffener ring. A second substrate of a second chip package is secured to the second surface of the stiffener ring. The first substrate is connected to the second substrate through a plurality of solder balls. The heat generated in the first chip package and the second chip package is dissipated by the heat sink. The first chip package and the second chip package are fixed by the stiffener ring to eliminate warpage of the first chip package and the second chip package, thereby assuring the electrical transmission of the product. | 7 |
The present invention relates to a novel optical recording medium containing graphite as the storage material, a process for its preparation and its use as a Read Only Memory information carrier.
BACKGROUND OF THE INVENTION
A large number of materials have been described as optical storage media for analog or digital storage of information with the aid of a laser beam. The information is written into the particular storage medium in the form of holes, pits or bubbles or by phase transformations or other local changes in properties. Storage media which have been described are thin layers of inorganic materials, such as metals, alloys, doped metals, metal oxides or metal sulfides, and of organic compounds, in particular dyes, but also liquid crystal compounds or polymers and combinations of these.
Dyes have a high absorption which can be optimized for the relevant laser wavelength, and are distinguished by low thermal conductivity and a variety of possible methods of processing, (eg. vaporization under reduced pressure, or spincoating with or without a binder or other additives). Their optical data (real and imaginary part of the refractive index [n,k]λ) are generally inadequate, so that a high quality memory can be obtained only with matched layer thicknesses or with an additional reflector layer. Moreover, only a few suitable IR dyes are known which absorb sufficiently in the near infrared region (750-900 nm), i.e. in the spectral range in which the technically advantageous semiconductor lasers of the GaAlAs type emit light, and which are used for writing on and reading optical recording media in a reasonable manner. Hence, optimization of such systems requires additives, such as carbon black or oxygen quenchers, which have a synergistic effect but also complicate the preparation of the storage layers.
Although thin metal layers, in particular tellurium and its alloys, and modified materials based on tellurium exhibit suitable optical data (adequate absorption and reflection) in a wide wavelength range, they have relatively high thermal conductivities and are generally very sensitive to corrosion.
It is an object of the present invention to provide a novel optical recording medium, starting from a material which has adequate reflection, is easy to process and has high stability under the conditions of use.
Graphite, which has a layer structure and hence possesses properties of organic and inorganic (metallic) materials, should constitute a suitable storage material.
DE-A-2 150 134 describes an optical recording medium which consists of a thin layer (about 0.5-1.0 μm) of carbon black particles in a polymeric binder, preferably plasticized nitrocellulose, on a heat-resistant substrate (glass). The layer material is selectively vaporized or burned away at the irradiated points by means of a laser beam, and in this way an image is produced.
However, we have found that binder-containing carbon black layers which have been sprayed on have only a low reflectivity owing to the surface roughness; hence, high quality storage media are obtained only with matched layer thicknesses coupled with complete removal of material, and the information density remains restricted (as a result of the large signal area and signal spacing).
SUMMARY OF THE INVENTION
We have found that the above stated object of the present invention is achieved by an optical recording medium containing a storage layer and, if required, one or two substrate layers, wherein the storage layer contains graphite as the storage material.
We have furthermore found that, using compressed graphite, it is possible to achieve dramatic improvements in quality, regardless of the layer thickness. Moreover, simple methods can be employed for the preparation of the storage layer.
Because of the high corrosion resistance (chemical stability) of graphite, its stability under conditions of use and its toxicological acceptability, the system is ideally suited to a wide range of applications in the data storage sector and for other recording media. Furthermore, graphite in the form of high quality films is particularly advantageous as a storage material because the surface quality results in high light reflectivity over a wide wavelength range. Consequently, the storage material is independent of the wavelength of the laser light used.
The novel optical recording medium is advantageously obtained if a blank having a diameter of from 10 to 30 cm is stamped out of a graphite film, and the said blank is then pressed under from 300 to 8,000, preferably from 500 to 5,000, in particular from 700 to 1,000, bar and, if required, then provided with one or two substrate layers in a further pressing process.
The novel process is advantageously carried out as follows: disks having a diameter of from 10 to 30 cm are pressed out from a prepressed film of graphite, and these disks are then pressed in a press tool. Commercial, prepressed films of graphite in pure or fiber-reinforced form (also see Ullmanns Encyklopadie der technischen Chemie, 4th edition, volume 14, page 616), as also used, for example, for the production of seals for chemical apparatuses, are advantageously employed. The pressing process is usually carried out at room temperature. The optimum pressure in each case depends on the type of film material used and on the area of the graphite disk. In the pressing process, the preoriented graphite domains (layer structures) are further oriented and the surface homogenized, a metallic gloss being produced. This layer itself can be written on by means of a laser beam. The properties of this memory are in general dependent only on the surface quality and not on the layer thickness.
For mechanical stabilization, this graphite layer may be provided with one or two substrate layers. These also afford mechanical protection to the surface and hence to the stored information.
Suitable substrate layers are all those materials (glass and polymer materials) which have adequate optical properties. Substrate layers made of polymer material are preferably used, those which essentially consist of polymethyl methacrylate or polycarbonate being particularly preferred.
In a second pressing process under similar compression conditions, the substrate layers, for example in the form of diskettes 0.2 cm thick, can be pressed onto the graphite layer. To achieve optimum adhesion of the substrate layer or layers to the graphite, it may be advantageous additionally to use an adhesive to bond the substrate layer or layers. Suitable adhesives in this context are the conventional materials, as described in, for example, Ullmanns Encyklopadie der technischen Chemie, 4th edition, volume 14, page 227 et seq.
It is also possible to use substrate layers which have been provided with grooves beforehand, in order to permit guidance over the tracks and rapid data access. Depending on the conditions under which the memory is produced, the grooves in the substrate may remain empty or may be filled with a material (eg. adhesive) having a high refractive index.
However, it is also possible to carry out a second pressing process in which substrate layers are not applied to the graphite storage material. In this case, instead, track information can be introduced onto the graphite layer in the second pressing process, by using a master. The substrate layers can then additionally be pressed on.
We have found, surprisingly, that the thermoconductivity of the storage layer (λ>200 W/mK, in the layer direction), which has a high anisotropy coefficient (about 30) owing to the layer structure, does not have an adverse effect if exposure is carried out using relatively short laser pulses.
For archiving large amounts of data and information, there is a growing demand for systems which permit this to be done within a very small space and with a very short access time. The refinement of semiconductor laser technology has given rise to the development of optical storage media and of read and write apparatuses which are superior to the conventional magnetic media in many respects.
Optical storage media known in principle are readable media (Read Only Memories, ROM), media which can be written once and are readable (Write Once Read Many, WORM) and erasable media. However, they are very expensive to produce. This applies both to the production and purification of the storage materials used and to the production of the memory (thin film technology, e.g. sputtering, vaporization under reduced pressure or spin-coating with defined layer thicknesses). Moreover, many storage materials present problems with regard to long-term stability because they are sensitive to oxidation or morphologically unstable (recrystallization of amorphous layers).
In addition to tapes and cards, Compact Disc Read Only Memories (CD-ROM) are particularly suitable for the abovementioned archiving of documentation, since such memories are capable of storing a large amount of data and information within a very small space, and the said data and information can be called up as often as desired and in a short access time. Furthermore, they have good long-term stability.
Optical ROMs known to date consist of a substrate (polymer or glass with a photoresist layer) which contains the information and is provided with a thin metal layer (preferably aluminum), with the result that the scanning laser beam is reflected.
It is a further object of the present invention to provide a cheap storage medium in which the expensive reflector layer (vaporization under reduced pressure) can be dispensed with.
We have found that this object too is achieved, and that the novel optical recording medium can advantageously be used as a Read Only Memory information carrier, the latter advantageously being in the form of compact disks, cards or tapes. Compact disks and cards may be mentioned in particular.
ROM information carriers in the form of compact disks are obtained, for example, if the information to be stored is pressed into the graphite disks described above by means of a master. To protect the surfaces (information) and to impart mechanical stability, this graphite layer may, according to the invention, be provided with one or two substrate layers.
Furthermore, ROM information carriers in the form of a card (for example, measuring 8.5×5.4 cm) can be obtained in a similar manner.
Tapes having a graphite-containing layer can be produced, for example, in a manner similar to that used for tapes containing a magnetic pigment layer, with or without the addition of assistants, e.g. binders.
This very simple procedure gives a cheap storage medium which is mechanically, thermally and chemically very stable and furthermore can be read by means of laser beams in a wide wavelength range and having different light-energies.
FIG. 1 of the accompanying drawing is a cross sectional view of a disc 1 formed from a further pressed prepared film of graphite.
FIG. 2 is a cross sectional view of such a disc 1 sandwiched between two MMA diskettes 2 and 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The Examples which follow illustrate the invention.
EXAMPLE 1
A graphite disk having a diameter of 10 cm was pressed under 750 bar in a press tool having a centered inner hole. The graphite layer thus obtained was readily removed from the press tool and exhited a pronounced metallic gloss. This layer had a reflectivity of from 30 to 35% over a wide wavelength range.
A binder-containing graphite layer sprayed onto glass served as the comparison. The reflectivity values of this layer were substantially poorer, both in the untreated state (rough surface) and after slight polishing (smooth surface).
Signals were written into the novel recording medium at various wavelengths by means of short light pulses, using a focussed laser beam. The magnitude of the signals was dependent on the energy density and could be controlled by means of the laser energy and focus or time. Signals are distinguished from the smooth (unwritten) environment because of the change in reflectivity. This differentiation takes the form of small depressions, due to local vaporization of graphite, or thermally induced roughening of the previously smooth graphite surface or a combination of the two effects. By exposure to a pulsed dye laser, it was possible to inscribe signals which were sufficiently large (diameter up to 0.3 mm) to permit contrast measurement using a microscope and spectrometer coupled by means of glass fibers. For reflection at 830 nm, the differences in the reflectivity of the signal (13%) and that of the environment (33%) gave a contrast of 20%.
EXAMPLE 2
A graphite storage layer was produced similarly to Example 1 and, in a second operation, pressed together with a polymethyl methacrylate (PMMA) diskette (thickness 1 mm, diameter 10 cm, centered inner hole of 15 mm diameter) in such a way that the substrate was not deformed. In order to join the two layers together in a stable manner, the outer and inner edges were adhesively bonded.
The storage layer could readily be written on from the free side (facing the air) and from the substrate side (facing PMMA). The contrast was the same on both sides, within the error limits, and the micrographs of the signals showed no significant differences. Measurement of the signal-to-noise ratio for a non-optimized storage layer of average quality gave a value which was 2.5 times that of a tellurium layer applied by vapor deposition.
EXAMPLE 3
Graphite storage layers were produced similarly to Example 1 and, in a second operation, adhesively bonded between two PMMA diskettes (cf. Example 2) and/or clamped with inner and outer retaining rings. This gave protected sandwich stores in which the two sides were identical. The recordability and quality were similar to those of the samples described in Examples 1 and 2, while the mechanical stability was substantially higher.
EXAMPLE 4
The graphite storage layer was produced similarly to Example 1 (diameter 13 cm) and, in a second operation similar to Example 3, adhesively bonded between two polycarbonate diskettes having a diameter of 13 cm and possessing grooves. The recordability and quality were similar to those of the above examples.
EXAMPLE 5
A graphite store was produced similarly to Example 4, except that the substrate used comprised two polycarbonate diskettes possessing grooves which had been filled with a binder-containing dye solution by spin-coating, the binder-containing dye layer having a substantially higher refractive index than the polycarbonate. The test results were similar to those obtained for a store described in Example 4.
EXAMPLE 6
A graphite layer was produced similarly to Example 1. In a second operation, vanadyl phthalocyanine was applied as a dye by vapor deposition, on one side in case (a) and on both sides in case (b). In a third step, the substrate (PMMA diskettes) was applied to each dye layer by a method similar to that described in Examples 3 to 5. In comparison with conventional storage media, in this system the graphite layer served as both absorber and reflector. Recordability at a laser wavelength matched with the absorption maximum of the dye was achieved at lower energy densities.
EXAMPLE 7
Disks having a diameter of 10 cm were punched out from a 0.2 mm thick graphite film. These blanks were pressed under 750 bar in a press tool having a centered inner hole. The graphite layer obtained in this manner was readily removed from the press tool and had a basic reflectivity of from 30 to 35% in the wavelength range from 500 to 1200 nm. This graphite disk was pressed together with a bottom die in an appropriate press tool, the information present on the bottom die being transferred to the graphite surface (in the form of depressions). The graphite disk (information carrier) was removed from the press tool and adhesively bonded between two 1.2 mm thick PMMA disks of 10 cm diameter under slight pressure (about 50 bar). The information was read from this store by means of a pulsed dye laser (λ W =740 nm). The contrast determined by means of a microscope coupled to a spectrometer (reflectivity [environment]-reflectivity [information]) was from 10 to 20%. The information was retained unchanged in all stability tests (exposure to heat, moisture and solvents), which the substrate withstood.
EXAMPLE 8
A graphite disk having a basic reflectivity of about 30% was produced from a 0.1 mm thick graphite film similarly to Example 7. This disk was placed in a press tool having 2 dies (bottom and cover) and pressed under about 1000 bar. The graphite disk containing information on both sides was further processed as described in Example 7 and exhibited the same properties while possessing twice the storage capacity.
EXAMPLE 9
A CD-ROM based on graphite was produced similarly to Example 8, but had a diameter of 13 cm and was mechanically protected by being adhesively bonded to two polycarbonate disks. The store exhibited the same properties as the systems described in Examples 7 and 8.
EXAMPLE 10
A CD-ROM produced similarly to Example 9 was read using an HeNe laser.
EXAMPLE 11
A CD-ROM produced similarly to Example 9 was read using a GaAlAs semiconductor laser. The wavelengths used were 780 nm and 830 nm.
EXAMPLE 12
A CD-ROM produced similarly to Example 9 was read using an Nd-YAG laser.
EXAMPLE 13
Example 7 was repeated, a card measuring 8.5×5.4 cm being used instead of a disk. | An optical recording medium containing a storage layer and, if required, one or two substrate layers, the storage layer containing graphite as the storage material, a process for the production of the novel optical recording medium, and its use as a Read Only Memory information carrier. | 6 |
CROSS REFERENCES TO RELATED APPLICATIONS
This application is a continuation-in-part application of parent application Ser. No. 14,984 filed in the U.S. Patent Office on Feb. 26, 1979 now abandoned.
FIELD OF THE INVENTION
The invention, primarily relates to a mud flap guard assembly, mountable on the rear portion of a truck chassis, extending vertically behind and overlapping a portion of its rear wheel. The mud flap, as a part of the assembly, is so mounted thereto, that it automatically releases itself undamaged from its mount, when, e.g., caught under or between the rear wheel and the lower portion of a loading dock; it may then be remounted on the chassis in a matter of seconds. The generally used types of mud guards are simply bolted to the chassis and may be ripped off or damaged when squeezed between a rear wheel and externally protruding objects. In some instances these mud guards, then become completely torn and are not reusable. If reusable, their remounting on the chassis is time consuming, and sometimes costly, when, e.g., union regulations require that the remounting must be done by an auto shop.
SUMMARY OF THE INVENTION
As noted above the invention relates to a resilient mud guard bracket, mounted on the rear chassis of a truck, from which a releasable flap extends downwardly vertical, overlapping a back portion of one rear wheel.
As also noted above, one of the problems with respect to the conventional type mud guards is that its flap is bolted on the chassis of the vehicle and cannot properly cope with a downward stress or pull exerted on same, when for example caught under or between the rear wheel and the edge of a loading dock. When a pulling force is exerted on the conventional flap, the latter may tear off from the bracket and must be replaced by a new flap. Past attempts to rectify such drawbacks, as noted above, consisted of complicated devices, comprising several moving parts, which are costly to manufacture and difficultly maintained, particularly under unfavorable weather conditions.
It is, therefore an object of the invention to provide a mud guard assembly which merely may comprise two basic parts, namely a resilient bracket to which a mud flap is attached automatically releasable.
It is another object of the invention to provide a mud guard, which, subsequent to its automatic release from the bracket, may again be inserted quickly into the bracket.
It is further object of the invention to provide means for utilizing existing conventional mud flaps as part of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective front view of a mud guard assembly.
FIG. 2 is a perspective view of the mud guard assembly.
FIG. 3 is a perspective view of a flap detached from the mount of the mud guard assembly.
FIG. 4a, b and c are an exploded perspective view of a modified mud guard assembly according to the invention, a bracket mount for the mud guard, an intermediate section, insertable in the mount, and the upper portion of a conventional flap mountable on the intermediate section.
FIG. 5 is a perspective front view of a modified version of a bracket portion of the mud guard assembly.
FIG. 6 is a perspective front view of other bracket portions, which, when combined with bracket portion of FIG. 5, constitute a complete bracket mount for the mud flap, according to the invention.
FIG. 7 is a side view of the complete mud guard assembly, utilizing the bracket portions, as illustrated in FIGS. 5 and 6.
FIG. 8 is a fragmentary perspective view of the mud guard assembly in FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the drawings like reference characters designate similar parts in the illustrated views.
Referring now in detail to FIG. 1 of the drawings, numeral 10 designates the mud guard assembly, according to the invention, mountable on the back of a vehicle chassis, indicated by 12, by means of holding means, e.g., a bracket 14, the upper part of which is apertured at 16, where bolts 18 (or any other suitable fastening means) may pass through and into the chassis section, indicated by 12 for secure attachment thereto.
Bracket 14 bifurcated into converging curved sections 14a, 14b, forming a circular space therewithin, with their lower edges defining a longitudinal slot 14c extending along the entire length of bracket 14, as is clearly seen in FIG. 2. It is essential to my invention that at least one of the bifurcated sections 14a, or 14b is made of a resilient material, e.g., rubber, plastic or a springy metal such as carbon steel, as will be explained in detail in the following. Furthermore, bracket 14 may be cast or manufactured in one integral piece or in two halves, as indicated by dotted lines 14d.
Mud guarding means, e.g., a flap 20 (constituting the actual mud guard element) consists, preferably of a rectangular section of flexible material, such as board, plastic, rubber, etc., the upper portion of which terminates in a tubular member, e.g., a lug 20a. The diameter of lug 20a is somewhat smaller than that of the interior of the bifurcated sections 14a, b of bracket 14, (FIGS. 2 and 3).
The dimensions of bracket 14a, b and flap 20, obviously vary according to the size of the vehicle on which the mud guard is used, e.g., trailers, trucks, etc. However, the preferred average diameter of the interior space of bracket 14a, b is 1", and of the flap lug 20a; 7/8 or 3/4 of an inch.
In order to assemble the mud guard, according to the invention, upper portion of bracket 14 is, as noted above, bolted to the rear of chassis 12. The resiliency of bifurcated bracket portion(s) 14a and/or 14b is such, that lug 20a of flap 20, being turnably accommodated within sections 14a, b, may be drawn downwardly through and beyond widening slot 14c, when a sufficient pulling force is exerted thereon, e.g., when flap 20 is caught between the rear truck wheel and the side of a loading dock, that is to say, the resilient bracket portion(s) will yield to the pull of flap 20 and cause the latter to escape therefrom.
The diameter of lug 20a relative to slot 14c of bracket 14 is such, that it cannot escape there through unless there is exerted a sufficiently great downward pull on flap 20, which will widen slot 14c to permit passage of lug 20a. Once flap 20 is pulled out of the converging bracket sections 14a, b, it may be reinserted in a matter of seconds through slot 14c, as explained above.
One inlet opening 14e to bracket sections 14a, b (one of which is shown in FIG. 2) accommodates stopping means, e.g., two oppositely and vertically disposed thin circular segments 14f, partially blocking the entrances to bracket sections 14a, b. The object of the arrangement of segments 14f is to prevent inserted lug 20a of flap 20 from laterally escaping from bracket sections 14a, b except when the width of slot 14c is widened sufficiently to permit its insertion or escape from bracket sections 14a, b, as explained above. The width of segments 14f, respectively is preferably about 1/8 of an inch.
Since the diameter of lug 20a is smaller than the one formed within and by bracket sections 14a, b, the former will be accommodated turnably therewithin; this will allow for some back and forth swinging movements of lug 20a, and, consequently of flap 20, yielding to smaller objects on the road. In order to prevent or stabilize any excess swinging movement of flap 20, the bifurcated portions 14a, b of bracket 14, are, respectively provided with a vertical downwardly extending section 14g (FIG. 2), constituting a narrow elongated passage, within which an upper part of flap 20 is disposed (when inserted in bracket parts 14a, b).
The conventional type mud flaps may also be used in conjunction with my invention. (FIG. 4).
The converging portions 14a, b of bracket means 14 are, as previously explained, mounted to the rear chassis of the vehicle. A tubular member 20b is provided from which mounting means, e.g., an apertured plate 20c extends, the former being insertable within converging sections 14a, b.
A conventional flap 20d is then mounted, e.g., by being bolted (bolts not shown) to plate 20c; one, thus may utilize existing mud flap types and incorporate them in the invented assembly, thereby avoiding the described drawbacks, inherent in the presently used mud guard attachments.
FIGS. 5 through 8 illustrate another embodiment of the invented mud guard assembly.
The mud guard 44 terminates in a quadilaterally shaped lug 44a and the interior space, formed by two open ended converging bracket portions 40 and 42 conforms spatially to the shape of lug 44a, that is to say, having a substantially quadilateral perimeter.
The bracket unit for flap 44 consist of one elongated apertured portion 40 and a counter portion 42, preferably divided into at least two separate sections bolted spatially apart onto the bracket portion 40 by means of bolts and nuts 40a, 42a, respectively, to form the complete bracket unit (FIGS. 5 and 6).
Each of the bracket portions 40, 42 defines identical configurations, that is to say, a vertical (apertured) upper part extending into an outwardly slanting shoulder and terminating in a downwardly converging part.
When bracket portions 40, 42 are assembled, they define a quadrilateral perimeter (FIGS. 7 and 8).
Flap 44 and lug 44a are inserted laterally into the space between bracket portions 40, 42 through one of the end openings thereof, and are preferably made in one integral piece of a rough surfaced rubber to increase the lug's 44a frictional resistance to be moved sidewise (once inserted within bracket portions 40, 42).
The lower edges of converging bracket portions 40, 42 define an elongated slot of about 1/8"-1/4" width, through which flap lug 44a may escape, as explained above in great detail.
At least one of the bracket portions, preferably sections 42 are made of heat treated resilient carbon steel, which will yield when a sufficient pull is exerted on flap 44.
The edges at the ends of bracket portions 40, 42 (as illustrated in FIG. 8) are flared, in order to facilitate the insertion of flap lug 44 into assembled bracket portions 40, 42.
Bracket portions 42 having identical dimensions, may be mounted interchangeably onto bracket portion 40.
The preferred average dimensions of bracket portion 40, 42 are as follows:
Length of bracket portion 40: 24"
Length of bracket portion 42: 10"
Width of shoulder: 1/2"-3/4"
Width of apertured part: 2"
Width of converging part: 11/2"
Bracket portions 40, 42 are bolted to the vehicle chassis by bolts spaced apart six inches.
While the foregoing has illustrated and described what is now contemplated to be the best mode of carrying out the invention, the latter is, of course, is subject to modifications without departing from the spirit and scope of the invention.
Therefore, it is not desired to restrict the invention to the particular constructions illustrated and described, but to cover all modifications, that may fall within the scope of the appended claims. | A mud guard assembly for mounting on the rear portion of a vehicle behind its rear wheels, respectively, comprising a bracket unit, fastened to the vehicle chassis, which bifurcates downwardly into resilient clamping legs, defining hollow space therewithin a horizontal slot extending between and along their entire lower edge portions: a mud flap, its upper end terminating in a lug for insertion in between the clamping legs of the bracket unit. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to a toilet flushing mechanism that allows a user to chose between a partial flush and a full flush. In particular, the present invention relates to a dual flushing assembly having two concentric handles operable to either partially or fully flush a toilet.
BACKGROUND OF THE INVENTION
[0002] Water conservation is becoming increasing more important. A significant source of water consumption is the water used in flushing toilets. As is well known in the art, several problems and difficulties are encountered in providing suitable means for flushing controlled amounts of water from a toilet water tank.
[0003] One of the most common flushing apparatuses in use today utilizes a ball cock supply valve that controls the inlet of water into the toilet tank. A buoyant float ball is connected to the ball cock by means of a trip lever and as the toilet tank is filled with water, the buoyant ball rises. The upward motion of the buoyant ball is transmitted to the ball cock supply valve through the trip lever until, at a predetermined water level, the ball cock shuts off the water inlet to the toilet tank. In most toilets, the water level in the tank may be adjusted by means of a screw-set mechanism located in the ball cock supply valve. Once the water level in the tank is set, further adjustment is not required and a consistent volume of water will be discharged each time the toilet is flushed.
[0004] In addition to the ball cock supply valve, a second valve means is needed for controlling the flushing of the toilet, namely a flush valve. Typically the flush valve comprises a flapper that seals water into the toilet tank. When the trip lever or handle on the outside of the toilet tank is depressed to initiates the flush of the toilet, the trip lever activities a trip arm to lift the flapper and allow water to exit the tank into the toilet bowl for the flush cycle.
[0005] Finally, a tank refill tube is commonly integrated with the water supply valve and the flush valve to ensure that the toilet trapway refills with water after the flush is completed.
[0006] A flush valve mechanism for controlling the flushing action of water through the water outlet of a toilet tank is taught in U.S. Pat. No. 4,305,163. The valve taught in U.S. Pat. No. 4,305,163 is a dual activity flush valve having a float assist, the operation of which permits the complete drainage of the water in the tank for a full flush. The flush valve operates by means of a pair of lever arms whereby one arm operates to lift up a vertical tube for limited flushing and the other arm operates to lift both the vertical tube and an ancillary float assist that extends the opening time of the valve until the entire water volume is depleted. Such a valve system is manufactured by Plasson Maagan Michael Industries Ltd. (“Plasson”).
[0007] The present invention provides a dual flushing assembly comprising dual handles for use with currently available components such as conventional ball cock supply valves and flushing valves as taught in U.S. Pat. No. 4,305,163 and manufactured by Plasson. Thus, when one wishes to flush only liquid waste, one of the dual handles will be responsible for a partial flush and when one wishes to flush both solid and liquid waste, a second handle will operate to effect a full flush.
SUMMARY OF THE INVENTION
[0008] The present invention has been accomplished to provide a double trip handle type flush control assembly, which operates to allow either a full volume of water to be drawn out of the toilet tank or a partial volume of water to be drawn out of the tank. In particular, the double trip handle type flush control assembly of the present invention is adaptable for use in any size toilet tank. Further, the flush control assembly of the present invention has been adapted to accommodate a refill tube, which directs water from the ball cock valve into an overflow tube to refill the toilet trapway after flushing.
[0009] The present invention provides a dual flushing apparatus, mountable through an aperture in a wall of a toilet tank, for use with a dual flushing valve assembly comprising a vertical tube having a first float means attached thereto and a float assist arm having a second float attached thereto, said flushing apparatus comprising:
[0010] a rotatable first handle means comprising a first handle and a first shaft having an annulus therethrough;
[0011] a rotatable second handle means comprising a second handle and a second shaft, said second shaft adapted to be slideably received in said annulus of said first shaft such that the second handle nests with the first handle;
[0012] a first flush lever arm have two ends, a first end operably attached to said first shaft and a second end operably attached to said float assist arm; and
[0013] a second flush lever arm having two ends, a first end operably attached to said second shaft and a second end operably attached to said vertical tube, said second end further having a bore therethrough and a nipple member in communication with said bore for attaching a refill tube such that when said second flush lever arm is operably attached to said vertical tube, said bore is directly over said vertical tube;
[0014] whereby said first flush lever arm supports said second flush lever arm such that when said second handle is depressed only said vertical tube is lifted for a partial flush but when said first handle is depressed both said vertical tube and said assist arm are lifted for a full flush.
[0015] In a preferred embodiment, the first flush lever and the second flush lever arm are adjustable in length so as to fit in any size toilet tank.
[0016] In another preferred embodiment, the first flush lever arm further comprises a first arm portion and a second arm portion, whereby each arm portions have male ends, and the second flush lever arm further comprises a first arm portion and a second arm portion, each arm portions having male ends. The male ends of the first and second arm portions of the first flush lever arm are interconnected by means of a first tube. The male ends of the first and second arm portions of said second flush lever arm are also interconnected by means of a second tube. The first and second tubes can be made in a variety of lengths, or can be of one length that can be cut to adapt to a particular size toilet tank.
[0017] In another preferred embodiment, the present invention provides a dual flushing apparatus comprising:
[0018] a rotatable first handle means comprising a first handle and a first shaft having an annulus therethrough;
[0019] a rotatable second handle means comprising a second handle and a second shaft, said second shaft adapted to be slideably received in said annulus of said first shaft such that the second handle nests with the first handle;
[0020] means for securing said second handle means to said first handle means;
[0021] a first flush lever arm operably attached to said first shaft, said first flush lever arm having a first arm portion and a second arm portion and each arm portion having an annulus therethrough;
[0022] a second flush lever arm operably attached to said second shaft, said second flush lever arm having a first arm portion and a second arm portion, each arm portion having an annulus therethrough;
[0023] a first rod member for insertion into said annulus of said first and second arm portions of said first flush lever arm to interconnect said first and second arm portions; and
[0024] a second rod member for insertion into said annulus of said first and second arm portions of said second flush lever arm to interconnect said first and second arm portions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] [0025]FIG. 1 shows the dual flushing apparatus of the present invention installed in a toilet tank.
[0026] [0026]FIG. 2 a is a perspective view of the dual flushing apparatus of the present invention.
[0027] [0027]FIG. 2 b is a side view of the dual flushing apparatus of the present invention.
[0028] [0028]FIG. 3 shows a perspective of the individual parts of the dual flushing apparatus and how they fit together.
[0029] [0029]FIG. 4 a is a perspective view of the dual flushing apparatus of the present invention showing the adjustable flush lever arms.
[0030] [0030]FIG. 4 b is a side view of the dual flushing apparatus of the present invention showing the adjustable flush lever arms.
DETAILED DESCRIPTION OF THE INVENTION
[0031] In FIG. 1, an embodiment of the dual flushing assembly 10 of the present invention has been installed through a mounting hole 12 in a wall 14 of a toilet tank 16 . In addition to the dual flushing assembly 10 , the toilet tank 16 comprises a ball cock valve assembly 18 , a dual acting flush valve assembly 22 and a refill tube 20 , wherein one end of refill tube 20 is attached to ball cock valve assembly 18 and the other end is attached to flush valve assembly 22 . The dual acting flush valve assembly 22 is preferably constructed of a thermoplastic material and manufactured by Plasson.
[0032] Dual acting flush valve assembly 22 is used in place of conventional flush valves such as a flapper valve or ball type valve because it has been designed to either partially or fully release water from the tank into the toilet bowl, as the need arises. Dual acting flush valve assembly 22 comprises a water outlet valve 24 and a buoyant valve engaging assembly which assembly comprises a float assist 28 attached to one end of a float assist arm 30 . Float assist arm 30 further comprises a ring 40 attached to the opposite end from float assist 28 . Float assist arm 30 operates to release float assist 28 .
[0033] Water outlet valve 24 comprises vertical tube 25 having a toilet mounting means 70 at one end for mounting said dual flush valve assembly 22 to water outlet 34 . Vertical tube 25 further comprises a flushing valve seal 100 , which seals the water outlet valve when water outlet valve is not in the lifted position. When vertical tube 25 of the water outlet valve 24 is lifted, flushing valve seal 100 is also lifted thereby releasing water through water outlet 34 into the toilet bowl (not shown).
[0034] Vertical tube 25 further comprises an aperture 38 at the opposite end and a partial float 26 . In operation, dual acting flush valve assembly 22 releases a full tank of water when both the float assist arm 30 and vertical tube 25 are simultaneously lifted. However, when vertical tube 25 is lifted alone, only a partial amount of water is released from the tank. Dual acting flush valve assembly 22 is described in more detail in U.S. Pat. No. 4,305,163, incorporated herein by reference.
[0035] To ensure that the toilet trapway is refilled after flushing, refill tube 20 , having first end 102 and second end 104 is provided. First end 102 is connected to ball cock valve assembly 18 , which supplies water to refill tube 20 . Second end 104 of refill tube 20 is posited directly over flush valve assembly 22 for supplying water through vertical tube 25 and water outlet 34 .
[0036] Dual flushing assembly 10 of the present invention has been adapted to be used with such dual acting flushing valve assemblies as shown in FIG. 1. One embodiment of dual flushing assembly 10 is illustrated in FIGS. 2 a and 2 b. FIG. 3 provides details of the interconnection of the various components of dual flushing assembly 10 . A rotatable first handle means 42 is provided, said first handle means 42 comprising a handle 72 (“first handle”) having a hollow shaft 76 (“first shaft”) at one end. End 78 of shaft 76 comprises a plurality of splines 80 arranged for mating with the correspondingly shaped hub 82 of first flush lever arm 46 . This ensures proper orientation of said first lever arm 46 relative to first handle means 42 .
[0037] A rotatable second handle means 44 , having a handle 84 (“second handle”) and a shaft 86 (“second shaft”), said shaft 86 located at one end of said handle 84 , is shown in FIGS. 2 a and 2 b with second shaft being inserted into first shaft such that second shaft is free to rotate concentrically within first shaft. Thus, second handle is resting on first handle to give the appearance of a single handle.
[0038] Shaft 86 further comprises a plurality of splines 88 at end 90 of shaft 86 , said splines 88 being discontinuous across the length of end 90 because of depressed ridge 92 , said ridge 92 being continuous around the circumference of shaft 86 . Splines 88 are arranged for mating with the correspondingly shaped hub 94 of second flush lever arm 48 .
[0039] [0039]FIGS. 2 a and 2 b show second handle means 44 nested within first handle means 42 . Retainer means 50 fittingly attaches to ridge 92 and is designed to ensure that first and second handle means remain nested. Retainer means 50 is shown in FIG. 3 as a simple clip, which clips over ridge 92 .
[0040] First flush lever arm 46 further comprises end 52 adapted to be mounted into ring 40 of float assist arm 30 as shown in FIG. 1. First flush lever arm 46 is bent such that it is positioned beneath second flush lever arm 48 . Second flush lever arm 48 further comprises end 54 adapted to penetrate aperture 38 of vertical tube 25 of water outlet valve 24 as shown in FIG. 1.
[0041] Second flush lever arm 48 further comprises a bore 98 therethrough and nipple 96 , said nipple adapted to snugly receive refill tube 20 as shown in FIG. 1. As previously mentioned, first end 102 of refill tube 20 is connected to ball cock valve assembly 18 and second end 104 of refill tube 20 is posited directly over the vertical tube 25 of dual acting flush valve assembly 22 for supplying water through vertical tube 25 and water outlet 34 . In the prior art, the refill tube had an elbow tube connected at its end, and said elbow tube simply hooked to the lip of the vertical tube of a dual acting flush valve assembly. However, such an attachment means of the refill tube to the vertical tube proved to be unsatisfactory as the refill tube was constantly being “knocked off” the lip of the vertical tube. As well, the movement of the vertical tube of the dual flush valve assembly, in response to the movement of the second flush lever arm is partially restricted due to the pull or drag of the elbow tube on the refill tube.
[0042] In the present invention, second end 104 of refill tube 20 snugly attaches on to nipple 96 located at end 54 of second flush lever arm 48 such when end 54 penetrates aperture 38 of vertical tube 25 , bore 98 and nipple 96 are located directly over the opening 106 of vertical tube 25 . Once bore 98 and nipple 96 are positioned directly over opening 106 , refill tube 20 can be fitted thereon to supply water through vertical tube 25 and through water outlet 34 in order to refill the toilet trapway (not shown) once flushing has occurred. Thus, by snugly fitting the refill tube 20 on second flush lever arm 48 , refill tube 20 will be less likely to be knocked off, and will always be positioned directly above the vertical tube. Further, by being positioned on the second flush lever arm 48 , there is no drag or pull on vertical tube 25 .
[0043] In a preferred embodiment first and second flush lever arms 46 and 48 are adjustable in length. Such adjustability is desirable due to the variety of different tank sizes and shapes on the market today. Adjustability is achieved in a preferred embodiment as follows.
[0044] With reference now to FIGS. 4 a and 4 b, first flush lever arm 46 is comprised of two separate sections 58 and 60 , each having male ends 66 and 67 , respectively. Tube 36 , which can be made in any length, or, in the alternative, can be cut to any length, snugly fits over male ends 66 , 67 of sections 58 and 60 , thereby connecting the two sections 58 and 60 to form a contiguous arm. Similarly, second flush lever arm 48 is comprised of two separate sections 62 and 64 , each having male ends 68 and 69 , respectively. Tube 56 , which again can be made in any length or cut to any length, snugly fits over male ends 68 , 69 of sections 62 and 64 to form a contiguous arm.
[0045] In an alternative embodiment (not shown), each arm section could have an annulus partially therethrough and a dowel could be inserted into each annulus to form a contiguous arm.
[0046] With reference again to FIG. 1, the dual flushing assembly of the present invention operates as follows. When the handle 84 of second handle means 44 is depressed, second flush lever arm 48 is lifted, which in turn lifts vertical tube 25 of water outlet valve 24 and flushing valve seal 100 thereby releasing water through water outlet 34 into toilet bowl (not shown). However, partial float 26 is positioned on vertical tube 25 such that the water outlet valve 24 will close water outlet 34 when only part of the water in the tank 14 is released. This results in only a partial flush. In a preferred embodiment, partial float 26 can be adjustable along the length of vertical tube 25 to control the amount of water released during partial flushing.
[0047] When handle 72 of first handle means 42 is depressed, first flush lever arm 46 is lifted, which in turn lifts both second flush lever arm 48 and float assist arm 30 . Second flush lever arm 48 in turn lifts vertical tube 25 as described above. Float assist arm 30 in turn releases float assist 28 . When float assist 28 is released, it operates to keep the vertical tube 25 in the lifted position for a longer period of time. Hence, water outlet valve 24 will remain in the lifted position longer thereby allowing all of the water in the tank 14 to be released through water outlet 34 into toilet bowl (not shown). This results in a full flush.
[0048] While various embodiments in accordance with the present invention have been shown and described, it is understood that the same is not limited thereto, but is susceptible to numerous changes and modifications as known to those skilled in the art, and therefore the present invention is not to be limited to the details shown and described herein, but is intended to cover all such changes and modifications as are encompassed by the scope of the appended claims. | The present invention relates to a double trip handle type flush control assembly, which operates to allow either a full volume of water to be drawn out of the toilet tank or a partial volume of water to be drawn out of the tank. In particular, the double trip handle type flush control assembly of the present invention is adaptable for use in any size toilet tank. Further, the flush control assembly of the present invention has been adapted to accommodate a refill tube, which directs water from a ball cock valve into an overflow tube to refill the toilet trapway after flushing. | 4 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of, and claims priority to, U.S. application Ser. No. 09/641,327, filed Aug. 18, 2000.
FIELD OF THE INVENTION
The present invention relates to treating disease states characterized by abnormal cell mitosis and or abnormal angiogenesis. More particularly, the present invention relates to certain analogs of 2-methoxyestradiol (2ME2) and their effect on diseases characterized by abnormal cell mitosis and/or abnormal angiogenesis.
BACKGROUND OF THE INVENTION
As used herein, the term “angiogenesis” means the generation of new blood vessels into a tissue or organ. Under normal physiological conditions, humans or animals only undergo angiogenesis in very specific restricted situations. For example, angiogenesis is normally observed in wound healing, fetal and embryonal development and formation of the corpus luteum, endometrium and placenta. The control of angiogenesis is a highly regulated system of angiogenic stimulators and inhibitors. The control of angiogenesis has been found to be altered in certain disease states and, in many cases, the pathological damage associated with the disease is related to the uncontrolled angiogenesis.
Both controlled and uncontrolled angiogenesis are thought to proceed in a similar manner. Endothelial cells and pericytes, surrounded by a basement membrane, form capillary blood vessels. Angiogenesis begins with the erosion of the basement membrane by enzymes released by endothelial cells and leukocytes. The endothelial cells, which line the lumen of blood vessels, then protrude through the basement membrane. Angiogenic stimulants induce the endothelial cells to migrate through the eroded basement membrane. The migrating cells form a “sprout” off the parent blood vessel, where the endothelial cells undergo mitosis and proliferate. The endothelial sprouts merge with each other to form capillary loops, creating the new blood vessel. In the disease state, prevention of angiogenesis could avert the damage caused by the invasion of the new microvascular system.
Persistent, unregulated angiogenesis occurs in a multiplicity of disease states, tumor metastasis and abnormal growth by endothelial cells and supports the pathological damage seen in these conditions. The diverse pathological states created due to unregulated angiogenesis have been grouped together as angiogenic dependent or angiogenic associated diseases. Therapies directed at control of the angiogenic processes could lead to the abrogation or mitigation of these diseases.
One example of a disease mediated by angiogenesis is ocular neovascular disease. This disease is characterized by invasion of new blood vessels into the structures of the eye such as the retina or cornea. It is the most common cause of blindness and is involved in approximately twenty eye diseases. In age-related macular degeneration, the associated visual problems are caused by an ingrowth of chorioidal capillaries through defects in Bruch's membrane with proliferation of fibrovascular tissue beneath the retinal pigment epithelium. Angiogenic damage is also associated with diabetic retinopathy, retinopathy of prematurity, corneal graft rejection, neovascular glaucoma and retrolental fibroplasia. Other diseases associated with corneal neovascularization include, but are not limited to, epidemic keratoconjunctivitis, Vitamin A deficiency, contact lens overwear, atopic keratitis, superior limbic keratitis, pterygium keratitis sicca, sjogrens, acne rosacea, phylectenulosis, syphilis, Mycobacteria infections, lipid degeneration, chemical burns, bacterial ulcers, fungal ulcers, Herpes simplex infections, Herpes zoster infections, protozoan infections, Kaposi sarcoma, Mooren ulcer, Terrien's marginal degeneration, mariginal keratolysis, rheumatoid arthritis, systemic lupus, polyarteritis, trauma, Wegeners sarcoidosis, Scleritis, Steven's Johnson disease, periphigoid radial keratotomy, and corneal graph rejection.
Diseases associated with retinal/choroidal neovascularization include, but are not limited to, diabetic retinopathy, macular degeneration, sickle cell anemia, sarcoid, syphilis, pseudoxanthoma elasticum, Pagets disease, vein occlusion, artery occlusion, carotid obstructive disease, chronic uveitis/vitritis, mycobacterial infections, Lyme's disease, systemic lupus erythematosis, retinopathy of prematurity, Eales disease, Bechets disease, infections causing a retinitis or choroiditis, presumed ocular histoplasmosis, Bests disease, myopia, optic pits, Stargarts disease, pars planitis, chronic retinal detachment, hyperviscosity syndromes, toxoplasmosis, trauma and post-laser complications. Other diseases include, but are not limited to, diseases associated with rubeosis (neovasculariation of the angle) and diseases caused by the abnormal proliferation of fibrovascular or fibrous tissue including all forms of proliferative vitreoretinopathy.
Another disease in which angiogenesis is believed to be involved is rheumatoid arthritis. The blood vessels in the synovial lining of the joints undergo angiogenesis. In addition to forming new vascular networks, the endothelial cells release factors and reactive oxygen species that lead to pannus growth and cartilage destruction. The factors involved in angiogenesis may actively contribute to, and help maintain, the chronically inflamed state of rheumatoid arthritis.
Factors associated with angiogenesis may also have a role in osteoarthritis. The activation of the chondrocytes by angiogenic-related factors contributes to the destruction of the joint. At a later stage, the angiogenic factors would promote new bone formation. Therapeutic intervention that prevents the bone destruction could halt the progress of the disease and provide relief for persons suffering with arthritis.
Chronic inflammation may also involve pathological angiogenesis. Such disease states as ulcerative colitis and Crohn's disease show histological changes with the ingrowth of new blood vessels into the inflamed tissues. Bartonellosis, a bacterial infection found in South America, can result in a chronic stage that is characterized by proliferation of vascular endothelial cells. Another pathological role associated with angiogenesis is found in atherosclerosis. The plaques formed within the lumen of blood vessels have been shown to have angiogenic stimulatory activity.
One of the most frequent angiogenic diseases of childhood is the hemangioma. In most cases, the tumors are benign and regress without intervention. In more severe cases, the tumors progress to large cavernous and infiltrative forms and create clinical complications. Systemic forms of hemangiomas, the hemangiomatoses, have a high mortality rate. Therapy-resistant hemangiomas exist that cannot be treated with therapeutics currently in use.
Angiogenesis is also responsible for damage found in hereditary diseases such as Osler-Weber-Rendu disease, or hereditary hemorrhagic telangiectasia. This is an inherited disease characterized by multiple small angiomas, tumors of blood or lymph vessels. The angiomas are found in the skin and mucous membranes, often accompanied by epistaxis (nosebleeds) or gastrointestinal bleeding and sometimes with pulmonary or hepatic arteriovenous fistula.
Angiogenesis is prominent in solid tumor formation and metastasis. Angiogenic factors have been found associated with several solid tumors such as rhabdomyosarcomas, retinoblastoma, Ewing sarcoma, neuroblastoma, and osteosarcoma. A tumor cannot expand without a blood supply to provide nutrients and remove cellular wastes. Tumors in which angiogenesis is important include solid tumors, and benign tumors such as acoustic neuroma, neurofibroma, trachoma and pyogenic granulomas. Prevention of angiogenesis could halt the growth of these tumors and the resultant damage to the animal due to the presence of the tumor.
It should be noted that angiogenesis has been associated with blood-born tumors such as leukemias, any of various acute or chronic neoplastic diseases of the bone marrow in which unrestrained proliferation of white blood cells occurs, usually accompanied by anemia, impaired blood clotting, and enlargement of the lymph nodes, liver, and spleen. It is believed that angiogenesis plays a role in the abnormalities in the bone marrow that give rise to leukemia-like tumors.
Angiogenesis is important in two stages of tumor metastasis. The first stage where angiogenesis stimulation is important is in the vascularization of the tumor which allows tumor cells to enter the blood stream and to circulate throughout the body. After the tumor cells have left the primary site, and have settled into the secondary, metastasis site, angiogenesis must occur before the new tumor can grow and expand. Therefore, prevention of angiogenesis could lead to the prevention of metastasis of tumors and possibly contain the neoplastic growth at the primary site.
Knowledge of the role of angiogenesis in the maintenance and metastasis of tumors has led to a prognostic indicator for breast cancer. The amount of neovascularization found in the primary tumor was determined by counting the microvessel density in the area of the most intense neovascularization in invasive breast carcinoma. A high level of microvessel density was found to correlate with tumor recurrence. Control of angiogenesis by therapeutic means could possibly lead to cessation of the recurrence of the tumors.
Angiogenesis is also involved in normal physiological processes such as reproduction and wound healing. Angiogenesis is an important step in ovulation and also in implantation of the blastula after fertilization. Prevention of angiogenesis could be used to induce amenorrhea, to block ovulation or to prevent implantation by the blastula.
In wound healing, excessive repair or fibroplasia can be a detrimental side effect of surgical procedures and may be caused or exacerbated by angiogenesis. Adhesions are a frequent complication of surgery and lead to problems such as small bowel obstruction.
Several kinds of compounds have been used to prevent angiogenesis. Taylor et al. have used protamine to inhibit angiogenesis, see Taylor et al., Nature 297:307 (1982). The toxicity of protamine limits its practical use as a therapeutic. Folkman et al. have disclosed the use of heparin and steroids to control angiogenesis. See Folkman et al., Science 221:719 (1983) and U.S. Pat. Nos. 5,001,116 and 4,994,443. Steroids, such as tetrahydrocortisol, which lack gluco and mineral corticoid activity, have been found to be angiogenic inhibitors.
Other factors found endogenously in animals, such as a 4 kDa glycoprotein from bovine vitreous humor and a cartilage derived factor, have been used to inhibit angiogenesis. Cellular factors such as interferon inhibit angiogenesis. For example, interferon α or human interferon β has been shown to inhibit tumor-induced angiogenesis in mouse dermis stimulated by human neoplastic cells. Interferon β is also a potent inhibitor of angiogenesis induced by allogeneic spleen cells. See Sidky et al., Cancer Research 47:5155-5161 (1987). Human recombinant α interferon (alpha/A) was reported to be successfully used in the treatment of pulmonary hemangiomatosis, an angiogenesis-induced disease. See White et al., New England J. Med. 320:1197-1200 (1989).
Other agents which have been used to inhibit angiogenesis include ascorbic acid ethers and related compounds. See Japanese Kokai Tokkyo Koho No. 58-131978. Sulfated polysaccharide DS 4152 also shows angiogenic inhibition. See Japanese Kokai Tokkyo Koho No. 63-119500. A fungal product, fumagillin, is a potent angiostatic agent in vitro. The compound is toxic in vivo, but a synthetic derivative, AGM 12470, has been used in vivo to treat collagen II arthritis. Fumagillin and O-substituted fumagillin derivatives are disclosed in EPO Publication Nos. 0325199A2 and 0357061A1. Folkman et al., described several proteins derived from endogenous proteins including angiostatin and endostatin. (See, for example, U.S. Pat. Nos. 6,024,688 and U.S. Pat. No. 5,854,205 which are incorporated in their entirety) D'Amato et al., described 2-methoxyestradiol and derivatives of 2-methoxyestradiol in U.S. Pat. Nos. 5,504,074 and 5,661,143 which are incorporated herein by reference entirety.
The above compounds are either topical or injectable therapeutics. Therefore, there are drawbacks to their use as a general angiogenic inhibitor and lack adequate potency. For example, in prevention of excessive wound healing, surgery on internal body organs involves incisions in various structures contained within the body cavities. These wounds are not accessible to local applications of angiogenic inhibitors. Local delivery systems also involve frequent dressings which are impracticable for internal wounds, and increase the risk of infection or damage to delicate granulation tissue for surface wounds.
Thus, a method and composition are needed that are capable of inhibiting angiogenesis and which are easily administered. A simple and efficacious method of treatment would be through the oral route. If an angiogenic inhibitor could be given by an oral route, the many kinds of diseases discussed above, and other angiogenic dependent pathologies, could be treated easily. The optimal dosage could be distributed in a form that the patient could self-administer.
Other diseases are also characterized by an abnormal balance between cellular mitosis and apoptosis. One of these diseases is osteoporosis. Osteoporosis is characterized by a reduction in the bone mass of the skeleton which leads to skeletal fragility and an increased risk of fracture. In humans, the most common sites of fracture are found in the forearm, the vertebrae and the hip bones. Osteoporosis and its attendant fractures are a major cause of morbidity and mortality and lead to increased health costs for care.
In treating osteoporosis the main objective is to prevent fractures by stopping the loss of skeletal integrity. A variety of different therapies have been tried to achieve this objective, such as calcium, Vitamin D supplements and hormone replacement. Calcitonin has been used to improve bone mineral density at all bone sites. Bisphosphonates are an important group of therapeutic agents used for treatment of osteoporosis. They act by inhibiting bone resorption and increase bone density. Cyclical etidronate treatment aids in decreasing vertebral fractures, as does hormone replacement therapy and calcitonin. Alendronate has been shown to decrease the risk of symptomatic fractures of the forearm, spine and hip.
None of these treatments have proven to be effective in large numbers of osteoporotic patients. Additionally, the currently used therapies have unwanted side effects that create compliance and tolerance problems in treatment regimens. The most common adverse events with cyclical etidronate and alendronate are gastrointestinal disturbances. Esophagitis has also been a complication of therapies with alendronate. Cyclical etidronate has been shown to lead to focal osteomalacia. Hormone replacement therapies lead to estrogen effects such as uterine hypertrophy, and a potential for stimulation of estrogen-sensitive tumors leading to complications such as breast cancer.
What is needed are safe and effective treatments that do not create unwanted side effects.
2-Methoxyestradiol is an endogenous metabolite of estradiol (E2) that has potent anti-proliferative activity and induces apoptosis in a wide variety of tumor and non-tumor cell lines. When administered orally, it exhibits anti-tumor and anti-proliferative activity with little or no toxicity. In vitro data suggests that 2-methoxyestradiol does not engage the estrogen receptor for its anti-proliferative activity and is not estrogenic over a wide range of concentrations, as accessed by estrogen dependant MCF-7 cell proliferation. However, the presence of demethylases in vivo may metabolize this compound to 2-hydroxyestradiol, which has been shown to be estrogenic by several approaches. What is needed is a means to improve the bioavailibility of estradiol or 2-methoxyestradiol and to reduce the formation of estrogenic 2-methoxyestradiol metabolities. What is also needed is a means to modify estradiol or 2-methoxyestradiol in such a way that the molecule can not be converted into an uterotropic derivative.
SUMMARY OF THE INVENTION
The present invention provides certain analogs of 2-methoxyestradiol that are effective in treating diseases characterized by abnormal mitosis and/or abnormal angiogenesis. Specifically the present invention relates to analogs of 2-methoxyestradiol that have been modified at the 2 position and the 16 position. Compounds within the general formulae that inhibit cell proliferation are preferred. Preferred compositions may also exhibit a change (increase or decrease) in estrogen receptor binding, improved absorption, transport (e.g. through blood-brain barrier and cellular membranes), biological stability, or decreased toxicity. The invention also provides compounds useful in the method, as described by the general formulae of the claims.
A mammalian disease characterized by undesirable cell mitosis, as defined herein, includes but is not limited to excessive or abnormal stimulation of endothelial cells (e.g., atherosclerosis), solid tumors and tumor metastasis, benign tumors, for example, hemangiomas, acoustic neuromas, neurofibromas, trachomas, and pyogenic granulomas, vascular malfunctions, abnormal wound healing, inflammatory and immune disorders, Bechet's disease, gout or gouty arthritis, abnormal angiogenesis accompanying: rheumatoid arthritis, psoriasis, diabetic retinopathy, and other ocular angiogenic diseases such as retinopathy of prematurity (retrolental fibroplasic), macular degeneration, corneal graft rejection, neovascular glaucoma and Osler Weber syndrome. Other undesired angiogenesis involves normal processes including ovulation and implantation of a blastula. Accordingly, the compositions described above can be used to block ovulation and implantation of a blastula or to block menstruation (induce amenorrhea).
Since 2-methoxyestradiol is metabolized to a much less active metabolite, the present invention adds steric bulk and/or modification of electrostatic characteristics at position 16 of 2-methoxyestradiol for retarding or preventing interaction of 17β-hydroxysteroid dehydrogenases and co-factor NADP + on this substrate. Addition of steric bulk and/or modification of electrostatic characteristics at position 16 of 2-methoxyestradiol may retard or prevent glucuronidation. It is believed that retardation or prevention of these two metabolic deactivation pathways prolongs the serum lifetime of 2-methoxyestradiol and other estrogenic compounds while retaining the desired anti-angiogenic and anti-tumor activity.
Aside from preventing the possible metabolism of 2ME2 to 2ME1, which may occur by making these steroids poor substrates for 17B-HSD (by either steric and/or electronic effects), it is not possible for these analogs to undergo the demethylation known to occur with 2ME2 since there is no methyl ether group at that position. This is desirable since it has been demonstrated that 2-hydroxyestradiol (the product of demethylation of 2ME2) has estrogenic activity.
Also disclosed is a method for modifying the methyl ether of 2-methoxyestradiol so that it can not be a substrate for demethylase and the resulting compounds.
Other features and advantages of the invention will be apparent from the following description of preferred embodiments thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts: I. colchicine, 2-methoxyestradiol and combretastatin A-4, and II. various estradiol derivatives comprising colchicine (a-c) or combretastatin A-4 (d) structural motifs as described below.
DETAILED DESCRIPTION OF THE INVENTION
As described below, compounds that are useful in accordance with the invention include novel estradiol derivatives that exhibit anti-mitotic, anti-angiogenic and anti-tumor properties. Specific compounds according to the invention are described below. Preferred compounds of the invention are estradiol derivatives modified at either the 2 or 16 positions. Those skilled in the art will appreciate that the invention extends to other compounds within the formulae given in the claims below, having the described characteristics. These characteristics can be determined for each test compound using the assays detailed below and elsewhere in the literature.
Without wishing to be bound to specific mechanisms or theory, it appears that certain compounds that are known to exhibit anti-mitotic properties such as colchicine and combretastatin A-4 share certain structural similarities with estradiol. FIG. 1 illustrates the molecular formulae of estradiol, colchicine, combretastatin A-4, and improved estradiol derivatives that exhibit anti-mitotic, anti-angiogenic and anti-tumor properties. Molecular formulae are drawn and oriented to emphasize structural similarities between the ring structures of colchicine, combretastatin A-4, estradiol, and certain estradiol derivatives. Estradiol derivatives are made by incorporating colchicine or combretastatin A-4 structural motifs into the steroidal backbone of estradiol.
FIG. 1 , part I, depicts the chemical formulae of colchicine, 2-methoxyestradiol and combretastatin A-4. FIG. 1 , part II a-d, illustrates estradiol derivatives that comprise structural motifs found in colchicine or combretastatin A-4. For example, part II a-c shows estradiol derivatives with an A and/or B ring expanded from six to seven carbons as found in colchicine and part IId depicts an estradiol derivative with a partial B ring as found in combretastatin A-4. Each C ring of an estradiol derivative, including those shown in FIG. 1 , may be fully saturated as found in 2-methoxyestradiol. R 1-6 represent a subset of the substitution groups found in the claims. Each R 1 -R 6 can independently be defined as —R 1 , OR 1 , —OCOR 11 —SR 1 , —F, —NHR 2 , —Br, —I, or —C≡CH.
2-Methoxyestradiol is an endogenous metabolite of estradiol that has potent anti-proliferative activity and induces apoptosis in a wide variety of tumor and non-tumor cell lines. When administered orally, it exhibits anti-tumor and anti-proliferative activity with little or no toxicity. 2-Methoxyestradiol is metabolized to a much less active metabolite, 2-methoxyestrone as indicated by in vitro and in vivo results. Although not wishing to be bound by theory, it is believed that this metabolite is formed through the same enzymatic pathway as estrone is formed from estradiol. Although not wishing to be bound by theory, it is believed that the enzymes responsible for this reversible reaction on estradiol are the 17β-hydroxysteroid dehydrogenases (17β-HSD) and NADP+ co-factor (Han et al., J. Biol. Chem. 275:2, 1105-1111 (Jan. 12, 2000) and other references cited earlier). Each of the four members of this enzyme family, types 1, 2, 3, and 4, have distinct activity. It appears that 17β-HSD type 1 catalyzes the reductive reaction (estrone to estradiol), while 17β-HSD type 2 catalyzes the oxidation reaction (estradiol to estrone), and type 3 catalyzes 4-androstenedione to testosterone. An additional metabolic deactivation pathway results in glucuronidation of 2-methoxyestradiol.
Since 2-methoxyestradiol is metabolized to a much less active metabolite, the present invention adds steric bulk and/or modification of electrostatic characteristics at position 16 of 2-methoxyestradiol for retarding or preventing interaction of the family of 17β-hydroxysteroid dehydrogenases and co-factor NADP + on this substrate. Addition of steric bulk and/or modification of electrostatic characteristics at position 16 of 2-methoxyestradiol also retards or prevents glucuronidation. It is believed that retardation or prevention of these two metabolic deactivation pathways prolongs the serum lifetime of 2-methoxyestradiol and other estradiol derivatives while retaining the desired anti-angiogenic and anti-tumor activity.
Aside from preventing the possible metabolism of 2ME2 to 2ME1, which may occur by making these steroids poor substrates for 17B-HSD (by either steric and/or electronic effects), it is not possible for these analogs to undergo the demethylation known to occur with 2ME2 since there is no methyl ether group at that position. This is desirable since it has been demonstrated that 2-hydroxyestradiol (the product of demethylation of 2ME2) has estrogenic activity.
In another embodiment of the invention, estradiol derivatives are modified at the 2 position.
Anti-Proliferative Activity In Situ
Anti-proliferative activity is evaluated in situ by testing the ability of an improved estradiol derivative to inhibit the proliferation of new blood vessel cells (angiogenesis). A suitable assay is the chick embryo chorioallantoic membrane (CAM) assay described by Crum et al. Science 230:1375 (1985). See also, U.S. Pat. No. 5,001,116, hereby incorporated by reference, which describes the CAM assay. Briefly, fertilized chick embryos are removed from their shell on day 3 or 4, and a methylcellulose disc containing the drug is implanted on the chorioallantoic membrane. The embryos are examined 48 hours later and, if a clear avascular zone appears around the methylcellulose disc, the diameter of that zone is measured. Using this assay, a 100 mg disk of the estradiol derivative 2-methoxyestradiol was found to inhibit cell mitosis and the growth of new blood vessels after 48 hours. This result indicates that the anti-mitotic action of 2-methoxyestradiol can inhibit cell mitosis and angiogenesis.
Anti-Proliferative Activity In Vitro
The process by which 2ME 2 affects cell growth remains unclear, however, a number of studies have implicated various mechanisms of action and cellular targets. 2ME 2 induced changes in the levels and activities of various proteins involved in the progression of the cell cycle. These include cofactors of DNA replication and repair, e.g., proliferating cell nuclear antigen (PCNA) (Klauber, N., Parangi, S., Flynn, E., Hamel, E. and D'Amato, R. J. (1997), Inhibition of angiogenesis and breast cancer in mice by the microtubule inhibitors 2-methoxyestradiol and Taxol., Cancer Research 57, 81-86; Lottering, M-L., de Kock, M., Viljoen, T. C., Grobler, C. J. S. and Seegers, J. C. (1996) 17β-estradiol metabolites affect some regulators of the MCF-7 cell cycle. Cancer Letters 110, 181-186); cell division cycle kinases and regulators, e.g., p34 cdc2 and cyclin B (Lottering et al. (1996); Attalla, H., Mäkelä, T. P., Adlercreutz, H. and Andersson, L. C. (1996) 2-methoxyestradiol arrests cells in mitosis without depolymerizing tubulin. Biochemical and Biophysical Research Communications 228, 467-473; Zoubine, M. N., Weston, A. P., Johnson, D. C., Campbell, D. R. and Banjee, S. K. (1999) 2-Methoxyestradiol-induced growth suppression and lethality in estrogen-responsive MCF-7 cells may be mediated by down regulation of p34cdc2 and cyclin B1 expression. Int J Oncol 15, 639-646); transcription factor modulators, e.g., SAPK/JNK (Yue, T-L., Wang, X., Louden, C. S., Gupta, L. S., Pillarisetti, K., Gu, J-L., Hart, T. K., Lysko, P. G. and Feuerstein, G. Z. (1997) 2-methoxyestradiol, an endogenous estrogen metabolite induces apoptosis in endothelial cells and inhibits angiogenesis: Possible role for stress-activated protein kinase signaling pathway and fas expression. Molecular Pharmacology 51, 951-962; Attalla, H., Westberg, J. A., Andersson, L. C., Aldercreutz, H. and Makela, T. P. (1998) 2-Methoxyestradiol-induced phosphorylation of bcl-2: uncoupling from JNK/SAPK activation. Biochem and Biophys Res Commun 247, 616-619); and regulators of cell arrest and apoptosis, e.g., tubulin (D'Amato, R. J., Lin, C. M., Flynn, E., Folkman, J. and Hamel, E. (1994) 2-Methoxyestradiol, and endogenous mammalian metabolite, inhibits tubulin polymerization by interacting at the colchicine site. Proc. Natl. Acad. Sci. USA 91, 3964-3968; Hamel, E., Lin, C. M., Flynn, E. and D'Amato, R. J. (1996) Interactions of 2-methoxyestradiol, and endogenous mammalian metabolite, with unploymerized tubulin and with tubulin polymers. Biochemistry 35, 1304-1310), p21 WAF1/CIP1 (Mukhopadhyay, T. and Roth, J. A. (1997) Induction of apoptosis in human lung cancer cells after wild-type p53 activation by methoxyestradiol. Oncogene 14, 379-384), bcl-2 and FAS (Yue et al. (1997); Attalla et al. (1998)), and p53 (Kataoka, M., Schumacher, G., Cristiano, R. J., Atkinson, E. N., Roth, J. A. and Mukhopadhyay, T. (1998) An agent that increases tumor suppressor transgene product coupled with systemic transgene delivery inhibits growth of metastatic lung cancer in vivo. Cancer Res 58, 4761-4765; Mukhopadhyay et al. (1997); Seegers, J. C., Lottering, M-L., Grobler C. J. S., van Papendorp, D. H., Habbersett, R. C., Shou, Y. and Lehnert B. E. (1997) The mammalian metabolite, 2-methoxyestradiol, affects p53 levels and apoptosis induction in transformed cells but not in normal cells. J. Steroid Biochem. Molec. Biol. 62, 253-267). The effects on the level of cAMP, calmodulin activity and protein phosphorylation may also be related to each other. More recently, 2ME2 was shown to upregulate Death Receptor 5 and caspase 8 in human endothelial and tumor cell lines (LaVallee, T. M., Hembrough, W. A., Williams, M. S., Zhan, X. H., Pribluda, V. S., Papathanassiu, A., and Green, S. J. 2-Methoxyestradiol upregulates DR5 and induces apoptosis independently of p53. (Submitted for publication)). All cellular targets described above are not necessarily mutually exclusive to the inhibitory effects of 2ME 2 in actively dividing cells.
The high affinity binding to SHBG has been mechanistically associated to its efficacy in a canine model of prostate cancer, in which signaling by estradiol and 5α-androstan-3α,17β-diol were inhibited by 2ME 2 (Ding, V. D., Moller, D. E., Feeney, W. P., Didolkar, V., Nakhla, A. M., Rhodes, L., Rosner, W. and Smith, R. G. (1998) Sex hormone-binding globulin mediates prostate androgen receptor action via a novel signaling pathway. Endocrinology 139, 213-218).
The more relevant mechanism described above have been extensively discussed in Victor S. Pribluda, Theresa M. LaVallee and Shawn J. Green, 2-methoxyestradiol: a novel endogenotis chemotherapeutic and antiangiogenic in The New Angiotherapy, Tai-Ping Fan and Robert Auerbach eds., Human Press Publisher.
Assays relevant to the mechanisms of action and activity are well-known in the art. For example, anti-mitotic activity mediated by effects on tubulin polymerization activity can be evaluated by testing the ability of an estradiol derivative to inhibit tubulin polymerization and microtubule assembly in vitro. Microtubule assembly is followed in a Gilford recording spectrophotometer (model 250 or 2400S) equipped with electronic temperature controllers. A reaction mixture (all concentrations refer to a final reaction volume of 0.25 μl) contains 1.0M monosodium glutamate (pH 6.6), 1.omg/ml (10 μM) tubulin, 1.0 mM MgCl 2 , 4% (v/v) dimethylsulfoxide and 20-75 μM of a composition to be tested. The 0.24 ml reaction mixtures are incubated for 15 min. at 37° C. and then chilled on ice. After addition of 10 μl 2.5 mM GTP, the reaction mixture is transferred to a cuvette at 0° C., and a baseline established. At time zero, the temperature controller of the spectrophotometer is set at 37° C. Microtubule assembly is evaluated by increased turbity at 350 nm. Alternatively, inhibition of microtubule assembly can be followed by transmission electron microscopy as described in Example 2 below.
Other such assays include counting of cells in tissue culture plates or assessment of cell number through metabolic assays or incorporation into DNA of labeled ( 3 H-thymidine) or immuno-reactive (BrdU) nucleotides. In addition, antiangiogenic activity may be evaluated through endothelial cell migration, endothelial cell tubule formation, or vessel outgrowth in ex-vivo models such as rat aortic rings.
Indications
The invention can be used to treat any disease characterized by abnormal cell mitosis. Such diseases include, but are not limited to: abnormal stimulation of endothelial cells (e.g., atherosclerosis), solid tumors and tumor metastasis, benign tumors, for example, hemangiomas, acoustic neuromas, neurofribomas, trachomas, and pyogenic granulomas, vascular malfunctions, abnormal wound healing, inflammatory and immune disorders, Bechet's disease, gout or gouty arthritis, abnormal angiogenesis accompanying: rheumatoid arthritis, psoriasis, diabetic retinopathy, and other ocular angiogenic diseases such as retinopathy of prematurity (retrolental fibroplasic), macular degeneration, corneal graft rejection, neuroscular glacoma and Oster Webber syndrome.
In addition, the invention can be used to treat a variety of post-menapausal symptoms, including osteoporosis, cardiovascular disease, Alzheimer's disease, to reduce the incidence of strokes, and as an alternative to prior estrogen replacement therapies. The compounds of the present invention can work by estrogenic and non-estrogenic biochemical pathways.
Improved Estradiol Derivative Synthesis
Known compounds that are used in accordance with the invention and precursors to novel compounds according to the invention can be purchased, e.g., from Sigma Chemical Co., St. Louis, Steraloids and Research Plus. Other compounds according to the invention can be synthesized according to known methods from publicly available precursors.
The chemical synthesis of estradiol has been described (Eder, V. et al., Ber 109, 2948 (1976); Oppolzer, D. A. and Roberts, D. A. Helv. Chim. Acta. 63, 1703, (1980)). Synthetic methods for making seven-membered rings in multi-cyclic compounds are known (Nakamuru, T. et al. Chem. Pharm. Bull. 10, 281 (1962); Sunagawa, G. et al. Chem. Pharm. Bull. 9, 81 (1961); Van Tamelen, E. E. et al. Tetrahedren 14, 8-34 (1961); Evans, D. E. et al. JACS 103, 5813 (1981)). Those skilled in the art will appreciate that the chemical synthesis of estradiol can be modified to include 7-membered rings by making appropriate changes to the starting materials, so that ring closure yields seven-membered rings. Estradiol or estradiol derivatives can be modified to include appropriate chemical side groups according to the invention by known chemical methods ( The Merck Index, 11th Ed., Merck & Co., Inc., Rahway, N.J. USA (1989), pp. 583-584).
Analogs of 2ME2 or 2-ethoxyestradiol containing 7 membered rings can be modified to include appropriate chemical side groups according to the invention by known chemical methods (see for example, Miller, T. A.; Bulman, A. L.; Thompson, C. D.; Garst, M. E.; Macdonald, T. L. “Synthesis and Structure-Activity Profiles of A-Homoestranes, the Estratropones.” J. Med. Chem., 1997, 40, 3836-3841; Miller, T. A.; Bulman, A. L.; Thompson, C. D.; Garst, M. E.; Macdonald, T. L. “The Synthesis and Evaluation of Functionalized Estratropones-Potent Inhibitors of Tubulin Polymerization.” Bioorg. Med. Chem. Letters, 1997, 7, 1851-1856; and Wang, Z.; Yang, D.; Mohanakrishnan, A. K.; Fanwick, P. E.; Nampoothiri, P.; Hamel, E.; Cushman, M. “Synthesis of B-Ring Homologated Estradiol Analogs that Modulate Tubulin Polymerization and Microtubule Stability.” J. Med. Chem., 2000, 43, 2419-2429. These articles do not utilize ring closure strategies to make the seven membered ring, rather they use a ring expansion strategy. The Cushman article explores B-Ring expanded analogs whereas the other articles deal with the expanded the A-ring.)
The synthetic pathways used to prepare the derivatives of the present invention are based on modified published literature procedures for estradiol derivatives and dimethylenamines (Trembley et al., Bioorganic & Med. Chem. 1995 3, 505-523; Fevig et al., J. Org. Chem., 1987 52, 247-251; Gonzalez et al., Steroids 1982, 40, 171-187; Trembley et al., Synthetic Communications 1995, 25, 2483-2495; Newkome et al., J. Org. Chem. 1966, 31, 677-681; Corey et al Tetrahedron Lett 1976, 3-6; and Corey et al., Tetrahedron Lett, 1976, 3667-3668]. The modifications are provided in Example 1 below. Initial screening of epimeric 16-ethyl-2-methoxyestradiol and related analogues showed that it is about equipotent to 2-methoxyestradiol in inhibition of HUVEC cell proliferation in vitro.
Administration
The compositions described above can be provided as physiologically acceptable formulations using known techniques, and these formulations can be administered by standard routes. In general, the combinations may be administered by the topical, oral, rectal or parenteral (e.g., intravenous, subcutaneous or intramuscular) route. In addition, the combinations may be incorporated into biodegradable polymers allowing for sustained release, the polymers being implanted in the vicinity of where delivery is desired, for example, at the site of a tumor. The biodegradable polymers and their use are described in detail in Brem et al., J. Neurosurg. 74:441-446 (1991). The dosage of the composition will depend on the condition being treated, the particular derivative used, and other clinical factors such as weight and condition of the patient and the route of administration of the compound. However, for oral administration to humans, a dosage of 0.01 to 100 mg/kg/day, preferably 0.01-1 mg/kg/day, is generally sufficient.
The formulations include those suitable for oral, rectal, nasal, topical (including buccal and sublingual), vaginal or parenteral (including subcutaneous, intramuscular, intravenous, intradermal, intraocular, intratracheal, and epidural) administration. The formulations may conveniently be presented in unit dosage form and may be prepared by conventional pharmaceutical techniques. Such techniques include the step of bringing into association the active ingredient and the pharmaceutical carrier(s) or excipient(s). In general, the formulations are prepared by uniformly and intimately bringing into associate the active ingredient with liquid carriers or finely divided solid carriers or both, and then, if necessary, shaping the product.
Formulations of the present invention suitable for oral administration may be presented as discrete units such as capsules, cachets or tablets each containing a predetermined amount of the active ingredient; as a powder or granules; as a solution or a suspension in an aqueous liquid or a non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil emulsion and as a bolus, etc.
A tablet may be made by compression or molding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing, in a suitable machine, the active ingredient in a free-flowing form such as a powder or granules, optionally mixed with a binder, lubricant, inert diluent, preservative, surface-active or dispersing agent. Molded tables may be made by molding, in a suitable machine, a mixture of the powdered compound moistened with an inert liquid diluent. The tablets may optionally coated or scored and may be formulated so as to provide a slow or controlled release of the active ingredient therein.
Formulations suitable for topical administration in the mouth include lozenges comprising the ingredients in a flavored basis, usually sucrose and acacia or tragacanth; pastilles comprising the active ingredient in an inert basis such as gelatin and glycerin, or sucrose and acacia; and mouthwashes comprising the ingredient to be administered in a suitable liquid carrier.
Formulations suitable for topical administration to the skin may be presented as ointments, creams, gels and pastes comprising the ingredient to be administered in a pharmaceutical acceptable carrier. A preferred topical delivery system is a transdermal patch containing the ingredient to be administered.
Formulations for rectal administration may be presented as a suppository with a suitable base comprising, for example, cocoa butter or a salicylate.
Formulations suitable for nasal administration, wherein the carrier is a solid, include a coarse powder having a particle size, for example, in the range of 20 to 500 microns which is administered in the manner in which snuff is taken, i.e., by rapid inhalation through the nasal passage from a container of the powder held close up to the nose. Suitable formulations, wherein the carrier is a liquid, for administration, as for example, a nasal spray or as nasal drops, include aqueous or oily solutions of the active ingredient.
Formulations suitable for vaginal administration may be presented as pessaries, tampons, creams, gels, pastes, foams or spray formulations containing in addition to the active ingredient such as carriers as are known in the art to be appropriate.
Formulations suitable for parenteral administration include aqueous and non-aqueous sterile injection solutions which may contain anti-oxidants, buffers, bacteriostats and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents. The formulations may be presented in unit-dose or multi-dose containers, for example, sealed ampules and vials, and may be stored in a freeze-dried (lyophilized) conditions requiring only the addition of the sterile liquid carrier, for example, water for injections, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tables of the kind previously described.
Preferred unit dosage formulations are those containing a daily dose or unit, daily sub-dose, as herein above recited, or an appropriate fraction thereof, of the administered ingredient.
2-Methoxyestradiol is an endogenous metabolite of estradiol (E2) that has potent anti-proliferative activity and induces apoptosis in a wide variety of tumor and non-tumor cell lines. When administered orally, it exhibits anti-tumor and anti-proliferative activity with little or no toxicity. In vitro data suggests that 2-methoxyestradiol does not engage the estrogen receptor for its anti-proliferative activity and is not estrogenic over a wide range of concentrations, as accessed by estrogen dependant MCF-7 cell proliferation. However, the presence of demethylases in vivo may metabolize this compound to 2-hydroxyestradiol, which has been shown to be estrogenic by several approaches. The present invention improves the bioavailibility of estradiol or 2-methoxyestradiol and to reduces the formation of estrogenic 2-methoxyestradiol metabolities. The present invention modifies estradiol or 2-methoxyestradiol in such a way that the molecule can not be converted into an uterotropic derivative.
One embodiment of the invention modifies the methyl ether of 2-methoxyestradiol so that it can not be a substrate for demethylase. Additionally, it has been demonstrated (Cushman et al J. Med. Chem. 1995, 38, 2041-2049) that other electron-rich groups at the 2-position of estradiol (propyne, propene, ethoxy) have good anti-proliferative activity in vitro. It is disclosed that modifications at C-2 of estradiol such as formyl, acetyl, methanol, 1-ethanol, 2-ethanol, amino, alkylamino, dialkyl amino, methyleneamine, methylene alkyl amine and methylene dialkylamine, and alkyl amide are be anti-proliferative and anti-angiogenic agents have reduced or removed uterotropic activity. Alkyl is defined as any carbon chain up to 6 carbons in length that is branched or straight. Listed below in Table 1 are data of 2-modified estradiol derivatives in HUVEC, MDA-MB-231 and MCF7 proliferation data. The synthetic paths for preparation of these analogs can be found in Pert et al Aust. J. Chem. 1989, 42, 405-419. Lovely et al Tetrahedron Lett. 1994, 35, 8735-8738. Gonzalez et al Steroids 1982, 40, 171-187. Nambara et al Chem. Pharm. Bull. 1970, 18, 474-480. Cushman et al J. Med. Chem. 1995, 38, 2041-2049 and methods developed in-house and are discussed below.
TABLE 1
HUVEC
MDA-MB-231
MCF7 Proliferation
Compound
(IC 50 μM)
(IC 50 μM)
Index
E2
NA
NA
13.1
2ME2
0.5
0.9
4.4
2-methyl
10
>25
7.4
hydroxy-E2
2-formyl-E2
8
>25
5.4
2-acetyl-E2
18
9
4.4
All of the 2-modified analogs presented in Table 1 have significantly less estrogenic activity (compared to estradiol) as represented by their proliferation index in estrogen dependant MCF-7 cells. All of these analogs have the capacity to from a hydrogen bond with the hydroxy group at position 3 and this may be the reason for their relatively low estrogenic character compared to estradiol. Both the 2-methylhydroxy and 2-formyl derivatives had good antiproliferative activity (IC50<10 microM) in HUVEC cells, whereas the 2-acetyl had poor activity in the same assay. In contrast, 2-methylhydroxy and 2-formyl were inactive in breast tumor MDA-MB-231 cells while 2-acetyl E2 had good activity in this cell line.
Although not wishing to be bound by theory, molecular modeling suggests that there may be a hydrogen bond that forms between the 3-hydroxy group and the methoxy group of 2-methoxyestradiol. This interaction may be important for both 2-methoxyestradiol's anti-proliferative and anti-angiogenic action as well as its non-estrogenic activity. It is claimed that any group that can be placed at position 2 of estradiol and has the potential to form a hydrogen bond with the 3-hydroxy group is an anti-proliferative and anti-angiogenic agent that lacks estrogenic activity.
It should be understood that in addition to the ingredients, particularly mentioned above, the formulations of this invention may include other agents convention in the art having regard to the type of formulation in question, for example, those suitable for oral administration may include flavoring agents.
EXPERIMENTAL DATA
The following Examples refer to the compound of the general formula:
wherein:
a) R b and R o are independently —H, —Cl, —Br, —I, —F, —CN, lower alkyl, —OH, —CH 2 —OH, —NH 2 ; or N(R 6 )(R 7 ), wherein R 6 and R 7 are independently hydrogen or an alkyl or branched alkyl with up to 6 carbons;
b) R a is —N 3 , —C≡N, —C≡C—R, —CH═CH—R, —R—CH═CH 2 , —C≡CH, —O—R, —R—R 1 —OC(O)CH 3 , —C(O)H, —NH 2 , —NMe 2 , —NHMe, or —O—R—R 1 where R is a straight or branched alkyl with up to 10 carbons or aralkyl, and R 1 is —OH, —NH 2 , —Cl, —Br, —I, —F or CF 3 ;
c) Z′ is >CH, >COH, or >C—R 2 —OH, where R 2 is an alkyl or branched alkyl with up to 10 carbons or aralkyl;
d) >C—R g is >CH 2 , >C(H)—OH, >C═O, >C═N—OH, >C(R 3 )OH, >C═N—OR 3 , >C(H)—NH 2 , >C(H)—NHR 3 , >C(H)—NR 3 R 4 , or >C(H)—C(O)—R 3 , where each R 3 and R 4 is independently an alkyl or branched alkyl with up to 10 carbons or aralkyl;
e) R h1 and R h2 are independently H, or a straight or branched chain alkyl, alkenyl or alkynyl with up to 6 carbons that is unsubstituted, or substituted with one or more groups selected from a hetero functionality (O—Y, N—Y 2 or S—Y) where Y is independently selected from H, Me or an alkyl chain up to 6 carbons; a halo functionality (F, Cl, Br or I); an aromatic group optionally substituted with hetero, halo or alkyl; or R h1 and R h2 are independently an aromatic group optionally substituted with hetero, halo or alkyl, provided that both R h1 and R h2 are not H;
f) Z″ is >CH 2 , >C═O, >C(H)—OH, >C═N—OR 5 , >C(H)—C≡N, or >C(H)—NR 5 R 5 , wherein each R 5 is independently hydrogen, an alkyl or branched alkyl with up to 10 carbons or aralkyl;
and wherein all monosubstituted substituents have either an α or β configuration.
Lower alkyl is defined as a small carbon chain having 1-8 carbon atoms. The chain may be branched or unbranched.
EXAMPLE 1
Synthesis of 2-ME Derivatives and Modifications at the 16 Position
Synthesis of the 2-ME derivatives described herein is within the capability of one ordinarily skilled in the art. A specific description of the synthesis of the 2-ME derivatives having modifications at the 2 and 6 positions and analogs discussed herein can be found in M. Cushman, H-M. He, J. A. Katzenellenbogen, C. M. Lin and E. Hamel, Synthesis, antitubulin and antimitotic activity, and cytotoxicity of 2-methoxyestradiol, and endogenous mammalian metabolite of estradiol that inhibits tubulin polymerization by binding to the colchicine binding site, J. Med. Chem., 38(12): 2042 (1995); and M. Cushman, H-M. He, J. Katzenellenbogen, R. Varma, E. Hamel, C. Lin, S. Ram and Y. P. Sachdeva, Synthesis of analogs of 2-methoxyestradiol with enhanced inhibitory effects on tubulin polymerization and cancer cell growth, J. Med. Chem. 40(15): 2323 (1997).
The synthetic pathways used to prepare the derivatives of the estradiol derivatives modified at the 16 position of the present invention are based on modified published literature procedures for estradiol derivatives cited earlier. Examples of the modifications are provided in Examples 2 through 23 below.
EXAMPLE 2
Preparation of 3-Benzyl-2-methoxyestradiol
2-Methoxyestradiol (10.09 g, 33.4 mmol) and potassium carbonate (22 g, 278 mmol) were suspended in anhydrous ethanol and cooled to 0° C. Benzyl bromide (11.4 mL, 95.8 mmol) was added dropwise, and following the addition, the mixture was brought to reflux for 8 h. The solution was cooled to room temperature (rt), and the solvent was removed via rotoevap. The resulting residue was diluted with approximately 200 ml water, and washed with ethyl acetate (3×200 mL). The combined organics were washed with water (200 mL), sodium bicarbonate (saturated (satd), 200 mL) and brine (200 mL). Dry with sodium sulfate, filter and roto-evaporation (rotoevap). Product was dried under vacuo with occasional gentle heating using a heat gun to give a yellowish glass (13.54 g, quanitative yield) and used without further purification.
Selected spectral data: 1 H-MNR (300 MHz, CDCl 3 ) δ 7.29-7.53 (m, 5H), 6.88 (s, 1H), 6.65 (s, 3H), 5.11 (s, 2H), 3.87 (s, 3H), 3.7 (t, J=8 Hz, 1H), 0.80 (s, 3H). FT-IR (neat) 3341, 2920, 2864, 1605, 1513, 1453, 1254, 1211, 1117, 1022 cm −1 .
EXAMPLE 3
Preparation of 3-Benzyl-2-methoxyestrone
Oxalyl chloride (38 mmol, 19 mL, 2M, methylene chloride) was added to anhydrous methylene chloride (25 mL) and cooled to −46° C. Methyl sulfoxide (5.40 mL, 76 mmol) was added dropwise, and the mixture was stirred for 2 minutes. 3-Benzyl-2-methoxyestradiol in methylene chloride/methyl sulfoxide (10 mL/15 mL) and added within 5 minutes and the resulting mixture was stirred for 1 h. Triethyl amine (170 mmol, 23.5 mL) was added drop-wise, stirred 5 minutes and warmed to rt. Water (˜200 mL) was added and the mixture was washed with methylene chloride (3×200 mL). The combined organics were washed with water (200 mL), dilute HCl (1% aq., 200 mL), sodium carbonate (satd, 200 mL) and brine (200 mL). The organics were dried with magnesium sulfate, filtered and rotoevaped to give a white solid. The solid was crystallized with hot ethanol to give white crystals (9.94 g, 25.5 mmol, 76% overall yield from 2-methoxyestradiol).
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 7.28-7.48 (m, 5H), 6.86 (s, 1H), 6.66 (s, 1H), 3.88 (s, 3H), 0.94 (s, 3H). IR (neat) 2920, 1731, 1519, 1202, 1012 cm −1 .
EXAMPLE 4
Representative Preparation of 16α-alkyl-3-benzyl-2-methoxyestrone
Lithium diisopropyl amide (2M, Aldrich, heptane/THF/ethylbenzene) was dissolved in THF and cooled to −78° C., and 3-benzyl-2-methoxyestrone in THF (10 mL) was added dropwise. Following addition, the mixture was warmed to 0° C. and stirred 1 hour (h). The mixture was then cooled to −78° C. and DMPU (1 mL) followed by crotyl bromide (205 μL, 2.0 mmol) were added dropwise. The mixture was warmed to rt over 4 h. The reaction was quenched by carefully adding water (100 mL) and washing with ethyl acetate (2×100 mL). The combined organics were washed with water (100 mL) and brine (100 mL). The solution was dried with magnesium sulfate, filtered and rotoevaped. The crude product was purified using hexane/ethyl acetate (9:1) SiO 2 Biotage FLASH apparatus. 680 mg (1.53 mmol) of product was obtained and approximately 121 mg (0.31 mmol) of starting material was recovered (90% yield based on recovered starting material). Diastereomeric ratio of 16 α/β is approximately 2:1 (s H18 signals at 0.88, 0.79 ppm).
Selected spectral data: 1 H-MNR (300 MHz, CDCl 3 ) δ 7.28-7.48 (m, 5H), 6.86 (s, 1H), 6.66 (s, 1H), 5.34-5.59 (m, 2H), 5.13 (s, 2H), 3.88 (s, 3H), 0.87 & 0.97 (s, total 3H, ratio 1:2).
EXAMPLE 5
Representative Preparation of 16β-alkyl-3-benzyl-2-methoxyestrone
3-Benzyl-2-methoxyestrone (1.175 g, 3.0 mmol) was dissolved in anhydrous THF (15 mL), cooled to −78° C. and lithium diisopropyl amide (2M Aldrich, heptane/THF/ethylbenzene) was added dropwise and stirred 1 h. DMPU (1 mL) followed by crotyl bromide (302 μL) were added and the mixture warmed to rt over 24 h. Workup as above and purify using hexane:ethyl acetate (4:1) SiO 2 flash column gave 492 mg purified product (1.1 mol, 37% yield).
Selected spectral data: 1 H-MNR (300 MHz, CDCl 3 ) δ 7.28-7.48 (m, 5H), 6.86 (s, 1H), 6.66 (s, 1H), 5.62-5.34 (m, 2H), 5.13 (s, 2H), 3.89 (s, 3H), 0.98 and 0.87 (s, 3H total, ratio 2:1). IR (neat) 2928, 2854, 1732, 1606, 1508, 1452, 1215, 1016 cm −1 .
EXAMPLE 6
Representative Preparation of 16β-alkyl-3-benzyl-2-methoxyestrone
3-benzyl-16-carbomethoxy-2-methoxyestrone (0.840 g, 1.87 mmol), potassium hydride (1.5 g, 10.9 mmol, 30% mineral oil dispursion, washed in hexanes) and 18-crown-6 (120 mg, 0.4 mmol) was mixed in THF (40 mL) and refluxed for 1 h. The mixture was cooled to rt, and allyl bromide (537 μL, 6.2 mmol) was added and the mixture was refluxed for 18 h. After cooling to rt, the reaction was quenched by carefully adding approximately 2 ml of water with stirring, then adding an additional 100 mL water. This mixture was washed with ethyl acetate (2×100 mL) and the combined organics were washed with brine (100 mL). The organics were dried with magnesium sulfate, filtered and rotoevaped. Purification using 85:5 hexanes:ethyl acetate SiO 2 Biotage FLASH apparatus yielded 697 mg of product (1.42 mol, 76% yield).
Selected spectral data: 1 H-MNR (300 MHz, CDCl 3 ) δ 7.28-7.48 (m, 5H), 6.85 (s, 1H), 6.66 (s, 1H), 566-5.79 (m, 1H), 5.15-5.20 (m, 2H), 5.13 (s, 2H), 3.88 (s, 3H), 3.75 (s, 3H), 0.99 (s, 3H).
EXAMPLE 7
Representative Decarboxylation of 16-alkyl-16-carbomethoxy-3-benzyl-2-methoxyestrone
16-allyl-16-carbomethoxy-3-benzyl-2-methoxyestrone (697 mg, 1.42 mmol), lithium chloride (1.15 g, 27 mmol), water (485 μL, 27 mmol) were dissolved in DMF (63 mL) and refluxed for 20 h. Cool to rt, add 1N HCl (100 mL) and wash with ether (2×100 mL) the combined organics were washed with water (100 mL), and brine 100 mL), dry with magnesium sulfate, filter and rotoevap. Purification by 85:15 hexanes:ethyl acetate SiO 2 Biotage Flash apparatus gave 271 mg product and 189 mg recovered starting material. Starting material was resubjected to the reaction (308 mg LiCl, 132 μL, water, 17 mL DMF) for 28 h and worked up as above to give 130 mg product. Overall yield for reaction was 66% (401 mg, 0.93 mmol).
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 7.28-7.48 (m, 5H), 6.85 (s, 1H), 6.65 (s, 1H), 5.69-5.88 (m, 1H), 5.13 (s, 2H), 5.00-5.08 (m, 2H), 5.88 (s, 3H), 0.98 nd 0.88 (s, total 3H, ratio 1:1.4). FT-IR (neat), 2925, 2855, 1726, 1514, 1214, 1103 cm −1 .
EXAMPLE 8
Preparation of 16-methane-dimethylenamine-3-benzyl-2-methoxyestrone
3-benzyl-2-methoxyestrone (1.51 g, 3.87 mmol) was suspended in tert-butoxy bis(dimethylamino)methane (1.64 mL, 8.13 mmol) and heated in an oil bath (155° C.) for 1.5 h, during which time the steroid dissolved. The reaction mixture was cooled to rt, and poured into ice water (100 mL) and washed with methylene chloride (2×100 mL). The organics were washed with brine (100 mL) dried with magnesium sulfate, filtered and rotoevaped to give product which was used without further purification (1.82 g, quanitative yield).
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 7.23-7.47 (m, 5H), 6.87 (s, 1H), 6.64 (s, 1H), 5.12 (s, 2H), 3.88 (s, 3H), 3.07 (s, 6H), 0.91 (s, 3H).
EXAMPLE 9
Preparation of 16-carbomethoxy-3-benzyl-2-methoxy estrone
3-Benzyl-2-methoxyestrone (1.6113 g, 2.978 mmol) was dissolved in THF (15 mL), cooled to −78° C. and lithium diisopropyl amide (2M, Aldrich, Heptane/THF/ethylbenzene) was added dropwise and stirred for 1 h. Methyl cyanoformate (237 μL, 3 mmol) in DMPU (1 mL) was added and the mixture warmed to rt over 18 h. Water (100 ml) was carefully added, and the mixture was washed with ethyl acetate (3×100 mL) and the combined organics were washed with brine (100 mL), dried with sodium sulfate, filtered and rotoevaped. Final purification of product using hexane:ethyl acetate (85:15) then switching to hexane: ethyl acetate (75:25) SiO 2 flash column yielded 806 mg product (1.8 mmol, 60%).
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 7.28-7.48 (m, 5H), 6.85 (s, 1H), 6.66 (s, 1H), 5.13 (s, 2H), 3.88 (s, 3H), 3.78 (s, 3H), 3.23 (dd, J=9, 10 Hz, 1H), 1.0 (s, 3H). FT-IR (neat) 2929, 2860, 1750, 1723, 1604, 1508, 1211, 1014 cm −1 .
EXAMPLE 10
Representative Procedure for Preparation of 16-alkyl-3-benzyl-2-methoxyestra-17β-diol
16α-crotyl-3-benzyl-2methoxyestrone (680 mg, 1.53 mmol) was dissolved in anhydrous THF (10 mL), and cooled to −78° C. Lithium aluminum hydride (3.06 mmol, 116 mg) was added and the solution was stirred for 2 h. The reaction was quenched by carefully adding water (2 mL) and warming to rt, then adding additional 50 mL portion of water. The mixture was washed with ethyl acetate (2×50 mL) and the combined organics were washed with water (50 mL), brine (50 mL), dried with magnesium sulfate, filtered and rotoevaped. The mixture was purified with 3:1 hexane:ethyl acetate SiO 2 Biotage FLASH apparatus to give 500 mg purified product (1.12 mmol, 73% yield).
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 7.28-7.48 (m, 5H), 6.87 (s, 1H), 6.64 (s, 1H), 5.47-5.56 (m, 2H), 5.12 (s, 2H), 3.88 (s, 3H), 3.8 (d, J=9 Hz) and 3.33 (d, J=8Hz) total 1H, ratio 1:1.7, 0.84 and 0.81 (s, 3H total).
EXAMPLE 11
Preparation of 16-methanol-3-benzyl-2-methoxyestradiol
Reaction procedure and work up as above, (used 806 mg, 1.8 mmol 16-carbomethoxy-3-benzyl-2-methoxyestrone), except warm to rt for 2 h before quenching. Purify final product with 3:2 hexane:ethyl acetate SiO 2 flash column. Obtain 304 mg β isomer, 51 mg α isomer which were separated by chromatography. Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ Major isomer 7.28-7.48 (m, 5H), 6.87 (s, 1H), 6.64 (s, 1H), 5.12 (s, 2H), 3.97 (d, J=10 Hz), 3.88 (s and obscured d, 4H), 3.67 (dd, J=4, 7 Hz, 1H), 0.87 (s, 3H). Minor isomer 7.28-7.47 (m, 5H), 6.86 (s, 1H), 6.64 (s, 1H), 3.88 (s, 3H), 3.83 (d, J=14 Hz, 1H), 3.69 (t, J=9 Hz, 1H), 3.54 (d, J=7 Hz, 1H), 0.87 (s, 3H).
EXAMPLE 12
Representative Debenzylation of 16-alkyl-3-benzyl-2-methoxyestradiol
16α-crotyl-3-benzyl-2-methoxyestradiol (500 mg, 1.12 mmol) was dissolved in ethyl acetate (25 mL) in Parr reaction bottle. The bottle was flushed with argon, and Pd/C (10%, 2.5 g) was added. The bottle was fitted to a Parr hydrogenator, filled and purged with hydrogen five times, pressurized to 50 psi, and agitated for 24 h. The mixture was filtered through a celite pad, rotoevaped and purified with a 3:1 hexane ethyl acetate SiO 2 flash column. Obtain 358 mg product (1.0 mmol, 89%).
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 6.81 (s, 1H), 6.66 (s, 1H), 3.87 (s, 3H), 3.76 (d, J=10 Hz) and 3.29 (d, J=8 Hz) (total 1H, ratio 1:2), 0.82 and 0.79 (s, 3H). FT-IR (neat) 3245, 2914, 1606, 1523, 1414, 1258, 1028 cm −1 . Analysis calculated (Anal. Calcd) for C 20 H 34 O 3 : C, 77.44; H, 9.56. Found: C, 76.64; H, 9.51.
EXAMPLE 13
16β-methyl-2methoxyestradiol
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 6.81 (s, 1H), 6.66 (s, 1H), 3.87 (s, 3H), 3.73 (d, J=10 Hz) and 3.23 (d, J=8 Hz) (total 1H, 2:1), 0.83 and 0.81(s, 3 H total). Anal. Calcd for C 20 H 28 O 3 , ¼ H 2 O: C, 74.85; H, 8.95. Found: C, 74.93; H, 8.94.
EXAMPLE 14
16α-methyl-2methoxyestradiol
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 6.81 (s, 1H), 6.66 (s, 1H), 3.87 (s, 3H), 3.23 (d, J=7 Hz) (s, 1H), 0.81 (s, 3 H). Anal. Calcd for C 20 H 28 O 3 , ¼ H 2 O: C, 74.85; H, 8.95. Found: C, 74.98; H, 8.65.
EXAMPLE 15
Racemic 16-ethyl-2-methoxyestradiol
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 6.82 (s, 1H), 6.66 (s, 1H), 3.88 (s, 3H), 3.76 (d, J=9 Hz) and 3.30 (d, J=10 Hz), (1H total, ratio 1:1), 0.83 and 0.79 (s, 3H total). FT-IR (neat) 3214, 2918, 1605, 1522, 1229, 1201, 1024 cm −1 . Anal. Calcd for C 21 H 30 O 3 : C, 76.33; H, 9.15. Found: C, 76.18; H, 9.16.
EXAMPLE 16
16α-n-propyl-2-methoxyestradiol
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 6.81 (s, 1H), 6.66 (s, 1H), 5.43 (s, 1H), 3.87 (s, 3H), 3.29 (t, J=7 Hz, 1H), 0.95 (t, J=7 Hz, 3H), 0.83 and 0.80 (s, total 3H, ratio 7.3:1). Anal. Calcd for C 22 H 32 O 3 : C, 76.69; H, 9.37. Found: C, 76.55; H, 9.44.
EXAMPLE 17
16β-n-propyl-2-methoxyestradiol
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 6.81 (s, 1H), 6.66 (s, 1H), 3.87 (s, 3H), 3.76 (d, J=10 Hz) and 3.29 (t, J=7 Hz) (total 1H, ratio 2:1), 0.95 (t, J=7 Hz, 3H), 0.83 and 0.80 (s, total 3H). FT-IR (neat) 3411, 2923, 1504, 1446, 1267, 1202, 1118, 1024 cm −1 . Anal. Calcd for C 22 H 32 O 3 , ¼ H 2 O: C, 75.71; H, 9.39. Found: C, 75.61; H, 9.33.
EXAMPLE 18
16β-n-butyl-2-methoxyestradiol
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 6.81 (s, 1H), 6.66 (s, 1H), 5.43 (s, 1H), 3.88 (s, 3H), 3.76 (d, J=10 Hz) 3.29 (d, J=8 Hz) (total 1H, ratio 2.6:1), 0.83 and 0.80 (s, total 3H). FT-IR (neat) 3221, 2921, 1594, 1504, 1416, 1265, 1200, 1021 cm −1 . Anal. Calcd for C 23 H 34 O 3 : C, 77.04; H, 9.56. Found: C, 77.06; H, 9.65.
EXAMPLE 19
16β-isobutyl-2-methoxyestradiol
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 6.81 (s, 1H), 6.66 (s, 1H), 5.43 (s, 1H), 3.88 (s, 3H), 3.77 (dd, J=9, 10 Hz) and 3.26 (t, J=7 Hz) (total 1 H, ratio 2:1), 0.84 and 0.80 (s, total 3H). IR (neat) 3525, 2913, 1506, 1258, 1202, 1026 cm −1 . Anal. Calcd for C 22 H 30 O 3 : C, 76.69; H, 9.37. Found: C, 76.82; H, 9.47.
EXAMPLE 20
16β-methyl(dimethyl amine)-2-methoxyestradiol
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 6.81 (s, 1H), 6.65 (s, 1H), 3.88 (s) and 3.85 (obscured d) (total 4H), 2.28 (s, 6H), 0.87 (s, 3H). Anal. Calcd for C 22 H 33 O 3 N, ¼ H 2 O: C, 72.59; H, 9.28; N, 3.85. Found: C, 72.80; H, 9.17; N, 3.66.
EXAMPLE 21
16β-methanol-2-methoxyestradiol
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 6.78 (s, 1H), 6.61 (s, 1H), 3.92 (d, J=11 Hz, 1H), 3.84 (s, 3H), 3.80 (d, J=10 Hz, 1H), 3.63 (d, J=8, 11 Hz, 1H), 0.83 (s, 3H). FT-IR (neat) 3283, 3091, 2919, 1602, 1513, 1445, 1204, 1119, 1013 cm −1 . Anal. Calcd for C 20 H 28 O 4 : C, 72.25; H, 8.49. Found: C, 72.24; H, 8.48.
EXAMPLE 22
16α-methanol-2-methoxyestradiol
Selected spectral data: 1 H-NMR (300 MHz, CDCl 3 ) δ 6.77 (s, 1H), 6.61 (s, 1H), 3.84 (s, 3H), 3.84 (dd, J=7, 8 Hz, 1H), 3.61 (dd, J=9, 11 Hz, 1H), 3.45 (d, J=8 Hz, 1H), 0.83 (s, 3H).
EXAMPLE 23
MDA-MB-231 In Vitro Cellular Proliferation Inhibition
MDA-MB-231 Cells and Culture Conditions
FIG. 1 illustrates the antiproliferative activity in cells and tumor by 2-methoxyestradiol compounds of the present invention which are modified at the 16 position.
MDA-MB-231 human breast carcinoma cells were grown in DMEM containing 10% FCS (Hyclone Laboratories, Logan Utah.) and supplemented with 2 mM L-Glutamine, 100 units/ml penicillin, 100 μg/ml streptomycin (Irvine Scientific, Santa Anna, Calif.).
Proliferation Assays
MDA-MB-231 cells were plated at 5000 cells/ml in 96-well plates. After allowing the cells to attach overnight, the appropriate fresh media were applied containing differing concentrations of 2-ME2 or derivatives thereof, as described below. Drug was dissolved in DMSO (Sigma, St. Louis, Mo.) and added to the wells in a volume of 200 μl. Cells were incubated for two days at 37° C.; at 32 h BrdU was added. BrdU cell proliferation assay (a nucleotide analogue with a fluorescein tag that is incorporated into DNA) was performed as described by the manufacturer (Roche). Each condition was prepared in triplicate and the experiments were carried out a minimum of two times. Results are presented and means±SE.
EXAMPLE 24
HUVAC In Vitro Cellular Proliferation Inhibition HUVAC Cells and Culture Conditions
HUVAC cells were grown in EGM (Clonetics)
Proliferation Assays
HUVEC cells were plated at 5000 cells/ml in 96-well plates. After allowing the cells to attach overnight, the cells were washed with PBS and incubated in the absence of growth factor for 24 h (EBM, 2% FCS, Clonetics). Cells were treated with increasing concentrations of drug in EBM containing 2% FCS and 10 ng.ml bFGF for 48 h at 37° C. Drug preparation, volumes added and BrdU proliferation assay were performed as indicated above.
Results
The breast cancer cell line activities and the cell panels most sensitive to selected analogs are shown in Table 2.
TABLE 2
α/β ratio at
HUVEC
MDA-MB-231
R
position 16
IC 50 (μM)
IC 50 (μM)
H
N/A
0.5
0.9
methyl (—CH 3 )
All alpha
<0.5
<0.5
methyl
1:2
1.3
5
ethyl (—CH 2 CH 3 )
1:1
2
3
n-propyl
7.3:1
6
>50
(—CH 2 CH 2 CH 3 )
n-propyl
1:2
9
36
i-butyl
1:2
7.5
40
n-butyl
2:1
25
82
(—CH 2 CH 2 CH 2 CH 3 )
n-butyl
1:2.6
9
39
methanol
All alpha
15
22
(—CH 2 OH)
methanol
All beta
5
50
Methyl-
All beta
9
22
dimethylamine
2-Methoxyestradiol is a potent anti-angiogenic and anti-tumor agent. In order to assess the biological activity of modifications at position 16, the anti-proliferative activity of these analogs was evaluated on human umbilical vein endothelial cells (HUVEC) and breast carcinoma cell line, MDA-MB-231 as models for the anti-angiogenic and anti-tumor activity, respectively. It was found that a moderate decrease (approximately 18 fold) in anti-proliferative activity occurs as steric bulk increased (note trend from R=Et to R=Bu). The most active compound in this series is 16α-methyl, which has greater activity than 2-methoxyestradiol.
The MDA-MB-231 tumor cell line, has a much greater sensitivity to substitutions at position 16 compared to HUVEC cells. Any group at position 16 larger than ethyl has a significant decrease in antiproliferative activity (IC 50 >22 μM). Of the active compounds, 16α-methyl has better activity than 2-methoxyestradiol, whereas 16β-methyl (which is a 1:2 mixture of α:β, so the presence of the α isomer may account for this activity) has about 5-fold less activity than 2-methoxyestradiol, and racemic 16-ethyl has about a 3-fold drop in activity compared to 2-methoxyestradiol.
These data suggest that it is possible to design compounds that are selective anti-angiogenic agents. For example, 16α-propyl is greater than ten-fold less active in inhibiting tumor growth while it has good activity inhibiting endothelial cell proliferation. Other examples include: 16β-propyl (4-fold difference), 16β-i-butyl (5-fold difference), 16β-n-butyl (4-fold difference) and 16β-methanol (10-fold difference). Additionally, a small alkyl group at position 16 can be added without significantly impacting the anti-proliferative activity of the molecule.
All of the publications mentioned herein are hereby incorporated by reference in their entireties. The above examples are merely demonstrative of the present invention, and are not intended to limit the scope of the appended claims. | Compositions and methods for treating mammalian disease characterized by undesirable angiogenesis by administering derivatives of 2-methoxyestradiol of the general formula:
wherein the variables are defined in the specification. | 2 |
REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Application No. 10/938,999, which was filed on Sep. 10, 2004, the contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of bioresorbable packing and stents, and more specifically to a method of making flexible bioresorbable foam, useful for post-operative or drug delivery use, having both hemostatic properties and a preselectable in-vivo residence time.
BACKGROUND OF THE INVENTION
[0003] Various types of sterile packing and stents are used in the medical and surgical fields for keeping tissues apart or preventing adhesion. Such uses include, but are not limited to, nasal packing and sinus stents, packing for inner ear surgery, tympanoplasty, exostosis, orbital decompression, as well as various orifice restenosis prevention uses. Personal uses such as tampons, bandaging and the like also involve sterile packing materials.
[0004] Such packing and stents have been made from gauzes, microfibers, non-fibrous expandable packing, such as tampons, and the like. These types of packing are not bioresorbable and can cause injury or discomfort upon removal, as well as causing toxic shock syndrome if left internally for more than a day or two.
[0005] In an attempt to prevent such reactions, while continuing to prevent adhesion and tissue necrosis, resorbable packing and stent devices have been developed. Such packing materials have typically included hyaluronic acid (HA), or salts of hyaluronic acids, which are naturally occurring mucopolysaccharides found in various body fluids and connective tissues. Thus, HA is biocompatible. It has been adapted for use as a surgical aid to prevent tissue contact and adhesion formation.
[0006] However, HA has a very high solubility, and thus poor liquid absorption, and tends to quickly disperse when exposed to such liquids. This reduces HA materials' effectiveness in areas such as surgical wounds that exude blood and other fluids. Crosslinking has created somewhat insoluble HA materials.
[0007] Further, other biocompatible materials such as polysaccharides, especially methylcellulosic materials have been combined with the hyaluronic acid to produce packing materials that are resorbable but are also insoluble and have a longer in-vivo residence time before they dissolve into gels and are absorbed by the body tissues. These materials also have increased fluid absorption capabilities. Such materials stop bleeding only by effect of compression and packing and do not have any inherent hemostatic properties.
[0008] Collagen is also known for use in the medical field. It is a major protein constituent of connective tissue and is widely used in medical and surgical applications such as sutures, grafts and surgical prostheses. Typical sources include calfskin, bovine Achilles tendons, cattle bones, porcine tissue, human cadaver tissue, and rat tails. Collagen, as an animal protein, is bioresorbable, even when crosslinked to reasonable levels. Collagen is available in a variety of forms including powders and fibrils, and in aqueous solution. Collagen may be provided in insoluble or soluble forms.
[0009] It has now been discovered that a flexible bioresorbable foam for packing, post-operative use, and other medical uses may be created having both hemostatic properties and a variable preselectable resorption time (also known as an in-vivo residence time). The foam is formed from a blend of collagen and hyaluronic acid or derivative thereof.
SUMMARY OF THE INVENTION
[0010] An embodiment of the invention provides a method of making flexible bioresorbable foam having hemostatic properties and a variable preselectable resorption time comprising the steps of:
providing a blend of collagen and an hyaluronic acid component comprising from about 70 to about 90 weight percent of the esterified hyaluronic acid; mixing with water to form a suspension; freezing and lyophilizing the blend at 0° C. or below; crosslinking to form a flexible crosslinked product; and sterilizing and performing chain scission on the crosslinked product by means of bombardment with gamma rays or electrons.
[0016] In one method of making the bioresorbable flexible foam of an embodiment of the invention, the foam is crosslinked using a chemical crosslinking agent.
[0017] These terms when used herein have the following meanings.
[0018] The term “bioresorbable” as used herein, means capable of being absorbed by the body.
[0019] The term “ hemostat” means a device or material which stops blood flow.
[0020] The term “stent” means a material or device used for separating tissue and holding it in such separated position.
[0021] The term “lyophilizing” means freeze-drying.
[0022] The term “resorption time” and “in-vivo residence time” are used interchangeably, and refer to the time between insertion into the body and the time at which the material has been substantially absorbed into the tissues.
[0023] The term “adhesion” as used herein, refers to the sticking together of tissues which are in intimate contact for extended periods.
[0024] The term “preselectable in-vivo residence time” means that foams of the invention may be formed that will have different in-vivo residence times to be useful for different applications.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] The following detailed description describes certain embodiments and is not to be taken in a limiting sense. The scope of the present invention is defined by the appended claims.
[0026] The bioresorbable hemostatic packing provided herein may be used in any manner in which sterile packing and/or stents are normally used in the surgical or medical fields, including uses for which control of low weight bleeding and adhesion prevention are important. Such uses include, but are not limited to, nasal packing and sinus stents, packing for inner ear surgery, tympanoplasty, exostosis, orbital decompression, as well as various orifice restenosis prevention uses. The packing materials may also be used as single or combination drug delivery systems for humans or mammals.
[0027] Bioresorbable foams of an embodiment of the invention are formed from a blend of a hyaluronic acid component and collagen. Varying ratios of the components may be used in the blends according to the application desired, e.g., 50/50, 60/40 etc. A typical blend may comprise from about 70 to about 90 weight percent of the hyaluronic acid component, and correspondingly from about 10 to about 30 weight percent of collagen. In one embodiment, the blend contains from about 70 to about 80 weight percent of the hyaluronic acid or derivative thereof. The ratios of such blends can be selected by the particular application anticipated. For example, higher amounts of collagen will increase the hemostatic effect somewhat.
[0028] Collagen materials useful in blends of an embodiment of the invention are absorbable collagen materials from any source, e.g., corium collagen, tendon collagen, and the like, available commercially from such companies as Datascope® and Fibrogen, Inc. In one embodiment, the blends are formed of a microfibrillar collagen foam that includes a collagen flour. Such collagen materials are available from Davol Inc., a subsidiary of C. R. Bard, Inc., as Avitene®.
[0029] Useful hyaluronic acid components include hyaluronic acid, derivatives thereof, and mixtures thereof. One particularly useful derivative is esterified hyaluronic acid. Useful ester derivatives may be partial or total esters of hyaluronic acid; e.g., hyaluronic acid esterified with aliphatic or araliphatic esters such as ethyl esters, octadecyl esters, benzyl esters and mixtures thereof. In one embodiment the blend comprises a partial esterified hyaluronic acid; especially, an esterified HA having an esterification of at least about 60%. One useful esterified hyaluronic acid has an esterification level of from about 60% to about 70%. Such materials are available commercially from Fidia Advanced Biopolymers, S.r.l. under the trade name Hyaff®.
[0030] The in-vivo residence times of flexible foams of an embodiment of the invention may be selected to be from about 5 days to about 28 days; in some embodiments, the foam will have an in-vivo residence time of from about 5 days to about 14 days. The in-vivo residence time for the flexible bioresorbable foams of an embodiment of the invention is controlled by adjusting the re-suspension shear parameters, the level of crosslinking of the foam ingredients to produce the desired level; the sterilization bombardment must also be controlled in order to control the chain scission caused by such bombardment.
[0031] In one embodiment, the foams are formed by a method that includes the formation of a suspension of the collagen and the esterified hyaluronic acid in water. The suspension is formed by mixing with conventional mixers until suspended. The suspension is mixed at a shear rate of from about 0.25 minutes/liter to about 3.0 minutes/liter, and at a speed of from about 7,000 rpm to about 10,000 rpm. The suspension is then metered into lyophilization trays with a series of cavities. Typical trays have cavities nominally about 4 cm by 1.3 cm by 1 cm.
[0032] The suspended solution is then freeze-dried into solid foam blocks using well known procedure involving vacuum conditions at temperatures that are less than the freezing temperature of water, i.e., less than 0° C. After 0° C. is reached, the temperature is then reduced further over time, and cycled; e.g., the temperature is reduced by a few degrees then maintained at the lower temperature for a period of time, and then reduced again.
[0033] Finally, the temperature reaches a low of about −45° C. where it is maintained for the period required to complete the lyophilization. In certain embodiments, the lyophilization can be more than 10 hours, and perhaps as much as 24-30 hours. The drying portion of the lyophilization is performed at a vacuum set point of about 75 mm of mercury (Hg) with the temperature being raised to about 0° C. and maintained there for at least about 2 hours, and up to about 6 hours, then raised to at least about 25° C. to a period of from about 4 hours to about 40 hours.
[0034] Upon completion of lyophilization, the foam is then ready to be crosslinked. Crosslinking may be accomplished by dehydrothermal crosslinking, or by exposure to a chemical crosslinking agent. In dehydrothermal crosslinking, the foam is dehydrated to reduce the moisture content to the temperature at which crosslinking occurs, typically to less than about 1%. The product is subjected to elevated temperatures and/or vacuum conditions until crosslinking occurs. Useful combinations of such conditions include vacuum of at least about 10−5 mm of mercury, and temperatures of at least about 35° C. Naturally, if vacuum is not used, much higher temperatures are required, e.g., above 75° C. The conditions are maintained for at least about 10 hours, typically for about 24 hours until the desired molecular weight has been achieved.
[0035] If chemical crosslinking is desired, useful chemical crosslinking agents include aldehydes, e.g., formaldehyde vapor, which can be used by pumping it into a room containing the lyophilized foam and allowed to contact the foam for at least about 2 hours, preferably at least about 5 hours. After the desired exposure time is complete, the crosslinking agent is evacuated from the room.
[0036] After crosslinking, the foam is then ready for compression, packaging and sterilization, typically by bombardment with gamma rays or electron beam bombardment. The bombardment both kills bacteria and performs chain scission on the foam. It is important that the sterilization/chain scission procedure and the crosslinking procedure be balanced to produce the desired crosslinking level to achieve the in-vivo residence time desired. The bioresorbable foam of the invention is flexible and does not require any rehydration.
[0037] The bioresorbable foam of the invention can be easily handled either wet or dry and may be squeezed, and/or cut to required size. The foam will contour to the body cavity or wound as required, and provides chemical hemostasis as well as preventing adhesion, and minimizing swelling and edema.
[0038] Although specific embodiments have been illustrated and described herein for purposes of description of the preferred embodiment, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations calculated to achieve the same purposes may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. Those with skill in the chemical, mechanical, biomedical, and biomaterials arts will readily appreciate that the present invention may be implemented in a very wide variety of embodiments. This application is intended to cover any adaptations or variations of the preferred embodiments discussed herein. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof. | The invention provides a method of making flexible bioresorbable foam having hemostatic properties and a preselectable in-vivo residence time. A blend of crosslinked collagen blended and a hyaluronic acid component is prepared. The blend is mixed with water to form a suspension. The blend is freezed and lyophilized at less than about 0° C. Next, the blend is crosslinked. The product is then sterilized and chain scission is performed by bombardment with gamma rays or a beam of electrons. | 0 |
CROSS REFERENCE OF RELATED APPLICATIONS
[0001] This patent application is a nonprovisional patent application of and claims priority from the provisional patent application Ser. No. 62/333,352 filed on May 9, 2016, and this patent application also claims the benefit of the provisional patent application Ser. No. 62/342,532 filed on May 27, 2016, both of which are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] This invention was not made pursuant to any federally-sponsored research and/or development.
[0003] A prior invention (Management Center Module for Advanced lane Management Assist—U.S. Pat. No. 9,053,636) provides a method and system for assisting the drivers of vehicles, and the intelligent in-vehicle systems in partially and fully automated vehicles to select a specific lane for vehicle travel on limited access highways as well as a recommended speed. That patent employs current lane specific information from traffic detectors in the roadway or from other sources. The present invention develops predicted information from these sources and substitutes it for the current information where appropriate, thus improving the timeliness of the information.
BACKGROUND
[0004] This patent application extends the usefulness of the following two prior patents, the disclosures of which are hereby incorporated by reference in their entirety, as if fully set forth herein:
U.S. Pat. No. 9,053,636 Management Center Module for Advanced Lane Management Assist for Automated Vehicles and Conventionally Driven Vehicles (ALMAMC) U.S. Pat. No. 9,286,800 Guidance Assist Vehicle Module (ALMAVM)
[0007] These patents describe a methodology (ALMA) for using traffic management center (TMC) information to select a most appropriate freeway lane for a driver or automated vehicle and to provide a target speed for that lane. The TMC traffic condition information, is essentially current information on traffic speed and other variables for each through traffic lane. The information is organized according to a data structure described in in the ALMAMC patent that considers the physical and functional features of the freeway as well as traffic information devices. The information is transmitted to the vehicle where it is further processed (ALMAVM). This additional processing develops guidance on the best lane and target speed by looking at traffic speeds for several miles ahead (downstream) of the vehicle's current position.
[0008] Since the vehicle may not reach the look-ahead distance for a few minutes, the current patent improves the performance of the prior patents by using predicted traffic speed in place of current traffic speed for lane selection and target speed recommendations. To obtain lane based speed information, TMCs may use sources such as roadway based traffic detectors and reports from connected vehicles that include position, speed and lane identification. Prediction for other key parameters provided by the ALMAMC patent is provided.
[0009] Pan et al 1 provide a review of traffic prediction techniques. Examples of prediction techniques include: 1 BEI PAN, UGUR DEMIRYUREK, and CYRUS SHAHABI, Utilizing Real-World Transportation Data for Accurate Traffic Prediction, Integrated Media System Center, University of Southern California.
1. Simulation Models—Traffic prediction using microscopic simulation models in conjunction with traffic detector measurements. References include Gehrke and J. Wojtusiak 2 and Ben Akiva et al 3 . 2 JAN D. GEHRKE and JANUSZ WOJTUSIAK, A Natural Induction Approach to Traffic Prediction for Autonomous Agent-based Vehicle Route Planning, Machine Learning and Inference Laboratory, MLI 08-1, George Mason University, Feb. 17, 2008. 3 MOSHE BEN-AKIVA, MICHEL BIERLAIRE, HARTS KOUTSOPOULOS, and RABI MISHALANI, DynaMIT: a simulation-based system for traffic prediction, Massachusetts Institute of Technology Intelligent Transportation Systems Program, Presented Paper presented at the DACCORD Short Term Forecasting Workshop February, 1998. 2. Data Mining Techniques—This class analyzes the data collected by traffic detectors. Various analysis approaches include:
A. Auto-Regressive Integrated Moving Average (ARIMA) Model. 4 The Exponential Smoothing model is a special case of ARIMA that has been extensively used for traffic data applications. Strictly speaking these models are just estimators of current conditions that are used as predictors. Although not discussed by Pan, The ALMAMC software uses a Kalman Filter in this manner to process lane specific information developed by the TMC from traffic detectors and other sources. 4 G. BOX and G. JENKINS, Time series analysis: Forecasting and control. San Francisco: Holden-Day, 1970 (book). B. Neural Network Models have been used for traffic prediction 5 as have genetic algorithms. 5 SHERIF ISHAK and CIPRIAN ALECSANDRU, Optimizing Traffic Prediction Performance of Neural Networks under Various Topological, Input, and Traffic Condition Settings, JTE'04, Volume 130. C. Historical Models—These models process historical data and provide prediction by reference to a future time period.
[0015] Pan concludes that he ARIMA/Exponential Smoothing models ae best for short term prediction (our interest) and that historical models are best for long term prediction. Pan provides an algorithm based on error characteristics to select between them.
SUMMARY OF THE INVENTION
[0016] The ALMAMC patent provides traffic speeds and other traffic variables according to a geographically related data structure described in the patent. The current patent replaces these current variables with predicted values when the prediction is estimated to be sufficiently accurate. Prediction periods are typically two minutes in duration, and typically predictions for three such periods may be provided, for a total prediction time of typically up to six minutes.
[0017] Prediction is provided in the current patent only when historic and current traffic conditions and estimated errors indicate that the prediction is likely to be accurate. When these conditions are not present, current traffic variables as provided by the processes in the ALMAMC patent are used.
[0018] The ALMAMC patent provides for filtering of the TMC traffic detector lane speed data. Occupancy and volume data if available are similarly processed. As an example, that patent describes the filter process using Kalman Filters. In ALMAMC, only the current values of these quantities are employed.
[0019] An example of the prediction methodology (ALMAPR) that may be used in the current patent and described in some detail is to use the predictive capability of Kalman Filters to predict the future lane based values of speed, volume and occupancy for the first prediction period and to extrapolate the rate of speed, volume and occupancy change into subsequent prediction periods. The estimate of the error in the current traffic variables is provided by the Kalman Filter and is used by the ALMAPR patent to assist in determining when the use of prediction is appropriate. Other data characteristics are also used for this purpose.
[0020] It is an object of the present invention to achieve, provide and facilitate Prediction for Lane Guidance Assist to supplement and/or replace modules in the ALMAMC and ALMAVM patents as follows:
Short term prediction of lane-specific traffic parameters including speed and others for providing guidance for the selection of a preferred lane and target speed for that lane; Such data is used by the ALMAVM module but may be used for other lane selection processes. Utilizing traffic management centers (TMCs), an ALMA Management Center and/or other information sources as possible data sources for the prediction model. Prediction traffic parameters may conform to a data structure described in the ALMAMC patent. Process checks may be performed for the quality of the predicted data; if the predicted data is not of sufficient quality, current data is substituted. Quality checks may include periods when changes in speed are high, data is erratic, estimation error is excessive and data that may be affected by traffic incidents. The predicted data may be an improvement over the current data because the predicted data is available in advance. Predictions are provided in prediction time intervals of appropriate duration. Provides average predicted lane speeds for vehicles or drivers for a look ahead (downstream) distance from the vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The features, aspects and advantages of the novel Prediction for Lane Guidance Assist will become further understood with reference to the following description and accompanying drawings where
[0028] FIG. 1 is the flowchart of the ALMA simplified data flow;
[0029] FIG. 2 is the graphical representation of Key Time Sequence Relationships;
[0030] FIG. 3 . Is ALMA Management Center Flow Chart for Additions Required by ALMAPR; and
[0031] FIG. 4 is Example of Look Ahead Time Development Process.
DESCRIPTION
[0032] Introduction. ALMA as described in U.S. Pat. Nos. 9,053,636 (ALMAMC) and 9,286,800 (ALMAVM) provides information to conventional and partly or fully automated vehicles to enable them to respond to freeway lane selection and target speed selection information originating from a freeway traffic management center in a way that is superior to the way that an unaided human driver or automated vehicle would respond to that information. The disclosures of these patents describe how speed, volume and occupancy information collected at a traffic management center (TMC) is processed by the ALMA Management Center (ALMAMC) and transmitted to the vehicle. Using this information in conjunction with routing, speed and location information supplied by the vehicle and information from the vehicle operator, the ALMA Vehicle Module (ALMAVM) recommends the most appropriate freeway lane and a target speed for that lane.
[0033] FIG. 2 of the existing ALMAMC patent illustrates the ALMA architecture. FIG. 1 shows a simplified view of this architecture. Using roadway traffic sensors or other means to detect individual vehicles, a traffic management center (TMC) 102 develops traffic data such as speed, volume and occupancy. TMCs also detect and manage traffic incidents and provide traffic information to motorists by means of roadway devices such as dynamic message signs (DMS) and other means. The ALMA traffic management center 103 further processes this information, organizes it and transforms it using a prescribed data structure as described in the ALMAMC patent. Processed traffic parameters suitable for the presentation of lane conditions and other information are the transmitted by means of a communication system 104 such as a smartphone with an appropriate vehicle head unit. This information is used by the ALMA Vehicle Module 107 in conjunction with vehicle position, speed and routing information from the vehicle 105 and driving preferences and other information from the motorist 106 to provide recommended lane and target speed information to the motorist display and/or the partially or fully automated vehicle management system 101 .
[0034] The ALMAMC patent also describes the geometric data structure to which the data is referenced. In summary, the freeway is divided into barrels and zones. A barrel represents a set of travel lanes in a roadway. It is physically or functionally separated from other parallel lane sets. Barrel boundaries are determined by changes in the physical roadway configuration and by permanent changes along the roadway in the regulatory use of the roadway or its lanes. A barrel is divided into zones. Zone boundaries are determined by a number of factors including traffic conditions, placement of motorist information devices and regulatory devices that provide changeable information.
[0035] The existing ALMAMC patent provides information based on its estimate of current traffic conditions. The current patent provides this information based on short term predictions of traffic conditions. This will improve performance under some traffic conditions. The geometric data structure of the ALMAMC patent is preserved in the current patent application.
[0036] The current ALMAPR patent application describes a set of modules that replace certain ALMAMC and ALMAVM modules when confidence in the prediction accuracy is high. These are described in the following sections. The ALMAMC modules to be replaced include five outputs in Table 3 of the ALMAMC patent. These are described in Appendix B. Appendix A identifies the symbols used in this patent. Essentially the new functions use the prediction feature of the Kalman Filter for the prediction period that follows the current period. An extrapolation process provides prediction for subsequent prediction periods.
[0037] For predictive purposes, the computation of the number of look-ahead zones and the look ahead speed is more complex that for Modules 4.3R.2.5 and 4.3R.2.6 of the ALMAVM patent. These modifications are described in subsequent sections of this patent.
[0038] Temporal Relationships. The current patent (ALMAPR) predicts traffic variables for several future time periods. FIG. 2 shows the relationship among the key time sequences employed. Horizontal axis D 204 is a time scale that relates the other horizontal axes to clock time.
[0039] The top horizontal axis (A) 201 represents the intervals (n) after the current interval for which the data is received by the ALMAMC from the TMC. It is represented as one half minute in the figure although some TMCs may provide different intervals. The second horizontal axis (B) 202 represents the periods (r) for which ALMAPR will predict the speed. The duration of these periods is shown as two minutes in the figure.
[0040] As will be subsequently described, ALMAPR employs historic traffic speed data. The third horizontal axis (C) 203 represents the time periods (j) for which the historic data is compiled from TMC data. Five minute intervals as shown are typically employed.
[0041] The current patent ALMAPR provides a major addition to the modules in the ALMAMC and ALMAVM patents. This addition provides:
The type of traffic parameter outputs shown in Table 3 of the ALMAMC patent in the form of predicted parameters. The current patent's outputs are shown in Appendix B. Modifications to the spatial-temporal data structure in the ALMAVM patent to enable the predicted traffic parameters to be effectively employed in the vehicle.
[0044] Example of Prediction Process. As described earlier, a number of prediction concepts may be used. An example of the prediction process, and the constraints on its use, is described in the following discussion with the assistance of FIG. 3 .
[0045] The speed data SPINT(Z,L,) from the TMC 301 is averaged into stored historic data reference periods (j) 203 .
[0046] In the Historic Speed Data process 302 , averages for the most recent K 3 days are obtained for each time period for weekdays, and weekend days. Exception days (days excluded from the averaging period) may be identified by the ALMAMC manager.
[0047] The historic data is processed for the purpose of eliminating Kalman prediction data 305 for periods that history has shown to be unsuitable. This includes:
Periods when changes in the speed in a zone averaged over all lanes exceed a threshold value (K 2 ) render Kalman prediction unsuitable 303 . Detector stations that frequently provide erratic data 304 . These stations can be identified when the total number of stored daily periods (j) for which the average zone speed change exceeds K 5 for representative days is greater than K 4 .
[0050] Similar to the process described for the ALMAMC patent the prediction process uses a Kalman Filter process 305 to estimate the current speed (SPFIL(Z,L,r)). See, for example Welch, G and T R Bishop, “An Introduction to the Kalman Filter”, University of North Carolina Department of Computer Science, TR 95-041, 2006.
[0051] The prediction process in this patent modifies the estimation process in the ALMAMC patent as follows. Prediction for the first prediction interval r 0 +1 205 and designated as SPFILPR(B,Z,L,r 0 +1) is available from the Kalman iteration that follows the estimate for the current interval. Prediction for subsequent prediction intervals (r>r 0 +1) will be performed by using the rate of change of speed for interval r+1 for the subsequent intervals. The rate of speed change is computed as
[0000] RSC =( SPFIL ( B,L,Z,r )− SPFIL ( B,L,Z,r− 1))/ LR
where LR is the duration of the prediction interval (r) The predicted speed when converted to space-mean-speed is designated as SPSPPR(B,Z,L) for all prediction intervals.
[0054] The estimation error for speed (SPE(L,Z,r)) for the current interval is used in module 307 .
[0055] Module 306 interprets incident related information from the TMC to identify the presence of an incident. The module identifies zones affected by the incident. This information is sent to Module 307 .
[0056] Under certain conditions the predicted value for speed may be unreliable. Module 307 substitutes the current value of zone speed (SPFILTOT(Z,r)) for each lane for the values for the prediction intervals when the following conditions are present:
Speed estimation error (SPE(L,Z,r) exceeds an acceptable threshold K6. Zone employs a detector station that provides erratic data ( 304 ). Zones affected by an incident have been identified ( 306 ).
[0060] As described in the ALMAMC patent, lane based data that originates from point detectors can be processed to provide key fundamental traffic parameters such as volume and occupancy (which may be further processed to provide density.) TMC data that originates from such sources as infrastructure based probes or vehicle based sensors working in conjunction with vehicle to infrastructure communications cannot be effectively processed in a similar manner because all of the necessary variables cannot be measured by these techniques. Module 308 controls the steps that implement this distinction.
[0061] If the TMC speed data originated from point detectors, Module 308 directs the computation to a path that will provide the additional parameters described in the ALMAMC patent (Module 6 and Table 3).
[0062] Module 309 converts the predicted time mean speed originating from point detectors to predicted space mean speed using the relationship shown in Equation 8 of the ALMAMC patent.
[0063] Predicted volume and occupancy 310 are computed by Kalman Filters in the prediction mode similar to that used to compute time mean speed. Predicted density 310 is computed using the relationships in Appendix B and predicted compensated occupancy 310 is computed using Equation 10 of the ALMAMC patent in conjunction with the prediction processes described for speed in the current patent.
[0064] The relationships required to compute the remaining parameters 311 (predicted average headway, predicted average vehicle length, predicted passenger car equivalent volume) identified in Table 3 of the ALMAMC patent are computed as shown in Appendix B.
[0065] When point detectors are used as the data source, the full parameter set is provided to the ALMAVM module in the vehicle 313 . When other types of information (such as probe based information) are used as the data source 312 , only predicted space mean speed is provided to the ALMAVM module 313 .
[0066] Spatial—Temporal Relationships. The prior discussion describes the additions to the ALMA Management Center required to support predictive capability. The following discussion describes additions and modifications to the ALMA Vehicle Module required to support prediction.
[0067] ALMAVM identifies the number of downstream zones that should be employed to estimate a “look ahead” speed (ALMAVM Module 4.3R.2.5). In that module, the look ahead speed is calculated as the current speed for each zone weighted by the length of each zone.
[0068] Where predicted speeds are used in place of current speeds, it becomes necessary to identify the appropriate time interval to be used for traversing each zone. An approach for doing this is described with the assistance of FIG. 4 . The solid line represents the time-space plot of a vehicle after it enters the first look ahead zone. The slope of each segment of the trace represents the average speed of the vehicle for that zone and prediction interval. This slope changes as the vehicle traverses each zone in the look ahead distance. The first segment shown in the FIG. 401 uses the speed for Zone Z+1 for the current time interval. The line segment 402 for the first prediction interval (r+1) lies entirely within zone Z+1. Table 1 shows the predicted speed to be used for each trace segment to fully develop a similar figure for each vehicle. In this way each line segment serves as the base for the next line segment when this process is completed, the value for look ahead time (LAT(L)) is obtained.
[0000]
TABLE 1
Predicted Speed for Vehicle
Look ahead zones
Time interval
Z + 1
Z + 2
Z + 3
Current interval r 0
Slope of
segment 401
Prediction Interval r 0 + 1
Slope of
segment 402
Prediction Interval r 0 + 2
Slope of
Slope of
Slope of
segment 403
segment 404
segment 405
Prediction Interval r 0 + 3
Slope of
segment 406
[0069] These concepts will be used to replace Module 4.3R.2.6 in the GAVM program. In that module ZWAS(L) represents the look ahead speed for each lane using current zone speeds. The predictive replacement is provided by the expression:
[0000] ZPWAS ( L )= DLA/LAT ( L ) where DLA is the look ahead distance 407 shown in FIG. 4 and LAT(L) is the look ahead time 408 for lane L.
APPENDIX A
[0071]
[0000]
Definition of Symbols
Symbol
Definition
AHWPR(B, Z, L)
Predicted average headway
AVL
Average vehicle length
d
Detection zone
DENFILPR (B, Z, L)
Predicted lane density
DLA
Look ahead distance
F
Scaling coefficient
j
Stored historical period
K2
Threshold for excessive changes in speed
K3
Number of averaging days
K4
Limit on number of prediction intervals for
which speed change is unsuitable
K5
Threshold for speed change unsuitability
K6
Acceptable estimated error for speed
LAT(L)
Predicted look ahead time
LL
Length of detector sensing area in lane
LR
Duration of prediction interval
NOPREDDAYCLASS(d)
Detection zones to be eliminated because of
erratic data
OCCFILPR (Det, L)
Predicted occupancy
PCE
Passenger car equivalent volume
PCEPR (B, L, Z)
Predicted passenger car equivalent volume
r
Computation and prediction interval
r 0
Current interval
RSC
Rate of speed change
SPE(L, Z, r)
Estimated error in speed
SPFIL(L, Z, r)
Kalman filtered lane speed
SPFILTOT(Z, r)
Filtered speed for all through lanes in zone
SPINT(Z, L)
Speed by lane from TMC
SPSPPR(B, Z, L)
Predicted lane speed
VOLFIL(BZL)
Filtered detector volume in TMC reference
VOLFILPR(B, Z, L)
Predicted lane volume
Z
Zone
ZPWAS(L)
Predicted look ahead speed
ZWAS(L)
Look ahead speed using current speed
APPENDIX B
ALMAPR Output Parameters
[0072] When appropriate as described in this patent the parameters shown inn Table B1 are provided using the equations that follow the table. The background for these equations is the same as that provided for Equations 8, 9, 18, 19 and 20 in the ALMAMC patent. Symbol definitions are provided in Appendix A.
[0000]
TABLE B1
ALMAPR output parameters from the ALMA Management Center
Detectors with Accurate
Volume and Speed Data (may
Detectors with Accurate
or May Not Include Accurate
Traffic Parameter
Volume and Occupancy Data
Occupancy Data)
Predicted Lane Volume
VOLFILPR(B, Z, L)—Volume
VOLFILPR(B, Z, L)—Volume
(vehicles/hr)
prediction process output
prediction process output
converted to ALMA data
converted to ALMA data
structure
structure
Predicted Average Headway
AHWPR(B, Z, L) =
AHWPR(B, Z, L) =
(hours/vehicle)
1/VOLFILPR(B, Z, L) converted
1/VOLFILPR(B, Z, L) converted
to ALMA data structure
to ALMA data structure
Predicted Passenger Car
PCEPR (B, L, Z)—Equation
PCEPR (B, L, Z)—Equation
Equivalent Volume
B1 converted to ALMA data
B1 converted to ALMA data
structure
structure
Predicted Lane Speed
SPSPPR(B, Z, L)—Equation
SPSPPR(B, Z, L)—Speed
B3 converted to ALMA data
prediction process (307, 308,
structure
309) converted to ALMA data
structure
Predicted Lane Density
DENFILPR (B, Z, L)—Equation
DENFILPR (B, Z, L)—Equation
B4 converted to ALMA data
B2
structure
Equations
[0073] PCEPR ( Det,L )= PCE*VOLFILPR ( B,Z,L )/ VOLFIL ( B,Z,L ) B1
[0000] DENFILPR ( B,Z,L )= VOLFILPR ( B,Z,L )/ SPSPPR ( B,Z,L ) B2
[0000] SPSPPR ( B,Z,L )= VOLFILPR ( B,Z,L )/ DENFILPR ( B,Z,L ) B3
[0000] DENFILPR ( Det,L )=( F*OCCFILPR ( Det,L ))/( LL+AVL ( Det,L )) B4 | The automated lane management assist method, data structure and system receive unprocessed lane-specific limited-access highway information, including lane use and speed limits, from traffic detectors in the roadway or from other sources, process and develop predicted information from these sources and substitute the predicted information for the current information where appropriate, thus improving the timeliness of the information in a form that assists in the selection of driving lanes and target speeds for vehicles, including in partially and fully automated vehicles, and communicate the processed predicted information to the vehicles by suitable means. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a National Stage of International Application No. PCT/EP2004/011484, filed Oct. 13, 2004, and which claims priority to German Patent Application No. 103 53 046.0, filed Nov. 13, 2003. The disclosures of these applications are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a refrigerating apparatus, in particular for the cooling of refrigerating spaces, comprising two alternately activatable heat exchangers, in particular evaporators or coolers of a coolant circuit, and at least one fan to blow gas, in particular air, through the heat exchanger.
BACKGROUND OF THE INVENTION
[0003] A refrigerating apparatus of the initially named kind is known from DE 197 09 176 C2. With this refrigerating apparatus, the two alternately activatable heat exchangers made with lamellae are arranged next to one another or over one another and are flowed through by the same flow of the medium to be cooled. This means that the two heat exchangers are each only charged by half of the flow. To achieve a desired charge with a medium flow, the total flow must therefore be selected to be twice as large. The fan must be made correspondingly large, whereby the costs and the space requirements are increased.
SUMMARY OF THE INVENTION
[0004] It is the underlying object of the invention to provide a refrigerating apparatus of the initially named kind which does not have these disadvantages. The refrigerating apparatus should in particular be cost favorable and space saving.
[0005] This object is satisfied in that the heat exchangers are arranged such that they can each be flowed through by the total gas flow of the fan at least on activation.
[0006] By the arrangement of the heat exchangers such that they can each be flowed through by the total gas flow of the fan, the required total gas flow can be reduced to approximately half with respect to the known apparatus. The fan must accordingly be dimensioned smaller, whereby costs and space are saved.
[0007] A flowing through of both heat exchangers by the total gas flow can in particular be achieved in that the two heat exchangers are arranged behind one another in the direction of flow. In this process, both heat exchangers can be arranged on the same side of the fan. Both heat exchangers are thereby automatically charged with the total gas flow, irrespective of the direction in which the fan blows.
[0008] Another arrangement consists of a first heat exchanger being arranged before the fan or fans in the direction of flow and a second heat exchanger being arranged behind the fan or fans in the direction of flow. The two heat exchangers can thereby protect the fan from external influences.
[0009] A design is particularly cost favorable in which the heat exchangers are arranged freely in front of or behind the fan or fans. No additional components are thereby necessary and conventional heat exchangers can be used. Special products as with the initially named refrigerating apparatus are not necessary.
[0010] Gas conducting passages can, however, also be arranged between the fan or fans and the heat exchangers. A plurality of advantages hereby result. The heat exchangers and the fan can inter alia be arranged spaced from one another. In addition, pressure measuring devices such as pressure gages, filters or attenuators can be arranged in the gas conducting passages.
[0011] In accordance with a further embodiment of the invention, the fan or fans and the heat exchangers are also arranged in closed gas conductors. The flow generated by the fan can thereby be fully utilized and a good flow guidance can be achieved.
[0012] It is particularly preferred for the fan or fans and the heat exchangers to be arranged in a common housing. This is space saving, on the one hand, and also effects a good protection of the fan or fans by the heat exchangers exchanged in front and/or behind them.
[0013] Gas conducting passages can preferably be connectable to the housing at least at the gas outlet side. This advantageously permits the remote installation of the housing from the location to be cooled, for example in the false ceiling of a refrigerating space or completely outside a building surrounding the refrigerating space.
[0014] In accordance with a particular embodiment of the invention, a fan with a reversible blowing direction is provided. By reversing the blowing direction of the fan, the direction of flow of the gas through the heat exchangers arranged in front of or behind the fan can be reversed, in particular such that the gas is sucked in by the respectively non-active heat exchanger and blown out by the respectively active heat exchanger. The non-active heat exchanger is thus flowed through by the gas to be cooled and is heated by it, which can advantageously be used for defrosting with evaporators of a coolant circuit when the temperature of the gas to be cooled is above freezing point. Subsequently, the gas thereby already cooled passes through the activated second heat exchanger, with it being further cooled in the desired manner.
[0015] One heat exchanger can thus always be defrosted and one used for cooling by an alternate activation of the two heat exchangers and a corresponding reversal of the blowing direction of the fan. This also has the advantage that the blowing out direction of the unit changes cyclically, whereby a better distribution of the cooled gas in the refrigerating space can be achieved. If, in contrast, a blowing out should always only be desired in one direction, this can be achieved by a suitable arrangement of gas conducting passages and valves in front of the outlets or inlets of the refrigerating apparatus.
[0016] In accordance with another embodiment, the different throughflow direction of the heat exchangers is realized by valve-controlled fluid guides.
[0017] With this embodiment, the gas can also be alternately sucked in by the one heat exchanger and blown out by the other heat exchanger, with the one heat exchanger respectively being inactive and optionally defrosted, whereas the other heat exchanger is activated for cooling. A reversal of the blowing direction is not necessary with this arrangement. A further advantage consists of the fact that the fan power can be optimized for the only blowing direction of the fan.
[0018] In accordance with a special embodiment of the invention, a fan is provided whose blowing side can alternately be connected via switch-over valves and corresponding gas conducting passages to the first heat exchanger or the second heat exchanger and its suction side to the respectively other heat exchanger. With this variant, the fan is therefore arranged between the two heat exchangers.
[0019] In accordance with another special embodiment, a fan is provided whose suction side is connected to the entry opening of the apparatus and whose blowing side is alternately connected to the first heat exchanger or to the second heat exchanger, with the respectively other heat exchanger being connected to the one heat exchanger, on the one hand, and to the outlet opening of the apparatus, on the other hand. In this variant, both heat exchangers are accordingly arranged in front of the fan or both heat exchangers are arranged behind the fan in the direction of flow.
[0020] In accordance with yet another special embodiment of the invention, two fans are provided which are arranged in opposite senses and parallel to one another and are each connected to the two heat exchangers via gas conducting passages and can be activated alternately. It can again also thereby be achieved that the gas to be cooled is alternately sucked in by the one heat exchanger and blown out by the other heat exchanger. In this process, one fan is active and the other fan is inactive respectively. The advantage is also present here that the fan power can be optimized for the only direction of flow.
[0021] The respectively non-active branch of this arrangement can preferably be closed via a valve. A false flow through the non-active branch can thereby be avoided.
[0022] In accordance with a particularly preferred embodiment of the invention, the inlet opening and the outlet opening of the apparatus are formed in each case by the same opening irrespective of the throughflow direction of the heat exchangers. The advantage thereby results that a filter attached behind the inlet opening is always flowed through in the same direction. No exchangeable filters therefore have to be provided, which permits a particularly good sealing of the filters. False air can hereby largely be avoided so that a high filter performance up to clean room engineering can be ensured.
[0023] It is likewise preferred for the inlet opening and the outlet opening of the housing always to be arranged at the same side of the apparatus, in particular next to one another. A particularly compact design of the apparatus can thereby be achieved, whereby the space requirements can advantageously be reduced.
[0024] A further reduction in the space requirements can be achieved in that the fluid guides extend in different planes at least sectionally, in particular above one another and beneath one another, in accordance with a further embodiment of the invention. In addition, this variant is particularly advantageous when the inlet opening and the outlet opening are arranged on the same side of the apparatus.
[0025] It is furthermore advantageous for the diameter of the fluid guides to differ in different sections. The diameter can in particular be larger in the region of the heat exchangers than in front or behind them, for example in a ratio of approximately 2:1. The construction size can thus also be further reduced, without the performance capability of the apparatus being noticeably restricted since the cross-section can be kept advantageously large in the region of the heat exchangers and the reduced cross-section in another respect means hardly any impairment.
[0026] Axial fans can be used as fans in the refrigerating apparatus in accordance with the invention. However, radial fans can preferably also be used in the refrigerating apparatus in accordance with the invention. The latter have the advantage of a considerably higher pressing, which in particular comes into effect with the use of gas conducting passages.
[0027] The use of radial fans also permits the use of filters for the gas to be cooled. They can in particular be arranged in the gas conducting passages and/or in the fan housing. High hygiene demands can be satisfied by the use of filters.
[0028] In particular at least one rotary filter can be provided as the filter which is rotatable in dependence on the direction of flow of the gas. In this manner, the filter is always charged in the same direction by the gas flow. A blowing out of filtered particles again can thereby be avoided.
[0029] In accordance with a further embodiment of the invention, at least one roll filter is provided. The latter can, for example, be made as a disposable filter and can be further rotated accordingly on every reversal of the direction of flow.
[0030] In accordance with another embodiment of the invention, the filter roll can, however, also be made to be movable to and fro in a cyclic manner in dependence on the direction of flow of the gas. A respective section of the filter roll is thereby always charged with the gas flow in the same direction so that the blowing out of particles again can also be avoided here. On the reaching of a specific degree of load of the filter, the roll can then be rotated further by twice the filter length so that two new sections of the roll filter can be used alternately.
[0031] At least one pressure measuring device, in particular a pressure gage, can be arranged in the gas conducting passages and/or in the fan housing. It can be used both for the determination of the degree of icing of the heat exchangers and for the determination of the necessity of a change of filter.
[0032] A change of filter or a further rotation of a roll filter can, however, also be triggered or indicated at the end of a predetermined or predeterminable time, for which purpose corresponding means are provided in accordance with a further embodiment of the invention. A pressure measuring device can thereby be saved. Good results can nevertheless be achieved on the basis of experience values.
[0033] The reversal of the direction of flow through the two heat exchangers can also take place in dependence on time, for which purpose suitable means are likewise preferably provided. Good results can also thereby be achieved on the basis of experience values and corresponding measuring devices such as pressure measuring devices for the detection of the degree of icing of the heat exchangers can be saved.
[0034] In accordance with a further embodiment of the invention, means for sterilization are provided in the gas conducting passages and/or in the fan housing, in particular in the region of the outlet opening. Hygienic demands can also thereby be satisfied, with the sterilization being particularly effective in the outlet region.
[0035] Means for UV irradiation or ionization can preferably be provided for the sterilization. Alternatively or additionally, it is also possible to provide means for the injection of disinfectants, for example fruit acid. Both measures are well suited for sterilization.
[0036] The two heat exchangers are generally operated alternately. In accordance with an embodiment of the invention, however, an overlapping operation is also possible by a corresponding control for the activation of the heat exchangers. An increased refrigerating capacity can be made available in the short term by such a control. The air humidity can additionally thereby be regulated.
[0037] Furthermore, sound attenuation devices in the fan housing or in the gas guides are advantageous. The noise radiation of the apparatus can thereby be reduced.
[0038] The speed of rotation of the fan or fans can advantageously be regulated for the regulation of the capacity of the refrigerating apparatus in accordance with a further embodiment.
[0039] An advantageous design results when the housing has a plurality of chambers. It is advantageous for service and repair purposes in this process if the chambers are each accessible via their own access opening, in particular a door.
[0040] It is furthermore advantageous for each chamber to have its own condensate drain. Service and repair measures can also be simplified in that a lighting device is provided in the housing.
[0041] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Non-restricting embodiments of the invention are shown in the drawings and will be described in the following. There are shown, schematically in each case:
[0043] FIG. 1 a block diagram of a first variant of the refrigerating apparatus in accordance with the invention;
[0044] FIG. 2 a representation in accordance with FIG. 1 of a second variant;
[0045] FIG. 3 a representation in accordance with FIG. 1 of a third variant;
[0046] FIG. 4 an upper view of a fourth variant of the refrigerating apparatus in accordance with the invention;
[0047] FIG. 5 a perspective view of the variant of FIG. 4 from a first direction of view; and
[0048] FIG. 6 a perspective view of the same apparatus from a second direction of view.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0049] The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0050] FIG. 1 shows a fan 1 , two heat exchangers 2 arranged at both sides of the fan 1 as well as two filters 3 arranged in each case on the side of the two heat exchangers 2 remote from the fan 1 . Gas guides 4 are present between the fan 1 and the heat exchangers 2 and the filters 3 , with these being able to consist of passages or lines. The fan 1 and the heat exchangers 2 as well as preferably also the filters 3 can, however, also be arranged in a common housing which then ensures the schematically shown gas guidance between the named components.
[0051] In addition, two pressure gages 5 are shown via which the pressure can be detected on both sides of the fan 1 . A pressure gage 5 of this type can be arranged both in the region of the filters 3 , as shown, to be able to draw a conclusion on the degree of load of the filters 3 , and in the region of the heat exchangers 2 to be able to draw a conclusion on their degree of icing. To be able to detect both, a plurality of pressure gages 5 can also be provided on each side.
[0052] The fan 1 is made as a radial blower whose direction of rotation can be reversed. In this manner, a gas flow can be generated both in the direction of the arrow 6 and in the reverse direction in accordance with arrow 7 . The switch-over can take place in dependence on the degree of icing of the heat exchangers 2 or in dependence on time. A corresponding control is provided, but not shown.
[0053] The filters 3 can be made as rotary filters, in particular as bag filters rotatable around 180°. The rotary position can be set according to the blowing direction of the fan 1 via a suitable control so that the filters are always charged by the gas flow 6 or 7 in the same direction and the particles absorbed by the filters 3 are not blown out again when the direction of rotation of the fan 1 reverses. The filter 3 on the outflow side could, however, also simply be moved out of the flow since it is often sufficient for the filter 3 on the suction side to be active.
[0054] Roll filters with which filter material can be wound off a roll can also be used instead of bag filters. If the roll filter is made as a disposable filter, it is respectively wound off the roll by a corresponding length on the reversal of direction of the fan 1 . However, a multifilter can also be used with which the control winds the filter on and off cyclically so that always the same section of the filter is active in the one and the other blowing direction 6 , 7 of the fan 1 . The control can furthermore be made such that on a specific degree of loading of the filter the roll is further rotated so far that two new sections are available for the rolling onto and off the roll.
[0055] The necessity of a change of filter or of a further rotation of a roll filter can be detected via a suitable control in dependence on the pressure. The control can indicated this and/or initiate an automatic change or an automatic further rotation of the filter.
[0056] The necessity of a filter change can, however, also be detected by the passing of time instead of via the pressure. The time span in particular results from experience values and can be preset. The time span can, however, also be changeable and be predetermined by the user.
[0057] The heat exchangers 2 can be made with lamellae as is described, for example, in DE 19709 176 C2. In another respect, conventional heat exchangers can, however, also be used such as are also used for simple fans blowing only in one direction. Conventional fans of this type can also be used for the fan 1 .
[0058] In the variant shown in FIG. 2 , the direction of rotation of the fan 1 is not reversible. Instead, the fan 1 is respectively connected to the two heat exchangers 2 via two alternative paths 4 a , 4 b and 4 c , 4 d . In each of these four sections 4 a , 4 b , 4 c , 4 d , a closing valve 8 is arranged which is opened or closed depending on the desired direction of flow of the gas flow 6 or 7 .
[0059] To effect a flow in accordance with the arrows 6 , the valves 8 in the sections 4 a and 4 d are open and those in sections 4 b and 4 c are closed. Accordingly, to effect a flow in accordance with the arrows 7 , the valves 8 in the sections 4 b and 4 c are open and those in sections 4 a and 4 d are closed. The fan 1 is here also preferably made as a radial blower, with it now, however, being able to be optimized better due to the single direction of rotation. In other respects, the design of this variant can be identical to the one previously described. The mode of operation is also identical with the exception of the switching over of the valves 8 .
[0060] In the variant shown in FIG. 3 , two fans 1 a and 1 b are provided which are arranged parallel to one another and with opposite directions of rotation in a respective part section 4 e , 4 f of the gas guide 4 . The one fan 1 a or the other fan 1 b is switched on in dependence on the desired direction of flow 6 or 7 . A flow is in particular generated in the direction of arrow 6 by switching on the fan 1 a and closing the section 4 f and a flow in the direction of arrow 7 by switching on the fan 1 b and closing the section 4 e . The respective section 4 e or 4 f with the non-active fan 1 a or 1 b is closed via closing valves 9 in the two sections 4 e and 4 f to avoid a false flow.
[0061] The two fans 1 a and 1 b are in turn preferably made as radial fans and are optimized for their respective direction of flow. In other respects, the apparatus can also be made in the same manner as with variant 1 here. The operating mode is also identical to that of variant 1 with the exception of the alternate activation of the two fans 1 a and 1 b and the closing of the respectively other section 4 f or 4 e.
[0062] The variant shown in FIGS. 4 to 6 includes a housing 10 with an inlet opening 11 and an outlet opening 12 . A filter 3 is arranged behind the inlet opening 11 and behind it a fan 1 not reversible in its direction of rotation. The suction side of the fan 1 faces the inlet opening 11 of the housing 10 . The blowing side of the housing 1 is adjoined by a valve 13 and behind this the two heat exchangers 2 .
[0063] The housing 10 is divided by a partition wall 14 into two regions 15 and 16 which are in turn divided into a plurality of chambers 18 by partition walls 17 . The filter 3 is arranged in a first chamber 18 1 behind the inlet opening 11 of the housing 10 . It is followed by a chamber 18 2 which is separated from the first chamber by a partition wall 17 1 . The partition wall 17 1 has a passage opening 19 to which the suction side of the fan 1 is connected.
[0064] The chamber 18 2 with the fan 1 is bounded on the other side by a partition wall 17 2 in which the valve 13 is provided. As can in particular be recognized in FIG. 5 , the height of the valve 13 amounts approximately to half the height of the partition wall 17 2 .
[0065] The partition wall 17 2 bounds a further chamber 18 3 with the first heat exchanger 2 1 ; the first heat exchanger 2 1 a chamber 18 4 with the second heat exchanger 2 2 ; and the second heat exchanger 2 2 a further chamber 18 5 with the housing 10 . All chambers 18 1 to 18 5 are located in the first housing section 15 .
[0066] As can in particular be recognized in FIG. 6 , a chamber 18 6 and a chamber 18 7 are formed in the second housing section 16 by a two-fold angled partition wall 17 3 . The chamber 18 6 is connected to the chamber 18 5 via an opening 20 . A further connection of the chamber 18 6 is present via a valve 21 to the chamber 18 2 in which the fan 1 is located. The chamber 18 7 is connected to the chamber 18 3 via a further valve 22 and to the chamber 18 6 via a further valve 26 .
[0067] The angled partition wall 17 3 has a first vertical section 23 which is connected to the upper side of the housing 10 , a horizontal section 24 adjoining it and a second vertical section 25 which adjoins the latter and is connected to the base of the housing 10 . The height h 1 of the second vertical section is approximately half the size of the height h 2 of the first vertical section. In addition, the further valve 26 is provided in the second vertical section 25 .
[0068] All the chambers 18 of the housing 10 are provided with their own condensate drain as is indicated by jagged arrows 27 . In addition, the chambers are accessible, in particular for maintenance and repair work, via doors 28 . Furthermore a UV radiation device 29 is provided in the chamber 18 6 and the medium guided through the apparatus can be sterilized by it. Finally, a lighting can be provided in the housing 10 .
[0069] In the variant shown in FIGS. 4 to 6 , the inlet opening is always formed independently of the throughflow direction of the two heat exchangers 2 1 and 2 2 by the opening 11 and the outlet opening is always formed by the opening 12 of the housing 10 . To nevertheless permit a changing throughflow of the two heat exchangers 2 1 and 2 2 , the valves 17 , 21 , 22 and 26 are provided. The valves 17 and 26 are open, the valves 21 and 22 closed, in contrast, for the throughflow of the apparatus in the first direction marked by the arrow 6 . The gas flow sucked in through the fan 1 moves from the inlet opening 11 via the filter 3 into the chamber 18 1 and from there into the chamber 18 2 . Then the gas flow moves through the valve 13 into the chamber 18 3 , flows through the first heat exchanger 2 1 , which is inactive in this case and is defrosted by the warm gas flow, then into the chamber 18 5 , then through the active heat exchanger 2 2 by which the gas flow is cooled and then into the chamber 18 5 . From there, the gas flow moves via the opening 20 in the wall 14 into the chamber 18 6 in which the gas flow is sterilized by the UV radiation device 29 . The gas flow then flows through the valve 26 , moves into the chamber 18 7 and moves from there via the outlet opening 12 out of the housing 10 of the apparatus.
[0070] On the reverse operation of the apparatus in accordance with arrow 7 , the valves 17 and 26 are closed, whereas the valves 21 and 22 are open. The gas flow sucked in by the fan 1 now no longer moves from the chamber 18 2 into the chamber 18 3 since the valve 13 is closed, but rather via the valve 21 into the chamber 18 6 . From there, the gas flows on through the opening 20 in the wall 14 into the chamber 18 5 , flows through the second, now inactive heat exchanger 2 2 , with this being defrosted, further into the chamber 18 4 , then through the first, now active heat exchanger 2 1 which cools the gas flow and then into the chamber 18 3 . Since the valve 13 is closed, the gas flow moves from the chamber 18 3 via the valve 22 into the chamber 18 7 and flows out from there via the outlet opening 12 of the housing 10 . The gas is also sterilized by the UV radiation device 29 in the chamber 18 6 in this operating direction. Instead of the arrangement of the radiation device in chamber 18 6 , it can also be arranged in chamber 18 7 , that is in the region of the outlet opening 12 .
[0071] As can be recognized, the two heat exchangers 2 1 and 2 2 can selectively be flowed through in the one or the other direction 6 , 7 in accordance with the operating mode described. A large cross-section of the heat exchangers and, on the other hand, a relatively low housing size overall is realized by the ratio of the housing section 15 to the housing section 16 of approximately 2:1. The cross-section changes thereby occurring have no disadvantageous influence on the flow.
[0072] In all the variants shown, both heat exchangers 2 , which can in particular be the evaporator or cooler of a coolant circuit, are flowed through by the total gas flow of the fan 1 or of the fans 1 a , 1 b . This means that gas is sucked in by the one heat exchanger 2 , which is then not activated, and is blown out by the other heat exchanger 2 , which is activated. If the first heat exchanger 2 is iced, the sucked in gas is already cooled. With gas having a temperature above freezing point, the first heat exchanger 2 is thereby defrosted without any electrical or other defrosting equipment being necessary. The gas is further cooled in the desired manner in the active, second heat exchanger.
[0073] After reaching a specific degree of icing of the second heat exchanger 2 or after a predetermined extent of time, the flow direction is switched over in that, in the case of the variant of FIG. 1 , the direction of rotation of the fan 1 is switched over. In the case of the variant of FIG. 2 , the valves 8 are switched over for this purpose from their open position into their closed position and from their closed position into their open position. And in the case of the variant of FIG. 3 , when the fan 1 a was first switched on, it is switched off and the other fan 1 b is switched on and the closed valve 9 is opened and the open valve 9 is closed. If, on the other hand, the fan 1 b was switched on, the switch-over takes place in reverse accordingly. The switching over in the variant of FIGS. 4 to 6 has already been described above.
[0074] In all cases, an overlapping operation is also possible in which both heat exchangers 2 are active for a specific period of time. The refrigerating capacity can thereby be increased in the short term, on the one hand, and the humidity content of the gas can thereby be regulated, on the other hand.
[0075] Filters 3 , gas conducting passages 4 and also noise attenuation devices can be used due to the use of a radial fan with which a much higher pressing can be realized than with an axial fan. The noise of the refrigerating device can thereby be advantageously reduced.
[0076] In addition, means can be provided in the fan housing for sterilization, such as UV radiation, and means for the injection of disinfectant, such as fruit acid.
[0077] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | Disclosed is a cooling device, especially for chilling cooling chambers, comprising two alternately activatable heat exchangers, particularly evaporators or coolers of a cooling circuit, and at least one fan for blowing gas, above all air, through the heat exchangers. In order to reduce production costs and space requirements, the two heat exchangers are disposed so as to be respectively penetrable by the entire gas flow of the fan at least when activated. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to compositions for golf balls. More specifically, the invention relates to an improved wound golf ball construction having high specific gravity thread windings so as to provide increased moment of inertia and improved trajectory distance.
[0003] 2. Description of the Related Art
[0004] As is well known in the industry, there are a number of different types of golf balls of which the predominant varieties are two-piece and three-piece golf balls. A two-piece or solid golf ball typically consists of a core and a cover. A three-piece ball typically consists of a center, an intermediate layer, which may be solid or comprise one or more elastomeric thread windings, and a cover. A ball with a solid intermediate layer is known as a multi-layered ball, while a ball with thread windings is referred to as a wound ball. In a three-piece configuration, the center and intermediate layer are collectively known as the core. In the three-piece golf ball configurations, the center is usually made of natural or synthetic rubber and may be either solid or have a liquid/paste form. The cover can be constructed from Balata, ionomer-based compounds, urethane compounds or any suitable thermoplastic or thermosetting material.
[0005] One of the parameters of golf ball performance that receives great attention is flight distance. Although there are a variety of factors that influence a golf ball's flight distance, perhaps the most important factors are the resilience characteristics and moment of inertia of the ball, both of which are dictated in large part by the materials used to construct the golf ball.
[0006] In general, solid golf balls have a higher moment of inertia in comparison to wound golf balls. This is due to the fact that the intermediate layer of a wound ball located between the center and cover has the lowest specific gravity or density. This is attributed to the material used in the thread windings (typically polyisoprene rubber) and to the inherent voids formed between said windings when stretched and wound over the center. Golf balls with a higher moment of inertia will exhibit a lower spin rate at launch; also, the decay of spin during flight is lower. Taken in combination, a lower spin rate at launch along with a decreased decay in that respective spin rate will increase the overall distance that a golf ball can travel.
[0007] The resilience of a golf ball also affects the distance it will travel, although not to the same degree as the moment of inertia. Hence, wound golf balls, which exhibit much higher resilience characteristics in comparison to their solid counterparts, will not achieve the same distance due to their lower moment of inertia. However, if the moment of inertia of a wound ball is increased to that of a solid ball, the wound ball would travel further than the solid ball due to the higher resilience of the wound ball. While a wound golf ball provides a golfer with better controllability and feel characteristics, it lacks a high moment of inertia and thus is unable to provide the extra distance.
[0008] For the foregoing reasons, it is desirable to produce a wound golf ball with a higher moment of inertia to improve the trajectory distance that the ball travel, without affecting the wound ball's inherent resilience, controllability and feel characteristics.
SUMMARY OF THE INVENTION
[0009] The present invention is directed towards a wound golf ball with an increased moment of inertia to improve the trajectory distance that the ball travels, without affecting the wound ball's inherent resilience, controllability and feel characteristics. A wound golf ball having features of the present invention comprises a center, the center being either a solid rubber or fluid-filled center, an intermediate layer comprising one or more elastomeric thread windings disposed over the center forming a core, and an outer cover disposed over the core having a plurality of dimples. To increase the overall distance that the ball will travel, the moment of inertia of the ball is increased by shifting the weight from the center towards the periphery of the ball. The weight shifting is accomplished by increasing the specific gravity of the thread to a value greater than 0.94, more particularly 0.96 and greater, even more particularly 1.00 and greater, and still even more particularly 1.2 and greater. This is accomplished by (and not necessarily in this order): (1) lowering the specific gravity of the center via the removal of the center's weight enhancing materials; and (2) by substituting conventional thread materials with materials having a specific gravity value greater than 0.94, more particularly 0.96 and greater, even more particularly 1.00 and greater, and still even more particularly 1.2 and greater and/or by adding high specific gravity fillers such as tungsten powder to the thread compound. By utilizing a high specific gravity material, desirable resilience and modulus characteristics inherent in a golf ball thread and windings are not compromised.
BRIEF DESCRIPTION OF THE DRAWING
[0010] These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and the accompanying drawing which is given by way of illustration only, and thus is not limitative of the present invention and wherein:
[0011] The sole FIGURE of the drawing shows a cross section of a wound golf ball according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Referring to the drawing, attention is drawn to a wound golf ball comprising a thread winding layer 1 , which may be a thermoset or thermoplastic elastomer (TPE) formed of conventional materials known in the art such as natural rubber and/or polyisoprene, other elastomers such as TPEs, polyurethane, latex etc., or any known material having a specific gravity greater than 0.94, more particularly 0.96 and greater, even more particularly 1.00 and greater, and still even more particularly 1.2 and greater. This layer is disposed over a solid or liquid-filled center 3 forming a core 5 . The core 5 is enshrouded by a cover 7 , which may be thermoplastic or a thermoset formed of conventional materials known in the art such as Balata and/or synthetic rubber, ionomer resins, polyurethane, thermoplastic elastomers (TPEs) or a combination of the foregoing. The cover 7 is either a single or multi-layered construction having a plurality of dimples (not shown) on its outermost surface. The center can be of two types, solid or liquid. The liquid center is one where liquid or gel is held in a rubber bag or shell that is well known in the art. The solid center is made from a combination of polybutadiene rubber, natural and/or polyisoprene rubber, zinc acrylate salt with weight enhancing materials and curatives. In a preferred embodiment, the center is made of a rubber composition comprising: 80-100 PPHR (parts per 100 parts by weight of the rubber in the composition) of any polybutadiene, 0-20 PPHR of natural, polyisoprene or other synthetic rubber or thermoplastic, 10-30 PPHR of zinc acrylate salt, 0-50 PPHR of weight enhancing materials (fillers), and 0.5-5 PPHR of curatives. The weight enhancing materials or fillers used are selected on the basis of specific gravity. In a preferred embodiment, the filler should have a specific gravity of about 4.3 or greater. Zinc oxide, barium sulfate, tungsten etc., and their mixtures thereof are examples of suitable fillers.
[0013] The curatives used in forming the golf ball center can be any of a variety of peroxides. The most important characteristic of the peroxide is its decomposition rate expressed by its half-life (t.sub.½). The half-life is the time required for one half of the molecules of a given amount of peroxide (or its blend) at a certain temperature to decompose. The peroxide (or its blend) that would work in the present system is one that has about a “one hour” half-life between 70 and 155° C. 1,1-Di-(tert-butylperoxy) -3,3,5-trimethyl-cyclohexane has a one-hour half-life between 105 and 115° C. Dialkyl peroxides, diacyl peroxides, peroxyesters and peroxyketals, alone or in combination, can be used as the curing agent to produce a golf ball center having the desired physical properties. As set forth above, 1,1-Di-(tert-butylperoxy)-3,3,5-trimethyl-cyclohexane, a peroxyketal, is the preferred curing agent. Furthermore, a sulfur based cure system may also be employed (if necessary) to achieve the desired center properties. The sulfur based cure system is selected from the group consisting of elemental sulfur, chemical accelerators and blends thereof.
[0014] The center is manufactured by using conventional compression molding processes. The components are mixed together in an internal mixer or any other suitable rubber mixing equipment and extruded to form preforms if necessary, which are then placed in cavities in a mold and compressed or transfer molded under pressure and temperature and cured/vulcanized to form centers. Preforms are necessary only if a compression molding technique is employed. The same mix may also be injection molded. Curing is carried out in the mold at temperatures in the approximate range of about 280-380° F. for 1-20 minutes depending on the compound and the process used.
[0015] The thread winding layer 1 is formed of any suitable elastomer thread material, such as natural or polyisoprene or any synthetic thermoset rubber or TPE and their combinations thereof, that is stretched and wound about the center 3 as is conventional in the art.
[0016] To increase the flight distance of a conventional wound ball in accordance with the present invention, the moment of inertia is increased. Increasing the moment of inertia reduces the overall rate of spin at launch and reduces the decay of spin during flight. This reduction in the spin rate and its corresponding decay, allows a golf ball to travel further distances. In order to achieve a greater moment of inertia, the weight of the ball is shifted from the center of the ball 3 to the thread winding layer 1 . This is done by (and not necessarily in this order): (1) reducing the amount of weight enhancing materials in the compound forming the center, which lowers the center's 3 specific gravity; and (2) by incorporating a filler material having a high specific gravity (SG) in the approximate range of 5.6 or higher and a preferred SG of 19.3 (fine tungsten powder) into the thread and/or by substituting conventional thread materials with materials having a specific gravity value greater than 0.94, more particularly 0.96 and greater, even more particularly 1.00 and greater, and still even more particularly 1.2 and greater.
[0017] Filler materials having a high specific gravity are used in the thread or any material because they occupy the least volume in any compound for a given weight and therefore, do not influence or reduce other desirable properties inherent in the wound golf ball such as resilience, controllability and feel. A listing of such inorganic elements or possible filler materials is provided in Table-1 below.
[0018] In one embodiment of the invention, threads incorporating such high specific gravity filler materials are prepared by incorporating said filler materials at the thread compound mixing or formulating stages. This is then calendered or finished to the required dimensions. The weight percentage of tungsten in the thread compound ranges from 0.1% to 30%, while in one embodiment, a weight percentage of 9.9% is noted. The volume percentage of tungsten in the thread compound ranges from 0.1% to 10.0%, while in one embodiment, a volume percentage of 0.5% is noted. Hence, in the embodiment noted above, a compound formula of 11 lbs of tungsten powder per 100 lbs of rubber is utilized. Once the compound is produced, it is then cured and slit, as is normally done in the conventional thread manufacturing process. Other suitable thread manufacturing processes and/or materials may also be employed to increase the specific gravity of the thread to a value greater than 0.94, more particularly 0.96 and greater, even more particularly 1.00 and greater, and still even more particularly 1.2 and greater. This may be achieved by employing highly resilient polyurethane, TPEs or any other known materials having a specific gravity of 0.94, more particularly 0.96 and greater, even more particularly 1.00 and greater, and still even more particularly 1.2 and greater (either with or without the addition of high SG fillers), which would provide the functional properties necessary in its use and also the increased specific gravity that would lead to an increased moment of inertia in the ball.
[0019] The dimension of the thread ranges from 0.008-0.028×0.015-0.125 inch, while in one embodiment, the dimension of the thread is approximately 0.017″×5/64 inch and has a specific gravity of about 0.95 to 1.25, most particularly 1.04. This specific gravity can be higher or lower depending on the amount of tungsten filler added to the thread compound and/or the non-filler thread material used. The specific gravity of the thread without the addition of weight enhancing materials is about 0.94.
[0020] By adding high specific gravity fillers to the thread winding layer 1 and/or by using materials with inherently higher (greater than 0.94, more particularly 0.96 and greater, even more particularly 1.00 and greater, and still even more particularly 1.2 and greater) SG values, the resulting golf balls produced can achieve an increased moment of inertia, which translates into increased ball performance, particularly in the areas of Driver Carry Distance and Driver Carry plus Roll Distance. Table-2 below provides calculated data for four conventional golf ball constructions, and compares them to Ball #3, which represents a typical embodiment of the present invention whereby tungsten powder is incorporated in the thread compound of the thread winding layer 1 . The values given in Table-2 represent one embodiment of the invention (Ball #3); however, there are many conceivable variations (of Ball #3) as will be discussed below.
[0021] The center size of Ball #3 can range from 1.00-1.48 inches; the center weight of Ball #3 can range from 15-35 grams; the core size of Ball #3 can range from 1.48-1.68 inches; the core weight of Ball #3 can range from 30-40 grams; the diameter of Ball #3 can range from 1.58-1.78 inches; the weight of Ball #3 can range from 40-50 grams; the calculated Moment of Inertia of Ball #3 can range from 12.4-13.4 (g-in 2 ); the Specific Gravity (SG) of the Center of Ball #3 can range from 1.2-1.3; the SG of the threads layer of Ball #3 can range from 0.7-1.25; the SG of the core of Ball #3 can range from 1.0-1.2; the thread layer weight of Ball #3 can range from 2.5-25.0 grams; and the thread layer thickness of Ball #3 can range from 0.05-0.35 inches. With these parameters, a Driver Carry Distance of at least 258.16 yards and a Driver roll & Carry Distance of at least 277.68 yards is achieved.
[0022] It is to be understood that the present invention is by no means limited to the particular constructions herein disclosed and/or shown in the drawing, but also comprises any modifications or equivalents within the spirit and scope of the claims.
TABLE-1 Inorganic Element Specific Gravity Tungsten 19.3 Bismuth 9.8 Copper 8.9 Bismuth oxide 8.9 Nickel 8.9 Cobalt 8.9 Iron/Steel 7.7 Tin 7.3 Chromium 7.2 Zinc 7.1 Bismuth subcarbonate 6.9 Cupric oxide 6.4 Barium tungstate 6.4 Cuprous oxide 6.0 Ferrous oxide 5.7 Zirconium dioxide 5.5
[0023] [0023] TABLE-2 Ball Data: Ball #1 Ball #2 Ball #3 Ball #4 Ball #5 Type 3-piece 3-piece 3-piece 2-piece 2-piece Center Size 1.125 1.35 1.35 n/a n/a ( in inches) Center Weight (g) 17.0 26.65 26.0 n/a n/a Core Size 1.575 1.575 1.575 1.509 1.539 ( in inches) Core Weight (g) 35.65 35.65 35.65 34.60 36.5 Ball Size 1.68 1.68 1.68 1.68 1.68 ( in inches) Ball Weight (g) 45.5 45.5 45.5 45.5 45.5 Calculated Moment 12.43 12.45 12.57 12.52 12.54 of Inertia (g-in 2 ) Specific Gravity (SG) — 1.262 1.232 — — Of Center SG of Thread Layer — 0.725 0.777 — — SG of Core — 1.063 1.063 — — Thread Layer — 9.00 9.65 — — Weight (g) Thread Layer — 0.1125 0.1125 — — Size ( in inches) Flight Data: Driver Carry Distance — 254.64 258.16 — — (yards) Driver Carry & — 272.63 277.68 — — Roll Distance | A thread wound golf ball having improved characteristics of moment of inertia, spin, and total flight distance, comprising a center, a thread winding layer disposed over the center forming a core, and a cover disposed over the core. The improved characteristics are achieved by shifting the weight of the golf ball from the center towards the periphery by use of heavy thread. This could be achieved by adding a high specific gravity filler material, such as tungsten, to the conventional thread compound and/or using polymer materials in the thread that are inherently heavier. By using a high specific gravity filler material, other desirable characteristics inherent in a wound ball such as resilience, controllability and feel, are not affected. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to devices, including cardiac pacemakers, tachycardia reversion devices, and defibrillators, for measuring the response of the heart to an electrical stimulation very soon after the generation of a stimulus, even when the same electrode is used for stimulating and sensing. More specifically, this invention relates to such devices which are optimized to function properly in noise environments and with suboptimal leads. Furthermore, this invention relates to such devices capable of performing self-diagnoses for determining when accurate sensing is not possible.
It is desirable to accurately measure the response of the heart to an electrical stimulation pulse for a number of purposes. The initial objective for performing such measurements was the development of threshold tracking systems requiring the simple detection and distinction of a systolic event from a subthreshold non-event. More recently, stimulated response analysis has been used to control pacing rate, to detect physiological effects of drugs, and to diagnose abnormal conditions of the heart.
Stimulus polarization artifacts can interfere with the recording and analysis of the stimulated response. Consequently, there arose a need for accurate methods for eliminating the stimulation artifact and identifying the true nature of the stimulated response. The ability to automatically reduce stimulus polarization artifacts is necessary in a system which analyzes the depolarization waveform stimulated by a pulse because, in addition to generating a cardiac response, an electrical stimulus gives rise to a form of noise called the stimulus artifact. When a device generates an electrical stimulus within the heart, it creates electrical charges which are stored in the body tissues. The stimulus polarization artifact is the signal arising from the dissipation of these stored charges. The amplitude of the stimulus polarization artifact is normally so much greater than that of signals arising from a natural heartbeat or the stimulated response that it is usually futile to sense these diagnostic signals until the stimulus polarization artifact charges dissipate. This is especially true when, as in the case of the preferred embodiment of the present invention, the device uses the same electrode for stimulating and sensing.
To rapidly dissipate these charges and minimize the stimulus polarization artifact at the pacing electrode, the device generates stimulating pulses using a technique known as charge balancing. The procedure and circuit for performing charge balancing is disclosed in U.S. Pat. No. 4,821,724, entitled "Pacing Pulse Compensation", which issued on Apr. 18, 1989, and refers to the method as active recharge. This patent is assigned to the assignee of the present application and its disclosure is incorporated herein by reference. In this procedure, the device generates a triphasic stimulus, with the first and third phases being of one polarity and the second being of the opposite polarity. The amplitudes of the first and second phases are substantially proportional to each other. The third phase drives a current through the stimulating electrode until the voltage equals the starting quiescent voltage.
The charge balancing technique, as performed by the preferred embodiment of the present invention, requires circuitry for sensing cardiac electrical activity including natural polarizations, stimulated potentials and artifacts. This sensing circuitry is disclosed in U.S. Pat. No. 4,692,719, entitled "Combined Pacemaker Delta Modulator and Bandpass Filter", which issued on Sep. 8, 1987. This patent is also assigned to the assignee of the present application and its disclosure is incorporated herein by reference.
Stimulating the heart using the triphasic stimulus waveform allows the device to effectively reduce the polarization artifact, but the best balance of the three phases of the stimulation waveform is not predictable. The apparatus and method of the present invention provides a mechanism for automatically adjusting or balancing the triphasic stimulus waveform in vivo.
SUMMARY OF THE INVENTION
Briefly stated and in accordance with one aspect of the present invention, there is provided an apparatus for generating a triphasic stimulus for exciting the heart. The triphasic stimulus waveform consists of timed segments called the precharge, stimulus, and postcharge segments. The device automatically varies the duration of the precharge segment until the amplitude of the stimulation artifact is small compared to the cardiac response evoked by a stimulation pulse. To effectively separate the stimulus polarization artifact from the polarization of the heart while beating, either naturally or in response to a stimulation pulse, the apparatus introduces a stimulus and measures the subsequent segment of the intracardiac electrogram during the refractory period of the heart. This technique of stimulating and measuring the polarization during the refractory period is called refractory pulsing. The apparatus measures the intracardiac electrogram and adjusts the precharge to minimize the polarization artifact shortly after the refractory pulse.
Physiological variations in cardiac polarization during the refractory period may occur during the refractory sampling, causing the device to incorrectly set the precharge duration. The device measures the refractory samples of the intracardiac electrogram in the absence of a refractory pulse to create a template signal which compensates for such physiological variations. While adjusting the precharge duration, the device compares the refractory samples with the template to determine whether to increase or decrease the precharge duration.
In some circumstances, the device will not be capable of minimizing the stimulus artifact to a degree which will provide for safe operation of the diagnostic and control function of the device. For example, leads may become displaced or otherwise become incapable of performing properly. The apparatus performs self-diagnosis to determine when further performance of the diagnostic or control function becomes unsafe and automatically terminates that function under such conditions.
Considering the natural variability and unpredictability of biological signals, one objective of this invention is to maximize the reliability of the decision-making process of the diagnostic or control function. Consequently, the device generates the stimulus and senses the signal in a manner which optimizes the diagnostic features of the stimulated polarization waveform. The device automatically adjusts sensing sensitivity to provide the largest signal without saturation. In addition, the system adjusts the stimulation amplitude to the smallest level which will generally successfully stimulate the heart and monitors the heart response to guarantee that the heart is successfully stimulated before performing the diagnostic measurement. The automatic stimulation amplitude function insures that the device compares similar signals over time. The device also improves diagnostic reliability by performing automatic artifact reduction to minimize the size of the stimulus polarization artifact. The stimulated cardiac depolarization potential analysis methods of the present invention fit efficiently into the framework of a stimulated signal sensing and analysis system.
The above objects and advantages, in addition to others that will appear in the detailed description of the invention, will be more clearly understood by reference to the accompanying drawings, the following description, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an illustrative embodiment of the invention in the form of a threshold tracking stimulation apparatus;
FIG. 2 depicts the form of the triphasic stimulation pulse generated by an output generator block of FIG. 1;
FIG. 3 is a flow chart illustrating the operational steps of stimulus artifact reduction, automatic sensitivity control, and automatic stimulus output determination performed by the illustrative embodiment of the invention;
FIG. 4 is a flow chart illustrating the operational steps of the stimulus artifact reduction function performed by the illustrative embodiment of the invention;
FIG. 5 is a sample illustration of a stimulated intracardiac electrogram QRST-complex waveform as sampled and measured by the apparatus during the template acquisition sub-procedure; and
FIG. 6 is a sample illustration of a stimulated intracardiac electrogram QRST-complex waveform as sampled and measured by the apparatus during a stepwise artifact reduction sub-procedure.
DETAILED DESCRIPTION
FIG. 1 depicts, in highly symbolic block-diagram form, an apparatus, shown generally at 1, for performing automatic reduction of the stimulus polarization artifact, enabling the accurate evaluation of the electrical response of the heart. The fundamental requirements for such a device include the ability to generate and deliver, at selected intervals, electrical stimulation pulses of varying amplitudes and forms. The device must then sense the intracardiac electrogram waveform shortly after delivering a stimulus pulse and convert the waveform into a proper form for analysis. The device then analyzes the signal and from this analysis controls the amplitude and form of subsequent stimulation pulses in a manner which minimizes the stimulus polarization artifact. The device may then further analyze the electrical response of the heart, using a similar stimulation and sampling procedure, to perform such functions as automatic stimulation threshold tracking, stimulation rate control, and various procedures to diagnose malfunctions of the heart.
A controller 11 controls all of the other blocks of FIG. 1. In particular, the controller determines the amplitude and morphology of the stimulating pulse and also sets the timing of pulse delivery. The controller sets the pulse delivery parameters for the purpose of charge balancing the stimulus output. The controller also governs the timing and number of intracardiac electrogram samples in addition to determining and executing any signal filtering required for signal analysis. As the controller performs signal sampling, it carries out the analysis necessary for the diagnostic purposes of the device, as described below.
A telemetry block 14 is conventional in modern implanted cardiac pacemakers and defibrillators. It allows both adjustment of the data acquisition parameters from an external programmer and the transmission of information from the implanted apparatus to the external device. This information includes accumulated data and a signal representative of the instantaneous sensed intracardiac electrogram. Present-day sophisticated telemetry circuits allow for the interrogation of stored diagnostic data and the derivation of real-time operational data.
The apparatus uses a form of delta modulation to produce a digital signal for analysis by controller 11. An analog-to-digital block 12 is provided with a signal called ANGL -- CMP from a sensing and polarization controller 15. The ANGL -- CMP signal is a two level waveform representing the sensed signal as a sequence of bits indicating the time history of increases and decreases in the signal amplitude. The analog-to-digital block 12 converts the bit sequence into a form which the controller can read to perform the functions of sensing and intracardiac electrogram acquisition. The output signal of the analog-to-digital block 12 tracks the input signal in the sense that the output represents a 1 value when the input is increasing and a 0 value when the input is decreasing.
The controller 11 has a direct connection for controlling the sensing and polarization controller 15. The sensing and polarization controller has control circuits for performing data acquisition and pulse generation. To control sensing sensitivity, the controller 11 writes commands into the sensing and polarization controller 15 to adjust an 8-bit register which, in turn, sets each of eight switches within a resistor network circuit to an open or closed condition.
Control words written from the controller 11 to the sensing and polarization controller 15 determine the configuration of its sensing and stimulation circuits. The device delivers a negative polarity stimulus through that conductor of a lead 16 which has an electrical connection to the tip electrode of the lead. Other electrode connections of apparatus 1 are its case (the electrical connection is with the physical case of the device) and the ring electrode of lead 16. The device may connect in either a unipolar or bipolar fashion to lead 16. When connected in a unipolar mode, the active electrode is at the lead tip, which is in contact with the cardiac tissue to be stimulated, and the indifferent electrode is the case of the implanted device. When connected in a bipolar mode, the indifferent electrode can be either the case or the ring electrode, which is an annular electrode on the lead a short distance from the tip electrode. A command code written by the controller 11 determines the settings of switches to determine which electrode is active and which is indifferent during stimulation as well as sensing. The code may specify a different switch setting during stimulation as compared to sensing. Switch settings determine the operative configuration of the device: bipolar, unipolar tip-case or unipolar ring-case. Unipolar signals, arising from cardiac potentials accumulated over a larger surface of the ventricle, generally contain more information than bipolar signals, providing a more reliable diagnostic result. On the other hand, bipolar signals offer better rejection of noise, including muscle and motion artifacts, and provide the most detailed signal description of the electrophysiological state from a localized region of the ventricle. Control bytes written by the controller 11 to the sensing and polarization controller 15 determine the setting of other switches to accomplish the tasks of various modes of stimulation and sensor measurement acquisition. These switch settings are described in detail in the aforesaid U.S. Pat. No. 4,821,724.
An output generator 13, in response to control bytes written by the controller 11, prepares for stimulation by storing electrical charge on capacitors and delivers the stimulating pulses, as described in said U.S. Pat. No. 4,821,724. Control bytes written to the output generator by the controller 11 determine the amplitudes, polarities and durations of the phases of the pacing stimulus pulses. Referring to FIG. 2, wherein a pacing stimulus pulse is illustrated, the pacing stimulus pulse includes four periods or zones, called precharge, stimulus, postcharge, and blanking. It is to be understood that the waveform of FIG. 2 is not drawn to scale. The controller 11 determines the duration of the precharge period, the postcharge interval duration (typically about 8 milliseconds), and the width of the negative portion of the stimulus pulse (usually in the range of 0.1 to 1.0 and commonly 0.5 milliseconds). After the stimulus pulse, the output generator times a blanking interval of about 300 microseconds to allow the circuit to settle after stimulation. The waveform of FIG. 2 represents the potential between the conductors of the lead 16 of FIG. 1. One objective of the invention is for the controller to set the amplitudes and durations for these four periods in a manner to minimize the stimulation polarization artifact at the tip or pacing electrode, providing reliable sensing of the heart's stimulated potential resulting from a generated pulse.
For a particular implanted lead, the controller 11 can adjust the precharge period to minimize the after-potential at the pacing electrode following the 8 millisecond postcharge duration. The precharge duration ranges from 0 to about 4 milliseconds. A typical precharge period is about 3 milliseconds when using an 8 millisecond postcharge interval. The device uses an arbitrarily selected postcharge duration of 8 milliseconds, since this is sufficiently short to permit sensing of the stimulated potential.
The controller 11 writes set-up and duration information to a timer 17. The timer 17 responds to this information by generating wake-up signals to the controller after the designated time expires. The controller uses timer wake-ups to govern the timing of cardiac cycles as well as to time short-term intervals for miscellaneous operations including the setting of timing for intracardiac electrogram sampling. In addition, the controller uses timer wake-up signals to control a real-time clock function for determining the length of time since manufacture of the device and for initiating long-term housekeeping functions. When the controller, in conjunction with the real-time clock signal, determines that a measurement and analysis session is due, it begins a measurement procedure illustrated in FIG. 3.
FIG. 3 is a flow chart illustrating a procedure for measuring the stimulated potential, reducing the polarization artifact, setting sensing sensitivity (gain), and determining the minimum stimulation amplitude for safely activating the heart in the illustrative embodiment of the invention. Although the stimulus duration remains constant throughout the procedure in this embodiment of the device, it is to be understood that varying either or both the stimulus duration and amplitude to adequately stimulate the heart is considered to be within the scope of this invention. Although the external programmer may set the configuration of the device to stimulate and sense signals on the lead 16 in either the unipolar or bipolar modes, the selected mode should remain constant throughout the procedure of FIG. 3.
When a device is performing cardiovascular monitoring or control operations, the best results are accomplished when the polarization artifact is optimally reduced to a level that is small in comparison to sensed stimulated potentials and intrinsic cardiac events. Using some leads, a directly recorded tip intracardiac electrogram does not produce suitable signals for analysis no matter how the stimulation parameter settings are programmed, unless the device minimizes the polarization artifact. This procedure may be called charge balancing because its goal is to determine a combination of charges delivered in the two positive phases and the single negative phase of the stimulus waveform which results in an acceptably small polarization artifact.
The polarization artifact reduction procedure of FIG. 3 includes nine sub-procedures: start signature 50, initial artifact reduction 51, automatic gain 52, initial stimulated activity threshold 53, vario 54, final artifact reduction 55, final stimulated activity threshold 56, end signature 57, and stimulated potential sampling 58. In the eight sub-procedures (50 to 57), the device performs polarization artifact reduction and automatically adjusts the sensing amplifier gain and the stimulus pulse amplitude. We refer to these first seven sub-procedures as the polarization artifact reduction procedure. In the stimulated potential sampling 58 sub-procedure, the device performs a stimulated response analysis procedure for stimulation threshold tracking, automatic rate responsiveness, or various methods for diagnosing abnormal heart activity.
The controller 11 performs the polarization artifact reduction procedure, beginning with the start signature 50 sub-procedure, when any of the following events occur: a system hardware or software reset, an authorized external device sends a "start procedure" command using telemetric communication, an internal timer set to periodically restart the procedure times out, or the delivered stimulus fails to stimulate a response by the heart in three consecutive stimulus cycles.
In addition to reducing the polarization artifact, the procedure of FIG. 3 addresses fusion events, another problem creating difficulties when attempting to accurately measure stimulated cardiac signals. Fusion events are natural cardiac depolarizations occurring simultaneously with at least some portion of the stimulated potential polarization which changes the morphology of the sensed intracardiac electrogram signal. The preferred embodiment of the invention addresses fusion problems by elevating the cardiac stimulation rate to a level higher than the natural rate. When the event initiating the polarization artifact reduction procedure occurs, the controller performs initialization operations. In the usual operation of the cardiac stimulation device, when the device is not performing the polarization artifact procedure, software continuously updates an average of cardiac cycle interval lengths (stimulated or sensed). The preferred embodiment of the invention determines a weighted running average of interval lengths by adding the current interval to three times the running average and dividing this result by four. Determining the average in this manner is economical in terms of memory and current usage. Upon the event initiating the procedure, software converts the aforesaid running average interval into a rate and begins overdriving the average rate by a predetermined overdrive increment (for example, 25 bpm), but limiting the rate to a programmed maximum. The device continues to pace at this overdrive rate for the entire polarization artifact reduction procedure which endures, for example, for two to three minutes. To prevent the device from constantly boosting the rate in a positive feedback loop, it discontinues the updating of the running average of cardiac interval durations whenever it is overdriving the natural rate.
The purpose of the start signature 50 sub-procedure is to provide notification to anyone monitoring the cardiac signal that the device is beginning an operation which will automatically alter important stimulus parameters. Normally, a cardiac stimulation device generates a stimulus once each cardiac cycle (unless the heart beats naturally in a timely manner) upon the time-out of an internal timer. In the start signature 50 sub-procedure, the device provides the notification operation by generating a second pulse shortly after the stimulus. The time interval between pulses (for example, 75 msec) is sufficiently short so that the second pulse is within the refractory period, when it cannot stimulate the heart muscle. The paired pulses are called signature pulses. If the event initiating the polarization artifact reduction procedure is the periodic time-out of the internal timer, then the amplitude of the signature pulses is the value determined in the last threshold search operation, the stimulation threshold plus a safety margin predetermined to insure that the stimulus will normally generate a response. If any other event starts the procedure, the signature pulse amplitude is 7.5 V.
In the preferred embodiment of the invention, if the amplitude of the signature pulse delivered in block 50 of FIG. 3 is 7.5 V, then the controller 11 sets the stimulus pulse amplitude to 3.75 V for the initial artifact reduction 51 sub-procedure to be described. This reduction in amplitude is necessary due to the difficulty in reducing the stimulation polarization artifact at high pulse amplitudes. If the signature pulse amplitude is the stimulation threshold plus a safety margin, the controller continues to generate this amplitude for subsequent pulses.
After delivering the signature pulses, the controller performs the initial artifact reduction 51 sub-procedure. The procedure also enters initial artifact reduction 51 if the stimulation amplitude is determined by the vario 54 operation, hereinafter described, and this stimulation fails to evoke a cardiac response for three consecutive stimulation cycles while the device is operating in one of the sub-procedures following initial artifact reduction but prior to end signature 57. The procedure also recycles to the beginning of the initial artifact reduction 51 sub-procedure upon a single non-consecutive residual artifact test failure (this test is discussed below) during either artifact reduction sub-procedure (51 or 55).
The purpose of residual artifact reduction is to distinguish polarization artifact from stimulated cardiac depolarizations and to eliminate or reduce the amplitude of the artifact. The device does this by generating a stimulating pulse during the absolute refractory period of the heart.
When the cardiac cycle timer expires, the device delivers a stimulus to cause a heart beat then samples the intracardiac electrogram of the stimulated response and calculates activity to determine whether the stimulus successfully stimulated the heart. "Activity" is the measurement of the heart response. In the preferred embodiment of the invention, software determines activity by sampling the output signal of the analog-to-digital block 12 (of FIG. 1) every four milliseconds following the blanking period after the stimulus generation, and continues to sample for a sufficient period of time for the heart's response to be detected. The controller 11 synchronizes the timing of the samples to the trailing edge of the negative phase of the stimulation pulse, with the first sample taken at the first multiple of four milliseconds which occurs after the blanking period. To determine activity, software acquires and digitally double integrates six samples. In the preferred embodiment of the invention, the samples are in the form of delta modulator values or readings, in accordance with U.S. Pat. No. 4,692,719, mentioned earlier herein. These delta modulator values are measurements of the sensed signal amplitude difference between a current sample and a previous sample. The double integration procedure requires the accumulation of two sums, the first integral sum and the second integral sum which software initializes to zero before the first sample following the stimulus pulse. Software produces the first integral sum by adding the value of the current sample to the sum of the previous samples. Software derives the second integral sum by adding the value of the current first integral sum to the sum of the previous first integral values. The final double integral summation value represents the activity of the heart's response to the stimulation pulse. When the activity value exceeds a predetermined value, it indicates the occurrence of a responsive heartbeat. The result of the first integration reconstructs the time waveform of the intracardiac signals and the result of the second integration expresses the area under the waveform curve.
Signals sampled using bipolar sensing may display a biphasic morphology within the six samples. Unipolar signals are typically monophasic and negative. The Q-S width portion of FIG. 5 and FIG. 6 illustrate this difference. Double integration samples acquired when the sensing circuits are configured in the bipolar mode would be too inaccurate for clinical usage. Accordingly software accumulates the absolute value of the intermediate sum into the final sum while performing in the bipolar sensing mode. Since signals measured when circuits are configured in the unipolar configuration nearly always have a negative polarity, software reverses the sign of the intermediate integral sums before accumulating the second integral sum. If such a result is negative in sign, software sets it to zero.
Software compares the activity to a stimulated activity threshold value derived in the most recent stimulated activity threshold operation (53 or 56 of FIG. 3). (If no stimulated activity threshold operation has taken place under the current stimulation conditions, the controller may initialize the stimulated activity threshold value to a low magnitude, even zero, to guarantee that the procedure will not fail unnecessarily when the value is not known.) If activity is greater than the stimulated activity threshold value, software determines that the pulse successfully stimulated the heart. If the pulse does not stimulate the heart, any further data analysis for the current cardiac cycle ends. It is possible that the low activity value may actually indicate a fusion event rather than a failure to stimulate the heart. Since the device can avoid the problems arising from fusion events by further overdriving the pacing rate, it responds to the detected failure to stimulate the heart by increasing the pacing rate by 15 bpm for a single failure and by 10 bpm more to a total of 25 bpm for the second of two consecutive failures. Software limits the overdrive rates to the programmed maximum. To prevent the device from failing to sense a subsequent natural heartbeat after a single failure, the device begins sensing after a short delay following the determination that the heart did not respond to the stimulus. In the case of either two or three consecutive failures, the device issues a backup stimulation pulse soon after the last of such inadequate stimulus pulses (about 125 msec). The backup stimulus has twice the pulse duration of the original stimulus to sustain the patient in case the patient's health is dependent on such stimulation. If the stimulus fails to activate the heart on three consecutive cycles, the operation of the procedure either restarts the initial artifact reduction 51 sub-procedure if this is the first failure within an artifact reduction procedure, or terminates the procedure by delivering the end signature pulses in block 57 if this is the second such failure. The device responds to the failure to stimulate the heart in this manner for all sub-procedures of the artifact reduction procedure, except that the method for the vario 54 sub-procedure differs slightly, as will be described below.
Upon successful stimulation of the heart, the device delivers an additional pulse, called a refractory pulse, during the heart's refractory period (for example, about 125 ms after the stimulus pulse). By generating this pulse during the absolute refractory period, after which any signal sensed is due primarily to polarization artifact, the device distinguishes the polarization artifact from either stimulated or natural cardiac depolarizations. Following the refractory pulse, the device performs two sampling operations of the polarization artifact signal. In the first sampling operation, software performs residual artifact sampling after the trailing edge of the refractory pulse using the same sampling procedure (six samples acquired at four millisecond intervals) as was performed while determining the activity following the stimulus pulse. In the second sampling operation, the device measures the polarization artifact to derive an artifact reduction parameter. Software performs an artifact reduction parameter accumulation on the first two or three samples acquired during the first sampling operation, in a manner similar to that done in connection with the double integration to derive the activity, except that the artifact reduction parameter accumulation persists for two or three samples rather than six and the second summation accumulates the intermediate sum without changing the sign of the first integral of the signal. Experimentally, these two or three samples were shown to characterize the peak amplitude of the first phase of a typically biphasic polarization artifact for the purpose of performing adjustments to reduce this artifact as will appear in greater detail below.
In both artifact reduction sub-procedures (51 and 55), the controller 11 performs the operations, shown in FIG. 4, of template acquisition 61, stepwise artifact reduction 62, and residual artifact determination 63. During template acquisition 61, the controller measures the underlying intracardiac electrogram signal detected during refractory sampling in the absence of a refractory pulse. The purpose of stepwise artifact reduction 62 is to automatically adjust the precharge duration of the triphasic stimulus waveform in vivo, in a small step within each cardiac cycle, to eliminate or reduce the polarization artifact. The device varies the precharge duration until the polarization artifact is small in comparison to the ventricular stimulated response. In the residual artifact determination 63, software corrects the intracardiac electrogram signals measured following a refractory pulse to remove therefrom the underlying intracardiac electrogram signals which were sampled during template acquisition 61. Software then uses the resulting residual artifact parameter for device self-diagnosis and control as will appear in greater detail below.
In the first task of the template acquisition 61 operation, the controller initializes the precharge duration to the value determined in the most recent successful initial or final artifact reduction sub-procedure. Software run by the controller performs this task only if the stimulus pulse amplitude is 3.75 V. If the stimulus pulse amplitude is the previously determined stimulation threshold plus margin value, the device is performing the polarization artifact reduction procedure for the purpose of maintenance rather than because of a form of system failure and there is no reason to change the precharge duration in a properly functioning system. Following this initialization task, the stimulus pulse amplitude and precharge duration remain unchanged throughout the template acquisition 61 and the stepwise artifact reduction 62 operations. To allow the controller to measure the underlying electrogram signal occurring during the sampled portion of the heart's refractory period, it sets the refractory pulse amplitude to zero volts for template acquisition 61. The precharge duration for the refractory pulse is the same as that for the stimulus pulse. Template acquisition 61 lasts for eight cardiac cycles, during which software measures and accumulates samples of the underlying intracardiac electrogram signal during both the aforesaid six sample sampling operation to create a residual artifact template for correcting the residual artifact signal, and during the two or three sample sampling operation to create an artifact reduction template which is necessary for performing stepwise artifact reduction. The templates are created by summing and averaging the double integral values obtained during the eight cardiac cycles.
FIG. 5 illustrates a typical stimulated intracardiac electrogram waveform as detected by the device sensing in the unipolar mode during the template acquisition operation. (During template acquisition, the refractory pulse amplitude is zero volts). Vertical lines on the waveform indicate times at which the apparatus performs sampling operations. During the first group of six samples, the device ascertains whether the stimulation pulse successfully evoked a response from the heart. During the second group of six samples, the device averages (for eight cardiac cycles) the integral of the first three samples to determine the artifact reduction parameter template and averages the integral of all six samples to determine the residual artifact template.
During stepwise artifact reduction 62, while generating both the stimulus and the refractory pulses using the triphasic waveform of FIG. 2 (precharge, stimulus, and postcharge), the device 1 varies the precharge duration until the refractory polarization artifact is small in comparison to the ventricular stimulated response. The controller sets the pulse amplitude for the refractory pulse to 2.5 V if the stimulus pulse amplitude is 3.75 V, otherwise the device maintains a refractory pulse amplitude of stimulus threshold plus margin (the same amplitude as for the stimulus pulse). A stimulus pulse amplitude of 3.75 V implies that the threshold stimulus pulse amplitude is not known. Since the threshold stimulus pulse amplitude may range from 3.75 V down to 0.5 V or lower and the precharge duration which minimizes the polarization artifact varies nearly proportionally to the stimulus pulse amplitude, minimizing the polarization artifact starting from a refractory pulse amplitude of 2.5 V will provide a mid-range precharge duration to best reduce the artifact throughout the range of amplitudes which will be spanned in the subsequent vario 54 operation.
The device 1 samples and accumulates the artifact reduction parameter for each cardiac cycle and subtracts the artifact reduction template from the artifact reduction parameter, then adjusts the precharge duration by about 30 usec in the direction of the sign of the subtraction result. Because the polarization artifact represents a sensing amplifier's (not shown) response to an offset voltage (polarization) on the lead electrodes, the controller 11 uses the polarity of the first phase of the artifact to determine which direction to change the precharge duration for the refractory pulse to further reduce the artifact amplitude. The precharge duration of the stimulus pulse remains unchanged at this time. The controller increases the precharge duration if the first phase of the polarization artifact is positive, otherwise it decreases the duration. The output generator 13 and the sensing and polarization controller 15 are designed to function properly in combination with a wide variety of leads 16. Leads are constructed from many types of materials and have very different electrical characteristics (for example, impedances). An excessively large or small precharge duration value may create a large artifact which the artifact reduction operation 62 of FIG. 3 cannot reduce. For this reason, software imposes predetermined upper and lower limits on precharge duration. The value of these limits is based on electrical characteristics of the circuits and leads. If the controller attempts to increase the precharge duration above the upper limit or decrease the precharge duration below a lower limit (this is usually zero usec), then the stepwise artifact reduction operation 62 finishes. While the device is performing the stepwise artifact reduction step within the prescribed limits, at some point further changes in precharge duration will either completely eliminate the polarization artifact or cause it to reverse polarity, depending on the sensing amplifier gain, stimulus energy, and characteristics of the electrode system. A polarization reversal occurs when the change in precharge duration causes the result of the subtraction to change in sign as compared to the result of the previous cycle. After a predetermined number of polarization reversals (for example, four), the controller determines that the polarization artifact is sufficiently reduced and the sub-procedure sequences to the residual artifact determination 63. The device requires a number of polarization reversals to provide protection against incorrectly determining the proper precharge duration in the presence of fusion events. Because some leads produce only a very minor polarization artifact for the procedure to eliminate, the controller also terminates the stepwise artifact reduction operation 62 if the sub-procedure endures longer than a predetermined number of steps (for example, 128). The precharge duration resulting from the residual artifact determination operation is the optimum precharge duration.
FIG. 6 illustrates a stimulated intracardiac electrogram waveform, similar to that of FIG. 5, after the device has increased the refractory pulse amplitude for the stepwise artifact reduction operation from the zero voltage of FIG. 5 to the refractory pulse amplitude for stimulus polarization artifact reduction discussed two paragraphs earlier herein. The refractory pulse occurs at point RP in FIG. 6 and this results in the perturbation of the waveform following the refractory pulse. This perturbation is an example of the stimulus polarization artifact. Its amplitude and duration depend on the precharge duration, among other factors as discussed earlier. As shown, the three artifact reduction parameter samples are taken during the early part of this stimulus polarization artifact. After acquiring the three samples, the device 1 performs stepwise artifact reduction by adjusting the precharge duration value, in the manner described in the preceding paragraph.
In the residual artifact determination 63 operation which occurs for eight cardiac cycles following the stepwise artifact reduction 62 operation, the controller 11 first sets the precharge duration of both the stimulus and the refractory pulses to the newly determined optimum precharge duration. The controller maintains the same stimulus and refractory pulse amplitudes in the transition from the stepwise artifact reduction to residual artifact determination. For the eight cardiac cycles of the residual artifact determination 63, software measures and accumulates only the residual artifact value (not the artifact reduction parameter). On the eighth cardiac cycle, the controller divides the accumulated residual artifact by eight and subtracts from it the residual artifact template determined by the previous template acquisition operation 61. This result is the template-corrected residual artifact. In the final operation of the residual artifact 63 operation, the controller saves the optimum precharge duration in memory for usage in future residual artifact reduction operations in case the procedure restarts for a reason other than timed recycling.
Physiological or external noise (for example, 60 cycle noise) is one phenomenon which may influence the operation of the artifact reduction procedure. The device detects such noise by measuring intracardiac electrograms during the heart's relative refractory period. For each sensed signal with an amplitude change greater than a predetermined sensing threshold during the relative refractory period of a cardiac cycle, the controller restarts the refractory period timer and increments the sensing threshold for the remainder of that cardiac cycle. The new sensing threshold endures until a sensed signal greater than such new sensed threshold occurs and restarts the timer and again increments the sensing threshold. After the refractory timer has timed out and prior to the timing out of the cardiac cycle timer, sensed signals inhibit the device from generating stimulus pulses. Once the refractory timer extends beyond the cardiac cycle timer, a sensed signal can no longer inhibit the device from delivering a stimulus pulse. A noise cycle is defined as a cardiac cycle in which the refractory timer extends beyond the cardiac cycle timer due to refractory period recycling. When the device detects a noise cycle, software always suspends the sampling function of the polarization artifact reduction procedure for that cardiac cycle. Because overdriving to elevate the heart rate occurs during this procedure and noise cycle sensing may cause the device to remain in an overdriven state potentially forever, the controller accumulates a noise cycle counter. If noise cycle counter accumulates a count of 256 during a single artifact reduction procedure encompassing blocks 51 and 55 of FIG. 3, the controller jumps to the end signature 57 operation and terminates the procedure, restoring the stimulus pulse amplitude and precharge duration to the results of the most recent successful polarization artifact reduction procedure.
Again referring to FIG. 3, after the successful completion of the initial artifact reduction 51, the controller performs the automatic gain 52 sub-procedure only if an external programmer activates an automatic gain function. When enabled, the automatic gain function procedure sets the gain of the sensing amplifier in the sensing and polarization controller 15 by analyzing samples acquired during the absolute refractory period. The automatic gain 52 sub-procedure sets gain so that sensed signals will have a high amplitude, but not so high as to produce saturated signals. Setting the gain in this manner improves the device's natural heartbeat signal sensing operation as well as its signal analysis capabilities while performing the other sub-procedures of FIG. 3. If the automatic gain function is disabled and an automatic stimulus pulse amplitude function is enabled, control of the procedure proceeds to the initial stimulated activity threshold 53 sub-procedure. When enabled, the automatic stimulus pulse amplitude function allows the device 1 to determine a stimulated activity threshold value which, when sensed and measured, indicates the successful stimulation of the heart and the stimulus threshold pulse margin amplitude value necessary to successfully stimulate the heart, as will be described in detail hereinafter. If neither the automatic gain nor the automatic stimulus pulse amplitude function is enabled, control of the procedure jumps to the end signature 57 sub-procedure.
During automatic gain 52 sub-procedure, the device 1 samples the activity of the intracardiac electrogram and responds to the failure to activate the heart in the manner described previously. If the device successfully activates the heart, it continues to sample the intracardiac electrogram for additional samples. The stimulus pulse amplitude for the automatic gain 52 sub-procedure is the same as the amplitude of the stimulus pulse in the initial artifact reduction 51 operation. The term "stimulated potential signal" is intended to refer to signals generated by the heart during the heart's activation wave in response to a stimulated pulse applied to the heart. It primarily refers to the heart's responsive QRS-complex. The total number of samples is intended to encompass the entire stimulated potential signal, including the QRS-complex. The number of samples taken depends on the bandwidth of the sense amplifier in the sensing and polarization controller (block 15 of FIG. 1). The device 1 measures each of the stimulated potential signal samples to find the largest positive value in four consecutive paced cardiac cycles. On every fourth cardiac cycle, if the largest positive sample is less than or equal to a predetermined automatic gain test level of amplitude, then the device increases the gain setting in the sensing and polarization controller by one count. Otherwise, the controller 11 decreases the gain setting by one count. To prevent a potentially unsafe sensitivity setting, the controller 11 limits the gain setting to predetermined maximum and minimum values. If updating the gain would violate either limit, the gain setting remains the same. In either case, the software tests the current amplitude test result against the amplitude test result from the previous four cycle sample. If the largest positive value from the current sample is greater than the automatic gain test level of amplitude and the largest positive value from the previous sample is not, the condition is an automatic gain amplitude test crossing. Upon the occurrence of a predetermined number of automatic gain amplitude test crossings, the automatic gain 52 sub-procedure finishes and, if the external programmer has activated the automatic stimulus pulse amplitude function, control of the procedure moves to the initial stimulated activity threshold 53 sub-procedure. If the automatic stimulus pulse amplitude function is disabled, control of the procedure jumps to the end signature 57 sub-procedure.
The purpose of the stimulated activity threshold operation is to measure the "stimulated activity threshold value", which is defined as the activity which distinguishes a stimulation pulse amplitude normally capable of generating a response by the heart from the activity of a stimulation pulse amplitude which does not. The stimulus pulse amplitude for the initial stimulated activity threshold 53 sub-procedure is the same as the amplitude of the stimulus pulse in the previous operation (either the initial artifact reduction 51 or automatic gain 52 sub-procedure), except that software limits the amplitude to a value of the maximum allowable stimulus threshold plus the margin (for example, 3.2 V). During the stimulated activity threshold sub-procedure, the controller measures the activity by sampling and double integrating in the manner described previously, then averages the activity for eight successfully sampled cardiac cycles. During a stimulated activity threshold sub-procedure, the device samples the activity of the intracardiac electrogram and responds to the failure to activate the heart in the manner described previously, with one exception. A failure to stimulate the heart in three consecutive cardiac cycles indicates that the stimulus threshold amplitude is greater than the aforesaid maximum allowable stimulus threshold plus margin. If the stimulus pulse amplitude is less than such threshold plus margin, then the controller 11 restarts the procedure by initializing the stimulus pulse amplitude to 3.75 V and looping back to the initial artifact reduction 51 operation. Otherwise, software terminates the procedure by setting the stimulus pulse amplitude to a safe level (for example, 7.5 V) and jumping to the end signature 57 sub-procedure.
After measuring the averaged activity for the eight cycles referred to above, software performs a residual artifact test by comparing the magnitude of the corrected stimulated activity (the averaged activity minus the residual artifact obtained during the artifact reduction sub-procedure 51 or 55) to a preset multiple (for example, eight) of the magnitude of the residual artifact. If the magnitude of the corrected stimulated activity is too small, the system fails the residual artifact test since it is unable to sufficiently reduce the artifact. A residual artifact test failure may indicate a device malfunction or a physiological anomaly such as fusion events. To determine the reason for the test failure, the controller restarts the procedure by initializing the stimulus pulse amplitude to 3.75 V and looping back to the initial artifact reduction 51 operation. If the system fails the residual artifact test for more than a predetermined number of consecutive attempts (for example, two), the controller terminates the procedure by setting the stimulus pulse amplitude to a safe level (for example, 7.5 V) and jumping to the end signature 57 sub-procedure. If the procedure terminates in this manner in a predetermined number (for example, four) of consecutive attempts, the controller 11 prevents further attempts by disabling the procedure. Only intervention by an external programmer over the telemetry link will re-activate the procedure. If the averaged activity signal passes the residual artifact test, software derives the stimulated activity threshold value by subtracting the residual artifact found in the last residual artifact determination operation (block 63 of FIG. 4) from the averaged activity and multiplying the result by a predetermined fractional factor. This factor defines the minimum activity signal that will indicate a successful stimulation of the heart, taking into consideration the average signal level and the detected noise level (the residual artifact), and setting the threshold level between them. In the preferred embodiment of the invention, the value of the factor is either 50 percent or 25 percent, respectively, for signals sensed in the bipolar and unipolar configurations to compensate for the difference in waveforms.
After the successful completion of initial stimulated activity threshold block 53 (FIG. 3), the controller 11 performs the vario 54 sub-procedure to determine the stimulation pulse amplitude normally capable of giving rise to a response by the heart. The beginning stimulus pulse amplitude for the vario operation is the same as the amplitude used when performing the initial stimulated activity threshold 53 sub-procedure. For each vario cardiac cycle, the controller 11 measures the activity as described previously. If the stimulus pulse succeeds in stimulating a cardiac response, the controller decreases the stimulation amplitude by a preset step size (for example, 0.1 V) for the next cardiac cycle. If the stimulus fails to evoke a response, the stimulation amplitude remains the same. After three consecutive failures, the vario operation is complete and the controller increases the stimulation amplitude by a preset voltage margin (0.6 V in the preferred embodiment of the invention) and the device begins performing the final artifact reduction 55 sub-procedure. The vario operation will also terminate without failing to generate a cardiac response if the software decrements the stimulation amplitude below a predetermined minimum stimulation level, such as 0.5 V.
If the device 1 detects a noise cycle during the vario operation, software restarts the stepwise vario function by initializing the stimulus pulse amplitude to the original level for the current sub-procedure. This is done to avoid generating pulses which are inadequate to stimulate the heart during continuing noise cycles. To limit the time a patient is subject to the possibly inadequate stimulus pulse amplitudes tested within the stepwise vario operation, software limits the number of cardiac cycles in which natural activity inhibits pacing or noise occurs during the sub-procedure. If the number of such cardiac cycles surpasses this limit (for example, 32 cycles), the controller 11 terminates the procedure by jumping to the end signature 57 sub-procedure after setting the stimulus pulse amplitude to the value determined in the last vario procedure or, if the device is performing the procedure because of a failure to stimulate the heart, to a safe level (for example, 7.5 V).
After performing the vario 54 operation, software controls the final artifact reduction 55 sub-procedure to minimize the magnitude of the polarization artifact after the pulse amplitude is set to the newly determined stimulation threshold plus margin value. Operations of the final (block 55) and initial (block 51) artifact reduction sub-procedures are identical except for possible differences in the generated stimulation pulse amplitudes.
In the final stimulated activity threshold 56 sub-procedure, the device determines the stimulated activity threshold value for cardiac signals stimulated from pulses having the newly determined stimulation amplitude. Other than possible changes in stimulation pulse amplitude, the final (56) and initial (53) stimulated activity threshold sub-procedures are the same.
End signature 57 sub-procedure provides notification to anyone monitoring the cardiac signal that the FIG. 3 operation is ending. The start (50) and end (57) signature operations are the same except for possible differences in the stimulus amplitude. A successful vario 54 operation will have set the stimulation amplitude to the stimulation threshold plus margin value. A procedure failure such as too large a stimulus threshold value, or failure of the residual artifact test, results in a safe default stimulation amplitude.
The device performs the stimulated potential sampling 58 sub-procedure only if the preceding sub-procedures and tests succeeded. If the automatic stimulus amplitude function is enabled, the stimulation amplitude is the stimulation threshold plus margin value determined in the vario 54 sub-procedure. The stimulated potential sampling sub-procedure 58, interfaces the device 1 to any number of different end uses which require accurate sensing of stimulated potentials (i.e., wherein the stimulated potential artifact has been reduced or eliminated). Examples of such end uses are heart rejection monitors and/or heart rejection drug dosimeters, rate-responsive cardiac pacing wherein the rate-responsive decision parameter is based on characteristics of cardiac depolarization or repolarization, and automatic stimulation threshold tracking wherein stimulus polarization artifact reduction is required to permit accurate evaluation of the stimulated response of the heart.
Considering the device 1 as part of an automatic threshold tracking apparatus, the stimulation potential sampling procedure 58 monitors the activity of the stimulated potential in the manner previously described to determine whether the stimulus amplitude (stimulation threshold plus margin) remains sufficient to activate the heart. While performing automatic threshold tracking, the device 1 reduces the stimulation rate to a non-overdrive rate during the stimulated potential sampling 58 sub-procedure. This operation may occur on every stimulated cardiac cycle or only on selected cycles, as selected by the external programmer. After a single failure to generate a cardiac response, the controller 11 increases the stimulation rate by a predetermined amount (for example, 15 bpm) in case the device incorrectly classifies a fusion event as the failure to stimulate the heart. After two consecutive failures, the controller increases the stimulation rate by a predetermined amount further (for example, to a total increase of 25 bpm) and delivers a backup stimulation pulse in the manner described previously. After three consecutive failures, the controller delivers a backup stimulation pulse, increases the stimulation pulse amplitude to a safe level, and restarts the polarization artifact reduction procedure.
Although the invention is described with reference to particular embodiments, it is to be understood that such embodiments are merely illustrative of the application of the principles of the invention. Numerous modifications may be made therein and other arrangements may be devised without departing from the spirit and scope of the invention. | An apparatus adapted to be implanted in a patient for electrically stimulating the heart and analyzing the heart's stimulated response, and a method of operating the apparatus, are disclosed. The apparatus operates to reduce the stimulation polarization artifact that normally accompanies such stimulation, allowing accurate measurement of stimulated cardiac potentials. The apparatus is useful in such devices as cardiac pacemakers, tachycardia reversion devices, and defibrillators. Optimizing features are provided to allow the apparatus to function properly in noisy environments and with suboptimal leads. In addition, provision is included to make the apparatus capable of performing self-diagnosis for determining when accurate sensing is not possible. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates generally to transmission shift controls and more particularly to a single lever control which operates range shift, two types of speed shift, two types of selected speed lockout, and parking lockup.
In the past, generally two levers were used to control range and speed shifting and, in addition to being difficult to operate, it was possible to shift through incorrect sequences so as to damage the transmission, i.e. shifting ranges without shifting the speed shift to neutral.
SUMMARY OF THE INVENTION
The present invention provides a simple, multi-function, hydromechanical transmission shift control which allows single lever control of the range shift, speed shift, and the high/low speed shift while providing automatic lockout of reverse operation in predetermined ranges, lockout of operation at predetermined speeds, and positive parking lockup.
The above and additional advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded isometric view of the present invention;
FIG. 2 is a top view of an assembly of the present invention with some parts omitted for clarity;
FIG. 3 is an exploded isometric view of a portion of the present invention shown in FIG. 1;
FIG. 4 is a front view of the present invention with some parts omitted for clarity;
FIG. 5 is a side view of the present invention with some parts omitted for clarity;
FIG. 6 is an isometric view of an additional portion of the present invention; and
FIG. 7 is a view taken along line 7--7 of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, therein is shown a tractor transmission shift control 10 for controlling a hydromechanical transmission of the type disclosed in the U.S. Pat. No. 3,774,475 granted to R. R. Meysenburg, the disclosure of which is incorporated herein by reference thereto. Briefly, the Meysenburg transmission utilizes a synchronizer pack speed change mechanism to control the configuration of a first set of gears, a high/low change hydraulic valve to control the configuration of a second set of gears which provide a direct or an underdrive to the transmission, and collar shift range change mechanism to control the configuration of a third set of transmission gears to the final output.
The shift control 10 includes a support member 12 which consists of a pair of longitudinally extending side plates 14 and 16 joined by a cross member 18 and a guide plate 20 which may best be seen by reference to FIG. 2. The guide plate 20 has a shift pattern cutout 22 provided therein which will be described in more detail later.
Returning to FIG. 1, it may be seen that the support member 12 carries a laterally extending primary pivot pin 24 on which a pivoting assembly 26 is mounted. The support member 12 further carries a range shift latch pivot 28 and a high/low pivot 30 on the side plate 14. The side plate 16 carries a speed shift latch pivot 32 and a range stop finger 34. The support member 12 may further be seen to carry a park lockup mechanism 36 which consists of a park arm 38 pivoted on a park pin 40, a rod 42, and a park lockup connection 44 pivoted on a park pivot pin 46. The guide plate 20 carries a reverse lockout mechanism 48, to prevent high reverse speeds, which includes pins 50 and 52 respectively disposed in slots 54 and 56 in the guide plate 20.
Referring now to FIG. 2, therein is shown the guide plate 20 with the shift pattern cutout 22 which includes a neutral cutout 58 and a park cutout 60. The various portions of the shift pattern cutout 22 which define the various range and speed shift positions are designated by the letters "A," "B," "C," and "D" which are the range stops and "1," "2," "3," "4," "1R," and "2R" which are the speed stops for the four forward and two reverse speeds. The letter "P" designates the park stop. Also best seen in FIG. 2 is the pin bracket 49 which carries the pins 50 and 52 of the reverse lockout mechanism 48. Also shown disposed across the park cutout 60 is a parking spring 62.
Referring now to FIG. 3, therein is shown the pivoting assembly 26 which is made up of five main assemblies: a range shift quadrant 64, a shift lever mechanism 66, a secondary pin 68, a main pivot member 70, and a speed shift quadrant 72.
The range shift quadrant 64 is provided with quadrant bearings 74 by which it pivots on the primary pivot pin 24. Below the quadrant bearings 74 are four holding slots 75 through 78 and above the quadrant bearing is a curved portion which contains at one end a collar shift range change mechanism connection 80 and at the other contains a face 82. Between the two ends is provided a shift lever slot 84 and a reverse lockout cam groove 86. The range shift quadrant 64 is provided with a boss which has a main bearing surface 88 provided thereon.
The main bearing surface 88 carries one of a pair of main bearings 90 (only one shown) by which the main pivot member 70 pivots around the primary pivot pin 24. The main pivot member 70 has two pairs of opposed range and speed flats 92 and 94 which are respectively connected by ramps 96 with the range flats 92 closer spaced than the speed flats 94. Each of the opposed speed flats 94 carry drilled countersinks 98 which are slightly offset from one another in the lateral direction as will later be explained.
The main pivot member 70 is provided with a secondary pivot bore 100 which contains a spring 102 and which pivotally carries the secondary pivot pin 68. The secondary pivot pin 68 carries the shift lever mechanism 66.
The shift lever mechanism 66 has a shift lever 104 extending vertically from the top and has arcuate range and speed bars 106 and 108 disposed to either side of secondary pin bores 110 and 112. The range and speed bars 106 and 108 respectively carry range and speed latches 114 and 116 which have a sliding fit thereon. The range and speed latches 114 and 116 are pivotally secured in the range and speed shift latch pivots 28 and 32 on the support member 12.
Between the range and speed bars 106 and 108 and the shift lever 104 are a pair of detents 118 and 120 which are intended to engage the range and speed flats 92 and 94. Each detent is made up of a ball 122 backed by an anti-friction plug 124 and a spring 126 which is held in place by a cap 128.
Below the secondary pin bores 110 is a range stop bracket 130 which has a pair of fingers 132 and 134 which are intended to engage the range stop finger 34 on the support member 12. Disposed below the range stop bracket 130 is a high/low actuator bar 136 which constantly abuts a high/low lever 138 which may best be seen by reference to FIG. 4.
The high/low lever 138 contains a high/low change hydraulic valving connection 140 at one end beneath a high/low lever surface 142 against which the high/low actuator bar 136 abuts. The high/low lever 138 is pivotable about a high/low pin 144 which is disposed in the high/low pivot 30 on the support member 12. The high/low lever 138 further has an upright portion 146 which is abutted by the high/low actuator bar 136 in order to cause pivotation of the high/low lever 138.
Referring back to FIG. 3, therein is shown the park lockup bracket 148 which is disposed longitudinally in front of the shift lever 104.
Referring now to the main pivot member 70, the other of the main bearings 90 pivots on a main bearing surface 150 of the speed shift quadrant 72. The speed shift quadrant 72 itself is carried by quadrant bearings 152 on the primary pivot pin 24. The bottom of the speed shift quadrant 72 is provided with a single holding slot 154 and the top portion is curved with the synchronizer pack speed change mechanism connection 156 at one end and a reverse lockout notch 158 provided at the other end. Between the two ends, there is provided a shift lever slot 160 and a parking lockup notch 162.
Referring now to FIG. 5, therein is shown the park lockup mechanism 36 in its engaged position with the park lockup bracket 148 abutting the park arm 38 to cause lifting of the park lockup connection 44 for locking up the transmission.
Referring now to FIG. 6, therein is shown a speed limiting lockout device 170 which is normally incorporated in the shift control 10 on tractors being used in some European countries where tractors must be speed limited for on the road travel between fields.
The speed limiting lockout device 170 is mounted on the park pivot pin 40 and a threaded stud 172 which is one of four studs on the guide plate 20 which secures it to the support member 12 (best seen in FIG. 1). A pivot bracket 174 pivots around the park pivot pin 40 and is provided with an adjustable bolt 176 in such a position that a full movement of the range quadrant 64 will cause an edge of the lockout face 82 to abut the head of the bolt and cause pivotation of the pivot bracket 174 (see FIGS. 6 and 7). Reverse pivotation of the range quadrant 64 allows the pivot bracket 174 to be pivoted in the opposite direction under the urging of a spring 178. The pivot bracket 174 further carries an actuator pin 180 which is welded thereto and which engages a stepped slot 182 in a lockout arm 184. The lockout arm 184 further has a lockout surface 186 which is movable to selectively block a part of the shift pattern cutout 22.
Operation
Starting from a park position, the shift lever 104 is pivoted laterally against the park spring 62, out of the park cutout 60 into a longitudinally extending vertical plane to the position shown in FIG. 1. In this position, the shift lever 104 is free to pivot about the primary pivot pin 24 without affecting the range or shift quadrant 64 or 72 because the arcuate range and speed bars 106 and 108 slide through the respective range and speed latches 114 and 116 which are in engaged positions with one of the holding slots 75 through 78 and the holding slot 154, respectively.
Assuming that the transmission is in the "B" range as shown in FIG. 2, and it is desired to shift the transmission into "A" range which is the lowest of the ranges, the shift lever 104 is pivoted laterally in a generally vertical-lateral plane into engagement with the shift lever slot 84 in the range shift quadrant 64. While this causes the speed latch 116 to pivot into deeper engagement with the holding slot 154, the pivotation of the range bar 106 around the secondary pin 68 causes the range latch 114 to move out of engagement with the holding slot 77. The shift lever 104 is then drawn longitudinally towards the "A" range position so as to cause pivotation of the range shift quadrant 64 and a downward movement of the collar shift range change mechanism connection 80 which shifts the necessary mechanism for the transmission to be placed in the "A" range.
The shift lever 104 is then moved out of the shift lever slot 84 to cause the range shift quadrant to be locked in place by the range latch 114 engaging the holding slot 78. The shift lever 104 is then pivoted to be laterally in line with the neutral cutout 58 in the shift pattern cutout 22. Lateral movement of the shift lever 104 into engagement with the shift lever slot 160 then causes the speed latch 116 to pivot out of engagement with the holding slot 154.
To reach the slower and reverse speeds, the shift lever 104 is pivoted so as to cause the speed change mechanism connection 156 to be lifted. Due to the nature of the transmission, it is shifted first through second speed position "2" and then by a lateral movement of the shift lever 104 into the first speed position "1". In this position, the speed change mechanism connection 156 is in a first speed position when the high/low actuator bar 136 abuts the high/low lever surface 142 to keep the high/low change hydraulic valving 138 in its down, "low" position.
The shift lever 104 is merely moved laterally to the second position "2" for the next faster speed, which causes the high/low actuator bar 136 to pivot laterally and abut the upright 146 of the high/low lever 138 so as to cause the high/low lever 138 to pivot and shift the input to the transmission to "high".
When the shift lever 104 is moved laterally to cause the high/low actuator bar 136 to cause pivotation of the high/low lever 138, positive positions will be felt because of the detents 118 and 120 provided in the shift lever mechanism 66. In the "low" position, the detent 118 engages one of the drilled counter-sink 98 so as to provide a positive position. When shifting from the "low" position, the detent 118 must be pulled out of the drilled countersink 98 and the shift lever 104 moved laterally until the detent 110 drops into the drilled countersink 98 opposite and offset from the first drilled countersink 98.
The reverse positions are reached from the first speed position "1" by longitudinally moving the shift lever 104 towards the first reverse position, "1R". Again this causes a further upward movement of the speed change mechanism connection 156 to put the transmission into "low speed reverse". A lateral shift towards the second reverse position "2R" causes the high/low actuator bar 136 to abut the upright 146 and cause the transmission to shift into reverse "high".
Similarly, from the first speed position "1", the third and fourth speed positions "3" and "4" are reached by respectively passing the shift lever 104 through the shift pattern cutout 22 laterally to the second speed position "2" and then longitudinally to the third speed position "3" and then laterally to the fourth speed position "4", respectively. It is to be noted that the shift pattern cutout 22 has a laterally inclined portion in a longitudinal direction between the second and third positions "2" and "3" so as to cause the high/low lever 138 to be shifted from its "high" position to its "low" position in being shifted from second to third speed.
Due to the configuration of the shift pattern cutout 22, it is to be noted that the shift lever 104 and the speed shift quadrant 72 must be returned to the neutral transmission position in line with the neutral cutout 58 before the shift lever 104 can be disengaged from the shift lever slot 160. This prevents any changes from being made in the transmission while the speed shift quadrant 72 indicates that the transmission should be in a speed position other than neutral.
To shift ranges, the shift lever 104 is moved laterally through the neutral cutout 58 and then longitudinally along the vertical lateral plane until it is in a position to be moved laterally into engagement with the shift lever slot 84 in the range shift quadrant 64. When the shift lever 104 is moved into the neutral cutout 58, the speed latch 116 engages the holding slot 154 to lock the speed shift quadrant 72 in place and when the shift lever 104 is engaged with the shift lever slot 84, the range latch 114 is disengaged from the holding slot 78.
A shift from the "A" range to the "B" range involves a straight longitudinal movement of the shift lever 104 until it abuts the range stop "B". While some lateral movement of the shift lever 104 is possible, it is not possible to completely disengage the shift lever 104 from the range shift quadrant 64 between ranges because the range shift latch would then abut the range shift quadrant 64 between the slots 75 through 78 rather than engaging one of them.
When the shift lever 104 is moved into engagement with the shift lever slot 84 in the shift range quadrant 64, a snap into place of the shift lever 104 will be felt as the detents 118 and 120 in the shift lever mechanism 66 ride down the ramps 96 from the speed flat 94 to the range flat 92. Conversely, when the shift lever 104 is disengaged, some effort will be required to move the detents 118 and 120 up the ramps 96 so as to provide a positive indication of a withdrawal of the shift lever 104 from the range shift quadrant 64.
To shift from the "B" range to the "C" range or from the "C" range to the "D" range it is necessary for the shift lever 104 to be moved slightly laterally to clear the range stop provided by the shift pattern cutout 22 and then to be moved longitudinally forward until again stopped by the shift pattern cutout 22. Thus it will be noted that the shift lever 104 must be moved in a double Z pattern when shifting from the range stop "B" to the range stop "D".
Since it is desirable to maintain the Z pattern for downshifting also so that an operator will always be aware of passing into a given range position, the range stop bracket 130 and the range stop finger 34 are provided.
When downshifting from the range "D", the shift lever 104 is movable longitudinally until it is in line with the range stop "C" at which point the finger 132 will abut the range stop finger 34 and require a lateral movement into the range stop "C" in order to allow a further downshift. Similarly, when downshifting from the "C" range to the "B" range, the finger 134 will abut the range stop finger 34 to require a lateral shift of the shift lever 104 to allow the fingers to clear.
Since the various ranges provide successively higher speeds and it is desirable to prevent operation of the tractor in reverse in some of the highest of these speeds, an automatic provision in the form of the reverse lockout mechanism 48 has been provided to prevent high speed reverse operation. In the preferred embodiment, reverse is possible only in the "A," "B," or "C" ranges. When the shift lever 104 is moved to the range stop "D", the pin 50 sliding in the reverse lockout cam groove 86 causes the pin 50 to move laterally in the lateral slot 56 to a position where it will be in line with the reverse lockout notch 158. The speed shift quadrant 72 will thus be able to be pivoted to all positions except those for reverse at which time the reverse lockout notch 158 will abut the pin 52 and prevent any further movement thereof. As obvious to those skilled in the art, a change to the reverse lockout cam groove 86 can make it operable to lock out other speed positions in other ranges as desired.
As would be obvious to those skilled in the art, a mechanism substantially identical to the reverse lockout mechanism 48 could be used to lockout higher speeds at other ranges. In some European countries, this type of mechanism is used to automatically lock out the third and fourth speeds in the range "D".
In Europe, where it is desired to limit the maximum speed at which the tractor can be operated, the speed limiting lockout device 170 is added to the shift control 10. When the range shift quadrant 64 is moved into the "D" range, an edge of the high/low lockout face 82 of the range shift quadrant 64 abuts the bolt 176 and causes the actuator pin 180 to move in the stepped slot 182 to cause rotation of the lockout arm 184 around the stud 172 so as to cause the lockout surface 186 to block the shift pattern cutout 22 at the fourth speed position "4". When an attempt is made to move the shift lever 104 laterally, the loads applied to the lockout surface 186 are directed laterally into the actuator pin 180 with no component which would allow the pivot bracket 174 to pivot the actuator pin 180 from its position in the step in the stepped slot 182. The actuator pin 180 will only move when the range shift quadrant 68 is moved from "D" range and the spring 178 causes the pivot bracket 174 to pivot.
When the vehicle is stopped and it is desired to place the transmission in park, the shift lever 104 is again moved into the vertical longitudinally extending plane and then pivoted longitudinally until it abuts the park cutout 60 at which time the parking spring 62 will urge the shift lever 104 laterally into the park position "P". The park lockup bracket 148 will remain in contact with the park arm 38 throughout its entire lateral movement. In this position, the shift lever 104 engages the park lockup notch 162 so as to prevent the speed shift quadrant 72 from being moved from its neutral position. Further, as shown in FIG. 5, the park lockup bracket 148 will abut the park arm 38 causing it to pivot and lift the park lockup connection 44 so as to lock up the transmission. While a complex park lockup mechanism has been shown with a four bar linkage, it is to be understood and will be obvious that this was done strictly to meet force requirements and would not be normally necessary if lower force requirements occur with other transmissions.
While the invention has been described in conjunction with a specific embodiment, it is to be understood that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations which fall within the spirit and scope of the appended claims. | A shift control for a hydromechanical transmission includes a support member having a primary pivot pin carrying side-by-side longitudinally exending range and speed shift quadrants respectively connectible to the transmission to change ranges and speeds. A shift mechanism with a vertically extending shift lever pivots laterally on a main pivot member which is pivotable around the primary pivot pin to allow longitudinal pivotal movement of the shift lever. A guide plate contains a shift pattern cutout in which the shift lever is laterally movable from a neutral position in which latches in the shift lever mechanism prevent both quadrants from moving to a range or speed shift quadrant engaged position where one of the latches respectively releases the range or speed shift quadrant to allow pivotation thereof upon longitudinal movement of the shift lever. The shift pattern cutout is provided with stop cutouts to require a Z shifting pattern to shift between ranges in one direction of longitudinal movement and the shift lever mechanism cooperates with the support member to require the same Z pattern in the opposite direction of longitudinal pivotation. The shift pattern cutout further requires that the speed shift quadrant be in the neutral position for engagement with the shift lever. A high/low lever pivotable by lateral movement of the shift lever mechanism along with longitudinal movement of the shift lever to cause pivotation of the speed shift quadrant provides additional speed shifting. Lockout devices utilizing a cam follower mechanism and a lever arm mechanism operating off the range shift quadrant respectively prevent reverse operation and of certain speeds in predetermined ranges. | 5 |
This is a continuation-in-part of application Ser. No. 308,924 filed Oct. 5, 1981, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for heating limited parts of a human body and more particularly to an ultrasound hyperthermia applicator capable of uniformly heating relatively large volumes locally without scanning.
Hyperthermia is a name which has come to mean high temperature in humans induced with therapeutic intent. Its application to cancer therapy is based on the discovery that malignant cells are generally more sensitive to heat than are normal cells. Physical techniques for hyperthermia include metabolic heat containment, heating by radio frequency or microwave energy absorption, conduction through the skin such as by a hot water bath, and perfusion of externally heated blood, heated intravenous fluids and anesthetic gases, but ultrasound is well known to offer advantages in that it has good penetration in tissue and that ultrasound heating can be focused and localized. The latter characteristic is particularly important because serious damage to healthy tissue and skin in the surrounding region must be avoided. For a given fixed frequency of ultrasound, however, the focal volume size for a single coherent focused transducer cannot be changed so that the treatment of a volume larger than the inherent focal size has previously been done by scanning, but scanning results in a high peak to average power ratio, and also introduces the complex problem of rapidly and accurately scanning the region to be heated.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an apparatus for heating a tissue volume deep within a patient without the necessity of scanning.
It is another object of the present invention to provide an ultrasound hyperthermia applicator capable of generating a variety of heating patterns by selection of frequency and the effective diameter and focal length of the individual coherent transmitter elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows qualitatively how an incoherent superposition of two individually coherent and individually focused beams can produce the effect of uniformily heating an extended region.
FIG. 2 shows schematically how an incoherent array of individually coherent beams individually focused on a target plane can have a point of maximum heat intensity some distance away from the target plane.
FIG. 3 shows schematically the spiral focusing method embodying the present invention according to which an incoherent superposition of individually coherent beams individually focused on a target plane does not result in any undesired points of increased heat intensity outside the target volume.
FIGS. 4a, 4b and 4c show examples of how individual transducers can be arranged on a plane so that they can be driven according to various grouping schemes.
DETAILED DESCRIPTION OF THE INVENTION
Stated briefly, the basic principle upon which the present invention relies is that uniform heating becomes possible by incoherent superposition of two coherent ultrasound beams in the far field. Any coherent ultrasound beam in the far field has a transverse intensity profile as shown by Curve A of FIG. 1. If another such coherent beam shown by Curve B is incoherently superposed, the resultant profile is shown by Curve (A+B) which rises and falls as rapidly as Curves A and B, but remains relatively constant over an extended distance. Thus, it is theoretically possible to obtain almost any resultant pattern of power level by superposition of many incoherent beams in this manner. This must be done, however, so that their beam center lines will not intersect outside the treatment volume because such intersection point will represent a position of maximum heat intensity. Referring now to FIG. 2 which schematically shows a typical example whereby such point of maximum intensity occurs outside the treatment volume, four transmitter elements 11, each having a finite effective beam diameter shown by a circle, are placed in an approximately square formation on transducer plane 12 some distance away from and directly facing the target area 15, that is, the line 16 through the center of the square formation and normal to transducer plane 12 will also pass through the center 19 of and is perpendicular to the plane of target area 15. Four focal points 21 are selected on target area 15 in an approximately square formation so that they are not only at a same distance from line 16, but also at the same azimuthal angles with respect to line 16 as the transmitter elements 11.
Each of the transmitter elements 11 is a source of coherent beams and is focused at the nearest of the focal points 21, or that focal point which is at the same azithumal angle as the transmitter element itself with respect to line 16. This focusing scheme is illustrated in FIG. 2 by means of representative beams from each element 11 including beam center line 25. The four transmitter elements 11 are focused incoherently with respect to one another, but this scheme for incoherent superposition of individually coherent beams is not satisfactory because the four beam center lines 25 intersect one another on line 16 at point 26. This will turn out to be a point of maximum heat intensity and it is likely that this point may lie outside the target volume.
The present invention is addressed to the problem of eliminating this difficulty. Referring now to FIG. 3 illustrating the spiral focusing scheme of the present invention by a simple example, components corresponding to those of FIG. 2 are given like reference numerals. Four transmitter elements 11' are positioned opposite to, and four focal points 21' are selected on target area 15' in an identical manner as in FIG. 2, but each of the transmitter elements 11' is focused not on the nearest of the focal points 21' (i.e., the one at the same azimuthal angle with respect to the center line 16' as the transmitter element), but on the one displaced therefrom by 90° counterclockwise (seen from above). As a result, the four beam center lines 25' are now in a spiral-like formation and hence are prevented from intersecting one another. In fact, FIG. 3 indicates that the position of maximum intensity is spread over the target area itself.
As one of the preferred embodiments of the present invention based on the principle described above, FIG. 4(a) shows 36 transducer elements 13 which are brazed to base plate 12" into a regular hexagonal shape in such a way that the lines connecting the centers of the mutually adjacent circles, each representing the effective diameter of the beams from a transducer element, form a closely packed matrix of equilateral triangles. RF power at fundamental or high resonant mode frequencies, dependent on the depths of treatment, can be matched to each transducer element via a multitrap toroidal impedence transformer (not shown). Each of elements 13 may be individually focused, or alternatively a group of several adjacent transducers can be made to act as a coherent transmitter element of a larger effective diameter. In FIGS. 4(a) and (c), two such examples are shown wherein transducers marked by the same numeral are to form a single transmitting element (e.g., 11 of FIG. 2) while transducers marked by differential numerals are emitters of beams for incoherent superposition. FIG. 4(b) shows a mode in which 8 of the 36 available transducers are not activated and the remaining transducers are divided into 4 groups (transmitting elements) of 7 (transducers) each, approximating the situation shown in FIG. 3. FIG. 4(c) shows another example of grouping whereby the 36 transducers are divided into 12 groups (transmitting elements) of 3 (transducers) each.
The beams from each transmitter element thus formed by a single transducer (as in FIG. 4(a)) or a group of transducers (as in FIGS. 4(b) and (c)), are focused at a selected target point according to a scheme as illustrated in FIG. 3.
According to the spiral focusing scheme which embodies the present invention, a target area (like 15' of FIG. 3) with a finite effective diameter is selected and the base plate 12" is positioned directly opposite to it some distance away so that a central line normal to both the base plate and the target area is definable (as line 16' of FIG. 3). Beams from each transmitter element are focused at a particular target point on the target plane in such a way that (1) these target points describe on the target plane a pattern which is similar (in the sense of the word used in geometry), but rotated around the central normal line by a fixed angle with respect to the pattern formed on the plane of base plate by the centers of the effective beam diameters of the transmitter elements and that (2) each beam center line (like 25' of FIG. 3) connects corresponding points of the two similar patterns. Stated in another way, beams from a transmitter element whose center is at distance R from and at azimuthal angle A (with respect to a fixed reference direction) around the central normal line defined above are focused on the target plane at a point at distance rR from and at azimuthal angle A+Z where r is a predetermined multiplicative factor less than unity and Z is a fixed angle (of spiral rotation).
As a result of the focusing scheme described above, the beam center lines assume a spiral-like formation around the central normal line as shown in FIG. 3. If a large number of transmitter elements are used so that their distances to the central normal lines are not uniform, the beam center lines may assume a double or multi-spiral formation. The preferred angle of rotation also changes according to the distribution of the transmitter element because it should not be so small that points of substantially enhanced heating may appear outside the target volume, while it should not be so large that beams from adjacent transmitter elements may intersect each other. In the case of four transmitter elements installed in a substantially square formation as shown in FIGS. 2, 3 or 4(b), the angle of spiral rotation (i.e., mZ) should be in the range of about 30°-150° and preferably nearly equal to 90°.
Focusing of the beams from individual elements according to any of the above-described schemes is accomplished by placing an acoustic lens (not shown) parallel to the transducer plane 12 and in front of the transducers 11. The lens is easily removable and exchangeable with another of different type so that different focusing characteristics can be obtained. A patient interface (not shown), or the surface through which the applicator may come into contact with the patient, is made of thin rubber. In order to prevent overheating of the applicator components such as the transducers, the acoustic lens and the patient interface, a system of passages (not shown) is provided for circulating a liquid such as water. The liquid can circulate both through passages between the lens and the transducers and those between the front surfaces (facing the patient) of the lens and the patient interface for efficient cooling.
The present invention has been described above in terms of only a few particular embodiments. The above description, however, is to be considered as illustrative rather than limiting. For example, the beams need not be ultrasound waves. The technique of the present invention is equally applicable to apparatus using transverse waves such as microwaves and infrared, optical or ultraviolet waves. The total number of transducers to be affixed to the base plate can be varied freely. Since the basic principle is to employ an incoherent array of individually coherent and individually focused beams, any number of such individual sources of coherent beam can be used in an applicator of the present invention. They may be affixed to their predetermined positioned by any method. Any number of individual transducers may be grouped together to form a transmitter element of the type shown in FIG. 3 (not necessarily 7 as in FIG. 4(b) or 3 as in FIG. 4(c)), and hence the size and pattern of such elements can also be varied. Any method known in the arts may be used to drive transducers within each transmitter element to emit coherent beams. The pattern according to which the centers of transmitter elements are distributed on the transducer plane need not be exactly identical to that of their foci as long as the plane of maximum heat intensity is formed substantially close to the plane of their foci for the purpose of treatment. Focusing of the beams and cooling of the device can be accomplished by any method. Passages for circulating a liquid may be provided according to any reasonable design. The scope of the invention is limited only by the following claims. | An ultrasound hyperthermia applicator comprises a plurality of transducers which can be operated in different grouping modes so that the applicator is effectively provided with a variable number of elements having variable effective diameters transmitting coherent beams. The individually coherent beams from these elements are individually focused for incoherent superposition in the target volume according to a spiral or multi-spiral focusing scheme. Such an applicator is capable of uniformly heating without scanning a limited part of human body with volume greater than the inherent focal size of the individual transmitter element. | 0 |
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to a method of manufacturing an element with a multiple-level step-like structure such as a diffractive optical element, a Fresnel lens, a phase type computer hologram (CGH), or a mask for the CGH, for example, more particularly, an element having a very fine surface-step pattern such as a diffractive optical element, for example, usable in manufacture of a semiconductor integrated circuit, for example. In another aspect, the invention is concerned with a method of manufacturing a mold for producing such an element.
Fujita, et al. (“Journal of Electronic Communication Association”, (C) J66-CP85-91, January, 1983) and Japanese Laid-Open Patent Application, Laid-Open No. 26560/1987 as well as Japanese Laid-Open Patent Application, Laid-Open No. 42102/1987 disclose a method wherein a step-like shape is formed by using an electron beam while controlling its dose quantity, and wherein a resist is used directly as a circuit pattern.
Japanese Laid-Open Patent Application, Laid-Open No. 137101/1986 discloses a method wherein two or more types of films having an etching durability are accumulated with a desired thickness, wherein the layers are etched from the top layer to provide a step-like structure, whereby a mold is formed.
Japanese Laid-Open Patent Application, Laid-Open No. 44628/1986 and Japanese Laid-Open Patent Application, Laid-Open No. 160610/1994 disclose a method wherein, while a resist is used as an etching mask, a step-like structure is formed on the basis of a sequential alignment for the steps, whereby a mold is formed.
Japanese Laid-Open Patent Application, Laid-Open No. 15510/1996 discloses a method wherein an etching stopper layer is used and, for each step, an etching stopper layer and a transparent layer are accumulated, and wherein a step-like structure is formed through alignment, exposure and etching.
Japanese Laid-Open Patent Application, No. 26339/1994 which corresponds to Japanese Laid-Open Patent Application, Laid-Open No. 72319/1995 and U.S. Pat. No. 5,324,600 disclose a method wherein an alignment operation is performed while using a resist as an etching mask, and a step-like structure is formed.
In these examples, however, the minimum size is determined by the smallest resolution of a drawing apparatus and, therefore, it is not easy to produce a very fine shape.
A multiple-level step-like diffractive optical element can be manufactured as a diffractive optical element having a step-like sectional shape, in accordance with photolithographic processes based on exposure and etching techniques that are used in semiconductor manufacture. In such a multiple-level step-like diffractive optical element, the function of a diffractive optical element is performed by step-like surface level differences (steps) formed on a substrate.
Therefore, the optical performance of the multiple-level step-like diffractive optical element, particularly, the diffraction efficiency, depends on the shape of the formed surface step, that is, depth, width, or sectional shape of the step, for example. Specifically, where plural masks are used, an alignment error between them largely influences the diffraction efficiency.
For example, where a step-like shape is to be formed by using masks of harmonic frequencies sequentially, an idealistic step-like shape can be formed if there is no alignment error or line width error. Practically, however, it is very difficult to remove the line width error or the alignment error completely and, therefore, the produced shape differs from the idealistic shape. Basically the same problem is involved in other methods.
Referring to a specific example, as shown in FIG. 70, idealistically an eight-level (step) shape can be produced by using three masks, that is, masks A, B and C. If any misregistration occurs between the masks A and B, a problem arises. FIG. 70 shows the resultant shape when there are alignment deviations d b and d c among the masks A, B and C. If the illustrated shape results, the optical performance of the optical element D such as diffraction efficiency, for example, considerably degrades.
Also, if there is a line width error at each layer, the optical performance such as diffraction efficiency further degrades. In the case of electron beam drawing, there may be no alignment error. However, a bulky drawing operation is required and, therefore, a sufficient throughput with respect to the productivity is not attainable.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved method of manufacturing an element having an accurate and very fine step-like shape.
It is another object of the present invention to provide a method of manufacturing a mode for producing an element having an accurate and very fine step-like shape.
In accordance with an aspect of the present invention, there is provided a method of manufacturing an element having a multiple-level step-like shape through plural lithographic processes, wherein a position of at least one step of the step-like shape is determined by an end of at least a portion of a pattern of a first mask to be formed through a first lithographic process of the plural lithographic processes.
In accordance with another aspect of the present invention, there is provided a method of manufacturing a mold for production of an element having a multiple-level step-like shape through plural lithographic processes, wherein a position of at least one step of the step-like shape is determined by an end of at least a portion of a pattern of a first mask to be formed through a first lithographic process of the plural lithographic processes.
In one preferred form of these aspects of the present invention, the method includes (i) a first process for etching a portion of a base material not covered by the first mask to a predetermined depth, (ii) a second process for forming a second mask so that it covers a particular region of a portion of the base material not covered by the first mask and also that it overlaps with the first mask and, subsequently, for etching the base material to a predetermined depth by using the first and second masks as an etching mask, and (iii) a third process in which, after the second mask is separated, the second process is repeated as required and, after the second mask is separated, a third mask is used to cover the portion not covered by the first mask, in which a fourth mask is formed so that an end of a pattern of the fourth mask lines at an end portion of the pattern of the first mask while an opposite end of the pattern of the fourth mask overlaps with the pattern of the third mask, and in which, after the fourth mask is formed, an exposed portion of the first mask is removed by etching so that the base material is exposed and, subsequently, the exposed portion of the base material is etched to a predetermined depth, wherein the third process is repeated at least once, as required, after the third and fourth masks are separated.
In another preferred form of these aspects of the present invention, the method includes (i) a first process for etching a portion of a base material not covered by the first mask to a predetermined depth, (ii) a second process for forming a second mask so that it covers a particular region of a portion of the base material not covered by the first mask and also that it overlaps with the first mask and, subsequently, for etching the base material to a predetermined depth by using the first and second masks as an etching mask, and (iii) a third process in which the second process is repeated as required after the second mask is separated and, after the second mask is separated, a third mask is formed so that it covers the portion not covered by the first mask and that an end of a pattern of the third mask lies at an end portion of the pattern of the first mask while an opposite end of the pattern of the third mask lies on the first mask, and in which, after the third mask is formed, an exposed portion of the first mask is etched, wherein the third process is repeated as required after the third mask is separated.
In a further preferred form of these aspects of the present invention, the method includes (i) a first process for forming a second mask so that it covers a particular region of a portion of a base material not covered by the first mask and, subsequently, for etching the base material to a predetermined depth by using the first and second masks as an etching mask to remove the second mask, (ii) a second process for repeating the first process, at least once, so that the portion of the base material not covered by the first mask is etched to a predetermined depth, and (iii) a third process in which a third mask is used to cover the portion not covered by the first mask, in which a fourth mask is formed so that an end of the fourth mask lies on the first mask while an opposite end of the pattern of the fourth mask overlaps with the third mask, and in which, after the fourth mask is formed, an exposed portion of the first mask is removed by etching so that the base material is exposed and, subsequently, the exposed portion of the base material is etched to a predetermined depth, wherein the third process is repeated as required after the third mask is separated.
In a still further preferred form of these aspects of the present invention, the method includes (i) a first process for forming a second mask so that it covers a particular region of a portion of a base material not covered by the first mask and, subsequently, for etching the base material to a predetermined depth by using the first and second masks as an etching mask to remove the second mask, (ii) a second process for repeating the first process at least once so that the portion of the base material not covered by the second mask is etched to a predetermined depth, and (iii) a third process in which a third mask is formed, after the second mask is separated, so that the third mask covers at least the portion not covered by the first mask and also that an end of a pattern of the third mask lies at an end of a pattern of the first masks while an opposite end of the pattern of the third mask lies on the first mask, and in which, after the third mask is formed, an exposed portion of the first mask is removed by etching so that the base material is exposed and, subsequently, the exposed portion of the base material is etched to a predetermined depth, wherein the third process is repeated as required after the third mask is separated.
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
FIGS. 1-19 are sectional views, respectively, for explaining the manufacturing processes in accordance with a first embodiment of the present invention.
FIGS. 20-33 are sectional views, respectively, for explaining the manufacturing processes in accordance with a second embodiment of the present invention.
FIGS. 34-46 are sectional views, respectively, for explaining the manufacturing processes in accordance with a third embodiment of the present invention.
FIGS. 47-61 are sectional views, respectively, for explaining the manufacturing processes in accordance with a fourth embodiment of the present invention.
FIGS. 62-65 are sectional views, respectively, for explaining the manufacturing processes in accordance with a fifth embodiment of the present invention.
FIG. 66 is a schematic and sectional view for explaining a reflection type element.
FIG. 67 is a schematic view of a stepper according to a seventh embodiment of the present invention.
FIG. 68 is a schematic view of a step-like diffractive optical element to be incorporated into the stepper of the seventh embodiment.
FIG. 69 is a schematic and sectional view of a step-like diffractive optical element to be incorporated into the stepper of the seventh embodiment.
FIG. 70 is a schematic view for explaining the background of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be described with reference to the drawings of FIGS. 1-69.
In a first embodiment of the present invention, as shown in FIG. 1, there is a quartz substrate 1 on which a Cr film 2 is formed by sputtering, as shown in FIG. 2, with a thickness of 1000 angstroms. For enhancement of a patterning resolution, an anti-reflection film (not shown) of chromium oxide, for example, of 200-300 angstroms, may be provided on the Cr film 2 .
Then, a photoresist is applied to the quartz substrate 1 and, through an exposure process and a development process, a first-time resist pattern is formed thereon. Subsequently, by using the resist pattern as a mask, the Cr film 2 is etched. Here, the etching process may use a parallel plane plate type RIE (reactive ion etching) apparatus, for example, and an etching gas of a chlorine gas or a mixture gas of chlorine gas and oxygen, for example.
Then, as shown in FIG. 3, the resist pattern is separated in accordance with an oxygen ashing method or by using a removing liquid, whereby a pattern of Cr film 2 is produced. Subsequently, as shown in FIG. 4, by using the Cr film pattern 2 as a mask, the quartz substrate 1 is etched. Here, the etching process may use a RIE (reactive ion etching) apparatus as described above, for example, and an etching gas of a mixture gas of CF 4 and hydrogen, for example. The etching conditions may be, for example: CF 4 flow rate is 20 sccm, hydrogen flow rate is 3 sccm, pressure is 4 Pa, and RF power is 60 W.
Thereafter, a photoresist is applied to the whole surface and, through an exposure process and a development process, patterning of it is performed as shown in FIG. 5 . Then, by using the Cr film 2 and the resist pattern 3 as a mask, the quartz substrate 1 is etched. Here, the etching process may use a RIE (reactive ion etching) apparatus as described, for example, and it may be performed in a similar manner as described above.
Subsequently, the photoresist pattern 3 is separated and, thereafter, again a photoresist pattern 4 is applied to the whole surface. Through an exposure process and a development process, the patterning of it is accomplished, as shown in FIG. 7 . Then, by using the Cr film 2 and the resist pattern 4 as a mask, the quartz substrate 1 is etched, as shown in FIG. 8 . As the photoresist pattern 4 is removed, the result such as shown in FIG. 9 is obtained.
As shown in FIG. 10, a negative type resist 5 is applied to the whole surface, and an exposure of the substrate is performed from the bottom face side of the substrate 1 . As a development process is performed, the result is such that, as shown in FIG. 11, a resist pattern 7 is formed only at a portion where no Cr film 2 is present.
Subsequently, a photoresist is applied to the whole surface, and a pattern 8 is patterned as shown in FIG. 12 . Then, as shown in FIG. 13, the portion of the Cr film 2 not covered by the pattern 7 or the pattern 8 is etched. The etching process may be performed in accordance with a RIE (reactive ion etching) method, using a chlorine gas or a mixture gas of chlorine gas and oxygen, for example.
Subsequently, as shown in FIG. 14, by using the patterns 7 and 8 as a mask, the quartz substrate 1 is etched. Thereafter, the patterns 7 and 8 are removed and, then, a negative resist is applied to the whole surface and the exposure operation is performed to the substrate 1 from its bottom face side. As a development process is performed, the result is that, as shown in FIG. 15, a resist pattern 9 is formed only in a portion where the Cr film 2 is not present. Then, a photoresist is applied to the whole surface, and a pattern 10 is patterned through an exposure process and a development process. The Cr film 2 in a portion not covered by the pattern 9 or the pattern 10 is etched in accordance with the RIE method using a chlorine gas or a mixture gas of chloride gas and oxygen, for example, such as shown in FIG. 17 .
Then, as shown in FIG. 18, by using the patterns 9 and 10 as a mask, the quartz substrate 1 is etched. Finally, the patterns 9 and 10 as well as the Cr film 2 are removed. Here, in the etching process, a liquid mixture of cerium ammonium nitrate, perchloric acid and water, for example, may be used. In this manner, a six-level step-like diffractive optical element 1 ′ such as shown in FIG. 19 is completed.
Positions a and b in this step-like diffractive optical element 1 ′ (FIGS. 3 and 19) are determined in accordance with the first patterning, independently of the alignment. Therefore, the influence of an alignment error can be significantly reduced.
Also, in this embodiment, the optical element can be manufactured at a step of one-third of the minimum resolvable line width of a drawing apparatus. Therefore, an optical element with a higher diffraction efficiency can be produced.
In this embodiment, the highest step a and the third step b therefrom are determined by the first mask. When an element with steps of a number 2 n is to be produced, the highest step a and the (n)th step b therefrom are determined by the first mask. Also, two steps (without Cr film) may be formed in a first process while three steps (with Cr film) may be formed in the subsequent process. In that case, the highest step a and the third step b therefrom are determined by the first mask.
Therefore, generally, where steps of n are to be formed in a later process (with Cr film), the highest step a and the (n)th step b therefrom are determined by a first mask.
In a second embodiment of the present invention, as shown in FIG. 20, there is a quartz substrate 11 on which a Cr film 12 is formed by sputtering, with a thickness 1000 angstroms. Here, an anti-reflection film (not shown) of chromium oxide, for example, may be provided on the Cr film 2 as desired.
Then, a photoresist is applied to the quartz substrate 11 and, through an exposure process and a development process, a first-time resist pattern 13 is formed thereon, as shown in FIG. 21 . Subsequently, by using the resist pattern 13 as a mask, the Cr film 2 is etched. Here, the etching process may use a parallel plane plate type RIE (reactive ion etching) apparatus, for example, and an etching gas of a chlorine gas or a mixture gas of chlorine gas and oxygen, for example.
Then, as shown in FIG. 22, the resist pattern 13 is separated in accordance with an oxygen ashing method or by using a removing liquid. Additionally, as shown in FIG. 23, by using the pattern of Cr film 12 as a mask, the quartz substrate 11 is etched. Here, the etching process may use a RIE (reactive ion etching) apparatus as described above, for example, and an etching gas of a mixture gas of CF 4 and hydrogen, for example. The etching conditions may be, for example, as follows: CF 4 flow rate is 20 sccm, hydrogen flow rate is 3 sccm, pressure is 4 Pa, and PF power is 60 W.
Thereafter, a photoresist is applied to the whole surface and, through an exposure process and a development process, patterning of it is performed as shown in FIG. 24 . Then, by using the Cr film 12 and the resist pattern 14 as a mask, the quartz substrate 11 is etched by a RIE apparatus, such as shown in FIG. 25 .
Subsequently, the photoresist pattern 14 is separated and, thereafter, again a negative type resist 15 is applied to the whole surface (FIG. 26 ). Then, as shown in FIG. 27, the exposure process is performed to the substrate 11 , from its bottom face side. Additionally, as shown in FIG. 28, the exposure process is performed by using a photomask 16 , from its top face side.
As a development process is performed, the result is that, as shown in FIG. 29, a photoresist pattern 17 is formed only in a portion where the Cr film 12 is not present. Then, as shown in FIG. 30, the Cr film 12 in a portion not covered by the pattern 18 is etched in accordance with the RIE method using a chlorine gas or a mixture gas of chlorine gas and oxygen, for example.
Then, as shown in FIG. 31, by using the pattern 17 as a mask, the quartz substrate 11 is etched. Subsequently, as shown in FIG. 32, the resist pattern 17 is removed and, thereafter, the Cr film 12 is removed. As a result, a four-level step-like diffractive optical element 11 ′ such as shown in FIG. 33 is completed.
Positions a and b in this step-like diffractive optical element 11 ′ (FIG. 33) are determined in accordance with the first patterning of the Cr film 12 , independently of the alignment. Therefore, the influence of an alignment error can be significantly reduced.
In a third embodiment of the present invention, as shown in FIG. 34, there is a quartz substrate 21 on which a Cr film 22 is formed by sputtering, with a thickness of 1000 angstroms. Here, an anti-reflection film (not shown) of chromium oxide, for example, may be provided on the Cr film 22 as desired.
Then, a photoresist is applied to the substrate 21 and, through an exposure process and a development process, a first-time resist pattern 23 is formed thereon, as shown in FIG. 35 . Subsequently, by using the resist pattern 23 as a mask, the Cr film 22 is etched. Here, in the etching process, a parallel plane plate type RIE (reactive ion etching) apparatus, for example, and an etching gas of a chlorine gas or a mixture gas of chlorine gas and oxygen, for example, may be used. Then, the resist pattern 23 is separated in accordance with an oxygen ashing method or by using a removing liquid.
Thereafter, a photoresist is applied to the whole surface and, through an exposure process and a development process, a resist pattern 24 such as shown in FIG. 36 is formed. Then, as shown in FIG. 37, by using the Cr film 22 and the resist pattern 24 as a mask, the quartz substrate 21 is etched. Then, the resist pattern 24 is removed (FIG. 38 ).
Subsequently, as shown in FIG. 39, by using the pattern of Cr film 22 as a mask, the quartz substrate 21 is etched by using a RIE (reactive ion etching) apparatus as described above, for example. The etching gas may be a mixture gas of CF 4 and hydrogen, for example. The etching conditions may be, for example, as follows: CF 4 flow rate is 20 sccm, hydrogen flow rate is 3 sccm, pressure is 4 Pa, and RF power is 60 W.
Thereafter, as shown in FIG. 40, a photoresist 25 is applied to the whole surface, and an exposure process is performed to the substrate 21 from its bottom face side. As a development process is performed, the result is such as shown in FIG. 41 . Then, as shown in FIG. 42, a photoresist is applied to the whole surface and, through an exposure process and a development process, a resist pattern 26 is patterned. Thereafter, as shown in FIG. 43, the Cr film 22 is etched by using a mixture liquid of cerium ammonium nitrate, perchloric acid and water, for example, while using the resist patterns 25 and 26 as a mask.
Subsequently, as shown in FIG. 44, by using the resist patterns 25 and 26 as a mask, the quartz substrate 21 is etched. Then, as shown in FIG. 45, the resist patterns 25 and 26 are removed, and the Cr film 22 is etched. Then, a four-level step-like diffractive optical element 21 ′ as shown in FIG. 46 is completed.
Positions a and b in this step-like diffractive optical element 21 ′ (FIG. 46) are determined in accordance with the first patterning of the Cr film 22 , independently of the alignment. Therefore, the influence of an alignment error can be significantly reduced.
Also, in this embodiment, the optical element can be manufactured at a step of a half of the minimum resolvable line width of a drawing apparatus. Therefore, an optical element with a higher diffraction efficiency can be produced.
In a fourth embodiment of the present invention, as shown in FIG. 47, there is a quartz substrate 31 on which a Cr film 32 is formed by sputtering, with a thickness of 1000 angstroms. Here, an anti-reflection film of chromium oxide, for example, may be provided on the Cr film 32 as desired.
Then, a photoresist is applied to the quartz substrate 31 and, through an exposure process and a development process, a first-time resist pattern 33 is formed thereon, as shown in FIG. 48 . Subsequently, by using the resist pattern 33 as a mask, the Cr film 32 is etched. Here, the etching process may use a parallel plane plate type RIE (reactive ion etching) apparatus, for example, and an etching gas of a mixture gas of chlorine gas and oxygen, for example.
Then, as shown in FIG. 49, the resist pattern 33 is separated in accordance with an oxygen ashing method or by using a removing liquid. Subsequently, a photoresist is applied to the whole surface and, through an exposure process and a development process, a resist pattern 34 such as shown in FIG. 50 is formed. Then, as shown in FIG. 51, by using the Cr film 32 and the resist pattern 34 as a mask, the quartz substrate 31 is etched.
Thereafter, the resist pattern 34 is removed (FIG. 51 ). Then, as shown in FIG. 52, by using the pattern of Cr film 32 as a mask, the quartz substrate 31 is etched. Here, the etching process may be performed in accordance with a RIE (reactive ion etching) apparatus as described above, for example, and by use of an etching gas of a mixture gas of CF 4 and hydrogen, for example. The etching conditions may be, for example as follows: CF 4 flow rate is 20 sccm, hydrogen flow rate is 3 sccm, pressure is 4 Pa, and RF power is 60 W.
Thereafter, as shown in FIG. 54, the photoresist is removed and, then, a negative type resist pattern 35 is applied to the whole surface. Then, an exposure process is performed to the substrate 31 from its bottom face side (FIG. 55 ). Also, an exposure process is performed by using a photomask 36 , from the top face side of the substrate. As a development process is performed, a resist pattern 37 such as shown in FIG. 57 is produced.
Thereafter, as shown in FIG. 58, a portion of the Cr film 32 not covered by the pattern 37 is etched, by using a mixture liquid of cerium ammonium nitrate, perchloric acid and water, for example. Subsequently, as shown in FIG. 59, by using the pattern 37 as a mask, the quartz substrate 31 is etched. Then, as shown in FIG. 60, the resist pattern 37 is removed, and the Cr film 32 is removed by etching. Then, a four-level step-like diffractive optical element 31 ′ as shown in FIG. 61 is completed.
Positions a and b in this step-like diffractive optical element 31 ′ (FIG. 61) are determined in accordance with the first Cr film 32 , independently of the alignment. Therefore, the influence of an alignment error can be significantly reduced.
Also, in this embodiment, the optical element can be manufactured at a step of a half of the minimum resolvable line width of a drawing apparatus. Therefore, an optical element of higher diffraction efficiency can be produced.
In a fifth embodiment of the present invention, a step-like diffractive optical element made of resin can be manufactured while using a step-like substrate, produced in accordance with any of the first to fourth embodiments, as a mold.
Initially, as shown in FIG. 62, a reaction setting resin, that is, ultraviolet radiation setting resin such as that of the acrylic series or epoxy series, or a thermo-setting resin, denoted at 43 , is applied by drops to a glass substrate 41 by a cylinder 42 . Subsequently, as shown in FIGS. 63 and 64, a step-like shape substrate 44 having been manufactured in accordance with any one of the first to fourth embodiments, is pressed against the resin 43 from above, whereby a replica layer 45 of the resin 43 is formed.
Here, before the substrate 44 , which functions as a mold, is pressed against the resin 43 , a mold releasing agent may be applied to the surface, as required. Subsequently, where an ultraviolet radiation setting resin is used, ultraviolet radiation is projected to the resin from the substrate (mold) 41 side, to solidify the resin. Where a thermo-setting resin is used, a heating treatment is performed to harden the resin. Subsequently, the substrate (mold) 44 is released, whereby a step-like diffractive optical element 46 as shown in FIG. 65 is completed.
Positions a and b in this step-like diffractive optical element 46 (FIG. 65) are determined in accordance with the first Cr film for the step-like substrate 44 , independently of the alignment. Therefore, the influence of an alignment error can be significantly reduced.
Also, in this embodiment, the optical element can be manufactured at a step of a half to one-third of the minimum resolvable line width of a drawing apparatus. Therefore, an optical element of higher diffraction efficiency can be produced.
In a sixth embodiment, as shown in FIG. 66, a step-like shape substrate 51 produced in accordance with any one of the first to fourth embodiments may be provided with an aluminum film 52 , formed by sputtering and with a thickness of 1000 angstroms. A reflection type step-like diffractive optical element 53 can be completed in this manner.
Positions a and b in this step-like diffractive optical element 53 (FIG. 66) are determined in accordance with the first Cr pattern for the step-like substrate 51 , independently of the alignment. Therefore, the influence of an alignment error can be significantly reduced.
Also, in this embodiment, the optical element can be manufactured at a step of a half to one-third of the minimum resolvable line width of a drawing apparatus. Therefore, an optical element of a higher diffraction efficiency can be produced.
In a seventh embodiment, a diffractive optical element as manufactured in accordance with the first embodiment may be incorporated into a semiconductor exposure apparatus (stepper), as shown in FIG. 67, which uses ultraviolet radiation such as i-line or KrF, for example.
This exposure apparatus is arranged so that a reticle 62 is irradiated with light at a wavelength 248 nm from an illumination system 61 , and a pattern formed on the reticle 62 is transferred to a semiconductor substrate 65 placed on a stage 64 , by an imaging optical system 63 , at a reduction magnification of 1:5. The imaging optical system 63 is provided with a diffractive optical element 66 having been manufactured in accordance with the method of the first embodiment, this being for the purpose of reduction of chromatic aberration and the provision of aspherical effect.
This diffractive optical element 66 may have an appearance as illustrated in a perspective view of FIG. 68 . It may have a sectional shape such as shown in FIG. 69 . Optically, it functions as a convex lens. Although FIG. 69 shows an example of four-level structure, the following description will be made on an example with an eight-level structure. The surface level difference per single step is 610 angstroms, and the width of the outermost peripheral step is 0.35 micron. The diameter of the element 66 is 120 mm.
When light is incident on the diffractive optical element 66 , it may be transmitted therethrough while being separated mainly into a first order diffraction light, ninth order diffraction light and seventeenth order diffraction light. Of course, only the first order light contributes the imaging, and it occupies 90% or more of the incident light. The remaining few percent correspond to the ninth order light and the seventeenth order light. Since these diffraction orders are considerably different from the first order light that contributes to the imaging, these diffraction lights are directed out of the imaging optical system 63 and they do not have a large influence on the imaging.
This should be compared with the optical element of FIG. 70 described above. An intense diffraction light of the third order, for example, will be produced between the first and ninth orders of light when the optical element of FIG. 70, which is manufactured by using masks A, B and C, has three levels with a 610 angstrom level difference, a 0.35 micron width at the most peripheral step and a 120 mm diameter. Such unwanted light causes flare or the like upon the image plane resulting in a large deterioration of the image performance.
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. | A method of manufacturing an element having a multiple-level step-like shape through plural lithographic processes, or a mold for production of such an element is disclosed, wherein a position of at least one step of the step-like shape is determined by an end of at least a portion of a pattern of a first mask to be formed through a first lithographic process of the plural lithographic processes. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on Japanese Patent Applications No. 2006-194527 filed on Jul. 14, 2006, and No. 2007-115581 filed on Apr. 25, 2007, the disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a semiconductor device.
BACKGROUND OF THE INVENTION
[0003] Inverter circuits for driving a load such as a motor for use in a vehicle are DC to AC converters; that is, they convert a DC voltage to an AC voltage and supply the latter to a load such as a motor. An inverter circuit for driving a motor which is inductive is composed of a MOS transistor (hereinafter abbreviated as MOS) or an insulated-gate bipolar transistor (hereinafter abbreviated as IGBT) as a switching element and a free-wheel diode (hereinafter abbreviated as FWD). The FWD bypasses and returns a current that flows through the motor while the MOS is off so that the current flowing through the motor is not varied by switching of the MOS. More specifically, when the MOS which has connected a DC power source to the motor and has applied a voltage to the motor is turned off, a current that has flown through the motor causes a reverse flow of a DC current through the FWD because of energy that is stored in the inductance L of the motor, establishing a state that is equivalent to a state that a reverse DC voltage is applied to the motor. This makes it possible to supply an AC voltage from the DC power source to the motor by switching without cutting off the motor current abruptly by switching of the MOS. To enable such an operation, the inverter circuit requires the FWD which is connected to the MOS in parallel in opposite direction. In the above inverter circuit, the MOS which functions as the switching element is required to be low in both on-resistance and switching loss. As for the FWD, the recovery characteristic and the forward loss are important characteristics.
[0004] Where a MOSFET or an IGBT which is a switching element is formed as a vertical MOS transistor having a trench gate structure (switching element), a p-type layer to serve as a channel forming region of the transistor is formed in a main-surface-side surface layer of an n-type semiconductor substrate. It is therefore possible to form a (body) diode utilizing an interface pn junction and use it as a FWD. In this structure, the vertical MOS transistor and the body diode are disposed adjacent to each other, as a result of which the semiconductor device is basically given a good switching characteristic. However, the body diode which is formed in the above manner has problems of a long recovery time and a large forward loss.
[0005] To solve the problems of the body diode which utilizes the pn-junction, the use of a Schottky barrier diode (hereinafter abbreviated as SBD) is being studied. For example, JP-A-2002-373989 (corresponding to U.S. Pat. No. 6,707,128) discloses a semiconductor device in which a vertical MOS transistor having a trench gate structure and an SBD are formed adjacent to each other on a semiconductor substrate.
[0006] FIG. 18 shows the configuration of the conventional semiconductor device disclosed in JP-A-2002-373989, that is, it is a schematic sectional view of a semiconductor device 90 . FIG. 18 shows several cells of an NMOSFET (hereinafter abbreviated as MOS) transistor having a trench gate structure and an SBD which are formed on an n + /n − substrate.
[0007] In the semiconductor device 90 of FIG. 18 , a p-type base layer 12 is selectively formed in a surface layer of an n − layer 11 of the n + /n − substrate in a MOS forming area 14 and an n + source region 13 is selectively formed in a surface layer of the p-type base layer 12 . Gate trenches are formed so as to extend in the depth direction from the surface of the n + source region 13 and to reach the n − layer 11 . An SBD forming area 28 is disposed so as to surround the p-type base layer 12 of the MOS forming area 14 continuously, for example. A guard ring region 17 is formed so as to surround the SBD forming area 28 by the same process as the p-type base layer 12 is formed.
[0008] An interlayer insulating film 19 is deposited on the substrate in the MOS forming area 14 , and plural contact holes are formed through the interlayer insulating film 19 at prescribed positions. A barrier metal 21 is formed on the surface of the n − layer 11 in the SBD forming area 28 and the surfaces of those portions of the n + source region 13 which correspond to the contact holes formed through the interlayer insulating film 19 . The barrier metal 21 is in Schottky contact with the surface of the n − layer 11 in the SBD forming area 28 and is in ohmic contact with the surfaces (high-concentration regions) of the portions of the n + source region 13 . Furthermore, a first main electrode 1 made of a metal to serve as both of an anode electrode of the SBD and a source electrode of the MOS is formed on the barrier metal 21 . A second main electrode 22 to serve as both of a cathode electrode of the SBD and a drain electrode of the MOS is formed on almost the entire chip back surface.
[0009] Configured in such a manner that the MOS and the SBD are connected to each other in parallel in opposite directions, the semiconductor device 90 of FIG. 18 can be applied to the above-described inverter circuit with the SBD used as an FWD. Having a lower threshold voltage than pn-junction diodes such as the above-described body diode, when used as the FWD, the SBD is superior in the recovery characteristic and can lower the forward loss.
[0010] On the other hand, whereas the above-described body diode is formed by utilizing the p-type layer (corresponding to the p-type base layer 12 shown in FIG. 18 ) to serve as the MOS channel forming area, in the semiconductor device 90 of FIG. 18 the independent SBD forming area 28 is provided so as to continuously surround the p-type base layer 12 which exists in the MOS forming area 14 . Therefore, the semiconductor device 90 has problems that the switching characteristic is basically bad and the chip cost is high because of an increased chip area.
[0011] One method for suppressing the increase of the chip area of the semiconductor device 90 is to increase the intervals between the gate trenches in the MOS forming area 14 and dispose an SBD between the adjoining gate trenches. However, this configuration raises another problem that the increased intervals between the gate trenches lower the breakdown voltage of the MOS. Furthermore, in this configuration, since the MOS and the SBD are disposed in a limited area, the individual regions of the p-type base layer 12 of the MOS need to be sufficiently narrow taking lateral diffusion into consideration. However, since the p-type base layer 12 of the MOS corresponds to the bases of parasitic bipolar transistors, parasitic operations tend to occur unless the individual regions of the p-type base layer 12 are sufficiently wide. This means a problem that the L load surge resistance is low.
[0012] Thus, it is desired to provide a semiconductor device in which a vertical MOS transistor having a trench gate structure and a Schottky barrier diode are formed adjacent to each other on a single semiconductor substrate, and which is superior in the diode recovery characteristic and can lower the forward loss, is free of reduction in transistor breakdown voltage and surge resistance, is superior in the switching characteristic, and is small in size and inexpensive.
[0013] FIG. 28 is a sectional view of a conventional semiconductor device which is equipped with a vertical MOSFET having a trench gate structure. As shown in FIG. 28 , an n − drift layer J 2 and a p-type base layer J 3 are formed on an n + silicon substrate J 1 . Plural n + source regions J 4 are formed in surface portions of the base layer J 3 . The silicon substrate J 1 , the drift layer J 2 , the base layer J 3 , and the source regions J 4 constitute a semiconductor substrate J 5 . Trenches J 6 are formed in the semiconductor substrate J 5 so as to penetrate through the base layer J 3 and reach the drift region J 2 . Silicon oxide films (gate oxide films) J 7 are formed so as to cover the inner wall surfaces of the trenches J 6 , respectively, and gate electrodes J 8 are formed on the surfaces of the silicon oxide films J 7 so as to be buried in the trenches J 6 , respectively. Trench gates are thus formed.
[0014] A BPSG film J 9 is formed so as to cover the gate electrodes J 8 , and a source electrode J 10 is formed so as to be electrically connected to the source regions J 4 and the base layer J 3 through contact holes that are formed through the BPSG film J 9 . A drain electrode J 11 is formed on the back-surface side of the semiconductor substrate J 5 . The semiconductor device which is equipped with the MOSFET having the trench gate structure is thus constructed (refer to JP-A-2005-333112, for example).
[0015] In the MOSFET having the above structure, since the base layer J 3 necessarily exists between the trenches, body diodes which are formed by the pn junctions of the p-type base layer J 3 and the combination of the n-type drift layer J 2 and the silicon substrate J 1 are disposed between the trenches. Where the semiconductor devices having the above structure are applied to an H-bridge circuit such as a motor drive circuit and the individual MOSFETs are on/off-driven by a PWM control, a return current flows through the body diodes of the MOSFETs located on the high side, which causes a return current loss which is mainly due to Vf of the body diodes.
[0016] Thus, it ie required for a semiconductor device to reduce a return current loss which is mainly due to Vf of a body diode.
SUMMARY OF THE INVENTION
[0017] In view of the above-described problem, it is an object of the present disclosure to provide a semiconductor device having variable operating information.
[0018] According to a first aspect, a semiconductor device includes: a semiconductor substrate having a first conductive type, wherein the substrate has a principal surface and a backside surface, and wherein the substrate includes an inner region and a periphery region; a vertical type trench gate MOS transistor disposed in a surface portion of the principal surface in the inner region of the substrate; a Schottky barrier diode disposed in another surface portion of the principal surface in the inner region of the substrate; a plurality of trenches disposed on the principal surface of the substrate; and a poly silicon film filled in each trench through an insulation film between the poly silicon film and an inner wall of the trench. The plurality of trenches have a stripe pattern without crossing each other so that the inner region on the principal surface of the substrate is divided into a plurality of separation regions by the plurality of trenches. The plurality of separation regions includes a first separation region and a second separation region. The first separation region includes a first conductive type region and a second conductive type layer disposed on the principal surface of the substrate. The second conductive type layer provides a channel region of the MOS transistor. The first conductive type region is disposed on a surface portion of the second conductive type layer, and adjacent to one trench so that the one trench provides a first trench. The first conductive type region provides a source of the MOS transistor. The poly silicon film in the first trench is coupled with a gate wiring of the MOS transistor. The plurality of trenches further includes a second trench, which is not adjacent to the first conductive type region. The poly silicon film in the second trench is coupled with a source wiring or the gate wiring of the MOS transistor. The substrate in the second separation region is exposed on the principal surface in such a manner that the substrate is coupled with the source wiring of the MOS transistor. The source wiring and the substrate in the second separation region provide a Schottky barrier in the Schottky barrier diode.
[0019] In the device, the MOS transistor and the Schottky barrier diode are reversely coupled with each other. Accordingly, the device can provide a switching element in an inverter circuit. In this case, the Schottky barrier diode has a low threshold voltage, compared with a PN junction diode. Thus, a recovery property and a forward direction loss in the Schottky barrier diode are improved.
[0020] Further, since the MOS transistor and the Schottky barrier diode are proximately arranged, so that a switching property is improved, and further, dimensions and a manufacturing cost of the device are reduced. Furthermore, by designing a width between two trenches appropriately, a withstand voltage of the MOS transistor is improved. Further, since the second conductive type layer for providing the channel region of the MOS transistor is limited to diffuse in a lateral direction of the substrate by the trench, impurity concentration is easily controlled, and a parasitic operation of a parasitic bipolar transistor is reduced so that a load surge breakdown voltage is improved.
[0021] Thus, the recovery property and the forward direction loss are improved, and the withstand voltage and the surge breakdown voltage in the transistor are also improved. Thus, the switching property in the device is improved, and the dimensions of the device are small.
[0022] According to a second aspect, a semiconductor device includes: a semiconductor substrate having a first conductive type, wherein the substrate includes a first surface and a second surface, and has a first portion and a second portion; a drift layer having the first conductive type, wherein the drift layer is disposed in a surface portion of the first surface of the substrate; a vertical MOSFET disposed in the first portion of the substrate; and an accumulation FET for operating in an accumulation mode and disposed in the second portion of the substrate. The vertical MOSFET includes: the drift layer; a base layer having a second conductive type, wherein the base layer is disposed in the drift layer; a source region having the first conductive type, wherein the source region is disposed in the base layer in such a manner that the source region is separated from the drift layer by the base layer; a first gate insulation film disposed between the source region and the drift layer through the base layer; a first gate electrode disposed on the first gate insulation film, wherein the first gate electrode provides a channel in a part of the base layer, which contacts the first gate insulation film; a source electrode electrically coupling with the source region and the base layer; and a drain electrode disposed on the second surface of the substrate. The accumulation FET includes: a second trench disposed in the drift layer; a second gate insulation film disposed on an inner wall of the second trench; and a second gate electrode disposed on the second gate insulation film in the second trench, wherein a part of the drift layer contacting the second trench is coupled with the source electrode of the vertical MOSFET.
[0023] In the above device, a return current flows through the accumulation FET instead of the MOSFET. Thus, loss caused by a Vf of a body diode is reduced.
[0024] According to a third aspect, a semiconductor device includes: a semiconductor substrate having a first conductive type, wherein the substrate includes a first surface and a second surface, and has a first portion and a second portion; a drift layer having the first conductive type, wherein the drift layer is disposed in a surface portion of the first surface of the substrate; a vertical MOSFET disposed in the first portion of the substrate; and a J-FET disposed on the second portion of the substrate. The vertical MOSFET includes: the drift layer; a base layer having a second conductive type, wherein the base layer is disposed in the drift layer; a source region having the first conductive type, wherein the source region is disposed in the base layer in such a manner that the source region is separated from the drift layer by the base layer; a first gate insulation film disposed between the source region and the drift layer through the base layer; a first gate electrode disposed on the first gate insulation film, wherein the first gate electrode provides a channel in a part of the base layer, which contacts the first gate insulation film; a source electrode electrically coupling with the source region and the base layer; and a drain electrode disposed on the second surface of the substrate. The J-FET includes: a second trench disposed in the drift layer; a second conductive type layer disposed in the drift layer and surrounding the second trench; and a second gate electrode coupled with the second conductive type layer, wherein a part of the drift layer contacting the second trench is coupled with the source electrode of the vertical MOSFET.
[0025] In the above device, a return current flows through the J-FET instead of the MOSFET. Thus, loss caused by a Vf of a body diode is reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings:
[0027] FIG. 1 shows an exemplary semiconductor device, that is, it is a schematic sectional view of a semiconductor device 100 ;
[0028] FIG. 2 is a schematic plan view showing an exemplary planar pattern of an important part of the semiconductor device 100 of FIG. 1 , and a sectional view taken along a chain line I-I in FIG. 2 corresponds to FIG. 1 ;
[0029] FIG. 3 shows another exemplary semiconductor device, that is, it is a schematic sectional view of a semiconductor device 101 ;
[0030] FIG. 4 is a schematic plan view showing an exemplary planar pattern of an important part of the semiconductor device 101 of FIG. 3 , and a sectional view taken along a chain line III-III in FIG. 4 corresponds to FIG. 3 ;
[0031] FIG. 5 shows another exemplary semiconductor device, that is, it is a schematic sectional view of a semiconductor device 102 ;
[0032] FIG. 6 is a schematic plan view showing an exemplary planar pattern of an important part of the semiconductor device 102 of FIG. 5 , and a sectional view taken along a chain line V-V in FIG. 6 corresponds to FIG. 5 ;
[0033] FIG. 7 shows another exemplary semiconductor device, that is, it is a schematic sectional view of a semiconductor device 103 ;
[0034] FIG. 8 shows another exemplary semiconductor device, that is, it is a schematic sectional view of a semiconductor device 104 ;
[0035] FIG. 9 shows still another exemplary semiconductor device, that is, it is a schematic plan view showing an exemplary planar pattern of an important part of a semiconductor device 100 a,
[0036] FIG. 10 shows another exemplary semiconductor device, that is, it is a schematic plan view showing an exemplary planar pattern of an important part of a semiconductor device 101 a;
[0037] FIG. 11 shows another exemplary semiconductor device, that is, it is a schematic plan view showing an exemplary planar pattern of an important part of a semiconductor device 102 a;
[0038] FIG. 12 shows yet another exemplary semiconductor device, that is, it is a schematic plan view showing an exemplary planar pattern of an important part of a semiconductor device 100 b;
[0039] FIG. 13 shows another exemplary semiconductor device, that is, it is a schematic plan view showing an exemplary planar pattern of an important part of a semiconductor device 101 b;
[0040] FIG. 14 shows another exemplary semiconductor device, that is, it is a schematic plan view showing an exemplary planar pattern of an important part of a semiconductor device 102 b;
[0041] FIG. 15 shows a further exemplary semiconductor device, that is, it is a schematic plan view showing an exemplary planar pattern of an important part of a semiconductor device 100 c;
[0042] FIG. 16 shows another exemplary semiconductor device, that is, it is a schematic plan view showing an exemplary planar pattern of an important part of a semiconductor device 101 c;
[0043] FIG. 17 shows another exemplary semiconductor device, that is, it is a schematic plan view showing an exemplary planar pattern of an important part of a semiconductor device 102 c;
[0044] FIG. 18 shows the configuration of a conventional semiconductor device, that is, it is a schematic sectional view of a semiconductor device 90 ;
[0045] FIG. 19 shows a sectional structure of a semiconductor device according to a second embodiment which is equipped with a DMOS having a trench gate structure;
[0046] FIG. 20A is a schematic sectional view showing a wiring form of the semiconductor device of FIG. 19 , and FIG. 20B shows its exemplary planar pattern;
[0047] FIG. 21A is a circuit diagram in which the above-configured semiconductor devices each having the DMOS and an AccuFET are provided on the high side of an H-bridge circuit for motor driving;
[0048] FIG. 21B is a timing chart showing voltages applied to the gate electrodes of the semiconductor devices located on the high side and voltages applied to the gate electrodes of DMOSs that are located on the low side when motor driving is performed by a PWM-control by means of the H-bridge circuit;
[0049] FIGS. 22A to 22C are schematic diagrams showing current paths of a case that the semiconductor devices of FIG. 19 are provided on the high side of the H-bridge circuit and the DMOSs are on/off-controlled by a PWM control;
[0050] FIGS. 23A to 23G are sectional views showing a manufacturing process of the semiconductor device of FIG. 19 ;
[0051] FIG. 24 shows a sectional structure of a semiconductor device according to a third embodiment which is equipped with a DMOS having a trench gate structure;
[0052] FIG. 25A is a schematic sectional view showing a wiring form of the semiconductor device of FIG. 24 , and FIG. 25B shows its exemplary planar pattern;
[0053] FIGS. 26A to 26C are schematic diagrams showing current paths of a case that the semiconductor devices of FIG. 24 are provided on the high side of an H-bridge circuit and the DMOSs are on/off-controlled by a PWM control;
[0054] FIGS. 27A to 27H are sectional views showing a manufacturing process of the semiconductor device of FIG. 24 ; and
[0055] FIG. 28 is a sectional view of a conventional semiconductor device which is equipped with a vertical MOSFET having a trench gate structure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
[0056] FIG. 1 shows an exemplary semiconductor device, that is, it is a schematic sectional view of a semiconductor device 100 . FIG. 2 is a schematic plan view showing an exemplary planar pattern of an important part of the semiconductor device 100 of FIG. 1 , and a sectional view taken along a chain line I-I in FIG. 2 corresponds to FIG. 1 .
[0057] The semiconductor device 100 shown in FIGS. 1 and 2 is a semiconductor device in which a vertical MOS transistor (hereinafter abbreviated as MOS) having a trench gate structure and a Schottky barrier diode (hereinafter abbreviated as SBD) are formed adjacent to each other on an n-type (n − ) semiconductor substrate 30 . Although in the following example the vertical MOS transistor is an NMOSFET (n-channel metal oxide semiconductor field-effect transistor), it may be an IGBT (insulated-gate bipolar transistor) in which a p-type layer is provided on the back-surface side of the semiconductor substrate 30 .
[0058] In the semiconductor device 100 , as shown in FIG. 1 , plural buried trenches T 1 and T 2 in each of which polysilicon 32 is buried via an insulating film 31 are formed adjacent to the main surface of the semiconductor substrate 30 . The polysilicon 32 in each trench is doped so as to exhibit n + conductivity. The intervals between the buried trenches T 1 and T 2 are 2 to 5 μm, for example. Among the plural buried trenches T 1 and T 2 , the first buried trenches T 1 are buried trenches that function as gate electrodes of the MOS and the second buried trenches T 2 are buried trenches that do not function as gate electrodes of the MOS.
[0059] As shown in FIG. 2 , the plural buried trenches T 1 and T 2 are formed along plural straight lines that exist in the substrate surface and are parallel with each other. A prescribed inner region (see FIG. 2 ) adjacent to the main surface of the semiconductor substrate 30 is divided (partitioned) into plural partitioned regions R 1 and R 2 by the plural buried trenches T 1 and T 2 . An outer region which surrounds the inner region (see FIG. 2 ) is a p-type region 36 which is formed at the same time as p-type layers 33 (described later) or by a process that is separate from a process for forming the p-type layers 33 .
[0060] Among the plural partitioned regions R 1 and R 2 , the first partitioned regions R 1 are regions that are parts of the MOS and the second partitioned regions R 2 are regions that are parts of the SBD. In each first partitioned region R 1 , a p-type layer 33 to serve as a channel-forming region of the MOS is formed in a main-surface-side portion of the semiconductor substrate 30 . An n-type (n + ) region 34 as a source region of the MOS is formed in a surface portion of the p-type layer 33 adjacent to the first buried trench T 1 . On the other hand, in each second partitioned region R 2 , an n-type (n) layer 30 a which is part of the semiconductor substrate 30 is exposed in the main surface. An n-type (n + ) layer 35 to be connected to a drain (D) electrode of the MOS and a cathode electrode of the SBD which are a common electrode is formed in a back-surface-side surface layer of the semiconductor substrate 30 . Although in FIG. 1 the n-type (n + ) layer 35 is drawn so as to be thinner than the n-type (n − ) layer 30 a, the semiconductor substrate 30 may be such as to be obtained by forming a thin n-type (n − ) layer 30 a by epitaxial growth on a thick wafer as the n-type (n + ) layer 35 . In the semiconductor device 100 , the n-type (n − ) layer 30 a functions as a carrier drift layer for the MOS and the SBD.
[0061] The polysilicon in the first buried trenches T 1 which function as the gate electrodes of the MOS among the plural buried trenches T 1 and T 2 is connected to a gate (G) interconnection of the MOS. Those portions of the n-type layer 30 a which are exposed in the surface in the second partitioned regions R 2 are connected together to a source (S) interconnection of the MOS, whereby Schottky barriers of the SBD are formed in contact portions (indicated by a thick line in FIG. 1 ). In the semiconductor device 100 of FIG. 1 , the polysilicon in the second buried trenches T 2 which are not adjacent to the n-type (n + ) regions 34 (the source regions of the MOS) and do not function as gate electrodes is connected to the source (s) interconnection of the MOS.
[0062] In the semiconductor device 100 , as shown in FIG. 2 , a first metal layer M 1 which is the source (S) interconnection of the MOS is formed so as to cover the prescribed inner region from above the main surface of the semiconductor substrate 30 . A second metal layer M 2 which is the gate (G) interconnection of the MOS is formed so as to surround the first metal layer M 1 . This structure allows the first metal layer M 1 as the source interconnection to be connected to the source regions in a shortest length and also allows the first metal layer M 1 to have a large area. As a result, reduced in wiring resistance, the semiconductor device 100 can be made a large-capacity power device.
[0063] In the semiconductor device 100 , as described above, the polysilicon in the second buried trenches T 2 is connected to the source (S) interconnection of the MOS. To this end, in the semiconductor device 100 , as shown in FIG. 2 , the polysilicon in the second buried trenches T 2 is connected to the overlaid first metal layer M 1 as the source interconnection of the MOS via polysilicon layers 37 a which are formed on the semiconductor substrate 30 outside the prescribed inner region and are connected directly to the polysilicon in the second buried trenches T 2 . The polysilicon in the first buried trenches T 1 is connected to the overlaid second metal layer M 2 as the gate interconnection of the MOS via a polysilicon layer 37 b which is formed on the semiconductor substrate 30 in the outer region and is connected directly to the polysilicon in the first trenches T 1 . Portions enclosed by thick broken lines in FIG. 2 are contact portions of the first and second metal layers M 1 and M 2 .
[0064] Next, a manufacturing method of the semiconductor device 100 of FIGS. 1 and 2 will be described briefly.
[0065] First, an n-type (n − ) layer 30 a to become the drift layer is formed by epitaxial growth on an n + semiconductor substrate to become the n-type (n + ) layer 35 shown in FIG. 1 . Then, a p-type region 36 to become the outer voltage withstanding region shown in FIG. 2 is formed so as to occupy a prescribed surface portion of the n-type (n − ) layer 30 a. Then, p-type layers 33 are formed by ion implantation and thermal diffusion. Then, an oxide film to serve as a mask for formation of first buried trenches T 1 and second buried trenches T 2 is deposited by CVD at a thickness of about 1 μm. Subsequently, prescribed portions (where trenches are to be formed) of the oxide film are removed selectively by photolithography and dry etching. At this time, as shown in FIG. 2 , the patterning is performed so that second buried trenches T 2 become shorter than first buried trenches T 1 and the ends of the former are located inside those of the latter. Dry etching is then performed to form trenches (the depth of the trenches is set at 1 to 3 μm in the case of a MOS and at 4 to 6 μm in the case of an IGBT). Then, after damage elimination treatment (also serves as treatment for rounding the trench corners) such as chemical dry etching or pseudo-oxidation is performed, insulating films 31 (see FIG. 1 ) are formed by thermal oxidation. Then, polysilicon 32 doped with an impurity is buried in the trenches by CVD and deposited on the substrate 30 (alternatively, the impurity may be introduced after depositing non-doped polysilicon). Then, polysilicon layers 37 a and 37 b (see FIG. 2 ) are formed by patterning by dry etching. At this time, the polysilicon layer 37 b is formed in such a manner as to cover end portions of the first buried trenches T 1 in the gate lead-out regions of the first buried trenches T 1 . Outside the inner region (cell region), the polysilicon layers 37 a are formed by patterning so as to cover end portions of the second buried trenches T 2 . The trench mask oxide film is thereafter removed by dry etching. At this time, the patterning is performed so that the trench mask oxide film is removed only in the inner region (cell region), that is, it is not removed in the gate lead-out regions and a field region. Subsequently, p-type layers 33 to become channel forming layers of the MOS are formed in the first partitioned regions R 1 between the first buried trenches T 1 and the second buried trenches T 2 . Then, n-type (n + ) regions 34 to become source regions of the MOS are formed in surface layer portions of the p-type layers 33 in the same first partitioned regions R 1 . Then, an interlayer insulating film is formed and contact holes are formed. At this time, contact holes for connection to the source are formed over the respective polysilicon layers 37 a which cover the end portions of the second buried trenches T 2 . Then, a first metal layer M 1 and a second metal layer M 2 are formed with aluminum (Al) or the like. As a result, the polysilicon 32 in the second buried trenches T 2 is connected to the source interconnection via the contact holes. Subsequently, the wafer thickness is reduced by grinding the back surface and a back-surface drain electrode (see FIG. 1 ) is formed.
[0066] In the semiconductor device 100 of FIGS. 1 and 2 , the MOS and the SBD are formed adjacent to each other on the single semiconductor substrate 30 and are connected to each other in opposite directions. Therefore, as described above, the semiconductor device 100 can be used, as it is, as a switching device of an inverter circuit. In such a case, being lower in threshold voltage than pn-junction diodes, the SBD of the semiconductor device 100 is superior in the recovery characteristic and can reduce the forward loss.
[0067] In the semiconductor device 100 of FIGS. 1 and 2 , the MOS and the SBD are formed close to each other in the partitioned regions R 1 and R 2 , separated from each other by the buried trenches T 1 and T 2 , of the single inner region rather than in isolated, different areas as in case of the semiconductor device 90 of FIG. 18 . Therefore, the semiconductor device 100 of FIGS. 1 and 2 can be a small, inexpensive semiconductor device having a superior switching characteristic. Furthermore, properly setting, in a range of 2 to 5 the intervals between the plural buried trenches T 1 and T 2 which partition the inner region makes it possible to suppress electric field concentration on the bottom portions of the trenches during reverse biasing and to suppress reduction of the breakdown voltage of the MOS formed in the partition regions R 1 .
[0068] As for the p-type layers 33 which serve as the channel forming regions of the MOS, lateral diffusion is restricted by the buried trenches T 1 and T 2 as shown in FIG. 1 . Therefore, it is not necessary to secure margins for lateral diffusion in forming the p-type layers 33 , which contributes to reduction of the device size. Furthermore, since the impurity concentration of the p-type layers 33 can be controlled easily, reduction of the L load surge resistance can be prevented by suppressing parasitic operations of parasitic bipolar transistors.
[0069] As described above, the semiconductor device 100 of FIGS. 1 and 2 can be made a small semiconductor device in which the vertical MOS transistor having the trench gate structure and the Schottky barrier diode are formed adjacent to each other on the single semiconductor substrate 30 , and which is superior in the diode recovery characteristic and can lower the forward loss, is free of reduction in transistor breakdown voltage and surge resistance, and is superior in the switching characteristic.
[0070] The plural buried trenches T 1 and T 2 of the semiconductor device 100 are parallel with each other and straight, as a result of which breakdown voltage designing etc. are facilitated and the semiconductor device 100 is made highly reliable and inexpensive. However, semiconductor devices capable of providing the same advantages as the semiconductor device 100 does can be obtained by modifying the semiconductor device 100 . For example, the plural buried trenches may be curved; satisfactory results are obtained as long as the plural buried trenches extend along plural lines that do not intersect each other in the substrate surface.
[0071] In the semiconductor device 100 , among the plural partitioned regions R 1 and R 2 , partitioned by the plural buried trenches T 1 and T 2 , of the inner region (see FIG. 2 ), first partitioned regions R 1 are disposed on both sides of each second partitioned region R 2 . In this manner, elements of the MOS are disposed on both sides of each SBD. As a result, the time taken by carrier movements between the MOS and the SBD is shortened, whereby the semiconductor device 100 is made superior particularly in the switching characteristic. Alternatively, for example, the plural buried trenches may be curved and the arrangement of the first partitioned regions R 1 where the MOS is formed and the second partitioned regions R 2 where the SBD is formed is arbitrary.
[0072] FIG. 3 shows another exemplary semiconductor device, that is, it is a schematic sectional view of a semiconductor device 101 . FIG. 4 is a schematic plan view showing an exemplary planar pattern of the semiconductor device 101 of FIG. 3 , and a sectional view taken along a chain line in FIG. 4 corresponds to FIG. 3 . Portions of the semiconductor device 101 of FIGS. 3 and 4 are given the same symbols as corresponding portions of the semiconductor device 100 of FIGS. 1 and 2 .
[0073] Whereas the semiconductor device 101 of FIG. 3 has the same sectional structure as the semiconductor device 100 of FIG. 1 , they are different from each other in the manner of connection of the second buried trenches T 2 . In the semiconductor device 100 of FIG. 1 , the second buried trenches T 2 are connected to the source (S) interconnection of the MOS. In contrast, in the semiconductor device 101 of FIG. 3 , the second buried trenches T 2 are connected to the gate (G) interconnection of the MOS.
[0074] The polysilicon in the second buried trenches T 2 of the semiconductor device is connected to the source interconnection or the gate interconnection so that it is given the same potential (zero potential) as the polysilicon in the first buried trenches T 1 as the gate electrodes while the MOS is off. Where the second buried trenches T 2 are connected to the source (S) interconnection of the MOS as in the semiconductor device 100 of FIG. 1 , an unnecessary parasitic (gate) capacitance is less prone to be attached to the gate of the MOS than in the case where they are connected to the gate (G) interconnection. This is preferable in being able to suppress reduction of the switching speed of the MOS and to reduce the switching loss.
[0075] On the other hand, where the second buried trenches T 2 are connected to the gate (G) interconnection of the MOS like the first buried trenches T 1 , the wiring structure is simplified and hence the semiconductor device can be made smaller. For example, in the semiconductor device 101 , as shown in FIG. 4 , the polysilicon in the first buried trenches T 1 and the second buried trenches T 2 is connected to the gate (G) interconnection of the MOS via the polysilicon layer 37 b which is formed on the semiconductor substrate outside the prescribed inner region and is connected directly to the polysilicon in first buried trenches T 1 and the second buried trenches T 2 .
[0076] FIG. 5 shows another exemplary semiconductor device, that is, it is a schematic sectional view of a semiconductor device 102 . FIG. 6 is a schematic plan view showing an exemplary planar pattern of the semiconductor device 102 of FIG. 5 , and a sectional view taken along a chain line C-C in FIG. 6 corresponds to FIG. 5 . Portions of the semiconductor device 102 of FIGS. 5 and 6 are given the same symbols as corresponding portions of the semiconductor device 100 of FIGS. 1 and 2 .
[0077] In the semiconductor device 102 of FIGS. 5 and 6 , as in the semiconductor device 100 of FIGS. 1 and 2 , the second buried trenches T 2 are connected to the source (S) interconnection of the MOS. On the other hand, the semiconductor device 102 of FIGS. 5 and 6 is different from the semiconductor device 100 of FIGS. 1 and 2 in that, in each set of first partitioned regions R 1 and a second partitioned region R 2 that are adjacent to each other, the n-type (n + ) regions 34 , the p-type layers 33 , the polysilicon 32 in the second buried trenches T 2 , and the n-type (n − ) layer 30 a which are exposed in the surface of the semiconductor substrate 30 are together connected to the (first) metal layer M 1 as the source interconnection which is formed on the semiconductor substrate 30 . Therefore, in the semiconductor device 102 , forming contact portions in such a manner as to be surrounded by thick broken lines in FIG. 6 makes it unnecessary to form, as in the semiconductor device 100 (see FIG. 2 ), the polysilicon layers 37 a which are connected directly to the polysilicon in the second buried trenches T 2 .
[0078] Next, a description will be made of methods for further increasing the breakdown voltage in the semiconductor devices 100 - 102 of FIGS. 1-6 .
[0079] FIGS. 7 and 8 show other exemplary semiconductor devices, that is, they are schematic sectional views of semiconductor devices 103 and 104 . Portions of the semiconductor devices 103 and 104 of FIGS. 7 and 8 are given the same symbols as corresponding portions of the semiconductor device 100 of FIG. 1 .
[0080] In the semiconductor device 100 of FIG. 1 , the insulating film 31 of each of the buried trenches T 1 and T 2 is formed at the same thickness in the trench bottom portion and the trench side wall portions. In contrast, in the semiconductor device 103 of FIG. 7 , to increase the breakdown voltage, the insulating film 31 a of each of buried trenches T 1 a and T 2 a is thicker in the trench bottom portion than in the trench side wall portions. For example, the structure of each of the buried trenches T 1 a and T 2 a of the semiconductor device 103 of FIG. 7 can be obtained by forming an oxide film by thermal oxidation at the same thickness in the bottom portion and the side wall portions after formation of the trench and then depositing an oxide film in the trench bottom portion.
[0081] In the semiconductor device 100 of FIG. 1 , each of the buried trenches T 1 and T 2 is formed in such a manner that the radius of curvature of the trench bottom portion is equal to ½ of the trench width of the trench top portion. In contrast, in the semiconductor device 104 of FIG. 8 , to increase the breakdown voltage, each of buried trenches T 1 b and T 2 b are formed in such a manner that the radius of curvature of the trench bottom portion is larger than ½ of the trench width of the trench top portion. For example, the structure of each of the buried trenches T 1 b and T 2 b of the semiconductor device 104 of FIG. 8 can be obtained by forming a trench by anisotropic etching and then performing isotropic etching in a state that reaction products that are stuck to the trench side walls are not removed.
[0082] The break down voltage can be increased further by decreasing the width of the second buried trenches R 2 in the semiconductor devices 100 - 102 of FIGS. 1-6 .
[0083] FIGS. 9-11 show other exemplary semiconductor devices, that is, they are schematic plan views showing exemplary planar patterns of important parts of semiconductor devices 100 a - 102 a. Portions of the semiconductor devices 100 a - 102 a of FIGS. 9-11 are given the same symbols as corresponding portions of the semiconductor devices 100 - 102 of FIGS. 2 , 4 , and 6 .
[0084] As shown in FIGS. 2 , 4 , and 6 , in the semiconductor devices 100 - 102 , the width of the partitioned regions R 1 is set approximately the same as that of the partitioned regions R 2 , that is, the intervals between the adjoining ones of the straight buried trenches T 1 and T 2 which are parallel with each other are set approximately identical. In contrast, in the semiconductor devices 100 a - 102 a of FIGS. 9-11 , the width w 2 of second buried trenches R 2 a is set smaller than the width w 1 of first buried trenches R 1 a. With this measure, the breakdown voltage can be made higher than in the semiconductor devices 100 - 102 of FIGS. 2 , 4 , and 6 . The reduction in breakdown voltage due to the insertion of the second partitioned regions R 2 a (i.e., SBD), as compared with the case that the second partitioned regions R 2 a (i.e., SBD) are not provided, can thus be decreased.
[0085] FIGS. 12-14 and FIGS. 15-17 show other exemplary semiconductor devices, that is, they are schematic plan views showing exemplary planar patterns of important parts of semiconductor devices 100 b - 102 b and 100 c - 102 c, respectively. Portions of the semiconductor devices 100 b - 102 b of FIGS. 12-14 and portions of the semiconductor devices 100 c - 102 c of FIGS. 15-17 are given the same symbols as corresponding portions of the semiconductor devices 100 - 102 of FIGS. 2 , 4 , and 6 .
[0086] The semiconductor devices 100 b - 102 b of FIGS. 12-14 are different from the semiconductor devices 100 - 102 of FIGS. 2 , 4 , and 6 , respectively, in that plural third buried trenches 13 are formed so as to bridge, in a ladder-like manner, the two adjoining buried trenches T 2 that define each second partitioned region R 2 . Each second partitioned region R 2 is partitioned into plural small regions by the plural third buried trenches T 3 , which makes it possible to decrease the reduction in breakdown voltage due to the insertion of the second partitioned regions R 2 (i.e., SBD). To decrease the reduction in breakdown voltage, it is preferable that the plural small regions be approximately square as shown in FIGS. 12-14 .
[0087] In addition to decreasing the reduction in breakdown voltage, the third buried trenches T 3 can be used for preventing lateral diffusion toward the second partitioned regions R 2 in forming the outer p-type region 36 as well as for increasing the contact areas of the polysilicon in the buried trenches T 2 and the polysilicon layers 37 a or the polysilicon layer 37 b which are or is formed on the substrate. In the semiconductor devices 100 c - 102 c of FIGS. 15-17 , third buried trenches T 3 a that are formed at the ends of the respective second partitioned regions R 2 are used for preventing lateral diffusion toward the second partitioned region R 2 in forming the outside p-type region 36 . In the semiconductor devices 100 c and 101 c of FIGS. 15 and 16 , third buried trenches T 3 b that are located right under the respective polysilicon layers 37 a or the polysilicon layer 37 b are used for increasing the contact areas of the polysilicon in the buried trenches T 2 and the polysilicon layers 37 a or the polysilicon layer 37 b which are or is formed on the substrate.
[0088] In the semiconductor devices 100 - 104 , 100 a - 102 a, 100 b - 102 b, and 100 c - 102 c of FIGS. 1-17 , the n-type (n − ) semiconductor substrate 30 is used and the p-type layers (P) 33 to serve as the channel forming regions of the MOS and the portions of the n-type layer 30 a to form the Schottky barriers of the SBD are formed in main-surface-side surface portions. For the MOS as the component of each of the semiconductor devices 100 - 104 , 100 a - 102 a, 100 b - 102 b, and 100 c - 102 c to exhibit good characteristics, it is preferable to employ the conductivity types of the individual portions of the semiconductor devices 100 - 102 of FIGS. 1 , 3 , 5 . Alternatively, semiconductor devices are possible in which the conductivity types of all the individual portions are reversed from those of the semiconductor devices 100 - 104 , 100 a - 102 a, 100 b - 102 b, and 100 c - 102 c.
[0089] As described tin the above examples, the semiconductor device is a semiconductor device in which a vertical MOS transistor having a trench gate structure and a Schottky barrier diode are formed adjacent to each other on a single semiconductor substrate, and which is superior in the diode recovery characteristic and can lower the forward loss, is free of reduction in transistor breakdown voltage and surge resistance, is superior in the switching characteristic, and is small in size and inexpensive.
[0090] As such, the semiconductor device can be used suitably as a semiconductor device which is an inverter circuit that is a combination of a vertical MOS transistor and a free-wheel diode (FWD). In this case, the Schottky barrier diode serves as the FWD.
[0091] Being small in size and capable of securing a high breakdown voltage, the semiconductor device is suitably used as a vehicular semiconductor device.
Second Embodiment
[0092] A second embodiment will be hereinafter described. FIG. 19 shows a sectional structure of a semiconductor device according to this embodiment which is equipped with a DMOS having a trench gate structure. FIG. 20A is a schematic sectional view showing a wiring form of the semiconductor device of FIG. 19 , and FIG. 20B shows its exemplary planar pattern. The configuration of the semiconductor device according to the embodiment will be described below with reference to FIG. 19 and FIGS. 20A and 20B .
[0093] The semiconductor device according to the embodiment is configured in such a manner that a DMOS having a trench gate structure and an AccuFET are formed adjacent to each other in a single chip. The AccuFET is a field-effect transistor which operates in an accumulation mode, that is, a MOSFET which is used for controlling a current flowing between trench by adjusting the widths of depletion layers formed between the trenches (refer to U.S. Pat. No. 4,903,189, for example).
[0094] As shown in FIG. 19 , an n − drift layer 202 is formed on an n + silicon substrate 201 . P-type base layers 203 are formed in portions of the drift layer 202 from its surface to a prescribed position in the depth direction in regions where a DMOS is formed (hereinafter referred to as “DMOS forming regions”). In the DMOS forming regions, plural n + source regions 204 are formed in surface portions of the base layer 203 so as to be separated from the drift layer 202 by the base layer 203 . The silicon substrate 201 , the drift layer 202 , the base layer 203 , and the source regions 204 constitute the semiconductor substrate 205 .
[0095] In each DMOS forming region of the semiconductor substrate 205 , a first trench 206 a is formed so as to penetrate through the source regions 204 and the base layer 203 and reach the drift layer 202 . In the region where the AccuFET is formed (hereinafter referred to as “AccuFET forming region”), second trenches 206 b are formed at the same depth and width as the first trenches 206 a formed in the DMOS forming regions. Each side wall of the first trench 206 a in each DMOS forming region consists of walls of the base layer 203 and a source region 204 . On the other hand, one or both of the side walls of each second trench 6 b in the AccuFET forming region are walls of only the drift layer 202 rather than walls of the base layer 203 and a source region 204 .
[0096] A silicon oxide film (gate insulating film) 207 a or 207 b is formed in each of the first and second trenches 206 a and 206 b. Each silicon oxide film 207 a or 207 b is formed so as to cover the inner wall surfaces of the first trench 206 a or the second trench 206 b and to be in contact with the portion(s), located between the source region 204 and the drift layer 202 , of the base layer 203 . A gate electrode 208 a or 208 b is formed on the surface of each silicon oxide film 207 a or 207 b so as to be buried in the first trench 206 a or the second trench 206 b. The trench gates are thus formed.
[0097] A BPSG film 209 is formed so as to cover the gate electrodes 208 a and 208 b. A source electrode 210 is formed so as to be electrically connected to the source regions 204 and the base layers 203 in the DMOS forming regions and the portion of the drift layer 202 in the AccuFET region through contact holes 209 a that are formed through the BPSG film 209 . A drain electrode 211 is formed on the back-surface side of the semiconductor substrate 205 .
[0098] In the semiconductor device having the above sectional structure, as shown in FIG. 20A , the gate electrodes 208 a and the gate electrodes 208 b are electrically connected to different gate interconnections 212 a and 212 b in cross sections that are different from FIG. 19 . More specifically, as shown in FIG. 20B , the first trenches 206 a and the second trenches 206 b extend in the same direction in the form of stripes. One (in this embodiment, the first trenches 206 a ) of the first trenches 206 a and the second trenches 206 b project from the tips of the other (in this example, the second trenches 206 b ), and the gate electrodes 208 a and the gate electrodes 208 b are electrically connected to the different gate interconnections 212 a and 212 b via gate contact holes 9 b and gate contact holes 209 c that are formed through the BPSG film 209 , respectively. To facilitate understanding of the layout of the gate interconnections 212 a and 212 b, the gate interconnections 212 a and 212 b are hatched in FIG. 20B though it is not a sectional view.
[0099] The semiconductor device according to the embodiment which is equipped with the DMOS having the trench gate structure and the AccuFET are constructed in the above-described manner. The structure can thus be obtained in which no body diode is formed in the region other than the DMOS forming regions, that is, in the AccuFET forming region.
[0100] Next, a description will be made of the operation of the above-configured semiconductor device which is equipped with the DMOS having the trench gate structure and the AccuFET. FIG. 21A is a circuit diagram in which the above-configured semiconductor devices TR( 1 ) and TR( 2 ) each having the DMOS and the AccuFET are provided on the high side of an H-bridge circuit for motor driving. FIG. 21B is a timing chart showing voltages applied to the gate electrodes 8 a and 8 b and voltages applied to the gate electrodes of DMOSs that are located on the low side when motor driving is performed by a PWM-control by means of the H-bridge circuit. In FIGS. 21A and 21B , symbols G 1 and G 2 denote the gate electrodes 8 a of the DMOS and the gate electrodes 208 b of the AccuFETs, respectively, of each of the high-side semiconductor devices TR( 1 ) and TR( 2 ). Symbol G denotes the gate electrodes of each of low-side semiconductor devices TR( 3 ) and TR( 4 ). The waveforms correspond to a case that the AccuFETs are of a normally-off type. Although the gate electrodes 208 a of the semiconductor device TR( 2 ) are kept at the low level, they may be supplied with the same waveform as the gate electrodes 208 b are supplied.
[0101] FIGS. 22A to 22C are schematic diagrams showing current paths of a case that the semiconductor devices of FIG. 19 are arranged as shown in FIG. 21A and the DMOSs are on/off-controlled by a PWM control. FIG. 22A shows energization current paths of the DMOS of the semiconductor devices TR( 1 ) or TR( 2 ), FIG. 22B shows return current paths of the DMOS of the semiconductor devices TR( 1 ) or TR( 2 ), and FIG. 22C shows current paths when the DMOS is off.
[0102] Assume a case that the semiconductor devices according to the embodiment are provided on the high side of the H-bridge circuit as shown in FIG. 21A and that an energization current flow as indicated by arrows in FIG. 22A and a return current flow as indicated by broken-line arrows in FIG. 22B . Energization is started by switching the voltage applied to the gate electrodes 208 a of the DMOS of the semiconductor device TR( 1 ) (shown at the top-left position in FIG. 21A ) from low to high as shown in FIG. 21B . At this time, the voltage of the gate electrodes 208 b of the AccuFET of the TR( 1 ) is set at the low level. The gate voltage of the low-side semiconductor device TR( 4 ) which is diagonally opposite to the semiconductor device TR( 1 ) is switched repeatedly between the high level and the low level. The voltage applied to the gate electrodes 208 b of the AccuFET of the other high-side semiconductor device TR( 2 ) is switched repeatedly between the low level and the high level in a phase that is approximately opposite to the phase of the gate voltage applied to the low-side semiconductor device TR( 4 ) though dead times exist. A return period starts when the gate voltage applied to the DMOS of the semiconductor device TR( 4 ) is switched from high to low. The operations shown in FIGS. 22A and 22B are performed in the energization period and the return period, respectively.
[0103] First, as shown in FIG. 22A , during the energization period, a voltage is applied to the gate electrodes 208 a of the semiconductor device TR( 1 ), whereby channels are formed in the base layers 203 that are in contact with the silicon oxide films 207 a and hence the DMOS is turned on. While this DMOS is on, a current flows from the drain electrode 211 to the source electrode 210 as indicated by arrows in FIG. 22A . During the return period when the DMOS of the semiconductor device TR( 4 ) is switched from on to off, as shown in FIG. 22B a current flows in the direction opposite to the direction in the energization period, that is, from the source electrode 210 to the drain electrode 211 . At this time, since the AccuFET is provided in addition to the DMOS and the voltage applied to the gate electrodes 208 b of the AccuFET of the semiconductor device TR( 2 ) is switched from low to high, a return current flows through the AccuFET but almost no return current flows through the DMOS. As a result, the loss that is mainly due to Vf of the body diodes can be reduced.
[0104] When the flow of the return current is finished after the DMOS of the semiconductor device TR( 4 ) was switched from on to off, as shown in FIG. 22C the portion of the drift layer 202 between the second trenches 206 b of the AccuFET is pinched off by depletion layers extending from the second trenches 206 b into the drift layer 202 and the current path leading to the drift layer 202 is interrupted. In this manner, current flow can be prevented while the DMOS and the AccuFET are off. Current leakage can thus be prevented while the AccuFET is off.
[0105] As described above, the semiconductor device according to the embodiment is configured in such a manner that not only the DMOS but also the AccuFET is formed in the single chip. Therefore, a return current is allowed to flow through the AccuFET rather than the DMOS, which provides the advantage that the loss that is mainly due to Vf of the body diodes can be reduced.
[0106] Next, a manufacturing method of the above-configured semiconductor device will be described with reference to sectional views of FIGS. 23A to 23G showing a manufacturing process of the semiconductor device according to the embodiment.
[0107] First, in a step of FIG. 23A , an n + silicon substrate 201 is prepared and an n − drift layer 202 is formed on the silicon substrate 201 by epitaxial growth. Then, a silicon oxide film 220 to become a first mask is deposited by CVD and then patterned by photolithography and dry etching, whereby openings are formed through the silicon oxide film 220 . Then, first and second trenches 206 a and 206 b are formed in the DMOS forming regions and the AccuFET forming region by anisotropic dry etching with the thus-patterned silicon oxide film 220 used as a mask.
[0108] In a step of FIG. 23B , the silicon that forms the first and second trenches 206 a and 206 b is etched isotropically by about 0.1 μm by chemical dry etching using a CF 4 or O 2 gas. Then, pseudo-oxide films are formed by thermal oxidation in an H 2 O or O 2 atmosphere. The pseudo-oxide films are thereafter removed by wet etching using diluted hydrofluoric acid, whereby etching damage is eliminated and the corner portions of the first and second trenches 206 a and 206 b are rounded. Then, thermal oxidation is performed again in an H 2 O or O 2 atmosphere, whereby silicon oxide films 207 a and 207 b are formed.
[0109] In a step of FIG. 23C , doped polysilicon films for formation of gate electrodes 8 a and 208 b are formed by LPCVD and then etched back so as to have a desired thickness. Naturally, instead of forming doped polysilicon films, an impurity may be introduced after depositing non-doped polysilicon films. Subsequently, the doped polysilicon films are patterned into gate electrodes 208 a and 208 b. Trench gates are thus completed.
[0110] In a step of FIG. 23D , the silicon oxide film 220 as the first mask is removed. As a result, the drift layer 202 is exposed except in the trench gates.
[0111] In a step of FIG. 23E , after an ion implantation mask etc. are formed if necessary, the regions other than the regions where base layers 203 will be formed are covered with a second mask. In this state, p-type impurity ions are implanted, whereby base layers 203 are formed in the DMOS forming regions. Then, after the second mask is removed, the regions other than the regions where source regions 204 will be formed are covered with a third mask. In this state, n-type impurity ions are implanted, whereby source regions 204 are formed in the DMOS forming regions.
[0112] In a step of FIG. 23G , a BPSG film 209 is formed as an interlayer insulating film on the entire surface of the semiconductor substrate 205 and then etching is performed by using a fourth mask (not shown), whereby contact holes 209 a are formed through the BPSG film 209 (contact holes 209 b and 209 c (not shown) are also formed at the same time). The fourth mask is removed thereafter.
[0113] In a step of FIG. 23G , a metal film is formed on the BPSG film 9 and patterned, whereby a source electrode 210 is formed which is connected to the source regions 204 and the base layers 203 in the DMOS regions and is connected to the drift layer 202 in the AccuFET region and gate interconnections that are electrically connected to the gate electrodes 208 a and the gate electrodes 208 b in cross sections that are different from FIG. 23G are formed.
[0114] In subsequent manufacturing steps which are not shown in any drawings, the thickness of the silicon substrate 201 is reduced by grinding its back surface and a metal layer as a drain electrode 211 is formed on the back surface. The semiconductor device of FIG. 19 in which the DMOS having the trench gate structure and the AccuFET are formed is completed.
Third Embodiment
[0115] FIG. 24 shows a sectional structure of a semiconductor device according to this embodiment which is equipped with a DMOS having a trench gate structure. FIG. 25A is a schematic sectional view showing a wiring form of the semiconductor device of FIGS. 24 , and 25 B shows its exemplary planar pattern. The semiconductor device according to this embodiment is different from that according to the second embodiment only in that a J-FET is provided in place of the AccuFET. Therefore, only features that are different than in the second embodiment will be described.
[0116] The semiconductor device according to the embodiment is configured in such a manner that a DMOS having a trench gate structure and a J-FET are formed adjacent to each other in a single chip.
[0117] As shown in FIG. 24 , second trenches 206 c are formed in a J-FET forming region by digging the drift layer 202 from its surface. A p-type layer 213 is formed in a portion having a prescribed width around the inner wall surface of each second trench 206 c, that is, in a portion of the drift layer 202 that surrounds each second trench 206 c. Gate electrodes 208 c are formed so as to be buried in the respective second trenches 206 c.
[0118] In the semiconductor device having the above sectional structure, as shown in FIG. 25A , the gate electrodes 208 a and the gate electrodes 8 c are electrically connected to different gate interconnections 212 a and 212 c in cross sections that are different from FIG. 24 . More specifically, as shown in FIG. 25B , the first trenches 206 a and the second trenches 206 c extend in the same direction in the form of stripes. One (in this embodiment, the first trenches 206 a ) of the first trenches 206 a and the second trenches 206 c project from the tips of the other (in this example, the second trenches 206 c ), and the gate electrodes 208 a and the gate electrodes 208 c are electrically connected to the different gate interconnections 212 a and 212 c via gate contact holes 209 b and gate contact holes 9 d that are formed through the BPSG film 209 , respectively. To facilitate understanding of the layout of the gate interconnections 212 a and 212 c, the gate interconnections 212 a and 212 c are hatched in FIG. 25B though it is not a sectional view.
[0119] The semiconductor device which is equipped with the DMOS having the trench gate structure and the J-FET are constructed in the above-described manner. The structure can thus be obtained in which no body diode is formed in the region other than the DMOS forming regions, that is, in the J-FET forming region.
[0120] Next, the operation of the above-configured semiconductor device which is equipped with the DMOS having the trench gate structure and the J-FET will be described by using a circuit in which the semiconductor devices having the J-FET according to the embodiment and semiconductor devices having only a DMOS are arranged similarly to the arrangement of FIG. 21A .
[0121] FIGS. 26A to 26C are schematic diagrams showing current paths of a case that the semiconductor devices of FIG. 24 are provided on the high side of an H-bridge circuit and the DMOSs are on/off-controlled by a PWM control. FIG. 26A shows current paths when a DMOS is on, FIG. 26B shows return current paths at an instant when the DMOS is turned off, and FIG. 26C shows current paths when the DMOS is off.
[0122] First, as shown in FIG. 26A , during the energization period, a current flows from the drain electrode 211 to the source electrode 210 as indicated by arrows in FIG. 26A . During the return period when the DMOS of a low-side semiconductor device is switched from on to off, as shown in FIG. 26B a current flows in the direction opposite to the direction in the energization period, that is, from the source electrode 210 to the drain electrode 211 . At this time, since the J-FET is provided in addition to the DMOS and the voltage applied to the gate electrodes 208 c of the J-FET of the high-side semiconductor device through which a return current is to flow is switched from low to high, a return current flows through the J-FET but almost no return current flows through the DMOS. As a result, the loss that is mainly due to Vf of the body diodes can be reduced.
[0123] When the flow of the return current is finished after the DMOS was switched from on to off, as shown in Fig, 26 C the portion of the drift layer 202 between the p-type layers 213 of the J-FET is pinched off by depletion layers extending from the p-type layers 213 into the drift layer 202 and the current path leading to the drift layer 202 is interrupted. In this manner, current flow can be prevented while the DMOS and the J-FET are off. Current leakage can thus be prevented while the J-FET is off.
[0124] As described above, the semiconductor device according to the embodiment is configured in such a manner that not only the DMOS but also the J-FET is formed in the single chip. Therefore, a return current is allowed to flow through the J-FET rather than the DMOS, which provides the advantage that the loss that is mainly due to Vf of the body diodes can be reduced.
[0125] Next, a manufacturing method of the above-configured semiconductor device will be described with reference to process diagrams of FIGS. 27A to 27H . The manufacturing method of the semiconductor device according to this embodiment is the same as that according to the second embodiment as far as the process for forming the DMOS is concerned. Therefore, a process for forming the J-FET, which is different than in the second embodiment, will mainly be described below.
[0126] First, steps of FIGS. 27A to 27D are executed which are the same as the steps of FIGS. 23A to 23D according to the second embodiment. Trench gates are thereby formed in the DMOS forming regions.
[0127] In a step of FIG. 27E , a silicon oxide film 221 to become a mask is deposited by CVD on the drift layer 202 including the trench gates and then patterned by photolithography and dry etching, whereby openings are formed through the silicon oxide film 221 . Then, second trenches 6 c are formed in the drift layer 202 in the J-FET forming region by anisotropic dry etching with the thus-patterned silicon oxide film 221 used as a mask. Then, p-type layers 13 are formed so as to surround the trenches 6 c by, for example, oblique ion implantation using the silicon oxide film 221 as a mask.
[0128] In a step of FIG. 27F , gate electrodes 208 c are formed with doped poly silicon in the same manner as in the step of FIG. 23C . Then, after the silicon oxide film 221 is removed, a step that is the same as the step of FIG. 23E of the second embodiment is executed, whereby base layers 203 and source regions 204 are formed. Then, steps of FIGS. 27G and 27H are executed which are the same as the steps of FIG. 23F and 23G of the second embodiment, respectively. Finally, a drain electrode 11 is formed on the back surface of the silicon substrate 201 . The semiconductor device of FIG. 24 in which the DMOS having the trench gate structure and the J-FET are formed is completed.
Other Embodiments
[0129] Although the above embodiments are directed to the case of using the n-channel transistor having the trench gate structure, naturally the embodiments can also be applied to a case of using a p-channel transistor in which the conductivity types of the individual portions are opposite to those of the embodiments.
[0130] Although the above embodiments are directed to the case that the vertical MOSFET is a DMOS having a trench gate structure, the same advantages as described above can be obtained by forming an AccuFET or a J-FET together with a planar DMOS or an LDMOS.
[0131] The third embodiment is directed to the case that the gate electrodes 8 c of the J-FET are made of doped polysilicon. Alternatively, for example, trench gates may be formed by forming, in the drift layer 202 , trenches 206 c and p-type layers 213 surrounding the respective trenches 206 c and then forming metal layers such as tungsten plugs in the respective trenches 206 c. In this case, the metal layers may be formed with tungsten in a later step of forming interconnections.
[0132] While the invention has been described with reference to preferred embodiments thereof, it is to be understood that the invention is not limited to the preferred embodiments and constructions. The invention is intended to cover various modification and equivalent arrangements. In addition, while the various combinations and configurations, which are preferred, other combinations and configurations, including more, less or only a single element, are also within the spirit and scope of the invention. | A semiconductor device includes: a semiconductor substrate; a vertical type trench gate MOS transistor; a Schottky barrier diode; multiple trenches having a stripe pattern to divide an inner region into first and second separation regions; and a poly silicon film in each trench. The first separation region includes a first conductive type region for providing a source and a second conductive type layer for providing a channel region. The first conductive type region is adjacent to a first trench. The poly silicon film in the first trench is coupled with a gate wiring. A second trench is not adjacent to the first conductive type region. The poly silicon film in the second trench is coupled with a source or gate wiring. The substrate in the second separation region is coupled with the source wiring for providing a Schottky barrier. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 103139832 filed in Taiwan, R.O.C. on Nov. 17, 2014, the entire contents of which are hereby incorporated by reference.
FIELD OF TECHNOLOGY
[0002] The present invention relates to roller structures and manufacturing methods thereof and, more particularly, to a roller structure and a manufacturing method thereof, characterized in that a load is mounted on and thus carried by the roller structure.
BACKGROUND
[0003] Rollers enable heavy objects, such as a frame or sliding doors, drawers and shelves of a cabinet, to be easily moved. Rollers work efficiently, because of the relatively small friction between each rotating roller and its rail or a surface. However, there is still room for improvement in conventional roller structures and manufacturing methods thereof. For example, an assembly structure of a conventional roller is structurally intricate, and the assembly operation or process is complicated, thereby compromising its production efficiency. In addition, the conventional roller structures seldom match the other components in wide use, such as pivots, for modularization, and in consequence roller manufacturers have to manufacture the components and perform the subsequent time-consuming assembly process independently.
[0004] Accordingly, it is imperative to provide a roller structure and a manufacturing method thereof with a view to overcoming the aforesaid drawbacks of the prior art.
SUMMARY
[0005] In view of the aforesaid drawbacks of the prior art, the inventor of the present invention conceived room for improvement in the prior art and thus conducted extensive researches and experiments according to the inventor's years of experience in the related industry, and finally developed a roller structure and a manufacturing method thereof as disclosed in the present invention to thereby provide a modularized roller structure for carrying a load, effectuate modularized assembly and production, enhance assembly efficiency, attain structural streamlining, and cut costs.
[0006] It is an objective of the present invention to provide a roller structure and a manufacturing method thereof to thereby provide a modularized roller structure for carrying a load, effectuate modularized assembly and production, enhance assembly efficiency, attain structural streamlining, and cut costs.
[0007] In order to achieve the above and other objectives, the present invention provides a roller structure, comprising: a roller rotatable about an axial portion, an end of a bush is disposed to an end of the axial portion, and another end of the bush having an engaging portion coupled to a load; and a second stop portion disposed at another end of the axial portion and positioned proximate to a side of the roller such that the roller rotates between the second stop portion and the engaging portion.
[0008] As regards the roller structure, the bush has a first stop portion positioned proximate to another side of the roller.
[0009] As regards the roller structure, the roller comprises an axial hole which the axial portion is disposed in to enable the roller to rotate about the axial portion.
[0010] As regards the roller structure, the bush formed integrally with or coupled to the axial portion.
[0011] As regards the roller structure, the second stop portion formed integrally with or coupled to the axial portion.
[0012] As regards the roller structure, the second stop portion is formed by injection molding.
[0013] As regards the roller structure, the second stop portion is in the form of a stop component fitted around the axial portion, and the axial portion has a third stop portion for limiting movement of the stop component.
[0014] The roller structure comprises a connection component coupled to the axial portion, wherein the second stop portion is provided in the form of a stop component whose movement is limited by the connection component.
[0015] As regards the roller structure, the stop component is provided in the form of a hollow-core component penetrable by the connection component.
[0016] As regards the roller structure, a receiving chamber concentric with the axial portion is disposed on one or two sides of the roller and adapted to receive one of the first stop portion, the second stop portion and the third stop portion.
[0017] As regards the roller structure, a limiting portion is disposed on a side of the roller such that the second stop portion is confined to between the limiting portion and the roller.
[0018] As regards the roller structure, the first stop portion of the bush separates the roller and the load.
[0019] As regards the roller structure, the roller comprises one of an inner ring, a rolling component and a sliding component for fitting around the axial portion.
[0020] As regards the roller structure, a rolling surface of the roller is striped.
[0021] As regards the roller structure, the roller is made of a single-ingredient material, such as a metal, a plastic or a rubber, or a multiple-ingredient material.
[0022] As regards the roller structure, the engaging portion of the bush is positioned proximate to a side of the load such that the bush and the load are coupled together by a connection component.
[0023] The roller structure comprises a frame which the engaging portion of the bush and the load are coupled to.
[0024] As regards the roller structure, the frame is slender or plate-shaped.
[0025] As regards the roller structure, the frame is coupled to the load by a riveting mechanism, an expansion mechanism, a welding mechanism, an engaging mechanism, a fastening mechanism, an adhesion mechanism or a magnetic attraction mechanism.
[0026] As regards the roller structure, the roller and the axial portion are coupled to the bush and the second stop portion to form a module and then the engaging portion of the bush is coupled to the load.
[0027] As regards the roller structure, the roller and the axial portion are coupled to the second stop portion to form a module so as for the bush to be coupled to the load to form a module and eventually for the axial portion to be coupled to the bush.
[0028] As regards the roller structure, the engaging portion of the bush is coupled to the load by a riveting mechanism, an expansion mechanism, a welding mechanism, an engaging mechanism, a fastening mechanism, an adhesion mechanism or a magnetic attraction mechanism.
[0029] As regards the roller structure, the engaging portion of the bush has a feeding space which a material of the load is injected into via a die such that the engaging portion is coupled to the load.
[0030] As regards the roller structure, a diameter of the engaging portion is larger or smaller than a diameter of the roller.
[0031] As regards the roller structure, the feeding space faces the roller or faces away from the roller.
[0032] As regards the roller structure, the engaging portion coupled to the load via pressing the second stop portion, pressing the roller, pressing the engaging portion or pressing the first stop portion.
[0033] As regards the roller structure, the engaging portion coupled to the frame via pressing the second stop portion, pressing the roller or pressing the engaging portion.
[0034] The present invention further provides a manufacturing method of the roller structure, and the manufacturing method includes the step of forming the second stop portion positioned proximate to a side of the roller by using a die in performing a pressing process on a pressed portion at another end of the axial portion.
[0035] As regards the manufacturing method, the engaging portion of the bush is coupled to the load by a riveting mechanism, an expansion mechanism, a welding mechanism, an engaging mechanism, a fastening mechanism or a magnetic attraction mechanism.
[0036] As regards the manufacturing method, the engaging portion of the bush has a feeding space which a material of the load is injected into via a die such that the engaging portion is coupled to the load.
[0037] As regards the manufacturing method, the feeding space faces the roller or faces away from the roller.
[0038] As regards the manufacturing method, a diameter of the engaging portion is larger or smaller than a diameter of the roller.
[0039] As regards the manufacturing method, the engaging portion coupled to the load via pressing the second stop portion, pressing the roller, pressing the engaging portion or pressing the first stop portion.
BRIEF DESCRIPTION
[0040] Objectives, features, and advantages of the present invention are hereunder illustrated with specific embodiments in conjunction with the accompanying drawings, in which:
[0041] FIG. 1 is an exploded view of a roller structure according to the first preferred embodiment of the present invention;
[0042] FIG. 2 is a perspective view of the roller structure according to the first preferred embodiment of the present invention;
[0043] FIG. 3 is a cross-sectional view 1 of the roller structure according to the first preferred embodiment of the present invention;
[0044] FIG. 4 is a cross-sectional view 2 of the roller structure according to the first preferred embodiment of the present invention;
[0045] FIG. 5 is a cross-sectional view of the roller structure according to the second preferred embodiment of the present invention;
[0046] FIG. 6 is a cross-sectional view of the roller structure according to the third preferred embodiment of the present invention;
[0047] FIG. 7 is a cross-sectional view of the roller structure according to the third preferred embodiment of the present invention;
[0048] FIG. 8 is a cross-sectional view of the roller structure according to the third preferred embodiment of the present invention;
[0049] FIG. 9 is a cross-sectional view of the roller structure according to the third preferred embodiment of the present invention;
[0050] FIG. 10 is a schematic view of a manufacturing method of the roller structure according to the first preferred embodiment of the present invention;
[0051] FIG. 11 is a schematic view of the manufacturing method according to the first preferred embodiment of the present invention;
[0052] FIG. 12 is a schematic view of the manufacturing method according to the second preferred embodiment of the present invention;
[0053] FIG. 13 is a schematic view of the manufacturing method according to the second preferred embodiment of the present invention;
[0054] FIG. 14 is an exploded view of a modularized frame according to a preferred embodiment of the present invention;
[0055] FIG. 15 is a cross-sectional view of the roller structure according to the preferred embodiment of the present invention;
[0056] FIG. 16 is a schematic view 1 of the manufacturing method according to the preferred embodiment of the present invention;
[0057] FIG. 17 is a schematic view 2 of the manufacturing method according to the preferred embodiment of the present invention;
[0058] FIG. 18 is a schematic view 3 of the manufacturing method according to the preferred embodiment of the present invention; and
[0059] FIG. 19 is a schematic view 4 of the manufacturing method according to the preferred embodiment of the present invention.
DETAILED DESCRIPTION
[0060] Referring to FIG. 1 through FIG. 3 , the present invention provides a roller structure and a manufacturing method thereof, applicable to rollers. In a preferred embodiment of the present invention, the roller structure comprises a roller 1 and a second stop portion 4 . The roller 1 is adapted to carry a load 3 and made of a single-ingredient material, such as a metal, a plastic or a rubber, or a multiple-ingredient material. The roller 1 is a cylinder circumferentially provided with a rolling surface 11 for contact with any other object regardless of whether the roller 1 is rotating or not. The rolling surface 11 is either glossy or striped. When striped, the rolling surface 11 exhibits stripes which run longitudinally, transversely, obliquely or cross each other. The roller 1 is centrally provided with an axial portion 12 for driving the roller 1 to rotate. Preferably, the axial portion 12 is disposed in an axial hole 13 disposed centrally at the roller 1 such that the roller 1 rotates about the axial portion 12 . The roller 1 is coupled to a load 3 through the axial portion 12 and a bush 2 . Preferably, the bush 2 is a cylinder made of a single-ingredient material, such as a metal or a plastic, or a multiple-ingredient material. One end of the bush 2 is formed integrally with or coupled to one end of the axial portion 12 and enclosed with a first stop portion 21 adjacent to the roller 1 . The first stop portion 21 has a first stop surface 211 corresponding in position to a side of the roller 1 . Another end of the bush 2 has an engaging portion 22 . The bush 2 is coupled to the load 3 through the engaging portion 22 . The first stop portion 21 separates the roller 1 and the load 3 to thereby prevent the roller 1 from coming into contact with the load 3 ; hence, the roller 1 is rotatably disposed at the load 3 . The second stop portion 4 serves to limit disconnection-proof components or structures disposed in the axial direction of the roller 1 and, in a preferred embodiment, is formed integrally with or coupled to another end (facing away from the bush 2 ) of the axial portion 12 and positioned proximate to another side (facing away from the bush 2 ) of the roller 1 ; hence, the roller 1 rotates between the first stop portion 21 and the second stop portion 4 to therefore effectuate the roller structure of the present invention. In addition, referring to FIG. 4 , in a variant embodiment of the present invention, the roller structure is dispensed with the first stop portion 21 . Referring to FIG. 4 , an inner annular groove 18 is disposed on another side of the roller 1 to fix movably around the circumferential edge of the second stop portion 4 .
[0061] Referring to FIG. 3 , FIG. 4 , FIG. 5 and FIG. 9 , in an embodiment of the present invention, the second stop portion 4 is preferably formed at another end of the axial portion 12 by injection molding in a manner that the second stop portion 4 has a larger diameter than the axial portion 12 so as to limit the movement of the roller 1 from another side thereof. Referring to FIG. 6 , FIG. 7 or FIG. 8 , in another embodiment of the present invention, the second stop portion 4 is provided with a stop component 41 which has a larger diameter than the axial portion 12 and functions as a hollow-core component, ring, C-ring, clip, bush or bearing for use in penetrable coupling or snug engagement such that the stop component 41 is fitted around the axial portion 12 . Preferably, the axial portion 12 has a third stop portion 14 for limiting the movement of the stop component 41 . In an embodiment of the present invention, the third stop portion 14 is formed by performing a pressing process on another end of the axial portion 12 (as shown in FIG. 6 ) such that the stop component 41 is coupled to the axial portion 12 firmly. In a variant embodiment of the present invention, the third stop portion 14 is provided in the form of a head portion 51 of a connection component 5 such that a body portion 52 of the connection component 5 is coupled to the axial portion 12 and the bush 2 (shown in FIG. 7 and FIG. 8 ); hence, the movement of the stop component 41 is limited by the third stop portion 14 formed from the head portion 51 of the connection component 5 , thereby allowing the stop component 41 to be coupled to the axial portion 12 firmly.
[0062] Referring to FIG. 3 and FIG. 5 , a receiving chamber 15 concentric with the axial portion 12 is disposed on one or two sides of the roller 1 and is round, polygonal or of any appropriate geometric shape such that the first stop portion 21 , the second stop portion 4 or the third stop portion 14 is received in the receiving chamber 15 of the roller 1 to thereby prevent the first stop portion 21 , the second stop portion 4 or the third stop portion 14 from protruding from the roller 1 laterally. Referring to FIG. 7 and FIG. 8 , a limiting portion 16 is disposed on another side of the roller 1 and provided in the form of a neck portion disposed on the inner wall of the receiving chamber 15 to not only confine the second stop portion 4 to between the limiting portion 16 and the roller 1 but also prevent the roller 1 from loosening.
[0063] Referring to FIG. 6 , preferably, in an embodiment of the present invention, the roller 1 is provided with an inner ring 17 a which fits around the axial portion 12 . The inner diameter of the inner ring 17 a defines the axial hole 13 . The contact between the inner ring 17 a and the axial portion 12 enhances the mechanical strength of the roller 1 and reduces the wear and tear of the axial hole 13 . For example, when the roller 1 is made of a plastic or a rubber, the inner ring 17 a is made of a metal of high rigidity. Referring to FIG. 7 , the roller 1 is preferably provided with a rolling component 17 b for fitting around the axial portion 12 and exemplified by a ball bearing, a needle bearing or an equivalent component, wherein the inner diameter of the rolling component 17 b defines the axial hole 13 . The rolling component 17 b not only functions as well as the inner ring 17 a but is also effective in reducing the coefficient of friction between the roller 1 and the axial portion 12 to thereby enable the roller 1 to rotate smoothly. Referring to FIG. 9 , the roller 1 is preferably provided with a sliding component 17 c for fitting around the axial portion 12 and exemplified by a bush capable of self-lubrication and thus capable of bearing a heavy load and being more durable.
[0064] As indicated above, according to the present invention, the engaging portion 22 of the bush 2 enables the roller 1 to be mounted on the load 3 , and the engaging portion 22 is coupled to the load 3 by a riveting mechanism (shown in FIG. 3 ), an expansion mechanism (shown in FIG. 5 ), a welding mechanism (shown in FIG. 6 ), an engaging mechanism, a fastening mechanism or a magnetic attraction mechanism, or by any other means of fixation. Referring to FIG. 8 , the engaging portion 22 of the bush 2 is not directly coupled to the load 3 but is positioned proximate to the load 3 from one side thereof and then coupled to the bush 2 and the load 3 through a connection component 5 . Referring to FIG. 9 , the present invention is not limited to an embodiment where the first stop portion 21 of the bush 2 is formed integrally with the bush 2 ; instead, in a variant embodiment, it is also practicable that the first stop portion 21 is provided with a stop component 212 which functions as a hollow-core component, ring, C-ring, clip, bush or bearing for use in penetrable coupling or snug engagement. Likewise, one side of the stop component 212 has the first stop surface 211 corresponding in position to one side of the roller 1 so as to come into smooth contact with the roller 1 .
[0065] In addition, the present invention puts no limit on the technical feature that the roller 1 is directly coupled to the load 3 through the bush 2 . Referring to FIG. 14 , in a variant embodiment, a frame 6 is provided. The engaging portion 22 of the bush 2 is coupled to the frame 6 in advance, and then the engaging portion 22 of the bush 2 is coupled to the load 3 through the frame 6 ; hence, one or more roller structures of the present invention function as module with standard specifications so as to couple the rollers and the load 3 quickly. In a preferred embodiment, the frame 6 is slender, plate-shaped or of any other geometric shapes as needed, and is coupled to the load 3 by the load 3 by a riveting mechanism, an expansion mechanism, a welding mechanism, an engaging mechanism, a fastening mechanism, a magnetic attraction mechanism, or any equivalent mechanism.
[0066] As regards the sequence of the assembly of the roller structures of the present invention, it is feasible that the roller 1 and the axial portion 12 are coupled to the bush 2 and the second stop portion 4 in advance to form a module, and then the engaging portion 22 of the bush 2 is coupled to the load 3 or the frame 6 by one of the aforesaid mechanisms. In a variant embodiment, it is practicable for the roller 1 and the axial portion 12 to be coupled to the second stop portion 4 in advance to form module, and then for the bush 2 to be coupled to the load 3 to form a module, and eventually for the axial portion 12 to be coupled to the bush 2 , the two modules are coupled together. However, the aforesaid sequence is subject to changes as needed. In addition, the present invention is characterized in that the engaging portion 22 of the bush 2 is coupled to the load 3 or frame 6 by a riveting mechanism, an expansion mechanism, a welding mechanism, an engaging mechanism, a fastening mechanism or a magnetic attraction mechanism. The engaging portion 22 of the bush 2 has a feeding space 221 . After the feeding space 221 has been aligned with an installation hole 31 of the load 3 , the material which the load 3 is to be made of is injected into the feeding space 221 of the engaging portion 22 as soon as a die 10 presses against the roller 1 or the second stop portion 4 (shown in FIG. 11 ) or another die 20 presses against the load 3 (shown in FIG. 11 ) or the engaging portion 22 (shown in FIG. 13 ), thereby allowing the engaging portion 22 to be coupled to the load 3 to therefore effectuate quick assembly and enhance the efficiency of assembly.
[0067] The present invention further provides a manufacturing method for use with the aforesaid roller structure. The manufacturing method is characterized in that: a pressed portion 121 (shown in FIG. 10 and FIG. 12 ) is disposed at one end of the axial portion 12 by being formed integrally therewith, and the pressed portion 121 is cylindrical or of any equivalent shape. Referring to FIG. 11 and FIG. 13 , and the second stop portion 4 positioned proximate to the roller 1 is formed by performing a pressing process on the pressed portion 121 via a die 10 . The advantages of the manufacturing method are as follows: the second stop portion 4 is formed quickly; and an assembly process of the roller 1 is quickly carried out especially when the roller structure of the present invention functions as a standardized module.
[0068] As regards the manufacturing method for use with the aforesaid roller structure according to the present invention, the engaging portion 22 of the bush 2 is coupled to the load 3 or the frame 6 by a riveting mechanism, an expansion mechanism, a welding mechanism, an engaging mechanism, a fastening mechanism or a magnetic attraction mechanism. The engaging portion 22 of the bush 2 has a feeding space 221 ; hence, after the feeding space 221 has been aligned with the installation hole 31 of the load 3 , the material which the load 3 is to be made of is injected into the feeding space 221 of the engaging portion 22 as soon as a die 10 presses against the roller 1 or the second stop portion 4 (shown in FIG. 11 ) or another die 20 presses against the load 3 (shown in FIG. 11 ) or the engaging portion 22 (shown in FIG. 13 ), thereby allowing the engaging portion 22 to be coupled to the load 3 to therefore effectuate quick assembly and enhance the efficiency of assembly.
[0069] Referring to FIG. 3 and FIG. 15 , a diameter a of the engaging portion 22 of the bush 2 is larger (shown in FIG. 15 ) or smaller (shown in FIG. 3 ) than a diameter b of the roller 1 . In addition, the feeding space 221 of the engaging portion 22 of the bush 2 faces the roller 1 (shown in FIG. 15 ) or faces away from the roller 1 (shown in FIG. 3 ).
[0070] Referring to FIG. 14 and FIG. 16 to FIG. 19 , the engaging portion 22 of the bush 2 is coupled to the load 3 (or the frame 6 ) via using a die 10 to press the second stop portion 4 (shown in FIG. 16 ), the roller 1 (shown in FIG. 17 ), the engaging portion 22 of the bush 2 (shown in FIG. 19 ) or the first stop portion 21 of the bush 2 (shown in FIG. 18 ).
[0071] The present invention is disclosed above by preferred embodiments. However, persons skilled in the art should understand that the preferred embodiments are illustrative of the present invention only, but should not be interpreted as restrictive of the scope of the present invention. Hence, all equivalent modifications and replacements made to the aforesaid embodiments should fall within the scope of the present invention. Accordingly, the legal protection for the present invention should be defined by the appended claims. | A roller structure and a manufacturing method thereof are introduced. The roller structure includes a roller rotatable about an axial portion; a bush with an end disposed to an end of the axial portion and has a first stop portion positioned proximate to one side of the roller and another end having an engaging portion coupled to a load; and a second stop portion disposed to the other end of the axial portion and positioned proximate to the other side of the roller such that the roller rotates between the first stop portion and the second stop portion. Hence, the roller structure and the manufacturing method thereof provide a modularized roller structure for carrying a load, effectuate modularized assembly and production, enhance assembly efficiency, attain structural streamlining, and cut costs. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the technology of controlling the light intensity of illumination devices, and more particularly to a light emitting diode (LED) dimming and driving method of controlling brightness by a current signal and a circuit using the method, and a non pulse width modulation (PWM) signal is used for controlling the brightness to enhance the efficiency of the circuit and the dimming accuracy.
2. Description of the Related Art
In general, a dimming circuits of most LED lamps changes a voltage phase of a power supply by using a switch device such as a silicon controller rectifier (SCR) or a tri-electrode AC switch (TRIAC Switch) and changes the total driving voltage outputted from a driving circuit by switching a phase conduction angle, so as to adjust the driving current inputted into an LED source and achieve a dimming effect. Although such dimming device has the advantages of easy control and simple installation, the voltage waveform of the power supply may be situated at a distortion status to give rise to the problems of a low PF and an increased harmonic voltage. According to the current/voltage (I/V) characteristic curve of LED, LED is a nonlinear element. In other words, the ratio of voltage to current is not a direct proportional ratio, so that the aforementioned dimming method has an inaccurate dimming effect and consumes much power since the change of the driving voltage and the change of driving current are unequal, and thus resulting in an inaccurate dimming effect and consuming much power. Therefore, a conventional driving circuit of an LED generally connects a transistor and a sensing resistor in series and uses the sensing resistor to detect an LED current and then regulates a duty ratio of a pulse width modulation (PWM). By controlling the conduction or disconnection of the transistor by the PWM signal, the outputted driving voltage can be regulated to keep the LED current constant.
Although the aforementioned driving circuit is applicable for the mains power of 80-260V and provides a convenient use, the driving circuit is affected by the properties of the TRIAC component. If the voltage frequency of the PWM signal is too low and the current passing through the TRIAC is lower than the required operating current, the TRIAC will be switched repeatedly, so that the driving current will be not be continuous, and a blinking problem of the LED occurs. On the other hand, if the voltage frequency of the PWM signal is too high, a change of the voltage of the signal will be too quick to cause noises and interferences, result in an abnormal operation of the LED, and reduce practicality. To overcome the aforementioned problem, a conventional PWM driving circuit 1 having a dimmer 10 as shown in FIG. 1 includes a compensation circuit 12 additionally installed next to a control circuit 11 and comprised of a reference voltage generator 120 , a voltage sampler 121 , a comparator 122 and a control switch 123 , wherein the comparator 122 is provided for comparing a reference voltage generated by the reference voltage generator 120 with a sample voltage formed by the voltage sampler 121 , and if the sample voltage is smaller than the reference voltage, a control voltage will be outputted to the control switch 123 , so that the compensation circuit 12 and the control circuit 11 form a loop, and the control switch 123 provides a hold current to the control circuit 11 to assure the operating stability of the dimmer 10 and prevent the blinking issue of the LED. Although such additionally installed compensation circuit 12 can assure a stable operating quality of the dimmer 10 , there is a power loss that affects the overall system efficiency severely, and the method of using the TRIAC to output the voltage signal for the dimming purpose may have a loss of signals during the signal transmission, and thus the dimming efficiency may be affected adversely.
Therefore, it is a main subject of the present invention to improve the dimming mechanism, components and structure of the LED driving circuit to assure the normal operating efficiency of the overall circuit, and the operating stability and the dimming accuracy of the LED lamps.
SUMMARY OF THE INVENTION
In view of the aforementioned problem of the prior art, it is a primary objective of the present invention to provide an LED dimming and driving method and its circuit that use a current signal to control the current of an LED for dimming, so as to avoid a loss of voltage signal that may affect the dimming accuracy.
To achieve the aforementioned objective, the present invention provides an LED dimming and driving method comprising the steps of: using a dimming module installed in an LED dimming and driving circuit to adjust the brightness of a plurality of LED strings; and using the dimming module to adjust a driving current of the LED strings by a current signal to achieve the effect of enhancing a linear dimming accuracy, characterized in that after the dimming module receives a dimming signal, an internal current source is driven to output current with a magnitude corresponsive to the dimming signal, and a terminal resistor is used to convert the current into a voltage level, and the driving currents are adjusted according to the voltage level to affect the brightness of the LED strings.
Wherein, the dimming module intercepts the driving current by a current mirror to obtain a brightness value, and after the voltage level is compared with the brightness value, the current mirror adjusts the magnitude of the driving currents to achieve a linear dimming effect. In addition, the LED dimming and driving method further comprises the steps of detecting a driving current of the LED strings to obtain a minimum driving voltage and comparing and adjusting a conduction cycle of a cycle switch installed in the LED dimming and driving circuit to adjust the total output of the output voltage to assure that the total output voltage is greater than a forward bias voltage of the LED strings.
To achieve the aforementioned objective, the present invention further provides an LED dimming and driving circuit comprising a conversion module, an energy distribution module and a dimming module, and the energy distribution module is electrically coupled to the conversion module and a plurality of LED strings, and the LED strings are electrically coupled to the dimming module, and a transformer is installed in the conversion module for supplying an output voltage generated by sensing an input voltage by the energy distribution module to the LED strings, so that each LED string has a driving current, characterized in that the dimming module comprises a receiver, a current source and a controller, and the controller includes a terminal resistor electrically coupled to the LED strings and the current source, and the current source is electrically coupled to the receiver, and after the receiver has received a dimming signal, the current source is driven to output a current with a magnitude corresponsive to the dimming signal and provided for the controller to convert the current into a voltage level by the terminal resistor and regulate the magnitude of the driving currents.
In addition, the energy distribution module comprises a minimum voltage detector, an error amplifier, a comparator and a cycle switch, and the minimum voltage detector is coupled to the LED strings and a positive input terminal of the error amplifier, and a negative input terminal of the error amplifier receives a reference value, and the output terminal is coupled to a negative input terminal of the comparator, and an output terminal of the comparator is coupled to the cycle switch, and both ends of the cycle switch are respectively and electrically coupled to the transformer and the LED strings, and the minimum voltage detector is provided for detecting a driving current of the LED strings to obtain a minimum driving voltage which is provided for the error amplifier to determine the minimum driving voltage and the reference value to obtain an error value, and the total output of the output voltage is regulated and compared with the error value after the comparator regulates a conduction cycle of the cycle switch by a triangular wave, so as to assure the total output voltage is greater than a forward bias voltage of the LED strings.
In summation, the present invention achieves a dimming effect without using the method of controlling the phase angle of the input voltage by the TRIAC to regulate the working cycle of the output voltage. In other words, the method of adjusting the light intensity of the LED by using the PWM signal is not used, so that the present invention does not have the issues of obvious dimming delay or poor dimming accuracy
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic circuit diagram of a conventional PWM driving circuit;
FIG. 2 is a schematic block diagram of a preferred embodiment of the present invention;
FIG. 3 is a flow chart of a preferred embodiment of the present invention; and
FIG. 4 is a schematic circuit diagram of a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The aforementioned and other objectives, technical characteristics and advantages of the present invention will become apparent with the detailed description of preferred embodiments and the illustration of related drawings as follows.
With reference to FIGS. 2 to 4 for a schematic block diagram, a flow chart, and a schematic circuit diagram of an LED dimming and driving circuit 2 of a preferred embodiment of the present invention respectively, the LED dimming and driving circuit 2 is applied in a liquid crystal display device, a television or an LED lamp and electrically coupled to a plurality of LED strings 3 , and the LED dimming and driving circuit 2 comprises a rectification module 20 , a conversion module 21 , an energy distribution module 22 and a dimming module 23 , wherein the energy distribution module 22 is electrically coupled to the conversion module 21 and the LED strings 3 , and the LED strings 3 are electrically coupled to the dimming module 23 . The rectification module 20 which is a bridge rectifier circuit coupled to an external power supply (not shown in the figure) and the conversion module 21 , and the conversion module 21 comes with a flyback, forward, full bridge, half bridge or push-pull switching effect, or adopts a power conversion circuit with a coupling coil such as a LLC serial resonant coil as the main architecture and having a transformer 210 and a conversion controller 211 .
For example, the conversion module 21 of a primary-side control flyback power conversion circuit architecture includes a transformer 210 with a primary-side coil (N 1 ), a secondary-side coil (N 2 ) and an auxiliary coil, and the conversion controller 211 includes a current transistor 2110 , a current resistor 2111 and a conversion control chip 2112 , and the primary-side coil is connected to the current transistor 2110 and the current resistor 2111 in series and then coupled to the conversion control chip 2112 . The energy distribution module 22 includes a minimum voltage detector 220 , an error amplifier 221 , a comparator 222 , a triangular wave generator 223 and a cycle switch 224 , wherein the minimum voltage detector 220 is coupled to the LED strings 3 and a positive input terminal of the error amplifier 221 , and a negative input terminal of the error amplifier 221 is provided for receiving a reference value (Vref) and an output terminal of the error amplifier 221 is coupled to a negative input terminal of the comparator 222 . A positive input terminal of the comparator 222 is coupled to the triangular wave generator 223 and provided for receiving a triangular wave, and an output terminal of the comparator 222 is coupled to the cycle switch 224 , and both ends of the cycle switch 224 are respectively and electrically coupled to the secondary-side coil and the LED strings 3 . The dimming module 23 includes a receiver 230 , a current source 231 and a controller 232 , and the controller 232 is comprised of an operational amplifier 2320 , a current mirror 2321 and a terminal resistor 2322 . An end of the current mirror 2321 is coupled to the LED strings 3 through a plurality of first regulators 2323 respectively, and the other end of the current mirror 2331 is coupled to an output terminal and a negative input terminal of the operational amplifier 2320 through a second regulator 2324 , and a positive input terminal of the operational amplifier 2320 is coupled to the terminal resistor 2322 and the current source 231 , and the current source 231 is electrically coupled to the receiver 230 .
The LED dimming and driving method of the present invention comprises the following steps:
S 1 : The bridge rectifier of the LED dimming rectifies and converts an AC voltage of the external power supply into an input voltage.
S 2 : The input voltage charged or discharged by an energy storage capacitor 212 is provided for the energy storage of the primary-side coil to form a primary-side current, and the secondary-side coil senses a change of the primary-side current to form an output voltage by the principle of electromagnetic induction. It is noteworthy that the conversion control chip 2112 performs detections through the current resistor 2111 and regulates the value of the primary-side current by the current transistor 2110 to control the output voltage at a stable voltage value.
S 3 : The energy distribution module 22 outputs the output voltage to the LED strings 3 , such that a driving current passes through each LED string 3 .
S 4 : The minimum voltage detector 220 detects a driving current of the LED strings 3 to obtain a minimum driving voltage, and provides the driving current to the error amplifier 221 to determine the minimum driving voltage and the reference value to obtain an error value, and after the comparator 222 compares the error value by using the triangular wave, a conduction cycle of the cycle switch 224 is regulated to adjust the total output of the output voltage, so as to assure the total output voltage is greater than a of the LED strings 3 while maintaining the driving currents at a constant value.
S 5 : The receiver 230 determines whether or not to receive a dimming signal. If yes, the receiver 230 may receive a dimming signal via wireless or cable transmission.
S 50 : The receiver 230 drives the current source 231 to output a current with a magnitude corresponsive to the dimming signal, and the current is converted into a voltage level by of the controller 232 by the terminal resistor 2322 .
S 51 : The current mirror 2321 receives the driving current from the second regulator 2324 to obtain a brightness value.
S 6 : The operational amplifier 2320 compares the voltage level with the brightness value to regulate the operating status of the second regulator 2324 , so as to regulate the conduction and cutoff cycle of the first regulators 2323 to affect the magnitude of the driving currents and achieve a linear dimming effect. | In an LED dimming and driving method and its circuit, a receiver, a current source and a controller are installed in a dimming module, and after the receiver has received a dimming signal, the current source is driven to output a current with a magnitude corresponsive to the dimming signal, and then after the controller has converted the current into a voltage level by a terminal resistor, the magnitude of the driving current of the LED is adjusted according to the voltage level to improve a linear dimming accuracy. | 8 |
TECHNICAL FIELD
This invention relates to a method of making polymerizable tertiary hindered amines beginning with certain secondary hindered amines as reactants. The invention involves reaction of the secondary hindered amine with an appropriate terminally unsaturated hydrocarbon electrophile in the presence of a solvent selected from N,N-dialkylamides and N,N,N'N'-tetraalkylureas. The alkyl groups in the solvent may form a ring as in N-methylpyrrolidinone.
BACKGROUND OF THE INVENTION
Hindered amines are widely used as stabilizers for polyolefins. The largest category of hindered amine stabilizers is made from triacetoneamine, a hindered secondary amine. In some stabilizers sold commercially, the hindered amine remains secondary, unchanged from the parent triacetoneamine. In other commercial stabilizers the hindered amine is tertiary, and alkylation of the hindered secondary amine is required during their production.
The alkylation of hindered secondary amines has a general drawback: many hydrocarbon electrophiles eliminate to alkenes in competition with amine alkylation. Elimination converts the electrophile into a waste alkene, and it makes the secondary amine into an ammonium salt. The ammonium salt does not alkylate without being turned back into a free amine.
Due to elimination, numerous hindered tertiary amines which might exist are presumed to be costly and probably impractical, based on prior art. In commercial stabilizers, only electrophiles which cannot easily eliminate are used to alkylate hindered secondary amines. Thus, the available hindered tertiary amines contain either 2-hydroxyethyl groups from alkylation by ethylene oxide, or they contain methyl groups from alkylation by methyl electrophiles. Methyl groups may also be introduced by reductive alkylation with formaldehyde, a reaction which is not readily extended to alkyl groups other than methyl.
For example, alkylation by ethylene oxide is described in U.S. Pat. No. 4,731,448 issued Mar. 15, 1988 to Ciba-Geigy. The alkylation of 2,2,6,6-tetramethylpiperidine (TMP) by ethylene oxide is described in J. Org. Chem. 6 381 (1963).
An example of the methylation with formaldehyde may be seen in column 5 of U.S. Pat. No. 3,974,127 of Aug. 10, 1976 to Du Pont.
The difficult alkylation of hindered secondary amines can lead to side reactions other than elimination. In Chem. Abstr. 108:221569t Huaxue Shiji 9, 212 (1987) authors D. Shen, B. Su, Z. Yliang L. Shu and X. Su describe competing oxygen alkylation during the attempted N-alkylation of 2,2,6,6-tetramethylpiperidin-4-ol (TMPOH).
Elimination can be prominent during efforts to alkylate hindered secondary amines. Note that TMPOH has been used as a reagent in a method for alkyl bromide dehydrobromination. In Z. Naturforsch, 33b, 792-796 (1978), Konieczny and Sosnovsky heat 1-bromoheptane and 1-bromooctane in dimethyl sulfoxide with TMPOH. Heptene and octene are isolated in yields of 82% and 93%, respectively. Also obtained in each case is a high yield of the hydrobromide salt of TMPOH.
A method of alkylating TMPOH is disclosed in U.S. Pat. No. 4,014,887 of Mar. 29, 1977 to Ciba-Geigy. In example 1, 12.5 parts 1-bromododecane and 15.7 parts TMPOH are heated to reflux in 50 parts ethyl alcohol for 72 hours. No yield is given for the claimed product 1-(1-dodecyl)-2,2,6,6,-tetramethylpiperidin-4-ol. The only analytical data provided are combustion analysis and melting point, and these do not prove the absence of the ether 4-(1-dodecyloxy)-2,2,6,6-tetramethylpiperidine. In addition to uncertain product purity, this method may suffer from a low yield. The three day reaction time is highly undesirable.
Three days at reflux are also used in U.S. Pat. No. 3,956,310 (May 11, 1976 to Ciba-Geigy). In example 25, a large molar excess of bromohexane is heated in acetonitrile with TMPOH. The isolated yield is only 27% of the theoretical for 1-(1-hexyl)-2,2,6,6-tetramethylpiperidin-4-ol, based on TMPOH.
U.S. Pat. No. 4,014,887 was filed in the United Kingdom as no. 48601 in 1972. According to Chem. Abstr. 81:153691, UK 48601/72 is also DE 2,352,658 on Apr. 25, 1974. In Makromol. Chem. 818, 595-633 (1980), F. E. Karrer cites DE 2,352,658 as reference 58. Karrer reports the formation of 1-(1-butyl)-2,2,6,6-tetramethylpiperidin-4-ol in 69% yield using the method of reference 58. Since Karrer characterizes the product only by melting point, the absence of the ether 4-(1-butoxy)-2,2,6,6-tetramethylpiperidine is not proven.
Authors Kurumada, Ohsawa, Fujita and Toda in J. of Polymer Science: Polymer Chem. Edition, 22, 277 (1984) alkylate4-benzoyloxy-2,2,6,6-tetramethylpiperidine (6.6 parts) with n-butyl iodide (25 parts) in N,N-dimethylformamide (47 parts) in the presence of potassium carbonate (6 parts). The reaction temperature is 130°-140° C. for 29 hours. The large molar excess of butyl iodide is an inefficient use of this electrophile, and might lead to acidification of the reaction mixture through elimination to butene and hydrogen iodide. The hydrogen iodide will form ammonium salt of the starting material which will not alkylate, reducing conversion and yield. The combination of hydrogen iodide and potassium carbonate at elevated temperature might hydrolyze the benzoate ester for a loss of yield and purity. The potassium carbonate at elevated temperature might decompose the butyl iodide. These drawbacks lead to a low yield of 44%.
In U.S. Pat. No. 3,940,363 (Feb. 24, 1976 to Sankyo) the bisalkylation of 4-benzoyloxy-2,2,6,6-tetramethylpiperidine is described. The yield of diamine product is unspecified using either 1,2-dibromoethane at reflux for four hours, or using 1,6-dibromohexane at reflux. The use of 5 parts 1,2-dibromoethane to 3 parts 4-benzoyloxy-2,2,6,6-tetramethylpiperidine is a large molar excess of alkyl bromide, so the reaction mixture might become acidic by elimination of hydrogen bromide. An acidic reaction mixture could decompose a terminal alkene electrophile.
One object of this invention is the preparation of N-alkylated derivatives of TMPOH free of O-alkylated (ether) impurities and in an overall high state of purity. Furthermore, this invention achieves shorter reaction time. The yield with respect to electrophiles is improved for those electrophiles prone to elimination.
An alkylation of 2,2,6,6,-tetramethylpiperidine (TMP) is described in U.S. Pat. No. 3,975,357 (Aug. 17, 1976 to Sankyo in referential example 1. Over 120 hours at 125°-130° C., 56.4 parts TMP and 38.6 parts 1-bromooctane give 1-(1-octyl)-2,2,6,6-tetramethylpiperidine in unspecified yield. The five day reaction time is highly undesirable. The same method is described using 1-bromododecane, also with no yield.
The long reaction times used in the prior art during hindered amine alkylation do not minimize the risk of terminal to internal alkene isomerization. Terminal alkenes are less stable than their internal isomers. In addition, the long reaction times cause inefficient preparation.
A published synthesis of 1-(1-butyl)-2,2,6,6-tetramethylpiperidine requires 37 hours at 50° C. In J. Am. Chem. Soc. 111 6070 (1989) Bonessen, Puckett, Honeychuck and Hersh obtain 3.5 parts product (64% yield based on TMP) from 3.9 parts TMP and 26.9 parts 1-iodobutane. Also present during the reaction are 5.5 parts potassium carbonate and 28.3 parts N,N-dimethylformamide. The large excess of electrophile used would be uneconomical on a practical scale, particularly so with any expensive electrophile bearing a terminal alkene. The presence of the added carbonate base allows higher than 50% TMP conversion, but it precludes the higher reaction temperatures used in the present invention; the carbonate would decompose the electrophile as temperatures are increased. Because of the excess of iodobutane the reaction mixture could become acidic; an acidic reaction mixture would decompose a terminal alkene.
A synthesis of 1-ethyl-2,2,6,6-tetraethylpiperidine requires ten hours at 50° C. In J. Polymer Sci: Polymer Chem. Ed. 23 1477 (1985), Kurumada et al obtain 6.8 parts product from 14.1 parts TMP (40% yield based on TMP) using 30 parts ethyl iodide and 8 parts potassium carbonate in 14 parts N,N-dimethylformamide. This method uses excess iodoethane, requires added carbonate, and gives a low yield.
Authors Dagonneau, Kagan, Mikhailov, Rozantsev and Sholle in Synthesis 1984 895 review hindered amines and cite Hall, J. Am. Chem Soc. 79 5444 (1957) for alkylations of TMP with methyl toluenesulfonate and ethyl toluenesulfonate. The 63% methylation yield in 30 minutes at 100° C. drops to a 9% yield of 1-ethyl-2,2,6,6-tetramethylpiperidine using prolonged heating.
The difficulty in making tertiary amines from hindered secondary amines is shown by a synthesis of 1-(1-propyl)-2,2,6,6,-tetramethylpiperidine as described by Anderson, Casarini, Corrie and Lunazzi in J. Chem. Soc., Perkin Trans. 2 1993, 1299. TMP (7.5 parts) is combined with excess propionyl chloride and triethylamine to give 5.3 parts crude amide. Reduction by 1.5 parts lithium aluminum hydride gives only 1.3 parts product, for a yield of 13%. In addition to the multiple steps and the low yield, the metal hydride reagent is impractical.
SUMMARY OF THE INVENTION
In the present invention, certain hindered secondary heterocyclic amines are converted to hindered tertiary amines by reaction with primary carbon electrophiles at temperatures above 100° C. in the presence of amide or urea solvents. The hindered tertiary amines are useful as heat and light stabilizers in synthetic resins, or as stabilizer precursors.
The starting materials are heterocyclic amines of the formula ##STR1## where each R is independently an alkyl group having from one to two carbon atoms, each R 1 is H or CH 3 , Z is a non-nucleophilic group; preferably Z is H, an alkyl, aryl, or aralkyl group having from 1-8 carbon atoms, --OOCR 2 or ##STR2## R 2 is C 1-8 alkyl, aryl or alkaryl group, and n is an integer from 2 to 10. Examples of the secondary amines include 2,2,6,6-tetramethylpiperidine (TMP), the acetic acid ester of 2,2,6,6-tetramethylpiperidin-4-ol (TMPOH), and bis (2,2,6,6-tetramethyl-4-piperidinyl) sebacate.
The electrophiles are preferably halides (bromides or iodides) or sulfonate esters:
CH 2 ═CH(CH 2 ) q X or CH 2 ═CH(CH 2 ) q OSO 2 R 3 , where X is Br or I, q is 3-20, and R 3 is an alkyl, aryl, or aralkyl group having from one to ten carbon atoms.
Electrophiles where X is Br or I may be formed in the reaction from the corresponding Cl or F substances by halide exchange with bromide or iodide salts. They are also formed by exchange of bromide or iodide salts with sulfonate electrophiles. While Example 8 below demonstrates the difficulty of using a chloride electrophile by itself, Examples 7, 9, and 11-15 show that an efficient bromide or iodide electrophile can be made in situ.
Cost, availability, solubility and vapor pressure are all factors which can affect the choice of leaving group present in the electrophile. The electrophilic compound preferably has a molecular weight less than about 600 and more than about 100. If added iodide anion is used (from an added iodide salt), it may be present in an amount between 0.005 mole equivalent and 1.2 mole equivalent (0.5 mole % to 120 mole %) of the electrophile.
The reaction is conducted with an excess of amine with respect to electrophile, i.e. at a molar ratio of amine to electrophile of from about 2 to about 10, and at a temperature between 100° C. and 200° C. At these ratios, the electrophile can be completely consumed. The solvent is as described below.
The two categories of solvent are N,N-dialkylamides and N,N,N',N'-tetraalkylureas:
R 1 R 2 NCOR 7 and R 3 R 4 NCONR 5 R 6
where R 1-7 are independently chosen from alkyl, aryl, and alkaryl groups having from 1 to 12 carbon atoms; in addition, R 7 may be hydrogen, and any two R's may form a ring. An example of a ring compound is N-methylpyrrolidinone (NMP). Due to low cost, ready availability, low human toxicity and convenient physical properties, NMP is preferred. In NMP, R 1 and R 7 form a ring. It is also possible for R 1 and R 2 to form a ring. In the urea structure, rings can span R 4 and R 5 , and they can connect R 5 and R 6 .
Another way of expressing the suitable solvents is with the generic formula (R 4 ) 2 NCOR 8 where R 8 is H, C 1-12 alkyl, aryl or alkaryl, or N(R 4 ) 2 , each R 4 is independently selected from C 1-12 alkyl, aryl and alkaryl groups and any two R's may form a ring.
The choice of solvent may be based on high yield of the desired product, cost, ease of separation from products, ease of recycle, availability, human health effects, and other biological effects.
For convenience the reaction may be run at atmospheric pressure. Elevated or reduced pressures may be used, if desired. Low pressures are limited only by the vapor pressure of the components; since the reaction occurs in liquid, volatile components must have some concentration in the liquid phase.
Any hindered secondary amine which is recovered unreacted may be recycled.
Water is not beneficial in the system and is excluded by the use of dry solvents and reactants, and by blanketing the reaction mixture with an inert atmosphere. In the examples shown, solvent is separated from product and excess reactants by extraction of the NMP into water. This creates a disadvantage for the reuse of the solvent, since it must be dried beforehand. An alternative product isolation which maintains dry solvent is feasible. The ammonium salts present in the reaction mixture can be freed by a base which does not lead to coproduct water. Alkali metal alkoxides such as sodium methoxide can be used. Coproduct alcohol still needs to be removed, however.
DETAILED DESCRIPTION OF THE INVENTION
My invention is a method of making a hindered tertiary heterocyclic amine of the formula ##STR3## comprising reacting (a) a hindered heterocyclic amine of the formula ##STR4## where each R is independently an alkyl group having from one to two carbon atoms, R 1 is H or CH 3 , Z is a non-nucleophilic group,preferably H, an alkyl, aryl, or alkaryl group having from 1-8 carbon atoms, --OOCR 2 or ##STR5## R 2 is C 1-8 alkyl, aryl or aralkyl, and n is 2 to 10, with (b) an electrophilic compound selected from bromides and iodides of the formula CH 2 ═CH(CH 2 ) q X where X is Br or I and q is 3-20, or CH 2 ═CH(CH 2 ) q OSO 2 R 3 where q is as above and R 3 is an alkyl, aryl, or aralkyl group having from one to ten carbon atoms, in the presence of a solvent of the formula (R 4 ) 2 NCOR 8 where R 8 is H, C 1-12 alkyl, aryl or alkaryl or N(R 4 ) 2 , each R 4 is independently selected from C 1-12 alkyl, aryl and alkaryl groups and any two R's may be connected in a ring, while maintaining the molar ratio of said tertiary ring amine to said electrophilic compound greater than 2, and recovering said heterocyclic hindered tertiary amine. It is understood that, in the above formulas the unspecified valences are occupied by hydrogen.
Suitable solvents include 1-ethyl-2-pyrrolidinone, 1-cyclohexyl-2-pyrrolidinone, 1-benzyl-2-pyrrolidinone, 1-butyl-2-pyrrolidinone, 1-octyl-2-pyrrolidinone, 1-(1,1,-dimethylethyl)-2-pyrrolidinone,1-hexyl-2-pyrrolidinone, 1-dodecyl-pyrrolidinone, 1-methyl-2-piperidinone, N-methylcaprolactam, N-formylmorpholine, N-formylpiperidine, 4-acetylmorpholine, N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, 1,3-dimethyl-2-imidazolidinone (DMEU; N,N'-dimethylethyleneurea), 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU; N,N'-dimethylpropyleneurea), 1-(2-ethylhexyl)-2-pyrrolidinone, tetramethylurea, tetraethylurea, N-methylformanilide, and tetrabutylurea.
A preferred form of the solvent has the formula ##STR6## where R 5 is selected from alkyl, aryl, and aralkyl groups having from one to twelve carbon atoms. This includes the most preferred solvent, N-methylpyrrolidinone.
The invention is illustrated by the following examples.
EXAMPLE 1
Preparation of 1-(10-undecenyl)-2,2,6,6-tetramethylpiperidine.
Solvent N-methylpyrrolidinone (2459 g, H 2 O<0.050) and TMP (1033 g, 98% by gas chromatography) were stirred and heated under inert atmosphere at atmospheric pressure. Granular potassium iodide (527 g) was added gradually over about 45 minutes. At a slurry temperature of 112° C., room temperature 11-bromo-1-undecene (647 g, 99% by gc) was added over five minutes. The slurry temperature at the beginning of the 11-bromo-1-undecene addition was 112° C. and 106° C. at the end. From 106° C., the temperature was raised to 120° C. within 15 minutes, maintained at 120°-135° C. for three hours and then 120°-100° C. for four hours. The slurry was cooled to 30° C. and partitioned between aqueous sodium hydroxide and hexane to give two homogeneous liquid layers. The upper organic layer was separated and distilled below atmospheric pressure at a maximum of 90° C. to remove a volatile mixture including hexane and TMP. Redistillation of the volatile mixture at atmospheric pressure gave recovered TMP suitable for reuse in alkylation. The portion remaining after hexane and TMP removal was short-path distilled at approximately 3 mm Hg. The portion boiling above 155° C. and below 164° C. was 704 g of clear liquid (98.9% by gc). It collected over 2.5 hours at a maximum pot temperature of 170° C. The desired structure was confirmed by NMR.
EXAMPLE 2
Attempted preparation of 4-hydroxy-1-(10-undecenyl-2,2,6,6-tetramethylpiperidine using TMPOH.
A solution of N-methylpyrrolidinone (111 g) and TMPOH (55.7 g) was heated and stirred under inert atmosphere as granular potassium iodide (24.4 g) was added. When the slurry temperature was 90° C., 11-bromo-1-undecene (26.7 g) was added and the temperature was raised to 110° C. over twenty minutes, and then maintained at 110°-130° C. After one hour at 110°-130° C., an aliquot of the reaction mixture was cooled to room temperature and diluted with hexane. The hexane mixture was extracted once with excess aqueous sodium hydroxide and twice with water. Analysis of the hexane solution by gc showed the free hydroxyl result:
______________________________________ area % retention time free area %component minutes hydroxyl silyl.______________________________________undecadiene 4.39 5.3 3.41-iodo-10-undecene 18.17 7.1 5.0O-undecylated TMPOH 24.36 3.3 2.5N-undecylated TMPOH 26.21 77.7 --N-undecylated TMPOSi (CH.sub.3).sub.3 26.22 -- 81.6N,O-diundecylated TMPOH 34.03 1.5 1.0______________________________________
For the silylated analysis, the hexane solution was silylated in the presence of acetone and excess N,O-bis(trimethylsilyl)acetamide. As can be seen in the results above, the undesired O-undecenylated byproduct was formed.
EXAMPLE 3
Preparation of 4-hydroxy-1- (10-undecenyl)-2,2,6,6-tetramethylpiperidine using bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate.
Part 1. Alkylation.
Solvent N-methylpyrrolidinone (629 g, H 2 O<0.05%), bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate (500.5 g) and 11-bromo-1-undecene (140.1 g, 98.3% by gc) were heated and stirred under inert atmosphere. Beginning at 100° C., granular potassium iodide (95.5 g) was gradually added over one hour, with a slurry temperature of 138° C. at the end of the hour. The slurry was stirred at 135°-140° C. for an additional eighteen hours, then cooled to room temperature. The slurry was diluted with heptane and methyl butyrate, and ammonium salts were freed by adding 60 g 50% aqueous sodium hydroxide and 400 mL water. After mixing, two clear liquid layers separated. The aqueous layer was extracted with heptane and the combined organic portions were extracted four times with water. The organic layer was concentrated on a rotary evaporator, then heated at about 3 mm Hg. The clear brown liquid remaining was 588.5 g.
Part 2. Hydrolysis.
The crude product from part 1 was stirred and heated to reflux for 58 hours with potassium hydroxide pellets (280 g) and water (1.5 L). The mixture was cooled in an ice bath without agitation. The aqueous layer containing dissolved potassium sebacate was drained off. The waxy organic was triturated with hexane (4×300 mL) and all the hexane portions were passed through a fritted glass filter. The solid retained in the filter was TMPOH and weighed 180 g after drying. The filtrate was concentrated on a rotary evaporator to 177.5 g dark brown oil.
Part 3. Distillation.
Short-path distillation at about 3 mm Hg gave a small forecut of TMPOH, followed by 4-hydroxy-1-(10-undecenyl)-2,2,6,6-tetramethylpiperidine (152.6 g) at 185°-188° C. head temperature and 190°-200° C. pot temperature. The distillate was collected with an air-cooled condenser. It set to a waxy solid after briefly chilling the hot distillate with dry ice. The distillate remained solid at room temperature. It was heated, melted and then swirled to homogenize. An aliquot was diluted in acetone for analysis by gc: 0.2% TMPOH by area at 5.31 minute retention time, and 99.2% product at 26.05 minute retention time. No O-alkylated byproduct was found, while the smallest impurity detected was 0.02% by area at 25.03 minute retention time. The structure was confirmed by NMR; the terminal unsaturated group was present.
Persons skilled in the art will recognize that at the end of the Alkylation step, a mixture was obtained which contained mono-N-undecenyl and di-N-undecenyl derivatives of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate as well as starting material. Hydrolysis converted this mixture to TMPOH and 4-hydroxy-1-(10-undecenyl)-2,2,6,6-tetramethylpiperidine.
No ether impurities were detected in Example 3 in contrast to Example 2, where they were present. Persons skilled in the art will observe that my method provides high yields of tertiary amines in reduced reaction times. The products can be isolated in a high state of purity without difficult and expensive chromatography or recrystallization. In some cases extraction followed by simple vacuum distillation gives pure product. Sensitive electrophiles such as terminal alkenes may react selectively without isomerization to internal alkenes. The side reaction of oxygen alkylation during attempted N-alkylation of hindered aminoalcohols may be totally averted by the use of ester protecting groups. The esters are easily removed after N-alkylation by nucleophiles. Suitable nucleophiles include water, alkali hydroxides and alkali alkoxides.
EXAMPLE 4
Preparation of 1-(4-pentenyl)-2,2,6,6-tetramethylpiperidine using a sulfonate ester.
Solvent N-methylpyrrolidinone (456 g, water<0.05%) and TMP (363.9 g, 98.1% by gc) were heated and stirred under inert atmosphere. At 120° C. solution temperature the methanesulfonate ester of 4-penten-1-ol (164.9 g, 99.8% by gc) was added and the temperature was maintained at 110°-130° C. Potassium iodide (8.4 g) was added ninety minutes after the sulfonate ester. Twenty hours after the sulfonate ester addition the mixture was cooled to 95° C. and water (200 mL) was added. Aqueous sodium hydroxide (82.6 g) was added to the room temperature mixture, and the aqueous and organic layers were separated. The aqueous layer was extracted twice with hexane and the combined organic portions were extracted three times with water. The organic portion was concentrated on a rotary evaporator then short-path distilled at about 3 mm Hg. The distillate at 80°-87° C. head temperature and 88° C. pot temperature was 1-(4-pentenyl)-2,2,6,6-tetramethylpiperidine (133.6 g), a clear colorless liquid. Analysis by gc showed 95.5% by area product.
EXAMPLE 5
Preparation of 1-(4-pentenyl)-2,2,6,6-tetramethylpiperidine using 1-iodo-4-pentene. Solvent N-methylpyrrolidinone (499 g, water<0.05%) and TMP (397.0 g, 99.4% by gc) were heated and stirred under inert atmosphere. Neat room temperature 1-iodo-4-pentene (212.8 g, 99.0 % by gc) was added in one portion to the 120° C. reaction mixture, giving a temperature of 112° C. Within ten minutes the solution temperature was 126° C., and a temperature of 120°-140° C. was maintained for fourteen hours. The mixture was cooled to 45° C. and aqueous sodium hydroxide (91 g 50% aqueous sodium hydroxide diluted with water to 400 mL total volume) was introduced. At 28° C. hexane (200 mL) was added and the layers were separated. The aqueous layer was extracted with hexane (2×400 mL) and the combined organic portions were extracted with water (4×60 mL). Concentration on a rotary evaporator at reduced pressure and 95° C. bath temperature left 269.6 g of clear orange liquid. Short-path distillation at about 15 mm Hg, 107°-114° C. head temperature and 112°-120° C. pot temperature gave 1-(4-pentenyl)-2,2,6,6-tetramethylpiperidine (183.6 g) as a clear colorless liquid. An aliquot diluted in methanol was analyzed by gc as 0.2 area % TMP and 99.2% product. The product structure was confirmed by NMR; only the terminal olefin was present.
EXAMPLE 6
Preparation of 1-(5-hexenyl)-2,2,6,6-tetramethylpiperidine using a sulfonate ester in the absence of added iodide.
A mixture of TMP (407.8 g, 99.4% by gc) and 5-hexenyl methanesulfonate (152.2 g, 96.60% by gc) was heated and stirred at atmospheric pressure under argon in N-methylpyrrolidinone (550 g, H 2 O<0.05%). After twelve hours at 145°±15° C., the mixture was cooled. At 90° it set to a solid and water (200 mL) was added to give a stirred solution. Aqueous sodium hydroxide (110 g, 50% by weight) was added and the stirred mixture was cooled to room temperature. Water (300 mL) and hexane (300 mL) were added and the layers were separated. The lower aqueous layer was extracted with hexane (3×100 mL). The combined organic layers were extracted with water (4×75 mL). The organic layer was concentrated on a rotary evaporator at 85° C. and 60 mm Hg to 213.0 g black liquid. Short-path distillation at 14 mm Hg removed a forecut up to 129° head temperature at 136° pot temperature. The product (99.8 g) distilled at 130°-135° head temperature and 137°-145° pot temperature. The main cut was a pale yellow liquid, 97.1% pure by gc area.
EXAMPLE 7
Preparation of 1-(10-undecenyl)-2,2,6,6-tetramethylpiperidine in 1,1,3,3-tetramethylurea.
A mixture of 1,1,3,3-tetramethylurea (816.7 g, H 2 O<0.01%), TMP (381.7 g, >99% by gc) and potassium iodide (149.0 g, 0.898 mole) was stirred under argon at 125° C. Neat 11-chloro-1-undecene (170.9 g) was added and the mixture was stirred at 120°-130° C. for twenty-four hours. The mixture was brought to 20° C. with stirring and then poured into a separatory funnel using hexane (300 mL) and water (600 mL) containing aqueous sodium hydroxide (98 g of 50% by weight). The mixture was shaken and the layers were separated. The lower aqueous layer (1.5 L) was extracted with hexane (3×500 mL). The organic portions were combined and extracted with water (2×50 mL). The organic portion was concentrated on a rotary evaporator at 95° C. bath temperature and reduced pressure to a clear brown liquid (350.8 g). Short-path distillation at about 3 mm Hg removed a forecut up to 134° C. head temperature at 156° C. pot temperature. The main cut (229.9 g) was a clear yellow liquid. Assay by gc was 98%. The pot residue (4.2 g) was a brown tar.
EXAMPLE 8
Attempted Preparation of 1-(10-undecenyl-2,2,6,6-tetramethylpiperidine using 11-chloro-1-undecene.
A mixture of N,N-dimethylpropionamide (198 g), TMP (100.3 g) and 11-chloro-1-undecene (43.6 g) was stirred under argon and heated to reflux (162°-169° C). After one day at reflux an aliquot was partitioned between hexanes and aqueous sodium hydroxide and analyzed by gc: the 11-chloro-1-undecene was largely unchanged. After seven days reflux, similar analysis showed consumption of about half the 11-chloro-1-undecene. After eight days reflux the mixture was cooled to room temperature and partitioned between 50% aqueous sodium hydroxide (24 g) hexanes (250 mL) and sufficient water to dissolve all the salts. The organic layer was separated and the lower layers of water and solvent were extracted with hexanes (4×100 mL). The organic portions were combined and extracted with water (1×30 mL). The organic layer was concentrated on a rotary evaporator at about 60 mm Hg and 95° C. bath temperature to a brown oil (64.5 g). Short-path distillation at about 3 mm Hg gave a forecut (7.6 g) with maximum boiling point 107° C. Continued distillation at 150°-160° C. gave a main cut (42.1 g) which was 83.6% pure by gc.
This example demonstrates slow reaction when the halogen of the electrophile is chlorine rather than bromine or iodine. This leads to incomplete electrophile conversion and low yield, even with prolonged heating.
EXAMPLE 9
Preparation of 1-(10-undecenyl)-2,2,6,6-tetramethylpiperidine using 11-iodo-1-undecene.
A mixture of TMP (391 g), N,N-dimethylacetamide (802.0 g, H 2 O<0.01%), 11-chloro-1-undecene (175.5 g) and potassium iodide (141.2 g) was stirred and heated under argon. After twenty-one hours at 120°-130° C., the mixture was cooled to room temperature. It was partitioned between hexanes and aqueous sodium hydroxide (105 g of 50% by weight) with sufficient added water to dissolve all salts. The lower aqueous layer (1.75 L) was drained from the upper organic layer (1.2 L) and the aqueous layer was extracted with hexanes (4×200 mL). The combined organic portions were extracted with water (2×50 ml) and concentrated on a rotary evaporator at about 60 mm Hg and 95° C. bath temperature to an amber liquid (345 g). Short-path distillation at 3 mm Hg and 120°-140° C. gave clear liquid (242.6 g, 98.5% pure by gc).
This example shows that halide exchange during the reaction may convert the ineffective 11-chloro-1-undecene into 11-iodo-1-undecene.
EXAMPLE 10
Preparation of 1-(10-undecenyl)-2,2,6,6-tetramethylpiperidine using 11-bromo-1-undecene.
A mixture of TMP (102.2 g), anhydrous lithium bromide (18.6 g), 11-chloro-1-undecene (43.1. g, 99.3 by gc) and 1,3-dimethyl-2-imidazolidinone (199.4 g, H 2 O<0.1%) was stirred under argon. After fifty-five hours at 120°-140° C., the mixture was cooled to room temperature and partitioned between hexanes (150 mL), aqueous sodium hydroxide (25 g of 50% by weight) and sufficient water to dissolve all salts. The upper organic layer (350 mL) was separated and the aqueous layer (400 mL) was extracted with hexanes (4×100 mL). The organic portions were combined and extracted with water (2×30 mL). The organic layer was concentrated on a rotary evaporator at about 60 mm Hg in a water bath at 95° C. to a clear liquid (75.5 g). Short-path distillation at about 3 mm Hg and about 145° C. head temperature gave a colorless liquid (43.6 g, 95.1% purity by gc).
This example shows that halide exchange during the reaction may convert the ineffective 11-chloro-1-undecene into 11-bromo-1-undecene.
EXAMPLE 11
Preparation of 1-(10-undecenyl)-2,2,6,6-tetramethylpiperidine in 1,3-dimethyl-2-imidazolidinone.
A mixture of TMP (386 g), 11-chloro-1-undecene (176 g), potassium iodide (147.5 g) and 1,3-dimethyl-2-imidazolidinone (802 g) was stirred and heated under argon. After nine hours at 120°-140° C., the mixture was cooled to room temperature and partitioned between 50% aqueous sodium hydroxide (101 g), hexanes (500 mL) and sufficient water to dissolve all the salts. The upper organic layer (1 L) was separated and the lower aqueous layer was extracted with hexanes (3×200 mL). The organic portions were combined and extracted with water (2×50 mL). The organic layer was concentrated on a rotary evaporator to an amber liquid (346 g). Short-path distillation at about 1 mm Hg and 107°-154° C. head temperature gave a hazy liquid (239.9 g, 93.9% pure by gc).
EXAMPLE 12
Preparation of 1-(10-undecenyl)-2,2,6,6-tetramethylpiperidine in N-formylmorpholine.
A mixture of TMP (387 g), 11-chloro-1-undecene (173 g), potassium iodide (150 g) and N-formylmorpholine (804 g) was stirred and heated under argon. After twenty hours at 105°-125° C., the mixture was cooled to room temperature and partitioned between 50% aqueous sodium hydroxide (101 g), hexanes (500 mL) and sufficient water to dissolve most of the solids. The upper organic layer (1 L) was separated and the lower aqueous layer (1.7 L) was extracted with hexanes (3×300 mL). The organic portions were combined and extracted with water (2×100 mL). The organic layer was concentrated on a rotary evaporator to an amber liquid (328 g). Short-path distillation at about 1 mm Hg and 107°-122° C. head temperature gave a clear liquid (234.4 g, 97.2% pure by gc).
EXAMPLE 13
Preparation of 1-(10-undecenyl)-2,2,6,6-tetramethylpiperidine in N,N-dimethylformamide.
A mixture of TMP (387 g), 11-chloro-1-undecene (177 g), potassium iodide (145 g) and N,N-dimethylformamide (805 g) was stirred and heated under argon. After twenty-three hours at 120°-130° C., the mixture was cooled to room temperature and partitioned between 50% aqueous sodium hydroxide (128 g), hexanes (500 mL) and sufficient water to dissolve all of the solid. The upper organic layer (1 L) was separated and the lower aqueous layer (1.7 L) was extracted with hexanes (3×200 mL). The organic portions were combined and extracted with water (1×50 mL). The organic layer was concentrated on a rotary evaporator at 95° C. bath temperature and about 60 mm Hg to a brown liquid (343 g). Short-path distillation at about 1 mm Hg and 111°-141° C. head temperature gave a clear liquid (236.6 g, 97.9% pure by gc).
EXAMPLE 14
Preparation of 1-(10-undecenyl)-2,2,6,6-tetramethylpiperidine in N-methylpyrrolidinone (NMP).
A mixture of TMP (387 g), 11-chloro-1-undecene (175 g), potassium iodide (143 g) and NMP (802 g) was stirred and heated under argon. After nineteen hours at 120°-130° C., the mixture was cooled to room temperature and partitioned between 50% aqueous sodium hydroxide (100 g) hexanes (500 mL) and sufficient water to dissolve all of the salts. The upper organic layer (1 L) was separated and the lower aqueous layer (1.7 L) was extracted with hexanes (3×200 mL). The organic portions were combined and extracted with water (2×50 mL). The organic layer was concentrated on a rotary evaporator to a brown liquid (368 g). Short-path distillation at about 3 mm Hg and 120°-152° C. head temperature gave a clear liquid (243.5 g 98.9% pure by gc).
EXAMPLE 15
Preparation of 1-(10-undecenyl)-2,2,6,6-tetramethylpiperidine in N-cyclohexylpyrrolidinone.
A mixture of TMP (385 g), 11-chloro-1-undecene (173 g), potassium iodide (143 g) and N-cyclohexylpyrrolidinone (801 g) was stirred and heated under argon. After twenty-one hours at 120°-130° C., the mixture was cooled to room temperature and partitioned between aqueous sodium hydroxide and hexanes (400 mL) to give three liquid layers. The top brown hexanes layer (800 mL) was separated and the bottom clear colorless aqueous salt layer (250 mL) was drained off. The middle dark brown layer of aqueous N-cyclohexylpyrrolidinone (1400 mL) was extracted with hexanes (3×200 mL). The hexanes portions were combined and extracted with water (3×50 mL) then concentrated on a rotary evaporator to a clear red liquid (407 g). Short-path distillation at about 1 mm Hg gave a fraction boiling at head temperature above 100° C. (230.9 g, 98.0% pure by gc).
EXAMPLE 16
Preparation of 1-(10-undecenyl)-2,2,6,6-tetramethylpiperidine using 11-bromo-1-undecene.
A mixture of TMP (63.8 g), 11-bromo-1-undecene (35.2 g) and N-methylpyrrolidinone (130 g) was stirred and heated under argon. After sixteen hours at 160°-170° C., the mixture was cooled to room temperature and partitioned between hexanes (250 mL) and 50% aqueous sodium hydroxide (15.7 g). Sufficient water was added to dissolve all salts. The upper clear brown hexanes layer (300 mL) was separated and the lower hazy brown aqueous layer (225 mL) was extracted with hexanes (3×80 mL). The combined hexanes portions were extracted with water (1×25 mL) then concentrated on a rotary evaporator to a brown liquid (60.3 g). Short-path distillation at about 3 mm Hg gave a fraction boiling at head temperature 130°-160° C. (35.6 g, 98.4% pure by gc).
EXAMPLE 17
Preparation of 1-(10-undecenyl)-2,2,6,6-tetramethylpiperidine using 11-bromo-1-undecene at lower temperatures.
The procedure of Example 16 was repeated at 120°-130° C. for twenty-four hours. The distillate obtained at about 3 mm Hg and 158°-165° C. head temperature was a clear liquid (35.5 g, 98.1% pure by gc).
EXAMPLE 18
Preparation of 1-(10-undecenyl)-2,2,6,6-tetramethylpiperidine using 11-bromo-1-undecene in N-methylcaprolactam.
The procedure of Example 17 was repeated, using N-methylcaprolactam solvent for twenty-six hours at 120°-130° C. Distillation at about 3 mm Hg and 132°-165° C. head temperature gave a clear liquid (33.6 g, 94.70% pure by gc).
EXAMPLE 19
Preparation of 1-(10-undecenyl)-2,2,6,6-tetramethylpiperidine using 11-bromo-1-undecene without solvent.
A mixture of TMP (195 g) and 11-bromo-1-undecene (105.5 g) was heated and stirred under argon. After sixty-five hours at 160°-175° C. the mixture was cooled to room temperature and partitioned between 50% aqueous sodium hydroxide (39.6 g), hexanes (250 mL) and sufficient water to dissolve all salts. The lower clear colorless aqueous layer (140 mL) was removed. The upper organic layer (500 mL) was extracted with water (2×25 mL) and concentrated on a rotary evaporator at about 60 mm Hg in a 90° C. water bath to a clear orange liquid (174.7 g). Short-path distillation at about 3 mm Hg gave a clear liquid fraction boiling at 130°-161° C. (82.2 g, 96.5% pure by gc).
This example shows that yield is reduced and reaction time is prolonged without solvent.
The compounds made by my process are useful as precursors of light stabilizers in plastics. | Fully hindered secondary amines, typically tetramethyl piperidine, are reacted with terminally unsaturated electrophilic compounds having at least five carbon atoms to obtain tertiary hindered amines. The reaction is conducted with an excess of secondary amine, preferably in the presence of a specified solvent such as N-methyl pyrrolidinone. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2016-088331, filed on Apr. 26, 2016, the entire contents of which are incorporated herein by reference.
BACKGROUND
1. Field of the Invention
[0002] The present invention relates to a manufacturing method, a manufacturing apparatus and a manufacturing jig of a trim cover surface material.
2. Description of the Related Art
[0003] A vehicle seat typically includes a cushioning pad and a trim cover that covers the cushioning pad, and the trim cover is made by sewing a plurality of surface materials. Leather (natural leather, synthetic leather) is used as an example of the surface material, and, from a view of improving breathability and design, a large number of through holes may be formed at the leather by a predetermined pattern. Furthermore, from a view of improving design of the seat, stitches may be formed at the surface material, and the stitches avoid the through holes of the surface material and are formed at the gap part between through hole patterns (for example, refers to JP-A-2013-162957).
[0004] The trim cover surface material described in JP-A-2013-162957 is formed by laminating a wadding material made of foaming resin such as slab urethane on an outer material of leather which is formed with a plurality of through holes, and the leather and the wadding material are bonded. To secure the breathability of the leather, the leather is bonded with the wadding material at the outer periphery except where the through holes are formed. The stitches are formed at the gap part between the through hole patterns of the surface material.
[0005] The stitches of the surface material are typically formed by using a sewing machine driven according to a program. In automatic sewing using this kind of sewing machine, the sewed object such as the surface material is installed on the sewing machine while, for example, the outer periphery is held by a frame-like jig, and slack is removed (for example, refers to JP-B-H07-38907).
[0006] The surface material described in JP-A-2013-162957 is formed by laminating the wadding material on the leather which is formed with through holes beforehand, but, for example, when the leather which are formed with the through holes beforehand are procured from outside, a relatively long time elapses from when the leather is formed with the through holes until the stitches are formed at the surface material.
[0007] If the elapsed time after the leather is formed with the through holes becomes long, the leather deforms under the influence of temperature and humidity, and due to the deformation of the leather, the through hole patterns may be deviated. When the through hole patterns are deviated, misalignment of the stitches which the surface material is formed with by automatic sewing and the through hole patterns may occur, and design may be spoiled.
[0008] For the surface material described in JP-A-2013-162957, the leather is bonded with the wadding material at the outer periphery except where the through holes are formed, but when the stitches are formed by automatic sewing, the outer periphery of the surface material is held by a jig. Therefore, the leather and the wadding material are bonded, and then the surface material whose leather and wadding material are bonded is set on the jig, but an error in the positioning of the surface material to the jig may occur, and when the leather is deformed, the positioning of the surface material becomes further harder. When the error occurs in the positioning of the surface material, misalignment of the stitches and the through holes may occur and design may be spoiled.
SUMMARY
[0009] The present invention is made in view of the above circumstances, and the object of the present invention is to provide a manufacturing method and a manufacturing apparatus of a trim cover surface material and a manufacturing jig which can inhibit the misalignment of stitches and through hole patterns.
[0010] According to an aspect of the present invention, there is provided a manufacturing method of a trim cover surface material, the trim cover surface material including: an outer material which is formed with a plurality of through holes by a predetermined pattern; and a wadding material laminated on the outer material, the trim cover surface material being formed with stitches that sew together the outer material and the wadding material at gap portions between through hole patterns, the manufacturing method including: providing a jig including: a first frame configured to hold an outer periphery of the outer material; and a second frame configured to hold an outer periphery of the wadding material by overlapping the wadding material on the outer material which is held by the first frame; holding the outer periphery of the outer material with the first frame of the jig; forming the through holes at the outer material which is held by the jig; holding the outer periphery of the wadding material with the second frame of the jig while the outer material is held by the first frame of the jig; and forming the stitches at the outer material and the wadding material which are overlapped and held by the jig.
[0011] According to another aspect of the present invention, there is provided a manufacturing apparatus of a trim cover surface material, the trim cover surface material including: an outer material which is formed with a plurality of through holes by a predetermined pattern; and a wadding material laminated on the outer material, the trim cover surface material being formed with stitches that sew together the outer material and the wadding material at gap portions between through hole patterns, the manufacturing apparatus including: a drilling machine and a sewing machine which are installed sequentially on a production line; and a jig which holds the outer material and the wadding material, wherein: the jig includes: a first frame configured to hold an outer periphery of the outer material; and a second frame configured to hold an outer periphery of the wadding material by overlapping the wadding material on the outer material which is held by the first frame; the drilling machine includes an installing part on which the jig is installed; the drilling machine forms the through holes at the outer material which is held by the jig which is installed on the installing part; the sewing machine includes an installing part on which the jig is installed; and the sewing machine forms the stitches at the outer material and the wadding material which are held by the jig which is installed on the installing part.
[0012] According to still another aspect of the present invention, there is provided a manufacturing jig of a trim cover surface material, the trim cover surface material including: an outer material which is formed with a plurality of through holes by a predetermined pattern; and a wadding material laminated on the outer material, the trim cover surface material being formed with stitches that sew together the outer material and the wadding material at gap portions between through hole patterns, the manufacturing jig including: a first frame configured to hold an outer periphery of the outer material; and a second frame configured to hold an outer periphery of the wadding material by overlapping the wadding material on the outer material which is held by the first frame.
[0013] According to the present invention, the misalignment of stitches and through hole patterns can be inhibited.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawing which is given by way of illustration only, and thus is not limitative of the present invention and wherein:
[0015] FIG. 1 is a perspective view of a vehicle seat to describe an embodiment of the present invention;
[0016] FIG. 2 is a sectional view of a surface material of FIG. 1 ;
[0017] FIG. 3 is a schematic diagram of a manufacturing apparatus of the surface material of FIG. 1 ;
[0018] FIG. 4 is a perspective view of a manufacturing jig of the surface material of FIG. 1 ;
[0019] FIG. 5 is a perspective view which shows that the manufacturing jig of FIG. 4 is opened;
[0020] FIG. 6A is a schematic diagram to describe a manufacturing process of the surface material of FIG. 1 ;
[0021] FIG. 6B is a schematic diagram to describe a manufacturing process of the surface material of FIG. 1 ;
[0022] FIG. 6C is a schematic diagram to describe a manufacturing process of the surface material of FIG. 1 ;
[0023] FIG. 6D is a schematic diagram to describe a manufacturing process of the surface material of FIG. 1 ; and
[0024] FIG. 6E is a schematic diagram to describe a manufacturing process of the surface material of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIG. 1 shows an example of the vehicle seat to describe an embodiment of the present invention.
[0026] A vehicle seat 1 shown in FIG. 1 includes a seat cushion 2 which forms a bearing surface portion, a seat pack 3 which forms a back rest portion, and a head rest 4 which supports the head of a passenger who is seated on the seat. Each of the seat cushion 2 , the seat pack 3 and the head rest 4 has a cushioning pad made of foam material such as urethane foam, and a frame which supports the cushioning pad.
[0027] The cushioning pad of the seat cushion 2 and the cushioning pad of the seat pack 3 are covered integrally with a trim cover 5 , and the cushioning pad of the head rest 4 is also covered with the trim cover 5 or another trim cover.
[0028] The cushioning pad of the seat cushion 2 and the cushioning pad of the seat pack 3 may be covered by individual trim covers, respectively, and when the head rest 4 is a fixed head rest and is formed integrally with the seat pack 3 , the cushioning pad of the head rest 4 may be covered integrallly with the cushioning pad of the seat pack 3 by one trim cover, or may be covered integrallly with the cushioning pad of the seat cushion 2 and the cushioning pad of the seat pack 3 by one trim cover.
[0029] The trim cover 5 is formed by sewing and joining a plurality of surface materials, and among the plurality of surface materials that form the trim cover 5 , for example, a surface material 6 which covers the central portion in the widthwise direction of the front surface of the seat pack 3 , and a surface material 7 which covers the central portion in the widthwise direction of the bearing surface of the seat cushion 2 , have a plurality of through holes 8 that are formed by a predetermined pattern and stitches 9 which are formed at the gap portion between the through hole patterns. In the shown example, a large number of through holes 8 are formed by a pattern in which a quadrangle is formed by one group of through holes 8 which includes four through holes, and stitches 9 are formed into a mesh shape to sew the gap between adjacent quadrangles.
[0030] The pattern of the through holes 8 and the stitches 9 is not limited to the shown example, and the through holes 8 and the stitches 9 may be provided at a surface material that covers other sites of the seat cushion 2 and the seat pack 3 .
[0031] FIG. 2 shows the constitution of the surface material 6 .
[0032] The surface material 6 is formed of an outer material 10 and a wadding material 11 which is laminated on the outer material 10 . The through holes 8 are formed only at the outer material 10 . The stitches 9 are formed across the outer material 10 and the wadding material 11 , and the outer material 10 and the wadding material 11 are sewed together by the stitches 9 .
[0033] It is preferable that the outer material 10 is a material which will not break even if the through holes 8 are formed, and, for example, leather (natural leather, synthetic leather) or a nonwoven fabric is preferred. The wadding material 11 has cushion property, and, for example, resin foam such as soft urethane foam is preferred.
[0034] For the purpose of, such as, reinforcing the surface material 6 , a back material may be further laminated on the wadding material 11 , and in this case, the outer material 10 , the wadding material 11 and the back material are sewed together by the stitches 9 . An appropriate material such as cloth (textile, knitting, and nonwoven fabric) or resin film is used for the back material depending on the purpose.
[0035] The surface material 7 is constructed like the surface material 6 .
[0036] FIG. 3 shows the constitution of a manufacturing apparatus of the surface materials 6 , 7 .
[0037] The manufacturing apparatus 100 of the surface materials 6 , 7 includes a drilling apparatus 110 and a sewing machine 120 , which are installed sequentially on a production line, and a jig 130 . The jig 130 is so constructed that the outer material 10 and the wadding material 11 can be held, and is moved from the drilling apparatus 110 to the sewing machine 120 . The movement of the jig 130 may be performed, for example, by a worker and may be performed by a conveyance machine.
[0038] The drilling machine 110 has an installing part 111 where the jig 130 is installed, a head 112 to which a punch for forming through holes is mounted, and a base 113 which supports the installing part 111 and the head 112 . The installing part 111 has a flat table 114 on which the jig 130 is placed and a slider 115 which moves the jig 130 on the table 114 in the X direction and the Y direction. The slider 115 is driven according to a program corresponding to the pattern of the through holes 8 formed at the outer material 10 .
[0039] The sewing machine 120 has a flat installing part 121 on which the jig 130 is placed, a head 122 to which a sewing needle for forming stitches is mounted, and a base 123 which supports the installing part 121 and the head 122 . The installing part 121 has a flat table 124 on which the jig 130 is placed, and a slider 125 which moves the jig 130 on the table in the X direction and the Y direction. The slider 125 is driven according to a program corresponding to the pattern of the stitches 9 formed across the outer material 10 and the wadding material 11 .
[0040] The jig 130 , the slider 115 of the drilling machine 110 and the slider 125 of the sewing machine 120 are provided respectively with engaging parts to position the jig 130 relative the head 112 on the table 114 of the drilling machine 110 , and to position the jig 130 relative to the head 122 on the table 124 of the sewing machine 120 .
[0041] In the shown example, the jig 130 is formed into a roughly rectangular frame shape, and the slider 115 and the slider 125 are respectively formed into a bar-like shape along the outer periphery of one side of the four sides of the jig 130 . The engaging part of the jig 130 is formed of a pair of chucks 136 which are arranged to be spaced at the outer periphery of one side, and which are formed with roughly U-like engaging slots, respectively. The engaging part of the slider 115 is formed of a pair of engaging pins 116 which are fitted and held in the engaging slots of the pair of chucks 136 . The engaging part of the slider 125 is formed of a pair of engaging pins 126 which are fitted and held in the engaging slots of the pair of chucks 136 .
[0042] While the jig 130 and the outer material 10 held on the jig 130 are positioned relative to the head 112 on the table 114 of the drilling machine 110 , when the slider 115 is driven, the head 112 is moved relative to the jig 130 , and the through holes 8 are formed at the outer material 10 by a predetermined pattern.
[0043] While the jig 130 and the outer material 10 and the wadding material 11 which are held by the jig 130 are positioned relative to the head 122 on the table 124 of the sewing machine 120 , when the slider 125 is driven, the head 122 is moved relative to the jig 130 , and the stitches 9 are formed at the outer material 10 and the wadding material 11 by a predetermined pattern.
[0044] FIGS. 4 and 5 show the detailed constitution of the jig 130 .
[0045] The jig 130 has a roughly rectangular first frame 131 which holds the outer material 10 and a roughly rectangular second frame 132 which holds the wadding material 11 . The first frame 131 is placed inside the second frame 132 , and the first frame 131 and the second frame 132 are connected to be openable and closeable through a pair of hinges 135 .
[0046] The four sides of the first frame 131 are provided with clamps 133 which can be opened and closed, respectively, and the first frame 131 holds the outer material 10 by clamping the outer periphery of the outer material 10 between the frame of the first frame 131 and the clamps 133 of the four sides.
[0047] Similarly, the four sides of the second frame 132 are provided with clamps 134 which can be opened and closed, respectively, and the second frame 132 holds the wadding material 11 by clamping the outer periphery of the wadding material 11 between the frame of the second frame 132 and the clamps 134 of the four sides.
[0048] According to the above-mentioned constitution, by rotating the first frame 131 which holds the outer material 10 relative to the second frame 132 to open the first frame 131 and the second frame 132 , without removing the outer material 10 from the first frame 131 , the wadding material 11 can be held by the second frame 132 . Then by closing the first frame 131 and the second frame 132 again, the outer material 10 and the wadding material 11 can be overlapped.
[0049] FIGS. 6A to 6E show manufacturing processes of the surface materials 6 , 7 using the manufacturing apparatus 100 .
[0050] At first, as shown in FIG. 6A , only the outer material 10 is held by the first frame 131 of the jig 130 . Then, as shown in FIG. 6B , the jig 130 which holds only the outer material 10 with the first frame 131 is installed on the drilling machine 110 of the manufacturing apparatus 100 shown in FIG. 3 , and the outer material 10 is formed with a lot of through holes 8 by a predetermined pattern.
[0051] Then, as shown in FIG. 6C , the first frame 131 which holds the outer material 10 is rotated relative to the second frame 132 to open the first frame 131 and the second frame 132 , and the wadding material 11 is held by the second frame 132 . Then, as shown in FIG. 6D , the first frame 131 which holds the surface material 10 and the second frame 132 which holds the wadding material 11 are closed again, and, the outer material 10 and wadding material 11 are overlapped.
[0052] Then, as shown in FIG. 6E , the jig 130 which holds the outer material 10 and the wadding material 11 is installed on the sewing machine 120 of the manufacturing apparatus 100 shown in FIG. 3 , and the outer material 10 and the wadding material 11 are formed with the stitches 9 , which sew the outer material 10 and the wadding material 11 together, at the gap portion between the through hole patterns.
[0053] According to the above method of manufacturing the surface materials 6 , 7 , after the through holes 8 are formed at the outer material 10 which is held by the jig 130 , the wadding material 11 is held by the jig 130 without removing the outer material 10 from the jig 130 , and then the stitches 9 are formed at the outer material 10 and the wadding material 11 held by the jig 130 . Because continuously from the formation of the through holes 8 until the formation of the stitches 9 , the jig 130 keeps holding the outer material 10 , positioning error of the outer material 10 can be reduced, and misalignment of the stitches 9 and the through hole patterns can be inhibited. | A manufacturing method of a trim cover surface material, includes: providing a jig including a first frame configured to hold an outer periphery of an outer material and a second frame configured to hold an outer periphery of a wadding material by overlapping the wadding material on the outer material which is held by the first frame; holding the outer periphery of the outer material with the first frame of the jig; forming through holes at the outer material which is held by the jig; holding the outer periphery of the wadding material with the second frame of the jig while the outer material is held by the first frame of the jig; and forming stitches at the outer material and the wadding material which are overlapped and held by the jig. | 3 |
TECHNICAL FIELD
The present invention relates generally to rifles, and more particularly to rifle periscopes for attachment to rifles and providing an indirect line of vision.
BACKGROUND OF THE INVENTION
Rifle periscopes are known for providing users with an indirect line of vision for viewing surrounding areas without exposing the users to those areas or any persons within those areas. In addition, the indirect line of vision also allows the users to fire their rifles from protected positions.
Current rifle periscopes are mounted on the rifles in a manner that permits the users to utilize existing sight assemblies integrated within the rifles. A drawback of these rifle periscopes is that they obstruct normal use of the sight assemblies when the users wish to take a direct line of vision ordinarily taken when the users do not have to seek cover. In other words, a part of the periscope may block at least one of the sight assemblies. Furthermore, some rifle periscopes require the simultaneous use of two or more movable mirrors. As a result, the design of the periscope is somewhat complicated thereby increasing manufacturing time and costs associated therewith.
Therefore, it would be desirable to provide a rifle periscope having a simple structure that provides for an indirect line of vision without obstructing the use of existing sight assemblies integrated within the rifle.
SUMMARY OF THE INVENTION
The present invention provides a rifle periscope that allows for an indirect line of vision without obstructing normal use of existing sight assemblies integrated within the rifle.
The rifle periscope includes a removable mount assembly for attachment to the barrel of a rifle in a manner that allows for an unobstructed direct line of vision when using the sight assemblies. The removable mount assembly has a first surface and a second surface. The first surface has a viewing mirror attached thereto for providing an indirect line of vision that is outside of a firing range of the rifle. The second surface has a targeting mirror attached thereto for providing an indirect line of vision that is within a firing range of the rifle.
One advantage of the present invention is that a user may view the surrounding area from a protected position without exposing himself to any threats within the viewed area.
Another advantage of the present invention is that a user may fire his rifle from a protected position without exposing himself to the target or other persons in the surrounding area.
Yet another advantage of the present invention is that the rifle periscope does not obstruct a direct line of vision when making normal use of the sight assemblies integrated within the rifle.
Other advantages of the present invention will become apparent when viewed in light of the detailed description of the preferred embodiment when taken in conjunction with the attached drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a rifle with a rifle periscope mounted thereon, in accordance with a preferred embodiment of the present invention;
FIG. 2 is a view of an unobstructed direct line of vision taken when using a rifle having a rifle periscope mounted thereon, in accordance with a preferred embodiment of the present invention;
FIG. 3A is a perspective view of a rifle periscope, in accordance with a preferred embodiment of the present invention;
FIG. 3B is an exploded view of a rifle periscope, in accordance with a preferred embodiment of the present invention;
FIG. 4 is a bottom plan view of a mirror base, in accordance with a preferred embodiment of the present invention;
FIG. 5 is a top view of a rifle periscope being used to view a target, in accordance with a preferred embodiment of the present invention;
FIG. 6 is a top view of a rifle periscope being used to fire at a target, in accordance with a preferred embodiment of the present invention; and
FIG. 7 is a perspective view of a cover for a rifle periscope, in accordance with a preferred embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following figures, the same reference numerals are used to identify the same components in the various views.
Referring to FIGS. 1 and 2, there are generally shown views of a rifle 10 with a rifle periscope 30 mounted thereon, in accordance with a preferred embodiment of the present invention. The rifle 10 preferably is a military rifle having a trigger 12 adjacent to a pistol grip 14 . The pistol grip 14 is intended to provide the user with a handhold for maintaining control of the rifle 10 while he pulls the trigger 12 .
The rifle 10 also preferably includes a forestock 16 that is intended to provide a handhold for the user's other hand. Of course, the pistol grip 14 and forestock 16 may be used to handle the rifle 10 in various circumstances other than while firing the rifle 10 .
The rifle 10 further includes a front sight assembly 18 and a rear sight windage drum 20 for aiming at a target. The user may aim the rifle 10 by taking a direct line of vision with the front sight assembly 18 and the rear sight windage drum 20 . In other words, the user may align the front sight assembly 18 with the rear sight windage drum 20 on the desired target.
The rifle 10 has a barrel 22 that directs rounds of ammunition when they are fired from the rifle 10 . As best shown in FIG. 2, the rifle periscope 30 is mounted on a portion of the barrel 22 in manner that does not obstruct a direct line of vision taken with the front sight assembly 18 and the rear windage drum 20 . In particular, the rifle periscope 30 is preferably mounted on the barrel 22 between the front sight assembly 18 and a flash suppressor 24 of the rifle 10 . However, it is understood that the rifle periscope 30 may be secured to other suitable portions of the rifle 10 that allow the user to view and fire the rifle 10 from protected positions.
Although FIGS. 1 and 2 show a military rifle, it is understood that the rifle periscope 30 may be used for various other types of rifles.
Referring primarily to FIGS. 3A and 3B, there are shown, respectively, a perspective view and an exploded view of the rifle periscope 30 , in accordance with a preferred embodiment of the present invention. The rifle periscope 30 includes a removable mount assembly 32 for attachment to the barrel 22 of the rifle 10 .
In the preferred embodiment, the removable mount assembly 32 includes a mirror base 34 having a curved surface 36 (as best shown in FIG. 4) for mating to the bare 22 of the rifle 10 . The removable mount assembly 32 preferably also includes a backing plate 38 that has an opposing curved surface 40 for mating to the barrel 22 . The mirror base 34 and the backing plate 38 preferably are both comprised of aluminum. However, it is understood that the mirror base 34 and/or the backing plate 38 can instead be made of plastic, nylon, rubber or a variety of other suitable materials.
Preferably, the removable mount assembly 32 is secured to the barrel 22 by attaching the backing plate 38 to the mirror base 34 in a manner that clamps the barrel 22 between the curved surface 36 of the mirror base 34 and the opposing curved surface 40 of the backing plate 38 .
The backing plate 38 is preferably engaged to the mirror base 34 by a plurality of screw fasteners 42 . The screw fasteners 42 are inserted through openings 44 formed in the backing plate 38 and thereafter fastened to threaded holes 46 formed in the mirror base 34 .
Of course, the rifle periscope 30 may be attached to the barrel 22 of the rifle 10 by a variety of other suitable fasteners. For example, in an alternative embodiment, a snap-fit engagement between the backing plate 38 and the mirror base 34 may allow for easier attachment and detachment of the rifle periscope 30 from the barrel 22 . Moreover, a mere strap may be used to secure the rifle periscope 30 to the barrel 22 . It is understood that various other fasteners may be used to attach the rifle periscope 30 to the barrel 22 .
The mirror base 34 preferably has a first surface 48 intended to receive a viewing mirror 50 . As best shown in FIG. 5, the viewing mirror 50 is positioned in a manner that provides the user with an indirect line of vision for safely viewing objects that are beyond a firing range of the rifle 10 . The viewing mirror 50 may be made of aluminum, plastic, or other suitable materials that provide sufficient reflection.
Furthermore, the rifle periscope 30 may be rotated about a longitudinal axis of the barrel 22 thereby permitting the user to employ the rifle periscope 12 for viewing surrounding areas in various circumstances. In this regard, the rifle periscope 30 may be rotated at an angle 26 from the horizon (as shown in FIG. 1 ). There are at least two situations in which the user may wish to rotate the rifle periscope 30 .
First, the user may wish to have an indirect line of vision for viewing surrounding areas at a similar height level as the user's eyes. For example, a user holding the rifle 10 near eye level may only need to rotate the rifle periscope 30 a relatively small angle from the horizon. In contrast, a user holding the rifle near waist level may need to rotate the rifle periscope at a larger angle from the horizon.
In another situation, the user may rotate the rifle periscope 30 at various angles for viewing above or below the level of his eyes. For example, a user may rotate the rifle periscope at a relatively large angle to have an indirect line of vision for viewing an object or person located uphill.
Referring to FIGS. 3A, 3 B, and 6 , the mirror base 34 also includes a second surface 52 intended to receive a targeting mirror 54 . The targeting mirror 54 is positioned on the barrel 22 in a manner that provides the user with an indirect line of vision for aiming and firing at a target. Preferably, the targeting mirror 54 is positioned about 45 degrees from a longitudinal axis of the barrel 22 so as to allow the user to aim and fire the rifle 10 from a side of the rifle 10 . Similar to the viewing mirror 50 , the targeting mirror 54 may be made of aluminum, plastic, or other suitable materials that provide sufficient reflection.
The targeting mirror 54 preferably has one or more markings for providing the user with a periscope sight. The periscope sight allows the user to aim and fire his rifle 10 at a target from a protected position. These markings preferably include a flash suppressor profile line 56 and a center bore line 58 . The flash suppressor profile line 56 and the center bore line 58 intersect at an intersection point 60 intended to serve as the periscope sight.
The user preferably holds the rifle 10 sideways to aim and fire the rifle 10 . In particular, the user may hold the forestock 16 in his upwardly facing left palm and grasp the pistol grip 14 with the fingers of his right hand (as shown in FIG. 6 ).
The user may then utilize the targeting mirror 54 to aim the rifle 10 . This is accomplished by positioning the rifle 10 in a manner that allows the user to see that the flash suppressor profile line 56 is outlining the actual profile of the flash suppressor 24 . Simultaneously, the user may train the intersection point 60 on the desired target thereby aiming the rifle 10 at that target. The user may then pull the trigger 12 with the thumb on his right hand.
Although this example demonstrates a user holding a rifle 10 for shooting a target positioned to his left, it is understood that the user may utilize a similar technique for shooting a target positioned to his right. Preferably, the intersection point 60 serves as the periscope sight as long as the user sees that the flash suppressor profile line 56 outlines the actual profile of the flash suppressor 24 .
Referring now to FIG. 7, in the preferred embodiment, the rifle periscope also includes a cover 62 intended to conceal the viewing mirror 50 and the targeting mirror 54 when they are not in use. The cover 62 is preferably secured to the removable mount assembly 32 by a compression fit and alternatively by a snap fit or various other suitable fastening methods.
Furthermore, the cover 62 preferably is attached to the removable mount assembly by a cord 64 so as to dangle the cover 62 therefrom when it is not being used to conceal the viewing mirror 50 and the targeting mirror 54 . In particular, the mirror base 34 preferably has a recess 66 formed therein (as best shown in FIG. 4) for receiving an anchor 68 integrated within an end of the cord 64 . The anchor 68 is held within the recess 66 when the curved surface 36 of the mirror base 34 is mated to the barrel 22 .
While particular embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims. | A rifle periscope ( 30 ) is provided for allowing an indirect line of vision without obstructing use of existing sight assemblies ( 18, 20 ) mounted on a rifle ( 10 ). The rifle periscope ( 30 ) includes a removable mount assembly ( 32 ) attached to a barrel ( 22 ) of the rifle ( 22 ) so as to allow for an unobstructed direct line of vision when using the sight assemblies ( 18, 20 ). The removable mount assembly ( 32 ) has a first surface ( 48 ) and a second surface ( 52 ). The first surface ( 48 ) has a viewing mirror ( 50 ) attached thereto for to providing a first indirect line of vision that is outside of a firing range of the rifle ( 10 ). The second surface ( 52 ) has a targeting mirror ( 54 ) attached thereto for providing a second indirect line of vision that is within a firing range of said rifle ( 10 ). | 5 |
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention relates to an ink jet recording apparatus having an ink jet recording head for recording by ejecting ink onto a recording medium, and a recovery device for recovering the function of the recording head.
2. Description of Related Art
In conventional ink jet recording apparatuses for recording by ejecting ink from nozzles, it is necessary to place a cap on an ink jet head when not in use because ink on a nozzle surface is likely to dry and solidify causing an ink ejection failure. In order to recover from an ink ejection failure or prevent an ink ejection failure, there is a need to perform maintenance of an ink jet head. There are several maintenance methods for ink jet heads, for example, a purging method in which nozzle clogging is eliminated by, for example, drawing dry ink from an ink jet head nozzle, or a wiping method in which an ink-wet nozzle surface is wiped. As a device for facilitating such an ink jet head maintenance operation, U.S. Pat. No. 4,543,591 discloses a maintenance device for an ink jet recording apparatus, which immediately performs the capping of a nozzle and the subsequent ink drawing at freely selectable timings by operation of a lever in one direction.
However, if the aforementioned maintenance device is incorporated into a head recovery device, the operability improves, but unnecessary ink consumption may result through improper operation.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide an ink jet recording apparatus that prevents improper operation of a head recovery device and, thereby, eliminates unnecessary ink consumption, without degrading operability.
To achieve the aforementioned object, the invention provides an ink jet recording apparatus including a recording head for recording by ejecting ink onto a recording medium, a head recovery device that recovers a function of the recording head, a first switch for operating the head recovery device, and an inhibition device that inhibits operation of the head recovery device under a predetermined condition.
Because the inhibition device inhibits operation of the head recovery device under a predetermined condition, unintentional or accidental operation of the head recovery device can be prevented even if the switch for operating the head recovery device is operated in such an occasion. Therefore, unnecessary ink consumption is prevented.
The inhibition device may have a second switch provided aside from the first switch, and the inhibition device cancels the inhibition of operation of the head recovery device when the first switch and the second switch are operated.
The inhibition device may cancel the inhibition of operation of the head recovery device when the first switch is continually operated.
The inhibition device may have a timer for measuring time elapsed after a previous operation of the head recovery device, and the inhibition device cancels the inhibition of operation of the head recovery device when the time measured by the timer reaches a predetermined length of time.
The inhibition device may have a timer for measuring time elapsed after a previous operation of the recording head, and the inhibition device cancels the inhibition of operation of the head recovery device when the time measured by the timer reaches a predetermined length of time.
The inhibition device may have a timer for measuring time elapsed after a main switch of the ink jet recording apparatus is turned on, and the inhibition device cancels the inhibition of operation of the head recovery device when the time measured by the timer reaches a predetermined length of time.
The inhibition device may have a counter for counting an amount of printed characters that are printed by the recording head after a previous operation of the head recovery device, and the inhibition device cancels the inhibition of operation of the head recovery device when the count by the counter reaches a predetermined value.
The inhibition device may have a sensor for counting an amount of ink that is used by the recording head after a previous operation of the head recovery device, and the inhibition device cancels the inhibition of operation of the head recovery device when the count provided by the sensor reaches a predetermined amount.
The inhibition device may have a counter for counting a number of times that the recording head prints after a previous operation of the head recovery device, and wherein the inhibition device cancels the inhibition of operation of the head recovery device when the count by the counter reaches a predetermined value.
The inhibition device may have a counter for counting an amount of printed characters that are printed by the recording head after a main switch of the ink jet recording apparatus is turned on, and the inhibition device cancels the inhibition of operation of the head recovery device when the count by the counter reaches a predetermined amount.
The inhibition device may have a counter for counting an amount of ink that is used by the recording head after a main switch of the ink jet recording apparatus is turned on, and the inhibition device cancels the inhibition of operation of the head recovery device when the count by the counter reaches a predetermined amount.
The inhibition device may have a counter for counting a number of times that the recording head prints after a main switch of the ink jet recording apparatus is turned on, and the inhibition device cancels the inhibition of operation of the head recovery device when the count by the counter reaches a predetermined value.
The inhibition device may have a sensor for measuring an amount of ink remaining in the recording apparatus, and the inhibition device prevents cancellation of the inhibition of operation of the head recovery device when the amount measured by the sensor has become equal to or lower than a predetermined amount. With this structure, when the ink remaining in the recording apparatus has become equal to or less than the predetermined amount, it becomes impossible to operate the recovery device. This structure eliminates an inconvenient incident wherein the recovery device is operated when there is only a small amount of ink remaining, so that the remaining ink is completely consumed. That is, even when there is only a little ink left, it is possible to continue recording while preventing the recovery device from operating, even though minor problems occur in recording quality.
The inhibition device may have a second counter for counting a number of operations of the recovery device, and the inhibition device prevents cancellation of the inhibition of operation of the head recovery device when the count by the second counter has reached a predetermined value. With this structure, when the number of operations of the recovery device has reached the predetermined number, it becomes impossible to operate the recovery device. This structure prevents an unnecessarily great number of recovery operations and, therefore, prevents unnecessary ink consumption.
The ink jet recording apparatus may further include a recovery permission device that forcibly cancels a condition setting for the inhibition by the inhibition device. This structure allows the head recovery device to be driven even under the inhibition condition, if a recovery operation is needed.
The ink jet recording apparatus may further have an inhibition condition setting device that enables selection of whether to set a condition for the inhibition by the inhibition device. This structure makes it possible for a user to select a condition for the inhibition in accordance with the working conditions, thereby improving usability and reducing unnecessary ink consumption.
The ink jet recording apparatus may be a small-size manually-driven printing apparatus that records by ejecting ink onto a recording medium when the apparatus is manually moved over the recording medium.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will be described in detail with reference to the following figures wherein:
FIG. 1 is an exterior view of a manually-driven printing apparatus according to an embodiment of the invention;
FIG. 2 is a sectional view of the manually-driven printing apparatus shown in FIG. 1;
FIG. 3 is a bottom view of the manually-driven printing apparatus shown in FIG. 1;
FIG. 4 is a fragmental sectional view of the manually-driven printing apparatus, with a cap member being at a capping position;
FIG. 5 is a fragmental sectional view of the manually-driven printing apparatus, with the cap member being at a withdrawn position;
FIG. 6 is a block diagram of a control system of a recording apparatus according to a first embodiment;
FIG. 7 is a flowchart of a printing control of the recording apparatus;
FIG. 8 is a flowchart of a subroutine for suction operation by a suction mechanism according to the first embodiment;
FIG. 9 is a flowchart of a subroutine for suction operation by a suction mechanism according to a second embodiment;
FIG. 10 is a block diagram of a control system of a recording apparatus according to a third embodiment;
FIG. 11 is a flowchart of a printing control according to the third embodiment;
FIG. 12 is a flowchart of a printing control according to a fourth embodiment;
FIG. 13 schematically illustrates recording areas in a RAM;
FIG. 14 is a flowchart of a printing control according to a fifth embodiment;
FIG. 15 is a block diagram of a control system of a recording apparatus according to a sixth embodiment;
FIG. 16 is a flowchart of a printing control according to the sixth embodiment;
FIG. 17 is a flowchart of a printing control according to a seventh embodiment;
FIG. 18 is a flowchart of a printing control according to an eighth embodiment;
FIG. 19 is a flowchart of a printing control according to a ninth embodiment;
FIG. 20 is a flowchart of a printing control according to a tenth embodiment;
FIG. 21 is a flowchart of a printing control according to an eleventh embodiment;
FIG. 22 is a flowchart of a printing control according to a twelfth embodiment;
FIG. 23 is an exterior view of a manually-driven printing apparatus according to a further embodiment of the invention; and
FIG. 24 is an exterior view of a manually-driven printing apparatus according to a still further embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Preferred embodiments of the invention will be described in detail hereinafter with reference to the accompanying drawings.
A manually-driven printing apparatus according to a preferred embodiment of the invention will first be described. FIG. 1 is an exterior view, FIG. 2 is a sectional view, and FIG. 3 is a bottom view of a manually-driven printing apparatus 1 . The manually-driven recording apparatus 1 includes a recording mechanism 3 having an ink jet recording head 2 , a displacement detecting mechanism 4 for detecting the amount of movement of the recording apparatus 1 , an infrared photo-diode 5 and an infrared-emitting diode 6 for infrared communications with an external device, a control circuit board 7 carrying a control portion 7 a for controlling the recording mechanism 3 , and a battery 8 which is a secondary battery, i.e., a rechargeable power source, and the like. The control portion 7 a controls the transmission and reception of the diodes 5 , 6 , and controls the driving of the recording mechanism 3 on the basis of an encoder signal from the displacement detecting mechanism 4 . The aforementioned components are electrically connected and compactly housed in a body case 10 . The manually-driven recording apparatus 1 is capable of recording characters and graphic images on a recording sheet (recording medium) 11 by manually moving the recording apparatus 1 on the recording sheet 11 in a printing direction.
The body case 10 is a synthetic resin-made case having the shape of a hollow prism with a bottom opening. When viewed two-dimensionally, the body case 10 has a generally rectangular shape. The infrared photo-diode 5 and the infrared-emitting diode 6 are disposed in an upper end wall of the body case 10 . Disposed in a front wall, i.e., the wall on the rear of the body case 10 relative to the printing direction, of the body case 10 are a power switch 12 , a print instruction switch 13 for instructing permission and inhibition of a recording operation, and a suction switch 14 for operating a suction mechanism (described later) which is a head recovery device. The suction switch 14 constitutes a first switch for operating the head recovery device. The print instruction switch 13 constitutes a second switch for canceling the inhibition of operation of the head recovery device.
The recording mechanism 3 will now be described in detail. An ink tank 15 containing an ink absorbent impregnated with a recording ink is detachably disposed in a lower end portion of the body case 10 . The ink tank 15 is connected to the recording head 2 . The recording head 2 has, for example, two rows of downward-directed ejection nozzles (not shown) that extend in a transverse direction perpendicular to the recording direction. Each row includes, for example, thirty-two ejection nozzles. Ink is supplied from the ink tank 15 to each ejection nozzle of the recording head 2 , and ink droplets are ejected selectively from ejection nozzles to the recording sheet 11 placed below.
The displacement detecting mechanism 4 is designed to detect the amount of movement of the manually-driven recording apparatus 1 relative to the recording sheet 11 . A timing roller 21 made of rubber, extending close to the recording head 2 in the transverse direction is rotatably supported by a journal shaft 22 to a lower end portion of the body case 10 . A gear 23 , in contact with a portion of the timing roller 21 , is rotatably journaled to the body case 10 . A circular encoder plate 24 rotatable by the gear 23 is rotatably journaled to the body case 10 . A plurality of slits are formed in an outer peripheral portion of the encoder plate 24 . A photo-sensor 25 having a light-emitting portion and a light-receiving portion is disposed so that the light-emitting portion and the light-receiving portion respectively face opposite surfaces of the outer peripheral portion of the encoder plate 24 . A pair of auxiliary rollers 26 are rotatably journaled to a lower end portion of the body case 10 . Lower end portions of the timing roller 21 and the auxiliary rollers 26 protrude from the lower end of the body case 10 . As the body case 10 is manually moved in the recording direction while the timing roller 21 is in contact with the recording sheet 11 , the timing roller 21 rotates in a predetermined direction (clockwise in FIG. 2) and, simultaneously, the encoder plate 24 is rotated by the gear 23 , so that the photo-sensor 25 outputs an encoder signal composed of a pulse train (that is, a signal indicating the amount of movement). Based on the encoder signal and recording data, ink is selectively ejected from ejection nozzles at each recording timing at intervals corresponding to a movement of the body case 10 of a predetermined number of recording pitches, thereby recording characters and graphic images on the recording sheet 11 .
A cap member 31 capable of tightly contacting a head surface 2 a of the recording head 2 , and a cap drive mechanism 30 for driving the cap member 31 , will be described with reference to FIGS. 4 and 5 as well. In FIG. 4, the cap member 31 is at a capping position. In FIG. 5, the cap member 31 is at a withdrawn position. The cap member 31 is formed of an elastic rubber, and has a block shape that is slightly larger than the head surface 2 a (lower end surface) of the recording head 2 . The cap member 31 has a transversely long suction recess 31 a corresponding to the ejection nozzle array disposed in the recording head 2 . A wiper blade 32 , extending in the transverse direction and having a predetermined height, is provided integrally with an end portion of the cap member 31 , the end being in the printing direction. The wiper blade 32 is formed of the same elastic rubber as the cap member 31 . The wiper blade 32 has a certain elasticity and is deformable.
A position switching solenoid 33 for driving the cap member 31 is disposed on a lower end portion of the body case 10 . A distal end of a plunger 33 a of the position switching solenoid 33 is connected to the cap member 31 . When recording is not performed, the position switching solenoid 33 remains undriven so that the plunger 33 a is in a projected position. Therefore, the cap member 31 remains in tight contact with the downward-facing head surface 2 a of the recording head 2 , as shown in FIG. 4 . When recording is to be performed, the position switching solenoid 33 is driven so that the plunger 33 a is withdrawn as shown in FIG. 5 . Therefore, the cap member 31 is horizontally moved, sliding on the head surface 2 a, in a direction opposite to the recording direction. The cap member 31 is thus switched to the withdrawn position. While the cap member 31 is being moved to the withdrawn position, the wiper blade 32 thoroughly wipes unnecessary ink from the head surface 2 a, that is, the ejection nozzle surface. When the driving of the position switching solenoid 33 is discontinued, the plunger 33 a is projected or thrust out so that the cap member 31 is moved back to the capping position sliding on the head surface 2 a.
A suction mechanism (a head recovery device) 40 for sucking the ejection nozzles of the recording head 2 will now be described in detail. An end of a suction tube 41 is connected to a side surface of the suction recess 31 a of the cap member 31 . The other end of the suction tube 41 is connected to a suction pump 42 disposed on the body case 10 . The suction pump 42 is designed to produce a negative pressure for suction by using a cam body that is rotated by a small-size motor driven by the battery 8 . Due to the negative pressure, the ejection nozzles are sucked via the suction recess 31 a and the suction tube 41 .
A control system provided in the control portion 7 a for controlling the manually-driven recording apparatus 1 is structured as schematically shown in the block diagram of FIG. 6. A control device 50 includes a microprocessor that has a CPU 51 , a ROM 52 , a RAM 53 and an input/output interface 54 . The control device 50 further includes an optical communication interface 55 , an infrared-receiving circuit 56 and an infrared-transmitting circuit 57 for communication by infrared light with an external electronic device (not shown), such as a personal computer, and further includes drive circuits 58 - 60 , and the like. The input/output interface 54 is connected to the power switch 12 , the print instruction switch 13 , the suction switch 14 , the photo-sensor 25 , a drive circuit 58 for the position switching solenoid 33 , a drive circuit 59 for the suction pump 42 , and a drive circuit 60 for the recording head 2 . The infrared-receiving circuit 56 is connected to the infrared photo-diode 5 , and the infrared-transmitting circuit 57 is connected to the infrared-emitting diode 6 . The infrared-receiving circuit 56 receives optical data transmitted from an external electronic device by infrared, via the infrared photo-diode 5 . The infrared-transmitting circuit 57 transmits, to the external electronic device, recording format data regarding character sizes or fonts and various data regarding data transfer, in the form of optical data, via the infrared-emitting diode 6 .
The ROM 52 stores a recording control program for drive-controlling an actuator provided for each ejection nozzle of the recording head 2 , a control program for optical data transmission and reception, a control program for recording control (described below), dot pattern data regarding individual characters and symbols, and the like. The RAM 53 includes a data memory for storing optical data received, and various memories needed for recording control or optical communication control and the like.
A print control routine executed by the control device 50 of the manually-driven recording apparatus 1 will be described with reference to the flowchart of FIG. 7, in which Si (i=10, 11, 12, . . . ) indicates individual steps. When the power switch 12 of the recording apparatus 1 is turned on, this control routine is started. The control device 50 waits until recording data is received via the infrared photo-diode 5 (No in step S 10 ). If recording data has been received (Yes in step S 10 ), the control device 50 performs data development into dot pattern data (step S 11 ). If recording data composed of a plurality of code data is received, a plurality of code data for recording individual lines are separately developed into dot pattern data. Until the print instruction switch 13 is turned on, the control device 50 remains in a recording standby state (No in step S 12 )
The body case 10 is manually held in a substantially vertical upstanding position so that the timing roller 21 is in contact with the recording sheet 11 . Then, the print instruction switch 13 is turned on for recording (Yes in step S 12 ). The body case 10 is then manually moved linearly in the printing direction while the print instruction switch 13 is held in the on-position. As the encoder plate 24 is rotated by rotation of the timing roller 21 , the encoder signal outputted from the photo-sensor 25 is inputted to the control device 10 (Yes in S 13 ). The position switching solenoid 33 is then driven so that the cap member 31 is moved from the capping position (FIG. 4) to the withdrawn position (FIG. 5 ), sliding on the head surface 2 a (S 15 ). While the cap member 31 is being moved to the withdrawn position, the wiper blade 32 thoroughly wipes unnecessary ink from the head surface 2 a, that is, the ejection nozzle surface. Based on the recording data for one row of dots, the control device 50 performs recording of the dot row (S 16 ), by driving the corresponding ejection nozzles to eject ink. Subsequently, if the print instruction switch 13 is on (Yes in step S 17 ) and the encoder signal is inputted, that is, the manually-driven movement of the body case 10 continues (Yes in step S 18 ), it is then determined in step S 19 whether the recording is completed. If recording is not completed (No in step S 19 ), the operation of steps S 16 -S 19 is repeated to performing recording of one dot row at a time.
When recording of a line is completed (Yes in step S 19 ), the operation of steps S 17 -S 19 is repeated. When the body case 10 is stopped, input of the encoder signal discontinues (No in step S 18 ). If the non-recording state continues for a predetermined length of time (for example, 2 to 3 seconds) (Yes in step S 20 ), the driving of the position switching solenoid 33 is stopped so that the cap member 31 is moved from the withdrawn position to the capping position (FIG. 4 ), sliding on the head surface 2 a (S 21 ). Since the cap member 31 is thus switched between the capping position and the withdrawn position in cooperation with the recording operation so that the cap member 31 is at the capping position when recording is not performed, ink on the head surface 2 a is protected from drying. If recording of a line is completed (Yes in S 19 ) and then the print instruction switch 13 is turned off so that recording inhibition is instructed (No in step S 17 ), it is determined in step S 20 whether the recording inhibited state has continued for a predetermined length of time. If the recording inhibited state has continued for the predetermined length of time (Yes in step 20 ), the cap member 31 is moved to the capping position (S 21 ). If the body case 10 is temporarily stopped during a recording operation, the determination in step S 18 is NO, and the operation proceeds to step S 20 . If the print instruction switch 13 is temporarily turned off, the determination in step S 17 is NO, and the operation proceeds to step S 20 . If it is subsequently determined in step S 20 that the recording inhibited state has not continued for the predetermined length of time, the operation starting at step S 16 is repeated to continue recording.
If it is determined in step S 10 that recording data is not received, the control device 50 checks whether the suction switch 14 is turned on (S 10 - 1 ). If the suction switch 14 is turned on (Yes in step S 10 - 1 ), the control device 50 starts a suction operation by the suction mechanism 40 (S 10 - 2 ). After that, the operation returns to step S 10 .
FIG. 8 illustrates the suction operation subroutine. When this routine is started, it is determined in step S 50 whether the cap member 31 is at the capping position relative to the recording head 2 . If the cap member 31 is at the capping position (Yes in step S 50 ), it is determined in step S 52 whether the print instruction switch 13 has been turned on within a predetermined time, for example, 10 sec., after the suction switch 14 is turned on. If the print instruction switch 13 is on (Yes in step S 52 ), the suction pump 42 is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member 31 in step S 53 . That is, only when both the suction switch 14 and the print instruction switch 13 are on, operation of the suction mechanism 40 is manually instructed, thereby preventing unintentional or accidental suction operation. Thus, the print instruction switch 13 , and the control device 50 constitute an inhibition device for inhibiting operation of the head recovery device under a predetermined condition. The number of such switches may be more than two. The switches are not limited to electrical switches but may be mechanical switches.
The invention is not limited to the foregoing embodiment, but may be modified in various ways. For example, although the embodiment employs two switches as a device for inhibiting operation of the head recovery device and canceling the inhibition, devices other than two switches may be employed as in an embodiment described below.
A second embodiment will be described with reference to FIGS. 7 and 9. Referring first to the flowchart of FIG. 7, when print control is started, it is determined in step S 10 whether recording data is received. If recording data is not received, it is checked in step S 10 - 1 whether the suction switch 14 is on. If it is determined that the suction switch 14 is on (Yes in step S 10 - 1 ), the control device 50 starts suction operation by the suction mechanism 40 in step S 10 - 2 .
A modification of the suction operation subroutine is illustrated in FIG. 9 . It is first determined in step S 60 whether the cap member 31 is at the capping position relative to the recording head 2 . If the cap member 31 is at the capping position (Yes in step S 60 ), it is determined in step S 62 whether the suction switch 14 has been turned on within a predetermined time, for example, 10 sec. If the suction switch 14 is turned on (Yes in step S 62 ), the suction pump 42 is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member 31 in step S 63 . That is, when a single switch (the suction switch 14 in this modification) is continually operated, i.e., double clicked, i.e., turned on a second time for this embodiment the inhibition of operation of the suction mechanism 40 is canceled so that the suction operation is performed. Therefore, an unnecessary suction operation caused by a single misoperation of the suction switch 14 is prevented. Thus the first operation of the suction switch 14 and the control device 50 constitute an inhibition device.
A third embodiment will be described with reference to FIGS. 10 and 11. In the third embodiment, a timer 61 is connected to the CPU 51 of the control device 50 as shown in FIG. 10 . The timer 61 measures the time elapsed from a previous operation of the head recovery device (suction mechanism 40 ). When the time measured by timer 61 reaches a predetermined length of time, the inhibition of operation of the head recovery device (suction mechanism 40 ) is canceled.
Referring to the flowchart of print control of FIG. 11, if recording data is not received (No in step S 10 ), it is determined in step S 10 - 11 whether a predetermined length of time has elapsed following a previous operation of the head recovery device (suction mechanism 40 ) on the basis of the time measured by the timer 61 . The timer 61 is reset in response to an operation of the suction mechanism 40 , and measures the time elapsed from the operation of the suction mechanism 40 . When the predetermined length of time has elapsed following the previous operation of the suction mechanism 40 (Yes in step S 10 ), the control device 50 starts suction operation by the suction mechanism 40 in step S 10 - 2 .
The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG. 9 . It is first determined in step S 60 whether the cap member 31 is at the capping position relative to the recording head 2 . If the cap member 31 is at the capping position (Yes in step S 60 ), it is determined in step S 62 whether the suction switch 14 is turned on. If the suction switch 14 is on (Yes in step S 62 ), the suction pump 42 is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member 31 in step S 63 . That is, only when the predetermined length of time has elapsed following the previous operation of the suction mechanism 40 , the operation of the suction switch 14 becomes valid. The inhibition of operation of the suction mechanism 40 is thereby canceled so that the suction operation is performed. Therefore, the unnecessary performance of a great number of suction operations by the misoperation of the suction switch 14 in a short time is prevented and, therefore, unnecessary ink consumption is prevented. In this embodiment, the timer 61 and the control device 50 constitute the inhibition device.
A fourth embodiment will be described with reference to FIGS. 10 and 12. In the fourth embodiment, the timer 61 is connected to the CPU 51 of the control device 50 . The timer 61 measures the time elapsed from the turning on of the power switch 12 . When the time measured by timer 61 reaches a predetermined length of time, the inhibition of operation of the head recovery device (suction mechanism 40 ) is canceled.
Referring to the flowchart of print control of FIG. 12, if recording data is not received (No in step S 10 ), it is determined in step S 10 - 12 whether a predetermined length of time has elapsed following the turning on of the power switch 12 , on the basis of the time measured by the timer 61 . The timer 61 measures the time elapsed from the turning on of the power switch 12 . When the predetermined length of time has elapsed following the turning on of the power switch 12 (Yes in Step 10 - 12 ), the control device 50 starts suction operation by the suction mechanism 40 in step S 10 - 2 .
The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG. 9 . It is first determined in step S 60 whether the cap member 31 is at the capping position relative to the recording head 2 . If the cap member 31 is at the capping position (Yes in step S 60 ), it is determined in step S 62 whether the suction switch 14 is turned on. If the suction switch 14 is on (Yes in step S 62 ), the suction pump 42 is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member 31 in step S 63 . That is, only when the predetermined length of time has elapsed following the turning on of the power switch 12 , the operation of the suction switch 14 becomes valid. The inhibition of operation of the suction mechanism 40 is thereby canceled so that the suction operation is performed. Therefore, unnecessary performance of a great number of suction operations by misoperation of the suction switch 14 in a short time is prevented and, therefore, unnecessary ink consumption is prevented. The power switch 12 , the timer 61 , and the control device 50 constitute the inhibition device.
A fifth embodiment will be described with reference to FIGS. 13 and 14. In the fifth embodiment, the RAM 53 has, in addition to a data memory 53 A, an amount of printed characters storage area 53 B, a number-of-prints storage area 53 C for storing the number of print operations, and an ink consumption storage area 53 D for storing the amount of ink used, as shown in FIG. 13. A count value of an amount of printed characters after a previous head recovery operation by the suction mechanism 40 is stored in the amount of printed characters storage area 53 B.
Referring to the flowchart of print control according to this embodiment illustrated in FIG. 14, the count value stored in the amount of printed characters storage area 53 B is incremented every print of one character in the one dot row print operation of step S 16 . If recording data is not received (No in step S 10 ), it is determined in step S 10 - 13 whether the amount of print performed after a previous head recovery operation has reached or exceeded a predetermined amount of print, on the basis of the count value stored in the amount of printed characters storage area 53 B. If the value stored in the amount of printed characters storage area 53 B is equal to or greater than the predetermined amount of print (Yes in Step S 10 - 13 ), the control device 50 starts a suction operation by the suction mechanism 40 in step S 10 - 2 .
The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG. 9 . It is first determined in step S 60 whether the cap member 31 is at the capping position relative to the recording head 2 . If the cap member 31 is at the capping position (Yes in step S 60 ), it is determined in step S 62 whether the suction switch 14 is turned on. If the suction switch 14 is on (Yes in step S 62 ), the suction pump 42 is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member 31 in step S 63 . That is, when the amount of print performed after a previous head recovery operation has reached or exceeded the predetermined amount of print, the operation of the suction switch 14 becomes valid. The inhibition of operation of the suction mechanism 40 is thereby canceled so that the suction operation is performed. Therefore, unnecessary performance of a great number of suction operations by misoperation of the suction switch 14 before the amount of print performed after a previous head recovery operation has reached or exceeded the predetermined amount is prevented and, therefore, unnecessary ink consumption is prevented. Thus, the inhibition device is the control device 50 , a counter therein, and its RAM 53 .
A sixth embodiment will be described with reference to FIGS. 13, 15 and 16 . In the sixth embodiment, the input-output interface 54 is further connected to an ink flow sensor 63 for detecting the flow of ink from the ink tank 15 to the recording head 2 , as shown in FIG. 15 . The accumulated count value of ink consumed which is output by the ink flow sensor 63 after a previous head recovery operation of the head recovery device (suction mechanism 40 ) is stored in the ink consumption storage area 53 D of the RAM 53 shown in FIG. 13 .
Referring to the flowchart of print control according to this embodiment illustrated in FIG. 16, if recording data is not received (No in step S 10 ), it is determined in step S 10 - 14 whether the amount of ink consumed after a previous operation of the head recovery device (suction mechanism 40 ) has reached or exceeded a predetermined amount, on the basis of the accumulated value stored in the consumption storage area 53 D. If the value stored in the consumption storage area 53 D is equal to or greater than the predetermined amount of ink consumption (Yes in Step S 10 - 14 ), the control device 50 starts the suction operation by the suction mechanism 40 in step S 10 - 2 .
The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG. 9 . It is first determined in step S 60 whether the cap member 31 is at the capping position relative to the recording head 2 . If the cap member 31 is at the capping position (Yes in step S 60 ), it is determined in step S 62 whether the suction switch 14 is turned on. If the suction switch 14 is on (Yes in step S 62 ), the suction pump 42 is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member 31 in step S 63 . That is, when the amount of ink consumed after a previous head recovery operation has reached or exceeded the predetermined amount, the operation of the suction switch 14 becomes valid. The inhibition of the operation of the suction mechanism 40 is thereby canceled so that the suction operation is performed. Therefore, the unnecessary performance of a great number of suction operations by misoperation of the suction switch 14 before the amount of ink consumed after a previous head recovery operation has reached or exceeded the predetermined amount is prevented and, therefore, unnecessary ink consumption is prevented. Thus, the ink flow sensor and the control device 50 , with its RAM 53 , constitute the inhibition device.
A seventh embodiment will be described with reference to FIGS. 13 and 17. In the seventh embodiment, the number of print operations following a previous operation of the head recovery device (suction mechanism 40 ) is stored in the number-of-prints storage area 53 C of the RAM 53 . The number of print operations herein means the number of times that printing is instructed.
Referring to the flowchart of print control according to this embodiment shown in FIG. 17, every time the print instruction switch 13 is turned on, a number-of-prints counter is incremented in step S 12 - 1 . The incremented count of the number-of-prints counter is stored in the number-of-prints storage area 53 C of the RAM 53 .
If recording data is not received (No in step S 10 ), it is determined in step S 10 - 15 whether the number of print operations following a previous operation of the head recovery device (suction mechanism 40 ) has reached or exceeded a predetermined number, on the basis of the count value stored in the number-of-prints storage area 53 C. If the value stored in the number-of-prints storage area 53 C is equal to or greater than the predetermined number (Yes in Step S 10 - 15 ), the control device 50 starts the suction operation by the suction mechanism 40 in step S 10 - 2 .
The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG. 9 . It is first determined in step S 60 whether the cap member 31 is at the capping position relative to the recording head 2 . If the cap member 31 is at the capping position (Yes in step S 60 ), it is determined in step S 62 whether the suction switch 14 is turned on. If the suction switch 14 is on (Yes in step S 62 ), the suction pump 42 is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member 31 in step S 63 . That is, when the number of print operations following a previous head recovery operation has reached or exceeded the predetermined number, the operation of the suction switch 14 becomes valid. The inhibition of the operation of the suction mechanism 40 is thereby canceled so that the suction operation is performed. Therefore, the unnecessary performance of a great number of suction operations by the misoperation of the suction switch 14 before the number of print operations following a previous head recovery operation has reached or exceeded the predetermined number is prevented and, therefore, unnecessary ink consumption is prevented. Thus, the print switch 13 , the control device 50 , and its RAM 53 , constitute the inhibition device for the embodiment.
An eighth embodiment will be described with reference to FIGS. 13 and 18. The eighth embodiment is a modification of the fifth embodiment. In the eighth embodiment, the count value of amount of printed characters after the power switch 12 has been turned on is stored in the amount of printed characters storage area 53 B.
Referring to the flowchart of print control according to this embodiment illustrated in FIG. 18, the count value stored in the amount of printed characters storage area 53 B corresponding to the amount of printed characters after the power switch 12 has been turned on is incremented every print of one character in the one dot row print operation of step S 16 . If recording data is not received (No in step S 10 ), it is determined in step S 10 - 16 whether the amount of print performed after the turning on of the power switch 12 has reached or exceeded a predetermined amount of print, on the basis of the count value stored in the amount of printed characters storage area 53 B. If the value stored in the amount of printed characters storage area 53 B is equal to or greater than the predetermined amount of print (Yes in Step S 10 - 16 ), the control device 50 starts the suction operation by the suction mechanism 40 in step S 10 - 2 .
The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG. 9 . It is first determined in step S 60 whether the cap member 31 is at the capping position relative to the recording head 2 . If the cap member 31 is at the capping position (Yes in step S 60 ), it is determined in step S 62 whether the suction switch 14 is turned on. If the suction switch 14 is on (Yes in step S 62 ), the suction pump 42 is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member 31 in step S 63 . That is, when the amount of print performed after the turning on of the power switch 12 has reached or exceeded the predetermined amount of print, the operation of the suction switch 14 becomes valid. The inhibition of the operation of the suction mechanism 40 is thereby canceled so that the suction operation is performed. Therefore, the unnecessary performance of a great number of suction operations by misoperation of the suction switch 14 before the amount of print performed after the turning on of the power switch 12 has reached or exceeded the predetermined amount is prevented and, therefore, unnecessary ink consumption is prevented. Thus, the control device 50 and its RAM 53 constitute the inhibition device of the embodiment.
A ninth embodiment will be described with reference to FIGS. 13, 15 and 19 . In the ninth embodiment, the input-output interface 54 is further connected to the remaining ink amount sensor 62 for detecting the amount of ink remaining in the ink tank 15 , and the ink flow sensor 63 for detecting the flow of ink from the ink tank 15 to the recording head 2 , as shown in FIG. 15 . The accumulated count value of ink consumed which is output by the ink flow sensor 63 after the power switch 12 has been turned on is stored in the consumption storage area 53 D of the RAM 53 shown in FIG. 13 .
Referring to the flowchart of print control according to this embodiment illustrated in FIG. 19, if recording data is not received (No in step S 10 ), it is determined in step S 10 - 17 whether the amount of ink consumed after the turning on of the power switch 12 has reached or exceeded a predetermined amount, on the basis of the accumulated value stored in the consumption storage area 53 D. If the value stored in the consumption storage area 53 D is equal to or greater than the predetermined amount of ink consumption (Yes in Step S 10 - 17 ), the control device 50 starts the suction operation by the suction mechanism 40 in step S 10 - 2 .
The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG. 9 . It is first determined in step S 60 whether the cap member 31 is at the capping position relative to the recording head 2 . If the cap member 31 is at the capping position (Yes in step S 60 ), it is determined in step S 62 whether the suction switch 14 is turned on. If the suction switch 14 is on (Yes in step S 62 ), the suction pump 42 is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member 31 in step S 63 . That is, when the amount of ink consumed after the turning on of the power switch 12 has reached or exceeded the predetermined amount, the operation of the suction switch 14 becomes valid. The inhibition of the operation of the suction mechanism 40 is thereby canceled so that the suction operation is performed. Therefore, the unnecessary performance of a great number of suction operations by misoperation of the suction switch 14 before the amount of ink consumed after the turning on of the power switch 12 has reached or exceeded the predetermined amount is prevented and, therefore, unnecessary ink consumption is prevented. The inhibition device is constituted of the remaining ink amount sensor 62 , the ink flow sensor 63 , and the control device 50 with its RAM 53 .
A tenth embodiment will be described with reference to FIGS. 13 and 20. In the tenth embodiment, the number of print operations performed after the power switch 12 has been turned on is stored in the number-of-prints storage area 53 C of the RAM 53 . The number of print operations herein means the number of times that printing is instructed.
Referring to the flowchart of print control according to this embodiment shown in FIG. 20, every time the print instruction switch 13 is turned on, a number-of-prints counter is incremented in step S 12 - 2 . The incremented count of the number-of-prints counter is stored in the number-of-prints storage area 53 C of the RAM 53 . This stored value is reset every time the power switch 12 is turned on, and the value is incremented every time the print instruction switch 13 is turned on.
If recording data is not received (No in step S 10 ), it is determined in step S 10 - 18 whether the number of print operations following the turning on of the power switch 12 has reached or exceeded a predetermined number, on the basis of the count value stored in the number-of-prints storage area 53 C. If the value stored in the number-of-prints storage area 53 C is equal to or greater than the predetermined number (Yes in Step 10 - 18 ), the control device 50 starts suction operation by the suction mechanism 40 in step S 10 - 2 .
The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG. 9 . It is first determined in step S 60 whether the cap member 31 is at the capping position relative to the recording head 2 . If the cap member 31 is at the capping position (Yes in step S 60 ), it is determined in step S 62 whether the suction switch 14 is turned on. If the suction switch 14 is on (Yes in step S 62 ), the suction pump 42 is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member 31 in step S 63 . That is, when the number of print operations following the turning on of the power switch 12 has reached or exceeded the predetermined number, the operation of the suction switch 14 becomes valid. The inhibition of the operation of the suction mechanism 40 is thereby canceled so that the suction operation is performed. Therefore, the unnecessary performance of a great number of suction operations by misoperation of the suction switch 14 before the number of print operations following the turning on of the power switch 12 has reached or exceeded the predetermined number is prevented and, therefore, unnecessary ink consumption is prevented. The control device 50 , and its RAM 53 A, constitute the inhibition device.
An eleventh embodiment will be described with reference to FIGS. 15 and 21. In the eleventh embodiment, the input-output interface 54 of the control device 50 is further connected to the remaining ink amount sensor 62 for detecting the amount of ink remaining in the ink tank 15 . Referring to the flowchart of print control according to this embodiment illustrated in FIG. 21, if recording data is not received (No in step S 10 ), it is determined in step S 10 - 19 whether the amount of ink remaining detected by the remaining ink amount sensor 62 is equal to or less than a predetermined amount. If the remaining ink amount is equal to or less than the predetermined amount (Yes in step S 10 - 19 ), the operation returns to step S 10 , thereby avoiding cancellation of the inhibition of operation of the head recovery device (suction mechanism 40 ). With this structure, when the amount of remaining ink has become small, cancellation of the inhibition of recovery operation is prevented, thereby avoiding an inconvenient incident wherein a small amount of ink left is completely consumed by recovery operation so that printing becomes impossible. Thus, the remaining ink amount sensor 62 and the control device 50 constitute the inhibition device.
A twelfth embodiment will be described with reference to the flowchart of FIG. 22 . The twelfth embodiment employs a second counter for counting the number of operations of the head recovery device (suction mechanism 40 ). When the count of the second counter reaches a predetermined number, cancellation of the inhibition of operation of the head recovery device is prevented.
As illustrated in the flowchart of print control of the twelfth embodiment, when an ink cartridge is replaced, the count of the second counter is cleared to n=0. If recording data is not received (No in step S 10 ), it is determined in step S 10 - 20 whether the value n of the second counter is equal to or less than a predetermined number k. If the counter value n is equal to or less than the predetermined number k (Yes in step S 10 - 21 ), it is determined in step S 10 - 21 whether the suction switch 14 is turned on. If the suction switch 14 is on (Yes in step S 10 - 22 ), the control device 50 performs suction operation in step S 10 - 2 , and increments the value n of the second counter in step S 10 - 3 , and returns to step S 10 . When the value n of the second counter becomes has become greater than the predetermined number k (No in step S 10 - 21 ), the operation returns to step S 10 , thereby avoiding cancellation of the inhibition of operation of the head recovery device. The value n of the second counter is stored in a number-of-recoveries storage area 53 E of the RAM 53 shown in FIG. 13 .
In the twelfth embodiment, the number of operations of the head recovery device (suction mechanism 40 ) is counted, and recovery operation is prevented if the count exceeds the predetermined number. Therefore, unnecessary performance of a great number of recovery operations by misoperation of the suction switch 14 is prevented and, therefore, unnecessary ink consumption is prevented. Thus, the control device 50 and its RAM 53 constitute the inhibition device. In all embodiments, the control device 50 can be considered the inhibition override mechanism as it checks for a condition precedent before allowing an activated manual switch commanding recovery to be executed.
A slide switch 80 may be provided for selecting whether to set a condition for inhibition by an inhibiting device, as in a modification shown in FIG. 23, thereby enabling selection of whether to set a condition for inhibition by the inhibiting device. Furthermore, it is also possible to provide a device for setting a plurality of conditions for inhibition or to allow the head recovery device to be driven without any inhibition conditions for the inhibiting device.
Furthermore, it is possible to provide a reset switch 81 as shown in FIG. 24 . If the head recovery operation is really needed under a condition for inhibition by the inhibiting device, a recovery operation is allowed by pressing the reset switch 81 . The reset switch may be designed so that the reset switch is not easily pressed by a finger during normal operation. For example, the reset switch may be disposed inside a small recess so that the reset switch is pressed only by a pen tip or the like. Such a reset device is not limited to the reset switch, but may be a device that cancels the inhibition condition upon receiving a permitting instruction from an external device.
The above-described embodiments are for small-size portable recording apparatuses, such as manually-driven printing apparatus, and particularly useful for apparatuses equipped with small-capacity ink tanks.
It is to be understood that the invention is not restricted to the particular forms shown in the foregoing embodiments. Various modifications and alterations can be made thereto without departing from the scope of the invention encompassed by the appended claims. | An ink jet recording apparatus has a recording head for recording by ejecting ink onto a recording medium, a head recovery device that recovers a function of the recording head, a suction switch for operating the head recovery device, and a print instruction switch, and an inhibition device that inhibits operation of the head recovery device under a predetermined condition. When operation of the head recovery device is inhibited under a certain condition, the head recovery device cannot be operated if the suction switch is operated. The inhibition of head recovery operation is canceled when the suction switch and a print instruction switch are operated. The recording apparatus thereby prevents unintentional head recovery operation and prevents unnecessary ink consumption, without degrading the operability of the head recovery device. | 1 |
BACKGROUND
1. Field of the Invention
The invention relates to a method for influencing a shift process connected with a change in transmission ratio when driving a motor vehicle.
2. Description of Related Art
It is known to control automatic transmissions so that up-shifting into a higher gear is prevented when traveling around a curve. The purpose is that a driver who, for example, lets upon on the accelerator immediately before a curve or in a curve and depresses the accelerator again after leaving the curve will have the same amount of torque available after the curve as when entering the curve. It is thus intended that a driver who for example lets up on the accelerator immediately before a curve or in a curve, after travelling past the curve when pushing down on the accelerator again has the same power and performance as when driving into the curve. During normal shift programs, letting up on the accelerator would lead to the transmission shifting into a higher gear and on leaving the curve there would be insufficient acceleration power or the transmissions would only shift back to a lower bear before renewed acceleration.
It is known from DE 196 18 804 to develop a method where shifts are suppressed in curves to the extent that in addition the type of driver is determined and the type of shift suppression is influenced.
In many cases, for example when travelling around very long curves or in the case of vehicles with manual shift transmissions it is neither desirable nor possible to fully suppress gear changes when travelling around curves. In these cases it is however desirable in order to let the shifting process take place in a manner that is adapted to the momentary conditions of a curved course of travel.
Accordingly the invention is concerned with the problem of providing a method for influencing a shift process connected to a change in transmission ratio when driving a motor vehicle which also leads when driving round curves to comfortable shifting which does not impair driving safety.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method for influencing a shift process connected to a change in transmission ratio when driving a motor vehicle that results in comfortable shifting when driving around curves and does not impair driving performance or safety.
It is a further object of the present invention to provide an apparatus capable of performing the above described process.
The present invention influences the shift process that occurs during a change in transmission ratio when a motor vehicle follows a curved path, such as a curve in the road. This allows the driving character of the vehicle during the shift process to be altered as desired, such as the performance of the vehicle or maintaining adequate safety and control over the vehicle.
Preliminarily, the state of the vehicle in a curved path must be detected. This may be accomplished by detecting one or more characteristics of the vehicle that indicate the vehicle is driving in a curved path. Various characteristics, by way of example, may include the transverse force exerted on the drive wheels of the vehicle, the transverse acceleration of the vehicle, the steering angle, difference in speed between wheels on an axle, operating condition of vehicle systems, and the navigational position of the car. In addition, the measured characteristics may be compared against predetermined values or using algorithms to determine amount of actual or desired curvature of the vehicle path.
Once it is detected that the vehicle is traveling on a curved path, which may include the degree, the shift process during a transmission ratio change may be influenced in a predetermined way. The result of this influence may be, for example, to decrease the longitudinal forces that act on the driven wheels, increasing comfort, safety or performance. Ways to influence the shift process may include, by way of example, altering the rate of ratio change or clutch engagement, or modifying the activation of various running modes.
According to the present invention, an apparatus is provided for accomplishing the processes of the invention. The apparatus can include a detector for detecting whether the vehicle is traveling around a curve, and a transmission ratio shifter that is responsive to the detector and influences the shift process. The detector may be capable of detecting one or more characteristics of the vehicle that indicate that the vehicle is driving in a curved path. Examples of such detectors may include sensors to detect forces exerted on the driven wheels, vehicle acceleration, wheel speeds, steering angle, vehicle system operating parameters and navigational position of the car. The apparatus may also evaluate the vehicle characteristics, to which the transmission ratio shifter may respond in predetermined ways. The transmission ratio shifter, for example, may alter the rate of ratio change or clutch engagement, or modify the activation of various running modes.
BRIEF DESCRIPTION OF THE DRAWINGS
Other than objects and features of the present invention will be described hereinafter in detail by way of certain preferred embodiments with reference to the accompanying drawings in which:
FIG. 1 is a schematic plan view of a motor vehicle in which a method according to an embodiment of the present invention may be utilized;
FIG. 2 s a schematic flow chart of a method according to an embodiment of the present invention;
FIG. 3 is a schematic chart of a method according to an embodiment of the present invention;
FIG. 4 is a diagrammatic illustration of an apparatus according to an embodiment of the present invention; and
FIG. 5 is a diagrammatic illustration of an apparatus according to an embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
According to FIG. 1 a motor vehicle has an engine 2 connected to a gearbox 6 . A drive shaft 8 leads from the gearbox 6 through a differential 10 to the rear wheels 12 .
In the illustrated embodiment the gearbox 6 is a manual shift transmission which can be operated by a gear shift lever 14 . The clutch 4 is automated and is operated by a control device 16 to which in known way for example the throttle valve position or the position of an accelerator pedal 18 and through a gearbox sensor 20 the position of a shift member in the gearbox and a shift intent are supplied as input signals.
The construction and method of functioning of the units described up until now are known per se and are used in vehicles having automated clutches where the shift lever 14 is indeed still activated by hand but where the clutch pedal is omitted because the clutch 4 is operated automatically.
According to the basic laws of physics only a limited force can be transmitted between a road and a wheel without the traction friction changing into sliding friction which is dangerous for driving safety. Accordingly the force which can be transmitted in the longitudinal direction of the vehicle is greater the smaller the force which is to be transmitted in the transverse direction of the vehicle. When shifting gears in certain circumstances on engagement of the clutch, when the engine is suddenly braked when changing into a higher gear or is suddenly accelerated when changing into a lower gear, the result is forces which are too high acting in the longitudinal direction of the vehicle and which reach the limit of the forces which can be transmitted. When the vehicle is additionally travelling round a curve and lateral forces have to be transmitted by the driven wheels, during clutch engagement the entire force which can be safely transmitted can be exceeded so that the vehicle breaks away or skids which is extremely negative regarding driving safety.
According to the invention the vehicle described up until now maybe provided with a facility which makes it possible to detect when the vehicle is travelling around a curve and to control the operation of the clutch accordingly. To this end different sensors are provided individually or in combination and which can detect the state of travelling around a curve. By way of example wheel sensors 24 are provided on the non-driven front wheels 22 to determine the wheel speeds and these wheel sensors can supply at the same time signals for an anti-locking braking system. Furthermore a steering angle sensor 26 can be provided which detects the position of a track rod 28 connected to the front wheels 22 , and thus the steering angle. Furthermore or in addition a servo sensor 30 can be provided with which the operation of a servo system assisting steering is detected. In addition a transverse acceleration sensor 32 can be provided.
The sensors present in the vehicle are connected to the control device 16 in which algorithms are stored in the program memory to calculate from the determined input signals a value which describes the relevant state of travelling around a curve at that time.
There are various evaluating algorithms which can be used to determine a characteristic value for travelling around a curve.
By way of example the steering angle can be detected by means of the steering angle sensor 26 and exceeding a certain steering angle can be used alone as a characteristic of travelling around a curve.
Alternatively the steering angle can be detected and together with the vehicle speed and the fixed vehicle geometry a transverse acceleration can be calculated.
Alternatively the energy input of a servo pump or an electric servo motor can be detected by the servo sensor 30 and used as a characteristic for travelling around a curve.
If only the wheel sensors are present then the steering angle can be concluded from the differential speed of the wheels of one axle. The mean value of the wheel speeds is a measure of the vehicle speed so that the transverse acceleration can be calculated.
Again as an alternative or in addition the transverse acceleration can be used as a characteristic for the travel around a curve, the state of travelling around a curve being detected by the transverse acceleration sensor 32 .
FIG. 2 shows a flow chart for explaining one example of implementing the invention.
It is assumed that at stage 40 a new gear has been engaged by the gearshift lever 14 . Prior to stage 40 the clutch 4 was opened by controlling the control device 16 so that at stage 40 the driven wheels are free of forward drive or, if the vehicle brake is not activated, are free of deceleration forces.
As a new gear is engaged, which is detected by the gearbox sensor 20 , the signal of for example the steering angle sensor 26 is evaluated in the control device 16 in stage 42 so that in stage 44 it can be established whether the vehicle is or is not travelling around a curve. If no state of travelling around a curve is diagnosed then in stage 46 the clutch 4 is engaged according to the usual engagement process, this engagement process being optimized with regard to rapid shift, gear change comfort and energy consumption for shifting.
If in stage 44 it is established that the vehicle is travelling around a curve, then in the control device 16 a program is activated for a slow engagement which becomes active in stage 48 in order to close the clutch 4 after shifting into the new gear. This slower engagement, when changing into a lower gear, takes place by engaging the engine and through the enforced increases in revs or, when changing into a higher gear, by reductions in revs. Thus, no sudden high forces in the longitudinal direction of the vehicle appear at the driven rear wheels 12 which could lead to the lateral forces which can be transmitted being exceeded and the vehicle skidding.
It is evident that the method described can be modified and refined in many respects. By way of example the engagement program which is activated when the state of travelling around a curve is determined can be slowed down proportional to the transverse acceleration determined.
In a more expensive embodiment, the longitudinal forces transmitted by the driven rear wheels 12 to the road can be determined for example by means of an acceleration sensor active in the longitudinal direction of the vehicle and the engagement process can be controlled so that the sum of the longitudinal forces and transverse forces does not exceed a certain amount.
The invention can be used not only for automated clutches used in conjunction with manual shift transmissions. It can likewise be used when the shift transmission 6 is automated for example with gear changes proceeding according to predetermined programs. It is possible depending on the relevant program also to change gear within a curve and in this case the algorithms stored in the control device 16 ensure that the engagement of the clutch 4 takes place so smoothly after a gear change that there is no danger of the vehicle skidding sideways.
Both in the case of automated shift transmissions and manual shift transmissions the control device 16 can, in addition to adapting the operation of the clutch to travelling around a curve, also control the engine itself for a limited period of time so that inadmissible accelerations or brakings are suppressed. A throttle valve or other power adjustment member of the engine is then not activated directly by the accelerator pedal 18 but instead the accelerator pedal 18 operates through a servo motor through a control device for adjusting a power adjustment member of the engine.
The gearbox 6 can also be a CVT gearbox, the operation of which is controlled when travelling around a curve so that predetermined acceleration and deceleration forces at the wheel surfaces are not exceeded. When driving in a straight line, the CVT gearbox changes for example its transmission ratio very rapidly according to requirements (when pressing down the accelerator, for example for overtaking, it switches very rapidly to a shorter (lower) transmission ratio or when letting up the accelerator switches to a longer (higher) transmission ratio). In contrast this change in transmission ratio takes place correspondingly more slowly when travelling around a curve.
The clutch 4 can in a modified embodiment also be a torque converter with integrated lock-up clutch. The converter characteristic and/or actuation of the lock-up clutch can be handled by the control device 16 in dependence on the curve.
In an alternative embodiment of the invention, see FIG. 3, if an emergency operation program has to be activated, and this takes place when travelling around a curve, this emergency operation program is activated with delay so that again high circumferential forces or longitudinal forces acting at the drive wheels are avoided. When changing over a control strategy program from a normal operating mode of the vehicle to a replacement strategy or emergency operation program relatively large gradients of the circumferential forces from the tires or axles of a vehicle can appear. This can be disadvantageous when changing over into an emergency operation program. Therefore it can also be advantageous if when changing into an emergency running operation the steering angle or the relevant angle included between the wheel and the longitudinal axis of the vehicle is detected and the change-over is delayed or even prevented when the state of travelling around a curve is detected.
FIG. 3 shows in block 100 the call-up of the control strategy according to the invention which undertakes in block 102 an evaluation of the steering angle, for example by means of a steering angle sensor. If the steering angle is within a predeterminable area outside of a central position, then in block 104 it concludes the state of travelling around a curve. If this is the case, then in block 108 the activation of an emergency running operation is delayed or prevented for a predeterminable amount of time. This prevention exists until following the inquiry in block 104 , the state of travelling around a curve no longer exists and the emergency running operation is activated in block 106 . With a delay in activating the emergency running operation, at the end of the waiting time the program is switched into emergency mode even if the state of travelling around a curve still exists. At block 110 the routine is first terminated and recalled again in the next control cycle at 100 . p In order to make an evaluation of the steering angle signal it is preferable to use for example the direct evaluation of a sensor signal of the steering angle sensor which on exceeding a predeterminable threshold value is a clear indication of the state of travelling around a curve. The threshold value can vary for example with the vehicle speed and/or the throttle valve angle and/or the gear engaged in the gearbox. Likewise filtering of the steering angle signal can take place so that a temporary change in the steering angle signal does not lead to drastic effects. Furthermore it is possible by means of a computer program to calculate from the steering angle signal and where applicable other signals, such as for example wheel speeds, the angular speed of the vehicle about its vertical axis (yaw rate). From reaching a predeterminable variable threshold value of the yaw rate the state of travelling around a curve can be concluded.
In a method for influencing a shift process connected with a change in transmission ratio when driving a motor vehicle, the state of travelling around a curve is detected and the shift process occurring while travelling around a curve is influenced so that the longitudinal forces which are active at the driven wheels as a result of a down shift.
FIG. 4 shows a vehicle 201 with a drive unit 202 , such as an internal combustion engine or hybrid drive assembly with an internal combustion engine and with an electric motor, a torque transfer system, such as a clutch 203 and a gearbox 204 wherein on the output side of the gearbox is a drive shaft 205 which drives by means of a differential 206 two drive shafts 207 a and 207 b which in turn drive the driven wheels 208 a and 208 b. The torque transfer system 203 is shown as a friction clutch with a flywheel 209 , a pressure plate 210 , a clutch disc 211 , a release bearing 212 and a disengagement fork 213 . The disengagement fork is biased by means of an actuator 215 through a master cylinder 216 , a pressurised medium line, such as a hydraulic line 217 , and a slave cylinder 218 . The actuator is shown as an actuator operated by pressurised medium which has an electric motor 219 which operates a master cylinder piston 220 through a gearbox. The torque transfer system can be engaged and disengaged through the pressurised medium line 217 and the slave cylinder 218 . Furthermore the actuator 215 includes the electronics for its operation and control, that is both the power electronics and control electronics. The actuator is provided with a valve 221 , e.g., a closeable opening for fluid exchange of a hydraulic system which is connected to a reservoir 222 for the pressurised medium.
The vehicle 201 with the gearbox 204 has a gear shift lever 230 on which is mounted a gear detection sensor 231 and a shift intent sensor 232 which detects a shift intent of the driver from the movement of the gearshift lever or from the applied force. Furthermore the vehicle is fitted with a speed sensor 233 which detects the speed of the gear output shaft and the wheel speeds respectively. Furthermore a throttle valve position sensor 234 is mounted which detects the throttle valve position and a rotation sensor 235 which detects the engine speed.
The gear detection sensor detects the position of shift elements inside the gearbox or the gear engaged in the gearbox so that at least the engaged gear is registered by the control unit by means of a signal from the sensor. Furthermore with an analog sensor the movement of the shift elements inside the gearbox can be detected so that it is possible to make an early detection of the next gear to be engaged.
The actuator 215 is powered from a battery 240 . Furthermore the vehicle has an (preferable multi-stage) ignition switch 241 which is operated preferable by means of an ignition key whereby the starter of the combustion engine 202 is operated through the lead 242 . A signal is forwarded through the lead 243 to the electronics unit of the actuator 215 after which the actuator is activated for example on operating the ignition.
FIG. 5 shows a diagrammatic view of a drive train of a motor vehicle with a drive unit 601 , such as an internal combustion engine or motor, a torque transfer system 602 , such as for example a friction clutch, a dry friction clutch or a wet-running friction clutch, a gearbox 603 as well as a differential 604 , output shafts 605 and wheels 606 driven by the output shafts. Speed sensors (not shown) can be mounted on the wheels to detect the speeds of the wheels. The speed sensors can also belong functionally to other electronics units, such as for example an anti-lock braking system (ABS). The drive unit 601 can also be a hybrid drive with for example an electric motor, a flywheel with freewheel and an internal combustion engine.
The torque transfer system 602 is formed as a friction clutch but can also be designed for example as a magnetic powder clutch, multi-plate clutch or torque converter with converter lock-up clutch or another type of clutch. Furthermore a control unit 607 is shown as well as an actuator 608 (shown diagrammatically). The friction clutch can also be formed as a self-adjusting clutch adjusting to wear.
The torque transfer system 602 is mounted on a flywheel 602 a or is connected to the flywheel which can be a divided flywheel with a primary mass and a secondary mass, and with a damping device between the primary mass and secondary mass on which a starting gear ring 602 b is mounted. The torque transfer system has overall a clutch disc 602 c with friction linings and a pressure plate 602 d as well as a clutch cover 602 e and a plate spring 602 f. The clutch is preferably self-adjusting and has in addition means which allow displacement and wear adjustment. A sensor, such as a force or displacement sensor is provided which detects a situation in which an adjustment is necessary and in the event of detection the adjustment is carried out.
The torque transfer system is operated by means of a release member 609 such as for example a pressurised medium operated, such as hydraulic, central release member which can support a release bearing 610 . The clutch can be engaged and disengaged by application of a force. The release member can however also be formed as a mechanical release member which operates, biases or governs a release bearing or comparable element.
The actuator 608 controls via a mechanical connection or a pressurised medium line 611 or a transfer section, such as a hydraulic pipe, the mechanical or hydraulic release member or central release member 609 for engaging or releasing the clutch. The actuator 608 furthermore operates with one or several output elements the gearbox for shifting gear. For example a central selector shaft of the gearbox is operated by the output element or the output elements. The actuator thus operates shift elements inside the gearbox to engage, release or change gear stages or transmission ratio stages, such as a central selector shaft or shift rods or other shift elements.
The actuator 608 can also be formed or provided as a shift control cylinder which is mounted inside the gearbox. By being rotated about its own axis, the shift control cylinder moves elements that are guided by guides, e.g., shifter elements, and thereby performs the shift between gear stages. Furthermore the actuator for shifting the gear stages can also contain the actuator for operating the torque transfer system. In this case an active connection with the clutch release member is required.
The control unit 607 is connected through the signal connection 612 to the actuator so that control signals and/or sensor signals or operating state signals can be exchanged, forwarded or retrieved. Furthermore signal connection 613 and 614 are provided through which the control unit is in signal connection at least at times with further sensors or electronics units. Other electronics units of this kind can be for example the engine electronics, anti-lock braking system electronics or anti-slip regulating electronics. Further sensors can be sensors which generally characterise or detect the operating state of the vehicle, such as for example rotation speed sensors of the engine or of the wheels, throttle valve position sensors, accelerator pedal position sensors or other sensors. The signal connection 615 produces a connection to a data bus such as for example a CAN bus through which system data of the vehicle or other electronics can be made available since the electronics units are as a rule cross-linked with each other through computer units.
An automated gearbox can be shifted or a gear change can be performed in a driver-initiated mode where the driver, for example, by means of a selector switch, introduces a signal to shift up or down. Furthermore a signal can also be provided by means of an electronic shift lever to indicate into which gear the gearbox is to be shifted. An automated gearbox can however also carry out a gear change independently by means of for example characteristic values, characteristic lines or characteristic fields and on the basis of sensor signals at certain predetermined points, without the driver having to initiate a gear change.
The vehicle is preferably fitted with an electronic accelerator pedal 623 (or load lever). The accelerator pedal 623 governs a sensor 624 by means of which the engine electronics 620 control or regulate for example the fuel supply, ignition timing, injection time or throttle valve position through the signal lead 621 of the engine 601 . The electronic accelerator pedal 623 with sensor 624 is in signal connection with the engine electronics 620 through the signal lead 625 . The engine electronics 620 is in signal connection with the control unit 607 through the signal lead 622 . Furthermore gear control electronics 630 can also be in signal connection with the units 607 and 620 . An electromotorized throttle valve control is practical for this with the position of the throttle valve being governed by the engine electronics. With systems of this kind a direct mechanical connection with the accelerator pedal is no longer necessary or practical.
The typical friction losses of gearbox components and/or input speeds and/or output speeds of the gearbox can be used in order to determine or calculate for example a gearbox temperature, such as for example gearbox fluid temperature or a temperature of a gearbox element. Furthermore the amounts of fluid and fluid flows can be taken into account. The gearbox temperature designation need not however be restricted to the overrun time, but can also be carried out in other operating situations.
The current supply of the control unit of an automated gearbox and/or an automated torque transfer system can be maintained for example in order to implement specific operating functions according to one operating mode of the vehicle, such as for example if when determining temperature or calculating temperature for example by means of temperature models a critical state is detected, such as for example of the clutch, gearbox or synchronizing device or if for example adaptations are active or data are detected or stored such as for example a store of data or adapted values in an EEPROM. Further adaptations of system values of an electric motor, gearbox or of a pressurised medium system, such as hydraulic system can be carried out. Likewise adjustments in the gearbox or on the clutch (for example when the vehicle stopping device is operated) can be demanded or be required to determine friction forces (sliding and adhesive friction forces or friction values) and characteristic values of the actuator (e.g. engine constant, e.g. armature resistance or time constants in the case of the electric motor). Furthermore hydraulic values or other values, such as characteristic lines of valves or other values can be adjusted.
While the present invention has been particularly shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
The invention is also not restricted to the embodiments of the description. Rather numerous amendments and modifications are possible within the scope of the invention, particularly those variations, elements and combinations and/or materials which are inventive for example through combination or modification of individual features or elements or process steps contained in the drawings and described in connection with the general description and embodiments and claims and which through combinable features lead, to a new subject or to new process steps or sequence of process steps insofar as these refer to manufacturing, test and work processes. | A method for influencing a shift process connected with a change in transmission ratio when driving a motor vehicle that has a set of driven wheels subject to longitudinal and transverse forces, the method including detecting whether or not the vehicle is traveling around a curve and, if doing so when the shift process is in progress, influencing the shift process so as to decrease the longitudinal forces that act on the driven wheels as a result of the shift process. Also disclosed is an apparatus for performing the disclosed method including a detector for detecting whether or not the vehicle is traveling around a curve and a transmission ratio shifter responsive to the detector that, if the vehicle is traveling around a curve when the shift process is in progress, performs the shift process so as to decrease the longitudinal forces that act on the driven wheels as a result of the shift process. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to industrial heat recuperators, and more particularly relates to a heat recuperative apparatus employing a composite ceramic cross-flow heat recuperator for use on furnaces, calciners, ovens and preheaters.
Recent concern about energy conservation and rising fuel costs has caused renewed interest in industrial recuperators to recover waste heat losses and to preheat incoming combustion air to increase the efficiency of furnaces, calciners, ovens and preheaters.
While such recuperators are usually constructed from metal parts, the ceramic recuperator has several advantages over conventional metallic recuperators. For example, ceramics in general have high corrosion resistance, high mechanical strength at elevated temperatures, low thermal expansion coefficients (TEC'S) and good thermal shock resistance, and thus exhibits excellent endurance under thermal cycling; are light in weight (about 1/3 the weight of stainless steel); and are cost competitive with high temperature alloys.
Furthermore, ceramic recuperators are available in a variety of shapes, sizes, hydraulic diameters, (hydraulic diameter is a measure of cross-sectional area divided by wetted perimeters) and compositions. Because their TEC'S are typically lower than those of most metals and alloys, however, ceramic recuperators present a compatibility problem to the design engineer desiring to incorporate them into existing furnace, calciner, oven and preheater structures.
In co-pending U.S. patent application Ser. No. 686,040, filed May 13, 1976, and assigned to the present assignee, there is described a cross-flow ceramic recuperator employing a single ceramic composition. The relatively high cell density of the disclosed structures (for example, 125 cells per square inch) enabled use of such recuperators in forced draft applications, permitting relatively small hydraulic diameters. Where larger hydraulic diameters and/or larger size recuperators are desired (for example, in natural draft applications where back pressures on the order of 0.1 inch of water are desired), fabrication problems are encountered. For example, consideration has been given to assembling large recuperator structures by building them up from blocks or sections of smaller size. However, an attendant problem has been leakage of the heat transfer fluids between subsections or component parts, resulting in the decreased overall efficiency of the recuperative apparatus.
SUMMARY OF THE INVENTION
In accordance with the invention, a composite ceramic cross-flow recuperator composed of a plurality of sectioned ribbed layers sealed together, is incorporated into a metallic housing adapted for coupling to the metallic fittings of existing furnaces, calciners, ovens and preheaters. Sealing means between the layer sections prevents leakage of heat transfer fluids such as exhaust flue gases and incoming combustion air, and thus minimizes heat loss, between core layers.
In accordance with a preferred embodiment, the sealing means comprises an effectively fluid-impervious ceramic cement of a lower melting material than that of the layer material, which cement is plastic at the firing temperature used to sinter the ceramic recuperator structure.
In accordance with another preferred embodiment, the seal is achieved by use of the ceramic cement between the layer sections and adjacent reinforcing members of a material similar to that of the layer material, the reinforcing members positioned adjacent the outer ribs of abutting layer sections.
In accordance with yet another preferred embodiment, a coating of the ceramic cement is located on continuous bond lines of the external surfaces of the ceramic cellular structure assembly to seal alternate sectioned layers from one another.
The recuperative apparatus is useful to preheat incoming heating or combustion air and/or fuel and thus increase the efficiency of existing furnaces, calciners, ovens and preheaters of varying types and sizes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of one embodiment of a recuperative ceramic cellular structure of stacked ribbed bi-sectional layers;
FIG. 2 is a front elevation view of a portion of one bi-sectioned ribbed layer showing abutting sections having the outer ribs between an inverted U-shaped channel as one embodiment of means for sealing the sections together;
FIG. 3 is a front elevation view similar to that of FIG. 2, showing another embodiment of means for sealing the layer sections;
FIG. 4 is a front elevation view, showing yet another embodiment of a means for sealing the layer sections;
FIG. 5 is a perspective view, cut away, of a portion of the outer surface of the stacked structure of FIG. 1 showing a coating of cement on the continuous bond lines between alternate layers;
FIG. 6 is a front elevation view, in section, of one embodiment of a heat recuperative apparatus of the invention, wherein the recuperator of a composite ceramic structure of stacked ribbed bi-sectioned layers is held within a metallic housing;
FIG. 7 is a schematic diagram of a heat recuperative system employing two recuperative apparati of the invention on a two-burner horizontal radiant tube furnace.
DETAILED DESCRIPTION OF THE INVENTION
For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims in connection with the above-identified drawings.
Referring now to FIG. 1 of the drawings, there is shown one embodiment of the composite ceramic recuperator structure 10 of the invention. This ceramic structure is made up of a plurality of stacked ribbed bi-sectioned layers, 11 and 13, positioned so that the ribs of layers 11 and 13 are transverse to one another. The ribbed sections 11, 11a, 13 and 13a may be formed by casting, molding, extruding, tape casting and embossing, or other suitable ceramic forming technique. These ribbed sections, referred to as being in the unfired or "green" state, are then sealed together in the following manner. Channel-shaped members 12 and 12' of a material similar to that of the ribbed sections, which may have been formed by a similar or dissimilar ceramic forming technique, and of a length dimension substantially identical to the length dimension of the ribbed sections, are filled with a ceramic cement 15. The ceramic cement 15 is preferably of a material having a lower melting point than that of the section and channel materials so that at the firing temperatures encountered at a later stage in processing, the cement will assume a plastic state, flowing into irregularities in the bonding surfaces of the ribs and channel and thereby achieving an adequate seal between the sections. The channel is filled with the cement and fitted over the outer ribs of abutting sections. FIG. 2 shows the seal structure in more detail. It will be noted from FIG. 2 that the outer ribs 11' and 11a' are of a height lower than that of the remaining ribs in order that the top surface of the channel 12, when positioned in place will contact the lower surface of the base portion of the next sectioned layer. The process of assembling the bi-sectioned layers is repeated and the resulting layers are stacked so that the ribs of alternate layers are transverse to one another. In a preferred embodiment, the ribbed sections have length dimensions approximately twice that of their width dimensions so that the resulting stacked structure has a square cross-section and may be built up to an approximate cubic configuration. The stacked layers are then fired in the conventional manner (within the sintering range but below the melting temperature of the materials) to convert the green ceramic materials into a polycrystalline ceramic body. During firing, the stacked layers bond together by sintering at points or areas of contact, resulting in a unitary structure having mechnical strength. Nevertheless, deviations from planarity of the stacked green layers result in incomplete sintering together of these layers, leaving voids or cracks along the contact or bonding surfaces. Such voids or cracks may be evident at the visible edges or "bond lines" of the bonding surface between the outermost rib of one layer and the flat surface of the base portion of an adjacent layer. In accordance with a preferred embodiment, these bond lines are covered with layers or coatings 46 of the ceramic cement prior to firing, as shown in FIG. 5. Alternate stacked ribbed layers 41 and 43 form the cross-flow paths for the heat transfer fluids.
In FIG. 3 is shown another embodiment of a sealing means for the layer sections, in which a I-beam shaped member 22 is located on shelf portions 21' and 21a' of the abutting layers 21 and 21a extending beyond the outermost ribs of the abutting layers. Cement 15 surrounds the I-beam shaped member and is also located in a space between the abutting shelf portions 21' and 21a'. It will be noted that the outermost ribs in this embodiment are of the same height as the other ribs of the sections. FIG. 4 shows yet another embodiment of a sealing arrangement in which a more massive beam member 32 is used. This member 32 has dimensions such that its top surface may contact the lower surface of the base portion of the next layer, which may be desired for added support, for example, where thin walled structures are employed.
Other details of the cross-sectional configurations of the stacked recuperator structure will be dependent upon the particular application envisioned, including such considerations as furnace type and design, furnace operating conditions, recuperator size required, etc. In general, however, for natural draft conditions, the hydraulic diameter will fall within the range of approximately 0.5 to 1.50 inches, the cell wall thicknesses will range from about 0.025 inches to about 0.10 inches, and the aspect ratio (the ratio of the height to the width of the cells) will fall within the range of about 0.1 to 1.
It will of course be appreciated by those skilled in the art that in order to maximize the efficiency of heat transfer, the heat transfer surface should be maximized. This may be achieved by both narrowing the width and reducing the number of the supporting ribs, both of which adjustments would result in a reduced aspect ratio, that is, increased width of the cells verses height of the cells. Attendant mechanical weakening of the structure could be at least partially overcome by reducing the height of the cells, further reducing the aspect ratio. However, the undesirable condition of excessive back pressure limits the ability to maximize the heat transfer surface in which manner. Accordingly, the aspect ratio should be maintained within the range of about 0.1 to 1, below which excessive back pressures would be encountered and above which the effective heat transfer surface would be undesirably reduced.
Exemplary materials and conditions for forming a cellular recuperative structure suitable for use in a heat recuperative system will now be presented. Such materials and conditions are in no way limiting or necessary to the successful practice of the invention, but are merely presented to aid the practitioner in the production of a preferred embodiment of the invention.
A ceramic composition having the raw materials in the proportions shown in Table I was formed and extruded through a die to form ribbed layers and channel members for later sealing and stacking into a recuperative structure.
TABLE I______________________________________RAW MATERIAL WEIGHT PERCENT______________________________________Talc (S. #200) 38.40Talc (W. #6) 18.33Tenn. Ball Clay 14.23Alumina 23.53Extruding aids 5.51______________________________________
Typical approximate compositions of the raw materials in weight percent is shown in Table II.
TABLE II__________________________________________________________________________TYPICAL APPROXIMATE COMPOSITION(IN WT. PERCENT) OF RAW MATERIALS TALC (S.#200) TALC (W. #6) TENN. BALL CLAY ALUMINA__________________________________________________________________________Si.sub.O 2 61.0 73.84 58.13 0.08MgO 32.0 0.02 0.30 --Al.sub.2 O.sub.3 0.5 20.15 27.16 99.7Fe.sub.2 O.sub.3 0.5 0.07 1.18 0.30TiO.sub.2 0.03 0.15 1.93 --CaO 0.2 0.06 0.05 --Na.sub.2 0 -- 0.20 0.18 0.06K.sub.2 O -- 1.54 0.57 --Ignition Loss 5.3 4.00 10.51 --H.sub.2 O 5.0 -- -- --__________________________________________________________________________
The combined weight percents on an oxide basis of the compositions is shown in Table III.
TABLE III______________________________________OXIDE WEIGHT PERCENT______________________________________Si.sub.0 2 50.23MgO 13.69Al.sub.2 O.sub.3 34.64Fe.sub.2 O.sub.3 0.49TiO.sub.2 0.35CaO 0.11Na.sub.2 O 0.09K.sub.2 O 0.40______________________________________
The composition shown in Table III melts at approximately 1430° C. and fires at approximately 1400° C. The extruded porosity of the "green" ribbed layers and channel members was measured by a mercury porosimeter technique as approximately 20 percent. The interconnected porosity (that which forms a continuous channel or void from one surface to another of the extruded material) was found to be effectively undetectable to air using a conventional soap solution test. The channel members were then filled with a ceramic cement formed from raw materials in the amounts shown in Table IV.
TABLE IV______________________________________RAW MATERIAL WEIGHT PERCENT______________________________________Talc (S. #200) 41.61Talc (W. #6) 27.87Alumina 29.04Plasticity vehicle 1.48______________________________________
The composition expressed as the component oxides in weight percent is shown in Table V.
TABLE V______________________________________OXIDE WEIGHT PERCENT______________________________________SiO.sub.2 48.39MgO 14.02Al.sub.2 O.sub.3 36.59Fe.sub.2 O.sub.3 0.33TiO.sub.2 0.05CaO 0.11Na.sub.2 O 0.07K.sub.2 O 0.45______________________________________
This composition melts at 1410° C. and becomes plastic within the range of about 1370° C. to 1400° C.
The ribbed layers were cut into sections having length dimensions (the dimension parallel to the ribs) approximately twice the width dimension. Approximately square layers were then formed by abutting two ribbed layers together along their length dimensions, and by placing the cement-filled channel member over the outermost ribs of the abutting layer sections. The square layers were then stacked so that the ribs of alternate layers were transverse to one another, and so that the overall height of the stacked structure was approximately equal to the length and width dimensions, forming an approximately cubic stacked structure. The structure was fired at approximately 1400° C., at which the cement took on a plastic state and wetted the surfaces of the contact layers.
The fired assemblies were then tested for leakage by incorporating them into a metallic housing of the type shown in FIG. 6, attaching one outlet of the housing to a blower and sealing the opposite communicating outlet. Thus, air forced into the recuperative structure could exit through the remaining outlets of the housing only by leaking into alternate transverse layers whose cells communicated with these unrestricted outlets. Visual inspection indicated acceptable leakage.
Referring now to FIG. 6, there is shown a recuperative apparatus 60 in which the completed ceramic structure 61 is incorporated into a metallic housing 62.
The metallic housing 62 may be formed of a single casting, or of machined and welded parts, and is preferably of a corrosion resistant metal such as stainless steel in corrosive applications and above 600° F. housing outer skin temperatures. Tapered conduit portions 52 and 52' terminate in flanged portions 53 and 53' for connection into the incoming heating or combustion air or fuel line. Sidewall portions 54 and 54' define openings terminating in flanged portions 55 and 55' for connection into the exhaust heat or flue gas outlet. The ceramic recuperator is thus heated by the passage of hot exhaust gases through it, and incoming cold air or fuel is in turn preheated as it passes through in the transverse direction.
Because of the large differences in thermal expansion coefficients between most ceramics and most metals, and the relatively high thermal conductivity of most metals relative to most ceramics, seal 57, having both resilient and insulating properties is used to maintain an effectively gas-impervious seal between the ceramic core 51 and the metallic housing 50. A detailed description of such a composite seal is not a necessary part of this invention. An example of a composite seal suitable for use in the apparatus of this invention is described in detail in Ser. No. 686,040, referred hereinabove.
Sidewall portion 54 of the metallic housing defines an opening just large enough to admit the recuperator cellular structure 51 and seal 57 after expansion of the metallic housing by moderate heating. Thus, upon cooling, a force fit is achieved. After placement of the structure in the housing, a ceramic insert 56, preferably cast in situ, is positioned atop the structure to contact the mating surface of a ceramic lining of an exhaust or flu gas opening or conduit. Flange 55 connects to the flu gas conduit or furnace housing and maintains the ceramic members in intimate contact.
Referring now to FIG. 7, there is shown in schematic form an arrangement whereby recuperator 61 is installed on the exhaust ports 62, 63 and 64 of a three zone natural draft tunnel furnace 60. Preheated combustion air is supplied through conduit 65 to burner inlets 66, 67, 68, 69, 70 and 71. This is of course but one example of numerous arrangements which may be used to realize the advantages of the invention. Furnaces, ovens, calciners and preheaters of any design may incorporate one or more of these recuperative apparati in order to improve efficiency of operation.
While there has been shown and described what are at present considered the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention as defined by the appended claims. For example, the substantial rectangular cell cross-sections could be replaced by a sinusoidal configuration produced by contacting corrugated and flat layers. | Layered composite cross-flow ceramic recuperators having minimal leakage between layers and consequent high efficiencies are utilized for industrial waste heat recovery in an apparatus in which the ceramic recuperator is surrounded by a metallic housing adapted for coupling to the metallic fittings of existing furnaces, calciners, ovens and preheaters. The ceramic recuperators are formed from stacks of bi-sectioned ribbed layers, the sections of each layer being sealed together to minimize leakage of the heat transfer fluids between layers, and thus to increase the efficiency of the heat transfer. | 5 |
This is a division, of application Ser. No. 630,930, filed Nov. 11, 1975.
BACKGROUND OF THE INVENTION
The present invention relates to devices and techniques in the field of guided wave transmission of light through optical waveguides. More specifically, the present invention relates to the structure and method of manufacture of a device for connecting and disconnecting ends of optical fiber waveguides.
In recent years, significant advances have been made in the technology of transmitting information with low loss by light beams through thread-like optical glass fibers. The use of light as a medium of communication is of great commercial interest since optical fibers promise much more channel capacity than microwave waveguides and electrically conducting transmission wires. The fibers are inexpensive and compact, and they are compatible with transmitters, repeaters and receivers of miniature size.
As optical transmission systems have developed, the need has increased for an inexpensive device for connecting and disconnecting optical fibers to facilitate insertion, removal, and testing of network components. Such a connector should be relatively small, convenient to use, require little maintenance, and offer little obstruction, or loss, to the passage of light through its structure.
Discontinuities in the refractive index of the light path contribute to light loss. To reduce the loss a substance is often placed between the fiber ends which is such as to have a refractive index which matches the index of the light path in the fibers. Unfortunately, index matching in the prior art has been accomplished by liquids having obvious maintenance disadvantages and by adhesives not readily disconnectable without some step such as heating.
Furthermore, when the optical fiber end diameters are on the order of 0.1 millimeter or less, precise alignment of the ends and close approach are also required for low light loss. Heretofore, many optical connector devices have required tedious adjustment to achieve alignment and close approach of the ends.
SUMMARY OF THE INVENTION
The maintenance disadvantages and connectability inconveniences of prior art fiber optic connectors are now avoided in the present invention by the principle of flexible interfacing. In the invention each fiber end is provided with a transparent, flexible protective contact body of silicone rubber or equivalent material so that runny liquids are unnecessary. A fiber alignment holder makes the fiber ends collinear for low loss. The contact bodies located on two fiber ends are brought and held together so that they touch and flex, completing the optical connection. Disconnection is accomplished by a mere reverse motion interrupting physical contact so that the flexible material assumes the unflexed shape. In this manner the invention avoids the disadvantages associated with the use of adhesives as well. When the contact bodies are substantially index-matched to the fibers, discontinuities are eliminated and light loss is significantly reduced. Since the contact bodies are flexible, end separation tolerances of the fibers in the holder are not stringent.
In one feature of the invention which is especially advantageous when small-diameter fibers are involved, each optical fiber end is surrounded by an inexpensive epoxy or polyester molded connector body having a surface in the shape of a frustum aligned with the optical fiber core axis. The connector bodies are either shaped to be matable to each other or shaped for use with a connector body support having a pair of opposed frustum surfaces matable with the connector bodies. A tiny drop of silicone rubber, epoxy or equivalent material is applied to the fiber end to form the contact body which cures and also adheres to an adjacent portion of the connector body.
The unusual advantage of the frustum shape relates to practical considerations. Provision of mating surfaces in the shape of a frustum translates variations in physical size of the mating parts (due to manufacturing and temperature fluctuations) into fiber end separation variations, thus avoiding fiber end misalignment and consequent light loss. The end separation variations are no problem since they are compensated for by the flexible contact bodies. Consequently, the invention provides a quick-disconnect low loss optical fiber connector requiring no tedious adjustments to align even the smallest fibers.
Some of the many embodiments, features and advantages of the present invention are described in more detail hereinbelow in connection with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cross sectional view of an optical fiber connector according to the invention showing two optical fiber connector subassemblies in connected position.
FIG. 2A is a magnified cross section of the invention in an optically disconnected state. FIG. 2B is the corresponding cross section of the invention when optical connection is made.
FIG. 3A is a simplified elevation view of three molding blocks in a molding assembly used in an embodiment of the inventive method of manufacturing an optical fiber connector. FIG. 3B is a detailed cross section of the molding assembly of FIG. 3A partially disassembled.
FIG. 4 is a cross sectional view of an alternative form of optical fiber connector subassembly made in accordance with the inventive method.
FIG. 5 is a pictorial illustration of steps for applying a clear, flexible index matching dome in accordance with the inventive method.
FIG. 6 is a perspective view of a rack-mounted optical fiber connector assembly according to the invention.
FIGS. 7A and 7B are cross sections of the optical fiber connector assembly of FIG. 6 shown in disconnected and connected conditions respectively.
DETAILED DESCRIPTION
In FIG. 1, socket 1 supported by base 6 holds connector bodies 3 and 3', which have frustum-shaped mating surface portions 2 and 2' respectively opposably received in the socket. Connector bodies 3 and 3' surround optical fibers 5 and 5' which are supported by sleeves 4 and 4' respectively. The optical connection is made within socket 1 in a manner more clearly illustrated in magnification in FIGS. 2A and 2B.
FIG. 2A shows conical frustum portions 2 and 2' and socket 1 just prior to completion of the optical connection. The frustum portions 2 and 2' have tips 12 and 12' respectively which surround the ends of optical fibers 5 and 5'. Optical fiber end faces 13 and 13' are exposed to each other in opposed orientation. End faces 13 and 13', as well as the adjacent parts of tips 12 and 12', are covered by clear, flexible, index matching, adhering contact body domes 11 and 11' respectively.
Then optical connection is made as shown in FIG. 2B. Flexible domes 11 and 11' come together so that they touch and flex, completing the optical connection. At the same time frustum portion 2 comes into physical contact with matable receiving surface 10 of socket 1 so that the fiber ends are aligned collinear. A light ray 15 passing through the end of fiber 5 leaves end face 13 and passes into dome 11 with minimal reflection or loss when dome 11 is matched in refractive index with the light carrying path of fiber 5. The light, now indicated as ray 16, passes through dome 11 and enters dome 11' at a flexible interface or contact region 14. Again, light loss is negligible since there is no refractive index discontinuity at the interface, for instance when there is a "wetting" phenomenon thereat, as is observed microscopically. The light passes into end face 13' of fiber 5', continuing along fiber 5' as ray 17.
In the optical fiber connector of the invention, the apex half-angle 18 of the conical mating portion is selected to provide support for and secure alignment of the optical fiber ends. Generally speaking the appropriate apex half-angle 18 has a lower limit at which the mating surfaces illustrated by surfaces 2 and 10 become self-locking and an upper limit of about 45° at which surface 10 ceases to provide significant support for conical frustum portion 2. Portion 2 can also be a pyramidal frustum, and similar surface angle considerations apply.
In an experiment with a fiber optic connector devised according to the invention, it was found that an apex half-angle of about 10° provided excellent support without self-locking. Graded index multimode fibers having a 55 micron diameter core and a 110 micron diameter cladding were used. The axis of the core varied at most by 1.2 microns from the axis of the cladding outer surface. The connector was designed to reduce the angular misalignment of the cladding axes of the fiber ends relative to each other to less than 1° and the distance between the cladding axes to less than 3 microns. When the optical connection was completed, the nominal separation between the fiber end faces 13 and 13' was 30 microns. The width of the flexible domes 11 and 11' covering the fiber end faces 13 and 13' and the adjacent portions of tips 12 and 12' was approximately 5 fiber diameters. The substance of the domes covered the fiber end faces to a depth of 50 to 100 microns. In the connected state the substance was squeezed by a factor of more than 2 to 1 so that the end separation of 30 microns was achieved. The socket had two opposed, conically hollow, coaxial, receiving surfaces 10 and 10' machined from brass, and the connector bodies were composed of a transfer molded compound.
Tests of the light loss in the optical fiber connector just described were performed with a beam of coherent light from a helium-neon laser having a wavelength of approximately 0.63 microns. Each of many connector bodies 3' of FIG. 1 was rotated outside of socket 1 and reinserted at least six times against the dome 11 on a standard body 3 so that the worst case of transmission loss for each could be measured. A total of 198 dome-and-connector-body subassemblies were tested, and 90 percent of the connections had worst case transmission loss of 0.14 dB or less, eminently suitable for use in optical communications systems.
The success of this novel connector is attributable in large measure to the convenience of the index-matching contact body approach. Index-matching reduces transmission loss caused first by Fresnel reflection of some light from each fiber end face and, second, by diverging of the rest of the light by Fresnel refraction as it passes through an end face. If no index-matching were used, the transmission loss would be approximately 0.6 dB greater due to the Fresnel reflection and refraction effects associated with fibers of refractive index 1.5 in air.
However, the advantages of an optical fiber connector employing flexible interfacing are of even wider scope, especially when very small diameter optical fibers are involved, because the invention includes a novel method of manufacture of the special subassemblies of FIG. 1. The method aspect of the invention for making each connector body and dome subassembly lends itself readily to inexpensive precision alignment of even small diameter fibers in the connector body and application of the flexible dome so as to be practical for large scale commercial production and use in the field without tedious adjustments. In the inventive method, broadly stated, the connector body is first made to surround the optical fiber end, and second, the contact body substance is applied to the fiber end face and cured flexible. Detailed features of this method disclosed hereinbelow will serve to suggest its scope.
The connector body used in the present invention is conveniently and inexpensively manufactured by the use of a molding assembly such as that illustrated in FIGS. 3A and 3B. The double conical socket also lends itself to fabrication by molding.
In FIG. 3A, which is simplified compared to FIG. 3B, precision molding die 20 of approximately cubical outline has a precision machined frustum cavity 24. Precision die 20 is placed in a holder (not shown) together with lower connector-body block 21 and upper connector-body block 22 which are shaped so that a cylindrical cavity 25 for the connector body is also provided.
Referring now to FIG. 3B, some numbers of which correspond to those used in FIG. 3A, precision molding die 20 is shown in cross section. Lower body block 21 is shown exposed by removal of upper body block 22. Die 20 interfaces with body blocks 21 and 22 at plane 23.
Fiber 5 is clamped or otherwise held concentrically in the molding cavity 24, 25. If the molding compound used has a viscosity and flow rate which are such as to deflect or break the fiber during the molding process, additional support, suitably by a metal sleeve 4 is provided.
Supporting sleeve 4 is placed in the cavity as shown and is itself supported in a recess of body block 21 beneath sleeve 4. Optical fiber 5 is threaded through sleeve 4 and guided into orifice 27 by chamfer 26 so that the end of fiber 5 is aligned coaxial with the frustum-shaped die cavity 24 with an angular error suitably less than 1°.
Teflon washers 36 and epoxy cement 37 hold the fiber in place in sleeve 4, or a teflon inner sleeve crimped by sleeve 4 may also be used for this purpose. In another variation in which the fiber, say in a cable, has a thick plastic protective jacket, the sleeve is made large enough to admit the jacket and be crimped thereon, holding the fiber in place.
Precise centering and sealing of fiber 5 in orifice 27 is accomplished by compression of an annulus 28 in a channel 29 by a piston 30 having a head 32 with a bearing surface against which screw 33 is tightened. Screw 33 has a slot for screwdriver adjustment from the exterior of the die. Annulus 28 is previously suitably molded around a concentrically chamfered pin using a molding substance of a silicone rubber or other material able to withstand elevated temperatures and exhibit essentially no decomposition when heated in a confined space. The temperature-vulcanizing potting resin Dow Corning Sylgard 185 is suitable for this purpose, and is commercially available from Dow Corning, Midland, Michigan.
Precision chamfer 38 is found to enhance the centering capabilities of annulus 28. Chamfer 38 is made concentric with the tapered surface of cavity 24 to within less than a micron, but the chamfer apex half-angle is noncritical and suitably 75°.
Annulus 28 is compressed until the ultrasonically cleaned fiber 5 may just be admitted along guide chamfer 26, through orifice 27, through annulus 28 and about 2 centimeters further through a channel 31 of piston 30. If a nylon or other soft coating on the fiber is employed, the coating should previously be stripped at least in the region between sleeve 4 and piston 30 for the most precise centering of the fiber. Then the assembly of upper body block 22, lower body block 21 and precision die 20 is put together and elevated to a transfer molding temperature.
A suitable transfer molding compound is one having good dimensional stability, linear shrinkage, low coefficient of expansion, and abrasion resistance. The molding flow should be soft so as to avoid fiber deflection or breakage. The thermosetting time should be short so as to reduce the cycle time of manufacture. Moldable polyesters and moldable epoxies are convenient and suitable for use as the moldable compound. Inclusion of silica or other mineral fillers stabilizes the molded medium, reduces shrinkage, and improves surface abrasion resistance. The particular molding product used in demonstrating the present invention was Hysol Epoxy Molding Powder, MG6 Mineral Filled, which, as sold by the Hysol Division of Dexter Corporation, Olean, New York, refers by label to U.S. Pat. No. 3,484,398.
The MG6 molding powder is preheated for six minutes at 85° C. A vacuum gate 35 is used as a port for evacuating the molding die cavity to 0.01 Torr just prior to admission of the molding compound. Then the MG6 is forced at 410 to 450 psi through 2 mil wide entry gate 34 into the cavity which is at a temperature of 150°-160° C. The width of the vacuum gate 35 is 1 mil, which is small enough so that the mineral filled transfer molding compound is admitted at the entry gate but cannot leave through the vacuum gate. The molding compound passing through the entry gate surrounds the optical fiber end as it rapidly fills cavities 25 and 24 and passes along chamfer 26 toward orifice 27, which is closed at the transfer molding temperature by thermal expansion of annulus 28. The molding compound entrains any residual gas in cavity 24 and carries it into the interior of sleeve 4. In this manner, a connector body having a precisely conical frustum mating surface is molded around the end of fiber 5, which in turn is accurately aligned coaxial with the conical frustum mating portion of the molded body. The connector bodies produced had dimensions as follows: 6.34 millimeter cylinder body diameter, 10° taper apex half angle, and 5.6 millimeter taper length. The molded body is cured for 5 minutes, cooled to relax the annulus, removed from the mold, and postcured for 4 hours at 150° C.
It should be clear that many of the details of the molding process are related to the properties of the specific molding compound employed. Thus, while Hysol MG6 was used in demonstrating the invention, the scope of the inventive method is not intended to be limited by the above disclosure of a particular process for transfer molding one substance around the fiber.
To additionally suggest the scope of the inventive method, FIG. 4 shows an alternative approach in the manufacturing step of surrounding the end of an optical fiber with a connector body. In this aspect of the method, a connector body 40 having conical mating surface 42 is transfer molded so that it has a channel 43 of tapered shape so that the connector body 40 may be affixed to the fiber 41 in any suitable manner. The channel 43 has a wide receptive opening and guide taper for easy threading insertion of the fiber 41 through it, even in the field. Angle 46 of the portion of the taper near the body tip 45 is chosen small, suitably 2°, so that angular misalignment of the fiber axis is negligible.
The channel 43 is formed by molding the connector body 40, in a way similar to the process illustrated in connection with FIG. 3B, around a tapered mandrel provided in place of sleeve 4. The mandrel has a shape corresponding to the shape of channel 43 and has a wire-like end only slightly larger than the optical fiber diameter. The mandrel end extends through orifice 27 of FIB. 3B and is grapsed by annulus 28 during the molding process.
When the molding process is completed, upper body block 22 is removed, precision molding die 20 and connector body 40 are elevated relative to lower body block 21, and connector body 40 is removed from cavity 24 in die 20. The mandrel, which has a major end protruding from the connector body 40 like one end of sleeve 4 of FIG. 1, is then grasped at the major end and extracted from connector body 40.
The connector body 40 is conveniently affixed to optical fiber 41 by means of an adhesive 44 which may be of any appropriate material capable of bonding to the connector body material and the glass fiber. Satisfactory adhesives for an MG6 epoxy connector body and a nylon coated glass fiber include fast curing epoxies, one example of which is Bipax Tra-bond BA 2106T, commercially available from TRA-CON, Inc., Medford, Massachusetts.
If the optical fiber end face has not previously been prepared, the end face is produced smooth and perpendicular to the fiber axis near or at the connector body tip as shown in FIG. 2A. When the connector body is removed from the mold of FIG. 3B, for instance, the end of fiber 5 protrudes from the body tip by a few centimeters. The fiber can be broken off to achieve a flat and perpendicular end face near the tip by using tension, bending and scoring of the fiber according to "Optical Fiber End Preparation for Low-Loss Splices," by D. Gloge et al, Bell System Technical Journal, Vol. 52, No. 9, November 1973, pp. 1579-1588.
FIG. 5 shows a method for accomplishing the application of the flexible contact body dome (47 in FIG. 4). Applicator tip 50 is dipped in a flowable liquid contact substance 51 which is held in container 52. Next, applicator tip 50 is retracted so that it holds a drop of the substance 53 which is transferred in the direction of arrow 54. Then drop 53 is applied by applicator tip 50 as contact body dome 55 so that it is located over and covers the end face of end 56 of fiber 57 and at least a portion of tip 58 of connector body 59, to complete the optical connector subassembly. Other methods for applying a contact body may, of course, be readily devised.
The contact body 55 is fashioned in a convex dome shape by application of the drop 53, but other contact body shapes could conceivably be employed. Any shape of contact body which flexes upon touching another contact body so as to form a continuous optical path without air inclusions or other discontinuities is satisfactory.
Substance 51 can be of any suitable type which can be conveniently applied, cures flexible and transparent at a fiber transmission wavelength, preferably with a good refractive index match to the end surface of the fiber employed, and adheres to the connector body tip. Commercially available preparations which are satisfactory include epoxy and silicone rubber compounds.
Among the silicone rubbers the "one-pack" room temperature vulcanizing rubbers offer advantages including no need for mixing of separate packaged products and convenient curing in the humidity of room air. See "Silicone Liquid Rubber," by J. A. C. Watt, Chemistry in Britian, Vol. 6, No. 12, pp. 519-524 (1970). One commercial product which proved satisfactory in experiments is Dow Corning 3140 room temperature vulcanizing (RTV) silicone rubber, which cures in 24 to 72 hours at room temperature and 20 percent humidity with no corrosive byproducts. The cured product is well suited for applications in the field, since it remains flexible over the temperature range -65 to 200° C. As cured, 3140 RTV silicone rubber has a refractive index of 1.46, which is an excellent index match to the germania doped low loss quartz fiber of index 1.458 used in the experiments.
Examples of other substances which may find use with fibers having a different refractive index are:
(1) Dow Corning 734 RTV silicone rubber, n = 1.475.
(2) Epoxy castgel 904 from Castall, Inc., East Weymouth, Mass., n = 1.477.
(3) Duralco 5300 transparent epoxy gel from Cotronics Corp., New York City, n = 1.523.
The principles of the present invention may be applied in fabricating a wide variety of optical fiber connector designs. One such design for making optical connection between a rack and a rack mounted module is shown in FIG. 6.
Module connector housing 61 and rack connector housing 62 are affixed to the module and rack (not shown) respectively with rivets or screws through holes, including holes 63 and 64. A transmitter optical fiber 65 surrounded by connector body 66 is plugged into module connector housing 61 through chamfer 67 (see also FIG. 7A); and transmitter fiber 68 surrounded by connector body 69 is plugged into rack connector housing 62 in similar fashion. Receiver optical fiber and connector body subassemblies 65', 66' and 68', 69' plug into chamfers such as 67' in identical manner. When the module is mounted in the rack, beveled guide pins 70 and 73, which are laterally offset from the optical fiber axes, and enclose no part of any light path in FIG. 6, are inserted into guideways 71 and 74 which feature capturing chamfers 72 and 75 respectively. In this manner, a coarse alignment of the optical fiber axes is accomplished. As the guide pins slide into the guideways, they engage spring-loaded pusher pins (not shown, riding inside the guideways), each of which has riding in a slot 82 a lever pin such as 81 for pushing on dust cover 79. The engagement, of course, in no way affects the coarse alignment previously accomplished. Dust cover 79 turns around pivot 80, which is suitably spring loaded. Thus, when the dust cover 79 is raised, the tip 95' and flexible contact body 96' of connector body 69 are exposed in channel 77 near receiving guide cone 76, a similar description applying relative to connector body 69' as well. It is readily apparent that a host of dust cover arrangements and mechanisms are suitable for use in connectors according to invention.
FIGS. 7A and 7B show a cross-section along section plane 7A of FIG. 6 featuring connector bodies 66 and 69 surrounding optical fibers 65 and 68, which are in coarse alignment due to the engagement of the guide pins 70 and 73 as previously described. The connector bodies 66 and 69 have been placed in module connector housing 61 and rack connector housing 62 and are held and retained therein by means of crown springs 90 and 90' respectively at necks 91 and 91' and indents 92 and 92'.
Connector body 69 has its mating cone 94' securely held against receiving cone 98 in channel 97' by the force of crown spring 90' on indent 92'. Tip 95', to which dome 96' adheres, is positioned in channel 77. Connector body 66 is loosely held by crown spring 90 at neck 91 so that cylindrical surface portion 93 is surrounded by channel 97 so that mating cone 94 having tip 95 and dome 96 is prepared for completion of the optical connection.
In FIG. 7B, the optical connection is completed when module connector housing 61 is placed flush against rack connector housing 62. Connector bodies 66 and 69 come together so that clear, flexible domes 96 and 96' touch and flex, completing the optical connection. Axial alignment is accomplished as mating cone 94 is pressed securely against receiving surface 76 by the action of indent 92 being pressed backward against the force of crown spring 90. In this manner the spring retention via the connector bodies holds the contact bodies and fiber ends in the optically connected position. It is to be noted that cylindrical portion 93 is deflected in channel 97 so that the axial alignment may be accomplished in accordance with the invention. Abrasion is minimized since full surface contact is achieved only at the very last instant of the connection.
The frustum-shaped hollowed receiving surfaces 76 and 98 of the connector can advantageously feature radiating lateral grooves as shown on receiving cone 76 of FIG. 7A. The lateral grooves capture dust which may enter the region, and they facilitate a self-cleaning action when the connector body 66 is repeatedly connected and disconnected.
In another feature of the invention, surface 94' of connector body 69 is fused or molded continuous with surface 98 so that housing 62 amounts to a connector body of female type mutually matable disconnectably at receiving surface 76 with the frustum mating surface 94 of connector body 66. It may be found in certain embodiments of the invention that a key-and-slot or other means for limiting rotation of the connector body around its axis is desirable so that distortion of the contact bodies and abrasion of the mating surfaces is minimized.
It is of course to be understood that the embodiments of the present invention hereinabove discussed are merely illustrative of an even wider variety of embodiments useful in practicing the invention. In all cases the scope of the invention is to be interpreted as defined by the appended claims. | A method of fabricating an optical fiber connector is disclosed using a transfer molding process employing a precision die whose interior surface defines a frustum for forming the mating surface of the connector. The fiber is inserted through the mold cavity and extends through an aperture in the end surface of the frustum and through an annulus disposed outside of the mold cavity immediately adjacent to the aperture. At the transfer molding temperature, the annulus expands inward radially, simultaneously sealing the aperture and centering the fiber. After curing, the excess fiber is removed, and a flexible, dome-shaped contacting member is formed over the fiber end. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 09/782,620 filed Feb. 13, 2001.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus and system for implementing variable-length file headers, and in particular to a file header that utilizes a varying number of parameters to store meta-data about the contents of the data stored in the file.
2. Description of Related Art
Electronic files have long been used to store data used in computer applications. While at the most basic level, all electronic files contain a collection of bits and bytes, the format of the data in an electronic file may vary greatly. For instance, a simple data file may contain a number of records that are all arranged into a predefined format. In the simplest case, the format is identical for each record. For example, a simple data file may contain records that are formatted to include an integer record number field, a date field, and a 2-character text field. In this case, each record is exactly the same length, as each record has exactly the same fields, and each field has a predefined length.
Data files containing fixed-length records have limitations though, as all of the data must be in the predefined format. Because the data has to be structured into fixed format records, many types of data, such as bitmap images, cannot be stored in files comprised of fixed-length records. Therefore, alternative file formats have been developed. One widely used method of structuring data in an electronic file is to store information about the data, the “meta-data”, in a file header section of the file, while storing the data itself in a data section of the file. The meta-data in the header section typically provides information to application reading the electronic file about how to read, interpret, process or display the data stored in the data section. Typically, file formats that incorporate file headers have a predefined file header section at the beginning of the file followed by a variable-length data section. By storing the meta-data in a predefined format, it is relatively easy for an application to read and use the data by simply parsing the known format of the header to obtain the information needed to read, process or interpret the data in the data section.
The use of file headers has made it possible for data that cannot be stored in fixed-length record formats to be stored in an electronic file in a format that can be used by many applications. For example, several different platform-independent formats have been developed for the storage of bitmap image data in electronic files. Most of these file formats consist of two sections—a file header and a binary image data section, although some formats may have additional sections in the file. The header may be separated from the image data by a special control character, or the header may be defined in such a way that the application reading the file can determine where the image data is stored within the file. The header section typically contains information about the image, while the image data section contains the actual image data. BMP (Windows), PCX (PC Paintbrush), and GIF (Graphics Image Format) are all examples of image file formats that utilize file headers.
Image file headers typically define the image size, number of colors, and other information needed by an application to display the image. FIG. 1 illustrates the structure of the file header used in BMP files. As shown, each field in the header is of a fixed length, and every field must be present in the correct order for an application reading the file to properly display or use the image data, even if some of the fields in the header do not have a value. The BMP file header is always exactly 54 bytes long.
File formats with these types of predefined, fixed-length file headers are limited in many ways. Only very particular, pre-determined information or meta-data can be stored in the header. While some fields in the header may be reserved for future use, it is very difficult to change the file header after it has been defined and in use, as every application that uses the fixed format must be updated if the format is changed.
These types of fixed file header formats work well for data that does not require a large amount of meta-data, such as a simple bitmap image file. However, there are cases when it would be desirable to store varying amounts of diverse meta-data in a file header. One example of a situation where fixed-length predefined file headers are inadequate is described in co-pending U.S. patent application Ser. No.09/782,620, entitled “Method and System for Extracting Information from RFQ documents and Compressing RFQ files into a Common File Format”, filed Feb. 13, 2001, which is hereby incorporated by reference. As described in this application, the current assignee has developed a method and system of converting numerous types of electronic documents into a common compressed file type, whereby a single viewing application can be used to view any document that has been converted to the common compressed file type.
Many different types of files can be converted into a single common file type using the disclosed method and system. Because of the wide variety of information that may be in the original documents, it is difficult to define a fixed-format file header that will capture all information that may be desirable to store with the compressed data. Even if it were possible to define a fixed-format that would adequately store data for all currently known types of information, it is impossible to predict what additional types and amount of information that would be desirable to store in the future.
Thus, what is needed is a method and system for storing variable amounts and types of information in a file header.
SUMMARY OF THE INVENTION
In accordance with one form of the present invention, there is provided a method and system of creating a file header for a computer file that provides meta-data about data stored in a data portion of a computer file, wherein the header is comprised of a plurality of header fields. The method includes storing a data tag in each header field, whereby the data tag indicates the type of header field; and for storing a meta-data item for each header field, whereby the type of meta-data item is defined by the data tag; whereby at least one header field contains a meta-data item used by an application to categorize the computer file.
A method and system for ensuring that a file originating on a first computer running a first application is stored in a proper location on a second computer running a second application, where the file is comprised of a file header section and a data section is also disclosed. The method includes inserting storage location information in the file header by the first application; extracting the storage location information from the file header by the second application; and determining a storage location on the second computer by the second application based on the extracted storage location information.
A method and system for creating the header portion of a computer file comprised of a header portion and a data portion, wherein the header portion provides meta-data about the data stored in the data portion, wherein the header portion is comprised of at least one field is also disclosed. The method includes storing a data tag in each header field, whereby the data tag indicates the type of field; and storing meta-data about the data portion of the file in each header field whereby the meta-data in the field is defined by the data tag in the field, for each field in the header; whereby the meta-data in at least one field is comprised of data that is used by an application to define an expiration date for the computer file.
A method and system for ensuring that a user obtains a correct version of a file, where the file is comprised of a file header section and a data section is also disclosed. The method includes inserting expiration information in the file header by a first application; extracting the expiration information from the file header by a second application; determining an expiration date for the file from the extracted expiration information by the second application; and comparing the determined expiration date to another date by the second application; wherein use of the file is disallowed by the second application if the comparison determines that the file has expired.
A method and system for creating the header portion of a computer file comprised of a header portion and a data portion, wherein said header portion provides meta-data about the image stored in the image data portion, wherein the header portion is comprised of at least one field is also disclosed. The method includes storing a data tag in each field of the header, whereby a data tag indicates the field type; and storing meta-data about the image data portion of the file in each field whereby the type and format of the meta-data in the field is defined by the field's data tag; whereby the meta-data in at least one field is comprised of data that is used by an application to automatically configure how the image stored in the image data portion is displayed.
A method and system for displaying an image in a predetermined view state, where the image is stored in a file comprised of a file header section and an image data section is also disclosed. The method includes a first application inserting view state information in the file header; a second application extracting the view state information from the file header; and displaying the image by the second application, wherein the second application uses the extracted view state information to configure the display of the image.
Accordingly, the present invention provides solutions to the shortcomings of prior file acquisition and processing techniques. Those of ordinary skill in the art will readily appreciate, therefore, that those and other details, features, and advantages will become apparent in the following detailed description of the preferred embodiments.
DESCRIPTION OF THE FIGURES
The accompanying drawings, wherein like references numerals are employed to designate like parts or steps, are included to provide a further understanding of the invention, are incorporated in and constitute a part of this specification, and illustrate embodiments of the invention that together with the description serve to explain the principles of the invention.
In the figures:
FIG. 1 is a table illustrating the format of the Windows BMP file header.
FIG. 2 illustrates the format for a RFQ compressed file.
FIG. 3 is a table illustrating some of the codes that may be used as header tags.
FIG. 4 illustrates an example interface for entering header information during the conversion process.
FIG. 5 illustrates an original view of a drawing after conversion.
FIG. 6 illustrates a rotated view of the drawing in FIG. 5 .
FIG. 7 illustrates a scaled version of the drawing in FIG. 6 .
DETAILED DESCRIPTION
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. It is to be understood that the Figures and the description of the present invention included herein illustrate and describe elements that are of particular relevance to the present invention, while eliminating, for purposes of clarity, other elements that may be found in typical auction systems and computer networks.
It is worthy to note that any reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
The present invention is directed to a method and apparatus for a variable-length file header. The invention is described herein using the file conversion process described in co-pending U.S. patent application Ser. No. 09/782,620, previously incorporated by reference, as an example. The method disclosed in this co-pending application compresses a file such that no information is lost in the conversion process and a single viewing application can be used to view the resultant compressed file. However, other types of files besides files converted using the disclosed method may use the file header apparatus and system of the present invention, and it is intended that the scope of the present invention cover any such case.
The method and system of previously incorporated by reference co-pending U.S. patent application Ser. No. 09/782,620 will be briefly described so that it can be used by way of example herein. In brief, a Request For Quotations (RFQ) is used to provide information to potential bidders in an electronic auction, or in other procurement processes, about the services or goods in the auction. For example, a RFQ may contain engineering drawings, manufacturing specifications, quality specifications, auction specific information and buyer information. In order to publish an electronic RFQ, all of this information must be gathered from different sources, and converted to a common electronic file format. The system disclosed in the co-pending Application is used to convert the various documents from their native formats to a common format. The system extracts important information from documents, converts the documents into raster images, compresses the raster images and then stores the compressed images with the extracted information in an “RFQ compressed format” file. Although the term “RFQ compressed format” is used herein, it will be obvious to those skilled in the art that the disclosed compressed file format could be used by many applications other than the electronic RFQ publication.
The electronic files may first be converted to an intermediate file format, such as PDF (Portable Document Format from Adobe Acrobat). In one embodiment, hyperlink information may be extracted from text documents and saved. In another embodiment, symbol information in CAD files may be extracted and saved. All documents are converted into a common raster image format, such as TIFF (Tag Image File Format). Once the documents have been converted into the common raster format, the raster images are compressed preferably using a wavelet compression scheme. Wavelet compression creates a highly compressed file format suitable for transmitting over low bandwidth connections. Any information that may have been extracted may be reinserted into the compressed file, and a “RFQ compressed format” file is created.
Both text-based documents and engineering drawings are converted to one common format. By compressing all of the files into a common format, only one viewing application is needed, and the viewing time is minimized. No matter what native format a document in an RFQ started as, when it is delivered as part of the electronic RFQ generated by the disclosed system, only a single viewing application is needed to decode and view the document. The RFQ compressed format therefore provides for the consolidation of all data across a common format, while preserving valuable information from the RFQ input files.
It is therefore advantageous to “publish” an electronic RFQ such that all of the RFQ documents are stored in the RFQ compressed format. By using a single file format, a reader of the RFQ need only have a single viewing application to view every document in the RFQ.
In a preferred embodiment, the RFQ compressed file format follows standard industry practice, and is comprised of a file header followed by the compressed data. As is typical for most file headers, the RFQ compressed file format header contains meta-data, or information regarding the compressed data that follows it. Some of this information is typical display and compression information, however, the RFQ compressed file format header may also store additional meta-data about the document that is compressed within the file.
An electronic RFQ used in an online auction contains a wide variety of information. Within a single RFQ, there may be many different types of documents that originated as text, image or CAD drawings. In addition, different buyers have different requirements and utilize different systems to create the documents that are used in an electronic RFQ. It is desirable to store this information relating to the original documents with the converted document. It is desirable to store information about an online auction with any converted documents that are used in that online auction's electronic RFQ. It is desirable to store other types of meta-data with the converted document.
However, only one format for a RFQ compressed file can exist. It would be extremely difficult to try to anticipate every type of meta-data that could be stored with the converted document and create a field for it in the file header. In addition, it would be very wasteful to include every possible field in every RFQ compressed file, as some of the fields will only be used in limited situations. Therefore, the assignee of the present invention has created a variable-length header for the RFQ compressed file.
FIG. 2 illustrates the structure of the RFQ compressed file using the variable-length file header of the present invention. Block 240 represents the entire RFQ compressed file, which is comprised of header 230 and data 235 . In a preferred embodiment, header 230 is comprised of an identifying section 210 and header data section 220 .
The identifying section of the header 210 is shown with four fields, although more or fewer may be used. In the example shown in FIG. 2 , the identifying section 210 is comprised of an ID Tag field 201 , Cipher flag field 202 , Cipher key field 203 and Offset 204 . ID Tag field 201 is preferably an ASCII tag indicating the file type. Cipher flag field 202 is preferably a flag indicating whether enciphering is in use. If the file is enciphered, Cipher key field 203 is preferably used as an index into a key file. Enciphering will be described in more detail below. Offset 204 is preferably an integer that represents an offset from the beginning of the file to the beginning of the compressed data 235 . Offset 204 is typically the number of bytes from the beginning of the file to the data section.
In a preferred embodiment, header data section 220 and/or Offset 204 are enciphered to prevent unauthorized access and alteration of the data. A preferred cipher mechanism is the public domain Blowfish algorithm. Other cipher methods are known to those skilled in the art, and are intended to come within the scope of the present invention.
As shown by header data section 220 , the present invention utilizes tags in the header to allow for a variable number of fields in the header. Each field in header data section 220 consists of a data tag, the field's data and at least one control character used as an “end of field” character. As an alternative to control character(s), each type of header field may be of a known, fixed length. Header data section 220 may contain 0 to N data tags. It is this feature that provides flexibility. Any number of tags may be defined to allow for any amount of meta-data to be stored in the header. Unlike previous file headers having a fixed number of fields, the present invention provides for a variable number of header fields.
An application that parses the header of the present invention can then use any of the information stored in the header for any purpose. By using a tagged header format, the present invention allows for future tags to be defined. Because only fields that have information associated with them need to be saved in the file header, valuable space is saved. There is no requirement to have any tags saved with the file.
The software used to read, write, parse, and optionally encipher and decipher the header is preferably isolated as a component so that it may be reused by any application that accesses the RFQ compressed format files. The component may be delivered as a DLL (Dynamic Link Library) so that it may be embedded within an application to the prevent exposure of the API (Application Program Interface).
FIG. 3 illustrates some of the tags that may be used in the file header of the present invention. The tags shown in FIG. 3 demonstrate just an example of the types of tags that can be used in the file header apparatus of the present invention. The tag codes shown in FIG. 3 are codes identifying data that is useful to store in the context of electronic RFQs used in online auctions. As will be obvious to one skilled in the art, any number and type of code may be defined and used to identify a header field. Any type of information may be stored in the header. All that is required is that a unique tag code be defined for a particular piece of information.
Some of the codes shown in FIG. 3 are discussed in more detail below.
Auction and Customer Information
Due to the manual nature of the RFQ creation process, there is the possibility that files from one customer may inadvertently be placed in another customer's RFQ. For example, company X's engineering drawings end up in company Y's RFQ because a user processing files using a drag-and-drop operation accidentally places the files in the wrong location. The file header of the present invention can be used to mitigate this problem by storing customer and competitive bidding event information in the header of converted files. The tags that have been created for these fields are shown in FIG. 3 as Customer (CU), Competitive Bidding Event Number (CB), Competitive Bidding Event Revision (CR), and Competitive Bidding Event Release Date (CV).
When the electronic RFQ is published, this information may be verified to ensure that only files that are supposed to be published for a particular RFQ are indeed published. An application publishing the RFQ can perform the verification by comparing the Customer and/or Competitive Bidding Event information in a file's header against the RFQ's information. By using these fields in the header, the application can then perform referential integrity on the collection of files used in an electronic RFQ. As will be obvious to those skilled in the art, there are many other referential integrity applications that may use the variable length header of the present invention, and the present invention is not intended to be limited to the publishing electronic RFQs for online auctions.
An example of the interface that can be used to set these fields in a header is shown in FIG. 4 . This example interface is utilized in an application used to perform post-processing and quality assurance on files that have been converted to the RFQ compressed format. These RFQ compressed files will be used in the publication of an electronic RFQ for a particular competitive bidding event for the auction sponsor. As shown in FIG. 4 , the user enters the Customer, CBE (Competitive Bidding Event) Number, Revision and Release date. There are also fields that can be used to store the user's name, customer division that created the original file, drawing number information, customer site information, and so on. The fields shown in FIG. 4 may require manual entry, or they can be populated with default values during the conversion process that the user can change. Any part of or all of this information can be stored in the variable-length header of the present invention. Each entry is stored as a separate field in the header, each with its own unique tag.
Expiration Date
As shown in FIG. 3 , two tags that may be used in the variable-length file header of the present invention include EA (Absolute Expiration) and ER (Relative Expiration). The Absolute Expiration tag sets the date on which the RFQ compressed file will “expire.” That is, when the viewing application loads the file, it compares the expiration date in the file header to the current date. If the current date is after the expiration date in the file header, the file has “expired”, and the viewing application will not display the compressed image. Additionally, in a preferred embodiment, the viewing application will also not print the file once it has expired.
The Relative Expiration date tag works in a similar manner. This tag contains an integer that represents the number of days used to calculate the expiration date of the RFQ compressed file. In one embodiment, the Relative Expiration date calculation requires that the Competitive Bidding Release date (CV) tag also be set. In this embodiment, the Relative Expiration date is calculated by adding the number of days set in the Relative Expiration field to the Competitive Bidding Event Release date. If the current date is after this calculated expiration date, the file has “expired”. In a preferred embodiment, if the Competitive Bidding Event Release date tag is not set, the Relative Expiration Date may be ignored. In alternative embodiments, the expiration date of the file may be calculated by adding the Relative Expiration to other variables, such as a timestamp on another file, or a date stored on the displaying system. There are many alternative methods of calculating an expiration date using a Relative Expiration value that will be obvious to those skilled in the art, and it is intended that the scope of the present invention include these alternatives.
In a preferred embodiment, if the Relative Expiration value is set as well as the Absolute Expiration, the Absolute Expiration takes precedence. That is, if a file has not “expired” according to the Relative Expiration, but has “expired” according to the Absolute Expiration, it is treated as an expired file.
The expiration date fields can be used in a number of ways. For example, the expiration date field can be used to ensure that a user is viewing a current version of a drawing or document. Because drawings and documents are constantly under revision, it is easy for a user to accidentally rely on the information in an out-of-date document or drawing simply because he does not know there is a newer version of the file. If an expiration date corresponding to the expected date of the next revision of a document is stored in the file header, and the viewing application disallows display or printing of the document after this expiration date, the user will be forced to acquire the latest version of the document. There are many other uses for the expiration date fields, as will be obvious to those skilled in the art, and it is intended that these uses come within the scope of the present invention.
Image View State
One of the more common problems associated with image data is that frequently the user must manipulate the image when it is first displayed in order to optimally view the image. For example, the document may be a portrait document, but was scanned in landscape mode, and is therefore rotated 90 degrees when initially displayed by a viewing application. In this example, a user must rotate it back 90 degrees in order to properly view it. As another example, the image of interest to the user may be smaller than the entire scanned area. This results in a very small image surrounded by white space. In this case the user must zoom the image in order to achieve an adequate view state. One of the features of the present invention is the ability to capture a view state that corresponds to a particular viewing configuration, and store this view state in the header of the RFQ compressed file. When the file is subsequently displayed, the view state saved in the header is used by the viewing application to display the compressed image such that a good initial presentation of the image that requires no additional manipulation by the user is displayed. By saving view state information in the header, the image itself is not modified.
This is an important feature in the context of the publication of electronic RFQs. The documents that are used in an electronic RFQ are typically converted to the RFQ compressed format in batch processing. The initial documents may be stored in any orientation, and may have originally been paper documents that were scanned. For any number of reasons, the documents are frequently not stored in an optimal view state. In the present invention, a user can manipulate the image to an optimal view state in an application, then save this view state with the image—without changing the image data itself.
This view state can then be considered the base view state, in that any future fit operations will use this view state rather than the original image. The printing function may also be modified to use this view state to output the image.
The present invention saves a view state in the file header, but does not alter the image data itself. This feature is important because it would take a great deal of effort to re-convert a document in such a manner that it is saved in an optimal view state. This feature allows a user to set the optimal view state, then save it without changing the image data itself. This portion of the header acts as a set of directives to the viewing application to display the image in a certain manner.
The view state data may include rotation, scale, page and x and y offset information, for example. In a preferred embodiment, the view state is saved in the header in the following format:
VS, <page#>, <rotation>, <scale>, <xoff>, <yoff>
In the above format, “VS” is the tag for view state field. The Page # parameter is an integer indicating the page to which the view state applies if the document is a multi-page document. In a preferred embodiment, if the value is set to zero (or some other defined value), the view state is applied to all pages in the file. Rotation is an integer representing the degrees of rotation in the clockwise direction. For example, a value of 90 means that the image should be rotated 90 degrees in the clockwise direction by the viewing application. In a preferred embodiment, valid values for the Rotation parameter may be limited. For example, valid Rotation values may be limited to 0, 90, 180 and 270. Scale is a real number that represents the zoom that viewing application should set for the image. Xoff and Yoff represent the horizontal and vertical offsets from the image origin to which the viewing application should center the image on the display. As will be apparent to one skilled in the art, not all of the above-identified parameters are required when saving view state information. In addition, in alternative embodiments, it may be desirable to add further parameters to the View State field. The parameters itemized above were given by way of example, and are not intended to be limiting.
The viewing application should capable of interpreting this header field and using the data stored in the field to fit the image to the user's display device. If a user is using a version of a viewing application that does not recognize this tag, the viewing application will preferably ignore this field, and display the image in its original state. It is a feature of the present invention that if the viewing application does not recognize a tag in the header, then it can simply ignore that field of the header. In this manner, extra tags should not cause errors, and new tags can be created as needed. The viewing application can updated as needed to recognize and process new tags.
In a preferred embodiment, the viewing application may have an “Original Tool” that can be used to revert the image to its original view state. The information saved in the VS field will be ignored by the viewing application in this case. The Original Tool may have an option to remove all view states, or just revert to the original state on the current page.
FIGS. 5 , 6 and 7 illustrate how a view state can be saved. The image shown in FIG. 5 is the original image. The user clicks on the rotate button, as shown by button 710 , until the image is in its proper orientation, as shown in FIG. 6 . The user then fits the image to fit the display, as shown by button 720 in FIG. 6 . The properly zoomed image is shown in FIG. 7 . The user can then save this view state by clicking on the “Save View” button 730 , shown in FIG. 7 . This causes the application to save the changed rotation and zoom in the file header when the image is converted to the RFQ compressed format.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | A method and system for creating an electronic file to be used in an online auction are described herein. In one embodiment, an exemplary process includes creating a header portion and a data portion of a computer file, where the header portion provides meta-data about data stored in the data portion. The header portion includes multiple header fields. For each header field, a data tag is stored in the header field and the data tag indicates a header field type associated with the respective header field. For each header field, a meta-data item is stored and defined by the data tag, where the meta-data item references to content associated with the meta-data item and stored in the data portion of the computer file. At least one header field contains a meta-data item used by an online auction application to categorize the computer file, such that the content stored in the data portion associated with the meta-data item is presented in a proper form during an online auction, based on information derived from a combination of the data tag and the meta-data item. | 8 |
TECHNICAL FIELD
This invention relates to a connector for use in electrically connecting a ROM or IC card having a computer program stored therein to, for example, a computer equipped apparatus body.
BACKGROUND ART
The ROM card has a packaged construction such that a printed circuit board in which a ROM, with necessary connections, is provided has a contact provided on one side edge thereof, the contact being exposed outside so that when the ROM card is inserted into the connector, the printed circuit board of the ROM card is electrically connected to a main printed circuit board of the apparatus body.
FIG. 8 shows a conventional connector. This connector is of such a construction that as a ROM card 3 is inserted into a card insertion port 2 of a body 1, contacts 6 having a curved shape are outwardly pushed away in a manner as indicated by the arrows, while being held in friction contact with the ROM card 3, the contacts 6 being individually formed as such in respective contactor portions 5 of conductor strips 4 accommodated in the body 1, and that when the ROM card 3 is brought to a set position, the contacts 6 are brought into resilient contact with the contact of the ROM card 3.
Another type of conventional connector, which is shown in FIG. 9, is of such arrangement that in a body 1 there is provided an expansion member 7 such that if it is rotated a given angle (e.g., 90 degree) in one direction so that conductor strips 4 accommodated in the body 1 are outwardly pushed away against the elastic force thereof, the contact of the ROM card 3 is not brought into friction contact with contacts 6 of the conductor strips 5 when the ROM card 3 is inserted into a card insertion port 2; and after the ROM card 3 is brought to its set position, by rotating the expansion member 7 over the given angle in the reverse direction as shown by a virtual line in FIG. 9 the contacts 6 are reset to their original position under the elastic force of respective contactor portions 5 of the conductor strips 4, whereupon the contacts 6 are brought into resilient contact with the contact of the ROM card 3.
In the FIG. 8 connector, however, if the contacts 6 of the conductor strips 4 are allowed to are brought into firm resilient contact with the contact of the ROM card 3 to ensure steady continuity, a larger insertion force is required when the ROM card 3 is inserted, which hampers ease of insertion and, in addition, involves vigorous friction between the contact of the ROM card 3 and the contacts 6 of the conductor strips 4 upon insertion and withdrawal of the ROM card 3, so that the contact or contacts of either side or both sides are likely to be worn out, their performance quality being thus unfavorably affected. On the other hand, if the preload of contactor portions 5 of the conductor strips 4 is reduced in an attempt to prevent such quality deterioration, it is likely that the contact pressure between the respective contacts will be excessively reduced, with the result of poor continuity. In the FIG. 8 connector, therefore, in order to minimize possible quality deterioration of the contacts and to provide good continuity, not only is it necessary to properly design the preload for the contactor portions 5, but also it is necessary to construct the conductor strips 4 of a costly high-performance spring material and further to upgrade the deposit thickness of the contacts 6; all this naturally leads to increaded cost of manufacture. Another problem is that since the ROM card 3 is placed outside the connector when not in use and since it is subject to frequent insertion and withdrawal, it is very likely to contact quality deterioration even if aforesaid measures are taken.
Whilst, in the FIG. 9 connector, if the contactor portions 5 of the conductor strips 4 are outwardly pushed away by the expansion member 7, the contact of the ROM card 3, upon each insertion or withdrawal, is unlikely to rub against the contacts 6 of the conductor strips 4, and therefore it is possible to provide a larger preload for the conductor strips 4 to ensure steady continuity; thus, such quality deterioration due to contact wearing as above mentioned is inhibited. However, this connector requires, as its indispensable components, the expansion member 7 and various parts for controlling same, and this makes the arrangement complicated. Further, for each insertion or withdrawal of the ROM card 3, the expansion member 7 has to be controlled, which is very troublesome.
The foregoing is also true in the case of an IC card being used instead of the ROM card.
SUMMARY OF THE INVENTION
Therefore, this invention is intended to overcome aforesaid difficulties and has as its primary object the provision of a connector which is easy to control and is less liable to deterioration of contact quality, by adoption of such arrangement that respective contactor portions of conductor strips are designed to be displaced in conjunction with the insertion or withdrawal of a ROM card.
In order to accomplish the foregoing object, the present invention provides a connector comprising:
a body having an insertion port for a contact-loaded card, a support portion provided in the interior of the body for engagement with conductor strips at their middle portions, a movable member provided in the interior which is slidable back and forth along a path for insertion and withdrawal of the card, there being disposed, between the movable member and the body, spring elements for constantly biasing the movable member in the forward direction thereof and lock mechanisms for positioning the movable member at a retreated position and at an advanced position,
the conductor strips each having a contactor portion positioned forwardly of its portion in engagement with the support portion and disposed along the insertion and withdrawal path, the contactor portion having at the middle thereof a contact to be engaged by and disengaged from the contact of the card,
the movable member having a stepped portion for abutment with the front end of the card when the card is inserted through the insertion port, and a cam face which raises the respective front ends of the contactor portions against their elastic force so as to enable the contacts of the contractor portions to move away from the contact of the card when the movable member is at its advanced position and which allows the front ends of the contactor portions to be reset under the elastic force thereof so as to enable the contacts of the contactor portions to go in contact with the contact of the card when the movable member is at its retreated position,
the lock mechanisms being alternately switchable to a locked state in which the movable member is held at the retreated position and an unlocked state in which the movable member is allowed to slide from the retreated position to the advanced position, through repetition of push-in movement of the card brought in abutment with the stepped portion.
Therefore, according to such arrangement, when the card which is inserted through the insertion port of the body until its front end abuts the stepped portion of the movable member is further pushed in, the movable member is caused to retract to the retreated position against the biasing force of the spring elements, whereupon the lock mechanisms are switched over to the locked state so that the movable member is positioned at the retreated position. Through such a series of card insertion movement, the contacts of the conductor strips which have been held away from the contact of the card by the action of the cam face of the movable member are brought in resilient contact with the contact of the card only when the card is pushed in to the set position.
When the card at the set position is pushed in, the lock mechanisms are switched over to the unlocked state, and the movable member is caused to slide to the advanced position under the biasing force of the spring elements, whereupon the card is pushed out by the movable member. During this push-out movement, the contacts of the conductor strips are held away from the contact of the card by the action of the cam face.
According to the connector of the invention, therefore, the contacts of the conductor strips can be moved away from and into contact with the contact of the card by insertion and withdrawal of the card, without any particular control of the movable member. Thus, no troublesome control is required and greater ease of use can be obtained. Further, according to the invention, the contactor portions of the conductor strips which are disposed along the path for card insertion and withdrawal are resiliently displaced and reset at their front ends by the action of the cam face of the movable member, and therefore the contactor portions can be resiliently displaced and reset in smooth and reasonable manner. Therefore, the biasing force of the spring elements for biasing the movable member in its forward direction can be of a small magnitude, and thus ease of card insertion operation can be well assured.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1, is a partial cutaway exploded view in perspective of a connector according to one embodiment of the present invention;
FIG. 2, is a cross sectional view showing an internal aspect of the connector;
FIG. 3, is a cross sectional view taken along line III--III in FIG. 2;
FIG. 4, is a cross sectional view taken along line IV--IV in FIG. 2;
FIGS. 5A-5D, are subassembly views illustrating the operation of the slider of the present invention;
FIGS. 6A-6C, are detail views illustrating the operation of the lock mechanism of the present invention;
FIG. 7, is a section view taken along line VII--VII in FIG. 6A;
FIG. 8 is a cross sectional view of a prior art arrangement; and
FIG. 9 is a cross sectional view of another prior art arrangement.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The connector shown in FIGS. 1 and 2 is of a simplified assembly design and incorporates a special feature intended for preventing a plurality of conductor strips from going into contact with one another.
A body 10 of the connector consists of a combination of an outer body 11 and an inner body 12, both being of plastic molding. The inner body 12 has at its front end a support portion 14 by which conductor strips 13 are engaged at their middle portion, and also has a plurality of ribs 15 disposed in equi-spaced relation in the widthwise direction, the ribs 15 being present over an area covering the upper and lower surfaces of a protruding portion 16 of the inner body 12 through the rear end thereof. At the underside of the protruding portion 16 of the inner body 12 there are formed a recess 17 which is open at the under side and a recessed portion 18 which is open at the front. Further, at a lower portion of the rear end of the inner body 12 there are formed vertical grooves 19a, 19b of two different depths arranged at alternate intervals, and at sides of the inner body 12 there are provided projections 20 and pawls 21.
The outer body 11, being of a hollow box shape, has at its front side an insertion port 22 for insertion of a ROM card. The outer body 11 also has groove portions 23 into which the projections 20 of the inner body 12 are to be fitted, engagement grooves 24 for engagement with the pawls 21, and mounting grooves 26 for mounting lock mechanism components 25 which will be described hereinafter.
Numeral 27 designates a movable member (hereinafter referred to as "slider"). At its front end the slider 27 is formed with a stepped portion 28 for abutment with the front end of the ROM card, the upper surface of the stepped portion is formed as a cam face 29. As FIG. 2 illustrates in detail, the cam face 29 consists of a first flat surface 30, a second flat surface 31, the two surfaces being different in level, and a sloped guide surface 32 continued to the first flat surface 30. The first flat surface 30 is longer than the second flat surface 31 in the longitudinal direction, and it is partitioned by a multiplicity of ribs 15. On each side of the movable member 27 there is provided a laterally extending spring seat 34 for seating a spring element 33 comprised of a coil spring, there being provided a support pin 35 on the spring seat 34 integrally therewith. Shown by 36 is a flange for mounting the connector to a computer-equipped apparatus body.
Each of the conductor strips 13 is comprised of an elongate metal leaf and includes a contactor portion 37 located more adjacent to its front end than its portion for engagement with the support portion 14, the contactor portion 37 being bent in a check-mark pattern at its mid-portion to provide a contact 38. The front end of the contactor portion 37 is crooked to form a follower portion 39 corresponding to the cam face 29. As FIG. 1 shows, in their pre-assembly state, the conductor strips 13 are in such form that a multiplicity of them are connected to one another by tie bars 40. Each contactor portion 37 is bent at an angle close to a right angle to a lead portion 41. The lead portion 41 is formed with triangular projections 42 at given locations thereon.
The lock mechanisms 25 each consists of a pin 43, a mounting frame 44 fixed to a bottom wall of the outer body 11 for rotatably supporting the pin at one end thereof, a spring 45, and a guide groove 46 formed on the underside of the slider 27. The construction of the guide groove 46 will be further described hereinafter.
The above mentioned outer body 11, inner body 12, slider 27, and the lock mechanisms 25 are assembled together as illustrated in FIG. 2. In their assembled condition, the inner body 12 is fitted in the outer body 11, with the slider 27 fitted in the recessed portion 18 of the inner body 12 so that it is slidable back and forth along the insertion/withdrawal path (shown by numeral 51) for ROM card 50. The front end of pin 43 of each lock mechanism is fitted in the guide groove 46, the pin 43 being constantly urged inwardly of the guide groove 46 by the spring 45. As FIG. 4 shows, the spring elements 33 each is interposed between the corresponding spring seat 34 of the slider 27 and the corresponding projection 20 of the inner body 12 so that it is constantly urging the slider in the forward direction thereof, i.e., toward the insertion port 22. The conductor strips 13 are individually fitted between corresponding adjacent ribs 15, 15 of the inner body 12, their respective contact portions 37 being bent so as for them to wrap around the protrudent portion 16 of the inner body 12 so that they extend along the insertion/withdrawal path 51 for ROM card 50. As shown in detail in FIG. 3, the projections 42 of each conductor strip 13 bite into adjacent ribs 15, thus serving to fix the lead portion 41 to the inner body 12 firmly and without looseness.
The guide groove 46 of each lock mechanism 25 will be explained with reference to FIGS. 6A-6C and 7. This guide groove 46 has a heart-shaped engagement portion 47, V-shaped guide faces 48a, 48b, and stepped portions 49a, 49b, 49c, 49d formed at four locations. By virtue of these stepped portions 49a, 49b, 49c, 49d, the pin 43 is guided in the specific direction only, being inhibited from relative movement in the reverse direction.
Next, the function of the above described connector will be explained.
As FIG. 5A shows, when ROM card 50 is not inserted, the slider 27 has been pushed forward to the advanced position under the biasing force of the spring elements 33. Accordingly, the follower portion 39 of each conductor strip 13 follows the first flat portion 30 of the cam face 29 so that the contactor portion 37 is positioned on the flat portion 30 level. When the contactor portion 37 is in such raised position, the contact 38 of the conductor strip 13 is retreated to a location outside the insertion/withdrawal path 51 for ROM card 50. Therefore, upon insertion of ROM card 50, there is no rubbing contact between aforesaid contact 38 and the contact of the ROM card 50.
After the ROM card 50 is inserted into the insertion port 22 of the body 1 so that its front end comes into abutment with the stepped portion 28 of the slider 27, if the ROM card 50 is pushed further in as FIGS. 5B and 2 illustrate, the slider 27 retreats against the biasing force of the spring elements 33 to the retreated position, while the follower portion 39, just before the slider 27 reaches its retreated position, is displaced from the first flat portion 30 to a position on the second flat portion 31, whereupon the contact portion 37 makes entry into the insertion/withdrawal path 51. At this point of time, therefore, the contact 38 of the conductor 13 is brought into resilient contact with the contact of the ROM card 50. Thus, when the ROM card 50 pushes the slider 27 to the retreated position, the contact 38 of the conductor strip 13 is rubbed against the contact of the ROM card 50 while the ROM card 50 is pushed from a position immediately prior to the set position and to the set position. In this case, the mutual rubbing between the contacts serves for the purpose of the so-called self cleaning of contacts; indeed, such rubbing is convenient from the standpoint of good contact quality maintenance.
Meanwhile, through the above described series of ROM card insertion operation, the guide groove 46 of each lock mechanism 25 is displaced from the FIG. 6A position to the FIG. 6B position in relation to the pin 43, and the engagement portion 47 is brought into engagement with the pin 43 under the biasing force of the spring element 33 so that the lock mechanism is switched over to the lock state, the slider 27 being thus positioned in the retreated position. The ROM card 50 is set to the set position.
When the ROM card 50 in the set position as in FIG. 5C, is pushed in to further retreat the slider 27, the guide groove 46 of each lock mechanism 25 is displaced further rearward as FIG. 6C shows, so that the pin 43 is disengaged from the engagement portion 47, the lock mechanism being thus changed over to the unlocked state. Accordingly, the slider 27 is caused to slide from the retreated position to the advanced position under the biasing force of the spring element 33, and thus the ROM card 50 is pushed outward as FIG. 5D shows. In the meantime, the guide groove 46 of the lock mechanism 25 is reset from the FIG. 6C position to the FIG. 6A position, and the slider 27 is positioned to the advanced position. Following the slide movement of the slider 27, the follower portion 39 of each conductor strip 13 is guided by the guide face 32 to get on the first flat portion 30 and the contactor portion 37 is pushed against the elastic force thereof outwardly of the insertion/withdrawal path. During the course of the ROM card 50 being pushed in at the set position and up to the follower portion 39 being raised to the first flat portion 30, the contact of the ROM card 50 is rubbed by the contact of the conductor strips 13; but in the course of the operation subsequent to the time when the follower portion 39 is raised to the first flat portion 30, the contact 38 is held away from the contact of the ROM card 50. It is to be noted in this conjunction that the rubbing contact between the contacts at the initial stage in which the ROM card 50 is pushed out, as mentioned above, serves for the aforesaid self-cleaning purposes; such rubbing is desirable from the standpoint of good contact quality maintenance.
In the above described connector, the displacement of the contact portions 37, which takes place in conjunction with the slide movement of the slider 27, is effected as a pivotal movement about the engagement position of the conductor strips 13 relative to the support portion 14 of the inner body 12 or a position adjacent thereto. The follower portion 39 of each conductor strip 13 is provided at a location which is more remote from the pivotal position than the contact 38. Therefore, even if the preload of the contactor portions 37 is increased in order to allow the contacts 38 to move into more forceful resilient contact with the contact of the ROM card 50, the slide movement of the slider 27 can be effected with comparatively small force. From this it is apparent that if the spring force (biasing force) of the spring elements 33 is decreased, it is still possible to cause the slider 27 to be pushed forward steadily from the retreated position to the advanced position under the biasing force. In this way, the force for insertion of ROM card 50 can be set to a minimum.
The foregoing description is equally applicable to the case where an IC card is used instead of the ROM card 50.
As described above, even if a greater preload is applied to the contactor portions of the conductor strips, any contact wearing due to rubbing of contacts is less likely to occur, and thus the quality of contacts can be long maintained in good condition. Further, as compared with the conventional arrangement shown in FIG. 9, the invention has the advantage that such troublesome procedure as previously required is eliminated, it being thus possible to provide a connector which is easy to use and inexpensive to manufacture. Another advantage is that even if contacts are caused to go in more forceful resilient contact in order to ensure steady continuity, the force required for insertion of a card can be of a minimum magnitude. Therefore, when the invention is applied to a connector having a large number of contacts, ease of use can be greatly enhanced, because the force required for card insertion can be relatively small for the number of contacts involved.
INDUSTRAL APPLICABILITY
As above stated, the connector according to the invention is advantageously applicable for use in electrically connecting cards, such as a ROM card and an IC card, which are subject to frequent insertion and withdrawal, to a main printed circuit board of an electric apparatus. | The invention relates to a connector for use in electrically connecting a ROM or IC card, or the like card to a main printed circuit board of an apparatus. In the connector, a movable member is mounted which causes a contact of the card to be resiliently contacted by a contact of a contactor portion connected to the main printed circuit board when the card is inserted a specified degree, and which causes the contact of the contactor portion to move away from the card a distance greater than the thickness of the card when the card is withdrawn. This arrangement involves no troublesome operation in connection with the expansion and contraction control of the contactor portion and can effectively prevent possible wear and deterioration of the contacts. | 7 |
BACKGROUND OF THE INVENTION
The present invention is directed to a control panel, for an image forming device, whose position can be adjusted.
Such a control panel facilitates the use of the panel, for example, by a user in a standing position, and a user in a wheel chair.
A known and conventional position adjusting mechanism for a control panel has a position holding mechanism having a fixed member in the form of a bracket with a number of holes for a pin. The mechanism also has a movable member in the form of an engaging pin that can be inserted into one of the holes. As an operating member of the position holding mechanism is operated in an operating direction, the pin (movable member) is moved in a direction substantially perpendicular to the direction the operating member is operated, until the pin is inserted into one of the holes provided to the main body, whereby fixing the control panel in one position (See, for example, Publication 2003-246114 of Japanese Patent Application). Since the direction in which the pin (the movable member) moves is substantially perpendicular to the direction in which the operating member is moved in the conventional device disclosed in the patent document described above, there is room for improvement in that the conventional device required a mechanism to convert the direction of the operation into the perpendicular direction in which the pin needs to be moved.
SUMMARY OF THE INVENTION
The present invention was made to address this issue. The object of the invention is to provide a control panel improved over the conventional one.
To achieve this object, the control panel, in accordance with the present invention, which is adapted to be attached to a main body of an image forming device, and which has a plurality of positions with respect to the image forming device main body, comprises: a panel main body; a fixed member adapted to be fixed relative to the main body of the image forming device; a movable member movable between a first position wherein the movable member engages the fixed member to maintain the panel main body in a selected one of the plurality of positions and a second position, spaced from the first position in a first direction, wherein the movable member disengages the fixed member to allow movement of the panel main body; a control member operatively connected to the movable member and movable substantially in the first direction to move the movable member between the first position and the second position.
It is thus possible to provide a control panel without a direction converting mechanism that was necessary in the conventional device. This has additional advantage of alleviating the loss of operating force that occurred when changing the operating direction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of a copier as an example of an image forming device in accordance with the present invention,
FIG. 2 shows a perspective view of; a part of the control panel in accordance with the present invention,
FIG. 3 shows a plan view of the part of the control panel shown in FIG. 2 ,
FIG. 4 shows a side view of the control panel,
FIG. 5 shows a side view of the control panel,
FIG. 6 shows a side view of the control panel,
FIG. 7 shows a side view of an engaging area of the control panel in accordance with a different embodiment of the present invention,
FIG. 8 shows a side view of an engaging area of the control panel in accordance with a further embodiment of the present invention,
FIG. 9 shows a side view of an engaging area of the control panel in accordance with a further embodiment of the present invention,
FIG. 10 shows a side view of an engaging area of the control panel in accordance with a further embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Embodiments of the control panel of an image forming device with a position adjusting mechanism is described next with reference to the accompanying drawings. The word “pin” used throughout the present specification means a member that is able to engage with another object. A “pin” does not have to have a circular cross section and may have, for example, a polygonal, elliptic, or an irregularly shaped cross section if appropriate. In addition, a “pin” does not have to have a small diameter.
Examples of an image forming device includes, but not limited to, a photo copier, a printer, and a facsimile machine. While a photo copier is used in the present specification as an example of an image forming device, the present invention is applicable to any image forming devices. In the present specification, “front”, “forward”, or other similar word is associated with the direction indicated by the arrow F in FIG. 1 and “back”, “rear” or other similar word is associated with the direction opposite to the direction indicated by the arrow F.
As shown in FIG. 1 , the a control panel 2 is positioned at a front and upper position of the main body 1 of the photo copier (sometimes referred simply to as a copier). As shown in FIGS. 2 to 4 , the control panel 2 includes a panel main body 2 a and a panel cover 2 b attached to the upper surface of the panel main body 2 a . Various control keys 3 , such as a numeric pad, are provided on the panel cover 2 b , i.e. the top surface of the control panel 2 . In addition to the control keys 3 , a liquid crystal display 4 is provided on the panel cover 2 b in the present embodiment as shown in FIG. 1 to display various information. Various parts of the control panel 2 including the panel main body 2 a and the panel cover 2 b may be made of resin, with the exception of the urging springs described below. However, a part or the whole of each of these members may be made of metal.
A pair of forwardly projecting brackets 5 are fixed to the front surface of the main body 1 of the copier at locations that face the back of the control panel 2 . Each of the brackets 5 has a pair of plate members 5 a and 5 b . A horizontally oriented lateral shaft 6 extends through the plate members 5 a and 5 b . Each lateral shaft 6 has a projecting portion that projects inwardly through the plate member 5 b which is located more inwardly than the other plate member 5 a . The panel main body 2 a of the control panel 2 is mounted to the projecting portion through a vertical member 2 c of the main body 2 a . The lateral shaft 6 may be fixed to the panel main body 2 a.
More specifically, the control panel 2 is mounted to the main body 1 of the copier such that it is rotatable about the lateral axis L 1 of the lateral shaft 6 with respect to the main body 1 , so that the angular position of the control panel 2 may be adjusted about the lateral axis L 1 . The control panel 2 is also urged by the coil springs 7 wound around the two lateral shafts 6 such that the front part of the control panel 2 is urged upwardly about the lateral axis L 1 .
A control member 8 a is located on the upper surface of the panel main body 2 a . The control member 8 a is adapted to be movable in the operating direction shown at the arrow A in FIGS. 2 and 3 by means of the slide mechanism 13 that includes a pair of right and left slide pins 13 a that project upwardly from the panel main body 2 a and corresponding elongate slots 13 b formed in the control member 8 a . The operating direction is substantially horizontal in the present embodiment and is oriented toward the lateral axis L 1 . However, the operating direction of the present invention is not limited to this direction. A control lever 8 b is mounted to the front part of the control member 8 a so that the lever 8 b can be rotated through a predetermined angle about the axis L 2 which is substantially parallel to the lateral axis L 1 . The control member 8 a is urged toward the copier main body 1 by means of a pair of the right and left coil springs 9 disposed between the control member 8 a and the panel main body 2 a.
Each of the right and left plate members 5 b that project forwardly from the copier main body 1 has two pins 10 a and 10 b that project inwardly and extend substantially parallel to the lateral axis L 1 . The pins 10 a and 10 b function as a fixed member. A movable member 11 is integral with the control member 8 a near right and left end positions of the control member 8 a . The movable member 11 extends generally vertically and also in the forward-rearward direction. The movable member 11 has a pair of fingers 11 b , 11 c that generally extend in the forward-rearward direction and a recess 11 a formed therebetween and facing one of the pins 10 a and 10 b . The movable member 11 with the fingers 11 b , 11 c and the recess 11 a together with the pins 10 a and 10 b form the position holding mechanism 12 . The recess 11 a extends substantially horizontally and opens toward the lateral axis L 1 . The recess 11 a has an upper edge that extends substantially horizontally and a lower edge that extends parallel to the upper edge. Each of the fingers 11 b , 11 c has a guide surface 11 d or 11 e for guiding the pin 10 a or 10 b to the recess 11 a . The vertical height of each of the fingers 11 b , 11 c is slightly less than the distance between the two pins 10 a and 10 b . The vertical height of the recess 11 a , that is, the spacing between the fingers 11 b and 11 c , is slightly greater than but substantially equal to the diameter of the pin 10 a or 10 b.
The control member 8 a and the control lever 8 b forms the control portion 8 of the position holding mechanism. More particularly, the movable member 11 with the recess 11 a is adapted to move closer to or away from the copier main body 1 along the operating direction A. As the movable member 11 is moved toward the main body 1 by operating the operating member 8 , the recess 11 a engages either one of the two pins 10 a and 10 b in a direction substantially perpendicular to the direction the axis of either of the pins 10 a and 10 b extends. The angular position of the control panel 2 is thus maintained by the engagement of the pin 10 a or 10 b and the movable member 11 .
To reverse the process, the movable member 11 is moved away from the copier main body 1 so that the pin 10 a or 10 b is no longer held in the recess 11 a . Thus the recess 11 a disengages the pin 10 a or 10 b , resulting in the release of the control panel 2 from the angular position.
A slot 2 d is formed in each of the vertical members 2 c of the panel main body 2 a . The slot 2 d generally forms an arc about the axis of the lateral shaft 6 and extends generally vertically. A horizontally extending projection 5 c is formed in the plate member 5 b at the position corresponding to the slot 2 d for engaging the slot 2 d . The projection 5 c abuts against the lower end of the slot 2 d when the control panel 2 is in the first angular position as shown in FIG. 4 , whereas the projection 5 c abuts against the upper end of the slot 2 d when the control panel 2 is in the second angular position as shown in FIG. 6 . Thus, the first and second angular positions are set by the abutment of the projection 5 c against the lower end and the upper end of the slot 2 d respectively.
The operation of the position adjusting mechanism of the control panel is described next.
To move the control panel 2 from its first angular position shown in FIG. 4 to its second angular position shown in FIG. 6 , for example, the operator rotates the control lever 8 b through a predetermined angle as shown in FIG. 5 and continues to pull it forward against the urging force of the coil springs 9 . The control member 8 a and the movable member 11 are then also moved away from the copier main body 1 with the control lever 8 b along the operating direction A so that the upper pin 10 a is no longer held in the recess 11 a , thus releasing the control panel 2 from the angular position.
The control panel 2 is then rotated downwardly about the lateral axis L 1 . Subsequently, the operator releases the control lever 8 a . This allows the control member 8 a and the movable member 11 to be moved toward the copier main body 1 along the operating direction A by the urging force of the coil springs 9 . The lower pin 10 b then comes to be held in the recess 11 a of the movable member 11 , thus holding the control panel 2 in its second angular position as shown in FIG. 6 .
Moving the control panel 2 from the second angular position shown in FIG. 6 to the first angular position shown in FIG. 4 is accomplished in a similar manner. The control lever 8 b is pulled forwardly. However, because of the urging force of the springs 7 that urges the front part of the control panel 2 upwardly, the panel 2 is moved upwardly automatically and is stopped at the appropriate position. Thus, the control panel 2 does not have to be pushed up. Thus all the operator has to do is to release the control lever 8 b . The movable member 11 is then moved toward the copier main body 1 by the urging force of the coil springs 9 until the upper pin 10 a comes to be held in the recess 11 a of the movable member 11 , thus holding the control panel 2 in the angular position shown in FIG. 4 .
The mechanism described above allows the control panel 2 to be held or maintained in two angular positions. However, it is, of course, possible to hold the control panel 2 at three or more positions by increasing the number of the pins correspondingly.
Since the pin 10 a or 10 b is firmly held in the recess 11 a of the movable member 11 by the abutment of the upper and lower edges of the pin 10 a or 10 b against the recess 11 a in any of the angular positions, the control member 2 is securely maintained at a desired angular position.
OTHER EMBODIMENTS
(1) As shown in FIG. 7 , it is possible to define a plurality of angular positions of the control panel 2 by providing a corresponding number of recesses 21 a and 21 b and a single pin 20 . While the movable member 21 of this embodiment has two recesses, it is possible to provide three or more recesses as necessary. The fingers 21 c , 21 e , 21 h have guide surfaces 21 d , 21 f , 21 g , 21 i.
(2) In the first embodiment, the position maintaining mechanism includes the pins 10 a and 10 b as well as the movable member 11 having a recess 11 a , with the pins 10 a and 10 b provided to the member on the copier main body 1 side and the recess 11 a formed in the control member 8 of the position maintaining mechanism. However, as shown in FIG. 8 , a plurality of recesses 32 a , 32 b , 32 c may be formed in the bracket (main body 1 side) while the single engaging pin 30 may be provided to the movable member 31 . It is also possible to form one recess in the bracket and to provide a plurality of pins in the movable member.
The position maintaining mechanism does not have to be a pin and recess arrangement. Various other arrangement may be used in such a mechanism utilizing mutually engaging members.
For example, FIG. 9 shows a movable member 41 having an engaging portion with sloped surfaces and a fixed member 5 b having correspondingly shaped engaged portions having sloped surfaces. FIG. 10 shows a movable member 51 having an engaging portion with a round surface and a fixed member 5 b having correspondingly shaped engaged portions. It is possible to provide the fixed member with the engaging portion while providing the movable member with the engaged portions. A movable member and fixed members may have engaging surfaces that are shaped differently than the ones shown above.
(3) While the operating portion 8 of the position maintaining mechanism is provided on the control panel 2 in the previous embodiments, the operating portion 8 may be mounted to the copier main body 1 . In addition, while the movable member 11 is provided integrally with the control portion 8 in the embodiments described above, another member or members may be placed between the control portion 8 and the movable member 11 .
(4) On bracket and one lateral shaft may be used to rotatably support the control panel 2 instead of a pair of brackets 5 and a pair of lateral shafts 6 . | A control panel adapted to be attached to a main body of an image forming device is disclosed. The control panel has a plurality of positions with respect to the image forming device main body and comprises: a panel main body; a fixed member adapted to be fixed relative to the main body of the image forming device; a movable member movable between a first position wherein the movable member engages the fixed member to maintain the panel main body in a selected one of the plurality of positions and a second position, spaced from the first position in a first direction, wherein the movable member disengages the fixed member to allow movement of the panel main body; a control member operatively connected to the movable member and movable substantially in the first direction to move the movable member between the first position and the second position. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to methods of polishing intraocular lenses. More specifically, the present invention relates to methods of dry polishing intraocular lenses in a fluidized bed of particles to remove flash, surface irregularities and/or sharp edges from molded or lathe cut surfaces thereof.
BACKGROUND OF THE INVENTION
[0002] Methods of molding articles from moldable materials have been known for some time. A common problem associated with molding techniques is the formation of excess material or flash on the edges of the molded article. Depending on the type of article formed in the molding process and the manner in which the article is used, the presence of excess material or flash can be undesirable. The same is also true of rough, irregular or sharp edges found on articles produced through a lathing process.
[0003] Many medical devices, such as for example intraocular lens implants, require highly polished surfaces free of sharp edges or surface irregularities. In the case of intraocular lenses (IOLs), the lens is in direct contact with delicate eye tissues. Any rough or non-smooth surface on an IOL may cause irritation or abrading of tissue or other similar trauma to the eye. It has been found that even small irregularities can cause irritation to delicate eye tissues.
[0004] Various methods of polishing are known in the art. U.S. Pat. Nos. 2,084,427 and 2,387,034 disclose methods of making plastic articles such as buttons that include tumbling the articles to remove projections of excess material or flash.
[0005] U.S. Pat. No. 2,380,653 discloses a cold temperature tumbling process to remove flash from a molded article. This method requires the article to be tumbled in a rotatable container of dry ice and small objects such as wooden pegs. The cold temperature resulting from the dry ice renders the flash material relatively brittle, such that the flash is more easily broken from the article during the tumbling process.
[0006] U.S. Pat. No. 3,030,746 discloses a grinding and polishing method for optical glass, including glass lenses. The method includes tumbling the glass articles in a composition of liquid, abrasive and small pellets or media. The liquid is disclosed as being water, glycerins, kerosene, light mineral oil and other organic liquids either alone or in combination. The abrasive component is described as being garnet, corundum, boron carbide, cortz, aluminum oxide, emery or silicon carbide. The media is disclosed as being ceramic cones, plastic slugs, plastic molding, powder, limestone, synthetic aluminum oxide chips, maple shoe pegs, soft steel diagonals, felt, leather, corn cobs, cork or waxes.
[0007] U.S. Pat. No. 4,485,061 discloses a method of processing plastic filaments which includes abrasive tumbling to remove excess material.
[0008] U.S. Pat. Nos. 4,541,206 and 4,580,371 disclose a lens holder or fixture used for holding a lens in a process of rounding the edge thereof. The process includes an abrasive tumbling step.
[0009] U.S. Pat. No. 5,133,159 discloses a method of tumble polishing silicone articles in a receptacle charged with a mixture of non-abrasive polishing beads and a solvent which is agitated to remove surface irregularities from the articles.
[0010] U.S. Pat. No. 5,571,558 discloses a tumbling process for removing flash from a molded IOL by applying a layer of aluminum oxide on a plurality of beads, placing the coated beads, alcohol, water and silicone IOLs in a container and tumbling the same to remove flash.
[0011] U.S. Pat. No. 5,725,811 discloses a process for removing flash from molded IOLs including tumbling the IOLs in a tumbling media of 0.5 mm diameter glass beads and 1.0 mm diameter glass beads, alcohol and water.
[0012] Prior methods of removing flash or surface irregularities, such as described above, may be inadequate or impractical in the manufacture of certain types of IOLs. For example, certain IOLs formed from relatively soft, highly flexible material, such as silicone, are susceptible to chemical and/or physical changes when subjected to cold temperatures. For this reason, certain types of cryo-tumbling or cold temperature tumbling may be impractical in the manufacture of IOLs made from such materials. Additionally, certain types of abrasive tumbling processes may be suitable for harder lens material, such as glass or polymethylmethacrylate (PMMA), but may not be suitable for softer lens materials. Also, most tumbling processes known in the art require the lens to be submersed in a liquid that may not be suitable for some lens materials or manufacturing processes. Accordingly, a need exists for a suitable process for removing flash and/or irregularities from molded or lathe cut IOLs made of various materials.
SUMMARY OF THE INVENTION
[0013] The present invention relates to methods for dry polishing IOLs. IOLs are currently either molded in removable molds or lathe cut. Subsequent to these operations, the IOLs have surface roughness or sharp edges that need to be minimized or eliminated. After polishing methods such as tumbling the IOLs in a container with glass beads and a liquid, the IOLs must be dried or in the case of hydrogels dehydrated, prior to further processing. Drying or dehydrating the IOLs can be both expensive and time consuming. The dry polishing methods of the present invention eliminate the need for drying or dehydrating IOLs. This is particularly important in the case of surface coated IOLs where a coating or surface treatment can not be consistently applied in the presence of moisture.
[0014] The first method of dry polishing IOLs in accordance with the present invention consists of obtaining a polishing chamber having two opposed open ends, placing glass-spun wool in each open end and polishing material and IOLs in the center. Air, or any other inert gas or gases, is then passed into one end of the polishing chamber and out of the other end while the length of the polishing chamber is preferably maintained in a vertical position. The flow of air keeps the IOLs and polishing material buoyant resulting in dry polished IOLs. After polishing the IOLs, the IOLs are removed from the polishing chamber and polishing material with the use of a sieve. The IOLs are then easily handled and surface treated at this stage without having to dry the same.
[0015] The second and third methods of dry polishing IOLs in accordance with the present invention consist of obtaining an IOL container with one or more optic clamps or flexible optic loops extending from one or more but preferably one rigid arm members. One IOL is placed in each open hinged optic clamps or flexible optic loops of the IOL container so that the IOLs' haptics extend from slots formed in the optic clamps or flexible optic loops. In the case of the optic clamps, once an IOL is positioned therein, the open hinge of the optic clamp is snapped close to secure the IOL in place. The optic clamps when closed only contact the outer peripheral edges of the IOLs positioned therein. Alternatively, the flexible optic loops are designed such that one IOL snaps or slips into position within each flexible optic loop thereof leaving all but the IOL optic peripheral edges exposed. The IOL container with IOLs positioned therein is then snapped into place within a polishing chamber using retention means formed therein. The polishing chamber and the axially concentric IOL tube are then preferably maintained in a horizontal position. The retention means inside the polishing chamber removably fixes the IOL container within the polishing chamber to prevent rotation of the IOL container within the polishing chamber. A dry polishing medium is placed inside the polishing chamber and the one or more open ends thereof removably sealed. The polishing chamber is then axially rotated. As the polishing chamber is rotated, the polishing medium repeatedly contacts the exposed IOL surfaces thus polishing the same. The duration of tumbling and the revolutions per minute of the polishing chamber can be adjusted to achieve the desired degree of polishing. Since the slots of the IOL container protect the IOL optic peripheral edges, the IOL optic peripheral edges remain sharp while the remainder are polished. Following polishing, the IOLs are removed from the IOL container. The polished IOLs are then easily handled and surface treated without having to dehydrate or dry the same.
[0016] The fourth method of dry polishing IOLs in accordance with the present invention involves placing IOLs and dry polishing medium within a polishing chamber so that the IOLs are evenly dispersed throughout. The polishing chamber is then removably sealed and placed on a tumbler and tumbled at a specified speed for a specified period of time. As the polishing chamber tumbles, the dry polishing medium repeatedly contacts the IOL surfaces thereby polishing the same.
[0017] Accordingly, it is an object of the present invention to provide a method for dry polishing lathe cut IOLs.
[0018] Another object of the present invention is to provide a method for dry polishing molded IOLs.
[0019] Another object of the present invention is to provide a method for polishing IOLs without the use of liquids.
[0020] Another object of the present invention is to provide a method for polishing IOLs that eliminates the need to dry or dehydrate the same prior to further processing.
[0021] Another object of the present invention is to provide a method for dry polishing IOLs that is suitable for a variety of IOL materials.
[0022] Still another object of the present invention is to provide a method for polishing IOLs that allows for consistent surface coating without additional process steps.
[0023] These and other objectives and advantages of the present invention, some of which are specifically described and others that are not, will become apparent from the detailed description, drawings and claims that follow, wherein like features are designated by like numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 is a plan view of an intraocular lens with open haptics;
[0025] [0025]FIG. 2 is a plan view of an intraocular lens with looped haptics;
[0026] [0026]FIG. 3 is a plan view of a polishing chamber of the present invention;
[0027] [0027]FIG. 4 is a plan view of the polishing chamber of FIG. 3 connected to an air source;
[0028] [0028]FIG. 5 is a plan view of the polishing chamber of FIG. 4 after loading;
[0029] [0029]FIG. 6 is a perspective view of the IOL container of the present invention;
[0030] [0030]FIG. 7 is a perspective view of the IOL container of FIG. 6 with IOLs loaded therein;
[0031] [0031]FIG. 8 is a plan view of the polishing chamber of FIG. 3 with the IOL container of FIG. 7 removably fixed therein;
[0032] [0032]FIG. 9 is a perspective view of a second embodiment of the IOL container of the present invention;
[0033] [0033]FIG. 10 is a perspective view of the IOL container of FIG. 9 with IOLs loaded therein; and
[0034] [0034]FIG. 11 is a plan view of the polishing chamber of FIG. 3 with the IOL container of FIG. 10 removably fixed therein.
DETAILED DESCRIPTION OF THE INVENTION
[0035] [0035]FIGS. 1 and 2 illustrate typical intraocular lenses (IOLs) 10 produced using dry polishing methods of the present invention. Each IOL 10 typically has an optic portion 12 defined by an outer peripheral edge 18 and one or more but typically two to four haptics 14 of either an open configuration 21 as illustrated in FIG. 1 or a looped configuration 23 as illustrated in FIG. 2. The haptics 14 are integrally formed on outer peripheral edge 18 or permanently attached thereto through processes such as heat, physical staking and/or chemical bonding. The typical IOL 10 may be made from a variety of materials such as but not limited to polymethylmethacrylate (PMMA), silicones, hydrophilic acrylics, hydrophobic acrylics or combinations thereof.
[0036] [0036]FIG. 3 illustrates a polishing chamber 20 , which may be made of any suitable material such as but not limited to glass, plastic, metal or a combination thereof but preferably, glass for visibility and cleaning ease. Polishing chamber 20 may be of any geometric configuration defining an interior area 28 and having one or more depending on the polishing method selected, but preferably two openings 22 and 24 therein for ease in cleaning the same. Preferably, polishing chamber 20 is of a tubular configuration defined by a tubular body 26 having two opposed open ends 22 and 24 . Tubular body 26 may optionally decrease in diameter abruptly to form partial end walls 25 at one or both open ends 22 and/or 24 for increased structural integrity. Open end 22 is defined by an extended rim 44 . As illustrated in FIG. 4, extended rim 44 is suitable for removable attachment, by various methods known to those skilled in the art, to end 41 of tubing 40 . Suitable methods of attachment include but are not limited to friction fit, male and female threaded means, snap fit interlocking means and tab and groove interlocking means whereby snap fit interlocking means is preferred for ease of assembly and strength of the removable attachment. Optionally, a perforated cap or frit 46 may be snap fit onto extended rim 44 prior to attachment of end 41 of tubing 40 . Removably attached to opposed end 43 of tubing 40 by attachment methods such as those discussed above, but preferably by snap fit interlocking means, is a gas source 38 of air or any other inert gas or gases. After attaching gas source 38 to polishing chamber 20 using tubing 40 , a retaining material 34 is placed in interior area 28 at open end 22 as best illustrated in FIG. 5. Suitable retaining material 34 includes but is not limited to glass-spun wool, cotton, wool, and other natural or synthetic fiber materials of like density, but preferably glass-spun wool to avoid air borne fiber contamination within the manufacturing facility. After placing retaining material 34 in interior area 28 , polishing media 36 and IOLs 10 are loaded within interior area 28 . Suitable polishing media 36 includes but is not limited to glass beads, silica gel, silica and aluminum oxide whereby silicone and aluminum oxide is preferred due to ready availability at low cost. After the polishing media 36 and IOLs 10 are placed within polishing chamber 20 , retaining material 34 is placed in interior area 28 to fill the same at open end 24 . A perforated cap or frit 46 is then removably attached in accordance with methods discussed above to extended rim 48 of open end 24 . It is preferred that frit 46 is removably attached by snap fit interlocking means to extended rim 48 for ease of use. Once assembled as described, the length of polishing chamber 20 is preferably vertically positioned and gas source 38 is activated to provide a flow of one or more inert gases such as for example but not limited to air through polishing chamber 20 to polish IOLs 10 placed therein. Preferably the one or more inert gases are forced through said polishing chamber at a rate of approximately 1 to 6 cubic feet per minute. After an adequate amount of time to polish IOLs 10 , preferably approximately 2 to 60 hours but most preferably approximately 12 to 48 hours, frit 46 is removed from extended rim 48 and retaining material 34 is removed from interior area 28 . Polishing media 36 and IOLs 10 may then be poured from polishing chamber 20 into an appropriately sized sieve to separate the polished IOLs 10 from polishing media 36 .
[0037] Another method of dry polishing IOLs 10 in accordance with the present invention to produce more defined peripheral edges 18 on optic portion 12 is likewise provided. More defined outer peripheral edges 18 are desirable to reduce or prevent posterior capsular opacification of IOLs 10 after implantation thereof within an eye. The subject dry polishing method utilizes an IOL container 50 as illustrated in FIGS. 6 and 7. IOL container 50 may be made of any suitable material such as but not limited to glass, plastic, natural or synthetic rubber, metal or a combination thereof but preferably a combination of glass or rigid plastic and flexible plastic or rubber for function and durability. IOL container 50 is preferably of an elongated shape with one or more but preferably numerous flexible optic loops 51 . Preferably IOL container 50 is formed by one or more but preferably one rigid arm member 88 with numerous flexible optic loops formed therewith or attached thereto. Flexible optic loops 51 are formed with slots 52 to accommodate any number of haptics 14 on IOL 10 . IOLs 10 are removably positioned and maintained by friction within flexible optic loops 51 as illustrated in FIG. 7. Haptics 14 of IOLs 10 extend from slots 52 in flexible optic loops 51 to allow polishing of the same. IOL container 50 may be fixed within polishing chamber 20 as illustrated in FIG. 8 by snapping rigid arm member 88 within retaining means 86 . In accordance with this particular method, polishing chamber 20 may optionally have only one open end 22 rather than two open ends 22 and 24 . If polishing chamber 20 has two open ends 22 and 24 , one open end 22 is removably or permanently sealed by means discussed above with a cap 84 . Interior area 28 is then loaded through open end 24 with polishing media 36 . Suitable polishing media 36 includes but is not limited to glass beads, silica gel, silica and aluminum oxide whereby silicone and aluminum oxide is preferred due to ready availability at low cost. After filling polishing chamber 20 with polishing media 36 , the second open end 24 is removably sealed by means discussed above with a cap 84 . If polishing chamber 20 has only one open end 22 , interior area 28 is loaded through open end 22 with polishing media 36 . After filling polishing chamber 20 with polishing media 36 , open end 22 is removably sealed by means discussed above with a cap 84 . Polishing chamber 20 once filled with IOL container 50 and polishing media 36 , is placed on a tumbler (not shown) to axially rotate the same as described in U.S. Pat. Nos. 5,571,558, 5,649,988 and 5,725,811 each incorporated herein in its entirety by reference. After allowing polishing chamber 20 to rotate at a specified speed, preferably 50 to 200 revolutions per minute but most preferably 100 revolutions per minute, and for a specified period of time, preferably 2 to 48 hours but most preferably 8 to 36 hours, polishing chamber 20 is removed from the tumbler. The tumbler speed and the duration of the tumbling will vary depending upon the material of IOL 10 , the polishing media 36 selected and the degree of smoothness desired. A cap 84 is removed from polishing chamber 20 and polishing media 36 is removed therefrom. IOL container 50 may then be removed from polishing chamber 20 and polished IOLs 10 removed from flexible optic loops 51 .
[0038] Another method of dry polishing IOLs 10 in accordance with the present invention to produce more defined outer peripheral edges 18 on optic portion 12 in effort to reduce or prevent posterior capsular opacification of IOLs 10 after implantation within an eye utilizes an IOL container 80 as illustrated in FIGS. 9 and 10. IOL container 80 may be made of any suitable material such as but not limited to glass, plastic, natural or synthetic rubber, metal or a combination thereof but preferably a combination of glass or rigid plastic and flexible plastic or rubber for function and durability. IOL container 80 may be formed in any configuration that allows the haptics 14 and optic portions 12 of IOLs 10 to be exposed while protecting outer peripheral edge 18 from polishing. Preferably IOL container 80 is of an elongated form defined by one or more but preferably one rigid arm member 88 . Rigid arm member 88 is equipped with one or more but preferably numerous optic clamps 90 . Slots 92 are formed in optic clamps 90 to allow haptics 14 to extend through beyond the exterior 94 of optic clamps 90 when an IOL 10 is positioned within the interior 96 thereof. In order to allow for IOL 10 to be positioned within interior 96 , each optic clamp 90 has a hinge 98 , a tab 100 and a groove 102 for opening and securely closing optic clamp 90 . To place IOL 10 within interior 96 , optic clamp 90 is opened by removing tab 100 from groove 102 and thus opening hinge 98 . IOL 10 is then positioned within the optic clamp 90 formed to specifically conform or match outer peripheral edge 18 with haptics 14 extending through slots 92 . Optic clamp 90 is then securely closed by inserting tab 100 into groove 102 for removable attachment by snap fit interlocking means, thus closing hinge 98 . IOL container 80 loaded with IOLs 10 is illustrated in FIG. 10. Haptics 14 of IOLs 10 extend from slots 92 in optic clamp 90 to allow polishing of the same. IOL container 80 may be fixed within polishing chamber 20 as illustrated in FIG. 11 by snapping rigid arm member 88 within retaining means 86 . In accordance with this particular method, polishing chamber 20 may optionally have only one open end 22 rather than two open ends 22 and 24 . If polishing chamber 20 has two open ends 22 and 24 , one open end 22 is removably or permanently sealed by means discussed above with a cap 84 . Interior area 28 is then loaded through open end 24 with polishing media 36 . Suitable polishing media 36 includes but is not limited to glass beads, silica gel, silica and aluminum oxide whereby silicone and aluminum oxide is preferred due to ready availability at low cost. After filling polishing chamber 20 with polishing media 36 , the second open end 24 is removably sealed by means discussed above with a cap 84 . If polishing chamber 20 has only one open end 22 , interior area 28 is loaded through open end 22 with polishing media 36 . After filling polishing chamber 20 with polishing media 36 , open end 22 is removably sealed by means discussed above with a cap 84 . Polishing chamber 20 once filled with IOL container 80 and polishing media 36 , is placed on a tumbler (not shown) to axially rotate the same as described above. After allowing polishing chamber 20 to rotate at a specified speed, preferably 50 to 200 revolutions per minute but most preferably 100 revolutions per minute, and for a specified period of time, preferably 2 to 48 hours but most preferably 8 to 36 hours, polishing chamber 20 is removed from the tumbler. The tumbler speed and the duration of the tumbling will vary depending upon the material of IOL 10 , the polishing media 36 selected and the degree of smoothness desired. A cap 84 is removed from polishing chamber 20 and polishing media 36 is removed therefrom. IOL container 80 may then be removed from polishing chamber 20 and polished IOLs 10 removed from optic clamp 90 .
[0039] Another method for dry polishing IOLs 10 in accordance with the present invention uses polishing chamber 20 . In this particular method, polishing chamber 20 may optionally have only one open end 22 rather than two open ends 22 and 24 . If polishing chamber 20 has two open ends 22 and 24 , one open end 22 is removably or permanently sealed by means discussed above with a cap 84 . Interior area 28 is then loaded through open end 24 with IOLs 10 and polishing media 36 . Suitable polishing media 36 includes but is not limited to glass beads, silica gel, silica and aluminum oxide whereby silicone and aluminum oxide is preferred due to ready availability at low cost. After filling polishing chamber 20 with IOLs 10 and polishing media 36 , the second open end 24 is removably sealed by means discussed above with a cap 84 . If polishing chamber 20 has only one open end 22 , interior area 28 is loaded through open end 22 with IOLs 10 and polishing media 36 . After filling polishing chamber 20 with IOLs 10 and polishing media 36 , open end 22 is removably sealed by means discussed above with a cap 84 . Polishing chamber 20 once filled is placed on a tumbler (not shown) to axially rotate the same as described above. After allowing polishing chamber 20 to rotate at a specified speed, preferably 50 to 200 revolutions per minute but most preferably 100 revolutions per minute, and for a specified period of time, preferably 2 to 48 hours but most preferably 8 to 36 hours, polishing chamber 20 is removed from the tumbler. The tumbler speed and the duration of the tumbling will vary depending upon the material of IOL 10 , the polishing media 36 selected and the degree of smoothness desired. Cap 84 is removed from polishing chamber 20 and IOLs 10 and polishing media 36 are removed from polishing chamber 20 . IOLs 10 are separated from polishing media 36 using an appropriately sized sieve.
[0040] The methods for dry polishing IOLs of the present invention are described in still greater detail in the Examples that follow.
EXAMPLE 1
[0041] Dry Polishing of Silicone and Hydroview™ Intraocular Lenses
[0042] Ten silicone intraocular lenses and ten Hydroview intraocular lenses were obtained for dry polishing in accordance with the present invention. Hydroview lenses are bicomposite lenses having a hydrogel optic portion and polymethylmethacrylate haptics. Two glass polishing chambers tubular in form having a 2-inch internal diameter and 6 inches in length were obtained. One open end of one of the polishing chambers was capped with a plastic perforated cap or frit and the chamber was loaded with a glass spun wool plug in contact with the frit. Ten Hydroview lenses were then interspersed throughout approximately 20 gm of glass beads of 0.4 mm or less diameter and loaded onto the glass spun wool plug within the polishing chamber. Another glass spun wool plug was used to fill the remainder of the polishing chamber interior space prior to using a frit to cap the second polishing chamber opening. An air source was connected to the one of the frits using plastic tubing and a clamp and air flow was activated. The airflow was maintained at approximately 2 cubic feet per minute for approximately 48 hours. An air flow rate through the polishing chamber should be maintained at a level adequate to keep the IOLs buoyant and should be maintained for a period of time sufficient to achieve the desired level of IOL smoothness. IOL polishing occurs as the glass beads churned by the airflow bombard the IOLs. Additionally, one open end of the other polishing chamber was capped with a plastic perforated cap or frit and the chamber was loaded with a glass spun wool plug in contact with the frit. Ten silicone lenses were then interspersed throughout approximately 20 gm of glass beads of 0.4 mm or less diameter and loaded onto the glass spun wool plug within the polishing chamber. Another glass spun wool plug was used to fill the remainder of the polishing chamber interior space prior to using a frit to cap the second polishing chamber opening. An air source was connected to the one of the frits using plastic tubing and a clamp and airflow was activated. The airflow was maintained at approximately 4 cubic feet per minute for approximately 24 hours. An air flow rate through the polishing chamber should be maintained at a level adequate to keep the IOLs buoyant and should be maintained for a period of time sufficient to achieve the desired level of IOL smoothness. IOL polishing the glass beads churned by the airflow bombard the IOLs. The results Ls so produced are set forth in Chart A-1&2 below.
[0043] IOLs—Dry Polish
control RMS 2 days polished RMS 4 days polished roughness roughness RMS roughness optical haptic optical haptic optical haptic 1 10.256 4.385 29.447 7.894 25.53 7.41 2 13.603 3.991 35.53 9.63 26.379 7.139 3 9.021 9.228 30.169 5.965 23.953 9.95 4 14.169 5.169 31.406 6.011 34.543 38.136 5 11.361 6.69 27.94 8.433 31.79 51.588 6 14.647 6.679 33.41 6.04 33.549 6.396 7 9.42 10.265 27.376 11.401 30.185 45.595 8 9.591 11.48 29.938 — 30.902 40.866 9 9.844 9.404 27.504 — 29.084 52.389 Average 11.3 7.5 30.3 7.9 29.5 28.8 s.d. 2.2 2.7 2.8 2.1 3.6 20.5
[0044] [0044]
EXAMPLE 2
[0045] Dry Polishing of Hydroview Intraocular Lenses
[0046] Twenty Hydroview intraocular lenses were obtained in accordance with the present invention. About 500 g of the polishing medium, a mixture of 0.5 mm and 0.1 mm glass beads, was placed in a clear glass bottle with a screw cap. The IOLs were loaded into the bottle with the polishing medium. The bottle was tightly capped and placed horizontally on a tumbler. The tumbler was set at 100 revolutions per minute for 36 hours. The IOLs were samples at the end of 2 hours, 4 hours, 8 hours, 12 hours, 16 hours and 32 hours. The sampled IOLs were analyzed for optic peripheral edge sharpness, haptic polishing and optic zone polishing using high magnification microscopes. The results are set forth below in Charts B-1 and B-2, and Chart C, wherein the 8-hour samples show that the desired polishing can be achieved while maintaining reasonable sharpness on the optic peripheral edges.
[0047] The methods of dry polishing IOLs as well as the IOLs produced thereby in accordance with the present invention provide a cost effective means by which multiple IOLs may be simultaneously polished without having to dry or dehydrate the same prior to further processing steps such as applying a consistent surface coating. Additionally, the methods of dry polishing IOLs of the present invention allows the manufacturer to polish an IOL's haptics while maintaining well defined edges on the optic portion thereof. This is and important feature to eliminate future posterior capsular opacification of the IOL after implantation.
[0048] While there is shown and described herein certain specific methods using specific equipment of the present invention, it will be manifest to those skilled in the art that various modifications may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims. | A process of dry polishing molded or lathe cut intraocular lenses or like medical devices to removing flash, sharp edges and/or surface irregularities therefrom. The process includes gas and/or rotational tumbling of the intraocular lenses or like medical devices in a dry polishing media. The process is suitable for single piece and multipiece intraocular lenses of varying composition. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority, under 35 U.S.C. § 119, of German Patent Application DE 10 2006 024 380.3, filed May 24, 2006; the prior application is herewith incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to a method for controlling operating processes or measuring processes in connection with a printed image applied to a printing material. A camera device acquires image information from the printed image on the printing material. The data acquired through the use of the camera is compared in a computer with the digital image of a printed image. Operating processes or measuring processes are triggered by the computer on the basis of the identified image printed on the printing material. The invention also relates to an apparatus for carrying out the method.
[0003] Modern printing presses offer a large number of possible settings, which makes the operation correspondingly complicated for personnel. Given the large number of possible operations, the risk of an error during the entry or selection of functions necessarily also rises. There is therefore an endeavor to make the operation of printing presses and other complex machines in the graphics industry easier. Such a method is disclosed by European Patent Application EP 1 433 606 A1, corresponding to U.S. Patent Application Publication No. US 2006/0101043 A1, which relates to a device for operating a printing press. The printing press has a control station with an operating desk for that purpose, which makes it possible for the operator to detect and to change colors of the current pages of a print job. The relevant colors for the printed page involved are supplied to the operator by the plant or appropriate control system, in order to reduce the risk of a mistake. The selection of the respective page number can be made manually through the operating desk or through the use of image detection with a camera and corresponding software evaluation. That therefore prevents the operating personnel form inadvertently carrying out color changes on a different page of a printed product from the product page actually selected. The appropriate changes of color are possible only for the product page selected.
[0004] In particular, when image recognition is used, however, there is the risk that the page displayed is not recognized correctly by the camera and then erroneous operations are possibly carried out.
SUMMARY OF THE INVENTION
[0005] It is accordingly an object of the invention to provide a method and an apparatus for operating printing presses, which overcome the hereinafore-mentioned disadvantages of the heretofore-known methods and devices of this general type and which further reduce the possibility of erroneous operations.
[0006] With the foregoing and other objects in view there is provided, in accordance with the invention, a method for controlling operating processes or measuring processes associated with a printed image applied to a printing material. The method comprises positioning the printing material on a desk, capturing or acquiring, with a camera device, image information from the printed image on the printing material, comparing, in a computer, data captured or acquired by the camera device with digital image data of the printed image, and triggering operating processes or measuring processes with the computer on a basis of an identified printed image on the printing material. Objects or persons covering the printing material are detected with the camera device and specific operating processes or measuring processes are carried out on a basis of the detected objects or persons covering the printing material.
[0007] The method according to the invention for controlling operating processes or measuring processes is suitable, in particular, for use in sheetfed offset printing presses, since proof sheets regularly have to be pulled and these have to be measured appropriately in order to determine deviations of the finished printed products from the original. To this end, the proof sheets are placed on a desk, so that the sheets can be registered by a camera device. This camera device is able to acquire image information from the printed image on the printing material lying on the desk, and the data acquired by the camera is compared in a computer with digital image data from the printed image. Operating processes or measuring processes can then be triggered in the computer on the basis of the identified printed image on the printing material. The computer can be a separate operating computer which communicates with the machine control system of the printing press, but the computer can also be integrated into the machine control system of the printing press. If the triggering of operating processes or measuring processes is carried out on the basis of the printed image acquired by the camera, then this acquisition must proceed as far as possible without error. In this case, however, there is the risk that the operating personnel will bend over the printing material and cover certain regions of the printed image. In this case, reliable recognition of the printed sheet being displayed is impossible, which is likewise the case when objects cover the printing material. In particular, during the performance of measuring processes, it is important that the printing material not be covered by objects or persons, since otherwise the measuring instrument is not able to carry out any correct measurement. In the case of operating processes, the computer can also be set up in such a way that the objects and persons covering the printing material are computed out of the acquired image, and in this way the partly covered image can nevertheless still be identified and can be compared with corresponding printing originals.
[0008] In accordance with another mode of the invention, provision is made for automatic recognition of the front or reverse side of a printing material to be carried out through the use of the camera and the digital image data of the printed image, and for operating processes or measuring processes to be triggered as a function of the side of the printing material lying on top. Through the use of the image recognition by the camera, it is possible for the computer to recognize the display of the front or reverse side of a printing material on the desk and to enable only those processes which correspond to the corresponding front or reverse side being displayed. To this end, in the computer in each case the front and reverse side of a printing material are known as digital printing originals, so that the image data acquired by the camera device can be compared with the digital data of the front or reverse side of the printing material. Identification of the front or reverse side by the computer is thus possible.
[0009] In accordance with a further mode of the invention, provision is made for the digital image data to be prepress stage data from the printed image. In this case, the digital image data is transmitted from the prepress stage to the computer through the use of data storage media or a network link. This avoids the entry of the digital image data into the computer by hand. Automatic transmission of the prepress stage data is carried out, in particular, in the case of the network link to the prepress stage, and thus it is possible for this data to be used for the recognition and assignment of operating processes or measuring processes in a printing material being displayed.
[0010] In accordance with an added mode of the invention, provision is made for operating elements to be provided on the control station of a machine processing printing material, and for the function of the operating elements to depend on the identification of the printed image of a printing material displayed on a desk area. For instance, specific operating elements on the control station can be blocked or rendered inactive if they are not needed due to the printed image of the sheet presently displayed. Thus, the risk for the operating personnel of using operating elements which do not match the printed sheet presently being displayed is reduced. It is thus possible to use only those operating elements which also actually serve a function for the sheet presently being displayed. For instance, in particular, operating push buttons for the adjustment of the inking zones can be adjusted in their functions on the basis of the printing material being displayed, so that only the inking zone operating push buttons which are assigned to appropriate inking zones on the printing material being displayed also have functions. This can also apply similarly to further operating push buttons, in particular to what are known as “soft keys” in the case of touch screens, which can in each case be populated differently. The population of the push buttons appearing on the touch screen or else of push buttons which are actually physically present, can then likewise be carried out on the basis of the printed image being displayed. Thus, the operating elements change, in each case in a manner matched to the printing material presently being displayed and thus, ultimately, also in a manner matched to the print job presently to be processed.
[0011] In accordance with an additional mode of the invention, this can, moreover, be implemented to the effect that when the printing material lying on the desk area is turned, the display of operating elements is matched to the respective side of the printing material lying on top. Thus, even within a print job, during recto and verso printing (perfecting), the operation can be matched appropriately to the front or reverse side of a printing material currently being displayed if the operator turns the sheet by hand.
[0012] In accordance with yet another mode of the invention, provision is advantageously made for the printing material to be displayed on a desk and for the relative orientation of the printing material in relation to its desk area to be registered by the camera device. This is important in particular when the desk is simultaneously used as a measuring desk. In this case, a measuring device is able to move over the sheet being displayed and measure color, register, etc. In order to be able to carry out these measurements correctly, it is important for the measuring instrument to know the coordinates of the sheet being displayed and in particular of the printed image. The orientation of the printing material and of the printed image applied thereto can be registered by the camera, according to the present invention, and thus any possible deviations relative to the measuring device present on the desk can be processed electronically and corrected. In the event of severe deviations, a warning can also be output to the operating personnel, so that the operating personnel can be given an opportunity to correct the orientation of the printing material on the desk appropriately. Erroneous measurements can therefore be avoided.
[0013] In accordance with yet a further mode of the invention, provision is advantageously made for the triggering of specific operating processes or measuring processes to also include the at least temporary blocking of specific operating processes or measuring processes. In particular, if there are objects on the sheet being displayed or the operating personnel bend over the desk, there is the risk that operating elements will inadvertently be pressed and thus operating processes will be unintentionally triggered. In addition, as a result of objects lying on the desk, a measuring instrument measuring the sheet can be damaged. These situations can be detected by the camera device and appropriate image processing, so that operating processes or measuring processes that would lead to an erroneous operation or damage to the measuring instrument are then blocked, at least until the objects and the persons have been moved away again.
[0014] In accordance with yet an added mode of the invention, provision is made for any measurements carried out on the printing material through the use of a measuring instrument to be stored in the computer and, in the event that double measurements are carried out, for a warning signal to be output or for the double measurement not to be carried out. Each measuring process and the associated measured sheet can be stored in the computer on the basis of the image recognition and the camera acquisition. Double measurements can be determined through the use of the comparison of measuring processes and measured sheets in the computer. Should the computer determine such a double measurement, then a warning signal is output to the operating personnel, so that the operating personnel become aware that a double measurement has already been carried out. The method according to the invention can, however, also be used for the purpose of not allowing double measurements to arise at all. In this case, if a sheet has already been measured once and it has been detected by the camera that the same sheet is displayed on the measuring desk again or that the personnel have inadvertently left the sheet lying thereon and not removed it, the measuring instrument is blocked and instead a warning signal is output, so that a double measurement is not carried out. In this way, double measurements can reliably be prevented.
[0015] In accordance with yet an additional mode of the invention, provision is made for gestures of an operator to be registered with the camera device and, through the use of the gestures, for measuring points on the printing material to be selected for registration by a measuring instrument that is present. The gestures of an operator can, for example, be extended fingers, with which the operator points to specific points of the printing material being displayed. These points identified in this way are then used as measuring points, for example for the color measuring instrument. This is expedient in the case of color measuring instruments which do not measure the entire sheet to be measured but are merely moved to individual measuring points. In this case, the measuring points which are to be approached do not then have to be entered into the measuring instrument in a cumbersome manner through a keyboard or a touch screen. Instead, it is sufficient for the operating personnel to point to the appropriate points of the printing material being displayed. The measuring points will then be registered by the camera, processed by the computer and passed on to the measuring instrument for the performance of the measuring processes.
[0016] In accordance with again another mode of the invention, the desk area has operating elements for setting inking zones in inking units of a printing press, a registration is made through the use of the camera device as to whether the operating elements are touched by fingers of an operator or by other objects and, depending on the contact detected, the operating elements are either enabled or blocked. In particular, in the case of operating elements for adjusting the inking zones, which elements are normally located in the close physical vicinity of the desk area for the printing material, there is the risk that inking zones will be adjusted inadvertently by a body part of the operating personnel being supported on the inking zone operating elements or objects lying around on the latter. Through the use of the camera device, it is now possible to detect whether the operating elements are actually being touched only by the fingers of the operating personnel or whether objects are located on them or other body parts of the operating personnel are operating the inking zones inadvertently. This increases the operating reliability further and avoids rejects resulting from inadvertently adjusted inking zones.
[0017] With the objects of the invention in view, there is also provided an apparatus for carrying out the method, in which the camera device is removable and suitable for use as a video magnifier.
[0018] Since a camera device is present in any case for the method according to the invention, it can thus also be used for other purposes. The camera device, which is expediently located above the desk, can be removed from an anchoring device by the operating personnel and then used as a video magnifier. Since the camera device must have a relatively high resolution in any case for its capabilities, it is excellently well suited for use as a video magnifier. During use as a video magnifier, the operating personnel hold the camera at a relatively short distance above the printing material and therefore in each case register only details of the printing material. Therefore, multiple enlargement of details of the printing material is possible, which can then be displayed on a monitor connected to the camera device. Through the use of the camera device, the operating personnel can thus scan the printing material in detail and have details of the printed image displayed highly magnified on the monitor and, in this way, detect even marginal printing defects without difficulty.
[0019] In accordance with a concomitant feature of the invention, the desk area or the area around the operating elements for inking zone control have light sources. In this case, in order to assist the camera device, small light sources, in particular in the form of LEDs, are fitted to the desk and thus lead to a backlit push button array. This makes it easier for the camera to detect objects or body parts of persons on the operating elements, since these cover the lights, which can be detected unambiguously by the camera. If no lights are covered, it may be assumed that there are no objects or body parts on the printing material. In this way, the lights further reduce the risk of erroneous operations or inadvertent operations.
[0020] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0021] Although the invention is illustrated and described herein as embodied in a method and an apparatus for operating printing presses, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0022] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a diagrammatic, perspective view of a control station according to the invention for a printing press; and
[0024] FIG. 2 is a fragmentary plan view of a backlit operating panel in the control station of a printing press.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen an operating station 8 which has a desk 2 for the display of sheet printing materials or sheets 6 . The desk 2 is angled slightly forward, so that operating personnel have a good view of the displayed sheets 6 . In a region on the right hand side there is a monitor 4 , which is constructed as a touch screen and permits the display and entry of operating data. The monitor 4 is connected to a computer 9 , which is located in a lower region of the operating station 8 , underneath the desk 2 . The computer 9 in turn is able to communicate through a communications link 11 with a machine computer of a printing press 10 and with computers of a prepress stage 12 . It is thus possible to arrange for data from the prepress stage 12 and for data from the printing press 10 to be displayed on the monitor 4 . Furthermore, settings can be carried out through the monitor 4 , both on the printing press 10 and, for example, in the case of plate exposers, on the prepress stage 12 . The computer 9 is additionally connected to an image inspection measuring instrument 5 , which permits diverse measuring processes to be carried out on the displayed sheets 6 . The measuring instrument 5 is configured in such a way that it is able to scan the entire surface of a displayed sheet 6 . In this case, color measurements and register measurements, etc. can be carried out. Furthermore, in a front region of the desk 2 , there is an operating strip having inking zone operating push buttons 3 . The inking zone operating push buttons 3 are disposed in such a way that they can be assigned to the inking zones of a sheet 6 lying on the desk 2 . The operating station 8 has a roof, which carries a light 7 and a camera 1 . The camera 1 is capable of registering not only the displayed sheet 6 but also regions around the sheet 6 , in particular the inking zone operating push buttons 3 . The camera 1 is in turn connected to the computer 9 , so that the images acquired by the camera 1 can be processed in the computer 9 through image recognition. The lamp 7 is used for illuminating the displayed sheets 6 and in this way improves the image processing by the camera 1 . Through the use of the camera 1 and the image recognition in the computer 9 , it is possible to acquire printed images from sheets 6 and to compare them with further data in the computer 9 . This data can, for example, be digital prepress stage data which is supplied by the prepress stage 12 . However, it can also be digital data from print jobs, which are transmitted to the computer 9 through a print shop network or to the computer 9 through interchangeable data storage media. If, in this way, the image data of the print job currently to be finished is known to the computer 9 , a comparison through the use of the camera 1 and the image processing in the computer 9 can be carried out as to whether or not the sheet 6 displayed on the desk 2 matches the print job currently being processed. If this is not the case, a warning can be output to the operating personnel, for example through the monitor 4 , so that the operating personnel know immediately that a sheet 6 has inadvertently been displayed which does not originate from the print job actually running but clearly from another stack of printed products.
[0026] It is moreover possible, through the use of the image processing in the computer 9 , to determine the position of a sheet 6 relative to the desk 2 . For instance, a crooked display of the sheet 6 relative to the desk 2 can be detected, which is important in particular when carrying out measurements through the use of the image inspection measuring instrument 5 . The measuring instrument 5 can normally perform correct measurements only when the sheet is also oriented appropriately. If the sheet 6 is detected as being incorrectly oriented through the use of the camera 1 and the image processing in the computer 9 , a warning is likewise output on the monitor 4 and the measurement is not carried out until the sheet is displayed on the desk 2 within tolerances. In addition, through the use of the camera 1 , objects and body parts of the operating personnel lying on the sheet 6 can be detected, so that measurements by the image inspection measuring instrument 5 are likewise prevented if the measuring instrument 5 would collide with the objects lying on the sheet 6 during the registration of the sheet 6 .
[0027] Since there are inking zone operating push buttons 3 in the front region, they are particularly susceptible to inadvertent and erroneous operation by the personnel, because there is always the risk that, when bending forward for the purpose of obtaining a better view of the sheet 6 , the operating personnel will support themselves on the inking zone operating push buttons 3 and thus inadvertently change the latter. Since settings in the inking units of the printing press 10 are trigged with the inking zone operating push buttons 3 , there is the acute risk in this case that, as a result of these changed settings, prints with changed colors will be produced and that rejects will accumulate unnoticed. Such inadvertent operation can be prevented through the use of the present invention by locking the operating push buttons 3 when such supporting by the operating personnel is detected. This is also done through the use of the camera 1 and the image processing in the computer 9 . As soon as it is not merely permissible body parts of the operating personnel, such as the fingers, which are detected on the operating push buttons 3 , the inking zone operating push buttons 3 are all blocked or at least partly blocked in the region affected. Inadvertent operation and changing of the inking zone setting in the printing press 10 can therefore be prevented and thus, at the same time, the accumulation of unnecessary rejects as well. In addition, through the use of the camera 1 , the turning of sheets 6 by the operating personnel can be detected, so that the inking zone operating push buttons 3 and operating elements on the monitor 4 can in each case be matched to the side displayed on the top of the sheets 6 which are printed on both sides. Thus, when turning sheets 6 , the operating personnel do not themselves have to select the associated side on the monitor 4 , so that the risk of erroneous operations is also reduced substantially in this case.
[0028] It is additionally possible to avoid unnecessary measuring processes through the use of the method according to the invention. For example, it is entirely possible for the operating personnel to display an already measured sheet 6 inadvertently for the second time or to inadvertently leave a sheet 6 lying on the desk after the measurement. By using the image content and production markings, such as those from the counting mechanism of the printing press 10 , the camera 1 , in cooperation with the image processing of the computer 9 , can identify each sheet 6 and assign the associated measuring processes. If the camera 1 establishes that the sheet 6 currently displayed has already been measured, then a further measuring process by the image inspection instrument 5 is firstly avoided and a warning to the operating personnel is output on the monitor 4 . If the operating personnel deliberately ignore this warning through the use of an appropriate entry push button on the monitor 4 , it is of course also possible for a second measurement to be carried out deliberately.
[0029] The measuring instrument 5 can also be configured in such a way that it does not move to all of the sheet 6 for measurements but only to specific measuring points on the sheet 6 , selected by the operating personnel. In this case, the appropriate measuring points have to be entered into the measuring instrument 5 . According to the present invention, this can be done through the use of simple gestures, i.e. for example through the use of finger pointing of the operating personnel to the appropriate points of the sheet 6 being displayed. The operating personnel then merely still have to point to the desired measuring points of the sheet 6 , so that these points are detected automatically through the use of the camera 1 and the image processing in the computer 9 . The computer 9 then transmits to the measuring instrument 5 the measuring points selected through the use of the gestures of the operating personnel. The same is also true of other settings, such as the selection of colors for the inking zone operating panel push buttons 3 . If the operating personnel point to appropriate colors of the sheet 6 , the inking zone operating push buttons 3 are populated in accordance with the color selected by the gestures of the operating personnel. The gestures of the operating personnel can also be used for the purpose of positioning a cursor on the monitor 4 . In this case, too, the camera 1 registers movements of the fingers of the operating personnel, for example, and converts them into corresponding movements of the cursor on the monitor 4 .
[0030] The camera 1 fitted in the upper region of the operating station 8 can additionally be configured as a removable video magnifier. In this case, the camera 1 can be removed from an anchoring device and thus used for the closer examination of the sheet 6 . For this purpose, the camera 1 is either connected to the operating station 8 through an appropriately long cable connection, or wireless transmission of the image signals from the camera 1 to the computer 9 is carried out. The camera 1 then has a rechargeable battery for power supply. As soon as the camera 1 is deposited in this anchoring device again, the rechargeable battery can be charged up automatically by the mains or network. The operator can then move the video magnifier, that can be removed in this way, over the surface of the sheet 6 and have detailed enlargements of the sheet 6 displayed on the monitor 4 . Quality control is therefore possible through the use of the camera 1 equipped as a video magnifier.
[0031] FIG. 2 shows a portion of the operating panel for the inking zone operating push buttons 3 . It can be seen that a plurality of inking zone operating push buttons 3 are always disposed one above another for one inking zone, so that the selection of the inking zone openings can be controlled by the operating personnel by touching the inking zone operating push buttons 3 . In order to improve the detection of touching of the inking zone operating push buttons 3 by the operating personnel through the use of the camera 1 , the inking zone operating push buttons 3 can be backlit. This can be done, firstly, as can be seen at the left-hand edge, through the use of light-emitting diodes 13 disposed around the operating push buttons 3 or, as can be seen in the central region, through the use of additional particularly brightly illuminating light-emitting diodes 13 within the inking zone operating push buttons 3 . As a result of this luminous contrast, the image recognition through the use of the camera 1 and the computer 9 is improved considerably, so that in particular small objects can also be distinguished reliably from touching by fingers of the operating personnel. | A method for controlling operating processes or measuring processes in connection with a printed image applied to a printing material, includes acquiring image information from the printed image on the printing material with a camera device. The data acquired by the camera is compared in a computer with digital image data of the printed image. Operating processes or measuring processes are triggered by the computer on the basis of the identified printed image on the printing material. The printing material is displayed on a desk, the camera device detects objects or persons covering the printing material and specific operating, processes or measuring processes are triggered on the basis thereof. An apparatus for carrying out the method is also provided. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to fabrics. More particularly, disclosed herein is an elastomeric mesh fabric for furniture and other applications intended to impart reduced wear on articles, such as clothing worn by a furniture user, in contact therewith.
BACKGROUND OF THE INVENTION
[0002] Resilient mesh has become an increasingly common fabric for use in seating and other applications. In furniture applications, the mesh is typically retained under tension by a peripheral framework. Mesh retained in such a manner has been employed as the sole support surface and in combination with subsidiary support surfaces in back, seat, and other furniture components. The present inventor has contributed to this art with a plurality of inventions, including the Elastomeric Material Application System disclosed in U.S. Pat. No. 6,996,895, the Methods and Arrangements for Securing Fabric of U.S. Pat. No. 7,251,917, and Post-Assembly Tension Adjustment in Elastomeric Material Applications as taught by U.S. Pat. No. 7,517,024 with each of these being incorporated herein by reference.
[0003] The use of resilient mesh in furniture support applications has been found to be advantageous for a number of reasons. In addition to the modern and clean appearance that mesh support panels provide, mesh is advantageous for its breathability. Resilient mesh also reduces zones of discomfort and excess pressure. Moreover, resilient mesh can be retained and potentially adjusted to have varied degrees of tension thereby to provide varied degrees of support for different areas of a person's body.
[0004] The structure of a typical prior art elastomeric mesh panel is shown in FIGS. 1 , 2 A and 2 B. The mesh panel, which is indicated generally at 10 , is a woven fabric formed by a series of warp threads 12 interlaced with generally orthogonally disposed weft strands 14 . Each warp thread 12 is commonly formed by helically wound first and second strands 12 A and 12 B, which are normally formed from resilient elastomeric material. Each weft strand 14 is normally formed from a resilient yarn, which can be wider than it is thick thereby to have a band shape. As used herein, the term yarn shall be held to mean a plied strand composed of fibers or filaments. The warp threads 12 are separated by a distance a, and the weft strands 14 are separated by a distance b.
[0005] The weft strand 14 in this prior art arrangement is woven through the first and second strands 12 A and 12 B of each warp thread 12 as shown in FIG. 2B . The mesh panel 10 can be considered to have an occupant side facing the furniture user and the material of the user's clothing and an opposite side facing away from the occupant. The weft strand 14 is woven through the strands 12 A and 12 B to have flat portions alternatingly disposed to the occupant side and then to the opposite side of the mesh panel 10 . The flat portions are generally coplanar with the mesh panel 10 when the panel 10 is flat. Under this arrangement, flat portions M of the weft strand 14 will face the furniture occupant and the material of the occupant's clothing, and flat portions O will face away from the furniture occupant.
[0006] Both ends of each flat portion M and O pass from the same side of the mesh panel 10 between the strands 12 A and 12 B. With this, depending on the side to which the flat portion M or O is disposed, both ends of each flat portion M or O will either pass from the material side to the opposite side or vice versa. Adjacent weft strands 14 are identically configured but staggered so that where one strand 14 has a flat portion M to the material side of the panel 10 the adjacent strands 14 will have flat portions O to the opposite side of the panel 10 and vice versa. Under this configuration, aside from the portions passing between the strands 12 A and 12 B, roughly half of each weft strand 14 is disposed to the material side of the panel 10 .
[0007] While advantageous for multiple reasons, a significant problem exhibited by resilient mesh has come to be recognized by the present inventor, namely, that the structure of the elastomeric mesh typical of the prior art undesirably acts as a mechanism for pulling, chewing, and tearing fibers away from the occupant's clothing. What is theorized is that the yarn forming the weft strands 14 , which stretch when pressure is applied thereto, act much like tweezers to extract fibers from the occupant's clothing. As the weft strands 14 are stretched, their constituent fibers transform from being more generally unaligned and haphazardly disposed to a greater degree of alignment thereby potentially pinching and retaining fibers from the occupant's clothing. Consequently, an expensive suit can become haggard and worn by repeated exposure to mesh panels 10 so constructed.
[0008] This harm to the furniture user's clothing can readily be appreciated by reference to the opposite side of a mesh support surface chair that has been used for a significant period of time. Having further reference to FIG. 3 , for example, a mesh panel 10 is retained in tension relative to a framework 100 . There, fibers 102 that have been removed from the seat occupant's clothing have accumulated on the opposite side of the mesh panel 10 giving a clear indication of the wear and damage caused by the ‘chewing’ phenomenon exhibited by the mesh panel 10 .
[0009] Advantageously, the present inventor has appreciated that the large surface area in contact with the occupant's clothing and the flat orientation of the weft strands 14 relative to the occupant's clothing contribute to the pulling and tearing effect. With the relatively large surface area of the flat portions M of the weft strands 14 contacting the occupant's clothing, a greater number of fibers are vulnerable to being ripped therefrom and a more efficient ‘chewing’ action is achieved. Based on this appreciation and knowledge, the present inventor has discovered that it would be advantageous to minimize the surface area of the yarn or weft strands 14 that is in direct and flat contact with an occupant's clothing while still exploiting the advantageous characteristics that elastomeric mesh fabric can provide.
SUMMARY OF THE INVENTION
[0010] Accordingly, the present invention is founded on the basic object of providing a mesh fabric that imparts less wear on material in contact therewith.
[0011] An underlying object of the invention is to provide a mesh fabric with yarn strands that exhibit reduced surface contact with material in contact therewith.
[0012] These and further objects and advantages of the present invention will become obvious not only to one who reviews the present specification and drawings but also to those who have an opportunity to experience an embodiment of the mesh fabric disclosed herein. However, it will be appreciated that, although the accomplishment of each of the foregoing objects in a single embodiment of the invention may be possible and indeed preferred, not all embodiments will seek or need to accomplish each and every potential advantage and function. Nonetheless, all such embodiments should be considered within the scope of the present invention.
[0013] In carrying forth these objects, an elastomeric mesh according to the invention has weft strands interwoven with warp threads with each warp thread comprising first and second elastomeric strands and the weft strands comprising a resilient yarn. When the mesh fabric is viewed in cross section, at least some of the weft strands are disposed in a first pattern with a series of portions that trough below the rightwardly disposed strand of each warp thread, rise to a crest atop the leftwardly disposed strand of the adjacent warp thread, and then fall in a downturned face that passes between the leftward and rightward strands of that adjacent warp thread. At least some of the weft strands can be disposed in a second pattern with a series of portions that trough below the leftwardly disposed strand of each warp thread, rise to a crest atop the rightwardly disposed strand of the adjacent warp thread, and then fall in a downturned face that passes between the leftward and rightward strands of that adjacent warp thread.
[0014] The first and second patterns can be disposed in alternation to contribute to directional stability in the elastomeric mesh fabric, and the first and second strands of the warp threads can be helically wound. In one such embodiment, the first and second strands can cross over one another once between each weft strand. Moreover, the weft strands can have a width and a thickness with the width being greater than the thickness such that the weft strands have a band shape.
[0015] A component of an article of furniture can thus be formed with an elastomeric mesh fabric as disclosed herein retained relative to a framework. Many furniture and other components are possible and within the scope of the present invention except as it might be expressly limited. By way of example, the component of the article of furniture can comprise a seat back, a seat bottom, or some other portion of an article.
[0016] One will appreciate that the foregoing discussion broadly outlines the more important goals and features of the invention to enable a better understanding of the detailed description that follows and to instill a better appreciation of the inventor's contribution to the art. Before any particular embodiment or aspect thereof is explained in detail, it must be made clear that the following details of construction and illustrations of inventive concepts are mere examples of the many possible manifestations of the invention.
BRIEF DESCRIPTION OF DRAWINGS
[0017] In the accompanying drawing figures:
[0018] FIG. 1 is a view in front elevation of a panel of elastomeric mesh under the prior art;
[0019] FIG. 2A is a magnified view in front elevation of a portion of a panel of elastomeric mesh as taught by the prior art;
[0020] FIG. 2B is a cross-sectional view of the panel of elastomeric mesh pursuant to the prior art of FIG. 2A taken along the line 2 B- 2 B;
[0021] FIG. 3 is a perspective view of a panel of prior art elastomeric mesh applied to a seat back structure after a period of use;
[0022] FIG. 4A is a magnified view in front elevation of a portion of a panel of elastomeric mesh according to the present invention;
[0023] FIGS. 4B and 4C are cross-sectional views of the panel of elastomeric mesh of FIG. 4A taken along the lines 4 B- 4 B and 4 C- 4 C;
[0024] FIG. 5 is a perspective view of a panel of elastomeric mesh applied to a seat back structure after a period of use depicting the desired resultant benefits of the invention; and
[0025] FIG. 6 is a perspective view of panels of elastomeric mesh applied to a seat back structure and a seat bottom structure.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0026] The mesh fabric disclosed herein is subject to a wide variety of embodiments. However, to ensure that one skilled in the art will be able to understand and, in appropriate cases, practice the present invention, certain preferred embodiments of the broader invention revealed herein are described below and shown in the accompanying drawing figures. Therefore, before any particular embodiment of the invention is explained in detail, it must be made clear that the following details of construction and illustrations of inventive concepts are mere examples of the many possible manifestations of the elastomeric mesh taught herein.
[0027] Turning more particularly to the drawings, an elastomeric mesh panel according to the present invention is indicated generally at 10 in FIG. 4A and then in first and second cross sections in FIGS. 4B and 4C . There, the elastomeric mesh 10 again comprises a woven fabric formed by a series of warp threads 12 interwoven with generally perpendicularly disposed weft strands 14 . Each warp thread 12 is formed by helically wound first and second strands 12 A and 12 B. The strands 12 A and 12 B can be formed from a resilient material, such as an elastomer. Each strand 12 A and 12 B can be formed as a single elastomeric strand or of multiple elastomeric strands, which may or may not be interwoven. Each weft strand 14 can be formed from a resilient yarn, which can be wider than it is thick thereby to have a band shape. The warp threads 12 are again separated by a distance a, and the weft strands 14 are again separated by a distance b.
[0028] The weft strand 14 is woven through the first and second strands 12 A and 12 B of each warp thread 12 in the alternating patterns shown in FIGS. 4B and 4C . In the first pattern as depicted in FIG. 4B , the weft strand 14 is disposed in what may be considered a rolling wave configuration in a first direction, which is left to right in the drawing when the mesh panel 10 is viewed in cross section, with a series of left-to-right inclined portions that trough below the rightwardly disposed strand of each warp thread 12 , rise to a crest atop the leftwardly disposed strand of the next warp thread 12 , and then fall in a downturned face that passes between the leftward and rightward strands of that next warp thread 12 .
[0029] In the second pattern as depicted in FIG. 4C , the weft strand 14 is disposed in a rolling wave configuration in a second direction, which is right to left in the drawing again when the mesh panel 10 is viewed in cross section, with a series of right-to-left inclined portions that trough below the leftwardly disposed strand of each warp thread 12 , rise to a crest atop the rightwardly disposed strand of the next warp thread 12 , and then fall in a downturned face that passes between the leftward and rightward strands of that next warp thread.
[0030] In this embodiment, the first and second strands 12 A and 12 B of the warp threads 12 are helically wound with the strands 12 A and 12 B passing over one another once between each weft strand 14 . As a result, the first strand 12 A will be the leftward strand in one row of the weft strand 14 , but it will be the rightward strand in the adjacent row of the weft strand 14 . The first and second patterns are disposed in alternation to maintain directional stability in the elastomeric mesh panel 10 and to ensure consistent performance of the mesh panel 10 .
[0031] Under this arrangement, it will be appreciated that, although roughly half of the weft strand 14 will continue to face the user of the furniture, the great majority of the weft strand 14 would tend to be spaced from direct contact with the furniture occupant and the material of the furniture occupant's clothing. Only the portions M will tend to be in a plane of direct contact with the clothing of a furniture occupant or other contacting material. The remaining portions of the weft strand 14 are angled relative to and spaced from the opposed surfaces of the mesh panel 10 . With this, the angled and spaced portions of the weft strand 14 will be less efficient in ‘chewing’ fibers from a furniture occupant's clothing or other material, and that material will tend to exhibit less wear and damage through contact with the mesh panel 10 .
[0032] As shown in FIG. 5 , a mesh panel 10 according to the invention retained relative to a framework 100 would ideally pull and tear fewer fibers from the material of a user's clothing. As a result, fewer fibers will be accumulated, and the clothing will suffer less damage over time. As described in the present inventor's U.S. Pat. No. 6,996,895, U.S. Pat. No. 7,251,917, and U.S. Pat. No. 7,517,024, which are incorporated herein by reference, the framework 100 and the retained mesh panel 10 could take the form of a wide variety of furniture and other components. By way of example as seen in FIG. 6 , a framework 100 and a mesh panel 10 could form a seat back 102 , a seat bottom 104 , or some other component of an article of furniture.
[0033] With certain details and embodiments of a mesh fabric 10 according to the present invention disclosed, it will be appreciated by one skilled in the art that changes and additions could be made thereto without deviating from the spirit or scope of the invention. This is particularly true when one bears in mind that the presently preferred embodiments merely exemplify the broader invention revealed herein. Accordingly, it will be clear that those with certain major features of the invention in mind could craft embodiments that incorporate those major features while not incorporating all of the features included in the preferred embodiments.
[0034] Therefore, the following claims are intended to define the scope of protection to be afforded to the inventor. Those claims shall be deemed to include equivalent constructions insofar as they do not depart from the spirit and scope of the invention. It must be further noted that a plurality of the following claims may express certain elements as means for performing a specific function, at times without the recital of structure or material. As the law demands, these claims shall be construed to cover not only the corresponding structure and material expressly described in this specification but also all equivalents thereof that might be now known or hereafter discovered. | An elastomeric mesh fabric with weft strands interwoven with warp threads with the goal of imparting reduced wear on clothing and other articles in contact therewith. Each warp thread has first and second elastomeric helically wound strands, and the band-shaped weft strands comprise a resilient yarn. The weft strands are disposed in alternating first and second patterns that minimize contact area between the weft strands and clothing and other articles. Seat backs, seat bottoms, and other furniture components can be formed by retaining the elastomeric mesh fabric relative to frameworks. | 3 |
BACKGROUND OF THE INVENTION
The invention relates to a massaging device in which a plurality of massaging members are arranged on a shaft borne by a carrier, particularly bow-shaped, provided with a handle.
In a known massaging device of this type the massaging members consist of spheres arranged rotary close together on a rigid shaft. An adjustable mechanism allows one or three spheres to be inserted at will. With this device, however, only superficial therapeutic stimuli are produced in the region of the massaged surface. Even when the spheres are pressed against the surface of the skin fairly energetically, the depth effect is only slight. In addition, the surface massaged in each instance is relatively small; because of the rounded contours of the body, even an increase in the number of spheres would increase the massaged surface only slightly.
There is further known a massaging apparatus in which a shaped rubber roller is arranged rotary on a bow provided with a handle. This roller, to be sure, is adjustable to the rounded contours of the human body. The massaging effect, however, is likewise slight.
SUMMARY OF THE INVENTION
The object of the invention is to procure a massaging device for self-massage, the effect of which corresponds largely to manual massage by another person and in particular further permits the production of deeper therapeutic stimuli without any great expenditure of energy.
This object is obtained pursuant to the invention in that the massaging members are arranged spaced apart and fixed against rotation on the shaft and in that the shaft is designed flexible and is joined, fixed against rotation, with the carrier.
This device permits effortless self-massage, this massage having the advantages of manual massage by another person. Stroking, tapping, kneading and rubbing movements may be performed by means of the spaced-out massaging elements not rolling over the skin. Since the parts of the skin are able to escape outward between the massaging elements, this therapeutic stimulation may be accomplished without great expenditure of energy. There is likewise no irritation of the skin or roots of hairs. The flexibility of the shaft permits adjustment to all body contours. Even the regions of the joints at the foot, knee, elbow and shoulders can be massaged effortlessly and over a large area. The force with which the massaging members are pressed against the human body is determined basically by the force with which the entire device is pressed against the body. In addition, however, by placing the free hand on the massaging elements the massages may be still more precisely administered and guided.
There is a further advantage in that therapeutic pharmaceutical substances may be distributed uniformly over the parts of the body to be treated with the massaging device. The therapeutic substances are herein not only distributed on the surface of the skin, but are massaged deeply into the parts of the body to be manipulated. Since the device is actuated by the force of the body itself and has no outside motive force, it may alternatively be used for a massage under water, either in the bathtub or in a humid chamber, such as a shower or sauna, with no danger of the human body under treatment being exposed to electric shock. The device thus not merely comes very close in effect to manual massage by another person, but surpasses this by the combination of physical effects possible (massage, therapeutic substance, heat and water).
In a preferred embodiment rolling members are arranged rotary on the shaft between the massaging members, the radius of which rolling members is smaller than the distance of the effective area of massage of the massaging members from the center line of the shaft. These rolling members prevent skin and tissue from being pressed out too hard between the massaging members. When these pressed-out parts come in contact with the rolling members, they are subjected to practically no stress at all, as the rolling member rolls across the skin with little force. In particular these rolling members permit the use of massaging members having a relatively great diameter, which because of the correspondingly great curvature can be moved over the surface of the body relatively easily, even when they are pressed into the skin.
The rolling members preferably have a spherical shape. These spheres, even with deformation of the shaft, retain an approximately uniform effectiveness. Since because of the unlike rolling radius the spheres ride with unlike rolling speed on the parts of the skin pressed out, an additional frequently sought rubbing effect is produced.
The massaging members should preferably have the shape of a disk, in particular essentially the shape of an ellipsoid. This permits gentle but nevertheless deep penetration into the surface of the body.
In addition, the massaging members, for adjustment to the rolling members, may have lateral recesses. This permits very strong deformations of the flexible shaft, without interlocking of massaging and rolling members.
It is advantageous if the massaging and rolling members consist of synthetic material, in particular polyamide. A smooth surface is obtained, one which slides on the skin with little friction. Further, these parts may be cleaned readily. Instead of this, the aforesaid members may alternatively consist of wood, horn, metal, glass or other solid material.
It is advisable to render the massaging members particularly secure against rotation on the shaft, since forced fits or the like may detach in case of the given stress, in particular with a flexible shaft. In the simplest case cementing will suffice. Alternatively, however, a shaft with multiple-cornered cross section and a correspondingly shaped opening in the massaging members may be used. It is particularly advantageous, however, if the massaging members have a center opening with keyway and are secured against rotation by means of keys mounted at intervals on the flexible shaft.
So that the shaft may adjust to the contours of the body with the least possible expenditure of energy, it should be longitudinally extensible. Instead of this, the bow-shaped carrier may alternatively be elastically deformable.
The flexibility and extensibility of the shaft is most simply obtained by its being constructed of a spring shaft, i.e. a tightly wound helical spring with an approximately cylindrical surface.
For fastening to the carrier, mountings are advantageously soldered or welded on at the ends of the shaft. Such mountings may consist of flat steel and may be provided with a mounting hole matching a mounting hole in the carrier, the two holes being penetrated by a common fastening element, such as a screw or a rivet. Another mounting consists of a threaded part, for example a threaded bolt, cooperating with a second threaded part, for example a nut, reaching through the carrier.
Especially preferably, however, will be a mounting consisting of a pin having a head and an adjoining key, while in the carrier is provided a cut open laterally, which has a width corresponding to the diameter of the pin and is provided with a keyway for receiving the key. This results in particularly simple assembly, because the pin needs only to be pushed into the cut by its part not occupied by the key, whereupon the key under the influence of th force of expansion of the shaft or of the spheres engages in the keyway, so that the shaft is held fast against rotation in the carrier.
The ends of the flexible shaft and/or the mountings may be concealed by coverings. This is not only visually more pleasing, but alternatively permits the device to be used up to close to the ends for massaging. The covering for a shaft end may for example consist of two hemispherical dishes with surfaces of separation perpendicular to the shaft. Another covering has two dishes whose surface of separation lies in the plane of the sphere.
Structurally it is advantageous if the carrier has a metal sphere, at least partially sheathed with synthetic material, for attachment of the flexible shaft. The metal sphere is then able to receive the forces appearing, while the synthetic material needs to contribute only slightly to the stability. The metal sphere may, for example, be coated with synthetic material. It may alternatively be provided with two dishes of synthetic material.
In addition, the covering of synthetic material may have a continuation which forms a stemmed handle lying perpendicular to the shaft. A simple metal sphere suffices as stiffening, even in complicated shapes.
The cover of synthetic material may alternatively form a handle roughly conforming to the center section of the sphere.
In some cases it is advantageous if the handle is adjustable or interchangeable. Adjustability permits a handle arrangement adapted to the purpose in each case. Interchangeability permits the use of handles of a variety of lengths, for example in order to be able to massage the parts of one's own back better.
In addition, there is the possibility of providing a carrier with more than one flexible shaft with massaging members arranged at intervals, in order to be able to this fashion to massage still greater areas simultaneously or more intensively.
An additional massaging member for point-by-point massage is advantageously arranged stationary on the carrier, preferably at the end of a stemmed handle. This massaging member permits targeted massaging manipulations, as are otherwise performed with the fingertips.
There is on the whole obtained a massaging device which may be used particularly for self-massage, but alternatively for massage by another person, and hence is useful for enhancing physical fitness and strength and eliminating complaints of the locomotor apparatus in humans (muscles, tendons and joints).
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail below, by means of the example represented in the drawing, in which
FIG. 1 shows, partly in view, partly in section, a first embodiment of a massaging device;
FIG. 2, in three-dimensional representation, the end piece of the flexible shaft and the covering, massaging and rolling members to be arranged in this region,
FIG. 3, a section through another embodiment of a massaging member,
FIG. 4, partly in view, partly in section, an additional embodiment of a massaging device,
FIG. 5 in view, an additional embodiment,
FIG. 6, in section, the end region of the flexible shaft of FIG. 5 and
FIG. 7, in side view, a bow end.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the embodiment of FIGS. 1 and 2 is provided a bow 1 consisting of flat stainless steel, which in its center carries a handle 2. The handle 2 is part of a plastic dish 3, which rests against the bow 1 from the outside. A second dish 4 rests against the bow from inside. All parts are held together by means of a screw 5, which engages in a thread of the plastic part 3. At the lower end of the handle is inserted a massaging element 6, making point-by-point massage possible.
On a flexible shaft 7, formed by a spring shaft, are alternately arranged massaging members 8, fixed against rotation, and rotary rolling members 9. The massaging members 8 have the shape of an ellipsoid, the rolling members 9 the shape of a sphere. The massaging members for example have a diameter of 22 mm and the spheres a diameter of 18 mm. In massage the massaging members 8 may therefore be pressed into the surface of the body one member deep, while at the same time skin and tissue parts lying between them may be pushed aside outward by a definite amount.
The rotational fixation of the massaging members 8 is obtained by means of keys 10 soldered on the flexible shaft 7, which keys engage in the corresponding keyways 11, adjoining the center bore 12 of the massaging members 8. The bores 13 of the rolling members 9 likewise have such keyways 14, so that they may be pushed over the keys 10. Since there is no key in their region, the rolling members 9 are freely rotary. Alternatively, the massaging members 8 may be affixed to the flexible shaft by gluing, soldering or other means.
The ends 15 of the flexible shaft 7 are soldered firmly at the face 16 to a mounting 17 of flat steel bent angular. Each mounting 17 has a mounting hole 18, through which extends a screw 19 engaging by its thread in a thread 20 at the end of bow 1. The head of the screw is provided with a toggle 21 made of plastic, for simplifying operation and for protection.
For protection of the soldered joint is provided a covering 22, consisting of two hemispheres 23 and 24, the end 25 of the hemisphere 24 fitting clampingly under the edge 26 of the hemisphere 23. The hemisphere 23 is pushed with its center hole 27 onto the shaft 7, the hemisphere 24 with its slot 28 over the mounting 17. Then when the shaft 7 and the mounting 17 are soldered together, the two hemispheres may be pushed together and connected by clamps. The position of this sphere is secured in that on one side a massaging member 8 is held on the adjacent key 10 in a forced fit and hence axially secured, while on the other side the inner surface 29 of the hemisphere 23 is able to come to rest on the face of the mounting 17.
In the embodiment of FIG. 3 a massaging member 30 is arranged on the shaft 7 between two spherical rolling members 9, which member 30 has lateral recesses 32 in opposed position to the ellipsoid shape 31, which recesses are adjusted approximately to the spherical shape, so that mobility is retained even with a heavily bent shaft 7.
There is a variation in the embodiment of FIG. 4, in relation to that of FIG. 1, insofar as the mounting 33 is soldered not by the face, but by the flat side at the face 16 of the shaft 7 and again carries the thread 34 for the screw 19 provided with the toggle 21. In addition, the plastic covering of bow 1 consists of two plastic dishes 35, which are pushed on the bow from either side by means of a screw 36. The ends of these plastic dishes extend to the mounting 33 and form the covering thereof.
In the embodiment of FIG. 5 the bow is provided not with a stemmed handle as in FIGS. 1 and 4, but with a handle 37 provided the length of the bow, which is injected as plastic coating 38 around the center section of the bow. As revealed in FIGS. 6 and 7, a pin 39 is soldered in the ends of the flexible shaft 7, which pin has a head 30 and, adjoining the head 40 but at a distance from the face 16 of the shaft 7, a key 41. The ends of the bow 1 are provided with a notch 42 open toward the side, the width of which matches the diameter of the pin 39 and which has a keyway 43 for the introduction of the key 41. The shaft 7, provided with its pin 39 and all massaging members 8 and rolling members 9, is extended slightly and pushed by the free pin sections into the notches 42. When the tensile stress is at an end, the pinheads 40 are pulled against each other, permitting the keys 41 to snap into the keyways 43. The rotational fixation of the shaft 7 is thereby secured. For covering the ends of the shaft 7 are provided hemispheres 44, which may be similar in operation to the rolling members 9.
Numerous modifications of the embodiments illustrated are possible. For example, the handle 2 of FIG. 1 may very easily be replaced by another, longer, bent handle, so that parts of the back may be more easily reached. The massaging and rolling members here consists of polyamide; they may however alternatively consist of wood, metal or many other synthetic materials. The bow may be made pf steel, aluminum, other metals or plastic, it may be flat or round in section, it may be designed stiff or springy. When the bow is elastic and hence longitudinal extensibility of the shaft 7 does not matter, the latter may alternatively consist of a flexible rod or tube. The flexible shaft 7 may alternatively consist of spring steel wires or strips wound, twisted stranded or woven together. It may alternatively have a covering. If necessary, a shaft of rubberlike material may alternatively be possible. In some cases it will suffice to make the cylindrical bores in the massaging members smaller than the cylindrical bores in the rolling members, so that the massaging members are force-fitted on the shaft 7, the rolling members in contrast having a free sliding fit. Another alternative consists in fastening the handle 37 of FIG. 5 rotary on the bow 1, so that it will be capable of rotation from a position parallel to the center section of the bow into a position swung out of the plane of the bow.
The force that must be exerted on the device in order to effect bending of the shaft 7 may be expected to be on the order of about 1.5 to 2 kg. The axial prestress in the built-in state may be almost zero.
It will be understood that the claims are intended to cover all changes and modifications of the preferred embodiments of the invention, herein chosen for the purpose of illustration which do not constitute departures from the spirit and scope of the invention. | A plurality of non-rotating disc-shaped massaging members are fixed on a flexible shaft held at its ends by a bow. Spherical rolling members between the massaging members space the massaging members apart and limit their depth of depression into the skin. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
None. However, Disclosure Document No. 032545 was filed in the Patent Office on May 28, 1974, and a separate paper requesting transfer of that document to this application is filed herewith.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to road apparatus and more particularly to a packer having a plurality of rotating tires attached to a maintainer. (404/128)
2. Description of the Prior Art
STOLP, U.S. Pat. No. 3,291,013, has suggested attaching a wheel compacter or packer behind a maintainer or motor grader. He disclosed having the packer towed from the middle of the packer attached to a single pivot point connected to the motor grader. The packer was lifted by two hydraulic cylinders extending from the middle of the packer to a point substantially above the hitch on the motor grader. Inasmuch as the packer was towed by a pivot, each of the four connections of the hydraulic cylinders to the packer and motor grader were necessarily ball and socket joints or some other type of universal pivoting joint.
Also, the following U.S. Pat. Nos. were considered in preparing this patent application: OWENS ET AL, 2,127,485; SUMMERS, 2,270,390; HASTINGS 2,559,427, and PLAS, 2,685,777.
SUMMARY OF THE INVENTION
1. New and Different Function.
We have invented a packer to be attached to a motor grader wherein the packer is attached by pivoted links to two points on the motor grader and the packer is lifted or pushed down by a single cylinder working through pivoted links which are mounted at the center of the motor grader at the same level as the links. The cylinder acts against a yoke which extends to the packer. With this arrangement, the packer is attached to the grader by attaching two side plates on either side of the tool box of a conventional motor grader and and by changing the hitch behind the motor grader to a special mounting bracket for the hydraulic cylinder. In this way we simplify attaching the packer to the motor grader, reduce its expense and make it simpler to operate.
Furthermore, a small moldboard is attached to the front of the packer, It is angled in the opposite direction to the moldboard on the maintainer. Therefore, we are able to smooth out and level out the dirt of the maintainer so a full, complete operation may be carried on by one pass over the road in many cases. The small moldboard scraper or blade is attached by arms sliding in sleeves and is raised and lowered by a hydraulic cylinder on each side. Thus, not only the entire operation may be carried out by one pass over the road, but only one man is required for the entire operation.
2. Objects of this Invention.
An object of this invention is to pack roads immediately behind a motor grader.
Another object is to further smooth the dirt and pack it, all in a single operation.
Other objects are to achieve the above with a device that is sturdy, compact, durable, lightweight, simple, safe, efficient, maneuverable, versatile, and reliable, yet inexpensive and easy to manufacture, install, adjust, operate, and maintain.
The specific nature of the invention, as well as other objects, uses, and advantages thereof, will clearly appear from the following description and from the accompanying drawing, the different views of which are not to the same scale.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side elevational view of one embodiment of this invention shown in the packing position.
FIG. 2 is a side elevational view, to a larger scale, of the packer attached to a motor grader with the packer in the raised position, parts are broken away for clarity.
FIG. 3 is a top plan view of the packer shown above, the motor grader not being shown in this figure.
FIG. 4 is a detail of one of the draft links taken on line 4--4 of FIG. 1.
FIG. 5 is a side elevational view of a modification with a small moldboard attached to the packer with only a portion of the plate shown and with wheels of the packer broken away for clarity. Also, the hydraulic cylinder and draft links are not shown for clarity.
FIG. 6 is a top sectional view taken on line 6--6 of FIG. 5 showing the attachment of the small moldboard to the packer.
FIG. 7 is a back elevational view of the moldboard not attached to the packer.
FIG. 8 is a sectional view taken substantially on line 8--8 of FIG. 6 showing details of construction.
FIG. 9 is a sectional view taken substantially on line 9--9 of FIG. 6 showing details of construction.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Packer 10, according to this invention, is basically conventional. I.e., it has a rectangular peripheral frame 12. (FIG. 3). To this rectangular frame 12 are mounted bearing blocks 14 to which are journaled shafts. A plurality of pneumatic tires 16 are mounted upon the shafts which pack the road. A super structure frame includes two beams 18 which extend above the tires immediately above the bearing blocks 14. Runners 20 are spaced about one-fourth from the sides. Stated otherwise, the distance between the two runners 20 is approximately half the width of the rectangular frame 12. As stated before, the packer as described to this point is purely conventional and the construction of such packer is well within the skills of those mechanics knowledgeable in the road building and maintaining arts.
A pair of ears 22 is mounted upon the rectangular frame 12 immediately forward of the connection of the runners 20 to the forward portion of the rectangular frame 12. Between the two ears on each side is connected draft link 24. The connection of the link between the ears may be accomplished by a pin as is customary in this art.
Two plates 26 are used. Each of the plates 26 is bolted to the frame of the motor grader by a plurality of bolts (six illustrated) at the lowest and most rear position it can be attached. Each of the two plates 26 is connected one on each side of the tool box of a conventional motor grader. At the lower, rear corner of each plate is attached a pair of plate draft ears 28. Each of the draft links 24 is pinned to the plate draft ears by a pin as is conventional in the art. Therefore, it may be seen that we have provided for the pulling or the draft of the packer 10. Also, particularly referring to FIG. 2, when the packer is in the raised position, the draft links 24 provide a certain flexibility so that the front tires 16 of the wheel packer 10 can be raised off the ground and the packer is not merely hinged to the rear of the motor grader M.
On each of the runners 20 and centered between the two beams 18 is a pair of press ears 30. The lower part of press or fork link 32 is attached to each of the press ears 30 by a pin, conventionally. The fork links are so referred inasmuch as they have two plates of metal which are spaced from one another at the top so yoke arm 34 may extend between the two plates. Another plate is welded between the two spaced-apart plates at the bottom so the bottom plate of the fork link 32 fits between the two press ears 30 of each pair, as stated before. As indicated, each of the yoke arms 34 is pinned, conventionally, to the top of the fork links 32. The forward end of each yoke arm extends to trunnion 36 which is securely and rigidly attached to the upper portion of each of the plates 26 at about the midpoint of the length of the plate (FIG. 2).
The two arms 34 are connected by yoke beam 38. The yoke beam 38 is located vertically above about the forward portion of the rectangular frame 12 which would be about vertically above the ears 22 thereon. At the midpoint of the beam 38 is located a boss to which is attached clevis 40 of the rod 42 of hydraulic cylinder 44. The hydraulic lines from the hydraulic cylinder 44 have not been shown for clarity of illustration, but it is understood that modern motor grader equipment and all modern road building equipment has a source of hydraulic pressure and these hydraulic lines can be connected thereto so the hydraulic cylinder 44 can be operated. It is understood that it is a double acting cylinder, being able to either lift the packer 10 through the yoke or push down on the packer 10 through the yoke. The bottom of the cylinder 44 is attached to a special lug 46 which is attached to the rear of the motor grader in lieu of the hitch normally located thereon. The replacement of a normal hitch with a lug for this purpose is well within the skill of ordinary mechanics of this art.
Therefore, it may be seen that the packer 10 may readily be raised to an elevated position, as seen in FIG. 2, so that the motor grader may be turned or backed into position when working around uneven grades, such as ditches and the like. Also, it may be seen that when in the normal operating position, as seen in FIG. 1, weight may be transferred from the motor grader through the yoke arms 34 onto the packer 10 itself. Specifically, we prefer to use a hydraulic cylinder capable of transferring approximately 5600 lbs (about 2500kg) of weight from the motor grader onto the packer 10. Specifically in the embodiment we have built we have found that a five-inch cylinder (about 12-1/2 cm) with a 16-inch (about 40 cm) stroke works well when operated upon normal pressures available, which are about 800 psi. (About 600 kg/cm 2 ). Specifically, it may be seen that the hydraulic cylinder will exert about 15,700 lbs of working force (about 7,150 kg) which will be about 5600 lbs of downward pressure at the press links or fork links 32.
As stated before, the links permit the packer to be raised in a more level position as seen in FIG. 2. One of the advantages of this is that a pickup, for example, may be towed behind the compacter when the compacter is either raised or lowered; this is particularly advantageous in certain types of operation.
Also, the unit is well adapted to have an earth-working blade or moldboard 50 mounted to the front of the peripherial frame 12 at about the ears 22. The blade 50 on the compacter 10 may be mounted and angled to move dirt opposite the direction dirt is moved by the blade on the motor grader and, thus, greatly incresing the usefulness and versatility of the complete unit.
Referring to and describing specifically the attachment of the blade 50 to the frame 12, it may be seen that two pads 52 are attached to the back of the blade 50. Pad ears 54 are attached to the pads. Arms 56 are pinned between the ears 54. There is a very small clearance between the arms 56, both above and below the pad ears 54. Therefore, referring specifically to FIG. 8, it may be seen that the arms 56 above the pad ear 54 will bear against the pad 52 to prevent the top of the blade 50 from rocking back excessively and, also, that the arm 56 below the pad ear 54 will bear against the bottom of the pad 52 to prevent the bottom of the blade from rocking excessively. The upper portion of the arms 56 are telescoped through sleeves 58 which are attached as by welding to the front portion of the frame 12. There are clearances between all of the joints. I.e., there is clearance between the pad ears 54 and the arm 56. Therefore, one end of the blade may be raised or lowered slightly more than the other end and this angling of difference in elevation between the edges of the blade 50 is accommodated by the clearance in the joints.
Adjacent to each of the pads 52 are mounted lift ears 60. The rod 62 from hydraulic cylinder 64 is pinned to lift ears 60. The top of the cylinder 64 is itself pinned to finger 66 which is attached as by welding to the frame 12.
As before, the hydraulic lines to the two cylinders 64 have not been shown for clarity inasmuch as any mechanic skilled in this art would understand how to attach the hydraulic lines thereto.
Also, road equipment operators are people experienced in maintaining roads and will understand how to adjust the cylinders 64 to maintain the blade 50 at the right position to properly manage the dirt to be packed by the tires 16.
Thus it may be seen that we have provoded a lightweight blade for this purpose.
It will be understood by those skilled in the art that the means for raising and lowering the leading edge or end of the blade, which is the hydraulic cylinder shown to the left of FIG. 6, is much more convenient to be a hydraulic cylinder. However it will be understood by those skilled in the art that on the trailing edge or end of the blade, which is the one shown on the right of FIG. 6, other means for raising and lowering the blade could be used, such as a crank with a screw on the end thereof or a pin extending through the sleeve 58 to a plurality of holes in the arm 56. Although a hole and a pin in the sleeve might be considered a means for maintaining a position once achieved, in the contex of this application, it is intended that it be understood as also designating a means for raising and lowering.
Thus it may be seen that we have developed a packer well adapted to pack roads immediately behind the motor grader and which is easily attached, operated and may be inexpensively built. The draft links 24 and the press links 32 provide flexibility, but still permit the yoke to push down on the compacter 10.
The embodiment shown and described above is only exemplary. We do not claim to have invented all the parts, elements or steps described. Various modifications can be made in the construction, material, arrangement, and operation, and still be within the scope of our invention. The limits of the invention and the bounds of the patent protection are measured by and defined in the following claims. The restrictive description and drawing of the specific example above do not point out what an infrigement of this patent would be, but are to enable the reader to make and use the invention.
SUBJECT MATTER CLAIMED FOR PROTECTION | A pneumatic tire-type compacter is mounted to be towed behind a road maintainer to pack the road immediately after it is graded. A single hydraulic cylinder raises the packer unit for maneuvering the grader; also, the hydraulic cylinder provides means for transferring weight from the maintainer onto the packer. Links between the maintainer and compacter provide proper operation. A small moldboard is attached to the compacter in front of the compacter to handle the dirt rolled from the maintainer. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. patent application Ser. No. 60/669,008 filed Jul. 4, 2005.
FIELD OF THE INVENTION
[0002] The present invention relates generally to conference telephones. More particularly, the present invention relates to a wireless handsfree conference phone system.
BACKGROUND OF THE INVENTION
[0003] Conference phones are commonly used in a number of environments, such as meeting rooms, conference rooms, boardrooms and the like, to allow a group of people at a single location to participate in a phone call.
[0004] Many standard telephone sets can provide rudimentary conference abilities through a handsfree mode that uses a speaker and a microphone to communicate audio larger distances from the handset. To avoid echo, many such telephone sets employ half duplex switching so that the microphone and speaker are not active simultaneously. While half duplex switching allows a number of people to sit at a single location and participate in a call, there are a number of short comings to such a rudimentary conferencing capability. For instance, any noises in the room will cut off the far-end audio. Thus speaking, coughing, or paper shuffling will all prevent any inbound audio from being heard. This soon results in halting discussion patterns over the telephone link to the point where even a request to repeat a missing point may not be heard.
[0005] A conference phone is typically defined by having two features. The first feature is the ability to provide a speaker supporting full duplex audio capability that permits simultaneous transmission and reception of audio, and the second feature is a multi-line capability which provides the ability to use more than one phone line to serve as a rudimentary conference bridge. The availability of third party dial in conference bridges has made the multi-line capability feature of these phones redundant to a certain degree, but the feature is still considered to be a standard conference phone offering.
[0006] In large environments, a simple telephone handset in a speakerphone mode is unsuitable as a conference room phone. In large rooms, the audio quality provided by standard speakerphone implementations is not sufficient. To address this problem, dedicated conference phones are provided.
[0007] Dedicated conference phones, such as those offered by Polycom, Inc., ClearOne etc. provide only a handsfree experience. The conventional handsfree conference phone provides a dial pad and display to allow the user to dial and create a conference session. The phone typically has a plurality of microphones, and a single speaker. By using a plurality of microphones, the system can switch between active and passive microphones based on the position of a person speaking.
[0008] One common problem with conference phones is echo. When a remote participant in the call speaks, the voice is reproduced through the speaker of the unit. This sound is then received by the microphones as input, and is provided back to the remote participant with a slight delay. This causes an apparent echo that is often found to be distracting. To address this matter early solutions employed a half-duplex design, so that the microphones and the speaker do not operate simultaneously. A more sophisticated full duplex solution is presently found in dedicated conference phones. The full duplex solution makes use of echo-canceling circuitry to analyze the received signal and subtract that signal from the signal generated by the microphones allowing the speaker and microphones to operate simultaneously.
[0009] To address the needs of larger boardrooms, many conference phone systems make use of slaved microphone units that allow corded satellite units to connect to a central unit. The echo cancellation then factors in the sounds received at all the microphones, including those from the satellite units.
[0010] Recently wireless conference phones have been introduced to allow the phone to be moved between conference rooms or to be easily repositioned in a conference room. These wireless units are virtually identical to their wired analogs, but replace the cord between the phone and a wall jack with a wireless link to a base station connected to the telephone wall jack. These wireless units do not typically offer satellites, and when they do, the satellites are connected to the phone with wires, thus limiting the high degree of mobility and flexibility offered by the wireless phone unit. These wireless units cannot serve large meeting rooms without the ability to attach satellite units.
[0011] Outside of conference phones, simply using a plurality of telephone handsets connected to a single base station is known. This has not been implemented for conference phones due to the great complexity of dealing with echo cancellation across a plurality of different phones each connected to the base station but not to each other.
[0012] It is, therefore, desirable to provide a wireless conference phone system with the ability to support larger conference rooms.
SUMMARY OF THE INVENTION
[0013] It is an object of the present invention to obviate or mitigate at least one disadvantage of previous wireless conference phones.
[0014] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
[0015] Generally, the present invention provides a method and system for connecting a plurality of wireless conference units to an outside world telephone network.
[0016] Whereas previous conference phone systems employed sophisticated switching and echo cancellation in the phone for both a main or master conference phone and each satellite or slave unit, this technique is not optimal for wireless systems. A preferred configuration has wireless conference phone units that do not talk directly to each other, but rather communicate with a base station. The wireless conference phone units, also referred to as PODs, relay information to a base station, which connects the PODs to the outside world telephone network. The outside world telephone network carries call signaling and audio communications between a near-end location and a far-end location. There are many forms of telephone networks that can advantageously be used, for instance, the public switched telephone network (PSTN), a Voice over Internet Protocol (VolP) telephone network service over the Internet, a cellular telephone network and the like.
[0017] Whereas previous conference phone systems have employed sophisticated switching and echo cancellation incorporated into the base phone and each satellite phone, this technique is not always optimal or suitable for wireless conference phone systems.
[0018] In accordance with the invention, wireless conference phone units, or PODs are in communication with a base unit connected to a telephone network. The PODs exchange call signaling and audio communications with a base unit that connects them to the outside world telephone network. In a presently preferred embodiment, each POD operates independently. This allows the POD to be used alone and extra PODs are added as needed to allow coverage of larger conference rooms. As a result, the PODs are not designed to communicate with each other in a master-slave configuration or with a central POD relaying echo cancellation information to the other PODs. However, building complex circuitry in the base station for multi-POD echo cancellation drives up the cost of the base station when the base station will often be used to support only a single POD unit.
[0019] In accordance with the invention a telephone network interface is provided in a base station connected to an outside world telephone network. The audio signal received at the base from the telephone network is transmitted to each POD over a wireless channel. Each POD reproduces the received audio signal on its loudspeaker. Thus far-end audio is reproduced for the near-end conference participants on the speakers of the PODs. The POD microphones pick up near-end audio, which is processed in the POD to remove the loudspeaker audio cross-talk also picked up by the POD microphones. The processed near-end audio signal from each respective POD is transmitted to the base station over a unique wireless channel. The base station receives near-end audio signalling from each POD and sums them all together and delivers the result to the outside world telephone network for transport to the far-end participants. Because the PODs are all located in the same conference room, there is no need to have each POD receive and play the audio generated by other POD units in the room. This simplifies the implementation of the base station and allows for a plurality of independent PODs to connect to the same base station and provide complete coverage in a large conference room environment. The base unit has a processor providing a signal processing capability to perform more complex processing of the received near-end audio signals beyond simply adding them together. For example, a weighted addition process is used, or such other processing as may be desirable, to provide a suitable near-end audio signal for transmission over the telephone network to the outside world. However, the signal processing in the base ensures that the audio signal received from one POD is not delivered to another POD. That is no side-tone is provided to any POD by the signal processing at the base station. The near-end audio signal is delivered only to the telephone network and not to any of the PODs.
[0020] In one of its aspects the invention provides a conference phone system comprising a base station having a telephone line interface, a POD interface and a base control processor coupled to the telephone line interface and the POD interface operable to exchange call control and audio communications signalling between the telephone line interface and the POD interface. The conference phone system has at least one POD unit, each such POD unit having a microphone system, a loudspeaker, a base interface and a POD control processor interconnecting the microphone system, loudspeaker and base interface to exchange communications signalling with the base station via the POD interface and base interface and operable to filter out audio signalling received over the base interface from the signal produced by the microphone system supplied to the base interface.
[0021] In another of its aspects the invention provides a method for conducting a conference call using a base station with a call control processor controlling a telephone line interface connected to a telephone network and a POD interface operable to exchange call control and audio communications signalling between the telephone network and the POD interface and at least one POD control processor unit controlling a microphone system, a loudspeaker and a base interface to exchange communications signalling with the base station POD interface. The method comprises the steps of producing audio output on each POD loudspeaker corresponding to audio signalling received from the telephone network; then performing echo cancellation processing at the POD control processor on the audio signalling produced by the microphone system to remove the audio output received from the telephone network and delivering the echo cancellation output produced by each POD to the base station call control processor for summing and delivery into the telephone network.
[0022] Embodiments of the present invention will now be described, by way of example only, with reference to the attached figures, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a functional block diagram of an exemplary embodiment of the invention having two wireless POD conference units and a base unit;
[0024] FIG. 2 is a functional block diagram of a base unit providing a PSTN line interface;
[0025] FIG. 3 is a functional block diagram of a wireless POD conference unit; and
[0026] FIG. 4 is a schematic of an RF interface provided in the POD and the base units.
DETAILED DESCRIPTION
[0027] The following discussion provides an exemplary embodiment of the present invention. Those skilled in the art will realize that although this discussion is made with reference to specific embodiments, the specific embodiments are not intended as being limiting, but rather are intended solely to provide examples of embodiments of the invention.
[0028] As shown in FIG. 1 , a basic setup of an exemplary conference telephone system comprises a base station unit 100 and two wireless POD units 102 . The base station and POD units communicate over radio frequency (RF) wireless channels, such as in the 2.4 GHz standard ISM RF band. The base station 100 is connected to the outside world telephone network 110 and to the wireless PODs 102 . Each POD has a respective microphone system 112 and a loudspeaker 114 . Preferably the POD microphone system 112 has 3 microphones to pick up audio in all directions around the POD. The wireless PODs are placed within a conference room to position the POD microphones system 112 as close as practicable to each of the conference call participants. During a phone conversation, near-end speech is picked up dynamically by one or more of the POD microphones and far-end speech is reproduced on each respective POD loudspeaker 114 .
[0029] A POD has a keypad 116 providing a user input mechanism to control calling on the system. The keypad has a plurality of switches typically including an on/off switch, an offhook/onhook switch, a volume control, a mute switch and a telephone dialing keypad group of switches, that is, a plurality of key switches labeled to include the numbers 0 to 9, asterisk (*) and octothorp (#).
[0030] The keypad switches are manipulated by a user to answer or place a call over the telephone network. When both PODs are powered up, pressing offhook on one POD preferably activates the other POD as well so that both PODs are in communication with the base station and telephone network. Dialing, muting and going onhook/offhook is done using the keypad of either POD. The PODs have a display 118 to provide call and status information to the users, for example, caller ID, dialed number, transient display of volume levels when the volume controls are manipulated etc.
[0031] A telephone network line interface 104 couples the base to an outside world telephone network 110 and supports call supervisory signalling and audio communication over the telephone network. The audio received from the telephone network is provided as the RxL signal on line 148 which is split at 108 into separate Rx(i) signals for each POD. Thus for the example embodiment employing two PODs, two signals Rx 1 and Rx 2 are produced and sent from the base via RF to each POD simultaneously. The return audio transmitted from each POD, Tx 1 and Tx 2 , is sent via RF to the base unit 100 where each is summed as depicted by summer 106 . The summed audio signal is then provided as the TxL signal on line 146 to the telephone network line interface 102 for supply to the outside world telephone network 110 . In the base, no side-tone or reflection of the transmitted audio received from a POD, i.e. Tx(i), that is, Tx 1 and Tx 2 in the two POD embodiment depicted in the figure, appears on the Rx audio signal that the base sends back to another POD.
[0032] In accordance with the invention, each POD performs Rs own acoustic echo cancellation so that echo and howling coming from a POD is virtually eliminated. Near-end speech picked up by a POD is sent out to the outside world telephone network 110 by the base unit 100 and is not echoed back to itself or to another POD.
[0033] With the ability of the base to block near-end audio of one POD from appearing at another POD, the above arrangement is suitable to allow multiple PODs to be used. The number of PODs that can be used advantageously to communicate audio simultaneously with the base is not limited to the two PODs depicted in the exemplary configuration of FIG. 1 . Three or more PODs can be deployed where the maximum number of PODs will depend on the number of available radio channels and time slots provided in the system wireless design. Thus, in accordance with the invention, near-end audio echo cancellation is performed in the PODs, and consequently a simple base station implementation is achieved that does not greatly increase either the complexity or cost of producing the base station unit.
[0034] FIG. 2 is a functional block diagram of a preferred embodiment of the base station unit 100 . The base has a processor 120 which controls the operation of the elements of the base system. A suitable processor in this regard is a DECT baseband processor produced by National Semiconductor in the SC144xx part family. The base processor 120 runs program code stored in memory 122 , for example an internal flash memory, and any variables and operating parameters are kept in memory 124 , which, in the preferred embodiment, is a 16 kbit external EEPROM serial memory device.
[0035] The processor 120 also provides the necessary RF control signals to the RF module 126 over RF interface 130 , which is described in more detail in the discussion relating to FIG. 4 . The base RF module 126 transmits and receives digital information with each POD using a suitable radio antenna 128 , for example, one configured for use in the 2.4 GHz ISM band.
[0036] For a user interface, the base processor 120 drives an in-use indicator 132 , for example light emitting diode (LED), to indicate when a connection with the outside world telephone network is active. Where the outside world telephone network is the PSTN as depicted in the embodiment of FIG. 2 , the in-use indicator 132 will indicate that the data access arrangement (DM) line interface 136 has gone off-hook, for example, to dial an outgoing call or to carry on a conversation over the telephone network. Preferably the base includes a page key 133 to page the PODs. In the preferred embodiment, the base has a page key 133 , such as a push button switch, that is polled by the base processor and when the page key is pressed, the base signals the PODs causing them to emit an audible signal to enable a user to locate any POD units registered to the base.
[0037] Preferably the base provides a test and update connector 134 , such a connector to a Universal Asynchronous Receiver Transmitter (UART) interface, to enable firmware download and testing functions to be performed.
[0038] A suitable outside world telephone network line interface is provided in the base to support call supervisory signalling with the telephone network and to facilitate audio communication over the telephone network. In the exemplary embodiment, the outside world telephone network is the PSTN and consequently the telephone network interface is configured to connect to the PSTN. A PSTN interface is implemented using a digital access arrangement device, depicted as DAA line interface 136 and protection elements 140 . The DAA line interface 136 provides PSTN data terminal equipment/customer premise equipment functionality to terminate the connection to the PSTN 110 . A suitable DM line interface device is manufactured by Clare, Inc. in their Lite Link (trade-mark) product family parts numbered as CPC5620x. The protection elements 140 include fuses, capacitors and sideactors suitably configured for overcurrent and overvoltage protection to provide the necessary electrical isolation between the outside world telephone network 110 and the rest of the base unit circuitry. For other outside world telephone networks, such as VolP, the devices provided for the telephone network line interface 104 (of FIG. 1 ) will be selected for operation with the media link characteristics and protocols of such other networks.
[0039] The base processor 120 has connections or lines for communication with and control of the other devices in the base unit. For instance, to provide call supervisory signaling to the outside world telephone network, an onhook control line 142 controls the on-hook/off-hook operation of the DM line interface 136 to allow the base to initiate, receive or terminate a call over the telephone network 110 . The DAA line interface produces an audio signal converted from the far-end audio received over the telephone network into the RxL signal 148 . The digital near-end audio received from each of the PODs via antenna 128 is processed and summed by the base processor 120 and the result is supplied as the TxL signal 146 to the DAA line interface 136 for conversion to a suitable analogue form signal for delivery into the outside world telephone network 110 .
[0040] The DM interface 136 also has an on-hook ring detect line 144 to signal processor 120 of an incoming call. The incoming call is reported to each POD which responds by causing ring signaling to be produced on the POD, for example over the POD loudspeakers 114 , and any available caller ID details are displayed on the POD display 118 . In the preferred embodiment, the base includes a record jack 152 to facilitate telephone conversation recording. To provide this capability, an analogue version of the TxL and RxL transmit and receive audio signals is supplied to an amplifier 150 which provides an amplified output that is then available to a recording device connected to recording jack 152 .
[0041] FIG. 3 is a functional block diagram of elements in a preferred embodiment of a POD unit constructed in accordance with the principles of the invention. The POD 102 has a control processor 200 such as a DECT baseband processor produced by National Semiconductor in the SC144xx part family. The POD further includes an RF module 202 , an RF interface 204 , keypad 116 and status indicators 228 . A Digital Signal Processor (DSP) 206 , such as a DSP manufactured by Freescale Semiconductor in the DSP563xx part family, carries out speech signal processing tasks. The POD also has related circuitry for the microphones, loudspeakers, ADC/DAC operations and battery charging function.
[0042] The POD is in wireless communication with the base over a radio channel and each POD has an antenna 201 to transmit and receive radio frequency signaling over the channel. Rx(i) signalling from the base to the POD is received on the POD antenna 201 and supplied to the POD RF module 202 for conversion and recovery of the data contained in the radio signalling. The recovered data is supplied to the POD processor 200 over RF interface 204 . RF interface 204 supports bi-directional communication between the POD processor 200 and the RF module 202 . Consequently, data from the POD to be delivered over the radio channel to the base is supplied to the RF module 202 by the POD processor over RF interface 204 . The RF module 202 in turn converts and encodes the received data onto a radio signal, Tx(i), that is delivered into the radio channel by antenna 201 .
[0043] When digital speech audio information sent by the base is received by the POD control processor 200 from the POD RF module 202 , the POD control processor 200 converts the digital speech into analog form and then transmits it to the DSP unit via a differential interface RX_AUDIO 208 . This analog audio is amplified and converted again into a digital data stream at OPAMP 210 and ADC 212 respectively for supply to the DSP 206 . As a consequence, the DSP is provided with input representative of the received audio. The DSP then performs signal processing of the signal and the resultant digital audio output is converted to analog form at DAC 213 . An OPAMP 214 and power AMP 216 amplify this audio signal and drive the POD loudspeaker 218 thus reproducing far-end audio at the POD.
[0044] For the near-end audio, the user speech is picked up by the microphone system 112 . Preferably the microphone system 112 has three microphones, shown as MIC[ 1 . . . 3 ] in the drawings, arranged to pick up audio from all directions surrounding the POD. The microphone signals are amplified at corresponding OPAMPs 222 and supplied to an analogue to digital converter ADC 212 which converts them to digital for signal processing steps performed by the POD DSP 206 . The POD DSP 206 performs the speech processing, for example, removing from the Tx(i) signal sent to base processor 120 any cross talk or local feedback of the Rx output picked up by the microphones. The resultant digital data is sent to a digital to analogue converter DAC 214 , where the output data is converted to analogue and supplied to an OPAMP 224 which outputs a differential analog signal TX_AUDIO carried on line 226 to the POD control processor 200 . The POD control processor 200 receives this signal and converts it into digital data and transmits it to the base via the RF module 202 as the POD's Tx(i) signal, two examples of which are shown as the Tx 1 and Tx 2 signals in the two POD configuration of FIG. 1 .
[0045] The POD processor 200 and the DSP 206 also communicate via a bus interface, 205 . Bus interface 205 is coupled to display 118 to enable processor 200 to provide status information, such as number dialed, caller ID and the like on the display 118 . A memory 230 , such as an electrically erasable programmable read only memory is coupled to bus interface 205 to store operating program instructions. The DSP reads and executes a program stored in memory 207 , which preferably is a flash memory module.
[0046] Status indicators 228 , preferably LED's, provide a visual indication of the POD status. In the preferred embodiment, green LED's indicate the unit is powered on and red LED's flash to indicate the POD microphones are muted. Preferably the POD includes a battery 209 to permit the wireless unit to be relocated to any convenient location. The batteries may be replaceable consumables, but to reduce spent battery waste, rechargeable batteries are preferred. A line powered recharge adaptor 211 produces recharge current that is supplied to the battery by a charge circuit 213 that controls battery recharging and prevents overcharging of the batteries. If desired, the green LED's may be flashed in various ways to provide a visual indication that the batteries are being recharged and/or are fully charged, or the charge status of the batteries may periodically be indicated on the POD display 118 .
[0047] FIG. 4 shows a schematic diagram of a preferred embodiment of an RF interface used in both the base 130 , and in each POD 204 for signaling paths to facilitate exchange of data and control of the RF modules 126 and 202 in the base and PODs by the corresponding processor 120 , 200 . In the RF interface, inputs supplied to the respective RF module include SYS_CLOCK which provides the basic clock for the RF module and is gated on and off when needed. The PLL_ENABLE, PLL_DATA, and PLL_CLOCK input signals are used to adjust and multiply the carrier frequency, for example to allow frequency hopping or channel selection to occur. The transmit inputs supplied to the respective RF modules include a TDO signal, which provides the transmit data output that will be encoded onto the wireless communications channel using a suitable modulation scheme, for example, GMSK modulation. The PWR_ON input is used to turn the RF power amplifier on and off. The PWR_SEL input is used to select a low or a high transmit power level. Preferably frequency hopping is used. On the receive side, the outputs from the respective RF modules include a received data in (RDI) signal corresponding to the data input received at the RF module and the RXDSG and RSSI signals are used to indicate the received signal strength.
[0048] The above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto. | A wireless conference phone system has a base station to couple at least one conference unit to a telephone network, such as the public switched telephone network (PSTN) or a digital telephone network such as a voice over internet protocol (VolP) network. Each conference unit performs echo cancellation of the audio signal received from a remote location allowing a simplified base station implementation | 7 |
This application is a continuation of U.S. Ser. No. 13/759,511, filed Feb. 5, 2013, which is a continuation of U.S. Ser. No. 12/266,951, filed Nov. 7, 2008, which claims the benefit of U.S. Provisional Application No. 60/986,483, filed Nov. 8, 2007, entitled “Wall Block With Weight Bearing Pads and Method of Producing Wall Blocks”, the contents of each of which are hereby incorporated by reference herein.
FIELD OF THE INVENTION
The present invention relates generally to concrete wall blocks. More particularly the invention relates to wide or oversized wall blocks having weight bearing pads and to compression head assemblies used during the process of manufacturing the wall blocks from a mold.
BACKGROUND OF THE INVENTION
Numerous methods and materials exist for the construction of retaining walls and landscaping walls. Such methods include the use of natural stone, poured in place concrete, masonry, and landscape timbers or railroad ties. In recent years, segmental concrete retaining wall units which are dry stacked (i.e., built without the use of mortar) have become a widely accepted product for the construction of retaining walls. Such products have gained popularity because they are mass produced, and thus relatively inexpensive. They are structurally sound, easy and relatively inexpensive to install, and couple the durability of concrete with the attractiveness of various architectural finishes.
It is desirable to build a wall from such blocks quickly and without the need for special skilled labor. The efficiency of building a wall can be measured by determining how fast the front face of a wall is constructed. Clearly, this depends on the size of the blocks used and ease of stacking the blocks.
It is standard practice in the prior art to use similarly sized mold boxes to produce various styles of block. For example, U.S. Patent Application Publication No. 2005/00161106 A1 entitled Method of Making Wall Block, the entirety of which is incorporated herein by reference, describes a standard size mold box of about 18 inches by about 24 inches (about 45.7 cm by about 61 cm), and about 8 inches (20.3 cm) deep. This standard size mold box is used to produce blocks of varying sizes. Since those blocks are typically formed in the mold with their front faces positioned along the 18 inch (45.7 cm) dimension these blocks have a front face with a dimension of 18 inches by 8 inches and a surface area of about one square foot (929 sq cm). The '106 application describes an improvement whereby two blocks are made in a standard size mold box with the front faces of the blocks formed along the 24 inch (61 cm) dimension. Those prior art blocks described in the '106 application are shown in FIG. 1 . The blocks 10 are shown as they are formed within a mold box 20 and each has a front face that is about 24 inches by 8 inches (45.7 cm by 20.3 cm) and an area of about 1.33 square feet (0.124 square meter). This is larger than typical prior art blocks formed two at a time in the same size mold box which have a front face area of one square foot (0.0929 square meter). A larger front face is advantageous because more useable wall surface area is produced each mold cycle and wall construction speed and efficiency is increased because it takes fewer blocks that must be handled and aligned by laborers to build the same size wall.
During the block molding process the mold box is used to form multiple blocks at one time. The mold and a lower plate or production pallet form a cavity for the formation of blocks. Moldable material such as concrete having a composition well known to those of skill in the art is placed into the mold and allowed to set for a time sufficient to allow retention of block shape when the material is removed from the mold box. Often the blocks are formed in the mold box with their lower surface facing up and their upper surface facing down and resting against the pallet. Unless otherwise noted, that is the block orientation which is used in this application. As is well known in the art the material is removed with the aid of a compression head assembly which is lowered from above the mold box and urges the material out of the mold. Once the material is removed from the mold the material in the form and shape of a block or blocks is moved to a curing station where the blocks are allowed to cure while resting on the pallet. Another pallet is positioned under the mold to receive the moldable material which again fills the mold. In this way, many sets of multiple blocks are formed with one mold and many pallets.
During the block molding process it is important that the blocks are made of a uniform and consistent shape and size and that block dimensions, especially block height or thickness, are maintained within acceptable tolerances. This is important for all blocks but especially those made for use in dry stacked walls. There are various ways that the acceptable range of tolerance of block dimensions can be exceeded during the block molding process. Excessive wear or misalignment of the equipment and machinery used in the manufacturing process can result in the production of blocks having one or more dimensions that do not fall within acceptable tolerances. For example, irregularities in height can be the result of the blocks being formed on production pallets which have irregular surfaces. Production pallets can be made of various materials including steel, plastic and wood. Any irregularity in the surface of the production pallet will be imparted to blocks formed on that surface. Although this application focuses on problems caused by the use of fatigued and sagging production pallets it should be understood that the concepts disclosed herein are generally applicable to control tolerances and especially height/thickness tolerances of any wall block caused by any reason.
The size of a typical production pallet used in the block molding process is from 18 inches by 26 inches (46 cm by 66 cm) for the smallest pallet to 44 inches by 55 inches (112 cm by 140 cm). When the pallets are new the surface upon which the blocks are formed and cured is planar and level. The block surface resting against the pallet (typically the top surface of the block) is also planar and level since it assumes the contour of the surface of the pallet upon which it cures. However, older pallets which have been used in many production cycles can begin to sag. A block which is formed and cured on a sagging pallet or on a pallet having an irregular surface for other reasons will assume the contour of the pallet. Thus, the block will be formed with a top surface which is not planar. It is desirable that the dimensions of blocks made during this process are maintained within acceptable tolerances and that surfaces which are meant to be level are, in fact, level. This is especially true of blocks which are made with the intention that they will be dry stacked. In a wall where the blocks are connected with mortar it is possible to correct for misshapen blocks (blocks which do not fall within acceptable tolerances) by using more or less mortar. However, such correction is not possible in a dry stacked wall. If the blocks are small and the walls constructed with the blocks are not too high irregularities in block height created during the molding process may not affect use of the blocks. However, the problem is amplified in larger, wider blocks and blocks used to construct very tall walls. As discussed previously, the size and width of blocks varies depending on the size of the mold and the orientation of the blocks in the mold. For example, the width of blocks may range from less than one foot to two feet.
FIG. 2A is a front view of a prior art block 10 a similar to those shown in FIG. 1 . Block 10 a is shown resting on a level pallet 30 while it cures. It can be seen that the top surface of block 10 a which rests on the pallet is level. FIG. 2B is a front view of block 10 b which is similar to the blocks shown in FIG. 1 except it is resting on a sagging pallet 40 while it cures. The drawing, which is somewhat exaggerated to make the concept clear, shows that the pallet may sag by a distance d which has been measured to be between about ⅛ inch to 3/32 inch (0.3 cm to 0.2 cm) at each end on pallets that have been in use for some time. The top surface of block 10 b , which rests against the pallet, is formed with a curve or bow which results in the thickness of the block being greater at the center portion of the block than at the ends. This curve or bow in the block corresponds to the sag of the pallet causing the middle portion of the top surface to be higher than the ends by between about ⅛ inch to 3/32 inch (0.3 cm to 0.2 cm).
FIG. 3A shows a portion of a wall constructed with blocks 10 a formed on a level pallet as shown in FIG. 2A . FIG. 3A shows that the thickness of the blocks is uniform and the tops and bottoms of the blocks in each course are level. The bottom surface of blocks in each course of blocks in the wall abuts against the top surface of the blocks in the next lower course without any gaps or areas of concentrated stress. This is the situation which is desired when the blocks are formed. FIG. 3B shows a portion of a wall constructed with blocks 10 b formed on a sagging pallet as shown in FIG. 2B . This drawing is not to scale but is exaggerated to clearly show the increased block thickness at the middle portion of the blocks. The raised middle portion of the top surface of the blocks 10 b is clearly visible. Unlike the wall of FIG. 3A the wall in FIG. 3B has areas of concentrated stress S at the top middle portion of each block in a lower course of blocks. The stress areas S are created where the raised middle portion of the top surface of the blocks contacts the blocks in the course of blocks above. FIG. 3B also shows that the portion of the block immediately below the areas of stress do not contact the blocks in the course below because that location is directly above the end portions of blocks in the lower course when the wall blocks are placed in a running bond pattern which is common when building landscape or retaining walls. The blocks are thinner at the end portions resulting in gaps between courses at those locations. Since there are gaps between the courses of blocks directly under the areas of concentrated stress there is no support provided by the underlying course of blocks at those areas. The result is that when the height of the wall is enough to create a downward force at the areas of concentrated stress S greater than the strength of the block to resist that stress without support from below a crack C can develop. The number of cracks which form in the face of the wall depends on the size of the blocks, the amount of the sag or curvature or thickness variation of the blocks, and the height of the wall. Cracks in the wall make the wall less aesthetically pleasing and, in extreme cases, if there are enough cracks can even affect the structural integrity of the wall.
Accordingly, there is a need in the art to compensate or correct for the dimensional intolerances which are created for various reasons during the block molding and curing process.
SUMMARY OF THE INVENTION
The present invention is directed generally at masonry wall blocks having weight bearing pads on an upper or lower surface and to methods of making such blocks. In one embodiment the invention is a wall block having a plurality of weight bearing pads on an upper or lower surface of the block. In another embodiment the invention is a compression head assembly having tamper heads which are used to form weight bearing pads on the upper or lower surface of a wall block during the block molding process. The invention also includes the blocks made with the compression head assembly and walls made from those blocks. The invention also includes a method of constructing a block wall from the blocks made from the compression head assembly. The invention also includes a method of leveling a surface of a block during the block forming process. This method includes measuring the block specifications during the forming process and removing material from a surface of the block or a portion of a surface of a block to level that portion of the surface of the block.
The invention provides a wall block comprising a block body having opposed front and rear faces, opposed first and second side surfaces, and opposed and substantially parallel upper and lower surfaces, at least one weight bearing pad extending from one of the upper and lower surfaces. In one embodiment, the weight bearing pad extends from the lower surface. In an embodiment, the block body comprises two weight bearing pads, and in another embodiment the block body comprises just two weight bearing pads. In an embodiment, the at least one weight bearing pad extends substantially from the rear face to the front face of the block body. In an embodiment, the at least one weight bearing pad is a rectangular prism. In one embodiment, the at least one weight bearing pad has a height of from ⅛ to ½ inch (0.3 to 1.3 cm), and in another embodiment the at least one weight bearing pad has a height of from ⅛ to ⅜ inch (0.3 to 1.0 cm). In an embodiment, the dimensions of the at least one weight bearing pad are from 1 to 3 inches (2.5 to 7.6 cm) wide, 7 to 11 inches (17.8 to 27.9 cm) long, and ⅛ to ⅜ inch (0.3 to 1.0 cm) deep. The at least one weight bearing pad can be level or have a slope.
The invention provides a compression head assembly for use in making wall blocks comprising: a stripper shoe including a bottom portion having at least one opening; and at least one adjustable tamper head sized to be accommodated within the at least one opening in the stripper shoe. In an embodiment, the at least one adjustable tamper head can be raised and lowered relative to the stripper shoe. In an embodiment, the at least one adjustable tamper head can be set at an angle relative to a horizontal plane of the stripper shoe. In one embodiment, the at least one adjustable tamper head can be set at an angle of from 0 to 5 degrees.
The invention provides a compression head assembly for use with a mold in making wall blocks comprising a stripper shoe including a bottom portion for contacting a wall block surface in the mold, the bottom portion having at least one indentation for imparting to the wall block surface at least one raised weight bearing pad.
The invention provides a method of making a plurality of retaining wall blocks comprising providing a mold assembly including a pallet, a compression head assembly, a mold box having at least one mold cavity having an open mold cavity top and an open mold cavity bottom, the mold cavity being shaped to form a single retaining wall block, each retaining wall block having opposed front and rear faces, opposed first and second side surfaces, and opposed and substantially parallel upper and lower surfaces, and at least one weight bearing pad extending from one of the upper and lower surfaces, the compression head assembly comprising a stripper shoe including a bottom portion having at least one opening and at least one adjustable tamper head sized to be accommodated within the at least one opening in the stripper shoe; positioning the pallet beneath the mold box to enclose the mold cavity bottom; filling the mold cavity with dry cast concrete; lowering the compression head assembly to enclose the open mold cavity top and compress the dry cast concrete within the mold cavity, the at least one weight bearing pad being formed adjacent the at least one adjustable tamper head; and lowering the pallet and the compression head assembly to strip the dry cast concrete from the mold cavity.
The invention provides a method of making a plurality of retaining wall blocks comprising providing a mold assembly including a pallet, a compression head assembly, a mold box having at least one mold cavity having an open mold cavity top and an open mold cavity bottom, the mold cavity being shaped to form a single retaining wall block, each retaining wall block having opposed front and rear faces, opposed first and second side surfaces, and opposed and substantially parallel upper and lower surfaces, and at least one weight bearing pad extending from one of the upper and lower surfaces, the compression head assembly comprising a stripper shoe including a bottom portion for contacting a wall block surface in the mold, the bottom portion having at least one indentation for imparting to the wall block surface the at least one raised weight bearing pad; positioning the pallet beneath the mold box to enclose the mold cavity bottom; filling the mold cavity with dry cast concrete; lowering the compression head assembly to enclose the open mold cavity top and compress the dry cast concrete within the mold cavity, the at least one weight bearing pad being formed adjacent the at least one indentation; and lowering the pallet and the compression head assembly to strip the dry cast concrete from the mold cavity.
The invention provides a retaining wall comprising a plurality of courses of retaining wall blocks including a first upper course and a second lower course, each retaining wall block having opposed front and rear faces, opposed first and second side surfaces, and opposed and substantially parallel upper and lower surfaces, and at least one weight bearing pad extending from one of the upper and lower surfaces. In an embodiment, the weight bearing pads in the first upper course and the second lower course are vertically aligned. In one embodiment, the weight bearing pad extends from the lower surface.
The invention provides a method of leveling a wall block comprising providing a wall block comprising a block body having opposed front and rear faces, opposed first and second side surfaces, and opposed and substantially parallel upper and lower surfaces, at least one weight bearing pad extending from one of the upper and lower surfaces; and removing a portion of the at least one weight bearing pad to make the height of the wall block equal to an adjacent block in a course of a retaining wall.
The invention provides a mold box for making first and second wall blocks comprising first and second opposed end rails and first and second opposed side rails, the end rails and side rails together forming a mold box; a divider plate having a first end connected to the first end rail and a second end connected to the second end rail, the divider plate dividing the mold box into a first mold section for forming the first block and a second mold section for forming the second block; and pin hole molding portions attached to the divider plate.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a mold box configuration for Prior Art blocks.
FIG. 2A is a front view of the blocks shown in FIG. 1 curing on a level pallet. FIG. 2B is a front view of the blocks shown in FIG. 1 curing on a sagging pallet.
FIG. 3A is a front view of a portion of a wall constructed with the blocks of FIG. 2A . FIG. 3B is a front view of a portion of a wall constructed with the blocks of FIG. 2B .
FIG. 4 is a perspective view of a compression head assembly having adjustable tamper heads according to a first embodiment of the invention.
FIG. 5A is a bottom plan view of the compression head assembly of FIG. 4 .
FIG. 5B is a bottom perspective view of the compression head assembly of FIG. 4 .
FIG. 5C is a top perspective view of the compression head of FIG. 4 .
FIG. 6 is a front view of the compression head assembly of FIG. 4 positioned over a wall block mold box and production pallet.
FIG. 7 is a top view of wall blocks removed from the mold of FIG. 6 and curing on a pallet.
FIG. 8 is a perspective view of one of the blocks shown in FIG. 7 .
FIG. 9 is a front view of a portion of a wall built with blocks shown in FIGS. 7 and 8 .
FIG. 10 is a front view of a wall block which has been modified in accordance with a further embodiment of this invention.
FIG. 11 is a plan view of a mold box showing a divider plate.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In this application, “upper” and “lower” refer to the placement of the block in a retaining wall. The lower surface faces down, that is, it is placed such that it faces the ground. In forming a retaining wall, one row of blocks is laid down, forming a course. A second course is laid on top of this by positioning the lower surface of one block on the upper surface of another block.
The blocks of this invention may be made of a rugged, weather resistant material, such as concrete. Other suitable materials include plastic, reinforced fibers, and any other materials suitable for use in molding wall blocks. The surface of the blocks may be smooth or may have a roughened appearance, such as that of natural stone. The blocks are formed in a mold and various textures can be formed on the surface, as is known in the art. Although the embodiments described herein are discussed with reference to a wall block having a front width of 24 inches it should be appreciated that the invention is equally applicable to blocks of all sizes including those whose front faces are either larger or smaller than the ones referenced herein.
As described above due to worn or misaligned equipment used in the block manufacturing process various dimensional intolerances and surface irregularities can be unintentionally imparted to the block. More specifically as described in connection with FIGS. 1 to 3 , production pallets which have gone through numerous mold cycles tend to fatigue over time and eventually start to sag. A sagging or otherwise irregular pallet imparts to the blocks the same dimensional intolerances as are present in the pallet. For many block styles and especially blocks which are meant to be used only to construct relatively low walls with few courses of blocks these dimensional intolerances do not create significant problems because the buildup of stress in areas of concentrated stress are not large enough to cause cracks in the wall. However larger blocks, because of their size, are more affected by these dimensional intolerances. Further, blocks used to construct large walls with many courses of blocks are more likely, because of the increased weight of the blocks used, to develop stresses which can cause blocks in the wall to crack. The present invention includes various embodiments that are meant to eliminate or reduce these areas of concentrated stress that are caused by dimensional intolerances which exist in the block molding process by forming on an upper or lower surface of the blocks a weight bearing pad.
FIG. 4 is a perspective view of a compression head assembly in accordance with one embodiment of the present invention. Compression head assembly 100 includes a stripper head plate 102 and a stripper shoe 106 comprising an upper portion 106 a and a lower portion 106 b . A plurality of stripper plungers 104 are attached between the stripper head plate 102 and the upper portion 106 a of the stripper shoe. For purposes of illustration a plurality of tamper heads 108 which may be adjustable in the manner described further below are shown disconnected from the compression head assembly 100 . When connected the tamper heads are received within compatible openings in the bottom of the lower portion 106 b of the stripper shoe as best seen in FIGS. 5A, 5B and 5C which are a bottom plan view of the stripper shoe and bottom and top perspective views of the compression head assembly, respectively. The tamper heads are provided for the purpose of forming weight bearing pads on a bottom surface of blocks which are formed in a block molding process using the compression head assembly in a manner which will be described in more detail hereafter.
The adjustable tamper heads 108 are attached to threaded shafts 110 . Shafts 110 are received in apertures in plates 115 . Plates 115 are connected between plungers 104 . The depth that the tamper heads are received into lower portion 106 b is set by adjusting nuts 112 and 114 to raise or lower shafts 110 . Each tamper head 108 pivots with respect to shaft 110 at pivot point 116 . The angle at which the tamper heads pivot or tilt is adjustable by using set screws 117 and 119 which are threaded into holes in the upper portion 106 a of the stripper shoe. By adjusting the depth by which set screws 117 and 119 extend into and through upper portion 106 a the angle of the tamper heads 108 can be adjusted in teeter totter fashion.
FIG. 6 is a front view of compression head assembly 100 positioned over a mold box 20 and pallet 120 during a block forming process. As known in the art the stripper shoe is discontinuous to avoid contact with any core bars or cores that may be used in the block forming process. Once the mold box has been filled with the moldable material and the material has been vibration compacted to hold its shape the compression head assembly is lowered to push the material out of the mold box. The material in the form of wall blocks remains on the pallet and is moved to a curing station.
FIG. 7 is a top view of blocks 200 formed in the process shown in FIG. 6 . Blocks 200 are shown resting on the pallet 120 in the curing station. The blocks 200 have front faces 210 that can have any texture and can have a bevel. The blocks also have rear faces 215 . The blocks 200 also have pin holes 220 and pin receiving cavities 230 . Pins are often placed in the blocks in the process of making a wall. Pin hole mold portions 250 are attached to a divider plate 260 , which is attached to the mold box 20 as shown in FIG. 11 .
Since the bottom surfaces of the blocks are oriented upwards in the mold, FIG. 7 shows the bottom surfaces of the blocks as they would be used in forming a wall. The adjustable tamper heads which are recessed into lower portion 106 b of the shoe impart to the bottom surface of each of the blocks a plurality of raised surfaces 122 which function as weight bearing pads. In this embodiment two weight bearing pads are formed but it should be understood that the number and position of the weight bearing pads can be varied. The amount by which each pad is raised from the bottom surface of the blocks depends on the extent of curvature or other irregularity that is imparted to the block by the pallet or other portion of the mold machinery or equipment. For example, if the pallet is fatigued and sags at each end by from 3/32 to ⅛ of an inch (0.2 to 0.3 cm) the adjustable tamper heads can be set to form the weight bearing pads to extend from the bottom surface of the block by up to ¼ inch (0.64 cm) or more if desired. During the block forming process adjustments to the adjustable tamper heads can be made based on measurements taken from blocks which have been previously made. These measurements may require that the amount that the weight bearing pads extend from the blocks be increased or decreased. This is done by adjusting the amount by which the tamper heads are recessed into lower portion 106 b of the stripper shoe. Further, it may be desirable to increase or decrease the amount by which the pads are angled or sloped from the front of the blocks to the back. This angle may be adjusted in the range of from about 0° to 5°. A perspective view of one of the blocks 200 is shown in FIG. 8 . Although the compression head assembly is shown in the drawings as including four adjustable tamper heads which form two weight bearing pads 122 on each block it will be apparent to those of skill in the art that more or fewer tamper heads could be used to form more or fewer weight bearing pads on each block depending on how many blocks are formed in the mold box, the size of the blocks, use requirements, and on the desired amount of weight distribution points. Further, although the tamper heads are shown as being adjustable both in the depth they are recessed into lower portion 106 b and in their slope it should be understood that the tamper heads could be made adjustable only as to amount of recess or only as to degree of slope. Further, the tamper heads need not be adjustable at all. In fact the tamper heads need not be separate components from the stripper show but may comprise recesses formed into the bottom surface of lower portion 106 b to a depth in the range of about ⅛″ to ⅜″ (0.3 to 1 cm). Further, although in the manufacturing process described herein the bottom surfaces of the blocks face upward in the mold box it is also possible to form wall blocks with the upper block surface facing upwards so that the weight bearing pads may be formed on either the upper or lower block surface depending on how the block is oriented in the mold.
FIG. 9 is a front view of a wall constructed in an overlapped or running bond pattern with the blocks of FIGS. 7 and 8 . As can be seen each course of blocks contacts an adjacent lower course of blocks only at weight bearing pads 122 . Thus, the weight of the blocks from upper courses of blocks is applied only at the locations of the weight bearing pads 122 . The pads are positioned on the blocks so that these load or stress areas are formed directly above a weight bearing pad on the underlying block. In other words, when a wall is formed from the blocks 200 in a running bond pattern as shown in FIG. 9 the pads in each course align vertically along lines Y. Since there are no areas of high stress that do not have underlying support, the problem of block cracking is eliminated even if the block thickness is not consistent within an acceptable range as may be caused by worn, misaligned or irregular equipment or machinery used in the block molding process.
FIG. 10 illustrates a further embodiment of the invention which illustrates a method of leveling a portion of a surface of a wall block. In this embodiment a block 300 is provided with weight bearing pads 122 . Weight bearing pads 122 are formed in the molding process using a stripper shoe having a recessed tamper head as described above. However, for purposes of this embodiment the tamper heads may be separate components which are adjustable as described above or they may be recesses formed into the bottom surface of lower portion 106 b for which no adjustment is possible. They may be recessed by a desired amount, for example, ¼ inch (0.64 cm). Once the blocks have been formed with the weight bearing pads the height of those pads may be adjusted, if necessary, based on measurements taken after the blocks have been formed. The height adjustment is made by grinding, planning or otherwise removing a portion of the weight bearing pads shown as cross-hatched in FIG. 10 so that the block height at those locations is consistent from block to block. This is advantageous since it is not necessary to control the height of the block at all locations but only at the location of the weight bearing pads. In other words, the block need only be formed with standard sized weight bearing pads which are then mechanically adjusted if necessary to maintain correct height tolerance for the block by removing or planning an appropriate amount of material from only the weight bearing pad. Shims could also be used in this process.
Although particular embodiments have been disclosed herein in detail, this has been done for purposes of illustration only, and is not intended to be limiting with respect to the scope of the following appended claims. In particular, it is contemplated by the inventor that various substitutions, alterations, and modifications may be made to the invention without departing from the spirit and scope of the invention as defined by the claims. For instance, the choices of materials or variations in shapes are believed to be a matter of routine for a person of ordinary skill in the art with knowledge of the embodiments disclosed herein. Further, although the invention has been described in connection with blocks having height inconsistencies or intolerances due to forming the blocks on a sagging pallet it should be understood that these inventive concepts and embodiments are also applicable to control height tolerances on any block having height inconsistencies caused by any reason. | A retaining wall having a plurality of courses of retaining wall blocks including a first upper course and a second lower course. Each retaining wall block has opposed front and rear faces, opposed first and second side surfaces, and opposed and substantially parallel upper and lower surfaces, and at least one weight bearing pad extends from one of the upper and lower surfaces. The at least one weight bearing pad extends substantially from the rear face to the front face of the block. The weight bearing pads are the only areas of contact between the blocks in the first upper course and the blocks in the second lower course. | 4 |
FIELD OF THE INVENTION
The invention relates to a support for a machine tool spindle adapted for use with a cooling device in a headstock, in which a fluidic cooling medium is fed through feed and discharge channels, which extend parallel with respect to the spindle axis, to the inner bearing rings of the spindle bearings.
BACKGROUND OF THE INVENTION
In machine tools, the spindles of which rotate at a high speed, heat is generated in the roller bearings due to bearing friction, which heat is transmitted both onto the spindle and also onto the headstock. Due to an uneven temperature distribution in the bearing parts and the spindle, there results a shifting of the working or machining tools in direction of the spindle axis and radially of the axis of rotation of the tools, thereby rendering inexactnesses in the machining process. It is therefore common to forcedly cool the roller bearing outer rings by means of a cooling device. A cooling of the outer bearing rings, however, is not sufficient in view of the present demand for higher speed ranges and increasing requirements for precision. Only a very small portion of the heat which accumulates at the inner bearing rings can be discharged by a cooling of the outer bearing rings.
In order to also discharge heat from the inner bearing rings, a bearing sleeve which encloses the outer bearing rings is provided in a support for a machine tool spindle adapted for use with a cooling device of the above-mentioned type (German OS No. 19 57 974). The bearing sleeve has an axially parallel feed channel which, in the area of the roller bearings, is connected through crossbores to the inside of the roller bearings. The bearings sleeve has furthermore a discharge channel for the cooling medium which, near the spindle head, enters from the inside of the roller bearings into an annular chamber connected to the discharge channel. Lubricant oil is used as the cooling medium and is fed by means of a pump through the feed channel to the inside of the roller bearings. The lubricant oil in this manner reaches directly the inner bearing rings and also the outer bearing rings. The lubricant flows successively through the various roller bearings until it finally flows into the annular chamber, which is provided on the spindle head, and flows back from same through the discharge channel and an oil cooler into a storage container. This apparently simple solution is, however, in view of the cooling action little effective. That is, the roller members which rotate at a high speed create an oil foam which consists of oil and air, which oil foam is little suited for effecting a discharge of the heat. Furthermore, through the turbulence of the oil on the inside of the roller bearings heat is generated which in turn increase the amount of the accumulating heat. Since a satisfactory heat discharge cannot be assured in this known support, an additional correcting device is provided which controls the axial position of the spindle in response to its temperature. Such a correcting device, however, assumes that a bearing sleeve is axially movable in the headstock and furthermore complicated control devices are needed.
The basic purpose of the invention is to provide a machine tool spindle adapted for use with a cooling device in a headstock of the above-mentioned type, which is of a simple design and assures a satisfactory heat discharge from the inner bearing rings and thus secures a high operating speed and a simultaneous increase in the lifespan of the roller bearings.
This purpose is attained according to the invention by the feed and discharge channels being provided in the spindle and being connected with cooling grooves which, at least in the region of the inner bearing rings are arranged on the spindle head and extend in a peripheral direction or helically, are worked into the spindle outer surface and are open toward the inner bearing rings.
Through these relatively simple measures, a good lost heat discharge from the hub area of the inner bearing rings is assured. Since the cooling medium is guided through the cooling grooves to the inner bearing rings, it does not contact the roller members and, as a result, a foaming of the cooling medium is prevented, so that same can develop its full cooling action. Through a satisfactory heat discharge of the lost heat from the inner bearing rings, a heat transfer onto the spindle and its bearing parts is avoided and thus a high operating precision is also assured. Compared with supports adapted for use with a cooling device in which only the outer bearing rings are cooled, the inventive support also has a better cold-start behavior, because possible heat expansions do not need to be considered in measuring the bearing clearance. Finally, a good heat discharge from the inner bearing rings also leads to an increase in the life of the roller bearings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be discussed in greater detail with reference to the exemplary embodiments which are illustrated in the drawings, in which:
FIG. 1 is an axial cross-sectional view of a first exemplary embodiment; and
FIG. 2 is an axial cross-sectional view of a second exemplary embodiment.
DETAILED DESCRIPTION
The machine tool spindle 1 is rotatably supported in a headstock 3 near its spindle head 1a by means of several roller bearings 2. Gauge rings 5, which rotate with the spindle 1, are provided between each of the inner bearing rings 2a of two mutually adjacent roller bearings and between the endmost inner bearing rings 2a and the parts 1a and 4. Each of the gauge rings 5 have, in this exemplary embodiment, on their axially facing surfaces, which surfaces engage the axially facing surfaces on adjacent inner bearing rings 2a, annular grooves in which are provided gasket rings 6.
The hub 7 of a bevel gear 8 is fixedly mounted on the inner end of the rotatable spindle 1. The bevel gear 8 is driven by another bevel gear 9. The bevel gear hub 7 is supported by roller bearings 10 and an intermediate sleeve 11 in the headstock 3.
Two axially parallel channels, namely, a feed channel 12 and a discharge channel 13 are provided in the spindle 1 and are offset or arcuately spaced at 180° with respect to one another.
Cooling grooves 14 are provided in the outer surface 1b of the spindle 1 in the region of the inner rings 2a, which inner rings 2a are provided near the spindle head 1a. The cooling grooves 14 extend helically in this exemplary embodiment and preferably have a rectangular cross section. The grooves 14 can, if necessary, however, also have a trapezoidal or semicircular cross section. The cooling-medium grooves 14 are open radially outwardly toward the inner bearing rings 2a. The exiting of cooling medium into the inside of the roller bearings 2 is prevented by the gasket rings 6.
In order for flow to occur through the cooling grooves 14 in the counter-flow principle, the cooling groove 14a which is the closest to the spindle head 1a is connected to the feed channel 12 through a connecting bore 15. The cooling groove 14b most remote from the spindle head 1a is connected to the discharge channel 13 through a connecting bore 16. The discharge channel discharges at the point 13a into the gear transmission housing.
The spindle 1 is encircled by a sleeve 17 at the upper end of the feed channel 12 to define an annular chamber 18 between a portion of the sleeve 17 and the spindle. The sleeve 17 has an inlet bore 19 therein which is connected to a not illustrated cooling-medium pump with integrated cooler. The sleeve 17 encloses at its two ends 17a and 17b the outer surface of the spindle in such a manner that a hydrostatically acting sealing gap is formed between the outer surface of the spindle and the sleeve 17. In place of the sleeve 17 it could also be possible to provide any desired other feed mechanism which makes possible the supply of a fluidic medium from a stationary part to a rotating part. For example the cooling-medium supply could also occur on the front side at the inner end of the spindle 1. Also it would be conceivable, that the cooling-medium discharge occurs through a sleeve similar to the sleeve 17. However, it is simpler to permit the discharge channel 13 to discharge into the gear transmission housing. The condition for this is that transmission lubricant is used as the cooling medium. The cooling medium is again fed from the gear housing 20 through the cooler to the not illustrated pump.
The frictional heat which is created at the inner rings 2a of the roller bearings is continuously discharged through the cooling medium which directly interfaces with the inner rings 2a, so that a heating up of the spindle 1 is impossible and, also at high spindle speeds, the precision working characteristic is maintained. Pressure and/or amount and temperature of the cooling medium which is fed through the feed channel 12 and the cooling grooves 14 to the inner rings are regulated in accordance with a command variable, preferably the room temperature, so that the temperature of the spindle, measured at a representative measuring point, corresponds, as much as possible, exactly with the room temperature.
The cooling of the outer rings 2b of the roller bearings occurs in a common manner by means of a cooling medium fed through a feed bore 21 provided in the headstock 3 to cooling grooves 22 provided in an intermediate sleeve 23 which surrounds the outer rings 2b. The heated-up cooling medium is discharged through the outlet bore 24. The upper roller bearings 10 are cooled in a similar manner by cooling medium which flows through the cooling medium grooves 25 in the intermediate sleeve 11. If necessary, it is also possible to cool the inner rings of the roller bearings 10 in a similar manner, as this was described with respect to the inner rings 2a of the lower roller bearings 2. However, the drive of the spindle should then occur above the upper roller bearings 10.
The exemplary embodiment which is illustrated in FIG. 2 corresponds in important parts with the exemplary embodiment which is illustrated in FIG. 1, for which reason the same reference numerals have been used and the above description is accordingly pertinent. In the exemplary embodiment which is illustrated in FIG. 2, there is, however, arranged between the inner rings 2a of the roller bearings and also between the gauge rings 5 and the spindle outer surface 1b a thin-wall sleeve 26 of a good heat-conducting material. This thin-wall sleeve 26 prevents the exiting of the cooling medium into the inside of the roller bearing, so that the gasket rings 6 are not needed. The heat flow from the inner rings 2a is hardly influenced by the thin wall of the sleeve 26 and its good heat conductivity.
Furthermore, the cooling grooves 14' which are worked into the spindle outer surface 1b are in this case not arranged helically, but are constructed as peripherally extending grooves. Each of the cooling grooves 14' is thus closed in itself. The individual cooling grooves 14' are connected with one another through axial connecting grooves 27. In order for the cooling medium to indeed completely flow through the cooling grooves 14', it is advantageous if the connecting grooves 27 are arranged alternately offset at 180° with respect to one another. | In a support for a machine tool spindle (1) adapted for use with a cooling device there are provided feed and discharge channels (12, 13) for a fluidic cooling system in the spindle (1). These channels are connected to cooling grooves (14), which at least in the region of the inner bearing rings (2a) are arranged on the spindle head (1a), are worked into the spindle outer surface (1b) extending in a peripheral direction or helically and are open toward the inner bearing rings (2a). | 8 |
TECHNICAL FIELD
This invention relates to automotive vehicle door hardware including a single piece cable regulator assembly, a latch carrier assembly and a window carrier assembly.
BACKGROUND OF THE INVENTION
Conventional automotive vehicle door hardware, including cable regulators and latch and window carriers are characterized by a large number of parts and inflexible assembly procedures. Cable regulators alone may include ten or more parts. After assembly of such parts, a latch carrier assembly, including a door handle, a door latch and connecting rod hardware, is commonly inflexibly fastened to the cable regulator. The inflexible combination of the cable regulator and latch carrier, which typically must be delivered as a package for assembly into a vehicle door, is unwieldy and requires special handling procedures, adding to process costs. Such a cumbersome combination can be difficult to install into the interior of the door, leading to large door openings and complex assembly procedures.
Vehicle door hardware having a reduced number of parts, and providing for ease of shipping and assembly would therefore be desirable.
SUMMARY OF THE INVENTION
The present invention is directed to low cost, durable vehicle door hardware providing for ease of handling, shipping and assembly into a vehicle door. More specifically, the hardware includes a one piece cable regulator including integral window regulator cable guides, shields, and grooves molded thereon. In accord with a further aspect of this invention, a window bottom stop is molded on the one-piece cable regulator in the form of a compliant cantilevered beam. The bottom stop is positioned to contact and to be deflected by a window passing through a bottom window position and, through an opposing deflection force imparted to the window, gradually decelerate the window to a stop.
In accord with yet a further aspect of this invention, the cable regulator includes integral guides sized to slideably receive corresponding guides on a latch carrier mechanism for a slideable coupling of the latch carrier mechanism and the cable regulator, forming a flexible door hardware assembly. The relative position of the cable regulator and the latch carrier mechanism may then be adjusted during shipping and assembly to ease packaging and process constraints. A relatively compact assembly may be provided by shifting the latch carrier mechanism over the cable regulator, which may be efficiently shipped, handled and inserted into the vehicle door. When convenient, such as following insertion into the vehicle door, the latch carrier may be shifted outward from the cable regulator to an extended position required for final assembly within the door. In accord with still a further aspect of this invention, the vehicle door hardware includes a window carrier assembly mounted to the frame of the cable regulator and having tensioning springs which allow a significant amount of window cable lash take-up over a relatively small amount of space.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be best understood by reference to the preferred embodiment and to the drawings in which:
FIG. 1 is a perspective view of an installation of the vehicle door hardware of the preferred embodiment including a single piece cable regulator assembly, door latch carrier assembly and window carrier assembly into a vehicle door interior cavity;
FIG. 2 is a perspective view of an arrangement of the vehicle door hardware of FIG. 1 in a convenient assembly and shipping orientation;
FIG. 3 is a perspective view of an arrangement of the vehicle door hardware of FIG. 1 shifted from the orientation of FIG. 2 to a final assembly body position orientation;
FIG. 4 is an exterior perspective view of the vehicle door hardware of FIG. 3;
FIG. 5 is an enlarged perspective view of an upper portion of the vehicle door hardware of FIG. 2, with a portion of the cable regulator assembly of FIG. 2 cut away to illustrate further detail of the window carrier assembly of the preferred embodiment; and
FIG. 6 is a top cutaway view of the window carrier assembly of FIG. 5 taken along reference 6--6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a cutaway perspective view of an installation of door hardware in interior recess 14 of an automotive vehicle door 10 generally illustrates a latch carrier assembly 12 with interior door handle assembly 18, door latch assembly 22 and operating rods 20 extending between the door handle assembly 18 and the door latch assembly 22. FIG. 1 is an interior view from the direction of an interior of an automotive vehicle on which the door 10 is installed. The latch carrier assembly 12 is slideably mounted on a molded single piece cable regulator assembly 16 which is bolted to the door 10. A window carrier assembly 26 is slideably associated with the cable regulator assembly 16 for carrying a glass window panel (not shown). The single piece cable regulator assembly 16 is molded from a glass-reinforced plastic material, such as Petra 110. The latch carrier assembly 12 may be molded from any conventional plastic material. The window carrier assembly 26 is formed from extruded aluminum with molded plastic elements, to be described, secured thereto in any suitable conventional manner. The latch carrier assembly 12 is shown in an assembly position in FIG. 1 shifted over the cable regulator assembly 16 reducing overall package size to facilitate delivery of the combination of latch carrier assembly 12 and cable regulator assembly 16 to the site for final assembly, and to facilitate insertion of the combination into the interior recess 14 of the door, reducing complexity and time of assembly, and beneficially reducing the required size of a machined door opening (not shown) through which the combination must be inserted during assembly.
Referring to FIG. 2, an enlarged perspective view of the door hardware of FIG. 1 in the assembly position details the combination of the cable regulator assembly 16 with window carrier assembly 26 and latch carrier assembly 12 having interior door handle assembly 18 operatively connected to door latch assembly 22 via operating rods 20. The view of FIG. 2, as well as the view of FIGS. 1 and 3 is an interior view, taken from the direction of the interior of the automotive vehicle (not shown) on which the hardware is installed, with the door 10 of FIG. 1 in a closed position. The latch carrier assembly 12 is illustrated in an assembly position wherein a substantially straight lower edge or guide 24 of the latch carrier assembly 12 is slideably inserted along a latch guide in the form of a channel formed between an aligned row of spaced outer teeth 50 and an aligned row of spaced inner teeth (not shown), the outer and inner teeth upwardly protruding from shelf 51, with the outer and inner teeth and the shelf molded into the single piece cable regulator assembly 16 of this embodiment. The spacing between the row of outer teeth 50 and the row of inner teeth is slightly greater than the width of the lower edge 24 of the latch carrier assembly 12 providing that the outer and inner rows of teeth will securely maintain the latch carrier assembly in position relative to the cable regulator assembly 16 throughout delivery of the combination thereof and throughout the assembly process.
Stud 114 protrudes from a beam 54 (FIG. 4) of the cable regulator assembly 16 and is generally of a "T" shape, with a neck extending outwardly from the cable regulator assembly 16 and terminating in a flat head (not shown in FIG. 3). The stud 114 is positioned to be inserted through a corresponding hole 112 in the latch carrier assembly 12 during an assembly process, with the hole opening into a relatively narrow slot 110 along the latch carrier assembly 12. The hole 112 is of slightly greater cross-section than the head of the stud 114, the cross section of the head of the stud 114 significantly exceeds the width of the slot 110 so as to overlap the slot width, and the neck (not shown) of the stud is sized to fit within the slot 110. Such an arrangement allows for insertion of the stud 114 through the hole 112 during an assembly process and a shifting of the latch carrier assembly 12 relative to the cable regulator assembly 16 in direction to allow the head of stud 114 to slide over the slot 110, with the neck of the stud sliding within the slot while the lower edge 24 of the latch carrier assembly 12 slides between the aligned rows of teeth 50 and 52. The result is a secure engagement of the latch carrier assembly 12 and cable regulator assembly 16 with slideable cooperation therebetween throughout the assembly process to provide packaging benefits in accord with an important aspect of this invention. A mounting hole 86 passes through the cable regulator assembly 16 and a corresponding mounting hole 88 passes through the latch carrier assembly 12. The holes 86 and 88 are in position to be aligned when the latch carrier assembly 12 is shifted away from the cable regulator assembly 16 to a final assembly orientation as will be described, with a single attachment element, such as a screw, passing through the holes 86 and 88 to further secure the latch carrier assembly 12 relative to the cable regulator assembly 16. The described assembly orientation of the latch carrier assembly 12 and cable regulator assembly 16 reduces the overall package size of the combination, facilitating delivery and assembly thereof into the door, as described. Window carrier assembly 26 is shown at an upper end 16a of the cable regulator assembly 16 and includes integral seats 40 and 42 for receiving a glass panel (not shown). A vertical guide 44 is molded along the length of the cable regulator assembly for slideable insertion into at least one window carrier slot (not shown in FIG. 2) molded into the window carrier assembly 26. A slotted guide 45 is molded into the window carrier assembly 26 in position to receive an edge 17 of the cable regulator assembly 16 and to slide along the edge 17 as the guide 44 slides along the window carrier slot or slots, thereby substantially restricting relative motion of the window carrier assembly 26 relative to the cable regulator assembly 16 to a single degree of freedom.
A window drive mechanism or device in the form of a rotary actuator 80 of the DC motor or DC brushless motor type is secured to the cable regulator assembly 16 via clamps 84 and spring clips 83, with the clamps molded into the cable regulator assembly 16 and the spring clips secured thereto in any suitable conventional manner. The actuator 80 includes an output shaft 82 linked, such as through a standard ring and pinion assembly (not shown) to a cable drive bobbin 60 to rotationally drive the bobbin in response to manual drive commands issued by a window operator. A first and second section of a coated cable (not shown), such as in the form of a steel braided cable having a nylon coating, terminate at first ends in the window carrier assembly 26 with second cable ends, opposing the first cable ends, secured to and wound in opposite directions around bobbin 60. A channel 58 is molded into the cable regulator assembly 16 about at least a portion of its periphery, providing a guide path for the first and second coated cable sections.
The first and second cable sections are positioned during an assembly process to extend between the window carrier assembly 26 and the bobbin 60 along the channel 58. Rotation of the bobbin 60 in response to manual drive commands draws in and winds one of the cable sections around the bobbin 60 while extending and unwinding the other of the cable sections, allowing the coated cable sections to slide along the channel 58 to raise or lower the window carrier assembly 26. In accord with an important aspect of this invention, the channel 58 forming the cable guide path is molded into the single piece cable regulator assembly, such as through a gas assist molding process, reducing part count, decreasing manufacturing cost and complexity, and increasing durability.
FIG. 3 illustrates a perspective view of the combination of the cable regulator assembly 16 with window carrier assembly 26 and latch carrier assembly 12 of FIG. 3, but with the latch carrier assembly 12 shifted out from the cable regulator assembly 16 to the final assembly position. For example, the latch carrier assembly 12 may be shifted to the final assembly position after the cable regulator assembly 16 has been secured to a door panel through a suitable assembly process via assembly holes 96, contributing to a convenient procedure for inserting a compact package into an opening of a door, and for flexibility in positioning the latch carrier assembly 12 while the process of securing the cable regulator assembly 16 is taking place.
The final assembly position is provided for by pulling the latch carrier assembly 12 to an extended position protruding outward from the cable regulator assembly 16, with the neck (not shown) of stud 114 sliding along the slot 110 in a direction away from the hole 112 and with the lower edge 24 sliding between the aligned row of spaced inner teeth 52 and the aligned row of spaced outer teeth 50, the teeth protruding upwardly from the shelf 51. In such final assembly position, the holes 86 and 88 are aligned and an attachment element, such as a screw passes through the holes and is driven to a threaded receptacle in the door (not shown). The latch carrier assembly 12 may be positioned on an interior side of an inner door sheet metal panel (not shown), and the cable regulator assembly 16 may be positioned on an exterior side of the inner door sheet metal panel opposing the interior side thereof, whereby upon securing the cable regulator assembly 16 to the latch carrier assembly 12 via the attachment element, the inner door sheet metal panel will be sandwiched therebetween, with the inner door sheet metal panel having a hole aligned with the holes 86 and 88. The door latch assembly 22 may be secured, via assembly holes 90 to the door 10 (FIG. 1) and the latch carrier assembly 12 may be further secured to the interior of the door 10 (FIG. 1) via assembly holes such as holes 92, or other suitably positioned holes as is generally understood in the art.
FIG. 4 is an exterior perspective view of the combination of the cable regulator assembly 16 with the latch carrier assembly 12 and window carrier assembly 26 of FIG. 2, for example from a direction exterior to the automotive vehicle on which the hardware of this embodiment is installed, to illustrate features of said combination from an angle of view opposite that of FIGS. 1-3. The vehicle door hardware of FIG. 4 is shown in the final assembly orientation corresponding to that of FIG. 3, with lower edge 24 of the latch carrier assembly 12 slideably positioned between the aligned inner row of teeth 52 and the aligned outer row of teeth (not shown). Window carrier assembly 26 is secured to an upper end 16a of the cable regulator assembly 16 and includes integral seats 40 and 42 for receiving a glass panel (not shown) and upper and lower window carrier guides in the form of slots 121 and 120, respectively, of a size corresponding to the cross-section of the vertical guide 44 which is seated in the window carrier slots 120 and 121 to slide therealong. The window carrier slots 120 and 121 are molded into the window carrier assembly 26. The rotary actuator 80 of the DC motor or DC brushless motor type rotationally drives bobbin 60 on which is wound, in opposing directions, first and second lengths of coated cable (not shown), as described. A compliant bottom stop 130 in the form of a tapered arcuate cantilever beam integral with the cable regulator assembly 16 comprises a first end 132 molded into the cable regulator assembly 16 at a lower cable regulator assembly end 16b opposing the upper end 16a thereof, and is tapered into a terminal end 138 which opposes the first end 132 and about which is secured a rubber collar 142. The rubber collar 142 is positioned adjacent the vertical guide 44 so that when the window carrier assembly 26 is lowered to a predetermined bottom position at a substantially constant downward rate of movement, a stud 150 integral to the window carrier assembly 26 will contact the rubber collar 142 and will apply a deflection force to the bottom stop 130 deflecting the bottom stop in a downward direction toward a lower end 16b of the cable regulator assembly 16. The deflection force is resisted by an opposing upward spring force of the cantilever beam (or bottom stop 130). The effective length of the cantilever beam is reduced as the bottom stop is deflected sufficiently to contact a first substantially rigid support member 134, reducing the compliance of the bottom stop 130, and increasing the opposing upward spring force, so as to reduce the net downward deflection force and thus the rate of downward movement of the window carrier assembly 26 and window glass panel (not shown). The effective length of the cantilever beam is further reduced as the bottom stop 130 is further deflected due to the net downward deflection force sufficiently to contact a second substantially rigid support member 136, further reducing the compliance of the bottom stop 130, and further increasing the opposing upward spring force, so as to further reduce the net deflection force and thus the rate of downward movement of the window carrier assembly 26 and window glass panel (not shown). Finally, the bottom stop 130 is deflected in a downward direction under the net downward deflection force sufficiently for rubber collar 142 to contact a third substantially rigid support member 140 to substantially prevent further downward movement of the window carrier assembly 26. The graduation in opposing upward spring force offered through the bottom stop 130 and the series of support members 134, 136, and 140 provides for deceleration of the downward movement of the window carrier assembly 26 and window glass panel (not shown), avoiding abrupt load changes at a bottom stop position, and thereby reducing stress applied to such parts as the actuator 80 (FIG. 2), bobbin 60, the first and second lengths of coated cable (not shown) and the window carrier assembly 26, significantly increasing component durability in accord with an aspect of this invention. Such is provided substantially in a single piece cable regulator assembly 16 in accord with an important aspect of this invention. Mounting hole 86 passes through a beam 87 molded into the cable regulator assembly 16.
Referring to FIG. 5, an enlarged interior perspective view of the vehicle door hardware of FIG. 2 including the latch carrier assembly 12 with a partial cut-away view of the cable regulator assembly 16 to further detail features of the window carrier assembly 26. Window carrier assembly 26 includes integral seats 40 and 42 for receiving a glass panel (not shown) and upper and lower window carrier slots 121 and 120, respectively, of a size corresponding to the cross-section of the vertical guide 44 with the vertical guide seated within the slots 121 and 120 to slide therealong. The window carrier slots 120 and 121 may be molded into the window carrier assembly 26. The slotted guide 45 is molded into the window carrier assembly 26 and includes an outer arm 197 and a pair of inner arms 199 forming a slot between the inner and outer arms for slideably receiving the edge 17 of the cable regulator assembly 16. The edge 17 is maintained within the slot formed between the inner arms 199 and the outer arm 197 along the range of motion of the window carrier assembly 26 relative to the cable regulator assembly 16 and cooperates with the window carrier slots 120 and 121 and the vertical guide 44 to substantially restrict motion of the window carrier assembly 26 relative to the cable regulator assembly 16 to a single degree of freedom. A first section of coated cable 180 terminates, at a first end in a bulbous cable end fitting 182 retained in an upper seat 190. A second section of coated cable 184 terminates, at a first end in a bulbous cable end fitting 186 retained in a lower seat 192, which is secured, in a spring loaded manner, to be described, to the upper seat 190. The upper and lower seats 190 and 192 are provided to maintain the first and second cable sections 180 and 184 in tension throughout the range of travel of the window carrier assembly 26 relative to the cable regulator assembly 16, as will be further detailed.
Referring to FIG. 6, side cutaway view of a portion of the window carrier assembly 26 taken along reference 6--6 of FIG. 5 illustrates a compact cable tensioning feature. in which both the first and second cable sections 180 and 184 are maintained in tension throughout the range of motion of the window carrier assembly 26. More specifically, the window carrier assembly 26 includes a hollow member 210 with a central passage 224, defined between an upper edge 195 and a lower edge 189 in the hollow member 210, into the interior of the hollow member 210. Upper and lower "L" shaped members, 220 and 222, respectively, are positioned within the interior of the hollow member 210 with a horizontal hollowed-out section of the respective members 220 and 222 extending through the central passage 224, the hollowed-out sections of the members 220 and 222 forming respective upper and lower seats 190 and 192 for receiving respective end fittings 182 and 186 of the first and second sections of cable 180 and 184. Each of the upper and lower seats 190 and 192 include a passage 191 and 193 respectively, through which passages the respective sections of cable 180 and 184 are drawn. The upper and lower "L" shaped members 220 and 222, respectively, include respective bores 228 and 230 through a portion of the vertical section thereof, with respective coil springs 216 and 218 received in the bores 228 and 230. The springs 216 and 218 extend out of the bores and seat in respective upper and lower spring seats, 212 and 214. Upper spring seat 212 extends in a downward direction from a ceiling 210a of the hollow member 210 and the lower spring seat 214 extends in an upward direction from a floor 210b of the hollow member 210. The upper and lower "L" shaped members 220 and 222 are not directly coupled, but rather are driven together by the spring force of each of the springs 216 and 218 acting against respective ceiling 210a and floor 210b of the hollow member 210. An upward force is applied by the first section of cable 180 to the upper "L" shaped member 220 which is opposed by the spring force of coil spring 216 acting against the ceiling 210a. A downward force is applied by the second section of cable 184 to the lower "L" shaped member 222 which is opposed by the spring force of the coil spring 218 acting against the floor 210b. This cable tensioning arrangement allows for a significant amount of cable tensioning in a relatively small package. For example, the arrangement of FIG. 6 corresponds to a set up position with a length "Y" of take-up of the first section of cable 180 until the upper seat 190 contacts the upper edge 195, preventing further compression of the spring 216, and a length "X" of take-up of the second section of cable 184 until the lower seat 192 contacts the edge 189, preventing further compression of the spring 218. In a fully raised or fully lowered window position, the length of cable section take-up with be the sum of "Y+X" providing for a substantial amount of cable tensioning in a relatively small package.
The preferred embodiment is not intended to limit or restrict the invention since many modifications may be made through the exercise of ordinary skill in the art without departing from the scope of the invention. | An apparatus for installing a window, a window drive mechanism, and a latch carrier mechanism within a vehicle door includes a one-piece cable regulator having a molded passage thereabout for guiding at least one length of cable between the window and the window drive mechanism, a molded vertical passage for guiding motion of the window, a molded cantilever beam for contacting and gradually reducing the downward motion of the window near a window stop position and a molded guide for slideable cooperation with the door latch carrier, whereby the door latch carrier, once slideably secured within the guide, may be shifted over the cable regulator to a compact shipping and installation position, and then may be shifted outward from the cable regulator to a final assembly position within the door. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to the filing dates of U.S. Provisional Patent Application No. 62/076,982, entitled “Low Voltage DC Distribution System for Charging Passenger Devices” and filed Nov. 7, 2014, and U.S. Provisional Patent Application No. 62/076,879, entitled “Current Limiting Connector Assembly for Power Distribution” and filed Nov. 7, 2014. The disclosures of U.S. 62/076,982 and 62/076,879 are hereby incorporated by reference herein in their entirety.
FIELD OF THE DISCLOSURE
[0002] The subject matter of the present disclosure generally relates to power distribution systems, and more particularly relates to low voltage distribution of direct current power.
BACKGROUND OF THE DISCLOSURE
[0003] Previous systems for the distribution of power in a limited distribution area with a source of limited power, such as in the case of an aircraft, generally include a master control unit to monitor and distribute alternating current (AC) power to seat mounted electronics boxes (SEBs), outlet units and associated cables. The components or line replaceable units (LRUs), mounting brackets, protective shrouds, extended cable runs etc. all contribute to the weight of conventional systems. U.S. Pat. No. 5,754,445, entitled “Load distribution and management system” and filed Dec. 20, 1995 discloses an exemplary distribution system. The disclosure of U.S. Pat. No. 5,754,445 is hereby incorporated by reference herein in its entirety.
[0004] Often, in passenger aircraft the master control unit (MCU) is mounted in an overhead area outside of the passenger space. The MCU distributes three-phase, high voltage power through a number of outputs to groups of SEBs located at the passenger seats. This power is then converted at each seat group to a form usable by the outlet unit (OU) assembly. This conversion is typically performed by a SEB. In the case of an AC system the power provided by the OU is typically 110 volts alternating current (VAC), 60 Hz. In the case of a DC or universal serial bus (USB) output, 28 volts direct current (VDC) is used to power USB outlets, which additionally convert the power locally to 5 VDC for powering USB devices.
[0005] In order to save cost and weight, it is desirable that the connected wires be as small as possible. However, if a connected wire were to become overloaded or experience a short circuit, it may be possible for the power source to provide enough current to overheat smaller connected wires. For this reason, wires in these “seat-to-seat” cables are sized to safely carry the maximum current available.
[0006] Seat mounted hardware, such as a SEB, requires a mounting bracket which often has a mass requirement designed to ensure the bracket holds the unit in place during a crash and also to protect from vibration and thermally transfer heat away from the SEB to maintain acceptable operating temperatures. In addition to the bracket and its mounting hardware, a shield in the form a metallic or plastic shroud covers the SEB to prevent inadvertent contact with the housing of the hardware. The bracket and shroud are often located on the seat leg or underneath the seat. In either case, the volume of these parts, along with the volume of the SEB, encroach on the passenger space.
[0007] In existing power delivery systems on aircraft, cable assemblies carry the power in a daisy chain fashion from one seat group to the next seat group. These cables typically connect to each other within the seat structures. The materials used in electrical wiring are limited in the maximum temperature they can tolerate without degradation. The operating temperature of a wire can be greatly affected by the size of the wire and the amount of current flowing in the wire can generate significant heat. For these reasons, the current in an electrical wire must be controlled to prevent degradation due to excessive heating. At the same amount of current, in comparison to a larger wire, a smaller wire has higher electrical resistance which generates more heat when the current flows through it. The cables connecting the seat groups are generally heavy gauge power wires with proper insulating properties to safely carry the maximum current available. Connector assemblies are often located low on the seat leg with a separate extension cable to where the SEB is located in the seat. Additional cables then route from the SEB to the outlet assembly(s).
[0008] All of the mentioned features add weight to the overall system in order to process original aircraft power to power that is suitable for use with passenger devices.
[0009] The subject matter of the present disclosure is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.
BRIEF DESCRIPTION
[0010] Disclosed is a system for delivery of power to various electrical components, such as outlets, in passenger vehicles. In an embodiment, a number of cable assemblies are connected in a “daisy chain” fashion, each cable assembly providing power to a number of outlets associated with various passenger seats. The cable assemblies can be optionally run in a raceway located underneath the floor of the passenger cabin of a vehicle. At least one of the connectors of the cable assembly includes current limiting circuitry, which produces low voltage power for distribution to the outlets. Wiring from the connectors thus may be of smaller gauge than would otherwise be employed to pass high voltage power, and individual SEBs are not required. Optionally, seat group hubs can be used to distribute power from the connectors to a plurality of outlets.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The foregoing summary, preferred embodiments, and other aspects of the present disclosure will be best understood with reference to a detailed description of specific embodiments, which follows, when read in conjunction with the accompanying drawings, in which:
[0012] FIGS. 1A-B are depictions of a power delivery system according to the prior art.
[0013] FIGS. 2A-C are schematic depictions of a cable assembly according to an embodiment.
[0014] FIG. 3 is a schematic depiction of a cable assembly for delivery of power to USB-type outlets.
[0015] FIGS. 4A-C are schematic depictions of various current limiting devices that can be embedded in the cable assembly.
[0016] Like reference numbers and designations in the various drawings indicate like elements.
DESCRIPTION
[0017] FIGS. 1A and 1B illustrate the manner in which power was typically provided to outlets in previous designs. Power system 100 includes a master control unit 101 which provides power along large gauge supply wiring 102 to SEBs 103 . SEBs 103 , which are located at the passenger seating, provide power to outlets 104 and thereby to devices 105 . SEBs 103 are connected to one another by wiring 102 , which must exit the floor raceway at each seat group 106 to connect to SEBs 103 . FIG. 1B is a side view depiction of the architecture of FIG. 1A .
[0018] Embodiments of the disclosed system are much lighter than previous designs by providing power conversion at a central location, which obviates the need for a SEB, support brackets, leg disconnects, shrouds, etc., and minimizes the need for multi-conductor, heavily insulated seat-to-seat cables. Current state of the art systems are in the range of 120-150 lbs for a complete system of SEBs, brackets, shrouds, cables etc. Certain embodiments decrease the weight to 50-70 lbs. for an entire shipset. This saves an airline 60 percent of the total weight. The system consists of a single or multiple power source, current limiting cable assemblies and outlet units. Advantages of the disclosed subject matter include significant reduction in system weight, cost and complexity.
[0019] The power source may be a plurality of power supplies providing an appropriate voltage for distribution and direct use by the outlet units without the need for conversion at the seat. Voltage could also be provided directly from an aircraft power source if it is appropriate for the outlet units being powered. With source currents greater than those that can be carried through the input connector of an outlet unit, a current limiting device is required somewhere between the source and the outlet unit. A convenient location for this current limit is within the distribution circuit between the high current wiring and the wiring to the outlet. This transition happens at the interconnect cable as it leaves the trunk to a branch feeding the seat.
[0020] For the purposes of the present disclosure, high voltage generally refers to greater than or equal to 42VDC and low voltage refers to less than or equal to 28VDC. Further, large gauge wire refers to wire of gauge 12 (0.0808 inches in diameter) or larger and small gauge wire refers to wire of gauge 20 (0.0320 inches in diameter) and below.
[0021] In a first embodiment, a series of cable assemblies carry power from the power source to seat groups along a seat track in a daisy chain fashion. At each end of the cable assembly are connectors for providing the electrical contacts for daisy chaining These connectors include a current limiting device to provide power to the various seats. A current limiting circuit in the connector allows for a transition from high current large gauge wire to low current small gauge wire for delivery between the connector, a seat group hub, and the seats serviced by the seat group hub. Each connector consists of higher current conductors for interfacing between cable assemblies, and a lower current output connection for connection with a seat group.
[0022] FIG. 2A depicts embodiment cable assembly 200 . Input connector 201 has input interface 202 and output connector 203 has output interface 204 . Input connector 201 is connected to output connector 203 via connecting cable 205 . First seat group hub 206 is connected to input connector 201 and second seat group hub 207 is connected to output connector 203 . FIG. 2B is a top view illustration of cable assembly 200 as employed in a passenger cabin. Seat group hubs 206 and 207 provide power to outlets 208 . Cable assemblies can be “daisy chained” to provide power to large amounts of seating by connecting the input connector of one cable assembly to the output connector of the previous cable assembly. As both input connector 201 and output connector 203 provide power to a seat group hub, connector assembly 200 is sufficient to provide power to two rows of seats, decreasing the overall number of assemblies required to provide a vehicle with sufficient power for consumer electronics. Reducing the number of connections reduces the cost of the system, increases reliability and decreases weight. FIG. 2C illustrates a side view of a portion of the seating shown in FIG. 2B .
[0023] In addition to the current limiting device in a connector, a power line communication circuit could be used to transmit data on the status of each connector, for example information concerning current limits, power being utilized, built-in test status etc.
[0024] FIG. 3 is a schematic illustration of a particular embodiment for use with passenger seating having USB-type outlets. Cable assembly 300 includes input connector 301 and output connector 302 , which respectively have input interface 303 and output interface 304 , and are connected by connector cable 305 . Input connector 301 and output connector 302 are respectively connected to seat group hub 306 and 307 via low-voltage supply wiring 308 and 309 . Seat group hubs 306 and 307 each supply power to outlets 309 via outlet wiring 310 . As input connector 301 and output connector 302 each contain current limiting circuitry that conditions power to a form suitable for use with outlets 309 , small gauge wiring can be used for low-voltage supply wiring 308 and outlet wiring 310 than would be possible if conversion of power was taking place in individual seat electronic boxes. Connections between the various components, for instance between the outlets and the seat group hubs, and between the seat group hubs and the input and output connectors can be modular, or readily detachable. This facilitates quick interchange of defective or outdated components and reduced maintenance.
[0025] The current limiting function may be implemented by any suitable means such as a fuse, resistor, circuit breaker, or other similar device. Further, there may be one or more current limiting means for each load wire having the same or different current limits depending on the capacity of the connected wires. FIGS. 4A, 4B and 4C are exemplary circuits for implementations using a simple fuse ( FIG. 4A ), a positive temperature coefficient resistor ( FIG. 4B ) and a more complex active current limit circuit ( FIG. 4C ). The choice of a particular current limiting circuit may be made according to the accuracy of current-limit required, cost of implementation and other factors such as weight, tolerance to temperature extremes, physical space, power dissipation etc. Generally, preference is given to the lowest cost and smallest footprint current limit that will meet the system requirements. The components depicted by FIGS. 4 A-C can be held within a input connector (such as 301 ) and can be hermetically sealed to ensure operation in harsh environments. Current carried through the trunk connection along the seat track would typically be in the range of 25 Amps, requiring a large gauge wire to carry the current without significant voltage loss. Branches from the trunk up to the seat group would only require a smaller current such as 1.5 Amps and therefore a much lighter gauge of wire. This is addressed by the current limiting circuit within the connector assembly.
[0026] Referring to FIG. 4C , integrated circuit 401 monitors the output current and limits current when a threshold is exceeded. An under voltage shutdown is performed if the source is below a predetermined threshold. An automatic restart can be optionally performed after any fault condition has triggered a limiting event. Integrated circuit 401 may be any appropriate active current limit controller, such as a LT4363 unit manufactured by Linear Technologies Corporation, Milpitas, Calif. In part, integrated circuit 401 protects loads from high voltage transients. It regulates the output during an overvoltage event, such as load dump in vehicles, by controlling the gate of external, N-channel metal oxide semiconductor field effect transistor (MOSFET) 402 . The output is limited to a safe value, allowing the loads to continue functioning. Integrated circuit 401 also monitors the voltage drop between the current sense input (SNS) and OUT pins to protect against overcurrent faults. An internal amplifier limits the voltage across current sense resistor 403 to 50 mV. In either fault condition, a timer is started that is inversely proportional to the MOSFET stress. Before the timer expires, the open collector fault output (FLT) pin pulls a low voltage to warn of impending power downage. If the condition persists, the MOSFET is turned off. Depending on the embodiment, the integrated circuit may remain off until it is reset or may restart automatically after a cool down period.
[0027] Two precision comparators can monitor the input supply for overvoltage (OV) and undervoltage (UV) conditions. When the potential is below a UV threshold, the external MOSFET is kept off. If the input supply voltage is above an OV threshold, the MOSFET is not permitted to turn back on. In the implementation of FIG. 4C , only the UV circuit has been employed. Resistor 404 , resistor 405 and capacitor 406 form a voltage divider to the UV monitor circuit input of integrated circuit 401 .
[0028] The voltage regulator feedback input (FB) input pin of integrated circuit 401 is used to monitor the output voltage of the circuit through the voltage divider formed by resistor 407 and resistor 408 . The exact implementation of the active current limit circuit may vary depending on the needs of the downstream outlets or loads.
[0029] The disclosed subject matter may present several advantages. Particularly, because power conversion is not necessary at each individual seat, SEBs, along with their brackets and shrouds, are eliminated, presenting considerable weight savings. Further, the number of conductors in the seat-to-seat cabling is reduced. No ground fault interrupter (GFI) is required as the voltage levels at the passenger seat are considered low voltage.
[0030] The use of lower power voltage in the power arriving from the input and output connectors means that no GFI or arc fault detection is required, as voltages are maintained at levels below those considered hazardous.
[0031] In certain embodiments, the number of cable interface connectors required with respect to previously existing designs is reduced by up to 75 percent.
[0032] Certain embodiments may be made fluid-tight so as to reduce or eliminate the impact of errant liquids. The connectors may be configured so as to only be capable of being connected in a correct manner. Depending on the particular requirements at hand, self-resetting or non-self-resetting current limiters may be employed.
[0033] Although the disclosed subject matter has been described and illustrated with respect to embodiments thereof, it should be understood by those skilled in the art that features of the disclosed embodiments can be combined, rearranged, etc., to produce additional embodiments within the scope of the invention, and that various other changes, omissions, and additions may be made therein and thereto, without parting from the spirit and scope of the present invention. | A low voltage DC distribution system to provide power to power or charge passenger electronic devices. Cable assemblies pass high voltage power down in daisy chain fashion to various seat groups. Connector elements contain current limiting circuitry which provides low voltage power for distribution to seat electronic components via small gauge wire. Compared to previous systems, embodiments may have a marked reduction in installed weight, encroachment on passenger space, easier installation and reduced impact on seat structures. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to improved drive systems for vehicles and more particularly to an improved hydrostatic drive system for a combine particularly adapted for use in hilly terrain.
2. Prior Art
It is well known in the art of hydrostatic drive systems to include motors of variable displacement whose torque output can be controlled. Examples of such drives are shown in U.S. Pat. Nos. 3,734,225; 3,637,036; 3,595,334 and 3,587,765. Of these patents '225 and '334 use pressure responsive means for varying motor displacement and the torque output of the motor.
Auxiliary drive systems for combines are shown in U.S. Pat. Nos. 4,140,196 and 3,736,732, but using fixed displacement motors. Auxiliary drive systems having electrical controls are shown in U.S. Pat. Nos. 4,177,870; 4,027,738 and 3,894,606, but using fixed displacement motors.
Earlier attempts by the assignee herein to develop automatic shifting from two wheel drive to four wheel drive for combines brought several problems to light. Excessive pressure spikes were induced in the hydrostatic system when shifting from two to four wheel drive and back to two wheel drive. Such pressure spikes can damage system components such as hoses and seals. Perhaps the overriding problem with earlier systems was that the machine operator experienced excessive deceleration and acceleration in shifting from two to four wheel drive and four to two wheel drive, respectively.
In developing an effective drive system for combines, special factors are involved such as the increasing load on the combine as grain is collected in the grain tank during harvesting. Where the combine is destined for principal use in harvesting crops on hilly terrain (such as wheat in eastern Washington State), the function of a drive system takes on particularly important considerations of operator and vehicle safety. That is, the degree of slope traversed by so-called "hillside" combines can require maximum tractive effort not only to move the combine, but to assist in preventing downhill side slip of the machine. When such factors are involved, safety of operation is enhanced where the drive system can automatically respond to conditions or to the requirements of the operator.
SUMMARY
The invention provides an improved vehicle drive system having a variable displacement motor, the displacement of which is automatically controlled in response to actuation and deactuation of an auxiliary drive. The improved drive system further includes means for automatically deactuating the auxiliary drive when the vehicle assumes a forward climb angle less than a predetermined minimum, as when the vehicle approaches the crest of a hill, requiring less torque. The drive system of the invention provides a smoother transition in vehicle speed change as the auxiliary drive is engaged and disengaged.
The invention includes an electronic sensing and control system for effectively controlling the operation of the drive system while permitting operator override of automatic control inputs when desired or required.
The drive system of the invention reduces the pressure spikes induced within prior systems during shifting into and out of auxiliary drive. The result is less damage and wear on system components. The drive system minimizes acceleration and deceleration of the vehicle during shifting. Lastly, the system is particularly adapted to the requirements of hillside harvesting.
Briefly, the objects of the invention are to provide a vehicle drive system which minimizes vehicle speed change during shift into and out of auxiliary drive; which is automatically responsive to changing torque requirements; which is particularly well adapted for operation on hilly terrain; which permits the operator to assume control where it is desired or required that automatic inputs be overriden; which provides longer life for the components of the system by reducing pressure spikes; and which provides greater operator and vehicle safety.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a self-propelled combine utilizing the drive system of the invention;
FIG. 2 is a schematic drawing of the hydrostatic drive system and the control system of the invention;
FIG. 3 is a schematic of the electronic control system of the invention; and
FIG. 4 is a graph showing performance characteristics of the drive system of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a combine having forward main drive wheels 10 and rear steerable auxiliary drive wheels 12. The combine includes a crop harvesting header 14 for gathering the crop and consolidating it laterally for rearward feed by a feeder 16 into a threshing and separating unit (not shown). The combine also includes an engine 18, an operator's station 20, and a grain tank 22 for collection of harvested grain. An actual embodiment of the combine represented in FIG. 1 is a Model 1470 combine produced by the assignee herein.
Referring now also to FIG. 2, the basic propulsion drive system for the main drive wheels 10 consists of a variable displacement pump 24 and a variable displacement motor 26 interconnected in a closed loop by a forward line 28 and a reverse line 30. The pump 24 is driven through conventional means by the engine 18 of the combine. Output from the motor 26 is transferred mechanically to a variable ratio transmission and differential unit 29 to the main drive wheels 10. It will, of course, be understood that the drive system includes suitable pressure relief components shown, but not described.
A charge pump 27 is driven with the pump 24 to provide charge pressure fluid from a reservoir 31 to the forward line 28 and reverse line 30 by lines 32 and 34, respectively. Charge pressure is also selectively available through a manual control valve 36 to either side of a servo cylinder 38 for varying the displacement of the pump 24 and to change the direction of output to provide speed change and reverse drive for the combine.
Fluid pressure from the charge pump 27 is available through a line 40 to either side of a servo cylinder 42 for varying the displacement of the motor 26 as controlled by a dual pilot-operated valve 44. The displacement of the motor 26 is variable between 10° and 18° positions of the motor swash plate establishing minimum and maximum strokes of the motor.
The drive system of the invention includes means for driving the rear steerable wheels 12 of the combine. Referring still to FIG. 2, the wheels 12 are driven by respective hydrostatic motors 58 hydraulically connected in parallel by lines 60 and 62. The motors 58 are of fixed displacement reversible type, drivingly connected to the respective wheels 12 by planetary gear final drive units having reduction gear ratios of 34.49 to 1. Lines 64 and 66 are connected respectively from main drive lines 28 and 30 and extend into connection with a pilot-operated control valve 68 of the two-position, four-way type. Lines 70 and 72 interconnect the control valve 68 with the motor lines 60 and 62, respectively. It will thus be seen that the auxiliary drive motors 58 are connected in parallel with the main drive motor 26, with the control valve 68 operable to actuate and deactuate power drive to the motors 58. A line 74 is connected between the charge line 40 and the control valve 68 to interconnect with the lines 70 and 72 when the control valve 68 is in the position shown in FIG. 2. This permits pressure fluid from the charge pump 27 to be available in the auxiliary drive motor circuit to prevent cavitation when the auxiliary drive is disengaged.
The position of the auxiliary drive control valve 68 is controlled by a two-position solenoid valve 76 to which pressure fluid is available through a line 78 from line 74. A pilot line 80 is connected between the solenoid valve 76 and the control valve 68. The solenoid valve 76 is shifted to direct pressure fluid into the pilot line 80 in response to receiving an electrical signal from an electronic control system to be described. A variable restrictor 82 is connected in the line 78, and another variable restrictor 83 between the valve 76 and the reservoir, provide a controlled spool movement of the control valve 68 to prevent shifting of the valve 68 too abruptly.
The displacement of the main drive motor 26 is variable between its 10° and 18° swash plate positions (that is, minimum and full stroke) through two operational inputs. One input is through the actuation of the pilot-operated valve 44 in response to a predetermined fluid pressure received from the main drive system through a pilot line 84 connected to the forward drive line 28. The second input involves actuating the pilot-operated valve 44 in response to a pilot pressure controlled by actuation of a two-position solenoid valve 86. The valve 86 is actuated by a signal from the electronic control system, which, as will be described, is generated in response to actuation of a pressure switch S4 connected by a pilot line 90 to the forward drive line 28 of the main drive system.
The valve 86 is connected on one side to a line 91 which leads to the reservoir 31'. The other side of the valve 86 is connected to the output of the charge pump 27 via a line 92 connected between the line 40 and the valve 86. A restrictor 94 is connected in the line 92. A pilot line 96 extends between the line 92 and the valve 44. The valve 86 is actuated by a signal from the electronic control system shifting the valve to allow fluid flow through line 92 and into line 91. The flow across the restrictor 94 causes a pressure drop in pilot line 96. This permits the spring of the valve 44 to shift the valve 44 to direct fluid into the servo cylinder 42 to shift the swash plate of the motor 26 to minimum displacement (10° position).
It will be seen that the hydrostatic drive system includes suitable pressure relief and pilot-operated valves illustrated in FIG. 2, but not described herein because such valves are conventional in closed loop systems. A so-called "foot-n-inch" valve 97 is provided to release the closed loop pressure to stop the combine in response to depressing a pedal in the combine cab.
The drive system of the invention is controlled by a unique electronic control system shown in general at 98 in FIG. 2 and in detail in FIG. 3.
The logic control circuitry generally labeled as 98 in FIGS. 2 and 3 is the decision making portion of the four wheel drive shaft control of the invention. The logic control circuitry 98 consists of the following principal subcircuits or portions which will be described in detail hereinbelow; a voltage regulator circuit 102, a PSI (pressure delay two-to-four wheel shift circuit 106, an audible alert circuit 108, a delay four-to-two wheel shift circuit 110, and output drive circuits generally labeled 114 and 116.
The operational interface between the control circuitry 98 and the combine drive system is to actuate a solenoid 118 (of the valve 76) to shift between 2-wheel and 4-wheel drive and to actuate a solenoid 120 (of the valve 86) to change the displacement of the variable motor 26. The manner and circumstances under which these solenoids are actuated will become clear as the description proceeds.
Refering first to the voltage regulator circuit 102, power to the voltage regulator circuit 102 is provided from the combine power source indicated in FIG. 3 as +12 volts DC. As a safety feature, the supply voltage is coupled in series through a mechanical switch (not shown) such that when the combine is in third or road driving gear, shifting from two-to-four wheel drive is prevented. The voltage regulator circuit 102 is of conventional design, including inductors and capacitors to filter the supply input voltage to a voltage regulator integrated circuit (IC) 122 of conventional design. Additional conventional capacitors filter the output of the IC regulator 122 to provide a stable output voltage to prevent any fluctuations in the combine's +12 VDC source from affecting the desired circuit delay times.
A brief description of the various operator-controlled and condition-responsive switches of the control circuitry will preface a more detailed description of the circuitry and its control functions.
A switch S1 in the combine cab enables the operator to select manual or automatic modes of shifting between 2-wheel and 4-wheel drive. A foot switch S2 in the combine cab enables the operator to engage 4-wheel drive at any time, other than when the transmission 29 is in 3rd gear (highest range).
A so-called tilt switch S3 is mounted on the body of the combine and comprises a conventional grade-sensing mercury switch operable to close when the forward climb angle of the combine is about 5° (9%) or greater and to open when the forward climb angle decreases to 2.5° (4%). Accordingly, the switch S3 controls automatic shifting into 4-wheel drive as the combine climbs a hill and controls shifting back into 2-wheel drive as the combine approaches the crest of a hill wherein less drive torque is required.
Switch S4 is operable in response to a predetermined pressure (4,000 psi) in the forward drive line 28 of the hydrostatic drive system to cause shifting into 4-wheel drive when the tilt switch S3 is closed (combine forward climb angle 5° or more).
A switch S5 is mechanically actuated in response to movement of the spool of the control valve 68 to provide a positive signal to the control circuitry of the position of the valve 68.
A switch S6 is operable when the combine transmission 29 is in reverse drive to prevent a change in motor displacement to 10° to maintain maximum torque on the front drive wheels. Reverse drive up a hill is best accomplished when maximum torque is available at the front drive wheels on which most of the machine weight is applied. Without the switch S6, as will become apparent, the automatic shift system could increase the torque of the rear wheels which could spin out and not assist in reverse drive up a hill.
Operation of the manual control of the four wheel drive operation will be explained first. In this mode, foot switch S2 is selectively closed and opened by the operator. When closed, the foot switch S2 couples the voltage from the 12VCD supply and lead 124 to a Nor gate 128. A high or source level supply signal to Nor gate 128 indicates a demand for a four wheel drive mode and this produces a negative voltage at the output pin of the Nor gate 128 which is coupled to the input pin of an inverter 132. Digital designation of a (+) for a high level voltage and (-) for a low or negative will also be used in the following circuit description.
A low (-) signal to the input of inverter 132 permits the output of inverter 132 to go high (+) to energize the valve solenoid 118 through the output drive circuit 114, as will be explained.
When the output of inverter 132 goes high (+), an NPN transistor 154 of drive circuit 114 is biased to conduct. When transistor 154 conducts, the collector of 154 is pulled low. A resistor divider network 156 and 158 then causes a PNP transistor 160 to conduct thus energizing the valve solenoid 118 through conductor 162.
The output drive circuit is protected from overcurrent damaging the control in the event of a short circuit in the conductor 162 or valve solenoid 118, as will be explained. The current required to energize solenoid 118 is supplied through resistor 164. When this current exceeds a given value, the voltage drop across resistor 164 will cause a PNP transistor 166 to conduct. This will in turn cause the NPN transistor 168 to conduct, pulling the collector of transistor 168 low. This stops conduction of transistor 154 by pulling the base of 154 low through diode 170. Transistor 168 also forces conduction of transistor 166 through resistor 172, thus forcing transistor 154 to remain off. This will stop the conduction of transistor 160 and de-energize the valve solenoid 118. The output transistor will remain off (non-conducting) until the 12VDC supply is removed (for instance, by turning the combine key switch off). Reapplying the 12VDC supply power will reinitiate the circuit.
Refer now to the motor engagement drive circuit 116. Upon activation of the valve solenoid 118, which moves the valve spool of the valve 68 (FIG. 2), the limit switch S5 is activated. This valve spool switch closure places a low (-) on input 176 of an NOR gate 178 through diode 180. As long as a low (-) is on input 182 of the NOR gate 178, the output of NOR gate 178 will go high (+) and activate the motor solenoid 120 through output drive circuit 116. The output drive circuit 116 is substantially identical to the output drive circuit 114, with the inclusion of a lamp indicator L. The operation of the circuit will therefore not be repeated.
The reverse indication switch S6 is incorporated to allow maximum torque in the reverse direction although the speed in the reverse direction is reduced. With the combine traveling in a forward direction the reverse indication switch S6 will be open allowing RC networks 186 and 188 to charge the capacitors thereof producing a high (+) at the input of inverter 190. This will produce a low (-) at the output of inverter 190 and at the input 182 of NOR gate 178, upon placing the combine in reverse (by actuating the control 36) the reverse indication switch S6 will close discharging the capacitors associated with RC networks 186 and 188. This will produce a low on the input of inverter 190 causing a high on the output of inverter 190 and on the input 182 of NOR gate 178. This will prevent a change in motor displacement to minimum displacement (10°) while traveling in reverse. RC networks 186 and 188 are used for input filtering as is RC network 192.
RC network 194 is used to delay the change in motor displacement upon shifting from four to two wheel drive. When four wheel drive is no longer required in either manual or automatic operation, the valve solenoid 118 is de-energized. This in turn opens the valve spool switch S5. This causes diode 180 to be reverse biased allowing the capacitor in the RC network 194 to charge placing a high (+) on the input 176 of NOR gate 178 after three tenths of a second. A high on input 176 of NOR gate 178 causes the output of NOR gate 178 to go low (-). This de-energizes the motor displacement solenoid 120 through the output drive circuitry 116. It will be seen that the combine will be retained in four-wheel drive until the foot switch S2 is released by the operator.
The foregoing completes the description of the manual controlled operation mode of the control system 98 of FIG. 3. As might be expected, the automatic operation mode of the logic control system 98 utilizes a majority of the same circuitry as the manual controlled mode operation.
Refer now to the automatic operation of the four wheel drive logic circuit 98. As mentioned, switch S1 is movable to select the two wheel or four wheel drive mode. In the two wheel position of switch S1, the machine will remain in the two wheel drive mode unless the operator operates the foot switch S2 which will then initiate the operation described above.
In the four wheel position of switch S2, the control logic circuit 98 will automatically determine the type of drive desired. Switch S2 is electrically coupled in series with tilt switch S3 and the 4000 psi pressure switch S4. Tilt switch S3, as the name implies, is actuated by the position or attitude of the machine relative to horizontal in the direction of travel of the combine. For example, when the machine is moving up an incline of five degrees (5°) or more, the tilt switch S3 will be closed. When the machine is moving up an incline or over ground conditions which produce an increased propulsion load, the pressure in line 28 (FIG. 2) will increase because of the increased load on the combine drive system which will close the pressure switch S4. When both the tilt switch S3 and the pressure switch S4 are closed, the control circuit 98 will initiate a timing sequence to place the machine in the four wheel drive mode by energizing the valve solenoid 118 and the motor solenoid 120.
Assume then, that switch S1 is in the four wheel drive position, the machine is moving up an incline and hence, switches S3 and S4 are closed to cause the machine to automatically shift from a two wheel drive mode to the four wheel drive mode. In this state, a high level voltage will be coupled through switches S4, S3 and S2 to inverter 144 to initiate the four wheel drive mode of operation. A high (+) level input to inverter 144 produces a low voltage level at the output of the inverter 144 which is coupled to input 146 of an NOR gate 148. Input 150 of NOR gate 148 is controlled by a flip flop made up of NOR gates 202 and 204. This flip flop determines the energized or deenergized state of the valve solenoid 118 as determined by the automatic mode of operation. Input 150 of NOR gate 148 will remain low (-) at any time the automatic mode of operation is not energizing the valve solenoid 118, as determined by a low (-) at the output of NOR gate 204. With the input 150 of the NOR gate 148 low (- ), a low (-) on input 146 of NOR gate 148 will produce a high (+) on the output of NOR gate 148. This high (+) at the output of NOR gate 148 produces a high (+) at the non-inverting input 152 of a monostable multi-vibrator 130. The inverting input 206 of the multivibrator 130 is controlled by an oscillator circuit 288. The oscillator circuit 288 continuously reinitializes the timing circuit 106 as long as input 152 of the monostable multi-vibrator 130 is held low (-). Once input 152 of the monostable vibrator 130 goes high (+) the input 206 from the oscillator circuit 288 is ignored.
The high (+) on input 152 of monostable multivibrator 130 starts the time delay associated with circuit 106. The time delay is determined by resistor 138 and capacitor 142. When input 152 is continuously held high (+) for one and one half seconds, output 136 of monostable multi-vibrator 130 will go high (+). A high (+) at the output 136 of monostable multi-vibrator 130 will produce a high (+) at input 208 of NOR gate 202. This high (+) at input 208 will cause the output of NOR gate 202 to go low (-). The low (-) at the output of NOR gate 202 will force a low on input 212 of NOR gate 204. As long as input 214 of NOR gate 204 is low, a low on input 212 of NOR gate 204 will cause the output of 204 to go high energizing the valve solenoid 118 and motor solenoid 120 through the output driver circuitry 114 and 116 respectively, as previously described. At the same time, the high (+) on the output of NOR gate 204 will place a low on the output of NOR gate 128 which in turn will activate a driver circuit 216 which will electrically bypass the pressure switch S4. This will prevent system pressure fluctuations from influencing the effect of the control logic, and hence, tends to maintain a smooth driving action. Once the logic circuitry 98 has activated four wheel drive, the requirement of maintaining a minimum pressure of 4000 psi on line 28 (FIG. 2) therefore no longer exists. Pressure switch S4 is electrically bypassed by placing a high (+) on the conductor 218 between the pressure switch S4 and tilt switch S3.
As the output of NOR gate 128 goes low (-), PNP transistor 220 in the driver circuit 216 is forced to conduct. This causes the collector of transistor 220 to conduct current. The driver circuit 216 has current limiting protection to prevent damage to the transistor 220 in the event excessive current is required due to a short circuit condition. The current required to maintain a high (+) state on the collector of transistor 220 is supplied through a resistor 222. When the voltage drop across resistor 222 reaches an adequate level, transistor 224 will conduct thus limiting the current through transistor 220.
When the output of NOR gate 204 goes high (+), initiating four wheel drive, the input 210 of NOR gate 202 will go high (+). This will prevent a change of state at input 208 of NOR gate 202 from having any further effect on the operation of the output driver circuitry 114.
Once in four wheel drive, the logic control circuitry will maintain four wheel drive until the tilt switch S3 or the auto/manual operator selectable switch S1 is open continuously for two seconds.
With the output of NOR gate 202 forced low (-) at the same time the valve solenoid 118 is energized, as previously described, input 226 of NOR gate 230 will be forced low (-). This will allow a low (-) on input 228 of NOR gate 230 to initiate the time delay circuit 110 by causing the output of NOR gate 230 and likewise input 232 of monostable multi-vibrator 234 to go high (+). Input 228 of NOR gate 230 will go low (-) at any time switch S1 or switch S3 is opened. The operation of the time delay circuit 110 is identical to the operation of the time delay circuit 106 previously described. The two second time delay is determined by resistor 235 and capacitor 286.
A continuous two second period of the tilt switch S3 or auto/manual operator selectable switch S1 being open will produce a high (+) on output 236 of monostable multivibrator 234. This high (+) on the circuit 236 of monostable multivibrator 234 will force a high (+) on input 214 of NOR gate 204. A high (+) on input 214 of NOR gate 204 produces a low (-) on the output of NOR gate 204 and likewise on the input 210 of NOR gate 202. At this time input 208 of NOR gate 202 will be low (-) since, as previously described switches S1, S3 and S4 must all be closed for a period of one and one half seconds before input 208 of NOR gate 202 will go high (+).
With inputs 208 and 210 of NOR gate 202 low (-), the output of NOR gate 202 will go high (+). This high (+) at the output of NOR gate 202 will produce a high (+) at input 212 of NOR gate 204 maintaining a low (-) at the output of NOR gate 204. This low (-) at the output of NOR gate 204 will de-energize the valve solenoid 118 as previously described and cause a shift from four wheel drive to two wheel drive.
An audible alert 250 is incorporated in the system to give the operator an advanced warning as to when the machine is going to shift from four wheel drive to two wheel drive. This is to allow him to adjust his forward speed to compensate for the slight increase in speed caused by the automatic shift.
When the output of NOR gate 230 goes high (+) a two second time delay is initiated for shifting from four wheel drive to two wheel drive as previously described. At the same time a one half second time delay is initiated which delays the audible alert 250 from sounding. The difference in these delays (one and one half seconds) is the time the audible alert is activated, as will be described.
When the output of NOR gate 230 goes high (+), the input to inverter 238 is pulled high (+). A high (+) on the input of inverter 238 will produce a low (-) on the output of inverter 238. Resistor 240 and capacitor 242 will cause a one half second delay before the input 244 of NOR gate 126 is at a low (-) state. As long as input 140 of NOR gate 126 is low (-) the output of NOR gate 126 will go high (+) when input 244 of NOR gate 126 goes low (-). This high (+) on the output of NOR gate 126 will activate the audible alert 250 through the driver circuit 108, as will be explained.
Input 140 of NOR gate will be low (-) when the foot switch S2 is not activated, thus allowing the audible alert to sound when shifting from four wheel drive to two wheel drive as explained previously. Upon closure of foot switch S2 to actuate four wheel drive, input 140 of NOR gate 126 will go high (+) forcing the output of NOR gate 126 low (-). A low on the output of NOR gate 126 will disable the audible alert. This feature is to eliminate the audible alert 250 from sounding in the event the operator overrides the automatic control.
A high (+) on the output of NOR gate 126 will cause the NPN transistor 246 to conduct. When transistor 246 conducts the collector of transistor 246 is pulled low (-). This will cause the PNP transistor 248 to allow current flow to the audible alert 250.
The driver circuit 108 has current limiting protection to prevent damage to the PNP transistor 248 in the event excessive current is required due to a short circuit condition at the audible alert 250. The current to the audible alert 250 is supplied through a resistor 252. When the voltage drop across resistor 252 reaches an adequate level, a transistor 254 will conduct thus limiting the current through transistor 248.
A low (-) at the output of NOR gate 126 will prevent conduction of NPN transistor 246, and in turn stop conduction of PNP transistor 248. With transistor 248 not conducting, current will not flow to audible alert 250.
The audible alert 250 is automatically deactivated when shifting from four wheel drive to two wheel drive has occurred. The output of NOR gate 202 is forced high (+) when the valve solenoid 118 is deenergized as previously explained. This high (+) at the output of NOR gate 202 will place a high (+) on the input 226 of NOR gate 230, thus forcing a low (-) on the output of NOR gate 230. This low (-) on the output of NOR gate 230 will produce a high on the output of inverter 238 and likewise the input 244 of NOR gate 126 turning off the audible alert.
A summary of the operation of the drive system of the invention can perhaps best be seen with reference to FIG. 4.
The bottom of FIG. 4 shows a slope profile of a hill traversed by a combine. The automatic sequence of events in the operation of the transmission and the controls are shown thereabove, as the combine moves up the hill. The changes in vehicle ground speed, hydrostatic pressure, and variable motor swash plate angle are depicted for each event displayed along the horizontal axis and are believed to be readily understood.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. | A self propelled combine having forward main drive wheels and rear steerable wheels. A hydrostatic drive including a variable displacement motor is arranged to drive the main drive wheels. An electronic-hydraulic control system is automatically operable to drive the rear steerable wheels in response to sensing preselected pressure and combine attitude values while automatically varying the displacement of the hydrostatic drive motor to minimize combine speed changes and to provide torque as required under varying loads imposed by hilly terrain or increasing amounts of grain collected in the grain tank of the combine. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to means and methods for chemical flood testing and, more particularly, to chemical flood testing using microwave energy.
2. Description of the Prior Art
Chemical flood core testing in a linear or single direction is disclosed and described in U.S. patent application Ser. No. 336,142 now U.S. Pat. No. 4,490,676 12/25/84 and application Ser. No. 336,136, now U.S. Pat. No. 4,482,634 11/13/84 both filed on Dec. 31, 1981 and assigned to Texaco Inc., assignee of the present invention. The practice heretofore has been to take the linear flow data from a long core flood test and through known mathematical techniques predict a two dimensional chemical flood in a pattern in an oil reservoir. The present invention is capable of actually measuring a two dimensional chemical flood through a porous medium that may be used to either supplement and prove the predictions based on the linear flow testing or it may be used independently of the predictions as another step in chemical flood testing.
SUMMARY OF THE INVENTION
The means and method of a two dimensional chemical flood testing includes evacuating a porous medium contained in a test cell. The evacuated porous medium is then irradiated with a beam of microwave energy in said test cell in a plurality of predetermined locations of said test cell defined by a two-axis coordinate system. The microwave energy that has passed through the porous medium at each location is detected. The porous medium is then filled with brine and the irradiating and detecting steps are repeated. The porous medium is then flooded with crude oil, or its substitute, and again the irradiating and detecting steps are repeated. The porous medium is flooded with brine and, again, the irradiating and detecting steps are repeated. A calibration curve for each location is derived from the detected microwave energy at the location from the prior detecting steps at the location. The porous medium while being flooded with a chemical flood system at a predetermined flow rate is periodically subjected to the irradiating and detecting steps so that the test cell is periodically scanned in two directions by microwave energy. A two dimensional pattern of the chemical flooding is derived for each scan in accordance with the detected microwave energy at each location for the scan and the calibration curves.
The foregoing and other objects and advantages of the invention will appear more fully hereinafter from consideration of the detailed description which follows, taken together with the accompanying drawings wherein one embodiment of the present invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for illustration purposes only and are not to be construed as defining the limits of the invention.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial representation in combination with a simplified block diagram of a microwave chemical flood scanner constructed in accordance with the present invention.
FIG. 2 is a detailed block diagram of the electrical portion of the microwave chemical flood scanner shown in FIG. 1.
FIGS. 3A and 3B are an end view and a side view, respectively, of the mechanical portion of the microwave chemical flood scanner shown in FIG. 1.
FIG. 4 is a top view of the test cell shown in FIGS. 1 and 2.
FIG. 5 is a simplified block diagram of the hydraulic system of the microwave chemical flood scanner shown in FIG. 1.
DESCRIPTION OF THE INVENTION
U.S. patent applications, Ser. Nos. 336,136 and 336,142, filed on Dec. 31, 1981 by the inventors of the present invention which is assigned to Texaco Inc., assignee of the present invention, relate to chemical flood evaluations being made on cores of an earthen reservoir to evaluate the chemicals used. It is possible with the information from those analyses to project and predict a flood pattern of a particular chemical flood system through a reservoir. A chemical flood system is a flood system using one or more liquid chemicals in conjunction with a drive liquid. The drive may be a liquid or it may be water or brine. Often, a five-spot operation is used in enhanced oil recovery; i.e., four wells defining substantially a horizontal square with a fifth well in the center of the square. Thus, with a given injection well, there is a three dimensional flow of chemicals and drive liquid through the reservoir vertical, traverse and longitudinal. Since the chemical flood analyses of the aforementioned U.S. applications deal with only one dimension or direction, the present invention using two-dimensional monitoring yields more information in regard to a two dimensional flow pattern that the liquids will follow.
With regard to FIG. 1, a rectangular porous medium in a test cell 3, and any liquid flowing through it, is subjected to a beam of microwave energy by a microwave transmitter 5, as hereinafter explained, which passes through the test cell 3 and is detected by detector assembly 8. Microwave energy is herein defined as being electromagnetic energy provided at a microwave frequency. Microwave transmitter 5 receives the necessary operating voltages from voltage sources 10 and 11. The output from detector assembly 8 is provided to a controller 14 which provides information to computer 15.
Liquid means 20 causes different liquids at different times to be injected into test cell 3, as hereinafter explained, at a predetermined velocity which will eventually flow through test cell 3 and enter receiving means 24. As the liquid passes through test cell 3, microwave transmitter 5 and detector assembly 8 are maintained in fixed relationship to each other but are moveable in an x direction and in a y direction under the control of controller 14, and the movement is repeated during the flowing of the liquids through test cell 3. All of the foregoing will be described hereinafter in greater detail.
With reference to FIG. 2, microwave transmitter 5 includes a Gunn source 28 receiving a DC voltage from DC source 10 and an AC voltage having a preferred frequency of 1 KHz from AC source 11 and provides microwave energy. Gunn source 28 may be of a type that is manufactured by Racon, Inc. as their part number 10014-102-02. The microwave energy is provided at a preferred frequency of 10.525 GHz whose amplitude oscillates at the 1 KHz frequency. Source 28 provides the microwave energy to an attenuator 30 which in turn provides the microwave energy to a horn antenna 33 which provides the beam of microwave energy. It should be noted that a horn antenna is used because Gunn source 28 is being operated in an X-band mode mainly in 8.2 to 12.4 GHz.
It may be desired to operate Gunn source 28 at a preferred frequency of 24.125 GHz which is in the K-band range of frequency namely 18.0 to 26.5 GHz. Operation in the K-band mode makes monitoring of the liquid passing through test cell 3 more independent of temperature and salinity. The determination of whether to use X-band or K-band is also in part determined by the thickness of the formation being tested. A preferred power output for the X-band is 10 milliwatts or for the K-band, 20 to 100 milliwatts, are safe operating levels. When operating in a K-band, horn antenna 33 is replaced by a dielectric rod antenna and Gunn source 28 is of a type similar to that manufactured by Plessey Optoelectronics and Microwaves, Ltd. as their part GDO131. Further, the AC source may be omitted in K-band operation and an isolator is substituted for attenuation pad 30.
The microwave energy passing through sample cell 3 is received by another horn antenna 36 of detector assembly 8, in X-band mode of operation, or a dielectric rod antenna in a K-band mode, and provided to a diode detector 38 which provides a signal corresponding to the detected microwave energy to a power meter 40. Power meter 40 provides an indication of the detected microwave energy and a measurement signal to controller 14 which in turn provides the measurement signal to computer 15 and to a printer 43. Controller 14 includes a computer/controller 44 connected to power meter 40 and receiving the signals therefrom, and, in turn, provides a signal to printer 43 and to computer 15. Computer 15 may be a general purpose digital computer, the equivalent of International Business Machine Corporation's computer. Computer/controller 44 may be of the type manufactured by Hewlett-Packard as their model number H-P85. Associated with computer/controller 44 is a memory 46 having a two-way communication with computer controller 44. Computer/controller 44 also has two-way communication with data/acquisition and control unit 50 which may be of the type manufactured by Hewlett-Packard as their model number H-P3497A. Data acquisition and control unit 50 utilizes the information from computer/controller 44 to send information necessary to the movement and control of microwave transmitter 5 and detector assembly 8.
Referring back to FIG. 1 and to FIGS. 3A, and 3B, the apparatus of microwave transmitter 5, detector assembly 8, and test cell 3 are mounted on apparatus which is basically a combination of units of the type manufactured by Velmex Inc. under their part numbers B6000 and B4000. The combination of two belt coupled B6000 units and a B4000 unit gives the operation two dimensional movement. A housing 54 houses the Gunn source 28 and attenuation pad 30 and is affixed to a rod 57. The electrical connections to DC source 10 and AC source 11 are not shown. Test cell 3 is mounted on a fixed body 60. Antenna 36 is connected to detector 38 supported by arms 62 and 63 with detector 38 being located in a housing 66 mounted to a rod 58 and engaging a screw rod 79. Rods 57 and 58 are maintained in a fixed relationship to each other by end brackets 70, 71 and are controlled to slide through mountings 74 and 75 so as to move antennae 33 and 36 along one direction (x direction) of sample cell 3 by screw rod 79 driven by a stepper motor 80. Members 74 and 75 are controlled to move in another direction (Y direction) by a stepper motor 96 along slides 81 and 81A (not shown) by screw rods 84 and 84A (not shown), respectively.
Referring again to FIG. 2, data/acquisition and control unit 50 controls an X axis preset indexer 84 and in turn receives information as to its index position. An X axis limit switch 86 provides a signal to X axis preset indexer so as to prevent microwave transmitter 5 and detector assembly 8 from exceeding a predetermined x distance. X axis preset indexer 84 provides a signal to X axis stepper motor 88 to control the positioning of the X axis of microwave transmitter 5 and detector assembly 8. Similarly, data/acquisition and control unit 50 provides a signal to and receives a signal from Y axis preset indexer 94. Indexer 94 also receives a signal from Y axis limit switch 98 so as to prevent microwave transmitter 5 and detector assembly 8 from exceeding a Y direction limit. The Y axis preset indexer provides a signal to Y axis stepper motor 96 to control movement in the Y direction. X axis position readout potentiometer 100 and Y axis position readout potentiometer 101 receive energizing voltages from DC power supplies 104 and provides signals to data/acquisition and control unit 50 corresponding to the location of microwave transmitter 5 and detector assembly 8 in the X direction and in the Y direction, respectively.
With reference to FIG. 2 and FIG. 4, the cross-sectional portion of test cell 3 shows a porous formation 120 coated with epoxy 122 and 123. Formation 120 may be an actual earth formation or it may be a fabricated formation. One such fabricated formation is an oil-wet, homogeneous, synthetic consolidated porous material composed of spherical glass beads epoxed together. A matrix of this type is manufactured under the name, Tegraglas Porous Structures, grade 15, which is the least permeable form currently available, has a very uniform pore size of 16-17 μm, a permeability of 1-2 darcies, a porosity of about 30%, and a surface area of only 0.057 m 2 /g. As shown in FIG. 4, the sample cell is substantially square, two opposite corners are chamfered to have a 45° corner, and a simulated wellhead is connected to each chamfered corner. Each wellhead 130 or 132 has internal passageways adapted to accept conventional type chromatograph fittings. The resultant model is 1/4 of a 5-spot pattern; that is, the center well and one corner well of a conventional 5 -spot configuration.
Referring now to FIG. 5, liquid means 20 include pump means 139 which pumps distilled water through valve means 140. Valve means 140 in conjunction with valve means 142 in effect controls which liquid is going to be provided to test cell 3 by way of well 130. In one mode, the output from valve means 140 is provided to a crude oil, or a substitute source 144. One such substitute may be a predetermined mixture of fresh water and 2-propanol. In another mode, valve means 140 provides distilled water to a surfactant source 145, in yet another mode, the output from valve means 140 is provided to a polymer source 146, and in a fourth mode results in valve means 140 output being provided to a brine source 147. Each source, 144, 145, 146 or 147 includes a conventional type free floating piston (not shown) in a container (not shown) having either a crude oil or a substitute, or surfactant, or polymer, or brine. The pumped-in distilled water causes the piston to expel a corresponding amount of liquid (crude oil or its substitute, surfactant, polymer or brine). The output of crude oil source 144, surfactant source 145, polymer source 146 and the brine source 147 are provided to four different inputs of valve means 142. Thus for one mode, pump means 139 in effect pumps crude oil, or its substitute, from crude oil source 144 into test cell 3; in the second mode surfactant from surfactant source 145 is pumped into test cell 3; while in a third mode, pump means 139 in effect pumps polymer from polymer source 146 into test cell 3, and for the fourth mode, brine is pumped into test cell 3.
The liquid from valve means 142 passes through test cell 3 to another valve means 150 in receiving means 24 by way of well 132. Valve means 150 is operated in conjunction with valve means 140 and 142 to pass liquid from test cell 3 to liquid receiving means 156, 156A, 156B or 156C. It should be noted that elements having the same numerical identification with a different suffix are operated and are connected in a similar manner as the element with the same numerical designation without a suffix.
The present invention may be operated in the following manner. Test cell 3 is completely evacuated and the apparatus of the present invention is operated to position microwave transmitter 5 and detector assembly 8 in predetermined locations so as to make microwave measurements at those locations in a predetermined sequence. It does not matter in what sequence the various locations are subjected to the microwave measurements, but obviously it is easier for programing and comparison to use the same sequence whether the test cell 3 is completely evacuated or is in the process of a test. These first measurements correspond to the porous material 120 of test cell 3 being filled only with crude oil. Test cell 3 is then flooded with brine from source 147 through the operation of pump means 139, valve means 140, 142 and 150 and wells 130 and 132, and, a second set of microwave measurements are made and provided to computer 15 so that a second set of measurements correspond to the brine in test cell 3. Pump means 139, valve means 140, 142 and 150 are again operated to inject crude oil, or its substitute, into test cell 3 until only crude oil, or its substitute, leaves test cell 3 and then microwave transmitter 5 and detector assembly 8 are operated to make measurements at the predetermined locations. This third set of measurements corresponds to residual brine to oil at the different locations or in the case of the crude oil substitute, corresponds to an equivalent oil saturation. Pump means 139, valve means 140, 142 and 150 are again operated to inject salt water into test cell 3 until only salt water leaves test cell 3. Microwave transmitter 5 and detector assembly 8 are then operated to make the measurements at the predetermined locations. This fourth set of measurements corresponds to the water flood residual oil at the different locations. The four measurements at each location are used to derive a calibration curve for each location. The calibration curves are generated by computer 15 utilizing conventional curve generation techniques. In some cases, software programs for computer 15 may be purchased from companies that manufactured the computer 15, such as International Business Machine Corporation.
At this point, the actual testing of the chemical flood now commences. It should be noted that in chemical flooding many combinations can be utilized. For example, and this is not truly a chemical flood, brine may be used to drive the oil from the injection well to the producing well, which is a water flood. In chemical flooding techniques a surfactant is used, sometimes driven by brine, or sometimes driven by a polymer. Another alternative to the combination would be a surfactant followed by a polymer driven by brine. Thus, various combinations of liquid chemicals with or without brine may be used in the field. It should be noted that although the term brine is used, it is meant that a water is used, and preferably a water solution with a chemical composition similar to that of the water in the actual oil reservoir or the water that will be used to drive the chemical flood.
In one mode of chemical flooding, pump means 139, valve means 140, 142 and 150 are operated in a sequence so that a slug of surfactant from source 145 followed by a slug of polymer from source 146 and driven by brine is injected into test cell 3 by way of well 130 so that the oil remaining in test cell 3 after the water flood of the calibration process is driven to producing well 132. While this is going on, microwave transmitter 5 and detector assembly 8 are operated in a manner so that they will provide microwave measurements to computer 15 for each location in a predetermined pattern. One such pattern is to divide test cell 3 into a plurality of smaller areas and the microwave transmitter 5 and detector assembly 8 are positioned at each area. Each area is irradiated with microwave energy with detector assembly 8 detecting the energy passing through that area to provide its reading, the sequence being that each area adjacent to well 130 is measured initially and the next adjacent area is read, and so forth progressing away from well 130 so as to scan test cell 3. This scanning operation is repeated throughout the cell 3 will be scanned 20 times in the predetermined sequence during the test time.
The slug sizes of surfactant and polymer are predetermined and may vary from test to test at the desire of the operator. The flow rate of the chemical flood is scaled to approach the reservoir flood velocity. The typical reservoir flood velocity might be one foot per day. Computer 15 can then provide either or both a printout of the microwave readings at each location for each scan and a two-dimensional graph of test cell 3 showing the distribution of the oil as it moves through test cell 3. Again, each graph or plot would be made after each scan during the chemical flood test. It is also feasible to generate the plots or graphs at the end of the chemical flood test since the data is stored during testing.
The present invention as hereinbefore described is a microwave scanner that monitors the chemical flooding of a test cell representative of one quarter of a five spot enhanced oil recovery operation. The present invention is not restricted to five spot operation analysis, but is also applicable to any enhanced oil recovery utilizing chemical flooding with at least an injection well and a producing well. | A method of two dimensional chemical flood testing includes evacuating a porous medium contained in a test cell. The porous medium in the test cell is irradiated with a beam of microwave energy at a plurality of predetermined locations on said test cell. The microwave energy that has passed through the porous medium at each location is detected at the location. The porous medium in the test cell is filled with brine. The irradiating and detecting steps are repeated, the porous medium is then flooded with crude oil, or a substitute, and again the irradiating and detecting steps are repeated. The porous medium is flooded with brine and again the irradiating and detecting steps are repeated. A calibration curve for each location is derived from the detected microwave energy at the location from the prior irradiating and detecting steps. The chemical flood system is tested by flooding the porous medium with the chemical flood system at a predetermined flow rate during which time the irradiating and detecting steps are repeated periodically so that the test cell is periodically scanned in two directions by microwave energy. A two dimensional pattern of the chemical flood is derived for each scan in accordance with the detected microwave energy at each location for the scan and the calibration curves. | 4 |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application is a Continuation-In-Part of U.S. application Ser. No. 14/121,646 filed on Oct. 2, 2014 and claims priority from U.S. Provisional Application Ser. No. 62/493,940 filed on Jul. 21, 2016 both of which are incorporated by reference herein in their entirety.
TECHNICAL FIELD
[0002] The present invention relates to the field of hydraulic tamping devices used to tamp fill material tightly around a pole set into a post hole in the ground.
BACKGROUND OF THE INVENTION
[0003] Wooden utility poles and/or telephone poles are often over forty feet tall and must therefore be set in a deep hole in the ground for stability. Typically, such utility poles are set at least six feet in the ground. Of course, the hole is much larger in diameter than the pole and therefore, dirt must be returned to the hole around the pole little by little and must be tamped or compacted tightly around the pole to provide vertical stability.
[0004] To ease the job of tamping the dirt tightly, hydraulic pole tampers are commonly used. The tool is often used by utility crews to back fill a hole after installing a new power pole or by farmers for tamping fill material around new fence posts.
[0005] The hydraulic pole tampers come in sizes from 60″ to 85″ in length. The tamper is a longitudinal tool with two hydraulic hoses connected to the top end, a hydraulic impact unit housed in a long thin body, and a ram head at the bottom. The driving fluid may be air or oil depending upon the application. In some applications an electric motor driven tamper may be used for tamping. However, in the instant application, the driving fluid is hydraulic oil supplied by a reservoir on a vehicle such as a truck which usually includes a hydraulic oil fluid driven derrick or other drilling equipment for setting posts in holes. Without driving fluid and the hoses, the tool weights often weight nearly 30 pounds.
DESCRIPTION OF THE RELATED ART
[0006] Several tampers are available on the market and typically include a drive having an output shaft, a housing connecting to the drive, and at least a portion of the output shaft extends into the housing. A camming member is attaches to the output shaft. A connecting rod is provided having a first end portion which extends into the housing wherein the first end portion includes an opening. A second end portion of the connecting rod extends out of the housing. The camming member is movably connected to the first end portion. The cam is at the opening. The output shaft is spaced from the opening. The output shaft extends through the opening. A tamper is connected to the second end portion of the connecting rod. The tamper often comprises a base member or shoe of a particular shape such as an oval or curved oval member.
[0007] A typical tamper device is disclosed in U.S. Pat. No. 8,414,221 by Faucher et al. For a “Tamper Device” which is incorporated by reference herein. The tamper device includes a housing, a drive connected the housing, a tamper adapted to reciprocate relative to the housing and apply pressure to a surface, and a wobble connection between the drive and the tamper, wherein the wobble connection comprises a wobble plate, and wherein a first end portion of the tamper is at a side of the wobble plate. The tamper device includes a housing, a drive, a tamper, and a wobble connection. The drive is connected the housing and the tamper is adapted to reciprocate relative to the housing and apply pressure to a surface such as dirt or rock. The wobble connection is between the drive and the tamper, wherein the wobble connection includes a wobble plate with a first end portion of the tamper is at a side of the wobble plate. More particularly, the tamper device includes a housing, a rotatable shaft, a camming member, a connecting rod, and a tamper wherein the rotatable shaft has a first end and a second end. The first end is adapted to be connected to a drive and the second end extends into the housing whereby the camming member is connected to the rotatable shaft. The connecting rod has a first end portion including an opening having a camming member located therein. The first end portion is between and spaced from the first end and the second end of the rotatable shaft. The tamper is connected to a second end portion of the connecting rod. As shown in the figures, the handle is consists of the upper end of the elongated conduit member.
[0008] U.S. Pat. No. 7,540,336 by Steffen describes a vibration isolator for a pneumatic pole or backfill tamper and which is incorporated by reference herein in its entirety suitable for cooperative engagement and mounting a handle kit assembly in accordance with the instant invention. The backfill tamper comprises a handle having a lower end; an elongated conduit member having a lower end and an upper end that is coupled to the lower end of the handle; a piston disposed in the conduit member; a rod coupled to the piston and having a lower end that extends out of the lower end of the conduit member, wherein the piston and rod are configured to reciprocate up and down together in the conduit member; a spring disposed in the conduit member between the piston and the lower end of the conduit member, the spring configured to bias the piston away from the lower end of the conduit member; and a percussion generating mechanism having an upper end coupled to the lower end of the rod, wherein the percussion generating mechanism is configured to receive a supply of pressurized air and convert the supply of pressurized air into a reciprocating percussive force; and
[0000] a supply of pressurized air configured to flow through the conduit member to the percussion generating mechanism, wherein the supply of pressurized air biases on the piston against the bias of the spring; wherein feedback from the reciprocating percussive force of the percussion generating mechanism causes the rod and piston to reciprocate up and down in the conduit member such that the direction of the feedback and the reciprocation of the rod and piston remain in phase with each other; and wherein the reciprocating movements of the rod and piston are dampened by the counteracting forces of the spring and the supply of pressurized air to thereby limit transfer of feedback from the percussion generating mechanism to the handle. In addition, the piston may seal with the interior of the conduit member and divides the interior of the conduit member into upper and lower chambers that change in size as the piston and rod reciprocate up and down in the conduit member. The supply of pressurized air, oil or other fluid flows through the rod to the percussion generating mechanism. The rod may include an aperture through which the pressurized fluid passes via the rod from the conduit member to the rod. The rod may also include an aperture through which the pressurized air passes from the conduit member to the percussion generating mechanism. When the percussion generating mechanism is not operating, the pressurized air causes the rod to advance out of the lower end of the conduit member until an equilibrium state is reached between the pressurized fluid acting on the piston and the spring acting on the piston. A spring disposed between the upper end of the conduit member and the piston can be configured to prevent the piston from engaging the upper end of the conduit member during reciprocation. A second spring can be disposed between the lower end of the conduit member and the piston, the second spring configured to prevent the piston from engaging with the lower end of the conduit member during reciprocation. A shoe may also be coupled to the lower end of the percussion generating mechanism, the shoe configured to engage a tamping surface and transfer percussive force from the percussion generating mechanism to a tamping surface. However as shown in the figures, the conventional handle consists of the upper end of the elongated conduit member which includes connection means such as nipples or other fittings for comparatively engaging one or more hoses from a pressurized fluid generating unit such as a compressor or pump. An electric motor can also be used to power a pole tamper wherein an electric cord extends from a source of electricity such as a generator and attaches to a the upper end of the elongated conduit member.
[0009] The tamper tools work on the same principal as an impact hammer or a jack hammer and therefore is subjected to many intense vertical impacts and lots of jarring and shaking. Consequently, the hoses will become strained and will crack or break loose at the connections at the top of the tool as the tool is used. Failure of the hose causes a loss of hydraulic oil which is a safety concern in that the operator can be sprayed with hot hydraulic oil. Further negative issues associated with failed hoses include expensive downtime and repair and replacement of expensive parts in addition to environmental problems.
[0010] Another downside to the design of the tamping tool relates to the lack of a comfortable and easy to use handle. Conventional longitudinal tamping tools must be long and slender to fit into the bottom of a post hole. The tamping tools are typically hand held by the rounded vertical cylindrical housing as one wood hold a broom handle. Use of the tool includes lifting and moving the tool around the pole at various positions to tamp the fill dirt and rock around the pole. The tamper is then moved and lifted from the hole so additional fill material can be added to the hole to be tamped tight. Thus, the hole containing the pole is filled and tamped in layers a few inches at a time to insure the fill material is tight around the pole and edges of the hole. After extended use, the vibration together with the holding, raising and using this heavy tool along with the hydraulic hoses becomes strenuous and burdensome to a user.
[0011] Another post hole tamping device is available from Greenlee Utility Company as set forth in FIG. 1 as (“PRIOR ART”); however, none of the references provide the handle and adapter improvements made to manipulate the device as set forth in the instant invention. The Greenlee Fairmont hydraulic pole tamper includes a kidney shaped foot or base member. The tool is includes an open an d close center with the valve location at the end of the hose. The flow range of hydraulic fluid is from 4 to 6 gallons per minute and the operating pressure is from 1000 to 2000 psi. The foot size is 2.5×8 inches. The tamper rate of tamping is 1,160 blows per minute at 5 gallon per minute flow rate.
[0012] Other tamper references which may be considered pertinent to examination of the application include U.S. Pat. No. 3,857,448; U.S. Patent Publication 200120312572), (U.S. Pat. No. 8,414,221); and U.S. Pat. No. 8,161,604.
SUMMARY OF THE INVENTION
[0013] A hydraulic pole tamper handle assembly for cooperatively engaging an elongated conduit member of a hydraulic pole tamper comprising an upper end defining an elongated conduit member including means for cooperatively engaging a pair of hydraulic hoses or an electric cord extending upward from a housing, a drive connected the housing, a tamper adapted to reciprocate relative to the housing and apply pressure to a surface, and a wobble connection between the drive and the tamper, wherein the wobble connection comprises a wobble plate, wherein a first end portion of the tamper is at a side of the wobble plate adapted to reciprocate relative to the housing and apply pressure to a surface such as dirt or rock. The hydraulic pole tamper handle assembly comprises, consists essentially of or consists of a handle frame comprising a pair of spaced apart aligned longitudinal arms extending upward from means for mounting to the upper end of the elongated conduit member of the pole tamper, the means for mounting extending around and shielding at least a portion of the means for connecting the hydraulic hoses or the electric cord to the upper end of the elongated conduit member, the longitudinal arms having a top distal end connecting to a handle grip member extending there between. Holding means attaches to the longitudinal arms at a position above the means for connecting the hydraulic hoses or the electric cord for removably securing the hydraulic hoses or the electric cord in vertical alignment with the upper end of the elongated conduit member of the pole tamper. The means for connecting a pair of hose connections of the hydraulic hoses comprises a spring loaded quick connect couplings affixed to the distal end of the hydraulic hose for cooperatively engaging a nipple extending from the upper end of the elongated member of the pole tamper. The means for mounting to the upper end of the elongated conduit member of the pole tamper comprises an open ended cylindrical base defining a sleeve having a diameter sized for coaxial engagement with the upper end of the elongated conduit member of the pole tamper, the sleeve including at least one apertures therein for insertion of the hydraulic hoses or the electric cord extending from the upper end of the elongated member of the pole tamper conduit for protecting the hoses and the user from leaking fluid should one of the hose connections leak or break. Another means for mounting to the upper end of the elongated conduit member of the pole tamper may also comprise at least one split ring defining a collar comprising two semicircular portions adjustably held together by set screws, the collar affixed to a bottom distal end of the longitudinal arms having a diameter sized for coaxial engagement with the upper end of the elongated conduit member of the pole tamper. The holding means attaching to the longitudinal arms at a position above the means for connecting the hydraulic hoses or the electric cord in vertical alignment with the upper end of the elongated conduit member of the pole tamper can comprise a fastener attaching a clamp affixed to the hose or the electric cord to a brace extending between a pair of cross members joining the longitudinal arms. Another holding means attaches to the longitudinal arms at a position above the means for connecting the hydraulic hoses or the electric cord in vertical alignment with the upper end of the elongated conduit member of the pole tamper comprises a holding block having a split body and through bores or channels for removably securing hoses therein, holding block including a pair of set screws for holding cooperatively engaging halves of the hold block together with the hoses held there between, the holding block affixed to a cross member extending between the longitudinal arms of the handle frame. The handle grip member comprises a straight cylindrical member or downward curved member connecting the longitudinal arms.
[0014] As shown in the figures, the handle assembly comprises, consists essentially of or consists of a handle member supported by a frame including a pair of spaced apart, parallel, longitudinal straps of metal extending from attachment means comprising a sleeve, collar, or ring members in coaxially and cooperatively engaging of the upper end of the elongated conduit member.
[0015] In accordance with the present invention, there is provided a pole tamper handle assembly for removable attachment to a hydraulic pole tamper having an upright longitudinal cylindrical housing including a hydraulic impact unit with a hydraulic cylinder and piston and two hydraulic hoses. The piston extends from the bottom of the hydraulic impact unit and has a tamper head fixedly attached thereto. The two hydraulic hoses are fluidly attached to the top end of the hydraulic impact unit. The handle assembly includes hose mounting means such as hose clamps secured to a handle assembly frame. The handle frame is fixedly connected to the top of the longitudinal cylindrical housing by handle attachment means such as a collar, sleeve, cylinder, or rings which fit coaxially around the upper conduit portion of the pole tamper and are secured thereto by bolts, set screws, welding, rivets, or by friction fit.
[0016] The hand frame includes a horizontal handle, an open ended cylindrical base with the first open end at the top of the cylindrical base and the second open end at the bottom of the cylindrical base. The cylindrical base has a diameter sized to fit down onto a top of the longitudinal cylindrical housing. The handle has two ends, the first end of the handle connected to a top edge of the cylindrical base by a first longitudinal strip and the second end of the handle connected to the top edge of the cylindrical base by a second longitudinal strip at a point opposite of the first longitudinal strip. The first and the second longitudinal strips have a gap there between which is bridged by a cross member having two apertures formed therein. The cylindrical base has two apertures formed in the sidewalls thereof. Also included are two hydraulic hose clamps including elastomeric bushings; and two fasteners capable of fastening the two hydraulic hose clamps with hoses into the two apertures formed within the cross member.
[0017] The present invention comprises or consists of a hydraulic pole tamper and handle frame assembly for a hydraulic pole tamper having an upper end defining an elongated conduit member including means for cooperatively connecting a pair of hydraulic hoses extending upward from a housing, a drive connecting the housing, a tamper adapted to reciprocate relative to the housing
[0000] and apply pressure to a surface, and a wobble connection between the drive and the tamper, wherein the wobble connection comprises a wobble plate, wherein a first end portion of the tamper is at a side of the wobble plate adapted to reciprocate relative to the housing and apply pressure to a surface such as dirt or rock. The removable handle assembly cooperatively engages the elongated conduit member of the hydraulic tamper pole and comprises a handle frame having a pair of spaced apart aligned longitudinal arms extending upward from removable means for mounting coaxially affixed to and mounted on an upper end of the elongated conduit member of the pole tamper. A removable means for mounting extends around and shields at least a portion of the means for connecting the hydraulic hoses to the upper end of the elongated conduit member. The longitudinal arms have a pair of spaced apart aligned distal ends connecting to a handle grip member extending there between. Holding means attaches to the longitudinal arms at a position above the means for connecting the hydraulic hoses for removably securing the hydraulic hoses in vertical alignment with the upper end of the elongated conduit member of the pole tamper. The removable means for mounting has a diameter sized and shaped for coaxial engagement with the upper end of the elongated conduit member of the pole tamper. The removable means for mounting extends around and shields at least a portion of the means for connecting the hydraulic hoses to the upper end of the elongated conduit member. The handle frame assembly includes at least one cross member disposed between the longitudinal arms at a position above the means for connecting and removably securing the hydraulic hoses. Hydraulic hose holding means attach to the at least one cross member for holding the hydraulic hoses in vertical alignment with the upper end of the elongated conduit member of the pole tamper. The hydraulic hose holding means attaches to the handle frame at a position above the sleeve, and the hydraulic hoses extending through an upper end of the sleeve removably attaching to the hydraulic hoses means. The means for connecting a pair of hose connections of the hydraulic hoses comprises a spring loaded quick connect couplings affixed to the distal end of the hydraulic hose for cooperatively engaging a nipple extending from the upper end of the elongated conduit member of the pole tamper. A holding means comprises a block including cylindrical through holes mounting to the cross member. The handle grip member comprises a straight cylindrical member connecting the longitudinal strips or a curved member attachable to or integrally formed with the longitudinal strips. The cylindrical base means for mounting is at least one and preferably at least two spaced apart split rings defining collars having semicircular portions adjustably held together by set screws, with the collar affixed to a bottom distal end of the longitudinal arms having a diameter sized for coaxial engagement with the upper end of the elongated conduit member of the pole tamper.
[0018] It is an object of this invention to provide a hydraulic pole tamper with an easy to grip handle at the top end which includes a generally cylindrical handle member adjoining a pair of side arms comprising longitudinal members or straps extending downward for cooperatively engaging an upper distal end of a longitudinal cylindrical body or shaft of a pole tamper.
[0019] It is an object of this invention to provide a hydraulic pole tamper including hose clamps with elastomeric bushings to cushion the hydraulic hoses against the shock of the hydraulic pulses causing the intense longitudinal thrusts of the tamper head.
[0020] It is another object of this invention to provide a hydraulic pole tamper wherein the D-grip handle is part of a handle frame which also includes apertures for the attachment of hose clamps.
[0021] It is another object of the present invention to provide a more ergonomic handle easier to grip and control the tamper.
[0022] It is another object of the present invention to provide a handle enabling the user to control the orientation of the tamper.
[0023] Other objects, features, and advantages of the invention will be apparent with the following detailed description taken in conjunction with the accompanying drawings showing a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] A better understanding of the present invention will be had upon reference to the following description in conjunction with the accompanying drawings in which like numerals refer to like parts throughout the views wherein:
[0025] FIG. 1 is a perspective view of a conventional hydraulic pole tamper;
[0026] FIG. 2 is an enlarged perspective view of the hydraulic hose connections to the pole tamper of FIG. 1 , showing a pair of threaded couplings attaching the hoses connecting to quick disconnect couplings such as HANSON fittings which cooperatively engage nipples extending from the top distal end of the pole tamper;
[0027] FIG. 3 is a front perspective view of the pole tamper including the handle and adapter assembly including the handle frame and hose clamp improvements;
[0028] FIG. 4 is an enlarged in view of the hose clamp with the elastomeric bushing;
[0029] FIG. 5 is an enlarged perspective view of the pole tamper showing the HANSON fittings quick disconnect fittings on the distal ends of the hydraulic hoses extending from the pole tamper hoses;
[0030] FIG. 6 is an enlarged view of the upper portion of the handle and adapter frame including cross members and brace including the apertures for attachment of at least one clamp for securing an electric cord in electrical communication with a pole tamper and an electric power source;
[0031] FIG. 7 is an enlarged view of the upper portion of the modified handle and frame assembly mounted to a hydraulic pole tamper showing the attachment and fasteners fixing the lower cylindrical portion of the handle frame distal end of the upper conduit or shaft of pole tamper;
[0032] FIG. 8 is a perspective view of the handle assembly kit showing the handle and frame mounting to the upper portion of the pole tamper including an alternate hose clamp design for utilizing set screws to removably secure the hoses immovably within a holding block mounted to the frame and an a pair of attachment rings or collars having set screws to removably attach the lower portion of the handle frame to the cylindrical upper body handle portion of a conventional tamper;
[0033] FIG. 9 is an enlarged perspective view of a handle assembly adapter kit including the handle and attachment frame including ring clamps for attachment to the upper end of the elongated conduit member of the pole tamper and a hose retaining or holding block; and
[0034] FIG. 10 is a perspective view of the pole tamper handle assembly having a curved ergonomic handle.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
[0036] When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0037] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
[0038] Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
[0039] In accordance with the present invention, there is provided a hydraulic pole tamper 10 as shown in FIGS. 1-10 . The pole tamper 1 as shown in the figures include a longitudinal cylindrical body 4 , a tamper head 8 at the bottom end, two hydraulic hoses 9 . The improvement comprises the a handle assembly 10 having a frame 12 including a handle grip 14 at the top end with hydraulic hose clamps holding brackets 16 for attachment of hose clips 18 mounting to the hoses 9 for removably mounting the hoses 9 in spaced apart alignment. The nipples 3 extending from the distal end of the upper end of the elongated conduit member 4 from a hose junction 2 are connected to spring loaded quick disconnect couplings 5 such as HANSON fitting attaching to the distal end of the hoses 9 . The upper end of the elongated conduit member defining a longitudinal cylindrical body 4 includes a hydraulic impact unit 7 including a hydraulic cylinder and piston assembly 8 and base tamping member or foot 8 .
[0040] The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
[0041] The handle assembly 12 kit for the pole tamper 1 includes handle frame 12 and handle grip 14 connected to the upper end of the elongated cylindrical body 4 . The handle assembly 10 includes a frame 12 comprising a pair of elongated spaced apart aligned longitudinal straps or arms 20 and 22 extending upward from a cylindrical attachment base defining a sleeve 26 which coaxially and cooperatively engages the upper end of the elongated conduit member 4 of the pole tamper 1 . It is contemplated that the cooperatively engaging member can comprise straps or another portion of the frame extending downward for fixed engagement with the conduit member 4 and held thereto by rivets, bolts, clamps, or a friction fit. The cylindrical base 26 has at least a bottom portion with an inner diameter large enough to firmly slide down over the top end of the longitudinal cylindrical housing 4 . Original equipment manufactures may also weld the base of the handle assembly to the conduit member 4 . As shown in the drawings the frame members 22 , 24 diverge or spread apart. The frame members 122 , 124 may be formed of straight longitudinal members and spread apart at a selected angle to converge at the upper distal end for joining by a downwardly curved handle grip member 114 as shown in FIG. 10 ; or the frame members 22 , 24 may diverge at inwardly and outwardly at selected positions to provide attachment points and an upper end which terminates at an handle grip portion 14 which comprises a generally straight cylindrical member at a top distal end extending across and joining frame arms 20 and 22 as shown in FIG. 7 . The handle grip portion 14 , 114 may be affixed to the frame arms 22 , 24 by bolts, pins, welding, friction fit or other attachment means or be formed as an integral portion of the frame 12 as shown in FIG. 10 .
[0042] As shown in FIGS. 1-10 , the pair of vertically oriented longitudinal members or arms 20 , 22 extend upward from the cylindrical sleeve 26 which slides over and cooperatively engages the pole tamper cylindrical body 4 . The members 20 , 22 are spread apart at a selected acute angle for connecting to a handle grip member 14 of a selected length to enable the user to twist the handle grip and control the orientation of the foot shaped tamper or shoe 8 and to twist the pole tamper 1 or lift it in and out of the hole. The sleeve 26 may comprise a solid member include apertures therein. At least a portion of the top end or a side must include an opening 11 large enough to accommodate connection of the hoses to the nipples or threaded end members 3 extending upward from the hose junction 2 of the distal end of the pole tamper conduit 4 . An important consideration is the capability of the sleeve 26 to protect the hose connection fittings and protects the user from leaking fluid should one of the hose connections leak or break.
[0043] As shown in FIGS. 3 and 5-10 , holding means 13 such as a rods, pins, bolts, or welding connects the handle grip member 14 to the distal ends of the arm members 20 and 22 or the handle grip member 14 can be formed integral with the arms 22 and 24 . The side members 20 and 22 are connected at the ends of the handle 14 and taper downward to the top circular edge of cylinder 26 . A pair of cross members 24 , 25 extend between the arm members 20 and 22 at selected points to provide lateral stability for the frame 12 and attachment points for the hose clips 18 in order to hold the distal ends of the hose 9 in vertical alignment for attachment to the nipples 3 of the pole tamper 1 eliminating stress on the hoses and connection points due to the weight of the hoses during use.
[0044] The cross member 24 , 25 as shown in the FIG. 6 , includes at least one vertical brace 23 connecting the two spaced apart cross members 24 and 25 stretching from side member 20 to side member 22 . A cross members 24 , 25 and/or brace 23 includes clamp holding means 16 defining apertures located at the junction of the center member 23 and the cross member braces 24 and 25 , for the purpose of attaching hose clamps 18 . While the holding means 16 in the instant embodiment is provided by the cross members 24 or 25 or brace 23 , it is contemplated that a loop, hook, flange, or other projection can be affixed by bolts or welding to a longitudinal arm 20 , 22 , 120 , 122 providing a support for affixing the hose clamps 18 thereto. As shown, the upper portion of the handle and adapter frame include cross members and a brace for attachment of at least one clamp for securing an electric cord 21 in electrical communication with an electric pole tamper and an electric power source.
[0045] FIGS. 8-10 show embodiments of the handle assembly 100 frame including a frame 112 and handle grip portion 114 . At least one cross member 124 comprising a metal strip connects longitudinal arms 20 and 22 as shown in FIG. 8 and longitudinal arms 120 and 122 as shown in FIGS. 9 and 10 .
[0046] Two apertures 28 are present in the sidewall of the cylindrical base 26 for fasteners such as screws 30 which rigidly hold the handle frame 12 to the top of the cylindrical housing 4 .
[0047] Two hose clamps 18 are included and used to fasten the hydraulic hoses 9 to the handle frame 12 for lateral support. The hose clamps 18 include elastomeric bushings 19 to cushion the hoses 9 . The clamps 18 are fastened to the handle frame 12 at the apertures 16 with fasteners such as screw and nut combinations. The clamps enable the hose to bent at a 90 degree angle at a section of the hose other than the distal end connecting to the hydraulic tamper connections. Constant vibration and twisting tends to weaken the hoses at the connection joint to the fittings with conventional tamper tools because the connection point and the bending point are at the same junction which leads to premature failure of the connections and hoses, damage to same, downtime, and potential hazards to the tamper user. Applicants improved orientation handle and design minimize the stress on the hoses, the fittings, and the worker orienting and lifting the tamper during use.
[0048] As shown in FIGS. 8 and 9 , the present embodiment can be made available as a kit to retrofit an existing conventional pole tamper wherein the handle is defined by a cylindrical shaft extending upward from the tamping unit. The handle kit 100 includes a generally cylindrical handle 14 which may include a straight handle grip portion 14 or a curved handle grip portion 114 to forming a loop handle. The embodiments shown in FIGS. 8-10 include a hose retaining or holding block 116 having vertical oriented through bores 117 there through. The holding block 116 is attached to a brace 123 by screws or welding and extends between the longitudinal arms 120 and 122 . The holding block comprises two portions which are split providing means for insertion of the hose therein and holding the hoses in position with respect to the handle frame 112 .
[0049] Means for removably mounting to the upper end of the elongated conduit member of the pole tamper comprises at least one split ring defining a collar 126 comprising two semicircular portions adjustably held together by set screws. The collar is affixed to a bottom distal end of the longitudinal arms having a diameter sized for coaxial engagement with the upper end of the elongated conduit member of the pole tamper. One preferred embodiment includes a pair of spaced apart collars or split ring members 102 and 104 are disposed between the proximate ends of the longitudinal arms 120 and 122 forming the lower portion of the handle body. The rings 102 and 104 clamp the handle frame 112 to the upper longitudinal conduit 4 of the post tamper 1 . A cylindrical sleeve 128 may optionally be inserted between the collar 126 and conduit 4 providing a protective shield against leaking hydraulic fluid from a broken line.
[0050] The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom, for modification will become obvious to those skilled in the art upon reading this disclosure and may be made upon departing from the spirit of the invention and scope of the appended claims. Accordingly, this invention is not intended to be limited by the specific exemplification presented herein above. Rather, what is intended to be covered is within the spirit and scope of the appended claims. | A hydraulic pole tamper handle kit having an extended ergonomic handle including a frame and hose clamps to extend the life of the hose by securing the hoses to the frame and to improve the handle, orientation, safety, and usability of the pole tamper. The pole tamper is used to tamp or compact the dirt around a pole which has been set into a hole in the ground to fixedly secure the pole vertically in the ground. | 4 |
This is a continuation of application Ser. No. 775,003, filed Mar. 7, 1977 and now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to derivatives of prostaglandins, more specifically certain 9-deoxy-6,9-epoxy derivatives of specific stereo configuration, and to processes for preparing them.
The prostaglandins and analogs are well-known organic compounds derived from prostanoic acid which has the following structure and atom numbering: ##STR2##
As drawn hereinafter the formulas represent a particular optically active isomer having the same absolute configuration as PGE 1 obtained from mammalian tissues.
In the formulas, broken line attachments to the cyclopentane ring or side chain indicate substituents in alpha configuration, i.e. below the plane of the ring or side chain. Heavy solid line attachments indicate substituents in beta configuration, i.e. above the plane.
For background, see for example Bergstrom et al., Pharmacol. Rev. 20, 1 (1968) and Pace-Asciak et al., Biochem. 10, 3657 (1971).
SUMMARY OF THE INVENTION
It is the purpose of this invention to provide novel products having pharmacological activity. It is a further purpose to provide processes for preparing these products and their intermediates.
Accordingly, there are provided enol ethers of the formula: ##STR3## wherein R 2 is ##STR4## wherein L is (1) --(CH 2 ) d --C(R 22 ) 2
(2) --ch 2 --o--ch 2 --y-- or
(3) --CH 2 CH═CH--
wherein d is zero to 5; R 22 is hydrogen, methyl, or fluoro, being the same or different with the proviso that one R 22 is not methyl when the other is fluoro;
and Y is a valence bond or --(CH 2 ) k --
wherein k is one or 2;
wherein Q is ##STR5## wherein R 8 is hydrogen or alkyl of one to 4 carbon atoms, inclusive; wherein R 1 is
(1) --COOR 3
(2) --ch 2 oh
(3) --ch 2 n(r 9 ) 2 ##STR6## wherein R 3 is (a) alkyl of one to 12 carbon atoms, inclusive, (b) cycloalkyl of 3 to 10 carbon atoms, inclusive, (c) aralkyl of 7 to 12 carbon atoms, inclusive, (d) phenyl, (e) phenyl substituted with one, 2, or 3 chloro or alkyl of one to 4 carbon atoms, inclusive; ##STR7## wherein R 10 is phenyl, p-bromophenyl, p-biphenylyl, p-nitrophenyl, p-benzamidophenyl, or 2-naphthyl; and wherein R 11 is hydrogen or benzoyl; (m) hydrogen, or (n) a pharmacologically acceptable cation; and wherein R 9 is hydrogen or alkyl of one to 4 carbon atoms, inclusive, being the same or different:
wherein R 4 is ##STR8## wherein C g H 2g is alkylene of one to 9 carbon atoms, inclusive, with one to 5 carbon atoms, inclusive, in the chain between --CR 5 R 6 -- and terminal methyl, wherein R 5 and R 6 are hydrogen, alkyl of one to 4 carbon atoms, inclusive, or fluoro, being the same or different, with the proviso that one of R 5 and R 6 is fluoro only when the other is hydrogen or fluoro and the further proviso that neither R 5 nor R 6 is fluoro when Z is oxa (--O--); wherein Z represents an oxa atom (--O--) or C j H 2j wherein C j H 2j is a valence bond or alkylene of one to 9 carbon atoms, inclusive, with one to 6 carbon atoms, inclusive between CR 5 R 6 -- and the phenyl ring; wherein T is alkyl of one to 4 carbon atoms, inclusive, fluoro, chloro, trifluoromethyl, or --OR 7 -- wherein R 7 is alkyl of one to 4 carbon atoms, inclusive, and s is zero, one, 2 or 3, with the proviso that not more than two T's are other than alkyl and when s is 2 or 3 the T's are either the same or different;
wherein V is a valence bond or methylene; wherein W is --(CH 2 ) h -- wherein h is one or two; and
wherein X is
(1) trans--CH═CH--
(2) cis--CH═CH--
(3) --c.tbd.c-- or
(4) --CH 2 CH 2 --;
including the lower alkanoates thereof.
There are likewise provided halo ethers of the formula ##STR9## wherein (a), (b), and (c) represent valence bonds such tha when (a) is alpha, (b) and (c) are both beta, and when (a) is beta, (b) and (c) are both alpha;
wherein R 2 is ##STR10## wherein L is (1) --(CH 2 ) d --C(R 22 ) 2
(2) --ch 2 --o--ch 2 --y-- or
(3) --CH 2 CH═CH--
wherein d is zero to 5; R 22 is hydrogen, methyl, or fluoro, being the same or different with the proviso that one R 22 is not methyl when the other is fluoro;
and Y is a valence bond or --(CH 2 ) k --
wherein k is one or 2;
wherein Q is ##STR11## wherein R 8 is hydrogen or alkyl of one to 4 carbon atoms, inclusive; wherein R 1 is
(1) --COOR 3
(2) --ch 2 oh
(3) --ch 2 n(r 9 ) 2 ##STR12## wherein R 3 is a (a) alkyl of one to 12 carbon atoms, inclusive, (b) cycloalkyl of 3 to 10 carbon atoms, inclusive, (c) aralkyl of 7 to 12 carbon atoms, inclusive, (d) phenyl, (e) phenyl substituted with one, 2, or 3 chloro or alkyl of one to 4 carbon atoms, inclusive; ##STR13## wherein R 10 is phenyl, p-bromophenyl, p-biphenylyl, p-nitroohenyl, p-benzamidophenyl, or 2-naphthyl;
and wherein R 11 is hydrogen or benzoyl; (m) hydrogen, or (n) a pharmacologically acceptable cation; and wherein R 9 is hydrogen or alkyl of one to 4 carbon atoms, inclusive, being the same or different;
wherein R 4 is ##STR14## wherein C g H 2g is alkylene of one to 9 carbon atoms, inclusive, with one to 5 carbon atoms, inclusive, in the chain between --CR 5 R 6 -- and terminal methyl, wherein R 5 and R 6 are hydrogen, alkyl of one to 4 carbon atoms, inclusive, or fluoro, being the same or different, with the provison that one of R 5 and R 6 is fluoro only when the other is hydrogen or fluoro and the further proviso that neither R 5 nor R 6 is fluoro when Z is oxa (--O--); wherein Z represents an oxa atom (--O--) or C j H 2j wherein C j H 2j is a valence bond or alkylene of one to 9 carbon atoms, inclusive, with one to 6 carbon atoms, inclusive between CR 5 R 6 -- and the phenyl ring;
wherein T is alkyl of one to 4 carbon atoms, inclusive, fluoro, chloro, triflouromethyl, or --OR 7 -- wherein R 7 is alkyl of one to 4 carbon atoms, inclusive, and s is zero, one, 2 or 3, with the proviso that not more than two T's are other than alkyl and when s is 2 or 3 the T's are either the same or different;
wherein V is a valence bond or methylene; wherein W is --(CH 2 ) h -- wherein h is one or two; wherein R 21 is iodo, bromo, chloro, or fluoro, and
wherein X is
(1) trans--CH═CH--
(2) cis--CH═CH--
(3) --c.tbd.c-- or
(4) --CH 2 CH 2 --
Within the scope of the prostaglandin derivatives described herein there are represented
(a) PGF.sub.α compounds when R 2 is ##STR15##
(b) 11β-PGF.sub.α compounds when R 2 is ##STR16##
(c) 11-Deoxy-11-keto-PGF.sub.α compounds when R 2 is ##STR17##
(d) 11-Deoxy-11-methylene-PGF.sub.α compounds when R 2 ##STR18##
(e) 11-Deoxy-PGF.sub.α compounds when R 2 is ##STR19##
(f) 11-Deoxy-10,11-Didehydro-PGF.sub.α compounds when R 2 is ##STR20##
(g) 11-Deoxy-11-hydroxymethyl-PGF.sub.α compounds when R 2 is ##STR21##
Formula II includes compounds of the formula ##STR22##
A typical example of the compounds of formula I is represented by the formula ##STR23## and is named as a derivative of PGF 1 : (5E)-9-deoxy-6,9α-epoxy-Δ 5 PGF 1 .
A typical example of the compounds of formula III is represented by the formula: ##STR24## and is named (5S,6R)-5-iodo-9-deoxy-6,9α-epoxy-PGF 1 .
A typical example of the compounds of formuls IV is represented by the formula: ##STR25## and is named (5R,6S)-5-iodo-9-deoxy-6,9α-epoxy-PGF 1 .
The above examples V, VI, and VII are species of the respective formula I, III, and IV compounds wherein R 2 is ##STR26## L is --(CH 2 ) 3 --, Q is ##STR27## R 1 is --COOH, R 4 is n-pentyl, V is a valence bond, W is --CH 2 --, and X is trans -CH═CH--.
The nomenclature for the above compounds and those identified hereinafter follows the conventions applied to prostaglandin-type compounds, See N. A. Nelson, J. Med. Chem. 17, 911 (1974). For "R" and "S" usage see R. S. Cahn, J. Chem. Ed. 41, 116 (1964). For "E" and "Z" designations of double bond stereoisomerism see J. E. Blackwood et al., J. Am. Chem. Soc. 90, 509 (1968).
The formula-I enol ethers are named as derivatives of PGE 1 , regardless of the variations in either of the side chains, V and W in the heterocyclic ring, or the cyclopentane ring system represented by R 2 , following the conventions known and used in the prostaglandin art. Likewise, the formula-II, -III, and -IV halo ethers are named as derivatives of PGF 1 . In formulas I-IV as used herein, W is bonded to the cyclopentane ring at the C-8 position, V at the C-9 position, and X at the C-12 position.
The products of this invention, represented herein by formulas I, II, III, and IV, are extremely potent in causing various biological responses. For that reason, these compounds are useful for pharmacological purposes. A few of those biological responses are: inhibitor of blood platelet aggregation, stimulation of smooth muscle, systemic blood pressure lowering, inhibiting gastric secretion and reducing undesirable gastrointestinal effects from systemic administration of prostaglandin synthetase inhibitors.
Because of these biologial responses, these novel compounds are useful to study, prevent, control, or alleviate a wide variety of diseases and undesirable physiological conditions in mammals, including humans, useful domestic animals, pets, and zoological specimens, and in laboratory animals, for example, mice, rats, rabbits, and monkeys.
These compounds are useful whenever it is desired to inhibit platelet aggregation, to reduce the adhesive character of platelets, and to remove or prevent the formation of thrombi in mammals, including man, rabbits, and rats. For example, these compounds are useful in the treatment and prevention of myocardial infarcts, to treat and prevent post-operative thrombosis, to promote patency of vascular grafts following surgery, and to treat conditions such as atherosclerosis, arteriosclerosis, blood clotting defects due to lipemia, and other clinical conditions in which the underlying etiology is associated with lipid imbalance or hyperlipidemia. Other in vivo applications include geriatric patients to prevent cerebral ischemic attacks and long term prophylaxis following myocardial infarcts and strokes. For these purposes, these compounds are administered systemically, e.g., Intravenously, subcutaneously, intramuscularly, and in the form of sterile implants for prolonged action. For rapid response, especially in emergency situations, the intravenous route of administration is preferred. Doses in the range about 0.01 to about 10 mg. per kg. of body weight per day are used, the exact dose depending on the age, weight, and condition of the patient or animal, and on the frequency and route of administration.
The addition of these compounds to whole blood provides in vitro applications such as, storage of whole blood to be used in heart-lung machines. Additionally whole blood containing these compounds can be circulated through organs, e.g. heart and kidneys, which have been removed from a donor prior to transplant. They are also useful in preparing platelet rich concentrates for use in treating thrombocytopenia, chemotherapy, and radiation therapy. In vitro applications utilize a dose of 0.001-1.0 μg/ml of whole blood.
These compounds are extremely potent in causing stimulation of smooth muscle, and are also highly active in potentiating other known smooth muscle stimulators, for example, oxytocic agents, e.g., oxytocin, and the various ergot alkaloids including derivatives and analogs thereof. Therefore, they are useful in place of or in combination with less than usual amounts of these known smooth muscle stimulators, for example, to relieve the symptoms of paralytic ileus, or to control or prevent atonic uterine bleeding after abortion or delivery, to aid in expulsion of the placenta, and during the puerperium. For the latter purpose, the compound is administered by intravenous infusion immediately after abortion or delivery at a dose in the range about 0.01 to about 50 μg. per kg. of body weight per minute until the desired effect is obtained. subsequent doses are given by intravenous, subcutaneous, or intramuscular injection or infusion during puerperium in the range 0.01 to 2 mg. per kg. of body weight per day, the exact dose depending on the age, weight, and condition of the patient or animal.
These compounds are useful as hypotensive agents to reduce blood pressure in mammals, including man. For this purpose, the compounds are administered by intravenous infusion at the rate about 0.01 to about 50 μg. per kg. of body weight per minute or in single or multiple doses of about 25 to 500 μg. per kg. of body weight total per day.
These prostaglandin derivatives are also useful in mammals, including man and certain useful animals, e.g., dogs and pigs, to reduce and control excessive gastric secretion, thereby reduce or avoid gastrointestinal ulcer formation, and accelerate the healing of such ulcers already present in the gastrointestinal tract. For this purpose, these compounds are injected or infused intravenously, subcutaneously, or intramuscularly in an infusion dose range about 0.1 μg. to about 20 μg. per kg. of body weight per minute, or in a total daily dose by injection or infusion in the range about 0.01 to about 10 mg. per kg. of body weight per day, the exact dose depending on the age, weight, and condition of the patient or animal, and on the frequency and route of administration.
These compounds are also useful in reducing the undesirable gastrointestinal effects resulting from systemic administration of anti-inflammatory prostaglandin synthetase inhibitors, and are used for that purpose by concomitant administration of the prostaglandin derivative and the anti-inflammatory prostaglandin synthetase inhibitor. See Partridge et al., U.S. Pat. No. 3,781,429, for a disclosure that the ulcerogenic effect induced by certain non-steroidal anti-inflammatory agents in rate is inhibited by concomitant oral administration of certain prostaglandins of the E and A series, including PGE 1 , PGE 2 , PGE 3 , 13,14-dihydro-PGE 1 , and the corresponding 11-deoxy-PGE and PGA compounds. Prostaglandins are useful, for example, in reducing the undesirable gastrointestinal effects resulting from systemic administration of indomethacin, phenylbutazone, and aspirin. These are substances specifically mentioned in Partridge et al. as non-steroidal, anti-inflammatory agents. These are also known to be prostaglandin synthetase inhibitors.
The anti-inflammatory synthetase inhibitor, for example indomethacin, aspirin, or phenylbutazone is administered in any of the ways known in the art to alleviate an inflammatory condition, for example, in any dosage regimen and by any of the known routes of systemic administration.
The prostaglandin derivative is administered along with the anti-inflammatory prostaglandin synthetase inhibitor either by the same route of administration or by a different route. For example, if the anti-inflammatory substance is being administered orally, the prostaglanding derivative is also administered orally, or, alternatively, is administered rectally in the form of a suppository or, in the case of women, vaginally in the form of a suppository or a vaginal device for slow release, for example as described in U.S. Pat. No. 3,545,439. Alternatively, if the anti-inflammatory substance is being administered rectally, the prostaglandin derivative is also administered rectally. Further, the prostaglandin derivative can be conveniently administered orally or, in the case of women, vaginally. It is especially convenient when the administration route is to be the same for both anti-inflammatory substance and prostaglandin derivative, to combine both into a single dosage form.
The dosage regimen for the prostaglandin derivative in accord with this treatment will depend upon a variety of factors, including the type, age, weight, sex and medical condition of the mammal, the nature and dosage regimen of the anti-inflammatory synthetase inhibitor being administered to the mammal, the sensitivity of the particular prostaglandin derivative to be administered. For example, not every human in need of an anti-inflammatory substance experiences the same adverse gastrointestinal effects when taking the substance. The gastrointestinal effects will frequently vary substantially in kind and degree. But it is within the skill of the attending physician or veterinarian to determine that administration of the anti-inflammatory substance is causing undesirable gastrointestinal effects in the human or animal subject and to prescribe an effective amount of the prostaglandin derivative to reduce and then substantially to eliminate those undesirable effects.
These compounds are also useful in the treatment of asthma. For example, these compounds are useful as bronchodilators or as inhibitors of mediators, such as SRS-A, and histamine which are released from cells activated by an antigen-antibody complex. Thus, these compounds control spasm and facilitate breathing in conditions such as bronchial asthma, bronchitis, bronchietasis, pneumonia and emphysema. For these purposes, these compounds are administered in a variety of dosage forms, e.g., orally in the form of tablets, capsulses, or liquids; rectally in the form of suppositories; parenterally, subcutaneously, or intramuscularly, with intravenous administration being preferred in emergency situations; by inhalation in the form of aerosols or solutions for nebulizers; or by insufflation in the form of powder. Doses in the range of about 0.01 to 5 mg. per kg. of body weight are used 1 to 4 times a day, the exact dose depending on the age, weight, and condition of the patient and on the frequency and route of administration. For the above use these prostaglandins can be combined advantageously with other anti-asthamtic agents, such as sympathomimetics (isoproterenol, phenylephrine, ephedrine, etc.); xanthine derivatives (theophylline and aminophylline); and corticosteroids (ACTH and prednisolone).
These compounds are effectively administered to human asthma patients by oral inhalation or by aerosol inhalation.
For administration by the oral inhalation route with conventional nebulizers or by oxygen aerosolization it is convenient to provide the instant active ingredient in dilute solution, preferably at concentrations of about 1 part of medicament to form about 100 to 200 parts by weight of total solution. Entirely conventional additives may be employed to stabilize these solutions or to provide isotonic media, for example, sodium chloride, sodium citrate, citric acid, sodium bissulfite, and the like can be employed.
For administration as a self-propelled dosage unit for administering the active ingredient in aerosol form suitable for inhalation therapy the composition can comprise the active ingredient suspended in an inert propellant (such as a mixture of dichlorodifluoromethane and dichlorotetrafluoroethane) together with a co-solvent, such as ethanol, flavoring materials and stabilizer. Instead of a co-solvent there can also be used a dispensing agent such as oleyl alcohol. Suitable means to employ the aerosol inhalation therapy technique are described fully in U.S. Pat. No. 2,868,691 for example.
These compounds are useful in mammals, including man, as nasal decongestants and are used for this purpose in a dose range of about 10 μg. to about 10 mg. per ml. of a pharmacologically suitable liquid vehicle or as an aerosol spray, both for topical application.
These compounds are also useful in treating peripheral vascular disease in humans. The term peripheral vascular disease as used herein means disease of any of the blood vessels outside of the heart and to disease of the lymph vessels, for example, frostbite, ischemic cerebrovascular disease, artheriovenous fistulas, ischemic leg ulcers, phlebitis, venous insufficiency, gangrene, hepatorenal syndrome, ductus arteriosus, non-obstructive mesenteric ischemia, arteritis lymphangitis and the like. These examples are included to be illustrative and should not be construed as limiting the term peripheral vascular disease. For these conditions the compounds of this invention are administered orally or parenterally via injection or infusion directly into a vein or artery, intra-venous or intra-arterial injections being preferred. The dosages of these compounds are in the range of 0.01-1.0 μg./kg. administered by infusions at an hourly rate or by injection on a daily basis, i.e. 1-4 times a day, the exact dose depending on the age, weight, and condition of the patient and on the frequency and route of administration. Treatment is continued for one to five days, although three days is ordinarily sufficient to assure long-lasting therapeutic action. In the event that systemic or side effects are observed the dosage is lowered below the threshold at which such systemic or side effects are observed.
These compounds are accordingly useful for treating peripheral vascular diseases in the extremities of humans who have circulatory insufficiencies in said extremities, such treatment affording relief of rest pain and induction of heating of ulcers.
For a complete discussion of the nature of and clinical manifestations of human peripheral vascular disease and the method previously known of its treatment with prostaglandins see South African Patent No. 74/0149 referenced as Derwent Farmdoc No. 58,400V. See Elliott, et al., Lancet, Jan. 18, 1975, pp. 140-142.
These compounds are useful in place of oxytocin to induce labor in pregnant female animals, including man, cows, sheep, and pigs, at or near term, or in pregnant animals with intrauterine death of the fetus from about 20 weeks to term. For this purpose, the copound is infused intravenously at a dose of 0.01 to 50 μg. per kg. of body weight per minute until or near the termination of the second stage of labor, i.e., expulsion of the fetus. These compounds are especially useful when the female is one or more weeks post-mature and natural labor has not started, or 12 to 60 hours after the membranes have ruptured and natural labor haas not yet started. An alternative route of administration is oral.
These compounds are further useful for controlling the reproductive cycle in menstruating female mammals, including humans. By the term menstruating female mammals is meant animals which are mature enough to menstruate, but not so old that regular menstruation has ceased. For that purpose the prostaglandin derivative is administered systemically at a dose level in the range 0.01 mg. to about 20 mg. per kg. of body weight of the female mammal, advantageously during a span of time starting approximately at the time of ovulation and ending approximately at the time of menses or just prior to menses. Intravaginal and intrauterine routes are alternate methods of administration. Additionally, expulsion of an embryo or a fetus is accomplished by similar administration of the compound during the first or second trimester of the normal mammalian gestation period.
These compounds are further useful in causing cervical dilation in pregnant and nonpregnant female mammals for purposes of gynecology and obstetrics. In labor induction and in clinical abortion produced by these compounds, cervical dilation is also observed. In cases of infertility, cervical dilation produced by these compounds is useful in assisting sperm movement to the uterus. Cervical dilation by prostaglandins is also useful in operative gynecology such as D and C (Cervical Dilation and Uterine Curettage) where mechanical dilation may cause perforation of the uterus, cervical tears, or infections. It is also useful for diagnostic procedures where dilation is necessary for tissue examination. For these purposes, the prostaglandin derivative is administered locally or systemically.
The prostaglandin derivative, for example, is administered orally or vaginally at doses of about 5 to 50 mg. per treatment of an adult female human, with from one to five treatments per 24 hour period. Alternatively the compound is administered intramuscularly or subcutaneously at doses of about one to 25 mg. per treatment. The exact dosages for these purposes depend on the age, weight, and condition of the patient or animal.
These compounds are further useful in domestic animals as an abortifacient (especially for feedlot heifers), as an aid to estrus detection, and for regulation or synchronization of estrus. Domestic animals include horses, cattle, sheep, and swine. The regulation or synchronization of estrus allows for more efficient management of both conception and labor by enabling the herdsman to breed all his females in short pre-defined intervals. This synchronization results in a higher percentage of live births than the percentage achieved by natural control. The prostaglandin is injected or applied in a feed at doses of 0.1-100 mg. per animal and may be combined with other agents such as steroids. Dosing schedules will depend on the species treated. For example, mares are given the prostaglandin derivative 5 to 8 days after ovulation and return to estrus. Cattle are treated at regular intervals over a 3 week period to advantageously bring all into estrus at the same time.
These compounds increase the flow of blood in the mammalian kidney, thereby increasing volume and electrolyte content of the urine. For that reason, these compounds are useful in managing cases of renal dysfunction, especially those involving blockage of the renal vascular bed. Illustratively, these compounds are useful to alleviate and correct cases of edema resulting, for exaple, from massive surface burns, and in the management of shock. For these purposes, these compounds are preferably first administered by intravenous injection at a dose in the range 10 to 1000 μ g. per kg. of body weight or by intravenous infusion at a dose in the range 0.1 to 20 μg. per kg. of body weight per minute until the desired effect is obtained. Subsequent doses are given by intravenous, intramuscular, or subcutaneous injection or infusion in the range 0.05 to 2 mg. per kg. of body weight per day.
These prostaglandin derivatives ae useful for treating proliferating skin diseases of man and domesticated animala, including psoriasis, atopic dermatitis, non-specific dermatitis, primary irritant contact dermatitis, allergic contact dermatitis, basal and squamous cell carcinomas of the skin, lamellar ichthyosis, epidermolytic hyperkeratosis, premalignant sun-induced keratosis, non-malignant keratosis, acne, and seborrheic dermatitis in humans and atopic dermatitis and mange in domesticated animals. These compounds alleviate the symptoms of these proliferative skin diseases: psoriasis, for example, being alleviated when a scale-free psoriasis lesion is noticeably decreased in thickness or noticeably but incompletely cleared or completely cleared.
For these purposes, these compounds are applied topically as compositions including a suitable pharmaceutical carrier, for example as an ointment, lotion, paste, jelly, spray, or aerosol, using topical bases such as petrolatum, lanolin, polyethylene glycols, and alcohols. These compounds, as the active ingredients; constitute from about 0.1% to about 15% by weight of the composition, preferably from about 0.5% to about 2%. In addition to topical administration, injection may be employed, as intradermally, intra- or perilesionally, or subcutaneously, using appropriate sterile saline compositions.
These compounds are useful as antiflammatory agents for inhibiting chronic inflammation in mammals including the swelling and other unpleasant effects thereof using methods of treatment and dosages generally in accord with U.S. Pat. No. 3,885,041, which patent is incorporated herein by reference.
These enol-ether and halo ether compounds of this invention cause many of the biological responses known for the older prostaglandin compounds. In addition, they are surprisingly more specific with regard to potency and have a substantially longer duration of biological activity. They have the further advantage that they may be administered effectively orally, sublingually, intravaginally, buccally, or rectally as well as by the usual methods. Each of these novel analogs is therefore useful in place of the known prostaglandin F.sub.α -type compounds for at least one of the pharmacological purposes known for them, and is surprisingly and unexpectedly more useful for that purpose because it has a different and narrower spectrum of biological activity than the known prostaglandin, and therefore is more specific in its activity and causes smaller and fewer undesired side effects than the known prostaglandin. Moreover, because of its prolonged activity, fewer and smaller doses of these novel compounds can frequently be used to attain the desired result.
There are further provided the various processes for preparing the enol ethers of formula I and the halo ethers of formulas II-IV.
Thus, for the formula-I enol ether compounds, one process comprises the steps of starting with a compound of the formula ##STR28## wherein L, Q, R 1 , R 2 , R 4 , V, W, and X are as defined above, and
(a) halogenating and cyclizing to form halo compounds of the formula ##STR29## wherein L, Q, R 1 , R 2 , R 4 , V, W, and X are as defined above, and
(a) halogenating and cyclizing to form halo compounds of the formula ##STR30## wherein L, Q, R 1 , R 2 , R 4 , V, W, and X are as defined above, and wherein R 20 is iodo or bromo;
(b) subjecting the product of step "a" to dehydrohalogenation with a tertiary amine to form the enol ether; and
(c) separating the product.
In another process for the enol ether compounds, the formula-III and -IV halo compounds are subjected to dehydrohalogenation with a reagent selected from the group consisting of sodium or potassium superoxide, sodium or potassium carbonate, sodium or potassium hydroxide, sodium or potassium benzoate, sodium or potassium acetate, sodium or potassium trifluoroacetate, sodium or potassium bicarbonate, silver acetate, and a tetraalkylammonium superoxide of the formula (R 12 ) 4 NO 2 wherein R 12 is alkyl of one to 4 carbon atoms, inclusive to form the enol ethers.
Still another process for the enol ether compounds comprises the steps of starting with the (5Z) isomers represented by the formula ##STR31## wherein L, Q, R 1 , R 2 , R 4 , V, W, and X are as defined above, and
(a) isomerizing to an equilibrium mixture consisting of said starting compound and said enol ether product in a solution containing a catalytic amount of iodine, and
(b) separating the components of that mixture.
The formula-III and -IV halo compounds obtained in the processes above are useful not only as intermediates for preparing the novel enol ethers but also for their pharmacological activity. A few of their biological responses are: inhibition of blood platelet aggregation, stimulation of smooth muscle, systemic blood pressure lowering, inhibiting gastric secretion and reducing undesirable gastrointestinal effects from systemic administration of prostaglandin synthetase inhibitors.
In addition to the iodo and bromo compounds of formula-III and -IV, the corresponding chloro and fluoro compounds are herein disclosed as useful compounds for the same purposes. They are included in general formulas corresponding to III and IV wherein R 20 is replaced with R 21 which includes iodo, bromo, chloro, and fluoro. The chloro and fluor compounds are readily prepared from the iodo or bromo compounds by methods known in the art, for example halide exchange in a solvent such as dimethylformamide. See for example Harrison et al., Compendium of Organic Synthetic Methods, Wiley-Interscience, N.Y., 1971, Section 145.
Reference to Chart A, herein, will make clear the steps for preparing the formula-I, -III, and -IV compounds of this invention.
In Chart A, the terms have the same meaning as defined above, namely: ##STR32## L is
(1) --(CH 2 ) d --C(R 22 ) 2
(2) --ch 2 --o--ch 2 --y-- or
(3) --CH 2 CH═CH--
wherein d is zero to 5; R 22 is hydrogen, methyl, or fluoro, being the same or different with the proviso that one R 22 is not methyl when the other is fluoro; and Y is a valence bond or --(CH 2 ) k --
wherein k is one or 2;
Q is ##STR33## wherein R 8 is hydrogen or alkyl of one to 4 carbon atoms, inclusive: R 1 is
(1) --COOR 3
(2) --ch 2 oh
(3) --ch 2 n(r 9 ) 2 ##STR34## wherein R 3 is (a) alkyl of one to 12 carbon atoms, inclusive, (b) cycloalkyl of 3 to 10 carbon atoms, inclusive, (c) aralkyl of 7 to 12 carbon atoms, inclusive, (d) phenyl, (e) phenyl substituted with one, 2, or 3 chloro or alkyl of one to 4 carbon atoms, inclusive; ##STR35## wherein R 10 is phenyl, p-bromophenyl, p-biphenylyl, p-nitrophenyl, p-benzamidophenyl, or 2-naphthyl;
and wherein R 11 is hydrogen or benzoyl; (m) hydrogen, or (n) a pharmacologically acceptable cation; and wherein R 9 is hydrogen or alkyl of one to 4 carbon atoms, inclusive, being the same or different;
R 4 is ##STR36## wherein C g H 2g is alkylene of one to 9 carbon atoms, inclusive, with one to 5 carbon atoms, inclusive, in the chain betwen --CR 5 R 6 -- and terminal methyl, wherein R 5 and R 6 are hydrogen, alkyl of one to 4 carbon atoms, inclusive, or fluoro, being the same or different, with the proviso that one of R 5 and R 6 is fluoro only when the other is hydrogen or fluoro and the further proviso that neither R 5 nor R 6 is fluoro when Z is oxa (--O--); wherein Z represents an oxa atom (--O--) or C j H 2j wherein C j H 2j is a valence bond or alkylene of one to 9 carbon atoms, inclusive, with one to 6 carbon atoms, inclusive between CR 5 R 6 -- and the phenyl ring;
wherein T is alkyl of one to 4 carbon atoms, inclusive, fluoro, chloro, trifluoromethyl, or --OR 7 -- wherein R 7 is alkyl of one to 4 carbon atoms, inclusive, and s is zero, one, 2 or 3, with the proviso that not more than two T's are other than alkyl and when s is 2 or 3 the T's are either the same or different;
V is a valence bond or methylene;
W is --(CH 2 ) h -- wherein h is one or two; and
X is
(1) trans--CH═CH--
(2) cis--CH═CH--
(3) --c.tbd.c-- or
(4) --CH 2 CH 2 --
Examples of alkyl of one to 12 carbon atoms, inclusive, are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and isomeric forms thereof. Examples of cycloalkyl of 3 to 10 carbon atoms, inclusive, which includes alkyl-substituted cycloalkyl, are
cyclopropyl,
2-methylcyclopropyl,
2,2-dimethylcyclopropyl,
2,3-diethylcyclopropyl,
2-butylcyclopropyl,
cyclobutyl,
2-methylcyclobutyl,
3-propylcyclobutyl,
2,3,4-triethylcyclobutyl,
cyclopentyl,
2,2-dimethylcyclopentyl,
3-pentylcyclopentyl,
3-tert-butylcyclopentyl,
cyclohexyl,
4-tert-butylcyclohexyl,
3-isopropylcyclohexyl,
2,2-dimethylcyclohexyl,
cyclopentyl,
cyclooctyl,
cyclononyl,
and cyclodecyl.
Examples of aralkyl of 7 to 12 carbon atoms, inclusive, are
benzyl,
phenethyl,
1-phenylethyl,
2-phenylpropyl,
4-phenylbutyl,
3-phenylbutyl,
2-(1-naphthylethyl),
and 1-(2-naphthylmethyl).
Exampls of phenyl substituted by one to 3 chloro or alkyl of one to 4 carbon atoms, inclusive are
p-chlorophenyl,
m-chlorophenyl,
o-chlorophenyl,
2,4-dichlorophenyl,
2,4,6-trichlorophenyl,
p-tolyl,
m-tolyl,
o-tolyl,
p-ethylphenyl,
p-tert-butylphenyl,
2,5-dimethylphenyl,
4-chloro-2-methylphenyl,
and 2,4-dichloro-3-methylphenyl.
Examples of alkylene of one to 9 carbon atoms, inclusive, with one to 5 carbon atoms, inclusive, in the chain, within the scope of C g H 2g as defined above, are methylene, ethylene, trimethylene, tetramethylene, and pentamethylene, and those alkylene with one or more alkyl substituents on one or more carbon atoms thereof, e.g. --CH(CH 3 )--, --C(CH 3 ) 2 --, --CH(CH 2 CH 3 )--, --CH 2 --CH(CH 3 )--, --CH(CH 3 )--CH(CH 3 )--, --CH 2 --C(CH 3 ) 2 --, --CH 2 --CH(CH 3 )--CH 3 --, --CH 2 --CH 2 --CH(CH 2 CH 2 CH 3 )--, --CH(CH 3 )--CH(CH 3 )--CH 2 --CH 2 --, --CH 2 --CH 2 --CH 2 --C(CH 3 ) 2 --CH 2 , and --CH 2 --CH 2 --CH 2 --CH 2 --CH(CH 3 --. Examples of alkylene of one to 9 carbon atoms, inclusive, substituted with zero, one, or 2 fluoro, with one to 6 carbon atoms in the chain, within the scope of C j H 2j as defined above, are those given above for C g H 2g and hexamethylene, including hexamethylene with one of more alkyl substituents on one or more carbon atoms thereof, and including those alkylene groups with one or 2 fluoro substituents on one or 2 carbon atoms thereof, e.g. --CHF--CH 2 --, --CHF--CHF--, --CH 2 --CH 2 --CF 2 --, --CH 2 --CHF--CH 2 --, --CH 2 --CH 2 --CF(CH 3 )--, --CH 2 --CH 2 --CF 2 --CH 2 --, --CH(CH 3 )--CH 2 --CH 2 --CHF--, --CH 2 --CH 2 --CH 2 --CH 2 --CF 2 --, --CHF--CH 2 --CH 2 --CH 2 --CH 2 --CHF--, --CF 2 --CH 2 --CH 2 --CH 2 --CH 2 --CH 2 --, --CH 2 --CH 2 --CH 2 --CF 2 --CH 2 --CH 2 --, and --CH 2 --CH 2 --CH 2 --CH 2 --CH 2 --CF 2 .
Examples of ##STR37## as defined above are
phenyl,
(o-, m-, or p-)tolyl,
(o-, m-, or p-)ethylphenyl,
(o-, m-, or p-)propylphenyl,
(o-, m-, or p-)butylphenyl,
(o-, m-, or p-)isobutylphenyl,
(o-, m-, or p-)tert-butylphenyl,
2,3-xylyl,
2,6-diethylphenyl,
2-ethyl-p-tolyl,
4-ethyl-o-tolyl,
5-ethyl-m-tolyl,
2-propyl-(o-, m-, or p-)tolyl,
4-butyl-m-tolyl,
6-tert-butyl-m-tolyl,
4-isopropyl-2,6-xylyl,
3-propyl-4-ethylphenyl,
(2,3,4-, 2,3,5-, 2,3,6-, or 2,4,5-)trimethylphenyl,
(o-, m-, or p-)fluorophenyl,
2-fluoro-(o-, m-, or p-)tolyl,
4-fluoro-2,5-xylyl,
(2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)difluorophenyl,
(o-, m-, or p-)chlorophenyl,
2-chloro-p-tolyl,
(3-, 4-, 5-, or 6-)chloro-o-tolyl,
4-chloro-2-propylphenyl,
2-isopropyl-4-chlorophenyl,
4-chloro-3,5-xylyl,
(2,3-, 2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)dichlorophenyl,
4-chloro-3-fluorophenyl,
(3-, or 4-)chloro-2-fluorophenyl,
α,α, α-trifluoro-(o-, m-, or p-)tolyl,
(o-, m-, or p-)methoxyphenyl,
(o-, m-, or p-)ethoxyphenyl,
(4- or 5-)chloro-2-methoxyphenyl, and
2,4-dichloro(5- or 6-)methoxyphenyl.
Referring to Chart A, the starting materials of formula VIII are known in the art or are readily available by processes known in the art. For example, as to 5,6-trans-PGF 2 α. see U.S. Pat. No. 3,759,978.
Other 5,6-trans-PGF 2 α analogs and derivatives within the scope of Formula VIII are available from the corresponding PGF 2 α compounds having the 5,6-cis configuration, for example by isomerization to an equilibrium mixture containing the 5,6-trans isomer by ultraviolet radiation in the presence of a diaryl sulfide or disulfide. See above cited U.S. Pat. No. 3,759,978.
For typical PGF 2 α -type compounds useful as sources of the Formula-VIII 5,6-trans compounds, reference is made as follows: as to 15-methyl- and 15-ethyl-PGF 2 α, see U.S. Pat. No. 3,728,382; as to 16,16-dimethyl-PGF 2 α, see U.S. Pat. No. 3,903,131; as to 16,16-difluoro-PGF 2 α compounds, see U.S. Pat. No. 3,962,293 and 3,969,380; as to 16-phenoxy-17,18,19,20-tetranor-PGF 2 α, see Derwent Farmdoc No. 73279U and British Spec. No. 1,409,841; as to 17-phenyl-18,19,20-trinor-PGF 2 α, see U.S. Pat. No. 3,987,087; as to 11-deoxy-PGF 2 α, see Derwent Farmdoc No. 10695V and British Spec. No. 1,434,620; as to PGD 2 , see U.S. Pat. No. 3,767,813; as to 2a, 2b -dihomo-PGF 2 α, see Derwent Farmdoc No. 61412S and U.S. Pat. No. 3,852,316 and 3,974,195; as to 3-oxo-PGF 2 α, see U.S. Pat. No.3,923,861; as to 3-oxa-17 -phenyl-18,19,20-trinor-PGF 2 α, see U.S. Pat. No. 3,931,289; as to substituted phenacyl esters, see Derwent Farmdoc No. 16828X and German Offen. 2,535,693; as to substituted phenyl esters, see U.S. Pat. No. 3,890,372; as to C-1 alcohols, i.e. 2-decarboxy-2-hydroxymethyl compounds, see U.S. Pat. No. 3,636,120; as to C-2 tetrazolyl derivatives, see U.S. Pat. No. 3,883,513 and 3,932,389; as to Δ2-PGF 2 α see Derwent farmdoc No. 46497W and Ger. Offen. 2,460,285; as to 2,2-dimethyl-PGF 2 α analogs, see Derwent Farmdoc No. 59033T and Ger. Offen. 2,209,039; as to 9-deoxy-9-hydroxy-methyl-PGF 2 α, see U.S. Pat. No. 3,950,363; as to 11β-PGF 2 α compounds, see U.S. Pat. No. 3,890,371; as to 11-deoxy-11-hydroxymethyl-PGF 2 α, see U.S. Pat. Nos. 3,931,282 and 3,950,363; as to 16-methylene-PGF 2 α, see Derwent Farmdoc No. 19594W and U.S. Pat. No. 3,953,495; as to 17,18-didehydro-PGF 2 α compounds, see U.S. Pat. No. 3,920,726; as to 3-(or 4-)oxa-17,18-didehydro-PGF 2 α -compounds, see U.S. Pat. 3,920,723; as to 15-oxo-PGF 2 α, see U.S. Pat. No. 3,728,382; as to 15-deoxy-PGF 2 α, see Derwent Farmdoc No. 9239W; as to 13,14-cis compounds, see U.S. Pat. No. 3,932,479; as to 11-deoxy-15-deoxy-PGF 2 α see Derwent Farmdoc No. 5694U and U.S. Pat. No. 3,853,951; as to ω-homo-PGF 2 α compounds, see Derwent Farmdoc No. 4728W; and as to 2,2-difluoro-PGF 2 α compounds, see U.S. Pat. No. 4,001,300.
As to 2-decarboxy-2-amino-PGF 2 α compounds, see the Appendix attached hereto, with a disclosure taken from a prior-filed, commonly-owned U.S. Pat. application.
In step "a" of Chart A, the starting material VIII is subjected to iodination and cyclization to yield the formula-III and -IV iodo compounds. For this purpose there is used either an aqueous system containing iodine, potassium iodide, and an alkali carbonate or bicarbonate, or an organic solvent system such as methylene chloride containing iodide in the presence of an alkali metal carbonate. The reaction is carried out at temperatures below 25° C., preferably about 0°-5° C. for 1-20 hr. Thereafter the reaction is quenched with sodium sulfite and sodium carbonate and the formula-III and -IV compounds separated from the reaction mixture.
The formula-III and -IV compunds wherein R 20 is bromo are conveniently prepared using N-bromosuccinimide in a solvent such as methylene chloride at temperatures between 0° C. and 30° C.
The formula-III and -IV compounds, which are isomeric at C-5 and C-6, are separated by conventional methods of fractionation, column chromatography, or liquid-liquid extraction. Especially useful is high pressure liquid chromatography on silica gel. The less polar compound is identified as the Formula-iv (5R,6S) isomer and the more polar comound as the Formula-III (5S,6R) isomer.
In steps "b" and "b'", either isomer of the halo ether us converted to the desired Formula-I product. Accordingly, a mixture of those halo ether isomers will likewise yield a Formula-I product.
The halo compound III or IV is converted to the formula-I enol ether by contacting it with a dehydroiodination reagent. For such reagents see, for example, Fieser and Fieser, "Reagents for Organic Synthesis" p.1308, John Wiley and Sons, Inc., New York, N.Y. (1967). Preferred for the reaction are tertiary amines and reagents selected from the group consisting of sodium or potassium superoxide, sodium or potassium carbonate, sodium or potassium hydroxide, sodium or potassium benzoate, sodium or potassium acetate, sodium or potassium trifluoroacetate, sodium or potassium bicarbonate, silver acetate, and a tetraalkylammonium superoxide of the formula (R 12 ) 4 NO 2 wherein R 12 is alkyl of one to 4 carbon atoms, inclusive
Of the tertiary amines, preferred amines are
1,5-diazabicyclo [4.3.0] nonene-5("DBN"),
1,4-diazabicyclo [2.2.2] octane ("DABCO"), and
1,5-diazabicyclo [5.4.0 undecene-5 ("BDU").
other preferred reagents are sodium or potassium superoxide and tetramethylammonium superoxide. For further information on the superoxides see Johnson and Nidy, J. Org. Chem. 40, 1680 (1975). For larger scale preparation the electrochemical generation of superoxide is recommended. See Dietz et al., J. Chem. Soc. (B), 1970, pp. 816-820.
The dehydroiodination step is carried out in an inert organic medium such as dimethylformamide and is followed by TLC to show the disappearance of starting material. The reaction proceeds at 25° C. and can be accelerated at 40°-50° C.
In working up the reaction mixture it is advantageous to maintain basic conditions, e.g. with triethylamine, to avoid acidic decomposition or structural changes of the product. Purification is achieved by crystallization and consequent separation from impurities or starting material left in the mother liquor, or by column chromatography. For chromatographic separation a column of magnesium silicate ("Fluorisol ®") is preferred over silica gel. Decomposition of the product is avoided by pretreating the column with triethylamine.
Ester groups such as the p-phenylphenacyl group on the C-1 carboxyl or 4-bromobenzoate on C-11 and C-15 hydroxyls are unchanged by the transformations of Chart A, and, if present on the formula-VIII starting mterial, are also present on the formula-I product. For the final products of formula I which are esters the peferred method of preparation is from formula-I, -III or -IV halo compounds which are corresponding esters.
Esters may also be prepared from the corresponding acids of formula I, III, and IV, i.e., wherein R 1 is --COOH, by methods known in the art. For example, the alkyl, cycloalkyl, and aralyl esters are prepared by interaction of said acids with the appropriate diazohydrocarbon. For example, when diazomethane is used, the methyl ester are produced. Similar use of diazoethane, diazobutane, 1-diazo-2-ethylhexane, diazocyclohexane, and phenyldiazomethane, for example, gives the ethyl, butyl, 2-ethylhexyl, cyclohexyl, and benzyl esters, respectively. Of these esters, the methyl or ethyl are preferred.
Esterification with diazohydrocarbons is carried out by mixing a solution of the diazohydrocarbon in a suitable inert solvent, preferably diethyl ether, with the acid reactant, advantageously in the same or a different inert diluent. After the esterification reaction is complete, the solvent is removed by evaporation, and the ester purified if desired by conventional methods, preferably by chromatography. It is preferred that contact of the acid reactants with the diazohydrocarbon be no longer than necessary to effect the desired esterification, preferably about one to about ten minutes, to avoid undesired molecular changes. Diazohydrocarbons are known in the art or can be prepared by methods known in the art. See, for example Organic Reactions, John Wiley and Sons, Inc., New York, N.Y., Vol. 8, pp. 389-394 (1954).
The formula I, III and IV compounds prepared by the processes of this invention are transformed to lower alkanoates by interaction with a carboxyacylating agent, preferably the anhydride of a lower alkanoic acid, i.e., an alkanoic acid of one to 8 carbon atoms, inclusive. For example, use of acetic anhydride gives the corresponding diacetate. Similar use of propionic anhydride, isobutyric anhydride, and hexanoic acid anhydride gives the corresponding carboxyacylates.
The carboxyacylation is advantageously carried out by mixing the hydroxy compound and the acid anhydride, preferably in the presence of a tertiary amine such as pyridine or triethylamine. A substantial excess of the anhydride is used, preferably about 10 to about 1,000 moles of ahydride per mole of the hydroxy compound reactant. The excess anhydride serves as a reaction diluent and solvent. An inert organic diluent, for example dioxane, can also be added. It is preferred to use enough of the tertiary amine to neutralize the carboxylic acid produced by the reaction, as well as any free carboxyl groups present in the hydroxy compound reactant.
The carboxyacylation reaction is preferably carried out in the range about 0° To about 100° C. The necessary reaction time will depend on such factors as the reaction temperature, and the nature of the anhydride; pyridine, and a 25° C. reaction temperature, a 12 to 24-hour reaction time is used.
The carboyacylated product is isolated from the reaction mixture by conventional methods. For example, the excess anhydride is decomposed with water, and thw resulting mixture acidified and then extracted with a solvent such as diethyl ether. The desired carboxylate is recovered from the diethyl ether extract by evaporation. The carboxylate is then purified by conventional methods, advantageously by chromatography.
Salts of these formula-I, -III and -IV compounds are prepared with pharmacologically acceptable metal cations, ammonium, amine cations, or quaternary ammonium cations. Several methods are employed, for example using either the formula-VIII starting materials in their salt form or, when considered as intermediates in preparing the formula-I products; the formula-III or -IV compounds in their salt form. In addition, the free acids may be prepared by careful acidification of a soluble alkali metal salt of a formula I, III or IV compound and extraction into an organic solvent to avoid prolonged contact with an acidic aqueous medium, thereupon the desired salt may be prepared from the stoichiometric amount of hydroxide, carbonate, or bicarbonate in the case of metal cations, of the amine or hydroxide in the case of other salts.
Especially useful for administration because of their ease of dissolving are sodium salts. They are obtained from the formula-I, -III, or -IV esters by saponification with equivalent amounts of sodium hydroxide in a solvent, preferably an alcohol-water solution, thereafter lyophilizing (freeze-drying) the mixture to obtain the powdered product. The starting esters are preferably alkyl esters, of which methyl or ethyl are especially preferred.
Especially preferred metal cations are those derived from the alkali metals, e.g., lithium, sodium, and potassium, and from the alkaline earth metals, e.g., magnesium and calcium, although cationic forms of other metals, e.g., aluminum, zinc, and iron, are within the scope of this invention.
Pharmacologically acceptable amine cations are those derived from primary, secondary, or tertiary amines. Examples of suitble amines are methylamine, dimethylamine, trimethylamine, etylamine, dibutylamine, triisopropylamine, N-methylhexylamine, decylamine, dedecylamine, allylaine, crotylamine, cyclopentylamine, dicyclohexylamine, benzylamine, dibenzylamine, α-phenylethylamine, β-phenylethylamine, ethylenediamine, diethylenetriamine, and like aliphatic, cycloaliphatic, and araliphatic amines containing up to and including about 18 atoms, as well as heterocyclic amines, e.g., piperidine, morphiline, pyrrolidine, piperazine, and lower-alkyl derivatives thereof, e.g., 1-methylpiperidine, 4-ethylmorpholine, 1-isopropylpyrrolidine, 2-methylpyrrolidine, 1,4-dimethylpiperazine, 2-methylpiperidine, and the like, as well as amines containing water-solubilizing or hydrophilic groups, e.g., mono-, di-, and triethanolamine, ethyldiethanolamine, N-butylethanolamine, 2-amino-1-butanol, 2-amino-2-ethyl-1,3-propanediol, 2-amine-2-methyl-1 -propanol, tris(hydroxymethyl)aminomethane, N-phenylethanolamine, N-(p-tert-amylphenyl)diethanolamine, galactamine, N-methyl-glucamine, N-methylglycosamine, ephedrine, phenylephrine, epinephrine, procaine, and the like.
Examples of suitable pharmacologically acceptable quaternary ammonium cations are tetramethylammonium, tetraethylammonium, benzyltrimethylammonium, phenyltriethylammonium, and the like.
As discussed above, the compounds of formula I, III, and IV are administered in various ways for various purposes; e.g., intravenously, intramuscularly, subcutaneously, orally, intravaginally, rectally, buccally, sublingually, topically, and in the form of sterile implants for prolonged action.
For intravenous injection or infusion, sterile aqueous isotonic solutions are preferred. For that purpose, it is preferred because of increased water solubility that R 3 in the formula I, III, and IV compounds be hydrogen or a pharmacologically acceptable cation. For subcutaneous or intramuscular injection, sterile solutions or suspensions of the acid, salt, or ester form in aqueous or non-aqueous media are used. Tablets, capsules, and liquid preparations such as syrups, elixirs, and simple solutions, with the usual pharmaceutical carriers are used for oral sublingual administration. For rectal or vaginal administration suppositories prepared as known in the art are used. For tissue implants, a sterile tablet or silicone rubber capsule or other object containing or imprenated with the substance is used.
In Chart B, is shown a process for preparing 6-keto-PGF 1 α compounds. These compounds, not the subject of this invention, are known to have pharmocological utility including inhibition of blood platelet aggregation, stimulation of smooth muscle, and systemic blood pressure lowering. The formula-1 enol ethers are converted to the formula-IX compounds by contact with an aqueous acid, preferably ##STR38## in an organic solvent. Examples of suitable acids are dilute hydrochloric, perchloric, and sulfuric acids.
In Chart C are shown process steps yielding the formula-III halo ethers in the formula-XII amide form, useful per se or as starting materials for formula-I amides by step "b" of Chart A.
In step "a" of Chart C of the formula-X ester is saponified and acidified to form the formula-XI free acid. The conditions and reagents are those employed in similar transformations known in the art.
In step "b" the formula-XII amide is formed from acid XI, for example by contact with either ammonia or amine in the presence of isobutylchloroformate, preferably in a solvent such as acetonitrile.
In Chart D is shown the equilibration of the formula-I and formula-XIII compounds, starting with either one and yielding a mixture consisting of the two compounds. The reaction goes smoothly in the presence of a catalytic amount(0.1-2.0 mg.) of iodine and is preferably run in a solvent containing a trace (0.1%) of a tertiary amine such as triethylamine. Thereafter the mixture is separated into its components, for example by preparative thin layer chromatography. The formula-XIII compounds are known to be useful for pharmological purposes. One of the formula-XIII compounds is designated by the term "prostacyclin".
It should be understood that although the Charts have formulas drawn with a specific configuration for the reactants and products, the procedural steps are intended to apply also to mixtures, including racemic mixtures or mixtures of enantiomeric forms. Accordingly, it is intended that the compounds are claimed not only in their purified form but also in mixtures, including racemic mixtures or mixtures of the enantiomeric forms. ##STR39##
If optically active products are desired, optically active starting materials or intermediates are employed or, if racemic starting materials or intermediates are used, the products are resolved by methods known in the art for prostaglandins. The products formed from each step of the reaction are often mixtures and, as known to one skilled in the art, may be used as such for a succeeding step or, optionally separated by conventional methods of fractionation, column chromatography, liquid-liquid extraction, and the like, before proceeding.
To obtain the optimum combination of biological response specificity, potency, and duration of activity, certain compounds within the scope of formulas I-IV are preferred. For example it is preferred that Q be ##STR40## wherein it is especially preferred that R 8 be hydrogen or methyl.
Another preference, for the compounds of formulas I, III, and IV as to R 1 , is that R 3 in --COOR 3 be either hydrogen or alkyl of one to 12 carbon atoms, inclusive. it is further preferred that R 3 be alkyl of one to 4 carbon atoms, inclusive, especially methyl or ethyl, for optimum absorption on administration. For the compounds of formula-II, it is preferred that R 3 not be hydrogen but rather an alkyl ester or a salt of pharmologically acceptable cation.
For purposes of stability on long storage, it is also preferred that R 3 be amido-substituted phenyl or substituted phenacyl, as illustrated herein.
For oral administration it is preferred that R 1 be ##STR41## and that R 9 be hydrogen or methyl.
When R 4 is ##STR42## it is preferred that C g H 2 g be alkylene of 2, 3, or 4 carbon atoms, and especially that it be trimethylene. It is further preferred that R 5 and R 6 be hydrogen, methyl, ethyl, or fluoro, being the same or different. It is further preferred, when R 5 and R 6 are not hydrogen, that both R 5 and R 6 be methyl for fluoro.
When R 4 is ##STR43## it is preferred that "s" be either zero or one. When "s" is not zero, it is preferred that T be methyl, chloro, fluoro, trifluoromethyl, or methoxy with meta or para attachement to the phenyl ring. When Z is oxa (--O--), it is preferred that R 5 and R 6 be hydrogen, methyl, or ethyl, being the same or different. It is further preferred, when R 5 and R 6 are not hydrogen, that both R 5 and R 6 be methyl. When Z is C j H 2j , it is preferred that C j H 2j be a valence bond, methylene, or ethylene.
As to variations in R 2 , it is preferred that R 2 be ##STR44##
As to variations in R 4 , it is preferred that R 4 be n-pentyl 1,1-dimethylpentyl 1,1-difluoropentyl ##STR45##
As to variations in L, it is preferred that L be --(CH 2 ) 3 --, --(CH 2 ) 4 --, or --(CH 2 ) 5 --, especially --(CH 2 ) 3 --.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE, attached herewith, depicts the proton ( 1 H) nuclear magnetic resonance (NMR) spectrum of one of the formula-I compounds described herein, namely (5E)-9-Deoxy-6,9α-epoxy-Δ 5 -PGF 1 , methyl ester. Significant peaks are at 5.53, 4.67, 4.52, 4.02, 3.83, and 3.67δ.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is further illustrated, but not limited to, the following examples.
All temperatures are in degrees centigrade.
Infrared absorption spectra are recorded on a Perkin-Elmer model 421 infrared spectrophotometer. Except when specified otherwise, undiluted (neat) samples are used.
The NMR spectra are recorded on a Varian A-60, A-60D, T-60 or XL-100 spectrophotometer is deuterochloroform solutions with tetramethylsilane as an internal standard.
Mass spectra are recorded on a Varian Model MAT CH7 Mass Spectrometer, a CEC Model 110B Double Focusing High Resolution Mass Spectrometer, or an LKB Model 9000 Gas Chromatograph-Mass Spectrometer (ionization voltage 22 or 70 ev.).
"Brine", herein refers to an aqueous saturated sodium chloride solution.
"DBN", herein, refers to 1,5-diazabicyclo[4.3.0]nonene-5.
"DABCO", herein refers to 1,4-diazabicyco[2.2.2]octane.
"DBU", herein, refers to 1,5-diazabicyclo[5.4.0]undecene-5.
"E" and "Z", herein, follow Blackwood et al., cited above.
"Florisil®", herein, is a chromatographic magnesium silicate produced by the Floridin Co. See Fieser et al. "Reagents for Organic Synthesis" p. 393 John Wiley and Sons, Inc., New York, N.Y. (1967).
"TLC", herein, refers to thin layer chromatography.
Silica gel chromatography, as used herein, is understood to include elution, collection of fractions, and combinations of those fractions shown by TLC to contain the desired product free of starting material and impurities.
"Concentrating", as used herein, refers to concentration under reduced pressure, preferably at less than 50 mm. and at temperatures below 35° C.
"Dicyclohexyl-18-crown-6", herein, refers to a compound reported by C. J. Pedersen, J. Am. Chem. Soc. 89, 7017 (1967)).
"Lower alkanoate", herein, refers to an ester of an alkanoic acid of one to 8 carbon atoms, inclusive.
Preparation 1
(5R,6R)-5-lodo-9-deoxy-6,9α-epoxy-PGF 1 , Methyl Ester and (5S,6S)-5-lodo-9-deoxy-6,9α-epoxy-PGF 1 , Methyl Ester.
A suspension of PGF 2 α, methyl ester (3.0 g.) in 60 ml. of water is treated with sodium carbonate (1.7 g.) and cooled in an ice bath. To the resulting solution is added potassium iodide (2.7 g.) and iodine (4.14 g.) and stirring continued for 3 hr. at about 0° C. Thereafter sodium sulfite (2.5 g.) and sodium carbonate (0.8 g.) are added to decolorize the mixture. After a few minutes the mixture is extracted with chloroform. The organic phase is washed with brine, dried over sodium sulfate, and concentrated to yield mainly the title compound, an oil, which is further purified by silica gel chromatography, eluting with methylene chloride (15-50%)-acetone to yield the less polar (5S,6S) tital compound, 0.29 g. and the more polar (5R,6R) title compound, 3.36 g.
Preparation 2
(5Z)-9-Deoxy-6,9α-epoxy-Δ 5 -PGF 1 , Methyl Ester (Formula XIII, Chart D: R 2 is ##STR46## L is --(CH 2 ) 3 --, Q is ##STR47## R 1 is --COOCH 3 , R 4 is n-pentyl, V is a valence bond, W is methylene, and X is trans--CH═CH--).
A mixture of potassium superoxide (0.427 g.). dicyclohexyl-18-crown-6 (0.75 g.) and 10 ml.) of dimethyformamide is stirred at about 25° C. for 0.25 hr. A solution of (5R, 6R)-5-iodo-9-deoxy-6,9α-epoxy-PGF 1 , methyl ester (Preparation 1, 0.494 g.) in 1 ml. of dimethylformamide is then added, while stirring. After 5 min. the reaction mixture is quenched in ice-water and extracted with diethyl eter. The organic phase is dried and concentrated. The residue is subjected to column chromatography on Florisil ® pretreated with treithylamine (5%)-methylene chloride. The product is eluted with ethyl acetate-hexane-triethylamine (50:50:0.1) to give the formula-XIII title compound, 0.152 g., having R f 0.69 (TLC on silica gel in acetone-hexane (1:1), and having proton NMR peaks at 5.54, 4.58, 4.16, 4.00, 3.75, 3.65, and 0.87 δ.
EXAMPLE 1
(5s,6r)-5-iodo-9-dexoy-6,9α-epoxy-PGF 1 , Methyl Ester Formula III: R 2 is ##STR48## L is --(CH 2 ) 3 --, Q is ##STR49## R 1 is --COOCH 3 , R 4 is n-pentyl, R 20 is iodo, V is a valence bond, W is methylene, and X is trans--CH═CH--) and
(5R,6S)-5Iodo- 9-deoxy-6,9α-epoxy-PGF 1 , Methyl Ester (Formula IV: wherein L, Q, R 1 , R 2 , R 4 , R 20 , V, W, and X are as above).
Refer to Chart A. A solution of the formula-VIII 5,6-trans-PGF 2 α, methyl ester (U.S. Pat. No. 3,823,180, 2.58 g.) in 50 ml. of methylene chloride is treated, while ice-cold, with sodium carbonate (1.48 g.) and iodine (1.90 g.) for one hr., thereafter at about 25° C. for another hr. The mixture is poured into 100 ml. of ice-water containing sufficient excess sodium thiosulfate to decolorize the mixture. The organic phase is separated and later combined with chloroform extracts of the aqueous phase, dried over magnesium sulfate, and concentrated. The residue (3.48 g.) is subjected to high pressure liquid chromatography on silica gel, eluting with acetone (15-25%)-methylene chloride (and again chromatographing the fraction containing a mixture of products) to give the less polar Formula-IV (5R,6S) title compound, 0.352 g., having proton NMR peaks at 5.55, 3.5- 4.5, 3.67, and 0.90 δ; mass spectral peaks (TMS derivative) at 638.2327, 623, 607, 567, 548, 517, 511, 510, 477, 451, 199, and 173; and R f 0.42 (TLC on silica gel in acetone (20%)-methylene chloride); and the more polar Formula-III (5S,6R) title compound, 2.151 g., having proton NMR peaks at 5.57, 4.52, 3.6-4.3, 3.70, and 0.92δ; mass spectral peaks (TMS derivative) at 638.2333, 623, 607, 567, 548, 517, 511, 510, 477, 451, 199, and 173; and R f 0.36 (TLC on silica gel in acetone (20%)-methylene chloride).
Following the procedures of Example 1, but replacing the formula-VIII starting material with the following formula-VIII compounds or their derivatives within the scope of R 1 :
5,6-trans-15-methyl-PGF 2 α
5,6-trans-15-ethyl-PGF 2 α
5,6-trans-16,16-dimethyl-PGG 2 α
5,6-trans-16,16-difluoro-PGF 2 α
5,6-trans-16-phenoxy-17,18,19,20-tetranor-PGF 2 α
5,6-trans-17-phenyl-18,19,20-trinor-PGF 2 α
5,6-trans-11-deoxy-PGF 2 α
2a,2b-Dihomo-5,6-trans-PGF 2 α
3-oxa-5,6-trans-17-phenyl-18,19,20-trinor-PGF 2 α
there are obtained the corresponding formula-III and -IV iodo compounds.
EXAMPLE 2
(5e)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 , Methyl Ester (Formula I: R 2 is ##STR50## L is --(CH 2 ) 3 --, Q is ##STR51## R 1 is --COOCH 3 , R 4 is n-pentyl, V is a valence bond, W is methylene, and X is trans--CH═CH--).
Refer to Chart A. A mixture of potassium superoxide (0.88 g.), dicyclohexyl-18-crown-6 (cf. C. J. Pedersen, J. Am. Chem. Soc. 89, 7017 (1967)) and 20 ml. of dimethylformamide is stirred, first at about 25° C. for 0.5 hr., then at ice temperature while adding a solution of formula-III (5S,6R)-5-iodo-9-deoxy-6,9α-epoxy-PGF 1 , methyl ester (Example 1, 1.74 g.) in 3 ml. of dimethylformamide. After 0.5 hr., the reaction mixture is poured into ice-water and extracted with diethyl ether. The organic phase is dried and concentrated to a residue, taken up in dimethylformamide and treated with additional potassium superoxide (approximately 0.26 g.) in 6 ml. of dimethylformamide at about 25° C. for 10 min. The residue obtained as above is subjected to column chromatography on Florisil ® pretreated with triethylamine (5%)-methylene chloride. The product is eluted with ethyl acetate-hexane-triethylamine (50:50:0.1) to give the formula-I title compound, 0.258 g., having m.p. 66°-69° C.; R f 0.65 (TLC on silica gel in acetone-hexane (1:1)); having proton NMR peaks at 5.53, 4.67, 4.52, 4.02, 3.83, 3.67, and 0.88 δ; having 13 C NMR peaks at 174.3, 155.9, 136.4, 131.3, 95.9, 83.0, 77.3, 72.9, 55.5, 51.4, 45.6, 40.4, 37.2, 33.4, 31.7, 30.5, 26.9, 25.7, 25.2, 22.6, and 14.0 ppm. relative to tetramethylsilane; and having infrared absorption at 3420, 1740, and 1690 cm -1 . For more detail of the proton NMR spectrum see the FIGURE attached hereto. On the basis of that spectrum the structure and name are assigned.
Following the procedure of Example 2, but replacing potassium superoxide with each of the following reagents, the title compound is likewise obtained:
sodium superoxide
tetramethylammonium superoxide
sodium carbonate
potassium carbonate
sodium hydroxide
potassium hydroxide
sodium benzoate
potassium benzoate
sodium acetate
potassium acetate
sodium trifluoroacetate
potassium trifluoroacetate
sodium bicarbonate
potassium bicarbonate and
silver acetate.
EXAMPLE 3
(5e)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 , Methyl Ester (Formula I: as defined in Example 2).
Refer to Chart A. A mixture of the formula-III (5S,6R)-5-iodo-9-deoxy-6,9α-epoxy-PGF 1 , methyl ester (Example 1, 1.0 g.), 1.0 ml. of 1,5diazabicyclo[4.3.0]-nonene-5-("DBN") and 60 ml. of benzene is heated at about 42° C. for 20 hr. Thereupon 0.5 ml. of DBN is added and the heating continued for 6 hr. more. The mixture is left stirring at about 25° C. for 60 hr., then heated again for 8 hr. at 40°-50° C. The reaction mixture is cooled, washed with ice water mixed with a few drops of triethylamine, dried over magnesium sulfate, and concentrated. The residue is subjected to column chromatography as described in Example 2 to yield the title compound having the properties set forth in Example 2.
Following the procedure of Example 3 but replacing DBN of that example with 1,4-diazobicyclo[2.2.2]octane ("DABCO") or 1,5-diazabicyclo[5.4.0]undecene-5 ("DBU") there is obtained the same formula-I product.
Following the procedures of Examples 2 and 3, but replacing the formula-III iodo compound therein with each of the formula-III iodo compounds described following Example 1 there are obtained the corresponding formula-I compounds, including the derivatives within the scope of R 1 . Thus there are obtained, for example, analogs of (5E)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 , methyl ester, having the following structural features:
15-methyl-,
15-ethyl-,
16,16-dimethyl-,
16,16-difluoro-,
16-phenoxy-17,18,19,20-,
17-phenyl-18,19,20-,
11-deoxy-,
2a,2b-dihomo-, and
3-oxa-17-phenyl-18,19,20-trinor-.
EXAMPLE 4
(5e)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 , Sodium Salt (Formula I: R 2 is ##STR52## L is --(CH 2 ) 3 --, Q is ##STR53## R 1 is --COONa, R 4 is n-pentyl, V is a valence bond, W is methylene, and X is trans--CH═CH--).
A solution of the formula-I (5E)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 , methyl ester (Example 2, 0.041 g.) in 5 ml. of methanol is treated with a solution of 2.5 ml. of 0.05 N. sodium hydroxide in 2.5 ml. of water at about 25° C. for 20 hr. The solution shown by TLC (1:1 acetone-hexane) to be free of starting material, is frozen at about -75° C. and lyophilized to yield the formula-I title compound as a viscous gum.
EXAMPLE 5
(5e)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 (Formula I: R 2 is ##STR54## L is --(CH 2 ) 3 --, Q is ##STR55## R 1 is --COOH, R 4 is n-pentyl, V is a valence bond, W is methylene, and X is trans--CH═CH--).
A solution of the formula-I (5E)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 , sodium salt (Example 4, 0.10 g.) in 5 ml. of water is treated with a solution of 1 N. potassium hydrogen sulfate in water at ice bath temperature for 1 minute. The solution is immediately thereafter extracted with diethyl ether. The organic phase is dried and concentrated to yield the formula-I title compound.
EXAMPLE 6
6-keto-PGF 1 α, Methyl Ester (Formula IX: R 2 is ##STR56## L is --(CH 2 ) 3 --, Q is ##STR57## R 1 is --COOCH 3 , R 4 is n-pentyl, V is a valence bond, W is methylene and X is trans--CH═CH--).
Refer to Chart B. A solution of the formula-I (5E)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 , methyl ester (Example 2 0.096 g.) in 10 ml. of tetrahydrofuran containing 25 ml. of 0.2 M potassium chloride and 6.5 ml. of 0.2 M hydrochloric acid is stirred at about 25° C. for 1.5 hr. Thereafter 10 ml. of brine is added and the mixture extracted with ethyl acetate. The organic phase is dried and concentrated. The residue (0.088 g.) is subjected to high pressure liquid chromatography on silica gel, eluting with acetone (30%)-hexane, to yield the formula-IX title compound, 0.031 g., having m.p. 70°-74° C.
EXAMPLE 7
(5s,6r)-5-bromo-9-deoxy-6,9α-epoxy-PGF 1 , Methyl Ester Formula III: R 2 is ##STR58## L is --(CH 2 ) 3 --, Q is ##STR59## R 1 is --COOCH 3 , R 4 is n-pentyl, R 20 is bromo, V is a valence bond, W is methylene, and X is trans--CH═CH--); and
(5R,6S)-5-Bromo-9-deoxy-6,9α-epoxy-PGF 1 , Methyl Ester (Formula-IV: wherein R 2 , L, Q, R 1 , R 4 , R 20 , V, W, and X are as defined above).
Refer to Chart A. A solution of the formula-VIII 5,6-trans-PGF 2 α, methyl ester, (U.S. Pat. No. 3,823,180, 3.68 g.) in 50 ml. of methylene chloride is treated, while ice-cold, with N-bromosuccinimide (1.78 g.) for one hr., thereafter at about 25° C. for another hr. The mixture is poured into 100 ml. of water containing sodium chloride. The organic phase is separated and later combined with methylene chloride extracts of the aqueous phase, dried over magnesium sulfate, and concentrated. The residue (4.2 g.) is subjected to chromatography on silica gel, eluting with ethyl acetate (50-75%)-hexane and with ethyl acetate to give the less polar Formula-IV 5R,6S, title compound and the more polar Formula-III 5S,6R title compound.
EXAMPLE 8
(5s,6r)-5-iodo-9-deoxy-6,9α-epoxy-PGF 1 (Formula III: R 2 is ##STR60## L is --(CH 2 ) 3 --, Q is ##STR61## R 1 is --COOH, R 4 is n-pentyl, R 20 is iodo, V is a valence bond, W is methylene, and X is trans--CH═CH--).
A solution of the formula-III methyl ester (Example 1, 1.0 g.) in 30 ml. of methanol is treated with 20 ml. of 3 N aqueous potassium hydroxide at about 0° C. for about 5 min., then at about 25° C. for 2 hr. The mixture is acidified with 45 ml. of 2 N potassium acid sulfate and 50 ml. of water to pH 1.0, saturated with sodium chloride and extracted with ethyl acetate. The organic phase is washed with brine, dried over sodium sulfate and concentrated to an oil, 1.3 g. The oil is subjected to silica gel chromatography, eluting with acetone-dichloromethane (30:70 to 50:50) to yield the formula-III acid title compound.
EXAMPLE 9
(5e)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 , Amide (Formula I: R 2 is ##STR62## L is --(CH 2 ) 3 --, Q is ##STR63## R 1 is ##STR64## R 4 is n-pentyl, V is a valence bond, W is methylene, and X is trans--CH═CH--).
1. There is first prepared the formula-III (5S,6R)-5-iodo-9-deoxy-6,9α-epoxy-PGF 1 , amide. A solution of the formula-III 5S,6R)-5-iodo-9-deoxy-6,9α-epoxy-PGF 1 acid compound (Example 8, 0.50 g.) in 10 ml. of dry acetone is treated at -10° C. while stirring, with 0.3 ml. of triethylamine and 0.3 ml. of isobutylchloroformate. After 5 min. there is added a saturated solution of ammonia in acetonitrile, thereafter continuing the reaction at about 25° C. for 10 min. The mixture is filtered and the filtrate concentrated to an oil. The residue is taken up in ethyl acetate, washed with water, dried over magnesium sulfate, and concentrated. The residue is subjected to silica gel chromatography, eluting with acetone (40- 100%)-methylene chloride to yield the desired amide.
II. The title compound is next prepared. Following the procedure of Example 2, but replacing the (5S,6R)-5-iodo-9-deoxy-6,9α-epoxy-PGF 1 -methyl ester starting material of that example with the product of Part I above, there is obtained the formula-I title compound.
III. Likewise, following the procedure of Example 3 but replacing the 5S,6R)-5-iodo-9-deoxy-6,9α-epoxy-PGF 1 , methyl ester starting material of that example with the product of Part I above, there is also obtained the formula-I title compound.
EXAMPLE 10
(5e)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 , Methylamide (Formula I: R 1 is ##STR65## L is --(CH 2 ) 3 --, Q is ##STR66## R 1 is ##STR67## R 4 is n-pentyl, V is a valence bond, W is methylene, and X is trans--CH═CH--).
I. Following the procedure of Example 9 but replacing the solution of ammonia in acetonitrile with a solution of methylamine in acetonitrile (3 ml. of a 3 molar solution), there is obtained the corresponding formula-III compound, i.e. (5S,6R)-5-iodo-9-deoxy-6,9α-epoxy-PGF 1 , methylamide.
II. The title compound is next prepared, following the procedure of Example 2, but replacing the (5S,6R)-5-iodo-9-deoxy-6,9α-epoxy-PGF 1 , methyl ester starting material of that example with the product of Part I above.
III. Likewise following the procedure of Example 3 but replacing the (5S,6R)-5-iodo-9-deoxy-6,9α-epoxy-PGF 1 , methyl ester starting material of that example with the product of Part I above, there is also obtained the -formula-I title compound.
EXAMPLE 11
(5e)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 , Methyl Ester (Formula I: As defined in Example 1).
Refer to Chart D. A solution of (5Z)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 , methyl ester (Preparation 2, 4 mg.) in 1 ml. of ethyl acetate (25%)-hexane containing 0.1% triethylamine is treated with iodine (about 1 mg.) and left at about 25° C. for several hours. The reaction mixture is then found to contain the title compound, having R f 0.65 (TLC on silica gel in acetone-hexane (1:1).
In a larger preparation the title compound is isolated after silica gel chromatography on preparative TLC plates.
Likewise following the procedures of Example 11 but replacing the (5Z) starting material with the (5E) compound, i.e. (5E)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 , methyl ester (Example 2), there is obtained an equilibrium mixture of the (5E) and (5Z) compounds from which the (5Z)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 , methyl ester is isolated. | Prostaglandin (PG 1 ) derivatives having a 9-deoxy-6,9-epoxy feature together with either a 5-halo or 5,6-didehydro feature are disclosed, for example ##STR1## including processes for preparing them and the appropriate intermediates; said derivatives having pharmacological activity. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of application Ser. No. 09/617,199, filed Jul. 17, 2000, now U.S. Pat. No. 6,488,717, issued Sep. 10, 2002.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to field emission display (FED) devices. More particularly, this invention relates to methods and apparatuses for improving beamlet uniformity in FED devices.
2. Description of the Related Art
Field emission display (FED) devices are an alternative to cathode ray tube (CRT) and liquid crystal display (LCD) devices for computer displays. CRT devices tend to be bulky with high power consumption. While LCD devices may be lighter in weight with lower power consumption relative to CRT devices, they tend to provide poor contrast with a limited angular display range. FED devices provide good contrast and wide angular display range and are lightweight with low power consumption. An FED device typically includes an array of pixels, wherein each pixel includes one or more cathode/anode pairs. Thus, it is convenient to use the terms “column” and “row” when referring to individual pixels or columns or rows within the array.
FIG. 1 illustrates a portion of an FED device 10 produced in accordance with conventional micro-tipped cathode structure. The FED device 10 includes a faceplate 12 and a baseplate 20 , separated by spacers 32 . The spacers 32 support the FED device 10 structurally when the region 34 in between the faceplate 12 and the baseplate 20 is evacuated. The faceplate 12 includes a glass substrate 14 , a transparent conductive anode layer 16 and a cathodoluminescent layer or phosphor layer 18 . The phosphor layer 18 may include any known phosphor material capable of emitting photons in response to bombardment by electrons.
The baseplate 20 includes a substrate 22 with a row electrode 24 , a plurality of micro-tipped cathodes 26 , a dielectric layer 28 and a column-gate electrode 30 . The baseplate 20 is formed by depositing the row electrode 24 on the substrate 22 . The row electrode 24 is electrically connected to a row of micro-tipped cathodes 26 . The dielectric layer 28 is deposited upon the row electrode 24 . A column-gate electrode 30 is deposited upon the dielectric layer 28 and acts as a gate electrode for the operation of the FED device 10 .
The substrate 22 may be comprised of glass. The micro-tipped cathodes 26 may be formed of a metal such as molybdenum, or a semiconductor material such as silicon, or a combination of molybdenum and silicon. Micro-tipped cathodes 26 may also be formed with a conductive metal layer (not shown) formed thereon. The conductive metal layer may be comprised of any well-known low work function material.
The FED device 10 operates by the application of an electrical potential between the column electrode 30 or gate electrode 30 and the row electrode 24 causing field emission of electrons 36 from the micro-tipped cathode 26 to the phosphor layer 18 . The electrical potential is typically a DC voltage of between about 30 and 110 volts. The transparent conductive anode layer 16 may also be biased (1-2 kV) to strengthen the electron field emission and to gather the emitted electrons toward the phosphor layer 18 . The electrons 36 bombarding the phosphor layer 18 excite individual phosphors 38 , resulting in visible light seen through the glass substrate 14 .
The micro-tipped cathodes 26 of FED device 10 are three-dimensional structures which may be formed as evaporated metal cones or etched silicon tips. Micro-tipped cathodes 26 provide enhanced electric field strength by about a factor of four or five over the two-dimensional structure of the two-dimensional alternative FED device 40 (see FIG. 2 ). However, the two-dimensional structure of the alternative FED device 40 can be formed with planar films and photolithography.
Referring to FIG. 2 , a portion of an alternative FED device 40 is shown in accordance with conventional flat cathode structure. FED device 40 includes a faceplate 42 and a baseplate 50 separated by spacers (not shown for clarity). The faceplate 42 may include a glass substrate 44 , a transparent conductive anode layer 46 disposed over the glass substrate 44 , and a phosphor layer 48 disposed over transparent conductive anode layer 46 . An electrical potential of between about one kilovolts to about two kilovolts may be applied to the transparent conductive anode layer 46 to enhance field emission of electrons and to gather emitted electrons at the phosphor layer 48 .
The baseplate 50 may include a substrate 52 , a conductive layer 54 , a flat cathode emitter 56 , a dielectric layer 58 and a grid electrode 60 . The conductive layer 54 may be a row electrode 54 and is deposited on the substrate 52 . The flat cathode emitter 56 and dielectric layer 58 are deposited on the conductive layer 54 . The grid electrode 60 may also be referred to as the column electrode 60 . The grid electrode 60 is deposited over, and supported by, the dielectric layer 58 . The flat cathode emitter 56 may comprise a low effective work function material such as amorphic diamond.
Several techniques have been proposed to control the brightness and gray scale range of FED devices. For example, U.S. Pat. No. 5,103,144 to Dunham, U.S. Pat. No. 5,656,892 to Zimlich et al. and U.S. Pat. No. 5,856,812 to Hush et al., incorporated herein by reference, teach methods for controlling the brightness and luminance of flat panel displays. However, even using these brightness control techniques, it is still very difficult to obtain a uniform electron beam from an FED emitter. Thus, there remains a need for methods and apparatuses for controlling FED beam uniformity.
BRIEF SUMMARY OF THE INVENTION
The present invention includes a field emitter circuit including a row electrode, at least one cathode structure on the row electrode, a grid electrode proximate to the at least one cathode structure and an electron beam uniformity circuit coupled to the grid electrode for providing a grid voltage sufficient to induce electron emission from the at least one cathode structure and with a periodically varying signal to provide electron beam uniformity.
A field emission display (FED) embodiment of the invention includes a faceplate, a baseplate and a circuit for controlling electron beam uniformity. The faceplate of this embodiment may include a transparent screen, a cathodoluminescent layer and a transparent conductive anode layer disposed between the transparent screen and the cathodoluminescent layer. The baseplate of this embodiment may include an insulating substrate, a row electrode disposed on the insulating substrate, a cathode structure disposed on the row electrode, an insulating layer disposed around the cathode structure and on the row electrode, and a column electrode disposed upon the insulating layer and proximate to the cathode structure. The cathode structure of this embodiment may be micro-tipped. In another embodiment, the cathode structure may be flat. The circuit for controlling electron beam uniformity provides a grid voltage including a periodic signal superimposed on a DC offset voltage. The DC offset voltage is sufficient to induce field emission of electrons from the cathode structure. The superimposed periodic signal provides electron beam uniformity.
An alternative embodiment of the present invention is a field emission display monitor including a video driver circuitry, a video monitor chassis for housing, and coupling to, the video driver circuitry and a field emission display coupled to the video driver circuitry and housed essentially within the monitor chassis. The field emission display may also include user controls coupled to the monitor chassis and in communication with the video driver circuitry. The field emission display includes an electron beam uniformity circuit.
A computer system embodiment of this invention includes an input device, an output device, a processor device coupled to the input device and the output device, and an FED coupled to the processor device.
The method according to this invention includes providing an FED device as described herein and varying the grid voltage with a periodic signal superimposed upon a DC offset voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, which illustrate what is currently regarded as the best mode for carrying out the invention and in which like reference numerals refer to like parts in different views or embodiments:
FIG. 1 illustrates a portion of a structural cross-section of an array of micro-tipped cathode emitters in a conventional field emission display (FED) device;
FIG. 2 illustrates a portion of a structural cross-section of an array of flat cathode emitters in an alternative conventional FED device;
FIG. 3 is a schematic of a single emitter and FED in accordance with this invention;
FIG. 4 illustrates a portion of a structural cross-section of an array of micro-tipped cathode emitters in accordance with this invention;
FIG. 5 illustrates a portion of a structural cross-section of an array of flat cathode emitters in accordance with this invention;
FIG. 6 is a block diagram of a video monitor including an FED in accordance with this invention; and
FIG. 7 is a block diagram of a computer system including an FED in accordance with this invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 3 , an emitter circuit 102 , in accordance with this invention, is shown schematically as part of an FED 100 . The emitter circuit 102 includes a cathode 104 with a row electrode 106 coupled to a switching element 108 . The switching element 108 is driven by row driver circuitry 110 . The emitter circuit 102 further includes a grid electrode 112 coupled to an electron beam uniformity circuit 114 . The terms “grid electrode” and “column electrode” may be used interchangeably. The grid electrode 112 is shown in proximity to the cathode 104 . Cathode 104 may be a micro-tipped cathode 26 as illustrated in FIG. 1 . Alternatively, cathode 104 may be a flat cathode emitter 56 as illustrated in FIG. 2 . The emitter circuit 102 may further include a switching element in series between the cathode 104 and the row electrode 106 . The emitter circuit 102 additionally may further include a resistive element, R, in series between the switching element 108 and a ground potential, GND. The row driver circuitry 110 may include current and brightness control circuitry as described in U.S. Pat. No. 5,856,812 to Hush et al., U.S. Pat. No. 5,103,144 to Dunham and U.S. Pat. No. 5,656,892 to Zimlich et al.
The electron beam uniformity circuit 114 provides a grid voltage, V Gid . The grid voltage, V Grid , in conventional FED devices is typically a DC voltage of between about 30 volts and 110 volts relative to ground potential, GND. The grid voltage, V Grid , of the present invention provides a periodic signal superimposed on a DC offset of between about 30 and 110 volts. The periodic signal is chosen with an operating frequency faster than detectable by the human eye. In what is currently considered to be the best mode of the invention, a frequency of about 50 Hertz or greater is sufficient to be undetectable by the human eye. The periodic signal may be sinusoidal, with peak-to-peak voltage excursions of between about 5 volts and 50 volts. Alternatively, the periodic signal may be a rectangular wave also with peak-to-peak variations of between about 5 volts and 50 volts. The duty cycle of the rectangular wave may be between about 10 percent and 90 percent. The circuitry comprising the electron beam uniformity circuit 114 for generating the grid voltage as described above is within the knowledge of one skilled in the art and thus, will not be further detailed.
FIG. 3 also schematically illustrates an FED 100 embodiment of the invention. FED 100 includes an emitter circuit 102 as described above and a faceplate 118 . The faceplate 118 may include a transparent screen or glass substrate layer (not shown for clarity), a transparent conductive anode layer 122 (hereinafter “anode 122 ”) and a cathodoluminescent layer or phosphor layer 124 . An electrical potential of between about 500 volts to about 5000 volts may be applied to the transparent conductive anode layer 122 to enhance the field emission of electrons and gather the emitted electrons at the phosphor layer 124 .
In operation, with switching devices 108 and 116 both on, the row electrode 106 is pulled to ground potential, GND, through resistor, R. The electrical potential, V Grid , between the cathode 104 (row electrode 106 ) and the grid electrode 112 is sufficient to cause electron emission from the cathode 104 . The emitted electrons may then be swept to the phosphor layer 124 causing illumination at the faceplate 118 .
Referring to FIG. 4 , a portion of an FED device 410 produced in accordance with this invention including micro-tipped cathode structures. The FED device 410 includes a faceplate 12 and a baseplate 20 , separated by spacers 32 . The spacers 32 support the FED device 410 structurally when the region 34 in between the faceplate 12 and the baseplate 20 is evacuated. The faceplate 12 includes a glass substrate 14 , a transparent conductive anode layer 16 and a cathodoluminescent layer or phosphor layer 18 . The phosphor layer 18 may include any known phosphor material capable of emitting photons in response to bombardment by electrons.
The baseplate 20 includes a substrate 22 with a row electrode 24 , a plurality of micro-tipped cathodes 26 , a dielectric layer 28 and a column electrode 30 , also referred to as a gate electrode 30 . The baseplate 20 is formed by depositing the row electrode 24 on the substrate 22 . The row electrode 24 is electrically connected to a row of micro-tipped cathodes 26 . The dielectric layer 28 is deposited upon the row electrode 24 . A column electrode 30 is deposited upon the dielectric layer 28 and acts as a gate electrode for the operation of the FED device 410 .
The substrate 22 may be comprised of glass. The micro-tipped cathodes 26 may be formed of a metal such as molybdenum, or a semiconductor material such as silicon, or a combination of molybdenum and silicon. Micro-tipped cathodes 26 may also be formed with a conductive metal layer (not shown) formed thereon. The conductive metal layer may be comprised of any well-known low work function material.
The FED device 410 operates by the application of an electrical potential between the column electrode 30 and the row electrode 24 causing field emission of electrons 36 from the micro-tipped cathode 26 to the phosphor layer 18 . Electron beam uniformity circuit 114 provides a grid voltage, V Grid , sufficient to emit electrons from the micro-tipped cathodes 26 with improved electron beam uniformity over prior art devices. The output of the electron beam uniformity circuit 114 , V Grid , of the present invention provides a periodic signal superimposed on a DC voltage offset of between about 30 and 110 volts. The periodic signal is chosen with an operating frequency faster than detectable by the human eye. In what is currently considered to be the best mode of the invention, a frequency of about 50 Hertz or greater is sufficient to be undetectable by the human eye. The periodic signal may be sinusoidal, with peak-to-peak voltage excursions of between about 5 volts and 50 volts. Alternatively, the periodic signal may be a rectangular wave also with peak-to-peak variations of between about 5 volts and 50 volts. The duty cycle of the rectangular wave may be between about 10 percent and 90 percent. The circuitry comprising the electron beam uniformity circuit 114 for generating the grid voltage as described above is within the knowledge of one skilled in the art and thus, will not be further detailed.
Transparent conductive anode layer 16 may also be biased to between about 500 volts to about 5000 volts to strengthen the electron field emission. The electrons 36 bombarding the phosphor layer 18 , illuminate individual phosphors 38 , resulting in visible light seen through the glass substrate 14 . The micro-tipped cathodes 26 of FED device 410 are three-dimensional structures which may be formed as evaporated metal cones or etched silicon tips.
Referring to FIG. 5. a portion of an alternative FED device 540 is shown in accordance with this invention including flat cathode structures. FED device 540 includes a faceplate 42 and a baseplate 50 separated by spacers (not shown for clarity). The faceplate 42 may include a glass substrate 44 , a transparent conductive anode layer 46 disposed over the glass substrate 44 , and a phosphor layer 48 disposed over transparent conductive anode layer 46 . An electrical potential of between about 500 volts to about 5000 volts may be applied to the transparent conductive anode layer 46 to enhance the field emission of electrons and gather the emitted electrons at the phosphor layer 48 .
The baseplate 50 may include a substrate 52 , a conductive layer 54 , a flat cathode emitter 56 , a dielectric layer 58 and a grid electrode 60 . The conductive layer 54 may be a row electrode 54 and is deposited on the substrate 52 . The flat cathode emitter 56 and dielectric layer 58 are deposited on the conductive layer 54 . The grid electrode 60 may also be referred to as the column electrode 60 . The grid electrode 60 is deposited over, and supported by, the dielectric layer 58 . The flat cathode emitter 56 may comprise a low effective work function material such as amorphic diamond.
FIG. 6 is a block diagram of a video monitor 600 in accordance with this invention. The video monitor includes an FED 610 coupled 615 to video driver circuitry 620 which is coupled 625 to user controls 630 . The FED 610 includes an electron beam uniformity circuit 114 as described herein. The video driver circuitry 620 interfaces 640 with a video controller (not shown). The components of the video monitor 600 are housed in a video monitor chassis 650 . Details of how to make and use video driver circuitry 620 , user controls 630 and video monitor chassis 650 are within the knowledge of one skilled in the art and thus, will not be further detailed herein.
FIG. 7 illustrates a block diagram of a computer system 90 including an FED 80 in accordance with this invention. The computer system 90 includes an input device 70 , an output device 72 , an FED 80 and a processor device 74 coupled to the input device 70 , the output device 72 and the FED 80 . The FED 80 includes an electron beam uniformity circuit 114 as described herein.
Although this invention has been described with reference to particular embodiments, the invention is not limited to these described embodiments. Rather, it should be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of the invention as defined in the appended claims. | The invention includes field emitters, field emission displays (FEDs), monitors, computer systems and methods employing the same for providing uniform electron beams from cathodes of FED devices. The apparatuses each include electron beam uniformity circuitry. The electron beam uniformity circuit provides a grid voltage, V Grid , with a DC offset voltage sufficient to induce field emission from a cathode and a periodic signal superimposed on the DC offset voltage for varying the grid voltage at a frequency fast enough to be undetectable by the human eye. The cathodes may be of the micro-tipped or flat variety. The periodic signal may be sinusoidal with peak-to-peak voltage of between about 5 volts and about 50 volts. | 7 |
FIELD OF THE INVENTION
The invention relates to the sphere of production of heavy crudes which notably have the drawback of too high a viscosity. The object of the method according to the invention is to reduce the pressure drop during heavy crude pipeline transportation by acting on the viscosity thereof.
Heavy oils are defined as crude oils whose API gravity is below 20. These oils, the world reserves of which are of the same order as for all the conventional oils, are characterized by a high asphaltene content and by a high viscosity that can reach up to a million centipoise at reservoir temperature. Their transportation by pipeline is therefore much more difficult than in the case of conventional crudes. Heavy crude pipeline transportation implies that the viscosity is sufficiently low considering the dimension of the transportation lines and the power of the pumping installations, selected in accordance with the economic optimum.
BACKGROUND OF THE INVENTION
There are various methods known to the man skilled in the art that allow heavy oil pipeline transportation. These methods are, for example, heating, dilution, aqueous emulsification, core annular flow, or partial crude refining on the production site before transportation.
Heating is an effective way of reducing notably the viscosity of heavy oils. However, depending on the characteristics of the crude to be transported, it may be necessary to bring the fluid to relatively high temperatures, sometimes above 100° C., to obtain a viscosity compatible with industrial plants. Furthermore, it is important to maintain the temperature of the fluid at this level all along the line, which implies thermal insulation of the lines and sometimes installation of heating units combined with the pumping installations.
Emulsification of crude in water is also used. In this technique, the crude is transported in form of fine droplets in a continuous phase mainly consisting of water. In order to guarantee emulsion stability all along the pipeline, it is necessary to add judiciously selected surfactants to the water. These surfactants must also simultaneously allow, in a simple manner, inversion of the emulsion upon arrival at the refinery and recovery of the anhydrous crude, and treatment of the polluted water.
Core annular flow consists in transporting the crude surrounded by a water film. This is the most effective method for reducing pressure drops, which are almost comparable to those obtained with water. This technique is for example described in U.S. Pat. No. 4,753,261. However, this method involves difficulties linked with the flow stability, fouling of the pipeline walls in the course of time and notably restarting difficulties in case of non-programmed production stop, which is why this transportation mode has not been used much up to now.
Another method that can be considered for bringing the viscosity of a crude to a value compatible with pipeline transportation is partial refining on the production site. An example is given in U.S. Pat. No. 5,110,447. This method requires considerable investments and high operating costs due to the increase in the number of visbreaking units on the site.
In order to reduce the viscosity of heavy oils, they are commonly diluted by means of solvents. The solvents used are hydrocarbon cuts such as condensates or naphtha. This method is based on the fact that the viscosity of heavy crudes is greatly reduced when adding a solvent of low viscosity. It is generally admitted that, in order to obtain a sufficient viscosity reduction to allow pipeline transportation of a heavy oil, the amount of light solvent to be added ranges between 10 and 50% by volume. When this method is used, it most often comprises a second pipeline allowing to recycle the solvent after distillation separation at the refinery. This method can be regarded as the most effective for heavy crude transportation. Despite considerable investment, it allows oil to be transported without particular risks, even in case of prolonged production stop. Furthermore, diluting the crude facilitates certain operations such as separation of the production water. However, the volume to be transported is increased, and the cost of the solvent and of its possible separation from the crude in order to recycle it is not insignificant.
One possible improvement to the dilution of heavy crudes consists in improving the method so as to obtain the viscosity required for pipeline transportation using a lower volume of solvent.
SUMMARY OF THE INVENTION
The present invention thus relates to a method of optimizing heavy crude transportation wherein at least one solvent is added to the crude. According to the invention, a predetermined amount of dimethyl ether (DME) is added under pressure.
The addition pressure can be at least about 4 bars.
The solvent can comprise naphtha.
The DME can be recovered by means of at least one fluidified crude expansion stage.
The DME can be recovered by means of at least one fluidified crude distillation stage.
The proportion by mass of DME can range between 1 and 25% of the crude.
The proportion by mass of DME can range between 4 and 10% of the crude.
The object of the present invention is to improve the method of diluting a heavy crude. It has been shown that the addition under pressure of DME (dimethyl ether) leads to a notable crude viscosity decrease. If a first solvent is used, the addition under pressure of DME shows a change in the solubility parameters of the solvent used, in particular a notable improvement in the dilution efficiency of the solvent considered. Furthermore, recovery of the DME upstream from the refinery is greatly facilitated by the very nature of the DME.
DETAILED DESCRIPTION
The present invention thus relates to a method of diluting heavy crudes under pressure. It has been shown that well-chosen pressure and temperature conditions allow incorporation of dimethyl ether to the crude and/or to a solvent used. A dilution improvement is thus observed. The present invention in fact allows not only to increase the polarity of the diluent, but also to greatly decrease the inherent viscosity thereof.
The following examples illustrate the invention without however limiting it to these embodiments.
Example 1
A heavy Venezuelan crude of density 8.5 API degrees has a viscosity of 940 Pa·s at 15° C. and 5 bars.
This crude is diluted in the proportion of 22.5% by mass with naphtha. The viscosity of the crude is then 0.525 Pa·s at 15° C. and 5 bars.
Example 2
The previous crude oil is diluted with naphtha in the proportion of 11.5% by weight. Liquid DME (dimethyl ether) is then added at 5 bars and 15° C. until a viscosity of 0.525 Pa·s is obtained. The required DME mass is measured. The dilution percentage is then calculated, it corresponds to 15% by mass of diluents, with a DME/naphtha mass ratio of 0.36.
Example 3
The addition of liquid DME is continued at the end of Example 2 until a viscosity of 0.04 Pa·s is obtained at 15° C. and 5 bars. The DME mass required to obtain this value is measured. The calculated dilution percentage corresponds to 23.4% by mass with a DME/naphtha mass ratio of 1.4. By way of comparison, a crude oil mixture is diluted with naphtha in the proportion of 23.4% by mass, the viscosity obtained is 0.34 Pa·s at 15° C. and 5 bars. The efficiency of the addition under pressure of DME is clearly visible.
Example 4
A Canadian crude oil has a viscosity of 205 Pa·s at 15° C. and 5 bars. This crude is diluted in the proportion of 22.5% by mass with naphtha. The viscosity of the crude then becomes 0.23 Pa·s at 15° C. and 5 bars.
Example 5
The Canadian crude used in Example 4 is diluted with naphtha in the proportion of 11.5% by mass. Liquid DME (dimethyl ether) is then introduced at 5 bars and 15° C. until a viscosity of 0.23 Pa·s is obtained. The required DME mass is measured and the calculated dilution percentage corresponds to 19.8% by mass, with a DME/naphtha mass ratio of 0.2. By way of comparison, a crude oil mixture is diluted with naphtha in the proportion of 19.8% by mass, the viscosity obtained is 0.41 Pa·s at 15° C. and 5 bars.
The previous examples were completed by carrying out tests at a higher ambient temperature: 25° C.
Example 1a
A heavy Venezuelan crude of density 8.5 API degrees has a viscosity of 200 Pa·s at 25° C. and 4 bars.
This crude is diluted in the proportion of 22.5% by mass with naphtha. The viscosity of the crude is then 0.265 Pa·s at 25° C. and 4 bars.
Example 2a
The previous crude oil is diluted with naphtha in the proportion of 11.5%. DME (dimethyl ether) in gaseous form is then added at 4 bars and 25° C. until a viscosity of 0.265 Pa·s is obtained. The required DME mass is measured. The dilution percentage is then calculated, it corresponds to 17% by mass, with a DME/naphtha mass ratio of 0.4.
Example 4a
A Canadian crude oil has a viscosity of 30 Pa·s at 25° C. and 4 bars. This crude is diluted in the proportion of 22.5% by mass with naphtha. The viscosity of the crude then becomes 0.168 Pa·s at 25° C. and 4 bars.
Example 5a
The aforementioned Canadian crude is diluted with naphtha in the proportion of 11.5%. Gaseous DME (dimethyl ether) is then introduced at 4 bars and 25° C. until a viscosity of 0.168 Pa·s is obtained. The required DME mass is measured. The calculated dilution percentage corresponds to 17% by mass, with a DME/naphtha mass ratio of 0.4.
The examples above clearly show the efficiency of DME used as the thinning agent for a crude coming directly from a production well, or first diluted with naphtha for example. The amounts of DME injected under pressure are determined according to the nature of the fluid to be fluidified, notably its initial viscosity, and the desired final viscosity for a given production situation.
The diluted crude having been transported to the inlet of the refining plant, the first stage comprises means, distillation means for example, for collecting the solvents, in particular the DME. A simple expansion allows the DME to be vaporized and recovered in gaseous form. This operational stage provides the whole process with a great economic advantage.
Dilution of the heavy crude can be carried out at the bottom of the production well, downstream from the wellhead at the surface, or in an intermediate transportation line. | Heavy crude transportation optimization method wherein at least one solvent is added to said crude. According to the method, a predetermined amount of dimethyl ether (DME) is added under pressure so as to adjust the viscosity of the crude. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to an insulator surface layer such as an oxide and a fluoride. The present invention further relates to solid state electronic devices having insulators.
A solid state electronic circuit such as a semiconductor integrated circuit is constructed of semiconductor material, metal, insulators, and other materials, which are processed into fine patterns and are stacked.
Insulators are often composed of a silicon oxide thin film or a thin film of amorphous structure containing boric acid, phosphorous and other elements, with silicon oxide as its main component. These thin films are usually formed as layers on a substrate (including directly on other layers that are on the substrate) by silicon thermal oxidation or chemical vapor deposition (CVD), plasma CVD, and sputtering deposition.
For example, an insulating film used for an insulator between metal wirings of a semiconductor integrated circuit often has a film of SiO 2 as its main component, which is formed by the CVD using a gas such as SiH 4 and N 2 or plasma CVD. The insulator film may be approximately 1 μm thick. Then, usually, subsequent to the formation of wiring via-holes, and other patterns by the lithographic process and etching process, the next layer which is a metal layer for wirings is stacked by the CVD method, sputtering deposition or the like, and through subsequent lithographic and etching processes, fine metal wirings are formed. In the stacked structure of a semiconductor integrated circuit formed in such a series of processes, rarely it has been attempted to improve intentionally the modification of the film quality of the surface insulator film layer or interlayer insulator film. The insulator film as deposited is used as it is.
Also, a silicon oxide thin film of 10-20 nm thick and mostly formed by thermal oxidation is used for the gate insulator film for the silicon MOS type transistor. In this case, too, the thin film is used as it has been deposited without any particular improving modification treatment for improving the property of the silicon oxide film significantly with the exception of the simple treatment of annealing.
As another example, there is a capacitor insulator film for a memory device of the memory integrated circuit and others, and in recent years, in order to intensify the electrostatic capacity thereof, the silicon oxide film is used in layers with the silicon nitride film having a large dielectric constant.
For the insulator film of a semiconductor integrated circuit as described above, the insulator film deposited by thermal oxidation, CVD or the like is used as it is without any particular surface treatment before the present invention.
A technique for forming an insulator film for a semiconductor integrated circuit is explained in detail in S. M. Sze ed, VLSI Technology, Second Edition (McGraw-Hill, New York, 1988) pp. 98-140 and 233-271, for example.
In the above-mentioned conventional technique, insulator films of SiO 2 and others are used as formed by thermal oxidation or CVD. In the case of the thermal oxidation formed SiO 2 film, its density is usually approximately 2.2-2.3 g/cm 3 , for example, and it is known that such SiO 2 film is susceptible to transmission of molecules of H 2 O, O 2 H 2 and others and atoms dissociated therefrom, which often leads to a problem that the oxidation, corrosion, and other degradations of the metal wirings are caused by the water and other molecules thus transmitted. In contrast, a SiO 2 film formed by plasma CVD is in general high in its density and is highly capable of preventing the transmission of water and other molecules. However, in the plasma CVD formed film, a considerable value of H is contained to often result in the film expansion, cracking, and production of other defectives due to the dissociation of the contained H at the time of thermal treatment.
Also, the relative dielectric constant of the SiO 2 film formed by silicon thermal oxidation and others is 3.9-4.0, and since this value is insufficient, a multi-layer film, in which the Si 3 N 4 film or Ta 2 O 5 film having a greater dielectric constant is stacked with the SiO 2 film, is used as an insulator film for the charge storage capacitor of the random access memory device. The dielectric constant of the SiO 2 film is small, and the capacity of the capacitor is also small when made by the SiO 2 film alone.
Further, the SiO 2 film is formed by thermal oxidation or CVD is easily etched by rare fluorine acid or its surface is reduced by the irradiation of H or rare gas ions, and tends to be Si rich.
SUMMARY OF THE INVENTION
An object of the present invention is to substantially improve the characteristics of oxides and other insulators formed by the conventional techniques set forth above for any of the above usages, particularly to improve its density, relative dielectric constant, resistance to acid, resistance to reduction and other characteristics, and to provide solid state devices or solid state materials such as those mentioned above having the characteristics improved by the present invention.
In order to achieve the above-mentioned object, the present invention irradiates onto the surfaces of the silicon oxide insulator, or the like, electrically neutral particles. With the irradiation of electrically neutral particles, it is possible to improve material properties, such as the density of the surface layer, chemical bond of surface atoms, dielectric properties and resistance to acid of the silicon oxide and other insulator compounds without modifying its surface chemical composition significantly. To this end, it is most desirable for the electrically neutral particles to possess a kinetic energy of several eV or more. Usually, a neutral beam of approximately 50 -1,000 eV should be used depending upon the chosen neutral atom. To generate such a neutral beam, the simplest and most effective system is to extract the ion beam having a desired energy from plasma, and using an apparatus such as shown in FIG. 5, the extracted beam is converted into the neutral beam by a charge exchange reaction. The charge exchange reaction is the electron transfer reaction between the particles, and the ion neutralization results from the electron transfer between ions and neutral atoms or neutral molecules. Therefore, when the ion beam passes through a neutral gas, the neutral beam is generated by this reaction, and it is possible to obtain only the neutral beam by removing the charged particles such as residual ions in a magnetic field or in an electrostatic field.
Usually, as the neutral particle beam, oxygen, nitrogen, silicon and other elements constituting the insulator film may be used besides rare gases, such as neon, argon and krypton.
In order to use the insulator film in a solid state device, it is usually important to provide a heating treatment at 100° C. or more after the irradiation by the neutral beam or during the irradiation for forming a film that is microscopically even.
It is not necessary to limit the incident direction of the neutral particle beam irradiated onto the surface to one direction. The irradiation can be performed at various angles of incidence.
Particularly, when there is an irregularity on the surface of the irradiated substrate, it is necessary to arrange the incidence in various directions for obtaining an overall improving modification of the entire film effectively. For this purpose, it is effective to use an irradiating system having a plurality of neutral beam sources with the beam directions different from each other or to allow the specimen to be rotated or vibrated in the course of the irradiation.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects, features and advantages of the present invention will become more clear upon the following detailed description of preferred embodiments as shown in the drawing, wherein:
FIG. 1 is a view showing the present invention applied to modifying the surface of the interlayer insulator film for a semiconductor integrated circuit;
FIG. 2 is a view useful for explaining the present invention and illustrating the generation of granular metals on the silicon oxide film surface in chemical vapor deposition in the case where no surface modification treatment of the present invention is performed;
FIG. 3 is a cross-sectional view showing the structure of a semiconductor device having the gate insulator film according to the present invention;
FIG. 4 is a cross-sectional view showing the structure of a semiconductor device having the capacitor insulator film modified according to the present invention;
FIG. 5 is a schematic view showing a neutral beam irradiation apparatus used for the surface treatment method according to the present invention;
FIG. 6 is a schematic view showing another type of the neutral beam irradiation apparatus used for the surface treatment method according to the present invention;
FIG. 7 is a view showing the thin film stacking apparatus in which an apparatus for performing a preparatory treatment of the neutral beam irradiation is added;
FIG. 8 is a view showing Auger spectra when the thermal oxidation film (SiO 2 ) on a silicon substrate is being sputter etched 1 nm by the ion beam.
FIG. 9 is a view showing Auger spectra when a specimen of the above-mentioned thermal oxidation film, which is irradiated by the neutral beam of Ne, is being sputter etched by ion beams.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The improvement of the film quality of the insulator film by the irradiation of the neutral beam set forth above has been discovered by the inventors. Hereinafter, experimental results will be described.
FIG. 8 is a view showing the spectra of Auger electron spectroscopy (AES) analysis on a thermal oxide film (SiO 2 ) formed on a silicon (Si) substrate. As shown in FIG. 8, the Auger electron spectra corresponding to the Si in the SiO 2 are observed at 56, 62 and 78 eV. To this specimen, an Ar + ion beam of 3 KeV is irradiated, and the initial SiO 2 film of curve A was sputter etched in increments of depth of 1 nm to collect the Auger spectra of its surface sequentially for curves B, C, D, E that respectively represent an etching of 1 nm, 2 nm, 3 nm, 4 nm. From the results shown in FIG. 8, it is seen that new spectra appear at 82 eV and 89 eV in addition to the above-mentioned three spectra at 56 eV, 62 eV, and 78 eV, and the intensities of the new spectra at 82 eV and 89 eV become greater little by little from curve B through curve E. These new spectra at 82 eV and 89 eV appear because the suboxide SiOx (x<2) or the elemental Si which has been reduced completely is generated as a result of the reduction of the SiO 2 surface by the Ar + ion irradiation as described in Lang in Applied Surface Science, Vol. 37 (1989) pp. 63-77, and the Auger spectra at 82 eV and 89 eV correspond respectively to the SiOx and Si. SiO 2 no longer exists in the topmost surface layer; the spectra 56, 62, 78 are obtained from a greater depth.
However, it has been found by the inventors hereof that if the neutral beam of Ne is irradiated onto the SiO 2 surface in advance, the above-mentioned reduction reaction does not advance easily.
FIG. 9 is a view showing the Auger spectra of a substrate that is identical to the substrate of FIG. 8, except that the SiO 2 surface is irradiated by a neutral beam of Ne at 500 eV in an irradiation dosage of approximately 10 17 /cm 2 according to the present invention. Curves G-K represent Ar + ion beam etching depths of 1 nm, 2 nm, 3 nm, 4 nm and 12 nm, respectively. As shown in FIG. 9, the 82 eV and 89 eV spectra corresponding to the SiOx and Si do not appear when the etching is performed with the irradiation of the Ar + ion beam at 3 KeV. When the etching depth reaches 12 nm, the spectra in the vicinity of 80 eV expands at last. This appears to indicate that the SiOx (x<2) of 82 eV has appeared.
On the other hand, when the SiO 2 surface is irradiated, without the present invention, by the Ne + ion beam in 10 17 /cm 2 at 500 eV for the Auger analysis, the SiOx and Si Auger spectra appear immediately as in the case of the standard specimen shown in FIG. 8.
As the above shows, the SiO 2 surface layer has been modified in quality to have a more intensified resistance to reduction by the ion irradiation, as a result of the neutral beam irradiation according to the present invention.
The microscopic structure of such quality modification has not been clear as yet, but this modification is conjectured to be as given below.
When a particle having a kinetic energy of several 10 to several 100 eV collides against the solid state surface of the substrate, very high pressure occurs in the vicinity of the point of collision in an extremely short period of time, and at the same time, or with a slight time lag, a high-temperature state occurs, thus the modification of the solid state structure is implemented.
It is known that if silicon oxide is placed in a state of very high pressure of approximately 100K bar or more, the silicon oxide is densified, and it is known that such modification is irreversible often with phase transition accompanying the densification; under a very high pressure at a high temperature, the silicon oxide shifts to a phase having a high density and a high index of refraction such as coesite or stishovite. With the neutral irradiation of the present invention, there is a possibility that microscopically a similar phenomenon is taking place, and it is conjectured that the surface layer of the silicon oxide film has been densified.
Although the same densifying effect is probably obtainable with a known ion beam, as distinguished from the neutral beam of the present invention, it is not desirable to use the ion beam because the surface chemical composition changes significantly from the bulk composition due to the known fact that oxygen or halogen is released preferably from the surface layer when the charged particle of the ion beam is irradiated onto the oxide or halogenide, i.e., the known phenomenon of the so-called preferential sputtering for example is explained relative to FIG. 8. In the case of the neutral beam irradiation, such change in the composition rarely takes place as has been found by the inventors hereof according to their experiments and as shown in FIG. 9, and therefore the above-mentioned modification of the film quality is possible. Further, since an ion beam is charged, there is a disadvantage that if the specimen is an insulator film which is as thin as silicon oxide film, the degradation in breakdown field or insulator breakdown occurs.
Also, the use of a beam particle having a large atomic radius such as krypton and xenon is effective to improve the film quality evenly and more deeply. When the neutral beam of rare gas is irradiated, its energy should desirably be 100 eV or less because if it is more than several 100 eV, the rare gas is trapped in the film to spoil the evenness of the film. In order to promote the diffusion and emission to the outside of the surface, it is effective to heat the substrate surface to 100° C. or more during the irradiation.
In the case of the silicon oxide film irradiated by the neutral beam taken as an example, the refractive index of the surface layer of 5-10 nm depth of the silicon oxide film formed by the present invention is increased to 1.6-3.5 depending on the irradiation conditions, according to the measurements by an ellipsometer, and the results are found to be significantly high as compared with the refractive index of 1.46 for the silicon dioxide by usual thermal oxidation of silicon. Also, this silicon oxide film formed by the improving modification is high inits resistance to acid such as dilute hydrofluoric acid, and there have been some examples observed in which the etching rate is reduced by 1/2-1/3. Furthermore, the dielectric constant is increased by 1.5-2 times that of the usual thermal oxidation film.
If the silicon oxide film having the characteristics set forth above is used as an insulator film between the wiring layers of a semiconductor integrated circuit, there has been observed a significant effect to prevent the selective deposition on this surface when a thin film of another material is deposited by CVD and other types of deposition, because the chemical stability of the surface is high.
Hereinafter, the embodiments of the present invention will be described in detail.
Embodiment 1
With reference to FIG. 1 and FIG. 2, the first embodiment is described. Although a film with the silicon oxide deposited by chemical vapor deposition (CVD) as its main component is used as the interlayer insulator film 3 in the multilayer wiring for a semiconductor integrated circuit, the processes given below are used for the connection between wirings for an integrated circuit of a very large scale integration, VLSI. At first, a fine via hole 6 is opened in the interlayer insulator film 3 by dry etching to expose the wiring surface of the lower metal layer 2, which is on a substrate 1. Since this via hole 6 is deep in general, hole filling metal 5 such as tungsten is first deposited by selective CVD to fill in only the fine via hole 6. At this juncture, it is utterly undesirable to deposit even a small quantity of tungsten metal on the remaining surface of the silicon oxide 3. Nevertheless, as shown in FIG. 2, an undesirable particle or granular tungsten 7 is often grown on the silicon oxide surface 8 of the interlayer insulator film 3 at the time of filling the via hole 6, to cause the yield of the subsequent wiring to be adversely affected. One of the reasons why this occurs is that the surface of the silicon oxide interlayer insulator film 3 is not sufficiently resistive to CVD gas such as tungsten fluoride or hydrogen, and the silicon oxide surface is locally reduced thereby to be the nucleus of the deposition of the granular tungsten 7.
Therefore, for the purpose of applying the neutral beam of the present invention, an apparatus which generates a neutral beam of rare gas of several 10 eV to several 100 eV as a preparatory processing is added to the operation before the usual CVD apparatus 74 as shown in FIG. 7. Prior to the CVD of filling metal 5, an Ar neutral beam of 300 eV is irradiated onto the surface of the silicon oxide interlayer insulator 3 in the dosage of approximately 10 17 /cm 2 to form the surface modified layer 4. Subsequently, the selective deposition of tungsten filling metal 5 to the fine hole 6 is performed by CVD. As a result, the growth of the granular tungsten 7 is substantially controlled, i.e., prevented. The same effect is conspicuously observed in the case of irradiation by a neutral beam of other rare gases, such as Ne and Kr. Conceivably, these are the results of the enhancement of the chemical stability and resistivity to reduction of the modified surface layer 4 of the silicon oxide interlayer insulator film 3 by the irradiation of the neutral beam.
Also, by the above-mentioned neutral beam irradiation, the bottom of the fine hole 6 is cleaned. As a result, improvement of the contact condition between the hole filling metal 5 and the lower layer metal wiring 2 is effectively implemented at the same time.
Embodiment 2
FIG. 3 is a cross-sectional view illustrating the structure of an electronic solid state device. When the silicon oxide gate insulator film 31 for a silicon MOS type transistor is formed under an oxygen atmosphere of approximately 10 -3 Torr, it is possible to improve the resistivity to an insulator breakdown field by 1.5-2 times that of the usual thermal oxidation film (39 of FIG. 4) by surface irradiation with a neutral beam of oxygen at the same time of or subsequent to the formation of silicon oxide gate insulator film 31. By the present invention, a device is produced with the gate insulator oxide film 31 that rarely causes breakdown due to charges. Thereafter, to complete the construction of the silicon MOS type transistor, after formation of the gate insulator film 31, the following structure is added. On top of the silicon oxide gate insulator film 31 after it has been provided with the modified surface layer according to the present invention, an insulator film 32 is formed and then covered with an insulator film 33. Thereafter, a polycrystalline film 34 is formed, covered by a capacitor insulator film 35, which is in turn covered by a polycrystalline silicon film 36. An electrode via hole 37 is formed to provide interlayer wiring, and the MOS device is then completed by providing such wiring and other conventional structure. The usual SiO 2 layer 38 is also provided.
Embodiment 3
The spin-on-glass film (SOG film) that is used as an insulator film between wiring layers of a semiconductor integrated circuit is low in density and porous. Therefore, the SOG film is high in its water transmissivity and absorption ability. Onto the surface of this SOG film surface, the Ar neutral beam of 300 eV-400 eV is irradiated in a dosage of 5×10 16 /cm 2 by the present invention to improve the density of the SOG film surface layer. As a result, it is possible to reduce defects such as the expansion of the interlayer film which could conceivably result from absorbed water and other materials.
Embodiment 4
FIG. 4 is a cross-sectional view showing the structure of a silicon MOS type transistor and memory capacitor unit of the type described with respect to FIG. 3. The capacitor insulator film 40 for the memory capacitor unit of this device is formed as described below. Subsequent to the formation of the polycrystalline silicon film 34 corresponding to one of the capacitor electrodes, the silicon oxide capacitor insulator film 35 of approximately 8 nm thick is formed by oxidizing the surface of the polycrystalline silicon film 34 in dry oxygen. Subsequently, by the use of an apparatus shown in FIG. 5, a neutral beam of Kr having an energy of approximately 100 eV is irradiated in the dosage of approximately 10 16 /cm 2 . With this process, the surface layer 40 of the silicon oxide film 35 is densified to the modified state of a high dielectric constant. Subsequent to this, the polycrystalline silicon layer 36, which is the other electrode of the capacitor, is formed to construct the memory capacitor. The capacitance of the capacitor thus formed in accordance with the above-mentioned sequence of processes is increased by 1.5-2.0 times as compared with the capacitor of FIG. 3 that has not been treated by the neutral beam process of the present invention.
As shown in FIG. 5, a waveguide 51 for guiding microwave energy has plasma generated in a discharge tube 52 within the waveguide 51, which discharge tube 52 is surrounded by solenoid 53. Inlet tube 54 provides gas to the interior of the housing that provides a vacuum chamber for the substrate 57 upon which the modification of the present invention is performed. Electrical energy is provided to extraction electrodes 55, and thereby an ion beam of the gas is generated through the extraction electrodes 55 from the plasma generated with the microwave energy and the action of the solenoid coil. Charged particles are expelled by the grid 56 so that only the neutral beam is irradiated onto the substrate 57 while the chamber is evacuated by the vacuum pump 58.
In FIG. 6 there is shown a different apparatus for providing the neutral beam in performing the improved surface modification according to the present invention. Through an aperture 61, there is passed the gas to form the beam that is supplied from the gas supply inlet 62, and the first aperture 61 is formed between ion beam extraction electrodes provided with electrical energy to form an ion beam that travels through second apertures 63 to be directed toward the substrate 67. Charged particles or ions are removed by the deflection electrodes 64 that are provided with electrical energy as indicated so as to form the neutral beam 65; the charged particles or ions are deflected as ion beams 66 by the deflection electrodes 64 away from the substrate 67. Therefore, the substrate 67 is only irradiated with the neutral beam. As in the apparatus of FIG. 7, the vacuum pump 68 evacuates the chamber holding the substrate 67 during the irradiation with the neutral beam.
FIG. 7 contains much structure previously described. In addition, there is provided a substrate base 71 for holding the substrate during first neutral beam surface processing, a transporter 72 for transporting the substrate from the substrate base 71 through a joint 73 to a new base where the substrate 75 is contained within a chemical vapor deposition (CVD) apparatus 74. The housing 77 of the apparatus for neutral beam irradiation forms a vacuum chamber for the substrate on the substrate base 71 during irradiation, and a vacuum is pulled through the action of a vacuum pump 58. The joint 73 is also held at a vacuum by another vacuum pump 58, and the chemical vapor deposition apparatus 74 is held at a selected vacuum by still another vacuum pump 58. In this manner, the vacuums within housing 77 and chemical vapor deposition apparatus 74 may be held at different values according to the respective pumps 58 for simultaneously processing different substrates, and these two chambers are isolated from each other by appropriate valves separating them from the joint 73 that is held at a convenient selected vacuum by its own vacuum exhaust pump 58. Within the chemical vapor deposition apparatus, there is provided a gas supply inlet 54 and a heater 76.
In place of the apparatus shown in FIG. 5, a system called a McIlraith-type ion source shown in FIG. 6 may be employed. However, as the energy of the neutral beam generated by this later system is as great as 2 KeV or more, there is a disadvantage that the spoilage caused to the surface is great.
Embodiment 5
The preparatory neutral beam surface processing of this embodiment is conducted in the left-hand side of the thin film deposition apparatus of the present invention shown in FIG. 7 and described below.
Rare gas of Ar, Kr, or the like is induced from the gas inlet 54 and exhausted by a vacuum pump 58 to maintain the pressure in the vacuum chamber of housing 77 at 10 -4 -10 03 Torr. Microwave power is supplied through the waveguide 51 and magnetic field power is supplied by the coil 53 to generate plasma in the discharge tube 52. Then, an ion beam is generated through the extraction electrodes 55. By the function of the grid 56 to expel charged particles, only the neutral beam produced by the charge exchange reaction is irradiated onto the substrate mounted on the substrate base 71. The transporter for substrate transportation 72 transports the preparatorily neutral beam surface processed (irradiated) substrate to the chemical vapor deposition (CVD) apparatus 74 through the vacuum joint 73. Then, it is possible to deposit a thin film on the substrate 75 by CVD while heating the substrate to a desired temperature by the heater 76. Thereby the substrate surface is cleaned while undergoing the improved surface modification and transported under vacuum directly for CVD to minimize subsequent contamination.
According to the present invention, it is possible to enhance the density of the insulator film surface and control the refractive index, dielectric constant, and other characteristics by irradiating neutral particles onto the insulator film surface to effectively intensify the characteristics of its resistance to an insulator breakdown field, resistance to chemicals, resistance to acid, resistance to reduction, insulator characteristics and other characteristics. As a result, the reliability/life of a solid state device having these insulator films is improved.
In the descriptions set forth above, the improvement of the characteristics has been described in most cases for an insulator film having silicon oxide as its main component, but the present invention can be utilized effectively for the improving modification of the surface of a wide range of insulators such as aluminum oxide, silicon oxide and silicon oxide compound, and fluoride.
While a preferred embodiment has been set forth along with modifications and variations to show specific advantageous details of the present invention, further embodiments, modifications and variations are contemplated within the broader aspects of the present invention, all as set forth by the spirit and scope of the following claims. | To improve the characteristics of oxides and other insulators formed by conventional techniques, particularly to improve its density, relative dielectric constant, resistance to acid, resistance to reduction and other characteristics, and to provide solid state devices or socharacteristics, the surfaces of the silicon oxide insulator, or the like, is irradiated with electrically neutral particles. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 10/455,008 filed Jun. 5, 2003, which claims the benefit of U.S. Provisional Application Ser. No. 60/395,181 filed Jul. 10, 2002, both of which are hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to the field of abrasive tool inserts and, more particularly, to such inserts having a support with a central downwardly sloping profile and an outer steeper sloping profile, which reduces the surface axial residual stresses by 83% compared to a flat, planar interface and by 23% compared to a substrate with a single sloped rim. The reduction of the surface axial residual stress increases the impact performance and extends the working lifetime of the cutting tool.
[0003] Abrasive compacts are used extensively in cutting, milling, grinding, drilling and other abrasive operations. An abrasive particle compact is a polycrystalline mass of abrasive particles, such as diamond and/or cubic boron nitride (CBN), bonded together to form an integral, tough, high-strength mass. Such components can be bonded together in a particle-to-particle self-bonded relationship, by means of a bonding medium disposed between the particles, or by combinations thereof. The abrasive particle content of the abrasive compact is high and there is an extensive amount of direct particle-to-particle bonding. Abrasive compacts are made under elevated or high pressure and temperature (HP/HT) conditions at which the particles, diamond or CBN, are crystallographically stable. For example, see U.S. Pats. Nos. 3,136,615, 3,141,746, and 3,233,988.
[0004] A supported abrasive particle compact, herein termed a composite compact, is an abrasive particle compact, which is bonded to a substrate material, such as cemented tungsten carbide.
[0005] Abrasive compacts tend to be brittle and, in use, they frequently are supported by being bonded to a cemented carbide substrate. Such supported abrasive compacts are known in the art as composite abrasive compacts. Compacts of this type are described, for example, in U.S. Pats. Nos. 3,743,489, 3,745,623, and 3,767,371. The bond to the support can be formed either during or subsequent to the formation of the abrasive particle compact. Composite abrasive compacts may be used as such in the working surface of an abrasive tool.
[0006] Composite compacts have found special utility as cutting elements in drill bits. Drill bits for use in rock drilling, machining of wear resistant materials, and other operations which require high abrasion resistance or wear resistance generally consist of a plurality of polycrystalline abrasive cutting elements fixed in a holder. Particularly, U.S. Pats. Nos. 4,109,737 and 5,374,854, describe drill bits with a tungsten carbide stud (substrate) having a polycrystalline diamond compact on the outer surface of the cutting element. A plurality of these cutting elements then are mounted generally by interference fit into recesses into the crown of a drill bit, such as a rotary drill bit. These drill bits generally have means for providing water-cooling or other cooling fluids to the interface between the drill crown and the substance being drilled during drilling operations. Generally, the cutting element comprises an elongated pin of a metal carbide (stud) which may be either sintered or cemented carbide (such as tungsten carbide) with an abrasive particle compact (e.g., polycrystalline diamond) at one end of the pin for form a composite compact.
[0007] Fabrication of the composite compact typically is achieved by placing a cemented carbide substrate into the container of a press. A mixture of diamond grains or diamond grains and catalyst binder is placed atop the substrate and compressed under HP/HT conditions. In so doing, metal binder migrates from the substrate and “sweeps” through the diamond grains to promote a sintering of the diamond grains. As a result, the diamond grains become bonded to each other to form a diamond layer, which concomitantly is bonded to the substrate along a conventionally planar interface. Metal binder can remain disposed in the diamond layer within pores defined between the diamond grains.
[0008] A composite compact formed in the above-described manner may be subject to a number of shortcomings. For example, the coefficients of thermal expansion and elastic constants of cemented carbide and diamond are close, but not exactly the same. Thus, during heating or cooling of the polycrystalline diamond compact (PDC), thermally induced stresses occur at the interface between the diamond layer and the cemented carbide substrate, the magnitude of these stresses being dependent, for example, on the disparity in thermal expansion coefficients and elastic constants.
[0009] Another potential shortcoming, which should be considered, relates to the creation of internal stresses within the diamond layer, which can result in a fracturing of that layer. Such stresses also result from the presence of the cemented carbide substrate and are distributed according to the size, geometry, and physical properties of the cemented carbide substrate and the polycrystalline diamond layer.
[0010] Recently, various PDC structures have been proposed in which the diamond/carbide interface contains a number of non-planar features designed to increase the mechanical bond and reduce thermally induced residual stresses. For example, U.S. Pat. No. 5,351,772 presents various interface designs containing radial raised lands on the substrate. However, high tensile residual stresses still exist at the diamond surface and near the interface in those designs. U.S. Pat. No. 5,484,330 suggests a sawtooth shaped cross-sectional profile and U.S. Pat. No. 5,494,777 proposes an outward sloping profile in the interface design. U.S. Pat. No. 5,743,346 proposes an interface having an inner surface and an outer chamfer that forms a 5° to 85° angle to the vertical, wherein the inner surface is other than the chamfer. U.S. Pat. No. 5,486,137 also proposes a tool insert having an outer downwardly sloped interface surface. U.S. Pat. No. 6,949,477 proposes a tool insert having an outer downwardly sloping interface. U.S. Pat. No. 5,971,087 also proposes various dual and triple slope interface profiles.
[0011] However, these patents do not propose the incorporation of a sloped profile in the interior of the cutter. Such a sloped profile combined with a steeper slope on the outer edge of the cutter, further reduces the surface residual stresses. Accordingly, it would be highly desirable to provide a polycrystalline diamond compact having reduced axial, radial, and hoop stresses. It is to such cutters that the present invention is addressed.
SUMMARY
[0012] An abrasive tool insert includes a substrate having an inner face that has a center, an annular face and an abrasive layer. The inner face slopes outwardly and downwardly from the center. The annular face slopes downwardly and outwardly from the inner face. A continuous abrasive layer, having a center and a periphery forming a cutting edge, is integrally formed on the substrate.
[0013] The substrate may include cemented metal carbide. The abrasive layer may include diamond, cubic boron nitride, wurtzite boron nitride, or a combination thereof. The abrasive layer may have a thickness of at least about 0.1 mm. The annular face may terminate in a ledge surrounding the periphery of the annular face.
[0014] Another embodiment of the abrasive tool insert includes a substrate, an annular face and an abrasive layer. The substrate includes an inner face which has a center. The inner face slopes outwardly and downwardly from the center at an angle from about 5° to about 15°. The annular face slopes downwardly and outwardly from the inner face at an angle of from about 20° to about 75°. The abrasive layer includes a cutting edge and is integrally formed on the substrate. The abrasive layer has a thickness of at least about 0.1 mm.
[0015] An interface between the substrate and the abrasive layer may be non-planar. The substrate may include cemented metal carbide. The cemented metal carbide may include a Group IVB, Group VB, or Group VIB metal carbide or a combination thereof. The abrasive layer may include diamond, cubic boron nitride, wurtzite boron nitride, or a combination thereof. The non-planar interface may include a sawtooth pattern of concentric rings.
[0016] Advantages of the present invention include the increase of the useful life of abrasive tool inserts by reducing the thermally induced residual radial and axial stresses in the abrasive layer. Another advantage is the ability to increase the impact performance and extend the working life of the cutting tools. These and other advantages will be readily apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] For a fuller understanding of the nature and advantages of the present invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:
[0018] FIG. 1 is an overhead view of one embodiment of the interface configuration of the present invention;
[0019] FIG. 2 is a cross-sectional elevational view of the substrate of FIG. 1 ; and
[0020] FIG. 3 graphically displays the stress (MPa) versus inner face angle for a cutter element having the profile as depicted in FIG. 2 .
[0021] The drawings will be described in detail below.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The shape of the carbide support in FIGS. 1 and 2 is unique in that it contains 2 distinctive faces of support for the abrasive material, each face being disposed at an angle (relative to the horizontal) so as to optimized (minimize) radial stress and axial stress. To that end, a cutter, 10 , is formed from a lower support, 12 , and an upper abrasive layer, 14 (see FIG. 2 ). Support 12 has a central, inner face, 16 , that extends outwardly and downwardly from an apex or center, 18 . Surrounding face 18 is an outer annular face, 20 , that extends outwardly and downwardly from the outer periphery of face 16 . A slight ledge, 22 , surmounts the outer periphery of annular face 20 . Superimposed on inner face 16 can be sawtooth annuli and troughs, such as are proposed in U.S. Pat. No. 6,315,652.
[0023] In order to optimize (minimize) radial stress, outer annular face 20 should slope downwardly from the horizontal at an angle of between about 20° and about 75° with about 45° being preferred. In order to optimize (minimize) axial stress, inner face 16 should slope downwardly from the horizontal at an angle of between about 5′ and about 15′ with about 7.5° being preferred.
[0024] Such angles were determined by conducting finite element analysis. Additionally, data was extrapolated from the finite element analysis modeling, which data reflected the radial axial stress of 3.0 mm cylindrical carbide supported compacts 1.25 mm in height, wherein the outer annular face had an angle of about 45° with respect to the horizontal, while the inner face angle varied between about 0′ and 30′ from the horizontal. The results of work is set forth in FIG. 3 . It will be observed that both radial and axial stress was minimized at about 7.5° with an optimized (minimized) range of stresses being expected at about 5° to 15° from the horizontal.
[0025] In interrupted cut impact testing on a granite block in a fly cutter configuration using of the inventive dual slope tool inserts compared to a single slope tool insert, an unexpected improvement in impact resistance was demonstrated.
[0026] The polycrystalline upper layer preferably is polycrystalline diamond (PCD). However, other materials that are included within the scope of this invention are synthetic and natural diamond, cubic boron nitride (CBN), wurtzite boron nitride, combinations thereof, and like materials. Polycrystalline diamond, however, is the preferred polycrystalline layer. The cemented metal carbide substrate is conventional in composition and, thus, may be include any of the Group IVB, VB, or VIB metals, which are pressed and sintered in the presence of a binder of cobalt, nickel or iron, or alloys thereof. The preferred metal carbide is tungsten carbide.
[0027] Further, in the practice of this invention, the outer surface configuration of the diamond layer is not critical. The surface configuration of the diamond layer, then, may be hemispherical, planar, conical, reduced or increased radius, chisel, or non-axisymmetric in shape. In general, all forms of tungsten carbide inserts used in the drilling industry may be enhanced by the addition of a diamond layer, and further improved by the current invention by addition of a pattern of ridges, as disclosed herein.
[0028] The disclosed abrasive tool insert is manufactured by conventional high pressure/high temperature (HP/HT) techniques well known in the art. Such techniques are disclosed, inter alia, in the art cited above.
[0029] While the invention has been described with reference to a preferred embodiment, those skilled in the art will understand that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. In this application all units are in the metric system and all amounts and percentages are by weight, unless otherwise expressly indicated. Also, all citations referred herein are expressly incorporated herein by reference. | An abrasive tool insert is formed from a substrate having an inner face that has a center. The inner face slopes outwardly and downwardly from the center. An annular face slopes downwardly and outwardly from the inner face. An abrasive layer, having a center and a periphery forming a cutting edge, is integrally formed on the substrate. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of provisional application Ser. No. 61/101,235, filed Sep. 30, 2008, entitled “Plug Catcher,” the contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to completion and stimulation of oil and gas and more particularly, but without limitation, to filtering return well fluids in a plug drill out operation.
BACKGROUND OF THE INVENTION
There are many situations while completing or performing remedial work on a well where it becomes necessary to isolate particular zones of a well. One reason for isolating a zone is for performing multiple stage downhole stimulations. Industry available products that will isolate the well bore to prevent passage of fluid to other zones are called “plugs.”
Essentially a plug isolates some part of the well from another part of the well. There are several types of plugs, including bridge plugs and frac (fracture) plugs. A bridge plug or frac plug is placed within the wellbore to isolate upper and lower sections of a zone. Bridge plugs hold pressure from both directions, while a frac plug holds pressure from above but allows upward flow. Plugs may be temporary or permanent.
A plug is removed by drilling or milling through it with a bit or blade in combination with circulating a drilling fluid through well to bring up the debris. In a drilling/milling operation, fluid is circulated from the surface through the bit or mill to flush the debris and cuttings from the well. The fluid carries the cuttings and debris to the surface where it is piped to a return tank.
At times it is necessary to work on these wells in an under-balanced condition where the pressures on the well must be controlled by using a choke or choke manifold. A choke is basically a restriction in the return line to hold pressure against the returning flow stream. With the pump rate being constant, the choke or choke manifold will control the downhole pressure. The larger the choke size/opening, the lower the back pressure and the lower the downhole pressure. Conversely, the smaller the choke size/opening, the higher the back pressure and the downhole pressure.
Chokes can be fixed or adjustable. Fixed chokes, also called positive chokes, are basically an orifice and come in a variety of sizes. An adjustable choke is variable and can be controlled electrically, hydraulically, pneumatically, or manually.
Because of their small openings, both fixed (positive) choke and variable chokes are susceptible to debris blocking. Inadvertent restrictions in the flow path can cause undesirable conditions in the well bore associated with drilling and/or milling operations. A restricted flow stream will reduce the ability of the circulated fluid to carry the debris and cuttings to the surface. This condition is serious as it may result in the pipe becoming stuck in the wellbore.
Plugs can be constructed of various materials, including composite materials and metals, such as brass, steel, aluminum, and cast iron. Depending on the material of the plug, the cuttings and debris may include small particulates and/or large rubber or fibrous shreds. Factors determining the size and composition of the debris and cuttings include the differential pressure across the plug when it is milled or drilled, the size of the mill or bit, and the techniques used to break up the plug.
The amount of debris and cuttings produced is dependent on the pipe diameter, pressure rating, plug style and plug manufacture. Common casing size can range from 2⅜ to 9⅝ inches. For example, a 4½ inch plug can produce 300 cubic inches of loose debris. The number of plugs used in a single well is dependent on the number of zones. It is not uncommon to have as many as 15 plugs in a single well.
When a choke or choke manifold is used during a milling or drilling operation, the debris can cause the choke to plug causing instability in the milling or drilling operation. There are two common practices for choke installations in a plug milling operation. One is a single fixed choke bean located in or at the return tank. The other is a choke manifold.
If a single choke bean method is used, when debris clogs the choke, the well has to be shut-in and milling operations stopped until the choke can be cleaned and put back into service. If a choke manifold is used and debris clogs one of the chokes, that choke can be bypassed to the other parallel choke. In this process, one person typically is cleaning the clogged primary choke while another person is trying to adjust the secondary choke back to the desirable backpressure. Not only does this process require extra manpower, but there is also the possibility that both chokes get clogged at the same time and the well has to be shut-in until a choke is cleaned.
As debris collects on a choke, holding a consistent backpressure can be difficult. The choke is opened farther to compensate for the debris restriction; but as the choke is opened, the debris can dislodge, reducing the backpressure, or the debris could clog further increasing backpressure.
In a drilling/milling operation, it is beneficial to remove the milling shavings before the flow stream reaches the choke. Filters or strainers can be placed upstream of the choke to prevent the debris getting to the choke. However, in such systems, parallel filtering systems with a bypass valving arrangement may be required.
The present invention provides the ability to drill continuously multi-plug zones under most common conditions without interrupting the drilling/milling operation to clear a clogged choke. In addition, the invention provides a compact, modular, single filtering system that is easily rigged and can be cleaned while in service. These and other advantages of the invention will be apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a modular filter system constructed in accordance with a preferred embodiment of the present invention.
FIG. 2 is a partially cut-away perspective view of the filter system shown in FIG. 1 .
FIG. 3 is a perspective view of the filter screen preferably used in the system shown in FIGS. 1 and 2 .
FIG. 4 is a table illustrating the process steps of the filter method of the present invention.
FIG. 5 is a flow chart illustrating the method of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings in general and to FIG. 1 in particular, there is shown therein a modular filtering system constructed in accordance with a preferred embodiment of the present invention and designated generally by the reference numeral 10 . The system 10 is adapted for filtering debris and other particulates out of a fluid stream received from a well, such as an oil or gas well (not shown) undergoing a drill out, flow back, well-test or other operation. While only one system 10 is shown in the drawings, multiple systems may be used in parallel.
The system 10 comprises a main filter line 12 , a flow back line 14 , and a bypass line 16 . The filter line 12 comprises a filter section 18 . The filter section 18 is adapted to allow the fluid stream from the well to pass through while separating solids from the fluid. A preferred filter section 18 comprises an outer tube or manifold spool 20 inside of which is mounted an inner filter tube 22 shown in FIGS. 2 and 3 , which will be described in more detail below.
A pressure sensor or gauge 24 is provided on the manifold spool 20 . On the upstream end of the manifold spool 20 is an isolation valve 26 which connects to an inlet T 28 . Extending upstream from the inlet T 28 is a fitting, such as the wellhead connection 30 , which is adapted to connect to the wellhead (not shown). Thus, the valve 26 , the inlet T 28 and connector 30 form an inlet line 32 . A pressure sensor or gauge 34 is fixed to the inlet T 28 in the inlet line 32 to monitor the upstream pressure in the system 10 .
On the downstream end of the spool 20 is a debris transfer line 35 comprising a downstream isolation valve 36 that connects the filter 18 to the inlet end 37 of a debris tube, such as a 3-inch pup joint 38 . The outlet end 39 of the pup joint 38 is equipped with a T-joint 40 in a discharge line 41 to direct debris flow through a valved orifice, such as a choke valve, which may be an adjustable 2-inch orifice choke 42 . The open end 43 ( FIG. 2 ) of the pub joint 38 is provided with a removable cap 44 . A magnet (not shown) may be included in the cap 44 to attract and capture metal fragments in the debris flow. The outlet of the choke 42 is equipped with a connector 46 for connecting the system 10 to the debris pit (not shown). As used herein, “debris pit” denotes any excavation, vessel or collector for containing debris or other solids recovered from the return well fluids.
The filter tube 22 is shown best in FIG. 3 , to which attention now is directed. The filter tube 22 comprises an elongate tubular body or member 50 with a plurality of slots, designated collectively at 52 , forming a perforated side wall. The perforations 52 allow fluid communication between the inside and outside of the tube 22 . The upstream or inlet end 50 A and the downstream or outlet end 50 B of the tubular member 50 are provided with collars 54 and 56 by which the tube 22 is mounted inside the spool 20 , as seen best in FIG. 2 .
The outer diameter (O.D.) of the filter tube 22 is less than the inner diameter (I.D.) of the manifold spool 20 to provide an annulus 58 ( FIG. 2 ) to receive the filtrate, that is, the filtered fluid stream. In this way, during normal operation, the residue or debris in the fluid stream will be retained inside the filter tube 22 while the filtrate passes through the slots 52 in the annulus 58 . For example, in the embodiment shown, the O.D. of the filter tube 22 is 3½ inches while the I.D. of the spool 20 is 5½ inches, providing a 1-inch annulus 58 .
With continuing reference to FIGS. 1 and 2 , the flow back line 14 preferably comprises a first outlet or flow back valve 60 connected to the downstream end of the manifold spool 20 . The flow back valve controls the fluid flow from the filter to the flow back line and. A second outlet or backflow valve 62 in a backflow line 64 may also be included for uses to be described and, when included, is connected to the upstream end of the spool 20 . A connecting pipe 66 makes a fluid connection between the first and valves 60 and 62 . That is, the connecting pipe 66 forms a part of both the backflow line 64 and the bypass line 16 and is a common fluid connection to the flow back line 14 .
An outlet T 70 in the flow back line 14 is connected to the outlet of the first outlet valve 60 . A fitting or connector 72 is provided on the outlet T 70 to connect the T to the flow back tank for directing the filtrate to the flow back tank (not shown). “Flow back tank” is used broadly and refers to any vessel or collector suitable for holding fluids processed by the filter system 10 . A purge valve 74 is connected to the outlet T 70 . A valved orifice, such as a choke valve 76 , is connected between the purge valve 74 and the main filter line 12 between the pup joint 38 and the downstream isolation valve 36 using a connecting joint 78 that forms a purge line.
Referring still to FIGS. 1 and 2 , the bypass line 16 will be described. The bypass line 16 comprises a bypass valve 82 connected between the main filter line 12 and the second outlet valve 62 (or the first outlet valve 60 , if there is no second valve 62 ). The inlet of the bypass valve 82 is connected to the main filter line 12 between in the inlet T 28 and the upstream isolation valve 26 . The outlet of the bypass valve 82 is connected to the second outlet valve 62 (or first outlet valve 60 ) by a connecting joint 84 forming part of the bypass line 16 .
The use and operation of the inventive system is illustrated in the Process Logic Table shown in FIG. 4 and flow chart shown in FIG. 5 , to which attention now is directed. The fluid stream enters the system 10 at the wellhead connection 30 . With the upstream isolation valve 26 and the first outlet valve 60 open and the other valves closed, the fluid stream passes directly through the filter section 18 . The debris collects or stacks up inside in the filter tube 22 and the filtrate passes through the annulus 58 , out the outlet valve 60 in the flow back line 14 , and finally out the outlet T 70 to the flow back tank.
The operator monitors the system 10 to determine when the filter tube 22 is full or near full and needs cleaning. This determination may be made by monitoring the pressure differential between the upstream and downstream pressures as indicated by the gauges 24 and 34 . Alternately, cleaning intervals may be scheduled based on the filter capacity and the expected volume of debris generated by the milled plug. Still further, the cleaning mode may be scheduled at regular intervals to ensure that the filter never becomes overly clogged. The control of the system 10 as described herein is carried out manually by a human operator. However, it will be understood that the operation of the system 10 alternately be controlled by a computer-run control system (not shown).
The cleaning mode begins by equalizing the pressure across the downstream isolation valve 36 and then opening that valve. First, the purge valve 74 is opened and then the purge choke 76 is adjusted. Next, the purge valve 74 and choke 76 are both closed, and the isolation valve 36 is opened. Next, the debris choke 42 is adjusted to allow the debris to move into the pup joint 38 . The debris may then be isolated in the pup joint 38 by closing the isolation valve 36 and the debris choke 42 . It will be appreciated that this cleaning operation can be performed without disrupting the return flow from the well through the filter.
To remove the debris from the pup joint 38 , the purge valve 74 is opened, the choke 76 is adjusted, and the debris is purged from the system 10 . When the purge is completed, the purge choke 76 is closed, the debris choke 42 is closed, and the purge valve 74 is closed. The system 10 now is reset to the normal flow back mode.
In some instances, the filter may be cleared manually. To do so, the upstream isolation valve 26 , the purge valve 74 , and both the outlet valves 60 and 62 are closed, and the bypass valve 82 and the downstream isolation valve 36 are opened. This diverts the flow stream straight through the bypass line 16 and out the flow back line 14 , totally bypassing the filter line 12 . While the fluid stream is thus diverted, but not interrupted, the filter section 18 may be cleaned manually with a suitable tool.
The filter system 10 provides an important advantage during servicing of the system between uses, that is, when the system is disconnected from the well or other source. It will be seen from FIGS. 1 and 2 that, in the preferred embodiment the filter section 18 and the pup joint 38 are both straight and aligned coaxially with each other and with the inlet 30 the capped end 43 . When the cap 44 is removed from the capped end 43 , a straight line of sight is formed from the end to the inlet 30 . This allows visual inspection of the inside of the inner tube 22 of the filter.
It will also now be apparent that during normal operation of the system, the flow stream flows first into the inside of the filter tube 22 and out through the slots 52 of the tube. In some situations, it is advantageous to reverse this flow, that is, to direct the fluid stream first into the annulus 58 , through the slots 52 to the inside of the filter tube 22 . This is accomplished by opening the bypass valve 82 , the downstream isolation valve 36 , and the second outlet valve 62 , and closing the upstream isolation valve 26 , the first outlet valve 60 , the purge valve 74 , and the purge choke 76 . This will direct the fluid first through the bypass line 16 , then through the second outlet valve 62 into the annulus 58 of the filter section 18 . The filtrate would flow through the slots 52 , then through the inside of the filter 22 and out through the open isolation valve 36 . The debris would remain trapped in the annulus 58 until removed.
As used herein, “valve” refers very broadly to any device capable of blocking or diverting fluid flow through a conduit. As used herein, a “choke” refers broadly to any device capable of modulating the flow rate of a fluid through a conduit. Thus, as used herein, a “valve” may or may not function as a “choke,” but a “choke” denotes a valve or other device with a fluid throttling capability and thus includes many types of valves.
The embodiments shown and described above are exemplary. Many details are often found in the art and, therefore, many such details are neither shown nor described. It is not claimed that all of the details, parts, elements, or steps described and shown were invented herein. Even though numerous characteristics and advantages of the present inventions have been described in the drawings and accompanying text, the description is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of the parts within the principles of the inventions to the full extent indicated by the broad meaning of the terms of the claim(s). | A system and method for separating solids from return fluids in well drill-out, flow back, well-test, and other production operations. Solids are collected in a filter comprising a perforate inner tube inside a solid outer tube with an annulus therebetween. The fluid stream from the well enters the filter through the inner tube so that the solids are captured inside and the filtrate flows out through the annulus. The filtrate is passed though a flow back line to a flow back tank. As needed, the solids are removed from the inner tube into a debris tube without interrupting the fluid flow through the filter. Chokes are included for equalizing the pressure along the flow path as the debris is moved from the filter to the debris tube and from the debris tube into to a debris pit so that dramatic changes in pressure are avoided. | 4 |
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